JP2008233280A - Developer, carrier, developer supply device, image forming apparatus, process cartridge - Google Patents

Abstract

In a two-component development type image forming apparatus, the charging property in the developing apparatus is kept stable, the occurrence of carrier adhesion on a solid image portion during long-term use is suppressed, and the occurrence of color stains on a color image is also prevented. Providing fine, high-quality images over a long period of time.
SOLUTION: A hydrophobic fine powder is externally added to base particles composed of at least a colorant and a binder resin, and a specific surface area St of the toner particles after the external addition of the hydrophobic fine powder satisfies the following formula. The carrier has a core material and a coating film, the coating film contains a binder resin and particles, and the ratio of the average particle diameter to the average film thickness is 0.01 to 1. And the surface has irregularities with an average height difference of 0.02 to 2.0 μm. Sm + 0.7Ss * X / 100 <St <Sm + 0.97Ss
* X / 100 (where Sm is the specific surface area of the base particles, Ss is the specific surface area of the hydrophobic fine powder, and X is the addition rate (mass%) of the hydrophobic fine powder to the base particles.)
[Selection] Figure 1

Description

  The present invention relates to an electrophotographic carrier used for a two-component developer used in electrophotography and electrostatic recording method, a replenishment developer using the electrophotographic carrier, a developer in a developing device, a process cartridge, and an image. The present invention relates to a forming apparatus.

  In an electrophotographic image forming apparatus such as a copying machine or a printer, a uniformly charged image carrier surface is exposed to form a latent image, and the latent image is developed into a toner image. Transferring onto a transfer material such as recording paper is performed. The transfer material carrying the toner image passes through the fixing device, and the toner is fixed on the transfer material by the heat or pressure.

In the image forming apparatus, the developing device that develops the latent image on the image carrier includes a one-component developing type that develops using toner containing a magnetic material, and a developer composed of toner and carrier. There are two-component development systems that perform development.
Among these, the two-component developing type developing device is excellent in developability and is used in most image forming apparatuses currently used. In particular, in recent years, color image forming apparatuses that form full-color and multi-color images are often used, and the demand for a two-component developing type developing apparatus is further increasing.
In the image forming apparatus of the two-component development system, the toner and the carrier are agitated in the developing device, and the toner is given a charge from the carrier by its triboelectric charge and is electrostatically attached to the outer surface of the carrier. Become. The carrier carrying the toner is transported to the development area, and under the condition that the development bias is applied, the toner leaves the carrier and electrostatically adheres to the latent image portion of the image carrier to form a toner image. Is done. For this reason, in the two-component development system, in order to provide a highly durable image satisfying high stability, it is important that a stable charge amount is imparted to the toner from the carrier during stirring. For this purpose, it is important that the charge imparting ability of the carrier is stable even before and after long-time use.

  However, in the developing device in the normal two-component developing system, the toner is consumed by the developing operation, while the carrier is not consumed and remains in the developing tank. For this reason, the carrier that is stirred together with the toner in the developing tank deteriorates due to the occurrence of peeling of the resin coating on the carrier surface or adhesion of the toner to the carrier surface as the stirring frequency increases. The resistance value and the chargeability of the developer are gradually lowered, and the developability of the developer is excessively increased, thereby causing a problem that the image density is increased or fog is generated.

As a solution to the above problem, for example, in Patent Document 1, a carrier is added together with toner consumed by development, and the carrier in the developing device is replaced little by little, thereby suppressing a change in charge amount and image density. Has been disclosed, a so-called trickle developing type developing device.
However, even in the developing device disclosed in Patent Document 1, the ratio of deteriorated carriers gradually increases in the developing tank as it is used for a long time, and it is difficult to suppress problems such as an increase in image density. there were.

Further, in Patent Document 2, as a developer to be replenished appropriately in the developing device, a developer including a carrier having a higher resistance value than that of a carrier previously stored in the developing device together with the toner is used. In other words, it is disclosed to maintain chargeability and suppress deterioration of image quality.
Further, in Patent Document 3, as a replenishment developer, a developer containing a carrier that imparts a higher charge amount to the toner together with the toner is used to maintain the chargeability and suppress the deterioration of the image quality. It is disclosed.

However, since the amount of carrier exchanged in the developing device differs at each time point due to the difference in toner consumption, in the method disclosed in Patent Document 2 or 3, the resistance value or charging of the developer in the developing device. There was a problem in that the amount of change changed and the image density was likely to fluctuate.
Further, Patent Document 4 discloses a method of sequentially replenishing each developer by using a plurality of replenishment developer containing a carrier having different physical properties from a carrier previously stored in the developing device together with the toner. Yes.

  However, since the specific gravity of the carrier and the toner is extremely different in practice, as disclosed in Patent Document 4, one of a plurality of carriers having different physical properties is contained together with the toner in one toner supply container. It is very difficult to sequentially replenish the replenished developer in the developing device so as not to mix with each other, and since the amount of toner with respect to the carrier in the developer is large, the carrier is likely to deteriorate, A stable image cannot be obtained for a long time.

Further, as described in Patent Document 4, in order to increase the resistance value of the carrier for replenishment, when the coating amount of the silicon coat layer coated on the carrier core material is simply increased, the resistance value is increased. As a result, the charge amount of the carrier is lowered, and as a result, the image reproducibility of the developed image is lowered and the background portion is stained.
For this reason, in order to obtain more stable development characteristics in the trickle development method, it is important that the carrier can maintain a stable charge imparting ability even during long-term use.

  The granular carrier used in the two-component development system is for preventing toner filming on the carrier surface, forming a uniform carrier surface, preventing surface oxidation, preventing moisture sensitivity deterioration, extending the life of the developer, and the carrier of the photoreceptor. For the purpose of protecting from scratches or abrasion due to rust, controlling the charge polarity or adjusting the charge amount, it is usually coated with an appropriate resin material (see, for example, Patent Document 5), and various coatings are applied to the coating layer. A method of adding an additive (for example, see Patent Documents 6 to 8) is performed.

Further, Patent Document 9 proposes an additive added to the carrier surface, and Patent Document 10 proposes a coating layer containing conductive particles larger than the coating layer thickness. ing.
Patent Document 11 proposes to use a carrier coating material mainly composed of a benzoguanamine-n-butyl alcohol-formaldehyde copolymer, and Patent Document 12 discloses a melamine resin and an acrylic resin. It has been proposed to use a crosslinked product as a carrier coating material.

However, there are still problems with durability or heat resistance, and there are problems of spent toner on the carrier surface, resulting in unstable charge amount, and occurrence of toner fog and the like. Furthermore, it is necessary to improve the environmental resistance.
In addition, in a developer used in a two-component development system, a resistance adjusting agent has been conventionally included in a carrier in order to obtain stable charging characteristics. Currently, carbon black is frequently used as the resistance adjusting agent.
However, when such a carrier is used in an image forming apparatus for forming a color image, the carbon surface migrates into the color image due to film scraping of the carrier surface or desorption of carbon black. There is a concern that color stains may occur.

Various methods have been proposed so far as means for suppressing the occurrence of such a phenomenon.
For example, Patent Document 13 proposes a carrier in which a conductive material (carbon black) is present on the surface of the core material and the conductive material is not present in the coating layer.
Patent Document 14 discloses that the coating layer has a carbon black concentration gradient in the thickness direction, and the coating layer has a lower carbon black concentration toward the surface, and carbon black is present on the surface of the coating layer. A non-existent carrier has been proposed.
Patent Document 15 discloses a two-layer coated carrier in which an inner coating layer containing conductive carbon is provided on the surface of core material particles, and a surface coating layer containing a white conductive material is further provided thereon. Has been proposed.

However, in recent years, in response to requests from consumers, the above-described electrophotographic image forming apparatus has a tendency to increase the speed, and accordingly, the stress received by the developer has increased dramatically. For this reason, even in the proposals of Patent Documents 13 to 15, it is difficult to completely prevent color stains caused by the transfer of carbon black into an image.
Further, Patent Document 16 discloses a configuration in which a thin film coat having a concavo-convex surface is provided. However, in this method, the long life as currently required is reduced in resistance due to abrasion of the coat layer. It is insufficient. Furthermore, if the coating layer is simply thickened by this method, sufficient unevenness cannot be provided on the carrier surface, which is insufficient to prevent spent from the toner.

Also in the case of toner, in an electrophotographic apparatus or an electrostatic recording apparatus, the toner is attached to an electrostatic latent image formed on a photosensitive member, transferred to a transfer material, and then fixed to the transfer material by heat. To form a toner image. Further, full-color image formation is generally performed by using four color toners of black, yellow, magenta, and cyan. Each toner is developed and each toner layer is superimposed on a transfer material. A full color image is obtained by heating the image and fixing it at the same time.
However, for users who are familiar with printing, the images on full-color copiers are still not at a satisfactory level, and there is a need for higher image quality that satisfies photography, high-resolution, and high-resolution. It is known that a toner having a small particle size and a narrow particle size distribution is effective for improving image quality.

Conventionally, an electrical or magnetic latent image has been developed with toner. The toner used for developing the electrostatic image is generally colored particles in which a binder, a charge control agent, and other additives are contained in a binder resin. The toner production methods are roughly classified into a pulverization method and a polymerization method. In the pulverization method, a colorant, a charge control agent, an anti-offset agent, etc. are melt-mixed in a thermoplastic resin and uniformly dispersed, and the resulting toner composition is pulverized and classified to produce a toner. is doing.
According to the pulverization method, it is possible to produce a toner having excellent properties to some extent, but there are limitations on the selection of the toner material. For example, a toner composition obtained by melt mixing must be capable of being pulverized and classified by an economically usable apparatus. From this requirement, the melt-mixed composition must be made sufficiently brittle. For this reason, when the toner composition is actually pulverized into particles, a high-range particle size distribution is likely to be formed, and if an attempt is made to obtain a copy image with good resolution and gradation, for example, A fine powder having a diameter of 5 μm or less and a coarse powder having a diameter of 20 μm or more must be removed by classification, which has a disadvantage that the yield becomes very low. Further, in the pulverization method, it is difficult to uniformly disperse the colorant, the charge control agent, and the like in the thermoplastic resin. Such uneven dispersion of the compounding agent adversely affects the fluidity, developability, durability, image quality, and the like of the toner.

In recent years, in order to overcome these problems in the pulverization method, for example, toner particles are obtained by a suspension polymerization method (see Patent Document 17). However, the toner particles obtained by this suspension polymerization method are spherical, but have the disadvantage of poor cleaning properties. In development and transfer with a low image area ratio, there is little transfer residual toner, and cleaning defects do not become a problem. However, untransferred images were formed due to high image area ratios such as photographic images, as well as poor paper feed. Toner may be generated on the photoconductor as untransferred toner, and if accumulated, the image may be soiled. In addition, the charging roller that contacts and charges the photosensitive member is contaminated, and the original charging ability cannot be exhibited. Further, the low-temperature fixability is not sufficient, and a lot of energy necessary for fixing is required.

  On the other hand, a method of obtaining irregular toner particles by associating resin fine particles obtained by an emulsion polymerization method is disclosed (see Patent Document 18). However, in the toner particles obtained by this emulsion polymerization method, a large amount of surfactant remains not only on the surface but also inside the particles even after the water washing step, impairing the environmental stability of toner charging, and the charge amount distribution. The background of the obtained image becomes poor. Further, the remaining surfactant may contaminate the photoreceptor, the charging roller, the developing roller, and the like, and the original charging ability may not be exhibited.

  Further, in a fixing process by a contact heating method performed using a heating member such as a heat roller, the toner particles are required to be releasable from the heating member (hereinafter sometimes referred to as “offset resistance”). Here, the offset resistance can be improved by the presence of a release agent on the toner particle surface. On the other hand, in Patent Document 19 and Patent Document 20, there is a method in which not only the resin fine particles are contained in the toner particles but also the resin fine particles are unevenly distributed on the surface of the toner particles, thereby improving the offset resistance. Proposed. However, this proposal has a problem that the fixing lower limit temperature is increased and the low-temperature fixing property, that is, the energy-saving fixing property is not sufficient.

  In addition, the following problems occur in the method of obtaining irregularly shaped toner particles by associating resin fine particles obtained by an emulsion polymerization method. That is, when the release agent fine particles are associated with each other in order to improve the offset resistance, the release agent fine particles are taken into the toner particles. As a result, the offset resistance cannot be sufficiently improved. Resin fine particles, release agent fine particles, colorant fine particles, etc. are randomly fused to constitute toner particles, so that there is a variation in composition (content ratio of constituent components) and molecular weight of the constituent resin among the obtained toner particles. appear. As a result, the toner particles have different surface characteristics, and a stable image cannot be formed over a long period of time. Furthermore, in a low-temperature fixing system that requires low-temperature fixing, there is a problem in that fixing inhibition occurs due to resin fine particles unevenly distributed on the toner surface, and a sufficient fixing temperature range cannot be secured.

  On the other hand, a new production method called dissolution suspension method (EA, Emulsion-Aggregation method) has recently been proposed (see Patent Document 21). This method is a method of granulating from a polymer dissolved in an organic solvent, etc., while the suspension polymerization method forms particles from monomers, and has advantages such as expansion of the resin selection range and polarity controllability. I give it. In addition, the toner has an advantage that the toner structure control (core / shell structure control) is possible. However, the shell structure is a resin-only layer intended to reduce the exposure of the pigment and wax to the surface, and the surface state is not particularly devised, nor is such a structure (non- Patent Document 1). Therefore, although it has a shell structure, the surface of the toner is an ordinary resin and is not particularly devised. When aiming at lower temperature fixing, it is not sufficient in terms of heat-resistant storage stability and environmental charge stability, which is a problem. .

In addition, the suspension polymerization method, the emulsion polymerization method, and the dissolution suspension method generally use a styrene / acrylic resin, and the polyester resin has difficulty in particle formation and has a particle size and particle size. Distribution and shape control are difficult. Furthermore, there is a limit to fixability when aiming at lower temperature fixing.
In addition, for the purpose of heat-resistant storage stability and low-temperature fixing, it has been proposed to use a polyester modified with a urea bond (see Patent Document 22). However, in this proposal, the surface is not particularly devised, and it is not sufficient in terms of environmental charging stability which is more severe.

Recently, in the field of electrophotography, high image quality has been studied from various angles, and among them, the recognition that toner diameter reduction and spheroidization are extremely effective is increasing. However, there is a tendency that as the toner diameter is reduced, the transferability and fixability are lowered, resulting in a poor image. On the other hand, it is known that transferability is improved by making the toner spherical (Patent Document 23). Under such circumstances, in the field of color copiers and color printers, higher speed image formation is desired. The “tandem method” is effective for speeding up (see Patent Document 24).
The “tandem method” is a method for obtaining a full-color image on a transfer sheet by sequentially superimposing and transferring the image formed by the image forming unit on a single transfer sheet conveyed to a transfer belt. A tandem color image forming apparatus has a variety of transfer papers that can be used, has high quality of a full color image, and has excellent characteristics that a full color image can be obtained at a high speed. In particular, the characteristic that a full color image can be obtained at a high speed is a characteristic that is not found in other color image forming apparatuses.

  Attempts have also been made to achieve high speed while improving image quality using spherical toner. For example, a spherical toner such as a chemical toner forms a developed toner image on the photoreceptor densely, so that the transfer pressure at the time of transfer is evenly applied to the toner layer. There are few occurrences of transfer abnormalities such as transfer rate and transfer image dropout. However, when used over time, hydrophobic fine powder (hereinafter referred to as an external additive) that is externally added to improve transferability and fluidity of the toner is rapidly embedded in the toner surface compared to the pulverized toner. Therefore, changes in transferability and fluidity increase. In particular, when the image area is small, that is, when images with low toner consumption are output continuously, the external additive in the toner is buried with the passage of time of use, and the fluidity improvement effect cannot be obtained. There are problems such as fluctuation and conspicuous unevenness on the image due to the fluctuation. In addition to the above problems, in order to improve the fluidity by reducing the particle size of the toner in recent years, the addition amount of the fluidity modifier is increasing more than before in order to maintain the fluidity. However, as the amount added increases, the adhesive force between the external additive and the base particles decreases, and the external additive present in the free state increases, so that it can easily move to the contact member, causing photoconductor filming and carrier contamination. It is the current situation.

Japanese Patent Publication No. 2-21591 Japanese Patent Laid-Open No. 3-145678 Japanese Patent Laid-Open No. 11-223960 JP-A-8-234550 JP 58-108548 A Japanese Patent Publication No. 1-19584 Japanese Examined Patent Publication No. 3-628 JP-A-6-202381 JP-A-5-273789 JP-A-9-160304 JP-A-8-6307 Japanese Patent No. 2683624 Japanese Unexamined Patent Publication No. 7-140723 JP-A-8-179570 JP-A-8-286429 JP 2001-188388 A Japanese Patent Laid-Open No. 9-43909 Japanese Patent No. 2537503 JP 2000-292773 A JP 2000-292978 A Japanese Patent No. 3141784 Japanese Patent Laid-Open No. 11-133667 JP 9-258474 A JP-A-5-341617 Takao Ishiyama and two others “Characteristics and Future Prospects of Newly Toner” (The 4th Imaging Society of Japan / Electrostatic Society Joint Symposium (2000.7.29))

  Accordingly, the present invention has been made in view of the above circumstances, and in a two-component development type image forming apparatus, the charging property in the developing apparatus is kept stable, and the carrier adheres to the solid image portion when used for a long period of time. Toner and carrier, developing method, process cartridge, and image forming apparatus capable of providing high-quality images with fine texture over a long period of time by preventing color stains on color images Is an issue.

The present invention comprises the following configurations (1) to (17).
(1) In a developer composed of a toner and a carrier, the toner is obtained by externally adding hydrophobic fine powder to base particles composed of at least a colorant and a binder resin, and after externally adding the hydrophobic fine powder. The specific surface area St of the toner particles satisfies the following formula (1), and the carrier has a core material and a coating film covering the core material, and the coating film is a binder resin. And the ratio of the average particle diameter of the particles to the average film thickness of the coating film is 0.01 or more and 1.00 or less, and the average height difference on the surface is 0.02 μm or more and 2.0 μm or less. An image forming developer characterized by having irregularities.
Sm + 0.7Ss * X / 100 <St <Sm + 0.97Ss * X / 100 (1)
[In the formula, Sm is the specific surface area of the base particles, Ss is the specific surface area of the hydrophobic fine powder, and X is the addition rate (% by mass) of the hydrophobic fine powder to the base particles. ]

(2) The carrier according to (1), wherein the ratio of the particles to the sum of the weight of the binder resin and the particles in the carrier is 10% or more and 80% or less.
(3) The carrier according to (2), wherein the ratio of the particles to the sum of the weight of the binder resin and the particles is 40% or more and 70% or less.
(4) The ratio of the product of the cross-sectional area of the particles and the number of the particles to the product of the surface area of the core and the number of the cores is 0.3 or more and 30 or less. The carrier according to any one of (3).
(5) The carrier according to any one of (1) to (4), wherein the volume resistivity is 1 × 10 ¹⁰ Ω · cm or more and 1 × 10 ¹⁷ Ω · cm or less.
(6) The carrier according to any one of (1) to (5), wherein the particles contain any one of alumina, silica, and titanium.

(7) The carrier according to any one of (1) to (6), wherein an average film thickness of the coating film is 0.05 μm or more and 4.00 μm or less.
(8) The carrier according to (7), wherein an average film thickness of the coating film is 0.05 μm or more and 2.00 μm or less.
(9) The carrier according to any one of claims 1 to 8, wherein a glass transition temperature of the binder resin is 20 ° C or higher and 100 ° C or lower.
(10) The carrier according to any one of (1) to (9), wherein the weight average particle diameter is 20 μm or more and 65 μm or less.
(11) The carrier according to any one of (1) to (10), wherein the binder resin contains a silicone resin.
(12) The carrier according to any one of (1) to (11), wherein the binder resin contains an acrylic resin.
(13) The electrophotographic carrier according to any one of (1) to (9), wherein at least the binder resin is an acrylic resin and a silicone resin.

(14) The carrier according to any one of (1) to (12) above, wherein magnetization in a magnetic field of 1 kOe is 40 Am ² / kg or more and 90 Am ² / kg or less.
(15) An image in which development is performed while supplying toner and carrier to the developing device and discharging excess developer in the developing device with respect to the developing device containing toner and carrier. In the developer used in the forming device, the developing device is toner and / or the toner contained in the developing device satisfies the following formula (1), and a carrier replenished to the developing device and The carrier accommodated in the developing device has a core material and a coating film that covers the core material, and the coating film contains a binder resin and particles, The ratio of the average particle diameter of the particles to the average film thickness of the film is 0.01 or more and 1 or less, and a developer having irregularities with an average height difference of 0.02 μm or more and 2.0 μm or less on the surface is used. A developing device.
Sm + 0.7Ss * X / 100 <St <Sm + 0.97Ss * X / 100 (1)
[In the formula, Sm is the specific surface area of the base particles, Ss is the specific surface area of the silica fine powder, and X is the addition ratio (mass%) of the hydrophobic fine powder to the base particles. ]

(16) An image carrier that carries an electrostatic latent image and a developing device that visualizes the electrostatic latent image on the image carrier are integrally supported and includes a toner and a carrier. In the process cartridge that is removably provided in the image forming apparatus main body that replenishes the developer with the developer and discharges the developer from the developer, the developer uses the developer according to (15). A process cartridge.
(17) An image carrier that carries an electrostatic latent image and a developing device that visualizes the electrostatic latent image on the image carrier are integrally supported and includes a toner and a carrier. In the process cartridge that is removably provided in the main body of the image forming apparatus that replenishes the developing device with the developer and discharges the developer from the developing device, the developing device includes the developing device development described in (15). A process cartridge characterized by using an agent.

  According to the present invention, good transferability and cleanability can be maintained over a long period of time, the occurrence of photoconductor filming is prevented, there is no fluctuation in image unevenness, and external addition is performed by stirring the developer during use. The toner is not buried, the fluidity and the charging property are not changed for a long time, the external additive is not detached from the toner, and the toner is excellent in stability, and the carrier is durable and charged by the spent scraping effect due to surface irregularities. Since the stability is improved, the charging property of the developer in the developing device can be maintained in a stable state, so that the occurrence of abnormal images due to carrier adhesion is suppressed, and there is no occurrence of color stains. A fine, high-quality image can be provided over a long period of time.

(Image forming device)
Embodiments of the present invention will be described below.
FIG. 1 is a diagram showing a schematic configuration of an image forming apparatus according to an embodiment of the present invention.
In the image forming apparatus main body 100, there are four photoconductors 1 (1a, 1b, 1c,
The image forming units 2A, 2B, 2C, and 2D, which are process cartridges having 1d), are detachably attached to the image forming apparatus 100, respectively. A transfer device 3 in which a transfer belt 8 is mounted between a plurality of rollers so as to be rotatable in the direction indicated by an arrow is disposed in the approximate center of the image forming apparatus 100.
The photoreceptor 1 provided in each of the image forming units 2A, 2B, 2C, and 2D is disposed on the lower surface of the transfer belt 15 so as to come into contact therewith. In correspondence with the image forming units 2A, 2B, 2C, and 2D, developing devices 10A, 10B, 10C, and 10D having different toner colors are arranged.

The image forming units 2A, 2B, 2C, and 2D are units having the same configuration, the image forming unit 2A forms an image corresponding to magenta, and the image forming unit 2B forms an image corresponding to cyan. The image forming unit 2C forms an image corresponding to the yellow color, and the image forming unit 2D forms an image corresponding to the black color.
In each of the developing devices 10A, 10B, 10C, and 10D disposed in the image forming units 2A, 2B, 2C, and 2D, a two-component developer including toner and a carrier is used, and a developer replenishing device 200 described later is used. From the above, a developing system capable of supplying toner according to the output of a toner density sensor (not shown) provided in the developer container 14, supplying the carrier, discharging the old developer, and replacing the developer Is adopted.
Developer replenishing devices 200A, 200B, 200C, and 200D are disposed above the image forming units 2A, 2B, 2C, and 2D. The developer supply device 200 has a configuration for supplying new toner and a new carrier different from the toner to be supplied to the photosensitive drum 1 to the development device 10, and the configuration is shown in FIG. Has been.

An exposure device 6 as a writing unit is disposed below the image forming units 2A, 2B, 2C, and 2D.
The exposure device 6 is arranged in four laser diode (LD) light sources prepared for each color, a set of polygon scanners composed of a six-sided polygon mirror and a polygon motor, and an optical path of each light source. It is composed of a lens such as an fθ lens or a long cylindrical lens, or a mirror. Laser light emitted from the laser diode is deflected and scanned by a polygon scanner and irradiated onto the photosensitive member 5.

Between the transfer belt 15 and the developer supply device 200, there is provided a fixing device 9 for fixing the image of the transfer paper onto which the image has been transferred. A paper discharge path 51 is formed on the downstream side of the fixing device 9 in the transfer paper conveyance direction, and the transfer paper conveyed there can be discharged onto a paper discharge tray 53 by a pair of paper discharge rollers 52.
A paper feed cassette 7 that can store transfer paper is disposed below the image forming apparatus 100.

  Next, the operation of the image forming apparatus 100 in image formation will be described. When the image forming operation is started, each photoconductor 1 rotates in the clockwise direction in FIG. Then, the surface of each photoconductor 1 is uniformly charged by the charging roller 301 of the charging unit 3. Then, laser light corresponding to a magenta image by the exposure device 6 is applied to the photoreceptor 1a of the image forming unit 2A, and laser light corresponding to a cyan image is applied to the photoreceptor 1b of the image forming unit 2B. The 2C photoconductor 1c is irradiated with a laser beam corresponding to a yellow image, and the photoconductor 1d of the image forming unit 2D is irradiated with a laser beam corresponding to a black image, and a latent image corresponding to image data of each color. Are formed respectively. Each latent image reaches the position of the developing devices 10A, 10B, 10C, and 10D by the rotation of the photoreceptor 1, and is developed there by toners of magenta, cyan, yellow, and black, and a four-color toner image is obtained. Become.

  On the other hand, the transfer paper is fed from the paper feed cassette 7 by the separation paper feed unit, and the toner image formed on each photoconductor 1 by the registration roller pair 55 provided immediately before the transfer belt 15. It is conveyed at the same timing. The transfer paper is charged to a positive polarity by a paper suction roller 54 disposed near the entrance of the transfer belt 15, and thereby electrostatically attracted to the surface of the transfer belt 15. The transfer paper is conveyed while being adsorbed to the transfer belt 15, and magenta, cyan, yellow, and black toner images are sequentially transferred to form a four-color superimposed full-color toner image. . The transfer paper is heated and pressed by the fixing device 9 to melt and fix the toner image, and then passes through a paper discharge system and is discharged onto a paper discharge tray 53 at the top of the image forming apparatus 1.

(Developer)
Next, the configuration around the developing device will be described. FIG. 2 is a schematic cross-sectional view showing a developing device provided in the image forming apparatus of the present invention and the structure around it. In FIG. 2, a developer replenishing device 200 for replenishing a developer composed of new toner and carrier is provided in the developing device 10 above the developing device 10, and the developing device 10 is disposed below the developing device 10. A developer discharging device 300 is provided for discharging the developer that has become excessive.

  The developing device 10 includes a developer container 14 that stores a two-component developer composed of toner and a carrier, and a developer carrying transporter that is arranged so as to rotate in a state of being close to the photoreceptor 1 as an image carrier. A developing roll 12 as a body, two conveying screws 11a and 11b as developer agitating and conveying members arranged to rotate in the developer container 14, and a state in pressure contact with or close to the surface of the developing roller 12 The main part is comprised by the layer thickness control member 13 arrange | positioned by.

  Among these, the developing roller 12 is a cylindrical sleeve 121 that rotates and includes a magnet roll 120 fixed inside. Further, the developer accommodating portion 14 is divided into two by a partition 14c on the center side and is composed of accommodating spaces 14a and 14b that are communicated by communicating portions on both ends, and the conveying screw 11a that rotates in each of the accommodating spaces 14a and 14b, The developer is circulated and conveyed between the storage spaces 14a and 14b while being agitated by 11b. The layer thickness regulating member 13 has a double structure of a nonmagnetic member and a magnetic member, and is arranged so that the tip thereof faces a predetermined magnetic pole of the magnet roll 120.

The developer supply device 200 includes a developer container 230 that contains a two-component developer for replenishment, and a developer replenisher that feeds and supplies the two-component developer in the developer container 230 to the developer container 14. 220. The developer replenisher 220 is provided between the developer container 230 and the developing device 10 so as to be connected to each other.
The detailed configuration of the developer supply device 200 will be described later with reference to FIG.
The developer discharge device 300 collects the two-component developer that is excessive in the developer container 4 and collects the developer that overflows and overflows from the developer container 14 to the collection container 330. It comprises a discharge pipe 331 as developer discharge means. The discharge pipe 331 is disposed such that the upper opening 331a is positioned at a predetermined height in the developer accommodating portion 14, and discharges the developer over the upper opening 331a at the predetermined height. It has become.

The developer discharge device of the present invention is not limited to the above-described configuration. For example, a developer discharge port is opened at a predetermined location of the developing device 10 and the developer discharge port is replaced with the discharge pipe 331. A conveying member such as a discharge screw serving as a developer discharging means may be installed in the vicinity of the developer and the developer discharged from the developer discharge port may be transferred to the collection container 330.
It is also possible to provide this discharge screw at the end or inside of the discharge pipe 331 of this embodiment.

(Replenishment developer)
The replenishment developer of the present invention is a material containing at least a toner and a carrier. As the toner for the replenishment developer stored in the developer container 230, the toner shown below is used, and the carrier is a magnetic material in which a coating layer having predetermined particles is formed on the core material. The carrier is used.
(Developer in developer)
Further, as the toner of the developer in the developing device, the same toner as the toner stored in the developer container 230 or a different toner can be used, and the carrier is also stored in the developer container 230. It can be used with the same carrier or different carriers.
The detailed configuration of the carrier used in this embodiment will be described in detail later.

Next, the developing operation of the developing device will be described with reference to FIG.
First, the developer in the developing device stored in advance in the developer storage unit 14 is stirred and sufficiently mixed by the conveying screws 11a and 11b and is frictionally charged, and then supplied to the developing roller 12. It adheres to the surface of the sleeve 121 in layers.

The layered developer adhering to the developing roller 12 is regulated to a predetermined thickness by the layer thickness regulating member 13 to be a uniform layer, and then the developing area facing the photoreceptor 1 as the sleeve 121 rotates. It is conveyed to D. In this developing area D, the toner of the two-component developer is electrostatically adsorbed to the latent image formed on the photoreceptor 1 in accordance with the image of the original on the image forming apparatus main body 100 (see FIG. 1). Development is performed, and a toner image is formed on the photoreceptor 1.
The toner image formed on the photoreceptor 1 is transferred onto the recording paper on the image forming apparatus main body 100 side, and is fixed on the recording paper by the fixing unit.

  By repeating this developing operation, the toner contained in the developer in the developing device in the developer accommodating portion 14 is consumed and gradually decreases. When this toner reduction is detected by the above-described toner density sensor. Then, the developer supply device 220 of the developer supply device 200 is driven. As a result, a replenishment developer containing a carrier and toner, which will be described in detail below, housed in the developer housing member 231 of the developer housing 230 is replenished. The new two-component developer replenished in the developer accommodating portion 14 is stirred by the conveying screws 11a and 11b in the developer accommodating portion 14 and sufficiently mixed with the developer in the developing device accommodated before replenishment. Is done.

  In the developer accommodating portion 14, the supply of the developer for replenishment from the developer replenishing device 200 causes the carrier and the toner to be replenished at a predetermined ratio, so that the amount of developer in the developer accommodating portion 14 gradually increases. It becomes. The two-component developer that becomes excessive in the developer accommodating portion 14 overflows beyond the regulated height of the accommodating portion 14 and is accommodated in the collection container 330 through the discharge pipe 331 of the developer discharging device 300.

(Developer supply device)
In the image forming apparatus 100 of this embodiment, a developer storage member 231 whose shape is easily deformed is filled with a replenishment developer, and the replenishment developer is sucked by the screw pump 223 and supplied to the development device 10. A developer supply device 200 is provided.
The configuration of the developer supply device 200 will be described in detail below with reference to FIGS.
FIG. 3 is a schematic configuration diagram of a developer supply device 200 used in the present invention. Inside the developer container 230 provided in the developer supply device 200, a developer storage member 231 as a bag-shaped member capable of volume reduction is provided. A new replenishment developer to be replenished to the developer accommodating portion 14 of the developing device 10 is accommodated in the developer accommodating member 231. The developer accommodating member 231 is reduced in volume as the internal pressure decreases due to the developer being supplied to the developer accommodating portion 14.
The developer replenisher 220 includes a screw pump 223 that is connected to the upper end of a replenishing port 15 a provided at a predetermined location of the developing device 10, a nozzle 240 that is connected to the screw pump 223, and a nozzle 240. And an air supply means 260 connected to and driven according to a detection signal from a toner concentration sensor (not shown) or the like installed in the developer accommodating portion 14 and supplying an appropriate amount of developer to the developer. The developer 230 is supplied from the container 230 to the developer container 14.
Between the screw pump 223 and the nozzle 240, there is a transport tube 221 as a developer transport passage communicating with the screw pump 223. The transport tube 221 is preferably made of a flexible and durable rubber material such as polyurethane, nitrile, or EPDM.
The developer supply device 200 has a container holder 222 for supporting a developer container 230 as a developer container. The container holder 222 is made of a material having high rigidity such as resin. Yes.

The developer container 230 includes a developer storage member 231 as a bag-like member formed of a flexible sheet material, and a base portion 232 as a discharge port forming member that forms a developer discharge port.
There is no restriction | limiting in particular as a material of the developer accommodating member 231, A thing with good dimensional accuracy is used suitably. For example, a resin such as a polyester resin, a polyethylene resin, a polypropylene resin, a polystyrene resin, a polyvinyl chloride resin, a polyacrylic acid, a polycarbonate resin, an ABS resin, or a polyacetal resin is preferable.
Further, the base part 232 is provided with a sealing material 233 formed of sponge, rubber or the like, and the sealing material 233 is provided with a cross-shaped cut. Then, by passing the nozzle 240 of the developer replenisher 220 through this notch, the developer container 230 and the developer replenisher 220 are connected and fixed.

In the present embodiment, the base 232 is provided below the developer container 230. Here, the state where the base part 232 is provided below means that the base part 232 faces downward in the developer container 230 in a state where the developer container 230 is disposed in the developer supply device 200. It shows that it is provided at a position including a vertical component.
The position at which the base 232 is provided in the developer container body is not limited to this, and the developer container in a state where the developer container 230 is disposed in the developer supply device 200. 230 may be provided in the horizontal direction of the main body, or may be provided in an oblique direction.

  The developer container is sequentially replaced with a new one as the toner is consumed. However, the developer container 230 according to this embodiment can be easily attached and detached by having the above-described configuration. In addition, it is possible to prevent toner leakage at the time of replacement or use.

The developer accommodating member 231 is not particularly limited in size, shape, structure, material, etc., and can be appropriately selected according to the purpose.
As the shape of the developer accommodating member 231, for example, the above-described cylindrical shape can be preferably used, and it is preferable that spiral irregularities are formed on the inner peripheral surface thereof. By forming such irregularities, the toner stored in the storage member 231 can be smoothly transferred to the discharge port side by rotating the developer container 230. Furthermore, it is particularly preferable that a part or all of the spiral part has a bellows function.
The developer container 230 of the present invention can be easily attached to and detached from the developer replenishing device 200 of the image forming apparatus 100, is suitable for storage and conveyance, and has excellent handling properties.

4A is an external view showing a schematic configuration of a nozzle 240 provided in the developer replenisher 220, FIG. 4B is an axial sectional view thereof, and FIG. FIG. 4B is a cross-sectional view taken along line AA in FIG. As shown in FIG. 4B, the nozzle 240 has a double tube structure including an inner tube 241 and an outer tube 242 that accommodates the inner tube 241 therein. The inside of the inner tube 241 serves as a developer flow path 241 a as a developer transport path for discharging the developer in the developer container 230. The toner in the developer container 230 is sucked by the suction force of the screw pump 223, and is drawn into the screw pump 223 through the developer channel 241a.

  FIG. 5 is a cross-sectional view showing a schematic configuration of the screw pump 223. The screw pump 223 is called a uniaxial eccentric screw pump and includes a rotor 224 and a stator 225 therein. The rotor 224 has a shape in which a circular cross section is twisted in a spiral shape, is formed of a hard material, and is fitted inside the stator 225. On the other hand, the stator 225 is formed of a rubber-like flexible material, and has a hole whose elliptical cross section is spirally twisted, and the rotor 224 is fitted into this hole. Further, the helical pitch of the stator 225 is formed to be twice as long as the helical pitch of the rotor 224. The rotor 224 is connected to a drive motor 226 for rotating the rotor 224 via a universal joint 227 and a bearing 228.

  In this configuration, the toner and carrier transported from the developer container 230 through the developer flow path 241 a of the nozzle 240 and the transport tube 221 enter the inside from the toner suction port 223 a of the screw pump 223. Then, it enters the space formed between the rotor 224 and the stator 225 and is sucked and conveyed in the right direction in FIG. 3 as the rotor 224 rotates. The toner that has passed through the space between the rotor 224 and the stator 225 falls downward from the toner dropping port 223 b and is supplied into the developing device 10 through the developer supply port 14 of the developing device 10.

The developer replenisher 220 used in this embodiment includes an air supply unit 260 that supplies air into the developer container 230.
As shown in FIG. 3, each air flow path 244a, 244b is connected to air pumps 260a, 260b as separate gas delivery devices via air supply paths 261a, 261b as gas supply paths, respectively.
As shown in FIG. 4B, the air flow path 244 is provided as an air supply passage between the inner tube 241 and the outer tube 242 of the nozzle 240 of the developer replenisher 220. As shown in FIG. 4C, the air flow path 44 is composed of two flow paths 244a and 244b having a semicircular cross section independent from each other.
As the air pumps 260a and 260b, a normal diaphragm type air pump can be used. The air sent out from these air pumps 260a and 260b is supplied into the toner container 230 from air supply ports 246a and 246b as gas supply ports of the respective air channels through the air channels 244a and 244b, respectively. Each air supply port 246a, 246b is located below the toner outlet 247 as a developer outlet of the toner channel 241a in the figure. As a result, the air supplied from the air supply ports 246a and 246b is supplied to the toner in the vicinity of the toner outlet 247, and is left unused for a long period of time and the toner outlet 247 is clogged. Even in such a state, the toner blocking the toner outlet 247 can be destroyed.

  The air supply passages 261a and 261b are provided with on-off valves 262a and 262b as closing means that are opened and closed by a control signal from a control unit as gas delivery control means (not shown). The on-off valves 262a and 262b operate to open the valve when the ON signal is received from the control unit and allow air to pass therethrough, and when the OFF signal is received from the control unit to close the valve and prevent the passage of air.

Next, the operation of the developer supply device 220 in this embodiment will be described with reference to FIG.
The control unit receives the signal indicating that the toner density is insufficient from the developing device 10 and starts the developer supply operation. In this developer replenishment operation, first, the air pumps 260a and 260b are driven to supply air into the developer container 230, and the drive motor 226 of the screw pump 223 is driven to suck and convey the developer. .
When air is sent out from the air pumps 260a and 260b, the air enters the air flow paths 244a and 244b of the nozzle 240 from the air supply paths 261a and 261b, and is supplied into the developer container 230 from the air supply ports 246a and 246b. The By this air, the developer in the developer container 230 is agitated to a state in which a large amount of air is contained, and fluidization is promoted.

Further, when air is supplied into the developer container 230, the internal pressure in the developer container 230 increases. Therefore, a pressure difference is generated between the internal pressure and the external pressure (atmospheric pressure) of the developer container 230, and a force that moves in the direction in which the pressure is applied acts on the fluidized developer. As a result, the developer in the developer container 230 flows out from the direction in which pressure is applied, that is, from the developer outlet 247.
In the present embodiment, the suction force by the screw pump 223 also acts, and the developer in the developer container 230 flows out from the developer outlet 247.

  As described above, the developer that has flowed out of the developer container 230 moves from the developer outlet 247 through the developer channel 241 a of the nozzle 240 into the screw pump 223 via the transport tube 221. Then, after moving in the screw pump 223, it falls downward from the developer dropping port 223 b and the developer is supplied into the developing device 10 from the developer supply port 14. When a certain amount of developer supply is completed, the control unit stops driving the air pumps 260a and 260b and the drive motor 226, closes the on-off valves 262a and 262b, and ends the toner supply operation. Thus, by closing the on-off valves 262a and 262b at the end of the toner supply operation, the toner in the toner container 230 is prevented from flowing back to the air pumps 260a and 260b through the air supply passages 244a and 244b of the nozzle 240. is doing.

The supply amount of air supplied from the air pumps 260 a and 260 b is set to be smaller than the suction amount of toner and air by the screw pump 223. Therefore, as the toner is consumed, the internal pressure of the developer container 230 decreases. Here, since the developer accommodating member 231 of the developer accommodating unit 230 in this embodiment is formed of a flexible sheet material, the volume is reduced as the internal pressure decreases.
FIG. 6 is a perspective view of the developer containing member 231 filled with the developer.
FIG. 7 is a front view showing a state in which the developer inside the developer accommodating member 231 has been discharged and reduced in volume. Here, it is desirable that the developer containing member 231 has a volume reduced by 60% or more.

In the developer container 231 of the developer container 230 shown in FIG. 6, as described above, a replenishment developer composed of a carrier and toner for replenishing the developing device 10 is accommodated.
The supply developer preferably has a carrier weight ratio of 3 wt% or more and less than 30 wt% in the supply developer.
If the weight ratio of the carrier in the developer for replenishment in the developer container 230 is less than 3 wt%, the amount of the replenished carrier is very small, so that the replenishment effect cannot be obtained sufficiently. On the other hand, if it exceeds 30 wt%, stable supply of the replenishment developer to the developer accommodating portion cannot be obtained.

Next, the toner and carrier contained in the replenishment developer and the developer in the developing device will be described.
(Career)
The carrier of the present invention has a core material and a coating film covering the core material, the coating film contains a binder resin and particles, and the average particle diameter D of the particles with respect to the average film thickness h of the coating film The ratio (D / h) is 0.01 or more and 1 or less, preferably 0.1 or more and 1 or less. Thereby, a carrier having good durability and capable of suppressing carrier adhesion is obtained. When D / h is larger than 1, when running with a low image area, a decrease in resistance due to the removal of the convex portion due to the particles of the coating film occurs, and the image quality deteriorates. In addition, when D / h is smaller than 0.01, unevenness due to particles is hardly seen, the surface of the coating film is flattened, charging performance is deteriorated due to adhesion of toner, etc. Decreases.
The thickness h of the coating layer was obtained from the average value by observing the cross section of the carrier using a transmission electron microscope (TEM), measuring the thickness of the resin portion of the coating layer covering the carrier surface. Specifically, the distance from the carrier cross section to the surface of the arbitrary 50 points of the core material and the surface of the coat layer was measured, and the average of the measured values was obtained as the thickness h (μm).

The average particle diameter D of the particles in the coating layer was determined by adding aminosilane (SH602) to the juicer mixer.
0: Toray Dow Corning Silicone Co.) Add 30 ml of toluene solution to 30 ml. Add 6.0 g of the sample, set the mixer rotation speed to low and disperse for 3 minutes. An appropriate amount of the dispersion is added to 500 ml of a toluene solution prepared in advance in a 1000 ml beaker and diluted. The diluting solution is continuously stirred with a homogenizer. The volume average particle size is measured with an ultracentrifugal automatic particle size distribution analyzer CAPA-700 (manufactured by Horiba Seisakusho).

Measurement conditions Rotational speed: 2000rpm
Maximum particle size: 2.0 μm
Minimum particle size: 0.1 μm
Particle size interval: 0.1 μm
Dispersion medium viscosity: 0.59 mPa · s
Dispersion medium density: 0.87 g / cm ³
Particle density: For the density of inorganic fine particles, enter the true specific gravity value measured using a dry automatic bulk density meter Accupic 1330 (manufactured by Shimadzu Corporation).

The average height difference of the irregularities on the surface of the carrier of the present invention is 0.02 to 2.0 μm, preferably 0.05 to 2.0 μm. When the average height difference is larger than 2.0 μm, the toner is easily fixed in the concave portion, and the charging performance is likely to be lowered. In addition, the particles forming the convex part may be peeled off and the resistance may be lowered. On the other hand, if the average height difference is smaller than 0.02 μm, the toner scraping effect is reduced, so that the toner is fixed and the charging performance tends to be lowered.
The average height difference was determined by observing the cross section of the carrier using a transmission electron microscope (TEM) and measuring the thickness of the resin portion of the coating layer covering the carrier surface. Specifically, the distance from the carrier cross section to an arbitrary 50 points of the core surface and the coat layer surface is measured, and the average value of 5 points from the large value of the measured value and the 5 points from the small value of the numerical value. The difference from the average was taken.

  When the carrier of the present invention is observed with an SEM, irregularities can be confirmed on the surface, and it can be seen that particles are contained in the coating film. In this case, compared with the case where D / h is larger than 1, the number of convex portions due to particles is reduced, and the average height difference of the unevenness is reduced, but the average film thickness of the coating film is large, so Even during running in the image area, the convex portion is hard to be scraped off, and a decrease in resistance can be suppressed.

(Core material)
In the carrier of the present invention, the core material is not particularly limited as long as it is a known material. And can be appropriately selected and used according to the use and purpose of use of the carrier. Examples include, but are not limited to, MFL-35S (manufactured by Powder Tech Co., Ltd.), MFL-35HS (manufactured by Powder Tech Co., Ltd.), DFC-400M (manufactured by Dowa Iron Powder Industry Co., Ltd.), and the like. Moreover, it is preferable that the average particle diameter of a core material is 20-65 micrometers. When the average particle diameter is less than 20 μm, carrier adhesion to the electrostatic latent image carrier tends to occur. On the other hand, when the average particle diameter exceeds 65 μm, carrier streaks or the like are generated, and the image quality is likely to deteriorate.

In the carrier of the present invention, the ratio of the weight of the particles to the sum of the weight of the binder resin and the particles is preferably 10 to 80% by weight, more preferably 40 to 70%. When the content is less than 10% by weight, since the ratio of particles on the surface of the carrier is small, the effect of relaxing contact with a strong impact on the binder resin is reduced. On the other hand, when the content is more than 80% by weight, the charging performance is deteriorated because the ratio of the binder resin on the surface of the carrier is small. In addition, the ability to hold particles by the binder resin may be insufficient.
Particle content (% by weight) = [particles / (particles + total amount of coating resin solids)]

  In the carrier of the present invention, the ratio of the product of the cross-sectional area of the particles and the number of the particles to the product of the surface area of the core and the number of the cores (hereinafter referred to as particle coverage) is 0.3 or more and 30 or less. Is preferred. Thereby, particle | grains can accumulate moderately inside a coating film and the intensity | strength of a coating film can be raised. As a result, even during long-term running, coating film peeling and wear are reduced, and stable quality can be maintained. When the particle coverage is less than 0.3, the proportion of the particles decreases, and the effect of suppressing toner fixation decreases due to unevenness of the particles. On the other hand, when the particle coverage exceeds 30, the proportion of the binder resin decreases, and the charging performance decreases. Furthermore, the ability to retain particles by the binder resin may be insufficient.

The particle coverage is expressed by the following formula: Particle coverage = (Ds × ρs × W) / (4 × Df × ρf)
It is requested from.
Here, Ds is the average particle diameter of the core material, ρs is the true specific gravity of the core material, W is the ratio of the weight of the particles to the weight of the core material, Df is the average particle diameter of the particles, and ρf is the particle diameter True specific gravity. That is, the surface area of the core material is the surface area of a sphere having a diameter of Ds, the number of core materials is the ratio of the weight of the core material to the weight of the sphere having a diameter of Ds and the true specific gravity is ρs, and the cross-sectional area of the particles is The area of the circle of Df and the number of particles are the ratio of the weight of the core to the weight of a sphere having a diameter of Df and a true specific gravity of ρf. The average particle diameter of the core material is measured in the same manner as the particle diameter D shown above.

The volume resistivity of the carrier of the present invention is preferably 1 × 10 ¹⁰ Ω · cm or more and 1 × 10 ¹⁷ Ω · cm or less. When the volume resistivity is less than 1 × 10 ¹⁰ Ω · cm, carrier adhesion easily occurs in the non-image area. On the other hand, when the volume resistivity exceeds 1 × 10 ¹⁷ Ω · cm, the edge effect decreases. In addition, when it falls below the measurable lower limit of the high resist meter, the volume specific resistance value is not substantially obtained, and it will be treated as a breakdown.

As shown in FIG. 8, the volume specific resistance is obtained by filling a carrier 33 into a cell 31 made of a fluororesin container containing an electrode 32a and an electrode 32b having a distance of 2 mm between electrodes and a surface area of 2 × 4 cm, and manufactured by Sankyo Piotech : Using a tapping machine PTM-1 type, a tapping operation is performed for 1 minute at a tapping speed of 30 times / min. A 1000V DC voltage is applied between the two electrodes, and a high resistance meter 4329A (4329A + LJK5HVLVWDQFH 0H
DC resistance is measured by WHU (manufactured by Yokogawa Hewlett-Packard Co., Ltd.), electric resistivity RΩ · cm is obtained, and LogR is calculated.

In the present invention, the particles are not particularly limited, and examples thereof include inorganic particles such as zinc and barium. Among these, it is preferable to contain any of alumina, silica, and titanium.
In the carrier of the present invention, the average film thickness of the coating film is preferably 0.05 to 4.00 μm or less, more preferably 0.05 to 2.00 μm. When the average film thickness is less than 0.05 μm, the average film thickness of the coating film covering the convex portions due to the particles is not sufficient, so that the convex portions are shaved or the core material is exposed. As a result, the resistance tends to decrease. On the other hand, when the average film thickness exceeds 4.00 μm, as the carrier becomes larger, the charging performance is lowered and the image definition tends to be lowered.

  In the carrier of the present invention, the glass transition temperature of the binder resin is preferably 20 to 100 ° C. As a result, the binder resin has moderate elasticity and can absorb the impact when the toner and the carrier or the carriers come into contact with each other in the stirring for tribocharging the developer. As a result, wear of the coating film can be suppressed. When the glass transition temperature is below 20 ° C., blocking tends to occur. On the other hand, when the glass transition temperature is higher than 100 ° C., the binder resin has a reduced ability to absorb an impact and is easily worn.

The glass transition temperature (Tg) is specifically determined by the following procedure. Shimadzu TA-60WS and DSC-60 were used as measurement devices, and the measurement was performed under the following measurement conditions.
Measurement conditions Sample container: Aluminum sample pan (with lid)
Sample amount: 5mg
Reference: Aluminum sample pan (alumina 10mg)
Atmosphere: Nitrogen (flow rate 50ml / min)
Temperature conditions Starting temperature: 20 ° C
Temperature increase rate: 10 ° C / min
End temperature: 150 ° C
Holding time: None Temperature drop: 10 ° C / min
End temperature: 20 ° C
Holding time: None Temperature increase rate: 10 ° C / min
End temperature: 150 ° C

  The measurement results were analyzed using the data analysis software (TA-60, version 1.52) manufactured by Shimadzu Corporation. The analysis method is to specify a range of ± 5 ° C centering on the point showing the maximum peak on the lowest temperature side of the DrDSC curve, which is the DSC differential curve of the second temperature rise, and use the peak analysis function of the analysis software to determine the peak temperature. Ask. Next, the maximum endothermic temperature of the DSC curve is determined using the peak analysis function of the analysis software in the range of the peak temperature + 5 ° C. and −5 ° C. in the DSC curve. The temperature shown here corresponds to the Tg of the toner.

The weight average particle size of the carrier of the present invention is preferably 20 to 65 μm. When the weight average particle diameter is less than 20 μm, the uniformity of the particles is lowered and carrier adhesion tends to occur. On the other hand, when the weight average particle diameter exceeds 65 μm, the reproducibility of the image details is lowered and it is difficult to obtain a fine image. The weight average particle diameter of the carrier can be measured using an SRA type of a Microtrac particle size analyzer (manufactured by Nikkiso Co., Ltd.). What was performed by the range setting of 0.7 micrometer or more and 125 micrometers or less was used. Further, methanol is used for the dispersion, and the refractive index is set to 1.33, and the refractive indexes of the carrier and the core material are set to 2.42.

In the carrier of the present invention, the binder resin preferably contains a silicone resin.
Since the silicone resin has a low surface energy, it can suppress toner sticking.
As the silicone resin, known ones can be used, and examples include straight silicone resins consisting only of organosilosan bonds, and silicone resins modified with alkyd resins, polyester resins, epoxy resins, acrylic resins, urethane resins, and the like. . Examples of the commercially available straight silicone resin include KR271, KR255, KR152 (manufactured by Shin-Etsu Chemical Co., Ltd.), SR2400, SR2406, SR2410 (manufactured by Toray Dow Corning Silicone). In this case, it is possible to use the silicone resin alone, but other components that undergo a crosslinking reaction, components that adjust the charge amount, and the like can also be used simultaneously. Further, as modified silicone resins, KR206 (alkyd modified), KR5208 (acryl modified), ES1001N (epoxy modified), KR305 (urethane modified) (manufactured by Shin-Etsu Chemical Co., Ltd.), SR2115 (epoxy modified), SR2110 (alkyd) Modification) (above, manufactured by Toray Dow Corning Silicone).

In the carrier of the present invention, the binder resin preferably contains an acrylic resin. Since the acrylic resin has strong adhesiveness and low brittleness, it is difficult for the coating film to be worn or peeled off, and the coating film can be stably maintained. Furthermore, the particles contained in the coating layer can be held firmly. In particular, it is effective when holding particles having a particle diameter larger than the average film thickness of the coating film.
A publicly known thing can be used as an acrylic resin, and it is not specifically limited. The acrylic resin can be used alone, but a component that undergoes a crosslinking reaction can also be used at the same time. Examples of the component that undergoes a crosslinking reaction include amino resins such as guanamine and melamine resins, and acidic catalysts. The acidic catalyst is not particularly limited as long as it has a catalytic action, but those having a reactive functional group such as a fully alkylated type, a methylol group type, an imino group type, and a methylol / imino group type can be used. .

  In the present invention, the binder resin preferably contains an acrylic resin and a silicone resin. Since acrylic resin has a high surface energy, when a toner that is easily fixed is used, problems such as a decrease in charge amount due to accumulation of the fixed toner may occur. In this case, this problem can be solved by using a silicone resin having a low surface energy in combination. However, since the silicone resin has weak adhesiveness and high brittleness, it is important to obtain the properties of these two resins in a well-balanced manner. As a result, it is possible to obtain a coating film that hardly adheres to the toner and has excellent wear resistance.

In the carrier of the present invention, the ratio of the weight of the binder resin to the sum of the weight of the binder resin and the core material is preferably 0.1% by weight or more and 1.5% by weight or less. When this ratio is less than 0.1% by weight, the effect of the coating film is not sufficiently exhibited. On the other hand, when it exceeds 1.5% by weight, the amount of wear of the coating film increases.
The carrier of the present invention preferably has a magnetization at 1 kOe of 40 Am ² / kg or more and 90 Am ² / kg or less. Thereby, the holding force between the carrier particles is appropriately maintained, so that the toner is easily dispersed in the carrier or the developer. Magnetization at 1 kOe is 40 Am ²
When it is less than / kg, carrier adhesion tends to occur. On the other hand, when the magnetization at 1 kOe exceeds 90 Am ² / kg, the rise of the developer (magnetic brush) formed at the time of development becomes hard, the reproducibility of image details is lowered, and a fine image is difficult to obtain. The magnetic moment can be measured as follows. Using a BH tracer (BHU-60 / manufactured by Riken Denshi Co., Ltd.), 1.0 g of carrier core particles are packed in a cylindrical cell (inner diameter 7 mm, height 10 mm) and set in an apparatus. The magnetic field is gradually increased and changed to 3000 Oersted, then gradually reduced to zero, and then the opposite magnetic field is gradually increased to 3000 Oersted. Further, after gradually reducing the magnetic field to zero, a magnetic field is applied in the same direction as the first. In this way, the BH curve is illustrated, and the magnetic moment of 1000 oersted is calculated from the figure.

  In the developing device 10, most of the deteriorated carrier is discharged by the developer discharging device 330. However, a part of the deteriorated carrier remains in the developer accommodating portion 14 for a long period of time, and when the toner consumption is small in the image forming apparatus 100, the carrier in the developer accommodating portion 14 is used. There is a case where the amount of exchange of the carrier is small and the period during which the carrier stays in the developer accommodating portion 14 becomes long.

In the present embodiment, the carrier described in detail above is stored in the developer container 230. In the image forming apparatus 100, the replenishment developer including the carrier is replenished from the developer container 230 into the developer container 14.
The toner and the carrier replenished in the developer accommodating portion 14 are mixed together with the toner and the carrier accommodated from the beginning by the conveying screws 11a and 11b. At this time, the toner and the carrier, or the carriers are in contact with each other. However, film abrasion tends to occur on the carrier surface due to the friction.

The carrier contained in the replenishment developer has unevenness caused by particles dispersed in the coating layer on the surface of the coating layer with an average height difference of 0.02 to 2.0 μm. For this reason, even if toner or other carrier particles come into contact with the coating layer during stirring and mixing, the impact is alleviated by the convex portions. For this reason, the rate at which film scraping on the carrier surface occurs can be greatly suppressed. Further, since the spent component of the toner adhering to the carrier surface at the time of stirring is scraped off by this convex portion, the toner in the developer accommodating portion 14 is more stably charged in order to prevent the generation of toner spent. A control effect can be obtained.
In the developing device 10, most of the deteriorated carrier is discharged by the developer discharging device. However, a part of the deteriorated carrier remains in the developer accommodating portion 14 for a long period of time, and when the toner consumption is small in the image forming apparatus 100, the carrier in the developer accommodating portion 14 is used. There is a case where the amount of exchange of the carrier is small and the period during which the carrier stays in the developer accommodating portion 14 becomes long.

In the present embodiment, the carrier used for the replenishment developer is also applied to the developer in the developing device accommodated in the developer accommodating portion 14 before the replenishment developer in the developer container 230 is replenished. The same carrier is used.
For this reason, even when the developer replacement amount is low, or when a part of the carrier accommodated from the beginning remains without being discharged from the developer accommodating portion 14, the same mechanism as described above is used for developing. The deterioration of the carrier in the agent container 14 is suppressed, and the developer can be kept in a stable state even after long-term use.

(toner)
The toner of the present invention is obtained by externally adding hydrophobic fine powder to base particles composed of at least a colorant and a binder resin.

  The toner is obtained by externally adding hydrophobic fine powder to base particles composed of at least a colorant and a binder resin, and the specific surface area St of the toner particles after external addition of the hydrophobic fine powder is expressed by the above formula (1). The image forming toner is characterized by satisfying the above.

That is, the present inventors presume that the adhesion state of the hydrophobic fine powder existing on the toner particle surface determines the ease of transfer to the contact member. It is presumed that the additive moves to any member that comes into contact with the toner such as a carrier and a photoreceptor, and causes filming and charge reduction.

  For the transfer of the external additive to the contact member as described above, the adhesion state of the hydrophobic fine powder existing on the toner particle surface is important, and the adhesion state of the external additive that is difficult to transfer to the contact member is created. is important.

  By allowing the hydrophobic fine powder to be present so as to satisfy the above formula (1), the hydrophobic fine powder does not migrate to the carrier or photoreceptor without repeated transfer to the carrier or the photoreceptor. I found out that it exists. As a result, good transferability and cleanability can be maintained over a long period of time, photoconductor filming can be prevented, image unevenness does not fluctuate, and external additives can be buried by stirring the developer during use. It has been found that a high-quality electrophotographic image can be formed with little change in fluidity and chargeability over a long period of time.

In addition, as a method of mixing the hydrophobic fine powder with the base particles, for example, a known mixer such as a V-type blender, a Henschel mixer, or a hybridizer is used. In this mixing, the hydrophobic fine powder is as follows. It is presumed that it adheres to the base particle by a simple mechanism.
In the mixing device, the agglomerates of hydrophobic fine powders are composed of three processes: a process in which they are first crushed, a process in which they disperse and adhere to the surface of the base particles, and a process in which they begin to adhere to the base surface. it is conceivable that.

  That is, the present inventors can produce a desired state of the attachment of the hydrophobic fine powder on the surface of the base particle by controlling the mixing apparatus and the mixing conditions for attaching the hydrophobic fine powder to the base particle surface. I found.

  If the adhesion state of the hydrophobic fine powder on the surface of the base particle composed of the colorant and the binder resin satisfies the formula (1), the hydrophobic fine powder is uniformly dispersed on the surface of the base particle, Less embedding and less hydrophobic fine powder released from the mother particles, and the hydrophobic fine powder is properly attached to the mother particles. Good images can be obtained over a long period of time.

However, when the external additive adhesion state is St <Sm + 0.7Ss * X / 100, the hydrophobic fine powder is too fixed to the base particle, and is easily buried due to stress inside the developing device, and the fluidity is low. The decrease is large, the toner transportability is deteriorated, and the charge amount of the toner is remarkably decreased, which causes a background stain. Also, the external additive adhesion state is Sm + 0.97Ss * X / 100 <S
When t, the adhesion between the base particles and the hydrophobic fine powder is low, and since there are many free hydrophobic fine powders, it is easy to move to the contact member, and the charge amount is reduced due to photoconductor filming and carrier contamination. It will cause.

Here, St, Sm, and Ss in the above formula are respectively the toner particle specific surface area, the base particle specific surface area, and the specific surface area of the hydrophobic fine powder by BET specific surface area measurement, and X is the addition of the hydrophobic fine powder to the base particle. Rate (% by weight).

  The specific measurement conditions for St, Sm, and Ss are the BET multipoint method (determining the relationship between relative pressure and the amount of adsorbed nitrogen) using TriStar 3000 (manufactured by Shimadzu Corporation), and determining the surface area in 1 g based on the BET theory. Method). These measurements require a step of removing impurities by performing vacuum deaeration as a pretreatment for 24 hours in order to remove impurities on the sample surface, particularly moisture.

The addition rate X of the hydrophobic fine powder is calculated by a fluorescent X-ray analyzer as shown below. Hydrophobic fine powder is previously added to the base particles at a predetermined addition rate (0.1%, 0.3%, 0.6%, 1.2%, 2.4%, 4.8%), and 3 g each. Is molded into a circular pellet having a diameter of 40 mm at a pressure of 6 ton / cm ² for 1 minute to prepare a known sample. This sample is analyzed with a fluorescent X-ray analyzer (wavelength dispersion type fluorescence analyzer RIX3000 manufactured by Rigaku Corporation), and a calibration curve between the X-ray intensity and the addition rate of elements contained in the hydrophobic fine powder is prepared. As for the addition amount of the hydrophobic fine powder of the unknown sample, a pellet is prepared in the same manner as described above, and the addition amount can be calculated by a fluorescent X-ray analyzer.

  Next, mixing of the base particles and the hydrophobic fine powder will be described. When mixing two or more types of external additives having different particle sizes in the hydrophobic fine powder, if they are added at the same time, the small-diameter external additive adheres first, and as a result, the large-diameter external additive adheres. The possible area is reduced, and as a result, the large-diameter external additive is present in a free state. When the small-diameter external additive is added first, high-fluidity expression due to the small-diameter external additive makes it difficult for rubbing between the toners, and the large-diameter external additive added later hardly adheres to the base particles. It tends to exist as a free external additive.

When two or more kinds of hydrophobic fine powders are externally added, a preferable external additive adhesion state can be achieved by first mixing the base particles and the large-diameter external additive and then mixing the small-diameter external additive.
Examples of a mixing apparatus that can mix the hydrophobic fine powder with the base particles and satisfy the formula (1) include known mixers such as a V-type blender, a Henschel mixer, and a hybridization system. The peripheral speed of the rotating body of these devices is preferably 10 to 150 m / s. When the peripheral speed is less than 10 m / s, adhesion between the external additive and the base particles is weak, and a large amount of free external additive is present, so that a desired external additive adhesion state cannot be achieved. On the other hand, if it exceeds 150 m / s, the external additive may be excessively fixed to the base particles and the function as the external additive may be lost.

The external additive and the toner particles are dispersed in an aqueous medium and the external additive is attached to the toner particles, that is, the external additive treatment is performed, so that the formula (1) can be satisfied. .
In the case of dry toner, the wet external addition treatment is performed by dispersing toner base particles before dry external addition in water using a surfactant or the like if necessary. When the toner particles are formed in water, it is preferable to perform a wet external addition step after removing the used surfactant and the like by washing. Excess surfactant present in water is removed by solid-liquid separation such as filtration and centrifugation, and the resulting cake and slurry are redispersed in an aqueous medium. Further, inorganic fine particles are added and dispersed in the slurry. It is also possible to previously disperse the inorganic fine particles in the aqueous dispersion. At that time, if the dispersion is made by using a surfactant having a polarity opposite to that of the surfactant prepared in the aqueous dispersion of the toner base, the toner particles are more efficiently adhered to the surface. In addition, when the inorganic fine particles are hydrophobized and are difficult to disperse in the aqueous dispersion, the inorganic fine particles may be dispersed after the interfacial tension is lowered by using a small amount of alcohol or the like to facilitate wetting.

Thereafter, an aqueous surfactant solution having a reverse polarity is gradually added with stirring. The reverse polarity surfactant is preferably used in an amount of 0.01 to 1% by weight based on the solid content of the toner particles. By adding a surfactant having a reverse polarity, the charge of the inorganic fine particle dispersion in water can be neutralized, and the inorganic fine particles can be aggregated and adhered to the toner particle surfaces. The inorganic fine particles are preferably used in an amount of 0.01 to 5% by mass based on the solid content of the toner particles.
In addition, instead of gradually adding an aqueous surfactant solution having a reverse polarity with stirring, the inorganic fine particles can be adhered by changing the pH of the dispersion to the acid or alkali side.

The inorganic fine particles adhered to the toner surface can be fixed to the toner surface by heating the slurry thereafter to prevent detachment. At that time, it is desirable to heat at a temperature higher than the glass transition temperature (Tg) of the resin constituting the toner. Further, heat treatment after drying may be performed while preventing aggregation.
Further, for the purpose of further enhancing the chargeability, the charge control agent fine particle dispersion may be present in the redispersed slurry. The charge control agent is usually in the form of a powder. However, the surfactant used when the toner particles are produced in the aqueous medium, or the reverse polarity surfactant added for the purpose of imparting the charge, is separately added to the aqueous medium. A fine particle dispersion can be obtained by dispersing in. By adding a surfactant having a reverse polarity, the charge of the charge control agent fine particle dispersion in water can be neutralized and agglomerated and adhered to the surface of the toner particles.

The charge control agent is preferably a dispersion having a particle diameter of 0.01 to 1 μm, and can be used in an amount of 0.01 to 5% by mass based on the solid content of the toner particles.
Further, for the purpose of further enhancing the chargeability, the resin fine particle dispersion may be present in the redispersed slurry. The resin fine particle dispersion is preferably obtained by emulsion polymerization. By adding a surfactant having a reverse polarity, the charge of the resin fine particle dispersion in water can be neutralized and agglomerated and adhered to the toner particle surface. The resin fine particles can be used in an amount of 0.01 to 5% by mass based on the solid content of the toner particles.

As the hydrophobic fine powder, fine particles conventionally used for the purpose of imparting fluidity or chargeability can be used, and examples thereof include oxide fine particles, inorganic fine particles, and hydrophobized inorganic fine particles.
There is no restriction | limiting in particular as said hydrophobic fine powder, According to the objective, it can select suitably according to the objective, For example, silica fine particle, hydrophobic silica, fatty acid metal salt (zinc stearate, aluminum stearate, etc.) ), Metal oxides (titania, alumina, tin oxide, antimony oxide, etc.), fluoropolymers, and the like.

Examples of the silica fine particles include HDK H2000, HDK H2000 / 4, HDK H2050EP, HVK21, and HDK H1303 (all manufactured by Hoechst); R972, R974, RX200, RY200, R202, R805, R812 (all Nippon Aerosil Co., Ltd.) Company-made).
Examples of the titania fine particles include P-25 (manufactured by Nippon Aerosil Co., Ltd.); STT-30, STT-65C-S (both manufactured by Titanium Industry Co., Ltd.); TAF-140 (manufactured by Fuji Titanium Industry Co., Ltd.); There are MT-150W, MT-500B, MT-600B, MT-150A (all manufactured by Teika Co., Ltd.) and the like.
Examples of the hydrophobized titanium oxide fine particles include T-805 (manufactured by Nippon Aerosil Co., Ltd.); STT-30A, STT-65S-S (both manufactured by Titanium Industry Co., Ltd.); TAF-500T, TAF- 1500T (all manufactured by Fuji Titanium Industry Co., Ltd.); MT-100S, MT-100T (all manufactured by Teika Co., Ltd.); IT-S (manufactured by Ishihara Sangyo Co., Ltd.).

In order to obtain the hydrophobized oxide fine particles, silica fine particles, titania fine particles, and alumina fine particles, hydrophilic fine particles are converted into silane coupling agents such as methyltrimethoxysilane, methyltriethoxysilane, and octyltrimethoxysilane. Can be obtained by processing. In addition, silicone oil-treated oxide fine particles and inorganic fine particles obtained by treating silicon oil with heat if necessary to treat it with inorganic fine particles are also suitable.
Examples of the silicone oil include dimethyl silicone oil, methylphenyl silicone oil, chlorophenyl silicone oil, methyl hydrogen silicone oil, alkyl-modified silicone oil, fluorine-modified silicone oil, polyether-modified silicone oil, alcohol-modified silicone oil, amino acid. Modified silicone oil, epoxy modified silicone oil, epoxy / polyether modified silicone oil, phenol modified silicone oil, carboxyl modified silicone oil, mercapto modified silicone oil, acrylic, methacryl modified silicone oil, α-methylstyrene modified silicone oil, etc. can be used. .

Examples of the inorganic fine particles include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, iron oxide, copper oxide, zinc oxide, tin oxide, silica sand, clay, mica, Examples include wollastonite, diatomaceous earth, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, parium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. Among these, silica and titanium dioxide are particularly preferable.
Other polymer fine particles include, for example, polystyrene obtained by soap-free emulsion polymerization, suspension polymerization, dispersion polymerization, polycondensation system such as methacrylate ester, acrylate ester copolymer, silicone, benzoguanamine, nylon, heat Examples thereof include polymer particles made of a curable resin.

Such a fluidizing agent can be surface-treated to increase hydrophobicity and prevent deterioration of flow characteristics and charging characteristics even under high humidity. For example, silane coupling agents, silylating agents, silane coupling agents having an alkyl fluoride group, organic titanate coupling agents, aluminum coupling agents, silicone oils, modified silicone oils and the like are preferable surface treatment agents. .
These hydrophobizing agents are preferably coated by adding 1 to 40 parts by weight to the external additive, and more preferably 3 to 25 parts by weight.
It is preferable that these hydrophobicly treated external additives have a hydrophobization degree indicated by wettability (wetability) to methanol in the range of 30 to 80%.

The degree of hydrophobicity can be calculated by a powder wettability tester WET-100P (manufactured by Reska Co., Ltd.). In the measurement, 50 ml of pure water is put in a 300 ml beaker, and 0.05 g of an external additive is floated on this. While stirring this with a stir bar, methanol was added dropwise at 1 ml / min, and the methanol concentration at the time when the permeability reached 50% was calculated as the degree of hydrophobicity.
These hydrophobic external additives preferably have a primary particle size of 5 to 500 nm, more preferably 10 to 300 nm.

  Examples of the cleaning property improver for removing the developer after transfer remaining on the photoreceptor or the primary transfer medium include, for example, zinc stearate, calcium stearate, fatty acid metal salts such as stearic acid, such as polymethyl methacrylate fine particles, polystyrene fine particles, etc. And polymer fine particles produced by soap-free emulsion polymerization. The polymer fine particles preferably have a relatively narrow particle size distribution and a volume average particle size of 0.01 to 1 μm.

  The content of the external additive in the toner is preferably 0.1 to 8.0%. Among these, when two or more types of external additives having different sizes are used, the small-diameter external additive is 5 to 50 nm, and the toner content is 0.1 to 5.0%. Is 80 nm to 300 nm, and the content is preferably 0.1% to 5.0%.

  The toner of the present invention is not particularly limited as long as the production method and material satisfy the above conditions, and can be appropriately selected from known ones according to the purpose. For example, a high-quality and high-definition image is output. Therefore, it is preferable that the toner has a small particle diameter and a nearly spherical shape. As a method for producing such a toner, there are a pulverization classification method, a suspension polymerization method, an emulsion polymerization method, a polymer suspension method, etc. in which an oil phase is emulsified, suspended or aggregated in an aqueous medium to form toner base particles. is there.

The pulverization method is, for example, a method of obtaining the toner base particles by melting and kneading the toner material, pulverizing, classifying and the like. In the case of the pulverization method, for the purpose of setting the average circularity of the toner in the range of 0.97 to 1.0, the shape is controlled by applying a mechanical impact force to the obtained toner base particles. May be. In this case, the mechanical impact force can be applied to the toner base particles using a device such as a hybridizer or mechanofusion.

The suspension polymerization method is an oil-soluble polymerization initiator, emulsification described later in an aqueous medium in which a colorant, a release agent, and the like are dispersed in a polymerizable monomer and a surfactant and other solid dispersant are contained. Emulsified and dispersed by the method. Thereafter, a polymerization reaction is performed to form particles, and then wet processing for attaching inorganic fine particles to the toner particle surfaces in the present invention may be performed. At that time, it is preferable to treat the toner particles from which excess surfactant and the like are removed by washing.
Examples of the polymerizable monomer include acrylic acids, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid, maleic anhydride, and other acids, acrylamide, By using a part of acrylate or methacrylate having amino groups such as methacrylamide, diacetone acrylamide or their methylol compounds, vinyl pyridine, vinyl pyrrolidone, vinyl imidazole, ethyleneimine, dimethylaminoethyl methacrylate, etc. on the toner particle surface. Functional groups can be introduced.
Further, by selecting a dispersant having an acid group or a basic group as a dispersant to be used, the dispersant can be adsorbed and left on the particle surface to introduce a functional group.

  As the emulsion polymerization method, a water-soluble polymerization initiator and a polymerizable monomer are emulsified in water using a surfactant, and a latex is synthesized by a usual emulsion polymerization method. Separately, a dispersion in which a colorant, a release agent and the like are dispersed in an aqueous medium is prepared, and after mixing, the toner is aggregated to a toner size and heat-fused to obtain a toner. Thereafter, wet processing of inorganic fine particles described later may be performed. A functional group can be introduced on the surface of the toner particles by using a latex similar to the monomer that can be used in the suspension polymerization method.

In the present invention, among these, since the selectivity of the resin is high, the low-temperature fixability is high, the granulation property is excellent, and the particle size, the particle size distribution, and the shape can be easily controlled. A toner solution containing an active hydrogen group-containing compound and a polymer capable of reacting with the active hydrogen group-containing compound is dissolved or dispersed in an organic solvent to prepare a toner solution, and then the toner solution is emulsified in an aqueous medium. A dispersion is prepared by dispersing, and in the aqueous medium, the active hydrogen group-containing compound and a polymer capable of reacting with the active hydrogen group-containing compound are reacted to form an adhesive substrate in the form of particles. Those obtained by removing the organic solvent are preferred.
Examples of the toner material include an adhesive base obtained by reacting an active hydrogen group-containing compound, a polymer capable of reacting with the active hydrogen group-containing compound, a binder resin, a release agent, and a colorant. And other components such as resin fine particles and a charge control agent as necessary.

-Adhesive substrate-
The adhesive substrate exhibits adhesiveness to a recording medium such as paper, and is formed by reacting the active hydrogen group-containing compound and a polymer capable of reacting with the active hydrogen group-containing compound in the aqueous medium. It may contain at least a polymer and may further contain a binder resin appropriately selected from known binder resins.

There is no restriction | limiting in particular as a weight average molecular weight of the said adhesive base material, Although it can select suitably according to the objective, For example, 1,000 or more are preferable and 2,000-10,000,000 are more preferable. 3,000 to 1,000,000 are particularly preferred.
When the weight average molecular weight is less than 1,000, the hot offset resistance may be deteriorated.

The storage elastic modulus of the adhesive substrate is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the temperature (TG ′) at which the measurement frequency is 20 Hz is 10,000 dyne / cm ² , Usually, it is 100 ° C. or higher, and preferably 110 to 200 ° C. When the (TG ′) is less than 100 ° C., the hot offset resistance may be deteriorated.
The viscosity of the adhesive substrate is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the temperature (Tη) at which a poise of 1,000 at a measurement frequency of 20 Hz is usually 180 ° C. or less. Yes, 90-160 degreeC is preferable. When the (Tη) exceeds 180 ° C., the low-temperature fixability may be deteriorated.
Therefore, from the viewpoint of achieving both hot offset resistance and low-temperature fixability, the (TG ′) is preferably higher than the (Tη). That is, the difference (TG′−Tη) between (TG ′) and (Tη) is preferably 0 ° C. or higher, more preferably 10 ° C. or higher, and further preferably 20 ° C. or higher. The larger the difference, the better.
Further, from the viewpoint of achieving both low-temperature fixability and heat-resistant storage stability, (TG′−Tη) is preferably 0 to 100 ° C., more preferably 10 to 90 ° C., and still more preferably 20 to 80 ° C.

Specific examples of the adhesive substrate are not particularly limited and may be appropriately selected depending on the intended purpose. Particularly preferred examples include polyester resins.
There is no restriction | limiting in particular as said polyester resin, Although it can select suitably according to the objective, For example, a urea modified polyester resin etc. are mentioned especially suitably.
The urea-modified polyester resin comprises an amine (B) as the active hydrogen group-containing compound and an isocyanate group-containing polyester prepolymer (A) as a polymer that can react with the active hydrogen group-containing compound. It is obtained by reacting in a medium.
The urea-modified polyester resin may contain a urethane bond in addition to the urea bond. In this case, the molar ratio of the urea bond to the urethane bond (urea bond / urethane bond) is particularly limited. However, 100/0 to 10/90 is preferable, 80/20 to 20/80 is more preferable, and 60/40 to 30/70 is particularly preferable.
When the urea bond is less than 10, the hot offset resistance may be deteriorated.

Preferable specific examples of the urea-modified polyester resin include the following (1) to (10), that is, (1) a polyester prepolymer obtained by reacting a polycondensate of bisphenol A ethylene oxide 2 mol adduct and isophthalic acid with isophorone diisocyanate. A mixture of a polymer urealated with isophorone diamine and a polycondensate of bisphenol A ethylene oxide 2 mol adduct and isophthalic acid, and (2) a polycondensate of bisphenol A ethylene oxide 2 mol adduct and isophthalic acid A mixture of a polyester prepolymer reacted with diisocyanate and uread with isophorone diamine, and a polycondensate of bisphenol A ethylene oxide 2 mol adduct and terephthalic acid, (3) bisphenol A ethylene oxide 2 mol A polyester prepolymer obtained by reacting an adduct / bisphenol A propylene oxide 2 mol adduct and a polycondensate of terephthalic acid with isophorone diisocyanate, and urethanized with isophorone diamine, and bisphenol A ethylene oxide 2 mol adduct / bisphenol A propylene. Mixture of oxide 2 mol adduct and polycondensate of terephthalic acid, (4) Bisphenol A ethylene oxide 2 mol adduct / bisphenol A propylene oxide 2 mol adduct and terephthalic acid polycondensate were reacted with isophorone diisocyanate. A mixture of a polyester prepolymer uread with isophoronediamine, a bisphenol A propylene oxide 2-mole adduct and a polycondensate of terephthalic acid, (5) bisphenol A A polyester prepolymer obtained by reacting a polycondensate of tylene oxide 2 mol adduct and terephthalic acid with isophorone diisocyanate and uread with hexamethylenediamine, and a polycondensate of bisphenol A ethylene oxide 2 mol adduct and terephthalic acid (6) Polyester prepolymer obtained by reacting a polycondensate of bisphenol A ethylene oxide with 2 mol of bisphenol A and isophorone diisocyanate with urea and hexamethylenediamine and 2 mol of bisphenol A ethylene oxide. Product / bisphenol A propylene oxide 2 mol adduct and terephthalic acid polycondensate, (7) bisphenol A ethylene oxide 2 mol adduct and terephthalic acid polycondensate A mixture of a polyester prepolymer reacted with socyanate with urethanized with ethylenediamine and a polycondensate of bisphenol A ethylene oxide 2 mol adduct and terephthalic acid, (8) bisphenol A ethylene oxide 2 mol adduct and isophthalic acid (9) Bisphenol A ethylene, a mixture of a polyester prepolymer obtained by reacting a polycondensate of bisphenol with diphenylmethane diisocyanate and uread with hexamethylene diamine, a bicondensate of bisphenol A ethylene oxide and a polycondensate of isophthalic acid, Polyester prepolymer obtained by reacting a polycondensate of oxide 2 mol adduct / bisphenol A propylene oxide 2 mol adduct and terephthalic acid / dodecenyl succinic anhydride with diphenylmethane diisocyanate Mixture of uremer urea-modified with hexamethylenediamine and bisphenol A ethylene oxide 2-mole adduct / bisphenol A propylene oxide 2-mole adduct and terephthalic acid polycondensate, (10) bisphenol A ethylene oxide 2-mole addition And a mixture of a polyester prepolymer obtained by reacting a polycondensate of isophthalic acid and isophthalic acid with toluene diisocyanate with urea methylenediamine, a 2-mole adduct of bisphenol A ethylene oxide and a polycondensate of isophthalic acid, etc. Preferably mentioned.

-Active hydrogen group-containing compound-
The active hydrogen group-containing compound acts as an elongation agent, a crosslinking agent, or the like when a polymer capable of reacting with the active hydrogen group-containing compound undergoes an elongation reaction, a crosslinking reaction, or the like in the aqueous medium.
The active hydrogen group-containing compound is not particularly limited as long as it has an active hydrogen group, and can be appropriately selected depending on the purpose. For example, the polymer capable of reacting with the active hydrogen group-containing compound is In the case of the isocyanate group-containing polyester prepolymer (A), the amines (B) can be increased in molecular weight by a reaction such as an elongation reaction or a crosslinking reaction with the isocyanate group-containing polyester prepolymer (A). Is preferred.
There is no restriction | limiting in particular as said active hydrogen group, According to the objective, it can select suitably, For example, a hydroxyl group (alcoholic hydroxyl group or phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, an alcoholic hydroxyl group is particularly preferable.

The amines (B) are not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include diamine (B1), trivalent or higher polyamine (B2), amino alcohol (B3), and amino mercaptan. (B4), amino acid (B5), and those obtained by blocking the amino groups of B1 to B5 (B6).
These may be used individually by 1 type and may use 2 or more types together. Among these, diamine (B1), a mixture of diamine (B1) and a small amount of a trivalent or higher polyamine (B2) are particularly preferable.

Examples of the diamine (B1) include aromatic diamines, alicyclic diamines, and aliphatic diamines. Examples of the aromatic diamine include phenylenediamine, diethyltoluenediamine, 4,4′diaminodiphenylmethane, and the like. Examples of the alicyclic diamine include 4,4′-diamino-3,3′dimethyldicyclohexylmethane, diaminecyclohexane, and isophoronediamine. Examples of the aliphatic diamine include ethylene diamine, tetramethylene diamine, and hexamethylene diamine.
Examples of the trivalent or higher polyamine (B2) include diethylenetriamine and triethylenetetramine.
Examples of the amino alcohol (B3) include ethanolamine and hydroxyethylaniline.
Examples of the amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan.
Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid.
Examples of the block (B6) in which the amino group of B1 to B5 is blocked include, for example, a ketimine obtained from any of the amines (B1) to (B5) and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.) Compounds, oxazolyzone compounds, and the like.

  In addition, a reaction terminator can be used to stop the elongation reaction, the crosslinking reaction, etc. between the active hydrogen group-containing compound and the polymer capable of reacting with the active hydrogen group-containing compound. Use of the reaction terminator is preferable in that the molecular weight and the like of the adhesive substrate can be controlled within a desired range. Examples of the reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.) or those blocked (ketimine compounds).

As a mixing ratio of the amines (B) and the isocyanate group-containing polyester prepolymer (A), the isocyanate group [NCO] in the isocyanate group-containing prepolymer (A) and the amines (B) The mixing equivalent ratio ([NCO] / [NHx]) of the amino group [NHx] is preferably 1/3 to 3/1, more preferably 1/2 to 2/1, It is particularly preferably 1.5 to 1.5 / 1.
If the mixing equivalent ratio ([NCO] / [NHx]) is less than 1/3, the low-temperature fixability may decrease. If it exceeds 3/1, the molecular weight of the urea-modified polyester resin will be low. The hot offset resistance may be deteriorated.

--Polymer capable of reacting with active hydrogen group-containing compound--
The polymer capable of reacting with the active hydrogen group-containing compound (hereinafter sometimes referred to as “prepolymer”) is not particularly limited as long as it has at least a site capable of reacting with the active hydrogen group-containing compound. However, it can be appropriately selected from known resins, and examples thereof include polyol resins, polyacrylic resins, polyester resins, epoxy resins, and derivative resins thereof.
These may be used individually by 1 type and may use 2 or more types together. Among these, a polyester resin is particularly preferable in terms of high fluidity and transparency during melting.

The site capable of reacting with the active hydrogen group-containing compound in the prepolymer is not particularly limited and may be appropriately selected from known substituents. For example, an isocyanate group, an epoxy group, a carboxylic acid, An acid chloride group, and the like.
These may be contained singly or in combination of two or more. Among these, an isocyanate group is particularly preferable.

Among the prepolymers, it is easy to adjust the molecular weight of the polymer component, and oil-less low-temperature fixing characteristics in dry toners, in particular, good releasability and fixability even in the absence of a release oil application mechanism to a heating medium for fixing. It is particularly preferable that it is a urea bond-forming group-containing polyester resin (RMPE) in that it can be secured.
As said urea bond production | generation group, an isocyanate group etc. are mentioned, for example. When the urea bond-forming group in the urea bond-forming group-containing polyester resin (RMPE) is the isocyanate group, the isocyanate group-containing polyester prepolymer (A) and the like are particularly preferable as the polyester resin (RMPE). It is done.

  The isocyanate group-containing polyester prepolymer (A) is not particularly limited and may be appropriately selected depending on the intended purpose. For example, it is a polycondensate of a polyol (PO) and a polycarboxylic acid (PC), And what made the said active hydrogen group containing polyester resin react with polyisocyanate (PIC), etc. are mentioned.

  There is no restriction | limiting in particular as said polyol (PO), According to the objective, it can select suitably, For example, diol (DIO), trihydric or more polyol (TO), diol (DIO), and trihydric or more polyol And a mixture with (PO). These may be used individually by 1 type and may use 2 or more types together. Among these, the diol (DIO) alone or a mixture of the diol (DIO) and a small amount of the trivalent or higher polyol (PO) is preferable.

Examples of the diol (DIO) include alkylene glycol, alkylene ether glycol, alicyclic diol, alkylene oxide adduct of alicyclic diol, bisphenol, alkylene oxide adduct of bisphenol, and the like.
The alkylene glycol is preferably one having 2 to 12 carbon atoms, such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, and the like. Can be mentioned. Examples of the alkylene ether glycol include diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, and the like. Examples of the alicyclic diol include 1,4-cyclohexanedimethanol and hydrogenated bisphenol A. Examples of the alkylene oxide adduct of the alicyclic diol include those obtained by adding an alkylene oxide such as ethylene oxide, propylene oxide, butylene oxide to the alicyclic diol. Examples of the bisphenols include bisphenol A, bisphenol F, and bisphenol S. Examples of the alkylene oxide adduct of the bisphenol include those obtained by adding an alkylene oxide such as ethylene oxide, propylene oxide, butylene oxide to the bisphenol.
Among these, alkylene glycols having 2 to 12 carbon atoms, alkylene oxide adducts of bisphenols, and the like are preferable. Mixtures are particularly preferred.

The trivalent or higher polyol (PO) is preferably 3 to 8 or higher, for example, a trihydric or higher polyhydric aliphatic alcohol, a trivalent or higher polyphenol, a trivalent or higher polyphenol. And alkylene oxide adducts.
Examples of the trihydric or higher polyhydric aliphatic alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol and the like. Examples of the trihydric or higher polyphenols include trisphenol PA, phenol novolak, cresol novolak, and the like. Examples of the trivalent or higher polyphenols alkylene oxide adducts include those obtained by adding an alkylene oxide such as ethylene oxide, propylene oxide, butylene oxide to the trivalent or higher polyphenols.

  The mixture mass ratio (DIO: PO) of the diol (DIO) and the trivalent or higher polyol (PO) in the mixture of the diol (DIO) and the trivalent or higher polyol (PO) is 100: 0.01-10 are preferable and 100: 0.01-1 are more preferable.

There is no restriction | limiting in particular as said polycarboxylic acid (PC), Although it can select suitably according to the objective, For example, dicarboxylic acid (DIC), trivalent or more polycarboxylic acid (PC), dicarboxylic acid (DIC) ) And a tri- or higher valent polycarboxylic acid.
These may be used individually by 1 type and may use 2 or more types together. Among these, dicarboxylic acid (DIC) alone or a mixture of DIC and a small amount of trivalent or higher polycarboxylic acid (PC) is preferable.
Examples of the dicarboxylic acid include alkylene dicarboxylic acid, alkenylene dicarboxylic acid, aromatic dicarboxylic acid, and the like.
Examples of the alkylene dicarboxylic acid include succinic acid, adipic acid, and sebacic acid. As said alkenylene dicarboxylic acid, a C4-C20 thing is preferable, For example, a maleic acid, a fumaric acid, etc. are mentioned. As said aromatic dicarboxylic acid, a C8-C20 thing is preferable, For example, a phthalic acid, isophthalic acid, a terephthalic acid, naphthalene dicarboxylic acid etc. are mentioned.
Among these, alkenylene dicarboxylic acid having 4 to 20 carbon atoms and aromatic dicarboxylic acid having 8 to 20 carbon atoms are preferable.

The trivalent or higher polycarboxylic acid (PO) is preferably 3 to 8 or higher, and examples thereof include aromatic polycarboxylic acids.
The aromatic polycarboxylic acid preferably has 9 to 20 carbon atoms, and examples thereof include trimellitic acid and pyromellitic acid.

  Examples of the polycarboxylic acid (PC) include the dicarboxylic acid (DIC), the trivalent or higher polycarboxylic acid (PC), and a mixture of the dicarboxylic acid (DIC) and the trivalent or higher polycarboxylic acid. Any acid anhydride or lower alkyl ester selected from can also be used. Examples of the lower alkyl ester include methyl ester, ethyl ester, isopropyl ester and the like.

  Mixing mass ratio (DIC: PC) of the dicarboxylic acid (DIC) and the trivalent or higher polycarboxylic acid (PC) in the mixture of the dicarboxylic acid (DIC) and the trivalent or higher polycarboxylic acid (TC) There is no restriction | limiting in particular, According to the objective, it can select suitably, For example, 100: 0.01-10 are preferable and 100: 0.01-1 are more preferable.

  The mixing ratio for the polycondensation reaction between the polyol (PO) and the polycarboxylic acid (PC) is not particularly limited and may be appropriately selected depending on the intended purpose. For example, in the polyol (PO) The equivalent ratio ([OH] / [COOH]) of the hydroxyl group [OH] to the carboxyl group [COOH] in the polycarboxylic acid (PC) is usually preferably 2/1 to 1/1. More preferably, it is 0.5 / 1 to 1/1, and particularly preferably 1.3 / 1 to 1.02 / 1.

There is no restriction | limiting in particular as content in the said isocyanate group containing polyester prepolymer (A) of the said polyol (PO), Although it can select suitably according to the objective, For example, 0.5-40 mass% is preferable. 1-30 mass% is more preferable, and 2-20 mass% is especially preferable.
When the content is less than 0.5% by mass, the hot offset resistance deteriorates, and it may be difficult to achieve both the heat-resistant storage stability and the low-temperature fixability of the toner, and exceeds 40% by mass. In some cases, the low-temperature fixability may deteriorate.

There is no restriction | limiting in particular as said polyisocyanate (PIC), Although it can select suitably according to the objective, For example, aliphatic polyisocyanate, alicyclic polyisocyanate,
Aromatic diisocyanates, araliphatic diisocyanates, isocyanurates, those phenol derivatives, oximes, caprolactams and the like blocked.
Examples of the aliphatic polyisocyanate include tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, trimethylhexane diisocyanate, Examples include tetramethylhexane diisocyanate. Examples of the alicyclic polyisocyanate include isophorone diisocyanate and cyclohexylmethane diisocyanate. Examples of the aromatic diisocyanate include tolylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, diphenylene-4,4′-diisocyanate, 4,4′-diisocyanato-3,3′-dimethyldiphenyl, 3- Examples thereof include methyldiphenylmethane-4,4′-diisocyanate, diphenyl ether-4,4′-diisocyanate and the like. Examples of the araliphatic diisocyanate include α, α, α ′, α′-tetramethylxylylene diisocyanate. Examples of the isocyanurates include tris-isocyanatoalkyl-isocyanurate and triisocyanatocycloalkyl-isocyanurate.
These can be used alone or in combination of two or more.

As a mixing ratio when reacting the polyisocyanate (PIC) and the active hydrogen group-containing polyester resin (for example, a hydroxyl group-containing polyester resin), the isocyanate group [NCO] in the polyisocyanate (PIC) and the hydroxyl group-containing The mixing equivalent ratio ([NCO] / [OH]) with the hydroxyl group [OH] in the polyester resin is usually preferably 5/1 to 1/1, and 4/1 to 1.2 / 1. Is more preferable, and 3/1 to 1.5 / 1 is particularly preferable.
When the isocyanate group [NCO] exceeds 5, low-temperature fixability may be deteriorated, and when it is less than 1, offset resistance may be deteriorated.

There is no restriction | limiting in particular as content in the said isocyanate group containing polyester prepolymer (A) of the said polyisocyanate (PIC), Although it can select suitably according to the objective, For example, 0.5-40 mass% is Preferably, 1-30 mass% is more preferable, and 2-20 mass% is still more preferable.
When the content is less than 0.5% by mass, the hot offset resistance is deteriorated, and it may be difficult to achieve both heat-resistant storage stability and low-temperature fixability. When the content exceeds 40% by mass, Low temperature fixability may deteriorate.

The average number of isocyanate groups contained per molecule of the isocyanate group-containing polyester prepolymer (A) is preferably 1 or more, more preferably 1.2 to 5, and more preferably 1.5 to 4.
When the average number of the isocyanate groups is less than 1, the molecular weight of the polyester resin (RMPE) modified with the urea bond-forming group is lowered, and the hot offset resistance may be deteriorated.

  The weight average molecular weight (Mw) of the polymer capable of reacting with the active hydrogen group-containing compound is 1,000 to 30,000 in terms of molecular weight distribution by GPC (gel permeation chromatography) soluble in tetrahydrofuran (THF). Preferably, 1,500-15,000 are more preferable. When the weight average molecular weight (Mw) is less than 1,000, the heat resistant storage stability may be deteriorated, and when it exceeds 30,000, the low temperature fixability may be deteriorated.

The measurement of the molecular weight distribution by the gel permeation chromatography (GPC) can be performed, for example, as follows.
That is, first, the column is stabilized in a 40 ° C. heat chamber. At this temperature, tetrahydrofuran (THF) as a column solvent is allowed to flow at a flow rate of 1 ml / min, and 50 to 200 μl of a tetrahydrofuran sample solution of a resin whose sample concentration is adjusted to 0.05 to 0.6 mass% is injected and measured. In measuring the molecular weight of the sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of the calibration curve created by several monodisperse polystyrene standard samples and the count number. Examples of standard polystyrene samples for preparing the calibration curve include Pressure Chemical Co. Or the molecular weight made by Toyo Soda Industry Co., Ltd. 6 × 102, 2.1 × 102, 4 × 102, 1.75 × 104, 1.1 × 105, 3.9 × 105, 8.6 × 105, 2 × 106 and 4.48 × 10 6 are used, and at least about 10 standard polystyrene samples are preferably used. As the detector, an RI (refractive index) detector can be used.

--Binder resin--
There is no restriction | limiting in particular as said binder resin, According to the objective, it can select suitably, For example, although a polyester resin etc. are mentioned, Undenatured polyester resin (unmodified polyester resin) is especially preferable.
When the unmodified polyester resin is contained in the toner, low-temperature fixability and glossiness can be improved.
Examples of the unmodified polyester resin include those similar to the urea bond-forming group-containing polyester resin, that is, a polycondensate of a polyol (PO) and a polycarboxylic acid (PC). The unmodified polyester resin is partially compatible with the urea bond-forming group-containing polyester resin (RMPE), that is, has a similar structure that is compatible with each other. It is preferable in terms of resistance to hot offset.

  The weight average molecular weight (Mw) of the unmodified polyester resin is preferably 1,000 to 30,000, preferably 1,500 to 15, in terms of molecular weight distribution by GPC (gel permeation chromatography) soluble in tetrahydrofuran (THF). 1,000 is more preferable. When the weight average molecular weight (Mw) is less than 1,000, the heat resistant storage stability may be deteriorated. Therefore, as described above, the content of the component having the weight average molecular weight (Mw) of less than 1,000. Is required to be 8 to 28% by mass. On the other hand, when the weight average molecular weight (Mw) exceeds 30,000, the low-temperature fixability may be deteriorated.

The glass transition temperature of the unmodified polyester resin is usually 30 to 70 ° C, more preferably 35 to 70 ° C, still more preferably 35 to 50 ° C, and particularly preferably 35 to 45 ° C. When the glass transition temperature is less than 30 ° C., the heat-resistant storage stability of the toner may be deteriorated, and when it exceeds 70 ° C., the low-temperature fixability may be insufficient.
The hydroxyl value of the unmodified polyester resin is preferably 5 mgKOH / g, more preferably 10 to 120 mgKOH / g, and still more preferably 20 to 80 mgKOH / g. If the hydroxyl value is less than 5 mgKOH / g, it may be difficult to achieve both heat-resistant storage stability and low-temperature fixability.

The acid value of the unmodified polyester resin is preferably 1.0 to 50.0 mgKOH / g, more preferably 1.0 to 45.0 mgKOH / g, and still more preferably 15.0 to 45.0 mgKOH / g. Generally, it becomes easy to be negatively charged by giving the toner an acid value.
When the unmodified polyester resin is contained in the toner, the mixing mass ratio (RMPE / PE) of the urea bond-forming group-containing polyester resin (RMPE) and the unmodified polyester resin (PE) is 5/95. ~ 25/75 is preferred, 10 / 90-25 / 7
5 is more preferable.

When the mixing mass ratio of the unmodified polyester resin (PE) exceeds 95, the hot offset resistance is deteriorated, and it may be difficult to achieve both heat-resistant storage stability and low-temperature fixability. Glossiness may deteriorate.
As content of the said non-modified polyester resin in the said binder resin, 50-100 mass% is preferable, for example, 70-95 mass% is more preferable, 80-90 mass% is still more preferable. When the content is less than 50% by mass, the low-temperature fixability and the glossiness of the image may be deteriorated.

-Other ingredients-
The other components are not particularly limited and may be appropriately selected depending on the purpose. For example, colorants, mold release agents, charge control agents, inorganic fine particles, fluidity improvers, cleaning improvers, magnetic properties, and the like. Materials, metal soaps, and the like.

The colorant is not particularly limited and may be appropriately selected from known dyes and pigments according to the purpose. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Lead Red, Lead Red, Cadmium Red, Cad Muum Mercury Red, Antimon Zhu, Permanent Red 4R, PA Red, Faise Red, Parachlor Ortho Nitroaniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Risor Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pogment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon, Oh Lured, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), Indigo, Ultramarine Blue, Bitumen, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Oxidation Chrome, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Ash Examples include green lake, malachite green lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc white, and lithobon.
These may be used individually by 1 type and may use 2 or more types together.

The content of the colorant in the toner is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1 to 15% by mass, and more preferably 3 to 10% by mass.
When the content is less than 1% by mass, a reduction in the coloring power of the toner is observed. When the content exceeds 15% by mass, poor pigment dispersion in the toner occurs, the coloring power decreases, The characteristics may be degraded.

  The colorant may be used as a master batch combined with a resin. The resin is not particularly limited and may be appropriately selected from known ones according to the purpose. For example, styrene or a substituted polymer thereof, a styrene copolymer, polymethyl methacrylate, polybutyl methacrylate , Polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic hydrocarbon resin, alicyclic ring Aromatic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin, and the like. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the polymer of styrene or a substituted product thereof include polyester resin, polystyrene, poly p-chlorostyrene, polyvinyl toluene, and the like. Examples of the styrene copolymer include a styrene-p-chlorostyrene copolymer, a styrene-propylene copolymer, a styrene-vinyltoluene copolymer, a styrene-vinylnaphthalene copolymer, and a styrene-methyl acrylate copolymer. Polymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene- Butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene An acrylonitrile-indene copolymer, Styrene - maleic acid copolymer, styrene - maleic acid ester copolymer, and the like.

  The masterbatch can be produced by mixing or kneading the masterbatch resin and the colorant under high shear. At this time, it is preferable to add an organic solvent in order to enhance the interaction between the colorant and the resin. Also, the so-called flushing method is preferable in that the wet cake of the colorant can be used as it is, and there is no need to dry it. This flushing method is a method of mixing or kneading an aqueous paste containing water of a colorant together with a resin and an organic solvent, and transferring the colorant to the resin side to remove moisture and organic solvent components. For the mixing or kneading, for example, a high shear dispersion device such as a three-roll mill is preferably used.

There is no restriction | limiting in particular as said mold release agent, According to the objective, it can select suitably from well-known things, For example, waxes etc. are mentioned suitably.
Examples of the waxes include carbonyl group-containing waxes, polyolefin waxes, and long-chain hydrocarbons. These may be used individually by 1 type and may use 2 or more types together. Among these, a carbonyl group-containing wax is preferable.
Examples of the carbonyl group-containing wax include polyalkanoic acid esters, polyalkanol esters, polyalkanoic acid amides, polyalkylamides, dialkyl ketones, and the like. Examples of the polyalkanoic acid ester include carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, and 1,18-octadecane. Examples thereof include diol distearate. Examples of the polyalkanol ester include tristearyl trimellitic acid and distearyl maleate. Examples of the polyalkanoic acid amide include dibehenyl amide. Examples of the polyalkylamide include trimellitic acid tristearylamide. Examples of the dialkyl ketone include distearyl ketone. Of these carbonyl group-containing waxes, polyalkanoic acid esters are particularly preferred.
Examples of the polyolefin wax include polyethylene wax and polypropylene wax.
Examples of the long chain hydrocarbon include paraffin wax and sazol wax.

There is no restriction | limiting in particular as melting | fusing point of the said mold release agent, Although it can select suitably according to the objective, 40-160 degreeC is preferable, 50-120 degreeC is more preferable, 60-90 degreeC is especially preferable.
When the melting point is less than 40 ° C., the wax may adversely affect the heat-resistant storage stability, and when it exceeds 160 ° C., cold offset may easily occur during fixing at a low temperature.
The melt viscosity of the release agent is preferably 5 to 1000 cps, more preferably 10 to 100 cps, as a measured value at a temperature 20 ° C. higher than the melting point of the wax.
If the melt viscosity is less than 5 cps, the releasability may be lowered, and if it exceeds 1000 cps, the effect of improving hot offset resistance and low-temperature fixability may not be obtained.

There is no restriction | limiting in particular as content in the said toner of the said mold release agent, Although it can select suitably according to the objective, 0-40 mass% is preferable and 3-30 mass% is more preferable.
When the content exceeds 40% by mass, the fluidity of the toner may be deteriorated.

The charge control agent is not particularly limited and may be appropriately selected from known ones according to the purpose. However, since a color tone may change when a colored material is used, a colorless or nearly white material may be used. Preferably, for example, triphenylmethane dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus alone or compounds thereof, tungsten Examples thereof include a single substance or a compound thereof, a fluorine-based activator, a metal salt of salicylic acid, and a metal salt of a salicylic acid derivative. These may be used individually by 1 type and may use 2 or more types together.
Commercially available products may be used as the charge control agent. Examples of the commercially available products include quaternary ammonium salt Bontron P-51, oxynaphthoic acid metal complex E-82, and salicylic acid metal complex. E-84, phenolic condensate E-89 (above, manufactured by Orient Chemical Co., Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, manufactured by Hodogaya Chemical Co., Ltd.), fourth Copy charge PSY VP2038 of quaternary ammonium salt, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR which is a boron complex -147 (manufactured by Nippon Carlit), quinacridone, azo pigments, other sulfonic acid groups, carbo Sill group, polymer compounds having a functional group such as quaternary ammonium salts, and the like.
The charge control agent may be melted and kneaded with the master batch and then dissolved or dispersed, or may be added together with the toner components when directly dissolving or dispersing in the organic solvent, or The toner particles may be fixed on the toner surface after production.

  The content of the charge control agent in the toner varies depending on the type of the binder resin, the presence / absence of an additive, a dispersion method, and the like, and cannot be generally specified. On the other hand, 0.1-10 mass parts is preferable, and 0.2-5 mass parts is more preferable. When the content is less than 0.1 parts by mass, the charge controllability may not be obtained. When the content exceeds 10 parts by mass, the chargeability of the toner becomes too large, and the effect of the main charge control agent is reduced. As a result, the electrostatic attractive force with the developing roller increases, which may lead to a decrease in developer fluidity and a decrease in image density.

-Resin fine particles-
The resin fine particle is not particularly limited as long as it is a resin that can form an aqueous dispersion in an aqueous medium, and can be appropriately selected from known resins according to the purpose, and may be a thermoplastic resin. It may be a thermosetting resin, for example, vinyl resin, polyurethane resin, epoxy resin, polyester resin, polyamide resin, polyimide resin, silicon resin, phenol resin, melamine resin, urea resin, aniline resin, ionomer resin, polycarbonate. Examples of the resin include vinyl resins. Of these, vinyl resins are particularly preferable.
These may be used individually by 1 type and may use 2 or more types together. Among these, it is preferably formed of at least one selected from a vinyl resin, a polyurethane resin, an epoxy resin, and a polyester resin in that an aqueous dispersion of fine spherical resin resin particles can be easily obtained.

The vinyl resin is a polymer obtained by homopolymerizing or copolymerizing a vinyl monomer. For example, a styrene- (meth) acrylic acid ester resin, a styrene-butadiene copolymer, a (meth) acrylic acid-acrylic acid ester polymer. Styrene-acrylonitrile copolymer, styrene-maleic anhydride copolymer, styrene- (meth) acrylic acid copolymer, and the like.
Further, as the resin fine particles, a copolymer comprising a monomer having at least two unsaturated groups can be used.
The monomer having at least two unsaturated groups is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a sodium salt of ethylene oxide methacrylate adduct sulfate (“Eleminol RS-30”). "; Manufactured by Sanyo Chemical Industries, Ltd.), divinylbenzene, 1,6-hexanediol acrylate, and the like.

  The resin fine particles can be obtained by polymerization according to a known method appropriately selected according to the purpose, but is preferably obtained as an aqueous dispersion of the resin fine particles. The method for preparing the aqueous dispersion of the resin fine particles is, for example, (1) In the case of the vinyl resin, a vinyl monomer is used as a starting material and is selected from suspension polymerization, emulsion polymerization, seed polymerization, and dispersion polymerization. (2) In the case of polyaddition or condensation resin such as polyester resin, polyurethane resin, epoxy resin, etc., a precursor (monomer, oligomer). Or the like, or a solvent solution thereof is dispersed in an aqueous medium in the presence of an appropriate dispersant, and then heated or added with a curing agent to be cured to produce an aqueous dispersion of resin fine particles (3) ) In the case of polyaddition or condensation resin such as polyester resin, polyurethane resin, epoxy resin, etc., it may be a precursor (monomer, oligomer, etc.) or a solvent solution thereof (liquid). (4) Preliminary polymerization reaction (addition polymerization, ring-opening polymerization, polyaddition, addition) After the resin prepared by any polymerization reaction mode such as condensation and condensation polymerization is pulverized using a mechanical pulverizer or jet type pulverizer and then classified to obtain resin fine particles , A method of dispersing in water in the presence of an appropriate dispersant, (5) prepared in advance by a polymerization reaction (any polymerization reaction mode such as addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) (6) A polymerization reaction (addition polymerization) in advance, in which resin fine particles are obtained by spraying a resin solution in which the resin is dissolved in a solvent to obtain resin fine particles and then dispersing the resin fine particles in water in the presence of an appropriate dispersant. , Ring-opening polymerization, polyaddition, addition condensation The resin fine particles can be obtained by adding a poor solvent to a resin solution obtained by dissolving a resin prepared in a solvent by a polymerization reaction method such as condensation polymerization or by cooling a resin solution previously dissolved in a solvent by heating. And then removing the solvent to obtain resin particles, and then dispersing the resin particles in water in the presence of a suitable dispersant. (7) Polymerization reaction (addition polymerization, ring-opening polymerization, heavy polymerization) in advance (Any polymerization reaction mode such as addition, addition condensation, and condensation polymerization may be used.) A resin solution prepared by dissolving a resin prepared in a solvent in a solvent is dispersed in an aqueous medium and then heated or heated. (8) A resin prepared in advance by a polymerization reaction (which may be any polymerization reaction mode such as addition polymerization, ring-opening polymerization, polyaddition, addition condensation or condensation polymerization) is used as a solvent. In the dissolved resin solution A method of dissolving a suitable emulsifier and then adding water to carry out phase inversion emulsification is preferable.

  Examples of the toner include toners produced by a known suspension polymerization method, emulsion aggregation method, emulsion dispersion method, etc., and can react with an active hydrogen group-containing compound and the active hydrogen group-containing compound. The toner material containing the polymer is dissolved in an organic solvent to prepare a toner solution, and then the toner solution is dispersed in an aqueous medium to prepare a dispersion, and the active hydrogen group-containing solution is prepared in the aqueous medium. A toner obtained by reacting a compound with a polymer capable of reacting with the active hydrogen group-containing compound to form an adhesive substrate in the form of particles and removing the organic solvent is preferred.

-Toner solution-
The toner solution is prepared by dissolving the toner material in the organic solvent.
-Organic solvent-
The organic solvent is not particularly limited as long as it is a solvent that can dissolve or disperse the toner material, and can be appropriately selected according to the purpose. For example, the boiling point is less than 150 ° C. in terms of ease of removal. Volatile ones are preferred, for example, toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, acetic acid Examples include ethyl, methyl ethyl ketone, and methyl isobutyl ketone. Among these, toluene, xylene, benzene, methylene chloride, 1,2-dichloroethane, chloroform, carbon tetrachloride and the like are preferable, and ethyl acetate is particularly preferable. These may be used individually by 1 type and may use 2 or more types together.
There is no restriction | limiting in particular as the usage-amount of the said organic solvent, According to the objective, it can select suitably, For example, 40-300 mass parts is preferable with respect to 100 mass parts of said toner materials, and 60-140 mass parts is preferable. More preferably, 80-120 mass parts is still more preferable.

-Dispersion-
The dispersion is prepared by dispersing the toner solution in an aqueous medium.
When the toner solution is dispersed in the aqueous medium, a dispersion (oil droplets) made of the toner solution is formed in the aqueous medium.

--- Aqueous medium--
The aqueous medium is not particularly limited and may be appropriately selected from known ones. Examples thereof include water, solvents miscible with water, and mixtures thereof. Among these, Is particularly preferred.
The solvent miscible with water is not particularly limited as long as it is miscible with water, and examples thereof include alcohol, dimethylformamide, tetrahydrofuran, cellosolves, and lower ketones.
Examples of the alcohol include methanol, isopropanol, ethylene glycol and the like. Examples of the lower ketones include acetone and methyl ethyl ketone.
These may be used individually by 1 type and may use 2 or more types together.

The toner solution is preferably dispersed in the aqueous medium with stirring.
The dispersion method is not particularly limited and can be appropriately selected using a known disperser. Examples of the disperser include a low-speed shear disperser, a high-speed shear disperser, and a friction disperser. High pressure jet disperser, ultrasonic disperser, and the like. Among these, a high-speed shearing disperser is preferable in that the particle size of the dispersion (oil droplets) can be controlled to 2 to 20 μm.
When the high-speed shearing disperser is used, conditions such as the rotation speed, dispersion time, and dispersion temperature are not particularly limited and can be appropriately selected according to the purpose. For example, the rotation speed is 1 3,000 to 30,000 rpm is preferable, 5,000 to 20,000 rpm is more preferable, and the dispersion time is preferably 0.1 to 5 minutes in the case of a batch method, and the dispersion temperature is under pressure. 0-150 degreeC is preferable and 40-98 degreeC is more preferable. The dispersion temperature is generally easier to disperse when the temperature is higher.

As an example of the method for producing the toner, a method for producing the toner by forming the adhesive base material in the form of particles will be described below.
In the method of granulating the toner by forming the adhesive base material in the form of particles, for example, the preparation of an aqueous medium phase, the preparation of the toner solution, the preparation of the dispersion, the addition of the aqueous medium, etc. Synthesis of a polymer (prepolymer) capable of reacting with an active hydrogen group-containing compound, synthesis of the active hydrogen group-containing compound, etc.).

The aqueous medium phase can be prepared, for example, by dispersing the resin fine particles in the aqueous medium. There is no restriction | limiting in particular as the addition amount in this aqueous medium of this resin fine particle, According to the objective, it can select suitably, For example, 0.5-10 mass% is preferable.
The toner solution is prepared by adding, in the organic solvent, the active hydrogen group-containing compound, a polymer capable of reacting with the active hydrogen group-containing compound, the colorant, the release agent, the charge control agent, and the unmodified. A toner material such as a polyester resin can be dissolved or dispersed.
In the toner material, components other than the polymer (prepolymer) capable of reacting with the active hydrogen group-containing compound are added when the resin fine particles are dispersed in the aqueous medium in the aqueous medium phase preparation. It may be added and mixed in the aqueous medium, or when the toner solution is added to the aqueous medium phase, it may be added to the aqueous medium phase together with the toner solution.

The dispersion can be prepared by emulsifying and dispersing the previously prepared toner solution in the previously prepared aqueous medium phase. In the emulsification / dispersion, when the active hydrogen group-containing compound and the polymer capable of reacting with the active hydrogen group-containing compound are subjected to an extension reaction or a crosslinking reaction, the adhesive base material is generated.
The adhesive substrate (for example, the urea-modified polyester resin) includes, for example, (1) a polymer that can react with the active hydrogen group-containing compound (for example, the isocyanate group-containing polyester prepolymer (A)). The toner solution is emulsified and dispersed in the aqueous medium phase together with the active hydrogen group-containing compound (for example, the amines (B)) to form a dispersion, and both are subjected to an extension reaction or the like in the aqueous medium phase. (2) The toner solution is emulsified and dispersed in the aqueous medium to which the active hydrogen group-containing compound has been added in advance to form a dispersion, and in the aqueous medium phase (3) The toner solution may be added to and mixed with the aqueous medium, and then the active hydrogen group-containing material may be formed. The compound was added to form a dispersion, it may be generated by elongation reaction or crosslinking reaction from particle interfaces in the aqueous medium phase. In the case of (3), a modified polyester resin is preferentially produced on the surface of the toner to be produced, and a concentration gradient can be provided in the toner particles.

  The reaction conditions for producing the adhesive base material by the emulsification / dispersion are not particularly limited, depending on the combination of the polymer capable of reacting with the active hydrogen group-containing compound and the active hydrogen group-containing compound. The reaction time is preferably 10 minutes to 40 hours, more preferably 2 hours to 24 hours, and the reaction temperature is preferably 0 to 150 ° C, more preferably 40 to 98 ° C.

In the aqueous medium phase, as a method for stably forming the dispersion containing a polymer capable of reacting with the active hydrogen group-containing compound (for example, the isocyanate group-containing polyester prepolymer (A)), for example, In an aqueous medium phase, a polymer capable of reacting with the active hydrogen group-containing compound (for example, the isocyanate group-containing polyester prepolymer (A)), the colorant, the mold release agent, the charge control agent, the unmodified Examples thereof include a method in which the toner solution prepared by dissolving or dispersing the toner material such as polyester resin in the organic solvent is added and dispersed by shearing force. The details of the dispersion method are as described above.

In preparing the dispersion, if necessary, a dispersant is used from the viewpoint of stabilizing the dispersion (oil droplets composed of the toner solution) and sharpening the particle size distribution while obtaining a desired shape. Is preferred.
There is no restriction | limiting in particular as said dispersing agent, According to the objective, it can select suitably, For example, surfactant, a sparingly water-soluble inorganic compound dispersing agent, a polymeric protective colloid, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, surfactants are preferable.

Examples of the surfactant include an anionic surfactant, a cationic surfactant, a nonionic surfactant, and an amphoteric surfactant.
Examples of the anionic surfactant include alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters and the like, and those having a fluoroalkyl group are preferable. Examples of the anionic surfactant having a fluoroalkyl group include a fluoroalkylcarboxylic acid having 2 to 10 carbon atoms or a metal salt thereof, disodium perfluorooctanesulfonylglutamate, 3- [omega-fluoroalkyl (6 carbon atoms). -11) Oxy] -1-alkyl (carbon number 3-4) sodium sulfonate, 3- [omega-fluoroalkanoyl (carbon number 6-8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (Carbon number 11-20) carboxylic acid or its metal salt, perfluoroalkyl carboxylic acid (carbon number 7-13) or its metal salt, perfluoroalkyl (carbon number 4-12) sulfonic acid or its metal salt, perfluoro Octanesulfonic acid diethanolamide, N-propyl-N- (2-hydroxy Ethyl) perfluorooctanesulfonamide, perfluoroalkyl (carbon number 6-10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (carbon number 6-10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (carbon number) 6-16) Ethyl phosphate and the like. Examples of commercially available surfactants having a fluoroalkyl group include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.); Florad FC-93, FC-95, FC-98, FC -129 (manufactured by Sumitomo 3M Co., Ltd.); Unidyne DS-101, DS-102 (manufactured by Daikin Industries, Ltd.); Megafac F-110, F-120, F-113, F-191, F-812, F- 833 (manufactured by Dainippon Ink & Chemicals, Inc.); Xtop EF-102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products); 100, F150 (manufactured by Neos) and the like.

Examples of the cationic surfactant include amine salt type surfactants and quaternary ammonium salt type cationic surfactants. Examples of the amine salt type surfactant include alkylamine salts, aminoalcohol fatty acid derivatives, polyamine fatty acid derivatives, imidazolines, and the like. Examples of the quaternary ammonium salt type cationic surfactant include alkyltrimethylammonium salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, pyridinium salt, alkylisoquinolinium salt, benzethonium chloride and the like. . Among the cationic surfactants, aliphatic quaternary ammonium such as aliphatic primary, secondary or tertiary amine acids having a fluoroalkyl group, perfluoroalkyl (6 to 10 carbon atoms) sulfonamidopropyltrimethylammonium salt, etc. Salts, benzalkonium salts, benzethonium chloride, pyridinium salts, imidazolinium salts, and the like. Commercially available products of the cationic surfactant include, for example, Surflon S-121 (Asahi Glass Co., Ltd.); Florad FC-135 (Sumitomo 3M Co., Ltd.); Unidyne DS-202 (Daikin Industries Co., Ltd.), Megafuck F-150, F-824 (manufactured by Dainippon Ink & Chemicals, Inc.); Xtop EF-132 (manufactured by Tochem Products);

Examples of the nonionic surfactant include fatty acid amide derivatives and polyhydric alcohol derivatives.
Examples of the amphoteric surfactant include alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine, N-alkyl-N, N-dimethylammonium betaine and the like.

Examples of the poorly water-soluble inorganic compound dispersant include tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, and hydroxyapatite.
Examples of the polymeric protective colloid include acids, (meth) acrylic monomers containing hydroxyl groups, vinyl alcohol or ethers of vinyl alcohol, esters of vinyl alcohol and compounds containing carboxyl groups, amides Examples thereof include homopolymers or copolymers of compounds or their methylol compounds, chlorides, those having a nitrogen atom or a heterocyclic ring thereof, polyoxyethylenes, and celluloses.

  Examples of the acids include acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid, maleic anhydride, and the like. Examples of the (meth) acrylic monomer containing a hydroxyl group include β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, and γ-acrylate. -Hydroxypropyl, γ-hydroxypropyl methacrylate, 3-chloro-2-hydroxypropyl acrylate, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate Glycerin monomethacrylate, N-methylol acrylamide, N-methylol methacrylamide and the like. Examples of the vinyl alcohol or ethers with vinyl alcohol include vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, and the like. Examples of the esters of vinyl alcohol and a compound containing a carboxyl group include vinyl acetate, vinyl propionate, and vinyl butyrate. Examples of the amide compound or these methylol compounds include acrylamide, methacrylamide, diacetone acrylamide acid, or these methylol compounds. Examples of the chlorides include acrylic acid chloride and methacrylic acid chloride. Examples of the homopolymer or copolymer such as those having a nitrogen atom or a heterocyclic ring thereof include vinyl pyridine, vinyl pyrrolidone, vinyl imidazole, and ethylene imine. Examples of the polyoxyethylene are polyoxyethylene, polyoxypropylene, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonylphenyl ether, polyoxyethylene Examples thereof include oxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, and polyoxyethylene nonyl phenyl ester. Examples of the celluloses include methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose.

In preparing the dispersion, a dispersion stabilizer can be used as necessary.
Examples of the dispersion stabilizer include acids that are soluble in acids and alkalis such as calcium phosphate.
When the dispersion stabilizer is used, the calcium phosphate salt can be removed from the fine particles by a method of dissolving the calcium phosphate salt with an acid such as hydrochloric acid and then washing with water or a method of decomposing with an enzyme.

In the preparation of the dispersion, a catalyst for the extension reaction or the crosslinking reaction can be used. Examples of the catalyst include dibutyltin laurate and dioctyltin laurate.
The organic solvent is removed from the obtained dispersion (emulsified slurry). The organic solvent is removed by (1) a method of gradually raising the temperature of the entire reaction system to completely evaporate and remove the organic solvent in the oil droplets, and (2) spraying the emulsified dispersion in a dry atmosphere. And a method of completely removing the water-insoluble organic solvent in the oil droplets to form toner fine particles and evaporating and removing the aqueous dispersant together.

  When the organic solvent is removed, toner particles are formed. The toner particles can be washed, dried, etc., and then classified as desired. The classification can be performed, for example, by removing fine particle portions by a cyclone, a decanter, centrifugation, or the like in a liquid, and the classification operation may be performed after obtaining a powder after drying.

Thus, the obtained toner particles are mixed with particles of the colorant, release agent, charge control agent, etc., and further, a mechanical impact force is applied to the release agent from the surface of the toner particles. And the like can be prevented from being detached.
As a method of applying the mechanical impact force, for example, a method of applying an impact force to the mixture with a blade rotating at high speed, an appropriate collision between particles or composite particles by introducing the mixture into a high-speed air stream and accelerating the mixture is accelerated. The method of making it collide with a board, etc. are mentioned. As an apparatus used for this method, for example, an ong mill (manufactured by Hosokawa Micron), an I-type mill (manufactured by Nippon Pneumatic Co., Ltd.) to reduce the pulverization air pressure, a hybridization system (Nara Machinery Co., Ltd.) Product), kryptron system (manufactured by Kawasaki Heavy Industries, Ltd.), automatic mortar, and the like.

  The toner has the following volume average particle diameter (Dv), volume average particle diameter (Dv) / number average particle diameter (Dn), average circularity, shape factors SF-1 and SF-2, and the like. It is preferable.

The volume average particle diameter (Dv) of the toner is, for example, preferably 3 to 8 μm, more preferably 4 to 7, and still more preferably 5 to 6. Here, the volume average particle diameter is defined as Dv = [(Σ (nD3) / Σn) 1/3 (where n is the number of particles and D is the particle diameter).
When the volume average particle size is less than 3 μm, in the case of a two-component developer, the toner may be fused to the surface of the carrier during a long period of stirring in the developing device, and the charging ability of the carrier may be reduced. In the developer, toner filming on the developing roller and toner fusion to a member such as a blade are likely to occur because the toner is thinned. When the thickness exceeds 8 μm, the resolution is high and high. It becomes difficult to obtain an image of an image quality, and when the balance of the toner in the developer is performed, the variation in the particle diameter of the toner may increase.

The ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) in the toner is, for example, preferably 1.25 or less, more preferably 1.00 to 1.20. .10 to 1.20 is more preferable.
When the ratio of the volume average particle diameter to the number average particle diameter (Dv / Dn) is 1.25 or less, the particle size distribution of the toner is relatively sharp and the fixability is improved. If it is less than the above, in the case of a two-component developer, the toner may be fused to the surface of the carrier during a long period of stirring in the developing device, and the charging ability of the carrier may be deteriorated or the cleaning property may be deteriorated. In the case of the agent, toner filming on the developing roller and toner fusion to a member such as a blade are likely to occur because the toner layer is thinned. It becomes difficult to obtain a high-quality image, and when the balance of the toner in the developer is performed, the fluctuation of the toner particle size may increase.

  The volume average particle diameter and the ratio (Dv / Dn) between the volume average particle diameter and the number average particle diameter are measured using, for example, a particle size measuring device “Multisizer II” manufactured by Beckman Coulter, Inc. Can do.

The average circularity is a value obtained by dividing the circumference of an equivalent circle having the same projected shape as the shape of the toner by the circumference of the actual particles, and is preferably 0.900 to 0.98, for example, 0.940 to 0 .98 is more preferred.
When the average circularity is less than 0.900, the toner becomes an irregular shape separated from the spherical shape, and a satisfactory transfer property and a high-quality image free from dust may not be obtained, and exceeds 0.98. In an image forming system that employs blade cleaning or the like, defective cleaning occurs on the photosensitive member and the transfer belt, and in the case of image formation with high image area ratio such as dirt on the image, for example, a photographic image. The toner on which an untransferred image is formed due to a paper feed failure or the like may become a transfer residual toner on the photosensitive member, resulting in background smearing of the image, or the charging roller for contact charging the photosensitive member Etc., and the original charging ability may not be exhibited.
The average circularity is measured, for example, by an optical detection band method in which a suspension containing toner is passed through an imaging unit detection band on a flat plate, and a particle image is optically detected and analyzed by a CCD camera. For example, it can be measured using a flow type particle image analyzer FPIA-2100 (manufactured by Sysmex Corporation).

The shape factors SF-1 and SF-2 are obtained by, for example, randomly sampling 300 SEM images of toner obtained by measurement with Hitachi FE-SEM (S-4200), and using the image information as an interface. And introduced into an image analysis apparatus (Luzex AP) manufactured by Nireco Corp., and analyzed, and values obtained from Equation 1 and Equation 2 below were defined as shape factors SF-1 and SF-2. In addition, although the value calculated | required by Luzex is preferable for the value of SF-1 and SF-2, if the same analysis result is obtained, it will not be specifically limited to the said FE-SEM apparatus and an image analysis apparatus.
<Formula 1>
SF-1 = (L2 / A) × (π / 4) × 100
<Formula 2>
SF-2 = (P2 / A) × (1 / 4π) × 100
Here, L represents the absolute maximum length of the toner, A represents the projected area of the toner, and P represents the maximum circumferential length of the toner.
In addition, if it is a true sphere, both SF-1 and SF-2 will be 100, and will become an indefinite form from a spherical shape as the value becomes larger than 100. In particular, SF-1 represents the shape of the entire toner (ellipse, sphere, etc.), and SF-2 is a shape factor indicating the degree of surface irregularities.

The coloration of the toner is not particularly limited and may be appropriately selected according to the purpose, and may be at least one selected from black toner, cyan toner, magenta toner, and yellow toner. Can be obtained by appropriately selecting the type of the colorant, and is preferably a color toner.
In the present embodiment, the developer including the carrier and toner described above is used in the image forming apparatus shown in FIG. 1 as a replenishing developer and a developing device internal developer, so that it can be used for a long time. Later, film removal on the carrier surface and generation of toner spent on the carrier surface are prevented, and a decrease in the charge amount of the developer in the developer container 14 and a decrease in the electrical resistance value of the carrier can be suppressed. Development characteristics can be obtained.

In addition, since the carrier resistance value of the carrier is significantly reduced or a portion having a low resistance value is locally generated on the surface of the carrier, the occurrence of carrier adhesion in the solid image portion is greatly reduced. Can be suppressed.
For this reason, the fineness of the image is reduced due to the carrier adhesion on the image, or the amount of the developer in the developer container 14 is reduced, thereby causing problems such as image quality deterioration and durability deterioration. Is effectively prevented. For this reason, in use over time, it is possible to maintain good image quality over a long period of time.

In addition, the carrier used in the present embodiment does not contain carbon black that causes color stains, and its resistance value is adjusted, so that image formation for color can be performed while maintaining stable chargeability. Even when used in the apparatus, a high-quality color image with high color reproducibility and fineness can be provided without causing color stains on the image.
The configuration of the image forming apparatus used in the present invention is not limited to the above-described configuration described in the present embodiment, and other configurations may be used as long as they have similar functions. It is also possible to use an image forming apparatus having the same.

EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited thereto. In the following, “parts” means parts by weight, and “%” means percent by weight.
(Example 1)
425 parts of 20% by weight silicone resin solution SR2410 (manufactured by Toray Dow Corning Silicone), 0.858 parts of aminosilane SH6020 (manufactured by Toray Dow Corning Silicone), non-conductive particles having an average particle diameter D of 0 A coating film forming solution was obtained by dispersing 85.4 parts of 3 μm alumina and 300 parts of toluene using a homomixer for 15 minutes. As the core material, a sintered ferrite powder having a weight average particle diameter of 35 μm is used, and a spira coater (manufactured by Okada Seiko Co., Ltd.) is used so that the average film thickness h of the coating film is 0.5 μm. The coating film forming solution was applied to the surface of the core material at 0 ° C. and dried. The obtained carrier was baked in an electric furnace at 300 ° C. for 1 hour. After cooling, the mixture was crushed using a sieve having an opening of 63 μm, containing 50% by weight of alumina, D / h was 0.6, and the average height difference was 0.08 μm.
, Volume resistivity 10 ^14.2 Ω · cm, magnetization obtain carrier of 68 Am ² / kg.

  In addition, the volume average particle diameter of the core material was measured by using an SRA type of a Microtrac particle size analyzer (Nikkiso Co., Ltd.) with a range setting of 0.7 μm or more and 125 μm or less.

The thickness h of the coating layer was obtained from the average value by observing the cross section of the carrier using a transmission electron microscope (TEM), measuring the thickness of the resin portion of the coating layer covering the carrier surface. Specifically, the distance from the carrier cross section to the surface of the arbitrary 50 points of the core material and the surface of the coat layer was measured, and the average of the measured values was obtained as the thickness h (μm).
The average particle diameter D of the particles in the coat layer is obtained by adding 300 ml of a toluene solution to 30 ml of aminosilane (SH6020: manufactured by Toray Dow Corning Silicone) in a juicer mixer. Add 6.0 g of the sample, set the mixer rotation speed to low and disperse for 3 minutes. An appropriate amount of the dispersion is added to 500 ml of a toluene solution prepared in advance in a 1000 ml beaker and diluted. The diluting solution is continuously stirred with a homogenizer. The volume average particle diameter is measured with an ultracentrifugal automatic particle size distribution analyzer CAPA-700 (manufactured by Horiba, Ltd.).

Measurement conditions Rotational speed: 2000rpm
Maximum particle size: 2.0 μm
Minimum particle size: 0.1 μm
Particle size interval: 0.1 μm
Dispersion medium viscosity: 0.59 mPa · s
Dispersion medium density: 0.87 g / cm ³
Particle density: The density of inorganic fine particles is input as a true specific gravity value measured using a dry automatic bulk density meter Accupic 1330 (manufactured by Shimadzu Corporation). For the average height difference, the carrier cross section is observed using a transmission electron microscope (TEM). The thickness of the resin part of the coating layer covering the carrier surface was measured. Specifically, the distance from the carrier cross section to an arbitrary 50 points of the core surface and the coat layer surface is measured, and the average value of 5 points from the large value of the measured value and the 5 points from the small value of the numerical value. The difference from the average was taken.

[Production of toner]
-Synthesis of organic fine particle emulsion-
In a reaction vessel equipped with a stirrer and a thermometer, 683 parts of water, 11 parts of a sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30, Sanyo Chemical Industries, Ltd.), 83 parts of styrene, methacrylic acid When 83 parts, 110 parts of butyl acrylate, and 1 part of ammonium persulfate were charged and stirred at 3800 rpm for 30 minutes, a white emulsion was obtained. This was heated to raise the system temperature to 75 ° C. and reacted for 4 hours. Further, 30 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 6 hours to obtain an aqueous vinyl resin (a copolymer of methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt). A dispersion was obtained. This is designated as [fine particle dispersion 1].
The volume average particle diameter of the fine particles contained in the obtained [fine particle dispersion 1] was measured by a particle size distribution measuring apparatus (“LA-920”, manufactured by Horiba, Ltd.) using a laser light scattering method. there were. Further, a part of [Fine Particle Dispersion 1] was dried to isolate the resin component. The glass transition temperature (Tg) of the resin was 58 ° C., and the weight average molecular weight (Mw) was 130,000.

-Preparation of aqueous phase-
990 parts of water, 83 parts of [fine particle dispersion 1], 37 parts of a 48.3% aqueous solution of sodium dodecyl diphenyl ether disulfonate (Eleminol MON-7, Sanyo Chemical Industries, Ltd.) and 90 parts of ethyl acetate are mixed and stirred. A milky white liquid was obtained. This is designated as [Aqueous Phase 1].
-Synthesis of low molecular weight polyester-
In a reaction vessel equipped with a condenser, a stirrer, and a nitrogen inlet tube, 229 parts of bisphenol A ethylene oxide 2-mole adduct, 529 parts of bisphenol A propylene oxide 3-mole adduct, 208 parts terephthalic acid, 46 parts adipic acid, and 2 parts of dibutyltin oxide was charged and reacted at 230 ° C. for 7 hours under normal pressure. Subsequently, after reacting under reduced pressure of 10 to 15 mmHg for 5 hours, 44 parts of trimellitic anhydride was put in a reaction vessel and reacted at 180 ° C. and normal pressure for 3 hours to obtain [Low molecular weight polyester 1].
The obtained [low molecular weight polyester 1] had a glass transition temperature (Tg) of 43 ° C., a weight average molecular weight (Mw) of 6700, a number average molecular weight of 2300, and an acid value of 25.

-Synthesis of prepolymer-
In a reaction vessel equipped with a condenser, a stirrer, and a nitrogen introduction tube, 682 parts of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, trimellitic anhydride 22 And 2 parts of dibutyltin oxide were added and reacted at 230 ° C. for 7 hours under normal pressure. Further, the reaction was carried out under reduced pressure of 10 to 15 mmHg for 5 hours to obtain [Intermediate Polyester 1].
The obtained [Intermediate polyester 1] has a number average molecular weight of 2200 and a weight average molecular weight of 9700.
The glass transition temperature (Tg) was 54 ° C., the acid value was 0.5, and the hydroxyl value was 52.
Next, 410 parts of [Intermediate polyester 1], 89 parts of isophorone diisocyanate, and 500 parts of ethyl acetate are placed in a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe, and reacted at 100 ° C. for 5 hours. [Prepolymer 1] was obtained.
The free isocyanate of [Prepolymer 1] was obtained. [Anato mass% was 1.53%.

-Synthesis of ketimine-
In a reaction vessel equipped with a stir bar and a thermometer, 170 parts of isophorone diamine and 75 parts of methyl ethyl ketone were charged and reacted at 50 ° C. for 4 and a half hours to obtain [ketimine compound 1].
The amine value of the obtained [ketimine compound 1] was 417.
-Preparation of masterbatch (MB)-
1200 parts of water, 540 parts of carbon black (Printtex 35, manufactured by Degussa) [DBP oil absorption = 42 ml / 100 mg, pH = 9.5], 1200 parts of a polyester resin (manufactured by Sanyo Chemical Industries, Ltd., RS801) are added, and a Henschel mixer is added. (Mitsui Mining Co., Ltd.) The obtained mixture was kneaded at 110 ° C. for 1 hour using two rolls, rolled and cooled, and pulverized with a pulverizer to obtain a carbon black masterbatch. This is designated as [Masterbatch 1].

-Preparation of oil phase-
In a reaction vessel equipped with a stirrer and a thermometer, 378 parts of [Low molecular weight polyester 1], 100 parts of carnauba wax, and 947 parts of ethyl acetate were charged, and the temperature was raised to 80 ° C. with stirring. After maintaining the time, it was cooled to 30 ° C. over 1 hour. Next, 500 parts of [Masterbatch 1] and 500 parts of ethyl acetate were charged in a reaction vessel and mixed for 1 hour to obtain a dissolved product. This is referred to as [Raw material solution 1].
Next, 1324 parts of [Raw Material Solution 1] was transferred to a reaction vessel, and using a bead mill (Ultra Visco Mill, manufactured by IMEX), liquid feeding speed: 1 kg / hr, disk peripheral speed: 6 m / second, 0
. Carbon black and wax were dispersed under the conditions of 5 mm zirconia bead filling amount: 80% by volume and number of passes: 3 times.
Next, 1324 parts of a 65% ethyl acetate solution of [low molecular polyester 1] was added, and a dispersion was obtained using a bead mill under the same conditions as described above, with a pass number of 2 times. This is designated as [Pigment / Wax Dispersion 1].
The obtained [Pigment / Wax Dispersion 1] had a solid content concentration (130 ° C., 30 minutes) of 50%.

-Emulsification-
[Pigment / Wax Dispersion 1] 749 parts, [Prepolymer 1] 115 parts, and [Ketimine Compound 1] 2.9 parts are placed in a reaction vessel, and TK homomixer (manufactured by Tokushu Kika) is used to make 5, Mix for 2 minutes at 000 rpm. Thereafter, 1200 parts of [Aqueous Phase 1] was added to the reaction vessel, and mixed with a TK homomixer at a rotational speed of 13,000 rpm for 25 minutes to obtain an aqueous medium dispersion. This is designated as [Emulsified slurry 1].
-Deorganic solvent-
[Emulsion slurry 1] is put into a reaction vessel equipped with a stirrer and a thermometer, and after removing the solvent at 30 ° C. for 8 hours, aging is performed at 45 ° C. for 4 hours, and the organic solvent is distilled off. A dispersion was obtained. This is designated as [Dispersion Slurry 1].

-Cleaning and drying-
[Dispersion Slurry 1] 100 parts were filtered under reduced pressure, and then washed and dried as follows.
(1) Add 100 parts of deionized water to the filter cake and mix with a TK homomixer (rotation speed: 12)
000 rpm for 10 minutes) and then filtered.
(2) 100 parts of a 10% aqueous sodium hydroxide solution was added to the filter cake of (1), mixed with a TK homomixer (30 minutes at 12,000 rpm), and then filtered under reduced pressure.
(3) 100 parts of 10% hydrochloric acid was added to the filter cake of (2), mixed with a TK homomixer (rotation speed: 12000 rpm for 10 minutes), and then filtered.
(4) Add 100 parts of ion-exchanged water to the filter cake of (3), add an aqueous solution in which a fluorine-based surfactant equivalent to 0.1% of the solid content of the cake is dissolved, and mix with a TK homomixer (at a rotational speed of 12000 rpm). Filtered for 10 minutes).
(5) 300 parts of ion-exchanged water was added to the filter cake of (4), mixed with a TK homomixer (10 minutes at a rotation speed of 12,000 rpm) and then filtered twice to obtain a filter cake.
This filter cake was dried at 45 ° C. for 48 hours with a circulating drier and sieved with a mesh having a mesh size of 75 μm to obtain toner base particles. This is designated as [toner base particle 1].

The obtained “toner base particles 1” were measured for volume average particle size (Dv) and particle size distribution (Dv / Dn), average circularity, and BET specific surface area as follows. The volume average particle diameter (Dv) was 5.8 μm, the particle size distribution (Dv / Dn) was 1.15, the average circularity was 0.950, and the BET specific surface area was 2.60 m ² / g.

<Volume Average Particle Size (Dv) and Particle Size Distribution (Dv / Dn)>
The volume average particle size and particle size distribution of the toner were measured using a particle size measuring device (“Coulter Counter TAII”; manufactured by Coulter Electronics Co., Ltd.) under the condition of an aperture diameter of 100 μm. From these results, (volume average particle diameter / number average particle diameter) was calculated.

<Average circularity>
The average circularity of the toner was measured using a flow particle image analyzer (“FPIA-2100”; manufactured by Toa Medical Electronics Co., Ltd.). Specifically, 0.1 to 0.5 ml of a surfactant (alkylbenzene sulfonate) as a dispersant is added to 100 to 150 ml of water from which impure solids have been removed in advance, and each toner is further added. 0.1 to 0.5 g was added and dispersed. The obtained dispersion was dispersed for about 1 to 3 minutes with an ultrasonic disperser (manufactured by Honda Electronics Co., Ltd.), and the shape and distribution of the toner were measured at a dispersion concentration of 3000 to 10,000 / μl. The average circularity was calculated from these measurement results.

<BET specific surface area>
The BET specific surface areas of the base particles, external additives, and toner particles were measured using an automatic specific surface area / pore distribution measuring device (TriStar 3000: manufactured by Shimadzu Corporation). About 1 sample in the sample cell
. 0 g was weighed and vacuum-dried with a pretreatment smart prep (manufactured by Shimadzu Corporation) for 24 hours to remove impurities and moisture on the sample surface. The pretreated sample is set in TriStar 3000, and the relationship between the nitrogen gas adsorption amount and the relative pressure is obtained. From this relationship, the BET specific surface area of the sample is determined by the BET multipoint method.
In the following examples and comparative examples, any of the following external additives (A) to (D) was used, but the present invention is not limited thereto.
(A)
Hydrophobic silica surface-treated with hexamethyldisilazane having a hydrophobicity of 65% and an average primary particle size of 12 nm. The BET specific surface area of this external additive was measured and found to be 150 m2 / s. (B)
Hydrophobic titanium oxide surface-treated with isobutyltrimethoxysilane having a hydrophobicity of 70% and an average primary particle size of 15 nm The BET specific surface area of this external additive was measured and found to be 58 m2 / s.
To 100 parts of the obtained “toner base particle 1”, 1.5 parts of the external additive (A) is added and mixed for 1 minute under the condition of a peripheral speed of 100 m / s in a hybridization system. 0.5 part of additive (B) was mixed in the same apparatus for 1 minute under the condition of a peripheral speed of 100 m / s. The mixed powder was passed through a mesh having an opening of 100 μm to remove a coarse powder, and a toner A to which a hydrophobic fine powder was externally added was prepared.
Toner A had toner BET specific surface area St: 4.47, Sm + 0.7Ss * X: 4.38, and Sm + 0.97Ss * X: 5.06.

Next, 7 parts of the obtained “Toner 1” and 93 parts of “Carrier 1” were mixed and stirred to prepare a developer having a toner concentration of 7%.
About the obtained developer, an image forming apparatus (Ricoh Co., Ltd., IPSio Color)
8100), an image was output, and image fineness, durability (charge reduction amount, resistance change amount), and solid image carrier adhesion were evaluated as follows. The results are shown in Table 2.

(Charge amount)
The charge amount is a value measured by a general blow-off method [TB-200, manufactured by Toshiba Chemical Co., Ltd.] for a sample that is triboelectrically charged by mixing the toner at a ratio of 7% with respect to 93% of the carrier.
(Volume resistivity)
The volume resistivity is obtained by putting a carrier between the electrodes of the resistance measurement parallel electrode (gap 2 mm), applying DC 1000 V, and converting the resistance value measured after 30 sec with a high resist meter into volume resistivity. It was.

(Image definition)
The image definition was evaluated by the reproducibility of the character image portion. The evaluation method is as follows: a developer is set in a remodeled machine equipped with a developing device shown in FIG. 2 in a commercially available digital full color printer (manufactured by Ricoh Co., Ltd., imgioNeo C600), and the replenishment developer A character chart having a weight ratio of 20 wt% and an image area of 5% (the size of one character is about 2 mm × 2 mm) was output, and the character reproducibility was evaluated by images, and ranked as follows. ◎: Very good, ○: Good, △: Acceptable, ×: Unusable level for practical use, ◎ ○ △ was accepted and × was rejected.

(Skin carrier adhesion)
For the adhesion of the background carrier, set the developer in a remodeling machine equipped with the developing device shown in FIG. 2 in a commercially available digital full-color printer (manufactured by Ricoh Co., Ltd., imagio Neo C600). The weight ratio of the carrier in the agent is 20 wt%, the background potential is fixed at 150 V, and an A3 character chart (1 character size is about 2 mm x 2 mm) with an image area of 1% is output. Evaluation was made based on the number of occurrences, and was ranked as follows. A: 0, O: 2 or more, 5 or less, Δ: 6 or more, 10 or less, x: 11 or more. In addition, (double-circle) was set as the pass and x was set as the disqualification.

(durability)
A developer is set in a remodeled machine equipped with a developing device shown in FIG. 2 in a commercially available digital full-color printer (Ricoh Co., Ltd., Imagio Neo C600), and the replenishment developer has a carrier weight ratio in the replenishment developer. A running evaluation of 100,000 sheets with a single color was performed at 20%. And durability was judged with the charge reduction amount of the carrier which finished this running, and resistance fall amount.
Here, the amount of decrease in the charge amount is obtained by subjecting a sample which is mixed and frictionally charged at a ratio of 7% of toner to 95% of the initial carrier to a general blow-off method (TB-200, manufactured by Toshiba Chemical Corporation). The amount of charge (Q2) measured by the same method as that described above for the carrier from which the toner in the developer after running was removed by the blow-off device from the amount of charge (Q1) measured
Means the amount minus. The target value is within 10.0 μc / g. Further, since the cause of the decrease in the charge amount is the toner spent on the carrier surface, the decrease in the charge amount can be suppressed by reducing the toner spent.
Here, the amount of change in resistance was measured by a high resist meter after 30 seconds after applying an initial carrier between electrodes of a resistance measurement parallel electrode (gap 2 mm) and applying DC 1,000V. The value obtained by converting the obtained value into the volume resistivity (R1), and measuring the carrier obtained by removing the toner in the developer after running with the blow-off device by the same method as the resistance measuring method. It means the amount obtained by subtracting (R2). The target value is within 3.0 [Log (Ω · cm)] in absolute value. Moreover, since the cause of the resistance change is scraping of the carrier coating layer, spent toner component, large particle detachment in the carrier coating layer, etc., the resistance change amount can be suppressed by reducing these.

(Solid image carrier adhesion)
After the above durability evaluation, the digital full-color printer is used to fix the background potential to 150 V, the front solid image is developed on A3 size paper, and the white spots on the obtained image and the number of carriers actually attached Were counted by magnifying glass observation, and the total number of them was used as the solid image carrier adhesion amount. The evaluation was as follows: ◎: 0, ○: 2 or more and 5 or less, Δ: 6 or more and 10 or less, ×: 11 or more. In addition, (double-circle) was set as the pass and x was set as the disqualification.

(Image density)
After outputting a solid image at an adhesion amount of 0.3 ± 0.1 mg / cm ² , which is a low adhesion amount on plain paper transfer paper (Type 6200, manufactured by Ricoh Co., Ltd.), the image density is set to X-Rite (X-Rit
e), and an image density of 1.4 or more was evaluated as ◯, and an image density of less than 1.4 as x.

(Cleanability)
The transfer residual toner on the photosensitive member that has passed the cleaning process after outputting 1,000 sheets of a 95% image area ratio chart is transferred to white paper with Scotch tape (manufactured by Sumitomo 3M Limited), and measured with a Macbeth reflection densitometer RD514 type. The ranking was as follows. A: The difference from the blank is less than 0.005. (Circle): The difference with a blank is 0.005-0.010 (triangle | delta): The difference with a blank is 0.011-0.02. X: The difference with a blank exceeds 0.02.

(Transferability)
After the image area ratio 20% chart is transferred from the photoconductor to the paper, the transfer residual toner on the photoconductor immediately before the cleaning is transferred to a white paper with a scotch tape (manufactured by Sumitomo 3M Co., Ltd.), and is transferred to a Macbeth reflection densitometer RD514 type. Measured and ranked as follows. A: The difference from the blank is less than 0.005. (Circle): The difference with a blank is 0.005-0.010. (Triangle | delta): The difference with a blank is 0.011-0.02. X: The difference with a blank exceeds 0.02.

(Toner scattering)
In an environment with a temperature of 40 ° C. and a humidity of 90% RH, an image forming apparatus (IPSiO, manufactured by Ricoh Co.
Using an evaluation machine that has been tuned by modifying Color 8100) to an oil-less fixing method, the toner contamination state in the copier after the image area ratio 5% chart continuous 100,000 sheet output durability test using each toner is visually observed. The evaluation was as follows. A: The toner is not observed at all and is in a good state. ○: Slight dirt is observed, and there is no problem. Δ: Slightly dirty. X: Very dirty and out of the allowable range.

(Charge stability)
Using each toner, a continuous 100,000 sheet output durability test was conducted using a character image pattern with an image area ratio of 12%, and the change in the charge amount at that time was evaluated. A small amount of developer was collected from the sleeve, and the change in charge amount was determined by the blow-off method, and evaluated as follows. ○: Change in charge amount is less than 5 μc / g. Δ: Change in charge amount is 5 μc / g or more and 10 μc / g or less. X: Change in charge amount exceeds 10 μc / g.

(Filming property)
The filming on the developing roller after the output of 1000 band charts having an image area ratio of 100%, 75%, and 50% and filming on the photosensitive member were observed and evaluated as follows. A: Filming does not occur at all. ○: The occurrence of filming can be confirmed slightly. Δ: Filming occurs in streaks. X: Filming has occurred on the entire surface.
The carrier weight ratio in the replenishment developer was 15%.

(Example 2)
118.69 parts of 50% by weight acrylic resin solution Hitaloid 3001, 37.18 parts of 70% by weight guanamine solution Mycoat 106, 0.68 parts of 40% by weight acidic catalyst catalyst 4040, average particle size D A coating film forming solution was obtained by dispersing 85.4 parts of 0.3 μm alumina and 800 parts of toluene using a homomixer for 15 minutes. Using a sintered ferrite powder having a weight average particle diameter of 35 μm as the core material and forming a coating film at a coater internal temperature of 40 ° C. using a Spira coater so that the average film thickness h of the coating film is 0.5 μm. The solution was applied to the core surface and dried. The obtained carrier was baked in an electric furnace at 150 ° C. for 1 hour. After cooling, the mixture is crushed using a sieve having an aperture of 63 μm, contains 50% by weight of alumina, D / h is 0.6, the average height difference is 0.08 μm, the volume resistivity is 10 ^14.4 Ω · cm, and the magnetization is A carrier of 68 Am ² / kg was obtained. Except for this, the evaluation was performed in the same manner as in Example 1.

(Example 3)
51.61 parts of Hitaroid 3001, 16.12 parts of Mycoat 106, 0.28 parts of Catalyst 4040, 241.5 parts of SR2410, 0.55 parts of SH6020, and alumina having an average particle diameter D of 0.3 μm A coating film forming solution was obtained by dispersing 86.1 parts and 800 parts of toluene using a homomixer for 15 minutes.
A developer was obtained in the same manner as in Example 2 except that such a coating film forming solution was used. The carrier contained 50% by weight of alumina, D / h was 0.55, the average height difference was 0.08 μm, the volume resistivity was 10 ^15.2 Ω · cm, and the magnetization was 68 Am ² / kg.

<Example 4>
A developer was obtained in the same manner as in Example 3 except that the addition amount of alumina having an average particle diameter D of 0.3 μm was changed to 8.6 parts. The carrier had the alumina of containing 9 wt%, D / h of 0.7, an average height difference 1.5 [mu] m, a volume resistivity of 10 ^12.2 Ω · cm, magnetization of 68 Am ² / kg.
Except for this, the evaluation was performed in the same manner as in Example 1.

<Example 5>
A developer was obtained in the same manner as in Example 3 except that the addition amount of alumina having an average particle diameter D of 0.3 μm was changed to 344.4 parts. The carrier contained 80.1% by weight of alumina, D / h was 0.3, the average height difference was 1.8 μm, the volume resistivity was 10 ^16.6 Ω · cm, and the magnetization was 68 Am ² / kg.
Except for this, the evaluation was performed in the same manner as in Example 1.

<Example 6>
A developer was obtained in the same manner as in Example 3 except that the addition amount of alumina having an average particle diameter D of 0.3 μm was changed to 50 parts. The carrier contained 37% by weight of alumina, D / h was 0.66, the average height difference was 1.3 μm, the volume resistivity was 10 ^12.3 Ω · cm, and the magnetization was 68 Am ² / kg.
Except for this, the evaluation was performed in the same manner as in Example 1.

<Example 7>
A developer was obtained in the same manner as in Example 3 except that the addition amount of alumina having an average particle diameter D of 0.3 μm was changed to 250 parts. The carrier contained 74.5% by weight of alumina, D / h was 0.33, the average height difference was 1.5 μm, the volume resistivity was 10 ^16.6 Ω · cm, and the magnetization was 68 Am ² / kg.
Except for this, the evaluation was performed in the same manner as in Example 1.

<Example 8>
A developer was obtained in the same manner as in Example 3 except that the addition amount of alumina having an average particle diameter D of 0.3 μm was changed to 29 parts. The carrier contains 25.2% by weight of alumina,
The coverage was 19.9, D / h was 0.65, the average height difference was 1.1 μm, the volume resistivity was 10 ^13.0 Ω · cm, and the magnetization was 68 Am ² / kg.
Except for this, the evaluation was performed in the same manner as in Example 1.

<Example 9>
A developer was obtained in the same manner as in Example 3 except that the non-conductive particles were changed to titanium oxide having an average particle diameter D of 0.02 μm and the addition amount was 15 parts. The carrier had the titanium oxide contains 14.9 wt%, coverage 3280, D / h of 0.05, an average height difference 0.08 .mu.m, a volume resistivity of 10 ^14.4 Ω · cm, magnetization 66Am ² / Kg.
Except for this, the evaluation was performed in the same manner as in Example 1.

<Example 10>
Except that the surface-treated alumina having an average particle diameter D of 0.35 μm and a volume resistivity of 3.5 Ω · cm was used as the conductive particles instead of the non-conductive particles, and the addition amount was 86.1 parts, A developer was obtained in the same manner as in Example 3. Here, the surface treatment layer has a two-layer structure in which tin dioxide is a lower layer and indium oxide containing tin dioxide is an upper layer. The carrier contained 50% by weight of surface-treated alumina, D / h was 0.63, the average height difference was 0.08 μm, the volume resistivity was 10 ^9.8 Ω · cm, and the magnetization was 68 Am ² / kg.
Except for this, the evaluation was performed in the same manner as in Example 1.

<Example 11>
A developer was obtained in the same manner as in Example 3 except that the addition amount of SR2410 was changed to 350.5 parts and the addition amount of alumina having an average particle diameter D of 0.3 μm was changed to 360.4 parts. The carrier had the alumina was containing 77 wt%, D / h of 0.38, an average height difference 1.8 .mu.m, a volume resistivity of 10 ^17.2 Ω · cm, magnetization of 68 Am ² / kg.
Except for this, the evaluation was performed in the same manner as in Example 1.

<Example 12>
The addition amount of Hitaloid 3001 is 5.2 parts, the addition amount of Mycoat 106 is 1.6 parts, the addition amount of catalyst 4040 is 0.14 parts, the addition amount of SR2410 is 24.15 parts, and non-conductive particles are added. A developer was obtained in the same manner as in Example 3 except that the average particle diameter D was changed to titanium oxide having a thickness of 0.02 μm and the addition amount was changed to 8.5 parts. 50% by weight of fine particles, the average film thickness h of the coating film is 0.04 μm, D / h is 0.5, the average height difference is 0.05 μm, the volume resistivity is 10 ^13.0 Ω · cm, and the magnetization is 68 Am ^2. / Kg.
Except for this, the evaluation was performed in the same manner as in Example 1.

<Example 13>
A developer was obtained in the same manner as in Example 3 except that the addition amount of Hitaloid 3001 was changed to 206.4 parts, the addition amount of Mycoat 106 was changed to 64.4 parts, and the addition amount of SR2410 was changed to 966 parts. It was. The carrier contains 50% by weight of alumina, the average film thickness h of the coating film is 4.3 μm, D / h is 0.07, the average height difference is 0.09 μm, and the volume resistivity is 10 ^16.9 Ω · cm. The magnetization was 68 Am ² / kg.
Except for this, the evaluation was performed in the same manner as in Example 1.

<Example 14>
A developer was obtained in the same manner as in Example 3 except that the addition amount of the hitaloid 3001 was changed to 103.2 parts, the addition amount of the Mycoat 106 was changed to 32.2 parts, and the addition amount of SR2410 was changed to 483 parts. . The carrier contains 33.5% by weight of alumina, the average film thickness h of the coating film is 2.1 μm, D / h is 0.07, the average height difference is 0.06 μm, and the volume resistivity is 10 ^16.8 Ω. -Cm and magnetization were 68 Am < ² > / kg.
Except for this, the evaluation was performed in the same manner as in Example 1.

<Example 15>
A developer was obtained in the same manner as in Example 3 except that sintered ferrite having a weight average particle diameter of 35 μm having a low magnetization was used as the core material. The carrier contained 50% by weight of alumina, D / h was 0.55, the average height difference was 0.08 μm, the volume resistivity was 10 ^15.2 Ω · cm, and the magnetization was 36 Am ² / kg.
Except for this, the evaluation was performed in the same manner as in Example 1.
<Example 16>
A developer was obtained in the same manner as in Example 3 except that sintered ferrite having a weight average particle diameter of 35 μm having high magnetization was used as the core material. The carrier contained 50% by weight of alumina, D / h was 0.55, the average height difference was 0.08 μm, the volume resistivity was 10 ^15.3 Ω · cm, and the magnetization was 94 Am ² / kg.
Except for this, the evaluation was performed in the same manner as in Example 1.

(Example 17)
The carrier weight average particle diameter is 19 μm, the addition amount of the hyalloid 3001 is 206.4 parts, the addition amount of the Mycoat 106 is 64.4 parts, the addition amount of SR2410 is 966 parts, and the addition amount of alumina is 172.2 parts. A developer was obtained in the same manner as Example 3 except for the change. The carrier contained 53% by weight of alumina, had a D / h of 0.52, an average height difference of 1.1 μm, a volume resistivity of 10 ^15.0 Ω · cm, and a magnetization of 66 Am ² / kg.
Except for this, the evaluation was performed in the same manner as in Example 1.
(Example 18)
A developer was obtained in the same manner as in Example 3 except that the weight average particle diameter of the carrier was changed to 67 μm. The carrier contained 49% by weight of alumina, had a D / h of 0.27, an average height difference of 0.055 μm, a volume resistivity of 10 ^12.5 Ω · cm, and a magnetization of 69 Am ² / kg.
Except for this, the evaluation was performed in the same manner as in Example 1.

(Example 19)
In Example 3, the evaluation was performed in the same manner as in Example 3 except that the carrier weight ratio of the replenishment developer was changed to 5%.
(Example 20)
In Example 3, the evaluation was performed in the same manner as in Example 3 except that the carrier weight ratio of the replenishment developer was changed to 2%.

<Comparative Example 1>
The addition amount of Hitaloid 3001 is 25 parts, the addition amount of Mycoat 106 is 8 parts, the addition amount of catalyst 4040 is 0.14 parts, the addition amount of SR2410 is 120.5 parts, and the average particle diameter D is 0.3 μm. A developer was obtained in the same manner as in Example 3 except that the addition amount of alumina was changed to 28.7 parts. The carrier contained 40.5% by weight of alumina, had a D / h of 1.13, an average height difference of 1.95 μm, a volume resistivity of 10 ^13.2 Ω · cm, and a magnetization of 68 Am ² / kg.

<Comparative example 2>
The weight average particle diameter of the carrier is 19 μm, the addition amount of the hyalloid 3001 is 206.4 parts, the addition amount of the Mycoat 106 is 64.4 parts, the addition amount of SR2410 is 966 parts, and the non-conductive particles have an average particle diameter D. A developer was obtained in the same manner as in Example 3 except that the titanium oxide was changed to 0.02 μm and the addition amount was changed to 430 parts. The carrier contained 71.6% by weight of fine particles, had a D / h of 0.009, an average height difference of 0.055 μm, a volume resistivity of 10 ^16.5 Ω · cm, and a magnetization of 68 Am ² / kg.
Except for this, the evaluation was performed in the same manner as in Example 1.

(Comparative Example 3)
Acrylic resin solution (solid content 50% by weight) 56.0 parts
Guanamin solution (solid content 77 wt%) 15.6 parts
Alumina particles [0.3 μm, specific resistance 10 ¹⁴ (Ω · cm)] 160.0 parts
900 parts of toluene
900 parts butyl cellosolve
Was mixed with a homomixer for 10 minutes to prepare a coating film forming solution, which was applied in a Spira coater (manufactured by Okada Seiko Co., Ltd.) to a film thickness of 0.15 μm and dried in the same manner as in Example 3. A developer was obtained. The carrier contains 80% by weight of alumina, D / h is 2.0, the average height difference is 0.01 μm, the volume resistivity is 10 ^15.1 Ω · cm, and the magnetization is 68 Am ² / kg.
Met.
Except for this, the evaluation was performed in the same manner as in Example 1.

(Comparative Example 4)
Acrylic resin solution (solid content 50% by weight) 56.0 parts
Guanamin solution (solid content 77 wt%) 15.6 parts
Silicone resin solution SR2410 (20% by weight) 241.5 parts Alumina particles [0.3 μm, specific resistance 1014 (Ω · cm)] 88.3 parts
900 parts of toluene
Was coated with a homomixer for 10 minutes to prepare a coating film forming solution, which was applied by a Spira coater (manufactured by Okada Seiko Co., Ltd.) to a film thickness of 0.55 μm and dried. The toner was added with 1.5 parts of the external additive (A) to 100 parts of “toner base particles 1” and mixed for 5 minutes with a Henschel mixer at a peripheral speed of 8 m / s. A developer was obtained in the same manner as in Example 3 except that the mixed powder was passed through a mesh having an opening of 100 μm, coarse powder was removed, and toner B was prepared by externally adding hydrophobic fine powder. The carrier contains 50% by weight of alumina, D / h is 0.55, the average height difference is 0.008 μm, the volume resistivity is 10 ^15.1 Ω · cm, the magnetization is 68 Am ² / kg, and the toner B has a toner BET ratio. Surface area St: 4.89, Sm + 0.7Ss * X: 4.
18, Sm + 0.97Ss * X: 4.78.
Except for this, the evaluation was performed in the same manner as in Example 1.

(Comparative Example 5)
A developer was obtained in the same manner as in Example 3 except that the addition amount of alumina having an average particle diameter D of 0.3 μm was changed to 258.1 parts and dispersed for 10 minutes using a homomixer. The carrier contained 68% by weight of alumina, D / h was 0.41, the average height difference was 2.2 μm, the volume resistivity was 10 ^15.2 Ω · cm, and the magnetization was 68 Am ² / kg.
Except for this, the evaluation was performed in the same manner as in Example 1.
(Comparative Example 6)
Toner C production method: To 100 parts of “toner base particle 1”, 1.5 parts of external additive (A) is added and mixed for 1 minute in a hybridization system under the condition of a peripheral speed of 200 m / s. Further, 0.5 part of the external additive (B) was mixed for 1 minute in the same apparatus under the condition of a peripheral speed of 200 m / s. The mixed powder was passed through a mesh having a mesh size of 100 μm to remove a coarse powder and to prepare a toner C to which a hydrophobic fine powder was externally added.
A developer is obtained in the same manner as in Example 3 except that toner C is used, the amount of alumina having an average particle diameter D of 0.3 μm is changed to 258.1 parts, and the mixture is dispersed for 10 minutes using a homomixer. It was. The carrier contains 68% by weight of alumina, D / h is 0.41, average height difference is 2.2 μm, volume resistivity is 10 ^15.2 Ω · cm, magnetization is 68 Am ² / kg, and toner C is toner BET. Specific surface area St: 3.87, Sm + 0.7Ss * X: 4.38, Sm + 0.97S
s * X: 5.06.
Except for this, the evaluation was performed in the same manner as in Example 1.
(Comparative Example 7)
In Example 3, the developing device for evaluation in the evaluation of image fineness, background carrier adhesion evaluation, durability (charge reduction amount, resistance reduction amount) evaluation, and solid image carrier adhesion evaluation is shown in FIG. Evaluation was carried out in the same manner as in Example 3 except that the developing device without the apparatus (300) was changed and the developer for replenishment was changed to a developer containing no carrier, that is, a toner. (Comparative Example 8)
Evaluation was carried out in the same manner as in Example 3 except that the toner was changed to toner B.

Table 1 summarizes the carriers and toners used in Examples and Comparative Examples.

From Table 2, it can be seen that Examples 1 to 17 give good results in the edge effect, carrier adhesion, image definition, charge reduction amount, and resistance change amount.
The carrier obtained from Comparative Example 1 cannot obtain a sufficient film thickness and has a problem in the wear resistance of the carrier.
The carrier obtained from Comparative Example 2 cannot provide sufficient unevenness on the surface of the coat layer, has an insufficient toner spent scraping effect, and has a large charge reduction.

The carrier obtained from Comparative Example 3 has insufficient stirring of the coating solution, insufficient dispersion of particles, and insufficient unevenness on the surface of the coating layer. As a result, the scraping effect of toner spent is insufficient and the charge reduction is large. Further, since the dispersion is insufficient, the coating layer is likely to be locally scraped and the resistance is greatly reduced.
The carrier obtained from Comparative Example 4 has insufficient stirring of the coating solution, insufficient dispersion of the particles, and unevenness on the surface of the coating layer. As a result, the scraping effect of toner spent is insufficient and the charge reduction is large. In addition, the toner B is not sufficiently fixed with the hydrophobic fine powder, which causes a decrease in charge due to transfer to the carrier. Further, there are many filming on the developing roller and the photosensitive member.
In the carrier obtained from Comparative Example 5, the coating liquid is not sufficiently stirred, and the dispersion of the particles is insufficient, and the particles are present in the coating layer by forming a large agglomeration. Although the surface irregularities are large and have a scraping ability, the spent material tends to accumulate in the uneven grooves, and when the coat layer is peeled off due to stress, the core material part is exposed as a large lump.
In the carrier obtained from Comparative Example 6, the coating liquid is not sufficiently stirred, and the dispersion of the particles is insufficient, and the particles are present in the coating layer by forming large agglomerates. Although the surface irregularities are large and have a scraping ability, the spent material tends to accumulate in the uneven grooves, and when the coat layer is peeled off due to stress, the core material part is exposed as a large lump. In addition, since the hydrophobic fine powder is too firmly fixed in the toner C, the effect expected from the hydrophobic fine powder cannot be obtained sufficiently, the image density does not appear, the cleaning failure, the transfer failure, the toner scattering, the unstable charging, the development. Quality defects such as filming of toner base components on the roller and photoconductor occurred.
Since Comparative Example 7 is an image forming apparatus using a developing system that does not use a replenishing developer, the charge amount of the developer and the resistance value of the carrier are remarkably lowered after long-term use.
In Comparative Example 8, when toner B is used, the amount of hydrophobic fine powder transferred to the carrier increases compared to toner A, so the carrier charge amount decreases greatly, and both charging stability and image quality are inferior. Become.

1 is a schematic diagram illustrating a configuration of an image forming apparatus according to the present invention. FIG. 2 is a diagram illustrating a schematic configuration illustrating a structure around a developing unit of a developing device according to an embodiment of the present invention. It is a schematic block diagram of the developer supply part used by this invention. (A) is an external view which shows schematic structure of the nozzle provided in a developer supply apparatus, (b) is the axial sectional drawing, (c) is the code | symbol AA in (b). It is sectional drawing. It is sectional drawing which shows schematic structure of a screw pump. FIG. 6 is a perspective view of a state where a developer containing member is filled with a developer. FIG. 6 is a front view showing a state where the developer inside the developer containing member is discharged and reduced in volume. It is a figure which shows a powder resistance measuring apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2A, 2B, 2C, 2D Image formation unit 3 Charging unit 301 Charging roller 6 Exposure apparatus 7 Paper feed cassette 8 Transfer belt 9 Fixing apparatus 10A, 10B, 10C, 10D Developing apparatus 10a Partition member 10b Toner density sensor 11a, 11b Conveying screw 12 Developing roller 13 Doctor blade 14 Developer accommodating portion 15a Replenishment port 51 Discharging path 52 Discharging roller pair 53 Discharging tray 54 Paper adsorbing roller 55 Registration roller pair

DESCRIPTION OF SYMBOLS 100 Main body 200A, 200B, 200C, 200D Developer supply device 220 Developer supply device 221 Transport tube 222 Container holder 223 Screw pump 224 Rotor 225 Stator 226 Drive motor 227 Universal joint 230 Developer container 231 Developer storage member 232 Base Part 233 sealing material

240 Nozzle 241 Inner pipe 241a Developer flow path 242 Outer pipe 244 Air flow path 246a, 46b Air supply port 247 Developer outlet 260 Air supply means 260a, 260b Air pump 261a, 261b Air supply path 262a, 262b Open / close valve 300 Developer Discharge device 330 Recovery container 331 Discharge pipe

Claims (17)

In the developer composed of toner and carrier, the toner is obtained by externally adding hydrophobic fine powder to base particles composed of at least a colorant and a binder resin, and the toner particles after externally adding the hydrophobic fine powder The specific surface area St satisfies the following formula (1), and the carrier has a core material and a coating film covering the core material, and the coating film contains a binder resin and particles. And the ratio of the average particle diameter of the particles to the average film thickness of the coating film is 0.01 or more and 1.00 or less, and the surface has irregularities with an average height difference of 0.02 μm or more and 2.0 μm or less. An image forming developer characterized by that.
Sm + 0.7Ss * X / 100 <St <Sm + 0.97Ss * X / 100 (1)
[In the formula, Sm is the specific surface area of the base particles, Ss is the specific surface area of the hydrophobic fine powder, and X is the addition rate (% by mass) of the hydrophobic fine powder to the base particles. ] 2. The carrier according to claim 1, wherein the ratio of the particles to the sum of the weight of the binder resin and the particles in the carrier is 10% or more and 80% or less. The carrier according to claim 2, wherein the ratio of the particles to the sum of the weight of the binder resin and the particles is 40% or more and 70% or less. The ratio of the product of the cross-sectional area of the particles and the number of the particles to the product of the surface area of the core and the number of the cores is 0.3 or more and 30 or less. The carrier according to one item. 5. The carrier according to claim 1, wherein the volume resistivity is 1 × 10 ¹⁰ Ω · cm to 1 × 10 ¹⁷ Ω · cm. The carrier according to any one of claims 1 to 5, wherein the particles contain any one of alumina, silica, and titanium. The carrier according to claim 1, wherein an average film thickness of the coating film is 0.05 μm or more and 4.00 μm or less. The carrier according to claim 7, wherein an average film thickness of the coating film is 0.05 μm or more and 2.00 μm or less. The carrier according to claim 1, wherein the binder resin has a glass transition temperature of 20 ° C. or more and 100 ° C. or less. The carrier according to any one of claims 1 to 9, wherein a weight average particle diameter is 20 µm or more and 65 µm or less. The carrier according to any one of claims 1 to 10, wherein the binder resin contains a silicone resin. The carrier according to any one of claims 1 to 11, wherein the binder resin contains an acrylic resin. The electrophotographic carrier according to claim 1, wherein at least the binder resin is an acrylic resin and a silicone resin. The carrier according to any one of claims 1 to 12, wherein magnetization in a magnetic field of 1 kOe is 40 Am ² / kg or more and 90 Am ² / kg or less. To an image forming apparatus that performs development while supplying toner and carrier to the developing device and discharging excess developer in the developing device with respect to the developing device containing toner and carrier In the developer to be used, the developing device is toner and / or the toner contained in the developing device satisfies the following formula (1), and
The carrier supplied to the developing device and / or the carrier accommodated in the developing device has a core material and a coating film covering the core material, and the coating film is a binder resin. The ratio of the average particle diameter of the particles to the average film thickness of the coating film is 0.01 or more and 1 or less, and the surface has an average height difference of 0.02 μm or more and 2.0 μm or less. A developing device using a developer having the following.
Sm + 0.7Ss * X / 100 <St <Sm + 0.97Ss * X / 100 (1)
[In the formula, Sm is the specific surface area of the base particles, Ss is the specific surface area of the silica fine powder, and X is the addition ratio (mass%) of the hydrophobic fine powder to the base particles. ] An image carrier that carries an electrostatic latent image and a developing device that visualizes the electrostatic latent image on the image carrier are integrally supported, and a replenishment developer including a toner and a carrier is provided. 16. A process cartridge that is removably provided in an image forming apparatus main body that replenishes the developing device and discharges the developer from the developing device, wherein the developing device uses the developer according to claim 15. Process cartridge. An image carrier that carries an electrostatic latent image and a developing device that visualizes the electrostatic latent image on the image carrier are integrally supported, and a replenishment developer including a toner and a carrier is provided. The developer in the developing device according to claim 15, wherein the developing device is detachably attached to an image forming apparatus main body that replenishes the developing device and discharges the developer from the developing device. A process cartridge characterized by that.

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