JP2006065194A - Image forming method, toner for the same, process cartridge, and image forming apparatus - Google Patents

Abstract

Image formation capable of improving image quality by preventing reverse transfer to a recording medium due to melting of toner fixed to a cleaning member via a heating member and / or a pressure member of a heat fixing device Methods and toners used therein are provided.
The toner composition contains at least a colorant, a release agent, a first binder resin and a second binder resin, and the first binder resin has a glass transition point of 30 to 46 ° C. The second binder resin is composed of a THF-insoluble component, and its content in the total composition is 5 to 25 wt%. The release agents are dispersed in the resin independently of each other. Then, an image forming toner having a content of 2 to 10 wt% in the total composition is used. The 1/2 outflow temperature (T2) measured by the flow tester of the toner fixed to the cleaning member 4 is 120 to 140 ° C., and the relationship with the 1/2 outflow temperature (T1) of the toner used in the development process is T1 + 10. <T2 (° C.) toner is used.
[Selection] Figure 1

Description

  The present invention relates to an image forming method such as, for example, a copying machine, a printer, a facsimile, or a composite machine thereof, and also relates to an electrophotographic dry toner and an electrophotographic developer, a process cartridge, and an image forming apparatus. The present invention relates to an image forming technique for preventing toner attached to a heating member and / or a pressure member from being reversely transferred to a recording medium again in a fixing process using a thermal fixing device.

  Conventionally, in an electrophotographic image forming apparatus, a pressure member such as a pressure roller is pressed against a heating member such as a heating roller having a heat source therein, and the recording medium is passed through the recording medium after image transfer between them. Many of them include a thermal fixing device that fixes a toner image on the recording medium while being conveyed.

  In this type of heat fixing apparatus, a phenomenon called so-called offset may occur in which the toner on the recording medium adheres to the heating member. It is known that when such an offset occurs, the offset toner adheres to the pressure member, and the toner is reversely transferred to the recording medium via the heating member and the pressure member to contaminate the recording medium.

  In order to prevent such an offset, in the conventional thermal fixing apparatus, for example, the surface of the heating member is coated with fluorine. However, it is difficult to completely prevent the offset depending on the environmental conditions and the type of the recording medium, and there is still a problem that reverse transfer occurs.

  For this reason, some conventional thermal fixing devices are provided with a cleaning member such as a cleaning roller so as to come into contact with the heating member or the pressure member, and remove the toner adhering to the heating member or the pressure member. That is, there is a device that removes toner by utilizing the difference in surface releasability by pressing a cleaning member made of a solid metal material against the surface of a heating member or pressure member having improved surface releasability. there were.

  Incidentally, in recent years, in order to prevent wasteful consumption of energy, the energization of the heat source is stopped when the image forming apparatus is on standby, and the heating member is energized to the fixing temperature by energizing the heat source at the start of image formation. It is becoming. For this reason, it is necessary to improve the temperature responsiveness of the heating member. For example, in the case of a heating roller, the wall thickness is 1 mm or less, and the temperature rise time to the fixing temperature is shortened to about 10 seconds.

  However, in the case of the image forming apparatus as described above, since the heat capacity of the heating member is small, heat transfer to the recording medium at the time of fixing, heat transfer to the member in contact with the heating member, wind flow around the heating member, etc. There is a problem that the temperature distribution of the heating member tends to be uneven in the width direction. And it was difficult to make the temperature distribution uniform over the entire region of the heating member in terms of space and cost.

  Usually, when the temperature distribution of the heating member is not uniform in the width direction, the fixing performance becomes unstable, and an offset is likely to occur, and the life of the heating member is likely to be shortened due to thermal deterioration. In particular, when a so-called polymerized toner manufactured by a polymerization method is used, there is a problem in that a toner lump that adheres and accumulates on the cleaning member is remelted and reversely transferred to a recording medium. That is, when polymerized toner is used, toner having a low storage elastic modulus adheres to the cleaning member. When a pulverized toner manufactured by a pulverization method is used, a toner having a higher storage elastic modulus and less soluble than the polymerized toner adheres to the cleaning member.

  The problem of reverse transfer is particularly noticeable when a recording medium having a size smaller than the maximum size that can be passed is passed. The reason for this is that, in the case of a small size, the paper passing area is narrow and the area in contact with the heating member is small, so the temperature falls only in that narrow area, and the temperature detection means corresponding to that part instructs the lighting of the heat source. This is because the toner on the cleaning member corresponding to the non-sheet-passing area is unnecessarily increased to the temperature of the non-sheet-passing area and the toner on the cleaning member corresponding to the non-sheet-passing area is melted and reversely transferred due to the temperature increase.

In order to solve such a problem of non-uniform temperature distribution, a technique has been proposed in which cooling air is introduced by a blower and the temperature distribution of the fixing roller of the heat fixing device is made uniform in the axial direction (for example, Patent Documents). 1).
In addition, a ventilation port is provided at a position facing the entire axial direction of the cleaning roller, and air in the fixing device is circulated by a blower blade provided at the end of the shaft as the cleaning roller rotates, thereby preventing the temperature of the cleaning roller from rising. Has been proposed (see, for example, Patent Document 2).
However, none of the above techniques is sufficient when the polymerized toner is used, and there are problems such as a complicated apparatus configuration, a new configuration space, and an increase in cost. is there.

On the other hand, the particle size of the toner is being reduced in order to improve the image quality of the image, and the resolution and sharpness of the image are improved by the particle size reduction. However, there is a problem that the fixing property of the toner is deteriorated in a halftone portion formed of toner having a small particle diameter. This phenomenon is particularly noticeable in high-speed fixing. This is because the toner “attachment amount” in the halftone portion is small, and the toner transferred to the concave portion of the fixing sheet as the recording medium has a small amount of heat applied from the heating roller, and the convex portion of the fixing sheet. This is because the fixing pressure in the concave portion is suppressed and lowered.
On the other hand, since the layer thickness of the toner transferred to the convex portion of the fixing sheet in the halftone portion is thin, the shear force applied to each toner particle is larger than that in the solid black portion where the toner layer thickness is thick, and the offset phenomenon. Tends to occur and tends to be a low-quality fixed image. That is, improvement in fixing performance and improvement in hot offset resistance are required.

In order to achieve both the fixing performance and the anti-hot offset performance, various researches have been conducted up to now, focusing on binder resins.
For example, in a chromatograph measured by gel permeation chromatography, a molecular weight showing at least one maximum value in each of a region having a molecular weight of 10 ^{3 to} 7 × 10 ^{4 and} a region having a molecular weight of 10 ⁵ to 2 × 10 ^6. A technique of using a resin having a distribution for toner has been proposed (see, for example, Patent Document 3).
In addition, a technique has been proposed that uses a composition in which a release agent such as polyethylene is contained in a vinyl copolymer having a defined molecular weight distribution as a toner to achieve both fixability and hot offset (for example, patents). References 4 and 5).
Alternatively, a technique for improving the low-temperature fixability and hot offset resistance of toner has been proposed by combining two types of styrene-acrylic copolymer low-viscosity resin and high-viscosity resin (see, for example, Patent Document 6). .)

  However, any of the techniques of Patent Documents 3 to 6 described above is still insufficient for achieving both high fixing performance and anti-hot offset performance in order to obtain high image quality by reducing the toner particle size. Furthermore, it is necessary to satisfy both the fixing performance and the hot offset resistance as well as the heat resistant storage stability.

  In order to optimize such a balance of conflicting heat-resistant storage stability, fixability, and hot offset resistance, a technique for improving the toner performance by broadening the molecular weight distribution of the binder resin has been proposed (for example, Patent Documents). See 7-12.).

According to the above technology, low-temperature fixing and heat-resistant storage stability are improved mainly by the effect of molecular weight distribution and the effect of low molecular weight olefins. However, as a binder resin for toners suitable for recent energy saving and low power consumption, It is not sufficient yet, and further performance improvement is desired.
In particular, in order to improve the low-temperature fixability, it is required to lower the glass transition point (Tg) and molecular weight of the binder resin, but all of these are satisfied considering the balance of hot offset resistance and heat-resistant storage stability. Toner development is difficult.

  Further, a dry toner having a practical sphericity of 0.90 to 1.00, comprising a polyester (i) in which a toner binder is modified with a urethane bond in order to improve fluidity, low temperature fixability, and hot offset. Techniques related to are proposed. This dry toner is excellent in powder flowability and transferability when it is made into a small particle size toner, and is excellent in all of heat-resistant storage stability, low-temperature fixability, and hot offset resistance, particularly a full-color copier. It is described that the toner is a dry toner that is excellent in image glossiness and does not require oil application to a hot roll (see, for example, Patent Document 13).

In addition, a technique for improving powder fluidity, heat-resistant storage stability, low-temperature fixability, and hot offset resistance in the case of a toner having a small particle diameter has been proposed (see, for example, Patent Documents 14 and 15).
For example, in Patent Document 14, as a method for economically obtaining the dry toner as described above, a dry toner comprising a toner binder obtained by subjecting an isocyanate group-containing prepolymer (A) to an extension reaction and / or a crosslinking reaction, and a colorant. Have proposed a dry toner comprising particles formed by an extension reaction and / or a crosslinking reaction with amines (B) in the aqueous medium (A), and a method for producing the same. Patent Document 15 proposes a dry toner composed of a toner binder composed of a high molecular weight resin (A) and a low molecular weight resin (B) composed of a condensation resin, each of which defines a ratio between the SP value and the molecular weight. Has been.

However, the technique described in Patent Document 13 produces a new feature and effect in that a urethane reaction is used as a binder, but it is a pulverization method and has a sufficiently low-temperature fixing toner in terms of fixability. Absent. Further, specific conditions for small particle size and spherical shape control are not included.
In addition, the techniques described in Patent Documents 14 and 15 form a toner by a production method by underwater granulation. When particles are formed in water, the pigment in the oil phase aggregates at the interface of the aqueous phase and the pigment is formed. It causes non-uniformity and a decrease in volume resistance, and causes a problem with toner performance.
In addition, it is required to achieve oillessness, and to achieve shape control at the same time with a small particle size, and for use on machines, predetermined shapes and characteristics are well established as characteristic values. Otherwise, it cannot be used practically. Since such specific characteristic values are not described in the respective patent documents, it is difficult to exert an effect on the problem.
In particular, toner particles formed by underwater granulation tend to have a release agent such as pigment or wax on the toner surface, and when the particle size is about 6 μm or less, the specific surface area of the toner particles is large and the polymer design is high. Other particle surface design is important in obtaining desired charging characteristics and fixing characteristics.

  As described above, when the toner mass adhered to and accumulated on the cleaning member, for example, the cleaning roller is re-melted and reversely transferred to the recording medium, the toner was dissolved in the cleaning roller, and the conventional pulverized toner (pigment, wax, In the case of a uniform dispersion of resin), there was no problem of dissolution even when the fixing unit was rotated by controlling the heater without passing the recording paper while the toner adhered to the cleaning roller. This is because the glass transition point (Tg) of a resin used as a binder for a conventional pulverized toner is relatively high, and a resin having a Tg of around 60 ° C. is used. That is, the viscosity of the toner that adheres to the cleaning roller when it is cleaned is maintained high, and even if the temperature of the cleaning roller rises as the number of copies increases, it is difficult to melt. In addition, since the adhered toner is uniform, the melting temperature of the toner before and after the fixing process does not change.

On the other hand, when a polymerized toner, for example, a toner having a urea-reacted particle structure as described in Patent Document 15 is used, heat is required to dissolve the polymer resin in the outer shell during fixing. Once the toner has undergone the fixing process, the temperature characteristic of the low molecular weight resin that melts at a relatively low temperature is dominant, and the toner tends to melt at a temperature lower than the fixing set temperature. For this reason, when the fixing unit is rotated by controlling the heater without passing the recording paper while the toner is attached to the cleaning roller described above, the toner collected on the cleaning roller is melted and the pressure roller or Reattaches to the fixing roller. When an image is output in this state, there has been a problem that the melted toner adheres to the recording paper and stains the front and back of the recording paper.
The above particle structure can use a low Tg resin as a means for achieving low-temperature fixability compared to pulverized toner, and can achieve both heat-resistant storage stability and low-temperature fixability even when a low molecular weight resin is used. A very advantageous toner particle structure. However, since the glass transition point of the toner is about 5 to 15 ° C. lower than that of the pulverized toner, the toner adhering to the cleaning roller is melted by the heat of the fixing roller during copying and is in a state of being reversely transferred to the fixing roller.

JP-A-9-325550 JP 2002-123119 A Japanese Patent Laid-Open No. 5-107803 Japanese Patent Laid-Open No. 5-289399 JP-A-5-313413 JP-A-5-297630 Japanese Patent Laid-Open No. 5-053722 Japanese Patent Laid-Open No. 5-289399 JP-A-5-313413 JP-A-6-027733 JP-A-6-074426 JP-A-6-118702 Japanese Patent Laid-Open No. 11-133665 JP-A-11-149180 JP 2000-292981 A

The present invention has been made in view of the above prior art, and includes an image forming method for solving the following first to fourth objects, a dry toner for developing an electrostatic image (hereinafter abbreviated as toner), and the toner. It is an object of the present invention to provide a process cartridge in which a cartridge is stored and an electrophotographic apparatus in which the process cartridge is mounted. The toner used in the present invention is a toner having a reduced particle size obtained by polymerization, and the toner can be used alone or as a two-component developer composed of a toner and a carrier. .
The first object is to prevent reverse transfer to the recording medium due to the dissolution of the toner adhering to the cleaning member via the heating member and / or the pressure member of the heat fixing device used in the fixing step of the image forming step. However, stable fixing is possible.
The second object of the present invention is to enable good fixing immediately after power-on while preventing wasteful consumption of energy, and to realize good low-temperature fixability even at low power capacity.
The third purpose is to provide a wide range of reversal prevention from low speed to high-speed image forming devices, and to achieve high image quality by balancing hot-offset resistance, heat-resistant storage and fluidity in a well-balanced manner. Make it possible.
The fourth object is to enable high-definition image formation without fogging, high image density, excellent resolution, and low-speed to high-speed image forming apparatuses.

  As a result of intensive studies, the present inventors have found that when forming an image using a toner having a reduced particle size obtained by polymerization, the first binder resin and the second binder are used as a binder resin for the toner composition. We have found that the above-mentioned problems can be solved by suitably selecting resins and adjusting their solubility and content in THF, as well as selecting the release agent and its dispersion state or content. The present invention has been reached. Hereinafter, the present invention will be specifically described.

That is, the present invention is an image forming toner used for image formation in which toner attached to a heating member and / or a pressure member in an image fixing step is transferred to a cleaning member and removed.
The toner contains at least a colorant, a release agent, a first binder resin and a second binder resin, and the first binder resin has a glass transition temperature of 30 to 46 ° C. The second binder resin comprises a THF-insoluble component, and its content in the total composition is 5 to 25 wt%. The release agents are dispersed independently from each other in the resin. An image forming toner, wherein the content in the total composition is 2 to 10 wt%.
Here, the weight ratio of the first binder resin to the second binder resin is preferably 70/30 to 90/10.

In any one of the image forming methods, the weight average particle size (Dv) in the particle size distribution of the toner measured by the Coulter method is 3.0 to 6.0 μm, and the number average particle size (Dn) is It is preferable that the ratio (Dv / Dn) satisfies the following formula (1).
1.00 ≦ Dv / Dn ≦ 1.20 (1)

  Here, the content of particles of 8 μm or more in the particle size distribution of the toner is preferably 2% or less on a volume basis. The content of particles of 3 μm or less in the particle size distribution of the toner is preferably 5% or less on a volume basis. Further, it is preferable that the particle content of 2 μm or less of the toner measured by a flow type particle image measuring device is 15% or less on the number basis.

  In any of the above image forming methods, it is preferable that the toner has a spindle shape with an average circularity of 0.900 to 0.960 measured by a flow particle image measuring device.

  Furthermore, in any one of the above image forming methods, it is preferable that the release agent is a vegetable wax and the melting point is 40 ° C to 105 ° C.

  According to the present invention, the toner further comprises at least a first binder resin, a compound having an active hydrogen group as a component of the second binder resin, a prepolymer capable of polyaddition reaction with the compound, The dissolved or dispersed dispersion in which a colorant and a release agent are dissolved in an organic solvent is dispersed in an aqueous medium prepared by separately dispersing resin fine particles in water, and the compound is dispersed in the dispersion. The image forming toner according to any one of the above, wherein the toner is formed by performing a polyaddition reaction between the prepolymer and the prepolymer, and then removing the organic solvent from the dispersion.

  In the toner of the present invention, the compound having an active hydrogen group is an amine, and the prepolymer capable of polyaddition reaction with the compound having an active hydrogen group is a polyester prepolymer having an isocyanate group at the terminal, It is preferable that the binder resin is a modified polyester resin modified with a urea bond, and the first binder resin is an unmodified polyester resin not modified with a urea bond.

Further, the present invention comprises a charging process of a photoconductor, a latent image forming process, a developing process using toner, a transfer process, a cleaning process, and a fixing process, and the fixing process is performed between a heating member and a pressure member. In an image forming method comprising a step of fixing a toner image transferred while being conveyed through a recording medium, and a step of transferring the toner adhering to the heating member and / or the pressure member to a cleaning member and removing the toner image.
The image forming method according to the present invention is characterized in that the toner used in the developing step is any one of the image forming toners described above.

Here, it is preferable that the melting temperature (1/2 outflow temperature) at the time of 1/2 outflow measured by a flow tester of the toner transferred to the cleaning member is 120 to 140 ° C.
The melting temperature (1/2 outflow temperature) at the time of 1/2 outflow measured by a flow tester of toner used in the developing step is T1, and the 1/2 outflow temperature of the toner fixed to the cleaning member is T2. In this case, it is preferable to satisfy the relationship of T1 + 10 <T2 (° C.).
In any one of the image forming methods, it is desirable that the value of the viscoelasticity G ′ at 150 ° C. of the toner transferred to the cleaning member is 3000 Pa or more.

  Furthermore, in the image forming method, it is preferable that the photoconductor is an amorphous silicon photoconductor.

  In the image forming method, it is preferable to apply an alternating electric field when developing the latent image on the photoconductor in the latent image forming step.

  In the image forming method, when charging the photosensitive member, it is preferable that a charging member is brought into contact with the photosensitive member and a voltage is applied to the charging member.

The present invention also provides a process cartridge that integrally supports at least one means selected from a photoconductor, a charging means, a developing means containing developer, and a cleaning means, and is detachable from the image forming apparatus main body. The toner used in the developer is a toner described in any one of the above, and relates to a process cartridge.
Furthermore, the present invention relates to an image forming apparatus having the process cartridge mounted thereon.

According to the present invention, the structure of the thermal fixing device used in the fixing process is configured to remove the toner attached to the heating member and / or the pressure member by transferring the toner to the cleaning member and fixing the toner, and the toner to be used The first binder resin and the second binder resin are preferably selected, the solubility and content thereof in THF are adjusted, and the selection of the release agent and its dispersed state or content By adjusting the above, it is possible to prevent the toner transferred to the cleaning member from being melted again and return to the heating member / pressurizing member to be reversely transferred to the recording medium, thereby enabling stable fixing.
In addition, it can be fixed well immediately after the power is turned on, and good low-temperature fixing is possible even at a low power capacity. In addition, it provides a wide range of reversal prevention from low speed to high speed image forming equipment, and also provides a good balance of hot offset resistance, heat storage stability, and fluidity, enabling high image quality. Thus, high-definition image formation with high image density and excellent resolution without fogging is realized.

  In solving the present invention, a conventional fixing process using a heat fixing device configured to fix and remove toner adhered to a heating member and / or a pressure member to a cleaning member is investigated in detail. The above-mentioned object in the present invention was solved while taking into consideration. In the following description, a case where a heating roller is used as a heating member, a pressure roller is used as a pressure member, and a cleaning roller is used as a cleaning member in the heat fixing apparatus will be mainly described.

That is, in normal image output, as shown in the schematic diagram of FIG. 1A, toner adhering to the heating roller 2 from the recording medium (for example, recording paper) due to electrostatic offset or the like is added to the heating roller 2 and added. The image is transferred to the pressure roller 3 at the nip portion where the pressure roller 3 contacts. The toner adhered to the pressure roller 3 is collected by the cleaning roller 4 at the nip portion between the pressure roller 3 and the cleaning roller 4. The toner adhering to the heating roller 2 in such a flow is collected by the cleaning roller 4, and about several grams of toner is collected by the cleaning roller 4 after 150,000 copies. In FIG. 1, 1 is a heater, and 6 is melted toner.
However, in the conventional method, as shown in FIG. 1A, the toner melts from the cleaning roller 4 and the toner moves to the heating roller 2 again. On the other hand, according to the present invention, as shown in the schematic diagram of FIG. 1B, there is no toner dissolution, and high-quality image formation is possible in image output.

FIG. 2 shows a schematic configuration diagram of a more specific fixing device of the schematic diagram shown in FIG.
As shown in FIG. 2, the fixing device 90 includes a heating roller 91 as a fixing rotator incorporating a heater 93 as a heat source, and a pressure roller 92 as a dielectric pressure rotator. The heating roller 91 and the pressure roller 92 are opposed to and in contact with each other across the conveyance path of the paper P, and rotate while being in pressure contact with each other when the heating roller 91 is rotated by a driving motor (not shown). In the fixing device 90, the paper P on which the toner image is formed passes through a fixing nip portion that is a pressure contact portion between the heating roller 91 and the pressure roller 92, and the toner image T is heated by the heater 93. A so-called roller fixing system is adopted in which the toner is heated and fused by applying heat and pressure from the roller 91 to fix the toner image on the paper P.

  The pressure roller 92 is in contact with an aluminum cleaning roller 94. The temperature adjustment of the heating roller 91 is detected by a thermistor 95 installed on the heating roller 91, and is performed by turning on / off the heater installed in the heating roller 91. The temperature of the heating roller 91 is maintained at 160 ° C. to 180 ° C. during standby, and is maintained at 170 ° C. to 190 ° C. during toner fixing on the paper P.

  When the heating roller 91 obtains a recording signal in the standby state, it rotates idly for about 15 seconds until the paper P enters, and heats the pressure roller 92 to about 130 ° C. At this time, the temperature of the cleaning roller 94 rises to about 100 ° C. to 110 ° C. When the temperature rises to this temperature, the minute dirt toner adhering to the surface of the pressure roller 92 due to the electrostatic offset or the minute amount of hot offset moves to the cleaning roller 94 and adheres to the surface of the cleaning roller. As the number of copies increases, the amount of toner to be fixed increases. However, in the past, the cleaning roller 94 could be used without any problem in actual use.

As described above, when the temperature decreases in the order of the heating roller 91, the pressure roller 92, and the cleaning roller 94, and the temperature is equal to or higher than the glass transition point of the toner, the toner offset to the heating roller 91 has its temperature gradient. Accordingly, the pressure roller 92 is sequentially moved to the cleaning roller 94.
Conventionally used pulverized toner is uniform and has a relatively high softening point and Tg. Therefore, there is no major problem that the toner transferred to the cleaning roller 94 is fixed.

However, in the toner required for low-temperature fixing corresponding to the improvement in the number of copies and the reduction in energy consumption as aimed by the present invention, it is necessary to use a material having a low softening point as a binder resin. The softening point of the toner fixed to the cleaning roller 94 has been lowered. For this reason, the toner on the cleaning roller 94 whose temperature has been increased by the heat transmitted from the heating roller 91 to the pressure roller 92 due to the softening point and the decrease in the viscosity is heated and starts to melt.
The toner to be melted is related to the apparent viscosity and the viscoelasticity, and the lower the respective values, the easier it is to melt, and the toner melted on the cleaning roller has a path opposite to the process of fixing to the cleaning roller 94. It moves to the heating roller again and causes a phenomenon of moving to a recording medium (for example, paper) to be copied, resulting in a large quality problem.

  In order to solve the problem, the present inventors investigated the relationship between the characteristics of the toner transferred to the cleaning roller during copying and the melting temperature. That is, first, in the case of a toner for which dissolution did not become a problem in the past, measurement of the viscoelasticity of the toner adhering to the cleaning roller and measurement using a flow tester were performed. As a result, the melting temperature (1/2 outflow temperature) at the time of 1/2 outflow of the toner measured by a flow tester was 120 ° C. or more, and the viscoelasticity was 4000 Pa or more. The viscoelasticity and the 1/2 outflow temperature by the flow tester were determined as follows.

[Measurement method of viscoelasticity]
The viscoelasticity was measured using a HAAKE viscoelasticity measuring instrument under the following conditions.
Rotor: Parallel plate (diameter 20mm)
Toner sample thickness: 2.00 mm (preparing toner pellets with a molding machine)
Temperature subtraction Temperature range: 70 ° C → 220 ° C (measured at 3 ° C / min with 1 minute wait time at 70 ° C)

[Measurement of 1/2 outflow temperature by Fro tester]
An example of the flow tester is an elevated flow tester CFT500D manufactured by Shimadzu Corporation. When the flow behavior of the toner is examined by a temperature raising method under the following measurement conditions using this flow tester, a flow curve shown in FIG. 3A is obtained. Each temperature can be read from the data shown in the figure. In the figure, Ts is the softening temperature, Tfb is the outflow start temperature, and Tend is the outflow end temperature.

<Measurement condition>
Load: 10 kg / cm ² , heating rate: 3.0 ° C./min, die diameter: 0.50 mm, die length: 1.0 mm, starting temperature: 50 ° C., ultimate temperature: 250.0 ° C., preheating time: 200s
<Sample preparation conditions>
A sample weight of 1.00 g is molded to a diameter of 10.0 mm using a flow tester molding machine.

FIG. 3B shows a method of obtaining the melting temperature (1/2 outflow temperature) at the time of 1/2 outflow based on the flow curve of FIG. 3A.
That is, if the difference between the piston stroke (lowest point: Smin) at the outflow start temperature and the piston stroke (Smax) at the outflow end point is 2X, it corresponds to the piston stroke at A corresponding to X = (Smax−Smin) / 2. The melting temperature at the time of 1/2 outflow or the melting temperature in the 1/2 method (T1 / 2 temperature), for short, is defined as the 1/2 outflow temperature.

  On the other hand, as a result of lowering the softening point of the binder resin in order to achieve low temperature fixability and hot offset resistance, the toner adhering to the cleaning roller during copying naturally melted down due to the lowering of the softening point. When the fixing temperature is 160 ° C., the flow tester 1/2 outflow temperature is a minimum of 120 ° C., and 3000 Pa is an appropriate range for the viscoelasticity G ′. When the flow tester 1/2 outflow temperature is 140 ° C. or higher, the toner adheres less to the cleaning roller, but the low temperature fixing temperature rises, so the flow tester 1/2 outflow temperature is kept at 140 ° C.

  In particular, for example, in the case of a toner having a binder resin described in JP-A-11-133665 and JP-A-11-149180 as described above, the glass transition point (Tg) of the polyester resin contained in the toner particles is lowered. The low-temperature fixability was good, but the melting from the cleaning roller of the fixing device deteriorated.

  In addition, the toner that moves to and adheres to the cleaning roller is related to the viscoelasticity of the toner used in the development process, but the toner that adheres to the cleaning roller does not necessarily adhere to the original toner itself. In some cases, a small amount of toner that is not fixed by the toner adheres to the heating roll after adhering to the heating roll, and in some cases it adheres to the heating roll due to general hot offset and then adheres to the cleaning roll. It was.

  Based on the above investigation results, the present inventors have balanced the low-temperature fixing, heat-resistant storage stability, hot-offset resistance, (fluidity), etc., which is the object of the present invention, while utilizing the toner composition having a low-temperature core-shell structure. A toner that can be well achieved and that prevents melting from the cleaning roller and enables high-definition image formation has been realized.

  That is, the present invention was transferred while conveying a recording medium between a heating member and a pressure member, and a charging process of a photoreceptor, a latent image forming process, a developing process using toner, a transfer process, a cleaning process, and a heating member and a pressure member. The above-mentioned object is achieved by suitably selecting and adjusting the composition of the toner used in the developing process of the image forming process composed of the process of fixing the toner image, and reducing the particle size by polymerization. Specifically, the toner to be used contains a first binder resin and a second binder resin as at least a colorant, a release agent, and a binder resin. And 1st binder resin consists of a THF soluble component, and a glass transition point is 30-46 degreeC. The second binder resin is composed of at least a THF-insoluble component and has a content in the total composition of 5 to 25 wt%. Furthermore, the release agent is dispersed in the resin in a dispersed state independently of each other (for example, an island state when observed by TEM), and the content in the total composition is 2 to 10 wt%. It is.

  As will be described later, the second binder resin suitably used in the present invention is a urethane-modified product formed by a polyaddition reaction between a compound having an active hydrogen group and a (polyester) prepolymer having an isocyanate group at the terminal. It is a polyester resin (abbreviated as a modified polyester resin), and the first binder resin is an unmodified polyester resin (abbreviated as an unmodified polyester resin).

  Hereinafter, an image forming method, toner, a process cartridge containing the toner, and an electrophotographic apparatus equipped with the image forming method of the present invention will be sequentially described with reference to the drawings.

  As described above, the first binder resin and the second binder resin are contained as a component of the toner used in the present invention. By combining these two resin components, a toner configuration having a low-temperature core-shell structure and a pseudo capsule shape can be formed, thereby achieving both low-temperature fixability and dissolution from the cleaning roller.

Since the first binder resin is composed of a THF-soluble component and has a glass transition point (Tg) of 30 to 46 ° C., low temperature fixing is possible. Usually, when such a resin having a low glass transition point is used, a toner having a low Tg component adheres to the heating roll, so that the cleaning roller is likely to be melted out, which tends to be a trade-off with so-called low-temperature fixing. Of nature.
However, in the present invention, the following phenomenon has been investigated and analyzed, and even if the first binder resin having a low Tg is used, this can be solved without any problem.

  That is, as a result of examining the toner adhering to the cleaning roller by the present inventors, the adhering toner has remarkably little release agent (for example, wax component) added as a component at the initial stage, and the molecular weight of the adhering toner. When the distribution was measured by GPC, it was found that the polymer-side component of the resin added as the toner component was adhered.

  From this, it is considered that the toner component fixed on the recording medium (for example, paper) is a low molecular component having affinity for paper. Of the toner fixed in the thermal fixing device that fixes the toner image on the recording medium while being conveyed through the recording medium between the heating roller and the pressure roller, a small amount of toner adhering to the heating roller is contained in the particles. Is a toner component that does not contain wax, or a so-called toner component that cannot be fixed.

  In addition, by using the second binder resin that is insoluble in at least THF and has a content in the total composition of 5 to 25 wt% in combination with the first binder resin, the fixing device is cleaned. The toner that moves to and adheres to the roller has high elasticity, and even if the temperature of the cleaning roller rises, the adhered toner becomes difficult to melt. If the amount is less than 5 wt% or more than 25 wt%, the balance with the low-temperature fixability cannot be achieved.

In any case, it is important to consider the following as a condition for preventing melting from the fixing cleaning roller.
(1) Minimize the amount of adhesion to the cleaning roller.
(2) The toner to be fixed is a polymer component of the toner. The polymer component is more difficult to dissolve when a high softening point component or a highly elastic component adheres.
(3) A toner in which a release agent (for example, wax) is uniformly dispersed in the toner particles is difficult to adhere.
(4) The sharper the particle size distribution of the toner, the smaller the amount of toner that adheres to the toner evenly due to the heat being uniformly applied when fixing between the heating roller and the pressure roller.

[Measurement method of glass transition point (Tg)]
The glass transition point (Tg) is measured by the following measuring method.
Apparatus: A TG-DSC system TAS-100 manufactured by Rigaku Corporation is used.
Method: First, about 10 mg of a sample is placed in an aluminum sample container, which is placed on a holder unit and set in an electric furnace. Next, after heating from room temperature to 150 ° C. at a heating rate of 10 ° C./min, the sample is allowed to stand at 150 ° C. for 10 minutes, and then the sample is cooled to room temperature and left for 10 minutes. Further, the DSC measurement is performed by heating again to 150 ° C. at a heating rate of 10 ° C./min under a nitrogen atmosphere. Tg is calculated from the contact point between the tangent line and the base line of the endothermic curve near Tg, using the analysis system in the TAS-100 system.

[Method for measuring THF-insoluble component]
The THF-insoluble component is measured by the following procedure.
(1) Weigh about 1.0 g (A) of toner.
(2) About 50 g of THF (tetrahydrofuran) is added to the weighed toner and allowed to stand at 20 ° C. for 24 hours.
(3) The left THF solution is separated by centrifugation and filtered using a quantitative filter paper.
(4) The solvent content of the obtained filtrate is vacuum-dried, and the residual amount (B) of only the resin content is measured.
The measured residual amount (B) corresponds to the THF-soluble component, and the THF-insoluble component (wt%) is obtained from the following equation.
THF insoluble component (wt%) = (A−B) / A

Further, the state of the release agent used as a component in the toner needs to be dispersed independently of each other, that is, in an island state and uniformly dispersed in the toner particles. The state of the release agent dispersed in the toner particles can be confirmed by observing the toner cross section with the following transmission electron microscope (TEM). The content of the release agent in the total toner composition is preferably 2 to 10 wt% by thermal analysis.
If the dispersion state is not uniform, the amount of adhesion to the heating roller and the amount of adhesion to the cleaning roller will increase, so that various problems will occur such as easiness of melting and deterioration of charging characteristics as a toner. . Further, the effect as a release agent having a content of less than 2 wt% is not exhibited. On the other hand, if the content is more than 10 wt%, the charging characteristics of the toner may be affected.

[Toner cross-section observation by transmission electron microscope (TEM)]
In the present invention, the particle diameter in the maximum direction of the release agent (for example, wax) is defined as the wax dispersion diameter, and the dispersion state is observed. Specifically, the toner is embedded in an epoxy resin, cut into ultra-thin sections of about 100 nm, stained with ruthenium tetroxide, and then observed with a transmission electron microscope (TEM) at a magnification of 10,000 to 50,000 times. Then, the photograph is taken and the photograph is subjected to image evaluation to observe the dispersion state of the wax and measure the dispersion diameter.

  Various waxes and the like described later can be used as the release agent, but the vegetable wax is preferable because it is well-familiar with other components in the present invention and has a suitable release property. Those having a melting point of 40 ° C. to 105 ° C. are suitable for achieving the object in the present invention.

  In the present invention, the weight ratio of the first binder resin to the second binder resin in the toner composition is preferably 70/30 to 90/10. If the weight ratio of the first binder resin to the second binder resin is outside this range, the toner adheres to the cleaning member while maintaining a balance of hot offset resistance, heat resistant storage stability, and low temperature fixability. Removal becomes difficult.

  The toner containing the composition of the present invention is used in the developing step, and the melting temperature (1 /) is measured by a flow tester of the toner fixed to the cleaning member in the fixing step, corresponding to X = (Smax−Smin) / 2. (2 outflow temperature) is preferably 120 to 140 ° C. as described above. By setting it within this range, the low-temperature fixability and the hot offset resistance can be kept good.

  The cleaning member satisfies the relationship of T1 + 10 <T2 (° C.), where T1 is a ½ outflow temperature of toner used in the developing process and T2 is a ½ outflow temperature of toner attached to the cleaning member. Therefore, the toner is not dissolved from the toner. By satisfying these conditions, the balance between the low-temperature fixing property, the hot offset resistance, and the prevention of the dissolution from the cleaning member is kept good.

  Further, by preparing the toner so that the value of the viscoelasticity G ′ at 150 ° C. of the toner attached to the cleaning member is 3000 Pa or more, the temperature of the cleaning member increases with the movement of heat from the heating roll. However, it is possible to prevent the toner from being melted in the cleaning member because the lowering of the viscosity of the toner is suppressed. As the value of the viscoelasticity G 'becomes lower than 3000 Pa, the toner is naturally more likely to be melted, and the tendency to cause the problem of reverse transfer increases.

In the present invention, the toner has a weight average particle diameter (Dv) of 3.0 to 6.0 μm and a ratio (Dv / Dn) to the number average particle diameter (Dn) of 1.00 ≦ Dv / Dn. By satisfying ≦ 1.20, it is possible to obtain a toner that can cope with high resolution and high image quality. Further, by using such a particle size, it is possible to obtain a toner excellent in all of heat-resistant storage stability, low-temperature fixability, and hot offset resistance.
Conventionally, this has been achieved by lowering Tg in order to ensure low-temperature fixability in particular, but there is a limit to lowering Tg because of the relationship with storage stability. In order to solve this problem, the low-temperature fixability was improved by reducing the particle size. The grounds are as follows.

  By reducing the particle size, it is considered that the toner particle packing property of the unfixed image portion is improved, the thermal conductivity when the fixing heater is heated during fixing is improved, and the toner has excellent low-temperature fixability. . That is, by making the particle size small, further low-temperature fixing can be achieved. On the other hand, when a large amount of toner particles of 8 μm or more are contained, not only fixing inhibition occurs due to a decrease in thermal conductivity of the coarse particles, but also the charge amount distribution of the particles becomes wide in the image area, thereby causing development variation and transfer variation. Occurs to cause variations in image density and a decrease in gradation.

Next, particles of 3 μm or less measured by the Coulter method and particles of 2 μm or less measured by the flow type particle image measuring device will be described. The Coulter method and flow-type particle image measurement (similar to the circularity measurement method) will be described later.
In the two-component developer, the balance of the toner is carried out in the developing device of the copying apparatus for a long time. In this balance, the fluctuation of the toner particle diameter in the developer is small, and even in the long-term stirring in the developing apparatus. Good and stable developability is desired. In general, it is said that the smaller the toner particle size, the more advantageous it is to obtain a high-resolution and high-quality image. On the other hand, a toner having a small particle diameter is disadvantageous for transferability and blade cleaning property.

  The reason for this is that, in the case of a toner having a small particle diameter, the adhesion is increased by increasing the chargeability and the specific surface area of the toner particles, and the adhesion to the carrier and adhesion to the photoconductor are increased. Then, the toner is fused to the surface of the carrier during a long period of stirring in the developing device, thereby causing a problem of reducing the charging ability of the carrier.

  With regard to blade cleaning properties, toner with a smaller particle size is less likely to be scraped, and untransferred toner on the photoconductor tends to cause soiling. These phenomena are greatly related to the particle size distribution of around 3 μm. In particular, as the number of particles of 3 μm or less increases, the transferability and blade cleaning properties decrease. The phenomenon that the untransferred toner increases increases. This phenomenon hinders charging stability at a high level.

In order to maintain high image quality and long-term cleaning and durability, it is necessary to suppress the toner shape and the content of particles of 2 μm or less measured by a flow type particle image analyzer.
In particular, long-term stirring of the toner and the carrier in the developing device causes the toner to be fused to the surface of the carrier, thereby reducing the charging ability of the carrier and causing the toner to be fused to a member such as a blade. In addition, untransferred toner remains on the photoconductor, leading to the occurrence of background smudges on the image. In order to prevent this, it has become clear that it is effective that the number-based circle equivalent diameter measured by a flow type particle image analyzer is less than 15% by number of particles having a diameter less than 2.0 μm.

  The average particle size and particle size distribution of the toner were measured by a Coulter counter method. That is, as a particle size distribution measuring device for toner particles, there are Coulter Counter TA-II and Coulter Multisizer IIe (both manufactured by Coulter, Inc.). In the present invention, Coulter Counter TA-II type is used. In addition, an interface (Nichiken Giken) that outputs number distribution and volume distribution and a PC 9801 personal computer (manufactured by NEC) are connected and measured. The specific measurement method is as follows.

[Measurement method by Coulter method]
First, 0.1 to 5 ml of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant to 100 to 150 ml of an aqueous electrolytic solution. The electrolytic solution used here is prepared in a 1% NaCl aqueous solution using primary sodium chloride. As such an electrolytic solution, for example, ISOTON-II (manufactured by Coulter) can be used.
After adding a surfactant to the electrolytic aqueous solution, 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes. By measuring the volume and number of toner particles or toner with this measuring apparatus using a 100 μm aperture, the volume distribution and the number distribution are calculated.

  The channel in the above measurement is as follows: 2.00 to less than 2.52 μm; 2.52 to less than 3.17 μm; 3.17 to less than 4.00 μm; 4.00 to less than 5.04 μm; 5.04 to 6.35 μm Less than 6.35 to less than 8.00 μm; less than 8.00 to less than 10.08 μm; less than 10.08 to less than 12.70 μm; less than 12.70 to less than 16.00 μm; less than 16.00 to less than 20.20 μm; Use less than ˜25.40 μm; 25.40 to less than 32.00 μm; 13 channels less than 32.00 to 40.30 μm. That is, particles having a particle size of 2.00 μm or more and less than 40.30 μm are targeted. Thus, the volume-based weight average particle diameter (Dv) obtained from the volume distribution and the number average particle diameter (Dn) obtained from the number distribution are obtained. Then, a ratio Dv / Dn between the volume-based weight average particle diameter (Dv) and the number average particle diameter (Dn) is obtained.

The average circularity of the toner in the present invention is 0.900 to 0.960, and it is important to have a specific shape (spindle shape) and a distribution in the shape.
With the irregular shape toner of the present invention having an average circularity of less than 0.900, satisfactory transferability and high-quality images without dust cannot be obtained. The irregularly shaped particles have many points of contact with a smooth medium such as a photoconductor, and the electric charge concentrates on the tip of the protrusion, so that the van der Waals force and the mirror image force are higher than those of a relatively spherical particle. For this reason, in the electrostatic transfer process, the spherical particles are selectively moved in the toner in which the amorphous particles and the spherical particles are mixed, and the character portion and the line portion image are lost. In addition, the remaining toner must be removed for the next development process, and there is a problem that a cleaner device is necessary or the toner yield, that is, the ratio of toner used for image formation is low. Arise. Generally, the average circularity of pulverized toner is usually 0.910 to 0.920 when measured with a flow particle image analyzer.

  As a shape measuring method, an optical detection band method is suitable in which a suspension containing particles is passed through an imaging unit detection band on a flat plate, and a particle image is optically detected and analyzed by a CCD camera. The circularity is a value obtained by dividing the perimeter of an equivalent circle having the same projected area obtained by this method by the perimeter of the actual particle. That is, this value is measured by a flow type particle image analyzer FPIA-2100 (manufactured by Sysmex Corporation) and obtained as an average circularity. The specific measurement method is as follows.

[Measurement method of toner shape and distribution by flow type particle image analyzer]
As a specific measuring method, 100 to 150 ml of water from which impure solids have been previously removed is placed in a container, and a surfactant, preferably alkylbenzene sulfonate, is added as a dispersing agent to the container. Further, about 0.1 to 0.5 g of a sample to be measured is added. The suspension in which the sample is dispersed is subjected to dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the concentration and dispersion of the dispersion are set to 3000 to 10,000 / μl, and the shape and distribution of the toner are measured with the apparatus.

  By the above method, the above-described measurement of fine particles of 2 μm or less can also be performed. That is, the measurement method is the same, and the measurement results of circularity and particle size distribution can be obtained simultaneously. As described above, the particle size analysis is performed using information on the projected area and the perimeter of each particle image obtained by image analysis of the particle image. In the analysis, a circle having the same area as the projected area of the particle image is determined, the diameter of the circle is calculated, the frequency distribution of the particles is calculated based on the result, and the number average based on the number basis and the volume basis The value of the diameter and the volume average diameter are calculated respectively. About 2 micrometers or less, the value which calculated the number% from 0.6 micrometer-2 micrometers is shown.

The toner used in the present invention is, for example, a composition of a first binder resin and a second binder resin that are at least soluble in THF in an organic solvent and have a glass transition point of 30 to 46 ° C. The resin fine particles are separately dispersed in water by dissolving or dispersing the compound having an active hydrogen group, a prepolymer capable of polyaddition reaction with the compound, and further dissolving or dispersing the colorant and the release agent. It is obtained by dispersing in a prepared aqueous medium, subjecting the compound and the prepolymer to a polyaddition reaction in the dispersion, and removing the organic solvent from the dispersion and granulating.
Here, the compound having an active hydrogen group is an amine, the prepolymer capable of polyaddition reaction with a compound having an active hydrogen group is a polyester prepolymer having an isocyanate group at its terminal, and the second binder resin is A modified polyester resin modified with a urethane bond, and an unmodified polyester resin in which the first binder resin is not modified with a urethane bond are preferably used.

By combining two resin components composed of such an unmodified polyester resin and a modified polyester resin, a toner particle structure having a low-temperature core-shell structure and a pseudo capsule shape can be formed. Can be achieved.
Hereinafter, a urethane-modified polyester resin (modified polyester resin) suitable as the second binder resin and a non-urethane-modified polyester resin (unmodified polyester resin) suitable as the first binder resin will be mainly described.

FIG. 4 shows a schematic diagram of the toner particle structure.
In order to obtain the toner particle structure shown in FIG. 4, it is necessary to control the range of Tg and molecular weight of the unmodified polyester resin used. That is, it is important to use a non-modified polyester resin contained in the inside of the particle having a Tg of 30 ° C. to 46 ° C. and a molecular weight of 2000 to 10,000 in terms of number average molecular weight. As described above, the toner particles are composed of a low softening point resin, and the modified polyester resin is dispersed to give the particles elasticity so that the toner has a low-temperature core-shell structure and a pseudo capsule shape. A particle structure can be formed.

  Hereinafter, a urethane-modified polyester resin (modified polyester resin) as a second binder resin formed by polyaddition reaction between a compound having an active hydrogen group and a polyester prepolymer having an isocyanate group at the end will be described.

A specific method for producing the modified polyester resin includes a reaction between a polyester prepolymer (A) having an isocyanate group at the terminal and an amine (B).
As the polyester prepolymer (A) having an isocyanate group at the terminal, a polyester having an active hydrogen group, which is a polycondensate of polyol (PO) and polycarboxylic acid (PC), was further reacted with polyisocyanate (PIC). Things. Examples of the active hydrogen group possessed by the polyester include a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group, and the like. Among these, an alcoholic hydroxyl group is preferable.

  Examples of the polyol (PO) include a diol (DIO) and a trivalent or higher polyol (PO), and (DIO) alone or a mixture of (DIO) and a small amount of (TO) is preferable. Diols (DIO) include alkylene glycols (for example, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycols (for example, , Diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (eg, 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols ( For example, bisphenol A, bisphenol F, bisphenol S and the like; alkylene oxides of the above alicyclic diols (for example, ethylene oxide, propylene oxide, Chi alkylene oxide, etc.) adducts, alkylene oxide of the bisphenols (e.g., ethylene oxide, propylene oxide, and the like butylene oxide, etc.) adducts. Among these, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use. Examples of the trivalent or higher polyol (PO) include 3 to 8 or higher polyhydric aliphatic alcohols (for example, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); (For example, trisphenol PA, phenol novolak, cresol novolak, etc.); alkylene oxide adducts of the above trivalent or higher polyphenols and the like.

  Examples of the polycarboxylic acid (PC) include dicarboxylic acid (DIC) and trivalent or higher polycarboxylic acid (PC). (DIC) alone and a mixture of (DIC) and a small amount of (PC) are preferable. Dicarboxylic acids (DIC) include alkylene dicarboxylic acids (eg, succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acids (eg, maleic acid, fumaric acid, etc.); aromatic dicarboxylic acids (eg, phthalic acid, isophthalic acid, etc.) Acid, terephthalic acid, naphthalenedicarboxylic acid, etc.). Among these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. Examples of the trivalent or higher polycarboxylic acid (PC) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (for example, trimellitic acid and pyromellitic acid). In addition, as polycarboxylic acid (PC), you may make it react with a polyol (PO) using the acid anhydride of the above-mentioned thing, or lower alkyl ester (for example, methyl ester, ethyl ester, isopropyl ester, etc.).

  The ratio of the polyol (PO) and the polycarboxylic acid (PC) is usually 2/1 to 1/1, preferably 1 as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. 5/1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.

  Polyisocyanates (PIC) include aliphatic polyisocyanates (eg, tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethyl caproate); alicyclic polyisocyanates (eg, isophorone diisocyanate, cyclohexyl). Aromatic diisocyanates (eg, tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (eg, α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanurates; Polyisocyanates blocked with phenol derivatives, oximes, caprolactams, etc .; and combinations of two or more of these.

  The ratio of the polyisocyanate (PIC) is usually 5/1 to 1/1, preferably 4 /, as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. 1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5/1, the low-temperature fixability deteriorates. When the equivalent ratio [NCO] / [OH] is less than 1/1, the urea content in the modified polyester becomes low when polyaddition reaction is performed with the amines (B) described later to form a urethane-modified polyester, and hot resistance is reduced. Offset property deteriorates.

  The content of polyisocyanate (PIC) in the polyester prepolymer (A) having an isocyanate group at the terminal is usually 0.5 to 40 wt%, preferably 1 to 30 wt%, more preferably 2 to 20 wt% in the constituent components. It is. If it is less than 0.5 wt%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40 wt%, the low-temperature fixability deteriorates.

  The number of isocyanate groups contained per molecule in the polyester prepolymer (A) having an isocyanate group (at the end) is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1. 8 to 2.5. If it is less than 1 per molecule, the molecular weight of the modified polyester resin formed will be low, and the 1/2 outflow temperature after lab plast milling will decrease.

  As amines (B), diamine (B1), triamine or higher polyamine (B2), amino alcohol (B3), amino mercaptan (B4), amino acid (B5), and amino groups of (B1) to (B5) (B6) etc. that are blocked.

  Examples of the diamine (B1) include aromatic diamines (eg, phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane); alicyclic diamines (eg, 4,4′-diamino-3,3′dimethyldicyclohexyl). Methane, diamine cyclohexane, isophorone diamine, etc.); and aliphatic diamines (eg, ethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.) and the like.

  Examples of the trivalent or higher polyamine (B2) include diethylenetriamine and triethylenetetramine. Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid.

  (B6) obtained by blocking the amino group of (B1) to (B5) (K6) obtained from the amines of (B1) to (B5) and ketones (for example, acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.) Compounds, oxazoline compounds and the like. Among the amines (B), preferred are (B1) and a mixture of (B1) and a small amount of (B2).

  Furthermore, if necessary, the molecular weight of the modified polyester resin can be adjusted using an elongation terminator. Examples of the elongation terminator include monoamines (for example, diethylamine, dibutylamine, butylamine, laurylamine, and the like), and those obtained by blocking them (for example, ketimine compounds).

The ratio of the amines (B) is the equivalent ratio [NCO] / [NCO] of the isocyanate group [NCO] in the polyester prepolymer (A) having an isocyanate group at the terminal and the amino group [NHx] in the amines (B). NHx] is usually 2/1 to 1/2, preferably 1.5 / 1 to 1 / 1.5, and more preferably 1.2 / 1 to 1 / 1.2. Here, in the formula of the amino group [NHx], x is 1 or 2, and the main body is 2.
When [NCO] / [NHx] exceeds 2 or less than 1/2, the molecular weight of the modified polyester resin becomes low, and the hot offset resistance deteriorates.

In the present invention, a modified polyester resin, that is, a urea-modified polyester (abbreviated as UMPE) can be used, but the UMPE may contain a urethane bond as well as a urea bond. The molar ratio of the urea bond content to the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance is deteriorated.
Moreover, the weight average molecular weight of UMPE is 10,000 or more normally, Preferably it is 20,000-10 million, More preferably, it is 30,000-1 million. If it is less than 10,000, the hot offset resistance deteriorates.

  The second binder resin made of the modified polyester resin is used in combination with the first binder resin that is soluble in THF and has a glass transition point of 30 to 46 ° C. As such a first binder resin, it is preferable to use an unmodified polyester resin, that is, a polyester not modified with urea (abbreviated as PE) as described above. For example, the combined use of PE improves the low-temperature fixability and the gloss when used in a full-color device.

Examples of PE include polycondensates synthesized using the same polyol (PO) and polycarboxylic acid (PC) as the polyester component shown in the above UMPE, and preferred are the same as UMPE.
In particular, it is preferable in terms of low-temperature fixability and hot offset resistance that at least a part of UMPE and PE is compatible in the toner. Therefore, it is preferable that the polyester component of UMPE and PE have a similar composition. The weight ratio of UMPE to PE is usually 5/95 to 80/20, preferably 5/95 to 30/70, more preferably 5/95 to 25/75, and particularly preferably 7/93 to 20/80. . When the weight ratio of UMPE is less than 5%, the hot offset resistance is deteriorated, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

  The hydroxyl value (acid value) of PE to be used is usually 1-30, preferably 5-30, particularly preferably 5-20. Since PE has an acid value, it tends to be negatively charged, and further, the affinity between paper and toner is improved during fixing, and the low-temperature fixing property is improved. However, when the acid value exceeds 30, the stability of charging tends to be deteriorated due to environmental fluctuations. In addition, if the acid value of the resin fluctuates during the production of the toner, it leads to “blurring” in the granulation step in the polyaddition reaction, making it difficult to control the emulsification.

As described above, the toner in the present invention has at least a first binder resin, a compound having an active hydrogen group as a component of the second binder resin, and an isocyanate group capable of polyaddition reaction with the compound. In an aqueous medium prepared by dissolving or dispersing a prepolymer having colorant and a release agent (for example, wax) in an organic solvent, and separately dispersing the resin fine particles in water. And after the polyaddition reaction of the compound and the prepolymer in the dispersion, an emulsified dispersion (fine droplets containing an organic solvent, first and second binder resins, a colorant, and wax) It is obtained by removing the organic solvent from
The amines are used as the compound having an active hydrogen group, and a second binder resin is formed by a polyaddition reaction, that is, an extension reaction and a crosslinking reaction, with a prepolymer having an isocyanate group at the terminal.

For example, when the polyester prepolymer (A) having an isocyanate group at the terminal is used, as a method for stably forming a dispersion, each composition of the toner raw material is added to the aqueous medium and shearing force is added. And the like.
The prepolymer (A) and other toner components (hereinafter referred to as toner raw materials), an unmodified polyester resin, a colorant (or colorant masterbatch), a release agent such as wax, and an optional charge The control agent or the like may be mixed when the dispersion is formed in the aqueous medium, but it is more preferable that the toner raw material is mixed in advance and then the mixture is added and dispersed in the aqueous medium.

  As an aqueous medium used for toner production in the present invention, water alone may be used, or a solvent miscible with water may be used in combination. Solvents miscible with water include alcohols (eg, methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (eg, methyl cellosolve), lower ketones (eg, acetone, methyl ethyl ketone, etc.), etc. Is mentioned.

In addition, the dispersion method is not particularly limited, and equipment using a known method such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, or an ultrasonic wave can be applied. Here, in order to make the particle size of the dispersion 2 to 20 μm, a high-speed shearing method is preferable.
When a high-speed shearing disperser is used, the number of rotations is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. Similarly, the dispersion time is not particularly limited, but is usually 0.1 to 5 minutes in the case of a batch method. In general, the temperature during dispersion is preferably 20 ° C. or lower. This is to prevent aggregation of the pigment.

  The amount of the aqueous medium used is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight, based on 100 parts of the toner composition comprising the toner raw material. If the amount is less than 50 parts by weight, the dispersion state of the toner composition is poor, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 2000 parts by weight, it is not economical. Further, the viscosity of the oil phase at this time needs to be 2000 mP · s or more with a B-type viscometer. When the viscosity of the oil phase is less than 2000 mP · s, the pigment particles easily move in the dispersed oil phase and start to aggregate, so that the pigment dispersibility of the toner deteriorates and the volume specific resistance of the toner decreases. If the temperature is not maintained at 15 ° C. or lower even after the pigment is dispersed, the pigment particles tend to aggregate.

  Further, in order to lower the viscosity of the toner composition, an organic solvent in which the polyester prepolymer (A) having an isocyanate group at the terminal or the modified polyester (UMPE) formed by polyaddition reaction is soluble may be used. it can. The use of an organic solvent is preferred in that the particle size distribution becomes sharp. And as the said organic solvent, the thing whose boiling point is less than 100 degreeC is preferable from the point that it is easy to volatilize and is easy to remove.

  Examples of such organic solvents include 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 can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene, and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform, and carbon tetrachloride are preferable. The usage-amount of the organic solvent with respect to 100 parts of polyester prepolymer (A) which has an isocyanate group at the terminal is 0-300 parts normally, Preferably it is 0-100 parts, More preferably, it is 25-70 parts. When an organic solvent is used, the prepolymers (A) and (B) are heated and removed under normal pressure or reduced pressure after elongation and / or crosslinking reaction.

  The elongation and / or cross-linking reaction time is selected depending on the reactivity difference determined by the combination of the isocyanate group structure of the prepolymer (A) and the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 2 hours. 24 hours. The reaction temperature is generally 0 to 150 ° C, preferably 40 to 98 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples of such a catalyst include dibutyltin laurate and dioctyltin laurate.

  When the toner composition is used as a dispersion, a dispersant may be used as necessary. The use of a dispersant is preferable in that the particle size distribution becomes sharp and the dispersion is stable.

The resin fine particles used in the case where the dissolved or dispersed toner raw material is dispersed in an aqueous medium prepared by dispersing resin fine particles in water to form an emulsified dispersion, has a glass transition point (Tg) of 50. It is important that it is -70 degreeC, and it is preferable that a weight average molecular weight is 100,000-300,000.
When the glass transition point is less than 50 ° C., toner blocking is reduced, and when it exceeds 70 ° C., the toner particles are prevented from being softened during fixing.
The resin fine particles adhere to the outermost surface of the toner particles after emulsification and form a toner structure that prevents blocking of the low softening resin contained in the toner particles (see FIG. 4).

  As the resin fine particles, an aqueous dispersion can be formed, and any resin fine particles can be used within the above Tg range. Examples of such resin fine particles include vinyl resins, polyurethane resins, epoxy resins, and polyester resins. Two or more of these resins may be used in combination. Of these, vinyl resins, polyurethane resins, epoxy resins, polyester resins, and combinations thereof are preferred because an aqueous dispersion of fine spherical resin particles is easily obtained.

  Examples of the vinyl resin include polymers obtained by homopolymerization or copolymerization of vinyl monomers. Specific examples include styrene- (meth) acrylic acid ester resins, styrene-butadiene copolymers, (meth) acrylic acid- Acrylic ester polymers, styrene-acrylonitrile copolymers, styrene-maleic anhydride copolymers, styrene- (meth) acrylic acid copolymers, and the like.

  In order to remove the organic solvent from the emulsified dispersion composed of the fine droplet particles containing the organic solvent, the first and second binder resins, the colorant, and the wax, the temperature of the entire system is gradually raised to drop the droplets. A method of completely evaporating and removing the organic solvent therein can be employed. The toner circularity can be controlled by the strength of the liquid agitation before the solvent removal and the solvent removal time. That is, when the solvent is removed slowly, the shape becomes more spherical, which is 0.980 or more in terms of circularity. In addition, when the solvent is removed with strong stirring in a short time, irregularities and irregular shapes are obtained, and the degree of circularity is 0.900 to 0.960.

In the case of the present invention, a toner raw material is dispersed in an aqueous medium, and a polyaddition reaction, that is, an extension reaction and a crosslinking reaction, between a compound having an active hydrogen group (for example, amines) and a polyester prepolymer having an isocyanate group at its terminal. In the solvent removal process, the emulsion prepared by forming the second binder resin by the solvent removal at a temperature of 30 to 50 ° C. while stirring with a strong stirring force (for example, ethyl acetate) By performing the above, it is possible to control the circularity, and it is possible to control the shape in the range of 0.850 to 0.990.
That is, volume shrinkage occurs due to abrupt desolvation of ethyl acetate contained in the emulsified liquid (organic solvent, first and second binder resin, fine droplet particles containing colorant and wax), and granulation. In this case, however, the shape of the particles can be controlled by the stirring force and time. However, the solvent removal treatment time at this time is preferably within 1 hour. When the time is longer than 1 hour, the aggregation of the pigment starts and the volume resistivity of the toner particles decreases.

  As another solvent removal method, the emulsified dispersion is sprayed into a dry atmosphere to completely remove the water-insoluble organic solvent in the droplets to form toner fine particles, and the aqueous dispersant is removed by evaporation. It is also possible to do. As a dry atmosphere in which the emulsified dispersion is sprayed, a gas obtained by heating air, nitrogen, carbon dioxide gas, combustion gas, or the like, in particular, various air currents heated to a temperature equal to or higher than the boiling point of the highest boiling solvent used is generally used. Sufficient quality can be obtained with a short treatment such as spray dryer, belt dryer or rotary kiln.

When the particle size distribution at the time of emulsification dispersion is wide and washing and drying processes are performed while maintaining the particle size distribution, the particle size distribution can be adjusted by classification into a desired particle size distribution.
Moreover, the fine particle portion can be removed in the liquid by a classification operation such as a cyclone, a decanter, or centrifugation. Of course, the classification operation may be performed after drying and obtaining as a powder, but classification in a liquid is preferable in terms of efficiency. The obtained unnecessary fine particles or coarse particles can be returned to the kneading step and used for forming particles. At that time, fine particles or coarse particles may be wet.
The dispersant used is preferably removed from the obtained dispersion as much as possible, but it is preferable to carry out it simultaneously with the classification operation described above.

  In addition, the dried toner powder is mixed with different particles such as charge control fine particles and fluidizing agent fine particles, or fixed or fused on the toner surface by applying a mechanical impact force to the mixed powder. It is possible to prevent detachment of foreign particles from the surface of the resulting composite particles.

  As a specific means for giving mechanical impact force to the mixed powder, a method of applying impact force to the mixture by blades rotating at high speed, the mixture is thrown into a high-speed air stream, accelerated, and particles or composites There is a method of causing particles to collide with an appropriate collision plate. As equipment, Ong mill (manufactured by Hosokawa Micron Co., Ltd.), I-type mill (manufactured by Nippon Pneumatic Co., Ltd.) is modified to reduce the pulverization air pressure, hybridization system (manufactured by Nara Machinery Co., Ltd.), kryptron Examples include a system (manufactured by Kawasaki Heavy Industries, Ltd.) and an automatic mortar.

Next, the release agent contained as a component of the toner used in the present invention will be described. A known wax can be used as a release agent.
Examples of the wax include polyolefin wax (for example, polyethylene wax, polypropylene wax and the like); long chain hydrocarbon (for example, paraffin wax, sazol wax and the like); carbonyl group-containing wax and the like. Of these, carbonyl group-containing waxes are preferred. Examples of the carbonyl group-containing wax include polyalkanoic acid esters (for example, carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1 , 18-octadecanediol distearate, etc.); polyalkanol esters (eg, tristearyl trimellitic acid, distearyl maleate, etc.); polyalkanoic acid amides (eg, ethylenediamine dibehenyl amide); polyalkylamides (eg, Trimellitic acid tristearyl amide, etc.); and dialkyl ketones (eg, distearyl ketone, etc.). Among these carbonyl group-containing waxes, polyalkanoic acid esters are preferred.

  The melting point of the wax of the present invention is usually 40 to 105 ° C, preferably 60 to 90 ° C. A wax having a melting point of less than 40 ° C. has an adverse effect on heat-resistant storage stability, and a wax having a melting point of more than 105 ° C. tends to cause a cold offset at the time of fixing at a low temperature. Further, the melt viscosity of the wax is preferably 5 to 1000 cps (5 to 1000 mPa · s), more preferably 10 to 100 cps (10 to 100 mPa · s) as a measured value at a temperature 20 ° C. higher than the melting point. Waxes exceeding 1000 cps (1000 mPa · s) have a poor effect of improving hot offset resistance and low-temperature fixability. The content of the wax in the toner is usually 1 to 20% by weight, preferably 3 to 10% by weight. In particular, in order to finely disperse the wax in the particles having a small particle size, the content of the wax is preferably maintained at 3 to 7% by weight.

  As the releasing agent, the various waxes described above can be used. As the toner in the present invention, vegetable wax is particularly suitable as described above. That is, it is preferable in terms of compatibility with other components in the present invention and releasability, and those having a melting point of 60 ° C. to 105 ° C. are particularly suitable.

Next, the colorant contained as a component of the toner used in the present invention will be described. Known dyes and pigments can be used as the colorant.
Examples of the colorant used include 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 Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Faise Red, Parachlor Ortho Nitro Aniline red, resource Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol 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 , Thioindigo maroon, oil red, quinacridone red, pyrazolone red, polyazo red, claw Vermilion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), indigo, ultramarine blue, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridiane, emerald green, pigment green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Phthalocyanine Green, Anne Traquinone green, titanium oxide, zinc white, litbon and mixtures thereof can be used. The content of the colorant is usually 1 to 15% by weight, preferably 3 to 10% by weight, based on the toner.

  The colorant used in the present invention can also be used in the form of a masterbatch combined with a resin. As the resin kneaded with the master batch during the production of the master batch, the modified polyester resin or the unmodified polyester resin mentioned above is used, and styrene such as polystyrene, poly p-chlorostyrene, polyvinyl toluene, and the substitution thereof. Polymer: styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-acrylic Ethyl acid copolymer, Styrene-butyl acrylate copolymer, Styrene-octyl acrylate copolymer, Styrene-methyl methacrylate copolymer, Styrene-ethyl methacrylate copolymer, Styrene-butyl methacrylate copolymer , Styrene-α-Chlormetac Methyl formate copolymer, Styrene-acrylonitrile copolymer, Styrene-vinyl methyl ketone copolymer, Styrene-butadiene copolymer, Styrene-isoprene copolymer, Styrene-acrylonitrile-indene copolymer, Styrene-maleic acid Styrene copolymers such as copolymers and styrene-maleic acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane Polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax, etc. Or they can be mixed.

The master batch can be obtained by mixing and kneading a resin for a master batch selected from the above and a colorant under a high shear force. In this case, an organic solvent can be used in order to enhance the interaction between the colorant and the resin for the master batch. In addition, a so-called flushing method, which is a method of mixing and kneading an aqueous paste containing water of a colorant together with a resin and an organic solvent, transferring the colorant to the resin side, and removing moisture and organic solvent components, is also preferably used. According to this method, since the wet cake of the colorant can be used as it is, there is no need to dry it. For mixing and kneading, a high shearing dispersion device such as a three-roll mill is preferably used.
Further, other additives used as necessary as the composition of the toner used in the present invention will be described.

(Charge control agent)
That is, the toner of the present invention may contain a charge control agent as necessary. Known charge control agents can be used. For example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified) Quaternary ammonium salts), alkylamides, phosphorus simple substances or compounds, tungsten simple substances or compounds, fluorine-based activators, salicylic acid metal salts, and metal salts of salicylic acid derivatives. Specifically, Bontron 03 of nigrosine dye, Bontron P-51 of quaternary ammonium salt, Bontron S-34 of metal-containing azo dye, E-82 of oxynaphthoic acid metal complex, E of salicylic acid metal complex -84, phenolic condensate E-89 (above, Orient Chemical Industries), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, Hodogaya Chemical Co., Ltd.), quaternary Copy charge PSY VP2038 of ammonium salt, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (above, manufactured by Hoechst), LRA-901, LR- which is a boron complex 147 (manufactured by Nippon Carlit), copper phthalocyanine, perylene, quinaclide , Azo pigments, sulfonate group, carboxyl group, and polymer compounds having a functional group such as a quaternary ammonium salt.

  The amount of charge control agent used as the toner component is the kind of so-called binder resin composed of the first binder resin and the second binder resin, the presence or absence of other additives used as necessary, Although it is determined by a toner production method including a dispersion method and is not uniquely limited, it is preferably used in a range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. It is done. More preferably, the range of 0.2 to 5 parts by weight is good. When the amount exceeds 10 parts by weight, the chargeability of the toner becomes too high, and the effect as a charge control agent is diminished. As a result, the electrostatic attractive force with the developing roller increases, leading to a decrease in developer fluidity and a decrease in image density. These charge control agents can be melt-kneaded with the master batch and the resin, or may be added when dissolved and dispersed in an organic solvent.

In order to assist fluidity, developability, chargeability and the like of the colored particles obtained by the granulation method, an external additive can be used as necessary. As the external additive, inorganic fine particles can be preferably used.
The primary particle size of such inorganic fine particles is preferably 5 mμ to 2 μm, and particularly preferably 5 mμ to 500 mμ. Moreover, it is preferable that the specific surface area by BET method is 20-500 m < ² > / g. The proportion of the inorganic fine particles used is preferably 0.01 to 5% by weight of the toner, and particularly preferably 0.01 to 2.0% by weight.

  Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, Examples thereof include diatomaceous earth, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride.

  In addition to the above inorganic fine particles, polymer fine particles, for example, polystyrene particles obtained by soap-free emulsion polymerization, suspension polymerization or dispersion polymerization, polymer particles made of methacrylic acid ester or acrylic acid ester copolymer, or silicone, benzoguanamine, Polymer particles comprising a polycondensation system such as nylon or a thermosetting resin can be used.

  Such an external additive, for example, a fluidizing agent, can be prevented from being deteriorated in flow characteristics and charging characteristics even under high humidity by performing surface treatment to increase hydrophobicity. Preferred examples of the surface treatment agent include a silane coupling agent, a silylating agent, a silane coupling agent having a fluorinated alkyl group, an organic titanate coupling agent, an aluminum coupling agent, silicone oil, and modified silicone. Examples include oil.

Further, a cleaning property improving agent for removing the developer after transfer remaining on the photosensitive member or the primary transfer medium can be used as an external additive.
Examples of the cleaning property improver include fatty acid metal salts such as zinc stearate, calcium stearate and stearic acid, or polymer fine particles produced by soap-free emulsion polymerization such as polymethyl methacrylate fine particles and polystyrene fine particles. . The polymer fine particles preferably have a relatively narrow particle size distribution and a volume average particle size of 0.01 to 1 μm.

The toner of the present invention obtained as described above can be used as a one-component magnetic toner that does not use a carrier, or a non-magnetic toner, or it can be used as a two-component developer that uses a carrier. it can.
When the toner of the present invention is used as a two-component developer, it may be used by mixing with a magnetic carrier, and the content ratio of the carrier and the toner in the developer is 1 to 10 weights of toner with respect to 100 parts by weight of the carrier. Part is preferred.

  As the magnetic carrier, conventionally known ones such as iron powder, ferrite powder, magnetite powder, magnetic resin carrier having a particle diameter of about 20 to 200 μm can be used. Examples of the coating material include amino resins such as urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, and epoxy resin. Polyvinyl and polyvinylidene resins such as acrylic resins, polymethyl methacrylate resins, polyacrylonitrile resins, polyvinyl acetate resins, polyvinyl alcohol resins, polyvinyl butyral resins, polystyrene resins and styrene acrylic copolymer resins, Halogenated olefin resins such as vinyl chloride, polyester resins such as polyethylene terephthalate resin and polybutylene terephthalate resin, polycarbonate resins, polyethylene resins, polyvinyl fluoride resins, polyvinylidene fluoride resins, polytrifluoroethylene resins, polyhexa Fluoropropylene resin, copolymer of vinylidene fluoride and acrylic monomer, copolymer of vinylidene fluoride and vinyl fluoride, tetrafluoroethylene and vinylidene fluoride Dorukatan monomer and fluoroterpolymers such as terpolymers of, and silicone resins. Moreover, you may contain electrically conductive powder etc. in coating resin as needed. As the conductive powder, metal powder, carbon black, titanium oxide, tin oxide, zinc oxide or the like can be used. These conductive powders preferably have an average particle diameter of 1 μm or less. When the average particle diameter is larger than 1 μm, it becomes difficult to control electric resistance.

  In the image forming method of the present invention, other matters that are preferably applied will be described. First, among the means used in the image forming process, at least one means selected from a photoconductor, a charging means, a developing means containing a developer, and a cleaning means is integrally supported, and the image forming apparatus main body It is preferable to use a process cartridge which is detachable.

(Process cartridge)
An example of the process cartridge in the present invention is shown in the schematic block diagram of FIG.
In FIG. 5, a process cartridge 500 includes a charging unit 502, a developing unit 503, and a cleaning unit 504 as constituent elements around a photosensitive member 501, and this process cartridge is attached to a main body of an image forming apparatus such as a copying machine or a printer. And detachable. The toner used in the present invention is stored in the developing unit 503 as a two-component developer, for example.

  If the process cartridge is used in the image forming method of the present invention, the image apparatus can be made compact, and simple and steady maintenance work can be performed. Furthermore, it is possible to easily replace the parts and to stabilize the image quality. Also, it is possible to restore the original high-quality image simply by replacing the process cartridge.

If the photoconductor used in the image forming process of a high-speed copying machine or a laser beam printer (LBP) is an amorphous silicon photoconductor, the surface hardness is high, and a long wavelength light such as a semiconductor laser (770 to 800 nm) is used. Therefore, even when high-speed printing is performed using the toner according to the present invention, it is possible to form an image with higher quality and higher definition.
In addition, as the electrophotographic photoreceptor used in the present invention, a conductive support is heated to 50 ° C. to 400 ° C., and a vacuum deposition method, a sputtering method, an ion plating method, a thermal CVD method, An amorphous silicon photoreceptor having a photoconductive layer made of a-Si can be used by a film forming method such as a photo CVD method or a plasma CVD method. Among them, for example, a plasma CVD method, that is, a method in which a source gas is decomposed by direct current, high frequency or microwave glow discharge to form an a-Si deposited film on a support can be preferably used.

Furthermore, if the latent image forming step is performed by applying an alternating electric field, a vibration bias voltage obtained by superimposing an AC voltage on a DC voltage is applied when developing the latent image on the photosensitive member by the developing device. A high-definition image with no image is obtained, and the stability of the image quality is improved.
That is, by applying an oscillating bias voltage in which an AC voltage is superimposed on a DC voltage, the difference between the peak value at which the toner is directed to the photoconductor and the time average value of the bias can be increased. The toner becomes more active, and the toner adheres faithfully to the potential distribution on the latent image surface, thereby improving the roughness and resolution. In addition, since the difference between the peak value of the carrier having a charge opposite to that of the toner and the time average value of the bias toward the photosensitive member can be reduced, the movement of the carrier is reduced, and the background portion of the latent image is reduced. The probability of carriers adhering to the substrate can be greatly reduced.

In the charging process of the photoconductor, if the charging member is brought into contact with the photoconductor and a voltage is applied to the charging member, the amount of ozone is remarkably reduced, so that there is no environmental problem. A quality image can be formed.
As the charging device, for example, roller charging, fur brush charging, magnetic brush charging, or the like can be applied, and can be selected according to a request for providing high image quality.

  In the image forming method according to the present invention, when an image forming apparatus equipped with the process cartridge containing the developer is used, the reversal to the recording medium due to the dissolution of the toner fixed to the cleaning member according to the present invention. Prevents copying and enables stable fixing. In addition, low-temperature fixability, hot offset resistance, heat-resistant storage stability, and fluidity are balanced, and there is no fog, high image density, and high-definition image formation from low speed to high-speed image forming apparatuses. . An example of the image forming apparatus according to the present invention will be described below.

(Image forming device)
In the image forming apparatus according to the present invention, the photosensitive member is rotationally driven at a predetermined peripheral speed. In the rotation process, the photosensitive member is uniformly charged at a predetermined positive or negative potential on its peripheral surface by the charging unit, and then receives image exposure light from an image exposing unit such as slit exposure or laser beam scanning exposure. In this way, electrostatic latent images are sequentially formed on the peripheral surface of the photoreceptor, and the formed electrostatic latent images are then developed with toner by a developing unit. The developed toner image is sequentially transferred by the transfer unit to the transfer material fed from the paper feeding unit between the photoconductor and the transfer unit in synchronization with the rotation of the photoconductor. The transfer material that has received the image transfer is separated from the surface of the photosensitive member, introduced into the image fixing means, and fixed, and printed out as a copy (copy). The surface of the photoconductor after the image transfer is cleaned by removing toner remaining after transfer by a cleaning unit, and after being further neutralized, it is repeatedly used for image formation.

Hereinafter, an example of the image forming apparatus of the present invention will be described with reference to the schematic overall configuration diagram of FIG. The image forming apparatus shown in FIG. 6 contains the toner or developer of the present invention, and includes a thermal fixing device having a configuration shown in FIG.
Reference numeral 100 in the drawing denotes a copying machine main body. The copying machine main body 100 has an image reading device 200 mounted thereon and placed on a sheet bank 300. An automatic document feeder 400 is mounted on the image reading apparatus 200 so as to be opened and closed up and down with the back side as a fulcrum.

  The copying machine main body 100 is provided with a drum-shaped photoreceptor 10 as an image carrier. Around the photoconductor 10, in order of the rotation direction (counterclockwise) A of the photoconductor 10 from the charging device 11 arranged on the left side in the figure, the developing device 12 is on the lower side, the transfer device 13 is on the right side, and the upper side is the upper side. A cleaning device 14 is arranged. Among them, the developing device 12 uses the toner of the present invention as the toner, and attaches the toner using a developing roller to make the electrostatic latent image on the photoreceptor 10 visible.

Further, the transfer device 13 is configured by winding a transfer belt 17 between upper and lower rollers 15 and 16 and pressing the transfer belt 17 against the peripheral surface of the photoconductor 10 at a transfer position B.
In FIG. 6, what is provided on the left side of the charging device 11 and the cleaning device 14 is a toner supply device 20 for supplying new toner to the developing device 12.

  In addition, a sheet conveying apparatus C that conveys a sheet S sent from a sheet cassette 61 (described later) of the sheet bank 300 from below to the stack position via the transfer position B is provided inside the copying machine main body 100. The sheet conveying apparatus C includes a supply path R1, a manual feed path R2, and a sheet conveyance path R.

  In the sheet conveyance path R, a registration roller 21 is provided at an upstream position of the photoconductor 10. Further, a thermal fixing device 22 is provided at a downstream position of the photoconductor 10. Specifically, the heat fixing device 22 described later is provided with a heating roller 30 as a heating member and a pressure roller 32 as a pressure member.

  Further downstream of the heat fixing device 22, a discharge branch claw 34, a discharge roller 35, a first pressure roller 36, a second pressure roller 37, and a waist roller 38 are provided. Further, a discharge stack portion (discharge position) 39 for stacking sheets on which images have been formed is provided at the end.

  The copying machine main body 100 is provided with a switchback device 42 on the right side in the drawing. The switchback device 42 branches from the position of the discharge branch pawl 34 of the sheet conveyance path R and leads to the switchback position 44 including the pair of switchback rollers 43, and again from the switchback position 44, the sheet conveyance path. A sheet conveying apparatus D having a re-conveying path R4 leading to the R registration rollers 21 is provided. The sheet conveying apparatus D includes a plurality of sheet conveying rollers 66 for conveying the sheet.

  A laser writing device 47 is provided on the left side of the developing device 12 in the drawing. The laser writing device 47 is provided with a laser light source (not shown), a scanning polygon mirror 48, a polygon motor 49, a scanning optical system 50 such as an fθ lens, and the like.

  The image reading apparatus 200 is provided with a light source 53, a plurality of mirrors 54, an imaging optical lens 55, an image sensor 56 such as a CCD, and the like. A contact glass 57 is provided on the upper surface.

  The automatic document feeder 400 on the contact glass 57 is provided with a document setting table (not shown) at the document placement position and a document stack table (not shown) at the discharge position. In addition, a sheet conveyance device having a document conveyance path (not shown) that conveys a document sheet from a document setting table to a document stack table through a reading position on the contact glass 57 of the image reading device 200 is provided. The sheet conveying apparatus includes a plurality of unillustrated sheet conveying rollers for conveying the original sheet.

  The sheet bank 300 includes therein a plurality of sheet cassettes 61 for storing sheets S such as sheets and OHP films as recording media. Each sheet cassette 61 is provided with a call roller 62, a supply roller 63, and a separation roller 64, respectively. The above-described supply path R1 leading to the sheet conveyance path R of the apparatus main body 100 is formed on the right side of the multi-stage sheet cassette 61 in the drawing. The supply path R1 is also provided with several sheet transport rollers 66 (sheet transport rotating body) for transporting the sheet.

  The copying machine main body 100 is provided with a manual feed unit 68 on the right side in the drawing. A manual feed tray 67 is provided in the manual feed unit 68 so as to be openable and closable, and includes the above-described manual feed path R <b> 2 that guides the manual sheet set on the manual feed tray 67 to the sheet conveyance path R. Similarly, the manual feed tray 67 is provided with a calling roller 62, a supply roller 63, and a separation roller 64.

  Now, when making a copy using this copying machine, a main switch (not shown) is turned on and a document is set on a document setting table of the automatic document feeder 400. In the case of a book document, the automatic document feeder 400 is opened, a document is set directly on the contact glass 57 of the image reading device 200, and the automatic document feeder 400 is closed and pressed.

  When a start switch (not shown) is pressed, when a document is set on the automatic document feeder 400, the document is moved onto the contact glass 57 through the document conveyance path by the sheet conveyance roller, and then the image reading device 200 is moved. Drives, reads the document content, and discharges it onto the document stacking table. On the other hand, when the document is set directly on the contact glass 57, the image reading apparatus 200 is immediately driven.

  When the image reading apparatus 200 is driven, the image reading apparatus 200 moves the light source 53 along the contact glass 57, reflects light from the light source 53 on the original surface on the contact glass 57, and reflects the reflected light into a plurality of light beams. The light is reflected by a mirror 54, passes through an imaging optical lens 55, is put in an image sensor 56, and the image content is read by the image sensor 56.

  At the same time, the photoconductor 10 is rotated by a photoconductor drive motor (not shown). First, in the illustrated example, the surface is uniformly charged by the charging device 11 using a charging roller, and then the above-described image reading device 200 is used. The laser writing device 47 irradiates a laser beam in accordance with the content of the read document and writes it with the laser writing device 47 to form an electrostatic latent image on the surface of the photosensitive member 10. Visualize the electrostatic latent image.

  At the same time when the start switch is pressed, the sheet S is sent out from the sheet cassette 61 corresponding to the selected size in the plurality of sheet cassettes 61 provided in multiple stages in the sheet bank 300 by the calling roller 62, and the subsequent supply rollers 63. While being separated and conveyed one by one by the separation roller 64, the sheet is put into the supply path R 1, conveyed by the sheet conveyance roller 66 to the sheet conveyance path R, and abutted against the registration roller 21 and stopped. Then, the registration roller 21 is rotated in synchronization with the rotation of the toner image visualized on the photosensitive member 10 described above, and is sent to the right side of the photosensitive member 10.

  Alternatively, the manual feed tray 67 of the manual feed unit 68 is opened, the manual feed sheet set on the manual feed tray 67 is sent out by the calling roller 62, and separated and conveyed one by one by the subsequent supply roller 63 and separation roller 64. The sheet is fed into the manual feed path R2, is conveyed by the sheet conveyance roller 66, is guided to the sheet conveyance path R, and is similarly fed to the right side of the photosensitive member 10 by the registration roller 21 in synchronization with the rotation of the photosensitive member 10.

  Then, the toner image on the photoconductor 10 is transferred to the sheet S fed to the right side of the photoconductor 10 at the transfer position B by the transfer device 13 in the illustrated example to form an image. Residual toner on the photoconductor 10 after image transfer is removed and cleaned by a cleaning device 14, and a residual potential on the photoconductor 10 is removed by a neutralization device (not shown) to prepare for the next image formation starting from the charging device 11. .

  On the other hand, the sheet S after the image transfer is conveyed by the transfer belt 17 and put into the heat fixing device 22 and is conveyed through the heating roller 30 and the pressure roller 32 while applying heat and pressure to the sheet S. Fix the upper toner image. Thereafter, the discharge roller 35, the first pressure roller 36, the second pressure roller 37, and the waist roller 38 are seated on the sheet and discharged onto the discharge stack portion 39 to be stacked there.

  Note that the discharge branch claw 34 is switched when images are transferred to both sides of the sheet. Then, the sheet having the toner image transferred to the surface is transferred from the sheet conveying path R to the reversing path R3, conveyed by the sheet conveying roller 66 to the switchback position 44, and switched back by the switchback roller 43 to be re-conveyed. Inverted in the path R4, transported by the sheet transport roller 66, guided again to the sheet transport path R, and the image is transferred to the back surface of the sheet in the same manner as described above.

FIG. 7 shows an example of a schematic configuration diagram of a heat fixing device including a heating roller and a pressure roller used in the image forming apparatus of the present invention.
As shown in FIG. 7, this is a thermal fixing device that fixes a toner image on a recording medium while being conveyed through the recording medium between the heating roller 31 and the pressure roller 32, and removes the toner adhering to the heating roller 31. A cleaning roller 74 as a member is provided, and a surface pressure (roller load / contact area) applied between the heating roller and the pressure roller is 1.5 × 10 ⁵ Pa or less.

  The cleaning roller 74 is directly pressed against the heating roller 31 or the pressure roller 32 so that the toner adhering to the heating roller 31 or the pressure roller 32 is not fixed to the cleaning roller and removed, but is shown in FIG. Thus, the toner adhering to the pressure roller 32 via the toner removing member 84 pressed against the pressure roller 32 may be fixed to the cleaning roller and removed, or although not shown, the heating roller The toner attached to the heating roller 30 through the toner removing member 84 pressed against the toner 31 may be fixed to the cleaning member 74 and removed.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to this. In addition, all the description of a part shows a weight part.

<Example 1>
Under the following conditions, the raw materials used for the production of the toner particles were synthesized or prepared to produce the toner of Example 1.

<Production Example 1: Synthesis of organic fine particle emulsion and preparation of resin fine particle dispersion (1)>
In a reaction vessel equipped with a stir bar and a thermometer, water 838 parts, sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30, manufactured by Sanyo Chemical Industries), 73 parts of styrene, 92 parts of methacrylic acid, When 130 parts of butyl acrylate and 1 part of ammonium persulfate were added and stirred at 400 rpm for 15 minutes, a white emulsion was obtained. The system was heated to raise the temperature in the system to 75 ° C. and reacted for 5 hours. Further, 30 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 5 hours, and an aqueous vinyl resin (a copolymer of sodium salt of styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate). A dispersion [resin fine particle dispersion (1)] was obtained. When the resin fine particle dispersion (1) was measured by LA-920, the volume average particle diameter was 90 nm. A part of the resin fine particle dispersion (1) was dried to isolate the resin component. The Tg of the resin was 57 ° C., and the weight average molecular weight was 200,000.

<Production Example 2: Preparation of aqueous phase (1)>
Mixing 990 parts of water, 83 parts of [resin fine particle dispersion (1)], 37 parts of 48.5% aqueous solution of dodecyl diphenyl ether disulfonate (Eleminol MON-7: Sanyo Chemical Industries) and 90 parts of ethyl acetate Agitation gave a milky white liquid. This is designated as [aqueous phase (1)].

<Production Example 3: Synthesis of unmodified polyester (a)>
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 724 parts of bisphenol A ethylene oxide 2-mole adduct, 138 parts of terephthalic acid and 138 parts of isophthalic acid were subjected to polycondensation at 210 ° C. for 10 hours under normal pressure. After reacting at a reduced pressure of 10 to 15 mmHg for 5 hours, cooling to 160 ° C., adding 18 parts of phthalic anhydride to this and reacting for 2 hours, polyester (a), not modified with a so-called urethane bond [unmodified polyester (A)] was obtained. This unmodified polyester (a) corresponds to the first binder resin. Tg of unmodified polyester (a) was 42 ° C., MW 28000, peak top 3500, and acid value 15.3.

<Production Example 4: Synthesis of isocyanate group-containing prepolymer (1)>
724 parts of bisphenol A ethylene oxide 2-mole adduct, 274 parts of isophthalic acid, 20 parts of trimellitic anhydride, and 2 parts of dibutyltin oxide are placed in a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, and at normal pressure. The reaction was carried out at 230 ° C. for 8 hours, and further reacted for 5 hours while dehydrating at a reduced pressure of 10 to 15 mmHg, then cooled to 160 ° C., 32 parts of phthalic anhydride was added thereto and reacted for 2 hours. Next, the mixture was cooled to 80 ° C., reacted with 188 parts of isophorone diisocyanate in ethyl acetate for 2 hours, and a polyester prepolymer (1) containing an isocyanate group at the terminal, abbreviated as [isocyanate group-containing prepolymer (1)]. Got.
This isocyanate group-containing prepolymer (1) is a modified polyester (second binder resin) modified with a urethane bond by polyaddition reaction with the following ketimine compound (1) having an active hydrogen group in the granulation process. ).

<Production Example 5: Production of ketimine compound (1)>
In a reaction vessel equipped with a stirring bar and a thermometer, 30 parts of isophoronediamine and 70 parts of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to obtain [ketimine compound (1)].

<Production Example 6: Production of master batch (1)>
1200 parts of water, 540 parts of carbon black (Printex35: manufactured by Dexa) and 1200 parts of a polyester resin (unmodified polyester (b) described in Example 5) were added and mixed with a pressure kneader. The mixture was kneaded with two rolls at 150 ° C. for 30 minutes, rolled and cooled, and pulverized with a pulverizer to obtain [Masterbatch (1)]. Carbon DB used had a DBP oil absorption of 42 ml / 100 mg and a pH of 9.5.

<Production Example 7: Production of pigment / WAX dispersion (1)>
In a container equipped with a stir bar and a thermometer, 378 parts of [unmodified polyester (a)], 55 parts of carnauba wax (WAX), 10 parts of wax dispersant, (styrene / acrylonitrile / N-BMA copolymer) acetic acid 947 parts of ethyl was charged, heated to 80 ° C. with stirring, maintained at 80 ° C. for 5 hours, and then cooled to 30 ° C. in 1 hour. Next, 500 parts of [Masterbatch (1)] and 500 parts of ethyl acetate were placed in a container and mixed for 1 hour to obtain [Raw material solution (1)].
[Raw material solution (1)] 1324 parts are transferred to a container, and using a bead mill (Ultra Visco Mill, manufactured by Imex), liquid feeding speed: 1 kg / hr, disk peripheral speed: 6 m / sec, 0.5 mm zirconia beads The carbon black and WAX were dispersed under the condition of 80% by volume and 3 passes. Next, 1324 parts of a 65% ethyl acetate solution of [unmodified polyester (a)] was added, and the mixture was subjected to 3 passes with a bead mill under the above conditions to obtain [Pigment / WAX dispersion (1)].

(Example of toner production: Toner (1))
(I) Emulsification and solvent removal process:
749 parts of [Pigment / WAX dispersion (1)], 115 parts of [Isocyanate group-containing prepolymer (1)] and 2.9 parts of [Ketimine compound (1)] prepared above were put in a container, respectively. (Made by Special Machine) was mixed for 1 minute at a rotation speed of 5,000 rpm. After mixing, 1000 parts of [Aqueous Phase (1)] was added to the container, and mixed for 5 minutes at 5,000 rpm with Filmix (made by Tokushu Kika) to obtain [Emulsified Slurry (1)]. . The liquid temperature at this time was kept at 20 ° C. ± 2 ° C., and ripened for 3 hours after emulsification. The emulsified particle size was measured with a Coulter Multisizer particle size distribution meter, and the reaction was terminated when it reached a predetermined 4 to 5 μm.
[Emulsified slurry (1)] was put into a container equipped with a stirrer and a thermometer, and stirred at a stirring speed of 5 m / s or more to obtain spindle-shaped toner particles. Thereafter, the solvent was removed at 30 ° C. for 8 hours to obtain [Dispersed slurry (1)].

(B) Cleaning and drying process:
After filtering 100 parts of the above [emulsified slurry (1)] under reduced pressure, the following processes (a) to (d) were carried out to obtain [filter cake (1)].
(A): 100 parts of ion-exchanged water was added to the filter cake filtered under reduced pressure, and the mixture was mixed with a TK homomixer at 12,000 rpm for 10 minutes, followed by filtration.
(B): 100 parts of a 10% sodium hydroxide aqueous solution was added to the filter cake of (a), mixed with a TK homomixer at 12,000 rpm for 30 minutes, and then filtered under reduced pressure.
(C): 100 parts of 10% hydrochloric acid was added to the filter cake of (b), mixed with a TK homomixer at 12,000 rpm for 10 minutes, and then filtered.
(D): 300 parts of ion-exchanged water was added to the filter cake of (c), mixed with a TK homomixer at 12,000 rpm for 10 minutes, and then filtered twice. This obtained [Filter cake (1)].
The filter cake (1) was dried for 48 hours at 45 ° C. with a circulating dryer, and sieved with a mesh of 75 μm mesh [matrix particles (1) as a colored powder].

(C) Preparation of base particles (1) which are colored powders:
Next, 0.25 parts of a charge control agent (Bontron E-84: manufactured by Orient Chemical Co., Ltd.) is added to 100 parts of [matrix particles (1) as a colored powder] obtained above, and a Q-type mixer (Mitsui Mining Co., Ltd.), the peripheral speed of the turbine blades was set to 50 m / sec, and a 2-minute operation-1-minute pause process was performed for 5 cycles. The total processing time was 10 minutes.
Furthermore, 0.5 part of hydrophobic silica (H2000: manufactured by Clariant Japan) was added, the peripheral speed was 15 m / sec, mixing for 30 seconds and resting for 1 minute was performed for 5 cycles, black toner (1), abbreviated. [Toner (1)] was obtained.

The specifications and properties of the obtained [Toner (1)] are shown in Table 1 below.
The binder resin (Tg), the ratio between the first and second binder resins, the release agent (type, melting point), and the toner particle size distribution (Dv, Dn, Dv /) in the evaluation items shown in Table 1. Dn, particle sizes of 3 μm or less and 8 μm or more), toner shape and fine particle content (particle content of 2 μ or less, circularity), toner properties (1/2 outflow temperature T1), toner adhering to the cleaning roller (1/2 outflow temperature T2, T2-T1, viscoelasticity), release agent and toner insoluble component (release agent content, release agent dispersion state, THF insoluble component) in the toner composition The measurement was performed in accordance with the measurement method described in the above embodiment.

  Further, the obtained [Toner (1)] was used to evaluate low-temperature fixability, hot offset resistance, heat-resistant storage, resolution, image density, powder flowability, and occurrence of toner contamination due to toner dissolution. The evaluation results are shown in Table 2 below. Each evaluation method is as follows.

[Test method for toner dissolution]
Toner melting is a mechanism in which the offset toner at the time of fixing is collected by the cleaning roller via the heating roller, but the collected deposit is kneaded by the heat of the heating roller, and begins to melt. A phenomenon that adheres to or contaminates images. As a test method, a melting out endurance run is carried out, and toner is attached to the cleaning roller to check a difference in melting out. The test conditions are as follows.
<Conditions>
Copy machine: RICOH made by RICOH Neo 451,
Fixing unit for evaluation: a fixing device for imgio Neo451 (pressure roller diameter: φ30) manufactured by RICOH,
Run mode: 1to15 interval 30s, 6% chart, 15K / day,
Evaluation: Confirmation of the number of sheets until the image is smeared due to toner dissolution

[Evaluation method of powder flowability]
The bulk density was measured using a powder tester made by Hosokawa Micron. The toner with better fluidity has a higher bulk density. Evaluation was performed in the following four stages.
X: Bulk density is less than 0.25,
Δ: Bulk density is 0.25 to 0.30,
○: Bulk density is 0.30 to 0.35,
A: Bulk density is 0.35 or more

[Low-temperature fixability; Evaluation method for minimum fixing temperature]
A Teflon (registered trademark) roller was used as the heating roller. Using a device in which the fixing unit of the Ricoh Co., Ltd. MF-200 was remodeled, type 6200 paper made by Ricoh was set therein, and a copying test was conducted. The low temperature fixing property was evaluated by setting the heating roll temperature at which the residual ratio of the image density after rubbing the fixed image with a pad to 70% or more was set as the minimum fixing temperature.

[Hot offset property; Evaluation method of hot offset occurrence temperature]
The fixing was evaluated in the same manner as the above-mentioned fixing lower limit temperature, and the presence or absence of hot offset to the fixed image was visually evaluated. The hot offset property was evaluated using the heating roll temperature at which hot offset was generated as the hot offset generation temperature.

[Evaluation of heat-resistant storage stability]
<Measurement instrument>
Needle penetration tester (Nikka Engineering), tapping machine, 30 mL screw vial.
<Storage>
Constant temperature layer <Method>
(1) Collect 10g of toner in a 30ML screw vial,
(2) Apply the toner of (1) to the tapping machine 150 times / 1 minute 35 seconds,
(3) Keep quietly in a constant temperature bath at a predetermined temperature of 50 ° C. for 24 hours,
(4) Take out from the thermostatic chamber after 24 hours and rest for 2 hours.
(5) Drop the needle with a penetration tester and test the penetration. <Criteria>
○: 16 mm or more
Δ: 10 to 15 mm,
×: 10 mm or less

(Evaluation of image density)
<Preparation of developer>
50 parts of toner having a particle diameter of 4 to 6 μm and 950 parts of a silicone resin film carrier (silicon resin: KR250 manufactured by Shin-Etsu Chemical Co., Ltd., core material carrier 100 μm) were shaken in a mixer for 20 minutes to obtain a developer.

<Live-action test>
Using these developers, a copying machine (Imagio Neo450 manufactured by Ricoh) was used, and 10,000 sheets were continuously photographed under a high temperature and high humidity environment (30 ° C./80% RH). The image density and resolving power at the initial stage and after 10,000 actual shots were evaluated by the following evaluation methods.
<Evaluation method / Image density>
The relative density with respect to the copy image of the solid portion having an original density of 1.38 was measured with a Macbeth densitometer to obtain an image density.
(Criteria)
○: Difference between initial density and 10,000-sheet copy density is within 0.10,
Δ: The difference between the initial density and the 10,000-sheet copy density is 0.11 to 0.20,
X: The difference between the initial density and the 10,000-sheet copy density is 0.21 or more.

[Evaluation of resolution]
The resolution is 2.0, 2.2, 2.5, 2.8, 3.2, 3.6, 4.0, 4.5, 5.0, 5. For a line image in which 6, 6.3, and 7.1 lines are arranged at equal intervals, it is evaluated how faithfully the copied image can be reproduced between the lines. That is, the number per 1 mm that can be reproduced is the resolution.
(Criteria)
○: 6.3 pieces / mm or more Δ: 5.0 to 5.6 pieces / mm
×: 4.5 / piece

<Example 2>
In the same manner as in Example 1, except that [Pigment / WAX Dispersion (1)] used in Example 1 was replaced with [Pigment / WAX Dispersion (2)] prepared in Preparation Example 8 below, [Toner ( 2)] was obtained. The specifications and properties of the obtained [Toner (2)] are shown in Table 1 below. In addition, the obtained [Toner (2)] was used to evaluate the results of low temperature fixing property, hot offset property, heat resistant storage property, resolving power, image density, powder fluidity, and toner contamination due to toner dissolution. It is shown in Table 2 below.

<Production Example 8: Production of pigment / WAX dispersion (2)>
Manufacture except that 55 parts of carnauba wax (WAX) was replaced with 85 parts and 10 parts of wax dispersant was replaced with 20 parts in <Production Example 7: Production of pigment / WAX dispersion (1)> in Example 1 above. [Pigment / WAX dispersion (2)] was produced in the same manner as in Example 7.

<Example 3>
In the same manner as in Example 1, except that [Pigment / WAX Dispersion (1)] used in Example 1 was replaced with [Pigment / WAX Dispersion (3)] prepared in Preparation Example 9 below, [Toner ( 3)]. The specifications and properties of the obtained [Toner (3)] are shown in Table 1 below. In addition, the obtained [Toner (3)] was used to evaluate the results of low temperature fixing property, hot offset property, heat resistant storage property, resolving power, image density, powder fluidity, and toner contamination due to toner dissolution. It is shown in Table 2 below.

<Production Example 9: Production of pigment / WAX dispersion (3)>
The same procedure as in Production Example 7 except that 55 parts of carnauba wax (WAX) used in <Production Example 7: Production of Pigment / WAX Dispersion (1)> in Example 1 was replaced with 55 parts of rice wax [ Pigment / WAX dispersion (3)] was produced.

<Example 4>
In the same manner as in Example 1, except that [Pigment / WAX Dispersion (1)] used in Example 1 was replaced by [Pigment / WAX Dispersion (4)] prepared in Preparation Example 10 below, [Toner ( 4)]. The first binder resin is [unmodified polyester (a)]. The specifications and properties of the obtained [Toner (4)] are shown in Table 1 below. In addition, the obtained [Toner (4)] was used to evaluate the results of low temperature fixing property, hot offset property, heat resistant storage property, resolving power, image density, powder fluidity, and toner contamination due to toner dissolution. It is shown in Table 2 below.

<Production Example 10: Production of pigment / WAX dispersion (4)>
The same procedure as in Production Example 7 except that 55 parts of carnauba wax (WAX) used in <Production Example 7: Production of pigment / WAX dispersion (1)> in Example 1 was replaced with 55 parts of candelilla wax. [Pigment / WAX dispersion (4)] was produced.

<Example 5>
[Unmodified polyester (a)] used in Example 1 was replaced with [Unmodified polyester (b)] prepared in Preparation Example 11 below, and [Pigment / WAX dispersion (1)] was prepared in Preparation Example 13 below. [Toner (5)] was obtained in the same manner as in Example 1 except that the [Pigment / WAX dispersion (5)] was used. The specifications and properties of the obtained [Toner (5)] are shown in Table 1 below. In addition, the obtained [Toner (5)] was used to evaluate the results of low-temperature fixability, hot offset property, heat-resistant storage, resolving power, image density, powder fluidity, and toner contamination due to toner dissolution. It is shown in Table 2 below.

<Production Example 11: Synthesis of unmodified polyester (b) (first binder resin)>
In a reaction vessel equipped with a condenser, a stirrer, and a nitrogen introduction tube, 196 parts of bisphenol A propylene oxide 2-mole adduct, 553 parts of bisphenol A ethylene oxide 2-mole adduct, 210 parts of terephthalic acid, 79 parts of adipic acid and dibutyl Add 2 parts of tin oxide, react for 8 hours at 230 ° C. under normal pressure, and further react for 5 hours under reduced pressure of 10 to 15 mmHg, then add 26 parts of trimellitic anhydride into the reaction vessel at 180 ° C. and upper pressure. By reacting for 2 hours, [unmodified polyester (b)] was obtained. [Unmodified polyester (b)] had a number average molecular weight of 6,200, a weight average molecular weight of 36,000, Tg of 33 ° C., and an acid value of 15.

<Production Example 12: Production of master batch (2)>
1200 parts of water, 540 parts of carbon black (Regal 400R: manufactured by Cabot) (pH = 4.0), 1200 parts of the modified polyester resin (b) are added and mixed with a pressure kneader, and the mixture is 150 ° C. using two rolls. After kneading for 30 minutes, it was cooled by rolling and pulverized with a pulverizer to obtain [Masterbatch (2)].

<Production Example 13: Production of pigment / WAX dispersion (5)>
In a container in which a stir bar and a thermometer are set, 378 parts of the above [unmodified polyester (b)], 55 parts of carnauba wax, 10 parts of a wax dispersant, ((styrene / acrylonitrile / N-BMA copolymer) ethyl acetate 947 parts were charged, and the temperature was raised to 80 ° C. with stirring, maintained at 80 ° C. for 5 hours, and then cooled to 30 ° C. over 1 hour, and then 500 parts of [Masterbatch (2)] and ethyl acetate 500 1 part was added and mixed for 1 hour to obtain [Raw material solution (2)].
[Raw material solution 2] 1324 parts are transferred to a container, and using a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.), a liquid feeding speed of 1 kg / hr, a disk peripheral speed of 6 m / sec, and 0.5 mm zirconia beads are 80% by volume. Carbon black and WAX were dispersed under conditions of filling and 3 passes. Next, 1324 parts of a 65% ethyl acetate solution of [unmodified polyester b] was added, and the mixture was subjected to 3 passes with a bead mill under the above conditions to obtain [Pigment / WAX Dispersion (5)].

<Comparative example 1>
After warming the 0.1M-Na ₃ PO ₄ aqueous solution 451g to put to 60 ° C. in deionized water 709 g, and stirred at 12,000rpm using a TK homomixer. To this, 68 g of 1.0 M CaCl ₂ aqueous solution was gradually added to obtain an aqueous medium containing Ca ₃ (PO ₄ ) ₂ .
170 g of styrene, 30 g of 2-ethylhexyl acrylate, 3.4 g of ethylene glycol diacrylate, 10 g of legal 400R, 20 g of paraffin wax (sp. 70 ° C.), 5 g of a metal compound of di-tert-butylsalicylate, styrene-methacrylic acid copolymer ( 10 g of Mw 50,000, acid value 20 mgKOH / g) was put into a TK homomixer, heated to 60 ° C., and uniformly dissolved and dispersed at 12,000 rpm. In this, 10 g of a polymerization initiator, 2,2′-azobis (2,4-dimethylvaleronitrile), was dissolved to prepare a polymerizable monomer system.

The polymerizable monomer system was put into the aqueous medium and stirred at 10,000 rpm for 20 minutes in a TK homomixer at 60 ° C. in an N ₂ atmosphere to granulate the polymerizable monomer system. Then, after making it react with a paddle stirring blade for 3 hours at 60 degreeC, liquid temperature was made 80 degreeC and it was made to react for 10 hours. After completion of the polymerization reaction, the mixture was cooled and hydrochloric acid was added to dissolve calcium phosphate, followed by filtration, washing with water and drying to obtain [Toner (Comparative 1)]. The specifications and properties of the obtained [Toner (Comparative 1)] are shown in Table 1 below. Further, the obtained [Toner (Comparative 1)] was used to evaluate the low temperature fixing property, hot offset property, heat resistant storage property, resolving power, image density, powder fluidity, and occurrence of toner contamination due to toner dissolution. Is shown in Table 2 below.

<Comparative example 2>
Under the following conditions, the raw materials used for the production of comparative toner particles were synthesized or prepared to produce a toner (Comparative 2).

<Production Example 14: Preparation of aqueous wax particle dispersion (1)>
A 1000 ml stirrer, temperature sensor, nitrogen inlet tube and four-headed Kolben with cooling tube, 500 ml of degassed distilled water, 28.5 g of New Coal 565C (manufactured by Nippon Emulsifier Co., Ltd.), 1 (manufactured by Noda Wax Co., Ltd.) 185.5 g was added, and the temperature was raised while stirring under a nitrogen stream. When the internal temperature was 85 ° C., a 5N sodium hydroxide aqueous solution was added, and the temperature was raised to 75 ° C. as it was. In this state, heating and stirring were continued for 1 hour, followed by cooling to room temperature, to obtain [Wax Particle Aqueous Dispersion (1)].

<Preparation of Colorant Dispersion (I)>
After adding 100 g of carbon black (trade name: Mogal L, manufactured by Cabot Corporation) and 25 g of sodium dodecyl sulfate to 540 ml of distilled water and sufficiently stirring, a pressure type disperser (MINI-LAB: manufactured by Lani Corporation) was used. Dispersion was performed to obtain [Colorant Dispersion Liquid (I)].

<Production Example 15: Synthesis of high molecular weight and low molecular weight binder fine particle dispersion>
A 1 L 4-head Kolben equipped with a stirrer, cooling tube, temperature sensor and nitrogen inlet tube is 480 ml of distilled water, 0.6 g of sodium dodecyl sulfate, 106.4 g of styrene, 43.2 g of n-butyl acrylate, 10.4 g of methacrylic acid. The mixture was heated to 70 ° C. under a nitrogen stream while stirring. Here, an initiator aqueous solution prepared by dissolving 2.1 g of potassium persulfate in 120 ml of distilled water was added, and the mixture was stirred at 70 ° C. for 3 hours under a nitrogen stream to complete the polymerization. A binder fine particle dispersion (1)] was obtained.
In addition, 5L 4-headed Kolben equipped with a stirrer, cooling pipe, temperature sensor and nitrogen inlet pipe, 2400 ml of distilled water, 2.8 g of sodium dodecyl sulfate, 620 g of styrene, 128 g of n-butyl acrylate, 52 g of methacrylic acid and tert-dodecyl 27.4 g of mercaptan was added, and the temperature was raised to 70 ° C. under a nitrogen stream while stirring. Here, an initiator aqueous solution in which 11.2 g of potassium persulfate was dissolved in 600 ml of distilled water was added, and the mixture was stirred at 70 ° C. for 3 hours under a nitrogen stream to complete the polymerization, and then cooled to room temperature. Molecular weight binder fine particle dispersion (2)] was obtained.

<Production Example 16: Synthesis of Toner (Comparative 2)>
In a 1 L separable flask equipped with a stirrer, a condenser, and a temperature sensor, 47.6 g of [high molecular weight binder fine particle dispersion (1)], [low molecular weight binder fine particle dispersion (2)] 190.5 g, [wax particles 7.7 g of aqueous dispersion (1)], 26.7 g of [colorant dispersion (I)] and 252.5 ml of distilled water were added, mixed and stirred, and then pH = 9 using 5N aqueous sodium hydroxide solution. The adjustment was made to .5. Further, under stirring, a sodium chloride aqueous solution in which 50 g of sodium chloride was dissolved in 600 ml of distilled water, 77 ml of isopropanol and 10 mg of Fluorado FC-170C (manufactured by Sumitomo 3M: Fluoro-based nonionic surfactant) dissolved in 10 ml of distilled water. Aqueous agent aqueous solution was sequentially added, the internal temperature was raised to 85 ° C., the reaction was performed for 6 hours, and then cooled to room temperature. This reaction solution was adjusted to pH = 13 with 5N-aqueous sodium hydroxide solution and then filtered. Further, resuspension was performed in distilled water, filtration and resuspension were repeated, washed, and dried to obtain [Toner (Comparative 2)]. The specifications and properties of the obtained [Toner (Comparative 2)] are shown in Table 1 below. Further, the obtained [Toner (Comparative 2)] was used to evaluate the low-temperature fixing property, hot offset property, heat-resistant storage property, resolving power, image density, powder fluidity, and occurrence of toner contamination due to toner dissolution. Is shown in Table 2 below.

<Comparative Example 3>
[Toner] in the same manner as in Example 1 except that [Pigment / WAX dispersion (1)] used in Example 1 was replaced with [Pigment / WAX dispersion (Comparative 3)] prepared in Preparation Example 17 below. (Comparison 3)] was obtained.

<Production Example 17: Production of pigment / WAX dispersion (Comparative 3)>
In the same manner as in Production Example 7 except that 55 parts of carnauba wax (WAX) used in <Production Example 7: Production of Pigment / WAX Dispersion (1)> in Example 1 was changed to [Pigment / WAX dispersion (Comparative 3)] was produced.

  The specifications and properties of the obtained [Toner (Comparative 3)] are shown in Table 1 below. Further, the obtained [Toner (Comparative 3)] was used to evaluate the low-temperature fixing property, hot offset property, heat-resistant storage property, resolving power, image density, powder fluidity, and occurrence of toner contamination due to toner dissolution. Is shown in Table 2 below.

<Comparative example 4>
[Toner] in the same manner as in Example 1 except that [Pigment / WAX dispersion (1)] used in Example 1 was replaced with [Pigment / WAX dispersion (Comparative 4)] prepared in Preparation Example 18 below. (Comparison 4)] was obtained.

<Production Example 18: Production of pigment / WAX dispersion (Comparative 4)>
The same procedure as in Production Example 7 except that 55 parts of carnauba wax (WAX) used in <Production Example 7: Production of Pigment / WAX Dispersion (1)> in Example 1 was replaced with 55 parts of polypropylene wax. [Pigment / WAX dispersion (Comparative 4)] was obtained.

  The specifications and properties of the obtained [Toner (Comparative 4)] are shown in Table 1 below. Further, the obtained [Toner (Comparison 4)] was used to evaluate the low-temperature fixing property, hot offset property, heat-resistant storage property, resolving power, image density, powder fluidity, and toner contamination due to toner dissolution. Is shown in Table 2 below.

<Comparative Example 5>
(Example of toner production)
In a beaker, 15.4 parts of [isocyanate group-containing prepolymer (1)], 64 parts of [unmodified polyester (b)] and 78.6 parts of ethyl acetate were stirred and dissolved. Next, 20 parts of pentaerythritol tetrabehenate and 10 parts of carbon (REAMAL400R: manufactured by Cabot) were added, and the mixture was stirred at 12,000 rpm with a TK homomixer at 60 ° C., and uniformly dissolved and dispersed. Finally, 2.7 parts of [ketimine compound (1)] used in Example 1 were added and dissolved. This is designated as [toner material solution (1)].

  In a beaker, 706 parts of ion-exchanged water, 294 parts of hydroxyapatite 10% suspension (Superpatite 10: Nippon Chemical Industry Co., Ltd.) and 0.2 part of sodium dodecylbenzenesulfonate were uniformly dissolved. Next, the temperature was raised to 60 ° C., and while stirring at 12,000 rpm with a TK homomixer, [Toner material solution (1)] was added and stirred for 10 minutes. Next, this mixed solution was transferred to a Kolben equipped with a stirrer and a thermometer, heated to 55 ° C., and the solvent was removed under the condition of 25 to 50 mmHg while causing urea reaction, followed by filtration, washing and drying. After that, the wind was classified. Next, 100 parts of toner particles were mixed with 0.5 part of colloidal silica (Aerosil R972: manufactured by Nippon Aerosil) using a sample mill to obtain [Toner (Comparative 5)]. The specifications and properties of the obtained [Toner (Comparative 5)] are shown in Table 1 below. Further, the obtained [Toner (Comparative 5)] was used to evaluate the low temperature fixing property, hot offset property, heat resistant storage property, resolving power, image density, powder fluidity, and occurrence of toner contamination due to toner dissolution. Is shown in Table 2 below.

<Comparative Example 6>
A toner was prepared in the same manner as in Example 1 except that [Non-modified polyester (a)] used in Example 1 was replaced with [Non-modified polyester (d)] produced as follows. [Toner (Comparison 6)] was obtained. The specifications and properties of the obtained [Toner (Comparative 6)] are shown in Table 1 below. In addition, the obtained [Toner (Comparative 6)] was used to evaluate the low-temperature fixing property, hot offset property, heat-resistant storage property, resolving power, image density, powder fluidity, and occurrence of toner contamination due to toner dissolution. Is shown in Table 2.

<Production of comparative unmodified toner binder (4)>
Bisphenol A ethylene oxide 2-mole adduct 325 parts and terephthalic acid 155 parts were polycondensed using 2 parts of dibutyltin oxide as a catalyst to obtain [unmodified polyester (d)]. The Tg of this [unmodified polyester (d)] was 61 ° C. The unmodified polyester (d) corresponds to the first binder resin in the toner composition.

  The specifications and properties of the obtained [Toner (Comparative 6)] are shown in Table 1 below. In addition, the obtained [Toner (Comparison 6)] was used to evaluate the low-temperature fixing property, hot offset property, heat-resistant storage property, resolving power, image density, powder fluidity, and occurrence of toner contamination due to toner dissolution. Is shown in Table 2 below.

  As a result of the above evaluation, according to the image formation using the toner according to the present invention in Examples 1 to 5, no fouling due to melting from the fixing cleaning roller was observed, and low temperature fixability, hot offset resistance, heat resistant storage It was found that the property and fluidity were good, and the resolution and image density of the obtained image were also excellent.

FIG. 10 is a schematic diagram for explaining a state in which toner is melted out in a conventional fixing step (a) and a state in which toner is not melted out in a fixing step of the present invention (b). It is a schematic block diagram which shows the example of a fixing device for demonstrating more specifically the schematic diagram of FIG. It is a figure which shows the method (b) which calculates | requires 1/2 outflow temperature based on the flow curves (a) and (a) which show the flow behavior of the toner obtained by a flotester in this invention. FIG. 3 is a schematic diagram for explaining a particle structure of an image forming toner according to the present invention. It is a schematic block diagram which shows an example of the process cartridge in this invention. 1 is a schematic overall configuration diagram illustrating an example of an image forming apparatus according to the present invention. 1 is a schematic configuration diagram illustrating an example of a heat fixing device including a heating roller and a pressure roller used in an image forming apparatus of the present invention.

Explanation of symbols

1 Heater 2 Heating member (heating roller)
3 Pressure member (Pressure roller)
4 Cleaning member (cleaning roller)
5 Dissolved toner

Claims (19)

An image forming toner used for image formation in which toner attached to a heating member and / or a pressure member in an image fixing process is transferred to a cleaning member to be removed,
The toner contains at least a colorant, a release agent, a first binder resin and a second binder resin, and the first binder resin has a glass transition temperature of 30 to 46 ° C. The second binder resin comprises a THF-insoluble component, and its content in the total composition is 5 to 25 wt%. The release agents are dispersed independently from each other in the resin. A toner for image formation, wherein the content in the total composition is 2 to 10 wt%.   The image forming toner according to claim 1, wherein a weight ratio of the first binder resin to the second binder resin is 70/30 to 90/10. The weight average particle diameter (Dv) in the particle size distribution of the toner measured by the Coulter method is 3.0 to 6.0 μm, and the ratio (Dv / Dn) to the number average particle diameter (Dn) is represented by the following formula ( The image forming toner according to claim 1, wherein 1) is satisfied.
1.00 ≦ Dv / Dn ≦ 1.20 (1)   4. The image forming toner according to claim 3, wherein a particle content of 8 μm or more in the particle size distribution of the toner is 2% or less on a volume basis.   The image forming toner according to claim 3, wherein the content of particles of 3 μm or less in the particle size distribution of the toner is 5% or less on a volume basis.   The image forming toner according to claim 3, wherein the toner has a particle content of 2 μm or less measured by a flow type particle image measuring device of 15% or less on a number basis.   The image forming toner according to claim 1, wherein the toner has a spindle shape with an average circularity of 0.900 to 0.960 as measured by a flow type particle image measuring device.   The image forming toner according to claim 1, wherein the release agent is a vegetable wax and has a melting point of 40 ° C. to 105 ° C.   The toner comprises at least a first binder resin, a compound having an active hydrogen group as a component of the second binder resin, a prepolymer capable of polyaddition reaction with the compound, a colorant, and a release agent. The dissolved or dispersed dispersion in an organic solvent is dispersed in an aqueous medium prepared by separately dispersing resin fine particles in water, and the compound and the prepolymer are overlapped in the dispersion. The image forming toner according to claim 1, wherein the toner is formed by removing an organic solvent from the dispersion after the addition reaction.   The compound having an active hydrogen group is an amine, the prepolymer capable of polyaddition with the compound having an active hydrogen group is a polyester prepolymer having an isocyanate group at the terminal, and the second binder resin is a urea bond. 10. The toner for image formation according to claim 9, wherein the toner is an unmodified polyester resin that is a modified polyester resin that is modified, and the first binder resin is not modified with a urea bond. It consists of a charging process for a photoreceptor, a latent image forming process, a developing process using toner, a transfer process, a cleaning process, and a fixing process. The fixing process is carried while passing a recording medium between a heating member and a pressure member. In the image forming method comprising the step of fixing the transferred toner image and the step of transferring the toner adhering to the heating member and / or the pressure member to the cleaning member and removing the toner,
The image forming method according to claim 1, wherein the toner used in the developing step is the image forming toner according to claim 1.   12. The image forming method according to claim 11, wherein the melting temperature (1/2 outflow temperature) at the time of 1/2 outflow measured by a flow tester of the toner transferred to the cleaning member is 120 to 140 ° C. .   The melting temperature (1/2 outflow temperature) at the time of 1/2 outflow measured by a flow tester for toner used in the developing step is T1, and the 1/2 outflow temperature of the toner fixed to the cleaning member is T2. The image forming method according to claim 12, wherein a relationship of T1 + 10 <T2 (° C.) is satisfied.   The image forming method according to claim 11, wherein the toner transferred to the cleaning member has a viscoelasticity G ′ value at 150 ° C. of 3000 Pa or more.   12. The image forming method according to claim 11, wherein the photoconductor is an amorphous silicon photoconductor.   12. The image forming method according to claim 11, wherein an alternating electric field is applied when developing the latent image on the photosensitive member in the latent image forming step.   12. The image forming method according to claim 11, wherein when charging the photosensitive member, a charging member is brought into contact with the photosensitive member, and a voltage is applied to the charging member.   A process cartridge that integrally supports at least one member selected from a photosensitive member, a charging unit, a developing unit containing developer, and a cleaning unit, and is detachable from the main body of the image forming apparatus; A process cartridge, wherein the toner used in the developer is the toner according to claim 1. 19. An image forming apparatus equipped with a process cartridge, wherein the process cartridge is the process cartridge according to claim 18.

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