JPH1063039A - Liquid developer for electrostatic latent image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a printed matter free from roughness and having satisfactory image quality and a high image density in an ion flow recording method by specifying the wt. average particle diameter of toner particles or AC conductivity of a developer. SOLUTION: This liq. developer contains at least a resin, a colorant and a dispersant in an electric insulating aliphatic hydrocarbon solvent and has 0.05-0.5μm wt. average particle diameter of toner particles or 20-150pMHO/cm AC conductivity. The hydrocarbon solvent is not especially limited but a solvent having >=10<9> Ω.cm electric resistance, a dielectric constant of <=3 and 68-250 deg.C b.p., e.g. n-hexane, ligroin or a mixture of them is generally used. When this liq. developer is used, printed matter free from roughness and having a high image density is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid developer used for developing an electrostatic latent image formed by an electrophotographic system or an electrostatic recording system. In particular, using an ion printer that forms an ion image by an ion flow, an ion pattern is formed on a recording medium, developed according to the ion pattern-formed image, and information is recorded. Used effectively.

[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 concentrated toner having a non-volatile content of about 1 to 20 wt% is prepared by kneading, and the concentrated toner is prepared by diluting the concentrated toner to have a non-volatile content of about 0.1 to 5 wt%. Developers described in, for example, Sho 62-89971.

[0003]

When full-color printing is performed using such a liquid developer as a developer in a full-color ion flow recording method, the image in a highlight portion is roughened and the print density is insufficient. There was a problem that was not.

It has been presumed that these problems are related to the mobility of toner particles, the amount of charge, and the like.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid developer for an electrostatic latent image capable of obtaining a printed matter having good image quality and high image density without roughness in an ion flow recording method.

[0006]

In order to achieve the above object, a liquid developer for an electrostatic latent image according to the present invention comprises at least a resin, a colorant and a dispersant in an electrically insulating aliphatic hydrocarbon solvent. In the electrostatic latent image liquid developer, the weight average particle diameter of the toner particles is 0.05 to 0.5 μm, or
A liquid developer for an electrostatic latent image, characterized in that the developer has an AC conductivity of 20 to 150 pMHO / cm.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, an electrically insulating aliphatic hydrocarbon solvent is used as a dispersion medium or a carrier liquid for a resin, a colorant, a dispersant and other additives.

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, and 2028 sold by Idemitsu Oil Co., Ltd., and NAS-3 and NAS-4 sold by NOF Corporation are listed as examples. 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.
A non-gel non-gel insoluble in the solvent as a whole, comprising a copolymer segment soluble in an aliphatic hydrocarbon solvent having a main component of at least one kind and a polymer segment insoluble in the solvent having vinyl acetate as a main component. Copolymer.

[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 are preferred. And a copolymer segment with one or more kinds of aralkyl methacrylate and the like. As a polymer segment having vinyl acetate as a main component, a vinyl acetate component is 50 to 100 wt%,
Preferably, a polymer segment or a copolymer segment of 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 carbon atom.
-20, preferably 1-18 alkyl groups, specifically methyl acrylate or methyl methacrylate, ethyl, 2-hydroxyethyl, isobutyl,
Esters such as octyl, stearyl and isononyl are preferably used. The cycloalkyl group of the cycloalkyl acrylate or the cycloalkyl methacrylate herein is not particularly limited, but usually has 6 carbon atoms.
To 8, 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 are mentioned.

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).

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.

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) and the like. The addition amount of the colorant varies depending on the color, but 10 to 50% by weight of the entire nonvolatile component of the developer,
Preferably it is 15 to 45% by weight.

The dispersant used in the present invention may be any as long as it can improve the dispersion stability and storability of the toner. For example, naphthenic acid, octylic acid, stearic acid, alkylphosphoric acid, alkylbenzenesulfonic acid, resin Acids and metal salts of fatty acids are preferably used. Examples of the metal constituting the metal salt include Li, Ca, Ba, Zr, Mn, Co,
Metals such as Ni, Cu, Zn, Cd, 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 include, for example, "Olive" AOS (manufactured by Hope Pharmaceutical), "Olive" AOO (manufactured by Hope Pharmaceutical), lubricant OA-S (manufactured by Kawaken Fine Chemical), and lubricant OA-O (manufactured by Kawaken Fine Chemical) Is particularly preferably used. The amount of the dispersant added is 0.05 to 15 wt.
%, Preferably 0.1 to 12% by weight.

In the present invention, a charge control agent, a higher fatty acid ester, a higher aliphatic polyester, a surfactant and the like may be added in addition to the above-mentioned materials in order to remarkably improve the dispersion stability, storage stability and printing performance of the toner. Good.

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 liquid of a copolymer and a colorant, a dispersant and the above compound are uniformly kneaded with a ball mill, a sand mill, a vibration mill, an attritor or the like in an aliphatic hydrocarbon-based solvent. A concentrated toner having a non-volatile content of about 20% by weight is prepared, and the concentrated toner is prepared using the aliphatic hydrocarbon-based solvent so that the non-volatile content is 0.05 to 5% by weight.
It can be prepared by diluting to a degree.

In the present invention, the particle size of the liquid developer for an electrostatic latent image is an important factor for obtaining a good image. A general liquid developer has a toner particle diameter of about 1 μm. In order to obtain a high-definition image in the ion flow recording method, a small particle size is required. Therefore, the weight average particle size of the toner particles is desirably 0.05 to 0.5 μm.
In order to make the primary particle size of the pigment smaller than 0.05 μm, although the primary particle size of the pigment varies depending on the pigment, it is difficult to make it smaller mechanically. If it exceeds 0.5 μm, a high-definition image cannot be obtained. Although the particle size of the toner particles of this developer varies depending on the color, it is preferably 0.07 to 0.4 μm, more preferably 0.2 to 0.4 μm for yellow. In magenta, 0.05 to 0.4 μm, more preferably 0.1 to 0.4 μm
０．３0.3 μm. For cyan, 0.05 to
It is 0.4 μm, more preferably 0.05 to 0.25 μm. For black, the thickness is preferably 0.07 to 0.4 μm, more preferably 0.1 to 0.4 μm.

The weight-average particle diameter was measured using a centrifugal sedimentation type particle size distribution analyzer, SA-CP3 (manufactured by Shimadzu Corporation). Is taken as the weight average particle diameter.

The toner particles in the measurement of the particle size are a colorant and a colorant to which at least a resin, a dispersant, and the like have adhered.

In the present invention, the AC conductivity as well as the particle size are important factors for obtaining a good image and a high image density with the liquid developer for an electrostatic latent image. If the AC conductivity is low, fixing on the recording medium is poor, causing peeling. If the AC conductivity is too high, electrostatic repulsion between particles is caused, and the image density of the latent image does not increase.

The AC conductivity of the developer is 20 to 150.
pMHO / cm is preferred, and more preferably 35 to 9
0 pMHO / cm.

The suitable value of the AC conductivity is different depending on the color, to be more specific. Yellow has a value of 30 to 100 pMH.
O / cm, more preferably 40 to 70 pMHO / cm. Magenta is 20 to 70 pMHO / cm, more preferably 40 to 70 pMHO / cm. 30 for cyan
-80 pMHO / cm, more preferably 35-75 pM
HO / cm. Black is 30-100 pMHO /
cm, more preferably 40 to 90 pMHO / cm.

The AC conductivity was measured by diluting the developer 24 times by weight with "Isopar" H, and allowing it to stand for 2 days.
ITY METER MODDEL627 (manufactured by Scientifica)
Measure with

The liquid developer of the present invention can develop an electrostatic latent image obtained by an electrophotographic method or an electrostatic recording method, and can be used effectively by using these developers.

The present invention is particularly directed to an ion flow in which an ion pattern is formed on a recording medium using an ion printer for forming an ion image by an ion flow, and development is performed in accordance with the ion pattern-formed image to obtain an information record and an image record pair. It is effectively used as a developer for recording methods. More preferably, it is effectively used as a developer in an ion flow recording method for forming a full-color image.

[0034]

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 (manufactured by Exxon Chemical) 49
0 parts was heated and stirred at 90 ° C., and methacrylic acid 2 was added.
-140 parts of ethylhexyl, benzyl methacrylate 60
, 4 parts of dodecylmercaptan, and 2 parts of azobisisobutyronitrile were added dropwise over 1 hour, and the polymerization reaction was further performed for 1 hour while heating and stirring at 90 ° C. Next, a mixed solution of 250 parts of vinyl acetate, 35 parts of 2-ethylhexyl methacrylate, 15 parts of benzyl methacrylate, and 1 part of benzoyl peroxide was added dropwise over 3 hours, and 90 ° C.
And the polymerization reaction was advanced. 3 times every hour after dropping,
After the addition of 0.1 part of azobisisobutyronitrile, the polymerization was terminated.

The obtained 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 50 parts of Lionol Red 6B FG-4200 (manufactured by Toyo Ink Co., Ltd.) 10 parts of aluminum oxide stearate ("Olive" AOS manufactured by Hope Pharmaceutical Co., Ltd.) 6 parts of octadecyl stearate ( 150 parts of Isopar H (manufactured by Esso Chemical) is kneaded for 5 hours with a vibration mill (manufactured by B-3 type Chuo Kakoki), and then 400 parts of Isopar H is added and kneaded for 1 hour. A concentrated toner was obtained, and 40 parts of the concentrated toner were taken and diluted with 800 parts of "ISOPAR" G to obtain a developer.

Example 2 Instead of 10 parts of octadecyl stearate in Example 1, a higher aliphatic polyester (KF manufactured by Kawaken Fine Chemicals Co., Ltd.) was used.
(-1000) 1.5 parts was used to produce a trial product in the same manner to obtain a developer.

Example 3 A trial product was prepared in the same manner as in Example 1 except that the addition amount of aluminum oxide stearate was changed to 6 parts and no stearyl stearate was added.

Comparative Example 1 A pigment was prepared in the same manner as in Example 3 using Carmine 6B623 (manufactured by Dainichi Seika) to obtain a developer.

Comparative Example 2 A pigment was prepared in the same manner as in Example 3 by using Carmine 6B236 (manufactured by Dainichi Seika) to obtain a developer.

Example 4 100 parts of the resin obtained in Reference Example 1 40 parts of Fine Yellow G-20 S-12E (manufactured by Toyo Ink) 15 parts of aluminum oxide stearate (manufactured by Hope Pharmaceutical "Olive" AOS) Polyhydric alcohol fatty acid Ester 5 parts (Kawaken Fine Chemical KF-750) "Isopar" G 120 parts (manufactured by Esso Chemical) The above composition was prototyped in the same manner as in Example 1 to obtain a developer.

Example 5 A developer was prepared in the same manner as in Example 4 except that the polyhydric alcohol fatty acid ester was not added and 15 parts of aluminum oxide stearate was used in 10 parts.

Comparative Example 3 A pigment was prepared in the same manner as in Example 5 by using Lionol Yellow GR to obtain a developer.

Comparative Example 4 The polyhydric alcohol fatty acid ester of Example 4 and aluminum oxide stearate were not added, and 15 parts of aluminum tris-ethyl acetoacetate (ALCH-TR-20 manufactured by Kawaken Fine Chemicals) was added. A developer was obtained.

Comparative Example 5 In place of aluminum tris-ethyl acetoacetate of Comparative Example 4, aluminum bisethyl acetoacetate monoacetylacetonate (aluminum chelate D manufactured by Kawaken Fine Chemicals) was added, and a prototype was obtained in the same manner to obtain a developer.

Example 6 100 parts of the resin obtained in Reference Example 1 700-10 Cyanine Blue 50 parts (Toyo Ink Manufacturing Co., Ltd.) Aluminum oxide stearate 10 parts (Hope Pharmaceutical "Olive" AOS) Polyhydric alcohol fatty acid ester 6 parts (Kawaken Fine Chemical KF-750) "Isopar" H 150 parts (Manufactured by Esso Chemical) A developer was obtained in the same manner as in Example 1 except that the above composition was used.

Example 7 Instead of the polyhydric alcohol fatty acid ester of Example 6, octadecyl stearate (Unistar M-9 manufactured by NOF Corporation) was used.
676) to produce a developer.

Example 8 A trial product was prepared in the same manner as in Example 6 except that the addition amount of the aluminum oxide stearate was 12.5 parts and no polyhydric alcohol fatty acid ester was added.

Comparative Example 6 A prototype was produced in the same manner as in Example 8 except that the kneading for 5 hours was changed to the kneading for 1 hour to obtain a developer.

Example 9 120 parts of the resin obtained in Reference Example 1 35 parts of carbon black MA-100 (manufactured by Mitsubishi Kasei Kogyo) 50 parts of "Bontron" N-07 50 parts (manufactured by Orient Chemical Industries) 6 parts of aluminum oxide stearate (Hope Pharmaceutical “Oripu” AOS) 10 parts of octadecyl stearate (Unistar M-9676 manufactured by NOF CORPORATION) 150 parts of “ISOPAR” H (manufactured by Esso Chemical) A developer was obtained in the same manner as in Example 1 with the above composition.

Example 10 Instead of octadecyl stearate of Example 9, a higher aliphatic polyester (KF-10 manufactured by Kawaken Fine Chemicals) was used.
(00) was prepared in the same manner as above using 1.5 parts to obtain a developer.

Comparative Example 7 A trial product was prepared in the same manner as in Example 10 except that the amount of the higher aliphatic polyester added was changed to 6 parts to obtain a developer.

Table 1 shows the AC conductivity, the average particle size, and the printing results of Examples 1 to 10 and Comparative Examples 1 to 7.

[0055]

[Table 1]

[0056]

As described above, by using the liquid developer of the present invention, it is possible to provide a liquid developer for an electrostatic latent image capable of obtaining a printed matter having good image quality and high image density without roughness.

Claims (4)

[Claims] 1. A liquid developer for an electrostatic latent image containing at least a resin, a colorant and a dispersant in an electrically insulating aliphatic hydrocarbon solvent, wherein the toner particles have a weight average particle diameter of 0.05 to 0.05.
A liquid developer for an electrostatic latent image, which is 0.5 μm. 2. An electrostatic latent image liquid developer containing at least a resin, a colorant and a dispersant in an electrically insulating aliphatic hydrocarbon solvent, wherein the developer has an AC conductivity of 20 to 150 pMH.
A liquid developer for an electrostatic latent image, wherein the developer is O / cm. 3. A liquid developer for an electrostatic latent image containing at least a resin, a colorant and a dispersant in an electrically insulating aliphatic hydrocarbon solvent, wherein the toner particles have a weight average particle diameter of 0.05 to 0.05.
0.5 μm, and the AC conductivity of the developer is 20 to 150 μm.
A liquid developer for electrostatic latent images, which has a pMHO / cm. 4. The electrostatic latent image liquid developer according to claim 1, which is used in an image forming method for forming an ion image pattern formed on a recording medium by an ion flow.