JPH087467B2 - 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 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, which are petroleum-based. A polar control agent such as a polymer which is dispersed in a liquid having a high insulating property and a low dielectric constant such as an aliphatic hydrocarbon and further contains a metal soap, lecithin, linseed oil, a higher fatty acid and a polymer containing vinylpyrrolidone. 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 hundreds nm, but in a conventional liquid developer, a soluble dispersion stabilizing resin, a polarity control agent and insoluble latex particles are used. Due to insufficient bonding of the above, the soluble dispersion stabilizing resin and the polarity control agent were in a state of being easily diffused in the solution. For this reason, there is a drawback that the soluble dispersion stabilizing resin is separated from the insoluble latex particles by long-term storage or repeated use, and the particles settle, aggregate, or accumulate, or 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, means for chemically bonding the soluble dispersion stabilizing resin and the insoluble latex particles have been devised and 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. In the method for producing resin particles described above, in order to produce monodisperse particles having a narrow particle 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. 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. Furthermore, the dispersion stabilizer used is
There is a problem in that it must be manufactured through a manufacturing process that is frequent and requires a long time.

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.

(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.

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

The present invention improves the problems of the conventional liquid developers 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, in which at least a resin is dispersed in a non-aqueous solvent of 3.5 or less, the dispersed resin particles have a main chain of a polymer containing a repeating unit represented by the following general formula (I). Carboxyl group, sulfo group,
Although it is soluble in a non-aqueous solvent in the presence of a dispersing resin having a weight average molecular weight of 1 × 10 ⁴ or more formed by bonding at least one polar group selected from a hydroxyl group, an amino group and a phospho group, Containing a monofunctional monomer (A) which is insolubilized by polymerization and an aliphatic group having 8 or more carbon atoms represented by the following general formula (II), and copolymerized with the monomer (A) in a polymerization reaction. Is achieved by a liquid developer for electrostatic photography, which is a copolymer resin obtained by polymerizing a solution containing at least one or more monomers (B) that produce Was found.

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

 Y represents an aliphatic group having 6 to 32 carbon atoms.

a ₁ and a ₂ may be the same or different from each other, and each represents a hydrogen atom, a halogen atom, a cyano group, a hydrocarbon group having 1 to 8 carbon atoms, —COO—Z or a hydrocarbon group having 1 to 8 carbon atoms. Through -COO-Z (Z represents a hydrocarbon group having 1 to 22 carbon atoms).

General formula (II) In formula (II), W represents an aliphatic group having 8 or more carbon atoms.

V is -COO-, -CONH-, (R ₁₁ represents an aliphatic group), -OCO-, -CH ₂ OCO- or-
Represents O-.

b ₁ and b ₂ may be the same or different and each represents a hydrogen atom, an alkyl group, —COOR ₁₂ or —CH ₂ COOR ₁₂ (R ₁₂ 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 Ω · cm or more, preferably a linear or branched aliphatic hydrocarbon, alicyclic hydrocarbon or aromatic hydrocarbon as a carrier liquid having a dielectric constant of 3.5 or less, and these Halogen substitutes can be used. For example, octane, isooctane, decane, isodecane, decalin, nonane, dodecane, isododecane, cyclohexane, cyclooctane, cyclodecane, benzene, toluene, xylene, mesitylene, isoper E, isoper G, isoper H, isoper L (Isoper; a product of Exxon) Name), Shersol 70, Shersol 71 (Shersol; trade name of Shell Oil Company), AMSCO OM
S, Amsco 460 solvent (Amsco; trade name of Spirits), 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)
Is a monomer (A) and a non-aqueous solvent in the presence of a dispersion stabilizing resin having a weight average molecular weight of 1 × 10 ⁴ or more, which is formed by bonding a polar group only to one end of the polymer main chain. It is produced by polymerizing granulation by copolymerizing the monomer (B).

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 for producing the dispersed resin particles may be any solvent that is miscible with the carrier liquid, and is preferably a linear or branched aliphatic hydrocarbon, alicyclic hydrocarbon, or aromatic hydrocarbon. Hydrogen and halogen-substituted products thereof are exemplified. For example, hexane, octane, isooctane, decane, isodecane, decalin, nonane, dodecane, isododecane, Isopar E, Isopar G, Isopar H, Isopar L, Cielsol 70, Shelsol 71, Amsco OMS, Amsco 460 solvent, etc., alone or mixed. To use.

Solvents that can be used in combination with these organic solvents include alcohols (eg, methyl alcohol,
Ethyl alcohol, propyl alcohol, butyl alcohol, fluoroalcohol, etc.), ketones (eg, acetone, methyl ethyl ketone, cyclohexanone, 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.) and the like.

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 at the stage of producing the resin dispersion. As described above, linear or branched aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, halogenated Hydrocarbons and the like.

The dispersion-stabilizing resin of the present invention used for forming a stable resin dispersion of the solvent-insoluble copolymer produced by copolymerizing the monomer in a non-aqueous solvent, is polymerized with the monomer. It is a resin not containing a graft group, and has a carboxy group, a sulfo group, a phospho group, a hydroxyl group and an amino group only at one end of a polymer main chain containing at least one repeating unit represented by the general formula (I). It is a polymer formed by bonding at least one polar group selected.

In the repeating unit represented by the general formula (I), the aliphatic group and 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-.

Y preferably represents an optionally substituted alkyl group, alkenyl group or aralkyl group having 8 to 22 carbon atoms. The substituent may be any substituent other than a polar group bonded to one end of the polymer main chain, for example, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, etc.), -O-Z _{1, -COO-Z 2, -OCO} -Z 2 (Z 1, Z 2 represents an alkyl group having 6 to 22 carbon atoms, e.g., hexyl, octyl, decyl, dodecyl, hexadecyl group, octadecyl Group) and the like. More preferably, Y represents an alkyl group or 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 and a docosanyl group.

a ₁ and a ₂ may be the same or different from each other, and preferably a hydrogen atom, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, etc.), a cyano group, an alkyl group having 1 to 3 carbon atoms, —COO. -Z or -CH ₂ COO-Z (Z is 1 to 22 carbon atoms
Represents an aliphatic group). More preferably, a ₁ ,
a ₂ may be the same or different from each other, and is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms (for example, a methyl group, an ethyl group,
Propyl group), - COO-Z or -CH ₂ COO-Z (Z is more preferably an alkyl group or an alkenyl group having 1 to 18 carbon atoms, e.g., methyl group, ethyl group, propyl group, butyl group, Hexyl group, octyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group, hexadecyl group, octadecyl group, pentenyl group, hexenyl group,
Examples thereof include an octenyl group and a decenyl group, and these alkyl groups and alkenyl groups may have the same substituents as those represented by Y).

Further, the polar group bonded only to one end of the polymer main chain has a chemical structure in which it is directly bonded to one end of the polymer main chain or bonded via an arbitrary linking group.

As the bonding group, a carbon-carbon bond (single bond or double bond), a carbon-hetero atom bond (as a hetero atom, for example, an oxygen atom, a sulfur atom, a nitrogen atom, a silicon atom, etc.), a hetero atom-hetero atom bond It is composed of any combination of atomic groups. For example, [R ₁ and R ₂ 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.)] , CH = CH, -O-, -S-, −COO−, −SO ₂ −, -NHCOO-, -NHCONH-, R ₃ is a hydrogen atom or a hydrocarbon group having the same meaning as Z represented by the general formula (I), etc., and is composed of a single connecting group selected from atomic groups or any combination thereof. And a connecting group.

The polymer component of the resin for dispersion of the present invention corresponds to the homopolymer component 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 the above monomer with another monomer that can be copolymerized. Examples of the other monomer serving as the copolymer component together with the polymer component of general formula (I) include compounds represented by general formula (III) described below.

The repeating unit represented by the general formula (I) is 30% by weight to 100% by weight in the resin polymer for dispersion used in the present invention.
Wt% is suitable, preferably 50-100 wt%
Is.

In the polymer main chain, a carboxyl group, a sulfo group,
Those which do not contain a copolymerization component containing polar groups such as hydroxyl group, amino group and sulfo group are preferred.

The dispersion stabilizing resin of the present invention in which a specific polar group is bonded only to one end of the polymer main chain is a method of reacting various reagents with the end of a living polymer obtained by conventionally known anionic polymerization or cationic polymerization. (Method by ionic polymerization method), method of radical polymerization using polymerization initiator and / or chain transfer agent containing specific polar group in molecule (method by radical polymerization method), or ionic polymerization method as described above or It can be easily produced by a synthetic method such as a method of converting a polymer having a reactive group at a terminal obtained by a radical polymerization method into a specific polar group of the present invention by a polymer reaction.

Specifically, P.Dreyfuss, RPQuirk, Encycl.Polym.Sc
Review articles such as i.Eng, 7 , 551 (1987), Yoshiki Chujo, Yuya Yamashita, "Dyes and Chemicals", 30 , 232 (1985), Akira Ueda, Susumu Nagai, "Science and Industry" 60 , 57 (1986), etc. It can be produced by the method described in the cited document or the like.

The dispersion stabilizing resin of the present invention has a weight average molecular weight of 1 × 10 ⁴ to
1 × 10 ⁵ is preferable, and more preferably 1.5 × 10 ⁴ to 8 × 10 ⁴
Is. When the weight average molecular weight is less than 1 × 10 ⁴ , the average particle size of the resin particles obtained by polymerization granulation becomes large (for example, 0.
(More than 5 μm) and the particle size distribution becomes wider. On the other hand, when it exceeds 1 × 10 ⁵ , the average particle size of the resin particles obtained by polymerization granulation becomes large, and it may be difficult to make the average particle size within the preferable range of 0.2 to 0.4 μm.

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,
It contains a monofunctional monomer (A) that is soluble in the solvent but is insolubilized by polymerization, and an aliphatic group having 8 or more carbon atoms represented by the general formula (II), Body (A)
Can be classified into the monomer (B) which causes copolymerization.

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

General formula (II) Wherein, T is -COO -, - OCO -, - CH 2 OCO -, - CH 2 COO
-, -O-, Or [U represents a hydrogen atom or an optionally substituted aliphatic group having 1 to 18 carbon atoms (eg, methyl group, ethyl group, propyl group, butyl group, 2-chloroethyl group, 2-bromoethyl group, 2-cyanoethyl group). 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, etc.) R 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).

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 (A) include, for example, 1 to 1 carbon atoms.
Unsaturation of vinyl esters or allyl esters of aliphatic carboxylic acids of 6 (acetic acid, propionic acid, butyric acid, monochloroacetic acid, trifluoropropionic acid, etc.), acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, etc. Alkyl esters or amides of carboxylic acid having 1 to 4 carbon atoms which may be substituted (eg, an alkyl group such as methyl group, ethyl group, propyl group, butyl group, 2-chloroethyl group, 2-bromoethyl group, 2-fluoroethyl group) 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, vinyltoluene, α-methyl) Styrene, vinylnaphthalene, chlorostyrene, dichlorostyrene, bromostyrene, vinylbenzenecarboxylic acid, vinylbenzenesulfonic acid, chloromethylstyrene, hydroxymethylstyrene, methoxymethylstyrene, N, N-dimethylaminomethylstyrene, vinylbenzenecarboxamide, Unsaturated carboxylic acid such as vinylbenzenesulfoamide), acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid or maleic acid, cyclic anhydride of itaconic acid, acrylonitrile, methacrylonitrile Heterocyclic compounds containing a polymerizable double bond group (specifically, for example, compounds described in "Polymer Data Handbook-Basic Edition", edited by The Polymer Society of Japan, p175-184, Baifukan (published in 1986), for example, N-vinyl pyridine, N-vinyl imidazole, N-vinyl pyrrolidone, vinyl thiophene, vinyl tetrahydrofuran, vinyl oxazoline, vinyl thiazole, N-vinyl morpholine and the like).

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

Explaining the monomer represented by the general formula (II) used in the present invention, preferably in the general formula (II),
W represents an optionally substituted alkyl group having 10 or more carbon atoms or an alkenyl group having 10 or more carbon atoms in total, and V is -COO.
−, −CONH−, [However, R ₁₁ represents an aliphatic group having 1 to 32 carbon atoms (the aliphatic group represents, for example, an alkyl group, an alkenyl group, an aralkyl group, or the like)], —OCO—, —CH ₂ OCO—, or —O −
And b ₁ and b ₂ may be the same or different and each represents a hydrogen atom, a methyl group, —COOR ₁₂ or —CH ₂ COOR ₁₂ (wherein R ₁₂ is an alkyl group having 1 to 32 carbon atoms, an alkenyl group, Indicates an aralkyl group or a cycloalkyl group).

Still more preferably, in the formula (II), X is -COO-,
-CONH- or And b ₁ and b ₂ may be the same or different and each represents a hydrogen atom or a methyl group, and W represents the same symbol 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 (a halogen atom, a hydroxy group, an amino group, a substituent such as an alkoxy group). Which may be contained or may have a carbon-carbon bond in the main chain through a hetero atom such as an oxygen atom, a sulfur atom or a nitrogen atom, may be present) of acrylic acid, methacrylic acid, crotonic acid, maleic acid or itaconic acid Unsaturated carboxylic acid ester acid such as (for example, decyl group, dodecyl group, tridecyl group, tetradecyl group, hexadecyl group as an aliphatic group,
Octadecyl group, docosanyl group, dodecenyl group, hexadecenyl group, oleyl group, linoleyl group, docosenyl group, etc.), the above-mentioned unsaturated carboxylic acid amides (aliphatic groups represent the same as those shown as esters), Substitute a vinyl ester or allyl ester of a higher fatty acid (as a higher fatty acid, for example, lauric acid, myristic acid, stearic acid, oleic acid, linoleic acid, behenic acid), or an aliphatic group having 10 to 32 total carbon atoms Vinyl ethers (the 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, it is preferable to use the monomer (B) represented by the general formula (II) in an amount of 0.1 to 10% by weight, more preferably 0.2 to 5 with respect to the insoluble monomer (A). % By weight. The molecular weight of the dispersion resin of the present invention is 10 ³ to 10 ⁶ , preferably 10 ⁴ to 10 ⁶ .

Specific examples of these dispersion resins are shown below, but the scope of the present invention is not limited to these.

In order to produce the dispersion resin used in the present invention as described above, generally, the dispersion stabilizing resin and the monomer (A) as described above are used.
And the monomer (B) may be heated and polymerized in a non-aqueous solvent in the presence of a polymerization initiator such as benzoyl peroxide, azobisisobutyronitrile, and butyllithium. Specifically, a 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 a polar solvent such as ketones, ethers and esters is used in combination, or when unreacted monomers (A) and (B) to be polymerized and granulated remain, the solvent or a single amount It is preferable to remove it by heating above the boiling point of the body and distilling off or by distilling under reduced pressure.

Non-aqueous latex particles produced as described above,
It exists as fine particles with a uniform particle size distribution, and at the same time exhibits very stable dispersibility, and in particular, it has good dispersibility even when it is repeatedly used for a long time in the developing device, and it can be re-dispersed even if the developing speed is improved. It is easy and no stain is found on any part of the device.

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 plate size master plate is used.

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

The colorant is not particularly specified, 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 in which a dispersing resin and a dye are chemically bonded as disclosed in JP-A-53-54029.
As described in JP-A-44-22955 and the like, there is a method of producing a dye-containing copolymer by using a monomer containing a dye in advance when producing by a polymerization granulation method.

Various additives may be added to the liquid developer of the present invention as needed for the purpose of enhancing charging characteristics or improving image characteristics. For example, Yuji Harazaki, “Electrophotography”, Vol. 16, Vol. No. 4, p.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 is also used if necessary, and is 0.
About 5 to 100 parts by weight can be added. The charge control agent as described above is preferably 0.001 to 1.0 parts by weight per 1000 parts by weight of the carrier liquid. 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 Ωcm.
If it becomes lower, it becomes difficult to obtain a good continuous tone image. Therefore, it is necessary to control the amount of each additive added within this limit.

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

Production Example 1 of Resin for Stabilizing Dispersion A mixed solution of 100 g of octadecyl methacrylate, 150 g of toluene and 50 g of isopropanol was heated to a temperature of 85 ° C. while stirring under a nitrogen stream. 5.0 g of 2,2'-azobis (cyanovaleric acid) (abbreviation ACV) was added and reacted for 8 hours. After cooling, it was reprecipitated in 2 l of methanol, and the white powder was collected by filtration and dried to give a weight average molecular weight (hereinafter referred to as w) 42,00 with a yield of 85 g.
0 powder was obtained.

Production Example 2 of dispersion stabilizing resin 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, reprecipitation in 2 l of methanol gave 83 g of a colorless and transparent viscous product. w is 27,000
Met.

Production Example 3 of Resin for Stabilization of Dispersion A mixed solution of 100 g of docosanyl methacrylate and 300 g of toluene was heated to 70 ° C. while stirring under a nitrogen stream.
Add 6 g of 4,4-azobis (4-cyanopentanol) to 8
Reacted for hours. After cooling, reprecipitation in 2 l of methanol gave 86 g of white powder. w was 28,000.

Dispersion Stabilization Resin Production Example 4 Dodecyl Methacrylate 70g, Butyl Methacrylate 3
A mixed solution of 0 g, 150 g of toluene and 50 g of isopropanol was heated to 70 ° C. with stirring under a nitrogen stream. ACV
6 g was added and reacted for 8 hours. The w of the copolymer was 23,000.

Production Example 5 of dispersion stabilizing resin Tridecyl methacrylate 98.5 g, thioglycolic acid
A mixed solution of 1.5 g and 200 g of toluene was heated to a temperature of 65 ° C. 2,2'-azobis (isobutyronitrile) (abbreviation A.
After adding 1.0 g of IBN) and stirring for 5 hours, 0.3 g of AIBN was added and further stirring for 4 hours. The polymer obtained had a w of 24,0.
It was 00.

Production Example 6 of dispersion stabilizing resin Octadecyl methacrylate 98.0 g, 2-mercaptoethanesulfonic acid 2.0 g, toluene 200 g and methanol 10
0 g of the mixed solution was heated to 65 ° C. under a nitrogen stream. AI
After 0.8 g of BN was added and reacted for 5 hours, 0.3 g of AIBN was further added and reacted for 2.5 hours. The reaction solution was reprecipitated in 2 l of acetonitrile to obtain 88 g of white powder. w was 25,000.

Production Example 7 of Resin for Stabilizing Dispersion A mixed solution of 90 g of hexadecyl methacrylate, 8 g of 2-chloroethyl methacrylate, 2.0 g of thiomalic acid, 150 g of toluene and 50 g of isopropanol was heated to a temperature of 75 ° C. 1.0g of 1,1'-azobis (cyclohexane-1-carbonitrile) was added and reacted for 6 hours.
Was added and reacted for 6 hours. After cooling, reprecipitation in 2 l of methanol gave 86 g of a colorless and transparent viscous product. It was w23,000.

Production Example 8 of Dispersion Stabilizing Resin A mixed solution of 100 g of tetradecyl methacrylate, 100 g of tetrahydrofuran and 100 g of methanol was heated to 70 ° C. while stirring under a nitrogen stream. 2,2'-azobis {2-
Methyl-N- [1,1-bis (hydroxymethyl) -2-
Hydroxyethyl] propioamide} 5g was added and reacted for 8 hours. After cooling, reprecipitation was performed in 2 l of a mixed solution of methanol / water (7/3 volume ratio) to obtain 80 g of a colorless viscous substance. w is 28,00
It was 0.

Production Example 9 of Dispersion Stabilizing Resin A mixed solution of 95 g of dodecyl methacrylate and 200 g of toluene was heated to 70 ° C. under a nitrogen stream. 5 g of 4,4-azobis (4-cyanopentanol) was added and reacted for 8 hours.
Next, 1.0 g of N, N-dimethylaniline and 10 g of glutaconic anhydride were added to this reaction solution, and the mixture was stirred at a temperature of 90 ° C. for 12 hours. After cooling, reprecipitation in 2 l of methanol gave a pale yellow viscous product 88
got g. w was 28,000.

Production Examples 10 to 17 of Dispersion Stabilizing Resin In place of octadecyl methacrylate and ACV which was the initiator in Production Example 1, each of the compounds shown in Table A below was produced to be a dispersion stabilizing resin.

The repeating units of the terminal portion and the main chain containing the polar group of the resins obtained in Production Examples 1 to 17 of the above dispersion stabilizing resins are shown below.

Dispersion stabilizing resin production example 1: Production Example 1 of Latex Particles A mixed solution of 20 g of the resin obtained in Production Example 1 of dispersion stabilizing resin, 100 g of vinyl acetate, 1.0 g of octadecyl methacrylate and 380 g of Isopar H was stirred at a temperature of 75 ° C. under a nitrogen stream.
Warmed to. AIBN 0.8g 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. The temperature was raised to 100 ° C., and the mixture was stirred for 2 hours to remove unreacted vinyl acetate. After cooling, it was passed through a nylon cloth of 200 mesh, and the white dispersion obtained had a polymerization rate of 90% and an average particle size of 0.
It was a 24 μm latex.

Production Example 2 of Latex Particles A mixed solution of 20 g of the resin obtained in Production Example 2 of dispersion stabilizing resin, 100 g of vinyl acetate, 1.5 g of octadecyl methacrylate and 380 g of Isopar H was stirred at a temperature of 70 ° C. under a nitrogen stream.
Warmed to. 0.9 g of benzoyl peroxide was added and reacted for 6 hours. 40 minutes after the addition of the initiator, the homogeneous solution became cloudy and the reaction temperature rose to 85 ° C. After cooling, the white dispersion obtained by passing through a 200-mesh nylon cloth was a latex having a polymerization rate of 88% and an average particle size of 0.26 μm.

Production Example 3 of Latex Particles 12 g of the resin obtained in Production Example 1 of dispersion stabilizing resin, 8 g of poly [octadecyl methacrylate], 100 g of vinyl acetate, 1.8 g of dodecyl methacrylate, and 450 g of Isopar H were stirred at a temperature of 75 with a nitrogen stream. Warmed to ° C. AI
0.7 g of BN was added and reacted for 4 hours, and 0.5 g of AIBN was further added and reacted for 2 hours. After cooling, the mixture was passed through a nylon cloth of 200 mesh, and the obtained white dispersion was latex having an average particle size of 0.25 μm.

Production Example 4 of Latex Particles A mixed solution of 25 g of the resin obtained in Production Example 3 of dispersion stabilizing resin, 100 g of vinyl acetate, 1.2 g of hexadecyl methacrylate and 380 g of isodecane was heated to 75 ° C. while stirring under a nitrogen stream. Add AIBN 1.0g and react for 4 hours.
IBN 0.5g was added and reacted for 2 hours. After cooling, pass through a 200-mesh nylon cloth, and the resulting white dispersion has an average particle size.
The latex was 0.25 μm.

Production Example 5 of Latex Particles 18 g of resin (as solid content) obtained in Production Example 10 of resin for dispersion stabilization, 100 g of vinyl acetate, tridecyl methacrylate
A mixed solution of 1.5 g and 380 g of n-decane was heated to a temperature of 75 ° C. with stirring under a nitrogen stream. AIBN 1.0 g was added and reacted for 4 hours, and AIBN 0.5 g was further added and reacted for 2 hours.
The temperature was raised to 110 ° C. and the mixture was stirred for 2 hours, and the low boiling point solvent and residual vinyl acetate were distilled off. After cooling, it was passed through a nylon cloth of 200 mesh, and the obtained white dispersion was a latex having an average particle size of 0.28 μm.

Production Example 6 of Latex Particles 20 g of the resin obtained in Production Example 5 of dispersion stabilizing resin (as solid content), 100 g of vinyl acetate, 1.5 g of tetradecyl methacrylate and 380 g of shell sol 71 were stirred under a nitrogen gas stream while stirring. Warmed to 75 ° C. Benzoyl peroxide 1.
5 g was added and reacted for 6 hours. Ten minutes after the addition of the initiator, white turbidity occurred and the reaction temperature was raised to 90 ° C. The temperature was raised to 100 ° C. and the mixture was stirred for 1 hour as it was, and the residual vinyl acetate was distilled off. After cooling, it was passed through a nylon cloth of 200 mesh, and the obtained white dispersion was a latex having a weight ratio of 90% and an average particle shape of 0.25 μm.

Production Example 7 of Latex Particles A mixed solution of 18 g of the resin obtained in Production Example 7 of dispersion stabilizing resin and 200 g of shell sol 71 was stirred under a nitrogen stream at a temperature of 70.
Warmed to ° C. A mixed solution of 100 g of vinyl acetate, 1.2 g of octadecyl methacrylate, 180 g of Cielsol 71 and 1.0 g of 2,2'-azobis (isovaleronitrile) (abbreviation AIVN) was added dropwise over 2 hours, and the mixture was stirred for 4 hours as it was.
After cooling, it was passed through a nylon cloth of 200 mesh, and the obtained white dispersion was a latex with a weight ratio of 85% and an average particle size of 0.18 μm.

Production Example 8 of Latex Particles A mixed solution of 20 g of the resin obtained in Production Example 1 of dispersion stabilizing resin, 85 g of vinyl acetate, 15 g of N-vinylpyrrolidone, 0.8 g of docosanyl methacrylate and 400 g of isododecane was stirred under a nitrogen gas stream while stirring. Warmed to 65 ° C. AIBN 1.5g was added and reacted for 4 hours. After cooling, the mixture was passed through a nylon cloth of 200 mesh, and the obtained white dispersion was latex having an average particle size of 0.25 μm.

Production Example 9 of Latex Particles 20 g of the resin obtained in Production Example 1 of resin for dispersion stabilization, 100 g of vinyl acetate, 5 g of 4-pentenoic acid, 2.0 g of octadecyl methacrylate and Isopar G were stirred at a temperature of 60 ° C. under a nitrogen stream. Warmed to. AIVN 1.0g was added and reacted for 2 hours. Further, 0.5 g of AIVN was added and reacted for 2 hours. After cooling, the white dispersion obtained through a 200-mesh nylon cloth was a latex having an average particle size of 0.27 μm.

Production Example 10 of Latex Particles 25 g of resin obtained in Production Example 2 of dispersion stabilizing resin, 100 g of isopropyl methacrylate, 2 g of octadecyl acrylate
The mixed solution of Isopar H and Isopar H was heated to a temperature of 70 ° C. with stirring under a stream of nitrogen. AIVN1.2g was added and reacted for 4 hours. After cooling, coarse particles were removed through a 200-mesh nylon cloth, and the obtained white dispersion was a latex having an average particle size of 0.44 μm.

Production Example 11 of latex particles 25 g of resin obtained in Production Example 1 of dispersion stabilizing resin, styrene 1
A mixed solution of 00 g, vinyl laurate 2.5 g and Isopar H380 g was heated to a temperature of 50 ° C. while stirring under a nitrogen stream. n
A butyllithium-hexane solution was added in an amount of 1.0 g as a solid content and reacted for 4 hours. After cooling, the white dispersion obtained through a 200-mesh nylon cloth had an average particle size of 0.35μ.
m latex.

Latex Particle Production Examples 12 to 17 Latex Particle Production Example 1 was repeated in the same manner as in Production Example 1 except that the polymer of Production Example 1 was replaced with the resin of Table B as the dispersion stabilizing resin. Particles were produced.

Production Example 18 of Latex Particles (Comparative Example A) Polymerization rate was 88 in the same manner as in Production Example 1 of latex particles except that a mixed solution of 20 g of poly [octadecyl methacrylate], 100 g of vinyl acetate and 380 g of Isopar H was used.
%, A white dispersion of latex particles with an average particle size of 0.23 μm was obtained.

Production Example 19 of Latex Particles (Comparative Example B) [Octadecyl methacrylate / acrylic acid (copolymerization ratio (95/5) weight ratio]] A mixed solution of 20 g of copolymer, 100 g of vinyl acetate and 380 g of Isopar H was used below. The same treatment as in Production Example 1 was carried out to obtain a white dispersion which was latex particles having a polymerization rate of 90% and an average particle size of 0.25 μm.

Production Example 20 of Latex Particles (Comparative Example C) Polymerization rate was the same as in Production Example 1 of latex particles except that a mixed solution of 20 g of poly [octadecyl methacrylate], 100 g of vinyl acetate, 1.0 g of octadecyl methacrylate and 380 g of Isopar H was used. 89%, average particle size 0.24
A white dispersion of latex particles of μm was obtained.

Example 1 [Dodecylmethacrylate-acrylic acid (copolymerization ratio (95/5) weight ratio)] Copolymer 10 g, nigrosine 10 g, and Sielsol 71 30 g were put together with glass beads in a paint shaker (Tokyo Seiki Co., Ltd.). The mixture was put in and dispersed for 4 hours to obtain a fine dispersion of nigrosine.

30 g of the resin dispersion of Production Example 1 of latex particles, 2.5 g of the above nigrosine dispersion, and 0.08 g of [octadecene-half-maleic acid octadecylamide copolymer] were added to 1 of Sielsol 71.
To obtain a liquid developer for electrostatography.

(Comparative Developers A to C) Three types of liquid developers A to C for comparison were prepared by replacing the resin dispersion with the following dispersion of resin particles in the above Production Example.

Comparative liquid developer A: Resin dispersion of production example 18 of latex particles Comparative liquid developer B: Resin dispersion of production example 19 of latex particles Comparative liquid developer C: Resin dispersion of production example 20 of latex particles These liquid developers are used as developers for the fully automatic plate-making machine ELP404V (manufactured by Fuji Photo Film Co., Ltd.) to expose and develop an electrophotographic photosensitive material, ELP Master II type (manufactured by Fuji Photo Film Co., Ltd.). Processed. The plate making speed was 5 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 ratio (image area) of the copied image was 20%. The results are shown in Table 1.

As described above, a plate made using each developer under the plate making conditions,
As is clear from the results shown in Table 1, the developer of the present invention was the only developer which did not stain the developing device and had a clear image on the 2000th plate.

On the other hand, the master plate for offset printing (ELP-master) obtained by plate-making from each developer is printed by a conventional method, and the number of printed sheets until the occurrence of missing characters and blurring of solid parts in the image of printed matter is compared. The present invention, Comparative Example A
And the master plate obtained using the developer of Comparative Example B did not occur even after 10,000 sheets, but in Comparative Example C, 8
It occurred in 000 sheets.

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

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

In particular, the dispersion stabilizing resin used in Comparative Example B uses acrylic acid as a copolymerization component and contains a carboxy group in the middle of the polymer main chain, which is the polymer main chain according to the present invention. The redispersion was significantly inferior to the polymer containing a carboxy group only at one end. Further, Comparative Example C was improved over Comparative Examples A and B, but was still insufficient.

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

Example 2 100 g of white background 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. After cooling to room temperature, a 200-mesh nylon cloth was passed through to remove residual dye, whereby a black resin dispersion having an average particle diameter 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 71-1.

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 9 of latex particles
And a mixture of Victoria Blue B3g at a temperature of 70 ° -80 ° C.
The mixture was heated to 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 in Isopar H1.

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 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 2 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 amide of a copolymer of diisobutylene and maleic anhydride into Isopar G1.

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 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
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 3 of latex particles
A liquid developer was prepared by diluting 30 g, the above-mentioned alkali blue dispersion 4.2 g, and 0.06 g of a half-docosanilamide compound of a copolymer of diisobutylene and maleic anhydride to Isopar G1.

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 14 The same as Example 5 except that the amount of the latex particles shown in Table 2 was 6.0 g as the solid content instead of the white resin dispersion of Production Example 3 of the latex particles. A liquid developer was prepared in the same manner.

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.

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 ( Weight average obtained by bonding at least one polar group selected from a carboxyl group, a sulfo group, a hydroxyl group, an amino group and a phospho group to only one end of the main chain of the polymer containing the repeating unit represented by I). Molecular weight is 1 × 10
^In the presence of a dispersing resin of ⁴ or more, a monofunctional monomer (A) soluble in a non-aqueous solvent but insolubilized by polymerization and a carbon number represented by the following general formula (II) Copolymer obtained by polymerizing a solution containing 8 or more aliphatic groups and each containing at least one monomer (B) that undergoes copolymerization with the monomer (A) during the polymerization reaction. A liquid developer for electrostatic photography, which is a united resin. General formula (I) In the formula (I), X is -COO -, - OCO -, - CH 2 OCO -, - CH
₂ COO -, - O- or -SO ₂ - represent. Y represents an aliphatic group having 6 to 32 carbon atoms. a ₁ and a ₂ may be the same or different from each other, and each represents a hydrogen atom, a halogen atom, a cyano group, a hydrocarbon group having 1 to 8 carbon atoms, —COO—Z or a hydrocarbon group having 1 to 8 carbon atoms. Through -COO-Z (Z represents a hydrocarbon group having 1 to 22 carbon atoms). General formula (II) In formula (II), W represents an aliphatic group having 8 or more carbon atoms. V is -COO-, -CONH-, (R ₁₁ represents an aliphatic group), -OCO-, -CH ₂ OCO- or-
Represents O-. b ₁ and b ₂ may be the same or different and each represents a hydrogen atom, an alkyl group, —COOR ₁₂ or —CH ₂ COOR ₁₂ (R ₁₂ represents an aliphatic group).