JP2000112132A - Photopolymerizable planographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photopolymerizable planographic printing plate having excellent printing durability and little stain in a nonpicture area. SOLUTION: This printing plate has an intermediate layer on a substrate which is prepared by forming an anodically oxidized film on an aluminum of aluminum alloy substrate and then subjecting to silicate treatment. The intermediate layer has a polymer compd. produced by using a structural component having acid groups and a structural component having onium groups. Moreover, the printing plate has a photopolymerizable photosensitive layer on the intermediate layer. The photosensitive layer contains compds. having at least one ethylenic unsatd. bond which are polymerizable with active rays, linear org. polymers and a photopolymn. initiator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a photopolymerizable lithographic printing plate. More specifically, argon laser (488, 514.5 nm), second harmonic of semiconductor laser (SHG-LD, 350 to 600 nm), SHG-YA
The present invention relates to a negative type lithographic printing plate which can be directly made by using a G laser (532 nm) without using a film original.

[0002]

2. Description of the Related Art Negative type lithographic printing plates have been widely known and have various photosensitive layers. There are diazo resin-containing types, photopolymerization types, photocrosslinking types, and the like. In order to prepare such a lithographic printing plate, it is common to place a transparent negative film original on the lithographic printing plate and to perform image exposure using ultraviolet rays, which requires a lot of work.

[0003] Therefore, by using a kind of high-sensitivity photopolymerization layer in the photosensitive layer, a laser beam with a narrow beam is scanned on the plate surface, and a character document, an image document, and the like are formed directly on the plate surface. Plate making can be performed directly without using a film original.

However, conventionally, such a highly sensitive photopolymerizable lithographic printing plate depends on the conditions when used as a printing plate, but it is difficult to obtain sufficient adhesion between the photopolymerizable photosensitive layer and the hydrophilic support. In addition, when printing a large number of copies, images are missing and printing durability is likely to be insufficient.

As a technique for improving the adhesion between a hydrophilic support and a photopolymerizable photosensitive layer, for example, JP-A-4-161957 discloses that a silane coupling agent having a specific structure is contained in a photosensitive layer. However, in this method, when the photosensitive lithographic printing material is stored for a long period of time, the solubility of the developing solution in the non-image area is reduced due to the reaction of the silane coupling agent during storage, and the non-image area is significantly stained during printing. JP 7
No. 159983 discloses a technique in which a layer containing a silicone compound having a functional group capable of radical addition polymerization is provided on a hydrophilic support, and a photopolymerizable photosensitive layer is further provided thereon. Adhesion between the photosensitive layer and the hydrophilic support by the silicone compound layer forms a covalent bond between the silicone compound having a functional group capable of radical addition polymerization by a radical polymerization reaction generated in the photosensitive layer by image exposure. It is believed that the photosensitive layer is strongly adhered to the hydrophilic support. On the other hand, since such a radical reaction does not occur in the non-image portion, the adhesive force does not increase. However, since the radical-reactive group as described above is an organic group, if a large amount of the silicone compound having a functional group remains on the hydrophilic surface of the non-image area, the ink receptivity increases, and printing stains on the non-image area are reduced. Occurs.

Therefore, the adhesive force between the hydrophilic support and the silicone compound having a radical reactive group cannot be increased so much.

Further, in such a lithographic printing plate, when a stain occurs during printing, the plate surface is wiped with a plate cleaner on a printing press to remove the ink, but the adhesive force between the surface of the hydrophilic support and the silicone compound is removed. Is not so large, and there has been a problem that, by wiping with a plate cleaner, images of small dots and fine lines of highlights gradually fly.

[0008]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for highlighting even if a plate cleaner is used to remove ink on a plate surface or a large amount of printing is performed due to the strong adhesion between a photosensitive layer and a support. It does not fly, has excellent shadow reproducibility, is capable of laser writing with printing durability, and is hard to change the adhesion between the support and the photosensitive layer even after storage over time, and photopolymerization that does not cause printing stains To provide a lithographic printing plate.

[0009]

Means for Solving the Problems As a result of earnest studies, the present inventors have solved the above-mentioned object by the following photopolymerizable lithographic printing plate. (1) After providing anodized film, silicate (silicate)
An intermediate layer containing a polymer compound obtained using a component having an acid group and a component having an onium group on a substrate formed of treated aluminum or an aluminum alloy; A photopolymerizable lithographic plate having a photopolymerizable photosensitive layer containing at least one compound having at least one ethylenically unsaturated bond polymerizable by actinic light, a linear organic polymer, and a photopolymerization initiator. Print version.

Conventionally, when a photosensitive layer was provided on an aluminum support which had been subjected to a hydrophilization treatment by silicate treatment or the like, the adhesion was low and the printing durability was remarkably low. By providing an intermediate layer containing a polymer compound obtained by polymerizing the component and a component having an onium group, the adhesion was improved, and the printing durability was remarkably improved. In addition, such adhesion does not easily deteriorate with time, and printing stains are less likely to occur.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail. The photopolymerizable lithographic printing plate of the present invention has an intermediate layer provided between a support such as aluminum which has been subjected to a predetermined hydrophilic treatment and a photopolymerizable photosensitive layer. [(A) Intermediate Layer] The polymer compound used for forming the intermediate layer of the present invention will be described in detail. The polymer compound of the present invention is a polymer compound obtained by polymerizing a component having at least an acid group and a component having at least an onium group. Here, a preferable acid group is an acid group having an acid dissociation constant (pKa) of 7 or less,
More preferably _{-COOH, -SO 3 H, -OSO 3} H,
_{-PO 3 H 2, -OPO 3 H} 2, -CONHSO 2 -, - S
O ₂ NHSO ₂ —, particularly preferably —COOH. Preferred as the onium group is an onium group composed of an atom of Group 5B (Group 15) or Group 6B (Group 16) of the Periodic Table, more preferably an onium group composed of a nitrogen atom, a phosphorus atom or a sulfur atom. And
Particularly preferred is an onium group consisting of a nitrogen atom.

Among the polymer compounds of the present invention, preferably, the main chain structure of the polymer compound is a vinyl-based polymer such as an acrylic resin, a methacrylic resin, or polystyrene, a urethane resin, a polyester, or a polyamide. It is a characteristic polymer.

More preferably, the polymer is characterized in that the main chain structure of the polymer compound is a vinyl polymer such as an acrylic resin, a methacrylic resin, or polystyrene.

Particularly preferably, the component having an acid group is a polymerizable compound represented by the following formula (1) or (2), and the component having an onium group is a compound represented by the following formula (3): A polymer represented by Formula (4) or Formula (5).

[0016]

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In the formula, A represents a divalent linking group. B represents a divalent aromatic group or a substituted aromatic group. D and E each independently represent a divalent linking group. G represents a trivalent linking group. X and X 'each independently have a pKa of 7
The following acid groups or their alkali metal salts or ammonium salts are represented. R ₁ represents a hydrogen atom, an alkyl group or a halogen atom. a, b, d, and e each independently represent 0 or 1. t is an integer of 1 to 3.

More preferably, A represents -COO- or -CONH-, B represents a phenylene group or a substituted phenylene group, and the substituent is a hydroxyl group, a halogen atom or an alkyl group. It is.
Alkylene group or a molecular formula D and E are each independently represents C _n H _2n O, 2 divalent linking group represented by C _n H _2n S or C _n H _{2n + 1} N. G has a molecular formula of C _n H _2n-1 ,
C _n H _2n-1 O, represents a trivalent linking group represented by C _n H _{2n- 1} S or C _n H _2n N. Here, n represents an integer of 1 to 12. X and X 'each independently represent a carboxylic acid, a sulfonic acid, a phosphonic acid, a sulfuric acid monoester or a phosphoric acid monoester. R ₁ represents a hydrogen atom or an alkyl group. a, b, d, and e each independently represent 0 or 1, but a and b are not 0 at the same time.

Among the components having an acid group, a compound represented by the formula (1) is particularly preferred, wherein B represents a phenylene group or a substituted phenylene group, and the substituent is a hydroxyl group or an alkyl group having 1 to 3 carbon atoms. It is. D and E each independently represent an alkylene group having 1 to 2 carbon atoms or an alkylene group having 1 to 2 carbon atoms linked by an oxygen atom.
R ₁ represents a hydrogen atom or a methyl group. X represents a carboxylic acid group. a is 0 and b is 1.

Specific examples of the component having an acid group are shown below. However, the present invention is not limited to this specific example.

(Specific examples of components having an acid group) Acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, itaconic acid, maleic acid, maleic anhydride

[0022]

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[0023]

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[0024]

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Next, the polymerizable compounds represented by the formulas (3), (4) and (5) used as the constituent having an onium group will be described.

[0026]

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In the formula, J represents a divalent linking group. K represents an aromatic group or a substituted aromatic group. M each independently represents a divalent linking group. Y ₁ is group 5B of the periodic table (15
And Y ₂ represents Group 6B (Group 16) of the periodic table.
Represents a group of atoms. And Z ^- represents a counter anion. R ₂ represents a hydrogen atom, an alkyl group or a halogen atom. R ₃ , R ₄ ,
R ₅ and R ₇ are each independently a hydrogen atom or an alkyl group to which a substituent may be bonded, an aromatic group,
It represents an aralkyl group, and R ₆ represents an alkylidine group or a substituted alkylidine, and R ₃ and R ₄ or R ₆ and R ₇ may be bonded to each other to form a ring. j, k, and m each independently represent 0 or 1. u represents an integer of 1 to 3.

More preferably, among the components having an onium group, J represents -COO- or -CONH-,
K represents a phenylene group or a substituted phenylene group, and the substituent is a hydroxyl group, a halogen atom or an alkyl group. M is an alkylene group or a molecular formula C _n H _2n O,
It represents a divalent linking group represented by C _n H _2n S or C _n H2 _{n + 1} N. Here, n represents an integer of 1 to 12. Y
₁ represents a nitrogen atom or a phosphorus atom, and Y ₂ represents a sulfur atom. Z ^- is a halogen ion, PF ₆ ^-, BF ₄ ^- or R ₈ SO ₃ ^- (wherein R ₈ is an alkyl group, an aryl group.) Represents a R ₂ represents a hydrogen atom or an alkyl group. R ₃ , R
_4, R _5, R ₇ are each independently hydrogen atom or an alkyl group having 1 to 10 carbon atoms which may be bonded substituent optionally, an aromatic group, an aralkyl group, R ₆ is C 1 -C Represents an alkylidine group of 10 to 10 or a substituted alkylidine, and R ₃ and R ₄ or R ₆ and R ₇ may be bonded to each other to form a ring. j, k, and m each independently represent 0 or 1, but j and k are not 0 at the same time. Particularly preferably, among the constituent components having an onium group, K represents a phenylene group or a substituted phenylene group, and the substituent is a hydroxyl group or an alkyl group having 1 to 3 carbon atoms.
M represents an alkylene group having 1 to 2 carbon atoms or an alkylene group having 1 to 2 carbon atoms linked by an oxygen atom. Z ^- is a chloride ion or R ₈ SO ₃ ^- represents a. R ₂ represents a hydrogen atom or a methyl group. j is 0 and k is 1.

Specific examples of the constituent having an onium group are shown below. However, the present invention is not limited to this specific example.

[0030]

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[0031]

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The polymer compound used here contains a component having an acid group in an amount of 20 mol% or more, preferably 40 mol% or more.
At least 10 mol% and not more than 80 mol%, preferably at least 15 mol% and not less than 7 mol%.
It is desirable to contain 0 mol% or less. When the component having an acid group is contained in an amount of 20 mol% or more, dissolution and removal during alkali development are further promoted, and the component having an onium group is contained in an amount of 1%.
When it is contained in an amount of 0 mol% or more, the adhesion is further improved due to a synergistic effect with an acid group.

The components having an acid group may be used alone or in combination of two or more. The components having an onium group may be used alone or in combination of two or more. Further, the polymer compound according to the present invention is a polymer compound having different components or composition ratios or different molecular weights.
You may mix and use more than one type.

Next, typical examples of the polymer compound used in the present invention are shown below. The composition ratio of the polymer structure represents a mole percentage.

[0035]

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[0036]

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[0037]

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[0038]

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The polymer compound according to the present invention generally comprises
It can be manufactured using a radical chain polymerization method ("T
extbook of Polymer Science "3rd ed., (1984) FWBill
meyer, A Wiley-Interscience Publication).

The molecular weight of the polymer compound according to the present invention may be in a wide range, but the weight average molecular weight (Mw) is preferably from 500 to 2,000,000, more preferably from 2,000 to 2,000 as measured by a light scattering method. More preferably, it is in the range of 600,000. Further, the amount of unreacted monomer contained in the polymer compound may be wide, but is preferably 20 wt% or less, and more preferably 10 wt% or less.

Next, a synthesis example of the polymer compound according to the present invention will be described. [Synthesis Example] Synthesis of copolymer (No. 1) of p-vinylbenzoic acid and vinylbenzyltrimethylammonium chloride p-vinylbenzoic acid [manufactured by Hokuko Chemical Industry Co., Ltd.] 146.
9 g (0.99 mol), 44.2 g (0.21 mol) of vinylbenzyltrimethylammonium chloride and 2
446 g of methoxyethanol in 1 L (liter) of 3
Heat in a flask with stirring while stirring under a nitrogen stream.
It was kept at 5 ° C. Next, 2.76 g (12 mmol) of dimethyl 2,2-azobis (isobutyrate) was added, and stirring was continued. 2
After an hour, 2,2-azobis (isobutyric acid) dimethyl 2.7
An additional 6 g (12 mmol) was added. After another two hours,
2.76 g of dimethyl azobis (isobutyrate) (12 mmo
l) added. After stirring for 2 hours, the mixture was allowed to cool to room temperature. This reaction solution was poured into 12 L of ethyl acetate with stirring. The precipitated solid was collected by filtration and dried. The yield is 18
It was 9.5 g. As a result of measuring the molecular weight of the obtained solid by a light scattering method, the weight average molecular weight (Mw) was 32,000.

Other polymer compounds according to the present invention are synthesized in a similar manner.

The intermediate layer of the polymer compound according to the present invention is provided by applying various methods on an aluminum plate which has been subjected to a hydrophilic treatment described later.

This layer can be provided by the following method.

A solution obtained by dissolving the polymer compound of the present invention in an organic solvent such as methanol, ethanol, methyl ethyl ketone, or a mixed solvent thereof, or a mixed solvent of these organic solvents and water is coated on an aluminum plate and dried. The method of providing, and immersing the aluminum plate in a solution obtained by dissolving the polymer compound of the present invention in an organic solvent such as methanol, ethanol, methyl ethyl ketone, or a mixed solvent of these organic solvents and water, or a mixed solvent thereof, polymer In this method, the compound is adsorbed, then washed with water or the like, and dried to provide an organic intermediate layer. In the former method, 0.005 to 10% by weight of the polymer compound is used.
Can be applied in various ways. For example, any method such as bar coater coating, spin coating, spray coating, and curtain coating may be used. In the latter method, the concentration of the solution is 0.01 to 20% by weight, preferably 0.05 to 5% by weight, and the immersion temperature is 20 to 90 ° C.
Preferably, the temperature is 25 to 50 ° C., and the immersion time is 0.1 second to
20 minutes, preferably 2 seconds to 1 minute.

The above solution may be a basic substance such as ammonia, triethylamine or potassium hydroxide; an inorganic acid such as hydrochloric acid, phosphoric acid, sulfuric acid or nitric acid; an organic sulfonic acid such as nitrobenzenesulfonic acid or naphthalenesulfonic acid; PH by various organic acidic substances such as organic phosphonic acids such as acids, benzoic acid, coumaric acid, and organic carboxylic acids such as malic acid; and organic chlorides such as naphthalene sulfonyl chloride and benzenesulfonyl chloride.
PH = 0 to 12, more preferably pH = 0 to
5 can be used. Further, a yellow dye can be added for improving the tone reproducibility of the photopolymerizable lithographic printing plate.

[0047] The coating amount after drying of the polymer compound of the present invention is shown in the lithographic printing plate 1 m ² per is suitably 2 to 100 mg / m ^2, preferably from 5 to 50 mg / m ^2. If the coating amount is small, a sufficient effect cannot be obtained. The same is true for most cases.

[(B) Photopolymerizable Photosensitive Layer] The main components of the photopolymerizable photosensitive layer used in the present invention are a compound containing an addition-polymerizable ethylenic double bond, a photopolymerization initiator, and an organic polymer. Various compounds such as a coloring agent, a plasticizer, and a thermal polymerization inhibitor are added as needed.

The compound containing an addition-polymerizable double bond is
The compound can be arbitrarily selected from compounds having at least one, preferably two or more terminal ethylenically unsaturated bonds.

For example, it has a chemical form such as a monomer, a prepolymer, ie, a dimer, a trimer and an oligomer, or a mixture thereof and a copolymer thereof.

Examples of monomers and copolymers thereof include esters of unsaturated carboxylic acids (eg, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.) and aliphatic polyhydric alcohol compounds. And amides of unsaturated carboxylic acids and aliphatic polyamine compounds.

Specific examples of the ester monomer of the aliphatic polyhydric alcohol compound and the unsaturated carboxylic acid include acrylic acid esters such as ethylene glycol diacrylate, triethylene glycol diacrylate, and 1,3.
-Butanediol diacrylate, tetramethylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate Reto, 1,4-cyclohexanediol diacrylate, tetraethylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetra Acrylate, sol Penta acrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, polyester acrylate oligomer.

Examples of the methacrylate include tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, and 1,3-butanediol. Dimethacrylate, hexanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol dimethacrylate, dipentaerythritol hexamethacrylate, sorbitol trimethacrylate, sorbitol tetramethacrylate, bis [p- (3- Methacryloxy-2-hi Rokishipuropokishi) phenyl] dimethyl methane, bis - [p- (methacryloxyethoxy) phenyl] dimethyl methane.

Examples of itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate,
There are 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate, sorbitol tetritaconate and the like.

As the crotonic acid ester, ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate,
Sorbitol tetradicrotonate and the like.

Examples of the isocrotonic acid ester include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate.

Examples of the maleic acid ester include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate.

Further, a mixture of the above-mentioned ester monomers can also be mentioned.

Specific examples of the amide monomer of the aliphatic polyamine compound and the unsaturated carboxylic acid include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6- Hexamethylene bis-methacrylamide,
Examples include diethylenetriaminetrisacrylamide, xylylenebisacrylamide, xylylenebismethacrylamide, and the like.

As another example, see JP-B-48-417.
08 polyisocyanate compound having two or more isocyanate groups in one molecule described in
A vinyl urethane compound containing two or more polymerizable vinyl groups in one molecule to which a hydroxyl group-containing vinyl monomer represented by the following formula (6) is added is exemplified.

CH ₂ ＣC (R ¹² ) COOCH ₂ CH (R ¹³ ) OH (6) (where R ¹² and R ¹³ represent H or CH ₃ )

Further, urethane acrylates described in JP-A-51-37193,
64183, JP-B-49-43191, JP-B-52
And polyfunctional acrylates and methacrylates such as polyester acrylates and epoxy acrylates obtained by reacting an epoxy resin with (meth) acrylic acid as described in JP-A-30490. Furthermore, the Japan Adhesion Association magazine vol.20, No.7, 300-308 pages (19
(1984) as photocurable monomers and oligomers can also be used. In addition, the use amount of these is 5 to 70% by weight (hereinafter abbreviated as%), preferably 10 to 50% with respect to all components.

Examples of the photopolymerization initiator include various photoinitiators known in patents and literatures depending on the wavelength of the light source used.
Alternatively, a combination system (photoinitiating system) of two or more photoinitiators can be appropriately selected and used.

For example, when light near 400 nm is used as a light source, benzyl, benzoin ether, Michler's ketone, anthraquinone, thioxanthone, acridine,
Phenazine, benzophenone and the like are widely used.

Various light-initiating systems have also been proposed when using visible light of 400 nm or more, an Ar laser, the second harmonic of a semiconductor laser, or an SHG-YAG laser as a light source. No. 2,850,445, certain photosensitive dyes, a complex initiation system of a dye and an amine (Japanese Patent Publication No. 44-20189), and a combination system of hexaarylbiimidazole, a radical generator and a dye (Japanese Patent Publication No. 45-189).
37377), hexaarylbiimidazole and p-
Dialkylaminobenzylidene ketone system
No. 2528, JP-A-54-155292), and a system of a cyclic cis-α-dicarbonyl compound and a dye (JP-A-48-155292).
84183), a system of a cyclic triazine and a merocyanine dye (Japanese Patent Application Laid-Open No. 54-151024), a system of a 3-ketocoumarin and an activator (Japanese Patent Application Laid-Open Nos. 52-112681 and 5).
8-155503), a system of biimidazole, a styrene derivative, and a thiol (JP-A-59-140203), and a system of an organic peroxide and a dye (JP-A-59-140203).
JP-A-59-189340), a system of a dye having a rhodanine skeleton and a radical generator (JP-A-2-244050),
System of titanocene and 3-ketocoumarin dyes
No. 221110), a system comprising a combination of titanocene and a xanthene dye, and an addition-polymerizable ethylenically unsaturated compound containing an amino group or a urethane group (Japanese Patent Laid-Open No. 4-2).
21958, JP-A-4-219756), a system of titanocene and a specific merocyanine dye (JP-A-6-2950)
No. 61) and the like.

These photopolymerization initiators are used in an amount of 0.05 to 10 based on 100 parts by weight of the ethylenically unsaturated compound.
0 parts by weight, preferably 0.1 to 70 parts by weight, and more preferably 0.2 to 50 parts by weight.

The photopolymerizable composition usually contains a linear organic high molecular polymer as a binder. Such an organic high molecular compound has compatibility with a photopolymerizable ethylenically unsaturated compound. Any organic polymer may be used as long as it has the organic polymer. Preferably, water or weakly alkaline water-soluble or swellable organic high molecular polymers that enable water development or weakly alkaline water development are selected. The organic high-molecular polymer is selected and used not only as a film-forming agent of the photopolymerizable composition but also as a water, weakly alkaline water or organic solvent developer. For example, when a water-soluble organic high molecular polymer is used, water development becomes possible. Examples of such an organic high molecular polymer include an addition polymer having a carboxylic acid group in a side chain, for example, Japanese Patent Application Laid-Open No.
-44615, JP-B-54-34327, JP-B-5
Nos. 8-12577, JP-B-54-25957, JP-A-54-92723, JP-A-59-53836, and JP-A-59-71048, that is, methacrylic acid copolymers, There are acrylic acid copolymer, itaconic acid copolymer, crotonic acid copolymer, maleic acid copolymer, partially esterified maleic acid copolymer and the like.

Similarly, there is an acidic cellulose derivative having a carboxylic acid group in the side chain. In addition, those obtained by adding a cyclic acid anhydride to an addition polymer having a hydroxyl group are useful. Particularly, among these, [benzyl (meth) acrylate / (meth) acrylic acid / optionally other addition-polymerizable vinyl monomers] copolymer and [allyl (meth)
Acrylate (meth) acrylic acid / optionally other addition-polymerizable vinyl monomers] copolymer is preferred.
In addition, polyvinyl pyrrolidone and polyethylene oxide are useful as the water-soluble organic polymer. In order to increase the strength of the cured film, an alcohol-soluble polyamide, a polyether of 2,2-bis- (4-hydroxyphenyl) -propane and epichlorohydrin, and the like are also useful. These organic high-molecular polymers can be mixed in an arbitrary amount in the entire composition. However, if it exceeds 90% by weight, no favorable result is obtained in view of the strength of the formed image and the like. Preferably it is 30 to 85% by weight. Further, the weight ratio of the photopolymerizable ethylenically unsaturated compound and the organic polymer is preferably in the range of 1/9 to 9/1. A more preferred range is 2/8 to 8/2, and still more preferably 3/7 to 7/3.

In the present invention, in addition to the above basic components, a small amount of thermal polymerization is inhibited in order to prevent unnecessary thermal polymerization of a polymerizable ethylenically unsaturated compound during the production or storage of the photosensitive composition. It is desirable to add an agent. Suitable thermal polymerization inhibitors include haloid quinone, p-
Methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis (3-methyl-6-t-butylphenol), 2,2'-methylenebis (4-methyl −
6-t-butylphenol), N-nitrosophenylhydroxyamine primary cerium salt and the like. The addition amount of the thermal polymerization inhibitor is about 0.01 to the weight of the whole composition.
% To about 5% is preferred. Further, if necessary, a higher fatty acid derivative such as behenic acid or behenic acid amide may be added to prevent polymerization inhibition by oxygen, and may be unevenly distributed on the surface of the photosensitive layer in a drying process after coating. . The addition amount of the higher fatty acid derivative is preferably about 0.5% by weight to about 10% by weight of the whole composition.

Further, a coloring agent may be added for the purpose of coloring the photosensitive layer. Examples of the coloring agent include phthalocyanine pigments, azo pigments, pigments such as carbon black and titanium oxide, ethyl violet, crystal violet, azo dyes, anthraquinone dyes, and cyanine dyes. The amount of the dye or pigment added is preferably about 0.5% to about 5% by weight of the total composition.

In addition, additives such as an inorganic filler and a plasticizer such as dioctyl phthalate, dimethyl phthalate and tricresyl phosphate may be added to improve the physical properties of the cured film.

The amount of these additives is preferably 10% by weight or less of the total composition.

When the photopolymerizable composition of the present invention is coated on a support (on the intermediate layer in the present invention), it is used after being dissolved in various organic solvents (solvents). As the solvent used here, acetone, methyl ethyl ketone, cyclohexane, ethyl acetate, ethylene dichloride, tetrahydrofuran, toluene, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, Acetylacetone, cyclohexanone,
Diacetone alcohol, ethylene glycol monomethyl ether acetate, ethylene glycol ethyl ether acetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether acetate, 3-methoxypropanol, methoxymethoxyethanol, diethylene glycol monomethyl ether,
Diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, 3-methoxypropyl acetate,
N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, methyl lactate, ethyl lactate and the like. These solvents can be used alone or as a mixture. The appropriate concentration of the solid content in the coating solution is 1 to 50% by weight.

A surfactant can be added to the photopolymerizable composition of the present invention in order to improve the quality of the coated surface.

The coating amount is about 0.1 g / m ^{2 by} weight after drying.
Range of about 10 g / m ² are suitable. More preferably, 0.
It is 3 to 5 g / m ² . More preferably, it is 0.7 to 3 g / m ² .

[(C) Support] The support used in the photopolymerizable lithographic printing plate of the present invention and the treatment thereof will be described below.

(Aluminum Plate) The aluminum plate used in the present invention is a plate-like body of pure aluminum or an aluminum alloy containing aluminum as a main component and containing a trace amount of foreign atoms. The hetero atoms include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, titanium and the like. 10% by weight as alloy composition
It has the following heteroatom content. Aluminum that is suitable for the present invention is pure aluminum, but it is preferable that completely pure aluminum contains as little foreign atoms as possible because it is difficult to produce due to refining technology. Further, any aluminum alloy having a different atomic content of the above-described level can be said to be a material that can be used in the present invention. As described above, the composition of the aluminum plate used in the present invention is not particularly limited, and conventionally known and publicly available materials can be appropriately used. The preferred material is JI
SA 1050, 1100, 1200, 300
3, 3103, and 3005 materials. The thickness of the aluminum plate used in the present invention is from about 0.1 mm to
It is about 0.6 mm. Prior to the surface roughening treatment of the aluminum plate, a degreasing treatment, for example, a treatment with a surfactant or an alkaline aqueous solution, for removing the surface pressing oil is performed as necessary.

(Roughening and Anodizing) The surface of the aluminum plate can be roughened mechanically, electrochemically dissolved and roughened, and chemically. There is a method of selectively dissolving the surface.
As the mechanical method, a known method called a ball polishing method, a brush polishing method, a blast polishing method, a buff polishing method, or the like can be used. Further, as an electrochemical surface roughening method, there is a method of performing an alternating or direct current in a hydrochloric acid or nitric acid electrolyte. Further, as disclosed in JP-A-54-63902, a method in which both are combined can also be used.

The aluminum plate thus roughened is subjected to an alkali etching treatment and a neutralization treatment, if necessary, and then subjected to an anodic oxidation treatment to increase the water retention and abrasion resistance of the surface. As the electrolyte used for the anodic oxidation treatment of the aluminum plate, any electrolyte that forms a porous oxide film can be used, and generally, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of the electrolyte.

The conditions of the anodizing treatment vary depending on the electrolyte used, and thus cannot be specified. However, generally, the concentration of the electrolyte is 1 to 80% solution, the liquid temperature is 5 to 70 ° C., and the current density is 5 to 60 A. / dm ² , a voltage of 1 to 100 V, and an electrolysis time of 10 seconds to 5 minutes are appropriate.

[0081] The amount of the anodized film is 1.0 g / m ² or more is preferred, more preferably from 2.0 to 6.0 g / m ^2. When the anodic oxide film is less than 1.0 g / m ² , the printing durability is insufficient, or the non-image portion of the lithographic printing plate is easily scratched, and the ink adheres to the scratched portion during printing. "Scratch dirt" is likely to occur.

[0082] Although such anodizing treatment is performed on a surface used for printing of the support of the lithographic printing plate, the back around the electric lines of force, on the back surface of 0.01 to 3 g / m ² anode Generally, an oxide film is formed.

(Silica Treatment) The silicate treatment is one of the hydrophilization treatments used after the above-described treatment, and specifically, US Pat. Nos. 2,714,066 and 318,146.
No. 1, 3,280,734 and 3,902,734, there is an alkali metal silicate plate (for example, sodium silicate aqueous solution) method. In this method, the support is immersed in an aqueous solution of sodium silicate or electrolytically treated.

The silicate treatment will be described below.

The anodic oxide film of the aluminum plate treated as described above was coated with an alkali metal silicate of 0.1 to 30%.
% By weight, preferably 0.5 to 10% by weight,
Aqueous solution having a pH of 10 to 13, for example, 15 to 8
Immerse at 0 ° C for 0.5-120 seconds. If the pH of the alkali metal silicate aqueous solution is lower than 10, the solution gels, and if it is higher than 13.0, the oxide film is dissolved. As the alkali metal silicate used in the present invention, sodium silicate, potassium silicate, lithium silicate and the like are used. Hydroxides used for increasing the pH of the aqueous alkali metal silicate solution include sodium hydroxide, potassium hydroxide, and lithium hydroxide. In addition, alkaline earth metal salts or Group IVB (Group 4A, that is,
Group) metal salts may be blended. Examples of the alkaline earth metal salts include nitrates such as calcium nitrate, strontium nitrate, magnesium nitrate, and barium nitrate, and water-soluble salts such as sulfate, hydrochloride, phosphate, acetate, oxalate, and borate. can give. Group IVB metal salts include titanium tetrachloride, titanium trichloride, potassium potassium fluoride, titanium potassium oxalate, titanium sulfate, titanium tetraiodide, zirconium chloride, zirconium dioxide, zirconium oxychloride, zirconium tetrachloride, etc. Can be. Alkaline earth metal salts or Group IVB metal salts can be used alone or in combination of two or more. A preferred range of these metal salts is 0.01 to 10% by weight,
A more preferred range is from 0.05 to 5.0% by weight.

Since the silicate treatment further improves the hydrophilicity on the aluminum plate surface, the ink hardly adheres to the non-image area during printing, and the stain performance is improved.

(Backcoat) On the back surface of the support, a backcoat is provided if necessary. Examples of such a back coat include a coating composed of an organic polymer compound described in JP-A-5-45885 and a metal oxide obtained by hydrolyzing and polycondensing an organic or inorganic metal compound described in JP-A-6-35174. Layers are preferably used.

Of these coating layers, Si (OC
_{H 3) 4, Si (OC} 2 H 5) 4, Si (OC 3 H 7) 4, Si
Alkoxy compounds of silicon such as (OC ₄ H ₉ ) ₄ are particularly inexpensive and readily available, and a coating layer of a metal oxide provided therefrom is particularly preferred because of its excellent development resistance.

[(D) Oxygen-Blocking Protective Layer] If necessary, the (D) oxygen-blocking protective layer may be further provided on the (B) photopolymerizable photosensitive layer of the present invention. (D) Examples of the water-soluble vinyl polymer contained in the oxygen-barrier protective layer include polyvinyl alcohol, and partial esters and ethers thereof.
And acetal, or copolymers thereof containing substantial amounts of unsubstituted vinyl alcohol units to impart the necessary water solubility to them. Polyvinyl alcohol is hydrolyzed by 71 to 100% and has a degree of polymerization of 3
Those having a range of from 00 to 2400 are exemplified. Specifically, Kuraray's PVA-105, PVA-110, P
VA-117, PVA-117H, PVA-120, P
VA-124, PVA-124H, PVA-CS, PV
A-CST, PVA-HC, PVA-203, PVA-
204, PVA-205, PVA-210, PVA-2
17, PVA-220, PVA-224, PVA-21
7EE, PVA-217E, PVA-220E, PVA
-224E, PVA-405, PVA-420, PVA
-613, L-8 and the like. Examples of the copolymer include 88-100% hydrolyzed polyvinyl acetate chloroacetate or propionate, polyvinyl formal and polyvinyl acetal, and copolymers thereof. Other useful polymers include polyvinylpyrrolidone, gelatin and gum arabic, and these may be used alone or in combination.

The solvent used for coating the oxygen-barrier protective layer of the present invention is preferably pure water, but alcohols such as methanol and ethanol, and ketones such as acetone and methyl ethyl ketone may be mixed with pure water. . The concentration of the solid content in the coating solution is suitably from 1 to 20% by weight.

The oxygen-barrier protective layer of the present invention may further contain known additives such as a surfactant for improving coating properties and a water-soluble plasticizer for improving physical properties of the film. Examples of the water-soluble plasticizer include polyethylene glycol, polypropylene glycol, propionamide,
There are cyclohexanediol, glycerin, sorbitol and the like. Further, a water-soluble (meth) acrylic polymer or the like may be added.

The coating amount is 0.1 to 15 by weight after drying.
A range of g / m ² is appropriate. Preferably 0.5 to 10 g / m ²
It is. More preferably, it is 1 to 5 g / m ² .

The photosensitive lithographic printing plate thus obtained was
r laser (488 nm, 514.5 nm), second harmonic of semiconductor laser (SHG-LD, 350-600 nm),
After being directly exposed by a YAG-SHG laser (532 nm) or the like, it is developed.

As the developing solution used in the developing treatment, a conventionally known alkaline aqueous solution can be used. For example, sodium silicate, potassium, tribasic sodium, potassium, ammonium, sodium diphosphate, potassium, ammonium, sodium carbonate,
Inorganic alkali agents such as potassium, ammonium, sodium bicarbonate, potassium, ammonium, sodium borate, potassium, ammonium, sodium hydroxide, ammonium, potassium, and lithium. Also, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine,
Diisopropylamine, triisopropylamine, n-
Organic alkali agents such as butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, ethyleneimine, ethylenediamine and pyridine are also used.

These alkaline agents are used alone or in combination of two or more. Among the above-mentioned alkaline aqueous solutions, the developing solution in which the effect of the present invention is further exhibited is an aqueous solution containing an alkali metal silicate and having a pH of 12 or more. The aqueous solution of the alkali metal silicate depends on the ratio (generally represented by the molar ratio of [SiO ₂ ] / [M ₂ O]) of silicon oxide SiO ₂ and the alkali metal oxide M ₂ O, which are the components of the silicate, and the concentration. The developing property can be adjusted. For example, as disclosed in JP-A-54-62004,
When the molar ratio of iO ₂ / Na ₂ O is 1.0 to 1.5 (that is, [Si
O ₂ ] / [Na ₂ O] is 1.0 to 1.5, and SiO 2
₂ is an aqueous solution of sodium silicate having a content of 1 to 4% by weight, or [SiO ₂ ] / [M] is 0.5 to 0.75 (as described in JP-B-57-7427). That is, [SiO ₂ ] / [M ₂ O] is 1.0 to 1.5),
The concentration of SiO ₂ is from 1 to 4 wt%, and an alkali metal silicate which in the total alkali metal gram atom developing liquid is present therein as a reference consisting of to contain potassium of at least 20% Acid salts are preferably used.

Further, when developing a photopolymerizable lithographic printing plate using an automatic developing machine, an aqueous solution (replenisher) having a higher alkali strength than the developing solution is added to the developing solution.
It is known that a large amount of a photopolymerizable lithographic printing plate can be processed without replacing the developing solution in the developing tank for a long time. This replenishment system is also preferably applied in the present invention. For example, [SiO ₂ ] / [Na] of a developer as disclosed in JP-A-54-62004 is used.
₂ O] is 1.0 to 1.5 (ie, [SiO ₂ ] /
[Na ₂ O] is 1.0 to 1.5), and an aqueous solution of sodium silicate having a SiO ₂ content of 1 to 4% by weight is used. Continuously or intermittently, the molar ratio of SiO ₂ / Na ₂ O is 0.5 to
1.5 (that is, [SiO ₂ ] / [Na ₂ O] is 0.5-1.
5) A method of adding an aqueous solution of sodium silicate (replenisher) to a developer, and further disclosed in JP-B-57-7427, where [SiO ₂ ] / [M] is 0.5 to 0.75.
(That is, [SiO ₂ ] / [M ₂ O] is 1.0 to 1.5), and a developer of an alkali metal silicate having a SiO ₂ concentration of 1 to 4% by weight is replenished. [SiO ₂ ] / [M] of the alkali metal silicate used as the solution is 0.25 to 0.25
0.75 (that is, [SiO ₂ ] / [M ₂ O] is 0.5-1.
5) and wherein both such developer and replenisher contain at least 20% potassium, based on gram atoms of total alkali metal present therein. It is preferably used.

The photopolymerizable lithographic printing plate thus developed is described in JP-A-54-8002 and JP-A-55-1150.
As described in JP-A Nos. 45 and 59-58431 and the like, post-treatment is carried out with washing water, a rinsing solution containing a surfactant and the like, and a desensitizing solution containing gum arabic and a starch derivative. . In the post-treatment of the photopolymerizable lithographic printing plate of the present invention, these treatments can be used in various combinations.

The lithographic printing plate obtained by such a process is set on an offset printing machine and used for printing a large number of sheets.

As a plate cleaner used for removing stains on a plate during printing, a conventionally known PS cleaner is used.
A plate cleaner for plates is used, for example, CL-
1, CL-2, CP, CN-4, CN, CG-1, PC
-1, SR, IC (manufactured by Fuji Photo Film Co., Ltd.) and the like.

[0100]

Next, examples of the present invention will be described in detail with reference to comparative examples. All percentages in the following Examples and Comparative Examples are% by weight unless otherwise specified.

(Examples 1 to 3, Comparative Example 1) Thickness 0.24
The surface of a JIS A1050 mm aluminum plate was grained using a nylon brush and an aqueous suspension of pumicestone of 400 mesh, and then thoroughly washed with water. After etching by dipping in a 10% aqueous sodium hydroxide solution at 70 ° C. for 60 seconds, the substrate was washed with running water, washed with 20% HNO ₃ for neutralization, and washed with water. This was subjected to electrolytic surface roughening treatment in a 1% nitric acid aqueous solution at an anode electricity of 260 coulomb / dm ² using a sinusoidal alternating waveform current under the condition of V _A = 12.7 V. When the surface roughness was measured, it was 0.45 μm (Ra indication). Subsequently, it was immersed in a 30% aqueous solution of H ₂ SO _{4 and} desmutted at 55 ° C. for 2 minutes.
_The substrate [A] was prepared by anodic oxidation in a ₂ SO ₄ aqueous solution so that the current density was 5 A / dm ² and the amount of the anodic oxide film was equivalent to 2.5 g / m ² , followed by washing with water.

The substrate [A] was prepared by adding 2.5% by weight of sodium silicate.
The substrate was treated with an aqueous solution at 70 ° C. for 10 seconds and washed with water to form a substrate [B].

The polymer compound of the present invention shown in Table 1 was applied to the surface of the substrate [B] treated in this manner.
Dry at 15 ° C. for 15 seconds. The coating amount after drying is 15 mg / m ²
Met.

The polymer compound of Table 1 0.3 g methanol 100 g water 1 g

Thus, the polymer compound No.
Substrates B-1, B-2, and B-3 were prepared according to 2, 8, and 11, respectively. Further, a substrate B without an intermediate layer of a polymer compound
-4 was created.

On the substrate thus treated, a photopolymerizable composition 1 having the following composition was applied so as to have a dry coating weight of 1.4 g / m ^2, and dried at 80 ° C. for 2 minutes. A photosensitive layer was formed.

[Photopolymerizable Composition 1] Trimethylolpropane tri (acryloyloxypropyl) ether 1.5 g Allyl methacrylate / methacrylic acid (80/20 weight ratio) linear organic polymer polymer Mw = 40,000 (B ₁ ) 2.0 g The following sensitizer (C ₁ ) (λmax THF (tetrahydrofuran) 472 nm, ε = 7.4 × 10 ⁴ ) 0.13 g The following photoinitiator (D ₁ ) 0.09 g The following thio compound ( E ₁ ) 0.08 g Fluorinated nonionic surfactant 0.03 g Methyl ethyl ketone 20.0 g Propylene glycol monomethyl ether acetate 20.0 g

[0108]

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[0109]

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[0110]

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A 3% by weight aqueous solution of polyvinyl alcohol (degree of saponification: 86.5 to 89 mol%, degree of polymerization: 1000) was coated on the photosensitive layer so that the dry coating weight was 2 g / m ^2, and 100 ° C. For 2 minutes to obtain a photopolymerizable lithographic printing plate. The printing plate was stored at 60 ° C. for 3 days.

[0112] These plates were used with XLP4 manufactured by Optronics.
000 high-definition laser plotter (air-cooled Ar laser 2
00mW, 488nm) at various energies and 400
Halftone dots and solid portions were exposed under the conditions of 0 dpi and 175 lines / inch. Then 110 to further increase the degree of film hardening
A post-heating treatment was performed at 12 ° C. for 12 seconds. The development was carried out using 850NX manufactured by Fuji Photo Film Co., Ltd. using a developer obtained by diluting a 10-fold diluted LP-D developer with water and subjecting the above printing plate to 10 m ² development processing per liter of the solution in advance.
The immersion was performed at 30 ° C. for 15 seconds using an automatic developing machine.

For evaluation of printing durability, SOR-KZ manufactured by Heidelberg Co. was used as a printing machine, emerald premium MXE 2% diluted solution of Anchor Co., Ltd. was used as dampening solution, and GEOS-G (N )It was used.
Printed materials were sampled every 5,000 sheets, 2% of 175 lines / inch were evaluated, and the number of sheets considered to be at an acceptable level for practical use was evaluated.

The stainability of the non-image area was visually evaluated on a 10-point scale. Ten points are the least stained, and one point is the most easily stained. Six points are regarded as practically acceptable levels. Table 1 shows the results.

[0115]

[Table 1]

By using the compound of the present invention, a negative-working polymerizable lithographic printing plate having excellent highlight printing durability and stain resistance was obtained.

[0117]

According to the present invention, it is possible to obtain a photopolymerizable lithographic printing plate which is excellent in printing durability and has less stain on a non-image area.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Mitsuhiro Imaizumi 4,000 Kawajiri, Yoshida-cho, Haibara-gun, Shizuoka Prefecture F-term in Fujisha Shin Film Co., Ltd. BA05 BA16 CA01 CA02 CA05 EA04

Claims (1)

[Claims] Claims 1. An anodic oxide film is provided, and then obtained on a substrate made of silicate-treated aluminum or an aluminum alloy by using a component having an acid group and a component having an onium group. A polymer having at least one ethylenically unsaturated bond polymerizable by actinic light, a linear organic polymer, and a photopolymerization initiator. And a photopolymerizable lithographic printing plate having a photopolymerizable photosensitive layer.