JP2916562B2 - Liquid developer for electrostatic photography - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention is an electric resistance 10 ⁹ [Omega] cm or more, and relates to an electrostatic photographic liquid developer formed by dispersing at least resin dielectric constant of 3.5 or less of the carrier liquid, especially redispersion The present invention relates to a liquid developer having excellent stability, storage stability, stability, image reproducibility, and fixability.

[0002]

2. Description of the Related Art A general liquid developer for electrophotography uses 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 as a petroleum-based liquid developer. 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 as insoluble latex particles in the form of particles having a diameter of several nanometers to several hundreds of nanometers. However, in a conventional liquid developer, a soluble dispersion stabilizing resin or a polarity controlling agent and an insoluble latex particle are used. Insufficient bonding with the polymer resulted in a state where the soluble dispersion stabilizing resin and the polarity controlling agent were easily diffused into the solution. For this reason, the soluble dispersion stabilizing resin is detached from the insoluble latex particles by long-term storage or repeated use,
Particles settle, agglomerate, deposit, or become ambiguous,
There was a disadvantage. Further, since the particles once aggregated and deposited are difficult to re-disperse, the particles remain adhered to various parts of the developing device, 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, means for chemically bonding a soluble dispersion stabilizing resin and insoluble latex particles have been devised, and are disclosed in, for example, 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 to be used and a monomer to be insolubilized. The resulting particles were large in particle size distribution containing a large amount of coarse particles, or polydispersed particles having two or more average particle diameters. Also, 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, the insolubility 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 polar components is considered. A method of improving the degree of dispersion, redispersibility, and storage stability of particles by forming dispersed resin particles is disclosed in JP-A-60-17.
9751, 62-151868 and the like. Further, in the presence of a polymer utilizing a bifunctional monomer or a polymer utilizing a polymer reaction, an insoluble dispersed resin particle of a copolymer of a monomer insolubilized and a monomer containing a long-chain alkyl moiety A method for improving the degree of dispersion, redispersibility and storage stability of particles by using
Nos. 2-166362 and 63-66567. Further, as a dispersion stabilizing polymer, a conventional random copolymer is converted into a block copolymer of a polymer part to be solvated and a non-solvable polymer part, thereby improving redispersibility and storage stability. An improved method is disclosed in Japanese Unexamined Patent Publication No. Hei.
No. 6, No. 3-225353.

[0005]

On the other hand, in recent years, a method of printing a large number of sheets of 5,000 or more using an electrophotographic offset printing master plate has been attempted. It has become possible to print 10,000 sheets or more in plate size. or,
The operation time of the electrophotographic plate making system has been shortened, and the development-fixing process has been improved to be faster. Dispersions manufactured according to the means disclosed in the above-mentioned JP-A-60-179751, JP-A-62-151868, JP-A-62-166362, JP-A-63-66567, JP-A-3-12666 and JP-A-3-225353. Resin particles, when the development speed is increased, in terms of particle dispersibility, redispersibility,
In the case where the fixing time is shortened or in the case of a master plate of a large plate size (for example, A-3 size or more),
In terms of printing durability, the performance was not always satisfactory.

The present invention solves the above-mentioned problems of the conventional liquid developer. The purpose of the present invention is
An object of the present invention is to provide a liquid developer which has a rapid development-fixing process and is excellent in dispersion stability, re-dispersibility and fixability even in an electrophotographic plate making system using a large-size master plate. Another object of the present invention is to provide a liquid developer capable of producing an offset printing master having excellent printing ink 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.

[0007]

An object of the present invention is to provide a liquid developer for electrostatography comprising at least resin particles dispersed in a non-aqueous solvent having an electric resistance of not less than 10 ⁹ Ωcm and a dielectric constant of not more than 3.5. In the above, at least one kind of the monofunctional monomer (A), which is soluble in the non-aqueous solvent but insoluble by polymerization,
And phosphono group, carboxyl group, sulfo group, hydroxyl group, formyl group, amino group, -P (= O) (OH)
R ¹ group [R ¹ represents a -R ² group or -OR ² group, R ²
Represents a hydrocarbon group], -CONR ³ R ⁴ group, -SO ₂
A polymer component containing an NR ³ R ⁴ group (R ³ and R ⁴ each independently represent a hydrogen atom or a hydrocarbon group) and at least one polar group selected from cyclic acid anhydride-containing groups And / or a block A containing at least one polymer component corresponding to the monofunctional monomer (A) and a block B containing at least one polymer component represented by the following general formula (I). A to B type block polymer chain is formed by bonding at least three organic molecules,
The B-type block polymer chain is bonded to the organic molecule at one end of the polymer main chain of the block A opposite to the end bonded to the block B, and has a weight average molecular weight of 2 ×
A polymer resin particle obtained by polymerizing a mixture containing at least one dispersion stabilizing resin [P] composed of a star copolymer, which is 10 ⁴ to 1 × 10 ^6. Achieved by the characteristic liquid developer for electrostatography.

[0008]

Embedded image

In the general formula (I), X ¹ is -COO-, -O
_{CO -, - (CH 2)} x COO -, - (CH 2) x OC
O- [where x represents an integer of 1 to 3], or -O-. Y ¹ represents an aliphatic group having 8 or more carbon atoms. a ¹ and a ² may be the same or different, and each represents a hydrogen atom, a halogen atom, a cyano group, a hydrocarbon group, —COO—
Z ¹ or —COO—Z ¹ via a hydrocarbon group (here, Z ¹ represents a hydrogen atom or a hydrocarbon group which may be substituted).

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,
As the carrier liquid having a dielectric constant of 3.5 or less, preferably, a linear or branched aliphatic hydrocarbon, alicyclic hydrocarbon, or aromatic hydrocarbon, and a halogen-substituted product thereof 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; trade name of Exxon), Shersol 7
0, Shellsol 71 (Shellsol; trade name of Shell Oil), Amsco OMS, Amsco 460 solvent (Amsco; trade name of Spirits) and the like are used alone or in combination.

The non-aqueous dispersion resin particles (hereinafter sometimes referred to as latex particles), which are the most important constituents in the present invention, are used in a non-aqueous solvent to disperse the star-type block copolymer of the present invention. Polymerizing the monofunctional monomer (A) in the presence of the resin [P] (so-called,
(Polymerization granulation method).

Here, as the non-aqueous solvent, basically,
Any material can be used as long as it is miscible with the carrier liquid of the liquid developer for electrostatography. That is, the solvent used in 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, isoper E,
Isopar G, Isopar H, Isopar L, Shellsol 70, Shellsol 71, Amsco OMS, Amsco 460 solvent and the like are used alone or in combination.

Solvents which can be used by mixing with these organic solvents include alcohols (eg, methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, fluorinated alcohol, etc.) and ketones (eg, acetone, methyl ethyl ketone, etc.). Carboxylic acid 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.). It is desirable that the non-aqueous solvent used by mixing these be distilled off under heating or under reduced pressure after polymerization granulation. However, even if the non-aqueous solvent is brought into a liquid developer as a latex particle dispersion, the liquid There is no problem as long as the resistance is within the range of 10 ⁹ Ωcm or more. Normal,
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, and halogenated hydrocarbons And the like.

The monofunctional monomer (A) in the present invention comprises
Any monofunctional monomer that is soluble in a nonaqueous solvent but insolubilized by polymerization may be used. Specifically, for example, a monomer represented by the following general formula (II) can be mentioned.

[0015]

Embedded image

In the general formula (II), T ¹ is -COO-, -O
_{CO -, - CH 2 OCO -} , - CH 2 COO -, - O-,
-CONHCOO-, -CONHOCO-, -SO
^{_{2 -, - CON (W 1}} ) -, - SO 2 N (W 1) -, or -Ph- [wherein, Ph represents a 1,2-, 1,3- or 1,4-phenylene group] Represents W ¹ is a hydrogen atom or an optionally substituted aliphatic group having 1 to 8 carbon atoms (for example, a methyl group, an ethyl group, a propyl group, a butyl group,
-Chloroethyl group, 2-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 group, 3
-Methoxypropyl group).

D ¹ is a hydrogen atom or an optionally substituted aliphatic group having 1 to 6 carbon atoms (eg, a methyl group, an ethyl group, a propyl group, a butyl group, a 2-chloroethyl group, a 2,2-dichloroethyl group) 2,2,2-trifluoroethyl group, 2
-Bromoethyl group, 2-glycidylethyl group, 2-hydroxyethyl group, 2-hydroxypropyl group, 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-carboxyamidoethyl group, 3
-Sulfamidopropyl group, 2-N-methylcarboxamidoethyl group, cyclopentyl group, chlorocyclohexyl group, dichlorohexyl group, etc.).

B ¹ and b ² may be the same or different from each other, and are each a ¹ or a ² in the general formula (I).
Represents the same content as.

Specific monofunctional monomers (A) include:
For example, vinyl esters or allyl esters of aliphatic carboxylic acids having 1 to 6 carbon atoms (acetic acid, propionic acid, butyric acid, monochloroacetic acid, trifluoropropionic acid, etc.); acrylic acid, methacrylic acid, crotonic acid, itaconic acid, C1-C4 alkyl esters or amides of unsaturated carboxylic acids such as maleic acid (for example, methyl, ethyl, propyl, butyl, 2-chloroethyl, 2-chloroethyl, Bromoethyl group, 2-fluoroethyl group, 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-
Styrene derivatives (eg, styrene, vinyltoluene, α-methylstyrene,
Vinylnaphthalene, chlorostyrene, dichlorostyrene, bromostyrene, vinylbenzenecarboxylic acid, vinylbenzenesulfonic acid, chloromethylstyrene, hydroxymethylstyrene, methoxymethylstyrene, N, N
-Dimethylaminomethylstyrene, vinylbenzenecarboxamide, vinylbenzenesulfonamide, etc.); unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, and itaconic acid; cyclic acid anhydrides of maleic acid and itaconic acid; Acrylonitrile; Methacrylonitrile; Heterocyclic compound containing a polymerizable double bond group (specifically, for example, “Polymer Data Handbook -Basic Part-”, edited by The Society of Polymer Science, pp. 175-184, Baifukan (1986) ), For example, N-vinylpyridine, N
-Vinylimidazole, N-vinylpyrrolidone, vinylthiophene, vinyltetrahydrofuran, vinyloxazoline, vinylthiazole, N-vinylmorpholine, etc.)
And the like. Two or more monomers (A) may be used in combination.

Next, the dispersion stabilizing resin [P] of the present invention will be described. The resin [P] is a star copolymer having a weight average molecular weight of 2 × 10 ⁴ to 1 × 10 ⁶ , wherein at least three polymer chains of the AB block copolymer component are bonded in an organic molecule. It is. One block (block A) that binds to the organic molecule is a phosphono group, a carboxyl group,
Sulfo group, hydroxyl group, formyl group, amino group,-
P (＝ O) (OH) R ¹ group [R ¹ is a —R ² group or —O
Shows the R ² groups, R ² represents a hydrocarbon group], -CONR
³ R ⁴ groups, —SO ₂ NR ³ R ⁴ groups [R ³ and R ⁴ are
Each independently represents a hydrogen atom or a hydrocarbon group], and a polymer component containing at least one polar group selected from cyclic acid anhydride-containing groups and / or the monofunctional monomer (A) It comprises at least one kind of polymer component corresponding to the above. Another one block (Block B)
Comprises at least one polymer component comprising a repeating unit represented by the general formula (I). Here, the order of the sequence in the polymer chain of the block A and the block B is such that the block A is one end of the polymer main chain opposite to the end bonded to the block B and is bonded to an organic molecule. The resin [P] is schematically shown as in the following chemical formula 4.

[0021]

Embedded image

In the chemical formula 4, X represents an organic molecule;
(A) represents block A, (B) represents block B,
(A)-(B) represent a polymer chain. In addition, such AB
The upper limit of the number of the type block polymer chains contained in the organic molecule is at most 15, usually about 10.

The proportion of the blocks A and B in the star copolymer is from 1/50/99 to 50 (weight ratio), preferably from 5/40/95 to 60 (weight ratio). The specific polar group-containing polymer component contained in the block A is preferably 1 to 30 parts by weight, more preferably 1 to 15 parts by weight, per 100 parts by weight of the dispersion stabilizing resin [P]. When no specific polar group-containing polymer component is present in the block A, the polymer component corresponding to the monofunctional monomer (A) preferably has a content of 5 to 100 parts by weight of the resin [P]. It is 50 parts by weight, more preferably 10 to 40 parts by weight. The polymer component represented by the general formula (I) contained in the block B includes:
Preferably 50 in 100 parts by weight of the dispersion stabilizing resin [P].
To 99 parts by weight, more preferably 60 to 95 parts by weight. In the dispersion stabilizing resin [P], the above-mentioned predetermined existence ratio (that is, the above-mentioned block A and block B
, The proportion of the specific polar group-containing polymer component contained in the block A, and the proportion of the polymer component represented by the general formula (I) contained in the block B). The re-dispersion stability of the dispersed resin particles obtained by polymerizing the monofunctional monomer (A) is reduced. On the other hand, if it exceeds the predetermined ratio, the average particle size of the dispersed resin particles obtained by the polymerization reaction of the monofunctional monomer (A) is increased, and the monodispersity of the particle distribution is reduced. .

Next, block A of dispersion stabilizing resin [P]
Will be described in detail. The block A is composed of a polymer component corresponding to the monofunctional monomer (A) and / or the above-mentioned polymer component containing a specific polar group. Examples of the polymer component corresponding to the monofunctional monomer (A) include the same contents as described above for the insoluble monomer (A). Preferably, it is composed of the same monomer as the monofunctional monomer (A) to be the dispersed resin particles.

In a specific polar group, -P (= O) (OH) R
^{In one} group, R ¹ represents a —R ² group or an —OR ² group, and R ² represents a hydrocarbon group having 1 to 10 carbon atoms. As the hydrocarbon group for R ^2, an aliphatic group having 1 to 8 carbon atoms which may be substituted (for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a butenyl group, a pentenyl group, A hexenyl group, a 2-chloroethyl group, a 2-cyanoethyl group, a cyclopentyl group, a cyclohexyl group, a benzyl group, a phenethyl group, a chlorobenzyl group, a bromobenzyl group, and the like; and an optionally substituted aromatic group (for example, a phenyl group, a tolyl group) Group, xylyl group, mesityl group, chlorophenyl group, bromophenyl group, methoxyphenyl group, cyanophenyl group, etc.).

In a specific polar group, -CONR ³ R ⁴
In the group, and -SO ₂ NR ³ R ⁴ group, R ³ and R
⁴ are each independently a hydrogen atom or a hydrocarbon group (C 1
-10, preferably an optionally substituted hydrocarbon group having 1-8 carbon atoms). Specific examples of the hydrocarbon group represented by R ³ and R ⁴ include those having the same contents as the hydrocarbon group represented by R ² .

The cyclic acid anhydride-containing group is a group containing at least one cyclic acid anhydride. Examples of the cyclic acid anhydride include aliphatic dicarboxylic anhydride and aromatic dicarboxylic anhydride. Things. Examples of the aliphatic dicarboxylic anhydride include succinic anhydride, glutaconic anhydride, maleic anhydride, cyclopentane-1,2
-Dicarboxylic anhydride, cyclohexane-1,2-dicarboxylic anhydride, cyclohexene-1,2-dicarboxylic anhydride, 2,3-bicyclo [2,2,2] octanedicarboxylic anhydride, and the like, These aliphatic dicarboxylic anhydrides may be substituted with, for example, a halogen atom such as a chlorine atom or a bromine atom, or an alkyl group such as a methyl group, an ethyl group, a butyl group or a hexyl group. Examples of the aromatic dicarboxylic anhydride include phthalic anhydride, naphthalene-dicarboxylic anhydride, pyridine-dicarboxylic anhydride, thiophene-dicarboxylic anhydride and the like. The product is, for example, a chlorine atom, a halogen atom such as a bromine atom, an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a hydroxyl group, a cyano group, a nitro group, an alkoxycarbonyl group (as an alkoxy group, For example, it may be substituted with a methoxy group, an ethoxy group and the like.

Further, among the specific polar groups, the amino group is represented by -N
Represents H ₂ , —NHR ⁵ or —NR ⁵ R ⁶ . R ⁵ , R ⁶
Represents a hydrocarbon group having 1 to 10, preferably 1 to 8 carbon atoms. More preferably represents a hydrocarbon group having 1 to 7 carbon atoms, specifically, include those of the same contents as the hydrocarbon group represented by R ^2.

The hydrocarbon group of R ² , R ³ , R ⁴ , R ⁵ and R ⁶ is still more preferably an alkyl group having 1 to 4 carbon atoms which may be substituted, a benzyl group which may be substituted, Or a phenyl group which may be substituted.

The monomer corresponding to the polymer component containing the specific polar group may be any monofunctional monomer containing at least one specific polar group.
For example, it is described in “Polymer Data Handbook [Basic Edition]” edited by the Society of Polymer Science, Baifukan (1986). Specifically, acrylic acid, alpha-and / or β- substituted acrylic acids (e.g., alpha-acetoxy body, alpha-acetoxymethyl body, alpha-(2-amino) an ethyl body, alpha-chloro body, alpha-
Bromo form, α- fluoro form, α-tributylsilyl form,
α-cyano form, β-chloro form, β-bromo form, α-chloro-β-methoxy form, α, β-dichloro form, etc.), methacrylic acid, itaconic acid, itaconic acid half esters, itaconic acid semiamides , Crotonic acid, 2-alkenylcarboxylic acids (eg, 2-pentenoic acid, 2-methyl-2-hexenoic acid, 2-octenoic acid, 4-methyl-2-hexenoic acid,
4-ethyl-2-octenoic acid, etc.), maleic acid, maleic acid half-esters, maleic acid half-amides, vinylbenzene carboxylic acid, vinylbenzenesulfonic acid, vinylsulfonic acid, vinylphosphonic acid, vinyl group or allyl of dicarboxylic acids Half ester derivatives of these groups; ester derivatives of these carboxylic acids or sulfonic acids; and compounds containing the polar group in the substituents of the amide derivatives.

Specific examples of these compounds include the following. However, in each of the following examples, e
Is _{-H, -CH 3, -Cl, -Br} , -CN, -CH 2
COOCH ₃ or —CH ₂ COOH, f represents —H or —CH ₃ , n represents an integer of 2 to 10, and m represents 1
Represents an integer of 10 to 10, and p represents an integer of 1 to 4. X ₁ is -COOH, -O-P (= O ) (OH) 2, -SO
_{3 H, -OH, -NR a R} b, -CHO or -O-P
(= O) (OH) _Ra is shown. Here, R _a and R _b represent an alkyl group having 1 to 4 carbon atoms. X ₂ represents a -COOH or -OH.

[0032]

Embedded image

[0033]

Embedded image

[0034]

Embedded image

Next, block B of dispersion stabilizing resin [P]
The repeating unit represented by the general formula (I) constituting the formula (I) will be described in detail. In the general formula (I), X ¹ preferably represents -COO-, -OCO- or -O-. Y
¹ preferably represents an alkyl group or an alkenyl group having 10 or more carbon atoms, which may be linear or branched.
Specifically, decyl group, dodecyl group, tridecyl group, tetradecyl group, hexadecyl group, octadecyl group, eicosanyl group, docosanyl group, decenyl group, dodecenyl group, tridecenyl group, hexadecenyl group, octadecenyl group, linolel group, etc. .

A ¹ and a ² may be the same or different from each other, and are preferably a hydrogen atom, a halogen atom (eg, a chlorine atom, a bromine atom, etc.), a cyano group, and a carbon number of 1 to 3.
Alkyl group (e.g., methyl group, ethyl group, propyl group, etc.), - COO-Z ¹ or -CH ₂ COO-Z ¹ [Z
¹ is a hydrogen atom or an optionally substituted hydrocarbon group having 22 or less carbon atoms (for example, an alkyl group, an alkenyl group,
Aralkyl group, alicyclic group, aryl group, etc.).

Specifically, Z ¹ is, in addition to a hydrogen atom, a preferred hydrocarbon group such as an alkyl group having 1 to 22 carbon atoms which may be substituted (eg, a methyl group, an ethyl group, a propyl group, a butyl group). Group, heptyl group, hexyl group, octyl group, nonyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group, hexadecyl group, octadecyl group, eicosanyl group, docosanyl group, 2-chloroethyl group, 2-bromoethyl group, 2- Cyanoethyl group, 2-methoxycarbonylethyl group, 2-methoxyethyl group, 3
-Bromopropyl group, etc.), and an optionally substituted alkenyl group having 4 to 18 carbon atoms (for example, 2-methyl-1-propenyl group, 2-butenyl group, 2-pentenyl group, 3-methyl-2-pentenyl group) , A 1-pentenyl group, a 1-hexenyl group, a 2-hexenyl group, a 4-methyl-2-hexenyl group, a decenyl group, a dodecenyl group, a tridecenyl group, a hexadecenyl group, an octadecenyl group, a linolel 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 and the like, and an optionally substituted aromatic group having 6 to 12 carbon atoms (for example, phenyl group, naphthyl group, tolyl group, xylyl group, propylphenyl group, butylphenyl group) Octylphenyl, dodecylphenyl, methoxyphenyl, ethoxyphenyl, butoxyphenyl, decyloxyphenyl, chlorophenyl, dichlorophenyl, bromophenyl, cyanophenyl, acetylphenyl, methoxycarbonylphenyl, ethoxy Carbonylphenyl group, butoxycarbonylphenyl group, acetamidophenyl group, propioamidophenyl group, dodecylylamidophenyl group, etc.).

Further, in the block B of the dispersion stabilizing resin used in the present invention, other repeating units may be contained as a copolymer component together with the repeating units represented by the general formula (I). The other copolymer component may be any compound as long as it is composed of a monomer copolymerizable with the monomer corresponding to the repeating unit of the general formula (I). However, it is preferable not to contain other components, and it is used in an amount not exceeding 20 parts by weight in the block B at most. If the amount exceeds 20 parts by weight, the dispersion stability of the dispersed resin particles will be deteriorated. In the block B, two or more kinds of the repeating units represented by the general formula (I) may be used in combination.

On the other hand, the organic molecule according to the present invention comprising at least three polymer chains bonded is not particularly limited as long as the molecular weight of the molecule is 1,000 or less. For example, a trivalent hydrocarbon residue represented by the following formula 8 may be mentioned.

[0040]

Embedded image

Wherein r ^{1 to} r ⁶ each represent a hydrogen atom or a hydrocarbon group. However, at least one of r ¹ and r ² is connected to the polymer chain, and at least one of r ^{3 to} r ⁶ is connected to the polymer chain. These organic residues are
Consists structure alone or any combination thereof, in the case of combination, -O -, - S -, - N (r 7) -, - COO
^{-, - CON (r 7)} -, - SO 2 -, - SO 2 N (r
⁷ )-{where r ⁷ represents a hydrogen atom or a hydrocarbon group}, -NHCOO-, -NHCONH-, an oxygen atom,
Bonding of hetero atoms containing hetero atoms such as sulfur atoms and nitrogen atoms (for example, thiophene ring, pyridine ring, pyran ring, imidazole ring, benzimidazole ring, furan ring, piperidine ring, pyrazine ring, pyrrole ring, piperazine ring, etc.) It may include a combination of units.

Examples of other organic molecules that bind the polymer chain include those composed of a combination of the following chemical formulas and the above-mentioned binding units. However, specific examples of the organic molecule according to the present invention are not limited to these.

[0043]

Embedded image

The star type copolymer [P] of the present invention can be synthesized by using a conventionally known method for synthesizing a star type polymer of a monomer having a polar group and having a polymerizable double bond group. it can. For example, one of them is a polymerization reaction using a carbanion as an initiator. Specifically, M. Morton,
TE Helminiak et al “J. Polym. Sci.” 57, 471 (19
62), B. Gordon III, M, Blumenthal, JE Loftus et
al “Polym. Bull.” 11,349 (1984), RB Bates, W.
A. Beavers et al “J. Org. Chem.” 44, 3800 (1979)
Can be synthesized according to the method described in (1). However, when this reaction is used, the “specific polar group” of the present invention is used as a protected functional group, polymerized, and then the protective group is eliminated. The protection of the specific polar group of the present invention by a protective group and the elimination of the protective group (deprotection reaction) can be easily carried out by utilizing conventionally known knowledge. For example, various descriptions are given in the above cited references. Furthermore, Yoshio Iwakura and Keisuke Kurita, "Reactive Polymers", published by Kodansha (1977)
TW Greene “Protective Groups in Organic S”
ynthesis ”(JohnWiley & Sons, 1981), JFW Mc
Omic “Protective Groups in Organic Chemistry” (Pl
enum Press, 1973) and the like.

[0045] Other methods, starting compounds containing a specific reference to monomers which remain protecting the polar group, a compound containing di-thiocarbamate <br/> group and / or a xanthate group of the present invention As an agent, it can also be synthesized by performing a polymerization reaction under light irradiation. For example, Takayuki Otsu “Polymer” 3
7 , 248 (1988), Shunichi Hinomori, Ryuichi Otsu “Polym. Rep. Ja
p., 37 , 3508 (1988), JP-A-64-111, JP-A-64-26619, Nobuyuki Higashi et al., "Polymer Preprints, J
apan ” 36 (6), 1511 (1987), M. Niwa, N. Higashi et
al “J. Macromol. Sci. Chem.” A24 (5), 567 (198
It can be synthesized according to the synthesis method described in 7).

In order to produce the dispersion resin particles used in the present invention, generally, the dispersion stabilizing resin [P] and the monomer (A) as described above are mixed with benzoyl peroxide, azobis Heat polymerization may be performed in the presence of a polymerization initiator such as isobutyronitrile and butyllithium. Specifically, a method of adding a polymerization initiator to a mixed solution of the dispersion stabilizing resin [P] and the monomer (A), a method in which the monomer (A) is dissolved in a solution in which the dispersion stabilizing resin [P] is dissolved. ) Is dropped together with the polymerization initiator, or the remaining monomer (A) is added together with the polymerization initiator to a mixed solution containing the whole amount of the dispersion stabilizing resin [P] and a part of the monomer (A). ), And a method of optionally adding a mixed solution of the dispersion stabilizing resin [P] and the monomer (A) together with the polymerization initiator in a non-aqueous solvent. It can also be manufactured by using the method described above.

The total amount of the monomer (A) is about 5 to 50 parts by weight, preferably 1 to 100 parts by weight of the nonaqueous solvent.
0 to 30 parts by weight. The dispersion stabilizing resin [P] is used in an amount of 1 to 50 parts by weight, preferably 5 to 30 parts by weight, based on 100 parts by weight of the total monomers used above. The amount of the polymerization initiator is suitably from 0.1 to 5% by weight based on the total amount of the monomers. Further, the polymerization temperature is about 50 to 180 ° C, preferably 60 to 120 ° C. The reaction time is preferably 1 to 15 hours.

When the above-mentioned polar solvents such as alcohols, ketones, ethers and esters are used in combination in the non-aqueous solvent used in the reaction, or when the monomer (A) to be polymerized and granulated is not used. When the reactant remains, it is preferable to remove it by heating it to a boiling point of the solvent or the monomer or higher or distilling it off under reduced pressure.

As described above, the non-aqueous dispersed resin particles produced according to the present invention exhibit very stable dispersibility while existing as fine particles having a uniform particle size distribution.
In particular, even if the toner is repeatedly used for a long time in the developing device, the dispersibility is good and the re-dispersion is easy even if the developing speed is improved. 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.

As described above, the high redispersibility of the latex particles of the present invention depends on the star-type copolymer comprising a specific block used together with the insolubilizing monomer (A). That is, the dispersion stabilizing resin [P] of the present invention has a block B composed of a long-chain aliphatic group-containing polymer component having a high affinity for the non-aqueous solvent and a small affinity for the non-aqueous solvent. At least three or more polymer chains of an AB type block in which a block A composed of a polymer component having an affinity for the insolubilizing monomer (A) is bonded in an organic molecule, It is a star type copolymer. Thereby, the block A portion is sufficiently adsorbed by the physicochemical interaction at the time of polymerization granulation with respect to the dispersed resin particles, and the block B portion having a high affinity for the non-aqueous dispersion medium is formed with respect to the solvent. Since there are at least three or more polymer chains that sufficiently solvate and have a sufficient steric repulsion effect (so-called tail-like adsorption),
It is presumed that the effects of the present invention were achieved when the adsorption effect and the steric repulsion effect were expressed sufficiently and efficiently.

On the other hand, in a conventionally known random copolymer of the polymer component used in the block A and the polymer component used in the block B, a high-concentration component in which the component serving as the adsorbed portion is solvated is used. Adhesion to the dispersed resin particles is not sufficient because they are randomly bonded in the molecular chain, and furthermore, the adsorption pattern becomes a loop, so that the steric repulsion effect is also excluded, and the dispersion stability is sufficient. Was not. Further, A composed of block A and block B
A -B type block copolymer was developed, and the effect of improving dispersion stability was recognized as compared with the above random copolymer. However, in recent years, the effect of dispersion stability has not been sufficient for increasing the development speed of a plate making machine.

In addition, high printing durability that does not cause deterioration of the toner image area when printed as an offset master master is that the insolubilizable monomer (A) and the dispersed polymer adsorbed thereon have good compatibility with each other. It is presumed that this is achieved by sufficiently compatibilizing even under mild fixing conditions and forming a uniform and strong film.

A coloring agent may be used in the liquid developer of the present invention, if desired. 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,
And phthalocyanine blue. 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, another method is disclosed in
As disclosed in JP-A-54029, there is a method of chemically bonding a dispersing resin and a dye.
As described in, for example, 4-22955, 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 the charge characteristics or improving the image characteristics. For example, Yuji Harazaki, "Electrophotography", Vol. What is specifically described in No. 2, p. 44 is used. For example, di-2-ethylhexylsulfosuccinic acid metal salt, naphthenic acid metal salt, higher fatty acid metal salt, lecithin, poly (vinylpyrrolidone), a copolymer containing a semi-maleic acid amide component, higher alcohols having 8 or more carbon atoms, Examples include compounds such as polyethers and silicone oil.

The amounts of the main components of the liquid developer of the present invention will be described below. The toner particles mainly composed of a resin (and a coloring agent used as desired) are used in an amount of 0.5 parts by weight to 1000 parts by weight of the carrier liquid.
50 parts by weight are preferred. If the amount is less than 0.5 parts by weight, the image density becomes insufficient, and if it exceeds 50 parts by weight, fogging to a non-image portion is apt to occur. Further, the carrier liquid-soluble resin for stabilizing the dispersion is also used as desired, and about 0.5 to 100 parts by weight can be added to 1000 parts by weight of the carrier liquid. The charge control agent as described above is a carrier liquid 100
0.001 to 1.0 parts by weight per 0 parts by weight is preferred. If desired, various additives may be added. The upper limit of the total amount of these additives is regulated by the electric resistance of the developer. That is, if the electric resistance of the liquid developer from which the toner particles have been removed is lower than 10 ⁹ Ωcm, it becomes difficult to obtain a high-quality continuous tone image.
It is necessary to control within this limit.

[0056]

EXAMPLES The production examples of the dispersion stabilizing resin of the present invention, the production examples of latex particles and the examples are shown below, and the effects of the present invention will be described in more detail. However, the present invention is not limited to these examples. Absent.

Synthesis Example 1 of Resin [P] for Stabilizing Dispersion Resin [P-1] 50 g of methyl methacrylate, 50 g of methyl acrylate
g, a mixture of 7.8 g of an initiator [I-1] having the following structure and 100 g of tetrahydrofuran at a temperature of 50 ° C. under a nitrogen stream.
Was heated. This solution was added with a 400 W high-pressure mercury lamp at 10 c.
m for 8 hours through a glass filter from a distance of m for photopolymerization. The polymer was reprecipitated in 1 liter of methanol, and the precipitate was collected and dried. Next, the polymer 3
A mixed solution of 0 g, 70 g of stearyl methacrylate and 100 g of tetrahydrofuran was heated again to a temperature of 50 ° C. under a nitrogen stream. Next, after performing light irradiation for 16 hours in the same manner as described above, the obtained reaction product was treated with methanol 1.5 times.
The precipitate was collected in a liter, and the precipitate was collected and dried. The yield was 80 g, and the weight average molecular weight (Mw: Mw was a value determined by a GPC method in terms of polystyrene (GPC: size exclusion chromatography)) was 6 × 10 ^4. Was obtained.

[0058]

Embedded image

[0059]

Embedded image

Synthesis Examples 2 to 14 of Dispersion Stabilizing Resin [P]: Resins [P-2] to [P-14] In Synthesis Example 1 of dispersion stabilizing resin, initiator [I-1]
A polymer was synthesized in the same manner as in Synthesis Example 1 except that 0.011 mol of an initiator described in Table A below was used instead of
The Mw of each polymer obtained was in the range of 4 × 10 ^{4 to} 6 × 10 ⁴ .

[0061]

[Table 1]

[0062]

[Table 2]

[0063]

[Table 3]

[0064]

[Table 4]

Synthesis Examples 15 to 28 of Dispersion Stabilizing Resin [P]: Resins [P-15] to [P-28] Each monomer corresponding to the polymer component of block A shown in Table B below A mixture of 0.01 mol of the initiator [I-7] and 100 g of tetrahydrofuran was heated to 50 ° C. under a nitrogen stream with respect to all the monomers used. In this solution,
In the same manner as in Synthesis Example 1, light irradiation was performed for 12 hours to perform a polymerization reaction. Next, each of the obtained polymers was subjected to a predetermined amount (x: as solid content) shown in Table-B and each monomer corresponding to the polymer component of block B shown in Table-B below as Table-B
And a mixed solution to which tetrahydrofuran was added so that the concentration of all compounds was 60% by weight was again heated to a temperature of 55 ° C. under a nitrogen stream. Next, after performing light irradiation for 16 hours in the same manner as described above, the obtained reaction product was reprecipitated in 1.5 liters of methanol, and the precipitate was collected and dried. Yield 60-80
g of each polymer of 3 × 10 ^{4 to} 6 × 10 ⁴ was obtained.

[0066]

[Table 5]

[0067]

[Table 6]

[0068]

[Table 7]

[0069]

[Table 8]

Production Example 1 of Latex Particle 1: Latex Particle D-1 14 g of dispersion stabilizing resin [P-1] and 1 g of Isopar H
Temperature of 60 ° C. while stirring 77 g of the mixed solution under a nitrogen stream.
Was heated. 50 g of methyl methacrylate, 50 g of methyl acrylate, and 2,2′-azobis (isovaleronitrile) (abbreviated AIVN) as a polymerization initiator
A mixed solution of 0 g and 200 g of Isopar H was added dropwise over 2 hours, and the mixture was stirred for 2 hours. Further, A. I. V.
N. Was added and stirred for 3 hours. After cooling, the mixture was passed through a 200-mesh nylon cloth, and the resulting white dispersion was a latex having a polymerization rate of 95% and an average particle size of 0.20 μm. The particle size was measured with CAPA-500 (manufactured by Horiba, Ltd.).

Latex Particle Production Examples 2 to 11: Latex Particles D-2 to D-11 In the latex particle production example 1, the dispersion stability described in Table C below was used instead of the dispersion stabilizing resin [P-1]. Latex particles D-2 to D-11 of the present invention were produced in exactly the same manner as in Production Example 1 except that a resin for use was used. The polymerization rate of each of the obtained latex particles was 90 to 95%, the average particle size was in the range of 0.15 to 0.20 μm, and the monodispersity was good.

[0072]

[Table 9]

Production Example 12 of Latex Particles: Production of Latex Particles D-12 12 g of dispersion stabilizing resin [P-17] and vinyl acetate 10
A mixture of 0 g and 384 g of Isopar H was heated to a temperature of 70 ° C. while stirring under a nitrogen stream. As a polymerization initiator, A.I. I. V. N. Was added and reacted for 3 hours.
Twenty minutes after the initiator was added, cloudiness occurred, and the reaction temperature was 8
The temperature rose to 8 ° C. Further, after adding 0.5 g of an initiator and reacting for 2 hours, 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 200-mesh nylon cloth, and the resulting white dispersion was a latex having a conversion of 88% and an average particle size of 0.22 μm.

Latex Particle Production Examples 13 to 21: Latex Particles D-13 to D-21 Monomer (A) (that is, methyl methacrylate and methyl acrylate) used in Latex Particle Production Example 1 for dispersion stabilization Latex particles were produced in the same manner as in Production Example 1 except that the compounds shown in Table D below were used instead of the resin [P-1]. The polymerization rate of each of the obtained latex particles was 85 to 98%, the average particle size was in the range of 0.15 to 0.25 μm, and the monodispersity was good.

[0075]

[Table 10]

Production Example 22 of Latex Particles: (Comparative Example A) In Production Example 1 of latex particles, instead of 14 g of the dispersion stabilizing resin [P-1], a resin [RP-
1] Except that 30 g was used, the polymerization rate was 98% and the average particle diameter was 0.40 μm in the same manner as in Production Example 1 of latex particles.
A white dispersion as latex particles was obtained.

[0077]

Embedded image

Production Example 23 of Latex Particles: (Comparative Example B) In Production Example 1 of latex particles, instead of 14 g of the dispersion stabilizing resin [P-1], a resin [RP-
2] Except that 20 g was used, the polymerization rate was 90% and the average particle diameter was 0.30 μm in the same manner as in Production Example 1 for latex particles.
A white dispersion as latex particles was obtained. (Japanese Unexamined Patent Publication
(Equivalent to -225353)

[0079]

Embedded image

Production Example 24 of Latex Particles: (Comparative Example C) In Production Example 1 of latex particles, instead of 14 g of the dispersion stabilizing resin [P-1], a resin [RP-
3] Except that 20 g was used, the polymerization rate was 92% and the average particle diameter was 0.35 μm in the same manner as in Production Example 1 of latex particles.
A white dispersion as latex particles was obtained. (Japanese Unexamined Patent Publication
(Equivalent to -12666)

[0081]

Embedded image

Example 1 A paint shaker (manufactured by Tokyo Seiki Co., Ltd.) containing 10 g of dodecyl methacrylate / acrylic acid copolymer (copolymerization ratio: 95/5 by weight), 10 g of nigrosine and 30 g of Shellsol 71 together with glass beads. And dispersed for 4 hours to obtain a fine dispersion of nigrosine. 6 g (as solid content) of the resin particles of Production Example 1 of latex particles, 2.5 g of the above nigrosine dispersion, 15 g of FOC-1400 (tetradecyl alcohol, manufactured by Nissan Chemical Industries, Ltd.), and octadecene-hema maleic acid octadecylamide A liquid developer for electrostatography was prepared by diluting 0.08 g of the copolymer to 1 liter of Isopar G.

(Preparation of Comparative Developers A to C) Three kinds of liquid developers A, B and C for comparison were prepared by replacing the resin particles in the production of the above liquid developer with the following resin particles. Comparative liquid developer A: resin particles obtained in Production Example 22 of latex particles. Comparative liquid developer B: resin particles obtained in Production Example 23 of latex particles. Comparative liquid developer C: resin particles obtained in Production Example 24 of latex particles.

These liquid developers were used in a fully automatic plate making machine ELP.
An ELP Master II type (manufactured by Fuji Photo Film Co., Ltd.), which is an electrophotographic photosensitive material, was exposed and developed using a 404V (manufactured by Fuji Photo Film Co., Ltd.) developer.
The plate making speed was 4 plates / min. Further, after 2500 sheets of ELP Master II type were processed, the presence or absence of toner adhesion to the developing device was observed. The blackening rate (image area) of the copied image was determined using a 30% original. The results are shown in Table-E.

[0085]

[Table 11]

When plate making was performed using each developer under the above-described plate making conditions, the developer which did not cause staining of the developing device and had a clear image on the 2500th plate making plate was only in the case of the present invention. . On the other hand, a master plate for offset printing (ELP master) obtained by making a plate from each developer is printed by an ordinary method, and the number of printed sheets until the occurrence of missing characters, blurred solid portions, etc. in the printed image is compared. As a result, the master plate obtained using the developer of the present invention was 100
It did not occur even with more than 00 sheets, and occurred on 3000 sheets in the master plate using Comparative Example A. In the case of Comparative Example B, 7000 sheets were generated, and in the case of Comparative Example C, 6,000 sheets were generated. 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. In the case of Comparative Example B and Comparative Example C,
When used under severe plate making conditions (conventionally, the blackening rate of a copied image is about 8 to 10% at a plate making speed of 2 to 3 sheets / min), contamination of the developing device (especially on the back electrode plate) And the image quality of the copied image on the plate is affected after 2500 sheets (Dmax reduction, thin line blurring, etc.)
Came out. Also, the number of printed master plates was significantly reduced in Comparative Example A. These results
This shows that the resin particles of the present invention are clearly superior.

Example 2 White dispersion 10 obtained in Production Example 14 of latex particles
0 g and 1.5 g of Sumicalon Black at a temperature of 1
The mixture was heated to 00 ° C. and heated and stirred for 4 hours. After cooling to room temperature 2
By removing the remaining dye through a 00 mesh nylon cloth, a black resin dispersion having an average particle size of 0.24 μm was obtained. 32 g of the above black resin dispersion, 0.05 g of zirconium naphthenate, FOC-1600 (Nissan Chemical Co., Ltd.)
20 g of Hexadecyl alcohol)
A liquid developer was prepared by diluting 1 to 1 liter. When this was developed by the same device as in Example 1,
Even after the development of 2500 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 White dispersion 10 obtained in Production Example 16 of latex particles
0 g and 3 g of Victoria Blue B at a temperature of 7
The mixture was heated to 0 ° C to 80 ° C and stirred for 6 hours. After cooling to room temperature
The remaining dye was removed through a 200-mesh nylon cloth to obtain a blue resin dispersion having an average particle size of 0.23 μm. A liquid developer was prepared by diluting 32 g of the blue resin dispersion and 0.05 g of zirconium naphthenate to 1 liter of Isopar H. When this was developed with the same apparatus as in Example 1, no toner adhesion stains were seen on the apparatus even after 2500 sheets were developed. or,
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 32 obtained in Production Example 14 of latex particles
g, 2.5 g of the nigrosine dispersion obtained in Example 1, FOC
A liquid developer was prepared by diluting 20 g of -1400 (manufactured by Nissan Chemical Industries, Ltd., tetradecyl alcohol) and 0.02 g of a semi-docosanyl amidated copolymer of diisobutylene and maleic anhydride to 1 liter of Isopar G. did. When this was developed by the same apparatus as in Example 1, no toner adhesion stains were seen on the apparatus even after 2500 sheets were developed. Further, the image quality of the obtained master plate for offset printing and the image quality of the printed matter after printing 10,000 sheets 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 (decyl methacrylate), 30 g of Isopar H and 8 g of alkali blue were placed in a paint shaker together with glass beads and dispersed for 2 hours to obtain a fine dispersion of alkali blue. 30 g of the white resin dispersion D-12 obtained in Production Example 12 of latex particles, 4.2 g of the above-mentioned alkali blue dispersion, 15 g of isostearyl alcohol, and a half-docosanyl amidated product of a copolymer of diisobutylene and maleic anhydride 0 A liquid developer was prepared by diluting 0.06 g to 1 liter of Isopar G. When this was developed by the same apparatus as in Example 1, no toner adhesion stains were seen on the apparatus even after 2500 sheets were developed. 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 17 Liquid developers were prepared in the same manner as in Example 5 except that latex particles D-12 were replaced with the respective latexes shown in Table F below.

[0092]

[Table 12]

Each of the obtained liquid developers was used in an electrophotographic plate making system in the same manner as in Example 1 to examine the performance. Each liquid developer shows the same performance as in Example 1,
Both redispersibility and printing durability were good.

[0094]

According to the present invention, a liquid developer having excellent redispersibility, storage stability and stability, and excellent image reproducibility and fixability can be obtained. In particular, a liquid having excellent redispersibility and stability of particles even when the development-fixing process for an electrophotographic plate making system is accelerated, and excellent printing durability even when a large-size master plate is used. A developer was obtained.

Claims (2)

(57) [Claims] 1. A liquid developer for electrophotography comprising at least resin particles dispersed in a non-aqueous solvent having an electric resistance of not less than 10 ⁹ Ωcm and a dielectric constant of not more than 3.5. At least one monofunctional monomer (A) that is soluble in an aqueous solvent but insoluble by polymerization;
And phosphono group, carboxyl group, sulfo group, hydroxyl group, formyl group, amino group, -P (= O) (OH)
R ¹ group [R ¹ represents a -R ² group or -OR ² group, R ²
Represents a hydrocarbon group], -CONR ³ R ⁴ group, -SO ₂
A polymer component containing an NR ³ R ⁴ group (R ³ and R ⁴ each independently represent a hydrogen atom or a hydrocarbon group) and at least one polar group selected from cyclic acid anhydride-containing groups And / or a block A containing at least one polymer component corresponding to the monofunctional monomer (A) and a block B containing at least one polymer component represented by the following general formula (I). A to B type block polymer chain is formed by bonding at least three organic molecules,
The B-type block polymer chain is bonded to the organic molecule at one end of the polymer main chain of the block A opposite to the end bonded to the block B, and has a weight average molecular weight of 2 ×
A polymer resin particle obtained by polymerizing a mixture containing at least one kind of a dispersion stabilizing resin [P] composed of a star copolymer, which is 10 ⁴ to 1 × 10 ^6. Characteristic liquid developer for electrostatography. Embedded image In the general formula (I), X ¹ is -COO-, -OCO-,-
_{(CH 2) x COO -,} - (CH 2) [here x represents an integer of 1 to 3] _x OCO-, or an -O-. Y ¹
Represents an aliphatic group having 8 or more 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, —COO-Z ¹ , or —COO-Z ¹ via a hydrocarbon group (here, Z ¹ represents a hydrogen atom or an optionally substituted hydrocarbon group). 2. In the dispersion stabilizing resin [P], each block of the AB block copolymer component constituting each polymer chain has a block A / block B ratio of 1 to 50.
The liquid developer for electrostatography according to claim 1, wherein the liquid developer has a weight ratio of / 99 to 50 (weight ratio).