JP2007233021A - Electrostatic image developing yellow toner and its manufacturing method, electrostatic image developer, and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatic image developing yellow toner for reproducing stabilized and excellent color images. <P>SOLUTION: This electrostatic image developing yellow toner contains a binder resin and a yellow-based coloring agent and can reproduce stabilized and excellent color images by further containing abietic acid and a surfactant of a four or smaller HLB in a predetermined amount. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a yellow toner for developing an electrostatic image used for developing an electrostatic image formed by electrophotography, electrostatic recording method or the like, a manufacturing method thereof, an electrostatic image developer, and an image forming method.

  A method of visualizing image information through an electrostatic charge image such as electrophotography is currently used in various fields. In electrophotography, an electrostatic latent image is formed on a photoreceptor by charging and exposure processes, and the electrostatic latent image is developed with a developer containing an electrostatic charge image developing toner (hereinafter may be abbreviated as “toner”). Then, an electrostatic charge image is visualized through a transfer and fixing process.

  In the electrophotographic method, when a full-color image is formed, color reproduction is performed using four colors of yellow, magenta, cyan, and black toner, which are three primary colors. The color toner used has various characteristics such as good charging characteristics, low environmental dependency, little toner deterioration due to long-term continuous use, and good low-temperature fixing characteristics. Is required. In particular, what is important in using a color toner is that it has stable color reproducibility and excellent color development and color. However, there are limitations on the coloring materials that can be used under the condition that the color reproducibility, color developability, and colorability can be satisfied in a good state, and charging that is important in achieving the electrophotographic technology. In selecting a material that also has characteristics and durability stability, there are more restrictions in a narrower range. In particular, in the case of forming a full-color image, there are many demands for improving the toner characteristics.

  In order to develop a secondary color, for example, green, with a color toner, the cyan toner and the yellow toner are superimposed at a predetermined ratio according to the color density, and the color is developed. If it is low, the color reproducibility is inferior, and if the dispersion stability of the yellow pigment or the like during long-term storage is poor, stable and good color reproducibility cannot be ensured.

  As a proposal for improving color reproducibility, for example, Patent Document 1 aims to improve dispersibility of pigments in toner. I. A combination of Pigment Yellow 74 and a toner manufacturing method has been proposed. Further, for example, in Patent Document 2, C.I. I. Pigment yellow 185 and C.I. I. Pigment yellow 74, or C.I. I. Pigment yellow 185 and C.I. I. It has been proposed to use mixed pigments in combination with Pigment Yellow 154.

JP 2004-85997 A JP 2005-17838 A

  However, the method of Patent Document 1 is inferior in versatility because the types of pigments are limited. Further, in the method of Patent Document 2, it is difficult to control the degree of pigment mixing, and it is difficult to stably achieve good color reproducibility.

  The present invention relates to a yellow toner for developing an electrostatic image having stable and good color reproducibility, a method for producing a yellow toner for developing an electrostatic image, an electrostatic image developer, and an image forming method.

  The present invention includes a binder resin, a yellow colorant, abietic acid, and a surfactant having an HLB value of 4 or less, and the content of the abietic acid in the toner is 0.2 to 1. This is a yellow toner for developing electrostatic images having 2% by weight and a surfactant content of 0.04 to 1.0% by weight.

  The present invention also includes a step of mixing and dispersing a yellow colorant, abietic acid and a surfactant having an HLB value of 4 or less to obtain a colorant composition; and the colorant composition in an aqueous solvent. The step of dispersing to obtain a colorant dispersion, and the resin particles, the colorant and the release agent in a dispersion obtained by mixing and dispersing the resin particle dispersion, the release agent dispersion and the colorant dispersion. A method for producing an electrostatic charge image developer yellow toner comprising a step of aggregating to form aggregated particles and a step of heating to fuse the aggregated particles.

  Further, the present invention is an electrostatic charge image developer comprising the yellow toner for developing an electrostatic charge image and a carrier coated with a resin containing a crystalline polyester resin and an amorphous resin.

  Furthermore, the present invention uses a latent image forming step for forming an electrostatic latent image on the surface of the latent image holding member and a developer carried on the developer carrying member, and the electrostatic image formed on the surface of the latent image holding member. A developing step of developing a latent image to form a toner image, a transferring step of transferring the toner image formed on the surface of the latent image holding member to the surface of the transfer target, and a toner image transferred to the surface of the transfer target A fixing step of fixing the toner, wherein the developer is the electrostatic charge image developer.

  In the present invention, in a yellow toner for developing an electrostatic image containing a binder resin and a yellow colorant, by containing a predetermined amount of abietic acid and a surfactant having an HLB value of 4 or less, It can have good color reproducibility.

  In the present invention, a colorant composition obtained by mixing and dispersing a yellow colorant, abietic acid, and a surfactant having an HLB value of 4 or less is dispersed in an aqueous solvent to obtain a colorant dispersion. Produces and mixes the colorant dispersion, resin particle dispersion, and release agent dispersion, and agglomerates and fuses to produce a yellow toner for developing electrostatic images having stable and good color reproducibility. can do.

  Embodiments of the present invention will be described below.

<Yellow toner for electrostatic image development>
The yellow toner for developing an electrostatic charge image according to the exemplary embodiment contains a binder resin, a yellow colorant, abietic acid, and a surfactant having an HLB value of 4 or less. The HLB (Hydrophyl Lipophile Balance) value is a value representing the degree of affinity of the surfactant to water and oil (water-insoluble organic compound). The HLB value takes a value from 0 to 20, and the closer to 0, the higher the lipophilicity and the closer to 20, the higher the hydrophilicity. In the present embodiment, the HLB value of the surfactant is 4 or less, preferably 3 or less, and more preferably 2.5 or more. When the HLB value of the surfactant exceeds 4, the surfactant dissolves in the water from the colorant such as pigment when dispersed in the aqueous solvent, the surfactant in the colorant decreases, and the colorants aggregate together. When generated, the colorant dispersibility deteriorates. Moreover, when the HLB value is less than 2.5, the lipophilicity of the surfactant is high, the colorant and the surfactant do not adhere, and the dispersibility may not be effective.

  Examples of the surfactant having an HLB value of 4 or less include glycerin fatty acid ester, tetraglycerin pentaester, octylphenol ethoxylate and the like. From the viewpoint of versatility, tetraglycerin pentaester and octylphenol ethoxylate are preferable, and octylphenol is preferred. More preferred is ethoxylate.

  In the present embodiment, the HLB value of the surfactant is the Atlas method (for ester surfactants, the saponification value is S, the acid value of the fatty acid constituting the surfactant is A, and the HLB value = 20 (1-S / A).

  The content of the surfactant in the toner is in the range of 0.04 to 1.0% by weight, and preferably in the range of 0.2 to 0.5% by weight. When the content of the surfactant in the toner is less than 0.04% by weight, the effect as a surfactant is lowered, the dispersibility of a colorant such as a pigment is lowered, and the color reproducibility is lowered. If it exceeds 1.0% by weight, the surfactant becomes excessive, the powder fluidity of the toner is lowered, and the color reproducibility is also lowered.

  Examples of abietic acid include abietic acid ester in addition to abietic acid itself. Abietic acid having a surface active property is excellent in terms of dispersibility of the colorant.

  The content of abietic acid in the toner is in the range of 0.2 to 1.2% by weight, and preferably in the range of 0.4 to 0.7% by weight. When the content of abietic acid in the toner is less than 0.2% by weight, the surfactant action with respect to the colorant is insufficient and the dispersibility of the colorant is lowered, and when the content exceeds 1.2% by weight. When the amount of abietic acid in the toner is increased, the amount of resin and colorant is decreased, the image density is decreased, the viscosity of the toner is further decreased, and the peelability is deteriorated.

  The content of the surfactant and abietic acid in the toner means the content in the toner after the addition of the external additive, and can be determined by a method using a high performance liquid chromatography apparatus (manufactured by Shimadzu Corporation, LC6A type). . Specifically, the surfactant and abietic acid peaks, and the resin and surfactant and resin and abietic acid mixture peaks were measured by high performance liquid chromatography, and the respective surfactant and abietic acid calibration curves were obtained. Create The toner is measured based on the calibration curve, and the surfactant content and abietic acid content are determined.

  Examples of yellow colorants include insoluble azo pigments such as condensed azo pigments and azo chelate pigments in addition to monoazo yellow, disazo yellow, and benzimidazolone pigments. Moreover, dyes, such as a synthetic dye and a vegetable dye, are also mentioned. Specifically, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 180, C.I. I. Pigment Yellow 93 and the like, and C.I. I. Pigment Yellow 74 is preferable. As the yellow colorant, one or two or more of the above pigments and dyes can be used in combination.

  The content of the yellow colorant in the toner is in the range of 3.0 to 8.0% by weight, and preferably in the range of 4.0 to 6.0% by weight. If the content of the yellow colorant in the toner is less than 3.0% by weight, the image density may be lowered and a desired density may not be obtained. If the content exceeds 8.0% by weight, the saturation may be reduced. The color reproducibility may not be obtained.

  The yellow toner for developing an electrostatic charge image according to the exemplary embodiment contains abietic acid and a surfactant having an HLB value of 4 or less, that is, a surfactant that is hardly soluble in water. In addition, since it is covered with a surfactant that is hardly soluble in water, the yellow pigment has good dispersibility in yellow toner, so that color reproducibility is excellent, and the dispersion stability of yellow pigment is also good during long-term storage. Therefore, stable and good color reproducibility can be realized without reaggregation. Further, since the periphery of the pigment is covered with a surfactant that is hardly soluble in abietic acid and water, the light resistance of the yellow pigment, which is slightly inferior to cyan and magenta, can be improved. In particular, C.I. having an azo group as a functional group. I. The light resistance of Pigment Yellow 74 can be improved.

(Binder resin)
The binder resin used in the yellow toner for developing electrostatic images according to this embodiment includes at least one of a crystalline resin and an amorphous resin, but preferably includes a crystalline resin and an amorphous resin. When a crystalline resin is not included, it may be difficult to achieve both low-temperature fixing and blocking resistance. Further, a crystalline resin and an amorphous resin may be used as the core particles, and the shell layer may be formed by coating with the amorphous resin.

  In the present embodiment, “crystallinity” of “crystalline resin” refers to having a clear endothermic peak rather than a stepwise endothermic amount change in differential scanning calorimetry (DSC) of the resin or toner. Specifically, in differential scanning calorimetry (DSC) using a differential scanning calorimeter (equipment name: DSC-60 type) manufactured by Shimadzu Corporation equipped with an automatic tangential processing system, a rate of temperature increase of 10 ° C./min. A “clear” endothermic peak is assumed when the temperature from the onset point to the top of the endothermic peak when the temperature is raised at 10 ° C. is within 10 ° C. Further, from the viewpoint of sharp melt, the temperature from the onset point to the peak top of the endothermic peak is preferably within 10 ° C, and more preferably within 6 ° C. Specify any point on the flat part of the baseline in the DSC curve and any point on the flat part of the falling part from the baseline, and the intersection of the tangents of the flat part between the two points is automatically set as the “onset point”. Obtained automatically by the tangent processing system. Further, the endothermic peak may show a peak having a width of 40 to 50 ° C. when the toner is used.

  “Non-crystalline resin” means that when the temperature from the onset point to the peak top of the endothermic peak exceeds 10 ° C. in the differential scanning calorimetry (DSC) of the resin or toner, or a clear endothermic peak is observed. It refers to a resin that cannot be used. Specifically, in differential scanning calorimetry (DSC) using a differential scanning calorimeter (equipment name: DSC-60 type) manufactured by Shimadzu Corporation equipped with an automatic tangential processing system, a rate of temperature increase of 10 ° C./min. When the temperature from the onset point to the peak top of the endothermic peak when the temperature is raised at 10 ° C exceeds 10 ° C., or when no clear endothermic peak is observed, it is assumed to be “non-crystalline”. Further, the temperature from the onset point to the peak top of the endothermic peak preferably exceeds 12 ° C., and more preferably no clear endothermic peak is observed. The method for obtaining the “onset point” in the DSC curve is the same as in the case of the “crystalline resin”.

  In the toner according to the exemplary embodiment, when the binder resin includes a crystalline resin and an amorphous resin, the content of the crystalline resin contained in the toner is preferably in the range of 20 to 95% by weight. More preferably, it is in the range of 25 to 65% by weight. When the content of the crystalline resin is 20% by weight or less, low temperature fixing may be difficult due to an increase in the melting point of the toner. Furthermore, the document offset property of an image obtained using such toner may be deteriorated. Also, by controlling the melting characteristics of the crystalline resin contained in the toner by the resin acid value and the metal salt, it is hardly affected by the melting characteristics of the non-crystalline resin existing on the outermost surface under the thin film conditions. It is possible to control the melting characteristics of the toner.

In this embodiment, when a crystalline resin and an amorphous resin are used as the toner core particles, it is preferable that they are compatible with each other. The SP value (solubility parameter: Solubility Parameter, here) of both resins is used as the standard. Then, it is preferable that the difference between the values obtained by the Fedors method and using “a value obtained by omitting“ × 10 ⁻³ J ^1/2 m ^−3/2 ”” is within one.

(Crystalline resin)
The crystalline resin is not particularly limited as long as it is a crystalline resin, and specific examples include crystalline polyester resins and crystalline vinyl resins. From the viewpoint of adjusting the melting point within a preferable range, a crystalline polyester resin is preferable. An aliphatic crystalline polyester resin having an appropriate melting point is more preferable.

  Further, the “crystalline polyester resin” used in the toner according to the exemplary embodiment is obtained by polymerizing a component constituting polyester and other components in addition to a polymer having a 100% polyester structure as a constituent component. It also means a polymer (copolymer). However, in the latter case, the component other than the polyester constituting the polymer (copolymer) is 50% by weight or less.

  Examples of the crystalline vinyl resin include amyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, and decyl (meth) acrylate. , Undecyl (meth) acrylate, tridecyl (meth) acrylate, myristyl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, oleyl (meth) acrylate, behenyl (meth) acrylate, etc. And vinyl resins using long-chain alkyl and alkenyl (meth) acrylic acid esters. In this specification, the description “(meth) acryl” means that both “acryl” and “methacryl” are included.

  The crystalline polyester resin and all other polyester resins used in the toner according to this embodiment are synthesized from a polyvalent carboxylic acid component and a polyhydric alcohol component. In addition, in this embodiment, a commercial item may be used as said polyester resin, and what was synthesize | combined suitably may be used.

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

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

  Moreover, as an acid component, it is preferable that the dicarboxylic acid component which has a sulfonic acid group other than the above-mentioned aliphatic dicarboxylic acid and aromatic dicarboxylic acid is contained. The dicarboxylic acid having a sulfonic acid group is effective in that it can favorably disperse a coloring material such as a pigment. Further, when the entire resin is emulsified or suspended in water to form fine particles, if there are sulfonic acid groups, as described later, emulsification or suspension can be performed without using a surfactant.

  Examples of the dicarboxylic acid having a sulfone group include, but are not limited to, 2-sulfoterephthalic acid sodium salt, 5-sulfoisophthalic acid sodium salt, and sulfosuccinic acid sodium salt. Moreover, these lower alkyl esters, acid anhydrides, etc. are also mentioned. The divalent or higher carboxylic acid component having a sulfonic acid group is contained in an amount of 1 to 15 mol%, preferably 2 to 10 mol%, based on all carboxylic acid components constituting the polyester. When the content is low, the stability of the emulsified particles with time deteriorates. On the other hand, when the content exceeds 15 mol%, not only the crystallinity of the polyester resin is deteriorated but also the process of coalescing the particles after aggregation is adversely affected. There is a problem that it becomes difficult to adjust.

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

  As the polyhydric alcohol component, an aliphatic diol is preferable, and a linear aliphatic diol having 7 to 20 carbon atoms in the main chain portion is more preferable. When the aliphatic diol is branched, the crystallinity of the polyester resin is lowered and the melting point is lowered, so that toner blocking resistance, image storage stability, and low-temperature fixability may be deteriorated. Further, when the number of carbon atoms is less than 7, when the polycondensation with aromatic dicarboxylic acid is performed, the melting point becomes high and fixing at low temperature may be difficult. On the other hand, when the number exceeds 20, it is difficult to obtain practical materials. easy. The carbon number is more preferably 14 or less.

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

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

  Among the polyhydric alcohol components, the content of the aliphatic diol component is preferably 80 mol% or more, and more preferably 90% or more. If the content of the aliphatic diol component is less than 80 mol%, the crystallinity of the polyester resin is lowered and the melting point is lowered, so that toner blocking resistance, image storage stability, and low-temperature fixability may be deteriorated. is there.

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

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

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

[Amorphous resin]
Examples of the non-crystalline resin used in the toner according to the exemplary embodiment include conventionally known thermoplastic binder resins, and specific examples include styrenes such as styrene, parachlorostyrene, and α-methylstyrene. Homopolymer or copolymer (styrene resin) of methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, methacrylic acid Homopolymers or copolymers of vinyl-containing esters such as ethyl, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc .; vinyl nitriles such as acrylonitrile and methacrylonitrile Homopolymer or copolymer (vinyl resin); vinyl methyl ether Homopolymers or copolymers of vinyl ethers such as vinyl isobutyl ether (vinyl resins); Homopolymers or copolymers of vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone (vinyl resins) ; Homopolymers or copolymers of olefins such as ethylene, propylene, butadiene, and isoprene (olefin-based resins); Non-vinyl condensation systems such as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, and polyether resins And a graft polymer of these non-vinyl condensation resins and vinyl monomers. These resins may be used alone or in combination of two or more. Among these resins, vinyl resins and polyester resins are particularly preferable.

  In the case of a vinyl resin, it is advantageous in that a resin particle dispersion can be easily prepared by emulsion polymerization or seed polymerization using an ionic surfactant or the like. Examples of the vinyl monomers include vinyl polymer acids and vinyl polymer bases such as acrylic acid, methacrylic acid, maleic acid, cinnamic acid, fumaric acid, vinyl sulfonic acid, ethyleneimine, vinylpyridine, and vinylamine. Examples include monomers as raw materials.

  In this embodiment, it is preferable that the resin particles contain the vinyl monomer as a monomer component. Among these vinyl monomers, vinyl polymer acids are more preferable from the viewpoint of ease of formation reaction of vinyl resins, and specifically, acrylic acid, methacrylic acid, maleic acid, cinnamic acid, fumaric acid, etc. A dissociable vinyl monomer having a carboxyl group as a dissociating group is particularly preferred from the viewpoint of controlling the degree of polymerization and the glass transition point.

  The concentration of the dissociating group in the dissociable vinyl monomer is determined by dissolving particles such as toner particles from the surface, as described in, for example, polymer latex chemistry (Polymer Publications). Etc. can be determined. It should be noted that the molecular weight of the resin and the glass transition point from the surface of the particle to the inside can also be determined by the above method or the like.

  In the toner according to the exemplary embodiment, when a polyester resin is used as the non-crystalline resin, the resin particle dispersion can be easily prepared by emulsifying and dispersing the resin by adjusting the acid value of the resin or using an ionic surfactant. It is advantageous in that it can be prepared. The amorphous polyester resin used for emulsification dispersion is synthesized by dehydration condensation of a polyvalent carboxylic acid and a polyhydric alcohol.

  Examples of polyvalent carboxylic acids include aromatic carboxylic acids such as terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, pyromellitic acid, naphthalenedicarboxylic acid, maleic anhydride, fumaric acid, succinic acid, alkenyl. Examples thereof include aliphatic carboxylic acids such as succinic anhydride and adipic acid, and alicyclic carboxylic acids such as cyclohexanedicarboxylic acid. These polyvalent carboxylic acids can be used alone or in combination. Of these polyvalent carboxylic acids, it is preferable to use aromatic carboxylic acids, and in order to take a crosslinked structure or a branched structure in order to ensure good fixability, tricarboxylic or higher carboxylic acids (trimerits) It is preferable to use an acid or an acid anhydride thereof in combination.

  Examples of polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, glycerin, and other aliphatic diols, cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol A And aromatic diols such as bisphenol A ethylene oxide adduct and bisphenol A propylene oxide adduct.

  One or more of these polyhydric alcohols can be used. Among these polyhydric alcohols, aromatic diols and alicyclic diols are preferable, and among these, aromatic diols are more preferable. In order to secure good fixing properties, a trihydric or higher polyhydric alcohol (glycerin, trimethylolpropane, pentaerythritol) may be used in combination with the diol in order to take a crosslinked structure or a branched structure.

  In addition, monocarboxylic acid and / or monoalcohol is further added to the polyester resin obtained by polycondensation of polycarboxylic acid and polyhydric alcohol to esterify the hydroxyl group and / or carboxyl group at the polymerization terminal. The acid value of the polyester resin may be adjusted. Examples of the monocarboxylic acid include acetic acid, acetic anhydride, benzoic acid, trichloroacetic acid, trifluoroacetic acid, propionic anhydride and the like, and examples of the monoalcohol include methanol, ethanol, propanol, octanol, 2-ethylhexanol, and trifluoroethanol. , Trichloroethanol, hexafluoroisopropanol, phenol and the like.

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

  Examples of the catalyst used for the synthesis of this polyester resin include esterification catalysts such as organic metals such as dibutyltin dilaurate and dibutyltin oxide, and metal alkoxides such as tetrabutyl titanate. The amount of such a catalyst added is preferably 0.01 to 1% by weight based on the total amount of raw materials. The catalyst used here becomes a factor in coloring the binder resin.

  The amorphous resin used in the toner according to the exemplary embodiment has a weight average molecular weight (Mw) of 5,000 to 1,000,000 as measured by a gel permeation chromatography (GPC) method of a soluble content of tetrahydrofuran (THF). More preferably, it is 7000-500000, the number average molecular weight (Mn) is preferably 2000-100000, the molecular weight distribution Mw / Mn is preferably 1.5-100, more preferably 2-2. 60.

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

  The molecular weight of the resin was measured with a THF solvent using a Toso GPC / HLC-8120, Tosoh column TSKgel SuperHM-M (15 cm), and a molecular weight calibration prepared with a monodisperse polystyrene standard sample. The molecular weight was calculated using a curve.

  The acid value of the polyester resin (the number of mg of KOH required to neutralize 1 g of resin) is easy to obtain the molecular weight distribution as described above, and is easy to ensure the granulation property of the toner particles by the emulsion dispersion method. From the standpoint of easy maintenance of the environmental stability (chargeability stability when the temperature and humidity are changed) of the obtained toner, it is preferably 1 to 30 mgKOH / g. The acid value of the polyester resin can be adjusted by controlling the carboxyl group at the terminal of the polyester according to the blending ratio of the raw polyhydric carboxylic acid and polyhydric alcohol and the reaction rate. Or what has a carboxyl group in the principal chain of polyester is obtained by using trimellitic anhydride as a polyvalent carboxylic acid component.

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

  The component constituting the toner in the exemplary embodiment is not particularly limited as long as it contains at least a binder resin and a colorant as described above, but other components such as a release agent may be added as necessary. May be included.

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

  The melting point of the release agent is preferably 50 ° C. or higher, more preferably 60 ° C. or higher, from the viewpoint of storage stability. Moreover, it is preferable that it is 110 degrees C or less from a viewpoint of offset resistance, and it is more preferable that it is 100 degrees C or less. The melting point of the release agent can be determined by the same method as the melting point of the following toner.

  The content of the release agent is preferably in the range of 1 to 30 parts by weight and more preferably in the range of 2 to 20 parts by weight with respect to 100 parts by weight of the binder resin. When the content of the release agent is less than 1 part by weight, there is no effect of adding the release agent, and hot offset at a high temperature may be caused. On the other hand, when the amount exceeds 30 parts by weight, the charging property is adversely affected, and the mechanical strength of the toner is reduced. Therefore, the toner is easily destroyed by stress in the developing machine, and may cause carrier contamination. Further, when used as a color toner, a domain tends to remain in a fixed image, which may cause a problem that OHP transparency is deteriorated.

(Rosin)
Rosin is used for the toner according to the exemplary embodiment. Commonly called rosin, it is a mixture of abietic acid, neoabietic acid, dihydroabietic acid, dehydroabietic acid, pimaric acid, isopimaric acid, levopimaric acid, parastriic acid, etc., among which the ratio of abietic acid is generally Is 20 to 45% by weight. In Examples described later, rosin was added and the amount of abietic acid was measured.

(Other additives)
In addition to the components described above, various components such as an internal additive, a charge control agent, inorganic powder (inorganic particles), and organic particles may be added to the toner according to the exemplary embodiment as necessary. Can do.

  Examples of the internal additive include metals such as ferrite, magnetite, reduced iron, cobalt, nickel, and manganese, alloys, and magnetic materials such as compounds containing these metals.

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

  The inorganic powder is added mainly for the purpose of adjusting the viscoelasticity of the toner. For example, silica, alumina, titania, calcium carbonate, magnesium carbonate, calcium phosphate, cerium oxide, etc. Examples thereof include all inorganic fine particles used as an external additive on the toner surface.

  Examples of inorganic particles and organic particles externally added to the toner surface include the following.

  Examples of inorganic particles include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, cerium chloride, Examples include Bengala, chromium oxide, cerium oxide, antimony trioxide, magnesium oxide, zirconium oxide, silicon carbide, and silicon nitride. Among these, silica particles and titanium oxide particles are preferable, and hydrophobically treated particles are particularly preferable.

  Inorganic particles are generally used for the purpose of improving fluidity. The volume average particle diameter of the inorganic particles is preferably 1 to 200 nm, and the addition amount is preferably 0.01 to 20 parts by weight with respect to 100 parts by weight of the toner.

  Organic particles are generally used for the purpose of improving cleaning properties and transfer properties, and specific examples include polystyrene, polymethyl methacrylate, polyvinylidene fluoride, and the like.

(Physical properties of toner for developing electrostatic image)
The volume average particle diameter D50v of the electrostatic image developing toner according to this embodiment is preferably in the range of 4 μm to 8 μm. If the volume average particle diameter D50v of the toner is smaller than 4 μm, the charging property will be insufficient and scattering to the surroundings will cause image fogging, or the toner that could not be transferred will not be sufficiently cleaned and filming will occur. It is not preferable because it causes it. On the other hand, when the volume average particle diameter D50v exceeds 8 μm, the resolution of the image is lowered and it tends to be difficult to achieve high image quality.

  The volume average particle size distribution index GSDv of the electrostatic image developing toner according to this embodiment is 1.27 or less, preferably 1.25 or less. When GSDv exceeds 1.27, the particle size distribution is not sharp, resolution is deteriorated, and image defects such as toner scattering and fogging are caused.

The volume average particle diameter D50v and the volume average particle size distribution index GSDv can be obtained by measuring with an aperture diameter of 100 μm using a Coulter Multisizer II type (manufactured by Beckman-Coulter). At this time, the measurement is performed after the toner is dispersed in an electrolyte aqueous solution (isoton aqueous solution) and dispersed by ultrasonic waves for 30 seconds or more. Accumulate the volume and number from the smaller diameter side by drawing the cumulative distribution from the smaller particle size range (channel) divided based on the particle size distribution of the toner measured with Coulter Multisizer II (manufactured by Beckman-Coulter) The particle diameter that is 16% is defined as volume D16v and a number D16p, the particle diameter that is accumulated 50% is defined as volume D50v and a number D50p, and the particle diameter that is accumulated 84% is defined as volume D84v and number D84p. At this time, D50v represents the volume average particle diameter, and the volume average particle size distribution index (GSDv) is determined as (D84v / D16v) ^1/2 . In addition, (D84p / D16p) ^1/2 represents a number average particle size distribution index (GSDp).

In addition, the shape factor SF1 represented by the following formula of the toner for developing an electrostatic charge image according to this embodiment is preferably in the range of 110 to 140, more preferably in the range of 115 to 130.
SF1 = (ML ² / A) × (π / 4) × 100
[In the above formula, ML represents the maximum toner length (μm), and A represents the projected area (μm ² ) of the toner. ]
If the toner shape factor SF1 is smaller than 110 or exceeds 140, it may be impossible to obtain excellent charging properties, cleaning properties, and transfer properties over a long period of time.

  The shape factor SF1 is measured as follows using a Luzex image analyzer (FT manufactured by Nireco Corporation). First, an optical microscope image of the toner spread on the slide glass is taken into a Luzex image analyzer through a video camera, and the maximum length (ML) and projection area (A) of 50 toners are measured to obtain the shape factor SF1. .

<Method for producing toner for developing electrostatic image>
As a method for producing an electrostatic image developing yellow toner according to this embodiment, a conventional kneading and pulverizing method, a colorant, a release agent, etc. are suspended together with a polymerizable monomer, and the polymerizable monomer is polymerized. A suspension polymerization method in which a toner constituent material such as a suspension polymerization method, a resin, a colorant, a release agent, etc. is dissolved in an organic solvent and dispersed in an aqueous solvent in a suspended state, and then the organic suspension is removed. There is a wet manufacturing method such as emulsion polymerization aggregation method, which is prepared by emulsion polymerization, heteroaggregated with a dispersion of colorant, release agent, etc., and then fused and coalesced. There is no particular limitation as long as it is a production method that can be unevenly distributed on the surface. Among these, a wet production method such as a suspension polymerization method, a dissolution suspension method, and an emulsion polymerization agglomeration method is preferable, and it has toner particle size controllability, narrow particle size distribution, shape controllability, narrow shape distribution, and internal dispersion controllability. Therefore, the emulsion polymerization aggregation method is optimal.

  In general, the emulsion polymerization aggregation method is a step of emulsifying a binder resin or the like to form emulsified particles (droplets) and preparing a resin particle dispersion in which resin particles having a particle size of 1 μm or less are dispersed (hereinafter referred to as “emulsification”). Process particles), a resin particle dispersion, a colorant dispersion in which a colorant is dispersed, a release agent dispersion in which a release agent is dispersed, and the like are mixed to obtain resin particles, a colorant, and a release agent. A step of aggregating the agent into a toner particle size (hereinafter sometimes referred to as “aggregation step”), a step of heating the resin particles to a temperature equal to or higher than the glass transition point of the resin particles to fuse the aggregates to form toner particles (hereinafter “ Sometimes referred to as a “fusion process”).

[Emulsification process]
In the emulsification step, the emulsified particles (droplets) of the binder resin are formed by applying a shearing force to a solution obtained by mixing an aqueous solvent and a mixed liquid containing the binder resin.

  At that time, the viscosity of the mixed liquid can be lowered to form emulsified particles by heating or by dissolving the binder resin in an organic solvent. Moreover, a dispersing agent can also be used in order to stabilize emulsified particles and prevent thickening of the aqueous solvent. Such a dispersion of emulsified particles is referred to as a “resin particle dispersion”.

  Examples of the organic solvent include ethyl acetate, toluene, and the like, and can be appropriately selected and used according to the type and structure of the binder resin.

  As the usage-amount of the said organic solvent, it is preferable that it is the range of 50-5000 weight part with respect to 100 weight part of total amounts of resin, and it is more preferable that it is the range of 120-1000 weight part.

  Examples of the dispersant include water-soluble polymers such as polyvinyl alcohol, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, sodium polyacrylate, and sodium polymethacrylate, sodium dodecylbenzenesulfonate, sodium octadecylsulfate, and oleic acid. Anionic surfactants such as sodium, sodium laurate, potassium stearate, cationic surfactants such as laurylamine acetate, stearylamine acetate, lauryltrimethylammonium chloride, zwitterionic surfactants such as lauryldimethylamine oxide, Such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkylamine, etc. Anion surfactants such as surfactants, tricalcium phosphate, aluminum hydroxide, calcium sulfate, calcium carbonate, and inorganic compounds such as barium carbonate.

  When an inorganic compound is used as the dispersant, a commercially available one may be used as it is, but a method of generating inorganic compound particles in the dispersant may be employed for the purpose of obtaining fine particles. As the usage-amount of the said dispersing agent, the range of 0.01-20 weight part is preferable with respect to 100 weight part of resin.

  Examples of the emulsifier used when forming the emulsified particles include a homogenizer, a homomixer, a pressure kneader, an extruder, and a media disperser. The size of the emulsified particles (droplets) of the resin is preferably in the range of 0.01 μm to 1 μm, more preferably in the range of 0.03 μm to 0.3 μm, in terms of the average particle size (volume average particle size). The range of 03 μm to 0.4 μm is more preferable.

  The colorant dispersion includes a step of mixing and dispersing a yellow colorant, abietic acid, a surfactant having an HLB value of 4 or less and a solvent to obtain a colorant composition, and the colorant composition in an aqueous solvent. And a step of obtaining a colorant dispersion by dispersing in the above.

  In the step of obtaining a colorant composition by mixing and dispersing a yellow colorant, abietic acid, a surfactant having an HLB value of 4 or less, and a solvent, an arbitrary method such as a rotary shearing type homogenizer or a medium is used. A general dispersion method such as a ball mill, a sand mill, or a dyno mill can be used, and is not limited at all. Normally, after mixing and dispersing a yellow colorant, abietic acid, a surfactant having an HLB value of 4 or less, and a solvent, adding abietic acid and a surfactant having an HLB value of 4 or less, and further mixing ,scatter.

  As the solvent, general organic solvents such as toluene and tetrahydrofuran can be used. The coloring agent, abietic acid used, the type of surfactant, the structure, etc. can be appropriately selected and used.

  The amount of the organic solvent used is preferably in the range of 50 to 5000 parts by weight, and in the range of 120 to 1000 parts by weight with respect to 100 parts by weight of the total amount of the colorant, abietic acid, and the surfactant. Is more preferable.

  Next, the colorant composition thus obtained is dispersed in an aqueous solvent or the like to obtain a colorant dispersion. An aqueous dispersion or an organic solvent dispersion of the colorant is referred to as a “colorant dispersion”. As the surfactant and dispersant used for dispersion, the same dispersants as used when dispersing the binder resin can be used.

  As a method for dispersing the colorant, an arbitrary method, for example, a general dispersion method such as a rotary shear type homogenizer, a ball mill having a medium, a sand mill, or a dyno mill can be used, and the method is not limited at all.

  The addition amount of the colorant is preferably 1 to 20% by weight, more preferably 1 to 10% by weight, and more preferably 2 to 10% by weight with respect to the total amount of the binder resin. More preferably, the range is 2 to 7% by weight.

  As the release agent, an aqueous dispersion of the release agent is prepared using a surfactant, or an organic solvent dispersion of the release agent is prepared using a dispersant. Such an aqueous dispersion or organic solvent dispersion of a release agent is referred to as a “release agent dispersion”. As the surfactant and dispersant used for dispersion, the same dispersants as used when dispersing the binder resin can be used.

[Aggregation process]
In the aggregation step, the obtained resin particle dispersion, colorant dispersion, and release agent dispersion are heated to a temperature near the melting point of the binder resin and below the melting point to form an aggregate. . The heating time may be performed so that the aggregation is sufficiently performed, and for example, it may be performed for about 0.5 hours to 10 hours.

  Formation of the aggregate of the emulsified particles is performed by acidifying the pH of the emulsion under stirring. As the said pH, the range of 2-6 is preferable, The range of 2.5-5 is more preferable, The range of 2.5-4 is further more preferable. At this time, it is also effective to use a flocculant.

  As the flocculant to be used, a surfactant having a reverse polarity to the surfactant used for the dispersant, an inorganic metal salt, and a metal complex having a valence of 2 or more can be preferably used. In particular, the use of a metal complex is particularly preferable because the amount of the surfactant used can be reduced and the charging characteristics are improved.

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

  The solid content concentration of the reaction solution at the time of aggregation is usually in the range of 5% by weight to 20% by weight, preferably in the range of 10% by weight to 15% by weight. When the solid content concentration of the reaction solution is less than 5% by weight or exceeds 20% by weight, aggregation may not easily occur.

[Fusion process]
In the fusion step, under the same stirring as in the aggregation step, the aggregation suspension is stopped by setting the pH of the aggregate suspension to a range of 3 to 7, and heated at a temperature equal to or higher than the melting point of the crystalline polyester resin. To fuse the aggregates.

  There is no problem if the heating temperature is equal to or higher than the melting point of the binder resin.

  The heating time may be performed to such an extent that the fusion is sufficiently performed, for example, about 0.5 to 10 hours.

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

  Examples of the polymerization initiator include t-butyl peroxy-2-ethylhexanoate, cumyl perpivalate, t-butyl peroxylaurate, benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, di-t. -Butyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide, 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane 1,1-bis (t-butylperoxy) cyclohexane, 1,4-bis (t-butylperoxycal) Nyl) cyclohexane, 2,2-bis (t-butylperoxy) octane, n-butyl 4,4-bis (t-butylperoxy) valerate, 2,2-bis (t-butylperoxy) butane, , 3-bis (t-butylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylper) Oxy) hexane, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, di-t-butyldiperoxyisophthalate, 2,2-bis (4,4-di-t-butylperoxy) (Cyclohexyl) propane, di-t-butylperoxy α-methylsuccinate, di-t-butylperoxydimethylglutarate, di-t-butylperoxyhexahydroterephthalate Rate, di-t-butylperoxyazelate, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, diethylene glycol-bis (t-butylperoxycarbonate), di-t-butylper Oxytrimethyl adipate, tris (t-butylperoxy) triazine, vinyltris (t-butylperoxy) silane, 2,2'-azobis (2-methylpropionamidine dihydrochloride), 2,2'-azobis [N- (2-carboxyethyl) -2-methylpropionamidine], 4,4′-azobis (4-cyanovaleric acid) and the like.

  These polymerization initiators can be used alone or in combination of two or more. The amount and type of the polymerization initiator are selected depending on the amount of unsaturated sites in the polymer and the type and amount of the coexisting colorant.

  The polymerization initiator may be mixed with the binder resin in advance before the emulsification step, or may be incorporated into the aggregate in the aggregation step. Further, it may be introduced after the fusion step or after the fusion step. In the case of introduction after the aggregation step, the fusion step, or the fusion step, a solution in which the polymerization initiator is dissolved or emulsified is added to a particle dispersion (resin particle dispersion or the like). These polymerization initiators may be added with known crosslinking agents, chain transfer agents, polymerization inhibitors and the like for the purpose of controlling the degree of polymerization.

(Shell layer forming process)
Next, a method for forming a shell layer as necessary will be described. In the toner according to the exemplary embodiment, a method for forming a shell layer includes an agglomeration step in which amorphous resin particles or the like are adhered to the aggregated particles (core particles) to form amorphous resin-adhered particles; And a melting step of forming the shell layer by heating the conductive resin adhering particles. About the formation method of the shell layer which has an amorphous resin fine particle as a main component, it is preferable to carry out in water from a viewpoint of productivity.

  The shell layer may be formed as the same process performed simultaneously by adding the amorphous particle dispersion during granulation by the emulsion polymerization aggregation method as described above, or as a separate process after the core particles are prepared. However, the shell layer formation is preferably performed as a separate process in the aqueous medium after the core particles are prepared.

  In the shell layer forming step, the solid content concentration during coating is preferably in the range of 10 to 50% by weight, more preferably in the range of 20 to 50% by weight, and in the range of 30 to 50% by weight. Is more preferable. If it is 10% by weight or less, not only the dispersion stability is low, but also the dispersion stability is lowered, and the adhesion of the amorphous resin particles to the core particle surface may be insufficient. On the other hand, when the solid content concentration is 50% by weight or more, an increase in slurry viscosity at the time of adhesion may cause an agitation failure, which may cause generation of coarse powder.

  In the formation of the shell layer, the slurry liquid may be heated for the purpose of obtaining a strong shell layer after adding the amorphous resin particle dispersion to the slurry liquid after granulation of the core particles. At this time, it is important to heat at or below the melting point or glass transition temperature of the binder resin of the core particles. When the heating temperature is too high, not only coarse powder is generated, but also the core component is eluted on the surface of the shell layer, which may deteriorate charging characteristics and heat storage properties.

  In the formation of the shell layer, a flocculant may be used for the purpose of promoting the coating of the amorphous resin particles. As the flocculant, the flocculant species described later is preferably used. Further, the timing of adding the flocculant may be before or after the addition of the amorphous resin particles.

  In the preparation of the toner shell layer of the present embodiment, as described above, the addition amount of the amorphous resin particles is preferably in the range of 5 to 25% by weight, and 7 to 20% by weight with respect to the weight of the core particles. Is more preferable, and it is further more preferable that it is the range of 7-16 weight%. When the addition amount is less than 5% by weight, the heat storage property becomes insufficient, and blocking is likely to occur in the actual machine. When the addition amount exceeds 25% by weight, there is no problem in thermal storage, but charging characteristics and low-temperature fixability may be hindered.

(Washing and drying process)
When toner particles are prepared using an emulsion polymerization aggregation method, etc., after removing the dispersant with an aqueous solution of strong acid such as hydrochloric acid, sulfuric acid, nitric acid, etc., rinse with ion exchange water etc. until the filtrate becomes neutral. A desired toner is obtained through a washing step, a solid-liquid separation step, and a drying step. In this case, in order to ensure sufficient charging characteristics and reliability as a toner, it is preferable to sufficiently wash with ion exchange water or the like in the washing step.

  In the drying process, an arbitrary method such as a normal vibration type fluidized drying method, a spray drying method, a freeze drying method, or a flash jet method can be adopted. It is desirable that the toner particles have a moisture content after drying of 1.0% or less, preferably 0.5% or less.

<Electrostatic image developer>
In the exemplary embodiment, the electrostatic charge image developer is not particularly limited except that it contains the yellow toner for developing an electrostatic charge image, and can have an appropriate component composition according to the purpose. The electrostatic charge image developer may be a one-component electrostatic charge image developer using an electrostatic charge image developing toner alone, or may be used in combination with a carrier as a two-component electrostatic charge image developer. Also good.

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

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

  The mixing ratio of the electrostatic image developing toner and carrier in the electrostatic image developer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, toner: carrier = 1: 100 to 30: 100 The range of about 3: 100 to 20: 100 is more preferable.

  Further, as the coating resin of the resin-coated carrier, it is preferable to use a resin containing a crystalline polyester resin and an amorphous resin. As a result, by maintaining the charging and carrier resistance stably, it is possible to obtain a carrier for developing an electrostatic latent image free of image density reproducibility, a color image excellent in halftone without an edge effect, and other image defects. Thereby, the charge maintaining property of the yellow toner for developing an electrostatic image according to this embodiment can be improved. As the crystalline polyester resin and the amorphous resin, those similar to the crystalline polyester resin and the amorphous resin described above in the section of yellow toner for developing electrostatic images can be used.

  As the crystalline polyester resin, an aliphatic crystalline polyester resin is more preferable from the viewpoint of adjusting the melting point within a preferable range. Further, as the amorphous resin, an amorphous polyester resin is particularly preferable.

  In general, a crystalline polyester resin having a low crystallinity and a relatively low melting point generally has low electric resistance, low resin strength, and low chargeability. The reason why the resistance is low is that the amorphous part of the crystalline resin has a glass transition temperature below the room temperature range, and above this glass transition temperature, the amorphous part has molecular chain segmental motion. It is considered that the movement of the molecule prevents the electric charge from being held and the electric resistance of the crystal resin itself is low. By making use of the electrical resistance characteristics of this crystalline polyester resin to make a carrier coating resin, in order to ensure a uniform coating resin layer strength, it can be mixed with a crystalline resin that is compatible with the crystalline resin. It is possible to obtain a carrier coating resin having uniform resin layer strength and resistance.

  The electrostatic charge image developing carrier according to this embodiment is coated with a resin obtained by mixing a crystalline polyester resin and an amorphous resin with a coating resin layer resin. When these resins are mixed and used as a coating resin, it is most important that they are in an appropriate compatible state. This is because the crystalline polyester resin originally lacks the strength but develops the strength of the coating resin layer by compatibilization.

  As an index representing the degree of compatibilization between the crystalline polyester resin and the amorphous resin, it has been found that it is most effective to represent the change in the endothermic peak temperature derived from the crystalline resin in differential scanning calorimetry (DSC). This indicates that the crystallinity of the crystalline resin collapses due to the compatibilization of the crystalline resin and the noncrystalline resin, and the melting point of the crystalline resin is lowered. Especially when the compatibility is significant, the crystalline resin The derived endothermic peak temperature is also significantly reduced.

Therefore, in the carrier, the endothermic peak temperature TmA (° C.) derived from the crystalline polyester resin of the coating resin and the endothermic peak temperature TmAB (° C.) derived from the crystalline polyester resin when the crystalline polyester resin and the amorphous resin are mixed. And satisfy the relationship of the following formula (1).
5 ≦ TmA−TmAB ≦ 20 (1)

  In the present embodiment, the difference obtained by subtracting TmAB (° C.) from TmA (° C.) is preferably 5 ° C. to 20 ° C., and more preferably 8 ° C. to 15 ° C. If the difference obtained by subtracting TmAB (° C.) from TmA (° C.) is 5 ° C. to 20 ° C., it indicates that the crystalline polyester resin and the non-crystalline resin have an appropriate compatibility. When the difference obtained by subtracting TmAB (° C) from TmA (° C) is less than 5 ° C, the compatibility between the crystalline polyester resin and the amorphous resin is low, and the crystalline polyester resin and the amorphous resin have a sea-island structure. In some cases, the strength of the carrier-coated resin layer is lowered. Furthermore, when the difference between TmA (° C) and TmAB (° C) exceeds 20 ° C, the compatibility is increased, the resin layer itself is plasticized, and the heat resistant storage stability and blocking property of the developer are significantly reduced. There is.

  Moreover, it is preferable that the endothermic peak temperature TmA derived from the crystalline polyester resin contained in the resin layer coated on the carrier core material is in the range of 50 ° C to 100 ° C.

  The TmA (° C.) and TmAB (° C.) are measured using a thermal analyzer of a differential scanning calorimeter (manufactured by Max Science, DSC3110, thermal analysis system 001, hereinafter sometimes referred to as “DSC”). can do. In the first temperature raising step, the temperature is raised from room temperature to 150 ° C. at a rate of 10 ° C. per minute, held at 150 ° C. for 5 minutes, and then liquefied nitrogen is used to reach 0 ° C. at a rate of 10 ° C. per minute After the temperature was lowered and held at 0 ° C. for 5 minutes, the temperature was increased again from 0 ° C. to 150 ° C. at a rate of 10 ° C. per second as the second temperature raising step, and the obtained differential scanning calorimetry curve was expressed in JIS K-7121-1987. To obtain an endothermic peak.

  The TmAB (° C.) was prepared by mixing a crystalline resin and an amorphous resin with 80 parts by weight of the amorphous resin with respect to 20 parts by weight of the crystalline resin, and then placing the sample on an aluminum dish. The sample was measured after standing for 2 hours at room temperature, gradually cooling at room temperature, and then crushing the molten sample with a mortar.

  Moreover, it is preferable that the mixing weight ratio (A / B) of the crystalline polyester resin and the amorphous resin coated on the carrier core material is 1/99 to 40/60. More preferably, it is 10 / 90-30 / 70. When the content of the crystalline polyester resin exceeds 40% by weight, the strength of the coating resin layer is lowered, the wear of the carrier resin layer is deteriorated, and the charge can be lowered due to the contamination of the carrier component of the toner component such as the toner external additive. There is sex. On the other hand, if the content of the crystalline polyester resin is less than 1% by weight, the resistance control effect of the carrier coating resin layer due to the addition of the crystalline polyester resin layer is reduced, and an edge effect is generated in the solid image portion. If the reproducibility is lowered and the subject has a halftone like a photograph, the image may be very poorly reproducible.

  As melting | fusing point of crystalline resin, Preferably it is 50-100 degreeC, More preferably, it is 60-80 degreeC. When the melting point of the crystalline resin is lower than 50 ° C., the heat-resistant storage stability of the carrier, blocking as a developer, adhesion of a toner component, etc. may become problems. On the other hand, if the melting point of the crystalline resin is higher than 100 ° C., it is difficult to dissolve in a solvent, or the effect as a resistance control agent may be insufficient. The crystalline resin may show a plurality of melting peaks, but the maximum peak is regarded as the melting point.

Further, when an electric field of ^103.4 V / cm is applied in an environment where the resistance of the crystalline polyester resin contained in the resin layer coated on the carrier core is 28 ° C. and the relative humidity is 85%, 1.0 × It is preferably 10 ^{10 to} 1.0 × 10 ¹⁴ Ω · cm. When the resin resistance is less than 1.0 × 10 ¹⁰ , the chargeability under high temperature and high humidity decreases, and when the resin resistance exceeds 1.0 × 10 ¹⁴ Ω · cm, the crystalline polyester resin layer is added. The resistance control effect of the carrier coating resin layer is reduced, the edge effect occurs in the solid image area, and the solid reproducibility is reduced. When the subject has a halftone like a photograph, the reproducibility is very poor. It may become an image.

The volume resistance at the time of compression of the carrier is preferably 1.0 × 10 ^{9 to} 1.0 × 10 ¹⁴ Ω · cm when an electric field of 10 ^3.8 V / cm is applied. If it is less than 1.0 × 10 ⁹ Ω · cm, it is difficult to suppress carrier adhesion for a long time, and if it exceeds 1.0 × 10 ¹⁴ Ω · cm, the edge effect appears strongly and the development density of the solid image There arises a problem that developability such as lowering is impaired. A more preferable range is 1.0 × 10 ^{9 to} 1.0 × 10 ¹³ Ω · cm, and still more preferably 1.0 × 10 ^{10 to} 1.0 × 10 ¹² Ω · cm.

As the core material used for the carrier, known materials exhibiting ferromagnetism can be used, and specific examples include magnetic metals such as iron, steel, nickel and cobalt, and magnetic oxides such as ferrite and magnetite. Among them, low specific gravity ferrite particles capable of suppressing peeling of the resin coating layer due to stress received in the developing device and toner contamination on the carrier surface are suitable. The ferrite is composed mainly of an oxide of one or more elements selected from Li, Mg, Ca, Mn, Ni, Cu, and Zn and Fe ₂ O ₃ and is formed by granulation and sintering. It is preferable from the viewpoint of magnetization, and among them, those mainly composed of an oxide of one or more elements selected from Li, Mg, and Mn and Fe ₂ O ₃ are preferable from the viewpoints of magnetization, electrical resistance, and environmental safety. .

  The volume average particle size of the magnetic particles is preferably in the range of 20 to 45 μm. When the volume average particle diameter of the magnetic particles exceeds 45 μm, the coating layer is peeled off due to stress in the developing machine, the carrier resistance is lowered, the head of the magnetic brush becomes rough, and a fine line or a precise electrostatic latent image is formed. The reproducibility may be impaired. On the other hand, if the volume average particle size of the magnetic particles is less than 20 μm, the rising of the developer becomes too soft, and the carrier resistance increases, and the magnetic force per carrier particle decreases. In some cases, the magnetic binding force of the toner is defeated by the centrifugal force when the developing sleeve rotates, and carrier adhesion and carrier consumption to the photosensitive member may occur.

  In addition, the magnetic force of the magnetic particles preferably has a saturation magnetic value at 3000 oersted of 50 emu / g or more, more preferably 60 emu / g or more. With a magnetic force whose saturation magnetic value is less than 50 emu / g, carrier adhesion and carrier consumption to the photoreceptor may occur more significantly.

  The carrier coating resin layer may be further used in combination with conductive powder for carrier resistance adjustment. Examples of the conductive powder include metal powder, carbon black, titanium oxide, tin oxide, and zinc oxide. These conductive powders preferably have a volume average particle diameter of 1 μm or less. When the volume average particle diameter is larger than 1 μm, it is difficult to control the dispersion of the powder in the resin coating layer, and it may be difficult to control the electric resistance.

The addition amount of the conductive powder is preferably less than 20% by volume of the coating coat layer of the carrier core material. When 20 volume% or more is added, it is difficult to control the dispersion of the powder in the resin coating layer, and it may be difficult to control the electric resistance. Conductivity of the conductive powder itself is preferably from 1.0 × ^{10 10} Ω · cm, more preferably at most 1.0 × 10 ⁹ Ω · cm. Furthermore, a conductive resin or the like can be used in combination as necessary.

  The weight ratio of the carrier core material to the resin coating layer is preferably 100: 2 to 100: 4. The reason for this range is that even if the resin coating layer is worn due to stress or the like in the developing machine, it is possible to suppress an extreme decrease in carrier resistance. When the resin coating ratio is less than 2, it is difficult to maintain the carrier resistance for a long time, and when it is 4 or more, the carrier productivity is difficult and the fluidity of the developer in the developing machine deteriorates. There is.

  Further, it is preferable that crosslinked resin particles imparting negative chargeability to the toner are dispersed in the resin coated on the carrier core material. It is possible to obtain excellent charge maintaining properties by mixing the resin particles that give the toner with negative chargeability in the carrier coating resin layer.

  Further, by adding the crosslinked resin particles, it is possible to improve the stable charge imparting ability and mechanical strength. As the crosslinked resin particles, either thermoplastic resin particles or thermosetting resin particles can be used, but it is preferable to use thermosetting resin particles that are relatively easy to increase the hardness.

  Examples of thermoplastic resins are specifically polyolefin resins such as polyethylene, polypropylene; polyvinyl and polyvinyl and polyvinylidene resins such as polystyrene, acrylic resin, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polychlorinated. Examples thereof include vinyl, polyvinyl carbazole, polyvinyl ether and polyvinyl ketone; vinyl chloride-vinyl acetate copolymer; styrene-acrylic acid copolymer; straight silicone resin composed of an organopolysiloxane bond or a modified product thereof; polyester;

  Examples of the thermosetting resin include phenol resin; amino resin, urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin; epoxy resin, and the like.

  In order to produce the fine particle form, any method may be used as long as an appropriate particle size as described later can be obtained. For example, a method of producing a granular resin using a polymerization method such as suspension polymerization, emulsion polymerization, suspension polymerization, etc., a method of dispersing a monomer or oligomer in a poor solvent and granulating by surface tension while performing a crosslinking reaction Examples thereof include a method in which a low molecular component and a crosslinking agent are mixed and reacted by melt kneading or the like and then pulverized to a predetermined particle size by wind force or mechanical force.

  The volume average particle diameter of the crosslinked resin particles is preferably in the range of 0.1 to 2 μm. More preferably, it is the range of 0.2-1.0 micrometer. If the thickness is smaller than 0.1 μm, the coating layer is aggregated and dispersion is very poor. If the thickness is larger than 2 μm, the coating layer is likely to fall off, and the original function may not be maintained.

  The addition amount of the crosslinked resin particles is 1 to 20% by volume, preferably 5 to 10% by volume in the carrier coating layer. When the addition amount is more than 20% by volume, it is difficult to disperse in the coating coat layer, and the strength of the coating layer may be lowered.

  The crosslinked resin particles are required to impart negative chargeability to the toner, and preferably contain atoms having electron donating properties as constituent components.

  As a typical method for forming a coating resin on a carrier core material, a raw material solution for forming a resin coating layer (a crystalline polyester resin, an amorphous resin, crosslinked resin particles, conductive fine powder, etc. are appropriately contained in a solvent) For example, a dipping method in which a carrier core material powder or a charge imparting member is immersed in a resin coating layer forming solution, a spray method in which a resin coating layer forming solution is sprayed on the surface of the carrier core material or charge imparting member, A fluidized bed method in which a solution for forming a resin coating layer is sprayed in a state where the carrier core material is suspended by flowing air, a kneader coater for mixing the carrier core material and the resin coating layer forming solution in a kneader coater, and then removing the solvent. However, it is not particularly limited to those using a solution, and depending on the carrier core material and the charge imparting member to be applied, the powder mixed with the resin powder by heating is mixed. -Coating method can be adopted as appropriate, but in order to disperse the resin fine particles and conductive fine powder, the carrier core material is dissolved in a coating resin solution dissolved with a solvent that dissolves the crystalline resin and the amorphous resin. It is preferred that the carrier be produced by dipping and removing the solvent in a vacuum while applying shear.

  The solvent used in the raw material solution for forming the resin coating layer is not particularly limited as long as it dissolves the resin. For example, aromatic hydrocarbons such as xylene and toluene, ethyl acetate, acetone , Ketones such as methyl ethyl ketone, ethers such as tetrahydrofuran and dioxane, halides such as chloroform and carbon tetrachloride, and the like can be used.

  Since the crosslinked resin particles are preferably in the form of particles even in the solvent, it is preferable that the crosslinked resin particles are not substantially soluble in the solvent (solvent hardly soluble). As a result, the crosslinked resin particles do not aggregate in the resin coating layer, and maintain the form of primary particles.

  In addition, the electrostatic charge image developer according to the present embodiment supplies a replenishment developer when developing a latent image on a latent image carrier using a developing machine containing a two-component developer composed of toner and carrier. However, it can be used in a trickle development system in which development is performed.

  In addition, it is preferable that the electrostatic latent image developing carrier has a lower electrical resistance than that of the replenishment carrier in advance in the initial developer contained in the developing machine.

  As a result, in the two-component development method and development apparatus using the trickle development method, even if a relatively small amount of carrier is replenished, the electrical resistance value and the charge amount of the two-component developer in the developer accommodating portion can be reduced by long-term use. Both are maintained within an appropriate range without greatly changing, and stable image quality can be obtained over a long period of time. Thereby, the charge maintaining property of the yellow toner for developing an electrostatic image according to this embodiment can be improved.

  The volumetric electric resistance of the replenishment carrier is preferably higher than that of the initial developer carrier, and the electric resistance of the carrier contained in the replenishment developer is made higher than the electric resistance of the carrier contained in the initial developer. As a result, it is possible to reduce the variation amount of the developer charge amount and the developer resistance in the developing machine, and it is possible to obtain a good image quality over a long period of time.

The volume electrical resistance of the replenishment carrier is preferably 1.0 × 10 ¹⁰ Ω · cm or more. If the volume electric resistance is less than 1.0 × 10 ¹⁰ Ω · cm, the effect of suppressing the decrease in the developer resistance with time is small, and this may cause the carrier to fly due to fogging and leakage due to a decrease in the charge amount. There is.

  It is preferable that the charge imparting ability of the replenishment carrier to the toner is set to be higher than that of the initial use carrier. Specifically, the charge amount is set to 1.2 to 2 times, more preferably about twice the charge amount of the initial use carrier, and is obtained by frictional charging by stirring with toner for a certain period of time. The saturation charge amount of the replenishment carrier is 1.2 to 2 times, more preferably 1.5 to 22 times the saturation charge amount of the initial use carrier. When the saturation charge amount of the replenishment carrier exceeds twice the saturation charge amount of the initial use carrier, the charge distribution becomes broad, and image quality problems such as density reduction or fogging may occur.

  The mixing ratio of the toner and the carrier contained in the replenishment developer is preferably 0.05 to 0.4 parts by weight of the replenishment carrier with respect to 1 part by weight of the toner. If it is less than 0.05 parts by weight, the volume electrical resistance and charge amount of the carrier contained in the developer may not be maintained within an appropriate range. Further, when the replenishment carrier is increased from 0.4 part by weight with respect to 1 part by weight of toner, the amount of trickle carrier increases, so that the amount of waste carrier increases and the amount of collection increases, which may increase the size of the apparatus. .

<Image forming method>
The image forming method according to the present embodiment uses a latent image forming step of forming an electrostatic latent image on the surface of the latent image carrier and a developer carried on the developer carrier, and is formed on the surface of the latent image carrier. A development process for developing the electrostatic latent image to form a toner image, a transfer process for transferring the toner image formed on the surface of the latent image holding body to the surface of the transfer target, and a toner transferred to the surface of the transfer target In the image forming method including a fixing step for fixing an image, the electrostatic image developer containing the yellow toner for developing an electrostatic image of the present embodiment is used as a developer.

  The developer may be either a one-component system or a two-component system. As each of the above steps, a known step in the image forming method can be used. The image forming method according to the present embodiment may include steps other than the steps described above.

  As the latent image holding member, for example, an electrophotographic photosensitive member and a dielectric recording member can be used. In the case of an electrophotographic photosensitive member, the surface of the electrophotographic photosensitive member is uniformly charged by a corotron charger, a contact charger or the like and then exposed to form an electrostatic latent image (latent image forming step). Next, the toner particles are attached to the electrostatic latent image by contacting or approaching a developing roll having a developer layer formed on the surface, thereby forming a toner image on the electrophotographic photosensitive member (developing step). The formed toner image is transferred onto the surface of a transfer medium such as paper using a corotron charger or the like (transfer process). Further, the toner image transferred to the surface of the transfer target is heat-fixed by a fixing machine (fixing step) to form a final toner image.

  Examples of the transfer target (recording material) to which the toner image is transferred include plain paper, OHP sheet, and the like used for electrophotographic copying machines and printers. In order to further improve the smoothness of the image surface after fixing, it is preferable that the surface of the transfer object is as smooth as possible. For example, coated paper in which the surface of plain paper is coated with a resin or the like, art paper for printing Etc. can be used suitably.

  Since the image forming method according to the present embodiment uses the electrostatic charge image developer (the toner according to the present embodiment), stable and good color reproducibility can be realized.

  Hereinafter, although an example and a comparative example are given and the present invention is explained more concretely in detail, the present invention is not limited to the following examples.

  The toner in this embodiment is obtained by the following method. That is, the following resin particle dispersion, colorant dispersion, release agent dispersion, and inorganic particle dispersion are prepared. Next, while a predetermined amount of these are mixed and stirred, a polymer of an inorganic metal salt is added thereto and ionically neutralized to form aggregates of the particles. Before reaching the desired toner particle size, resin particles are added to adjust the toner particle size. Next, the pH of the system is adjusted from a weakly acidic to a neutral range with an inorganic hydroxide, and then heated to a temperature equal to or higher than the glass transition temperature of the resin particles so as to fuse together. After completion of the reaction, a desired toner is obtained through sufficient washing, solid-liquid separation, and drying processes. Details are described below.

(Adjustment of Colorant Composition 1)
C. I Pigment Yellow 74 (Clariant, Brilliant Yellow 5GX) 82 parts by weight Toluene 300 parts by weight After mixing with a homogenizer (IKA Ultra Tarrax) for 10 minutes, rosin (product name: Pine Crystal KR85, manufactured by Arakawa Chemical Co., Ltd.) 10 parts by weight of acid value 170 mg KOH / g, softening point 84 ° C.) and 8 parts by weight of surfactant octylphenol ethoxylate (manufactured by Dow Chemical Co., X-15, HLB value = 3.6) were further dispersed for 1 hour. Thus, a colored composition 1 having a volume average particle diameter of the pigment of 0.1 μm was obtained.

(Adjustment of Colorant Composition 2)
C. I Pigment Yellow 74 (Clariant, Brilliant Yellow 5GX) 71 parts by weight Toluene 300 parts by weight After mixing with a homogenizer (IKA Ultra Tarrax) for 10 minutes, rosin (product name Pine Crystal KR85, manufactured by Arakawa Chemical Co., Ltd.) 10 parts by weight of acid value 170 mg KOH / g, softening point 84 ° C.) and 19 parts by weight of surfactant octylphenol ethoxylate (manufactured by Dow Chemical Co., X-15, HLB value = 3.6) were further dispersed for 1 hour. Thus, a colored composition 2 having a pigment volume average particle diameter of 0.13 μm was obtained.

(Adjustment of Colorant Composition 3)
C. I Pigment Yellow 74 (manufactured by Clariant, Brilliant Yellow 5GX) 89 parts by weight Toluene 300 parts by weight After mixing with a homogenizer (IKA Ultra Tarrax) for 10 minutes, rosin (product name: Pine Crystal KR85, manufactured by Arakawa Chemical Co., Ltd.) , 10 parts by weight of acid value 170 mg KOH / g, softening point 84 ° C.) and 1 part by weight of surfactant octylphenol ethoxylate (manufactured by Dow Chemical Co., X-15, HLB value = 3.6), and further dispersed for 1 hour Thus, a colored composition 3 having a volume average particle diameter of the pigment of 0.14 μm was obtained.

(Adjustment of Colorant Composition 4)
C. I Pigment Yellow 74 (Clariant, Brilliant Yellow 5GX) 70 parts by weight Toluene 300 parts by weight After mixing with a homogenizer (IKA Ultra Tarrax) for 10 minutes, rosin (product name Pine Crystal KR85, manufactured by Arakawa Chemical Co., Ltd.) , Acid value 170 mg KOH / g, softening point 84 ° C.) 22 parts by weight and surfactant octylphenol ethoxylate (Dow Chemical Co., X-15, HLB value = 3.6) 8 parts by weight were added and further dispersed for 1 hour. Thus, a colored composition 4 having a pigment volume average particle diameter of 0.14 μm was obtained.

(Adjustment of Colorant Composition 5)
C. I Pigment Yellow 74 (Clariant, Brilliant Yellow 5GX) 87 parts by weight Toluene 300 parts by weight After mixing with a homogenizer (IKA Ultra Tarrax) for 10 minutes, rosin (product name: Pine Crystal KR85, manufactured by Arakawa Chemical Co., Ltd.) 5 parts by weight of acid value 170 mg KOH / g, softening point 84 ° C.) and 8 parts by weight of surfactant octylphenol ethoxylate (manufactured by Dow Chemical Co., X-15, HLB value = 3.6) were further dispersed for 1 hour. Thus, a colored composition 5 having a pigment volume average particle diameter of 0.15 μm was obtained.

(Adjustment of Colorant Composition 6)
C. I Pigment Yellow 180 (Clariant, Fast Yellow HG) 82 parts by weight Toluene 300 parts by weight The above components were mixed and dispersed with a homogenizer (IKA Ultra Tarrax) for 10 minutes, followed by rosin (product name Hartle R-, manufactured by Harima Chemicals). X, acid value 168 mg KOH / g, softening point 79 ° C. 10 parts by weight and surfactant octylphenol ethoxylate (Dow Chemical Co., X-15, HLB value = 3.6) 8 parts by weight were added, and further 1 hour Dispersion was performed to obtain a colored composition 6 having a pigment volume average particle diameter of 0.16 μm.

(Adjustment of Colorant Composition 7)
C. I Pigment Yellow 93 (manufactured by Dainichi Seika Co., Ltd., Chromofine Yellow 5930) 82 parts by weight Toluene 300 parts by weight After mixing with a homogenizer (IKA Ultra Tarrax) for 10 minutes, rosin (manufactured by Arakawa Chemical Co., Ltd., product name) Pine crystal KR85, acid value 170 mg KOH / g, softening point 84 ° C. 10 parts by weight and surfactant octylphenol ethoxylate (X-15, HLB value = 3.6) by 8 parts by weight Dispersion was performed for 1 hour to obtain a colored composition 7 having a pigment volume average particle diameter of 0.17 μm.

(Adjustment of Colorant Composition 8)
C. I Pigment Yellow 74 (manufactured by Clariant, Brilliant Yellow 5GX) 82 parts by weight Toluene 300 parts by weight After mixing with a homogenizer (IKA Ultra Tarrax) for 10 minutes, rosin (product name: Pine Crystal KR100, manufactured by Arakawa Chemical Co., Ltd.) , 10 parts by weight of acid value 7 mg KOH / g, softening point 100 ° C.) and 8 parts by weight of surfactant octylphenol ethoxylate (X-15, HLB value = 3.6, manufactured by Dow Chemical Co.) and further dispersed for 3 hours Thus, a colored composition 8 having a pigment volume average particle diameter of 0.22 μm was obtained.

(Adjustment of Colorant Composition 9)
C. I Pigment Yellow 74 (Clariant, Brilliant Yellow 5GX) 82 parts by weight Toluene 300 parts by weight After mixing with a homogenizer (IKA Ultra Tarrax) for 10 minutes, rosin (product name: Pine Crystal KR85, manufactured by Arakawa Chemical Co., Ltd.) 10 parts by weight of acid value 170 mg KOH / g, softening point 84 ° C.) and 8 parts by weight of surfactant tetraglycerin pentaester (Sakamoto Pharmaceutical Co., Ltd., PO-3S, HLB value = 3.0) Dispersion with time was performed to obtain a colored composition 9 in which the volume average particle diameter of the pigment was 0.15 μm.

(Adjustment of the colorant composition 10)
C. I Pigment Yellow 74 (Clariant, Brilliant Yellow 5GX) 82 parts by weight Toluene 300 parts by weight After mixing with a homogenizer (IKA Ultra Tarrax) for 10 minutes, rosin (product name: Pine Crystal KR85, manufactured by Arakawa Chemical Co., Ltd.) 10 parts by weight of acid value 170 mg KOH / g, softening point 84 ° C.) and 8 parts by weight of surfactant tetraglycerin pentaester (manufactured by Sakamoto Pharmaceutical Co., Ltd., PS-3S, HLB value = 2.6), The coloring composition 10 in which the volume average particle diameter of the pigment was 0.16 μm was obtained by time dispersion.

(Adjustment of the colorant composition 11)
C. I Pigment Yellow 74 (Clariant, Brilliant Yellow 5GX) 82 parts by weight Toluene 300 parts by weight After mixing with a homogenizer (IKA Ultra Tarrax) for 10 minutes, rosin (product name: Pine Crystal KR85, manufactured by Arakawa Chemical Co., Ltd.) 10 parts by weight of acid value 170 mg KOH / g, softening point 84 ° C.) and 22 parts by weight of surfactant octylphenol ethoxylate (X-15, HLB value = 3.6, manufactured by Dow Chemical Co.) were further dispersed for 1 hour. Thus, a colored composition 11 having a volume average particle diameter of the pigment of 0.19 μm was obtained.

(Adjustment of Colorant Composition 12)
C. I Pigment Yellow 74 (Clariant, Brilliant Yellow 5GX) 82 parts by weight Toluene 300 parts by weight After mixing with a homogenizer (IKA Ultra Tarrax) for 10 minutes, rosin (product name: Pine Crystal KR85, manufactured by Arakawa Chemical Co., Ltd.) 10 parts by weight of acid value 170 mg KOH / g, softening point 84 ° C.) and 0.4 part by weight of surfactant octylphenol ethoxylate (X-15, HLB value = 3.6, manufactured by Dow Chemical Co.) Dispersion was performed over time to obtain a colored composition 12 having a pigment volume average particle diameter of 0.2 μm.

(Adjustment of the colorant composition 13)
C. I Pigment Yellow 74 (Clariant, Brilliant Yellow 5GX) 82 parts by weight Toluene 300 parts by weight After mixing with a homogenizer (IKA Ultra Tarrax) for 10 minutes, rosin (product name: Pine Crystal KR85, manufactured by Arakawa Chemical Co., Ltd.) 26 parts by weight of acid value 170 mg KOH / g, softening point 84 ° C.) and 8 parts by weight of surfactant octylphenol ethoxylate (manufactured by Dow Chemical Co., X-15, HLB value = 3.6) were further dispersed for 1 hour. Thus, a colored composition 13 having a pigment volume average particle diameter of 0.2 μm was obtained.

(Adjustment of the colorant composition 14)
C. I Pigment Yellow 74 (Clariant, Brilliant Yellow 5GX) 82 parts by weight Toluene 300 parts by weight After mixing with a homogenizer (IKA Ultra Tarrax) for 10 minutes, rosin (product name: Pine Crystal KR85, manufactured by Arakawa Chemical Co., Ltd.) 2 parts by weight of acid value 170 mg KOH / g, softening point 84 ° C.) and 8 parts by weight of surfactant octylphenol ethoxylate (manufactured by Dow Chemical Co., X-15, HLB value = 3.6) were further added. Dispersion was performed over time to obtain a colored composition 14 having a pigment volume average particle diameter of 0.22 μm.

(Adjustment of the colorant composition 15)
C. I Pigment Yellow 74 (Clariant, Brilliant Yellow 5GX) 82 parts by weight Toluene 300 parts by weight After mixing with a homogenizer (IKA Ultra Tarrax) for 10 minutes, rosin (product name: Pine Crystal KR85, manufactured by Arakawa Chemical Co., Ltd.) 10 parts by weight of acid value 170 mg KOH / g, softening point 84 ° C.) and 8 parts by weight of surfactant tetraglycerin triester (manufactured by Sakamoto Pharmaceutical Co., Ltd., TS-3S, HLB value = 4.5), Dispersion was performed over time to obtain a colored composition 15 having a pigment volume average particle diameter of 0.21 μm.

(Adjustment of the colorant composition 16)
C. I Pigment Yellow 74 (manufactured by Clariant, Brilliant Yellow 5GX) 100 parts by weight Toluene 300 parts by weight The above is mixed and dispersed with a homogenizer (IKA Ultra Tarrax) for 10 minutes, and the pigment has a volume average particle diameter of 0.22 μm A composition 16 was obtained.

(Preparation of yellow colorant dispersion 1)
Colorant composition 1 33 parts by weight Ionic surfactant Neogen RK (Daiichi Kogyo Seiyaku Co., Ltd.) 4.02 parts by weight Ion-exchanged water 200 parts by weight The above is mixed and dissolved, and dispersed for 10 minutes with a homogenizer (IKA Ultra Turrax) As a result, a yellow colorant dispersion liquid 1 having a volume average particle size of 120 nm was obtained.

(Preparation of yellow colorant dispersions 2-16)
In the same manner as in the colorant dispersion 1, yellow colorant dispersions 2 to 16 were prepared using the colorant compositions 2 to 16.

(Preparation of cyan colorant dispersion)
Cyan pigment (copper phthalocyanine B15: 3, manufactured by Dainichi Seika) 45 parts by weight Ionic surfactant Neogen RK (Daiichi Kogyo Seiyaku Co., Ltd.) 5 parts by weight Ion-exchanged water 200 parts by weight Mixing and dissolving the above, homogenizer (IKA Ultra) For 10 minutes to obtain a cyan colorant dispersion having a center particle size of 168 nm.

(Preparation of release agent dispersion)
Polyalkylene wax (FNP0092, Nippon Seiwa Co., Ltd., melting point 91 ° C.) 45 parts by weight Cationic surfactant Neogen RK (Daiichi Kogyo Seiyaku Co., Ltd.) 5 parts by weight Ion-exchanged water 200 parts by weight After sufficiently dispersing with IKA Ultra Turrax T50, it was dispersed with a pressure discharge type gorin homogenizer to obtain a release agent dispersion having a volume average particle size of 190 nm and a solid content of 24.3% by weight.

(Preparation of resin particle dispersion)
(Oil layer)
Styrene (manufactured by Wako Pure Chemical Industries) 30 parts by weight n-butyl acrylate (manufactured by Wako Pure Chemical Industries) 10 parts by weight β-carboethyl acrylate (manufactured by Rhodia Nikka) 1.1 parts by weight Acrylic acid 0.2 parts by weight Dodecanethiol (Japanese) 0.4% by weight [Water layer 1]
Ion-exchanged water 17.0 parts by weight Anionic surfactant (manufactured by Rhodia) 0.39 parts by weight [aqueous layer 2]
Ion-exchanged water 40 parts by weight Anionic surfactant (manufactured by Rhodia) 0.06 parts by weight Potassium persulfate (manufactured by Wako Pure Chemical Industries) 0.30 parts by weight Ammonium persulfate (manufactured by Wako Pure Chemical Industries) 0.10 parts by weight The oil layer component and the water layer 1 component were placed in a flask and mixed with stirring to obtain a monomer emulsified dispersion. Furthermore, the components of the aqueous layer 2 were put into a reaction vessel, the inside of the vessel was sufficiently replaced with nitrogen, and the mixture was heated with an oil bath until the temperature in the reaction system reached 75 ° C. while stirring. The monomer emulsion dispersion was gradually dropped into the reaction vessel over 3 hours to carry out emulsion polymerization. Polymerization was further continued at 75 ° C. after completion of the dropwise addition, and the polymerization was terminated after 3 hours to obtain a resin particle dispersion 1. As a result, an anionic resin particle dispersion having a volume average particle diameter D50v = 200 nm, a solid content = 42%, a glass transition point = 51.5 ° C., and a weight average molecular weight (Mw) = 30000 was obtained.

(Preparation of inorganic particle dispersion)
As colloidal silica A, ST-OL (manufactured by Nissan Chemical Industries, volume average particle size of 40 nm) is used, and as colloidal silica B, ST-OS (manufactured by Nissan Chemical Industries, Ltd., volume average particle size of 8 nm) is each 2 parts by weight, Mix parts by weight appropriately, add 15 parts by weight of 0.02 mol / L HNO ₃ , add 0.3 parts by weight of polyaluminum chloride, and allow to stand at room temperature for 20 minutes to aggregate to obtain an inorganic particle dispersion. It was.

<Example 1>
(Manufacture of yellow toner 1)
Resin particle dispersion 80 parts by weight Yellow colorant dispersion 1 18 parts by weight Inorganic particle dispersion 30 parts by weight Release agent dispersion 18 parts by weight Polyaluminum chloride 0.36 parts by weight In a round stainless steel flask Thorough mixing and dispersion with Lux T50. Next, 0.36 parts by weight of polyaluminum chloride was added thereto, and the dispersion operation was continued with an ultra turrax. The flask was heated to 47 ° C. with stirring in an oil bath for heating. After maintaining at 47 ° C. for 60 minutes, 46 parts by weight of the resin particle dispersion was gently added thereto. Thereafter, the pH of the system is adjusted to 6.0 with a 0.5 mol / L sodium hydroxide aqueous solution, and then the stainless steel flask is sealed and heated to 96 ° C. while continuing stirring using a magnetic seal. Hold for 5 hours.

  After completion of the reaction, the mixture was cooled, filtered, sufficiently washed with ion exchange water, and then subjected to solid-liquid separation by Nutsche suction filtration. This was further redispersed in 3000 parts by weight of ion-exchanged water at 40 ° C., and stirred and washed at 300 rpm for 15 minutes. This was repeated five more times, and when the pH of the filtrate was 7.01, the electric conductivity was 9.7 μS / cm, and the surface tension was 71.2 Nm, solid-liquid separation was performed using No5A filter paper by Nutsche suction filtration. It was. Next, vacuum drying was continued for 12 hours to produce yellow toner 1.

When the volume average particle size at this time was measured with a Coulter counter, D50v was 6.0 μm, the volume average particle size distribution index GSDv was 1.25, and the number average particle size distribution index GSDp was 1.25. Further, the toluene insoluble content of the yellow toner 1 was 12.2% by weight. The abietic acid content and the surfactant content in the yellow toner 1 were measured by a method using respective calibration curves using a high performance liquid chromatography apparatus.
Measuring instrument: Shimadzu LC6A (manufactured by Shimadzu Corporation)
Column: CLC-ODS (manufactured by Shimadzu Corporation)
Detection wavelength: 290 nm
Mobile phase: Mixed solvent of methanol / tetrahydrofuran = 3/1 Mobile phase flow rate: about 1 mL / min
The composition ratio of the mixed compound of the present invention is defined by the area ratio of each component after composition separation by the liquid chromatography (area ratio in% display, total composition ratio 100%). When measured in this manner, the contents were 0.5% by weight of abietic acid and 0.4% by weight of surfactant.

(Manufacture of developer 1)
To 50 parts by weight of the prepared yellow toner 1, 1.0 part by weight of hydrophobic silica (TS720, manufactured by Cabot) and 2.0 parts by weight of hydrophobic silica (X24, manufactured by Shin-Etsu Chemical) are added, and the sample mill is used. Blended. This externally added yellow toner 1 is weighed so that the toner concentration is 5% with respect to a ferrite carrier having a volume average particle diameter of 50 μm coated with 1% of polymethyl methacrylate (manufactured by Soken Chemical Co., Ltd.), and stirred and mixed in a ball mill for 5 minutes. Then, yellow developer 1 was prepared.

(Manufacture of cyan toner and developer)
A cyan toner was manufactured in the same manner as yellow toner 1 except that a cyan colorant dispersion was used. When the volume average particle size at this time was measured with a Coulter counter, D50v was 6.0 μm, the volume average particle size distribution index GSDv was 1.24, and the number average particle size distribution index GSDp was 1.26. A cyan developer was prepared in the same manner as yellow toner 1.

(Toner evaluation)
The cyan developer and developer 1 are adjusted to a toner application amount of 5.0 g / m ² using a DoccentreColor400 remodeling machine (manufactured by Fuji Xerox Co., Ltd.), and secondary color is produced with mirror-coated platinum paper (manufactured by Fuji Xerox Co., Ltd.). After a certain green color was printed out, the image was fixed using an external fixing device at a fixing temperature of 180 ° C. and a fixing speed of 160 mm / sec under Nip 6.5 mm. Using a Gloss meter (Murakami Color Research Laboratory Co., Ltd., GM26D), the surface glossiness of the fixed image based on the 75 ° specular glossiness obtained from JIS P 8142: 93 was 80%.

It was confirmed that the fixing device had good releasability and that there was no gloss unevenness visually. Further, when the color gamut was measured, a ^* = 79 and b ^* = 30, and it was confirmed that the color reproducibility of the fixed image was excellent. Surface glossiness, fixing device peelability, and green were evaluated according to the following criteria.

(Surface gloss)
A: 76% or more B: 66% or more and less than 76% X: Less than 66% (fixing machine peelability)
◎: No problem ○: Degree of roughness is slightly observed in the image X: Obviously rough image is observed (Green evaluation)
A: a ^* > 78
○: a ^* = 78 to 75
X: a ^* <75
A: b ^* = 25-35
○: b ^* = 20-24 or 36-40
X: b ^* <20 or> 40

<Examples 2 to 10>
A yellow toner 2 to a yellow toner 10 and a yellow developer 2 to a yellow developer 10 were produced in the same manner as in Example 1 except that the yellow colorant dispersions 2 to 10 were used instead of the yellow colorant dispersion 1. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

<Comparative Examples 1-6>
A yellow toner 11 to a yellow toner 16 and a yellow developer 11 to a yellow developer 16 were produced in the same manner as in Example 1 except that the yellow colorant dispersions 11 to 16 were used instead of the yellow colorant dispersion 1. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

  As described above, it was confirmed that the toners of Examples 1 to 10 were excellent in surface glossiness and releasability of the fixing machine, and were peeled off with no gloss unevenness visually. Furthermore, when the color gamut was measured, it was also confirmed that the color reproducibility of the fixed image was excellent. On the other hand, it was confirmed that the color reproducibility of the fixed images of Comparative Examples 1 to 6 was insufficient.

(Adjustment of crystalline polyester resin for carrier coating)
In a heat-dried three-necked flask, 100% by weight of dimethyl sebacate and 100% by weight of ethylene glycol, and 0.3 parts by weight of dibutyltin oxide as a catalyst per 100 parts by weight of these in total, the air in the container was removed by decompression. Under an inert atmosphere with nitrogen gas, the mixture was stirred and refluxed at 180 ° C. for 5 hours with mechanical stirring. Thereafter, the temperature was gradually raised to 230 ° C. under reduced pressure, and the mixture was stirred for 2 hours. When it became viscous, it was cooled with air, the reaction was stopped, and a crystalline polyester resin was synthesized. The molecular weight was measured by gel permeation chromatography (polystyrene conversion), and the weight average molecular weight (Mw) of the obtained crystalline polyester resin was 9700. Further, when the melting point (Tm) of the crystalline polyester resin was measured using a differential scanning calorimeter (DSC) by the above-described measurement method, it showed a clear endothermic peak, and the endothermic peak temperature was 72.2 ° C. It was. The electrical resistance of the crystalline polyester resin obtained was 6.6 × 10 ¹¹ Ω · cm when an electric field of log E = 3.4 V / cm was applied in an environment where the relative humidity was 85%.

(Adjustment of amorphous polyester resin for carrier coating)
100 mol% terephthalic acid, 20 mol% isophthalic acid, 90 mol% bisphenol A propylene oxide 2-mol adduct, and 10 mol% ethylene glycol were placed in a 5 liter flask equipped with a stirrer, nitrogen inlet tube, temperature sensor, and rectifying column. The preparation took 1 hour and the temperature was raised to 190 ° C. After confirming that the reaction system was uniformly stirred, 1.2 parts by weight of dibutyltin oxide was added. Further, while distilling off the water produced, it took 6 hours from the same temperature to increase the temperature to 240 ° C., and continued the dehydration condensation reaction at 240 ° C. for another 5 hours. The acid value was 10.0 mg / KOH, and the weight average molecular weight. An amorphous polyester resin having 25000 and a glass transition temperature of 75.3 ° C. was obtained.

  The obtained crystalline polyester resin has an endothermic peak temperature TmA of 72.2 ° C. and an endothermic peak when the crystalline polyester resin and the amorphous polyester resin are mixed (TmAB, measured by the TmAB measurement method described above). Were 56.8 ° C. and TmA-TmAB = 15.4 ° C.

(Preparation of carrier A)
Ferrite particles (volume average particle size 35 μm) 100 parts by weight Ethyl acetate 14 parts by weight Crystalline polyester resin 0.33 parts by weight Amorphous polyester resin 1.32 parts by weight Carbon black (R330, manufactured by Cabot Corporation) 0.14 parts by weight Cross-linked melamine resin particles (volume average particle size 0.3 μm, ethyl acetate insoluble) 0.20 parts by weight A coating layer forming solution was prepared by dispersing all components except the ferrite particles among the above components with a sand mill. Next, the coating layer forming solution and the ferrite particles are put into a vacuum degassing type kneader, stirred at 60 ° C. for 30 minutes, further depressurized while warming, and dried to produce carrier A. did. The obtained carrier A was 3.4 × 10 ¹² Ω · cm when an electric field of log E = 3.8 V / cm was applied.

  The volume resistance values of the carrier and the crystalline polyester resin were measured using the apparatus shown in FIG. FIG. 1 is a configuration diagram for explaining the configuration of a volume resistance measuring device. In FIG. 1, the measurement sample 6 adjusted to the thickness H is sandwiched between the upper electrode 1 and the lower electrode 2, and the thickness is measured with the dial gauge 3 while being pressed by the pressurizing means 4 from above. The electrical resistance was measured with a high voltage ohmmeter 5 connected to the upper electrode 1 and the lower electrode 2 by wiring. The measurement sample 6 was sandwiched between the upper electrode 1 and the lower electrode 2 in the cell, and the thickness was measured with the dial gauge 3. Next, a predetermined voltage was applied, and the volume resistance value was obtained by reading the current value.

(Preparation of carrier B)
Ferrite particles (volume average particle size 35 μm) 100 parts by weight Ethyl acetate 14 parts by weight Amorphous polyester resin 1.66 parts by weight Carbon black (R330, manufactured by Cabot Corporation) 0.14 parts by weight Crosslinked melamine resin particles (volume average particle size) 0.3 μm, insoluble in ethyl acetate) 0.20 parts by weight A coating layer forming solution was prepared in which all components except the ferrite particles were dispersed by a sand mill. Next, this coating layer forming solution and ferrite particles are put into a vacuum degassing type kneader, stirred at 60 ° C. for 30 minutes, further depressurized while warming, and dried to produce carrier B. did. The obtained carrier B was 4.5 × 10 ¹⁴ Ω · cm when an electric field of log E = 3.8 V / cm was applied.

<Example 11>
Yellow developer 17 was obtained by stirring 8 parts by weight of externally added yellow toner 1 and 100 parts by weight of carrier A with a V-blender at 40 rpm for 20 minutes and sieving with a sieve having a 177 μm mesh. It was.

(Evaluation test)
Using the yellow developer 17 obtained in Example 11, using a modified machine of DocuPrint C2220 manufactured by Fuji Xerox Co., Ltd., the 100th sheet (initial stage) under each environment of normal temperature and normal humidity (22 ° C., 55% RH). Carrier adhesion and chargeability on the photoconductor, and then confirmation of carrier adhesion and chargeability when printing 30000 sheets at room temperature and normal humidity (22 ° C., 55% RH) were performed. The image forming method using the modified DocuPrint C2220 includes a step of forming an electrostatic latent image on an electrostatic charge image carrier and a toner image by developing the electrostatic latent image using a developer. A step, a step of transferring the toner image onto a transfer body, and a step of thermally fixing the toner image.

(Toner charge measurement)
The developer was taken out from the developing machine, and about 0.3 to 0.7 g of the developer was collected and measured by a blow-off method using a charge amount measuring device (TB200, manufactured by Toshiba Corporation).

(Carrier adhesion evaluation)
The developer was allowed to stand overnight under a predetermined temperature and humidity (38 ° C., 75% RH), and an image having two 2 cm × 5 cm patches was copied. Two background portions on the photosensitive member were transferred onto the tape using adhesiveness, the number of carriers per 1 cm ² was counted using a loupe or a microscope, and carrier adhesion was evaluated according to the following criteria. The distinction between toner and carrier was determined mainly by the difference in particle size and shape. The evaluation results are shown in Table 2.
◎: Less than 5 ○: 5 to 10 ×: 11 or more

<Example 12>
Evaluation was performed in the same manner as in Example 11 except that the yellow developer 1 of Example 1 was used instead of the yellow developer 17. The evaluation results are shown in Table 2.

<Comparative Example 7>
Evaluation was performed in the same manner as in Example 11 except that the yellow developer 16 of Comparative Example 6 was used instead of the yellow developer 17. The evaluation results are shown in Table 2.

As is apparent from Table 2, the developer of Example 11 has good chargeability even after printing 30000 sheets from the beginning, and there are few image quality defects due to carrier adhesion. Further, the green color using the developer of Example 12 was a ^* = 79, b ^* = 30, and an image with good color reproducibility was obtained. On the other hand, the green color using the developer of Comparative Example 7 was a ^* = 74, b ^* = 24, and an image with low color reproducibility was obtained.

<Example 13>
(Adjustment of developer (START developer) stored in advance in the developing machine)
9 parts by weight of externally added yellow toner 1 and 100 parts by weight of carrier A were mixed in a V-type blender to obtain yellow developer 18 as a START developer.

(Adjustment of developer for replenishment)
100 parts by weight of externally added yellow toner 1 and 15 parts by weight of carrier B were mixed with a V-type blender to obtain yellow developer 19 as a replenishing developer.

  Using the obtained START developer (yellow developer 18) and replenishment developer (yellow developer 19), the DocuCentreColor400 remodeling machine (manufactured by Fuji Xerox Co., Ltd.) was used for low temperature and low humidity (10 ° C., 20% RH). 50000 print test (image area: 5%) under the environment, and 150,000 print test (image area: 5%) under the environment of high temperature and high humidity (30 ° C, 85% RH) Confirmation of carrier adhesion and chargeability after 10 sheets (initial) and after 200000 sheets was carried out in the same manner as in Example 11. The evaluation results are shown in Table 3.

<Example 14>
Evaluation was performed in the same manner as in Example 13 except that the yellow developer 1 of Example 1 was used instead of the yellow developer 18 as the START developer. The evaluation results are shown in Table 3.

<Comparative Example 8>
Evaluation was performed in the same manner as in Example 13 except that the yellow developer 16 of Comparative Example 6 was used instead of the yellow developer 18 as the START developer. The evaluation results are shown in Table 3.

As is apparent from Table 3, the developer of Example 13 has good chargeability even after printing 200000 sheets from the beginning, and there are few image quality defects due to carrier adhesion. In addition, the green color using the developer of Example 14 was a ^* = 79 and b ^* = 30, and an image having good color reproducibility was obtained. On the other hand, the green color using the developer of Comparative Example 8 was a ^* = 74, b ^* = 24, and an image with low color reproducibility was obtained.

  As described above, the electrostatic charge image developing yellow toner containing the binder resin and the yellow colorant is stabilized by containing a predetermined amount of abietic acid and a surfactant having an HLB value of 4 or less. And good color reproducibility. In addition, by using the yellow toner for developing electrostatic images in combination with a resin-coated carrier coated with a resin including a crystalline polyester resin and an amorphous resin, long-term charge maintenance can be realized. It was.

It is the schematic which shows the structure of the volume resistance measuring device used in the Example of this invention.

Explanation of symbols

1 Upper electrode, 2 Lower electrode, 3 Dial gauge, 4 Pressurizing means, 5 High voltage resistance meter, 6 Measurement sample.

Claims (4)

A binder resin, a yellow colorant, abietic acid, and a surfactant having an HLB value of 4 or less,
The electrostatic image developing yellow characterized in that the content of the abietic acid in the toner is 0.2 to 1.2% by weight and the content of the surfactant is 0.04 to 1.0% by weight. toner. Mixing and dispersing a yellow colorant, abietic acid and a surfactant having an HLB value of 4 or less to obtain a colorant composition;
Dispersing the colorant composition in an aqueous solvent to obtain a colorant dispersion;
A step of agglomerating the resin particles, the colorant and the release agent in a dispersion obtained by mixing and dispersing the resin particle dispersion, the release agent dispersion and the colorant dispersion to form aggregated particles;
Heating and fusing the agglomerated particles;
A process for producing an electrostatic charge image developer yellow toner, comprising:   An electrostatic image developer comprising the yellow toner for developing an electrostatic image according to claim 1 and a carrier coated with a resin containing a crystalline polyester resin and an amorphous resin. A latent image forming step for forming an electrostatic latent image on the surface of the latent image holding member and a developer carried on the developer carrying member are used to develop the electrostatic latent image formed on the surface of the latent image holding member. A developing step for forming a toner image, a transfer step for transferring the toner image formed on the surface of the latent image holding member to the surface of the transfer target, and a fixing step for fixing the toner image transferred on the surface of the transfer target. An image forming method comprising:
The image forming method according to claim 3, wherein the developer is the electrostatic charge image developer according to claim 3.

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