JPH087470B2 - 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 control agent such as a polymer containing metal soap, lecithin, linseed oil, higher aliphatic, and vinylpyrrolidone. is there.

In such a developer, the resin is dispersed as insoluble latex particles in the form of particles having a diameter of several nm to several hundred nm.
In the conventional liquid developer, the soluble dispersion stabilizing resin and the polarity controlling agent were easily diffused into the solution due to insufficient bonding between the soluble dispersion stabilizing resin and the polarity controlling agent and the insoluble latex particles. For this reason, there has been a defect 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. Further, since particles once aggregated and accumulated are difficult to redisperse, the particles remain attached to various parts of the developing machine, leading to the failure of the developing machine such as dirt on the image area and clogging of the 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 are significant restrictions on the combination of the dispersion stabilizer used and the insolubilizing monomer, and generally, The particles have a wide particle size distribution and contain a large amount of coarse particles, or are polydisperse particles having two or more average particle sizes. 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 dispersed resin particles of a copolymer of an insolubilizing monomer and a monomer containing a long-chain alkyl moiety or a monomer containing two or more polar components, The method for improving the dispersity, redispersibility, and storage stability of the particles is disclosed in JP-A-60-179751 and JP-A-62-15.
It is disclosed in 1868 and the like. In addition, in the presence of a polymer using a bifunctional monomer or a polymer using a polymer reaction, an insoluble dispersed resin particle of a copolymer of an insolubilizing monomer and a monomer containing a long-chain alkyl moiety is prepared. Thus, methods for improving the dispersibility, redispersibility and storage stability of particles are disclosed in JP-A-60-185963 and 61-63855.

(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. In addition, the operation time of the electrophotographic plate making system has been shortened, and the development-fixing process has been speeded up.

JP-A-60-179751, Simultaneous 62-151868, and 60-
No. 185963, No. 61-63855, the dispersed resin particles produced according to the means, when the development speed is increased, in terms of dispersibility and redispersibility of the particles, and when the fixing time is shortened. Alternatively, in the case of a master plate having a large plate size (for example, A-3 size or more), 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.

Another object of the present invention is to provide a liquid developer which enables the production of an offset printing original plate 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 have an electric resistance of 10 ⁹ Ωcm or more and a dielectric constant.
In a liquid developer for electrostatic photography, which comprises at least a resin dispersed in a non-aqueous solvent of 3.5 or less, the dispersed resin particles are mainly composed of a polymer having at least one repeating unit represented by the following general formula (I). It is soluble in the non-aqueous solvent in the presence of a dispersion stabilizing resin having a polymerizable double bond group capable of copolymerizing with the monofunctional monomer (A) bonded to only one end of the chain. However, a monofunctional monomer (A) that is insolubilized by polymerization and the following general formula (I
Polymerizing a solution represented by I) containing at least one monomer (B) containing an aliphatic group having 8 or more carbon atoms and capable of undergoing copolymerization with the monomer (A) by a polymerization reaction. This is achieved by a liquid developer for electrostatic photography, which is a copolymer resin particle obtained by reacting.

General formula (I) In the general formula (I), X is -COO -, - OCO -, - CH 2 OCO
_{-, - CH 2 COO -,} - O-, or -SO ₂ - represent.

R ¹ represents an aliphatic group having 6 to 32 carbon atoms.

a ¹ and a ² may be the same as 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. Through -COO-R ² (R ² represents a hydrocarbon group having 1 to 22 carbon atoms).

General formula (II) In the general formula (II), R ³ represents an aliphatic group having 8 or more carbon atoms.

Y is -COO-, -CONH-, (R ⁴ represents an aliphatic group), —OCO—, —CH ₂ COO—, or —O—.

b ₁ and b ₂ may be the same or different and each represents a hydrogen atom, an alkyl group, —COOR ⁵ or —CH ₂ —COOR ⁵ (R ⁵ represents an aliphatic group).

 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 their halogen-substituted products. 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), Cielsol 70, Cielsol 71
(Cielsol; trade name of Cieloil), Amsco
OMS, Amsco 460 solvent (Amsco; trade name of Spirits), etc. are 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)
In the presence of a dispersion-stabilizing resin obtained by bonding a polymerizable double bond group capable of copolymerizing with the monofunctional monomer (A) to only one end of the polymer main chain in a non-aqueous solvent. In addition, the monofunctional monomer (A) and the monomer (B) having an aliphatic group having 8 or more carbon atoms are copolymerized and polymerized and granulated.

Here, as the non-aqueous solvent, basically any solvent can be used as long as it is miscible with the carrier liquid of the liquid developer for electrostatic photography.

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 group hydrocarbon, alicyclic hydrocarbon, or aromatic hydrocarbon. Examples thereof include hydrogen and halogen substitution products thereof. For example, hexane, octane, isooctane, decane, isodecane, decalin, nonane, dodecane, isododecane, Isopar E, Isopar G, Isopar H, Isopar L, Cielsol 70, Cielsol 71, Amsco OMS, Amsco 460 solvent and the like, alone or in combination. To use.

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 acid esters (eg methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, propione) Acid ethyl etc.), ethers (eg diethyl ether, dipropyl ether, tetrahydrofuran, dioxane etc.), halogenated hydrocarbons (eg methylene dichloride, chloroform, carbon tetrachloride, dichloroethane, etc.)
Methyl chloroform, etc.).

The non-aqueous solvent used as a mixture of these, after the 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 developer, there is a problem if 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 in the step of producing the resin dispersion, and as described above, a linear or branched aliphatic hydrocarbon, alicyclic hydrocarbon, aromatic hydrocarbon, halogenated Hydrocarbons and the like.

The solvent-insoluble copolymer produced by copolymerizing a monofunctional monomer (A) and a monomer (B) having an aliphatic group having 8 or more carbon atoms in a non-aqueous solvent is The dispersion stabilizing resin of the present invention used to obtain a resin dispersion has a general formula (I)
Is a polymer having a polymerizable double bond group copolymerizable with the monofunctional monomer (A) bonded to only one end of the polymer main chain containing at least one repeating unit represented by.

In the repeating unit represented by the general formula (I), the aliphatic group or the hydrocarbon group may be substituted.

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

R ¹ preferably represents an optionally substituted alkyl group, alkenyl group or aralkyl group having 8 to 22 carbon atoms. As the substituent, for example, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, etc.), —O—R ⁶ , —COO—
^{R 6, -OCO-R 6 (} R 6 represents an alkyl group having 6 to 22 carbon atoms, e.g., hexyl, octyl, decyl, dodecyl, hexadecyl group, octadecyl group, etc.)
And the like. More preferably, R ¹ represents an alkyl group or an alkenyl group having 8 to 22 carbon atoms. Examples thereof include an octyl group, a decyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a hexadecyl group, an octadecyl group, a docosanyl group, an octenyl group, a decenyl group, a dodecenyl group, a tetradecenyl group and an octadecenyl group.

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 fluorine atom, a chlorine atom, a bromine atom, etc.), a cyano group, and a carbon number of 1 to 3.
Alkyl group, -COO-R ² or ^{_{-CH 2 COO-R 2 (R}} 2 preferably represents an aliphatic group having 1 to 18 carbon atoms). More preferably, a ₁ and a ₂ may be the same or different from each other, and are a hydrogen atom, an alkyl group having 1 to 3 carbon atoms (for example, methyl group, ethyl group, propyl group, etc.), —COO—R ² or -C
H ₂ COO-R ² (R ² more preferably represents an alkyl group or an alkenyl group having 1 to 18 carbon atoms, for example, methyl group, ethyl group, propyl group, butyl group, hexyl group, octyl group, decyl group, Dodecyl group, tridecyl group, tetradecyl group, hexadecyl group, octadecyl group, butenyl group,
Examples thereof include a hexenyl group, an octenyl group, a decenyl group, a dodecenyl group, a tetradecenyl group and an octadecenyl group. These alkyl group and alkenyl group may have the same substituents as those represented by R ¹ .

The polymerizable double bond group bonded to one end of the polymer main chain is a group copolymerizable with the monofunctional monomer (A), and specifically, CH ₂ = CH-CONH-, _{CH 2 = CH-CH 2 -NHCO-} , CH 2 = CH-SO 2 -, _{CH 2 = CH-O-, CH} 2 = CH-S-, CH 2 = CH-, CH 2 = CH-CH 2 -, and the like.

These polymerizable double bond groups have a chemical structure in which they are directly bonded to one end of the polymer main chain or bonded through an arbitrary linking group.

As the linking group, carbon-carbon bond (single bond or double bond), carbon-hetero atom bond (as a hetero atom, for example, oxygen atom, sulfur atom, nitrogen atom, silicon atom, etc.), hetero atom-hetero atom bond It is composed of any combination of atomic groups. For example [R ⁷ and R ⁸ represent a hydrogen atom, a halogen atom (eg, fluorine atom, chlorine atom, bromine atom, etc.), cyano group, hydroxyl group, alkyl group (eg, methyl group, ethyl group, propyl group, etc.), etc. ], CH = CH, -O-, -S-, −COO−, −SO ₂ −, -NHCOO-, -NHCONH-, [R ⁹ and R ¹⁰ are hydrogen atoms, R ^{2 represented} by the general formula (I) above.
And a linking group composed of a single linking group selected from an atomic group such as

The polymer component of the dispersion stabilizing resin of the present invention is a homopolymer or copolymer component selected from the repeating units represented by the general formula (I) or the repeating unit represented by the general formula (I). It is composed of a copolymer component obtained by polymerizing a corresponding monomer and another polymerizable monomer. Examples of the other monomer serving as the copolymer component together with the polymer component of the general formula (I) include the following general formula (III)
The compound shown by is mentioned.

General formula (III) In the general formula (III), T is -COO -, - OCO -, - CH 2 OCO
_{-, - CH 2 COO -,} - O-, Represents Here, R ¹² is a hydrogen atom or an optionally substituted aliphatic group having 1 to 18 carbon atoms (for example, methyl group, ethyl group, propyl group, butyl group, 2-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. R ¹¹ represents a hydrogen atom or an optionally substituted aliphatic group having 1 to 6 carbon atoms (eg, methyl group, ethyl group, propyl group,
Butyl group, 2-chloroethyl group, 2,2-dichloroethyl group, 2,2,2-trifluoroethyl group, 2-bromoethyl group, 2-glycidylethyl group, 2-hydroxyethyl group, 2-hydroxypropyl group, 2,3-dihydroxyethyl 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 and the like).

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

Specific examples of the monomer represented by the general formula (III) 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, Alkyl esters or amides of unsaturated carboxylic acid such as maleic acid having 1 to 4 carbon atoms which may be substituted (for example, methyl group, ethyl group, propyl group, butyl group, 2-chloroethyl group, 2- 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-carboxamidoethyl group, etc.), styrene derivative (eg, styrene, vinyl) Toluene, α-methylstyrene, vinylnaphthalene, chlorostyrene, dichlorostyrene, bromostyrene, vinylbenzenecarboxylic acid, vinylbenzenesulfonic acid, chloromethylstyrene, hydroxymethylstyrene, methoxymethylstyrene, N, N-dimethylaminomethylstyrene, Vinylbenzene carboxamide,
Vinylbenzenesulfonamide etc.), unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid or maleic acid, cyclic anhydrides of itaconic acid, acrylonitrile, methacrylonitrile, polymerizable double bond groups A heterocyclic compound containing (specifically, for example,
Compounds described in "Polymer Data Handbook-Basic Edition", p175-184, Baifukan (1986), edited by Japan Society of Polymer Science, for example, N-vinylpyridine, N-vinylimidazole, N-vinylpyrrolidone, vinylthiophene, Vinyltetrahydrofuran, vinyloxazoline, vinylthiazole, N-vinylmorpholine, etc.) and the like.

Two or more kinds of the monomers represented by the general formula (III) may be used in combination.

The repeating unit represented by the general formula (I) is used in an amount of 30% by weight or less in the dispersion stabilizing resin polymer used in the present invention.
100% by weight is suitable, and preferably 50% by weight to 100% by weight. The dispersion stabilizing resin of the present invention comprising a polymerizable double bond group bonded to only one end of the polymer main chain is conventionally known. Of the living polymer obtained by the anionic or cationic polymerization of the above-mentioned are reacted with a reagent containing various double bond groups, or a "specific reactive group" (for example, -OH, -COOH) is added to the end of the living polymer. , -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 reacted by a synthetic method such as a method of introducing a polymerizable double bond group by conducting a polymer reaction using a “specific reactive group” bonded only to one end of the polymerizable main chain. Can be manufactured.

Specifically, P.Dreyfuss & RPQuirk, Encycl.Poly
m.Sci.Eng., 7 , 551 (1987), Yoshiki Nakajo, Tatsuya Yamashita,
"Dyes and Chemicals", 30 , 232 (1985), Akira Ueda, Susumu Nagai,
"Science and Industry", 60, 57 (1986), PFRempp & E.Fran
ta, Advances in Polymer Science, 58 , 1 (1984), Koichi Ito, "Polymer Processing", 35 , 262 (1986), V.Percec, App
It can be produced according to the methods described in the review articles such as lied Polymer Science, 285 , 97 (1984) and the references cited therein.

The dispersion stabilizing resin used in the present invention has a weight average molecular weight of 1
× 10 ^{4 to} 5 × 10 ⁵ are preferable, and more preferably 2 × 10 ⁴ to
It is 2 × 10 ⁵ .

Specific examples of the dispersion stabilizing resin used in the present invention are shown below, but the present invention is not limited thereto.

Monomers used in producing the non-aqueous dispersion resin,
A monofunctional monomer (A) which is soluble in the non-aqueous solvent but insolubilized by polymerization; and a monofunctional monomer (C) having an aliphatic group having 8 or more carbon atoms represented by the general formula (II). The monomer (B) which can be copolymerized with the monomer (A) can be distinguished.

The monomer (A) in the present invention may be any monofunctional monomer which is soluble in a non-aqueous solvent but insolubilized by polymerization. Specific examples include a monomer represented by the general formula (IV).

General formula (IV) In the general formula (IV), Q is -COO -, - OCO -, - CH 2 OCO-, -CH 2 COO -, - O-, Represents Here, R ¹⁴ is a hydrogen atom or an optionally substituted aliphatic group having 1 to 18 carbon atoms (for example, methyl group, ethyl group, propyl group, butyl group, 2-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 A 3-methoxypropyl group).

R ¹³ is a hydrogen atom or an optionally substituted aliphatic group having 1 to 6 carbon atoms (eg, methyl group, ethyl group, propyl group,
Butyl group, 2-chloroethyl group, 2,2-dichloroethyl group, 2,2,2-trifluoroethyl group, 2-bromoethyl group, 2-glycidylethyl group, 2-hydroxyethyl group, 2-hydroxypropyl group, 2,3-dihydroxyethyl 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 and the like).

e ¹ and e ² may be the same or different and each has the same meaning as a ¹ or a ² in the general formula (I).

Specific monofunctional monomers (A) include, for example, aliphatic carboxylic acids having 1 to 6 carbon atoms (acetic acid, propionic acid,
(Butyric acid, monochloroacetic acid, trifluoropropionic acid, etc.) vinyl esters or allyl esters, acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, etc. Good alkyl esters or amides (as the alkyl group, for example, methyl group, ethyl group, propyl group, butyl group,
2-chloroethyl group, 2-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-carboxamidoethyl group, etc.), styrene derivative (for example, styrene, vinyltoluene, α-methylstyrene, vinylnaphthalene, chlorostyrene, dichlorostyrene, bromo). Styrene, vinylbenzenecarboxylic acid, vinylbenzenesulfonic acid, chloromethylstyrene, hydroxymethylstyrene, methoxymethylstyrene, N, N-dimethylaminomethylstyrene, vinylbenzenecarboxamide, vinylbenzenesulfoamide, etc.), acrylic acid, methacrylic acid , Unsaturated carboxylic acids such as crotonic acid, maleic acid, itaconic acid or maleic acid, cyclic anhydrides of itaconic acid, acrylonitrile, methacrylonitrile, heterocyclic compounds containing a polymerizable double bond group (tool Thereof include, for example, the Society of Polymer Science, ed., "Polymer Data Handbook - Fundamentals -", p175~18
4. Compounds described in Baifukan (1986), for example, N-
Vinylpyridine, N-vinylimidazole, N-vinylpyrrolidone, vinylthiophene, vinyltetrahydrofuran, vinyloxazoline, vinylthiazole, N-vinylmorpholine and the like.

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

Next, the monomer (B) represented by the general formula (II) used in the present invention will be further described.

In the general formula (II), preferably R ³ represents an optionally substituted alkyl group having 10 or more total carbon atoms or an alkenyl group having 10 or more total carbon atoms, and Y represents —COO—, —CONH—, [However, R ⁴ preferably represents an aliphatic group having 1 to 32 carbon atoms (the aliphatic group represents, for example, an alkyl group, an alkenyl group or an aralkyl group)], -OCO-, -CH ₂ OCO- or Represents -O-. b ¹ and b ² may be the same or different, preferably a hydrogen atom, a methyl group, -COOR ⁵ or -C.
H ₂ COOR ⁵ (wherein R ⁵ is preferably an alkyl group having 1 to 32 carbon atoms, an alkenyl group, an aralkyl group or a cycloalkyl group).

Still more preferably, in the formula (II), Y is -COO-,
-CONH- or And b ¹ and b ^{2, which} may be the same or different, each represents a hydrogen atom or a methyl group, and R ³ has the same meaning as described above.

Specific examples of the monomer (B) represented by the above general formula (II) include an aliphatic group having a total carbon number of 10 to 32 (the aliphatic group is a halogen atom, a hydroxyl group, an amino group, an alkoxy group, etc. Or a hetero atom such as an oxygen atom, a sulfur atom or a nitrogen atom, which is a carbon atom of the main chain of
Ester acids of unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid having a carbon bond (may be a decyl group, dodecyl group, tridecyl group, tetradecyl group as an aliphatic group) Group, hexadecyl group, octadecyl group, docosanyl group,
Dodecenyl group, hexadecenyl group, oleyl group, linoleyl group, dococenyl group, etc.), amides of unsaturated carboxylic acid described above (aliphatic groups represent the same as those shown for esters), vinyl esters of higher fatty acids or Allyl esters (as higher fatty acids, for example, lauric acid, myristic acid, stearic acid, oleic acid, linoleic acid, behenic acid, etc.), or vinyl ethers substituted with an aliphatic group having 10 to 32 carbon atoms (aliphatic group) Represents the same range as the aliphatic group of the unsaturated carboxylic acid) and the like.

The dispersing resin of the present invention comprises at least one kind of each of the monomer (A) and the monomer (B). What is important is that the resin synthesized from these monomers is insoluble in the non-aqueous solvent. If so, a desired dispersion resin can be obtained. More specifically, the monomer (B) represented by the general formula (II) is preferably used in an amount of 0.1 to 20% by weight, more preferably 0.3 to 8% by weight, based on the monomer (A) to be insolubilized. % By weight. The molecular weight of the dispersion resin of the present invention is preferably 10 ³ to 10 ⁶ , more preferably 10 ⁴ to 10 ⁶ .

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 benzoyl peroxide in the monomer (B) and a non-aqueous solvent,
The heat polymerization may be carried out in the presence of a polymerization initiator such as azobisisobutyronitrile or butyllithium.

Specifically, a dispersion stabilizing resin, a method of adding a polymerization initiator to a mixed solution of a monomer (A) and a monomer (B), and a monomer ( A) and the monomer (B) are added dropwise together with the polymerization initiator, or a mixed solution containing the total amount of the dispersion stabilizing resin and a part of the mixture of the monomer (A) and the monomer (B). Inside, a method of optionally adding the remaining monomer mixture together with the polymerization initiator, and further, in a non-aqueous solvent, a mixed solution of the dispersion stabilizing resin and the monomer is optionally added together with the polymerization initiator. There is a method, etc., and any method can be used for production.

The total amount of the monomers (A) and (B) is
5 to 80 parts by weight with respect to 0 parts by weight, preferably 10
~ 50 parts by weight.

The soluble resin which is 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 0.1 to 5% (weight) of the total amount of the monomers.
Is appropriate.

The polymerization temperature is about 50 to 180 ° C, preferably 6
0-120 ° C. The reaction time is preferably 1 to 15 hours.

In the non-aqueous solvent used in the reaction, the alcohols described above,
When polar solvents such as ketones, ethers and esters are used in combination, or when unreacted monomer (A) or monomer (B) to be polymerized and granulated remains, the solvent or monomer may be used. It is preferred to remove by heating to a temperature higher than the boiling point of the body or distilling it off or by distilling it off under reduced pressure.

Non-aqueous latex particles produced as described above,
Existence of fine and uniform particle size distribution and very stable dispersibility.Especially, even if used repeatedly for a long time in the developing device, good dispersibility and re-dispersion even if development speed is improved. This is also easy, and it is not recognized at all that any contamination occurs on each part of the apparatus.

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

Furthermore, the liquid developer of the present invention is excellent in dispersion stability, redispersibility and fixability even when the development-fixing process is accelerated and a large size master plate is used.

A colorant may be used in the liquid developer of the present invention if necessary.

The colorant is not particularly limited, and various conventionally known pigments or dyes can be used.

When the dispersed resin itself is colored, for example, as one of coloring methods, there is a method of physically dispersing it in a dispersed resin by using a pigment or a dye, and many pigments or dyes to be used are known. There is. 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 of chemically bonding a disperse resin and a dye, as disclosed in JP-A-53-54029, or JP-B-44-44.
As described in No. 22955 and the like, there is a method in which a dye-containing monomer is used to prepare a dye-containing copolymer when it is produced by a polymerization granulation method.

In the liquid developer of the present invention, various additives may be added as necessary for the purpose of enhancing charging characteristics or improving image characteristics, for example, Yuji Harazaki "Electrophotography" Vol. 16,
No. 2, page 44 is used.

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

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

Toner particles mainly composed of a resin and optionally a coloring agent are contained in an amount of 0.5 to 50 parts by weight per 1000 parts by weight of the carrier liquid.
Parts by weight are preferred. If it is less than 0.5 parts by weight, the image density is insufficient, and if it exceeds 50 parts by weight, fog is easily generated on the non-image area. Further, the carrier liquid soluble resin for dispersion stabilization described above is also used if necessary, and relative to 1000 parts by weight of the carrier liquid.
About 0.5 to 100 parts by weight can be added. The charge control agent as described above is 0.001 with respect to 1000 parts by weight of the carrier liquid.
Part by weight to 1.0 part by weight is preferred. Further, various additives may be added if necessary, and the upper limit of the total amount of these additives is restricted by the electric resistance of the developer. That is, the electric resistance of the liquid developer from which the toner particles have been removed is 10 ⁹ Ωc
If it is less than m, it becomes difficult to obtain a good quality continuous tone image, so it is necessary to control the amount of each additive within this limit.

(Examples) Examples of the present invention will be illustrated below, but the present invention is not limited thereto.

Production Example of Dispersion Stabilizing Resin 1: Production of Dispersion Stabilizing Resin P-1 A mixed solution of 100 g of octadecyl methacrylate, 150 g of toluene and 50 g of isopropanol was heated to 75 ° C. while stirring under a nitrogen stream. 30 g of 2,2'-azobis (4-cyanovaleric acid) (abbreviation ACV) was added and reacted for 8 hours.
After cooling, the precipitate was reprecipitated in 2 l of methanol, and the white powder was collected by filtration and dried. A mixture of 50 g of the obtained white powder, 3.3 g of vinyl acetate, 0.025 g of mercury acetate, 0.2 g of hydroquinone and 100 g of toluene was heated to a temperature of 40 ° C. and reacted for 2 hours. Next, the temperature was raised to 70 ° C., 3.8 × 10 ⁻³ ml of 100% sulfuric acid was added, and the mixture was reacted for 10 hours. Cooled to 25 ℃, sodium acetate trihydrate
After adding 0.02 g and stirring for 30 minutes, it was reprecipitated in methanol 1 and a slightly fading powder was collected by filtration and dried. Yield 41g
And the weight average molecular weight (w) was 38,000.

Production Examples 2-9 of Dispersion Stabilizing Resin: Dispersion Stabilizing Resin P-2
Production of P-9 Each dispersion stabilizing resin was produced in the same manner as in Production Example 1 except that the monomers in Table 1 below were used instead of octadecyl methacrylate.

Production Example 10 of dispersion stabilizing resin: Production of dispersion stabilizing resin P-10 A polymerization reaction was carried out in the same manner as in Production Example 1 except that a mixed solution of 100 g of dodecyl methacrylate, 150 g of toluene and 50 g of isopropanol was used. After cooling, it was reprecipitated in 2 l of methanol to obtain a colorless and transparent viscous substance by a decantation method, and then dried. A mixture of 50 g of the obtained viscous product, 1.5 g of glycidyl methacrylate, 1.0 g of 2,2'-methylenebis- (6-t-butyl-p-cresol), 0.5 g of N, N-dimethyldodecylamine and 100 g of toluene was added. The temperature was raised to 100 ° C. and the mixture was stirred for 12 hours. This reaction mixture was added to methanol 1
After reprecipitation, a pale yellow viscous substance was obtained by a decantation method and then dried. The yield was 39 g and w37,000.

Production Example 11 of dispersion stabilizing resin: Production of dispersion stabilizing resin P-11 A mixed solution of 100 g of octadecyl methacrylate and 300 g of toluene was heated to 70 ° C while stirring under a nitrogen stream. 5 g of 4,4'-azobis (4-cyanopentanol) was added and reacted for 8 hours. Next, after cooling the reaction product, 6.2 g of methacrylic anhydride, 0.8 g of t-butylhydroquinone and 1 drop of concentrated sulfuric acid were added, and the mixture was stirred at 30 ° C. for 1 hour.
The mixture was stirred at 50 ° C for 3 hours. After cooling, it was reprecipitated in 2 l of methanol, and a white powder was collected by filtration and dried. The yield was 88 g and w38,000.

Production Example 12 of dispersion stabilizing resin: Production of dispersion stabilizing resin P-12 A mixed solution of 100 g of octadecyl methacrylate and 200 g of tetrahydrofuran was stirred at a temperature of 70 ° C under a nitrogen stream.
Warmed to. 4,4'-Azobis (4-cyanopentanol) 4g was added and reacted for 5 hours. Furthermore, the azobis compound
1.0 g was added and reacted for 5 hours. The reaction mixture was cooled to a temperature of 20 ° C. in a water bath, and 3.2 g of pyridine and 1.0 g of 2,2′-methylenebis- (6-t-butyl-p-cresol) were added and stirred. Methacrylic acid chloride was added to this mixed solution.
4.2 g 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 mixture of 1.5 l of methanol and 0.5 l of water, and a white powder was collected by filtration and dried. The yield was 86 g and w33,000.

Production Examples 13-21 of Dispersion Stabilizing Resin: Dispersion Stabilizing Resin P-13
-Manufacture of P-21 In Production Example 12, each dispersion stabilizing resin was produced in the same manner as in Production Example 12 except that the acid chloride shown in Table 2 below was used instead of methacrylic acid chloride.

Production Example 22 of dispersion stabilizing resin: Production of dispersion stabilizing resin P-22 Dodecyl methacrylate 98.5 g, thioglycolic acid 1.5
g and toluene 200g mixed solution under nitrogen stream at temperature 70 ℃
Warmed to. 1,1'-azobis (cyclohexane-1-
0.5 g of carbonitrile) was added and the mixture was reacted for 5 hours, 0.5 g of the azobis compound was added, and the mixture was reacted for 5 hours. Glycidyl methacrylate (3.0 g), t-butylhydroquinone (1.0 g) and N, N-dimethylaniline (0.6 g) were added to the reaction product, and the mixture was reacted at a temperature of 110 ° C. for 8 hours. After cooling, the precipitate was reprecipitated in 2 l of methanol to obtain a pale yellow viscous substance by decantation, and then dried. The yield was 80 g and w was 33,000.

Production Example 23 of dispersion stabilizing resin: Production of dispersion stabilizing resin P-23 A mixed solution of 98.5 g of hexadecyl methacrylate, 1.5 g of 2-mercaptoethylamine and 200 g of tetrahydrofuran was heated to a temperature of 80 ° C under a nitrogen stream. 0.3g of 1,1'-azobis (cyclohexane-1-carbonitrile) was added and reacted for 5 hours, and further 0.3g of the above azobis compound was added and reacted for 5 hours. Add 2.5 g of acrylic anhydride, 2,
1.0 g of 2'-methylenebis- (6-t-butyl-p-cresol) was added, and the mixture was stirred at a temperature of 40 ° C for 5 hours. After cooling, the reaction product was reprecipitated in 2 l of methanol to obtain a colorless viscous product.
The yield was 82 g and w was 20,000.

Production Example 24 of dispersion stabilizing resin: Production of dispersion stabilizing resin P-24 100 g of dodecyl methacrylate and tetrahydrofuran
200 g of the mixed solution was heated to a temperature of 65 ° C. under a nitrogen stream. 2,
6 g of 2'-azobis (4-cyanovaleric acid chloride) was added and stirred for 10 hours. This 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. Pyridine
2.5 g was added dropwise so that the reaction temperature did not exceed 25 ° C., and the mixture was stirred for 1 hour. After further stirring at a temperature of 40 ° C. for 2 hours, the mixture was reprecipitated in 2 l of methanol. After obtaining a pale yellow viscous substance by decantation, it was dried. The yield was 80 and w was 38,000.

Production Example 1 of Latex Particles 1: Production of Latex Particles D-1 A mixed solution of 12 g of dispersion stabilizing resin P-1, 100 g of vinyl acetate, 1.0 g of octadecyl methacrylate and 384 g of Isopar H was heated to 70 ° C. while stirring under a nitrogen stream. Warmed.
2,2'-azobis (isovaleronitrile) (abbreviation AIV
N.) was added and reacted for 6 hours. Twenty minutes after the addition of the initiator, white turbidity occurred and the reaction temperature rose to 88 ° C. Temperature 100
C. and stirred for 2 hours to remove unreacted vinyl acetate.
After cooling, the white dispersion obtained by passing through a 200-mesh nylon cloth was a latex having a polymerization rate of 90% and an average particle size of 0.24 μm.

Latex Particle Production Examples 2 to 12: Latex Particle D-2
-Production of D-12 In Production Example 1 of latex particles, the procedure of Production Example 1 was repeated except that the resin for dispersion stabilization shown in Table 3 below was used in place of Resin P-1. Latex particles D-2 to D-12 were produced.

Production Examples 13-18 of Latex Particles: Latex Particles D-13
Production of D-18 Each latex particle was produced in the same manner as in Production Example 1 except that 1 g of each monomer in Table 4 was used in place of 1 g of octadecyl methacrylate in the production example of latex particles D-1. did.

Production Example 19 of Latex Particles: Production of Latex Particles D-19 A mixed solution of 6 g of dispersion stabilizing resin P-10, 8 g of poly (octadecyl methacrylate), 100 g of vinyl acetate, 0.8 g of dodecyl methacrylate and 400 g of Isopar H was stirred under a nitrogen stream. While heating to a temperature of 75 ° C. 0.7 g of 2,2'-azobis (isobutylnitrile) (abbreviated AIBN)
After reacting for 0.5 hour, 0.5 g of AIBN was added and reacted for 2 hours. After cooling, the white dispersion obtained by passing through a 200-mesh nylon cloth was a latex having an average particle size of 0.17 μm.

Production Example 20 of Latex Particles: Production of Latex Particles D-20 10 g of dispersion stabilizing resin P-11, 90 g of vinyl acetate, 10 g of N-vinylpyrrolidone, 1.5 g of octadecyl methacrylate.
And a mixed solution of 400 g of isododecane was heated to a temperature of 65 ° C. while stirring under a nitrogen stream. 1.5 g of AIBN was added and reacted for 4 hours. After cooling, the white dispersion obtained by passing through a 200-mesh nylon cloth was a latex having an average particle size of 0.25 μm.

Production Example 21 of Latex Particles: Production of Latex Particles D-21 20 g of dispersion stabilizing resin P-1, 94 g of vinyl acetate, 6 g of crotonic acid, 2 g of hexadecyl methacrylate and 2 g of Isobar G were stirred under a nitrogen gas stream while stirring. Heated to 60 ° C. AIVN (1.0 g) was added and reacted for 2 hours. Further AIV
0.5 g of N. was added and reacted for 2 hours. After cooling, the white dispersion obtained by passing through a 200-mesh nylon cloth has an average particle size of 0.28μ.
m latex.

Production Example 22 of Latex Particles: Production of Latex Particles D-22 25 g of dispersion stabilizing resin P-16, methyl methacrylate 1
A mixed solution of 00 g, decyl methacrylate 2 g, and Isopar H was heated to a temperature of 60 ° C. while stirring under a nitrogen stream.
0.7 g of AIVN was added and reacted for 4 hours. After cooling, the white dispersion obtained by passing through a 200-mesh nylon cloth had an average particle size of 0.
It was a 38 μm latex.

Production Example 23 of Latex Particles: Production of Latex Particles D-23 A mixed solution of 25 g of dispersion stabilizing resin P-15, 100 g of styrene, 2 g of octadecyl vinyl ether and 380 g of Isopar H was heated to 45 ° C while stirring under a nitrogen stream. . n-
A hexane solution of butyllithium was added in an amount of 1.0 g as a solid amount of n-butyllithium, and the reaction was carried out for 4 hours.
After cooling, the white dispersion obtained by passing through a 200-mesh nylon cloth was a latex having an average particle size of 0.35 μm.

Production Example 24 of Latex Particles: (Comparative Example A) Latex particles except that a mixed solution of 20 g of poly (octadecyl methacrylate) <dispersion stabilizing resin [R] -1>, 100 g of vinyl acetate, 1 g of octadecyl methacrylate and 380 g of Isopar H is used. Was treated in the same manner as in Production Example 1 to obtain a white dispersion of latex particles having a polymerization rate of 88% and an average particle size of 0.27 μm.

Production Example 25 of Latex Particles: (Comparative Example B) A mixed solution of 97 g of octadecyl methacrylate, 3 g of acrylic acid and 200 g of toluene was heated to a temperature of 75 ° C under a nitrogen stream. 1.0 g of AIBN was added and reacted for 8 hours. Next, 12 g of glycidyl methacrylate, t-butyl hydroquinone
1.0 g, 1.2 g of N, N-dimethyldodecylamine were added, and the temperature was 100.
The mixture was stirred at 0 ° C for 4 hours. After cooling, the precipitate was reprecipitated in 2 l of methanol, and the white powder was collected by filtration and dried. A dispersion stabilizing resin [R] -2 having the following structure was obtained. The yield was 84g and w35,000.

Dispersion stabilizing resin [R] -2: 10 g of this dispersion stabilizing resin [R] -2, vinyl acetate 100
g, octadecyl methacrylate 1.0 g and Isopar H38
Production Example 1 of latex particles except that 4 g of a mixed solution is used
In the same manner as in the above, a white dispersion as latex particles having a polymerization rate of 89% and an average particle size of 0.15 μm was obtained.

Production Example 26 of Latex Particles: (Comparative Example C) 12 g of a dispersion stabilizing resin [R] -3 having the following structure produced by the method described in JP-A-61-63855 and vinyl acetate 1
00g, octadecyl methacrylate 1.0g, Isopar H38
Production example 1 of latex particles except using 2 g of mixed solution
The same treatment as in (1) was performed to obtain a white dispersion which was latex particles having a polymerization rate of 87% and an average particle size of 0.23 μm.

Dispersion stabilizing resin [R] -3: Example 1 10 g of dodecyl methacrylate / acrylic acid copolymer (copolymerization ratio (95/5) weight ratio), 10 g of nigrosine and 30 g of Isopar G were put together with glass beads in a paint shaker (Tokyo Seiki Co., Ltd.), and 4 After time-dispersion, a fine dispersion of nigrosine was obtained.

30 g of the resin dispersion prepared in Production Example 1 of latex particles, 2.5 g of the above nigrosine dispersion, and 0.07 g of octadecene / semi-maleic acid octadecylamide copolymer were added to Isopar G-1.
To obtain a liquid developer for electrostatography.

(Comparative Liquid Developers A to C) In the above production example, the resin dispersion was added to the following resin particles to prepare three types of liquid developers A, B and C for comparison.

Comparative Liquid Developer A: Latex Particle Production Example 24 Resin Dispersion Comparative Liquid Developer B: Latex Particle Production Example 25 Resin Dispersion Comparative Liquid Developer C: Latex Particle Production Example 26 Resin Dispersion Materials These liquid developers are used as a developer for the fully automatic plate making machine ELP404V (manufactured by Fuji Photo Film Co., Ltd.), and the ELP Master II type electrophotographic photosensitive material (manufactured by Fuji Photo Film Co., Ltd.) is exposed and developed. Processed. The plate making speed was 7 plates / minute. In addition, the ELP Master II type is 2000
After the sheet processing, it was observed whether or not the toner adhered to the developing device. The blackening rate (image area) of the copied image was determined using a document having a 40% density. The results are shown in Table-5.

As described above, a plate made using each developer under the plate making conditions,
As is clear from the results in Table 5, the developer of the present invention was the only developer that did not stain the developing device and had a clear image on the 2000th plate.

On the other hand, a master plate for offset printing (ELP master) obtained by making a plate from each developer was printed by a conventional method, and the number of printed sheets until the occurrence of missing characters, blurred solid portions, etc. in the printed image was compared. However, the master plate obtained using the developer of the present invention, Comparative Example A, Comparative Example B and Comparative Example C did not occur even with 10,000 sheets or more.

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 the number of printed master plates was good.

That is, in Comparative Examples A, B and C, there was no problem in the number of printed sheets, but the developing device was contaminated and could not withstand continuous use.

Contamination of the developing device in Comparative Examples B and C is
However, when the developing conditions are severe, the performance has not yet reached a satisfactory level. That is, the known dispersion stabilizing resins of Comparative Examples B and C are:
A chemical structure in which a component containing a polymerizable double bond group that is copolymerized with the monomer (A) [vinyl acetate in this example] contained in the polymer is randomly copolymerized in the polymer is shown. Therefore, it is considered that the redispersibility of the latex particles is inferior to that of the dispersion stabilizing resin of the present invention.

Example 2 100 g of the white dispersion obtained in Production Example 2 of latex particles
And a mixture of Sumicaron Black (1.5 g) was heated to a temperature of 100 ° C., and heated and stirred for 4 hours. By cooling to room temperature and passing through a 200 mesh nylon cloth to remove the remaining dye,
A black resin dispersion having an average particle size of 0.20 μm was obtained.

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

When this was developed by the same apparatus as in Example 1, 2000
After the development of one sheet, the toner adhered to the device did not stain at all.

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 3 100 g of white dispersion obtained in Production Example 21 of latex particles
And a mixture with 3 g of Victoria Blue B at a temperature of 70 ° C ~
The mixture was heated to 80 ° C and stirred for 6 hours. After cooling to room temperature, a 200-mesh nylon cloth was passed through to remove the residual dye, thereby obtaining a blue resin dispersion having an average particle size of 0.16 μm.

32 g of the above blue resin dispersion, zirconium naphthenate 0.0
A liquid developer was prepared by diluting 5 g to 1 of Isopar H.

When this was developed by the same apparatus as in Example 1, 2000
After the development of one sheet, the toner adhered to the device did not stain at all. 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 dispersion 32 obtained in Production Example 12 of latex particles
A liquid developer was prepared by diluting 2.5 g of the nigrosine dispersion obtained in Example 1 and 0.02 g of a half-docosanilamide compound of a copolymer of diisobutylene and maleic anhydride to 1 of Isopar G.

When this was developed by the same apparatus as in Example 1, 2000
No toner adhesion stains on the apparatus were observed even after the sheet development. 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 also clear.

After the developer was allowed to stand for 3 months, the same treatment as above was carried out, but there was no difference from that before the passage of time.

Example 5 10 g of poly (decyl methacrylate), 30 g of Isopar H
Then, 8 g of alkali blue and glass beads were put into a paint shaker together with glass beads, and dispersed for 2 hours to obtain a fine dispersion of alkali blue.

White resin dispersion obtained in Production Example 1 of latex particles
30 g, the above-mentioned alkali blue dispersion 4.2 g, higher alcohol FOC-1400 (manufactured by Kao Corporation) 15 g, and a half-docosanyl amidation product of a copolymer of diisobutylene and maleic anhydride.
A liquid developer was prepared by diluting 06g to 1 of Isopar G.

When this was developed by the same apparatus as in Example 1, 2000
No toner adhesion stains on the apparatus were observed even after the sheet development. 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 very clear.

Examples 6 to 21 Example 5 except that the white resin dispersion of Production Example 1 for latex particles in Example 5 was replaced with the latex particles having a solid content of 6.0 g shown in Table-6. A liquid developer was prepared in the same manner as above.

This was developed by the same apparatus as in Example 1, and even after the development of 2,000 sheets, 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 printing 10,000 sheets 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 extremely high plate-making speed, the developing device did not become stained, and 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 very clear. Was.

Claims (1)

[Claims] 1. A liquid developer for electrostatic photography comprising at least a resin dispersed in a non-aqueous solvent having an electric resistance of 10 ⁹ Ωcm or more and a dielectric constant of 3.5 or less, wherein the dispersed resin particles have the following general formula: A dispersibility in which a polymerizable double bond group copolymerizable with the monofunctional monomer (A) is bonded to only one end of the main chain of the polymer having at least one repeating unit represented by I). In the presence of a stabilizing resin, a monofunctional monomer (A) that is soluble in the non-aqueous solvent but is insolubilized by polymerization, and the following general formula (II)
A monomer (B) containing an aliphatic group having 8 or more carbon atoms and copolymerizing with the monomer (A) by a polymerization reaction
Is a copolymer resin particle obtained by subjecting a solution containing at least one of the following to a polymerization reaction. General formula (I) In the general formula (I), X is —COO—, —OCO—, —CH ₂ OCO—,
-CH ₂ COO -, - O-, or -SO ₂ - represent. R ¹ represents an aliphatic group having 6 to 32 carbon atoms. a ¹ and a ² may be the same as 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. Through -COO-R ² (R ² represents a hydrocarbon group having 1 to 22 carbon atoms)
Represents General formula (II) In the general formula (II), R ³ represents an aliphatic group having 8 or more carbon atoms. Y is -COO-, -CONH-, (R ⁴ represents an aliphatic group), —OCO—, —CH ₂ COO—, or —O—. b ^1, b ^2, which may be the same or different, each represents a hydrogen atom, an alkyl group, -COOR ⁵ or -CH ₂ -COOR ⁵ (R ⁵ represents an aliphatic group).