JP2001139857A - Oil-based ink for electrostatic ink jet recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an oil-based ink for electrostatic ink jet recording excellent in ink-jetting stability, clear image-forming properties and image strength and capable of forming a printing plate permitting to print a large number of printed matters having a clear image. SOLUTION: The oil-based ink for an electrostatic ink jet recording comprises copolymer resin particles dispersed in a non-aqueous carrier liquid having an electrical resistance of at least 109 Q.cm and a dielectric constant of 3.5 or less, the copolymer resin particles being obtained by subjecting to polymerization and granulation a solution containing a monofunctional monomer (A) soluble in the non-aqueous solvent and insolubilized therein when polymerized, a monofunctional monomer (B) bearing an amino group and copolymerizable with the monomer A, a monofunctional monomer (C) bearing an -SO3H group and/or an -SO2H group and copolymerizable with the monomer A, and a star copolymer [P] having a specific structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil-based ink for an electrostatic ink jet used for forming an image by an electrostatic (electrostatic attraction or electrostatic attraction) ink jet recording system.

[0002]

2. Description of the Related Art Ink jet recording is a recording method capable of high-speed printing with low noise, and is a recording method that has been rapidly spreading recently. Ink jet recording is a method in which a liquid ink having a high fluidity is ejected from fine nozzles and is recorded on recording paper, and there are an on-demand (optional ejection) and a continuous (continuous ejection) method. Further, a recording method called an electrostatic method (Sweet type or Hertz type) is known as a continuous type, and a piezo piezoelectric method, a thermal inkjet method, or an electrostatic acceleration type is known as an on-demand type.

As an on-demand type ink jet system using electrostatic force, Susumu Ichinose, Yuji Ohba, IEICE Transactions vol.J66-C (No.1), p47 (1983), Tadayoshi Ohno, Mamoru Mizuguchi, The Institute of Image Electronics Engineers of Japan Journal vol.10, (No.3), p157 (1981) and the like, a system called an electrostatic pressurized ink jet or a slit jet is known.Specific embodiments are, for example, JP-A-56-170, No. 56-4467, No. 5
No. 7,151,374. This involves supplying ink to a slit-shaped ink chamber in which a large number of electrodes are arranged on the inner surface of a slit-shaped ink holding unit from an ink tank, and selectively applying a high voltage to these electrodes to form a slit-shaped ink chamber. Ink is recorded by ejecting ink near the electrodes onto the recording paper that is in close proximity.

As another system which does not use a slit-shaped recording head, Japanese Patent Application Laid-Open No. 61-2111048 discloses a method in which ink is filled in a hole of a film-shaped ink support having a plurality of minute holes and a multi-needle is provided. There is disclosed means for selectively applying a voltage by an electrode to move ink in a hole to recording paper.

[0005] The principle of the flight of these inks is that a high voltage applied to the arranged electrodes causes electric charges to be injected into the ink in contact with the electrodes, and the ink near the electrodes to be charged, thereby generating an electrostatic force. It is interpreted that ink is ejected. Therefore, the ink is not normally charged, and only when a voltage is applied, the ink near the electrodes is charged by energization to obtain a discharging force. Inks used in these methods have an electric resistance of about 10 ⁶ to 10 ⁸ Ω · cm. Since water has a low electric resistance, a material in which a colorant composed of a dye is dispersed in an oily solvent with a dispersing aid such as a surfactant to adjust the electric resistance is generally used.

Further, a method of controlling the viscosity and specific resistance of the oil-based ink used (Japanese Patent Publication No. 52-13127).
), A method of controlling the relative permittivity of the dispersion medium used for the ink and the specific resistance of the ink (JP-A-53-29808), changing the type of the dispersion medium of the oil-based ink, or using a specific compound as the ink composition. Method for containing (JP-A-3-79
677, JP-A-3-64377, JP-A-4-202
386, JP-A-7-109431) and the like. However, these prior arts are not suitable for the storage stability of oil-based ink, the reproducibility of recorded images after repeated use, the bleeding resistance of the ink on the ink receiving material, the clogging resistance in the nozzle and the ink supply path, and the ink. Discharge stability and the like are not yet sufficiently satisfactory, and further improvement in performance is desired.

On the other hand, another electrostatic ink jet technology is
It is disclosed in WO93 / 11866. In this method, an insulating liquid is supplied to an ink ejection device with ink in which charged particles or particles exhibiting chargeability under an electric field are dispersed, and an ink meniscus is formed at an ejection electrode tip for ejecting the ink. It has a series of steps of forming an electric field between a counter electrode on which a recording medium is mounted and an ejection electrode to fly aggregated particles by electrophoresis and concentrating the particle concentration in the ink meniscus. I have.

[0008] Unlike the conventional method, the feature of this method that does not require an ink nozzle structure is that an ink containing dispersed particles such as a pigment can be ejected in a fine droplet size of about several μm. It is possible to change the dot size of an image by changing the droplet size by controlling the ejection signal, and the like. Accordingly, it is possible to draw an image based on the light- and water-resistant pigment and form a clear image of a continuous halftone image at high resolution and high density.

The oily ink used has an electric resistance value of 1
0 ⁹ Ω · cm while more insulating liquid and chargeable particles insoluble ones of the content containing the charge agent WO95 / 140
No. 4, WO 96/10058. Further, those in which the charge amount of charged particles or the average particle size of the particles is specified (Japanese Patent Application Laid-Open Nos. 9-193389 and 8-291)
No. 267) or those in which the thermophysical properties of a dried ink composition are specified (Japanese Patent Application Laid-Open No. 9-137094).

However, when ink-jet recording is performed using these oil-based inks, instability of ink ejection or insufficient concentration of pigment particles in the ink occurs, resulting in lack of formed images and blurring of images. Or an insufficient image density (particularly, a solid image portion). In addition, when the ink that has been stored for a long time is used, the ejection conditions (applied voltage, etc.) vary with the case of using fresh ink, and the ratio of concentrated and ejected ink changes significantly. In such a case, a problem such as change occurs.

On the other hand, with the recent development of office equipment and the progress of OA, in the field of light printing, lithographic printing plate precursors having an image receiving layer on a water-resistant support are subjected to plate making, that is, image formation by various methods. A plate making method for creating an offset printing plate has become widespread, and as one of the plate making methods, plate making is performed by an ink jet method. Using a conventional oil-based ink, when a printing plate on which a clear image was formed was actually printed, the number of prints at which a clear printed matter could be obtained without missing the image portion was at most several hundred sheets,
It was not enough. That is, the offset printing has a problem that the fixing strength of an image composed of ink particles is insufficient.

Accordingly, an object of the present invention is to provide an oil-based ink for electrostatic ink jet which is excellent in ink ejection stability, clear image forming property and image strength. Another object of the present invention is to provide an oil-based ink for electrostatic ink jet which can form a printing plate capable of printing a large number of prints of a clear image. Another object of the present invention is to provide an oil-based ink for an electrostatic ink jet, which is excellent in dispersibility and storage stability of dispersed particles, is not clogged in an ink supply path, and has stable ink ejection.

[0013]

It has been found that the above-mentioned object is achieved by the following constitutions.

(1) An oil-based ink for electrostatic ink jet, comprising at least charged resin particles dispersed in a non-aqueous carrier liquid having an electric resistance of 10 ⁹ Ω · cm or more and a dielectric constant of 3.5 or less. The resin particles are soluble in a non-aqueous solvent and contain at least one monofunctional monomer (A) which becomes insoluble by polymerization, and an amino group represented by the general formula (I), at least one monomer (a) copolymerizable with the monofunctional monomer (B), containing a -SO ₃ H group and / or -SO ₂ H group, copolymerized with the monomer (a) Copolymer obtained by polymerizing and granulating a solution containing at least one possible monofunctional monomer (C) and at least one dispersion stabilizing resin [P] soluble in the non-aqueous solvent. Resin particles, wherein the dispersion stabilizing resin [P] is A star-type copolymer in which at least three of the AB-type block polymer chains composed of lactone A and block B are bonded to organic residues, and
The B-type block polymer chain is bonded to the organic residue at one end of the block A, and the weight average molecular weight of the star copolymer is 2 × 10 ⁴ to 1 × 10 ⁶ , and the block A is
At least one polymer component corresponding to the monofunctional monomer (A) and a phosphono group, a carboxyl group, a sulfo group, a hydroxyl group, a formyl group, an amino group, -P (=
O) (OH) E ¹ group, [E ¹ represents -E ² group or -OE ² group, and E ² represents hydrocarbon group], -CONE ³ E ⁴ group,
A polymer containing at least one polar group selected from —SO ₂ NE ³ E ⁴ groups (E ³ and E ⁴ each independently represent a hydrogen atom or a hydrocarbon group) and a cyclic acid anhydride-containing group An oil-based ink for electrostatic inkjet, characterized in that the block B has at least one polymer component selected from the following components, and the block B contains at least one polymer component represented by the following general formula (II).

[0015]

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In the general formula (I), R ¹ and R ² may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms, or R ¹ and R ² are bonded to each other. A ring may be formed together with the nitrogen atom.

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In the general formula (II), X ¹ is -COO-, -OC
_{O -, - (CH 2)} x COO -, - (CH 2) x OCO-
[Where x represents an integer of 1 to 3], or -O-. Y ¹ represents an aliphatic group having 8 or more carbon atoms. b ¹ and b
² may be the same or different, and each is a hydrogen atom,
A halogen atom, a cyano group, a hydrocarbon group having 1 to 7 carbon atoms,
—COO—Z ¹ , or —COO— through a hydrocarbon group.
Z ¹ (wherein Z ¹ represents a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms).

(2) In the dispersion stabilizing resin [P], each block of the AB block copolymer component constituting each polymer chain has a block A / block B ratio of 1 to 50 /. The oil-based ink for electrostatic inkjet according to the above (1), which has a mass ratio of 99 to 50.

(3) The dispersed resin particles further contain at least one monofunctional monomer (D) represented by the following general formula (IV) copolymerizable with the monomer (A). (1) or (2), wherein the oil-based ink for electrostatic inkjet is a copolymer resin particle obtained by polymerizing and granulating a solution to be obtained.

[0020]

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In the general formula (IV), U ¹ is -COO-, -C
^{ONH -, - CON (D 2} ) - ( wherein, D ² represents a substituent represented by the aliphatic group or a group represented by the general formula (Va)),
-OCO -, - CONHCOO -, - CH 2 COO-,
— (CH ₂ ) _S OCO—, where s represents an integer of 1 to 4, —O— or —C ₆ H ₄ —COO—. c ¹
And c ² are the same or different, each represents a hydrogen atom, an alkyl group, a halogen atom, a cyano group, -COO-D ³ or -CH ₂ COO-D ³ (wherein D ³ represents an aliphatic group) . E ¹ is an aliphatic group having 8 or more carbon atoms or a group having a total number of 8 or more atoms (excluding a hydrogen atom directly bonded to a carbon atom or a nitrogen atom), which is represented by the following general formula (IVa). Represent. Formula (IVa)-(A ¹ -B ¹ ) _m- (A ² -B ² ) _n -R ^{21 In the} general formula (IVa), R ²¹ is a hydrogen atom or a group having 1 to 1 carbon atoms.
8 represents an aliphatic group. B ¹ and B ² are the same or different and are each -O-, -S-, -CO-, -CO ₂ -,-
_{OCO -, - SO 2 -,} - N (R 22) -, - CON (R
^{22) -, - N (R} 22) CO -, - N (R 22) SO 2 -,
^{_{SO 2 N (R 22) -}} , - NHCO 2 - or -NHCON
Represents H- (here, R ²² has the same meaning as R ²¹ above).
A ¹ and A ² are the same or different and each represent at least one group selected from a group represented by the following formula (IVb) and a hydrocarbon group having 1 to 18 carbon atoms. m and n are the same or different and each represents an integer of 0-4. However, there is no possibility that m + n = 0.

[0022]

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In the general formula (IVb), B ³ and B ⁴ are the same or different and have the same meanings as B ¹ and B ² above, A ⁴ represents a hydrocarbon group having 1 to 18 carbon atoms, and R ²³ It has the same meaning as above R ^21. p represents an integer of 0 to 4.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION The oil-based ink for electrostatic ink jet of the present invention will be described below. The non-aqueous 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 is preferably a linear or branched aliphatic hydrocarbon, alicyclic hydrocarbon, or aromatic hydrocarbon. Hydrogen, halogen-substituted forms of these hydrocarbons, and silicone liquids;
Examples include silicone solvents such as silicone oil.

For example, hydrocarbon solvents include pentane, isoheptane, octane, isooctane, decane,
Isodecane, decalin, nonane, dodecane, isododecane, cyclohexane, cyclooctane, cyclodecane,
Benzene, toluene, xylene, mesitylene, Isopar E, Isopar G, Isopar H, Isopar L (Isoper; trade name of Exxon), Shellsol 70,
Shellsol 71 (Shellsol; trade name of Shell Oil), Amsco OMS, Amsco 460 solvent (Amsco; trade name of Spirits) and the like.

As the halogen-substituted hydrocarbon solvent, there is a fluorocarbon solvent. For example, perfluoroalkanes represented by C _n F _{2n + 2} such as C ₇ F ₁₆ and C ₈ F ₁₈ (“Fluorinert” manufactured by Sumitomo 3M) PF5080 "," Florinert PF5070 "(trade name), fluorinated inert liquid (" Fluorinert FC series "(trade name) manufactured by Sumitomo 3M), fluorocarbons (" Crytox GPL series manufactured by DuPont Japan Limited ") "(Trade name) etc.), CFCs (" HCF "manufactured by Daikin Industries, Ltd.)
C-141b ”(trade name) etc., [F (CF ₂ ) ₄ CH
₂ CH ₂ I], and the like _{[F (CF 2) 6 I} ] iodinated fluorocarbons such as (Daikin Fine Chemical Laboratory, Ltd., "I-1420", "I-1600" (trade name), etc.).

As the silicone solvent for the silicone liquid and silicone oil, dialkylpolysiloxanes (for example, hexamethyldisiloxane, tetramethyldisiloxane, octamethyltrisiloxane, hexamethyltrisiloxane, heptamethyltrisiloxane, decamethyltetrasiloxane, Trifluoropropyl heptamethyltrisiloxane, diethyltetramethyldisiloxane, etc.), cyclic dialkylpolysiloxane (for example, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane,
Examples thereof include tetra (trifluoropropyl) tetramethylcyclotetrasiloxane and the like, methylphenyl silicone oil (for example, KF56, KF58 (trade name, manufactured by Shin-Etsu Silicon Co., Ltd.)) and the like.

In the present invention, these solvents are used alone or as a mixture. The upper limit of the electric resistance of such a non-aqueous carrier liquid is preferably about 10 ¹⁶ Ω · cm, and the lower limit of the dielectric constant is preferably about 1.80.

The non-aqueous dispersed resin particles (hereinafter sometimes referred to as dispersed resin particles or latex particles), which are the most important components in the oil-based ink of the present invention, are a non-aqueous solvent containing a specific component. A monofunctional monomer having an amino group represented by the general formula (I), in the presence of a dispersion stabilizing resin [P] which is a type copolymer. (B) of those obtained by at least one and -SO ₃ H groups and / or at least one polymerization granulation -SO ₂ H group and containing to monofunctional monomer (C).

Here, as the non-aqueous solvent, basically,
Any ink that can be mixed with the non-aqueous carrier liquid of the oil-based ink can be used.

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, an alicyclic hydrocarbon, or an aromatic hydrocarbon. Group hydrocarbons and their halogen-substituted products. For example, octane, isooctane, decane, isodecane, decalin, nonane,
Dodecane, isododecane, isoper E, isoper G, isoper H, isoper L, shelsol 70,
Shellsol 71, AMSCO OMS, AMSCO 460 solvent and the like are used alone or in combination.

Organic solvents which can be used in combination with these non-aqueous solvents include alcohols (eg, ethyl alcohol, propyl alcohol, butyl alcohol,
Ethylene glycol monomethyl ether, fluorinated alcohols, etc., ketones (eg, methyl ethyl ketone, acetophenone, cyclohexanone, etc.), carboxylic esters (eg, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate) , Ethylene glycol monomethyl ether acetate, etc.), ethers (eg, dipropyl ether, ethylene glycol dimethyl ether, tetrahydrofuran, dioxane, etc.), halogenated hydrocarbons (eg,
Chloroform, dichloroethane, methyl chloroform and the like).

It is desirable that the organic solvent used by mixing these is distilled off under heating or reduced pressure after polymerization granulation. However, even if the organic solvent is brought into an oil-based ink as a latex particle dispersion, the resistance of the ink is reduced. There is no problem as long as the conditions of not less than 10 ⁹ Ω · cm and permittivity of not more than 3.5 can be satisfied.

Usually, it is preferable to use the same solvent as the carrier liquid at the stage of preparing the resin dispersion, and as described above, a linear or branched aliphatic hydrocarbon, alicyclic hydrocarbon,
Examples include aromatic hydrocarbons and halogenated hydrocarbons.

The monofunctional monomer (A) in the present invention comprises:
Any monofunctional monomer that is soluble in a nonaqueous solvent but insolubilized by polymerization may be used. Specifically, for example, a monomer represented by the following general formula (V) can be mentioned.

[0036]

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In the general formula (V), V ¹ represents —COO—, —O
_{CO -, - CH 2 OCO -} , - CH 2 COO -, - O-,
-CONHCOO-, -CONHOCO-, -SO
^{_{2 -, - CON (Q 1}} ) -, - SO 2 N (Q 1) -., Or a phenylene group (hereinafter sometimes to be referred to as a phenylene group and "-Ph-" Incidentally, phenylene group 1,2 -, 1,
Includes 3- and 1,4-phenylene groups. ). Here, Q ¹ represents a hydrogen atom or an optionally substituted aliphatic group having 1 to 8 carbon atoms (for example, a methyl group, an ethyl group, a propyl group, a butyl group, a 2-chloroethyl group,
-Bromoethyl group, 2-cyanoethyl group, 2-hydroxyethyl group, benzyl group, chlorobenzyl group, methylbenzyl group, methoxybenzyl group, phenethyl group, 3-phenylpropyl group, dimethylbenzyl group, fluorobenzyl group, 2-methoxy Ethyl group, 3-methoxypropyl group, etc.).

T represents a hydrogen atom or an optionally substituted aliphatic group having 1 to 6 carbon atoms (eg, methyl, ethyl, propyl, butyl, 2-chloroethyl, 2,2-dichloroethyl, 2-bromoethyl group, 2-hydroxyethyl group, 2-hydroxypropyl group, 2,3-dihydroxypropyl group, 2-hydroxy-3-chloropropyl group, 2-cyanoethyl group, 3-cyanopropyl group, 2
-Nitroethyl group, 2-methoxyethyl group, 2-methanesulfonylethyl group, 2-ethoxyethyl group, 3-bromopropyl group, 4-hydroxybutyl group, 2-furfurylethyl group, 2-thienylethyl group, 2- Carboxyethyl group, 3-carboxypropyl group, 4-carboxybutyl group, 2-carboxyamidoethyl group, 2-N-methylcarboxyamidoethyl group, cyclopentyl group, chlorocyclohexyl group, dichlorohexyl group, etc.).

A ¹ and a ² may be the same or different from each other, and are preferably a hydrogen atom, a halogen atom (eg, chlorine atom, bromine atom, etc.), a cyano group, and a carbon number of 1 to 3.
Alkyl group (e.g. methyl group, ethyl group, propyl group, etc.), - COO-Q ² or -CH ^₂ -COO-Q ₂ [wherein Q ² is 1 hydrogen atom or a carbon atoms which may be substituted,
And 0 or less hydrocarbon groups (for example, representing an alkyl group, an alkenyl group, an aralkyl group, an aryl group, etc.).

Specific examples of the monofunctional monomer (A) include:
For example, vinyl esters or allyl esters of aliphatic carboxylic acids having 1 to 6 carbon atoms (acetic acid, propionic acid, butyric acid, monochloroacetic acid, etc.); unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, and maleic acid Alkyl esters or amides of carboxylic acid having 1 to 4 carbon atoms which may be substituted. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a 2-chloroethyl group, a 2-bromoethyl group and a 2-hydroxy group. Ethyl group, 2-cyanoethyl group, 2-nitroethyl group, 2-methoxyethyl group, 2-methanesulfonylethyl group, 2-
Benzenesulfonylethyl group, 2-carboxyethyl group, 4-carboxybutyl group, 3-chloropropyl group,
2-hydroxy-3-chloropropyl group, 2-furfurylethyl group, 2-thienylethyl group, 2-carboxyamidoethyl group, etc .;

Styrene derivatives (for example, styrene, vinyltoluene, α-methylstyrene, vinylnaphthalene,
Chlorostyrene, dichlorostyrene, bromostyrene,
Vinylbenzenecarboxylic acid, chloromethylstyrene, hydroxymethylstyrene, methoxymethylstyrene, vinylbenzenecarboxamide, vinylbenzenesulfonamide, etc.); acrylic acid, methacrylic acid, crotonic acid,
Unsaturated carboxylic acids such as maleic acid and itaconic acid; cyclic acid anhydrides such as maleic acid and itaconic acid; acrylonitrile; methacrylonitrile; a heterocyclic compound containing a polymerizable double bond group (specifically, for example, a polymer Academic Society, "Polymer Data Handbook -Basic Edition-", p.175-184,
Compounds described in Baifukan (1986), for example, N-
Vinylpyridine, N-vinylimidazole, N-vinylpyrrolidone, vinylthiophene, vinyltetrahydrofuran, vinyloxazoline, vinylthiazole, N-vinylmorpholine and the like.

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

Next, the monofunctional monomer (B) used in the present invention will be described. The monofunctional monomer (B) is a monomer containing an amino group represented by the general formula (I) and copolymerizable with the monomer (A). In the monofunctional monomer (B), the polymerizable double bond and the amino group are not directly bonded.

In the formula (I), R ¹ and R ² may be the same or different, and are preferably a hydrogen atom or a carbon atom having 1 to 2 carbon atoms.
2 optionally substituted alkyl groups (for example, methyl group,
Ethyl group, propyl group, butyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, dodecyl group,
Tridecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, docosyl, 2-chloroethyl, 2-bromoethyl, 2-cyanoethyl, 2
-Methoxycarbonylethyl group, 2-methoxyethyl group, 3-bromopropyl group and the like, and an optionally substituted alkenyl group having 4 to 18 carbon atoms (eg, 2-methyl-1-
Propenyl group, 2-butenyl group, 2-pentenyl group, 3
-Methyl-2-pentenyl group, 1-pentenyl group, 1-
Hexenyl group, 2-hexenyl group, 4-methyl-2-hexenyl group, decenyl group, dodecenyl group, tridecenyl group, hexadecenyl group, octadecenyl group, linolenyl group, etc.),

An optionally substituted aralkyl group having 7 to 12 carbon atoms (for example, benzyl, phenethyl, 3-phenylpropyl, naphthylmethyl, 2-naphthylethyl, chlorobenzyl, bromobenzyl, methyl A benzyl group, an ethylbenzyl group, a methoxybenzyl group, a dimethylbenzyl group, a dimethoxybenzyl group, etc., an alicyclic group having 5 to 8 carbon atoms which may be substituted (for example, a cyclohexyl group, a 2-cyclohexylethyl group, A cyclopentylethyl group or the like, or an optionally substituted aromatic group having 6 to 12 carbon atoms (eg, phenyl, naphthyl, tolyl, xylyl, propylphenyl, butylphenyl, octylphenyl, dodecylphenyl) , Methoxyphenyl, ethoxyphenyl, butoxyphenyl, decylio Shifeniru group, chlorophenyl group,
Dichlorophenyl, bromophenyl, cyanophenyl, acetylphenyl, methoxycarbonylphenyl, ethoxycarbonylphenyl, butoxycarbonylphenyl, acetamidophenyl, propionamidophenyl, dodecyloylamidophenyl, etc.)
Is mentioned.

R ¹ and R ² may combine with each other to form a ring together with a nitrogen atom, and specifically may contain a hetero atom (for example, an oxygen atom, a nitrogen atom, a sulfur atom, etc.). Represents a ring-forming organic residue. Examples of the formed cyclic amino group include a morpholino group, a piperidino group, a pyridyl group, an imidazolyl group, and a quinolyl group. A plurality of these amino groups may be contained in the molecule of the monomer (B). The resin particles of the present invention contain an amino group-containing monomer (B) as a copolymerization component, so that the particles have an electric detection property, the charge amount of the particles increases, and environmental conditions (low temperature / low humidity to low (High temperature / high humidity) or long-term storage greatly reduces the change in charging characteristics. As a result,
The formed image has a stable image quality. The monomer (B) is preferably used in an amount of 1 to 45% by mass, more preferably 5 to 30% by mass, based on the total amount of the monomer (A).

The following are specific examples of the monomer (B).
The present invention is not limited to these.

[0048]

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Next, the monofunctional monomer (C) used in the present invention will be described. The monofunctional monomer (C) is-
It is a monomer containing an acidic group selected from SO ₃ H group and —SO ₂ H group and copolymerizable with the monomer (A). The monomer (C) may contain a plurality of the above acidic groups in the molecule. The monomer (C) complements the effect of the monomer (B), further improves the charge characteristics of the resin particles, and acts to always provide a stable and excellent image. The monomer (C) is preferably used in a molar ratio of monomer (B) / monomer (C) of preferably 0.1%.
It is used in the range of 2 to 2.5, more preferably 0.5 to 2.0.

The following are specific examples of the monomer (C).
The present invention is not limited to these.

[0051]

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[0052]

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Next, in the present invention, a monofunctional compound having a specific substituent represented by the above general formula (IV), which is preferably copolymerizable with the monomer (A), is preferably used as a copolymer component of the resin particles. The functional monomer (D) will be described.

First, the case where E ¹ represents an aliphatic group having 8 or more carbon atoms in the general formula (IV) will be described in detail. As the aliphatic group having 8 or more carbon atoms of E ¹ , preferably an alkyl group having 10 or more carbon atoms which may be substituted or an alkenyl group having 10 or more carbon atoms which may be substituted is preferable.

U ¹ is preferably -COO-, -CON
^{H -, - CON (E 2} ) - ( wherein, E ² is preferably aliphatic group (the aliphatic group of 1 to 32 carbon atoms, such as alkyl groups, and the like alkenyl group or an aralkyl group) Or a substituent represented by the formula (IVa)), —OCO—, —CH ₂ OCO— or —O—.

C ¹ and c ² are the same or different and
Preferably a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, a cyano group, a methyl group, -COO-E ³ or -CH ₂
Represents COO-E ³ (however, E ³ preferably represents an alkyl group, alkenyl group, aralkyl group or cycloalkyl group having 32 or less carbon atoms).

In the formula (IV), U ¹ is -COO-, -CON
H- or -CON (E ²⁾ - represents, c ¹ and c
More preferably, ² is the same or different and represents a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group or a methyl group.

In the above monomer (D) represented by the general formula (IV), when E ¹ represents an aliphatic group having 8 or more carbon atoms, specific examples thereof include: 32 aliphatic groups (the aliphatic group may contain a substituent such as a halogen atom, a hydroxyl group, an amino group, or an alkoxy group;
Or an oxygen atom, a sulfur atom, a hetero atom such as a nitrogen atom, and the like, and a carbon atom-carbon atom bond in its main chain may be interposed).
Esters of unsaturated carboxylic acids such as chloroacrylic acid, α-cyanoacrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid (for example, aliphatic groups such as decyl, dodecyl, tridecyl, tetradecyl,
Hexadecyl group, octadecyl group, docosyl group, dodecenyl group, hexadecenyl group, oleyl group, linoleyl group, docosenyl group, etc.); amides of the above-mentioned saturated carboxylic acids (the same as those shown in the above-mentioned esters as the aliphatic group) Vinyl esters or allyl esters of higher fatty acids (higher fatty acids include, for example, lauric acid, myristic acid, stearic acid, oleic acid, linoleic acid, behenic acid, etc.); or total carbon Vinyl ethers in which several 10 to 32 aliphatic groups are bonded to an oxygen atom (the aliphatic groups include the same aliphatic groups as those exemplified for the above unsaturated carboxylic esters) and the like. .

In the monomer (D) represented by the general formula (IV), E ¹ has a total number of atoms of 8 or more (excluding a hydrogen atom directly bonded to a carbon atom or a nitrogen atom).
The case of representing the substituent represented by a) will be described in detail.

A ¹ and A ² are the same or different and
It represents at least one group selected from the group represented by the general formula (IVb) and the hydrocarbon group having 1 to 18 carbon atoms. Here, when two or more groups are selected, it represents a group in which these two or more groups are bonded. Specifically, A ¹ and A ² are, for example, —C (R ²⁴ ) (R ²⁵ ) —
(Where R ²⁴ and R ²⁵ are the same or different and each represent a hydrogen atom, an alkyl group, a halogen atom, etc.),-
(CH = CH) -, cyclohexylene group (hereinafter, a cyclohexylene group - expressed in, "" -C ₆ H ₁₀ "- C ₆ H ₁₀
-"Includes 1,2-cyclohexylene group, 1,3-cyclohexylene group, 1,4-cyclohexylene group), and any combination of atomic groups such as the group represented by the general formula (IVb). It is composed.

When E ¹ represents a substituent represented by the general formula (IVa) having a total of 8 or more atoms, the bonding group (—U ¹ ) in the formula (IV)
-(A ¹ -B ¹ ) _m- (A ² -B ² ) _n -R ²¹ )
A “linking main chain” composed of U ¹ to R ²¹ (that is, U ¹ , A ¹ , B ¹ , A ² , B ² and R ²¹ ) has a total number of atoms constituting the linking main chain of 8 It is preferable that it is above.

Here, the number of atoms constituting the “linking main chain” means, for example, when U ¹ represents —COO— or —CONH—, an oxo group (＝ O group) or a hydrogen atom The carbon atoms, ether-type oxygen atoms, and nitrogen atoms that constitute the connecting main chain are included in the number of atoms. Therefore, -COO- and -CONH- have 2 atoms.
Counted as At the same time, when R ²¹ represents —C ₉ H ₁₉ , a hydrogen atom is not included in the number of atoms, and a carbon atom is included. Therefore, in this case, it is counted as 9 atoms.

Here, U ¹ represents —CON (E ² ) —, and E ² represents a substituent represented by the general formula (IVa), that is, (− (A ¹ -B ¹ ) _m- (A ² -B ²⁾ when it represents an _n -R ^21), also connected backbone consists of E ² contained in the "binding main chain". Moreover A ^1, A ² is the formula (-B in case of having a group represented by ^{(IVb) 3 - (A 4} -B 4) p-R
²³ ) The group is also included in the aforementioned “linking main chain”.

In the above monomer (D) represented by the general formula (IV), when E ¹ represents a substituent represented by the general formula (IVa), specific examples include the following compounds. Can be mentioned.

The following formulas (D-1) to (D-19)
Here, each symbol represents the following contents. r ₁ : —H, —CH ₃ , —Cl or —CN, r ₂ : —H or —CH ₃ l: an integer of 2 to 10, p: an integer of 2 to 6, q: an integer of 2 to 4, m : An integer of 1 to 12, n: an integer of 4 to 18,

[0066]

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[0067]

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[0068]

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The use of the monomer (D) further improves the dispersion stability and redispersibility of the dispersed resin particles. This is because the copolymerization component corresponding to the monomer (D) has a high affinity for the dispersion medium and is oriented on the particle surface portion, whereby the affinity for the dispersion medium of the particle itself with the dispersion medium is obtained. This is presumed to increase the properties and suppress the aggregation and precipitation of the particles. When the monomer (D) is used, the amount used is preferably 0.5 to 20% by mass, more preferably 1 to 15% by mass of all the monomers.
It is.

The monomers (A), (B) and (C) used in the present invention, and if necessary, the monomer (D)
Is copolymerized by a polymerization reaction to become a resin insoluble in a non-aqueous solvent.

Next, the dispersion stabilizing resin [P] used in the present invention will be described. In a non-aqueous solvent, the dispersion stabilizing resin [P] of the present invention, which is used for forming a solvent-insoluble polymer formed into a stable resin dispersion, is a polymer chain of an AB type block copolymer component. Is a star-type copolymer having at least three bonds to organic residues.

In the AB type block copolymer component,
One block (block A) that binds to organic residues is
Phosphono group, carboxyl group, sulfo group, hydroxyl group, formyl group, amino group, -P (= O) (OH) E ¹
A group [E ¹ represents an —E ² group or an —OE ² group, and E ² represents a hydrocarbon group], a —CONE ³ E ⁴ group, and a —SO ₂ NE ³ E
⁴ [E ³ and E ⁴ each independently represent a hydrogen atom or a hydrocarbon group], and a polymer component containing at least one polar group selected from cyclic acid anhydride-containing groups and / or It is constituted by containing at least one polymer component corresponding to the functional monomer (A).

Another block (block B) is constituted by containing at least one polymer component comprising a repeating unit represented by the above general formula (II).

Here, the order of the arrangement of the blocks A and B in the polymer chain is such that the organic backbone is located at one end of the block A opposite to the end where the polymer main chain of the block A is bonded to the block B. The resin [P] is schematically represented by the following formula (III).

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In the above formula (III), X represents an organic residue, [A] represents a block A, [B] represents a block B, and [A]-[B] represents a polymer chain. Also, such A
-The B-type block polymer chain is bonded to at least three or more organic residues. The upper limit is at most 15, usually about 10.

The mass composition ratio of block A to block B in the star copolymer is from 1/50/99 to 50, preferably from 5/40/95 to 60.

The specific polar group-containing polymer component contained in the block A is preferably 1 to 30 parts by mass, more preferably 1 to 15 parts by mass, per 100 parts by mass of the dispersion stabilizing resin [P]. is there. In the case where no specific polar group-containing polymer component is present in the block A, the polymer component corresponding to the functional monomer (A) is preferably 5 parts by mass in 100 parts by mass of the dispersion stabilizing resin [P]. It is 50 parts by mass, more preferably 10 to 40 parts by mass.

The general formula (I) contained in the block B
The polymer component represented by I) is preferably 50 to 99 parts by mass, more preferably 60 to 95 parts by mass, per 100 parts by mass of the dispersion stabilizing resin [P].

Next, block A of dispersion stabilizing resin [P]
Will be described in detail.

The block A is composed of a polymer component corresponding to the monofunctional monomer (A) and / or a polymer component containing the above-mentioned specific polar group. Monofunctional monomer (A)
As the polymer component corresponding to the above, the same as those described for the monomer (A) to be insolubilized can be mentioned.
Preferably, it is composed of the same monomer as the monofunctional monomer (A) which becomes the insoluble resin.

In a specific polar group, -P (＝ O) (OH) E
^{In one} group, E ¹ represents a —E ² group or a —OE ² group;
² represents a hydrocarbon group (preferably having 1 to 10 carbon atoms).
More preferably, the hydrocarbon group of E ² has 1 to 8 carbon atoms.
Aliphatic group which may be substituted (for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group,
Butenyl group, pentenyl group, hexenyl group, 2-chloroethyl group, 2-cyanoethyl group, cyclopentyl group, cyclohexyl group, benzyl group, phenethyl group, chlorobenzyl group, bromobenzyl group, etc.), and optionally substituted aromatic group (For example, phenyl group, tolyl group, xylyl group, mesityl group, chlorophenyl group, bromophenyl group, methoxyphenyl group, cyanophenyl group, etc.).

In the specific polar groups, in the groups -CONE ³ E ⁴ and -SO ₂ NE ³ E ⁴ , E ³ and E ⁴ are
Each independently represents a hydrogen atom or a hydrocarbon group (preferably a hydrocarbon group having 1 to 10 carbon atoms, more preferably a hydrocarbon group having 1 to 8 carbon atoms which may be substituted). Specific examples of the hydrocarbon group represented by E ³ and E ⁴ include the same as the hydrocarbon group represented by E ² .

The cyclic acid anhydride-containing group is a group containing at least one cyclic acid anhydride. Examples of the cyclic acid anhydride include aliphatic dicarboxylic anhydride and aromatic dicarboxylic anhydride. Things.

Examples of the aliphatic dicarboxylic anhydride include:
Succinic anhydride, glutaconic anhydride, maleic anhydride, cyclopentane-1,2-dicarboxylic anhydride, cyclohexane-1,2-dicarboxylic anhydride, 2,3-
Bicyclo [2, 2, 2] octane dicarboxylic anhydride and the like. These aliphatic dicarboxylic anhydrides include, for example, a chlorine atom, a halogen atom such as a bromine atom, a methyl group,
It may be substituted with an alkyl group such as an ethyl group, a butyl group, and a hexyl group.

Examples of the aromatic dicarboxylic anhydride include phthalic anhydride, naphthalene-dicarboxylic anhydride, pyridine-dicarboxylic anhydride, and thiophenedicarboxylic anhydride. Dicarboxylic anhydrides include, for example, chlorine atoms, halogen atoms such as bromine atoms, alkyl groups such as methyl group, ethyl group, propyl group, and butyl group, hydroxyl groups, cyano groups, nitro groups, alkoxycarbonyl groups (as alkoxy groups) , For example, a methoxy group, an ethoxy group, etc.).

In a more specific polar group, an amino group is represented by —N
H _2, represents a -NHE ⁵ or -NE ⁵ E ^6. E ⁵ and E ⁶ are
Represents a hydrocarbon group having 1 to 10, preferably 1 to 8 carbon atoms. More preferably represents a hydrocarbon group having 1 to 7 carbon atoms, specifically, the same hydrocarbon groups represented by E ² and the like.

The hydrocarbon groups of E ² , E ³ , E ⁴ , E ⁵ and E ⁶ are more preferably an alkyl group having 1 to 4 carbon atoms which may be substituted, a benzyl group which may be substituted, And a phenyl group which may be substituted.

The monomer corresponding to the polymer component containing the specific polar group may be any monofunctional monomer containing at least one specific polar group.
For example, it is described in “Polymer Data Handbook, Basic Edition”, edited by The Society of Polymer Science, Baifukan (1986). Specifically, acrylic acid, α- and / or β-substituted acrylic acid (for example, α-acetoxy form, α-acetoxymethyl form, α- (2-amino) ethyl form, α-chloro form, α-form)
Bromo form, α-fluoro form, α-tributylsilyl form,
α-cyano form, β-chloro form, β-bromo form, α-chloro-β-methoxy form, α, β-dichloro form, etc.), methacrylic acid, itaconic acid, itaconic acid half esters, itaconic acid semiamides , Crotonic acid, 2-alkenylcarboxylic acids (eg, 2-pentenoic acid, 2-methyl-2-hexenoic acid, 2-octenoic acid, 4-methyl-2-hexenoic acid,
4-ethyl-2-octenoic acid), maleic acid, maleic acid half esters, maleic acid half amides, vinylbenzene carboxylic acid, vinylbenzene sulfonic acid, vinyl sulfonic acid, vinyl phosphonic acid, vinyl group or allyl of dicarboxylic acids Half ester derivatives of these groups, ester derivatives of these carboxylic acids or sulfonic acids, and compounds containing the polar group in the substituents of the amide derivatives.

The following are specific examples of these compounds. However, in each of the following examples, e is-
_{H, -CH 3, -Cl, -Br} , -CN, -CH 2 COO
Represents CH ₃ , f represents —H or —CH ₃ , and n represents 2 to
Represents an integer of 10; m represents an integer of 1 to 10;
Represents an integer of from 4 to 4. X ₁ is -COOH, -O-P (=
_{O) (OH) 2, -SO} 3 H, -OH, -NR a R b, -C
HO or -OP (= O) (OH) _Ra is represented. Here, R _a and R _b represent an alkyl group having 1 to 4 carbon atoms. X ₂
Represents -COOH or -OH.

[0091]

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[0092]

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[0093]

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Next, the block B of the dispersion stabilizing resin [P] is used.
The repeating unit represented by the general formula (II) constituting the formula (II) will be described in detail.

In the general formula (II), X ¹ preferably represents -COO-, -OCO- or -O-.

Y ¹ preferably represents an alkyl group or an alkenyl group having 10 or more carbon atoms, which may be linear or branched. Specific examples include decyl, dodecyl, tridecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, docosyl, decenyl, dodecenyl, tridecenyl, hexadecenyl, octadecenyl, linolenyl, and the like. .

B ¹ and b ² may be the same or different from each other, and are preferably a hydrogen atom, a halogen atom (eg, a chlorine atom or a bromine atom), a cyano group, or an alkyl group having 1 to 3 carbon atoms (eg, Methyl group, ethyl group, propyl group, etc.), -COO-Z ¹ or -CH ₂ COO-Z ¹ [Z
¹ is a hydrogen atom or an optionally substituted carbon number of 1 to 22
(E.g., an alkyl group, an alkenyl group, an aralkyl group, an alicyclic group, an aryl group, etc.).

Specifically, Z ¹ is preferably a hydrogen atom or a hydrocarbon group which may be substituted, such as an alkyl group having 1 to 22 carbon atoms (eg, a methyl group, an ethyl group, a propyl group and a butyl group). Pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group, hexadecyl group, octadecyl group, eicosyl group, docosyl group, 2-chloroethyl group, 2-bromoethyl group, 2-cyanoethyl group, 2-
Methoxycarbonylethyl group, 2-methoxyethyl group,
3-bromopropyl group, etc., and an optionally substituted alkenyl group having 4 to 18 carbon atoms (eg, 2-methyl-1-propenyl group, 2-butenyl group, 2-pentenyl group, 3-methyl-2-pentenyl group) , A 1-pentenyl group, a 1-hexenyl group, a 2-hexenyl group, a 4-methyl-2-hexenyl group, a decenyl group, a dodecenyl group, a tridecenyl group, a hexadecenyl group, an octadecenyl group, a linolenyl group, and the like; Optionally substituted aralkyl groups (for example, benzyl group, phenethyl group, 3-phenylpropyl group, naphthylmethyl group, 2-naphthylethyl group,
Chlorobenzyl group, bromobenzyl group, methylbenzyl group, ethylbenzyl group, methoxybenzyl group, dimethylbenzyl group, dimethoxybenzyl group, etc.), having 5 to 8 carbon atoms
Which may be substituted (for example, cyclohexyl group, 2-cyclohexylethyl group, 2-cyclopentylethyl group, etc.) and an optionally substituted aromatic group having 6 to 12 carbon atoms (for example, phenyl group , Naphthyl, tolyl, xylyl, propylphenyl, butylphenyl, octylphenyl, dodecylphenyl, methoxyphenyl, ethoxyphenyl, butoxyphenyl, decyloxyphenyl, chlorophenyl, dichlorophenyl, bromo A phenyl group, a cyanophenyl group, an acetylphenyl group, a methoxycarbonylphenyl group, an ethoxycarbonylphenyl group, a butoxycarbonylphenyl group, an acetamidophenyl group, a propionamidophenyl group, and a dodecylylamidophenyl group.

In the block B of the dispersion stabilizing resin [P] used in the present invention, another repeating unit may be contained as a copolymer component together with the repeating unit represented by the general formula (II). The other copolymer component may be any compound as long as it is composed of a monomer copolymerizable with a monomer corresponding to the repeating unit of the general formula (II). However, it is used in an amount not exceeding 20 mass% in the block B at most. If it exceeds 20% by mass, the dispersibility of the dispersed resin particles may be deteriorated. It is preferable not to contain other monomers. In block B,
Two or more repeating units represented by the general formula (II) may be used in combination.

On the other hand, the organic residue to which at least three polymer chains are bonded is not particularly limited as long as it has a molecular weight of 1,000 or less. Examples include the following trivalent or higher valent hydrocarbon residues.

[0101]

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[Wherein r ^{3 to} r ⁶ each represent a hydrogen atom or a hydrocarbon group. However, at least one of r ³ and r ⁴
And at least one of r ⁵ and r ⁶ are each linked to a polymer chain. ]

These organic residues are composed of a single structure or an arbitrary combination thereof. In the case of a combination, -O-, -S-, -N (r ⁹ )-, -COO-,-
^{CON (r 9) -, -} SO 2 -, - SO 2 N (r 9) - ( wherein r ⁹ represents a hydrogen atom or a hydrocarbon group), - NH
COO-, -NHCONH-, oxygen atom, sulfur atom,
A heterocyclic ring containing a hetero atom such as a nitrogen atom (for example, a thiophene ring, a pyridine ring, a pyran ring, an imidazole ring, a benzimidazole ring, a furan ring, a piperidine ring, a pyrazine ring, a pyrrole ring, a piperazine ring, etc.); Combinations may be included.

Examples of organic residues to which other polymer chains are bonded include those composed of a combination of the following and the above-mentioned bonding unit. However, the organic residue of the present invention is not limited to these.

[0105]

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The star copolymer [P] of the present invention can be synthesized by using a conventionally known method for synthesizing a star polymer. For example, one of them is a polymerization reaction using a carbanion as an initiator. Specifically, M. Mor
ton, TE Helminiak et al, "J. Polym. Sci.", 57,
471 (1962), B. Gordon III, M, Blumenthal, JE Loft
us et al, "Polym. Bull.", 11, 349 (1984), RB Bates,
WA Beavers et al, "J. Org. Chem.", 44, 3800 (197
It can be synthesized according to the method described in 9).

However, when using this reaction, the specific polar group of the present invention is used as a protected functional group, polymerized, and then the protective group is eliminated. The protection of the specific polar group of the present invention with a protecting group and the removal of the protecting group (deprotection reaction) can be easily carried out by using a conventionally known method. For example, various descriptions are given in the above cited references. Further, Yoshio Iwakura and Keisuke Kurita, "Reactive Polymers", published by Kodansha (1977), TW Green "Pr
otective Groups in Organic Synthesis "(John Wiley &
Sons, 1981), JFW McOmic "Protective Groups
in Organic Chemistry "(Plenum Press, 1973) and the like.

As another method, a monomer which does not protect a specific polar group of the present invention is used, and a compound containing a dithiocarbamate group and / or a compound containing a xanthate group is used as an initiator and irradiated with light. It can also be synthesized by performing a polymerization reaction below. For example, Takayuki Otsu “Polymer”
37, 248 (1988), Shunichi Himori, Ryuichi Otsu "Polym. Rep. Ja
p. "37, 3508 (1988), JP-A-64-11, JP-A-64-26619, Nobuyuki Higashi, etc." Polymer Preprin
ts, Japan ", 36 (6), 1511 (1987), M. Niwa, N. Higash
i et al, "J. Macromol. Sci. Cem.", A24 (5), 567 (1
987) and the like.

The dispersion stabilizing resin [P] used in the present invention.
Is soluble in non-aqueous solvents. Specifically, toluene 10
It is sufficient that at least 5 parts by mass or more of the dispersion stabilizing resin [P] is dissolved at a temperature of 25 ° C. with respect to 0 parts by mass. The weight average molecular weight (Mw) of the dispersion stabilizing resin [P] of the present invention is 2 × 10 ⁴ to 1 × 10 ⁶ , preferably 3 × 10 ^{4 to} 5 × 10 ⁵ .

By using such a dispersion stabilizing resin [P] which is soluble in a non-aqueous solvent, the obtained dispersion has excellent dispersion stability and redispersibility. Further, the average particle diameter of the dispersed resin particles does not become large and the particle diameter distribution does not become broad.

That is, the dispersion stabilizing resin of the present invention [P]
Is a block B composed of a chain aliphatic group-containing polymer component having a high affinity for a non-aqueous solvent, as described above,
The polymer chain of the AB block combined with a block A composed of a polymer component having a low affinity for a non-aqueous solvent and having an affinity for a monomer (A) to be insolubilized is used as an organic residue. It is a star copolymer having at least three or more groups bonded to a group. As a result, the dispersed resin particles
The part is sufficiently adsorbed by physicochemical interaction during polymerization granulation, and the block B part having a large affinity for the non-aqueous dispersion medium is sufficiently solvated with the solvent, and the so-called,
Since there are three or more polymer chains serving as tail adsorptions, it is estimated that such effects are exhibited in order to sufficiently and efficiently exhibit the adsorption effect and the steric repulsion effect.

On the other hand, in the random copolymer of the polymer component used in the block A and the polymer component used in the block B, a polymer chain composed of a component which becomes a solvation component in the adsorbed portion is used. Since they are present randomly, the adsorption to the dispersed resin particles is not sufficient, and the adsorption pattern becomes loop-like, so that the steric repulsion effect is reduced and the effect as a dispersion stabilizing resin is inferior.

To produce the dispersed resin particles used in the present invention, generally, the dispersion stabilizing resin [P],
Monomer (A), monomer (B) and monomer (C) and, if necessary, monomer (D) in a non-aqueous solvent in benzoyl peroxide, azobisisobutyronitrile, butyl lithium Heating polymerization in the presence of a polymerization initiator such as Specifically, polymerization is carried out in a mixed solution of the dispersion stabilizing resin [P], the monomer (A), the monomer (B) and the monomer (C) and, if necessary, the monomer (D). A method of adding an initiator, a monomer (A) in a solution in which a dispersion stabilizing resin [P] is dissolved,
A method in which the monomer (B) and the monomer (C) and, if necessary, the monomer (D) are added dropwise together with a polymerization initiator, or a method in which a dispersion-stabilizing resin [P] is dissolved. A mixture of a half amount of the monomer (A) and the monomer (B) and a half amount of the monomer (A), a monomer (C), a monomer (D) if necessary, and a polymerization initiator. There is a method of dropping the mixture at the same time, and the mixture can be produced by any method.

The total amount of the monomers (A), (B) and (C) and, if necessary, the monomer (D) is preferably based on 100 parts by mass of the non-aqueous solvent. It is about 10 to 100 parts by mass, more preferably 10 to 80 parts by mass. The dispersion stabilizing resin [P] is 100% of all monomers used.
The amount is preferably 3 to 30 parts by mass, more preferably 5 to 20 parts by mass with respect to parts by mass. The amount of the polymerization initiator is suitably from 0.1 to 10% by mass of all the monomers. Further, the polymerization temperature is preferably about 40 to 180 ° C, more preferably 50 to 120 ° C. The reaction time is preferably 3 to 15 hours.

When the above-mentioned polar solvents such as alcohols, ketones, ethers and esters are used in combination in the non-aqueous solvent used in the reaction, or unreacted monomers of monomers to be polymerized and granulated remain. In this case, it is preferable to remove the solvent or the monomer by heating to a temperature higher than the boiling point of the solvent or distilling the solvent or the monomer under reduced pressure.

The non-aqueous dispersed resin particles produced according to the present invention as described above exist as fine particles having a uniform particle size distribution. Its average particle size is preferably 0.15
To 5 μm, more preferably 0.2 to 1.5 μm.
This particle size can be determined by CAPA-500 (manufactured by Horiba, Ltd.).

The weight average molecular weight (Mw) of the resin constituting the dispersed resin particles of the present invention is preferably from 5 × 10 ³ to 1 × 1.
0 is ^6, and more preferably from ^{8 × 10 3 ~5 × 10 5} . The thermophysical properties of the glass transition point are 0 ° C.
~ 80 ° C or a softening point of 35 ° C ~ 120 ° C is preferred,
More preferably, the glass transition point is 10C to 70C or the softening point is 38C to 90C.

The oil-based ink of the present invention is excellent in charge characteristics, dispersion stability, re-dispersibility, and storage stability of dispersed resin particles, and has good fast fixability after image formation, and is sufficient for printing. It maintains strength and shows high printing durability. That is, it shows very stable dispersibility, and particularly in a recording apparatus, has good dispersibility even when used repeatedly for a long time, and is easily redispersed.
No adhesion to any part of the device and no fouling is observed.

Furthermore, because of good fixability, if an ink image is formed and fixed by rapid processing such as heating, a strong film is easily formed on the surface of the lithographic printing original plate. Thereby, even in offset printing, printing of a large number of sheets (high printing durability) becomes possible. The oil-based ink of the present invention having the above effects is made possible by the non-aqueous latex provided by the present invention.

The dispersed resin particles in the oil-based ink used in the present invention exhibit positive charge. In order to adjust the charging characteristics of the oil-based ink, a technique of a wet developer for electrophotography can be appropriately used. Specifically, “Recent development and practical application of electrophotographic development systems and toner materials”, pp. 139-148, “Basic and Application of Electrophotographic Technology”, ed.
Page 05 (Corona Publishing, 1988), Yuji Harasaki "Electrophotography"
16 (No. 2), p. 44 (1977), etc.
This is done by using D) and other additives.

Examples of the charge control agent include metal soaps, organic phosphoric acids or salts thereof, organic sulfonic acids or salts thereof,
Amphoteric surfactant compounds are useful. For example, as metal soaps, fatty acids having 6 to 24 carbon atoms (for example, 2-ethylhexanoic acid, 2-ethylcaproic acid, lauric acid,
Metal salts such as palmitic acid, elaidic acid, linoleic acid, ricinoleic acid, oleic acid, stearic acid, enanthic acid, naphthenic acid, ethylenediaminetetraacetic acid), resin acids, dialkyl succinic acids, alkyl phthalic acids, and alkyl salicylic acids Na, K, Li, as metals of
B, Al, Ti, Ca, Pb, Mn, Co, Zn, M
g, Ce, Ag, Cd, Zr, Cu, Fe, Ba, etc.)
(For example, US Pat. Nos. 3,411,936 and 3,90
0,412, JP-B-49-27707, JP-A-Sho 51
-37651, 52-38937, and 52-10
7837 and 53-123138).

The organic phosphoric acid or salts thereof have 3 carbon atoms.
Mono-, di- or trialkylphosphoric acid or dialkyldithiophosphoric acid or the like comprising alkyl groups (for example, British Patent Nos. 1,411,739 and 1,276,3)
63, etc.). Examples of the organic sulfonic acids and salts thereof include long-chain aliphatic sulfonic acids, long-chain alkylbenzenesulfonic acids, dialkylsulfosuccinic acids, and metal salts thereof (for example, Japanese Patent Publication No. 47-128128).
And JP-A-53-123138 and JP-A-51-47437.
No. 50-79640, and No. 53-30340).

Examples of the amphoteric surfactant include phospholipids such as lecithin and kephalin (for example, JP-B-51-47046).
Metal complexes of β-diketones such as β-alanines containing an alkyl group having 8 or more carbon atoms (JP-A-50-17642 and JP-A-49-17774).
707) and copolymers containing a maleic acid half-amide component (for example, JP-B-6-19596 and JP-B6-1959).
No. 5, No. 6-23865, etc.).

These charge control agents (CD) can be used alone or in combination of two or more. The charge control agent is preferably used in an amount of 0.001 to 1.0 part by mass with respect to 1000 parts by mass of the dispersion medium as the carrier liquid.

The oil-based ink of the present invention contains dispersed resin particles composed of at least the monomer (A), the monomer (B) and the monomer (C), and preferably a charge control agent (CD). It is made.

The oil-based ink of the present invention was prepared using the above-mentioned WO 93/1.
When used in the method of forming an image by the electrostatic ink jet recording method disclosed in Japanese Patent Publication No. 1866, high-definition can be achieved without dropping of ink dots or deformation of the dot shape even at the ejection of minute dots and the high printing speed. The thickness of the printed dot image is 1 μm
The above is sufficiently maintained. This means that the positively charged resin particles in the oil-based ink are rapidly electrophoresed in the ink meniscus formed at the tip of the ejection electrode under an electrostatic field, and the particles are concentrated, resulting in an image signal. It is considered that the ejection is performed completely in response to the pulse voltage application.

Further, the oil-based ink of the present invention may be used after being stored for a long period of time or at high temperature and high humidity (for example, 40 ° C./80 RH).
%), Shows the same performance as a fresh product immediately after ink production even when ink-jet recording is performed after storage. This is considered to be due to the fact that the charging characteristics of the oil-based ink of the present invention, in particular, the charging characteristics of the positively charged particles are stably maintained, and that the aggregation and precipitation of the particles are prevented by maintaining the above-mentioned dispersion stability.

If desired, various additives may be added. The upper limit of the total amount of these additives is regulated by the electric resistance of the oil-based ink. That is, if the electric resistance of the ink from which the dispersed particles are removed is lower than 10 ⁹ Ω · cm, it becomes difficult to obtain a high-quality continuous tone image. Therefore, the amount of each additive must be controlled within this limit. Is desirable.

The oil-based ink of the present invention preferably contains a coloring material as a coloring component together with the above-described dispersed resin particles, for example, for plate inspection of a plate after plate making.

As the coloring material, any pigments and dyes conventionally used in oil-based ink compositions or liquid developers for electrophotography can be used.

As the pigments, those generally used in the technical field of printing can be used irrespective of inorganic pigments and organic pigments. Specifically, for example, carbon black, cadmium red, molybdenum red, chrome yellow, cadmium yellow, titanium yellow, chromium oxide, pyridian, cobalt green, ultramarine blue, Prussian blue, cobalt blue, azo pigment, phthalocyanine pigment , Quinacridone pigments, isoindolinone pigments, dioxazine pigments, threne pigments, perylene pigments, perinone pigments, thioindigo pigments, quinophthalone pigments, metal complex pigments, and other conventionally known pigments are particularly limited. It can be used without.

As the dye, azo dyes, metal complex dyes,
Naphthol dye, anthraquinone dye, indigo dye,
Oil-soluble dyes such as carbonium dyes, quinone imine dyes, xanthene dyes, cyanine dyes, quinoline dyes, nitro dyes, nitroso dyes, benzoquinone dyes, naphthoquinone dyes, phthalocyanine dyes and metal phthalocyanine dyes are preferred.

These pigments and dyes may be used alone or in an appropriate combination, but may be contained in the range of 0.05 to 20% by mass based on the whole ink. desirable.

These coloring materials may be dispersed in the non-aqueous solvent as the dispersed particles themselves in addition to the dispersed resin particles, or may be contained in the dispersed resin particles. One of the methods for adding the dye is to dye the dispersed resin material with an appropriate dye as described in JP-A-57-48738. Another method is disclosed in JP-A-53-5 / 78.
As disclosed in JP-A No. 4029 and the like, there is a method of chemically bonding a dispersing resin and a dye.
As described in, for example, No. 22555, there is a method of producing a dye-containing copolymer by using a monomer containing a dye in advance when producing by a polymerization granulation method.

Next, an image forming method by an electrostatic ink jet method using the oil-based ink of the present invention will be described. Here, a method of forming an image (plate making) using a printing original plate as an ink receiving material to form a printing plate will be described as an example.

The printing original plate is roughly classified into an original plate having a hydrophilic surface capable of lithographic printing and an original plate having a hydrophobic surface, and any of them can be used. The former printing original plate includes those in which the support itself has a hydrophilic surface and those in which a layer having a hydrophilic surface is provided on the support.

The water-resistant support having a lithographically printable hydrophilic surface may be any as long as it provides a hydrophilic surface suitable for lithographic printing. A support conventionally used for offset printing plates can be used as it is. it can. Specifically, bimetal plates such as aluminum plates, zinc plates, copper-aluminum plates, copper-stainless steel plates, chromium-copper plates, chromium-copper-aluminum plates, chromium-lead-iron plates, chromium-copper-stainless steel plates, etc. A substrate having a hydrophilic surface such as a trimetal plate is used. Its thickness is 0.1-3 mm, especially 0.1
１1 mm is preferred.

In the case of a support having an aluminum surface, a surface treatment such as graining treatment, immersion treatment in an aqueous solution of sodium silicate, potassium fluorozirconate, phosphate or the like, or anodic oxidation treatment is performed. Is preferred. Further, as described in U.S. Pat. No. 2,714,066, an aluminum plate grained and then immersed in an aqueous solution of sodium silicate is disclosed in JP-B-47-51.
As described in No. 25, a material obtained by subjecting an aluminum plate to anodizing treatment and then immersing the plate in an aqueous solution of an alkali metal silicate is also preferably used.

The anodizing treatment may be carried out, for example, by using an inorganic acid such as phosphoric acid, chromic acid, sulfur, boric acid, or an organic acid such as oxalic acid or sulfamic acid, or an aqueous or non-aqueous solution of a salt thereof, alone or in combination of two or more. It is carried out by flowing a current in the combined electrolyte using the aluminum plate as an anode. Also, silicate electrodeposition as described in U.S. Pat. No. 3,658,662 is effective. The treatment with polyvinyl sulfonic acid described in West German Patent Publication No. 1,621,478 is also suitable.

According to the combination of the ink and the recording method of the present invention, even when an image is formed on a metal surface, the ink is printed in a state where the particles in the ink are sufficiently concentrated so that the ink bleeds on the printed surface. No image bleeding occurs.

These surface treatments are performed not only to make the surface of the support hydrophilic, but also to improve the adhesion to the ink image provided thereon. A surface layer may be provided on the surface of the support in order to adjust the adhesion between the support and the ink image.

When a plastic sheet or paper is used as a support, a material provided with a surface layer having hydrophilicity is provided since the portion other than the ink image portion must be hydrophilic. Specifically, a known direct-drawing lithographic printing original plate or a plate material having a layer similar to the image receiving layer of the original plate can be used.

For example, as the image receiving layer, there is an image receiving layer composed mainly of a water-soluble binder, an inorganic pigment and a waterproofing agent. As the binder, PVA, modified PVA such as carboxy PVA, starch and its derivatives, CM
Water-soluble resins such as C, hydroxyethylcellulose, casein, gelatin, polyvinylpyrrolidone, vinyl acetate-crotonic acid copolymer, and styrene-maleic acid copolymer are used.

Examples of the water-resistant agent include glyoxal, melamine formaldehyde resin, initial condensate of aminoblast such as urea formaldehyde resin, modified polyamide resin such as methylolated polyamide resin, polyamide / polyamine / epichlorohydrin adduct, polyamide epichlorohydrin resin, modified Polyamide polyimide resin and the like can be mentioned. Examples of the inorganic pigment include kaolin, clay, calcium carbonate, silica, titanium oxide, zinc oxide, barium sulfate, and alumina, and silica is preferred.

In addition, a crosslinking agent such as ammonium chloride and a silane coupling agent can be used in the image receiving layer.

On the other hand, in a printing master having an image receiving layer composed of a hydrophobic surface, after forming an image, the non-image portion is rendered insensitive by a desensitizing treatment (that is, the non-image portion is treated with a hydrophilic surface repelling the printing ink). Conversion) to make a printing plate.

These printing masters include a printing master having an image receiving layer containing at least zinc oxide and a binder resin, and a hydrophobic binder formed by a desensitizing treatment (treatment liquid, light irradiation, heat treatment, etc.). A printing plate having an image receiving layer containing at least a binder resin which chemically converts the binder resin into a hydrophilic binder resin (for example, JP-A-1-226394,
Japanese Patent Publication No. 7-94191).

A lithographic printing plate precursor having an image receiving layer containing at least zinc oxide and a binder resin will be described.

The zinc oxide to be used is described in, for example, “Pigment Handbook” edited by Japan Pigment Technical Association, p.319, Seibundo Co., Ltd.
(1968), zinc oxide, zinc white,
Any of those commercially available as wet zinc white or activated zinc white may be used. That is, zinc oxide includes, as a dry method, a French method (indirect method), an American method (direct method) and a wet method, depending on the starting materials and the production method. For example, Shodo Chemical Co., Ltd., Sakai Chemical ( Co., Ltd.), Hakusui Chemical Co., Ltd., Honjo Chemical Co., Ltd., Toho Zinc Co., Ltd.,
Examples include those commercially available from various companies such as Mitsui Kinzoku Kogyo.

The content of zinc oxide in the image receiving layer was 7
It is preferably from 5 to 90% by mass, more preferably from 78 to 88% by mass. If the amount of zinc oxide is too small, hydrophilization of the surface of the image receiving layer by the desensitizing treatment becomes insufficient. On the other hand, if the amount is too large, the necessary strength of the image receiving layer cannot be secured, which is not preferable.

As described above, the binder resin provided to the image receiving layer is a hydrophobic resin constituting the image receiving layer together with zinc oxide, and has a molecular weight of a mass average molecular weight Mw.
Preferably from 10 ³ to 10 ⁶ , more preferably from 5 × 10 ³ to
It is 5 × 10 ⁵ . Further, the glass transition point of this resin is preferably 0 ° C to 120 ° C, more preferably 10 ° C to 90 ° C.
° C.

Specifically, styrene copolymers, methacrylate copolymers, acrylate copolymers, vinyl acetate copolymers, polyvinyl butyral, alkyd resins, epoxy resins, epoxy ester resins, polyester resins, polyurethane resins and the like can be mentioned. Can be These resins may be used alone or in combination of two or more.

In the image receiving layer, together with the above components,
Other components may be contained. Other components that may be included are other inorganic pigments of zinc oxide, such as kaolin, clay, calcium carbonate, barium carbonate, calcium sulfate, barium sulfate, magnesium carbonate, oxides Examples include titanium, silica, and alumina. When these other inorganic pigments are used in combination, it is desirable to use them in a range not exceeding 20 parts by mass with respect to 100 parts by mass of zinc oxide.

Further, in order to improve the desensitization of the image receiving layer, Japanese Patent Application Laid-Open Nos. 4-201387 and 4-223196.
No. 4-319494, No. 5-58071, No. 4
Resin particles such as acrylic acid resin particles containing a specific functional group described in JP-A-353495 and JP-A-5-119545 may also be contained. These resin particles are usually spherical, and preferably have an average particle size of 0.1 to 2 μm. The content of the resin particles is preferably 20% by mass or less of the components of the image receiving layer.

By using these other inorganic pigments or resin particles, desensitization (hydrophilicity) of the non-image area due to the desensitization treatment is sufficiently performed, background smear of printed matter is suppressed, and image area is reduced. It is sufficiently adhered to the image receiving layer, and sufficient printing durability can be obtained without causing image defects even when the number of printed sheets increases.

In addition, a crosslinking agent may be added to the image receiving layer in order to further improve the film strength.

The binder resin is preferably cured with light and / or heat after the application of the image receiving layer composition. In order to carry out thermosetting, for example, the drying conditions are made stricter than the drying conditions at the time of preparing the conventional image receiving layer. For example, it is preferable to set the drying conditions to a high temperature and / or a long time, or to further heat after drying the coating solvent.
For example, the treatment is performed at 60 ° C to 150 ° C for 5 to 120 minutes. When a reaction accelerator is used in combination, the treatment can be performed under milder conditions.

As a method of curing by irradiation with light, a specific functional group in the resin may be irradiated with light with a chemically active light beam. The chemical actinic ray may be any of visible ray, ultraviolet ray, far ultraviolet ray, electron beam, X-ray, γ ray, α ray and the like, but is preferably ultraviolet ray, more preferably a ray having a wavelength of 310 nm to 500 nm. . Generally, a low-pressure, high-pressure or ultra-high-pressure mercury lamp, a halogen lamp, or the like is used. The light irradiation treatment can be sufficiently carried out by irradiation from a distance of 5 cm to 50 cm for 10 seconds to 10 minutes.

The thickness of the image receiving layer is from 3 to 3 in terms of the coating amount of the image receiving layer composition per m ^{2 of} the printing plate precursor (after drying).
It is preferred to be about 30 g. The image receiving layer is usually 3 to 50 vol%, preferably 10 to 40 vol%.
It is preferable to have a porosity of the order.

The image receiving layer is provided on a water-resistant support. As the water-resistant support, paper, a plastic film or a paper or a plastic film laminated with a metal foil, which has been subjected to a water-resistant treatment can be used.

The support preferably has a highly smooth surface. That is, the smoothness of the surface on the side adjacent to the image receiving layer is adjusted to a Beck smoothness of 300 (sec / 10 ml) or more, preferably 900 to 3000 (sec / 10 ml), and more preferably. 1000-300
It is preferably 0 (second / 10 ml).

By regulating the smoothness of the surface of the support on the side adjacent to the image receiving layer to a Beck smoothness of 300 (sec / 10 ml) or more, the image reproducibility and printing durability can be further improved. . Such an improvement effect is obtained even if the smoothness of the image receiving layer surface itself is the same, and the adhesion between the image portion and the image receiving layer is improved by increasing the smoothness of the support surface. it is conceivable that.

Here, the Beck smoothness can be measured by a Beck smoothness tester. A Beck smoothness tester presses a test piece at a constant pressure (1 kg / cm ² ) on a highly smooth finished circular glass plate with a hole in the center, and a fixed amount (10 ml) under reduced pressure. It measures the time required for air to pass between the glass surface and the specimen.

The highly smooth surface of such a water-resistant support means a surface to which an image receiving layer is directly applied. For example, when an under layer or an overcoat layer described later is provided on the support, , The surface of the underlayer or overcoat layer. As a result, the image receiving layer whose surface condition has been adjusted as described above is sufficiently retained without receiving the unevenness of the surface of the support, and the image quality can be further improved.

As a method of setting the smoothness within the above range, various conventionally known methods can be used. Specifically, by a method of melting and bonding the substrate surface with a resin, a method such as a calendar strengthening method using a highly smooth heat roller,
A method of adjusting the Beck smoothness of the surface of the support can be used.

As a method for melting and bonding the above resins, it is preferable that the resin is coated by an extrusion lamination method. By coating by this extrusion lamination method, a support having a desired smoothness can be produced. The extrusion laminating method is a method in which a resin is melted, formed into a film, immediately pressure-bonded to base paper, and then cooled and laminated, and various apparatuses are known. The thickness of the resin layer laminated in this manner is 10 μm from the viewpoint of production stability.
That is all. Preferably it is 10 μm to 30 μm.

Further, as described above, an under layer is provided between the support and the image receiving layer for the purpose of improving water resistance and interlayer adhesion, and a curl is provided on the surface of the support opposite to the image receiving layer to prevent curling. A back coat layer (back layer) can be provided, and the back coat layer has a smoothness of 150 to
It is preferably in the range of 700 (sec / 10 ml).
Accordingly, when the printing plate is supplied to the offset printing press, the printing plate is accurately set on the printing press without causing displacement or slippage.

When the smoothness of the underlayer and the backcoat layer of such a support are individually adjusted, for example, calendering is performed once after the underlayer is formed, and calendering is performed again after the backcoat layer is formed. In addition, the process of calendar processing is performed multiple times,
It is desirable to control the smoothness by a combination of adjusting the composition of the under layer and the back coat layer, for example, the proportion and particle size of the pigment, and adjusting the calendering conditions as described below.

Examples of the substrate used for the printing plate precursor include substrates such as wood pulp paper, synthetic pulp paper, mixed paper of wood pulp and synthetic pulp, non-woven fabric, plastic film, cloth, metal sheet, and composite sheet materials thereof. Can be used as it is. Also, to obtain a specific smoothness,
And in order to adjust the water resistance and other properties, the above substrate is impregnated with a coating material composed of a hydrophobic resin, a water-dispersible or water-soluble resin, a pigment, or the like used for an under layer or a back coat layer described below. You may.

In order to satisfy the printing suitability required for the lithographic printing original plate, for example, recording characteristics, water resistance, durability and the like, and to adjust the desired smoothness as described above, an under layer and a back coat layer are formed on the substrate. It is preferable to use a support provided with. Such an under layer and a back coat layer are formed by applying a coating solution containing a resin, a pigment, and the like on a support, drying and laminating the coating solution.
Various resins are appropriately selected and used as the resin used here. Specifically, examples of the hydrophobic resin include an acrylic resin, a vinyl chloride resin, a styrene resin, a urethane resin, a vinylidene chloride resin, and a vinyl acetate resin.Examples of the hydrophilic resin include polyvinyl resin. Alcohol resins, cellulose derivatives, starch and derivatives thereof, polyacrylamide resins, styrene-maleic anhydride copolymers and the like can be mentioned.

Examples of the pigment include clay, kaolin, talc, diatomaceous earth, calcium carbonate, aluminum hydroxide, magnesium hydroxide, titanium oxide, mica and the like. These pigments are used to achieve the desired smoothness.
It is preferable to appropriately select and use the particle size. For example, since a relatively high degree of smoothness is required in the under layer, a small particle size or a large particle is cut to specifically 8 μm or less, preferably Preferably, a pigment having a particle size of about 0.5 to 5 μm is used. Further, since a lower smoothness is required in the back coat layer as compared with the under layer, a larger particle size, specifically, 0.5 to 10
A pigment having a particle size of about μm is preferably used. The pigment as described above is preferably used in a ratio of 80 to 150 parts by mass in the under layer and 80 to 200 parts by mass in the back coat layer, based on 100 parts by mass of the resin. In order to obtain excellent water resistance, it is effective for the under layer and the back coat layer to contain a water-resistant agent such as a melamine resin or a polyamide epichlorohydrin resin. The particle size can be measured by a scanning electron microscope (SEM) photograph. When the particles are not spherical, the diameter is obtained by converting the projected area into a circle.

In order to prepare a lithographic printing plate precursor, a solution containing an underlayer component is coated on one side of the support, if necessary, and dried to form an underlayer. If necessary, a backing layer is formed on the other side. After forming a back coat layer by applying and drying a solution containing a coating layer component, a coating solution containing an image receiving layer component may be applied and dried to form an image receiving layer. Note that the image-receiving layer, the under layer, the coating amount of the backcoat layer are each 1 to 30 g / m ^2, in particular 6~20g / m ² is suitable. Preferably, the water-resistant support provided with an under layer or a back coat layer has a thickness of 90 to 1
It is in the range of 30 μm, more preferably in the range of 100 to 120 μm.

Next, a method of forming an image on the lithographic printing original plate (hereinafter also referred to as “master”) will be described. FIG. 1 shows an example of an apparatus system for performing such a method. The apparatus system shown in FIG. 1 has an ink jet recording apparatus 1 using oil-based ink.

As shown in FIG. 1, first, pattern information of an image (figure or text) to be formed on the master 2 is transmitted from an information source such as a computer 3 through a transmission means such as a bus 4 to an oil-based ink. Is supplied to the ink jet recording apparatus 1 that uses. The ink jet recording head 10 of the recording apparatus 1 stores oil-based ink therein, and when the master 2 passes through the recording apparatus 1, ejects minute droplets of the ink to the master 2 according to the information. Thereby, ink adheres to the master 2 in the pattern. Thus, an image is formed on the master 2 to obtain a plate-making master (plate-making printing original plate).

FIGS. 2 and 3 show examples of the configuration of an ink jet recording apparatus as in the apparatus system of FIG. FIG. 2 is a view showing a part of the head of such an ink jet recording apparatus, and FIG. 3 is a view for further explaining the structure thereof.

As shown in FIG. 2, the ink jet recording head 10 provided in the ink jet recording apparatus comprises a head main body 14 made of an insulating material such as plastic or ceramic, and meniscus regulating plates 15 and 16. In the figure, reference numeral 17 denotes an ejection electrode for applying a voltage to perform ejection. Fig. 3 with the restriction plate removed from the head
The head body will be described in detail below.

The head main body 14 is provided with a plurality of ink grooves 18 for circulating ink, perpendicular to the edge of the head main body, and an ejection electrode 17 is provided therein.
Two adjacent ink grooves form one cell, and ejection parts 20, 20 'are provided at the end of the partition wall 19 at the center. In the ejection portions 20 and 20 ′, the partition walls are thinner than the other partition portions 25 and are sharpened. The tip of the discharge unit may be slightly chamfered as in 20 '. Although only two cells are shown in the figure, the cells are separated by a partition 21 and the tip 22 thereof is formed by a discharge unit 20.
It is chamfered so as to be retracted from 20 '.

With respect to this head, ink is supplied from an I direction through an ink groove by an ink supply means (not shown), and ink is supplied to a discharge section. Excess ink is collected in the O direction by an ink collecting means (not shown).
As a result, fresh ink is always supplied to the ejection unit. In this state, by applying a voltage to the discharge electrode against a counter electrode (not shown) which is provided in a form opposing the discharge unit and holds the printing original on the surface, ink is discharged from the discharge unit, and An image is formed on the original.

As described above, on the lithographic printing original plate,
An image is formed by an ink-jet method using oil-based ink, and plate making is performed. When the lithographic printing plate precursor used comprises a hydrophilic surface layer, it is used as it is as a printing plate for offset printing.

On the other hand, in the case of a lithographic printing original plate accompanied with desensitization, a printing plate is prepared by desensitizing non-image areas by surface treatment with a desensitizing solution. Desensitization of zinc oxide
Conventionally, as this type of desensitizing treatment solution, a cyanide-containing treatment solution containing ferrocyanide salt, ferricyan salt as a main component, an ammine cobalt complex, phytic acid and derivatives thereof, and a cyan-free treatment containing a guanidine derivative as a main component Liquids, treatment liquids containing an inorganic or organic acid which forms a chelate with zinc ions as a main component, treatment liquids containing a water-soluble polymer, and the like are known.

For example, as a cyanide-containing treatment solution,
JP-B-44-9045, JP-B-46-39403, JP-A-52-76101, JP-A-57-107889, and JP-A-57-107889.
4-117201 and the like. Phytic acid-based compound-containing treatment solutions are disclosed in JP-A-53-83.
No. 807, No. 53-83805, No. 53-10210
No. 2, No. 53-109701, No. 53-127003
And Nos. 54-2803 and 54-44901.

Examples of the treating solution containing a metal complex compound such as a cobalt complex include JP-A-53-104301 and JP-A-53-104301.
No. 140103, No. 54-18304, Tokuhei 43-
No. 28404. As an inorganic or organic acid-containing treatment solution, JP-B-39-13702,
Nos. 40-10308, 43-28408, 40
-26124 and JP-A-51-118501.

Examples of the guanidine compound-containing treating solution include those described in JP-A-56-11695. As a processing solution containing a water-soluble polymer, Japanese Patent Application Laid-Open
-126302, 52-134501, 53-
49506, 53-59022, 53-104
No. 302, JP-B-38-9665 and 39-2226
3, No. 40-763, No. 40-2202, and JP-A-49-36402.

In any of the above desensitizing treatments,
Zinc oxide in the surface layer ionizes into zinc ions,
It is believed that these ions cause a chelation reaction with a compound forming a chelate in the desensitizing solution to form a zinc chelate, which is deposited in the surface layer and hydrophilized.

The desensitizing treatment is usually performed at room temperature (15 ° C. to 35 ° C.).
) For about 2 to 60 seconds. Using this printing plate, several thousand sheets of offset printing are possible using dampening water.

[0186]

EXAMPLES The present invention will be described in more detail below with reference to Production Examples and Examples of dispersion stabilizing resins and resin particles (latex particles) used in the present invention, but the present invention is not limited to these. is not.

Synthesis Example 1 of Dispersion Stabilizing Resin [P] Resin [P-1] 50 g of methyl methacrylate, 50 of methyl acrylate
g, a mixture of 7.8 g of an initiator [I-1] having the following structure and 100 g of tetrahydrofuran at a temperature of 50 under a nitrogen stream.
Warmed to ° C. The solution was added to the solution with a 400 W high-pressure mercury lamp.
Light irradiation photopolymerization was performed for 8 hours through a glass filter from a distance of cm. The polymer was reprecipitated in 1 liter of methanol, and the precipitate was collected and dried.

[0188]

Embedded image

Next, a mixed solution of 30 g of the above polymer, 70 g of stearyl methacrylate and 100 g of tetrahydrofuran was heated again to a temperature of 50 ° C. under a nitrogen stream.
Next, after performing light irradiation for 16 hours in the same manner as above,
The obtained reaction product was reprecipitated in 1.5 liters of methanol, and the precipitate was collected and dried. The yield was 80 g and the mass average molecular weight [Mw: Mw was determined by the GPC method in terms of polystyrene (GPC: size exclusion chromatography). Value by graphy)
Gave a polymer [P-1] of 6 × 10 ^{4 having} the following structure.

[0190]

Embedded image

Synthesis Examples 2 to 14 of Dispersion Stabilizing Resin [P]:
Resins [P-2] to [P-14] In Synthesis Example 1 of dispersion stabilizing resin, initiator [I-1]
In place of the initiator [I-2 to 14] described in Table A below.
A polymer was synthesized in the same manner as in Synthesis Example 1 except that 0.011 mol was used. The Mw of each polymer obtained was 4 × 10 ⁴
６6 × 10 ⁴ .

[0192]

[Table 1]

[0193]

[Table 2]

[0194]

[Table 3]

[0195]

[Table 4]

Synthesis Examples 15 to 2 of Dispersion Stabilizing Resin [P]
8: Resins [P-15] to [P-28] Each monomer (mass ratio) corresponding to the polymer component of block A shown in Table B below, and 0.1 to all monomers used. A mixture of 01 mol of the initiator [I-7] and 100 g of tetrahydrofuran was heated to a temperature of 50 ° C. under a nitrogen stream. This solution was irradiated with light for 12 hours in the same manner as in Synthesis Example 1 to perform a polymerization reaction.

Next, each of the obtained polymers was subjected to a predetermined amount (x: as solid content) shown in Table-B and to each monomer (corresponding to the polymer component of block B shown in Table-B below). Mass ratio) using a predetermined amount (y: solid content amount) shown in Table-B, and adding a mixed solution containing tetrahydrofuran so that the concentration of all the compounds becomes 60% by mass. Heated. Next, after performing light irradiation for 16 hours in the same manner as described above, the obtained reaction product was reprecipitated in 1.5 liters of methanol, and the precipitate was collected and dried. Polymers having Mw of 3 × 10 ^{4 to} 6 × 10 ⁴ were obtained in a yield of 60 to 80 g.

[0198]

[Table 5]

[0199]

[Table 6]

[0200]

[Table 7]

[0201]

[Table 8]

Production Example 1 of Resin Particles (L) 1: Resin Particles (L-1) 15 g of dispersion stabilizing resin [P-1], 90 g of vinyl acetate,
2- (N, N-diethylamino) ethyl crotonate 5
g, a mixed solution of 5 g of 4-sulfobutyl crotonate, 43 g of ethanol and 242 g of Isopar H were heated to a temperature of 70 ° C. while stirring under a nitrogen stream. 2,2'-azobis (isovaleronitrile) as a polymerization initiator
(Abbreviation AIVN) was added and reacted for 3 hours. Further, 0.8 g of an initiator 2,2'-azobisisobutyronitrile (abbreviation: AIBN) was added, and
The mixture was heated to a temperature of 80 ° C. and reacted for 4 hours. Continue to temperature 1
The mixture was heated to 00 ° C. and stirred for 2 hours to distill off unreacted monomers and ethanol. After cooling, the mixture was passed through a nylon cloth of 200 mesh, and the obtained white dispersion was a latex having a conversion of 95% and an average particle size of 0.48 μm. Particle size is CAPA-
500 (manufactured by Horiba, Ltd.) (the same applies hereinafter).

A part of the white dispersion was centrifuged (rotation
Number 1 × 10^Fourr.p.m., rotation time 1 hour).
The collected resin particles are collected and dried, and the mass average
The molecular weight (Mw) and the glass transition point (Tg) were measured. mass
The average molecular weight (Mw) is calculated by GPC based on polystyrene.
It is a value by the method (the same applies hereinafter). Mw is 1 × 10 ^Five,
Tg was 40 ° C.

Production Example 2 of Resin Particles (L): Resin Particles (L-2) 10 g of Dispersion Stabilizing Resin [P-15] and Isopar G2
70 g of the mixture was heated to a temperature of 70 ° C. while stirring under a stream of nitrogen. To this, 15 g of methyl methacrylate, 30 g of methyl acrylate, 2- (N, N-dimethylamino)
6 g of ethyl methacrylate, 3 g of octadecyl methacrylate and A.I. I. V. N. 1.5 g of the mixture and 15 g of methyl acrylate, 24 of methyl acrylate
g, a mixture of 6 g of 3-sulfopropyl methacrylate and 20 g of ethanol were simultaneously added dropwise in one hour, and the mixture was stirred for 2 hours. Next, A. I. V. N. Was added, and the mixture was heated to a temperature of 75 ° C. and stirred for 3 hours. I. B. N. Was added, and the mixture was heated to a temperature of 80 ° C. and stirred for 3 hours. Then raise the temperature to 100 ° C,
The mixture was stirred at a reduced pressure of 200 mmHg for 2 hours to distill off ethanol and unreacted monomers. After cooling, the mixture was passed through a 200-mesh nylon cloth, and the resulting white dispersion was a latex having a conversion of 99% and an average particle size of 0.45 μm. The Mw of the resin particles was 2 × 10 ⁵ , and the Tg was 42 ° C.

Production Examples 3 to 14 of Resin Particles (L): Resin Particles (L-3) to (L-14) Resin for stabilizing dispersion [P-15] used in Production Example 2 of resin particles (L) Was replaced with each of the compounds shown in Table-G below, and resin particles were produced in the same manner as in Production Example 2 above. The polymerization rate of each of the obtained resin particles is 98.
１００100%, the average particle size was in the range of 0.40 to 0.45 μm, and the monodispersity was good. M for each resin particle
w was in the range of 1 × 10 ^{5 to} 3 × 10 ⁵ , and Tg was in the range of 37 to 45 ° C.

[0206]

[Table 9]

Production Example 15 of Resin Particles (L): Resin Particles (L-15) 10 g of dispersion stabilizing resin [P-7] and Isopar H26
0 g of the mixture was heated to a temperature of 70 ° C. while stirring under a nitrogen stream. 20 g of methyl methacrylate, 30 g of ethyl acrylate, 8 g of 2- (N, N-diethylamino) ethyl methacrylate, 2 g of 2,3-dioctanoyloxypropyl methacrylate, and I. V. N. And a mixture of 15 g of methyl methacrylate, 20 g of methyl acrylate, 5 g of 4-sulfobutyl acrylate and 30 g of ethanol were simultaneously added dropwise in 1 hour, and the mixture was stirred for 2 hours. Next, A.
I. V. N. And heated to a temperature of 75 ° C.
Stir for an hour. I. B. N. Was added, and the mixture was heated to a temperature of 80 ° C. and stirred for 3 hours. Then raise the temperature to 10
The temperature was raised to 0 ° C., and the mixture was stirred under a reduced pressure of 200 mmHg for 2 hours to distill off ethanol and unreacted monomers. After cooling, the mixture was passed through a 200-mesh nylon cloth, and the resulting white dispersion was a latex having a conversion of 99% and an average particle size of 0.50 μm. The Mw of the resin particles was 1 × 10 ⁵ , and the Tg was 40 ° C.

Production Examples 16 to 25 of Resin Particles (L): Resin Particles (L-16) to (L-25) In Production Example 15 of resin particles (L), dispersion stabilizing resins [P-7] and 2 Produced in the same manner as in Production Example 15 except that each compound shown in Table-H below was used instead of 2,3-dioctanoyloxypropyl methacrylate. The polymerization rate of each of the obtained particles is 97 to 99%, and the average particle size is 0.3.
The monodispersity was good within the range of 5 to 0.45 μm. The Mw of the resin particles is 9 × 10 ⁴ to 4 × 10 ⁵ , T
g ranged from 39 to 43 ° C.

[0209]

[Table 10]

Production Examples 26 to 30 of Resin Particles (L): Resin Particles (L-26) to (L-30) In Production Example 15 of resin particles (L), 10 g of resin [P-7] for dispersion stabilization was prepared. Instead, 10 g of each resin in Table I below,
Instead of 8 g of 2- (N, N-diethylamino) ethyl methacrylate, 0.027 of the monomer (B) in Table I below was used.
Each particle was produced in the same manner as in Production Example 15 except that 0.02 mol of the monomer (C) in Table I below was used instead of the mol and 5 g of 4-sulfobutyl acrylate.
The average particle diameter of each of the obtained particles was latex in the range of 0.35 to 0.45 μm. Mw for resin particles is 9 × 1
0 ⁴ ~2 × 10 ^5, Tg ranged from 40-48 ° C..

[0211]

[Table 11]

Production Example 1 of Comparative Resin Particles Comparative Resin Resin Particles (LR-1) In the production example 1 of resin particles (L), 98 g of vinyl acetate and 2 g of octadecyl methacrylate were used as monomers to be polymerized. In the same manner as in Production Example 1, resin particles were produced. The obtained white dispersion had a conversion of 96% and an average particle size of 0.35 μm. Mw of resin particles is 2 × 10
^5. Tg was 37 ° C.

Production Example 2 of Comparative Resin Particles: Comparative Resin Particles (LR-2) In Production Example 1 of resin particles (L), 95 g of vinyl acetate and 5 g of 4-sulfobutyl crotonate were used as monomers to be polymerized. Resin particles were produced in the same manner as in Production Example 1 except for using. The resulting white dispersion had a conversion of 95% and an average particle size of 0.40 μm. Mw for resin particles is 9 × 1
0 ^4, Tg was 40 ° C..

Example 1 <Preparation of a lithographic printing plate precursor> A composition having the following contents was added together with glass beads to a paint shaker (Toyo Seiki Co., Ltd.)
And dispersed for 60 minutes, and then the glass beads were separated by filtration to obtain a dispersion.

・ Gelatin 8 g ・ Alkoxysilane-modified polyvinyl alcohol R1130 (manufactured by Kuraray Co., Ltd.) 4 g ・ Silica: Thylysia 310 (manufactured by Fuji Silysia Chemical Ltd.) 8 g ・ Colloidal silica 20% solution: Snowtec C 38 g (Nissan Chemical Industrial Co., Ltd.)-Fluorinated alkyl ester FC430 (manufactured by 3M) 0.8 g-Hardening compound 0.24 g CH ₂ = CHSO ₂ CH ₂ CONH (CH ₂ ) ₃ NHCOCH ₂ SO ₂ CH = CH _2. 54 g of water

An ELP-2X master known as an electrophotographic lithographic printing plate precursor (Fuji Photo Film Co., Ltd.)
The above composition was coated on the support using a wire bar and dried at 100 ° C. for 10 minutes to form an image receiving layer having a coating amount of 8 g / m ^2. I got The surface smoothness of the obtained image receiving layer was measured using a Beck smoothness tester (manufactured by Kumagai Riko Co., Ltd.) with an air capacity of 10 ml.
When the smoothness (sec / 10 ml) was measured under the conditions described above, it was 250 (sec / 10 ml). Further, 2 μl of distilled water was placed on the surface of the image receiving layer, and the surface contact angle (degree) after 30 seconds was measured using a surface contact meter CA-D (Kyowa Interface Science Co., Ltd.)
The contact angle with water on the surface of the image receiving layer was 0 degree.

<Preparation of Oil Ink (IK-1)> 10 g of polydodecyl methacrylate and 10 g of alkali blue
g and Shellsol 71 together with 30 g glass beads in a paint shaker (manufactured by Toyo Seiki Co., Ltd.)
The mixture was dispersed for a time, and the glass beads were separated by filtration to obtain a fine blue dispersion. 50 g (as a solid content) of the resin particles (L-1) produced in Production Example 1 of the above resin particles (L), 18 g of the above-mentioned alkali blue dispersion, and 0.15 g of cobalt octenoate are diluted to 1 liter of Isopar E. Thus, a blue oil-based ink was prepared.

Comparative Example A The procedure of Example 1 was repeated, except that the oil-based ink (IKR-1) was replaced with the oil-based ink (IKR-1) described below. <Preparation of Comparative Oil-Based Ink (IKR-1)> In the preparation of the oil-based ink (IK-1), except that the comparative resin particles (LR-1) were used instead of the resin particles (L-1), inks were used. It was prepared in the same manner as (IK-1).

Comparative Example B The procedure of Example 1 was repeated, except that the oil-based ink (IKR-2) having the following content was used in place of the oil-based ink (IK-1). <Preparation of Comparative Oil-Based Ink (IKR-2)> In the preparation of the oil-based ink (IK-1), except that the comparative resin particles (LR-2) were used in place of the resin particles (L-1), inks were used. It was prepared in the same manner as (IK-1).

The charging characteristics, ejection properties,
The shape of printed dots, image reproducibility, printing durability, etc. were examined, and the results are shown in Table J.

[0221]

[Table 12]

The evaluation items described in Table J were performed in accordance with the following contents. Note 1) Charging characteristics-AC electric conductivity AC electric conductivity (pS / cm) was measured as the amount of charge of the ink. The AC electrical conductivity of the ink was measured with an LCR meter (AG-4311, manufactured by Ando Electric Co., Ltd.). At the time of measurement, a liquid electrode placed in a self-made aluminum shield box was filled with 2.3 ml of the ink to be measured via a test lead (AG-4912, manufactured by Ando Electric Co., Ltd.) using an LCR meter. (LP- manufactured by Kawaguchi Electric Co., Ltd.)
05, electrode constant 198), conductance was measured at an applied voltage of 5 V and a measurement frequency of 1 kHz, and the value was converted to an electric conductivity by dividing the value by the electrode constant. In the measurement, the measurement parameters of the LCR meter were set to capacitance, and the circuit mode was set to parallel mode.

Particle Charge Ratio Indicates the ratio of the amount of charge of the dispersed particles in the ink.

[0224]

(Equation 1)

Here, the charge amount of the supernatant is determined by measuring the AC electrical conductivity of the transparent liquid obtained by sedimenting the ink by centrifugation (conditions: 1 × 10 ⁴ rpm, 1 hour). Represent.

Further, the conditions I and II show changes in the aging condition after the ink production, and the condition I means that the ink obtained by blending all the components was allowed to stand naturally for one week (normal temperature, normal humidity). )
(Fresh product), while condition II is
The fresh product was stored under high-temperature and high-humidity (40 ° C., 85% RH) conditions for 2 weeks and was forcibly aged (aged product).

Note 2) Dischargeability Dischargeability was measured by an apparatus using an injection needle as shown in FIG. The injection needle is made of stainless steel and has an inner diameter of 36.
0 μm, an outer diameter of 615 μm, a cutting angle at the tip of 19 °, a radius of curvature of 13 μm, and an ink tank 36 at the tip of the needle.
Is always supplied from the inside of the needle by the liquid sending pump 35, and the excess ink is naturally transmitted to the needle surface and collected in the waste liquid tank 37. The ink flow rate at this time is 0.75
ml / min. The injection needle is arranged at a distance of 300 μm from the surface of the plate material as the recording medium 32 mounted on the drum-shaped counter electrode 31, and a power supply 33 applies a pulse voltage of 800 V and a discharge voltage of 100 μSec as a discharge voltage to a bias voltage of 700 V. Printing was performed by superimposing and applying a frequency of 0.5 kHz. The polarity of the bias and the pulse voltage was determined so that the ink was repelled from the injection needle. The ejection rate was calculated from the number of dots actually printed with respect to the number of applied pulses (%). Conditions I and II are the same as in Note 1).

Note 3) Shape and thickness of print dot In the above evaluation items of dischargeability, the film thickness of the print dot of the sample subjected to the discharge test was measured from a scanning electron microscope (SEM) photograph. The larger the film thickness is, the more concentrated the particles in the ink are ejected.

Shape Similarly, the presence or absence of dot bleeding, distortion, and the like was examined by using the above sample and observing photographs with an optical microscope and an SEM.

Note 4) Image reproducibility Using the lithographic printing plate prepared as described above, a Servo Plotter DA8400 manufactured by Graphtec Co., Ltd., capable of drawing a PC output, was modified and shown in FIG. 2 in the Ben plotter section. The ink ejection head was mounted, and printing was performed on the lithographic printing original plate placed on the counter electrode spaced at a distance of 500 μm using the above oil-based ink to make a plate. At this time, printing was performed at a bias voltage of 650 V, an ejection voltage of 700 V,
The test was performed under the condition that a pulse voltage having a width of 0 μsec and a frequency of 2.0 kHz were used. Next, RICOFUUSER model 5
Using 92 (manufactured by Ricoh Co., Ltd.), the surface temperature of the ink image was adjusted to 95 ° C. and heated for 20 seconds to sufficiently fix the image area. A copy image of the obtained plate (ie, printing plate) was visually observed at a magnification of 200 times with an optical microscope.

Note 5) Printing durability Using a printing plate obtained according to the method of Note 4), using a solution obtained by diluting SLM-OD (manufactured by Mitsubishi Paper Mills) 30 times with water as immersion water. Oliver 94 type (manufactured by Sakurai Seisakusho Co., Ltd.) was used as a printing machine, and printing was performed using black ink for offset printing. The number of prints on which a clear image with no background stains and no missing fine lines or characters is obtained is represented as printing durability.

As shown in Table-J, Example 1 showed a good result in the charging characteristics, and the change was small even in the aged sample, which was within a range in which there was no practical problem. On the other hand, Comparative Example A had a small charge amount and a low charge fraction of particles. In addition, due to aging, the change in chargeability is large,
In particular, the charge fraction of the particles was significantly reduced. In Comparative Example B, the charge fraction was even lower, and the deterioration with time was remarkable.

Next, from the results of the ejection property and the shape of the dots on the printed plate material, Example 1 exhibited good performance in both the fresh product (condition I) and the aging product (condition II). . That is, in Comparative Example A, the film thickness was thin, and the dot shape was also blurred. Only the image of Example 1 showed good performance in both the fresh product and the aged product.

Further, when printing was performed using this printing plate, the printing durability of Example 1 was 10,000 sheets or more. Comparative Example A showed 3,000 sheets of printing durability in a fresh ink product. But,
In the case of the aged product, the image portion was missing from printing and was unusable, and the formed image portion was lost after printing about 1,000 sheets. In Comparative Example B, even with a fresh ink, the lack of an image was noticeable after printing.

From the above results, it can be seen that the ink of the present invention has a large charge amount of the whole ink and a high charge fraction of 90% or more even when the storage state is changed, and the dispersion of the particles with the passage of time. Good properties, no aggregation / precipitation. By these things, in the ink discharge of the electrostatic ink jet system, the ink meniscus is stably formed on the discharge electrode, and the charged particles in the ink are also electrophoresed quickly under voltage suppression, and the particles are concentrated. In this state, printing is performed on a printing original plate that is an ink receiving material. Therefore, the print dots on the plate material have a thick film thickness of 2.1 μm, and the dots are blurred in a circular shape, and no generation of distortion or the like is observed. Furthermore, when actually printing as a printing plate, since the thickness of the image portion is sufficient,
The printing durability was as good as 10,000 sheets or more.

On the other hand, in Comparative Example A, the chargeability of the ink changed greatly with the passage of time, and both the ejection property and the particle concentration property were insufficient for practical use, and the plate-making image formed was unsatisfactory. In Comparative Example B, the amount of charge of the ink was small, and the deterioration with the passage of time was extremely remarkable. From the above, only the oil-based ink of the present invention showed stable and good performance over time.

Examples 2 to 11 In Example 1, instead of 50 g of the resin particles (L-1) in the oil-based ink (IK-1), 50 g of each resin particle shown in the following Table-K (as solid content) was used. Otherwise, each oil-based ink was prepared in the same manner as in the oil-based ink (IK-1) and evaluated in the same manner as in Example 1.

[0238]

[Table 13]

Each oil-based ink (IK-2) to (IK-11)
Show the same charging characteristics as the oil-based ink (IK-1), and the AC electric conductivity of the sample under the condition II is 360 to 380.
(PS / cm) and the charge fraction of the particles was in the range of 88 to 93%. The actual ejection property, dot shape, image reproducibility and printing durability were all the same as or better than those of Example 1. Further, even with the lapse of time, almost no change in the chargeability of the ink was observed. Furthermore, these inks after aged for 6 months show no aggregation / precipitation of particles, good dispersibility,
The actual ejection performance also showed the same performance as before aging.

Example 12 <Preparation of a lithographic printing plate precursor> A composition having the following contents was put together with glass beads in a paint shaker and dispersed for 80 minutes. Then, the glass beads were separated by filtration to obtain a dispersion.

・ Silica: 40 g of Sylysia 445 (manufactured by Fuji Silysia Chemical Ltd.) ・ 20 g of colloidal silica: 200 g of Snowtec C (manufactured by Nissan Chemical Industries, Ltd.) ・ 40 g of clay dispersion 40 g ・ polyvinyl alcohol: PVA -117, 10% solution 120 g (manufactured by Kuraray Co., Ltd.)-Melamine resin 2.0 g-Ammonium chloride 0.2 g-Water 50 g

An ELP-2X master known as an electrophotographic lithographic printing plate precursor (Fuji Photo Film Co., Ltd.)
The above composition was coated on the support using a wire bar and heated at 110 ° C. for 10 minutes to form an image receiving layer having a coating amount of 6 g / m ^2. I got The surface smoothness of the obtained image receiving layer was 300 (sec / 10 ml) in Beck's smoothness, and the contact angle of the surface with water was 0 degree. This printing original plate was made in the same manner as in Example 1. However, the oil-based ink (IK-1) used in Example 1
Was replaced by an oil-based ink (IK-12) having the following content.

<Preparation of Oil-Based Ink (IK-12)> The resin particles (L-K) obtained in Production Example 25 of the resin particles (L) were obtained.
25) A mixture of 50 g (as solid content) and 3.5 g of Victoria Blue B was heated to a temperature of 100 ° C. and heated with stirring for 3 hours. After cooling to room temperature, a 200-mesh nylon cloth was passed through to remove the remaining dye, whereby a blue resin dispersion having an average particle diameter of 0.42 μm was obtained. 25 g of the above-mentioned blue resin dispersion (as solid content) and 0.15 g of cobalt naphthenate as a charge control agent were diluted in a mixed solution of hexamethyldisiloxane / Isoper G (3/2 mass ratio) to make a total volume of 1 liter. Thus, a blue oil-based ink was prepared.

The properties of the obtained ink were measured in the same manner as in Example 1, and the results as shown in Table L below were obtained. The chargeability, dischargeability, and dot shape were good even with the lapse of time.

[0245]

[Table 14]

Next, printing was performed in the same manner as in Example 1. The obtained printed matter has clear image quality with no stain on the non-image area, similarly to the printed matter of Example 1, and has a printing durability of 1
It was good with more than 10,000 sheets. In addition, when the performance was examined using the respective inks that had been stored for a long time (condition II) and 6 months under high temperature and high humidity, no aggregation or precipitation of particles was observed, and the results of actual plate making and printing were good with good dispersibility. Was as good as the fresh product.

Examples 13 to 28 Plate making and printing were performed in the same manner as in Example 12, except that the oil-based ink (IK-12) was replaced with each of the oil-based inks shown in Table M below. Was. The oil ink used was the oil ink (IK-1) in Example 12.
In place of the resin particles (L-25) used in 2), 50 g of each resin particle shown in the following Table-M (as solid content)
Other than using it, it was created similarly.

[0248]

[Table 15]

When the ink characteristics were evaluated in the same manner as in Example 12, the AC electric conductivity of the ink with each ink was 360.
380 (pS / cm), the charged fraction of particles is 90-95.
%Met. The image reproducibility was good, showing the same performance as that of Example 12. Further, when printing was performed as a printing plate, all plates exhibited a printing durability of 10,000 sheets or more. The aged ink also exhibited image reproducibility and printing durability equivalent to that of the fresh product, as in Example 12.

Example 29 <Preparation of Water-Resistant Support> 100 g / m ² weighed as substrate
Using a high-quality paper, a coating for underlayer having the following composition was applied to one surface of the substrate using a wire bar to provide an underlayer with a dry coating amount of 10 g / m ² . The smoothness of the under layer surface was 150 seconds / 10 ml, and the smoothness was adjusted to 1500 (second / 10 ml) by calendering.

<Coating for Under Layer>-10 parts by mass of silica gel-92 parts by mass of SBR latex (50% by mass aqueous dispersion, Tg: 25 ° C)-110 parts by mass of clay (45% by mass aqueous dispersion)-Melamine (80 5% by mass ・ Water 191 parts by mass

Further, a coating material for a back coat having the following composition was applied to the other surface of the substrate using a wire bar, and a back coat layer having a dry coating amount of 12 g / m ² was provided. Calendar processing was performed by setting calendar conditions so that the smoothness was about 50 (seconds / 10 ml).

<Coating for Back Coat Layer> 200 parts kaolin (50% aqueous dispersion) 60 parts aqueous polyvinyl alcohol solution (10%) 100 parts SBR latex (solid content 49%, Tg: 0 ° C.) 100 parts melamine resin Initial condensate 5 parts (solid content 80%, Sumiretz Resin SR-613)

<Preparation of lithographic printing plate precursor> Zinc oxide 100
g, 16 g of binder resin (B-1) having the following structure, 2 g of binder resin (B-2), 0.15 g of benzoic acid, and 1 part of toluene
55 g of the mixture was dispersed at a rotation speed of 6 × 10 ³ rpm for 8 minutes using a wet disperser homogenizer (manufactured by Nippon Seiki Co., Ltd.).

[0255]

Embedded image

This dispersion was coated on the above-mentioned water-resistant support using a wire bar so that the coating amount was 10 g / m ² .
By coating and drying, a lithographic printing original plate having a surface smoothness of 250 (seconds / 10 ml) was prepared. Surface contact angle with water is 10
It was twice.

<Preparation of oil-based ink (IK-29)> 10 g of dispersion stabilizing resin [P-1], black pigment (Microlith Bl)
ack CT, Ciba-Geigy) 10 g and Isopar E,
113 g was placed in a paint shaker together with the glass beads and dispersed for 6 hours, and the glass beads were separated by filtration to obtain a black dispersion. 60 g (as solid content) of resin particles (L-26) produced in Production Example 26 of resin particles (L), 66 g of the above black dispersion and 0.15 g of zirconium dioctylsulfosuccinate were mixed with hexamethyldisiloxane in a total volume of 1 liter. Diluted to give a black oil-based ink (IK-2
9) was created. The AC conductivity of the obtained ink is 3
50 (pS / cm) and the charged fraction of the particles was 95%.

The above printing original plate and oil-based ink (IK-2
A plate was made in the same manner as in Example 1, except that 9) was used, to obtain a plate having a clear image with no loss of fine lines and characters. The thickness of the dot was 2.3 μm, and it was a good circular dot without bleeding or distortion. The sample under condition II shown in Example 1 also had good dispersibility and a small change in chargeability.

Next, with respect to the plate-making products prepared by using fresh and time-lapsed oil-based inks, a desensitizing solution (ELP-E2, manufactured by Fuji Photo Film Co., Ltd.) was applied to a fully automatic printing machine (AM). -2850, put in an etcher part of ASM Co., Ltd., and as a fountain solution, a desensitizing solution (E
A solution obtained by diluting LP-E2) four times with distilled water was placed in a fountain solution tray, and printing was performed using black ink for offset printing. As a result, more than 3,000 printed images with clear images free of background stains were obtained.

Examples 30 to 33 Plate making was performed in the same manner as in Example 12, except that the oil inks (IK-12) were replaced with the oil inks shown in Table N below. The oil-based ink used was replaced with the resin particles (L-25) used in the oil-based ink (IK-12) in Example 12 by using the following Table-P
Was prepared in the same manner except that 50 g (as a solid content) of each resin particle shown in (1) was used.

[0261]

[Table 16]

Oil-based inks (IK-30) to (IK-3)
Table-N shows the charging characteristics, ejection properties, and dot shapes under the condition II of 3). Very good results were obtained in the same manner as in Example 12 also for the sample aged like the fresh product. As a result of actual printing, printing durability of 10,000 sheets or more was shown.

[0263]

By using the oil-based ink of the present invention, it is possible to form an image excellent in ink ejection stability, clear image forming property and image strength, and to obtain a clear image in an electrostatic ink jet recording system. A printing plate capable of printing a large number of printed matters can be provided.
Further, according to the oil-based ink for electrostatic ink jet of the present invention, the dispersibility of the dispersed particles and the storage stability are excellent, the ink is not clogged in the ink supply path, and the ejection of the ink is stabilized.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an example of an apparatus system to which the oil-based ink of the present invention can be applied.

FIG. 2 is a diagram showing a part of a head of an ink jet recording apparatus to which the oil-based ink of the present invention can be applied.

FIG. 3 is a diagram in which a meniscus regulating plate is removed from the head shown in FIG. 2;

FIG. 4 is a view showing a discharge test apparatus used in the examples.

[Explanation of symbols]

 1 Inkjet recording apparatus 2 Lithographic printing master (master) 3 Computer 4 Bus 10 Inkjet recording head 13 Inkjet recording head 14 Head body 15, 16 Meniscus regulating plate 17 Ejection electrode 18 Ink groove 19, 21 Partition 20, 20 'Ejection Part 22 Tip part 31 Drum-shaped counter electrode 32 Recording medium 33 Power supply 34 Recording head 35 Liquid feed pump 36 Ink tank 37 Waste liquid tank

Claims (3)

[Claims] 1. An oil ink for electrostatic inkjet comprising at least charged resin particles dispersed in a non-aqueous carrier liquid having an electric resistance of not less than 10 ⁹ Ω · cm and a dielectric constant of not more than 3.5. A resin particle which is soluble in a non-aqueous solvent and which contains at least one monofunctional monomer (A) which is insoluble by polymerization, containing an amino group represented by the general formula (I). At least one monofunctional monomer (B) copolymerizable with the monomer (A), containing -SO ₃ H and / or -SO ₂ H groups and copolymerizable with the monomer (A) Copolymer resin obtained by polymerizing and granulating a solution containing at least one monofunctional monomer (C) and at least one dispersion stabilizing resin [P] soluble in the non-aqueous solvent. Particles, the dispersion stabilizing resin [P] is a block And block B
Is a star-type copolymer in which at least three of the AB-type block polymer chains are bonded to organic residues, and each AB-type block polymer chain is a fragment of the block A. The terminal type is bonded to the organic residue, the weight average molecular weight of the star copolymer is 2 × 10 ⁴ to 1 × 10 ⁶ , and the block A corresponds to the monofunctional monomer (A). At least one polymer component and a phosphono group, a carboxyl group, a sulfo group, a hydroxyl group, a formyl group,
An amino group, —P (＝ O) (OH) E ¹ group, [E ¹ is —E ²
A group or -OE ² group, wherein E ² represents a hydrocarbon group],
—CONE ³ E ⁴ group, —SO ₂ NE ³ E ⁴ group [E ³ and E ⁴
Each independently represents a hydrogen atom or a hydrocarbon group) and at least one polymer component selected from polymer components containing at least one polar group selected from cyclic acid anhydride-containing groups, The block B contains at least one polymer component represented by the following general formula (II). Embedded image In the general formula (I), R ¹ and R ² may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms, or R ¹ and R ² are bonded together with a nitrogen atom. A ring may be formed. Embedded image In the general formula (II), X ¹ represents -COO-, -OCO-,-(C
_{H 2) x COO -, -} (CH 2) x OCO- [where x is 1
Represents an integer of to 3] or -O-. Y ¹ represents an aliphatic group having 8 or more carbon atoms. b ¹ and b 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 7 carbon atoms, -COO-
Z ¹ or —COO—Z ¹ via a hydrocarbon group (here, Z ¹ represents a hydrogen atom or a hydrocarbon group having 1 to 22 carbon atoms). 2. In the dispersion stabilizing resin [P], each block of the AB block copolymer component constituting each polymer chain has a block A / block B ratio of 1 to 5.
The oil-based ink for electrostatic ink jet according to claim 1, wherein the ratio is 0/99 to 50 (mass ratio). 3. The dispersed resin particles further contain at least one monofunctional monomer (D) represented by the following general formula (IV) copolymerizable with the monomer (A). The oily ink for electrostatic inkjet according to claim 1 or 2, wherein the resin ink is a copolymer resin particle obtained by polymerizing and granulating a solution. Embedded image In the general formula (IV), U ¹ represents -COO-, -CONH-,-
CON (D ² ) — (where D ² represents an aliphatic group or a substituent represented by the following general formula (Va)), —OCO—,
_{-CONHCOO -, - CH 2 COO -} , - (CH 2) S
OCO-, (where s represents an integer of 1 to 4), -O
— Or —C ₆ H ₄ —COO—. c ¹ and c ² are
Same or different, each represents a hydrogen atom, an alkyl group, a halogen atom, a cyano group, -COO-D ³ or -CH ₂ CO
O-D ³ (wherein D ³ represents an aliphatic group). E ¹ is an aliphatic group having 8 or more carbon atoms and a total of 8 or more atoms (provided that
(Excluding a hydrogen atom directly bonded to a carbon atom or a nitrogen atom)) and a group represented by the following general formula (IVa). Formula (IVa)-(A ¹ -B ¹ ) _m- (A ² -B ² ) _n -R ^{21 In the} general formula (IVa), R ²¹ is a hydrogen atom or a group having 1 to 1 carbon atoms.
8 represents an aliphatic group. B ¹ and B ² are the same or different and are each -O-, -S-, -CO-, -CO ₂ -,-
_{OCO -, - SO 2 -,} - N (R 22) -, - CON (R
^{22) -, - N (R} 22) CO -, - N (R 22) SO 2 -,
^{_{SO 2 N (R 22) -}} , - NHCO 2 - or -NHCON
Represents H- (here, R ²² has the same meaning as R ²¹ above).
A ¹ and A ² are the same or different and each represent at least one group selected from a group represented by the following formula (IVb) and a hydrocarbon group having 1 to 18 carbon atoms. m and n are the same or different and each represents an integer of 0-4. However, there is no possibility that m + n = 0. Embedded image In the general formula (IVb), B ³ and B ⁴ are the same or different and have the same meaning as B ¹ and B ² above, and A ⁴ has 1 to 18 carbon atoms.
Wherein R ²³ has the same meaning as R ²¹ described above. p
Represents an integer of 0 to 4.