JP2001264978A - Photosensitive planographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive planographic printing plate having high sensitivity at the wavelength of light emitted from a low-cost short-wavelength semiconductor laser, handleable under bright safelight, excellent in printing resistance because the adhesive strength of a photosensitive layer to the substrate is not impaired and excellent in dot reproducibility because the thickening of dots by scattered light due to the substrate is hardly caused. SOLUTION: The photosensitive planographic printing plate has a photosensitive layer on an aluminum substrate subjected to at least surface roughening and anodic oxidation, micropores present in an anodic oxide coating on the substrate has 5-10 nm pore diameter and 8×1015-2×1016/m2 pore density and the photosensitive layer contains (i) a titanocene compound, (ii) an addition polymerizable compound having an ethylenically unsaturated double bond and (iii) a pigment having such an optical characteristic that the transmittance at 500 nm is relatively lower than that at 400 nm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive lithographic printing plate, and more particularly to a photosensitive lithographic printing plate which is highly sensitive to the emission wavelength of an inexpensive short-wavelength semiconductor laser and can be handled under a bright safelight. The present invention relates to a planographic printing plate, a photosensitive planographic printing plate having excellent laser exposure suitability and excellent dot reproducibility.

[0002]

2. Description of the Related Art Conventionally, as a photosensitive lithographic printing plate, a PS plate having a structure in which a lipophilic photosensitive resin is provided on a hydrophilic support is widely used, and a lithographic printing plate is made from the PS plate. As a method, usually, a desired printing plate has been obtained by dissolving and removing a non-image portion after mask exposure (surface exposure) through a lith film. In recent years, digitalization techniques for electronically processing, storing, and outputting image information using a computer have become widespread, and various new image output methods corresponding to the technology have come into practical use. As a result, computer-to-plate (CTP) technology for scanning a highly directional light such as a laser beam in accordance with digitized image information and manufacturing a printing plate directly without passing through a lithographic film is desired, and a lithographic plate adapted to this is desired. Original plates for printing plates have been developed.

[0003] In such a photopolymer CTP system, a photosensitive material having a high sensitivity near 500 nm is used in order to cope with an Ar laser (488 nm) and an FD-YAG laser (532 nm). It is necessary to perform the operation under a dark red light safelight, and the workability is remarkably poor, and improvement has been desired. For this reason, light-sensitive materials sensitive to shorter wavelengths have been studied, and work under brighter safelights is becoming possible.

However, since the photosensitive lithographic printing plate as described above is drawn with a laser beam, it is susceptible to light scattered by a support, and a thin image portion called a fringe is formed around each halftone dot. Will occur. For this reason, it has been pointed out that the entire dot becomes slightly thick and the dot area ratio becomes high. The substrate of the lithographic printing plate is usually subjected to anodizing treatment in order to increase the photosensitive layer adhesion and the plate surface strength, and in addition to increase the water retention of the dampening solution and enhance the printing suitability. Since the anodic oxide film has a certain level of light absorption in the wavelength range of 488 to 532 nm used for ordinary laser exposure, the effect of laser light scattering is still acceptable although it is affected.

However, in order to improve workability,
In a recently developed photosensitive lithographic printing plate described in Japanese Patent Application No. 11-209822, which is sensitive to a short wavelength of 450 nm or less, the light absorption at an exposure wavelength of 450 nm or less is less than the conventional 500 nm for an anodized film. The influence of halftone dot fluctuation due to laser light scattering is even more severe as compared with the wavelengths before and after. In this case, it is better to increase the light absorption of the anodic oxide film, but for that purpose, by reducing the pore diameter of micropores called micropores present in the anodic oxide film or reducing the number of pores per unit area It is necessary to increase the volume fraction of the oxide film itself. However, on the other hand, the micropores of the anodized aluminum film hold the photosensitive layer by an anchor effect and obtain adhesion, so that the micropores are reduced and the number of pores per unit area is reduced, that is, The adhesiveness of the photosensitive layer is impaired, and it cannot be used practically. Therefore, it is necessary to have a certain amount of micropores in order to obtain the adhesion by the support, and hitherto, halftone dot quality and reproducibility have to be sacrificed in order to form an image and use it as a printing plate.

[0006]

Accordingly, the present invention provides a photosensitive lithographic printing plate which does not deteriorate the halftone dots due to the scattered light caused by the support as described above, without impairing the adhesion of the photosensitive layer. What you want to do.

[0007]

First, the absorption of laser light means that the light incident on the film is absorbed by the film and converted into heat energy etc. while the light is repeatedly scattered within the film without being emitted to the outside of the film. Means Although the anodic oxide film itself has a certain level of light absorbing ability, the presence of micropores with the same film thickness creates air in the film. Therefore, if the number of micropores increases or the pore diameter increases, the ratio of air to the film increases, and the volume fraction of the light absorbing portion decreases. It tends to increase. However, the micropores are the bases of the anchor effect that contributes to the adhesion of the photosensitive layer, and the diameter /
The number per unit area greatly affects the anchor effect.
As the number of micropores increases or the pore diameter increases, the anchor effect naturally increases. In order to increase the volume fraction as much as possible without impairing the anchor effect by the anodic oxide film, it is sufficient to reduce the pore diameter of the micropore and increase the number of pores per unit area, but if the pore diameter is too small, it is sufficient The anchor effect cannot be obtained. As a result of diligent efforts to overcome this, the following invention was obtained.

That is, the present invention relates to a photosensitive lithographic printing plate having a photosensitive layer on an aluminum support which has been subjected to at least a roughening treatment and an anodic oxidation treatment, wherein the lithographic printing plate has an anodic oxide film on the support. The micropore has a pore diameter of 5 to 10 nm,
Having a pore density of 8 × 10 ^{15 to} 2 × 10 ¹⁶ / m ² , wherein the photosensitive layer comprises (i) at least one kind of titanocene compound;
i) an addition polymerizable compound having at least one ethylenically unsaturated double bond and (iii) at least one pigment having an optical property that the transmittance at 500 nm is smaller than the transmittance at 400 nm. It is a photosensitive lithographic printing plate characterized by containing.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. [Aluminum support] The aluminum support used in the photosensitive lithographic printing plate of the present invention is a metal whose main component is dimensionally stable aluminum. It is selected from an alloy plate containing a trace amount of a different element or a plastic film or paper on which aluminum (alloy) is laminated or vapor-deposited. In the following description, the above-mentioned substrates made of aluminum or an aluminum alloy are collectively used as aluminum substrates. The foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel and titanium, and the content of the foreign elements in the alloy is 10% by weight or less. In the present invention, a pure aluminum plate is preferable, but completely pure aluminum is difficult to produce due to refining technology, and therefore may contain a slightly different element. Thus, the aluminum plate applied to the present invention, the composition is not specified, the conventionally known and used materials,
For example, JIS A 1050, JISA 1100, J
IS A 3103 and JIS A 3005 can be used as appropriate. The thickness of the aluminum substrate used in the present invention is approximately 0.1 mm to 0.6 mm.
It is about. This thickness can be appropriately changed according to the size of the printing press, the size of the printing plate, and the user's request. The aluminum substrate may be appropriately subjected to a substrate surface treatment described later as necessary. Of course, it need not be applied.

[Roughening treatment] The roughening method includes mechanical roughening, chemical etching, electrolytic graining and the like as disclosed in JP-A-56-28893. Furthermore, an electrochemical surface roughening method of electrochemically roughening in an electrolytic solution of hydrochloric acid or nitric acid, a wire brush graining method in which the aluminum surface is scratched with a metal wire, and the aluminum surface is sanded with a polishing ball and an abrasive. A mechanical graining method such as a pole grain method, a brush grain method for roughening the surface with a nylon brush and an abrasive can be used, and the above roughening methods can be used alone or in combination. Among them, a method usefully used for surface roughening is an electrochemical method in which the surface is chemically roughened in a hydrochloric acid or nitric acid electrolytic solution, and a suitable amount of electricity at the time of anode is 50 C / dm.
It is in the range of ^{2 to} 400 C / dm ² . More specifically,
In an electrolytic solution containing 0.1 to 50% hydrochloric acid or nitric acid, a temperature of 20 to 80 ° C., a time of 1 second to 30 minutes, and a current density of 100 C /
It is preferable to carry out AC and / or DC electrolysis under the conditions of dm ^{2 to} 400 C / dm ² .

The aluminum substrate thus roughened may be chemically etched with an acid or an alkali. Preferable etching agents are caustic soda, sodium carbonate, sodium aluminate, sodium metasilicate, sodium phosphate, potassium hydroxide, lithium hydroxide and the like.
%, 20 to 100 ° C. After etching, pickling is performed to remove dirt (smut) remaining on the surface. The acids used are nitric acid, sulfuric acid, phosphoric acid, chromic acid,
Hydrofluoric acid, borofluoric acid and the like are used. In particular, as a method of removing the smut after the electrochemical surface-roughening treatment, a method of contacting with 15 to 65% by weight of sulfuric acid at a temperature of 50 to 90 ° C as described in JP-A-53-12739 is preferred. And an alkali etching method described in JP-B-48-28123. After the treatment as described above, the method conditions are not particularly limited as long as the center line average roughness Ra of the treated surface is 0.2 to 0.5 μm.

[Anodic Oxidation Treatment] The aluminum substrate thus treated to form an oxide layer is thereafter subjected to an anodic oxidation treatment. Anodizing treatment is sulfuric acid, phosphoric acid,
An aqueous solution of oxalic acid or boric acid / sodium borate is used singly or in combination of two or more as the main component of the electrolytic bath. At this time, at least an Al alloy plate in the electrolyte,
Components normally contained in electrodes, tap water, groundwater and the like may of course be contained. Furthermore, the second and third components may be added. Here, the second and third components include, for example, Na, K, Mg, Li, Ca, Ti, Al, V, and C.
cations to metal ions such as r, Mn, Fe, Co, Ni, Cu, Zn, ammonium ions, etc., nitrate ions, carbonate ions, chloride ions, phosphate ions, fluorine ions, sulfite ions, titanate ions, Silicate ions,
Anions such as borate ions may be mentioned, and the concentration may be about 0 to 10000 ppm. The conditions of the anodizing treatment are not particularly limited, but are preferably 30 to 500.
g / liter, a processing solution temperature of 10 to 70 ° C., and a current density of 0.
It is processed by DC or AC electrolysis in the range of 1 to 40 A / m ² . The thickness of the formed anodized film is 0.5 to
The range is 1.5 μm. Preferably 0.5-1.0μ
m. The support prepared by the above-described process is used when the pore diameter of the micropores existing in the anodic oxide film is 5
〜１０10 nm, pore density 8 × 10 ¹⁵ 〜2 × 10 ¹⁶ / m
Processing conditions must be selected to fall within the range of ² .

[Photosensitive layer] Next, the photosensitive layer used in the photosensitive lithographic printing plate of the present invention will be described. The photosensitive layer used in the photosensitive lithographic printing plate of the present invention comprises (i) at least one titanocene compound, (ii) an addition polymerizable compound having at least one ethylenically unsaturated double bond, and (iii) 400 nm. Contains at least one pigment having an optical property that the transmittance at 500 nm is relatively smaller than the transmittance at.

[(I) Titanocene compound] The titanocene compound contained in the photosensitive layer of the photosensitive lithographic printing plate according to the present invention, if necessary, is irradiated with light in the presence of a sensitizing dye described below to form an active species. Any titanocene compound that can be generated may be used. Examples of such titanocene compounds include, for example, JP-A-59-152396 and JP-A-6-152396.
1-1151197, JP-A-63-41483, JP-A-63-41484, JP-A-2-249, JP-A-2-241
-291, JP-A-3-27393, JP-A-3-12
Known compounds described in JP-A-403-403 and JP-A-6-41170 can be appropriately selected and used.

More specifically, di-cyclopentadienyl-Ti-di-chloride, di-cyclopentadienyl-Ti-bis-phenyl, di-cyclopentadienyl-Ti-bis-2,3,3 4,5,6-pentafluorophenyl-1-yl, di-cyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophenyl-1-yl, di-cyclopentadienyl-Ti- Screw-2,4
6-trifluorophenyl-1-yl, di-cyclopentadienyl-Ti-bis-2,6-difluorophenyl-1
-Yl, di-cyclopentadienyl-Ti-bis-2,
4-difluorophenyl-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluorophenyl-1-yl, di-methylcyclopentadienyl-Ti -Bis-2,3,5,6-tetrafluorophenyl-1-yl, di-methylcyclopentadienyl-Ti-bis-2,4-difluorophenyl-1-yl,
Bis (cyclopentadienyl) -bis (2,6-difluoro-3- (pyr-1-yl) phenyl) titanium and the like can be mentioned.

Further, these titanocene compounds can be subjected to various chemical modifications for improving the properties of the photosensitive layer. For example, sensitizing dyes described below, binding to addition polymerizable unsaturated compounds and other activator parts, introduction of hydrophilic sites, improvement of compatibility, introduction of substituents for suppressing crystal precipitation, substitution for improving adhesion. Methods such as group introduction and polymerization can be used. In addition, the method of use can be appropriately set as appropriate according to the performance design of the photosensitive lithographic printing plate to be applied. For example, by using two or more kinds, the compatibility with the photosensitive layer or the like can be increased. A larger amount of the titanocene compound is generally advantageous in terms of photosensitivity, and is preferably 0.5 to 80 parts by weight, based on 100 parts by weight of all components such as the photosensitive layer.
Sufficient photosensitivity can be obtained by using preferably 1 to 50 parts by weight. On the other hand, when used in white lighting such as yellow, it is preferable that the amount used is small from the viewpoint of fogging due to light near 500 nm. By increasing the content, sufficient photosensitivity can be obtained even when the used amount is reduced to 6 parts by weight or less, further 1.9 parts by weight or less, and further to 1.4 parts by weight or less.

[(Ii) Addition-polymerizable compound having at least one ethylenically unsaturated double bond] Next, at least one compound contained in the photosensitive layer of the photosensitive lithographic printing plate of the present invention.
The addition polymerizable compound having two ethylenically unsaturated double bonds (hereinafter, also simply referred to as an addition polymerizable compound) will be described. The addition polymerizable compound contained in the photosensitive layer of the photosensitive lithographic printing plate of the present invention is selected from compounds having at least one, and preferably two or more, terminal ethylenically unsaturated bonds. Such compounds are widely known in the industrial field, and they can be used in the invention without any particular limitation. These are, for example, monomers,
It has a chemical form such as a prepolymer, ie, a dimer, a trimer and an oligomer, or a mixture thereof and a copolymer thereof. Examples of monomers and their copolymers include unsaturated carboxylic acids (eg, acrylic acid,
Methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.), esters and amides thereof, preferably esters of unsaturated carboxylic acids and aliphatic polyhydric alcohol compounds, unsaturated carboxylic acids An amide of the compound and an aliphatic polyamine compound is used. Further, an unsaturated carboxylic acid ester having a nucleophilic substituent such as a hydroxyl group, an amino group or a mercapto group, an addition reaction product of an amide with a monofunctional or polyfunctional isocyanate, an epoxy, a monofunctional or A dehydration-condensation reaction product with a functional carboxylic acid is also preferably used.

Unsaturated carboxylic acid esters having an electrophilic substituent such as an isocyanato group or an epoxy group;
Addition products of amides with monofunctional or polyfunctional alcohols, amines, thiols, unsaturated carboxylic esters having elimination substituents such as halogen groups and tosyloxy groups, amides and monofunctional Alternatively, a substitution product with a polyfunctional alcohol, amine, or thiol is also suitable. As another example, it is also possible to use a group of compounds in which unsaturated phosphonic acid, styrene, vinyl ether or the like is substituted for the above unsaturated carboxylic acid.

Specific examples of the ester monomer of the aliphatic polyhydric alcohol compound and the unsaturated carboxylic acid include acrylates 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 1,4-cyclohexanediol diacrylate, tetraethylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate , So Bi penta acrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, polyester acrylate oligomer.

Examples of methacrylic acid esters 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.

The crotonates include 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. Examples of other esters include:
For example, JP-B-46-27926, JP-B-51-473.
34, aliphatic alcohol esters described in JP-A-57-196231, JP-A-59-5240 and JP-A-59-196231.
No. 5,241, those having an aromatic skeleton described in JP-A-2-226149 and those containing an amino group described in JP-A-1-165613 are also suitably used. Further, the above-mentioned ester monomers can be used as a mixture.

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. Examples of other preferable amide monomers include those having a cyclohexylene structure described in JP-B-54-21726.

A urethane-based addition-polymerizable compound produced by an addition reaction between an isocyanate and a hydroxyl group is also suitable.
JP-A-8-41708 discloses a polyisocyanate compound having two or more isocyanate groups in one molecule to which a hydroxyl-containing vinyl monomer represented by the following formula (I) is added. And vinyl urethane compounds containing at least two polymerizable vinyl groups.

CH ₂ ＣC (R) COOCH ₂ CH (R ′) OH Formula (I) (where R and R ′ represent H or CH ₃ )

Also, urethane acrylates described in JP-A-51-37193, JP-B-2-32293 and JP-B-2-16765, and
No. 49860, No. 56-17654, No. 62
Urethane compounds having an ethylene oxide skeleton described in JP-B-39417 and JP-B-62-39418 are also suitable.

Further, by using addition polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277653, JP-A-63-260909 and JP-A-1-105238. Can obtain a photosensitive composition having an extremely high photosensitive speed.

As another example, see JP-A-48-641.
No. 83, JP-B-49-43191, JP-B-52-30
No. 490, 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 each publication. Also,
JP-B-46-43946, JP-B-1-40337,
Specific unsaturated compounds described in JP-B-1-40336,
Vinyl phosphonic acid compounds described in JP-A-2-25493 can also be mentioned. In some cases, a structure containing a perfluoroalkyl group described in JP-A-61-22048 is preferably used. Furthermore, Japan Adhesion Association Journal vol. 20, No. 7, pages 300-308 (198
(4 years) as photocurable monomers and oligomers can also be used.

Regarding these addition polymerizable compounds, what kind of structure is used, whether they are used alone or in combination,
Details of the method of use, such as the amount of addition, can be arbitrarily set in accordance with the performance design of the final photosensitive lithographic printing plate. For example, it is selected from the following viewpoints. A structure having a large content of unsaturated groups per molecule is preferable from the viewpoint of the photosensitive speed, and in many cases, a bifunctional or more functional structure is preferable. Also, in order to increase the strength of the image area, that is, the cured film,
A compound having three or more functional groups is preferred. Furthermore, by using a combination of different functional groups and different polymerizable groups (for example, acrylic ester, methacrylic ester, styrene-based compound, and vinyl ether-based compound), photosensitivity and strength can be improved. A method of adjusting both is also effective. Large molecular weight compounds,
A compound having high hydrophobicity is excellent in photosensitive speed and film strength, but may not be preferable in terms of developing speed and precipitation in a developing solution. In addition, the selection and use of the addition polymerization compound is also an important factor with respect to compatibility and dispersibility with other components (eg, a binder polymer, an initiator, a colorant, and the like) in the photosensitive layer. Use of low-purity compounds,
The compatibility may be improved by using two or more kinds in combination.
In addition, a specific structure may be selected for the purpose of improving the adhesion between the photosensitive layer and a support, an overcoat layer, and the like described below. Regarding the compounding ratio of the addition polymerizable compound in the photosensitive layer, a larger amount is advantageous in sensitivity, but if it is too large, undesired phase separation occurs or the production process due to the stickiness of the photosensitive layer. Problems (for example, poor production resulting from transfer of the photosensitive material components and adhesion) and problems such as precipitation from the developer may occur. From these viewpoints, the preferred compounding ratio is, in many cases, from 5 to 80% by weight, and preferably from 25 to 75% by weight, based on all components of the photosensitive layer. These may be used alone or in combination of two or more. others,
The method of using the addition-polymerizable compound can be arbitrarily selected from the viewpoint of the degree of polymerization inhibition for oxygen, resolution, fogging, refractive index change, surface tackiness, etc.
In some cases, layer composition such as undercoat and overcoat
A coating method can also be implemented.

[(Iii) Pigment having optical characteristics in which the transmittance at 500 nm is relatively smaller than the transmittance at 400 nm] Next, 400 nm contained in the photosensitive layer of the photosensitive lithographic printing plate of the present invention. 500 than the transmittance at
A pigment having an optical property whose transmittance in nm is relatively small will be described. In the present invention, the pigment is 400
Any material can be used without particular limitation as long as it has optical characteristics in which the transmittance at 500 nm is relatively smaller than the transmittance at 500 nm. The optical properties of the pigment can be adjusted by appropriately selecting the chemical structure of the coloring substance constituting the pigment and the dispersion state (particle size, dilution state, etc.). Also,
Its optical properties can be easily examined, for example, by preparing a pigment dispersion film on an optically transparent support and measuring the transmittance using a general-purpose spectrophotometer. Even in the case of a film, it can be actually measured as the reciprocal of the reflectance determined by the regular reflection measurement method or the diffuse reflection measurement method.

A preferred pigment used in the present invention is Color
Index (Published by The Society of Dyes and Color
(ists, Third Edition).

Azo pigments: for example, Pigment Orange 13, 16,
2,24,31, Pigment Red 1,22,3,38,4,4
8, 49, 60, 63, 9, 166, 144 Pigment Brown 23, etc.

Perylene pigments: For example, Pigment Orange 7, Pigment Red 123, 178, 179, 2
24, 149, 190, Pigment Violet 29, etc.

Pyrazoloquinazolone pigments: for example, Pigment Red 251, 252, Pigment Orange 67, etc., and aminoanthraquinone-based pigments: for example, Pigment Red 177, etc.

Quinacridone pigments: for example, Pigment Violet 19, Pigment Red 122,202, etc. Acid dye lake pigments: For example, Pigment Blue 61, 56, 57, etc. Basic dye lake pigments: For example, Pigment Violet 1 Pigment Red 81 etc.

Other pigments: for example French U
tramarine and the like. ,

In the present invention, if the coloring compound constituting the pigment takes a molecular dispersion state (dissolution) instead of a solid dispersion in the photosensitive layer, adverse effects such as an increase in fog or desensitization occur. It is preferable to use a pigment having as little influence as possible. From the viewpoint of absorption spectrum characteristics and solubility caused by the chemical structure of the pigment component, azo pigments, perylene pigments, pyrazoloquinazolone pigments, pyrazoloquinazolone pigments, and aminoanthraquinone pigments are suitable as the pigment of the present invention. And quinacridone pigments, acid dye lake pigments, and basic dye lake pigments, and more preferably azo pigments, acid dye lake pigments, pyrazoloquinazolone pigments, and quinacridone pigments. The chemical structural formulas of the coloring substances constituting the preferred pigment are shown below.

[0039]

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[0040]

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[0041]

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[0042]

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Next, a general method for dispersing a pigment will be described, but the present invention is not limited by these descriptions. Generally, these pigments are supplied after being synthesized and dried by various methods. Usually, it is dried and supplied as a powder body from an aqueous medium, but since water requires a large latent heat of vaporization to dry, a large amount of heat energy is applied to dry it into a powder. Therefore, the pigment usually forms an aggregate (secondary particle) in which the primary particles are aggregated.

It is not easy to disperse the pigment forming such an aggregate into fine particles. Therefore, it is preferable that the pigment is previously treated with various resins. Examples of these resins include a binder resin described below. Examples of the treatment method include a flushing treatment and a kneading method using a kneader, an extruder, a ball mill, a two or three roll mill, or the like. Among them, a flushing treatment and a kneading method using a two- or three-roll mill are suitable for forming fine particles.

The flushing treatment is generally a method in which an aqueous dispersion of a pigment is mixed with a resin solution dissolved in a water-immiscible solvent, the pigment is extracted from an aqueous medium into an organic medium, and the pigment is treated with the resin. . According to this method, since the pigment does not undergo drying, aggregation of the pigment can be prevented and dispersion becomes easy. In kneading with two or three roll mills, a pigment and a resin or a solution of a resin are mixed and then, while applying a high shear (shearing force), the pigment and the resin are kneaded to coat the pigment surface with the resin. And a method of treating a pigment. The pigment particles aggregated in this process are dispersed from lower-order aggregates to primary particles.

A processed pigment previously treated with an acrylic resin, a vinyl chloride-vinyl acetate resin, a maleic acid resin, an ethylcellulose resin, a nitrocellulose resin or the like can also be conveniently used. The form of the processed pigment treated with the various resins is preferably a powder, paste, pellet, or paste in which the resin and the pigment are uniformly dispersed. On the other hand, a non-uniform lump having a gelled resin is not preferable.

In order to obtain a pigment dispersion having a fine particle size distribution, the pigment is first subjected to a flushing treatment or kneaded with a binder resin using a kneader, an extruder, a ball mill, a two or three roll mill. As a preferable kneading method, first, a solvent is added to the pigment and the binder resin, and the mixture is uniformly mixed, and then kneaded while heating using two or three rolls as necessary, so that the pigment and the binder resin are sufficiently blended. There is a method of obtaining a uniform colored body. Next, the pigment is mixed with other components including the pigment dispersant of the present invention and wet-dispersed (primary dispersion).
I do. The obtained dispersion is again subjected to wet dispersion (secondary dispersion) using finer beads until the target particle size distribution is obtained. Alternatively, the wet-dispersed dispersion is separated by centrifugation, or coarse particles are removed by decantation to obtain particles having a desired particle size and size distribution. When a tertiary amine compound, for example, is present as a dispersant in the above-mentioned kneading step or dispersion step, the dispersion of the pigment into fine particles is promoted, which is advantageous for obtaining the particles having the particle size distribution of the present invention. In particular, the following tertiary amine compounds having at least one polymerizable group are preferred. As the polymer group having at least one tertiary amine, any group having at least one polymer can be used. The polymer group is preferably a lower alkyleneoxy group. Here, examples of the lower alkyleneoxy group include polyoxyethylene and polyoxypropylene. More preferably, polyoxyethylene and polyoxypropylene can form a block copolymer. These polymeric groups may be attached to the tertiary amine in any number of 1-3.

For the purpose of improving the dispersibility of the pigment, conventionally known pigment dispersants and surfactants can be added. As these dispersants, many types of compounds are used. For example, phthalocyanine derivatives (commercially available products E
FKA-745 (manufactured by Morishita Sangyo)); organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), (meth) acrylic acid (co) polymer polyflow No. 75, No. 90,
Cationic surfactants such as No. 95 (manufactured by Kyoeisha Yushi Kagaku Kogyo) and W001 (manufactured by Yusho); polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octyl phenyl ether; Polyoxyethylene nonyl phenyl ether, polyethylene glycol dilaurate, polyethylene glycol distearate,
Nonionic surfactants such as sorbitan fatty acid esters;
F-top EF301, EF303, EF352 (manufactured by Shin-Akita Kasei), Megafac F171, F172, F17
3 (manufactured by Dainippon Ink), Florad FC430, FC4
31 (Sumitomo 3M), Asahi Guard AG710,
Surflon S382, SC-101, SC-102, S
C-103, SC-104, SC-105, SC-10
Fluorinated surfactants such as 68 (manufactured by Asahi Glass);
Anionic surfactants such as W005 and W017 (manufactured by Yusho); EFKA-46, EFKA-47, EFKA-47
EA, EFKA polymer 100, EFKA polymer 40
0, EFKA polymer 401, EFKA polymer 450
Polymer dispersants such as Disperse Aid 6, Disperse Aid 8, Disperse Aid 15, Disperse Aid 9100 (manufactured by San Nopco); Solsperse 3000, 5000, 9000, 1200
0, 13240, 13940, 17000, 2400
Various Solsperse dispersants such as 0, 26000 and 28000 (manufactured by Zeneca Corporation); Adecapluronic L3
1, F38, L42, L44, L61, L64, F6
8, L72, P95, F77, P84, F87, P9
4, L101, P103, F108, L121, P-1
23 (manufactured by Asahi Denka) and Isonet S-20 (manufactured by Sanyo Chemical).

Next, a preferred mode of use of the pigment dispersion thus obtained will be described. The average particle size (average size) of the pigment is very important. If the average particle size is large,
Undesirable light scattering occurs, and as a result, when used in a light-sensitive material, its transmittance is reduced, so that light necessary for photopolymerization cannot be applied to the inside of the photosensitive layer. Scattering is particularly remarkable when short-wavelength light is used as a light source.
Therefore, in the case of a photosensitive lithographic printing plate intended to use a relatively short-wave light source as in the present invention, it is preferable that the average particle size of the pigment is as small as possible. The effect of such a decrease in transmittance due to scattering depending on the particle size is remarkable, and the structure of the pigmented substance was selected and the absorption characteristics were appropriately set so that the transmittance at 400 nm was increased. However, if the particle size is large, the transmittance at 400 nm decreases, which causes a substantial decrease in the sensitivity of the photosensitive layer. On the other hand, if the particle size is too small, dispersion stability tends to be insufficient, and undesired problems such as aggregation and sedimentation in the photosensitive layer occur. From these viewpoints, the pigment in the present invention has an average particle size of 0.01 to 0.7 μm, and further 0.01 to 0.4 μm.
m is desirable. More specifically, particles having a size of 0.4 μm or less account for 70% by weight or more of all the particles, more preferably 80% by weight.
% By weight or more and an average particle size of 0.01 to 0.1%.
4 μm, more preferably in the range of 0.02 to 0.35 μm.

The upper limit of the amount of the pigment used is set so that the polymerization reactivity of the components of the photosensitive layer and the developability of the photosensitive lithographic printing plate are not significantly reduced. On the other hand, the lower limit is set so as to obtain a sufficient effect for improving the fogging property. These depend on the optical properties of the individual pigments. Usually 0.001-5
a g / m ^2, preferably 0.05 to 3 g / m ^2, more preferably in the range of 0.1-2 g / m ^2. On the other hand, when viewed in terms of optical characteristics, the photosensitive layer having excellent fog resistance,
The absorbance due to the pigment in nm is 0.1 or more, preferably 0.3 or more, more preferably 0.5 or more.

Further, as a preferable use form of the pigment, various conventionally known techniques can be applied. In particular, JP-A-8
As described in -101498, when the pigment is dispersed, the main chain,
Alternatively, when a polymer having an aliphatic double bond in the side chain is allowed to coexist, a highly sensitive photosensitive layer can be obtained. Other conventional proposals for using pigments in photopolymerization systems include JP-A-10-282647 and JP-A-9-230601.

[Other Components] In the photosensitive layer of the photosensitive lithographic printing plate of the present invention, other components suitable for its use, production method and the like can be appropriately used. [Sensitizing dye] In the photosensitive layer of the photosensitive lithographic printing plate of the present invention, a sensitizing dye is preferably used in combination, if necessary, for the purpose of increasing sensitivity. When this sensitizing dye is used in combination with the above titanocene compound, it is called a photoinitiating system. Preferred sensitizing dyes have an absorption characteristic of 5 in the photosensitive layer.
It shows a larger absorbance at 400 nm than at 00 nm. Furthermore, a preferred sensitizing dye has a spectral sensitivity characteristic of a wavelength shorter than 450 nm, more preferably,
Wavelength shorter than 430 nm and longer than 300 nm,
More preferably, it has a maximum photosensitive wavelength at a wavelength longer than 350 nm. The sensitizing dye of the present invention can be used without limitation as long as it satisfies these characteristics.

As sensitizing dyes having such characteristics,
For example, merocyanine dyes represented by the following general formula (1), styryl dyes represented by the following general formula (2), benzopyrans represented by the following general formula (3), coumarins, and the following general formula (4) And anthracenes represented by the following general formula (5).

[0054]

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(Wherein, A represents an S atom or NR ₁ , R ₁ represents a monovalent nonmetallic atomic group, and Y represents a basic nucleus of a dye in cooperation with adjacent A and an adjacent carbon atom. And X ₁ and X ₂ are each independently a monovalent non-metallic atomic group, and X ₁ and X ₂ may combine with each other to form an acidic nucleus of the dye. .)

[0056]

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(Wherein X ₁ and X ₂ have the same meanings as those in formula (1), and R ₂ to R ₆ are each independently a monovalent nonmetallic atomic group, preferably R ₂ To R ₆ , at least one of which is a Hammett's substituent constant having a negative electron donating substituent)

[0058]

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(Wherein ＝ Y represents a carbonyl group, a thiocarbonyl group, an imino group or an alkylidene group represented by the above partial structural formula (1), and X ₁ and X ₂ have the same meanings as in the general formula (1). And R ₇ to R ₁₂ each independently represent a monovalent non-metallic atomic group.

[0060]

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(In the formula, Ar ₁ represents an aromatic group or a heteroaromatic group which may have a substituent, and R ₁₃ each independently represents a monovalent nonmetallic atomic group. More preferred R
₁₃ is an aromatic group or a heteroaromatic group, and Ar ₁
And R ₁₃ may combine with each other to form a ring. )

[0062]

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(Wherein X ₃ , X ₄ , R ₁₄ to R ₂₁ each independently represents a monovalent nonmetallic atomic group, and is more preferably
X ₃ and X ₄ are Hammett's substituent constants each having a negative electron donating group.

Preferred examples of the monovalent nonmetallic atomic group represented by X ₁ to X ₄ and R ₁ to R ₂₁ in the general formulas (1) to (5) include a hydrogen atom and an alkyl group (for example, Methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl,
Decyl group, undecyl group, dodecyl group, tridecyl group,
Hexadecyl group, octadecyl group, eicosyl group, isopropyl group, isobutyl group, s-butyl group, t-butyl group, isopentyl group, neopentyl group, 1-methylbutyl group, isohexyl group, 2-ethylhexyl group, 2-methylhexyl group, Cyclohexyl group, cyclopentyl group, 2-norbornyl group, chloromethyl group, bromomethyl group, 2-chloroethyl group, trifluoromethyl group, methoxymethyl group, methoxyethoxyethyl group, allyloxymethyl group, phenoxymethyl group, methylthiomethyl group, Tolylthiomethyl group, ethylaminoethyl group, diethylaminopropyl group, morpholinopropyl group, acetyloxymethyl group, benzoyloxymethyl group, N-cyclohexylcarbamoyloxyethyl group, N-phenylcarbamoyloxy Ethyl group, acetylaminoethyl group, N-methylbenzoylaminopropyl group, 2-oxoethyl group, 2-oxopropyl group, carboxypropyl group, methoxycarbonylethyl group, allyloxycarbonylbutyl group, chlorophenoxycarbonylmethyl group, carbamoylmethyl Group, N-methylcarbamoylethyl group, N, N-dipropylcarbamoylmethyl group, N
-(Methoxyphenyl) carbamoylethyl group, N-methyl-N- (sulfophenyl) carbamoylmethyl group,
Sulfobutyl group, sulfonatobutyl group, sulfamoylbutyl group, N-ethylsulfamoylmethyl group, N, N
-Dipropylsulfamoylpropyl group, N-tolylsulfamoylpropyl group, N-methyl-N- (phosphonophenyl) sulfamoyloctyl group, phosphonobutyl group, phosphonatohexyl group, diethylphosphonobutyl group, Diphenylphosphonopropyl group, methylphosphonobutyl group, methylphosphonatobutyl group, tolylphosphonohexyl group, tolylphosphonatohexyl group, phosphonooxypropyl group, phosphonatoxybutyl group, benzyl group, phenethyl group, α- Methylbenzyl group, 1-methyl-1-phenylethyl group, p-methylbenzyl group, cinnamyl group, allyl group, 1-propenylmethyl group, 2-butenyl group, 2-methylallyl group, 2
-Methylpropenylmethyl group, 2-propynyl group, 2-
Butynyl group, 3-butynyl group, etc.), aryl group (for example, phenyl group, biphenyl group, naphthyl group, tolyl group, xylyl group, mesityl group, cumenyl group, chlorophenyl group, bromophenyl group, chloromethylphenyl group,
Hydroxyphenyl group, methoxyphenyl group, ethoxyphenyl group, phenoxyphenyl group, acetoxyphenyl group, benzoyloxyphenyl group, methylthiophenyl group, phenylthiophenyl group, methylaminophenyl group, dimethylaminophenyl group, acetylaminophenyl group, Carboxyphenyl group, methoxycarbonylphenyl group, ethoxyphenylcarbonyl group, phenoxycarbonylphenyl group, N-phenylcarbamoylphenyl group, phenyl group, cyanophenyl group, sulfophenyl group, sulfonatophenyl group, phosphonophenyl group, phosphonatophenyl A heteroaryl group (eg, thiophene, thiazulene, furan, pyran, isobenzofuran, chromene, xanthene, phenoxazine,
Pyrrole, pyrazole, isothiazole, isoxazole, pyrazine, pyrimidine, pyridazine, indolizine, isoindolizine, indoyl, indazole,
Purine, quinolidine, isoquinoline, phthalazine, naphthyridine, quinazoline, sinoline, pteridine, carbazole, carboline, phenanthrin, acridine, perimidine, phenanthroline, phthalazine, phenazazine, phenoxazine, phenoxazine, phenoxazine, alkenyl group (for example, vinyl group) , 1-propenyl group, 1-butenyl group, cinnamyl group, 2-chloro-1-
Ethenyl group, etc.), alkynyl group (eg, ethynyl group, 1-propynyl group, 1-butynyl group, trimethylsilylethynyl group, etc.), halogen atom (-F, -Br,-
Cl, -I), hydroxyl group, alkoxy group, aryloxy group, mercapto group, alkylthio group, arylthio group, alkyldithio group, aryldithio group, amino group, N-alkylamino group, N, N-dialkylamino group, N -Arylamino group, N, N-diarylamino group, N-alkyl-N-arylamino group, acyloxy group, carbamoyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N,
N-dialkylcarbamoyloxy group, N, N-diarylcarbamoyloxy group, N-alkyl-N-arylcarbamoyloxy group, alkylsulfoxy group, arylsulfoxy group, acylthio group, acylamino group, N
-Alkylacylamino group, N-arylacylamino group, ureido group, N'-alkylureido group, N ',
N'-dialkylureido group, N'-arylureido group, N ', N'-diarylureido group, N'-alkyl-N'-arylureido group, N-alkylureido group, N-arylureido group, N' -Alkyl-N-alkylureido, N'-alkyl-N-arylureido, N ', N'-dialkyl-N-alkylureido, N', N'-dialkyl-N-arylureido, N ' -Aryl-N-alkylureido group, N'-
Aryl-N-arylureido group, N ', N'-diaryl-N-alkylureido group, N', N'-diaryl-N-arylureido group, N'-alkyl-N '
-Aryl-N-alkylureido group, N'-alkyl-N'-aryl-N-arylureido group, alkoxycarbonylamino group, aryloxycarbonylamino group, N-alkyl-N-alkoxycarbonylamino group, N-alkyl -N-aryloxycarbonylamino group, N-aryl-N-alkoxycarbonylamino group, N-aryl-N-aryloxycarbonylamino group, formyl group, acyl group, carboxyl group, alkoxycarbonyl group, aryloxycarbonyl group, Carbamoyl group, N-alkylcarbamoyl group, N, N-dialkylcarbamoyl group, N-arylcarbamoyl group,
N, N-diarylcarbamoyl group, N-alkyl-N
-An arylcarbamoyl group, an alkylsulfinyl group,
An arylsulfinyl group, an alkylsulfonyl group, an arylsulfonyl group, a sulfo group (-SO ₃ H) and its conjugated base group (hereinafter referred to as sulfonato group), alkoxy sulfonyl group, aryloxy sulfonyl group, sulfinamoyl group, N- Arukirusu Rufinamoyl group, N, N-dialkylsulfinamoyl group, N-arylsulfinamoyl group, N, N-diarylsulfinamoyl group, N
-Alkyl-N-arylsulfinamoyl group, sulfamoyl group, N-alkylsulfamoyl group, N, N-
Dialkylsulfamoyl group, N-arylsulfamoyl group, N, N-diarylsulfamoyl group, N-alkyl-N-arylsulfamoyl group, phosphono group (—PO ₃ H ₂ ) and its conjugate base group (Hereinafter, referred to as a phosphonate group), a dialkylphosphono group (—PO ₃ (alky
l) ₂ ), a diarylphosphono group (—PO ₃ (aryl) ₂ ),
An alkylarylphosphono group (—PO ₃ (alkyl) (ary
l)), monoalkyl phosphono group (-PO ₃ H (alkyl))
And its conjugated base group (hereinafter referred to as alkylphosphonate group), monoarylphosphono group (-PO ₃ H (ary
l)) and its conjugate base group (hereinafter referred to as arylphosphonate group), phosphonooxy group (-OPO ₃ H ₂ ) and its conjugate base group (hereinafter referred to as phosphonatoxy group), dialkylphosphonoxy Group (-OPO ₃ (alky
l) ₂ ), a diarylphosphonooxy group (—OPO ₃ (ary
l) ₂ ), an alkylarylphosphonoxy group (-OP
O ₃ (alkyl) (aryl)), monoalkylphosphonooxy group (—OPO ₃ H (alkyl)) and its conjugate base group (hereinafter referred to as alkylphosphonatooxy group), monoarylphosphonooxy group (− OPO ₃ H (aryl)) and its conjugated base group (hereinafter referred to as arylphosphonatooxy group), cyano group, nitro group and the like. Among the above substituents, hydrogen atom, alkyl group, aryl group , A halogen atom, an alkoxy group and an acyl group are particularly preferred.

In the general formula (1), the basic nucleus of the dye formed together with A adjacent to Y and adjacent carbon atoms in the general formula (1) is a 5-, 6-, or 7-membered nitrogen-containing or sulfur-containing heterocyclic ring. And a 5- or 6-membered heterocyclic ring is preferred.

Examples of the nitrogen-containing heterocyclic ring include, for example, LGBr
ooker et al., J. Am. Chem. Soc., 73, 5326-5358.
(1951) and any of the merocyanine dyes described in the references which are known as constituting the basic nucleus can be suitably used. As a specific example,
Thiazoles (for example, thiazole, 4-methylthiazole, 4-phenylthiazole, 5-methylthiazole, 5-phenylthiazole, 4,5-dimethylthiazole, 4,5-diphenylthiazole, 4,5-di (p
-Methoxyphenylthiazole), 4- (2-thienyl) thiazole, etc.), benzothiazoles (for example,
Benzothiazole, 4-chlorobenzothiazole, 5-
Chlorobenzothiazole, 6-chlorobenzothiazole, 7-chlorobenzothiazole, 4-methylbenzothiazole, 5-methylbenzothiazole, 6-methylbenzothiazole, 5-bromobenzothiazole, 4-phenylbenzothiazole, 5-phenylbenzo Thiazole, 4-methoxybenzothiazole, 5-methoxybenzothiazole, 6-methoxybenzothiazole, 5-iodobenzothiazole, 6-iodobenzothiazole,
4-ethoxybenzothiazole, 5-ethoxybenzothiazole, tetrahydrobenzothiazole, 5,6-dimethoxybenzothiazole, 5,6-dioxymethylenebenzothiazole, 5-hydroxybenzothiazole,
6-hydroxybenzothiazole, 6-dimethylaminobenzothiazole, 5-ethoxycarbonylbenzothiazole, etc.), naphthothiazoles (for example, naphtho [1,2] thiazole, naphtho [2,1] thiazole,
5-methoxynaphtho [2,1] thiazole, 5-ethoxynaphtho [2,1] thiazole, 8-methoxynaphtho [1,2] thiazole, 7-methoxynaphtho [1,2]
Thiazole, etc.), thianaphtheno-7 ′, 6 ′, 4,5-
Thiazoles (for example, 4'-methoxythianaphtheno-
7 ', 6', 4,5-thiazole and the like, oxazoles (for example, 4-methyloxazole, 5-methyloxazole, 4-phenyloxazole, 4,5-diphenyloxazole, 4-ethyloxazole, 4,5- Dimethyl oxazole, 5-phenyl oxazole, etc.),
Benzoxazoles (benzoxazole, 5-chlorobenzoxazole, 5-methylbenzoxazole, 5-phenylbenzoxazole, 6-methylbenzoxazole, 5,6-dimethylbenzoxazole, 4,6-dimethylbenzoxazole, 6-methoxy Benzoxazole, 5-methoxybenzoxazole, 4-ethoxybenzoxazole, 5-chlorobenzoxazole, 6-methoxybenzoxazole, 5
-Hydroxybenzoxazole, 6-hydroxybenzoxazole, etc.), naphthoxazoles (for example,
Naphtho [1,2] oxazole, naphtho [2,1] oxazole and the like, selenazoles (for example, 4-methyl selenazole, 4-phenyl selenazole and the like), and benzo selenazoles (for example, benzo selenazole, 5- Chlorobenzo selenazole, 5-methoxy benzo selenazole, 5-hydroxy benzo selenazole, tetrahydro benzo selenazole, etc., naphtho selenazoles (for example, naphtho [1,2] selenazole, naphtho [2,1]
Selenazole, etc.), thiazolines (eg, thiazoline, 4-methylthiazoline, etc.), 2-quinolines (eg, quinoline, 3-methylquinoline, 5-methylquinoline, 7-methylquinoline, 8-methylquinoline, 6-chloro) Quinoline, 8-chloroquinoline, 6-methoxyquinoline, 6-ethoxyquinoline, 6-hydroxyquinoline, 8-hydroxyquinoline and the like, 4-quinolines (for example, quinoline, 6-methoxyquinoline, 7-methylquinoline, 8-methylquinoline) Methylquinoline, etc.), 1-isoquinolines (eg, isoquinoline, 3,4-dihydroisoquinoline, etc.), 3-isoquinolines (eg, isoquinoline, etc.), benzimidazoles (eg, 1,3-diethylbenzimidazole, 1 -Ethyl-3-phenylbenzimidazole, etc.), , 3-dialkyl indolenine compound (such as 3,3-dimethyl-indolenine, 3,3,
Examples thereof include 5, -trimethylindolenine, 3,3,7, -trimethylindolenine, and the like, 2-pyridines (for example, pyridine, 5-methylpyridine, and the like), and 4-pyridine (for example, pyridine and the like). it can.

Examples of the sulfur-containing heterocyclic ring include, for example, a dithiol partial structure in dyes described in JP-A-3-296759. Specific examples include benzodithiols (e.g., benzodithiol,
5-t-butylbenzodithiol, 5-methylbenzodithiol, etc.), naphthodithiols (eg, naphtho [1,2] dithiol, naphtho [2,1] dithiol, etc.), dithiols (eg, 4,5-dimethyl) Dithiols, 4-phenyldithiols, 4-methoxycarbonyldithiols, 4,5-dimethoxycarbonylbenzodithiols, 4,5-ditrifluoromethyldithiol, 4,5-dicyanodithiol, 4-methoxycarbonylmethyldithiol, -Carboxymethyldithiol).

In the above description of the heterocyclic ring, for convenience, the name of the heterocyclic parent skeleton is conventionally used. However, when the basic skeleton partial structure of the sensitizing dye is used, for example, a benzothiazole skeleton is used. In the case of 3-substituted-2 (3H) -benzothia
Like the zolylidene group, it is introduced in the form of an alkylidene-type substituent with one less degree of unsaturation.

The following are more specific examples of the sensitizing dyes represented by formulas (1) to (5), but the sensitizing dyes usable in the present invention are not limited to these. Absent.

[0070]

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The sensitizing dye of the present invention can be further subjected to various chemical modifications for improving the characteristics of the photosensitive layer. For example, the sensitizing dye and the above-mentioned addition polymerizable compound structure (for example, acryloyl group or methacryloyl group) are bonded by a covalent bond, an ionic bond, a hydrogen bond, or the like, so as to increase the strength of the exposed film, Unwanted precipitation of the dye from the subsequent film can be suppressed. Further, the sensitizing dye and the above-mentioned titanocene compound and other radical generating parts (for example, reductively decomposable sites such as alkyl halide, onium, peroxide, biimidazole, onium, biimidazole, etc., borate, amine, trimethylsilylmethyl) Oxidatively cleavable sites such as carboxymethyl, carbonyl, and imine), thereby significantly increasing the photosensitivity, particularly in the case where the concentration of the photoinitiating system is low. Further, a preferred mode of use of the photosensitive layer is (alkali)
For the purpose of enhancing the suitability for processing in an aqueous developing solution, introduction of a hydrophilic site (a carboxyl group and its ester, a sulfonic acid group and its ester, an acid group such as an ethylene oxide group or a polar group) is effective. Particularly, the ester-type hydrophilic group has a relatively hydrophobic structure in the photosensitive layer and thus has excellent compatibility, and in a developer, generates an acid group by hydrolysis to increase the hydrophilicity. Having. In addition, for example, a substituent can be appropriately introduced for improving compatibility in the photosensitive layer and suppressing crystal precipitation.
For example, in certain types of photosensitive systems, unsaturated bonds such as aryl groups and allyl groups may be very effective in improving compatibility. By introducing an obstacle, crystal precipitation can be significantly suppressed. Further, by introducing a phosphonic acid group, an epoxy group, a trialkoxysilyl group, or the like, it is possible to improve the adhesion to inorganic substances such as metals and metal oxides. In addition, a method such as polymerization of a sensitizing dye can be used depending on the purpose.

Which structure of these sensitizing dyes is used,
Details of how to use, such as whether to use them alone or in combination of two or more, and the amount of addition, can be appropriately set according to the final performance design of the light-sensitive material. For example, by using two or more sensitizing dyes in combination, the compatibility of the photosensitive lithographic printing plate of the invention with the photosensitive layer can be increased. In selecting a sensitizing dye, the molar extinction coefficient at the emission wavelength of the light source used is an important factor in addition to the photosensitivity. By using a dye with a large molar extinction coefficient, the amount of dye added can be relatively small,
It is economical and advantageous from the viewpoint of the physical properties of the photosensitive layer. The photosensitivity of the photosensitive layer of the photosensitive lithographic printing plate of the present invention, the resolution, and the physical properties of the exposed film are greatly affected by the absorbance at the wavelength of the light source. . For example, the sensitivity is reduced in a low region where the absorbance is 0.1 or less. Also, the resolution becomes low due to the influence of halation. However, for the purpose of curing a thick film having a thickness of, for example, 5 μm or more, such a low absorbance may increase the degree of curing. In a high region where the absorbance is 3 or more, most of the light is absorbed on the surface of the photosensitive layer, and further hardening inside is inhibited. For example, when used as a printing plate, film strength, substrate adhesion Will be inadequate. When used in a relatively thin film thickness, the amount of the sensitizing dye to be added is set so that the absorbance of the photosensitive layer is in the range of 0.1 to 1.5, preferably in the range of 0.25 to 1. Is preferred. This is usually 0.05 to 30 parts by weight, preferably 0.1 to 20 parts by weight, more preferably 0.2 to 20 parts by weight, based on 100 parts by weight of the photosensitive layer component.
The range is from 10 to 10 parts by weight.

[Binder Polymer] It is preferable to further use a binder polymer in the photosensitive layer of the photosensitive lithographic printing plate of the present invention. It is preferable to contain a linear organic high molecular polymer as the binder. Any of such “linear organic high molecular polymers” may be used. Preferably, a water- or weakly alkaline water-soluble or swellable linear organic high molecular polymer that enables water development or weakly alkaline water development is selected. The linear organic high molecular polymer is not only used as a film forming agent for the photosensitive layer,
It is selected and used depending on the use as a developer of water, weak alkaline water or an organic solvent. For example, when a water-soluble organic high molecular polymer is used, water development becomes possible. Examples of such a linear organic high molecular polymer include addition polymers having a carboxylic acid group in a side chain, such as JP-A-59-44615, JP-B-54-34327, JP-B-58-12577, and JP-B-58-12757. 54-25957, JP-A-54-92723,
Those described in JP-A-59-53836 and JP-A-59-71048, that is, methacrylic acid copolymer, acrylic acid copolymer, itaconic acid copolymer, crotonic acid copolymer, maleic acid Copolymers and partially esterified maleic acid copolymers. 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 / Other addition-polymerizable vinyl monomers as needed) copolymer,
It is suitable because it has an excellent balance of film strength, sensitivity and developability.

Further, Japanese Patent Publication No. 7-12004,
JP-A-120041, JP-B-7-120042, JP-B-8-12424, JP-A-63-287944, JP-A-63-287947, JP-A-1-271174,
The urethane-based binder polymer containing an acid group described in Japanese Patent Application No. 10-116232 is very excellent in strength, and therefore is advantageous in terms of printing durability and low exposure suitability.
Also, the binder having an amide group described in JP-A-11-171907 has excellent developability and film strength and is suitable.

Further, as the water-soluble linear organic polymer, polyvinyl pyrrolidone, polyethylene oxide and the like are useful. In order to increase the strength of the cured film, alcohol-soluble nylon, polyether of 2,2-bis- (4-hydroxyphenyl) -propane and epichlorohydrin, and the like are also useful. These linear organic high-molecular polymers can be mixed in any amount in all components of the photosensitive layer. 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 30
~ 85% by weight. Further, a compound having a photopolymerizable ethylenically unsaturated double bond and a linear organic high molecular polymer are:
The weight ratio is preferably in the range of 1/9 to 7/3. In a preferred embodiment, the binder polymer is substantially water-free and soluble in alkali. By doing so, it is possible to use no organic solvent which is environmentally unfavorable or to use a very small amount as the developer.
In such a usage, the acid value (acid content per gram of polymer represented by chemical equivalent number) and molecular weight of the binder polymer are appropriately selected from the viewpoint of image strength and developability. The preferred acid value is 0.4 to 3.0 meq / g, and the preferred molecular weight is in the range of 3,000 to 500,000. More preferably, the acid value is 0.6 to 2.0, and the molecular weight is 10,000 to 300,000. Range.

[Co-sensitizer] The sensitivity of the photosensitive layer of the photosensitive lithographic printing plate of the present invention can be further improved by using a certain additive (hereinafter referred to as a co-sensitizer). Although their mechanism of action is not clear, most are thought to be based on the following chemical processes. That is, the photoreaction initiated by the light absorption of the photoinitiating system described above and various intermediate active species (radicals, peroxides, oxidizing agents, reducing agents, etc.) generated in the course of the subsequent addition polymerization reaction are co-increased. It is presumed that the sensitizer reacts to generate a new active radical. These are largely (a) those that can be reduced to form active radicals, (b) those that can be oxidized to form active radicals, and (c) those that react with less active radicals and are more active radicals. Or acting as a chain transfer agent, but there is often no myth as to which of these compounds each belongs to.

(A) Compound which is reduced to generate an active radical Compound having a carbon-halogen bond: It is considered that the carbon-halogen bond is reductively cleaved to generate an active radical. Specifically, for example, trihalomethyl-s-
Triazines, trihalomethyloxadiazoles and the like can be suitably used. Compound having a nitrogen-nitrogen bond: It is considered that the nitrogen-nitrogen bond is cleaved reductively to generate an active radical. Specifically, hexaarylbiimidazoles and the like are preferably used. Compound having an oxygen-oxygen bond: It is considered that an oxygen-oxygen bond is cleaved reductively to generate an active radical. Specifically, for example, organic peroxides and the like are preferably used. Onium compounds: carbon-hetero bond or oxygen-
It is thought that the nitrogen bond is cleaved to generate an active radical. Specifically, for example, diaryliodonium salts,
Triarylsulfonium salts, N-alkoxypyridinium (azinium) salts and the like are preferably used. Ferrocene, iron arene complexes: Active radicals can be generated reductively.

(B) Compound which is oxidized to generate an active radical Alkyl ate complex: It is considered that a carbon-hetero bond is oxidatively cleaved to generate an active radical. Specifically, for example, triarylalkyl borates are preferably used. Alkylamine compound: It is considered that the CX bond on carbon adjacent to nitrogen is cleaved by oxidation to generate an active radical. X is preferably a hydrogen atom, a carboxyl group, a trimethylsilyl group, a benzyl group, or the like. Specifically, for example, ethanolamines, N-
Examples include phenylglycine, N-trimethylsilylmethylaniline and the like. Sulfur-containing and tin-containing compounds: The above-mentioned amines in which the nitrogen atom is replaced with a sulfur atom or a tin atom can generate an active radical by the same action. Compounds having an SS bond are also known to be sensitized by SS cleavage. α-Substituted methylcarbonyl compound: An active radical can be generated by the cleavage of the carbonyl-α carbon bond by oxidation. In addition, those obtained by converting carbonyl to oxime ether also show the same action. Specifically, 2-alkyl-1- [4- (alkylthio) phenyl] -2-morpholinopronone-1 and, after reacting these with hydroxyamines, N-OH was etherified. Oxime ethers can be given. Sulfinates: Active radicals can be generated reductively. Specific examples include sodium arylsulfinate and the like.

C) Compounds that react with radicals to convert them into highly active radicals or act as chain transfer agents: For example, compounds having SH, PH, SiH, and GeH in the molecule are used. These can generate a radical by donating hydrogen to a low-activity radical species, or can generate a radical by being oxidized and then deprotonated. Specific examples include 2-mercaptobenzimidazoles.

More specific examples of these co-sensitizers are described in, for example, JP-A-9-236913 as additives for the purpose of improving sensitivity. Hereinafter, some of the examples will be exemplified, but the present invention is not limited thereto.

[0082]

Embedded image

These co-sensitizers can be subjected to various chemical modifications to improve the characteristics of the photosensitive layer of the photosensitive lithographic printing plate of the present invention, similarly to the above-mentioned sensitizing dyes. is there. For example, sensitizing dyes and activators, binding with addition polymerizable unsaturated compounds and other parts, introduction of hydrophilic sites,
Methods such as the introduction of a substituent for improving compatibility, suppressing the precipitation of crystals, the introduction of a substituent for improving adhesion, and the polymerization can be used.

These co-sensitizers can be used alone or in combination of two or more. The amount used is 0.0 to 100 parts by weight of the compound having an ethylenically unsaturated double bond.
A suitable range is 5 to 100 parts by weight, preferably 1 to 80 parts by weight, and more preferably 3 to 50 parts by weight.

[Polymerization Inhibitor] In the present invention,
In addition, it is desirable to add a small amount of a thermal polymerization inhibitor to prevent unnecessary thermal polymerization of a compound having a polymerizable ethylenically unsaturated double bond during the production or storage of the photosensitive layer component composition. Suitable thermal polymerization inhibitors include hydroquinone, p-methoxyphenol, di-tert-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis (3-methyl-6-tert-butylphenol) ), 2,2'-methylenebis (4-methyl-6-t-butylphenol), cerium N-nitrosophenylhydroxyamine, and the like. The addition amount of the thermal polymerization inhibitor is preferably about 0.01% to about 5% by weight based on the weight of the whole composition. Further, if necessary, a higher fatty acid derivative such as behenic acid or behenic acid amide is added to prevent polymerization inhibition by oxygen, and drying after coating the photosensitive layer of the photosensitive lithographic printing plate of the present invention. In the process, it may be unevenly distributed on the surface of the photosensitive layer. The amount of the higher fatty acid derivative added is about 0.5% by weight of the total composition.
~ 10% by weight is preferred.

[Colorant] Further, a dye or a pigment may be added for the purpose of coloring the photosensitive layer of the photosensitive lithographic printing plate of the present invention. As a result, it is possible to improve the so-called plate inspection, such as the visibility of the printing plate after plate making and the suitability for an image density measuring device. As a coloring agent, a pigment is particularly preferable because many dyes lower the sensitivity of the photopolymerizable photosensitive layer. Specific examples include pigments such as phthalocyanine pigments, azo pigments, carbon black, and titanium oxide, and dyes such as ethyl violet, crystal violet, azo dyes, anthraquinone dyes, and cyanine dyes. The amount of dyes and pigments added is preferably from about 0.5% to about 5% by weight of the total composition.

[Other Additives] Furthermore, in order to improve the physical properties of the cured film of the photosensitive layer of the photosensitive lithographic printing plate of the present invention, an inorganic filler, other plasticizers, and the ink adhesion on the surface of the photosensitive layer are improved. Known additives such as a sensitizer that can be improved may be added. As the plasticizer, for example, dioctyl phthalate,
There are didodecyl phthalate, triethylene glycol dicaprylate, dimethyl glycol phthalate, tricresyl phosphate, dioctyl adipate, dibutyl sebacate, triacetyl glycerin, etc. It can be added in an amount of 10% by weight or less based on the total weight of the compound and the binder. Further, for the purpose of improving the film strength (printing durability) described later of the photosensitive layer of the photosensitive lithographic printing plate of the present invention, a UV initiator for enhancing the effect of heating and exposure after development,
A thermal crosslinking agent or the like can be added.

In addition, it is possible to provide an additive and an intermediate layer for improving the adhesion between the photosensitive layer of the photosensitive lithographic printing plate of the present invention and the support, and for improving the development removability of the unexposed photosensitive layer. . For example, by adding or undercoating a compound having a relatively strong interaction with the substrate, such as a compound having a diazonium structure or a phosphone compound, the adhesion can be improved and the printing durability can be improved. And, by adding or undercoating a hydrophilic polymer such as polysulfonic acid,
The developability of the non-image area is improved, and the stainability can be improved.

When the photosensitive layer of the photosensitive lithographic printing plate of the present invention is coated on a support described below, the photosensitive layer component composition is coated with
It is used after being dissolved in various organic 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, Ethylene 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, methyl lactic acid Ethyl 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 2 to 50% by weight.

The coating amount of the photosensitive layer on the support mainly affects the sensitivity, developability of the photosensitive layer, and the strength and printing durability of the exposed film, and is desirably appropriately selected according to the application. If the coating amount is too small, the printing durability will be insufficient. On the other hand, if the amount is too large, the sensitivity is lowered, and it takes a long time for exposure, and a longer time is required for the developing process, which is not preferable. The photosensitive lithographic printing plate of the present invention, the coating amount in the range of about 0.1 g / m ² ~ about 10 g / m ² in weight after drying is suitable. More preferably, it is 0.5 to 5 g / m ² .

[Protective Layer] In the photosensitive lithographic printing plate of the present invention, since exposure is usually performed in the air, it is preferable to further provide a protective layer on the photosensitive layer. The protective layer is
The present invention prevents low-molecular compounds such as oxygen and basic substances present in the atmosphere which inhibit an image forming reaction caused by exposure in the photosensitive layer from being mixed into the photosensitive layer, thereby enabling exposure in the atmosphere. Therefore, a desired property of such a protective layer is that the permeability of low molecular compounds such as oxygen is low, and further, the transmission of light used for exposure is not substantially inhibited, and the adhesion to the photosensitive layer is excellent. In addition, it is desirable that it can be easily removed in a developing step after exposure. Such a protective layer has been conventionally devised and described in detail in U.S. Pat. No. 3,458,311 and JP-A-55-49729.

Examples of materials usable for the protective layer include, for example,
Relatively, it is preferable to use a water-soluble polymer compound having excellent crystallinity. Specifically, water-soluble polymers such as polyvinyl alcohol, polyvinylpyrrolidone, acidic celluloses, gelatin, gum arabic, and polyacrylic acid are used. Although it is known, use of polyvinyl alcohol as the main component gives the best results in terms of basic characteristics such as oxygen barrier properties and development removability. The polyvinyl alcohol used for the protective layer may be partially substituted with an ester, an ether or an acetal as long as it contains an unsubstituted vinyl alcohol unit for obtaining necessary oxygen barrier properties and water solubility. Similarly, a part thereof may have another copolymer component. As a specific example of polyvinyl alcohol, 71 to 100% is hydrolyzed, and the molecular weight is 30.
Those having a range of 0 to 2400 can be mentioned. Specifically, Kuraray's PVA-105, PVA-105
-110, PVA-117, PVA-117H, PVA
-120, PVA-124, PVA-124H, PVA
-CS, PVA-CST, PVA-HC, PVA-20
3, PVA-204, PVA-205, PVA-21
0, PVA-217, PVA-220, PVA-22
4, PVA-217EE, PVA-217E, PVA-
220E, PVA-224E, PVA-405, PVA
-420, PVA-613, L-8 and the like.

The components of the protective layer (selection of PVA, use of additives), the amount of coating, etc. are selected in consideration of fogging properties, adhesion, and scratch resistance in addition to oxygen barrier properties and development removal properties. Generally, the higher the hydrolysis rate of the PVA used (the higher the content of unsubstituted vinyl alcohol units in the protective layer) and the thicker the film thickness, the higher the oxygen barrier properties, which is advantageous in terms of sensitivity. However, when the oxygen barrier property is extremely increased, there arises a problem that an unnecessary polymerization reaction occurs at the time of production or raw storage, and that unnecessary fogging and thickening of an image occur at the time of image exposure. Further, the adhesion to the image area and the scratch resistance are also extremely important in handling the plate. That is, when a hydrophilic layer made of a water-soluble polymer is laminated on a lipophilic polymer layer, film peeling due to insufficient adhesive force is apt to occur, and the peeled portion causes defects such as poor film curing due to inhibition of oxygen polymerization. On the other hand, various proposals have been made to improve the adhesiveness between these two layers. For example, U.S. Pat. No. 292,501 and U.S. Pat. No. 44,563 disclose an acrylic emulsion or a water-insoluble vinylpyrrolidone-vinyl acetate copolymer or the like in a hydrophilic polymer mainly composed of polyvinyl alcohol. It is described that sufficient adhesiveness can be obtained by mixing by weight and laminating on a polymer layer. Any of these known techniques can be applied to the protective layer in the photosensitive lithographic printing plate of the invention. Regarding the method of applying such a protective layer,
For example, U.S. Pat. No. 3,458,311;
No. 729.

Further, other functions can be imparted to the protective layer. For example, 350nm to 450n used for exposure
Addition of a coloring agent (such as a water-soluble dye) having excellent light transmittance of m and capable of efficiently absorbing light having a wavelength of 500 nm or more can further enhance the safelight suitability without lowering the sensitivity.

The photosensitive lithographic printing plate of the present invention is usually subjected to image exposure, and then an unexposed portion of the photosensitive layer is removed with a developing solution to obtain an image. Preferred developers for use in preparing a lithographic printing plate from these photosensitive lithographic printing plates include those described in JP-B-57-7427, such as sodium silicate and silicate. Potassium, sodium hydroxide, potassium hydroxide, lithium hydroxide, tribasic sodium phosphate, dibasic sodium phosphate, tribasic ammonium phosphate, dibasic ammonium phosphate, sodium metasilicate, sodium bicarbonate, aqueous ammonia, etc. An aqueous solution of such an inorganic alkali agent or an organic alkali agent such as monoethanolamine or diethanolamine is suitable. The alkaline solution is added so that the concentration of the alkaline solution is 0.1 to 10% by weight, preferably 0.5 to 5% by weight.

Further, such an alkaline aqueous solution includes:
If necessary, a small amount of a surfactant or an organic solvent such as benzyl alcohol, 2-phenoxyethanol or 2-butoxyethanol can be contained. For example, those described in U.S. Pat. Nos. 3,375,171 and 3,615,480 can be mentioned. Further, Japanese Unexamined Patent Publication No.
Nos. 0-26601, 58-54341, Tokubo Sho56
The developers described in JP-A-39464 and JP-A-56-42860 are also excellent.

In addition, in the process of making a lithographic printing plate from the photosensitive lithographic printing plate of the present invention, if necessary, the entire surface may be heated before exposure, during exposure, or between exposure and development. By such heating, an image forming reaction in the photosensitive layer is promoted, and advantages such as improvement in sensitivity and printing durability and stabilization of sensitivity can be brought about. Further, for the purpose of improving image strength and printing durability, it is also effective to post-heat or expose the entire surface of the developed image. Usually, heating before development is preferably performed under mild conditions of 150 ° C. or less. If the temperature is too high, there arises a problem that the non-image portion is covered. Very strong conditions are used for heating after development.
Usually, it is in the range of 200 to 500 ° C. If the temperature is too low, a sufficient image strengthening effect cannot be obtained.

Further, in a system such as CTP, which is a main object of the photosensitive lithographic printing plate of the present invention and performs exposure and development based on digitized image information, a particularly excellent development processing method is possible. It is. That is,
Based on the digitized image information, the most appropriate development and processing conditions are instructed to the control device of the plate material processing apparatus such as an automatic developing machine, and the most appropriate development and processing conditions (developer replenishment amount, development The processing can be performed while appropriately selecting the temperature, development time, post-heating time, finisher conditions, post-exposure conditions, and the like. Thereby, the processing stability can be greatly improved, and the printing performance can be kept constant. For example, Japanese Patent Application Laid-Open No. H11-15144 discloses that the non-image area information A (m
² ) and the plate type information X are stored in the control unit of the automatic processor,
There has been proposed a method of replenishing the replenishment amount according to the following definition according to the information as needed to greatly increase the processing amount of the plate material while minimizing the amount of developer used.

Area replenishment amount (ml) in automatic developing solution = area replenishment rate Rx (ml / m ² ) × area A (m ² )

Here, Rx is the replenishment amount (ml) required when developing 1 m ^{2 of the} plate type X as a non-image area on the entire surface.

The photosensitive lithographic printing plate exposure method of the present invention
Known methods can be used without limitation. Desirable wavelength of the light source is from 350 nm to 450 nm, and specifically, an InGaN-based semiconductor laser is suitable. The exposure mechanism may be any of an internal drum type, an external drum type, a flat bed type, and the like. Further, the photosensitive layer component of the photosensitive lithographic printing plate of the present invention, by using a highly water-soluble,
It can be soluble in neutral water or weak alkaline water,
After the lithographic printing plate having such a configuration is loaded on a printing press, a system such as exposure and development can be performed on the printing press.

As the available laser light source of 350 nm to 450 nm, the following can be used.
Ar ion laser (364n) as a gas laser
m, 351 nm, 10 mW to 1 W), Kr ion laser (356 nm, 351 nm, 10 mW to 1 W), He
-Cd laser (441 nm, 325 nm, 1 mW to 1
00mW), and Nd: YAG (YV
O ₄ ) and SHG crystal × 2 times (355 nm,
5 mW to 1 W), a combination of Cr: LiSAF and SHG crystal (430 nm, 10 mW),

As a semiconductor laser system, a KNbO ₃ ring resonator (430 nm, 30 mW), a combination of a waveguide wavelength conversion element and an AlGaAs or InGaAs semiconductor (380 nm to 450 nm, 5 mW to 100 mW), a waveguide wavelength conversion element and an AlGaInP , AlGaAs semiconductor (300 nm to 350 nm, 5 mW to 1
00mW), AlGaInN (350 nm to 450 n
m, 5 mW to 30 mW) In addition, an N ₂ laser (337 n
m, pulse 0.1 to 10 mJ), XeF (351 nm,
(Pulse 10-250mJ)

Particularly, an AlGaInN semiconductor laser (commercially available InGaN semiconductor laser 400 to 410 n)
m, 5 to 30 mW) is preferable in terms of wavelength characteristics and cost.

As the lithographic printing plate exposure apparatus of the scanning exposure type, there are an inner drum type, an outer drum type, and a flat bed type as an exposure mechanism. can do. Actually, the following exposure apparatus is particularly preferable in relation to the sensitivity of the photosensitive material and the plate making time.

Single-beam exposure apparatus using one gas laser or solid-state laser light source in internal drum system Multi-beam exposure apparatus using many (ten or more) semiconductor lasers in flat bed system Semiconductors in external drum system Multi-beam exposure equipment using many (10 or more) lasers,

In the lithographic printing plate of the laser direct drawing type as described above, the sensitivity of the photosensitive material X (J / cm ² ), the exposure area S (cm ² ) of the photosensitive material, the power q of one laser light source are generally used.
Equation (eq1) holds between (W), the number of lasers n, and the total exposure time t (s).

X · S = n · q · t − (eq1)

I) In the case of the internal drum (single beam) system: Laser rotation speed f (radian / s), sub-scanning length L of photosensitive material
x (cm), resolution Z (dot / cm), total exposure time t
Expression (eq2) generally holds during (s).

F · Z · t = Lx− (eq2)

Ii) In the case of the external drum (multi-beam) system: the drum rotation speed F (radian / s), the sub-scanning length Lx of the photosensitive material
(Cm), resolution Z (dot / cm), total exposure time t
Equation (eq3) generally holds between (s) and the number of beams (n).
Holds.

F · Z · nt · L = Lx− (eq3)

Iii) In the case of the flat head (multi-beam) system The rotation number H (radian / s) of the polygon mirror, the sub-scanning length Lx (cm) of the photosensitive material, the resolution Z (dot / cm), the total exposure time t ( s) and the number of beams (n), the equation (eq4) generally holds.

F · Z · nt · L = Lx− (eq4)

The resolution required for the actual printing plate (256
0 dpi), plate size (A1 / B1, sub-scan length 42 in)
ch), exposure conditions of about 20 sheets / hour and photosensitive characteristics of the photosensitive lithographic printing plate of the present invention (photosensitive wavelength, sensitivity: about 0.1 m
By substituting J / cm ² ) into the above equation, it can be understood that the combination with the semiconductor laser multi-beam exposure method is more preferable in the photosensitive material of the present invention. Furthermore, the combination with an external drum type semiconductor laser multi-beam exposure apparatus is most preferable in terms of operability and cost.

Other exposure light rays for the photosensitive lithographic printing plate according to the present invention include ultrahigh pressure, high pressure, medium pressure,
Low-pressure mercury lamps, chemical lamps, carbon arc lamps,
Xenon lamps, metal halide lamps, various visible and ultraviolet laser lamps, fluorescent lamps, tungsten lamps, sunlight and the like can also be used.

[0117]

Hereinafter, the present invention will be described with reference to Examples.
The present invention is not limited to these examples. After adjusting the aluminum melt composed of the following components, performing molten metal treatment and filtering, an ingot having a thickness of 500 mm and a width of 1200 mm was created by DC casting, and the surface was shaved off by an average 10 mm chamfer, The temperature is maintained at 550 ° C for about 5 hours, and the temperature is 400
° C, the thickness was reduced to 2.7 using a hot rolling mill.
mm rolled plate and heat-treated with a continuous annealing machine for 5 minutes.
After performing at 00 degreeC, it finished to 0.24 mm in thickness by cold rolling. This aluminum plate was used in the following examples of the present invention and comparative examples. The basic components of Al used were the levels shown in Table 1. The percentage in the following examples is
All percentages are by weight unless otherwise noted.

[0118]

[Table 1]

Adjusted as described above, thickness 0.24 m
The treatment was continuously performed using a JIS A 1050 aluminum plate having a width of 1030 mm and a width of 1030 mm. (A) Specific gravity 1.12 using an existing mechanical roughening device
While the suspension of the polishing agent (pumice) and water was supplied to the surface of the aluminum plate as a polishing slurry liquid, the surface was mechanically roughened with a rotating roller-shaped nylon brush.
The average particle size of the abrasive is 40-45 μm and the maximum particle size is 200 μ
m. The nylon brush was made of nylon 6/10, and had a bristle length of 50 mm and a bristle diameter of 0.3 mm. Nylon brushes were made by making holes in a stainless steel cylinder of φ300 mm and densely implanting the hairs. 3 rotating brushes
Used this book. Two support rollers at the bottom of the brush (φ20
0 mm) was 300 mm. The brush roller was pressed until the load of the drive motor for rotating the brush became 7 kW plus the load before pressing the brush roller against the aluminum plate. The rotating direction of the brush is the same as the moving direction of the aluminum plate, and the number of rotation is 20.
It was 0 rpm.

(B) An aluminum plate was prepared with a sodium hydroxide concentration of 2.6 wt%, an aluminum ion concentration of 6.5 wt%,
Etching treatment by spraying was performed at a temperature of 70 ° C., and 13 g / m ^{2 of the} aluminum plate was dissolved. Thereafter, washing with water was performed by spraying. (C) Desmut treatment was performed by spraying with a 1% by weight aqueous solution of nitric acid (containing 0.5% by weight of aluminum ions) at a temperature of 30 ° C., and then washing with water was performed by spraying. As the nitric acid aqueous solution used for the desmutting, a waste liquid from a step of performing electrochemical surface roughening using an alternating current in a nitric acid aqueous solution was used.

(D) Electrochemical surface roughening treatment was performed continuously using an AC voltage of 60 Hz. At this time, the electrolytic solution was a 1 wt% aqueous solution of nitric acid (aluminum ion 0.5 w
t%, ammonium ion 0.007 wt%), and the temperature was 40 ° C. In the AC power supply, the time TP until the current value reaches a peak from zero is 2 msec, and the duty ratio is 1:
1. Using a trapezoidal rectangular wave alternating current, electrochemical surface roughening treatment was performed using a carbon electrode as a counter electrode. Ferrite was used for the auxiliary anode. Current density is 3 at peak current
0 A / dm ² , and the amount of electricity was 255 C / cm ² in total of the amount of electricity when the aluminum plate was an anode. 5% of the current flowing from the power supply was diverted to the auxiliary anode. Thereafter, water washing by spraying was performed.

(E) The aluminum plate was treated with caustic soda concentration 2
When an etching process by spraying is performed at 32 ° C. at 6 wt% and an aluminum ion concentration of 6.5 wt%, an aluminum plate is dissolved at 0.2 g / m ² , and electrochemical surface roughening is performed using a preceding alternating current. The smut component mainly composed of aluminum hydroxide formed was removed, and the edge portion of the generated pit was dissolved to smooth the edge portion.
Then, it was washed with water by spraying. (F) Desmut treatment was performed by spraying with an aqueous solution of 25 wt% sulfuric acid (containing 0.5 wt% of aluminum ions) at a temperature of 60 ° C., followed by washing with water by spraying.

(G) Anodizing apparatus of the existing two-stage power supply electrolytic treatment method (each of the first and second electrolytic unit lengths 6 m, the first power supply unit length 3 m, the second power supply unit length 3 m, and the first and second power supply electrode lengths) 2.4m), the concentration of sulfuric acid in the electrolytic part is 170 g / liter (containing 0.5 wt% of aluminum ions), and the temperature is 3
Anodizing treatment was performed at 8 ° C. Thereafter, washing with water was performed by spraying. At this time, in the anodizing apparatus, the current from the power supply flows to the first power supply electrode provided in the first power supply unit, flows to the plate aluminum through the electrolytic solution, and the plate electrolytic aluminum is supplied to the first electrolytic unit. An oxide film is formed on the surface, and returns to the power supply through the electrolytic electrode provided in the first power supply unit.

On the other hand, the current from the power supply flows to the second power supply electrode provided in the second power supply unit, similarly flows to the plate aluminum through the electrolytic solution, and is applied to the surface of the plate aluminum by the second electrolytic unit. An oxide film is generated, and the amount of electricity supplied from the power supply to the first power supply unit is the same as the amount of electricity supplied from the power supply to the second power supply unit, and the power supply current density on the oxide film surface in the second power supply unit Was about 25 (A / dm ² ). In the second power supply section, power was supplied from the oxide film surface of 1.35 g / m ² . The final oxide film amount is 2.7 g / m
^{Was 2} . The substrate so far is referred to as [A].

In the substrate [A], the substrate prepared by removing the brush polishing in (a) is referred to as [B]. In the substrate [B], the processing temperature in the (g) anodic oxidation treatment is 50 ° C.
The substrate having the power supply current density of 5 (A / dm ² ) is referred to as a substrate [C]. In the substrate [B], (g) the treatment liquid temperature in the anodic oxidation treatment is 10 ° C. and the power supply current density is 4
A substrate having a concentration of 0 (A / dm ² ) and a sulfuric acid concentration of 80 g / liter is referred to as a substrate [D]. In the substrate [B], (g)
A substrate [E] having a treatment liquid temperature of 60 ° C., a power supply current density of 1 (A / dm ² ), and a sulfuric acid concentration of 350 g / liter in the anodic oxidation treatment was used.

On the substrate [B], after anodizing, p
A substrate [F] was immersed in a NaOH aqueous solution of H12 at 40 ° C. for 10 seconds. In the substrate [B], a substrate [G] having (g) a treatment liquid temperature of 50 ° C., a feeding current density of 10 (A / dm ² ), and a sulfuric acid concentration of 300 g / liter was used. In the substrate [B], (g) the treatment liquid temperature in the anodic oxidation treatment is 5 ° C.
Feeding current density 50 (A / dm ² ), sulfuric acid concentration 50 g /
What was 1 liter is referred to as a substrate [H].

(Image Forming Layer) First, S was formed by the following procedure.
A liquid composition (sol solution) of Method G was prepared. The following composition was weighed into a beaker and stirred at 25 ° C. for 20 minutes.

Si (OC ₂ H ₅ ) ₄ 38 g 3-methacryloxypropyltrimethoxysilane 13 g 85% phosphoric acid aqueous solution 12 g Deionized water 15 g Methanol 100 g

The solution was transferred to a three-necked flask, fitted with a reflux condenser, and immersed in the oil bath at room temperature. The contents of the three-necked flask were heated to 50 ° C. in 30 minutes while stirring with a magnetic stirrer. While maintaining the bath temperature at 50 ° C, the reaction was further performed for 1 hour to obtain a liquid composition (sol liquid). This sol solution was applied to a substrate diluted with methanol / ethylene glycol = 20/1 (weight ratio) to 0.5% by weight, and then dried at 100 ° C. for 1 minute. The coating amount at that time was 3.5 mg / m ² . The amount of the Si element was also determined by the fluorescent X-ray analysis method, and this amount was used as the amount of the Si coating.

On the thus treated aluminum plate, the photosensitive composition having the following composition was applied in a dry coating amount of 1.3 g / g.
m ² and dried at 80 ° C. for 2 minutes to form a photosensitive layer.

(Photosensitive composition) Pentaerythritol tetraacrylate 1.5 g Benzyl methacrylate / methacrylic acid copolymer 2.0 g (copolymerization molar ratio 75/25) Sensitizing dye of the following formula 0.07 g of the following formula Titanocene compound 0.03 g Fluorinated nonionic surfactant (F-177P) 0.03 g Thermal polymerization inhibitor (N-nitrosophenylhydroxyl 0.01 g amine aluminum salt) Pigment dispersion having the following composition 2.0 g Methyl ethyl ketone 20 g Propylene Glycol monomethyl ether 20 g

[0132]

Embedded image

(Pigment dispersion composition) 30 g of pigment P-18 represented by the following formula (average particle size: 0.13 μm, transmittance: 400 nm> 500 nm) Allyl methacrylate / methacrylic acid copolymer 20 g (copolymerization ratio: 80/20, Weight average molecular weight 40,000) cyclohexanone 35 g methoxypropyl acetate 115 g

[0134]

Embedded image

(Preparation of Protective Layer) A 3% by weight aqueous solution of polyvinyl alcohol (a saponification degree of 98 mol% and a polymerization degree of 550) was coated on the photosensitive layer so that the dry coating weight was 2 g / m ² . Dry at 100 ° C. for 2 minutes.

For the photosensitive lithographic printing plate obtained as described above, a monochromatic light of 400 nm was used as a light source, and the exposure power was adjusted so that the plate surface exposure energy density was 150 μJ. The exposure was performed like a halftone dot image in 10% increments. After that, the temperature was raised to
Exposure was performed for 2 seconds. The development was performed by immersing in the following developer at 25 ° C. for 30 seconds.

[0137] Potassium (developer) 1K potassium silicate 30g hydroxide _{15g C 12 H 25 -C 6 H} 4 -O-C 6 H 4 -SO 3 Na 3g Water 1000g

Next, gum solution FP- manufactured by Fuji Photo Film Co., Ltd.
2W was diluted twice with water, and the plate was treated according to the usage.
To measure the printing durability, use a diamond 1F-2 made by Mitsubishi Heavy Industries as a printing machine.
And the ink used is Graph G manufactured by Dainippon Ink and Chemicals, Inc.
(N) was used. The printed matter was sampled every 5000th sheet from the start of printing, and printed up to 150,000 sheets.
The number of sheets at which the density of the ink in the solid image portion began to decrease at this time was regarded as printing durability. As an index of halftone dot thickening, halftone dot% on a printed material was calculated from the density of the halftone dot portion using the Murray Davis formula. The results are shown in Table 2 below.

[0139]

[Table 2]

The pore diameter and the pore density were obtained from SEM photographs of the surface of the support, which were observed with a scanning electron microscope S-900 manufactured by Hitachi, Ltd. at an accelerating voltage of 12 kV and at an acceleration voltage of 150,000 times without vapor deposition. Was. The pore diameter is the average value of 50 randomly selected pores, and the pore density is 600 nm.
Calculated from the number of pores in × 600 nm.

As shown in Table 2 above, by setting the pore diameter and the pore density of the anodic oxide film within a certain range,
The dot gain due to scattered light can be suppressed without deteriorating printing durability.

[0142]

As described above, in the photosensitive lithographic printing plate of the present invention, the diameter and the density of the micropores present in the anodic oxide film on the support are defined in a predetermined range, and the photosensitive layer has a thickness of 400 nm. By using a photopolymerizable layer containing a pigment having an optical property whose transmittance at 500 nm is relatively smaller than the transmittance, it is highly sensitive to the transmission wavelength of an inexpensive short-wavelength semiconductor laser and has a bright safelight. It can be handled underneath, and it does not impair the adhesion between the photosensitive layer and the support, so it has excellent printing durability, and it is difficult to deteriorate the halftone dot due to scattered light due to the support, so it reproduces halftone dots It became excellent in nature.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03F 7/09 501 G03F 7/09 501

Claims (1)

[Claims] 1. A photosensitive lithographic printing plate having a photosensitive layer on at least a roughened and anodized aluminum support, wherein the micropores present in the anodic oxide film on the support are pores. Diameter 5-10 nm, pore density 8 × 1
0 ^{15 to} 2 × 10 ¹⁶ particles / m ² , wherein the photosensitive layer comprises (i) at least one titanocene compound, and (ii) at least one titanocene compound.
Addition-polymerizable compound having three ethylenically unsaturated double bonds and (iii) a transmittance greater than 50% at 400 nm.
A photosensitive lithographic printing plate comprising at least one pigment having an optical property with a transmittance of 0 nm being relatively smaller.