JP2006309145A - Photosensitive lithographic printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive lithographic printing plate which has high sensitivity, high time-lapse stability and is excellent in dot uniformity, and to further provide a photosensitive lithographic printing plate which is suitable for high-definition AM screen printing or FM screen printing of screen line number of 200 or more. <P>SOLUTION: The photosensitive lithographic printing plate is obtained by disposing, on an aluminum support, a photopolymerizable photosensitive layer containing a polymer compound including a structure unit (i) having a carbon-carbon double bond in a side chain, a structure unit (ii) having an acid group, and at least one structure unit (iii) selected from (a) a structure unit having an ethyleneoxy group, (b) a structure unit having a cyclohexyl group, and (c) a structure unit having two or more hydroxy groups. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a photosensitive lithographic printing plate, and relates to a photosensitive lithographic printing plate suitable for drawing with a laser beam. More specifically, the present invention relates to a photosensitive lithographic printing plate suitable for high-definition AM screen printing and FM screen printing having a high sensitivity and a screen line number of 200 lines or more.

  Conventionally, as a method for forming an image by exposure of a photopolymerizable composition, a layer of a photopolymerizable composition comprising a polymer binder, an ethylenically unsaturated compound, a photopolymerization initiator, and a sensitizing dye is used. A method of forming a cured relief image by forming an image on the surface and polymerizing and curing the ethylenically unsaturated compound in the exposed area, and then dissolving and removing the non-image area with a developer has been widely used. Yes.

  In recent years, image information has been digitized via a computer, and a CTP system using an Ar ion laser, an FD-YAG laser, and a short wavelength semiconductor laser having an oscillation wavelength of 350 nm to 450 nm has been developed and is required for practical use.

The development of highly sensitive and highly stable photoinitiating systems sensitive to these lasers has been extensively performed. Monroe et al., Chemical Review, 93, 435 (1993) (Non-Patent Document 1) and R.C. S. Many photoinitiating systems described in Davidson, Journal of Photochemistry and Biology A: Chcmistry, 73, 81 (1993), JP-A-9-80750 (Patent Document 1), JP-A-2001-42524 No. (Patent Document 2), Japanese Patent Application Laid-Open No. 2000-3097724 (Patent Document 3), etc., are known.
In particular, research on a photoinitiation system compatible with a violet laser (oscillation wavelength of 405 nm), which is expected as an inexpensive and small oscillation laser in the future, has recently been actively conducted, for example, a combination of an optical brightener and a lophine dimer -295426 (Patent Document 4)), and a combined photoinitiating system of a short wave merocyanine dye and a titanocene compound (Japanese Patent Laid-Open No. 2001-100412 (Patent Document 5)) has been reported. The development of these photoinitiating systems has made it possible to create photosensitive lithographic printing plates that achieve both stability and practical sensitivity, for example, lithographic printing plates compatible with low-cost violet lasers. There is a high demand for higher sensitivity for the purpose.

  Further, for the purpose of high sensitivity and high printing durability, high molecular compounds having an unsaturated group in the side chain have been studied. For example, a binder having an allyl group in a side chain (for example, JP-A-9-230594 (Patent Document 6)), a binder having an acrylic group in a side chain (for example, JP-A-2002-182389 (Patent Document 7)), etc. Can do.

  On the other hand, the printing market is diversified, and there is an increasing demand for high-definition printing using a high number of lines and an FM screen. In response to this demand, the photopolymerization reaction is not sufficient because it is difficult to obtain minute dots and to obtain uniform dot performance in a large area because of the influence of oxygen that inhibits polymerization and post-polymerization that occurs later in the polymerization reaction. What has the performance is not obtained. Furthermore, there are few documents, patents, etc. that suggest specific improvement measures.

Bluce M.M. Monroe et al., Chemical Review, 93, 435 (1993). R. S. By Davidson, Journal of Photochemistry and Biology A: Chcmory, 73, 81 (1993). Japanese Patent Laid-Open No. 9-80750 JP 2001-42524 A JP 2000-3097724 A JP 2003-295426 A Japanese Patent Laid-Open No. 2001-100412 Japanese Patent Laid-Open No. 9-230594 JP 2002-182389 A

  Accordingly, an object of the present invention is to provide a photosensitive lithographic printing plate having high sensitivity, high temporal stability and excellent halftone dot uniformity. Another object is to provide a photosensitive lithographic printing plate suitable for high-definition AM screen printing and FM screen printing having a screen line number of 200 lines or more.

In order to solve the above problems, the present inventor provides a photosensitive lithographic printing plate having high sensitivity, good temporal stability and halftone dot uniformity by adding a polymer compound having a specific structure to the photosensitive layer. And the present inventors have found that it is possible to control the curability of the intermediate exposure part.
That is, the said subject was achieved by the following structures.

(1) On the aluminum support, the structural unit (i) having a carbon-carbon double bond in the side chain, the structural unit (ii) having an acid group, and the structural units shown below (a) to (c) A photosensitive lithographic printing plate comprising a photopolymerizable photosensitive layer containing a polymer compound having at least one structural unit (iii) selected from:
(A) Structural unit having an ethyleneoxy group (b) Structural unit having a cyclohexyl group (c) Structural unit having two or more hydroxyl groups (2) The polymer compound has a carbon-carbon double bond amount of 1 g by mass. The photosensitive lithographic printing as described in (1) above, which is a polymer compound in the range of 0.2 to 2.3 mmol per liter and an acid value in the range of 0.5 to 2.0 Edition.
(3) The photosensitive lithographic printing plate as described in (1) or (2) above, wherein the photopolymerizable photosensitive layer further contains a photopolymerization initiator and an ethylenically unsaturated polymerizable compound.
(4) The photosensitive lithographic printing plate as described in (3) above, wherein the photopolymerization initiator is a hexaarylbisimidazole compound.
(5) The photosensitive lithographic printing plate as described in any one of (1) to (4) above, wherein an oxygen-blocking protective layer is provided on the photopolymerizable photosensitive layer.

  According to the present invention, it is possible to provide a photosensitive lithographic printing plate having high sensitivity, high temporal stability, excellent halftone dot uniformity, and suitable for high-definition printing applications.

The photosensitive lithographic printing plate of the present invention will be described in detail.
(Photopolymerizable photosensitive layer)
The photosensitive lithographic printing plate of the present invention has a structure selected from a structural unit having a carbon-carbon double bond in the side chain, a structural unit having an acid group, and the structural units shown below in (a) to (c). It has a photopolymerizable photosensitive layer (hereinafter, also simply referred to as a photosensitive layer) containing a polymer compound containing a unit. (A) a structural unit having an ethyleneoxy group,
(B) a structural unit having a cyclohexyl group,
(C) A structural unit having two or more hydroxyl groups.

Such a photosensitive lithographic printing plate can be recorded directly from digital data such as a computer by exposure with an argon ion laser, FD-YAG laser, violet laser, etc., and can withstand high-definition printing. It is possible to form a fine image. In addition, in order to keep the handleability under yellow light, which is one advantage of using a violet laser, it is necessary to adjust the photosensitive wavelength of the photoinitiating system, and the hexaarylbisimidazole compound has an absorption wavelength. It is used in the present invention as an effective photoinitiator due to its short wavelength and high sensitivity.
Hereinafter, the photopolymerizable photosensitive layer of the photosensitive lithographic printing plate of the present invention will be described in order.

<Polymer compound>
The polymer compound used for the photosensitive layer in the present invention has at least (i) a structural unit having a carbon-carbon double bond in the side chain, (ii) a structural unit having an acid group, and (iii) a specific structure. It is essential to contain the structural unit of the third component, and it may have structural units of other components as necessary.

<(I) Structural unit having a carbon-carbon double bond in the side chain>
The polymer compound used in the present invention is required to have at least one carbon-carbon double bond in the side chain in its structure, and the “carbon-carbon double bond” structure is preferably a specific example. As such a mode, what has at least 1 or more among groups represented by the following general formula (1) thru | or general formula (3) in a side chain is mentioned.
This polymer compound has at least one “carbon-carbon double bond” in the side chain, and a group containing “carbon-carbon double bond” in the structure thereof, for example, the following general formula (1) It suffices that at least one group represented by (3) is present in the side chain, and a plurality of such groups may be present, and all of the groups represented by these general formulas (1) to (3) You may have at the same time.

  Hereinafter, groups represented by the general formulas (1) to (3) will be described in detail.

In general formulas (1) to (3), R ^{1 to} R ¹¹ each independently represent a hydrogen atom or a monovalent organic group. X and Y each independently represent an oxygen atom, a sulfur atom, or —N (R ¹² ) —, and R ¹² represents a hydrogen atom or a monovalent organic group. Z represents an oxygen atom, a sulfur atom, —N (R ¹² ) —, or an optionally substituted phenylene group.

In the general formula (1), R ^{1 to} R ³ each independently represents a hydrogen atom or a monovalent organic group. R ¹ is preferably a hydrogen atom or an alkyl group which may have a substituent. Among them, a hydrogen atom or a methyl group is preferable because of high radical reactivity. R ² and R ³ are each preferably a hydrogen atom, a halogen atom, an amino group, a carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, an optionally substituted alkyl group, or a substituted group. An aryl group that may have a group, an alkoxy group that may have a substituent, an aryloxy group that may have a substituent, an alkylamino group that may have a substituent, and a substituent An arylamino group which may have a substituent, an alkylsulfonyl group which may have a substituent, an arylsulfonyl group which may have a substituent, and the like. Among them, a hydrogen atom, a carboxyl group, an alkoxycarbonyl group, a substituent An alkyl group which may have a substituent and an aryl group which may have a substituent are more preferable because of high radical reactivity.

X represents an oxygen atom, a sulfur atom, or —N (R ¹² ) —, and R ¹² represents a hydrogen atom or a monovalent organic group. Here, examples of R ¹² include an alkyl group which may have a substituent. Among them, a hydrogen atom, a methyl group, an ethyl group, and an isopropyl group are preferable because of high radical reactivity.

  Here, examples of the substituent that can be introduced include an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkoxy group, an aryloxy group, a halogen atom, an amino group, an alkylamino group, an arylamino group, a carboxyl group, an alkoxycarbonyl group, A sulfo group, a nitro group, a cyano group, an amide group, an alkylsulfonyl group, an arylsulfonyl group and the like can be mentioned.

In the general formula (2), R ^{4 to} R ⁸ each independently represent a hydrogen atom or a monovalent organic group. R ^{4 to} R ⁸ are preferably a hydrogen atom, a halogen atom, an amino group, a dialkylamino group, a carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, an alkyl group which may have a substituent, An aryl group that may have a substituent, an alkoxy group that may have a substituent, an aryloxy group that may have a substituent, an alkylamino group that may have a substituent, and a substituent. An arylamino group which may have a substituent, an alkylsulfonyl group which may have a substituent, an arylsulfonyl group which may have a substituent, and the like. Among them, a hydrogen atom, a carboxyl group, an alkoxycarbonyl group, a substituent An alkyl group which may have a group and an aryl group which may have a substituent are more preferable.

Examples of the substituent that can be introduced are the same as those in the general formula (1). Y represents an oxygen atom, a sulfur atom, or —N (R ¹² ) —. R ¹² has the same meaning as R ¹² in general formula (1), and preferred examples are also the same.

In the general formula (3), R ^{9 to} R ¹¹ each independently represents a hydrogen atom or a monovalent organic group. R ⁹ is preferably a hydrogen atom or an alkyl group which may have a substituent. Among them, a hydrogen atom or a methyl group is preferable because of high radical reactivity. R ¹⁰ and R ¹¹ preferably each independently have a hydrogen atom, a halogen atom, an amino group, a dialkylamino group, a carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, or a substituent. A good alkyl group, an aryl group which may have a substituent, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, an alkylamino group which may have a substituent, An arylamino group which may have a substituent, an alkylsulfonyl group which may have a substituent, an arylsulfonyl group which may have a substituent, and the like are mentioned. Among them, a hydrogen atom, a carboxyl group, alkoxy A carbonyl group, an alkyl group which may have a substituent, and an aryl group which may have a substituent are more preferable because of high radical reactivity.

Here, examples of the substituent that can be introduced are the same as those in the general formula (1). Z represents an oxygen atom, a sulfur atom, —N (R ¹² ) —, or an optionally substituted phenylene group. R ¹² has the same meaning as R ¹² in general formula (1), and preferred examples are also the same.

  It is preferable that a high molecular compound has a repeating unit represented by following General formula (4) as a structural unit which has a carbon-carbon double bond in a side chain.

In General Formula (4), R ^1a represents a hydrogen atom or a methyl group, and R ^2a represents a group represented by General Formulas (1) to (3).
The content of the repeating unit represented by the general formula (4) in the polymer compound is preferably 2 to 28 mol%, and more preferably 10 to 25 mol%.

  The content of “carbon-carbon double bond” in the polymer compound of the present invention is preferably in the range of 0.2 to 2.3 mmol, and in the range of 0.7 to 1.5 mmol, per 1 g of the polymer compound. More preferred. When the amount is 0.2 to 2.3 mmol, sufficient sensitivity is obtained, storage stability is improved, and high-definition image formation is possible. By setting the content of “carbon-carbon double bond” to 2.3 mmol or less, high-definition image formation becomes possible. The reason is that the dark polymerization in the unexposed area can only be reduced. In other words, it is presumed that it is possible to prevent the occurrence of fringe around the halftone dot and the occurrence of brush unevenness in development when the halftone dot is exposed with a laser.

<(Ii) Structural unit having an acid group>
The polymer compound according to the present invention must contain a structural unit having an acid group in order to improve various performances such as non-image area removability. The acid value of the polymer compound of the present invention is preferably in the range of 0.5 to 2.0. Here, the acid value refers to the number of mg of potassium hydroxide necessary to neutralize free fatty acids contained in 1 g of a sample. The acid value is measured by dissolving the sample in a benzene-ethanol mixed solvent or the like, titrating with a potassium hydroxide solution whose titer is accurately known, and calculating from the neutralization amount. 0.5 or more is preferable from the viewpoint of sufficient removal of non-image areas and prevention of residual film. In particular, when heat treatment is performed for the purpose of increasing sensitivity after exposure, the effect of preventing the formation of residual film is great. It is preferably 2.0 or less from the viewpoint of reducing the damage of the exposed portion by the alkali developer and preventing the deterioration of the image strength and the printing durability.
Examples of the acid group include carboxylic acid, sulfonic acid, phosphoric acid group, phenolic hydroxyl group, and the like, and particularly preferred are carboxylic acid and phenolic hydroxyl group. Examples of the polymerizable compound containing a carboxylic acid include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, incrotonic acid, maleic acid, p-carboxylstyrene, and particularly preferred are acrylic acid and methacrylic acid. P-carboxylstyrene.
4-hydroxystyrene is mentioned as a polymeric compound which has a phenolic hydroxyl group.
The structural unit having an acid group can be used alone or in combination of two or more. The content of the structural unit having an acid group is preferably from 0.1 mol% to 50 mol%, particularly preferably alkaline water. From the viewpoint of suppressing image strength damage due to development, it is 0.1 mol% to 40 mol%.

<(Iii) Specific structural unit>
The structural unit of the third component essential to the polymer compound of the present invention includes (a) a structural unit having an ethyleneoxy group, (b) a structural unit having a cyclohexyl group, and (C) a structure having two or more hydroxyl groups. It can be used by selecting from the unit. The high molecular compound of this invention may have 1 type in the structural unit of (a)-(c), and may have 2 or more types. In addition, one structural unit may have two or more of the same or different groups having 2 or more, preferably 2 to 6 ethyleneoxy groups, cyclohexyl groups, and hydroxyl groups.
By containing the structural unit of the third component, the compatibility between the components in the photosensitive composition for forming the photosensitive layer is improved, the layer separation with time is suppressed, and the developer This makes it possible to adjust the solubility in water, so that an effect appears in improving the stability over time.
A suitable content of the structural unit of these third components is 5 mol% to 70 mol% as a total amount, and more preferably 10 mol% to 50 mol%.

  Furthermore, the polymer compound according to the present invention is not limited to the structural units (i), (ii) and (iii) as long as the effects of the present invention are not impaired for the purpose of improving various performances such as image strength. In addition, it is also a preferred embodiment to contain structural units corresponding to other polymerizable compounds.

  Examples of such polymerizable compounds include polymerizable compounds selected from acrylic esters, methacrylic esters, acrylamides, methacrylamides, styrenes, acrylonitriles, methacrylonitriles, and the like.

  Specifically, for example, acrylic acid esters such as alkyl acrylate (the alkyl group preferably has 1 to 20 carbon atoms) (specifically, for example, benzyl acrylate, 4-biphenyl acrylate, butyl Acrylate, sec-butyl acrylate, t-butyl acrylate, 4-t-butylphenyl acrylate, 4-chlorophenyl acrylate, pentachlorophenyl acrylate, 4-cyanobenzyl acrylate, cyanomethyl acrylate, cyclohexyl acrylate, 2-ethoxyethyl acrylate, ethyl acrylate 2-ethylhexyl acrylate, heptyl acrylate, hexyl acrylate, isobornyl acrylate, isopropyl acrylate, methyl acrylate, 3,5-dimethyl Adamantyl acrylate, 2-naphthyl acrylate, neopentyl acrylate, octyl acrylate, phenethyl acrylate, phenyl acrylate, propyl acrylate, tolyl acrylate, amyl acrylate, tetrahydrofurfuryl acrylate, 2-hydroxyethyl acrylate, 3-hydroxypropyl acrylate, 2-hydroxy Propyl acrylate, 4-hydroxybutyl acrylate, 5-hydroxypentyl acrylate, allyl acrylate, 2-allyloxyethyl acrylate, propargyl acrylate, etc.)

  Methacrylic acid esters (eg, benzyl methacrylate, 4-biphenyl methacrylate, butyl methacrylate, sec-butyl methacrylate, t-butyl methacrylate, 4- t-butylphenyl methacrylate, 4-chlorophenyl methacrylate, pentachlorophenyl methacrylate, 4-cyanophenyl methacrylate, cyanomethyl methacrylate, cyclohexyl methacrylate, 2-ethoxyethyl methacrylate, ethyl methacrylate, 2-ethylhexyl methacrylate, heptyl methacrylate, hexyl methacrylate, isoboro Nyl methacrylate, isopropyl methacrylate, methyl methacrylate, 3,5- Methyl adamantyl methacrylate, 2-naphthyl methacrylate, neopentyl methacrylate, octyl methacrylate, phenethyl methacrylate, phenyl methacrylate, propyl methacrylate, tolyl methacrylate, amyl methacrylate, tetrahydrofurfuryl methacrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl methacrylate, 2- (Hydroxypropyl methacrylate, 4-hydroxybutyl methacrylate, 5-hydroxypentyl methacrylate, allyl methacrylate, 2-allyloxyethyl methacrylate, propargyl methacrylate, etc.)

  Styrenes such as styrene and alkyl styrene (for example, methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, isopropyl styrene, butyl styrene, hexyl styrene, cyclohexyl styrene, decyl styrene, benzyl styrene, chloromethyl styrene, Trifluoromethyl styrene, ethoxymethyl styrene, acetoxymethyl styrene, etc.), alkoxy styrene (eg methoxy styrene, 4-methoxy-3-methyl styrene, dimethoxy styrene, etc.), halogen styrene (eg chloro styrene, dichloro styrene, trichloro styrene, Tetrachlorostyrene, pentachlorostyrene, bromostyrene, dibromostyrene, iodostyrene, fluorostyrene, trifluoro Ren, 2-bromo-4-trifluoromethyl styrene, 4-fluoro-3-trifluoromethyl styrene etc.), acrylonitrile, methacrylonitrile, and the like.

Of these polymerizable compounds, methacrylic acid esters, acrylamides, methacrylamides, and styrenes are preferably used, and benzyl methacrylate, t-butyl methacrylate, 4 are particularly preferably used. -T-butylphenyl methacrylate, pentachlorophenyl methacrylate, 4-cyanophenyl methacrylate, cyclohexyl methacrylate, ethyl methacrylate, 2-ethylhexyl methacrylate, isobornyl methacrylate, isopropyl methacrylate, methyl methacrylate, 3,5-dimethyladamantyl methacrylate, 2-naphthyl Methacrylate, neopentyl methacrylate, phenyl methacrylate, tetrahydrofurfuryl methacrylate, 2-hydroxyethyl methacrylate Over DOO, 3-hydroxypropyl methacrylate, 2-hydroxypropyl methacrylate, allyl methacrylate,

  Acrylamide, N-methylacrylamide, N-isopropylacrylamide, morpholylacrylamide, piperidylacrylamide, Nt-butylacrylamide, N-cyclohexylacrylamide, N-phenylacrylamide, N-naphthylacrylamide, N-hydroxymethylacrylamide, N- Hydroxyethylacrylamide, N-allylacrylamide, 4-hydroxyphenylacrylamide, 2-hydroxyphenylacrylamide, N, N-dimethylacrylamide, N, N-diisopropylacrylamide, N, N-di-t-butylacrylamide, N, N- Dicyclohexylacrylamide, N, N-phenylacrylamide, N, N-dihydroxyethylacrylamide, N, N-diallylacryl Bromide,

  Methacrylamide, N-methylmethacrylamide, N-isopropylmethacrylamide, morpholylmethacrylamide, piperidylmethacrylamide, Nt-butylmethacrylamide, N-cyclohexylmethacrylamide, N-phenylmethacrylamide, N-naphthylmethacrylamide N-hydroxymethylmethacrylamide, N-hydroxyethylmethacrylamide, N-allylmethacrylamide, 4-hydroxyphenylmethacrylamide, 2-hydroxyphenylmethacrylamide, N, N-dimethylmethacrylamide, N, N-diisopropylmethacrylamide N, N-di-t-butylmethacrylamide, N, N-dicyclohexylmethacrylamide, N, N-phenylmethacrylamide, N, N-dihydroxyethylmethacrylate Acrylamide, N, N-diallyl methacrylamide,

  Styrene, methyl styrene, dimethyl styrene, trimethyl styrene, isopropyl styrene, butyl styrene, cyclohexyl styrene, chloromethyl styrene, trifluoromethyl styrene, ethoxymethyl styrene, acetoxymethyl styrene, methoxy styrene, 4-methoxy-3-methyl styrene , Chlorostyrene, dichlorostyrene, trichlorostyrene, tetrachlorostyrene, pentachlorostyrene, bromostyrene, dibromostyrene, iodostyrene, fluorostyrene, trifluorostyrene, 2-bromo-4-trifluoromethylstyrene, 4- Examples include fluoro-3-trifluoromethylstyrene.

  These may be used alone or in combination of two or more. In the polymer compound according to the present invention, the content of these copolymer components is preferably 0 to 90 mol%, particularly preferably 0 mol. % To 60 mol%. When the content is in the above range, a suitable film curing effect can be obtained.

The polymer compound according to the present invention can be synthesized, for example, by a known method such as radical polymerization using monomers corresponding to each structural unit.
Examples of the solvent used in the synthesis of the polymer compound include ethylene dichloride, cyclohexanone, methyl ethyl ketone, acetone, methanol, ethanol, propanol, butanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, Examples include 1-methoxy-2-propanol, 1-methoxy-2-propyl acetate, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, toluene, ethyl acetate, methyl lactate, and ethyl lactate. These solvents may be used alone or in combination of two or more.

The polymer compound according to the present invention has a mass average molecular weight of preferably 6,000 or more, and more preferably in the range of 50,000 to 200,000. In view of an appropriate glass transition temperature and good image strength, 6,000 or more is preferable. In view of good developability, 200,000 or less is preferable.
Further, the polymer compound according to the present invention may contain an unreacted monomer. In this case, the proportion of the unreacted monomer in the polymer compound is desirably 15% by mass or less.

  The polymer compound according to the present invention may be used alone or in combination of two or more. Furthermore, the photosensitive layer may contain a polymer compound other than the polymer compound according to the present invention, and such a polymer compound is 80% by mass or less in the total mass with the polymer compound according to the present invention. It is preferable that it is 50 mass% or less.

  The content of the polymer compound according to the present invention contained in the photosensitive layer of the photosensitive lithographic printing plate of the present invention is preferably 5 to 95% by mass, more preferably 10 to 85% by mass in terms of solid content. When an image is formed, 5% by mass or more is preferable in terms of the strength of an excellent image area. Moreover, 95 mass% or less is preferable at the point of favorable image formation.

  Specific examples of the polymer compound according to the present invention include the following polymer compounds, but are not limited thereto.

The photosensitive layer of the photosensitive lithographic printing plate according to the invention preferably contains a photopolymerization initiator and an ethylenically unsaturated polymerizable compound.
<Photopolymerization initiator>
As the photopolymerization initiator contained in the photosensitive layer of the photosensitive lithographic printing plate in the present invention, various photopolymerization initiators, photopolymerization initiators and sensitization known in patents, documents, etc., depending on the wavelength of the light source used. A photoinitiating system with a pigment (a pigment or dye described later) or a combined system (photoinitiating system) of two or more photopolymerization initiators can be appropriately selected and used. Specific examples are listed below, but are not limited thereto.

Various photoinitiating systems have been proposed in the case of using visible light of 400 nm or more, Ar laser, second harmonic of a semiconductor laser, or SHG-YAG laser as a light source, for example, US Pat. No. 2,850,445. Certain photoreductive dyes described in No. 1, for example, rose bengal, eosin, erythrodin, or the like, or a combination of a dye and an initiator, for example, a combined initiator system of a dye and an amine (Japanese Patent Publication No. 44-20189) ), A combination system of hexaarylbisimidazole, radical generator and dye (Japanese Patent Publication No. 45-37377), a system of hexaarylbisimidazole and p-dialkylaminobenzylidene ketone (Japanese Patent Publication No. 47-2528, JP 54-155292), a system of a cyclic cis-α-dicarbonyl compound and a dye (JP-A-48-84183). Each publication), a system of a cyclic triazine and a merocyanine dye (Japanese Patent Laid-Open No. 54-151024), a system of 3-ketocoumarin and an activator (Japanese Patent Laid-Open No. 52-112681, Japanese Patent Publication No. 58-15503), Bisimidazole, styrene derivative, thiol system (Japanese Patent Laid-Open No. 59-140203), organic peroxide and dye system (Japanese Patent Laid-Open Nos. 59-1504, 59-140203, 59-140) 189340, JP-A-62-174203, JP-B-62-1641, US Pat. No. 4,766,055), a system of dye and active halogen compound (JP-A-63-258903, JP-A-2-63054, etc.) JP-A-62-143044, JP-A-62-1050242, JP-A-64-13140, JP-A-64-131 41, JP 64-13142, JP 64-13143, JP 64-13144, JP 64-17048, JP 1-222903, JP 1-2298348, (Kaihei 1-138204, etc.), dyes having a rhodanine ring and radical generators (JP-A-2-17943, JP-A-2-244050), titanocene and 3-ketocoumarin dyes (JP JP-A 63-221110), systems in which titanocene and xanthene dyes and addition-polymerizable ethylenically unsaturated bond-containing compounds containing amino groups or urethane groups are combined (JP-A-4-221958 and JP-A-4-219756) Publication), titanocene and a specific merocyanine dye system (JP-A-6-295061), having titanocene and benzopyran ring That the dye system (JP-A-8-334897 JP), and the like.

  Recently, a laser having a wavelength of 400 to 410 nm (violet laser) has been developed, and a photoinitiating system exhibiting high sensitivity at a wavelength of 450 nm or less that responds to it has been developed, and these photoinitiating systems are also used. For example, a cationic dye / borate system (JP-A-11-34647), a merocyanine dye / titanocene system (JP-A 2000-147663), a carbazole type dye / titanocene system (JP-A 2001-42524), an optical enhancement A white agent / hexaarylbisimidazole (Japanese Patent Laid-Open No. 2003-295426), an oxazole dye / hexaarylbisimidazole (WO2004-074930) and the like can be mentioned. In the present invention, a system using a hexaarylbisimidazole compound is particularly preferable in terms of sensitivity and photosensitive wavelength.

As the hexaarylbisimidazole compound, various compounds described in EP24629, EP107792, US4410621, EP215453, DE32111312 and the like can be used.
Preferable specific examples of the hexaarylbisimidazole compound include, for example, 2,4,5,2 ′, 4 ′, 5′-hexaphenylbisimidazole, 2,2′-bis (2-chlorophenyl) -4,5, 4 ′, 5′-tetraphenylbisimidazole, 2,2′-bis (2-bromophenyl) -4,5,4 ′, 5′-tetraphenylbisimidazole, 2,2′-bis (2,4- Dichlorophenyl) -4,5,4 ′, 5′-tetraphenylbisimidazole, 2,2′-bis (2-chlorophenyl) -4,5,4 ′, 5′-tetrakis (3-methoxyphenyl) -bisimidazole 2,5,2 ′, 5′-tetrakis (2-chlorophenyl) -4,4′-bis (3,4-dimethoxyphenyl) bisimidazole, 2,2′-bis (2,6-dichlorophenyl) -4 , 5,4 ' 5′-tetraphenylbisimidazole, 2,2′-bis (2-nitrophenyl) -4,5,4 ′, 5′-tetraphenylbisimidazole, 2,2′-di-o-tolyl-4,5 , 4 ′, 5′-tetraphenylbisimidazole, 2,2′-bis (2-ethoxyphenyl) -4,5,4 ′, 5′-tetraphenylbisimidazole, and 2,2′-bis (2, 6-difluorophenyl) -4,5,4 ′, 5′-tetraphenylbisimidazole and the like.

Furthermore, as required for the photopolymerization initiator, so-called co-sensitizers include thiol compounds such as 2-mercaptobenzthiazole, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, N-phenylglycine, and N, N-dialkyl. By adding a hydrogen donating compound such as an amine compound such as an amino aromatic alkyl ester, the photoinitiating ability can be further enhanced. As a co-sensitizer, a thiol compound is preferable.

  These photopolymerization initiators (systems) are used in an amount of 0.05 to 100 parts by weight, preferably 0.1 to 70 parts by weight, and more preferably 0.000 parts by weight with respect to 100 parts by weight of the ethylenically unsaturated polymerizable compound. It is the range of 2-50 mass parts.

<Ethylene unsaturated polymerizable compound>
An ethylenically unsaturated polymerizable compound is a compound having an ethylenically unsaturated bond that undergoes addition polymerization, crosslinking, and curing by the action of a photopolymerization initiator when irradiated with actinic rays. The compound having an ethylenically unsaturated bond capable of addition polymerization can be arbitrarily selected from compounds having at least one, preferably two or more terminal ethylenically unsaturated bonds. For example, those having chemical forms such as monomers, prepolymers, that is, dimers, trimers and oligomers, copolymers thereof, and mixtures thereof.

  Examples of monomers include esters of unsaturated carboxylic acids (eg, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.) and aliphatic polyhydric alcohol compounds, unsaturated carboxylic acids and aliphatic Examples include amides with polyvalent amine compounds. Specific examples of the monomer of an ester of an aliphatic polyhydric alcohol compound and an unsaturated carboxylic acid include acrylic acid esters such as ethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butanediol diacrylate, and 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 pentaacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, polyester Examples include acrylate oligomers.

  Methacrylic acid esters include tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, Hexanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol dimethacrylate, dipentaerythritol hexamethacrylate, dipentaerythritol pentamethacrylate, sorbitol trimethacrylate, sorbitol tetramethacrylate, bis [ - (3-methacryloxy-2-hydroxypropoxy) phenyl] dimethyl methane, bis - [p- methacryloxyethoxy] phenyl] dimethyl methane.

Itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,5-butanediol diitaconate, 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate And sorbitol tetritaconate.
Examples of crotonic acid esters include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, and sorbitol tetradicrotonate.
Examples of isocrotonic acid esters include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate.

Examples of maleic acid esters include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate. Furthermore, the mixture of the above-mentioned ester monomer can also be mentioned.
Specific examples of amide monomers of aliphatic polyvalent amine compounds and unsaturated carboxylic acids include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6-hexamethylene bis. -Methacrylamide, diethylenetriamine trisacrylamide, xylylene bisacrylamide, xylylene bismethacrylamide and the like.

  As another example, the polyisocyanate compound having two or more isocyanate groups in one molecule described in JP-B-48-41708 contains a hydroxyl group represented by the following general formula (A). Examples thereof include a vinyl urethane compound containing two or more polymerizable vinyl groups in one molecule to which a vinyl monomer is added.

_{CH 2 = C (R) COOCH} 2 CH (R ') OH (A)
(However, R and R ′ each independently represent a hydrogen atom or —CH _3. )

  Further, urethane acrylates as described in JP-A-51-37193 and JP-B-2-32293, JP-A-48-64183, JP-B-49-43191, JP-B-52-30490 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. Furthermore, those introduced as photocurable monomers and oligomers in the Japan Adhesive Association, Vol. 20, No. 7, pp. 300 to 308 (1984) can also be used.

  The amount of the ethylenically unsaturated polymerizable compound used is preferably in the range of 5 to 80% by mass, more preferably 30 to 70% by mass, based on the total components constituting the photopolymerizable photosensitive layer.

  In the photopolymerizable photosensitive layer of the photosensitive lithographic printing plate of the present invention, in addition to the above components, various compounds such as a thermal polymerization inhibitor, a colorant, and a plasticizer can be used in combination.

In the present invention, in addition to the above basic components, polymerization is possible during production or storage of a photosensitive composition for forming a photopolymerizable photosensitive layer (hereinafter also referred to as a photopolymerizable composition or simply a composition). It is desirable to add a small amount of a thermal polymerization inhibitor in order to prevent unnecessary thermal polymerization of such an ethylenically unsaturated polymerizable compound. Suitable thermal polymerization inhibitors include haloidroquinone, 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-tert-butylphenol), N-nitrosophenylhydroxylamine cerium salt, N-nitrosophenylhydroxylamine aluminum salt and the like. The addition amount of the thermal polymerization inhibitor is preferably about 0.01% by mass to about 5% by mass with respect to the mass of the whole composition. If necessary, a higher fatty acid derivative such as behenic acid or behenamide is added to prevent polymerization inhibition by oxygen, and it is unevenly distributed on the surface of the photopolymerizable photosensitive layer in the process of drying after coating. May be. The addition amount of the higher fatty acid derivative or the like is preferably about 0.5% by mass to about 10% by mass of the total composition.

  Further, a colorant may be added for the purpose of coloring the photopolymerizable photosensitive layer. Examples of the colorant include phthalocyanine pigments (CIPigment Blue 15: 3, 15: 4, 15: 6, etc.), azo pigments, pigments such as carbon black, titanium oxide, ethyl violet, crystal violet, and azo. There are dyes, anthraquinone dyes, and cyanine dyes. The addition amount of the dye and the pigment is preferably about 0.5% by mass to about 20% by mass of the total composition. In addition, in order to improve the physical properties of the cured film, an additive such as an inorganic filler or a plasticizer such as dioctyl phthalate, dimethyl phthalate, or tricresyl phosphate may be added. These addition amounts are preferably 10% by mass or less of the total composition.

  The photosensitive layer of the photosensitive lithographic printing plate according to the invention is usually formed by dissolving the photosensitive composition in a solvent, and applying and drying the solution on a support described later. Solvents used here include acetone, methyl ethyl ketone, cyclohexane, ethyl acetate, ethylene dichlorite, 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, lactic acid There are ethyl and the like. These solvents can be used alone or in combination. And 1-50 mass% is suitable for the density | concentration of the solid content in a coating solution.

A surfactant can be added to the photopolymerizable composition in the photopolymerizable photosensitive layer of the photosensitive lithographic printing plate in the present invention in order to improve the coating surface quality.
The coverage of the photopolymerizable photosensitive layer is suitably ranges from about 0.1 g / m ² ~ about 10 g / m ² in weight after drying. More preferably from 0.3 to 5 g / m ^2. More preferably, it is 0.5-3 g / m < ² >.

  Further, it is preferable to provide an oxygen-blocking protective layer on the photopolymerizable photosensitive layer in order to prevent the oxygen polymerization inhibiting action. The oxygen barrier protective layer usually contains a water-soluble vinyl polymer. Examples of the water-soluble vinyl polymer contained in the oxygen-blocking protective layer include polyvinyl alcohol and its partial esters, ethers, and acetals, or a substantial amount of unsubstituted vinyl alcohol that makes them necessary water-soluble. Examples thereof include copolymers containing units. Examples of polyvinyl alcohol include those having a hydrolysis degree of 71 to 100% and a polymerization degree of 300 to 2400. Specifically, Kuraray Co., Ltd. PVA-105, PVA-110, PVA-117, PVA-117H, PVA-120, PVA-124, PVA-124H, PVA-CS, PVA-CST, PVA-HC, PVA- 203, PVA-204, PVA-205, PVA-210, PVA-217, PVA-220, PVA-224, PVA-217EE, PVA-217E, PVA-220E, PVA-224E, PVA-405, PVA-420, PVA-613, L-8 etc. are mentioned. Examples of the copolymer include 88-100% hydrolyzed polyvinyl acetate chloroacetate or propionate, polyvinyl formal and polyvinyl acetal, and copolymers thereof. Other useful polymers include polyvinyl pyrrolidone, gelatin and gum arabic, and these may be used alone or in combination.

As the solvent used for coating the oxygen-blocking protective layer in the photosensitive lithographic printing plate of the present invention, pure water is preferable, but alcohols such as methanol and ethanol, and ketones such as acetone and methyl ethyl ketone are mixed with pure water. You may do it. The concentration of the solid content in the coating solvent is suitably 1 to 20% by mass. In the oxygen-blocking protective layer of the present invention, known additives such as a surfactant for improving the coating property and water-soluble plasticity for improving the physical properties of the film may be added. Examples of the water-soluble plasticizer include propionamide, cyclohexanediol, glycerin, sorbitol and the like. Further, a water-soluble (meth) acrylic polymer may be added.
The coating amount of the oxygen barrier protective layer is preferably about 0.1 g / m ² to about 15 g / m ² , more preferably about 1.0 g / m ² to about 5.0 g / m ² in terms of mass after drying. is there.

(Aluminum support)
Next, the aluminum support of the photosensitive lithographic printing plate in the present invention will be described. The aluminum support used in the present invention is dimensionally stable aluminum or an alloy thereof (for example, an alloy with silicon, copper, manganese, magnesium, chromium, zinc, lead, bismuth, nickel), or aluminum or an aluminum alloy. Means a laminated or vapor-deposited plastic film or paper, usually having a thickness of about 0.05 mm to 1 mm, and a composite sheet described in JP-A-48-18327 can also be used.

  The aluminum support in the present invention preferably has a surface roughness Ra of 0.2 to 0.55 μm. In order to obtain such surface roughness, the substrate surface treatment described later is usually performed. Here, the surface roughness of the aluminum support means a center line average roughness (arithmetic average roughness) (Ra) in a direction perpendicular to the aluminum rolling direction. From the roughness curve measured with a stylus meter, When the portion of the measurement length L is extracted in the direction, the center line of this extracted portion is the X axis, the axis perpendicular to the X axis is the Y axis, and the roughness curve is expressed by Y = f (X), it is given by The obtained value is expressed in μm. (The determination of L and the measurement of average roughness are in accordance with JIS B 0601.)

(Graining treatment)
Examples of the graining method include mechanical graining, chemical graining, and electrolytic grain as disclosed in JP-A-56-28893. Furthermore, electrochemical graining method that electrochemically grains in hydrochloric acid or nitric acid electrolyte, and wire brush grain method that scratches aluminum surface with metal wire, and ball grain method that graines aluminum surface with abrasive balls and abrasives Further, a mechanical graining method such as a brush grain method in which the surface is grained with a nylon brush and an abrasive can be used, and the above graining methods can be used alone or in combination. Among them, the electrochemical method of electrochemically graining in hydrochloric acid or nitric acid electrolytic solution is preferred, suitable current density is in the range of ^{100C / dm 2 ~400C / dm 2} . More specifically, in the electrolytic solution containing from 0.1 to 50% by weight hydrochloric acid or nitric acid, the temperature 20 to 100 ° C., for 1 second to 30 minutes, at a current density of 100C / dm ² ~400C / dm ² It is preferable to perform electrolysis.

The grained aluminum support is chemically etched with acid or alkali. When an acid is used as an etching agent, it takes time to destroy the fine structure, which is disadvantageous when the present invention is applied industrially, but it can be improved by using an alkali as the etching agent.
The alkaline agent suitably used in the present invention uses caustic soda, sodium carbonate, sodium aluminate, sodium metasilicate, sodium phosphate, potassium hydroxide, lithium hydroxide, etc., and preferred ranges of concentration and temperature are 1 to 3, respectively. The conditions are 50 mass%, 20 to 100 ° C., and the amount of dissolution of Al is 5 to 20 g / m ³ .

  Pickling is performed to remove dirt (smut) remaining on the surface after etching. The acid used may be treated with nitric acid, sulfuric acid, phosphoric acid, chromic acid, hydrofluoric acid, or borofluoride. In particular, as a method for removing smut after the electrochemical surface roughening treatment, contact with 15 to 65 mass% sulfuric acid at a temperature of 50 to 90 ° C. as described in JP-A-53-12739 is preferable. And the alkali etching method described in Japanese Patent Publication No. 48-28123.

(Anodizing treatment)
The aluminum support treated as described above is preferably further subjected to an anodizing treatment. The anodizing treatment can be performed by a method conventionally used in this field. Specifically, when a direct current or an alternating current is applied to aluminum in an aqueous solution or non-aqueous solution by combining sulfuric acid, phosphoric acid, chromic acid, oxalic acid, sulfamic acid, benzenesulfonic acid, etc. An anodized film can be formed.
The conditions of the anodizing treatment cannot be determined unconditionally because they vary depending on the electrolytic solution used. In general, the concentration of the electrolytic solution is 1 to 80% by mass, the liquid temperature is 5 to 70 ° C., and the current density is 0. The range of 5 to 60 amperes / dm ² , voltage of 1 to 100 V, and electrolysis time of 10 to 100 seconds is appropriate.

Among these anodizing treatments, the method of anodizing at a high current density in sulfuric acid and the phosphoric acid described in U.S. Pat.No. 3,511,661 described in British Patent 1,412,768 in particular. A method of anodizing as a bath is preferred.
In the present invention, the anodized film is preferably 1 to 10 g / m ^2, by a 1 g / m ² or more, can be hard to contain the wound to the plate, and 10 g / m ² or less This eliminates the need for a large amount of electric power during production, which is economically advantageous. More preferably 1.5~7g / m ^2. More preferably 2-5 g / m ^2.

Furthermore, in the present invention, the aluminum support may be subjected to sealing treatment after graining treatment and anodizing. Such sealing treatment is performed by immersing the substrate in a hot aqueous solution containing hot water and an inorganic salt or an organic salt, and a water vapor bath. Further, the aluminum support in the present invention may be subjected to a surface treatment such as a silicate treatment with an alkali metal silicate, an immersion treatment in an aqueous solution of potassium fluoride zirconate, phosphate or the like.
The photosensitive lithographic printing plate of the present invention is produced by forming a photopolymerizable photosensitive layer comprising the photopolymerizable composition on the aluminum support that has been surface-treated as described above. Before coating the photosensitive layer, an organic or inorganic undercoat layer (intermediate layer) may be provided as necessary.

  Next, a method for making a lithographic printing plate using the photosensitive lithographic printing plate of the present invention will be described in detail. The photosensitive lithographic printing plate described above is preferably developed with an aqueous alkaline solution after image exposure. Below, the developing solution used for the plate making method of this invention is demonstrated.

(Developer)
The developer used in the plate making method of the photosensitive lithographic printing plate according to the present invention is not particularly limited, and for example, a developer containing an inorganic alkali salt and a surfactant and having a pH of 11.0 to 12.7. Preferably used.

  The inorganic alkali salt can be used as appropriate. For example, sodium hydroxide, potassium, ammonium, lithium, sodium silicate, potassium, ammonium, lithium, tribasic sodium phosphate, potassium, Examples thereof include inorganic alkaline agents such as ammonium, sodium carbonate, potassium, ammonium, sodium hydrogen carbonate, potassium, ammonium, sodium borate, potassium, and ammonium. These may be used alone or in combination of two or more.

When silicate is used, developability can be achieved by adjusting the mixing ratio and concentration of silicon oxide SiO ₂ , which is a component of silicate, and alkali oxide M ₂ O (M represents an alkali metal or ammonium group). Can be easily adjusted. Among the alkaline aqueous solutions, those having a mixing ratio (SiO ₂ / M ₂ O: molar ratio) of the silicon oxide SiO ₂ and the alkali oxide M ₂ O of 0.5 to 3.0 are preferable, and 1.0 to 2 0.0 is more preferable. The concentration of the silicate in the alkaline aqueous solution is preferably 1 to 10% by mass, more preferably 3 to 8% by mass, and particularly preferably 4 to 7% by mass. When the concentration is within the above range, there is no decrease in developability and processing capability, no precipitation or crystal formation, no gelation during neutralization during waste liquid, and no trouble in waste liquid processing.

  Further, an organic alkali agent may be supplementarily used for the purpose of delicate adjustment of the alkali concentration and assisting the solubility of the photosensitive layer. Examples of the organic alkali agent include monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, Examples thereof include diisopropanolamine, ethyleneimine, ethylenediamine, pyridine, tetramethylammonium hydroxide and the like. These alkali agents are used alone or in combination of two or more.

  Surfactant can be used as appropriate, for example, nonionic surfactant having a polyoxyalkylene ether group, polyoxyethylene alkyl esters such as polyoxyethylene stearate, sorbitan monolaurate, sorbitan monostearate, Nonionic surfactants such as sorbitan alkyl esters such as sorbitan distearate, sorbitan monooleate, sorbitan sesquioleate, sorbitan trioleate, monoglyceride alkyl esters such as glycerol monostearate and glycerol monooleate; dodecylbenzenesulfonic acid Alkylbenzene sulfonates such as sodium, sodium butyl naphthalene sulfonate, sodium pentyl naphthalene sulfonate, sodium hexyl naphthalene sulfonate , Anionic surface activity of alkyl naphthalenes sulfonates such as sodium octyl naphthalene sulfonate, alkyl sulfonates such as sodium lauryl sulfate, alkyl sulfonates such as sodium dodecyl sulfonate, sulfosuccinate esters such as sodium dilauryl sulfosuccinate Agents: Examples include alkylbetaines such as lauryl betaine and stearyl betaine, and amphoteric surfactants such as amino acids. Particularly preferred are nonionic surfactants having a polyoxyalkylene ether group.

  As the surfactant having a polyoxyalkylene ether group, those having the structure of the following general formula (I) are preferably used.

R ⁴⁰ —O— (R ⁴¹ —O) _pH (I)

In the formula, R ⁴⁰ has an alkyl group having 3 to 15 carbon atoms which may have a substituent, an aromatic hydrocarbon group having 6 to 15 carbon atoms which may have a substituent, or a substituent. A heteroaromatic cyclic group having 4 to 15 carbon atoms (wherein the substituent is an alkyl group having 1 to 20 carbon atoms, a halogen atom such as Br, Cl or I, or an aromatic hydrocarbon having 6 to 15 carbon atoms) R ⁴¹ is a group, an aralkyl group having 7 to 17 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkoxy-carbonyl group having 2 to 20 carbon atoms, or an acyl group having 2 to 15 carbon atoms. , An optionally substituted alkylene group having 1 to 100 carbon atoms (in addition, examples of the substituent include an alkyl group having 1 to 20 carbon atoms and an aromatic hydrocarbon group having 6 to 15 carbon atoms). P represents an integer of 1 to 100.

  In the definition of the above formula (I), specific examples of the “aromatic hydrocarbon group” include phenyl group, tolyl group, naphthyl group, anthryl group, biphenyl group, phenanthryl group, etc. Specific examples of the “group” include furyl group, thionyl group, oxazolyl group, imidazolyl group, pyranyl group, pyridinyl group, acridinyl group, benzofuranyl group, benzothionyl group, benzopyranyl group, benzooxazolyl group, benzoimidazolyl group, and the like. It is done.

In addition, the part of (R ⁴¹ —O) _p in formula (I) may be two or three kinds of groups as long as it is in the above range. Specific examples include a combination of random or block combinations of ethyleneoxy and propyleneoxy, ethyleneoxy and isopropyloxy, ethyleneoxy and butyleneoxy, ethyleneoxy and isobutylene, and the like. . In the present invention, the surfactant having a polyoxyalkylene ether group is used alone or in combination, and it is effective to add 1 to 30% by mass, preferably 2 to 20% by mass in the developer. By setting the addition amount to 1 to 30% by mass, it is possible to reduce deterioration in developability, damage during development, decrease in printing durability of the printing plate, and the like.

  Examples of the nonionic surfactant having a polyoxyalkylene ether group represented by the above formula (I) include polyoxyethylene alkyl such as polyoxyethylene lauryl ether, polyoxyethylene cetyl ether and polyoxyethylene stearyl ether. Polyoxyethylene alkyl aryls such as ethers, polyoxyethylene phenyl ethers, polyoxyethylene aryl ethers such as polyoxyethylene naphthyl ethers, polyoxyethylene methyl phenyl ethers, polyoxyethylene octyl phenyl ethers, polyoxyethylene nonyl phenyl ethers, etc. And ethers.

  These surfactants can be used alone or in combination.

  The pH of the developer used in the plate making method of the present invention is preferably 11.0 to 12.7, more preferably 11.5 to 12.5. By setting the pH to 11.0 to 12.7, image formation is improved, over-development is prevented, and damage to the exposed area during development can be reduced.

  The conductivity of the developer used in the present invention is preferably 3 to 30 mS / cm. By setting the electrical conductivity to 3 to 30 mS / cm, the elution rate of the photosensitive layer on the surface of the aluminum plate support can be appropriately adjusted, and the remaining film is prevented from being generated in the unexposed area and preventing the stain. be able to. Particularly preferred conductivity is in the range of 5-20 mS / cm.

(Exposure and development processing)
The photosensitive lithographic printing plate in the present invention is, for example, a carbon arc lamp, a high-pressure mercury lamp, a xenon lamp, a metal halide lamp, a fluorescent lamp, a tungsten lamp, a halogen lamp, a helium cadmium laser, an argon ion laser, an FD / YAG laser, a helium neolaser. An image can be formed on the surface of the aluminum plate support by exposing the image with a conventionally known actinic ray such as a semiconductor laser (350 nm to 600 nm) and then developing it. In order to increase the curing rate of the photopolymerizable photosensitive layer after image exposure and before development, a heating process may be performed at a temperature of 50 ° C. to 140 ° C. for 1 second to 5 minutes. When the heating temperature is within the above range, there is an effect of increasing the curing rate, and no residual film is formed due to dark polymerization in the unexposed area.

  Further, as described above, when the oxygen blocking layer is provided on the photosensitive layer of the photosensitive lithographic printing plate in the present invention, the removal of the oxygen blocking layer and the photopolymerizable photosensitive layer are carried out using a developer. A method of simultaneously removing the unexposed portion or a method of removing the oxygen blocking layer first with water and warm water and then removing the photopolymerizable photosensitive layer of the unexposed portion with a developer is used. These water or warm water can contain a preservative described in JP-A-10-10754, an organic solvent described in JP-A-8-278636, and the like.

  The development of the photosensitive lithographic printing plate according to the present invention with the developer is performed at a temperature of usually 0 to 60 ° C., preferably 15 to 40 ° C. according to a conventional method, for example, using the exposed lithographic printing plate as a developer. It is performed by dipping and rubbing with a brush.

Further, when developing using an automatic developing machine, the developing solution becomes fatigued according to the amount of processing, so that the processing capability may be restored using a replenishing solution or a fresh developing solution.
The photosensitive lithographic printing plate thus developed is usually washed with water as described in JP-A Nos. 54-8002, 55-11545, 59-58431, and the like. And post-treatment with a desensitizing solution containing a rinsing solution containing a surfactant and the like, gum arabic, starch derivatives and the like. In the present invention, these treatments can be used in various combinations for the post-treatment of the photosensitive lithographic printing plate.
The printing plate obtained by the above treatment can be improved in printing durability by post-exposure treatment or heating treatment such as burning according to the method described in JP-A-2000-89478.
The planographic printing plate obtained by such processing is loaded on an offset printing machine and used for printing a large number of sheets.

  Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto.

[Example 1]
(Creation of aluminum support)
An aluminum plate having a thickness of 0.3 mm was etched by being immersed in 10% by mass sodium hydroxide at 60 ° C. for 25 seconds, washed with running water, neutralized with a 20% by mass nitric acid aqueous solution, and then washed with water. This was subjected to an electrolytic surface roughening treatment in a 1% by mass nitric acid aqueous solution using a sinusoidal alternating waveform current at an anode time electricity of 300 coulomb / dm ² . Subsequently, after being immersed in a 1% by weight aqueous sodium hydroxide solution at 40 ° C. for 5 seconds and then immersed in a 30% by weight sulfuric acid aqueous solution and desmutted at 60 ° C. for 40 seconds, the current density in a 20% by weight sulfuric acid aqueous solution was 2A / current density. At dm ² , the anodization treatment was performed for 2 minutes so that the thickness of the anodized film was 2.7 g / m ² . When the surface roughness was measured, it was 0.3 μm (Ra display according to JIS B0601).

(Coating intermediate layer)
Next, an intermediate layer coating solution having the following composition was applied to the aluminum support with a wire bar, and dried at 90 ° C. for 30 seconds using a warm air dryer. The coating amount after drying was 10 mg / m ² .

<Intermediate layer coating solution>
0.1 g of a copolymer of ethyl methacrylate and 2-acrylamido-2-methyl-1-propanesulfonic acid sodium salt in a molar ratio of 75:25
2-Aminoethylphosphonic acid 0.1g
50g of methanol
Ion exchange water 50g

(Coating of photosensitive layer)
A photosensitive layer coating solution having the following composition was prepared, applied on the intermediate layer with a wheeler so that the film thickness after drying was 1.4 g / m ^2, and dried at 100 ° C. for 1 minute.

<Photosensitive layer coating solution>
Ethylenically unsaturated polymerizable compound: compound of the following formula 1 1.5 g
Polymer compound: 2.0 g of exemplary compound A-1
Sensitizing dye: 0.1 g of the compound of formula 2 below
Photopolymerization initiator: 0.2 g of the compound of the following formula 3
Co-sensitizer: Compound of the following formula 4 0.2 g
Color pigment dispersion (composition below) 2.0g
Thermal polymerization inhibitor: N-nitrophenyl hydroxyl 0.01 g
Amine aluminum salt Surfactant: Megafac F176, 0.02g
Dainippon Ink & Chemicals, Inc. Methyl ethyl ketone 20.0g
Propylene glycol monomethyl ether 20.0g

<Composition of colored pigment dispersion>
Pigment Blue 15: 6 15 parts by mass Allyl methacrylate / methacrylic acid copolymer 10 parts by mass (copolymerization molar ratio 83/17)
Cyclohexanone 15 parts by mass Methoxypropyl acetate 20 parts by mass Propylene glycol monomethyl ether 40 parts by mass

(Coating of oxygen barrier protective layer)
On this photosensitive layer, a 3% by weight aqueous solution of polyvinyl alcohol (saponification degree 78 mol%, polymerization degree 550) was applied so that the dry coating weight was 2 g / m ^2, and dried at 100 ° C. for 2 minutes to obtain oxygen. A blocking protective layer was applied to prepare a photosensitive lithographic printing plate.

[Examples 2 to 10]
A photosensitive lithographic printing plate was prepared in the same manner as in Example 1 except that the polymer compound in the photosensitive layer coating solution of Example 1 was changed to the polymer compound shown in Table 1.

[Examples 11 to 16]
Photosensitive in the same manner as in Example 1 except that the ethylenically unsaturated polymerizable compound, sensitizing dye, photopolymerization initiator, and co-sensitizer in the photosensitive layer coating solution of Example 1 were changed to those shown in Table 2. A sex lithographic printing plate was prepared.

Example 17
A photosensitive lithographic printing plate was prepared in the same manner as in Example 1 except that the aluminum support in Example 1 was changed to the following aluminum support.

(Creation of aluminum support)
Using a JIS A1050 aluminum plate having a thickness of 0.24 mm and a width of 1030 mm, the treatment was continuously performed as follows.
(A) Roller-type nylon that rotates using an existing mechanical roughening device while supplying a slurry of a specific gravity of 1.12 (pumice) and water as a polishing slurry to the surface of an aluminum plate Mechanical roughening was performed with a brush. The average particle size of the abrasive was 40 to 45 μm, and the maximum particle size was 200 μm. The material of the nylon brush was 6.10 nylon, the hair length was 50 mm, and the hair diameter was 0.3 mm. The nylon brush was planted so as to be dense by making a hole in a stainless steel tube having a diameter of 300 mm. Three rotating brushes were used. The distance between the two support rollers (φ200 mm) at the bottom of the brush was 300 mm. The brush roller was pressed until the load of the drive motor that rotates the brush was 7 kW plus the load before the brush roller was pressed against the aluminum plate. The rotation direction of the brush was the same as the movement direction of the aluminum plate, and the rotation speed was 200 rpm.
(B) The aluminum plate was subjected to an etching process by spraying at a temperature of 70 ° C. in an aqueous solution having a caustic soda concentration of 2.6 mass% and an aluminum ion concentration of 6.5 mass% to dissolve the aluminum plate by 0.3 g / m ² . Thereafter, washing with water was performed by spraying.
(C) A desmut treatment was performed by spraying with a 1% by mass aqueous solution of nitric acid having a temperature of 30 ° C. (including 0.5% by mass of aluminum ions), and then washed with water by spraying. The nitric acid aqueous solution used for the desmut was the waste liquid from the step of electrochemical surface roughening using alternating current in nitric acid aqueous solution.

(D) An electrochemical surface roughening treatment was continuously performed using an alternating voltage of 60 Hz. The electrolytic solution at this time was a 1% by mass aqueous nitric acid solution (including 0.5% by mass aluminum ions and 0.007% by mass ammonium ions) at a temperature of 40 ° C. The AC power source was subjected to an electrochemical surface roughening treatment using a carbon electrode as a counter electrode using a trapezoidal rectangular wave alternating current with a time TP of 2 msec until the current value reached a peak from zero and a duty ratio of 1: 1. Ferrite was used for the auxiliary anode. The current density was 30 A / dm ² at the current peak value, and the amount of electricity was 255 C / cm ² in terms of the total amount of electricity when the aluminum plate was the anode. 5% of the current flowing from the power source was shunted to the auxiliary anode. Then, water washing by spraying was performed.
(E) The aluminum plate was etched by spraying with an aqueous solution having a caustic soda concentration of 26% by mass and an aluminum ion concentration of 6.5% by mass at 32 ° C., and the aluminum plate was dissolved by 0.2 g / m ² , and the previous stage AC was used. The removal of the smut component mainly composed of aluminum hydroxide produced during electrochemical surface roughening and the edge part of the produced pit were dissolved to smooth the edge part. Then, it was washed with water with a spray.
(F) A desmut treatment by spraying was performed with a 25% by weight aqueous solution of nitric acid at a temperature of 60 ° C. (including 0.5% by weight of aluminum ions), followed by washing with water by spraying.

(G) An anodizing apparatus of an existing two-stage feed electrolytic treatment method (first and second electrolysis part length 6 m, first feed part length 3 m, second feed part length 3 m, first and second feed electrode lengths 2.4 m each ) Was used to perform anodization at a sulfuric acid concentration of 170 g / liter (containing 0.5 mass% of aluminum ions) at a temperature of 38 ° C. Thereafter, washing with water was performed by spraying. At this time, in the anodizing device, the current from the power source flows to the first power supply electrode provided in the first power supply unit, flows to the plate-like aluminum via the electrolytic solution, An oxide film is formed on the surface, passes through the electrolytic electrode provided in the first power feeding portion, and returns to the power source. On the other hand, the current from the power source flows to the second power feeding electrode provided in the second power feeding portion, similarly flows to the plate-like aluminum via the electrolytic solution, and an oxide film is formed on the surface of the plate-like aluminum by the second electrolysis portion. Although the amount of electricity fed from the power source to the first feeding unit and the amount of electricity fed from the power source to the second feeding unit are the same, the feeding current density on the oxide film surface in the second feeding unit is about It was 25 A / dm ² . In the 2nd electric power feeding part, it came to feed from the oxide film surface of 1.35 g / m < ² >. The final oxidation treatment was 2.7 g / m ² .

[Comparative Examples 1-3]
A lithographic printing plate precursor was prepared in the same manner as in Example 1 except that the polymer compound in the photosensitive layer coating solution of Example 1 was changed to the polymer compound shown in Table 3.

  The photosensitive lithographic printing plates of Examples 1 to 17 and Comparative Examples 1 to 3 were exposed, developed / engraved by the following methods, and evaluated for sensitivity, halftone dot uniformity, and stability over time.

(sensitivity)
After storing the photosensitive lithographic printing plate at room temperature (about 25 ° C) for 3 days, a gray scale is pasted on the plate surface so that the light intensity changes by 1 / √2 and a violet laser of 30 mW is installed. Using a plate setter Vx9600CTP manufactured by Fuji Film Electroimaging Co., Ltd., the entire surface was exposed by adjusting the amount of light so that the amount of light on the plate surface was 0.1 mJ / cm ² . Subsequently, development / plate making was performed as follows. The higher the gray scale level reproduced on the planographic printing plate, the higher the sensitivity.
(Halftone dot uniformity)
After the photosensitive lithographic printing plate was stored at room temperature (about 25 ° C.) for 3 days, the amount of light on the plate surface was set to 0. 0 using a plate setter Vx9600CTP manufactured by Fuji Film Electro Imaging Co., Ltd. equipped with a violet laser of 30 mW. The amount of light was adjusted so as to be 1 mJ / cm ² , and a 200-line 50% flat screen image was printed on the entire plate surface. Subsequently, development / plate making was performed as follows. The halftone dot area on the planographic printing plate was measured at nine locations, and the average value and the difference between the maximum and minimum values were determined. The higher the average value of the halftone dot area, the higher the sensitivity, and the smaller the difference between the maximum value and the minimum value, the higher the halftone dot uniformity.

(Stability over time)
The photosensitive lithographic printing plate was stored in a thermocell box at 60 ° C. for 3 days, and then exposed, developed / plate-formed in the same manner as described above, and the sensitivity and halftone dot uniformity were evaluated. A result is compared with what was stored at 25 degreeC for 3 days (Fr), and the smaller the difference, the higher the stability over time.

(Development / plate making)
Fuji Photo Film Co., Ltd. automatic processor LP-850P2 (preheat temperature is 100 ° C.) was charged with a developer having the following composition and Fuji Photo Film Co., Ltd. finisher FP-2W, respectively, with a developer temperature of 30 ° C. and a development time. The exposed photosensitive lithographic printing plate was developed / engraved for 18 seconds to obtain a lithographic printing plate.

<Developer: pH 11.6>
Sodium hydroxide 0.15 parts by mass The following compound (a) 5.0 parts by mass Ethylenediaminetetraacetic acid / 4Na salt 0.1 parts by mass Water 94.75 parts by mass

  The results are shown in Table 4.

  From the results shown in Table 4, it can be seen that Examples 1 to 17 have higher sensitivity than those of Comparative Examples 1 to 3, and are excellent in halftone dot uniformity and stability over time.

Example 21
Preparation of the aluminum support and coating of the intermediate layer were performed in the same manner as in Example 1.

(Coating of photosensitive layer)
A photosensitive layer coating solution having the following composition was prepared, applied on the intermediate layer with a wheeler so that the film thickness after drying was 1.5 g / m ^2, and dried at 100 ° C. for 1 minute.

(Photosensitive layer coating solution)
Ethylenically unsaturated polymerizable compound: compound of the following formula 1 1.5 g
Polymer compound: compound of the following formula 2 (molecular weight Mw: 53,000, 2.0 g
Acid value: 1.1, C = C amount: 1.9 mmol)
Sensitizing dye: 0.1 g of the compound of formula 3 below
Photopolymerization initiator: 0.2 g of the compound of the following formula 4
Co-sensitizer: Compound of the following formula 5 0.2 g
Color pigment dispersion (composition below) 2.0g
Thermal polymerization inhibitor: N-nitrosophenyl hydroxyl 0.01 g
Amine aluminum salt Surfactant: Megafac F176, 0.02g
Dainippon Ink & Chemicals, Inc. Methyl ethyl ketone 20.0g
Propylene glycol monomethyl ether 20.0g

<Composition of colored pigment dispersion>
Pigment Blue 15: 6 15 parts by mass Allyl methacrylate / methacrylic acid copolymer 10 parts by mass (copolymerization molar ratio 83/17)
Cyclohexanone 15 parts by mass Methoxypropyl acetate 20 parts by mass Propylene glycol monomethyl ether 40 parts by mass

(Coating of oxygen barrier protective layer)
On this photosensitive layer, a 3% by weight aqueous solution of polyvinyl alcohol (saponification degree 98 mol%, polymerization degree 550) was applied so that the dry coating weight was 2 g / m ^2, and dried at 100 ° C. for 2 minutes. An oxygen barrier protective layer was applied to prepare a photosensitive lithographic printing plate.

[Examples 22 to 30]
A photosensitive lithographic printing plate was prepared in the same manner as in Example 21 except that the polymer compound in the photosensitive layer coating solution of Example 21 was changed to the polymer compound shown in Table 5.

[Examples 31 to 36]
Photosensitizing in the same manner as in Example 21, except that the ethylenically unsaturated polymerizable compound, sensitizing dye, photopolymerization initiator, and cosensitizer in the photosensitive layer coating solution of Example 21 were changed to those shown in Table 6. A sex lithographic printing plate was prepared.

Example 37
A photosensitive lithographic printing plate was prepared in the same manner as in Example 21 except that the aluminum support in Example 21 was changed to the aluminum support in Example 17.

Example 38
A photosensitive lithographic printing plate was prepared in the same manner as in Example 21 except that the intermediate layer of Example 21 was changed to the following intermediate layer.
(Coating intermediate layer)
The following intermediate layer sol composition was weighed in a beaker and stirred at 25 ° C. for 20 minutes.

<Intermediate layer sol solution composition>
Tetraethoxysilane 38g
3-Methacryloxypropyltrimethoxysilane 13g
85% phosphoric acid aqueous solution 12g
Ion exchange water 15g
Methanol 100g

The above solution was transferred to a three-necked flask, a reflux condenser was attached, and the three-necked flask was immersed in an oil bath at room temperature. While stirring the contents of the three-necked flask with a magnetic stirrer, the temperature was raised to 50 ° C. over 30 minutes. While maintaining the bath temperature at 50 ° C., the mixture was further reacted for 1 hour to obtain a sol solution. This sol solution was diluted with methanol / ethylene glycol = 20/1 (mass ratio) to 0.5% by mass, coated on the aluminum support with a wheeler, and dried at 100 ° C. for 1 minute. The coating amount at that time was 3.5 mg / m ² . This coating amount was obtained by obtaining the amount of Si element by fluorescent X-ray analysis and using it as the coating amount.

[Comparative Examples 4 to 7]
A photosensitive lithographic printing plate was prepared in the same manner as in Example 21 except that the polymer compound in the photosensitive layer coating solution of Example 21 was changed to the polymer compound shown in Table 7 below.

  Using the photosensitive lithographic printing plates of Examples 21 to 38 and Comparative Examples 4 to 7, sensitivity and halftone dot uniformity were evaluated in the same manner as in Examples 1 to 17 and Comparative Examples 1 to 3. . In addition, the stability over time was evaluated in the same manner as in Examples 1 to 17 and Comparative Examples 1 to 3 using a photosensitive lithographic printing plate stored in a thermocell box at 60 ° C. for 3 days after production.

  The results are shown in Table 8.

  From the results shown in Table 8, it is clear that Examples 21 to 38 have higher sensitivity and superior halftone dot uniformity and stability over time as compared with Comparative Examples 4 to 7.

Claims (5)

On the aluminum support, the structural unit (i) having a carbon-carbon double bond in the side chain, the structural unit (ii) having an acid group, and the structural units shown below (a) to (c) are selected. A photosensitive lithographic printing plate comprising a photopolymerizable photosensitive layer containing a polymer compound having at least one structural unit (iii).
(A) Structural unit having an ethyleneoxy group (b) Structural unit having a cyclohexyl group (c) Structural unit having two or more hydroxyl groups   The polymer compound is a polymer compound having a carbon-carbon double bond amount in the range of 0.2 to 2.3 mmol per 1 g mass and an acid value in the range of 0.5 to 2.0. The photosensitive lithographic printing plate according to claim 1, wherein the photosensitive lithographic printing plate is present.   3. The photosensitive lithographic printing plate according to claim 1, wherein the photopolymerizable photosensitive layer further contains a photopolymerization initiator and an ethylenically unsaturated polymerizable compound.   The photosensitive lithographic printing plate according to claim 3, wherein the photopolymerization initiator is a hexaarylbisimidazole compound.   The photosensitive lithographic printing plate according to any one of claims 1 to 4, wherein an oxygen-blocking protective layer is provided on the photopolymerizable photosensitive layer.