JP2001318463A - Negative type original plate of planographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a negative type original plate of a planographic printing plate in which direct recording from digital data of a computer or the like using an IR laser is possible, which has good wear resistance of an image area, good contact of a photosensitive layer to the base and excellent printing resistance. SOLUTION: The negative type original plate is obtained by disposing a photosensitive layer having (A) an IR absorbent, (B) a thermal radical initiator, (C) a radical polymerizable compound and (D) a binder polymer on a base. A polymer having repeating units of formula (I) (where R1 is H or alkyl; R2 is unsubstituted alky; R3 is an aliphatic or aromatic hydrocarbon group having a carboxylic acid group; each of n1-n4 shows the mol% of each repeating unit, n1=5-85, n2=0-60, n3=0-20 and n4=3-60) is contained as the binder polymer (D).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a negative type lithographic printing plate precursor capable of directly making a plate by scanning an infrared laser based on a digital signal from a computer or the like.

[0002]

2. Description of the Related Art Heretofore, as a system for directly making a plate from digital data of a computer, an electrophotographic system, a photopolymerization system for exposing with a laser emitting blue or green light, and a silver salt on a photosensitive resin are known. Laminated ones, silver salt diffusion transfer methods, and the like have been proposed.

However, in the case of using the electrophotographic method, the processes of image formation such as charging, exposure, and development are complicated, and the apparatus is complicated and large. In the case of the photopolymerization system, since a plate material having high sensitivity to blue or green light is used, handling in a bright room becomes difficult. The methods (1) and (2) have drawbacks in that processing such as development becomes complicated because silver salts are used, and silver is contained in the processing waste liquid.

On the other hand, the development of lasers in recent years has been remarkable, and in particular, solid-state lasers and semiconductor lasers that emit infrared light having a wavelength of 760 nm to 1200 nm have become easily available with high output and small size. These lasers are very useful as a recording light source when making a plate directly from digital data of a computer or the like. However, many photosensitive recording materials that are practically useful have a photosensitive wavelength in the visible light range of 760 nm or less, and therefore cannot record images with these infrared lasers. Therefore, a material that can be recorded by an infrared laser is desired.

As an image recording material recordable by such an infrared laser, there is a recording material comprising an onium salt, a phenol resin and a spectral sensitizer described in US Pat. No. 4,708,925. This image recording material is a positive type image recording material utilizing the effect of suppressing dissolution in a developer, which is exhibited by an onium salt and a phenol resin, and is not a negative type as in the present invention. On the other hand, as a negative type image recording material, a recording material comprising an infrared absorber, an acid generator, a resol resin and a novolak resin is disclosed in US Pat.
0,699. However, such a negative-type image recording material requires heat treatment after laser exposure for image formation, and therefore, a negative-type image recording material that does not require heat treatment after exposure is desired. I was For example, JP-B-7-103171 does not require a heat treatment after imagewise exposure, comprising a cyanine dye having a specific structure, an iodonium salt, and an addition-polymerizable compound having an ethylenically unsaturated double bond. Although a recording material is described, this image recording material has a problem that the strength of the formed image portion is low and, for example, when used as a lithographic printing plate, the number of printed matter obtained at the time of printing is small.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to record directly using digital data from a computer or the like by recording using a solid-state laser or a semiconductor laser that emits infrared rays. It is an object of the present invention to provide a negative type lithographic printing plate precursor having excellent abrasion, good adhesion between a photosensitive layer and a support, and excellent printing durability.

[0007]

Means for Solving the Problems The present inventor paid attention to the curing mechanism of the photosensitive layer, and as a result of intensive studies, as a binder polymer used in the photosensitive layer, the use of a polymer having a specific repeating unit as the binder polymer has led to the above object. Have been achieved, and the present invention has been completed. That is, the negative-working lithographic printing plate precursor according to the invention has (A) an infrared absorber, (B) an onium salt, (C) a radically polymerizable compound, and (D) a binder polymer on a support. A photosensitive layer is provided, and a polymer having a repeating unit represented by the following general formula (I) is contained as the binder polymer (D).

[0008]

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In the formula, R ¹ represents a hydrogen atom or an alkyl group which may have a substituent, R ² represents an alkyl group having no substituent, and R ³ represents a carboxylic acid group Represents an aliphatic or aromatic hydrocarbon group. n ¹ , n ² , n
³ and n ⁴ represents the mole% of the repeating units are the following ranges, respectively. n ¹ = 5 to 85, n ² = 0 to 60, n ³ =
0~20, n ⁴ = 3~60.

Although the effect of the present invention is not clear, (D) a polymer having excellent film-forming properties and having adjusted hydrophilicity / hydrophobicity by controlling the component composition to control the permeability of an alkali developing solution is used as the binder polymer. Further, it is presumed that since the polymer has a carboxylic acid group, the developability with alkaline water is excellent, and thus the formation of a recording layer having excellent image forming properties and printing durability is achieved.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
[Polymer Having Repeating Unit Represented by General Formula (I)] In the present invention, at least one polymer having a repeating unit represented by the following general formula (I) is used as the binder polymer (D) in the photosensitive layer. It is characterized by containing.

[0012]

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In the formula, R ¹ represents a hydrogen atom or an alkyl group which may have a substituent, R ² represents an alkyl group having no substituent, and R ³ represents a carboxylic acid group Represents an aliphatic or aromatic hydrocarbon group. n ¹ , n ² , n
³ and n ⁴ represents the mole% of the repeating units are the following ranges, respectively. n ¹ = 5 to 85, n ² = 0 to 60, n ³ =
0~20, n ⁴ = 3~60.

Such a polymer can be synthesized by acetalizing polyvinyl alcohol with an aldehyde and then reacting the remaining hydroxy group with an acid anhydride. Such a polymer is composed of four kinds of repeating units, a vinyl acetal component as a first component, a vinyl alcohol component as a second component, an unsubstituted ester component as a third component, and a fourth component as a fourth component. Is an ester component having a carboxyl group, and each component can have one or more kinds of repeating units.

The vinyl acetal component, which is the first component, is obtained by reacting an aliphatic aldehyde which may have a substituent with a vinyl alcohol component, and when having a substituent, the substituent may be Cl, Examples include a halogen atom such as Br, a carboxyl group, a hydroxyl group, a urethane group, a ureido group, a tertiary amino group, an alkoxy group, a cyano group, a nitro group, an amide group, and an ester group. Specific examples include formaldehyde and acetaldehyde. , Propionaldehyde, butyraldehyde, pentylaldehyde,
Hexylaldehyde, glyoxylic acid, N, N-dimethylformamide di-n-butyl acetal, bromoacetaldehyde, chloroacetaldehyde, 3-hydroxy-n-butyraldehyde, 3- (dimethylamino)-
Examples thereof include 2,2-dimethylpropionaldehyde and cyanoacetaldehyde, but are not limited thereto.

The vinyl alcohol component, which is the second component, has a hydroxyl group in the structure and therefore contributes to the adhesion to a hydrophilic substrate. In the unsubstituted ester component as the third component, the substituent R ² preferably represents an alkyl group having 1 to 10 carbon atoms, and from the viewpoint of developability, a relatively short group such as a methyl group or an ethyl group. Straight chain alkyl groups are preferred. In the ester component having a carboxyl group, which is the fourth component, R ³ has 1 to 3 carbon atoms.
0 aliphatic carboxylic acid groups or aromatic carboxylic acids, which are mainly succinic anhydride, maleic anhydride, phthalic anhydride, trimellitic anhydride, cis-4-cyclohexene-1,2-dicarboxylic anhydride Can be obtained by reacting an acid anhydride such as hexahydrophthalic anhydride with a residual hydroxyl group (—OH) of polyvinyl acetal, but another cyclic acid anhydride may be used as a starting material.

The substituent R ³ may have another group other than the carboxyl group. Examples of such a substituent include a hydroxyl group, a cyano group, a nitro group, a halogen atom such as Cl and Br, or the following groups.

[0018]

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Here, R ⁴ is an alkyl group having 1 to 20 carbon atoms, an aralkyl group or an aryl group, which further has a substituent such as a hydroxyl group, a cyano group, a halogen atom or a nitro group. Is also good. In the binder polymer having the specific repeating unit according to the present invention,
Preferred content of each repeating unit, the first component n ¹ is suitably 5 to 85 mol%, 25 to 70 mol%
Is preferably within the range. If the content of the first component is too low, the film strength tends to decrease, and if the content is too high, the solubility in a coating solvent decreases, and neither is preferable.

The content n ² of the second component is 0 to 60 mol%
Is suitable, and preferably in the range of 10 to 45 mol%. The second component contributes to the adhesion to the support and the hydrophilicity of the binder polymer. If the content of the second component is too small, the contribution to the film strength due to the formation of the crosslinked structure and the hydrophilicity There is a tendency that the contribution to the adhesion to the support is insufficient and the effect of improving the printing durability tends to be reduced. If the amount is too large, the swelling property with respect to water increases, which may affect image reproducibility.

The content n ⁴ of the fourth component is 3 to 60 mol%
And it is preferably 10 to 55 mol%. If the content is too low, the developability with alkaline water is reduced and a residual film is liable to be generated, and the non-image area tends to be stained. All of these are not preferred because they may affect the performance. Third content n ³ components is suitably 0 to 20 mol%, 10 mol%
Is desirably within the range. If the content is too low, the effect of improving the film properties tends to decrease, and if it is too high, the developability tends to decrease.

The weight average molecular weight of the “polymer having a repeating unit represented by the general formula (I)” according to the present invention is suitably in the range of about 5,000 to 400,000, as measured by gel permeation chromatography. Preferably about 5
The number average molecular weight is preferably 1,000 or more, and more preferably 2,000 or more.
２５250,000. The specific polymer is 5 to 95% by weight, preferably 15 to 90% by weight based on the total solid content of the photosensitive layer.
It can be added in a percentage by weight. One kind of this polymer may be used, or two or more kinds having different polymer compositions may be used in combination.

[(D) Binder polymer] The above specific polymer is used as the (D) binder polymer constituting the photosensitive layer of the lithographic printing plate precursor according to the present invention.
(D) All of the binder polymer may be composed of the above-mentioned polymer, but other polymers known as the binder polymer can be used in combination according to the purpose as long as the effects of the present invention are not impaired. As the other binder polymer that can be used in combination, it is necessary to select a polymer having a hydroxyl group, an amide group, a urethane group, or the like in the structure and having compatibility with the specific polymer. When another binder polymer is used in combination, the specific polymer according to the present invention is preferably at least 25% by weight of the total binder polymer, and more preferably in the range of 50 to 100% by weight.

As another polymer that can be used in combination with the binder polymer, a linear organic polymer can be used.
As described above, any “linear organic polymer” may be used as long as it has compatibility with the polymer, as described above. Preferably, a linear organic polymer which is soluble or swellable in water or weakly alkaline water is selected to enable development with water or weakly alkaline water. As such a linear organic polymer, a radical polymer having a carboxylic acid group in a side chain, for example, Japanese Patent Application Laid-Open No.
44615, JP-B-54-34327, JP-B-58
-12577, JP-B-54-25957, JP-A-5
4-92723, JP-A-59-53836, JP-A-59-71048, that is,
Examples include methacrylic acid copolymers, acrylic acid copolymers, itaconic acid copolymers, crotonic acid copolymers, 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, a polymer obtained by adding a cyclic acid anhydride to a polymer having a hydroxyl group is useful.

Among them, (meth) acrylic resins having a benzyl group or an allyl group and a carboxyl group in the side chain are particularly preferred because of their excellent balance of film strength, sensitivity and developability.

In addition, 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.

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.

The weight average molecular weight of the polymer used as a binder in the present invention is preferably 5,000 or more, more preferably 10,000 to 300,000, and the number average molecular weight is preferably 1,000 or more; More preferably, it is in the range of 2000 to 250,000.

These polymers are random polymers,
Any of a block polymer and a graft polymer may be used, but a random polymer is preferable.

The binder polymer used in the present invention contains 20 to 95% by weight based on the total solid content of the coating solution for the photosensitive layer.
Preferably, it is added to the photosensitive layer at a ratio of 30 to 90% by weight. When the addition amount is less than 20% by weight, the strength of the image portion is insufficient when an image is formed. 95% by weight
If the number exceeds, no image is formed.

[(A) Infrared absorbing agent]
Image recording with a laser that emits infrared light. To this end, it is essential to use an infrared absorber. The infrared absorbent has a function of converting the absorbed infrared light into heat. The heat generated at this time decomposes the onium salt to generate radicals. The infrared absorber used in the present invention is a dye or pigment having an absorption maximum at a wavelength of 760 nm to 1200 nm.

As the dye, commercially available dyes and known dyes described in literatures such as “Dye Handbook” (edited by The Society of Synthetic Organic Chemistry, published in 1970) can be used. Specifically, dyes such as azo dyes, metal complex salt azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinone imine dyes, methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, and metal thiolate complexes Is mentioned.

Preferred dyes include, for example, those described in
Cyanine dyes described in JP-A-8-125246, JP-A-59-84356, JP-A-59-202829, JP-A-60-78787, etc .;
No. 96, JP-A-58-181690, JP-A-58-1
No. 94595, etc., methine dyes described in
8-112793, JP-A-58-224793, JP-A-59-48187, JP-A-59-73996,
Naphthoquinone dyes described in JP-A-60-52940 and JP-A-60-63744;
Squarylium dyes described in No. 12792, etc.,
Cyanine dyes described in British Patent 434,875 and the like can be mentioned.

Further, a near-infrared absorption sensitizer described in US Pat. No. 5,156,938 is preferably used, and a substituted arylbenzo (thio) described in US Pat. No. 3,881,924 is also preferable. Pyrylium salt, JP-A-57-142645
No. (U.S. Pat. No. 4,327,169) described in JP-A-58-181051, JP-A-58-220143, JP-A-59-41363, and JP-A-59-41363.
Nos. -84248, 59-84249, 59-14
Nos. 6063 and 59-146061, pyranyl compounds, cyanine dyes described in JP-A-59-216146, pentamethinethiopyrylium salts described in U.S. Pat. No. 4,283,475, and the like. Fairness 5-13
Pyrylium compounds disclosed in JP-A-514 and JP-A-5-19702 are also preferably used.

As another preferred example of the dye, US Pat. No. 4,756,993 discloses a compound represented by the formula (I):
Near-infrared absorbing dyes described as (II) can be mentioned.

Among these dyes, particularly preferred are cyanine dyes, squarylium dyes, pyrylium salts, and nickel thiolate complexes. Further, a cyanine dye is preferable, and a cyanine dye represented by the following general formula (I) is most preferable.

[0037]

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In the general formula (I), X ¹ is a halogen atom,
Or an X ² -L ^1. Here, X ² represents an oxygen atom or a sulfur atom, and L ¹ represents a hydrocarbon group having 1 to 12 carbon atoms. R ¹ and R ² each independently represent a hydrocarbon group having 1 to 12 carbon atoms. From the viewpoint of storage stability of a photosensitive layer coating liquid, R ¹ and R ² are preferably a hydrocarbon group having two or more carbon atoms, further, R ¹ and R ²
And particularly preferably combine with each other to form a 5- or 6-membered ring. Ar ¹ and Ar ² may be the same or different and each represents an aromatic hydrocarbon group which may have a substituent. Preferred aromatic hydrocarbon groups include a benzene ring and a naphthalene ring. Preferred examples of the substituent include a hydrocarbon group having 12 or less carbon atoms, a halogen atom, and an alkoxy group having 12 or less carbon atoms. Y ¹ and Y ² may be the same or different and each have a sulfur atom or 12 carbon atoms.
Represents up to dialkylmethylene groups. R ³ and R ⁴ may be the same or different, and represent a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Preferred substituents include an alkoxy group having 12 or less carbon atoms, a carboxyl group, and a sulfo group.
R ⁵ , R ⁶ , R ⁷ and R ⁸ may be the same or different and each represent a hydrogen atom or a hydrocarbon group having 12 or less carbon atoms. From the viewpoint of availability of raw materials, a hydrogen atom is preferable. Z ^1- represents a counter anion. However,
When any of R ^{1 to} R ⁸ is substituted with a sulfo group, Z ^1- is not required. Preferred Z ¹⁻ is a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, and a sulfonate ion, from the storage stability of the photosensitive layer coating solution, and particularly preferably, a perchlorate ion. Hexafluorophosphate ion and arylsulfonate ion.

In the present invention, specific examples of the cyanine dye represented by formula (I) ([I
R-1] to [IR-12]) are shown below, but the present invention is not limited thereto.

[0040]

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[0041]

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[0042]

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The pigment used in the present invention includes:
Commercial Pigment and Color Index (CI) Handbook,
"Latest Pigment Handbook" (edited by Japan Pigment Technical Association, 1977), "Latest Pigment Application Technology" (CMC Publishing, 1986), "Printing Ink Technology" CMC Publishing, 1984)
Can be used.

The pigments include black pigment, yellow pigment, orange pigment, brown pigment, red pigment, purple pigment,
Blue pigment, green pigment, fluorescent pigment, metal powder pigment, etc.
Polymer-bound dyes. Specifically, insoluble azo pigments, azo lake pigments, condensation azo pigments, chelate azo pigments, phthalocyanine pigments, anthraquinone pigments,
Perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments, quinophthalone pigments, dyeing lake pigments,
Azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black and the like can be used.
Preferred among these pigments is carbon black.

These pigments may be used without being subjected to a surface treatment, or may be used after being subjected to a surface treatment. Examples of the surface treatment include a method of surface coating a resin or wax, a method of attaching a surfactant, and a method of bonding a reactive substance (eg, a silane coupling agent, an epoxy compound, a polyisocyanate, etc.) to the pigment surface. Can be considered. The above surface treatment methods are described in "Properties and Applications of Metallic Soap" (Koshobo),
It is described in "Printing Ink Technology" (CMC Publishing, 1984) and "Latest Pigment Application Technology" (CMC Publishing, 1986).

The particle size of the pigment is preferably in the range of 0.01 μm to 10 μm, more preferably in the range of 0.05 μm to 1 μm, and particularly preferably in the range of 0.1 μm to 1 μm.
Is preferably within the range. Pigment particle size 0.01μ
If it is less than m, the dispersion is not preferred in terms of stability in the coating solution of the image-sensitive layer.

As a method for dispersing the pigment, a known dispersion technique used in the production of ink or toner can be used. Examples of the disperser include an ultrasonic disperser, a sand mill, an attritor, a pearl mill, a super mill, a ball mill, an impeller, a disperser, a KD mill, a colloid mill, a dynatron, a three-roll mill, and a pressure kneader. For details, refer to “Latest Pigment Application Technology” (CMC Publishing, 1
986).

These infrared absorbers may be added to the same layer as other components, or may be added to another layer provided separately. However, when the negative type lithographic printing plate precursor is prepared, It is preferable to add the photosensitive layer so that the absorbance at the maximum absorption wavelength in the wavelength range of 760 nm to 1200 nm is in the range of 0.1 to 3 by reflection measurement. The absorbance of the photosensitive layer can be adjusted by the amount of the infrared absorber added to the photosensitive layer and the thickness of the photosensitive layer. The measurement of the absorbance can be performed by a conventional method. As a measuring method, for example, on a reflective support such as aluminum, a coating layer after drying is formed to a recording layer having a thickness appropriately determined in a range necessary for a lithographic printing plate, and the reflection density is measured by an optical densitometer. And a method of measuring with a spectrophotometer by a reflection method using an integrating sphere.

[(B) Thermal Radical Initiator] The thermal radical initiator is used in combination with the infrared absorbent (A), and generates a radical by irradiating an infrared laser with light or heat or both energies. Refers to a compound.
As the thermal radical initiator, known photopolymerization initiators, thermal polymerization initiators and the like can be selected and used, for example,
Examples thereof include an onium salt, a triazine compound having a trihalomethyl group, a peroxide, an azo-based polymerization initiator, an azide compound, and quinonediazide. Of these, an onium salt is preferable because of its high sensitivity. The onium salt that can be suitably used as a thermal radical initiator in the present invention will be described. Onium salts suitably used are iodonium salts, diazonium salts and sulfonium salts. Onium salts suitably used in the present invention are onium salts represented by the following general formulas (III) to (V).

[0050]

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In the formula (III), Ar ¹¹ and Ar ¹² each independently represent an aryl group having 20 or less carbon atoms which may have a substituent. When the aryl group has a substituent, preferred substituents include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, or a 12 or less carbon atom. Aryloxy groups. Z ^11- represents a counter ion selected from the group consisting of a halogen ion, a perchlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, and a sulfonate ion, and is preferably a perchlorate ion or a hexafluorophosphate. And arylsulfonate ions. In the formula (IV), Ar ²¹ represents an aryl group having 20 or less carbon atoms which may have a substituent. Preferred substituents include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, an alkoxy group having 12 or less carbon atoms, an aryloxy group having 12 or less carbon atoms,
Examples thereof include an alkylamino group having 12 or less carbon atoms, a dialkylamino group having 12 or less carbon atoms, an arylamino group having 12 or less carbon atoms, and a diarylamino group having 12 or less carbon atoms. Z ^{21 -} represents a counter ion of the same meaning as Z ^11-. In the formula (V), R ³¹ , R ³² and R
³³ is the same or different and represents a hydrocarbon group having 20 or less carbon atoms which may have a substituent. Preferred substituents include a halogen atom, a nitro group, an alkyl group having 12 or less carbon atoms, and a 1-carbon atom.
Examples include an alkoxy group having 2 or less or an aryloxy group having 12 or less carbon atoms. Z ^31- represents a counter ion having the same ^meaning as Z ^11- .

In the present invention, an onium salt ([OI-1]) represented by the general formula (III) which can be suitably used:
To [OI-10]), onium salts represented by the general formula (IV) ([ON-1] to [ON-5]), and the general formula (V)
Onium salts represented by ([OS-1] to [OS-5])
Specific examples are described below.

[0053]

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[0054]

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[0055]

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[0056]

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The thermal radical initiator used in the present invention preferably has a maximum absorption wavelength of 400 nm or less, more preferably 360 nm or less. By setting the absorption wavelength in the ultraviolet region, the lithographic printing plate precursor can be handled under a white light.

These thermal radical initiators are used in an amount of 0.1 to 50% by weight, preferably 0.5 to 30% by weight, particularly preferably 1 to 20% by weight, based on the total solid content of the coating solution for the photosensitive layer. It can be added to the photosensitive layer coating solution. If the amount is less than 0.1% by weight, the sensitivity is lowered, and
If the amount exceeds the weight percentage, stains occur in the non-image area during printing. One of these thermal radical initiators may be used alone, or two or more thereof may be used in combination.

[(C) Radical polymerizable compound] The radical polymerizable compound used in the present invention is a radical polymerizable compound having at least one ethylenically unsaturated double bond, and has a terminal ethylenically unsaturated bond. At least one
, Preferably two or more compounds. Such compounds are widely known in the industrial field, and they can be used in the invention without any particular limitation. These have chemical forms such as, for example, monomers, prepolymers, ie, dimers, trimers and oligomers, or mixtures thereof and copolymers thereof. Examples of monomers and copolymers thereof include unsaturated carboxylic acids (eg, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.) and esters and amides thereof, and are preferred. As the ester, an ester of an unsaturated carboxylic acid and an aliphatic polyhydric alcohol compound and an amide of an unsaturated carboxylic acid and an aliphatic polyamine compound are 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. Further, an addition reaction product of an unsaturated carboxylic acid ester or amide having an electrophilic substituent such as an isocyanate group or an epoxy group with a monofunctional or polyfunctional alcohol, amine or thiol, and further, halogen A substitution reaction product of an unsaturated carboxylic acid ester or amide having a leaving group such as a group or a tosyloxy group with a monofunctional or polyfunctional alcohol, amine or thiol is also suitable.
As another example, it is also possible to use a group of compounds in which the above unsaturated carboxylic acid is replaced with unsaturated phosphonic acid, styrene or the like.

Specific examples of the radical polymerizable compound which is an ester of an aliphatic polyhydric alcohol compound and an unsaturated carboxylic acid include acrylates such as ethylene glycol diacrylate, triethylene glycol diacrylate, and 1,3-butane. Diol diacrylate, tetramethylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate, , 4-cyclohexanediol diacrylate, tetraethylene glycol diacrylate, pentaerythritol diacrylate, penta Risuri toll triacrylate,
Pentaerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate,
Examples include sorbitol tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, and polyester acrylate oligomer.

Examples of the 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.

Examples of 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.

The maleic acid ester includes ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, sorbitol tetramaleate and the like.

Examples of other esters include aliphatic alcohol esters described in JP-B-46-27926, JP-B-51-47334, JP-A-57-196231, JP-A-59-5240 and JP-A-59-5240. 59-524
1, 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 preferably used.

Specific examples of amide monomers 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 preferred amide-based monomers include those having a cyclohexylene structure described in JP-B-54-21726.

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

Formula (VI) CH ₂ ＣC (R ⁴¹ ) COOCH ₂ CH (R ⁴² ) OH (where R ⁴¹ and R ⁴² represent H or CH ₃ )

Further, urethane acrylates described in JP-A-51-37193, JP-B-2-32293, JP-B-2-16765, and JP-B-58-167.
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, radical polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277563, JP-A-63-260909 and JP-A-1-105238 can be used. good.

As another example, see JP-A-48-641.
No. 83, JP-B-49-43191, JP-B-52-30
No. 490, 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.

With respect to these radically polymerizable compounds,
Details of the method of use, such as what kind of structure is used, whether it is used alone or in combination, and how much is added, can be arbitrarily set in accordance with the final performance design of the recording material. For example, it is selected from the following viewpoints. From the viewpoint of sensitivity, a structure having a large content of unsaturated groups per molecule is preferable, and in many cases, a bifunctional or more functional structure is preferable. In order to increase the strength of the image area, that is, the cured film, a compound having three or more functional groups is preferable, and a compound having a different functional number and a different polymerizable group (for example, an acrylate compound, a methacrylate ester) It is also effective to control both the photosensitivity and the intensity by using a combination of a compound and a styrene compound. Regarding the compounding ratio of the radically polymerizable compound in the photosensitive layer, the larger the ratio, the better the sensitivity. However, if the ratio is too large, undesired phase separation occurs or problems in the production process due to the development of tackiness ( For example,
Problems such as poor transfer caused by transfer or adhesion of the recording layer components) and precipitation from the developing solution. From these viewpoints, the preferred compounding ratio of the radical polymerizable compound is, in many cases, from 5 to 80% by weight, and preferably from 20 to 75% by weight, based on the total solid content of the photosensitive layer. These may be used alone or in combination of two or more.

[Other Components] In the present invention, various compounds other than these may be further added, if necessary.
For example, a dye having a large absorption in the visible light region can be used as a colorant for an image. Specifically, Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BO
S, Oil Blue # 603, Oil Black BY, Oil Black BS, Oil Black T-505 (all manufactured by Orient Chemical Industries, Ltd.), Victoria Pure Blue,
Crystal violet (CI42555), methyl violet (CI42535), ethyl violet,
Rhodamine B (CI145170B), malachite green (CI42000), methylene blue (CI520
15) and the dyes described in JP-A-62-293247. Also, pigments such as phthalocyanine pigments, azo pigments, carbon black, and titanium oxide can be suitably used.

It is preferable to add these colorants since the image area and the non-image area can be easily distinguished after image formation. The addition amount is based on the total solid content of the photosensitive layer coating solution.
The ratio is 0.01 to 10% by weight.

In the present invention, a small amount of a thermal polymerization inhibitor is used to prevent unnecessary thermal polymerization of a compound having a radically polymerizable ethylenically unsaturated double bond during preparation or storage of a photosensitive layer coating solution. It is desirable to add an agent. Hydroquinone, as a suitable thermal polymerization inhibitor,
p-methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4,4'-thiobis (3-methyl-6-t-butylphenol), 2,2'-methylenebis (4 -Methyl-6-t-butylphenol), N-nitroso-N-phenylhydroxylamine aluminum salt 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. If necessary, a higher fatty acid derivative such as behenic acid or behenic acid amide may be added to prevent polymerization inhibition by oxygen, and may be unevenly distributed on the surface of the photosensitive layer in a drying process after coating. . The amount of the higher fatty acid derivative to be added is about 0.1% of the total composition.
1% to about 10% by weight is preferred.

The photosensitive layer coating solution of the present invention may contain a nonionic solvent such as described in JP-A-62-251740 and JP-A-3-208514 in order to broaden the stability of processing under development conditions. Surfactant, JP-A-59
An amphoteric surfactant as described in JP-A-121044 and JP-A-4-13149 can be added.

Specific examples of the nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan triolate, stearic acid monoglyceride, polyoxyethylene nonyl phenyl ether and the like.

Specific examples of the amphoteric surfactant include alkyldi (aminoethyl) glycine, alkylpolyaminoethylglycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine, N-tetradecyl-N , N-betaine type (for example,
(Trade name: Amogen K, manufactured by Dai-ichi Kogyo Co., Ltd.).

The proportion of the above-mentioned nonionic surfactant and amphoteric surfactant in the coating solution for the photosensitive layer is preferably 0.05 to 15% by weight, more preferably 0.1 to 5% by weight.

Further, a plasticizer is added to the coating solution for the photosensitive layer according to the present invention, if necessary, in order to impart flexibility to the coating film. For example, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, and the like are used.

To produce the lithographic printing plate precursor according to the present invention,
Usually, the above-mentioned components necessary for the photosensitive layer coating solution may be dissolved in a solvent and applied on a suitable support. As the solvent used here, ethylene dichloride, cyclohexanone, methyl ethyl ketone, methanol, ethanol, propanol, ethylene glycol monomethyl ether,
1-methoxy-2-propanol, 2-methoxyethyl acetate, 1-methoxy-2-propyl acetate,
Dimethoxyethane, methyl lactate, ethyl lactate, N, N-
Dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethylsulfoxide, sulfolane, γ-butyllactone,
Examples include toluene and water, but are not limited thereto. These solvents are used alone or as a mixture. The concentration of the above components (total solids including additives) in the solvent is preferably 1 to 50% by weight.

The coating amount (solid content) of the photosensitive layer on the support obtained after coating and drying varies depending on the application, but is generally 0.5 to 5.0 g / lithographic printing plate precursor.
m ² is preferred. As a method of applying, various methods can be used. For example, bar coater application, spin coating, spray application, curtain application, dip application,
Examples include air knife application, blade application, roll application, and the like. As the coating amount decreases, the apparent sensitivity increases, but the film characteristics of the photosensitive layer that performs the function of image recording deteriorate.

The photosensitive layer coating liquid according to the present invention may contain a surfactant for improving coating properties, for example, JP-A-62-17
No. 0950 can be added. The preferable addition amount is 0.01 to 1% by weight, more preferably 0.05 to 0.5% by weight, based on the solid content of the material of the entire photosensitive layer.

[Support] In the lithographic printing plate precursor according to the invention, the support on which the photosensitive layer can be applied is a dimensionally stable plate-like material such as paper or plastic (eg, polyethylene, polypropylene). , Polystyrene, etc.)
Paper, metal plate (eg, aluminum, zinc, copper, etc.), plastic film (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene) , Polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), and paper or plastic film on which the above-described metal is laminated or vapor-deposited. Preferred supports include a polyester film or an aluminum plate.

As the support used in the lithographic printing plate precursor according to the invention, it is preferable to use an aluminum plate which is lightweight and has excellent surface treatment properties, workability and corrosion resistance. Aluminum materials used for this purpose include JIS 1050
Material, JIS 1100 material, JIS 1070 material, Al-
Mg-based alloy, Al-Mn-based alloy, Al-Mn-Mg-based alloy, Al-Zr-based alloy. Al-Mg-Si alloys and the like can be mentioned.

As the aluminum plate for the support,
Plate thickness accuracy is ± 10μm over the entire length of the coil
And preferably within ± 6 μm. The difference in the thickness in the width direction is within 6 μm, preferably within 3 μm. Further, the accuracy of the plate width is preferably within ± 1.0 mm, more preferably within ± 0.5 mm. Although the surface roughness of the Al plate is easily affected by the surface roughness of the rolling rolls, the center line surface roughness (Ra) is finally Ra = 0.1 to 1.0.
It is preferable to finish to about 0 μm. If Ra is too large,
When a surface roughening treatment and a photosensitive layer coating for a lithographic printing plate are performed, the original roughness of Al, that is, rough rolling streaks transferred by a rolling roll can be seen from above the photosensitive layer, which is not preferable in appearance. Roughness of Ra = 0.1 μm or less is industrially undesirable because the surface of the rolling roll needs to be finished to an excessively low roughness.

The lithographic printing plate can be prepared by subjecting the aluminum plate to a surface treatment such as a surface roughening treatment and applying a photosensitive layer. In the surface roughening treatment, mechanical surface roughening, chemical surface roughening, and electrochemical surface roughening are performed alone or in combination. Further, it is also preferable to perform an anodic oxidation treatment for securing the surface with difficulty in scratching or a treatment for increasing the hydrophilicity.

The surface treatment of the support will be described below. The surface treatment is carried out by selecting conditions according to the desired characteristics of the lithographic printing plate by a conventional method. Prior to roughening the aluminum plate, if necessary, a degreasing treatment with, for example, a surfactant, an organic solvent, or an alkaline aqueous solution for removing rolling oil on the surface may be performed. In the case of alkali, treatment such as neutralization and removal of smut may be performed with an acidic solution.

Next, in order to improve the adhesion between the support and the photosensitive layer and to impart water retention to the non-image area, a so-called graining treatment is performed to roughen the surface of the support. Specific means of the graining method include sand blast, ball grain, wire grain, brush grain using a nylon brush and an abrasive / water slurry,
There are a mechanical graining method using a honing grain that sprays an abrasive / water slurry onto the surface at high pressure, and a chemical graining method that roughens the surface with an etching agent composed of an alkali, an acid, or a mixture thereof. Not limited to

A plurality of such surface roughening methods may be performed in combination, and the order, the number of repetitions, and the like can be arbitrarily selected. When a plurality of surface roughening treatments are combined, a chemical treatment with an acid or alkali aqueous solution can be performed during that time to make the subsequent surface roughening treatment uniform.

Since smut is formed on the surface of the support obtained by the above-mentioned surface roughening treatment, ie, graining treatment, a treatment such as washing with water or alkali etching is appropriately performed to remove the smut. Is generally preferred. Examples of such processing include, for example,
Examples thereof include a treatment method such as an alkali etching method described in JP-A-8-28123 and a desmutting sulfate method described in JP-A-53-12739.

In the case of the aluminum support used in the present invention, after the pretreatment as described above, the support is usually anodized to improve abrasion resistance, chemical resistance and water retention. To form an oxide film.

As the electrolyte used in the anodic oxidation treatment of the aluminum plate, any electrolyte can be used as long as it forms a porous oxide film.
Phosphoric acid, oxalic acid, chromic acid or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of the electrolyte. Anodizing treatment conditions vary depending on the electrolyte used, and thus cannot be specified unconditionally. However, in general, the concentration of the electrolyte is 1 to 80% solution, the liquid temperature is 5 to 70 ° C., and the current density is 5 to 60 A / dm ^2. It is appropriate that the voltage is in the range of 1 to 100 V and the electrolysis time is in the range of 10 seconds to 5 minutes. The amount of the anodized film is suitably 1.0 g / m ² or more, but more preferably in the range of 2.0 to 6.0 g / m ^2. When the anodic oxide film is less than 1.0 g / m ² , the printing durability is insufficient or the non-image area of the lithographic printing plate is easily damaged, and the ink adheres to the damaged area during printing. "Scratch dirt"
Is more likely to occur. In addition, an alkaline aqueous solution (for example, a caustic soda aqueous solution of several%), an anodizing treatment in a molten salt,
For example, anodic oxidation treatment for forming a nonporous anodic oxide film using an aqueous solution of ammonium borate can be performed.

The aluminum support of the present invention can be treated with an organic acid or a salt thereof after anodic oxidation treatment or used as an undercoat layer for coating a photosensitive layer. Examples of the organic acid or a salt thereof include an organic carboxylic acid, an organic phosphonic acid, an organic sulfonic acid or a salt thereof, and preferably an organic carboxylic acid or a salt thereof.

Further, after the anodic oxidation treatment, treatment with the following compound solution or these compounds can be used as an undercoat layer for coating the photosensitive layer. Suitable compounds include, for example, amino acids such as organic phosphonic acid, organic phosphoric acid, organic phosphinic acid, glycine and β-alanine; aminosulfonic acids such as sulfamic acid and cyclohexylsulfamic acid; 1-aminomethylphosphonic acid; -Dimethylaminoethylphosphonic acid Compounds such as aminophosphonic acid such as ethylenediaminetetramethylenephosphonic acid.

Also, salts of hydrochloric acid, sulfuric acid, nitric acid, sulfonic acid (such as methanesulfonic acid) or oxalic acid with alkali metals, ammonia, lower alkanolamines (such as triethanolamine), lower alkylamines (such as triethylamine) and the like can be used. It can be suitably used.

Polyacrylamide, polyvinyl alcohol, polyvinylpyrrolidone, polyethyleneimine and its mineral salts, poly (meth) acrylic acid and its metal salts, polystyrenesulfonic acid and its metal salts, alkyl (meth) acrylate and 2-acrylamide Water-soluble polymers such as 2-methyl-1-propanesulfonic acid and metal salts thereof, polymers of trialkylammonium methylstyrene styrene and copolymers thereof with (meth) acrylic acid, and polyvinylphosphonic acid can also be suitably used. it can.

Further, soluble starch, carboxymethylcellulose, dextrin, hydroxyethylcellulose, gum arabic, guar gum, sodium alginate, gelatin, glucose, sorbitol and the like can also be preferably used. These compounds may be used alone or in combination of two or more.

In the case of treatment, these compounds are preferably dissolved in water and / or methyl alcohol at a concentration of 0.001 to 10% by weight, particularly 0.01 to 1.0% by weight. The support is immersed in a temperature range of 25 to 95 ° C, preferably 50 to 95 ° C, and the pH is 1 to 13, preferably 2 to 10, 10 seconds to 20 minutes, and preferably 10 seconds to 3 minutes.

When used as an undercoat layer for coating of the photosensitive layer, the same applies to water and / or methyl alcohol.
It is dissolved so as to have a concentration of 1 to 10% by weight, particularly 0.01 to 1.0% by weight, and if necessary, a basic substance such as ammonia, triethylamine, potassium hydroxide or the like, hydrochloric acid, phosphoric acid or the like. Adjust the pH with an acidic substance,
It can also be used in the range of ~ 12. Further, a yellow dye can be added for improving the tone reproducibility of the photosensitive lithographic printing plate. The coating amount of the organic undercoat layer after drying is 2 to
200 mg / m ² is suitable, preferably 5 to 100 mg / m ^2.
mg / m ² . If the above-mentioned coating amount is less than 2 mg / m ² , a sufficient effect for the original purpose such as prevention of stain cannot be obtained. On the other hand, if it exceeds 200 mg / m ² , the printing durability will decrease.

An intermediate layer for improving the adhesion between the support and the photosensitive layer may be provided. To improve adhesion,
Generally, the intermediate layer is made of a diazo resin or a phosphoric acid compound adsorbed on aluminum, for example. The thickness of the intermediate layer is arbitrary, and must be such a thickness that a uniform bond-forming reaction with the upper photosensitive layer can be performed when exposed. Normal,
The dry solid has a good coating ratio of about 1 to 100 mg / m ² ,
5-40 mg / m ² are particularly good. The usage ratio of the diazo resin in the intermediate layer is 30 to 100%, preferably 60 to 100%.

After a known silicate treatment or sealing treatment is performed as required, an acidic aqueous solution treatment and a hydrophilic undercoating disclosed in JP-A-5-278362 are performed to improve the adhesion to the photosensitive layer. And Japanese Patent Application Laid-Open
An organic layer disclosed in JP-A-282637 or JP-A-7-314937 may be provided.

After the above-mentioned treatment or undercoating is applied to the surface of the support, a back coat is provided on the back surface of the support, if necessary. As such a back coat, a coating layer comprising a metal oxide obtained by hydrolysis and polycondensation of an organic polymer compound described in JP-A-5-45885 and an organic or inorganic metal compound described in JP-A-6-35174 is used. It is preferably used. Among these coating layers, Si (OCH ₃ ) ₄ , Si (OC
_{2 H 5) 4, Si (} OC 3 H 7) 4, Si (OC 4 H 9) is easily available and inexpensive alkoxy compounds of silicon such as _4, the coating layer of the obtained therefrom metal oxide in developing solution Excellent and particularly preferred.

The preferred characteristics of the lithographic printing plate support are center line average roughness of 0.10 to 1.2 μm. If it is less than 0.10 μm, the adhesion to the photosensitive layer is reduced,
Significant reduction in printing durability occurs. If it is larger than 1.2 μm, the stain on printing will be deteriorated. Further, the color density of the support is 0.15 to 0.5 as a reflection density value.
65, and when it is whiter than 0.15, the halation at the time of image exposure is too strong and hinders image formation.
When it is darker than 0.65, the image is difficult to see in the plate inspection work after development, and the plate inspection property is extremely poor.

As described above, the lithographic printing plate precursor according to the present invention can be prepared. This lithographic printing plate precursor can be recorded with an infrared laser. Also, thermal recording with an ultraviolet lamp or a thermal head is possible. In the present invention, it is preferable that the image is exposed by a solid-state laser or a semiconductor laser that emits infrared rays having a wavelength of 760 nm to 1200 nm. The output of the laser is preferably 100 mW or more, and in order to shorten the exposure time, it is preferable to use a multi-beam laser device. Further, the exposure time per pixel is preferably within 20 μsec. The energy applied to the recording material is 10 to 300 mJ / cm ²
It is preferred that

After exposure with an infrared laser, the image recording material of the present invention is preferably developed with water or an aqueous alkaline solution.

When an alkaline aqueous solution is used as the developer, a conventionally known alkaline aqueous solution can be used as the developer and replenisher for the image recording material of the present invention. For example,
Sodium silicate, potassium, tribasic sodium, potassium, ammonium, dibasic sodium phosphate, potassium, ammonium, sodium carbonate, potassium, ammonium, sodium bicarbonate, potassium, ammonium, Inorganic alkali salts such as sodium borate, potassium, ammonium, sodium hydroxide, ammonium, potassium and lithium. Also, monomethylamine, dimethylamine,
Trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, ethyleneimine, ethylenediamine, pyridine, etc. Organic alkaline agents are also used. These alkali agents are used alone or in combination of two or more.

Further, in the case of developing using an automatic developing machine, the same solution as the developing solution or an aqueous solution (replenisher) having a higher alkali strength than the developing solution is added to the developing solution so that the developing tank can be maintained for a long time. It is known that a large amount of a lithographic printing plate precursor can be processed without replacing the developer. This replenishment system is also preferably applied in the present invention.

Various surfactants and organic solvents can be added to the developing solution and the replenishing solution, if necessary, for the purpose of accelerating or suppressing the developing property, dispersing the developing residue and improving the ink affinity of the printing plate image area. . Preferred surfactants include anionic, cationic, nonionic and amphoteric surfactants. Preferred organic solvents include benzyl alcohol and the like. It is also preferable to add polyethylene glycol or a derivative thereof, or polypropylene glycol or a derivative thereof. Further, non-reducing sugars such as arabit, sorbit, and mannitol can also be added.

Further, the developing solution and the replenisher may contain, if necessary, an inorganic salt-based reducing agent such as hydroquinone, resorcin, sodium or potassium sulfite or bisulfite, an organic carboxylic acid, an antifoaming agent, hard water Softeners can also be added.

Examples of such a developer containing a surfactant, an organic solvent and a reducing agent include, for example, those described in
Benzyl alcohol described in No. 77401,
A developer composition comprising an anionic surfactant, an alkali agent and water, comprising an aqueous solution containing benzyl alcohol, an anionic surfactant, and a water-soluble sulfite as described in JP-A-53-44202; Developer composition,
Examples thereof include a developer composition containing an organic solvent, an alkali agent, and water having a solubility in water of 10% by weight or less at room temperature described in JP-A-55-155355, which is also suitable for the present invention. Used for

The printing plate developed using the developing solution and the replenisher described above is post-treated with washing water, a rinsing solution containing a surfactant and the like, and a desensitizing solution containing gum arabic and a starch derivative. You. As the post-processing when the image recording material of the present invention is used as a printing plate material, these processings can be used in various combinations.

In recent years, in the plate making / printing industry, automatic developing machines for printing plate materials have been widely used in order to rationalize and standardize plate making operations. This automatic developing machine generally includes a developing section and a post-processing section, and includes a device for transporting a printing plate material, each processing solution tank, and a spray device. The developing process is performed by spraying each pumped processing liquid from a spray nozzle. Recently, a method is also known in which a printing plate material is immersed and conveyed by a submerged guide roll or the like into a processing liquid tank filled with a processing liquid to perform processing. In such automatic processing,
Processing can be performed while replenishing each processing solution with a replenisher according to the processing amount, operating time, and the like. In addition, the electric conductivity can be detected by a sensor and replenished automatically. Further, a so-called disposable processing method in which processing is performed with a substantially unused processing liquid can also be applied.

The lithographic printing plate obtained as described above can be subjected to a printing step after applying a desensitized gum if desired. Is subjected to a burning process.

In the case of burning a lithographic printing plate, prior to burning, Japanese Patent Publication Nos. 61-2518 and 55-280.
No. 62, JP-A-62-131859 and JP-A-61-1596.
It is preferable to treat with a surface-regulating liquid as described in each of the publications No. 55.

[0118] As a method for this, a sponge or absorbent cotton impregnated with the surface conditioning liquid is applied onto a lithographic printing plate,
A method in which a printing plate is immersed in a vat filled with a surface conditioning liquid to apply the printing plate, an application using an automatic coater, or the like is applied. Further, it is preferable to make the application amount uniform with a squeegee or a squeegee roller after the application. The application amount of the surface conditioning liquid is generally 0.03 to 0.8 g / m ^2.
(Dry weight) is appropriate.

The lithographic printing plate to which the surface conditioning liquid has been applied is dried if necessary, and then burned with a burning processor (for example,
It is heated to a high temperature by a burning processor (BP-1300) sold by Fuji Photo Film Co., Ltd. The heating temperature and time in this case depend on the type of the component forming the image, but may be 1 to 180 ° C. to 300 ° C.
A range of up to 20 minutes is preferred.

The burned lithographic printing plate can be subjected to conventional treatments such as washing with water and gumming if necessary. However, a surface conditioning solution containing a water-soluble polymer compound or the like can be used. When is used, so-called desensitizing treatment such as gumming can be omitted.

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

[0122]

The present invention will be described in detail with reference to the following examples, but the present invention is not limited to these examples. [Synthesis of Polymer] (Synthesis Example 1: Synthesis of Polymer A) Polyvinyl butyral (Denka Butyral # 3000-4 manufactured by Denki Kagaku Kogyo Co., Ltd.) was used in a 1-liter three-necked round bottom flask equipped with a thermometer, a reflux condenser, and a stirrer. ) 25 g is dissolved by heating in 300 g of dioxane. Furthermore, after setting the reaction temperature to 100 ° C., 51.8 g of phthalic anhydride and 27.8 g of pyridine are added and reacted for 4 hours. This reaction solution is added little by little to a 4 liter aqueous solution of methanol / water (1: 3) to precipitate the polymer. This was collected by filtration and then dried under vacuum to obtain 31.0 g of a polymer, which was designated as polymer A. The acid content of polymer A is 2.5 meq /
g.

(Synthesis Example 2: Synthesis of Polymer B) Synthesis Example 1
In the same three-necked round-bottomed flask as used in the above, 20 g of polyvinyl formal (vinylec B-2 manufactured by Chisso) was added with acetic acid 24
Dissolve in 0 ml. After the reaction temperature was further raised to 100 ° C., 33.2 g of trimellitic anhydride and 18.0 g of sodium acetate were used.
And react for 4 hours. This reaction solution is added little by little to a 4 liter solution of methanol: water = 1: 3 to precipitate a polymer. This is collected by filtration, dried under vacuum,
5.8 g of the polymer was obtained and was designated as polymer B. The acid content of Polymer B was 2.7 meq / g.

(Synthesis Example 3: Synthesis of Polymer C) The reaction was carried out in the same manner as in Synthesis Example 2 except that the amount of trimellitic anhydride added was 67.2 g, to obtain 30.5 g of Polymer C. The acid content of Polymer C was 4.9 meq / g. (Synthesis Example 4: Synthesis of Polymer D) 31.6 g of Polymer D was obtained in the same manner as in Synthesis Example 1 except that 53.9 g of hexahydrophthalic anhydride was reacted instead of phthalic anhydride. The acid content of Polymer D was 2.2 meq / g. (Synthesis Example 5: Synthesis of Polymer E) 21.5 g of Polymer E was obtained in the same manner as in Synthesis Example 2, except that 16.9 g of maleic anhydride was reacted instead of trimellitic anhydride. The acid content of Purima E was 1.5 meq / g.

(Examples 1 to 5) [Preparation of support] 99.5% or more of aluminum and F
e 0.30%, Si 0.10%, Ti 0.02%, C
u A molten metal of JIS A1050 alloy containing 0.013% was subjected to cleaning treatment and cast. In the cleaning treatment, a degassing treatment was performed to remove unnecessary gases such as hydrogen in the molten metal, and a ceramic tube filter treatment was performed. The casting was performed by DC casting. The solidified ingot having a thickness of 500 mm was chamfered from the surface by 10 mm, and homogenized at 550 ° C. for 10 hours to prevent the intermetallic compound from becoming coarse. Next, after hot rolling at 400 ° C. and intermediate annealing in a continuous annealing furnace at 500 ° C. for 60 seconds, cold rolling was performed to obtain a rolled aluminum sheet having a sheet pressure of 0.30 mm. The center line average surface roughness Ra after cold rolling was controlled to 0.2 μm by controlling the roughness of the rolling roll. Then, it was subjected to a tension leveler to improve the flatness.

Next, a surface treatment for forming a lithographic printing plate support was performed. First, in order to remove the rolling oil on the surface of the aluminum plate, a degreasing treatment was performed with a 10% aqueous sodium aluminate solution at 50 ° C. for 30 seconds, and a 30% sulfuric acid aqueous solution was neutralized at 50 ° C. for 30 seconds and a smut removal treatment was performed.

Next, in order to improve the adhesion between the support and the photosensitive layer and to impart water retention to the non-image area, a so-called graining treatment for roughening the surface of the support was performed. 1%
Aqueous solution containing 0.5% nitric acid and 0.5% aluminum nitrate
° C while flowing an aluminum web in an aqueous solution, the anode-side electricity quantity 240 C / dm ² with an alternating waveform having a current density of 20 A / dm ² and a duty ratio of 1: 1 by an indirect feeding cell.
Electrolytic graining was performed by giving ² . Then 10%
Perform an etching treatment with a sodium aluminate aqueous solution at 50 ° C for 30 seconds, and neutralize with a 30% aqueous sulfuric acid solution at 50 ° C for 30 seconds.
Smut removal processing was performed.

In order to further improve abrasion resistance, chemical resistance and water retention, an oxide film was formed on the support by anodic oxidation. An anodic oxide film of 2.5 g / m ^{2 is} obtained by performing an electrolytic treatment with a direct current of 14 A / dm ² by an indirect power supply cell while carrying an aluminum web through the electrolyte using a 20% aqueous solution of sulfuric acid at 35 ° C. as an electrolyte. It was created.

Thereafter, a silicate treatment was performed to ensure hydrophilicity as a non-image portion of the printing plate. For the treatment, a 1.5% aqueous solution of sodium silicate No. 3 was maintained at 70 ° C., passed through the aluminum web so that the contact time was 15 seconds, and further washed with water. S
The attached amount of i was 10 mg / m ² . Ra (center line surface roughness) of the support thus prepared was 0.25 μm.

[Undercoating] Next, the following undercoating solution was applied to the aluminum support with a wire bar, and dried at 90 ° C. for 30 seconds using a hot air drier. The coating amount after drying was 10 mg / m ² .

<Undercoat liquid> 0.1 g of a copolymer of ethyl methacrylate and 2-acrylamido-2-methyl-1-propanesulfonic acid sodium salt in a molar ratio of 75:15 0.1 g 2-aminoethylphosphonic acid 0.1 g 50 g of methanol 50 g of ion exchange water

[Photosensitive Layer] Next, the following solution [P] was prepared, applied to the above-mentioned primed aluminum plate using a wire bar, and dried at 115 ° C. for 45 seconds with a hot air drier. Negative type lithographic printing plate precursor [P-1]-[P-
5]. The coating amount after drying is 1.2 to 1.3 g / m ^2.
Was within the range. Table 1 shows the types of the specific binder polymer (D) used at this time.

<Solution [P]> (A) Infrared absorber [IR-6] (structure below) 0.08 g (B) Thermal radical initiator [OI-6] (structure below) 0.30 g (( C) Dipentaerythritol hexaacrylate 1.00 g Binder polymer (D) (compound shown in Table 1) 1.00 g Victoria navy blue naphthalene sulfonate 0.04 g Fluorosurfactant 0.01 g (mega) Fac F-176, manufactured by Dainippon Ink and Chemicals, Inc.)-Methyl ethyl ketone 9.0 g-Methanol 10.0 g-1-methoxy-2-propanol 8.0 g

[0134]

[Table 1]

[0135]

Embedded image

[Exposure] The negative type lithographic printing plate precursors [P-1] to [P-5] were prepared by using a Trendsetter made by Creo Corporation equipped with a water-cooled 40 W infrared semiconductor laser.
At 3244VFS, output 9W, outer drum rotation speed 21
Exposure was performed under the conditions of 0 rpm, plate surface energy 100 mJ / cm ² , and resolution 2400 dpi.

[Development processing] After the exposure, development processing was performed using an automatic developing machine Stublon 900N manufactured by Fuji Photo Film Co., Ltd. As the developing solution, a 1: 1 aqueous dilution of DN-3C manufactured by Fuji Photo Film Co., Ltd. was used for both the charging solution and the replenishing solution. The temperature of the developing bath was 30 ° C. Also, the finisher
A 1: 1 aqueous dilution of FN-6 manufactured by Fuji Photo Film Co., Ltd. was used.

[Evaluation of Printing and Printing Durability] Next, the lithographic printing plates [P-1] to [P-5] were printed using a printing machine Lithrone manufactured by Komori Corporation. At this time, it was visually evaluated how many sheets could be printed while maintaining a sufficient ink density. The results are also shown in Table 1.

As is clear from Table 1, the lithographic printing plate according to Examples of the present invention was prepared using any polymer having a repeating unit represented by the general formula (I).
It was found that a large number of prints were possible and that the printing durability was excellent.

(Examples 6 to 9) As the binder polymer (D), polymers A to E which are polymers having a repeating unit represented by the general formula (I) of the present invention are used.
In addition to the above, polymer F [allyl methacrylate / methacrylic acid copolymer (polymerization molar ratio: 80/20, polymerization average molecular weight: about 120,000)] and polymer G [methyl methacrylate / methacrylic acid copolymer having no repeating unit] Polymer (polymerization molar ratio: 85/15, polymerization average molecular weight of about 12
Lithographic printing plates [P-6] to [P-9] were prepared in the same manner as in Example 1, except that the amount shown in Table 2 below was used. The sex was evaluated. The results are shown in Table 2 below.

(Comparative Example 1) Lithographic printing was performed in the same manner as in Example 1 except that only the polymer G having no repeating unit represented by the general formula (I) of the present invention was used as the binder polymer (D). A plate [P-10] was prepared, and Example 1 was prepared.
The printing durability was evaluated in the same manner as described above. The results are shown in Table 2 below.

[0142]

[Table 2]

As is clear from Table 2, even when other binder polymers are used in combination, the lithographic printing plates according to the examples of the present invention can print a large number of sheets and are excellent in printing durability. I understand. On the other hand, the lithographic printing plate of Comparative Example 1 using only a polymer having no repeating unit represented by the general formula (I) as a binder polymer is as follows:
It was confirmed that the printing durability was poor despite all the other conditions being the same.

[0144]

According to the present invention, recording is performed using a solid-state laser and a semiconductor laser that emit infrared light.
It is possible to provide a negative type lithographic printing plate precursor which can be directly recorded from digital data of a computer or the like, and has excellent printing durability in which many good printed matters can be obtained during printing.

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) G03F 7/027 G03F 7/027 F term (reference) 2H025 AA01 AA12 AA14 AB03 AC08 AD01 BC13 BC34 BC43 BE07 CA00 CA14 CA25 CA26 CA41 CB06 CB07 CB14 CC12 CC13 FA17 2H096 AA07 BA05 EA01 EA04 EA23 GA08 4J100 AD02P BA20H BC59H CA01 CA31 HA11 HA43 HC16 HC17 HC18 HC19 HC28 HC30 HC45 HC59

Claims (1)

[Claims] 1. A support, comprising: (A) an infrared absorber;
A photosensitive layer having (B) a thermal radical initiator, (C) a radical polymerizable compound, and (D) a binder polymer is provided. The (D) binder polymer is represented by the following general formula (I). Negative-working lithographic printing plate precursor comprising a polymer having a repeating unit. Embedded image In the formula, R ¹ represents a hydrogen atom or an alkyl group which may have a substituent, R ² represents an alkyl group having no substituent, R ³ represents an aliphatic group having a carboxylic acid group, Alternatively, it represents an aromatic hydrocarbon group. n ¹ , n ² , n ³ and n ⁴ indicate mol% of each repeating unit, and each is in the following range. n ¹ = 5 to 85, n ² = 0 to 60, n ³ = 0 to 20,
n ⁴ = 3~60.