JPH087465B2 - Liquid developer for electrostatic photography - Google Patents

Description

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 containing metal soap, lecithin, linseed oil, higher fatty acid, or vinylpyrrolidone dispersed in a liquid having a high insulating property and a low dielectric constant such as an aliphatic hydrocarbon is added. In such a developer, the resin is dispersed in the form of particles having a diameter of several nm to several hundreds nm as insoluble latex particles, but in the conventional liquid developer, a soluble dispersion stabilizing resin and 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 easily diffused in the solution. Therefore, there is a drawback that the soluble dispersion stabilizing resin is desorbed from the insoluble latex particles due to long-term storage and repeated use, and the particles are precipitated, aggregated or deposited, or the polarity becomes unclear. Further, the particles that have temporarily aggregated and accumulated are difficult to re-disperse, so that the particles remain attached to various parts of the developing machine, which leads to the failure of the developing machine such as dirt on the image area and clogging of the liquid feed pump. Means for chemically bonding the insoluble latex particles to the soluble dispersion stabilizing resin have been devised in order to improve these drawbacks and are disclosed in US Pat. No. 3,990,980. However, although these liquid developers have improved the dispersion stability against the spontaneous sedimentation of particles to some extent, they are still insufficient, and when used in an actual developing device, the toner adhered to each part of the device is in the form of a coating film. However, it has a drawback that it is hard to re-disperse, and that it is not sufficient for practical re-dispersion stability such as failure of the apparatus and stain of copied images. Further, in the method for producing resin particles described above, in order to produce monodisperse particles having a narrow particle distribution, there are significant restrictions on the combination of the dispersion stabilizer used and the insolubilizing monomer, and generally, It was a particle having a large particle size distribution containing a large amount of coarse particles or a polydisperse particle 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 that the manufacturing process has to be performed through a complicated and time-consuming manufacturing process.

Furthermore, in order to improve the above-mentioned drawbacks, the insolubility of the monomer, and the dispersity of the particles by re-dispersibility of the insoluble dispersed resin particles of a copolymer of a monomer containing a long-chain alkyl portion, A method for improving storage stability is disclosed in JP-A-60-179751.
No. 62-151868 and the like.

On the other hand, in recent years, a method of printing a large number of 5000 or more sheets by using a master plate for offset printing by an electrophotographic method has been attempted. Particularly, improvement of the master plate has been advanced, and 10,000 or more sheets are printed in a large plate size. It has become possible. In addition, the operation time of the electrophotographic plate making system has been shortened, and the development-fixing process has been speeded up.

The dispersed resin particles produced according to the means disclosed in JP-A-60-179751 and JP-A-62-1151868, when the developing speed is increased, in terms of dispersibility and redispersibility of the particles, fixing When the time was shortened or in the case of a master plate of a large plate size (for example, A-3 size or more), the performance was not always satisfactory in terms of printing durability.

"Problems to be Solved by the Invention" The present invention improves the above-mentioned problems of conventional liquid developers.

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 which can be used in any system in which the liquid developer can be used such as ink jet recording, cathode ray tube recording and recording of various changing steps such as pressure change or electrostatic change. That is.

"Means for Solving 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, And a polymer resin particle obtained by polymerizing a solution containing a monofunctional monomer (A) which is insolubilized by polymerization. Was done.

General formula (I) Wherein, 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, 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. -Z-COO-Z (Z represents a hydrocarbon group having 1 to 18 carbon atoms).

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

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 (eg, fluorine atom, chlorine atom, bromine atom, etc.),
_{-0-Z 1, -COO-Z} 2, -OCO-Z 2 (Z 2 is a carbon number 6 to 22
Which is a hexyl group, an octyl group, a decyl group, a dodecyl group, a hexadecyl group, an octadecyl group, etc.) and the like. More preferably, Y represents an alkyl group or alkenyl group having 8 to 22 carbon atoms. For example, octyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group, hexadecyl group,
Examples thereof include octadecyl group and 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 an alkyl group or an alkenyl group having 1 to 12 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, docosanyl group and the like, these alkyl groups,
The alkenyl group may have the same substituent as the above Y).

As the carrier liquid having an electric resistance of 10 ⁹ Ω · cm or more and a dielectric constant of 3.5 or less used in the present invention, linear or branched aliphatic hydrocarbons and halogen-substituted products thereof can be preferably used. For example, octane, isooctane, decane, isodecane, decalin, nonane, dodecane, isododecane, Isopar E, Isopar G, Isopar H, Isopar L (Isopar; trade name of Exxon Corporation), Cielsol
70, Cielsol 71 (Cielsol; trade name of Ciel Oil Co.), Amsco OMS, Amsco 460 solvent (Amsco;
(Trade name of Spirits Inc.) and the like 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) polymerized in a non-aqueous solvent in the presence of a dispersion stabilizing resin having a weight average molecular weight of 1 × 10 ⁴ or more in which a polar group is bonded to only one end of the polymer main chain. It is produced by polymerizing and granulating.

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, 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, fluoroalcohol, etc.), ketones (eg, acetone, methyl ethyl ketone, cyclohexanone, etc.), carboxylic acid esters (eg, methyl acetate, ethyl acetate, etc.)
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 heat or distill off under reduced pressure, but as a latex particle dispersion, even if carried into a liquid developer, if the liquid resistance of the developer is within a range of 10 ⁹ Ωcm or more, there is a problem. I won't.

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 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 monomers represented by the general formula (II).

General formula (II) Wherein, T is _{-COO-, OCO -, - CH 2} OCO -, - CH 2 COO
-, -O-, Or [W 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, 2-hydroxyethyl group, benzyl group, chlorobenzyl group, methylbenzyl group, methoxybenzyl group, phenethyl group, 3-phenylpropyl group, dimethylbenzyl group, fluorobenzyl group,
Represents a 2-methoxyethyl group, a 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).

b ₁ and b ₂ may be the same or different, each represent the same contents 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.), acrylics, methacrylics, 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 acids such as vinylbenzenesulfoamide, acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid or maleic acid, cyclic anhydrides of itaconic acid, acrylonitrile, methacrylonitrile, Heterocyclic compounds containing compatible double bond groups (specifically, for example, compounds described in "Polymer Data Humber Book-Basic Edition", edited by The Society of Polymer Science, p175-184, Baifukan (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.

The dispersion-stabilizing resin of the present invention used for forming a solvent-insoluble polymer produced by polymerizing a monomer in a non-aqueous solvent into a safe resin dispersion is obtained by polymerizing with a monomer (A). Which does not contain a graft group, and has a carboxy group, a sulfo group, a phospho group, a hydroxyl group, 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 from Here, the polar group has a chemical structure in which the polar group is directly bonded to one end of the polymer main chain or is 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 'and R "represent hydrogen atom, halogen atom, fluorine atom, chlorine atom, bromine atom, etc., cyano group, hydroxyl group, etc.] CH = CH, -O-, -S-, −COO−, −SO ₂ −, -NHCOO-, -NHCONH-, [R represents a hydrogen atom, a hydrocarbon group having the same meaning as Z represented by the general formula (I), or the like] or a single linking group selected from atomic groups or any combination thereof. Examples thereof include a linking 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 that serves as a copolymer component together with the polymer component of general formula (I) include compounds represented by general formula (II).

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 containing no copolymerization component containing polar groups such as human loxyl 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
i.Eng, 7 , 551 (1987), Yoshiki Nakajo, Yuya Yamashita "Dyes and Drugs" 30 , 232 (1985), Akira Ueda, Susumu Nagai "Science and Industry", 60 , 57 (1986) In addition, it can be manufactured by the method described in the cited documents.

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.

To produce the latex particles used in the present invention,
Generally, the dispersion stabilizing resin and the monomer (A) as described above are heat-polymerized in a non-aqueous solvent in the presence of a polymerization initiator such as benzoyl peroxide, azobisisobutyronitrile or butyllithium. Good. Specifically, a dispersion stabilizing resin, a method of adding a polymerization initiator to a mixed solution of the monomer (A),
A method in which the monomer (A)) is dropped together with a polymerization initiator into a solution in which the dispersion stabilizing resin is dissolved, or in a solution containing the total amount of the dispersion stabilizing resin and a part of the monomer (A). , A method of optionally adding the remaining monomer together with the polymerization initiator,
Furthermore, there is a method of optionally adding a mixed solution of a dispersion stabilizing resin and a monomer together with a polymerization initiator in a non-aqueous solvent, and any method can be used for production.

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

The amount of the soluble resin serving as the dispersion stabilizing resin is 1 to 100 parts by weight, preferably 5 to 50 parts by weight, based on 100 parts by weight of the total 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 60 to 180 ° C.
~ 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 or esters is used in combination, or when unreacted monomer (A) to be polymerized and granulated remains, it is heated above the boiling point of the solvent or monomer. It is preferable to remove it by distilling it off or distilling it off 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. Examples thereof include magnetic iron oxide powder, powdered lead iodide, carbon black, nigrosine, alkali blue, Hansa yellow, quinacridone red, and phthalocyanine blue.

As another method of coloring, there is a method of dyeing a dispersion resin with a preferable dye as described in JP-A-57-48738. Alternatively, as another method, there is a method of chemically bonding a dispersion resin and a dye, as disclosed in JP-A-53-54029, or the method described in JP-B-44-22955. As described above, there is a method in which a monomer containing a dye in advance is used to prepare a dye-containing copolymer during the production by the 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.

The toner particles containing a resin and a colorant as main components are preferably 0.5 to 50 parts by weight with respect to 1000 parts by weight of the carrier liquid. 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. Furthermore,
The carrier liquid soluble resin for dispersion stabilization is optionally used, and is 0.5 to 100 parts by weight per 1000 parts by weight of the carrier liquid.
About parts by weight can be added. The charge control agent as described above is preferably 0.001 to 1.0 parts by weight with respect to 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, if the electric resistance of the liquid developer with the toner particles removed is lower than 10 ⁹ Ωcm, it becomes difficult to obtain a continuous tone image of good quality, so the amount of each additive added should be within this limit. It is necessary to control.

The embodiments of the present invention will be illustrated below, but the contents of the present invention are not limited thereto.

Production Example 1 of Dispersion Stabilizing Resin A mixed solution of 100 g of octadecyl methacrylate, 150 g of toluene and 50 g of isopropanol was heated to 70 ° C. while stirring under a nitrogen stream. 5.0 g of 2,2'-azobis (4-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) of a yield of 85 g.
000 powders were 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 3 g of a colorless and transparent viscous product. W was 27,000. Production Example 3 of Resin for Stabilization of Dispersion 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. 6g of 4,4'-azobis (4-cyanopentanol) was added and reacted for 8 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.
IBN) (1.0 g) was added and the mixture was stirred for 5 hours, then AIBN 0.3 was added and the mixture was further stirred 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 adding 0.8 g of BN and reacting for 5 hours, 0.3 g of AIBN was further added and reacted for 2.5 hours. This reaction solution was added to acetonitrile 2
Reprecipitation in 1 l gave 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. 1.0 g of 1,1'azobis (cyclohexane-1-carbonitrile) was added and reacted for 6 hours, and 0.4 g of the above initiator was further 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] pyropioamide} 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 a temperature under a nitrogen stream. 4,4'-azobis (4
-Cyanopentanol) 5 g 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 88 g of a pale yellow viscous product. w was 28,000.

The repeating units of the terminal portion and the main chain containing the polar groups of the resins obtained in Production Examples 1 to 9 of the above dispersion stabilizing resins are shown below.

Dispersion stabilizing resin production example 1: Production Example 1 of Latex Particles 20 g obtained in Production Example 1 of dispersion stabilizing resin, vinyl acetate 100
A mixed solution of g and 380 g of Isopar H was heated to a temperature of 75 ° C. with stirring under a nitrogen stream. 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 obtained white dispersion had a polymerization rate of 90.
% Was a latex having an average particle size of 0.24 μm.

Production Example 2 of latex particles 20 g obtained in Production Example 2 of dispersion stabilizing resin, vinyl acetate 100
A mixed solution of g and 380 g of Isopar H was heated to 70 ° C. while stirring under a nitrogen stream. 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, 2000
The white dispersion obtained through a 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 A mixed solution of 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 and 450 g of Isopar H was heated to 75 ° C. with stirring under a nitrogen stream. did. Add AIBN 0.7g and react for 4 hours,
Further, 0.5 g of AIBN was added and reacted for 2 hours. After cooling 20
After passing through a 0-mesh nylon cloth, the obtained white dispersion was a latex having an average particle size of 0.20 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, g of vinyl acetate and 380 g of isodecane was heated to 75 ° C. while 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.
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 0.23 μm.

Production Example 5 of Latex Particles A mixed solution of 18 g of the resin obtained in Production Example 4 of dispersion stabilizing resin (as a solid-formation amount), 100 g of vinyl acetate and 380 g of n-decane was heated to a temperature of 75 ° C. with stirring under a nitrogen stream. did. AI
BN 1.0 g was added and reacted for 4 hours, and AIBN 0.5 g was 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 20
After passing through a 0-mesh nylon cloth, the obtained white dispersion was a latex having an average particle size of 0.28 μm.

Production Example 6 of Latex Particles A mixed solution of 20 g (as solid content) of the resin obtained in Production Example 5 of dispersion stabilizing resin, 100 g of vinyl acetate and 380 g of Shell Sol 71 was heated to 75 ° C. while stirring under a nitrogen stream. .
1.5 g of benzoyl peroxide was added and reacted for 6 hours. Ten minutes after the addition of the initiator, white turbidity occurred and the reaction temperature rose 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 diameter of 0.25 μm.

Production Example 7 of Latex Particles A mixed solution of 18 g of the resin obtained in Production Example 6 of a resin for dispersion stabilization and 200 g of shell sol 71 was stirred at a temperature of 70 under a nitrogen stream.
Warmed to ° C. Vinyl acetate 100g, Cielsol 71 180g and 2,2'-azobis (isovaleronitrile) (abbreviation AI
A mixed solution of 1.0 g of VN) was added dropwise over 2 hours, and the mixture was further stirred for 4 hours. After cooling, it was passed through a 200-mesh nylon cloth, and the resulting white dispersion had a weight percentage of 85% and an average particle size of 0.
The latex was 18 μm.

Production Example 8 of Latex Particles 20 g of resin obtained in Production Example 7 of dispersion stabilizing resin, 85 g of vinyl acetate, 15 g of N-vinylpyrrolidone and 400 g of isodothecan.
The mixed solution of (1) was heated to a temperature of 65 ° C with stirring under a nitrogen stream. AIBN 1.5g was added and reacted for 4 hours. 200 after cooling
The white dispersion obtained through a nylon mesh cloth was a latex having an average particle size of 0.25 μm.

Production Example 9 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, 5 g of 4-pentenoic acid and Isopar G was heated to a temperature of 60 ° C. while stirring under a nitrogen stream. AIV
Add N.1.0g and react for 2 hours, add AIVN 0.5g and add 2
Reacted for hours. After cooling, the white dispersion obtained through a 200-mesh nylon cloth was a latex having an average particle size of 0.28 μm.

Production Example 10 of Latex Particles A mixed solution of 25 g of the resin obtained in Production Example 2 of dispersion stabilizing resin, 100 g of isopropyl methacrylate, and Isopar H was heated to 70 ° C. with stirring under nitrogen. AIVN
1.2 g 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 0.45 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 and 380 g of Isopar H was heated to a temperature of 50 ° C. with stirring under a nitrogen stream. An n-butyllithium hexane solution was added in an amount of 1.0 g as a solid content, and the mixture was 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 0.35 μm.

Production Example 12 of Latex Particles (Comparative Example A) The same procedure 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, the polymerization rate was 88.
%, A white dispersion of terax particles having an average particle size of 0.23 μm was obtained.

Production Example 13 of Latex Particles (Comparative Example B) [Octadecylmethacrylate / 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 is used. Was treated in the same manner as in Production Example 1 to obtain a white dispersion which was latex particles having a polymerization rate of 90% and an average particle size of 0.25 μm.

Example 1 [Dothesyl methacrylate-acrylic acid (copolymerization ratio (95/5) weight ratio)] Copolymer 10 g, nigrosine 10 g, and Sielsol 71 30 g were added together with glass beads to a paint shaker (Tokyo Seiki Co., Ltd.). ) 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 [octadecene-half-maleic acid octadecylamide copolymer] was added to 1% of Sielsol 71.
To obtain a liquid developer for electrostatography.

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

Comparative Liquid Developer A: Resin Dispersion of Latex Particle Production Example 12 Comparative Liquid Developer B: Resin Dispersion of Latex Particle Production Example 13 These liquid developers were fully automatic plate-making machine ELP404V (Fuji Photo Film ( ELP Master II type (manufactured by Fuji Photo Film Co., Ltd.), which is an electrophotographic photosensitive material, was exposed and developed. 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 rate (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 that 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
The master plate obtained by using the developer of Comparative Example B did not occur even after 10,000 sheets.

From the above results, only the developer using the resin particles of the present invention as a developer did not stain the developing device at all and the number of printed master plates was good.

That is, in the case of Comparative Examples A and B, there was no problem in the number of printed sheets, but the developing device was markedly 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 redispersibility was remarkably inferior to the polymer containing a carboxy group only at one end.

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, pass a 200 mesh nylon cloth to remove the residual 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 71-1.

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

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.
And stirred for 6 hours. After cooling to room temperature, pass through a 200-mesh nylon cloth to remove the residual dye, and to obtain an average particle size of 0.
A 16 μm blue resin dispersion was obtained.

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. 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 this 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 in a paint shaker 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 9 As Example 5, except that the latex particles shown in Table 2 were used in an amount of 6.0 g as a solid content instead of the white resin dispersion of Production Example 3 of 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 (I ) A weight average molecular weight 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 a polymer containing a repeating unit represented by Is 1 × 10 ⁴
In the presence of the dispersing resin as described above, a polymer obtained by polymerizing a solution containing a monofunctional monomer (A) that is soluble in a non-aqueous solvent but is insoluble by polymerization. A liquid developer for electrostatic photography, which is composed of coalesced resin particles. General formula (I) Wherein, 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, 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. -Z-COO-Z (Z represents a hydrocarbon group having 1 to 18 carbon atoms).