JP2010038985A - Colorant for toner, toner, and developer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a colorant for toner which has high concealing property, excellent color developing property and coloring property, and constant charging property, and to provide a toner and a developer containing the colorant for toner. <P>SOLUTION: The colorant for toner is made of composite particles, which comprise pigment particles dispersed in a polymer phase containing a structural unit derived from polymerizable crosslinking monomers and a structural unit derived from water-soluble monomers and which have at least one vacancy in the particle. The toner contains at least a binder resin and the colorant for toner. The developer contains the toner and a carrier. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a colorant for toner, a toner, and a developer. More specifically, the present invention relates to a toner colorant having excellent color developability and colorability, a toner containing the toner colorant, and a developer containing the toner.

Conventionally, pigments such as inorganic pigments such as carbon black and titanium oxide, organic pigments such as azo pigments, phthalocyanine pigments and polycyclic pigments are widely used as colorants to be blended in toners used in electrophotography and the like. ing. The toner containing the colorant is generally a toner obtained by using the particles made of the pigment and the binding resin. Recently, a polymer toner obtained by dispersing pigment particles in a polymer obtained by dispersing pigment particles and a monomer in an aqueous medium and emulsion polymerization is known (for example, patent document). 1).
In electrophotography, an electrostatic image is formed on a photoreceptor by charging and exposure, and the electrostatic latent image is developed with a developer containing toner or polymerized toner, and visualized through transfer and fixing.

  Here, when an inorganic pigment or an organic pigment is used as the toner colorant, the charging characteristics differ greatly depending on the pigment, and therefore, different charging control is required depending on the pigment used.

  On the other hand, consisting of a shell wall whose main component is a copolymer obtained by polymerizing a monomer raw material containing a radical polymerizable water-soluble monomer and a radical polymerizable water-insoluble monomer, Hollow polymer particles in which pigments are combined are known (for example, Patent Document 2).

Japanese Patent Laid-Open No. 10-20547 JP 2007-291359 A

  However, since the colorant used in the polymerized toner described in Patent Document 1 simply uses particles made of an inorganic pigment or an organic pigment, the color developability is still insufficient. Further, the hollow polymer particles described in Patent Document 2 have a problem that the content of the coloring compound is low, the color developability is insufficient, and the hollow polymer is easily crushed and easily broken.

  The present invention has been made to solve the above-described problems of the prior art, and improves the concealment of a fixed image by a toner containing a toner colorant, and also has excellent color development and colorability. And a toner that contains the toner colorant and is easy to control the charge, and a developer containing the toner.

The present invention is as follows.
1. A colorant for toner, comprising pigment particles dispersed in a polymer phase, and composite particles having at least one void formed therein.
2. The average particle diameter of the composite particles is 20 nm to 100 μm. The colorant for toner according to 1.
3. The polymer phase constituting at least the surface layer portion of the composite particle includes a structural unit derived from a polymerizable crosslinkable monomer. Or 2. The colorant for toner according to 1.
4). The content of the pigment particles in the composite particles is 3 to 80 parts by mass when the polymer constituting the polymer phase is 100 parts by mass. To 3. The colorant for toner according to any one of the above.
5). The ratio of the total volume occupied by the voids of the composite particles is 5 to 90% by volume when the volume of the entire composite particles is 100% by volume. To 4. The colorant for toner according to any one of the above.
6). 1. The pigment particle according to the above 1., wherein the pigment particles comprise at least one selected from azo pigments, phthalocyanine pigments and polycyclic pigments. To 5. The colorant for toner according to any one of the above.
7). 1. A colorant for polymerized toner. To 6. The colorant for toner according to any one of the above.
8). In a toner containing at least a binder resin and a colorant, the colorant is To 6. A toner characterized by being a colorant for toner according to any one of the above.
9. The plurality of toner colorants are bound by a binding portion made of the binding resin. The toner described in 1.
10. Above 8. Or 9. A developer comprising the toner and the carrier described in 1 above.

The colorant for toner of the present invention is composed of composite particles in which pigment particles are dispersed in a polymer phase and at least one void is formed therein, thereby improving the concealability of a fixed image by a hollow structure. And excellent color development and colorability. Further, by making composite particles having a polymer phase, a constant chargeability can be obtained regardless of the color type. Furthermore, the compatibility with the binder resin is improved, and the dispersibility in the toner is excellent.
In addition, when the average particle size of the composite particles is 20 nm to 100 μm, it is possible to obtain a toner colorant having better dispersibility in the toner.
Further, when the polymer phase constituting at least the surface portion of the composite particle contains a structural unit derived from a polymerizable crosslinkable monomer, the strength of the polymer phase is improved and the toner has excellent durability. It can be a colorant.
Further, when the content of the pigment particles in the composite particles is 3 to 80 parts by mass when the polymer constituting the polymer phase is 100 parts by mass, the coloring for toner having excellent color developability It can be used as an agent.
Further, when the ratio of the total volume occupied by the voids of the composite particles is 5 to 90% by volume when the total volume of the composite particles is 100% by volume, the concealability of the fixed image is further improved. Thus, a colorant for toner having excellent color developability and colorability can be obtained.
Further, when the pigment particles are made of at least one selected from an azo pigment, a phthalocyanine pigment, and a polycyclic pigment, a colorant for toner having excellent color developability can be obtained.
Furthermore, since the toner of the present invention contains the colorant for toner of the present invention, it is excellent in color developability and colorability and also in the concealment of a fixed image.
Furthermore, the developer of the present invention contains the toner of the present invention, so that the charging characteristics are stabilized. Moreover, it can be set as the developing agent which is excellent in the color development of an image and the quality of printed matter is stabilized.

  Hereinafter, the present invention will be described in detail. In the present specification, “(meth) acryl” means acryl and methacryl, and “(meth) acrylate” means acrylate and methacrylate. The “average particle diameter” refers to the average value of the particle diameters measured for 100 particles present in the observation field, with the major axis of the measurement target particles observed using a transmission electron microscope as the particle diameter. .

[1] Toner Colorant The toner colorant of the present invention is a composite particle (hereinafter referred to as “hollow particle”) in which pigment particles are dispersed in a polymer phase and at least one void is formed therein. It may be said).

The polymer constituting the polymer phase is preferably a structural unit derived from a polymerizable crosslinkable monomer (hereinafter referred to as “structural unit (a)”), and a water-soluble polymer having a polymerizable property. It is a polymer containing a structural unit derived from a monomer (hereinafter referred to as “structural unit (b)”) and, if necessary, referred to as another structural unit (hereinafter referred to as “structural unit (c)”). ) May further be contained. By containing structural unit (a) and (b), the intensity | strength of a polymer phase improves and the crack and crushing of a composite particle can be suppressed.
Moreover, by containing the said structural unit (a), abrasion resistance is good, it is hard to be crushed, and it is excellent in durability. Thus, since it is excellent in durability, the space | gap in a composite particle becomes difficult to be crushed.
Further, by containing the structural unit (b), since the polymerization stability is excellent, the void formation in the composite particles is excellent.

  The polymerizable crosslinkable monomer (hereinafter also referred to as “polymerizable crosslinkable monomer”) that forms the structural unit (a) is preferably a polyfunctional unsaturated compound such as divinyl. Benzene, trivinylbenzene, ethylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, allyl (meth) acrylate, Examples include ethylene di (meth) acrylate, diethylene di (meth) acrylate, triethylene di (meth) acrylate, propylene di (meth) acrylate, dipropylene di (meth) acrylate, diallyl phthalate, and triallyl cyanurate. These compounds can be used alone or in combination of two or more. Of these, divirbenzene, ethylene glycol dimethacrylate and trimethylolpropane trimethacrylate are preferred. The structural unit (a) formed by using divirbenzene, ethylene glycol dimethacrylate and trimethylolpropane trimethacrylate shortens the molecular weight between crosslinking points and improves the crosslinking density.

  The content of the structural unit (a) constituting the polymer is preferably 3 to 70% by mass, and 5 to 60% by mass when the total structural unit in the polymer is 100% by mass. More preferably, it is more preferably 7 to 50% by mass. Since the intensity | strength of a composite particle will improve that the said content rate exists in the said range, the crack and crushing of particle | grains can be suppressed.

  As the water-soluble monomer having a polymerizable property for forming the structural unit (b), (meth) having a hydroxyl group such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate Acrylic acid ester compound; (meth) acrylic acid ester compound having amino group such as (meth) acrylic acid 2-dimethylaminoethyl, (meth) acrylic acid 2-diethylaminoethyl; (meth) acrylamide, N-methylol (meth) Unsaturated amide compounds such as acrylamide; unsaturated acids such as acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid and cinnamic acid; vinyl ester compounds such as vinyl formate and vinyl acetate; styrene sulfone Examples include acid salts (Na salts). These compounds can be used alone or in combination of two or more.

  The content of the structural unit (b) constituting the polymer is preferably 0.5 to 15.0% by mass when the total structural unit in the polymer is 100% by mass. It is more preferable that it is 7-10 mass%, and it is still more preferable that it is 0.8-8 mass%. When the said content rate is 0.5-15.0 mass%, it is excellent in the formation property of the space | gap in a composite particle.

  As described above, the polymer can further contain a structural unit (c) in addition to the structural unit (a) and the structural unit (b). This structural unit (c) is usually a polymerizable crosslinkable monomer and a monomer copolymerizable with a polymerizable water-soluble monomer (hereinafter referred to as “other monomer”). )).

  The other monomer is preferably a radically polymerizable and non-crosslinkable hydrophobic monomer. For example, aromatic vinyl compound, (meth) acrylic acid alkyl ester compound, alkoxyl group, (meth) acrylic acid ester compound having functional group such as cyano group, vinyl cyanide compound, conjugated diene compound, non-conjugated diene compound, epoxy And group-containing unsaturated compounds.

  Examples of the aromatic vinyl compound include styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, α-methylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, 4-tert-butylstyrene, Examples thereof include tert-butoxystyrene, vinyl toluene, vinyl naphthalene, and vinyl pyridine.

  Examples of the (meth) acrylic acid alkyl ester compound include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, Isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, n-pentyl (meth) acrylate, isoamyl (meth) acrylate, n-hexyl (meth) acrylate, (Meth) acrylic acid 2-methylpentyl, (meth) acrylic acid n-octyl, (meth) acrylic acid 2-ethylhexyl, (meth) acrylic acid n-decyl, (meth) acrylic acid n-dodecyl, (meth) acrylic N-octadecyl acid, cyclohexyl (meth) acrylate, phenyl (meth) acrylate, (meth) Benzyl acrylic acid and the like.

  Examples of the (meth) acrylic acid ester compound having an alkoxyl group include 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2- (n-propoxy) ethyl (meth) acrylate, (meth ) 2- (n-butoxy) ethyl acrylate, 3-methoxypropyl (meth) acrylate, 3-ethoxypropyl (meth) acrylate, 2- (n-propoxy) propyl (meth) acrylate, (meth) acryl Examples include acid 2- (n-butoxy) propyl.

  Examples of the (meth) acrylic acid ester compound having a cyano group include cyanomethyl (meth) acrylate, 1-cyanoethyl (meth) acrylate, 2-cyanoethyl (meth) acrylate, 1-cyanopropyl (meth) acrylate, ( 2-cyanopropyl (meth) acrylate, 3-cyanopropyl (meth) acrylate, 4-cyanobutyl (meth) acrylate, 6-cyanohexyl (meth) acrylate, 2-ethyl-6-cyano (meth) acrylate Examples include hexyl and 8-cyanooctyl (meth) acrylate.

Examples of the vinyl cyanide compound include acrylonitrile, methacrylonitrile, ethacrylonitrile and the like.
Examples of the conjugated diene compound include butadiene, isoprene, chloroprene and the like.
Examples of the non-conjugated diene compound include 1,4-hexadiene and dicyclopentadiene.
Examples of the epoxy group-containing unsaturated compound include glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate, β-ethylglycidyl (meth) acrylate, and 3-methyl-3,4-epoxy (meth) acrylate. Butyl, 3-ethyl-3,4-epoxybutyl (meth) acrylate, 4-methyl-4,5-epoxypentyl (meth) acrylate, 2,3-epoxycyclohexylmethyl (meth) acrylate, (meth) 3,4-epoxycyclohexylmethyl acrylate, o-vinylbenzylglycidyl ether, m-vinylbenzylglycidyl ether, p-vinylbenzylglycidyl ether, 2-vinylcyclohexene oxide, 3-vinylcyclohexene oxide, 4-vinylcyclohexene oxide, allyl Glycidyl ether Etc.
Other vinyl ester compounds such as vinyl propionate; halogen-containing unsaturated compounds such as vinyl chloride and vinylidene chloride; maleimide compounds such as maleimide, N-methylmaleimide, N-butylmaleimide, N-phenylmaleimide, and N-cyclohexylmaleimide Styrenesulfonic acid, α-methylstyrenesulfonic acid; 3-acryloxy-2-hydroxypropanesulfonic acid, 3-methacryloxy-2-hydroxypropanesulfonic acid, 3-acryloxy-1-hydroxypropane-2-sulfonic acid, 3- Methacryloxy-1-hydroxypropane-2-sulfonic acid, 3-allyloxy-2-hydroxypropanesulfonic acid, 2-hydroxy-3-butenesulfonic acid, vinylsulfonic acid, allylsulfonic acid, methallylsulfonic acid, vinylphenol Methane sulfonic acid, iso-amylene sulfonic acids, such as 2-methyl-1,3-butadiene-1-sulfonic acid.

  The content of the structural unit (c) is preferably 15.0 to 96.5% by mass and preferably 20 to 90% by mass when the total structural unit in the polymer is 100% by mass. More preferably, the content is more preferably 25 to 85% by mass. When the said content rate is 15.0-96.5 mass%, it is excellent in the particle formation property during superposition | polymerization.

  Among the above monomers, a more preferable combination of monomers forming the polymer phase of the composite particle in the present invention is that the monomer forming the structural unit (a) is divinylbenzene, and the structural unit (b) Is a unsaturated acid, and the monomer forming the structural unit (c) is an aromatic vinyl compound and / or a (meth) acrylic acid alkyl ester compound. With these combinations, the strength of the composite particles is improved and the dispersibility in the toner is excellent.

  The pigment particles are particles made of a colored compound that does not dissolve in water and an organic solvent. This colored compound may be either an organic compound (organic pigment) or an inorganic compound (inorganic pigment). Organic pigments include insoluble azo pigments, condensed azo pigments, azo lakes, chelate azo pigments, etc .; phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, thioindigo pigments, isoindolinone pigments, quinophthalone pigments And polycyclic pigments such as dye lakes, nitro pigments, nitroso pigments, aniline black, and fluorescent pigments. Of these, azo pigments, phthalocyanine pigments, and polycyclic pigments are preferred. Examples of inorganic pigments include titanium oxide, carbon black, red pepper, cadmium red, molybdenum orange, yellow iron oxide, yellow lead, titanium yellow, chrome green, chromium oxide, cobalt blue, and manganese violet.

  The average particle diameter of the pigment particles is preferably 1 nm to 1 μm, more preferably 1 nm to 500 nm, and still more preferably 5 nm to 50 nm. When the average particle diameter of the pigment particles is in the above range, the dispersibility in the polymer phase is excellent.

  The content of the pigment particles in the toner colorant of the present invention is preferably 3 to 80 parts by mass, more preferably 4 to 75 parts by mass, when the polymer constituting the polymer phase is 100 parts by mass. 5 to 70 parts by mass is more preferable. When the content of the pigment particles is in the above range, the color developability as a colorant is sufficiently expressed.

  The colorant for toner of the present invention is a composite particle having an outer wall (shell) containing the polymer and the pigment particles, and having at least one void inside thereof, and the pigment is uniformly dispersed in the polymer phase. It is a granular material in which the color of the pigment particles is reflected by the composite particles themselves.

The shape of the void is not particularly limited, and may be a sphere, an elliptic sphere, a polyhedron, a linear body, a curved body, or a combination or deformation body thereof. Accordingly, the inner wall surface facing the gap can also have various forms, such as a smooth flat surface, a curved surface, and an uneven surface.
The number of voids in the toner colorant of the present invention may be one or plural. Furthermore, when a plurality of voids are formed, they may be continuous.
The form of the colorant for toner of the present invention is exemplified below.
(1) Composite particles having only one void.
(2) Composite particles having a plurality of voids and isolated from each other.
(3) Composite particles having a plurality of voids and communicating with each other in a linear space or the like.
Examples of the composite particles of this aspect (3) include composite particles having communication holes such as a three-dimensional network inside.

In the toner colorant (composite particles) of the present invention, the ratio of the total volume occupied by the voids, that is, the void ratio is 5 to 5 when the volume of the entire composite particles (the outer shape of the composite particles) is 100% by volume. It is preferably 90% by volume, more preferably 5 to 70% by volume, and still more preferably 6 to 60% by volume. When the porosity is in the above range, the mechanical strength is excellent.
In the present specification, the porosity is arbitrarily selected from 10 particles observed by a transmission electron microscope “H-7650” (manufactured by Hitachi High-Technology Co., Ltd.), and these particles are expressed by the following formula (1). It is a calculated value.
[(Total volume of the void) / {4 [pi] (the outer diameter of the composite particles ^{/ 2) 3/3}]} × 100 (1)
In addition, when there is only one void and the shape is a spherical body, the void ratio can be calculated by the following formula (2).
{(Inner diameter of void) ³ / (Outer diameter of composite particle) ³ } × 100 (2)

  The outer shape of the colorant for toner of the present invention is not particularly limited, and may be a sphere, an elliptic sphere, a polyhedron, or a deformed body thereof. Further, the surface of the toner colorant is not particularly limited, and may be a smooth curved surface, an uneven surface, or the like.

  The average particle diameter of the colorant for toner of the present invention is preferably 20 nm to 100 μm, more preferably 30 nm to 50 μm, still more preferably 50 nm to 10 μm.

The outer wall of the composite particle in the present invention is composed of a polymer phase, and the polymer phase is composed of structural units (a), (b) and (c), or structural units (a) and (b).
Moreover, it is preferable that the surface layer part of the outer wall of a composite particle has a structural unit (a), and also has a structural unit (c). By having these structural units in the surface layer part, the durability and dispersibility are excellent, and when the composite particles are formed, voids can be easily formed in the composite particles.

The composite particles in the present invention have a polymer phase containing the pigment and at least one space filled with a gas when used as a toner colorant. By forming this space, the light incident on the composite particles is scattered on the surface of the composite particles and the inner wall forming the space. Therefore, the colorant for toner of the present invention is excellent in hiding properties and can express light to dark colors regardless of the color of the substrate or the base.
In addition, since the colorant for toner of the present invention is a composite particle in which a pigment is dispersed in a polymer phase, there is no difference in charging property due to the pigment itself, and the toner has a stable charging property and electrical property. It can be a colorant.

  The method for producing the colorant for toner of the present invention is not particularly limited, but the polymer forming the polymer phase is composed of a structural unit (a) derived from a polymerizable crosslinkable monomer, and a polymerizable property. And a structural unit (b) derived from a water-soluble monomer having a water-soluble monomer.

  A preferred method for producing the colorant for toner of the present invention is an aqueous dispersion containing pigment particles, a monomer component (i) mainly containing a non-crosslinkable hydrophobic monomer, and a dispersion medium containing water. The step of preparing the emulsion (hereinafter referred to as “first step”), the step of polymerizing the monomer component (i) contained in the aqueous dispersion in the presence of the polymerization initiator to produce an emulsion containing seed polymerized particles (Hereinafter referred to as “second step”), and a monomer component (ii) containing a polymerizable crosslinkable monomer and a polymerizable water-soluble monomer is added to the emulsion. Thereafter, a step of polymerizing the monomer component (ii) in the presence of a polymerization initiator (hereinafter referred to as “third step”) is sequentially provided. According to this method, in the third step, the polymerization of the monomer component (ii) proceeds in a state where the crosslinkable monomer is absorbed by the seed polymer particles, and the monomer component is formed on the surface of the seed polymer particles. A polymer layer containing the structural unit derived from (ii) is formed. At that time, the seed polymer particles shrink with the polymerization of the crosslinkable monomer, and voids are formed inside.

  In the first step, pigment particles, the monomer component (i), an aqueous medium containing water, and other raw material components as necessary are used.

  The monomer component (i) used in the first step mainly contains a non-crosslinkable hydrophobic monomer, that is, preferably contains 80% by mass or more. As this hydrophobic monomer, “other monomer” that forms another structural unit (c) constituting the polymer phase is usually applied, and an aromatic vinyl compound, (meth) acrylic acid alkyl ester is used. A compound, a (meth) acrylic acid ester compound having a functional group such as an alkoxyl group, a cyano group, a vinyl cyanide compound, a conjugated diene compound, a non-conjugated diene compound, an epoxy group-containing unsaturated compound, or the like can be used. These may be used alone or in combination of two or more.

The monomer component (i) may contain a crosslinkable monomer having a polymerizable property, a water-soluble monomer having a polymerizable property, and the like, if necessary.
Examples of the crosslinkable monomer and the water-soluble monomer include “crosslinkable monomer” and “water-soluble monomer” that form the structural units (a) and (b) constituting the polymer phase. Can be applied respectively.
The content of the crosslinkable monomer is preferably 10% by mass or less, more preferably 5% by mass or less, when the monomer component (i) is 100% by mass.
The content of the water-soluble monomer is preferably 10% by mass or less, more preferably 5% by mass or less, when the monomer component (i) is 100% by mass.
When the monomer component (i) used in the first step has the above structure, seed particles that efficiently form hollow particles can be obtained.

  The amount of the monomer component (i) used is preferably 2 to 30 parts by mass, more preferably 4 to 25 parts by mass, when the dispersion medium is 100 parts by mass. When the amount is used, seed particles having excellent stability during polymerization can be formed.

In the first step, a dispersant, an emulsifier, or the like can be used.
Examples of the dispersant include higher fatty acid salts, polycarboxylic acids, polyvinyl alcohol, methyl cellulose, ethyl cellulose, carboxymethyl cellulose, and polyethylene glycol.
The amount of the dispersant used is preferably 5 to 50 parts by mass, more preferably 8 to 40 parts by mass, and still more preferably 10 to 30 parts by mass with respect to 100 parts by mass of the pigment particles.

As an emulsifier, an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant can be used. These may be used alone or in combination.
Examples of the anionic surfactant include sulfates of higher alcohols, alkylbenzene sulfonates, aliphatic sulfonates, and sulfates of polyethylene glycol alkyl ethers.
Examples of nonionic surfactants include polyethylene glycol alkyl esters, alkyl ethers, and alkylphenyl ethers.
Amphoteric surfactants include compounds having a carboxylate, sulfate, sulfonate, or phosphate ester salt as the anion moiety and an amine salt or quaternary ammonium salt as the cation moiety, such as lauryl betaine, Examples include betaine type compounds such as stearyl betaine; amino acid type compounds such as lauryl-β-alanine, stearyl-β-alanine, lauryl di (aminoethyl) glycine, and octyldi (aminoethyl) glycine.
The amount of the emulsifier used is preferably 0.1 to 5 parts by mass, more preferably 0.2 to 3 parts by mass with respect to 100 parts by mass of the monomer component (i).

The aqueous dispersion may further contain a polymerization initiator, a chain transfer agent, an organic solvent, and the like.
The polymerization initiator is preferably an oil-soluble polymerization initiator, such as cumyl peroxide, tert-butyl peroxide, propionyl peroxide, benzoyl peroxide, chlorobenzoyl peroxide, dichlorobenzoyl peroxide, bromomethylbenzoyl peroxide, Lauroyl oxide, diisopropyl peroxycarbonate, 1-phenyl-2-methylpropyl-1-hydroperoxide, pertriphenylacetic acid-tert-butyl hydroperoxide, tert-butyl performate, tert-butyl peracetate, tert-perbenzoic acid -Peroxides such as butyl, tert-butyl perphenyl acetate, tert-butyl permethoxyacetate, tert-butyl per-N- (3-toluyl) palmitate, di (3,5,5-trimethylhexanoyl) peroxide 2,2′-azobispropane, 2,2 '-Dichloro-2,2'-azobispropane, 2,2'-azobisisobutane, 2,2'-azobisisobutylamine, 2,2'-azobisisobutyronitrile, 2,2'-azobis Methyl 2-methylpropionate, 2,2′-dichloro-2,2′-azobisbutane, 2,2′-azobis-2-methylbutyronitrile, dimethyl 2,2′-azobisisobutyrate, 1,1′- Azobis (sodium 1-methylbutyronitrile-3-sulfonate), 2- (4-methylphenylazo) -2-methylmalonodinitrile, 3,5-dihydroxymethylphenylazo-2-methylmalonodinitrile, 2 -(4-Bromophenylazo) -2-allylmalonodinitrile, 2,2'-azobis-2-methylvaleronitrile, dimethyl 4,4'-azobis-4-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′-azobiscyclohexanenitrile, 2,2′-azobis-2-propylbutyronitrile, 1,1′-azobis-1-chlorophenylethane, 1,1 '-Azobis-1-cyclohexanecarbonitrile, 1,1'-azobis-1-cycloheptanecarbonitrile, 1,1'-azobis-1-phenylethane, 1,1'-azobiscumene, 4-nitrophenylazobenzylcyano Ethyl acetate, phenylazodiphenylmethane, phenylazotriphenylmethane, 4-nitrophenylazotri Phenylmethane, 1,1′-azobis-1,2-diphenylethane, poly (bisphenol A-4,4′-azobis-4-cyanopentanoate), poly (tetraethylene glycol-2,2′-azobisiso Butyrate) and the like.
The amount of the polymerization initiator used is preferably 1 to 30 parts by mass, more preferably 2 to 25 parts by mass with respect to 100 parts by mass of the monomer component (i).

Examples of the chain transfer agent include mercaptan compounds such as tert-dodecyl mercaptan, octyl mercaptan, n-tetradecyl mercaptan, and tert-hexyl mercaptan; halogen compounds such as ethylene bromide. When this chain transfer agent is used, the molecular weight of the seed polymerized particles obtained in the second step can be reduced, and the monomer component (iii) used in the third step can be easily absorbed by the seed polymerized particles. Can do.
When using the said chain transfer agent, the usage-amount is preferably 1-30 mass parts with respect to 100 mass parts of said monomer components (i), More preferably, it is 2-25 mass parts.

  The polymerization initiator and the chain transfer agent may be used as raw materials for preparing the aqueous dispersion, or may be used during the polymerization of the monomer component (i) in the second step.

The organic solvent is preferably a hydrophobic compound, and examples thereof include toluene, xylene, methyl chlorobenzene, methyl ethyl ketone, methyl isobutyl ketone, N-methyl-2-pyrrolidone, and ethylene glycol mono n-butyl ether.
When using the said organic solvent, the usage-amount becomes with respect to 100 mass parts of said pigment particles, Preferably it is 1-50 mass parts, More preferably, it is 2-40 mass parts.

The method for preparing the aqueous dispersion is not particularly limited, but a ball mill, sand mill, attritor, roll mill, agitator, Henschel mixer, colloid mill, ultrasonic homogenizer, pearl mill, wet jet mill, paint shaker, high pressure homogenizer (microfluidizer) It is preferable to use a mixing device such as a nanomizer. Among these apparatuses, a high-pressure homogenizer is preferable because a strong shearing force is applied to reduce the aggregation unit of pigment particles and a dispersion having excellent dispersibility can be prepared. When this high-pressure homogenizer is used, the preferable shearing force is 10 MPa or more, more preferably 30 MPa or more.
In preparation of the aqueous dispersion, the aqueous medium and all other raw material components may be mixed together, or the raw material components other than the aqueous medium may be divided to prepare a plurality of aqueous dispersions. Alternatively, a part of the aqueous medium and a part of other raw material components may be mixed to prepare a plurality of aqueous dispersions, and these aqueous dispersions may be mixed together.

  In the aqueous dispersion obtained as described above, the pigment particles and the monomer component (i) are preferably in contact with each other and dispersed as fine droplets. Further, when an oil-soluble polymerization initiator and a hydrophobic organic solvent are used as raw material components, these are also in contact with the pigment particles and the monomer component (i) and become fine droplets. Are preferably dispersed.

The second step is a step of producing an emulsion containing seed polymer particles by polymerizing the monomer component (i) contained in the aqueous dispersion in the presence of a polymerization initiator.
In the second step, the monomer component (i) is usually polymerized while stirring the aqueous dispersion. As a result, a composite particle in which pigment particles are dispersed in a polymer formed by the monomer component (i) in a dispersion medium containing water, that is, an emulsion containing seed polymer particles is obtained. The polymerization temperature is selected depending on the kind of the polymerization initiator, but is usually 20 ° C to 90 ° C, preferably 30 ° C to 85 ° C. The polymerization time is usually 1 to 12 hours, preferably 3 to 10 hours.

The seed polymer particles are granular bodies having a shape such as a sphere or an elliptic sphere, and the average particle diameter is preferably 10 nm to 99 μm, more preferably 30 nm to 50 μm, and still more preferably 50 nm to 10 μm. If the average particle diameter is too large, the hollow (space part) in the finally obtained colorant for toner may not be stably formed.
Moreover, the weight average molecular weight of the polymer contained in the seed polymer particles is preferably 100,000 or less, more preferably 50,000 or less, and still more preferably 10,000 or less. If this weight average molecular weight is too large, the hollow (space part) in the finally obtained colorant for toner may not be stably formed.

  Next, in the third step, a monomer component (ii) containing a polymerizable crosslinkable monomer and a polymerizable water-soluble monomer is added to the emulsion obtained in the second step. The step of adding and then polymerizing the monomer component (ii) in the presence of a polymerization initiator.

The monomer component (ii) used in the third step contains a polymerizable crosslinkable monomer and a polymerizable water-soluble monomer, and if necessary, these single monomers It may also contain a monomer copolymerizable with the body (usually a non-crosslinkable hydrophobic monomer). As each of the above-mentioned monomers, the respective compounds forming the structural units (a), (b) and (c) constituting the polymer phase contained in the toner colorant according to the present invention can be applied. .
By using the crosslinkable monomer, the seed polymer particles contained in the emulsion can be swollen, and the shape is shrunk as the polymerization proceeds in the third step, so that voids are easily formed inside. Can do.
The content of the crosslinkable monomer is preferably 1 to 60% by mass, more preferably 2 to 50% by mass, and still more preferably 5 to 5%, when the monomer component (ii) is 100% by mass. 40% by mass. When a crosslinkable monomer is used in the above range, hollow particles can be efficiently formed while proceeding with stable polymerization.
The content of the water-soluble monomer is preferably 0.5 to 15% by mass, more preferably 1 to 10% by mass, when the monomer component (ii) is 100% by mass. . When a water-soluble monomer is used within the above range, hollow particles can be efficiently formed while advancing stable polymerization without abnormally increasing the viscosity of the reaction system.

  The amount of the monomer component (ii) used is preferably 100 to 10,000 parts by mass, more preferably 200 to 8,000 parts by mass, when the seed polymer particles contained in the emulsion are 100 parts by mass. More preferably, it is 300 to 5,000 parts by mass. When the monomer component (ii) is used within the above range, hollow particles can be efficiently formed while a stable polymerization is proceeding.

In the third step, a polymerization initiator is usually used, and this polymerization initiator may be either an oil-soluble polymerization initiator or a water-soluble polymerization initiator. Although these may be used in combination, it is preferable to use a water-soluble polymerization initiator because hollow particles having a space portion (hollow) with a high porosity can be produced.
Examples of water-soluble polymerization initiators include persulfates such as ammonium persulfate and potassium persulfate; 2,2′-azobis (2-amidinopropane) hydrochloride, 2,2′-azobis (2-amidinopropane) nitrate, and bissuccin An acid peroxide, a bisglutaric acid peroxide, etc. are mentioned. Also, organic peroxides such as benzoyl peroxide, methyl ethyl ketone peroxide, dicumyl peroxide, tert-butyl perbenzoate and cumene hydroperoxide; persulfates such as ammonium persulfate and potassium persulfate; and hydrogen peroxide Oxidizing agents and bisulfites such as sodium bisulfite; divalent iron salts such as ferrous sulfate and ferrous chloride; amine compounds such as N, N-dimethylaniline and phenylmorpholine; cobalt naphthenate and naphthene A redox polymerization initiator which is a combination of reducing agents composed of metal naphthenate such as manganese acid and copper naphthenate can also be used.
The amount of the polymerization initiator used is preferably 0.01 to 10 parts by mass, more preferably 0.07 to 5 parts by mass, and still more preferably 0.000 to 100 parts by mass of the monomer component (ii). 1 to 4 parts by mass.

  The reaction system in the third step may contain a chain transfer agent (molecular weight regulator).

  In the third step, the monomer component (ii) is usually polymerized while stirring the reaction system containing the polymerization initiator. As polymerization proceeds, the seed polymer particles swollen by the monomer component (ii) shrink and form a space (hollow) therein, and at the same time, the monomer component (ii) on the surface of the seed polymer particles. Thus, an emulsion containing the colorant for toner of the present invention having an outer wall containing the polymer and pigment particles and at least one space inside thereof can be obtained. The polymerization temperature is selected depending on the kind of the polymerization initiator, but is usually 20 ° C to 90 ° C, preferably 30 ° C to 85 ° C. The polymerization time is usually 1 to 12 hours, preferably 3 to 10 hours.

  In addition, another preferable method for producing the colorant for toner of the present invention is a step of preparing an aqueous dispersion containing pigment particles and a monomer component (iii) containing a polymerizable crosslinkable monomer ( Hereinafter referred to as “preparation step”), and in this aqueous dispersion, a step of polymerizing the monomer component (iii) in the presence of a water-soluble polymerization initiator (hereinafter referred to as “polymerization step”), It is a method to prepare. According to this method, it is possible to obtain an emulsion in which the colorant for toner of the present invention is dispersed and contained only once in the polymerization step.

  In the preparation step, pigment particles, a monomer component (iii), an aqueous medium containing water, and other raw material components as necessary are used.

  The content of the crosslinkable monomer contained in the monomer component (iii) is preferably 1 to 60% by mass, more preferably 2 to 50% by mass, and further preferably 5 to 40% by mass. . When a crosslinkable monomer is used in the above range, hollow particles can be efficiently formed while proceeding with stable polymerization.

  Examples of the other monomer contained in the monomer component (iii) include the hydrophobic monomer and the water-soluble monomer described above. When a water-soluble monomer is used, the amount used is preferably 15% by mass or less, more preferably 10% by mass or less, based on the monomer component (iii). Therefore, the balance is a hydrophobic monomer.

In the preparation step, a dispersant, an emulsifier, a water-soluble polymerization initiator, a chain transfer agent, an organic solvent, and the like can be used. Use of an organic solvent facilitates the production of hollow particles having a space portion (hollow) with a high porosity.
The amount of the dispersant used is preferably 5 to 50 parts by mass, more preferably 8 to 40 parts by mass, and still more preferably 10 to 30 parts by mass with respect to 100 parts by mass of the pigment particles.
Moreover, the usage-amount of the said emulsifier becomes like this. Preferably it is 0.1-5 mass parts with respect to 100 mass parts of said monomer components (iii), More preferably, it is 0.2-3 mass parts.

  The polymerization initiator and the chain transfer agent may be used as raw materials for preparing the aqueous dispersion, or may be used during the polymerization of the monomer component (iii) in the polymerization step.

  The method for preparing the aqueous dispersion can be the same as described above.

Next, the polymerization step is a step of polymerizing the monomer component (iii) in the presence of a water-soluble polymerization initiator in the aqueous dispersion obtained by the above preparation step.
The amount of the water-soluble polymerization initiator used is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, and still more preferably 0 with respect to 100 parts by mass of the monomer component (iii). .1 to 4 parts by mass.

  The reaction system in the polymerization step may contain a chain transfer agent (molecular weight regulator).

  In the polymerization step, the monomer component (iii) is polymerized while stirring the reaction system to obtain an emulsion containing the colorant for toner of the present invention. The polymerization temperature is selected depending on the kind of the polymerization initiator, but is usually 20 ° C to 90 ° C, preferably 30 ° C to 85 ° C. The polymerization time is usually 1 to 12 hours, preferably 3 to 10 hours.

  The colorant for toner of the present invention can be suitably used as a colorant for polymerized toner. The polymerized toner refers to a toner obtained from a method of directly producing toner particles by a polymerization process. For example, a polymer obtained by dispersing a composition containing a pigment (colorant for polymerized toner), a polymerizable monomer, a polymerization initiator, etc. in an aqueous system and performing polymerization, and the pigment dispersed in the polymer. And a toner containing

  The polymerized toner is polymer particles obtained by polymerizing a polymerizable monomer. When the colorant for toner of the present invention is used, the composite particles of the present invention are dispersed in the polymerized toner particles. The polymerized toner particles exhibit the color developability by including the composite particles in the present invention.

  The blending amount when the colorant for toner of the present invention is used for the polymerized toner is preferably 0.1 to 60 parts by mass, more preferably 0 to 100 parts by mass of all monomers forming the polymerized toner. It is 5-50 mass parts, More preferably, it is 1-45 mass parts. When the content of the toner colorant is within the above range, the polymerized toner exhibits color developability.

  A method for producing a polymerized toner using the toner colorant of the present invention is not particularly limited, and a conventional polymerized toner production method can be used. For example, a method in which an additive such as a monomer, a colorant, a polymerization initiator, a crosslinking agent, and other charge control agents is dispersed in an aqueous medium using a suitable stirrer, and a polymerization reaction is performed. .

  The monomer preferably contains a vinyl monomer. Examples of vinyl monomers include aromatic vinyl compounds such as styrene, vinyl toluene, and α-methylstyrene; unsaturated acids such as (meth) acrylic acid; methyl (meth) acrylate, ethyl (meth) acrylate, ( (Meth) acrylic acid ester compounds such as propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate and dimethylaminoethyl (meth) acrylate; vinyl cyanide such as acrylonitrile and methacrylonitrile Compound; unsaturated amide compound such as acrylamide and methacrylamide; ethylenically unsaturated monoolefin such as ethylene, propylene and butylene; vinyl halide compound such as vinyl chloride, vinylidene chloride and vinyl fluoride; vinyl acetate, vinyl propionate, etc. Vinyl ester compounds; vinyl methyl ester Ether, vinyl ether compounds such as vinyl ethyl ether, vinyl methyl ketone, vinyl ketone compounds such as methyl isopropenyl ketone; 2-vinylpyridine, 4-vinylpyridine, nitrogen-containing vinyl compounds such as N- vinyl pyrrolidone. These vinyl monomers can be used alone or in combination of two or more.

  The monomer may further contain a crosslinkable monomer. When a monomer containing this crosslinkable monomer is used, the preservative compound can be improved. Examples of the crosslinkable monomer include aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene, and derivatives thereof; diethylenically unsaturated carboxylic acid esters such as ethylene glycol dimethacrylate and diethylene glycol dimethacrylate; N, N-divinyl. And divinyl compounds such as aniline and divinyl ether; compounds having three or more vinyl groups; and the like. These crosslinkable monomers can be used alone or in combination of two or more. The amount of the crosslinkable monomer used is preferably 0.1 to 5 parts by mass, more preferably 0.3 to 2 parts by mass with respect to 100 parts by mass of the vinyl monomer.

  Examples of the polymerization initiator include persulfates such as potassium persulfate and ammonium persulfate; 4,4-azobis (4-cyanovaleric acid), 2,2-azobis (2-amidinopropane) dihydrochloride. 2,2-azobis-2-methyl-N-1,1-bis (hydroxymethyl) -2-hydroxyethylpropioamide, 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2 Azo compounds such as' -azobisisobutyronitrile, 1,1'-azobis (1-cyclohexanecarbonitrile); methyl ethyl peroxide, di-tert-butyl peroxide, acetyl peroxide, dicumyl peroxide, lauroyl peroxide, benzoyl peroxide , Tert-butyl peroxy-2-ethylhexanoate, di-isopropyl per Carboxymethyl dicarbonate, such peroxides di -tert- butyl peroxy isophthalate, and the like. Moreover, the redox initiator which combined these polymerization initiators and reducing agents can be mentioned. Of these, organic peroxides are preferred. The usage-amount of a polymerization initiator is 0.001-3 mass% normally on the basis of an aqueous medium. If it is less than 0.001% by mass, the polymerization rate is slow, and if it exceeds 3% by mass, particles having a particle diameter of less than 1 μm may be generated.

  As the charge control agent, various positively charged or negatively charged charge control agents can be used. Specific examples of the charge control agent include nigrosine N01 (manufactured by Orient Chemical), nigrosine EX (manufactured by Orient Chemical), spiro black TRH (manufactured by Hodogaya Chemical), T-77 (manufactured by Hodogaya Chemical), and Bontron S-. 34 (manufactured by Orient Chemical Co., Ltd.), Bontron E-84 (manufactured by Orient Chemical Co., Ltd.) and the like. The usage-amount of a charge control agent is 0.01-10 mass parts normally with respect to 100 mass parts of whole quantity of a monomer, Preferably it is 0.1-5 mass parts.

  Furthermore, if necessary, various additives such as a molecular weight modifier and a release agent can be mixed with the monomer composition and added to the dispersion medium.

  The colorant for toner of the present invention can be used in a polymerized toner in the same manner as ordinary organic pigments and inorganic pigments. That is, in the production of the polymerized toner, the toner colorant of the present invention, the monomer composition, and a crosslinkable monomer, a polymerization initiator, a charge control agent and other additives selected as necessary are mixed, A liquid mixture is prepared by uniformly dispersing with a ball mill or the like, and then the liquid mixture is put into an aqueous dispersion medium containing a dispersing agent and dispersed using a mixing apparatus having a high shearing force to form fine droplets. After the granulation, the polymerized toner is usually obtained by suspension polymerization at a temperature of 30 to 200 ° C.

In the production of a polymerized toner, when a colorant composed of an organic pigment and an inorganic pigment is used as it is as a colorant for toner, the charge characteristics differ depending on the type of the pigment, and therefore an appropriate charge control agent according to the charge characteristics of the pigment. Is necessary.
However, since the colorant for toner of the present invention is a colorant composed of composite particles in which pigment particles are dispersed in a polymer phase, it has a constant chargeability regardless of the type of color. It becomes easy to control the chargeability.
In addition, since the colorant for toner of the present invention is a composite particle in which pigment particles are dispersed in a polymer phase, it has excellent affinity with a polymerizable monomer used for forming a polymerized toner, and produces a polymerized toner. Excellent dispersibility in time. The colorant for toner of the present invention can be suitably used as a colorant for polymerized toner.

[2] Toner The toner of the present invention is a toner (hereinafter referred to as “toner particles”) containing a binder resin and the toner colorant (composite particles) of the present invention.
The toner particles of the present invention are preferably aggregated particles formed by emulsion aggregation or the like from a toner raw material containing a binder resin and a toner colorant. More preferably, the plurality of toner colorants are bound by a binding portion made of a binding resin.

  The binder resin is a resin conventionally known as a binder resin for toner. For example, polystyrene, polychlorostyrene, poly α-methylstyrene, styrene / chlorostyrene copolymer, styrene / propylene copolymer, styrene / butadiene copolymer, styrene / vinyl chloride copolymer, styrene / vinyl acetate copolymer Styrene such as styrene / (meth) acrylic acid copolymer, styrene / (meth) acrylic acid ester copolymer, styrene / methyl α-chloroacrylate copolymer, styrene / acrylonitrile / acrylic acid ester copolymer Resins Resin vinyl chloride resin, rosin-modified maleic acid resin, phenol resin, epoxy resin, saturated polyester resin, unsaturated polyester resin, polyethylene resin such as polyethylene and ethylene / ethyl acrylate copolymer, polypropylene resin, ionomer resin, polyurethane resin, Silicone resin, ketone resin, xylene resin, polyvinyl butyral resin, polycarbonate resin and the like can be mentioned. These resins can be used alone or in combination of two or more.

  The weight average molecular weight (Mw) of the resin is preferably 3,000 to 150,000, more preferably 4,000 to 100,000, and still more preferably 5,000 to 50,000. When the amount is within the above range, the powder characteristics of the toner at normal temperature can be kept good.

  The glass transition point of the binder resin is preferably 10 ° C to 100 ° C, more preferably 20 ° C to 90 ° C, and further preferably 25 ° C to 85 ° C. When it is within the above range, the toner particles are excellent in storability and printing fixability.

In the toner particles of the present invention, the colorant for toner of the present invention may be used singly or in combination of two or more of the same colorants. Further, two or more kinds of different colorants may be mixed and used.
Further, the content of the toner colorant is preferably 5 to 200 parts by mass, more preferably 8 to 150 parts by mass, and still more preferably 10 to 100 parts by mass based on 100 parts by mass of the binder resin. Part by mass. In the case of the above range, a good image can be formed by the toner particles of the present invention.

  Further, the toner particles of the present invention may contain a release agent for the purpose of improving fixability and image storage stability. Examples of the release agent include low molecular weight polyolefins such as polyethylene, polypropylene, and polybutene: silicones having a softening point by heating: fatty acid amides such as oleic acid amide, erucic acid amide, ricinoleic acid amide, and stearic acid amide Kinds: Plant waxes such as carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil, etc .: Animal waxes such as beeswax: montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, microcrystalline wax And minerals such as Fischer-Tropsch wax or petroleum wax. Moreover, those modified | denatured products can also be used. These can be used alone or in combination of two or more.

  In addition, a charge control agent can be used for the toner particles of the present invention in order to improve and stabilize the chargeability. Examples of the charge control agent include quaternary ammonium salt compounds, nigrosine compounds, salicylic acid metal salts, metal-containing azo compounds, dyes composed of complexes of aluminum, iron, chromium, and triphenylmethane pigments. These can be used alone or in combination of two or more.

  The toner particles of the present invention preferably have a volume average particle diameter of 1 to 10 μm, more preferably 2 to 9 μm, and further preferably 2.5 to 8 μm. When the volume average particle diameter of the toner is within the above range, the chargeability is excellent and the resolution of the image is improved.

The charge amount of the toner particles of the present invention is preferably 10 to 50 μC / g in absolute value, more preferably 20 to 40 μC / g, and still more preferably 15 to 35 μC / g. If it is within the above range, background stains (fogging) are less likely to occur, and the image density is also difficult to decrease.
The ratio of the charge amount of the toner particles of the present invention in summer (high temperature and high humidity) to the charge amount in winter (low temperature and low humidity) is preferably 0.4 to 1.7, and more preferably 0.5 to 1. 0.5, and more preferably 0.7 to 1.3. When the charge amount of the toner particles is within the above range, the charging property is less dependent on the environment and the charging stability is excellent.

The BET specific surface area of the toner particles of the present invention is preferably 1.1 to 3.5 m ² / g, more preferably 1.1 to 3.0 m ² / g, and still more preferably 1.1. -2.5 m < ² > / g. When the BET specific surface area is within the above range, the surface frictional property is improved and the charge rising property and chargeability are excellent.

The method for producing the toner particles is not particularly limited, and is produced by a conventional method. Specific examples of the production method include a melt suspension method, an emulsion aggregation method, and a dissolution suspension method.
For example, in the emulsion aggregation method, a process of forming aggregated particles in a dispersion in which binder resin fine particles serving as a binder resin are dispersed to prepare an aggregated particle dispersion (aggregation process), and heating the aggregated particle dispersion Thus, the production method includes a step of fusing the aggregated particles (fusion step).

In the aggregating step, first, a binder resin particle dispersion, a colorant dispersion, a release agent particle dispersion, and the like are prepared. The binder resin particle dispersion is heated by a known phase inversion emulsification or abnormal melting point and emulsified by mechanical shearing force. Moreover, an ionic surfactant may be added.
The colorant particle dispersion is prepared by dispersing the colorant for toner of the present invention in an aqueous solvent by mechanical shearing force or the like.
The release agent particle dispersion is prepared by granulating the release agent in an aqueous solvent with a homogenizer or pressure discharge type disperser that can be heated to a melting point or higher or subjected to strong shearing. In addition, a polymer electrolyte such as an ionic surfactant, a polymer acid, or a polymer base can be added to the release agent particle dispersion as necessary.

  In the aggregation step, the binder resin particles, the colorant particles, and the release agent particle dispersion are mixed and stirred to agglomerate the binder resin particles, the colorant particles, and the release agent particles. To form aggregated particles.

In the fusion step, the aggregate particles are fused and united by heating at a temperature equal to or higher than the glass transition temperature (Tg) of the binder resin under the same stirring as in the aggregation step.
There is no problem if the heating temperature is equal to or higher than the Tg of the binder resin. Further, the heating time may be performed so that the coalescence is sufficiently performed, and may be performed for about 0.2 to 10 hours. Thereafter, the temperature is lowered to Tg of the resin or less to solidify the particles.
In addition, the particle shape and surface properties change depending on the temperature drop rate. For example, when the temperature is lowered at a high speed, the spheroidization and the surface are easily smoothed. On the other hand, when the temperature is slowly lowered, the particle shape becomes irregular and the surface of the particles is likely to be uneven. Therefore, it is preferable to lower the temperature to at most Tg of the resin at a rate of at least 0.5 ° C./min, preferably at a rate of 1.0 ° C./min.

  After the fusion process, a desired toner is obtained through an optional solid-liquid separation process, washing process, and drying process. The separation method in the solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration and the like are preferably used from the viewpoint of productivity. Moreover, it is preferable that the washing | cleaning method of a washing | cleaning process performs substitution washing | cleaning by ion-exchange water fully from a charging point. Also, the drying method in the drying step is not particularly limited, but freeze drying, flash jet drying, fluidized drying, vibration fluidized drying and the like are preferably used from the viewpoint of productivity.

In addition, toner particles having a binder resin and a colorant obtained as described above may contain known external additives (for toner, such as inorganic fine particles and organic fine particles) as flow aids, cleaning aids, and abrasives. External additives) can be externally mixed.
The inorganic fine particles are generally used for the purpose of improving the fluidity of toner particles. Examples of the inorganic fine particles include silica, alumina, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, cerium chloride, bengara, Examples of the particles include chromium oxide, cerium oxide, antimony trioxide, magnesium oxide, zirconium oxide, silicon carbide, and silicon nitride. Among these, silica particles are preferable, and hydrophobized silica particles are more preferable. These can be used alone or in combination of two or more.

  Moreover, the average particle diameter of the inorganic fine particles is preferably 1 to 1000 nm, more preferably 10 to 500 nm, and still more preferably 30 to 200 nm. The addition amount (external addition) is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and further preferably 1 to 5 parts by mass with respect to 100 parts by mass of the toner. Part.

  The organic fine particles are generally used for the purpose of improving cleaning properties and transferability. Examples of the organic fine particles include particles such as polystyrene, polymethyl methacrylate, and polyvinylidene fluoride. These can be used alone or in combination of two or more.

[3] Developer The developer of the present invention includes the toner particles of the present invention and a carrier. Since the toner particles of the present invention have stable charging characteristics as described above, they are excellent in adsorption to a carrier. Furthermore, this developer has stable charging characteristics and stable quality after printing.

  The carrier that can be used in the present invention is not particularly limited. Usually, magnetic particles such as ferrite, iron powder, iron oxide powder, and nickel; magnetic particles are used as a core material and the surface thereof is a styrene resin or vinyl resin. Resin-coated carrier formed by coating a resin, ethylene-based resin, rosin-based resin, polyester-based resin, melamine-based resin or the like, or a wax such as stearic acid, and forming a resin coating layer; magnetic particles in the binder resin And a magnetic material-dispersed carrier in which is dispersed. Among them, the resin-coated carrier is particularly preferable because the chargeability of the toner and the resistance of the entire carrier can be controlled by the configuration of the resin coating layer.

  The average film thickness of the resin coating layer is preferably 0.1 to 10 μm, more preferably 0.2 to 5 μm. When the average film thickness of the resin coating layer is within the above range, it is easy to control the chargeability of the toner and the resistance of the entire carrier.

  The average particle diameter of the carrier is preferably 1 to 200 μm, more preferably 10 to 100 μm, and still more preferably 20 to 80 μm. When the average particle diameter of the carrier is within the above range, adhesion of the toner particles to the carrier and adhesion of the toner particles to the photoreceptor and the like are good.

The content ratio of the toner particles and the carrier in the developer of the present invention is usually 1 to 50 parts by mass, preferably 2 to 20 parts by mass, and more preferably 5 to 100 parts by mass of the carrier. -15 parts by mass. When the content ratio of the toner particles and the carrier is within the above range, the transfer of the toner particles to the photoconductor is favorably performed.
Moreover, the manufacturing method of a developing agent is not specifically limited, For example, the method etc. which mix with a V blender etc. are mentioned.
The developer of the present invention is a developer containing the toner particles and carrier of the present invention, and may or may not contain other components.

The charge fluctuation rate obtained by the following measuring method in the developer of the present invention is preferably 0 to 20%, more preferably 18% or less, and further preferably 15% or less. When the charging fluctuation rate is within the above range, a developer having excellent charging characteristics can be obtained.
The charge amount fluctuation rate is obtained by the following formula (1). In this case, the charge amount of the developer is measured in an environment having a temperature of 25 ° C. and a relative humidity of 55%, this charge amount is set as [charge amount 1], and after measuring [charge amount 1], the developer is heated to 30 ° C. After curing for 2 days in a constant temperature and humidity chamber with a relative humidity of 90%, the charge amount of the developer is measured, and this charge amount is defined as [charge amount 2].
Charge amount fluctuation rate (%) = ([charge amount 1] − [charge amount 2]) / [charge amount 1] × 100 (1)

Moreover, the optical density (OD value) obtained by the following measuring method in the developer of the present invention is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and still more preferably. 1.0 to 2.5. When the optical density (OD value) is within the above range, a developer having excellent color developability can be obtained.
The optical density (OD value) was measured by measuring the optical density (OD value) of the solid portion of the image using a Macbeth densitometer (model number “RD-19I”, manufactured by Sakata Inx Corporation). The image conditions for measuring the optical density are as follows. An image is output using a modified printer “DocuPrint C3250” manufactured by Fuji Xerox Co., Ltd. filled with developer, and coated paper “Ncolor157” (fine coating) manufactured by Fuji Xerox Co., Ltd. is used as the recording medium. Working mat), a feed rate of 160 mm / second, and a fixing temperature of 180 ° C.

Image formation with the developer of the present invention can be performed using a known method. For example, an electrostatic image is formed and developed by a conventional electrophotographic copying machine, and the obtained toner image is electrostatically transferred onto a transfer paper and fixed by a heating roller fixing device in which the temperature of the heating roller is set to a constant temperature. To form a copy image.
The image forming method is particularly preferably used for high-speed fixing in which the contact time between the toner particles on the transfer paper and the heating roller is within 1 second, particularly within 0.5 seconds.

  The developer of the present invention can be used in a known electrostatic image developing system (electrophotographic system) image forming method. This image forming method includes, for example, an electrostatic latent image forming step, a toner image forming step, a transfer step, and a cleaning step.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. In the synthesis examples, examples and comparative examples, “parts” and “%” are based on mass unless otherwise specified. Various measurements in the synthesis examples, examples, and comparative examples are performed by the following methods.

[Average particle size]
The longest value among the particle diameters observed by a transmission electron microscope “H-7650” (manufactured by Hitachi High-Technologies Corporation) is measured as the particle diameter, and the above-mentioned particle diameters of 100 particles existing in the observation field are measured. The average value is calculated.
[Ratio of total volume occupied by voids (void ratio)]
Ten particles observed by a transmission electron microscope “H-7650” (manufactured by Hitachi High-Technologies Corporation) are arbitrarily selected, and for these particles, “the ratio of the total volume occupied by the voids” according to the following equation (1): Is calculated.
Equation (1): [{(outer diameter ^{/ 2} of the particle) 4 [pi] 3/3} (total void volume) /] × 100
(Here, for example, when there is one void inside the particle, it can be calculated by {(inner diameter of the void) ³ / (outer diameter of the particle) ³ } × 100).
[Volume average particle diameter]
A particle size distribution measuring device “Coulter Counter Multisizer II” (manufactured by Beckman-Coulter) was used, and ISOTPN-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 sodium alkylbenzenesulfonate as a dispersant. This was added to 100 ml of the electrolytic solution.

[1] Production of colorant for toner (Example 1-1)
(1) Synthesis of Second Emulsion Monomer component (i) comprising 30 parts of styrene and 10 parts of butyl acrylate, 3 parts of t-dodecyl mercaptan, and carbon black (“# 2600” (trade name), Mitsubishi Chemical Co., Ltd.) as a pigment 50 parts of the mixture and dispersed with a stirrer, 100 parts of a polyvinyl alcohol 10% aqueous solution (“GOHSENOL GL03”, manufactured by Nippon Gosei Kagaku), 10 parts of a 10% aqueous solution of sodium dodecylbenzenesulfonate and distilled water (table) 1 was added, and 280 parts were added and dispersed using a homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) as a stirrer to obtain a first emulsion. Thereafter, the obtained first emulsion was emulsified and dispersed at a pressure of 70 MPa using a high-pressure homogenizer (“Microfluidizer M110Y”, manufactured by Mizuho Kogyo Co., Ltd.) to obtain an emulsified dispersion. The emulsified dispersion was put into a separable flask and purged with nitrogen while stirring. Then, 5 parts of AIBN (azobisisobutyronitrile) was added as an oil-soluble initiator, and polymerization was performed at 75 ° C. for 4 hours to obtain seed particles. A second emulsion (1-1) containing was obtained. The solid content concentration of the obtained second emulsion (1-1) was adjusted to 20% (the concentration of seed particles was 20%).
The seed particles in the obtained second emulsion (1-1) had a polymerization conversion rate of 98.5%, and the seed particles were observed with a transmission electron microscope “H-7650” (manufactured by Hitachi High-Technologies Corporation). As a result, the average particle size was 160 nm. The obtained seed particles were so-called solid particles in which no voids were formed.
Table 1 shows the blending amounts of the monomer component, pigment, polymerization chain agent, and the like used for the synthesis of the second emulsion, the polymerization conversion rate of the seed particles in the obtained second emulsion, and the average particle size.

(2) Production of aqueous dispersion of toner colorant As shown in Table 2, 200 parts of second emulsion (1-1) containing seed particles, 42 parts of methyl methacrylate, 30 parts of divinylbenzene, butyl acrylate 6 And a monomer component (ii) comprising 2 parts of acrylic acid and 400 parts of distilled water (referred to as “water” in Table 2) were mixed and dispersed with a stirrer to obtain a dispersion. Thereafter, the mixture was emulsified and dispersed at a pressure of 70 MPa using a high-pressure homogenizer (“Microfluidizer M110Y”, manufactured by Mizuho Kogyo Co., Ltd.) to obtain an emulsified dispersion. This emulsified dispersion was put into a separable flask and purged with nitrogen while stirring. Then, 20 parts of a 3% aqueous solution of potassium persulfate was added as a water-soluble initiator and polymerized at 75 ° C. for 4 hours to disperse the composite particles. A colorant aqueous dispersion (1-1) for toner was obtained.
When the composite particles in the obtained dispersion were observed with a transmission electron microscope, the composite particles were confirmed to be composite particles having an average particle diameter of 235 nm and an inner diameter of 130 nm. Further, in the composite particles, the ratio of the total volume occupied by the voids is also shown in Table 2.

(Example 1-2)
(1) Synthesis of Second Emulsion As shown in Table 1, C.I. I. Pigment Blue 15: 3 (“Blue 4 GNP” (trade name), manufactured by Ciba Specialty Chemicals, phthalocyanine pigment) was used in the same manner as in Example 1-1 to obtain a second emulsion containing seed particles ( 1-2) was obtained. Table 1 shows the polymerization conversion rate and average particle size of the seed particles in the obtained second emulsion (1-2).

(2) Production of aqueous dispersion of colorant for toner As shown in Table 2, the same procedure as in Example 1-1 was performed except that the second emulsion (1-2) containing the obtained seed particles was used. A toner colorant aqueous dispersion (1-2) in which composite particles were dispersed was obtained. The average particle diameter of the toner colorant in the obtained dispersion and the ratio of the total volume occupied by the voids are also shown in Table 2.

(Example 1-3)
(1) Synthesis of Second Emulsion As shown in Table 1, C.I. I. Second emulsion containing seed particles in the same manner as in Example 1-1, except that CI Pigment Yellow 93 (“Chromofine Yellow 5930” (trade name), manufactured by Dainichi Seika Co., Ltd., disazo condensation pigment) was used. (1-3) was obtained. Table 1 shows the polymerization conversion rate and average particle diameter of the seed particles in the obtained second emulsion (1-3).

(2) Production of aqueous dispersion of colorant for toner As shown in Table 2, the same procedure as in Example 1-1 was performed except that the second emulsion (1-3) containing the obtained seed particles was used. Thus, a colorant aqueous dispersion (1-3) for toner in which composite particles were dispersed was obtained. The average particle diameter of the toner colorant in the obtained dispersion and the ratio of the total volume occupied by the voids are also shown in Table 2.

(Example 1-4)
(1) Synthesis of Second Emulsion As shown in Table 1, C.I. I. A second emulsion containing seed particles (1-4) in the same manner as in Example 1-1, except that CI Pigment Red 178 ("Paliogen Red K4180" (trade name), manufactured by BASF, perylene pigment) was used. ) Table 1 shows the polymerization conversion rate and average particle diameter of the seed particles in the obtained second emulsion (1-4).

(2) Production of aqueous dispersion of colorant for toner As shown in Table 2, composite particles were obtained in the same manner as in Example 1-1 except that the second emulsion (1-4) containing seed particles was used. A colorant aqueous dispersion (1-4) in which toner is dispersed was obtained. The average particle diameter of the toner colorant in the obtained dispersion and the ratio of the total volume occupied by the voids are also shown in Table 2.

[2] Production and evaluation of toner and developer (Example 2-1)
In a pressure-resistant reaction vessel equipped with a stirrer and a temperature controller, 175 parts of the colorant aqueous dispersion for toner obtained in Example 1-1 (corresponding to 25 parts of polymer / 5 parts of pigment) and the binder resin emulsion shown below Add 200 parts of wax dispersion (“P725 wax” (trade name), manufactured by Baker Petrolite, polyethylene), heat to 60 ° C. with stirring, and hold at that temperature for 2 hours to agglomerate Particles were generated. Thereafter, the aggregated particles were aged and fixed by heat treatment at 95 ° C. for 5 hours. After cooling, the dispersion was filtered, washed and dried to obtain a toner. The obtained toner was measured with a particle size distribution analyzer “Coulter Counter Multisizer II” (manufactured by Beckman Coulter, Inc.). The volume average particle size (D50) was 6.3 μm. Table 3 shows the blending components and the blending amount of each component.
<Binder resin emulsion>
In a pressure-resistant reaction vessel equipped with a stirrer and a temperature controller, 74 parts of styrene, 23 parts of butyl acrylate, 3 parts of acrylic acid, 2 parts of t-dodecyl mercaptan, 10 parts of 10% aqueous solution of sodium dodecylbenzenesulfonate and distilled water 150 parts were charged and the inside of the polymerization system was replaced with nitrogen. Thereafter, 20 parts of a 3% aqueous solution of potassium persulfate is added as an initiator, and polymerization is performed at 75 ° C. for 4 hours to produce an emulsion containing a polymer having a glass transition temperature (Tg) of 60 ° C. This is used as an emulsion of a binder resin. Using.

One part of hydrophobic silica (Cabot Co., TS720) was added to 50 parts of the toner obtained as described above, and mixed with a sample mill to obtain an externally added toner.
Then, a developer was produced using the externally added toner. That is, a ferrite carrier having a volume average particle diameter (D50) of 50 μm coated with 1.5% by mass of polymethyl methacrylate (manufactured by Soken Chemical Co., Ltd .: Mw = 76000) at a blending ratio shown in Table 3, an externally added toner, Was stirred and mixed with a V blender for 10 minutes to obtain a developer. Evaluation of this developer will be described later (see Table 3).

(Examples 2-2 to 2-4)
As shown in Table 3, a toner and an externally added toner were obtained in the same manner as in Example 2-1, except that the toner colorant aqueous dispersion was changed. Further, a developer was produced from the obtained externally added toner in the same manner as in Example 2-1. Table 3 shows the volume average particle diameter of the obtained toner.

(Comparative Example 2-1)
In a pressure-resistant reaction vessel equipped with a stirrer and a temperature controller, 36 parts of an aqueous pigment pigment dispersion (P) obtained by the following method (corresponding to 1 part of polymer / 5 parts of pigment), 264 parts of the binder resin emulsion, Then, 30 parts of the above wax dispersion was added, heated to 60 ° C. with stirring, and maintained at that temperature for 2 hours to produce aggregated particles. Thereafter, the aggregated particles were aged and fixed by heat treatment at 95 ° C. for 5 hours. After cooling, the dispersion was filtered, washed and dried to obtain a toner. The obtained toner had a volume average particle size of 6.4 μm.
To 50 parts of the obtained toner, 1 part of hydrophobic silica (Cabot, TS720) was added and mixed with a sample mill to obtain an externally added toner.
Then, a developer was produced using the externally added toner. That is, a ferrite carrier having a volume average particle diameter (D50) of 50 μm coated with 1.5% by mass of polymethyl methacrylate (manufactured by Soken Chemical Co., Ltd .: Mw = 76000) at a blending ratio shown in Table 3, an externally added toner, Was stirred and mixed with a V blender for 10 minutes to obtain a developer.

<Toner pigment aqueous dispersion (P)>
As a pigment, 50 parts of carbon black (“# 2600” (trade name), manufactured by Mitsubishi Chemical Corporation), 100 parts of a polyvinyl alcohol 10% aqueous solution (“GOHSENOL GL03”, manufactured by Nippon Synthetic Chemical Co., Ltd.), and sodium dodecylbenzenesulfonate 10 parts of a 10% aqueous solution and 200 parts of distilled water (referred to as “water” in Table 4) are added and dispersed using a homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) as a stirrer, and the pigment is added to water. A dispersed pigment aqueous dispersion (P) for toner was obtained. Table 4 shows the raw material components and the blending amount of the pigment aqueous dispersion (P) for toner.

<Pigment aqueous dispersion for toner (Q) to (S)>
As shown in Table 4, except that the pigment was changed, the toner pigment water dispersions (Q) to (S) in which the pigment was dispersed in water were prepared in the same manner as in the toner pigment water dispersion (P). Obtained.

(Comparative Examples 2-2 to 2-4)
As shown in Table 3, a toner and an externally added toner were obtained in the same manner as in Comparative Example 2-1, except that the pigment aqueous dispersion for toner was changed. Further, with the obtained externally added toner, a developer was prepared in the same manner as in Comparative Example 2-1. The volume average particle diameter of the obtained toner is also shown in Table 3.

<Evaluation method>
In the developers obtained in Examples 2-1 to 2-4 and Comparative Examples 2-1 to 2-4, the charging characteristics of the developers and the quality after printing using the developers were evaluated by the following methods. . The evaluation results are also shown in Table 3.
(1) Charging characteristics After measuring [Charging amount 1] in an environment of temperature / humidity = 25 ° C./55% RH, the developer is kept in a constant temperature / humidity chamber of temperature / humidity = 30 ° C./90% RH. After curing for 2 days, [charge amount 2] was measured, and the variation rate of the charge amount was evaluated.
As for the charge amount, 0.1 g of developer was sampled, and the value after nitrogen blowing for 1 minute with a blow-off charge amount measuring device “TB-200 type” (manufactured by Toshiba Chemical Co., Ltd.) was taken as the charge amount.
Charge amount fluctuation rate (%) = ([charge amount 1] − [charge amount 2]) / [charge amount 1] × 100

(2) Evaluation of color developability An image was output using a remodeled printer “DocuPrint C3250” manufactured by Fuji Xerox Co., Ltd. filled with a developer, and the image density was measured. As the recording medium, coated paper “Ncolor157” (fine coating mat) manufactured by Fuji Xerox Co., Ltd. was used, and evaluation was performed at a feeding speed of 160 mm / second and a fixing temperature of 180 ° C. The image density was measured by measuring the optical density (OD value) of the solid portion of the image using a Macbeth densitometer (model number “RD-19I”, manufactured by Sakata Inx Corporation).

  As is apparent from Table 3, the toners and developers of Examples 2-1 to 2-4 are more stable in charging characteristics than the toners and developers of Comparative Examples 2-1 to 2-4, and particularly high temperature. / It was confirmed that the quality after printing was stable and the color development of the image was excellent without significant decrease in chargeability even under high humidity.

  The toner colorant, toner, and developer of the present invention are excellent in charging characteristics and image coloration, and can be suitably used for full-color printing in which a plurality of toner layers need to be fixed on a recording medium.

Claims (10)

  A colorant for toner, comprising pigment particles dispersed in a polymer phase, and composite particles having at least one void formed therein.   The toner colorant according to claim 1, wherein the composite particles have an average particle diameter of 20 nm to 100 μm.   The colorant for toner according to claim 1, wherein the polymer phase constituting at least the surface layer portion of the composite particle includes a structural unit derived from a polymerizable crosslinkable monomer.   The toner according to any one of claims 1 to 3, wherein the content of the pigment particles in the composite particles is 3 to 80 parts by mass when the polymer constituting the polymer phase is 100 parts by mass. Coloring agent.   The coloring for toner according to any one of claims 1 to 4, wherein a ratio of a total volume occupied by voids of the composite particles is 5 to 90% by volume when the volume of the entire composite particles is 100% by volume. Agent.   The colorant for toner according to any one of claims 1 to 5, wherein the pigment particles comprise at least one selected from an azo pigment, a phthalocyanine pigment, and a polycyclic pigment.   The colorant for toner according to any one of claims 1 to 6, which is a colorant for polymerized toner.   7. A toner comprising at least a binder resin and a colorant, wherein the colorant is the toner colorant according to claim 1.   The toner according to claim 8, wherein the plurality of toner colorants are bound by a binding portion made of the binding resin.   A developer comprising the toner according to claim 8 or 9 and a carrier.