JP4385876B2 - Toner for electrostatic charge development, method for producing toner for electrostatic charge development, developer for electrostatic charge development, and image forming method - Google Patents

Description

  The present invention relates to an electrostatic charge developing toner used when developing an electrostatic latent image formed by an electrophotographic method, an electrostatic recording method or the like with a developer, a method for producing an electrostatic charge developing toner, and an electrostatic charge developing development. The present invention relates to an agent and an image forming method.

  In electrophotography, an electrostatic charge 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 developing toner (hereinafter sometimes simply referred to as toner). It is visualized through a transfer and fixing process. As the developer, there are a two-component developer composed of a toner and a carrier, and a one-component developer using a magnetic toner or a non-magnetic toner alone. For the production of toner, a so-called kneading and pulverizing method is generally used in which a thermoplastic resin is melt-kneaded together with a pigment, a charge control agent and a release agent such as wax, cooled, finely pulverized, and further classified. Has been.

  In recent years, there has been a demand for higher image quality and higher process speed of an image formed by an image forming apparatus using electrophotography, and further energy saving in the production process is required from the viewpoint of environmental considerations. To meet the demands for higher image quality, toner particles are reduced. For high-speed processes, low-temperature fixability is studied. To cope with energy savings, production methods are actively studied. Became.

  However, the conventional toner obtained by the kneading and pulverizing method as described above has a limit in controlling the particle size of the toner, and the toner having an average particle size of 6 μm or less can be produced with a good yield and a narrow particle size distribution. Is difficult. Further, when charging a toner having a small particle diameter, the variation in charging is large, fogging occurs in the image formed by the image forming apparatus, or the toner is scattered when the image is formed. It was difficult to avoid defects such as dirt.

  On the other hand, in recent years, as a means capable of intentionally controlling the toner particle size and particle size distribution, electrophotographic toners by a wet manufacturing method such as a suspension granulation method, a suspension polymerization method, and an emulsion polymerization aggregation method can be used. Manufacturing methods have been proposed.

  By chemically creating toner particles by these methods, it is possible to provide small-sized toners with a volume average particle size of 6 μm or less, which was practically impossible with the conventional kneading and pulverization method, to the market at low cost. It became. In addition, in the conventional kneading and pulverizing method, the particle size distribution of the small particle size toner is wide, and the number of toner particles required per unit area is increased, so it is difficult to control the charging of the toner. Uniformity was achieved, and charge control could be facilitated. In view of such a situation, there is an increasing demand for higher image quality by a wet process small particle size toner.

  However, in these wet manufacturing methods, although the particle size controllability is excellent, the hydrophilicity of the binder resin composition having a polar group, and the surfactant used at the time of polymerization and dispersion of the colorant and the release agent are used. Due to the decrease in toner resistance due to the toner remaining in the toner, problems such as failure to obtain charge retention in a high-temperature and high-humidity environment and insufficient toner charge amount have occurred.

  Therefore, countermeasures such as reducing the amount of monomer having a polar group in the resin or reducing the amount of surfactant to be used are taken as countermeasures to a decrease in toner resistance and an unstable charge amount. ing.

JP-A-10-207120 JP-A-10-207125 JP 2004-126066 A

  However, if the amount of the monomer having a polar group is reduced in the resin or the amount of the surfactant to be used is reduced, the liquid viscosity rapidly rises in the aggregation process, which requires countermeasures. . In particular, in the emulsion polymerization aggregation method, an increase in dispersion viscosity is observed in the step of aggregating a dispersion obtained by mixing and dispersing emulsion polymerized binder resin fine particles, a colorant dispersion, and a release agent dispersion.

  In the emulsion polymerization aggregation method, by uniformly stirring the dispersion during aggregation, it is possible to control dispersibility of the colorant and the release agent well and to narrow the particle size distribution. However, since the above increase in viscosity occurs, it becomes difficult to stir, and measures have been taken to improve devices such as a stirring blade, but this has not been sufficient.

  In this way, in the step of aggregating the dispersion liquid in which the binder resin fine particles having acidic polar groups, the colorant dispersion liquid, the release agent dispersion liquid, etc. are agglomerated in the wet production method, particularly in the emulsion polymerization aggregation method, aggregation starts Occasionally an increase in the viscosity of the dispersion causes not only a deterioration in manufacturability, but also an increase in the adhesion of the reaction vessel wall due to a decrease in stirring efficiency, and coarse particles and irregular shapes due to the adhering matter in the vessel mixed into the toner. Toner quality deterioration such as an increase in particles, dispersibility deterioration of the colorant particles and release agent particles in the toner, a decrease in charge amount upon exposure to the toner surface, and deterioration in stability occurs. Therefore, it is necessary to suppress the occurrence of an increase in the viscosity of the dispersion at the start of aggregation.

  The present invention relates to a toner for developing an electrostatic charge, a method for producing a toner for developing an electrostatic charge, a developer for developing an electrostatic charge, and an image forming method.

The present invention relates to an electrostatic charge developing toner comprising a binder resin having an acidic polar group, a colorant, and a release agent, and obtained by agglomerating resin fine particles containing the binder resin, wherein the toner is in the range of the weight-average molecular weight Mw of 500 to 3000, styrene is acid value in the range of 150~600mgKOH / g - include maleic acid copolymer, said styrene in said toner - maleic acid copolymer The content of is from 0.01% by weight to 0.5% by weight.

The present invention also relates to a method for producing a toner for developing an electrostatic charge, comprising a binder resin having an acidic polar group, a colorant, and a release agent, and obtained by agglomerating resin fine particles containing the binder resin. In the step of aggregating the resin fine particles, a styrene-maleic acid copolymer having a weight average molecular weight Mw in the range of 500 to 3000 and an acid value in the range of 150 to 600 mgKOH / g is used. The content of the styrene-maleic acid copolymer in the toner is 0.01% by weight or more and 0.5% by weight or less.

  The present invention also provides an electrostatic charge developing developer comprising the electrostatic charge developing toner.

  Furthermore, the present invention is an image forming method using the toner for developing an electrostatic charge.

  By using a specific carboxylic acid group-containing compound at the time of toner production according to the present invention, not only the particle size and particle size distribution control is excellent, but also a colorant, a release agent and the like are uniformly dispersed, and chargeability is improved. An excellent toner can be obtained.

  Embodiments of the present invention will be described below.

  An electrostatic charge developing toner according to an embodiment of the present invention includes a binder resin having an acidic polar group, a colorant, and a release agent, and is obtained by aggregating resin fine particles containing the binder resin. A toner for development, wherein the toner includes a carboxylic acid group-containing compound having a weight average molecular weight Mw in the range of 500 to 3000 and an acid value in the range of 150 to 600 mgKOH / g, The content of the containing compound is 0.01% by weight or more and 0.5% by weight or less.

  In this embodiment, the electrostatic charge developing toner is a toner produced by a wet method and obtained by agglomerating resin fine particles containing a binder resin. In this aggregating step, the weight average molecular weight Mw is in the range of 500 to 3000. It is preferable to use a carboxylic acid group-containing compound having an acid value in the range of 150 to 600 mgKOH / g.

  The toner according to the exemplary embodiment is preferably manufactured by a wet method. The emulsion polymerization aggregation method, in which the binder resin is produced by emulsion polymerization, heteroaggregated with a dispersion of colorant, release agent, etc., and then fused and united, toner particle size controllability, narrow particle size distribution, shape controllability However, it is more preferable from the viewpoint of excellent narrow shape distribution, internal dispersion controllability, and the like, but other wet manufacturing methods are not limited to these as long as they include an agglomeration step.

  When the electrostatic image developing toner in the present embodiment is performed by a heteroaggregation method such as an emulsion aggregation method, a resin fine particle dispersion containing a binder resin having an acidic polar group, a colorant dispersion, a release agent dispersion, It is preferable to mix the carboxylic acid group-containing compound with the inorganic fine particle dispersion or the like.

  The inventors of the present invention can uniformly agitate the dispersion in the agitation tank during toner production by a wet method and control the aggregation rate, so that the particle size distribution is narrow and additives such as a colorant and a release agent are uniform. It was found to be an important factor for obtaining a toner of good quality dispersed in the toner.

  In the present embodiment, the carboxylic acid group-containing compound can change the time required for aggregation, the state of the dispersion system, and the like in the aggregation process. Therefore, the viscosity at the time of aggregation of the dispersion can be controlled to improve productivity. In addition, toner quality such as particle size distribution, shape distribution, and charging property can be kept good.

  The carboxylic acid group-containing compound used in the present embodiment is not particularly limited as long as the weight average molecular weight Mw is in the range of 500 to 3000 and the acid value is in the range of 150 to 600 mgKOH / g.

  Examples of the carboxylic acid group-containing compound include oligomers or copolymer resins of monomers having a carboxylic acid group, and salts thereof. Examples of the monomer having a carboxylic acid group include α, β-ethylenically unsaturated compounds having a carboxylic acid group. Examples of the α, β-ethylenically unsaturated compound having a carboxylic acid group include acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, cinnamic acid, monomethyl maleate, monobutyl maleate, malein And acid monooctyl ester. Examples of copolymer resins with monomers having a carboxylic acid group include styrene-acrylic acid copolymer resins, styrene-acrylic acid ester-acrylic acid copolymer resins, α-methylstyrene-acrylic acid copolymer resins, and styrene. -Maleic acid copolymer resins and their salts. Moreover, a part of those copolymer resins may be esterified. Furthermore, what is used as an anionic surfactant can also be used if conditions meet.

  The weight average molecular weight Mw of the carboxylic acid group-containing compound is in the range of 500 to 3000, preferably in the range of 500 to 2000, and more preferably in the range of 1000 to 1500. If the weight average molecular weight Mw is less than 500, it is difficult to affect the aggregation, and if it is more than 3000, there is a possibility of promoting the viscosity increase of the dispersion system depending on the aggregation conditions.

  Moreover, although the acid value of a carboxylic acid group containing compound exists in the range of 150-600 mgKOH / g, it is preferable to exist in the range of 300-550 mgKOH / g, and it is more preferable to exist in the range of 400-550 mgKOH / g. If the acid value is less than 150 mgKOH / g, the aggregation is hardly affected, and if it is more than 600 mgKOH / g, the aggregation may be inhibited.

  The compounding amount of the carboxylic acid group-containing compound needs to be adjusted according to the solid content concentration of the dispersion system during production, the amount of polar groups in the binder resin, etc. It is preferably in the range of 0.05 to 5.0% by weight. If the amount is less than 0.05% by weight, a sufficient effect cannot be obtained. If the amount is more than 5.0% by weight, aggregation may be inhibited.

  Further, the content of the carboxylic acid group-containing compound in the toner is 0.01% by weight or more and 0.5% by weight or less, preferably 0.01% by weight or more and 0.3% by weight or less. More preferably, the content is 0.01% by weight or more and 0.1% by weight or less. If it is more than 0.5% by weight, it may cause a decrease in charge under high temperature and high humidity.

  The electrostatic image developing toner according to the exemplary embodiment will be described in detail together with a preferable manufacturing method thereof. In the present embodiment, as a toner production method, a resin fine particle dispersion containing a binder resin is prepared by emulsion polymerization or other methods, and hetero-aggregated with a dispersion of a colorant, a release agent, etc. An emulsion polymerization aggregation method is preferred. The emulsion polymerization aggregation method is a step of mixing a resin fine particle dispersion in which binder resin particles having a particle size of 1 μm or less are dispersed and a colorant dispersion in which a colorant is dispersed (hereinafter referred to as “dispersion step”). ), A step of aggregating the binder resin fine particles, colorant, etc. into the toner particle diameter (hereinafter sometimes referred to as “aggregation step”), heating to a temperature above the glass transition point of the resin fine particles, and fusing the aggregate to the toner A step of forming particles (hereinafter sometimes referred to as a “fusion step”). Hereinafter, the emulsion polymerization aggregation method will be described as an example.

  The carboxylic acid group-containing compound used in the present embodiment may be present in the dispersion during the aggregation process, and the addition time may be determined according to the type of binder resin used. The carboxylic acid group-containing compound is preferably added before the start of the aggregation process, and more preferably added immediately before the start of the dispersion process or just before the start of the aggregation process.

  The carboxylic acid group-containing compound may be added as it is, may be added as a suspension solution in a solvent such as water, or may be added as a solution such as an aqueous solution. It may be added according to. In the case of a solid material such as a resin, it is preferably added as a solution obtained by neutralizing and dissolving in a basic aqueous solution.

  The method for adding the carboxylic acid group-containing compound is not particularly limited as long as the total amount of the carboxylic acid group-containing compound is added before the start of the aggregation step, preferably at the time of the aggregation step. Alternatively, it may be gradually added continuously, or it may be divided into a plurality of times and added stepwise.

  In the aggregation step, the binder resin fine particle dispersion, the colorant dispersion, and, if necessary, the particles in the release agent dispersion mixed in the dispersion step aggregate to form aggregated particles. The agglomerated particles are formed by heteroaggregation or the like. Generally, an ionic surfactant having a polarity different from that of the agglomerated particles, a pH adjuster, a compound having a monovalent or higher charge such as a metal salt is added and necessary. Accordingly, the temperature is increased while controlling the pH, and the particles are aggregated to the target particle size.

  As described above, in this aggregation step, when the binder resin fine particles contain an acidic polar group, particularly when a carboxylic acid group is contained, the viscosity of the dispersion system increases at the start of aggregation, and as the aggregation proceeds, the viscosity once After reaching the maximum value, the viscosity is lowered, and the viscosity is reduced to the viscosity of the first dispersion or lower. This viscosity change occurs more rapidly as the amount of acidic polar groups in the resin particles and the amount of the surfactant contained in the colorant dispersion and the release agent dispersion are smaller.

  When the above viscosity change occurs, the stirring efficiency is usually improved by optimizing the stirring speed, changing the shape of the stirring blade, and additionally installing a circulating disperser in order to increase the stirring efficiency in the stirring tank. Adjustment is made so that the viscosity does not decrease, but if the viscosity change suddenly occurs, the control is not sufficient, and the vicinity of the liquid surface of the tank wall cannot be stirred, and dispersion of the colorant or the like in the toner does not occur at the end of aggregation. Problems such as becoming uniform occur. In addition, the air in the tank or the substituted gas is entrained in the dispersion due to the increase in viscosity, and bubbles are generated, and the bulk density of the dispersion changes before and after the aggregation. Due to this change in bulk density, the dispersion liquid adheres to the inner wall of the tank or the stirrer, and when this deposit peels off and enters the dispersion liquid, it remains as a coarse powder or becomes a particle with a different shape. Occurs.

  In the present embodiment, such a sudden change in viscosity can be suppressed by adding the carboxylic acid group-containing compound. Furthermore, the aggregation rate can be controlled by adjusting the amount of the carboxylic acid group-containing compound added, so that the colorant-dispersed particles and the release agent-dispersed particles can be prevented from remaining as aggregated particles at the end of the aggregation process.

  By using the carboxylic acid group-containing compound in this way, the particle size controllability is excellent, the irregular shape and coarse particles are less mixed, and the colorant fine particles and release agent fine particles are well dispersed and exposed to the toner surface. Therefore, toner particles having a stable charge amount can be produced.

  In the fusion process after the aggregation process, the binder resin fine particles in the aggregated particles melt at a temperature condition equal to or higher than the glass transition temperature of the binder resin, and the aggregated particles gradually change from an indeterminate shape to a spherical shape. go. At this time, the shape of the agglomerated particles is indefinite, but it becomes closer to a sphere due to coalescence. When the toner has a desired shape, the heating of the toner is stopped and the toner particles are formed by cooling.

  Further, between the agglomeration step and the fusion step, a step of forming adhering particles by adding a fine particle dispersion in which fine particles are dispersed to the agglomerated particle dispersion and adhering the fine particles to the agglomerated particles (adhesion) Step) can also be provided.

  In the attaching step, the fine particle dispersion is added to and mixed with the aggregated particle dispersion prepared in the aggregation step, and the fine particles are attached to the aggregated particles to form the attached particles. The added fine particles correspond to particles newly added to the aggregated particles as viewed from the aggregated particles, and therefore may be referred to as “additional fine particles” in this specification. As the additional fine particles, in addition to resin fine particles, release agent fine particles, colorant fine particles and the like may be used singly or in combination. The method for additionally mixing the additional fine particle dispersion is not particularly limited. For example, the additional fine particle dispersion may be gradually and continuously performed, or may be divided into a plurality of times and performed stepwise. Thus, by adding and mixing the additional fine particles, generation of fine particles can be suppressed, and the particle size distribution of the obtained toner for developing an electrostatic image can be sharpened, which contributes to high image quality.

  In addition, by providing an adhesion process, a pseudo shell structure can be formed, and the toner surface exposure of internal additives such as colorants and release agents can be reduced, resulting in improved chargeability and carrier life. In addition, it is possible to maintain the particle size distribution during fusion in the fusion process, to suppress fluctuations, and to improve the stability at the time of fusion, such as surfactants and stabilizers such as bases or acids. This is advantageous in that the addition can be made unnecessary and the amount of addition can be suppressed to the minimum, and the cost can be reduced and the quality can be improved. Furthermore, if this method is used, the toner shape can be easily controlled by adjusting the temperature, the number of stirring, the pH, and the like in the fusing step.

  Examples of the resin (binder resin) used in the resin fine particle dispersion include a thermoplastic resin, and specifically, a single weight of styrene such as styrene, parachlorostyrene, α-methylstyrene and the like. Copolymer or copolymer (styrene resin); methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, methacryl Homopolymers or copolymers of vinyl groups such as n-propyl acid, lauryl methacrylate, 2-ethylhexyl methacrylate, etc .; vinyl nitriles such as acrylonitrile and methacrylonitrile Or copolymer (vinyl resin); vinyl ethyl ether, vinyl Vinyl ether homopolymers or copolymers (vinyl resins) such as butyl ether; vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone homopolymers or copolymers (vinyl resins); ethylene, propylene, butadiene, Homopolymers or copolymers of olefins such as isoprene (olefin resins); non-vinyl condensation resins such as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and these non-vinyl condensations And a graft polymer of a vinyl resin and a vinyl monomer. These resins may be used alone or in combination of two or more.

  In the present embodiment, an acidic polar group must be present in the binder resin, and examples of the acidic polar group include a carboxylic acid group, a sulfone group, a phosphoric acid group, and a formyl group. However, it is preferable from the viewpoint of good aggregation controllability and charging characteristics.

  The acidic polar group is obtained by copolymerization of a monomer having an acidic polar group; low-molecular condensation polymerization or addition polymerization having an acidic polar group; a method of introducing an acidic polar group into a polymer by reaction; Examples of the monomer having an acidic polar group include an α, β-ethylenically unsaturated compound having a carboxyl group, an α, β-ethylenically unsaturated compound having a sulfone group, and the like. Examples of the α, β-ethylenically unsaturated compound having a carboxyl group include acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, cinnamic acid, monomethyl maleate, monobutyl maleate, and maleic acid. A monooctyl ester etc. are mentioned. Examples of the α, β-ethylenically unsaturated compound having a sulfone group include sulfonated ethylene, a salt thereof, allylsulfosuccinic acid, octyl allylsulfosuccinate, and the like.

  Low molecules having a carboxyl group as an acidic polar group used in the condensation polymerization or addition polymerization include terephthalic acid, isophthalic acid, phthalic anhydride, benzene-1,2,4-tricarboxylic acid, benzene-1, Aromatic dicarboxylic acids such as 2,5-tricarboxylic acid, naphthalene-2,5,7-tricarboxylic acid, naphthalene-1,2,4-tricarboxylic acid; oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, Hexahydrophthalic anhydride, itaconic acid, maleic acid, fumaric acid, mesaconic acid, citraconic acid, 1,2,4-butanetricarboxylic acid, hexane-1,2,5-tricarboxylic acid, 1,3-dicarboxy-2- Carboxymethylpropene, 1,3-dicarboxy-2-methyl-2-carboxymethylpropane, tetra (carboxy Til) aliphatic carboxylic acids such as methane, octane-1,2,7,8-tetracarboxylic acid, maleic anhydride; tetrahydrophthalic acid, hexahydrophthalic acid, methyltetrahydrophthalic acid, methylhexahydrophthalic acid, methylhigh Examples thereof include alicyclic carboxylic acids such as mimic acid, trialkyltetrahydrophthalic acid, and methylcyclohexene dicarboxylic acid, and anhydrides thereof.

  Among these resins, vinyl resins are particularly preferable. In the case of a vinyl resin, it is advantageous in that a resin dispersion can be easily prepared by emulsion polymerization or seed polymerization using an ionic surfactant.

  A cross-linking agent can be added to the binder resin in the present embodiment as necessary.

  Specific examples of such a crosslinking agent include, for example, aromatic polyvinyl compounds such as divinylbenzene and divinylnaphthalene; divinyl phthalate, divinyl isophthalate, divinyl terephthalate, divinyl homophthalate, divinyl trimesate / trivinyl, Polyvinyl esters of aromatic polycarboxylic acids such as divinyl naphthalenedicarboxylate and divinyl biphenylcarboxylate; divinyl esters of nitrogen-containing aromatic compounds such as divinyl pyridinedicarboxylate; vinyl pyromutate, vinyl furancarboxylate, pyrrole Vinyl esters of unsaturated heterocyclic compounds such as vinyl 2-carboxylate and vinyl thiophene carboxylate; butanediol methacrylate, hexanediol acrylate, octanediol methacrylate, decandioldiol (Meth) acrylic acid esters of linear polyhydric alcohols such as relate and dodecanediol methacrylate; branches such as neopentylglycol dimethacrylate and 2-hydroxy-1,3-diaacryloxypropane; (Meth) acrylates; polyethylene glycol di (meth) acrylate, polypropylene polyethylene glycol di (meth) acrylates; divinyl succinate, divinyl fumarate, vinyl / divinyl maleate, divinyl diglycolate, vinyl itaconate / divinyl, Divinyl acetone dicarboxylate, divinyl glutarate, divinyl 3,3′-thiodipropionate, trans-aconitic divinyl / trivinyl, divinyl adipate, divinyl pimelate, divinyl suberate, azelain And polyvinyl esters of polyvalent carboxylic acids such as divinyl acid, divinyl sebacate, divinyl dodecanedioate, and divinyl brassylate.

  In this embodiment, these crosslinking agents may be used alone or in combination of two or more. Of the above crosslinking agents, butanediol methacrylate, hexanediol acrylate, and octane can suppress the precipitation of the release agent on the toner surface during cooling in order not to make the binder resin unnecessarily high in the coalesced state. (Meth) acrylic acid esters of linear polyhydric alcohols such as diol methacrylate, decane diol acrylate, and dodecane diol methacrylate; branching and substitution such as neopentyl glycol dimethacrylate and 2-hydroxy-1,3-diacryloxypropane It is preferable to use (meth) acrylic acid esters of polyhydric alcohols; polyethylene glycol di (meth) acrylate, polypropylene polyethylene glycol di (meth) acrylate, and the like.

  The content of the crosslinking agent is preferably in the range of 0.05 to 5% by weight of the total amount of polymerizable monomers used for forming the binder resin, and in the range of 0.1 to 1.0% by weight. More preferably.

  The binder resin used for the toner in this embodiment can be produced by radical polymerization of the polymerizable monomer.

  There is no restriction | limiting in particular as an initiator for radical polymerization used here. Specifically, for example, hydrogen peroxide, acetyl peroxide, cumyl peroxide, tert-butyl peroxide, propionyl peroxide, benzoyl peroxide, chlorobenzoyl peroxide, dichlorobenzoyl peroxide, bromomethylbenzoyl peroxide, Lauroyl oxide, ammonium persulfate, sodium persulfate, potassium persulfate, diisopropyl peroxycarbonate, tetralin hydroperoxide, 1-phenyl-2-methylpropyl-1-hydroperoxide, pertriphenylacetic acid tert-butyl hydroperoxide, formic acid tert- Peroxides such as butyl, tert-butyl peracetate, tert-butyl perbenzoate, tert-butyl perphenylacetate, tert-butyl permethoxyacetate, tert-butyl perN- (3-toluyl) carbamate; 2 , 2'-azo Supropane, 2,2′-dichloro-2,2′-azobispropane, 1,1′-azo (methylethyl) diacetate, 2,2′-azobis (2-amidinopropane) hydrochloride, 2,2 ′ -Azobis (2-amidinopropane) nitrate, 2,2'-azobisisobutane, 2,2'-azobisisobutyramide, 2,2'-azobisisobutyronitrile, 2,2'-azobis-2- Methyl methylpropionate, 2,2′-dichloro-2,2′-azobisbutane, 2,2′-azobis-2-methylbutyronitrile, dimethyl 2,2′-azobisisobutyrate, 1,1′-azobis (1 -Sodium methylbutyronitrile-3-sulfonate), 2- (4-methylphenylazo) -2-methylmalonodinitrile, 4,4'-azobis-4-cyanovaleric acid, 3,5-dihydroxymethylphenol Enylazo-2-methylmalonodinitrile, 2- (4-bromophenylazo) -2-allylmalonodinitrile, 2,2'-azobis-2-methylvaleronitrile, 4,4'-azobis-4-cyano Dimethyl herbate, 2,2′-azobis-2,4-dimethylvaleronitrile, 1,1′-azobiscyclohexanenitrile, 2,2′-azobis-2-propylbutyronitrile, 1,1′-azobis-1 -Chlorophenylethane, 1,1'-azobis-1-cyclohexanecarbonitrile, 1,1'-azobis-1-cycloheptanenitrile, 1,1'-azobis-1-phenylethane, 1,1'-azobiscumene, 4-Nitrophenylazobenzylcyanoacetate ethyl, phenylazodiphenylmethane, phenylazotriphenylmethane, 4-nitrophenylazo Triphenylmethane, 1,1′-azobis-1,2-diphenylethane, poly (bisphenol A-4,4′-azobis-4-cyanopentanoate), poly (tetraethylene glycol-2,2′-azo Azo compounds such as bisisobutyrate; 1,4-bis (pentaethylene) -2-tetrazene, 1,4-dimethoxycarbonyl-1,4-diphenyl-2-tetrazene and the like.

  Adjustment of the molecular weight of the binder resin used in the toner according to the exemplary embodiment can be performed using a chain transfer agent. The chain transfer agent is not particularly limited, and specifically has a covalent bond between a carbon atom and a sulfur atom, and more specifically, n-propyl mercaptan, n-butyl mercaptan, n-amyl. N-alkyl mercaptans such as mercaptan, n-hexyl mercaptan, n-heptyl mercaptan, n-octyl mercaptan, n-nonyl mercaptan, n-decyl mercaptan; isopropyl mercaptan, isobutyl mercaptan, s-butyl mercaptan, tert-butyl mercaptan, Chain-chain alkyl mercaptans such as cyclohexyl mercaptan, tert-hexadecyl mercaptan, tert-lauryl mercaptan, tert-nonyl mercaptan, tert-octyl mercaptan, tert-tetradecyl mercaptan S; allyl mercaptan, 3-phenylpropyl mercaptan, phenyl mercaptan, mercaptans 含芳 incense ring system such as mercapto triphenylmethane; and the like.

  In the toner according to the exemplary embodiment, it is preferable to use a surfactant such as an anionic surfactant, a cationic surfactant, or a nonionic surfactant as a dispersant. Among these, it is more preferable to use an anionic surfactant because of its strong dispersion power and excellent dispersion of binder resin fine particles, colorants and the like.

  The nonionic surfactant is preferably used in combination with the anionic surfactant or the cationic surfactant. The said surfactant may be used individually by 1 type, and may be used in combination of 2 or more type.

  Specific examples of anionic surfactants include fatty acid soaps such as potassium laurate, sodium oleate, and castor oil sodium; sulfates such as octyl sulfate, lauryl sulfate, lauryl ether sulfate, and nonyl phenyl ether sulfate; lauryl sulfonate , Sodium alkylnaphthalene sulfonate such as dodecylbenzene sulfonate, triisopropyl naphthalene sulfonate, dibutyl naphthalene sulfonate; sulfone such as naphthalene sulfonate formalin condensate, monooctyl sulfosuccinate, dioctyl sulfosuccinate, lauric acid amide sulfonate, oleic acid amide sulfonate Acid salts; lauryl phosphate, isopropyl phosphate, nonylphenyl ether Phosphoric acid esters such as Sufeto; dialkyl sulfosuccinate salts such as sodium dioctyl sulfosuccinate; sulfosuccinate salts such as sulfosuccinate lauryl disodium; and the like.

  Specific examples of the cationic surfactant include laurylamine hydrochloride, stearylamine hydrochloride, oleylamine acetate, stearylamine acetate, stearylaminopropylamine acetate, and other amine salts; lauryltrimethylammonium chloride, dilauryldimethylammonium Chloride, distearyldimethylammonium chloride, distearyldimethylammonium chloride, lauryldihydroxyethylmethylammonium chloride, oleylbispolyoxyethylenemethylammonium chloride, lauroylaminopropyldimethylethylammonium ethosulphate, lauroylaminopropyldimethylhydroxyethylammonium perchlorate, alkylbenzene Trimethylammonium chloride, Quaternary ammonium salts such as quilts trimethyl ammonium chloride; and the like.

  Specific examples of the nonionic surfactant include alkyl ethers such as polyoxyethylene octyl ether, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether; polyoxyethylene octyl phenyl ether, polyoxy Alkyl phenyl ethers such as ethylene nonyl phenyl ether; alkyl esters such as polyoxyethylene laurate, polyoxyethylene stearate, polyoxyethylene oleate; polyoxyethylene lauryl amino ether, polyoxyethylene stearyl amino ether, polyoxyethylene Alkylamines such as oleyl amino ether, polyoxyethylene soybean amino ether, polyoxyethylene beef tallow amino ether; Alkyl amides such as ethylene lauric acid amide, polyoxyethylene stearic acid amide, polyoxyethylene oleic acid amide; vegetable oil ethers such as polyoxyethylene castor oil ether and polyoxyethylene rapeseed oil ether; lauric acid diethanolamide, stearic acid Alkanolamides such as diethanolamide and oleic acid diethanolamide; sorbitan ester ethers such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate And so on.

  The content of the surfactant in each dispersion is generally a small amount, specifically, preferably in the range of about 0.01 to 10% by weight, and 0.05 to 5% by weight. More preferably, it is in the range of about 0.1 to 2% by weight. When the content is less than 0.01% by weight, dispersion of each dispersion liquid such as a binder resin fine particle dispersion, a colorant dispersion, and a release agent dispersion becomes unstable, which causes aggregation. Since the stability of each particle differs during aggregation, there are problems such as the release of specific particles. When the amount exceeds 10% by weight, the particle size distribution of the particles becomes wide and the particle size is difficult to control. It is not preferable for reasons such as.

  Further, a room temperature solid aqueous polymer or the like can also be used as the surfactant. Specifically, cellulose compounds such as carboxymethyl cellulose and hydroxypropyl cellulose, polyvinyl alcohol, gelatin, starch, gum arabic and the like can be used.

  The glass transition point of the binder resin used in the present embodiment is preferably in the range of 40 ° C. to 70 ° C., and more preferably in the range of 45 ° C. to 60 ° C. If the glass transition point is lower than 40 ° C., the toner powder is likely to be blocked by heat, and if it is 70 ° C. or higher, the fixing temperature may be too high.

  In addition, the binder resin preferably has a weight average molecular weight Mw in the range of 6000 to 45000, more preferably in the range of 6000 to 10,000 when the binder resin is a polyester resin, and a vinyl resin. Is more preferably in the range of 24,000 to 36000.

  When the weight average molecular weight Mw is larger than 45000, the viscoelasticity at the time of fixing is high, and it is difficult to obtain a smooth fixed image surface necessary for high gloss. When the weight average molecular weight Mw is smaller than 6000, the toner melts at the fixing step. Hot offset occurs due to low viscosity and poor cohesion. Further, when the binder resin is a polyester resin, when the mass average molecular weight Mw exceeds 10,000, it is difficult to disperse in the aqueous medium.

  The ratio (Mw / Mn) between the weight average molecular weight Mw and the number average molecular weight Mn of the binder resin is preferably 3.3 or less, and more preferably 2.8 or less. In order to speed up the transfer of the release agent to the fixed image surface and to obtain a smooth fixed image surface, it is advantageous to have an appropriate low viscosity, and the molecular weight distribution of the binder resin is narrow. Is preferred. When Mw / Mn is larger than 3.3, it becomes difficult to obtain a smooth fixed image surface necessary for high gloss.

  The average particle diameter of the binder resin fine particles in the binder resin fine particle dispersion is preferably 1 μm or less, and more preferably in the range of 0.01 to 1 μm. If the average particle size exceeds 1 μm, the particle size distribution of toner particles obtained by agglomeration and fusion is widened, and free particles are generated, which tends to cause a decrease in toner performance and reliability. In the exemplary embodiment, by adjusting the average particle diameter in the above range, the dispersion of the binder resin fine particles in the aggregated particles can be improved, and the uneven distribution of the composition among the toner particles can be suppressed. There is an advantage that variations in performance and reliability can be kept low. The average particle diameter can be measured with, for example, a laser diffraction particle size distribution measuring machine or a coulter counter.

  Examples of the colorant used in the toner in the present embodiment include carbon black, chrome yellow, hansa yellow, benzidine yellow, sren yellow, quinoline yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, and brilliant. Carmine 3B, Brilliant Carmine 6B, Dupont Oil Red, Pyrazolone Red, Risor Red, Rhodamine B Lake, Lake Red C, Rose Bengal, Aniline Blue, Ultramarine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Phthalocyanine Green, Maracalite Various pigments such as green oxalate: acridine, xanthene, azo, benzoquinone, a , Anthraquinone, dioxazine, thiazine, azomethine, indico, thioindico, phthalocyanine, aniline black, polymethine, triphenylmethane, diphenylmethane, thiazole, xanthene, etc. Can be mentioned. These colorants may be used alone or in combination of two or more.

  The average particle diameter of the colorant particles using the colorant is preferably 1 μm or less, more preferably 0.5 μm or less, and further preferably in the range of 0.01 μm to 0.5 μm. When the average particle diameter exceeds 1 μm, the particle size distribution of the finally obtained electrostatic charge developing toner becomes wide, or free particles are likely to be generated, and the performance and reliability of the toner are likely to be lowered.

  By adjusting the average particle size within the above range, the dispersion of the colorant in the agglomerated particles can be improved, the uneven distribution of the composition among the toner particles can be suppressed, and the variation in toner performance and reliability can be suppressed low. There is an advantage that you can. By setting the average particle size to 0.5 μm or less, the color development property, color reproducibility, OHP permeability, etc. of the toner can be further improved.

  In addition, the said average particle diameter can be measured using a laser diffraction type particle size distribution measuring machine etc., for example.

  The colorant content in the aggregated particles is preferably 50% by weight or less, and more preferably in the range of 2 to 20% by weight.

  In general, the release agent used for the toner in the present embodiment is preferably one having poor compatibility with the binder resin of the toner. When a release agent that is highly compatible with the binder resin is used, the release agent melts into the binder resin and promotes plasticization of the binder resin, thereby reducing the viscosity of the toner during high-temperature fixing, and offset is likely to occur. .

  Specific examples of the release agent include low molecular weight polyolefins such as polyethylene, polypropylene, and polybutene; silicones that exhibit a softening point upon heating; fatty acid amides such as oleic acid amide, erucic acid amide, ricinoleic acid amide, and stearic acid amide. Plant waxes such as carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil; animal waxes such as beeswax; minerals such as montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, and Fischer-Tropsch wax -Petroleum wax; ester waxes of higher fatty acids such as stearyl stearate and behenyl behenate and higher alcohols; butyl stearate, propyl oleate, glyceryl monostearate, distearic acid Ester waxes of higher fatty acids such as riseride and pentaerythritol tetrabehenate and unit or polyhydric lower alcohols; higher fatty acids such as diethylene glycol monostearate, dipropylene glycol distearate, distearic acid diglyceride, tetrastearic acid triglyceride Examples include ester waxes composed of polyhydric alcohol multimers; sorbitan higher fatty acid ester waxes such as sorbitan monostearate; and cholesterol higher fatty acid ester waxes such as cholesteryl stearate. The crystallinity of the release agent can be determined by X-ray analysis.

  The amount of the release agent in the toner is preferably in the range of 6 to 25% by weight, and more preferably in the range of 9 to 20% by weight. If the amount of the release agent is less than 6% by weight, since the absolute amount of the release agent is insufficient, a so-called document offset occurs in which the fixed image is transferred to the opposite sheet or image by heat or pressure. If the amount exceeds 25% by weight, the viscoelasticity of the toner that melts during fixing is extremely reduced, and hot offset occurs. In the case of OHP, the release agent does not penetrate, so that the release agent adheres to the fixing roll and fixing. Even after the second rotation of the roll, a phenomenon called a wax offset in which a release agent trace remains in the OHP occurs.

  The average particle size of the release agent particles in the dispersion using the release agent is preferably 1.5 μm or less, and more preferably in the range of 0.1 μm to 1.0 μm. When the average particle diameter exceeds 1.5 μm, the domain diameter of the release agent in the finally obtained electrostatic charge developing toner becomes large or free particles are likely to be generated, resulting in a decrease in toner performance and reliability. It is easy to invite.

  In the present embodiment, in addition to the above binder resin fine particle dispersion, colorant dispersion, release agent dispersion, etc., as required, internal additives, charge control agents, inorganic fine particles, organic fine particles, lubricants It is possible to add fine particles such as abrasives. For the addition method, the fine particles may be dispersed in a binder resin fine particle dispersion, a colorant dispersion, or a release agent dispersion, or a binder resin fine particle dispersion, a colorant dispersion, or a release agent dispersion. A dispersion obtained by dispersing the fine particles may be added to and mixed with a mixture obtained by mixing the above.

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

  As the inorganic fine particles, for example, external toner surface additives such as silica, titania, calcium carbonate, magnesium carbonate, tricalcium phosphate, and cerium oxide can be used.

  In addition, as the organic fine particles, for example, an external additive on the surface of a normal toner such as a vinyl resin, a polyester resin, or a silicone resin can be used. These inorganic fine particles and organic fine particles can be used as fluidity aids and cleaning aids.

  Examples of the lubricant include fatty acid amides such as ethylene bis stearic acid amide and oleic acid amide, and fatty acid metal salts such as zinc stearate and calcium stearate. Examples of the abrasive include silica, alumina, cerium oxide, and the like.

  The average particle diameter of fine particles such as these internal additives, charge control agents, inorganic fine particles, organic fine particles, lubricants and abrasives is preferably 1 μm or less, and more preferably in the range of 0.01 μm to 1 μm. . When the average particle diameter exceeds 1 μm, the particle size distribution of the finally obtained electrostatic charge developing toner becomes wide, or free particles are likely to be generated, and the performance and reliability of the toner are likely to be lowered. In this embodiment, by adjusting the average particle diameter to the above range, uneven distribution of the composition among the toner particles can be suppressed, and variations in toner performance and reliability can be suppressed low.

  The average particle size can be measured using, for example, a laser diffraction particle size distribution measuring device, a centrifugal particle size distribution measuring device, or the like.

  In addition, these fine particles can be appropriately added as long as they do not impair the purpose of the present embodiment, but are generally very small, specifically in the range of 0.01 to 5% by weight. It is preferable that it is in the range of 0.01 to 3% by weight.

  Using the materials described above, the agglomeration process includes binder resin fine particle dispersion, colorant particle dispersion, release agent particle dispersion, etc., and other components are added and mixed as necessary. The dispersed liquid is heated at room temperature to a glass transition temperature of the resin plus about 5 ° C. with stirring to agglomerate the resin fine particles and the colorant to form aggregated particles.

  In the aggregation step, the binder resin fine particle dispersion mixed with each other, the colorant particle dispersion, and, if necessary, particles in the release agent particle dispersion are aggregated to form aggregated particles. The agglomerated particles are formed by heteroaggregation or the like. For the purpose of stabilizing the agglomerated particles and controlling the particle size / particle size distribution, the aggregated particles are charged with a monovalent or higher charge such as an ionic surfactant having a polarity different from the agglomerated particles or a metal salt. It is formed by adding the compound which has.

  In the aggregation step, aggregated particles can be generated by changing the pH, and the particle size of the particles can be adjusted. At the same time, a flocculant may be added as a method of stably and rapidly agglomerating particles or obtaining agglomerated particles having a narrower particle size distribution.

  As the flocculant, a compound having a monovalent or higher charge is preferable, and specific examples thereof include water-soluble surfactants such as ionic surfactants and nonionic surfactants; hydrochloric acid, sulfuric acid, nitric acid, acetic acid Acids such as oxalic acid; metal salts of inorganic acids such as magnesium chloride, sodium chloride, aluminum sulfate, calcium sulfate, ammonium sulfate, aluminum nitrate, silver nitrate, copper sulfate, sodium carbonate; sodium acetate, potassium formate, sodium oxalate, phthalate Metal salts of aliphatic acids and aromatic acids such as sodium acid and potassium salicylate; Metal salts of phenols such as sodium phenolate; Metal salts of amino acids; Aliphatic and aromatic such as triethanolamine hydrochloride and aniline hydrochloride And inorganic acid salts of amines.

  The flocculant is more preferably a metal salt of an inorganic acid such as magnesium chloride, sodium chloride, aluminum sulfate, calcium sulfate, ammonium sulfate, aluminum nitrate, silver nitrate, copper sulfate, sodium carbonate; sodium acetate, potassium formate, sodium oxalate, Inorganic and organic metal salts such as aliphatic acids such as sodium phthalate and potassium salicylate; more preferably, polyvalent inorganic metal salts such as aluminum sulfate, aluminum nitrate, aluminum chloride, and magnesium chloride stabilize aggregated particles. Can be suitably used from the standpoints of stability, stability of the flocculant with heat and aging, and removal during washing.

  The amount of these flocculants to be added varies depending on the valence of the charge, but all of them are small, and are about 3% by weight or less in the case of monovalent and 1% in the case of divalent with respect to the binder resin fine particles. In the case of trivalent, it is about 0.5% by weight or less. Since a smaller amount of the flocculant is preferable, a compound having a higher valence is preferable.

  The volume average particle diameter of the aggregated particles is preferably in the range of 1 μm to 4.5 μm.

  Resin fine particles (additional fine particles) may be additionally added to the aggregated particles thus formed to form a coating layer on the surface of the aggregated particles (adhesion step). Next, the heat treatment is performed at a temperature equal to or higher than the glass transition temperature of the resin to fuse the aggregated particles to obtain a toner particle-containing liquid (toner particle dispersion), and then cooled. Next, the obtained toner particle-containing liquid is treated by centrifugal separation or suction filtration to separate the toner particles, and washed 1 to 3 times with ion exchange water. At that time, the cleaning effect can be further enhanced by adjusting the pH. Thereafter, the toner particles are separated by filtration, washed 1 to 3 times with ion exchange water, and dried to obtain a toner.

In the present embodiment, various resin powders and inorganic compounds may be added as external additives to the surface of the toner particles as a fluidity improver. As the resin powder, spherical particles such as PMMA, nylon, melamine, benzoguanamine, and fluorine-based resin can be used. Examples of various known inorganic compounds include SiO ₂ , TiO ₂ , Al ₂ O ₃ , MgO, CuO, ZnO, SnO ₂ , CeO ₂ , Fe ₂ O ₃ , BaO, CaO, K ₂ O, and Na ₂ O. , ZrO ₂ , CaO · SiO ₂ , CaCO ₃ , K ₂ O (TiO ₂ ) _n , MgCO ₃ , Al ₂ O ₃ · 2SiO ₂ , BaSO ₄ , MgSO _{4 and the} like, preferably SiO ₂ , Examples thereof include TiO ₂ and Al ₂ O _3, but are not limited to these, and one or more of these may be used in combination. The particle diameter is preferably 0.1 μm or less, and the additive amount of the external additive can be used in the range of 0.1 to 20% by weight with respect to the toner particles.

  The composition of the toner can be selected according to the purpose. It may be used alone as a one-component developer, or may be used as a two-component developer in combination with a carrier. It is preferable to use it as an excellent two-component developer.

  The carrier used here is not particularly limited, and a carrier known per se can be used.

  Next, a resin-coated carrier will be described as a specific example of the carrier. As the core particle (core material) of the carrier, normal iron powder, ferrite, magnetite molding, etc. can be used, and the volume average particle diameter D50v is preferably in the range of 30 μm to 200 μm.

  Examples of the core particle coating resin include styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, Α-methylene fatty acid monocarboxylic acids such as methyl methacrylate, n-propyl methacrylate, lauryl methacrylate and 2-ethylhexyl methacrylate; nitrogen-containing acrylics such as dimethylaminoethyl methacrylate; vinyl nitriles such as acrylonitrile and methacrylonitrile Vinyl pyridines such as 2-vinyl pyridine and 4-vinyl pyridine; vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; vinyl kets such as vinyl methyl ketone, vinyl ethyl ketone and vinyl isopropenyl ketone; Olefins such as tones, ethylene and propylene; vinyl-based fluorine-containing monomers such as vinylidene fluoride, tetrafluoroethylene and hexafluoroethylene; homopolymers such as, or copolymers composed of two or more types of monomers, Examples include silicones such as methylsilicone and methylphenylsilicone; polyesters containing bisphenol and glycol; epoxy resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and polycarbonate resins.

  These coating resins may be used alone or in combination of two or more. The amount of the coating resin used is preferably in the range of 0.1 to 10 parts by mass and more preferably in the range of 0.5 to 3.0 parts by mass with respect to 100 parts by mass of the core particles.

  For the production of the carrier, a heating kneader, a heating Henschel mixer, a UM mixer, or the like can be used. Depending on the amount of the coating resin, a heating fluidized rolling bed, a heating kiln, or the like can be used. The mixing ratio of the toner and the carrier in the developer used in this embodiment is not particularly limited and can be appropriately selected depending on the purpose.

  The image forming method using the electrostatic charge developing toner according to the exemplary embodiment includes a step of forming an electrostatic charge image on the surface of the electrostatic charge image carrier, and the surface of the developer carrier with the electrostatic charge image developer containing the toner. An image forming method comprising: a step of developing an electrostatic charge image to form a toner image; a step of transferring the toner image to the surface of a recording medium; and a step of thermally fixing the toner image. Each process itself is a general process, and is described in, for example, Japanese Patent Application Laid-Open No. 56-40868, Japanese Patent Application Laid-Open No. 49-91231, and the like, and can be suitably applied in this embodiment. Note that the image forming method according to the present embodiment can be carried out by using an image forming apparatus such as a copier, a printer, a facsimile machine, or a complex machine thereof known per se. Further, in the step of transferring the toner image onto the transfer body, the toner image on the electrostatic charge image carrier may be directly transferred to the recording medium, or the recording medium may be transferred via the intermediate transfer body. It may be carried out by a transfer method.

  As the fixing device used for the electrostatic charge developing toner according to the exemplary embodiment, a publicly known fixing device can be used. It is preferable to provide a release layer on the heating member of the fixing device. The release layer is preferably formed of a material excellent in releasability with respect to the toner, for example, silicone rubber, fluorine resin, or the like, for the purpose of preventing the toner from adhering. Specific examples of the fluororesin include, for example, a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether, a copolymer of tetrafluoroethylene and ethylene, and a copolymer of tetrafluoroethylene and hexafluoroethylene. Preferably mentioned. The thickness of the release layer can be appropriately selected according to the purpose, but is preferably in the range of 10 μm to 60 μm.

  In the toner configuration in the present embodiment, since a release agent is included, a releasable liquid to be applied to a heating member such as silicone oil is not necessary, but 1 μL or less per A4 sheet for the purpose of securing a high-temperature fixing area. You may use about.

  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.

  First, the toner used in Examples and Comparative Examples will be described. In the following, “part” means “part by weight”.

  The particle size distribution measurement in this example will be described. A Coulter Counter TA-II type (manufactured by Beckman-Coulter) is used as the measuring apparatus, and ISOTON-II (manufactured by Beckman-Coulter) is used as the electrolyte.

  As a measurement method, 0.5 mg to 50 mg of a measurement sample is added to 2 mL of a 5% aqueous solution of a surfactant, preferably sodium alkylbenzenesulfonate as a dispersant. This is added to 100 to 150 mL of the electrolyte solution. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 minute, and the particle size distribution of particles of 0.6 μm to 18 μm is obtained using the 30 μm aperture as the aperture diameter by the Coulter Counter TA-II type. Measure volume average distribution and number average distribution. The number of particles to be measured is 50,000. From these volume average distribution and number average distribution, the weight average particle diameter is obtained.

The particle size distribution of the toner can be represented by a particle size distribution index GSD. The GSD can be expressed by the following formula.
GSD = [(d16 / d84)] ^0.5

  In the above formula, d16, d50, and d84 indicate the diameters of 16%, 50%, and 84%, respectively, counted from the large particle diameter side of the toner, and the numerical values are in the order of d16> d50> d84. It can be said that the smaller the GSD, the more uniform the toner. The GSD includes those calculated from the number average particle size and those calculated from the volume average particle size. Here, the GSD of the toner is calculated from the volume average particle size.

  The preferable range of the GSD is 1.25 or less, more preferably 1.22 or less, and still more preferably 1.20 or less. When the GSD exceeds 1.25, not only the image quality is deteriorated but also the fine powder is increased, so that the life of the carrier is shortened, which is not preferable.

  The average particle size of the binder resin fine particles, the colorant fine particles and the release agent fine particles was measured using a laser diffraction type particle size distribution analyzer (LA-700 manufactured by Horiba, Ltd.).

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

  The glass transition point of the binder resin fine particles was measured using a differential scanning calorimeter (DSC-50, manufactured by Shimadzu Corporation) under conditions of a heating rate of 3 ° C./min.

The content of the carboxylic acid group-containing compound in the toner was determined using the following method. A high performance liquid chromatograph (manufactured by Nihon Analytical Industrial Co., Ltd .: LC-908) is a preparative column in which the solvent is tetrahydrofuran, the flow rate is 7 mL / min, and the column temperature is 40 ° C. After fractionation using ¹ H-NMR (manufactured by Varian: UNITY-300 / 300 MHz), quantification was performed.

  The amount of charge was measured (measured value A) using TB-200 (manufactured by Toshiba Chemical Co.) within 30 minutes after adjusting the developer obtained by adjusting the developer below. After being left in a constant temperature and humidity chamber of 85% RH for about 12 hours, it was measured again (measurement value B). When measured value B / measured value A = charge retention ratio, 0.8 or more was evaluated as ◯, 0.7 or more and less than 0.8 as Δ, and less than 0.7 as x. If the charge retention rate is lower than 0.7, printing may occur at high temperatures and high humidity, which may cause image deterioration such as fogging.

First, various dispersions were prepared as follows.
(Preparation of resin fine particle dispersion (1))
・ Styrene 280 parts ・ n-butyl acrylate 100 parts ・ acrylic acid 8 parts ・ dodecyl mercaptan 10 parts ・ carbon tetrabromide 3 parts

  Each of the above components is mixed and dissolved in advance to prepare a solution, and 7 parts of a nonionic surfactant (Sanyo Kasei Co., Ltd .: Novonyl) and an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK) ) A surfactant solution having 10 parts dissolved in 520 parts of ion-exchanged water and the solution were put into a flask and emulsified. While slowly mixing for 10 minutes, 70 parts of ion-exchanged water in which 3 parts of ammonium persulfate was dissolved was added to perform nitrogen substitution. Thereafter, while stirring the flask, the contents were heated in an oil bath until the content reached 70 ° C., and emulsion polymerization was continued for 6 hours. Then, this reaction liquid is cooled to room temperature to obtain a resin dispersion (1) having an average particle diameter of 150 nm, a glass transition point of 58.0 ° C., a weight average molecular weight Mw of 25000, and Mw / Mn of 2.5. It was.

(Preparation of resin fine particle dispersion (2))
・ Styrene 280 parts ・ n-butyl acrylate 100 parts ・ acrylic acid 4 parts ・ dodecyl mercaptan 10 parts ・ carbon tetrabromide 3 parts

  Each of the above components is mixed and dissolved in advance to prepare a solution, and 7 parts of a nonionic surfactant (Sanyo Kasei Co., Ltd .: Novonyl) and an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK) ) A surfactant solution having 10 parts dissolved in 520 parts of ion-exchanged water and the solution were put into a flask and emulsified. While slowly mixing for 10 minutes, 70 parts of ion-exchanged water in which 3 parts of ammonium persulfate was dissolved was added to perform nitrogen substitution. Thereafter, while stirring the flask, the contents were heated in an oil bath until the content reached 70 ° C., and emulsion polymerization was continued for 6 hours. Then, this reaction liquid was cooled to room temperature to obtain a resin dispersion (2) having an average particle diameter of 160 nm, a glass transition point of 57.6 ° C., a weight average molecular weight of 27000, and Mw / Mn of 2.4.

(Preparation of colorant dispersion (1))
・ Carbon black (Mitsubishi Chemical Corporation: MA100S) 70 parts ・ Anionic surfactant Neogen RK (Daiichi Kogyo Seiyaku Co., Ltd.) 3 parts ・ Ion-exchanged water 400 parts

  The above components are mixed and dissolved, and then dispersed using a homogenizer (manufactured by IKA, Ultra Tarrax), and a colorant (carbon black dispersion) having an average particle size of 200 nm is dispersed. (1) was obtained.

(Preparation of release agent dispersion (1))
・ Polyethylene wax (melting point: 109 ° C., crystallinity 67) 100 parts ・ Anionic surfactant (Takemoto Yushi Co., Ltd .: Pionin A-45-D) 2 parts ・ Ion-exchanged water 500 parts

  Each of the above components is mixed and dissolved, dispersed using a homogenizer (IKA, Ultra Tarrax), then dispersed with a pressure discharge type homogenizer, and release agent fine particles having an average particle size of 280 nm (polyethylene wax) A release agent dispersion liquid (1) obtained by dispersing the above was obtained.

<Example 1>
(Preparation of Toner A)
-Resin fine particle dispersion (2) 300 parts-Colorant dispersion (1) 100 parts-Release agent dispersion (1) 100 parts-Cationic surfactant (manufactured by Kao Corporation: Sanizol B50) 3 parts-Carboxylic acid Group containing compound (GSM 151 manufactured by Gifu Shellac Co., Ltd., styrene-maleic acid copolymer, weight average molecular weight = 1500, acid value = 470) ammonia 40% aqueous solution 5 parts ion exchange water 400 parts

  The above components were mixed and dispersed in a round bottom stainless steel flask using a homogenizer (manufactured by IKA, Ultra Tarrax T50), and then heated with stirring in an oil bath for heating, and the viscosity of the dispersion was slightly increased at 48 ° C. Was raised but could be sufficiently stirred. The mixture was heated to 60 ° C. and held for 30 minutes to form aggregated particles. When a part of the obtained aggregated particles was observed with an optical microscope, the average particle diameter of the aggregated particles was about 4.5 μm. To this agglomerated particle liquid, 30 parts of the resin dispersion liquid (2) was gently added, and further heated and stirred at 60 ° C. for 30 minutes to obtain an agglomerated particle liquid (A). The average particle diameter of the aggregated particles in the obtained aggregated particle liquid was about 5.4 μm.

  Subsequently, after adjusting pH to 7.5 with aqueous ammonia, it heated to 97 degreeC and was hold | maintained as it was for 7 hours, and the aggregated particle was united. Then, after cooling and sufficiently washing with filtration and ion-exchanged water, filtration was performed with a 400 mesh sieve, and the amount of coarse powder on the mesh was measured. The amount of coarse mesh powder was expressed as% by weight based on the amount of toner charged. The volume average particle diameter D50v of the fused particles was measured with a coulter counter and found to be 5.3 μm. This was dried with a vacuum dryer to obtain toner A. The content of the carboxylic acid group-containing compound in the toner was 0.08% by weight.

(Preparation of developer A)
To 100 parts of the obtained toner A, 3.3 parts of colloidal silica (manufactured by Nippon Aerosil Co., Ltd .: R972) was added and mixed using a Henschel mixer to obtain an electrostatic charge developing toner. Then, a ferrite carrier having a volume average particle diameter D50v of 45 μm coated with 1% by weight of polymethyl methacrylate (manufactured by Soken Chemical Co., Ltd.) is weighed in a glass bottle so that the toner concentration becomes 5% by weight, and 5% on a ball mill table. The developer A was obtained by mixing for minutes.

(Image formation and evaluation)
Using the developer A obtained, a black color image was output on recording paper (Fuji Xerox Office Supply Co., Ltd .: J paper) using a modified Documentcolor 400 machine, 10,000 sheets at 23 ° C / 55% RH, 28 ° C / 85% A running test of 10,000 sheets was performed at RH to confirm image stability. Image stability was evaluated according to the following criteria. The results are shown in Table 1. The allowable range of image stability is ◯ and Δ based on the following evaluation criteria.
○: Image density reduction or non-image area fogging is not confirmed Δ: Image density reduction or non-image area fogging is slightly observed ×: Image density reduction or non-image area fogging is confirmed

<Example 2>
(Creation of toner B, adjustment of developer B, image formation / evaluation)
Instead of 5 parts of GSM151 as a carboxylic acid group-containing compound, except that 5 parts of 40% ammonia aqueous solution of GSM301 (styrene-maleic acid copolymer, weight average molecular weight = 3000, acid value = 470) manufactured by Gifu Shellac Co., Ltd. was used. In the same manner as in Example 1, toner B and developer B were obtained. In the coagulation process, the viscosity of the dispersion slightly increased at 48 ° C., but could be sufficiently stirred. The content of the carboxylic acid group-containing compound in the toner was 0.15% by weight. Using the obtained developer B, image stability was evaluated in the same manner as in Example 1. The results are shown in Table 1.

<Example 3>
(Creation of toner C, adjustment of developer C, image formation / evaluation)
Instead of 5 parts of GSM151 as a carboxylic acid group-containing compound, 5 parts of 40% ammonia aqueous solution of SMA 1440 (styrene-maleic acid copolymer, weight average molecular weight = 2500, acid value = 175) manufactured by Elf Atchem Japan A toner C and a developer C were obtained in the same manner as in Example 1 except that. In the flocculation process, the viscosity of the dispersion slightly increased, but could be sufficiently stirred. The content of the carboxylic acid group-containing compound in the toner was 0.20% by weight. Using the obtained developer C, image stability was evaluated in the same manner as in Example 1. The results are shown in Table 1.

<Example 4>
(Creation of toner D, adjustment of developer D, image formation / evaluation)
A toner D and a developer D were obtained in the same manner as in Example 1 except that the amount of the carboxylic acid group-containing compound GSM151 added was 1 part. In the coagulation process, the viscosity of the dispersion slightly increased at 48 ° C., but could be sufficiently stirred. The content of the carboxylic acid group-containing compound in the toner was 0.02% by weight. Using the obtained developer D, image stability was evaluated in the same manner as in Example 1. The results are shown in Table 1.

<Comparative Example 1>
(Production of Toner E)
-Resin fine particle dispersion (1) 300 parts-Colorant dispersion (1) 100 parts-Release agent dispersion (1) 100 parts-Cationic surfactant (manufactured by Kao Corporation: Sanizol B50) 3 parts-Ion exchange 400 parts of water

  When each of the above components is mixed and dispersed in a round bottom stainless steel flask using a homogenizer (manufactured by IKA, Ultra Tarrax T50) and then heated with stirring in a heating oil bath, the viscosity of the dispersion becomes 45 ° C. Although it was raised and stirring was not sufficient, it continued to be heated and the viscosity began to drop at about 52 ° C. The mixture was heated to 60 ° C. and held for 30 minutes to form aggregated particles. When a part of the obtained aggregated particles was observed with an optical microscope, the average particle diameter of the aggregated particles was about 4.8 μm. To this agglomerated particle liquid, 30 parts of the resin dispersion liquid (1) was gradually added, and further heated and stirred at 60 ° C. for 30 minutes to obtain an agglomerated particle liquid (E). The average particle size of the aggregated particles in the obtained aggregated particle liquid was about 5.5 μm.

  Subsequently, after adjusting pH to 7.5 with aqueous ammonia, it heated to 97 degreeC and was hold | maintained as it was for 7 hours, and the aggregated particle was united. Then, after cooling and sufficiently washing with filtration and ion-exchanged water, filtration was performed with a 400 mesh sieve, and the amount of coarse powder on the mesh was measured. The volume average particle diameter D50v of the fused particles was measured with a coulter counter and found to be 5.6 μm. This was dried with a vacuum dryer to obtain toner E.

(Preparation of developer E)
To 100 parts of toner E, 3.7 parts of colloidal silica (manufactured by Nippon Aerosil Co., Ltd .: R972) was added and mixed using a Henschel mixer to obtain an electrostatic charge developing toner. Then, a ferrite carrier having a volume average particle diameter of 50 μm coated with 1% mass of polymethyl methacrylate (manufactured by Soken Chemical Co., Ltd.) is weighed in a glass bottle so that the toner concentration is 5% by weight and mixed on a ball mill table for 5 minutes Developer E was obtained.

(Image formation and evaluation)
In the same manner as in Example 1, a black image was output on a recording sheet (Fuji Xerox Office Supply Co., Ltd .: J paper) with a modified Documentcolor 400 machine, and the image stability was confirmed. The results are shown in Table 1.

<Comparative example 2>
(Production of Toner F)
-Resin fine particle dispersion (2) 300 parts-Colorant dispersion (1) 100 parts-Release agent dispersion (1) 100 parts-Cationic surfactant (manufactured by Kao Corporation: Sanizol B50) 3 parts-Ion exchange 400 parts of water

  When each of the above components is mixed and dispersed in a round bottom stainless steel flask using a homogenizer (manufactured by IKA, Ultra Tarrax T50) and then heated with stirring in a heating oil bath, the viscosity of the dispersion becomes 42 ° C. Ascending, the agitation was not sufficient, and the surface of the dispersion could not be agitated at all. Subsequent heating started to lower the viscosity at about 56 ° C. The mixture was heated to 60 ° C. and held for 30 minutes to form aggregated particles. When a part of the obtained aggregated particles was observed with an optical microscope, the average particle diameter of the aggregated particles was about 5.0 μm. To this agglomerated particle liquid, 30 parts of the resin dispersion liquid (1) was gradually added, and further heated and stirred at 60 ° C. for 30 minutes to obtain an agglomerated particle liquid (F). The average particle size of the aggregated particles in the obtained aggregated particle liquid was about 5.6 μm.

  Subsequently, after adjusting pH to 7.5 with aqueous ammonia, it heated to 97 degreeC and was hold | maintained as it was for 7 hours, and the aggregated particle was united. Then, after cooling and sufficiently washing with filtration and ion-exchanged water, filtration was performed with a 400 mesh sieve, and the amount of coarse powder on the mesh was measured. The volume average particle diameter D50v of the fused particles was measured by a coulter counter and found to be 5.5 μm. This was dried with a vacuum dryer to obtain toner F.

(Preparation of developer F)
To 100 parts of toner F, 3.7 parts of colloidal silica (manufactured by Nippon Aerosil Co., Ltd .: R972) was added and mixed using a Henschel mixer to obtain an electrostatic charge developing toner. Then, a ferrite carrier having a volume average particle diameter of 50 μm coated with 1% by mass of polymethyl methacrylate (manufactured by Soken Chemical Co., Ltd .: weight average molecular weight 82100) is weighed in a glass bottle so that the toner concentration becomes 5% by weight, The developer F was obtained by mixing for 5 minutes.

(Image formation and evaluation)
In the same manner as in Example 1, a black image was output on a recording sheet (Fuji Xerox Office Supply Co., Ltd .: J paper) with a modified Documentcolor 400 machine, and the image stability was confirmed. The results are shown in Table 1.

<Comparative Example 3>
(Creation of toner G, adjustment of developer G, image formation / evaluation)
Instead of 5 parts of GSM151 as a carboxylic acid group-containing compound, except that 5 parts of 40% ammonia aqueous solution of 1001 (styrene-maleic acid copolymer, weight average molecular weight = 10000, acid value = 470) manufactured by Gifu Shellac Co., Ltd. was used. In the same manner as in Example 1, toner G and developer G were obtained. In the agglomeration process, the viscosity of the dispersion increased at 40 ° C. and could not be sufficiently stirred, but subsequently heated and started to decrease at about 56 ° C. The mixture was heated to 60 ° C. and held for 30 minutes to form aggregated particles. The content of the carboxylic acid group-containing compound in the toner was 0.55% by weight. Using the obtained developer G, the image stability was evaluated in the same manner as in Example 1. The results are shown in Table 1.

<Comparative example 4>
(Creation of toner H, adjustment of developer H, image formation / evaluation)
Instead of 5 parts of GSM151 as a carboxylic acid group-containing compound, 5 parts of 40% ammonia aqueous solution of SMA 3840 (styrene-maleic acid copolymer, weight average molecular weight = 2300, acid value = 105) manufactured by Elf Atchem Japan A toner H and a developer H were obtained in the same manner as in Example 1 except that. In the agglomeration process, the viscosity of the dispersion increased at 45 ° C. and could not be sufficiently stirred, but subsequently heated and started to decrease at about 52 ° C. The mixture was heated to 60 ° C. and held for 30 minutes to form aggregated particles. The content of the carboxylic acid group-containing compound in the toner was 0.25% by weight. Using the obtained developer H, the image stability was evaluated in the same manner as in Example 1. The results are shown in Table 1.

<Comparative Example 5>
(Creation of toner I, adjustment of developer I, image formation / evaluation)
Toner I and developer I were obtained in the same manner as in Example 1 except that the addition amount of the carboxylic acid group-containing compound GSM151 was 20 parts. In the flocculation process, the viscosity of the dispersion did not increase, and was heated to 60 ° C. and held for 30 minutes to form flocculated particles. The content of the carboxylic acid group-containing compound in the toner was 0.8% by weight. Using the obtained developer I, the image stability was evaluated in the same manner as in Example 1. The results are shown in Table 1.

  Thus, when the toner produced in Examples 1 to 4 was used, an increase in viscosity could be suppressed in the aggregation process. On the other hand, when the toners prepared in Comparative Examples 1 to 5 were used, a sudden increase in viscosity was observed in the aggregation process, making stirring difficult. Therefore, the coarse powder in the toner increased and the particle size distribution index GSD became a high value. Further, the toners produced in Examples 1 to 4 showed good results in both the charge retention ratio and the image stability after running test of 10,000 sheets, compared with the toners produced in Comparative Examples 1 to 5. It was.

Claims (4)

An electrostatic charge developing toner comprising a binder resin having an acidic polar group, a colorant, and a release agent, and obtained by agglomerating resin fine particles containing the binder resin,
The toner is
A styrene-maleic acid copolymer having a weight average molecular weight Mw in the range of 500 to 3000 and an acid value in the range of 150 to 600 mgKOH / g,
Including
The toner for electrostatic charge development, wherein the content of the styrene-maleic acid copolymer in the toner is 0.01% by weight or more and 0.5% by weight or less. A method for producing a toner for developing an electrostatic charge, comprising a binder resin having an acidic polar group, a colorant, and a release agent, and obtained by aggregating resin fine particles containing the binder resin.
In the step of aggregating the resin fine particles,
A styrene-maleic acid copolymer having a weight average molecular weight Mw in the range of 500 to 3000 and an acid value in the range of 150 to 600 mgKOH / g,
Use
The method for producing a toner for electrostatic charge development, wherein the content of the styrene-maleic acid copolymer in the toner is 0.01% by weight or more and 0.5% by weight or less.   An electrostatic charge developing developer comprising the electrostatic charge developing toner according to claim 1.   An image forming method using the electrostatic charge developing toner according to claim 1.