JP2009192675A - Carrier, two-component developer comprising carrier and toner, and image forming method - Google Patents

Abstract

Provided are a carrier for a two-component developer that hardly deteriorates in image quality even after repeated use, a two-component developer comprising the carrier and a toner, and an image forming method using the same.
A carrier comprising a coating layer formed on a surface of a core material particle made of a magnetic material and coated and formed using a coating layer solution containing at least colloidal silica, a condensate of alkoxysilane having a specific structure, and a solvent. And a toner containing a colorant, a binder resin and a release agent, obtained by aqueous granulation, and having a surface release agent amount required by the FTIR-ATR method of less than 4% by mass. Combined to make a two-component developer. For example, the two-component developer is put in a developer container (42K, 42Y, 42M, 42C) of the image forming apparatus 100 to form an image by a predetermined process.
[Selection] Figure 3

Description

  The present invention relates to a carrier for developing an electrostatic latent image for a two-component developer used for image formation in an electrostatic copying process such as a copying machine, a facsimile machine, and a printer, a developer using the carrier, and an image forming method. .

2. Description of the Related Art Conventionally, in an image forming apparatus such as an electrophotographic copying apparatus, a two-component developing device that performs development using a two-component developer composed of a carrier for developing an electrostatic latent image having magnetic properties and toner, and only toner are used. There is known a one-component developing apparatus that performs development.
The two-component developing device usually includes a developing sleeve that is a cylindrical developer carrying member that includes a magnet roller including a magnet body having a plurality of magnetic poles therein and is rotatably supported. While carrying the electrostatic latent image developing carrier (two-component developer) with toner attached to the surface of the developing sleeve, the carrier is conveyed to a developing area that is opposite to the image carrier, and a magnetic material composed of the two-component developer. Development is performed with a brush.

In the two-component developing device, charging is performed by stirring and mixing the carrier for developing the electrostatic latent image and the toner, so that the charging property of the toner is stable and a relatively stable good image can be obtained.
Concerning the carrier, the toner component is prevented from spent on the carrier surface, the formation of a uniform carrier surface, the surface oxidation is prevented, the moisture sensitivity is prevented, the life of the developer is extended, the carrier is prevented from adhering to the surface of the photoreceptor, the carrier of the photoreceptor The surface of the carrier is coated for the purpose of protecting from scratches or abrasion due to erosion, controlling the charge polarity, or adjusting the amount of charge, and is usually provided with a hard, high-strength coating layer made of a suitable resin material. Has been done.
Regarding the above coating technology, for example, those coated with a specific resin material (see Patent Document 1), those in which various additives are added to the coating layer (see Patent Documents 2 to 8), and further added to the carrier surface There have been proposed one using an agent attached (see Patent Document 9), and one using a coating film containing conductive particles larger than the coating film thickness (see Patent Document 10). Patent Document 11 describes that a benzoguanamine-n-butyl alcohol-formaldehyde copolymer is used as a main component for a carrier coating material, and Patent Document 12 describes a carrier-coated cross-linked product of a melamine resin and an acrylic resin. It is described that it is used as a material.

  However, the above technology still has insufficient durability and carrier adhesion suppression, and particularly with respect to durability, the spent layer on the carrier surface of the toner, the resulting unstable charge amount, and the coating layer due to the film scraping of the coating resin In the initial stage, a good image can be obtained. However, as the number of copies increases, the image quality of the copied image deteriorates, which is a problem. .

  In particular, it has been attempted to prevent the toner spent on the carrier surface by using a resin having a low surface energy such as a silicone resin. It also reduces the adhesion to. For this reason, although toner spent on the carrier surface is suppressed, peeling of the carrier coating layer (silicone resin) from the core material particles is promoted, causing a decrease in resistance due to the core material exposure.

For the above problem, the carrier coating layer is made of an acrylic resin and a silicone resin, and the acrylic resin portion having high adhesion to the core material and the silicone resin having a low surface energy are coated so as to further cover it. A solution method using a so-called layer structure has been proposed (see Patent Document 13).
In addition, as a combination of acrylic resin and silicone resin, a method to improve chargeability, core adhesion, and spent resistance by using acrylic modified silicone resin coated carrier has been proposed. (See Patent Documents 14 and 15).
According to the above method, the effect is remarkable as compared with the conventional method, but the demand for the durability of the developer in recent years is larger than the conventional method, and further improvement is desired. In particular, even if both adhesion and prevention of spent can be achieved at the same time, the coating layer is still deteriorated due to stress during stirring of the developer. For this, further improvements are needed.

Furthermore, with respect to such a problem, by making the surface of the carrier core particle a carrier coated with a coating layer containing a metal oxide formed by a sol-gel method and an organoalkoxysilane and / or a coupling agent, A technique for improving toner filming resistance and durability has been proposed (see Patent Document 16).
As described in the examples, the coating layer in the above proposal is mainly composed of a metal oxide composed of Zn or Zr, and the strength of the film is expressed by the metal oxide.
According to the above method, the adhesion to the core material, which is the above-mentioned problem, and the film strength / spent resistance by the metal oxide are improved. It has been found that there is a problem in that the metal oxide component may cause deterioration of the spent resistance of the coating layer or cause scraping or peeling due to generation of cracks in the coating layer.

JP 58-108548 A JP 54-1555048 A JP 57-40267 A JP 58-108549 A JP 59-166968 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 JP 2006-058811 A JP-A-8-234501 JP 2000-235283 A JP 2002-196541 A

In view of the above circumstances, the object of the present invention is to improve the adhesion between the carrier coating layer and the core material particles, and without repeated filming of the toner spent or carrier coating layer even during long-term developer stirring. Also, it is to provide a carrier for a two-component developer in which image quality is hardly deteriorated. Another object of the present invention is to provide a two-component developer comprising the carrier and toner for the two-component developer and an image forming method using the two-component developer.
The toner used in the carrier for the two-component developer of the present invention is obtained by aqueous granulation and contains at least a colorant, a binder resin, and a release agent.
Hereinafter, the carrier coating layer may be expressed as “coating layer”, the core material particles as “core material”, and the carrier for two-component developer as “carrier”.

As a result of extensive studies by the present inventors in order to solve the above-mentioned problems, at least a coloring material, a binder resin, and a release agent exhibiting a predetermined exposure amount are used, and two components used together with a toner obtained by aqueous granulation In a carrier for developer (a carrier having a coating layer on the surface of at least core material particles made of a magnetic material), a coating layer solution containing a condensate of a specific content (ratio) of colloidal silica and alkoxysilane and a solvent is used. It has been found that the above-mentioned problems can be effectively achieved by coating on the surface of the core material particles and forming a carrier coating layer having a predetermined film thickness. That is, by using the carrier of the present invention, high image quality can be maintained over a long period of time, and a long-life two-component developer can be provided.
This invention is based on the said knowledge, and the said subject is solved by the invention described in the following [1]-[14]. Hereinafter, the present invention will be specifically described.

[1]: The above-described problem is a carrier for a two-component developer used together with a toner containing at least a colorant, a binder resin, and a release agent and obtained by aqueous granulation,
The amount of the release agent present in the depth region from the toner surface to 0.3 μm determined by FTIR-ATR (total reflection absorption infrared spectroscopy) is less than 4% by mass; and
The carrier has at least core particles made of a magnetic material, and a coating layer on the surface of the core material particles. The coating layer is made of at least colloidal silica and an alkoxysilane represented by the following general formula (1). It is applied and formed using a condensate and a coating layer solution containing a solvent,
The content of colloidal silica contained in the coating layer is less than 60% by mass, and the ratio (h / D _W ) between the film thickness h of the coating layer and the volume average particle diameter D _W of the carrier is 0.01. It is solved by a carrier characterized by being larger than.
Si (R ¹ ) _a (R ² ) _4-a (1)
[Wherein, R ¹ represents an alkyl group having 1 to 10 carbon atoms, R ² represents an alkoxy group having 1 to 10 carbon atoms, an alkenyloxy group, an acyloxy group, or an alkoxyalkoxy group, and a represents 0, 1, or 2 It is an integer. ]

  [2]: The carrier according to [1] above, wherein the content of colloidal silica in the coating layer is 0.5% by mass or more and 50% by mass or less.

  By setting the above range, the colloidal silica is more stably retained in the coating phase by the alkoxysilane condensate, and even when the coating phase is made into a thick film, cracks and the like are not generated, and the wear resistance is further improved. be able to.

[3]: In the carrier described in [1] or [2] above, the h / D _W is in a range of 0.025 <h / D _W <0.2.

By setting h / _DW within the above range, it is possible to balance the wear resistance and the resistance value and maintain good image forming characteristics.

[4]: The carrier according to any one of [1] to [3], wherein the carrier has a volume average particle diameter _DW of 20 to 65 μm.

By setting the volume average particle diameter _DW of the carrier in the above range, it is possible to more reliably prevent carrier adhesion (scattering) to the electrostatic latent image carrier and prevent occurrence of carrier streaks, and the like. Image formation with high image quality is possible.

  [5]: The carrier according to any one of [1] to [4] above, wherein the alkoxysilane condensate represented by the general formula (1) has a molecular weight of 1000 or less.

  By setting the molecular weight of the alkoxysilane condensate to 1000 or less, not only the viscosity is adjusted well when the coating layer solution is prepared, but also uniform coating on the surface of the core particles is facilitated. Can be held well.

  [6]: In the carrier according to any one of [1] to [5], the coating layer is applied and formed using a coating layer solution further containing an aminosilane coupling agent. It is characterized by that.

  By including the aminosilane coupling agent, the charge amount of the carrier can be controlled in a state suitable for the toner.

[7]: In the carrier according to any one of [1] to [6], the carrier is filled in a cell including an electrode 1 and an electrode 2 each having a distance between electrodes of 0.2 cm and a surface area of 2.5 cm × 4 cm. The volume resistance R obtained by the following equation (1) from the resistance value r measured by applying a DC voltage of 1000 V between both electrodes is 10 [Log (Ω · cm)] or more and 16 [Log (Ω · cm)] or less.
R = Log [r × (2.5 cm × 4 cm) ÷ 0.2 cm] (1)

  By setting the volume resistance (R) in the above range, it is possible to prevent the carrier adhesion in the non-image area well and effectively prevent the edge effect in which the image density is emphasized during development.

  [8]: The above problem comprises the carrier according to any one of [1] to [7] and a toner obtained by water-based granulation containing at least a colorant, a binder resin, and a release agent, and The amount of the release agent present in the depth region from the surface of the toner to 0.3 μm determined by FTIR-ATR (total reflection absorption infrared spectroscopy) is less than 4% by mass 2 Solved by component developers.

  [9]: In the two-component developer described in [8] above, the binder resin contained in the toner is a polyester resin.

  [10]: The two-component developer according to [8] or [9] above, wherein the binder resin contains a modified polyester having a substituent having a terminal capable of reacting with an active hydrogen group. .

  According to [9] and [10], the molecular weight can be easily controlled and modified, and it is suitable as a binder resin used in aqueous granulation, and is excellent in low-temperature fixability and glossiness after fixing, Since the compatibility with the carrier in the present invention is very good, high-quality image formation is possible even in long-term use.

  [11]: In the two-component developer according to any one of [8] to [10], the release agent is a wax, and the content of the wax with respect to the entire toner is DSC (differential scanning calorimeter). It is 1 to 20% by mass in terms of mass converted from the endothermic amount of the wax determined by the method, and the depth from the surface determined by the FTIR-ATR (total reflection absorption infrared spectroscopy) method of the wax to 0.3 μm. The amount existing in the region is 0.1% by mass or more and less than 4% by mass.

  By setting the wax content and the surface wax amount to the entire toner within the above ranges, it is possible to ensure the releasability at the time of fixing and the hot offset resistance and to maintain the spent resistance.

  [12]: The two-component developer according to any one of [8] to [11] above, wherein the toner has a volume average particle size of 3 μm or more and 8 μm or less.

  [13]: In the two-component developer according to any one of [8] to [12], the ratio of the volume average particle diameter to the number average particle diameter of the toner (volume average particle diameter / number average particle diameter) is It is 1.00 or more and 1.25 or less.

  By setting the ratio in the range [12] and [13], it is possible to prevent the carrier charging ability from being lowered during long-term agitation, and to suppress fluctuations in the toner particle diameter, thereby enabling high-resolution and high-quality image formation.

  [14]: The above-described problem is described in any one of [8] to [13], wherein the electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier and the electrostatic latent image is used. A development process for developing a two-component developer to form a visible image, a transfer process for transferring the visible image to a recording medium, and a fixing process for fixing the transferred image transferred to the recording medium. It is solved by an image forming method characterized by comprising at least.

According to the carrier of the present invention, at least on the surface of the core particles made of a magnetic material, coating / forming is performed using a coating layer solution containing a condensate of a specific content (ratio) colloidal silica, a specific alkoxysilane, and a solvent. Since the coating layer having a specific film thickness ratio is provided, the adhesion between the coating layer and the core material is improved, and the toner spent and carrier coating layer are not scraped even when the developer is stirred for a long time.
For this reason, when used together with a toner containing at least a colorant, a binder resin, and a release agent and obtained by aqueous granulation, high image quality can be maintained and a long-life two-component developer can be provided. It becomes. In particular, by using a toner containing a release agent in which the amount of the release agent existing in a depth region from the toner surface to 0.3 μm is defined, high image quality can be maintained over a long period of time.
According to the two-component developer of the present invention, a carrier having a coating layer having a specified film thickness ratio composed of a condensate of colloidal silica with a specific content (ratio) and a specific alkoxysilane, and release of the surface region By using a toner having a specified agent content (for example, a wax content) (having a predetermined amount of exposed wax), image quality can be reduced and a high image quality can be maintained over a long period of time. Lifespan can be improved.
According to the image forming method of the present invention, since the two-component developer of the present invention is used, there is no spent on the carrier surface of the toner even when the developer is stirred for a long time, the charge amount is stable, and the colloidal silica constituting the coating layer There is no film scraping of the condensate of the specific alkoxysilane, and there is no reduction in the coating layer and no accompanying resistance reduction, so that a high-quality image can be formed over a long period of time without any deterioration in the image quality of the copied image even in repeated use.

As described above, the carrier in the present invention is a carrier for a two-component developer that contains at least a colorant, a binder resin, and a release agent and is used together with a toner obtained by aqueous granulation,
The amount of the release agent present in the depth region from the toner surface to 0.3 μm determined by FTIR-ATR (total reflection absorption infrared spectroscopy) is less than 4% by mass; and
The carrier has at least core particles made of a magnetic material, and a coating layer on the surface of the core material particles. The coating layer is made of at least colloidal silica and an alkoxysilane represented by the following general formula (1). It is applied and formed using a condensate and a coating layer solution containing a solvent,
The content of colloidal silica contained in the coating layer is less than 60% by mass, and the ratio (h / D _W ) between the film thickness h of the coating layer and the volume average particle diameter D _W of the carrier is 0.01. It is characterized by being larger than.
Si (R ¹ ) _a (R ² ) _4-a (1)
[Wherein, R ¹ represents an alkyl group having 1 to 10 carbon atoms, R ² represents an alkoxy group having 1 to 10 carbon atoms, an alkenyloxy group, an acyloxy group, or an alkoxyalkoxy group, and a represents 0, 1, or 2 It is an integer. ]

In the present invention, an electrophotographic developer, that is, a carrier and a toner constituting a so-called two-component developer will be described in order.
It should be noted that those skilled in the art can easily make other embodiments by changing or correcting the present invention within the scope of the claims, and these changes and modifications are included in the scope of the claims. The following description is an example of the best mode of the present invention, and does not limit the scope of the claims.

[Career]
The carrier of the present invention comprises a coating layer comprising core particles (core material) made of a magnetic material, at least colloidal silica on the surface of the core, a condensate of alkoxysilane represented by the general formula (1), and a solvent. It consists of a carrier coating layer (coating layer) coated and formed using a liquid.
Hereinafter, a condensate of colloidal silica and a specific alkoxysilane may be expressed as a “coating layer binding material”. In addition, the coating layer binding material includes various coupling agents (for example, aminosilane coupling agents) described later that are added as necessary.
[Core]
The core material is not particularly limited and can be appropriately selected according to the purpose from those known as two-component developer carriers for electrophotography. For example, ferrite, magnetite, iron, nickel are preferable. Can be mentioned. Further, when considering adaptability to environmental aspects that have been remarkably advanced in recent years, if it is a ferrite, it is not a conventional copper-zinc ferrite, for example, Mn ferrite, Mn-Mg ferrite, Mn-Mg-Sr It is preferable to use ferrite, copper-zinc ferrite, lithium-based ferrite or the like.

For the purpose of controlling the resistance of the core material and the purpose of improving the production stability, other elements such as Li, Na, K, Ca, Ba, Y, Ti, Zr are used as the constituent elements of the core material. One or more elements such as V, Ag, Ni, Cu, Zn, Al, Sn, Sb, and Bi may be blended. As these compounding quantities, it is preferable that it is 5 atomic% or less of the total amount of metal elements, and it is more preferable that it is 3 atomic% or less.
The core material preferably has a volume average particle size (D _W ) of 20 μm or more from the viewpoint of prevention of carrier adhesion (scattering) to the electrostatic latent image carrier, and prevention of occurrence of carrier streaks, etc. The thing of 100 micrometers or less is preferable from the point of the image quality fall prevention. Particularly for higher image quality in recent years, those having a volume average particle diameter (D _W ) of 20 to 65 μm are more preferred, and those having a volume average particle diameter of 20 to 50 μm are even more preferred.
Here, the volume average particle diameter of the core material can be measured, for example, by using “Microtrac particle size analyzer SRA” manufactured by Nikkiso Co., Ltd., with a range setting of 0.7 μm to 125 μm.

(Coating layer)
The coating layer is applied and formed on the surface of the core material using a coating layer solution.
As described above, the coating layer liquid contains at least colloidal silica, a condensate of alkoxysilane represented by the general formula (1), and a solvent, and if necessary, an aminosilane coupling agent, fine particles, and other components. It contains.
The colloidal silica (i) and alkoxysilane condensate (ii) in the coating layer solution have a silanol moiety (silanol group) and are present in a state of maintaining condensation reactivity. After being applied to the surface of the material, hydrolysis is further promoted through a heating process, and a condensation reaction including reactions (i) and (ii) proceeds to finally form a strong coating layer on the carrier surface. It becomes possible to do.

<Colloidal silica>
Colloidal silica contained in the coating layer liquid is a colloidal silica particle having a diameter of 5 to 200 nm, preferably 5 to 40 nm, which is colloidally dispersed in water or an organic solvent. Dispersed colloidal silica is preferred. Colloidal silica has a silanol group on its surface and can form a chemically strongly bound coating layer by reaction with a condensate of alkoxysilane described in detail later.

  Specific examples of such colloidal silica include, for example, Snowtex O, MA-ST, IPA-ST, NBA-ST, IBA-ST, EG-ST, XBA-ST, NPC manufactured by Nissan Chemical Industries, Ltd. -ST, DMAC-ST, Catalyzed SN, OSCAL1132, OSCAL1232, OSCAL1332, OSCAL1432, OSCAL1532, OSCAL1632, OSCAL1732, etc. manufactured by Catalytic Chemical Industry Co., Ltd. are not limited thereto.

The content of colloidal silica in the coating layer is preferably less than 60% by mass. Most preferably, it is 0.5 mass% or more and 50 mass% or less.
When the content of colloidal silica is out of the above range, the effect of alkoxysilane serving as a binder for stably holding colloidal silica in the coating phase is not sufficiently exhibited. Cracks are likely to occur in the coating layer, and as a result, the wear resistance may be lowered, which is not preferable.

<Alkoxysilane as condensate>
The coating layer solution in the present invention contains a condensate of alkoxysilane represented by the general formula (1).
Specific examples of the alkoxysilane used as the condensate include, for example, tetramethoxysilane, tetraethoxysilane, tetra n-propoxysilane, tetraisopropoxysilane, tetra n-butoxysilane, tetraisobutoxysilane, and methyltrimethoxysilane. , Methyltriethoxysilane, ethyltrimethoxysilane, isobutyltrimethoxysilane and the like. These may be used alone or in combination, and may be partially hydrolyzed beforehand.
Alternatively, the above-mentioned alkoxysilane can be contained in the state of a condensate hydrolyzed using a catalyst as necessary in a solvent. When the coating layer solution is adjusted in a state where it is not hydrolyzed and this coating layer solution is coated on the surface of the carrier core material by the method described later, it becomes difficult to form a coating layer having a desired film thickness. In addition, the reaction for forming the final coating layer accompanying the heat treatment becomes insufficient, and the required wear resistance and spent resistance may be significantly deteriorated.

  A suitable solvent for the condensation reaction is that the organosiloxane condensate can be dissolved. Specific examples of such a solvent include alcohols such as methanol, ethanol, isopropanol, n-butanol, isobutanol and 3-methyl-3-methoxybutanol, acetylacetone, methyl acetoacetate, ethyl acetoacetate, propylacetoacetate, Ketones such as butyl acetoacetate, 2,4-hexane-dione, 2,4-octane-dione are suitable. These solvents are preferably used alone or in combination of two or more because it is preferable to use them in an optimum formulation as necessary in consideration of control of the reactivity of the condensation reaction product and stabilization of the product. May be. Moreover, it is also possible to add water for the purpose of accelerating the condensation reaction as necessary.

The molecular weight of the alkoxysilane condensate is preferably 1000 or less.
When the molecular weight of the alkoxysilane is 1000 or more, not only the wear resistance may be remarkably lowered, but also the viscosity of the coating layer solution is increased, and it is difficult to uniformly coat the coating layer on the core surface. May be undesirable.

<Aminosilane coupling agent>
If necessary, the coating layer solution may further contain an aminosilane coupling agent. In other words, the charge amount of the carrier with respect to the toner can be well controlled by including the aminosilane coupling agent. As the aminosilane coupling agent, for example, those represented by the structural formulas shown in Table 1 below are suitable.

  The content of the aminosilane coupling agent in the coating layer is preferably 0.001% by mass to 30% by mass, and more preferably 0.001% by mass to 10% by mass. When the content is less than 0.001% by mass, the chargeability is likely to be affected by the environment, and the product yield tends to decrease. When the content exceeds 30% by mass, the coating layer tends to be brittle, The wear resistance of the coating layer may be reduced.

<Fine particles>
As a material to be contained in the coating layer, fine particles different from those described above can be further contained. That is, if necessary, the coating layer solution further contains fine particles different from the above-described components, and the coating layer solution is applied to the surface of the carrier core material to form the coating layer with a coating thickness. By selecting an appropriate content and particle size, the film strength in the coating layer can be remarkably improved.
As such fine particles, conventionally known materials can be used singly or in combination, and representative examples include metal oxides such as silica, titanium oxide, and alumina. Among these, alumina fine particles are preferably used because the toner is negatively charged.

The content of the fine particles is appropriately selected depending on the material constituting the film formed into a film, but is preferably 70% by mass or less. This is because if it exceeds 70% by mass, detachment of fine particles from the film tends to occur, which may cause problems in durability.
The average particle diameter of the fine particles depends on the thickness of the film, but is preferably in the range of 0.01 to 0.7 μm. The particle size of the fine particles used according to the thickness of the film, for example, the metal oxide is appropriately selected.
The thickness of the film here refers to the volume of the component (the coating layer binding material) that does not contain the fine particle component among the components of the coating layer contained in the carrier for the two-component developer used for electrostatic latent image development. The value divided by the surface area of the magnetic fine powder constituting the core material.
The surface area of the magnetic powder is obtained by calculating the volume average particle diameter, which is a calculated value obtained as the surface area of the corresponding sphere, and the average particle diameter of the fine particles contained with respect to the film thickness is 0.01 to 1 times the particle diameter. A range is preferred. This is because if it is less than 0.01 times, the effect of improving the film strength by filling the particles is not recognized, and conversely if it is more than 1 times, particles are likely to be detached from the film.

Further, in order to make the electric resistance of the carrier of the present invention used for electrostatic latent image development appropriate, it is possible to contain a conductive substance in the coating material of the carrier coating layer. As the conductive material here, a known conductive material can be used.
Examples of the conductive material, for example, carbon black, conductive ZnO, metal powder such as Al, SnO ₂ doped with SnO ₂ and various elements made by various methods, borides, e.g., TiB _2, ZnB _2, MoB _2, silicon and conductive polymers carbide (polyacetylene, polyparaphenylene, poly (para - phenylene sulfide), polypyrrole), and the like.

[Method of forming coating layer]
As a method for forming the coating layer, a conventionally known method can be used, and the condensate of at least the colloidal silica and the alkoxysilane represented by the general formula (1) and a solvent are formed on the surface of the core material particles as the core material. Examples thereof include a method in which the coating layer forming liquid (coating layer liquid) is applied by means such as spraying or dipping.
Furthermore, it is preferable to promote the condensation reaction of the coating layer by heating the carrier particles coated and formed with the coating device selected from the above means. This heat treatment may be performed subsequently in the coating apparatus after the coating layer is formed, or may be performed by another heating means such as a normal electric furnace or firing kiln after the coating layer is formed.
The heat treatment temperature varies depending on the constituent material of the coating layer to be used, that is, the coating layer binding material mainly composed of colloidal silica (i) and alkoxysilane condensate (ii), and therefore is generally determined. Although it is not a thing, about 120-350 degreeC is preferable, The temperature below the decomposition temperature of a coating layer binder material is especially preferable, It is more preferable that it is an upper limit temperature to about 220 degreeC, As heat processing time, It is preferably about 120 minutes.

[Physical properties of the carrier]
The content of the coating layer in the carrier is preferably 5% by mass or more, and more preferably 5% by mass or more and 10% by mass or less.
Further, the ratio (h / D _W ) between the film thickness h of the coating layer and the volume average particle diameter D _W of the carrier is preferably larger than 0.01, and 0.025 <h / D _W <0. 2 is more preferable, and 0.025 <h / D _W <0.1 is more preferable.
For example, when the content of colloidal silica in the coating layer is less than 0.5% by mass (particularly less than 5% by mass) or h / D _W is 0.025 or less, the strength of the coating layer is It is not sufficient, and not only the peeling and wear may partially progress and the core particles may be exposed easily, but it is also difficult to uniformly coat the core particles at the coating liquid coating stage. There is a case. In addition, when the content of colloidal silica in the coating layer exceeds 50% by mass (particularly, more than 10% by mass) or h / _DW is 0.2 or more, the strength of the coating layer is improved and wear resistance is increased. Although it is excellent in properties, it may be difficult to obtain a carrier having a desired resistance value, and as a result, image quality may deteriorate.

Here, the film thickness (thickness) h of the coating layer is, for example, 50 points using a transmission electron microscope (TEM) and a scanning transmission electron microscope (STEM) after creating a carrier cross section with FIB (focused ion beam). The above carrier cross section can be observed and calculated as the average value of the obtained film thickness.
In addition, the method for measuring the volume average particle diameter D _W of the carrier is not particularly limited as long as it is a device capable of measuring the particle size distribution, and can be appropriately selected according to the purpose. Model HRA9320-X100).
The volume average particle diameter _DW of the carrier is preferably 20 to 65 μm, and more preferably 20 to 50 μm. When the volume average particle size is less than 20 μm, carrier adhesion may occur due to the decrease in the uniformity of the core material particles. When the volume average particle size exceeds 65 μm, the reproducibility of image details may occur. It is bad and a fine image may not be obtained.

Further, the volume resistance (R) of the carrier is preferably 10 [Log (Ω · cm)] or more and 16 [Log (Ω · cm)] or less, and 11 [Log (Ω · cm)] or more and 15 [Log (Ω · cm)]. cm)] is more preferred.
When the volume resistance (R) is less than 11 [Log (Ω · cm)], carrier adhesion may occur in the non-image area. When the volume resistance (R) exceeds 15 [Log (Ω · cm)], an edge is generated during development. A so-called edge effect is emphasized in which the image density in the area is emphasized. The volume resistance (R) can be adjusted as necessary within the range of the volume resistance by adjusting the thickness of the coating layer and the content of the contained fine particles (conductive fine particles).

Here, as a measuring method of the volume resistance, as shown in FIG. 1, a cell 3 composed of a fluororesin container containing an electrode 1 and an electrode 2 having a distance between electrodes of 0.2 cm and a surface area of 2.5 cm × 4 cm is used. The carrier 4 is filled, and the tapping is performed under the conditions of a drop height of 1 cm, a tapping speed of 30 times / min, and a tapping frequency of 10 times. Next, a DC voltage of 1000 V was applied between both electrodes, and the resistance value after 30 seconds was measured with a high resistance meter 4329A (manufactured by Yokogawa Hewlett-Packard Co., Ltd., High Resistance Meter). The volume resistance R [Log (Ω · cm)] can be calculated by the following equation (1).
R = Log [r × (2.5 cm × 4 cm) ÷ 0.2 cm] (1)

[toner]
In the present invention, the toner for a two-component developer used together with the above-described carrier is produced in an aqueous medium, obtained by so-called aqueous granulation, and contains at least a colorant, a binder resin, and a release agent. A polyester resin is preferably used as the binder resin.
The method for producing the toner used in the present invention is not particularly limited as long as it is a method produced in an aqueous medium, and can be appropriately selected according to the purpose.
Among these, for example, a toner solution containing an active hydrogen group-containing compound and a polymer that can react with the active hydrogen group-containing compound (for example, a reactive modified polyester) is dissolved or dispersed in an organic solvent to form a toner solution. Then, the toner solution is emulsified or dispersed in an aqueous medium to prepare a dispersion, and then the active hydrogen group-containing compound and a polymer capable of reacting with the active hydrogen group-containing compound in the aqueous medium are prepared. It is preferable to apply a toner production method in which an adhesive substrate is produced in the form of particles by the reaction, and then the organic solvent is removed. The toner obtained by such a production method is preferable because of high resin selectivity, high low-temperature fixability, excellent granulation properties, and easy control of particle size, particle size distribution, and shape. .

  Examples of the toner material in the present invention include an adhesive base material (binder resin) obtained by reacting an active hydrogen group-containing compound and a polymer capable of reacting with the active hydrogen group-containing compound, a colorant, and a release agent. It contains at least an agent, and further contains other components such as a charge control agent and resin fine particles as necessary. Hereinafter, these toner materials will be described.

<Binder resin>
As the binder resin, a polyester resin having sufficient flexibility even when the molecular weight is lowered is preferable in that it can melt sharply at the time of fixing and smooth the image surface. May be used in combination. Such a polyester resin is a reaction between one or more polyols represented by the following general formula (2) and one or more polycarboxylic acids represented by the following general formula (3). Is obtained.
A- (OH) m (2)
[In Formula (2), A represents the C1-C20 alkyl group, the alkylene group, and the aromatic group or heterocyclic aromatic group which may have a substituent. m represents an integer of 2 to 4. ]
B- (COOH) n (3)
[In Formula (3), B represents the C1-C20 alkyl group, the alkylene group, the aromatic group which may have a substituent, or a heterocyclic aromatic group. n represents an integer of 2 to 4. ]

  Specific polyols represented by the general formula (2) include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, sorbitol, 1,2, 3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methyl Propanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, bisphenol A, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide addition Products, hydrogenated bisphenol A, hydrogenated bisphenol A ethylene oxide adduct, hydrogenated bisphenol A propylene oxide adduct, and the like.

  Specific polycarboxylic acids represented by the general formula (3) include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, and sebacic acid. Azelaic acid, malonic acid, n-dodecenyl succinic acid, isooctyl succinic acid, isododecenyl succinic acid, n-dodecyl succinic acid, isododecyl succinic acid, n-octenyl succinic acid, n-octyl succinic acid, isooctenyl succinic acid, Isooctyl succinic acid, 1,2,4-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5 -Hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxyprop 1,2,4-cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, emporic trimer acid, cyclohexanedicarboxylic acid, cyclohexenedicarboxylic acid, Examples include butanetetracarboxylic acid, diphenylsulfonetetracarboxylic acid, and ethylene glycol bis (trimellitic acid).

<Modified polyester capable of reacting with active hydrogen group-containing compounds>
Furthermore, the binder resin used in the present invention may contain a modified polyester capable of reacting with an active hydrogen group-containing compound. The active hydrogen group-containing compound acts as an elongation agent, a crosslinking agent, or the like when the polyester capable of reacting with the active hydrogen group-containing compound undergoes an elongation reaction or a crosslinking reaction in the granulation process in an 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 according to the purpose. For example, when the modified polyester capable of reacting with the active hydrogen group-containing compound is an isocyanate group-containing modified polyester (A), the isocyanate group-containing modified polyester (A) is reacted with a high molecular weight by a reaction such as an extension reaction or a crosslinking reaction. The amines (B) are preferred in that

  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, alcoholic hydroxyl groups are particularly preferable.

  The amines (B) are not particularly limited and may be appropriately selected depending on the intended purpose. For example, diamines (B1), trivalent or higher polyamines (B2), amino alcohols (B3), amino mercaptans ( And B4), amino acid (B5), and those obtained by blocking the amino group 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) is 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, and the like between the active hydrogen group-containing compound and the modified polyester capable of reacting with the active hydrogen group-containing compound.
The use of a 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 obtained by blocking these (ketimine compounds).

  As a mixing ratio of the amines (B) and the isocyanate group-containing modified polyester (A), an isocyanate group [NCO] in the isocyanate group-containing modified polyester (A) and an amino group in the amines (B) are used. The mixing equivalent ratio of [NHx] ([NCO] / [NHx]) is preferably 1/3 to 3/1, more preferably 1/2 to 2/1, It is particularly preferable that the ratio is ˜1.5 / 1. When the mixing equivalent ratio ([NCO] / [NHx]) is less than 1/3, the low-temperature fixability may be deteriorated. When the mixing equivalent ratio exceeds 3/1, the molecular weight of the modified polyester becomes low, and hot resistance Offset property may deteriorate.

  The site capable of reacting with the active hydrogen group-containing compound in the modified polyester that can react with the active hydrogen group-containing compound (hereinafter sometimes referred to as “polyester prepolymer”) is not particularly limited and may be a known substituent or the like. Among them, an isocyanate group, an epoxy group, a carboxylic acid, an acid chloride group, and the like can be mentioned. These may be contained singly or in combination of two or more. Among these, an isocyanate group is particularly preferable.

Among the modified polyesters, 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 fixing heating medium. It is particularly preferable that it is a urea bond-forming group-containing polyester resin (RMPE) in that it can be secured.
As a urea bond production | generation group, an isocyanate group etc. are mentioned, for example. When the urea bond generating group in the urea bond generating group-containing polyester resin (RMPE) is the isocyanate group, examples of the polyester resin (RMPE) include the isocyanate group-containing polyester prepolymer (A).

  There is no restriction | limiting in particular as frame | skeleton of the said isocyanate group containing polyester prepolymer (A), According to the objective, it can select suitably, For example, it is a polycondensate of a polyol (PO) and polycarboxylic acid (PC). A product obtained by reacting a certain active hydrogen group-containing polyester with polyisocyanate (PIC), a polycondensate of the polyol (PO) and the polycarboxylic acid (PC), and a cyclic ester are subjected to ring-opening addition polymerization and active hydrogen groups. Examples of the polyester include a polyester obtained by reacting with polyisocyanate (PIC).

  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 A mixture with (TO), etc. are mentioned. 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 (TO) 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, and polytetramethylene ether glycol. 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, and 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.

As the trivalent or higher polyol (TO), those having 3 to 8 or higher valences are preferable. 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: TO) of the diol (DIO) and the trivalent or higher polyol (TO) in the mixture of the diol (DIO) and the trivalent or higher polyol (TO) 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 (TC), dicarboxylic acid (DIC) ) And a tricarboxylic or higher 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 (TC) 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, sebacic acid, and the like.
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 (TO) is preferably 3 to 8 or higher, and examples thereof include aromatic polycarboxylic acids.
As said aromatic polycarboxylic acid, a C9-C20 thing is preferable, For example, trimellitic acid, pyromellitic acid, etc. are mentioned.
The polycarboxylic acid (PC) is selected from the dicarboxylic acid (DIC), the trivalent or higher polycarboxylic acid (TC), and a mixture of the dicarboxylic acid (DIC) and the trivalent or higher polycarboxylic acid. Any of the acid anhydrides or lower alkyl ester compounds can also be used.
Examples of the lower alkyl ester include methyl ester, ethyl ester, isopropyl ester and the like.

  Mixing mass ratio (DIC: TC) of the dicarboxylic acid (DIC) and the trivalent or higher polycarboxylic acid (TC) in the mixture of the dicarboxylic acid (DIC) and the trivalent or higher polycarboxylic acid (TC) As 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. Examples thereof include a hydroxyl group in the polyol (PO). The equivalent ratio ([OH] / [COOH]) between [OH] and the carboxyl group [COOH] in the polycarboxylic acid (PC) is usually preferably 2/1 to 1/1. It is more preferably 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. In some cases, the low-temperature fixability may deteriorate.

  The polyisocyanate (PIC) is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic diisocyanates, araliphatic diisocyanates, and isocyanurates. And those blocked with phenol derivatives, oximes, caprolactams, and the like.

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.
The cyclic ester is not particularly limited as long as it produces a polyester by ring-opening addition polymerization, but L-lactide, D-lactide, DL-lactide, racemic lactide, glycoside, γ -Butyrolactone, δ-valerolactone and ε-caprolactone.
These can be used alone or in combination of two or more.

  As a mixing ratio when the polyisocyanate (PIC) and the active hydrogen group-containing polyester resin (for example, a hydroxyl group-containing polyester resin) are reacted, an isocyanate group [NCO] in the polyisocyanate (PIC) and a hydroxyl group-containing polyester resin are used. In general, the mixing equivalent ratio ([NCO] / [OH]) with the hydroxyl group [OH] is preferably 5/1 to 1/1, more preferably 4/1 to 1.2 / 1. 3/1 to 1.5 / 1 is particularly preferred. 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 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 preferable. 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. Fixability may deteriorate.

  As an average number of the isocyanate groups contained per molecule of the isocyanate group-containing polyester prepolymer (A), 1 or more is preferable, 1.2 to 5 is more preferable, and 1.5 to 4 is more preferable. When the average number of 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 3,000 to 40,000 in terms of molecular weight distribution by GPC (gel permeation chromatography) soluble in tetrahydrofuran (THF). Preferably, 4,000 to 30,000 is more preferable. When the weight average molecular weight (Mw) is less than 3,000, the heat resistant storage stability may be deteriorated. When the Mw exceeds 40,000, 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 per minute, 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 weights made by Toyo Soda Kogyo Co., Ltd. are 6 × 10 ² , 2.1 × 10 ² , 4 × 10 ² , 1.75 × 10 ⁴ , 1.1 × 10 ⁵ , 3.9 × 10 ⁵ , 8.6 It is preferable to use those of × 10 ⁵ , 2 × 10 ⁶ , and 4.48 × 10 ⁶ and use at least about 10 standard polystyrene samples. As the detector, an RI (refractive index) detector can be used.

<Colorant>
The colorant is not particularly limited and may be appropriately selected from known dyes and pigments according to the purpose. Specific examples include, 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, Red Sand, Red Zhu , Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Perm Tread 4R, Para Red, Faise Red, Parachlor Ortho Nitroaniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carnmin 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, Pigment 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, Thio Ndigo Maroon, Oil Red, 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, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc Green, chromium oxide, pyridian, emerald green, pigment green B, naphthol green B, grease Enum gold, acid green lake, malachite green lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc white, litbon and the like. 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 preferably 1% by mass to 15% by mass, and more preferably 3% by mass to 10% by mass.

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

<Release agent>
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 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.

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.
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 to 160 degreeC is preferable, 50 to 120 degreeC is more preferable, and 60 to 90 degreeC is still more preferable. . If the melting point is less than 40 ° C., the wax may adversely affect the heat resistant storage stability, and if it exceeds 160 ° C., a cold offset may easily occur during fixing at a low temperature.
Further, the melt viscosity of the release agent is preferably 5 cps to 1,000 cps, more preferably 10 cps to 100 cps, as measured 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 1,000 cps, the effect of improving hot offset resistance and low-temperature fixability may not be obtained.

In the present invention, the content of the release agent (wax) of the toner is a value obtained by converting the endothermic amount of wax determined by a DSC (Differential Scanning Calorimetry) method into mass, and is 1 to 20 mass based on the total toner. % Is preferred.
Further, the amount (abundance) of the release agent (wax) present in the depth region from the surface to 0.3 μm, which is obtained by FTIR-ATR (total reflection absorption infrared spectroscopy) method, is less than 4% by mass. It is more preferable that the content is 0.1% by mass or more and less than 4% by mass.

The content of the release agent (wax) (total amount of wax) is determined by a ratio measurement method. The method for obtaining the total amount of wax by the ratio measuring method will be described in detail below.
The total amount of wax in the toner particles is obtained by a DSC (Differential Scanning Calorimeter) method. Each of the toner sample and the single wax sample is measured by the following measuring apparatus and conditions, and the total amount of wax is obtained from the ratio of the endothermic amounts of the obtained waxes.
・ Measurement device: DSC device (DSC60; manufactured by Shimadzu Corporation)
-Sample amount: about 5mg
-Temperature rising temperature: 10 ° C / min
Measurement range: room temperature to 150 ° C
Measurement environment: The total amount of wax in the nitrogen gas atmosphere was calculated by the following formula (2).
Total amount of wax (% by mass) = [[Endothermic amount of wax of toner sample (J / g)] × 100 / [Endothermic amount of single wax (J / g)]] Equation (2)

  According to the above analysis, the total amount of the release agent (wax) in the toner particles can be effectively defined even when the wax flows out during the toner manufacturing process and all of the charged wax is not contained in the toner.

  A method for obtaining the amount of the release agent (wax) present in the depth region of the surface will be described in detail below. The amount of the surface release agent (wax) of the toner particles can be obtained by FTIR-ATR (total reflection absorption infrared spectroscopy) method. The analysis depth is about 0.3 μm from the measurement principle, and the amount of the release agent (wax) in the depth region of 0.3 μm from the surface of the toner particles can be obtained by this analysis. The measuring method is as follows.

First, 3 g of toner is pressed for 1 minute under a load of 6 t with an automatic pellet molding machine (Type M No. 50 BRP-E; manufactured by MAEKAWA TESTING MACHINE CO.) To produce 40 mmφ (about 2 mm thick) pellets. A sample is used. The toner pellet surface is measured by the FTIR-ATR method.
The micro FTIR apparatus used was a Perscope ELMER Spectrum One with a MultiScope FTIR unit installed, and measurement was performed with a micro ATR of germanium (Ge) crystal having a diameter of 100 μm. Measurement was performed with an infrared incident angle of 41.5 °, a resolution of 4 cm ⁻¹ , and a total of 20 times.

The intensity ratio between the peak derived from the obtained release agent (wax) and the peak derived from the binder resin (binder resin) (828 cm ⁻¹ ) was defined as the relative amount of the release agent (wax) on the surface of the toner particles. . The average value after measuring four times by changing the measurement location was used. The amount of the surface release agent (wax) in the sample was calculated from the relationship with the relative release agent (wax) amount of the sample for the calibration curve in which the known release agent (wax) amount was uniformly dispersed.

From the analysis results of various toners, the value of the total amount of the release agent (wax) obtained by the DSC method and the value of the intensity ratio obtained by the FTIR-ATR method are dispersed states due to differences in the toner production process, etc. Different correlations were seen depending on the difference.
The toner containing at least a colorant, a binder resin (for example, polyester) and a release agent (for example, wax) produced in an aqueous medium, which is a preferred embodiment of the present invention, has the wax on the outermost surface of the toner particles. It was uniformly dispersed in the particles without being present, and the above correlation was examined by changing the total amount of wax of the toner and found the following.
That is, in the region where the total amount of wax is small, the amount of wax in the vicinity of the toner particle surface indicated by the strength ratio value is constant at 0, and after the total amount of wax exceeds a certain value, the value of the strength ratio increases. It is done. This confirms that the wax in the toner particles is not selectively dispersed in the vicinity of the surface, but is uniformly dispersed in a region inside the outermost surface of the toner particles. In addition, since the wax existing in a depth region of 0.3 μm from the toner particle surface analyzed by the FTIR-ATR method is in a position where it can easily ooze out on the toner surface, it effectively exhibits toner releasability. It is.

As described above, the surface wax amount of the toner particles obtained by the FTIR-ATR method is more preferably less than 4% by mass, and further preferably 0.1% by mass or more and less than 4% by mass.
If the surface wax amount is less than 0.1% by mass, the amount of wax in the vicinity of the surface of the toner particles is small, so that sufficient releasability cannot be obtained during fixing. Further, when the surface wax amount is 4% by mass or more, the amount of wax near the surface of the toner particles increases and is easily exposed on the outermost surface of the toner particles, and the toner particles easily adhere to the carrier surface via the wax. Adhesion increases and the spent resistance of the developer is deteriorated, which is not preferable. As described above, in order to improve the compatibility between the hot offset resistance during fixing and the chargeability, developability, spent resistance, etc., the above range is preferable, but the surface wax amount is particularly preferably 0. It is good that it is in the range of not less than 1% by mass and not less than 3% by mass.
Further, as described above, the total amount of the release agent (wax) determined by the DSC method is preferably 0.5 to 20% by mass, more preferably 1 to 20% by mass in the toner particles.
If the total amount of the release agent (wax) is less than 0.5% by mass, the amount of wax contained in the toner particles is too small, and sufficient release property cannot be obtained at the time of fixing, resulting in reduced hot offset resistance. There are things to do. On the other hand, when the total amount of the release agent (wax) exceeds 20% by mass, the spent resistance is deteriorated and the glossiness after fixing is lost in a color image.

  It is preferable that the release agent (wax) dispersed particles are uniformly dispersed in the toner particles. Here, uniformly dispersing means that a plurality of wax dispersed particles are dispersed in the toner particles without a large uneven distribution. For example, in an arbitrary toner cross section including the toner center, the radius connecting the arbitrary point on the toner outer periphery and the toner center is located at a length of 2/3 of the radius from the toner center toward the toner outer periphery. It is preferable that the wax dispersed particles in the inner region of the circumference be larger than 30% by number and less than 60% by number with respect to all the wax dispersed particles on the toner cross section. The exposed area of the wax on the outermost surface of the toner particles is preferably 5% or less of the surface area of the outermost surface of the toner particles.

  There is no restriction | limiting in particular as a volume average particle diameter of the said mold release agent (wax) dispersion particle, Although it can select suitably according to the objective, It is preferable that it is very small, for example, 0.1-2 micrometers is preferable. 0.1 to 1 μm is more preferable. If the volume average particle size of the dispersed particles of the wax is less than 0.1 μm, sufficient release performance may not be obtained. If it exceeds 2 μm, the uniform dispersibility of the wax in the toner may deteriorate. .

<Charge control agent>
The charge control agent is not particularly limited, and a positive or negative charge control agent can be appropriately selected and used depending on whether the charge charged on the photoconductor is positive or negative.
As the negative charge control agent, for example, a resin or compound having an electron donating functional group, an azo dye, a metal complex of an organic acid, or the like can be used. Specifically, Bontron (product numbers: S-31, S-32, S-34, S-36, S-37, S-39, S-40, S-44, E-81, E-82, E -84, E-86, E-88, A, 1-A, 2-A, 3-A) (all manufactured by Orient Chemical Co., Ltd.); Kaya Charge (Part Nos .: N-1, N-2) Kaya set black (product number: T-2, 004) (all manufactured by Nippon Kayaku Co., Ltd.); Eisenspiron black (T-37, T-77, T-95, TRH, TNS-2) (all Also manufactured by Hodogaya Chemical Co., Ltd.); FCA-1001-N, FCA-1001-NB, FCA-1001-NZ (all manufactured by Fujikura Kasei Co., Ltd.) and the like.

As the positive charge control agent, for example, a basic compound such as a nigrosine dye, a cationic compound such as a quaternary ammonium salt, a metal salt of a higher fatty acid, or the like can be used. Specifically, Bontron (part numbers: N-01, N-02, N-03, N-04, N-05, N-07, N-09, N-10, N-11, N-13, P -51, P-52, AFP-B) (all manufactured by Orient Chemical Co., Ltd.); TP-302, TP-415, TP-4040 (all manufactured by Hodogaya Chemical Co., Ltd.); Copy Blue PR , Copy charge (part numbers: PX-VP-435, NX-VP-434) (both manufactured by Hoechst); FCA (part numbers: 201, 201-B-1, 201-B-2, 201-B-3) 201-PB, 201-PZ, 301) (all manufactured by Fujikura Kasei Co., Ltd.); PLZ (product numbers: 1001, 2001, 6001, 7001) (all manufactured by Shikoku Kasei Kogyo Co., Ltd.).
The charge control agent may be used alone or in combination of two or more.

  The addition amount of the charge control agent is determined by the toner production method including the type of the binder resin and the dispersion method, and is not limited to a specific one. 0.1-10 mass parts is preferable with respect to it, and 0.2-5 mass parts is more preferable. If the addition amount exceeds 10 parts by mass, the chargeability of the toner is too high, the effect of the charge control agent is reduced, the electrostatic attraction with the developing roller is increased, the developer fluidity is reduced, the image When the concentration is less than 0.1 part by mass, the charge rise property and the charge amount are not sufficient, and the toner image may be easily affected.

[Toner Production Method]
A preferred method for producing a toner obtained by aqueous granulation for a two-component developer used together with a carrier in the present invention is to use a solution or dispersion of a toner material comprising at least a colorant, a binder resin and a release agent as an aqueous medium. The toner is emulsified or dispersed therein to prepare an emulsified liquid or dispersion, and then the toner is granulated (aqueous granulation). For example, the process includes the following steps [1] to [6].

Step [1]: Preparation of toner material solution or dispersion The toner material solution or dispersion is obtained by dissolving or dispersing a toner material such as a colorant, a binder resin, and a release agent in an organic solvent. Prepared.
The toner material is not particularly limited as long as the toner can be formed, and can be appropriately selected according to the purpose. For example, the polyester resin, the colorant, the release agent, and, if necessary, active It contains at least a hydrogen group-containing compound and a modified polyester (prepolymer) that can react with the active hydrogen group-containing compound, and other components such as a charge control agent can be selected as necessary. The organic solvent is removed during or after the toner granulation.

The organic solvent is not particularly limited as long as it is a solvent capable of dissolving or dispersing the toner material, and can be appropriately selected according to the purpose. For example, volatile compounds having a boiling point of less than 150 ° C. are preferable from the viewpoint of easy removal. For example, toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane , Trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, and the like. An ester solvent is 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 usage-amount of an 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 more. 80 to 120 parts by mass are more preferable.

  In the toner material, components other than the polymer (prepolymer) capable of reacting with the active hydrogen group-containing compound may be added and mixed in the aqueous medium in the preparation of the aqueous medium described later. Alternatively, when the solution or dispersion of the toner material is added to the aqueous medium, it may be added to the aqueous medium together with the solution or dispersion.

Step [2]: Preparation of 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, water is particularly preferable.
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 aqueous medium can be prepared, for example, by dispersing resin fine particles in the aqueous medium. The amount of resin fine particles added to the aqueous medium is not particularly limited and may be appropriately selected depending on the intended purpose. For example, 0.5 to 10% by mass is preferable.

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 resin. , Etc.
These may be used individually by 1 type and may use 2 or more types together. Among these, it is preferable that it is 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 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.

Moreover, 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. 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 resin fine particles. Examples of suitable methods for preparing an aqueous dispersion of resin fine particles include the methods shown in the following (i) to (viii).
(I) In the case of the vinyl resin, aqueous dispersion of resin fine particles directly by a polymerization reaction selected from a suspension polymerization method, an emulsion polymerization method, a seed polymerization method and a dispersion polymerization method using a vinyl monomer as a starting material. A method for producing the liquid,
(Ii) In the case of polyaddition or condensation resin such as polyester resin, polyurethane resin, epoxy resin, etc., a precursor (monomer, oligomer, etc.) or a solvent solution thereof is dispersed in an aqueous medium in the presence of an appropriate dispersant. A method of producing an aqueous dispersion of resin fine particles by heating, or curing by adding a curing agent,
(Iii) In the case of polyaddition or condensation resin such as polyester resin, polyurethane resin, epoxy resin, etc., a precursor (monomer, oligomer, etc.) or a solvent solution thereof (preferably liquid, may be liquefied by heating. ) A suitable emulsifier is dissolved therein, and then water is added to perform phase inversion emulsification.
(Iv) 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, condensation polymerization, etc.) A method of dispersing resin particles in water in the presence of an appropriate dispersant,
(V) A resin solution in which a resin prepared in advance by a polymerization reaction (any polymerization reaction mode such as addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) is dissolved in a solvent is sprayed in a mist form. A method of dispersing resin fine particles in water in the presence of a suitable dispersant after obtaining resin fine particles by
(Vi) A poor solvent is added to a resin solution in which a resin prepared in advance by a polymerization reaction (any polymerization reaction mode such as addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) is dissolved in a solvent. Or by precipitating resin fine particles by cooling a resin solution heated and dissolved in advance in a solvent, and then removing the solvent to obtain resin particles. Then, the resin particles are placed in water in the presence of a suitable dispersant. How to distribute,
(Vii) A resin solution prepared by previously dissolving a resin prepared in a polymerization reaction (any polymerization reaction mode such as addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) in a solvent is appropriately dispersed. A method of removing the solvent by heating or decompression after being dispersed in an aqueous medium in the presence of an agent,
(Viii) A suitable emulsifier in a resin solution in which a resin prepared in advance by a polymerization reaction (any polymerization reaction mode such as addition polymerization, ring-opening polymerization, polyaddition, addition condensation, condensation polymerization, etc.) is dissolved in a solvent. A method of phase inversion emulsification after adding water

  In addition, in the aqueous medium, if necessary, from the viewpoint of stabilizing the oil droplets of the solution or dispersion at the time of emulsification or dispersion described later, and sharpening the particle size distribution while obtaining a desired shape, It is preferable to use a dispersant. There is no restriction | limiting in particular as a dispersing agent, According to the objective, it can select suitably, For example, surfactant, a poorly 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 (carbon number 6 -11) Oxy] -1-alkyl (carbon number 3-4) sodium sulfonate, 3- [omega-fluoroalkanoyl (carbon number 6-8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-20) carboxylic acid or metal salt thereof, perfluoroalkylcarboxylic acid (C7-13) or metal salt thereof, perfluoroalkyl (C4-12) sulfonic acid or metal salt thereof, perfluoro Octanesulfonic acid diethanolamide, N-propyl-N- (2 Hydroxyethyl) perfluorooctanesulfonamide, perfluoroalkyl (carbon number 6-10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (carbon number 6-10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (carbon (Equation 6-16) Ethyl phosphate ester etc. are mentioned.

  Examples of commercially available surfactants having a fluoroalkyl group include Surflon S-111, S-112, S-113 (manufactured by Asahi Glass Co., Ltd.); Fluorard FC-93, FC-95, FC-98, FC- 129 (manufactured by Sumitomo 3M); Unidyne DS-101, DS-102 (manufactured by Daikin Industries); Megafac F-110, F-120, F-113, F-191, F-812, F-833 (large) Nihon Ink Co., Ltd.); Xtop EF-102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products); Manufactured) 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, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, imidazolines, and the like.
Examples of the quaternary ammonium salt type cationic surfactant include alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, pyridinium salts, alkylisoquinolinium salts, 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 (manufactured by Asahi Glass Co., Ltd.); Florard FC-135 (manufactured by Sumitomo 3M); Unidyne DS-202 (manufactured by Daikin Industries Ltd.), MegaFuck F-150 F-824 (manufactured by Dainippon Ink Co., Ltd.); Xtop EF-132 (manufactured by Tochem Products); Footgent F-300 (manufactured by Neos).

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 such as 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.
Further, when a modified polyester (prepolymer) capable of reacting with an active hydrogen group-containing compound is included as a binder resin in the solution or dispersion, the aqueous medium contains, for example, dibutyltin laurate, dioctyltin laurate. A catalyst in the reaction such as a rate can also be used.

Step [3]: Emulsification or Dispersion When the solution or dispersion containing the toner material is emulsified or dispersed in the aqueous medium, the solution or dispersion containing the toner material is dispersed in the aqueous medium while stirring. Is preferred. The dispersion method is not particularly limited, but a batch type emulsifier such as a homogenizer (manufactured by IKA), polytron (manufactured by Kinematica), TK auto homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), Ebara Mile Dar (manufactured by Aihara Seisakusho Co., Ltd.), TK Fillmix, TK Pipeline Homomixer (manufactured by Koki Kogyo Kogyo Co., Ltd.), colloid mill (manufactured by Shinko Pantech Co., Ltd.), Thrasher, Trigonal Wet Fine Crusher (Mitsui Miike Kako Co., Ltd. ), Captron (manufactured by Eurotech), continuous emulsifier such as fine flow mill (manufactured by Taiheiyo Kiko), microfluidizer (manufactured by Mizuho Kogyo), nanomizer (manufactured by Nanomizer), APV Gaurin (manufactured by Gaurin) High-pressure emulsifiers such as membrane emulsifiers such as membrane emulsifiers (manufactured by Chilling Industries Co., Ltd.) Reduction machine, an ultrasonic emulsifier such as an ultrasonic homogenizer (manufactured by Branson Co., Ltd.). Among these, it is preferable to use APV Gaurin, homogenizer, TK auto homomixer, Ebara milder, TK fill mix, and TK pipeline homomixer from the viewpoint of uniform particle size.

  In the case where a modified polyester (prepolymer) capable of reacting with an active hydrogen group-containing compound is included as the binder resin contained in the solution or dispersion, the reaction proceeds during emulsification or dispersion. The reaction conditions are not particularly limited and can be appropriately selected according to 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 10 minutes to 40 hours is preferable, and 2 hours to 24 hours is more preferable.

Step [4]: Removal of Solvent Next, the organic solvent is removed from the emulsified slurry obtained by the emulsification or dispersion. The organic solvent is removed by (1) a method in which the temperature of the entire reaction system is gradually raised to completely evaporate and remove the organic solvent in the oil droplets, and (2) the emulsion dispersion is sprayed in a dry atmosphere, Examples thereof include a method in which the water-insoluble organic solvent in the droplets is completely removed to form toner fine particles, and the aqueous dispersant is removed by evaporation.

Step [5]: Washing, drying classification, etc. When the organic solvent is removed in Step [4], toner particles are formed. The toner particles can be washed, dried, etc., and then classified as desired.
Classification can be performed, for example, by removing fine particle portions in a liquid by a cyclone, a decanter, centrifugation, or the like, and the classification operation may be performed after obtaining a powder after drying. When a dispersion stabilizer that is soluble in acid / alkali such as calcium phosphate is used in the aqueous medium, the dispersion stabilizer is dissolved with an acid such as hydrochloric acid and washed with water. Can be removed.

Step [6]: External addition of charge control agent / release agent, etc. The toner particles obtained through each of the above-described steps are released from a release agent, which is inorganic fine particles such as silica fine particles and titanium oxide fine particles, and charged as necessary. By mixing with particles such as a control agent or applying a mechanical impact force, it is possible to prevent the particles such as the release agent from detaching from the surface of the toner particles.
Examples of the method of applying the mechanical impact force include a method of applying an impact force to the mixture by a blade rotating at a high speed, an appropriate collision between particles or composite particles by introducing the mixture into a high-speed air stream and accelerating the mixture. The method of making it collide with a board is mentioned. As an apparatus used for this method, for example, an ong mill (manufactured by Hosokawa Micron Co., Ltd.), an I-type mill (manufactured by Nippon Pneumatic Co., Ltd.) and a pulverization air pressure is lowered, and a hybridization system (Nara Machinery Co., Ltd.) Product), kryptron system (manufactured by Kawasaki Heavy Industries, Ltd.), automatic mortar and the like.

[Physical properties of toner]
The shape, size, etc. of the toner is not particularly limited and can be appropriately selected according to the purpose. It is preferable to have a ratio (volume average particle diameter / number average particle diameter) to the average particle diameter.

The average circularity is a value obtained by dividing the perimeter of an equivalent circle having the same projected shape as the toner shape by the perimeter of the actual particles, and is preferably 0.900 to 0.980, for example, 0.950 to 0 .975 is more preferred. Note that particles having an average circularity of less than 0.94 are preferably 15% or less.
If the average circularity is less than 0.900, satisfactory transferability and a high-quality image free from dust may not be obtained. If the average circularity exceeds 0.980, image formation employing blade cleaning or the like is employed. In the system, defective cleaning occurs on the photoconductor and the transfer belt, and in the case of image formation with a high image area ratio such as a photographic image, an untransferred image is formed due to defective paper feeding, etc. The accumulated toner may become a transfer residual toner on the photoconductor, resulting in background smearing of the image, or it may contaminate the charging roller for charging the photoconductor in contact with the original charging ability. It may become impossible to demonstrate.

The average circularity is measured using a flow particle image analyzer (“FPIA-2100”, manufactured by Sysmex Corporation), and analyzed using analysis software (FPIA-2100 Data Processing Program for FPIA version 00-10). Can be obtained. Specifically, 0.1 to 0.5 ml of 10% by weight surfactant (alkylbenzene sulfonate, Neogen SC-A, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) is added to a 100 ml glass beaker, and each toner 0 is added. Add 1 to 0.5 g, stir with microspatel, then add 80 mL of ion exchange water, and disperse the resulting dispersion with an ultrasonic disperser (manufactured by Honda Electronics Co., Ltd.) for 3 minutes. Next, the shape and distribution of the toner are measured using the FPIA-2100 until the concentration of 5,000 to 15,000 / μL is obtained.
In this measurement method, it is important that the concentration of the dispersion is 5,000 / μL to 15,000 / μL from the viewpoint of measurement reproducibility of the average circularity. In order to obtain the concentration of the dispersion, it is necessary to change the conditions of the dispersion, that is, the amount of surfactant to be added and the amount of toner.
The amount of the surfactant varies depending on the hydrophobicity of the toner as in the measurement of the toner particle diameter described above. If it is added in a large amount, noise due to bubbles is generated, and if it is too small, the toner cannot be sufficiently wetted. It will be enough. The amount of toner added varies depending on the particle size, and is small when the particle size is small, and needs to be increased when the particle size is large. When the toner particle size is 3 μm to 10 μm, the toner amount is 0.1 g to 0.00 g. By adding 5 g, the dispersion concentration can be adjusted to 5,000 / μl to 15,000 / μl.

The volume average particle diameter of the toner can be appropriately selected according to the purpose, but is preferably 3 μm or more and 10 μm or less, and more preferably 3 μm or more and 8 μm or less.
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. Therefore, it becomes difficult to obtain a high-resolution and high-quality image, and when the balance of the toner in the developer is performed, the fluctuation of the toner particle diameter may increase.
Further, the ratio of the volume average particle diameter to the number average particle diameter of the toner (volume average particle diameter / number average particle diameter) is preferably from 1.00 to 1.25, and preferably from 1.00 to 1.16. More preferred.

The volume average particle diameter and the ratio of the volume average particle diameter to the number average particle diameter (volume average particle diameter / number average particle diameter) are measured using a particle size measuring device (“Multisizer III” manufactured by Beckman Coulter, Inc.). It can be obtained by measuring with an aperture diameter of 100 μm and analyzing with analysis software (Beckman Coulter Multisizer 3 Version 3.51).
Specifically, 0.5 ml of 10% by weight surfactant (alkylbenzene sulfonate, Neogen SC-A, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) is added to a 100 ml glass beaker, and 0.5 g of each toner is added. Then, 80 ml of ion exchange water is added, and the resulting dispersion is subjected to a dispersion treatment for 10 minutes with an ultrasonic disperser (W-113MK-II, manufactured by Honda Electronics Co., Ltd.). Next, the dispersion is measured using the Multisizer III and Isoton III (manufactured by Beckman Coulter, Inc.) as the measurement solution.

  The coloration of the toner is not particularly limited and may be appropriately selected according to the purpose. The toner 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.

  The image forming method of the present invention comprises an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier, and the electrostatic latent image is converted into the two-component developer of the present invention (hereinafter referred to as “development”). A developing process for forming a visible image by developing using an agent, a transfer process for transferring the visible image to a recording medium, and a fixing process for fixing the transferred image transferred to the recording medium. It is characterized by including at least. Hereinafter, a developer container, a process cartridge, an image forming apparatus, and the like used for carrying out the image forming method of the present invention will be described with examples.

<Developer>
The developer of the present invention is a two-component developer containing the carrier of the present invention and the toner.
The mixing ratio of the toner and the carrier in the developer is preferably 1.0 to 10.0 parts by mass of the toner with respect to 100 parts by mass of the carrier.

<Developer container>
The developer-containing container (developer storage container) contains the developer of the present invention in a container. There is no restriction | limiting in particular as a container, It can select suitably from well-known things, For example, the thing etc. which have a developer container main body and a cap are mentioned suitably. There is no restriction | limiting in particular about the magnitude | size, shape, structure, material, etc. as a developer container main body, According to the objective, it can select suitably.
As the shape, for example, a cylindrical shape or the like is preferable. Spiral irregularities are formed on the inner peripheral surface, and the developer as a content can be transferred to the discharge port side by rotating, and one of the spiral portions is formed. A part or all of which has a bellows function is particularly preferable.
There is no restriction | limiting in particular as a material of a developer container main body, A thing with good dimensional accuracy is preferable, for example, resin is mentioned suitably. Among the resins, for example, polyester resin, polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, polyacrylic acid, polycarbonate resin, ABS resin, polyacetal resin, and the like are preferable.
The developer-containing container is easy to store and transport, has excellent handleability, and can be suitably used for replenishing the developer by being detachably attached to a process cartridge, an image forming apparatus, and the like described later.

<Process cartridge>
The process cartridge used in the present invention, for example, develops an electrostatic latent image carrier carrying an electrostatic latent image and an electrostatic latent image carried on the electrostatic latent image carrier using a developer. And at least developing means for forming a visible image, and further having other means appropriately selected as necessary.
The developing means includes at least a developer container that contains the developer of the present invention, and a developer carrier that carries and conveys the developer contained in the developer container. Further, it may have a layer thickness regulating member for regulating the thickness of the toner layer to be carried as necessary.
The process cartridge can be detachably provided in various electrophotographic image forming apparatuses, and is preferably detachably provided in the image forming apparatus of the present invention described below.

  Here, for example, as shown in FIG. 2, the process cartridge includes a photosensitive member 101, and includes a charging unit 102, a developing unit 104, a transfer unit 108, and a cleaning unit 107, and other members as necessary. It has. In FIG. 2, reference numeral 103 denotes exposure by exposure means, and a light source capable of writing with high resolution is used. Reference numeral 105 denotes a recording medium. As the photoreceptor 101, the same one as an image forming apparatus described later can be used. An arbitrary charging member is used as the charging unit 102.

  Next, the image forming process using the process cartridge shown in FIG. 2 will be described. The photoconductor 101 is exposed to the surface by charging by the charging means 102 and exposure 103 by the exposure means (not shown) while rotating in the direction of the arrow. An electrostatic latent image corresponding to the image is formed. This electrostatic latent image is developed with toner by the developing unit 104 using the two-component developer of the present invention, and the toner image is transferred to the recording medium 105 by the transfer unit 108 and printed out. Next, the surface of the photoconductor after the image transfer is cleaned by the cleaning unit 107 and further neutralized by a neutralizing unit (not shown), and the above operation is repeated again.

<Image Forming Method and Image Forming Apparatus>
As described above, the image forming method of the present invention includes at least an electrostatic latent image forming step, a developing step, a transfer step, and a fixing step, and further, other steps appropriately selected as necessary, for example, static elimination. A process, a cleaning process, a recycling process, a control process, and the like can be included.
The image forming apparatus used in the image forming method of the present invention comprises at least an electrostatic latent image carrier, an electrostatic latent image forming unit, a developing unit, a transfer unit, and a fixing unit, and is further necessary. Other means appropriately selected according to the above, for example, a static elimination means, a cleaning means, a recycling means, a control means, and the like.

<< Electrostatic latent image forming step and charging means, exposure means >>
The electrostatic latent image forming step is a step of forming an electrostatic latent image on the electrostatic latent image carrier.
There are no particular restrictions on the material, shape, structure, size, etc. of the latent electrostatic image bearing member (sometimes referred to as “electrophotographic photosensitive member” or “photosensitive member”), It can be suitably selected from the inside. The shape is preferably a drum shape, and examples of the material include inorganic photoreceptors such as amorphous silicon and selenium, and organic photoreceptors (OPC) such as polysilane and phthalopolymethine. Among these, amorphous silicon or the like is preferable in terms of long life.

The formation of the electrostatic latent image can be performed, for example, by uniformly charging the surface of the electrostatic latent image carrier and then exposing it like an image, and by electrostatic latent image forming means. it can. The electrostatic latent image forming means includes, for example, at least a charger that uniformly charges the surface of the electrostatic latent image carrier and an exposure device that exposes the surface of the electrostatic latent image carrier imagewise.
Charging can be performed, for example, by applying a voltage to the surface of the electrostatic latent image carrier using a charger.

The charger is not particularly limited and may be appropriately selected depending on the purpose. For example, a known contact charging device including a conductive or semiconductive roll, brush, film, rubber blade, etc. And non-contact chargers using corona discharge such as corotrons, corotrons and scorotrons.
The charger is preferably one that is arranged in contact or non-contact with the electrostatic latent image carrier and charges the surface of the electrostatic latent image carrier by applying a direct current and an alternating voltage.
Further, the charger is a charging roller that is disposed in close proximity to the electrostatic latent image carrier via a gap tape, and the surface of the electrostatic latent image carrier is obtained by applying a direct current and an alternating voltage to the charging roller in a superimposed manner. Those that charge are preferable.

  The exposure can be performed, for example, by exposing the surface of the electrostatic latent image carrier imagewise using an exposure device. The exposure device is not particularly limited as long as exposure can be performed in an image-like manner to be formed on the surface of the electrostatic latent image carrier charged by the charger, and can be appropriately selected according to the purpose. Examples include various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system. In the present invention, a back light system in which imagewise exposure is performed from the back side of the electrostatic latent image carrier may be employed.

<< Development process and development means >>
The developing step is a step of developing the electrostatic latent image using the developer of the present invention to form a visible image.
The visible image can be formed, for example, by developing the electrostatic latent image using the developer of the present invention, and can be performed by the developing unit.
The developing means is not particularly limited as long as it can be developed using, for example, the developer of the present invention, and can be appropriately selected from known ones. For example, the developer of the present invention is accommodated. In addition, it is preferable to have at least a developing device that can apply the developer to the electrostatic latent image in a contact or non-contact manner, and a developing device including the developer-containing container is more preferable.

  The developing unit may be a dry developing type, a wet developing type, a single color developing unit, or a multi-color developing unit. For example, a developer having a stirrer for charging the developer by frictional stirring and a rotatable magnet roller is preferable.

In the developing device, for example, the toner and the carrier are mixed and agitated, and the toner is charged by friction at that time, and held on the surface of the rotating magnet roller in a raised state to form a magnetic brush. . Since the magnet roller is disposed in the vicinity of the electrostatic latent image carrier (photoconductor), a part of the toner constituting the magnetic brush formed on the surface of the magnet roller is electrically attracted. It moves to the surface of the electrostatic latent image carrier (photoconductor) by force. As a result, the electrostatic latent image is developed with the toner, and a visible image is formed with the toner on the surface of the electrostatic latent image carrier (photoconductor).
The developer accommodated in the developing device is the developer of the present invention.

<< Transfer process and transfer means >>
The transfer step is a step of transferring the visible image onto a recording medium. An intermediate transfer member is used, and after the primary image is transferred onto the intermediate transfer member, the visible image is transferred onto the recording medium. A secondary transfer mode is preferable, and a primary transfer step of forming a composite transfer image by transferring a visible image onto an intermediate transfer body using two or more colors, preferably a full color toner as the toner, and the composite transfer image And a secondary transfer step of transferring the image onto a recording medium is more preferable.

The transfer can be performed, for example, by charging an electrostatic latent image carrier (photoconductor) with a transfer charger using a transfer charger, and can be performed by the transfer unit. The transfer unit includes a primary transfer unit that transfers a visible image onto an intermediate transfer member to form a composite transfer image, and a secondary transfer unit that transfers the composite transfer image onto a recording medium. Is preferred.
The intermediate transfer member is not particularly limited and may be appropriately selected from known transfer members according to the purpose. For example, a transfer belt and the like are preferable.

The transfer means (the primary transfer means and the secondary transfer means) includes at least a transfer device that peels and charges the visible image formed on the electrostatic latent image carrier (photoconductor) to the recording medium side. It is preferable to have. There may be one transfer means, or two or more.
Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.
In addition, there is no restriction | limiting in particular as a recording medium, It can select suitably from well-known recording media (recording paper).

<< Fixing process and fixing means >>
The fixing step is a step of fixing the visible image transferred to the recording medium using a fixing device, and may be performed each time the developer of each color is transferred to the recording medium, or may be applied to the developer of each color. On the other hand, it may be performed simultaneously at the same time in a state of being laminated.
There is no restriction | limiting in particular as said fixing device, Although it can select suitably according to the objective, A well-known heating-pressing means is suitable. Examples of the heating and pressing means include a combination of a heating roller and a pressure roller, a combination of a heating roller, a pressure roller, and an endless belt.

The fixing device includes a heating body including a heating element, a film in contact with the heating body, and a pressure member in pressure contact with the heating body through the film, and between the film and the pressure member. It is preferably a means for passing through a recording medium on which an unfixed image is formed and fixing by heating. The heating in the heating and pressurizing means is usually preferably 80 ° C to 200 ° C.
In the present invention, for example, a known optical fixing device may be used together with or instead of the fixing step and the fixing unit depending on the purpose.

<< Static elimination process and static elimination means >>
The neutralization step is a step of performing neutralization by applying a neutralization bias to the electrostatic latent image carrier, and can be suitably performed by a neutralization unit.
The neutralizing means is not particularly limited as long as it can apply a neutralizing bias to the electrostatic latent image carrier, and can be appropriately selected from known neutralizers. For example, a neutralizing lamp is preferable. Can be mentioned.

<< Cleaning process and cleaning means >>
The cleaning step is a step of removing the toner remaining on the electrostatic latent image carrier and can be suitably performed by a cleaning unit.
There are no particular limitations on the cleaning means, and it is sufficient that the toner remaining on the electrostatic latent image carrier can be removed, and it can be appropriately selected from known cleaners. For example, a magnetic brush cleaner, electrostatic A brush cleaner, a magnetic roller cleaner, a blade cleaner, a brush cleaner, a web cleaner and the like are preferable.

<< Recycling process and recycling means >>
The recycling process is a process in which the toner removed by the cleaning process is recycled to the developing unit, and can be suitably performed by the recycling unit. There is no restriction | limiting in particular as a recycle means, A well-known conveyance means etc. are mentioned.

<< Control process and control means >>
A control process is a process of controlling each said process, and can perform each process suitably by a control means. The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.

  Here, an aspect of carrying out the image forming method of the present invention by the image forming apparatus will be described with reference to FIG. An image forming apparatus 100 shown in FIG. 3 includes a photosensitive drum 10 (photosensitive member 10) as the electrostatic latent image carrier, a charging roller 20 as the charging unit, and an exposure device 30 as the exposure unit. A developing device 40 as the developing means, an intermediate transfer member 50, a cleaning device 60 as the cleaning means having a cleaning blade, and a static elimination lamp 70 as the static elimination means.

  The intermediate transfer member 50 is an endless belt, and is designed so as to be movable in the direction of the arrow in the figure by three rollers 51 that are arranged on the inner side and stretch the belt. Part of the three rollers 51 also functions as a transfer bias roller that can apply a predetermined transfer bias (primary transfer bias) to the intermediate transfer member 50. An intermediate transfer member cleaning blade 90 is disposed in the vicinity of the intermediate transfer member 50, and a transfer bias for transferring a visible image (toner image) to the recording medium 95 (secondary transfer) is applied. Possible transfer rollers 80 as the transfer means are arranged to face each other. Around the intermediate transfer member 50, a corona charger 58 for applying a charge to the visible image on the intermediate transfer member 50 is connected to the electrostatic latent image carrier 10 in the rotation direction of the intermediate transfer member 50. The contact portion between the intermediate transfer member 50 and the contact portion between the intermediate transfer member 50 and the recording medium 95 is disposed.

  The developing device 40 includes a developing belt 41 as a developer carrying member, and a black developing unit 45K, a yellow developing unit 45Y, a magenta developing unit 45M, and a cyan developing unit 45C provided around the developing belt 41. Yes. The black developing unit 45K includes a developer accommodating portion 42K, a developer supply roller 43K, and a developing roller 44K. The yellow developing unit 45Y includes a developer container 42Y, a developer supply roller 43Y, and a developing roller 44Y. The magenta developing unit 45M includes a developer container 42M, a developer supply roller 43M, and a developing roller 44M. The cyan developing unit 45C includes a developer container 42C, a developer supply roller 43C, and a developing roller 44C. Further, the developing belt 41 is an endless belt, is rotatably stretched by a plurality of belt rollers, and a part thereof is in contact with the electrostatic latent image carrier 10.

  In the image forming apparatus 100 shown in FIG. 3, for example, the charging roller 20 uniformly charges the photosensitive drum 10. The exposure device 30 performs imagewise exposure on the photosensitive drum 10 to form an electrostatic latent image. The electrostatic latent image formed on the photosensitive drum 10 is developed by supplying toner from the developing device 40 to form a visible image (toner image). The visible image (toner image) is transferred (primary transfer) onto the intermediate transfer member 50 by the voltage applied from the roller 51, and further transferred (secondary transfer) onto the transfer paper 95. As a result, a transfer image is formed on the transfer paper 95. The residual toner on the photoconductor 10 is removed by the cleaning device 60, and the charge on the photoconductor 10 is temporarily removed by the charge eliminating lamp 70.

  Another mode for carrying out the image forming method of the present invention by the image forming apparatus will be described with reference to FIG. The image forming apparatus 100 shown in FIG. 4 does not include the developing belt 41 in the image forming apparatus 100 shown in FIG. 3, and a black developing unit 45K, a yellow developing unit 45Y, a magenta developing unit 45M, and the like around the photoconductor 10. Except for the fact that the cyan developing unit 45C is arranged directly opposite, it has the same configuration as the image forming apparatus 100 shown in FIG. In FIG. 4, the same components as those in FIG. 3 are denoted by the same reference numerals.

  Another mode for carrying out the image forming method of the present invention by the image forming apparatus will be described with reference to FIG. The tandem type image forming apparatus shown in FIG. 5 is a tandem type color image forming apparatus. The tandem image forming apparatus includes a copying apparatus main body 150, a paper feed table 200, a scanner 300, and an automatic document feeder (ADF) 400.

The copying apparatus main body 150 is provided with an endless belt-like intermediate transfer member 50 at the center. The intermediate transfer member 50 is stretched around the support rollers 14, 15 and 16, and can be rotated clockwise in FIG. 5. An intermediate transfer member cleaning device 17 for removing residual toner on the intermediate transfer member 50 is disposed in the vicinity of the support roller 15. The intermediate transfer member 50 stretched between the support roller 14 and the support roller 15 is a tandem type in which four image forming units 18 of yellow, cyan, magenta, and black are arranged to face each other along the conveyance direction. A developing device 120 is disposed. An exposure device 21 is disposed in the vicinity of the tandem developing device 120. A secondary transfer device 22 is disposed on the side of the intermediate transfer member 50 opposite to the side on which the tandem developing device 120 is disposed. In the secondary transfer device 22, a secondary transfer belt 24, which is an endless belt, is stretched around a pair of rollers 23, and the transfer paper conveyed on the secondary transfer belt 24 and the intermediate transfer body 50 are in contact with each other. Is possible. A fixing device 25 is disposed in the vicinity of the secondary transfer device 22. The fixing device 25 includes a fixing belt 26 that is an endless belt, and a pressure roller 27 that is pressed against the fixing belt 26.
In the tandem type image forming apparatus, a sheet reversing device 28 for reversing the transfer paper for image formation on both sides of the transfer paper is disposed in the vicinity of the secondary transfer device 22 and the fixing device 25. Yes.

Next, formation of a full-color image (color copy) using the tandem developing device 120 will be described.
First, a document is set on the document table 130 of the automatic document feeder (ADF) 400, or the automatic document feeder 400 is opened and a document is set on the contact glass 32 of the scanner 300, and the automatic document feeder 400 is set. close.
When a start switch (not shown) is pressed, when a document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32, and then the document is set on the contact glass 32. Immediately after that, the scanner 300 is driven, and the first traveling body 33 and the second traveling body 34 travel. At this time, light from the light source is irradiated by the first traveling body 33 and reflected light from the document surface is reflected by the mirror in the second traveling body 34 and is received by the reading sensor 36 through the imaging lens 35 to be color. An original (color image) is read and used as black, yellow, magenta, and cyan image information.

  Each image information of black, yellow, magenta, and cyan is stored in each image forming unit 18 (black image forming unit, yellow image forming unit, magenta image forming unit, and cyan image) in the tandem developing device 120. Each of the image forming units forms black, yellow, magenta, and cyan toner images. That is, each image forming means 18 (black image forming means, yellow image forming means, magenta image forming means, and cyan image forming means) in the tandem developing device 120 is electrostatically charged as shown in FIG. Latent image carrier 10 (black electrostatic latent image carrier 10K, yellow electrostatic latent image carrier 10Y, magenta electrostatic latent image carrier 10M, and cyan electrostatic latent image carrier 10C), and A charging device 160 for uniformly charging the electrostatic latent image carrier 10 and exposing the electrostatic latent image carrier to each color image corresponding image based on each color image information (L in FIG. 6), An exposure device that forms an electrostatic latent image corresponding to each color image on the electrostatic latent image carrier, and each color toner (black toner, yellow toner, magenta toner, and cyan toner) for the electrostatic latent image. Use A developing device 61 that develops and forms a toner image with each color toner, a transfer charger 62 for transferring the toner image onto the intermediate transfer member 50, a cleaning device 63, and a static eliminator 64 are provided. Each single-color image (black image, yellow image, magenta image, and cyan image) can be formed based on the image information of each color. The black image, the yellow image, the magenta image, and the cyan image formed in this way are respectively transferred to the black electrostatic latent image carrier 10K on the intermediate transfer member 50 that is rotationally moved by the support rollers 14, 15 and 16. Black image formed on top, yellow image formed on electrostatic latent image carrier 10Y for yellow, magenta image formed on electrostatic latent image carrier 10M for magenta, and electrostatic latent image carrier for cyan The cyan image formed on 10C is sequentially transferred (primary transfer). Then, the black image, the yellow image, the magenta image, and the cyan image are superimposed on the intermediate transfer member 50 to form a composite color image (color transfer image).

  On the other hand, in the paper feed table 200, one of the paper feed rollers 142 is selectively rotated to feed out a sheet (recording paper) from one of the paper feed cassettes 144 provided in multiple stages in the paper bank 143. Each sheet is separated and sent to the paper feed path 146, transported by the transport roller 147, guided to the paper feed path 148 in the copying machine main body 150, and abutted against the registration roller 49 and stopped. Alternatively, the sheet feed roller 142 is rotated to feed out sheets (recording paper) on the manual feed tray 54, separated one by one by the separation roller 145, put into the manual feed path 53, and abutted against the registration roller 49 and stopped. . The registration roller 49 is generally used while being grounded, but may be used in a state where a bias is applied to remove paper dust from the sheet. Then, the registration roller 49 is rotated in synchronization with the synthesized color image (color transfer image) synthesized on the intermediate transfer member 50, and a sheet (recording paper) is interposed between the intermediate transfer member 50 and the secondary transfer device 22. The secondary color transfer device 22 transfers the composite color image (color transfer image) onto the sheet (recording paper), thereby transferring the color image onto the sheet (recording paper). Is formed. The residual toner on the intermediate transfer member 50 after image transfer is cleaned by the intermediate transfer member cleaning device 17.

  The sheet (recording paper) on which the color image has been transferred is conveyed by the secondary transfer device 22 and sent to the fixing device 25, where the combined color image (color) is generated by heat and pressure. (Transfer image) is fixed on the sheet (recording paper). Thereafter, the sheet (recording paper) is switched by the switching claw 55 and discharged by the discharge roller 56 and stacked on the discharge tray 57, or switched by the switching claw 55 and reversed by the sheet reversing device 28 and transferred again. After being guided to the position and recording an image on the back surface, the image is discharged by the discharge roller 56 and stacked on the discharge tray 57.

  According to the image forming method of the present invention, since the two-component developer including the carrier of the present invention that has high mechanical strength, is free from toner scattering and scumming, and can form an image with high image density is used. Image quality images can be formed efficiently.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to these Examples at all.
First, a toner and a carrier for a two-component developer to be used in Examples and Comparative Examples were manufactured. Production Examples 1 to 4 are toner production examples, and Production Examples 5 to 11 are carrier production examples. Each production example is shown below.

(Production Example 1)
<Preparation of Toner 1>
-Synthesis of organic fine particle emulsion-
In a reaction vessel equipped with a stirrer and a thermometer, 683 parts by mass of water, 11 parts by mass of sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30, Sanyo Chemical Industries, Ltd.), 166 parts by mass of methacrylic acid Parts, 110 parts by mass of butyl acrylate, and 1 part by mass of ammonium persulfate were stirred at 3,800 rpm for 30 minutes to obtain a white emulsion. The system was heated to raise the system temperature to 75 ° C. and reacted for 4 hours. Subsequently, 30 parts by mass of a 1% by mass aqueous ammonium persulfate 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 [fine particle dispersion 1] was synthesized.
The obtained [Fine Particle Dispersion 1] was measured with a particle size distribution analyzer (LA-920, manufactured by Horiba, Ltd.), and the volume average particle size was 110 nm. Further, a portion of the obtained [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 was 130,000.

-Preparation of aqueous phase-
990 parts by weight of water, 83 parts by weight of [Fine Particle Dispersion 1], 37 parts by weight of an aqueous solution of 48.3% by weight of sodium dodecyl diphenyl ether disulfonate (Eleminol MON-7, Sanyo Chemical Industries, Ltd.), and ethyl acetate 90 parts by mass were mixed and stirred to obtain a milky white liquid. 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 introduction tube, 229 parts by mass of bisphenol A ethylene oxide 2-mole adduct, 529 parts by mass of bisphenol A propylene oxide 3-mole adduct, 208 parts by mass of terephthalic acid, 46 adipic acid 46 Part by mass and 2 parts by mass of dibutyltin oxide were added and reacted at 230 ° C. for 7 hours under normal pressure. Next, after 5 hours of reaction at a reduced pressure of 10 mmHg to 15 mmHg, 44 parts by weight of trimellitic anhydride was placed in the reaction vessel and reacted at 180 ° C. for 3 hours under normal pressure to synthesize [low molecular weight polyester 1]. did.
The obtained [Low molecular weight polyester 1] had a number average molecular weight of 2,300, a weight average molecular weight of 6,700, a glass transition temperature (Tg) of 43 ° C., and an acid value of 25 mgKOH / g.

-Synthesis of intermediate polyester and prepolymer-
In a reaction vessel equipped with a condenser, a stirrer, and a nitrogen introduction pipe, 81 parts by mass of bisphenol A ethylene oxide, 283 parts by mass of terephthalic acid, 22 parts by mass of trimellitic anhydride, and 682 parts by mass of dibutoxide 2-mole adduct, 2 parts by mass of bisphenol A propylene oxide 2 mol addition rutin oxide was added, reacted at 230 ° C. under normal pressure for 7 hours, and further reacted at reduced pressure of 10 mmHg to 15 mmHg for 5 hours to synthesize [Intermediate Polyester 1].
The obtained [Intermediate polyester 1] had a number average molecular weight of 2,200, a weight average molecular weight of 9,700, a glass transition temperature (Tg) of 54 ° C., an acid value of 0.5 mgKOH / g, and a hydroxyl value of 52 mgKOH / g. .

  Next, 410 parts by mass of [Intermediate Polyester 1], 89 parts by mass of isophorone diisocyanate, and 500 parts by mass of ethyl acetate are placed in a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube, and are heated at 100 ° C. for 5 hours. By reacting, [Prepolymer 1] was synthesized. The obtained [Prepolymer 1] had a free isocyanate weight% of 1.53%.

-Synthesis of ketimine-
In a reaction vessel equipped with a stir bar and a thermometer, 170 parts by mass of isophoronediamine and 75 parts by mass 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 [ketimine compound 1] was 417.

-Synthesis of master batch (MB)-
1200 parts by weight of water, 540 parts by weight of carbon black (Printex 35, manufactured by Dexa, DBP oil absorption = 42 ml / 100 mg, pH = 9.5), and 1,200 parts by weight of [low molecular polyester resin 1] were added, and a Henschel mixer was added. (Mitsui Mine Co., Ltd.) was mixed, and the mixture was kneaded at 110 ° C. for 1 hour using two rolls, rolled and cooled, and pulverized with a pulverizer to prepare [Masterbatch 1].

-Preparation of wax dispersion-
In a reaction vessel equipped with a stir bar and a thermometer, 378 parts by mass of the above-mentioned [low molecular weight polyester 1], 110 parts by mass of paraffin wax A (melting point 78 ° C.), and 947 parts by mass of ethyl acetate were charged, and the mixture was stirred up to 80 ° C. The temperature was raised and maintained at 80 ° C. for 5 hours, and then cooled to 30 ° C. over 1 hour to obtain [Wax Dispersion (1)]. The volume average particle size (Dv) of the wax dispersed particles contained in the obtained [wax dispersion (1)] is used to determine the particle size distribution measuring apparatus (“LA-920” manufactured by Horiba, Ltd.) using a laser light scattering method. It was 0.160 μm when measured by. The abundance of coarse particles having a volume average particle diameter (Dv) of 0.8 μm or more was 5% or less.

-Preparation of oil phase-
In 1435 parts by mass of [Wax Dispersion (1)], 500 parts by mass of [Masterbatch 1] and 500 parts by mass of ethyl acetate were charged and mixed for 1 hour to obtain a raw material solution.

1324 parts by mass of the obtained raw material solution was transferred to a reaction vessel, and using a bead mill (“Ultra Visco Mill”; manufactured by Imex Co., Ltd.), the liquid feeding speed was 1 kg / hr, the disk peripheral speed was 6 m / sec, and 0.5 mm zirconia. The carbon black and the wax were dispersed by three passes under the condition of 80% by volume of beads. Subsequently, 1324 parts by mass of a 65% by mass ethyl acetate solution of [low molecular polyester 1] was added to the dispersion. [Oil phase 1] was prepared by passing through a bead mill under the same conditions as above and dispersing.
The solid content concentration of the obtained [Oil Phase 2] (measurement condition: 130 ° C. by heating for 30 minutes) was 50% by mass.

-Emulsification and solvent removal-
[Oil Phase 1] 749 parts by mass, [Prepolymer 1] 115 parts by mass, and [Ketimine Compound 1] 2.9 parts by mass are placed in a container and 5,000 rpm with a TK homomixer (manufactured by Tokushu Kika Co., Ltd.). After mixing for 2 minutes, 1,200 parts by mass of [Aqueous phase 1] was added to the container and mixed with a TK homomixer at 13,000 rpm for 25 minutes to obtain [Emulsion slurry 1].
[Emulsion slurry 1] was put into a container equipped with a stirrer and a thermometer, and after removing the solvent for 8 hours at 30 ° C., aging was performed for 24 hours at 40 ° C. to obtain [Dispersion slurry 1].

-Washing and drying-
[Dispersion Slurry 1] After 100 parts by mass of filtration under reduced pressure, the following washing treatment was performed.
(1) 100 parts by mass of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered.
(2) 100 parts by mass of a 10% by mass 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 by mass of 10 mass% hydrochloric acid was added to the filter cake of (2), mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered.
(4) Add 300 parts by mass of ion-exchanged water to the filter cake of (3), mix with a TK homomixer (10 minutes at a rotation speed of 12,000 rpm), and then filter twice to perform [Filter cake 1]. Obtained.

  The obtained [Filter cake 1] was dried at 45 ° C. for 48 hours in a circulating drier. Thereafter, the resultant was sieved with a 75 μm mesh to produce toner base particles having a volume average particle size of 6.1 μm, a number average particle size of 5.4 μm, and an average circularity of 0.972.

-External toner addition-
Next, 0.7 parts by mass of hydrophobic silica and 0.3 parts by mass of hydrophobic titanium oxide were mixed with 100 parts by mass of the obtained toner base particles using a Henschel mixer to obtain “Toner 1” of Production Example 1. Produced. Various physical properties of the obtained [Toner 1] are shown in Table 2 below.

(Production Example 2)
<Preparation of Toner 2>
[Wax Dispersion (2)] was prepared in the same manner as in Production Example 1 except that the paraffin wax A in Production Example 1 was changed to polypropylene rubber (melting point: 86 ° C.). Produced. The volume average particle size (Dv) of the wax-dispersed particles contained in the obtained [wax dispersion (2)] is used to measure the particle size distribution measuring apparatus (“LA-920” manufactured by Horiba, Ltd.) using a laser light scattering method. As a result, it was 0.162 μm. The abundance of coarse particles having a volume average particle diameter (Dv) of 0.8 μm or more was 5% or less.
Various physical properties of the obtained [Toner 2] were measured in the same manner as in Production Example 1. The results are shown in Table 2 below.

(Production Example 3)
<Preparation of Toner 3>
[Wax Dispersion (3)] was prepared in the same manner as in Production Example 1 except that the paraffin wax A in Production Example 1 was changed to 660 parts by mass of carnauba wax (melting point: 82 ° C.). ] Was produced.
Various physical properties of the obtained [Toner 3] were measured in the same manner as in Production Example 1. The results are shown in Table 2 below.

(Production Example 4)
<Preparation of Toner 4>
724 parts of bisphenol A ethylene oxide 2-mole adduct, 276 parts of isophthalic acid and 2 parts of dibutyltin oxide were placed in a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube and reacted at 230 ° C. for 8 hours at normal pressure. The reaction was further carried out at a reduced pressure of 10 to 15 mmHg for 5 hours, followed by cooling to 160 ° C., and 32 parts of phthalic anhydride was added thereto and reacted for 2 hours. Next, the mixture was cooled to 80 ° C. and reacted with 188 parts of isophorone diisocyanate in ethyl acetate for 2 hours to obtain [Prepolymer 4]. Next, 267 parts of [Prepolymer 4] and 14 parts of isophoronediamine were reacted at 50 ° C. for 2 hours to obtain [Crosslinked Polyester] having a weight average molecular weight of 64,000.

The composition of the following formulation using [Crosslinked Polyester] obtained above and [Low Molecular Polyester 1], [Masterbatch 1] etc. is kneaded at 100 ° C. using a biaxial extruder, pulverized and classified. Toner particles were obtained. Next, 0.7 parts by mass of hydrophobic silica and 0.3 parts by mass of hydrophobic titanium oxide were mixed with 100 parts by mass of the obtained toner particles using a Henschel mixer to produce [Toner 4] of Production Example 4. did.
Various physical properties of the obtained [Toner 4] were measured in the same manner as in Production Example 1. The results are shown in Table 2 below.

<Prescription>
Low molecular weight polyester 1:85 parts by mass Crosslinked polyester: 15 parts by mass
Carnauba wax (melting point 82 ° C.): 7 parts by mass
Masterbatch 1: 6 parts by mass
Charge control agent E-84 (manufactured by Orient Chemical Co., Ltd.): 1 part by mass

(Production Example 5)
<Preparation of carrier 1>
A 4-necked flask equipped with a nitrogen inlet tube and a thermometer was charged with 71.4 parts by mass of methyltrimethoxysilane, 12.5 parts by mass of ethyl acetoacetate, and 112.6 parts by mass of isopropyl alcohol, while bubbling nitrogen. Stirred uniformly.
Separately, 37.5 parts by weight of Snowtex O40 (manufactured by Nissan Chemical Industries, Ltd., solid concentration 40 wt%), 4.5 parts by weight of 1 mol / l acetic acid aqueous solution, and 11.1 parts by weight of distilled water were mixed until uniform. This was dripped at the said 4 necked flask with the dropping funnel. At this time, the temperature in the flask was kept at 35 ° C. After completion of the dropwise addition, the temperature was maintained at 35 ° C. for 30 minutes, and then the temperature was raised to 60 ° C. over 30 minutes and reacted for 3 hours.
Next, after diluting the obtained solution with toluene so that the solid content concentration becomes 15 wt%, an aminosilane coupling agent (manufactured by Toray Dow Corning Co., Ltd., SH6020, solid content 100 mass%) is added to the total solid content. [Coating layer solution 1] was obtained by adding the mixture so as to be 1 wt% with respect to the mixture and mixing for 10 minutes using a homomixer.

  Next, a ferrite powder (saturation magnetic moment 65 emu / g at 1 k gauss) is used as a core material, and a rolling fluid type coating apparatus is used so that the [coating layer liquid 1] has a thickness of 1.5 μm on the core material surface. Applied and dried. The obtained carrier was baked by standing at 120 ° C. for 30 minutes in an electric furnace, and after cooling, the ferrite powder bulk was crushed using a sieve having an opening of 90 μm to obtain [Carrier 1] of Production Example 5 It was.

  When the particle size distribution of the obtained [Carrier 1] was measured with a Microtrac particle size distribution analyzer (model HRA9320-X100), the weight average particle size (Dw) was 39.3 μm and the number average particle size (Dn) was 34.5 μm. Dw / Dn was 1.14. The volume resistivity of [Carrier 1] was 15.8 [Log (Ω · cm)]. In addition, the thickness (h) of the coating layer of [Carrier 1] was determined by cutting the coated particles with FIB (focused ion beam) to create a cross section of the coated particles, and then using a transmission electron microscope (TEM) or a scanning transmission electron microscope. Using (STEM), the average value of the film thicknesses obtained by observing cross sections of 50 or more coated particles was 1.43 μm. Various physical properties of the obtained [Carrier 1] are shown in Table 3 below.

(Production Example 6)
<Production of Carrier 2>
In Production Example 5, 71.4 parts by mass of methyltrimethoxysilane, 12.5 parts by mass of ethyl acetoacetate, 112.6 parts by mass of isopropyl alcohol, 64.2 parts by mass of methyltrimethoxysilane, 0.9 Parts by weight of methyl silicate-51 (manufactured by Tama Chemical Co., Ltd.), 4.3 parts by weight of hexyltrimethoxysilane, 2.1 parts by weight of γ-glycidoxypropyltrimethoxysilane, 12.5 parts by weight of acetoacetic acid [Carrier 2] of Production Example 6 was produced in the same manner as in Production Example 5 except that ethyl, 87.6 parts by mass of isopropyl alcohol, and 25 parts by mass of isobutanol were used.
Various physical properties of the obtained [Carrier 2] were measured in the same manner as in Production Example 5. The results are shown in Table 3 below.

(Production Example 7)
<Preparation of carrier 3>
A 4-necked flask equipped with a nitrogen inlet tube and a thermometer was charged with 71.4 parts by mass of methyltrimethoxysilane, 12.5 parts by mass of ethyl acetoacetate, and 112.6 parts by mass of isopropyl alcohol, while bubbling nitrogen. Stirred uniformly.
Separately, 37.5 parts by weight of Snowtex O40 (manufactured by Nissan Chemical Industries, Ltd., solid concentration 40 wt%), 4.5 parts by weight of 1 mol / l acetic acid aqueous solution, and 11.1 parts by weight of distilled water were mixed until uniform. This was dripped at the said 4 necked flask with the dropping funnel. At this time, the temperature in the flask was kept at 35 ° C. After completion of the dropwise addition, the temperature was maintained at 35 ° C. for 30 minutes, and then the temperature was raised to 60 ° C. over 30 minutes and reacted for 3 hours.
Next, 40 parts by mass of spherical alumina fine particles having a particle diameter of 0.4 μm were added to the resulting solution, diluted with toluene so that the solid content concentration became 15 wt%, and then an aminosilane coupling agent (Toray Dow Corning). Co., Ltd., SH6020, solid content of 100% by mass) was added to 1 wt% with respect to the total solid content, and mixed for 10 minutes using a homomixer to obtain [Coating Layer Liquid 3].

Next, using a ferrite powder (saturation magnetic moment 65 emu / g at 1 k gauss) as a core material, a rolling fluid type coating apparatus is used so that the [coating layer solution 3] has a thickness of 1.5 μm on the surface of the core material. Applied and dried. The obtained carrier was baked by standing at 120 ° C. for 30 minutes in an electric furnace, and after cooling, the ferrite powder bulk was crushed using a sieve having an opening of 90 μm to obtain [Carrier 3] of Production Example 7 It was.
Various physical properties of the obtained [Carrier 3] were measured in the same manner as in Production Example 5. The results are shown in Table 2.

(Production Example 8)
<Preparation of carrier 4>
[Carrier 4] of Production Example 8 was produced in the same manner as in Production Example 5 except that 37.5 parts by mass of Snowtex O40 of Production Example 5 was changed to 75 parts by mass.
Various physical properties of the obtained [Carrier 4] were measured in the same manner as in Production Example 5. The results are shown in Table 3 below.

(Production Example 9)
<Preparation of carrier 5>
[Carrier 5] of Production Example 9 was produced in the same manner as in Production Example 5, except that the coating layer liquid was applied to the core material surface so as to have a thickness of 0.5 μm in Production Example 5.
Various physical properties of the obtained [Carrier 5] were measured in the same manner as in Production Example 5. The results are shown in Table 3 below.

(Production Example 10)
<Preparation of carrier 6>
The following material composition was diluted with toluene so that the solid concentration was 15%, and then dispersed with a homomixer for 10 minutes to prepare [Coating Layer Liquid 6].
<Material composition>
Acrylic resin solution (manufactured by Hitachi Chemical Co., Ltd., Hitaroid 3018 solid content 50% by mass): 30 parts by mass Guanamin solution (Mitsui Cytec Co., Ltd., Mycoat 106,
Solid content 77% by mass): 10 parts by mass Silicone resin solution (manufactured by Dow Corning Toray, SR2405,
Solid content 50% by mass): 60 parts by mass Aminosilane coupling agent (manufactured by Dow Corning Toray, SH6020,
Solid content: 100% by mass): 1 part by mass ・ Particle size: 0.4 μm Spherical alumina fine particles: 40 parts by mass

Next, a ferrite fluid (saturation magnetic moment 65 emu / g at 1 k gauss) is used as a core material, and a rolling fluid type coating apparatus is used so that the [coating layer liquid 6] has a thickness of 1.5 μm on the surface of the core material. Applied and dried. The obtained carrier was baked by standing at 120 ° C. for 30 minutes in an electric furnace, and after cooling, the ferrite powder bulk was pulverized using a sieve having an opening of 90 μm to obtain [Carrier 6] of Production Example 10 It was.
Various physical properties of the obtained [Carrier 6] were measured in the same manner as in Production Example 5. The results are shown in Table 3 below.

(Production Example 11)
<Creation of carrier 7>
After dissolving 13.5 parts by mass of Zn (OAc) ₂ .2H ₂ O in a mixed liquid of 62 parts by mass of water and 75 parts by mass of ethanol, 2 parts by mass of 6N hydrochloric acid was added and refluxed for 30 minutes. Then, it diluted with 5 mass parts of acetic acid, 10 mass parts of 1-butanol, 20 mass parts of 2-ethoxyethanol, and 5 mass parts of diethylene glycol. Furthermore, (Toray Dow Corning Co., Ltd., SH6020, solid content 100% by mass) was added to this solution so as to be 1% by mass with respect to the total solid content, thereby preparing [Coating Layer Liquid 7].

Next, a ferrite fluid (saturation magnetic moment 65 emu / g at 1 k gauss) is used as a core material, and a rolling fluid type coating apparatus is used so that the [coating layer liquid 7] has a thickness of 1.5 μm on the core material surface. Applied and dried. The obtained carrier was baked by standing at 200 ° C. for 120 minutes in an electric furnace, and after cooling, the ferrite powder bulk was pulverized using a sieve having an opening of 90 μm to obtain [Carrier 7] of Production Example 7 It was.
Various physical properties of the obtained [Carrier 7] were measured in the same manner as in Production Example 5. The results are shown in Table 3 below.

(Examples 1-6 and Comparative Examples 1-8)
The toners 1 to 4 and the carriers 1 to 7 prepared above were combined into the two-component developers shown in Table 4 below. That is, the developer of Examples 1 to 6 and Comparative Examples 1 to 8 was prepared by adjusting the ratio of carrier coverage with toner to 50% and stirring with a tumbler mixer (manufactured by Shinmaru Enterprises).
Using each developer thus obtained, peeling and scraping of the coating layer, toner spent property, image density, toner scattering property, and background stain were evaluated under the following conditions. The results are shown in Table 4 below.

<Evaluation of peeling and shaving of coating layer>
Each developed developer was evaluated for 200,000 sheets using a tandem color image forming apparatus (image Neo 450, manufactured by Ricoh Co., Ltd.). evaluated.
〔Evaluation criteria〕
A: Ratio of resistance after 200,000 sheets run / initial resistance within 1 to 1/10 ○: Ratio of resistance after 200,000 sheets run / initial resistance of run within 1/10 to 1/100 Δ: Ratio of resistance after 200,000 sheets run / resistance at initial stage of run is within 1/100 to 1/1000 x: Ratio of resistance after 200,000 sheets run / initial resistance of run is less than 1/1000

  Here, the amount of resistance reduction refers to an initial carrier introduced between resistance measuring parallel electrodes: electrodes having a gap of 2 mm, and a resistance value after 30 sec after applying DC 200 V is measured with a high resist meter (manufactured by Yokogawa Hewlett-Packard Co., High Resistance). From the value (R1) obtained by converting the value measured by Meter) into the volume resistivity, the carrier in which the toner in the developer after running is removed by the blow-off device is measured by the same method as the resistance measuring method. The target value is 2.0 [Log (Ω · cm)] or less. Moreover, since the cause of resistance reduction is detachment | desorption from the core material of the coating layer of a carrier, the amount of resistance reduction can be suppressed by reducing scraping.

<Evaluation of toner spent property>
Using the tandem color image forming apparatus (image Neo 450, manufactured by Ricoh Co., Ltd.), control the toner density so that the 20% image area chart has an image density of 1.4 ± 0.2. However, the amount of change in developer charge amount (μc / g) after output of 200,000 sheets was evaluated according to the following criteria in comparison with the initial agent before output. The charge amount was measured by a blow-off method.
〔Evaluation criteria〕
◯: Ratio of charge amount after 200,000 sheet run / initial charge amount within 0 to 30% Δ: Ratio of charge amount after 200,000 sheet run / initial charge amount within 30 to 50% ×: Ratio of charge amount after 200,000 sheets run / charge amount at the beginning of run is greater than 50%

  As the toner spends on the carrier, the composition on the outermost surface of the carrier changes, and the charge amount decreases. It is determined that the smaller the ratio of the charge amount before and after the run, the less the toner spent on the carrier.

<Evaluation of image density>
Next, each developer obtained was attached to copy paper (TYPE6000 <70W>, manufactured by Ricoh Co., Ltd.) using a tandem color image forming apparatus (image Neo 450, manufactured by Ricoh Co., Ltd.). A solid image having an amount of 1.00 ± 0.05 mg / cm ² was formed. The solid image was repeatedly formed on 200,000 copy sheets.
The image density of the obtained solid image was visually observed for the initial stage and after the endurance of 200,000 sheets, and evaluated based on the following criteria. Note that the higher the image density obtained, the higher the density image can be formed. This evaluation corresponds to an example of the developer and the image forming method of the present invention.
〔Evaluation criteria〕
A: Image density did not change at the initial stage and after endurance of 200,000 sheets, and high image quality was obtained. ○: After endurance of 200,000 sheets, image density decreased slightly, but high image quality was obtained. Δ: 20 Image density decreased and image quality deteriorated after endurance of 10,000 sheets. ×: Image density significantly decreased and image quality significantly decreased after endurance of 200,000 sheets.

<Evaluation of toner scattering property>
The degree of toner contamination in the machine when a chart with an image area ratio of 5% is continuously output 200,000 sheets using a tandem color image forming apparatus (Imagio Neo 450, manufactured by Ricoh Co., Ltd.) is visually checked as follows. Based on 4 grades.
〔Evaluation criteria〕
A: There is no toner contamination in the image forming apparatus and it is in a good state. ○: There is no toner contamination in the image forming apparatus and it is in a good state. Δ: There is toner contamination in the image forming apparatus, but it is actually used. Possible level ×: Toner contamination in the image forming apparatus is severe and is not practically usable.

<Evaluation of dirt>
By visually observing the degree of background contamination of the image background portion when 200,000 sheets of a chart with an image area ratio of 5% were continuously output using a tandem type color image forming apparatus (image Neo 450, manufactured by Ricoh Co., Ltd.), Evaluated by criteria.
〔Evaluation criteria〕
○: No background stain on the image background △: Some background stain on the image background ×: Background stain on the image background

<Comprehensive evaluation>
From the above evaluation results, the following criteria were used for overall evaluation.
〔Evaluation criteria〕
◎: Very good ○: Good ×: Bad

From the results of Table 4, in all of Examples 1 to 6, the coating layer is less peeled and scraped than Comparative Examples 1 to 8, and at the same time, the toner spent is less likely to occur. And a high image density was obtained, and the overall result was very good or good.
On the other hand, in Comparative Example 1, the amount of wax present in the depth region from the surface of the toner 3 to 0.3 μm greatly exceeds the preferable range (less than 4% by mass). Therefore, the toner spent and toner scattering properties are very poor. In Comparative Example 2, although the amount of surface wax exceeds 4% by mass but is not greatly deviated, the toner scattering property is improved, but the toner spent ratio is still more than 50% and satisfies the standard. Not.
In Comparative Example 3, the content of the colloidal silica of the carrier 4 is not less than 60% by mass, and is particularly outside the more preferable range (0.5% by mass to 50% by mass) described in the specification text. Except for the toner spent property, all the standards are not satisfied. That is, the coating layer thickness is set so that the ratio (h / D _W ) between the coating layer thickness h and the volume average particle diameter D _W of the carrier is in the range of 0.025 <h / D _W <0.2. When controlled, the carrier coating layer could not maintain sufficient strength due to the excessive colloidal silica component, and peeling and abrasion progressed, resulting in deterioration in image quality.
Further, the carrier of the developer of Comparative Examples 4 and 5 has a ratio (h / D _W ) of the coating layer thickness h to the volume average particle diameter D _W of the carrier of 0.01. Since it is outside the more preferable range (0.025 <h / D _W <0.2) described in the above, a sufficiently durable coating layer is not formed in a long-term run. For this reason, the peeling and abrasion of the coating layer proceeded over time, and as a result, the image density, toner scattering property, and soiling were deteriorated.
The developers of Comparative Example 1 and Comparative Example 5 using a toner having a very large surface wax amount of 13.1% by mass have a large amount of wax present in the vicinity of the toner surface, and the toner spent that seems to be derived from the wax component. Worsened.
Further, the same remarkable toner spent property deterioration was confirmed even in the developers of Comparative Examples 2 and 7 using the toner prepared by the pulverization method. Further, both Comparative Example 7 and Comparative Example 8 are materials using completely different materials from the coating layer binding material composed of the colloidal silica of the present invention and the condensate of alkoxysilane having a specific structure. No results were obtained.
As can be seen from the above results, the use of the two-component developer comprising the carrier of the present invention and the toner having a controlled amount of the carrier and the surface release agent enables the coating layer to be peeled off and scraped even in long-term use. It is possible to form an image free from problems such as spent property, image density, toner scattering property, and background contamination.

It is a schematic perspective view which shows the measuring device used for the measurement of the volume resistance (R) of the carrier in this invention. It is a schematic block diagram which shows an example of the process cartridge used in this invention. It is a schematic explanatory drawing which shows an example which implements the image forming method of this invention with an image forming apparatus. It is a schematic explanatory drawing which shows the other example which implements the image forming method of this invention with an image forming apparatus. It is a schematic explanatory drawing which shows an example which implements the image forming method of this invention with an image forming apparatus (tandem type color image forming apparatus). FIG. 6 is a partially enlarged schematic explanatory diagram of the image forming apparatus shown in FIG. 5.

Explanation of symbols

1 Electrode 2 Electrode 3 Cell 4 Carrier 10 Electrostatic latent image carrier (photosensitive drum)
10K Electrostatic latent image carrier for black 10Y Electrostatic latent image carrier for yellow 10M Electrostatic latent image carrier for magenta 10C Electrostatic latent image carrier for cyan 14 Support roller 15 Support roller 16 Support roller 17 Intermediate transfer cleaning device DESCRIPTION OF SYMBOLS 18 Image forming means 20 Charging roller 21 Exposure device 22 Secondary transfer device 23 Roller 24 Secondary transfer belt 25 Fixing device 26 Fixing belt 27 Pressure belt 28 Sheet reversing device 30 Exposure device 32 Contact glass 33 First traveling body 34 Second Traveling body 35 Imaging lens 36 Reading sensor 40 Developing device 41 Developing belt 42K Developer container 42Y Developer container 42M Developer container 42C Developer container 43K Developer supply roller 43Y Developer supply roller 43M Developer supply roller 43C Developer supply roller 44K Development roller La 44Y Development roller 44M Development roller 44C Development roller 45K Black development unit 45Y Yellow development unit 45M Magenta development unit 45C Cyan development unit 49 Registration roller 50 Intermediate transfer member 51 Roller 52 Separation roller 53 Manual feed path 54 Manual feed tray 55 switching claw 56 discharge roller 57 discharge tray 58 corona charger 60 cleaning device 61 developing device 62 transfer charger 63 photoconductor cleaning device 64 discharger 70 discharge lamp 80 transfer roller 90 cleaning device 95 transfer paper 100 image forming device 101 electrostatic Latent image carrier (photoconductor)
DESCRIPTION OF SYMBOLS 102 Charging means 103 Exposure 104 Developing means 105 Recording medium 107 Cleaning means 108 Transfer means 110 Carrier processing tank 112 Raw material recovery tank 113 Carbon dioxide cylinder 114 Stirrer 115 Stirrer 116 Entrainer tank 117 Cooling jacket 118 Temperature control jacket 120 Tandem developer 121 Heating roller 122 Fixing roller 123 Fixing belt 124 Pressure roller 125 Heating source 126 Cleaning roller 127 Temperature sensor 130 Document table 142 Paper feed roller 143 Paper bank 144 Paper feed cassette 145 Separation roller 146 Paper feed path 147 Transport roller 148 Paper feed path 150 Copier Main Body 160 Charging Device 200 Paper Feed Table 300 Scanner 400 Automatic Document Feeder (ADF)

Claims (14)

A carrier for a two-component developer used together with a toner containing at least a colorant, a binder resin and a release agent and obtained by aqueous granulation,
The amount of the release agent present in the depth region from the toner surface to 0.3 μm determined by FTIR-ATR (total reflection absorption infrared spectroscopy) is less than 4% by mass; and
The carrier has at least core particles made of a magnetic material, and a coating layer on the surface of the core material particles. The coating layer is made of at least colloidal silica and an alkoxysilane represented by the following general formula (1). It is applied and formed using a condensate and a coating layer solution containing a solvent,
The content of colloidal silica contained in the coating layer is less than 60% by mass, and the ratio (h / D _W ) between the film thickness h of the coating layer and the volume average particle diameter D _W of the carrier is 0.01. A carrier characterized by being larger than.
Si (R ¹ ) _a (R ² ) _4-a (1)
[Wherein, R ¹ represents an alkyl group having 1 to 10 carbon atoms, R ² represents an alkoxy group having 1 to 10 carbon atoms, an alkenyloxy group, an acyloxy group, or an alkoxyalkoxy group, and a represents 0, 1, or 2 It is an integer. ]   The carrier according to claim 1, wherein the content of colloidal silica in the coating layer is 0.5 mass% or more and 50 mass% or less. The carrier according to claim 1, wherein the h / D _W is in a range of 0.025 <h / D _W <0.2. The carrier according to claim 1, wherein the carrier has a volume average particle diameter D _W of 20 to 65 μm.   The carrier according to any one of claims 1 to 4, wherein the molecular weight of the alkoxysilane condensate represented by the general formula (1) is 1000 or less.   The carrier according to any one of claims 1 to 5, wherein the coating layer is applied and formed using a coating layer solution further containing an aminosilane coupling agent. From the resistance value r measured by filling the carrier with a cell provided with electrodes 1 and 2 having a distance between electrodes of 0.2 cm and a surface area of 2.5 cm × 4 cm, and applying a DC voltage of 1000 V between the electrodes. The volume resistance R calculated | required by following formula (1) is 10 [Log (ohm * cm)] or more and 16 [Log (ohm * cm)] or less, The any one of Claims 1-6 characterized by the above-mentioned. Career.
R = Log [r × (2.5 cm × 4 cm) ÷ 0.2 cm] (1)   A carrier according to any one of claims 1 to 7 and a toner obtained by water-based granulation containing at least a colorant, a binder resin and a release agent, and comprising FTIR-ATR (total reflection absorption infrared) A two-component developer characterized in that the amount of the release agent present in a depth region from the surface of the toner to 0.3 μm determined by (spectrometry) is less than 4% by mass.   The two-component developer according to claim 8, wherein the binder resin contained in the toner is a polyester resin.   The two-component developer according to claim 8 or 9, wherein the binder resin contains a modified polyester having a substituent capable of reacting with an active hydrogen group at a terminal.   The release agent is a wax, and the content of the wax with respect to the whole toner is 1 to 20% by mass in terms of mass converted from the endothermic amount of the wax determined by a DSC (Differential Scanning Calorimetry) method. The amount of the wax existing in a depth region from the surface to 0.3 μm determined by FTIR-ATR (total reflection absorption infrared spectroscopy) is 0.1% by mass or more and less than 4% by mass. The two-component developer according to any one of claims 8 to 10.   The two-component developer according to any one of claims 8 to 11, wherein the toner has a volume average particle diameter of 3 µm or more and 8 µm or less.   The ratio of the volume average particle diameter to the number average particle diameter of the toner (volume average particle diameter / number average particle diameter) is 1.00 or more and 1.25 or less. The two-component developer described.   An electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier, and developing the electrostatic latent image using the two-component developer according to any one of claims 8 to 13. An image forming method comprising at least a developing step for forming a visible image, a transferring step for transferring the visible image to a recording medium, and a fixing step for fixing the transferred image transferred to the recording medium. .

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