JPH0658531B2 - Photosensitive lithographic printing plate - Google Patents

Description

TECHNICAL FIELD The present invention relates to a positive-working photosensitive lithographic printing plate, and more specifically, it relates to a photosensitive resin comprising a combination of an o-naphthoquinone diazide sulfonic acid ester and a resin having a specific structural unit. It relates to a positive-working photosensitive lithographic printing plate having a layer.

[Conventional technology]

A positive-working photosensitive lithographic printing plate is generally one in which an ink-receptive photosensitive layer which is solubilized by exposure is formed on a hydrophilic support. When the photosensitive layer is imagewise exposed and developed, the non-image area is removed while leaving the image area, so that an image is formed. In printing, the difference in properties that the image area is lipophilic and the non-image area is hydrophilic is used.

Generally, a lithographic printing plate is required to have printing durability, chemical resistance, development latitude, ink acceptability, sensitivity, etc., but particularly in the case of positive type, good chemical resistance, printing durability, development latitude Is desired. Here, chemical resistance means various chemicals used during printing, such as isopropyl alcohol,
Appropriate for ink, surface conditioning solution, plate cleaner, etc.

Although an o-naphthoquinonediazide compound is widely used for the photosensitive layer, since it is not a high molecular compound itself, it is possible to improve mechanical strength by mixing it with a novolac resin or a condensation reaction. Has been. As an example of a resin-bound o-naphthoquinonediazide compound, Japanese Examined Patent Publication (Kokoku) No. 43-28403 discloses an o-naphthoquinonediazide sulfonic acid ester which is a polycondensation resin of pyrogallol and acetone. However, although this shows relatively good performance, it is a normal novolac resin as a binder,
For example, when m-cresol novolac resin is used, especially when UV ink is used, the printing durability is insufficient.

Therefore, in order to further improve the above-mentioned various properties such as printing durability and chemical resistance, a photosensitive composition containing various photoconductors and binders has been proposed.

The photosensitive composition disclosed in JP-A-55-76346 includes a polyhydroxyphenyl compound obtained by cocondensation polymerization of resorcinol or a derivative thereof, pyrogallol and acetone, and an o-quinonediazide compound having a halogenosulfonyl group. It contains a photosensitive resin obtained by condensing and an alkali-soluble resin such as phenol / formaldehyde resin as a binder. In addition, Japanese Patent Publication No. 56-54621
The photosensitive composition disclosed in US Pat. No. 6,096,086 contains an o-quinonediazide compound photoconductor and a binder of a resin obtained by cocondensing phenol, m-, p-mixed cresol and an aldehyde. However, these photosensitive compositions have the drawback that the so-called novolac resin is used as a binder, so that the film strength of the photosensitive layer in the image area is low and the printing durability is poor.

Therefore, as a method of improving printing durability, after exposure and development,
Method of heat treatment at high temperature (called burning treatment)
Is commonly used. However, when the burninz treatment is performed, the monomer component of the resin adheres to the non-image area or the like from the photosensitive layer of the image area during heating, which causes a problem that scumming is likely to occur during printing.

On the other hand, the photosensitive composition disclosed in Japanese Examined Patent Publication No.
-A photosensitizer comprising a naphthoquinone diazide sulfonic acid derivative and the following general formula (In the formula, R ₁ and R ₂ are a hydrogen atom, an alkyl group or a carboxylic acid group, R ₃ is a hydrogen atom, a halogen atom or an alkyl group, and R ₄ is a hydrogen atom, an alkyl group, a phenyl group or an aralkyl group. , X is a divalent organic group connecting a nitrogen atom and an aromatic ring carbon atom, n is 0 or 1, and Y is a phenylene group which may have a substituent or a naphthylene group which may have a substituent. A binder made of a polymer compound having a structural unit represented by the formula (1). Since this photosensitive composition uses a polymer compound having the above structural unit instead of a novolac resin as a binder, it has good photosensitive layer film strength and printing durability.

[Problems to be solved by the invention]

However, a positive-working photosensitive lithographic printing plate having a photosensitive layer made of a photosensitive composition of JP-B-52-28401 shows a relatively good printing durability and chemical resistance in ordinary printing, It proved to be insufficient in UV printing. In addition, the disadvantage that the development latitude was narrow was also recognized. Here, UV printing means ink containing a UV absorber (U
V ink) refers to printing using. It was found that the reason why it is not suitable for UV printing is that the chemical resistance of the photosensitive layer is low with respect to the inks and chemicals used for UV printing.

Therefore, an object of the present invention is to provide a positive-working photosensitive lithographic printing plate having extremely good chemical resistance and capable of performing UV ink printing without performing a burning treatment and having excellent printing durability.

Still another object is to provide a positive-working photosensitive lithographic printing plate which does not cause scumming and has a wide development latitude.

[Means for solving problems]

As a result of intensive investigations by the present inventors regarding the drawbacks of the above-mentioned photosensitive composition, as a photosensitizer, a derivative of o-naphthoquinonediazide sulfonic acid was identified as a low molecular ester, amide or azide, phenol or cresol. It has been discovered that chemical resistance and printing durability in UV printing are inferior because it is produced from a monohydric phenol novolac resin such as xylenol. Furthermore, as a result of various studies on compounds that should form derivatives of o-naphthoquinonediazide sulfonic acid, as a result of adding o-naphthoquinone diazide sulfonic acid ester to be combined with a polymer compound binder having a specific structural unit, polyhydric phenol and aldehyde or It has been discovered that a positive photosensitive lithographic printing plate having excellent chemical resistance and printing durability in UV printing can be obtained by using a product in which a polycondensation resin with a ketone is bonded, and the present invention was conceived.

That is, the positive-working photosensitive lithographic printing plate of the present invention comprises (A) an o-naphthoquinonediazide sulfonic acid ester of a polycondensation resin of a polyhydric phenol and an aldehyde or a ketone, and (B) the following general formula [I]. (In the formula, R ₁ and R ₂ are a hydrogen atom, a halogen atom, an alkyl group, an aryl group or a carboxylic acid group, R ₃ is a hydrogen atom, a halogen atom, an alkyl group or an aryl group, and R ₄ is a hydrogen atom. , An alkyl group, an aryl group or an aralkyl group, Y is an aromatic group which may have a substituent, and X is a divalent organic group connecting a nitrogen atom and a carbon atom of the aromatic group. And n is an integer of 0 to 5.) is provided on a support with a photosensitive layer containing a polymer compound having a structural unit represented by

As the polyhydric phenol used in the o-naphthoquinonediazide sulfonate of the present invention, catechol, (methyl) resorcin, hydroquinone, pyrogallol, phloroglucin and the like are preferable, and pyrogallol is more preferable. As the ketone or aldehyde, acetone, formaldehyde, acetaldehyde, benzaldehyde,
Crotonaldehyde and the like are preferable, and acetone is more preferable. It is also possible to use two or more polyhydric phenols in combination.

A polycondensation resin of a polyhydric phenol and a ketone or an aldehyde can be synthesized by a known method. First, a polyhydric phenol and a ketone or an aldehyde are dissolved by adding a suitable solvent, if necessary, and caused to undergo a polycondensation reaction in the presence of a suitable acid such as hydrochloric acid, phosphorus oxychloride and oxalic acid. A condensate is obtained. Suitable solvents include, for example, dioxane, methanol, ethanol, tetrahydrofuran, water or mixtures thereof.

As polycondensation conditions, it is preferable to carry out the polycondensation reaction at a higher temperature from the initial stage of polymerization than in the known method. For example, hydrochloric acid,
Add acid catalysts such as sulfuric acid, oxalic acid, phosphorus oxychloride, etc. to the mixture of polyhydric phenols and ketones or aldehydes (containing a suitable solvent if necessary) and at the same time bring them to the steady state of reflux. Is preferred.

The molecular weight of the polyhydric phenol polymer compound obtained by these methods is determined by gel permeation chromatography (hereinafter abbreviated as GPC) method using polystyrene as a standard. The number average molecular weight _Mn of the polyhydric phenol polymer compound is preferably 300 to 2000, and the weight average molecular weight _Mw thereof is preferably 500 to 4000. More preferably, M _n is 400 to 1500 and M _w is 700 to 35.
00.

Preferred examples of polycondensates of these polyhydric phenols satisfying both the developability and the processing chemical resistance are resorcin benzaldehyde resin, methyl resorcin benzaldehyde resin, pyrogal-acetone resin and the like in the above molecular weight range, and more preferable. Is Pyrogall-acetone resin.

The o-naphthoquinonediazide sulfonic acid ester having a polycondensation rate of these polyhydric phenols can be obtained by the following synthetic method. First, a polycondensation product of polyhydric phenols is dissolved in an appropriate solvent such as dioxane, and o-naphthoquinonediazide sulfonyl chloride is added thereto, and then alkali carbonate is added dropwise to the equivalent point for esterification.

The substantial condensation rate (the ratio of o-naphthoquinone diazide sulfonyl chloride to one OH group of polyhydric phenol) of this esterified product is preferably 10 to 50 mol%, more preferably 10 to 40 mol%, and further preferably 15
Is about 35 mol%. If it exceeds 50 mol%, the erasability by the developer will be poor regardless of the molecular weight, and 10 mol%
When it is less than the above range, the over-developing property becomes poor and the image area is apt to be lost.

The molecular weight of this esterified product varies slightly depending on the substantial condensation rate of OH groups, but in general, the esterified product having a substantial condensation rate of OH groups of 10 mol% to 50 mol% has an M _n of 500 to.
3600, _Mw is preferably 700 to 5800, more preferably _Mn is 600 to 2400 and _Mw is 90.
It is 0 to 4000. More preferably, M _n is 700 to 2
At 100, M _w is 1000 to 3600.

When an o-naphthoquinonediazide sulfonic acid ester of a polycondensation product of polyhydric phenols having M _n of more than 3600 and M _{w of} more than 5800 is used, underdeveloping property becomes poor and scumming easily occurs. Moreover, the erasability becomes poor.

On the other hand, when an o-naphthoquinone diazide sulfonic acid ester of a polycondensation product of polyhydric phenols having M _n of less than 500 and M _w of less than 700 is used, over-developing property becomes poor, resulting in loss of image area. , Or the chemical resistance of the image area tends to deteriorate, which is not preferable.

The content of the esterified product in the photosensitive layer varies depending on the kind thereof, but is generally preferably 5 to 40% by weight, more preferably 10 to 30% by weight.

In addition, the following general formula [I] (In the formula, R ₁ and R ₂ are a hydrogen atom, a halogen atom, an alkyl group, an aryl group or a carboxylic acid group, R ₃ is a hydrogen atom, a halogen atom, an alkyl group or an aryl group, and R ₄ is a hydrogen atom. , An alkyl group, an aryl group or an aralkyl group, Y is an aromatic group which may have a substituent, and X is a divalent organic group connecting a nitrogen atom and a carbon atom of the aromatic group. And n is an integer of 0 to 5.) The polymer compound having a structural unit represented by the formula (1) may be a homopolymer having a repeating structure of only the above structural unit. A copolymer having two or more kinds of monomer units may be used.

In the above structural unit, R ₁ and R ₂ are preferably a hydrogen atom, an alkyl group such as a methyl group or an ethyl group, or a carboxylic acid group, and more preferably a hydrogen atom. R ₃ 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, 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 as the substituent, an alkyl such as a methyl group or an ethyl group, a halogen atom such as bromine or chlorine, a carboxylic acid group, a methoxy group or an ethoxy group is used. Alkoxy groups such as groups, hydroxyl groups, sulfonic acid groups,
There are cyano group, nitro group, acyl group and the like. More preferably, Y is an unsubstituted or phenylene group having a methyl group or a naphthylene group. X is a divalent organic group connecting a nitrogen atom and an aromatic carbon, preferably an alkylene group, and n is 0 to 5, preferably 0 to 3, and more preferably 0.

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

Among the above-mentioned monomers, (meth) acrylic acid, esters of aliphatic monocarboxylic acid, and nitriles are preferable as those used in combination with the structural unit [I] because they show excellent performance in a comprehensive view. More preferred are methacrylic acid, methyl methacrylate, acrylonitrile, ethyl acrylate and the like.

These monomers may be bound to the polymer compound in either a block or random state.

Representative examples of the polymer compound (B) of the present invention will be given. In the compounds exemplified below, M _w is a weight average molecular weight,
M _n represents the number average molecular weight, and s, k, l, m and n each represent mol% of the structural unit.

(R ₁ and R ₂ are hydrogen atom, alkyl group, halogen group) (R _{1 to} R ₃ are hydrogen atom, alkyl group, halogen atom) (X is an alkyl group, a halogen atom) (R ₁ is a hydrogen atom, an alkyl group, a halogen atom) (X is an alkyl group, a halogen atom) (R ₁ is a hydrogen atom, an alkyl group, a halogen atom) (R _{1 to} R ₃ are hydrogen atom, alkyl group, halogen atom) (R _{1 to} R ₄ are hydrogen atom, alkyl group, halogen atom) (R _{1 to} R ₅ are hydrogen atom, alkyl group, halogen atom) (R _{1 to} R ₅ are a hydrogen atom, an alkyl group, a halogen atom) Further, specifically, The polymer compound (B) of the present invention can be synthesized as follows. First, α ・ β-unsaturated acid chlorides,
Alternatively, the α / β-unsaturated acid anhydride is reacted with a primary or secondary amine having a phenolic hydroxyl group by using a basic catalyst, if necessary, and is represented by the general formula [I]. A monomer having a structural unit is synthesized. Then, the monomer can be homopolymerized by a conventional method, or the monomer and at least one other vinyl-based monomer can be copolymerized to obtain the polymer compound of the present invention. . At this time, the molecular weight of the polymer compound (B) and the molar ratio of each structural unit can be set in a wide range by variously changing the charged molar ratio of each monomer and the polymerization conditions. But,
In order to effectively provide the intended use of the present invention, it is preferable that the molecular weight is 5,000 to 100,000 and the molar content of the structural unit represented by the general formula [I] is at least 10 mol%.

A known alkali-soluble polymer compound can be contained in the composition forming the photosensitive layer of the present invention. As an alkali-soluble polymer compound, novolac resin, such as phenol-formaldehyde resin, cresol
Formaldehyde resin and phenol-modified xylene resin,
Polyhydroxystyrene and the like can be mentioned, but such an alkali-soluble polymer compound accounts for 40% by weight of the total composition.
It is used in the following addition amounts.

The positive-working photosensitive lithographic printing plate generally further contains an exposure visible image-imparting agent and a dye. It is common to use a substance that generates an acid upon exposure as the visible image-imparting agent, and a compound that forms a salt with this acid as the dye.

The compound which generates an acid upon exposure is represented by the following general formula II
Alternatively, a trihaloalkyl compound represented by III or a diazonium salt compound is preferable.

(However, Xa is a trihaloalkyl group having 1 to 3 carbon atoms, W is N or P, Z is O, S or Se, and Y cyclizes W and Z and has a chromophore. . a _{^{group) Ar-N 2 + X -}} . ... III (Ar is an aryl group, X is a counterion of an inorganic compound) specific examples of the trihaloalkyl compound of formula II,
For example, there are compounds represented by the following general formulas IIa, IIb, and IIc.

(However, A is a substituted or unsubstituted aryl group or a heterocyclic group, B is hydrogen or a methyl group, and n is 0 to
It is an integer of 2. ) The amount of the exposed image-imparting agent added is 0.0 in the total composition of the photosensitive layer.
It is preferably from 1 to 20% by weight, more preferably 0.
It is 1 to 10% by weight.

On the other hand, as the pigment, any compound can be generally used as long as it is a compound which forms a salt with an acid, and examples thereof include triphenylmethane dyes, cyanine dyes, diazo dyes and styryl dyes.

Specifically, Victoria Pure Blue BO, ethyl violet, crystal violet, brilliant green, basic fuchsin, eosin, phenolphthalein, xylenol blue, congo red, malachite green, oil blue # 603, oil pink # 3.
12, cresol red, auramine, 4-p-diethylaminophenyliminonaphthoquinone, leucomalachite green, leucocrystal violet and the like can be mentioned. The amount of dye added is about 0.01 to 1 of the total composition of the photosensitive layer.
0 wt% is preferable, more preferably 0.05 to 8 wt%
Is.

In addition to the photosensitive layer composition of the positive-working photosensitive lithographic printing plate of the present invention, various additives can be added depending on the purpose. For example, a surfactant to improve coatability,
Various sensitizers for improving the sensitivity, plasticizers for improving the physical properties of the coating film, and various additives having a hydrophobic group such as p-octylphenol-for improving the ink receptivity of the image. Modified novolac resins such as formalin novolac resin, pt-butylphenol-formalin novolac resin, pt-butylphenol benzaldehyde resin, and rosin-modified novolac resin, o-naphthoquinone diazide sulfonic acid ester of these modified novolac resins (of OH group) Esterification rate of 20 to 70 mol%) and the like can be added. The content of these additives varies depending on the type and purpose, but is generally 0.01 to 20% by weight, preferably 0.05 to 10% by weight, based on the total composition of the photosensitive layer.

The photosensitive layer composition is supported by being dissolved in various solvents, for example, cellosolves such as methyl (ethyl) cellosolve and methyl (ethyl) cellosolve acetate, dimethylformamide, dimethyl sulfoxide, dioxane, acetone, cyclohexanone, trichloroethylene and the like. It is formed by applying it on the body and drying it.

The photosensitive layer of the positive-working photosensitive lithographic printing plate of the present invention is generally 0.5 to 3.0 g / solid as a solid content, though it varies depending on the use.
It is preferably formed to have m ² .

An aluminum plate is preferred as the support used in the positive photosensitive lithographic printing plate of the present invention. The aluminum plate is preferably subjected to surface treatment such as graining treatment, anodic oxidation treatment and, if necessary, sealing treatment. These treatments can be performed by a known method.

Examples of the graining treatment method include a mechanical method and an electrolytic method. Examples of mechanical methods include a ball polishing method, a brush polishing method, a liquid honing polishing method, and a buff polishing method. The above methods may be used alone or in combination depending on the composition of the aluminum material. The electrolytic etching method is preferred.

The electrolytic etching is performed by immersing the aluminum plate in a bath containing one or more inorganic acids such as phosphoric acid, sulfuric acid, hydrochloric acid and nitric acid. After the graining treatment, if necessary, desmut treatment is performed with an aqueous solution of alkali or acid to neutralize and washing with water.

The anodizing treatment is carried out by using a solution containing one or more of sulfuric acid, chromic acid, oxalic acid, phosphoric acid, malonic acid and the like as an electrolytic solution and electrolyzing with an aluminum plate as an anode. The amount of anodized film formed is 1 to 50 mg / dm ²
Is suitable, and preferably 10 to 40 mg / dm ² .
Here, the amount of the anodic oxide film is, for example, an aluminum liquid immersed in a phosphoric acid chromic acid solution (35% of 85% phosphoric acid aqueous solution and 20 g of chromium (VI) oxide dissolved in 1 water) to form the oxide film. It can be determined by dissolving and measuring the weight change of the plate before and after the film is dissolved.

Examples of the sealing treatment include boiling water treatment, steam treatment, sodium silicate treatment, and dichromate aqueous solution treatment. In addition to this, with respect to the aluminum support, a water-soluble polymer compound,
The subbing treatment can be performed with an aqueous solution of a metal salt such as fluorinated zirconic acid.

The positive type photosensitive lithographic printing plate thus obtained can be used by a known method. Typically, a positive-type film is adhered to the photosensitive printing plate, an ultra-high pressure mercury lamp,
Exposure with a metal halide lamp, etc., sodium metasilicate,
Development is carried out with an aqueous alkaline solution such as potassium metasilicate, sodium phosphate, caustic soda, etc. to obtain a printing plate.

The lithographic printing plate thus produced can be used in a sheet-fed printing press.

〔Example〕

 The invention will be explained in more detail by the following examples.

First, examples of synthesizing the photoconductor and the binder used in the present invention are shown below.

[Synthesis of photoconductor]

Synthetic Example 1 100 g of pyrogallol and 700 g of acetone were put into a three-headed Kolben set in a water bath, nitrogen gas was blown therein to carry out nitrogen substitution, and then 10 g of phosphorus oxychloride was put in to carry out a polycondensation reaction. . Reaction temperature is 20
The temperature was kept at ℃ and the reaction was continued all day and night. After the reaction is complete, water 30
The product was gradually added while vigorously stirring to precipitate the polycondensate.

The precipitated resin was separated and washed with water until it became almost neutral. The precipitate was dried below 40 ° C. Thus, 100 g of a light brown resin was obtained.

GPC [Hitachi 635 type, column
Polystyrene was used as a standard according to Shodex A804, A803, A302 in series].
The calculation of M _n and M _w is carried out by the method described in Tsuge et al., Journal of the Chemical Society of Japan, page 1972 (April issue), page 800, by smoothing the peak of the oligomer region (connecting the peak and valley centers of the peak). went. As a result, M _n is 2000 and M _w is 3400.
Met.

Next, 60 g of this resin was dissolved in 720 m of dioxane,
70 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride was added, 60 g of a 13 wt% potassium carbonate aqueous solution was added dropwise after dissolution, and a condensation reaction was carried out at 40 to 50 ° C. for about 1 hour. A large amount of dilute hydrochloric acid water (concentrated hydrochloric acid 13
m, water 3), and the precipitated resin was separated and dried. Thus, 56 g of a yellow powder resin of 1,2-naphthoquinonediazide-5-sulfonic acid ester of pyrogallol-acetone resin was obtained. As a result of the analysis, it was found that the condensation rate of OH groups was 20%. When the molecular weight of this ester was measured by the above GPC, M _n was 2300 and M _w was 3030.

Synthesis Example 2 87.2 g of resorcin and 260 g of methanol were put into a three-headed corben set in a water bath, and after resorcin was dissolved, 78 g of benzaldehyde was added, and 0.5 m of concentrated hydrochloric acid was added, and after about 10 minutes. A heating control was performed so that methanol was refluxed. About 2 hours after the reflux started, the reaction solution was dropped into about 4 water,
Separated, washed with water and dried at room temperature. In this way, 112 g of a light brown powdery resin was obtained. The molecular weight was measured by GPC in the same manner as in Synthesis Example 1, and as a result, M _n was 78.
0 and M _w were 1320.

Next, 66 g of this resin was dissolved in 720 m of dioxane,
After 90 g of o-naphthoquinonediazide-5-sulfonyl chloride was added and dissolved, 213 g of a 13 wt% potassium carbonate aqueous solution was added dropwise, and a condensation reaction was carried out at 40 to 50 ° C. for about 1 hour. Then, the reaction solution was poured into a large amount of dilute hydrochloric acid in the same manner as in Synthesis Example 1 and separated to obtain 132 g of an o-naphthoquinone diazide sulfonic acid ester resin of resorcinol-benzaldehyde resin. As a result of analysis, the condensation rate of OH groups is 23%
Met. As a result of molecular weight measurement by GPC, M _n is 15
50 and _Mw were 1780.

Comparative Synthesis Example 1 216 g of m-cresol, 60 g of 37% aqueous formaldehyde solution and 2.5 g of oxalic acid were put into a three-headed Kolben set in an oil bath, and the temperature was raised with stirring. Vigorous foaming occurred at around 90 ° C, and the temperature inside the Kolben was raised to 105 ° C by temporarily cooling and then raising the temperature again.

After reacting for about 3 hours, the temperature was further raised to 175 ° C. and water was distilled off. After 2 hours, the temperature was raised to 200 ° C and 100
The pressure was reduced to mmHg, and the residual monomer was distilled off. After 1 hour, the reaction was stopped, and the reaction product was poured onto a Teflon pad and solidified. As a result of measuring the molecular weight of this resin by GPC,
_Mn was 500 and _Mw was 1500.

Next, 60 g of this resin was dissolved in 720 m of dioxane,
100 g of o-naphthoquinonediazide-5-sulfonyl chloride was added, and after dissolution, 115 g of a 13 wt% potassium carbonate aqueous solution was added dropwise, and a condensation reaction was carried out at 40 to 50 ° C. for about 1 hour. After that, a large amount of dilute hydrochloric acid (concentrated hydrochloric acid 13 m
, 12), and the precipitated resin was separated and dried. In this way, 105 g of o-naphthoquinonediazide sulfonic acid ester resin of m-cresol-formaldehyde resin was obtained. As a result of the analysis, the condensation rate of OH groups was 30%.

As a result of calculating M _n and M _{w by} the above method, M _n is 85.
0 and M _w were 1750.

[Synthesis of binder]

Synthesis Example 1 Synthesis of polymer compound (b-1) p-hydroxyaniline 400 g, hydroquinone monomethyl ether 4 g, acetone 4 and pyridine 36
Mix 0 g, cool from the outside with a freezing agent, and keep the internal temperature-
Methacrylic acid chloride 420 when the temperature drops to 10 ° C
g was added dropwise with stirring. The dropping rate was adjusted so that the reaction temperature was 0 ° C. or lower, and after completion of the dropping, the mixture was stirred at 0 to 3 ° C. for about 2 hours. Then, after stirring at 25 ° C for 2 hours, the reaction solution was concentrated to 1/3 position, poured into diluted hydrochloric acid (pH about 1.0) 10, and the resulting precipitate was suctioned to obtain a white solid. It was
The white solid was dissolved in warmed methanol 2, 2% of 5% aqueous sodium carbonate solution was added, and the mixture was stirred at 40 ° C. for 30 minutes. Then, this dark red solution was poured into 5% aqueous hydrochloric acid solution 8 to form a large amount of precipitate, which was sucked and dried to obtain a pale pink solid. This is recrystallized from a mixed solvent of ethanol and water to give a melting point of 155-155.
450 g of colorless needle crystals of p-hydroxymethacrylanilide at 156 ° C. were obtained.

P-Hydroxymethacrylanilide thus obtained
(HyPMA) 53.2 g, acrylonitrile (AN) 15.9
g, methyl methacrylate (MMA) 40.0 g and α ·
0.82 g of α′-azobisisobutyronitrile was dissolved in 190 m of a mixed solvent of acetone: ethanol (1: 2), the atmosphere was replaced with nitrogen gas, and the mixture was heated at 65 ° C. for 4 hours to obtain a polymer solution. . The polymer solution was poured into a 3% 5% aqueous HCl solution, the white precipitate formed was filtered, dried and
70 g of a white polymer was obtained. The molecular weight of the obtained polymer is G
When measured by PC, M _n was 3200 and M _w was 22000.

Synthesis Example 2 Synthesis of Polymer Compound (b-2) The p-hydroxymethacrylanilide (HyP) obtained in Synthesis Example 1 was synthesized.
MA) 50.0 g, acrylonitrile (AN) 15.0 g, methyl acrylate (EA) 42.0 g and α.α'-azobisisobutyronitrile 0.30 g mixed solvent of acetone: ethanol (1: 2). After dissolving in 190 m and purging with nitrogen gas, it was heated at 65 ° C. for 4 hours to obtain a polymer solution. Pour the polymer solution into the 3% 5% HCl aqueous solution,
The white precipitate formed was passed and dried to give the white polymer 6
5 g was obtained. When the molecular weight was measured by GPC, M _n was 28.
00 and M _w were 60,000.

Synthesis Example 3 Synthesis of polymer compound of (e-2) 400 g of m-hydroxy-p-cyanoaniline, 4 g of hydroquinone monomethyl ether, acetone 4 and 360 g of pyridine were mixed, cooled from the outside with a cryogen, and the internal temperature was adjusted. When the temperature dropped to −10 ° C., 420 g of methacrylic acid chloride was added dropwise with stirring. Hereinafter, Synthesis Example 1
In the same manner as described above, 350 g of m-hydroxy-p-cyanomethacrylanilide was obtained.

Thus obtained m-hydroxy-p-cyanomethacrylanilide 76.8 g (0.38 mol), ethyl methacrylate 68.4 g (0.60 mol) and acrylic acid 1.44 g
(0.02 mol) and 0.7 g of α · α′-azobisisobutyronitrile, along with acetone: ethanol (1:
It was dissolved in 300 m of the mixed solvent of 2) and replaced with nitrogen gas, and then heated at 65 ° C. for 4 hours to obtain a polymer solution. The polymer solution was poured into a 5% HCl aqueous solution of 3, and the white precipitate formed was filtered and dried to obtain 75 g of a white polymer. When the molecular weight was measured by GPC, M _n was 4700, M _w
Was 33000.

Synthesis Example 4 Synthesis of Polymer Compound of (g-1) 227 g of 5-amino-α-naphthol, 1 g of hydroquinone monomethyl ether and pyridine 2 were mixed,
It was cooled to -10 ° C using a freezing agent, and 110 g of methacrylic acid chloride was added dropwise with stirring. 0 ~ 3 ℃ after dropping
And stirred for 2 hours. Then, after stirring at 25 ° C. for 2 hours, the reaction solution was poured into 20 ice water to generate a precipitate, which was passed through, washed with water and dried. The obtained solid was added to a mixed solution (1: 1) 2 of methanol and a 5% sodium carbonate aqueous solution, stirred at 40 ° C for 30 minutes, and then poured into 5% hydrochloric acid 4 to generate a large amount of precipitate. . After suctioning, this was recrystallized with ethanol to obtain 210 g of N- (5-hydroxy-α-naphthyl) methacrylamide having a melting point of 223 to 224 ° C.

68 g (0.3 mol) of N- (5-hydroxy-α-naphthyl) methacrylamide thus obtained were mixed with 10 g (0.1 mol) of 2-hydroxyethyl methacrylate and 30 g (0.3 mol) of methyl methacrylate. , Acrylonitrile (15.9 g, 0.3 mol) and α · α′-azobisisobutyronitrile (0.50 g) were dissolved in 200 m of a mixed solvent of acetone: ethanol (1: 2). The obtained solution was heated at 65 ° C. for 8 hours in a sealed tube whose atmosphere was replaced with nitrogen gas to obtain a copolymer solution. After diluting this copolymer solution with 100 m of methanol, it was poured into water and the precipitate formed was filtered and dried to obtain 70 g of a white polymer. G
When the molecular weight was measured by PC, M _n was 9100 and M _w was 48.
It was 000.

Comparative Synthesis Example 1 The reaction was performed under the same conditions except that 2-hydroxyethyl methacrylate was used in place of p-hydroxymethacrylanilide in Synthesis Example 1. When the molecular weight of the obtained polymer was measured by GPC, M _n was 2300 and M _w was 1
It was 5000.

Comparative Synthesis Example 2 90 g of m-cresol, 56 g of p-cresol, 54 g of phenol, 105 g of 37% aqueous formaldehyde solution and 2.5 g of oxalic acid were charged into a three-headed Kolben set in an oil bath, and the temperature was raised with stirring. After vigorous foaming at around 90 ° C., the mixture was temporarily cooled, then the temperature was raised again, and the internal temperature was adjusted to 105 ° C. After reacting for about 3 hours, the temperature was raised to 175 ° C. again, and water was distilled off. After 2 hours, the temperature was raised to 200 ° C. and the pressure was reduced to 100 mmHg to distill off the residual monomer. After 10 minutes, the reaction was stopped, and the reaction product was poured into a Teflon pad and solidified. The molecular weight of this resin was measured by GPC using polystyrene as a standard. The calculation of M _n and M _w was performed in the same manner as described above. As a result, M _n is 1350 and M _w
Was 6750.

Example 1 An aluminum plate having a thickness of 0.24 mm was degreased in a 5% sodium hydroxide aqueous solution, and then, in a 0.3 molar nitric acid aqueous solution,
The electrolytic etching treatment was performed under conditions of a temperature of 30 ° C., a current density of 50 A / dm ² , and a treatment time of 30 seconds. Then 5%
Desmutting treatment was carried out with an aqueous sodium hydroxide solution, and then anodizing treatment was carried out in a sulfuric acid solution. The amount of anodized film was measured by the above-mentioned method and was found to be 20 mg / dm ² . Next, it was immersed in a hot aqueous solution at 90 ° C. for sealing treatment.

The aluminum coating thus obtained was coated with a photosensitive coating solution having the following composition using a spin coater,
It was dried at ℃ for 4 minutes to obtain a photosensitive lithographic printing plate having a film thickness of 24 mg / dm ² .

Photosensitive liquid 1 The photosensitive lithographic printing plate thus obtained was used with a 3 kW ultra-high pressure mercury lamp for 60
Exposure is carried out for 30 seconds from a distance of cm, and then development processing is carried out at 25 ° C. for 45 seconds using a 7-fold diluted solution of PS plate positive developing solution “SDP-1” (manufactured by Konishi Rokusha Kogyo Co., Ltd.). went. The sensitivity and chemical resistance of the obtained lithographic printing plate were measured.

Example 2 A photosensitive coating solution (photosensitive solution 2) was prepared in the same manner as in Example 1 except that the binder in Synthesis Example 2 was used in place of the binder in Synthesis Example 1, and the same was used as in Example 1. A lithographic printing plate was prepared by the method described in 1. and the same measurement was performed.

Comparative Example 1 A photosensitive coating solution (Comparative Photosensitive Solution 1) was prepared in the same manner as in Example 1 except that the binder of Comparative Synthetic Example 2 was used in place of the binder of Synthetic Example 1, and Example 1 was prepared using this.
A lithographic printing plate was prepared in the same manner as in 1. and the same measurement was performed.

Table 1 shows the measurement results of Example 1, Example 2 and Comparative Example 1.

It can be seen from Table 1 that the printing plate of the present invention has extremely good chemical resistance (suitability for UV-containing ink).

Example 3 The lithographic printing plate of Example 1 was tested for printability, developability and printing durability.

The printability was evaluated by applying a lithographic printing plate to a sheet-fed offset printing machine, printing on a high-quality paper, and examining the presence or absence of background stain. As a result of printing, no background stain was generated at all, and a good printed matter could be obtained. This shows that the printability is excellent.

In order to evaluate the developability, the photosensitive lithographic printing plate was forcibly deteriorated at a temperature of 40 ° C. and a humidity of 80% for 7 days, and then exposed, and then exposed to 4 m ² / SDP-1 fatigue developer (diluted 7 times). )
It was developed and printed. As a result, no dirt is generated,
Good prints were obtained. This shows that the developability is excellent.

Further, in order to evaluate the printing durability, printing with UV ink was performed under the following conditions.

(Printing conditions with UV ink) Printing machine: Hamada Star CDX-900 Printing ink: Toyo Flash Dry-OL-Red Ap (manufactured by Toyo Ink Co.) Reducer: Toyo Flash Dry Reducer op
(Toyo Ink Co., Ltd.) Plate Cleaner: Toyo Flash Dry Plate Cleaner (Toyo Ink Co., Ltd.) Paper: Fine paper Printing speed: 7,000 sheets / hour As a result, 50,000 sheets were finished, and the printed matter was good without scumming. there were.

On the other hand, when UV printing was performed using the planographic printing plate of Comparative Example 1 under the same conditions, the image on the printing plate disappeared shortly after the start of printing.

Comparative Example 2 The binder of Example 1 was changed from that of Synthesis Example 1 to that of Comparative Synthesis Example 1 (p-hydroxymethacrylanilide).
(HyPMA) unit was changed to 2-hydroxyethylmethacrylate) and the other components had the same composition as in Example 1 to obtain a photosensitive lithographic printing plate. Exposure and development were carried out in the same manner as in Example 1, but development was not possible. This shows that the phenolic hydroxyl group is essential.

Comparative Example 3 A photosensitive lithographic printing plate having the same composition was obtained except that the photosensitive member of Example 1 was changed from that of Synthesis Example 1 to that of Comparative Synthesis Example 1.

In order to evaluate the developability of this printing plate, it was subjected to forced deterioration (40 ° C., 80%, 7 days) before exposure, exposed in the same manner as in Example 1, and exposed to 4 m ² / SDP-1 fatigue developer (7 It was developed with double dilution) and developed ink (SPO-1) was applied. As a result, dirt was recognized.

Examples 4, 5 and 6 An aluminum plate having a thickness of 0.3 mm was degreased in a 5% aqueous solution of sodium hydroxide and then in a 0.5 molar aqueous solution of hydrochloric acid at a temperature of 25 ° C. and a current density of 60 A / dm ^2. The electrolytic etching treatment was carried out under the treatment time of 30 seconds. Then, after performing desmutting treatment with a 5% aqueous sodium hydroxide solution, anodizing treatment was performed in a sulfuric acid solution. The amount of the anodized film was measured by the above-mentioned method and found to be 27 mg / dm ² . Then, it was immersed in a hot aqueous solution at 90 ° C. to perform a sealing treatment. Subsequently, the obtained aluminum support was coated with a photosensitive coating solution having the following composition using a spin coater at 100 ° C.
And dried for 4 minutes to obtain a photosensitive lithographic printing plate having a film thickness of 24 mg / dm ² .

Photosensitive Solution 3,4,5 5 Photosensitive Member of Synthesis Example 2 30 parts Binder of Synthesis Examples 1,3,4 70 parts 2-Trichloromethyl-5- [β- (2′-benzofuryl) vinyl] -1,3,4 -Oxadiazole 0.6 part Victoria Blue BOH 1 part Novolac resin synthesized from p-tert-octylphenol and formaldehyde Esterification product of naphthoquinone- (1,2) -diazide-5-sulfonic acid chloride (the novolak Resin M _w = 1300, condensation rate 50 mol%) 1 part Methyl Cellosolve 700 parts Exposure and development were carried out in the same manner as in Example 1 to obtain a lithographic printing plate. Using the developed printing plate, printing with UV ink was performed under the following printing conditions.

(Printing conditions with UV ink) Printing machine: Hamada Star CDX-900 Printing ink: New Dicure Z Process Beni (Dainippon Ink and Chemicals) Reducer: Dicure AK Reducer (Dainippon Ink and Chemicals) Plate Cleaner : DIC plate cleaner (manufactured by Dainippon Ink and Chemicals, Inc.) Paper: Fine paper Printing speed: 7,000 sheets / hour All 30,000 sheets were printed, and it was found that the UV ink was suitable.

〔The invention's effect〕

As described in detail above, the positive-working photosensitive lithographic printing plate of the present invention has remarkably improved chemical resistance, can be UV ink printed without burning, has a good development latitude, and causes scumming. It has an excellent effect of not performing.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobumasa, No. 1 Sakuramachi, Hino City, Tokyo Photo 6 Konishi Roku Kogyo Kogyo Co., Ltd. (72) Inventor, Takeshi Yamamoto, No. 1 Sakura Town, Hino City, Tokyo Roku Konishi Photo Co., Ltd. In the company

Claims (4)

[Claims] 1. An (A) o-naphthoquinonediazide sulfonic acid ester of a polycondensation resin of a polyhydric phenol and an aldehyde or a ketone, and (B) a polymer compound having a structural unit represented by the following general formula [I], (In the formula, R ₁ and R ₂ are a hydrogen atom, a halogen atom, an alkyl group, an aryl group or a carboxylic acid group, R ₃ is a hydrogen atom, a halogen atom, an alkyl group or an aryl group, and R ₄ is a hydrogen atom. , An alkyl group, an aryl group or an aralkyl group, Y is an aromatic group which may have a substituent, and X is a divalent organic group connecting a nitrogen atom and a carbon atom of the aromatic group. And n is an integer of 0 to 5.) on the support, a positive photosensitive lithographic printing plate. 2. The positive-type photosensitive lithographic printing plate as claimed in claim 1, wherein Y in the general formula [I] has a phenylene group which may have a substituent or a substituent. A positive-working photosensitive lithographic printing plate characterized by containing a naphthylene group. 3. The positive-working photosensitive lithographic printing plate as claimed in claim 1, wherein the o-naphthoquinonediazide sulfonate is 5 to 40 parts of the photosensitive layer.
A positive-working photosensitive lithographic printing plate characterized by being in a weight percentage. 4. The positive photosensitive lithographic printing plate as claimed in any one of claims 1 to 3, wherein the support is an anodized aluminum substrate. -Type photosensitive lithographic printing plate.