JPH0243181B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention uses an organic photoconductive compound to form a toner image by electrophotography, and the non-image area other than the toner image forming area is etched with a solution mainly composed of alkali and/or alcohol. It concerns the manufacturing method. An object of the present invention is to provide a printing plate that forms a tough film. Another object of the present invention is to provide a printing plate having high printing durability. Still another object is to provide a printing plate which can be easily etched with a solution containing alkali and/or alcohol as a main component. Furthermore, when applying to a support for other purposes,
The object of the present invention is to provide a binder composition that allows a stable coating state to be obtained. Many printing plates using organic photoconductive compounds are already known, for example, Japanese Patent Publication No. 37-17162,
38-6961, 41-2426, 46-39405, JP-A-50-19509, 50-19510, 54-145538
No. 54-89801, No. 54-134632, No. 54-
Examples include No. 19803 and No. 55-105254. Binders used in these printing plates include styrene maleic anhydride copolymer, maleic ester resin, vinyl acetate-crotonic acid copolymer, vinyl acetate-maleic anhydride copolymer, phenol resin, etc. . However, when these are used in printing plates using organic photoconductive compounds,
It has various drawbacks, especially when a high degree of printing durability is required. When a styrene maleic anhydride copolymer is used as a binder, the film formed is hard and may crack when the printing plate is bent. This is thought to be due to the molecules being relatively rigid and highly crystalline, and the film surface easily peels off even in the tape adhesion test described below. It has been considered to add a plasticizer to improve this property, but adding a plasticizer tends to deteriorate the charging characteristics. Furthermore, if a high boiling point oil is used as a plasticizer, the oil oozes out onto the surface of the printing plate, resulting in poor stability over time. When a phenol resin is used as a binder, it has the same physical properties as a styrene-maleic anhydride copolymer. Generally, phenolic resins have a small molecular weight and a low viscosity in a solution state. Furthermore, the film formed is fragile. Therefore, phenolic resins are not suitable for printing plates with high printing durability. Vinyl acetate-crotonic acid and vinyl acetate-maleic anhydride copolymers are quite suitable as binders for printing plates. However, when producing tens of thousands of prints, there is a drawback that fine details may be skipped. When an acrylic resin, which is a homopolymer of acrylic ester or methacrylic ester, is used as a binder, images can be formed by electrophotography, but alkali and/or alcohol etching treatment is not easy, which is the object of the present invention. Print version not available. The object of the present invention is to use a synthetic polymer compound containing at least one monomer of acrylic ester and/or methacrylic ester as a binder and 10 to 70 mol percent of the general formula CHR ₁ =CR ₂ COOH as an acid group-containing monomer. This was achieved by using However, R ₁ represents a hydrogen atom or a methyl group, and R ₂ represents a hydrogen atom, a methyl group, or a -CH ₂ COOH group. By using the above synthetic polymer compound in the printing plate of the present invention, the following effects were obtained. That is, compared to known binders such as styrene-maleic anhydride resin and phenol resin, a tough film is formed, and cracking caused by bending is eliminated, and the adhesion to the support is improved, resulting in a reduction in the number of prints. Achieving high printing durability, which means that images do not become distorted even after printing tens of thousands of sheets. The etching speed is fast and rapid processing is possible. Examples of ester acid groups of acrylic esters and methacrylic esters include methyl, ethyl, n
-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, n-amyl,
3-pentyl, 2-methyl-1-butyl, 3-methyl-1-butyl, n-hexyl, 2-methyl-
1-pentyl, 2-ethyl-1-butyl, sec-
amyl, t-amyl, 4-methyl-2-pentyl, n-heptyl, 2-heptyl, 2-octyl, 2-ethyl-1-hexyl, 2-octyl,
n-nonyl, n-decyl, 5-ethyl-2-nonyl, n-dodecyl, n-tetradecyl, n-hexadecyl, cyclohexyl, 2-methylcyclohexyl, 3-methylcyclohexyl, 4-t-amylcyclohexyl, phenyl, O -Truil,
P-t-butylphenyl, 2-chloroethyl, 3
-Chlorpropyl, pentachlorphenyl, 2-
Hydroxyethyl, 3-hydroxybutyl, 2-
Methoxyethyl, 2-ethoxyethyl, 2-butoxyethyl, glycidyl, 3.4-epoxy-6-
Examples include methylcyclohexylmethyl, tetrahydrofurfuryl, trifluoropropyl, 1,1,5-trihydroperfluoropentyl, 1,1,3-trihydroperfluoropropyl, and the like. Representative compounds are illustrated below. Examples of synthetic polymer compounds (1) Butyl acrylate acrylic acid (70:30) (2) Butyl methacrylate-methacrylic acid
(80:20) (3) 2-Ethylhexyl acrylate-methacrylic acid (70:30) (4) Ethyl acrylate-methacrylic acid
(80:20) (5) Methyl methacrylate-butyl acrylate-acrylic acid (40:20:40) (6) Butyl acrylate-itaconic acid (85:15) (7) Methyl methacrylate-methyl acrylate-methacrylic acid (40:30:30) (8) 2-ethylhexyl acrylate-methyl methacrylate-acrylic acid (30:60:10) (9) Lauryl methacrylate-acrylic acid
(80:20) (10) 2-ethylhexyl acrylate-crotonic acid (90:10) (11) Methyl methacrylate-butyl acrylate-crotonic acid (50:35:15) (12) Methyl methacrylate-lauryl methacrylate acrylic acid (10:30:60) These synthetic polymer compounds can be used for bulk polymerization, solution polymerization, and peroxide or azo compounds as polymerization initiators.
It can be synthesized very easily by suspension polymerization, and the synthesis method is generally well known. From the point of view of the printing plate manufacturing process, it is convenient to carry out solution polymerization using a solvent having substantially the same composition as the solvent of the coating liquid. The molecular weight is
It can be used in the range of 1,000 to 500,000, but the strength of the formed film and the etching speed are from 8,000 to 500,000.
A range of 150000 is preferred. Examples of the organic photoconductive compound used in the printing plate of the present invention include the following compounds. (a) Aromatic tertiary amino compounds: triphenylamine, diphenylbenzylamine, di-(β-
naphthyl) benzylamine, diphenylcyclohexylamine, etc. (b) Aromatic tertiary diamino compound: N, N, N',
N'-tetrabenzyl-p-phenylenediamine, N,N,N',N'-tetrabenzylbenzicine, 1,1'-bis-(4-N,N-dibenzylaminophenyl)-ethane, 2,2-bis(4-N,N-dibenzylaminophenyl)-butane, bis-(4-N,N-di-(p-chlorobenzylaminophenyl))-methane, 3,3-diphenyl enylallyridine-4,4'-bis(N,N-
diethyl-m-toluidine), 4,4'-bis(di-p-tolylamino)-1,1,1-triphenylethane, etc. (c) Aromatic tertiary triamino compound: 4,4′,
4″-tris(diethylaminophenyl)methane, 4-dimethylamino, 4,4″-bis(diethylamino)-2,2″-dimethyl-triphenylmethane, etc. (d) Main condensation product: aldehyde and aroma condensation products of group amines, reaction products of tertiary aromatic amines and aromatic halides, poly-p-phenylene-1,
3,4-oxadiazole, a reaction product of formaldehyde and a condensed polycyclic compound, etc. (e) Metal-containing compounds: 2-mercapto-benzothiazole zinc salt, 2-mercapto-benzoxazole lead salt, 2-mercapto-6-methoxybenzimidazole-lead salt, S-hydroxy-
Quinoline-aluminum salt, 2-hydroxy-
4-methyl-azobenzene-copper salt, (f) polyvinylcarbazole compound: polyvinylcarbazole, halogen-substituted polyvinylcarbazole, copolymer of vinylcarbazole and styrene, copolymer of vinylanthracene-vinylcarbazole, etc. (g) Heterocyclic compound: 1,3,5-triphenyl-
Pyrazoline, 1-phenyl-3-(p-dimethylaminostyryl)-5-(p-dimethylaminophenyl)-pyrazoline, 1,5-diphenyl-3-styryl-pyrazoline, 1,3-diphenyl-5-styryl -pyrazoline, 1,3-diphenyl-5-(p-dimethylaminophenyl)
-pyrazoline, 3-(4′-dimethylaminophenyl)-5,6-di-(4″-methoxyphenyl)
-1,2,4-triazine, 3-(4'-dimethylaminophenyl)-5,6-dipyridyl-1,
2,4-triazine, 2-phenyl-4(4'-
dimethylaminophenyl)-quinazoline, 6-
Hydroxy-2,3-di(P-methoxyphenyl)-benzofuran, 2,5-bis-[4'-ethylamino-phenyl-(1')]1,3,4-oxadiazole, and the like. The organic photoconductive compound used in the present invention is
Good printing plates can also be obtained using pigments such as phthalocyanine pigments, quinacridone pigments, indigo pigments, cyanine pigments, perylene pigments, bisbenzimidazole pigments, quinone pigments, azo pigments, and indigo pigments. As the base for the printing plate of the present invention, all conventionally known bases for printing plates can be used. For example, metal plates such as aluminum plates, zinc plates, magnesium plates, copper plates, etc. Films and synthetic papers made of polyester, cellulose acetate, polystyrene, polycarbonate, polyamide, polypropylene, etc. Examples include processed paper such as resin-coated paper, but since the photoconductive compound and binder are removed by etching after image formation and the non-image area must have hydrophilic properties, hydrophobic The base having a surface needs to be hydrophilized in advance. A metal plate, particularly an aluminum plate, is most suitable, but surface treatments such as graining, alkal treatment, acid treatment, and anodizing are preferred. In the case of films, it is recommended that they be coated with a relatively highly hydrophilic polymer compound and cross-linked, or that a certain type of metal be vapor-deposited or laminated. When using an insulating base, it is desirable to perform conductive treatment on the base surface. To produce a printing original plate, the photoconductive compound and the binder of the present invention are dissolved in a solvent (if the photoconductive compound is not dissolved, a dispersion is prepared using a colloid mill, homogenizer, ultrasonic disperser, etc.). ), a sensitizing dye is added and coated on the support to a thickness of 1 to 30 μm and dried. The ratio of the photoconductive compound to the binder is 0.01 to 50 parts by weight, preferably 0.2 to 10 parts by weight, depending on the binder and photoconductive compound used, per 1 part by weight of the photoconductive compound. It is. Those that can be used as solvents include all organic solvents that are capable of dissolving the binder and dissolving or dispersing the photoconductive compound. For example, alcohols such as methanol, ethanol, propanol, butanol, hexyl alcohol, methyl cellosolve, ethyl cellosolve,
Cellosolves such as butyl cellosolve, benzene,
Aromatics such as toluene and xylene, dioxane,
Cyclic ethers such as tetrahydrofuran, esters such as ethyl acetate, butyl acetate, allyl acetate,
Ketones such as acetone, methyl isobutyl ketone, methyl ethyl ketone, dimethyl formamide,
Examples include dimethyl sulfoxide and halogenated hydrocarbons, but two or more solvents are often used as a mixture in view of solubility, cost, safety, and the like. The toner used for image formation may be either a so-called dry toner or a wet toner, but in order to obtain printed matter with excellent resolution, a wet toner produced by a liquid development method is far more preferable. In addition, since the toner is used as a printing plate, it is hydrophobic and has ink receptivity.
In addition, it must have sufficient adhesion to the printing plate to withstand printing, and must also have resistance to alkali and/or alcohol etching.
Examples of toners that meet these conditions include styrene resins, acrylic resins, polyester resins, and epoxy resins. Further, it is practically preferable to contain pigments and dyes for coloring, and a charge control agent within a range that does not adversely affect the stability and fixing properties of the toner. The printing plate of the present invention is obtained by forming a toner image on a printing original plate by an electrophotographic method, and then etching the non-image area with an alkali and/or alcohol solution. Examples of the alkali include sodium hydroxide, sodium carbonate, sodium silicate, sodium phosphate, potassium phosphate, and ammonia. Methanol is alcohol,
Lower alcohols and aromatic alcohols such as ethanol, propanol, benzyl alcohol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol,
Examples include cellosolves. Etching can be performed using an alkaline aqueous solution alone or alcohol alone, but it is preferable to use amino alcohols such as monoethanolamine, diethanolamine, triethanolamine, etc. from the etching speed, safety and hygiene aspects, and from the viewpoint of resolution and image reproducibility. Most preferred is a combination of amino alcohols and alcohols. Further, it is preferable to add a small amount of surfactant to speed up etching. When this etching treatment is followed by washing with water and treatment with a diluted acid aqueous solution, it exhibits excellent properties in terms of scumming and image reproducibility during printing. Etching treatment liquid example Monoethanolamine 40ml Diethanolamine 10ml Ethanol 250ml Polyethylene glycol (molecular weight 600)
40ml Water 300ml Example 1 Preparation of printing plate (a) 100g of synthetic polymer compound (2) and 500g of xylene
and 200 g of butanol in a mixed solvent to obtain a binder solution. In this solution, 70 g of 1,3,5-triphenylpyrazoline was dissolved as an organic photoconductive compound, 50 g of a 1% DMF solution of Rhodamine B as a sensitizing dye was added, and the total amount was adjusted to 1000 g with xylene. The coating was applied to a grained and anodized aluminum plate of 100 μm so that the solid content was 5 g/m ² and dried to obtain a printing original plate (A). Printing master plates obtained from synthetic polymer compounds (4), (5), and (7) in exactly the same manner as (B),
(C) and (D). In addition, a printing original plate prepared in the same manner using styrene maleic anhydride copolymer as a synthetic polymer compound (Comparison A-1) was prepared from vinyl acetate-crotonic acid copolymer (10% by weight of crotonic acid). What you created (Comparison A-
2). (b) 100 g of synthetic polymer compounds (5) and (11) were each dissolved in a mixed solvent of 500 g of toluene and 200 g of butanol to prepare a binder solution. In this solution, 70 g of 4,4''-bis(diethylamino)-2,2''-dimethyl-triphenylmethane was dissolved as an organic photoconductive compound, and 80 g of a 1% DMF solution of ethyl violet was added as a sensitizing dye. The total amount was adjusted to 1000 g with xylene. It was coated on the aluminum plate used in Example 1(a) so that the solid content was 5 g/m ² and dried to obtain printing original plates (E) and (F). or,
A printing original plate prepared in a similar manner using a phenol resin (molecular weight 1000), which is a condensation polymer of formalin and tert-butylphenol, as a synthetic polymer compound was designated as (Comparison B). In addition, since the comparative sample had a low solution viscosity, coating unevenness was likely to occur during coating and drying, making it difficult to obtain a printing original plate coated uniformly. (c) Add 100g of synthetic polymer compounds (2) and (8) to 400g of xylene, 100g of toluene, and butanol, respectively.
It was dissolved in 100 g of a mixed solvent to obtain a binder solution. Add 20g of α-type copper phthalocyanine as an organic photoconductive compound to this solution, disperse it for 10 minutes using an ultrasonic disperser, and apply it to the aluminum plate used in Example 1(a) so that the solid content is 5g/m2. After drying, printing original plates (G) and (H) were obtained. A printing original plate using a styrene maleic anhydride copolymer was designated as (Comparative C). Example 2 (a) The original printing plates (A) to (H) obtained in Example 1 and comparisons (A), (B), and (C) were placed in a cylinder with a radius of curvature of 20 mm at a speed of once per second. The coated surface was observed. Those with weak binder physical properties cracked or became opaque as shown in the results below. (b) After strongly adhering the coated surface to the adhesive tape,
The tape was peeled off at once and the coated surface was observed to examine the strength and adhesion of the coated film surface.

【table】

[Table] It is clear from the results in the table that when the binder of the present invention is used, it has excellent adhesion to the support and has strong binder physical properties. Example 3 The original printing plate obtained in Example 1 was prepared in a dark place.
After applying a 6 kV corona discharge to negatively charge the sample, a positive image was exposed to white light. Immediately develop the liquid toner using Diamond Ax Master toner (manufactured by Mitsubishi Paper Industries).
Heat fixed with fuser. These were immersed in the above-mentioned etching treatment solution, and while being rubbed lightly with a sponge, the time until the aluminum surface of the non-image area other than the toner image was etched and exposed was measured. Furthermore, after washing the printing plate thus obtained with water, a printing durability test was conducted on a Ryobi KR2700 printing machine using compounded Tak 15 ink.

【table】

[Table] As can be seen from the results, the use of the synthetic polymer compound of the present invention shortens the etching time and is extremely advantageous in rapid processing. Furthermore, it showed excellent properties in the printing durability test and can be said to be suitable as a printing plate with high printing durability.

Claims (1)

[Scope of Claims] 1. After forming a toner image on a printing original plate having a layer containing an organic photoconductive compound by electrophotography, a non-image area other than the toner image forming area is treated with an alkali and/or alcohol. In the method for producing a printing plate by etching with a solution as a component, as a binder for the organic photoconductive compound, at least one monomer of acrylic ester and/or methacrylic ester and as an acid group-containing monomer, the general formula CHR is used. ₁ = CR ₂ COOH (However, R ₁ is a hydrogen atom or a methyl group. _{R 2} is a hydrogen atom, a methyl group, or a -CH ₂ COOH group.) 10~
A method for producing a printing plate characterized by using a synthetic polymer compound containing 70 mole percent.