JP2007256537A - Photosensitive lithographic printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive lithographic printing plate for an infrared laser which excels in printing durability and satisfies both of chemical resistance and scratch resistance. <P>SOLUTION: The photosensitive lithographic printing plate for an infrared laser is obtained by disposing a photosensitive layer containing at least a high molecular compound and an infrared absorbent on a hydrophilic surface of a support having the hydrophilic surface, wherein the photosensitive layer further contains an onium salt having a melting point of ≤80°C and contains at least a vinyl polymer as the high molecular compound which the photosensitive layer contains. The vinyl polymer comprises at least one of specific three constitutional units. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a photosensitive lithographic printing plate, and more particularly to a so-called direct lithographic printing plate capable of direct plate making by scanning with an infrared laser beam based on a digital signal output from a computer or the like.

  In recent years, the development of lasers has been remarkable. In particular, solid-state lasers and semiconductor lasers having a light emitting region from the near infrared to the infrared region have been increasing in output and miniaturized. Therefore, these lasers are very useful as an exposure light source when directly making a plate from digital data output from a computer or the like.

  An example of a lithographic printing plate material for infrared laser that uses an infrared laser having a light emitting region from near infrared to infrared as an exposure light source is an essential component of a binder resin and an IR dye that absorbs light and generates heat. Is a planographic printing plate material. When the infrared laser is exposed to the lithographic printing plate material for infrared laser, for example, in the case of a positive type, the IR dye or the like in the lithographic printing plate material for infrared laser in the unexposed portion (image portion) It acts as a dissolution inhibitor that substantially lowers the solubility of the binder resin by interaction. On the other hand, in the exposed portion (non-image portion), the IR dye or the like absorbs light and generates heat, so that the interaction between the IR dye or the like and the binder resin is weakened. Therefore, at the time of development, the exposed portion (non-image portion) is dissolved in an alkaline developer, and a lithographic printing plate is formed.

  In such a lithographic printing plate material for infrared laser, improvement in chemical resistance and improvement in scratch resistance are cited as technical problems. Among these, for improving chemical resistance, for example, it has been proposed to use polyvinyl acetal (see, for example, Patent Document 1), but it is insufficient from the viewpoint of compatibility with scratch resistance. Further, it is considered that making the structure of the resin layer of the lithographic printing plate into two or more layers is useful for achieving both chemical resistance and scratch resistance. For example, a polymer compound having a maleimide compound as a constituent unit in the lower layer is used. Although it has been proposed to use it (see, for example, Patent Document 2), further level-up has been desired.

US Patent Application Publication No. 2004/0020484 US Patent Application Publication No. 2004/0067432

  An object of the present invention is to provide a photosensitive lithographic printing plate for an infrared laser which is excellent in printing durability and has both chemical resistance and scratch resistance.

As a result of diligent research, the inventor of the present invention has the object described above as the photosensitive laser lithographic printing plate precursor for infrared laser described in the following 1) or 2) (hereinafter simply referred to as “photosensitive lithographic printing plate for infrared laser”). )).
The present invention firstly relates to a photosensitive lithographic printing plate for infrared laser as described in 1) below.
1) A photosensitive lithographic printing plate for infrared laser in which a photosensitive layer containing at least a polymer compound and an infrared absorber is provided on the hydrophilic surface of a support having a hydrophilic surface, the photosensitive layer comprising: Further, it contains an onium salt having a melting point of 80 ° C. or lower, and contains at least a vinyl polymer as a polymer compound contained in the photosensitive layer. The vinyl polymer is composed of the following (A), (B) and ( A photosensitive lithographic printing plate for infrared lasers, comprising at least one selected from the group consisting of C) as a constituent unit;
(A) A structural unit derived from a monomer in which a saturated cyclic group containing a carbonyl group as a ring constituent group is directly bonded to a vinyl group, and the cyclic group may have a hetero atom as a ring constituent atom.
(B) a structural unit derived from a monomer in which an unsaturated cyclic group containing at least one nitrogen atom as a ring constituent atom is directly bonded to a vinyl group, wherein the cyclic group contains one of the nitrogen atoms as C—N ═C bond.
(C) A structural unit derived from vinyl acetals.

The present invention secondly relates to a photosensitive lithographic printing plate for infrared laser as described in 2) below.
2) On the hydrophilic surface of the support having a hydrophilic surface, a lower layer containing at least a polymer compound and an infrared absorber, and at least another polymer compound different from the lower layer polymer compound is contained. A photosensitive lithographic printing plate for infrared laser having at least an upper layer in this order, the upper layer further containing an onium salt having a melting point of 80 ° C. or lower, and at least a vinyl polymer as a polymer compound contained in the lower layer A photosensitive lithographic printing for infrared lasers, wherein the vinyl polymer comprises at least one selected from the group consisting of (A), (B) and (C) as a constituent unit Edition.

  The photosensitive lithographic printing plate of the present invention is excellent in all of printing durability, chemical resistance and scratch resistance.

The 1st side surface of the photosensitive lithographic printing plate for infrared lasers of this invention is demonstrated.
The photosensitive lithographic printing plate for infrared laser of the present invention is a photosensitive for infrared laser in which a photosensitive layer containing at least a polymer compound and an infrared absorber is provided on the hydrophilic surface of a support having a hydrophilic surface. In the lithographic printing plate, the photosensitive layer further contains an onium salt having a melting point of 20 ° C. or lower, and contains at least a vinyl polymer as a polymer compound contained in the photosensitive layer. A structural unit is at least one selected from the group consisting of A), (B) and (C).
(A) A structural unit derived from a monomer in which a saturated cyclic group containing a carbonyl group as a ring constituent group is directly bonded to a vinyl group, and the cyclic group may have a hetero atom as a ring constituent atom.
(B) a structural unit derived from a monomer in which an unsaturated cyclic group containing at least one nitrogen atom as a ring constituent atom is directly bonded to a vinyl group, wherein the cyclic group contains one of the nitrogen atoms as C—N ═C bond.
(C) A structural unit derived from vinyl acetals.

The 2nd side surface of the photosensitive lithographic printing plate for infrared lasers of this invention is demonstrated.
The photosensitive lithographic printing plate for infrared laser of the present invention comprises at least a polymer compound and an infrared absorber on the hydrophilic surface of the photosensitive lithographic printing plate for infrared laser and a support having a hydrophilic surface. In the photosensitive lithographic printing plate for infrared laser having at least this order, and an upper layer containing at least another polymer compound different from the polymer compound in the lower layer, the upper layer further has a melting point of 20 ° C. or lower. An onium salt is included, and at least a vinyl polymer is contained as a polymer compound contained in the lower layer, and the vinyl polymer is selected from the group consisting of the above (A), (B), and (C). It is characterized in that at least one is a structural unit.

The operation of the present invention is estimated as follows. However, the authenticity does not affect the patentability of the present invention. An onium salt having a melting point of 80 ° C. or less and a polymer compound having a specific structure have an interaction, and the interaction occurs in the film in the case of a single layer, and in the interface in the case of multiple layers, This is thought to be because the strength of the entire coating film has increased. Further, since the melting point of the onium salt is 80 ° C. or less, there is no concern of residue deposition during development.
Hereinafter, the constituent components of the planographic printing plate of the present invention will be described sequentially.

[Onium salt with a melting point of 80 ° C. or lower]
The onium salt having a melting point of 80 ° C. or lower used in the present invention is composed of a combination of an organic cation and an organic or inorganic anion. The onium salt used in the present invention preferably has a melting point of 50 ° C. or lower, more preferably 20 ° C. or lower, and the lower limit is preferably −120 ° C. or higher, more preferably −90 ° C. or higher.
Examples of the organic cation include an imidazolium cation, a pyridinium cation, a pyrrololidinium cation, a phosphonium cation, and a tetraalkylammonium cation. Examples of the anion include methyl sulfonate, trifluoromethyl sulfonate, bromide, chloride, nitrate, tetrafluoroborate, hexafluorophosphate, and methyl sulfate.
As an anion, tetrafluoroborate is preferable because it tends to lower the melting point.
Use of an onium salt having a low melting point is advantageous because compatibility is improved in addition to the absence of residue precipitation.

  Examples of such onium salts include 1-ethyl-3-methylimidazolium bromide, 1-ethyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium nitrate, 1-ethyl-3-methylimidazole. Rium tetrafluoroborate, 1-ethyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium trifluoromethylsulfonate, 1-ethyl-2,3-dimethylimidazolium bromide, 1-ethyl-2 , 3-Dimethylimidazolium chloride, 1-ethyl-2,3-dimethylimidazolium nitrate, 1-ethyl-2,3-dimethylimidazolium tetrafluoroborate, 1-ethyl-2,3-dimethylimidazolium hexafluoro Phosphate, 1 Butyl-3-methylimidazolium bromide, 1-butyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium nitrate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3 -Methylimidazolium hexafluorophosphate, 1-hexyl-3-methylimidazolium bromide, 1-hexyl-3-methylimidazolium chloride, 1-hexyl-3-methylimidazolium nitrate, 1-hexyl-3-methylimidazole Lithium tetrafluoroborate, 1-hexyl-3-methylimidazolium hexafluorophosphate, 1-octyl-3-methylimidazolium bromide, 1-octyl-3-methylimidazolium chloride, 1-octyl-3-methyl Louis imidazolium nitrate, 1-octyl-3-methylimidazolium tetrafluoroborate, 1-octyl-3-methylimidazolium hexafluorophosphate, 1-methyl-3-octylimidazolium bromide, 1-methyl-3-octyl Imidazolium chloride, 1-methyl-3-octylimidazolium nitrate, 1-methyl-3-octylimidazolium tetrafluoroborate, 1-methyl-3-octylimidazolium hexafluorophosphate, 1-butyl-4-methylpyridinium Bromide, 1-butyl-4-methylpyridinium chloride, 1-butyl-4-methylpyridinium nitrate, 1-butyl-4-methylpyridinium tetrafluoroborate, 1-butyl-4-methylpyridinium Exemplified as xafluorophosphate, 1-butyl-3-methylimidazolium methyl sulfate, 1-butyl-3-methylimidazolium methylsulfonate, 1-butyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide, etc. be able to.

  The onium salt of the present invention is preferably contained in the photosensitive layer in a proportion of 0.1 to 20% by weight. More preferably, the proportion is 0.5 to 15% by weight. Within these ranges, a desired effect is achieved.

[Vinyl polymer]
The vinyl polymer compound used in the present invention has at least one selected from the group consisting of the following (A), (B) and (C) as a structural unit.
(A) A structural unit derived from a monomer in which a saturated cyclic group containing a carbonyl group as a ring constituent group is directly bonded to a vinyl group, and the cyclic group may have a hetero atom as a ring constituent atom.
(B) a structural unit derived from a monomer in which an unsaturated cyclic group containing at least one nitrogen atom as a ring constituent atom is directly bonded to a vinyl group, wherein the cyclic group is C—N═C Have in bond.
(C) Vinyl acetals.

  Among these, the structural unit (A) can be represented by the following formula (I).

ここでＲ₁、Ｒ₂は同一でも異なっていてもよく、それぞれ単結合、炭素数１〜６のアルキレン基を表すが、環を構成する原子数は５以上になることを条件とする。このアルキレン基は置換基を有していてもよく、また途中に−Ｏ−、−ＮＨ−等のヘテロ原子を含んでもよいが、この場合Ｏ、Ｎはアルキレン基の炭素数１に換算する。またＹ₁はＮ、ＣＨ、ＣＲ₁₄（Ｒ₁₄は炭素数１〜４の置換基を有してもよいアルキル基）を表す。
飽和環状基は、５員環又は６員環が好ましく、５員環がより好ましい。ヘテロ原子としては、Ｏ、Ｎ及びＳが好ましく、Ｏ及びＮがより好ましく、Ｎが特に好ましい。

Here, R ₁ and R ₂ may be the same or different and each represents a single bond or an alkylene group having 1 to 6 carbon atoms, provided that the number of atoms constituting the ring is 5 or more. This alkylene group may have a substituent and may contain a heteroatom such as -O- or -NH- in the middle. In this case, O and N are converted to 1 carbon atom of the alkylene group. Y ₁ represents N, CH, CR ₁₄ (R ₁₄ is an alkyl group which may have a substituent having 1 to 4 carbon atoms).
The saturated cyclic group is preferably a 5-membered ring or a 6-membered ring, and more preferably a 5-membered ring. As a hetero atom, O, N and S are preferable, O and N are more preferable, and N is particularly preferable.

  Examples of such vinyl monomers include N-vinyl pyrrolidone, N-vinyl piperidone, and N-vinyl indolone.

Among these, the case where R ₁ is a single bond, R ₂ is an alkylene group having 3 to 4 carbon atoms, and Y ₁ is N or CH is particularly preferable, and R ₁ is a single bond and R ₂ is carbon. This is the case where the alkylene group of Formula 3 and Y ₁ is N.

Further, (B) can be represented by the following formulas (II) to (IV).
The unsaturated cyclic group is preferably a 5-membered ring or a 6-membered ring, and more preferably a 5-membered ring.

ここでＲ₃は炭素数２〜６のアルキレン基を表す。このアルキレン基は置換基を有していてもよく、また途中に−Ｏ−、−ＮＨ−を含んでもよいが、この場合Ｏ、Ｎはアルキレン基の炭素数１に換算する。またＲ₄、Ｒ₅は同一でも異なっていてもよく、それぞれ独立に、水素原子、ハロゲン、メチル基、又はエチル基を表す。好ましいのは、Ｒ₃が炭素数２〜４のアルキレン基であり、Ｒ₄及びＲ₅が水素原子の場合である。

Here, R ₃ represents an alkylene group having 2 to 6 carbon atoms. This alkylene group may have a substituent, and may include —O— and —NH— in the middle. In this case, O and N are converted to 1 carbon atom of the alkylene group. R ₄ and R ₅ may be the same or different and each independently represents a hydrogen atom, a halogen, a methyl group, or an ethyl group. Preferred is the case where R ₃ is an alkylene group having 2 to 4 carbon atoms and R ₄ and R ₅ are hydrogen atoms.

ここでＲ₆は炭素数２〜６のアルキレン基を表す。このアルキレン基は置換基を有していてもよく、また途中に−Ｏ−、−ＮＨ−を含んでもよいが、この場合Ｏ、Ｎはアルキレン基の炭素数１に換算する。またＲ₇、Ｒ₈は、同一でも異なっていてもよく、それぞれ独立に水素原子、ハロゲン、メチル基、又はエチル基を表す。好ましいのは、Ｒ⁶が炭素数２〜４のアルキレン基であり、Ｒ₇、Ｒ₈が水素原子の場合である。

Here, R ₆ represents an alkylene group having 2 to ₆ carbon atoms. This alkylene group may have a substituent, and may include —O— and —NH— in the middle. In this case, O and N are converted to 1 carbon atom of the alkylene group. R ₇ and R ₈ may be the same or different and each independently represents a hydrogen atom, a halogen, a methyl group, or an ethyl group. Preferred is when R ⁶ is an alkylene group having 2 to 4 carbon atoms and R ₇ and R ₈ are hydrogen atoms.

ここでＲ₉、Ｒ₁₀は同一でも異なっていてもよく、それぞれ炭素数１〜４のアルキレン基を表すが、Ｒ₉、Ｒ₁₀の一方は単結合であってもよい。このアルキレン基は置換基を有していてもよく、また途中に−Ｏ−、−ＮＨ−を含んでもよいが、この場合Ｏ、Ｎはアルキレン基の炭素数１に換算する。Ｒ₁₁、Ｒ₁₂、Ｒ₁₃は、同一でも異なっていてもよく、それぞれ独立に水素原子、ハロゲン原子、メチル基、又はエチル基を表す。またＹ₂はＮ、ＣＨ、ＣＲ₁₅（Ｒ₁₅は炭素数１〜４の置換基を有してもよいアルキル）を表す。

Here, R ₉ and R ₁₀ may be the same or different and each represents an alkylene group having 1 to 4 carbon atoms, and one of R ₉ and R ₁₀ may be a single bond. This alkylene group may have a substituent, and may include —O— and —NH— in the middle. In this case, O and N are converted to 1 carbon atom of the alkylene group. R ₁₁ , R ₁₂ and R ₁₃ may be the same or different and each independently represents a hydrogen atom, a halogen atom, a methyl group or an ethyl group. Y ₂ represents N, CH, CR ₁₅ (R ₁₅ is an alkyl which may have a substituent having 1 to 4 carbon atoms).

Of these, a preferred group combination is when R ₉ is an alkylene group having 1 to 3 carbon atoms, R ₁₀ is a single bond, R ₁₁ , R ₁₂ , and R ₁₃ are all hydrogen atoms, and Y ₂ is N or CH. A particularly preferred group combination is when R ₉ is an alkylene group having 1 carbon atom, R ₁₀ is a single bond, R ₁₁ , R ₁₂ and R ₁₃ are all hydrogen atoms, and Y ₂ is N.
Among the formulas (II) to (IV), it is preferable to include a structural unit derived from the vinyl monomer represented by the formula (IV). As a preferable vinyl monomer corresponding to the formula (IV), N-vinylimidazole can be exemplified.

(C) Structural Unit Derived from Vinyl Acetals In the present invention, “vinyl acetal” has a broad meaning and a narrow meaning. In a broad sense, it means vinyl acetals widely acetalized with an arbitrary aldehyde, and in a narrow sense, it means a structural unit acetalized with acetaldehyde.
The structural unit derived from vinyl acetals can be formed by cyclizing the 1,3-glycol structure of polyvinyl alcohol by acetalization. As a method for producing polyvinyl acetals, a copolymer with vinyl acetate containing a structural unit of polyvinyl alcohol can be acetalized by reaction with various aldehydes in an organic solvent or in an aqueous solution. Examples of aldehydes include formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde or a mixture thereof.
Typical polyvinyl acetals are polyvinyl formal, polyvinyl acetal, and polyvinyl butyral.

The vinyl polymer may be a homopolymer having the above (A), (B) or (C) as a structural unit, but may be a copolymer having other structural units. The copolymer component is not particularly specified as long as it is a monomer copolymerizable with (A), (B) or (C), but vinyl acetate and vinyl alcohol are preferred. Moreover, the copolymer which consists of 2 or more types of structural units which correspond to (A), (B), (C) and which has a different structure can also be used. Further, it may be a copolymer having three or more kinds of structural units. In the case of these copolymers, the proportion of structural units selected from the group consisting of (A), (B) and (C) is preferably at least 10 mol%, particularly preferably 20 mol% or more.
The weight average molecular weight of the vinyl polymer compound is preferably 1,000 or more, and more preferably 1,000 to 300,000.

  Examples of the vinyl polymer that can be used in the present invention include polyvinyl pyrrolidone, vinyl pyrrolidone-vinyl acetate copolymer, vinyl pyrrolidone-vinyl acetate-vinyl alcohol copolymer, vinyl pyrrolidone-vinyl acetal-vinyl acetate-vinyl alcohol copolymer. , Vinyl pyrrolidone-vinyl imidazole copolymer, polyvinyl imidazole, vinyl imidazole-vinyl acetate copolymer, vinyl imidazole-vinyl acetate-vinyl alcohol copolymer, polyvinyl acetal, vinyl acetal-vinyl acetate copolymer, vinyl acetal-acetic acid An example is a vinyl-vinyl alcohol copolymer. Some of the polymers exemplified here are also commercially available.

  The vinyl polymer used in the present invention is preferably contained in the photosensitive layer in a proportion of 10 to 99%. Within this range, the desired effect is achieved. Further, when it is contained in the photosensitive layer in a proportion of 10 to 30%, it is preferable to use another polymer compound in combination.

[Other polymer compounds]
In the lower layer of the present invention, in addition to the vinyl polymer having at least one selected from the group consisting of (A), (B) and (C) as described above, another polymer compound is used in combination. The polymer compound used in combination may be one type or two or more types. In addition, although a polymer compound is used for the upper layer, two or more polymer compounds may be used, and at least one polymer compound different from the lower polymer compound is used. Here, these polymer compounds are described.

The polymer compound used in the present invention is preferably a polymer compound that is soluble or swellable in an alkaline aqueous solution. Examples of such a polymer compound include polymer compounds having the acidic groups listed in the following (1) to (6) in the main chain and / or side chain of the polymer.
(1) Phenol group (-Ar-OH)
(2) Sulfonamide group (—SO ₂ NH—R)
(3) Substituted sulfonamide acid group (hereinafter referred to as “active imide group”)
[—SO ₂ NHCOR, —SO ₂ NHSO ₂ R, —CONHSO ₂ R]
(4) Carboxylic acid group (—CO ₂ H)
(5) Sulfonic acid group (—SO ₃ H)
(6) Phosphate group (—OPO ₃ H ₂ )
In the above (1) to (6), Ar represents a divalent aryl linking group which may have a substituent, and R represents a hydrocarbon group which may have a substituent.

As a high molecular compound which has an acidic group chosen from said (1)-(6), the following can be mentioned, for example.
(1) Examples of the polymer compound having a phenol group include novolak resins, xylenol resins, and resole resins. Specifically, phenol formaldehyde resins, m-cresol formaldehyde resins, p-cresol formaldehyde resins, m // p-mixed cresol formaldehyde resin, phenol / cresol (m-, p-, o-, m- / p-mixed, m- / o-mixed and o- / p-mixed) mixed formaldehyde resin, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol resin, xylenol / phenol mixed resin, xylenol / novolak mixed resin, xylenol / Novolac / phenol mixed resin and pyroga It may be mentioned condensation polymers of Lumpur and acetone. In addition, a polymer compound obtained by copolymerizing a compound having a phenol group in the side chain can also be mentioned, and acrylamide, methacrylamide, acrylic ester or methacrylic ester having a phenol group, hydroxystyrene, or the like is used as a copolymer component. High molecular compounds.

  (2) Examples of the polymer compound having a sulfonamide group include a polymer composed of a minimum structural unit derived from a compound having a sulfonamide group as a main structural unit. Examples of the compound as described above include compounds having at least one sulfonamide group in which at least one hydrogen atom is bonded to a nitrogen atom and one or more polymerizable unsaturated groups in the molecule. Among them, a low molecular compound having an acryloyl group, an allyl group, or a vinyloxy group and a substituted or monosubstituted aminosulfonyl group or a substituted sulfonylimino group in the molecule is preferable. For example, the following formulas (i) to (v) The compound represented by these is mentioned.

（式中、Ｘ¹、Ｘ²は、それぞれ独立に−Ｏ−又は−ＮＲ⁷を表す。Ｒ¹、Ｒ⁴は、それぞれ独立に水素原子又は−ＣＨ₃を表す。Ｒ²、Ｒ⁵、Ｒ⁹、Ｒ¹²、及び、Ｒ¹⁶は、それぞれ独立に置換基を有していてもよい炭素数１〜１２のアルキレン基、シクロアルキレン基、アリーレン基又はアラルキレン基を表す。Ｒ³、Ｒ⁷、及び、Ｒ¹³は、それぞれ独立に水素原子、置換基を有していてもよい炭素数１〜１２のアルキル基、シクロアルキル基、アリール基又はアラルキル基を表す。また、Ｒ⁶、Ｒ¹⁷は、それぞれ独立に置換基を有していてもよい炭素数１〜１２のアルキル基、シクロアルキル基、アリール基、アラルキル基を表す。Ｒ⁸、Ｒ¹⁰、Ｒ¹⁴は、それぞれ独立に水素原子又は−ＣＨ₃を表す。Ｒ¹¹、Ｒ¹⁵は、それぞれ独立に単結合又は置換基を有していてもよい炭素数１〜１２のアルキレン基、シクロアルキレン基、アリーレン基又はアラルキレン基を表す。Ｙ¹、Ｙ²は、それぞれ独立に単結合又はＣＯを表す。）

(In the formula, X ¹ and X ² each independently represent —O— or —NR ^7. R ¹ and R ⁴ each independently represent a hydrogen atom or —CH _3. R ² , R ⁵ , R ⁹ , R ¹² , and R ¹⁶ each independently represent a C 1-12 alkylene group, cycloalkylene group, arylene group, or aralkylene group that may have a substituent, R ³ , R ⁷ , And R ¹³ each independently represents a hydrogen atom, an optionally substituted alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, an aryl group or an aralkyl group, and R ⁶ and R ¹⁷ are Each independently represents an optionally substituted alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, an aryl group or an aralkyl group, wherein R ⁸ , R ¹⁰ and R ¹⁴ are each independently a hydrogen atom or —CH ₃ R ¹¹ and R ¹⁵ each independently represents a single bond. Or an optionally substituted alkylene group having 1 to 12 carbon atoms, cycloalkylene group, arylene group or aralkylene group, Y ¹ and Y ² each independently represents a single bond or CO.)

  Of the compounds represented by the formulas (i) to (v), in the multi-layer sensitive material type printing plate precursor (the planographic printing plate precursor described in the above 2) of the present invention, in particular, m-aminosulfonylphenyl methacrylate, N -(P-aminosulfonylphenyl) methacrylamide, N- (p-aminosulfonylphenyl) acrylamide and the like can be preferably used.

  (3) As a high molecular compound which has an active imide group, the polymer which makes the minimum structural unit derived from the compound which has an active imide group the main structural unit can be mentioned, for example. Examples of the compound as described above include compounds each having one or more active imide groups represented by the following structural formula and polymerizable unsaturated groups in the molecule.

具体的には、Ｎ−（ｐ−トルエンスルホニル）メタクリルアミド、Ｎ−（ｐ−トルエンスルホニル）アクリルアミド等を好適に使用することができる。

Specifically, N- (p-toluenesulfonyl) methacrylamide, N- (p-toluenesulfonyl) acrylamide and the like can be preferably used.

  (4) As a high molecular compound having a carboxylic acid group, for example, a minimum structural unit derived from a compound having at least one carboxylic acid group and polymerizable unsaturated group in the molecule is a main structural unit. A polymer can be mentioned. Acrylic acid, methacrylic acid, maleic acid, and itaconic acid can be particularly preferably used in the multilayer sensitive material type printing plate precursor of the present invention.

  (5) As a high molecular compound having a sulfonic acid group, for example, a minimum structural unit derived from a compound having at least one sulfonic acid group and polymerizable unsaturated group in the molecule is used as a main structural unit. A polymer can be mentioned.

(6) As a high molecular compound having a phosphoric acid group, for example, a minimum structural unit derived from a compound having at least one phosphoric acid group and a polymerizable unsaturated group in the molecule is used as a main structural unit. A polymer can be mentioned.
In addition to the above, a polymer using an unsaturated compound having an acidic group of (1) to (6) in the side chain and a urea bond as a linking group can also be used.

  Among the polymer compounds having an acidic group selected from (1) to (6) above, (1) a phenol group, (2) a sulfonamide group, (3) an active imide group, and (4) a carboxylic acid group Molecular compounds are preferred, and in particular, a polymer compound having (1) a phenol group, (2) a sulfonamide group, or (4) a carboxylic acid group is most preferred.

The minimum structural unit having an acidic group selected from the above (1) to (6) is not particularly limited to one kind, and two or more minimum structural units having the same acidic group are used, or different acidic groups are used. What copolymerized 2 or more types of the minimum structural unit which has can also be used.
In the case where the polymer compound is a copolymer, it is preferable that a compound having an acidic group selected from (1) to (6) to be copolymerized is contained in an amount of 3 mol% or more in the copolymer. % Is more preferable. If it is less than 3 mol%, the solubility in an alkaline developer containing substantially no solvent will decrease.

As the monomer component to be copolymerized with the polymerizable monomer having an acidic group, for example, monomers listed in the following (m1) to (m11) can be used, but are not limited thereto.
(M1) Acrylic acid esters and methacrylic acid esters having an aliphatic hydroxyl group such as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate.
(M2) Alkyl acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, benzyl acrylate, 2-chloroethyl acrylate, and glycidyl acrylate.
(M3) Alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, 2-chloroethyl methacrylate, and glycidyl methacrylate.
(M4) Acrylamide, methacrylamide, N-methylol acrylamide, N-ethyl acrylamide, N-hexyl methacrylamide, N-cyclohexyl acrylamide, N-hydroxyethyl acrylamide, N-phenyl acrylamide, N-nitrophenyl acrylamide, N-ethyl- Acrylamide or methacrylamide such as N-phenylacrylamide.
(M5) Vinyl ethers such as ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, octyl vinyl ether, and phenyl vinyl ether.
(M6) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate and vinyl benzoate.
(M7) Styrenes such as styrene, α-methylstyrene, methylstyrene, chloromethylstyrene.
(M8) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone.
(M9) Olefins such as ethylene, propylene, isobutylene, butadiene and isoprene.
(M10) N-vinylpyrrolidone, acrylonitrile, methacrylonitrile and the like.
(M11) Unsaturated imides such as maleimide, N-phenylmaleimide, N-acryloylacrylamide, N-acetylmethacrylamide, N-propionylmethacrylamide, N- (p-chlorobenzoyl) methacrylamide.

In the present invention, the polymer compound may be used in combination of two or more different polymer compounds.
Of the polymer compounds exemplified above, the polymer compound used in the lower layer is preferably a copolymer having a sulfonamide group and / or a carboxylic acid group, and the copolymer component may be an alkyl (meth) acrylate. , (Meth) acrylamide, (meth) acrylonitrile, and N-phenylmaleimide. Also, novolak resins are preferably used, such as phenol formaldehyde resin, m-cresol formaldehyde resin, p-cresol formaldehyde resin, m- / p-mixed cresol formaldehyde resin, phenol / cresol (m-, p-, o-, m Any of-/ p-mixing, m- / o-mixing, and o- / p-mixing may be used.) A mixed formaldehyde resin may be mentioned. As described above, two or more polymer compounds may be used in combination.

  Moreover, as a high molecular compound used for an upper layer, a novolak resin and a xylenol resin are preferably used, and a phenol formaldehyde resin, m-cresol formaldehyde resin, p-cresol formaldehyde resin, m / p-mixed cresol formaldehyde resin, phenol / Cresol (m-, p-, o-, m- / p-mixed, m- / o-mixed and o- / p-mixed) mixed formaldehyde resin, 2,3-xylenol, 2,4- Xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol resin, xylenol / phenol mixed resin, xylenol / novolak mixed resin, xylenol / novolak / phenol mixed resin, etc. Can do. However, when these polymer compounds are used alone, it is a condition that they are not used in the lower layer.

  In the present invention, when the polymer compound is a resin such as phenol formaldehyde resin or cresol aldehyde resin, those having a weight average molecular weight of 500 to 20,000 and a number average molecular weight of 200 to 10,000 are preferred. In the case of other polymer compounds, those having a weight average molecular weight of 2,000 or more and a number average molecular weight of 500 or more are preferred, more preferably a weight average molecular weight of 5,000 to 300,000, Is 800 to 250,000, and the dispersity (weight average molecular weight / number average molecular weight) is 1.1 to 10.

  In the present invention, the polymer compound is used in an amount of 30 to 99% by weight, preferably 50 to 99% by weight, particularly preferably 65 to 99% by weight. It is preferable that the addition amount of the polymer compound is within the above range because the heat sensitive layer has high durability and high sensitivity.

[Infrared absorber]
As the infrared absorber, known various pigments and dyes are preferably exemplified. Examples of the pigment include a commercially available pigment and color index (CI) manual, “Latest Pigment Handbook” (edited by the Japan Pigment Technology Association, published in 1977), “Latest Pigment Applied Technology” (published by CMC, published in 1986), “ Examples thereof include pigments described in "Printing Ink Technology", published by CMC Publishing, 1984).
Examples of the pigment include black pigments, yellow pigments, orange pigments, brown pigments, red pigments, purple pigments, blue pigments, green pigments, fluorescent pigments, metal powder pigments, and other polymer-bonded dyes. Specifically, insoluble azo pigments, azo lake pigments, condensed azo pigments, chelate azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments Quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black and the like.

  The pigment may be used without being subjected to a surface treatment or may be used after being subjected to a surface treatment. The surface treatment method includes a method of surface coating with a resin or wax, a method of attaching a surfactant, a method of bonding a reactive substance (for example, silane coupling agent, epoxy compound, polyisocyanate, etc.) to the pigment surface, etc. Can be considered. The surface treatment method is described in “Characteristics and Applications of Metal Soap” (Sachishobo), “Printing Ink Technology” (CMC Publishing, 1984) and “Latest Pigment Application Technology” (CMC Publishing, 1986). .

  The particle diameter of the pigment is preferably 0.01 to 10 μm, more preferably 0.05 to 1 μm, and particularly preferably 0.1 to 1 μm. When the particle size of the pigment is within the above range, the coating solution is stable and a uniform photosensitive layer can be obtained.

As a method for dispersing the pigment, a known dispersion technique used in ink production, toner production, or the like can be used. For the dispersion, a disperser such as 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, or a pressure kneader is used. Details are described in "Latest Pigment Applied Technology" (CMC Publishing, 1986).
Examples of the dye include commercially available dyes and known dyes described in the literature (for example, “Dye Handbook” edited by the Society of Synthetic Organic Chemistry, published in 1970), such as azo dyes, metal complex azo dyes, pyrazolone azos. And dyes such as dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, and cyanine dyes. Among the pigments or dyes, pigments and dyes that absorb infrared light or near infrared light are particularly preferable because they are suitable for use in lasers that emit infrared light or near infrared light.

Carbon black is preferably used as the pigment that absorbs the infrared light or near infrared light. Examples of the dye that absorbs the infrared light or near infrared light include, for example, JP-A-58-125246, JP-A-59-84356, JP-A-59-202829, and JP-A-60-78787. Methine dyes described in JP-A-58-173696, JP-A-58-181690, JP-A-58-194595, etc., JP-A-58-112793, Naphthoquinone dyes described in JP-A-58-224793, JP-A-59-48187, JP-A-59-73996, JP-A-60-52940, JP-A-60-63744, etc. Examples thereof include squarylium dyes described in JP-A-58-112792, and cyanine dyes described in British Patent 434,875.
Further, as the dye, a near-infrared absorption sensitizer described in US Pat. No. 5,156,938 is also preferably used, and substituted arylbenzo (described in US Pat. No. 3,881,924) Thio) pyrylium salt, trimethine thiapyrylium salt described in JP-A-57-142645 (US Pat. No. 4,327,169), JP-A-58-181051, 58-220143, 59-41363 59-84248, 59-84249, 59-146063, 59-146061, pyranyl compounds described in JP-A-59-216146, cyanine dyes described in US Pat. The pentamethine thiopyrylium salt described in No. 283,475 and the pyrilylation disclosed in Japanese Patent Publication Nos. 5-13514 and 5-19702 Things, Epolight III-178, EpolightIII-130, Epolight III-125, EpolightV-176A or the like is used particularly preferably.

  Moreover, as said dye, as another especially preferable example, the near-infrared absorptive dye described as U.S. Pat. No. 4,756,993 as the formulas (I) and (II) can be mentioned. The amount of the pigment or dye added is preferably 0.01 to 50% by weight, more preferably 0.1 to 10% by weight, based on the total solid content of the printing plate material. In the case of the dye, 0.5 to 10% by weight is particularly preferable, and in the case of a pigment, 3.1 to 10% by weight is particularly preferable. Within the above range, high sensitivity can be obtained, a uniform photosensitive layer can be maintained, and the durability of the recording layer is high.

[Other ingredients]
If necessary, various additives can be added to the coating layer according to the present invention.
For example, in order to adjust the solubility of the recording layer, when other onium salts, aromatic sulfone compounds, aromatic sulfonic acid ester compounds, polyfunctional amine compounds, etc. are added, development of an alkali water-soluble polymer (alkali-soluble resin) is performed. It is preferable to add a so-called dissolution inhibitor that improves the dissolution inhibition function in the liquid, and among them, onium salts, o-quinonediazide compounds, sulfonic acid alkyl esters and the like are thermally decomposable, and in a state where they are not decomposed, alkali-soluble resins It is preferable to use a substance that substantially lowers solubility in that the ability to inhibit dissolution of the image area in the developer can be controlled.

  Preferred examples of the onium salt used in the present invention include S.P. I. Schlesinger, Photogr. Sci. Eng. , 18, 387 (1974), T.A. S. Bal et al, Polymer, 21, 423 (1980), diazonium salts described in JP-A-5-158230, U.S. Pat. Nos. 4,069,055, 4,069,056, and JP-A-3-140140. Ammonium salts described in the specification of C. Necker et al, Macromolecules, 17, 2468 (1984), C.I. S. Wen et al, Teh, Proc. Conf. Rad. Curing ASIA, p478 Tokyo, Oct (1988), U.S. Pat. Nos. 4,069,055 and 4,069,056; V. Crivello et al, Macromolecules, 10 (6), 1307 (1977), Chem. & Eng. News, Nov. 28, p31 (1988), European Patent No. 104,143, US Pat. Nos. 5,041,358, 4,491,628, JP-A-2-150848 and JP-A-2-296514. Iodonium salts, J.M. V. Crivello et al, Polymer J. et al. 17, 73 (1985), J. Am. V. Crivello et al. J. et al. Org. Chem. 43, 3055 (1978); R. Watt et al, J.A. Polymer Sci. , Polymer Chem. Ed. , 22, 1789 (1984), J. Am. V. Crivello et al, Polymer Bull. 14, 279 (1985), J. Am. V. Crivello et al, Macromolecules, 14 (5), 1141 (1981), J. MoI. V. Crivello et al, J.A. Polymer Sci. , Polymer Chem. Ed. 17, 2877 (1979), European Patents 370,693, 233,567, 297,443, 297,442, U.S. Pat. Nos. 4,933,377, 3,902,114 No. 5,041,358, No. 4,491,628, No. 4,760,013, No. 4,734,444, No. 2,833,827, German Patent No. 2,904 No. 626, No. 3,604,580, No. 3,604,581, sulfonium salts described in J.P. V. Crivello et al, Macromolecules, 10 (6), 1307 (1977), J. MoI. V. Crivello et al, J.A. Polymer Sci. , Polymer Chem. Ed. , 17, 1047 (1979), a selenonium salt described in C.I. S. Wen et al, Teh, Proc. Conf. Rad. Curing ASIA, p478 Tokyo, Oct (1988).

  Among these onium salts, diazonium salts and quaternary ammonium salts are particularly preferable from the viewpoints of dissolution inhibition ability and thermal decomposability. In particular, the diazonium salt is preferably a diazonium salt represented by the general formula (I) described in JP-A-5-158230 or a diazonium salt represented by the general formula (1) described in JP-A-11-143064. The diazonium salt represented by the general formula (1) described in JP-A-11-143064 having a small absorption wavelength in the visible light region is most preferable. Moreover, as a quaternary ammonium salt, the quaternary ammonium salt shown by (1)-(10) in (Chemical Formula 7) and (Chemical Formula 8) of Unexamined-Japanese-Patent No. 2002-229186 is preferable.

  The counter ion of the onium salt includes tetrafluoroboric acid, hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid, 5-nitro-o-toluenesulfonic acid, 5-sulfosalicylic acid, 2,5-dimethylbenzenesulfonic acid, 2,4,6-trimethylbenzenesulfonic acid, 2-nitrobenzenesulfonic acid, 3-chlorobenzenesulfonic acid, 3-bromobenzenesulfonic acid, 2-fluorocaprylnaphthalenesulfonic acid, dodecylbenzenesulfonic acid, 1-naphthol-5-sulfone Examples include acid, 2-methoxy-4-hydroxy-5-benzoyl-benzenesulfonic acid, and paratoluenesulfonic acid. Of these, particularly preferred are alkyl aromatic sulfonic acids such as hexafluorophosphoric acid, triisopropylnaphthalenesulfonic acid and 2,5-dimethylbenzenesulfonic acid.

  Suitable quinonediazides include o-quinonediazide compounds. The o-quinonediazide compound used in the present invention is a compound having at least one o-quinonediazide group, which increases alkali solubility by thermal decomposition, and compounds having various structures can be used. That is, o-quinonediazide helps the solubility of the sensitive material system by both the effect of losing the ability to suppress the dissolution of the binder due to thermal decomposition and the change of o-quinonediazide itself into an alkali-soluble substance. Examples of the o-quinonediazide compound used in the present invention include J. Although the compounds described in pages 339 to 352 of “Light-Sensitive Systems” by John Coser (John Wiley & Sons. Inc.) can be used, they are particularly reacted with various aromatic polyhydroxy compounds or aromatic amino compounds. -Sulfonic acid esters or sulfonic acid amides of quinonediazides are preferred. Further, benzoquinone (1,2) -diazide sulfonic acid chloride or naphthoquinone- (1,2) -diazide-5-sulfonic acid chloride and pyrogallol-acetone resin as described in JP-B-43-28403 Esters of benzoquinone- (1,2) -diazide sulfonic acid chloride or naphthoquinone- (1,2) -diazide- described in US Pat. Nos. 3,046,120 and 3,188,210 Esters of 5-sulfonic acid chloride and phenol-formaldehyde resin are also preferably used.

  Further, an ester of naphthoquinone- (1,2) -diazido-4-sulfonic acid chloride and phenol formaldehyde resin or cresol-formaldehyde resin, naphthoquinone- (1,2) -diazido-4-sulfonic acid chloride and pyrogallol-acetone resin Similarly, the esters are also preferably used. Other useful o-quinonediazide compounds are reported and known in numerous patents. For example, JP-A-47-5303, JP-A-48-63802, JP-A-48-63803, JP-A-48-96575, JP-A-49-38701, JP-A-48-13354, Japanese Patent Publication Nos. 41-11222, 45-9610, 49-17474, U.S. Pat. Nos. 2,797,213, 3,454,400, 3,544,323, 3,573,917, 3,674,495, 3,785,825, British Patents 1,227,602, 1,251,345, 1,267, No. 005, No. 1,329,888, No. 1,330,932, German Patent No. 854,890, and the like.

  The amount of onium salt and / or o-quinonediazide compound that is a degradable dissolution inhibitor is preferably 1 to 10% by weight, more preferably 1 to 5% by weight, particularly preferably based on the total solid content of the recording layer. Is in the range of 1-2% by weight. These compounds can be used alone, but may be used as a mixture of several kinds.

  The amount of additives other than the o-quinonediazide compound is preferably 0.1 to 5% by weight, more preferably 0.1 to 2% by weight, and particularly preferably 0.1 to 1.5% by weight. The additive and binder according to the present invention are preferably contained in the same layer.

Further, a dissolution inhibitor having no decomposability may be used in combination, and preferred dissolution inhibitors include sulfonate esters, phosphate esters, and aromatic carboxylic acids described in detail in JP-A-10-268512. Esters, aromatic disulfones, carboxylic anhydrides, aromatic ketones, aromatic aldehydes, aromatic amines, aromatic ethers, etc., as well as lactone skeletons described in detail in JP-A-11-190903, N, N- Examples thereof include an acid color-forming dye having a diarylamide skeleton and a diarylmethylimino skeleton, which also serves as a colorant, and nonionic surfactants described in detail in JP-A No. 2000-105454.
Moreover, in the photosensitive composition of this invention, cyclic acid anhydrides, phenols, and organic acids can be used together for the purpose of improving a sensitivity. Further, a surfactant, an image colorant, and a plasticizer, which will be described later, can also be used for the positive recording layer of the present invention.

Examples of cyclic acid anhydrides include phthalic anhydride, tetrahydrophthalic anhydride, 3,6-endooxy-4-tetrahydrophthalic anhydride, tetrachlorophthalic anhydride described in US Pat. No. 4,115,128, Maleic anhydride, chloromaleic anhydride, α-phenylmaleic anhydride, succinic anhydride, pyromellitic anhydride and the like can be used. As phenols, bisphenol A, p-nitrophenol, p-ethoxyphenol, 2,4,4′-trihydroxybenzophenone, 2,3,4-trihydroxybenzophenone, 4-hydroxybenzophenone, 4,4 ′, 4 “-Trihydroxytriphenylmethane, 4,4 ′, 3”, 4 ”-tetrahydroxy-3,5,3 ′, 5′-tetramethyltriphenylmethane and the like. Examples thereof include sulfonic acids, sulfinic acids, alkylsulfuric acids, phosphonic acids, phosphate esters, and carboxylic acids described in JP-A-60-88942 and JP-A-2-96755.
The proportion of the cyclic acid anhydride, phenols and organic acids in the recording layer is preferably 0.05 to 20% by weight, more preferably 0.1 to 15% by weight, particularly preferably 0.1 to 0.1% by weight. 10% by weight.

  In addition to these, epoxy compounds, vinyl ethers, and further, phenol compounds having a hydroxymethyl group, phenol compounds having an alkoxymethyl group described in JP-A-8-276558, and the inventors previously proposed. A crosslinkable compound having an alkali dissolution inhibiting action described in JP-A-11-160860 can be appropriately added depending on the purpose.

Further, a printing-out agent for obtaining a visible image immediately after heating by exposure, or a dye or pigment as an image colorant can be added.
Typical examples of the printing-out agent include a combination of a compound that releases an acid by heating by exposure (photoacid releasing agent) and an organic dye that can form a salt. Specifically, combinations of o-naphthoquinonediazide-4-sulfonic acid halides and salt-forming organic dyes described in JP-A-50-36209 and JP-A-53-8128, 36223, 54-74728, 60-3626, 61-143748, 61-151644 and 63-58440, and trihalomethyl compounds and salt-forming organic dyes Can be mentioned. Such trihalomethyl compounds include oxazole-based compounds and triazine-based compounds, both of which have excellent temporal stability and give clear printout images.

  As the image colorant, other dyes can be used in addition to the above-mentioned salt-forming organic dyes. Examples of suitable dyes including salt-forming organic dyes include oil-soluble dyes and basic dyes. Specifically, Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS, Oil Blue # 603, Oil Black BY, Oil Black BS, Oil Black T-505 (oriental chemical industry) Manufactured by Co., Ltd.), Victoria Pure Blue, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), Malachite Green (CI42000), Methylene Blue (CI522015), and the like. The dyes described in JP-A-62-293247 are particularly preferred. These dyes can be added to the recording layer in a proportion of 0.01 to 10% by weight, preferably 0.1 to 3% by weight, based on the total solid content of the photosensitive layer or lower layer (recording layer). The photosensitive layer or the lower layer (recording layer) can be obtained by coating a photosensitive composition containing at least a polymer compound and an infrared absorber on a hydrophilic support.

  Furthermore, a plasticizer is added to the photosensitive composition used in the present invention, if necessary, in order to impart flexibility and the like of the coating film. For example, butylphthalyl, polyethylene glycol, tributyl citrate, diethyl phthalate, dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, tricresyl phosphate, tributyl phosphate, trioctyl phosphate, tetrahydrofurfuryl oleate, acrylic acid or methacrylic acid These oligomers and polymers are used.

[Coating solvent and coating method]
The recording layer can be produced by dissolving the photosensitive composition used in the present invention in a solvent and coating it on a suitable support. Further, depending on the purpose, a protective layer, a resin intermediate layer, a backcoat layer and the like, which will be described later, can be formed in the same manner.
Solvents used here include 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, dimethoxy Examples include ethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyrolactone, and toluene. It is not limited. These solvents are used alone or in combination.
The concentration of the above components (total solid content including additives) in the solvent is preferably 1 to 50% by weight.

The coating, solid coating amount on the support obtained after drying, the top layer 0.05 to 2.0 g / m ^2, the lower layer is preferably each 0.3 to 5.0 g / m ^2, more preferably the upper layer Is in the range of 0.1 to 1.0 g / m ² , and the lower layer is in the range of 0.5 to 3.0 g / m ² . Moreover, 0.05-1 are preferable and, as for ratio of the coating amount of an upper layer and a lower layer, More preferably, it is the range of 0.1-0.8.
In the case of a single layer structure, the photosensitive layer preferably has a coating amount corresponding to the lower layer of the multilayer structure.
Various methods can be used for applying the recording layer coating liquid. For example, bar coater coating, spin coating, spray coating, curtain coating, dip coating, air knife coating, blade coating, roll coating, etc. Can be mentioned. As the coating amount decreases, the apparent sensitivity increases, but the film properties of the photosensitive film deteriorate.

[Support]
The support used in the lithographic printing plate precursor using the photosensitive composition according to the present invention is a dimensionally stable plate-like material that satisfies the required physical properties such as strength and flexibility. There is no particular limitation as long as it is, for example, paper, paper laminated with plastic (for example, polyethylene, polypropylene, polystyrene, etc.), metal plate (for example, aluminum, zinc, copper, etc.), plastic film (for example, cellulose diacetate, Cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), paper or plastic film on which a metal as described above is laminated or vapor-deposited Etc.

  As a support that can be applied to a lithographic printing plate precursor, a polyester film or an aluminum plate is preferable, and among them, an aluminum plate that has good dimensional stability and is relatively inexpensive is particularly preferable. A suitable aluminum plate is a pure aluminum plate or an alloy plate containing aluminum as a main component and containing a trace amount of foreign elements, and may be a plastic film on which aluminum is laminated or vapor-deposited. Examples of foreign elements contained in the aluminum alloy include silicon, iron, manganese, copper, magnesium, chromium, zinc, bismuth, nickel, and titanium. The content of foreign elements in the alloy is at most 10% by weight. Particularly suitable aluminum in the present invention is pure aluminum, but completely pure aluminum is difficult to produce in the refining technique, and may contain slightly different elements.

  Thus, the composition of the aluminum plate applied to the present invention is not specified, and an aluminum plate made of a publicly known material can be appropriately used. The thickness of the aluminum plate used in the present invention is about 0.1 mm to 0.6 mm, preferably 0.12 mm to 0.4 mm.

Prior to roughening the aluminum plate, a degreasing treatment with, for example, a surfactant, an organic solvent, or an alkaline aqueous solution for removing rolling oil on the surface is performed as desired. The surface roughening treatment of the aluminum plate is performed by various methods. For example, a method of mechanically roughening, a method of electrochemically dissolving and roughening a surface, and a method of selectively dissolving a surface chemically. This is done by the method of As the mechanical method, a known method such as a ball polishing method, a brush polishing method, a blast polishing method, or a buff polishing method can be used. Further, as an electrochemical surface roughening method, there is a method of performing alternating current or direct current in hydrochloric acid or nitric acid electrolyte. Further, as disclosed in Japanese Patent Laid-Open No. 54-63902, a method in which both are combined can also be used. Among these, it is preferable to include a step of roughening at least in a hydrochloric acid electrolyte.
The roughened aluminum plate is subjected to alkali etching treatment and neutralization treatment as necessary, and then subjected to anodization treatment if desired in order to enhance the water retention and wear resistance of the surface. As the electrolyte used for the anodizing treatment of the aluminum plate, various electrolytes that form a porous oxide film can be used. In general, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, or a mixed acid thereof is used. The concentration of these electrolytes is appropriately determined depending on the type of electrolyte. The anodizing treatment conditions vary depending on the electrolyte used and cannot be specified in general, but in general, the electrolyte concentration is 1 to 80% by weight solution, the liquid temperature is 5 to 70 ° C., and the current density is 5 to 60 A / dm ^2. A voltage of 1 to 100 V and an electrolysis time of 10 seconds to 5 minutes are suitable. When the amount of the anodized film is less than 1.0 g / m ² , the printing durability is insufficient, or the non-image portion of the planographic printing plate is easily damaged, and the ink adheres to the damaged portion during printing. So-called “scratch stains” easily occur.

  After the anodizing treatment, the aluminum surface is subjected to a hydrophilic treatment if necessary. The hydrophilization treatment used in the present invention is disclosed in US Pat. Nos. 2,714,066, 3,181,461, 3,280,734 and 3,902,734. There are alkali metal silicate (such as aqueous sodium silicate) methods. In this method, the support is immersed in an aqueous sodium silicate solution or electrolytically treated. In addition, it is disclosed in potassium fluoride zirconate disclosed in Japanese Patent Publication No. 36-22063 and US Pat. Nos. 3,276,868, 4,153,461, and 4,689,272. A method of treating with polyvinylphosphonic acid is used.

(Undercoat layer)
The lithographic printing plate precursor using the photosensitive composition is provided with the image recording layer as described above on a support, and an undercoat layer is provided between the support and the lower layer as necessary. Can be provided. By providing this undercoat layer, the undercoat layer between the support and the recording layer functions as a heat insulating layer, and the heat generated by the infrared laser exposure does not diffuse to the support and can be used efficiently. Therefore, there is an advantage that high sensitivity can be achieved. In addition, since the recording layer according to the present invention is located on the exposed surface or in the vicinity thereof even when the undercoat layer is provided, the sensitivity to the infrared laser is maintained well.

In the unexposed area, the recording layer itself that is impermeable to the alkaline developer functions as a protective layer for the undercoat layer, so that the development stability is good and the image is excellent in discrimination. In the exposed area, the components of the recording layer whose dissolution-inhibiting ability is released are quickly dissolved and dispersed in the developer. Since the undercoat layer itself, which is adjacent to the support, is made of an alkali-soluble polymer, it has good solubility in a developer, for example, even when a developer with reduced activity is used. It is considered that this undercoat layer is useful because it dissolves rapidly without the formation of a film and the like and contributes to the improvement of developability.
Various organic compounds are used as the primer layer component. For example, phosphonic acids having an amino group such as carboxymethylcellulose, dextrin, gum arabic, 2-aminoethylphosphonic acid, and phenylphosphonic acid which may have a substituent Organic phosphonic acids such as naphthyl phosphonic acid, alkyl phosphonic acid, glycero phosphonic acid, methylene diphosphonic acid and ethylene diphosphonic acid, phenyl phosphoric acid which may have a substituent, naphthyl phosphoric acid, alkyl phosphoric acid and glycerophosphoric acid Organic phosphoric acid, optionally substituted phenylphosphinic acid, naphthylphosphinic acid, alkylphosphinic acid, glycerophosphinic acid and other organic phosphinic acids, glycine and β-alanine amino acids, and triethanolamine hydrochloric acid Has a hydroxy group such as salt -Alanine, and hydrochlorides of amines that may be used in combination of two or more.

  Furthermore, an undercoat layer containing at least one compound selected from the group of organic polymer compounds having a structural unit represented by the following formula is also preferred.

式中、Ｒ¹¹は水素原子、ハロゲン原子又はアルキル基を表し、Ｒ¹²及びＲ¹³はそれぞれ独立して、水素原子、水酸基、ハロゲン原子、アルキル基、置換アルキル基、アリール基、置換アリール基、−ＯＲ¹⁴、−ＣＯＯＲ¹⁵、−ＣＯＮＨＲ¹⁶、−ＣＯＲ¹⁷若しくは−ＣＮを表すか、又はＲ¹²及びＲ¹³が結合して環を形成してもよく、Ｒ¹⁴〜Ｒ¹⁷はそれぞれ独立してアルキル基又はアリール基を表し、Ｘは水素原子、金属原子、ＮＲ¹⁸Ｒ¹⁹Ｒ²⁰Ｒ²¹を表し、Ｒ¹⁸〜Ｒ²¹はそれぞれ独立して、水素原子、アルキル基、置換アルキル基、アリール基若しくは置換アリール基を表すか、又はＲ¹⁸及びＲ¹⁹が結合して環を形成してもよく、ｍは１〜３の整数を表す。

In the formula, R ¹¹ represents a hydrogen atom, a halogen atom or an alkyl group, and R ¹² and R ¹³ each independently represent a hydrogen atom, a hydroxyl group, a halogen atom, an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, -OR ¹⁴ , -COOR ¹⁵ , -CONHR ¹⁶ , -COR ¹⁷ or -CN, or R ¹² and R ¹³ may be bonded to form a ring, and R ^{14 to} R ¹⁷ are each independently Represents an alkyl group or an aryl group, X represents a hydrogen atom, a metal atom, or NR ¹⁸ R ¹⁹ R ²⁰ R ²¹ , and R ^{18 to} R ²¹ each independently represent a hydrogen atom, an alkyl group, a substituted alkyl group, or an aryl group. Alternatively, it represents a substituted aryl group, or R ¹⁸ and R ¹⁹ may combine to form a ring, and m represents an integer of 1 to 3.

Moreover, as a suitable undercoat layer component in the present invention, there can be mentioned a polymer compound having a structural unit having an acid group and a structural unit having an onium group, as described in JP-A No. 2000-241962. Specific examples include a copolymer of a monomer having an acid group and a monomer having an onium group. The acid group is preferably an acid group having an acid dissociation index (pKa) of 7 or more, more preferably —COOH, —SO ₃ H, —OSO ₃ H, —PO ₃ H ₂ , —OPO ₃ H ₂ , — CONHSO ₂ — or —SO ₂ NHSO ₂ —, particularly preferably —COOH. Specific examples of the monomer having an acid group include acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, itaconic acid, maleic acid, maleic anhydride, and styrene having the acid group. Preferred as the onium salt is an onium group composed of Group V or Group VI atoms, more preferably an onium salt composed of nitrogen, phosphorus or sulfur atoms, and particularly preferably an onium salt composed of nitrogen atoms. Salt. Specific examples of the monomer having an onium salt include styrene having a substituent containing an onium group such as a methacrylate having an ammonium group in the side chain, a methacrylamide, a substituent containing an onium group such as a quaternary ammonium group, and the like. It is done.
Furthermore, compounds described in JP-A No. 2000-108538, Japanese Patent Application No. 2002-257484, Japanese Patent Application No. 2003-78699, and the like can be used as necessary.

These undercoat layers can be provided by the following method. That is, a method in which water or an organic solvent such as methanol, ethanol, methyl ethyl ketone, or a mixed solvent thereof is dissolved and applied on an aluminum plate and dried, and water, methanol, ethanol, methyl ethyl ketone, etc. In this method, an aluminum plate is immersed in a solution in which the above organic compound is dissolved in the above organic solvent or a mixed solvent thereof to adsorb the above compound, and then washed and dried with water or the like to provide an undercoat layer. In the former method, a solution having a concentration of 0.005 to 10% by weight of the organic compound can be applied by various methods. In the latter method, the concentration of the solution is 0.01 to 20% by weight, preferably 0.05 to 5% by weight, the immersion temperature is 20 to 90 ° C., preferably 25 to 50 ° C., and the immersion time is 0.1 second to 20 minutes, preferably 2 seconds to 1 minute. The solution used for this can be adjusted to a pH range of 1 to 12 with basic substances such as ammonia, triethylamine, potassium hydroxide, and acidic substances such as hydrochloric acid and phosphoric acid. A yellow dye can also be added to improve the tone reproducibility of the image recording material. The coating amount of the undercoat layer is suitably ² to 200 mg / m ² , preferably 5 to 100 mg / m ² . If the coating amount is less than 2 mg / m ² , sufficient printing durability cannot be obtained. The same is true even if it is larger than 200 mg / m ² .

〔exposure〕
The lithographic printing plate precursor using the photosensitive composition of the present invention is image-formed by heat. Specifically, direct image-like recording using a thermal recording head, scanning exposure using an infrared laser, high-illuminance flash exposure such as a xenon discharge lamp, infrared lamp exposure, and the like are used, but a semiconductor that emits infrared light having a wavelength of 700 to 1200 nm. Exposure by a solid high-power infrared laser such as a laser or a YAG laser is suitable.
The laser output is preferably 100 mW or more, and a multi-beam laser device is preferably used in order to shorten the exposure time. The exposure time per pixel is preferably within 20 μsec, and the energy applied to the recording material is preferably 10 to 500 mJ / cm ² .

〔developing〕
In the present invention, the exposed photosensitive lithographic printing plate is preferably developed with an alkaline aqueous solution having a pH of 12 or higher that does not substantially contain an organic solvent. Here, “substantially free of organic solvent” means that it does not contain an organic solvent to the extent of causing inconvenience in terms of environmental health, safety, workability, etc. The ratio of the organic solvent in the developer is 0.5% by weight or less, preferably 0.3% by weight or less, and most preferably not contained at all. Moreover, although pH is 12.0 or more, More preferably, it is 12.0-14.0.

A conventionally known alkaline aqueous solution can be used as the developer (hereinafter referred to as developer including the replenisher). For example, sodium silicate, potassium, tribasic sodium phosphate, potassium, ammonium, dibasic sodium phosphate, potassium, ammonium, sodium carbonate, potassium, ammonium, sodium bicarbonate, potassium, Examples include inorganic alkali salts such as ammonium, sodium borate, potassium, ammonium, sodium hydroxide, ammonium, potassium, and lithium. Moreover, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, Organic alkali agents such as ethyleneimine, ethylenediamine, and pyridine are listed. These alkaline aqueous solutions may be used individually by 1 type, and may use 2 or more types together.
Among the above alkaline aqueous solutions, one of the developing solutions that exert the effect according to the present invention is a so-called one containing an alkali silicate as a base, or containing an alkali silicate by mixing a silicon compound with a base. Another more preferable developer, which is an aqueous solution called “silicate developer” having a pH of 12 or more, does not contain an alkali silicate, and contains a non-reducing sugar (an organic compound having a buffering action) and a base. Silicate developer ".
In the former, the aqueous solution of alkali metal silicate is a ratio of silicon oxide SiO ₂ which is a component of silicate and alkali metal oxide M ₂ O (generally expressed as a molar ratio of [SiO ₂ ] / [M ₂ O]. ) And the density, the developability can be adjusted. For example, as disclosed in JP-A-54-62004, the SiO ₂ / Na ₂ O molar ratio is 1.0 to 1.5 (that is, [SiO ₂ ] / [Na ₂ O] is 1.0 to 1.5), and an aqueous solution of sodium silicate having a SiO ₂ content of 1 to 4% by weight is disclosed in JP-B-57-7427. As described, [SiO ₂ ] / [M] is 0.5 to 0.75 (ie, [SiO ₂ ] / [M ₂ O] is 1.0 to 1.5), and SiO ₂ And the developer is based on gram atoms of all alkali metals present therein. A manner containing potassium at least 20%, aqueous solution of an alkali metal silicate is preferably used.

In addition, a so-called “non-silicate developer” that does not contain an alkali silicate and contains a non-reducing sugar and a base can also be suitably used. In this case, it is preferable to contain a non-reducing sugar having a buffering property that suppresses fluctuations in pH. Non-reducing sugars are saccharides that do not have a free aldehyde group or ketone group and do not exhibit reducibility, trehalose-type oligosaccharides in which reducing groups are bonded, and glycosides in which reducing groups of saccharides are combined with non-saccharides. , And sugar alcohols reduced by hydrogenation of sugars, any of which can be used in the present invention. In the present invention, non-reducing sugars described in JP-A-8-305039 can be preferably used.
Examples of the trehalose type oligosaccharides include saccharose and trehalose. Examples of the glycoside include alkyl glycosides, phenol glycosides, and mustard oil glycosides. Examples of the sugar alcohol include D, L-arabit, rebit, xylit, D, L-sorbit, D, L-mannit, D, L-exit, D, L-talit, zulsiit, allozulcit and the like. . Further, maltitol hydrogenated to disaccharide maltose, reduced form obtained by hydrogenation of oligosaccharide (reduced water candy), and the like are preferable. Among these non-reducing sugars, trehalose-type oligosaccharides and sugar alcohols are preferable, and among them, D-sorbitol, saccharose, reduced syrup, etc. are preferable in that they have a buffering action in an appropriate pH region and are inexpensive.

  These non-reducing sugars may be used alone or in combination of two or more. The content of the non-reducing sugar in the non-silicate developer is preferably 0.1 to 30% by weight, and more preferably 1 to 20% by weight. When the content is within the above range, an appropriate buffer action is obtained.

Examples of the base used in combination with the non-reducing sugar include conventionally known alkali agents such as inorganic alkali agents and organic alkali agents. Examples of the inorganic alkaline agent include sodium hydroxide, potassium hydroxide, lithium hydroxide, trisodium phosphate, tripotassium phosphate, triammonium phosphate, disodium phosphate, dipotassium phosphate, diammonium phosphate, Examples thereof include sodium carbonate, potassium carbonate, ammonium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, ammonium hydrogen carbonate, sodium borate, potassium borate, and ammonium borate.
Examples of the organic alkali agent include monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanol. Examples include amine, diisopropanolamine, ethyleneimine, ethylenediamine, and pyridine.

The said base may be used individually by 1 type, and may use 2 or more types together. Among these bases, sodium hydroxide and potassium hydroxide are preferable. In the present invention, as the non-silicate developer, a non-reducing sugar alkali metal salt as a main component can be used instead of the non-reducing sugar and the base.
In addition, an alkaline buffer composed of a weak acid other than the non-reducing sugar and a strong base can be used in combination with the non-silicate developer. The weak acid preferably has a dissociation constant (pKa) of 10.0 to 13.2, and can be selected from, for example, those described in Ionization Constants of Organic Acids Solution, published by Pergmon Press.
Specifically, alcohols such as 2,2,3,3-tetrafluoropropanol-1, trifluoroethanol, and trichloroethanol, pyridine-2-aldehyde (, aldehydes such as pyridine-4-aldehyde (such as salicylic acid, 3-hydroxy-2-naphthoic acid, catechol, gallic acid, sulfosalicylic acid, 3,4-dihydroxysulfonic acid, 3,4-dihydroxybenzoic acid, hydroquinone (11.56), pyrogallol, o-, m-, p -Compounds having a phenolic hydroxyl group such as cresol, resorsonol, oximes such as acetoxime, 2-hydroxybenzaldehyde oxime, dimethylglyoxime, ethanediamide dioxime, acetophenone oxime, adenosine, inosine, guanine, cytosine, hypoxanthine, chitosan Nucleic acid-related substances such as Nchin, other, diethylaminomethyl acid, benzimidazole, and the like barbituric acid is preferably exemplified.

In the developer and replenisher, various surfactants and organic solvents are added as necessary for the purpose of promoting and suppressing developability, dispersing development residue, or improving ink affinity of the printing plate image area. it can. As the surfactant, anionic, cationic, nonionic and amphoteric surfactants are preferable. Further, the developer and replenisher may contain a reducing agent such as sodium salt and potassium salt of inorganic acids such as hydroquinone, resorcin, sulfurous acid, and bisulfite, as well as organic carboxylic acid, antifoaming agent, hard water, if necessary. Softeners and the like can be added.
The image forming material developed using the developer and the replenisher is post-processed with a desensitizing solution containing washing water, a rinsing solution containing a surfactant or the like, gum arabic or a starch derivative. As the post-treatment when the image forming material is used as a printing plate, these treatments can be used in various combinations.

Further, when developing using an automatic developing machine, an aqueous solution (replenisher) having a higher alkali strength than that of the developer is added to the developer, so that a large amount of developer can be obtained without replacing the developer in the developer tank for a long time. It is known that PS plates can be processed. This replenishment method is also preferably applied in the present invention.
The printing plate developed using the developer and the replenisher is post-treated with water-washing water, a rinsing solution containing a surfactant and the like, a desensitizing solution containing gum arabic and starch derivatives. As the post-treatment of the lithographic printing plate precursor using the photosensitive composition of the present invention, these treatments can be used in various combinations.

In recent years, automatic developing machines for printing plates have been widely used in the plate making and printing industries in order to rationalize and standardize plate making operations. This automatic developing machine is generally composed of a developing unit and a post-processing unit, and includes an apparatus for transporting the printing plate, each processing liquid tank and a spray device, and each pumped up by a pump while transporting the exposed printing plate horizontally. The processing liquid is sprayed from the spray nozzle and developed. In addition, recently, a method is also known in which a printing plate is dipped and conveyed by a submerged guide roll or the like in a processing liquid tank filled with the processing liquid. In such automatic processing, each processing solution can be processed while being supplemented with a replenisher according to the processing amount, operating time, and the like. In addition, a so-called disposable processing method in which processing is performed with a substantially unused processing solution can also be applied.
In the lithographic printing plate precursor using the photosensitive composition of the present invention, an image portion unnecessary for the lithographic printing plate obtained by image exposure, development, washing and / or rinsing and / or gumming (for example, If there is a film edge mark of the original image film, the unnecessary image portion is erased. Such erasing is preferably performed by applying an erasing solution as described in, for example, Japanese Patent Publication No. 2-13293 to an unnecessary image portion, leaving it for a predetermined time, and then washing with water. As described in JP-A-59-174842, a method of developing after irradiating an unnecessary image portion with an actinic ray guided by an optical fiber can also be used.

  The lithographic printing plate obtained as described above can be subjected to a printing process after applying a desensitized gum if desired. However, if it is desired to make a lithographic printing plate with a higher printing durability, if desired, Burning process is performed.

In the case of burning a lithographic printing plate, before burning, an adjustment as described in JP-B-61-2518, JP-A-55-28062, JP-A-62-31859, JP-A-61-159655 is used. It is preferable to treat with a surface liquid.
As its method, with a sponge or absorbent cotton soaked with the surface-adjusting liquid, it is applied onto a lithographic printing plate, or a method in which the printing plate is immersed and applied in a vat filled with the surface-adjusting liquid, Application by an automatic coater is applied. Further, it is more preferable to make the coating amount uniform with a squeegee or a squeegee roller after coating.

In general, the amount of surface-adjusting solution applied is suitably 0.03 to 0.8 g / m ² (dry mass). The lithographic printing plate coated with the surface-adjusting solution is dried if necessary, and then heated to a high temperature with a burning processor (for example, burning processor “BP-1300” sold by Fuji Photo Film Co., Ltd.). The In this case, the heating temperature and time are in the range of 180 to 300 ° C. and preferably in the range of 1 to 20 minutes, although depending on the type of components forming the image.
The lithographic printing plate that has been burned can be subjected to conventional treatments such as washing and gumming as needed, but a surface-conditioning solution containing a water-soluble polymer compound is used. In such a case, a so-called desensitizing treatment such as gumming can be omitted. The planographic printing plate obtained by such processing is applied to an offset printing machine or the like and used for printing a large number of sheets.

  EXAMPLES Hereinafter, although this invention is demonstrated according to an Example, the scope of the present invention is not limited to these Examples.

[Example 1]
The support body was produced by processing through the process shown below using a JIS-A-1050 aluminum plate with a thickness of 0.3 mm.
The aluminum plate was sprayed with an aqueous NaOH solution (concentration: 26 wt%, aluminum ion concentration: 6.5 wt%) at a temperature of 70 ° C. to dissolve the aluminum plate by 6 g / m ² . Thereafter, washing with water was performed using well water.
Next, desmutting treatment was performed by spraying with an aqueous solution of nitric acid having a concentration of 1% by weight (containing 0.5% by weight of aluminum ions) at a temperature of 30 ° C., and then washed with water by spraying.
An electrochemical surface roughening treatment was continuously performed using an alternating voltage of 60 Hz. The electrolytic solution at this time was a hydrochloric acid 7.5 g / liter aqueous solution (containing 5 g / liter of aluminum ions) at a temperature of 35 ° C. The AC power supply waveform was a rectangular wave, and an electrochemical surface roughening treatment was performed using a carbon electrode as a counter electrode. Ferrite was used for the auxiliary anode. The electrolytic cell used was a radial cell type.

The current density was 25 A / dm ² at the peak current value, and the amount of electricity was 450 C / dm ² in terms of the total amount of electricity when the aluminum plate was the anode.
Thereafter, washing with water was performed using well water.
The aluminum plate was spray-etched at 32 ° C. with a caustic soda concentration of 26% by weight and an aluminum ion concentration of 6.5% by weight, and the aluminum plate was dissolved at 0.10 g / m ^2. The smut component mainly composed of aluminum hydroxide generated during the roughening treatment was removed, and the edge portion of the generated pit was melted to smooth the edge portion. Thereafter, washing with water was performed using well water.
The desmutting treatment was performed by spraying with an aqueous solution having a sulfuric acid concentration of 25% by weight (containing 0.5% by weight of aluminum ions) at a temperature of 60 ° C., and then washed with water using well water.

Subsequently, anodizing treatment was performed. The electrolytic solution had a sulfuric acid concentration of 170 g / liter (containing 0.5% by weight of aluminum ions) and a temperature of 43 ° C. Thereafter, washing with water was performed using well water.
Both current densities were about 30 A / dm ² . The final oxide film amount was 2.7 g / m ² .

Further, an anodized aluminum plate was immersed for 5 seconds in a solution obtained by heating a 0.5% polyvinylphosphonic acid aqueous solution to 60 ° C., and washed with water by spraying.
Thus, a support for a photosensitive lithographic printing plate was obtained.
On the hydrophilic surface of the support obtained above, a photosensitive layer coating solution A having the following composition was coated with a wire bar, and then dried for 50 seconds in a drying oven set at 140 ° C. to obtain a photosensitive layer. . The coating amount after drying was 1.5 g / m ² .

<Coating solution A for photosensitive layer>
The melting point of 1-butyl-3-methylimidazolium tetrafluoroborate, which is an onium salt, is -75 ° C.
-Copolymer of vinylpyrrolidone / vinyl acetate / vinyl alcohol = 60/38/2 (molar ratio) (1) (weight average molecular weight 20,000) 0.80 g
・ 1-butyl-3-methylimidazolium tetrafluoroborate 0.03 g
・ Cyanine dye P 0.15 g with the following structure

・ Ethyl violet 0.05g
・ Methyl ethyl ketone 5.00g
・ 1-methoxy-2-propanol 5.00g
・ N, N-dimethylformamide 10.00g
In this way, a photosensitive lithographic printing plate (A) was obtained.

[Example 2]
In Example 1, instead of copolymer (1) of the photosensitive layer, copolymer (2) (weight average molecular weight 40,000) of N-vinylimidazole / vinyl acetate = 80/20 (molar ratio) was used. A photosensitive lithographic printing plate (I) was obtained in the same manner as in Example 1 except that.

[Example 3]
In Example 1, instead of the copolymer (1) of the photosensitive layer, 0.40 g of polyvinylpyrrolidone (weight average molecular weight 10,000) and m-cresol / p-cresol = 60 / 40 (molar ratio) novolak resin (1) (weight average molecular weight 5,000) 0.30 g, N- (p-aminosulfonylphenyl) methacrylamide / methyl methacrylate / acrylonitrile = 35/35/30 (molar ratio) ) Copolymer (3) (weight average molecular weight 65,000) was added in the same manner as in Example 1 except that a photosensitive lithographic printing plate (U) was obtained.

[Example 4]
In Example 1, the amount of copolymer (1) in the photosensitive layer was 0.70 g, 0.10 g of novolak resin (1) was added as the other polymer compound, and 1-butyl-3-methylimidazo was added. A photosensitive lithographic printing plate (E) was obtained in the same manner as in Example 1 except that 0.05 g of 1-methyl-3-octylimidazolium tetrafluoroborate was used in place of lithium tetrafluoroborate. The melting point of 1-methyl-3-octylimidazolium tetrafluoroborate is -88 ° C.

[Example 5]
In Example 1, instead of the copolymer (1) of the photosensitive layer, the copolymer (4) (weight average molecular weight 50,000) of vinyl acetal / vinyl acetate / vinyl alcohol = 70/25/5 (molar ratio). ) 0.30 g, m-cresol / p-cresol / phenol = 30/20/50 (molar ratio) novolak resin (2) (weight average molecular weight 8,000) 0.50 g, respectively, and 1 A photosensitive lithographic printing plate (O) was obtained in the same manner as in Example 1 except that 0.08 g of -butyl-3-methylimidazolium tetrafluoroborate (75 ° C.) was used.

[Example 6]
After obtaining a support in the same manner as in Example 1, a lower layer coating solution B having the following composition was applied on the hydrophilic surface of the obtained support with a wire bar, and then a drying oven set at 140 ° C. And dried for 50 seconds to obtain a lower layer. The coating amount after drying was 1.2 g / m ² .

<Lower layer coating solution B>
・ Copolymer (1) 0.80g
・ The cyanine dye P 0.15 g
・ Ethyl violet 0.05g
・ Methyl ethyl ketone 5.00g
・ 1-methoxy-2-propanol 5.00g
・ N, N-dimethylformamide 10.00g
On the lower layer thus obtained, an upper layer coating solution C having the following composition was coated with a wire bar, and then dried in a drying oven set at 130 ° C. for 60 seconds to obtain an upper layer. The coating amount after drying was 0.4 g / m ² .

<Upper layer coating solution C>
・ Novolac resin (1) 0.95g
・ 1-butyl-3-methylimidazolium tetrafluoroborate 0.10 g
・ Cyanine dye P 0.05g
・ Methyl ethyl ketone 10.00g
1-methoxy-2-propanol 10.00g
In this way, a photosensitive lithographic printing plate (ka) was obtained.

[Example 7]
In Example 6, instead of the lower layer copolymer (1), a copolymer (5) (weight average molecular weight 10,000) of vinylimidazole / vinylpyrrolidone = 50/50 (molar ratio) was used. In the same manner as in Example 6, a photosensitive lithographic printing plate (ki) was obtained.

[Example 8]
In Example 6, instead of the lower layer copolymer (1), 0.70 g of the aforementioned copolymer (4) and 0.10 g of the aforementioned novolac resin (1) were used, respectively, In addition to using novolak resin (2) instead of novolak resin (1) and 0.08 g of 1-methyl-3-octylimidazolium tetrafluoroborate instead of 1-butyl-3-methylimidazolium tetrafluoroborate Was the same as in Example 1 to obtain a photosensitive lithographic printing plate.

[Comparative Example 1]
In Example 1, instead of the copolymer (1) of the photosensitive layer, a copolymer of N-phenylmaleimide / methacrylamide / methacrylic acid = 45/35/20 (molar ratio) as a polymer compound (weight average molecular weight) 50,000) was used in the same manner as in Example 1 to obtain a photosensitive lithographic printing plate.

[Comparative Example 2]
A photosensitive lithographic printing plate was obtained in the same manner as in Example 1 except that 1-butyl-3-methylimidazolium tetrafluoroborate was not added.

[Comparative Example 3]
In Example 8, except that 1-butyl-3-methylimidazolium tetrafluoroborate was not added, a photosensitive lithographic printing plate (SA) was obtained in the same manner as in Example 1.

[Evaluation of chemical resistance]
The obtained photosensitive planographic printing plates (A) to (SA) were subjected to a Trendsetter 3244 manufactured by Creo Corporation under conditions of a beam intensity of 10.0 W and a drum rotation speed of 250 rpm, and a dot area ratio of 175 lpi / 2400 dpi 1 to 99%. The test pattern containing the above chart was drawn (exposure) on an image.
Next, using a PS processor LP-940HII manufactured by Fuji Photo Film Co., Ltd., a lithographic printing plate was obtained by performing a developing process and a gumming process at a developing solution temperature of 30 degrees and a developing time of 12 seconds. At this time, as a developing solution, a solution obtained by diluting Fuji Photo Film Co., Ltd. developer DT-2 1: 8 with water, and as a gum solution, Fuji Photo Film Co., Ltd. FG-1 with water. A solution diluted 1: 1 was used.

Printing was performed using the lithographic printing plate thus obtained. At this time, Lilithon printing machine manufactured by Komori Corporation was used as the printing machine, Varius G ink ink manufactured by Dainippon Ink & Chemicals, Inc. as the ink, and Fuji Photo Film Co., Ltd. as the dampening water. Using IF-102 made by diluting IF-102 made with water to a concentration of 4%, and each time 5000 sheets were printed, part of the image was wiped with a multi-cleaner made by Fuji Photo Film Co., Ltd. It was. Depending on the number of copies printed when printing on high-quality paper and the solid image density began to fade, the printing durability (the part where the plate surface was not wiped with a cleaner) and chemical resistance (the plate surface was wiped with a cleaner) Were evaluated. Larger values mean better printing durability and chemical resistance. The results are shown in Table 1.
As shown in Table 1, the photosensitive lithographic printing plates (A) to (K) satisfying the requirements of the present application exhibited good chemical resistance. On the other hand, the photosensitive lithographic printing plates (ke) to (sa) were inferior in printing durability and chemical resistance.

[Evaluation of scratch resistance]
The obtained photosensitive lithographic printing plates (A) to (SA) were rubbed by 15 revolutions with an Ablaser felt CS5 to which a load of 250 g was applied, using a rotary ablation tester manufactured by TOYOSEIKI.
Next, this plate was subjected to development processing in the same manner as in the evaluation of developability described above except that the above-described developer 1 was used as a developer. The plate thus obtained was subjected to measurement of the density of the plate surface with a Macbeth densitometer on the part subjected to friction and the part not subjected to friction, and the absolute value of the difference was calculated. The results are shown in Table 1. The larger the value, the greater the damage to the plate due to friction.

  As shown in Table 1, the photosensitive lithographic printing plates (A) to (K) satisfying the requirements of the present application have small values, indicating good scratch resistance. The photosensitive lithographic printing plates (ke) to (sa) have large values, indicating poor scratch resistance.

As shown in the above examples, by carrying out the present invention, a photosensitive lithographic printing plate having excellent printing durability, chemical resistance and scratch resistance could be obtained.

Claims (2)

A photosensitive lithographic printing plate for an infrared laser in which a photosensitive layer containing at least a polymer compound and an infrared absorber is provided on the hydrophilic surface of a support having a hydrophilic surface,
The photosensitive layer further contains an onium salt having a melting point of 80 ° C. or less,
The polymer compound contained in the photosensitive layer contains at least a vinyl polymer, and the vinyl polymer comprises at least one selected from the group consisting of the following (A), (B) and (C): A photosensitive lithographic printing plate for infrared laser, characterized in that it is a structural unit.
(A) A structural unit derived from a monomer in which a saturated cyclic group containing a carbonyl group as a ring constituent group is directly bonded to a vinyl group, and the cyclic group may have a hetero atom as a ring constituent atom.
(B) a structural unit derived from a monomer in which an unsaturated cyclic group containing at least one nitrogen atom as a ring constituent atom is directly bonded to a vinyl group, wherein the cyclic group contains one of the nitrogen atoms as C—N ═C bond.
(C) A structural unit derived from vinyl acetals. On the hydrophilic surface of the support having a hydrophilic surface, a lower layer containing at least a polymer compound and an infrared absorber, and an upper layer containing at least another polymer compound different from the polymer compound of the lower layer Is a photosensitive lithographic printing plate for infrared laser having at least in this order,
The upper layer further contains an onium salt having a melting point of 80 ° C. or lower,
The polymer compound contained in the lower layer contains at least a vinyl polymer, and the vinyl polymer contains at least one selected from the group consisting of the following (A), (B) and (C) as a structural unit. A photosensitive lithographic printing plate for infrared lasers, characterized in that
(A) A structural unit derived from a monomer in which a saturated cyclic group containing a carbonyl group as a ring constituent group is directly bonded to a vinyl group, and the cyclic group may have a hetero atom as a ring constituent atom.
(B) a structural unit derived from a monomer in which an unsaturated cyclic group containing at least one nitrogen atom as a ring constituent atom is directly bonded to a vinyl group, wherein the cyclic group contains one of the nitrogen atoms as C—N ═C bond.
(C) A structural unit derived from vinyl acetals.