JP2003195526A - Method for platemaking of photosensitive lithographic printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for platemaking of a photosensitive lithographic printing plate having significantly improved image strength and particularly excellent printing durability in the initial stage of printing. <P>SOLUTION: The method for platemaking of the photosensitive lithographic printing plate, in which, after exposing a photosensitive lithographic printing plate having a photopolymerizable photosensitive layer containing ethylenic monomers, a photopolymerization initiator and a polymer binder formed on a supporting body to laser light; developing; cleaning with water; and applying a gum liquid, are successively carried out, is characterized in that a step of drying the printing plate is carried out in a process between the cleaning process and the application process of the gum liquid. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for printing a photosensitive lithographic printing plate, and more particularly to an image forming method advantageous for producing a printing plate.

[0002]

2. Description of the Related Art In recent years, with the development of image forming technology, a highly sensitive photosensitive material has been demanded, and a photopolymer having high sensitivity is considered promising. In particular, there is a high demand for laser scanning exposure, which can be expected to greatly improve productivity. Examples of the laser light source include Ar laser, FD-YAG laser, Violet laser, semiconductor laser, and YAG laser. Among them, the visible light laser A
r laser 488 nm light, FD-YAG laser 5
Violet lasers around 32 nm and 405 nm, infrared semiconductor lasers oscillating at 830 nm, etc. are considered promising.

[0003]

In such a photopolymerizable photoreceptor, high sensitivity is a very important performance,
Many photoconductors utilizing radical polymerization, which are advantageous for high sensitivity, have been researched and developed. However, the sensitivity of the photosensitive layer is still insufficient, and it has been difficult to print a sufficient number of sheets on a printing machine only by performing ordinary development processing after performing exposure by high-speed laser scanning.

On the other hand, attempts have been made to improve the intensity of the obtained image by improving the processing method after laser scanning exposure. Specifically, there are known a method of performing a heat treatment immediately after laser scanning exposure and then performing a development treatment, and a treatment method of exposing the entire surface after the development treatment. However, such a method has not yet obtained sufficient performance in terms of image density and printing durability at the time of printing.

An object of the present invention is to provide a processing method for giving an image obtained by scanning exposure of a laser in a light-sensitive material to give an image strength which can sufficiently endure printing.

[0006]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that a printing plate provided with a photosensitive layer on a support is subjected to scanning exposure with a laser, development, washing with water and coating with a gum solution. It was found that when the printing plate was dried before the gum solution applying step when the steps were sequentially performed, the image strength at the time of printing was remarkably increased, and the present invention was reached.

Interplate automatic developing machine (G &
Conventionally, as seen in the J. company) and the Stablon automatic developing machine (Fuji Photo Film Co., Ltd.), the gum solution is applied as it is by squeegeeing the water on the plate surface with a roller after the washing process following the developing process. The present invention is characterized in that the gum solution is applied after the printing plate is dried after washing with water. That is, the gist of the present invention is to develop a photosensitive lithographic printing plate provided with a photopolymerizable photosensitive layer containing an ethylenic monomer, a photopolymerization initiator and a polymer binder on a support, after laser exposure. In the method for printing a photosensitive lithographic printing plate, which comprises sequentially performing a step, a water washing step, and a gum solution coating step, a photosensitive lithographic plate characterized by performing a drying treatment of the printing plate between the water washing step and the gum solution coating step. The method of printing a printing plate.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. The photopolymerizable photosensitive layer of the present invention, as its component,
It contains (A) an ethylenic monomer, a photopolymerization initiator, specifically (B) a sensitizing dye, (C) a radical generator, and (D) a polymer binder.

Description of (A) Ethylenic Monomer The (A) ethylenic monomer used in the present invention is a compound having one or more ethylenic double bonds, and a compound having one ethylenic double bond. Examples thereof include (meth) acrylic acid, alkyl esters of (meth) acrylic acid, acrylonitrile, styrene, and monoesters of carboxylic acid having one ethylenically unsaturated bond and poly (mono) hydric alcohol. It is desirable to contain a polyfunctional ethylenic compound having two or more ethylenic double bonds in one molecule as an ethylenic monomer.

Examples of such polyfunctional ethylenic compounds include, for example, esters of aliphatic polyhydroxy compounds and unsaturated carboxylic acids; esters of aromatic polyhydroxy compounds and unsaturated carboxylic acids; aliphatic polyhydroxy compounds, aromatics. Examples thereof include esters obtained by an esterification reaction of a polyvalent hydroxy compound such as a group polyhydroxy compound with an unsaturated carboxylic acid and a polyvalent carboxylic acid.

The ester of the aliphatic polyhydroxy compound and the unsaturated carboxylic acid is not limited, but includes ethylene glycol diacrylate, triethylene glycol diacrylate, trimethylolpropane triacrylate, trimethylolethane triacrylate, pentaerythritol diacrylate, Acrylic esters of aliphatic polyhydroxy compounds such as pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate glycerol acrylate, etc. Methacrylic acid ester in which the acrylate of the exemplified compound is replaced with methacrylate Le similarly itaconic acid ester instead itaconate, maleic acid esters, and the like was replaced with crotonic acid ester or maleate was replaced Kuroneto.

Examples of the ester of an aromatic polyhydroxy compound and an unsaturated carboxylic acid include acrylic acid esters of aromatic polyhydroxy compounds such as hydroquinone diacrylate, hydroquinone dimethacrylate, resorcin diacrylate, resorcin dimethacrylate and pyrogallol triacrylate. Examples thereof include methacrylic acid ester.

The ester obtained by the esterification reaction of unsaturated carboxylic acid, polyvalent carboxylic acid and polyvalent hydroxy compound is not necessarily a single substance, but representative specific examples include acrylic acid, phthalic acid, and Examples thereof include condensates of ethylene glycol, acrylic acid, maleic acid, and diethylene glycol, methacrylic acid, terephthalic acid and pentaerythritol, acrylic acid, adipic acid, butanediol and glycerin.

Other examples of the polyfunctional ethylenic monomer used in the present invention include a polyisocyanate compound and a hydroxyl group-containing (meth) acrylic acid ester or a polyisocyanate compound and a polyol and a hydroxyl group-containing (meth) acrylic acid ester. Urethane (meth) acrylates obtained by reaction; epoxy acrylates such as addition reaction products of polyvalent epoxy compounds with hydroxy (meth) acrylate or (meth) acrylic acid: acrylamides such as ethylenebisacrylamide; Allyl esters such as diallyl phthalate; vinyl group-containing compounds such as divinyl phthalate are useful.

Of these polyfunctional ethylenic monomers, it is desirable to contain urethane (meth) acrylates.
Further, as a preferable ethylenic monomer used in the present invention, a phosphoric acid ester compound containing at least one (meth) acryloyl group (hereinafter, abbreviated as "phosphoric acid ester compound") can be mentioned. When the ester compound is contained, it is particularly useful in terms of printing durability and improvement of non-printing area removal. The compound is not particularly limited as long as it is a compound in which at least a part of the hydroxyl groups of phosphoric acid is esterified and has a (meth) acryloyl group, but specifically, for example, the following general formula (Ia), ( I
The compound shown by b) is mentioned.

[0016]

[Chemical 1]

(In the general formulas (1) and (2), R ¹ and R ¹ '
Each independently represent a hydrogen atom or a methyl group, and n is 1 to 2
5 represents an integer of 5 and m represents an integer of 1 to 3. ) In the compounds represented by the general formulas (1) and (2), n is 1 to
Those of 10, especially 1 to 4, are particularly preferred. Among the compounds represented by the general formulas (1) and (2), specific examples of particularly preferable compounds include methacryloxyethyl phosphate, bis (methacryloxyethyl) phosphate, and methacryloxyethylene glycol phosphate. Etc.

The phosphoric acid ester compound used in the present invention may be a single compound or a mixture of a plurality of compounds. When the phosphoric acid ester compound is contained, the content thereof is preferably 1 to 60% by weight, and particularly preferably 5 to 50% by weight in the ethylenic monomer. (Photopolymerization Initiator) (B) Description of Sensitizing Dye Next, the sensitizer of the photopolymerization initiator will be described. The sensitizer in the present invention means a compound which, when coexisted with the above-mentioned radical generator, allows the radical generator to effectively generate active radicals by light irradiation, preferably visible light irradiation. .

(Sensitizer suitable for visible light) First, A at 488 nm
Examples of sensitizers particularly suitable for visible light lasers such as r lasers and 532 nm FD-YAG lasers include leuco crystal violet and leucomalachite disclosed in, for example, US Pat. No. 3,479,185. Triphenylmethane-based leuco dyes such as green, photoreducing dyes such as erythrosine and eosin Y, US Pat.
49,367, U.S. Pat. No. 3,652,275.
U.S. Pat. No. 4,162,162, aminophenyl ketones such as Michler's ketone and aminostyryl ketone disclosed in U.S. Pat. No. 3,842,790, .beta.-diketones shown in U.S. Pat. No. 3,844,790, U.S. Pat. Indanones found in the specification, ketocoumarins disclosed in JP-A-52-112681, aminostyrene derivatives and aminophenylbutadiene derivatives disclosed in JP-A-59-56403, and U.S. Pat. No. 4,594. , 310, the aminophenyl heterocycles shown in US Pat. No. 4,966,830, the julolidine heterocycles shown in US Pat. No. 4,966,830, and the pyrromethene dyes shown in JP-A-5-241338. .

Among these, particularly, JP-A-6-30120
8, JP-A-8-146605 and JP-A-8-21160
5, JP-A-8-129258, JP-A-8-129259
A coumarin-based dye as described in JP-A-7-5685,
Pyrromethene dyes as described in Japanese Patent Application No. 10-144242 are preferred. (Sensitizer suitable for Violet laser (near 405 nm))
Suitable sensitizing dyes for Violet laser include 390-4
There is no particular limitation as long as it is a compound that absorbs light having a wavelength of 30 nm and efficiently generates radicals from the radical generator by interacting with the radical generator, but dialkylaminobenzene compounds are preferable. The dialkylaminobenzene-based compound has a dialkylaminobenzene structure and may have any substituent. Among them, the dialkylaminobenzophenone-based compound and the carbon at the p-position with respect to the amino group on the benzene ring are included. A dialkylaminobenzene compound having an aromatic heterocyclic group as a substituent at an atom, and an alkyl group constituting the dialkylamino group of these compounds are bonded to each other, and / or the alkyl group is an amino group on the benzene ring. Compounds having a structure in which a nitrogen-containing heterocyclic structure is formed by bonding to a carbon atom adjacent to the carbon atom to which is bonded are preferred. In the above, the amino groups constituting the dialkylamino group may be the same or different and preferably have 1 to 6 carbon atoms.

Among them, the preferable dialkylaminobenzene compounds are represented by the following general formulas (II) and (III).

[0022]

[Chemical 2]

(In the formula, R ^{2 to} R ⁵ each independently represent an alkyl group having 1 to 6 carbon atoms, and R ^{6 to} R ⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. , R ² and R
³ , R ⁴ and R ⁵ , R ² and R ⁶ , R ³ and R ⁷ , R ⁴ and R ⁸ , and R ⁵ and R ⁹ may be independently bonded to form a ring. )

[0024]

[Chemical 3]

(In the formula, R ¹⁰ and R ¹¹ each independently represent an alkyl group having 1 to 6 carbon atoms, and R ¹³ and R ^{14 each} independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; Is S,
O, dialkylmethine or

[0026]

[Chemical 4]

R ¹⁵ is a hydrogen atom or carbon 1 to 6
Is an alkyl group. However, R ¹⁰ and R ¹¹ , R ¹⁰ and R ¹³ or R ¹¹ and R ¹⁴ may be independently bonded to form a ring. The carbon number of the alkyl group of dialkylmethylene is 1 to 6, preferably 1.

When any of R ^{2 to} R ^{14 in} the formulas (II) and (III) is combined to form a ring, it is preferably a 5- or 6-membered ring, and particularly preferably a 6-membered ring. Examples of the compound represented by the general formula (II) include 4,4'-dimethylaminobenzophenone, 4,4'-diethylaminobenzophenone and compounds having the following structures.

[0029]

[Chemical 5]

The compound represented by the general formula (III) includes 2- (p-dimethylaminophenyl) benzoxazole and 2- (p-diethylaminophenyl).
Benzoxazole, 2- (p-dimethylaminophenyl) benzo [4,5] benzoxazole, 2- (p-
Dimethylaminophenyl) benzo [6,7] benzoxazole, 2,5-bis (p-diethylaminophenyl) 1,3,4-oxazole, 2- (p-dimethylaminophenyl) benzothiazole, 2- (p-diethylamino) Examples thereof include phenyl) benzothiazole, 2- (p-dimethylaminophenyl) benzimidazole, 2- (p-diethylaminophenyl) benzimidazole and compounds having the following structures.

[0031]

[Chemical 6]

As the compounds other than the formulas (II) and (III),
2,5-bis (p-diethylaminophenyl) 1,3
4-thiadiazole, (p-dimethylaminophenyl)
Pyridine, (p-diethylaminophenyl) pyridine,
2- (p-dimethylaminophenyl) quinoline, 2-
(P-diethylaminophenyl) quinoline, 2- (p-
Examples thereof include dimethylaminophenyl) pyrimidine and 2- (p-diethylaminophenyl) pyrimidine.

(Sensitizer Suitable for Infrared Laser) Further, as an example of a sensitizer suitable for an infrared laser in the vicinity of 830 nm or 1016 nm, for example, it is excited when receiving light irradiation in the range of 650 to 1300 nm. It is a compound that plays a role of (electron transition) and transfers the electronic transition energy to the radical generator of the component (C). Such a sensitizing dye is 650 to 1
Any compound can be used as long as it is a compound that undergoes electronic transition by irradiation with light in the range of 300 nm.

In the present invention, these dyes include
The basic structure is a structure in which a hetero atom such as a nitrogen atom, an oxygen atom, or a sulfur atom is bound by a polymethine (-CH =) _n chain. Typically, the hetero atom forms a hetero ring. , A so-called cyanine dye in a broad sense having a structure in which a heterocycle is bound via a polymethine chain, specifically, for example, a quinoline dye (so-called cyanine dye), an indole dye (so-called indocyanine dye) , Benzothiazole-based (so-called thiocyanine-based), pyrylium-based, thiapyrylium-based, squarylium-based, croconium-based, azurenium-based, etc., and so-called polymethine dyes having a structure in which an acyclic heteroatom is bonded via a polymethine chain, etc. Among them, cyanine dyes such as quinoline dyes, indole dyes, benzothiazole dyes, pyrylium dyes, thiapyrylium dyes, and polymers. Emissions-based dye is preferable.

In the present invention, among the above cyanine dyes, the quinoline dye is particularly preferably one of the following general formula (IV
Those represented by a), (IVb), or (IVc) are preferable.

[0036]

[Chemical 7]

[In the formulas (IVa), (IVb), and (IVc), R¹⁶Over
And R¹⁷Are each independently an optionally substituted group.
Alkyl group, optionally substituted alkenyl group,
An alkynyl group which may have a substituent or a substituent
Represents a phenyl group which may be¹Is (1) pigment content
Aether that resonates in the child to produce the oxonium cation
Thioate, which produces a sulfur bond or a sulfonium cation
And pen having at least a substituent having a le bond
Ta, hepta, nona, or undecamethine group, or
(2) the penta, hepta, nona, or undecametin
Having at least two substituents on the group, and the two substituents
Resonate in the dye molecule to produce the oxonium cation.
Generate ether bond or sulfonium cation
They are linked by a thioether bond to form a cyclic structure. The
Two on penta, hepta, nona, or undecamethine groups
The substituents of are linked to each other to form a cycloalkene having 5 to 7 carbon atoms.
Ring, cycloalkenone ring, cycloalkenedione ring,
Or, it may form a cycloalkene thione ring,
The norin ring may have a substituent, in which case
The two substituents are linked together to form a condensed benzene ring.
May be made. X _a ^-Represents a counter anion. ] Where R in formulas (IVa), (IVb), and (IVc)¹⁶And R
¹⁷When is an alkyl group, the carbon number is usually 1 to 1.
5, preferably 1 to 10, alkenyl group, alkynyl group
When it is, the number of carbon atoms is usually 2 to 15, preferably 2 to
10 and as those substituents including the phenyl group
Is an alkane having a carbon number of usually 1 to 15, preferably 1 to 10.
Coroxy, phenoxy, hydroxy, or phenyl
Groups and the like, L¹Or the ether bond in
As the substituent other than the substituent having an ether bond,
Same as above Alkyl, amino, or halogen atom with carbon number
And the like, and the substituent on the quinoline ring is the same.
Alkyl group with upper carbon number, alkoxy group with same carbon number,
A toro group, a halogen atom, etc. are mentioned.

As the indole and benzothiazole dyes, those represented by the following general formula (V) are particularly preferable.

[0039]

[Chemical 8]

[In the formula (V), Y ¹ and Y ² each independently represent a dialkylmethylene group or a sulfur atom, and R ¹⁸
And R ¹⁹ are each independently an alkyl group which may have a substituent, an alkenyl group which may have a substituent,
An alkynyl group which may have a substituent or a phenyl group which may have a substituent is shown, and L ² is a (1) substituent, which resonates in the dye molecule to generate an oxonium cation. Shows a tri, penta, hepta, nona, or undecamethine group having at least a substituent having an ether bond or a thioether bond for producing a sulfonium cation, or (2) at least 2 on the penta, hepta, nona, or undecamethine group Has one substituent,
The two substituents resonate in the dye molecule and are linked by an ether bond giving rise to an oxonium cation or a thioether bond giving rise to a sulfonium cation to form a cyclic structure. The two substituents on the penta, hepta, nona, or undecamethine group are linked to each other and have 5 to 7 carbon atoms.
May form a cycloalkene ring, a cycloalkene ring, a cycloalkenedione ring, or a cycloalkenethione ring, and the fused benzene ring may have a substituent, in which case two adjacent substituents May be linked to each other to form a condensed benzene ring. X _a ⁻ represents a counter anion. Here, the number of carbon atoms when R ¹⁸ and R ¹⁹ in the formula (V) are alkyl groups is usually 1 to 15, preferably 1 to 10,
When it is an alkenyl group or alkynyl group, it usually has 2 to 15 carbon atoms, preferably 2 to 10 carbon atoms, and the substituents thereof, including the phenyl group, usually have 1 to 1 carbon atoms.
5, preferably 1 to 10 alkoxy groups, phenoxy groups, hydroxy groups, phenyl groups and the like, L ²
Examples of the substituent other than the substituent substituted by the ether bond or the thioether bond in, include an alkyl group having the same carbon number as above, an amino group, a halogen atom, etc., and the substituent in the condensed benzene ring may have the same carbon number as above. The alkyl group, the alkoxy group having the same carbon number as above, the nitro group, the halogen atom and the like.

As the pyrylium-based and thiapyrylium-based dyes, particularly, the following general formulas (VIa), (VIb), or (V
Those represented by Ic) are preferred.

[0042]

[Chemical 9]

[In the formulas (VIa), (VIb), and (VIc), Z ¹ and Z ² each independently represent an oxygen atom or a sulfur atom,
R ²⁰ , R ²¹ , R ²² and R ²³ are each independently a hydrogen atom or an alkyl group, or R ²⁰ and R ²¹ , and R ²²
And R ²³ may be linked to each other to form a cycloalkene ring having 5 or 6 carbon atoms, and L ³ is a (1) substituent, which is an ether bond which resonates in the dye molecule to generate an oxonium cation. , Or a mono-, tri-, penta-, or heptamethine group having at least a substituent having a thioether bond that produces a sulfonium cation, or (2) at least two substituents on the penta, hepta, nona, or undecamethine group. And the two substituents are resonated in the dye molecule to be linked by an ether bond giving an oxonium cation or a thioether bond giving a sulfonium cation to form a cyclic structure. Two substituents on the tri, penta, or heptamethine group may be linked to each other to form a cycloalkene ring having 5 to 7 carbon atoms, a cycloalkenone ring, a cycloalkenedione ring, or a cycloalkenethione ring. The pyrylium ring and thiapyrylium ring may have a substituent, and in this case, two adjacent substituents may be linked to each other to form a condensed benzene ring. X _a ⁻ represents a counter anion. Here, R ²⁰ in the formulas (VIa), (VIb), and (VIc),
When R ²¹ , R ²² and R ²³ are alkyl groups, the number of carbon atoms is usually 1 to 15, preferably 1 to 10, L
Examples of the substituent other than the substituent substituted with the ether bond or the thioether bond in ^3, include an alkyl group having the same number of carbon atoms, an amino group, or a halogen atom,
Examples of the substituent on the pyrylium ring and thiapyrylium ring include an aryl group such as a phenyl group.

Further, as the polymethine dye, those represented by the following general formula (VII) are particularly preferable.

[0045]

[Chemical 10]

[In the formula (VII), R ²⁴ , R ²⁵ , R ²⁶ , and R
²⁷ independently represents an alkyl group, R ²⁸ and R ²⁹ each independently represents an aryl group which may have a substituent,
A furyl group or a thienyl group is shown, and L ⁴ is (1) as a substituent, and at least a substituent substituted with an ether bond producing an oxonium cation or a thioether bond producing a sulfonium cation, which resonates in the dye molecule. Having a mono, tri, penta, or heptamethine group, or (2) having at least two substituents on the penta, hepta, nona, or undecamethine group, wherein the two substituents are in the dye molecule. Resonating, they are linked by an ether bond giving rise to an oxonium cation or a thioether bond giving rise to a sulfonium cation to form a cyclic structure. Two substituents on the tri, penta, or heptamethine group may be linked to each other to form a cycloalkene ring having 5 to 7 carbon atoms, a cycloalkenone ring, a cycloalkenedione ring, or a cycloalkenethione ring. The quinone ring and the benzene ring may have a substituent. X _a
^- represents a counter anion. Here, the carbon number of the alkyl group of R ²⁴ , R ²⁵ , R ²⁶ , and R ²⁷ in the formula (VII) is usually 1 to 15, preferably 1 to 1
When 0, R ²⁸ and R ²⁹ are aryl groups, the number of carbon atoms is
Usually 6 to 20, preferably 6 to 15, R ²⁸ and R
Specific examples of ²⁹ include phenyl group, 1-naphthyl group, 2
-Naphthyl group, 2-furyl group, 3-furyl group, 2-thienyl group, 3-thienyl group, etc. are mentioned, and those substituents include alkyl groups having the same number of carbon atoms, alkoxy groups having the same number of carbon atoms, and dialkyl. An amino group, a hydroxy group, a halogen atom or the like can be mentioned, and as the substituent other than the substituent substituted by the ether bond or the thioether bond in L ⁴ , the same as the above, an alkyl group having an carbon number, an amino group, a halogen atom, etc. Examples of the substituent on the quinone ring and the benzene ring include an alkyl group having the same carbon number as above, an alkoxy group having the same carbon number as above, a nitro group, and a halogen atom.

The above general formulas (IVa to c), (V), and (VIa to
Specific examples of the counter anion X _a ⁻ in (c) and (VII) include Cl ⁻ , Br ⁻ , I ⁻ , and Cl.
^{_{O 4 -, PF 6 -,}} SbF 6 -, AsF 6 -, and, B
Inorganic acid anions such as inorganic boric acid such as F ₄ ⁻ and BCl ₄ ⁻ , benzenesulfonic acid, toluenesulfonic acid, naphthalenesulfonic acid, acetic acid, and methyl, ethyl, propyl, butyl, phenyl, methoxyphenyl,
Examples thereof include organic acid anions such as organic boric acid having an organic group such as naphthyl, fluorophenyl, difluorophenyl, pentafluorophenyl, thienyl and pyrrolyl.

Further, the sensitizing dye used in the present invention may be one which forms an inner salt. Examples of the sensitizing dye forming an inner salt include compounds represented by the following formula (VIII).

[0049]

[Chemical 11]

(In the formula (VIII), Y ¹ , Y ² , R ³⁰ , R
³¹ has the same meaning as in formula (V) above. Also,
L ⁴ represents a polymethine group selected from tri-, penta-, hepta-, nona-, or undecamethine, and a barbituric acid residue or a thiobarbituric acid residue represented by the following formula (VIII-2) on the polymethine group. Has a group. )

[0051]

[Chemical 12]

(In the formula (VIII-2), X represents an oxygen atom or a sulfur atom. R ³² and R ³³ are each independently a hydrogen atom or an alkyl group which may have a substituent, And an alkenyl group which may have a substituent, an alkoxy group which may have a substituent, or a phenyl group which may have a substituent.) The above general formulas (IVa to c) A quinoline-based dye represented by the formula, an indole-based or benzothiazole-based dye represented by the general formula (V), a pyranium-based or thiapyrylium-based cyanine dye represented by the general formula (VIa to c), and the general Among the polymethine dyes represented by the formula (VII), the indole or benzothiazole dyes represented by the general formula (V) are particularly preferable in the present invention.

Further, L ¹ , L ² , L ³ , and
And a polymethine chain including L ⁴ has a wavelength range of 700 to
A heptamethine chain for 850 nm, a nonamethine chain for a wavelength range of 850 to 950 nm, and an undecamethine chain for a wavelength range of 950 to 1300 nm are preferable. The photopolymerization initiator of the component (C) that constitutes the photopolymerizable composition of the present invention is a radical generator that generates active radicals when irradiated with light in the presence of the dye of the component (B). There are, for example, halogenated hydrocarbon derivatives, JP-A-62-
143044, JP-A-62-150242, JP-A-9-188685, JP-A-9-188686, JP-A-9-188710 and JP-A-27664769, and Kunz, Martin "Rad Tech '. 98.Proceeding Ap
ril 19-22, 1998, Chicago "and the like, organoborates, JP-A-59-152396, JP-A-61-151.
No. 197, the titanocene compound described in each publication, the hexaarylbiimidazole compound described in Japanese Examined Patent Publication No. 6-29285, and the like, diaryl iodonium salts, organic peroxides, and the like. In the present invention, Halogenated hydrocarbon derivatives and organoborates are preferred.

(Banding inhibitor) Further, 650n
It is desirable to further contain a banding inhibitor that absorbs light of m to 1300 nm. The banding inhibitor as used herein is a compound having an absorption range in the above range. The function of the banding inhibitor in the present invention is estimated as follows.

In the photopolymerizable composition capable of forming an image with infrared light, the amount of the sensitizing dye is usually set so that the photopolymerizable composition exhibits the highest sensitivity. Here, the amount of the sensitizing dye showing the highest sensitivity in the photopolymerizable composition is the amount ratio of (A) an ethylenic monomer, (C) a radical generator, and other components contained in the photopolymerizable composition. Can be determined by measuring the sensitivity while keeping the value constant and changing only the amount ratio of the sensitizing dye.

The sensitizing dye is usually distributed almost evenly in the photopolymerizable composition (in the case of the photopolymerizable lithographic printing plate, the photopolymerizable composition layer), and the photopolymerizable composition has the highest sensitivity. It is considered that when the amount of the sensitizing dye showing is, the irradiated light is almost entirely absorbed by the sensitizing dye and represents the maximum sensitizing effect. When the amount of the sensitizing dye is too small, the irradiated light cannot be completely absorbed by the sensitizing dye before reaching the deepest part of the photopolymerizable composition layer, and the efficiency is lowered. On the other hand, if the sensitizing dye is too much, all the irradiation light is absorbed by the sensitizing dye present on the surface portion of the photopolymerizable composition layer,
The light does not reach the deep part of the photopolymerizable composition layer, so that the photopolymerization does not occur in the deep part and the sensitivity is rather lowered.

Therefore, the amount of the sensitizing dye is usually set so that the photopolymerizable composition exhibits the highest sensitivity. However, in the case of the photopolymerizable composition, the sensitivity is so high that it may cause a problem of being exposed to the leaked light emitted from the laser. Although the cause of the leaked light of the laser is not clear, despite the fact that the light of about 1/10 of the normal light intensity is received from the end of the laser light irradiation device, it should not be irradiated with the laser light. , Is a phenomenon of irradiation toward the printing plate surface.

Since leakage light is considerably weaker than usual exposure intensity, absorption by a light absorber in the photopolymerizable composition can prevent polymerization due to leakage light. here,
A substance that absorbs light of 650 to 1300 nm is referred to as a banding inhibitor, which also absorbs ordinary laser light, so that the sensitivity of the photopolymerizable composition is reduced accordingly. Therefore, if the amount of the banding inhibitor is too large, the sensitivity is lowered too much and image formation becomes difficult. Therefore, the total amount of the banding inhibitor and the sensitizing dye is usually 110% to 1000% of the maximum sensitivity. Yes, preferably 110% ~
It is 500%, and more preferably 110% to 250%.

By blending in this way, the decrease in sensitivity due to ordinary laser exposure can be minimized, and
Photopolymerization due to leaked light can be prevented. Such a banding inhibitor is a compound capable of absorbing light in the range of 650 nm to 1300 nm, that is, 650 nm.
Any compound can be used as long as it has an absorption region in a part or all of the range of 1300 nm, but from the viewpoint of absorption efficiency, it is preferable to include a compound having a maximum absorption in 650 to 1300 nm.

From a practical point of view, a compound that absorbs light having an exposure wavelength is preferable, and since the current laser exposure apparatus for image forming materials is 830 nm and 1016 nm, it absorbs any of these wavelengths. Those that do are preferred. Any compound having an absorption region in both of these can be used as an image forming material for any exposure wavelength. (C) Description of radical generator As the radical generator, any radical generator that can initiate the polymerization of the ethylenic monomer can be used. Among them, examples of the radical generator that generates an active radical by interacting with the photoexcited sensitizing dye (B) by some action include, for example, titanocenes, hexaarylbiimidazoles, halogenated hydrocarbon derivatives, and diaryl iodines. Known radical generators such as ordonium salts and organic peroxides can be mentioned.

(Visible light or violet laser (4
Radical Generator Suitable for Vicinity of 05 nm)) Examples of the radical generator suitable for visible light or violet laser include titanocene and hexaarylbiimidazole. Various types of titanocenes can be used. For example, JP-A-59-152396.
And various titanocenes described in JP-A-61-151197. More specifically, di-cyclopentadienyl-Ti
-Di-chloride, di-cyclopentadienyl-Ti-
Bis-phenyl, di-cyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluorophenyl-1-
Il, di-cyclopentadienyl-Ti-bis-2,
3,5,6-Tetrafluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,4,6-trifluorophen-1-yl, dicyclopentadienyl-T
i-2,6-di-fluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,4-di-fluorophen-1-yl, di-methylcyclopentadienyl-
Ti-bis-2,3,4,5,6-tetrafluorophen-1-yl, di-methylcyclopentadienyl-Ti
-Bis-2,6-difluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,6-difluoro-3- (pyr-1-yl) -phen-1-yl and the like. You can You may use these in combination of 2 or more types.

Examples of the hexaarylbiimidazoles include 2,2'-bis (o-chlorophenyl)-
4,4 ', 5,5'-Tetra (p-fluorophenyl)
Biimidazole, 2,2'-bis (o-bromophenyl) -4,4 ', 5,5'-tetra (p-iodophenyl) biimidazole, 2,2'-bis (o-chlorophenyl) -4 , 4 ', 5,5'-Tetra (p-chloronaphthyl) biimidazole, 2,2'-bis (o-chlorophenyl) -4,4'5,5'-tetra (p-chlorophenyl) biimidazole , 2,2'-bis (o-bromophenyl) -4,4 ', 5,5'-tetra (p-chloro-)
p-methoxyphenyl) biimidazole, 2,2′-bis (o-chlorophenyl) -4,4 ′, 5,5′-tetra (o, p-dichlorophenyl) biimidazole, 2,
2'-bis (o-chlorophenyl) -4,4'5,5 '
-Tetra (o, p-dibromophenyl) biimidazole, 2,2'-bis (o-bromophenyl) -4,4 '
5,5'-tetra (o, p-dichlorophenyl) biimidazole, 2,2'-bis (o, p-dichlorophenyl) -4,4'5,5'-tetra (o, p-di) Hexaarylbiimidazoles having halogen substituents on the benzene ring such as chlorophenyl) biimidazoles are preferred.

These hexaarylbiimidazoles can be used in combination with various kinds of biimidazoles, if necessary. Biimidazoles are, for example, Bul
l. Chem. Soc. Japan. 33,565 (1
960) and J. Org. Chem. 36 [16] 22
62 (1971) and can be easily synthesized.

(Radical generator suitable for infrared laser)
Radical generators suitable for infrared lasers are radical generators that generate active radicals when irradiated with infrared laser light in the coexistence of the component (B) with the dye.
For example, a halogenated hydrocarbon derivative, JP-A-62-14
3044, JP-A-62-150242, JP-A-9-
188,685, JP-A-9-188686, JP-A-9
No. 188710, Japanese Patent No. 2764769, etc., and Kunz, Martin "Rad Tech'98. Proceeding Apri.
l 19-22, 1998, Chicago ", etc.
JP-A-59-152396, JP-A-61-15119
No. 7, the titanocene compounds described in each publication, etc.
-29285 gazette etc. hexaaryl biimidazole compound, and a diaryl iodonium salt,
Examples thereof include organic peroxides, and halogenated hydrocarbon derivatives and organic borates are preferred in the present invention.

Here, the halogenated hydrocarbon derivative is preferably s-, in which at least one mono-, di-, or trihalogen-substituted methyl group is bonded to the s-triazine ring.
Triazine derivatives, specifically, for example, 2,4,6-
Tris (monochloromethyl) -s-triazine, 2,
4,6-tris (dichloromethyl) -s-triazine,
2,4,6-Tris (trichloromethyl) -s-triazine, 2-methyl-4,6-bis (trichloromethyl)
-S-triazine, 2-n-propyl-4,6-bis (trichloromethyl) -s-triazine, 2- (α,
α, β-trichloroethyl) -4,6-bis (trichloromethyl) -s-triazine, 2-phenyl--4,6
-Bis (trichloromethyl) -s-triazine, 2-
(3,4-epoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (p-chlorophenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- [1- (P-Methoxyphenyl) -2,4
-Butadienyl] -4,6-bis (trichloromethyl)
-S-triazine, 2-styryl-4,6-bis (trichloromethyl) -s-triazine, 2- (p-methoxystyryl) -4,6-bis (trichloromethyl) -s-
Triazine, 2- (p-i-propyloxystyryl)
-4,6-bis (trichloromethyl) -s-triazine, 2- (p-tolyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-methoxynaphthyl) -4,6- Bis (trichloromethyl) -s-triazine, 2-phenylthio-4,6-bis (trichloromethyl) -s-triazine, 2-benzylthio-4,6-
Bis (trichloromethyl) -s-triazine, 2,4
6-tris (dibromomethyl) -s-triazine, 2,
4,6-Tris (tribromomethyl) -s-triazine, 2-methyl-4,6-bis (tribromomethyl)-
Examples thereof include s-triazine and 2-methoxy-4,6-bis (tribromomethyl) -s-triazine. Among them,
2-methyl-4,6-bis (trichloromethyl) -s-
Triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, 2- (p-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (3,4- Epoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- [1-
(P-Methoxyphenyl) -2,4-butadienyl]-
4,6-bis (trichloromethyl) -s-triazine,
2- (p-methoxystyryl) -4,6-bis (trichloromethyl) -s-triazine, 2- (p-i-propyloxystyryl) -4,6-bis (trichloromethyl) -s-triazine and the like. Bis (trihalomethyl) -s
-A triazine compound is preferable because of its excellent stability over time.

Other halogenated hydrocarbon derivatives include, for example, JP-A-53-133428, JP-A-62-58241, and German Patent 333702.
No. 4, MPHutt, EFFlslager, LMWerbel "Jurn
Al of Heterocyclic Chemistry "Vol. 7, No. 3 (1970), etc. are also included. As the organic borate, those represented by the following general formula (IX) are particularly preferable.

[0067]

[Chemical 13]

[In Formula (IX), R ³⁴ , R ³⁵ , R ³⁶ , and R ³⁷
Are each independently an alkyl group which may have a substituent, an alkenyl group which may have a substituent, an alkynyl group which may have a substituent, and a substituent which may have a substituent. It represents a good aryl group or a heterocyclic group, which may be linked to each other to form a cyclic structure, and at least one of them is an alkyl group which may have a substituent. X _b ⁺ is a counter cation. Here, when R ³⁴ , R ³⁵ , R ³⁶ , and R ³⁷ in the formula (IX) are alkyl groups, the number of carbon atoms is usually 1 to 15, preferably 1 to 5, alkenyl group and alkynyl group. The carbon number at this time is usually 2 to 15, preferably 2 to 5, and the carbon number when it is an aryl group is usually 6 to 20, preferably 6 to 15,
The number of carbon atoms in the case of a heterocyclic group is usually 4 to 20, preferably 4 to 15, and examples of the substituent in these groups include a halogen atom, an alkyl group, an alkoxy group, a trifluoromethyl group, a trimethylsilyl group and the like. .

Specific examples of the organic boron anion of the organic boron salt represented by the formula (IX) include, for example, n-butyl-methyl-diphenylboron anion and n-butyl-
Triphenylboron anion, n-butyl-tris (2,
4,6-trimethylphenyl) boron anion, n-butyl-tris (p-methoxyphenyl) boron anion, n
-Butyl-tris (p-fluorophenyl) boron anion, n-butyl-tris (m-fluorophenyl) boron anion, n-butyl-tris (2,6-difluorophenyl) boron anion, n-butyl-tris (2 , 4,
6-trifluorophenyl) boron anion, n-butyl-tris (2,3,4,5,6-pentafluorophenyl) boron anion, n-butyl-tris (p-chlorophenyl) boron anion, n-butyl-tris (Trifluorophenyl) boron anion, n-butyl-tris (2,6-difluoro-3-pyrrolylphenyl) -boron anion, n-butyl-tris (3-fluoro-4-methylphenyl) -boron anion, etc. Can be mentioned.

The counter cation X _b ⁺ is, for example,
Onium compounds such as alkali metal cations, ammonium cations, phosphonium cations, sulfonium cations, and iodonium cations, and pyrylium cations, thiapyrylium cations, indolium cations, and the like can be given; organic ammonium cations such as tetraalkylammonium. Is preferred.

Among the above-mentioned component (C), the use of a bis (trihalomethyl) -s-triazine compound or an organic borate is particularly preferable because of its high sensitivity. In the present invention, in order to allow the dye of the component (B) and the organic borate as the photopolymerization initiator of the component (C) to be present in the photopolymerizable composition, the dye cation of the dye is appropriately selected. In addition to the usual method of blending a salt with a counter anion and a salt with an organic boron anion of the organic borate and an appropriately selected counter cation, a dye cation of the dye and an organic boron anion of the organic borate. It is also possible to employ a method of blending the salt formed with the above, and the latter method is preferable in the present invention.

(D) Description of Polymer Binder Next, the polymer binder (D) of the present invention will be described.
As a specific example, for example, (meth) acrylic acid, (meth) acrylic acid ester, (meth) acrylamide, maleic acid, (meth) acrylonitrile, styrene, vinyl acetate, vinylidene chloride, a homo- or copolymer such as maleimide, Other examples include polyethylene oxide, polyvinylpyrrolidone, polyamide, polyurethane, polyester, polyether, polyethylene terephthalate, acetyl cellulose, polyvinyl butyral and the like. As the polymer binder (D), a polymer binder having a carboxyl group in the molecule is preferable from the viewpoint of solubility in an alkaline developer, and among them, at least one type of (meth) acrylic acid ester and (meth) acrylic acid are used. A copolymer contained as a copolymerization component is preferable. The group constituting the ester of the (meth) acrylic acid ester is not particularly limited, but is generally an aliphatic or aromatic hydrocarbon group having about C _{1 to} C ₁₆ . The preferred acid value of the polymer binder having a carboxyl group in the molecule is 10 to 250, and the preferred weight average molecular weight (hereinafter abbreviated as Mw) is 5.
One thousand to one million. These polymer binders preferably have an unsaturated bond in their side chains, and particularly preferably have at least one unsaturated bond represented by the following general formulas (X-1) to (X-3).

[0073]

[Chemical 14]

(In the formula, R ³⁸ represents a hydrogen atom or a methyl group. R ^{39 to} R ⁴³ are each independently a hydrogen atom, a halogen atom, an amino group, a dialkylamino group, a carboxyl group, an alkoxycarbonyl group, Sulfo group, nitro group, cyano group, optionally substituted alkyl group, optionally substituted aryl group, optionally substituted alkoxy group, optionally substituted Optionally substituted aryloxy group, optionally substituted alkylamino group, optionally substituted arylamino group, optionally substituted alkylsulfonyl group, or substituent Z having an arylsulfonyl group which may have
Represents an oxygen atom, a sulfur atom, an imino group, or an alkylimino group. ) The methods for synthesizing such a polymer binder are roughly classified into the following two methods.

(Synthesis Method 1) A solution of a polymer binder having a carboxyl group in the molecule in an inert organic solvent (eg, alcohol-based, ester-based, aromatic hydrocarbon-based, aliphatic hydrocarbon-based, etc.). A method of synthesizing by reacting an epoxy group-containing unsaturated compound with a reaction condition of about 80 to 120 ° C. for about 1 to 50 hours. The proportion of the carboxyl group reacted with the epoxy group-containing unsaturated compound is not particularly limited as long as the effect of the present invention can be achieved, but it is preferable to react 5 to 90 mol% with respect to all the carboxyl groups, and more preferably Is 20 to 80 mol%, more preferably 30 to 70 mol%. Within the above range, the developability is good and the adhesiveness is good.

The epoxy group-containing unsaturated compound used for producing the ethylenic polymer binder having an unsaturated group in the side chain is
It is a compound having at least one unsaturated bond capable of addition polymerization and an epoxy group in one molecule. As the epoxy group-containing unsaturated compound, glycidyl (meth) acrylate, allyl glycidyl ether, α-ethyl glycidyl acrylate, crotonyl glycidyl ether, glycidyl crotonate, glycidyl isocrotonate, itaconic acid monoalkyl ester monoglycidyl ester, fumaric acid Aliphatic epoxy group-containing unsaturated compounds such as monoalkyl ester monoglycidyl ester and maleic acid monoalkyl ester monoglycidyl ester, and alicyclic epoxy group-containing unsaturated compounds represented by the following general formulas (X-4) to (X-17). Saturated compounds are mentioned.

[0077]

[Chemical 15]

[0078]

[Chemical 16]

(In each general formula, R ⁴⁴ represents a hydrogen atom or a methyl group. R ⁴⁵ represents a divalent aliphatic saturated hydrocarbon group having 1 to 6 carbon atoms. R ⁴⁶ represents 1 to 10 carbon atoms. It represents a divalent hydrocarbon group, and k represents an integer of 0 to 10.) Specific preferred examples of the epoxy group-containing unsaturated compound include glycidyl methacrylate, allyl glycidyl ether, and 3,4-epoxycyclohexylmethyl acrylate. Etc. Of these, particularly preferred compounds are allyl glycidyl ether and 3,4-epoxycyclohexyl methyl acrylate.

(Synthesis Method 2) One or more unsaturated bonds having low reactivity as shown by the general formulas (X-2) and (X-3) and unsaturated bond 1 having higher reactivity than these A method of synthesizing a compound having a total of two or more kinds of unsaturated bonds and an unsaturated carboxylic acid by copolymerization. General formula (X
As specific examples of the compound having an unsaturated group represented by -2), allyl (meth) acrylate, 3-allyloxy-2-hydroxypropyl (meth) acrylate, N,
N-diallyl (meth) acrylamide, cinnamyl (meth) acrylate, crotonyl (meth) acrylate,
Examples thereof include methallyl (meth) acrylate.

Specific examples of the compound having an unsaturated group represented by the general formula (X-3) include vinyl (meth) acrylate, vinyl crotonate, 1-propenyl (meth) acrylate and 1-chlorovinyl (meth). Acrylate,
2-phenyl vinyl (meth) acrylate, vinyl (meth) acrylamide, etc. are mentioned. These (X-
Among the compounds having the structures 2) and (X-3), preferred compounds include allyl (meth) acrylate and vinyl (meth) acrylate. By copolymerizing these monomers with an unsaturated carboxylic acid, preferably acrylic acid or methacrylic acid, a copolymer having the unsaturated group is obtained. The monomer to be copolymerized may be another monomer in addition to the unsaturated carboxylic acid, and examples thereof include alkyl acrylate, alkyl methacrylate, acrylonitrile, and styrene. Copolymerize (X-
The ratio of the compound having the structures 2) and (X-3) to the components of the whole polymer is 10 to 90 mol%, more preferably 30 to 80 mol%. If it is less than this range, the image reproducibility is poor, and if it is more than this range, the developability is poor.

(Use Ratio of Each Component in the Composition) The main constituent components of the photopolymerization composition used in the present invention have been described in detail above. The sensitizing dye (B) is preferably 0.01 to 20 parts by weight, particularly preferably 0.05 to 10 parts by weight, and the radical activator (C) is preferably 0.1 to 100 parts by weight of the monomer. -80 parts by weight, particularly preferably 0.5-
60 parts by weight, and (D) polymer binder is preferably 10
To 400 parts by weight, particularly preferably 20 to 200 parts by weight.

(Other Additives) The photopolymerizable composition of the present invention may contain other substances in addition to the above-mentioned essential components according to the purpose. For example, thermal polymerization inhibitors such as hydroquinone, p-methoxyphenol, and 2,6-di-t-butyl-p-cresol; coloring agents composed of organic or inorganic dyes and pigments; dioctyl phthalate, didodecyl phthalate, tricresyl. Plasticizer such as phosphate,
Sensitivity characteristic improvers such as tertiary amines and thiols, and other additives such as dye precursors can also be added.

Further, the photopolymerizable composition of the present invention may contain a surfactant as a coating property improving agent. Among them, the fluorine-based surfactant is particularly preferable. The preferable addition amount of the additives described above is 2 parts by weight or less of the thermal polymerization inhibitor, 20 parts by weight or less of the colorant, 40 parts by weight or less of the plasticizer, and 30 parts of the dye precursor with respect to 100 parts by weight of the ethylenic compound (A). It is in the range of not more than 10 parts by weight and not more than 10 parts by weight of surfactant.

The above-mentioned photopolymerizable composition is diluted with an appropriate solvent, coated on a support and dried to form a photosensitive layer, whereby an image forming material is obtained. The solvent is not particularly limited, for example, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate, acetone, methyl ethyl ketone, methanol, dimethylformamide, dimethyl sulfoxide, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, lactic acid. Methyl, ethyl lactate, cyclohexanone, diacetone alcohol, 4-hydroxy-2-butanone, methyldiglycol, water, or a mixture thereof is used.

(Description of Support) Although various metals can be used as the support in the present invention, an aluminum plate (including an aluminum alloy plate) is particularly preferable, and its thickness is usually about 0.01 to 10 mm, preferably 0.05-1m
It is about m. The surface of this support is roughened, then desmutted, and then anodized. In addition to this, degreasing treatment, sealing treatment, undercoating treatment, and the like may be performed as necessary. Usually, degreasing treatment is performed before the roughening treatment, but the degreasing treatment is a method of wiping with a solvent, dipping or steam cleaning, dipping with an alkaline aqueous solution, or spraying followed by neutralization with an acid aqueous solution. And a method of dipping or spraying with a surfactant.

The roughening treatment (graining treatment) is a mechanical treatment method such as a ball polishing method, a brush polishing method, a blast polishing method, a honing polishing method or a buff polishing method, or an electrolytic etching method or a chemical etching method. JI
The average roughness Ra defined in S B0601 is 0.1 to 0.1.
The thickness is about 1.5 μm, preferably about 0.2 to 1.0 μm. Of these, electrolytic etching with hydrochloric acid or nitric acid is particularly preferable.

Desmutting treatment is performed with sulfuric acid, nitric acid, hydrochloric acid,
Immersion or spraying with an acid such as phosphoric acid or chromic acid or an aqueous solution of alkali such as sodium hydroxide, potassium hydroxide, sodium metasilicate, sodium phosphate, sodium pyrophosphate, potassium phosphate or sodium aluminate It is done according to the usual methods. Although not particularly limited, as the degree of desmutting treatment, when the reflection density immediately after the roughening treatment step is A and the reflection density after the anodizing treatment step is B, A
It is desirable to set −B ≦ 0.1. This desmutting treatment is carried out to remove the smut on the surface of the support, which is generated by the roughening treatment, but in fact, this smut is largely concerned with the adhesiveness between the support and the photosensitive layer.

The reflection density is measured using a reflection densitometer in a visual mode without using a filter. The desmutting treatment which is the condition of the present invention depends on the alkaline aqueous solution used and the state of the roughening treatment, but for example, 1 to 10 for a NaOH aqueous solution having a concentration of 0.1 to 4 wt% and a liquid temperature of about 5 to 30 ° C. The conditions include immersion for about a second. The aluminum plate thus obtained is usually anodized, and particularly preferably, a method of treating with an electrolytic solution containing sulfuric acid can be mentioned. The method of anodic oxidation with an electrolytic solution containing sulfuric acid is a conventionally known method, for example, JP-A-58-2138.
It is carried out according to the method described in JP-A-94. Specifically, for example, sulfuric acid 5 to 50% by weight, preferably 15 to 30
% Is used, and the temperature is about 5 to 50 ° C., preferably 15
~ 35 ° C, current density 1 ~ 60A / dm ² for 5 seconds ~
It takes about 60 seconds. The amount of oxide film formed by this is 1 to 100 mg / dm ² , particularly 10 to 50 mg / dm ² .
It is preferably dm ² .

Further, if necessary, treatment with alkali silicate such as sodium silicate treatment or hot water, and other cationic 4
Surface treatment can be performed by immersion in an aqueous solution containing a resin having a primary ammonium group or an aqueous polymer compound such as polyvinylphosphonic acid or carboxymethyl cellulose. The photosensitive composition can be applied by a known method such as dip coating, coating rod, spinner coating, spray coating, or roll coating. The film thickness is not particularly limited, but is 0.1 to 1
0 g / m ^2, more preferably 0.5 to 5 g / m ^2.

In the present invention, it is desirable to provide an oxygen blocking layer on the above-mentioned photopolymerizable photosensitive layer in order to prevent the polymerization inhibition function of oxygen. (Oxygen barrier layer) Specific examples of the oxygen barrier layer include water-soluble polymers such as polyvinyl alcohol, polyvinylpyrrolidone, polyethylene oxide, and cellulose.
Among these, those containing polyvinyl alcohol having a particularly high oxygen gas barrier property are preferable.

Polyvinyl alcohol can be obtained by saponifying polyvinyl acetate with an alkali, an acid, aqueous ammonia or the like. The weight average molecular weight of polyvinyl alcohol in the present invention is preferably 20,000 to 500,000, more preferably 40,000 to 100,000. The saponification degree is preferably 70 mol% to 100 mol%, more preferably the saponification degree is 8.
Those of 0 mol% to 100 mol% are desirable. If the degree of saponification is less than the above range, the solubility in water or alkaline water tends to be poor and the removability tends to be poor. If the degree of saponification is more than the above range, the effect may not be sufficiently obtained. Specifically, for example, NK-05, KP-06, KP-08, K
L-05, KM-11, KH-17, KH-20, GL
-03, GL-05, GM-14, GH-17, GH-
20, GH-23, AL-06, AH-17, AH-2
6, NL-05, NM-11, NM-14, N-30
0, NH-20, NH-26 (all manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) and the like. Further, the weight average molecular weight, saponification degree is within the above range, water or alcohol such as methanol, ethanol, propanol, isononyl alcohol, polyvinyl alcohol soluble in a mixture of water-miscible organic solvent such as tetrahydrofuran and water. Derivatives can also be used. Examples of such derivatives include, for example, polyvinyl alcohol partially acetalized, modified polyvinyl alcohol cation-modified with a quaternary ammonium salt, and anion-modified with sodium sulfonate. Specific examples include T-330H, T-330ST, T-35.
0, T-230, T-215, K-210, Z-20
0, Z-200H, Z-210, Z-100, F-78
(All manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) and the like. The weight ratio of polyvinyl alcohol contained in the oxygen barrier layer is not particularly limited, but is preferably 10 wt% to 100 wt%, and preferably 20 wt% to 95 wt%.
% Is desirable.

In addition, various additives and methods such as a pyrrolidone compound, an acrylic emulsion, a diisocyanate compound, p-toluenesulfonic acid, and hydroxyacetic acid may be used to strengthen the adhesion between the photopolymerizable photosensitive layer and the oxygen barrier layer. . Among them, a compound containing vinylpyrrolidone as its constituent unit is particularly useful. Examples thereof include polyvinylpyrrolidone and vinylpyrrolidone / vinyl acetate copolymers. Examples thereof include polyvinylpyrrolidone and copolymers of vinylpyrrolidone and vinyl acetate. The weight ratio of the total amount of the vinylpyrrolidone unit structure in the oxygen barrier layer to the total oxygen barrier layer is not particularly limited, but is preferably 5 wt% to 70 wt%, preferably 10 wt% to 65 wt%, more preferably 15 wt%. % To 60 wt% is desirable. In addition, an organic acid such as succinic acid or an organic acid salt such as EDTA may be added to the oxygen barrier layer for improving storage stability.

In addition to the above, other substances can be added to and mixed with the oxygen barrier layer depending on the purpose of use.
Examples thereof include nonionic surfactants such as polyoxyethylene alkylphenyl ether, anionic surfactants such as sodium dodecylbenzene sulfonate, and other defoamers, dyes, plasticizers, pH adjusters and the like. The preferable content of the above-mentioned various additives is 1% in the oxygen barrier layer.
It is 0% by weight or less, more preferably 5% by weight or less.

The dry weight of the oxygen barrier layer of the present invention is not particularly limited, but is preferably 1 g / m ² or more and 10 g / m ² or less. It is more preferably 1.5 to 7 g / m ² . 1 g /
If it is less than m ² , the sensitivity of the photopolymerizable photosensitive material tends to be low, while if it exceeds 10 g / m 2, the developability tends to be poor. The oxygen blocking layer is applied by dissolving it in water or a mixed solvent of water and a water-miscible organic solvent, coating the solution on the photosensitive layer, and drying. As a coating method, a known method such as dip coating, coating rod, spinner coating, spray coating, roll coating, or die coating can be used.

After the oxygen barrier layer is provided, it is desirable that the oxygen barrier layer is stored in a packaging form that prevents excess moisture from invading from the outside before use. Specifically, examples include moisture-proof paper. In addition, a desiccant such as calcium chloride that removes moisture may be included inside the package. (Laser exposure) The laser exposure light source that can be applied to the image forming method of the present invention is not particularly limited, but, for example,
Violet laser oscillating 405 nm, Ar laser oscillating 488 nm, FD-YAG laser 532 nm, 830
Infrared semiconductor lasers having a wavelength of 10 nm, and YAG lasers that oscillate at 1016 nm are suitable examples.

(Developing Step) In the image forming method of the present invention, after imagewise exposure of the photosensitive lithographic printing plate with such a laser exposure machine, an aqueous solution containing a surfactant and an alkali agent and / or an organic solvent are used. An image can be formed on the support by developing with. The developing solution may further contain an organic solvent, a buffer, a dye or a pigment.
Suitable alkali agents include sodium silicate, potassium silicate, sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium triphosphate, dibasic sodium phosphate,
Inorganic alkaline agents such as sodium carbonate, potassium carbonate and sodium bicarbonate, and organic amine compounds such as trimethylamine, diethylamine, isopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamines, etc. Alternatively, they can be used in combination.

Examples of the surfactant include nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkylaryl ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, monoglyceride alkyl esters and the like;
The pH of the anionic surfactant image liquid such as alkylbenzene sulfonates, alkylnaphthalene sulfonates, alkyl sulfates, alkyl sulfonates, and sulfosuccinate salts is usually 9 to 14. Further, as the organic solvent, for example, isopropyl alcohol agent; amphoteric surfactants such as alkyl betaines and amino acids can be used. It is possible to contain alkali source, benzyl alcohol, ethyl cellosolve, butyl cellosolve, phenyl cellosolve, propylene glycol, diacetone alcohol, etc., if necessary.

The developing method is not particularly limited, but it may be a method of immersing and shaking in a developing solution, a method of physically removing a non-image portion which is about to be dissolved in the developing solution with a brush, or a method of spraying the developing solution. Examples include a method of spraying to remove the non-image area. The developing time may be appropriately selected from the range of 5 seconds to 10 minutes depending on the developing method as long as the unexposed portion can be sufficiently removed.

Incidentally, it is also possible to preferably carry out a heat treatment before the above-mentioned development treatment, or to remove the oxygen-shielding layer before development by a washing treatment etc. in the case of having an oxygen-shielding layer. In order to maintain the same developing performance for a long period of time, it is general to use a developing replenisher separately from the developing solution. Basically, the developer replenisher may contain an appropriate alkali agent or surfactant as in the case of the developer, if necessary, at a ratio lower than or equal to that of the developer, or at a higher ratio. The amount of the alkaline agent or the surfactant contained in the developer replenisher is not particularly limited, but it is generally within a range of 0.1 to 50 times the amount contained in the developer. is there. It is preferably 0.5 to 30 times.

Further, both the developing solution and the developing replenishing solution may be concentrated several times as much as in actual use for the purpose of simplifying transportation. The concentration ratio is usually 1.1 to 50 times, more preferably 2 to 30 times. (Drying Step) The present invention is characterized in that after the above developing treatment, the developing solution is washed away with water, the printing plate is dried, and then the gum solution is applied. That is, the feature is that the surface of the printing plate is dried before the gum solution coating step.

This point is different from the conventional method, that is, the step of applying the gum solution while the surface of the lithographic printing plate is wet after the washing with water after the developing treatment. According to the method of the present invention, the printing durability at the time of printing, especially the printing durability at the initial stage of printing is significantly improved. The method of drying treatment after washing with water is not particularly limited, for example, after squeezing water with a roller to some extent after washing with water, a method of completely blowing water from the plate surface by blowing air, or removing water from the plate surface using a heater or the like. Method, a method of removing water from the plate surface by blowing air with heat with a drier, a method of evaporating water while squeezing it with a heat roller, a method of washing and air-drying, or a combination of the above means. Particularly preferred is a method using a dryer, for example, 10
This is a method in which wind of about 20 to 100 ° C., preferably about 20 to 100 ° C., is applied to the plate surface for about 1 to 60 seconds to dry. Drying is preferably carried out to the extent that no water content is visually observed from the surface of the printing plate. For example, it suffices that moisture does not transfer to the surface of the paper even if the pulp paper is pressed against the surface of the press.

It is not clear why such a drying treatment increases the image strength and is advantageous for printing. However, in the conventional method, the gum solution is applied to the image which has been swollen in the developing treatment. It is conceivable that the gum solution penetrated into the image area and caused strong damage. The gum itself is peeled from the image surface at the initial stage of printing, but it is conceivable that the conventional method also peels the weakened image together with the gum at this time. On the other hand, if the gum solution is applied after the drying treatment, the swelling of the image area has already subsided, so that the rate of penetration of the gum solution into the image is greatly suppressed, and therefore peeling of the image especially at the initial stage of printing is performed. I think that will be suppressed.

After the drying treatment, it is preferable to apply the gum solution promptly, usually within 1 hour after the drying, preferably 3 hours.
It is recommended to apply the gum solution within 0 minutes. As gum solution, DIAMOND PLATE PLUS-FINI
SHER (Western Lithotec) and G
W-3 (manufactured by Mitsubishi Chemical Corporation) can be used. The drying step before coating the gum solution of the present invention is an essential condition after the development and washing with water and before the printing. Once printed, the image has already been damaged by the impact of printing, and the purpose of reducing the damage at the time of printing, which is the effect of the process of the present invention, particularly at the beginning of printing, is completely lost. I will end up. In this sense, the method and effect are completely different from the regumming liquid application for the purpose of reusing and protecting the photosensitive lithographic printing plate after printing.

(Post-Processing Related) In the present invention, the image intensity can be further enhanced by performing the whole surface exposure after the above-mentioned developing process. The light source for the entire surface post-exposure is not particularly limited, but examples thereof include carbon arc, high-pressure mercury lamp, ultra-high-pressure mercury lamp, low-pressure mercury lamp, Deep UV lamp,
Xenon lamp, metal halide lamp, fluorescent lamp,
Tungsten lamp, halogen lamp, excimer UV
Examples include lamps. The light emitted from these light sources may be used after being wavelength-limited by a filter or the like. Preferably, the light source for the post-exposure is a half width of 30 nm
It is desirable to have the following bright lines.

As specific examples of preferable light sources, excimer UV lamps, mercury lamps and metal halide lamps are preferable, and excimer UV lamps, high pressure mercury lamps and low pressure mercury lamps are particularly preferable. Although not particularly limited, it is preferable that the exposure intensity reaching the plate surface (exposure amount per unit time) at the time of whole surface exposure is 5 mW / cm ² or more. If the light intensity is lower than 5 mW / cm ² , the effect may be insufficient even if the total exposure amount is the same. The method of increasing the exposure intensity reaching the plate surface at the time of post-exposure to 5 mW / cm ² or more is not particularly limited, but one method is to increase the lamp output (W) of the exposure light source. For example, there is a method of simply increasing the lamp output, or a method of increasing the output per unit length (W / cm) in the case of a rod type lamp.

Another method is, for example, a method of simply bringing the exposure light source close to the image forming material. With this method, it is possible to easily increase the light intensity reaching the image forming material even when the lamp output of the exposure light source is relatively weak. Although not particularly limited, the preferred light intensity is 5 mW / cm ² ~
1 W / cm ² or less, more preferably 10 mW / cm ^{2 to} 5
It is 00 mW / cm ² .

Further, as a lighting method of various light sources, for example,
Normal continuous light lamp, flash irradiation type, instant lighting
Type etc. are mentioned. The post-exposure wavelength is 200
Light with a wavelength of ~ 1100 nm can be used. Post-exposure method
As a result, even if the image is stopped, the image is not processed.
It may be carried out in a state where it is continuously conveyed in the physical direction. Well
The exposure amount is not particularly limited and is large.
Although the effect can be expected, it is said that the rationalization of the image forming process
10mJ / cm from the meaning²Or more, preferably 50 mJ /
cm²Above, 10 J / cm ²Below, preferably 8 J / c
m²The following is desirable.

The temperature of the image-forming material during post-exposure is 40 ° C.
The heating or holding at 300 ° C. is particularly effective in improving the strength of the image unless other problems occur. The conditions and method are not particularly limited, and examples thereof include warm air such as a hot plate and a dryer, radiant heat such as a ceramic heater and a powerful light source. Particularly preferably, it is simple and preferable to use the radiant heat of the light source used for the post-exposure. If the temperature becomes too high, a problem such as deformation of the support may occur. Therefore, it is desirable to appropriately use a cooling device, a cold mirror or IR cut filter for reducing IR radiant heat so that the temperature falls within an appropriate temperature range.

In the present invention, the image strength can be further enhanced by carrying out a post-heating treatment on the entire surface after the development processing. The heating method is not particularly limited, and examples thereof include a method using radiant heat from an IR ceramic heater, a method using an oven, a method using a hot plate, and a method using a heating roller. Further, the use of radiant heat from the post-exposure light source mentioned above can also be mentioned similarly.

The post-heating may be carried out with the plate stopped or while the plate is continuously conveyed in the processing direction. The heating temperature is preferably 80 ° C to 30 at the plate surface.
It is preferably about 0 ° C, particularly preferably about 100 ° C to 250 ° C. The heating time is also not particularly limited, but it is 1 second to 15 seconds.
Minutes, particularly preferably about 1 second to 10 minutes.
Further, if necessary, in addition to the processing method described in the present invention, it is also effective to add a heating step immediately after laser exposure (before development) in order to improve the image strength in some cases. In this case as well, the conditions and method are not particularly limited, but examples of the image forming material include hot air from a hot plate or a dryer at 50 to 300 ° C., radiant heat from a ceramic heater or a powerful light source, and the like. When heating,
The image may be stopped or may be continuously conveyed in the processing direction.

[0112]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. <Creation of support> Aluminum plate (thickness 0.24 mm)
Was degreased with a 3% by weight aqueous solution of sodium hydroxide, and then 1
In a nitric acid bath of 8.0 g / liter, 25 ° C, 90 A / dm
Electrolytic etching was performed at a current density of ² for 11 seconds. Then, after desmutting with a 4.5 wt% sodium hydroxide aqueous solution at 30 ° C. for 2 seconds, it was neutralized with a 10 wt% nitric acid aqueous solution at 25 ° C. for 5 seconds, washed with water, and then washed in a 30 wt% sulfuric acid bath for 30 seconds.
The substrate was anodized at a current density of 10 A / dm ² for 16 seconds, washed with water and dried to obtain a support-1.

<Synthesis of Polymer Binder> A copolymer of methyl methacrylate / methacrylic acid = 80/20 mol% (preparation ratio), Mw = 50,000 (hereinafter abbreviated as “binder-1”) was used. 9 parts by weight, 7.28 parts by weight of the following alicyclic epoxy-containing unsaturated compound,

[0114]

[Chemical 17]

0.044 parts by weight of p-methoxyphenol, 0.17 parts by weight of tetrabutylammonium chloride and 87.4 parts by weight of propylene glycol monomethyl ether acetate were added to the reaction vessel, and the mixture was heated at 110 ° C. for 24 hours.
The reaction is carried out by stirring in the air for a period of time, and the ethylenic polymer binder (acid value 53, 5% of the total methacrylic acid component of binder-1
The unsaturated group reacts. Hereafter, it is abbreviated as "bonding material-2". ) A solution was obtained.

<Examples 1 to 3 and Comparative Example 1> On the above support-1, the following photopolymerizable composition coating liquid-1 was added to propylene glycol monomethyl ether acetate and cyclohexanone (5: 5 by weight ratio). Dissolve so that the solid content becomes 12 wt% and dry film thickness 2 g /
It was applied and dried so as to be m ² . Furthermore, polyvinyl alcohol (trade name GL-03, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) and polyvinyl pyrrolidone (trade name K-30, BAS) are further provided on the above.
A mixed aqueous solution (manufactured by Company F) (polyvinyl alcohol: polyvinylpyrrolidone = 70% by weight: 30% by weight) was applied using a bar coater so that the dry film thickness was 3 g / m ^2, and dried at 70 ° C. for 4 minutes. Photosensitive planographic printing plate-1 was prepared by forming an oxygen barrier layer.

(Photopolymerizable composition coating liquid-1) Radical generator R-1 15 parts by weight Sensitizer S-1 9 parts by weight 2-mercaptobenzothiazole 5 parts by weight N-phenylglycine benzyl ester 3 parts by weight Ethylene 22 parts by weight of ethylenic monomer E-2 22 parts by weight of ethylenic monomer E-2 6 parts by weight of ethylenic monomer E-3 11 parts by weight of ethylenic monomer E-4 11 parts by weight of polymer binder P-1 45 parts by weight Tribenzylamine 9 parts by weight Phthalocyanine pigment 4 parts by weight Disperbyk 161 (Dispersant by Big Chemie) 2 parts by weight Emulgen 104P (manufactured by Kao) 2 parts by weight S-381 (fluorine-based surfactant) 0.3 parts by weight Among the components of the photopolymerizable composition, the structure of each compound of the radical generator, the sensitizer, the ethylene monomer and the polymer binder is as follows.

[0118]

[Chemical 18]

[0119]

[Chemical 19]

[0120]

[Chemical 20]

[0121]

[Chemical 21]

The photosensitive lithographic printing plate-1 thus obtained was evaluated as follows. <Measurement of image forming method and printing performance> Under the conditions shown in Table 1 below, exposure with a Violet laser irradiation device (trade name: Cobalt 8; manufactured by Escher-Grad) oscillating 405 nm (exposure amount: 35 μJ / cm ² ) Was done. After that, an image was formed with an automatic processor equipped with a Pre water washing unit (trade name: Interplater; manufactured by Glunz & Jansen) under the operations and conditions shown in Table 1 below. In addition, the developer in the developing machine is A potassium silicate 3
% By weight, Perex NBL (manufactured by Kao Corporation) 5% by weight
It was an aqueous solution containing K (solution K). The density (%) on the paper surface at the time of printing was measured by ccDOT (manufactured by Centurafax). The gum solution is Diamond Plate
PLUS-FINISHER (Western Lit
Hotec) 1.5 times diluted aqueous solution was used.

[0123]

[Table 1]

<Examples 4 to 6 and Comparative Examples 2 and 3> On the above-mentioned support-1, the following photopolymerizable composition coating liquid-2 was added to propylene glycol monomethyl ether acetate and cyclohexanone (5: 5 by weight ratio). ) Has a solid content of 12 wt%
Dissolve so as to obtain a dry film thickness of 2 using a bar coater.
It was applied and dried so as to be g / m ² . Furthermore, polyvinyl alcohol (trade name GL-03; manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) and polyvinyl pyrrolidone (trade name K-30. BA
SF (manufactured by SF) (polyvinyl alcohol: polyvinylpyrrolidone = 70% by weight: 30% by weight) was applied using a bar coater to a dry film thickness of 3 g / m ^2, and dried at 70 ° C for 4 minutes. A photosensitive lithographic printing plate-2 was prepared by forming an oxygen barrier layer.

(Photopolymerizable composition coating liquid-2) Radical generator R-2 5 parts by weight 2-mercaptobenzothiazole 5 parts by weight N-phenylglycine benzyl ester 5 parts by weight Sensitizer S-21 1 part by weight below Parts the above ethylenic monomer E-1 22 parts by weight the above ethylenic monomer E-2 22 parts by weight the above ethylenic monomer E-3 8 parts by weight the above polymer binder P-1 45 parts by weight pigment ( P.B.15: 6) 4 parts by weight Emulgen 104P (manufactured by Kao Corporation) 2 parts by weight S-381 (manufactured by Asahi Glass Co., Ltd. fluorine-based surfactant) 0.3 parts by weight Disperbyk 161 (manufactured by BYK Chemie) Dispersant) 2 parts by weight The structures of the radical generator R-2 and the sensitizer S-2 in the photopolymerizable composition are as follows.

The photosensitive lithographic printing plate-2 thus obtained was evaluated as follows.

[0127]

[Chemical formula 22]

[0128]

[Chemical formula 23]

<Measurement of Image Forming Method and Printing Performance> Under the conditions shown in Table 2 below, exposure with an FD-YAG laser irradiation device (trade name: PlateJet; manufactured by CYMBOLIC SCIENCE) oscillating 532 nm (exposure amount: 150 μJ) / cm ² ) was performed. Then Pre
Automatic processor with a washing unit (trade name: Interplate
r; manufactured by Glunz & Jansen), and image formation was performed under the operations and conditions described in Table 2 below. The developer in the developing machine was an aqueous solution (K solution) containing 3% by weight of potassium A silicate and 5% by weight of Perex NBL (manufactured by Kao Corporation). Then, the planographic printing plate was put on a DAIYA-1F-2 type printing machine (manufactured by Mitsubishi Heavy Industries, Ltd.) to perform a printing durability test. As for printing durability, the remaining condition of 175 lines and 1% points at the time of 50,000 sheets was evaluated.

The case where the small dots remained without being chipped was evaluated as ◯, the state where most of the particles were partially skipped was evaluated as Δ, and the state where the small dots were hardly left was evaluated as x. The results are shown in Table-2.

[0131]

[Table 2]

[0132]

EFFECTS OF THE INVENTION According to the present invention, in a series of steps of developing, rinsing and coating gum solution on a lithographic printing plate, a simple treatment of drying is performed between the rinsing step and the gum solution coating step to obtain an image. The strength is remarkably improved, and it is possible to form an image having excellent printing durability particularly in the initial stage of printing.

Continued front page    (72) Inventor Toshiaki Katayama             1000 Kamoshida-cho, Aoba-ku, Yokohama-shi, Kanagawa             Mitsubishi Chemical Corporation Yokohama Research Institute (72) Inventor Eriko Toshimitsu             1000 Kamoshida-cho, Aoba-ku, Yokohama-shi, Kanagawa             Mitsubishi Chemical Corporation Yokohama Research Institute F-term (reference) 2H096 AA07 AA08 BA05 BA20 EA04                       GA08 GA17 GA20 HA02 JA04                       LA16

Claims (5)

[Claims] 1. A photosensitive lithographic printing plate provided with a photopolymerizable photosensitive layer containing an ethylenic monomer, a photopolymerization initiator and a polymer binder on a support is subjected to a laser exposure, a development step and a water washing. Step, in the plate method of the photosensitive lithographic printing plate which sequentially performs the gum solution coating step, a photosensitive lithographic printing plate characterized by performing a drying treatment of the printing plate between the water washing step and the gum solution coating step Plate printing method. 2. The method of printing a photosensitive lithographic printing plate according to claim 1, wherein the developing step, the water washing step, the drying step and the gum solution coating step are carried out in a continuous series of steps. 3. The drying treatment is carried out by applying warm air to the surface of the printing plate with a drier so that the surface temperature of the printing plate is 25 to 100 ° C.
The method for printing a photosensitive lithographic printing plate according to claim 1 or 2, wherein the temperature is maintained for 1 to 60 seconds. 4. The printing plate method for a photosensitive lithographic printing plate according to claim 1, wherein the gum solution is applied within 30 minutes after the drying treatment. 5. The printing plate method for a photosensitive lithographic printing plate as claimed in claim 1, wherein the photopolymerization initiator comprises a sensitizing dye and a radical generator.