JP2592320B2 - Liquid developer for electrostatic photography - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a liquid developer for electrostatography comprising at least a resin dispersed in a carrier liquid having an electric resistance of not less than 10 ⁹ Ωcm and a dielectric constant of not more than 3.5. In particular, the present invention relates to a liquid developer having excellent redispersibility, storage stability, stability, image reproducibility, and fixability.

(Prior Art) A general liquid developer for electrophotography is a petroleum-based resin such as an organic or inorganic pigment or dye such as carbon black, nigrosine or phthalocyanine blue and a natural or synthetic resin such as alkyd resin, acrylic resin, rosin or synthetic rubber. Dispersed in a liquid with high insulation and low dielectric constant such as aliphatic hydrocarbons, and added with a polarity controlling agent such as a polymer containing metal soap, lecithin, linseed oil, higher fatty acid, and vinylpyrrolidone. .

In such a developer, the resin is dispersed in the form of particles having a diameter of several nm to several hundred nm as insoluble latex particles,
In the conventional liquid developer, the soluble dispersion stabilizing resin and the soluble dispersion stabilizing resin due to insufficient bonding between the polarity controlling agent and the insoluble latex particles and the polarity controlling agent were in a state of being easily diffused into the solution. For this reason, there has been a drawback that the soluble dispersion stabilizing resin is detached from the insoluble latex particles due to long-term storage or repeated use, and the particles settle, aggregate, accumulate, and the polarity becomes unclear. Also, once aggregated,
The deposited particles are difficult to re-disperse, so that the particles remain attached to the developing device everywhere, leading to failure of the developing device such as contamination of an image area and clogging of a liquid feeding pump.

In order to improve these drawbacks, a means for chemically bonding a soluble dispersion stabilizing resin and insoluble latex particles has been devised, and is disclosed in US Pat. No. 3,990,980.
However, the dispersion stability of these liquid developers against spontaneous sedimentation of particles has been improved to some extent, but it is still insufficient, and when used in an actual developing device, the toner adhered to each part of the device becomes a coating film. In addition, it is difficult to re-disperse, and furthermore, it is not sufficient for re-dispersion stability which can be used practically, for example, it causes a failure of the apparatus, stains of a copied image, and the like. Further, in the method for producing resin particles described above, in order to produce monodisperse particles having a narrow particle size distribution, there is a remarkable restriction on the combination of a dispersion stabilizer that acts and a monomer that is insolubilized, and the coarse particles are generally coarse. Particles having a large particle size distribution containing a large amount of particles or polydisperse particles having two or more average particle diameters were obtained. In addition, it was difficult to obtain a desired average particle size with monodisperse particles having a narrow particle size distribution, and large particles of 1 μm or more or very fine particles of 0.1 μm or less were formed. Further, there is a problem that the dispersion stabilizer to be used must be produced through a complicated and time-consuming production process.

Further, in order to improve the above-mentioned drawbacks, insoluble dispersible resin particles of a copolymer of a monomer to be insolubilized and a monomer containing a long-chain alkyl moiety or a monomer containing two or more kinds of polar components. The method of improving the degree of dispersion of the particles, the degree of redispersion, and the storage stability is described in JP-A-60-179951 and JP-A-62-15.
It is disclosed in 1868 and the like.

(Problems to be Solved by the Invention) On the other hand, in recent years, a method of printing a large number of 5,000 or more sheets using a master plate for offset printing by an electrophotographic method has been attempted. It has become possible to print 10,000 sheets or more in plate size. Further, the operation time of the electrophotographic plate making system has been shortened, and improvement in speeding up the development-fixing process has been performed.

Dispersed resin particles produced according to the means disclosed in JP-A-60-179951 and JP-A-62-151868, when the developing speed is increased, the dispersibility of the particles, in terms of redispersibility, also fixed. In the case where the time was shortened or in the case of a large plate size (for example, A-3 size or more) master plate, the performance was not always satisfactory in terms of printing durability.

The present invention solves the problems of the conventional liquid developer as described above.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid developer which has a fast development-fixing process and has excellent dispersion stability, re-dispersibility and fixability even in an electrophotographic plate making system using a large-size master plate. That is.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid developer capable of producing an offset printing master having excellent oil sensitivity and printing durability by electrophotography.

Another object of the present invention is to provide a liquid developer suitable for various kinds of electrophotography and various kinds of transfer in addition to the above-mentioned applications.

Still another object of the present invention is to provide a liquid developer that can be used in any system where a liquid developer can be used, such as ink jet recording, cathode ray tube recording, and recording of various change processes such as pressure change or electrostatic change. That is.

(Means for Solving the Problems) An object of the present invention is to provide a liquid developer for electrostatography comprising at least a resin dispersed in a non-aqueous medium having an electric resistance of 10 ⁹ Ωcm or more and a dielectric constant of 3.5 or less. In the above, the dispersed resin particles are a polymer containing at least a repeating unit represented by the following general formula (I), a part of which is crosslinked, and a monofunctional polymer is provided only at one end of at least one polymer main chain. Is soluble in a non-aqueous solvent in the presence of a dispersion stabilizing resin soluble in the non-aqueous solvent, which is formed by bonding a polymerizable double bond group copolymerizable with the water-soluble monomer (A). A monofunctional monomer (A) which is insolubilized by the following general formula (II):
Having a number-average molecular weight of 10 ⁴ or less, wherein a polymerizable double bond group represented by the following general formula (III) is bonded to only one end of the main chain of a polymer comprising a repeating unit represented by This is achieved by a liquid developer for electrophotography, which is a copolymer resin particle obtained by polymerizing a solution containing at least one macromonomer (B).

General formula (I) In the general formula (I), X ¹ represents —COO—, —OCO—, —CH ₂ OCO
—, —CH ₂ COO—, —O—, or —SO ₂ —.

R ¹ represents a hydrocarbon group having 6 to 32 carbon atoms.

a ¹ and a ² may be the same or different from each other, and each represents a hydrogen atom, a halogen atom, a cyano group, a hydrocarbon group having 1 to 8 carbon atoms, -COO-R ² or a hydrocarbon group having 1 to 8 carbon atoms. Represents —COO—R ² (R ² represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms).

General formula (II) General formula (III) In the general formula (II), Y ¹ represents —COO—, —OCO—, —CH ₂ OCO
_{-, - CH 2 COO -,} - O -, - SO 2 -, (R ⁴ represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms).

R ³ represents a hydrocarbon group having 1 to 22 carbon atoms.

b ¹ and b ² may be the same or different from each other, and each represents a hydrogen atom, a halogen atom, a cyano group, a hydrocarbon group having 1 to 8 carbon atoms, -COO-R ⁵ or a hydrocarbon group having 1 to 8 carbon atoms. Represents a group represented by —COO—R ⁵ (R ⁵ represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms).

In formula (III), Y ² has the same meaning as Y ¹ in formula (II). d ¹ and d ² may be the same or different from each other, and have the same meaning as b ¹ or b ² in the general formula (II), respectively.

 Hereinafter, the liquid developer of the present invention will be described in detail.

The electric resistance used in the present invention is 10 ⁹ Ωcm or more, and the dielectric constant is 3.5.
The following carrier liquids are preferably straight-chain or branched aliphatic hydrocarbons, alicyclic hydrocarbons or aromatic hydrocarbons,
And these halogen-substituted compounds can be used. For example, octane, isooctane, decane, isodecane, decalin, nonane, dodecane, isododecane, cyclohexane, cyclooctane, cyclodecane, benzene, toluene, xylene, mesitylene, isoper E, isoper G, isoper H, isoper L (Isoper; a product of Exxon) Name), Shersol 70, Shersol 71 (Shersol; trade name of Shell Oil Company), AMSCO OM
S, Amsco 460 solvent (Amsco; trade name of Spirits) or the like is used alone or in combination.

Non-aqueous dispersion resin particles, which are the most important components in the present invention (hereinafter sometimes referred to as latex particles)
Is a polymer containing at least a repeating unit represented by the general formula (I) in a non-aqueous solvent, a part of which is cross-linked, and monofunctional at only one terminal of at least one polymer main chain. The monofunctional monomer (A) and the monofunctional monomer (A) in the presence of a dispersion stabilizing resin soluble in the non-aqueous solvent, which is formed by bonding a polymerizable double bond group copolymerizable with the monomer (A). Copolymerizing with the reactive macromonomer (B) (so-called polymerization granulation method)
It is manufactured by.

Here, as the non-aqueous solvent, basically, any solvent that is miscible with the carrier liquid of the liquid developer for electrostatography can be used.

That is, the solvent used for producing the dispersed resin particles may be any solvent that is miscible with the carrier liquid, and is preferably a linear or branched aliphatic hydrocarbon, alicyclic hydrocarbon, or aromatic hydrocarbon. Hydrogen and halogen-substituted products thereof are exemplified. For example, hexane, octane, isooctane, decane, isodecane, decalin, nonane, dodecane, isododecane, isopaffin petroleum solvents such as Isopar E, Isopar G, Isopar H, Isopar L, Shersol 70, Shersol 71, Amsco OM
S, Amsco 460, solvents, etc. are used alone or as a mixture.

Solvents that can be used in combination with these organic solvents include alcohols (eg, methyl alcohol,
Ethyl alcohol, propyl alcohol, butyl alcohol, fluorinated alcohol, etc., ketones (eg, acetone, methyl ethyl ketone, cyclohexanone, etc.), carboxylic esters (eg, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate) ,
Ethyl propionate, etc.), ethers (eg, diethyl ether, dipropyl ether, tetrahydrofuran, dioxane, etc.), halogenated hydrocarbons (eg,
Methylene dichloride, chloroform, carbon tetrachloride, dichloroethane, methyl chloroform, etc.).

The non-aqueous solvent used by mixing these, after polymerization granulation,
It is desirable to evaporate under heating or under reduced pressure.However, as a latex particle dispersion, even if brought into the liquid carrier, there is a problem as long as the liquid resistance of the developer can satisfy the condition of 10 ⁹ Ωcm or more. No.

Usually, it is preferable to use the same solvent as the carrier liquid at the stage of producing the resin dispersion. As described above, linear or branched aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, halogenated Hydrocarbons and the like.

The present invention is used for forming a stable resin dispersion from a solvent-insoluble copolymer formed by copolymerizing a monofunctional monomer (A) and a macromonomer (B) in a non-aqueous solvent. Is a polymer containing at least a repeating unit represented by the general formula (I), a part of which is cross-linked, and the monomer having only one monomer at only one end of at least one polymer main chain. It is characterized by being a resin soluble in the non-aqueous solvent formed by bonding a polymerizable double bond group capable of copolymerizing with the compound (A).

 Hereinafter, the dispersion stabilizing resin will be described in detail.

In the general formula (I) represented as a repeating unit of the polymer component, the hydrocarbon group may be substituted.

In the general formula (I), X ¹ is preferably -COO-, -O
_{CO -, - CH 2 OCO -} , - represents a CH ₂ COO-.

R ¹ preferably represents a hydrocarbon group having 8 to 22 carbon atoms,
Specifically, octyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group, hexadecyl group, octadecyl group, docosanyl group, eicosanyl group, octenyl group,
Aliphatic groups such as a decenyl group, a dodecenyl group, a tridecenyl group, a tetradecenyl group, a hexadecenyl group, an octadecenyl group, and a docosenyl group.

a ¹ and a ² may be the same or different from each other, and are preferably a hydrogen atom, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, etc.), a cyano group, and a carbon number of 1 to 6;
Hydrocarbon group (e.g., methyl group, ethyl group, propyl group, butyl group, phenyl group, etc.), - represents a COO-R ² or -COO-R ² via a hydrocarbon group having 1 to 6 carbon atoms. Here, R ² is a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms (eg, methyl, ethyl, propyl, butyl, hexyl, octyl, decyl, dodecyl, tridecyl, tetradecyl) , Hexadecyl, octadecyl, butenyl, hexenyl, octenyl, decenyl, benzyl, phenethyl, phenyl, chlorobenzyl, bromobenzyl, methylbenzyl, chlorophenyl, bromophenyl, tolyl, etc. ). More preferably, one of a ¹ and a ² is a hydrogen atom.

As the repeating unit of the polymer main chain of the present invention, a repeating unit other than the unit represented by the general formula (I) may be contained.

As a repeating unit other than the general formula (I), for example,
Any monofunctional monomer copolymerizable with the monomer corresponding to the repeating unit represented by the general formula (I) may be used.

Specific examples include a repeating unit represented by the general formula (IV).

General formula (IV) In the formula (IV), T ¹ represents —COO—, —OCO—, —CH ₂ OCO—,
_{CH 2 COO -, - SO 2} -, - O -, - S-, _{-NHCO -, - CH 2 NHCO -} , - NHSO 2 -, - CH 2 NHSO 2 -, -
_{CONNHCOO -, - CONHSO 2 -,} - NHCONH-, And the like.

W ¹ represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms which may be substituted (for example, methyl group, ethyl group, propyl group, butyl group, hexyl group, octyl group, decyl group,
Dodecyl group, tridecyl group, octadecyl group, 2-hydroxyethyl group, 3-hydroxypropyl group, 2-chloroethyl group, 2-cyanoethyl group, 2-methoxycarboniethyl group, 2-carboxyethyl group, butenyl group, hexenyl group Octenyl, cyclohexyl, benzyl, phenethyl, phenyl, tolyl, naphthyl, chlorophenyl, bromophenyl, methoxyphenyl, bromobenzyl, methylbenzyl, methoxybenzyl, etc.).

W ² represents a hydrogen atom, a halogen atom (eg, a fluorine atom, a chlorine atom, a medium atom, etc.), an alkyl group (eg, a methyl group, an ethyl group, a propyl group, a chloromethyl group, a hydroxymethyl group, an N, N-dimethylamino Methyl group, N, N-diethylaminomethyl group), hydroxy group, carboxyl group or sulfo group. n represents an integer of 1 to 4.

Z ¹ represents a linking group or a bond connecting the benzene ring to R ⁶ , -COO-, -CH ₂ O-, -O-, -S-, And a direct bond between a benzene ring and R ⁶ (W ³ is
It represents a W ¹ same content and).

R ⁶ is a hydrogen atom, an unsubstituted hydrocarbon group having 1 to 6 carbon atoms (e.g., methyl, ethyl, propyl, butyl, heptyl, hexyl, cycloheptyl,
A cyclohexyl group, a hexenyl group, a phenyl group, etc.), a substituted aliphatic group having 1 to 22 carbon atoms [as a substituent, for example, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), -OH, _{-SH, -COOH, -SO 3 H,} -SO
_{2 H, -PO 3 H 2,} -CN, -CONH 2, -SO 2 NH 2, (W ⁴ and W ⁵ each represent the same contents as W ¹ ), -OCO
W ⁶ , -O-W ⁶ , -S-W ⁶ , —COOW ⁶ , —SO ₂ W ⁶ (W ⁶ , W ⁷ and W ⁸ each represent an optionally substituted hydrocarbon group having 1 to 18 carbon atoms;
W ¹ and the same meaning), etc.], a Hajime Tamaki (e.g. a thiophene ring, a pyran ring, a furan ring, a pyridine ring, a morpholine ring, piperidine ring, an imidazole ring, a benzimidazole ring, Chiazororu ring), or substituted Aromatic groups (eg, phenyl, naphthyl, tolyl, xylyl, mesityl, fluorophenyl, chlorophenyl, bromophenyl, dichlorophenyl, dibromophenyl, trifluoromethylphenyl, hydroxyphenyl) A methoxyphenyl group, a carboxyphenyl group, a sulfophenyl group, a carboxamidophenyl group, a sulfamidophenyl group, a methoxycarbonylphenyl group, an acetamidophenyl group, a cyanophenyl group,
Nitrophenyl group, methanesulfonylphenyl group, etc.).

e ¹ and e ² may be the same or different from each other, and each represents the same content as a ¹ or a ² in the general formula (I).

Further, a monomer other than the monomer corresponding to the repeating unit represented by the above general formula (IV) may be used. For example, maleic acid, maleic anhydride, itaconic anhydride, vinylnaphthalenes, Examples include vinyl heterocyclic compounds in which a vinyl group is directly substituted on a ring (for example, vinylpyridine, vinylimidazole, vinylthiophene, vinylpyrrolidone, vinylbenzimidazole, vinyltriazole, and the like).

The dispersion stabilizing resin of the present invention comprises a polymer component selected from the repeating units represented by the general formula (I) as a homopolymer component or a repeating unit represented by the general formula (I). A copolymer obtained by copolymerization with another monomer copolymerizable with the monomer corresponding to the unit (for example, a monomer corresponding to the repeating unit represented by the general formula (IV)). It is a polymer which is contained as a united component and partially crosslinked, and further has a polymerizable double bond group bonded to only one end of at least one of the polymer main chains.

The dispersion stabilizing resin of the present invention is a monomer corresponding to the repeating unit represented by the general formula (I) and another monomer copolymerizable with the monomer (for example, a compound represented by the general formula (IV)) And the like, a monomer corresponding to the repeating unit represented by the general formula (I) The amount is 30 parts by weight or more, preferably 50 parts by weight or more, more preferably 70 parts by weight or more based on 100 parts by weight.

As a method for introducing a crosslinked structure into the polymer, a generally known method can be used. That is, in the polymerization reaction of the monomers, there are a method of polymerizing in the presence of a polyfunctional monomer and a method of cross-linking the polymer by a polymer reaction containing a functional group that progresses a cross-linking reaction. Preferably, a method of crosslinking between polymer chains by polymerizing a monomer having two or more polymerizable functional groups together with a monomer corresponding to the above general formula (I) is preferable.

Specifically, as the polymerizable functional group, CH ₂ CHCH—, CH ₂ CHCH
−CH ₂ −, CH ₂ = CH-CONH-, CH ₂ = CH-CONHCOO-, _{CH 2 = CH-NHCO-, CH} 2 = CH-CH 2 -NHCO-, CH 2 = CH-SO
_2- , CH ₂ CHCH—CO—, CH ₂ CHCH—O—, CH ₂ CHCH—S— and the like can be mentioned, and the monomer having two or more polymerizable functionalities is A monomer having two or more of the same or different polymerizable functional groups may be used.

Specific examples of the monomer having two or more polymerizable functional groups include, for example, as monomers having the same polymerizable functional group, styrene derivatives such as divinylbenzene and trivinylbenzene;
Polyhydric alcohols (eg, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol # 200, # 400, # 600, 1,3-butylene glycol, neopentyl glycol, dipropylene glycol, polypropylene glycol, trimethylolpropane, trimethylol Methacrylic acid, acrylic acid or crotonic acid esters, vinyl ethers or allyl ethers of ethane, pentaerythritol, etc. or polyhydroxyphenols (eg, hydroquinone, resorcin, catechol and derivatives thereof); dibasic acids (eg, Vinyl esters, allyl esters, vinyl amides or allyl amides of malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, phthalic acid, itaconic acid, etc.) Condensation of polyamines (eg, ethylenediamine, 1,3-propylenediamine, 1,4-butylenediamine, etc.) with carboxylic acids containing vinyl, etc. (eg, methacrylic acid, acrylic acid, crotonic acid, allylacetic acid, etc.) Body and the like.

Further, as a monomer having a different polymer functional group, for example, a carboxylic acid containing a vinyl group (for example, methacrylic acid, acrylic acid, methacryloyl acetic acid, acryloyl acetic acid, methacryloyl propionic acid, acryloyl propionic acid, itaconiloyl acetic acid, itaco Niroylpropionic acid, a reactant of a carboxylic anhydride and an alcohol or amine (eg, allyloxycarbonylpropionic acid,
Allyloxycarbonylacetic acid, 2-allyloxycarbonylbenzoic acid, allylaminocarbonylpropionic acid, etc.) or ester derivatives or amide derivatives containing a vinyl group (for example, vinyl methacrylate, vinyl acrylate, vinyl itaconate, methacrylic acid) Allyl, allyl acrylate, allyl itaconate, vinyl methacryloyl acetate, vinyl methacryloyl propionate, allyl methacryloyl propionate, vinyl oxycarbonyl methyl methacrylate, vinyl oxy carbonyl methyl oxy carbonyl ethylene acrylate, N-
Allyl acrylamide, N-allyl methacrylamide,
Containing N-allylitaconamide, allylamide methacryloylpropionate); or amino alcohols (eg, aminoethanol, 1-aminopropanol, 1-aminobutanol, 1-aminohexanol, 2-aminobutanol, etc.) and a vinyl group And a condensate with a carboxylic acid.

In the present invention, a partially crosslinked resin is formed by polymerizing a monomer having two or more polymerizable functional groups using 15% by weight or less, preferably 10% by weight or less of all monomers. can do.

Further, the polymerizable double bond group bonded only to one terminal of the polymer main chain has a chemical structure bonded directly to one terminal of the polymer main chain or bonded via an arbitrary linking group.

Specifically, for example, a chemical structure represented by the general formula (V) is given.

General formula (V) Wherein (V), T ² represents T ¹ same contents as in the general formula (IV).

f ¹ and f ² may be the same or different from each other, and each represents the same content as e ¹ or e ² in the general formula (IV).

Q ¹ is Represents a bond directly linking to one end of the polymer main chain, or a linking group via an arbitrary linking group.

Examples of the bonding group include a carbon-carbon bond (single bond or double bond), a carbon-heteroatom bond (for example, an oxygen atom, a sulfur atom, a nitrogen atom, and a silicon atom), and a heteroatom-heteroatom bond. It is composed of any combination of atomic groups. For example, [Z ² and Z ³ are each a hydrogen atom, a halogen atom (eg, a fluorine atom, a chlorine atom, a bromine atom, etc.), a cyano group, a hydroxyl group, an alkyl group (eg, a methyl group, an ethyl group,
Propyl group etc.), CH = CH, -O-, -S-, -COO -, - SO ₂ -, -NHCOO-, -NHCONH-, [Z ⁴ and Z ⁵ are each a hydrogen atom, a hydrocarbon group having 1 to 8 carbon atoms (eg, methyl, ethyl, propyl, butyl, pentyl, hexyl, benzyl, phenethyl, phenyl) , Tolyl group, etc.] or -OZ ⁶ (Z ⁶ is Z ⁴
Represents the same content as the hydrocarbon group in the above)).

The polymerizable double bond group represented by the general formula (V) that binds to only one terminal of the polymer main chain as described above is specifically described below. However, in the following specific examples, A is-
H, —CH ₃ or —CH ₂ COOH ₃ , and B represents —H or —CH ₃
Represents N represents an integer of 2 to 10, m represents 2 or 3, l represents 1, 2 or 3, and p represents 1 to 4.
And q represents 1 or 2.

(1) CH ₂ = CH-COO-, _{(4) CH 2 = CH-} CH 2 COO-, (5) CH 2 = CH-OCO -, (6) CH 2 = CH-CH 2 OCO
−, _{(19) CH 2 = CH-} CH 2 COO (CH 2 n S-, _{(24) CH 2 = CH-} OCO (CH 2 l S-, (25) CH 2 = CH-CH 2 -OCO- (CH 2 l S-, The dispersion stabilizing resin of the present invention comprising a polymerizable double bond group bonded to only one terminal of the polymer main chain has various double bonds at the terminal of a living polymer obtained by conventionally known anionic or cationic polymerization. Reacting a reagent containing a group, or adding a “specific reactive group” (eg, —OH, —COOH, —SO ₃ H, —N
_{H 2, -SH, -PO 3 H} 2, -NCO, -NCS, -COCl, was reacted a reagent containing -SO ₂ Cl, etc.),
A method of introducing a polymerizable double bond group by a polymer reaction (method by an ionic polymerization method) or a radical using a polymerization initiator and / or a chain transfer agent containing the above “specific reactive group” in the molecule. After polymerization, the polymer is easily polymerized using a "specific reactive group" bonded only to one end of the polymer main chain to introduce a polymerizable double bond group. Can be manufactured.

Specifically, P.Dreyfuss & RPQuirk, Encycl.Poly
m.Sci.Eng., 7 , 551 (1987), Yoshiki Chujo, Yuya Yamashita, "Dyes and Drugs", 30 , 232 (1984), Akira Ueda, Susumu Nagai, "Science and Industry", 60 , 57 (1986), PFRempp & E.Franta, Advan
ces in Polymer Science, 58 , 1 (1984), Koichi Ito "Polymer Processing", 35 , 262 (1986), V. Percec, Appplied Poly
A polymerizable double bond group can be introduced according to a method described in a review such as mer Sciene, 285 , 97 (1984) and the literature cited therein.

More specifically, at least one monomer corresponding to the repeating unit represented by the general formula (I), a polyfunctional monomer for introducing the above-mentioned crosslinked structure, and the above-mentioned “ A mixture of a chain transfer agent containing a specific reactive group "is used as a polymerization initiator (eg, azobis compound, peroxide, etc.)
Or a method of polymerizing using a polymerization initiator containing the above-mentioned "specific reactive group" in the molecule without using the above-mentioned chain transfer agent, or any of a chain transfer agent and a polymerization initiator Also, a polymer having a cross-linked structure by a method using a compound containing the above “specific reactive group” in the molecule, and having a “specific reactive group” bonded to only one terminal of the polymer main chain Are synthesized. Next, there is a method in which a polymerizable double bond is introduced by performing a polymer reaction using the “specific reactive group”.

As the chain transfer agent to be used, for example, the “specific reactive group” or a mercapto compound containing a substituent derivable to the “specific reactive group” {eg, thioglycolic acid, thiomalic acid, thiosalicylic acid, -Mercaptopropionic acid, 3-mercaptopropionic acid, 3-mercaptobutyric acid, N- (2-mercaptopropionyl) glycine, 2-mercaptonicotinic acid, 3- [N- (2-mercaptoethyl) carbamoyl] propionic acid, 3- [N
-(2-Mercaptoethyl) amino] propionic acid, N
-(3-mercaptopropionyl) alanine, 2-mercaptoethanesulfonic acid, 3-mercaptopropanesulfonic acid, 4-mercaptobutanesulfonic acid, 2-mercaptoethanol, 1-mercapto-2-propanol,
3-mercapto-2-butanol, mercaptophenol, 2-mercaptoethylamine, 2-mercaptoimidazole, 2-mercapto-3-pyridinol, etc., or the “specific reactive group” or the “specific reactive group” Examples thereof include iodized alkyl compounds containing a derivable substituent (for example, iodoacetic acid, iodopropionic acid, 3-iodoethanol, 2-iodoethanesulfonic acid, and 3-iodopropanesulfonic acid). Preferably, a mercapto compound is used.

Further, examples of the polymerization initiator containing a substituent which can be derived to “specific reactive group” or “specific reactive group” include, for example, 4,4′-azobis (4-cyanovaleric acid),
4,4'-azobis (4-cyanovaleric chloride), 2,
2'-azobis (2-cyanopropanol), 2,2'-azobis (2-cyanopentanol), 2,2'-azobis [2- (5-hydroxy-3,4,5,6-tetrahydropyrimidine- 2-yl) propane], 2,2'-azobis ｛2
-Methyl-N- [1,1-bis (hydroxymethyl) -2
-Hydroxyethyl] propioamide}, 2,2'-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) ethyl] propioamide}, 2,2'-azobis [2
-Methyl-N- (2-hydroxyethyl) -propioamide], 2,2'-azobis (2-amidinopropane) and the like.

The amount of these chain transfer agents or polymerization initiators used is
The amount is 0.5 to 15 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the total monomers.

The dispersion stabilizing resin of the present invention is soluble in an organic solvent, and specifically, is one in which at least 5 parts by weight or more of the dispersion stabilizing resin is dissolved at a temperature of 25 ° C. with respect to 100 parts by weight of a toluene solvent. I just need.

The weight average molecular weight of the dispersion stabilizing resin of the present invention is 1 × 10
^{It is 4} to 1 × 10 ⁶ , preferably 3 × 10 ^{4 to} 5 × 10 ⁵ .

Monomers used in producing the non-aqueous dispersion resin,
Distinguishing between a monofunctional monomer (A) which is soluble in the non-aqueous solvent but is insolubilized by polymerization, and a monofunctional macromonomer (B) which is copolymerized with the monomer (A). Can be.

The monomer (A) in the present invention may be any monofunctional monomer which is soluble in a non-aqueous solvent but insolubilized by polymerization. Specifically, for example, a monomer represented by the general formula (VI) can be mentioned.

General formula (VI) In the general formula (VI), V is -COO -, - OCO -, - CH 2 OCO
_{-, - CH 2 COO -,} - O-, Express. Here, R ⁸ is a hydrogen atom or an aliphatic group having 1 to 18 carbon atoms which may be substituted (for example, a methyl group, an ethyl group, a propyl group, a butyl group, a 2-chloroethyl group, a 2-chloroethyl group).
Bromoethyl group, 2-cyanoethyl group, 2-hydroxyethyl group, benzyl group, chlorobenzyl group, methylbenzyl group, methoxybenzyl group, phenethyl group, 3-phenylpropyl group, dimethylbenzyl group, fluorobenzyl group, 2-methoxyethyl A 3-methoxypropyl group).

R ⁷ is a hydrogen atom or an optionally substituted aliphatic group having 1 to 6 carbon atoms (e.g., methyl, ethyl, propyl, butyl, 2-chloroethyl, 2,2-dichloroethyl, 2, 2,2-trifluoroethyl group, 2-bromoethyl group, 2-glycidylethyl group, 2-hydroxyethyl group, 2-hydroxypropyl, 2,3-dihydroxypropyl group, 2-hydroxy-3-chloropropyl group, 2 −
Cyanoethyl group, 3-cyanopropyl group, 2-nitroethyl group, 2-methoxyethyl group, 2-methanesulfonylethyl group, 2-ethoxyethyl group, N, N-dimethylaminoethyl group, N, N-diethylaminoethyl group, Trimethoxysilylpropyl group, 3-bromopropyl group, 4-hydroxybutyl group, 2-furfurylethyl group, 2-thienylethyl group, 2-pyridylethyl group, 2-morpholinoethyl group, 2-carboxyethyl group, 3 -Carboxypropyl group, 4-carboxybutyl group, 2-phosphoethyl group, 3-sulfopropyl group, 4-sulfobutyl group, 2-
Carboxamidoethyl group, 3-sulfoamidopropyl group, 2-N-methylcarboxamidoethyl group, cyclopentyl group, chlorocyclohexyl group, dichlorohexyl group, etc.).

g ¹ and g ² may be the same or different from each other, and have the same meanings as b ^{1 and} b ² in the general formula (II), respectively.

Specific monofunctional monomers (A) include, for example, aliphatic carboxylic acids having 1 to 6 carbon atoms (acetic acid, propionic acid,
Vinyl esters or allyl esters of butyric acid, monochloroacetic acid, trifluoropropionic acid, etc .; substituted with 1 to 4 carbon atoms of unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid and maleic acid. Alkyl esters or amides (for example, as an alkyl group, a methyl group, an ethyl group, a propyl group, a butyl group,
2-chloroethyl group, 2-bromoethyl group, 2-fluoroethyl, trifluoroethyl group, 2-hydroxyethyl group, 2-cyanoethyl group, 2-nitroethyl group, 2-methoxyethyl group, 2-methanesulfonylethyl group, 2-
Benzenesulfonylethyl group, 2- (N, N-dimethylamino) ethyl group, 2- (N, N-diethylamino) ethyl group, 2-carboxyethyl group, 2-phosphoethyl group, 4
-Carboxybutyl group, 3-sulfopropyl group, 4-sulfobutyl group, 3-chloropropyl group, 2-hydroxy-3-chloropropyl group, 2-furfurylethyl group, 2
-Pyridinylethyl group, 2-thienylethyl group, trimethoxysilylpropyl group, 2-carboxamidoethyl group, etc .; styrene derivatives (for example, styrene, vinyltoluene, α-methylstyrene, vinylnaphthalene, chlorostyrene, dichlorostyrene, bromo Styrene, vinylbenzene carboxylic acid, vinylbenzene sulfonic acid, chloromethylstyrene, hydroxymethylstyrene, methoxymethylstyrene, N, N-dimethylaminomethylstyrene, vinylbenzenecarboxamide, vinylbenzenesulfonamide, etc.); acrylic acid, methacrylic acid Unsaturated carboxylic acids such as, crotonic acid, maleic acid, itaconic acid;
Maleic acid, cyclic anhydride of itaconic acid; acrylonitrile; methacrylonitrile; a heterocyclic compound containing a polymer double bond group (specifically, for example, “Polymer Data Hamba Book-Basic- Pp.157-184, Baifukan (1986), for example, N-vinylpyridine, N-vinylimidazole, N-vinylpyrrolidone, vinylthiophene, vinyltetrahydrofuran, vinyloxazoline, vinylthiazole, N-vinylmorpholine Etc.).

 Two or more monofunctional monomers (A) may be used in combination.

Next, the monofunctional macromonomer (B) used in the present invention will be further described.

The monofunctional macromonomer (B) can be copolymerized with the monomer (A) only at one terminal of the main chain of the polymer comprising the repeating unit represented by the general formula (II). ) Is a macromonomer having a number average molecular weight of 10 ⁴ or less formed by bonding a polymerizable double bond group.

In the general formulas (II) and (III), b ¹ , b ² , Y ¹ , R ³ , d
^1, the hydrocarbon group contained in the d ² and Y ² have each indicated number of carbon atoms (as unsubstituted hydrocarbon group), these hydrocarbon groups may be substituted.

In the general formula (II), R ⁴ in the substituent represented by Y ¹ is a hydrogen atom, and a preferred hydrocarbon group is an alkyl group having 1 to 18 carbon atoms which may be substituted (for example, a methyl group, Ethyl, propyl, butyl, heptyl, hexyl, octyl, decyl, dodecyl, hexadecyl, octadecyl, 2-chloroethyl, 2-chloroethyl
A bromoethyl group, a 2-cyanoethyl group, a 2-methoxycarbonylethyl group, a 2-methoxyethyl group, a 3-bromopropyl group or the like; an alkenyl group having 4 to 18 carbon atoms which may be substituted (for example, 2-methyl-1); -Propenyl group, 2
-Butenyl group, 2-pentenyl group, 3-methyl-2-pentenyl group, 1-pentenyl group, 1-hexenyl group, 2
-Hexenyl group, 4-methyl-2-hexenyl group, etc.),
An aralkyl group having 7 to 12 carbon atoms which may be substituted (for example, benzyl group, phenethyl group, 3-phenylpropyl group, naphthylmethyl group, 2-naphthylethyl group, chlorobenzyl group, bromobenzyl group, methylbenzyl group, An ethylbenzyl group, a methoxybenzyl group, a dimethylbenzyl group, a dimethoxybenzyl group or the like, an alicyclic group having 5 to 8 carbon atoms which may be substituted (for example, cyclohexyl group,
-Cyclohexylethyl group, 2-cyclopentylethyl group, etc.) or an optionally substituted aromatic group having 6 to 12 carbon atoms (eg, phenyl, naphthyl, tolyl, xylyl, propylphenyl, butylphenyl) Group, octylphenyl group, dodecylphenyl group, methoxyphenyl group, ethoxyphenyl group, butoxyphenyl group, decyloxyphenyl group, chlorophenyl group, dichlorophenyl group, bromophenyl group, cyanophenyl group, acetylphenyl group, methoxycarbonylphenyl group, An ethoxycarbonylphenyl group, a butoxycarbonylphenyl group, an acetamidophenyl group, a propioamidophenyl group, a dodecylylamidophenyl group, etc.).

Y ¹ In the case where is represented, the benzene ring may have a substituent.
Examples of the substituent include a halogen atom (eg, chlorine atom, bromine atom, etc.) and an alkyl group (eg, methyl group, ethyl group, propyl group, butyl group, chloromethyl group, methoxymethyl group, etc.).

R ³ preferably represents a hydrocarbon group having 1 to 18 carbon atoms,
Specifically, representing the same contents as those described for R ⁴ above.

b ¹ and b ² may be the same or different from each other, and are preferably each a hydrogen atom, a halogen atom (eg, a chlorine atom, a bromine atom, etc.), a cyano group, an alkyl group having 1 to 3 carbon atoms (eg, methyl Group, ethyl group, propyl group, etc.),-
COOR ⁵ or -CH ₂ COOR ⁵ (R ⁵ is a hydrogen atom or a carbon atoms 1 to 1
8 represents an alkyl group, an alkenyl group, an aralkyl group, an alicyclic group or an aryl group, which may be substituted, and specifically represents the same contents as those described for R ⁴ ) Express.

In the general formula (III), Y ² has the same meaning as Y ¹ in the general formula (II), d ¹ and d ² may be the same or different, and b ¹ or b in the general formula (II) Synonymous with ² . Preferred ranges of Y ² , d ¹ and d ² are the same as those described for Y ¹ , b ¹ and b ² , respectively.

More preferably, ^one of b ¹ and b ^{2 in} the general formula (II) or d ¹ and b ^{2 in} the general formula (III) is a hydrogen atom.

The macromonomer used in the present invention is, as described above, a polymerizable double bond represented by the general formula (III) only at one end of the polymer main chain composed of the repeating unit represented by the general formula (II) The groups have a chemical structure that is directly bonded or bonded by an arbitrary linking group. The group linking the general formula (II) component and the general formula (III) component includes a carbon-carbon bond (single bond or double bond),
It is composed of any combination of carbon-heteroatom bonds (for example, oxygen atoms, sulfur atoms, nitrogen atoms, silicon atoms, etc.) and heteroatom-heteroatom bonds.

Among the macromonomers (B) of the present invention, preferred are those represented by the general formula (VII).

General formula (VII) In the general formula (VII), b ¹ , b ² , d ¹ , d ² , Y ¹ , R ³ and Y ² are
They represent the same contents as those described in the general formulas (II) and (III), respectively.

Q ² is just a bond or [R ⁹ and R ¹⁰ are each a hydrogen atom, a halogen atom, (eg, a fluorine atom, a chlorine atom, a bromine atom, etc.), a cyano group,
A hydroxyl group, an alkyl group (for example, a methyl group, an ethyl group, a propyl group, etc.)], CH = CH, -O-, -S-, -COO -, - SO ₂ -, -NHCOO-, -NHCONH-, [R ¹¹ and R ¹² each represent a hydrogen atom or a hydrocarbon group having the same content as R ⁴ , etc.], or a single linking group selected from an atomic group such as Represents

The upper limit of the number average molecular weight of the macromonomer (B) is 1 × 10
^If it exceeds ⁴ , printing durability will decrease. On the other hand, if the molecular weight is too small, soiling tends to occur, so it is preferably 1 × 10 ³ or more.

Particularly preferred examples of Y ¹ , R ³ , Y ² , b ¹ , b ² , d ¹ and d ^{2 in} the formulas (II), (III) and (VII) are shown below.

The ^{Y 1 -COO -, - OCO -} , - O -, - CH 2 COO- , or, -CH ₂ OCO-, and examples R ³ is include alkyl or alkenyl at least 18 carbon atoms, Y ^Examples of ² include all of the above (however, R ⁴ is a hydrogen atom), and examples of b ¹ , b ² , d ¹ , and d ² include a hydrogen atom or a methyl group.

The macromonomer (B) of the present invention can be produced by a conventionally known synthesis method. For example, a method by an ionic polymerization method in which various terminals are reacted with a terminal of a living polymer obtained by anionic polymerization or cationic polymerization to form a macromer, and a molecule containing a reactive group such as a carboxyl group, a hydroxy group, or an amino group is contained. A radical polymerization method in which an oligomer having a terminal reactive group bond obtained by radical polymerization is reacted with various reagents using the polymerization initiator and / or chain transfer agent thus obtained to form a macromer, polyaddition or polycondensation A method by a polyaddition condensation method for introducing a polymerizable double bond group into the oligomer obtained by the reaction in the same manner as in the above-mentioned radical polymerization method may be used.

Specifically, P.Dreyfuss & RPQuirk, Encycl.Poly
m.Sci.Eng., 7 , 551 (1987), PFRempp & E.Franta, A
dv.Polym.Sci., 58 , 1 (1984), V.Percec, Appl.Polym.Sc
i., 285 , 95 (1984), R. Asami, M. Takaki, Makvamol. Chem.
Suppl., 12 , 163 (1985), P. Rempp, et.al., Makvamol. Che
m. Suppl., 8 , 3 (1984), Yusuke Kawakami, "Chemical Industry", 38 ,
56 (1987), Yuya Yamashita, “Polymer”, 31 , 988 (1982),
Kobayashi Shiro, “Polymer”, 30 , 625 (1981), Higashimura Toshinobu,
"Journal of the Adhesion Society of Japan", 18 , 536 (1982), Koichi Ito, "Polymer processing", 35 , 262 (1986), used by Takashi, Takashi Tsuda, "Functional Materials", 1987 , No. 10, 5, etc. And the methods described in the references and patents cited therein.

The macromonomer (B) of the present invention more specifically comprises
The following compounds may be mentioned as examples: However, the scope of the present invention is not limited to these.

The dispersion resin of the present invention comprises at least one of each of the monomer (A) and the macromonomer (B). What is important is that the resin synthesized from these monomers is insoluble in the non-aqueous solvent. Thus, a desired dispersion resin can be obtained. More specifically, the macromonomer (B) is preferably used in an amount of 0.1 to 10% by weight, more preferably 0.2 to 5% by weight, based on the insoluble monomer (A). Particularly preferably, it is 0.3 to 3% by weight. The molecular weight of the dispersion resin of the present invention is preferably 10 ³ to 10 ⁶ , and more preferably 10 ^{4 to} 5.
× 10 ^5.

In order to produce the dispersion resin used in the present invention as described above, generally, the dispersion stabilizing resin and the monomer (A) as described above are used.
And the macromonomer (B) may be heated and polymerized in a non-aqueous solvent in the presence of a polymerization initiator such as benzoyl peroxide, azobisisobutyronitrile, and butyllithium.

Specifically, a method of adding a polymerization initiator to a mixed solution of a dispersion stabilizing resin, a monomer (A) and a macromonomer (B), and a method of adding a monomer (A ) And the macromonomer (B) are dropped together with the polymerization initiator, or the polymerization is carried out in a mixed solution containing the whole amount of the dispersion stabilizing resin and a part of the mixture of the monomer (A) and the macromonomer (B). A method in which a mixture of the remaining monomer (A) and the macromonomer (B) is optionally added together with the initiator, and further a dispersion stabilizing resin and the monomer (A) and the macromonomer ( There is a method of arbitrarily adding the mixed solution of B) together with the polymerization initiator, and any method can be used for the production.

The total amount of the monomer (A) and the macromonomer (B) is about 5 to 80 parts by weight, preferably 10 to 50 parts by weight, based on 100 parts by weight of the non-aqueous solvent.

The amount of the soluble dispersion stabilizing resin as a dispersion stabilizer is 1 to 100 parts by weight, preferably 5 to 50 parts by weight, based on 100 parts by weight of all the monomers used above.

The amount of the polymerization initiator is suitably from 0.1 to 5% by weight of the total monomers.

The polymerization temperature is about 50 to 180 ° C., preferably 60 to 180 ° C.
~ 120 ° C. The reaction time is preferably 1 to 15 hours.

In the non-aqueous solvent used for the reaction, the alcohols described above,
When polar solvents such as ketones, ethers and esters are used in combination, or when the unreacted product of the monomer (A) to be polymerized and granulated remains, the boiling point of the solvent or monomer is increased. It is preferable to remove by heating or distilling off under reduced pressure.

As described above, the non-aqueous dispersion resin produced according to the present invention exhibits very stable dispersibility at the same time as being present as fine particles having uniform particle size distribution, and can be used repeatedly for a long time especially in a developing device. However, even if the dispersibility is good and the developing speed is improved, re-dispersion is easy, and it is not recognized at all that adhesion of each part of the apparatus is caused.

Further, when fixed by heating or the like, a strong film was formed, and excellent fixability was exhibited.

Further, the liquid developer of the present invention has a rapid development-fixing process and is excellent in dispersion stability, re-dispersibility and fixability even when a large-size master plate is used.

If desired, a colorant may be used in the liquid developer of the present invention. The colorant is not particularly limited, and various conventionally known pigments or dyes can be used.

In the case of coloring the dispersion resin itself, for example, as one of the coloring methods, there is a method of physically dispersing the dispersion resin in a dispersion resin using a pigment or a dye. I have. For example, magnetic iron oxide powder, powdered lead iodide, carbon black, nigrosine, alkali blue, Hansa Yellow, quinacridone red, phthalocyanine blue and the like can be mentioned.

As another method of coloring, there is a method of dyeing a dispersion resin with a preferable dye as described in JP-A-57-48738. Alternatively, as another method, there is a method in which a dispersing resin and a dye are chemically bonded as disclosed in JP-A-53-54029.
As described in JP-A-44-22955 and the like, there is a method of producing a dye-containing copolymer by using a monomer containing a dye in advance when producing by a polymerization granulation method.

Various additives may be added to the liquid developer of the present invention, if desired, for the purpose of enhancing charging characteristics or improving image characteristics. For example, Yuji Harazaki, "Electrophotography", Vol.
And those specifically described on page 44 are used.

For example, metal salt of di-2-ethylhexyl sulfosuccinic acid,
Examples include a copolymer containing a metal salt of naphthenic acid, a metal salt of a higher fatty acid, lecithin, poly (vinylpyrrolidone), and a hemimaleamide component.

The amounts of the main components of the liquid developer of the present invention will be described below.

The amount of the toner component containing a resin and a coloring agent used as a main component is preferably 0.5 to 50 parts by weight based on 1,000 parts by weight of the carrier liquid. At the end of 0.5 parts by weight, the image density is insufficient, and when it exceeds 50 parts by weight, fogging to a non-image part tends to occur. Further, the carrier liquid-soluble resin for stabilizing the dispersion is also used as desired, and can be added in an amount of about 0.5 to 100 parts by weight based on 1,000 parts by weight of the carrier liquid. The charge control agent as described above is used in an amount of 0.1 to 1000 parts by weight of the carrier liquid.
001 to 1.0 part by weight is preferred. Further, various additives may be added as desired, and the upper limit of the total amount of these additives is regulated by the electric resistance of the developer. That is, if the electrical resistance of the liquid developer in a state where the toner particles are removed becomes lower than 10 ⁹ Ωcm, it becomes difficult to obtain a high-quality continuous tone image.
It is necessary to control the amount of each additive within this limit.

(Example) An example of the present invention will be described below, but the content of the present invention is not limited thereto.

Production Example 1 of dispersion stabilizing resin: Production of P-1 100 g of octadecyl methacrylate, divinylbenzene
A mixed solution of 2.0 g, 150 g of toluene and 50 g of isopropanol was heated to a temperature of 80 ° C. while stirring under a nitrogen stream.
2,2'-azobis (4-cyanovaleric acid) (abbreviated as ACV)
5.0 g was added and reacted for 8 hours. After cooling, the precipitate was reprecipitated in methanol 2 and the white powder was collected by filtration and dried. Obtained white powder 50
g, 7.6 g of glycidyl methacrylate, 0.5 g of t-butylhydroquinone, 0.5 g of N, N-dimethyldodecylamine and 100 g of toluene were heated to a temperature of 100 ° C. and stirred for 20 hours. The reaction mixture was reprecipitated in methanol 1, the pale yellow powder was collected by filtration and dried. The yield was 43 g and the weight average molecular weight was 9.5 × 10 ⁴ .

Production Examples 2 to 10 of Dispersion Stabilizing Resin: Production of P-2 to P-10 In Production Example 1, exactly the same as Production Example 1 except that the monomers shown in Table 1 below were used instead of octadecyl methacrylate. To produce the dispersion stabilizing resins P-2 to P-10. Weight average molecular weight of each resin is 9.0 × 10 ⁴ -10.5 ×
It was 10 ⁴ .

Production Examples 11 to 23 of Resin for Stabilizing Dispersion: Production of P-11 to P-23 In Production Example 1, instead of 2.0 g of divinylbenzene which is a polyfunctional monomer for crosslinking, a polyfunctional compound shown in Table 2 below was used. Each dispersion stabilizing resin P-11 to P-23 was produced in the same manner as in Production Example 1 except that a hydrophilic monomer or oligomer was used.

Production Example 24 of dispersion stabilizing resin Production of P-24 Octadecyl methacrylate 100 g, thiomalic acid 3 g,
4.5 g of divinylbenze, 150 g of toluene and 50 g of ethanol
Was heated to a temperature of 60 ° C. under a nitrogen stream. 2,
2'-azobis (isobutyronitrile) (abbreviation AIBN)
Was added and reacted for 5 hours, then 0.3 g of AIBN was added and reacted for 3 hours, and further 0.2 g of AIBN was added and reacted for 3 hours. After cooling, the precipitate was reprecipitated in methanol 2, and the white powder was collected by filtration and dried. The yield was 85 g.

A mixture of 50 g of the above powder and 100 g of toluene was heated to a temperature of 40 ° C. and dissolved with stirring. Next, 0.2 g of t-butyl hydroquinone, 8 g of vinyl acetate, and 0.03 g of mercury acetate were added and reacted for 2 hours. Raise the next temperature to 70 ℃, 100%
1.2 × 10 ⁻³ ml of sulfuric acid was added and reacted for 18 hours. After the reaction, sodium acetate trihydrate 3.60 was added to the reaction solution to add
After stirring for minutes, the mixture was cooled and reprecipitated in methanol 1.5. 41 g of a slightly brownish powder was obtained. The weight average molecular weight of this powder was 10.5 × 10 ⁴ .

Production Examples 25 to 30 of dispersion stabilizing resin: Production of P-25 to P-30 In the above Production Example 24, instead of thiomalic acid 3 g,
Production Example 24 was repeated except that the mercapto compound in Table 3 below was used.
In the same manner as described above, dispersion stabilizing resins P-25 to P-30 were produced.

Production Example 31 of dispersion stabilizing resin: Production of P-31 Same as Production Example 24 except that a mixed solution of 100 g of dodecyl methacrylate, 4 g of ethylene glycol dimethacrylate, 4 g of thioglycolic acid 2,3-epoxypropyl ester, and 200 g of toluene was used. To carry out a polymerization reaction.

Next, 6 g of crotonic acid, 2,2'-methylenebis- (6-
1.0 g of t-butyl-p-cresol) and 0.8 g of N, N-dimethyldodecylamine were added, and stirred at a temperature of 100 ° C. for 20 minutes.
Reacted for hours. The reaction mixture was reprecipitated in methanol 2 to obtain a pale yellow viscous substance by a decantation method and then dried. The yield was 75 g and the weight average molecular weight was 6.5 × 10 ⁴ .

Production Examples 32 to 40 of dispersion stabilizing resin: Production of P-32 to P-40 In the above Production Example 31, dodecyl methacrylate 100 g
Each of the dispersion stabilizing resins P- was prepared in the same manner as in Production Example 31 except that methacrylate and a carboxylic acid compound having a polymerizable double bond group shown in Table 4 below were substituted for crotonic acid and 6 g of crotonic acid. 32-40 were produced. The weight average molecular weight of each resin was 6.0 × 10 ^{4 to} 7.5 × 10 ⁴ .

Production Example 41 of dispersion stabilizing resin: Production of P-41 Tridecyl methacrylate 100 g, divinylbenzene 1.
A mixed solution of 2 g and 200 g of tetrahydrofuran was heated to a temperature of 70 ° C. while stirring under a nitriding gas flow. 6 g of 4,4'-azobis (4-cyanopentanol) was added and reacted for 8 hours. Next, after cooling the reaction product, methacrylic anhydride 6.
2 g, 0.8 g of t-butylhydroquinone and one drop of concentrated sulfuric acid were added, and the mixture was stirred at a temperature of 30 ° C. for 1 hour, and further stirred at a temperature of 50 ° C. for 3 hours. After cooling, methanol 2 was reprecipitated, the solution was removed by decantation, and a brown viscous substance was aggregated and dried. The yield was 88 g and the weight average molecular weight was 11.3 × 10 ⁴ .

Production Example 42 of Dispersion Stabilizing Resin: Production of P-42 A mixed solution of 100 g of octadecyl methacrylate, 1.1 g of ethylene glycol diacrylate and 200 g of tetrahydrofuran was heated to a temperature of 70 ° C. while stirring under a nitriding gas flow. 5 g of 4,4'-azobis (4-cyanopentanol)
The reaction was performed for 5 hours. Further, 1.0 g of the above azobis compound was added and reacted for 5 hours. The reaction mixture is placed in a water bath at a temperature of 20 ° C.
3.2 g of pyridine and 1.0 g of 2,2'-methylenebis- (6-t-butyl-p-cresol) were added thereto, followed by stirring. To this mixed solution, 4.2 g of methacrylic acid chloride was added dropwise over 30 minutes so that the reaction temperature did not exceed 25 ° C.
The mixture was stirred at a temperature of 20 ° C to 25 ° C for 4 hours. Next, the reaction product was reprecipitated in a mixed solution of methanol 1.5 / water 0.5, and a white powder was collected by filtration and dried. The yield was 82 g and the weight average molecular weight was 11.2 × 10 ⁴ .

Production Examples 43 to 51 of Dispersion Stabilizing Resins: Production of P-43 to P-51 Production Example 42 was the same as Production Example 42 except that the acid chloride of Table 5 below was used instead of methacrylic acid chloride.
The dispersion stabilizing resins P-43 to P-43
51 were manufactured. The weight average molecular weight of each resin is 10 × 10 ^{4 to} 20
× 10 ⁴

Production Example 52 of Dispersion Stabilizing Resin: Production of P-52 A mixed solution of 100 g of dodecyl dimethacrylate, 0.8 g of ethylene glycol methacrylate and 200 g of tetrahydrofuran was heated to a temperature of 65 ° C. downstream of nitriding. 4 g of 2,2'-azobis (4-cyanovaleric acid chloride) was added and the mixture was stirred for 10 hours. The reaction solution was cooled to a temperature of 25 ° C. or lower in a water bath, and 2.4 g of allyl alcohol was added. 2.5 g of pyridine was added dropwise so that the reaction temperature did not exceed 25 ° C., and the mixture was stirred for 1 hour. After stirring at a temperature of 40 ° C. for 2 hours, the mixture was reprecipitated in methanol 2. A pale yellow viscous substance was obtained by decantation and dried. The yield was 80 g and the weight average molecular weight was 10.5 × 10 ⁴ .

Production Examples 53 to 61 of Dispersion Stabilizing Resins: Production of P-53 to 61 In the above Production Example 24, methacrylates and polyfunctional monomers shown in Table 6 below were used in place of octadecyl methacrylate and divinylbenzene. Others are Production Example 24
Resins P-53 to P-61 were produced in the same manner as described above. The weight average molecular weight of each of the obtained resins was 9.0 × 10 ^{4 to} 12 × 10 ⁴ .

Production Example 1 of Macromonomer: Production of Macromonomer M-1 A mixed solution of 92 g of methyl methacrylate, 5 g of thioglycolic acid and 200 g of toluene was stirred under a nitriding gas stream.
Heated to a temperature of 75 ° C. 31 g of 2,2'-azobis (cyanovaleric acid) (abbreviated as ACV) was added and reacted for 8 hours. Next, 8 g of glycidyl methacrylate, 1.0 g of N, N-dimethyldodecylamine and 0.5 g of t-butylhydroquinone were added to the reaction solution, and the mixture was heated to 100 ° C. and stirred for 12 hours. After cooling, the reaction solution was reprecipitated in methanol 2 to obtain 82 g of a white powder. The number average molecular weight of the polymer was 6,500.

Production Example 2 of Macromonomer: Production of Macromonomer M-2 A mixed solution of 95 g of methyl methacrylate, 5 g of thioglycolic acid, and 200 g of toluene was stirred under a nitriding gas stream.
Heated to a temperature of 70 ° C. 1.5 g of 2,2'-azobis (isobutyronitrile) (abbreviation: AIBN) was added and reacted for 8 hours. Next, glycidyl methacrylate 7.5 was added to the reaction solution.
g, 1.0 g of N, N-dimethylpydecylamine and 0.8 g of t-butylhydroquinone were added, and the mixture was stirred at a temperature of 100 ° C. for 12 hours. After cooling, the reaction solution was reprecipitated in methanol 2 to obtain 85 g of a transparent and viscous substance. The number average molecular weight of the polymer was 2,400.

Production Example 3 of Macromonomer: Production of Macromonomer M-3 A mixed solution of 94 g of methyl methacrylate, 6 g of 2-mercaptoethanol and 200 g of toluene was heated to a temperature of 70 under a nitrogen stream.
Heated to ° C. 1.2 g of AIBN was added and reacted for 8 hours.

Next, the reaction solution was cooled in a water bath to a temperature of 20 ° C.,
Triethylamine (10.2 g) was added, and methacrylate chloride (14.5 g) was added dropwise with stirring at a temperature of 25 ° C. or lower. After the addition, the mixture was further stirred for 1 hour. Thereafter, 0.5 g of t-butylhydroquinone was added, the mixture was heated to a temperature of 60 ° C., and stirred for 4 hours. After cooling, the precipitate was reprecipitated in methanol 2 to obtain 79 g of a colorless and transparent viscous substance. The number average molecular weight was 4,500.

Production Example 4 of Macromonomer: Production of Macromonomer M-4 A mixed solution of 95 g of hexylmetallate and 200 g of toluene was heated to a temperature of 70 ° C. under a nitriding gas flow. 5 g of 2,2'-azobis (cyanoheptanol) was added and reacted for 8 hours.

After cooling, the temperature of the reaction solution was adjusted to 20 ° C. in a water bath, 1.0 g of triethylamine and 21 g of methacrylic anhydride were added, and the mixture was stirred for 1 hour and then at 60 ° C. for 6 hours.

After cooling the obtained reaction product, it was reprecipitated in methanol 2 to obtain 75 g of a colorless and transparent viscous substance. Number average molecular weight is 6,200
Met.

Production Example 5 of Macromonomer: Production of Macromonomer M-5 A mixture of 93 g of dodecyl methacrylate, 7 g of 3-mercaptopropionic acid, 170 g of toluene and 30 g of isopropanol was heated to a temperature of 70 ° C. under a nitrogen stream to obtain a homogeneous solution. 2.0 g of AIBN was added and reacted for 8 hours. After cooling, the precipitate was reprecipitated in methanol 2 and heated to 50 ° C. under reduced pressure to distill off the solvent. The obtained viscous material was dissolved in 200 g of toluene, and glycidyl metal acrylate 16 was added to this mixed solution.
g, N, N-dimethyldodecyl methacrylate 1.0 g and t-
1.0 g of butyl hydroquinone was added, and the mixture was stirred at 110 ° C. for 10 hours. This reaction solution was reprecipitated in methanol 2 again. The number average molecular weight of the obtained pale yellow viscous product was 3,400.

Production Example 6 of Macromonomer: Production of Macromonomer M-6 95 g of octadecyl methacrylate, thioglycolic acid 5
g and a mixed solution of 200 g of toluene were heated to a temperature of 75 ° C. while stirring under a nitrogen stream. 1.5 g of AIBN was added and reacted for 8 hours. Next, glycidyl methacrylate 13 was added to the reaction solution.
g, 1.0 g of N, N-dimethyldodecylamine and 1.0 g of t-butylhydroquinone were added, and the mixture was stirred at 110 ° C. for 10 hours. After cooling, the reaction solution was reprecipitated in methanol 2 to obtain 86 g of a white powder. The number average molecular weight was 2,300.

Production Example 7 of Macromonomer: Production of Macromonomer M-7 40 g of methyl metal acrylate, 5 of ethyl methacrylate
A mixture of 4 g, 6 g of 2-mercaptoethylamine, 150 g of toluene and 50 g of tetrahydrofuran was heated to a temperature of 75 ° C. while stirring under a nitrogen stream. Add 2.0g of AIBN, 8
Reacted for hours. Next, the reaction solution was heated to a temperature of 20 ° C. in a water bath, and 23 g of methacrylic anhydride was added dropwise thereto so that the temperature did not exceed 25 ° C., followed by further stirring for 1 hour. 0.5 g of 2,2'-methylenebis (6-t-butyl-p-cresol) was added, and the mixture was stirred at 40 ° C for 3 hours. After cooling, this solution was re-precipitated in methanol 2 to obtain a viscous substance (83 g).
I got The number average molecular weight was 2,200.

Production Example 8 of Macromonomer: Production of Macromonomer M-8 A mixed solution of 95 g of methyl metal acrylate and 200 g of toluene was heated to a temperature of 75 ° C. under a nitrogen stream. 5 g of ACV was added and reacted for 8 hours. Next, glycidyl acrylate 15
g, 1.0 g of N, N-dimethyldodecylamine and 1.0 g of 2,2'-methylenebis (6-t-butyl-p-cresol) were added, and the mixture was stirred at a temperature of 100 ° C. for 15 hours. After cooling, the reaction solution was reprecipitated in methanol 2 to obtain 83 g of a transparent viscous substance.
The number average molecular weight was 3,600.

Production Example 1 of Latex Particle 1: Production of Latex Particle D-1 12 g of P-1 resin obtained in Production Example 1 of dispersion stabilizing resin,
100 g of vinyl acetate, M- obtained in Production Example 1 of macromonomer
A mixed solution of 1.0 g of Macromonolar 1 and 380 g of Isopar H was heated to a temperature of 75 ° C. while stirring under a nitrogen stream.
1.7 g of AIBN was added and reacted for 6 hours. 20 after initiator addition
The mixture became cloudy and the reaction temperature rose to 88 ° C. The temperature was raised to 100 ° C. and the mixture was stirred for 2 hours to distill off unreacted vinyl acetate. After cooling, the mixture was passed through a nylon cloth of 200 mesh, and the resulting white dispersion was a latex having a polymerization rate of 90% and an average particle size of 0.20 μm.

Production Examples 2-11 of Latex Particles: Latex Particles D-2
Production of D-11 In latex particle production example 1, the following table was used in place of the dispersion stabilizing resin P-1 and the macromonomer M-1.
By operating in the same manner as in Production Example 1 except that each compound of No. 7 was used, a white dispersion having a polymerization rate of 85 to 90% was obtained.

Production Example 12 of Latex Particles: Production of Latex Particles D-12 13 g of the P-2 resin obtained in Production Example 2 of the dispersion stabilizing resin,
A mixed solution of 100 g of vinyl acetate, 5 g of crotonic acid, 1.0 g of M-1 obtained in Production Example 1 of macromonomer and 468 g of Isopar E was heated to a temperature of 70 ° C. while stirring under a nitrogen stream.
2,2'-azobis (isovaleronitrile) (abbreviation ACV
N.) was added, and after the reaction was completed for 6 hours, the temperature was raised to 100 ° C., and the mixture was stirred for 1 hour, and the remaining vinyl acetate was distilled off. After cooling, the mixture was passed through a 200-mesh nylon cloth, and the resulting white dispersion was a latex having a conversion of 85% and an average particle size of 0.25 μm.

Production Example 13 of Latex Particles: Production of Latex Particles D-13 14 g of the P-1 resin obtained in Production Example 1 of the dispersion stabilizing resin,
A mixed solution of 100 g of vinyl acetate, 6.0 g of 4-pentenoic acid, 1.5 g of M-7 obtained in Production Example 7 of macromonomer, and 380 g of Isopar G was heated to a temperature of 75 ° C. while stirring under a nitriding gas flow. Add 0.7g of AIBN and react for 4 hours.
0.5 g of N. was added and reacted for 2 hours. After cooling, it was passed through a 200-mesh nylon cloth, and the resulting white dispersion had an average particle size of 0.
It was a 26 μm latex.

Production Example 14 of Latex Particles: Production of Latex Particles D-14 14 g of P-2 resin obtained in Production Example 2 of dispersion stabilizing resin,
85 g of vinyl acetate, 15 g of N-vinylpyrrolidone, 1.2 g of M-1 obtained in Production Example 1 of macromonomer and 380 g of n-decane
Was heated to a temperature of 75 ° C. while stirring under a nitrogen stream. Add 1.7g of AIBN and react for 4 hours.
0.5 g of BN was added and reacted for 2 hours. After cooling, it was passed through a 200-mesh nylon cloth, and the resulting white dispersion had an average particle size of 0,0.
23 μm latex.

Production Example 15 of Latex Particles: Production of Latex Particles D-15 18 g of the P-1 resin obtained in Production Example 1 of the dispersion stabilizing resin,
Production example 2 of 100 g of methyl methacrylate, mocromonomer
A mixed solution of 1.5 g of M-2, 0.8 g of n-dodecylmercaptan and 470 g of n-octane obtained in the above was heated to a temperature of 70 ° C. while stirring under a nitrogen stream. 1.0 g of AIVN was added and reacted for 2 hours. A few minutes after the addition of the initiator, blue turbidity started and the reaction temperature rose to 90 ° C. After cooling, coarse particles were removed through a 200-mesh nylon cloth, and the resulting white dispersion was latex having a particle size of about 0.27 μm.

Production Example 16 of Latex Particles (Comparative Example A) The same procedure was followed as in Production Example 1 of latex particles except for the macromonomer M-1. The resulting white dispersion was a latex having a conversion of 85% and an average particle size of 0.20 μm.

Production Example 17 of Latex Particles (Comparative Example B) The same operation as in Production Example 1 was conducted except that 1.0 g of octadecyl methacrylate was used in place of Macromonomer M-1 in Production Example 1 of latex particles. The obtained white dispersion was a latex having a conversion of 85% and an average particle size of 0.22 μm.

Production Example 18 of Latex Particles (Comparative Example C) The same operation as in Production Example 1 was performed except that 1 g of a monomer having the following structure was used instead of Macromonomer M-1 in Production Example 1 of latex particles. The resulting white dispersion has a polymerization rate of
The latex was 86% and had an average particle size of 0.22 μm.

Example 1 10 g of a dodecyl methacrylate / acrylic acid copolymer [copolymerization ratio (95/5) weight ratio], 10 g of nigrosine and 30 g of Cielsol 71 were put together with glass beads in a paint shaker (Tokyo Seiki Co., Ltd.) Time-dispersed to obtain a fine dispersion of nigrosine.

The resin dispersion D-1 of Production Example 1 of latex particles was added to 30
g, 2.5 g of the above nigrosine dispersion, higher alcohol FOC-14
00 (manufactured by Nissan Chemical Industries, Ltd.) 15 g and octadecyl vinyl ether / half-maleic acid octadecylamide copolymer 0.08
The liquid developer for electrostatography was prepared by diluting g into 1 of Ciesol 71.

(Comparative Developers A to C) In the production examples of the liquid developer, the resin dispersion D-1 was replaced with the following resin dispersion, and comparative liquid developers A, B, and
Three types of C were produced.

Comparative Liquid Developer A: Latex Particle Production Example 16 Resin Dispersion Comparative Liquid Developer B: Latex Particle Production Example 17 Resin Dispersion Comparative Liquid Developer C: Latex Particle Production Example 18 Resin Dispersion The liquid developer is used as a developer for a fully automatic plate making machine ELP404V (manufactured by Fuji Photo Film Co., Ltd.), and an electrophotographic photosensitive material EPL Master II type (manufactured by Fuji Photo Film Co., Ltd.) is exposed. Developed. Plate making speed is
Performed at 6 plates / minute. In addition, ELP Master II type 2
After the processing of 000 sheets, the presence or absence of toner stains on the developing device was observed. The blackening rate (image area) of the copied image was determined using a 40% original. The results are shown in Table-8.

When the respective developers were subjected to plate making under the plate making conditions described above, only the case of the present invention was a developer which did not cause staining of the developing device and had a clear image on the 2000th plate making plate.

On the other hand, a master plate for offset printing (ELP-master) obtained by making a plate from each developer is printed by a conventional method, and the number of printed sheets until the occurrence of missing characters, solid portions, etc. in the printed image is compared. The present invention, Comparative Example A
In addition, the master plate obtained using the developer of Comparative Example C did not generate even at 10,000 sheets or more, and the master plate using Comparative Example B generated at 8,000 sheets.

As described above, only the developer using the resin particles of the present invention as a developer did not cause any stain on the developing device, and also significantly improved the number of printed master plates.

That is, in the case of Comparative Example A, there was no problem with the number of printed sheets, but the developing device was significantly stained and could not withstand continuous use.

Further, in the case of Comparative Examples B and C, when the plate making speed is as high as 6 sheets / min (conventionally, plate making speed of 2 to 3 sheets / min), the developing device (especially on the back electrode plate) , And after 2,000 sheets, the image quality of the copied image on the plate was affected (reduction in _Dmax , blurred thin lines, etc.). In Comparative Example C, there was no problem with the number of printed master plates, but in Comparative Example B, the number decreased.

These results show that the resin particles of the present invention are clearly superior.

Example 2 A mixture of 100 g of the white resin dispersion D-1 obtained in Production Example 1 of latex particles and 1.5 g of Sumicalon Black was heated to a temperature of 100 ° C., and heated and stirred for 4 hours. After cooling to room temperature 2
The remaining dye was removed through a 00 mesh nylon cloth to obtain a black resin dispersion having an average particle size of 0.2 μm.

32 g of the above black resin dispersion, zirconium naphthenate 0.0
A liquid developer was prepared by diluting 5 g into 1 of Cielsol 71.

When this was developed by the same apparatus as in Example 1, 2,000
Even after the development of 0 sheets, no toner adhesion stains occurred on the apparatus.

Further, the image quality of the obtained master plate for offset printing was clear, and the image quality of the printed matter after printing 10,000 sheets was also very clear.

Example 3 A mixture of 100 g of the white resin dispersion D-12 obtained in Production Example 12 of latex particles and 3 g of Victoria Blue B was heated to a temperature of 70 to 80 ° C and stirred for 6 hours. 200 after cooling to room temperature
The remaining dye was removed through a mesh nylon cloth to obtain a blue resin dispersion having an average particle size of 0.25 μm.

32 g of the above blue resin dispersion, higher alcohol FOC-1600
(Nissan Chemical Co., Ltd.) 10 g, zirconium naphthenate 0.0
A liquid developer was prepared by diluting 5 g to 1 of Isopar H.

This was developed with the same apparatus as in Example 1, and
Even after the development of 000 sheets, no toner adhesion stains were observed on the apparatus. Further, the image quality of the obtained master plate for offset printing was clear, and the image quality of the printed matter after printing 10,000 sheets was also very clear.

Example 4 White resin dispersion D- obtained in Production Example 2 of latex particles
32, 2.5 g of the nigrosine dispersion obtained in Example 1, 0.02 g of a semi-docosanyl amidated copolymer of diisobutylene and maleic anhydride, and 15 g of higher alcohol FOC-1400 (manufactured by Nissan Chemical Co., Ltd.) in Isopar G By diluting to 1, the liquid developer was prepared.

When this was developed by the same apparatus as in Example 1, 2,000
Even after sheet development, no toner adhesion stains were observed on the apparatus. Further, the image quality of the obtained master plate for offset printing and the image quality of the printed matter after 10,000 sheets were printed were clear.

After the developer was allowed to stand for three months, the same treatment as above was performed, but it was not different from that before the lapse of time.

Example 5 10 g of poly (decylmethacrylate), 30 g of Isopar H
And 8 g of alkali blue together with glass beads were placed in a paint shaker and dispersed for 2 hours to obtain a fine dispersion of alkali blue.

30 g of the white resin dispersion D-11 obtained in Production Example 11 of latex particles, 4.2 g of the above-described alkali blue dispersion, and 0.06 g of a half-docosanyl amidated copolymer of diisobutylene and maleic anhydride were added to Isopar G. By diluting to 1, a liquid developer was prepared.

When this was developed by the same apparatus as in Example 1, 2,000
No toner adhesion stains were observed on the apparatus even after developing 0 sheets. In addition, the image quality of the obtained master plate for offset printing and the image quality of printed matter after 10,000 sheets were printed were very clear.

Examples 6 to 13 Instead of the latex particles D-1 in Example 1,
A liquid developer of the present invention was prepared in the same manner as in Example 1, except that the latex particles D-3 to D-10 shown in Table 9 below were used.

When these were developed by the same apparatus as in Example 1, 2,
Even after the development of 000 sheets, no toner adhesion stain on the apparatus was observed. In addition, the image quality of the obtained master plate for offset printing and the image quality of printed matter after 10,000 sheets were printed were very clear.

(Effect of the Invention) According to the present invention, a developer having excellent dispersion stability, redispersibility, and fixability was obtained. In particular, even when used under plate-making conditions with very high plate-making speed, the developing device is not stained, and the image quality of the obtained master plate for offset printing and the image quality of printed matter after 10,000 sheets have been printed are very clear. Was.

Claims (1)

(57) [Claims] An electrophotographic liquid developer comprising at least a resin dispersed in a non-aqueous medium having an electric resistance of not less than 10 ⁹ Ωcm and a dielectric constant of not more than 3.5. A polymer containing at least the repeating unit represented by I), a part of which is cross-linked, and
In the presence of a dispersion stabilizing resin soluble in the non-aqueous solvent, wherein a polymerizable double bond group copolymerizable with the monofunctional monomer (A) is bonded to only one end of at least one polymer main chain. In addition, one of the main chain of a polymer comprising a monofunctional monomer (A) which is soluble in a non-aqueous solvent but is insolubilized by polymerization, and a repeating unit represented by the following general formula (II) Containing at least one monofunctional macromonomer (B) having a number average molecular weight of 10 ⁴ or less, which is formed by bonding a polymerizable double bond group represented by the following general formula (III) only to the terminal of A liquid developer for electrostatic photography characterized by being a copolymer resin particle obtained by a polymerization reaction of General formula (I) In the general formula (I), X ¹ represents —COO—, —OCO—, —CH ₂ OCO—,
-CH ₂ COO -, - O-, or -SO ₂ - represent. R ¹ represents a hydrocarbon group having 6 to 32 carbon atoms. a ¹ and a ² may be the same or different from each other, and each represents a hydrogen atom, a halogen atom, a cyano group, a hydrocarbon group having 1 to 8 carbon atoms, -COO-R ² or a hydrocarbon group having 1 to 8 carbon atoms. Represents —COO—R ² (R ² represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms). General formula (II) General formula (III) In the general formula (II), Y ¹ represents —COO—, —OCO—, —CH ₂ OCO—,
_{-CH 2 COO -, - O -} , - SO 2 -, (R ⁴ represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms). R ³ represents a hydrocarbon group having 1 to 22 carbon atoms. b ¹ and b ² may be the same or different from each other, and each represents a hydrogen atom, a halogen atom, a cyano group, a hydrocarbon group having 1 to 8 carbon atoms, -COO-R ⁵ or a hydrocarbon group having 1 to 8 carbon atoms. Represents a group represented by —COO—R ⁵ (R ⁵ represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms). In formula (III), Y ² has the same meaning as Y ¹ in formula (II). d ¹ and d ² may be the same or different from each other,
Each is synonymous with b ¹ or b ² in the general formula (II).