JP4984972B2 - Electrostatic latent image developing toner, electrostatic latent image developer, toner cartridge, process cartridge, and image forming apparatus - Google Patents

Description

  The present invention relates to an electrostatic latent image developing toner, an electrostatic latent image developer, a toner cartridge, a process cartridge, and an image forming apparatus.

  Many methods are known as electrophotographic methods (see, for example, Patent Document 1). In general, a latent image is electrically formed on the surface of a photosensitive member (latent image holding member) using a photoconductive substance by various means, and the formed latent image is developed with toner to form a toner image. After the toner image is formed, the toner image is transferred to the surface of a transfer medium such as paper via an intermediate transfer body depending on the configuration, and is fixed by heating, pressurization, heat pressurization, solvent vapor, or the like. Through this, an image is formed. Further, the toner remaining on the surface of the photoreceptor is cleaned by various methods as necessary, and is used again for developing the toner image.

  As a fixing technique for fixing the toner image transferred to the surface of the transfer target, heat to be fixed by inserting the transfer target having the toner image transferred between a pair of rolls composed of a heating roll and a pressure roll. A roll fixing method is common. As a similar technique, a fixing method in which one or both of the rolls is replaced with a belt is also known. Compared with other fixing methods, these techniques provide high-speed and robust images, high energy efficiency, and less environmental damage due to volatilization of solvents and the like.

  The toner image transferred to the surface of the transfer target through the transfer step is melted by being heated by the fixing member heated in the fixing step, and is fixed to the surface of the transfer target. In the fixing step, it is known that the toner image is not fixed unless the fixing member heats not only the toner image but also the transfer target. If the transfer medium is not sufficiently heated, only the toner is melted by the heating from the fixing member, and a so-called cold offset is generated in which the toner adheres to the fixing member.

  Further, when the transfer target or the toner image is excessively heated, the viscosity of the toner is reduced, and so-called hot offset occurs in which part or all of the toner image adheres to the fixing member side. Therefore, as the toner fixing characteristics, a toner having a low cold offset occurrence temperature, a high hot offset occurrence temperature, and a wide fixable region is desirable.

  Along with the increasing demand for power saving and print productivity in recent years, zero or almost no standby power is used in the fixing unit in the printer standby state to save power in the fixing process that occupies a large amount of power consumption. In order to reduce the warm-up time from the standby state, a small heat capacity fixing device is often introduced. When using a fuser with a small heat capacity, the temperature distribution of the fuser tends to increase, so the above fixable area is even more important, and the temperature of the fuser tends to drop due to continuous printing. Therefore, the low-temperature fixability of the toner is also an important characteristic from the viewpoint of print productivity.

  In relation to the fixing characteristics, conventionally, as a binder resin, a polycondensation polyester resin and an addition polymerization styrene acrylic resin are generally used as a binder resin. Since it has high polarity and excellent adhesion to paper, and its melting behavior becomes sharp, it tends to be advantageous for fixing at a lower temperature. Further, even when a fixed image having a higher glossiness is obtained, the polyester resin tends to have better fixability at a lower temperature.

  However, the viscosity adjustment means at a high temperature for raising the hot offset occurrence temperature is not limited to linear and cross-linking, and can be handled with a wide molecular weight and molecular weight distribution control range of several thousand to several hundred thousand. In the case of a resin, it is difficult to increase the molecular weight, and the high molecular weight body tends to be in a gel state, so that the viscosity can be adjusted, but the image glossiness may be insufficient.

  To solve the above problems, a method using a crystalline resin having a sharp sharp melt property as a binder resin for toner has been proposed for a long time as a means for achieving both heat storage properties and fixing properties at low temperatures (for example, (See Patent Documents 2 and 3).

  On the other hand, the design limited to the material side is insufficient to meet the recent demand for energy saving, and improvement from the manufacturing side is strongly desired for further labor saving. The surface property and shape of the toner are important characteristics related to the fluidity and transferability of the toner in the electrophotographic process, and are factors controlled mainly by the toner production method.

  In recent years, a toner production method using an aggregation / unification method has been proposed (see, for example, Patent Documents 4 and 5). In general, resin particle dispersions are prepared by emulsion polymerization, forced emulsification, phase inversion emulsification, etc., and colorant dispersions in which a colorant is dispersed in a solvent are prepared. This is a manufacturing method in which agglomerates are formed and heated to fuse and coalesce into a toner.

  The agglomeration and coalescence method as described above has a wide range of material selection, can easily obtain a toner with a narrow particle size distribution, can easily control the toner shape, and can contain a large amount of a release agent. It is greatly different from the conventional kneading pulverization method in that it is. Considering the recent increase in machine speed and the need for energy saving, it can be said that the agglomeration and coalescence method suitable for the production of a toner having a narrow particle size distribution and a small particle size has excellent characteristics.

On the other hand, a toner produced by the aggregation / unification method using the polyester as a binder resin generally does not always have a satisfactory charging property as compared with the case where the binder resin is a styrene-acrylic copolymer. .
This is presumably because the presence form of the anionic dissociation group on the surface of the emulsified particles is different between the case where the binder resin is a styrene-acrylic copolymer and the case where the resin is a polyester. An emulsion particle produced by an emulsion polymerization method such as a styrene-acrylic copolymer has anionic dissociation groups such as carboxylic acid accumulated on the surface side of the particle due to the characteristics of the production method. For this reason, an anionic dissociation group (carboxyl group etc.) exists in high density on the emulsified particle surface, and it is considered that the particles are stabilized by the sufficient action of these electrostatic repulsive forces. On the other hand, polyester is generally formed by emulsifying particles of a resin solid produced by a polycondensation reaction by a method such as forced emulsification or phase inversion emulsification. For this reason, dispersion | distribution arises in distribution of the anionic dissociation group in particle | grains, and since dissociation group is not accumulate | stored on the surface side, stability may not be enough rather than the case of a styrene-acryl copolymer.

  Further, the aggregation / unification method requires a step of adding an alkali metal salt for the purpose of suppressing particle size growth after the mixture of emulsified particles and other raw materials is aggregated to a desired toner particle size. The addition amount of the alkali metal salt corresponds to the amount required for dissociation of the anionic dissociation group present on the surface side of the particle, but when the amount of the anionic dissociation group on the surface side is insufficient, the anion from the inside of the particle Since it is necessary to promote dissociation of the sex-dissociable group, a large amount of alkali metal salt must be added accordingly. When the amount of the alkali metal salt added is large as described above, the alkali metal remains in the toner in accordance with the input amount, and the charging characteristics are deteriorated.

  For the above reasons, when a toner using a binder resin as a polyester resin by agglomeration and coalescence method is used, the amount of alkali metal salt added to suppress particle size growth increases, resulting in high temperature and high humidity. The electrical (charging) characteristics in the are deteriorated. Therefore, it is necessary to reduce the amount of alkali metal salt itself added or to reduce the residual amount of alkali metal in the toner even when the amount of alkali metal salt added is large in the preparation of wet-process polyester toner. It becomes.

  In view of the above problems, a method has been proposed in which emulsified particles of a polyester resin are produced by agglomeration and coalescence with a relatively small amount of alkali metal salt added (see, for example, Patent Document 6). This method compensates for the deficiency of electrostatic repulsion derived from the carboxyl group of polyester, which is a binder resin, by the steric protection effect of the nonionic surfactant, and can reduce the amount of alkali metal salt added. .

Further, as a method for increasing the amount of carboxylic acid in the toner, a method is proposed in which two types of polyester resins are used in combination with a binder resin, and one of them uses a polyester resin having a high acid value (200 to 500 mgKOH / g). (For example, see Patent Document 8).
Further, as a similar method for incorporating an anionic dissociative group into the toner, a method using a water-soluble polymer as a dispersant has been proposed (see, for example, Patent Documents 9 and 10).

  Further, in the step of aggregating the primary particles containing the binder resin in the aqueous medium and the step of coalescing the aggregated particles, an acrylic acid resin having a volume average molecular weight of 1000 to 90000 or a salt of maleic acid resin A method used in the step of dispersing in the presence of a compound has been proposed (see, for example, Patent Document 11).

Thus, from the recent demand for energy saving, polyester is used as a binder resin, it has a good particle size and particle size distribution, has sufficient electrical properties even under high temperature and high humidity, and has good charging properties. The toner shown is desired.
Japanese Patent Publication No.42-23910 Japanese Patent Publication No. 56-1394 Japanese Examined Patent Publication No.62-39428 Japanese Patent Laid-Open No. 63-282275 JP-A-6-250439 JP 2005-140987 A JP-A-8-234487 JP 2002-40714 A JP-A-62-170971 JP 62-205365 A JP 2006-184306 A

  An object of the present invention is to provide an electrostatic latent image developing toner having good electrical characteristics, an electrostatic latent image developer, a toner cartridge, a process cartridge, and an image forming apparatus.

The above-mentioned subject is achieved by the following present invention.
That is, the invention according to claim 1
A polyester resin, a colorant and a release agent, and a compound satisfying the following (1), (2) and (3):
The content of the compound satisfying the following (1), (2) and (3) is 2.5 to 10% by mass,
The average circularity is in the range of 0.94 to 0.98, the sodium content is in the range of 0 to 0.20 in the net intensity by fluorescent X-ray measurement, and the aluminum content is the net by fluorescent X-ray measurement. The strength is in the range of 0.02 to 0.30, and the water content after being left in an environment of 28 ° C./85% RH for 3 days is 1.5% by mass or less,
In the emulsification step of dispersing each material of the polyester resin, the colorant and the colorant in an aqueous dispersion medium, and a compound satisfying the following (1), (2) and (3) are added to the dispersion of the polyester resin Obtained by mixing the obtained dispersion liquid, an aggregation process for producing aggregated particles from the raw material dispersion obtained by mixing the obtained dispersion liquids, and a fusion process for heating the aggregated particles to obtain toner. A toner for developing an electrostatic latent image.
(1) Acid value ranges from 200 to 500 mgKOH / g
(2) Range of weight average molecular weight of 1500-6500
(3) A polymerizable monomer containing either acrylic acid or maleic acid as the polymerizable monomer constituting the acid component, and containing either styrene or methylstyrene as the other polymerizable monomer A polymer obtained by polymerizing

  The invention according to claim 2 is the electrostatic latent image developing toner according to claim 1, wherein a ½ drop temperature by a flow tester is 85 ° C. or higher and 115 ° C. or lower.

According to a third aspect of the invention, there is provided an electrostatic latent image developer comprising a toner, wherein the toner is the electrostatic latent image developing toner according to the first or second aspect .

The invention according to claim 4 is the electrostatic latent image developer according to claim 3 , which includes a carrier, and the shape factor SF1 of the carrier is in the range of 115 to 140.

According to a fifth aspect of the present invention, there is provided a toner cartridge that contains at least toner, and the toner is the electrostatic latent image developing toner according to the first or second aspect .

According to a sixth aspect of the present invention, there is provided a process cartridge comprising at least a developer holder and containing the electrostatic latent image developer according to the third aspect .

According to a seventh aspect of the present invention, there is provided an image carrier, a developing unit that develops an electrostatic image formed on the image carrier as a toner image with a developer, and a toner image formed on the image carrier. An image forming apparatus comprising: a transfer unit that transfers onto a transfer member; and a fixing unit that fixes a toner image transferred onto the transfer member, wherein the developer is the electrostatic charge image developer according to claim 3. Device.

According to the first aspect of the present invention, it is possible to provide a toner for developing an electrostatic latent image having good charging characteristics and a wide fixable range.
According to the second aspect of the invention, it is possible to provide a toner for developing an electrostatic latent image that can form an image under low-temperature fixing conditions.
According to the first aspect of the present invention, it is possible to provide a toner for developing an electrostatic latent image that has good charging characteristics and can form an image free from image quality defects.
According to the third aspect of the present invention, an electrostatic latent image developer having good charging characteristics can be provided.
According to the invention of claim 4 , it is possible to obtain an electrostatic latent image developer further excellent in durability.
According to the fifth aspect of the present invention, it is possible to facilitate the supply of an electrostatic charge image developing toner having good charging characteristics and to enhance the maintainability of the characteristics.
According to the sixth aspect of the present invention, it is possible to easily handle an electrostatic charge image developer having good charging characteristics and to enhance adaptability to image forming apparatuses having various configurations.
According to the seventh aspect of the invention, it is possible to maintain image formation with a wide fixing temperature range and no image quality defects.

Hereinafter, the present invention will be described in detail.
<Toner for electrostatic latent image development>
The electrostatic latent image developing toner of the present invention has an average circularity (hereinafter referred to as “ shape factor ” for convenience ) in the range of 0.94 to 0.98, and the sodium content is the net intensity measured by fluorescent X-ray measurement. In the range of 0 to 0.20, and the aluminum content is in the range of 0.02 to 0.30 in the net intensity by fluorescent X-ray measurement, and left in an environment of 28 ° C./85% RH for 3 days. The water content after the treatment is 1.5% by mass or less.
However, the electrostatic latent image developing toner of the present invention contains a polyester resin, a colorant and a release agent, and a compound satisfying the following (1), (2) and (3):
The content of the compound satisfying the following (1), (2) and (3) is 2.5 to 10% by mass,
In the emulsification step of dispersing each material of the polyester resin, the colorant and the colorant in an aqueous dispersion medium, and a compound satisfying the following (1), (2) and (3) are added to the dispersion of the polyester resin Obtained by mixing the obtained dispersion liquid, an aggregation process for producing aggregated particles from the raw material dispersion obtained by mixing the obtained dispersion liquids, and a fusion process for heating the aggregated particles to obtain toner. The toner for developing an electrostatic latent image is used.
(1) The acid value is in the range of 200 to 500 mgKOH / g (2) The weight average molecular weight is in the range of 1500 to 6500 (3) As the polymerizable monomer constituting the acid component, either acrylic acid or maleic acid is included. A polymer obtained by polymerizing a polymerizable monomer containing styrene or methylstyrene as another polymerizable monomer .

  The electrostatic latent image developing toner of the present invention (hereinafter sometimes simply referred to as “toner”) will be described in more detail below. First, the features of each invention will be described.

  As described above, in the present invention, the shape factor of the toner is in the range of 0.94 to 0.98, the sodium content is in the range of 0 to 0.20 in the net intensity by fluorescent X-ray measurement, and The aluminum content is in the range of 0.02 to 0.30 in the net intensity measured by fluorescent X-ray measurement.

For example, when sodium is contained in the toner obtained by the aggregation / unification method, sodium takes a salt structure with a polar group such as a carboxyl group in the toner, but is inherently easily ionized, so that R-COONa And R—COO ⁻ + Na ^{+ in} the resin. Therefore, water molecules are likely to exist around sodium ions ionized like Na ⁺ , and as a result, the structure of Na ⁺ further increases.
For this reason, by setting the sodium content in the toner composed of the polyester resin within the range of 0 to 0.20 in the net intensity by the fluorescent X-ray measurement, the hydrophilicity of the polyester resin is suppressed, and in a high humidity environment. However, it is possible to secure excellent chargeability of the toner and maintainability of the charge amount when left, and to provide high image quality with excellent environmental stability.

When the sodium content exceeds 0.20 in the net intensity by fluorescent X-ray measurement, a phenomenon occurs in which the charge amount of the developer decreases according to the number of days left after the stirring in the developing device is stopped due to the operation stop after the output is finished. At the time of re-output, the charge amount is not restored to a sufficient level, so that an image defect such as a ground cover or an abnormal image density occurs. Further, if the sodium content is too low, dissociation of the anionic dissociation group becomes insufficient, and stable granulation control in the aggregation and fusion process may be difficult. If the dissociation is sufficient, there is no problem even if the lower limit of the sodium content is zero.
The sodium content in the toner is more preferably in the range of 0 to 0.15 in the net intensity measured by fluorescent X-ray measurement, and more preferably in the range of 0 to 0.05 in the net intensity.

  On the other hand, aluminum may act as a kind of cross-linking agent for the resin, especially in the case of a resin having a weight average molecular weight of several thousand to several tens of thousands used for toner, because the cohesion between the resin molecules is small, Viscosity drops rapidly at high temperatures. Therefore, an offset in the high temperature region is likely to occur. Therefore, by using aluminum as a cross-linking agent, it is possible to suppress a decrease in viscosity and improve hot offset resistance.

  In the present invention, the aluminum content is in the range of 0.02 to 0.30 in the net intensity by fluorescent X-ray measurement. By setting the aluminum content in the toner to 0.02 or more, the melting curve at the start of melting from the solid before and after the glass transition point maintains the sharp melting characteristics of the original polyester resin, while the toner in the high-temperature part is melted. The decrease in viscosity due to temperature can be moderated, the above-mentioned hot offset occurrence temperature can be increased, and the fixable temperature range can be expanded.

  This is because a kind of ionic cross-linking is generated between aluminum ions and polar parts such as carboxylic acids in the polyester resin molecule, and the same effect as that in which the molecular chain spreads exists in the resin molecule. Therefore, it is considered that a rapid change in melting characteristics of the toner is suppressed. Compared to a polyester resin that simply uses a crosslinking monomer such as trimellitic acid to expand the molecular weight distribution, the mechanism in which the fixable temperature range expands and is advantageous is that the ionic crosslinking mainly acts on the end of the linear molecule, This is considered to be because it is larger than the molecular chain and has a suitable number of crosslinking points.

If the aluminum content exceeds 0.30 in the net intensity measured by fluorescent X-ray measurement, the fixing temperature rises due to excessive rise in melt viscosity.
The aluminum content in the toner is more preferably in the range of 0.05 to 0.30 in terms of net intensity as measured by fluorescent X-ray measurement, and in the range of 0.05 to 0.15 is a color-colored image. It is further desirable to make glossiness appropriate.

The sodium content and the aluminum content can be measured by the following method.
That is, using a fluorescent X-ray analyzer (XRF-1500, manufactured by Shimadzu Corporation), a disk having a toner amount of 0.130 g was molded, and the X-ray output was 40 V-70 mA, the measurement area was 10 mmφ, and the measurement time was 15 minutes. Qualitative quantitative measurement was carried out by the total elemental analysis method, and the strength of NaKα and AlKα in this data was defined as the net strength of the present invention. In addition, when the peak of another element overlaps with this peak, the intensity | strength of a sodium content and an aluminum content can be calculated | required after analyzing by ICP emission spectroscopy or atomic absorption method.

The method for controlling the sodium content can be controlled by, for example, the temporary pH in the emulsion aggregation method. That is, if the pH of the resin particles in the aggregated particles is moderately low, sodium is likely to be released to the outside of the aggregated particles. Conversely, the amphoteric metal aluminum tends to decrease and remain in the ionized amount. Therefore, control becomes possible.
Specifically, for example, in the emulsion aggregation method, aluminum ions are introduced into the toner by being used as an aggregating agent, and the residual amount after toner formation can be adjusted by adding a chelating agent after completion of aggregation. it can.

  The toner of the present invention is required to have a shape factor in the range of 0.94 to 0.98. When the shape factor is less than 0.94, the coalescence of the aggregated particles in the toner manufacturing process becomes insufficient, and the mechanical stress in the developing unit causes the toner particles to be crushed or crushed in the cleaning unit, resulting in image defects. Cause. On the other hand, if it is larger than 0.98, the toner particles have a nearly spherical shape. Therefore, particularly in the case of an image forming method using a blade cleaning method, the toner particles slip through the cleaning unit, and the image due to poor cleaning occurs. White streaks occur.

  In addition, when the toner described later includes a crystalline polyester resin, if the shape factor is smaller than 0.94, the portion where the toner and the carrier cannot be contacted increases and the contact portion becomes excessively charged. The distribution of water becomes wider, and it is easy for fogging to occur. Also, transfer efficiency tends to be insufficient. When the shape factor is larger than 0.98, the area of the contact portion between the toner and the carrier becomes small, and in the above-described re-output, the time for returning to a sufficient charge amount becomes long, and ground fogging occurs.

Therefore, by controlling the shape factor to 0.94 to 0.98, it is possible to provide an image having no image defect, and in particular, in the image forming method using the blade cleaning method, a more remarkable effect can be obtained. In addition, since the contact area between the toner and the carrier can be appropriately controlled, it is easy to return to a sufficient charge amount at the time of the above-mentioned print restart, and the blade cleaning property of the transfer residual toner on the photoconductor, In addition, the toner transfer efficiency can be improved.
The shape factor is preferably in the range of 0.95 to 0.98, and more preferably in the range of 0.96 to 0.98.

The shape factor of the toner can be measured using a flow particle analyzer FPIA2100 (manufactured by Hosokawa Micron). The measurement conditions are as follows.
Pretreatment: Dilute with 300 ml of pure water to 300 mg of stock solution, and disperse for 5 minutes with ultrasound Measurement conditions: mode HPF measurement mode
Analytical amount 0.35μL
Particle count 1500 to 5000 count Analysis condition: particle size limited range 0.60 to 10.05 μm (equivalent circle diameter)
Circularity limited range 0.40 to 1.00

  Further, the shape factor of the toner can be controlled within a necessary range by adjusting the fusing temperature, fusing time, pH during fusing, and the like. Although the above conditions vary depending on the molecular weight of the binder resin, glass transition point, amount of cross-linking material, type of cross-linking material, amount of release agent, melting point of release agent, colorant content, etc. If so, the shape factor can be controlled not to exceed 0.98 by controlling the fusion temperature low and the fusion time short, and vice versa to prevent the shape factor from becoming less than 0.94. It can be controlled by setting the conditions.

  In the present invention, the polyester resin as the binder resin may include a crystalline polyester resin. In this case, it is desirable that the ½ drop temperature (Tf1 / 2) by the flow tester is 85 ° C. or higher and 115 ° C. or lower. .

The softening temperature Tf1 / 2 can be measured using a Koka-type flow tester CFT-500C (manufactured by Shimadzu Corporation). 1 mm length, pressurizing load of 0.98 MPa (10 kg / cm ² ), preheating time of 5 minutes, heating rate of 1 ° C./min, measurement temperature interval of 1 ° C., start temperature of 65 ° C. Below, it was set as the temperature equivalent to 1/2 of the height of the end point from the outflow start point when a 1.05 g sample was melted out.

As described above, in the present invention, it is desirable that the toner contains a compound satisfying the following (1), (2) and (3) in addition to the polyester resin or the like.
(1) The acid value is in the range of 200 to 500 mgKOH / g (2) The weight average molecular weight is in the range of 1500 to 6500 (3) As the polymerizable monomer constituting the acid component, either acrylic acid or maleic acid is included. A polymer obtained by polymerizing a polymerizable monomer containing styrene or methylstyrene as another polymerizable monomer.

As described above, for example, when toner is prepared by agglomeration and coalescence using a polyester resin as a binder resin, the amount of carboxylic acid in the emulsified particles, particularly the amount of carboxyl groups on the surface portion of the particles can be increased. It is effective.
When agglomeration and coalescence method is used for producing wet toner, the mixture of emulsified particles and other raw materials is agglomerated to the desired toner particle size, and then the particle size growth of the toner is stopped to perform fusion and coalescence. As a result, a toner having a sharp particle size distribution can be obtained. In order to obtain a toner having a narrow particle size distribution, it is important to stably control the above aggregation and coalescence process, and the kind and amount of anionic dissociation groups represented by carboxyl groups present on the surface of the emulsified particles It depends heavily.

  In the aqueous dispersion medium, a large number of anionic dissociation groups are present on the surface of the emulsified particles, and the emulsified particles maintain a stable (hard to aggregate) dispersed state by their electrostatic repulsion. When the electrostatic repulsion action by an anionic dissociation group is insufficient, rapid particle size growth occurs in the aggregation process, and it becomes difficult to sufficiently suppress contact between the aggregated particles in the fusion process. On the other hand, when there are many anionic dissociation groups and sufficient electrostatic repulsion acts, rapid particle size growth can be suppressed in the aggregation process, and the emulsified particles are maintained in a well dispersed state in the fusion process. can do. Therefore, it is presumed that the presence of an anionic dissociation group represented by a carboxyl group on the surface of the emulsified particles is important in order to perform stable toner granulation control in the aggregation / unification method.

  However, the presence form of the anionic dissociation group on the surface of the emulsified particles varies greatly depending on the type of the binder resin, the method of preparing the emulsified particles, the operation method in the aggregation / union process, etc. The influence of the manufacturing method is great.

  When the binder resin is an acrylic acid resin such as a styrene-acrylic copolymer, the resin can be prepared by a radical polymerization reaction, and therefore, an emulsion polymerization method is generally used for the resinification. Emulsified particles produced by a technique such as emulsion polymerization tend to accumulate anionic dissociation groups such as carboxyl groups on the surface side of the particles due to the characteristics of the production process. For this reason, since the anionic dissociation groups are present at high density on the surface of the emulsified particles, electrostatic repulsion due to negative charges acts on the emulsified particles, and a stable dispersion state can be maintained. For this reason, when the toner is prepared by agglomeration and coalescence using emulsified particles containing styrene-acrylic copolymer as the main component, stable dispersibility control is possible due to good dispersibility of the emulsified particles. Is

  On the other hand, in the case of a resin having a polyester resin as a main component, since resinification is performed by a polycondensation reaction, a method of emulsifying particles of a resinated resin solid by a method such as forced emulsification or phase inversion emulsification is generally used. Is. For this reason, the distribution of anionic dissociation groups such as carboxyl groups is in a dispersed state within the emulsified particles, and the styrene-acrylic copolymer is the main component because no anionic dissociation groups are accumulated on the surface of the emulsified particles. The dispersion stability is lower than that of the emulsified particles. Therefore, it is insufficient to suppress abrupt particle size growth in the aggregation process and adhesion between the aggregated particles in the fusion process, and stable granulation control is difficult.

  In addition, when focusing on the anionic dissociation group from the viewpoint of the operation method during aggregation and coalescence, in order to impart stability to the emulsified particles and those aggregated particles in the above aggregation and coalescence process, a carboxyl group or the like Since it is necessary to promote the dissociation of the anionic dissociating group, a step of adding an alkali metal salt is required particularly before the fusion step. In general, alkali metals have high hygroscopicity, and therefore, when they remain in the toner, they cause deterioration of electrical characteristics particularly under high temperature and high humidity. For this reason, the addition amount of the alkali metal salt is preferably as small as possible.

  Compared with the case where the emulsified particles are styrene-acrylic resin and the case of polyester resin with respect to the amount of alkali metal salt added in the aggregation / unification step, the polyester resin emulsified particles are emulsified due to the characteristics of the production method as described above. The degree of anionic dissociation group accumulation on the particle surface is insufficient. Therefore, in order to further promote dissociation of the anionic dissociating group, it is necessary to add a larger amount of alkali metal salt. If the amount of the alkali metal salt added is excessive, it will be difficult to remove by the washing step described later, so that a large amount of alkali metal will remain in the toner, resulting in deterioration of electrical characteristics under high temperature and high humidity.

  For the above reasons, it is relatively difficult to stably control the granulation of the emulsified particles of the polyester resin, and image defects such as fogging under high temperature and high humidity are likely to occur. Therefore, in order to improve granulation stability and environmental stability (especially charging characteristics), the density of anionic dissociation groups such as carboxyl groups present on the surface of the polyester emulsified particles is increased, and There is a need to reduce the residual amount of alkali metal present. This point is as described in the first aspect of the present invention.

  As a result of the study by the present inventors on the technical problem of the toner using the emulsified particles of the polyester resin as described above, a large number of anions are not simply increased, but the number of anionic dissociation groups incorporated in the resin skeleton is not increased. It has been found that this can be solved by using a compound having a sex dissociable group as an additive.

  That is, when a compound having a large number of anionic dissociative groups is used as an additive (especially, added during aggregation and coalescence), these compounds are adsorbed on the surface of the polyester emulsified particles. As a result, the surface of the emulsified particles is maintained in a state in which electrostatic repulsion is sufficiently applied, and thus rapid particle growth during aggregation can be suppressed. Moreover, since the electrostatic repulsion effect derived from these anionic dissociation groups acts also in a fusion process, adhesion of aggregated particles can fully be prevented and stable granulation control is attained.

  On the other hand, regarding the addition amount of the alkali metal salt used for the purpose of stopping the particle size growth, the required amount increases in accordance with the amount of the compound having a large number of anionic dissociation groups added. A salt formed by an anionic dissociation group and an alkali metal present in the resin skeleton is in a form in which the alkali metal salt is incorporated into the resin skeleton, so that it is difficult to completely remove the alkali metal by washing. On the other hand, the alkali metal salt formed with the anionic dissociation group in the additive is relatively easy because the alkali metal is removed at the same time that the additive is released from the toner in the toner cleaning. The residual amount of alkali metal in the toner can be reduced.

  Further, it is considered that the alkali metal can be removed by improving the washing process even in the toner having an anionic dissociation group in the resin skeleton. However, in that case, in addition to the complication of resin synthesis, a more complicated cleaning operation is required, which is not preferable from an industrial viewpoint (for example, an increase in the size of a manufacturing apparatus).

  However, for example, as a compound having an anionic dissociation group, an anionic property such as a carboxylic acid that can be imparted to the polyester resin particles even if a toner is prepared by agglomeration and coalescence using a suitable alkylcarboxylic acid. It has been found that it is difficult to reduce the amount of alkali added in the system and the residual amount of alkali metal in the toner due to insufficient dissociation groups or insufficient dispersion stability due to steric hindrance.

  For this reason, as a result of further investigation by the present inventors, a compound having a large number of anionic dissociation groups such as carboxyl groups and having a specific range of acid value and molecular weight was added to the emulsified particles of the polyester resin. Thus, it has been found that if the toner is produced by the aggregation / unification method, stable granulation control can be performed and the residual amount of alkali metal can be reduced.

  As a result, the electrical characteristics can be greatly improved as compared with the conventional toner, and the occurrence of image defects such as fogging under high temperature and high humidity can be suppressed. Further, since the change in melt viscoelasticity of the toner is relaxed in the high temperature range, the offset resistance on the high temperature side is improved, and the fixable temperature range is further expanded. Further, for example, it was found that even when a crystalline polyester resin is used, embedding of the external additive on the toner surface can be reduced, and the durability of the developer can be improved.

Specifically, the acid value is in the range of 200 to 500 mg KOH / g, the weight average molecular weight is in the range of 1500 to 6500, and the acid component includes either acrylic acid or maleic acid, As other components, a compound containing either styrene or methylstyrene (hereinafter sometimes referred to as “high acid value dispersant”) imparts granulation stability to the emulsified particles of the polyester resin, and the electrical properties of the toner. It has been found that there is an effect of improving (charging) characteristics.
Therefore, the toner of the present invention can obtain good charging characteristics by containing the above compound (high acid value dispersant) as a compound having an anionic dissociation group. In addition, from the viewpoint of obtaining better charging characteristics, the toner is prepared by dispersing a resin particle dispersion in which resin particles containing at least a polyester resin are dispersed, and the high acid value dispersant is added to the resin particle dispersion. Then, it is desirable that the toner is obtained by heating and coalescing the aggregated particles formed by aggregating the resin particles in the resin particle dispersion.

Here, the high acid value dispersant will be described.
Examples of the high acid value dispersant added to the toner for developing an electrostatic latent image of the present invention include copolymer resins having a carboxyl group and salts thereof.
Examples of the monomer having a carboxyl group include α, β-ethylenically unsaturated compounds having a carboxyl group. Examples of the α, β-ethylenically unsaturated compound having a carboxyl group include acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, cinnamic acid, monomethyl maleate, monobutyl maleate, and maleic acid. Examples thereof include monooctyl ester, and among these, acrylic acid and maleic acid are particularly preferable.

  Examples of other polymerizable monomers used for the copolymer resin with a polymerizable monomer having a carboxyl group include styrene, α-methylstyrene, 4-methylstyrene, 2-methylstyrene, and 3-methyl. Aromatic vinyl monomers such as styrene, 4-methoxystyrene, 2-hydroxymethylstyrene, 4-ethylstyrene, 4-ethoxystyrene, 3,4-dimethylstyrene; methyl methacrylate, methyl acrylate, ethyl methacrylate, ethyl acrylate , Isopropyl methacrylate, isopropyl acrylate, n-butyl methacrylate, n-butyl acrylate, isobutyl methacrylate, isobutyl acrylate, octyl methacrylate, octyl acrylate, 2-ethylhexyl methacrylate, 2-ethyl Sil acrylate, lauryl methacrylate, lauryl acrylate, hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, hydroxybutyl methacrylate, hydroxybutyl acrylate, hydroxypolyoxyethylene methacrylate, hydroxypolyoxyethylene acrylate, hydroxypolyoxypropylene methacrylate Non-aromatic vinyl monomers such as (meth) acrylic acid esters such as hydroxypolyoxypropylene acrylate, hydroxypolyoxybutylene methacrylate, hydroxypolyoxybutylene acrylate, vinyl methacrylate, vinyl acrylate, allyl methacrylate, allyl acrylate, etc. Raised However, styrene and methylstyrene are preferably used.

  Desirable examples of copolymer resins using these include styrene-acrylic acid copolymer resins, styrene-acrylic acid ester-acrylic acid copolymer resins, α-methylstyrene-acrylic acid copolymer resins, and styrene-maleic acid copolymers. Examples thereof include resins and salts thereof. Moreover, a part of those copolymer resins may be esterified.

In addition, the acid value of the high acid value dispersant must be in the range of 200 to 500 mgKOH / g, but if the acid value is less than 200 mgKOH / g, the electrostatic repulsion by the carboxylic acid is insufficient. Therefore, stable granulation control becomes difficult. Even if the acid value exceeds 500 mgKOH / g, the adsorptivity of the dispersant to the surface of the polyester emulsified particles decreases, the dispersion stability due to the steric hindrance effect is insufficient, and the particle size control becomes difficult.
The acid value is desirably in the range of 200 to 500 mgKOH / g.

  In order to increase the adsorptivity of the dispersing agent on the surface of the polyester emulsified particles and obtain sufficient dispersion stability, it is preferable to use a copolymer having an acid value of 500 mgKOH / g or less. This is because by increasing the copolymerization ratio of the hydrophobic monomer and the carboxylic acid-containing monomer to the hydrophobic monomer ratio, the water solubility of the dispersant is reduced to an appropriate range and the adhesion of the dispersant to the surface of the polyester emulsion particles is increased. It is considered that there is an effect of suppressing fusion (coarse powder generation) due to contact of particles in the stirring slurry.

  Here, the acid value of the high acid value dispersant according to the present invention can be measured by the following method. That is, 2 g of a high acid value dispersant was weighed and dissolved in 160 ml of tetrahydrofuran or, if the solubility was insufficient, after dissolving the dissolvable portion, this sample was used and the acid difference was determined by potentiometric titration method of JIS K0070-1992. The price was calculated.

  Further, the weight average molecular weight Mw of the high acid value dispersant must be in the range of 1500 to 6500, preferably in the range of 2000 to 10000, and more preferably in the range of 1500 to 7000. If the weight average molecular weight Mw of the compound having the acid value in the above range is smaller than 100, the adsorption to the surface of the emulsified particles and the steric hindrance effect are insufficient, and the dispersion stability is deteriorated. Stability will deteriorate. When the molecular weight is larger than 6500, it is considered that a thickening phenomenon such as cross-linking aggregation due to the molecular chain of the dispersant occurs. Therefore, the above molecular weight range is necessary for the particle size controllability from the viewpoint of adsorptivity, steric hindrance effect, and slurry viscosity.

  Here, the measurement of the said weight average molecular weight (and number average molecular weight) was performed on condition by the following gel permeation chromatography (GPC). GPC uses “HLC-8120GPC, SC-8020 (manufactured by Tosoh Corporation)”, and the column uses two “TSKgel, SuperHM-H (6.0 mm ID × 15 cm, manufactured by Tosoh Corporation)” THF (tetrahydrofuran) was used as an eluent. As experimental conditions, the sample concentration was 0.5%, and the flow rate was 0.6 ml / min. The experiment was conducted using a sample injection amount of 10 μL, a measurement temperature of 40 ° C., and an IR detector. The calibration curve is “polystylen standard sample TSK standard” manufactured by Tosoh Corporation: “A-500”, “F-1”, “F-10”, “F-80”, “F-380”, “A-2500”. ”,“ F-4 ”,“ F-40 ”,“ F-128 ”, and“ F-700 ”.

  In order to measure the acid value and the like of the high acid value dispersant in the product toner, the high acid value dispersant has a high acid value and a low molecular weight, so it exhibits good solubility in alkaline water. Therefore, the high acid value dispersant is separated from the toner and analyzed. Specifically, the toner is sufficiently dissolved in an organic solvent such as tetrahydrofuran, and then this is stirred and mixed with ion-exchanged water adjusted to alkali to separate into an aqueous phase and an oil phase, and then dissolved in an alkaline aqueous phase. Remove the dispersant component. Thereafter, the composition value by NMR or the like, the molecular weight measurement by GPC, and the acid value can be measured for this component, and the acid value of the high acid value dispersant can be obtained.

In the present invention, the content of the high acid value dispersant in the toner is preferably in the range of 0.1 to 20% by mass, and more preferably in the range of 0.3 to 10% by mass in terms of solid content. If the content of the high acid value dispersant in the toner is 0.1% by mass or more, sufficient electrostatic repulsion can be obtained. On the other hand, if the content is 20% by mass or less, it can be easily removed by washing. Good electrical (charging) characteristics at high humidity can be obtained.
The above high acid value dispersant is added in consideration of, for example, the solid content concentration of the dispersion (resin particle dispersion) during the production by the aggregation / unification method and the amount of polar groups in the binder resin during aggregation. It is desirable to do. Specifically, when the acid value of the polyester resin described later is large, the addition amount of the high acid value dispersant is adjusted to be small, and when the acid value of the polyester resin is low, the addition amount of the high acid value dispersant is increased. Adjust more.

Next, the components of the toner of the present invention will be described together with the toner production method.
-Polyester resin-
A polyester resin such as a crystalline polyester resin or an amorphous polyester resin used in the toner of the present invention is preferably synthesized from a polyvalent carboxylic acid component and a polyhydric alcohol component. In the present invention, a commercially available product may be used as the polyester resin, or a synthesized product may be used.

  Here, the “crystalline polyester resin” refers to a resin having a clear endothermic peak rather than a stepwise endothermic amount change in differential scanning calorimetry (DSC). On the other hand, a resin in which a stepwise endothermic change is recognized in DSC means an “amorphous polyester resin”.

  Examples of the polyvalent carboxylic acid component include oxalic acid, succinic acid, fumaric acid, glutaric acid, adipic acid, peric acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, and 1,10-decanedicarboxylic acid. Aliphatic dicarboxylic acids such as 1,12-dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid; phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, malon Aromatic dicarboxylic acids such as dibasic acids such as acid and mesaconic acid; alicyclic carboxylic acids such as cyclohexanedicarboxylic acid, and the like, and these anhydrides and lower alkyl esters thereof are also included. is not.

  Examples of the trivalent or higher carboxylic acid include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, and the like, and anhydrides thereof. And lower alkyl esters. These may be used individually by 1 type and may use 2 or more types together.

  Furthermore, it is also possible to contain a dicarboxylic acid component having a double bond in addition to the aforementioned aliphatic dicarboxylic acid and aromatic dicarboxylic acid. A dicarboxylic acid having a double bond can be suitably used to prevent hot offset at the time of fixing in that it can be radically cross-linked through the double bond. Examples of the dicarboxylic acid include, but are not limited to, maleic acid, fumaric acid, 3-hexenedioic acid, and 3-octenedioic acid. In addition, these lower esters, acid anhydrides and the like are also included. Among these, fumaric acid, maleic acid and the like are mentioned in terms of cost.

  Examples of the polyhydric alcohol component include aliphatic diols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, and glycerin; cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol A And the like; and aromatic diols such as an ethylene oxide adduct of bisphenol A and a propylene oxide adduct of bisphenol A; One or more of these polyhydric alcohols can be used.

  In the case of an amorphous polyester resin, among these polyhydric alcohols, aromatic diols and alicyclic diols are desirable, and aromatic diols are more desirable. On the other hand, in the case of a crystalline polyester resin, an aliphatic diol is desirable, and a linear aliphatic diol having 7 to 20 carbon atoms in the main chain portion is more desirable. When the aliphatic diol is branched, the crystallinity of the polyester resin is lowered and the melting point is lowered, so that good toner blocking resistance, image storage stability, and low-temperature fixability may not be obtained. Further, when the number of carbon atoms is less than 7, when the polycondensation with aromatic dicarboxylic acid is performed, the melting point becomes high and fixing at low temperature may be difficult. On the other hand, when the number exceeds 20, it is difficult to obtain practical materials. easy. The carbon number is more preferably 14 or less.

  Specific examples of the aliphatic diol suitably used for the synthesis of the crystalline polyester resin include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1 , 6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1, Examples include, but are not limited to, 13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, 1,14-eicosandecanediol, and the like. Among these, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are preferable in view of availability.

  Examples of the trivalent or higher alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like. These may be used individually by 1 type and may use 2 or more types together.

  Of the polyhydric alcohol components preferably used for the synthesis of the crystalline polyester, the content of the aliphatic diol component is desirably 80 mol% or more, and more desirably 90 mol% or more. When the content of the aliphatic diol component is less than 80 mol%, the crystallinity of the polyester resin is lowered and the melting point is lowered, so that good toner blocking resistance, image storage stability and low-temperature fixability may not be obtained. is there.

  If necessary, monovalent acids such as acetic acid and benzoic acid, and monovalent alcohols such as cyclohexanol and benzyl alcohol can be used for the purpose of adjusting the acid value and the hydroxyl value.

  The polyester resin can be produced by subjecting the polyhydric alcohol and polyhydric carboxylic acid to a condensation reaction according to a conventional method. For example, a catalyst is added to the polyhydric alcohol and polyhydric carboxylic acid, if necessary, and blended in a reaction vessel equipped with a thermometer, a stirrer, and a flow-down condenser, and in the presence of an inert gas (such as nitrogen gas). , Heated at 150-250 ° C to continuously remove by-product low-molecular compounds out of the reaction system, stop the reaction when a predetermined acid value is reached, cool, and obtain the desired reactant Can be manufactured.

  Examples of the catalyst used for the synthesis of this polyester resin include esterification catalysts such as organic metals such as dibutyltin dilaurate and dibutyltin oxide, and metal alkoxides such as tetrabutyl titanate. The amount of the catalyst added is preferably 0.01 to 1% by mass relative to the total amount of raw materials.

  The molecular weight of the amorphous polyester resin used in the toner of the present invention is a molecular weight measurement by the gel permeation chromatography (GPC) method of tetrahydrofuran (THF) soluble matter, and the weight average molecular weight (Mw) is 5,000 to 200,000. The number average molecular weight (Mn) is desirably in the range of 2000 to 10,000, and the molecular weight distribution Mw / Mn is in the range of 1.5 to 50. It is desirable that it is in the range, and more preferably in the range of 2 to 10.

  The crystalline polyester resin preferably has a weight average molecular weight (Mw) of 5000 to 70000, more preferably 15000 to 50000, and a number average molecular weight (Mn) of 2000 to 20000. The molecular weight distribution Mw / Mn is preferably in the range of 1.5 to 10, more preferably in the range of 2.0 to 4.0.

When the weight average molecular weight and the number average molecular weight are smaller than the above ranges, while effective for low-temperature fixability, not only the hot offset resistance is remarkably deteriorated, but also the glass transition point of the toner is lowered. The storage stability such as toner blocking may be adversely affected. On the other hand, if the molecular weight is larger than the above range, the hot offset resistance can be sufficiently provided, but the low-temperature fixability is deteriorated and the oozing of the crystalline polyester phase present in the toner is inhibited, so that the document storage stability is reduced. May be adversely affected. Therefore, by satisfying the above conditions, it becomes easy to achieve both low-temperature fixability, hot offset resistance, and document storage stability.
In addition, a weight average molecular weight and a number average molecular weight can be measured by the method according to the measuring method in the said high acid value dispersing agent.

  The acid value of the polyester resin (the number of mg of KOH required to neutralize 1 g of resin) is easy to obtain the above-mentioned preferred molecular weight distribution, and it is easy to ensure the granulation property of the toner particles by the emulsion dispersion method. The environmental stability of the obtained toner (charging stability when the temperature and humidity change) is easily maintained, and therefore it is desirable that the toner is in the range of 1 to 30 mg KOH / g. The acid value of the polyester resin can be adjusted by controlling the carboxyl group at the terminal of the polyester according to the blending ratio of the raw polyhydric carboxylic acid and polyhydric alcohol and the reaction rate. Or what has a carboxyl group in the principal chain of polyester is obtained by using trimellitic anhydride as a polyvalent carboxylic acid component.

  The glass transition temperature of the amorphous polyester resin used in the present invention is preferably in the range of 35 to 100 ° C., and is 50 to 80 ° C. from the viewpoint of the balance between storage stability and toner fixing property. Is more preferred. When the glass transition temperature is less than 35 ° C., the toner tends to be blocked during the storage or in the developing machine (a phenomenon in which toner particles are aggregated into a lump). On the other hand, when the glass transition temperature exceeds 100 ° C., the fixing temperature of the toner becomes high, which is not desirable.

The melting point of the crystalline polyester resin used in the present invention is desirably in the range of 60 to 120 ° C, and more preferably in the range of 70 to 100 ° C. When the melting point of the crystalline polyester resin is less than 60 ° C., the powder is likely to be aggregated or the storage stability of the fixed image may be deteriorated. On the other hand, if the temperature exceeds 120 ° C., image roughness may occur and low-temperature fixability may be impaired.
In addition, melting | fusing point of the said crystalline polyester resin was calculated | required as the peak temperature of the endothermic peak obtained by the said differential scanning calorimetry (DSC).

-Colorant-
The colorant used in the toner of the present invention is not particularly limited as long as it is a known colorant, and examples thereof include carbon black such as furnace black, channel black, acetylene black, and thermal black, bengara, bitumen, and titanium oxide. Inorganic pigments, fast yellow, disazo yellow, pyrazolone red, chelate red, brilliant carmine, para-brown and other azo pigments; copper phthalocyanine, metal-free phthalocyanine and other phthalocyanine pigments; flavantron yellow, dibromoanthrone orange, perylene red, quinacridone red, And condensed polycyclic pigments such as dioxazine violet.

  Specifically, Chrome Yellow, Hansa Yellow, Benzidine Yellow, Slen Yellow, Quinoline Yellow, Permanent Orange GTR, Pyrarozone Orange, Vulcan Orange, Watch Young Red, Permanent Red, Dupont Oil Red, Resol Red, Rhodamine B Lake, Lake Red C, Rose Bengal, Aniline Blue, Ultramarine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Phthalocyanine Green, Malachite Green Oxalate, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 122, C.I. I. Pigment 57: 1, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 17, C.I. I. Pigment blue 15: 1, C.I. I. Examples thereof include various pigments such as CI Pigment Blue 15: 3, and these can be used alone or in combination of two or more.

  The content of the colorant is preferably in the range of 1 to 30 parts by mass with respect to 100 parts by mass of the binder resin, and a colorant that has been surface-treated as necessary or a pigment dispersant may be used. It is also effective to use. By selecting the type of the colorant, yellow toner, magenta toner, cyan toner, black toner, and the like can be obtained.

-Release agent-
The release agent is not particularly limited as long as it is a known release agent. For example, natural waxes such as carnauba wax, rice wax, and candelilla wax; low molecular weight polypropylene, low molecular weight polyethylene, sazole wax, microcrystalline Examples include, but are not limited to, synthesis of wax, Fischer-Tropsch wax, paraffin wax, montan wax and the like, or mineral / petroleum wax; ester wax such as fatty acid ester and montanic acid ester. Moreover, these mold release agents may be used individually by 1 type, and may be used together 2 or more types.

  The melting point of the release agent is preferably 50 ° C. or higher, and more preferably 60 ° C. or higher, from the viewpoint of storage stability. Further, from the viewpoint of offset resistance, the temperature is desirably 110 ° C. or less, and more desirably 100 ° C. or less.

  The content of the release agent is preferably in the range of 2 to 30 parts by mass, and more preferably in the range of 3 to 20 parts by mass with respect to 100 parts by mass of the binder resin. If the content of the release agent is less than 2 parts by mass, the effect of adding the release agent is not obtained, and hot offset at a high temperature may be caused. On the other hand, if the amount exceeds 30 parts by mass, the chargeability may be adversely affected, and the mechanical strength of the toner tends to be reduced. There is.

  In addition to the above components, various components such as an internal additive, a charge control agent, inorganic powder (inorganic particles), and organic particles can be added to the toner of the present invention as necessary.

Examples of the internal additive include metals such as ferrite, magnetite, reduced iron, cobalt, nickel, and manganese, alloys, and magnetic materials such as compounds containing these metals.
When the magnetic material is used as a magnetic toner, the ferromagnetic particles preferably have an average particle size of 2 μm or less, more preferably about 0.1 to 0.5 μm. The amount contained in the toner is preferably 20 to 200 parts by mass with respect to 100 parts by mass of the resin component, and particularly preferably 40 to 150 parts by mass with respect to 100 parts by mass of the resin component. Further, it is desirable that the magnetic characteristics when applied with 10K Oersted are those having a coercive force (Hc) of 20 to 300 Oersted, saturation magnetization (σs) of 50 to 200 emu / g, and residual magnetization (σr) of 2 to 20 emu / g.

  Examples of the charge control agent include quaternary ammonium salt compounds, nigrosine compounds, dyes composed of complexes of aluminum, iron, chromium, and triphenylmethane pigments.

  The inorganic powder is added mainly for the purpose of adjusting the viscoelasticity of the toner. For example, normal toners such as silica, alumina, titania, calcium carbonate, magnesium carbonate, calcium phosphate, and cerium oxide are listed in detail below. All inorganic particles used as surface external additives can be mentioned.

Examples of inorganic particles and organic particles externally added to the toner surface include the following.
Examples of inorganic particles include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, cerium chloride, Examples include Bengala, chromium oxide, cerium oxide, antimony trioxide, magnesium oxide, zirconium oxide, silicon carbide, and silicon nitride. Among these, silica particles and titanium oxide particles are desirable, and particles that have been subjected to hydrophobic treatment are particularly desirable.

Inorganic particles are generally used for the purpose of improving fluidity. The primary particle diameter of the inorganic particles is desirably in the range of 1 to 200 nm, and the addition amount is desirably in the range of 0.01 to 20 parts by mass with respect to 100 parts by mass of the toner.
Organic particles are generally used for the purpose of improving cleaning properties and transfer properties. Specifically, for example, fluorine resin powders such as polyvinylidene fluoride and polytetrafluoroethylene, fatty acid metal salts such as zinc stearate and calcium stearate. , Polystyrene, polymethyl methacrylate and the like.

  The production of the electrostatic latent image developing toner of the present invention is preferably carried out by wet granulation. Examples of the wet granulation method include known melt suspension methods, emulsion aggregation methods, dissolution suspension methods, and the like. Among them, the emulsion aggregation method is preferably used in the present invention.

The emulsion aggregation method includes an emulsification step in which each raw material such as a polyester resin and a colorant is dispersed in an aqueous dispersion medium, an aggregation step in which aggregated particles are produced from a raw material dispersion obtained by mixing each dispersion, and the aggregated particles. At least a fusing step of fusing to obtain toner. In addition, a coating step (shell layer forming step) for covering the surface of the aggregated particles with the same or different resin particles as the binder resin is included as necessary.
Hereinafter, each step will be described in detail.

-Emulsification process-
In the emulsion aggregation method, since the binder resin and the colorant are mixed as respective emulsified particles as a raw material dispersion, the emulsification step is a step of preparing an emulsified dispersion of the above raw material. Therefore, first, the binder resin needs to be dispersed in advance as resin particles in the raw material dispersion.

  The volume average particle diameter of the emulsified resin particles is preferably 0.01 to 1 μm, more preferably 0.03 to 0.8 μm, and further preferably 0.03 to 0.6 μm. When the average particle diameter exceeds 1 μm, the particle diameter distribution of the finally obtained toner for developing an electrostatic latent image is broadened or free particles are generated, which tends to deteriorate performance and reliability. On the other hand, when the average particle size is within the above range, there are no disadvantages, the compositional uneven distribution among the toners is reduced, the dispersion in the toner is improved, and the variation in performance and reliability is advantageous. . The volume average particle diameter can be measured using, for example, a Coulter counter method, a photon correlation method, a laser diffraction / scattering method, a white light polarization method, or the like.

  The dispersion medium in the dispersion is preferably an aqueous medium. Examples of the aqueous medium include water such as distilled water and ion exchange water, and alcohols. These may be used individually by 1 type and may use 2 or more types together. In the present invention, it is preferable to add and mix a surfactant in the aqueous medium. Although it does not specifically limit as surfactant, For example, anionic surfactants, such as sulfate ester type, sulfonate type, phosphate ester type, soap type; amine salt type, quaternary ammonium salt type, etc. Nonionic surfactants such as polyethylene glycol-based, alkylphenol ethylene oxide adduct-based, polyhydric alcohol-based, and the like. Among these, anionic surfactants and cationic surfactants are preferable. The nonionic surfactant is preferably used in combination with the anionic surfactant or the cationic surfactant. The said surfactant may be used individually by 1 type, and may use 2 or more types together.

  Specific examples of the anionic surfactant include sodium dodecylbenzenesulfonate, sodium dodecylsulfate, sodium alkylnaphthalenesulfonate, sodium dialkylsulfosuccinate and the like. Specific examples of the cationic surfactant include alkylbenzene dimethyl ammonium chloride, alkyl trimethyl ammonium chloride, distearyl ammonium chloride and the like.

When a polyester resin is used as the binder resin particles as in the present invention, the polyester resin is preferably a polyester resin having a self-water dispersibility containing a functional group that can be made anionic by neutralization. By neutralizing a part or all of the functional groups that can be anionic with a base, a stable aqueous dispersion can be formed under the action of an aqueous medium.
In addition, examples of the functional group that can be converted into an anionic type by neutralization in the polyester resin include acidic groups such as a carboxyl group and a sulfone group. Examples of the neutralizing agent include sodium hydroxide, potassium hydroxide, lithium hydroxide, Examples thereof include inorganic bases such as calcium hydroxide, sodium carbonate and ammonia, and organic bases such as diethylamine, triethylamine and isopropylamine.

  Further, when a polyester resin that does not disperse in water, that is, does not have self-water dispersibility, is used as the binder resin, an ionic surfactant, a polymer is added to the resin solution and / or an aqueous medium mixed therewith. It is preferable to perform treatment using a homogenizer or a pressure discharge type disperser capable of applying a strong shearing force by adding and dispersing a polymer electrolyte such as an acid or a polymer base, heating it to a melting point or higher. By treating in this way, it can be easily dispersed in particles of 0.5 μm or less. When the ionic surfactant or polymer electrolyte is used, the concentration in the aqueous medium is suitably 0.5 to 5% by mass. The mold release agent described later also applies to this.

  Furthermore, as a method of dispersing another polyester resin, a phase inversion emulsification method may be mentioned. In the phase inversion emulsification method, a resin to be dispersed is dissolved in a hydrophobic organic solvent in which the resin is soluble, a base is added to the organic continuous phase (O phase), and the aqueous medium (W Phase), the resin is converted from W / O to O / W (so-called phase inversion) to form a discontinuous phase, and the resin is dispersed and stabilized in the form of particles in an aqueous medium. It is.

  Examples of the organic solvent used for this phase inversion emulsification include ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, and tert. -Alcohols such as amyl alcohol, 1-ethyl-1-propanol, 2-methyl-1-butanol, n-hexanol, cyclohexanol, ketones such as methyl ethyl ketone, methyl isobutyl ketone, ethyl butyl ketone, cyclohexanone, isophorone, tetrahydrofuran , Ethers such as dimethyl ether, diethyl ether, dioxane, methyl acetate, ethyl acetate, acetic acid-n-propyl, isopropyl acetate, acetic acid-n-butyl, isobutyl acetate, vinegar -Sec-butyl, acetate-3-methoxybutyl, methyl propionate, ethyl propionate, butyl propionate, dimethyl oxalate, diethyl oxalate, dimethyl succinate, diethyl succinate, diethyl carbonate, dimethyl carbonate, Ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol ethyl ether acetate, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether , Diethylene glycol ethyl ether acetate Glycol derivatives such as propylene glycol, propylene glycol monomethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol methyl ether acetate, dipropylene glycol monobutyl ether, 3-methoxy-3-methylbutanol, 3-methoxy Examples include butanol, acetonitrile, dimethylformamide, dimethylacetamide, diacetone alcohol, ethyl acetoacetate and the like. These solvents can be used singly or in combination of two or more.

  In the above phase inversion emulsification, when dispersing the binder resin in water, it is preferable to neutralize part or all of the carboxyl groups in the resin with a neutralizing agent, if necessary. Examples of the neutralizing agent include inorganic alkalis such as potassium hydroxide and sodium hydroxide, ammonia, monomethylamine, dimethylamine, triethylamine, monoethylamine, diethylamine, triethylamine, mono-n-propylamine, dimethyl-n-propylamine, Amines such as monoethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, N-aminoethylethanolamine, N-methyldiethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, N, N-dimethylpropanolamine 1 type or 2 types or more selected from these can be used. By adding these neutralizing agents, the pH during emulsification can be adjusted to neutral, and hydrolysis of the resulting polyester resin dispersion can be prevented.

  Also during the phase inversion emulsification, a dispersant may be added for the purpose of stabilizing the dispersed particles and preventing the thickening of the aqueous medium. Examples of the dispersant include water-soluble polymers such as polyvinyl alcohol, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, sodium polyacrylate, and sodium polymethacrylate, sodium dodecylbenzenesulfonate, sodium octadecylsulfate, and oleic acid. Anionic surfactants such as sodium, sodium laurate, potassium stearate, cationic surfactants such as laurylamine acetate, stearylamine acetate, lauryltrimethylammonium chloride, zwitterionic surfactants such as lauryldimethylamine oxide, Polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl amine, etc. Surfactants such as on-surfactant, tricalcium phosphate, aluminum hydroxide, calcium sulfate, calcium carbonate, and inorganic compounds such as barium carbonate. These dispersants may be used alone or in combination of two or more. The dispersant is preferably added in an amount of 0.01 to 20 parts by mass with respect to 100 parts by mass of the binder resin.

  The emulsification temperature during phase inversion emulsification is preferably not higher than the boiling point of the organic solvent and not lower than the melting point (or transition point) of the release agent. If the emulsification temperature is not higher than the melting point or transition point of the release agent, a particle dispersion containing the release agent cannot be obtained. In addition, when emulsifying above the boiling point of the organic solvent, the emulsification may be performed with a pressure-sealed device.

As the colorant to be emulsified and dispersed as the raw material dispersion, the colorants described above can be used.
As a method for dispersing the colorant, for example, a general dispersion method such as a rotary shear type homogenizer, a ball mill having a medium, a sand mill, or a dyno mill can be used, and the colorant is not limited at all. If necessary, an aqueous dispersion of these colorants can be prepared using a surfactant, or an organic solvent dispersion of these colorants can be prepared using a dispersant. Hereinafter, such a colorant dispersion may be referred to as a “colored particle dispersion”. As the surfactant or dispersant used for dispersion, those according to the dispersant that can be used when dispersing the binder resin can be used.

  The addition amount of the colorant is preferably 1 to 20% by mass, more preferably 1 to 10% by mass, and still more preferably 2 to 10% by mass with respect to the total amount of the resin. 2 to 7% by mass is particularly desirable, but a larger amount is preferable as long as the image surface is not roughened after fixing. When the content of the colorant is increased, the thickness of the image can be reduced when an image having the same density is obtained, which is advantageous in terms of prevention of offset.

  These colorants may be added to the mixed solvent at the same time as other particle components, or may be divided and added in multiple stages.

As the release agent emulsified and dispersed as the raw material dispersion, the release agent described above can be used.
The release agent is a homogenizer that can disperse together with an ionic surfactant, etc. in water according to the case of emulsifying and dispersing a polyester resin that does not have self-water dispersibility, heat it above its melting point, and apply a strong shearing force. Or a pressure discharge type disperser to adjust the dispersed particle diameter to 1 μm or less. As the dispersion medium in the release agent dispersion liquid, a dispersion medium according to the binder resin dispersion medium can be used.

  As an apparatus for mixing and dispersing the binder resin and the colorant with an aqueous medium, for example, a homomixer (Special Machine Industries Co., Ltd.), Thrasher (Mitsui Mining Co., Ltd.), Cavitron (Eurotech Co., Ltd.), Examples thereof include continuous emulsion dispersers such as a microfluidizer (Mizuho Industrial Co., Ltd.), a Menton Gorin homogenizer (Gorin Inc.), a nanomizer (Nanomizer Inc.), a static mixer (Noritake Company), and the like.

  The content of the resin particles contained in the binder resin dispersion (resin particle dispersion) in the emulsification step, the content of the colorant in the colorant dispersion (colored particle dispersion), and the release agent dispersion 5-50 mass% is suitable for content of the mold release agent in (release agent particle dispersion liquid), More preferably, it is 10-40 mass%. When the content is outside the above range, the particle size distribution may be widened and the characteristics may be deteriorated.

In the present invention, other components such as the internal additive, the charge control agent, and the inorganic powder described above may be dispersed in the binder resin dispersion according to the purpose.
In addition, as the charge control agent in the present invention, a material that is difficult to dissolve in water is preferable in terms of controlling ionic strength that affects the stability of the aggregation process and the fusion process and reducing wastewater contamination.

  The average particle size of the other components is desirably 1 μm or less, and more preferably 0.01 to 0.5 μm. When the average diameter exceeds 1 μm, the particle diameter distribution of the finally obtained toner for developing an electrostatic latent image is broadened, or free particles are generated, which tends to deteriorate performance and reliability. On the other hand, when the average particle diameter is within the above range, there are no disadvantages, and the uneven distribution among the toners is reduced, the dispersion in the toner is good, and the variation in performance and reliability is advantageous.

-Aggregation process-
In the agglomeration step, the respective dispersions of resin particles, colorants and the like obtained in the emulsification step are mixed (this mixture is referred to as “raw material dispersion”), and heated to a temperature of 50 ° C. or less, for example. Aggregated particles are formed by aggregating the dispersed particles.

  When the toner of the present invention is manufactured, the high acid value dispersant may be added as an additive to the resin particle dispersion (polyester resin dispersion) obtained by the emulsification step before the aggregation step. desirable. By adding a high acid value dispersing agent and adsorbing it on the emulsified particle surface of the polyester resin, the surface of the emulsified particle is maintained in a state where the electrostatic repulsion is sufficiently applied, thereby suppressing rapid particle growth in the aggregation process. It becomes possible to do. In addition, since the electrostatic repulsion effect derived from these anionic dissociation groups acts also in the fusion step described later, adhesion between the aggregated particles can be sufficiently prevented, and stable granulation control can be performed. Furthermore, the method of adding the high acid value dispersant after completion of the aggregation can sufficiently prevent the aggregation particles from adhering in the fusing step, and enables stable granulation control.

  Agglomerated particles are formed by acidifying the pH of the raw material dispersion, adding a flocculant at room temperature (20-25 ° C, the same applies to this) under high-speed stirring with a rotary shearing homogenizer, and increasing by initial aggregation. This is done by dispersing the flocculant in the viscous raw material dispersion. As the said pH, the range of 2-6 is desirable, and the range of 3-6 is more suitable.

  As described above, an acidic pH range is suitable for the formation of aggregated particles. For example, since the resin particle dispersion of a polyester resin obtained by the phase inversion emulsification method has a pH in the range of 7 to 8, If a colorant dispersion or a release agent dispersion having a pH of 3 to 5 is mixed or adjusted to the above pH for aggregation, the balance of polarity is lost and slow aggregation occurs. Therefore, when the pH of the resin particle dispersion of the polyester resin is on the alkali side, a surfactant or the above-mentioned high acid value dispersant is added in advance at room temperature to allow the surfactant and dispersant to blend into the resin particle surface. After that, it is preferable to adjust the pH by mixing a colorant and a release agent.

  As the aggregating agent used in the aggregating step, it is preferable to use a divalent or higher-valent metal complex in addition to a surfactant having an opposite polarity to the surfactant used when preparing the dispersion, an inorganic metal salt, and the like. it can. In particular, when a metal complex is used, the amount of the surfactant used can be reduced and charging characteristics are improved, which is desirable.

  Examples of the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate, and polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. Examples thereof include inorganic metal salt polymers. Of these, aluminum salts and polymers thereof are particularly preferred. In order to obtain a sharper particle size distribution, the valence of the inorganic metal salt is bivalent than monovalent, trivalent than bivalent, trivalent than trivalent, and tetravalent than trivalent. The inorganic metal salt polymer is more suitable.

  In the aggregation step, in order to suppress rapid aggregation due to heating, the pH may be adjusted while stirring and mixing at room temperature, and a dispersion stabilizer may be added as necessary.

  In the final toner, it is desirable to add a coating step after the aggregation step in order to further improve the chargeability and powder flowability. In this coating step, the same or different resin particles as the binder resin are adhered to the surface of the above-mentioned aggregated particles to form adhered particles to form a coating layer (that is, a toner having a core-shell structure). . The formation can be performed by additionally adding a dispersion liquid containing a binder resin or other resin particles to the dispersion liquid in which the aggregated particles are formed in the aggregation process. It may be added. In addition, as a binder resin (resin particle) used for formation of a coating layer, the thing according to the above-mentioned binder resin (namely, binder resin for core layers) can be used. Also in the coating process, the pH and surfactant are selected according to the agglomeration process according to the resin used, and the coated aggregated particles are obtained with care so as not to adhere to the surface of the aggregated particles. This coating step is also effective in guiding raw material particles that have not been taken into the aggregated particles in the aggregation step.

-Fusion process-
In the fusion step, the agglomeration is stopped by advancing the aggregation by adjusting the pH of the suspension of the agglomerated particles (or attached particles) to a range of 6.0 to 7.5 under stirring according to the agglomeration step. The aggregated particles (or adhered particles) are fused by heating at a temperature equal to or higher than the melting point of the binder resin. Although depending on the liquidity of the dispersion containing the aggregated particles (raw material dispersion), if the pH at which aggregation is stopped is not appropriate, the aggregated particles will be dispersed during the temperature rising process for fusing, resulting in a high yield. In some cases, the agglomeration becomes worse, or condensation cannot be stopped, and the particle size growth further proceeds, resulting in a large particle size.

  When the crystalline polyester resin is contained in the aggregated particles, the heating temperature at the time of fusing is not a problem as long as the temperature is not lower than the melting point, and if not included, the temperature is not lower than the glass transition point of the amorphous resin. The heating time may be performed as long as desired fusion is performed, and may be performed for about 0.5 to 3 hours. When heated for a longer time, the release agent contained in the aggregated particles is likely to be exposed on the toner surface. Therefore, although it is effective for fixing properties, it is undesirable to heat for a long time because it adversely affects the storage stability of the toner.

  In the fusion step, a crosslinking reaction may be performed when the binder resin is heated to a melting point or a glass transition point or higher, or after the fusion is completed. In addition, a crosslinking reaction can be performed simultaneously with the fusion. When the crosslinking reaction is performed, for example, an unsaturated crystalline polyester resin obtained by copolymerizing a double bond component as a binder resin is used, and a radical reaction is caused in the resin to introduce a crosslinked structure. At this time, the following polymerization initiator is preferably used.

Examples of the polymerization initiator include t-butyl peroxy-2-ethylhexanoate, cumyl perpivalate, t-butyl peroxylaurate, benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, di-t. -Butyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide, 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 1,1-bis (t-butylperoxy) -3,3,5-trimethyl Cyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, 1,4-bis (t-butylperoxycarbo) Nyl) cyclohexane, 2,2-bis (t-butylperoxy) octane, n-butyl 4,4-bis (t-butylperoxy) valerate, 2,2-bis (t-butylperoxy) butane, , 3-bis (t-butylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylper) Oxy) hexane, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, di-t-butyldiperoxyisophthalate, 2,2-bis (4,4-di-t-butylperoxy) (Cyclohexyl) propane, di-t-butylperoxy α-methylsuccinate, di-t-butylperoxydimethylglutarate, di-t-butylperoxyhexahydroterephthalate , Di-t-butylperoxyazelate, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, diethylene glycol-bis (t-butylperoxycarbonate), di-t-butyl Peroxytrimethyladipate, tris (t-butylperoxy) triazine, vinyltris (t-butylperoxy) silane, 2,2′-azobis (2-methylpropionamidine dihydrochloride), 2,2′-azobis [N -(2-carboxyethyl) -2-methylpropionamidine], 4,4′-azobis (4-cyanovaleric acid) and the like.
These polymerization initiators can be used alone or in combination of two or more. The amount and type of the polymerization initiator are selected depending on the amount of unsaturated sites in the binder resin and the type and amount of the coexisting colorant.

  The polymerization initiator may be previously mixed with the binder resin before the emulsification step, or may be incorporated into the aggregated particles in the aggregation step. Further, it may be introduced after the fusion step or after the fusion step. When the polymerization initiator is introduced during the aggregation process, the coating process, the fusion process, or after the fusion process, a solution in which the polymerization initiator is dissolved or emulsified is added to the resin particle dispersion or the like. These polymerization initiators may be added with known crosslinking agents, chain transfer agents, polymerization inhibitors and the like for the purpose of controlling the degree of polymerization.

The fused particles obtained by fusing can be made into toner particles through a solid-liquid separation process such as filtration and, if necessary, a washing process and a drying process. In this case, in order to ensure sufficient charging characteristics and reliability as a toner, it is preferable to perform sufficient cleaning in the cleaning step.
In the drying step, methods such as a normal vibration type fluidized drying method, a spray drying method, a freeze drying method, and a flash jet method can be employed.

Toner particles after drying, the water content in the after standing 3 days under the environment of 28 ° C. / 85% RH is not more than 1.5 wt%, and more desirably 1.0% by mass or less. When the water content is in the above range, the charge amount of the toner does not decrease under high humidity conditions, and the toner charging characteristics due to humidity change can be stabilized.
The toner moisture content was measured by leaving 2 g of toner in an environment of 28 ° C. and humidity 85% RH for 24 hours, and then evaporating water at a heating temperature of 150 ° C. using a halogen moisture analyzer (manufactured by METTLER TOLEDO). This can be done by measuring the amount.

  To the toner particles granulated through the drying step as described above, various known external additives such as the inorganic particles and organic particles described above can be added as other components depending on the purpose.

  The volume average particle diameter of the electrostatic latent image developing toner of the present invention is preferably in the range of 1 to 20 μm, and more preferably in the range of 2 to 8 μm. Further, the number average particle diameter is preferably in the range of 1 to 20 μm, and more preferably in the range of 2 to 8 μm.

  The volume average particle size and number average particle size can be measured by measuring with a 50 μm aperture diameter using a Coulter Multisizer II type (manufactured by Beckman-Coulter). At this time, the measurement is performed after the toner is dispersed in an electrolyte aqueous solution (Isoton aqueous solution) and dispersed by ultrasonic waves for 30 seconds or more.

  In the toner of the present invention, the softening temperature T f1 / 2 in the measurement of the flow tester viscosity is preferably 85 ° C. or higher and 115 ° C. or lower, and more preferably 90 ° C. or higher and 110 ° C. or lower. When the temperature is higher than 115 ° C., the melt viscosity at the time of fixing is high, which may adversely affect the low-temperature fixability, which is not preferable. Further, if it is 85 ° C. or lower, it may affect the storage stability of the toner, which is not preferable.

<Electrostatic latent image developer>
The toner for developing an electrostatic latent image of the present invention is used as it is as a one-component developer or as a two-component developer. When used as a two-component developer, it is used by mixing with a carrier.

  There is no restriction | limiting in particular as a carrier which can be used for a two-component developer, A well-known carrier can be used. Examples thereof include magnetic metals such as iron oxide, nickel and cobalt, magnetic oxides such as ferrite and magnetite, resin-coated carriers having a resin coating layer on the surface of the core material, and magnetic dispersion carriers. Further, a resin-dispersed carrier in which a conductive material or the like is dispersed in a matrix resin may be used.

  Coating resins and matrix resins used for carriers include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, styrene-acrylic. Examples include acid copolymers, straight silicone resins containing organosiloxane bonds or modified products thereof, fluororesins, polyesters, polycarbonates, phenol resins, epoxy resins, etc., but are not limited thereto. Absent.

  Examples of the conductive material include metals such as gold, silver and copper, carbon black, titanium oxide, zinc oxide, barium sulfate, aluminum borate, potassium titanate, tin oxide, and carbon black. It is not limited.

  Examples of the core material of the carrier include magnetic metals such as iron, nickel, and cobalt, magnetic oxides such as ferrite and magnetite, and glass beads. However, in order to use the carrier for the magnetic brush method, it is a magnetic material. It is preferable.

  The volume average particle size of the core material of the carrier is generally 10 to 500 μm, and preferably 30 to 100 μm.

  In order to coat the surface of the core material of the carrier with a resin, there may be mentioned a method of coating with a coating layer forming solution in which the coating resin and, if necessary, various additives are dissolved in an appropriate solvent. The solvent is not particularly limited, and may be selected in consideration of the coating resin to be used, coating suitability, and the like.

  Specific resin coating methods include an immersion method in which the carrier core material is immersed in the coating layer forming solution, a spray method in which the coating layer forming solution is sprayed onto the surface of the carrier core material, and the carrier core material is fluidized air. And a kneader coater method in which the carrier core material and the coating layer forming solution are mixed in a kneader coater and the solvent is removed in a kneader coater.

In the present invention, the carrier shape factor SF1 is preferably in the range of 115 to 140. This is because a sufficient charge amount can be obtained at the time of restarting printing by appropriately controlling the contact area between the carrier and the toner as described above. In particular, the toner containing the crystalline polyester resin is hardly stressed, and the durability of the developer can be improved.
The shape factor SF1 is more preferably in the range of 125 to 135.

Here, the shape factor SF1 is obtained by the following equation (1).
SF1 = (ML ² / A) × (π / 4) × 100 (1)
In the above formula (1), ML represents the absolute maximum length of the toner particles, and A represents the projected area of the toner particles.

  The SF1 is quantified mainly by analyzing a microscope image or a scanning electron microscope (SEM) image using an image analyzer, and can be calculated as follows, for example. That is, an optical microscope image of toner particles dispersed on the surface of a slide glass is taken into a Luzex image analyzer through a video camera, and the maximum length and projected area of 100 particles are obtained, calculated by the above equation (1), and the average Obtained by determining the value.

  The mixing ratio (mass ratio) of the toner of the present invention and the carrier in the two-component developer is in the range of toner: carrier = 1: 100 to 30: 100, and about 3: 100 to 20: 100. A range is more preferred.

  On the other hand, when the toner for developing an electrostatic latent image of the present invention is used as a one-component developer and a magnetic toner in which a magnetic substance is contained in the toner is used, a magnet incorporated in the developing sleeve is used to There is a method for conveying and charging the toner. When non-magnetic toner containing no magnetic material is used, there is a method in which a blade and a fur brush are used to forcibly frictionally charge with a developing sleeve, and the toner is adhered to the sleeve and conveyed.

<Image forming apparatus>
Next, the image forming apparatus of the present invention using the electrostatic image developing toner of the present invention will be described.
The image forming apparatus of the present invention includes an image carrier, a developing unit that develops an electrostatic image formed on the image carrier as a toner image with a developer, and a toner image formed on the image carrier. The image forming apparatus includes a transfer unit that transfers onto a transfer body and a fixing unit that fixes a toner image transferred onto the transfer body, and uses the electrostatic image developer of the present invention as the developer.

In this image forming apparatus, for example, the part including the developing unit may have a cartridge structure (process cartridge) that can be attached to and detached from the image forming apparatus main body. As the process cartridge, a developer holding body is used. The process cartridge of the present invention that contains at least the electrostatic image developer of the present invention is preferably used.
Hereinafter, an example of the image forming apparatus of the present invention will be shown, but the present invention is not limited to this. The main parts shown in the figure will be described, and the description of the other parts will be omitted.

  FIG. 1 is a schematic diagram showing a quadruple tandem full-color image forming apparatus. The image forming apparatus shown in FIG. 1 is a first to first electrophotographic method that outputs yellow (Y), magenta (M), cyan (C), and black (K) images based on color-separated image data. Fourth image forming units 10Y, 10M, 10C, and 10K (image forming means) are provided. These image forming units (hereinafter simply referred to as “units”) 10Y, 10M, 10C, and 10K are juxtaposed at a predetermined distance in the horizontal direction. The units 10Y, 10M, 10C, and 10K may be process cartridges that are detachable from the main body of the image forming apparatus.

Above each of the units 10Y, 10M, 10C, and 10K, an intermediate transfer belt 20 as an intermediate transfer member is extended through each unit. The intermediate transfer belt 20 is provided by being wound around a driving roller 22 and a support roller 24 that are in contact with the inner surface of the intermediate transfer belt 20 that are spaced apart from each other from the left to the right in the drawing. It is designed to travel in the direction toward 10K. The support roller 24 is biased in a direction away from the drive roller 22 by a spring or the like (not shown), and a predetermined tension is applied to the intermediate transfer belt 20 wound around both. Further, an intermediate transfer member cleaning device 30 is provided on the side of the image carrier of the intermediate transfer belt 20 so as to face the driving roller 22.
Further, each of the developing devices (developing means) 4Y, 4M, 4C, and 4K of the units 10Y, 10M, 10C, and 10K includes yellow, magenta, cyan, and black contained in the toner cartridges 8Y, 8M, 8C, and 8K. The four color toners can be supplied.

  Since the first to fourth units 10Y, 10M, 10C, and 10K described above have the same configuration, here, the first unit that forms a yellow image disposed on the upstream side in the intermediate transfer belt traveling direction. 10Y will be described as a representative. Note that the second to fourth units are denoted by reference numerals with magenta (M), cyan (C), and black (K) instead of yellow (Y) in the same parts as the first unit 10Y. Description of 10M, 10C, 10K is omitted.

The first unit 10Y has a photoreceptor 1Y that functions as an image holding member. Around the photoreceptor 1Y, an electrostatic charge image is formed by exposing the surface of the photoreceptor 1Y to a predetermined potential with a charging roller 2Y and the charged surface with a laser beam 3Y based on the color-separated image signal. An exposure device 3; a developing device (developing means) 4Y for supplying the charged toner to the electrostatic image and developing the electrostatic image; a primary transfer roller 5Y (primary) for transferring the developed toner image onto the intermediate transfer belt 20; A transfer unit), and a photoconductor cleaning device (cleaning unit) 6Y for removing toner remaining on the surface of the photoconductor 1Y after the primary transfer.
The primary transfer roller 5Y is disposed inside the intermediate transfer belt 20, and is provided at a position facing the photoreceptor 1Y. Further, a bias power source (not shown) for applying a primary transfer bias is connected to each of the primary transfer rollers 5Y, 5M, 5C, and 5K. Each bias power source varies the transfer bias applied to each primary transfer roller under the control of a control unit (not shown).

Hereinafter, an operation of forming a yellow image in the first unit 10Y will be described. First, prior to the operation, the surface of the photoreceptor 1Y is charged to a potential of about −600V to −800V by the charging roller 2Y.
The photoreceptor 1Y is formed by laminating a photosensitive layer on a conductive substrate (volume resistivity at 20 ° C .: 1 × 10 ⁻⁶ Ωcm or less). This photosensitive layer usually has a high resistance (a resistance equivalent to that of a general resin), but has a property that the specific resistance of the portion irradiated with the laser beam changes when irradiated with the laser beam 3Y. Therefore, a laser beam 3Y is output to the surface of the charged photoreceptor 1Y via the exposure device 3 in accordance with yellow image data sent from a control unit (not shown). The laser beam 3Y is applied to the photosensitive layer on the surface of the photoreceptor 1Y, whereby an electrostatic charge image of a yellow print pattern is formed on the surface of the photoreceptor 1Y.

The electrostatic charge image is an image formed on the surface of the photoreceptor 1Y by charging, and the specific resistance of the irradiated portion of the photosensitive layer is lowered by the laser beam 3Y, and the charged charge on the surface of the photoreceptor 1Y flows. On the other hand, this is a so-called negative latent image formed by the charge remaining in the portion not irradiated with the laser beam 3Y.
The electrostatic image formed on the photoreceptor 1Y in this way is rotated to a predetermined development position as the photoreceptor 1Y travels. At this development position, the electrostatic charge image on the photoreceptor 1Y is visualized (developed image) by the developing device 4Y.

  In the developing device 4Y, for example, yellow toner having a volume average particle diameter of 7 μm including at least a yellow colorant, a crystalline resin, and an amorphous resin is accommodated. The yellow toner is triboelectrically charged by being agitated inside the developing device 4Y, and has a charge of the same polarity (negative polarity) as the charged charge on the photoreceptor 1Y, and a developer roll (developer holder). Is held on. As the surface of the photoreceptor 1Y passes through the developing device 4Y, the yellow toner is electrostatically attached to the latent image portion on the surface of the photoreceptor 1Y, and the latent image is developed with the yellow toner. . The photoreceptor 1Y on which the yellow toner image is formed continues to run at a predetermined speed, and the toner image developed on the photoreceptor 1Y is conveyed to a predetermined primary transfer position.

When the yellow toner image on the photoreceptor 1Y is conveyed to the primary transfer, a predetermined primary transfer bias is applied to the primary transfer roller 5Y, and the electrostatic force directed from the photoreceptor 1Y to the primary transfer roller 5Y generates a toner image. The toner image on the photoreceptor 1 </ b> Y is transferred onto the intermediate transfer belt 20. The transfer bias applied at this time is a (+) polarity opposite to the polarity (−) of the toner, and is controlled to about +10 μA by the control unit (not shown) in the first unit 10Y, for example.
On the other hand, the toner remaining on the photoreceptor 1Y is removed and collected by the cleaning device 6Y.

Further, the primary transfer bias applied to the primary transfer rollers 5M, 5C, and 5K after the second unit 10M is also controlled according to the first unit.
Thus, the intermediate transfer belt 20 onto which the yellow toner image has been transferred by the first unit 10Y is sequentially conveyed through the second to fourth units 10M, 10C, and 10K, and the toner images of the respective colors are superimposed and transferred in a multiple manner.

  The intermediate transfer belt 20 onto which the four color toner images have been transferred in multiple layers through the first to fourth units is disposed on the image transfer surface side of the intermediate transfer belt 20 and the support roller 24 in contact with the inner surface of the intermediate transfer belt 20. The secondary transfer roller (secondary transfer means) 26 is connected to a secondary transfer portion. On the other hand, the recording paper (transfer object) P is fed at a predetermined timing into a gap where the secondary transfer roller 26 and the intermediate transfer belt 20 are pressed against each other via a supply mechanism, and a predetermined secondary transfer bias is supported. Applied to the roller 24. The transfer bias applied at this time is a (−) polarity that is the same polarity as the polarity (−) of the toner, and an electrostatic force from the intermediate transfer belt 20 toward the recording paper P is applied to the toner image, and the transfer bias is applied to the intermediate transfer belt 20. The toner image is transferred onto the recording paper P. Note that the secondary transfer bias at this time is determined according to the resistance detected by a resistance detecting means (not shown) for detecting the resistance of the secondary transfer portion, and is voltage-controlled.

Thereafter, the recording paper P is sent to a fixing device (fixing means) 28, where the toner image is heated, and the color-superposed toner image is melted and fixed on the recording paper P. The recording paper P on which the color image has been fixed is carried out toward the discharge unit, and a series of color image forming operations is completed.
The image forming apparatus exemplified above is configured to transfer the toner image onto the recording paper P via the intermediate transfer belt 20, but the present invention is not limited to this configuration, and the toner image is directly transferred from the photoconductor. It may be a structure that is transferred to a recording sheet.

<Process cartridge, toner cartridge>
FIG. 2 is a schematic configuration diagram showing a preferred example of a process cartridge containing the electrostatic charge image developer of the present invention. In the process cartridge 200, a charging roller 108, a developing device 111, a photoconductor cleaning device (cleaning means) 113, an opening 118 for exposure, and an opening 117 for static elimination exposure are attached to a rail 116 together with the photoconductor 107. Are combined and integrated with each other.
The process cartridge 200 is detachable from an image forming apparatus main body including a transfer device 112, a fixing device 115, and other components (not shown). It forms a forming apparatus. Reference numeral 300 denotes a recording sheet.

  The process cartridge shown in FIG. 2 includes a charging device 108, a developing device 111, a cleaning device (cleaning means) 113, an opening 118 for exposure, and an opening 117 for static elimination exposure. Can be selectively combined. In the process cartridge of the present invention, in addition to the photosensitive member 107, from the charging device 108, the developing device 111, the cleaning device (cleaning means) 113, the opening 118 for exposure, and the opening 117 for static elimination exposure. It comprises at least one selected from the group consisting of.

  Next, the toner cartridge of the present invention will be described. The toner cartridge of the present invention is detachably attached to the image forming apparatus, and at least the toner cartridge for storing toner to be supplied to the developing means provided in the image forming apparatus, the toner described above. Toner. The toner cartridge of the present invention only needs to contain at least toner, and may contain developer, for example, depending on the mechanism of the image forming apparatus.

  Therefore, in an image forming apparatus having a configuration in which a toner cartridge can be attached and detached, the storage stability can be maintained even in a toner cartridge whose container is miniaturized by using the toner cartridge containing the toner of the present invention. This makes it possible to achieve low-temperature fixing while maintaining high image quality.

  The image forming apparatus shown in FIG. 1 is an image forming apparatus having a configuration in which the toner cartridges 8Y, 8M, 8C, and 8K can be attached and detached, and the developing devices 4Y, 4M, 4C, and 4K are respectively the developing devices ( And a toner supply pipe (not shown). Further, when the amount of toner stored in the toner cartridge is low, the toner cartridge can be replaced.

  Since the above-described image forming apparatus of the present invention uses the toner of the present invention, low-temperature fixing is possible and the toner can maintain an appropriate triboelectric charge amount. Therefore, it is excellent in energy saving at the time of image formation, and a good image can be formed while preventing the occurrence of toner scattering and the like.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples. In the examples, “parts” and “%” mean “parts by mass” and “% by mass” unless otherwise specified.

<Preparation of each dispersion>
(Amorphous polyester resin particle dispersion (1))
-310 parts of bisphenol A propylene oxide 2 mol adduct-116 parts of terephthalic acid-12 parts of fumaric acid-54 parts of dodecenyl succinic acid-0.05 part of Ti (OBu) ₄ After the above raw materials were put into a heat-dried three-necked flask, The air in the container was depressurized by a depressurization operation, and was further brought into an inert atmosphere with nitrogen gas, and refluxed at 180 ° C. for 5 hours with mechanical stirring. Thereafter, the temperature was gradually raised to 240 ° C. while distilling off the water produced in the reaction system by vacuum distillation. Further, the dehydration condensation reaction was continued at 240 ° C. for 2 hours. When the mixture became viscous, the molecular weight was confirmed by GPC. When the weight average molecular weight reached 19000, the vacuum distillation was stopped and the amorphous polyester resin (1 ) The amorphous polyester resin (1) was amorphous, the glass transition point was 60 ° C., and the acid value was 14 mgKOH / g.

  Next, 100 parts of this amorphous polyester resin (1), 50 parts of ethyl acetate, 25 parts of isopropyl alcohol, and 5 parts of a 10% by mass aqueous ammonia solution were placed in a separable flask, thoroughly mixed and dissolved. While heating and stirring at ° C., ion-exchanged water was added dropwise using a liquid feed pump at a liquid feed speed of 8 g / min. After the liquid became cloudy, the liquid feeding speed was increased to 25 g / min to cause phase inversion, and dropping was stopped when the liquid feeding amount reached 135 parts. Thereafter, the solvent was removed under reduced pressure to obtain an amorphous polyester resin particle dispersion (1). The obtained polyester resin particles had a volume average particle size of 132 nm and the polyester resin particles had a solid content concentration of 38%.

(Crystalline polyester resin dispersion)
In a heat-dried three-necked flask, 230 parts of 1,10-dodecanedioic acid, 160 parts of 1,9-nonanediol, and 0.2 part of dibutyltin oxide as a catalyst were added, and then the air in the three-necked flask was removed by depressurization. The reaction was allowed to proceed under an inert atmosphere by replacing with nitrogen at 180 ° C. for 5 hours by mechanical stirring and refluxing. During the reaction, water produced in the reaction system was distilled off. Thereafter, the temperature was gradually raised to 230 ° C. under reduced pressure, and when the mixture became viscous after stirring for 2 hours, the molecular weight was confirmed by GPC. When the weight average molecular weight reached 29000, the distillation under reduced pressure was stopped and the crystals were crystallized. A functional polyester resin was obtained. The melting point of the crystalline polyester resin was 73 ° C., and the acid value was 12 mgKOH / g.

  Next, 100 parts of this crystalline polyester resin, 35 parts of ethyl acetate, and 35 parts of isopropyl alcohol are placed in a separable flask and thoroughly mixed and dissolved at 75 ° C. Then, 5.5 parts of a 10% aqueous ammonia solution is added dropwise. did. The heating temperature is lowered to 60 ° C., and ion-exchanged water is added dropwise with stirring using a liquid feed pump at a liquid feed speed of 6 g / min. After the liquid becomes cloudy, the liquid feed speed is increased to 25 g / min. When the amount reached 400 parts, dropping of ion-exchanged water was stopped. Thereafter, the solvent was removed under reduced pressure to obtain a crystalline polyester resin dispersion. The obtained crystalline polyester resin particles had a volume average particle size of 136 nm and the polyester resin particles had a solid content concentration of 11.5%.

(Release agent dispersion)
-Ester wax (WEP5, manufactured by NOF Corporation) 50 parts-Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK) 5 parts-Ion-exchanged water 200 parts After dispersing using a homogenizer (IKA: Ultra Tarrax T50), the dispersion is dispersed with a Manton Gorin high-pressure homogenizer (Gorin) to disperse a release agent having an average particle size of 0.24 μm. A release agent dispersion (release agent concentration: 23%) was prepared.

(Colorant dispersion)
・ 100 parts of cyan pigment (Daiichi Seika Co., Ltd., CI Pigment Blue 15: 3, (copper phthalocyanine)) 15 parts of anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen R) Disperse the colorant by mixing 900 parts or more of water, dissolving, and dispersing for 1 hour using a high-pressure impact disperser Ultimateizer (manufactured by Sugino Machine Co., Ltd., HJP30006) to disperse the colorant (cyan pigment). A liquid was prepared. The average particle diameter of the colorant (cyan pigment) in the colorant dispersion was 0.13 μm, and the colorant particle concentration was 25%.

(High acid value dispersant (1))
-JC682 resin (manufactured by John Crill Co., Ltd., α-methylstyrene acrylic acid resin, resin acid value: 238 mg KOH / g, Mw: 1700): 10 parts · 10% aqueous ammonia solution (80% neutralization rate by ammonia with respect to resin acid value) %): 5.78 parts, ion-exchanged water: 34.22 parts The above is mixed and stirred and dissolved in a sealed container while heating in a hot water bath at 80 ° C., and a high acid value with a solid content concentration of 20%. Dispersant (1) was prepared.

(High acid value dispersants (2) to (12))
Similarly to the preparation of the high acid value dispersant (1), the neutralization rate of ammonia with respect to each resin acid value shown in Table 1 was 80%, and each dispersant having a solid content concentration of 20% was prepared. In addition, the synthesis example of resin used other than commercially available is shown below.

-Resin synthesis of high acid value dispersant (4)-
A 4-necked flask equipped with a stirrer, reflux condenser, thermometer, nitrogen gas inlet, and dripping port was charged with 60 parts of n-butanol and maintained at 75 ° C., nitrogen gas was introduced into the flask, and 24 parts of styrene Then, a mixed solution of 16 parts of acrylic acid and 2.0 parts of azobisisobutylnitrile was dropped over 2 hours, and further a copolymerization reaction was performed over 2 hours. After depressurization and desolvation, an acid value of 310 mgKOH / g, A styrene acrylic acid resin having a Mw of 3000 (high acid value dispersant (4) resin) was obtained.

-Resin synthesis of high acid value dispersant (6)-
Styrene having an acid value of 240 mgKOH / g and Mw of 6200 is the same as the resin synthesis of the high acid value dispersant (4) except that 28 parts of styrene, 12 parts of acrylic acid, and 1.6 parts of azobisisobutylnitrile are mixed. An acrylic acid resin (resin of high acid value dispersant (6)) was obtained.

-Resin synthesis of high acid value dispersant (10)-
Styrene having an acid value of 550 mg KOH / g and Mw of 3000 is the same as the resin synthesis of the high acid value dispersant (4) except that 12 parts of styrene, 28 parts of acrylic acid and 2.0 parts of azobisisobutylnitrile are mixed. Acrylic acid resin (resin of high acid value dispersant (10)) was obtained.

-Resin synthesis of high acid value dispersant (11)-
Styrene having an acid value of 150 mgKOH / g and Mw of 3000 is the same as the resin synthesis of the high acid value dispersant (4) except that 32 parts of styrene, 8 parts of acrylic acid, and 2.0 parts of azobisisobutylnitrile are mixed. Acrylic acid resin (resin of high acid value dispersant (11)) was obtained.

-Resin synthesis of high acid value dispersant (12)-
An acid value of 150 mgKOH was obtained in the same manner as the resin synthesis of the high acid value dispersant (4) except that a mixed solution of 50 parts of n-butanol, 35 parts of styrene, 15 parts of acrylic acid, and 3.0 parts of azobisisobutylnitrile was used. / G, Mw 1300 styrene acrylic acid resin (resin of high acid value dispersant (12)) was obtained.

<Creation of carrier>
Three types of ferrite particles having different shape factors (volume average particle diameter: 35 μm) were prepared. The shape factors SF1 were 113, 124, and 144, respectively. A resin obtained by copolymerizing 100 parts of each of these ferrite particles with styrene / methyl methacrylate / isobutyl methacrylate (mass ratio of 30/60/10) (manufactured by Soken Chemical Co., Ltd., molecular weight: 82000) 15 parts of 500 parts of toluene It was dissolved and distilled under reduced pressure in a kneader to prepare a resin-covered carrier. The shape factor SF1 of each carrier was 113, 126, and 146.

First, a case where only the amorphous polyester resin is included as the binder resin will be described.
<Example A1>
(Manufacture of toner)
Amorphous polyester resin particle dispersion (1) 302.6 parts Colorant dispersion (1) 48.0 parts Anionic surfactant (dowfax 2A1, 20% aqueous solution) 11.5 parts Release agent dispersion Liquid 80.2 parts ・ High acid value dispersant (1) JC682 resin (“α-methylstyrene acrylic acid resin” acid value: 238 mg KOH / g, Mw: 1700) manufactured by Jonkrill Co., Ltd. 30 parts of aqueous ammonia solution 30 parts pH meter The polyester resin particle dispersion (1), the anionic surfactant, and 631 parts of ion-exchanged water among the above raw materials are placed in a polymerization vessel equipped with a stirring blade and a thermometer, and stirred for 15 minutes at 200 rpm. The surfactant was blended with the amorphous polyester resin particle dispersion (1). Subsequently, the high acid value dispersant (1) was added, and further stirred and thoroughly blended. Then, the colorant dispersion and the release agent dispersion were added and mixed, and then 0.3 M of the raw material mixture was added to the raw material mixture. An aqueous nitric acid solution was added to adjust the pH to 2.7. Subsequently, 100 parts of 10% aqueous solution of aluminum sulfate was added dropwise as a flocculant while applying a shearing force at 1000 rpm with Ultraturrax (manufactured by IKA Japan). In addition, since the viscosity of the raw material mixture increases during the dropping of the flocculant, the dropping speed was reduced when the viscosity increased, so that the flocculant was not biased to one place. When the dropping of the flocculant was completed, the rotational speed was further increased to 6000 rpm and the mixture was stirred for 5 minutes to sufficiently mix the flocculant and the raw material mixture.

  Subsequently, the raw material mixture was stirred at 550 to 650 rpm while being heated to 30 ° C. with a mantle heater. After stirring for 60 minutes, it was confirmed that the primary particle diameter was stably formed using a Coulter Multisizer II type (aperture diameter: 50 μm, manufactured by Beckman-Coulter). The temperature was raised to 45 ° C at a rate of 1 minute. The growth of the agglomerated particles is confirmed at any time using a Coulter Multisizer type II, and the agglomeration temperature and the number of rotations of stirring are changed depending on the agglomeration speed.

  On the other hand, 75.4 parts of ion-exchanged water and 5.6 parts of an anionic surfactant (dowfax 2A1, 20% aqueous solution) were added to 147.4 parts of the amorphous polyester resin particle dispersion (1) for coating aggregated particles. In addition, a coating resin particle dispersion (1) prepared in advance and adjusted to pH 2.7 was prepared. When the aggregated particles grew to 5.0 μm in the aggregation step, the coating resin particle dispersion (1) was added and held for 10 minutes with stirring. Thereafter, in order to stop the growth of the coated aggregated particles (adhered particles), 16.7 parts of an EDTA aqueous solution (manufactured by Killes Co., Ltd., Kirest 40 diluted to 12% with ion-exchanged water) and 1M hydroxylated Sodium aqueous solution was added in order, and the pH of the raw material mixture was controlled to 6.5. Subsequently, in order to fuse the aggregated particles, the temperature was raised to 85 ° C. at a temperature raising rate of 1 ° C./min while adjusting the pH to 6.5. After confirming that the aggregated particles were fused with an optical microscope, ice water was injected and rapidly cooled at a cooling rate of 100 ° C./min.

  Next, the pH of the slurry after cooling the obtained particles with 1N aqueous sodium hydroxide solution was adjusted to 9.0, stirred for 20 minutes, and sieved once with a 20 μm mesh. Thereafter, approximately 10 times the amount of warm water (50 ° C.) was added to the solid content, and the mixture was stirred for 20 minutes while adjusting the pH to 9.0 again, washed with warm alkali, and once filtered. Further, the solid content remaining on the filter paper is dispersed in the slurry and washed three times with 40 ° C. warm water, and further washed with acid at 40 ° C. while adding a 0.3N nitric acid aqueous solution to the slurry to 4.0. went. Then, finally, the mixture was washed with stirring in warm ion-exchanged water at 40 ° C. and dried to obtain toner base particles (A1) having a volume average particle diameter of 6.4 μm.

  To the toner base particles (A1) obtained above, silica fine powder (particle diameter: 50 nm) and titania fine powder (particle diameter: 40 nm) as external additives were added in an amount of 0.9 parts with respect to 100 parts of the toner base particles. And 0.6 part were added and mixed with a Henschel mixer to obtain a toner (A1) for developing an electrostatic latent image.

(Measurement of toner physical properties)
-Measurement of toner shape factor-
The shape factor of the toner was measured using a flow particle analyzer FPIA2100 (manufactured by Hosokawa Micron Corporation) under the following conditions.
Pretreatment: Dilute with 300 ml of pure water to 300 mg of stock solution, and disperse for 5 minutes with ultrasound Measurement conditions: mode HPF measurement mode
Analytical amount 0.35μL
Particle count 1500 to 5000 count Analysis condition: particle size limited range 0.60 to 10.05 μm (equivalent circle diameter)
Circularity limited range 0.40 to 1.00

-Measurement of aluminum content and sodium content-
Using a fluorescent X-ray analyzer (XRF-1500, manufactured by Shimadzu Corporation), a disk having a toner amount of 0.125 g was molded, and all elements measurable by the method described above were measured.

-Measurement of toner moisture content-
After 2 g of toner was left in an environment of 28 ° C. and humidity 85% RH for 72 hours, the amount of water evaporated at a heating temperature of 150 ° C. was measured using a halogen moisture analyzer (manufactured by METTLER TOLEDO). Rate (%).

(Evaluation of toner)
-Evaluation of image quality and actual machine characteristics-
8 parts of the obtained toner and 100 parts of resin-coated ferrite particles (volume average particle diameter 35 μm, shape factor SF1: 126) are mixed to prepare a two-component developer, which is prepared at a temperature of 28 ° C. and a humidity of 85%. Using a commercially available electrophotographic copying machine (Fuji Xerox Co., Ltd. Docu Center Color a450), copy 1000 copies at an image density of 5%, leave it for 3 days, copy 1 copy again, (1) Image quality and (2) Photoconductor contamination (cleaning property) were evaluated.

(1) The image quality was evaluated by visually observing the copied image again, and graded the image density reproducibility, fogging, and jumping from the following viewpoints.
G1: No flicker is observed in the non-image area, which is good.
G2: Although scattering is scattered in the non-image part, there is no problem.
G3: Although fog is confirmed over the entire non-image area, it is within an allowable range.
G4: Not only the image portion and the non-image portion, but the overall fog is confirmed and is not allowed.

(2) Regarding the photoconductor contamination (cleanability), the photoconductor was taken out and the filming occurrence state was visually observed.
G1: Filming cannot be confirmed.
G2: Although there is filming, there is no problem in image quality.
G3: Filming is confirmed and the image quality is affected.

-Fixability evaluation-
5 parts of the obtained toner and 100 parts of resin-coated ferrite particles (volume average particle size 35 μm) are mixed to prepare a two-component developer, which is converted into a commercially available electrophotographic copying machine remodeling machine (manufactured by Fuji Xerox Co., Ltd.). An image was obtained using Docu Center Color a450 modified so that it could be taken out before image fixing, and an unfixed image was obtained.
Next, using a belt pressure (nip) type external fixing device, (3) image fixability (minimum fixing temperature) while gradually increasing the fixing temperature from 90 ° C. to 200 ° C. in steps of 5 ° C. 4) The hot offset temperature was evaluated.

Specifically, (3) image fixability (minimum fixing temperature) is such that after fixing an unfixed solid image (25 mm × 25 mm), the image portions are bent by aligning both ends of the paper with fingers, A cylindrical object having a height of 50 mm, a diameter of 70 mm, and a total weight of 800 g is applied at a speed of 200 mm / sec. The fixing temperature at which the width of the image defect portion at that portion is 0.2 mm or less was defined as the minimum fixing temperature.
Further, (4) the hot offset temperature was set to the lowest temperature at which the corresponding white paper sheet was visually confirmed after one round of the fixing belt surface after fixing the unfixed image. The fixing stable temperature range was a temperature range 5 ° C. inside from the minimum fixing temperature and the hot offset occurrence temperature.

  Various characteristics of the obtained toner are shown in Tables 1 and 2. Tables 3 and 4 show the measurement results and evaluation results of the toner physical properties shown in Tables 1 and 2.

<Example A2>
In the production of the toner of Example A1, instead of the raw material high acid number dispersant (1), high acid number dispersant (2) (GSA502 (“α-methylstyrene acrylic acid resin” Mw: Gifu Serak Manufacturing Co., Ltd.): 5,000 acid value: 300 mg KOH / g) solid content 20% ammonium aqueous solution) 25 parts, and the aggregation stopping pH and coalescence starting pH were set to 7.0. Then, fusion, washing and drying were performed to obtain toner mother particles (A2) having a volume average particle diameter of 6.5 μm.

Using the toner base particles (A2), a toner was prepared according to Example A1, and the toner physical properties were measured and the toner was evaluated according to Example A1.
The results are summarized in Tables 1 to 4.

<Example A3>
(Manufacture of toner)
Amorphous polyester resin particle dispersion (1) 302.6 parts Colorant dispersion (1) 48.0 parts Anionic surfactant (dowfax 2A1, 20% aqueous solution) 11.5 parts Release agent dispersion Liquid 80.2 parts In a polymerization kettle equipped with a pH meter, a stirring blade, and a thermometer, among the above raw materials, the polyester resin particle dispersion (1), an anionic surfactant, and 631 parts of ion-exchanged water are added. The surfactant was blended with the amorphous polyester resin particle dispersion (1) while stirring at 200 rpm for 15 minutes. Subsequently, the colorant dispersion and the release agent dispersion were added and mixed, and then a 0.3 M nitric acid aqueous solution was added to the raw material mixture to adjust the pH to 2.7. Subsequently, 27 parts of a 10% nitric acid aqueous solution of polyaluminum chloride as a flocculant was dropped while applying a shearing force at 1000 rpm with Ultraturrax (manufactured by IKA Japan). In addition, since the viscosity of the raw material mixture increases during the dropping of the flocculant, the dropping speed was reduced when the viscosity increased, so that the flocculant was not biased to one place. When the dropping of the flocculant was completed, the rotational speed was further increased to 6000 rpm and the mixture was stirred for 5 minutes to sufficiently mix the flocculant and the raw material mixture.

  Subsequently, the raw material mixture was stirred at 550 to 650 rpm while being heated to 30 ° C. with a mantle heater. After stirring for 60 minutes, it was confirmed that the primary particle diameter was stably formed using a Coulter Multisizer II type (aperture diameter: 50 μm, manufactured by Beckman-Coulter). The temperature was raised to 45 ° C at a rate of 1 minute. The growth of the agglomerated particles is confirmed at any time using a Coulter Multisizer type II, and the agglomeration temperature and the number of rotations of stirring are changed depending on the agglomeration speed.

  On the other hand, 75.4 parts of ion-exchanged water and 5.6 parts of an anionic surfactant (dowfax 2A1, 20% aqueous solution) were added to 147.4 parts of the amorphous polyester resin particle dispersion (1) for coating aggregated particles. In addition, a coating resin particle dispersion (1) prepared in advance and adjusted to pH 2.7 was prepared. When the agglomerated particles grow to 5.0 μm in the agglomeration step, the coating resin particle dispersion (1) is added and held for 10 minutes with stirring. Here, the high acid value dispersant (3) (Gifu Ceramics) GSM301 “Styrene maleic acid resin” Mw: 3000 Acid value: 470 mg KOH / g) 25 parts solid content 20% ammonium aqueous solution) was added, and then the growth of the coated aggregated particles (adherent particles) was stopped. 16.7 parts of EDTA (12% chillest 40 aqueous solution) and 1M aqueous sodium hydroxide solution were sequentially added to control the pH of the raw material mixture to 6.5. Subsequently, in order to fuse the aggregated particles, the temperature was raised to 85 ° C. at a temperature raising rate of 1 ° C./min while adjusting the pH to 6.5. Even after reaching 85 ° C., the pH was adjusted to 6.5 in order to proceed with the fusion, and after confirming that the aggregated particles were fused with an optical microscope, ice water was injected and rapidly cooled at a cooling rate of 100 ° C./min. .

Next, washing and drying were performed according to Example A1 to obtain toner base particles (A3) having a volume average particle size of 6.6 μm.
Using the toner base particles (A3), a toner was prepared according to Example A1, and the toner physical properties were measured and the toner was evaluated according to Example A1.
The results are summarized in Tables 1 to 4.

<Example A4>
In the production of the toner of Example A1, instead of the high acid value dispersant (1), the high acid value dispersant (4) (styrene acrylic acid resin (weight molecular weight: 3100, acid value: 310 mgKOH / g) solid content concentration Except for using 25 parts of a 20% aqueous ammonia solution), agglomerated particles were prepared according to Example A1, and the agglomerated particles were coated, fused, washed and dried, and a toner base having a volume average particle size of 6.0 μm Particles (A4) were obtained.

Using the toner base particles (A4), a toner was prepared according to Example A1, and the toner physical properties were measured and the toner was evaluated according to Example A1.
The results are summarized in Tables 1 to 4.

<Example A5>
In the production of the toner of Example A3, instead of the high acid value dispersant (3), the high acid value dispersant (5) (GSM601 “Styrene maleic acid resin” Mw: 6000, acid value: 470 mg KOH / manufactured by Gifu Seratsk Co., Ltd.) g, solid content 20% aqueous ammonia solution) 25 parts were used, and agglomerated particles were produced according to Example A3, except that the pH for stopping aggregation and the pH for starting coalescence were 7.0. The particles were coated, fused, washed and dried to obtain toner base particles (A5) having a volume average particle size of 5.8 μm.

Using the toner base particles (A5), a toner was prepared according to Example A1, and the physical properties of the toner and the evaluation of the toner were performed according to Example A1.
The results are summarized in Tables 1 to 4.

<Example A6>
In the production of the toner of Example A1, instead of the high acid value dispersant (1), the high acid value dispersant (6) (styrene acrylic acid (acid value: 240 mg KOH / g, Mw: 6200), solid content concentration 20 %) 30 parts were used, and the aggregated particles were prepared in accordance with Example A1 except that the aggregation stop pH and the coalescence start pH were 7.0, and the aggregated particles were coated, fused, and washed. Drying was performed to obtain toner base particles (A6) having a volume average particle diameter of 6.0 μm.

Using the toner base particles (A6), a toner was prepared according to Example A1, and the toner physical properties were measured and the toner was evaluated according to Example A1.
The results are summarized in Tables 1 to 4.

<Example A7>
In the production of the toner of Example A3, instead of the high acid value dispersant (3), the high acid value dispersant (7) GS151 ("Styrene maleic acid resin" Mw: 1500, manufactured by Gifu Seratsk), acid value: 470 mgKOH / g, solid content concentration 20% ammonia aqueous solution) Except for using 25 parts, agglomerated particles were prepared according to Example A3, and the agglomerated particles were coated, fused, washed and dried, and the volume average particle size 6 Toner base particles (A7) of 0.0 μm were obtained.

Using the toner base particles (A7), a toner was prepared according to Example A1, and the toner physical properties were measured and the toner was evaluated according to Example A1.
The results are summarized in Tables 1 to 4.

<Example A8>
In the production of the toner of Example A3, instead of the high acid value dispersant (3), the high acid value dispersant (8) (GS603 (“Styrene Maleic Resin”, Mw: 6000, manufactured by Gifu Seratec Co., Ltd.) g, a solid content 20% aqueous ammonia solution) 30 parts are used except that aggregated particles are prepared in accordance with Example A3, and the aggregated particles are coated, fused, washed, and dried to obtain a volume average particle size of 6. 0 μm toner base particles (A8) were obtained.

Using the toner base particles (A8), a toner was prepared according to Example A1, and the toner physical properties were measured and the toner was evaluated according to Example A1.
The results are summarized in Tables 1 to 4.

<Example A9>
In the production of the toner of Example A1, in place of the high acid value dispersant (1), the high acid value dispersant (9) (JC680 resin ("styrene acrylate resin" Mw: 4500, manufactured by John Krill), acid value: In order to produce agglomerated particles according to Example A1 except that 30 parts (215 mg KOH / g, solid content 20% ammonia aqueous solution) were used, and then to stop the growth of the coated agglomerated particles (adhered particles), EDTA (12% Kyrest 40 aqueous solution) 16.7 parts and 1M aqueous sodium hydroxide solution were added in order, and the pH of the raw material mixture was controlled to 7.0. Toner mother particles (A9) having an average particle diameter of 6.2 μm were obtained.

Using the toner base particles (A9), a toner was prepared according to Example A1, and the toner physical properties were measured and the toner was evaluated according to Example A1.
The results are summarized in Tables 1 to 4.

<Examples A10 and A11>
In the production of the toner of Example A1, when determining the end point of the fusion while observing the fused state of the aggregated particles with an optical microscope, after the fusion temperature reaches 85 ° C., the sample is sequentially sampled with a shape factor of 0. The toner was granulated in accordance with Example A1 except that the fusion was stopped and rapidly cooled at 95, and the toner was granulated in accordance with Example A1 and washed and dried in accordance with Example A1 to obtain toner base particles (A10 having a volume average particle diameter of 6.7 μm). ) The shape factor of the toner base particles (A10) was measured by the method described later and found to be 0.95.
Similarly, after reaching the fusion temperature of 85 ° C., sampling is performed sequentially over time, and when the shape factor becomes 0.98, the fusion is stopped and rapidly cooled, and the toner is granulated according to Example A1 and further washed. The toner mother particles (A11) having a volume average particle diameter of 6.0 μm were also obtained by drying according to Example A1. The shape factor of the toner base particles (A11) was 0.98 when measured by the method described later.

Using the toner base particles (A10, A11), a toner was prepared according to Example A1, and the physical properties of the toner and the evaluation of the toner were performed according to Example A1.
The results are summarized in Tables 1 to 4.

<Examples A12 and A13>
In the evaluation of the toner of Example A4, agglomerated particles were prepared in accordance with Example A4, except that 8.3 parts of EDTA (12% querest 40 aqueous solution) was added, and the aggregated particles were coated and fused. Further, washing and drying were performed to obtain toner base particles (A12) having a volume average particle diameter of 6.0 μm. Similarly, except that 25 parts of EDTA (12% Kirest 40 aqueous solution) was used, an aggregated particle was produced in accordance with Example A4, and the aggregated particle was coated, fused, washed, and dried. Toner mother particles (A13) having a volume average particle diameter of 6.0 μm were obtained.

Using the toner base particles (A12, A13), a toner was prepared according to Example A1, and the physical properties of the toner and the evaluation of the toner were performed according to Example A1.
The results are summarized in Tables 1 to 4.

<Example A14>
In the evaluation of the toner of Example A1, a developer was prepared according to Example A1 except that the resin-coated ferrite particles (volume average particle diameter 35 μm, shape factor SF1: 146) were used as a carrier. The actual machine characteristics were evaluated.
The results are summarized in Tables 1 to 4.

<Example A15>
In the evaluation of the toner of Example A1, a developer was prepared according to Example A1 except that the resin-coated ferrite particles (volume average particle diameter 35 μm, shape factor SF1: 113) were used as a carrier. The actual machine characteristics were evaluated.
The results are summarized in Tables 1 to 4.

<Comparative Example A1>
In the production of the toner of Example A1, granulation was performed according to Example A1, except that the high acid value dispersant (1) was not used. However, in the coalesced particle fusion step, particle growth cannot be controlled, resulting in coarse powder, and toner particles cannot be recovered.

<Comparative Example A2>
In Example A1, except that the high acid value dispersant (1) was not used, aggregated particles were produced and coated with the aggregated particles under the same conditions as in Example A1. Thereafter, in order to stop the growth of the coated aggregated particles (adhered particles), a 1M aqueous sodium hydroxide solution was added to control the pH of the raw material mixture to 8.0. Subsequently, in order to fuse the aggregated particles, the temperature was raised to 85 ° C. at a temperature raising rate of 1 ° C./min while adjusting the pH to 8.0. After confirming that the aggregated particles were fused with an optical microscope, ice water was injected and rapidly cooled at a cooling rate of 100 ° C./min.
Thereafter, washing and drying were performed according to Example A1 to obtain toner base particles (a2) having a volume average particle diameter of 6.0 μm.

Using the toner base particles (a2), a toner was prepared according to Example A1, and the physical properties of the toner and the evaluation of the toner were performed according to Example A1.
The results are summarized in Tables 1 to 4.

<Comparative Example A3>
In Example A1, except that the high acid value dispersant (1) was not used, aggregated particles were produced and coated with the aggregated particles under the same conditions as in Example A1. Thereafter, in order to stop the growth of the coated aggregated particles (adherent particles), a 1M aqueous sodium hydroxide solution was added to control the pH of the raw material mixture to 9.0. Subsequently, in order to fuse the aggregated particles, the temperature was raised to 85 ° C. at a temperature raising rate of 1 ° C./min while adjusting the pH to 9.0. After confirming that the aggregated particles were fused with an optical microscope, ice water was injected and rapidly cooled at a cooling rate of 100 ° C./min.
Thereafter, washing and drying were performed according to Example A1 to obtain toner base particles (a3) having a volume average particle size of 6.3 μm.

Using the toner base particles (a3), a toner was prepared according to Example A1, and the toner physical properties were measured and the toner was evaluated according to Example A1.
The results are summarized in Tables 1 to 4.

<Comparative Example A4>
In Example A1, aggregated particles were prepared according to Example A1 except that 10 parts of a 20% aqueous ammonium acetate solution was used instead of the high acid value dispersant (1), and the aggregated particles were coated. . However, the growth of the coated aggregated particles (adhered particles) is not stopped and the particle size growth due to the temperature rise in the coalescence process cannot be controlled, resulting in coarse powder, and the toner particles cannot be recovered. It was.

<Comparative Example A5>
In Example A1, instead of the high acid value dispersant (1), 40 parts of “a solution obtained by dissolving 20 parts of sodium oleate (Nonsar ON-A, manufactured by NOF Corporation) in 100 parts of ion-exchanged water” is used. Except for this, aggregated particles were prepared and coated with the aggregated particles according to Example A1. However, the growth of the coated aggregated particles (adhered particles) is not stopped and the particle size growth due to the temperature rise in the coalescence process cannot be controlled, resulting in coarse powder, and the toner particles cannot be recovered. It was.

<Comparative Example A6>
In Example A1, instead of the high acid value dispersant (1), “a solution obtained by dissolving 20 parts of industrial soap (NS soap (semi-cured beef tallow fatty acid soda soap), manufactured by Kao Corporation) in 100 parts of ion-exchanged water” Except for using 40 parts of, agglomerated particles were prepared and coated with agglomerated particles according to Example A1. However, the growth of the coated aggregated particles (adhered particles) is not stopped and the particle size growth due to the temperature rise in the coalescence process cannot be controlled, resulting in coarse powder, and the toner particles cannot be recovered. It was.

<Comparative Example A7>
In Example A1, instead of the high acid value dispersant (1), A-6330 manufactured by Toagosei Co., Ltd. (“polyacrylic acid maleic acid sodium salt” acid value: 770 mg KOH / g, Mw: 10,000, solid content concentration 40%) Aggregated particles were prepared and coated with the agglomerated particles according to Example A1 except that 10 parts were used. However, the growth of the coated aggregated particles (adhered particles) is not stopped and the particle size growth due to the temperature rise in the coalescence process cannot be controlled, resulting in coarse powder, and the toner particles cannot be recovered. It was.

<Comparative Example A8>
In Example A1, instead of the high acid value dispersant (1), manufactured by Toagosei Co., Ltd., A-210 (“polysodium acrylate” acid value: 597 mg KOH / g Mw: 2000, solid content concentration: 40%) 10 Aggregated particles were prepared and coated with the agglomerated particles according to Example A1 except that the part was used. However, it was not possible to control the growth of the coated aggregated particles (adhered particles) thereafter, and the particle size growth due to the temperature rise in the fusion process, and the particle size was increased to 3 μm, and stable particle size control could not be performed. .

<Comparative Example A9>
In Example A1, instead of the high acid value dispersant (1), manufactured by Toagosei Co., Ltd., A6013 (“sodium polyacrylate sulfonate”, acid value: 750 mg KOH / g, Mw: 10,000, solid content concentration: 40% ) Was used in the same manner as in Example A1 except that 10 parts were used, and the aggregated particles were coated. Thereafter, in order to stop the growth of the coated aggregated particles (adherent particles), 16.7 parts of EDTA (12% chillest 40 aqueous solution) and 1M aqueous sodium hydroxide solution were added in order, and the pH of the raw material mixture was adjusted to 7.0. Controlled. However, it is impossible to control the growth of the coated aggregated particles (adhered particles) thereafter and the particle size growth due to the temperature rise in the fusion process, the particle size becomes coarse as 2.5 μm, and the particle size distribution deteriorates. Stable particle size control was not possible.

<Comparative Example A10>
In Example A1, instead of the high acid value dispersant (1), A30SL ("Ammonium polyacrylate", acid value: 630 mg KOH / g, Mw: 6000, solid content concentration: 40%) manufactured by Toagosei Co., Ltd. Except that 10 parts of was used, aggregated particles were prepared and coated with the aggregated particles according to Example A1. However, the growth of the coated agglomerated particles (adhered particles) after that cannot be controlled and the particle size growth due to the temperature rise in the fusion process cannot be controlled, the particle size becomes as large as 2.8 μm, and the particle size distribution deteriorates. Stable particle size control was not possible.

<Comparative Example A11>
In Example A1, instead of the high acid value dispersant (1), the high acid value dispersant (10) (styrene acrylic acid resin (Mw: 3100, acid value: 550 mg KOH / g) solid content concentration 20% aqueous solution) 20 Aggregated particles were prepared and coated with the agglomerated particles according to Example A1 except that the part was used. However, the growth of the coated aggregated particles (adhered particles) after that cannot be controlled and the particle size growth due to the temperature rise in the fusion process cannot be controlled, the particle size becomes coarser to 2.0 μm, and the particle size distribution deteriorates. Stable particle size control was not possible.

<Comparative Example A12>
In Example A1, instead of the high acid value dispersant (1), the high acid value dispersant (11) (styrene acrylic acid resin (Mw: 2900, acid value: 150 mg KOH / g) 20% solids concentration aqueous solution) 40 Aggregated particles were prepared and coated with the agglomerated particles according to Example A1 except that the part was used. Thereafter, in order to stop the growth of the coated aggregated particles (adherent particles), 16.7 parts of EDTA (12% chillest 40 aqueous solution) and 1M aqueous sodium hydroxide solution were added in order, and the pH of the raw material mixture was adjusted to 7.0. Controlled. However, the growth of the coated aggregated particles (adhered particles) after that cannot be controlled and the particle size growth due to the temperature rise in the fusion process cannot be controlled, the particle size becomes as large as 2.3 μm, and the particle size distribution deteriorates. Stable particle size control was not possible.

<Comparative Example A13>
In Example A1, instead of the high acid value dispersant (1), the high acid value dispersant (12) (styrene acrylic acid resin (Mw: 1300, acid value: 300 (synthesis example) solid content concentration 20%) 25 The agglomerated particles were produced and coated with the agglomerated particles according to Example A1 except that the part was used, but the growth of the coated agglomerated particles (adhered particles) was stopped and the temperature increased in the fusion process. It was impossible to control the particle size growth due to the particle size, the particle size became as large as 2.0 μm, the particle size distribution deteriorated, and stable particle size control could not be performed.

<Comparative Examples A14 and 15>
In the production of the toner of Example A4, except that EDTA (12% Kyrest 40 aqueous solution) is not used, aggregated particles are produced according to Example A4, and the aggregated particles are coated, fused, washed, and dried. Toner mother particles (a14) having a volume average particle diameter of 6.5 μm were obtained. Similarly, agglomerated particles were prepared according to Example A4, except that 33.3 parts of EDTA (12% chillest 40 aqueous solution) was used, and the agglomerated particles were coated, fused, washed and dried. Then, toner mother particles (a15) having a volume average particle diameter of 6.0 μm were obtained.

Using the toner base particles (a14, a15), a toner was prepared according to Example A1, and the physical properties of the toner and the evaluation of the toner were performed according to Example A1.
The results are summarized in Tables 1 to 4.

<Comparative Example A16>
In the production of the toner of Example A1, when determining the end point of the fusion while observing the fusion state of the aggregated particles with an optical microscope, after reaching the fusion temperature of 85 ° C., sampling is performed sequentially with time, and the shape factor is set to 0. The toner was granulated according to Example A1 except that the fusion was stopped and rapidly cooled at 94, followed by washing and drying according to Example A1, and toner base particles (a16 having a volume average particle diameter of 6.6 μm). ) The shape factor of the toner base particles (a16) was measured by the method described later to be 0.945.

Using the toner base particles (a16), a toner was prepared according to Example A1, and the toner physical properties were measured and the toner was evaluated according to Example A1.
The results are summarized in Tables 1 to 4.
In the table, the solid content addition amount and the chelating agent addition amount of the dispersant are each shown as a solid content ratio with respect to the toner solid content.

From the results shown in Tables 1 to 4, the Examples showed good characteristics without problems with respect to good cleaning properties, image quality, and other secondary obstacles.
On the other hand, for example, when the high acid value dispersant of the comparative example is not used, the particle growth of the toner cannot be controlled, or even when the toner is granulated, the pH for controlling the particle diameter growth is 8.0 to 8.0. Even when the toner particle growth can be controlled by increasing the value to 9.0, the moisture content of the toner increases, which adversely affects the image quality characteristics and the photoreceptor contamination in an actual machine under high temperature and high humidity. As a result.

Next, a case where an amorphous polyester resin and a crystalline polyester resin are included as the binder resin will be described.
<Example B1>
(Manufacture of toner)
-Amorphous polyester resin particle dispersion (1) 226.6 parts-Crystalline polyester resin dispersion 119.0 parts-Colorant dispersion 48.0 parts-Anionic surfactant (Dowfax 2A1, manufactured by Dow Chemical Co., Ltd.) 20% aqueous solution) 11.5 parts, release agent dispersion 80.2 parts, high acid value dispersant (4) (styrene acrylic acid resin, Mw: 3100, acid value: 310, solid content concentration: 20%) 25 Part Among the above raw materials, a polyester resin particle dispersion (1), an anionic surfactant, and 340 parts of ion-exchanged water are placed in a polymerization kettle equipped with a pH meter, a stirring blade, and a thermometer, and 200 minutes at 200 rpm. While stirring, the surfactant was blended with the polyester resin particle dispersion (1). Subsequently, the high acid value dispersant (4) was added, and further stirred and thoroughly blended. Then, the colorant dispersion and the release agent dispersion were added and mixed, and then 0.3 M of the raw material mixture was added to the raw material mixture. An aqueous nitric acid solution was added to adjust the pH to 2.7. Next, 27 parts of a 10% nitric acid aqueous solution of polyaluminum chloride as a flocculant was dropped while applying a shearing force at 1000 rpm with Ultraturrax (manufactured by IKA Japan). In addition, since the viscosity of the raw material mixture increases during the dropping of the flocculant, the dropping speed was reduced when the viscosity increased, so that the flocculant was not biased to one place. When the dropping of the flocculant was completed, the rotational speed was further increased to 6000 rpm and the mixture was stirred for 5 minutes to sufficiently mix the flocculant and the raw material mixture.

  Subsequently, the raw material mixture was stirred at 550 to 650 rpm while being heated to 30 ° C. with a mantle heater. After stirring for 60 minutes, it was confirmed that the primary particle diameter was stably formed using a Coulter Multisizer type II (aperture diameter: 50 μm; manufactured by Beckman-Coulter), and then 0.5 ° C. for growing aggregated particles. The temperature was raised to 45 ° C. at a rate of 1 minute. The growth of the aggregated particles is confirmed at any time using a Coulter counter. The aggregation temperature and the number of rotations of stirring were changed depending on the aggregation rate.

  On the other hand, for coating the aggregated particles, 147.4 parts of the amorphous polyester resin particle dispersion (1), 75.5 parts of ion-exchanged water, 4.2 parts of an anionic surfactant (dowfax 2A1, 20% aqueous solution) and Then, 1.8 parts of a high acid value dispersant (11) was added and mixed to prepare a coating resin particle dispersion (1) previously adjusted to pH 2.7. When the aggregated particles grew to 5.0 μm in the aggregation step, the coating resin particle dispersion (1) was added and held for 10 minutes with stirring. Thereafter, in order to stop the growth of the coated aggregated particles (adhered particles), 16.7 parts of EDTA (12% chillest 40 aqueous solution) and 1M aqueous sodium hydroxide solution were added in order, and the pH of the raw material mixture was adjusted to 6.5. Controlled. Subsequently, in order to fuse the aggregated particles, the temperature was raised to 75 ° C. at a temperature raising rate of 1 ° C./min while adjusting the pH to 6.5. After confirming that the aggregated particles were fused with an optical microscope, ice water was injected and rapidly cooled at a cooling rate of 100 ° C./min.

  Next, for the purpose of washing the obtained particles, the pH of the slurry after cooling with 1N aqueous sodium hydroxide solution was adjusted to 9.0, stirred for 20 minutes, and sieved once with a 20 μm mesh. Thereafter, approximately 10 times the amount of warm water (50 ° C.) was added to the solid content, and the mixture was stirred for 20 minutes while adjusting the pH to 9.0 again, washed with warm alkali, and once filtered. Further, the solid content remaining on the filter paper is dispersed in the slurry and washed three times with 40 ° C. warm water, and further washed with acid at 40 ° C. while adding a 0.3N nitric acid aqueous solution to the slurry to 4.0. went. Then, finally, the mixture was washed with stirring in warm water of ion exchange water at 40 ° C. and dried to obtain toner base particles (B1) having a volume average particle diameter of 6.1 μm.

  To the toner base particles (B1) obtained above, silica fine powder (particle diameter: 50 nm) and titania fine powder (particle diameter: 40 nm) as external additives were added in an amount of 0.9 parts with respect to 100 parts of the toner base particles. And 0.6 part were added, and mixed with a Henschel mixer to obtain an electrostatic latent image developing toner (B1).

(Evaluation of toner)
-Evaluation of image quality and actual machine characteristics-
8 parts of the obtained toner and 100 parts of resin-coated ferrite particles (volume average particle diameter 35 μm, shape factor SF1: 126) are mixed to prepare a two-component developer, which is prepared at a temperature of 28 ° C. and a humidity of 85%. Using a commercially available electrophotographic copying machine (Fuji Xerox Co., Ltd., Docu Center Color a450) in a high-temperature and high-humidity environment, copy 1000 copies, leave them for 3 days, and then copy 1 copy again. (1) Image quality , (2) Photoconductor contamination (cleaning property) and (3) developer charge amount were evaluated.

(1) The image quality was evaluated by visually observing the copied image again, and graded the image density reproducibility, fogging, and jumping from the following viewpoints.
G1: Although a flicker is observed in a very small part of the non-image part, it is at a level with no problem.
G2: Spattering is scattered in the non-image area, which may hinder repeated use.
G3: The fog spreads over the entire non-image area.
G4: Not only the image portion and the non-image portion, but the fog is spread as a whole, and is an unacceptable level.

  (2) Regarding the photoconductor contamination (cleanability), the photoconductor was taken out and the filming occurrence state was visually observed.

  (3) As for the charge amount of the developer, the developer was collected from the developing sleeve after copying 1000 sheets in the environment of 28 ° C./85% RH and after copying again after standing for 3 days. The toner charge amount in the developer was measured using a blow-off charge amount measuring device (TB200, manufactured by Toshiba Chemical Corporation).

-Fixability evaluation-
5 parts of the obtained toner and 100 parts of resin-coated ferrite particles (volume average particle diameter: 35 μm) are mixed to prepare a two-component developer, which is converted into a commercially available electrophotographic copying machine remodeling machine (Fuji Xerox Co., Ltd.). An unfixed image was obtained by using Docu Center Color a450 manufactured by the same company and modified so that it could be taken out before image fixing.
Next, using a belt pressure (nip) type external fixing machine, (4) image fixability (minimum fixing temperature) while gradually increasing the fixing temperature from 90 ° C. to 220 ° C. in steps of 5 ° C. 5) Hot offset temperature and (6) glossiness were evaluated.

Specifically, (4) image fixability (minimum fixing temperature) is such that after fixing an unfixed solid image (25 mm × 25 mm), the image portions are bent by aligning both ends of the paper with fingers, A cylindrical object having a height of 50 mm, a diameter of 70 mm, and a total weight of 800 g is applied at a speed of 200 mm / sec. The fixing temperature at which the width of the image defect portion at that portion is 0.2 mm or less was defined as the minimum fixing temperature.
Further, (5) the hot offset temperature was set to the lowest temperature at which the soiling of the corresponding blank paper portion was visually confirmed after one round of the fixing belt surface after fixing the unfixed image. The fixing stable temperature range was a temperature range 5 ° C. inside from the minimum fixing temperature and the hot offset temperature.

<Example B2>
(Manufacture of toner)
Amorphous polyester resin particle dispersion (1) 266.6 parts Crystalline polyester resin dispersion 119.0 parts Colorant dispersion 48.0 parts Anionic surfactant (Dowfax 2A1, manufactured by Dow Chemical Co., Ltd.) 20% aqueous solution) 11.5 parts / release agent dispersion 80.2 parts In a polymerization kettle equipped with a pH meter, stirring blades, and thermometer, among the above raw materials, polyester resin particle dispersion (1), anionic interface The surfactant and 548 parts of ion-exchanged water were added, and the surfactant was blended with the amorphous polyester resin particle dispersion (1) while stirring at 200 rpm for 15 minutes. Subsequently, the colorant dispersion and the release agent dispersion were added and mixed, and then a 0.3 M nitric acid aqueous solution was added to the raw material mixture to adjust the pH to 2.7. Subsequently, 27 parts of a 10% nitric acid aqueous solution of polyaluminum chloride as a flocculant was dropped while applying a shearing force at 1000 rpm with Ultraturrax (manufactured by IKA Japan). In addition, since the viscosity of the raw material mixture increases during the dropping of the flocculant, the dropping speed was reduced when the viscosity increased, so that the flocculant was not biased to one place. When the dropping of the flocculant was completed, the rotational speed was further increased to 6000 rpm and the mixture was stirred for 5 minutes to sufficiently mix the flocculant and the raw material mixture.

  Subsequently, the raw material mixture was stirred at 550 to 650 rpm while being heated to 30 ° C. with a mantle heater. After stirring for 60 minutes, it was confirmed that the primary particle diameter was stably formed using a Coulter Multisizer II type (aperture diameter: 50 μm, manufactured by Beckman-Coulter). The temperature was raised to 45 ° C at a rate of 1 minute. The growth of the agglomerated particles is confirmed at any time using a Coulter Multisizer type II, and the agglomeration temperature and the number of rotations of stirring are changed depending on the agglomeration speed.

On the other hand, 75.4 parts of ion-exchanged water and 5.6 parts of an anionic surfactant (dowfax 2A1, 20% aqueous solution) were added to 147.4 parts of the amorphous polyester resin particle dispersion (1) for coating aggregated particles. In addition, a coating resin particle dispersion (1) prepared in advance and adjusted to pH 2.7 was prepared. When the agglomerated particles grow to 5.0 μm in the agglomeration step, the coating resin particle dispersion (1) is added and held for 10 minutes with stirring. Here, the high acid value dispersant (3) (Gifu Ceramics) GSM301 (styrene maleic acid resin weight average molecular weight: 3000, acid value: 470 mg KOH / g), 20% aqueous ammonium solution (neutralization rate 80%)), 25 parts, was added, and then the coated aggregated particles (adhered particles) In order to stop the growth of EDTA, 16.7 parts of EDTA (12% querest 40 aqueous solution) and 1M aqueous sodium hydroxide solution were sequentially added to control the pH of the raw material mixture to 6.5. Subsequently, in order to fuse the aggregated particles, the temperature was raised to 75 ° C. at a temperature raising rate of 1 ° C./min while adjusting the pH to 6.5. After confirming that the aggregated particles were fused with an optical microscope, ice water was injected and rapidly cooled at a cooling rate of 100 ° C./min.
Washing and drying were performed in accordance with Example B1 to obtain toner base particles (B2) having a volume average particle diameter of 6.0 μm.

Using the toner base particles (B2), a toner was prepared according to Example B1, and the toner physical properties were measured and the toner was evaluated according to Example B1.
The results are summarized in Tables 5 to 8.

<Example B3>
In the preparation of the toner of Example B2, except that the chelating agent EDTA was changed to 8.35 parts, the aggregated particles were prepared according to Example B2, and the aggregated particles were coated, fused, washed and dried, Toner base particles (B3) having an average particle size of 6.6 μm were obtained.

Using the toner base particles (B3), a toner was prepared according to Example B1, and the toner physical properties were measured and the toner was evaluated according to Example B1.
The results are summarized in Tables 5 to 8.

<Example B4>
In the production of the toner of Example B1, except that the pH for stopping aggregation and starting coalescence was 7.0, aggregated particles were produced in the same manner as in Example 1, and the aggregated particles were coated, fused, and washed. Drying was performed to obtain toner base particles (B4) having a volume average particle size of 6.3 μm.

Using the toner base particles (B4), a toner was prepared according to Example B1, and the toner physical properties were measured and the toner was evaluated according to Example B1.
The results are summarized in Tables 5 to 8.

<Example B5>
In the evaluation of the toner of Example B1, a developer was prepared according to Example B1 except that the resin-coated ferrite particles (volume average particle diameter 35 μm, shape factor SF1: 146) were used as a carrier. The actual machine characteristics were evaluated.
The results are summarized in Tables 5 to 8.

<Example B6>
In the evaluation of the toner of Example B1, a developer was prepared according to Example B1 except that the resin-coated ferrite particles (volume average particle diameter 35 μm, shape factor SF1: 113) were used as a carrier. The actual machine characteristics were evaluated.
The results are summarized in Tables 5 to 8.

<Comparative Example B1>
In the production of the toner of Example B1, granulation was performed according to Example B1, except that the high acid value dispersant (4) was not used. However, in the coalesced particle fusion step, particle growth cannot be controlled, resulting in coarse powder, and toner particles cannot be recovered.

<Comparative Example B2>
Aggregated particles were produced according to Example B1 and coated with the agglomerated particles, except that the high acid value dispersant (4) was not used in the production of the toner of Example B1. Thereafter, in order to stop the growth of the coated aggregated particles (adherent particles), a 1M aqueous sodium hydroxide solution was added to control the pH of the raw material mixture to 9.0. Subsequently, in order to fuse the aggregated particles, the temperature was raised to 90 ° C. at a temperature raising rate of 1 ° C./min while adjusting the pH to 8.0. After confirming that the aggregated particles were fused with an optical microscope, ice water was injected and rapidly cooled at a cooling rate of 100 ° C./min.
Subsequently, washing and drying were performed under the same conditions as in Example B1, and toner base particles (b12) having a volume average particle diameter of 6.1 μm were obtained.

Using the toner base particles (b12), a toner was prepared according to Example B1, and the physical properties of the toner and the evaluation of the toner were performed according to Example B1.
The results are summarized in Tables 5 to 8.

<Comparative Example B3>
In Example B1, instead of the high acid value dispersant (4), an aqueous solution 10 of A210 (polyacrylic acid sodium salt, acid value: 597 mgKOH / g, weight average molecular weight: 2000, manufactured by Toagosei Co., Ltd.) 10% Except for using the part, aggregated particles were prepared and coated with the aggregated particles according to Example B1. Thereafter, in order to stop the growth of the coated aggregated particles (adhered particles), 16.7 parts of EDTA (12% chillest 40 aqueous solution) and 1M aqueous sodium hydroxide solution were added in order, and the pH of the raw material mixture was adjusted to 8.0. Controlled. Subsequently, in order to fuse the aggregated particles, the temperature was raised to 75 ° C. at a temperature raising rate of 1 ° C./min while adjusting the pH to 8.0. After confirming that the aggregated particles were fused with an optical microscope, ice water was injected and rapidly cooled at a cooling rate of 100 ° C./min. Subsequently, washing and drying were performed under the same conditions as in Example B1, and toner base particles (b3) having a volume average particle size of 5.8 μm were obtained.

<Comparative Example B4>
In Example B1, instead of the high acid value dispersant (4), an A30SL (Toagosei Co., Ltd., polyacrylic acid ammonium salt, acid value: 630 mg KOH / g, weight average molecular weight: 6000) solid content concentration 40% aqueous solution Except for using 10 parts of the above, aggregated particles were prepared and coated with the aggregated particles according to Example B1. Thereafter, in order to stop the growth of the coated aggregated particles (adherent particles), a 1M sodium hydroxide aqueous solution was added in order to control the pH of the raw material mixture to 8.0. Subsequently, in order to fuse the aggregated particles, the temperature was raised to 75 ° C. at a temperature raising rate of 1 ° C./min while adjusting the pH to 8.0. After confirming that the aggregated particles were fused with an optical microscope, ice water was injected and rapidly cooled at a cooling rate of 100 ° C./min. Subsequently, washing and drying were performed under the same conditions as in Example B1, and toner base particles (b4) having a volume average particle diameter of 5.9 μm were obtained.

<Comparative Example B5>
Amorphous polyester resin (1): 1573 parts Crystalline resin: 136.8 parts Phthalocyanine pigment (manufactured by Dainichi Seika Co., Ltd., CI Pigment Blue 15: 3): 110 parts Ester wax (Nippon Yushi KEP Co., Ltd., WEP5): 180 parts The above mixture is kneaded with an extruder, pulverized with a jet mill, and then classified with a wind classifier to obtain toner base particles (b5) having a volume average particle diameter D50v of 6.6 μm. Obtained.

Subsequently, for mixing with the external additive and mixing with the carrier, a developer was prepared according to Example B1, and evaluation was performed according to Example B1.
The results are summarized in Tables 5 to 8.

From the results shown in Tables 1 to 8, the Examples exhibited good characteristics without problems with respect to cleaning properties, image quality, and other secondary obstacles, while achieving both good charge amount and low-temperature fixability.
On the other hand, for example, when the high acid value dispersant of the comparative example is not used, the particle growth of the toner cannot be controlled, or even when the toner is granulated, the pH for controlling the particle size growth is 8.0 to 9. Even if the toner particle growth can be controlled by increasing the value to 0.0, the moisture content of the toner becomes high, resulting in an adverse effect on image quality characteristics and photoconductor contamination in a real machine under high temperature and high humidity. It became.

1 is a schematic configuration diagram illustrating an example of an image forming apparatus of the present invention. It is a schematic block diagram which shows an example of the process cartridge of this invention.

Explanation of symbols

1Y, 1M, 1C, 1K, 107 photoconductor (image carrier)
2Y, 2M, 2C, 2K, 108 Charging roller 3Y, 3M, 3C, 3K Laser beam 3 Exposure device 4Y, 4M, 4C, 4K, 111 Developing device (developing means)
5Y, 5M, 5C, 5K Primary transfer rollers 6Y, 6M, 6C, 6K, 113 Photoconductor cleaning device (cleaning means)
8Y, 8M, 8C, 8K Toner cartridge 10Y, 10M, 10C, 10K Unit 20 Intermediate transfer belt 22 Drive roller 24 Support roller 26 Secondary transfer roller (transfer means)
28, 115 Fixing device (fixing means)
30 Intermediate transfer member cleaning device 112 Transfer device 116 Mounting rail 117 Opening 118 for static elimination exposure Opening 200 for exposure Process cartridge,
P, 300 Recording paper (transfer object)

Claims (7)

A polyester resin, a colorant and a release agent, and a compound satisfying the following (1), (2) and (3):
The content of the compound satisfying the following (1), (2) and (3) is 2.5 to 10% by mass,
The average circularity is in the range of 0.94 to 0.98, the sodium content is in the range of 0 to 0.20 in the net intensity by fluorescent X-ray measurement, and the aluminum content is the net by fluorescent X-ray measurement. The strength is in the range of 0.02 to 0.30, and the water content after being left in an environment of 28 ° C./85% RH for 3 days is 1.5% by mass or less,
In the emulsification step of dispersing each material of the polyester resin, the colorant and the colorant in an aqueous dispersion medium, and a compound satisfying the following (1), (2) and (3) are added to the dispersion of the polyester resin Obtained by mixing the obtained dispersion liquid, an aggregation process for producing aggregated particles from the raw material dispersion obtained by mixing the obtained dispersion liquids, and a fusion process for heating the aggregated particles to obtain toner. A toner for developing an electrostatic latent image.
(1) Acid value ranges from 200 to 500 mgKOH / g
(2) Range of weight average molecular weight of 1500-6500
(3) A polymerizable monomer containing either acrylic acid or maleic acid as the polymerizable monomer constituting the acid component, and containing either styrene or methylstyrene as the other polymerizable monomer A polymer obtained by polymerizing   2. The electrostatic latent image developing toner according to claim 1, comprising a crystalline polyester resin and having a ½ drop temperature by a flow tester of 85 ° C. or higher and 115 ° C. or lower. It includes a toner, an electrostatic latent image developer, wherein the toner is a toner for electrostatic latent image development according to claim 1 or 2. The electrostatic latent image developer according to claim 3 , comprising a carrier, wherein the carrier has a shape factor SF1 in the range of 115 to 140. Toner contained at least, toner cartridge, wherein said toner is an electrostatic latent image developing toner according to claim 1 or 2. A process cartridge comprising at least a developer holder and containing the electrostatic latent image developer according to claim 3 . A latent image holding member; developing means for developing the electrostatic latent image formed on the latent image holding member into a toner image with a developer; and a toner image formed on the latent image holding member on the transfer target member. A transfer means for transferring and a fixing means for fixing the toner image transferred onto the transfer medium, wherein the developer is the electrostatic latent image developer according to claim 3. Image forming apparatus.

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