JP2005249825A - Developer for photosensitive lithographic printing plate and platemaking method for lithographic printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an alkaline developer capable of forming a high sharpness clear image without causing defects to an image area and capable of suppressing production of development scum due to photosensitive layer components of a photosensitive lithographic printing plate, and to provide a platemaking method for a lithographic printing plate. <P>SOLUTION: The alkaline developer for a photosensitive lithographic printing plate contains an alkylene oxide adduct of a carboxylic acid alkanol amide. Alternatively, the alkaline developer for a photosensitive lithographic printing plate contains an alkylene oxide adduct of a fatty acid alkanol amide shown by a specified formula. The platemaking method for a lithographic printing plate includes development of a photosensitive lithographic printing plate with the alkaline developer after exposure. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an alkaline developer used for a photosensitive lithographic printing plate, and further relates to a method for making a lithographic printing plate using the alkaline developer.

In recent years, the development of lasers has been remarkable, and in particular, solid lasers and semiconductor lasers with a light emitting region from the near infrared to the infrared are easily available in high output and small size. These lasers are very useful as exposure light sources for systems that do this.
As an image recording material suitable for laser writing, for example, a binder such as cresol resin, a substance that absorbs light and generates heat, and is thermally decomposable such as quinonediazide, and in the state before decomposition, A positive-type image recording material containing a compound capable of substantially reducing the solubility of the binder has been proposed (for example, see Patent Document 1).
This is a substance that generates heat by absorbing the light in the exposed part by infrared irradiation, and makes the exposed part alkali-soluble (heat mode type), but is absorbed by aluminum as a support. Therefore, the thermal efficiency is low, and the solubility in an alkaline developer in the development process is not satisfactory. For this reason, the alkali concentration of a developing solution was raised and the solubility of the exposed part was ensured.

However, the heat mode type lithographic printing plate precursor has a low solubility resistance against the alkaline developer in the image area under the high concentration alkaline conditions as described above, and is dissolved only with slight scratches on the surface of the image recording material. There are problems such as defects in the image area. In particular, the tendency was more remarkable in a positive type lithographic printing plate precursor using a polymer compound that is highly soluble in an alkaline aqueous solution.
Therefore, there is a limit to increasing the alkali concentration of the alkali developer so that no residual film is formed in the non-image area, and it is difficult to form a sharp and clear image without causing defects in the formed image area. Met. In particular, in a fine image including a dot portion and a thin line, it is required to increase the sharpness and improve the reproducibility. For this reason, it has been studied to add various surfactants to the developer, and a certain degree of improvement has been obtained regarding high image sharpness.

  In addition, with recent improvements in infrared laser exposure type image recording materials, compared to conventional infrared absorbing dyes, it is difficult to dissolve in an alkaline developer, for example, infrared absorbing dyes such as cyanine dyes tend to be used, When this image recording material is developed with an alkaline developer, the insoluble matter of the infrared absorbing dye tends to be discharged into the developing solution. This causes further insoluble matter to form due to interaction with the binder polymer components and inorganic substances in the water, and as the development process continues, these insoluble matter accumulates and aggregates to form development debris, which makes development processing inefficient. It becomes a factor to stabilize. Specifically, these insoluble substances adhere to the plate and cause troubles in the image, or precipitate and precipitate in the development processing bath, causing a burden on the maintenance of the processing bath. Under such circumstances, for example, when a burning process is performed with the development residue adhering on the non-image area, there is a disadvantage that the remaining film is carbonized and becomes dirty during printing.

In view of such problems, it has been proposed to include an alkylene oxide adduct of alkylenediamine in the developer (see, for example, Patent Document 2 and Patent Document 3), and an anion as a hydrotropic agent in the developer. It has been proposed to include a surfactant and an amphoteric surfactant (see, for example, Patent Document 4), and in addition, it has been proposed to include a specific amphoteric surfactant in a developer (for example, Patent Document). 5). However, it has not yet been fully resolved.
Therefore, it avoids inconvenience due to insoluble matter caused by image recording layer components such as infrared absorbing dye, and forms a high-sharp and clear image without giving defects to the formed image portion. In high-definition images including the above, high sharpness and improvement in reproducibility are required.
On the other hand, in the field of liquid detergents, liquid detergent compositions excellent in soap scum dispersibility including specific surfactants have been proposed (see, for example, Patent Documents 6 to 9).

JP-A-7-285275 European Patent Application No. 1081554 JP-A-60-129750 European Patent Application No. 908785 JP 2002-72501 A JP-A-6-330086 JP-A-10-330786 JP-A-5-295399 JP 11-293289 A

  The present invention solves various problems in the prior art, can form a sharp and clear image without causing defects in the image area, and suppresses the occurrence of development residue due to the photosensitive layer components of the photosensitive lithographic printing plate. It is an object of the present invention to provide an alkaline developer that can be used and a method for making a lithographic printing plate.

（式中、Ｒ¹は炭素原子数３〜２１の炭化水素基を表し、Ｒ²は水素原子、炭素原子数１〜３のアルキル基、又は-(Ｂ-Ｏ)m-Ｈ（Ｂ-Ｏはオキシエチレン基、オキシプロピレン基、オキシブチレン基及びオキシスチレン基から選ばれる少なくとも１つの基を表し、ｍは１〜１００の整数を表す。）を表し、Ａ-Ｏはオキシエチレン基、オキシプロピレン基、オキシブチレン基及びオキシスチレン基から選ばれる少なくとも１つの基をあらわし、ｎは１〜１００の整数を表す。） As a result of intensive studies in order to achieve the above-mentioned problems, the inventors of the present invention can form a sharp and clear image by containing a specific compound in an alkaline developer, and insoluble due to photosensitive layer components. The present inventors have found that it is possible to satisfactorily disperse the product and suppress the development debris from being generated, and the present invention has been completed.
Accordingly, the present invention is an alkaline developer for a photosensitive lithographic printing plate containing an alkylene oxide adduct of a carboxylic acid alkanolamide.
More specifically, the present invention is an alkaline developer for a photosensitive lithographic printing plate comprising at least one compound represented by the following general formula (I).

(Wherein R ¹ represents a hydrocarbon group having 3 to 21 carbon atoms, and R ² represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or — (B—O) m—H (B—O Represents at least one group selected from an oxyethylene group, an oxypropylene group, an oxybutylene group, and an oxystyrene group, m represents an integer of 1 to 100), and A-O represents an oxyethylene group and an oxypropylene group. Represents at least one group selected from a group, an oxybutylene group and an oxystyrene group, and n represents an integer of 1 to 100.)

The present invention is also directed to a method for making a lithographic printing plate using the alkaline developer. Accordingly, the present invention is also a plate making method of a lithographic printing plate comprising developing a photosensitive lithographic printing plate with the above alkaline developer after exposure.
The photosensitive lithographic printing plate to which the alkaline developer of the present invention can be applied is not particularly limited, and various photosensitive lithographic printings in which an image recording layer such as a photosensitive layer and a heat-sensitive layer is provided on a support. You can list the version. The alkaline developer of the present invention is particularly preferably used for plate making from an infrared-sensitive lithographic printing plate. Therefore, the present invention also provides the above lithographic printing plate, wherein the photosensitive lithographic printing plate has a photosensitive layer on a support, and the photosensitive layer is an infrared photosensitive lithographic printing plate containing an infrared absorbing dye and an alkali-soluble resin. It is directed to the plate making method.

  According to the alkaline developer of the present invention, it is possible to satisfactorily disperse the insoluble matter resulting from the components in the photosensitive layer to suppress development debris, prevent the development debris from adhering to the plate surface, The photosensitive lithographic printing plate can be stably developed. According to the plate making method of the lithographic printing plate of the present invention, it is possible to form a sharp and clear image with an edge tone without causing image defects in the image area while maintaining developability.

Hereinafter, the present invention will be described in detail.
First, the alkaline developer of the present invention will be described. The alkaline developer of the present invention can be used as a developer charged at the start of development (referred to as a development starter) or a development replenisher. Hereinafter, unless otherwise specified, the development starter and the development replenisher are collectively referred to as a developer.
The developing solution of the present invention has an alkaline aqueous solution as a basic composition, and can be appropriately selected from conventionally known alkaline aqueous solutions.
Examples of the alkaline aqueous solution include a developer composed of an alkali silicate or non-reducing sugar and a base, and those having a pH of 12.5 to 14.0 are particularly preferable.
The alkali silicate exhibits alkalinity when dissolved in water, and examples thereof include alkali metal silicates such as sodium silicate, potassium silicate and lithium silicate, and ammonium silicate.
The alkali silicate may be used alone or in combination of two or more.

The alkali aqueous solution is easy to develop by adjusting the mixing ratio and concentration of silicon oxide SiO ₂ and alkali oxide M ₂ O (M represents an alkali metal or ammonium group), which is a silicate component. Can be adjusted to.
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 preferably in this range. In addition, a general-purpose aluminum plate is rarely etched as a support for a lithographic printing plate, and developability is good. SiO ₂ / M ₂ O (molar ratio) is more preferably 1.0 to 2.0.

  The concentration of the alkali silicate in the developer is preferably 1 to 10% by mass, and 3 to 8% by mass with respect to the mass of the aqueous alkali solution, from the viewpoint of good developability and processing capability and convenience of waste liquid treatment. More preferably, 4 to 7% by mass is most preferable.

In a developer comprising a non-reducing sugar and a base, the non-reducing sugar means a saccharide that has no free aldehyde group or ketone group and therefore has no reducing property, and is a trehalose-type oligosaccharide in which reducing groups are bonded to each other. Glycosides in which saccharide reducing groups and non-saccharides are combined, and sugar alcohols reduced by hydrogenation of saccharides. Any of these can be suitably used in the present invention.
Examples of trehalose type oligosaccharides include saccharose and trehalose, and 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-digit, D, L-talit, dulcit, allozulcit, meso-inosit and the like. . Furthermore, maltitol obtained by hydrogenation of a disaccharide, a reduced form (reduced water candy) obtained by hydrogenation of an oligosaccharide, and the like can also be suitably exemplified.

Among the above, as the non-reducing sugar, sugar alcohol and saccharose are preferable, and among them, D-sorbite, meso-inosit, saccharose, and reduced starch syrup are more preferable because they have a buffering action in an appropriate pH range.
These non-reducing sugars may be used alone or in combination of two or more. The proportion of the non-reducing sugar in the developer is preferably 0.1 to 30% by mass, more preferably 1 to 20% by mass.

In the alkali silicate or non-reducing sugar, an alkali agent as a base can be appropriately selected from conventionally known compounds and combined.
Examples of the alkali agent include sodium hydroxide, potassium hydroxide, lithium hydroxide, trisodium phosphate, tripotassium phosphate, triammonium phosphate, disodium phosphate, dipotassium phosphate, diammonium phosphate, carbonic acid. Inorganic alkaline agents such as sodium, potassium carbonate, ammonium carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, sodium borate, potassium borate, ammonium borate, potassium citrate, tripotassium citrate, sodium citrate, etc. Is mentioned.

Furthermore, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, n-butylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, ethylene An organic alkali agent such as imine, ethylenediamine, pyridine and the like can also be suitably exemplified.
These alkaline agents may be used alone or in combination of two or more.
Of these, sodium hydroxide and potassium hydroxide are preferred. The reason is that the pH can be adjusted in a wide pH range by adjusting the amount added to the non-reducing sugar. Further, trisodium phosphate, tripotassium phosphate, sodium carbonate, potassium carbonate and the like are preferable because they have a buffering action.

（式中、Ｒ¹は炭素原子数４〜３２の炭化水素基を表し、Ｒ²は水素原子又は炭素原子数１〜３のアルキル基、又は-(Ｂ-Ｏ)m-Ｈ（Ｂ-Ｏはオキシエチレン基、オキシプロピレン基、オキシブチレン基及びオキシスチレン基から選ばれる少なくとも１つの基を表し、ｍは１〜１００の整数を表す。）を表し、Ａ-Ｏはオキシエチレン基、オキシプロピレン基、オキシブチレン基及びオキシスチレン基から選ばれる少なくとも１つの基を表し、ｎは１〜１００の整数を表す。） The alkaline developer of the present invention contains an alkylene oxide adduct of a carboxylic acid alkanolamide. Examples of the alkylene oxide adduct of the carboxylic acid alkanolamide include those represented by the following general formula (I).
Therefore, the alkaline developer of the present invention more specifically contains at least one compound represented by the following general formula (I).

(Wherein R ¹ represents a hydrocarbon group having 4 to 32 carbon atoms, R ² represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, or — (B—O) m—H (B—O Represents at least one group selected from an oxyethylene group, an oxypropylene group, an oxybutylene group and an oxystyrene group, m represents an integer of 1 to 100), and A-O represents an oxyethylene group and an oxypropylene group. Represents at least one group selected from a group, an oxybutylene group and an oxystyrene group, and n represents an integer of 1 to 100.)

In the general formula (I), R ¹ represents a hydrocarbon group having 4 to 32 carbon atoms, such as a saturated or unsaturated aliphatic hydrocarbon group having 4 to 32 carbon atoms, such as an alkyl group, an alkenyl group, Represents an aralkyl group, a cycloalkyl group, a cycloalkenyl group, etc., and these aliphatic hydrocarbon groups may be linear, branched or cyclic, or an aromatic hydrocarbon group having 6 to 32 carbon atoms, for example, An aryl group (phenyl group, naphthyl group, anthryl group, etc.) and an alkylaryl group are represented.
In the formula, R ¹ may be derived from a saturated or unsaturated fatty acid, and R ¹ represents, for example, a saturated or unsaturated aliphatic hydrocarbon group having 4 to 32 carbon atoms, preferably 5 to 17 carbon atoms. And R ¹ — (CO) — may be a residue of a saturated or unsaturated fatty acid having 6 to 22 carbon atoms, preferably 6 to 18 carbon atoms. R ^1- (CO) — includes, for example, residues such as caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, stearic acid, behenic acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid, coconut oil Examples include fatty acid residues, rice bran oil fatty acid residues, cottonseed oil fatty acid residues, rapeseed oil fatty acid residues, soybean oil fatty acid residues, beef tallow fatty acid residues, and tallow fatty acid residues.

In the formula, R ² represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, or — (B—O) m—H (B—O represents an oxyethylene group, an oxypropylene group, an oxybutylene group, and an oxystyrene group. Represents at least one selected group, and m represents an integer of 1 to 100).
Among the compounds represented by the above general formula (I), in particular, R ² is — (B—O) mH (B—O is selected from oxyethylene group, oxypropylene group, oxybutylene group and oxystyrene group) And a compound represented by m represents an integer of 1 to 100. Here, when — (B—O) m is composed of two or more groups selected from an oxyethylene group, an oxypropylene group, an oxybutylene group and an oxystyrene group, the form thereof may be a block form or a random form. m is preferably an integer of 5 to 100, more preferably an integer of 5 to 50, and still more preferably an integer of 5 to 20.

  In the general formula (I), A—O represents at least one group selected from an oxyethylene group, an oxypropylene group, an oxybutylene group, and an oxystyrene group, and n represents an integer of 1-100. In the formula, when-(A-O) n- is composed of two or more groups selected from an oxyethylene group, an oxypropylene group, an oxybutylene group and an oxystyrene group, the form may be block or random. n is preferably an integer of 5 to 100, more preferably an integer of 5 to 50, and still more preferably an integer of 5 to 20.

（Ｐｈはフェニル基を表す。） Specific examples of the B-O or A-O include the following.

(Ph represents a phenyl group.)

The compound represented by the above general formula (I) usually contains a carboxylic acid having a hydrocarbon group corresponding to R ¹ or a lower alkyl ester thereof and a monoalkanolamine having a group corresponding to R ^2. It can be made to react by the method, and thereafter, it is produced by addition polymerization of ethylene oxide or the like by a conventional method.
Examples of monoalkanolamines include N-monoethanolamine, N-methyl-N-monoethanolamine, N-ethyl-N-monoethanolamine, and N-propyl-N-monoethanolamine. In addition, dialkanolamines can be used in the reaction for the production of a compound in which R ² represents the above-(BO) mH.

Examples of fatty acids used in the production of the compound represented by the general formula (I) include caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, stearic acid, behenic acid, oleic acid, linoleic acid, and linolenic acid. There are fatty acids of 4 to 23 carbon atoms including acids, arachidonic acid and the like. These fatty acids may be used alone or as mixed fatty acids. Examples of the raw material of the mixed fatty acid include coconut oil, rice bran oil, cottonseed oil, rapeseed oil, soybean oil, palm oil, palm kernel oil, peanut oil, safflower oil, sunflower oil, beef tallow, and pork fat.
The compound represented by the general formula (I) can be produced, for example, according to the method disclosed in JP-A-6-330086.

The developer of the present invention may contain the compound represented by the general formula (I) alone or in combination of two or more.
In the developer of the present invention, the content of the compound represented by the general formula (I) is appropriately 0.001 to 10.0% by mass, preferably 0.01 to 1.0% by mass, and more preferably Is 0.05-0.5 mass%.

As described above, a developer containing an alkali silicate or non-reducing sugar and a base is used as the alkaline developer, and Li ⁺ , Na ⁺ , K ⁺ , and NH ⁴⁺ are conventionally used as the cation component. A system containing a large number of cations having a small ionic radius has high penetrability into the image recording layer and excellent developability, but dissolves up to the image area to cause image defects. Therefore, there is a certain limit to increasing the alkali concentration, and in order to completely process the image recording layer (residual film) so as not to remain in the non-image area without causing defects in the image area, it is delicate. It was required to set a proper liquid condition.
However, by using a cation having a large ionic radius as the cation component, the penetrability of the developer into the image recording layer can be suppressed, and the image density can be reduced without reducing the alkali concentration, that is, the developability. The dissolution inhibiting effect of the part can also be improved.
As the cation component, in addition to the alkali metal cation and ammonium ion, other cations can be used.

The usage mode of the developer of the present invention is not particularly limited.
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. The developer of the present invention can be used for development processing by an automatic processor.
Such an automatic developing machine is generally composed of a developing unit and a post-processing unit, and includes an apparatus for conveying a printing plate, each processing tank, and a spray device. The exposed printing plate is pumped up while being conveyed horizontally. Each processing solution is sprayed from a 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 replenished with a replenisher according to the processing amount, operating time, and the like.

  In this case, a large amount of image forming material can be processed without changing the developing solution in the developing tank for a long time by adding an aqueous solution having a higher alkali strength than the developing starting solution to the developing solution as a developing replenisher. In the plate making method of the present invention, it is a preferable aspect to adopt this replenishment method.

  Various surfactants, organic solvents, and the like can be added to the developer as necessary for the purpose of promoting and suppressing developability, dispersing development residue, and improving ink affinity of the printing plate image area.

The surfactant can be selected from nonionic, anionic, cationic or amphoteric surfactants.
Examples of nonionic surfactants include polyethylene glycols such as polyethylene glycol and polyethylene glycol polypropylene glycol block copolymers, polyethylene glycol alkyl ethers such as polyethylene glycol cetyl ether, polyethylene glycol stearyl ether, polyethylene glycol oleyl ether, and polyethylene glycol behenyl ether. Polyethylene glycol polypropylene glycol cetyl ether, polyethylene glycol polypropylene glycol decyl tetradecyl ether and other polyethylene glycol polypropylene glycol alkyl ethers, polyethylene glycol octyl phenyl ether, polyethylene glycol nonyl phenyl ether and other polyesters Polyethylene glycol fatty acid esters such as lenglycol alkylphenyl ethers, ethylene glycol monostearate, ethylene glycol distearate, diethylene glycol stearate, polyethylene glycol distearate, polyethylene glycol monolaurate, polyethylene glycol monostearate, polyethylene glycol monooleate Glyceryl monomyristate, glyceryl monostearate, glyceryl monoisostearate, glyceryl distearate, glyceryl monooleate, glyceryl dioleate and the like, and polyethylene oxide adducts thereof, sorbitan monopalmitate, mono Sorbitan stearate, sorbitan tristearate, mono Sorbitan fatty acid esters such as sorbitan oleate and sorbitan trioleate, and polyethylene oxide adducts thereof, sorbite monosorbate, sorbite tetrastearate, sorbite hexastearate, sorbite tetraoleate, and the like Examples thereof include polyethylene oxide adducts and polyethylene oxide adducts of castor oil.

  Examples of the anionic surfactant include fatty acid salts, abietic acid salts, hydroxyalkane sulfonic acid salts, alkane sulfonic acid salts, dialkyl sulfosuccinic acid ester salts, α-olefin sulfonic acid salts, linear alkyl benzene sulfonic acid salts, branched alkyl benzene sulfonic acid. Acid salts, alkylnaphthalene sulfonates, alkylphenoxy polyoxyethylenepropyl sulfonates, polyoxyethylene alkylsulfophenyl ether salts, N-methyl-N-oleyl taurine sodium salt, N-alkylsulfosuccinic acid monoamide disodium salt, Petroleum sulfonates, sulfated beef tallow oil, fatty acid alkyl ester sulfates, alkyl sulfate esters, polyoxyethylene alkyl ether sulfates, fatty acid compounds Glyceryl sulfate ester salt, polyoxyethylene alkyl phenyl ether sulfate ester salt, polyoxyethylene styryl phenyl ether sulfate ester salt, alkyl phosphate ester salt, polyoxyethylene alkyl ether phosphate ester salt, polyoxyethylene alkyl phenyl ether phosphate ester Preferable examples include salts, partially saponified products of styrene / maleic anhydride copolymer, partially saponified products of olefin / maleic anhydride copolymer, and naphthalene sulfonate formalin condensates.

Examples of the cationic surfactant include alkylamine salts, quaternary ammonium salts such as tetrabutylammonium bromide, polyoxyethylene alkylamine salts, and polyethylene polyamine derivatives.
Examples of amphoteric surfactants include carboxybetaines, alkylaminocarboxylic acids, sulfobetaines, aminosulfuric esters, imidazolines, and the like.
The surfactant concentration in the developer is suitably 0.001 to 10% by mass, more preferably 0.005 to 1% by mass, and most preferably 0.01 to 0.5% by mass.

The following additives can be added to the developer for the purpose of further improving the development performance.
For example, neutral salts such as NaCl, KCl and KBr described in JP-A-58-75152, chelating agents such as EDTA and NTA described in JP-A-58-190952, JP-A-59-121336 [Co (NH ₃ ) ₆ ] Cl ₃ , CoCl ₂ .6H ₂ O and other complexes described in JP-A-50-51324, sodium alkylnaphthalene sulfonate, n-tetradecyl-N, N-dihydroxy Anionic or amphoteric surfactants such as ethylbetaine, nonionic surfactants such as tetramethyldecynediol described in US Pat. No. 4,374,920, p described in JP-A-55-95946 -Cationic polymers such as methyl chloride quaternary compound of dimethylaminomethylpolystyrene, disclosed in JP-A-56-142528 Amphoteric polymer electrolytes such as a copolymer of vinylbenzyltrimethylammonium chloride and sodium acrylate described above, reducing inorganic salts such as sodium sulfite described in JP-A-57-192951, JP-A-58-59444 Inorganic lithium compounds such as lithium chloride described in JP-A No. 59-75255, organometallic surfactants including organic Si and Ti described in JP-A-59-75255, and organoboron compounds described in JP-A-59-84241 And quaternary ammonium salts such as tetraalkylammonium oxide described in EP101010.

In addition, benzyl alcohol or the like is preferable as the organic solvent included in the developer. Further, addition of polyethylene glycol or a derivative thereof, or polypropylene glycol or a derivative thereof is also preferable.
Further, if necessary, hydroquinone, resorcin, sulfurous acid or an inorganic salt-based reducing agent such as sodium or potassium salt of bisulfite, organic carboxylic acid, antifoaming agent, and water softener can be added.

The alkaline developer of the present invention can be used for development processing of various photosensitive lithographic printing plates.
Accordingly, the present invention is directed to a method for making a lithographic printing plate comprising developing a photosensitive lithographic printing plate with the above alkaline developer after exposure.
Examples of the photosensitive lithographic printing plate to which the alkaline developer of the present invention can be applied include various photosensitive lithographic printing plates in which an image recording layer such as a photosensitive layer and a heat-sensitive layer is provided on a support. For example, a conventional positive type, a conventional negative type, a photopolymer type, a thermal positive type, a thermal negative type, and the like are preferably used as such a photosensitive lithographic printing plate. The term "conventional" as used herein refers to a conventional lithographic printing plate precursor that performs imagewise exposure through a transparent positive image or a transparent negative image.

Hereinafter, these various image recording layers will be described.
<Conventional positive type>
A preferable example of a conventional positive photosensitive resin composition is a composition containing an o-quinonediazide compound and an alkali-soluble polymer compound. Examples of o-quinonediazide compounds include esters of 1,2-naphthoquinone-2-diazide-5-sulfonyl chloride and phenol-formaldehyde resin or cresol-formaldehyde resin, and US Pat. No. 3,635,709. There are esters of 1,2-naphthoquinone-2-diazide-5-sulfonyl chloride and pyrogallol acetone resin as described. Examples of the alkali-soluble polymer compound include phenol / formaldehyde resin, cresol / formaldehyde resin, phenol / cresol / formaldehyde co-condensation resin, polyhydroxystyrene, N- (4-hydroxyphenyl) methacrylamide copolymer, Examples thereof include carboxy group-containing polymers described in Japanese Patent No. 36184. Also, acrylic resins containing phenolic hydroxy groups as described in JP-A-51-34711, acrylic resins having sulfonamide groups as described in JP-A-2-866, and urethane Various alkali-soluble polymer compounds such as resins can also be used. Furthermore, the photosensitive resin composition includes compounds such as sensitivity modifiers, printing agents, dyes and the like disclosed in JP-A-7-92660 [0024] to [0027] and those disclosed in the same publication [0031]. It is preferable to add a surfactant for improving the coatability.

<Conventional negative type>
Examples of conventional negative photosensitive resin compositions include those containing a diazo resin and an alkali-soluble or swellable polymer compound (binder).
Examples of the diazo resin include a condensate of an aromatic diazonium salt and an active carbonyl group-containing compound such as formaldehyde. Further, for example, a condensate of p-diazophenylamines and formaldehyde and hexafluorophosphate or An organic solvent-soluble diazo resin inorganic salt that is a reaction product with tetrafluoroborate is exemplified. In particular, a high molecular weight diazo compound containing 20 mol% or more of a hexamer described in JP-A-59-78340 is preferable. Suitable binders include copolymers containing acrylic acid, methacrylic acid, crotonic acid or maleic acid as essential components, for example, 2-hydroxyethyl (meta) as described in JP-A-50-118802. ) Acrylate, (meth) acrylonitrile, multi-component copolymers of monomers such as (meth) acrylic acid, alkyl acrylate, (meth) acrylonitrile, and unsaturated as described in JP-A-56-4144 Mention may be made of multi-component copolymers composed of carboxylic acids. Further, the photosensitive resin composition is a plasticizer for imparting the flexibility and wear resistance of the printing agent, dye, and coating film disclosed in JP-A-7-281425 [0014] to [0015]. It is preferable to add a compound such as a development accelerator and a surfactant for improving coating properties.
As a lower layer of the above-mentioned conventional type positive type or negative type photosensitive layer, a polymer compound having a component having an acid group and a component having an onium group described in JP-A-2000-105462 is used. It is preferable to provide an intermediate layer to be contained.

<Photopolymer type>
(Photosensitive layer)
A photopolymer-type photopolymerizable photosensitive composition (hereinafter referred to as “photopolymerizable composition”) is an addition-polymerizable ethylenically unsaturated bond-containing compound (hereinafter simply referred to as “ethylenically unsaturated bond-containing compound”). And a photopolymerization initiator and a polymer binder as essential components, and if necessary, various compounds such as a colorant, a plasticizer, a thermal polymerization inhibitor and the like.
The ethylenically unsaturated bond-containing compound contained in the photopolymerizable composition is such that, when the photopolymerizable composition is irradiated with actinic rays, it undergoes addition polymerization by the action of the photopolymerization initiator, crosslinks and cures. It is a compound having an ethylenically unsaturated bond. The ethylenically unsaturated bond-containing compound can be arbitrarily selected from compounds having at least one terminal ethylenically unsaturated bond, preferably two or more, such as monomers, prepolymers (ie, dimers). Trimers and oligomers), mixtures thereof, and copolymers thereof. Examples of monomers include esters of unsaturated carboxylic acids (eg, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid) and aliphatic polyhydric alcohol compounds, unsaturated carboxylic acids and aliphatic polyhydric compounds. And amides with a polyvalent amine compound. Urethane addition polymerizable compounds are also suitable.
As the initiator contained in the photopolymerizable composition, various photopolymerization initiators or a combination system (photoinitiation system) of two or more photopolymerization initiators are appropriately selected and used depending on the wavelength of the light source used. For example, an initiation system shown in JP-A-2001-22079 [0021] to [0023] is preferable. The polymer binder contained in the photopolymerizable composition not only functions as a film-forming agent for the photopolymerizable composition, but also needs to dissolve the photosensitive layer in an alkali developer. An organic high molecular weight polymer that is swellable is used. As the polymer, those shown in the publications [0036] to [0063] are useful. In addition, it is also preferable to add an additive (for example, a surfactant for improving the coating property) shown in the publications [0079] to [0088] to the photopolymerizable composition.
Further, it is preferable to provide an oxygen-blocking protective layer on the photosensitive layer in order to prevent the oxygen polymerization inhibiting action. Examples of the polymer contained in the oxygen barrier protective layer include polyvinyl alcohol and a copolymer thereof. Further, it is preferable to provide an intermediate layer or an adhesive layer as disclosed in JP-A-2001-228608 [0124] to [0165] as a lower layer of the photopolymer type photosensitive layer.

<Thermal positive type>
(Thermosensitive layer)
The thermal positive type heat-sensitive layer contains an alkali-soluble polymer compound and a photothermal conversion substance. This alkali-soluble polymer compound includes a homopolymer containing an acidic group in the polymer, a copolymer thereof, and a mixture thereof. In particular, an acidic group such as the following (1) or (2) is included. It is preferable from the viewpoint of solubility in an alkali developer: (1) phenolic hydroxy group (—Ar—OH), (2) sulfonamide group (—SO ₂ NH—R). In particular, it is preferable to have a phenolic hydroxy group from the viewpoint of excellent image formability upon exposure with an infrared laser or the like, for example, phenol formaldehyde resin, m-cresol formaldehyde resin, p-cresol formaldehyde resin, m− / p−. Preferable examples include mixed cresol formaldehyde resin, phenol / cresol (any of m-, p- and m- / p-mixed) mixed formaldehyde resin and the like, and pyrogallol acetone resin. More specifically, the polymers shown in [0023] to [0042] of JP-A No. 2001-305722 are preferably used.
The photothermal conversion substance converts exposure energy into heat and can efficiently cancel the interaction of the exposed area of the heat sensitive layer. From the viewpoint of recording sensitivity, a pigment or dye having a light absorption region in the infrared region with a wavelength of 700 to 1200 nm is preferable. As a dye. Specifically, azo dyes, metal complex azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, quinoneimine dyes, methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, metal thiolate complexes (for example, A dye such as a nickel thiolate complex) can be used. Among these, cyanine dyes are preferable, and examples include cyanine dyes represented by general formula (I) in JP-A No. 2001-305722. In the composition of the thermal positive type, it is preferable to add a sensitivity control agent, a printing agent, a compound such as a dye similar to those described for the conventional positive type, and a surfactant for improving the coating property. Specifically, compounds shown in [0053] to [0059] of JP-A No. 2001-305722 are preferable.
The thermal positive type heat-sensitive layer may be a single layer or may be provided as a two-layer structure as described in JP-A-11-218914.
An undercoat layer is preferably provided between the thermal positive type heat-sensitive layer and the support. Examples of components contained in the undercoat layer include various organic compounds disclosed in JP-A-2001-305722, [0068].

<Thermal negative type>
(Thermosensitive layer)
The thermal negative-type heat-sensitive layer is a negative-type heat-sensitive layer in which the infrared laser irradiation part is cured to form an image part.
As one of such thermal negative type heat-sensitive layers, a polymerization type layer is preferably exemplified. The polymerization layer comprises (A) an infrared absorber, (B) a radical generator (radical polymerization initiator), a curing reaction caused by the generated radical (C) a radical polymerizable compound, and (D) a binder. Containing polymer.
In the polymerization layer, the infrared rays absorbed by the infrared absorber are converted into heat, and the generated heat decomposes radical polymerization initiators such as onium salts to generate radicals. The radically polymerizable compound is selected from compounds having a terminal ethylenically unsaturated bond, and a polymerization reaction is caused in a chain by the generated radicals and is cured. Examples of the infrared absorber (A) include the above-described photothermal conversion substance contained in the above-described thermal positive type heat-sensitive layer. In particular, as a specific example of the cyanine dye, paragraph number of JP-A No. 2001-133969 [0017] to [0019] may be mentioned. (B) Examples of the radical generator include onium salts. Specific examples of onium salts that can be suitably used are described in paragraphs [0030] to [0033] of JP-A No. 2001-133969. Things can be mentioned. (C) The radically polymerizable compound is selected from compounds having at least one terminal ethylenically unsaturated bond, preferably two or more. (D) It is preferable to use a linear organic polymer as the binder polymer, and a linear organic polymer that is soluble or swellable in water or weak alkaline water is selected. Of these, a (meth) acrylic resin having a benzyl group or an allyl group and a carboxy group in the side chain is particularly preferable because of its excellent balance of film strength, sensitivity, and developability. With respect to (C) the radical polymerizable compound and (D) the binder polymer, those described in detail in the publications [0036] to [0060] can be used. As other additives, it is also preferable to add an additive (for example, a surfactant for improving coatability) shown in the publications [0061] to [0068].

  In addition to the polymerization type, an acid-crosslinking type layer is preferably used as one of the thermal negative type heat-sensitive layers. The acid cross-linking layer comprises (E) a compound that generates an acid by light or heat (hereinafter referred to as “acid generator”) and (F) a compound that cross-links by the generated acid (hereinafter referred to as “cross-linking agent”). And (G) an alkali-soluble polymer compound that can react with a crosslinking agent in the presence of an acid. In order to efficiently use the energy of the infrared laser, (A) an infrared absorber is blended in the acid crosslinking layer. Examples of the acid generator (E) include compounds capable of generating an acid upon thermal decomposition, such as a photoinitiator for photopolymerization, a photochromic agent for dyes, and an acid generator used for a microresist. . (F) The crosslinking agent includes (i) an aromatic compound substituted with a hydroxymethyl group or an alkoxymethyl group, (ii) a compound having an N-hydroxymethyl group, an N-alkoxymethyl group or an N-acyloxymethyl group, Or (iii) an epoxy compound is mentioned. (G) Examples of the alkali-soluble polymer compound include novolak resins and polymers having a hydroxyaryl group in the side chain.

<Back coat layer>
In order to prevent the image recording layer from being scratched when it is overlaid on the back surface of the photosensitive lithographic printing plate obtained by providing various image recording layers, a coating layer made of an organic polymer compound. (Referred to as “back coat layer”).
<Exposure>
The photosensitive lithographic printing plate is subjected to image exposure by various processing methods corresponding to the image recording layer. Examples of the actinic ray light source used for image exposure include a mercury lamp, a metal halide lamp, a xenon lamp, and a chemical lamp. Examples of the laser beam include a helium-neon laser (He-Ne laser), an argon laser, a krypton laser, a helium-cadmium laser, a KrF excimer laser, a semiconductor laser, a YAG laser, and a YAG-SHG laser.

The alkaline developer of the present invention is particularly preferably used for plate making from an infrared-sensitive lithographic printing plate. Therefore, here, the photosensitive layer (hereinafter also referred to as a heat-sensitive layer) having a photosensitive layer on the support is exposed to an infrared-sensitive lithographic printing plate containing an infrared-absorbing dye and an alkali-soluble resin. The method for making a lithographic printing plate including the development with an alkaline developer described in detail in 1) is touched.
The infrared photosensitive lithographic printing plate will be described in detail below. First, the components of the heat-sensitive layer serving as the image recording layer will be described.

[Infrared absorbing dye]
The infrared absorbing dye used in the heat sensitive layer is not particularly limited as long as it absorbs infrared rays and generates heat, and various dyes known as infrared absorbing dyes can be used.
As the infrared absorbing dye, 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) can be used. Specific examples include azo dyes, metal complex azo dyes, pyrazolone azo dyes, quinoneimine dyes, methine dyes, and cyanine dyes. In the present invention, among these dyes, those that absorb infrared light or near infrared light are particularly preferred because they are suitable for use in lasers that emit infrared light or near infrared light.
Examples of dyes that absorb such 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-60-59240, 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, a near-infrared absorption sensitizer described in US Pat. No. 5,156,938 is also preferably used as the dye, and a substituted arylbenzo (thio) pyrylium salt described in US Pat. No. 3,881,924, Trimethine thiapyrylium salts described in JP-A-57-142645 (US Pat. No. 4,327,169), JP-A-58-181051, 58-220143, 59-41363, 59-84248 Nos. 59-84249, 59-146063, 59-146061, pyranlium compounds, cyanine dyes described in JP-A-59-216146, US Pat. No. 4,283,475 Pentamethine thiopyrylium salts described in No. 5 and pyrylium compounds disclosed in Japanese Patent Publication Nos. 5-13514 and 5-19702 But as the commercially available products, Epolight III-178 of Eporin Co., Epolight III-130, Epolight III-125 and the like are particularly preferably used.
Infrared absorbing dyes described as formulas (I) and (II) in US Pat. No. 4,756,993 are particularly preferred as infrared absorbing dyes used in the heat-sensitive layer. The dye exhibits a very strong interaction with the alkalized soluble resin, and is excellent in the unexposed area alkaline development resistance of the heat-sensitive layer.

The amount of the infrared absorbing dye added to the heat-sensitive layer is suitably 3 to 50%, preferably 5 to 40%, more preferably 8 to 35%, from the viewpoint of sensitivity and layer durability with respect to the heat-sensitive layer mass. .
Specific examples of the infrared absorbing dye are shown below, but the present invention is not limited thereto.

[Alkali-soluble resin]
The alkali-soluble resin used in the heat-sensitive layer is a water-insoluble and alkali-water-soluble resin (hereinafter, appropriately referred to as alkali-soluble polymer), which contains acidic groups in the main chain and / or side chain in the polymer. Homopolymers, copolymers thereof or mixtures thereof. Therefore, the heat-sensitive layer of the photosensitive lithographic printing plate has a property of dissolving when contacted with an alkaline developer.
The alkali-soluble polymer used in the heat-sensitive layer is not particularly limited as long as it is a conventionally known polymer, but any one of (1) a phenolic hydroxyl group, (2) a sulfonamide group, and (3) an active imide group A polymer compound having a group in the molecule is preferred. For example, the following are exemplified, but not limited thereto.

  (1) Examples of the polymer compound having a phenolic hydroxyl group include phenol formaldehyde resin, m-cresol formaldehyde resin, p-cresol formaldehyde resin, m- / p-mixed cresol formaldehyde resin, phenol / cresol (m-, p Any of-and / or m- / p-mixing) may be mentioned, including novolak resins such as mixed formaldehyde resins and pyrogallol acetone resins. In addition to this, a polymer compound having a phenolic hydroxyl group in the side chain is preferably used as the polymer compound having a phenolic hydroxyl group. As a polymer compound having a phenolic hydroxyl group in the side chain, a polymerizable monomer comprising a low molecular compound having at least one unsaturated bond polymerizable with the phenolic hydroxyl group is homopolymerized, or other polymerizable property is added to the monomer. Examples thereof include a polymer compound obtained by copolymerizing monomers.

  Examples of the polymerizable monomer having a phenolic hydroxyl group include acrylamide, methacrylamide, acrylic acid ester, methacrylic acid ester, and hydroxystyrene having a phenolic hydroxyl group. Specifically, N- (2-hydroxyphenyl) acrylamide, N- (3-hydroxyphenyl) acrylamide, N- (4-hydroxyphenyl) acrylamide, N- (2-hydroxyphenyl) methacrylamide, N -(3-Hydroxyphenyl) methacrylamide, N- (4-Hydroxyphenyl) methacrylamide, o-Hydroxyphenyl acrylate, m-Hydroxyphenyl acrylate, p-Hydroxyphenyl acrylate, o-Hydroxyphenyl methacrylate , M-hydroxyphenyl methacrylate, p-hydroxyphenyl methacrylate, o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, 2- (2-hydroxyphenyl) ethyl acrylate, 2- (3-hydroxyphenyl) ethyl Acrylate, 2- 4-hydroxyphenyl) ethyl acrylate, 2- (2-hydroxyphenyl) ethyl methacrylate, 2- (3-hydroxyphenyl) ethyl methacrylate can be suitably used 2- (4-hydroxyphenyl) ethyl methacrylate. Such resins having a phenolic hydroxyl group may be used in combination of two or more. Furthermore, as described in US Pat. No. 4,123,279, phenol and formaldehyde having an alkyl group having 3 to 8 carbon atoms as a substituent, such as t-butylphenol formaldehyde resin and octylphenol formaldehyde resin, These copolymers may be used in combination.

(2) Examples of the alkali-soluble polymer compound having a sulfonamide group include a polymer compound obtained by homopolymerizing a polymerizable monomer having a sulfonamide group or copolymerizing the monomer with another polymerizable monomer. . The polymerizable monomer having a sulfonamide group includes one or more sulfonamide groups —NH—SO ₂ — in which at least one hydrogen atom is bonded to a nitrogen atom and one or more polymerizable unsaturated bonds in one molecule. And a polymerizable monomer comprising a low molecular weight compound. 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 is preferable.

(3) The alkali-soluble polymer compound having an active imide group is preferably one having an active imide group in the molecule. Examples thereof include a polymer compound obtained by homopolymerizing a polymerizable monomer composed of one or more low-molecular compounds or by copolymerizing the polymerizable monomer with another polymerizable monomer.
As such a compound, specifically, N- (p-toluenesulfonyl) methacrylamide, N- (p-toluenesulfonyl) acrylamide and the like can be preferably used.

  Furthermore, as the alkali-soluble polymer compound, a polymer compound obtained by polymerizing two or more of the polymerizable monomer having a phenolic hydroxyl group, the polymerizable monomer having a sulfonamide group, and the polymerizable monomer having an active imide group is used. Alternatively, it is preferable to use a polymer compound obtained by copolymerizing these two or more polymerizable monomers with another polymerizable monomer. When a polymerizable monomer having a phenolic hydroxyl machine is copolymerized with a polymerizable monomer having a sulfonamide group and / or a polymerizable monomer having an active imide group, the compounding polymerization ratio (mass ratio) of these components is It is preferably in the range of 50:50 to 5:95, particularly preferably in the range of 40:60 to 10:90.

  When the alkali-soluble polymer is a copolymer of a polymerizable monomer having a phenolic hydroxyl group, a polymerizable monomer having a sulfonamide group, or a polymerizable monomer having an active imide group and another polymerizable monomer The monomer that imparts alkali solubility is preferably contained in an amount of 10 mol% or more, more preferably 20 mol% or more. When the copolymerization component is less than 10 mol%, alkali solubility tends to be insufficient, and the development latitude improvement effect may not be sufficiently achieved.

Examples of the monomer component to be copolymerized with the polymerizable monomer having a phenolic hydroxyl group, the polymerizable monomer having a sulfonamide group, or the polymerizable monomer having an active imide group include the compounds listed in the following (m1) to (m12). However, the present invention is not limited to these.
(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, and 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-acryloylacrylamide, N-acetylmethacrylamide, N-propionylmethacrylamide, N- (p-chlorobenzoyl) methacrylamide.
(M12) Unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic anhydride and itaconic acid.

The alkali-soluble polymer compound preferably has a phenolic hydroxyl group in terms of excellent image-forming properties in exposure with an infrared laser or the like, such as phenol formaldehyde resin, m-cresol formaldehyde resin, p-cresol formaldehyde resin, Preferred examples include novolak resins and pyrogallol acetone resins such as m- / p-mixed cresol formaldehyde resin and phenol / cresol (which may be m-, p-, or m- / p-mixed) mixed formaldehyde resin.
Moreover, as an alkali-soluble polymer compound having a phenolic hydroxyl group, as disclosed in US Pat. No. 4,123,279, such as t-butylphenol formaldehyde resin and octylphenol formaldehyde resin, Examples thereof include a condensation polymer of phenol and formaldehyde having a C 3-8 alkyl group as a substituent.
As a copolymerization method of the alkali-soluble polymer compound, a conventionally known graft copolymerization, block copolymerization, random copolymerization method or the like can be used.

In the present invention, when the alkali-soluble polymer is a homopolymer or copolymer of a polymerizable monomer having a phenolic hydroxyl group, a polymerizable monomer having a sulfonamide group, or a polymerizable monomer having an active imide group, the weight average Those having a molecular weight of 2,000 or more and a number average molecular weight of 500 or more are preferred. More preferably, the weight average molecular weight is 5,000 to 300,000, the number average molecular weight 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, when the alkali-soluble polymer is a resin such as phenol formaldehyde resin or cresol aldehyde resin, the weight average molecular weight is 500 to 20.000, and the number average molecular weight is 200 to 10,000. preferable.
These alkali-soluble polymer compounds may be used alone or in combination of two or more. From the viewpoint of both the sensitivity and durability of the heat-sensitive layer, the heat-sensitive layer has a total solid content of 30 to 99% by mass, preferably It is used in an amount of 40 to 95% by mass, particularly preferably 50 to 90% by mass.

（式中、Ｘｍは単結合又は２価の連結基を、Ｙは水素又はカルボキシル基を、Ｚは水素、アルキル基又はカルボキシル基を表す。）
一般式（ｉ）で表される重合性モノマー単位を構成するモノマーとして、カルボキシル基と、重合可能な不飽和基を分子内にそれぞれ１以上有する重合性モノマーがある。
そのような重合性モノマーの具体例として、アクリル酸、メタクリル酸、マレイン酸、無水マレイン酸、イタコン酸、無水イタコン酸等のα、β−不飽和カルボン酸類を挙げることができる。 The heat-sensitive layer may also contain an alkali-soluble polymer compound having a carboxyl group (hereinafter sometimes referred to as “component (B1)”).
The polymer compound (B1) may be any alkali-soluble polymer compound having a carboxyl group, but polymer compounds (b1-1) and (b1-2) defined below are preferred.
(B1-1) An alkali-soluble polymer compound having a polymerizable monomer unit represented by the following general formula (i) (hereinafter also referred to as polymer compound (b1-1))

(In the formula, Xm represents a single bond or a divalent linking group, Y represents hydrogen or a carboxyl group, and Z represents hydrogen, an alkyl group or a carboxyl group.)
As a monomer constituting the polymerizable monomer unit represented by the general formula (i), there is a polymerizable monomer having at least one carboxyl group and one polymerizable unsaturated group in the molecule.
Specific examples of such polymerizable monomers include α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid and itaconic anhydride.

Examples of the monomer to be copolymerized with the polymerizable monomer having a carboxyl group include the following (1) to (11), but are not limited thereto.
(1) Acrylic acid esters and methacrylic acid esters having an aliphatic hydroxyl group such as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate.
(2) Methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, octyl acrylate, benzyl acrylate, 2-chloroethyl acrylate, glycidyl acrylate, N-dimethylaminoethyl Alkyl acrylates such as acrylates;
(3) Methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, 2-chloroethyl methacrylate, glycidyl methacrylate, N-dimethylaminoethyl Alkyl methacrylate such as methacrylate.

(4) Acrylamide, methacrylamide, N-methylolacrylamide, N-ethylacrylamide, N-hexylmethacrylamide, N-cyclohexylacrylamide, N-hydroxyethylacrylamide, N-phenylacrylamide, N-nitrophenylacrylamide, N-ethyl- Acrylamide or methacrylamide such as N-phenylacrylamide.
(5) 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.
(6) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl butyrate and vinyl benzoate.
(7) Styrenes such as styrene, α-methylstyrene, methylstyrene, chloromethylstyrene.

(8) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, and phenyl vinyl ketone.
(9) Olefins such as ethylene, propylene, isobutylene, butadiene and isoprene.
(10) N-vinylpyrrolidone, N-vinylcarbazole, 4-vinylpyridine, acrylonitrile, methacrylonitrile and the like.
(11) Unsaturated imides such as maleimide, N-acryloylacrylamide, N-acetylmethacrylamide, N-propionylmethacrylamide, N- (p-chlorobenzoyl) methacrylamide.

式中、ＸはＯ、Ｓ、又はＮ−Ｒ¹²を表す。Ｒ¹⁰〜Ｒ¹²は、各々独立に、水素原子又はアルキル基を表す。ｍ、ｎ、ｏは、各々独立に、２から５の整数を表し、Ｃ_mＨ_2m、Ｃ_nＨ_2n、Ｃ_oＨ_2oは、各々、直鎖でも分岐構造でもよい。ｐ、ｑ、ｒは各々独立に、０から３，０００の整数を表し、ｐ＋ｑ＋ｒ≧２である。 Moreover, the monomer of the following general formula (ii) is also preferably used.

In the formula, X represents O, S, or N—R ¹² . R ^{10 to} R ¹² each independently represents a hydrogen atom or an alkyl group. m, n and o each independently represents an integer of 2 to 5, and C _m H _2m , C _n H _2n and C _o H _2o may each be linear or branched. p, q, and r each independently represent an integer of 0 to 3,000, and p + q + r ≧ 2.

The alkyl group in R ¹⁰ to R ^12, preferably one having 1 to 12 carbon atoms, specifically, methyl group, ethyl group, n- propyl group, an isopropyl group. p, q, and r preferably represent an integer of 0 to 500, and more preferably represent an integer of 0 to 100.
Examples of the monomer corresponding to the repeating unit represented by the general formula (ii) are listed below, but the present invention is not limited thereto.

The repeating unit represented by the general formula (ii) is a commercially available hydroxypoly (oxyalkylene) material, for example, trade name Pluronic (Pluronic (Asahi Denka Kogyo Co., Ltd.)), Adeka Polyether (Asahi Denka Kogyo Co., Ltd.) ), Carbowax (Carbowax (Glico Product)), Triton (Toriton (Rohm and Haas), and PEG (Daiichi Kogyo Seiyaku Co., Ltd.)) It can manufacture by making it react with acrylic acid, methacrylic acid, an acryl chloride, methacryl chloride, or acrylic acid anhydride by the method of this.
Separately, poly (oxyalkylene) diacrylate produced by a known method can also be used.

  Commercially available monomers include hydroxyl group-terminated polyalkylene glycol mono (meth) acrylate manufactured by Nippon Oil & Fats Co., Ltd. Blemmer PE-90, Blemmer PE-200, Blemmer PE-350, Blemmer AE-90, Blemmer AE-200, Blemmer AE-400, Blemmer PP-1000, Blemmer PP-500, Blemmer PP-800, Blemmer AP-150, Blemmer AP-400, Blemmer AP-550, Blemmer AP-800, Blemmer 50PEP-300, Blemmer 70PEP-350B, Blemmer AEP series, Blemmer 55PET-400, Blemmer 30PET-800, Blemmer 55PET-800, Blemmer AET series, Blemmer 30PPT-800, Blemmer 50PPT-800, Blemmer 70PPT-800, Blemmer APT series, Blemmer 10PPB-500B, Blemmer 10APB-500B Etc. Similarly, Blemmer PME-100, Blemmer PME-200, Blemmer PME-400, Blemmer PME-1000, Blemmer PME-4000, Blemmer AME-400, Blemmer as alkyl-terminated polyalkylene glycol mono (meth) acrylates manufactured by NOF Corporation 50POEP-800B, Blemmer 50AOEP-800B, Blemmer PLE-200, Blemmer ALE-200, Blemmer ALE-800, Blemmer PSE-400, Blemmer PSE-1300, Blemmer ASEP series, Blemmer PKEP series, Blemmer AKEP series, Blemmer ANE-300 , BLEMMER ANE-1300, BLEMMER PNEP series, BLEMMER PNPE series, BLEMMER 43ANEP-500, BLEMMER 70ANEP-550, etc., and Kyoeisha Chemical Co., Ltd. Light ester MC, Light ester 130MA, Light ester 041MA, Light acrylate BO-A Acrylate EC-A, Light acrylate MTG-A, Light acrylic Over DOO 130A, Light Acrylate DPM-A, Light Acrylate P-200A, Light Acrylate NP-4EA, like Light Acrylate NP-8EA.

The minimum constitutional unit having a polymerizable monomer component having at least one carboxyl group and at least one polymerizable unsaturated group in the polymer compound (b1-1) is not necessarily limited to one kind, and is the same. It is also possible to use a copolymer obtained by copolymerizing two or more kinds of minimum structural units having the above acidic group or two or more kinds of minimum structural units having different acidic groups.
As the copolymerization method, conventionally known graft copolymerization, block copolymerization, random copolymerization, and the like can be used.

Ｒ¹³は水素原子、置換基（例えばアルキル、アリール、アルコキシ、エステル、ウレタン、アミド、ウレイド、ハロゲノの各基が好ましい。）を有していてもよいアルキル、アルケニル、アラルキル、アリール、アルコキシ、アリーロキシ基を示し、好ましくは水素原子、炭素原子数１〜８個のアルキル基もしくは炭素原子数２〜８のアルケニル基、炭素原子数６〜１５個のアリール基を示す。
Ｒ¹⁴、Ｒ¹⁵、Ｒ¹⁶はそれぞれ同一でも相異していてもよい、単結合、置換基（例えばアルキル、アルケニル、アラルキル、アリール、アルコキシ及びハロゲノの各基が好ましい。）を有していてもよい二価の脂肪族又は芳香族炭化水素を示す。好ましくは炭素原子数１〜２０のアルキレン基、炭素原子数６〜１５のアリーレン基、更に好ましくは炭素原子数１〜８個のアルキレン基を示す。
また、必要に応じ、Ｒ¹⁴、Ｒ¹⁵、Ｒ¹⁶中にイソシアネート基と反応しない他の官能基、例えばエステル基、ウレタン基、アミド基、ウレイド基、炭素−炭素不飽和結合を有していてもよい。なお、Ｒ¹³、Ｒ¹⁴、Ｒ¹⁵、Ｒ¹⁶のうちの２又は３個で環を構成してもよい。
Ａｒは置換基を有していてもよい三価の芳香族炭化水素を示し、好ましくは炭素原子数６〜１５個の芳香族基を示す。 (B1-2) A reaction product of a diol compound represented by the following general formula (iii), (iv) or (v) having a carboxyl group and a diisocyanate compound represented by the following general formula (viii) as a basic skeleton And an alkali-soluble polymer compound having a carboxyl group (hereinafter, also referred to as polymer compound (b1-2)).

R ¹³ represents a hydrogen atom, a substituent (for example, alkyl, aryl, alkoxy, ester, urethane, amide, ureido, halogeno are preferable), alkyl, alkenyl, aralkyl, aryl, alkoxy, aryloxy Preferably a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, or an aryl group having 6 to 15 carbon atoms.
R ¹⁴ , R ¹⁵ and R ¹⁶ may have the same or different single bond and substituent (for example, alkyl, alkenyl, aralkyl, aryl, alkoxy and halogeno groups are preferred). Or a divalent aliphatic or aromatic hydrocarbon. Preferably an alkylene group having 1 to 20 carbon atoms, an arylene group having 6 to 15 carbon atoms, more preferably an alkylene group having 1 to 8 carbon atoms is shown.
If necessary, R ¹⁴ , R ¹⁵ and R ¹⁶ have other functional groups that do not react with isocyanate groups, such as ester groups, urethane groups, amide groups, ureido groups, and carbon-carbon unsaturated bonds. Also good. In addition, you may comprise a ring by 2 or 3 of R < ¹³ >, R <^14> , R <^15> , R < ¹⁶ >.
Ar represents a trivalent aromatic hydrocarbon which may have a substituent, and preferably an aromatic group having 6 to 15 carbon atoms.

OCN-R ¹⁸ -NCO (viii)
In the formula, R ¹⁸ represents a divalent aliphatic or aromatic hydrocarbon which may have a substituent (for example, alkyl, alkenyl, aralkyl, aryl, alkoxy and halogeno groups are preferable). If necessary, R ¹⁸ may have another functional group that does not react with an isocyanate group, such as an ester, urethane, amide, ureido group, or carbon-carbon unsaturated bond.

Specific examples of the diol compound having a carboxyl group represented by the general formula (iii), (iv) or (v) include those shown below.
3,5-dihydroxybenzoic acid, 2,2-bis (hydroxymethyl) propionic acid, 2,2-bis (2-hydroxyethyl) propionic acid, 2,2-bis (3-hydroxypropyl) propionic acid, Bis (hydroxymethyl) acetic acid, bis (4-hydroxyphenyl) acetic acid, 4,4-bis (4-hydroxyphenyl) pentanoic acid, tartaric acid, N, N-bis (2-hydroxyethyl) -3-carboxy-propionamide Etc.

式中、Ｒ¹⁷はそれぞれ水素原子又は炭素原子数１〜８のアルキル基を示し、ｎは２以上の整数を示す。Ｒ¹⁷における炭素原子数１〜８のアルキル基としては、例えばメチル基、エチル基、i-プロピル基、n-ブチル基、i-ブチル基などが挙げられる。
以下に、上記一般式（vi）又は（vii）で表されるジオールの具体例を示すが、本発明はこれらに限定されるものではない。 The alkali-soluble polymer compound having a carboxyl group (b1-2) is preferably a reaction product in which a diol represented by the following general formula (vi) or (vii) is combined.

In the formula, R ¹⁷ represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and n represents an integer of 2 or more. Examples of the alkyl group having 1 to 8 carbon atoms in R ¹⁷ include a methyl group, an ethyl group, an i-propyl group, an n-butyl group, and an i-butyl group.
Specific examples of the diol represented by the general formula (vi) or (vii) are shown below, but the present invention is not limited thereto.

Specific example of (vi)
HO-(-CH ₂ CH ₂ O-) ₃ -H
HO-(-CH ₂ CH ₂ O-) ₄ -H
HO-(-CH ₂ CH ₂ O-) ₅ -H
HO-(-CH ₂ CH ₂ O-) ₆ -H
HO-(-CH ₂ CH ₂ O-) ₇ -H
HO-(-CH ₂ CH ₂ O-) ₈ -H
HO-(-CH ₂ CH ₂ O-) ₁₀ -H
HO-(-CH ₂ CH ₂ O-) ₁₂ -H
Polyethylene glycol (average molecular weight 1000)
Polyethylene glycol (average molecular weight 2000)
Polyethylene glycol (average molecular weight 4000)
HO-(-CH ₂ CH (CH ₃ ) O-) ₃ -H
HO-(-CH ₂ CH (CH ₃ ) O-) ₄ -H
HO-(-CH ₂ CH (CH ₃ ) O-) ₆ -H
Polypropylene glycol (average molecular weight 1000)
Polypropylene glycol (average molecular weight 2000)
Polypropylene glycol (average molecular weight 4000)

Specific example of (vii)
HO-(-CH ₂ CH ₂ CH ₂ O-) ₃ -H
HO-(-CH ₂ CH ₂ CH ₂ O-) ₄ -H
HO-(-CH ₂ CH ₂ CH ₂ O-) ₈ -H
HO-(-CH ₂ CH ₂ CH (CH ₃ ) O-) ₁₂ -H

Specific examples of the diisocyanate compound represented by the general formula (viii) include the following compounds.
That is, 2,4-tolylene diisocyanate, dimer of 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, p-xylylene diisocyanate, m-xylylene diisocyanate, 4,4′-diphenylmethane diisocyanate, Aromatic diisocyanate compounds such as 1,5-naphthalene diisocyanate and 3,3′-dimethylbiphenyl-4,4′-diisocyanate; aliphatic diisocyanates such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate and dimer diisocyanate Compound, isophorone diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate), methylcyclohexane-2,4 (or 2,6) -diisocyanate, 1 An aliphatic diisocyanate compound such as 1,3- (isocyanatomethyl) cyclohexane; a diisocyanate compound which is a reaction product of a diol and diisocyanate such as an adduct of 1 mol of 1,3-butylene glycol and 2 mol of tolylene diisocyanate, and the like. Can be mentioned.

  The molar ratio of the diisocyanate and the diol compound used for the synthesis of the polymer compound (b1-2) is preferably 0.8: 1 to 1.2-1, and when an isocyanate group remains at the polymer terminal, alcohols or By treating with amines or the like, it is finally synthesized in a form in which no isocyanate group remains.

As the component (B1), one type may be used alone from the above polymer compounds (b1-1) and (b1-2), or two or more types may be used in combination.
The content of the repeating unit having a carboxyl group contained in the component (B1) is 2 mol% or more based on the total amount of each monomer of the component (B1), preferably 2 to 70 mol%. Yes, more preferably in the range of 5 to 60 mol%.
The preferred weight average molecular weight of the component (B1) is preferably 3000 to 300,000, more preferably 6,000 to 100,000.

  Furthermore, the preferable addition amount of (B1) component is the range of 0.005-80 mass% with respect to the total solid content mass of a heat sensitive layer, Preferably it is the range of 0.01-50 mass%, More preferably Is in the range of 1-20% by weight.

〔Additive〕
In forming the heat-sensitive layer, in addition to the above components, various additives can be added as necessary as long as the effects of the present invention are not impaired.
-Solubility-inhibiting compounds-
The photosensitive lithographic printing plate can contain various inhibitors in the heat-sensitive layer for the purpose of increasing its inhibition (solubility inhibition).
Although it does not specifically limit as this inhibitor, A quaternary ammonium salt, a polyethyleneglycol type compound, etc. are mentioned.

Although it does not specifically limit as a quaternary ammonium salt, A tetraalkyl ammonium salt, a trialkyl aryl ammonium salt, a dialkyl diaryl ammonium salt, an alkyl triaryl ammonium salt, a tetraaryl ammonium salt, a cyclic ammonium salt, and a bicyclic ammonium salt are mentioned. .
Specifically, tetrabutylammonium bromide, tetrapentylammonium bromide, tetrahexylammonium bromide, tetraoctylammonium bromide, tetralaurylammonium bromide, tetraphenylammonium bromide, tetranaphthylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium iodide , Tetrastearyl ammonium bromide, lauryl trimethyl ammonium bromide, stearyl trimethyl ammonium bromide, behenyl trimethyl ammonium bromide, lauryl triethyl ammonium bromide, phenyl trimethyl ammonium bromide, 3-trifluoromethylphenyl trimethyl ammonium bromide, benzyl trimethyl ammonium bromide De, dibenzyl dimethyl ammonium bromide, distearyl dimethyl ammonium bromide, tristearyl methyl ammonium bromide, benzyl triethyl ammonium bromide, hydroxyphenyl trimethyl ammonium bromide, N- methyl pyridinium bromide, and the like. In particular, quaternary ammonium salts described in JP-A-2003-107688 and JP-A-2003-167332 are preferred.

  The addition amount of the quaternary ammonium salt is 0.1 to 50% by mass in terms of solid content with respect to the total solid content of the image recording layer in that it does not adversely affect the sufficient solubility inhibiting effect and film forming property of the binder. It is preferable that there is more preferably 1 to 30% by mass.

  Although it does not specifically limit as a polyethyleneglycol type compound, The thing of the following structure is mentioned.

^{R 1 - {- O- (R} 3 -O-) m-R 2} n
(R ¹ is a polyhydric alcohol residue or polyhydric phenol residue, R ² is a hydrogen atom, an alkyl group, alkenyl group, alkynyl group, alkyloyl group, aryl which may have a substituent of 1 to 25 carbon atoms, aryl Group or aryloyl group, R ³ represents an alkylene residue which may have a substituent, m is an average of 10 or more, and n is an integer of 1 to 4.

  Examples of polyethylene glycol compounds having the above structure include polyethylene glycols, polypropylene glycols, polyethylene glycol alkyl ethers, polypropylene glycol alkyl ethers, polyethylene glycol aryl ethers, polypropylene glycol aryl ethers, polyethylene glycol alkyl aryl ethers. , Polypropylene glycol alkyl aryl ethers, polyethylene glycol glycerin esters, polypropylene glycol glycerin esters, polyethylene sorbitol esters, polypropylene glycol sorbitol esters, polyethylene glycol fatty acid esters, polypropylene glycol fatty acid esters, polyethylene glycolated ethylene Diamines, polypropylene glycolated ethylenediamines, polyethylene glycolated diethylenetriamine, and polypropylene glycol diethylenetriamines.

  Specific examples thereof include polyethylene glycol 1000, polyethylene glycol 2000, polyethylene glycol 4000, polyethylene glycol 10000, polyethylene glycol 20000, polyethylene glycol 50000, polyethylene glycol 100000, polyethylene glycol 200000, polyethylene glycol 500000, polypropylene glycol 1500, polypropylene glycol. 3000, polypropylene glycol 4000, polyethylene glycol methyl ether, polyethylene glycol ethyl ether, polyethylene glycol phenyl ether, polyethylene glycol dimethyl ether, polyethylene glycol diethyl ether, polyethylene glycol diphenyl ether , Polyethylene glycol lauryl ether, polyethylene glycol dilauryl ether, polyethylene glycol nonyl ether, polyethylene glycol cetyl ether, polyethylene glycol stearyl ether, polyethylene glycol distearyl ether, polyethylene glycol behenyl ether, polyethylene glycol dibehenyl ether, polypropylene glycol methyl ether, polypropylene Glycol ethyl ether, polypropylene glycol phenyl ether, polypropylene glycol dimethyl ether, polypropylene glycol diethyl ether, polypropylene glycol diphenyl ether, polypropylene glycol lauryl ether, polypropylene glycol dilauryl ether, Ripropylene glycol nonyl ether, polyethylene glycol acetyl ester, polyethylene glycol diacetyl ester, polyethylene glycol benzoic acid ester, polyethylene glycol lauryl ester, polyethylene glycol dilauryl ester, polyethylene glycol nonyl acid ester, polyethylene glycol cetyl acid ester, polyethylene glycol stearoyl ester, Polyethylene glycol distearoyl ester, polyethylene glycol behenate ester, polyethylene glycol dibehenate ester, polypropylene glycol acetyl ester, polypropylene glycol diacetyl ester, polypropylene glycol benzoate ester, polypropylene glycol dibenzoate ester, Polypropylene glycol laurate, polypropylene glycol dilaurate, polypropylene glycol nonyl ester, polyethylene glycol glycerol ether, polypropylene glycol glycerol ether, polyethylene glycol sorbitol ether, polypropylene glycol sorbitol ether, polyethylene glycolated ethylenediamine, polypropylene glycolated ethylenediamine, polyethylene Examples include glycolated diethylenetriamine, polypropylene glycolated diethylenetriamine, and polyethylene glycolated pentamethylenehexamine.

  The addition amount of the polyethylene glycol compound is preferably 0.1 to 50% by mass in terms of solid content with respect to the total solid content of the image recording layer, from the viewpoint of sufficient solubility inhibiting effect and image forming property. More preferably, it is -30 mass%.

Further, when the above-described measures for improving the inhibition (solubility inhibition) are performed, the sensitivity is lowered. In this case, it is effective to add a lactone compound. This lactone compound is considered to be that when the developer penetrates into the exposed area, the developer and the lactone compound react to generate a new carboxylic acid compound, contributing to dissolution of the exposed area and improving sensitivity.
Although it does not specifically limit as a lactone compound, The compound represented by the following general formula (LI) and general formula (L-II) is mentioned.

In general formula (LI) and general formula (L-II), X ¹ , X ² , X ³ and X ⁴ are ring constituent atoms or atomic groups, which may be the same or different, and are independent of each other. And may have a substituent, and at least one of X ¹ , X ² and X ^{3 in} the general formula (LI) and X ¹ , X ² , X ³ and X in the general formula (L-II) ^At least one of ⁴ has an electron-withdrawing substituent or a substituent substituted with an electron-withdrawing group.
The constituent atoms or atomic groups of the ring represented by X ¹ , X ² , X ³ and X ⁴ are nonmetallic atoms having two single bonds for forming a ring or atomic groups containing the nonmetallic atoms.
A preferred nonmetallic atom or nonmetallic atomic group is an atom or atomic group selected from a methylene group, a sulfinyl group, a carbonyl group, a thiocarbonyl group, a sulfonyl group, a sulfur atom, an oxygen atom, and a selenium atom, and more preferably, It is an atomic group selected from a methylene group, a carbonyl group and a sulfonyl group.

At least one of X ¹ , X ² and X ^{3 in} the general formula (LI) or at least one of X ¹ , X ² , X ³ and X ^{4 in} the general formula (L-II) is an electron withdrawing group Have In the present specification, an electron-withdrawing substituent refers to a group in which Hammett's substituent constant σp takes a positive value. Regarding the Hammett's substituent constant, Journal of Medicinal Chemistry, 1973, Vol. 16, No. 11, 1207-1216, etc. can be referred to. Examples of electron-withdrawing groups in which Hammett's substituent constant σp takes a positive valence include halogen atoms (fluorine atoms (σp value: 0.06), chlorine atoms (σp value: 0.23), bromine atoms (σp value). : 0.23), iodine atom (σp value: 0.18)), trihaloalkyl group (tribromomethyl (σp value: 0.29), trichloromethyl (σp value: 0.33), trifluoromethyl (σp) Value: 0.54)), cyano group (σp value: 0.66), nitro group (σp value: 0.78), aliphatic / aryl or heterocyclic sulfonyl group (for example, methanesulfonyl (σp value: 0. 72)), aliphatic / aryl or heterocyclic acyl groups (for example, acetyl (σp value: 0.50), benzoyl (σp value: 0.43)), alkynyl groups (for example, C≡CH (σp value: 0)) .23)), Aliphatic Ali Or a heterocyclic oxycarbonyl group (for example, methoxycarbonyl (σp value: 0.45), phenoxycarbonyl (σp value: 0.44)), carbamoyl group (σp value: 0.36), sulfamoyl group (σp value: 0.57), sulfoxide groups, heterocyclic groups, oxo groups, phosphoryl groups and the like.

Preferred electron withdrawing groups are amide groups, azo groups, nitro groups, fluoroalkyl groups having 1 to 5 carbon atoms, nitrile groups, alkoxycarbonyl groups having 1 to 5 carbon atoms, acyl groups having 1 to 5 carbon atoms, and carbon numbers. An alkylsulfonyl group having 1 to 9 carbon atoms, an arylsulfonyl group having 6 to 9 carbon atoms, an alkylsulfinyl group having 1 to 9 carbon atoms, an arylsulfinyl group having 6 to 9 carbon atoms, an arylcarbonyl group having 6 to 9 carbon atoms, and thiocarbonyl A group selected from a group, a fluorine-containing alkyl group having 1 to 9 carbon atoms, a fluorine-containing aryl group having 6 to 9 carbon atoms, a fluorine-containing allyl group having 3 to 9 carbon atoms, an oxo group, and a halogen element.
More preferably, a nitro group, a fluoroalkyl group having 1 to 5 carbon atoms, a nitrile group, an alkoxycarbonyl group having 1 to 5 carbon atoms, an acyl group having 1 to 5 carbon atoms, an arylsulfonyl group having 6 to 9 carbon atoms, carbon It is a group selected from an arylcarbonyl group of formulas 9 to 9, an oxo group and a halogen element.
Specific examples of the compounds represented by formulas (LI) and (L-II) are shown below, but the present invention is not limited to these compounds.

The addition amount of the compounds represented by the general formula (LI) and the general formula (L-II) is based on the total solid content of the image recording layer in order to exhibit sufficient effects and good image forming properties. The solid content is preferably 0.1 to 50% by mass, and more preferably 1 to 30% by mass. In addition, since this compound reacts with a developing solution, it is desirable to contact a developing solution selectively.
These lactone compounds may be used alone or in combination. Two or more compounds of the general formula (LI) or two or more compounds of the general formula (L-II) may be used in an arbitrary ratio within the above range.

  In addition, a substance that is thermally decomposable, such as an onium salt, an o-quinonediazide compound, an aromatic sulfone compound, and an aromatic sulfonic acid ester compound, and that substantially reduces the solubility of the alkaline water-soluble polymer compound without being decomposed. Use in combination is preferable in terms of improving the dissolution inhibition of the image area in the developer. Examples of onium salts include diazonium salts, ammonium salts, phosphonium salts, iodonium salts, sulfonium salts, selenonium salts, and arsonium salts.

Preferred examples of the onium salt used in the present invention include SI Schlesinger, Photogr. Sci. Eng., 18, 387 (1974), TS Bal et al, Polymer, 21, 423 (1980), No. 158230, U.S. Pat.Nos. 4,069,055 and 4,069,056, ammonium salts described in JP-A-3-140140, DC Necker et al, Macromolecules, 17, 2468 (1984), CS Wen et al, Teh, Proc. Conf. Rad. Curing ASIA, p478, Tokyo, Oct (1988), U.S. Pat.Nos. 4,069,055 and 4,069,056, phosphonium salts described in JV Crivello et al, Macromolecules, 10 (6) , 1307 (1977), Chem. & Eng. News, Nov. 28, p31 (1988), European Patent No. 104,143, U.S. Pat.Nos. 339,049, 410,201, JP-A-2-150848, JP-A-2-150848 Iodonium salts described in No. 296514, JVCrivello et al, Polymer J. 17, 73 (1985), JV Crivello et al. J. Org. Chem., 43, 3055 (1978), WR Watt et al, J. Polymer Sci ., Polymer Chem. Ed. , 22, 1789 (1984), JV Crivello et al, Polymer Bull., 14, 279 (1985), JV Crivello et al, Macromolecules, 14 (5), 1141 (1981), JV Crivello et al, J. Polymer Sci , Polymer Chem. Ed., 17, 2877 (1979), European Patent Nos. 370,693, 233,567, 297,443, 297,442, U.S. Patents 4,933,377, 3,902,114, 410,201, 339,049 No. 4,760,013, No. 4,734,444, No. 2,833,827, German Patent Nos. 2,904,626, No. 3,604,580, No. 3,604,581 Selenonium salts described in JV Crivello et al, J. Polymer Sci., Polymer Chem. Ed., 17, 1047 (1979), CS Wen et al, Teh, Proc. Conf. Rad. Curing ASIA, p478, Tokyo, Oct (1988) and the like.
Of the onium salts, diazonium salts are particularly preferred. Particularly suitable diazonium salts include those described in JP-A-5-158230.

  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 assists the solubility of the sensitive material system by both the effect of losing the inhibition of dissolution of the binder by 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 compounds described in pages 339 to 352 of “Light-Sensitive Systems” by Korser 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, benzoquinone- (1,2-diazide sulfonic acid chloride or naphthoquinone- (1,2) -diazide-5 sulfonic acid chloride and phenol-formaldehyde resins described in US Pat. Nos. 3,046,120 and 3,188,210 Esters 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, No. 41-11222, No. 45-9610, No. 49-17481, U.S. Pat.No. 2,797,213, No. 3,454,400, No. 3,544,323, No. 3,573,917, No. 3,674,495, No. 3,785,825 And British Patents 1,227,602, 1,251,345, 1,267,005, 1,329,888, 1,330,932, German Patent 854,890, and the like.

The addition amount of the o-quinonediazide compound is preferably in the range of 1 to 50% by mass, more preferably 5 to 30% by mass, and particularly preferably 10 to 30% by mass with respect to the total solid content of the image recording layer. These compounds can be used alone, but may be used as a mixture of several kinds.
Further, an alkali-soluble resin at least partially esterified as described in JP-A-11-288089 may be included.

  Further, for the purpose of enhancing the dissolution inhibiting property on the surface of the image recording layer and enhancing the resistance to scratches on the surface, it is possible to improve the resistance against scratches on the surface as described in JP-A No. 2000-187318. It is preferable to use a polymer having a polymerization component of a (meth) acrylate monomer having 2 or 3 fluoroalkyl groups. As addition amount, the ratio for which it occupies in a layer material is 0.1-10 mass%, More preferably, it is 0.5-5 mass%.

-Development accelerator-
For the purpose of further improving sensitivity, acid anhydrides, phenols and organic acids can be used in combination.
As the acid anhydrides, cyclic acid anhydrides are preferable, and specific examples of the cyclic acid anhydrides include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride described in US Pat. No. 4,115,128, 3, 6-Endoxy-tetrahydrophthalic anhydride, tetrachlorophthalic anhydride, maleic anhydride, chloromaleic anhydride, α-phenylmaleic anhydride, succinic anhydride, pyromellitic anhydride and the like can be used. Examples of the non-cyclic acid anhydride include acetic anhydride.
Examples of phenols include bisphenol A, 2,2′-bishydroxysulfone, 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 .

Furthermore, examples of organic acids include sulfonic acids, sulfinic acids, alkyl sulfates, phosphonic acids, phosphate esters, and carboxylic acids described in JP-A-60-88942 and JP-A-2-96755. Specifically, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, p-toluenesulfinic acid, ethyl sulfate, phenylphosphonic acid, phenylphosphinic acid, phenyl phosphate, diphenyl phosphate, benzoic acid, isophthalic acid, Examples include adipic acid, p-toluic acid, 3,4-dimethoxybenzoic acid, phthalic acid, terephthalic acid, 4-cyclohexene-1,2-dicarboxylic acid, erucic acid, lauric acid, n-undecanoic acid, ascorbic acid and the like. .
The proportion of the acid anhydride, phenols and organic acids in the image recording layer is preferably 0.05 to 20% by mass, more preferably 0.1 to 15% by mass, and particularly preferably 0.1 to 10%. % By mass.

-Surfactant-
In the heat-sensitive layer, as described in JP-A-62-251740 and JP-A-3-208514, in order to improve the coating property and to expand the stability of processing with respect to development conditions. Nonionic surfactants, amphoteric surfactants as described in JP-A-59-121044 and JP-A-4-13149, siloxane compounds as described in EP950517, A fluorine-containing monomer copolymer as described in JP-A Nos. 62-170950, 11-288093, and 2003-057820 can be added.
Specific examples of the nonionic surfactant include sorbitan tristearate, sorbitan monopalmitate, sorbitan trioleate, stearic acid monoglyceride, polyoxyethylene nonylphenyl ether and the like. Specific examples of amphoteric activators include alkyldi (aminoethyl) glycine, alkylpolyaminoethylglycine hydrochloride, 2-alkyl-N-carboxyethyl-N-hydroxyethylimidazolinium betaine and N-tetradecyl-N, N-betaine. Type (for example, trade name “Amorgen K” manufactured by Daiichi Kogyo Co., Ltd.).
The siloxane compound is preferably a block copolymer of dimethylsiloxane and polyalkylene oxide. Specific examples include DBE-224, DBE-621, DBE-712, DBP-732, DBP-534, manufactured by Chisso Corporation. And polyalkylene oxide-modified silicones such as Tego Glide 100 manufactured by Tego, Germany.
The proportion of the nonionic surfactant and amphoteric surfactant in the image recording layer is preferably from 0.01 to 15% by mass, more preferably from 0.1 to 5% by mass, still more preferably from 0.05 to 0. 0.5% by mass.

-Bake-out agent / colorant-
In the printing plate material, a printing-out agent for obtaining a visible image immediately after heating by exposure or a dye or pigment as an image coloring agent can be added.
A representative example of the printing-out agent is 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 (above Orient Chemical Industry) Co., Ltd.), Victoria Pure Blue, Crystal Violet Lactone, Crystal Violet (CI42555), Methyl Violet (CI42535), Ethyl Violet, Rhodamine B (CI145170B), Malachite Green (CI42000), Methylene Blue (CI522015), and the like. it can. The dyes described in JP-A-62-293247 are particularly preferred.
These dyes can be added to the printing plate material in a proportion of 0.01 to 10% by mass, preferably 0.1 to 3% by mass, based on the total solid content of the image recording layer.

-Plasticizer-
Furthermore, a plasticizer is added to the printing plate material as needed to impart flexibility 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.

-Wax agent-
In the image recording layer of the photosensitive lithographic printing plate, for the purpose of imparting scratch resistance, a compound that lowers the static friction coefficient of the surface can be added. Specifically, compounds having esters of long-chain alkyl carboxylic acids, such as those used in US Pat. No. 6,117,913, JP-A 2003-149799, JP-A 2003-302750, and JP-A 2004-12770 And so on. The addition amount is preferably 0.1 to 10% by mass, more preferably 0.5 to 5% by mass in the material forming the layer.

A photosensitive lithographic printing plate can be produced by dissolving a photosensitive layer (heat-sensitive layer) composition of a plate material usually containing the above-described components in a solvent and coating the solution on a suitable support.
[Coating solvent]
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 Ethane, methyl lactate, ethyl lactate, N, N-dimethylacetamide, N, N-dimethylformamide, N-methylpyrrolidone, tetramethylurea, N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, γ-butyrolactone, toluene, water, etc. However, the present invention is not limited to this. These solvents are used alone or in combination.
When selecting the coating solvent, the coating solvent for the upper recording layer is used in order to prevent compatibility at the interface between the two layers of the upper recording layer and the lower recording layer when they are provided adjacent to each other. Is preferably selected so as not to substantially dissolve the lower recording layer. The concentration of the above components (total solid content including additives) in the solvent is preferably 1 to 50% by mass.
When using an acid anhydride, the water in the coating solution is preferably 0.5% or less.

[Amount of application]
The coating amount (solid content) of the heat-sensitive composition varies depending on the application, but it is appropriate to provide a coating amount of 0.3 to 3.0 g / m ² from the viewpoint of film properties and printing durability. . Preferably it is 0.5-2.5 g / m < ² >, More preferably, it is 0.8-1.6 g / m < ² >.

[Multilayer structure]
The photosensitive lithographic printing plate to which the present invention is applied has an image recording layer containing the above-described components provided on a support, and these image recording layers have a multilayer structure of at least two layers. (For the sake of convenience, a case of two layers consisting of an upper layer and a lower layer will be described below).
In this case, the alkali-soluble resin constituting the upper layer and the lower layer can be the alkali-soluble resin described above, but the upper layer has a lower solubility in alkali than the lower layer. Is preferred.
The infrared absorbing dye may be an infrared absorbing dye different in each layer, or an infrared absorbing dye composed of a plurality of compounds may be used in each layer. The amount to be contained is 0.01 to 50% by mass, preferably 0.1 to 50% by mass, and particularly preferably 0.1% to 50% by mass, based on the total solid content of the layer to be added, as described above, when used in any layer. It can add in the ratio of 0.1-30 mass%. When adding to a several layer, it is preferable to add so that the total of addition amount may become the said range.

In the state of being thermally decomposable and not thermally decomposable, the substance that substantially lowers the solubility of the alkali-soluble resin may be partially decomposed over time, so when the image recording layer has a multilayer structure, Although it is effective to contain it in the lower layer, it may be any layer or both layers. The amount to be contained is as described above. When adding to a several layer, it is preferable to add so that the total of addition amount may become the said range.
In the case of a multilayer structure, the lactone compound is effective to be contained in the upper layer, but it may be any layer or both layers.

[Support]
Examples of the hydrophilic support used in the photosensitive lithographic printing plate include a dimensionally stable plate having necessary strength and durability. For example, paper, plastic (for example, polyethylene, polypropylene, Paper laminated with polystyrene, etc.), metal plate (eg, aluminum, zinc, copper, etc.), plastic film (eg, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene) Terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), paper laminated with a metal as described above, or vapor-deposited paper, or plastic film.

  As the support, a polyester film or an aluminum plate is preferable. 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 mass.

  A particularly suitable aluminum is pure aluminum, but completely pure aluminum is difficult to manufacture in terms of refining technology, and may contain slightly foreign elements. Thus, the composition of the aluminum plate is not specified, and an aluminum plate made of a publicly known material can be used as appropriate. The thickness of the aluminum plate used in the present invention is about 0.1 mm to 0.6 mm, preferably 0.15 mm to 0.4 mm, and particularly preferably 0.2 mm to 0.3 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 JP-A-54-63902, a method in which both are combined can also be used.
The roughened aluminum plate is subjected to an alkali etching treatment and neutralization treatment as necessary, and then subjected to an anodization treatment to enhance the water retention and wear resistance of the surface as desired. 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 treatment conditions for anodization vary depending on the electrolyte used, and thus cannot be specified in general. In general, however, the electrolyte concentration is 1 to 80% by mass 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. The amount of the anodized film is preferably 1.0 g / m ² or more in terms of printing durability. After the anodizing treatment, the aluminum surface is subjected to a hydrophilic treatment if necessary. Examples of the hydrophilic treatment include alkali metal silicates as disclosed in US Pat. Nos. 2,714,066, 3,181,461, 3,280,734 and 3,902,734. (For example, sodium silicate aqueous solution) method. 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.

In the photosensitive lithographic printing plate, at least the above-described image recording layer is provided on a support. If necessary, an undercoat layer can be provided between the support and the image recording layer.
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, naphthyl phosphoric acid, alkyl phosphoric acid and glycerophosphoric acid which may have a substituent 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.

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 an alkyl group or Represents 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, an aryl group, or a substituted aryl. Represents a group, or R ¹⁸ and R ¹⁹ may combine to form a ring, and m represents an integer of 1 to 3.

This undercoat layer 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, then washed with water or the like and dried to provide an undercoat layer. In the former method, a solution having a concentration of 0.005 to 10% by mass 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 mass, preferably 0.05 to 5% by mass, 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.
The coating amount of the undercoat layer is suitably ² to 200 mg / m ² , preferably 5 to 100 mg / m ² in order to obtain sufficient printing durability.

The photosensitive lithographic printing plate prepared as described above is exposed imagewise and then developed with the alkaline developer described in detail above.
Examples of the active light source used for image exposure include a mercury lamp, a metal halide lamp, a xenon lamp, a chemical lamp, and a carbon arc lamp. Examples of radiation include electron beams, X-rays, ion beams, and far infrared rays. Also, g-line, i-line, deep-UV light, and high-density energy beam (laser beam) are used. Examples of the laser beam include a helium / neon laser, an argon laser, a krypton laser, a helium / cadmium laser, and a KrF excimer laser. In the present invention, a light source having an emission wavelength in the near infrared to infrared region is preferable, and a solid laser or a semiconductor laser is particularly preferable.

  If the lithographic printing plate obtained by image exposure, development, washing and / or rinsing and / or gumming has an unnecessary image area, the unnecessary image area 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 obtain a lithographic printing plate with higher printing durability, Processing is performed. In the case of burning a lithographic printing plate, before burning, the preparations described in JP-B-61-2518, JP-A-55-28062, JP-A-1-31859, and JP-A-61-159655 are prepared. It is preferable to treat with a surface liquid.
As the method, it is possible to apply a lithographic printing plate with a sponge or absorbent cotton soaked with the surface-adjusting liquid, or immerse the printing plate in a vat filled with the surface-adjusting liquid, or apply an automatic coater. Application by, for example, 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 from 0.03 to 0.8 g / m ² (dry weight). The lithographic printing plate coated with the surface-adjusting liquid 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.). . 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 subjected to burning treatment can be subjected to conventional treatments such as washing with water 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 lithographic printing plate obtained by such treatment is applied to an offset printing machine and used for printing a large number of sheets.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not restrict | limited to these. In the examples, “%” represents “% by mass”.
<Preparation of photosensitive lithographic printing plate>
A 0.3 mm thick aluminum plate (material 1050) was washed with trichlorethylene and degreased, and then a nylon brush and 400 mesh pumice-water suspension were used to make the surface grainy and washed thoroughly with water. After washing, this aluminum plate was etched by immersing it in a 25% aqueous sodium hydroxide solution at 45 ° C. for 9 seconds, washed with water, further immersed in a 20% nitric acid aqueous solution for 20 seconds, and washed again with water. At this time, the etching amount of the grained surface was about 3 g / m ² . Next, the aluminum plate was provided with an anodized film of 3 g / m ² with a direct current of 15 A / dm ² using 7% sulfuric acid as an electrolytic solution, and then washed and dried. This was treated with a 2.5% aqueous solution of sodium silicate at 30 ° C. for 10 seconds, the following undercoat layer coating solution was applied, and dried at 80 ° C. for 15 seconds to obtain a support. The dry coating amount of the undercoat layer after drying was 15 mg / m ² .

<Coating liquid for undercoat layer>
The following copolymer P (molecular weight 28000) 0.3 g
Methanol 100g
1g of water
Copolymer P

<Synthesis of specific copolymer>
Synthesis example (specific copolymer 1)
A 500 ml three-necked flask equipped with a stirrer, a condenser and a dropping funnel is charged with 31.0 g (0.36 mol) of methacrylic acid, 39.1 g (0.36 mol) of ethyl chloroformate and 200 ml of acetonitrile and cooled in an ice-water bath The mixture was stirred while. To this mixture, 36.4 g (0.36 mol) of triethylamine was dropped with a dropping funnel over about 1 hour. After completion of the dropwise addition, the ice-water bath was removed, and the mixture was stirred at room temperature for 30 minutes. To this reaction mixture, 51.7 g (0.30 mol) of p-aminobenzenesulfonamide was added, and the mixture was stirred for 1 hour while warming to 70 ° C. in an oil bath. After completion of the reaction, this mixture was added to 1 liter of water with stirring, and the resulting mixture was stirred for 30 minutes. The mixture was filtered to take out a precipitate, which was slurried with 500 ml of water, and then the slurry was filtered, and the resulting solid was dried to give white N- (p-aminosulfonylphenyl) methacrylamide. A solid was obtained (yield 46.9 g).
Next, 4.61 g of N- (p-aminosulfonylphenyl) methacrylamide (0.0192 mol) and 2.94 g of ethyl methacrylate (0.0258) were added to a 20 ml three-necked flask equipped with a stirrer, a condenser and a dropping funnel. Mol), 0.80 g (0.015 mol) of acrylonitrile and 20 g of N, N-dimethylacetamide were added, and the mixture was stirred while heating to 65 ° C. with a hot water bath. To this mixture, 0.15 g of “V-65” (manufactured by Wako Pure Chemical Industries, Ltd.) was added, and the mixture was stirred for 2 hours under a nitrogen stream while being kept at 65 ° C. To this reaction mixture was further added a mixture of 4.61 g of N- (p-aminosulfonylphenyl) methacrylamide, 2.94 g of ethyl methacrylate, 0.80 g of acrylonitrile, N, N-dimethylacetamide and 0.15 g of “V-65”. It dropped by the dropping funnel over 2 hours. After completion of the dropwise addition, the resulting mixture was further stirred at 65 ° C. for 2 hours. After completion of the reaction, 40 g of methanol is added to the mixture, the mixture is cooled, and the resulting mixture is poured into 2 liters of water while stirring the water. After stirring the mixture for 30 minutes, the precipitate is removed by filtration and dried. Gave 15 g of a white solid. It was 53,000 when the weight average molecular weight (polystyrene standard) of this specific copolymer was measured by the gel permeation chromatography.

The following image recording layer coating solution was applied onto the obtained support so that the dry coating amount was 1.8 g / m ² to obtain a positive-type infrared-sensitive lithographic printing plate.
<Coating liquid for image recording layer>
0.4 g of the above specific copolymer
0.6 g of m, p-cresol novolak
(M / p ratio = 6/4, weight average molecular weight 8000,
0.5% unreacted cresol)
Cyanine dye A 0.1g
Phthalic anhydride 0.05g
0.002 g of p-toluenesulfonic acid
Ethyl violet 0.02g
(Counterion: 6-hydroxy-β-naphthalenesulfonic acid)
0.01 g of esterified product of naphthoquinone 1,2-diazide-5-sulfonylcroid and pyrogallol-acetone resin
Fluorosurfactant 0.05g
(Product name: Megafuck F-177, manufactured by Dainippon Ink & Chemicals, Inc.)
Methyl ethyl ketone 8g
1-methoxy-2-propanol 4g

[Preparation of developer]
<Preparation of development starter containing SiO ₂ >
To the 5.0% aqueous solution of potassium silicate having a mixing ratio of silicon oxide SiO ₂ and potassium oxide K ₂ O of 1.1, the compound represented by the general formula (I) is added at various concentrations, and Developers (1) to (34) were produced.
On the other hand, a comparative developer (1) in which the compound represented by the general formula (I) is not added, and a comparative developer in which C ₈ H ₁₇ NHCH ₂ CH ₂ COOH is added without adding the compound represented by the general formula (I) (2) was produced.

<Preparation of development initiator containing non-reducing sugar>
A compound represented by formula (I) is added to a 5.0% aqueous solution of potassium salt composed of D-sorbite / potassium oxide K ₂ O, which is a combination of a non-reducing sugar and a base, at various concentrations, and the present invention. Developers (35) to (64) were prepared.
On the other hand, a comparative developer (3) in which the compound represented by the general formula (I) is not added and a comparative developer in which C ₈ H ₁₇ NHCH ₂ CH ₂ COOH is added without adding the compound represented by the general formula (I) (4) was produced.
The structure of the compound represented by the general formula (I) used for the preparation of the developer is shown in Table 1 below. Further, Table 2 and Table 3 show the concentration (mass%) of the compound represented by the general formula (I) and the concentration (mass%) of C ₈ H ₁₇ NHCH ₂ CH ₂ COOH in various developing solutions.

<Preparation of development replenisher>
As a developer replenisher used for each of the developers (1) to (34), the comparative developer (1), and the comparative developer (2), the mixing ratio of silicon oxide SiO ₂ and potassium oxide K ₂ O is 1.1. As shown in Table 2, a 6.5% aqueous solution of potassium silicate containing various compounds at a predetermined concentration was prepared.
Further, as a developer replenisher used in each of the developers (35) to (64), the comparative developer (3), and the comparative developer (4), D-sorbite / potassium oxide K in which a non-reducing sugar and a base are combined. _A potassium salt 6.5% aqueous solution containing ₂ O was prepared by containing various compounds at predetermined concentrations as shown in Table 3 according to each developer.

The lithographic printing plate precursor obtained above was exposed at a main scanning speed of 5 m / sec using a semiconductor laser having an output of 500 mW and a wavelength of 830 nm and a beam diameter of 17 μm (1 / e ² ) and kept at 25 ° C. This lithographic printing plate precursor was developed with an automatic processor PS900NP (manufactured by Fuji Photo Film Co., Ltd.) filled with the above-mentioned various developing solutions at 30 ° C. for 12 seconds. The replenishment conditions of the development replenisher were 40 ml per 1 m ² of the lithographic printing plate, 200 ml / hour when the automatic processor was operating, and 100 ml / hour when stopped, and an average throughput of 50 m ² per day.
After completion of the development treatment, a lithographic printing plate in which plate making was completed was obtained through a water washing step and treatment with gum GU-7 (1: 1) or the like.
For the planographic printing plate obtained after 6 months under the above development processing conditions and replenishment conditions, as an evaluation of the balance between the image area / non-image area, evaluation of developability of the non-image area and evaluation of film slippage of the image area And insoluble substances in various developing solutions were evaluated. The evaluation method is as follows.

<Evaluation of balance between image area / non-image area>
(Evaluation of developability of non-image area)
The developability of the non-image area of the lithographic printing plate obtained as described above was calculated from the density measured by the GRETAG densitometer of the non-image area as follows and digitized.
Expression: Actual measurement value-original support density This value is preferably zero or close to zero as the developability of the non-image area.
(Evaluation of film slippage in the image area)
Defects in the image area of the lithographic printing plate obtained as described above were calculated as follows by means of density measurement with a GRETAG densitometer and digitized.
Formula: Image part density before development-Image part density at the same position after development The smaller this value, the less the film is filmed in the image part.

<Evaluation of insoluble matter in developer>
The developer treated with 1000 m ² per liter of various developers was observed and evaluated when it was left in a refrigerator (5 ° C.), room temperature (20-25 ° C.), and thermo (35 ° C.) for 6 months.
○: There is no insoluble matter.
○ to Δ: There are some insolubles, but they will not dissolve if shaken lightly.
Δ: Slightly insoluble, but no longer dissolved when shaken strongly.
X: Insoluble matter remains even if shaken.
These results are shown together in Tables 2 and 3.

* Ｃ₈Ｈ₁₇ＮＨＣＨ₂ＣＨ₂ＣＯＯＨ

* C ₈ H ₁₇ NHCH ₂ CH ₂ COOH

* Ｃ₈Ｈ₁₇ＮＨＣＨ₂ＣＨ₂ＣＯＯＨ

* C ₈ H ₁₇ NHCH ₂ CH ₂ COOH

Claims (4)

  An alkaline developer for a photosensitive lithographic printing plate comprising an alkylene oxide adduct of a carboxylic acid alkanolamide. 2. The alkaline developer for photosensitive lithographic printing plates according to claim 1, wherein the alkylene oxide adduct of carboxylic acid alkanolamide is at least one of the following general formula (I).

(In the formula, R ¹ represents a hydrocarbon group having 4 to 32 carbon atoms, and R ² represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or — (B—O) m—H (B—O). Represents at least one group selected from an oxyethylene group, an oxypropylene group, an oxybutylene group and an oxystyrene group, m represents an integer of 1 to 100), and A-O represents an oxyethylene group and an oxypropylene group. Represents at least one group selected from a group, an oxybutylene group and an oxystyrene group, and n represents an integer of 1 to 100.)   A method for making a lithographic printing plate, comprising developing the photosensitive lithographic printing plate with the alkaline developer according to claim 1 after exposure.   The lithographic printing plate making process according to claim 3, wherein the photosensitive lithographic printing plate has a photosensitive layer on a support, and the photosensitive layer is an infrared photosensitive lithographic printing plate containing an infrared absorbing dye and an alkali-soluble resin. Method.