JPS63183441A - Photosensitive composition having excellent chemical resistance and inking property - Google Patents

Abstract

PURPOSE:To improve processing chemical resistance and inking property by incorporating a specific high-polymer compd., condensed resin of substd. phenols and aldehydes and/or the o-naphthoquinonediazide sulfonate compd. thereof into a titled compsn. CONSTITUTION:The high-polymer compd. having the structural unit expressed by the formula I [R1, R2 are respectively H, halogen atom, alkyl, aryl, carboxyl, etc., R3 is H, halogen atom, alkyl, aryl, R4 is H, alkyl, aryl, aralkyl, Y is (substd.)arom. group, X is a bivalent org. group, n is 0-5] and the condensed resin of the substd. phenols expressed by the formula II (R5, R6 are respectively H, alkyl, halogen atom, R7 is alkyl of >=2C, cycloalkyl) and aldehydes and/or the o-naphthoquinonediazide sulfonate of said resin are incorporated into the compsn. A photosensitive planographic printing plate formed by using such photosensitive compsn. has the excellent processing chemical resistance, particularly the good resistance to plate cleaners and cleaning liquids used for UV ink printing and has an excellent ink receptive property as well.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a photosensitive composition suitable for positive-working photosensitive lithographic printing plates, and more specifically to a photosensitive composition that has excellent processing chemical resistance and ink receptivity. The present invention relates to a photosensitive composition suitable for positive-working photosensitive lithographic printing plates.

(Background of the Invention and Prior Art) A positive-working photosensitive lithographic printing plate generally has an ink-receptive photosensitive layer formed on a hydrophilic substrate, which becomes solubilized by exposure to light. When this photosensitive layer is subjected to imagewise exposure and development, the non-image areas are removed while leaving the image areas, thereby forming an image. In the mark qH, the difference in properties that the image area is lipophilic and the non-image area is hydrophilic is utilized.

Positive-working photosensitive lithographic printing plates have low resistance to various processing chemicals used during printing, such as isopropyl alcohol contained in fountain solution, ink, surface preparation liquid, plate cleaner, etc. However, it has the disadvantage that printing durability is reduced. Japanese Patent Publication No. 43-28403 describes that the treatment chemical resistance was improved by using 0-naphthoquinonediazide sulfonic acid ester of a polycondensation resin of pyrogallol and acetone as a photoreceptor. It showed some good performance against the processing chemicals used in printing with conventional oil-based inks. However, in recent years (printing using ultraviolet curable U-ink) has been increasing.

For the inks and processing chemicals (washing oil, plate cleaners, etc.) used in UV ink printing, the above-mentioned photoreceptor is durable when using ordinary novolac resins such as m-cresol novolac resins as binders. Inadequate sex. Moreover, in Japanese Patent Publication No. 56-54621, phenol and m-.

A photosensitive composition containing as a binder a resin obtained by copolycondensing p-mixed cresol and aldehyde,
Although it is described that the resin improves resistance to processing chemicals, the resin also has very insufficient resistance to the processing chemicals used in JV ink printing. Tokuko Sho 52-284
The photosensitive composition disclosed in Publication No. 01 is described to contain a photoreceptor made of an O-naphthoquinonediazide acid derivative and a binder made of a polymer compound containing p-hydroxymethacrylanilide or the like as a repeating structural unit. ing. Using this binder improved resistance to processing chemicals used in UV ink printing.

However, it has the disadvantage of poor ink receptivity.

(Objective of the Invention) Therefore, an object of the present invention is to provide a photosensitive composition suitable for a photosensitive lithographic printing plate having excellent processing chemical resistance and ink receptivity.

(Structure of the Invention) The object of the present invention is to provide (A) a polymer compound having a structural unit represented by the following general formula [I], (B) a substituted phenol represented by the following general formula [I], and an aldehyde. and/or a resin condensed with
Or, it is achieved by a photosensitive composition containing an 0-naphthoquinonediazide sulfonic acid ester compound of the resin.

General formula [I] +CR1R2-CR3+ (wherein R1 and R2 each represent a hydrogen atom, a halogen atom, an alkyl group, an aryl group, or a carboxyl group or a salt thereof, and R3 represents a hydrogen atom, a halogen atom, an alkyl group, or an aryl group) group, R4 represents a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group, Y represents an aromatic group that may have a substituent, X represents a divalent organic group, and n represents O General formula [II] (In the formula, R5 and R6 each represent a hydrogen atom, an alkyl group, or a halogen atom, and R7 represents an alkyl group or a cycloalkyl group having 2 or more carbon atoms.) The present invention will be explained in detail below.

The polymer compound having a structural unit represented by the above general formula [E] of the present invention may be a homopolymer having a repeating structure of only the above structural unit, but in addition to the above structural unit, one
It may be a species or a copolymer having two or more types of monomer units.

In the above structural unit, R1 and R2 are preferably a hydrogen atom, an alkyl group such as a methyl group or an ethyl group, or a carboxyl group or a salt thereof (ammonium salt and alkali metal salt), and more preferably a hydrogen atom. R3
is preferably a hydrogen atom, a halogen atom such as bromine or chlorine, or an alkyl group such as a methyl group or an ethyl group, and more preferably a hydrogen atom or a methyl group. Y is preferably a phenylene group or a naphthylene group which may have a substituent, and examples of the substituent include alkyl such as methyl and ethyl, halogen atoms such as bromine and chlorine, carboxyl group or its salt, and methoxy group. Examples include alkoxy groups such as ethoxy groups, hydroxyl groups, sulfo groups, cyano groups, nitro groups, and acyl groups. More preferably, Y is an unsubstituted phenylene group or a naphthylene group having a methyl group. X is a divalent organic group connecting a nitrogen atom and an aromatic carbon, preferably an alkylene group, and n is an integer of O to 5, preferably an integer of O to 3, more preferably O. be.

In the polymer compound of the present invention having a copolymer-type structure, monomer units that can be used in combination with the structural unit represented by the general formula [I] include, for example, ethylene, propylene, isobutylene, butadiene. , ethylenically unsaturated olefins such as isoprene, styrenes such as styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene, acrylic acids such as acrylic acid and methacrylic acid, such as itaconic acid and maleic acid. , unsaturated aliphatic dicarboxylic acids such as maleic anhydride, such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, α-chloroacrylate α- such as methyl acid, methyl methacrylate, ethyl methacrylate, ethyl ethacrylate, etc.
Esters of methylene aliphatic monocarboxylic acids, such as nitriles such as acrylonitrile and methacrylonitrile, amides such as acrylamide, such as acrylanilide, p-chloroacrylanilide, m-nitroacrylanilide, m-methoxyacrylanilide, etc. Anilides, such as vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, isobutyl vinyl ether, β-chloroethyl vinyl ether, vinyl chloride, vinylidene chloride, vinylidene cyanide, e.g. 1-methyl-
1-methoxyethylene, 1゜1-dimethoxyethylene,
Ethylene derivatives such as 1,2-dimethoxyethylene, 1,1-dimethoxycarbonylethylene, 1-methyl-1-ditroethylene, such as N-vinylpyrrole, N-
There are vinyl monomers such as N-vinyl compounds such as vinylcarbazole, N-vinylindole, N-vinylpyrrolone, and N-vinylpyrrolidone. These vinyl monomers exist in polymer compounds with a structure in which unsaturated double bonds are cleaved.

Among the above monomers, (meth)acrylic acids, aliphatic monocarboxylic acid esters, and nitriles have excellent overall performance when used in combination with the structural unit represented by general formula [I]. is preferred. More preferred are methacrylic acid, methyl methacrylate, acrylonitrile, ethyl acrylate, and the like.

These monomers may be bound in a block or random manner in the polymer compound.

A polymer compound having a structural unit represented by the general formula [I] of the present invention (hereinafter referred to as "binder resin of the present invention")
Here are some representative examples. In the compounds exemplified below, MW is the weight molecular weight average, LMn is the number average molecular weight, s, Q, m and n are (R,, R2 is a hydrogen atom, an alkyl group or a halogen group) (R, ~R5 is a hydrogen atom, an alkyl group, or a halogen atom) (X is an alkyl group or a halogen atom) (R is a hydrogen atom, an alkyl group, or a halogen atom) λ (X is an alkyl group or a halogen atom) (Rl is a hydrogen atom, (R, -R, are hydrogen atoms, alkyl groups, or halogen atoms) (R, -R are hydrogen atoms, alkyl groups, or halogen atoms) (R, -R3 are hydrogen atoms, alkyl groups, or halogen atoms) halogen atom) (R, ~ is a hydrogen atom, an alkyl group, or a halogen atom) More specifically, a-2) b-1) H3 c-2) CH.

d-1) CH.

d-2) CH3 CH.

g-1) h-1) The binder resin of the present invention can be synthesized as follows. First, α, β-unsaturated acid chlorides or α, β-unsaturated acid anhydrides are reacted with R primary or secondary amines having a phenolic hydroxyl group using a basic catalyst as necessary. Then, a monomer having a structural unit represented by the general formula [I] is synthesized. Next, the binder resin of the present invention can be obtained by homopolymerizing the monomer according to a conventional method, or by copolymerizing the monomer and at least one other vinyl monomer. At this time, the molecular weight of the binder resin and the molar ratio of each structural unit can be set over a wide range by varying the charging molar ratio of each carmer and the polymerization conditions. but,
In order to effectively serve the purpose of the present invention, the weight average molecular weight should be 5.0 x 103 to 1. OX 1Q5 is suitable, preferably 5.0X1Q3 to 4.0X104
It is.

The molar content of the structural unit represented by the general formula [I] is preferably at least 10 mol%.

More preferably, it is 20 to 40 mol%.

The content of the binder resin of the present invention in the photosensitive composition is preferably 30 to 95% by weight, more preferably 50% by weight.
~85% by weight.

Further, the molecular weight of the binder resin is measured by GPC (gel permeation chromatography).

In the general formula [U], R5 and R6 each represent a hydrogen atom, an alkyl group (including those containing 1 to 3 carbon atoms; an alkyl group having 1 to 2 carbon atoms are particularly useful), or a halogen atom. (Among fluorine, chlorine, bromine and iodine, chlorine and bromine are particularly preferred),
R7 is an alkyl group having 2 or more carbon atoms (preferably 1 carbon number)
5 or less and having 3 to 8 carbon atoms are particularly useful. ) or a cycloalkyl group (including those containing 3 to 15 carbon atoms; cycloalkyl groups containing 3 to 8 carbon atoms are particularly useful).

Examples of the substituted phenols include isopropylphenol, tart-butylphenol, tert-amylphenol, hexylphenol, tert-octylphenol, cyclohexylphenol, 3-methyl-4-chloro-5-tert-butylphenol, isopropylcresol, tert- butyl cresol, t
ert-amyl cresol, hexyl cresol, te
These include rt-octylcresol, cyclohexylcresol, etc., and among them, tert-octylphenol and tert-butylphenol are particularly preferred.

Examples of the aldehydes include aliphatic and aromatic aldehydes such as formaldehyde, benzaldehyde, acetaldehyde, acrolein, crotonaldehyde, and furfural, including those having 1 to 6 carbon atoms. Among them, formaldehyde and benzaldehyde are preferred.

The resin obtained by condensing the substituted phenol and aldehyde in the present invention is synthesized by polycondensing the substituted phenol represented by the general formula [I] and the aldehyde in the presence of an acidic catalyst. The acidic catalyst used is inorganic or organic acids such as hydrochloric acid, oxalic acid, sulfuric acid, phosphoric acid, etc., and the blending ratio of substituted phenols and aldehydes is as follows:
Aldehydes are 01 to 1 mole part of substituted phenols.
1.0 mole part is used. The reaction solvent is alcohol,
Acetone, water, tetrahydrofuran, etc. are used.

After reaction at a predetermined temperature (-5 to 120°C) for a predetermined time (3 to 48 hours), heat under reduced pressure, wash with water, and dehydrate.
Alternatively, the reactant can be obtained by precipitating water.

The O-naphthoquinonediazide sulfonic acid ester compound of the polymerized resin of substituted phenols and aldehydes of the present invention can be prepared by dissolving the condensed resin in a suitable solvent, such as dioxane, and adding O-naphthoquinonediazide sulfonic acid chloride to the solution. is added, and an alkali such as an alkali carbonate is added dropwise to the equivalence point while heating and stirring to esterify the product.

In the esterified product, the condensation rate of 0-naphthoquinonediazide sulfonic acid chloride with respect to the hydroxyl group of the phenol (reaction rate % with respect to one hydroxyl group) is 5 to 80%.
is preferable, more preferably 20 to 70%, still more preferably 30 to 60%. The integration rate is calculated by determining the sulfur atom content of the sulfonyl group by elemental analysis.

A resin obtained by condensing a substituted phenol represented by the general formula [II] with an aldehyde and an 0-naphthoquinonediazide sulfonic acid ester compound of the resin (hereinafter referred to as " The content of the sensitizing agent of the present invention is preferably 0.05 to 15% by weight,
Particularly preferred is 1 to 10% by weight.

The oil sensitizing agent of the present invention preferably has a weight average molecular IMW of 5. OX is in the range of 102 to 5.0X1Q3, more preferably 7. OX ranges from 102 to 3.0×103. Its number average molecule ffiMn is 3, OX 102
It is preferably in the range of 2.5 x 103, more preferably 4. OXIQ is in the range of 2 to 2.0×103.

The molecular weight of the oil sensitizing agent is measured by GPC (gel permeation chromatography). The number average molecular weight Mn and weight average molecular weight Mw were calculated by Morio Tsuge,
Written by Tatsuya Miyabayashi and Masayuki Tanaka, Journal of the Chemical Society of Japan, page 800~
Level the peaks of the oligomer region (connect the centers of the peaks and valleys) by the method described on page 805 (1972).
method.

The photosensitive composition of the present invention can contain a known alkali-soluble resin. Examples of alkali-soluble resins include novolac resins, such as phenol-formaldehyde resins, cresol-formaldehyde resins, phenol-modified xylene resins, and polyhydroxystyrene, but such alkali-soluble polymer compounds account for 40% by weight of the total composition. The following additions are also used.

The photosensitive composition of the present invention may contain, as a photosensitive component, an 0-naphthoquinonediazide compound in addition to the fat-sensitizing agent of the present invention. The O-naphthoquinonediazide compound is preferably an ester compound of O-naphthoquinonediazide sulfonic acid, a polycondensation resin of a phenol, and an aldehyde or ketone.

Examples of the phenols include phenol, 0-cresol, m-cresol, p-cresol, and 3.5-cresol.
Examples include monohydric phenols such as xylenol, carvacrol, and thymol, dihydric phenols such as catechol, resorcinol, and hydroquinone, and trihydric phenols such as pyrogallol and phloroglucin. Among these, monohydric phenols are preferred. Examples of the aldehyde include formaldehyde, benzaldehyde, acetaldehyde, crotonaldehyde, and furfural. Among these, formaldehyde and benzaldehyde are preferred. Examples of ketones used in cars include acetone and methyl ethyl ketone.

Specific examples of the polycondensation resin include phenol/formaldehyde resin, m-cresol/formaldehyde resin, m-, p-mixed cresol/formaldehyde resin, resorcinol/benzaldehyde resin, pyrogallol/acetone resin, and the like.

The condensation rate of O-naphthoquinonediazide sulfonic acid with respect to the OH group of the phenol in the O-naphthoquinonediazide compound (reaction rate with respect to one OH group) is 15 to 80%.
is preferable, and more preferably 20 to 45%.

The proportion of the 0-naphthoquinonediazide compound in the photosensitive crude product is preferably 5 to 60% by weight, particularly preferably 10 to 50% by weight.

In addition to the materials described above, the photosensitive composition of the present invention can contain other additives as necessary. Various low-molecular compounds such as phthalate esters, triphenyl phosphates, maleate esters are used as plasticizers, and surfactants such as fluorine-based surfactants and tyl cellulose polyalkylene ethers are used as coating properties improvers. Further, printout materials for forming visible images upon exposure to light may be mentioned. The printout material consists of a compound that generates acid or free radicals when exposed to light, and an organic dye that changes its color tone by interacting with it. O-naphthoquinonediazide-4-sulfonic acid halide described in Publication No. 50-36209, JP-A-5
Trihalomethyl-2-pyrone and trihalomethyl-triazine described in Publication No. 3-36223, JP-A No. 5
Ester compounds of O-naphthoquinonediazide-4-sulfonic acid chloride and phenols or anilines having an electron-withdrawing substituent, which are described in JP-A No. 5-6244; Examples include halomethyl-vinyl-oxadiazole compounds and diazonium salts.

Among these, halomethyl-vinyl-oxadiazole compounds are preferable, and in particular, halomethyl-vinyl-oxadiazole compounds are preferable, and in particular, the compounds described in JP-A No. 60-138539, which are formed by directly or via a vinyl group, are A 2-heromethyl-1,3,4-oxadiazole compound having the 5-position is more preferred.

Further, as the organic dye, for example, Victoria Pure Blue Bob ([Odugaya Chemical Co., Ltd.], Oil Blue #
603 [Orient Chemical], Patent Pure Blue [
Made by Sumitomo Mikuni Chemical], crystal violet, brilliant green, ethyl violet, methyl green,
Triphenylmethane type, diphenylmethane type represented by erythrosin B1 basic tsuksin, malachite green, oil red, m-cresol purple, rhodamine B1 auramine, 4-p-diethylaminophenylimino naphthoquinone, cyano-p-diethylaminophenyl acetanilide, etc. Examples include oxazine-based, xanthine-based, iminonaphthoquinone-based, azomethine-based, and anthraquinone-based dyes. Among these, triphenylmethane dyes are preferred.

Further, a sensitizer for improving sensitivity can also be added to the photosensitive composition of the present invention. Examples of the sensitizer include gallic acid derivatives as described in JP-A-57-118237 and 5-membered cyclic acid anhydrides as described in JP-A-52-80022, such as phthalanhydride. acids, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, maleic anhydride, succinic anhydride, virometic acid, itaconic acid, etc., and 6-membered cyclic acid anhydrides as described in JP-A-58-11932; Examples include glutaric anhydride and derivatives thereof. Among these, cyclic acid anhydrides are preferred, and 6-membered cyclic acid anhydrides are particularly preferred.

A positive-working photosensitive lithographic printing plate can be formed by dissolving the photosensitive composition of the present invention in a solvent that dissolves each of the above-mentioned components, and applying and drying the solution on the surface of a suitable support. Examples of solvents that can be used include cellosolves such as methyl cellosolve, methyl cellosolve acetate, ethyl cellosolve, and ethyl cellosolve acetate-1, dimethyl formamide, dimethyl sulfoxide, dioxane, acetone, cyclohexanone, trichloroethylene, and methyl ethyl ketone. These solvents may be used alone or in combination of two or more.

As the coating method, conventionally known methods such as spin coating, wire bar coating, dip coating, air knife coating, roll coating, blade coating, and curtain coating can be used.

Examples of the support on which the photosensitive layer using the photosensitive composition of the present invention is provided include metal plates such as aluminum, zinc, copper, and steel, and metal plates plated or vapor-deposited with chromium, zinc, copper, nickel, aluminum, iron, and the like. Examples include metal plates, paper, plastic films, paper coated with resin, paper covered with metal foil such as aluminum, and plastic films treated to make them hydrophilic. Among these, aluminum plates are preferred. When an aluminum plate is used as a support, it is preferably subjected to surface treatments such as graining, anodizing, and, if necessary, sealing. Known methods can be applied to these treatments.

Examples of the graining treatment include a mechanical method and an electrolytic etching method. Examples of mechanical methods include ball polishing, brush polishing, liquid honing, and puff polishing.

The various methods described above can be used alone or in combination depending on the composition of the aluminum material. preferred-
The method used is electrolytic etching.

Electrolytic etching is carried out in a bath containing one or a mixture of two or more inorganic acids such as phosphoric acid, sulfuric acid, hydrochloric acid, and nitric acid. After the graining treatment, if necessary, the material is neutralized by desmutting with an aqueous alkali or acid solution and washed with water.

The anodic oxidation treatment is performed by electrolyzing using an aluminum plate as an anode using a solution containing one or more of sulfuric acid, chromic acid, oxalic acid, phosphoric acid, malonic acid, etc. as an electrolytic solution. The amount of anodic oxide film formed was 1 to 50111 (1
/df is appropriate, preferably 10 to 40m(]/d
It is n2. The amount of anodized film can be determined, for example, by dissolving an aluminum plate in a phosphoric acid chromic acid solution (phosphoric acid 85% solution: 35 tL chromium oxide (■) = 209 dissolved in IIl water).
It is determined by dipping the plate in water to dissolve the oxide film and measuring the weight change before and after the film is dissolved.

Specific examples of the sealing treatment include boiling water treatment, steam treatment, sodium silicate treatment, and dichromate aqueous solution treatment. In addition, the aluminum plate support may be subjected to subbing treatment using an aqueous solution of a water-soluble polymer compound or a metal salt such as fluorinated zirconate.

In addition, in general, when contact baking a film original onto a photosensitive lithographic printing plate, the printing frame is vacuumed, and a method for improving this vacuum adhesion is also a positive-working photosensitive lithographic printing plate using the photosensitive composition of the present invention. Can be applied to printing plates. Methods for improving vacuum adhesion include mechanically creating unevenness on the surface of the photosensitive layer, scattering solid powder on the surface of the photosensitive layer,
A method of providing a matte layer on the surface of a photosensitive layer as described in JP-A-50-125805, and JP-A-55
Examples include a method of heat-sealing a solid powder onto the surface of a photosensitive layer, as described in Japanese Patent No. 12974.

A positive-working photosensitive lithographic printing plate to which the photosensitive composition of the present invention is applied can be used in the same manner as those conventionally used. For example, an ultra-high pressure mercury lamp is passed through a transparent film,
It is exposed to light using a light source such as a metal halide lamp, a xenon lamp, or a tungsten lamp, and then developed with an alkaline developer, leaving only the unexposed portions on the surface of the support, creating a positive relief image.

Examples of alkaline developers include sodium hydroxide,
Examples include aqueous solutions of alkali metal salts such as potassium hydroxide, sodium carbonate, potassium carbonate, sodium metasilicate, potassium metasilicate, sodium diphosphate, and sodium triphosphate.

The concentration of the alkali metal salt is preferably 0.1 to 10% by weight. In addition, an anionic surfactant, if necessary, is added to the developer.
Amphoteric surfactants and organic solvents such as alcohols can be added.

(Examples) Hereinafter, the present invention will be explained using Examples, but the present invention is not limited thereto.

Example 1 [Synthesis of exemplified binder resin (b-1)] 400 g of p-hydroxyaniline, 4T hydroquinone monomethyl ether], 41 g of acetone, and 360 g of pyridine were mixed and cooled from the outside using a cryogen until the internal temperature was 110 g. When the temperature dropped to 0.degree. C., 420 g of methacrylic acid chloride was added dropwise with stirring. The dropping rate was adjusted so that the reaction temperature was 0°C or lower, and after the dropwise addition was completed, the mixture was stirred at 0 to 3°C for about 2 hours.

Next, after stirring at 25°C for 2 hours, the reaction solution was concentrated to 1/3, poured into 1 (l) of dilute hydrochloric acid (IIH approximately 1.0), and the resulting precipitate was suction-filtered to give a white A solid was obtained. This white solid was dissolved in warm methanol 2y,
Furthermore, 21 parts of a 5% aqueous sodium carbonate solution was added, and the mixture was stirred at 40°C for 30 minutes.

This dark red solution was then poured into 5% aqueous hydrochloric acid solution to form a multi-can precipitate, which was filtered with suction and dried to give a pale pink solid. This was recrystallized from a mixed solvent of ethanol and water, and N-(4
-Hydroxyphenyl)acrylamide colorless needles 4
Obtained 50g.

The obtained N-(4-hydroxyphenyl)acrylamide 106.4i;l, acrylonitrile 32(1), ethyl acrylate 7.2Q, methyl methacrylate 73.20 and α,α'-azobisisobutyronitrile 6.56g was dissolved in 30Od of acetone/methanol (1:1) mixed solvent, replaced with nitrogen gas, and heated to 80'C.
The mixture was heated for 4 hours to obtain a polymer solution. This polymer solution was poured into three 5% HCffi aqueous solutions, and the resulting white precipitate was filtered and dried to obtain the exemplified binder resin (b-1).
Obtained 195g of.

Hereinafter, this resin will be referred to as [binder resin (b-1) J].

When the weight average molecular weight was measured, MW=3.5×10
It was 4.

[Synthesis of oil sensitizing agent] Novolac resin (weight average molecular weight M
W = 1300) 20! 1] was dissolved in 240 g of dioxane, 113 g of 0-naphthoquinonediazide-5-sulfonyl chloride was added, and after dissolving, 3
．． Add 5g of dissolved potassium carbonate aqueous solution dropwise to 40~
The condensation reaction was carried out at 50°C for 40 minutes.

After the reaction, dilute the reaction solution with diluted hydrochloric acid (500 g of water, 1.1 d of concentrated hydrochloric acid)
), and the precipitated resin was collected by filtration and dried.

In this way, p-tert-butylphenol
O-naphthoquinonediazide sulfonic acid ester compound 28o of benzaldehyde resin was obtained.

As a result of analysis, the condensation rate of OH groups was 50%.

Hereinafter, the ester compound will be referred to as "liposensitizing agent "■]".

An aluminum plate with a thickness of 0.24 mm was placed in a 5% sodium hydroxide aqueous solution at a temperature of 25°C and a current density of 60Δ/d.
Electrolytic etching treatment was performed under the conditions of 1ts treatment time = 30 seconds. Next, after desmutting with a 5% aqueous sodium hydroxide solution, anodizing was carried out in a sulfuric acid solution. The amount of anodic oxide film was measured by the method described above and was found to be 20 mg/dTA2. Next, it was immersed in a hot aqueous solution at 90°C for pore sealing treatment.

Subsequently, a photosensitive coating solution having the composition shown below was coated on the aluminum support using a spin coater and dried at 100° C. for 4 minutes to obtain a photosensitive lithographic printing plate (A).

(Photosensitive coating liquid composition) m-2ρ-mixed cresol [m-:p--6:4 (weight ratio)] and formaldehyde copolycondensate novolac resin and naphthoquinone-<1.2)-diazide-( 2) - Ester compound with 5-sulfonic acid chloride (condensation rate 25 mol%, weight average molecular weight Mw = 1700) 3.6
g. The above-mentioned binder resin (b-1) 4.8
! I+・Aforementioned oil sensitizing agent [I] 0.1
68! If Victoria Pure Blue BOH0,084
(1 (manufactured by Odugaya Kagaku ■, dye) ・2-trichloromethyl-5= [β-(2-benzofuryl) vinyl] 1,3,4-oxadiazole (described in JP-A-60-138539) Exemplary Compound (1)) 0.126 (toethyl cellosolve 67i12/methyl cellosolve 33.12) The coating weight after drying was approximately 24 ma/d12.

A step tablet (manufactured by Eastman Kodak Company, NO.
12. 21-step gray scale with densitometer of 0.15 each) and positive original film, and a 2kW metal halide lamp (manufactured by Iwasaki Electric Company) idle fin 2000
) as a light source, 8.0 mw/l:, 70 under the conditions of 2
Exposure for seconds, then apply developer for positive PS plate "5DR-1"
(manufactured by Konishiroku Photo Industry ■) at 25℃ using a 6-fold diluted solution.
When the plate was developed for 45 seconds, a lithographic printing plate in which the non-image areas were completely removed was obtained. When the sensitivity was measured, it was found that the third stage was completely developed (became clear) in the gray scale with the above-mentioned density difference of 0.15.21 steps.

In order to examine resistance to processing chemicals, durability against plate cleaner and washing oil, which are used as cleaning liquid to remove background stains that occur in non-image areas during printing, was investigated.

FD plate cleaner (manufactured by Toyo Ink Co., Ltd.)
, immersed in the stock solution of UV plate cleaner (manufactured by Moroboshi Ink Co., Ltd.) at air temperature for 12 hours, and similarly, UV plate cleaning liquid Best Cure (manufactured by Toka Shiki Kagaku ■ Co., Ltd.), U ■ Plate cleaning liquid Tsurfit (manufactured by Clarei Soprene Chemical Co., Ltd.) After being immersed in the stock solution for 10 minutes, it was washed with water, and the degree of erosion of the image area against the processing chemicals was measured by comparing it with the image area before immersion.

In addition, in order to examine ink receptivity, the number of waste sheets at the start of printing was measured. Plate wash gum liquid 5G was applied to the lithographic printing plate obtained by exposing and developing the positive original film.
W-1 (manufactured by Konishiroku Photo Industry Co., Ltd.) using a sponge,
After coloring and drying, use a sheet-fed printing machine (Hamadustar 90QC)
The gum removability immediately after the start of printing was determined by applying DX).

The results of sensitivity, processing chemical resistance, and ink receptivity are shown in Table 1.

Comparative Example 1 The photosensitive coating solution of Example 1 except for the above-mentioned sensitizing agent [I] was coated on the same support as in Example 1 and dried in the same manner as in Example 1 to obtain a photosensitive lithographic printing plate ( B) was obtained.
``The coating weight after drying was about 24 mg/df.

Using this photosensitive lithographic printing plate (B), sensitivity, processing chemical resistance, and ink receptivity were evaluated in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 2 From the photosensitive coating liquid of Example 1, the above-mentioned binder resin [
I], and instead use the same amount of the following binder resin [
II] was coated on the same support as in Example 1 and dried in the same manner as in Example 1 to obtain a photosensitive lithographic printing plate (C).
I got it.

- Binder resin [I] Phenol, m-cresol, copolycondensate novolak resin of p-cresol and formaldehyde (phenol, m-cresol: p-cresol = 20:30:50 (weight ratio), weight average molecular weight Mw = 6800) Using 4.8 g of the dried coated lithographic printing plate (C), the sensitivity, treatment chemical resistance, and ink receptivity were evaluated in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 3 The photosensitive coating solution of Comparative Example 2, except for the above-mentioned sensitizing agent [I], was applied to the same support as in Example 1 and dried in the same manner as in Example 1, followed by photosensitive planographic printing. Plate (D) was obtained.

The coating weight after drying was approximately 24 mQ/dv2.

Using this photosensitive lithographic printing plate (D), sensitivity, processing chemical resistance, and ink receptivity were evaluated in the same manner as in Example 1. The results are shown in Table 1.

As mentioned above, the sensitivity performed for Example 1 and Comparative Examples 1 to 3,
Table 1 summarizes the results of processing chemical resistance and ink receptivity.
become that way.

In Table 1, Mark A indicates slight erosion in the image area.

Mark B indicates erosion as above, and the grains of the support under the photosensitive layer are slightly exposed.

Mark C shows significant erosion as above, and the grains of the support below the photosensitive layer are completely exposed.

It means that.

In addition, ink receptivity is judged by the number of pieces of waste paper required from the start of printing until the gum is completely removed, the ink is sufficiently attached to the image area, and a complete print is obtained. Ta. The smaller the number, the better the gum removability and the better the ink receptivity.

From the results of the above Examples and Comparative Examples, the following is clear. That is, from the comparison between Example 1 and Comparative Example 1 and the comparison between Comparative Example 2 and Comparative Example 3, it was found that the oil sensitizing agent [I
] The effect of improving ink receptivity is significantly greater when the binder resins (b-1) of the present invention are used together than when the conventional binder resins of Comparative Examples 2 and 3 are used together.

In addition, from the comparison between Example 1 and Comparative Examples 1 to 3, it was found that the photosensitive lithographic printing plate (
A) is a photosensitive lithographic printing plate (B) to (D
) has superior treatment chemical resistance and ink receptivity.

Example 2 Synthesis of oil sensitizing agent [II] Novolac resin (weight average molecular weight m
Mw = 1500) 20a to dioxane 240v (1
0-naphthoquinonediazide-5-sulfonyl chloride (12.4) was added, and after dissolving, 25TI of water was added.
3.84 (l) of a potassium carbonate aqueous solution dissolved in I2 was added dropwise and the condensation reaction was carried out at 40 to 50°C for 40 minutes.
12) The precipitated resin was collected by filtration and dried.

In this way, 29 g of an 0-naphthoquinonediazide sulfonic acid ester compound of p-tert-octylphenol formaldehyde resin was obtained. As a result of analysis, the condensation rate of OH groups was 50%. Hereinafter, the ester compound will be referred to as "liposensitizing agent [■]".

From the photosensitive coating liquid of Example 1, the oil-sensitizing agent [I]0, 16
80, and instead the above-mentioned oil sensitizing agent [I] 0.08
4(l) was coated on the same support as in Example 1 and dried in the same manner as in Example 1 to obtain a photosensitive lithographic printing plate (E).

The coating weight after drying was approximately 24111(]/di2.

Using this photosensitive lithographic printing plate (E), sensitivity, processing chemical resistance, and ink receptivity were evaluated in the same manner as in Example 1. The results are shown in Table 2.

Example 3 From the photosensitive coating liquid of Example 1, the oil-sensitizing agent [I]o, 1
68g was removed, and instead, oil sensitizing agent [II] (p-
Novolak resin, which is a polycondensate of tert-butylphenol and formaldehyde, weight average molecular weight MW = 1
300) containing 0.252 g was coated on the same support as in Example 1 and dried to obtain a photosensitive lithographic printing plate (F).

The coating weight after drying was approximately 24 ma/d.2.

Using this photosensitive lithographic printing plate (F), the sensitivity, processing chemical resistance, and ink receptivity were evaluated in the same manner as in Example 1. The results are shown in Table 2.

Table 2 summarizes the results of sensitivity, processing chemical resistance, and ink receptivity for Examples 2 to 3.

The meanings of evaluation grades A to C in the table are the same as in Table 1.

Like the photosensitive lithographic printing plate (A>) of Example 1, the photosensitive lithographic printing plates (E) and (F) are excellent in both processing chemical resistance and ink receptivity.

(Effects of the Invention) As explained above, the photosensitive lithographic printing plate using the photosensitive composition of the present invention has excellent resistance to processing chemicals, especially resistance to plate cleaners and cleaning solutions used in UV ink printing. and has excellent ink receptivity.

Claims (1)

[Claims] (A) A polymer compound having a structural unit represented by the following general formula [I] and (B) a substituted phenol represented by the following general formula [II] and an aldehyde are condensed together. 1. A photosensitive composition comprising a resin and/or an o-naphthoquinonediazide sulfonic acid ester compound of the resin. General formula [I] ▲ Numerical formulas, chemical formulas, tables, etc. represents a halogen atom, an alkyl group, or an aryl group; R_4 represents a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group; Y represents an aromatic group that may have a substituent;
represents a divalent organic group, and n represents an integer of 0 to 5. ) General formula [II] ▲ Numerical formulas, chemical formulas, tables, etc. represent.)