JPH06105350B2 - Photosensitive composition for lithographic printing plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a photosensitive composition, and particularly to a photosensitive composition which is preferably used for a photosensitive lithographic printing plate. More specifically, it relates to a photosensitive composition which is preferably used for producing a photosensitive lithographic printing plate having excellent ink receptivity.

[Conventional technology]

The majority of those used as photosensitive substances in printing materials which have been presensitized are diazonium compounds, and among them, the most commonly used ones are diazo compounds represented by formaldehyde condensation products of p-diazodiphenylamine. There is resin.

The composition of the photosensitive layer of the photosensitive lithographic printing plate using a diazo resin, for example, as described in U.S. Pat.No. 2,714,066, the diazo resin alone, that is, without a binder, for example, As described in JP-A-50-30604, it can be classified into a mixture of a binder and a diazo resin. In particular, in recent years, many photosensitive lithographic printing plates using a diazonium compound have a photosensitive layer composed of a diazonium compound and a polymer serving as a binder in order to provide high printing durability.

Examples of such a photosensitive layer include a so-called alkali developing type in which an unexposed portion is removed (developed) by an aqueous alkaline developer and an organic solvent-based developer as described in JP-A-50-30604. A so-called solvent-developing type which is removed is known. In recent years, attention has been paid to the alkali developing type from the viewpoint of occupational safety and health, which is mainly determined by the properties of the binder. The method for imparting alkali developability to the binder is described in the above-mentioned JP-A-
A method of copolymerizing a carboxylic acid-containing monomer as described in 50-30604, a hydroxy group of polyvinyl alcohol and a cyclic group such as phthalic anhydride as described in U.S. Pat. No. 2861058. There is a method of introducing a carboxylic acid into a polymer by reacting an acid anhydride.

However, the obtained photosensitive layer was insufficient in inking property, which is an important characteristic of the lithographic printing plate.

Then, as a method of improving the inking property, a method of adding a polymer compound as described in JP-A-55-527 has been proposed, but it is still insufficient and further improvement is made. Was desired.

[Problems to be solved by the invention]

An object of the present invention is to provide a photosensitive composition suitable for producing a photosensitive lithographic printing plate which is alkali-developable and has further improved inking property.

[Means for solving problems]

The present invention provides a photosensitive composition for a lithographic printing plate containing a photosensitive diazo resin and a polymer binder, further comprising i) an alkyl group having 4 or more carbon atoms, a substituted alkyl group, an aralkyl group, a substituted aralkyl group and an aryl group. Or an acrylate or methacrylate having a substituted aryl group, ii)
An acrylate or methacrylate having 3 to 20 carbon atoms, containing 30% by weight or more of fluorine, and having a fluoroaliphatic group (Rf group) having at least three terminal carbon atoms fully fluorinated, iii) A photosensitive composition comprising a copolymer containing at least one of oxyalkylene acrylate, poly (oxyalkylene) acrylate, oxyalkylene methacrylate or poly (oxyalkylene) methacrylate as a structural unit. .

I. Structural unit i) Specific examples of the structural unit i) contained in the copolymer used in the present invention (hereinafter referred to as the copolymer of the present invention) include:
The following acrylic acid esters can be mentioned.

For example, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, pentyl acrylate, octyl acrylate, nonyl acrylate, decyl acrylate, lauryl acrylate, stearyl acrylate, behenyl acrylate, benzyl acrylate. , Methylbenzyl acrylate, dimethylbenzyl acrylate, chlorobenzyl acrylate, bromobenzyl acrylate, ethylbenzyl acrylate, n-propylbenzyl acrylate,
Iso-propylbenzyl acrylate, n-butylbenzyl acrylate, iso-butylbenzyl acrylate, tert-butylbenzyl acrylate, phenyl acrylate, naphthyl acrylate, tolyl acrylate, xylyl acrylate, chlorophenyl acrylate, acrylic acid Bromophenyl, ethylphenyl acrylate, n-propylphenyl acrylate, iso-propylphenyl acrylate,
These are n-butylphenyl acrylate, iso-butylphenyl acrylate, and tert-butylphenyl acrylate.
Preferred are lauryl acrylate, stearyl acrylate, behenyl acrylate, tert-butyl acrylate, tert-butylbenzyl acrylate, and tert-butylphenyl acrylate.

Specific examples of the structural unit contained in the copolymer of the present invention include methacrylic acid esters. For example, n-butyl methacrylate, isomethacrylate
-Butyl, tert-butyl methacrylate, pentyl methacrylate, octyl methacrylate, nonyl methacrylate,
Decyl methacrylate, lauryl methacrylate, stearyl methacrylate, behenyl methacrylate, benzyl methacrylate, methylbenzyl methacrylate, dimethylbenzyl methacrylate, chlorobenzyl methacrylate, bromobenzyl methacrylate, ethylbenzyl methacrylate, n-propyl methacrylate. Benzyl, methacrylic acid
iso-propylbenzyl, n-butylbenzyl methacrylate, iso-butylbenzyl methacrylate, tert-butylbenzyl methacrylate, phenyl methacrylate, naphthyl methacrylate, tolyl methacrylate, xylyl methacrylate, chlorophenyl methacrylate, bromophenyl methacrylate. , Ethylphenyl methacrylate, n-propylphenyl methacrylate, iso-propylphenyl methacrylate, n-butylphenyl methacrylate, iso-butylphenyl methacrylate, and tert-butylphenyl methacrylate. Preferably lauryl methacrylate, stearyl methacrylate, behenyl methacrylate,
These are tert-butyl methacrylate, tert-butylbenzyl methacrylate, and tert-butylphenyl methacrylate.

II. Structural Unit ii) The fluoroaliphatic group Rf contained in the structural unit contained in the copolymer of the present invention is a saturated and generally monovalent aliphatic group. It is straight-chain, branched and, if sufficiently large, cyclic or combinations thereof (eg alkylcycloaliphatic radicals). The fluoroaliphatic backbone can include oxygen and / or trivalent nitrogen heteroatoms in the chain attached only to carbon atoms, which heteroatoms provide a stable bond between the fluorocarbon groups and Does not interfere with inert properties. In order to exert a sufficient effect, the Rf group has 3 to 20,
It preferably has 6 to 12 carbon atoms, and has 30% by weight or more, preferably 40% by weight or more, of fluorine bonded to carbon atoms. At least three carbon atoms at the end of the Rf group are fully fluorinated. End of the Rf group is, for example, CF ₃ CF ₂ CF ₂ - a is the preferred Rf groups is a substantially fully fluorinated alkyl group as CuF _{2n + 1} (n is an integer of 3 or more) .

If the Rf group fluorine content is less than 30% by weight, the object of the present invention cannot be sufficiently achieved. It is more effective if the fluorine atom is localized at the end of the Rf group. Even if the number of carbon atoms in the Rf group is 2 or less, the fluorine content can be increased, but the total amount of fluorine atoms becomes insufficient and the effect is weak. Has 2 carbon atoms
Even if the fluorine content in the copolymer is increased by increasing the ratio of the following fully fluorinated Rf group-containing monomer to the copolymer, the fluorine atoms are not localized, No effect.

On the other hand, when the number of carbon atoms of the Rf group is 21 or more, the solubility of the obtained copolymer in a solvent becomes low when the fluorine content is high, and when the fluorine content is low, the localization of the fluorine atoms is sufficient. It is no longer possible to obtain a sufficient effect.

The above fluoroaliphatic group-containing acrylate is described in US Pat.
No. 803,615, No. 2,642,416, No. 2,826,564, No.
3,102,103, 3,282,905 and 3,304,278.

Other fluoroaliphatic group-containing terminal ethylenically unsaturated monomers suitable for producing the copolymer of the present invention, U.S. Patent Nos. 2,592,069, 2,995,542 and 3,078,245,
No. 3,081,274, No. 3,291,843 and No. 3,325,16
The ethylenically unsaturated materials described in U.S. Pat. No. 3 and suitable for making the above fluoroaliphatic group-containing terminal ethylenically unsaturated monomers are described in US Pat. No. 3,574,791.

III. Structural unit iii) Specific examples of the structural unit contained in the copolymer of the present invention include oxyalkylene acrylates such as And the like, and as the oxyalkylene methacrylate, for example, And so on.

Poly (oxyalkylene) acrylate, poly (oxyalkylene) methacrylate polyoxyalkylene groups
R in (OR) _n is an alkylene group having 2 to 4 carbon atoms,
For example, -CH ₂ CH _2- , -CH ₂ CH ₂ CH _2- , -CH (CH ₃ ) CH ₂ -or -CH (C
It is preferably H ₃ ) CH (CH ₃ )-. The oxyalkylene units in said poly (oxyalkylene) group may be the same as in poly (oxypropylene),
Alternatively, two or more oxyalkylenes different from each other may be randomly distributed, which may be a linear or branched oxypropylene and oxyethylene unit, or a linear or branched oxyalkylene unit. It may be present as a block of propylene units and a block of oxyethylene units. The poly (oxyalkylene) chain may be one or more chain bonds (eg -S-, etc.). If the linkage of the chain has a valence of 3 or more, this provides a means for obtaining the oxyalkylene units of the molecular chain. Such poly (oxyalkylene) acrylate and poly (oxyalkylene) methacrylate are commercially available hydroxy poly (oxyalkylene) materials, for example, trade name "Pluronic" [Pluronic
(Asahi Denka Kogyo Co., Ltd.)], "Adeka Polyether"
(Asahi Denka Kogyo Co., Ltd.)], "Carbowax" [Carb
owax (Glyco Products) Co.
Produced by the known method), "Triton" (made by Rohm and Hass Co.) and PEG (made by Dai-ichi Kogyo Seiyaku Co., Ltd.) by a known method. , Methacrylic acid, acrylochloride or acrylic anhydride.

IV. Copolymers of the Invention The copolymers of the invention can be prepared, for example, by free radical initiated copolymerization. The molecular weight of the copolymer is controlled by adjusting the concentration and activity of the initiator, the concentration of the monomers and the temperature of the polymerization reaction, and of chain transfer agents such as thiols such as n.
-Can be adjusted by adding octyl mercaptan.

The content of the structural unit i) in the copolymer of the present invention is 10 to
It is 80 mol%, preferably 15 to 70 mol%. If it is less than 10 mol%, the effect of improving the inking property becomes insufficient, and if it is more than 80 mol%, the developability is deteriorated. The content of structural unit ii) is 10
It is -80 mol%, preferably 10-70 mol%. If it is less than 10 mol%, the effect of improving the inking property becomes insufficient, and if it is more than 80 mol%, the solubility in the coating solvent deteriorates. The content of the structural unit iii) is 5 to 80 mol%, preferably 5 to 70
mol%. If it is less than 5 mol%, the solubility in the coating solvent and the developing solution will be insufficient, and if it is more than 80 mol%, the effect of improving the inking property will be insufficient. Further, each of these structural units may be copolymerized with two or more kinds. Further, in the copolymer of the present invention, in addition to the structural units i) to iii), a monomer copolymerizable therewith can be copolymerized to an extent not impairing the inking property, but the content thereof is 20 mol%. Should be:

The weight average molecular weight of the copolymer of the present invention is preferably 5,000.
Or more, more preferably 10,000 or more. If it is less than 5,000, the effect of improving the inking property becomes insufficient. The proportion of the copolymer of the present invention contained in the photosensitive composition is 0.01 to 10% by weight, preferably 0.05 to 8% by weight. If it is less than 0.01% by weight, the effect of improving the inking property becomes insufficient, and if it is more than 10% by weight, the developability deteriorates.

V. Photosensitive diazo resin Next, the photosensitive diazo resin used in the present invention is a diazo resin represented by a condensate of an aromatic diazonium salt and an active carbonyl group-containing compound, for example, formaldehyde. In particular, an organic solvent-soluble diazo resin is preferably used.

Examples of the diazo resin include organic solvent-soluble diazo resin inorganic salts, which are reaction products of a condensate of P-diazodiphenylamine and formaldehyde or acetaldehyde, and hexafluorophosphate or tetrafluoroborate, and JP-B-47- 1167 and the sulfonates, such as P-toluenesulfonic acid or salts thereof, propylaphthalenesulfonic acid or salts thereof, butylnaphthalenesulfonic acid or salts thereof, dodecylbenzenesulfonic acid or Examples thereof include a salt thereof, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid or a salt thereof, dioctylnaphthalenesulfonic acid or a salt thereof, or an organic solvent-soluble diazo resin organic salt which is a reaction product with a mixture thereof.

Also, as shown in JP-A-58-27141, a mesitylene sulfonate formed by condensing 3-methoxy-4-diazo-diphenylamine with 4,4'-bis-methoxy-methyl-diphenyl ether is also available. Appropriate.

VI. Polymer Binder Further, the polymer binder used in the present invention may be any polymer binder that can be dissolved or swollen in an alkaline aqueous solution developer and can be photocured by the above-mentioned photosensitive diazo resin.

Acrylic acid as a particularly suitable organic polymer binder,
Copolymers containing methacrylic acid, crotonic acid or maleic acid as an essential component, such as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, acrylonitrile or methacryloyl as described in JP-A-50-118802. Multi-component copolymers with nitrile, acrylic acid or methacrylic acid and optionally other copolymerizable monomers, the terminal of which is a hydroxy group as described in JP-A-53-120903, and dicarboxylic acid Multi-component copolymers of acrylic acid or methacrylic acid, acrylic acid, or methacrylic acid esterified with a group containing an acid ester residue and optionally other copolymerizable monomer, JP-A-54-98614 A monomer having an aromatic hydroxyl group at the terminal as described in the publication (for example, N
-(4-hydroxyphenyl) methacrylamide, etc.), acrylic acid or methacrylic acid and optionally a multi-component copolymer with other copolymerizable monomers,
Japanese Patent Application No. 60-109, which is a multi-component copolymer composed of an alkyl acrylate, acrylonitrile or methacrylonitrile, and an unsaturated carboxylic acid as described in JP-A-56-4144.
122, 60-123863, 60-198742, modified polyvinyl acetal resin, Japanese Patent Application No. 60-263232,
Examples thereof include polyurethane resins as described in 60-263233.

In addition to these, acidic polyvinyl alcohol derivatives and acidic cellulose derivatives are also useful. Further, a polymer compound described in British Patent No. 1370316 in which polyvinyl acetal is solubilized with an alkali is also useful.

The content of the photosensitive diazo resin and the polymeric binder in the photosensitive composition is 3 to 40% by weight of the diazo resin based on the total amount of the both, and the polymeric binder is 97 to 60%.
Suitably it is in weight percent. The smaller the content of the diazo resin is, the higher the sensitivity is. However, when the content is less than 3% by weight, it is insufficient for photocuring the binder, and the photocured film tends to be swollen by the developing solution during development and the film becomes weak. is there.
On the other hand, if the content of the diazo resin is more than 40% by weight, the sensitivity becomes low and practically difficult. Therefore, the more preferable range is 5 to 30% by weight of the photosensitive diazo resin and 95 to 70% by weight of the polymer binder.

VII. Other Additives Various additives can be further added to the photosensitive composition used in the present invention.

For example, alkyl ethers (such as ethyl cellulose and methyl cellulose) for improving coating properties, surfactants (such as fluorochemical surfactants), film flexibility,
Plasticizer for imparting abrasion resistance (eg tricresidyl phosphate, dimethyl phthalate, dibutyl phthalate, trioctyl phosphate, tributyl phosphate, tributyl citrate, polyethylene glycol, polypropylene glycol, etc.), visible image area of developer Acridine dye, cyanine dye, as a coloring substance for visualization
Pigments such as styryl dyes, triphenylmethane dyes and phthalocyanines, and other general stabilizers for diazo resins (phosphoric acid, phosphorous acid, pyrophosphoric acid, oxalic acid, boric acid, p-
Toluenesulfonic acid, benzenesulfonic acid, p-hydroxybenzenesulfonic acid, 2-methoxy-4-hydroxy-5-benzoyl-benzenesulfonic acid, malic acid,
Tartaric acid, dipicolinic acid, polyacrylic acid and its copolymer, polyvinylphosphonic acid and its copolymer, polyvinylsulfonic acid and its copolymer, 5-nitronaphthalene-1-phosphonic acid, 4-chlorophenoxymethylphosphonic acid, sodium Phenyl-methyl-pyrazolone sulfonate, 2-phosphonobutane tricarboxylic acid-1,2,4,1
-Phosphonoethanetricarboxylic acid-1,2,2,1-hydroxyethane-1,1-disulfonic acid, etc.) can be added. The addition amount of these additives is different depending on the intended purpose, but generally 0 to the total solid content of the photosensitive layer.
It is 5 to 30% by weight.

VIII. Photosensitive lithographic printing plate The photosensitive composition of the present invention is dissolved in a suitable organic solvent and coated on a support having a hydrophilic surface so that the dry coating weight is 0.5 to 5 g / m ² , A lithographic printing plate can be obtained. The concentration of the photosensitive composition at the time of coating is preferably in the range of 1 to 50% by weight. As the coating solvent used, methyl cellosolve, ethyl cellosolve, 1-methoxy-2-propanol, methyl cellosolve acetate, acetone, methyl ethyl ketone, methanol, dimethylformamide, dimethyl sulfoxide, ethylene dichloride, diclohexanone, dioxane, tetrahydrofuran Etc. can be mentioned. A mixed solvent of these or a mixed solvent obtained by adding a small amount of water, a solvent such as toluene, which does not dissolve the diazo resin, or the polymer compound to the mixed solvent, is also suitable. When the photosensitive solution dissolved in these solvents is applied and dried, it is desirable to dry at 50 ° C to 120 ° C. As a drying method, the temperature may be lowered at the beginning and pre-dried and then dried at a high temperature, or may be directly dried at a high temperature by selecting an appropriate solvent and concentration.

A lithographic printing plate having a photosensitive layer coated on a support having a hydrophilic surface is exposed with an image and then developed with a developer containing weak alkaline water to obtain a negative relief image with respect to the original image. Suitable light sources for exposure include carbon arc lamps, mercury lamps, xenon lamps, metal halide lamps,
Examples include strobes and ultraviolet laser beams. As a developing solution for a photosensitive lithographic printing plate having a photosensitive layer of the present invention, each of JP-A-51-77401, JP-A-51-80228, JP-A-53-44202 and JP-A-55-52054 is used. Organic solvents having a solubility in water of 10% by weight or less at room temperature as described in the publication (benzyl alcohol, ethylene glycol monophenyl ether, etc.), alkaline agents (triethanolamine, monoethanolamine, etc.), anionic surfactants (Aromatic sulfonate, dialkyl sulfosuccinate, alkyl naphthalene sulfonate, A weak alkaline aqueous solution consisting of branched alkyl sulfate ester salt, etc.), water and, if necessary, an antifouling agent (sodium sulfite, sodium salt of sulfopyrazolone, etc.) and a water softener (ethylenediaminetetraacetic acid 4Na, NCH ₂ COONa) ₃ ) Can be done.

As the support having a hydrophilic surface to which the photosensitive composition of the present invention is applied, a hydrophilized aluminum plate is particularly preferable. The surface of the aluminum plate is wire brush graining, brush graining with a nylon brush while pouring a slurry of abrasive particles, ball graining, chemical graining, electrolytic graining and a combination of these graining methods. After graining the surface with the performed composite graining, if necessary, anodize with sulfuric acid, phosphoric acid, oxalic acid, boric acid, chromic acid, sulfamic acid or mixed acid of these with direct current or alternating current power source to make aluminum surface. Those provided with a strong passivation film are preferable.
The aluminum surface is hydrophilized by such a passivation film itself, but if necessary, the silicate treatment (sodium silicate, silica, etc.) described in U.S. Pat. No. 2,714,066 or U.S. Pat. Acid potassium), the potassium fluorozirconate treatment described in U.S. Pat. No. 2,946,638, the phosphomolybdate treatment described in U.S. Pat. No. 3201247, and the German Patent No. 1091433. Polyacrylic acid treatment, German patent 11
Polyvinylphosphonic acid treatment described in 34093 and British Patent 1230447, phosphonic acid treatment described in JP-B-44-6409, phytic acid described in U.S. Pat. No. 3,307,951. Treatment, JP-A-58-168
No. 93 and Japanese Patent Application Laid-Open No. 58-18291, a composite treatment comprising a hydrophilic organic polymer compound and a divalent metal, and a sulfonic acid group described in Japanese Patent Application Laid-Open No. 59-101651. Those which have been hydrophilized by the undercoat of a water-soluble polymer having is particularly preferable. As another hydrophilic treatment method, silicate electrodeposition described in US Pat. No. 3658662 can also be mentioned.

〔The invention's effect〕

The photosensitive composition of the present invention is alkali-developable and has high inking property. Therefore, the photosensitive composition of the present invention,
It is suitable for producing a photosensitive printing plate and can be widely used as a photosensitive lithographic printing plate coated with a photosensitive composition.

Hereinafter, the present invention will be described in more detail based on examples.

Examples 1 to 5 and Comparative Example 1 Synthesis Example of Copolymer In a 500 ml three-necked round bottom flask equipped with a condenser and a stirrer, 125 g of 4,4'-diphenylmethane diisocyanate was added.
(0.50 mol) and 67 g (0.50 mol) of 2,2-bis (hydroxymethyl) propionic acid were added and dissolved in 290 ml of dioxane. 1 g of N, N-diethylaniline was added as a catalyst, and the mixture was heated under reflux for 6 hours with stirring. Then, the reaction solution was poured into a solution of 4 l of water and 40 ml of acetic acid while stirring to precipitate a white polymer. This polymer was separated by filtration, washed with water, and dried under vacuum to obtain 185 g of a polymer.

Weight average (polystyrene standard) when molecular weight was measured by gel permeation chromatography (GPC)
It was 28,000. Further, the carboxyl group content measured by titration was 2.47 meq / g.

Further, 40 g of the obtained polymer was placed in a 300 ml three-necked round bottom flask equipped with a condenser and a stirrer, and dissolved with DMF 200 ml. 6.3 g (0.062 mol) of triethylamine was added to this solution, and after heating to 80 ° C, 7.7 g of ethylene bromohydrin
(0.062 mol) was added dropwise with stirring over 10 minutes. Then, stirring was continued for 2 hours.

After completion of the reaction, the reaction solution was poured into a solution of water (4 L) and acetic acid (200 mL) with stirring to precipitate a white polymer. The polymer was separated by filtration, washed with water, and dried under vacuum to obtain 42 g of a polymer.

It was confirmed by NMR measurement that a hydroxyethyl group had been introduced into the carboxyl group, and the residual carboxyl group content was measured by titration to find that it was 1.21 meq / g (polymer (a)).

Next, attach a 0.24 mm thick aluminum plate with a nylon brush and 40
The surface was grained with an aqueous 0 mesh mesh of pumice and then washed well with water. This was immersed in a 10% aqueous sodium hydroxide solution at 70 ° C. for 60 seconds for etching, washed with running water, and neutralized with 20% nitric acid, and then the method disclosed in JP-A-53
-67507, Electrochemical surface roughening method, that is, V _A = 12.7
Using a sinusoidal alternating waveform current of V, V _C = 9.1 V, electrolytic surface roughening treatment was performed in a 1% aqueous nitric acid solution at an anode-time electricity quantity of 160 coulomb / dm ² . Continue to soak in a 30% sulfuric acid solution
After desmutting at 55 ° C. for 2 minutes, anodizing treatment was performed in a 7% aqueous solution of sulfuric acid to a thickness of 2.0 g / m ² . Then 7
It was immersed in a 3% aqueous solution of sodium silicate at 0 ° C. for 1 minute, washed with water and dried. The aluminum plate obtained as described above was coated with the following photosensitive solution on a wheeler and dried at 80 ° C. for 2 minutes. The coating weight was 2.0 g / m ² .

Photosensitive solution 4- (n-dodecyl) benzenesulfonate 1.0 g of a condensate of 4-diazodiphenylamine and formaldehyde
Polymer (a) 5.0 g Copolymer shown in Table 1 0.1 g Malic acid 0.05 g FC-430 (Fluorine type surfactant manufactured by 3M Company USA) 0.05 g 2-Methoxyethanol 100 g These photosensitive lithographic printing plates were used. , Fuji Photo Film Co., Ltd.
Image exposure for 1 minute from a 1m distance with a PS light manufactured by PS, and a volume ratio of automatic processor 800EBII manufactured by the same company and developer DN-3C manufactured by the same as 1: 2.
Development and gumming treatment were performed at 25 ° C. for 50 seconds using a (water) diluted solution and a water diluted solution of GUM FN-2 manufactured by the same company at a volume ratio of 1: 1. In addition, another lithographic printing plate was prepared in the same manner except that it did not contain a copolymer. Next, one week after processing these planographic printing plates, GT made by Heidelberg
The results are shown in Table 1 after checking the ink receptivity by the number of prints until the ink was completely transferred to the printing paper by using an O printing machine.

Examples 6 to 10 and Comparative Example 2 The aluminum plate treated in the same manner as in Examples 1 to 5 was coated with the following photosensitive solution using a wheeler and dried at 100 ° C for 2 minutes. The coating weight was 1.5 g / m ² .

Photosensitizing solution Hexafluorophosphate salt of a condensate of 4-diazodiphenylamine and formaldehyde 1.0 g 2-hydroxyethyl methacrylate / acrylonitrile / methyl methacrylate / methacrylic acid quaternary copolymerization described in Example 1 Combined 5.0 g Copolymer described in Table 2 0.2 g Malic acid 2-methoxyethanol 100 g These photosensitive lithographic printing plates were exposed, developed and gummed in the same manner as in Examples 1-5. In addition, another lithographic printing plate was prepared in the same manner except that it did not contain a copolymer. These planographic printing plates were used in Examples 1 to 5
The inking property was examined in the same manner as. The results are shown in Table 2.

Comparative Example 3 In the same manner as in Example 1, a copolymer represented by the following formula, which does not contain stearyl acrylate (structural unit i)), was synthesized, and a lithographic printing plate was prepared using the copolymer. I investigated the sex. The number of incarnations was 20.

Comparative Example 4 In the same manner as in Example 1, a copolymer represented by the following formula containing no methoxytriethylene glycol (structural unit iii)) was synthesized.

Since this copolymer did not dissolve in the coating liquid, unevenness was generated on the photosensitive film, and further experiments could not be performed.

As is clear from these examples, the lithographic printing plate using the photosensitive composition of the present invention is very excellent in inking property.

 ─────────────────────────────────────────────────── --- Continuation of the front page (56) Reference JP-A-54-135004 (JP, A) JP-A-57-178242 (JP, A) JP-A-57-40249 (JP, A) JP-A-62- 36657 (JP, A) JP 59-137943 (JP, A) JP 62-170950 (JP, A) JP 62-226143 (JP, A)

Claims (1)

[Claims] 1. A photosensitive composition for a lithographic printing plate comprising a photosensitive diazo resin and a polymer binder, further comprising i) an alkyl group having 4 or more carbon atoms, a substituted alkyl group, an aralkyl group, a substituted aralkyl group and aryl. Group or acrylate or methacrylate having a substituted aryl group, i
i) Acrylate or methacrylate having 3 to 20 carbon atoms, containing 30% by weight or more of fluorine, and having a fluoroaliphatic group (Rf group) having at least three terminal carbon atoms fully fluorinated. Iii) A sensitizer for a lithographic printing plate containing a copolymer containing at least one of oxyalkylene acrylate, poly (oxyalkylene) acrylate, oxyalkylene methacrylate or poly (oxyalkylene) methacrylate as a structural unit. Sex composition.