JP5521432B2 - Electrostatic image developing toner, electrostatic image developer, toner cartridge, process cartridge, and image forming apparatus - Google Patents

Description

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

  Image formation using electrophotography is performed by charging, exposing and developing the surface of the photoreceptor to form a toner image, and then transferring and fixing the toner image to the surface of the recording medium. As a fixing method, there is a method of fixing by heating, pressing, or light.

For example, Patent Document 1 has no THF-insoluble component, and has a weight average molecular weight of 10,000 to 200,000, a number average molecular weight of 1,000 to 10,000, and a molecular weight of 1 × 10 ⁷ or more in the molecular weight distribution by GPC of the THF-soluble component. An electrostatic charge image developing toner containing 5% by weight or more and 15% by weight or less of a binder resin mainly composed of a polyester and a vinyl polymer is disclosed.

In Patent Document 2, in order to prevent offset by uniformly dispersing resins having different molecular weights, the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the resin is 3 or more and 70 or less. And an electrostatic charge image developing toner in which the BET specific surface area of the toner is 5 m ² / g or more.

  In Patent Document 3, an endothermic peak measured by DSC is 78 ° C. or more and 100 ° C. or less, an endothermic peak half-value width is 10 ° C. or more, and an exothermic peak is 75 ° C. or more and 100 for the purpose of suppressing image unevenness by preventing fouling of a fixing member. An electrophotographic toner comprising a microcrystalline wax mold release agent having an exothermic peak half-width of 10 ° C. or lower and a resin having a polar group is disclosed.

  Patent Document 4 includes an amorphous resin and a crystalline resin, the content of the crystalline resin in the binder resin is in the range of 10% by mass to 30% by mass, and the weight of the binder resin The ratio (Mw / AV) of the average molecular weight (Mw) to the acid value (AV) is in the range of 20,000 to 35,000, and the Z average molecular weight (Mz) is 500,000 to 1,600, An electrostatic latent image developing toner containing a binder resin in the range of 000 or less and a colorant is disclosed.

JP-A-5-88403 JP-A-9-265210 JP 2006-195040 A JP 2006-276305 A

  The subject of the present invention is that the electrostatic image developing toner has a ratio (I / Ip) of the following maximum endothermic absorption intensity (Ip) and the following maximum endothermic absorption intensity (I) in the differential scanning calorimetry of 0.05. It is an object to provide a toner for developing an electrostatic charge image in which a decrease in image intensity due to temperature and humidity is suppressed as compared with the case where a release agent of 0.2 or less is not contained.

The said subject is made | formed by the following this invention. That is,
The invention according to claim 1 has at least a binder resin and a release agent,
The release agent has a maximum endothermic absorption detected by differential scanning calorimetry in a range of 75 ° C. or higher and 90 ° C. or lower. The maximum endothermic absorption intensity (Ip) and the glass transition temperature (Tg) of the binder resin. ) The ratio (I / Ip) to the maximum endothermic absorption intensity (I) detected by differential scanning calorimetry in the range of + 5 ° C. to Tg + 10 ° C. is 0.05 to 0.2 , and the Tg + 5 ° C. the Tg + 10 ° C. or less of the releasing agent der Ru toner for developing electrostatic images having a maximum endothermic absorption in the range above.

  The invention according to claim 2 is the electrostatic image developing toner according to claim 1, wherein the binder resin has a weight average molecular weight of 200,000 or more and 600,000 or less.

  The invention according to claim 3 is the toner for developing an electrostatic charge image according to claim 1 or 2, wherein the binder resin has a glass transition temperature (Tg) of 50 ° C or higher and 70 ° C or lower.

  The invention according to claim 4 is an electrostatic image developer comprising the electrostatic image developing toner according to any one of claims 1 to 3.

  According to a fifth aspect of the present invention, there is provided a toner cartridge that accommodates the electrostatic charge image developing toner according to any one of the first to third aspects and is detachable from the image forming apparatus.

  According to a sixth aspect of the present invention, there is provided developing means for accommodating the electrostatic charge image developer according to the fourth aspect and developing the electrostatic charge image formed on the image carrier as a toner image by the electrostatic charge image developer. A process cartridge provided and detachable from the image forming apparatus.

The invention according to claim 7 is an image holding member;
Charging means for charging the surface of the image carrier;
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged photoreceptor;
Developing means for developing the electrostatic charge image formed on the image carrier as a toner image with the electrostatic charge image developer according to claim 4;
Transfer means for transferring the toner image formed on the image carrier onto a recording medium;
Fixing means for fixing the toner image transferred onto the recording medium;
An image forming apparatus comprising:

  According to an eighth aspect of the present invention, the fixing unit includes a fixing member and a pressure member provided in contact with the fixing member, and the fixing member has a surface thermal conductivity of 1 W / m · K or more, The image forming apparatus according to claim 7, wherein the image forming apparatus is 000 W / m · K or less.

  The invention according to claim 9 is the image forming apparatus according to claim 7 or 8, wherein the fixing member is a metal member.

  According to the first aspect of the present invention, the electrostatic image developing toner has a ratio (I / Ip) between the maximum endothermic absorption intensity (Ip) and the maximum endothermic absorption intensity (I) in differential scanning calorimetry. Compared to the case where no release agent containing 0.05 or more and 0.2 or less is contained, the image strength due to temperature and humidity is less likely to be lowered.

  According to the invention of claim 2, even when the weight average molecular weight (Mw) of the binder resin contained in the toner for developing an electrostatic charge image is 200,000 or more and 600,000 or less, the temperature and the humidity are not affected. The resulting image intensity is unlikely to decrease.

  According to the third aspect of the present invention, compared to the case where the glass transition temperature (Tg) of the binder resin is not 50 ° C. or higher and 70 ° C. or lower, the image intensity due to the temperature and humidity is less likely to decrease.

  According to the invention of claim 4, the electrostatic image developing toner is a ratio (I / Ip) between the maximum endothermic absorption intensity (Ip) and the maximum endothermic absorption intensity (I) in differential scanning calorimetry. Compared to the case where no release agent containing 0.05 or more and 0.2 or less is contained, the image strength due to temperature and humidity is less likely to be lowered.

  According to the invention of claim 5, the electrostatic charge image developing toner is a ratio (I / Ip) between the maximum endothermic absorption intensity (Ip) and the maximum endothermic absorption intensity (I) in differential scanning calorimetry. Compared to the case where no release agent containing 0.05 or more and 0.2 or less is contained, the image strength due to temperature and humidity is less likely to be lowered.

  According to the invention of claim 6, the electrostatic charge image developing toner is a ratio (I / Ip) between the maximum endothermic absorption intensity (Ip) and the maximum endothermic absorption intensity (I) in differential scanning calorimetry. Compared to the case where no release agent containing 0.05 or more and 0.2 or less is contained, the image strength due to temperature and humidity is less likely to be lowered.

  According to the seventh aspect of the invention, the electrostatic image developing toner is a ratio (I / Ip) between the maximum endothermic absorption intensity (Ip) and the maximum endothermic absorption intensity (I) in differential scanning calorimetry. Compared to the case where no release agent containing 0.05 or more and 0.2 or less is contained, the image strength due to temperature and humidity is less likely to be lowered.

  According to the invention of claim 8, even when a fixing member having a surface thermal conductivity of 1 W / m · K or more and 1,000 W / m · K or less is used, the toner for developing an electrostatic charge image has a differential. In the case where a release agent having a ratio (I / Ip) between the maximum endothermic absorption intensity (Ip) and the maximum endothermic absorption intensity (I) in the scanning calorimetry is 0.05 or more and 0.2 or less is not included. In comparison, the image intensity due to temperature and humidity is less likely to decrease.

  According to the ninth aspect of the present invention, even when the fixing member is a metal member, the electrostatic charge image developing toner has the maximum endothermic absorption intensity (Ip) and the maximum endothermic absorption in the differential scanning calorimetry. Compared with the case where a release agent having a ratio (I / Ip) to intensity (I) of 0.05 or more and 0.2 or less is not included, the image intensity due to temperature and humidity is less likely to decrease.

1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an exemplary embodiment. It is a schematic block diagram which shows an example of the process cartridge which concerns on this embodiment.

  Hereinafter, embodiments of the present invention will be described.

(Static image developing toner)
The electrostatic image developing toner according to the exemplary embodiment (hereinafter referred to as toner) includes at least a binder resin and a release agent, and the release agent has a differential in a range of 75 ° C. or higher and 90 ° C. or lower. It has a maximum endothermic absorption detected by scanning calorimetry, and has a maximum endothermic absorption intensity (Ip) and a glass transition temperature (Tg) of the binder resin + 5 ° C. to Tg + 10 ° C. Release agent having maximum endothermic absorption in the range of Tg + 5 ° C. or more and Tg + 10 ° C. or less with a ratio (I / Ip) to the detected maximum endothermic absorption intensity (I) of 0.05 or more and 0.2 or less. der Ru.

  Here, the fixing unit included in the image forming apparatus fixes the toner image transferred onto the recording medium (for example, paper) onto the recording medium by, for example, heat, but the heat generated by the fixing unit. Is used not only for melting the toner but also for heating the recording medium.

In particular, when the image forming apparatus is placed in a high-temperature and high-humidity environment (for example, 30 ° C. and 85% RH) such as outdoors, the recording medium in the image forming apparatus is kept at a normal temperature represented by an air-conditioned room. Compared to the case of being placed in a humid (for example, 25 ° C., 50% RH) environment, it easily absorbs moisture from the outside air.
Therefore, in the image forming apparatus placed in the high temperature and high humidity environment, when the toner image transferred onto the recording medium is fixed on the recording medium by heat, the heat generated by the fixing means absorbs moisture. The recording medium is further deprived of the amount of heat for evaporating the moisture of the recording medium. That is, it is considered that the image forming apparatus placed in the high temperature and high humidity environment uses less heat for melting the toner than in the normal temperature and normal humidity environment.

Accordingly, the toner is less likely to melt in the high temperature and high humidity environment than in the normal temperature and normal humidity environment, so that the toner image is less likely to adhere to the recording medium, and the image strength is likely to decrease.
In particular, when the fixing unit is a roller, the portion of the recording medium in which contact with the roller is delayed (the rear end portion of the recording medium in the traveling direction of the recording medium) uses less heat for the toner, and the image It is considered that the strength tends to decrease.

  Accordingly, the toner according to the present embodiment contains at least a binder resin and a release agent, and the release agent is detected in a range of 75 ° C. or higher and 90 ° C. or lower in the range of 75 ° C. or higher and the maximum endotherm detected by differential scanning calorimetry. The maximum endothermic absorption intensity (Ip) and the glass transition temperature (Tg) of the binder resin + the maximum endothermic absorption intensity detected by differential scanning calorimetry within the range of 5 ° C. to Tg + 10 ° C. ( By setting the ratio (I / Ip) to I) to be 0.05 or more and 0.2 or less, it is considered that the image intensity due to temperature and humidity is hardly lowered. The reason for this is not clear, but is presumed as follows.

  The release agent contained in the toner mainly has a function of preventing the toner from adhering to each member such as a fixing member and a function of softening the binder resin contained in the toner so that the toner is easily adhered to the recording medium. It is thought that it has. Therefore, the toner containing the binder resin further contains a release agent, whereby the hardness of the toner is reduced, and it is easier to adhere to the recording medium than when the toner does not contain a release agent. It is considered to be.

  Here, when the differential scanning calorimetry is performed, the release agent having a clear maximum absorption (peak) is melted at a temperature (melting point) at which the absorption bottom is small and the maximum absorption is detected, Easy to turn from solid to liquid. On the other hand, when the differential scanning calorimetry is performed, a release agent having a maximum absorption (peak) but having a broad absorption bottom and a broad absorption starts to melt at a temperature at which the maximum absorption is detected. However, the time from the solid to the liquid tends to be longer than that of the release agent having a clear maximum absorption (peak).

  Therefore, in the differential scanning calorimetry, in the release agent having a broad absorption and a broad absorption, the low melting point component in the release agent melts first at the temperature at which the maximum absorption is detected, It is considered that a solid component having a high melting point component remains. For this reason, it is considered that the amount of liquid becomes smaller than a release agent having a clear maximum absorption (peak) with a small width of the bottom of absorption.

  In the toner according to the exemplary embodiment, the release agent is controlled so as to have broad absorption with a wide absorption skirt, that is, the endothermic intensity (Ip) of differential scanning calorimetry at the melting point of the release agent. The ratio (I / Ip) of the maximum absorption intensity (I) in the differential scanning calorimetry in the range of the glass transition temperature Tg + 5 ° C. to the Tg + 10 ° C. of the binder resin is controlled to 0.05 to 0.2. Thus, the amount of liquid generated due to the melting of the release agent is controlled.

  Therefore, a toner containing a release agent having a broad absorption maximum with a broad absorption skirt and a binder resin has a clear maximum absorption (peak) due to heat applied from the fixing member of the image forming apparatus. It is considered that a smaller amount of the liquid release agent is generated than the release agent having (), and the liquid release agent plasticizes the binder resin to increase the adhesion to paper.

As described above, since the toner contains the release agent selected according to the Tg of the binder resin and the binder resin, the toner is recorded due to plasticity of the binder resin and the low melting point component of the release agent. It is considered that the toner adheres to the medium and exhibits toner releasability from the fixing member. The adhesion of the toner to the recording medium is attributed to plasticity between the binder resin and the low-melting-point component of the release agent, and thus is considered to have low environmental dependency such as moisture absorption of the recording medium.
Therefore, it is considered that the image intensity caused by temperature and humidity is less likely to be lowered by using the toner having the above-described configuration.
Note that when a release agent having a small absorption skirt width is used, although there is a certain effect on the reduction in image strength, the selection range for the material of the fixing member is small, resulting in the occurrence of offset and image strength. It may get worse.

  Hereinafter, each configuration of the toner according to the exemplary embodiment will be described.

[Binder resin]
The toner according to the exemplary embodiment contains a binder resin.
The binder resin according to the present embodiment is not particularly limited, and examples thereof include known amorphous resins. In addition, the binder resin may be used in combination with a crystalline resin together with an amorphous resin.

  Here, the amorphous resin is one having only a stepwise endothermic change, not a clear maximum endothermic absorption in differential scanning calorimetry, and is solid at room temperature (for example, 25 ° C.), and has a glass transition temperature. What is thermoplasticized at the above temperature. The crystalline resin refers to a resin having a clear maximum endothermic absorption (peak), not a stepwise change in endothermic amount in differential scanning calorimetry.

-Amorphous resin-
Examples of the amorphous resin include styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl acrylate, ethyl acrylate, butyl acrylate, propyl acrylate, lauryl acrylate, ethyl hexyl acrylate, and methacrylic acid. Esters having a vinyl group such as methyl, ethyl methacrylate, butyl methacrylate, propyl methacrylate, lauryl methacrylate, ethyl hexyl methacrylate, vinyl acetate, vinyl benzoate; methyl maleate, ethyl maleate, butyl maleate, etc. Carboxylic acids having a double bond; olefins such as ethylene, propylene, butylene and butadiene; carboxylic acids having a double bond such as acrylic acid, methacrylic acid and maleic acid; Combination Those copolymerized by news mixtures thereof.

  Furthermore, epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, etc., non-vinyl condensation resins, or a mixture of these with the above vinyl resins, or vinyl monomers in the presence of these resins Examples thereof include graft polymers obtained upon polymerization.

In order to control the degree of polymerization and the like, the amorphous resin may contain a dissociable vinyl monomer when polymerized together with the monomer constituting the amorphous resin.
The dissociative vinyl monomer is a raw material for polymer acids and polymer bases such as acrylic acid, methacrylic acid, maleic acid, cinnamic acid, fumaric acid, vinylsulfonic acid, ethyleneimine, vinylpyridine, and vinylamine. Monomer. A polymer acid is preferable from the viewpoint of easiness of the polymer forming reaction and the like, and among them, a dissociable vinyl monomer having a carboxyl group such as acrylic acid, methacrylic acid, maleic acid, cinnamic acid and fumaric acid is preferable. These dissociative vinyl monomers may be copolymerized and used when the amorphous resin is polymerized.

In the polymerization of polymerizable monomers, the amount of the polymerization initiator mainly affects the control of the molecular weight, and generally the molecular weight increases when the amount of the polymerization initiator is decreased.
In the present embodiment, in order to make Mw within the above range, the amount of the polymerization initiator is preferably 0.3% by mass or more and 1.0% by mass or less, and 0.5% by mass or more in the total amount of the polymer raw material. More preferably, the content is 1.0% by mass or less.

Moreover, by using an aliphatic crosslinking agent having 10 to 40 carbon atoms in the main chain as the crosslinking agent, the molecular weight distribution is expanded to the high molecular weight region, and the viscosity of the resin is suppressed.
Such aliphatic cross-linking agents may include (meth) acrylic acid esters of linear polyhydric alcohols, (meth) acrylic acid esters of substituted polyhydric alcohols; Good

  Specific examples include polyethylene glycol # 200 glycol diacrylate, polyethylene glycol # 400 glycol diacrylate, polyethylene glycol # 600 glycol diacrylate, polyethylene glycol # 1000 glycol diacrylate, 1,10-decanediol diacrylate, and the like.

  The content of the crosslinking agent is preferably 0.05% by mass or more and 5% by mass or less, and more preferably 0.1% by mass or more and 1.0% by mass or less in the total amount of the polymer raw material.

  The weight average molecular weight of the amorphous resin is preferably 200,000 or more and 600,000 or less, more preferably 220,000 or more and 550,000 or less, and 300,000 or more and 500,000 or less. Is more preferable.

-Crystalline resin-
The crystalline resin is not particularly limited as long as it is a resin having crystallinity, and specifically includes a crystalline polyester resin or a crystalline vinyl-based resin. A chain aliphatic crystalline polyester resin is more preferable.

  The crystalline polyester resin is synthesized from an acid (dicarboxylic acid) component and an alcohol (diol) component. In the present embodiment, a copolymer obtained by copolymerizing other components at a ratio of 50% by mass or less with respect to the crystalline polyester main chain is also referred to as a crystalline polyester resin.

  The method for producing the crystalline polyester resin is not particularly limited, and is produced by a general polyester polymerization method in which an acid component and an alcohol component are reacted. Examples thereof include direct polycondensation and transesterification. You may manufacture it properly depending on the type.

  The production of the crystalline polyester resin is carried out at a polymerization temperature of 180 ° C. or higher and 230 ° C. or lower. The reaction system is reduced in pressure as necessary, and reacted while removing water and alcohol generated during condensation. When the monomer is not dissolved or compatible with the reaction temperature, a solvent having a high boiling point may be added as a solubilizer and dissolved. In the polycondensation reaction, the dissolution auxiliary solvent is distilled off. In the case where a monomer having poor compatibility exists in the copolymerization reaction, it is preferable that the monomer having poor compatibility and the monomer and the acid or alcohol to be polycondensed are condensed in advance and then polycondensed together with the main component.

  Catalysts used in the production of crystalline polyester resins include alkali metal compounds such as sodium and lithium; alkaline earth metal compounds such as magnesium and calcium; metals such as zinc, manganese, antimony, titanium, tin, zirconium, and germanium Compound: Phosphorous acid compound, phosphoric acid compound, amine compound and the like.

  Specific examples of the crystalline polyester resin thus produced include poly-1,2-cyclopropene dimethylene isophthalate, polydecamethylene adipate, polydecamethylene azelate, polydecamethylene oxide, polydecamethylene. Sebacate, polydecamethylene succinate, polyeicosamethylene malonate, polyethylene-p- (carbophenoxy) butyrate, polyethylene-p- (carbophenoxy) undecanoate, polyethylene-p-phenylene diacetate, polyethylene sebacate, polyethylene succinate , Polyhexamethylene carbonate, polyhexamethylene-p- (carbophenoxy) undecanoate, polyhexamethylene oxalate, polyhexamethylene sebacate, polyhexamethylenes Rate, polyhexamethylene succinate, poly-4,4-isopropylidene diphenylene adipate, poly-4,4-isopropylidene diphenylene malonate, and the like.

Further, trans-poly-4,4-isopropylidene diphenylene-1-methylcyclopropane dicarboxylate, polynonamethylene azelate, polynonamethylene terephthalate, polyoctamethylene dodecanediate, polypentamethylene terephthalate, trans-poly -M-phenylene cyclopropane dicarboxylate, cis-poly-m-phenylene cyclopropane dicarboxylate, polytetramethylene carbonate, polytetramethylene-p-phenylene diacetate, polytetramethylene sebacate, polytrimethylene dodecanedioate , Polytrimethylene octadecandioate, polytrimethylene oxalate, polytrimethylene undecandioate, poly-p-xylene adipate, poly-p-xylene azease Over DOO, poly -p- xylene sebacate, poly glycol terephthalate, cis - poly-1,4 (2-butene) sebacate, polycaprolactone and the like.
A copolymer of a plurality of ester monomers used in these polymers, a copolymer with ester monomers, and other monomers copolymerized therewith may also be used.

  Among the crystalline polyester resins, a crystalline polyester resin having an alkylene group having 6 or more carbon atoms is preferable.

  The weight average molecular weight of the crystalline resin is preferably 10,000 or more and 30,000 or less, more preferably 15,000 or more and 28,000 or less, and more preferably 20,000 or more and 28,000 or less. Further preferred.

  The content of the crystalline resin is preferably 1% by mass or more and 30% by mass or less in the binder resin, preferably 5% by mass or more and 20% by mass or less, and 5% by mass or more and 15% by mass or less. More preferably.

  Here, a toner containing a binder resin having a weight average molecular weight (Mw) of 200,000 or more (hereinafter also referred to as “high molecular weight resin”) has a weight average molecular weight (Mw) of less than 200,000. It is considered that it becomes harder than a toner containing a resin (hereinafter also referred to as “low molecular weight resin”). Therefore, a toner containing a high molecular weight resin is less likely to melt even when heated and has a lower fixability of a toner image on a recording medium in image formation than a toner containing a low molecular weight resin. It is considered that the rigidity of the toner is relieved by using in combination with the release agent according to the form. Therefore, it is considered that the reduction in image strength is prevented even when the recording medium contains a high molecular weight resin in a high temperature and high humidity environment where the recording medium easily absorbs moisture and heat generated by the fixing device is easily taken away by the recording medium.

On the other hand, the upper limit of the weight average molecular weight (Mw) of the binder resin is preferably 600,000. If the weight average molecular weight of the binder resin is 600,000 or less, it is considered that the elasticity and hardness of the toner are not excessively increased, and the decrease in image strength is suppressed.
The weight average molecular weight Mw of the binder resin is preferably 200,000 or more and 600,000 or less, more preferably 220,000 or more and 550000 or less,
More preferably, it is 350,000 or more and 520000 or less.

  The Mw of the binder resin means an average value of the Mw of the amorphous resin and the crystalline resin Mw when the amorphous resin and the crystalline resin are contained as the binder resin.

  The measurement of Mw was performed under the following conditions using 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. The measurement conditions were a sample concentration of 0.5% and a flow rate of 0.6 ml / min. Sample injection volume 10 μl, measurement temperature 40 ° C., using 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 ”.

The molecular weights of the amorphous resin and the crystalline resin are also measured in the same manner as the molecular weight measurement method.
Further, when measuring the Mw of the binder resin contained in the toner using the toner, the toner is dissolved in THF so as to have the above concentration, and after removing insoluble components such as a colorant with filter paper, Similar measurements were made.

  The glass transition temperature (Tg) of the binder resin (both amorphous resin and crystalline resin) is preferably 50 ° C. or higher and 70 ° C. or lower, and more preferably 50 ° C. or higher and 60 ° C. or lower. When the Tg of the binder resin is 50 ° C. or higher, the heat resistance is good, and when it is 70 ° C. or lower, low temperature fixing can be performed.

  The glass transition temperature and melting temperature of the binder resin are measured using a differential scanning calorimeter (DSC) from room temperature (for example, 25 ° C.) to 150 ° C. at a heating rate of 10 ° C. per minute. The glass transition temperature of the binder resin is measured as the temperature at the intersection of the extension line of the base line and the rising line in the endothermic part. The melting temperature of the binder resin is measured as a melting maximum absorption temperature of differential thermal analysis measurement based on ASTM D3418-8 in DSC measurement. In the above measurement, a plurality of melting maximum absorptions may be shown. In this embodiment, the maximum absorption temperature is regarded as the melting temperature.

〔Release agent〕
The mold release agent according to this embodiment has a maximum endothermic absorption detected by differential scanning calorimetry in a range of 75 ° C. or higher and 90 ° C. or lower, and the maximum endothermic absorption intensity (Ip) and the glass transition of the binder resin. The ratio (I / Ip) to the maximum endothermic absorption intensity (I) detected by differential scanning calorimetry in the range of temperature (Tg) + 5 ° C. or more and Tg + 10 ° C. or less is 0.05 or more and 0.2 or less , It has the property that having a maximum endothermic absorption to the Tg + 5 ° C. or more above Tg + 10 ° C. or less. The release agent having the above characteristics is also referred to as “specific release agent”.

  Here, “maximum endothermic absorption” refers to endothermic absorption indicated by a peak-shaped absorption curve among endothermic absorption detected by differential scanning calorimetry, which is generally referred to as a peak. The “maximum endothermic absorption” refers to the maximum endothermic absorption in a certain temperature range, and the shape of the absorption curve is not limited.

  The temperature at which the maximum endothermic absorption is detected by differential scanning calorimetry of the release agent is the melting point of the release agent, that is, the specific release agent has a melting point in the range of 75 ° C. or higher and 90 ° C. or lower. Therefore, the maximum endothermic absorption intensity (Ip) detected by differential scanning calorimetry is the endothermic absorption intensity detected at the melting point of the specific release agent.

When the melting point of the specific release agent is 75 ° C. or higher, sufficient toner elasticity necessary for metal roll fixing is obtained, and when it is 90 ° C. or lower, releasability necessary for metal roll fixing is obtained. The melting point of the specific release agent is preferably 75 ° C. or higher and 88 ° C. or lower, and more preferably 75 ° C. or higher and 85 ° C. or lower.
Further, when the I / Ip is 0.05 or more, sufficient adhesion between the toner image and the paper can be obtained, and when it is 0.2 or less, in-machine contamination due to volatilization of the low melting point component of the release agent is prevented. obtain. The I / Ip is preferably 0.05 or more and 0.15 or less, and more preferably 0.05 or more and 0.1 or less.

  When the toner contains the specific release agent, the image strength due to temperature and humidity is less likely to be lower than when the specific release agent is not included. Further, since the toner contains the specific release agent, the toner has releasability from a fixing unit (for example, a metal roller) of the image forming apparatus.

The specific release agent is produced, for example, by using a known release agent as a raw material component, mixing two or more release agents, and purifying by repeating melting and cooling.
For example, in the case of producing using two release agents as raw material components, a Fischer-Tropsch wax that is a high melting point component and a paraffin wax that is a low melting point component are added to a solvent, and among all the raw material components, Heat above the higher melting point to melt all raw material components to obtain a melt of all raw material components (raw material component melting step). The melt is cooled to a temperature that gives the endothermic intensity I in the suggested scanning calorimetry of the target specific release agent with a cooler or less, and the melt is crystallized (crystallization step). After filtration, a release agent having a low melting point component with a controlled melting point is obtained by repeating the crystallization step while raising the raw material component melting step and the cooling temperature again. Subsequently, solid content is collect | recovered by filtration and a solvent is isolate | separated from the said solid content with a solvent collection | recovery apparatus.
Furthermore, after this, for the purpose of decolorization, deodorization, etc., the release agent may be purified by a method such as hydrogen purification, activated clay treatment, deodorization treatment or the like.

  Here, in order to detect the maximum endothermic absorption of the specific release agent in the range of 75 ° C. or more and 90 ° C. or less detected by differential scanning calorimetry, that is, the melting point of the specific release agent. In order to achieve 75 ° C. or higher and 90 ° C. or lower, the mixing ratio of the low melting point wax and the high melting point wax used as the raw material may be adjusted in the raw material component melting step in the manufacturing process of the specific release agent. . Increasing the high melting point wax ratio tends to increase the melting point of the release agent, and increasing the low melting point wax ratio tends to decrease the melting point of the release agent.

  In addition, the maximum endothermic absorption intensity (Ip) and the maximum endothermic absorption intensity (I) detected by differential scanning calorimetry in the range of the glass transition temperature (Tg) of the binder resin + 5 ° C. to the Tg + 10 ° C. In order to set the ratio (I / Ip) to 0.05 or more and 0.2 or less, it is preferable to adjust the cooling temperature in the crystallization step in the production process of the specific release agent. When the cooling temperature is lowered, I / Ip tends to increase, and when the cooling temperature is increased, I / Ip tends to decrease.

  It does not restrict | limit especially as a raw material component used for manufacture of a specific mold release agent, You may use a well-known mold release agent. For example, as waxes and waxes, plant waxes such as carnauba wax, cotton wax, wood wax, rice wax, animal waxes such as beeswax and lanolin, mineral waxes such as ozokerite and cercin, paraffin, microcrystalline, Petroleum waxes such as petrolatum. In addition to these natural waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax and polyethylene wax, fatty acid amides such as 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide, and chlorinated hydrocarbons, esters, and ketones A synthetic wax such as ether may be used.

  Furthermore, other mold release agents include homopolymers or copolymers of polyacrylates such as poly-n-stearyl methacrylate and poly-n-lauryl methacrylate (for example, n-stearyl acrylate / ethyl methacrylate copolymer, etc.) And the like, and crystalline polymers having a long alkyl group in the side chain. Among these, more preferable are petroleum waxes such as paraffin wax and microcrystalline wax, and synthetic waxes.

  Among the above, the raw material for the specific release agent is preferably synthetic hydrocarbon wax, petroleum wax, or synthetic wax, and more preferably Fischer-Tropsch wax, microcrystalline wax, or paraffin wax.

  Moreover, cyclohexane, toluene, benzene, etc. are used as a solvent used for melt | dissolving the raw material of a specific mold release agent, or wash | cleaning the solid content of a wax.

  The content of the specific release agent is preferably 10% by mass or more and 40% by mass or less, more preferably 10% by mass or more and 30% by mass or less, and more preferably 15% by mass or more and 30% by mass or less. More preferably, it is 15 mass% or more and 25 mass% or less. If the content rate of a specific mold release agent is 10 mass% or more, sufficient mold release property will be ensured and generation | occurrence | production of a hot offset will be prevented. On the other hand, when the amount is 40% by mass or less, the exposure of the release agent to the toner surface is small, and the fluidity and chargeability of the toner are hardly hindered.

[Other ingredients]
As described above, the components constituting the toner of the present embodiment include at least a binder resin having a specific molecular weight and a release agent whose specific absorption is detected by differential scanning calorimetry. Although it will not specifically limit, other components, such as a coloring agent, may be included as needed.

As the colorant according to this embodiment, a known organic or inorganic pigment or dye, or an oil-soluble dye is used.
For example, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 185, C.I. I. Pigment blue 15: 1, C.I. I. Pigment Blue 15: 3, Lamp Black (C.I.No. 77266), Rose Bengal (C.I.No. 45432), Carbon Black, Nigrosine Dye (C.I.No. 50415B), Metal Complex Dye, Metal Derivatives of complex salt dyes and mixtures thereof.

Furthermore, various metal oxides such as silica, aluminum oxide, magnetite and various ferrites, cupric oxide, nickel oxide, zinc oxide, zirconium oxide, titanium oxide, and magnesium oxide, and mixtures thereof can be used. The colorant to be used is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP permeability, and dispersibility in the toner.
The content of the colorant depends on the toner particle size and the development amount, but is suitably 1 part by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the binder resin. In particular, it is preferably 2 parts by mass or more and 25 parts by mass or less.

These colorants may be used alone or in combination and further used in the form of a solid solution. These colorants are dispersed by a known method, and for example, a rotary shear type homogenizer, a media type dispersing machine such as a ball mill, a sand mill, or an attritor, a high-pressure opposed collision type dispersing machine, or the like is preferably used.
Further, when these colorants are used in the emulsion aggregation method described later, a polar surfactant is used and dispersed in an aqueous system by the homogenizer.

In addition, a lubricant or a charge control agent may be added to the toner of this embodiment.
Examples of the lubricant include fatty acid amides such as ethylene bisstearylamide and oleic acid amide, and fatty acid metal salts such as zinc stearate and calcium stearate.

  The charge control agent is added to improve and stabilize the chargeability. For example, a dye containing a complex such as a quaternary ammonium salt compound, a nigrosine compound, aluminum, iron, or chromium, or a triphenylmethane type Various commonly used charge control agents such as pigments are used, but the ionic strength affects the stability of the aggregated particles in the aggregation process and fusion / unification process when the toner is prepared by the emulsion aggregation method described later. From the viewpoint of control of wastewater and reduction of wastewater contamination, materials that are difficult to dissolve in water are suitable.

  In particular, as the charge control agent, metal salts of benzoic acid, metal salts of salicylic acid, metal salts of alkyl salicylic acid, metal salts of catechol, metal-containing bisazo dyes, tetraphenylborate derivatives, and the like used in powder toners. A compound selected from the group consisting of a quaternary ammonium salt and an alkylpyridinium salt, and a combination of these compounds are preferred.

  Further, when the inorganic particles are added to the toner as a charge control agent in a wet manner, examples of the inorganic particles include silica, alumina, titania, calcium carbonate, magnesium carbonate, tricalcium phosphate, and other external additives on the normal toner surface. All inorganic particles used as In this case, these inorganic particles are used by being dispersed in a solvent using an ionic surfactant, a polymer acid, a polymer base, or the like.

Furthermore, inorganic particles or organic particles may be added to the surface of the toner of this embodiment by applying a shearing force in a dry state for the purpose of use as a fluidity aid or a cleaning aid.
Examples of the inorganic particles include all particles usually used as external additives on the toner surface, such as silica, alumina, titania, calcium carbonate, magnesium carbonate, tricalcium phosphate, and cerium oxide. Examples of the organic particles include all particles used as an external additive on the toner surface, such as vinyl resin, polyester resin, and silicone resin.

  When each of the above materials is used as an external additive, the total amount of the external additive is preferably 2% by mass or more, more preferably 3% by mass or more based on the whole toner. The upper limit of the total amount of external additives is preferably 10% by mass or less, more preferably 8% by mass or less based on the total toner.

  The volume average particle diameter of the toner according to the exemplary embodiment is preferably 4 μm or more and 10 μm or less, more preferably 5 μm or more and 8 μm or less, and further preferably 5.5 μm or more and 7.5 μm or less.

  Further, as the particle size distribution index of the toner, it is preferable that the volume average particle size distribution index GSDv is 1.30 or less and the number average particle size distribution index GSDp is 1.40 or less. Further, the ratio GSDv / GSDp between the volume average particle size distribution index GSDv and the number average particle size distribution index GSDp is preferably 0.95 or more.

The volume average particle size and the particle size distribution index are the particle size range (channel) obtained by dividing the particle size distribution measured using Coulter Multisizer II (manufactured by Coulter Co.). By subtracting the cumulative distribution, the particle size to be accumulated 16% is the volume D16v and the number D16p, the particle size to be accumulated 50% is the volume D50v (this is referred to as “volume average particle size”), the number D50p and the accumulated 84%. The particle diameter is defined as volume D84v and number D84p. The volume particle size distribution index GSDv is calculated as (D84v / D16v) ^1/2 , and the number average particle size distribution index GSDp is calculated as (D84p / D16p) ^1/2 .
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 addition, the shape factor SF1 of the toner of the present embodiment is preferably 120 ≦ SF1 ≦ 135. This 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 maximum length of each particle, and A represents the projected area of each particle.

  The average value of the shape factor SF1 is obtained by taking 50 or more toner images magnified 250 times from an optical microscope into an image analyzer (LUZEX III, manufactured by Nireco), and calculating the individual values from the maximum length and projected area. The value of SF1 for the particles is obtained and averaged.

Hereinafter, a method for producing the toner of this embodiment will be described. The method for producing the toner of the present embodiment is not particularly limited.
For example, the toner according to the exemplary embodiment includes a binder resin particle dispersion liquid in which binder resin particles are dispersed, a release agent dispersion liquid in which release agent particles are dispersed, and a colorant as needed. It is produced by mixing and aggregating the colorant dispersion obtained.

  A toner having a core / shell structure may be used. That is, a crystalline resin particle dispersion obtained by dispersing crystalline resin particles, a first amorphous resin particle dispersion obtained by dispersing first amorphous resin particles, and a color obtained by dispersing a colorant A first agglomeration step in which the agent dispersion is mixed to form core agglomerated particles, and second amorphous resin particles in which the second amorphous resin particles are dispersed in the dispersion obtained by dispersing the agglomerated particles. A second agglomeration step of mixing the resin particle dispersion to form core / shell aggregated particles in which the second amorphous resin particles are adhered to the aggregated particles; and heating the core / shell aggregated particles. It may be produced through a process including at least a fusion / union process of fusing / unifying and fusing / unifying.

  In the first and second aggregating steps, it is preferable to generate agglomeration between particles by changing pH to prepare agglomerated particles. At the same time, an aggregating agent may be added in order to stably and rapidly aggregate the particles, or to obtain aggregated particles having a narrower particle size distribution.

  In consideration of the stability of the aggregated particles, the stability of the coagulant with respect to heat and time, and the removal during washing, a metal salt of an inorganic acid is preferable as the coagulant in terms of performance and use. Specific examples include metal salts of inorganic acids such as magnesium chloride, sodium chloride, aluminum sulfate, calcium sulfate, ammonium sulfate, aluminum nitrate, silver nitrate, copper sulfate, and sodium carbonate.

  The amount of these flocculants to be added varies depending on the valence of the charge, but they are all small, and in the case of monovalent, 3% by mass or less of the entire aggregate system, in the case of divalent, 1% by mass or less, trivalent In this case, it is 0.5% by mass or less. Since the amount of the flocculant is preferably small, it is preferable to use a compound having a large valence.

Further, for example, a surfactant may be used for the purpose of stabilizing the dispersion of the resin particle dispersion, the colorant dispersion, and the release agent dispersion.
Examples of the surfactant include anionic surfactants such as sulfate ester, sulfonate, phosphate, and soap; cationic surfactants such as amine salt type and quaternary ammonium salt type; polyethylene glycol type And nonionic surfactants such as alkylphenol ethylene oxide adducts and polyhydric alcohols. Among these, an ionic surfactant is preferable, and an anionic surfactant and a cationic surfactant are more preferable.

  In general, an anionic surfactant has a strong dispersibility and is excellent in dispersing resin particles and colorants. Further, it is advantageous to use an anionic surfactant as a surfactant for dispersing the release agent.

  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 be used in combination of 2 or more type.

  The content of the surfactant in each dispersion may be a level that does not hinder the present embodiment, and is generally a small amount. Specifically, the content is 0.01% by mass or more and 10% by mass of the entire aggregate system. % Or less, more preferably 0.05% by mass or more and 5% by mass or less, and further preferably 0.1% by mass or more and 2% by mass or less.

In addition, a polyvalent carboxylic acid may be used for the purpose of preventing fusion between toners while controlling the shape of the toner in the fusion and coalescence process. The polyvalent carboxylic acids listed below are presumed to function as a protective film that adjusts the solution pH to a value necessary for toner shape control and adheres to the toner surface to prevent fusion between the toners.
Specific examples of polyvalent carboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid Acid, citric acid, malic acid, trimellitic acid and the like can be mentioned.

After completion of the coalescence / union process, toner particles are obtained by drying the toner formed in the solution through a known washing process, solid-liquid separation process, and drying process.
In addition, it is preferable that a washing | cleaning process performs substitution washing | cleaning by ion-exchange water from a charging point. The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration, and the like are preferably used from the viewpoint of productivity. Further, although the drying process is not particularly limited, freeze drying, flash jet drying, fluidized drying, vibration fluidized drying and the like are preferably used from the viewpoint of productivity.

  When external additives such as inorganic particles are externally added to the toner, they may be dispersed in a solvent using an ionic surfactant, a polymer acid, a polymer base, etc., and added to the solution. Alternatively, both the toner and the external additive may be mixed and mixed by a mixer such as a Henschel mixer.

<Electrostatic latent image developer>
The electrostatic latent image developer according to the exemplary embodiment is not particularly limited except that it contains the electrostatic latent image developing toner according to the exemplary embodiment, and may take a component composition according to the purpose. The electrostatic latent image developer according to the present embodiment becomes a one-component electrostatic latent image developer when the electrostatic latent image developing toner according to the present embodiment is used alone, and is used in combination with a carrier. And a two-component electrostatic latent image developer.

  For example, when a carrier is used, the carrier is not particularly limited, and examples thereof include known carriers. For example, the resins described in JP-A Nos. 62-39879 and 56-11461 are disclosed. Known carriers such as a coated carrier can be used.

  Specific examples of the carrier include the following resin-coated carriers. Examples of the core particle of the carrier include normal iron powder, ferrite, and magnetite molding, and the volume average particle size is 30 μm or more and 200 μm or less.

  Examples of the coating resin for the resin-coated carrier include styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, lauryl acrylate, acrylic acid 2 -Α-methylene fatty acid monocarboxylic acids such as ethylhexyl, methyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate; nitrogen-containing acrylics such as dimethylaminoethyl methacrylate; acrylonitrile, methacrylonitrile, etc. Vinyl nitriles; vinyl pyridines such as 2-vinyl pyridine and 4-vinyl pyridine; vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl Homopolymers such as vinyl ketones such as ketones; olefins such as ethylene and propylene; vinyl-based fluorine-containing monomers such as vinylidene fluoride, tetrafluoroethylene and hexafluoroethylene; and copolymers containing two or more types of monomers Furthermore, silicone resins containing methyl silicone, methyl phenyl silicone, etc., polyesters containing bisphenol, glycol, etc., epoxy resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, polycarbonate resins and the like can be mentioned. These resins may be used alone or in combination of two or more. The coating amount of the coating resin is preferably 0.1 parts by mass or more and 10 parts by mass or less, and 0.5 parts by mass or more and 3.0 parts by mass or less with respect to 100 parts by mass of the core particles. More preferred.

  For the production of the carrier, a heating kneader, a heating Henschel mixer, a UM mixer, or the like can be used. Depending on the amount of the coating resin, a heating fluidized bed, a heating kiln, or the like may be used. .

  The mixing ratio of the electrostatic latent image developing toner of the present embodiment and the carrier in the two-component electrostatic latent image developer is not particularly limited and may be selected according to the purpose.

(Image forming device)
The image forming apparatus according to the exemplary embodiment includes an image carrier, a charging unit that charges the surface of the image carrier, an electrostatic image forming unit that forms an electrostatic image on the surface of the charged photoreceptor, and the image. Developing means for developing the electrostatic image formed on the holding body as a toner image with the electrostatic image developer having the above-described configuration according to the present embodiment, and recording the toner image formed on the image holding body. A transfer unit that transfers the image onto the recording medium; and a fixing unit that fixes the toner image transferred onto the recording medium.
Further, a toner removing unit that removes toner remaining on the surface of the image holding member with a cleaning blade may be provided.

  The image formation in the image forming apparatus of the present embodiment is performed as follows, for example, when an electrophotographic photosensitive member is used as the image carrier. First, the surface of the electrophotographic photosensitive member is charged by a corotron charger, a contact charger or the like as a charging unit, and then exposed by an exposure device to form an electrostatic charge image. Next, the toner is attached to the electrostatic latent image in contact with or in proximity to a developing roll having a developer layer formed on the surface, thereby forming a toner image on the electrophotographic photosensitive member. The formed toner image is transferred onto the surface of a recording medium such as paper using a corotron charger as a charging means. Further, the toner image transferred to the surface of the recording medium is fixed by a fixing device as fixing means, and an image is formed on the recording medium. Then, the toner remaining on the surface of the photosensitive member and other adhered matters are removed using a cleaning blade as a toner removing unit, if necessary.

  As the electrophotographic photoreceptor, generally, an inorganic photoreceptor such as amorphous silicon or selenium, or an organic photoreceptor using polysilane, phthalocyanine or the like as a charge generation material or a charge transport material is used. In particular, as an electrophotographic photosensitive member, an amorphous silicon photosensitive member is used for an inorganic photosensitive member, and a so-called overcoat having a cross-linked resin layer such as a melamine resin, a phenol resin, or a silicone resin is used for an organic photosensitive member. A photoreceptor having a coating layer is desirable.

The fixing device may be any fixing device that performs fixing by heating, pressing, or light, and a fixing device including a fixing member and a pressing member provided in contact with the fixing member is used.
When the toner of this embodiment is used as a toner for light fixing, a light fixing device (flash fixing device) is used. In other cases, a heat roll fixing device, an oven fixing device, or the like is preferably used.

  As the heat roll fixing device, a heating roll type fixing device is generally used in which a pair of fixing rolls are pressed against each other. As a pair of fixing rolls, a heating roll and a pressure roll are provided to face each other, and a pressure contact portion is formed by pressure contact. The heating roll has a metal hollow core with a heater lamp inside, and a surface layer made of an oil- and heat-resistant elastic body layer (elastic layer) and a fluororesin, etc. are sequentially formed. Accordingly, an oil- and heat-resistant elastic body layer and a surface layer are sequentially formed on a metal hollow core metal core having a heater lamp inside. An unfixed toner image is fixed by passing a recording medium on which an unfixed toner image is formed through a pressure contact area formed by the heating roll and the pressure roll.

  The fixing roll may be a hot roll having a roll surface thermal conductivity of 1 W / m · K or more and 1,000 W / m · K or less. The fixing roll having a roll surface thermal conductivity of 1 W / m · K or more and 1,000 W / m · K or less includes a metal roll, which is a conventional fixing roll (resin-coated roll). It is good also as a roll structure in which the SUS material and Al material which are core metal materials are exposed as it is.

  When the fixing roll is a metal roll, the toner is required to have elasticity or hardness that prevents the toner from adhering to the roll due to the load of the metal roll. Generally, a high molecular weight resin having a weight average molecular weight (Mw) of 200,000 or more is used. The toner to be contained is used. At this time, by using the toner of the present embodiment containing the specific release agent as the toner, the high molecular weight resin is easily softened by the specific release agent, and the heat of fixing is easily taken away by the recording medium. It is considered that the image strength is unlikely to decrease even in a wet environment. Accordingly, when the fixing roll is a metal roll, it is considered that image formation due to the temperature and humidity is less likely to be reduced by forming an image using the toner according to this embodiment.

  The material of the metal roll is not particularly limited as long as it has excellent mechanical strength and good thermal conductivity. For example, a metal or alloy such as aluminum, SUS, iron, copper, or brass can be used. Can be mentioned.

  Further, this metal roll has a surface material that is higher in durability and thermal conductivity than materials other than metal (for example, resin), such as Fe, Cr, Cu, Ni, Co, Mn, and Al. These oxides may be coated alone or with a mixed material.

  The material of the cleaning blade is not particularly limited, and various elastic bodies may be used. Specific elastic bodies include elastic bodies such as polyurethane elastic bodies, silicone rubber, and chloroprene rubber.

  Hereinafter, although an example of the image forming apparatus of this embodiment is shown, it is not necessarily limited to this. In addition, the main part shown to a figure is demonstrated and the description is abbreviate | omitted about others.

FIG. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present embodiment.
The image forming apparatus shown in FIG. 1 is a quadruple tandem 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 specific distance in the horizontal direction. The units 10Y, 10M, 10C, and 10K may be process cartridges that are detachable from 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 urged away from the drive roller 22 by a spring or the like (not shown), and a specific tension is applied to the intermediate transfer belt 20 wound around the support roller 24. 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, the developing devices (developing means) 4Y, 4M, 4C, and 4K of the units 10Y, 10M, 10C, and 10K are respectively provided with yellow, magenta, cyan, and black contained in the toner cartridges 8Y, 8M, 8C, and 8K. The four colors of toner are 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, a charging roller 2Y for charging the surface of the photoreceptor 1Y to a specific potential, and the charged surface is exposed by a laser beam 3Y based on the color-separated image signal to form an electrostatic image. 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 with a cleaning blade.
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 −600V or more and −800V or less by the charging roller 2Y.
The photoreceptor 1Y is formed by laminating a photosensitive layer on a conductive substrate. 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 specific 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.

  For example, yellow toner is accommodated in the developing device 4Y. 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 photoconductor 1Y on which the yellow toner image is formed continues to run at a specific speed, and the toner image developed on the photoconductor 1Y is conveyed to a specific primary transfer position.

When the yellow toner image on the photoreceptor 1Y is conveyed to the primary transfer, a specific 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 has a (+) polarity opposite to the polarity (−) of the toner, and is controlled to +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 through the first to fourth units is arranged 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 medium P is fed at a specific 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 specific secondary transfer bias is applied to the support roller 24. The 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 medium P is applied to the toner image, so The toner image is transferred onto the recording medium 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 medium P is sent to a fixing device (fixing means) 28, the toner image is heated, and the color-superposed toner image is melted and fixed on the recording medium P. The recording medium P on which the color image has been fixed is unloaded to 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 to the recording medium P via the intermediate transfer belt 20, but 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]
FIG. 2 is a schematic configuration diagram illustrating an example of a process cartridge according to the present embodiment. The process cartridge shown in FIG. 2 includes a photosensitive member 107, a charging device 108, a developing device 111, and a unit provided with a photosensitive member cleaning device (cleaning means) 113 including a cleaning blade, an opening 118 for exposure, It is combined with and integrated with a housing 119 provided with an opening 117 for static elimination exposure and a mounting rail 116.
The process cartridge is detachable from the image forming apparatus including the transfer device 112, the fixing device 115, and other components not shown, and constitutes the image forming device. is there. P is a recording medium.

  The process cartridge shown in FIG. 2 includes a photoreceptor 107, a charging device 108, a developing device 111, and a cleaning device (cleaning means) 113. These devices are selectively combined. Specifically, for example, the process cartridge of this embodiment includes at least one selected from the charging device 108 and the transfer device 112 in addition to the photosensitive member 107, the developing device 111, and the cleaning device 113.

[Toner cartridge]
Next, the toner cartridge of this embodiment will be described. The toner cartridge of the present embodiment is detached from the image forming apparatus and stores at least toner. The toner according to the above embodiment is applied as the toner.

  The image forming apparatus shown in FIG. 1 is an image forming apparatus having a configuration in which toner cartridges 8Y, 8M, 8C, and 8K are attached and detached, and the developing devices 4Y, 4M, 4C, and 4K are each developing devices (colors). ) And a developer cartridge corresponding to the above (not shown). When the amount of toner stored in the toner cartridge is low, the developer cartridge is replaced.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these Examples at all. In the following description, “part” and “%” are all based on mass unless otherwise specified.

<Measuring method of various characteristics>
First, methods for measuring physical properties of toners and the like used in Examples and Comparative Examples will be described.

(Measurement method of molecular weight and molecular weight distribution of resin)
The molecular weight and molecular weight distribution of the binder resin are as follows. 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, an experiment was performed using a sample concentration of 0.5%, a flow rate of 0.6 ml / min, 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 ”.

(Measuring method of melting point of release agent, glass transition temperature Tg of binder resin)
The glass transition temperature (Tg) of the binder resin and the melting point of the release agent were measured at room temperature (25 ° C.) using a differential scanning calorimeter (manufactured by Mac Science: DSC3110, thermal analysis system 001) according to ASTM D3418-8. ) To 150 ° C. by measuring under a temperature rising rate of 10 ° C./min. The glass transition temperature Tg of the binder resin was the temperature at the intersection of the extension line of the base line and the rising line in the endothermic part, and the melting point of the release agent was the temperature at the top of the maximum endothermic absorption (peak).

(Volume average particle diameter and particle size distribution measurement method of toner)
For measurement of the volume average particle size and particle size distribution of the toner, Coulter Multisizer II type (manufactured by Coulter) was used as a measuring device, and ISOTON-II (manufactured by Coulter) was used as an electrolytic solution.

Specifically, for the particle size range (channel) divided by the particle size distribution measured using Coulter Multisizer II (manufactured by Coulter Company), the cumulative distribution is subtracted from the small particle size side for each volume and number, The particle size to be accumulated 16% is volume D16v and a number D16p, the particle size to be accumulated 50% is volume D50v (this is referred to as “volume average particle size”), the number D50p and the particle size to be accumulated 84% is volume D84v. The volume particle size distribution index GSDv was calculated as (D84v / D16v) ^1/2 . The number average particle size distribution index GSDp was calculated as (D84p / D16p) ^1/2 .
The measurement was performed after the toner was dispersed in an aqueous electrolyte solution (ISOTON-II) and dispersed by ultrasonic waves for 30 seconds or more.

(Toner shape factor SF1 measurement method)
The toner shape factor SF1 is obtained by taking an optical microscope image of toner dispersed on a slide glass into a Luzex image analyzer through a video camera, calculating SF1 for 50 toners, and obtaining an average value. This 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 maximum length of each particle, and A represents the projected area of each particle.

(Volume average particle diameter of resin particles and colorant particles)
The volume average particle diameter of the resin particles and the colorant particles was measured using Coulter Multisizer II (manufactured by Coulter, Inc.) in the same manner as the toner.

<Production of toner>
A method for preparing the release agent, binder resin, and colorant will be described.

(Preparation of mold release agent)
-Preparation of release agent 1-
・ Raw ingredient 1
Fischer-Tropsch wax FT0070 (Nippon Seiwa Co., Ltd., melting point 73 ° C.) 90 parts, raw material component 2
3 parts of paraffin wax HNP3 (manufactured by Nippon Seiwa Co., Ltd., melting point 64 ° C.)

  The above raw material was added to 200 parts of toluene, heated to 90 ° C. to melt, and left at that temperature for 30 minutes. Thereafter, the temperature was lowered by 1 ° C. per minute to 50 ° C. and left at 50 ° C. for 20 minutes. The obtained solid content was filtered, melted again in 200 parts of toluene heated to 90 ° C., the temperature was lowered by 1 ° C. per minute to 60 ° C., and left at 60 ° C. for 30 minutes. The obtained solid content was filtered, washed with 20 parts of toluene, and then dried with a vacuum dryer to obtain a release agent 1 having a melting point of 75 ° C.

-Preparation of release agent 2-
・ Raw ingredient 1
50 parts of microcrystalline wax HiMic 1090 (manufactured by Nippon Seiwa Co., Ltd., melting point 82 ° C.)
Fischer Tropsch wax FT0070 (Nippon Seiwa Co., Ltd., melting point 73 ° C.) 35 parts

  In the preparation of the release agent 1, a release agent 2 was obtained in the same manner except that the raw material was changed to the above raw material. Molding agent 2 had a melting point of 82 ° C.

-Preparation of release agent 3-
・ Raw ingredient 1
Fischer-Tropsch wax FNP0090 (manufactured by Nippon Seiwa Co., Ltd., melting point 90 ° C.) 80 parts, raw material component 2
Paraffin wax HNP3 (Nippon Seiwa Co., Ltd., melting point 64 ° C.) 5 parts

  In the preparation of the release agent 1, a release agent 3 was obtained in the same manner except that the raw material was changed to the above raw material and the temperature of heated toluene was changed to 100 ° C. The melting point of the release agent 3 was 90 ° C.

-Preparation of release agent 4-
・ Raw ingredient 1
70 parts of microcrystalline wax HiMic 1090 (manufactured by Nippon Seiwa Co., Ltd., melting point 82 ° C.)
Fischer Tropsch wax FT0070 (Nippon Seiwa Co., Ltd., melting point 73 ° C.) 35 parts

  In the preparation of the mold release agent 1, the mold release agent 4 was obtained in the same manner except that the raw material was changed to the above raw material, and the second cooling temperature was changed to 65 ° C. The melting point of the release agent 4 was 82 ° C.

-Preparation of release agent 5-
・ Raw ingredient 1
40 parts of microcrystalline wax HiMic 1090 (manufactured by Nippon Seiwa Co., Ltd., melting point 82 ° C.)
Fischer Tropsch wax FT0070 (Nippon Seiwa Co., Ltd., melting point 73 ° C.) 35 parts

  In the preparation of the mold release agent 1, the mold release agent 5 was obtained in the same manner except that the raw materials were changed to the above raw materials and the second cooling temperature was 55 ° C. The melting point of the release agent 5 was 82 ° C.

-Preparation of release agent 6-
・ Raw ingredient 1
98 parts of the release agent 2 and raw material component 2
2 parts of paraffin wax HNP3 (manufactured by Nippon Seiwa Co., Ltd., melting point 64 ° C.)

  In the preparation of the release agent 1, a release agent 6 was obtained in the same manner except that the raw material was the above-mentioned raw material and the second cooling temperature was changed to 62 ° C. The melting point of the release agent 6 was 82 ° C.

-Preparation of release agent 7-
In the preparation of the mold release agent 1, only Fischer-Tropsch wax FT0070 (manufactured by Nippon Seiwa Co., Ltd., melting point: 73 ° C.) was used as a raw material component, and the temperature of the heated toluene was changed to 75 ° C. in the same manner. A mold 7 was obtained. The melting point of the release agent 7 was 69 ° C.

-Preparation of release agent 8-
・ Raw ingredient 1
Fischer-Tropsch wax FT105 (manufactured by Nippon Seiwa Co., Ltd., melting point 96 ° C.) 90 parts, ingredient 2
Paraffin wax HNP3 (Nippon Seiwa Co., Ltd., melting point 64 ° C.) 5 parts

  In the preparation of the release agent 1, a release agent 8 was obtained in the same manner except that the raw material was changed to the above raw material and the temperature of heated toluene was changed to 110 ° C. The melting point of the release agent 8 was 95 ° C.

-Preparation of release agent 9-
As the mold release agent 9, ester wax WEP5 (manufactured by NOF Corporation, melting point 85 ° C.) was used as it was.

-Preparation of mold release agent 10-
・ Raw ingredient 1
93 parts of the release agent 2 and raw material component 2
7 parts of paraffin wax HNP3 (manufactured by Nippon Seiwa Co., Ltd., melting point 64 ° C.)

  In the preparation of the release agent 1, a release agent 10 was obtained in the same manner except that the raw material was changed to the above raw material and the second cooling temperature was changed to 55 ° C. The melting point of the release agent 10 was 82 ° C.

-Preparation of release agent 11-
・ Raw ingredient 1
Microcrystalline wax HiMic 1090 (manufactured by Nippon Seiwa Co., Ltd., melting point 82 ° C.) 90 parts, raw material component 2
3 parts of paraffin wax HNP3 (manufactured by Nippon Seiwa Co., Ltd., melting point 64 ° C.)

  In the preparation of the mold release agent 1, the mold release agent 11 was obtained in the same manner except that the raw material was the above-mentioned raw material and the second cooling temperature was changed to 55 ° C. The melting point of the release agent 11 was 82 ° C.

-Preparation of release agent 12-
・ Raw ingredient 1
Ester wax WEP5 (Nippon Yushi Co., Ltd., melting point 85 ° C.) 90 parts, ingredient 2
3 parts of paraffin wax HNP9 (manufactured by Nippon Seiwa Co., Ltd., melting point 75 ° C.)

  In the preparation of the mold release agent 1, the raw material was the same as the raw material, the second cooling temperature was 60 ° C., the third raw material component melting step, and then the crystallization step was performed at a cooling temperature of 70 ° C. Thus, a release agent 12 was obtained. The melting point of the release agent 12 was 84 ° C.

  In preparing the toner to be described later, 20 parts of each of Release Agent 1 to Release Agent 10 obtained as described above were added to an anionic surfactant (Dow Fax, manufactured by Dow Chemical Company) 1.5. Part was added to a solution dissolved in 425 parts of ion-exchanged water, and used as a dispersion obtained by dispersing and emulsifying.

  Table 1 shows the raw material components and melting points of the obtained release agents 1 to 12. In Table 1, the unit of “melting point” is [° C.], and the unit of “amount” is [parts].

(Preparation of binder resin dispersion)
-Preparation of resin 1-
340 parts of styrene (manufactured by Wako Pure Chemical Industries, Ltd.), 95 parts of n-butyl acrylate (manufactured by Wako Pure Chemical Industries, Ltd., BA), 5 parts of acrylic acid (manufactured by Rhodia Nikka Co., Ltd.) and dodecanethiol (manufactured by Wako Pure Chemical Industries, Ltd., DDT) To 2.3 parts mixed and dissolved, a solution prepared by dissolving 1.5 parts of an anionic surfactant (Dowfax, manufactured by Dow Chemical Co., Ltd.) in 550 parts of ion-exchanged water was added and dispersed and emulsified in a flask. . The solution in which 4.5 parts of ammonium persulfate (polymerization initiator, APS) was further dissolved in 50 parts of ion-exchanged water was added while slowly stirring and mixing as it was for 10 minutes. Next, after sufficiently replacing the nitrogen in the flask, the solution in the flask was heated with an oil bath to 65 ° C. while stirring, and emulsion polymerization was continued for 5 hours, so that anionic amorphous resin particles were obtained. A dispersion (resin 1) was obtained. The amount of solid content (resin 1) in the amorphous resin particle dispersion was 41.9%, and the volume average particle size was 169 nm. Moreover, the weight average molecular weight Mw of the resin 1 was 436,000, and the glass transition temperature was 56.7 degreeC.

-Resin 2 to Resin 11-
Resin 2 to Resin 11 were prepared in the same manner as in the dispersion of Resin 1 except that the amounts of n-butyl acrylate (BA), ammonium persulfate (APS) and dodecanethiol (DDT) were as shown in Table 2. A dispersion was prepared.
The composition of each resin and the polymerization average molecular weight Mw are shown together in Table 2. In Table 2, the unit of “amount” is [part].

(Preparation of colorant dispersion)
・ Carbon black (Cabot Corporation, Regal 330) 30 parts ・ Anionic surfactant (Nippon Yushi Co., Ltd., Newlex R) 2 parts ・ Ion-exchanged water 220 parts

  The above components are mixed and pre-dispersed for 10 minutes with a homogenizer (Ultra Turrax, manufactured by IKA), followed by a dispersion treatment at a pressure of 245 mPa for 15 minutes using a counter impact type wet pulverizer (Altimizer, manufactured by Sugino Machine). And a colorant dispersion having a volume average particle size of 328 nm was obtained.

(Production of toner)
-Toner 1
-Resin 1 dispersion 200 parts-Colorant dispersion 80 parts-Release agent 1 dispersion 50 parts

  The above components were put into a round stainless steel flask, and a solution mixed and dispersed with an Ultra Turrax T50 was obtained. Next, 0.2 parts of polyaluminum chloride was added to this solution to produce core agglomerated particles, and the dispersion operation was continued using an ultra turrax. Further, the solution in the flask was heated to 47 ° C. with stirring in an oil bath for heating and held at 47 ° C. for 60 minutes, and then 100 parts of the resin 1 dispersion was added thereto to produce core / shell aggregated particles. did.

  Thereafter, a 0.5 mol / L sodium hydroxide aqueous solution was added to adjust the pH of the solution to 6.5. Thereafter, the stainless steel flask was sealed and heated to 98 ° C. while continuing stirring using a magnetic seal, and 0.3 mol / L nitric acid aqueous solution was added to adjust the pH of the solution to 4.2. Subsequently, 0.3 mol / L citric acid aqueous solution was added to adjust the pH of the solution to 3.1, and the solution was held for 5 hours.

  After cooling, the particles dispersed in the solution were filtered, washed with ion-exchanged water, and subjected to solid-liquid separation by Nutsche suction filtration. This was further redispersed in 3 L of ion exchanged water at 40 ° C., and stirred and washed at 300 rpm for 15 minutes. This operation was further repeated 5 times, and when the pH of the filtrate was 7.01 and the electric conductivity was 15.8 μS / cm, No. was obtained by Nutsche suction filtration. Solid-liquid separation was performed using 5A filter paper, and the obtained solid was vacuum-dried over 12 hours to obtain black toner 1.

  When the particle size distribution of the toner 1 was measured, the volume average particle size D50v was 6.4 μm, the number average particle size distribution index GSDp was 1.25, and the volume average particle size distribution index GSDv was 1.28. Further, the shape factor SF1 of the toner 1 was 131.

-Toner 2 to Toner 13 and Toner 101 to Toner 107-
In the production of toner 1, toner 2 to toner 13 and toner 101 to toner 107 were produced in the same manner except that resin 1 and release agent 1 were changed to the binder resin and release agent shown in Table 3 below, respectively. did.
The toner properties of the obtained toner were evaluated in the same manner. The results are summarized in Table 3.

The glass transition temperatures Tg [° C.] of the resins 1 to 11 were measured by differential scanning calorimetry by the method described above.
When the differential scanning calorimetry is performed on the release agent 1 to release agent 12, the temperature at which the maximum endothermic absorption detected in the range of Tg + 5 ° C. to Tg + 10 ° C. of the resin 1 to resin 11 is detected as T _It is shown in Table 3 as _I [° C.].

Further, the ratio of the endothermic absorption intensity (I) at T _I [° C.] and the endothermic absorption intensity (Ip) at each melting point (I / Ip) is shown in Table 3.

<Image formation>
Images were produced using the obtained toners 1 to 13 and toners 101 to 107 and the following image forming apparatus.

-Image forming device-
As an image forming apparatus, a fixing roll of DocuCenter Color450 (manufactured by Fuji Xerox Co., Ltd.) is a metal roll (surface thermal conductivity: 16 W / m · K, arithmetic average roughness Ra: 1.0 μm, not coated with resin) The toner image adjusted to a toner loading of 5.5 g / m ² was fixed at a process speed of 285 mm / sec and a fixing roll temperature of 190 ° C. using a modified machine changed to a diameter of 35 mm. In the image formation, Premier TCF 80 gsm paper (A3) was used as a recording medium (paper).
The surface roughness of the metal roll was measured using a roughness measuring machine (Surfcom 1400A, manufactured by Tokyo Seimitsu Co., Ltd.). The measurement conditions were JIS'82 standard, measurement length 4.0 mm, cutoff wavelength 0.80 mm, measurement speed 0.30 mm / s, and inclination correction was performed by least square linear correction.

The following images and characters were formed as evaluation toner images.
A 20 × 20 mm solid image on the paper surface 15 mm away from the leading edge in the paper traveling direction and 15 mm away from the left edge in the paper traveling direction. Abbreviated as “solid image”). Also, “FUJIXEROX” (font: Arial, on the paper surface 15 mm away from the rear edge in the paper advance direction in the paper advance direction and 100 mm away from the right edge of the rear edge in the paper advance direction. 16p) characters (the characters are abbreviated as “rear end characters”).

Images were taken out using the image forming apparatus in an office environment (temperature 25 ° C., humidity 50% RH) and a high temperature and high humidity environment (temperature 30 ° C., humidity 85% RH).
Under the above conditions, 100 images are continuously displayed. The first image from the beginning of the image is referred to as an “initial image”, and the 100th image from the beginning of the image is referred to as a “100th image”. That's it.

<Evaluation>
1. Bending strength Premier TCF 80 gsm paper with a fixed solid image is folded at the center of the solid image, and a load of 3 MPa (300 g / cm ² ) is applied to that portion for 10 seconds. Confirmed and evaluated according to the following criteria. The results are shown in Table 3.
(Double-circle): There is no defect | deletion part in the tip solid image of a bending part.
○: Although there is a slight defect in the solid image at the end of the bent portion, there is no problem in actual use.
Δ: The solid image at the tip of the bent portion has a defect portion that is slightly visually confirmed.
X: There is a clear defect in the solid image at the end of the bent portion, which causes a problem in actual use.

2. Offset The offset of Premier TCF 80 gsm paper on which the leading edge solid image and the trailing edge character were fixed was visually confirmed and evaluated according to the following criteria. The results are shown in Table 3.
A: Particularly good peeling, no offset at both the leading solid image and the trailing character part.
○: No offset occurred in the leading solid image and the trailing character part.
(Triangle | delta): The level peeled off by use of a peeling nail and a problem in practical use.
X: Level at which the peeling at the time of fixing is insufficient, causing a problem in practical use.

3. Rubbing image intensity The initial image and the 100th image (both including a leading solid image and a trailing character) were measured using a Vivace 550 (manufactured by Fuji Xerox Co., Ltd .; modified) automatic document feeder. Five originals were set and sent to the apparatus, and image missing / breakage of the second and subsequent originals were visually confirmed, and graded according to the following criteria.
G0: Image missing / no breakage occurred G1: Image missing / breakage that was difficult to visually confirm G2: Minor image loss / breakage confirmed visually G3: Clear image missing / breakage confirmed visually Occurrence

  In Table 3 below, “room” represents an office environment (temperature 25 ° C., humidity 50% RH), and “high” represents a high temperature / humidity environment (temperature 30 ° C., humidity 85% RH).

  From Table 3, it can be seen that if image formation is performed using the toner of the example, the image intensity is less dependent on temperature and humidity than when the toner of the comparative example is used.

1Y, 1M, 1C, 1K Photoconductor 2Y, 2M, 2C, 2K Charging roller 3Y, 3M, 3C, 3K Laser beam 3 Exposure device 4Y, 4M, 4C, 4K Developing device 5Y, 5M, 5C, 5K Primary transfer Rollers 6Y, 6M, 6C, 6K Cleaning devices 8Y, 8M, 8C, 7K Toner cartridges 10Y, 10M, 10C, 10K Image forming unit 20 Intermediate transfer belt 22 Drive roller 24 Support roller 26 Secondary transfer roller 28 Fixing device 30 Intermediate transfer Body cleaning device 107 Photoconductor 108 Charging device 111 Developing device 112 Transfer device 115 Fixing device 116 Mounting rail 117 Opening 118 Opening 119 Housing

Claims (9)

At least a binder resin and a release agent;
The release agent has a maximum endothermic absorption detected by differential scanning calorimetry in a range of 75 ° C. or higher and 90 ° C. or lower. The maximum endothermic absorption intensity (Ip) and the glass transition temperature (Tg) of the binder resin. ) The ratio (I / Ip) to the maximum endothermic absorption intensity (I) detected by differential scanning calorimetry in the range of + 5 ° C. to Tg + 10 ° C. is 0.05 to 0.2 , and the Tg + 5 ° C. the Tg + 10 ° C. or less of the releasing agent der Ru toner for developing electrostatic images having a maximum endothermic absorption in the range above.   The electrostatic image developing toner according to claim 1, wherein the binder resin has a weight average molecular weight of 200,000 or more and 600,000 or less.   The electrostatic charge image developing toner according to claim 1, wherein the binder resin has a glass transition temperature (Tg) of 50 ° C. or more and 70 ° C. or less.   An electrostatic charge image developer comprising the electrostatic charge image developing toner according to any one of claims 1 to 3.   A toner cartridge that contains the electrostatic image developing toner according to any one of claims 1 to 3 and is detachable from an image forming apparatus.   A developing means for accommodating the electrostatic charge image developer according to claim 4 and developing the electrostatic charge image formed on the image holding member as a toner image by the electrostatic charge image developer, is attached to and removed from the image forming apparatus. Process cartridge. An image carrier,
Charging means for charging the surface of the image carrier;
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged photoreceptor;
Developing means for developing the electrostatic charge image formed on the image carrier as a toner image with the electrostatic charge image developer according to claim 4;
Transfer means for transferring the toner image formed on the image carrier onto a recording medium;
Fixing means for fixing the toner image transferred onto the recording medium;
An image forming apparatus comprising:   The fixing unit includes a fixing member and a pressure member provided in contact with the fixing member, and the fixing member has a surface thermal conductivity of 1 W / m · K to 1,000 W / m · K. The image forming apparatus according to claim 7.   The image forming apparatus according to claim 7, wherein the fixing member is a metal member.

Images