JPS5937539A - Photosensitive lithographic plate - Google Patents

Abstract

PURPOSE:To obtain the titled lithographic plate having superior chemical resistance and superior printing resistance and developable in a weak alkaline water, by forming on a support a photosensitive layer composed of a specified compsn. of photocross-linkable polyester, an ethylenically unsatd. compd., a photopolymn. initiator, and an aliphatic carboxylic acid. CONSTITUTION:The photocross-linkable polyester is prepared having (A) aromatic dicarboxylic acid units each having formula I [(m), (n) are each 0 or 1], (B) dicarboxylic acid units each having sulfonate salt, and (C) diol units having formula II (formula III is a hydrogenated benzene ring; R<1>, R<2> are each 2-4C alkylene; R<3>, R<4> are each 1-6C alkyl; (r), (s) are each 0-3; and (t) is 0 or 1). The intended photosensitive lithographic plate is obtained by forming on a support a photosensitive layer consisting of said photocross-linkable polyester, an ethylenically unsatd. compd. having plural additionally polymeriable terminal unsatd. double bonds, a photopolymn. initiator, and aliphatic carboxylic acid or acid anhydride contg. plural carboxylic acids.

Description

[Detailed description of the invention] It is related to

In the field of photosensitive lithographic printing plates, it is well known that photocrosslinkable substances such as diazo compounds and cinnamic acid, and photopolymerizable compounds are used as photosensitive substances.

The diazo compound may be used as a diazo resin alone or in combination with a suitable organic polymer carrier.

However, in both cases, suitable supports such as aluminum,
When applied to copper, zinc, etc., the diazo compound causes harmful interaction with the surface of the support, resulting in problems such as poor developability. Therefore, before coating, the support must be subjected to a suitable surface treatment,
For example, treatment with sodium silicate has been carried out, but the stability over time has not been satisfactory under severe conditions.

On the other hand, it is well known that unsaturated polyester resins with a cinnamic acid skeleton introduced into the side chain or main chain of the polymer have good stability over time and excellent chemical resistance and printing durability. It is.

However, conventional unsaturated polyesters containing a cinnamic acid skeleton are only soluble in organic solvents;
A solution mainly containing an organic solvent had to be used as a developer to dissolve and remove the non-exposed areas. Having to use organic solvents is economically disadvantageous, and at the same time, there are problems with work safety and health, disposal of the developer, etc., and it is possible to develop with water or a weak alkaline water bath. A photosensitive lithographic printing plate was desired.

Taking these points into consideration, the present inventors developed a photosensitive material that can be developed with water or a weak alkaline aqueous solution without sacrificing the advantages of unsaturated polyester, namely, stability over time, chemical resistance, and printing durability. As a result of examining the lithographic printing plates, a patent application was filed in 1973.
iiza3II! .

Special request 1984! As shown in R67 Za3, a lithographic printing plate having a photosensitive layer consisting of a photosensitive polyester and an ethylenically unsaturated compound containing a dicarboxylic acid unit having a sulfonate salt group as an essential component was proposed.

A lithographic printing plate having such a photosensitive layer can be developed with water or a weak alkaline aqueous solution and has good chemical resistance, printing durability, and ink receptivity. In the case of oxidized aluminum plates, etc., the allowable range of developability is narrow, perhaps because the adhesiveness is too strong, and under harsh conditions such as using a tired developer or diluted 1 developer, unexposed areas may become smeared. occurs.

An object of the present invention is to provide a lithographic printing plate that does not cause stains in unexposed areas even under such severe conditions.

As a result of intensive studies, the present inventors have found that by incorporating at least an aliphatic carboxylic acid containing λ carboxyl groups into the photosensitive ITV, other performances such as chemical resistance and printing durability can be improved. A photosensitive lithographic printing plate with a wide developability range that does not cause staining in unexposed areas even under harsh conditions without damaging the light has been obtained, and the present invention has been completed.

That is, the gist of the present invention is to provide on a support at least (A) (a) with the general formula (1) (where m and n represent the number of θ or /, and at least / is Vil); an aromatic dicarboxylic acid unit represented by (b) a dicarboxylic acid unit having a sulfonate salt group, and (
0) General formula (I) (in the formula, ■ represents a hydrogenated benzene ring; R' and H*Fip represent an alkylene group of prime number - ~; Hm and R4 are hydrogen atoms or carbon numbers/~
6 alkyl group, r and eFi. ˜3, and t indicates 0 or the number of Fil. ), (B) an ethylenically unsaturated compound having at least two addition-polymerizable terminal unsaturated double bonds, (01 photoinitiator, and (DJ at least The present invention relates to a photosensitive lithographic printing plate characterized by having a photosensitive layer made of an aliphatic carboxylic acid or anhydride thereof containing at least 1 carboxyl groups.

The present invention will be explained in detail below.

(A) Photocrosslinkable polyester of the present invention comprises (a) an aromatic dicarboxylic acid unit represented by the general formula (1), (b)
) A dicarboxylic acid unit having a sulfonate salt group, preferably an aromatic dicarboxylic acid unit having a sulfonate salt group, and (0) a diol unit represented by the above general formula (II) as essential components.

The aromatic dicarboxylic acid unit represented by the general formula (1) is, for example, p-phenylene diacrylic acid, m-phenylene diacrylic acid, p-carboxycinnamic acid, m-carboxycinnamic acid, or alkyl esters thereof. derived from derivatives such as Particularly when sensitivity is taken into consideration, those represented by m:n:/ in the general formula (1) are preferable.

Such aromatic dicarboxylic acid units in the photocrosslinkable polyester usually have a molar ratio of 5-4t, especially /! A range of -410 molar is preferred.

(b) The dicarboxylic acid unit having a sulfonate salt group is, for example, ! -S) IJumsulaoisophthalic acid, j-potassium sulfoin heptathalic acid, derivatives thereof such as alkyl esters and hydroxyalkyl esters, 3-sodium sulfophthalic acid, 3-potassium sulfophthalic acid acids, l-sodium sulfophthalic acid, goopotassium sulfophthalic acid, or derivatives thereof such as alkyl esters and hydroxyalkyl esters, -monosodium sulfophthalic acid, -monopotassium sulfoterephthalic acid, or their derivatives Derivatives of alkyl esters, hydroxyalkyl esters, etc.
α-Sodium sulfosuccinic acid, β-sodium sulfoadipic acid, 2,5-disodium sulfoadipic acid or their alkyl esters or hydroxyalkyl esters%, preferably, sodium sulfoisophthalate Dimethyl acid, corn sodium sulfate 7
Derived from diptyl oterephthalate, etc.

It is sufficient that the dicarboxylic acid unit having such a sulfonate salt group is contained in the photocrosslinkable polyester in an amount of at least 1 mol or more. However, as the content increases, the adhesion to the support and the ink receptivity of highly lipophilic inks for lithographic printing tend to decrease. It is preferable to use it in

(a) The aromatic dicarboxylic acid unit and (1) the dicarboxylic acid unit having a sulfonate salt group constitute the dicarboxylic acid component of the photocrosslinkable polyester of the present invention, but sensitivity and developability are taken into consideration. Then, these (a)
The ratio of units and (b) units is l20,7~/θ (molar ratio)
It is particularly preferred that the molar ratio is 0.2 to 3 (molar ratio).

In addition, the diol unit ij represented by the general formula +1)
Examples include /, q-bis(β-hydroxyethoxy)cyclohexane, /lI-bis(-monohydroxypropoxy)cyclohexane, cyclohexanediol and their derivatives, hydrogenated bisphenol F, hydrogenated bisphenol. It is derived from A or derivatives obtained by adding ethylene oxide, propylene oxide, etc. to the hydroxyl group thereof. In consideration of the chemical resistance and printing durability of the resulting polymer, 0 in the general formula (Tl) is preferably one with a high degree of hydrogenation, and particularly preferably a cyclohexane ring. Furthermore, in consideration of the ink receptivity of the resulting polymer, it is preferable that R1 and R2 necessarily have either a linear or branched alkylene group.

In the present invention, it is preferable that the diol unit further contains (1)) an aliphatic diol unit. Such aliphatic diol units include, for example, ethylene glycol, propylene glycol, diethylene glycol, cyclopylene glycol, triethylene glycol, tetraethylene glycol, neopentyl glycol, 2,2-diethyltrimethylene glycol, co,2-di Propyl trimethylene glycol, Coether-coprobil trimethylene glycol, /, 3-propanediol, /,
It is derived from linear or branched aliphatic diols such as terbutanediol, S-bentanediol and the like.

In particular, in consideration of water solubility, chemical resistance, etc. of the resulting photocrosslinkable polyester, aliphatic diols having an ether bond such as diethylene glycol, triethylene glycol, and tetraethylene glycol are preferred.

The usage ratio of (C) the hydrogenated benzene ring-containing diol unit represented by the general formula (11) and (d) the aliphatic diol unit is determined based on the balance between ink receptivity and developability. (C) Unit and (d)
It is preferable that the ratio of units is /:θ, 2 to 3 (molar ratio).

The photocrosslinkable polyester of the present invention can be produced by a well-known method using each component providing the units (a) to (0) or (a) to (d), such as the method described in U.S. Pat. No. 36/320. It can be easily manufactured according to the following.

That is, an ester derivative of an aromatic dicarboxylic acid represented by the general formula (1), an ester derivative of a dicarboxylic acid having a sulfonate salt group, and, if necessary, an ester derivative of other well-known dicarboxylic acids, are combined into a dicarboxylic acid. As a component of the unit, the previous ii'! After mixing at least one diol component among the hydrogenated benzene ring-containing diols represented by the general formula (If) and, if necessary, an aliphatic diol as constituent components of a diol unit and heating and dissolving the mixture. After adding a titanium-based catalyst to perform the transesterification reaction, the excess diol component and the diol component generated as the polycondensation reaction progresses are distilled out of the reaction system by gradually reducing the pressure and increasing the temperature. It can be easily manufactured by

In the present invention, reduced viscosity (θ, cosr/dtN, N
-dimethylformamide solution, 30 (::) is 0. /
A photocrosslinkable polyester having a molecular weight of 0.2 to 5, particularly 0.2 to 0, tr is preferable from the viewpoint of improving sensitivity without reducing developability.

(B) of the present invention is an ethylenically unsaturated compound having at least two addition-polymerizable terminal unsaturated double bonds, which undergoes addition polymerization when irradiated with actinic rays in the presence of a photopolymerization initiator described below. It means a monomer or polymer that undergoes a reaction to harden and become substantially insolubilized. Monomer here includes dimers, dimers, and polymers other than monomers in the narrow sense. 17 sesame is also included.

Examples of ethylenically unsaturated monomers having an addition-polymerizable terminal unsaturated double bond include esters of unsaturated carboxylic acids and aliphatic polyhydroxy compounds, and esters of unsaturated carboxylic acids and aromatic polyhydroxy compounds. esters obtained by transesterification of unsaturated carboxylic acids with polyhydric carboxylic acids and polyhydric hydroxy compounds such as the aforementioned aliphatic polyhydroxy compounds and aromatic polyhydroxy compounds, or esters thereof. Further examples include those that have been modified.

Specific examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, and itaconic acid.

Examples of aliphatic polyhydroxy compounds include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, neopentyl glycol, propylene glycol, dipropylene glycol, /, 4'-buta/diol, 1. Dihydric alcohols such as coptanediol, trihydric alcohols such as trimethylol ethane, trimethylolpropane, and glycerol; tetrahydric or higher alcohols such as pentaerythritol and tripentaerythritol; polyhydric hydroxycarboxylic acids such as dihydroxymaleic acid, etc. is praised.

Examples of the aromatic polyhydroxy compound include hydroquinone, resorcinol, catechol, pyrogallol, and the like.

Examples of polyhydric carboxylic acids include phthalic acid, isophthalic acid, terephthalic acid, tetrachlorophthalic acid, trimellitic acid,
Examples include pyromellitic acid, benzophenone dicarboxylic acid, maleic acid, fumaric acid, malonic acid, geltaric acid, adipic acid, heptanoccic acid, and tetrahydrophthalic acid.

Specific examples of aliphatic polyhydroxy compounds and unsaturated carboxylic acid tonoesters include ethylene glycol diacrylate, triethylene glycol diacrylate, tetramethylene glycol diacrylate, trimethylolpropane triacrylate, trimethylolethane triacrylate, and pentaerythritol diacrylate. ,
Acrylic acid esters such as pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, tripentaerythritol octaacrylate, glycerol diacrylate, triethylene glycol dimethacrylate, Tetramethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, pentaerythritol dimethacrylate,
Methacrylic acid esters such as ethylene glycol diacrylate, butanediol dimethacrylate, sorbitol tetramethacrylate, ethylene glycol diacrylate, butanediol dimethacrylate, sorbitol tetramethacrylate, ethylene Itaconic acid esters such as glycol shitaconate, propylene glycol shitaconate, /1,2-butanediol shitaconate, tetramethylene glycol shitaconate, pentaerythritol triitaconate, ethylene glycol dicrotonate, jetele/glycol di Examples include crotonic acid esters such as crotonate and pentaerythritol tetracrotonate, and maleic acid esters such as ethylene glycol dimaleate, triethylene glycol dimaleate, and pentaerythritol dimaleate.

Examples of esters of aromatic polyhydroxy compounds and unsaturated carponic acids include hydroquinone diacrylate, hydroquinone dimethacrylate, resorcin diacrylate, resorcin dimethacrylate, and pyrogallol triacrylate.

The ester obtained by the esterification reaction of an unsaturated carboxylic acid with a polyvalent carboxylic acid and a polyvalent hydroxy compound is not necessarily a single product, but typical examples are shown in Table 1. 2 in the table represents an acryloyl group or a methacryloyl group.

Table 1 Z-00,H, -000-0,H, -Coo-0,H,
0-ZZ-+002)144000-fOH,-I
Coo-(-G, H, O-); ZZ-foo, H,
+5OOC! -0H-0H-(!OO+C,H,0+5
Zz-foa, H,-), ooo r::J-co
o-fa, H, o-), Zz-(oc2H,-),
000 Z-00H, 1, O, H, O, H, OH, O-Z\
1 C / \ / \Z-0 (
3H,OH,000-Cj6H,-0000H,OH,
0-ZZ-00H,\2ocH,,0H-00°-0H=OH-Co°=,O
H,0-ZH20-Z Z-QC,I(,-000-06H,-000-0,H
,-0H2-QC! H,OR14-Z Z-00H,,0-01(,000-06H,-Co°
0H2-0): 'Demand HO-OR.

Z-00H,, CH20-Z Z-00Ht, 0-OH, Ooo-0H=CH-COO
OH,-'=:':O,Z-00H2 Z-QC2H,-000-(-OH29000-(!H
.

Examples of compounds having an ethylenically unsaturated double bond used in the invention include acrylamides such as ethylenebisacrylamide and hexamethylenebisacrylamide; methacrylamides such as ethylenebismethacrylamide and hexamethylenebismethacrylamide; Examples include allyl esters such as diallyl phthalate, diallyl malonate, diallyl fumarate, and triallyl isocyanurate, and vinyl-containing compounds such as divinyl adipate, divinyl phthalate, and ethylene glycol divinyl ether.

Examples of modified ethylenically unsaturated monomers having addition-polymerizable terminal unsaturated double bonds include, for example, Japanese Patent Application No. 1986-1/1999.
Examples include monomers having a free carboxyl group as described in θ9. It contains hydroxyalkyl groups (
They can be prepared by the reaction of meth)acrylates with acid anhydrides of dibasic carboxylic acids.

Examples of (meth)acrylates containing a hydroxyalkyl group include trimethylolethane diacrylate, trimethylolpropane diacrylate, trimethylolpropane dimethacrylate, crystall diacrylate, glycerol dimethacrylate, hentaerythritol diacrylate, and pentaerythritol dimethacrylate. , pentaerythritol triacrylate, pentaerythritol trimethacrylate, dipentaerythritol tetraacrylate, and other polyvalent esters.

Examples of the acid anhydride for reacting with these (meth)acrylates having a hydroxyalkyl group include succinic anhydride and maleic anhydride.

Examples include itaconic anhydride, phthalic anhydride, hexahydrophthalic anhydride, and tetrahydrophthalic anhydride.

A (meth)acrylate compound having a carboxyl group is prepared by a half-esterification reaction between the (meth)acrylate having a hydroxyalkyl group and the acid anhydride. It is preferable to heat the mixture in the presence of a so-called thermal polymerization inhibitor in the absence of a solvent or in the presence of a catalyst such as pyridine, tertiary amine, sulfuric acid, p-toluenesulfonic acid, etc., if necessary. Benzene, toluene, methyl ethyl ketone, dioxane, etc. are useful as the reaction solvent.

In these ethylenically unsaturated compounds having at least one addition-polymerizable terminal unsaturated double bond, considering the developability in a weakly alkaline aqueous solution containing no water or organic solvent, alcoholic hydroxyl groups are present in the molecule. , phenolic hydroxyl lk or those containing free carboxyl groups, such as (meth)acrylic esters such as pentaerythritol triacrylate, and succinic anhydride modified products thereof are particularly preferred.

The unsaturated compound is based on 700 parts by weight of the photocrosslinkable polyester! It is used in a range of 200 parts by weight, preferably 10 to io.

Parts by weight range.

The photopolymerization initiator (0) of the present invention generates radicals upon irradiation with actinic rays, and undergoes the addition polymerization reaction of the ethylenically unsaturated compound having at least one addition-polymerizable terminal unsaturated double bond (B). It brings about

The photopolymerization initiator that can be used in the present invention needs to be capable of efficiently expressing the photopolymerization reaction without inhibiting the photocrosslinking reaction of the photocrosslinkable polyester described above.

In addition, as a six-light lithographic printing plate, it is essential to irradiate active light to draw an image, but the light source used in this process usually emits light energy with a wavelength of 3 daOnm or more. , the photopolymerization reaction must be efficiently expressed in this wavelength range. In addition, the photocrosslinking reaction of the photocrosslinkable polyester described above occurs sufficiently in polyesters, but in order to achieve a practical sensitivity of 5, a sensitizer as described below is usually added to the photosensitive layer. It is served to This sensitizer also takes into consideration the light energy distribution of the light source used for image drawing. It is a chemically designed product that can efficiently convert that energy into photocrosslinking reactions.

As described above, the photopolymerization initiator (0) in the present invention sufficiently coexists with the light energy distribution of these light sources and the light absorption of the sensitizer added to promote the photocrosslinking reaction, and the photopolymerization initiator is In parallel with the photocrosslinking reaction of the polyester, (B) a strong photopolymerization reaction of the ethylenically unsaturated compound having at least 0 addition-polymerizable terminal unsaturated double bonds. Must be an initiator.

In view of this, the present inventors have investigated and found that a so-called composite initiator such as a combination of benzyl-z, +,'-bis(dimethylaq))benzophenone is particularly effective as a photopolymerization initiator in the present invention. I discovered that. The composite initiator referred to here refers to the fact that by using a mixture of specific compounds, a mutual activation effect appears as a photopolymerization initiator in a photopolymerization reaction, which cannot even be predicted when each is used alone. It refers to a unique mixture that exhibits such effects.

Examples of this composite initiator include compounds such as benzoin, pentuin methyl ether, benzyl, and fluorenone disclosed in Tokko Shotei Dar OθA Kuni, and p, 4z'-
All synthesis of bis(dialkylamino)benzophenone, benzyl and fluorenone, or JP-A-37-
1040! benzyls having substituents disclosed in 2003 and the general formula (in the formula, R1, R6, R and R8 represent an alkyl group, and U and v (dθ, /, and &″: J, −). A combination of p-dialkylami/phenylketone represented by the general formula disclosed in Japanese Patent Application Shosa J-93 Za 6s (wherein R@ represents an alkyl group, and Y represents 10-1-8 −
1-8e-1-0H is a covalent atom or atomic group selected from OH- and -NRlo-, which forms a heteroaromatic ring B together with a trivalent nitrogen atom, and RI01d represents a hydrogen atom or an alkyl group. , Ring A is a benzene ring or naphthalene ring which may have a # radical and is fused with Ring B. ) A combination of p-dialkylaminostilbene derivative and hexaarylbiimidazole,
Special request! rA-//13Jde (wherein Rlm represents an alkyl group, Rlm represents a hydrogen atom or an alkyl group, ring Ai; benzene which may have an i substituent) p- ring or naphthalene ring fused with a thiazole ring.
Combination of dialkylaminocinnamylidene derivative and hexaarylbiimidazole, Patent Application 1973-1 Koza 1I
ob and patent application ShojA-/? ? 1IfflI, where RIM and R" ij represent an alkyl group, ring A and ring B represent a benzene ring or naphthalene ring which may have a substituent, and xe represents an anion. (wherein, Ras, R1l+ and RI7 are optionally substituted alkyl groups) and a cyanine dye or thiapyrylium salt represented by the formula or an aryl group, an alkenyl group, a piperidino group, -NR,, -OR.

-S (here, Rd represents a hydrogen atom or an alkyl group), and at least one of them represents a mono- or di-split trihalogen-substituted methyl group. 8-) IJ azine derivatives represented by ), etc. can be mentioned, and any of them can be suitably used. In particular, a combination of compounds such as benzoin, benzoin methyl ether, benzyl, fluorenone, and y'-bis(dialkylamino)benzophenone is preferred.

Addition of each specific compound constituting this composite initiator i
It is advantageous to use o, i in the photosensitive layer in a range of weight percent to 20 weight percent, preferably lj: / weight percent to /θ weight percent.

(A) photocrosslinkable polynisdel, (B) ethylenically unsaturated compound, (C) a photosensitive layer that essentially contains a photopolymerization initiator, and (D) an aliphatic group containing at least 0 carboxyl groups of the present invention. The developability is further improved by containing carboxylic acid or its anhydride in the photosensitive layer, usually 0.0 to 1% by weight, more preferably 0.5 to 10% by weight.

Examples of aliphatic carboxylic acids containing at least two or more galboxyl groups include saturated aliphatic carboxylic acids,
Examples include unsaturated fatty acids, aliphatic dicarboxylic acid anhydrides, hydroxy acids, and amino acids.

Specific examples of saturated aliphatic carboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, speric acid, azelaic acid, and sebacic acid.

Specific examples of unsaturated fatty acids include fumaric acid and maleic acid, and examples of aliphatic dicarboxylic acid anhydrides include succinic anhydride and glutaric anhydride.

Specific examples of hydroxy acids include tartaric acid, malic acid, citric acid, etc., and specific examples of amino acids include glutamic acid, aspartic acid, etc.

Preferably, saturated aliphatic carboxylic acids and hydroxy acids are used, particularly preferably oxalic acid, tartaric acid, malic acid and the like.

In addition to these essential components, it is also a very useful means to add (E) a resin containing a phenolic hydroxyl group. Addition of this resin containing a phenolic hydroxyl group significantly improves the water resistance of the lithographic printing plate when exposed to light.

Such resins include so-called phenol resins synthesized by addition condensation reaction of phenols and aldehydes or IT-taketones, poly-hydroxyphenyl resins such as poly-p-hydroxystyrene, or other substituents. Examples include poly-hydroxyphenyl resin containing. In addition, the 7-enolic hydroxyl group in these resins may be partially converted into an ester by reacting with an acid chloride such as cinnamic acid chloride or (meth)acrylic acid chloride, or with an acid such as succinic anhydride or phthalic anhydride. Resins partially modified to contain free carboxylic acid residues by reaction with anhydrides are also useful.

The resin containing a phenolic hydroxyl group is used in an amount of 1 to 200 parts by weight based on the photocrosslinked tt polyester lθθ, preferably in a range of Fir to 750 parts by weight.

The photosensitive lithographic printing plate of the present invention comprises (A) a photocrosslinkable polyester as described above on a support, (B) an ethylenically unsaturated compound having at least two addition-polymerizable terminal unsaturated double bonds, It is obtained by applying a photosensitive composition containing (0) a photopolymerization initiator and (D) an aliphatic carboxylic acid.

This photosensitive composition is prepared by dissolving the photocrosslinkable polyester in a solvent, and then adding an ethylenically unsaturated compound having at least 0 addition polymerizable terminal unsaturated double bonds, a photopolymerization initiator, and an aliphatic carboxylic acid. is easily produced by dissolving it in this solution.

Suitable solvents vary depending on the composition and molecular weight of the photocrosslinkable polyester, but when the content of dicarboxylic acid units having sulfonate salt groups is low, methylene chloride,
Chlorinated solvents such as chloroform, trichloroethane, chlorobenzene, and dichlorobenzene, alcoholic solvents such as furfuryl alcohol, tetrahydrofurfuryl alcohol, and benzyl alcohol8. Ether derivatives of ethylene glycol and diethylene glycol such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monophenyl ether, diethylene glycol monopropyl ether, diethylene glycol monoether ether, diethylene glycol monopropyl ether, Ester solvents such as ethylene glycol ether ether acetate, diethylene glycol ethyl ether acetate, ethyl acetate, nitrogen-containing solvents such as dimethylformamide, N-methylpyrrolidone, nitroethane, nitrobenzene, methyl ethyl ketone,
Examples include ketone solvents such as methyl isobutyl ketone, cyclohexanone, methyl cyclohexanone, and goometeludermethoxycopentanone, and solvents such as dimethyl sulfoxide.

On the other hand, when the content of dicarboxylic acid units having sulfonate salt groups is high, water, diacetone alcohol,
Methyl lactate, ethyl lactate, n-butyl lactate, lactic acid-1
Keto alcohols such as -butyl and hydroxy group-containing fatty acid esters are also effective.

The photosensitive layer of the present invention may contain various known additives in addition to the above-mentioned components, if necessary.

For example, it may contain additives such as other resins, colorants, plasticizers, stabilizers, sensitizers, etc. within a range that does not inhibit the developability in a weakly alkaline aqueous solution. These additives may be added when preparing the photosensitive composition. Here, the sensitizer is a substance that promotes the photocrosslinking reaction of the photocrosslinkable polyester itself, and is a conventionally known agent, such as Penn's Anthroy,
A, nopenzanthrone derivatives such as / /-dichlorobenzanthrone, //-chloro-6-hydroxypenzanthrone, /-carboethoxy-two-keto-3-methyl-37"j'-/, 9-benzanthrone, 79 g - Quinones such as dichloroanthraquinone, /, g-dimethoxyanthraquinone, /, Coppen's anthraquinone,!
- ditroacenaphthene, - ditrofluorenone, 2,
t-dinitrofluorenone, l-nitronaphthalene, l
, 7- or polynitro compounds such as j-dinitronaphthalene, -1-dibenzoylmethylene-3-methyl-β
- Naphthothiazoline, cobenzoylmetherene - 3-methyl-β-naphthothiazoline, Coates (coufroyl)
Naphthothiazoline derivatives such as methylene-3-methyl-β-naphthothiazoline are preferred.

Examples of the stabilizer include known thermal polymerization inhibitors, such as hydroquinone, methylhydroquinone, p-methoxyphenol, pyrogallol, catechol, 2.6-
Di-t-butyl-p-cresol, β-naphthol, etc. can be preferably used.

The photosensitive composition of the present invention can be applied by dipping onto a support such as a polymer film or a metal plate such as a polyethylene terephthalate film, a zinc plate for printing, an aluminum plate for printing, a silicon wafer, a chromium-deposited glass plate, etc. in accordance with a conventional method.・Coat, coating rod, spinner coat,
It is possible to apply by a well-known coating method such as spray coating.

As a photosensitive lithographic printing plate, one coated on a printing aluminum plate whose surface has been anodized is suitable. In particular, an aluminum plate which has been anodized in a bath of phosphoric acid or a mixed acid bath of phosphoric acid and sulfuric acid is suitable for printing. It is particularly preferred since it has good adhesion with the photocrosslinkable polyester of the invention.

On the photosensitive lithographic printing plate produced in this way, an image is drawn by overlaying the object in a conventional manner or by irradiating it with an electron beam, etc., and then it is developed using a weakly alkaline aqueous solution. A corresponding image can be formed on the support. In particular, the present invention is extremely useful compared to conventional systems because it allows good development without the need for particularly containing an organic solvent in the developer. Of course, even an alkaline aqueous solution containing a small amount of organic solubles having an affinity for water shows extremely excellent developability.

The present invention has been explained in detail above.
The fl lithographic printing plate can be developed with a weakly alkaline aqueous solution, and the resulting printing plate has excellent abrasion resistance, chemical resistance, and printing durability, and is also highly lipophilic for lithographic printing. It has the excellent feature of ameliorating printing ink and receiving it well.

Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

Production example/diethyl p-phenylene diacrylate 3g, 6t (/
II Ommoj), S-sodium sul 7-oisophthalate dimethyl/7. t&f(Aθmmot), /,
lI-His(2-hydroxyethoxy)-cyclohexane/6.32? (p, Ommol) and triethylene glycol λ80f (/4!Ommol), 2
00 ml was placed in a three-necked flask, and a &% ethanol solution of n-butyl orthotitanate/θd was added as a catalyst, while supplying 9 gases.

? The temperature was gradually raised while stirring at rotational speeds of Or, p, m, and transesterification was carried out at 20C for about 30 minutes.

Then, the pressure was reduced to 54 pHy at 1.2 JθC.

The temperature was quickly raised to AOc, and the reaction was continued for about 2θ minutes.

Next, reduce the pressure to 1 Hy with roller θC.

The mixture was reacted for a minute, and excess diol and by-product diol were distilled off to obtain a photocrosslinkable polymer.

Production example Co-diethyl p-phenylene diacrylate 32. zagf (
/2ommot), 23.6g of dimethyl j-sodium 7-oisophthalate? (za. mmoz), /, lI-
His(2-hydroxyethoxy)-cyclohexane/2
．． ．． 211t(Aθmmoj) and triethylene glycol 27. Of(/θmmot) was placed in a 20θ three-hole flask, 1θml of a 5% ethanol solution of n-butyl orthotitanate was added as a catalyst, and while blowing nitrogen gas, AOr, p, m, The temperature was gradually raised while stirring at a rotational speed, and the transesterification reaction was carried out at 2.20C for about an hour.

μ Next, the pressure was reduced to k (RfHy) at 22θC, and then the temperature was immediately raised to 243'C''J, and the reaction was carried out for IO minutes.

tL Kawa furthermore, KotsC/'fH? The reaction mixture was allowed to react for 5 minutes under reduced pressure, and excess diol and by-product diol were distilled off to obtain a photocrosslinkable polymer.

Comparative Example A photosensitive solution having the composition shown in Table/ was coated on an aluminum plate which had been subjected to anodization treatment in a phosphoric acid bath after graining. After cooling, the plate was dried at TOC for 7 hours to obtain a photosensitive lithographic printing plate.

The coating amount after drying was /31n9/dm2.

This photosensitive lithographic printing plate was exposed to light for so seconds using a high-pressure mercury lamp for 3 days through a step wedge with an optical density difference θ, /j.

Next, it was immersed in a developer having the composition shown in Table 2 at room temperature for 7 minutes, and the unexposed areas were removed by rubbing lightly with a soft cloth.

The ink receptivity and chemical resistance to various solvents of the obtained image area were 1. It was good.

The developability was good under standard conditions, but staining occurred in non-image areas when a diluted developer or a fatigued developer was used during short-time development or at a warm temperature.

Table 1 Table 1 Examples 7 to 6 and Comparative Examples--! In Comparative Example/, a photosensitive lithographic printing plate was produced in the same manner except that the carboxyl group-containing compound shown in Table 3 was further added to the photosensitive solution having the composition shown in Table/, and the plate was prepared under a-fold dilution conditions. The developability of the film was investigated. The results are shown in Table 3.

Clothing 3 The developability is as below! Indicated by graded evaluation.

S: Very good bow Good 3: Staining occurred in some areas 22 Staining occurred in some areas/: Staining occurred From the above results, when the carboxyl group-containing compounds shown in Examples/- Example 7 were added, the developing solution It was found that the permissible range was wide and good developability was exhibited even after repeated development.

Example? In Comparative Example/, a photosensitive lithographic printing plate was produced in the same manner except that a photosensitive liquid having the composition shown below was used.

This photosensitive planographic printing plate has an optical density difference of 0. /! 1. Through the step wedge. ? Exposure was performed for 70 seconds using a KW high pressure mercury lamp.

Next, sodium silicate! When the film was developed with an alkaline aqueous solution containing sodium hydroxide and sodium hydroxide and a 1:1 diluted solution, no staining occurred in either case.
A film that developed well was obtained.

Furthermore, the ink receptivity and chemical resistance of the obtained image area were also good.

Comparative Example 6 In Example 7, a photosensitive lithographic printing plate was manufactured using a photosensitive solution having the same composition except that tartaric acid was not added, and the developability was examined. Occurred.

Photosensitive lithographic printing plates were produced in the same manner as in Examples j~// and Comparative Example//, except that the photosensitive liquid having the composition shown in Table 3 was used.

This photosensitive planographic printing plate has an optical density difference of 0. /k for 10 seconds with a KW high-pressure mercury lamp through a step wedge.
[)Th, then 30 parts by weight of benzyl alcohol,
Aqueous solution of sodium silicate/S, 70 parts by weight of sodium isopropylnaphthalene sulfonate, and 9'l of water!
Development was carried out under conditions of -fold dilution using a developer consisting of parts by weight.

The results are shown in Table 3.

Further, in all cases of Example ff-/i, the sensitivity, ink receptivity and chemical resistance were good.

Table 5

Claims (2)

[Claims] (1) On a support, at least (A) (-1 represented by the general formula (I) (wherein m and n are the number of Ol or L, and at least one digit/) is disposed on the support. ('b) a dicarboxylic acid unit having a sulfonate group, and (C) the general formula (I) (wherein 0 represents a hydrogenated benzene ring, R1 and R2 represent a carbon R3 and R4 represent a hydrogen atom or an alkyl group having 7 to 3 carbon atoms, r and B represent a number of θ to 3, and t represents θ or l.
Indicates the number of ) a photocrosslinkable polyester containing a diol unit represented by (B) an ethylenically unsaturated compound having at least one addition polymerizable terminal unsaturated double bond, (01 photopolymerization initiator, and ( D) A photosensitive lithographic printing plate characterized by having a photosensitive layer comprising an aliphatic carboxylic acid containing at least one carboxyl group or an anhydride thereof. (2) (DJ) An aliphatic carboxylic acid containing at least one carboxyl group is added in the photosensitive layer from 0.01 to
The photosensitive lithographic printing plate according to claim 1, containing 15% by weight.