JP6359795B2 - Liquid developer - Google Patents

Description

  The present invention relates to a liquid developer.

  The liquid developer is a developer used in a development system using a wet electrophotographic system, and toner particles containing a colorant and a resin are dispersed in an insulating liquid. Toner particles contained in such a liquid developer are required to have various performances such as charging property, fixing property, and heat storage stability.

  For example, Patent Document 1 includes resin particles having a core-shell structure composed of one or more film-like shell layers containing a first resin and one core layer containing a second resin. A liquid developer is described. In this patent document, by setting the mass ratio of the shell layer and the core layer to 1:99 to 70:30, the particle size and shape of the resin particles become uniform and the heat-resistant storage stability of the toner particles is improved. Is described.

  In Patent Documents 2 to 3, the fixability of the toner particles is improved by adding 0.5 to 23 parts by weight of a liquid having a boiling point equal to or lower than that of the insulating liquid to 100 parts by weight of the toner particles. It is described.

JP 2009-96994 A JP 2010-224107 A JP 2010-224108 A

  In the liquid developer described in Patent Document 1, the toner particles are dispersed in the insulating liquid by the shell layer constituting the core / shell type structure, but there is a problem that the redispersibility of the toner particles is lowered. . That is, when the liquid developer described in Patent Document 1 is stored for a long period of time, the toner particles settle, and in some cases, a fine structure is formed. Even when the liquid developer is stirred by hand or the like, the settled state of the toner particles remains maintained. This is referred to herein as “the redispersibility of the toner particles is reduced”. On the other hand, even if the toner particles settle due to storage of the liquid developer for a long time, the state of the toner particles in the liquid developer is stored by performing a stirring operation such as shaking the liquid developer by hand. In this specification, returning to the previous state (dispersed state) is referred to as “excellent in redispersibility of toner particles”.

  In the liquid developers described in Patent Documents 2 to 3, toner particles are dispersed in an insulating liquid by a dispersant, and are excellent in redispersibility. However, when the liquid developer described in Patent Documents 2 to 3 is stored at a high temperature (for example, near the glass transition point Tg of the resin contained in the liquid developer or higher than Tg), it is found that the toner particles aggregate. It was. If a liquid developer is produced using a resin having a higher Tg, toner particles can be prevented from agglomerating even when the liquid developer is stored at a high temperature, but the fixing temperature is increased. , Fixing at low temperatures becomes difficult.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a liquid developer excellent in fixing property of toner particles at a low temperature and redispersibility of toner particles.

  The liquid developer according to the present invention includes toner particles dispersed in an insulating liquid. The toner particles have a core-shell structure in which the first particles containing the first resin are attached to or coated on the surfaces of the second particles containing the second resin. In the insulating liquid, 10 ppm to 1000 ppm of alcohol is dissolved with respect to the solid content of the toner particles. Here, the solid content of the toner particles means a portion obtained by removing the liquid component contained in the toner particles from the toner particles.

  The glass transition point of the first resin is preferably 50 ° C. or higher.

  The liquid developer according to the present invention has excellent fixability of toner particles at low temperature and excellent redispersibility of toner particles.

It is sectional drawing which shows an example of a structure of the measuring apparatus used for evaluation of charging property.

  Hereinafter, the present invention will be described in more detail. The liquid developer according to the present invention is not limited to the following liquid developer.

[Configuration of liquid developer]
The liquid developer according to the present embodiment is useful as a developer for an electrophotographic image forming apparatus, and toner particles (C) are dispersed in an insulating liquid (L). The toner particles (C) have a core-shell structure in which the first particles (A) containing the first resin (a) are attached or coated on the surfaces of the second particles (B) containing the second resin (b). Have. Hereinafter, “first resin (a)” and “first particle (A)” are referred to as “shell resin (a)” and “shell particle (A)”, respectively. Further, “second resin (b)” and “second particle (B)” are referred to as “core resin (b)” and “core particle (B)”, respectively.

  Specific examples of the shell resin (a) and the core resin (b) are as follows, but the core resin (b) is preferably melted at a lower temperature than the shell resin (a). Thereby, the toner particles (C) can be fixed at a relatively low temperature, and the heat-resistant storage stability of the toner particles (C) can be maintained.

  Specifically, when the core resin (b) melts at a lower temperature than the shell resin (a), the shell resin (a) is stored even if the liquid developer according to the present embodiment is stored at a high temperature (for example, 50 ° C. or higher). ) Can be prevented from melting. Therefore, aggregation of the toner particles (C) when stored at a high temperature can be prevented, so that the heat-resistant storage stability of the toner particles (C) can be maintained. Thereby, since it is not necessary to use a resin having a high melting point, fixing at a low temperature is possible. In this specification, “heat-resistant storage stability” means that the toner particles (C) in the insulating liquid (L) can be maintained in a dispersed state even when stored at a high temperature.

  In order to improve the fixing property of the toner particles (C) at a low temperature and maintain the heat-resistant storage stability of the toner particles (C), the glass transition point of the shell resin (a) (hereinafter referred to as “glass transition point”) is used. “It may be abbreviated as“ Tg ”) is preferably 50 ° C. or higher, and more preferably 55 ° C. or higher. Moreover, it is preferable that Tg of core resin (b) is 55 degreeC or more. If the Tg of the shell resin (a) is less than 50 ° C., the toner particles (C) may be aggregated when the liquid developer is stored at a high temperature.

  Each Tg of the shell resin (a) and the core resin (b) may be measured by a differential scanning calorimetry (DSC) method, or may be measured using a flow tester. When measuring Tg by the DSC method, for example, using a differential scanning calorimeter (such as “DSC20” or “SSC / 580” manufactured by Seiko Instruments Inc.), the method specified in ASTM D3418-82 is used. It is preferable to measure Tg in conformity.

When Tg is measured using a flow tester, it is preferable to use a Koka type flow tester (for example, “CFT500 type” manufactured by Shimadzu Corporation). An example of Tg measurement conditions in this case is shown below. Load: 3 MPa
Temperature increase rate: 3.0 ° C / min
Die diameter: 0.50mm
Die length: 10.0 mm.

  The Tg of the shell resin (a) is preferably measured in a state where the insulating liquid (L) (shell particles (A) are dispersed in the insulating liquid (L)) is evaporated. For example, after preparing the insulating liquid in which the shell particles (A) are dispersed, the prepared sample solution is dried in a vacuum state for 1 hour to completely volatilize the solvent from the sample solution. Tg of shell resin (a) is measured using solid content of shell resin (a) obtained by this volatilization.

  In the liquid developer according to the present embodiment, 10 ppm to 1000 ppm of alcohol is dissolved in the insulating liquid (L) with respect to the solid content of the toner particles (C). Thereby, the redispersibility of the liquid developer is improved. The reason is not clear, but it can be considered as follows. It is considered that when a predetermined amount of alcohol is dissolved in the insulating liquid (L), the surface of the toner particles (C) is modified by the alcohol. It is considered that when the surface of the toner particles (C) is modified, a cause (for example, electric charge) that causes a repulsive force between the toner particles (C) is generated on the surface of the toner particles (C). .

  The alcohol dissolved in the insulating liquid (L) is preferably an alcohol mixed with the insulating liquid, and is preferably an alcohol having a basic alcohol group. Specific examples of the alcohol include ethanol, propanol, butanol, methyl celsorb, and butyl celsolob. Among these, it is preferable to use ethanol or isopropanol in consideration of easiness of distillation and ease of handling. As the alcohol dissolved in the insulating liquid (L), the above-listed alcohols may be used alone, or two or more of the above-listed alcohols may be mixed and used.

  The content of the alcohol dissolved in the insulating liquid (L) is 10 ppm or more and 1000 ppm or less, preferably 30 ppm or more and 300 ppm or less, as described above, with respect to the solid content of the toner particles (C). If the content of the alcohol dissolved in the insulating liquid is less than 10 ppm based on the solid content of the toner particles, the effect obtained by dissolving the alcohol in the insulating liquid is small. It is difficult to sufficiently improve dispersibility. On the other hand, if the content of the alcohol dissolved in the insulating liquid exceeds 1000 ppm with respect to the solid content of the toner particles, the insulating liquid has an excessively high dielectric constant, so that the insulating property of the insulating liquid is impaired. There is. As a result, the chargeability of the toner particles decreases and it becomes difficult to obtain a high density image.

The content rate of the alcohol dissolved in the insulating liquid (L) can be measured using, for example, GCMS (gas chromatograph mass spectrometry). Specifically, the liquid developer according to the present embodiment is centrifuged, and the amount of alcohol in the supernatant can be measured according to the following measurement conditions using the following apparatus. Tograph mass spectrometer (GC-MSD (GC chromatograph with mass-selective detection) (“6890A / 5973N” manufactured by Agilent Technologies))
Gas chromatography column: DB-624 (manufactured by J & W Scientific) (column inner diameter: 0.025 (mm. ID), column length: 30 m, film thickness: 1.4 μm)
Temperature of the above column: maintained at 40 ° C. for 5 minutes, then heated up at a rate of 10 ° C./minute, and then maintained at 230 ° C. for 5 minutes. Sample solution: toluene solution Detection method: EI (electron ionization)
Mass range to scan: m / z (mass-to-charge ratio) = 33-100.

[Configuration of toner particles]
<Shell resin (a)>
The shell resin (a) in the present embodiment may be a thermoplastic resin or a thermosetting resin. Examples of the shell resin (a) include vinyl resin, polyester resin, polyurethane resin, epoxy resin, polyamide resin, polyimide resin, silicon resin, phenol resin, melamine resin, urea resin, aniline resin, ionomer resin, and polycarbonate resin. Etc. As the shell resin (a), two or more of the above listed resins may be used in combination.

  From the viewpoint that the liquid developer according to the present embodiment is easily obtained, as the shell resin (a), preferably, at least one of a vinyl resin, a polyester resin, a polyurethane resin, and an epoxy resin is used. More preferably, at least one of a polyester resin and a polyurethane resin is used.

<Vinyl resin>
The vinyl resin may be a polymer obtained by homopolymerizing a monomer having a polymerizable double bond, or two or more monomers having a polymerizable double bond may be copolymerized. The obtained copolymer may be used. Examples of the monomer having a polymerizable double bond include the following (1) to (9).

(1) Hydrocarbon having a polymerizable double bond The hydrocarbon having a polymerizable double bond is, for example, an aliphatic hydrocarbon having a polymerizable double bond represented by the following (1-1) or the following (1 -2) is preferably an aromatic hydrocarbon having a polymerizable double bond.

(1-1) Aliphatic hydrocarbon having a polymerizable double bond An aliphatic hydrocarbon having a polymerizable double bond is, for example, a chain having a polymerizable double bond represented by the following (1-1-1). It is preferably a hydrocarbon or a cyclic hydrocarbon having a polymerizable double bond represented by the following (1-1-2).

(1-1-1) Chain hydrocarbon having a polymerizable double bond Examples of the chain hydrocarbon having a polymerizable double bond include alkenes having 2 to 30 carbon atoms (for example, ethylene, propylene, butene). , Isobutylene, pentene, heptene, diisobutylene, octene, dodecene or octadecene); alkadienes having 4 to 30 carbon atoms (for example, butadiene, isoprene, 1,4-pentadiene, 1,5-hexadiene or 1,7-octadiene) Etc.).

(1-1-2) Cyclic hydrocarbon having a polymerizable double bond Examples of the cyclic hydrocarbon having a polymerizable double bond include mono- or dicycloalkene having 6 to 30 carbon atoms (for example, cyclohexene, vinyl, etc.). Cyclohexene or ethylidenebicycloheptene); mono- or dicycloalkadiene having 5 to 30 carbon atoms (for example, monocyclopentadiene or dicyclopentadiene) and the like.

(1-2) Aromatic hydrocarbon having a polymerizable double bond As an aromatic hydrocarbon having a polymerizable double bond, for example, styrene; hydrocarbyl of styrene (for example, alkyl having 1 to 30 carbon atoms) , Cycloalkyl, aralkyl and / or alkenyl) substituted (eg, α-methyl styrene, vinyl toluene, 2,4-dimethyl styrene, ethyl styrene, isopropyl styrene, butyl styrene, phenyl styrene, cyclohexyl styrene, benzyl styrene, crotyl) Benzene, divinylbenzene, divinyltoluene, divinylxylene or trivinylbenzene); and vinylnaphthalene.

(2) Monomers having a carboxyl group and a polymerizable double bond and salts thereof Examples of the monomer having a carboxyl group and a polymerizable double bond include unsaturated monocarboxylic acids having 3 to 15 carbon atoms. [For example, (meth) acrylic acid, crotonic acid, isocrotonic acid, cinnamic acid, etc.]; unsaturated dicarboxylic acid having 3 to 30 carbon atoms (anhydride) [for example, (anhydrous) maleic acid, fumaric acid, itaconic acid, (Anhydrous) citraconic acid or mesaconic acid, etc.]; monoalkyl (1-10 carbon atoms) ester of unsaturated dicarboxylic acid having 3 to 10 carbon atoms (for example, maleic acid monomethyl ester, maleic acid monodecyl ester, fumaric acid) Monoethyl ester, itaconic acid monobutyl ester, citraconic acid monodecyl ester, etc.). As used herein, “(meth) acrylic acid” means acrylic acid and / or methacrylic acid.

  Examples of the salt of the monomer include alkali metal salts (for example, sodium salt or potassium salt), alkaline earth metal salts (for example, calcium salt or magnesium salt), ammonium salts, amine salts, and 4 A grade ammonium salt etc. are mentioned.

  The amine salt is not particularly limited as long as it is an amine compound. For example, primary amine salt (for example, ethylamine salt, butylamine salt or octylamine salt); secondary amine salt (for example, diethylamine salt or dibutylamine salt) ); Tertiary amine salts (for example, triethylamine salt or tributylamine salt) and the like.

  Examples of the quaternary ammonium salt include tetraethylammonium salt, triethyllaurylammonium salt, tetrabutylammonium salt and tributyllaurylammonium salt.

  Examples of the salt of the monomer having a carboxyl group and a polymerizable double bond include sodium acrylate, sodium methacrylate, monosodium maleate, disodium maleate, potassium acrylate, potassium methacrylate, monopotassium maleate. , Lithium acrylate, cesium acrylate, ammonium acrylate, calcium acrylate, and aluminum acrylate.

(3) Monomers having a sulfo group and a polymerizable double bond and salts thereof Examples of the monomer having a sulfo group and a polymerizable double bond include alkene sulfonic acids having 2 to 14 carbon atoms [for example, , Vinyl sulfonic acid, (meth) allyl sulfonic acid or methyl vinyl sulfonic acid]; styrene sulfonic acid and alkyl derivatives of styrene sulfonic acid (having 2 to 24 carbon atoms) (for example, α-methyl styrene sulfonic acid, etc.); carbon Sulfo (hydroxy) alkyl- (meth) acrylate having a number of 5 to 18 [for example, sulfopropyl (meth) acrylate, 2-hydroxy-3- (meth) acryloxypropylsulfonic acid, 2- (meth) acryloyloxyethanesulfone Acid or 3- (meth) acryloyloxy-2-hydroxypropanesulfonic acid, etc. ] C5-C18 sulfo (hydroxy) alkyl (meth) acrylamide [for example, 2- (meth) acryloylamino-2,2-dimethylethanesulfonic acid, 2- (meth) acrylamide-2-methylpropanesulfone Acid or 3- (meth) acrylamide-2-hydroxypropanesulfonic acid]; alkyl (having 3 to 18 carbon atoms) allylsulfosuccinic acid (for example, propylallylsulfosuccinic acid, butylallylsulfosuccinic acid or 2-ethylhexyl-allylsulfosuccinic acid) Poly [n (“n” represents the degree of polymerization; the same shall apply hereinafter) = 2 to 30] oxyalkylene (for example, oxyethylene, oxypropylene, oxybutylene, etc.). Can be combined, It may be a copolymer of salkylene.When polyoxyalkylene is a copolymer of oxyalkylene, it may be a random polymer or a block polymer.); Sulfuric acid ester of meth) acrylate [for example, poly (n = 5-15) oxyethylene monomethacrylate sulfuric acid ester or poly (n = 5-15) oxypropylene monomethacrylate sulfuric acid ester]; chemical formulas (1) to (3) below The compound etc. which are represented by these are mentioned.

In the above chemical formulas (1) to (3), R ¹ represents an alkylene group having 2 to 4 carbon atoms. If the formula (1) contains two or more R ¹ O, 2 or more R ¹ O may be constructed using the same alkylene groups, two or more alkylene groups is constructed by combination Also good. When two or more kinds of alkylene groups are used in combination, the sequence of R ¹ in the chemical formula (1) may be a random sequence or a block sequence. R ² and R ³ each independently represents an alkyl group having 1 to 15 carbon atoms. m and n are each independently an integer of 1 to 50. Ar represents a benzene ring. R ⁴ represents an alkyl group having 1 to 15 carbon atoms which may be substituted with a fluorine atom.

  Examples of the salt of the monomer having a sulfo group and a polymerizable double bond are listed as “the salt of the monomer” in “(2) Monomer having a carboxyl group and a polymerizable double bond” above. Salt.

(4) Monomer having phosphono group and polymerizable double bond and salt thereof Examples of the monomer having phosphono group and polymerizable double bond include (meth) acryloyloxyalkyl phosphate monoester (alkyl group) 1 to 24) [for example, 2-hydroxyethyl (meth) acryloyl phosphate or phenyl-2-acryloyloxyethyl phosphate, etc.]; (meth) acryloyloxyalkylphosphonic acid (the alkyl group has 1 to 2 carbon atoms) 24) (for example, 2-acryloyloxyethylphosphonic acid, etc.) and the like.

  Examples of the salt of the monomer having a phosphono group and a polymerizable double bond are listed as “the salt of the monomer” in “(2) Monomer having a carboxyl group and a polymerizable double bond”, for example. Salt.

(5) Monomer having a hydroxyl group and a polymerizable double bond Examples of the monomer having a hydroxyl group and a polymerizable double bond include hydroxystyrene, N-methylol (meth) acrylamide, and hydroxyethyl (meth). Acrylate, hydroxypropyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, (meth) allyl alcohol, crotyl alcohol, isocrotyl alcohol, 1-buten-3-ol, 2-buten-1-ol, 2- Examples include butene-1,4-diol, propargyl alcohol, 2-hydroxyethylpropenyl ether, and sucrose allyl ether.

(6) Nitrogen-containing monomer having a polymerizable double bond As the nitrogen-containing monomer having a polymerizable double bond, for example, monomers shown in the following (6-1) to (6-4) are: Can be mentioned.

(6-1) Monomer having an amino group and a polymerizable double bond Examples of the monomer having an amino group and a polymerizable double bond include aminoethyl (meth) acrylate and dimethylaminoethyl (meth) acrylate. , Diethylaminoethyl (meth) acrylate, t-butylaminoethyl methacrylate, N-aminoethyl (meth) acrylamide, (meth) allylamine, morpholinoethyl (meth) acrylate, 4-vinylpyridine, 2-vinylpyridine, crotylamine, N, N-dimethylaminostyrene, methyl-α-acetaminoacrylate, vinylimidazole, N-vinylpyrrole, N-vinylthiopyrrolidone, N-arylphenylenediamine, aminocarbazole, aminothiazole, aminoindole, aminopyrrole, aminoethyl Examples include midazole and aminomercaptothiazole.

  The monomer having an amino group and a polymerizable double bond may be a salt of the monomers listed above. Examples of the salt of the monomer listed above include salts listed as “salt of the monomer” in “(2) monomer having a carboxyl group and a polymerizable double bond”.

(6-2) Monomer having an amide group and a polymerizable double bond Examples of the monomer having an amide group and a polymerizable double bond include (meth) acrylamide, N-methyl (meth) acrylamide, N -Butylacrylamide, diacetone acrylamide, N-methylol (meth) acrylamide, N, N'-methylene-bis (meth) acrylamide, cinnamic amide, N, N-dimethylacrylamide, N, N-dibenzylacrylamide, methacrylformamide , N-methyl-N-vinylacetamide, N-vinylpyrrolidone and the like.

(6-3) A monomer having 3 to 10 carbon atoms having a nitrile group and a polymerizable double bond As a monomer having 3 to 10 carbon atoms having a nitrile group and a polymerizable double bond, for example, (Meth) acrylonitrile, cyanostyrene, cyanoacrylate, and the like.

(6-4) Monomers having 8 to 12 carbon atoms having a nitro group and a polymerizable double bond As monomers having 8 to 12 carbon atoms having a nitro group and a polymerizable double bond, for example, Nitrostyrene etc. are mentioned.

(7) Monomers having 6 to 18 carbon atoms having an epoxy group and a polymerizable double bond Examples of monomers having 6 to 18 carbon atoms having an epoxy group and a polymerizable double bond include glycidyl ( And (meth) acrylate.

(8) Monomers having 2 to 16 carbon atoms having a halogen element and a polymerizable double bond Examples of monomers having 2 to 16 carbon atoms having a halogen element and a polymerizable double bond include vinyl chloride. , Vinyl bromide, vinylidene chloride, allyl chloride, chlorostyrene, bromostyrene, dichlorostyrene, chloromethylstyrene, tetrafluorostyrene and chloroprene.

(9) Others Examples of the monomer having a polymerizable double bond include the monomers shown in the following (9-1) to (9-4) in addition to the above monomers.

(9-1) Ester having 4 to 16 carbon atoms having a polymerizable double bond Examples of the ester having 4 to 16 carbon atoms having a polymerizable double bond include vinyl acetate; vinyl propionate; vinyl butyrate; Diallyl phthalate; diallyl adipate; isopropenyl acetate; vinyl methacrylate; methyl-4-vinyl benzoate; cyclohexyl methacrylate; benzyl methacrylate; phenyl (meth) acrylate; vinyl methoxyacetate; vinyl benzoate; ethyl-α-ethoxy acrylate; Alkyl (meth) acrylates having an alkyl group of ~ 11 [e.g. methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate or 2-ethylhexyl (Meth) acrylates and the like]; dialkyl fumarate (the two alkyl groups are a linear alkyl group having 2 to 8 carbon atoms, a branched alkyl group or an alicyclic alkyl group); a dialkyl maleate (2 The alkyl group is a linear alkyl group having 2 to 8 carbon atoms, a branched alkyl group or an alicyclic alkyl group); poly (meth) allyloxyalkanes (for example, diaryloxyethane, trialkyl) Allyloxyethane, tetraallyloxyethane, tetraallyloxypropane, tetraallyloxybutane or tetrametaallyloxyethane); a monomer having a polyalkylene glycol chain and a polymerizable double bond {eg, polyethylene glycol [number average Molecular weight (hereinafter abbreviated as “Mn”) = 300] mono (meth) acrylate, polypropylene glycol (Mn 500) monoacrylate, methyl alcohol ethylene oxide (hereinafter, “ethylene oxide” is abbreviated as “EO”) 10 mol adduct (meth) acrylate or lauryl alcohol EO 30 mol adduct (meth) acrylate, etc.}; poly (meth) acrylate {E.g. poly (meth) acrylates of polyhydric alcohols [e.g. ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate Or polyethylene glycol di (meth) acrylate and the like]} and the like.

(9-2) Ether having 3 to 16 carbon atoms having a polymerizable double bond Examples of the ether having 3 to 16 carbon atoms having a polymerizable double bond include vinyl methyl ether, vinyl ethyl ether, and vinyl propyl. Ether, vinyl butyl ether, vinyl-2-ethylhexyl ether, vinyl phenyl ether, vinyl-2-methoxyethyl ether, methoxybutadiene, vinyl-2-butoxyethyl ether, 3,4-dihydro-1,2-pyran, 2-butoxy -2'-vinyloxy diethyl ether, acetoxy styrene, phenoxy styrene and the like.

(9-3) Ketone having 4 to 12 carbon atoms having a polymerizable double bond Examples of the ketone having 4 to 12 carbon atoms having a polymerizable double bond include vinyl methyl ketone, vinyl ethyl ketone and vinyl phenyl. Examples include ketones.

(9-4) Sulfur-containing compound having 2 to 16 carbon atoms having a polymerizable double bond Examples of the sulfur-containing compound having 2 to 16 carbon atoms having a polymerizable double bond include divinyl sulfide and p-vinyl diphenyl sulfide. , Vinyl ethyl sulfide, vinyl ethyl sulfone, divinyl sulfone and divinyl sulfoxide.

  Specific examples of the vinyl resin include, for example, a styrene- (meth) acrylic acid ester copolymer, a styrene-butadiene copolymer, a (meth) acrylic acid- (meth) acrylic acid ester copolymer, and a styrene-acrylonitrile copolymer. Copolymers, styrene- (maleic anhydride) copolymers, styrene- (meth) acrylic acid copolymers, styrene- (meth) acrylic acid-divinylbenzene copolymers, and styrene-styrenesulfonic acid- (meth) acrylic acid esters A copolymer etc. are mentioned.

  The vinyl resin may be a homopolymer or copolymer of a monomer having a polymerizable double bond as described in (1) to (9) above, or may be polymerized as described in (1) to (9) above. A polymer obtained by polymerizing a monomer having a double bond and a monomer (m) having a polymerizable double bond having a molecular chain (k) may be used. Examples of the molecular chain (k) include a linear or branched hydrocarbon chain having 12 to 27 carbon atoms, a fluoroalkyl chain having 4 to 20 carbon atoms, and a polydimethylsiloxane chain. The difference in SP value (solubility parameter) between the molecular chain (k) in the monomer (m) and the insulating liquid (L) is preferably 2 or less. In the present specification, the “SP value” is a method by Fedors [Polym. Eng. Sci. 14 (2) 152, (1974)].

  Although it does not specifically limit as a monomer (m) which has a polymerizable double bond which has a molecular chain (k), For example, the following monomers (m1)-(m4) etc. are mentioned. As the monomer (m), two or more monomers (m1) to (m4) may be used in combination.

Monomer (m1) having a linear hydrocarbon chain having 12 to 27 carbon atoms (preferably 16 to 25 carbon atoms) and a polymerizable double bond
Examples of such a monomer (m1) include mono-linear alkyl of unsaturated monocarboxylic acid (alkyl having 12 to 27 carbon atoms) ester and mono-linear alkyl of unsaturated dicarboxylic acid (alkyl Examples thereof include esters having 12 to 27 carbon atoms. Examples of the unsaturated monocarboxylic acid and unsaturated dicarboxylic acid include (meth) acrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, citraconic acid, and other carboxyl group-containing vinyl monomers having 3 to 24 carbon atoms. Examples include masses.

  Specific examples of the monomer (m1) include, for example, dodecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate and ( (E.g., meta) eicosyl acrylate.

Monomer (m2) having a branched hydrocarbon chain having 12 to 27 carbon atoms (preferably 16 to 25 carbon atoms) and a polymerizable double bond
Examples of such a monomer (m2) include a branched alkyl of an unsaturated monocarboxylic acid (alkyl having 12 to 27 carbon atoms) and a monobranched alkyl of an unsaturated dicarboxylic acid (the carbon number of alkyl is 12-27) Ester etc. are mentioned. As said unsaturated monocarboxylic acid and unsaturated dicarboxylic acid, the thing similar to what was enumerated as a specific example of unsaturated monocarboxylic acid and unsaturated dicarboxylic acid in a monomer (m1) is mentioned, for example.

  Specific examples of the monomer (m2) include, for example, 2-decyltetradecyl (meth) acrylate.

Monomer (m3) having a fluoroalkyl chain having 4 to 20 carbon atoms and a polymerizable double bond
Examples of such a monomer (m3) include perfluoroalkyl (alkyl) (meth) acrylic acid ester represented by the following chemical formula (4). CH ₂ = CR—COO— (CH ₂ ) _{p - (CF 3) q -Z} : formula (4)
In the chemical formula (4), R represents a hydrogen atom or a methyl group, p is an integer of 0 to 3, q is any of 2, 4, 6, 8, 10 or 12, and Z is a hydrogen atom. Or represents a fluorine atom.

  Specific examples of the monomer (m3) include, for example, [(2-perfluoroethyl) ethyl] (meth) acrylic acid ester, [(2-perfluorobutyl) ethyl] (meth) acrylic acid ester, [( 2-perfluorohexyl) ethyl] (meth) acrylate, [(2-perfluorooctyl) ethyl] (meth) acrylate, [(2-perfluorodecyl) ethyl] (meth) acrylate, and , [(2-perfluorododecyl) ethyl] (meth) acrylic acid ester, and the like.

Monomer having polydimethylsiloxane chain and polymerizable double bond (m4)
Such monomers (m4), for example, represented by the following chemical formula (5) (meth) acrylic-modified silicones _{CH 2 = CR-COO - (} (CH 3) 2 SiO) m - Si (CH ₃ ) ₃ : Chemical formula (5)
In the chemical formula (5), R represents a hydrogen atom or a methyl group, and m is an average value of 15 to 45.

  Specific examples of the monomer (m4) include, for example, modified silicone oil (for example, “X-22-174DX”, “X-22-2426” or “X-22-2475” manufactured by Shin-Etsu Silicone Co., Ltd.). Etc.).

  Among the monomers (m1) to (m4), preferable monomers are the monomer (m1) and the monomer (m2), and more preferable monomer is the monomer (m2).

  The content of the monomer (m) is preferably 10 to 90% by mass, more preferably 15 to 80% by mass, and further preferably 20 to 60% by mass with respect to the mass of the vinyl resin. . When the content of the monomer (m) is within the above range, the toner particles (C) are difficult to unite.

  When the monomer having the polymerizable double bond (1) to (9), the monomer (m1), and the monomer (m2) are polymerized to form a vinyl resin, the monomer The mass ratio [(m1) :( m2)] of (m1) to the monomer (m2) is preferably 90 from the viewpoint of the particle size distribution of the toner particles (C) and the fixability of the toner particles (C). : 10 to 10:90, more preferably 80:20 to 20:80, and still more preferably 70:30 to 30:70.

<Polyester resin>
Examples of polyester resins include polycondensates of polyols with polycarboxylic acids, acid anhydrides of polycarboxylic acids, or lower alkyl (alkyl group having 1 to 4 carbon atoms) esters of polycarboxylic acids. A known polycondensation catalyst or the like can be used for the polycondensation reaction.

  Examples of the polyol include diol (10) and polyol (11) having a valence of 3 to 8 or more (hereinafter abbreviated as “polyol (11)”).

  Examples of the polycarboxylic acid include dicarboxylic acid (12) and polycarboxylic acid (13) having a valence of 3 to 6 or more (hereinafter abbreviated as “polycarboxylic acid (13)”). Is mentioned. Examples of the acid anhydride of polycarboxylic acid include an acid anhydride of dicarboxylic acid (12) and an acid anhydride of polycarboxylic acid (13). Examples of the lower alkyl ester of polycarboxylic acid include a lower alkyl ester of dicarboxylic acid (12) and a lower alkyl ester of polycarboxylic acid (13).

  The ratio of polyol and polycarboxylic acid is not particularly limited. The equivalent ratio of hydroxyl group [OH] to carboxyl group [COOH] ([OH] / [COOH]) is preferably 2/1 to 1/5, more preferably 1.5 / 1 to 1/4. The ratio between the polyol and the polycarboxylic acid may be set so that the ratio is more preferably 1.3 / 1 to 1/3.

  Examples of the diol (10) include alkylene glycols having 2 to 30 carbon atoms (for example, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexane). Diols, octanediols, decanediols, dodecanediols, tetradecanediols, neopentyl glycols or 2,2-diethyl-1,3-propanediols); alkylene ether glycols with Mn = 106-10000 (eg diethylene glycol, triethylene glycol, Dipropylene glycol, polyethylene glycol, polypropylene glycol or polytetramethylene ether glycol); alicyclic diols having 6 to 24 carbon atoms (for example, 1,4-cyclohexanedi) An alkylene oxide (hereinafter referred to as “alkylene oxide” is abbreviated as “AO”) adduct (the number of added moles is 2 to 100) (for example, 2 to 100) 1,4-cyclohexanedimethanol EO 10 mol adduct, etc.); bisphenols having 15 to 30 carbon atoms (for example, bisphenol A, bisphenol F or bisphenol S) AO [for example, EO, propylene oxide (hereinafter referred to as “PO”) Abbreviation) or butylene oxide] addition products (2 to 100 moles of addition) or polyphenols having 12 to 24 carbon atoms (for example, catechol, hydroquinone, resorcin, etc.) AO addition products (for example, EO2 of bisphenol A) Mole adduct or PO2-4 mol adduct of bisphenol A); weight average molecular weight (hereinafter abbreviated as “Mw”) = 100-5000 polylactone diol (for example, poly-ε-caprolactone diol, etc.); -20,000 polybutadiene diol and the like.

  Of these, the diol (10) is preferably an AO adduct of alkylene glycol and bisphenols, more preferably an AO adduct of bisphenols alone or a mixture of an AO adduct of bisphenols and an alkylene glycol.

  Examples of the polyol (11) include aliphatic polyhydric alcohols having a valence of 3 to 8 or more and a carbon number of 3 to 10 (for example, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, Sorbitan or sorbitol, etc.); AO (2 to 4 carbon atoms) adduct (2 to 100 carbon atoms) of trisphenol having 25 to 50 carbon atoms (for example, 2 to 4 mol adduct of trisphenol EO or trisphenol) Polyamide PO 2-4 mol adduct, etc.); n = 3-50 novolak resin (eg phenol novolac or cresol novolac, etc.) AO (carbon number 2-4) adduct (addition mol number 2-100) (eg , Phenol novolac PO2 molar adduct or phenol novolac EO4 AO (carbon number is 2 to 4) adduct (addition mole number is 2) of polyphenols having 6 to 30 carbon atoms (for example, pyrogallol, phloroglucinol or 1,2,4-benzenetriol). ˜100) (eg, pyrogallol EO 4 mole adduct, etc.); n = 20-2000 acrylic polyol {eg, monomer having hydroxyethyl (meth) acrylate and other polymerizable double bond [eg, styrene, ( And the like) and the like.

  Of these, the polyol (11) is preferably an aliphatic polyhydric alcohol and an AO adduct of a novolac resin, and more preferably an AO adduct of a novolac resin.

  Examples of the dicarboxylic acid (12) include alkane dicarboxylic acids having 4 to 32 carbon atoms (for example, succinic acid, adipic acid, sebacic acid, azelaic acid, dodecanedicarboxylic acid or octadecanedicarboxylic acid); 32 alkene dicarboxylic acids (eg maleic acid, fumaric acid, citraconic acid or mesaconic acid); branched alkenedicarboxylic acids having 8 to 40 carbon atoms [eg dimer acid or alkenyl succinic acid (eg dodecenyl succinic acid, penta Decenyl succinic acid or octadecenyl succinic acid etc.]]; branched alkanedicarboxylic acids having 12 to 40 carbon atoms [eg alkyl succinic acid (eg decyl succinic acid, dodecyl succinic acid or octadecyl succinic acid etc.) etc. ]; Carbon number 8-20 Aromatic dicarboxylic acids (e.g., phthalic acid, isophthalic acid, terephthalic acid or naphthalene dicarboxylic acid) and the like.

  Of these, preferred as the dicarboxylic acid (12) are alkene dicarboxylic acids and aromatic dicarboxylic acids, and more preferred are aromatic dicarboxylic acids.

  Examples of the polycarboxylic acid (13) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid or pyromellitic acid).

  Examples of the acid anhydride of dicarboxylic acid (12) and polycarboxylic acid (13) include trimellitic acid anhydride and pyromellitic acid anhydride. Examples of lower alkyl esters of dicarboxylic acid (12) and polycarboxylic acid (13) include methyl ester, ethyl ester, and isopropyl ester.

<Polyurethane resin>
Examples of the polyurethane resin include polyisocyanate (14) and active hydrogen-containing compound {for example, water; polyol [for example, diol (10) (including diol having a functional group other than hydroxyl group) or polyol (11), etc.] Polycarboxylic acid [for example, dicarboxylic acid (12) or polycarboxylic acid (13)]; polyester polyol obtained by polycondensation of polyol and polycarboxylic acid; ring-opening polymer of lactone having 6 to 12 carbon atoms; Polyamine (15); polythiol (16); a combination of these and the like}, or a terminal isocyanate group prepolymer obtained by reacting polyisocyanate (14) with the active hydrogen-containing compound. And the isocyanate group of the terminal isocyanate group prepolymer To be a primary and / or secondary monoamine (17) and the amino group-containing polyurethane resin obtained by reaction of equivalent amounts.

  The content of carboxyl groups in the polyurethane resin is preferably 0.1 to 10% by mass.

  Examples of the polyisocyanate (14) include aromatic polyisocyanates having 6 to 20 carbon atoms (excluding carbon in the NCO group; the same applies to <polyurethane resin> hereinafter); aliphatic having 2 to 18 carbon atoms. Polyisocyanates; modified products of these polyisocyanates (for example, modified products containing urethane groups, carbodiimide groups, allophanate groups, urea groups, burette groups, uretdione groups, uretoimine groups, isocyanurate groups or oxazolidone groups); The combined use etc. of a seed or more is mentioned.

  Examples of the aromatic polyisocyanate include 1,3- or 1,4-phenylene diisocyanate; 2,4- or 2,6-tolylene diisocyanate (hereinafter abbreviated as “TDI”); crude TDI; m- or p -Xylylene diisocyanate; α, α, α ', α'-tetramethylxylylene diisocyanate; 2,4'- or 4,4'-diphenylmethane diisocyanate (hereinafter abbreviated as "MDI"); crude MDI {for example, crude Diaminophenylmethane [For example, a condensation product of formaldehyde and an aromatic amine (one or two or more may be used in combination), or diaminodiphenylmethane and a small amount (for example, 5 to 20% by mass) A mixture with a polyamine having three or more amine groups, or the like, or 1,5-naphthylene diisocyanate; 4,4 ′, 4 ″ -triphenylmethane triisocyanate; m- or p-isocyanatophenylsulfonyl isocyanate; a combination of two or more of these .

  Examples of the aliphatic polyisocyanate include a chain aliphatic polyisocyanate and a cyclic aliphatic polyisocyanate.

  Examples of the chain aliphatic polyisocyanate include ethylene diisocyanate; tetramethylene diisocyanate; hexamethylene diisocyanate (hereinafter abbreviated as “HDI”); dodecamethylene diisocyanate; 1,6,11-undecane triisocyanate; -Trimethylhexamethylene diisocyanate; lysine diisocyanate; 2,6-diisocyanatomethylcaproate; bis (2-isocyanatoethyl) fumarate; bis (2-isocyanatoethyl) carbonate; 2-isocyanatoethyl-2,6- Diisocyanatohexanoate; these 2 or more types combined use etc. are mentioned.

  Examples of cycloaliphatic polyisocyanates include isophorone diisocyanate (hereinafter abbreviated as “IPDI”); dicyclohexylmethane-4,4′-diisocyanate (hydrogenated MDI); cyclohexylene diisocyanate; methylcyclohexylene diisocyanate (hydrogenated TDI). Bis (2-isocyanatoethyl) -4-cyclohexene-1,2-dicarboxylate; 2,5- or 2,6-norbornane diisocyanate; a combination of two or more of these.

  Examples of the modified polyisocyanate include a polyisocyanate compound containing at least one of a urethane group, a carbodiimide group, an allophanate group, a urea group, a burette group, a uretdione group, a uretoimine group, an isocyanurate group, and an oxazolidone group. Examples of modified polyisocyanates include, for example, modified MDI (for example, urethane-modified MDI, carbodiimide-modified MDI, or trihydrocarbyl phosphate-modified MDI); urethane-modified TDI; a combination of two or more of these [for example, modified MDI and urethane-modified TDI (For example, combined use with an isocyanate-containing prepolymer, etc.).

  Of these, the polyisocyanate (14) is preferably an aromatic polyisocyanate having 6 to 15 carbon atoms and an aliphatic polyisocyanate having 4 to 15 carbon atoms, and more preferably TDI, MDI, HDI, Hydrogenated MDI and IPDI.

  Examples of the polyamine (15) include an aliphatic polyamine having 2 to 18 carbon atoms and an aromatic polyamine (for example, having 6 to 20 carbon atoms).

  Examples of the aliphatic polyamine having 2 to 18 carbon atoms include, for example, a chain aliphatic polyamine; a chain aliphatic polyamine alkyl (1 to 4 carbon atoms) substituted; a chain aliphatic polyamine hydroxyalkyl (carbon number). 2-4) Substituents; cycloaliphatic polyamines and the like.

  Examples of chain aliphatic polyamines include alkylene diamines having 2 to 12 carbon atoms (for example, ethylene diamine, propylene diamine, trimethylene diamine, tetramethylene diamine or hexamethylene diamine); polyalkylenes (having 2 to 6 carbon atoms). ) Polyamines [for example, diethylenetriamine, iminobispropylamine, bis (hexamethylene) triamine, triethylenetetramine, tetraethylenepentamine or pentaethylenehexamine] and the like.

  Examples of the alkyl (substituted carbon number of 1 to 4) substituted chain aliphatic polyamine and the hydroxyalkyl (chained carbon number 2 to 4) substituted chain aliphatic polyamine include dialkyl (carbon number of 1 to 3). Examples include aminopropylamine; trimethylhexamethylenediamine; aminoethylethanolamine; 2,5-dimethyl-2,5-hexamethylenediamine; methyliminobispropylamine.

  Examples of the cycloaliphatic polyamine include alicyclic polyamines having 4 to 15 carbon atoms [for example, 1,3-diaminocyclohexane, isophoronediamine, mensendiamine, 4,4′-methylenedicyclohexanediamine (hydrogenated methylene). Dianiline) or 3,9-bis (3-aminopropyl) -2,4,8,10-tetraoxaspiro [5,5] undecane and the like]; a heterocyclic polyamine having 4 to 15 carbon atoms [for example, Piperazine, N-aminoethylpiperazine, 1,4-diaminoethylpiperazine, 1,4-bis (2-amino-2-methylpropyl) piperazine, etc.].

  Examples of the aromatic polyamine (having 6 to 20 carbon atoms) include, for example, unsubstituted aromatic polyamines; alkyl groups (for example, methyl groups, ethyl groups, n- or isopropyl groups, and butyl groups having 1 to 4 carbon atoms). Aromatic polyamine having an alkyl group); aromatic polyamine having an electron withdrawing group (for example, a halogen atom such as Cl, Br, I and F, an alkoxy group such as a methoxy group and an ethoxy group, and a nitro group); And aromatic polyamine having a group.

  Non-substituted aromatic polyamines include, for example, 1,2-, 1,3- or 1,4-phenylenediamine; 2,4′- or 4,4′-diphenylmethanediamine; crude diphenylmethanediamine (for example, polyphenylpolyamine). Methylenepolyamine); diaminodiphenylsulfone; benzidine; thiodianiline; bis (3,4-diaminophenyl) sulfone; 2,6-diaminopyridine; m-aminobenzylamine; triphenylmethane-4,4 ′, 4 ″ -triamine; Naphthylenediamine; a combination of two or more of these.

  Examples of the aromatic polyamine having an alkyl group (for example, an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, an n- or isopropyl group, and a butyl group) include 2,4- or 2,6- Tolylenediamine, crude tolylenediamine, diethyltolylenediamine, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-bis (o-toluidine), dianisidine, diaminoditolylsulfone, 1, 3-dimethyl-2,4-diaminobenzene, 1,3-diethyl-2,4-diaminobenzene, 1,3-dimethyl-2,6-diaminobenzene, 1,4-diethyl-2,5-diaminobenzene, 1,4-diisopropyl-2,5-diaminobenzene, 1,4-dibutyl-2,5-diaminobenzene, 2,4-diamino Citylene, 1,3,5-triethyl-2,4-diaminobenzene, 1,3,5-triisopropyl-2,4-diaminobenzene, 1-methyl-3,5-diethyl-2,4-diaminobenzene, 1-methyl-3,5-diethyl-2,6-diaminobenzene, 2,3-dimethyl-1,4-diaminonaphthalene, 2,6-dimethyl-1,5-diaminonaphthalene, 2,6-diisopropyl-1 , 5-diaminonaphthalene, 2,6-dibutyl-1,5-diaminonaphthalene, 3,3 ′, 5,5′-tetramethylbenzidine, 3,3 ′, 5,5′-tetraisopropylbenzidine, 3,3 ', 5,5'-tetramethyl-4,4'-diaminodiphenylmethane, 3,3', 5,5'-tetraethyl-4,4'-diaminodiphenylmethane, 3,3 ', 5 5′-tetraisopropyl-4,4′-diaminodiphenylmethane, 3,3 ′, 5,5′-tetrabutyl-4,4′-diaminodiphenylmethane, 3,5-diethyl-3′-methyl-2 ′, 4- Diaminodiphenylmethane, 3,5-diisopropyl-3′-methyl-2 ′, 4-diaminodiphenylmethane, 3,3′-diethyl-2,2′-diaminodiphenylmethane, 4,4′-diamino-3,3′-dimethyl Diphenylmethane, 3,3 ′, 5,5′-tetraethyl-4,4′-diaminobenzophenone, 3,3 ′, 5,5′-tetraisopropyl-4,4′-diaminobenzophenone, 3,3 ′, 5 5′-tetraethyl-4,4′-diaminodiphenyl ether, 3,3 ′, 5,5′-tetraisopropyl-4,4′-diaminodiphenyl And rusulfone and a combination of two or more of these.

  Aromatic polyamines having electron-withdrawing groups (for example, halogen atoms such as Cl, Br, I and F, alkoxy groups such as methoxy and ethoxy groups and nitro groups) include, for example, methylenebis-o-chloroaniline, 4 -Chloro-o-phenylenediamine, 2-chloro-1,4-phenylenediamine, 3-amino-4-chloroaniline, 4-bromo-1,3-phenylenediamine, 2,5-dichloro-1,4-phenylene Diamine, 5-nitro-1,3-phenylenediamine, 3-dimethoxy-4-aminoaniline; 4,4′-diamino-3,3′-dimethyl-5,5′-dibromo-diphenylmethane, 3,3′- Dichlorobenzidine, 3,3′-dimethoxybenzidine, bis (4-amino-3-chlorophenyl) oxide, (4-amino-2-chlorophenyl) propane, bis (4-amino-2-chlorophenyl) sulfone, bis (4-amino-3-methoxyphenyl) decane, bis (4-aminophenyl) sulfide, bis (4- Aminophenyl) telluride, bis (4-aminophenyl) selenide, bis (4-amino-3-methoxyphenyl) disulfide, 4,4′-methylenebis (2-iodoaniline), 4,4′-methylenebis (2-bromo) Aniline), 4,4′-methylenebis (2-fluoroaniline), 4-aminophenyl-2-chloroaniline and the like.

As the aromatic polyamine having a secondary amino group, for example, a part or all of —NH _{2 in} the above-described unsubstituted aromatic polyamine, aromatic polyamine having an alkyl group, and aromatic polyamine having an electron withdrawing group is —NH—. Substituted with R ′ (R ′ is an alkyl group, for example, a lower alkyl group having 1 to 4 carbon atoms such as a methyl group and an ethyl group) [for example, 4,4′-di (methylamino) diphenylmethane Or 1-methyl-2-methylamino-4-aminobenzene]; polyamide polyamine; dicarboxylic acid (for example, dimer acid) and excess (more than 2 moles per mole of acid) polyamines (for example, the above alkylene diamine or polyalkylene) Low molecular weight polyamide polyamines obtained by condensation with polyamines, etc .; Polyamines; hydrides of cyanoethylation products of polyether polyols (such as polyalkylene glycol, etc.).

  Examples of the polythiol (16) include alkanedithiols having 2 to 36 carbon atoms (for example, ethanedithiol, 1,4-butanedithiol, 1,6-hexanedithiol, etc.).

  Examples of the primary and / or secondary monoamine (17) include alkylamines having 2 to 24 carbon atoms (for example, ethylamine, n-butylamine, isobutylamine, diethylamine or n-butyl-n-dodecylamine). Is mentioned.

<Epoxy resin>
Examples of the epoxy resin include a ring-opening polymer of polyepoxide (18); polyepoxide (18) and an active hydrogen-containing compound [for example, water, diol (10), dicarboxylic acid (12), polyamine (15) or polythiol (16 And the like; and a cured product of polyepoxide (18) and an acid anhydride of dicarboxylic acid (12).

  The polyepoxide (18) is not particularly limited as long as it has two or more epoxy groups in the molecule. From the viewpoint of the mechanical properties of the cured product, preferred as the polyepoxide (18) is one having two epoxy groups in the molecule. The epoxy equivalent (molecular weight per epoxy group) of the polyepoxide (18) is preferably 65 to 1,000, and more preferably 90 to 500. When the epoxy equivalent is 1,000 or less, the crosslinked structure becomes dense, and physical properties such as water resistance, chemical resistance and mechanical strength of the cured product are improved. On the other hand, if the epoxy equivalent is less than 65, synthesis of the polyepoxide (18) may be difficult.

  Examples of the polyepoxide (18) include aromatic polyepoxy compounds and aliphatic polyepoxy compounds.

  Examples of aromatic polyepoxy compounds include glycidyl ethers of polyhydric phenols, glycidyl esters of aromatic polycarboxylic acids, glycidyl aromatic polyamines, and glycidylates of aminophenols.

  Examples of the polyglycol glycidyl ether include bisphenol F diglycidyl ether; bisphenol A diglycidyl ether; bisphenol B diglycidyl ether; bisphenol AD diglycidyl ether; bisphenol S diglycidyl ether; halogenated bisphenol A diglycidyl; Bisphenol A diglycidyl ether; catechin diglycidyl ether; resorcinol diglycidyl ether; hydroquinone diglycidyl ether; pyrogallol triglycidyl ether; 1,5-dihydroxynaphthalene diglycidyl ether; dihydroxybiphenyl diglycidyl ether; octachloro-4,4'-dihydroxy Biphenyl diglycidyl ether; tetramethylbiphenyl dig Dihydroxynaphthylcresol triglycidyl ether; tris (hydroxyphenyl) methane triglycidyl ether; dinaphthyltriol triglycidyl ether; tetrakis (4-hydroxyphenyl) ethanetetraglycidyl ether; p-glycidylphenyldimethyltolylbisphenol A glycidyl ether; Trismethyl-t-butyl-butylhydroxymethane triglycidyl ether; 9,9′-bis (4-hydroxyphenyl) furorange glycidyl ether; 4,4′-oxybis (1,4-phenylethyl) tetracresol glycidyl ether; 4,4′-oxybis (1,4-phenylethyl) phenylglycidyl ether, bis (dihydroxynaphthalene) tetraglycidyl ether Glycidyl ether of phenol or cresol novolac resin; glycidyl ether of limonene phenol novolak resin; diglycidyl ether obtained from the reaction of 2 mol of bisphenol A and 3 mol of epichlorohydrin; phenol and glyoxal, glutaraldehyde, or Examples include polyglycidyl ethers of polyphenols obtained by the condensation reaction of formaldehyde; polyglycidyl ethers of polyphenols obtained by the condensation reaction of resorcin and acetone.

  Examples of the glycidyl ester of aromatic polyvalent carboxylic acid include diglycidyl phthalate, diglycidyl isophthalate, and diglycidyl terephthalate.

  Examples of the glycidyl aromatic polyamine include N, N-diglycidylaniline, N, N, N ′, N′-tetraglycidylxylylenediamine and N, N, N ′, N′-tetraglycidyldiphenylmethanediamine. It is done.

  As the aromatic polyepoxy compound, in addition to the above-listed compounds, p-aminophenol triglycidyl ether (an example of a glycidylated product of aminophenol); diglycidyl obtained by reacting tolylene diisocyanate or diphenylmethane diisocyanate with glycidol Examples thereof include urethane compounds; glycidyl group-containing polyurethane (pre) polymers obtained by reacting tolylene diisocyanate or diphenylmethane diisocyanate, glycidol and polyol; diglycidyl ethers of AO adducts of bisphenol A, and the like.

  Examples of the aliphatic polyepoxy compound include a chain aliphatic polyepoxy compound and a cyclic aliphatic polyepoxy compound. The aliphatic polyepoxy compound may be a copolymer of diglycidyl ether and glycidyl (meth) acrylate.

  Examples of the chain aliphatic polyepoxy compounds include polyglycidyl ethers of polyhydric aliphatic alcohols, polyglycidyl esters of polyhydric fatty acids, and glycidyl aliphatic amines.

  Examples of polyglycidyl ethers of polyhydric aliphatic alcohols include ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tetramethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, polyethylene glycol diglycidyl ether, Polypropylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, trimethylolpropane polyglycidyl ether, glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, sorbitol polyglycidyl ether and polyglycerol polyglycidyl ether Is mentioned.

  Examples of the polyglycidyl ester of a polyvalent fatty acid include diglycidyl oxalate, diglycidyl malate, diglycidyl succinate, diglycidyl glutarate, diglycidyl adipate and diglycidyl pimelate.

  Examples of the glycidyl aliphatic amine include N, N, N ′, N′-tetraglycidylhexamethylenediamine.

  Examples of the cycloaliphatic polyepoxy compound include trisglycidyl melamine, vinylcyclohexene dioxide, limonene dioxide, dicyclopentadiene dioxide, bis (2,3-epoxycyclopentyl) ether, ethylene glycol bisepoxy dicyclopentyl ether, 3 , 4-Epoxy-6-methylcyclohexylmethyl-3 ′, 4′-epoxy-6′-methylcyclohexanecarboxylate, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, bis (3,4-epoxy -6-methylcyclohexylmethyl) butylamine and dimer acid diglycidyl ester. Moreover, as a cycloaliphatic polyepoxy compound, the hydrogenated thing of the said aromatic polyepoxy compound is also mentioned.

<Polyamide resin>
Examples of the polyamide resin include a ring-opening polymer of lactam, a polycondensate of aminocarboxylic acid, a polycondensate of polycarboxylic acid and polyamine, and the like.

<Polyimide resin>
Examples of the polyimide resin include aliphatic polyimide resins (for example, condensation polymers obtained from aliphatic carboxylic dianhydrides and aliphatic diamines), and aromatic polyimide resins (for example, aromatic carboxylic dianhydrides). And condensation polymers obtained from aliphatic diamines or aromatic diamines).

<Silicon resin>
Examples of the silicon resin include compounds having at least one of a silicon-silicon bond, a silicon-carbon bond, a siloxane bond, and a silicon-nitrogen bond in a molecular chain (for example, polysiloxane, polycarbosilane, or polysilazane). Etc.

<Phenolic resin>
Examples of the phenol resin include condensation polymers obtained from phenols (for example, phenol, cresol, nonylphenol, lignin, resorcin, or catechol) and aldehydes (for example, formaldehyde, acetaldehyde, or furfural).

<Melamine resin>
Examples of the melamine resin include a polycondensate obtained from melamine and formaldehyde.

<Urea resin>
Examples of urea resins include polycondensates obtained from urea and formaldehyde.

<Aniline resin>
Examples of aniline resins include those obtained by reacting aniline and aldehydes under acidic conditions.

<Ionomer resin>
Examples of the ionomer resin include a monomer having a polymerizable double bond (for example, an α-olefin monomer or a styrene monomer) and an α, β-unsaturated carboxylic acid (for example, acrylic acid, Methacrylic acid, maleic acid, itaconic acid, maleic acid monomethyl ester, maleic anhydride or maleic acid monoethyl ester, etc.) and a part or all of the carboxylic acid in the copolymer is a carboxylate (for example, , Potassium salt, sodium salt, magnesium salt or calcium salt).

<Polycarbonate resin>
Examples of the polycarbonate resin include condensation polymers of bisphenols (for example, bisphenol A, bisphenol F, or bisphenol S) and phosgene or carbonic acid diester.

<Crystalline / Amorphous>
The shell resin (a) may be a crystalline resin (a1), an amorphous resin (a2), or a crystalline resin (a1) and an amorphous resin (a2). It may be used in combination. From the viewpoint of fixability of the toner particles (C), the shell resin (a) is preferably a crystalline resin (a1).

  In this specification, “crystallinity” means the ratio (Tm / Ta) of the softening point of a resin (hereinafter abbreviated as “Tm”) and the maximum peak temperature of heat of fusion (hereinafter abbreviated as “Ta”) of the resin. ) Is 0.8 or more and 1.55 or less, and the result obtained by DSC does not show a stepwise endothermic change, but has a clear endothermic peak. In the present specification, “non-crystalline” means that the ratio of Tm to Ta (Tm / Ta) is larger than 1.55. Tm and Ta can be measured by the following method.

  Tm can be measured using a Koka type flow tester (for example, “CFT-500D” manufactured by Shimadzu Corporation). Specifically, while a 1 g measurement sample is heated at a heating rate of 6 ° C./min, a load of 1.96 MPa is applied to the measurement sample by a plunger, and the measurement sample is pushed out from a nozzle having a diameter of 1 mm and a length of 1 mm. . Then, the relationship between “plunger descent amount (flow value)” and “temperature” is drawn on a graph. The temperature at which the plunger descending amount is ½ of the maximum value of the descending amount is read from the graph, and this value (temperature when half of the measurement sample is pushed out of the nozzle) is defined as Tm.

  Ta can be measured using a differential scanning calorimeter (for example, “DSC210” manufactured by Seiko Instruments Inc.). Specifically, first, a sample used for measuring Ta is pretreated. After the sample is melted at 130 ° C., the temperature is lowered from 130 ° C. to 70 ° C. at a rate of 1.0 ° C./minute, and then the temperature is lowered from 70 ° C. to 10 ° C. at a rate of 0.5 ° C./minute. Next, the sample is heated at a heating rate of 20 ° C./min by DSC method to measure the endothermic change of the sample, and the relationship between the “endothermic amount” and “temperature” is plotted on a graph. At this time, the temperature of the endothermic peak observed at 20 to 100 ° C. is Ta ′. When there are a plurality of endothermic peaks, the temperature of the peak with the largest endothermic amount is defined as Ta '. Then, the sample is stored at (Ta′-10) ° C. for 6 hours, and then stored at (Ta′-15) ° C. for 6 hours.

  Next, by the DSC method, the sample subjected to the pretreatment was cooled to 0 ° C. at a temperature decrease rate of 10 ° C./min, and then the temperature was increased at a temperature increase rate of 20 ° C./min to measure the endothermic change. The relationship between the "heat absorption and heat generation" and "temperature" is plotted on a graph. The temperature at which the endotherm takes the maximum value is taken as the maximum peak temperature (Ta) of heat of fusion.

<Melting point>
Melting | fusing point of shell resin (a) becomes like this. Preferably it is 0-220 degreeC, More preferably, it is 30-200 degreeC, More preferably, it is 40-80 degreeC. From the viewpoint of the particle size distribution of the toner particles (C), the powder flowability of the liquid developer, the heat storage stability and the stress resistance, the melting point of the shell resin (a) is the temperature at which the liquid developer is produced. The above is preferable. If the melting point of the shell resin is lower than the temperature at which the liquid developer is produced, it may be difficult to prevent the toner particles from uniting with each other, and it may be difficult to prevent the toner particles from splitting. . In addition, the distribution width in the particle size distribution of the toner particles is difficult to be narrowed. In other words, there is a possibility that the variation in the particle size of the toner particles becomes large.

  In the present specification, the melting point is measured in accordance with a method prescribed in ASTM D3418-82 using a differential scanning calorimeter (such as “DSC20” or “SSC / 580” manufactured by Seiko Instruments Inc.). It is a thing.

<Mn and Mw>
The Mn of the shell resin (a) [obtained by measurement by gel permeation chromatography (hereinafter abbreviated as “GPC”)] is preferably 100 to 5000000, preferably 200 to 5000000, and more. Preferably it is 500-500000.

In the present specification, Mn and Mw of resins (excluding polyurethane resins) are those measured for the soluble content of tetrahydrofuran (hereinafter abbreviated as “THF”) using GPC under the following conditions. Equipment: “HLC-8120” manufactured by Tosoh Corporation
Column: “TSKgelGMHXL” (2) manufactured by Toyo Saw Corporation and “TSKgelMultiporeHXL-M” (1) manufactured by Toyo Saw Corporation
Sample solution: 0.25 mass% THF solution Injection amount of sample solution to the column: 100 μl
Flow rate: 1 ml / min Measurement temperature: 40 ° C
Detection device: Refractive index detector Reference material: 12 standard polystyrene (TSK standard POLYSTYRENE) manufactured by Tosoh Corporation (molecular weight: 500, 1050, 2800, 5970, 9100, 18100, 37900, 96400, 190000, 355000, 1090000, 2890000).

In this specification, Mn and Mw of the polyurethane resin are measured under the following conditions using GPC. Measuring apparatus: “HLC-8220GPC” manufactured by Tosoh Corporation
Column: “Guardcolum α” (1) and “TSKgel α-M” (1)
Sample solution: 0.125% by mass dimethylformamide solution Injection amount of sample solution to the column: 100 μl
Flow rate: 1 ml / min Measurement temperature: 40 ° C
Detection device: Refractive index detector Reference material: 12 standard polystyrene (TSK standard POLYSTYRENE) manufactured by Tosoh Corporation (molecular weight: 500, 1050, 2800, 5970, 9100, 18100, 37900, 96400, 190000, 355000, 1090000, 2890000).

<SP value>
The SP value of the shell resin (a) is preferably 7 to 18 (cal / cm ³ ) ^1/2 , more preferably 8 to 14 (cal / cm ³ ) ^1/2 .

  Although the shell resin (a) has been described above, when manufacturing the liquid developer, the shell particles (A) made of the shell resin (a) are dispersed in the insulating liquid (L). Therefore, from the viewpoint of preventing the shell particles (A) from being dissolved or swollen with respect to the insulating liquid (L), Mn, Mw, SP value, crystallinity, molecular weight between crosslinking points, etc. of the shell resin (a) Is preferably adjusted as appropriate.

  Further, the shell particles (A) made of the shell resin (a) have a strength that is not broken by shear at the temperature when dispersed in the insulating liquid (L), and are dissolved in the insulating liquid (L). Or it is preferable that it has characteristics, such as being hard to swell and being hard to melt | dissolve in the solution in which the core resin (b) or the precursor (b0) of the core resin (b) was melt | dissolved. It is preferable to determine the material and physical properties of the shell resin (a) so that the shell particles (A) have this characteristic.

<Core resin (b)>
As the core resin (b) in the present embodiment, any known resin can be used. Specific examples of the core resin (b) are listed as specific examples of the shell resin (a). The thing similar to a thing is mentioned. Of those exemplified as specific examples of the shell resin (a), the core resin (b) is preferably a polyester resin, a polyurethane resin, an epoxy resin, a vinyl resin, or a combination thereof. More preferably, the material of the shell resin (a) and the material of the core resin (b) are selected so that the core resin (b) melts at a temperature lower than that of the shell resin (a).

The core resin (b) preferably has a heat of fusion by DSC of the core resin (b) satisfying the following formulas (1) to (1): 5 ≦ H1 ≦ 70 1)
0.2 ≦ H2 / H1 ≦ 1.0 (2)
In the above formulas (1) to (2), H1 represents the heat of fusion (J / g) at the first temperature rise by DSC, and H2 represents the heat of fusion (J / g) at the second temperature rise by DSC. .

  H1 is an index of the melting rate of the core resin (b). In general, a resin having heat of fusion has a sharp melt property and can be melted with a small amount of energy. Therefore, if a resin having heat of fusion is selected as the core resin (b), the energy required for fixing can be reduced. Therefore, it is preferable to select a resin having heat of fusion as the core resin (b). However, if the heat of fusion of the resin is too large, it may be difficult to sufficiently melt the resin. Preferably 6 ≦ H1 ≦ 65, and more preferably 7 ≦ H1 ≦ 65.

  H2 / H1 in the formula (2) is an index of the crystallization rate of the core resin (b). In general, when a resin particle (resin particle) is used after being cooled and then cooled, if there is a non-crystallized portion in the crystal component in the resin particle, the resistance value of the resin particle is There arises a problem that the resin particles are lowered or the resin particles are plasticized. When such a malfunction occurs, the performance of the resin particles obtained by cooling may differ from the originally designed performance. From the above, it is necessary to quickly crystallize the crystal component in the resin particles so as not to affect the performance of the resin particles. H2 / H1 is more preferably 0.3 or more, and further preferably 0.4 or more. Further, if the crystallization speed of the core resin (b) is high, H2 / H1 approaches 1.0, and therefore H2 / H1 preferably takes a value close to 1.0.

  Note that H2 / H1 in the above formula (2) does not theoretically exceed 1.0, but it may exceed 1.0 in the actual measurement value by DSC. Even when the actual measurement value (H2 / H1) by DSC exceeds 1.0, the above equation (2) is satisfied.

  H1 and H2 can be measured according to JIS-K7122 (1987) “Method for measuring the transition heat of plastic”. Specifically, first, 5 mg of the core resin (b) is collected and placed in an aluminum pan. Using a differential scanning calorimeter (for example, “RDC220” manufactured by SII Nano Technology Co., Ltd. or “DSC20” manufactured by Seiko Instruments Inc.) and the like, the heating rate is set to 10 ° C. per minute, and the core is melted. The temperature (melting point) at the endothermic peak of the resin (b) is measured to determine the endothermic peak area S1. And H1 is computable from the area | region S1 of the calculated | required endothermic peak. After calculating H1, after cooling to 0 ° C. with a cooling rate of 90 ° C./min, the temperature (melting point) at the endothermic peak of the core resin (b) due to melting was measured at a rate of temperature increase of 10 ° C. per minute. The area S2 of the endothermic peak is obtained. And H2 is computable from the area | region S2 of the calculated | required endothermic peak.

  By appropriately selecting the constituent components of the core resin (b), the above formulas (1) to (2) can be satisfied. From the viewpoint of improving the verification property, as the constituent component of the core resin (b), for example, a monomer having a linear alkyl skeleton having 4 or more carbon atoms is preferable. Preferable examples of the monomer constituting the core resin (b) include aliphatic dicarboxylic acids and aliphatic diols.

  Preferred examples of the aliphatic dicarboxylic acid include alkane dicarboxylic acids having 4 to 20 carbon atoms; alkane dicarboxylic acids having 4 to 36 carbon atoms; and ester-forming derivatives thereof. More preferred as the aliphatic dicarboxylic acid are succinic acid, adipic acid, sebacic acid, maleic acid, fumaric acid and the like, or ester-forming derivatives thereof.

  Preferred as the aliphatic diol is ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,9-nonanediol, or 1,10-decanediol.

<Mn, melting point, Tg and SP value>
The Mn, melting point, Tg, and SP value of the core resin (b) may be appropriately adjusted within a preferable range depending on the application.

For example, when the liquid developer according to this embodiment is used as a liquid developer used for electrophotography, electrostatic recording, electrostatic printing, or the like, the Mn, melting point, Tg, and SP value of the core resin (b) are It is preferable to take the following values. Mn of core resin (b) becomes like this. Preferably it is 1000-5 million, More preferably, it is 2000-500000. The melting point of the core resin (b) is preferably 20 to 300 ° C, more preferably 80 to 250 ° C. Tg of core resin (b) becomes like this. Preferably it is 20-200 degreeC, More preferably, it is 40-150 degreeC. The SP value of the core resin (b) is preferably 8 to 16 (cal / cm ³ ) ^1/2 , more preferably 9 to 14 (cal / cm ³ ) ^1/2 . Mn can be measured according to the method described in <Mn and Mw> above. The melting point can be measured according to the method described in the above <melting point>. Tg can be measured according to the method described in [Configuration of Liquid Developer] above.

<Toner particles>
The toner particles according to the present embodiment have a core-shell structure, and the shell particles (A) containing the shell resin (a) are attached to the surface of the core particles (B) containing the core resin (b). The shell particles (A) may be coated on the surfaces of the core particles (B).

  The particle diameter of the shell particles (A) is preferably smaller than the particle diameter of the core particles (B). From the viewpoint of uniformity of particle size of the toner particles (C), the particle size ratio [(volume average particle size of shell particles (A)) / (volume average particle size of core particles (B)]] is 0.001 to 0. Is preferably within the range of .3. More preferably, the lower limit of the particle size ratio is 0.003 and the upper limit is 0.25. When the particle size ratio is larger than 0.3, the shell particles (A) are difficult to be efficiently adsorbed on the surface of the core particles (B), and thus the distribution range in the particle size distribution of the obtained toner particles (C) is widened. Tend. On the other hand, when the particle size ratio is smaller than 0.001, it may be difficult to produce the shell particles (A).

  The volume average particle size of the shell particles (A) is set to a particle size suitable for obtaining toner particles (C) having a desired particle size, and the particle size ratio is within the preferable range. Can be adjusted as appropriate. The volume average particle diameter of the shell particles (A) is preferably 0.0005 to 30 μm. The upper limit of the volume average particle diameter of the shell particles (A) is more preferably 20 μm, and even more preferably 10 μm. The lower limit of the volume average particle diameter of the shell particles (A) is more preferably 0.01 μm, still more preferably 0.02 μm, and most preferably 0.04 μm. For example, when it is desired to obtain toner particles (C) having a volume average particle diameter of 1 μm, the volume average particle diameter of the shell particles (A) is preferably 0.0005 to 0.3 μm, more preferably 0.001. ~ 0.2 μm. For example, when it is desired to obtain toner particles (C) having a volume average particle size of 10 μm, the volume average particle size of the shell particles (A) is preferably 0.005 to 3 μm, more preferably 0.05 to 2 μm. It is. For example, when it is desired to obtain toner particles (C) having a volume average particle size of 100 μm, the volume average particle size of the shell particles (A) is preferably 0.05 to 30 μm, more preferably 0.1 to 20 μm. It is.

  From the viewpoint of easily controlling the particle size ratio within the above preferred range, the volume average particle size of the core particles (B) is preferably 0.1 to 300 μm, more preferably 0.5 to 250 μm, More preferably, it is 1-200 micrometers.

  In the present specification, the “volume average particle size” is a laser particle size distribution measuring device (for example, “LA-920” manufactured by Horiba, Ltd. or “Multisizer III” manufactured by Coulter, Inc.); laser Doppler as an optical system “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.) using a method; a flow type particle image analyzer (for example, “FPIA-3000S” manufactured by Sysmex Corporation) can be used. When the volume average particle diameter is measured with a different measuring apparatus, if a difference occurs in the measured value, the measured value by “ELS-800” is adopted.

  The mass ratio [(A) :( B)] of the shell particles (A) and the core particles (B) is preferably 1:99 to 70:30. From the viewpoint of the particle size uniformity of the toner particles (C) and the heat resistance stability of the liquid developer, the ratio [(A) :( B)] is more preferably 2:98 to 50:50, Preferably it is 3: 97-35: 65. If the content (mass ratio) of the shell particles is too low, the blocking resistance of the toner particles may be lowered. If the content (mass ratio) of the shell particles is too high, the particle size uniformity of the toner particles may decrease.

  The shape of the toner particles (C) is preferably spherical from the viewpoint of fluidity of the liquid developer and its melt leveling property. Specifically, the average value (average circularity) of the circularity of the toner particles (C) is preferably 0.92 to 1.0, more preferably 0.97 to 1.0, and still more preferably. Is 0.98 to 1.0. If the core particles (B) are spherical, the toner particles (C) are likely to be spherical. Therefore, the core particles (B) are preferably spherical.

  In this specification, the average circularity is the circumference of a toner particle (C) in which the circumference of a circle having an area equal to the projected area of the toner particle (C) is detected optically. The value divided by the length. Specifically, the average circularity is measured using a flow type particle image analyzer (for example, “FPIA-3000S” manufactured by Sysmex Corporation). Specifically, 100 to 150 ml of water from which impure solids have been removed in advance is placed in a predetermined container, and a surfactant (for example, “Dry Well” manufactured by Fuji Photo Film Co., Ltd.) 0.1 to 0. 5 ml is added, and about 0.1 to 9.5 g of a measurement sample is further added. The suspension in which the measurement sample is dispersed in this manner is subjected to a dispersion treatment for about 1 to 3 minutes using an ultrasonic disperser (for example, “Ultrasonic Cleaner Model VS-150” manufactured by Wellboclear). To do. Thus, the dispersion concentration is set to 3,000 to 10,000 / μL. And the shape and particle size distribution of a measurement sample are measured using the sample solution after a dispersion process.

  The volume average particle size of the toner particles (C) is preferably determined as appropriate depending on the application, but is generally preferably 0.01 to 100 μm. The upper limit of the volume average particle diameter of the toner particles (C) is more preferably 40 μm, still more preferably 30 μm, and most preferably 20 μm. The lower limit of the volume average particle diameter of the toner particles (C) is more preferably 0.3 μm, and further preferably 0.5 μm.

  From the viewpoint of uniformity of the particle size of the toner particles (C), the coefficient of variation of the volume distribution of the toner particles (C) is preferably 1 to 100%, more preferably 1 to 50%, and still more preferably 1. -30%, most preferably 1-25%. In this specification, the coefficient of variation of the volume distribution is measured using a particle size distribution measuring device such as a laser particle size distribution measuring device (for example, “LA-920” manufactured by Horiba, Ltd.).

From the viewpoints of particle size uniformity of the toner particles (C), fluidity of the liquid developer, and heat stability of the liquid developer, the surface coverage of the core particles (B) by the shell particles (A) in the toner particles (C) Is preferably 50% or more, more preferably 80% or more. The surface coating means that the shell particles (A) are attached or coated on the surfaces of the core particles (B). Moreover, the surface coverage of the core particle (B) by the shell particle (A) can be obtained based on the following mathematical formula (3) from image analysis of an image obtained with a scanning electron microscope (SEM), for example. The shape of the toner particles (C) can be controlled by changing the surface coverage determined by the following formula (3). Surface coverage (%) = core particles covered with shell particles (A) Area of (B) / [(Area of core particle (B) covered with shell particle (A) + Area of core particle (B) exposed from shell particle (A))] × 100. -Formula (3).

  The surface average center line roughness (Ra) of the toner particles (C) is preferably 0.01 to 0.8 μm from the viewpoint of the fluidity of the liquid developer. The surface average centerline roughness (Ra) is a value obtained by arithmetically averaging the absolute value of the deviation between the roughness curve and the centerline of the roughness curve, and is a scanning probe microscope system (for example, Toyo Technica ( Etc.).

  From the viewpoint of the particle size distribution of the toner particles (C) and the heat stability of the liquid developer, the core / shell structure of the toner particles (C) is 1 to 70% by mass (more than the mass of the toner particles (C)). Preferably, the film-like shell particles (A) of 5 to 50% by mass, more preferably 10 to 35% by mass, and 30 to 99% by mass (more preferably 50 to 95% by mass, still more preferably 65 to 90% by mass). %) Core particles (B).

  From the viewpoint of the fixability of the toner particles (C) and the heat stability of the liquid developer, the content of the toner particles (C) in the liquid developer is preferably 10 to 50% by mass, more preferably 15 to It is 45 mass%, More preferably, it is 20-40 mass%.

<Additives>
The toner particles (C) in the present embodiment preferably contain a colorant in at least one of the shell particles (A) and the core particles (B), and additives other than the colorant (for example, fillers, An antistatic agent, a release agent, a charge control agent, an ultraviolet absorber, an antioxidant, an antiblocking agent, a heat stabilizer, a flame retardant, and the like.

<Colorant>
As the colorant, known pigments can be used without any particular limitation, but the following colorants are preferably used from the viewpoints of cost, light resistance and colorability. In terms of color composition, the colorants shown below are usually classified into black pigments, yellow pigments, magenta pigments, and cyan pigments. Colors other than black (color images) are basically yellow pigments, magenta pigments, and cyan pigments. It is toned by subtractive color mixing. Further, as the colorant, those obtained by subjecting the following pigments to surface treatment using an acidic or basic solvent may be used. For example, acidic or basic synergists may be added to the following pigments: You may use together.

Examples of the black pigment include carbon black.
Examples of yellow pigments include disazo yellow pigments such as CI (Color Index) Pigment Yellow 12, 13, 14, 17, 55, 81, 83, 180, and 185.

  Examples of the magenta pigment include azo lake type magenta pigments such as CIPigment Red 48, 57 (Kermin 6B), 5, 23, 60, 114, 146 and 186; insoluble azo magenta pigments; CIPigment Examples include thioindigo magenta pigments such as Red 88 and CIPigment Violet 36 and 38; quinacridone magenta pigments such as CIPigment Red 122 and 209; naphthol magenta pigments such as CIPigment Red 269 and the like. The magenta pigment preferably contains at least one of quinacridone pigments, carmine pigments and naphthol pigments, more preferably two or three of these three pigments. It is included.

  Examples of cyan pigments include copper phthalocyanine blue cyan pigments such as C.I. Pigment Blue 15: 1 and 15: 3; and phthalocyanine green pigments.

<Wax>
From the standpoint of heat resistance stability of the liquid developer, modified wax (d) obtained by graft polymerization of wax (c) and a monomer having a polymerizable double bond onto wax (c) as an additive (hereinafter referred to as “ It is preferable that at least one of the modified wax (abbreviated as “d”) is contained in the core particle (B) (core layer).

  The content of the wax (c) is preferably 20% by mass or less, more preferably 1 to 15% by mass with respect to the mass of the core particles (B). The content of the modified wax (d) is preferably 10% by mass or less, more preferably 0.5 to 8% by mass with respect to the mass of the core particles (B). The total content of the wax (c) and the modified wax (d) is preferably 25% by mass or less, more preferably 1 to 20% by mass with respect to the mass of the core particles (B).

  Examples of the wax (c) include synthetic wax (eg, polyolefin wax); natural wax (eg, paraffin wax, microcrystalline wax, carnauba wax, carbonyl group-containing wax, or a combination thereof). Of these, paraffin wax and carnauba wax are preferred as the wax (c). Examples of the paraffin wax include petroleum wax mainly composed of linear saturated hydrocarbon having a melting point of 50 to 90 ° C. and a carbon number of 20 to 36. Examples of carnauba wax include animal and plant waxes having a melting point of 50 to 90 ° C. and a carbon number of 16 to 36.

  The Mn of the wax (c) is preferably 400 to 5000, more preferably 1000 to 3000, and further preferably 1500 to 2000 from the viewpoint of releasability. In this specification, Mn of wax (c) is measured using GPC. For the measurement of Mn of the wax (c), for example, o-dichlorobenzene can be used as the solvent, and for example, polystyrene can be used as the reference substance.

  When the wax (c) and the modified wax (d) are used in combination, the wax (c), together with the modified wax (d), is a melt-kneading process in the absence of a solvent and a heat-dissolving mixing process in the presence of an organic solvent. It is preferable to disperse in the core resin (b) after at least one of the treatments. In this way, by allowing the modified wax (d) to coexist during the wax dispersion treatment, the wax base portion of the modified wax (d) is efficiently adsorbed on the surface of the wax (c), or the wax of the modified wax (d). Part of the base portion is efficiently entangled with the matrix structure of the wax (c). Thereby, the affinity between the surface of the wax (c) and the core resin (b) is improved, and the wax (c) can be more uniformly encapsulated in the core particles (B). Therefore, it becomes easy to control the dispersion state of the wax (c).

  The modified wax (d) is obtained by graft polymerization of a monomer having a polymerizable double bond onto the wax (c). Examples of the wax used in the modified wax (d) include the same as those listed as specific examples of the wax (c). Preferred wax materials used in the modified wax (d) are also the above waxes. The thing similar to what was enumerated as a preferable material of (c) is mentioned. Examples of the monomer having a polymerizable double bond include those similar to the monomers (1) to (9) having a polymerizable double bond constituting the above vinyl resin. Of these, the monomer (1), the monomer (2) and the monomer (6) are preferred. As the monomer having a polymerizable double bond, any one of the monomers (1) to (9) may be used alone, or two or more kinds may be used in combination.

  The amount of the wax component (including unreacted wax) in the modified wax (d) is preferably 0.5 to 99.5% by mass, more preferably 1 to 80% by mass, and further preferably 5 to 50%. It is 10 mass%, Most preferably, it is 10-30 mass%.

  From the viewpoint of heat-resistant storage stability of the liquid developer, the Tg of the modified wax (d) is preferably 40 to 90 ° C, more preferably 50 to 80 ° C.

  The Mn of the modified wax (d) is preferably 1500 to 10,000, more preferably 1800 to 9000. When the Mn of the modified wax (d) is 1500 to 10,000, the toner particles (C) have good mechanical strength.

  The method for producing such a modified wax (d) is not particularly limited. For example, the wax (c) is dissolved or dispersed in a solvent (for example, toluene or xylene) and heated to 100 to 200 ° C., and then the monomer having a polymerizable double bond is polymerized and then the solvent is distilled off. As a result, the modified wax (d) can be obtained.

Examples of the method of mixing the wax (c) and the modified wax (d) include the methods described in [i] to [iii] below. Of the following [i] to [iii], the following [ii] is preferably used. [I]: The wax (c) and the modified wax (d) are melted and kneaded at a temperature equal to or higher than the respective melting points [ii]. : Wax (c) and modified wax (d) are dissolved or suspended in the organic solvent (u) described later, and then precipitated in the liquid by cooling crystallization or solvent crystallization, or spray drying, etc. [Iii]: After dissolving or suspending the wax (c) and the modified wax (d) in the organic solvent (u) described later, mechanically wet using a disperser or the like Grind.

  Examples of the method for dispersing the wax (c) and the modified wax (d) in the core resin (b) include dissolving the wax (c) and the modified wax (d) and the core resin (b) in a solvent, respectively. The method of mixing these after dispersing is mentioned.

<Insulating liquid>
Examples of the insulating liquid (L) include hexane, octane, isooctane, decane, isodecane, decalin, nonane, dodecane, isododecane, cyclohexane, cyclooctane, cyclodecane, benzene, toluene, xylene, mesitylene, Isopar E, Isopar G, Isopar H, Isopar L (isopar: trade name of Exxon), Shellsol 70, Shellsol 71 (shellsol: trade name of Shell Oil), Amsco OMS, Amsco 460 (Amsco: trade name of Spirits), IP Solvent 2028 (trade name of Idemitsu Kosan), silicone oil, liquid paraffin and the like can be mentioned. These may be used alone or in combination of two or more.

  Of these, from the viewpoint of odor, the insulating liquid (L) is preferably a solvent having a boiling point of 100 ° C. or higher, and more preferably a hydrocarbon solvent having 10 or more carbon atoms (for example, dodecane, isododecane). And liquid oil paraffin) and silicone oil, and liquid paraffin is more preferable.

  The solvent contained in the liquid developer according to the present embodiment is preferably substantially only the insulating liquid (L), but the liquid developer is preferably 1% by mass or less, more preferably 0.8%. Other organic solvents may be contained within a range of 5% by mass or less.

<Method for producing liquid developer>
The method for producing the liquid developer according to the present embodiment is not particularly limited. For example, a dispersion liquid (shell particles) in which shell particles (A) containing a shell resin (a) are dispersed in an insulating liquid (L). A step of preparing a dispersion (W) of (A), and a step of preparing a solution (core resin (b) forming solution (Y)) in which the core resin (b) is dissolved in an organic solvent (M). And a step of preparing a dispersion in which the colorant is dispersed (colorant dispersion), and a dispersion (W) of the shell particles (A) and a solution (Y) for forming the core resin (b) are mixed. To obtain a dispersion (X ′) of the third resin particles (C ′), and after distilling off the organic solvent (M) from the dispersion (X ′) of the third resin particles (C ′), alcohol And obtaining the toner particles (C). Hereinafter, it shows for every process.

<Preparation of dispersion (W) of shell particles (A)>
In the step of preparing the dispersion liquid (W) of the shell particles (A), the shell particles (A) may be produced and then dispersed in the insulating liquid (L). In (L), the shell particles (A) may be produced by a polymerization reaction or the like. Here, as shell resin (a) contained in shell particle | grains (A), resin mentioned by said <shell resin (a)> can be used.

In the case where the shell particles (A) are dispersed in the insulating liquid (L) after the shell particles (A) are produced, it is preferable to use any one of the following methods [4] to [6]. It is more preferable to use [6]. Moreover, when manufacturing the shell particles (A) by a polymerization reaction or the like in the insulating liquid (L), it is preferable to use any one of the following methods [1] to [3]. [1]: When the shell resin (a) is a vinyl resin. The monomer is polymerized by a dispersion polymerization method or the like in a solvent containing the insulating liquid (L). Thereby, the dispersion liquid (W1) of the shell particles (A) is directly produced. If necessary, a solvent other than the insulating liquid (L) is distilled off from the dispersion liquid (W) of the shell particles (A). When the solvent other than the insulating liquid (L) is distilled off, the low boiling point component of the insulating liquid (L) may be distilled off. This is the same in the step of distilling off the solvent other than the insulating liquid (L) shown below. [2]: The shell resin (a) is a polyaddition resin such as a polyester resin or a polyurethane resin or a condensation resin. If there is. If necessary, a precursor (monomer or oligomer) or a precursor solution is dispersed in the insulating liquid (L) in the presence of an appropriate dispersant, and then the precursor is heated or added with a curing agent. Is cured. If necessary, the solvent other than the insulating liquid (L) is distilled away. [3]: The shell resin (a) is a polyaddition resin such as a polyester resin or a polyurethane resin or a condensation resin. After dissolving an appropriate emulsifier in a precursor (such as a monomer or oligomer) or a solution of the precursor (the starting material is preferably a liquid but may be liquefied by heating) Then, an insulating liquid (L) serving as a poor solvent is added to reprecipitate the precursor. Then, the precursor is cured by adding a curing agent, and the solvent other than the insulating liquid (L) is distilled off as necessary. [4]: Polymerization reaction (addition polymerization, ring-opening polymerization, polyaddition, addition) in advance Any polymerization reaction such as condensation and condensation polymerization may be used.The same applies to [5] and [6] below.) The shell resin (a) obtained by the mechanical rotation type or jet type fine pulverizer is used. And then classified. Thereby, shell particle | grains (A) are obtained. Disperse the obtained shell particles (A) in the insulating liquid (L) in the presence of a suitable dispersant [5]: Resin solution in which the shell resin (a) obtained by the polymerization reaction in advance is dissolved (this The resin solution may be sprayed in the form of a mist, which may be obtained by polymerizing the shell resin (a) in a solvent. Thereby, shell particle | grains (A) are obtained. The obtained shell particles (A) are dispersed in the insulating liquid (L) in the presence of an appropriate dispersant. [6]: Resin solution in which the shell resin (a) obtained by the polymerization reaction is dissolved (this solution The resin solution may be a poor solvent (preferably an insulating liquid (L)) added to the shell resin (a) obtained by polymerizing the shell resin (a) in a solvent, or The shell particles (A) are precipitated by cooling the resin solution obtained by preliminarily dissolving the shell resin (a) by heating, and further by adding an appropriate dispersant. If necessary, a solvent other than the insulating liquid (L) is distilled off.

When manufacturing the shell particles (A) and then dispersing the shell particles (A) in the insulating liquid (L), the manufacturing method of the shell particles (A) is not particularly limited, and is a dry process shown in [7] below. A method of manufacturing the shell particles (A) may be used, or a method of manufacturing the shell particles (A) by a wet method represented by the following [8] to [13] may be used. From the viewpoint of easy manufacture of the shell particles (A), the manufacturing method of the shell particles (A) is preferably wet, more preferably [10], [12] or [13] below. More preferably, it is the following [12] or [13] [7]: Using a known dry pulverizer such as a jet mill, the shell resin (a) is pulverized dry [8]: of the shell resin (a) The powder is dispersed in an organic solvent and pulverized by a wet method using a known wet disperser such as a bead mill or a roll mill. [9] The solution of the shell resin (a) is sprayed and dried using a spray dryer or the like. 10]: Addition of a poor solvent or cooling to the solution of the shell resin (a) to supersaturate the shell resin (a) to precipitate [11]: Water or an organic solvent for the solution of the shell resin (a) [12]: The shell resin (a) precursor is polymerized in water by emulsion polymerization, soap-free emulsion polymerization, seed polymerization, suspension polymerization, or the like. [13]: Shell resin (a ) Is polymerized by dispersion polymerization or the like in an organic solvent.

  Examples of the dispersant in [2] and [4] to [6] include a known surfactant (s) and an oil-soluble polymer (t). Further, as a dispersion aid, for example, an organic solvent (u) and a plasticizer (v) can be used in combination.

  Examples of the surfactant (s) include an anionic surfactant (s-1), a cationic surfactant (s-2), an amphoteric surfactant (s-3), and a nonionic surfactant ( s-4). In addition, you may use 2 or more types of surfactant together as surfactant (s).

  Examples of the anionic surfactant (s-1) include ether carboxylic acid (salt) having an alkyl group having 8 to 24 carbon atoms [for example, (poly) oxyethylene (having 1 to 100 repeating units) lauryl ether. Sodium acetate etc.]; ether sulfate ester salt having an alkyl group having 8 to 24 carbon atoms [for example, (poly) oxyethylene (having 1 to 100 repeating units) sodium lauryl sulfate etc.]; alkyl having 8 to 24 carbon atoms Sulfosuccinic acid ester salts having a group [e.g. sodium mono or dialkyl sulfosuccinic acid ester, monosodium mono or dialkyl sulfosuccinic acid ester, (poly) oxyethylene (with 1-100 repeat units) mono sodium or dialkyl sulfosuccinic acid ester, or , (Po ) Oxyethylene (with 1-100 repeat units) mono or dialkyl sulfosuccinate disodium etc.]; (poly) oxyethylene (1-100 repeat units) coconut oil fatty acid sodium monoethanolamide sulfate; 8 carbon atoms Sulfonate having an alkyl group of ˜24 (for example, sodium dodecylbenzene sulfonate); phosphate ester salt having an alkyl group having 8 to 24 carbon atoms [for example, sodium lauryl phosphate or (poly) oxyethylene (The number of repeating units is 1 to 100) sodium lauryl ether phosphate, etc .; fatty acid salts (for example, sodium laurate or triethanolamine laurate); acylated amino acid salts (for example, palm oil fatty acid methyl taurine sodium), etc. All It is.

  Examples of the cationic surfactant (s-2) include quaternary ammonium salt type cationic surfactants and amine salt type cationic surfactants. Examples of quaternary ammonium salt type cationic surfactants include tertiary amines and quaternizing agents (eg, alkyl halides such as methyl chloride, methyl bromide, ethyl chloride, and benzyl chloride, dimethyl sulfate, dimethyl carbonate, Or the compound etc. which are obtained by reaction with ethylene oxide etc. are mentioned. Specific examples of the quaternary ammonium salt type cationic surfactant include didecyldimethylammonium chloride, stearyltrimethylammonium bromide, lauryldimethylbenzylammonium chloride (benzalkonium chloride), polyoxyethylenetrimethylammonium chloride and stearamide. Examples thereof include ethyl diethylmethylammonium methosulfate.

  Examples of amine salt type cationic surfactants include primary to tertiary amines such as inorganic acids (for example, hydrochloric acid, nitric acid, sulfuric acid or hydroiodic acid) or organic acids (for example, acetic acid, formic acid, oxalic acid, And compounds obtained by neutralization with lactic acid, gluconic acid, adipic acid or alkyl phosphoric acid). Examples of the primary amine salt type cationic surfactant include inorganic acid salts or organic acid salts of aliphatic higher amines (for example, higher amines such as laurylamine, stearylamine, hardened tallow amine or rosinamine); lower amines Higher fatty acid (for example, stearic acid or oleic acid) salts and the like. Examples of secondary amine salt type cationic surfactants include inorganic acid salts of aliphatic amines such as ethylene oxide adducts of aliphatic amines or organic acid salts thereof.

  Examples of the amphoteric surfactant (s-3) include carboxybetaine-type amphoteric surfactants [for example, fatty acid amidopropyldimethylaminoacetic acid betaines having 10 to 18 carbon atoms (such as coconut oil fatty acid amidopropyl betaine), alkyls, etc. (C10-C18) dimethylaminoacetic acid betaine (such as lauryldimethylaminoacetic acid betaine) or imidazolinium-type carboxybetaine (such as 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine) And the like]; sulfobetaine-type amphoteric surfactants [for example, fatty acid amidopropylhydroxyethylsulfobetaine having 10 to 18 carbon atoms (for example, coconut oil fatty acid amidopropyldimethylhydroxyethylsulfobetaine), or Methyl alkyl (carbon number 10 to 18) such as dimethyl hydroxyethyl sulfobetaine (such as lauryl hydroxy sulfobetaine)]; amino acid type amphoteric surfactants (e.g. β- lauryl aminopropionic acid sodium, etc.) and the like.

  Examples of the nonionic surfactant (s-4) include AO addition type nonionic surfactants and polyhydric alcohol type nonionic surfactants.

  As the AO addition type nonionic surfactant, for example, AO (having 2 to 4 carbon atoms, preferably 2) adduct of higher alcohol (8 to 18 carbon atoms) (addition moles per active hydrogen) 1-30); alkyl (carbon number 1-12) phenol EO adduct (addition mole number 1-30); higher amine (carbon number 8-22) AO (carbon number 2-4, preferably 2) Adduct (1-40 added moles per active hydrogen); EO adduct of fatty acids (8-18 carbon atoms) (1-60 added moles per active hydrogen); Polypropylene Glycol (Mn = 200 to 4000) EO adduct (1 to 50 moles added per active hydrogen); polyoxyethylene (3 to 30 repeat units) alkyl (6 to 20 carbon atoms) allyl ether Sorbitan monolaure Too EO adduct (1-30 mol added per active hydrogen) and sorbitan monooleate EO adduct (1-30 added mol per active hydrogen) (2-8 valences) Or higher valence) fatty acid (carbon number 8-24) ester EO adduct (number of added moles per active hydrogen 1-30) of alcohol (carbon number 2-30).

  Examples of the polyhydric alcohol type nonionic surfactant include polyvalent (2 to 8 or more valent) alcohols (having 2 to 8 carbon atoms) such as glycerin monooleate, sorbitan monolaurate and sorbitan monooleate. 30) fatty acid (having 8 to 24 carbon atoms) esters; fatty acid (having 10 to 18 carbon atoms) alkanolamides such as lauric acid monoethanolamide and lauric acid diethanolamide.

  Examples of the oil-soluble polymer (t) include a polymer having at least one of an alkyl group having 4 or more carbon atoms, a dimethylsiloxane group, and a functional group having a fluorine atom. More preferably, the oil-soluble polymer (t) has at least one group of an alkyl group having affinity for the insulating liquid (L), a dimethylsiloxane group, and a functional group having a fluorine atom, and the core resin (b). It has a chemical structure that has an affinity for.

  The oil-soluble polymer (t) is a monomer having a dimethylsiloxane group, a monomer having an alkyl group having 4 or more carbon atoms, among the monomers (1) to (9) having a polymerizable double bond. More preferably, the polymer (or reactive oligomer) and at least one monomer having a fluorine atom are polymerized or copolymerized.

  The organic solvent (u) may be an insulating liquid (L) or an organic solvent other than the insulating liquid (L) (for example, an organic solvent (M) described later other than the insulating liquid (L)). Or other solvents). Since the solvent other than the insulating liquid (L) is distilled off after the preparation of the dispersion liquid (W) of the shell particles (A), it is preferable that the solvent is easily distilled off, for example, the insulating liquid (L It is preferable that the boiling point is lower than.

  The plasticizer (v) may be added to the insulating liquid (L) as necessary when dispersing the shell particles (A), or may be added to a solvent containing the core resin (b) and the like. .

  It does not specifically limit as a plasticizer (v), What is shown to the following plasticizers (v1)-(v6) is mentioned.

  Examples of the plasticizer (v1) include phthalate esters (for example, dibutyl phthalate, dioctyl phthalate, butyl benzyl phthalate, diisodecyl phthalate, and the like).

  Examples of the plasticizer (v2) include aliphatic dibasic acid esters (for example, di-2-ethylhexyl adipate or 2-ethylhexyl sebacate).

  Examples of the plasticizer (v3) include trimellitic acid esters (for example, tri-2-ethylhexyl trimellitic acid or trioctyl trimellitic acid) and the like.

  Examples of the plasticizer (v4) include phosphate esters (for example, triethyl phosphate, tri-2-ethylhexyl phosphate or tricresyl phosphate).

  Examples of the plasticizer (v5) include fatty acid esters (such as butyl oleate).

  Examples of the plasticizer (v6) include combinations of the materials listed in the plasticizers (v1) to (v5).

<Preparation of core resin (b) forming solution (Y)>
In the step of preparing the core resin (b) forming solution (Y), the core resin (b) or the precursor (b0) of the core resin (b) is dissolved in the organic solvent (M). Here, as the core resin (b), the resins mentioned in the above <core resin (b)> can be used.

  As a method for dissolving the core resin (b) or the precursor (b0) of the core resin (b) in the organic solvent (M), any method may be used, and a known method can be used. For example, the core resin (b) or the precursor (b0) of the core resin (b) is added to the organic solvent (M) and then stirred, and the core resin (b) or the core resin ( The method of heating after putting the precursor (b0) of b) is mentioned.

The organic solvent (M) is not particularly limited as long as it can dissolve the core resin (b) at room temperature or under heating, but the SP value of the organic solvent (M) is preferably 8.5 to 20 (cal / cm ³ ) ^1/2 , more preferably 10 to 19 (cal / cm ³ ) ^1/2 . When a mixed solvent is used as the organic solvent (M), the weighted average value of the SP values calculated from the SP values of the respective solvents on the assumption that additivity is established may be within the above range. If the SP value of the organic solvent (M) is outside the above range, the solubility of the core resin (b) or the precursor (b0) of the core resin (b) may be insufficient.

  The organic solvent (M) preferably has an SP value within the above range, and is preferably selected as appropriate depending on the material of the core resin (b) or the precursor of the core resin (b) (b0). . Examples of the organic solvent (M) include aromatic hydrocarbon solvents such as toluene, xylene, ethylbenzene and tetralin; aliphatic or alicyclic hydrocarbon solvents such as n-hexane, n-heptane, mineral spirit and cyclohexane. Halogenated solvents such as methyl chloride, methyl bromide, methyl iodide, methylene dichloride, carbon tetrachloride, trichloroethylene and perchloroethylene; esters such as ethyl acetate, butyl acetate, methoxybutyl acetate, methyl cellosolve acetate and ethyl cellosolve acetate Or ether ether solvents; ether solvents such as diethyl ether, THF, dioxane, ethyl cellosolve, butyl cellosolve and propylene glycol monomethyl ether; acetone, methyl ethyl Ketone solvents such as ketone, methyl isobutyl ketone, di-n-butyl ketone and cyclohexanone; alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol, 2-ethylhexyl alcohol and benzyl alcohol Amide solvents such as dimethylformamide and dimethylacetamide; sulfoxide solvents such as dimethyl sulfoxide; heterocyclic compounds solvents such as N-methylpyrrolidone; mixed solvents in which two or more of the above solvents are mixed, etc. Is mentioned.

  From the viewpoint of odor, the dispersion obtained from the dispersion (X ′) of the resin particles (the following <dispersion of the core resin (b) forming solution (Y) in the dispersion (W) of the shear particles (A))> The boiling point of the organic solvent (M) is preferably 100 ° C. or less, more preferably 90 ° C. or less, from the viewpoint of easiness of evaporation from the solvent.

  When a polyester resin, polyurethane resin or epoxy resin is selected as the core resin (b), preferred organic solvents (M) include, for example, acetone, dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone and a mixed solvent of two or more of these. Etc.

  From the viewpoint of the particle size distribution of the toner particles (C), the viscosity of the core resin (b) forming solution (Y) is preferably 10 to 50000 mPa · s, more preferably 100 to 10000 mPa · s. Here, the viscosity of the core resin (b) forming solution (Y) is preferably measured using, for example, a B-type viscometer. The organic solvent (M) is preferably selected so that the viscosity of the core resin (b) forming solution (Y) is within the above range.

  The precursor (b0) of the core resin (b) is not particularly limited as long as it can become the core resin (b) by a chemical reaction. For example, when the core resin (b) is a vinyl resin, the precursor (b0) of the core resin (b) is the monomer (1) to (9) (single) having the polymerizable double bond. Or may be used as a mixture of two or more thereof.

  When the monomers (1) to (9) having a polymerizable double bond are used as the precursor (b0) of the core resin (b), the precursor (b0) of the core resin (b) is reacted. As a method for forming the core resin (b), for example, an oil phase containing an oil-soluble initiator and a monomer is dispersed and suspended in an organic solvent (M), and the resulting suspension is subjected to radical polymerization by heating. The method of making it react is mentioned.

  Examples of the oil-soluble initiator include an oil-soluble peroxide polymerization initiator (I) and an oil-soluble azo polymerization initiator (II). Moreover, you may use the redox-type polymerization initiator (III) obtained by using a reducing agent together with oil-soluble peroxide type | system | group polymerization initiator (I). Furthermore, two or more of the oil-soluble peroxide polymerization initiator (I), the oil-soluble azo polymerization initiator (II) and the redox polymerization initiator (III) may be used in combination.

  Examples of the oil-soluble peroxide-based polymerization initiator (I) include acetyl peroxide, t-butylperoxy-2-ethylhexanoate, benzoyl peroxide, parachlorobenzoyl peroxide, and cumene peroxide. .

  Examples of the oil-soluble azo polymerization initiator (II) include 2,2′-azobisisobutyronitrile, 2,2′-azobis-2,4-dimethylvaleronitrile, dimethyl-2,2′-azobis. (2-methylpropionate) and 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile).

  Examples of the non-aqueous redox polymerization initiator (III) include oil-soluble peroxides such as hydroperoxides, dialkyl peroxides or diacyl peroxides, tertiary amines, naphthenates, mercaptans or organometallic compounds (for example, And those obtained by using an oil-soluble reducing agent such as triethylaluminum, triethylboron or diethylzinc).

  When the core resin (b) is a condensation resin (for example, polyurethane resin, epoxy resin or polyester resin), the precursor (b0) of the core resin (b) is a prepolymer having a reactive group (α ) (Hereinafter abbreviated as “prepolymer (α)”) and a curing agent (β).

  The “reactive group” of the prepolymer (α) refers to a group that can react with the curing agent (β). In this case, as a method of obtaining the core resin (b) by reacting the precursor (b0) of the core resin (b), the prepolymer (α) and the curing agent (β) are dispersed in the insulating liquid (L). For example, a method of reacting the prepolymer (α) and the curing agent (β) by heating.

Examples of the combination of the reactive group of the prepolymer (α) and the curing agent (β) include the following [14] to [15] [14]: The reactive group of the prepolymer (α) is: It is a functional group (α1) that can react with an active hydrogen compound, and the curing agent (β) is an active hydrogen group-containing compound (β1). [15] The reactive group that the prepolymer (α) has is an active hydrogen. It is a containing group (α2), and the curing agent (β) is a compound (β2) that can react with the active hydrogen-containing group.

  In the combination [14], examples of the functional group (α1) capable of reacting with the active hydrogen compound include an isocyanate group (α1a), a blocked isocyanate group (α1b), an epoxy group (α1c), and an acid anhydride group ( and α1d) and acid halide groups (α1e). Among these, the isocyanate group (α1a), the blocked isocyanate group (α1b) and the epoxy group (α1c) are preferable as the functional group (α1), and among these, the isocyanate group (α1c) is more preferable as the functional group (α1). A group (α1a) and a blocked isocyanate group (α1b).

  The blocked isocyanate group (α1b) refers to an isocyanate group blocked with a blocking agent. Examples of the blocking agent include oximes (for example, acetoxime, methyl isobutyl ketoxime, diethyl ketoxime, cyclopentanone oxime, cyclohexanone oxime, methyl ethyl ketoxime, etc.); lactams (for example, γ-butyrolactam, ε-caprolactam, etc. Or γ-valerolactam); aliphatic alcohols having 1 to 20 carbon atoms (for example, ethanol, methanol or octanol); phenols (for example, phenol, m-cresol, xylenol or nonylphenol); active methylene compounds (Eg acetylacetone, ethyl malonate or ethyl acetoacetate); basic nitrogen-containing compounds (eg N, N-diethylhydroxylamine, 2-hydroxypi Jin, pyridine N- oxide or 2-mercaptopyridine); and combinations of these and the like. Of these, oximes are preferred as the blocked isocyanate group (α1b), and methyl ethyl ketoxime is more preferred.

  Examples of the structural unit of the prepolymer (α) having a reactive group include polyether (αw), polyester (αx), epoxy resin (αy), and polyurethane (αz). Of these, polyester (αx), epoxy resin (αy) and polyurethane (αz) are preferred as the constituent unit of the prepolymer (α), and polyester (αx) and polyurethane (αz) are more preferred. .

  Examples of the polyether (αw) include polyethylene oxide, polypropylene oxide, polybutylene oxide, and polytetramethylene oxide.

  Examples of the polyester (αx) include a polycondensate of the diol (11) and the dicarboxylic acid (13) and a polylactone (for example, a ring-opening polymer of ε-caprolactone).

  Examples of the epoxy resin (αy) include addition condensates of bisphenols (for example, bisphenol A, bisphenol F or bisphenol S) and epichlorohydrin.

  Examples of the polyurethane (αz) include a polyaddition product of the diol (11) and the polyisocyanate (15) and a polyaddition product of the polyester (αx) and the polyisocyanate (15). .

Examples of the method for incorporating a reactive group into polyester (αx), epoxy resin (αy), polyurethane (αz) and the like include the methods shown in the following [16] to [17] [16]: Two or more components The functional group of the constituent component remains at the end by using one of them excessively. [17]: The functional group of the constituent component is terminated by using one of two or more constituent components in excess. Remaining (a prepolymer is obtained), and the remaining functional group is reacted with a functional group capable of reacting with the remaining functional group or a compound containing a functional group capable of reacting with the remaining functional group.

  In the method [16] above, a hydroxyl group-containing polyester prepolymer, a carboxyl group-containing polyester prepolymer, an acid halide group-containing polyester prepolymer, a hydroxyl group-containing epoxy resin prepolymer, an epoxy group-containing epoxy resin prepolymer, a hydroxyl group-containing polyurethane prepolymer, and An isocyanate group-containing polyurethane prepolymer or the like is obtained.

  For example, when obtaining a hydroxyl group-containing polyester prepolymer, the equivalent ratio ([OH] / [COOH]) of hydroxyl group [OH] and carboxyl group [COOH] is preferably 2/1 to 1/1. What is necessary is just to set the ratio of a polyol component and a polycarboxylic acid component so that it may preferably be set to 1.5 / 1 to 1/1, and more preferably to be 1.3 / 1 to 1.02 / 1. . Even when the skeleton is changed or when a prepolymer having a terminal group is obtained, it is preferable that the ratio of the constituent components is the same as that described above only by changing the constituent components.

  In the method [17] above, an isocyanate group-containing prepolymer is obtained by reacting the preprimer obtained in the method [16] with a polyisocyanate, and a blocked polyisocyanate is reacted to thereby contain a blocked isocyanate group. A prepolymer is obtained, an epoxy group-containing prepolymer is obtained by reacting a polyepoxide, and an acid anhydride group-containing prepolymer is obtained by reacting a polyacid anhydride.

  For example, when a polyisocyanate is reacted with a hydroxyl group-containing polyester prepolymer to obtain an isocyanate group-containing polyester prepolymer, the equivalent ratio of the isocyanate group [NCO] and the hydroxyl group [OH] of the hydroxyl group-containing polyester ([NCO] / [OH]) Is preferably 5/1 to 1/1, more preferably 4/1 to 1.2 / 1, and even more preferably 2.5 / 1 to 1.5 / 1. In addition, the ratio of the polyisocyanate to the hydroxyl group-containing polyester prepolymer may be set. Even when the skeleton is changed or when a prepolymer having a terminal group is obtained, it is preferable that the ratio of the constituent components is the same as that described above only by changing the constituent components.

  The number of reactive groups contained in one molecule of the prepolymer (α) is preferably 1 or more, more preferably 1.5 to 3 on average, and still more preferably 1.8 to 2 on average. Five. When the number of reactive groups contained in one molecule of the prepolymer (α) is within the above range, the molecular weight of the cured product obtained by reacting with the curing agent (β) increases.

  Mn of a prepolymer ((alpha)) becomes like this. Preferably it is 500-30000, More preferably, it is 1000-20000, More preferably, it is 2000-10000.

  Mw of a prepolymer ((alpha)) becomes like this. Preferably it is 1000-50000, More preferably, it is 2000-40000, More preferably, it is 4000-20000.

  The viscosity of the prepolymer (α) is preferably 200 Pa · s or less, more preferably 100 Pa · s or less, at 100 ° C. By setting the viscosity of the prepolymer (α) to 200 Pa · s or less, core particles (B) having a narrow distribution width in the particle size distribution can be obtained.

  As the active hydrogen group-containing compound (β1) in the above combination [14], for example, polyamine (β1a) which may be blocked with a detachable compound (hereinafter abbreviated as “polyamine (β1a)”); Examples include polyol (β1b); polymercaptan (β1c); water and the like. Of these, the active hydrogen group-containing compound (β1) is preferably a polyamine (β1a), a polyol (β1b) and water, more preferably a polyamine (β1a) and water, and more preferably a block. Polyamines and water.

  Examples of the polyamine (β1a) include those listed as specific examples of the polyamine (15). The polyamine (β1a) is preferably 4,4′-diaminodiphenylmethane, xylylenediamine, isophoronediamine, ethylenediamine, diethylenetriamine, triethylenetetramine or a mixture thereof.

  When the polyamine (β1a) is a polyamine blocked with a detachable compound, examples of the polyamine include the polyamines and ketones having 3 to 8 carbon atoms (for example, acetone, methyl ethyl ketone or methyl). A ketimine compound obtained from an isobutyl ketone and the like; an aldimine compound obtained from an aldehyde compound having 2 to 8 carbon atoms (eg, formaldehyde or acetaldehyde); an enamine compound; an oxazolidine compound and the like.

  Examples of the polyol (β1b) include the same as those listed as specific examples of the diol (10) and the polyol (11). Among these, preferred as the polyol (β1b) are the diol (10) alone and a mixture of the diol (10) and a small amount of polyol (11).

  Examples of the polymercaptan (β1c) include ethanedithiol, 1,4-butanedithiol, 1,6-hexanedithiol, and the like.

  If necessary, a reaction terminator (βs) can be used together with the active hydrogen group-containing compound (β1). By using the reaction terminator (βs) in combination with the active hydrogen group-containing compound (β1) at a certain ratio, it is possible to adjust the molecular weight of the core resin (b) to a predetermined value. For the same reason, a reaction terminator (βs) can be used together with the compound (β2) capable of reacting with the active hydrogen-containing group in the combination [15].

  Examples of the reaction terminator (βs) include monoamines (eg, diethylamine, dibutylamine, butylamine, laurylamine, monoethanolamine or diethanolamine); monoamines blocked (eg, ketimine compounds); monools (eg, Such as methanol, ethanol, isopropanol, butanol or phenol); monomercaptan (eg, butyl mercaptan or lauryl mercaptan); monoisocyanate (eg, lauryl isocyanate or phenyl isocyanate); monoepoxide (eg, butyl glycidyl ether), etc. It is done.

  Examples of the active hydrogen-containing group (α2) of the prepolymer (α) in the combination [15] include an amino group (α2a), a hydroxyl group (for example, an alcoholic hydroxyl group or a phenolic hydroxyl group) (α2b), mercapto And a group (α2c), a carboxyl group (α2d), and an organic group (α2e) blocked with a compound from which they can be removed. Among these, an amino group (α2a), a hydroxyl group (α2b) and an organic group (α2e) are preferable, and a hydroxyl group (α2b) is more preferable.

  Examples of the organic group (α2e) blocked with a compound capable of removing an amino group include those listed as specific examples of the polyamine (β1a).

  Examples of the compound (β2) capable of reacting with the active hydrogen-containing group in the combination [15] include, for example, polyisocyanate (β2a), polyepoxide (β2b), polycarboxylic acid (β2c), polyanhydride (β2d) and Examples include polyacid halide (β2e). Of these, polyisocyanate (β2a) and polyepoxide (β2b) are preferable as the compound (β2), and polyisocyanate (β2a) is more preferable.

  Examples of the polyisocyanate (β2a) include those listed as specific examples of the polyisocyanate (14). Preferred examples of the polyisocyanate (β2a) include preferable specific examples of the polyisocyanate (14). As listed above.

  Examples of the polyepoxide (β2b) include those listed as specific examples of the polyepoxide (18). Preferred examples of the polyepoxide (β2b) include those listed as preferable specific examples of the polyepoxide (18). It is the same.

  Examples of the polycarboxylic acid (β2c) include dicarboxylic acid (β2c-1) and trivalent or higher polycarboxylic acid (β2c-2). Among these, the polycarboxylic acid (β2c) is preferably a polycarboxylic acid (β2c). It is a mixture of dicarboxylic acid (β2c-1) alone and dicarboxylic acid (β2c-1) and a small amount of polycarboxylic acid (β2c-2).

  Examples of the dicarboxylic acid (β2c-1) include those listed as specific examples of the dicarboxylic acid (12) and the polycarboxylic acid (13), and are preferable as the dicarboxylic acid (β2c-1). These are the same as those listed as preferred specific examples of the dicarboxylic acid (12) and the polycarboxylic acid (13).

  Examples of the polycarboxylic acid anhydride (β2d) include pyromellitic acid anhydride.

  Examples of the polyacid halides (β2e) include acid halides of the polycarboxylic acid (β2c) (for example, acid chloride, acid bromide, or acid iodide).

  The ratio of the curing agent (β) in the precursor (b0) of the core resin (b) is not particularly limited. The equivalent ratio ([α] / [β]) of the reactive group [α] in the prepolymer (α) and the active hydrogen-containing group [β] in the curing agent (β) is preferably 1 / 2-2. / 1, more preferably from 1.5 / 1 to 1 / 1.5, and even more preferably from 1.2 / 1 to 1 / 1.2, the core resin (b) The ratio of the curing agent (β) in the precursor (b0) may be set. In addition, when a hardening | curing agent ((beta)) is water, water is handled as a bivalent active hydrogen compound.

<Preparation of colorant dispersion>
In the step of preparing the dispersion of the colorant, the colorant may be dispersed in at least one of the dispersion (W) of the shell particles (A) and the core resin (b) forming solution (Y), After dispersing the colorant in a predetermined organic solvent, the dispersion may be mixed with at least one of the dispersion (W) of the shell particles (A) and the solution (Y) for forming the core resin (b). .

  As the colorant, at least one of the pigments listed in the above <colorant> can be used. As the solution for dissolving or dispersing the colorant, for example, an organic solvent such as acetone can be used.

<Dispersing solution (Y) for forming core resin (b) in dispersion (W) of shell particles (A)>
In the step of dispersing the core resin (b) forming solution (Y) in the dispersion (W) of the shell particles (A), the dispersion (W) of the shell particles (A) and the core resin (b) forming solution ( Y). As a result, the core resin (b) forming solution (Y) is dispersed in the dispersion of the shell particles (A), and the third resin particles (C ′) having a core / shell structure [that is, the shell particles (A) are A third resin particle (C ′)] is obtained which is attached or coated on the surface of the core particle (B) containing the core resin (b). When the core resin (b) forming solution (Y) contains the precursor (b0) of the core resin (b), the precursor (b0) of the core resin (b) reacts to react with the core resin (b And core particles (B) containing the core resin (b) are formed.

  The method for dispersing the core resin (b) forming solution (Y) in the dispersion liquid (W) of the shell particles (A) is not particularly limited, but the core resin (b) forming solution (Y) is dispersed using a dispersing device. It is preferable to disperse in the dispersion liquid (W) of the shell particles (A).

  Generally as a dispersion apparatus, if it is marketed as an emulsifier or a disperser, it can be used without being specifically limited. Examples of the dispersing apparatus include batch type emulsifiers such as homogenizer (manufactured by IKA), polytron (manufactured by Kinematica) and TK auto homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.); Mfg. Co., Ltd.), TK Philmix, TK Pipeline Homomixer (made by Special Machine Industries Co., Ltd.), Colloid Mill (made by Shinko Pantech Co., Ltd.), Thrasher, Trigonal Wet Mill (Mitsui Miike Chemical Co., Ltd. )), Capitolon (manufactured by Eurotech) and fine flow mill (manufactured by Taiheiyo Kiko Co., Ltd.), etc .; High-pressure emulsifiers such as Gaulin (manufactured by Gaurin); Chromatography (Hiyaka Kogyo Co.) vibration type emulsifying machine such as; such as an ultrasonic emulsifier such as an ultrasonic homogenizer (manufactured by Branson Co., Ltd.). Among these apparatuses, APV Gaurin, homogenizer, TK auto homomixer, Ebara milder, TK fill mix, and TK pipeline homomixer are preferable from the viewpoint of the particle size distribution of the toner particles.

  The temperature when the core resin (b) forming solution (Y) is dispersed in the dispersion liquid (W) of the shell particles (A) is not particularly limited, but is preferably 0 to 150 ° C. (under pressure), more Preferably it is 5-98 degreeC. Viscosity of a solution obtained by dispersing the core resin (b) forming solution (Y) in the dispersion (W) of the shell particles (A) (dispersion (X ′) of the third resin particles (C ′)). Is high, the core resin (b) forming solution (Y) is increased by increasing the temperature at which the core resin (b) forming solution (Y) is dispersed in the dispersion (W) of the shell particles (A). It is preferable to lower the viscosity to a preferable range. The preferable range of the viscosity of the core resin (b) forming solution (Y) is as described above in <Preparation of the core resin (b) forming solution (Y)>, and ranges from 10 to 50,000 mPa · s ( (Viscosity measured with a B-type viscometer).

  The mixing ratio of the dispersion (W) of the shell particles (A) and the core resin (b) forming solution (Y) is not particularly limited. However, the dispersion (W) of the shell particles (A) is 100 masses of the core resin (b) or the core resin (b) precursor (b0) dissolved in the core resin (b) forming solution (Y). It is preferable that 50-2,000 mass parts is contained with respect to a part, and it is more preferable that 100-1,000 mass parts is contained. If the dispersion (W) of the shell particles (A) is contained in an amount of 50 parts by mass or more with respect to 100 parts by mass of the core resin (b) or the precursor (b0) of the core resin (b), the third resin particles ( The dispersion state of the core resin (b) or the precursor (b0) of the core resin (b) in the dispersion (X ′) of C ′) is improved. It is economical if the dispersion (W) of the shell particles (A) is contained in an amount of 2,000 parts by mass or less with respect to 100 parts by mass of the core resin (b) or the precursor (b0) of the core resin (b). is there.

The core-shell structure is formed by dispersing the core resin (b) forming solution (Y) in the dispersion (W) of the shell particles (A). The adsorption force is preferably controlled according to the method shown in the following [18] to [20]. [18]: The shell particles (A) and the core particles (B) are charged with opposite polarities. At this time, the larger the charge of each of the shell particles (A) and the core particles (B), the stronger the adsorption force of the shell particles (A) to the core particles (B). [19]: When the shell particle (A) and the core particle (B) have the same polar charge, the shell particle on the surface of the core particle (B) is increased. The coverage of (A) becomes low. At this time, if at least one of the surfactant (s) and the oily polymer (t) (especially those having the opposite polarity between the shell particles (A) and the core particles (B)) is used, the core particles (B ), And the coverage of the shell particles (A) on the surface of the core particles (B) is increased. [20] Dispersion liquid (W) of shell particles (A) And the core resin (b) forming solution (Y), if the SP value difference is reduced, the adsorption force of the shell particles (A) to the core particles (B) increases, and thus the shell to the surface of the core particles (B). The coverage of the particles (A) is increased.

  A core-shell structure in which the shell particles (A) are attached to the surfaces of the core particles (B) is formed, or the core particles in which the shell particles (A) are coated on the surfaces of the core particles (B). Whether the shell structure is formed depends on the physical properties of the organic solvent (M) contained in the core resin (b) forming solution (Y), specifically, the shell particles (A) and / or the core with respect to the organic solvent (M). It depends on the solubility of the resin (b).

  Specifically, if the organic solvent (M) that dissolves the core resin (b) but does not dissolve the shell particles (A) is selected, the shell particles (A) are attached to the surface of the core particles (B). .

  On the other hand, when an organic solvent (M) that dissolves both the shell particles (A) and the core resin (b) is selected, the shell particles (A) are melted in the organic solvent (M). ) Adheres to the surface. Therefore, when the organic solvent (M) is distilled off in a later step, the organic solvent (M) adhering to the surface of the core particle (B) is also distilled off. Particles (A) are formed into a film. Hereinafter, forming the shell particles (A) in the form of a film on the surface of the core particles (B) will be referred to as “film formation treatment”.

  In order to perform the film-forming treatment, it is preferable to select THF, toluene, acetone, methyl ethyl ketone, or ethyl acetate as the organic solvent (M), and it is more preferable to select acetone, ethyl acetate, or the like.

  When the coating treatment is performed, the content of the organic solvent (M) in the dispersion (X ′) of the third resin particles (C ′) is preferably 10 to 50% by mass, more preferably 20 to 40% by mass. %. When the organic solvent (M) is distilled off after the coating treatment, the content of the organic solvent (M) in the dispersion (X ′) of the third resin particles (C ′) is 40 ° C. or lower. The organic solvent (M) may be removed until preferably 1% by mass or less, more preferably 0.5% by mass or less. Thereby, the shell layer consisting of the shell particles (A) dissolved in the organic solvent (M) is formed on the surface of the core layer composed of the core particles (B).

  When the film forming process is performed, an organic solvent used in the film forming process can be added to the dispersion liquid (X ′) of the third resin particles (C ′). However, it is preferable to use the organic solvent (M) contained in the core resin (b) forming solution (Y) as a film-forming organic solvent without removing it after forming the core particles (B). Because the organic solvent (M) is contained in the core particle (B), the shell particle (A) can be easily dissolved in the organic solvent (M). It is because it becomes difficult to occur.

  When the shell particles (A) are dissolved in the organic solvent (M), the concentration of the organic solvent (M) in the dispersion (X ′) of the third resin particles (C ′) is preferably 3 to 50% by mass. More preferably, it is 10-40 mass%, More preferably, it is 15-30 mass%. Moreover, it is preferable to stir the dispersion liquid (X ′) of the third resin particles (C ′) for 1 to 10 hours, for example. Furthermore, the temperature at which the shell particles (A) are dissolved in the organic solvent (M) is preferably 15 to 45 ° C, and more preferably 15 to 30 ° C.

  When the shell particles (A) are dissolved in the organic solvent (M) and coated on the surface of the core particles (B), the solid content (solvent) in the dispersion (X ′) of the third resin particles (C ′) The content of other components is preferably 1 to 50% by mass, more preferably 5 to 30% by mass. In addition, the content of the organic solvent (M) before the film-forming treatment is preferably 2% by mass or less, more preferably 1% by mass or less, and further preferably 0.5% by mass or less. When the solid content in the dispersion (X ′) of the third resin particles (C ′) is high, and when the content of the organic solvent (M) before the coating treatment exceeds 2% by mass, When the dispersion (X ′) of the third resin particles (C ′) is heated to 60 ° C. or higher, aggregates may be generated. Moreover, the melting method of the shell particles (A) is not particularly limited, and for example, preferably 40 to 100 ° C., more preferably 60 to 90 ° C., still more preferably 60 to 80 ° C., and preferably 1 under stirring. The method etc. which heat for -300 minutes are mentioned.

  When the coating treatment is performed, the dispersion (X ′) of the third resin particles (C ′) having an organic solvent (M) content of 2% by mass or less before the coating treatment is heated to form shell particles (A). Is preferably melted on the surface of the core particle (B). Thereby, toner particles (C) having a smoother surface can be obtained. The heating temperature at this time is preferably equal to or higher than Tg of the shell resin (a), and more preferably equal to or lower than 80 ° C. If the heating temperature is lower than the Tg of the shell resin, the effect obtained by heating (that is, the effect of further smoothing the surface of the toner particles) may not be obtained. On the other hand, when the heating temperature exceeds 80 ° C., the shell layer may be peeled off from the core layer.

  A preferable method for the coating treatment is a method of melting the shell particles (A) and a combination of a method of dissolving the shell particles (A) and a method of melting the shell particles (A).

<Addition of alcohol>
In the step of adding alcohol, the organic solvent (M) is distilled off from the dispersion (X ′) of the third resin particles (C ′), and then the alcohol is added. Thereby, toner particles (C) whose surfaces of the third resin particles (C ′) are modified are obtained. As a result, a liquid developer in which the toner particles (C) are dispersed in the insulating liquid (L) is obtained.

  The method for distilling off the organic solvent (M) from the dispersion (X ′) of the third resin particles (C ′) is not particularly limited, but is, for example, 20 ° C. or higher under a reduced pressure of 0.02 to 0.066 MPa. The method of distilling off the said organic solvent (M) at the temperature below the boiling point of an organic solvent (M), etc. are mentioned.

  The content rate of the organic solvent (M) in the dispersion liquid after distilling off the organic solvent (M) is preferably 1% by mass or less, more preferably 0.5% by mass or less. A part of the insulating liquid (L) (for example, a low boiling point component in the insulating liquid (L)) may be distilled off together with the organic solvent (M).

  As a method of adding alcohol to the dispersion liquid after distilling off the organic solvent (M), a method of adding 10 ppm or more and 1000 ppm or less of alcohol to the solid content of the toner particles (C) may be used. A method may be used in which excess alcohol is removed after adding alcohol exceeding 1000 ppm to the solid content of the toner particles (C). The alcohol to be added is preferably an alcohol mixed with the insulating liquid (L), and is preferably an alcohol having a basic alcohol group. Specific examples of the alcohol to be added include, as described above, ethanol, propanol, butanol, methyl celsorob, butyl celsorob, and the like.

  The shape of the toner particles (C) and the smoothness of the surface of the toner particles (C) contained in the liquid developer thus obtained are the SP value difference between the shell resin (a) and the core resin (b), And it controls by controlling at least one of the molecular weight of core resin (a). If the SP value difference is too small, it is easy to obtain toner particles having a distorted shape but a smooth surface. Conversely, when the SP value difference is too large, toner particles having a spherical shape but having a rough surface are likely to be obtained. When the molecular weight of the shell resin (a) is too large, toner particles having a rough surface are easily obtained, and when the molecular weight of the shell resin (a) is too small, toner particles having a smooth surface are easily obtained. Further, if the SP value difference is too small or too large, granulation is difficult. Moreover, even if the molecular weight of the shell resin (a) is too small, granulation is difficult. From the above, the SP value difference is preferably 0.01 to 5.0, more preferably 0.1 to 3.0, and still more preferably 0.2 to 2.0. Moreover, Mw of shell resin (a) becomes like this. Preferably it is 100-1 million, More preferably, it is 1000-500000, More preferably, it is 2000-200000, Most preferably, it is 3000-100000.

  In addition, when manufacturing the core-shell structure in this Embodiment, after manufacturing a core particle (B) according to the manufacturing method in any one of said [7]-[13], the said core particle (B) Shell particles (A) may be attached to or coated on the surface of these.

  Further, in the method for producing a liquid developer according to the present embodiment, additives other than the colorant (for example, filler, antistatic agent, mold release agent, charge control agent, ultraviolet absorber, antioxidant, antiblocking) And at least one of a dispersion liquid (W) of the shell particles (A), a solution (Y) for forming the core resin (b), and a dispersion liquid of the colorant is prepared by adding an agent, a heat stabilizer and a flame retardant. May be. Also in this case, the additive is added to the dispersion (W) of the shell particles (A) by adding a solution in which an additive other than the colorant is dissolved or dispersed to the dispersion (W) of the shell particles (A). Can be added. As a result, toner particles (C) in which additives other than the colorant are also contained in at least one of the core layer and the shell layer can be obtained.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these.

<Production Example 1> [Production of dispersion liquid (W1) of shell particles (A)]
In a glass beaker, 100 parts by mass of (meth) acrylic acid 2-decyltetradecyl, 30 parts by mass of methacrylic acid, 70 parts by mass of an equimolar reaction product of hydroxyethyl methacrylate and phenyl isocyanate, and azobismethoxydimethylvaleronitrile 0.5 parts by mass was added and mixed with stirring at 20 ° C. Thereby, a monomer solution was obtained.

  Next, a reaction vessel equipped with a stirrer, a heating / cooling device, a thermometer, a dropping funnel, a solvent removal device, and a nitrogen introduction tube was prepared. 195 parts by mass of THF was put into the reaction vessel, and the monomer solution was put into a dropping funnel provided in the reaction vessel. After the gas phase portion of the reaction vessel was replaced with nitrogen, the monomer solution was added dropwise to THF in the reaction vessel over 1 hour at 70 ° C. in a sealed state. Three hours after the completion of the dropwise addition of the monomer solution, a mixture of 0.05 parts by mass of azobismethoxydimethylvaleronitrile and 5 parts by mass of THF was placed in a reaction vessel, reacted at 70 ° C. for 3 hours, and then cooled to room temperature. . Thereby, a copolymer solution was obtained.

  After 400 parts by mass of the obtained copolymer solution was added dropwise to 600 parts by mass of Isopar L (exxon mobile) under stirring, THF was distilled off at 40 ° C. under a reduced pressure of 0.039 MPa. Thereby, a dispersion liquid (W1) of shell particles (A) was obtained.

  When the volume average particle diameter of the shell particles (A) in the dispersion liquid (W1) was measured using a laser type particle size distribution measuring apparatus (“LA-920” manufactured by Horiba, Ltd.), it was 0.12 μm. . Further, a part of the dispersion liquid (W1) is vacuum-dried to volatilize Isopar L to produce a solid sample of shell particles (A), and the Tg of the solid sample of shell particles (A) according to the DSC method. Was 60 ° C.

<Production Example 2> [Production of core resin (b1) forming solution (Y1)]
In a reaction vessel equipped with a stirrer, a heating / cooling device, a thermometer, and a nitrogen introduction tube, 746 parts by mass of ethylene glycol, 288 parts by mass of sebacic acid and 3 parts by mass of tetrabutoxy titanate as a condensation catalyst were placed. The polycondensation product was obtained by polycondensation under normal pressure at 230 ° C. for 6 hours. The reaction vessel was depressurized, and when the acid value of the polycondensate reached 1.0, the internal pressure of the reaction vessel was returned to normal pressure and cooled to 180 ° C. At 180 ° C., 28 parts by mass of trimellitic anhydride was placed in a reaction vessel and reacted at 180 ° C. for 1 hour. This obtained core resin (b1) which is a polyester resin.

  In a beaker, 1000 parts by mass of the core resin (b1) and 1000 parts by mass of acetone were added and stirred to uniformly dissolve the core resin (b1) in acetone. As a result, a solution (Y1) for forming the core resin (b1) was obtained.

<Production Example 3> [Production of Core Resin (b2) Formation Solution (Y2)]
In a reaction vessel equipped with a stirrer, a heating / cooling device, a thermometer, a solvent removal device and a nitrogen introduction tube, 701 parts by mass of 1,2-propylene glycol (hereinafter abbreviated as “PG”), 716 parts by mass of dimethyl terephthalate 180 parts by mass of adipic acid and 3 parts by mass of tetrabutoxy titanate as a condensation catalyst were added. The reaction was carried out for 8 hours while distilling off methanol at 180 ° C. under a nitrogen stream. Then, it was made to react for 4 hours, heating up gradually to 230 degreeC and distilling off PG and water under nitrogen stream. Then, it was made to react under the reduced pressure of 0.007-0.026 MPa, and it took out when the softening point became 150 degreeC. This obtained core resin (b2) which is a polyester resin. The recovered PG was 316 parts by mass.

  In a beaker, 1000 parts by mass of the core resin (b2) and 1000 parts by mass of acetone were stirred and the core resin (b2) was uniformly dissolved in acetone. As a result, a solution (Y2) for forming the core resin (b2) was obtained.

<Production Example 4> [Production of Colorant Dispersion]
In a beaker, 250 parts by mass of copper phthalocyanine, 40 parts by mass of a dispersant “Ajisper PB-821” (manufactured by Ajinomoto Fine Techno Co., Ltd.) and 750 parts by mass of acetone were stirred to uniformly disperse copper phthalocyanine. Thereafter, copper phthalocyanine was finely dispersed by a bead mill. As a result, a dispersion of the colorant was obtained. The volume average particle diameter of copper phthalocyanine in the colorant dispersion was 0.2 μm.

<Example 1>
In a beaker, 450 parts by mass of the core resin (b1) forming solution (Y1) obtained in Production Example 2 and 150 parts by mass of the colorant dispersion obtained in Production Example 4 were placed, and a TK auto homomixer at 25 ° C. It was made to stir at 8000 rpm using (special machine chemical industry make). As a result, a resin solution (Y11) in which a colorant (copper phthalocyanine) was uniformly dispersed was obtained.

  In another beaker, 670 parts by mass of liquid paraffin and 600 parts by mass of the dispersion (W1) were added to uniformly disperse the shell particles (A). At 25 ° C., 60 parts by mass of the resin solution (Y11) was added while stirring at 10000 rpm using a TK auto homomixer, and stirred for 2 minutes.

  The mixed solution thus obtained was placed in a reaction vessel equipped with a stirrer, a heating / cooling device, a thermometer, and a solvent removal device, and the temperature was raised to 35 ° C. Acetone was distilled off at 35 ° C. under a reduced pressure of 0.039 MPa until the acetone concentration in the mixture was 0.5 mass% or less. Thereby, the precursor of the liquid developer was obtained. The solid content concentration of the toner particles in the liquid developer precursor was 33% by mass.

  30 mg of isopropanol was added to 800 g of the liquid developer precursor to obtain a liquid developer according to this example. According to the method described in [Liquid Developer] above, the content of isopropanol dissolved in the liquid developer was measured. The content was 100 ppm based on the solid content of the toner particles (C). Further, the volume average particle diameter of the toner particles was measured by using a flow type particle image analyzer (product number “FPIA-3000S”, manufactured by Sysmex Corporation), and found to be 1.8 μm.

<Example 2>
450 parts by mass of the core resin (b2) forming solution (Y2) obtained in Production Example 3 and 150 parts by mass of the colorant dispersion obtained in Production Example 4 were placed in a beaker, and a TK auto homomixer at 25 ° C. It was made to stir at 8000 rpm using (special machine chemical industry make). As a result, a resin solution (Y21) in which a colorant (copper phthalocyanine) was uniformly dispersed was obtained.

  In another beaker, 670 parts by mass of liquid paraffin and 600 parts by mass of the dispersion (W1) were added to uniformly disperse the shell particles (A). While being stirred at 10000 rpm using a TK auto homomixer at 25 ° C., 60 parts by mass of a resin solution (Y21) was added. And it was made to stir for 2 minutes.

  The mixed solution thus obtained was placed in a reaction vessel equipped with a stirrer, a heating / cooling device, a thermometer, and a solvent removal device, and the temperature was raised to 35 ° C. Acetone was distilled off at 35 ° C. under a reduced pressure of 0.039 MPa until the acetone concentration in the mixture was 0.5 mass% or less. Thereby, the precursor of the liquid developer was obtained. The solid content concentration of the toner particles in the liquid developer precursor was 33% by mass.

  280 mg of ethanol was added to 800 g of the liquid developer precursor to obtain a liquid developer according to this example. When the content of ethanol dissolved in the liquid developer was measured according to the method described in Example 1, the content was 970 ppm with respect to the solid content of the toner particles (C).

<Example 3>
In a beaker, 450 parts by mass of the core resin (b1) forming solution (Y1) obtained in Production Example 2 and 150 parts by mass of the colorant dispersion obtained in Production Example 4 were placed, and a TK auto homomixer at 25 ° C. It was made to stir at 8000 rpm using (special machine chemical industry make). As a result, a resin solution (Y11) in which a colorant (copper phthalocyanine) was uniformly dispersed was obtained.

  In another beaker, 670 parts by mass of liquid paraffin and 600 parts by mass of the dispersion (W1) were added to uniformly disperse the shell particles (A). While being stirred at 10000 rpm using a TK auto homomixer at 25 ° C., 60 parts by mass of a resin solution (Y11) was added. And it stirred for 2 minutes.

  The mixed solution thus obtained was placed in a reaction vessel equipped with a stirrer, a heating / cooling device, a thermometer, and a solvent removal device, and the temperature was raised to 35 ° C. Acetone was distilled off at 35 ° C. under a reduced pressure of 0.039 MPa until the acetone concentration in the mixture was 0.5 mass% or less. Thereby, the precursor of the liquid developer was obtained. The solid content concentration of the toner particles in the liquid developer precursor was 33% by mass.

  400 g of isopropanol was added to and mixed with 800 g of the liquid developer precursor. Centrifugation was performed on the obtained mixed solution, and the supernatant was removed. Then, the same amount of Isopar L as that of the removed supernatant was added. Centrifugation with respect to the mixed solution, removal of the supernatant, and addition of Isopar L were performed twice in this order. As a result, a liquid developer according to this example was obtained.

  The concentration of the fixed part of the toner particles in the obtained liquid developer was 30% by mass. When the content of ethanol dissolved in the liquid developer was measured according to the method described in Example 1, the content was 12 ppm based on the solid content of the toner particles (C).

<Comparative Example 1>
A liquid developer of Comparative Example 1 was produced in the same manner as in Example 1 except that the step of adding 30 mg of isopropanol to 800 g of the liquid developer precursor was not performed. That is, the liquid developer of Comparative Example 1 was a precursor of the liquid developer in Example 1 above.

  When the content of isopropanol dissolved in the liquid developer in this comparative example was measured according to the method described in Example 1, the content was less than the detection limit.

<Comparative example 2>
A liquid developer of Comparative Example 2 was produced in the same manner as in Example 1 except that the amount of isopropanol added to 800 g of the liquid developer precursor was changed to 450 mg.

  When the content of isopropanol dissolved in the liquid developer in this comparative example was measured according to the method described in Example 1, it was 1500 ppm with respect to the solid content of the toner particles (C).

<Comparative Example 3>
A liquid developer of Comparative Example 3 was produced in the same manner as in Example 1 except that Solsperse 11200 (manufactured by Lubrizol) was used instead of the dispersion liquid (W1).

<Evaluation method>
The redispersibility, heat-resistant storage stability, and chargeability of the toner particles contained in the liquid developers of Examples 1 to 3 and Comparative Examples 1 to 3 were evaluated.

<Redispersibility>
20 cc of each liquid developer of Examples 1 to 3 and Comparative Examples 1 to 3 was placed in a screw tube and stored at room temperature for 1 month. When the liquid developer after storage was observed, the toner particles settled in all cases. After the screw tube containing the wet developer separated into solid and liquid was shaken 10 times by hand, the state of toner particles in the liquid developer was observed.

  The results are shown in Table 1. In Table 1, “IPA” represents isopropanol. “Content ratio” represents the amount of alcohol dissolved in the insulating liquid with respect to the solid content of the toner particles. “Volume average particle diameter” represents the volume average particle diameter of toner particles contained in the liquid developer before storage, and is a value measured according to the method described in Example 1 above.

  In Table 1, the case where the state of toner particles in the liquid developer has returned to the state before storage, that is, the case where no toner particles settled in the liquid developer were confirmed, is denoted as “A1”. A case where toner particles settled in the developer are confirmed is denoted as “B1”. The smaller the toner particles that have settled in the liquid developer, the better the redispersibility of the toner particles.

  As shown in Table 1, in Examples 1 to 3 and Comparative Examples 2 to 3, the toner particles were excellent in redispersibility, but in Comparative Example 1, the toner particles were not excellent in redispersibility. The reason for this is not clear, but may be as follows. In the liquid developers of Examples 1 to 3 and Comparative Examples 2 to 3, the alcohol is dissolved in the insulating liquid, and it is considered that the surface of the toner particles is modified by the alcohol. If the surface of the toner particles is modified, it is considered that a cause (for example, electric charge) that causes a repulsive force between the toner particles may occur on the surface of the toner particles. As a result, it is considered that toner particles excellent in redispersibility could be provided. On the other hand, in the liquid developer of Comparative Example 1, since the alcohol is not dissolved in the insulating liquid, the surface of the toner particles is not modified. Therefore, the surface of the toner particles has a repulsive force between the toner particles. It is thought that the cause (for example, electric charge etc.) to cause does not occur easily. As a result, it is considered that the redispersibility of the toner particles is lowered.

<Heat resistant storage stability>
The volume average particle diameters of the toner particles contained in the liquid developers of Examples 1 to 3 and Comparative Examples 1 to 3 were measured.

Next, 20 cc of each liquid developer of Examples 1 to 3 and Comparative Examples 1 to 3 was placed in a screw tube and stored at 60 ° C. for 1 day. The volume average particle diameter of the toner particles in the liquid developer after storage was measured. Then, the change rate of the volume average particle size of the toner particles was calculated according to the following formula (change rate of the volume average particle size of the toner particles) = (volume average particle size of the toner particles after storage) / (before storage) Volume average particle diameter of toner particles).

  The volume average particle diameter of the toner particles was measured using a flow type particle image analyzer (product number “FPIA-3000S”, manufactured by Sysmex Corporation) even after storage.

  The results are shown in Table 1. In Table 1, a case where the change rate of the volume average particle diameter of the toner particles is less than 1.2 is described as “A2”, and a case where the change rate is 1.2 or more is described as “B2”. . A smaller change rate of the volume average particle diameter of the toner particles indicates that the aggregation of the toner particles due to storage at a high temperature is prevented, and thus the toner particles are excellent in heat-resistant storage stability.

  As shown in Table 1, in Examples 1 to 3 and Comparative Examples 1 and 2, the toner particles were excellent in heat-resistant storage stability, but in Comparative Example 3, the toner particles were not excellent in heat-resistant storage stability. The reason is considered as follows. In Examples 1 to 3 and Comparative Examples 1 and 2, the toner particles have a core / shell structure, and the shell layer constituting the core / shell structure melts even under high temperature (60 ° C. in this example). hard. Therefore, aggregation of toner particles can be prevented even when the liquid developer is stored at a high temperature. On the other hand, in Comparative Example 3, the toner particles do not have a core / shell structure, and the resin is melted when stored at a high temperature. Therefore, storage of the liquid developer at a high temperature causes aggregation of toner particles.

  In Examples 1 to 3 and Comparative Examples 1 and 2, since aggregation of toner particles can be prevented even when the liquid developer is stored at a high temperature, it is not necessary to use a resin having a high melting temperature. Therefore, fixing at a low temperature is possible. On the other hand, in Comparative Example 3, when the liquid developer is stored at a high temperature, toner particles are aggregated. Therefore, the heat-resistant storage stability of the toner particles is improved by using a resin having a high melting temperature. Therefore, the fixing temperature is increased.

<Chargeability>
Using the apparatus shown in FIG. 1, the chargeability of the toner particles contained in the liquid developers of Examples 1 to 3 and Comparative Examples 1 to 3 was measured.

Specifically, the liquid developer 12 was applied to an aluminum-deposited PET (a PET (poly (ethylene terephthalate)) film 11 on which aluminum was vapor-deposited) so that the coating amount was 3 g / m ² . Aluminum vapor-deposited PET 11 coated with the liquid developer 12 was attached to a cylindrical metal roller 13, and the metal roller 13 was rotated at a speed of 300 mm / sec. Further, a current was supplied from the constant current source 14 to the charger 15, and a current of 20 μA / cm was applied to the rotating metal roller 13 in the charger 15. Then, the surface potential of the liquid developer 12 was measured with a surface potential meter 16, and the output value of the surface potential meter 16 was monitored with an oscilloscope 17.

  The results are shown in Table 1. In Table 1, the case where the surface potential of the liquid developer 12 monitored by the oscilloscope 17 is 10 V or more is indicated as “A3”, and the case where the surface potential is less than 10 V is indicated as “B3”. The higher the output value of the surface potential meter 16, the better the chargeability of the toner particles, and thus the higher the density image can be obtained.

  In Examples 1 to 3, Comparative Example 1 and Comparative Example 3, the surface potential of the liquid developer was higher than that of Comparative Example 2. Therefore, it is considered that a higher density image can be obtained when the liquid developers of Examples 1 to 3, Comparative Example 1 and Comparative Example 3 are used than when the liquid developer of Comparative Example 2 is used. . The reason is considered as follows. In Comparative Example 2, since the content of the alcohol dissolved in the insulating liquid exceeds 1000 ppm with respect to the solid content of the toner particles, the dielectric constant of the insulating liquid may become too high. As a result, the insulating property of the insulating liquid is impaired, leading to a decrease in chargeability of the toner particles. On the other hand, in Examples 1 to 3, Comparative Example 1 and Comparative Example 3, the content of the alcohol dissolved in the insulating liquid is 1000 ppm or less with respect to the solid content of the toner particles. Is prevented from becoming too high. Thereby, since the insulating property of the insulating liquid is maintained, the chargeability of the toner particles is maintained. Therefore, a high density image is obtained.

  In summary, in Examples 1 to 3, it was found that a liquid developer containing toner particles having excellent redispersibility, heat-resistant storage stability and chargeability can be provided.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  11 Aluminum vapor deposition PET, 12 Liquid developer, 13 Metal roller, 14 Constant current source, 15 Charger, 16 Surface potential meter, 17 Oscilloscope.

Claims (6)

A liquid developer in which toner particles are dispersed in an insulating liquid,
The toner particles have a core-shell structure in which the first particles containing the first resin are attached to or coated on the surfaces of the second particles containing the second resin, and the second resin contains a polyester resin,
The second resin melts at a lower temperature than the first resin,
A liquid developer in which an alcohol of 30 ppm or more and 300 ppm or less is dissolved in the insulating liquid with respect to a solid content of the toner particles.   The liquid developer according to claim 1, wherein the glass transition point of the first resin is 50 ° C. or higher.   The liquid developer according to claim 1, wherein the alcohol is ethanol or isopropanol. A method for producing a liquid developer in which toner particles are dispersed in an insulating liquid,
Preparing a dispersion of first particles in which first particles containing a first resin are dispersed in the insulating liquid;
Preparing a second resin-forming solution in which a second resin containing a polyester resin is dissolved in an organic solvent;
Resin particles having a core / shell structure obtained by mixing the dispersion of the first particles and the second resin-forming solution and attaching or coating the first particles on the surfaces of the second particles containing the second resin. Obtaining a dispersion of
Distilling off the organic solvent from the dispersion of resin particles having the core-shell structure;
By adding alcohol to the dispersion of the resin particles having the core / shell structure from which the organic solvent has been distilled off, a liquid developer in which the toner particles having the core / shell structure are dispersed in the insulating liquid is obtained. And having a process
The second resin melts at a lower temperature than the first resin,
The method for producing a liquid developer, wherein the insulating liquid contains 30 ppm or more and 300 ppm or less of alcohol dissolved in the solid content of the toner particles.   The method for producing a liquid developer according to claim 4, wherein the glass transition point of the first resin is 50 ° C. or higher.   The method for producing a liquid developer according to claim 4, wherein the alcohol is ethanol or isopropanol.

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