JP2010091838A - Toner for developing static charge image, and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method, improving the production efficiency, and easily manufacturing a toner having superior low-temperature fixability and offset ability, and further enlarged fixing temperature range to obtain high gloss. <P>SOLUTION: This method of manufacturing toner for developing static charge images, at least includes: a process of heating, melting and kneading binder resin, radiation crosslink monomer compatible with the binder resin and a coloring agent; a process of forming a thin film of the kneaded material, obtained by kneading to have a film thickness equal to or more than an average particle diameter of toner and 12 μm or less; a process of applying radial rays to the thin film obtained by the above thin-film formation, at a temperature equal to or lower than the glass transition point of the kneaded material +5°C or more and +30°C or less to bridge the radiation crosslink monomer; and a process of grinding and classifying the thin film subjected to application of radial rays to obtain toner particles. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electrostatic image developing toner used in an image forming method for developing an electrostatic latent image in electrophotography, electrostatic recording, electrostatic printing, and the like. The present invention relates to a toner for developing an electrostatic charge image, which provides a production method for dramatically improving the dispersion state of the agent, provides a stable image excellent in color tone reproducibility and offset resistance in image quality, and a method for producing the same.

Conventionally, as an electrophotographic method, many methods are known as described in Patent Documents 1 to 3. In general, a photoconductive substance is used to form an electrical latent image on a photoreceptor by various means, and then the latent image is developed with toner, and a toner image is formed on a transfer material such as paper as necessary. After the toner is transferred, the toner image is fixed by heating, pressure, heating and pressing, or solvent vapor.
Various methods and apparatuses have been developed for fixing the toner image on a sheet such as paper, which is the final step described above. Currently, the most common method is a pressure heating method using a heat roller.

  In the pressure heating method using a heating roller, the toner image is fixed by allowing the surface of the heat roller having releasability to the toner and the toner image surface of the fixing sheet to contact each other under pressure while passing through the fixing sheet. Is. In this method, since the surface of the heat roller and the toner image on the fixing sheet are in contact with each other under pressure, the thermal efficiency when fusing the toner image on the fixing sheet is extremely good, and the fixing is performed quickly. Can do.

  However, at present, different toners are used depending on the type of copying machine or printer. This is mainly due to the difference in fixing speed and fixing temperature. Since the surface of the heating roller and the toner image are in a molten state and are in contact with each other under pressure, a part of the toner image adheres to the surface of the fixing roller and transfers, and this re-transfers to the next fixing sheet and stains the fixing sheet. This is because the offset phenomenon is greatly affected by the fixing speed and fixing temperature. Generally, when the fixing speed is low, the surface temperature of the heating roller is low, and when the fixing speed is high, the surface temperature of the heating roller is set high. This is because the amount of heat given to the toner by the heating roller for fixing the toner is made almost constant regardless of the fixing speed.

  However, since the toner on the fixing sheet forms several toner layers, the fixing speed is particularly fast, and in a system with a high heating roller temperature, the toner layer that contacts the heating roller contacts the fixing sheet. The temperature difference between the lowermost toner layers is very large. For this reason, when the temperature of the heating roller is high, the toner on the uppermost layer causes an offset phenomenon, whereas when the temperature of the heating roller is low, the toner on the lowermost layer does not melt sufficiently, The toner is not fixed and a phenomenon of low temperature offset occurs.

  As a method for solving this problem, when the fixing speed is high, a method of increasing the pressure during fixing and anchoring the toner to the fixing sheet is usually performed. With this method, the temperature of the heating roller can be lowered to some extent, and the high-temperature offset phenomenon of the uppermost toner can be prevented. However, since the shearing force applied to the toner becomes very large, the fixing sheet is wound around the fixing roller, the winding offset, or the separation of the member (for example, the separation claw) that separates the fixing sheet from the fixing roller. Appears in the image, and the pressure is high, the line image is crushed at the time of fixing, or the toner jumps, so that the image quality of the fixed image is likely to deteriorate.

  Therefore, in general, high-speed fixing uses toner having a lower melt viscosity than in low-speed fixing, and lowers the heating roller temperature and fixing pressure to fix the toner while preventing high temperature offset and winding offset. However, when such a low melt viscosity toner is used for low-speed fixing, an offset phenomenon tends to occur at a high temperature because of its low viscosity.

  Usually, as a method for reducing the viscosity of a toner, a method of lowering the glass transition point of the polymer or a method of lowering the molecular weight of the polymer can be mentioned. However, in the former method, the storage stability is lowered, and in the latter method, high temperature offset resistance and frictional charging characteristics are lowered, and further, the toner is easily fused to the photosensitive member. In vinyl resin, as a method for increasing the degree of branching of a polymer, Patent Document 4 and Patent Document 5 propose a method using a macromonomer, and Patent Document 6 proposes a method using an ε'-caprolactone-modified hydroxyvinyl monomer. Yes.

  However, when many macromonomers are used in order to increase the degree of branching by these methods, the glass transition temperature of the resin is lowered and the storage stability is lowered. To maintain good storage stability of the toner, increase the molecular weight of the polymer main chain and increase the glass transition temperature of the polymer main chain, or change the monomer composition of the polymer main chain to increase the molecular weight. There is a method of increasing only the glass transition temperature without changing. However, in either of these methods, the fixing temperature rises and the effect of fixing the toner at a low temperature by increasing the degree of branching is small. This is because it is greatly affected by the composition distribution of the macromonomer in the polymer. When a large number of macromonomers are polymerized in the polymer chain, this polymer deteriorates the storage stability. Therefore, in order to improve the storage stability of this polymer, the glass transition temperature of the main chain must be increased excessively for some polymers in which many macromonomers are unevenly distributed. Sex is reduced. The glass transition temperature in the main chain and the glass transition temperature in the side chain are so different that the effect of lowering the viscosity due to branching is offset by the increase in viscosity due to the increase in the glass transition temperature of the main chain.

  In a polyester resin, as a method for increasing the degree of branching, a method using a trivalent or higher polyvalent carboxylic acid or polyhydric alcohol, or using a dicarboxylic acid having a side chain or a diol having a side chain is disclosed in Patent Document 7. And Patent Document 8 proposed. Since dicarboxylic acids and diols having side chains are side chains of aliphatic groups, like the vinyl resin, this side chain lowers the glass transition temperature of the polymer and increases the degree of branching. The effect of lowering the viscosity is lost by raising the glass transition temperature of the main chain. In the method using a trivalent or higher polyvalent carboxylic acid or polyhydric alcohol, the degree of branching is increased, but the gel content (THF insoluble content) is increased and the high temperature offset resistance is improved, but the fixing temperature is increased.

Patent Documents 9 to 11 propose a method of blending and using two types of non-linear polyesters having different softening points, and Patent Document 12 discloses a method of using a resin composed of high-density crosslinked microgel particles including a linear part and a crosslinked part. Has been proposed.
In the former, since the divalent carboxylic acid and divalent alcohol and the trivalent or higher polyvalent carboxylic acid or polyhydric alcohol are charged into the container at the same time and synthesized, it is very difficult to adjust the degree of branching.

  Conventionally, in the heating roller fixing method, in order to prevent toner from adhering to the surface of the fixing roller, for example, the surface of the fixing roller is formed of a material having excellent releasability from toner such as fluorine resin, and further on the surface. An offset prevention liquid such as silicone oil is supplied to coat the roller surface with a thin liquid film. This method is extremely effective in preventing the offset of the toner. However, since the offset prevention liquid is heated, an odor is generated, and an apparatus for supplying the offset prevention liquid is required. The mechanism of the copying apparatus becomes complicated, and high accuracy is required to obtain a stable image, so that the copying apparatus is expensive.

  Several proposals have been made for such conventional problems. For example, Patent Document 13 proposes a method in which a release agent is internally added at an appropriate ratio inside the toner granules, and an external release agent is added at an appropriate ratio on the surface of the toner granules. In this method, it is possible to give the toner releasability, but since the release agent is externally added to the toner surface, the fluidity and storage stability are clearly inferior, and the toner has a uniform charge distribution. Since it becomes difficult to obtain a developer, the image quality is also problematic. Furthermore, Patent Document 14 stipulates that the dispersion diameter of the low molecular weight wax in the binder resin is 1 μm or less, but in order to obtain a desired dispersion diameter, a method of kneading for a long time with a large shearing force is proposed. ing. This method aims to suppress the offset phenomenon by defining the dispersion diameter of the release agent, but it requires a large shearing force, so that the production equipment that can be used is limited, and the kneading time is very long. Since it becomes long, it is also very disadvantageous in productivity.

  In recent years, the colorization of electrophotographic systems has progressed, and the demand for high image quality and high reproducibility has increased. For full-color electrophotographic toners, toners colored yellow, magenta, and cyan are used. Black toner is also used as necessary. In such a color toner, it is essential that the fixed toner has good spectral reflection characteristics that do not diffusely reflect, and that the superimposed toner has transparency in order to reproduce any color tone. It is indispensable to improve the dispersion of the colorant in the binder resin.

In general, toner is obtained by melting and kneading predetermined materials such as binder resin, colorant (dye, pigment, magnetic substance, etc.), charge control agent, etc., solidifying after cooling, and classifying finely pulverized pulverized product. In order to give fluidity to the fine particle powder obtained in this way, an additive (such as ultrafine colloidal silica) is added and mixed by stirring. A conventional melt kneading method uses a screw-type extrusion continuous kneader, a two-roll mill, a three-roll mill, a pressure heating kneader, or the like.
The dispersion state of the colorant in the binder resin depends on this kneading step. When the dispersion of the colorant is insufficient, the color toner obtained has a low degree of color, the color is not vivid, and it is not transparent. As a result, the color reproducibility is extremely poor. In the general melt-kneading method as described above, the dispersion of the colorant in the binder resin is at an insufficient level, and it becomes difficult to obtain good image quality. The so-called master batch method has been proposed for such a conventional problem.

  For example, in Patent Document 15, a solvent is added to a part of the binder resin and the dye / pigment and melt-kneaded in advance, and the obtained kneaded product is cooled and pulverized to form a master batch, and the binder resin and the obtained master batch again. There has been proposed a method of melt kneading. This method aims to improve the dispersibility of the dye / pigment in the binder resin by adding a solvent. However, since the kneading temperature at the time of obtaining the masterbatch is high, the viscosity of the kneaded product is lowered and Dispersion is not greatly improved, and there is a drawback that it takes a long time to obtain a desired dispersion level. Further, Patent Document 16 proposes a method in which a mixture of a binder resin, a charge control agent and a colorant is kneaded in advance with an organic solvent at a temperature lower than the melting temperature of the binder resin. In the dispersion of the mold release agent, there is a problem that residual solvent remains in the obtained kneaded product and odor is generated during actual use, and in order to remove the residual solvent, it is eventually necessary to heat to a high temperature. The effect is not obtained. In addition, since the kneading for obtaining the master batch is a batch process, there is a concern about a decrease in productivity.

US Pat. No. 2,297,691 Japanese Patent Publication No.42-23910 Japanese Patent Publication No.43-24748 Japanese Patent Laid-Open No. 3-87753 JP-A-3-203746 JP-A-4-24648 JP 59-228658 A JP-A-62-2195678 JP-A-63-225244 JP-A-63-225245 JP-A-63-225246 JP-A-5-249736 Japanese Patent Laid-Open No. 2-235067 JP-A-3-168649 Japanese Patent Laid-Open No. 3-155568 JP-A-8-123076

  The present invention has been made in view of such a current situation, and has improved the production efficiency, has excellent low-temperature fixability and offset properties, and has further expanded the fixing temperature range capable of obtaining high gloss. An object of the present invention is to provide a production method and a toner capable of easily producing the toner.

As a result of continuous studies to solve the above-described conventional problems, the present inventors have easily and dramatically improved the dispersion of the colorant and the release agent in the binder resin, A method that drastically reduces the manufacturing energy required during kneading, a method that makes it possible to shorten the manufacturing process by not using the master batch method, and the obtained kneaded material has excellent thermal properties (low-temperature fixability, offset property). In addition, the inventors have found a method that can be modified so that the fixing temperature range that can obtain high gloss can be expanded.
That is, in a method for producing a toner for developing an electrostatic charge image having toner particles containing at least a binder resin and a colorant, at least a radiation curable monomer compatible with the binder resin, the binder resin, and the colorant are heated, melted and kneaded. Electrostatic charge image development characterized in that it is produced by reducing the thickness of the kneaded product after kneading and maintaining the glass transition point + 5 ° C. + glass transition point + 30 ° C., and pulverizing and classifying the irradiated thin film. The manufacturing method of the toner was found.
The present invention is a method for producing a toner for developing an electrostatic image as described below, and a toner produced by this production method.

(1) at least a step of heating and kneading a binder resin, a radiation crosslinking monomer compatible with the binder resin, and a colorant;
A step of thinning the kneaded product obtained by the kneading so as to have a film thickness of not less than the average particle diameter of the target toner and not more than 12 μm;
A step of crosslinking the radiation-crosslinking monomer by irradiating the thin film obtained by the thinning with radiation at a glass transition point of the kneaded product of + 5 ° C. or higher and + 30 ° C. or lower;
Crushing and classifying the thin film after radiation irradiation to obtain toner particles;
A method for producing a toner for developing an electrostatic charge image, comprising:
(2) At least a binder resin, a radiation crosslinking monomer compatible with the binder resin, a colorant, and a release agent are heated and melt-kneaded at a temperature equal to or lower than the melting point of the release agent;
A step of thinning the kneaded product obtained by the kneading so as to have a film thickness of not less than the average particle diameter of the target toner and not more than 12 μm;
A step of crosslinking the radiation-crosslinking monomer by irradiating the thin film obtained by thinning in the previous period with radiation at a temperature not higher than the melting point of the release agent and not lower than the glass transition point of the kneaded product + 5 ° C. + 30 ° C .;
Crushing and classifying the thin film after radiation irradiation to obtain toner particles;
A method for producing a toner for developing an electrostatic charge image, comprising:
(3) The toner for developing an electrostatic charge image according to (1) or (2), wherein the release agent does not dissolve in the radiation crosslinking monomer and has a melting point of 60 ° C. or higher and 100 ° C. or lower. Manufacturing method.
(4) An electrostatic image developing toner containing at least a binder resin and a colorant obtained by any one of the production methods according to (1) to (3).
(5) The electrostatic charge image according to (4), wherein the binder resin has a high molecular weight body having a molecular weight of 50,000 or more obtained by radiation-crosslinking a linear resin not containing a gel component and a radiation crosslinking monomer. Development toner.
(6) The electrostatic charge image developing toner according to (4) or (5), wherein the linear resin is a polyester resin. (7) Weight ratio of the linear resin and the radiation crosslinking monomer. The toner for developing an electrostatic charge image according to any one of (4) to (6), wherein the toner is 92.5: 7.5 to 97.5: 2.5.
(8) An electrophotographic image forming apparatus using the electrostatic image developing toner according to any one of (4) to (7).
(9) A process cartridge comprising the electrostatic image developing toner according to any one of (4) to (7).
The above inventions (1) to (10) are hereinafter referred to as aspects 1 to 10 of the invention.

According to the aspect (1) of the invention, by mixing a radiation curable monomer that is compatible with the binder resin, the binder resin portion gives a sufficient shearing force to the colorant at a low temperature and becomes a viscosity that can be uniformly dispersed. The kneading temperature is drastically reduced. VOCs are not generated by thinning and radiation cross-linking at the above temperature, and the pulverization efficiency can be improved by adjusting the thickness as a film.
Furthermore, the obtained kneaded material has improved thermal properties at high temperatures, and it is possible to obtain a toner having excellent offset properties.
In addition, since the film thickness is appropriate, radiation crosslinking can be performed satisfactorily, and the pulverization efficiency is improved by combining the average toner particle diameter and the film thickness.
According to the aspect (2) of the invention, since the kneading can be performed at a temperature lower than the release agent dissolution temperature with respect to the dispersion of the release agent, coarsening of the dispersed particle size due to recrystallization of the melted release agent component is prevented. It is possible to obtain excellent release properties without deteriorating charging characteristics and fluidity.
According to aspects (3) and (4) of the invention, the dispersibility of the release agent in the toner can be improved.
The toner according to the aspect (5) of the invention has excellent low-temperature fixability and offset property because the colorant or the colorant and the release agent are well dispersed in the toner.
According to the aspect (6) of the invention, it is possible to obtain a toner having high gloss and resistance to hot offset.
According to the aspect (7) of the invention, both the pulverization property and the low-temperature fixability can be achieved by using the linear resin as a polyester resin.
According to the aspect (8) of the invention, when the monomer amount is appropriate, the pulverization property, offset property, glossiness, and storage property of the toner are good.

Hereinafter, each component constituting the electrostatic image developing toner of the present invention will be described.
(Binder resin)
The binder resin is not particularly limited, and a commonly used resin can be appropriately selected and used.
Examples of the resin used in the present invention include vinyl polymers such as styrene monomers, acrylic monomers and methacrylic monomers, copolymers of these monomers or two or more types, polyesters Examples thereof include a polymer, a polyol resin, a phenol resin, a silicone resin, a polyurethane resin, a polyamide resin, a furan resin, an epoxy resin, a xylene resin, a terpene resin, a coumarone indene resin, a polycarbonate resin, and a petroleum resin.

  Examples of the styrene monomer include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, and pn-. Amyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene , Styrene such as p-chlorostyrene, 3,4-dichlorostyrene, m-nitrostyrene, o-nitrostyrene, p-nitrostyrene, or derivatives thereof.

  Examples of the acrylic monomer include acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-octyl acrylate, n-dodecyl acrylate, and acrylic. Examples include 2-ethylhexyl acid, stearyl acrylate, 2-chloroethyl acrylate, acrylic acid such as phenyl acrylate, or esters thereof.

  Examples of the methacrylic monomer include methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, n-dodecyl methacrylate, and methacrylic acid. And methacrylic acid or esters thereof such as 2-ethylhexyl, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and the like.

The following (1)-(18) is mentioned as an example of the other monomer which forms the said vinyl polymer or a copolymer.
(1) Monoolefins such as ethylene, propylene, butylene and isobutylene; (2) Polyenes such as butadiene and isoprene; (3) Vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide and vinyl fluoride; (4) Vinyl esters such as vinyl acetate, vinyl propionate and vinyl benzoate; (5) Vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; (6) Vinyl methyl ketone, vinyl hexyl ketone and methyl. Vinyl ketones such as isopropenyl ketone; (7) N-vinyl compounds such as N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone; (8), vinyl naphthalenes; (9) acrylonitrile, Such as methacrylonitrile, acrylamide, etc. (10) unsaturated dibasic acids such as maleic acid, citraconic acid, itaconic acid, alkenyl succinic acid, fumaric acid, mesaconic acid; (11) maleic anhydride, citraconic anhydride, Unsaturated dibasic acid anhydrides such as itaconic anhydride and alkenyl succinic anhydride; (12) maleic acid monomethyl ester, maleic acid monoethyl ester, maleic acid monobutyl ester, citraconic acid monomethyl ester, citraconic acid monoethyl ester Monoesters of unsaturated dibasic acids such as citraconic acid monobutyl ester, itaconic acid monomethyl ester, alkenyl succinic acid monomethyl ester, fumaric acid monomethyl ester, mesaconic acid monomethyl ester; (13) dimethylmaleic acid, dimethylfumaric acid, etc. (14) α, β-unsaturated acids such as crotonic acid and cinnamic acid; (15) α, β-unsaturated acid anhydrides such as crotonic acid anhydride and cinnamic anhydride; 16) Monomers having a carboxyl group such as anhydrides of the α, β-unsaturated acids and lower fatty acids, alkenylmalonic acid, alkenylglutaric acid, alkenyladipic acid, acid anhydrides and monoesters thereof; ) Acrylic acid or methacrylic acid hydroxyalkyl esters such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate; (18) 4- (1-hydroxy-1-methylbutyl) styrene, 4- (1 Monomers having a hydroxy group such as hydroxy-1-methylhexyl) styrene.

  In the electrostatic image developing toner of the present invention, the vinyl polymer or copolymer of the binder resin may have a crosslinked structure crosslinked with a crosslinking agent having two or more vinyl groups. In some cases, the viscosity may increase.

  In the toner production method of the present invention, when the binder resin is a styrene-acrylic resin, the molecular weight distribution is measured by GPC, which is a component soluble in tetrahydrofuran (THF) as a resin component (THF soluble component). A resin having a peak in the region of 3,000 to 50,000 (in terms of number average molecular weight) is preferable in terms of grindability and storage stability. A binder resin having a main peak in the molecular weight region of 5,000 to 30,000 is more preferable, and a binder resin having a main peak in the region of 5,000 to 20,000 is most preferable.

  The acid value when the binder resin is a vinyl polymer such as styrene-acrylic resin is preferably 0.1 mgKOH / g to 100 mgKOH / g, and preferably 0.1 mgKOH / g to 70 mgKOH / g. More preferably, it is most preferably 0.1 mgKOH / g to 50 mgKOH / g.

  The following are mentioned as a monomer which comprises a polyester-type polymer. Examples of the divalent alcohol component include ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, hydrogenated bisphenol A, or diol obtained by polymerizing cyclic ethers such as ethylene oxide and propylene oxide to bisphenol A, etc. Is mentioned.

  In order to crosslink the polyester resin, it is preferable to use a trivalent or higher alcohol together. Examples of the trihydric or higher polyhydric alcohol include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, such as dipentaerythritol, tripentaerythritol, 1,2,4- Butanetriol, 1,2,5-pentatriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxybenzene , Etc.

  Examples of the acid component that forms the polyester polymer include benzene dicarboxylic acids such as phthalic acid, isophthalic acid, and terephthalic acid or anhydrides thereof, alkyldicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and azelaic acid, or Unsaturated dibasic acids such as anhydride, maleic acid, citraconic acid, itaconic acid, alkenyl succinic acid, fumaric acid, mesaconic acid, maleic anhydride, citraconic anhydride, itaconic anhydride, alkenyl succinic anhydride And unsaturated dibasic acid anhydrides. Examples of the trivalent or higher polyvalent carboxylic acid component include trimet acid, pyromet acid, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxy-2-methyl-2-methylenecarboxypropane, tetra (methylene Carboxy) methane, 1,2,7,8-octanetetracarboxylic acid, empol trimer acid, or anhydrides thereof, partial lower alkyl esters, and the like.

When the binder resin is a polyester resin, the molecular weight distribution of the THF soluble component of the resin component has a peak in the region of a molecular weight of 3,000 to 30,000 in terms of toner fixability and offset resistance. Preferably, the THF-soluble component is preferably a binder resin that does not contain a component having a molecular weight of 100,000 or less, and more preferably a binder resin having a peak in the region of a molecular weight of 5,000 to 20,000.
When the molecular weight is 50,000 or less, the grindability is improved, and a high-gloss image can be obtained by preventing the viscosity at high temperature from becoming too high, but the fixing temperature range for obtaining a high-gloss image is narrowed. . According to the configuration of the present invention, it is possible to expand the fixing temperature range in which a high gloss image can be obtained.

When the binder resin is a polyester resin, the acid value is preferably 0.1 mgKOH / g to 100 mgKOH / g, more preferably 0.1 mgKOH / g to 70 mgKOH / g, and 0.1 mgKOH / g. Most preferably, it is g-50 mgKOH / g.
In the present invention, the molecular weight distribution of the binder resin is measured by gel permeation chromatography (GPC) using THF as a solvent.

In the present invention, the acid value of the binder resin component of the toner composition is determined by the following methods (I) to (IV), and the basic operation conforms to JIS K-0070.
(I) The sample is used by removing additives other than the binder resin (polymer component) in advance, or the acid value and content of components other than the binder resin and the crosslinked binder resin are obtained in advance. . The sample pulverized product 0.5 to 2.0 g is precisely weighed, and the weight of the polymer component is defined as Wg. For example, when measuring the acid value of the binder resin from the toner, the acid value and content of the colorant or magnetic material are separately measured, and the acid value of the binder resin is obtained by calculation.
(II) A sample is put into a 300 (ml) beaker, and a mixed solution 150 (ml) of toluene / ethanol (volume ratio 4/1) is added and dissolved.
(III) Titrate with a potentiometric titrator using an ethanol solution of 0.1 mol / l KOH.
(IV) The amount of use of the KOH solution at this time is S (ml), a blank is measured at the same time, and the amount of use of the KOH solution at this time is B (ml), which is calculated by the following formula (1). However, f is a factor of KOH.
Acid value (mgKOH / g) = [(SB) × f × 5.61] / W (1)

  The toner binder resin and the composition containing the binder resin preferably have a glass transition temperature (Tg) of 40 to 80 ° C., more preferably 50 to 75 ° C., from the viewpoint of toner storage stability. When Tg is lower than 40 ° C., the toner may be easily deteriorated in a high temperature atmosphere. On the other hand, when Tg exceeds 80 ° C., fixability may be deteriorated.

(Coloring agent)
The colorant is not particularly limited and may be appropriately selected from commonly used resins. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Lead Red, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Fu Issey Red, Parachlor Ortho Nitroaniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmin Min BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Risor Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon, Oil Red, Nacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), Indigo, Ultramarine Blue, Bitumen, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chrome Oxide , Pyridian, emerald green, pigment green B, naphthol green B, green gold, acid green , Malachite green lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc white, litbon and mixtures thereof.

The content of the colorant is preferably 1 to 15% by mass and more preferably 2 to 10% by mass with respect to the toner.
The surface of the colorant may be subjected to surface treatment such as acid treatment or alkali treatment depending on the binder resin used. Surface treatment improves wettability with the binder resin and improves dispersibility.
In the present invention, it is preferable to use a colorant that has been subjected to a surface treatment that improves wettability with the radiation crosslinking monomer.

The particle size of the colorant in the dispersion after dispersing the colorant is desirably 400 nm or less. If it is larger than 400 nm, the image quality is deteriorated, and in particular, the optical transparency of OHP tends to be lowered. More preferably, it is 200 nm or less. Below 3200 nm, the light transmission is remarkably improved and the color reproduction range is greatly improved.
The dispersion diameter of the colorant in the binder resin can be measured by various methods. The kneaded and cooled product after being kneaded is sliced to a thickness of 1000 mm by a microtome MT-6000 (manufactured by RMMC Inc.) and transmitted. Observation was made with an electron microscope JSM-880 (manufactured by JEOL Ltd.), and at least 300 particle sizes were measured with an image analyzer LUZEX500 (manufactured by Nireco Corp.) via a scanning converter unit. The particle diameter of the toner colorant is the average value of the long sides of the pigment particles.

(Release agent)
In the toner of the present invention, in order to give releasability, in addition to synthetic waxes such as low molecular weight polyethylene and polypropylene as a release agent, candelilla wax, carnauba wax, rice wax, wax, jojoba Plant waxes such as oil; animal waxes such as beeswax, lanolin and whale wax; mineral waxes such as montan wax and ozokerite; fat waxes such as hardened castor oil, hydroxystearic acid, fatty acid amide, phenol fatty acid ester If necessary, these may be contained alone or in combination of two or more.

  Further, in the present invention, the release agent is not particularly limited, but contains a release agent having a melting point in the range of 60 to 120 ° C, preferably contains a release agent in the range of 70 to 100 ° C. Is desirable. If only a release agent with a melting point lower than 60 ° C is contained, dissolution will occur when stored at high temperatures or when mechanical shear is received due to frictional charging in the development unit, affecting fluidity and charging characteristics. give. In addition, in a toner containing only a release agent having a melting point higher than 120 ° C., it is difficult to obtain a desired release effect, and it is necessary to increase the fixing temperature in order to obtain the release effect, and an increase in power consumption is avoided. I can't.

  The dispersed particle size of the dispersed release agent can be measured by the same method as described for the colorant, but an accurate particle size can be measured by subjecting the sliced measurement sample to ruthenium treatment. The particle size of the toner release agent is the average value of the long sides of the pigment particles.

<Radiation crosslinking monomer>
Radiation crosslinking monomers used in the present invention include urethane acrylate, epoxy acrylate, polyester acrylate, polyether acrylate, vinyl, unsaturated polyester oligomers and various polyfunctional acrylates, methacrylates, vinyl esters, ethylene derivatives. And monomers such as allyl compounds. Specific examples include the following.

<Example of bifunctional monomer>
1,4-butanediol acrylate 1,6-hexanediol diacrylate 1,9-nonanediol diacrylate neopentyl glycol diacrylate tetraethylene glycol diacrylate tripropylene glycol diacrylate tripropylene glycol diacrylate polypropylene glycol diacrylate bisphenol A. EO Adduct Diacrylate Glycerin Methacrylate Acrylate Propylene Oxide of Neopentyl Glycol 2 Moleate Diacrylate Diethylene Glycol Diacrylate Polyethylene Glycol (400) Diacrylate Diacrylate of Hydroxypivalic Acid and Neopentyl Glycol 2,2-Bis (4- Acryloxy diethoxyphenyl) propane Diacrylate of neopentyl glycol adipate Diacrylate of ε-caprolactone adduct of neopentyl glycol hydroxypivalate Diacrylate of ε-caprolactone adduct of neopentyl glycol hydroxypivalate 2- (2-hydroxy) -1,1-dimethylethyl) -5-hydroxymethyl-5-ethyl-1,3-dioxanedia Relate tricyclodecane dimethylol diacrylate tricyclodecane dimethylol diacrylate ε- caprolactone adduct of 1,6-diacrylate diglycidyl ethers of hexanediol

<Example of polyfunctional monomer>
Trimethylolpropane triacrylate Pentaerythritol triacrylate Triglycerin PO-added triacrylate Trisacryloyloxyethyl phosphate Pentaerythritol tetraacrylate Triacrylate of trimethylolpropane propylene oxide 3 mol adduct Glyceryl propoxytriacrylate Dipentaerythritol polyacrylate Dipentaerythritol Propionic acid / dipentaerythritol triacrylate Hydroxypivalaldehyde-modified dimethylolpropyne triacrylate Propionic acid / dipentaerythritol tetraacrylate Ditrimethylolpropane tetraacrylate Propionate dipentaerythritol pen Taacrylate Dipentaerythritol hexaacrylate (DPHA)
Ε-caprolactone adduct of DPHA <Example of oligomer>
Bisphenol A-diepoxyacrylic acid adduct

These radiation crosslinking monomers are used alone or in admixture of two or more.
Among the radiation crosslinking monomers, a material that dissolves or swells the binder resin is selected. The binder resin is plasticized when mixed with the selected radiation crosslinking monomer and added amount, and the apparent Tg and the viscosity at the time of heat-kneading can be adjusted.
It is preferable that a low-viscosity bifunctional or lower radiation crosslinking monomer that functions as a diluent and a high-viscosity polyfunctional crosslinking agent are appropriately mixed and used.

In the present invention, it is preferable to use an electron beam for radiation crosslinking, but it is also possible to use ultraviolet rays. When ultraviolet rays are used, it is necessary to mix a photopolymerization initiator.
Examples of photopolymerization initiators include, but are not limited to, the following.
1. Benzoin ether Isobutyl benzoin ether Isopropyl benzoin ether Benzoin ethyl ether Benzoin methyl ether α-Acyloxime ester 1-phenyl-1,2-propanedione-2- (o-ethoxysicarbonyl) oxime3. Benzyl ketal 2,2-dimethoxy-2-phenylacetophenone benzyl hydroxycyclohexyl phenyl ketone4. 4. Acetophenone derivative Diethoxyacetophenone 2-hydroxy-2-methyl-1-phenylpropan-1-one Ketone-(ketone-amine system)
Benzophenone Chlorothioxanthone 2-Chlorothioxanthone Isopropylthioxanthone 2-Methylthioxanthone Chlorine-substituted benzophenone

  These photopolymerization initiators are used alone or in combination of two or more. The addition amount is preferably 0.005 to 1.0 part by weight, more preferably 0.01 to 0.5 part by weight, based on 1 part by weight of the crosslinking agent.

In the present invention, a photopolymerization accelerator can be used together with the photopolymerization initiator.
The photopolymerization accelerator used in the present invention has an effect of improving the curing rate with respect to a hydrogen abstraction type photopolymerization initiator such as benzophenone or thioxanthone. For example, an aromatic tertiary class There are amines and aliphatic amines. Specific examples include P-dimethylaminobenzoic acid isoamyl ester, P-dimethylaminobenzoic acid ethyl ester, and the like.
These photopolymerization accelerators are used alone or in combination of two or more. The addition amount is preferably 0.1 to 5 parts by weight, more preferably 0.3 to 3 parts by weight, relative to 1 part by weight of the photopolymerization initiator.

(Other materials)
As materials other than the resin, the release agent, and the colorant, inorganic fine particles can be used as an external additive for imparting fluidity, developability, chargeability and the like to the toner particles.
The inorganic fine particles are not particularly limited and may be appropriately selected from known ones according to the purpose. For example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, titanate Strontium, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, carbonized Examples include silicon and silicon nitride. These may be used individually by 1 type and may use 2 or more types together.

The primary particle diameter of the inorganic fine particles is preferably 5 nm to 2 μm, and more preferably 5 nm to 500 nm. The specific surface area of the inorganic fine particles by BET method is preferably 20 to 500 m ² / g.
The content of the inorganic fine particles in the electrostatic image developing toner is preferably 0.01 to 5.0% by mass, more preferably 0.01 to 2.0% by mass.

  The fluidity improver means a material that can be surface treated to increase hydrophobicity and prevent deterioration of flow characteristics and charging characteristics even under high humidity. For example, a silane coupling agent, a silylating agent, Examples thereof include a silane coupling agent having an alkyl fluoride group, an organic titanate coupling agent, an aluminum coupling agent, silicone oil, and modified silicone oil. It is particularly preferable that the silica and the titanium oxide are surface-treated with such a fluidity improver and used as hydrophobic silica and hydrophobic titanium oxide.

  The cleaning improver is added to the toner in order to remove the developer after transfer remaining on the photoreceptor or the primary transfer medium, and includes, for example, fatty acid metal salts such as zinc stearate, calcium stearate, stearic acid, and the like. Examples thereof include polymer fine particles produced by soap-free emulsion polymerization such as methyl methacrylate fine particles and polystyrene fine particles. The polymer fine particles preferably have a relatively narrow particle size distribution, and those having a volume average particle size of 0.01 to 1 μm are suitable.

  The toner of the present invention can be mixed with a charge control agent as necessary. Examples include nigrosine dyes, quaternary ammonium salts, amino group-containing polymers, metal-containing azo dyes, salicylic acid complex compounds, phenol compounds, and the like.

(Toner production method)
FIG. 1 shows a flow of the manufacturing method of the present invention. In the production method of the present invention, as shown in FIG. 1, a step of kneading a toner composition to obtain a kneaded product, a step of forming a kneaded product into a thin film, and radiation crosslinking by irradiating the thin film with electron beams or ultraviolet rays A step, a step of pulverizing and classifying the crosslinked thin film, and a step of externally adding an external additive to the obtained toner base particles as necessary.
FIG. 2 is a chart showing an example of the molecular weight distribution of the toner base particles thus obtained. As shown in the figure, the molecular weight distribution of the toner obtained by radiation crosslinking shows a peak derived from a linear binder resin and a peak derived from a radiation crosslinking monomer after crosslinking.

In the toner production method of the present invention, a binder resin, a colorant, a radiation crosslinking monomer and the like are added so as to have an appropriate ratio, a screw-type extrusion continuous kneader, a two-roll mill, a three-roll mill, and pressure heating. Melt-kneading is performed using a kneader.
The kneaded product is stretched under pressure with a pressure roller or the like to form a thin film, and after radiation cross-linking with an electron beam or the like, it is cooled and solidified.
Further, rough pulverization is performed using a pulverizer such as a hammer mill, pulverization is performed using a jet mill pulverizer, and then surface treatment is performed using a rotor pulverizer connected to an airflow classifier or the like. By this surface treatment, the corners of the toner are scraped off and rounded to prevent generation of fine powder in the developing device and improve the transfer rate. Examples of the collision type pulverizer include a hammer mill, a ball mill, a tube mill, and a vibration mill. One type and an IDS type collision type as a jet type pulverizer having a compressed air and a collision plate as main components. A pulverizer (manufactured by Nippon Pneumatic Industry Co., Ltd.) can be preferably used.

Examples of the rotor pulverizer include a roll mill, a pin mill, a fluidized bed jet mill, and the like. In particular, the rotor pulverizer includes a fixed container as an outer wall and a rotating piece having the same central axis as the fixed container as main components. Turbo mills (manufactured by Turbo Industry Co., Ltd.), kryptron (manufactured by Kawasaki Heavy Industries, Ltd.), fine mills (manufactured by Nippon Pneumatic Industrial Co., Ltd.), etc. can be used as rotor type crushers. A John separator (DS) classifier (manufactured by Nippon Pneumatic Industrial Co., Ltd.), a multi-part classifier (Elbow Jet; manufactured by Nittetsu Mining Co., Ltd.), and the like can be used.
Furthermore, fine powder classification can be performed using an airflow classifier or a mechanical classifier to obtain fine particles. If necessary, a fluidity imparting agent can be added to and mixed with the fine particles.

Next, the toner production method of the present invention will be described in more detail.
The toner of the present invention can be produced by kneading a mixture of a binder resin, a colorant, and a radiation crosslinking monomer. At this time, the radiation crosslinking monomer dissolves or swells the binder resin and is suitable for kneading. The heating temperature up to the viscosity can be greatly reduced. Further, it is based on the knowledge that the dispersion of the colorant in the binder resin is dramatically improved by the radiation monomer also functioning as a colorant dispersant.
The fact that the radiation monomer functions as a dispersion aid means that the radiation cross-linking monomer wets and penetrates the interface of the primary particles of the aggregated colorant, so that the aggregate is rapidly released, and even when the shearing force is low, the high concentration into the binder resin is achieved. It can be decentralized.
Further, the kneaded product obtained by the above method can be produced by forming a thin film by roller pressurization or the like and then performing radiation crosslinking.

  When a linear resin is used as the binder, the weight ratio of the binder to the radiation crosslinking monomer is preferably 92.5: 7.5 to 97.5: 2.5. When the ratio of the radiation crosslinking monomer is larger than 7.5, the obtained thin film becomes a crosslinked body, the pulverization property is lowered, and the obtained image is also a low gloss image. On the other hand, if the ratio of the radiation crosslinking monomer is less than 2.5, uncrosslinked monomer remains, the grindability and storage stability deteriorate, and the offset property also decreases.

Since the kneaded material contains a colorant and the like, it has been found that sufficient cross-linking does not proceed in a lump state particularly in a black toner using carbon black. Therefore, it is necessary to reduce the film thickness in order to promote crosslinking.
The film thickness is not less than the average particle diameter of the toner and not more than 12 μm. If it is thicker than 12 μm, crosslinking does not proceed sufficiently. The average toner particle size is preferably 5 μm or more. When the average particle size of the toner is less than 5 μm, the transfer rate is lowered and background stains are likely to occur. Therefore, the film thickness is preferably 5 μm or more and 12 μm or less. The film thickness can be arbitrarily adjusted according to the pressurizing condition.
In addition, since the area that comes into contact with the outside air is increased by making the film thinner, it is necessary to perform in a nitrogen-substituted atmosphere during crosslinking. This is because it has been found that crosslinking is inhibited when exposed to oxygen.

It is important to adjust the film temperature during the crosslinking reaction. If the temperature at the time of crosslinking is too high, the radiation crosslinking monomer easily moves in the film, and the crosslinking reaction proceeds too much to form a large gel, resulting in a decrease in grindability and a decrease in glossiness of an image obtained as a toner image. When the temperature at the time of crosslinking is too low, the movement of the radiation crosslinking monomer is inhibited, crosslinking inhibition occurs, and uncrosslinked monomer remains. Residual monomers plasticize the binder resin, resulting in poor heat resistance, poor pulverization, and poor fixability.
A preferable crosslinking temperature is a glass transition point of the kneaded product + 5 ° C. or higher and a glass transition point + 30 ° C. or lower. When a crosslinking reaction is carried out at a preferred temperature, the radiation crosslinking monomer is present in the film as a linear polymer having a molecular weight of 100,000 to 1,000,000 suitable for the toner, or as a microgel.
The high molecular weight body functions as an additive for giving hot offset resistance.
However, when the resin containing the high molecular weight substance in the binder resin is kneaded, the molecular chain is broken during kneading and the manufactured product is likely to vary. The present invention makes it possible to create such a molecular weight distribution after kneading, which is significant in eliminating the above-described variations. In addition, the resin containing the high molecular weight body has the same composition as that of the low and middle molecular weight binder resin, and the viscosity during heating is increased overall (FIG. 7A). ), The high molecular weight obtained by the production method of the present invention is a high molecular weight polymer having a different composition from the binder resin in which the monomer is cross-linked, so that the viscosity on the low temperature side is increased as shown in FIG. Therefore, it is possible to maintain the viscosity at a high temperature.

In a system using a release agent, it is necessary that the temperature of the kneaded product after kneading is not higher than the melting point of the release agent and the glass transition point + 5 ° C. or more and the glass transition point + 30 ° C. or less are maintained. When the melting point of the mold release agent is exceeded, the mold release agent melts and recrystallizes to increase the dispersion diameter.
The dispersed particle diameter of the release agent is preferably 0.1 μm or more and 2.0 μm or less. If it is less than 0.1 μm, the release performance is deteriorated and hot offset or winding around the fixing member is likely to occur. If it is larger than 0.0 μm, the fluidity and charging characteristics of the obtained toner may be inferior.

Furthermore, after the cross-linked film is pulverized with a jet pulverizer, etc., it is spherically processed using a rotor pulverizer, etc., and a tendency to improve the quality is observed in fluidity and agglomeration. (See Japanese Patent No. 3478963)
The obtained pulverized product is appropriately classified into a target particle size distribution to produce a toner base of the toner of the present invention.

Hereinafter, an image forming apparatus using the toner for developing an electrostatic charge image of the present invention will be described in detail with reference to embodiments shown in the drawings.
FIG. 3 shows an example of an internal configuration diagram of a color image forming apparatus which is an embodiment of the electrophotographic image forming apparatus according to the present invention. This specific example is a tandem indirect transfer type electrophotographic copying apparatus, but the image forming apparatus of the present invention is applicable to all electrophotographic systems using a two-component developer, and is limited to this specific example. Not a thing. In the figure, reference numeral 100 denotes a copying apparatus main body, 200 a paper feed table on which the copying apparatus main body 100 is mounted, 300 a scanner (reading optical system) mounted on the copying apparatus main body 100, and 400 an automatic document feeder (ADF) mounted thereon. ). An endless belt-like intermediate transfer member 10 extending in the lateral direction is provided at the center position of the copying apparatus main body 100. In the illustrated example, the intermediate transfer member is wound around three support rollers 14, 15, and 16 so as to be able to rotate and convey clockwise in the drawing. In this illustrated example, an intermediate transfer body cleaning device 17 that removes residual toner remaining on the intermediate transfer body 10 after image transfer is provided to the left of the second support roller 15 among the three support rollers. Further, among the three support rollers, the intermediate transfer member 10 stretched between the first support roller 14 and the second support roller 15 has black, yellow, magenta, and cyan along the transport direction. The tandem image forming unit 20 is configured by arranging the four image forming units 18 side by side. An exposure device 21 is further provided immediately above the tandem image forming unit 20, as shown in FIG. On the other hand, a secondary transfer device 22 is provided on the opposite side of the intermediate transfer body 10 from the tandem image forming unit 20.

  In the illustrated example, the secondary transfer device 22 is configured by spanning a secondary transfer belt 24, which is an endless belt, between two rollers 23, and is pressed against the third support roller 16 via the intermediate transfer body 10. The image on the intermediate transfer body 10 is transferred to a sheet. A fixing device 25 for fixing the transfer image on the sheet is provided beside the secondary transfer device 22. The fixing device 25 is configured by pressing a pressure roller 27 against a fixing belt 26 that is an endless belt. The secondary transfer device 22 described above also has a sheet transport function for transporting the image-transferred sheet to the fixing device 25. In the illustrated example, a sheet reversing device 28 for reversing the sheet so as to record images on both sides of the sheet is provided below the secondary transfer device 22 and the fixing device 25 in parallel with the tandem image forming unit 20 described above. Is provided. Now, when making a copy using this color electrophotographic apparatus, a document is set on the document table 30 of the automatic document feeder 400. Alternatively, the automatic document feeder 400 is opened, a document is set on the contact glass 32 of the scanner 300, and the automatic document feeder 400 is closed and pressed by it. When a start switch (not shown) is pressed, when a document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32.

  On the other hand, when the document is set on the contact glass 32, the scanner 300 is immediately driven to travel on the first traveling body 33 and the second traveling body 34. Then, the first traveling body 33 emits light from the light source and further reflects the reflected light from the document surface toward the second traveling body 34, and is reflected by the mirror of the second traveling body 34 and passes through the imaging lens 35. The document is placed in the reading sensor 36 and the original content is read. When a start switch (not shown) is pressed, one of the support rollers 14, 15 and 16 is rotationally driven by a drive motor (not shown), and the other two support rollers are driven to rotate, so that the intermediate transfer body 10 is moved. Rotate and convey. At the same time, the individual image forming means 18 rotates the photoconductor 40 to form black, yellow, magenta, and cyan monochrome images on each photoconductor 40. Then, along with the conveyance of the intermediate transfer member 10, the single color images are sequentially transferred to form a composite color image on the intermediate transfer member 10.

  On the other hand, when a start switch (not shown) is pressed, one of the paper feed rollers 42 of the paper feed table 200 is selectively rotated, and the sheet is fed out from one of the paper feed cassettes 44 provided in multiple stages in the paper bank 43, and the separation roller 45. Then, the sheets are separated one by one into the paper feed path 46, transported by the transport roller 47, guided to the paper feed path 48 in the copying machine main body 100, and abutted against the registration roller 49 and stopped. Then, the registration roller 49 is rotated in synchronization with the composite color image on the intermediate transfer member 10, the sheet is fed between the intermediate transfer member 10 and the secondary transfer device 22, and transferred by the secondary transfer device 22. A color image is recorded on the sheet. The image-transferred sheet is conveyed by the secondary transfer device 22 and sent to the fixing device 25. The fixing device 25 applies heat and pressure to fix the transferred image. Are discharged and stacked on the discharge tray 57. Alternatively, it is switched by the switching claw 55 and put into the sheet reversing device 28, where it is reversed and guided again to the transfer position, and an image is recorded also on the back surface, and then discharged onto the discharge tray 57 by the discharge roller 56. On the other hand, the intermediate transfer body 10 after the image transfer is removed by the intermediate transfer body cleaning device 17 to remove residual toner remaining on the intermediate transfer body 10 after the image transfer, so that the tandem image forming unit 20 can prepare for another image formation.

  In the tandem image forming unit 20 described above, each image forming unit 18 includes a charging device 60, a developing device 61, a primary transfer device 62, and the like around the drum-shaped photoconductor 40. The photoconductor cleaning device 63 has at least a blade cleaning member. Further, as shown in FIG. 4, the developing device 61 includes a toner supply side stirring screw 66 as a developer stirring / conveying means, a developer carrying side stirring screw 67, a developer carrying body (developing roller). 68) A doctor blade 77 is provided. A supply port (not shown) is provided on the outer wall of the container of the first developer stirring chamber 86, and toner is supplied from a toner supply device (not shown). The agitation screw 66 on the toner replenishment side agitates and conveys the toner replenished from the toner replenishing device and the developer (two-component developer having magnetic particles and toner) in the developer container 65. Further, the stirring screw 67 in the second developer stirring chamber 87 (on the developer carrying member side) stirs and conveys the developer in the developer container 65. (Hereinafter, the second developer agitating chamber is referred to as a developing side agitating chamber.) The replenishing side agitating chamber and the developing side agitating chamber are partitioned by a partition plate 80 as shown in FIG. There is a passing opening. The developer in the developing side agitating chamber is pumped up by the developing sleeve, and the amount thereof is regulated by a doctor blade and supplied to the rubbing portion with the photosensitive member as a latent image carrier. At this time, the developer is given the greatest rubbing force by the doctor blade.

FIG. 6 shows a schematic configuration of a process cartridge using the electrostatic image developing toner of the present invention. In FIG. 6, reference numeral 210 denotes an entire process cartridge, 211 denotes a photosensitive member, 212 denotes a charging unit, 213 denotes a developing unit, and 214 denotes a cleaning unit.
In the present invention, a plurality of components such as the photosensitive member 211, the charging device unit 212, the developing unit 213, and the cleaning unit 214 described above are integrally combined as a process cartridge, and the process cartridge is copied. It is configured to be detachable from an image forming apparatus main body such as a printer or a printer.

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

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. Here, the part is based on weight.

[Example 1]
(Binder resin)
95 parts by weight of polyester copolymer (glass transition point 63.0 ° C., weight average molecular weight 15000)
(Release agent)
Paraffin wax (HNP-11 Nippon Seiki Co., Ltd., melting point 68.0 ° C.) 4.0 parts by weight (colorant)
P. B. 15: 3 (Toyo Ink Manufacturing Co., Ltd. KF7351) 3.7 parts by weight (radiation crosslinking monomer)
2.5 parts by weight of trimethylolpropane triacrylate (KAYARAD TMPTA manufactured by Nippon Kayaku Co., Ltd.)
2.5 parts by weight of neopentyl glycol diacrylate (KAYARAD NPGDA made by Nippon Kayaku Co., Ltd.)

  A kneaded product 1 was obtained by melt-kneading 30 kg of a mixture comprising the above components at the minimum kneadable temperature shown in Table 1 using a biaxial kneader. A part of the kneaded product 1 was sampled and the glass transition point of the kneaded product was measured. A film obtained by press-extending the kneaded material 1 with a pressure roller having a fluorine treatment on the surface so as to have a film thickness of 6 μm ± 1 μm at a temperature of 55 ° C. under a linear velocity of 10 m / min and 5 Mrad in a nitrogen atmosphere. The kneaded material 2 obtained by electron beam crosslinking at an oxygen concentration of 1% or less and then cooled is coarsely pulverized with a hammer mill and then finely pulverized to a mean particle size of 6.5 μm with a jet mill pulverizer. Surface treatment was performed using a turbo mill connected to a DS type airflow classifier, and fine powder classification was performed to obtain fine particles having a volume average particle diameter of 6.0 μm. To 100 parts of the fine particles, 1.5 parts by weight of H1303 (hydrophobized silica) and 0.8 parts by weight of MA150AI (hydrophobized titania) are mixed using a Henschel mixer, and a cyan electrostatic image developing toner A is mixed. Obtained. The external additives were mixed for imparting fluidity and adjusting charging characteristics.

[Example 2]
(Binder resin)
92.5 parts by weight of polyester copolymer (glass transition point 72.3 ° C., weight average molecular weight 15000)
(Release agent)
Paraffin wax (HNP-11 Nippon Seiki Co., Ltd., melting point 68.0 ° C.) 4.0 parts by weight (colorant)
Carbon black (Mitsui Chemicals) 8 parts by weight (radiation crosslinking monomer)
2.5 parts by weight of trimethylolpropane triacrylate (KAYARAD TMPTA manufactured by Nippon Kayaku Co., Ltd.)
Bisphenol A. EO adduct diacrylate 5.0 parts by weight (KAYARAD R-551, Nippon Kayaku Co., Ltd.)

  A kneaded product 1 was obtained by melt-kneading 30 kg of a mixture comprising the above components at the minimum kneadable temperature shown in Table 1 using a biaxial kneader. A part of the kneaded material 1 was sampled and the glass transition point of the kneaded material was measured. A film obtained by press-extending the kneaded material 1 with a pressure roller having a fluorine treatment on the surface so as to have a film thickness of 6 μm ± 1 μm at a temperature of 53 ° C. under a linear velocity of 10 m / min and 5 Mrad in a nitrogen atmosphere. The kneaded material 2 obtained by electron beam crosslinking at an oxygen concentration of 1% or less and then cooled is coarsely pulverized with a hammer mill and then finely pulverized to a mean particle size of 6.5 μm with a jet mill pulverizer. Surface treatment was performed using a turbo mill connected to a DS type airflow classifier, and fine powder classification was performed to obtain fine particles having a volume average particle diameter of 6.0 μm. To 100 parts of the fine particles, 1.5 parts by weight of H1303 (hydrophobized silica) and 0.8 parts by weight of MA150AI (hydrophobized titania) are mixed with a Henschel mixer to obtain toner B for developing a black electrostatic image. Obtained. The external additives were mixed for imparting fluidity and adjusting charging characteristics.

[Example 3]
(Binder resin)
97.5 parts by weight of polyester copolymer (glass transition point 58.0 ° C., weight average molecular weight 12000)
(Release agent)
Carnauba-Rice wax 6.0 parts by weight (WA-05 Celerica Noda, melting point 82.0 ° C)
(Coloring agent)
P. R. 122 and P.I. R. 269 (manufactured by DIC) 6 parts by weight (radiation crosslinking monomer)
Mixture of polyfunctional monomers 2.0 parts by weight (KAYARAD DPHA-2C Nippon Kayaku Co., Ltd.)
0.5 parts by weight of neopentyl glycol diacrylate (KAYARAD NPGDA manufactured by Nippon Kayaku Co., Ltd.)

  A kneaded product 1 was obtained by melt-kneading 30 kg of a mixture comprising the above components at the minimum kneadable temperature shown in Table 1 using a biaxial kneader. A part of the kneaded material 1 was sampled and the glass transition point of the kneaded material was measured. A film obtained by pressure-extending the kneaded material 1 with a pressure roller having a fluorine treatment on the surface so as to have a film thickness of 6 μm ± 1 μm at a temperature of 78 ° C. under a linear velocity of 10 m / min and 5 Mrad in a nitrogen atmosphere. The kneaded material 2 obtained by electron beam crosslinking at an oxygen concentration of 1% or less and then cooled is coarsely pulverized with a hammer mill and then finely pulverized to a mean particle size of 6.5 μm with a jet mill pulverizer. Surface treatment was performed using a turbo mill connected to a DS type airflow classifier, and fine powder classification was performed to obtain fine particles having a volume average particle diameter of 6.0 μm. To 100 parts of the fine particles, 1.5 parts by weight of H1303 (hydrophobized silica) and 0.8 parts by weight of MA150AI (hydrophobized titania) are mixed with a Henschel mixer to obtain a magenta electrostatic charge image developing toner C. Obtained. The external additives were mixed for imparting fluidity and adjusting charging characteristics.

[Example 4]
(Binder resin)
95 parts by weight of polyester copolymer (glass transition point 66.0 ° C., weight average molecular weight 29000)
(Release agent)
Ester wax (WEP-10, NOF Corp., melting point 68.0 ° C) 4.0 parts by weight (colorant)
P. Y. 74 (manufactured by DIC) 8 parts by weight (radiation crosslinking monomer)
2.5 parts by weight of trimethylolpropane triacrylate (KAYARAD TMPTA manufactured by Nippon Kayaku Co., Ltd.)
2.5 parts by weight of neopentyl glycol diacrylate (KAYARAD NPGDA made by Nippon Kayaku Co., Ltd.)

  A kneaded product 1 was obtained by melt-kneading 30 kg of a mixture comprising the above components at the minimum kneadable temperature shown in Table 1 using a biaxial kneader. A part of the kneaded material 1 was sampled and the glass transition point of the kneaded material was measured. A film obtained by press-extending the kneaded material 1 with a pressure roller having a fluorine treatment on the surface so as to have a film thickness of 6 μm ± 1 μm at a temperature of 55 ° C. under a linear velocity of 10 m / min and 5 Mrad in a nitrogen atmosphere. The kneaded material 2 obtained by electron beam crosslinking at an oxygen concentration of 1% or less and then cooled is coarsely pulverized with a hammer mill and then finely pulverized to a mean particle size of 6.5 μm with a jet mill pulverizer. Surface treatment was performed using a turbo mill connected to a DS type airflow classifier, and fine powder classification was performed to obtain fine particles having a volume average particle diameter of 6.0 μm. To 100 parts of the fine particles, 1.5 parts by weight of H1303 (hydrophobized silica) and 0.8 parts by weight of MA150AI (hydrophobized titania) are mixed with a Henschel mixer to obtain a yellow electrostatic charge image developing toner D. Obtained. The external additives were mixed for imparting fluidity and adjusting charging characteristics.

[Example 5]
(Binder resin)
95 parts by weight of polyester copolymer (glass transition point 63.0 ° C., weight average molecular weight 15000)
(Release agent)
Paraffin wax (HNP-11 manufactured by Nippon Seiki Co., Ltd., melting point 68.0 ° C.) 4.0 parts by weight (coloring agent)
P. B. 15: 3 (Toyo Ink Manufacturing Co., Ltd. KF7351) 3.7 parts by weight (radiation crosslinking monomer)
2.5 parts by weight of trimethylolpropane triacrylate (KAYARAD TMPTA manufactured by Nippon Kayaku Co., Ltd.)
2.5 parts by weight of neopentyl glycol diacrylate (KAYARAD NPGDA made by Nippon Kayaku Co., Ltd.)

  A kneaded product 1 was obtained by melt-kneading 30 kg of a mixture comprising the above components at the minimum kneadable temperature shown in Table 1 using a biaxial kneader. A part of the kneaded product 1 was sampled and the glass transition point of the kneaded product was measured. A film obtained by press-extending the kneaded product 1 with a pressure roller having a fluorine treatment on the surface so as to have a film thickness of 12 μm ± 1 μm at a temperature of 55 ° C. under a linear velocity of 10 m / min and 5 Mrad in a nitrogen atmosphere. The kneaded material 2 obtained by electron beam crosslinking at an oxygen concentration of 1% or less and then cooled is coarsely pulverized with a hammer mill and then finely pulverized to a mean particle size of 6.5 μm with a jet mill pulverizer. Surface treatment was performed using a turbo mill connected to a DS type airflow classifier, and fine powder classification was performed to obtain fine particles having a volume average particle diameter of 6.0 μm. To 100 parts of the fine particles, 1.5 parts by weight of H1303 (hydrophobized silica) and 0.8 parts by weight of MA150AI (hydrophobized titania) are mixed using a Henschel mixer, and a cyan electrostatic image developing toner E is added. Obtained. The external additives were mixed for imparting fluidity and adjusting charging characteristics.

[Example 6]
(Binder resin)
95 parts by weight of polyester copolymer (glass transition point 63.0 ° C., weight average molecular weight 15000)
(Release agent)
Paraffin wax (HNP-11 manufactured by Nippon Seiki Co., Ltd., melting point 68.0 ° C.) 4.0 parts by weight (coloring agent)
P. B. 15: 3 (Toyo Ink Manufacturing Co., Ltd. KF7351) 3.7 parts by weight (radiation crosslinking monomer)
2.5 parts by weight of trimethylolpropane triacrylate (KAYARAD TMPTA manufactured by Nippon Kayaku Co., Ltd.)
2.5 parts by weight of neopentyl glycol diacrylate (KAYARAD NPGDA made by Nippon Kayaku Co., Ltd.)

  Using a biaxial kneader, 30 kg of the mixture composed of the above components was obtained at the minimum kneadable temperature shown in Table 1 to obtain kneaded product 1. A part of the kneaded product 1 was sampled and the glass transition point of the kneaded product was measured. A film obtained by press-extending the kneaded material 1 with a pressure roller having a fluorine treatment on the surface so as to have a film thickness of 6 μm ± 1 μm at a temperature of 47 ° C. under a linear velocity of 10 m / min and 5 Mrad in a nitrogen atmosphere. The kneaded material 2 obtained by electron beam crosslinking at an oxygen concentration of 1% or less and then cooled is coarsely pulverized with a hammer mill and then finely pulverized to a mean particle size of 6.5 μm with a jet mill pulverizer. Surface treatment was performed using a turbo mill connected to a DS type airflow classifier, and fine powder classification was performed to obtain fine particles having a volume average particle diameter of 6.0 μm. With respect to 100 parts of the fine particles, 1.5 parts by weight of H1303 (hydrophobized silica) and 0.8 parts by weight of MA150AI (hydrophobized titania) are mixed with a Henschel mixer, and the toner F for cyan electrostatic image development is added. Obtained. The external additive was mixed for imparting fluidity and adjusting charging characteristics.

[Example 7]
(Binder resin)
95 parts by weight of polyester copolymer (glass transition point 63.0 ° C., weight average molecular weight 15000)
(Release agent)
Paraffin wax (HNP-11 manufactured by Nippon Seiki Co., Ltd., melting point 68.0 ° C.) 4.0 parts by weight (coloring agent)
P. B. 15: 3 (Toyo Ink Manufacturing Co., Ltd. KF7351) 3.7 parts by weight (radiation crosslinking monomer)
2.5 parts by weight of trimethylolpropane triacrylate (KAYARAD TMPTA manufactured by Nippon Kayaku Co., Ltd.)
2.5 parts by weight of neopentyl glycol diacrylate (KAYARAD NPGDA made by Nippon Kayaku Co., Ltd.)

  A kneaded product 1 was obtained by melt-kneading 30 kg of a mixture comprising the above components at the minimum kneadable temperature shown in Table 1 using a biaxial kneader. A part of the kneaded product 1 was sampled and the glass transition point of the kneaded product was measured. A film obtained by press-extending the kneaded material 1 with a pressure roller having a fluorine treatment on the surface so as to have a film thickness of 6 μm ± 1 μm at a temperature of 67 ° C. under a linear velocity of 10 m / min and 5 Mrad in a nitrogen atmosphere. The kneaded material 2 obtained by electron beam crosslinking at an oxygen concentration of 1% or less and then cooled is coarsely pulverized with a hammer mill and then finely pulverized to a mean particle size of 6.5 μm with a jet mill pulverizer. Surface treatment was performed using a turbo mill connected to a DS type airflow classifier, and fine powder classification was performed to obtain fine particles having a volume average particle diameter of 6.0 μm. To 100 parts of the fine particles, 1.5 parts by weight of H1303 (hydrophobized silica) and 0.8 parts by weight of MA150AI (hydrophobized titania) are mixed with a Henschel mixer, and a cyan electrostatic image developing toner G is added. Obtained. The external additive was mixed for imparting fluidity and adjusting charging characteristics.

[Comparative Example 1]
(Binder resin)
100 parts by weight of polyester copolymer (glass transition point 63.0 ° C., weight average molecular weight 15000)
(Release agent)
Paraffin wax (HNP-11 Nippon Seiki Co., Ltd., melting point 68.0 ° C.) 4.0 parts by weight (colorant)
P. B. 15: 3 (Toyo Ink Manufacturing Co., Ltd. KF7351) 3.7 parts by weight

  A kneaded product 1 was obtained by melt-kneading 30 kg of a mixture comprising the above components at the minimum kneadable temperature shown in Table 1 using a biaxial kneader. A part of the kneaded material 1 was sampled and the glass transition point of the kneaded material was measured. The kneaded product 1 is cooled, coarsely pulverized with a hammer mill, then finely pulverized with a jet mill pulverizer to an average particle size of 6.5 μm, and further surface-treated using a turbo mill connected to a DS type airflow classifier. And further finely classified to obtain fine particles having a volume average particle size of 6.0 μm. To 100 parts of the fine particles, 1.5 parts by weight of H1303 (hydrophobized silica) and 0.8 parts by weight of MA150AI (hydrophobized titania) are mixed with a Henschel mixer, and a toner H for developing a cyan electrostatic charge image is added. Obtained. The external additives were mixed for imparting fluidity and adjusting charging characteristics.

[Comparative Example 2]
(Binder resin)
Polyester copolymer 50 parts by weight (glass transition point 63.0 ° C., weight average molecular weight 15000)
Polyester copolymer 50 parts by weight (Glass transition point 63.0 ° C., weight average molecular weight 30000, gel component 5%)
(Release agent)
Paraffin wax (HNP-11 Nippon Seiki Co., Ltd., melting point 68.0 ° C.) 4.0 parts by weight (colorant)
P. B. 15: 3 (Toyo Ink Manufacturing KF7351) 3.7 parts by weight

  A kneaded product 1 was obtained by melt-kneading 30 kg of a mixture comprising the above components at the minimum kneadable temperature shown in Table 1 using a biaxial kneader. A part of the kneaded material 1 was sampled and the glass transition point of the kneaded material was measured. The kneaded product 1 is cooled, coarsely pulverized with a hammer mill, then finely pulverized with a jet mill pulverizer to an average particle size of 6.5 μm, and further surface-treated using a turbo mill connected to a DS type airflow classifier. And further finely classified to obtain fine particles having a volume average particle size of 6.0 μm. To 100 parts of the fine particles, 1.5 parts by weight of H1303 (hydrophobized silica) and 0.8 parts by weight of MA150AI (hydrophobized titania) are mixed with a Henschel mixer to obtain cyan electrostatic image developing toner I. Obtained. The external additives were mixed for imparting fluidity and adjusting charging characteristics.

[Comparative Example 3]
(Binder resin)
95 parts by weight of polyester copolymer (glass transition point 63.0 ° C., weight average molecular weight 15000)
(Release agent)
Paraffin wax (HNP-11 manufactured by Nippon Seiki Co., Ltd., melting point 68.0 ° C.) 4.0 parts by weight (coloring agent)
P. B. 15: 3 (Toyo Ink Manufacturing Co., Ltd. KF7351) 3.7 parts by weight (radiation crosslinking monomer)
2.5 parts by weight of trimethylolpropane triacrylate (KAYARAD TMPTA manufactured by Nippon Kayaku Co., Ltd.)
2.5 parts by weight of neopentyl glycol diacrylate (KAYARAD NPGDA made by Nippon Kayaku Co., Ltd.)

  Using a biaxial kneader, 30 kg of the mixture composed of the above components was obtained at the minimum kneadable temperature shown in Table 1 to obtain kneaded product 1. A part of the kneaded product 1 was sampled and the glass transition point of the kneaded product was measured. A film obtained by press-extending the kneaded material 1 with a pressure roller having a fluorine treatment on the surface so as to have a film thickness of 6 μm ± 1 μm at a temperature of 72 ° C. under a linear velocity of 10 m / min and 5 Mrad in a nitrogen atmosphere. The kneaded material 2 obtained by electron beam crosslinking at an oxygen concentration of 1% or less and then cooled is coarsely pulverized with a hammer mill and then finely pulverized to a mean particle size of 6.5 μm with a jet mill pulverizer. Surface treatment was performed using a turbo mill connected to a DS type airflow classifier, and fine powder classification was performed to obtain fine particles having a volume average particle diameter of 6.0 μm. With respect to 100 parts of the fine particles, 1.5 parts by weight of H1303 (hydrophobized silica) and 0.8 parts by weight of MA150AI (hydrophobized titania) are mixed with a Henschel mixer to prepare a toner J for developing a cyan electrostatic image. Obtained. The external additives were mixed for imparting fluidity and adjusting charging characteristics.

[Comparative Example 4]
(Binder resin)
95 parts by weight of polyester copolymer (glass transition point 63.0 ° C., weight average molecular weight 15000)
(Release agent)
Paraffin wax (HNP-11 manufactured by Nippon Seiki Co., Ltd., melting point 68.0 ° C.) 4.0 parts by weight (coloring agent)
P. B. 15: 3 (Toyo Ink Manufacturing Co., Ltd. KF7351) 3.7 parts by weight (radiation crosslinking monomer)
2.5 parts by weight of trimethylolpropane triacrylate (KAYARAD TMPTA manufactured by Nippon Kayaku Co., Ltd.)
2.5 parts by weight of neopentyl glycol diacrylate (KAYARAD NPGDA made by Nippon Kayaku Co., Ltd.)

Using a biaxial kneader, 30 kg of the mixture composed of the above components was obtained at the minimum kneadable temperature shown in Table 1 to obtain kneaded product 1. A part of the kneaded product 1 was sampled and the glass transition point of the kneaded product was measured. A film obtained by press-extending the kneaded product 1 with a pressure roller having a fluorine treatment on the surface so as to have a film thickness of 15 μm ± 1 μm at a temperature of 55 ° C. under a linear velocity of 10 m / min and 5 Mrad in a nitrogen atmosphere. The kneaded material 2 obtained by electron beam crosslinking at an oxygen concentration of 1% or less and then cooled is coarsely pulverized with a hammer mill and then finely pulverized to a mean particle size of 6.5 μm with a jet mill pulverizer. Surface treatment was performed using a turbo mill connected to a DS type airflow classifier, and fine powder classification was performed to obtain fine particles having a volume average particle diameter of 6.0 μm. However, a large amount occurred due to fusion to the wall of the pulverizer.
To 100 parts of the fine particles, 1.5 parts by weight of H1303 (hydrophobized silica) and 0.8 parts by weight of MA150AI (hydrophobized titania) are mixed with a Henschel mixer, and a cyan electrostatic image developing toner K is added. Obtained. The external additives were mixed for imparting fluidity and adjusting charging characteristics.

[Comparative Example 5]
(Binder resin)
95 parts by weight of polyester copolymer (glass transition point 63.0 ° C., weight average molecular weight 15000)
(Release agent)
Paraffin wax (HNP-11, Nippon Seiki Co., Ltd., melting point 68.0 ° C.) 4.0 parts by weight (colorant)
P. B. 15: 3 (Toyo Ink Manufacturing Co., Ltd. KF7351) 3.7 parts by weight (radiation crosslinking monomer)
2.5 parts by weight of trimethylolpropane triacrylate (KAYARAD TMPTA manufactured by Nippon Kayaku Co., Ltd.)
2.5 parts by weight of neopentyl glycol diacrylate (KAYARAD NPGDA made by Nippon Kayaku Co., Ltd.)

  Using a biaxial kneader, 30 kg of the mixture composed of the above components was obtained at the minimum kneadable temperature shown in Table 1 to obtain kneaded product 1. A part of the kneaded product 1 was sampled and the glass transition point of the kneaded product was measured. A film obtained by pressure-extending the kneaded material 1 with a pressure roller having a fluorine treatment on the surface so as to have a film thickness of 6 μm ± 1 μm at a temperature of 40 ° C. under a linear velocity of 10 m / min and 5 Mrad in a nitrogen atmosphere. The kneaded product 2 obtained by electron beam crosslinking at an oxygen concentration of 1% or less and then cooled was coarsely pulverized with a hammer mill and then pulverized with a jet mill pulverizer. could not.

  For all toners, sampling was performed after coarse pulverization, and the molecular weight of the binder resin was measured by gel permeation chromatography (GPC) using THF as a solvent. For toners A to G and K, a peak different from that of the binder resin was measured at a molecular weight of 50000 or more. Further, the toner L was not measured for components having a molecular weight of 50000 or more.

  Furthermore, when the residual monomer amount of the toner of the system to which the radiation crosslinking monomer was added was measured by gas chromatography, it was not detected from toners A to G, but residual monomers of 300 ppm or more were detected from toners K and L. .

Table 1 shows the melt-kneading lower limit temperature that gives the strongest shear, the yield after classification, the colorant dispersion diameter, and the release agent dispersion diameter.
The lower the kneading temperature, the more energy is saved. The higher the classification yield, the better the energy efficiency during production.
When the dispersion diameter of the colorant is larger than 400 nm, the image quality is deteriorated, and therefore, x, 400 nm or less is ◯, and 200 nm or less gives a high transparency image.
The release agent dispersion diameter was evaluated as “◯” when the average particle diameter was 0.1 μm or more and 2.0 μm or less, and when it was larger than 2.0 μm, the charging characteristics were affected.
Further, when a test was conducted on a system in which the release agent was removed from the formulation of the example, the same results were obtained as toner thermal properties and productivity. However, the fixing machine was a silicon oil coating machine, the maximum glossiness was 56, the upper limit fixing temperature was 200 ° C. or higher (not evaluated yet), and the high gloss temperature range was increased by 50 ° C. or more.

(Create developer)
The toner of the present invention is not limited to either a one-component developer or a two-component developer, but in this embodiment, the following carrier is used and mixed so that the toner: carrier is 7:93 and two-component development is performed. Evaluation was performed as agents A to J. Since toner K has low productivity, the characteristics of the two-component developer were not evaluated.
(Career)
Core material: Spherical ferrite particles with an average particle size of 35 μm Coating material: Mixture of silicone resin and melamine resin

Evaluation was performed as follows using a tandem color electrophotographic apparatus (“Imagio Neo C350”; manufactured by Ricoh Co., Ltd.).
The developer is introduced into the developing unit of the apparatus, the apparatus is adjusted so that a solid image with a toner adhesion amount of 0.8 mg / cm ² is obtained, and the fixing temperature is sequentially increased from 130 ° C. every 10 ° C. It was measured. At this time, the solid images of the respective toners were adjusted so as not to overlap each other, and the fixing temperature range was set to the upper limit temperature at a temperature where the glossiness value of the obtained image was 1% lower than the previous temperature condition.
Judgment is 130 ° C. fixability, fixing upper limit temperature 180 ° C. or higher, maximum glossiness 30 or higher, glossiness 30 or higher and temperature range 20 ° C. or higher are all passed ○, and one that does not satisfy even is rejected × .

The production method of the toner of the present invention has good production efficiency, and the obtained toner has excellent low-temperature fixability and offset property, and can obtain high gloss, so that electrophotography, electrostatic recording, It is suitable as a method for producing a toner for developing an electrostatic image used in an image forming method for developing an electrostatic latent image in electrostatic printing or the like.

It is a figure which shows the flow of the manufacturing method of the toner for electrostatic image development concerning this invention. It is a figure which shows the molecular weight distribution of the toner for electrostatic image development concerning this invention. 1 is a schematic configuration diagram illustrating an example of an electrophotographic image forming apparatus according to the present invention. 1 is a schematic configuration diagram illustrating an example of an image forming unit in an electrophotographic image forming apparatus according to the present invention. 1 is a schematic configuration diagram illustrating an example of a developing unit in an electrophotographic image forming apparatus according to the present invention. FIG. 3 is a schematic configuration diagram illustrating an example of a process cartridge according to the present invention. (A) is a figure which shows the relationship between the viscosity and temperature of resin by a conventional construction method, (b) is a figure which shows the relationship between the viscosity and temperature of resin containing a radiation crosslinked high molecular weight body.

Explanation of symbols

(About Figure 3)
DESCRIPTION OF SYMBOLS 14 Support roller 15 Support roller 16 Support roller 17 Intermediate transfer cleaning device 18 Image forming means 20 Charging roller 21 Exposure device 22 Secondary transfer device 23 Roller 24 Secondary transfer belt 25 Fixing device 26 Fixing belt 27 Pressure roller 28 Sheet reversing device DESCRIPTION OF SYMBOLS 30 Exposure apparatus 32 Contact glass 33 1st traveling body 34 2nd traveling body 35 Imaging lens 36 Reading sensor 40 Photosensitive body (photosensitive drum)
42 paper feed roller 43 paper bank 44 paper feed cassette 45 separation roller 46 paper feed path 47 transport roller 48 paper feed path 50 intermediate transfer member 51 roller 52 separation roller 53 constant current source 55 switching claw 56 discharge roller 57 discharge tray 100 image formation Device 150 Copier Main Body 300 Scanner 400 Automatic Document Feeder (ADF)
(About FIGS. 4-6)
40 Image carrier (photoconductor)
68 Developing sleeve 75 Toner concentration sensor 77 Doctor blade 78 Developer path regulating member 80 Partition plate 86 Supply side stirring chamber 87 Development side stirring chamber 210 Process cartridge 211 Photoconductor 212 Charging means 213 Developing means 214 Cleaning means

Claims (9)

At least a step of heating and kneading the binder resin, a radiation crosslinking monomer compatible with the binder resin, and a colorant;
A step of thinning the kneaded product obtained by the kneading so as to have a film thickness of not less than the average particle diameter of the target toner and not more than 12 μm;
A step of crosslinking the radiation-crosslinking monomer by irradiating the thin film obtained by the thinning with radiation at a glass transition point of the kneaded product of + 5 ° C. or higher and + 30 ° C. or lower;
Crushing and classifying the thin film after radiation irradiation to obtain toner particles;
A method for producing a toner for developing an electrostatic charge image, comprising: At least a binder resin, a radiation crosslinking monomer that is compatible with the binder resin, a colorant, and a release agent, which are heated and melt-kneaded below the melting point of the release agent;
A step of thinning the kneaded product obtained by the kneading so as to have a film thickness of not less than the average particle diameter of the target toner and not more than 12 μm;
A step of crosslinking the radiation crosslinking monomer by irradiating the thin film obtained by the thinning with radiation at a temperature not higher than the melting point of the release agent and not lower than the glass transition point of the kneaded material + 5 ° C. + 30 ° C .;
Crushing and classifying the thin film after radiation irradiation to obtain toner particles;
A method for producing a toner for developing an electrostatic charge image, comprising: 3. The method for producing a toner for developing an electrostatic charge image according to claim 1, wherein the release agent does not dissolve in the radiation crosslinking monomer and has a melting point of 60 ° C. or more and 100 ° C. or less.   A toner for developing an electrostatic charge image, comprising at least a binder resin and a colorant, obtained by the production method according to claim 1.   5. The electrostatic image developing toner according to claim 4, wherein the binder resin has a high molecular weight polymer having a molecular weight of 50000 or more obtained by radiation-crosslinking a linear resin not containing a gel component and a radiation-crosslinking monomer. .   6. The toner for developing an electrostatic charge image according to claim 4, wherein the linear resin is a polyester resin.   The electrostatic charge image according to claim 4, wherein a weight ratio of the linear resin and the radiation crosslinking monomer is 92.5: 7.5 to 97.5: 2.5. Development toner.   An electrophotographic image forming apparatus using the electrostatic image developing toner according to claim 4.   A process cartridge comprising the electrostatic image developing toner according to claim 4.

Images