JP2008158319A - Toner for electrostatic charge development, developer for electrostatic charge development and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve cleaning characteristics while keeping transfer efficiency. <P>SOLUTION: The toner for electrostatic charge development is characterized in that: the toner has resin composition projections represented by an outer diameter ra on the surface of the toner particle; the resin composition projections have a crosslinked structure; the outer diameter ra and the volume average particle diameter D50 of the toner base particles satisfy expression (1):0.01<ra/D50<0.04, wherein ra is the outer diameter (nm) of the resin composition projections and D50 is the volume average toner particle diameter (nm); the solubility parameter of the resin composition projections and the solubility parameter of the resin composition of the toner base particles are in a relationship of expression (2):1.5<δa-δ<3 [(cal/ml)<SP>1/2</SP>/25°C], wherein δa is the solubility parameter of the resin composition projections and δ is the solubility parameter of the toner base particles; and the shape factor SF1 of the toner ranges from 110 to 120. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electrostatic charge developing toner (hereinafter also referred to as electrophotographic toner), an electrostatic charge developing developer, and an image forming apparatus.

  Methods for visualizing image information through an electrostatic latent image, such as electrophotography, are currently used in various fields. In electrophotography, an electrostatic image is formed on a photoreceptor by a charging / exposure process, developed with a developer containing toner, and then visualized through a toner image transfer and fixing process. The developer used here includes 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. The method for producing the toner is usually a thermoplastic resin. A kneading and pulverizing method is used, in which melt is kneaded together with a release agent such as a pigment, a charge control agent, and wax, cooled, finely pulverized, and further classified. The formed toner is added with inorganic or organic particles for improving fluidity and cleaning properties as required, and is adhered to the surface of the toner particles.

  In ordinary kneading and pulverization methods, the toner shape and the surface structure of the toner are indefinite, although it varies slightly depending on the pulverization properties of the materials used and the conditions of the pulverization process. is there. In particular, in the case of a toner using a material having high pulverization properties, the toner is often pulverized by mechanical force in a developing machine, and further, generation of fine powder or change in toner shape is often caused. Due to these effects, in the two-component developer, the charging deterioration of the developer is accelerated due to adhesion of fine powder to the carrier surface, and in the one-component developer, toner scattering occurs due to the expansion of the particle size distribution, and the toner shape Deterioration in image quality is likely to occur due to a decrease in developability due to changes in the image quality. When a toner such as wax is internally added to form a toner, depending on the combination with a thermoplastic resin, the release agent is often exposed on the surface and various effects are caused during development. The irregular shaped toner is advantageous in terms of cleaning property, which removes untransferred toner from the photoreceptor, and the surface wax is easily transferred by mechanical force, so that the surface of the developing roll, photoreceptor and carrier Contamination is likely to occur, leading to reduced reliability.

  On the other hand, in recent years, toner produced by a wet manufacturing method has been used. In the wet manufacturing method, generally, a spherical toner can be obtained. A characteristic of the spherical toner is high transfer efficiency. In addition, since it is possible to control the exposure of the release agent on the toner surface because it can be encapsulated in the release agent, it is less affected by the mechanical force in the developing machine, so that the generation of fine powder is small, and the development roll, photoconductor and It is advantageous for carrier surface contamination. However, when blade cleaning is used, there is a problem that the toner passes through the cleaning blade and the cleaning property is deteriorated.

  Therefore, in Patent Document 1, in the toner for developing an electrostatic charge image containing at least a resin, a colorant, and a release agent, the toner surface has a protrusion having a height of 0.05 to 2 μm, and at least a part of the protrusion. Has proposed a toner for developing an electrostatic charge image that contains a release agent and has an element ratio of 10 atom% or less attributable to the release agent in the toner surface elements determined by X-ray photoelectron spectroscopy.

  Patent Document 2 discloses an electrophotographic toner containing a binder resin and a colorant and having a core-shell structure, the core mainly including a crystalline resin, and the shell is 15% by mass or more and 120% by mass or more with respect to the core. There has been proposed an electrophotographic toner that has a mass% or less, a shell having hemispherical protrusions with a step of 0.3 μm or more, and a shell produced by an emulsion aggregation method.

JP 2002-075251 A JP 2005-274964 A

  As described above, in the conventional kneading and pulverization method, the toner shape and surface property change depending on the pulverization property of the material used and the conditions of the pulverization process, and it is difficult to control the toner shape and surface property intentionally. In recent years, toner manufactured by a wet manufacturing method has been used. However, although toner particles are spheroidized and the transfer efficiency is improved, the toner particles are spherical. When used, the cleaning property may deteriorate and color streaks may occur.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an electrostatic charge developing toner, an electrostatic charge developing developer, and an image forming apparatus, which mainly achieve both transfer efficiency and cleaning properties.

  The present invention is as follows.

(I) The surface of the toner has a resin composition protrusion indicated by an outer diameter ra, the resin composition protrusion has a crosslinked structure, and the outer diameter ra of the resin composition protrusion and a volume average particle of toner base particles The relationship between the diameter D50 and the solubility parameter of the resin composition protrusion and the solubility parameter of the resin composition of the toner base particles is expressed by the following equation (2): The toner is an electrostatic charge developing toner having a toner shape factor SF1 in the range of 110 to 120.
(Equation 1)
0.01 <ra / D50 <0.04 Formula (1)
(In the formula, ra: outer diameter of protrusion of resin composition nm, D50: volume average toner particle diameter nm)
1.5 <δa−δ <3 [(cal / ml) ^1/2 / 25 ° C.] Formula (2)
(Wherein, δa: solubility parameter of resin composition protrusion, δ: toner mother particle resin solubility parameter)

  (II) An electrostatic charge image developing developer containing the electrostatic charge image developing toner described in (I) above.

  (III) A latent image forming means for forming a latent image on the latent image carrier, a developing means for developing the latent image using an electrostatic charge developing developer, and the developed toner image via an intermediate transfer member Alternatively, the image forming apparatus includes: a transfer unit that transfers the toner image on the transfer body without being interposed; and a fixing unit that adds and fixes the toner image on the transfer body. An image forming apparatus which is the developer for electrostatic charge development described in II).

  According to the present invention, the blade cleaning property is improved by the resin composition protrusion on the toner surface, and on the other hand, the transfer efficiency can be increased because the shape of the toner particles is almost spherical.

[Toner for electrostatic image development]
The electrostatic image developing toner of the present embodiment (hereinafter also referred to as “toner”) has a resin composition protrusion indicated by an outer diameter ra on the surface of the toner, and the resin composition protrusion has a crosslinked structure. As shown in FIG. 2, the relationship between the outer diameter ra of the resin composition protrusion and the volume average particle diameter D50 of the toner base particle is expressed by the equation (1), the solubility parameter of the composition protrusion, and the toner base In the electrostatic charge developing toner, the relationship between the particle resin composition and the solubility parameter is expressed by the following formula (2), and the toner shape factor SF1 is in the range of 110 to 120.
(Equation 2)
0.01 <ra / D50 <0.04 Formula (1)
(In the formula, ra: outer diameter of protrusion of resin composition nm, D50: volume average toner particle diameter nm)
1.5 <δa−δ <3 [(cal / ml) ^1/2 / 25 ° C.] Formula (2)
(Wherein, δa: solubility parameter of resin composition protrusion, δ: toner mother particle resin solubility parameter)

  As a method for producing an electrostatic charge image developing toner in the present embodiment, it can be applied to a wet production toner generally called a chemical production toner and, in some cases, a kneading pulverization method, but is particularly effective in a wet production method. In this case, the wet process toner (chemical process toner) is a toner that emulsifies and disperses resin and monomer components in an aqueous medium such as an emulsion polymerization aggregation method, suspension polymerization method, and melt suspension method, and if necessary, undergoes a polymerization process. In particular, the method is particularly effective when a resin component polymerized from a vinyl monomer is used as the toner constituent.

  The method for producing an electrostatic charge image developing toner in the present embodiment includes, for example, (i) a toner base particle obtained by polymerizing a polymerizable monomer containing a polymerizable monomer having a vinyl double bond in an aqueous solvent. (Ii) a part of the resin particle dispersion for toner base particles, a colorant particle dispersion obtained by dispersing at least a colorant, and optionally a release agent. And (iii) the same or different vinyl type as the polymerizable monomer having a vinyl double bond constituting the toner base particle resin. A step of polymerizing and crosslinking a polymerizable monomer containing a polymerizable monomer having a double bond together with a crosslinking agent in an aqueous solvent to obtain a resin particle dispersion for protrusions, and (iv) the resin particle dispersion for protrusions The remainder of the resin particle dispersion for toner base particles; Adding to the mixed solution; and (v) aggregating the toner base particle resin particles, the colorant particles, the release agent particles, and the protrusion resin particles to form aggregated particles, and then heating to form the aggregated particles. And a step of fusing the aggregated particles to produce an electrostatic image developing toner.

  Examples of the polymer monomer having a vinyl double bond for obtaining the resin particles forming the resin composition protrusions and the resin particles for toner base particles include, for example, a monomer containing a radical polymerizable vinyl group. Examples of the monomer containing a radical polymerizable vinyl group include aromatic vinyl monomers, (meth) acrylic acid ester monomers, vinyl ester monomers, vinyl ether monomers, and monoolefins. Mention may be made of monomeric monomers, diolefinic monomers, halogenated olefinic monomers and the like. Examples of the aromatic vinyl monomer include styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, p-methoxy styrene, p-phenyl styrene, p-chloro styrene, p-ethyl styrene, p. -N-butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, 2, Examples thereof include styrene monomers such as 4-dimethylstyrene and 3,4-dichlorostyrene and derivatives thereof. Examples of (meth) acrylic acid ester monomers include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, and methacrylic acid. Examples include butyl, hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, propyl γ-aminoacrylate, stearyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and the like. Examples of vinyl ester monomers include vinyl acetate, vinyl propionate, and vinyl benzoate. Examples of the vinyl ether monomer include vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl phenyl ether and the like. Examples of the monoolefin monomer include ethylene, propylene, isobutylene, 1-butene, 1-pentene, 4-methyl-1-pentene and the like. Examples of the diolefin monomer include butadiene, isoprene, chloroprene and the like. Examples of halogenated olefin monomers include vinyl chloride, vinylidene chloride, vinyl bromide, etc., but are not limited thereto, and these monomers may be used alone or in combination of two or more. It may be used.

  Furthermore, the polymerization of these monomers can be carried out in combination with known polymerization techniques such as emulsion polymerization, miniemulsion, suspension polymerization, and dispersion polymerization, initiators, emulsifiers, and stabilizers. is not.

  A chain transfer agent can be used in the polymerization of the monomers used in the resin particles for toner base particles and the resin particles forming the resin composition protrusions. Although there is no restriction | limiting in particular as a chain transfer agent, The compound which has a thiol component can be used. Specifically, alkyl mercaptans such as hexyl mercaptan, heptyl mercaptan, octyl mercaptan, nonyl mercaptan, decyl mercaptan, and dodecyl mercaptan are preferred, and in particular, the molecular weight distribution is narrow, so that the storage stability of the toner at high temperature is improved. preferable.

  Further, when the resin particles for toner base particles and the resin particles forming the resin composition protrusions are produced by radical polymerization of a polymerizable monomer, they can be polymerized using a radical polymerization initiator.

  There is no restriction | limiting in particular as an initiator for radical polymerization used here. Specifically, hydrogen peroxide, acetyl peroxide, cumyl peroxide, tert-butyl peroxide, propionyl peroxide, benzoyl peroxide, chlorobenzoyl peroxide, dichlorobenzoyl peroxide, bromomethylbenzoyl peroxide, lauroyl peroxide Ammonium persulfate, sodium persulfate, potassium persulfate, diisopropyl peroxycarbonate, tetralin hydroperoxide, 1-phenyl-2-methylpropyl-1-hydroperoxide, tert-butyl hydroperoxide pertriphenyl acetate, tert-butyl formate, Peroxides such as tert-butyl peracetate, tert-butyl perbenzoate, tert-butyl perphenylacetate, tert-butyl permethoxyacetate, tert-butyl perN- (3-toluyl) carbamate, 2,2 '-Azobisp Bread, 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-dihy Roxymethylphenylazo-2-methylmalonodinitrile, 2- (4-bromophenylazo) -2-allylmalonodinitrile, 2,2′-azobis-2-methylvaleronitrile, 4,4′-azobis-4 -Dimethyl cyanovalerate, 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-nitrophenylazobenzyl cyanoacetate ethyl, phenylazodiphenylmethane, phenylazotriphenylmeth Tan, 4-nitrophenylazotriphenylmethane, 1,1′-azobis-1,2-diphenylethane, poly (bisphenol A-4,4′-azobis-4-cyanopentanoate), poly (tetraethylene glycol) -2,2'-azobisisobutyrate) and the like, 1,4-bis (pentaethylene) -2-tetrazene, 1,4-dimethoxycarbonyl-1,4-diphenyl-2-tetrazene and the like Can be mentioned.

  On the other hand, the resin particles forming the resin composition protrusions are further crosslinked using a crosslinking agent with respect to the binder resin polymerized by the monomer and initiator. Examples of the crosslinking agent include the following: Things. In addition, a crosslinking agent can be used individually or in combination of 2 or more types.

  A crosslinkable monomer is a monomer having two or more polymerizable carbon-carbon unsaturated double bonds. Such monomers include, for example, aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene, and derivatives thereof; dimethacrylate compounds such as ethylene glycol dimethacrylate and diethylene glycol dimethacrylate, and intramolecular such as divinyl ether. And a compound having two vinyl groups in the molecule, such as pentaerythritol triallyl ether and trimethylolpropane triacrylate.

  When the functional group of the binder resin in the resin particles forming the resin composition protrusion has a carboxyl group, a compound having an epoxy group or an isocyanate group, a metal compound, or the like is preferably used as the crosslinking agent.

  As the compound having an epoxy group, a compound having two or more epoxy groups, for example, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, Glycerol triglycidyl ether, trimethylolpropane triglycidyl ether, 1,3,4-diepoxybutane, allyl glycidyl ether, glycidyl acrylate, β-methylglycidyl acrylate, glycidyl methacrylate, β-methyl methacrylate Glycidyl, etc.

  As the compound having an isocyanate group, a polyisocyanate compound such as tolylene diisocyanate, hydrogenated tolylene diisocyanate, diphenylmethane diisocyanate, xylene diisocyanate, hexamethylene diisocyanate, a prepolymer having an isocyanate group (hydroxyl-containing polyester, hydroxyl-containing polyether, etc.) And a polymer having an isocyanate group at the terminal obtained by reacting the above polyisocyanate with an excess amount of the above-mentioned polyisocyanate).

  The metal compound is preferably a water-soluble metal compound having a valence of 2 or more, and a halide of a metal such as boron, aluminum, iron, copper, zinc, tin, titanium, nickel, magnesium, vanadium, chromium, zirconium, etc. And salts (carbonates, nitrates, sulfates, etc.), oxides, hydroxides and the like. In particular, boric acid, borax, aluminum chloride, aluminum sulfate, ammonium zirconium carbonate, zirconium chloride, iron alum and the like are preferable.

  When the functional group of the binder resin in the resin particles forming the resin composition protrusion has a hydroxyl group, the crosslinking agent includes a compound having a carboxyl group or an acid anhydride group, a compound having an aldehyde group, and an epoxy group. A compound having an acrylamide moiety, a compound having an isocyanate group, a metal compound, and the like. Especially, the compound (especially polyhydric carboxylic acid or its acid anhydride) which has a carboxyl group or an acid anhydride group, and a metal compound are preferable.

  Examples of the polyvalent carboxylic acid include aliphatic polycarboxylic acid, alicyclic polycarboxylic acid, aromatic polycarboxylic acid, oxypolycarboxylic acid, and heterocyclic polycarboxylic acid.

  As aliphatic polycarboxylic acid, C2-10 aliphatic saturated polycarboxylic acid (for example, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, etc.), Alternatively, C4-6 aliphatic unsaturated polycarboxylic acids (fumaric acid, maleic acid, maleic anhydride, citraconic acid, mesaconic acid, itaconic acid, etc.) and the like can be mentioned.

  Examples of the alicyclic polycarboxylic acid include C8-10 alicyclic polycarboxylic acids (for example, 1,4-cyclohexanedicarboxylic acid, tetrahydrophthalic acid, hexahydrophthalic acid, etc.).

  Examples of the aromatic polycarboxylic acid include C8-12 aromatic polycarboxylic acids or acid anhydrides thereof (for example, phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, etc.). .

  Examples of the oxypolycarboxylic acid include C3-6 oxypolyvalent carboxylic acids (eg, tartronic acid, malic acid, tartaric acid, citric acid, etc.).

  The heterocyclic polyvalent carboxylic acid is a polyvalent carboxylic acid having at least one heteroatom selected from nitrogen, oxygen and sulfur atoms (for example, pyridinedicarboxylic acid, pyridinetricarboxylic acid, pyridinetetracarboxylic acid, tropic acid, etc.) Etc. As the polyvalent carboxylic acid in the heterocyclic polyvalent carboxylic acid, an aliphatic, alicyclic or aromatic polycarboxylic acid (particularly a C3-10 polycarboxylic acid) is preferably used.

  A salt or partial salt of a polyvalent carboxylic acid is also preferably used. Examples of the polyvalent carboxylates include inorganic salts such as ammonium salts and alkali metal salts (potassium salts, sodium salts, etc.) and organic salts such as tertiary amines. As the polyvalent carboxylic acid, maleic acid or its acid anhydride (maleic anhydride) is particularly preferable.

  As the compound having an aldehyde group, a compound having a plurality of aldehyde groups such as glyoxal, malonaldehyde, glutaraldehyde, terephthalaldehyde, dialdehyde starch, acrolein copolymer acrylic resin and the like are used.

  Examples of the nitrogen-containing compound include C1-C4 alkoxy melamines such as methoxymethyl melamine, methylol group-containing compounds such as N-methylol melamine and N-methylol urea, guanamines such as acetoguanamine and benzoguanamine, melamine-formalin resin, urea -Formalin resin or the like is used.

  Examples of the compound having an acrylamide group include methylene-bis (meth) acrylamide, N, N′-dimethylol-methylene-bisacrylamide, 1,1-bisacrylamide-ethane and the like.

  The compound having an epoxy group or an isocyanate group and the metal compound are as described above.

  In the case where the functional group of the binder resin in the resin particle forming the resin composition protrusion is a functional group other than a carboxyl group and a hydroxyl group, the functional group capable of reacting with the functional group in consideration of the above explanation. What is necessary is just to select the crosslinking agent which has group. For example, when the functional group is an amide group, a dihydroxy compound may be used.

  The weight ratio of the binder resin obtained by polymerizing the monomer in the resin particles forming the resin composition protrusions and the crosslinking agent used to crosslink the binder resin is determined as follows. The amount is usually 0.5 to 10 parts by weight, preferably 1 to 5 parts by weight, based on 100 parts by weight of the binder resin obtained by polymerization.

  As described above, the relationship between the outer diameter ra of the resin composition protrusion shown in FIG. 1 and the volume average particle diameter D50 of the toner base particles is 0.01 <ra / D50 <, as shown in the equation (1). 0.04 (in the formula, ra: outer diameter nm of the resin composition protrusion, D50: volume average toner particle diameter nm), and when ra / D50 is 0.01 or less, the cleaning property is deteriorated and the transferred image On the other hand, when ra / D50 is 0.04 or more, the chargeability is lowered, and the transferred image is fogged.

  Further, the outer diameter ra of the resin composition protrusions is obtained by observing the obtained toner with a scanning electron microscope (SEM), obtaining an average value of 100 resin composition protrusions, and calculating the average value of the outer diameters as ra. To do.

  On the other hand, the volume average particle diameter D50 of the toner base particles is smaller than the particle size range (channel) obtained by dividing the particle size distribution of the toner measured using a Coulter Multisizer II (manufactured by Beckman-Coulter). A cumulative distribution is drawn from the small-diameter side with respect to the volume of the toner particles, and the particle diameter at which 50% is accumulated is defined as a volume average particle diameter D50v. Details of the measurement will be described later.

  Further, in the toner of the present embodiment, assuming that the surface area of the toner base particles shown in FIG. 1 is 100, the ratio of the surface area occupied by the resin composition protrusions is usually 4 to 80, preferably 8 to 40. .

  Further, the resin in the resin particles for toner base particles and the resin of the resin particles forming the resin composition protrusion may be the same or different, but the glass transition temperature (Tg) of both resins. The composition of the two resins is selected so that the difference between the two is 5 ° C. or more. When the difference between the glass transition temperatures (Tg) of the two resins is less than 5 ° C., the Tg is too close, and the resin composition protrusions are contained in the toner base particles when the aggregated particles at the time of toner production are fused with heat. In some cases, a protrusion having a predetermined size is not formed.

In the toner of the present embodiment, the solubility parameter δa of the resin forming the resin composition protrusion and the solubility parameter δ of the resin for toner base particles are 1.5 <δa−δ <3 [( cal ^{/ ml)} satisfy the 1/2 / 25 ℃]. When this difference is 1.5 or less, the resin composition protrusions are easily included in the toner base particles, and the protrusions in the ra / D50 range are not formed. Color streaks occur. On the other hand, when the difference is 3 or more, the resin composition protrusions are ejected from the toner base particles when the aggregated particles at the time of toner production are fused together, and a predetermined amount of protrusions are formed on the surface of the toner base particles. As a result, the cleaning property of the toner is deteriorated, filming on the photoconductor occurs over time, and color streaks of the transferred image also occur.

As a method for calculating the solubility parameter, in the present invention, the most general-purpose method widely proposed and proposed by Fedors et al., That is, the sum of the cohesive energy per unit functional group Δe _i and the molecule The method of determining the sum Δv _i of the volume and obtaining it from its relaxation was adopted (R. F. Fedors, Polym. Eng. Sci., 14, 147 (1974)).

  Further, in the toner base resin and the resin composition protrusion in the present embodiment, the respective mass fractions are calculated from the blended actual amounts of the monomer components used for the polymerization, and the respective masses of the respective polymerization components are charged. The solubility parameter of each polymerization unit calculated from each monomer component unit is obtained as shown in the following formula, assuming that it is incorporated in the polymer chain at a fraction, and each weight fraction is calculated as the value. The total of these multiplied by was used as the solubility parameter of the polymer. The solubility parameter in the present invention is a solubility parameter at 25 ° C., and is described in, for example, the above-mentioned (RF Fedors, Polym. Eng. Sci., 14, 147 (1974)).

However, [delta] _overall: solubility parameter of the polymer ^{[(cal / ml) 1/2 /} 25 ℃]
w _i : Mass fraction calculated from each monomer Δe _i : Sum of cohesive energy per unit functional group of each monomer component (cal / mol)
Δv _i : Sum of molecular volume per unit functional group (cc / mol / 25 ° C)

  The toner shape factor SF1 in the present embodiment is preferably set to 110 ≦ SF1 ≦ 120 from the viewpoint of image formability. For the shape factor SF1, the average value of the shape factor (the square of the maximum length / projection area) is calculated by the following method, for example. That is, the optical microscope image of the toner spread on the slide glass is taken into a Luzex image analyzer through a video camera, and (maximum squared) × π × 100 / (projected area × 4) is calculated from 100 toners. The average value is obtained.

  Next, other components of the toner will be described.

  First, as colorants, carbon black such as furnace black, channel black, acetylene black, thermal black, inorganic pigments such as Bengala, bitumen, titanium oxide, fast yellow, disazo yellow, pyrazolone red, chelate red, brilliant carmine, paraffin Examples thereof include azo pigments such as brown, phthalocyanine pigments such as copper phthalocyanine and metal-free phthalocyanine, and condensed polycyclic pigments such as flavantron yellow, dibromoanthrone orange, perylene red, quinacridone red, and dioxazine violet. Chrome Yellow, Hansa Yellow, Benzidine Yellow, Slen Yellow, Quinoline Yellow, Permanent Orange GTR, Pyrarozone Orange, Vulcan Orange, Watch Young Red, Permanent Red, Dupont Oil Red, Resol Red, Rhodamine B Lake, Lake Red C, Rose Bengal, aniline blue, ultramarine blue, calco oil blue, methylene blue chloride, phthalocyanine blue, phthalocyanine green, malachite green oxalate, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 57: 1, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 17, C.I. I. Pigment blue 15: 1, C.I. I. Examples thereof include various pigments such as CI Pigment Blue 15: 3, and these can be used alone or in combination of two or more.

  Examples of the release agent include natural waxes such as carnauba wax, rice wax, and candelilla wax, low molecular weight polypropylene, low molecular weight polyethylene, sazol wax, microcrystalline wax, Fischer-Tropsch wax, paraffin wax, and montan wax. Examples thereof include, but are not limited to, synthetic or mineral / petroleum waxes, ester waxes such as fatty acid esters and montanic acid esters. 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.

  In addition, various components such as an internal additive, a charge control agent, inorganic powder (inorganic particles), and organic particles can be added as necessary. Examples of the internal additive include metals such as ferrite, magnetite, reduced iron, cobalt, nickel and manganese, alloys, and magnetic materials such as compounds containing these metals. 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 include all inorganic particles used as an external additive on the toner surface. Moreover, as a flocculant, besides a surfactant, an inorganic salt or a divalent or higher metal salt can be suitably used. In particular, when a metal salt is used, it is preferable in characteristics such as cohesion control and toner chargeability.

  The volume average particle diameter of the toner in the exemplary embodiment is preferably 1 to 12 μm, more preferably 3 to 9 μm, and more preferably 3 to 8 μm. Further, the number average particle diameter of the toner of the present exemplary embodiment is preferably 1 to 10 μm, and more preferably 2 to 8 μm. If the particle size is too small, not only the production becomes unstable, but also the protrusion structure is difficult to control, the chargeability becomes insufficient, the developability may be lowered, and if it is too large, the resolution of the image is lowered. To do.

[Developer for electrostatic charge development]
The toner obtained by the method for producing an electrostatic charge developing toner of the present invention described above is used as an electrostatic charge developer. The developer is not particularly limited except that it contains the electrostatic image developing toner, and can have an appropriate component composition depending on the purpose. When the electrostatic image developing toner is used alone, it is prepared as a one-component electrostatic image developer, and when used in combination with a carrier, it is prepared as a two-component electrostatic image developer.

  The carrier is not particularly limited, and examples thereof include known carriers. For example, known carriers such as resin-coated carriers described in JP-A-62-39879, JP-A-56-11461, etc. Can be used.

  Specific examples of the carrier include the following resin-coated carriers. That is, examples of the core particle of the carrier include normal iron powder, ferrite, magnetite molding, and the like, and the average particle size is about 30 to 200 μm. Examples of the coating resin for the core particles include styrenes such as styrene, parachlorostyrene, and α-methylstyrene, methyl acrylate, ethyl acrylate, n-propyl acrylate, lauryl acrylate, and 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 vinyls such as vinyl methyl ketone, vinyl ethyl ketone and vinyl isopropenyl ketone Luketones, polyolefins such as ethylene and propylene, silicones such as methylsilicone and methylphenylsilicone, and vinylidene fluoride. Examples thereof include copolymers of vinyl-based fluorine-containing monomers such as tetrafluoroethylene hexafluoroethylene, polyesters containing bisphenol, glycol, etc., epoxy resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and the like. These resins may be used alone or in combination of two or more. The amount of the coating resin is about 0.1 to 10 parts, preferably 0.5 to 3.0 parts by weight with respect to the carrier. For the manufacture 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. it can.

  The mixing ratio between the electrostatic image developing toner and the carrier in the electrostatic image developer is not particularly limited and may be appropriately selected depending on the purpose.

[Image forming apparatus]
Next, the image forming apparatus of the present embodiment will be described.

  FIG. 1 is a schematic diagram illustrating a configuration example of an image forming apparatus for forming an image by the image forming method of the present embodiment. In the illustrated image forming apparatus 200, four electrophotographic photosensitive members 401 a to 401 d are disposed in parallel in the housing 400 along the intermediate transfer belt 409. The electrophotographic photoreceptors 401a to 401d form, for example, images in which the electrophotographic photoreceptor 401a is yellow, the electrophotographic photoreceptor 401b is magenta, the electrophotographic photoreceptor 401c is cyan, and the electrophotographic photoreceptor 401d is black. Is possible.

  Each of the electrophotographic photosensitive members 401a to 401d can be rotated in a predetermined direction (counterclockwise on the paper surface), and the charging rolls 402a to 402d, the developing devices 404a to 404d, and the primary transfer roll 410a along the rotation direction. To 410d and cleaning blades 415a to 415d are arranged. Each of the developing devices 404a to 404d can be supplied with toner of four colors of black, yellow, magenta and cyan accommodated in the toner cartridges 405a to 405d, and the primary transfer rolls 410a to 410d are respectively intermediate transfer belts. 409 is in contact with the electrophotographic photoreceptors 401a to 401d.

  Further, an exposure device 403 is disposed at a predetermined position in the housing 400, and it becomes possible to irradiate the surfaces of the charged electrophotographic photoreceptors 401a to 401d with a light beam emitted from the exposure device 403. ing. Accordingly, charging, exposure, development, primary transfer, and cleaning are sequentially performed in the rotation process of the electrophotographic photosensitive members 401a to 401d, and the toner images of the respective colors are transferred onto the intermediate transfer belt 409 in an overlapping manner.

  Here, the charging rolls 402a to 402d contact the surface of the electrophotographic photoreceptors 401a to 401d with a conductive member (charging roll), and apply a voltage uniformly to the photoreceptor to charge the photoreceptor surface to a predetermined potential. (Charging process). In addition to the charging roll shown in this embodiment, charging by a contact charging method may be performed using a charging brush, a charging film, a charging tube, or the like. Moreover, you may charge by the non-contact system using a corotron or a scorotron.

  As the exposure apparatus 403, an optical system apparatus or the like that can expose a light source such as a semiconductor laser, an LED (light emitting diode), a liquid crystal shutter, or the like on the surfaces of the electrophotographic photosensitive members 401a to 401d can be used. Among these, when an exposure apparatus capable of exposing non-interference light is used, interference fringes between the electroconductive substrates of the electrophotographic photoreceptors 401a to 401d and the photosensitive layer can be prevented.

  As the developing devices 404a to 404d, a general developing device that develops the two-component electrostatic image developer in contact or non-contact with the developer can be used (developing step). Such a developing device is not particularly limited as long as a two-component electrostatic image developing developer is used, and a known one can be appropriately selected according to the purpose. In the primary transfer process, a primary transfer bias having a polarity opposite to that of the toner carried on the image carrier is applied to the primary transfer rolls 410a to 410d, so that each color toner is transferred from the image carrier to the intermediate transfer belt 409. The primary transfer is performed sequentially.

  The cleaning blades 415a to 415d are for removing residual toner adhering to the surface of the electrophotographic photosensitive member after the transfer process, and the electrophotographic photosensitive member cleaned by this cleaning process is repeatedly used in the above-described image forming process. Is done. Examples of the material for the cleaning blade include urethane rubber, neoprene rubber, and silicone rubber.

  The intermediate transfer belt 409 is supported with a predetermined tension by a drive roll 406, a backup roll 408, and a tension roll 407, and can rotate without causing deflection due to the rotation of these rolls. Further, the secondary transfer roll 413 is disposed so as to contact the backup roll 408 via the intermediate transfer belt 409.

  By applying a secondary transfer bias having a reverse polarity to the toner on the intermediate transfer member to the secondary transfer roll 413, the toner is secondarily transferred from the intermediate transfer belt to the recording medium. The intermediate transfer belt 409 that has passed between the backup roll 408 and the secondary transfer roll 413 is cleaned by, for example, a cleaning blade 416 disposed near the drive roll 406 or a static eliminator (not shown). It is repeatedly used for the next image forming process. A tray (transfer medium tray) 411 is provided at a predetermined position in the housing 400, and the transfer medium 500 such as paper in the tray 411 is transferred to the intermediate transfer belt 409 and the secondary transfer roll by the transfer roll 412. Then, the paper is sequentially transferred between the two fixing rolls 414 that are in contact with each other and the two fixing rolls 414, and then discharged to the outside of the housing 400.

  The image forming method of the present embodiment uses a latent image forming step of forming an electrostatic latent image on the surface of the latent image holding member and a developer carried on the developer carrying member, and is formed on the surface of the latent image holding member. A developing step of developing the electrostatic latent image formed to form a toner image, a transfer 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 transfer to the surface of the transfer target And a fixing step for thermally fixing the toner image, wherein the developer is at least a developer containing the electrostatic charge developing toner of the present invention. 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.

  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 adhered to the electrostatic latent image in contact with or in proximity to a developing roll having a developer layer formed on the surface, thereby forming a toner image on the electrophotographic photosensitive member (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 device, and a final toner image is formed.

  In the heat fixing by the fixing machine, a release agent is usually supplied to a fixing member in the fixing machine in order to prevent an offset or the like.

  The method for supplying the release agent to the surface of the roller or belt, which is a fixing member used for heat fixing, is not particularly limited. For example, a pad method using a pad impregnated with a liquid release agent, a web method, a roller method. Non-contact shower method (spray method) and the like, and the web method and the roller method are particularly preferable. These methods are advantageous in that the release agent can be supplied uniformly and it is easy to control the supply amount. In order to supply the release agent uniformly to the entire fixing member by the shower method, it is necessary to use a separate blade or the like.

[Preferred embodiment]
(I) a step of polymerizing a polymerizable monomer containing a polymerizable monomer having a vinyl double bond in an aqueous solvent to obtain a resin particle dispersion for toner base particles, and the resin particle dispersion for toner base particles A step of mixing and dispersing a part of the liquid, a colorant particle dispersion liquid in which at least a colorant is dispersed, and a release agent particle dispersion liquid in which a release agent is optionally dispersed to obtain a mixed liquid; a toner; A polymerizable monomer containing a polymerizable monomer having a vinyl double bond of the same type or different from the polymerizable monomer having a vinyl double bond constituting the mother particle resin in an aqueous solvent And a step of obtaining a resin particle dispersion for protrusions for forming a resin composition protrusion by polymerizing and crosslinking, and the remaining resin particle dispersion for protrusions and the resin particle dispersion for toner base particles in the mixed liquid. Adding the toner base particle resin particles; After the colorant particles and the release agent particles to form aggregated particles and resin particles are aggregated projections, it is a manufacturing method of a step of fusing the aggregated particles by heating.

  (Ii) The weight ratio of the binder resin obtained by polymerizing the monomer in the resin composition protrusion and the crosslinking agent used for crosslinking the binder resin is determined by polymerizing the monomer. The toner for developing an electrostatic charge image is 0.2 to 5 parts by weight with respect to 100 parts by weight of the obtained binder resin.

  (Iii) When the surface area of the toner base particles is 100, the ratio of the surface area occupied by the resin composition protrusions is 4 to 80.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by these.

  First, in this example, each measurement was performed as follows.

-Method for measuring outer diameter ra of resin composition protrusion-
The toner is observed with a scanning electron microscope (SEM), an average value of 50 resin composition protrusions is obtained, and an average value of the outer diameters of the resin composition protrusions is defined as ra. On the other hand, the volume average particle diameter D50 of the toner base particles will be described in the following particle diameter measuring method.

-Method of calculating solubility parameter-
The calculation method is as described above.

-Particle size and particle size distribution measurement method-
The particle size (also referred to as “particle size”) and particle size distribution measurement (also referred to as “particle size distribution measurement”) will be described.

  When the particle diameter to be measured was 2 μm or more, Coulter Multisizer-II type (manufactured by Beckman-Coulter) was used as the measuring apparatus, and ISOTON-II (manufactured by Beckman-Coulter) was used as the electrolyte.

  As a measurement method, 0.5 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 was added to 100 ml of the electrolytic solution.

  The electrolyte 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 2 to 60 μm is measured using the Coulter counter TA-II type with an aperture diameter of 100 μm. Volume average distribution and number average distribution were determined. The number of particles to be measured was 50,000.

  The particle size distribution of the toner was determined by the following method. For the particle size range (channel) obtained by dividing the measured particle size distribution, draw the volume cumulative distribution from the smaller particle size, define the cumulative volume particle size to be 16% cumulative as D16v, and the cumulative volume to be 50% cumulative The particle size is defined as D50v. Further, the cumulative volume particle size that is 84% cumulative is defined as D84v.

The volume average particle size in the present invention is D50v, and the volume average particle size index GSDv is calculated by the following equation.
Formula: GSDv = {(D84v) / (D16v)} ^0.5

  Moreover, when the particle diameter to measure was less than 2 micrometers, it measured using the laser diffraction type particle size distribution measuring apparatus (LA-700: made by Horiba, Ltd.). As a measurement method, a sample in a dispersion is adjusted to have a solid content of about 2 g, and ion exchange water is added thereto to make about 40 ml. This is put into the cell until an appropriate concentration is reached, waits for about 2 minutes, and is measured when the concentration in the cell becomes almost stable. The obtained volume average particle diameter for each channel was accumulated from the smaller volume average particle diameter, and the volume average particle diameter was determined to be 50%.

  When measuring powders such as external additives, 2 g of a measurement sample is added to 50 ml of a 5% aqueous solution of a surfactant, preferably sodium alkylbenzenesulfonate, and 2 with an ultrasonic disperser (1,000 Hz). A sample was prepared by dispersing for a minute, and the measurement was performed in the same manner as the above dispersion.

-Method of measuring toner shape factor SF1-
The shape factor SF1 of the toner is a shape factor SF indicating the degree of unevenness on the toner particle surface, and was calculated by the following equation.
Formula: SF1 = (ML ² / A) × (π / 4) × 100
In the formula, ML represents the maximum length of toner particles, and A represents the projected area of the particles. For the measurement of the shape factor SF1, first, an optical microscope image of toner dispersed on a slide glass was taken into an image analysis device through a video camera, and SF was calculated for 50 or more toners to obtain an average value.

-Measuring method of glass transition temperature-
The glass transition temperature of the toner was determined by DSC (Differential Scanning Calorimetry) measurement method, and was determined from the main maximum peak measured according to ASTM D3418-8.

  DSC-7 manufactured by Perkin Elmer Co. can be used for measurement of the main maximum peak. The temperature correction of the detection part of this apparatus uses the melting point of indium and zinc, and the correction of heat quantity uses the heat of fusion of indium. As the sample, an aluminum pan was used, an empty pan was set as a control, and the measurement was performed at a heating rate of 10 ° C./min.

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

  Although the more specific comparative example and Example in this invention are demonstrated below, the following Examples do not limit the content of this invention at all. In the following description, “parts” means “parts by weight” unless otherwise specified.

[Evaluation of toner production examples and developers]
-Resin particle dispersion for toner base particles-
Styrene 74 parts by weight n-butyl acrylate 23 parts by weight Acrylic acid 3 parts by weight Dodecanethiol 4 parts by weight Carbon tetrabromide 1 part by weight (above, manufactured by Wako Pure Chemical Industries, Ltd.)
6 parts of nonionic surfactant (Nonipol 400: manufactured by Sanyo Chemical Co., Ltd.) and anionic surfactant (Neogen SC: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 10 Emulsion polymerization was carried out in a flask in which parts by weight were dissolved in 550 parts by weight of ion-exchanged water, and 50 parts by weight of ion-exchanged water in which 4 parts by weight of ammonium persulfate was dissolved was added thereto while slowly mixing for 10 minutes. After carrying out nitrogen substitution, the inside of the flask was stirred and heated in an oil bath until the contents reached 70 ° C., and emulsion polymerization was continued for 5 hours. As a result, a resin particle dispersion was obtained in which resin particles for toner base particles of 200 nm, Tg = 58 ° C., and weight average molecular weight Mw = 12000 were dispersed.

-Preparation of colorant dispersion-
Carbon black (Mogal L: manufactured by Cabot) 60 parts by weight Nonionic surfactant (Nonipol 400: manufactured by Sanyo Chemical Co., Ltd.) 6 double-distilled parts ion-exchanged water 240 parts by weight The above components are mixed, dissolved, and homogenized ( Ultra-Turrax T50: made by IKA) for 10 minutes, and then dispersed with an optimizer to prepare a colorant dispersant in which colorant (carbon black) particles having an average particle size of 250 nm are dispersed. did.

-Adjustment of release agent dispersion-
100 parts by weight of paraffin wax (HNP0190: Nippon Seiwa Co., Ltd., melting point 85 ° C.)
Cationic surfactant (Sanisol B50: manufactured by Kao Corporation) 5 parts by weight ion-exchanged water 240 parts by weight Using the above ingredients in a round stainless steel flask, a homogenizer (Ultra Turrax T50: manufactured by IKA) And then dispersed with a pressure discharge type homogenizer to prepare a release agent dispersion in which release agent particles having an average particle diameter of 520 nm are dispersed.

-Preparation of resin particle dispersion 1 for protrusions-
Acrylic acid 80 parts by weight n-butyl acrylate 20 parts by weight Dodecanethiol 3 parts by weight Glycidyl methacrylate 2 parts by weight (manufactured by Wako Pure Chemical Industries, Ltd.)
A mixture obtained by mixing and dissolving the above components was mixed with 12 parts of a nonionic surfactant (Sanyo Kasei Co., Ltd .: Nonipol 400) and an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 8 Add 8 parts by weight of ammonium persulfate (manufactured by Wako Pure Chemical Industries, Ltd.) while adding 10 parts by weight to a solution dissolved in 610 parts by weight of ion-exchanged water, dispersing in a flask, emulsifying, and slowly mixing for 10 minutes. 50 parts by weight of ion-exchanged water was added, and nitrogen substitution was performed at 0.1 liter / min for 20 minutes. Then, while stirring in the flask, the contents are heated in an oil bath until the content reaches 70 ° C., and emulsion polymerization is continued as it is for 5 hours. The resin particles for protrusions have a volume average particle size of 200 nm and a solid content concentration of 40%. Dispersion 1 was prepared. When a part of the dispersion was left on an oven at 100 ° C. to remove moisture, DSC (differential scanning calorimeter) measurement was performed. The glass transition temperature was 63 ° C. and the weight average molecular weight was 42,000. Met.

-Preparation of resin particle dispersion 2 for protrusions-
Acrylic acid 82 parts by weight n-butyl acrylate 28 parts by weight Dodecanethiol 2 parts by weight Allyl glycidyl ether 1.5 parts by weight (Wako Pure Chemical Industries, Ltd.)
A mixture obtained by mixing and dissolving the above components was mixed with 12 parts of a nonionic surfactant (Sanyo Kasei Co., Ltd .: Nonipol 400) and an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 8 Add 8 parts by weight of ammonium persulfate (manufactured by Wako Pure Chemical Industries, Ltd.) while adding 10 parts by weight to a solution dissolved in 610 parts by weight of ion-exchanged water, dispersing in a flask, emulsifying, and slowly mixing for 10 minutes. 50 parts by weight of ion-exchanged water was added, and nitrogen substitution was performed at 0.1 liter / min for 20 minutes. Then, while stirring in the flask, the contents are heated in an oil bath until the content reaches 70 ° C., and emulsion polymerization is continued as it is for 5 hours. The resin particles for protrusions have a volume average particle size of 200 nm and a solid content concentration of 40%. Dispersion 2 was prepared. When a part of the dispersion was left in an oven at 100 ° C. to remove moisture, DSC (differential scanning calorimeter) measurement was performed. As a result, the glass transition temperature was 67 ° C. and the weight average molecular weight was 52,000. Met.

-Preparation of resin particle dispersion 3 for protrusions-
Acrylic acid 80 parts by weight n-butyl acrylate 20 parts by weight Dodecanethiol 10 parts by weight Divinyl adipate 1.6 parts by weight (Wako Pure Chemical Industries, Ltd.)
A mixture obtained by mixing and dissolving the above components was mixed with 12 parts of a nonionic surfactant (Sanyo Kasei Co., Ltd .: Nonipol 400) and an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 8 Add 8 parts by weight of ammonium persulfate (manufactured by Wako Pure Chemical Industries, Ltd.) while adding 10 parts by weight to a solution dissolved in 610 parts by weight of ion-exchanged water, dispersing in a flask, emulsifying, and slowly mixing for 10 minutes. 50 parts by weight of ion-exchanged water was added, and nitrogen substitution was performed at 0.1 liter / min for 20 minutes. Then, while stirring in the flask, the contents are heated in an oil bath until the content reaches 70 ° C., and emulsion polymerization is continued as it is for 5 hours. The resin particle for protrusions has a volume average particle size of 300 nm and a solid content concentration of 40%. Dispersion 3 was prepared. When a part of the dispersion was left in an oven at 100 ° C. to remove moisture, DSC (differential scanning calorimeter) measurement was performed. As a result, the glass transition temperature was 58 ° C. and the weight average molecular weight was 55,000. Met.

-Preparation of resin particle dispersion 4 for protrusions-
Methyl acrylate 100 parts by weight Dodecanethiol 10 parts by weight Carbon tetrabromide 4 parts by weight (above, manufactured by Wako Pure Chemical Industries, Ltd.)
A mixture obtained by mixing and dissolving the above components was mixed with 12 parts of a nonionic surfactant (Sanyo Kasei Co., Ltd .: Nonipol 400) and an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 8 Add 8 parts by weight of ammonium persulfate (manufactured by Wako Pure Chemical Industries, Ltd.) while adding 10 parts by weight to a solution dissolved in 610 parts by weight of ion-exchanged water, dispersing in a flask, emulsifying, and slowly mixing for 10 minutes. 50 parts by weight of ion-exchanged water was added, and nitrogen substitution was performed at 0.1 liter / min for 20 minutes. Then, while stirring in the flask, the contents are heated in an oil bath until the content reaches 70 ° C., and emulsion polymerization is continued as it is for 5 hours. The resin particles for protrusions have a volume average particle size of 200 nm and a solid content concentration of 40%. Dispersion 4 was prepared. When a part of the dispersion was left in an oven at 100 ° C. to remove moisture, DSC (differential scanning calorimeter) measurement was performed. As a result, the glass transition temperature was 100 ° C. and the weight average molecular weight was 42,000. Met.

-Preparation of resin particle dispersion 5 for protrusions-
Styrene 84 parts by weight Acrylic acid 4 parts by weight n-Butyl acrylate 12 parts by weight Dodecanethiol 4 parts by weight Carbon tetrabromide 4 parts by weight (manufactured by Wako Pure Chemical Industries, Ltd.)
A mixture obtained by mixing and dissolving the above components was mixed with 12 parts of a nonionic surfactant (Sanyo Kasei Co., Ltd .: Nonipol 400) and an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 8 Add 8 parts by weight of ammonium persulfate (manufactured by Wako Pure Chemical Industries, Ltd.) while adding 10 parts by weight to a solution dissolved in 610 parts by weight of ion-exchanged water, dispersing in a flask, emulsifying, and slowly mixing for 10 minutes. 50 parts by weight of ion-exchanged water was added, and nitrogen substitution was performed at 0.1 liter / min for 20 minutes. Then, while stirring in the flask, the contents are heated in an oil bath until the content reaches 70 ° C., and emulsion polymerization is continued as it is for 5 hours. The resin particles for protrusions have a volume average particle size of 200 nm and a solid content concentration of 40%. Dispersion 5 was prepared. When a part of the dispersion was left in an oven at 100 ° C. to remove moisture, DSC (differential scanning calorimeter) measurement was performed. As a result, the glass transition temperature was 63 ° C. and the weight average molecular weight was 32,000. Met.

-Preparation of resin particle dispersion 6 for protrusions-
Acrylic acid 85 parts by weight n-butyl acrylate 13 parts by weight Dodecanethiol 2 parts by weight Glycidyl methacrylate 2 parts by weight (manufactured by Wako Pure Chemical Industries, Ltd.)
A mixture obtained by mixing and dissolving the above components was mixed with 12 parts of a nonionic surfactant (Sanyo Kasei Co., Ltd .: Nonipol 400) and an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 8 Add 8 parts by weight of ammonium persulfate (manufactured by Wako Pure Chemical Industries, Ltd.) while adding 10 parts by weight to a solution dissolved in 610 parts by weight of ion-exchanged water, dispersing in a flask, emulsifying, and slowly mixing for 10 minutes. 50 parts by weight of ion-exchanged water was added, and nitrogen substitution was performed at 0.1 liter / min for 20 minutes. Then, while stirring in the flask, the contents are heated in an oil bath until the content reaches 70 ° C., and emulsion polymerization is continued as it is for 2 hours. The resin particles for protrusions have a volume average particle size of 100 nm and a solid content concentration of 40%. Dispersion 6 was prepared. When a part of the dispersion was left on an oven at 100 ° C. to remove moisture, DSC (differential scanning calorimeter) measurement was performed. As a result, the glass transition temperature was 53 ° C. and the weight average molecular weight was 32,000. Met.

-Preparation of resin particle dispersion 7 for protrusions-
Acrylic acid 70 parts by weight n-butyl acrylate 28 parts by weight Dodecanethiol 10 parts by weight Glycidyl methacrylate 2 parts by weight (above, manufactured by Wako Pure Chemical Industries, Ltd.)
A mixture obtained by mixing and dissolving the above components was mixed with 12 parts of a nonionic surfactant (Sanyo Kasei Co., Ltd .: Nonipol 400) and an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 8 Add 8 parts by weight of ammonium persulfate (manufactured by Wako Pure Chemical Industries, Ltd.) while adding 10 parts by weight to a solution dissolved in 610 parts by weight of ion-exchanged water, dispersing in a flask, emulsifying, and slowly mixing for 10 minutes. 50 parts by weight of ion-exchanged water was added, and nitrogen substitution was performed at 0.1 liter / min for 20 minutes. Thereafter, the contents in the flask are heated in an oil bath until the content reaches 70 ° C. while stirring, and the emulsion polymerization is continued for 7 hours. The resin particles for protrusions have a volume average particle size of 350 nm and a solid content concentration of 40%. Dispersion 7 was prepared. When a part of the dispersion was left on an oven at 100 ° C. to remove moisture, DSC (differential scanning calorimeter) measurement was performed. As a result, the glass transition temperature was 53 ° C. and the weight average molecular weight was 32,000. Met.

-Production of Toner 1-
320 parts by weight of toner base particle resin fine particle dispersion
Colorant dispersion 80 parts by weight Release agent particle dispersion 96 parts by weight Aluminum sulfate (manufactured by Wako Pure Chemical Industries, Ltd.) 1.5 parts by weight Ion-exchanged water 1270 parts by weight In the round stainless steel flask After mixing and dispersing using a homogenizer (Ultra Turrax T50: manufactured by IKA), the flask was heated to 50 ° C. while stirring in the oil bath for heating. After maintaining at 50 ° C. for 30 minutes, it was confirmed that aggregated particles having a D50 of 4.8 μm were formed. Further, a mixture of 30 parts by weight of the above toner mother particle resin fine particle dispersion and 20 parts by weight of the protrusion resin particle dispersion 1 was added, and the temperature of the heating oil bath was further raised at 50 ° C. for 30 minutes. Holding, creating an aggregate, adding a dispersion containing the aggregate particles, 1N sodium hydroxide, adjusting the pH of the system to 7.0, sealing the stainless steel flask, and using a magnetic seal The mixture was heated to 90 ° C. while stirring was continued for 4 hours. After cooling, the toner base particles were separated by filtration, washed four times with ion exchange water, and then freeze-dried to obtain toner particles 1. The toner base particles had a volume average particle diameter D50 of 5.8 μm and a shape factor SF1 of 115. When this was observed with an SEM, it was found that protrusions having a height of 120 nm (ra / D50 = 0.02) were formed on the surface of the toner base particles.

-Production of Toner 2-
Toner particles 2 were prepared in the same manner as toner 1 except that the protrusion resin particle dispersion 1 was changed to the protrusion resin particle dispersion 2. The toner base particles had a volume average particle diameter D50 of 5.6 μm and a shape factor SF1 of 118. When this was observed with an SEM, it was found that protrusions having a height of 170 nm (ra / D50 = 0.03) were formed on the surface of the toner base particles.

-Production of Toner 3-
Toner particles 3 were prepared in the same manner as toner 1 except that the protrusion resin particle dispersion 1 was changed to the protrusion resin particle dispersion 3. The toner base particles had a volume average particle diameter D50 of 5.9 μm and a shape factor SF1 of 117. When this was observed with an SEM, it was found that protrusions having a height of 190 nm (ra / D50 = 0.005) were formed on the surface of the toner base particles.

-Production of Toner 4-
Toner particles 4 were prepared in the same manner as toner 1 except that the protrusion resin particle dispersion 1 was changed to the protrusion resin particle dispersion 4. The toner base particles had a volume average particle diameter D50 of 5.6 μm and a shape factor SF1 of 115. When this was observed with an SEM, no protrusions were formed although there were adhered resin particles on the surface of the toner base particles.

-Production of Toner 5-
Toner particles 5 were prepared in the same manner as toner 1 except that the protrusion resin particle dispersion 1 was changed to the protrusion resin particle dispersion 5. The toner base particles had a volume average particle diameter D50 of 6 μm and a shape factor SF1 of 115. When this was observed with an SEM, no protrusions were formed on the surface of the toner base particles.

-Production of Toner 6-
Toner particles 6 were prepared in the same manner as toner 1 except that the protrusion resin particle dispersion 1 was changed to the protrusion resin particle dispersion 6. The toner base particles had a volume average particle diameter D50 of 5.8 μm and a shape factor SF1 of 121. When this was observed by SEM, it was found that protrusions having a height of 55 nm (ra / D50 = 0.01) were formed on the surface of the toner base particles.

-Production of Toner 7-
Toner particles 7 were prepared in the same manner as toner 1 except that the protrusion resin particle dispersion 1 was changed to the protrusion resin particle dispersion 7. The toner base particles had a volume average particle diameter D50 of 5.2 μm and a shape factor SF1 of 115. When this was observed with an SEM, it was found that protrusions having a height of 240 nm (ra / D50 = 0.04) were formed on the surface of the toner base particles.

-Preparation and Evaluation of Developers 1-7-
1 part of colloidal silica (manufactured by Nippon Aerosil Co., Ltd., R972) is externally added to 100 parts of each of the obtained toner particles 1 to 7 and mixed using a Henschel mixer. 7 was obtained. Furthermore, 100 parts of ferrite particles (manufactured by Powdertech, volume average particle size 50 μm) and 1 part of methacrylate resin (manufactured by Mitsubishi Rayon Co., Ltd., molecular weight 95000) were placed in a pressure kneader together with 500 parts of toluene, and mixed at room temperature for 15 minutes. Thereafter, the temperature was raised to 70 ° C. while mixing under reduced pressure, and toluene was distilled off, followed by cooling and sizing using a 105 μm sieve to produce a ferrite carrier (resin-coated carrier). The ferrite carrier and the electrostatic image developing toners 1 to 7 were mixed to prepare two-component electrostatic image developer 1 to 7 having a toner concentration of 7% by weight. The electrostatic charge image developers 1 to 3 were used for Examples 1 to 3, respectively, and the electrostatic charge image developers 4 to 7 were used for Comparative Examples 1 to 4, respectively.

(Evaluation of image fog)
Using the Fuji Xerox DocuCentreColor 400CP remodeling machine as shown in FIG. 1, the adjusted developer is adjusted to a toner paper amount of 6 g / cm ² on a 10 cm front edge of the image on a Fuji Xerox color paper (J paper). went. After output, using an external fixing device, fixing is performed at a peripheral speed of a developer holding body that holds the developer provided in the developing devices 404a to 404d at 1000 mm / sec, 1300 mm / sec, 1600 mm / sec, and 1900 mm / sec. did. The fog of 10 cm portion from the rear end of the solid portion of the image after printing 1,000 sheets was visually confirmed and evaluated according to the following evaluation criteria.
A: Image fogging is not recognized at all.
○: Slight image fogging but no practical problem.
Δ: Slight image fogging is recognized but is in an allowable range.
X: Image fogging is recognized.

(Filming evaluation)
A print test was performed on 5,000 sheets and 10,000 sheets in an environment of 28 ° C. and 85% RH using a modified DocuCentreColor400 (manufactured by Fuji Xerox Co., Ltd.). Thereafter, the appearance of the deposit on the photoreceptor was visually confirmed. The criteria for judgment are as follows.
A: The deposit cannot be confirmed on the photoconductor.
○: Adhering matter can be confirmed on the photoreceptor, but it is slight.
Δ: Deposits grown in a streak pattern on the photoconductor can be confirmed, but slightly x: There are deposits almost all over the photoconductor.

(Evaluation of color streaking)
The prepared developer can change the peripheral speed of the developer holding body holding the developer provided in the developing devices 404a to 404d to 1600 mm / sec in an environment of 28 ° C./85% RH. Using the modified DocuCentreColor400CP machine manufactured by Fuji Xerox shown in FIG. An image was output using 5-1. Evaluation was based on the cumulative number of prints in which color streaks occurred. The results are shown in Table 1.

  From the above results, in Examples 1 to 3, the cleaning characteristics were good without impairing the transferability. On the other hand, in Comparative Examples 1 to 4, color streaks occurred in the transferred image, and in Comparative Example 1, filming also occurred.

  The electrostatic charge developing toner of the present invention is particularly useful for uses such as electrophotography and electrostatic recording.

1 is a schematic diagram illustrating a configuration example of an image forming apparatus used in the present embodiment. FIG. 3 is a schematic diagram of an external structure of toner particles according to the present embodiment.

Explanation of symbols

  200 Image forming apparatus, 401a to 401d electrophotographic photosensitive member, 400 housing, 402a to 402d charging roll, 403 exposure apparatus, 404a to 404d developing apparatus, 405a to 405d toner cartridge, 409 intermediate transfer belt, 410a to 410d primary transfer roll 411 Tray (transfer medium tray), 413 Secondary transfer roll, 414 Fixing roll, 415a to 415d, 416 Cleaning blade, 500 Transfer medium.

Claims (3)

On the surface of the toner, there are resin composition protrusions indicated by an outer diameter ra, the resin composition protrusions have a crosslinked structure, the outer diameter ra of the resin composition protrusions, and the volume average particle diameter D50 of the toner base particles, The relationship between the solubility parameter of the resin composition protrusion and the solubility parameter of the resin composition of the toner base particles is expressed by the following equation (2) and the shape of the toner: A toner for electrostatic charge development, wherein the coefficient SF1 is in the range of 110 to 120.
(Equation 1)
0.01 <ra / D50 <0.04 Formula (1)
In the formula, ra: outer diameter of protrusion of resin composition nm, D50: volume average toner particle diameter nm
1.5 <δa−δ <3 [(cal / ml) ^1/2 / 25 ° C.] Formula (2)
Where δa: resin composition protrusion solubility parameter, δ: toner base particle resin solubility parameter   An electrostatic charge image developing developer comprising the electrostatic charge image developing toner according to claim 1. A latent image forming unit that forms a latent image on the latent image carrier, a developing unit that develops the latent image using a developer for developing an electrostatic charge, and the developed toner image via an intermediate transfer member or not. An image forming apparatus including: a transfer unit that transfers the toner image on the transfer member; and a fixing unit that adds and fixes the toner image on the transfer member.
The image forming apparatus according to claim 2, wherein the developer for developing an electrostatic charge is the developer for developing an electrostatic charge according to claim 2.

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