JPH10254181A - Liquid developer for electrostatic latent image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an image excellent in sharpness and reproducibility without roughening of a printed image by mixing and dispersing a dispersion stabilizer and a quaternary ammonium salt compd. SOLUTION: In a liquid developer prepared by dispersing a resin and a coloring agent in an electric insulating aliphatic hydrocarbon solvent, a dispersion stabilizer and a quaternary ammonium salt compd. are mixed and dispersed. An electric insulating aliphatic hydrocarbon solvent is used as a dispersion medium or a carrier liquid for the resin, coloring agent, dispersion stabilizer and quaternary ammonium salt. The electric insulating aliphatic hydrocarbon solvent is not specified, and usually a solvent having >=10<9> Ω.cm electric resistance, <=3 dielectric const. and 68 to 250 deg.C boiling temp., for example, n-hexane, n-heptane, etc., and be used. As for the resin used for the liquid developer, an ethylene copolymer, acryl copolymer, etc., can be used. Thereby, a stable dispersion liquid in which particles of the liquid toner are dispersed while maintaining a specified particle size can be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid developer for an electrostatic latent image which has excellent dispersion stability of particles, has no roughness in a printed image, and has excellent image clarity and image reproducibility.

[0002]

2. Description of the Related Art A general liquid developer contains a binder, a coloring agent, an additive and the like in an electrically insulating carrier liquid having a high electric resistance and a low dielectric constant, such as an aliphatic hydrocarbon solvent. It is a dispersion of the toner particles, which is usually a natural or synthetic resin as a binder, a pigment or dye as a colorant, a dispersant such as metal soap as an additive, respectively mixed with the carrier liquid, uniformly The mixture is kneaded to prepare a concentrated toner having a nonvolatile content of about 1 to 20 wt%, and then the concentrated toner is diluted and prepared to have a nonvolatile content of about 0.1 to 5 wt%.

The toner particles in the liquid toner need to have a binder and a colorant bonded to each other and to be stably dispersed while maintaining a constant particle size. In order to obtain this stability, there is known an example in which a soluble aluminum chelate is added to a carrier liquid as shown in JP-A-4-100062. However, this is insufficient, and there is a problem that the image is rough.

[0004]

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, the present invention provides a liquid for electrostatic latent images which can provide a printed image with no roughness and excellent sharpness and reproducibility. No developer is provided.

[0005]

The present invention employs the following means in order to solve the above problems. That is, the liquid developer for an electrostatic latent image of the present invention is a liquid developer for an electrostatic latent image obtained by dispersing a resin and a colorant in an electrically insulating aliphatic hydrocarbon-based solvent. A quaternary ammonium salt compound is mixed and dispersed.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention provides a printed image with no roughness.
The liquid developer for electrostatic latent images excellent in image clarity and image reproducibility was studied diligently, and when a dispersion stabilizer and a quaternary ammonium salt compound were added to the developer, the dispersion stability of the particles was improved. Not only significantly improves
It has been sought to solve the above-mentioned problems at once.

In the present invention, an electrically insulating aliphatic hydrocarbon solvent is used as a dispersion medium or a carrier liquid of a resin, a colorant, a dispersion stabilizer and a quaternary ammonium salt compound.

The electrically insulating aliphatic hydrocarbon solvent is not particularly limited, but usually has an electric resistance of 10 or less.
It has a dielectric constant of not more than ⁹ Ω · cm and not more than 3, and has a boiling point of 6
Commercially available, such as n-hexane, n-heptane, n-octane, n-nonane, n-decane, n-undecane, n-dodecane, n-tridecane, isooctane, ligroin and mixtures thereof in the range of 8 to 250 ° C. "ISOPAR" sold by Esso Oil Co., Ltd.
E, G, H, L, M, “Solvesso” 150, “Shellsol” 71 sold by Shell Sekiyu KK,
Organic solvents such as "IP Solvent" 1016, 1620, 2028 sold by Idemitsu Oil Co., Ltd., and NAS-3, NAS-4 sold by NOF Corporation. Particularly, the boiling point is 100 to 20
Solvents at 0 ° C., such as “Isopar” G, H, L, are preferred.

The resin used in the liquid developer of the present invention includes an ethylene copolymer, an acrylic copolymer, an ethylene-vinyl acetate copolymer, an ethylene-acrylate copolymer, and a metal of ethylene and methacrylic acid. Ion-crosslinked polymers, ethylene-vinyl chloride copolymers, ethylene-maleic anhydride copolymers, ethylene-vinyl acetate-acrylate terpolymers, vinyl acetate-acrylic copolymers, vinyl acetate-methacrylic copolymers, etc. Preferably, the resin is at least one resin selected from alkyl acrylate and alkyl methacrylate and one or more resin selected from cycloalkyl acrylate, cycloalkyl methacrylate, aralkyl acrylate and aralkyl methacrylate.
It is composed of a copolymer segment soluble in an aliphatic hydrocarbon-based solvent having at least one kind as a main component and a polymer segment insoluble in the solvent containing vinyl acetate as a main component, and a non-gel state insoluble in the solvent as a whole. Is a copolymer of

[0010] As the soluble copolymer segment, one or more selected from alkyl acrylate and alkyl methacrylate and one selected from cycloalkyl acrylate, cycloalkyl methacrylate, aralkyl acrylate and aralkyl methacrylate are used. A copolymer segment having the above as a main component is preferably used, and among them, at least one selected from alkyl acrylate and alkyl methacrylate and at least one selected from cycloalkyl acrylate and cycloalkyl methacrylate The main component is a copolymer segment. The soluble copolymer segment may be copolymerized with other vinyl compounds such as vinyl versatate. Usually, the copolymerization ratio can be varied depending on the purpose, but if the range generally used is strongly specified, one selected from alkyl acrylate and alkyl methacrylate is 40 to 80% by weight, preferably 45 to 7% by weight.
5 wt%, one selected from cycloalkyl acrylate, cycloalkyl methacrylate, aralkyl acrylate and aralkyl methacrylate is 20 to 60 wt%, preferably 25 to 50 wt%, and the vinyl compound is 0 to 20 wt%, preferably 5 to 20 wt%. A range of ~ 15 wt% is used.

The alkyl group of the alkyl acrylate or alkyl methacrylate used as the soluble copolymer segment is not particularly limited, but is usually an alkyl group having 3 to 20 carbon atoms, preferably 4 to 18 carbon atoms. Those having a group are preferably used. Specific examples include butyl or isobutyl acrylate, methacrylate, t-butyl, 2-ethylhexyl, octyl,
Esters such as isononyl, decyl, lauryl, dodecyl and stearyl are used. The cycloalkyl group of the cycloalkyl acrylate or cycloalkyl methacrylate in the present invention is not particularly limited, but usually has 6 to 8 carbon atoms, and preferably includes a cyclohexyl group. As a specific example, cyclohexyl acrylate or cyclohexyl methacrylate is most preferably used. As aralkyl acrylate or aralkyl methacrylate, benzyl acrylate or benzyl methacrylate is most preferably used.

It is more preferable to use an organic mercaptan as a polymerization modifier during the polymerization of the soluble copolymer segment, since the dispersion stability of the insoluble polymer segment is improved. As the organic mercaptan, higher alkyl mercaptans generally used as polymerization regulators are used, and there is no particular limitation. Usually, higher alkyl mercaptans having an alkyl group having 7 or more carbon atoms, preferably 8 to 20 carbon atoms, are used. Used. Particularly, n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, n-octadecyl mercaptan and the like are preferably used. The polymerization catalyst for the soluble copolymer segment is not particularly limited, but usually an azobisalkylnitrile having 3 to 6 carbon atoms in the alkyl group is used. In particular, azobisisobutyronitrile is preferred.

As the insoluble copolymer segment, a copolymer segment containing vinyl acetate as a main component is preferably used, and alkyl acrylate, alkyl methacrylate, cycloalkyl acrylate, cycloalkyl methacrylate, aralkyl acrylate and It may be a copolymer segment with one or more types such as aralkyl methacrylate. As the polymer segment containing vinyl acetate as a main component, a polymer segment or a copolymer segment having a vinyl acetate component of 50 to 100% by weight, preferably 65 to 100% by weight is preferably used. The alkyl acrylate or alkyl methacrylate here is not particularly limited, but the alkyl group usually has 1 to 20 carbon atoms.
And preferably has an alkyl group of 1 to 18, and specifically, esters such as acrylic acid or methyl methacrylate, ethyl, 2-hydroxyethyl, isobutyl, octyl, stearyl, isononyl and the like are preferably used. The cycloalkyl group of the cycloalkyl acrylate or the cycloalkyl methacrylate herein is not particularly limited, but usually has 6 to 8 carbon atoms.
And preferably a cyclohexyl group. As a specific example, cyclohexyl acrylate or cyclohexyl methacrylate is most preferably used. As aralkyl acrylate or aralkyl methacrylate, benzyl acrylate or benzyl methacrylate is most preferably used.

As the polymerization catalyst used for producing the insoluble polymer segment, diacyl peroxides can be usually used, but benzoyl peroxide, lauroyl peroxide, p-chlorobenzoyl peroxide and the like are preferably used. Can be

As a method for producing a copolymer as a resin used in the liquid developer of the present invention, for example, the above-mentioned aliphatic hydrocarbon solvent can be used as a reaction solvent. A monomer for composing the copolymer segment is added, polymerization is performed to obtain a soluble copolymer segment, and then a monomer for composing the insoluble polymer segment is added as it is, followed by polymerization. It can also be obtained by a step method. The molecular weight of the copolymer varies depending on the type of the monomer used and the combination thereof, but is 5,000 to 50,000 in terms of weight average molecular weight.
0, preferably from 8,000 to 20,000
It is particularly preferred to prepare The ratio of the soluble copolymer segment to the insoluble polymer segment varies depending on the combination of the monomers used, but generally, the soluble copolymer segment is 25 to 60 wt% of the entire copolymer.
%, Especially in the range of 30 to 45% by weight. In this range, the particle size of the insoluble polymer segment is presumed to be small, and the colorant and the soluble copolymer segment are sufficiently bonded. Incidentally, the copolymer is preferably a graft copolymer composed of the soluble copolymer segment and the insoluble polymer segment,
If it is a copolymer having both segments, it is not necessarily limited to this.

The amount of the resin used in the liquid developer of the present invention differs depending on the nonvolatile content because it is an emulsion. For example, when the nonvolatile content is 35% by weight, 20 to 90% by weight, preferably 20 to 90% by weight of the entire nonvolatile component of the developer. Is 25-85wt
%, More preferably 30 to 85% by weight.

The colorant used in the present invention is not particularly limited, and various known colorants used as colorants for this type of toner can be used. Usually, carbon black, organic pigments, inorganic pigments, dyes and the like can be used.

Specific examples of the colorant for black include carbon black, spirit black, aniline black (CIPigment Black 1), and fired metal pigments. As carbon black, any of furnace black, acetylene black, channel black and the like can be used.

Specific examples of the coloring agent for cyan include dianisidine blue (CIPigment Blue 25), phthalocyanine blue (CIPigment Blue 15), peacock blue lake (CIPigment Blue 24), Victoria Pure Blue Lake (CIPigmentBlue 1), and Indantron. Blue (CIPigment Blue 60), Alkaline Blue (C.
I. Pigment Blue 19) can be used.

Specific examples of the coloring agent for magenta include barium red 2B (CIPigment Red 48: 1), calcium red 2B (CIPigment Red 48: 2), strontium red (CIPigment Red 48: 3), and manganese red 2
B (CIPigment Red 48: 4), barium lithol red (CIPigment Red 49: 1), calcium red 52 (C.
I. Pigment Red 52: 1), Lake Red C (CIPigment)
Red 53: 1), Brilliant Carmine 6B (CIPigment
Red 57: 1), Bon Maroon Light (CIPigment Red 5
8: 4), Brilliant Carmine 3B (CIPigment Red 6
0: 1), Brilliant Scarlet G (CIPigment Red
64: 1), Toluidine Red (CIPigment Red 3),
Pyralozone red B (CIPigment Red 38), Phloxine B lake (CIPigment Red 174), Rhodamine 6G
Lake (CIPirgent Red 81), Dianthraquinonyl Red (CIPigment Red 177), Thioindigo Bordeaux (CIPigment Red 88), Perinone Red (CIPigmen)
t Red 194), quinacridone magenta (CIPigment Re
d 122), Quinacridone Maroon (CIPigment Red206
), Quinacridone scarlet (CIPigment Red 207)
), Isoindolinone Red 2BLT (CIPigment R
ed 180), Madder Lake (CIPigment Red83) and the like can be used.

Specific examples of colorants for yellow include Fast Yellow G (CIPigment Yellow 1), Fast Yellow 10G (CIPigment Yellow 3), Disazo Yellow AAA (CIPigment Yellow 12), Disazo Yellow AAMX (CIPigment Yellow 13), Disazo Yellow AAOT (CIPigment Yellow 14), Disazo Yellow AAOA (CIPigment Yellow 17), Tartrazine Yellow Lake (CIPigment Yellow 100),
Condensed azo yellow GR (CIPigment Yellow 95), quinoline yellow lake (CIPigment Yellow 115), thioflavin lake (CIPigment Yellow 18), flavanthrone yellow (CIPigment Yellow 24), isoindolinone yellow 3RLT (CIPigment Yellow 11)
0), Quinophthalone Yellow (CIPigment Yellow 13
8), isoindoline yellow (CIPigment Yellow 13
9), Copper Azomethine Yellow (CIPigment Yellow 11)
7) etc. can be used. Although the amount of the coloring agent varies depending on the color, it is 10 to 10% of the total amount of the non-volatile components of the developer.
It is 50% by weight, preferably 15 to 45% by weight.

The dispersion stabilizer used in the present invention has a molecular weight of 1,500 to 100,000 based on polystyrene.
It is preferable to include a higher aliphatic polyester in the range described above. Such a higher aliphatic polyester, in combination with the specific binder, significantly improves the toner dispersion stability, storage stability, and printing performance. The higher aliphatic polyester can be produced by any method. For example, it can be produced by a polycondensation reaction of a higher fatty acid and an alcohol or by polycondensation of a higher fatty acid having a hydroxy group.

As the higher fatty acid and the higher fatty acid containing a hydroxy group, higher fatty acids having C of 11 or more are used. Specific examples of these include decalic acid, lauric acid, myristic acid, palmitic acid, palmitooleic acid, stearic acid, oleic acid, vaccenic acid, linoleic acid, linolenic acid, eleostearic acid, arachidic acid,
Behenic acid, cerotic acid, montanic acid and the like can be used. One or more of these acids may be substituted, and examples of the substituent include —OH, —CH ₃ , C ₂ H ₅
Which can be used. Particularly, hydroxystearic acid, hydroxypalmitic acid and hydroxyarachidic acid are preferably used. Further, the higher aliphatic polyester has a molecular weight Mw = 1,500-10 based on polystyrene.
Preferably, it is a 000 higher aliphatic polyester. Particularly, 2,000 to 10,000 is preferable. 1,
If it is less than 500, the dispersion stability becomes insufficient, and
If it exceeds 00, the viscosity becomes high and the dispersion becomes insufficient. Examples of such a polyester of hydroxystearic acid include KF-1000 (Kawaken Fine Chemical Co., Ltd.)
), But is not limited thereto.

The dispersion stabilizer preferably contains at least one compound selected from the following formulas 1, 2, and 3.

[0025]

Embedded image

Embedded image

Embedded image The above compound, in combination with the specific resin, significantly improves the dispersion stability, storage stability, and printing performance of the toner. Specific examples include methyl laurate, methyl myristate,
Methyl palmitate, methyl stearate, methyl oleate, methyl linoleate, methyl linolenate, methyl ricinoleate, methyl arachidate, methyl behenate,
Methyl erucate, methyl lignoserate, methyl octacosanoate, ethyl laurate, ethyl dodecanoate, ethyl myristate, ethyl palmitate, ethyl stearate, ethyl oleate, ethyl linoleate, ethyl linoleate, ethyl ricinoleate, ricino Ethyl elaidate, ethyl nonadecanoate, ethyl arachidate, ethyl behenate, ethyl brassic acid, ethyl lignocerate, methyl octacosanoate, butyl undecanoate, vinyl laurate, butyl laurate, octadecyl laurate, lauryl laurate, Isopropyl myristate, butyl myristate, tetradecyl myristate,
Cetyl myristate, vinyl palmitate, isopropyl palmitate, butyl palmitate, octyl palmitate, pentadecyl palmitate, vinyl stearate, isopropyl stearate, butyl stearate,
Octyl stearate, stearyl stearate, triacontil stearate, isopropyl petroselate, propyl 7-octadecenoate, propyl oleate, oleyl oleate, isobutyl elaidate, 10
-Propyl octadecenoate, isopropyl ricinylate, hebenyl behenate, docosyl behenate, tetracosyl lignocerate, myricyl melysinate, monomethyl 1-, 9-nonamethylenedicarboxylate, dimethyl 1-, 9-nonamethylenedicarboxylate, 1-, Monoethyl 9-nonamethylenedicarboxylate, diethyl 1-, 9-nonamethylenedicarboxylate, monomethyl 1-, 10-decamethylenedicarboxylate, 1-, 1
Dimethyl 0-decamethylenedicarboxylate, monoethyl 1-, 10-decamethylenedicarboxylate, diethyl 1-, 10-decamethylenedicarboxylate, monomethyl 1-, 12-dodecamethylenedicarboxylate, 1-, 12-dodecamethylenedicarboxylic acid Dimethyl, monoethyl 1-, 12-dodecamethylenedicarboxylate, 1
Diethyl-, 12-dodecamethylenedicarboxylate, monomethyl 1-, 16-hexadecamethylenedicarboxylate, dimethyl 1-, 16-hexadecamethylenedicarboxylate, monoethyl 1-, 16-hexadecamethylenedicarboxylate, 1-, 16 -Diethyl hexadecamethylene dicarboxylate, dipropyl 1-, 16-hexadecamethylene dicarboxylate, diisopropyl 1-, 16-hexadecamethylene dicarboxylate, dibutyl 1-, 16-hexadecamethylene dicarboxylate, 1-, 16-hexa Diisobutyl decamethylene dicarboxylate, dipentyl 1-, 16-hexadecamethylene dicarboxylate and the like can be used, but not limited thereto. Preferably, the R group is 9 ≦ n
≦ 25, more preferably 9 ≦ n ≦ 20. Of these, monoesters are particularly preferred. The amount of the compound to be added is preferably 0.05 to 15% by weight, more preferably 0.1 to 15% by weight of the entire nonvolatile components of the developer.
wt%, particularly preferably 0.1 to 12 wt%.

The developer of the present invention may further contain a dispersant. As examples of the dispersant, for example, metal salts of naphthenic acid, octylic acid, stearic acid, alkyl phosphoric acid, alkylbenzene sulfonic acid, resin acid, and fatty acid are preferably used. As a metal constituting the metal salt, Li,
Ca, Ba, Zr, Mn, Co, Ni, Cu, Zn, C
The metals of Group II and Group IV of the periodic table, such as d, Al, and Pt, and transition metals are effective. Particularly, a multimer, preferably a trimer of aluminum oxide acylate is also preferably used. Multimers of aluminum oxide acylate are, for example, “Olive” AOS (Hope Pharmaceutical Co., Ltd.)
), "Olive" AOO (manufactured by Hope Pharmaceutical Co., Ltd.), lubricant OA-S (manufactured by Kawaken Fine Chemical Co., Ltd.), and lubricant OA-O (manufactured by Kawaken Fine Chemical Co., Ltd.) are particularly preferably used. . The amount of the dispersant to be added is 0.05 to 15% by weight, preferably 0.1 to 15% by weight, based on the entire nonvolatile components of the developer.
1 to 12% by weight.

In the present invention, it is important to use a quaternary ammonium salt compound. Preferably, the anion of the quaternary ammonium salt compound is an inorganic anion containing a molybdenum or tungsten atom. Specific examples of inorganic anions include molybdic acid, tungstic acid, phosphomolybdic acid, silicomolybdic acid, phosphotungstic acid, silicotungstic acid, phosphotungsten / molybdic acid, silicotungsten / molybdic acid, phosphotungsten / molybdic acid, chromium / Molybdic acid or the like can be used. Specific examples of such a quaternary ammonium salt compound include TP-30 manufactured by Hodogaya Chemical Co., Ltd.
2,415 etc. can be used.

The liquid developer according to the present invention can be produced by various known methods of mixing and dispersing a liquid. For example, a mixture of a dispersion of a copolymer and a colorant, a mixture of a dispersant and the above compound is uniformly kneaded in an aliphatic hydrocarbon-based solvent by a ball mill, a sand mill, an attritor, or the like. It can be prepared by preparing a concentrated toner having a non-volatile content of the order, and diluting the concentrated toner with the aliphatic hydrocarbon solvent so that the non-volatile content becomes about 0.05 to 5 wt%.

The electrostatic latent image liquid developer of the present invention can develop an electrostatic latent image obtained by an electrophotographic system or an electrostatic recording system, and is effectively used as such a developer. In particular, it is effective as a developer for the ion flow recording method of forming an ion pattern on a recording medium using an ion printer that forms an ion image by an ion flow, and developing according to the ion pattern formed image to obtain information recording and an image recording medium. Used for

[0030]

Examples of the present invention will be described below. Hereinafter, the number of parts means parts by weight.

Reference Example 1 Aliphatic solvent "Isopar" H (Exxon Chemical Co., Ltd.)
A mixture of 140 parts of 2-ethylhexyl methacrylate, 60 parts of benzyl methacrylate, 4 parts of dodecyl mercaptan, and 2 parts of azobisisobutyronitrile was stirred for 1 hour while 490 parts of the mixture were heated and stirred at 90 ° C. After that, a polymerization reaction was carried out while heating and stirring at 90 ° C. for 1 hour. Next, 250 parts of vinyl acetate and methacrylic acid 2-
35 parts of ethylhexyl, 15 parts of benzyl methacrylate,
A mixture of 1 part of benzoyl peroxide was added dropwise over 3 hours, and the mixture was kept at 90 ° C. to advance the polymerization reaction. After the addition, 0.1 part of azobisisobutyronitrile was added three times every hour, and the polymerization was terminated.

The resulting solution was a white emulsion having extremely excellent dispersion stability. The nonvolatile content of this emulsion was 50% by weight. In the above production example, the soluble copolymer segment was a copolymer segment of 140 parts of 2-ethylhexyl methacrylate and 60 parts of benzyl methacrylate, and the insoluble polymer segment was 250 parts of vinyl acetate and 2 parts of methacrylic acid. -Ethylhexyl 3
It is a copolymer segment of 5 parts and benzyl methacrylate.

Example 1 100 parts of the resin obtained in Reference Example 1 700-10 Cyanine Blue 50 parts (Toyo Ink Mfg. Co., Ltd.) Polyglycerin fatty acid ester 2 parts (Kawaken Fine Chemicals KF-750) TP-302 (Hodogaya Chemical Co., Ltd.) 6 parts "ISOPAR" G 150 parts (Esso Chemical Co., Ltd.) After kneading the composition for 5 hours with an attritor, further adding 550 parts of "ISOPAR" G and kneading for 2 hours to obtain a concentrated toner. The developer was obtained after dilution with "Isopar" G. When an electrostatic recording paper having a latent image obtained by the electrostatic recording method was developed using this developer, a clear image without roughness was obtained. Even if printing was continued for 200 sheets with this developer, a clear and reproducible image without roughness was obtained.

Example 2 Resin obtained in Reference Example 1 100 parts Lionol Red 6B FG-4200 30 parts (Toyo Ink Mfg. Co., Ltd.) TP-415 (Hodogaya Chemical Co., Ltd.) 2 parts Octadecyl stearate 5 parts (Japan 100 parts of "Isopar" H (manufactured by Esso Chemical Co., Ltd.) 100 parts of "Isopar" H are kneaded with a vibration ball mill for 3 hours, and then 400 parts of "Isopar" H are further added and kneaded for 1 hour. A concentrated toner was obtained, and 40 parts of the concentrated toner were taken and diluted with 960 parts of "ISOPAR" G to obtain a developer. When an electrostatic recording paper having a latent image obtained by the electrostatic recording method was developed using this developer, a clear image without roughness was obtained. 3
An image with good reproducibility without roughness was obtained even after printing on 00 sheets.

Comparative Example 1 100 parts of resin obtained in Reference Example 1 30 parts of Lionol Red 6B FG-4200 (manufactured by Toyo Ink Mfg. Co., Ltd.) 2 parts of polyglycerin fatty acid ester (KF-750 of Kawaken Fine Chemical Co., Ltd.) 100 parts of Isopar H (manufactured by Esso Chemical Co., Ltd.) A trial production and development of this composition in the same manner as in Example 2 revealed that the image area was rough. After printing 300 sheets, the roughness of the image became worse.

Comparative Example 2 100 parts of resin obtained in Reference Example 1 30 parts of Lionol Red 6B FG-4200 (manufactured by Toyo Ink Mfg. Co., Ltd.) 8 parts of aluminum oxide stearate (Olive AOS manufactured by Hope Pharmaceutical Co., Ltd.) Aluminum Chelate 1 part (ALCH-50 manufactured by Kawaken Fine Chemicals Co., Ltd.) 100 parts "ISOPAR" H (manufactured by Esso Chemical Co., Ltd.) The composition was trial-produced and developed in the same manner as in Example 2, and the toner was fixed at a low print density. Also, after printing 50 sheets, the surface was rough and soiled.

[0037]

According to the present invention, a stable dispersion in which the particles in the liquid toner are dispersed while maintaining a constant particle size can be obtained, and the printed image does not become rough even after long use. A clear image can be obtained. The electrostatic latent image liquid developer of the present invention is suitably used for developing an electrostatic latent image formed by an electrophotographic method or an electrostatic recording method, and particularly, using an ion printer that forms an ion image by an ion flow. Forming an ion pattern on a recording medium, developing according to the ion pattern formation image, and recording information;
It is effectively used as a developer in an ion flow recording method for obtaining an image recording medium.

Claims (6)

[Claims] 1. An electrically insulating aliphatic hydrocarbon solvent,
A liquid developer for an electrostatic latent image, comprising a dispersion stabilizer and a quaternary ammonium salt compound mixed and dispersed in a liquid developer for an electrostatic latent image obtained by dispersing a resin and a colorant. 2. The liquid developer for an electrostatic latent image according to claim 1, wherein the quaternary ammonium salt compound contains an inorganic anion. 3. The liquid developer for an electrostatic latent image according to claim 2, wherein said inorganic anion is a molybdenum or tungsten atom. 4. The resin mainly comprises at least one kind selected from alkyl acrylate and alkyl methacrylate and at least one kind selected from cycloalkyl acrylate, cycloalkyl methacrylate, aralkyl acrylate and aralkyl methacrylate. Consisting of a copolymer segment soluble in an aliphatic hydrocarbon-based solvent as a constituent component and a polymer segment insoluble in an aliphatic hydrocarbon-based solvent containing vinyl acetate as a main constituent, and the aliphatic hydrocarbon-based solvent as a whole The liquid developer for an electrostatic latent image according to claim 1, wherein the liquid developer is a non-gel non-gel copolymer. 5. The dispersion stabilizer is a higher aliphatic polyester having a molecular weight in the range of 1,500 to 100,000 based on polystyrene, or a compound represented by the following general formula 1,
The liquid developer for an electrostatic latent image according to claim 1, wherein the liquid developer is at least one compound selected from the group consisting of 2, 3 and 4. Embedded image Embedded image Embedded image 6. The image forming method according to claim 1, wherein the developer for an electrostatic latent image is used in an image forming method for forming an ion image pattern formed on a recording medium by an ion flow. Developer for electrostatic latent images.