JP2015014719A - Photosensitive lithographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive lithographic printing plate which makes it possible to obtain sufficient net entanglement resistance even in the case when performing lithography by repeatedly conducting printing and stopping a machine without causing reduction in printing durability.SOLUTION: A photosensitive lithographic printing plate at least has, on a support, a hydrophilic layer comprising hydrophilic binder, inorganic filler, and polyoxyethylene alkyl ether, and on the hydrophilic layer, a photopolymerizable photosensitive layer comprising a trihaloalkyl substituted compound.

Description

  The present invention relates to a photosensitive lithographic printing plate having a hydrophilic layer and a photopolymerizable photosensitive layer on a support.

  As a lithographic printing plate support, an aluminum plate having a roughened surface such as a PS plate and having an anodized film is widely used. On the other hand, a lithographic printing plate material using a paper or film as a support. Is widely used.

  In recent years, CTP has been fully digitized by expansion of JDF (abbreviation of Job Definition Format), and work efficiency has been greatly improved. However, thermal and photopolymer type CTP printing plates, which are currently mainstream, use a developer containing a strong alkaline agent to elute and remove non-image areas after laser exposure of the printing plate, and then wash and gum. These processes are generally performed, and there is a demand for conversion to a system that takes into account human health and the environment as well as improving the efficiency of these processes. For this reason, the technical development of the system aiming at so-called chemical-free which eliminates chemicals as much as possible from the developer of the CTP printing plate and no processing which does not require the developing process itself is actively carried out.

  There has been proposed a photosensitive lithographic printing plate that avoids the use of a developer containing a strong alkali agent and can be developed with water or the like. For example, Japanese Patent Application Laid-Open No. 2003-215801 (Patent Document 1) discloses a roughened aluminum support having an anodized film and further having a silicate treatment, and a support having a hydrophilic layer on a plastic film. A cationic water-soluble polymer having a phenyl group substituted with a vinyl group on the side chain, or a water-soluble polymer having a phenyl group substituted with a vinyl group on the side chain and a sulfonate group, and a photopolymerization initiator or A photosensitive lithographic printing plate having a photosensitive layer containing an acid generator is disclosed.

  Further, as a hydrophilic layer of a photosensitive lithographic printing plate that can be developed with water or the like and can be developed chemically, for example, Japanese Patent Application Laid-Open No. 2008-265297 (Patent Document 2) and Japanese Patent Application Laid-Open No. 2008-233820. Publication (Patent Document 3), JP 2010-234723 A (Patent Document 4), JP 2013-88670 A (Patent Document 5), etc., a hydrophilic material containing a hydrophilic binder and an inorganic filler on a support. A layer is disclosed.

  However, when the photopolymerizable photosensitive layer provided on the hydrophilic layer contains a trihaloalkyl-substituted compound, depending on the printing conditions, a phenomenon called so-called network entanglement, in which the smear occurs in the shadow part, is particularly likely to occur. It was sought after. The above-mentioned Patent Document 5 is an invention in which the solution of the network entanglement is one of the problems. However, when lithographic printing is performed by repeating printing and stopping, sufficient network proof resistance cannot be obtained, and further There was a need for improvement.

  On the other hand, Japanese Unexamined Patent Publication No. 2000-158839 (Patent Document 6) discloses a hydrophilic layer excellent in hydrophilic sustainability and stain recovery, and can improve the coating property of the hydrophilic layer. Examples of such surfactants include anionic surfactants such as alkylbenzene sulfonates and alkylsulfosuccinates, and nonionic surfactants such as polyoxyethylene alkylamines and polyoxyethylene alkyl ethers.

JP 2003-215801 A JP 2008-265297 A JP 2008-233820 A JP 2010-234723 A JP 2013-88670 A JP 2000-158839 A

  An object of the present invention is to provide a photosensitive lithographic printing plate capable of obtaining sufficient halftoning resistance even when lithographic printing is performed by repeating printing and stopping without reducing printing durability.

The present invention has been achieved by the following invention.
1) At least a hydrophilic layer containing a hydrophilic binder, an inorganic filler, and a polyoxyethylene alkyl ether on a support, and a photopolymerizable photosensitive layer containing a trihaloalkyl-substituted compound on the hydrophilic layer. Photosensitive lithographic printing plate.

  According to the present invention, it is possible to provide a photosensitive lithographic printing plate that can obtain sufficient reticulation resistance even when lithographic printing is performed by repeating printing and stopping without reducing printing durability.

  Hereinafter, the present invention will be described in detail.

<Support>
Examples of the support of the photosensitive lithographic printing plate of the present invention include a metal plate represented by an aluminum plate, an aluminum plate having a roughened surface and an anodized film, and a plastic film. Among these, a flexible plastic film is preferable because it can be stored in an exposure apparatus in a compact form as a roll.

  Typical examples of the plastic film include polyethylene terephthalate, polyethylene naphthalate, polyethylene, polypropylene, polystyrene, polyvinyl acetal, polycarbonate, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, and cellulose nitrate. Also, paper laminated by the above method may be used. Among them, various plastic films that are flexible and are less deformed by tension are preferably used. As a preferable plastic film substrate, polyethylene terephthalate, polyethylene naphthalate, paper laminated with plastic is particularly preferably used.

  The surface of these plastic films may be surface-treated in order to improve adhesion with a backing layer or the like provided as necessary in addition to the hydrophilic layer. Examples of such surface treatment include corona discharge treatment, flame treatment, plasma treatment, and ultraviolet irradiation treatment. As a further surface treatment, an undercoat layer may be provided on the plastic film in order to enhance the adhesion with the hydrophilic layer provided on the plastic film.

<Hydrophilic layer>
The photosensitive lithographic printing plate of the present invention has a hydrophilic layer on a support, and the hydrophilic layer contains at least a hydrophilic binder, an inorganic filler, and a polyoxyethylene alkyl ether.

<Polyoxyethylene alkyl ether>
The hydrophilic layer of the photosensitive lithographic printing plate of the present invention contains polyoxyethylene alkyl ether.

The polyoxyethylene alkyl ether used in the present invention has a structure represented by R—O (CH ₂ CH ₂ O) _n —H, and R is linear or branched having an average carbon number of 8 to 16. A compound which is an alkyl group and n is 2 to 18 is preferably used. The more preferable carbon number of R is 11-16, More preferably, it is 12-14. Moreover, it is more preferable that the addition mole number n of ethylene oxide is 4-15. Examples of such compounds include NIKKOL BT-7, BT-9, and BT-11 from Nikko Chemicals Co., Ltd., and Neugen ET-115, ET-135, ET-165, and TDS from Daiichi Kogyo Seiyaku Co., Ltd. Since it is commercially available as -80, DKS NL-70, etc., these can be obtained and used.

  The addition amount of the polyoxyethylene alkyl ether is preferably 0.5 to 20% by mass, more preferably 2 to 10% by mass, based on the hydrophilic polymer in the hydrophilic layer.

<Inorganic filler>
Examples of the inorganic filler contained in the hydrophilic layer of the present invention include calcium carbonate, magnesium carbonate, zinc oxide, titanium dioxide, barium sulfate, aluminum hydroxide, zinc hydroxide, colloidal silica, pore silica, and kaolin. . Of these, titanium dioxide, barium sulfate, aluminum hydroxide, and colloidal silica are preferable.

  Titanium dioxide may be either a rutile type or an anatase type, and the production method is not limited to either the sulfuric acid method or the chlorine method. You may use them individually or in mixture. Furthermore, from the viewpoint of dispersion stability and other functionality, it is possible to selectively use those subjected to various surface treatments. Examples of commercially available titanium dioxide include SR-1, R-650, R-5N, R-7E, R-3L, A-110, and A-190 from Sakai Chemical Industry Co., Ltd. ) From Taipei R-580, R-930, A-100, A-220, CR-58, Titanium Industry Co., Ltd., Kronos KR-310, KR-380, KA-10, KA -20 etc., Teica Co., Ltd., Titanics JR-301, JR-600A, JR-800, JR-701 etc., DuPont Co., Ltd. Taipure R-900, R-931 etc. are mentioned.

  As barium sulfate, it is preferable to use precipitated barium sulfate produced by adding a sulfate aqueous solution to a barium chlorine solution and chemically precipitating. Precipitated barium sulfate is commercially available, for example, as “Variace” from Sakai Chemical Industry Co., Ltd., having various particle diameters or surface-treated ones, but any of them can be used in the present invention.

  Aluminum hydroxide mixes bauxite, which is an ore containing alumina, with caustic soda or sodium aluminate solution, extracts the alumina component under high temperature and high pressure conditions, separates and removes red mud as a dissolution residue from the extract, A clarified sodium aluminate solution is obtained. Thereafter, seeds can be added to the solution to crystallize aluminum hydroxide, and the obtained aluminum hydroxide can be pulverized. Various grades of aluminum hydroxide are commercially available from Showa Denko Co., Ltd. as “Hijilite”, and any grade can be used in the present invention.

  The colloidal silica used in the present invention may have a spherical shape, and a chain or pearl necklace colloidal silica is also preferably used.

The colloidal silica may be composed of a simple substance of SiO ₂ , but it is also possible to use a silica whose surface is slightly modified with Al ₂ O ₃ or the like in order to change the pH dependence of the dispersibility of silica. Further, an alkali dispersion or an acidic dispersion of colloidal silica can be selected and used depending on the pH of the coating liquid for the hydrophilic layer.

  Examples of the spherical silica include “Snowtex XS”, “Snowtex S”, “Snowtex 20”, “MP-2040”, “MP-1040”, and “Snowtex ZL” manufactured by Nissan Chemical Industries, Ltd. Etc. These colloidal silicas have a pH of 9 or more, but when preparing an acidic coating solution, it is possible to use “Snowtex O”, “Snowtex OL”, etc., which are made by demineralizing Na ions to make them acidic. it can. Examples of the chain silica include “Snowtex UP” manufactured by Nissan Chemical Industries, Ltd., and examples of the necklace-like silica include “Snowtex PS-S” and “Snowtex PS-M”.

  Further, the inorganic filler contained in the hydrophilic layer is present in the range of the particle size distribution of the inorganic filler in the range of 0.2 to 0.6 μm and the range of 0.6 to 1.5 μm, and the 0.2 to 0 When the distribution frequency of the inorganic filler existing in the range of less than 6 μm is fx and the distribution frequency of the inorganic filler existing in the range of 0.6 μm or more and less than 1.5 μm is fy, the fx / fy ratio is 1.5 or more. More preferably, the distribution frequency fy is 25% or more. The fx / fy ratio is preferably 2.0 or more, and the upper limit of the fx / fy ratio is preferably less than 3.5. In the above-mentioned range, for example, when a plurality of peaks are present in the range of 0.2 μm or more and less than 0.6 μm, the distribution frequency fx may be obtained with the higher peak. In the case where the height of the recess between two peaks is 60% or more of the higher peak, it is regarded as one peak in the present invention.

  The particle size distribution in the present invention is a volume-based particle size distribution, which is an index indicating what kind of particle size the sample particle group to be measured is and what ratio is configured, and is generally known It can be measured by the method. For example, a sieving method, a Coulter method (Coulter principle), a dynamic light scattering method, an image analysis method, a laser diffraction scattering method, etc. are known as the measuring method. In the present invention, the particle size to be measured and reproducibility are known. From the viewpoint of operability and the like, a laser diffraction / scattering method is preferably used. For example, it can be measured by LA-920 (laser diffraction / scattering type particle size distribution measuring apparatus) manufactured by Horiba, Ltd. The distribution frequency can be obtained as a distribution of the existence ratio for each size (particle diameter) based on the measurement result.

  The particle size distribution and distribution frequency in the present invention are measured by measuring the inorganic filler dispersed in the coating solution, or by measuring the inorganic filler in a solution obtained by re-dissolving the dried coating film of the applied hydrophilic layer with an alkali. You can ask for it. As will be described later, in the present invention, two or more kinds of inorganic fillers can be used together. However, in the laser diffraction scattering method preferably used in the present invention, the light intensity distribution pattern is obtained from the Fraunhofer diffraction theory and the Mie scattering theory. Therefore, a refractive index specific to the object is required, and it is difficult to accurately measure the particle size distribution and distribution frequency of a coating liquid containing two or more inorganic fillers having different refractive indexes. However, in such a case, the particle size distribution and distribution frequency of each inorganic filler alone are measured in advance, and two or more kinds of inorganic fillers are added by multiplying the obtained measurement result by the addition ratio in the coating liquid as a coefficient. The particle size distribution and distribution frequency of the coating liquid used in combination can be determined.

  In order to obtain the particle size distribution of the inorganic filler described above, an inorganic filler having an average primary particle size of 0.1 μm or more and less than 0.6 μm and an inorganic filler having an average primary particle size of 0.6 μm or more and less than 2.0 μm are combined. It is preferable to use it, and if it is such a combination, the inorganic filler may be further used in combination with three or four kinds. The addition amount of the inorganic filler is preferably 60% by mass or more, more preferably 70% by mass or more, based on the total solid content of the hydrophilic layer.

  Further, in the hydrophilic layer having the above particle size distribution, it is preferable not to use silicon-containing compounds such as colloidal silica, pore silica, and kaolin, and the content of these silicon-containing compounds is reduced to the total inorganic filler in the hydrophilic layer. Is preferably 5% by mass or less, more preferably 3% by mass or less, particularly preferably 1% by mass or less, and particularly preferably 0.5% by mass or less.

<Hydrophilic binder>
As the hydrophilic binder used in the hydrophilic layer of the photosensitive lithographic printing plate of the present invention, natural products obtained from algae such as starch, seaweed mannan, agar and sodium alginate, mannan, pectin, tragacanth gum, karaya gum , Plant mucilage such as xanthine gum, guar bin gum, locust bin gum, gum arabic and the like, homopolysaccharides such as dextran, glucan, xanthan gum and levan, microorganisms such as heteropolysaccharides such as succinoglucan, pullulan, curdlan and xanthan gum Examples include mucilage, glue, protein such as gelatin, casein and collagen, chitin and derivatives thereof. Semi-natural products (semi-synthetic products) include cellulose derivatives, modified gums such as carboxymethyl guar gum, cultured starches such as dextrin, processed starches such as oxidized starches and esterified starches. . On the other hand, synthetic products include polyvinyl alcohol, partially acetalized polyvinyl alcohol, allyl-modified polyvinyl alcohol, modified polyvinyl alcohols such as polyvinyl methyl ether, polyvinyl ethyl ether, and polyvinyl isobutyl ether, polyacrylates, and polyacrylate ester partial saponified products. , Polymethacrylic acid derivatives and polymethacrylic acid derivatives such as polymethacrylic acid salts and polyacrylamides, polyethylene glycol, polyethylene oxide, polyvinylpyrrolidone, vinylpyrrolidone / vinyl acetate copolymer, carboxyvinyl polymer, styrene / maleic acid copolymer Examples thereof include a polymer, a styrene / crotonic acid copolymer, and a water-soluble polymer described in JP-A No. 2008-265297. Among these, gelatin is preferably used.

  Moreover, content of the hydrophilic binder in a hydrophilic layer has a preferable content ratio between the said inorganic fillers, and it is preferable that it is 5-30 mass% with respect to 100 mass parts of all inorganic fillers, and 10-25 masses. % Is more preferable. When it exceeds 30% by mass, the filler filling density is lowered and sufficient hydrophilicity cannot be imparted, and the soil resistance and the entanglement resistance may be lowered. On the other hand, if it is less than 5% by mass, the handling property of the coating liquid may be lowered, or cracks may occur after forming the hydrophilic layer.

<Crosslinking agent>
The hydrophilic layer of the photosensitive lithographic printing plate of the present invention preferably contains a crosslinking agent. As the crosslinking agent to be used, for example, melamine resin, polyisocyanate compound, aldehyde compound, silane compound, chromium alum, epoxy compound, divinyl sulfone and the like can be suitably used, but particularly preferred crosslinking when the hydrophilic binder is gelatin. The agent is divinyl sulfone, and a particularly preferable crosslinking agent is an epoxy compound when polyacrylic acid and a copolymer thereof, polymethacrylic acid and a copolymer thereof, polyvinyl alcohol, and the like. The epoxy compound is sold, for example, under the trade name “Denacol” from Nagase ChemteX Corporation and can be easily obtained. The blending amount of the crosslinking agent is preferably 5 to 35% by mass, more preferably 10 to 25% by mass, based on the solid content of the hydrophilic binder. As a method for adding the crosslinking agent, there are a method of adding the hydrophilic layer coating liquid when it is manufactured, a method of adding it in-line immediately before coating, and any method may be used.

  In order to sufficiently crosslink the hydrophilic layer, for example, 0.5 to 0.5 at a temperature of 30 to 60 ° C., preferably 40 to 50 ° C., between the formation of the hydrophilic layer and the application of the photopolymerizable photosensitive layer. It is preferable to perform a heating treatment for 10 days, preferably 1 to 7 days. Such a heating process exposes the hydrophilic layer by a development process after exposure, and even if it is subjected to printing as a non-image part at the time of printing, it is natural that printability is sufficient, but also from the viewpoint of scratch resistance. Performance can be realized.

<Photopolymerizable photosensitive layer>
The photosensitive lithographic printing plate of the present invention has at least a photopolymerizable photosensitive layer on the hydrophilic layer. Such a photosensitive layer contains a trihaloalkyl-substituted compound as a photopolymerization initiator.

<Trihaloalkyl-substituted compound>
The trihaloalkyl-substituted compound used in the present invention is specifically a compound having at least one trihaloalkyl group such as a trichloromethyl group or a tribromomethyl group in the molecule. As a preferable example, the trihaloalkyl group includes Examples of the compound bonded to the nitrogen-containing heterocyclic group include s-triazine derivatives and oxadiazole derivatives, or a trihaloalkylsulfonyl compound in which the trihaloalkyl group is bonded to an aromatic ring or a nitrogen-containing heterocyclic ring via a sulfonyl group. Is mentioned.

  Particularly preferred examples of compounds in which a trihaloalkyl group is bonded to a nitrogen-containing heterocyclic group and trihaloalkylsulfonyl compounds are shown below.

  The content of the above-described trihaloalkyl-substituted compound is preferably in the range of 0.1 to 40% by mass, and more preferably in the range of 1 to 20% by mass with respect to the compound having a polymerizable double bond group described later. It is preferable.

  The photopolymerizable photosensitive layer can contain other photopolymerization initiator in addition to the above-described trihaloalkyl-substituted compound. As such a photopolymerization initiator, conventionally known compounds can be used, and examples thereof include organic boron salts, hexaarylbiimidazoles, titanocene compounds, thio compounds, and organic peroxides. . Among these photopolymerization initiators, it is particularly preferable to combine an organic boron salt and a trihaloalkyl-substituted compound, and high sensitivity can be achieved.

  The organoboron anion constituting the organoboron salt is represented by the following general formula 1.

In the formula, each of R ₁ , R ₂ , R ₃ and R ₄ may be the same or different, and represents an alkyl group, aryl group, aralkyl group, alkenyl group, alkynyl group, cycloalkyl group or heterocyclic group. Represent. Of these, it is particularly preferred that one of R ₁ , R ₂ , R ₃ and R ₄ is an alkyl group and the other substituent is an aryl group.

  Examples of the cation constituting the organic boron salt include alkali metal ions and onium compounds, but onium salts are preferred, for example, ammonium salts such as tetraalkylammonium salts, sulfonium salts such as triarylsulfonium salts, and triarylalkyls. Examples thereof include phosphonium salts such as phosphonium salts. Examples of particularly preferred organic boron salts are shown below.

  The content of the photopolymerization initiator that can be used in combination with the above-described trihaloalkyl-substituted compound is 1 to 50 with respect to the compound having a polymerizable double bond group described later as the content combined with the trihaloalkyl-substituted compound. The range of mass% is preferable, and it is more preferable that it be included in the range of 5 to 30 mass%.

<Compound having a polymerizable double bond group>
The photopolymerizable photosensitive layer preferably contains a compound having a polymerizable double bond group. Examples of the compound having a polymerizable double bond group in the present invention include a polymer compound having a polymerizable double bond group or a low molecular compound having a polymerizable double bond group. It is preferable from the viewpoint of photopolymerization efficiency to use a high molecular compound having a low molecular weight compound having a polymerizable double bond group.

  The polymer compound having a polymerizable double bond group will be described. The polymer compound having a polymerizable double bond group is a polymer compound formed by an arbitrary repeating unit, and a polymer compound in which a polymerizable double bond group is bonded to a side chain through an arbitrary linking group. It is. Among them, a polymer compound having a vinyl group as a polymerizable double bond group is preferably used, and a polymer compound in which a phenyl group substituted with a vinyl group is bonded to the main chain directly or via an arbitrary linking group is particularly preferably used. It is done. In addition, in order to enable development with an alkaline developer or a neutral developer (chemicalless developer), a carboxyl group, a sulfonic acid group, a quaternary ammonium group, etc., which are connected to the main chain via an arbitrary connecting group However, among them, a polymer compound having a sulfonic acid group can be preferably used because of its high developability. The sulfonic acid group may form a salt (for example, sodium salt, potassium salt, lithium salt, ammonium salt, etc.). These linking groups are not particularly limited, and include any group, atom, or a combination thereof. The phenyl group and sulfonic acid group substituted with a vinyl group may be independently bonded to the main chain, or the phenyl group and sulfonic acid group substituted with a vinyl group share part or all of the linking group. You may combine in the form to do.

  In the phenyl group substituted by the vinyl group, the phenyl group may be substituted, and the vinyl group is a halogen atom, carboxyl group, sulfo group, nitro group, cyano group, amide group, amino group, alkyl group. , An aryl group, an alkoxy group, an aryloxy group and the like may be substituted.

  The polymer compound in which the phenyl group substituted with the vinyl group of the present invention is bonded to the main chain directly or through an arbitrary linking group has, in detail, one having a group represented by the following general formula 2 in the side chain. preferable.

In the formula, R ₅ , R ₆ and R ₇ may be the same or different and are each a hydrogen atom, halogen atom, carboxyl group, sulfo group, nitro group, cyano group, amide group, amino group, alkyl group. Group, aryl group, alkoxy group, aryloxy group, alkylsulfanyl group, arylsulfanyl group, alkylamino group, arylamino group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, alkylsulfonyl group, arylsulfonyl group An alkyl group and an aryl group constituting these groups are a halogen atom, a carboxyl group, a sulfo group, a nitro group, a cyano group, an amide group, an amino group, an alkyl group, an aryl group, an alkenyl group, a hydroxy group, Alkoxy group, aryloxy group, alkylsulfanyl group, It may be substituted with a reelsulfanyl group, an alkylamino group, an arylamino group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, or the like. Among these groups, those in which R ₅ and R ₆ are hydrogen atoms and R ₇ is a hydrogen atom or a lower alkyl group having 4 or less carbon atoms (for example, a methyl group, an ethyl group, etc.) are particularly preferable.

In the formula, R ₈ is hydrogen atom, halogen atom, carboxyl group, nitro group, cyano group, amide group, amino group, alkyl group, aryl group, alkoxy group, aryloxy group, alkylsulfanyl group, arylsulfanyl group, alkylamino. And a group selected from a group, an arylamino group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylsulfonyl group, and an arylsulfonyl group. The alkyl group and aryl group constituting these groups are halogen atom, carboxyl group, sulfo group, nitro group, cyano group, amide group, amino group, alkyl group, aryl group, alkenyl group, alkynyl group, hydroxy group. , Alkoxy groups, aryloxy groups, alkylsulfanyl groups, arylsulfanyl groups, alkylamino groups, arylamino groups, acyl groups, alkoxycarbonyl groups, aryloxycarbonyl groups, alkylsulfonyl groups, arylsulfonyl groups, etc. good.

In the formula, L ₁ represents an atom selected from a carbon atom, a nitrogen atom, an oxygen atom and a sulfur atom, or a polyvalent linking group consisting of an atom group selected from a hydrogen atom, a carbon atom, a nitrogen atom, an oxygen atom and a sulfur atom. Represent. Specific examples include groups composed of the structural units exemplified below and the heterocyclic groups shown below. These groups may be used alone or in any combination of two or more.

The linking group L ₁ preferably includes a heterocyclic ring. Examples of the heterocyclic ring constituting L ₁ include pyrrole ring, pyrazole ring, imidazole ring, triazole ring, tetrazole ring, isoxazole ring, oxazole ring, oxadiazole ring, isothiazole ring, thiazole ring, thiadiazole ring, thiazole Triazole ring, indole ring, indazole ring, benzimidazole ring, benzotriazole ring, benzoxazole ring, benzthiazole ring, benzselenazole ring, benzothiadiazole ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, triazine ring, quinoline And a nitrogen-containing heterocycle such as a ring and a quinoxaline ring, a furan ring, a thiophene ring, and the like. These heterocycles may have a substituent.

  When the polyvalent linking group described above has a substituent, examples of the substituent include a halogen atom, a carboxyl group, a sulfo group, a nitro group, a cyano group, an amide group, an amino group, an alkyl group, an aryl group, an alkenyl group, and an alkynyl group. Group, hydroxy group, alkoxy group, aryloxy group, alkylsulfanyl group, arylsulfanyl group, alkylamino group, arylamino group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, alkylsulfonyl group, arylsulfonyl group, etc. It is done.

In the formula, m ₁ represents an integer of 0 to 4, p ₁ represents an integer of 0 or 1, and q ₁ represents an integer of ₁ to 4.

  The polymer compound having a polymerizable double bond group of the present invention may be a polymer comprising only a repeating unit having a phenyl group in which a vinyl group is substituted on the side chain and a repeating unit having a sulfonic acid group. As long as it does not interfere with the effects of the present invention, it may be a polymer into which another repeating unit is further introduced. Further, it may be a copolymer with another monomer, and such a monomer may be used alone or two or more of them may be used.

  Moreover, the high molecular compound which has a polymerizable double bond group of this invention can introduce | transduce arbitrary substituents into the terminal of a polymer principal chain by using a chain transfer agent. Specifically, linear alkane thiols, particularly linear alkane thiols substituted with silicon atoms bonded to alkoxy groups or halogen atoms, are preferably used because they can be used at the time of polymerization as a chain transfer agent. Can do. Examples of such chain transfer agents include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyldimethoxymethylsilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltrichlorosilane, 3-mercaptopropyldichloromethylsilane, 4 -Mercaptobutyltrimethoxysilane, 4-mercaptobutyldimethoxymethylsilane, 4-mercaptobutyltriethoxysilane, 4-mercaptobutyltrichlorosilane, 4-mercaptobutyldichloromethylsilane, and the like. May be bonded via an oxygen atom by hydrolytic condensation to form a siloxane bond.

  Preferred examples of the polymer compound having a polymerizable double bond group of the present invention are shown below, but the present invention is not limited to these examples. The numbers in the exemplified structural formulas represent the mass% of each repeating unit in the copolymer total composition of 100 mass%.

  The weight average molecular weight of the polymer compound having a polymerizable double bond group of the present invention is preferably in the range of 1,000 to 1,000,000, and more preferably in the range of 50,000 to 600,000. In the present invention, the polymer compound having a polymerizable double bond group may be used alone or in combination of two or more.

  Next, the low molecular weight compound having a polymerizable double bond group used in the present invention will be described. The low molecular compound having a polymerizable double bond group in this case can be preferably used as long as it is a compound that undergoes polymerization by radicals generated by the photodecomposition of the photopolymerizable initiator. Furthermore, when a compound having two or more polymerizable double bond groups in the molecule is used, a cross-linked product is formed as a result of polymerization by radicals, so that a photosensitive lithographic printing plate material was constituted. In some cases, since a crosslinked hard image part film is formed, a printing plate having excellent printing durability and ink transferability can be obtained, which can be used very preferably. Examples of compounds having a polymerizable double bond group that can be used for such purposes include 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, and tetraethylene glycol diacrylate. Polyfunctional acrylic monomers such as trisacryloyloxyethyl isocyanurate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, etc., or acryloyl group, methacryloyl group Polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, etc. are also used in the same way as various oligomers introduced with That.

  The photosensitive layer of the photosensitive lithographic printing plate of the present invention preferably contains a compound for sensitizing the above-mentioned photopolymerization initiator. As compounds that increase the sensitivity in the wavelength region of 400 to 430 nm, cyanine dyes, coumarin compounds described in JP-A-7-271284, JP-A-8-29973, etc., JP-A-9-230913, Carbazole compounds described in JP-A-2001-42524 and the like, carbomerocyanine dyes described in JP-A-8-262715, JP-A-8-272096, JP-A-9-328505, and the like. It is described in Kaihei 4-194857, JP-A-6-295061, JP-A-7-84863, JP-A-8-220755, JP-A-9-80750, JP-A-9-236913, etc. Aminobenzylidene ketone dyes, JP-A-4-184344, JP-A-6-301208, The pyromethine dyes described in Kaihei 7-225474, JP-A-7-5585, JP-A-7-281434, JP-A-8-6245, etc., and JP-A-9-80751 Styryl dyes or (thio) pyrylium compounds. Of these, cyanine dyes, coumarin compounds or (thio) pyrylium compounds are preferred.

  As other elements constituting the photosensitive layer of the photosensitive lithographic printing plate of the present invention, various colorants are preferably added for the purpose of improving visibility. As the pigment, carbon black, phthalocyanine blue, phthalocyanine green and the like are easily available and can be used.

  The photosensitive layer of the photosensitive lithographic printing plate of the present invention preferably contains a silane coupling agent. The photosensitive layer contains a silane coupling agent, so that excellent printing durability can be obtained. In the photosensitive lithographic printing plate having the hydrophilic layer of the present invention, printing durability is not deteriorated without reducing the tangling resistance. Is particularly preferable.

  The silane coupling agent is not particularly limited as long as the purpose is achieved, and any silane coupling agent can be used. For example, epoxycyclohexylethyltrimethoxysilane, glycidoxypropyltrimethoxysilane, acryloxypropyltrimethoxysilane, methacryloxypropyltrimethoxysilane, mercaptopropyltrimethoxysilane, mercaptopropyltriethoxysilane, methyltrimethoxysilane, dimethyldimethoxy Silane, phenyltrimethoxysilane, diphenyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, styryltrimethoxysilane, styryltriethoxysilane, hexyltrimethoxysilane, decyltrimethoxysilane , Vinyltris (3-methoxyethoxy) silane, vinyltriethoxysilane, vinyltrimeth Sisilane, 3-methacryloyloxypropyltrimethoxysilane, 3-acryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyl Trimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, N-β (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β (aminoethyl) -amino Propylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-chloropropyltrimethoxysilane 3-isocyanatopropyltriethoxysilane and the like. Among them, epoxycyclohexylethyltrimethoxysilane, glycidoxypropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, acryloxypropyltrimethoxysilane, methacryloxypropyltrimethoxysilane, mercaptopropyltrimethoxysilane, mercaptopropyltri Particularly preferred are trialkoxysilanes such as ethoxysilane. In addition, a silane coupling agent may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

  The amount of the silane coupling agent contained in the photosensitive layer is preferably in the range of 0.2 to 20% by mass, more preferably 0.5%, based on the compound having a polymerizable double bond group contained in the photosensitive layer. It is the range of -10 mass%.

  As another element constituting the photosensitive layer, a polymerization inhibitor is preferably added in order to prevent a curing reaction in a dark place due to thermal polymerization, for long-term storage. Polymerization inhibitors preferably used for such purposes include hydroquinones, catechols, naphthols, cresols and other compounds having various phenolic hydroxyl groups, quinone compounds, 2,2,6,6-tetramethylpiperidine- N-oxyls, N-nitrosophenylhydroxylamine salts and the like are preferably used. In this case, the polymerization inhibitor is preferably added in an amount of 0.01 to 10 parts by mass with respect to 100 parts by mass of the total solid content of the photosensitive layer of the photosensitive lithographic printing plate of the present invention.

  With respect to the dry solid content coating amount of the photosensitive layer itself, it is preferably formed with a dry solid content coating amount of 0.3 g or more per square meter by dry mass, and more preferably 2.0 g or more per square meter. When it is 2.0 g or more, it is preferable from the viewpoints of printing durability and ink transportability of minute images, but on the other hand, the tangling property when lithographic printing is performed by repeating printing and stopping tends to decrease. The present invention works particularly effectively in such systems. In addition, it is preferable that the upper limit of dry solid content application amount is 10 g or less per square meter.

<Protective layer>
In the photosensitive lithographic printing plate of the present invention, a protective layer is preferably further provided on the photosensitive layer. The protective layer prevents exposure of low molecular weight compounds such as oxygen and basic substances present in the atmosphere that hinder the image formation reaction caused by exposure in the photosensitive layer to further improve exposure sensitivity in the atmosphere. It has a favorable effect of improving. Furthermore, an effect of preventing the photosensitive layer surface from scratches is also expected. Therefore, the properties desired for such a protective layer are low permeability of low molecular weight compounds such as oxygen and excellent mechanical strength, and further, light transmission used for exposure is not substantially inhibited, and a photopolymerizable photosensitive layer. It is desirable that it is excellent in adhesion to the surface and can be easily removed in the development step after exposure.

  Such a device relating to the protective layer has been conventionally devised, and is described in detail in US Pat. No. 3,458,311 and JP-A-55-49729. As a material that can be used for the protective layer, for example, a water-soluble polymer compound having relatively excellent crystallinity is preferably used. Specifically, polyvinyl alcohol, polyvinyl pyrrolidone, acidic celluloses, gelatin, gum arabic, and polyacrylic are used. Water-soluble polymers such as acids are known, and among these, using polyvinyl alcohol as a main component gives the best results in terms of basic properties such as oxygen barrier properties and development removability. The polyvinyl alcohol used for the protective layer may be partially substituted with an ester, an ether and an acetal as long as it contains an unsubstituted vinyl alcohol unit for having necessary oxygen barrier properties and water solubility. Similarly, some of them may have other copolymer components. There is a preferred range for the coating amount of dry solids when applying such a protective layer, and it is preferable to form a dry solids coating amount in the range of 0.1 to 10 g per square meter on the photosensitive layer. Furthermore, the range of 0.3-3g is preferable. The protective layer is coated and dried on the photosensitive layer using various known coating methods.

  In the case of applying the hydrophilic layer of the photosensitive lithographic printing plate of the present invention, the photopolymerizable photosensitive layer provided thereon, and the protective layer, a composition comprising the above-described elements on the support. It is produced by applying and drying a coating liquid of a product. As the coating method, various known methods can be used, and examples thereof include bar coater coating, slide hopper coating coating, curtain coating, blade coating, air knife coating, roll coating, spin coating, and dip coating. it can.

<Development processing>
The developer used in the development processing may contain a surfactant or an alkali agent as necessary for the purpose of improving the image quality and shortening the development time. When the compound having a polymerizable double bond group has an acidic group such as a carboxyl group or a sulfonic acid group, and the acidic group is in the form of a metal salt or an ammonium salt in the photosensitive layer, It is possible to develop with a developer substantially not containing an alkali agent described later, that is, with a neutral developer having a pH of less than 9. In particular, when the compound having a polymerizable double bond group has a neutralized salt of a sulfonic acid group, good developability can be obtained, and elution with pure water or ion-exchanged water is possible. In the case of a neutralized salt or when sufficient solubility cannot be obtained even with a sulfonic acid group neutralized salt, an activator may be added to the neutral developer for the purpose of improving developability. it can.

  Nonionic properties such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl aryl ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, monoglyceride alkyl esters as surfactants, alkylbenzene sulfonates, alkylnaphthalene sulfonic acids Anionic surfactants such as salts, alkyl sulfates, alkyl sulfonates, sulfosuccinate esters, amphoteric surfactants such as alkyl betaines, amino acids, isopropyl alcohol, benzyl alcohol, ethyl cellosolve, butyl cellosolve, phenyl cellosolve, propylene glycol And water-soluble organic solvents such as diacetone alcohol.

  On the other hand, when the compound having a polymerizable double bond group has an unneutralized acidic group such as a carboxyl group or a sulfonic acid group, the developer preferably contains an alkali agent. Alkaline agents include sodium silicate, potassium silicate, lithium silicate, ammonium silicate, sodium metasilicate, potassium metasilicate, sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, diphosphoric acid Inorganic alkali salts such as sodium, sodium triphosphate, dibasic ammonium phosphate, tribasic ammonium phosphate, sodium borate, potassium borate, ammonium borate, or monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine , Diisopropylamine, monobutylamine, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, etc. Is, they were added, can be used as an alkaline developing solution by adjusting to pH9 above. In addition, it is preferable to add the activator or the like used as the neutral developer to the alkali developer to improve the developability.

  The development is usually carried out by a known development method such as immersion development, spray development, brush development, ultrasonic development, etc., preferably at a temperature of about 10 to 60 ° C., more preferably about 15 to 45 ° C. for 5 seconds to It takes about 10 minutes. At that time, the protective layer provided as necessary on the photosensitive layer may be removed in advance with water or the like, or may be removed during development.

  EXAMPLES Hereinafter, although this invention is demonstrated using an Example, this invention is not limited by this description. In the following description, “%” and “part” are based on mass unless otherwise specified.

Example 1
<Preparation of photosensitive lithographic printing plate 1>
A hydrophilic layer coating solution 1 having the following composition was applied on a polyethylene terephthalate film having a thickness of about 200 μm by a slide hopper coating method. At that time, the moisture application amount was set in advance to be 35 g / m ² . Immediately after coating, the coating film was gelled with cold air of 1 to 5 ° C., and then dried using a dry air set at 50 ° C. After drying, a hydrophilic layer was formed on the polyethylene terephthalate film by placing it in a thermo-hygrostat adjusted to 40 ° C. and 40% RH for 7 days.

<Hydrophilic layer coating solution 1>
Alkali-treated gelatin 1.3 parts Inorganic filler 1: Titanium dioxide 4.0 parts (TISR1, manufactured by Sakai Chemical Industry Co., Ltd., average primary particle diameter≈0.3 μm, relative refractive index≈2.04)
Inorganic filler 2: 1.6 parts of barium sulfate (B35, manufactured by Sakai Chemical Industry Co., Ltd., average primary particle size≈0.3 μm, relative refractive index≈1.23)
Inorganic filler 3: 0.4 parts of aluminum hydroxide (H42, manufactured by Showa Denko KK, average primary particle size ≈ 1.0 μm, relative refractive index ≈ 1.24)
Dispersant (acrylic acid copolymerized metal salt, 10% solution) 1.0 part polyoxyethylene alkyl ether: NIKKOL BT-9 10% solution (manufactured by Nikko Chemicals Co., Ltd., carbon number 12-14 of R, ethylene oxide Addition mole number n = 9) 0.4 part Hardener (divinyl sulfone, 5% solution) 4.0 parts The total amount was 35 parts by mass with water.

  Regarding the particle size distribution and distribution frequency of the inorganic filler contained in the hydrophilic layer coating liquid 1, the inorganic fillers 2 and 3 contained in the hydrophilic layer coating liquid 1 are not added, but in the hydrophilic layer coating liquid. In addition, an inorganic filler 1 alone is prepared, and a coating liquid in which the inorganic fillers 2 and 3 are present alone in the hydrophilic layer coating liquid is prepared in the same manner. The particle size distribution and distribution frequency of the filler were measured using a laser diffraction / scattering type particle size distribution measuring apparatus (LA920 manufactured by Horiba, Ltd.), and the particle size distribution of each obtained single dispersion was multiplied by the addition ratio as a coefficient. The particle size distribution and distribution frequency of the hydrophilic layer coating solution 1 described above were calculated. As a result, the distribution frequency fx of the inorganic filler existing in the range of 0.2 μm or more and less than 0.6 μm is 64.8%, and the distribution frequency fy of the inorganic filler existing in the range of 0.6 μm or more and less than 1.5 μm is It was 30.1% and fx / fy was 2.15.

On the hydrophilic layer obtained as described above, the following photopolymerizable photosensitive layer coating solution was applied so that the solid content was 2.6 g / m ^2, and after application, in a 75 ° C. drier. Dried for 10 minutes.

<Photopolymerizable photosensitive layer coating solution>
Sulfonic acid type polymer SP-2 (weight average molecular weight 400,000) 1.0 part Pentaerythritol tetraacrylate 1.5 part 3-acryloxypropyltrimethoxysilane 0.08 part Photopolymerization initiator BC-6 0.1 part Photopolymerization initiator T-8 0.1 part Sensitizer Following structure 0.05 part Colorant Pigment Blue 15 0.2 part Acetone 5.0 part Ethanol 5.0 part Tetrahydrofuran 10.0 part

<Protective layer>
A coating solution is prepared according to the following protective layer formulation, coated on the photopolymerizable photosensitive layer so that the solid content is 1.5 g / m ^2, and dried for 10 minutes in a 75 ° C. drier after coating. Thus, a photosensitive lithographic printing plate 1 was obtained.

<Protective layer prescription>
Polyvinyl alcohol PVA-102 (manufactured by Kuraray Co., Ltd.) 1.0 part Ion exchange water 9.0 parts

<Preparation of photosensitive lithographic printing plate 2>
In the preparation of the photosensitive lithographic printing plate 1 described above, polyoxyethylene alkyl ether used for preparation of the hydrophilic layer coating solution 1: Nikko Chemicals Co., Ltd., instead of a 10% solution of NIKKOL BT-9, Polyoxyethylene alkyl ether: manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neugen ET-135 (R 12 to 14 carbon atoms, ethylene oxide addition mole number n = 7) using a 10% solution of hydrophilic layer A photosensitive lithographic printing plate 2 was obtained in the same manner as in the preparation of the photosensitive lithographic printing plate 1 except that was formed.

<Preparation of photosensitive lithographic printing plate 3>
In the preparation of the photosensitive lithographic printing plate 1 described above, polyoxyethylene alkyl ether used for preparation of the hydrophilic layer coating solution 1: Nikko Chemicals Co., Ltd., instead of a 10% solution of NIKKOL BT-9, Polyoxyethylene alkyl ether: manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neugen ET-165 (carbon number of R 12-12, number of added moles of ethylene oxide n = 12) 10% solution using hydrophilic layer A photosensitive lithographic printing plate 3 was obtained in the same manner as in the preparation of the photosensitive lithographic printing plate 1 except that was formed.

<Preparation of photosensitive lithographic printing plate 4>
In the preparation of the photosensitive lithographic printing plate 1 described above, polyoxyethylene alkyl ether used for preparation of the hydrophilic layer coating solution 1: Nikko Chemicals Co., Ltd., instead of a 10% solution of NIKKOL BT-9, Polyoxyethylene alkyl ether: manufactured by Daiichi Kogyo Seiyaku Co., Ltd., DKS NL-70 (R 12 carbon atoms, ethylene oxide addition mole number n = 7) was used to form a hydrophilic layer. Except for the above, a photosensitive lithographic printing plate 4 was obtained in the same manner as in the preparation of the photosensitive lithographic printing plate 1.

<Preparation of photosensitive lithographic printing plate 5>
In the preparation of the photosensitive lithographic printing plate 1 described above, polyoxyethylene alkyl ether used for preparation of the hydrophilic layer coating solution 1: Nikko Chemicals Co., Ltd., instead of a 10% solution of NIKKOL BT-9, Polyoxyethylene alkyl ether: manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neugen TDS-80 (carbon number of R = 13, number of added moles of ethylene oxide n = 8) was used to form a hydrophilic layer. Except for the above, a photosensitive lithographic printing plate 5 was obtained in the same manner as in the preparation of the photosensitive lithographic printing plate 1.

<Preparation of photosensitive lithographic printing plate 6>
In the preparation of the photosensitive lithographic printing plate 1 described above, polyoxyethylene alkyl ether used for preparation of the hydrophilic layer coating solution 1: Nikko Chemicals Co., Ltd., instead of a 10% solution of NIKKOL BT-9, Linear alkylbenzene sulfonate: manufactured by Daiichi Kogyo Seiyaku Co., Ltd., except that a hydrophilic layer was formed using a 10% solution of Neogen SC-F. A photosensitive lithographic printing plate 6 was obtained.

<Preparation of photosensitive lithographic printing plate 7>
In the preparation of the photosensitive lithographic printing plate 1 described above, polyoxyethylene alkyl ether used for preparation of the hydrophilic layer coating solution 1: Nikko Chemicals Co., Ltd., instead of a 10% solution of NIKKOL BT-9, Sodium dialkylsulfosuccinate: Photosensitive lithographic printing plate in the same manner as in the preparation of photosensitive lithographic printing plate 1, except that a hydrophilic layer was formed using a 10% solution of Perex OT-P manufactured by Kao Corporation 7 was obtained.

<Preparation of photosensitive lithographic printing plate 8>
In the preparation of the photosensitive lithographic printing plate 1 described above, polyoxyethylene alkyl ether used for preparation of the hydrophilic layer coating solution 1: Nikko Chemicals Co., Ltd., instead of a 10% solution of NIKKOL BT-9, Polyoxyethylene alkylamine: manufactured by Daiichi Kogyo Seiyaku Co., Ltd. Photosensitive lithographic printing plate 1 except that a hydrophilic layer was formed using a 10% solution of amylatin D. A lithographic printing plate 8 was obtained.

<Preparation of photosensitive lithographic printing plate 9>
In the preparation of the photosensitive lithographic printing plate 1 described above, polyoxyethylene alkyl ether used for preparation of the hydrophilic layer coating solution 1: Nikko Chemicals Co., Ltd., instead of a 10% solution of NIKKOL BT-9, Polyoxyethylene naphthyl ether: manufactured by Daiichi Kogyo Seiyaku Co., Ltd., a 10% solution of Neugen EN-10 was used to form a hydrophilic layer in the same manner as in preparation of photosensitive lithographic printing plate 1, except that A sex lithographic printing plate 9 was obtained.

<Preparation of photosensitive lithographic printing plate 10>
In the preparation of the photosensitive lithographic printing plate 1 described above, polyoxyethylene alkyl ether used for preparation of the hydrophilic layer coating solution 1: Nikko Chemicals Co., Ltd., instead of a 10% solution of NIKKOL BT-9, Polyoxyethylene phenyl ether: Photosensitive lithographic plate as in the preparation of photosensitive lithographic printing plate 1 except that a hydrophilic layer was formed using a 10% solution of PHE-1 manufactured by Daiichi Kogyo Seiyaku Co., Ltd. A printing plate 10 was obtained.

<Preparation of photosensitive lithographic printing plate 11>
In the preparation of the photosensitive lithographic printing plate 1 described above, polyoxyethylene alkyl ether used for preparation of the hydrophilic layer coating solution 1: Nikko Chemicals Co., Ltd., instead of a 10% solution of NIKKOL BT-9, Polyoxyethylene lauryl ether sodium acetate: The same as the preparation of the photosensitive lithographic printing plate 1, except that a hydrophilic layer was formed using a 10% solution of Neo Haitenol ECL-45 manufactured by Daiichi Kogyo Seiyaku Co., Ltd. Thus, a photosensitive lithographic printing plate 11 was obtained.

<Preparation of photosensitive lithographic printing plate 12>
In the preparation of the photosensitive lithographic printing plate 1 described above, polyoxyethylene alkyl ether used for preparation of the hydrophilic layer coating solution 1: Nikko Chemicals Co., Ltd., instead of a 10% solution of NIKKOL BT-9, Sodium polyoxyethylene nonylphenyl ether sulfate: The same as the preparation of the photosensitive lithographic printing plate 1 except that a hydrophilic layer was formed using a 10% solution of Taipol NPS-436 manufactured by Taiko Oil and Fat Chemical Co., Ltd. Thus, a photosensitive lithographic printing plate 12 was obtained.

<Exposure / Development>
About the photosensitive lithographic printing plates 1 to 12 obtained above, a test chart image was exposed using a blue-violet semiconductor laser emitting at 405 nm (output 60 mW) as an exposure light source and setting the plate surface exposure energy to 200 μJ / cm ² . . Thereafter, the plate was immersed in ion exchange water at 25 ° C. for 15 seconds, and the surface having the photopolymerizable photosensitive layer / protective layer was rubbed and developed with cellulose sponge, and then dried to prepare a printing plate. Using this printing press plate, the resistance to entanglement was evaluated by the following method.

<Print durability>
The printing machine uses an offset sheet-fed press Heidelberg QM46, the printing ink is New Champion F gloss ink H manufactured by DIC Corporation, and the dampening liquid is 1% of Astro Mark III manufactured by Nikken Chemical Laboratory. Printing was performed using the diluent. In the plate finishing, a gauge film was used, and the standard 200 μm was set to 300 μm (+100 μm). As an evaluation, the printing paper surface at the start and the printing paper surface at the time of printing 10,000 sheets are compared, and the attenuation factor of the highlight halftone dot portion and the fine defect in the solid portion are 25 times magnifier. Careful observation and judgment were made using the following evaluation criteria. The results are shown in Table 1.

A: Almost no change is observed in the highlight part and the solid part.
○: Slight attenuation (within an attenuation rate of 10% or less) is observed in the highlight portion. However, no defects are observed in the solid part.
Δ: A clear attenuation (attenuation rate of 10% or more) is observed in the highlight portion. However, no defects are observed in the solid part.
X: The highlight part is attenuated by 50% or more, or an abnormality such as a defect is observed in the solid part.

<Reticulation resistance>
The printing machine uses an offset sheet-fed press Heidelberg QM46, the printing ink is Toyo Ink Co., Ltd.'s High Unity Neo Soy Red LZ, and the dampening liquid is Nitro Chemical Laboratory Co., Ltd. Astro Mark III. 500 sheets of printing (printing 1) was performed using a 1% diluted solution. After that, the printing press is temporarily stopped, only the blanket is washed, and the printing is performed 500 sheets (printing 2) by starting the paper feeding after touching the water foam roller 5 times or more again as usual. After the machine was stopped for 30 minutes (stop 1), 500 sheets were printed again. Thus, after repeating the operation | work of printing 2-stop 1 5 times for convenience, the printed printing paper surface was observed and it determined using the following evaluation criteria. The results are shown in Table 1.

A: No entanglement is observed even in shadows of 90% or more,
And there is no problem in reproducibility.
○: Slight entanglement is observed at halftone dots of 85% or more and less than 90%,
There is no problem in practical use.
(Triangle | delta): A tangle is recognized by the halftone dot part of 70% or more and less than 85%.
X: Tangle is observed at a halftone dot portion of less than 70%, and a problem is observed in reproducibility.

  As can be seen from Table 1, it can be seen that sufficient reticulation resistance can be obtained even when lithographic printing is performed by repeating printing and stopping without lowering printing durability according to the present invention.

Claims (1)

  Photosensitivity having at least a hydrophilic layer containing a hydrophilic binder, an inorganic filler, and a polyoxyethylene alkyl ether on a support, and a photopolymerizable photosensitive layer containing a trihaloalkyl-substituted compound on the hydrophilic layer. Lithographic printing plate.