JP5466621B2 - Resin composition for laser engraving, relief printing plate precursor for laser engraving, plate making method of relief printing plate and relief printing plate - Google Patents

Description

  The present invention relates to a resin composition for laser engraving, a relief printing plate precursor for laser engraving, a method for making a relief printing plate, and a relief printing plate.

Many so-called “direct engraving CTP methods” have been proposed in which a relief forming layer is directly engraved with a laser to make a plate. In this method, the flexographic original plate is directly irradiated with a laser, and thermal decomposition and volatilization are caused by photothermal conversion to form a recess. Unlike the relief formation using the original film, the direct engraving CTP method can freely control the relief shape. For this reason, when an image such as a letter is formed, the area is engraved deeper than other areas, or the fine halftone dot image is engraved with a shoulder in consideration of resistance to printing pressure. Is also possible. In general, a high-power carbon dioxide laser is used as a laser for this method. In the case of a carbon dioxide laser, all organic compounds can absorb irradiation energy and convert it into heat. On the other hand, inexpensive and small-sized semiconductor lasers have been developed. However, since these are visible and near infrared light, it is necessary to absorb the laser light and convert it into heat.
For example, Patent Document 1 is known as a conventional resin composition for laser engraving.

International Publication No. 2010/090345

  The problem to be solved by the present invention is a resin composition for laser engraving, which is excellent in the stability of the composition, can obtain a relief printing plate excellent in printing durability, and has excellent rinsing properties after laser engraving, the laser It is to provide a relief printing plate precursor using a resin composition for engraving, a plate making method of a relief printing plate using the relief printing plate precursor, and a relief printing plate obtained by the plate making method.

The above-described problems of the present invention have been solved by the following means <1>, <10>, <13> and <14>. They are listed together with <2> to <9>, <11>, <12>, <15> and <16> which are preferred embodiments.
<1> For laser engraving, comprising (Component A) a compound having a hydrolyzable silyl group and / or silanol group, (Component B) a thermal base generator, and (Component C) a binder polymer. Resin composition,
<2> The resin composition for laser engraving according to <1>, wherein the component A is a compound having a total of two or more hydrolyzable silyl groups and / or silanol groups,
<3> The resin composition for laser engraving according to <1> or <2>, wherein the hydrolyzable silyl group in Component A is a residue in which at least one alkoxy group or halogen atom is directly bonded to an Si atom. ,
<4> The resin composition for laser engraving according to any one of the above <1> to <3>, wherein Component B is a salt of a base and an acid,
<5> The resin composition for laser engraving according to <5>, wherein the base is an amine compound,
<6> The resin composition for laser engraving according to <5>, wherein the amine compound is a cycloamidine compound,
<7> The resin composition for laser engraving according to <6>, wherein the cycloamidine compound is a compound represented by the formula (1):

（ｍは２〜６の整数を表し、Ｒはそれぞれ独立に、水素原子又は置換基を表す。）

(M represents an integer of 2 to 6, and each R independently represents a hydrogen atom or a substituent.)

<8> The compound represented by the formula (1) is 1,8-diazabicyclo [5.4.0] undecene-7 or 1,5-diazabicyclo [4.3.0] nonene-5. , The resin composition for laser engraving according to <7> above,
<9> The resin composition for laser engraving according to any one of the above <4> to <8>, wherein the acid is an organic acid.
<10> The resin composition for laser engraving according to <9>, wherein the organic acid is an organic acid selected from the group consisting of a carboxylic acid, an aromatic hydroxy compound, and an organic sulfonic acid,
<11> The resin composition for laser engraving according to any one of the above <1> to <10>, wherein Component C is at least one selected from the group consisting of an acrylic resin and polyvinyl butyral,
<12> The resin composition for laser engraving according to <11>, wherein the component C is polyvinyl butyral,
<13> (Component D) The resin composition for laser engraving according to any one of the above <1> to <12>, further comprising a polymerizable compound,
<14> (Component E) The resin composition for laser engraving according to any one of the above <1> to <13>, further comprising a polymerization initiator,
<15> (Component F) The resin composition for laser engraving according to any one of the above <1> to <14>, further comprising a photothermal conversion agent capable of absorbing light having a wavelength of 700 to 1,300 nm,
A relief printing plate precursor for laser engraving comprising a relief forming layer formed from the resin composition for laser engraving according to any one of the above <1> to <15> on a <16> support,
<17> For laser engraving having a crosslinked relief forming layer obtained by thermally crosslinking a relief forming layer formed from the resin composition for laser engraving according to any one of <1> to <15> above on a support. Relief printing plate precursor,
<18> A method for making a relief printing plate comprising a step of forming a relief layer by laser engraving a crosslinked relief forming layer in the relief printing plate precursor as described in <17> above,
<19> A relief printing plate having a relief layer produced by the plate making method described in <18> above,
<20> The relief printing plate according to <19>, wherein the relief layer has a thickness of 0.05 mm to 10 mm.
<21> The relief printing plate according to <19> or <20>, wherein the Shore A hardness of the relief layer is from 50 ° to 90 °.

  According to the resin composition for laser engraving of the present invention, a relief printing plate excellent in stability of the composition and excellent in printing durability can be obtained, and the resin composition for laser engraving excellent in rinsing properties after laser engraving. , A relief printing plate precursor using the resin composition for laser engraving, a plate making method of a relief printing plate using the relief printing plate precursor, and a relief printing plate obtained by the plate making method could be provided. .

(Resin composition for laser engraving)
The resin composition for laser engraving of the present invention (hereinafter also simply referred to as “resin composition”) comprises (Component A) a compound having a hydrolyzable silyl group and / or silanol group, and (Component B) generation of a thermal base. And (Component C) a binder polymer.
In the present invention, the description of “lower limit to upper limit” representing a numerical range represents “lower limit or higher and lower limit or lower”, and the description of “upper limit to lower limit” represents “lower limit or higher and lower limit or higher”. That is, it represents a numerical range including an upper limit and a lower limit. In the present invention, “(Component A) a compound having a hydrolyzable silyl group and / or silanol group” or the like is also simply referred to as “Component A” or the like.

The resin composition for laser engraving of the present invention is not particularly limited other than the relief forming layer application of the relief printing plate precursor subjected to laser engraving, and can be widely applied to other applications. For example, not only the relief forming layer of the printing plate precursor that forms the convex relief described in detail below by laser engraving, but also other material shapes that form irregularities and openings on the surface, such as intaglio, stencil, stamp, etc. The present invention can be applied to the formation of various printing plates and various molded articles on which images are formed by laser engraving.
Especially, it is a preferable aspect to apply to formation of the relief forming layer provided on a suitable support body.

In the present specification, regarding the description of the relief printing plate precursor, the component A to component C are contained, and the surface is a flat layer as an image forming layer to be subjected to laser engraving and is an uncrosslinked crosslinkable layer Is referred to as a relief forming layer, a layer obtained by crosslinking the relief forming layer is referred to as a crosslinked relief forming layer, and a layer in which irregularities are formed on the surface by laser engraving is referred to as a relief layer.
Hereinafter, the components of the resin composition for laser engraving will be described.

(Component A) Compound having hydrolyzable silyl group and / or silanol group The resin composition for laser engraving of the present invention comprises (Component A) a compound having a hydrolyzable silyl group and / or silanol group.
The “hydrolyzable silyl group” in Component A used in the resin composition for laser engraving of the present invention is a silyl group having a hydrolyzable group. Examples of the hydrolyzable group include an alkoxy group, an aryloxy group Groups, mercapto groups, halogeno groups, amide groups, acetoxy groups, amino groups, isopropenoxy groups and the like. The silyl group is hydrolyzed to become a silanol group, and the silanol group is dehydrated and condensed to form a siloxane bond. Such a hydrolyzable silyl group or silanol group is preferably represented by the following formula (1).

In the formula (1), R ^{1 to} R ³ are each independently selected from the group consisting of an alkoxy group, an aryloxy group, a mercapto group, a halogen atom, an amide group, an acetoxy group, an amino group, and an isopropenoxy group. A hydrolyzable group, a hydroxyl group, a hydrogen atom, or a monovalent organic group is represented. However, at least one of R ^{1 to} R ³ is a hydrolysis selected from the group consisting of an alkoxy group, an aryloxy group, a mercapto group, a halogen atom, an amide group, an acetoxy group, an amino group, and an isopropenoxy group. Represents a sex group or a hydroxyl group. Moreover, a wavy line part represents a coupling position with another structure.
A preferable organic group in the case where R ^{1 to} R ³ represent a monovalent organic group includes an alkyl group having 1 to 30 carbon atoms from the viewpoint of imparting solubility in various organic solvents.
In the formula (1), the hydrolyzable group bonded to the silicon atom is particularly preferably an alkoxy group or a halogen atom.
As an alkoxy group, a C1-C30 alkoxy group is preferable from a viewpoint of rinse property and printing durability, A C1-C15 alkoxy group is more preferable, A C1-C5 alkoxy group is still more preferable, Carbon A C 1-3 alkoxy group is particularly preferred.
Examples of the halogen atom include F atom, Cl atom, Br atom, and I atom. From the viewpoint of ease of synthesis and stability, Cl atom and Br atom are preferable, and Cl atom is more preferable.

Component A is preferably a compound having at least one group represented by the formula (1), and more preferably a compound having at least two groups represented by the formula (1). . Component A is particularly preferably a compound having at least two hydrolyzable silyl groups.
As component A, a compound having two or more silicon atoms in the molecule is preferably used. The number of silicon atoms contained in the compound is preferably 2 or more and 6 or less, and most preferably 2 or 3.
The hydrolyzable group can be bonded to one silicon atom in the range of 1 to 3, and the total number of hydrolyzable groups in the formula (1) is preferably in the range of 2 or 3. It is particularly preferred that three hydrolyzable groups are bonded to the silicon atom. When two or more hydrolyzable groups are bonded to a silicon atom, they may be the same as or different from each other.

Specific examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a tert-butoxy group, and a benzyloxy group. Examples of the alkoxysilyl group to which the alkoxy group is bonded include trialkoxysilyl groups such as trimethoxysilyl group, triethoxysilyl group and triisopropoxysilyl group; dimethoxysilyl groups such as dimethoxymethylsilyl group and diethoxymethylsilyl group A monoalkoxysilyl group such as a methoxydimethylsilyl group and an ethoxydimethylsilyl group; A plurality of these alkoxy groups may be used in combination, or a plurality of different alkoxy groups may be used in combination.
Specific examples of the aryloxy group include a phenoxy group. Examples of the aryloxysilyl group to which the aryloxy group is bonded include a triaryloxysilyl group such as a triphenoxysilyl group.

Preferable examples of component A in the present invention include compounds in which a plurality of groups represented by the formula (1) are bonded through a linking group. A linking group comprising a sulfide group, an imino group or a ureylene group is preferred.
A typical method for synthesizing Component A containing a linking group having a sulfide group, imino group or ureylene group is shown below.

(Method for synthesizing a compound having a hydrolyzable silyl group and / or a silanol group having a linking group containing a sulfide group)
The method for synthesizing component A having a linking group containing a sulfide group (hereinafter also referred to as “sulfide linking group-containing component A” as appropriate) is not particularly limited, but specifically, for example, a component having a halogenated hydrocarbon group. Reaction of A with alkali sulfide, reaction of component A having a mercapto group with a halogenated hydrocarbon, reaction of component A having a mercapto group with component A having a halogenated hydrocarbon group, component A having a halogenated hydrocarbon group Reaction of mercaptans, reaction of component A having an ethylenically unsaturated double bond with mercaptans, reaction of component A having an ethylenically unsaturated double bond and component A having a mercapto group, ethylenically unsaturated double bond Reaction of a compound having a mercapto group with a compound A, reaction of a ketone with a component A having a mercapto group, having a diazonium salt and a mercapto group Reaction of component A having a mercapto group and an oxirane, reaction of component A having a mercapto group and component A having an oxirane group, reaction of a mercaptan and component A having an oxirane group, and mercapto It is synthesized by any synthesis method selected from the reaction of component A having a group with aziridines and the like.

(Method for synthesizing a compound having at least one of a hydrolyzable silyl group having a linking group containing an imino group and a silanol group)
The method for synthesizing a compound having at least one of a hydrolyzable silyl group having a linking group containing an imino group and a silanol group (hereinafter also referred to as imino linking group-containing component A) is not particularly limited. Examples thereof include reaction of component A having an amino group with a halogenated hydrocarbon, reaction of component A having an amino group with component A having a halogenated hydrocarbon group, component A having a halogenated hydrocarbon group and amines Reaction of component A having amino group and oxirane, reaction of component A having amino group and component A having oxirane group, reaction of component A having amine group and oxirane group, component A having amino group Reaction with aziridines, reaction of component A having an ethylenically unsaturated double bond with amines, component A having an ethylenically unsaturated double bond and an amino group Reaction of component A, reaction of compound having ethylenically unsaturated double bond and component A having amino group, reaction of compound having acetylenic unsaturated triple bond and component A having amino group, imine unsaturated double bond Selected from reaction of component A having a bond with an organic alkali metal compound, reaction of component A having an imine unsaturated double bond and an organic alkaline earth metal compound, reaction of component A having a carbonyl compound and an amino group, etc. It is synthesized by any of the synthesis methods to be performed.

(Synthesis method of a compound having at least one of hydrolyzable silyl group and silanol group having a linking group containing a ureylene group)
A method for synthesizing a compound having at least one of a hydrolyzable silyl group having a linking group containing a ureylene group and a silanol group (hereinafter also referred to as a ureylene linking group-containing component A as appropriate) is not particularly limited. For example, reaction of component A having an amino group and isocyanate esters, reaction of component A having amino groups and component A having isocyanate ester, and reaction of component A having amines and isocyanate ester Or any other synthetic method selected from the above.

As component A in the present invention, a silane coupling agent is preferably used.
Hereinafter, a silane coupling agent suitable as Component A in the present invention will be described.
In the present invention, a functional group in which at least one alkoxy group or halogeno group is directly bonded to a Si atom is called a silane coupling group, and a compound having one or more silane coupling groups in the molecule is a silane coupling group. Also called a coupling agent. The silane coupling group is preferably a group in which two or more alkoxy groups or halogen atoms are directly bonded to the Si atom, and a group in which three or more are directly bonded is particularly preferable.
In the resin composition of the present invention, at least one of the hydrolyzable silyl group and silanol group in Component A, preferably the silane coupling group in the silane coupling agent is (Component C) a reactive functional group in the binder polymer. In the case of a group such as a hydroxyl group (—OH), an alcohol exchange reaction is caused with this hydroxyl group to form a crosslinked structure. As a result, the binder polymer molecules are three-dimensionally cross-linked through the silane coupling agent.
In the silane coupling agent which is a preferred embodiment in the present invention, it is essential to have at least one functional group of an alkoxy group and a halogen atom as the functional group directly bonded to the Si atom. From the viewpoint of ease, those having an alkoxy group are preferred.
Here, the alkoxy group is preferably an alkoxy group having 1 to 30 carbon atoms, more preferably an alkoxy group having 1 to 15 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms from the viewpoint of rinsing properties and printing durability. Directly preferred.
Examples of the halogen atom include an F atom, a Cl atom, a Br atom, and an I atom. From the viewpoint of ease of synthesis and stability, a Cl atom and a Br atom are preferable, and a Cl atom is more preferable.

The silane coupling agent in the present invention preferably contains 1 to 10 silane coupling groups in the molecule from the viewpoint of maintaining a good balance between the degree of crosslinking and flexibility of the film. More preferably, it is more preferably 2 or less, and particularly preferably 2 or more and 4 or less.
When there are two or more silane coupling groups, the silane coupling groups are preferably connected to each other by a linking group. Examples of the linking group include a divalent or higher valent organic group that may have a substituent such as a heteroatom or a hydrocarbon, and an embodiment containing a heteroatom (N, S, O) is preferable in terms of high engraving sensitivity. Particularly preferred are linking groups containing an S atom.
From such a viewpoint, the silane coupling agent in the present invention has, as an alkoxy group, a methoxy group or an ethoxy group, in particular, two silane coupling groups in which a methoxy group is bonded to an Si atom in the molecule, and these A compound in which the silane coupling group is bonded via an alkylene group containing a hetero atom (particularly preferably an S atom) is suitable. More specifically, those having a linking group containing a sulfide group are preferred.
Moreover, as another preferred embodiment of a linking group for connecting silane coupling groups, a linking group having an oxyalkylene group can be mentioned. When the linking group includes an oxyalkylene group, the rinse property of engraving residue after laser engraving is improved. As the oxyalkylene group, an oxyethylene group is preferable, and a polyoxyethylene chain in which a plurality of oxyethylene groups are linked is more preferable. The total number of oxyethylene groups in the polyoxyethylene chain is preferably 2 to 50, more preferably 3 to 30, and particularly preferably 4 to 15.

  Specific examples of the silane coupling agent that can be used in the present invention are shown below. Examples of the silane coupling agent in the present invention include β- (3,4 epoxy cyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and γ-glycine. Sidoxypropyltriethoxysilane, N- (β-aminoethyl) -γ-aminopropylmethyldimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, N- (β-aminoethyl)- γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxy Silane, bis (triethoxy Rylpropyl) disulfide, bis (triethoxysilylpropyl) tetrasulfide, 1,4-bis (triethoxysilyl) benzene, bis (triethoxysilyl) ethane, 1,6-bis (trimethoxysilyl) hexane, 1,8- Bis (triethoxysilyl) octane, 1,2-bis (trimethoxysilyl) decane, bis (triethoxysilylpropyl) amine, bis (trimethoxysilylpropyl) urea, γ-chloropropyltrimethoxysilane, γ-ureidopropyl Although triethoxysilane etc. can be mentioned, besides this, the compound shown by the following formula | equation is mentioned as a preferable thing, However, This invention is not restrict | limited to these compounds.

In the above formulas, R represents a partial structure selected from the following structures. When a plurality of R and R ¹ are present in the molecule, these may be the same or different from each other, and are preferably the same in terms of synthesis suitability. In the chemical formulas below, Et represents an ethyl group, and Me represents a methyl group.

In the above formulas, R represents a partial structure shown below. R ¹ has the same meaning as described above. When a plurality of R and R ¹ are present in the molecule, these may be the same or different from each other, and are preferably the same in terms of synthesis suitability.

  Component A can be obtained by appropriately synthesizing, but it is preferable from the viewpoint of cost to use a commercially available product. Examples of component A include commercially available silane products and silane coupling agents commercially available from Shin-Etsu Chemical Co., Ltd., Toray Dow Corning Co., Ltd., Momentive Performance Materials Co., Ltd., Chisso Co., Ltd., etc. Since the product corresponds to this, these commercially available products may be appropriately selected and used in the composition of the present invention according to the purpose.

  As the silane coupling agent in the present invention, in addition to the above compounds, a partial hydrolysis condensate obtained using one kind of silane, and a partial cohydrolysis condensate obtained using two or more kinds of silanes Can be used. Hereinafter, these compounds may be referred to as “partial (co) hydrolysis condensates”.

  Specific examples of such partial (co) hydrolysis condensates include tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, methyltriacetoxysilane, methyltris (methoxyethoxy). ) Silane, methyltris (methoxypropoxy) silane, ethyltrimethoxysilane, propyltrimethoxysilane, butyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, cyclohexyltrimethoxysilane, phenyltrimethoxysilane , Phenyltriethoxysilane, tolyltrimethoxysilane, chloromethyltrimethoxysilane, γ-chloropropyltrimethoxysilane, 3,3,3-trifluoropro Rutrimethoxysilane, cyanoethyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-aminopropyltrimethoxy Silane, γ-aminopropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, dimethyldimethoxysilane, dimethyl Diethoxysilane, diethyldimethoxysilane, methylethyldimethoxysilane, methylpropyldimethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, methylphenyldimethoxysilane, γ-chloro Propylmethyldimethoxysilane, 3,3,3-trifluoropropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-aminopropylmethyldiethoxysilane, N-β (aminoethyl) γ-aminopropylmethyl A portion obtained by using as a precursor one or more selected from silane compounds consisting of alkoxysilanes such as dimethoxysilane and γ-mercaptopropylmethyldiethoxysilane, or acyloxysilanes such as acetyloxysilane and etoxalyloxysilane (Co) hydrolysis condensates can be mentioned.

  Among these silane compounds as partial (co) hydrolysis condensate precursors, a substituent selected from a methyl group and a phenyl group as a substituent on silicon from the viewpoint of versatility, cost, and film compatibility More specifically, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldimethoxysilane are preferred. Ethoxysilane is exemplified as a preferred precursor.

  In this case, as a partial (co) hydrolysis condensate, dimers of the silane compound as described above (1 mol of water was allowed to act on 2 mol of the silane compound to remove 2 mol of alcohol to form disiloxane units. To 100-mer, preferably to dimer to 50-mer, more preferably to dimer to 30-mer, and more preferably to a part (co-polymer) using two or more silane compounds as raw materials. It is also possible to use hydrolysis condensates.

  Such a partial (co) hydrolyzed condensate may be a commercially available silicone alkoxy oligomer (for example, commercially available from Shin-Etsu Chemical Co., Ltd.). Based on the method, after making less than equivalent hydrolysis water react with a hydrolysable silane compound, you may use what was manufactured by removing by-products, such as alcohol and hydrochloric acid. In production, for example, when using alkoxysilanes or acyloxysilanes as described above as the precursor hydrolyzable silane compound, acids such as hydrochloric acid and sulfuric acid, sodium hydroxide, hydroxide Alkaline or alkaline earth metal hydroxides such as potassium, alkaline organic substances such as triethylamine, etc. may be used as a reaction catalyst for partial hydrolysis and condensation. In the case of direct production from chlorosilanes, by-product hydrochloric acid is used as a catalyst. And water and alcohol may be reacted.

Component A in the resin composition of the present invention may be used alone or in combination of two or more.
The content of component A in the resin composition for laser engraving of the present invention is preferably 0.1 to 80% by weight, and preferably 1 to 40% by weight, based on the total solid content of the resin composition. More preferred is 5 to 30% by weight. In addition, the solid content amount of the photosensitive resin composition represents an amount excluding volatile components such as a solvent.

(Component B) Thermal Base Generator The resin composition for laser engraving of the present invention contains (Component B) a thermal base generator. By containing a thermal base generator, both the stability of the composition, the printing durability and the rinsing properties can be achieved.
In the present invention, the thermal base generator is a compound that generates a base by heat or has a strong base action, and is classified into the following two types.
(Component B-1) Compound generating base by heat (Component B-2) Salt of base and acid Among these, (Component B-2) Salt of base and acid is preferable as the thermal base generator. A salt of an amine compound and an acid can be exemplified more preferably.
These are described in detail below.

(Component B-1) Compound that generates a base by heat Component B-1 is a compound that undergoes a decomposition reaction by heating to generate a base, and preferably exceeds 70 ° C. Component B-1 is preferably a compound decomposable at 80 to 120 ° C, more preferably a compound decomposable at 80 to 100 ° C.
Component B-1 includes organic acid and base salts that are decarboxylated and decomposed by heating, intramolecular nucleophilic substitution reaction, Rossen rearrangement, Beckmann rearrangement, etc. Those which cause some kind of reaction and release the base are preferably used.
Component B-1 includes a salt of trichloroacetic acid described in British Patent No. 998,949, a salt of α-sulfonylacetic acid described in US Pat. No. 4,060,420, No. 157637, a base precursor, a 2-carboxycarboxamide derivative, a base component described in JP-A-59-168440, and an organic base in addition to an organic base and a thermally decomposable acid using an alkaline earth metal. Salts, hydroxam carbamates utilizing the Lossen rearrangement described in JP-A-59-180537, and aldoxime carbamates described in JP-A-59-195237 that generate nitriles by heating. In addition, British Patent No. 998,945, US Pat. No. 3,220,846, British Patent No. 279,480, Japanese Patent Laid-Open Nos. 50-22625, 61-32844, 61-51139, 61 -52638, 61-51140, 61-53634 to 61-53640, 61-55644, 61-55645, and the like are preferably used. it can.

  Among these, as component B-1, carbamate derivatives such as 1-methyl-1- (4-biphenylyl) ethyl carbamate and 1,1-dimethyl-2-cyanoethyl carbamate, urea and N, N-dimethyl-N Urea derivatives such as' -methylurea, dihydropyridine derivatives such as 1,4-dihydronicotinamide, quaternized ammonium salts of organic silanes and organic boranes, dicyandiamide, potassium trichloroacetate, potassium phenylpropiolate, cesium phenylpropiolate, phenyl Preferred examples include tetramethylammonium sulfonylacetate and tetramethylammonium phenylpropiolate, and more preferred examples include potassium trichloroacetate and potassium phenylpropiolate.

(Component B-2) Salt of base and acid The resin composition for laser engraving of the present invention preferably contains, as Component B, a salt of (Component B-2) a base and an acid. By containing Component B-2, the stability of the composition, the printing durability, and the rinsing property can be made more compatible.
(Component B-2) The salt of base and acid in the resin composition for laser engraving of the present invention has low catalytic activity because the base and H ⁺ are strongly bonded at low temperature, but dissociates at high temperature. It is estimated that the catalytic activity is increased. At this time, not only the base but also the corresponding acid is generated, but the acid is a catalyst for promoting the crosslinking reaction of Component A and does not inhibit the intended reaction.
Component B-2 that can be used in the present invention is preferably a salt of an amine compound and an acid, from the viewpoint of compatibility between the stability of the composition, printing durability, and rinsing properties. A salt with an organic acid is more preferable, and a salt of a cycloamidine compound and an organic acid is particularly preferable.
Component B-2 may be an electrically neutralized salt. For example, even if it is a salt of 2 mole equivalents or more and a polyfunctional acid and salt, it is 2 mole equivalents or more of the polyfunctional amine compound. It may be a salt with an acid. Among these, a salt that is electrically neutralized with 1 molar equivalent of an acid with respect to 1 molar equivalent of a base is preferable.

<Amine compound>
Since the amine compound in Component B-2 forms a salt with an acid, it does not become a quaternary ammonium salt.
As an amine compound in Component B-2, specifically, hydrazine,
Primary amines are: monomethylamine, monoethylamine, monopropylamines, monobutylamines, monopentylamines, monohexylamines, monoheptylamines, vinylamine, allylamine, butenylamines, pentenylamines, hexenylamine , Pentadienylamines, hexadienylamines, cyclopentylamine, cyclohexylamine, cyclooctylamine, p-menthylamine, cyclopentenylamines, cyclohexenylamines, cyclohexadienylamines, aniline, benzylamine, Naphthylamine, naphthylmethylamine, toluidine, tolylenediamine, anisole, ethylenediamine, ethylenetriamine, monoethanolamine, aminothiophene, glycine, Nin, phenylalanine, and an amino acetone.

  Secondary amines include: dimethylamine, diethylamine, dipropylamines, dibutylamines, dipentylamines, dihexylamines, methylethylamine, methylpropylamines, methylbutylamines, methylpentylamines, methylhexyl Amines, ethylpropylamines, ethylbutylamines, ethylpentylamines, propylbutylamines, propylpentylamines, propylhexylamines, butylpentylamines, pentylhexylamines, divinylamine, diallylamine, dibutenylamines, dibutylamine Pentenylamines, dihexenylamines, methylvinylamine, methylallylamine, methylbutenylamines, methylpentenylamines, methylhexenylamines, ethyl Nilamine, ethylallylamine, ethylbutenylamine, ethylpentenylamines, ethylhexenylamines, propylvinylamines, propylallylamines, propylbutenylamines, propylpentenylamines, propylhexenylamines, butylvinylamines, Butylallylamines, butylbutenylamines, butylpentenylamines, butylhexenylamines, vinylallylamine, vinylbutenylamines, vinylpentenylamines, vinylhexenylamines, allylbutenylamines, allylpentenylamines, Allylhexenylamines, butenylpentenylamines, butenylhexenylamines, dicyclopentylamine, dicyclohexyl, methylcyclopentylamine, methyl Hexylamine, methylcyclooctylamine, ethylcyclopentylamine, ethylcyclohexylamine, ethylcyclooctylamine, propylcyclopentylamines, propylcyclohexylamines, butylcyclopentylamines, butylcyclohexylamines, hexylcyclopentylamines, hexylcyclohexylamines , Hexylcyclooctylamines, vinylcyclopentylamine, vinylcyclohexylamine, vinylcyclooctylamine, allylcyclopentylamine, allylcyclohexylamine, allylcyclooctylamine, butenylcyclopentylamines, butenylcyclohexylamines, butenylcyclooctylamine , Dicyclopentenylamines, dicyclohexenylamines Dicyclooctenylamines, methylcyclopentenylamines, methylcyclohexenylamines, methylcyclooctenylamines, ethylcyclopentenylamines,

Ethylcyclohexenylamines, ethylcyclooctenylamines, propylcyclopentenylamines, propylcyclohexenylamines, butylcyclopentenylamines, butylcyclohexenylamines, vinylcyclopentenylamines, vinylcyclohexenylamines, vinyl Cyclooctenylamines, allylcyclopentenylamines, allylcyclohexenylamines, butenylcyclopentenylamines, butenylcyclohexenylamines, dicyclopentadienylamine, dicyclohexadienylamines, dicyclooctadi Enylamines, methylcyclopentadienylamine, methylcyclohexadienylamines, ethylcyclopentadienylamine, ethylcyclohexadienylamines, propyl Clopentadienylamines, propylcyclohexadienylamines, dicyclooctatrienylamines, methylcyclooctatrienylamines, ethylcyclooctatrienylamines, vinylcyclopentadienylamine, vinylcyclohexadienylamine , Allylcyclopentadienylamine, allylcyclohexadienylamines, diphenylamine, ditolylamines, dibenzylamine, dinaphthylamines, N-methylaniline, N-ethylaniline, N-propylanilines, N-butylanilines N-methyltoluidine, N-ethyltoluidine, N-propyltoluidines, N-butyltoluidines, N-methylbenzylamine, N-ethylbenzylamines, N-propylbenzylamines, N-butyl Nylamines, N-methylnaphthylamines, N-ethylnaphthylamines, N-propylnaphthylamines, N-vinylaniline, N-allylaniline, N-vinylbenzylamine, N-allylbenzylamine, N-vinyltoluidine, N- Allyl toluidine, phenylcyclopentylamine, phenylcyclohexylamine, phenylcyclooctylamine, phenylcyclopentenylamine, phenylcyclohexenylamine, phenylcyclopentadienylamine, N-methylanizole, N-ethylanisole, N-vinylanisole, N -Allylanisole, N-methylethylenediamine, N, N'-dimethylethylenediamine, N-ethylethylenediamine, N, N'-diethylethylenediamine, N, N'-dimethyltri Rangeamines, N, N′-diethyltolylenediamines, N-methylethylenetriamine, N, N′-dimethylethylenetriamine, pyrrole, pyrrolidine, imidazole, piperidine, piperazine, methylpyrroles, methylpyrrolidines, methylimidazole , Methylpiperidines, methylpiperazines, ethylpyrroles, ethylpyrrolidines, ethylimidazoles, ethylpiperidines, ethylpiperazines, phthalimide, maleimide, caprolactam, pyrrolidone, morpholine, N-methylglycine, N-ethylglycine N-methylalanine, N-ethylalanine, N-methyl-aminothiophene, N-ethylaminothiophene, 2,5-piperazinedione, N-methylethanolamine, N-ethylethanolamine Emissions, such as pudding and the like.

  Tertiary amines are: trimethylamine, triethylamine, tripropylamines, tributylamines, tripentylamines, trihexylamines, dimethylethylamine, dimethylpropylamines, dimethylbutylamines, dimethylpentylamines, dimethyl Hexylamines, diethylpropylamines, diethylbutylamines, diethylpentylamines, diethylhexylamines, dipropylbutylamines, dipropylpentylamines, dipropylhexylamines, dibutylpentylamines, dibutylhexylamines, Dipentylhexylamines, methyldiethylamine, methyldipropylamines, methyldibutylamines, methyldipentylamines, methyldihexylamines, ethyl Dipropylamines, ethyldibutylamines, ethyldipentylamines, ethyldihexylamines, propyldibutylamines, propyldipentylamines, propyldihexylamines, butyldipentylamines, butyldihexylamines, pentyldihexylamines, Methylethylpropylamines, methylethylbutylamines, methylethylhexylamines, methylpropylbutylamines, methylpropylhexylamines, ethylpropylbutylamine, ethylbutylpentylamines, ethylbutylhexylamines, propylbutylpentylamines, propyl Butylhexylamines, butylpentylhexylamines, trivinylamine, triallylamine, tributenylamines, tripentenyl Mines, trihexenylamines, dimethylvinylamine, dimethylallylamine, dimethylbutenylamines, dimethylpentenylamines, diethylvinylamine, diethylallylamine, diethylbutenylamines, diethylpentenylamines, diethylhexenylamines, di Propylvinylamines, dipropylallylamines, dipropylbutenylamines, methyldivinylamine, methyldiallylamine, methyldibutenylamines, ethyldivinylamine, ethyldiallylamine, tricyclopentylamine, tricyclohexylamine, tricyclooctylamine, Tricyclopentenylamine, tricyclohexenylamine, tricyclopentadienylamine, tricyclohexadienylamines, dimethylcyclopentane Nethylamine, diethylcyclopentylamine, dipropylcyclopentylamines,

Dibutylcyclopentylamines, dimethylcyclohexylamine, diethylcyclohexylamine, dipropylcyclohexylamines, dimethylcyclopentenylamines, diethylcyclopentenylamines, dipropylcyclopentenylamines, dimethylcyclohexenylamines, diethylcyclohexenylamines, Dipropylcyclohexenylamines, methyldicyclopentylamine, ethyldicyclopentylamine, propylcyclopentylamines, methyldicyclohexylamine, ethyldicyclohexylamine, propylcyclohexylamines, methyldicyclopentenylamines, ethyldicyclopentenylamines, propyl Dicyclopentenylamines, N, N-dimethylaniline, N, N-dimethylbenzene Ziramine, N, N-dimethyltoluidines, N, N-dimethylnaphthylamines, N, N-diethylaniline, N, N-diethylbenzylamine, N, N-diethyltoluidines, N, N-diethylnaphthylamines, N , N-dipropylaniline, N, N-dipropylbenzylamine, N, N-dipropyltoluidine, N, N-dipropylnaphthylamine, N, N-divinylaniline, N, N-diallylaniline, N, N-divinyltoluidines, N, N-diallylaniline, diphenylmethylamine, diphenylethylamine, diphenylpropylamines, dibenzylmethylamine, dibenzylethylamine, dibenzylcyclohexylamine, dibenzylvinylamine, dibenzylallylamine, Ditrylmethylamine , Ditolylethylamines, ditolylcyclohexylamines, ditolylvinylamines, triphenylamine, tribenzylamine, tri (tolyl) amines, trinaphthylamines, N, N, N ′, N′-tetramethylethylenediamine N, N, N ′, N′-tetraethylethylenediamine, N, N, N ′, N′-tetramethyltolylenediamines, N, N, N ′, N′-tetraethyltolylenediamines, N-methyl Pyrrole, N-methylpyrrolidine, N-methylimidazole, N, N'-dimethylpiperazine, N-methylpiperidine, N-ethylpyrrole, N-methylpyrrolidine, N-ethylimidazole, N, N'-diethylpiperazine, N- Ethyl piperidine, pyridine, pyridazine, pyrazine, quinoline, quinazoline, quinu Klysine, N-methylpyrrolidone, N-methylmorpholine, N-ethylpyrrolidone, N-ethylmorpholine, N, N-dimethylanisole, N, N-diethylanisole, N, N-dimethylglycine, N, N-diethylglycine, N, N-dimethylalanine, N, N-diethylalanine, N, N-dimethylethanolamine, N, N-dimethylaminothiophene, 1,1,3,3-tetramethylguanidine, hexamethylenetetramine, the following cycloamidine compound Etc.

The amine compound in Component B-2 is preferably a primary to tertiary amine compound, and is a cycloamidine compound, from the viewpoint of compatibility between the stability of the composition, printing durability, and rinse performance. Is more preferable.
Moreover, it is preferable that the said cycloamidine compound is a compound represented by following formula (1).

（ｍは２〜６の整数を表し、Ｒはそれぞれ独立に、水素原子又は置換基を表す。）

(M represents an integer of 2 to 6, and each R independently represents a hydrogen atom or a substituent.)

In said Formula (1), m represents the integer of 2-6 and it is preferable that it is an integer of 3-5.
Examples of the substituent R that may substitute the hydrogen atom of the methylene group include an alkyl group having 1 to 6 carbon atoms (methyl, ethyl, isopropyl, n-butyl, t-butyl, n-hexyl, etc.), 6 hydroxyalkyl groups (such as hydroxymethyl, 2-hydroxyethyl, 2-hydroxypropyl, 2-hydroxyisopropyl, 3-hydroxy-t-butyl and 6-hydroxyhexyl), and dialkylamino groups having 2 to 12 carbon atoms (Dimethylamino, methylethylamino, diethylamino, diisopropylamino, t-butylmethylamino, di-n-hexylamino, etc.) are preferred.
Specific examples of the compound represented by the formula (1) include 1,5-diazabicyclo [4.3.0] -nonene-5 (DBN), 1,5-diazabicyclo [4.4.0]- Decene-5,1,8-diazabicyclo [5.4.0] -undecene-7 (DBU), 5-hydroxypropyl-1,8-diazabicyclo [5.4.0] -undecene-7 and 5-dibutylamino Preferred examples include -1,8-diazabicyclo [5.4.0] -undecene-7. Of these, DBN and DBU are preferred.
From the viewpoint of liquid stability, printing durability and rinsing properties, the pKaH (acid dissociation constant of the conjugate acid) of the amine compound used for Component B-2 is preferably 4 to 14, and preferably 9 to 14 More preferred is 11-13.

<Acid>
The acid in Component B-2 includes organic acids and inorganic acids.
Organic acids include carboxylic acids {saturated fatty acids (formic acid, acetic acid, 2-ethylhexanoic acid, isovaleric acid, etc.), unsaturated carboxylic acids (acrylic acid, crotonic acid, methacrylic acid, phthalic acid, isophthalic acid, terephthalic acid, Fumaric acid, maleic acid, palmitoleic acid, oleic acid, linoleic acid, linolenic acid, vaccenic acid, elestearic acid, arachidonic acid, cinnamic acid, naphthoic acid, benzoic acid and toluic acid), β-substituted acetic acid (chloroacetic acid, Cyanoacetic acid, dichloroacetic acid, trichloroacetic acid, trimethylacetic acid, fluoroacetic acid, bromoacetic acid, methoxyacetic acid, mercaptoacetic acid, iodoacetic acid, vinylacetic acid, oxaloacetic acid, phenylacetic acid and phenoxyacetic acid), dicarboxylic acid (succinic acid, malonic acid, succinic acid) Acid, glutaric acid, adipic acid, arazeic acid, suberic acid and sebashi Acid), hydroxycarboxylic acid (glycolic acid, lactic acid, citric acid, d-tartaric acid, mesotartaric acid, ascorbic acid, mandelic acid, etc.), ketocarboxylic acid (pyruvic acid, levulinic acid etc.), halocarboxylic acid (2-chloropropionic acid) And 3-chloropropionic acid)}, monoalkyl carbonate (such as methyl carbonate and ethyl carbonate), aromatic hydroxy compounds (such as phenol, cresol, catechol and naphthol), and sulfonic acid (octylbenzene sulfonic acid, butylbenzene sulfone) Acid, toluenesulfonic acid, benzenesulfonic acid, methanesulfonic acid and the like).
Inorganic acids include halogen acids (hydrochloric acid, hydrofluoric acid, bromic acid, etc.), carbonic acid (forms carbonate or hydrogen carbonate), perhalogen acids (perchloric acid, perbromic acid, etc.), sulfuric acid, And phosphoric acid etc. are mentioned.
Of these acids, organic acids are preferred, such as carboxylic acids, aromatic hydroxy compounds, and the like. Sulfonic acid is more preferred, saturated fatty acids and aromatic hydroxy compounds are more preferred, and formic acid, acetic acid, 2-ethylhexanoic acid and phenol are particularly preferred.
The pKa range of the acid used for Component B-2 is preferably -16 to 20, more preferably -5 to 16, and still more preferably 0 to 12.
The base and acid forming component B-2 may be used after being mixed and neutralized in advance, or may be mixed and neutralized in the system.

Component B in the resin composition of the present invention may be used alone or in combination of two or more.
The content of Component B in the resin composition for laser engraving of the present invention is preferably 0.01 to 30% by weight, and 0.05 to 20% by weight with respect to the total solid content of the resin composition. More preferably, the content is 0.1 to 10% by weight.

(Component C) Binder Polymer The resin composition for laser engraving of the present invention contains (Component C) a binder polymer.
The binder polymer is a polymer component contained in the resin composition for laser engraving. A general polymer compound is appropriately selected, and one kind can be used alone, or two or more kinds can be used in combination. . In particular, when the resin composition for laser engraving is used for the printing plate precursor, it is preferable to select in consideration of various performances such as laser engraving property, ink acceptability, and engraving residue dispersibility.
As binder polymer, polystyrene resin, polyester resin, polyamide resin, polysulfone resin, polyethersulfone resin, polyimide resin, hydrophilic polymer containing hydroxyethylene unit, acrylic resin, acetal resin, epoxy resin, polycarbonate resin, rubber, thermoplastic It can be used by selecting from an elastomer or the like.
For example, from the viewpoint of laser engraving sensitivity, a polymer containing a partial structure that is thermally decomposed by exposure or heating is preferable. Preferred examples of such a polymer include those described in paragraph 0038 of JP2008-163081A. For example, when the purpose is to form a soft and flexible film, a soft resin or a thermoplastic elastomer is selected. This is described in detail in paragraphs 0039 to 0040 of JP 2008-163081 A. Furthermore, if the resin composition for laser engraving is applied to the relief forming layer in the relief printing plate precursor for laser engraving, the ease of preparation of the composition for the relief forming layer, the oil-based ink in the resulting relief printing plate It is preferable to use a hydrophilic or alcoholic polymer from the viewpoint of improving the resistance to water. As the hydrophilic polymer, those described in detail in paragraph 0041 of JP-A-2008-163081 can be used.

In addition, when used for the purpose of curing by heating or exposure and improving the strength, a polymer having an ethylenically unsaturated bond in the molecule is preferably used.
Examples of such a polymer that includes an ethylenically unsaturated bond in the main chain include SB (polystyrene-polybutadiene), SBS (polystyrene-polybutadiene-polystyrene), SIS (polystyrene-polyisoprene-polystyrene), SEBS ( Polystyrene-polyethylene / polybutylene-polystyrene) and the like.
As a polymer having an ethylenically unsaturated bond in the side chain, an ethylenically unsaturated group such as an allyl group, an acryloyl group, a methacryloyl group, a styryl group, or a vinyl ether group is introduced into the side chain of the binder polymer described later. Can be obtained. The method for introducing an ethylenically unsaturated group into the side chain of the binder polymer is as follows: (1) copolymerizing a structural unit having a polymerizable group precursor formed by bonding a protective group to a polymerizable group to remove the protective group. (2) A polymer compound having a plurality of reactive groups such as a hydroxyl group, an amino group, an epoxy group, and a carboxyl group, and a group that reacts with these reactive groups and an ethylenic group. Known methods such as a method of introducing a compound having an unsaturated group by a polymer reaction can be employed. According to these methods, the amount of ethylenically unsaturated groups introduced into the polymer compound can be controlled.

(Component C) The binder polymer reacts with the hydrolyzable silyl group and / or silanol group in the compound having a hydrolyzable silyl group and / or silanol group described in detail below to form a crosslinked structure. It is preferably a binder polymer having a functional group that can be used (hereinafter appropriately referred to as “reactive functional group”).
The reactive functional group contained in Component C is not particularly limited as long as it is a group capable of reacting with a hydrolyzable silyl group and / or silanol group in Component A to form a —Si—O— bond. Group, silanol group and hydrolyzable silyl group are preferred.

  The reactive functional group may be present anywhere in the polymer molecule, but is preferably present in the side chain of the chain polymer. Examples of such polymers include vinyl copolymers (copolymers of vinyl monomers such as polyvinyl alcohol and polyvinyl acetal and derivatives thereof), acrylic resins (copolymers of acrylic monomers such as hydroxyethyl (meth) acrylate), and the like. Derivatives) can be preferably exemplified.

The method for introducing the reactive functional group into the binder polymer is not particularly limited, and is a method of addition (co) polymerization or polycondensation of a monomer having a reactive functional group, a polymer having a group derivable to the reactive functional group. And a method of deriving the polymer into a reactive functional group by a polymer reaction.
As the polymer of component C, (B-1) a binder polymer having a hydroxyl group is particularly preferably used. This will be described below.

(C-1) Binder polymer having hydroxyl group Hereinafter, as the vaninder polymer of component C in the resin composition of the present invention, (C-1) a binder polymer having a hydroxyl group (hereinafter also referred to as "specific polymer"). ) Is preferred. This specific polymer is preferably insoluble in water and soluble in an alcohol having 1 to 4 carbon atoms.
As component C-1, the resin composition for laser engraving which provides a relief forming layer having both engraving sensitivity and good film property while achieving both water-based ink suitability and UV ink suitability includes polyvinyl acetal and its derivatives, side Preferable examples include an acrylic resin having a hydroxyl group in the chain and an epoxy resin having a hydroxyl group in the side chain.

  Component C-1 preferably has a glass transition temperature (Tg) of 20 ° C. or higher. When combined with a photothermal conversion agent capable of absorbing light having a wavelength of 700 nm to 1,300 nm, which is an optional component (component F), the glass transition temperature (Tg) of the binder polymer is 20 ° C. or higher, thereby engraving sensitivity. Will improve. Hereinafter, the binder polymer having such a glass transition temperature is also referred to as “non-elastomer”. Although there is no restriction | limiting in the upper limit of the glass transition temperature of a binder polymer, it is preferable from a viewpoint of handleability that it is 200 degrees C or less, and it is more preferable that it is 25 degreeC or more and 120 degrees C or less.

When a polymer having a glass transition temperature of room temperature (20 ° C.) or higher is used, the specific polymer takes a glass state at room temperature. Therefore, compared to a rubber state, the thermal molecular motion is considerably suppressed. It is in. In laser engraving, heat generated by the function of a photothermal conversion agent capable of absorbing light having a wavelength of 700 to 1,300 nm (component F) used in combination with heat in addition to heat given by an infrared laser at the time of laser irradiation. It is presumed that it is transferred to a specific polymer existing in the surroundings, and this is thermally decomposed and dissipated, resulting in engraving and forming a recess.
When a specific polymer is used, if a photothermal conversion agent is present in a state where thermal molecular motion of the specific polymer is suppressed, heat transfer to the specific polymer and thermal decomposition are considered to occur effectively. It is presumed that the engraving sensitivity is further increased by this effect.

  Specific examples of the non-elastomer polymer preferably used in the present invention are listed below.

(1) Polyvinyl acetal and derivatives thereof Polyvinyl acetal is a compound obtained by cyclic acetalization of polyvinyl alcohol (obtained by saponifying polyvinyl acetate). Further, the polyvinyl acetal derivative is obtained by modifying the polyvinyl acetal or adding another copolymer component.
The acetal content in the polyvinyl acetal derivative is preferably 30 to 90%, more preferably 50 to 85%, assuming that the total number of moles of the raw vinyl acetate monomer is 100%, and the mole percentage of vinyl alcohol units to be acetalized. 55 to 78% is particularly preferable.
The vinyl alcohol unit in the polyvinyl acetal derivative is preferably 10 to 70 mol%, more preferably 15 to 50 mol%, particularly preferably 22 to 45 mol%, based on the total number of moles of the starting vinyl acetate monomer.
Moreover, the polyvinyl acetal may have a vinyl acetate unit as another component, and as its content, 0.01-20 mol% is preferable and 0.1-10 mol% is still more preferable. The polyvinyl acetal derivative may further have other copolymer units.
Examples of the polyvinyl acetal include polyvinyl butyral, polyvinyl propylal, polyvinyl ethylal, and polyvinyl methylal. Among these, polyvinyl butyral derivative (PVB) is preferable.
Polyvinyl butyral is usually a polymer obtained by converting polyvinyl alcohol into butyral. A polyvinyl butyral derivative may also be used.
Examples of polyvinyl butyral derivatives include acid-modified PVB in which at least part of the hydroxyl group is modified to an acid group such as a carboxyl group, modified PVB in which part of the hydroxyl group is modified to a (meth) acryloyl group, and at least part of the hydroxyl group is an amino group Modified PVB, modified PVB in which ethylene glycol, propylene glycol, or a multimer thereof is introduced into at least a part of the hydroxyl group.
The molecular weight of the polyvinyl acetal is preferably 5,000 to 800,000, more preferably 8,000 to 500,000 as a weight average molecular weight from the viewpoint of maintaining a balance between engraving sensitivity and film property. Furthermore, from the viewpoint of improving the rinse performance of engraving residue, it is particularly preferably 50,000 to 300,000.

Hereinafter, although polyvinyl butyral (PVB) and its derivative (s) are mentioned and demonstrated as a particularly preferable example of polyvinyl acetal, it is not limited to this.
The structure of polyvinyl butyral is as shown below, and includes these structural units.

In the above formula, l, m, and n represent the content (mol%) of each repeating unit in the above formula in polyvinyl butyral, and satisfy the relationship of l + m + n = 100. The butyral content (value of l in the above formula) in polyvinyl butyral and its derivatives is preferably 30 to 90 mol%, more preferably 40 to 85 mol%, particularly preferably 45 to 78 mol%.
From the viewpoint of balance between engraving sensitivity and film property, the weight average molecular weight of polyvinyl butyral and its derivatives is preferably 5,000 to 800,000, more preferably 8,000 to 500,000, and the rinse property of engraving residue is improved. From this viewpoint, 50,000 to 300,000 are particularly preferable.

Derivatives of PVB are also available as commercial products, and preferred specific examples thereof include “ESREC B” series and “ESREC K” manufactured by Sekisui Chemical Co., Ltd. from the viewpoint of alcohol solubility (particularly ethanol). (KS) "series," Denkabutyral "manufactured by Denki Kagaku Kogyo Co., Ltd. are preferred. More preferably, from the viewpoint of alcohol solubility (especially ethanol), “S Lec B” series manufactured by Sekisui Chemical Co., Ltd. and “Denka Butyral” manufactured by Denki Kagaku Kogyo Co., Ltd. are preferred. Among these, particularly preferred commercial products are shown below together with the values of l, m and n and the molecular weight in the above formula. In the “S Lec B” series manufactured by Sekisui Chemical Co., Ltd., “BL-1” (l = 61, m = 3, n = 36 weight average molecular weight 19000), “BL-1H” (l = 67 , M = 3, n = 30 weight average molecular weight 2 million), “BL-2” (l = 61, m = 3, n = 36 weight average molecular weight about 27,000), “BL-5” ( l = 75, m = 4, n = 21 weight average molecular weight 32,000), “BL-S” (l = 74, m = 4, n = 22 weight average molecular weight 23,000), “BM-S (L = 73, m = 5, n = 22 weight average molecular weight 53,000), “BH-S” (l = 73, m = 5, n = 22 weight average molecular weight 66,000), In the “Denkabutyral” series manufactured by Denki Kagaku Kogyo Co., Ltd., “# 3000-1” (l = 71, m = 1, n = 28 weight average molecular weight 74,000), “# 3000-2 "(l = 71, m = 1, n = 28 weight average molecular weight 90000),"# 3000-4 "(l = 71, m = 1, n = 28 weight average molecular weight 17,000 ), “# 4000-2” (l = 71, m = 1, n = 28 weight average molecular weight 152,000), “# 6000-C” (l = 64, m = 1, n = 35 weight average molecular weight) 308,000), “# 6000-EP” (l = 56, m = 15, n = 29 weight average molecular weight 381,000), “# 6000-CS” (l = 74, m = 1, n = 25 weight average molecular weight 322,000) and “# 6000-AS” (l = 73, m = 1, n = 26 weight average molecular weight 242,000).
When a relief forming layer is formed using a PVB derivative as a specific polymer, a method in which a solution dissolved in a solvent is cast and dried is preferable from the viewpoint of the smoothness of the film surface.

(2) Acrylic resin The acrylic resin that can be used as the specific polymer may be an acrylic resin obtained by using a known acrylic monomer and has a hydroxyl group in the molecule.
As the acrylic monomer used for the synthesis of the acrylic resin having a hydroxyl group, for example, (meth) acrylic acid esters and crotonic acid esters (meth) acrylamides having a hydroxyl group in the molecule are preferable. Specific examples of such a monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and the like.
In the present invention, “(meth) acryl” is a term including one or both of “acryl” and “methacryl”, and “(meth) acrylate” is “acryl”. And “methacrylic”, or both.

Moreover, as an acrylic resin, acrylic monomers other than the acrylic monomer which has the said hydroxyl group can also be included as a copolymerization component. Examples of the acrylic monomer include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, acetoxyethyl (meth) acrylate, phenyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (Meth) acrylate, 2- (2-methoxyethoxy) ethyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, diethylene glycol monomethyl ether (meth) acrylate, di Tylene glycol monoethyl ether (meth) acrylate, diethylene glycol monophenyl ether (meth) acrylate, triethylene glycol monomethyl ether (meth) acrylate, triethylene glycol monoethyl ether (meth) acrylate, dipropylene glycol monomethyl ether (meth) acrylate, Polyethylene glycol monomethyl ether (meth) acrylate, polypropylene glycol monomethyl ether (meth) acrylate, monomethyl ether (meth) acrylate of a copolymer of ethylene glycol and propylene glycol, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) a Relate and the like.
Furthermore, a modified acrylic resin comprising an acrylic monomer having a urethane group or a urea group can also be preferably used.
Among these, alkyl (meth) acrylates such as lauryl (meth) acrylate and (meth) acrylates having an aliphatic cyclic structure such as t-butylcyclohexyl methacrylate are particularly preferable from the viewpoint of water-based ink resistance.

(3) Novolak resin Moreover, the novolak resin which is resin which condensed phenols and aldehydes on acidic conditions can be used as a specific polymer.
Preferred novolak resins include, for example, novolak resins obtained from phenol and formaldehyde, novolak resins obtained from m-cresol and formaldehyde, novolak resins obtained from p-cresol and formaldehyde, novolak resins obtained from o-cresol and formaldehyde, and octylphenol. And novolak resins obtained from formaldehyde, m- / p-mixed cresol and novolak resins obtained from formaldehyde, phenol / cresol (m-, p-, o- or m- / p-, m- / o-, o- / P-mixed) and a novolak resin obtained from formaldehyde.
These novolak resins preferably have a weight average molecular weight of 800 to 200,000 and a number average molecular weight of 400 to 60,000.
It is also possible to use an epoxy resin having a hydroxyl group in the side chain as the specific polymer. As a preferred specific example, an epoxy resin obtained by polymerizing an adduct of bisphenol A and epichlorohydrin as a raw material monomer is preferable.
These epoxy resins preferably have a weight average molecular weight of 800 to 200,000 and a number average molecular weight of 400 to 60,000.

Among the specific polymers, polyvinyl butyral derivatives are particularly preferable from the viewpoints of rinsing properties and printing durability when used as a relief forming layer.
The content of the hydroxyl group contained in the specific polymer in the present invention is preferably 0.1 to 15 mmol / g, more preferably 0.5 to 7 mmol / g in any of the above-described polymers. .

In the resin composition for laser engraving, in addition to the specific polymer, a known polymer that is not included in the specific polymer such as a polymer having no hydroxyl group can be used alone or in combination with the specific polymer. Hereinafter, such a polymer is also referred to as a general polymer.
The general polymer constitutes the main component contained in the resin composition for laser engraving together with the specific polymer. A general polymer compound not included in the specific polymer is appropriately selected, and one or two or more types are selected. Can be used. In particular, when the relief forming plate precursor is used as a printing plate precursor, it is necessary to select a binder polymer in consideration of various performances such as laser engraving property, ink acceptability, and engraving residue dispersibility.

  General polymers include polystyrene resin, polyester resin, polyamide resin, polyurea polyamideimide resin, polyurethane resin, polysulfone resin, polyethersulfone resin, polyimide resin, polycarbonate resin, hydrophilic polymer containing hydroxyethylene units, acrylic resin, acetal resin , Polycarbonate resin, rubber, thermoplastic elastomer and the like.

  For example, from the viewpoint of laser engraving sensitivity, a polymer containing a partial structure that is thermally decomposed by exposure or heating is preferable. Preferred examples of such a polymer include those described in paragraph 0038 of JP2008-163081A. For example, when the purpose is to form a soft and flexible film, a soft resin or a thermoplastic elastomer is selected. This is described in detail in paragraphs 0039 to 0040 of JP 2008-163081 A. Furthermore, it is preferable to use a hydrophilic or alcoholic polymer from the viewpoint of easy preparation of the composition for a relief forming layer and improvement in resistance to oil-based ink in the obtained relief printing plate. As the hydrophilic polymer, those described in detail in paragraph 0041 of JP-A-2008-163081 can be used.

Among the specific polymers, polyvinyl butyral derivatives are particularly preferable from the viewpoints of rinsing properties and printing durability when used as a relief forming layer.
The hydroxyl group content contained in the specific polymer is preferably 0.1 to 15 mmol / g, more preferably 0.5 to 7 mmol / g, in any of the above-described polymers.

In the resin composition for laser engraving of the present invention, only one type of component C may be used, or two or more types may be used in combination.
The content of component C in the resin composition for laser engraving of the present invention is 2 to 2 with respect to the total solid content of the resin composition, from the viewpoint of satisfying a good balance of form retention, water resistance and engraving sensitivity. It is preferably 95% by weight, more preferably 5 to 80% by weight, and particularly preferably 10 to 60% by weight.

(Component D) Polymerizable Compound In the present invention, from the viewpoint of forming a crosslinked structure in the relief forming layer, in order to form this, the resin composition for laser engraving of the present invention comprises (Component D) a polymerizable compound. It is preferable to contain.
The polymerizable compound that can be used in the present invention can be arbitrarily selected from compounds having at least one ethylenically unsaturated double bond, preferably two or more, and more preferably 2 to 6.

Hereinafter, a monofunctional monomer having one ethylenically unsaturated double bond in the molecule and a polyfunctional monomer having two or more such bonds in the molecule, which are used as the polymerizable compound, will be described.
Since the crosslinked relief forming layer in the relief printing plate precursor of the present invention needs to have a crosslinked structure in the film, a polyfunctional monomer is preferably used. The molecular weight of these polyfunctional monomers is preferably 200 to 2,000.
Monofunctional monomers include esters of unsaturated carboxylic acids (eg, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.) and monohydric alcohol compounds, unsaturated carboxylic acids and monovalent amine compounds And amides. Polyfunctional monomers include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.) and polyhydric alcohol compounds, unsaturated carboxylic acids and polyvalent monomers. Examples include amides with amine compounds.
Further, addition reaction products of unsaturated carboxylic acid esters or amides having a nucleophilic substituent such as hydroxyl group, amino group, mercapto group and the like with monofunctional or polyfunctional isocyanates or epoxies, and monofunctional or polyfunctional A dehydration condensation reaction product with a functional carboxylic acid is also preferably used.

Furthermore, an addition reaction product of an unsaturated carboxylic acid ester or amide having an electrophilic substituent such as an epoxy group or an epoxy group with a monofunctional or polyfunctional alcohol, amine or thiol, further a halogeno group or In addition, a substitution reaction product of an unsaturated carboxylic acid ester or amide having a leaving substituent such as a tosyloxy group and a monofunctional or polyfunctional alcohol, amine or thiol is also suitable.
As another example, it is also possible to use a group of compounds substituted with unsaturated phosphonic acid, styrene, vinyl ether or the like instead of the unsaturated carboxylic acid.
There is no restriction | limiting in particular as a polymeric compound, In addition to the compound illustrated above, well-known various compounds can be used, For example, the compound etc. of Paragraphs 0098-0124 of JP, 2009-204962, A etc. are used. May be.

In the present invention, from the viewpoint of improving engraving sensitivity, a compound having a sulfur atom in the molecule is preferably used as the polymerizable compound.
Thus, as a polymeric compound which has a sulfur atom in a molecule | numerator, from a viewpoint of engraving sensitivity improvement, it has two or more ethylenically unsaturated bonds especially, and connects between two ethylenically unsaturated bonds among them. It is preferable to use a polymerizable compound having a carbon-sulfur bond at the site (hereinafter appropriately referred to as “sulfur-containing polyfunctional monomer”).

The functional group containing a carbon-sulfur bond in the sulfur-containing polyfunctional monomer in the present invention includes sulfide, disulfide, sulfoxide, sulfonyl, sulfonamide, thiocarbonyl, thiocarboxylic acid, dithiocarboxylic acid, sulfamic acid, thioamide, and thiocarbamate. , A functional group containing dithiocarbamate or thiourea.
In addition, as a linking group containing a carbon-sulfur bond that links two ethylenically unsaturated bonds in a sulfur-containing polyfunctional monomer, -C-S-, -CSS-, -NHC (= S It is preferably a linking group containing at least one unit selected from O—, —NHC (═O) S—, —NHC (═S) S—, and —C—SO ₂ —.

Further, the number of sulfur atoms contained in the molecule of the sulfur-containing polyfunctional monomer is not particularly limited as long as it is 1 or more, and can be appropriately selected according to the purpose. From the viewpoint of balance, 1 to 10 is preferable, 1 to 5 is more preferable, and 1 to 2 is more preferable.
On the other hand, the number of ethylenically unsaturated groups contained in the molecule is not particularly limited as long as it is 2 or more, and can be appropriately selected according to the purpose. -10 are preferable, 2-6 are more preferable, and 2-4 are still more preferable.

The molecular weight of the sulfur-containing polyfunctional monomer in the present invention is preferably 120 to 3,000, more preferably 120 to 1,500, from the viewpoint of the flexibility of the formed film.
Moreover, although the sulfur-containing polyfunctional monomer in this invention may be used independently, you may use it as a mixture with the polyfunctional polymerizable compound and monofunctional polymerizable compound which do not have a sulfur atom in a molecule | numerator.
Specific examples of the polymerizable compound having a sulfur atom in the molecule include those described in paragraphs 0032 to 0037 of JP-A-2009-255510, and the compounds described herein are used in the present invention. Also good.
From the viewpoint of engraving sensitivity, it is preferable to use a sulfur-containing polyfunctional monomer alone or as a mixture of a sulfur-containing polyfunctional monomer and a monofunctional ethylenic monomer, more preferably a sulfur-containing polyfunctional monomer and a monofunctional. This is an embodiment used as a mixture with an ethylenic monomer.

The resin composition for laser engraving of the present invention can also adjust film physical properties such as brittleness and flexibility by using a polymerizable compound including a sulfur-containing polyfunctional monomer.
Moreover, the total content of the (component D) polymerizable compound in the resin composition for laser engraving of the present invention is 10 to 60 with respect to the total solid content of the resin composition from the viewpoint of flexibility and brittleness of the crosslinked film. % By weight is preferred, and a range of 15 to 45% by weight is more preferred.
In addition, when using together a sulfur-containing polyfunctional monomer and another polymeric compound, 5 weight% or more is preferable and, as for the quantity of the sulfur-containing polyfunctional monomer in all the polymeric compounds, 10 weight% or more is more preferable.

(Component E) Polymerization initiator When the resin composition for laser engraving of the present invention is used for producing a relief forming layer, it is preferable to further contain (Component E) a polymerization initiator.
As the polymerization initiator, those known to those skilled in the art can be used without limitation. Hereinafter, although the radical polymerization initiator which is a preferable polymerization initiator is explained in full detail, this invention is not restrict | limited by these description.

  In the present invention, preferred radical polymerization initiators include (a) aromatic ketones, (b) onium salt compounds, (c) organic peroxides, (d) thio compounds, (e) hexaarylbiimidazole compounds, (F) ketoxime ester compound, (g) borate compound, (h) azinium compound, (i) metallocene compound, (j) active ester compound, (k) compound having carbon halogen bond, (l) azo compound, etc. Is mentioned. Specific examples of the above (a) to (l) are given below, but the present invention is not limited to these.

  In the present invention, from the viewpoint of engraving sensitivity and a good relief edge shape when applied to a relief forming layer of a relief printing plate precursor, (c) an organic peroxide and (l) an azo compound are more Preferably, (c) an organic peroxide is particularly preferable.

(A) aromatic ketones, (b) onium salt compounds, (d) thio compounds, (e) hexaarylbiimidazole compounds, (f) ketoxime ester compounds, (g) borate compounds, (h) azinium compounds As (i) metallocene compounds, (j) active ester compounds, and (k) compounds having a carbon halogen bond, the compounds listed in paragraphs 0074 to 0118 of JP-A-2008-63554 are preferably used. it can.
In addition, (c) the organic peroxide and (l) the azo compound are preferably the following compounds.

(C) Organic peroxide Preferred as a radical polymerization initiator that can be used in the present invention (c) As the organic peroxide, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone 3,3 ′, 4,4′-tetra (t-amylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (t-hexylperoxycarbonyl) benzophenone, 3,3 ′, 4, 4'-tetra (t-octylperoxycarbonyl) benzophenone, 3,3 ', 4,4'-tetra (cumylperoxycarbonyl) benzophenone, 3,3', 4,4'-tetra (p-isopropylcumylper) Peroxyesters such as oxycarbonyl) benzophenone and di-t-butyldiperoxyisophthalate are preferred.

(L) Azo-based compound Preferred as a radical polymerization initiator that can be used in the present invention (l) As the azo-based compound, 2,2′-azobisisobutyronitrile, 2,2′-azobispropionitrile 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2 '-Azobis (4-methoxy-2,4-dimethylvaleronitrile), 4,4'-azobis (4-cyanovaleric acid), dimethyl 2,2'-azobisisobutyrate, 2,2'-azobis (2-methyl) Propionamidoxime), 2,2'-azobis [2- (2-imidazolin-2-yl) propane], 2,2'-azobis {2-methyl-N- [1,1-bis (hydroxymethyl)- 2 Hydroxyethyl] propionamide}, 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) propionamide], 2,2′-azobis (N-butyl-2-methylpropionamide), 2, 2'-azobis (N-cyclohexyl-2-methylpropionamide), 2,2'-azobis [N- (2-propenyl) -2-methylpropionamide], 2,2'-azobis (2,4,4 -Trimethylpentane) and the like.

  In the present invention, the organic peroxide (c) is preferably used as a polymerization initiator in the present invention from the viewpoint of the crosslinkability of the film (relief-forming layer). Further, as an unexpected effect, the engraving sensitivity is improved. It was found that this is particularly preferable from the viewpoint.

From the viewpoint of engraving sensitivity, an embodiment in which this (c) organic peroxide and (component C) a polymer having a glass transition temperature of normal temperature (20 ° C.) or higher as a binder polymer is particularly preferred.
This is because when an organic peroxide is used to cure the relief forming layer by thermal crosslinking, unreacted organic peroxide that does not participate in radical generation remains, but the remaining organic peroxide is self-reactive. Works as an additive and decomposes exothermically during laser engraving. As a result, it is presumed that the engraving sensitivity is increased because the heat generated is added to the irradiated laser energy.
In particular, when the glass transition temperature of (Component C) the binder polymer is room temperature (20 ° C.) or higher, the heat generated from the decomposition of the organic peroxide is efficiently transferred to the binder polymer, and (Component C) the binder It is presumed that the sensitivity is increased because it is effectively used for thermal decomposition of the polymer itself.
In addition, although explained in full detail in description of a photothermal conversion agent, this effect is remarkable when using carbon black as a photothermal conversion agent. This is because (c) heat generated from carbon black is transferred to (c) organic peroxide, and heat is generated not only from carbon black but also from organic peroxide, so it is used for decomposition of (component C) binder polymer, etc. This is thought to be due to the synergistic generation of heat energy that should be achieved.

In the present invention, the (component E) polymerization initiator may be used alone or in combination of two or more.
The content of the (component E) polymerization initiator in the resin composition for laser engraving of the present invention is preferably 0.01 to 10% by weight, preferably 0.1 to 3% by weight, based on the total solid content of the resin composition. Is more preferable. By setting the content of the polymerization initiator to 0.01% by weight or more, the effect of adding this is obtained, and the crosslinkable relief forming layer is rapidly crosslinked. Further, when the content is 10% by weight or less, other components are not deficient, and printing durability sufficient for use as a relief printing plate can be obtained.

(Component F) Photothermal conversion agent capable of absorbing light having a wavelength of 700 to 1,300 nm The resin composition for laser engraving of the present invention comprises (Component F) photothermal conversion capable of absorbing light having a wavelength of 700 to 1,300 nm. It is preferable to further contain an agent (hereinafter, also simply referred to as “photothermal conversion agent”). That is, it is considered that the photothermal conversion agent in the present invention promotes thermal decomposition of a cured product during laser engraving by absorbing laser light and generating heat. For this reason, it is preferable to select a photothermal conversion agent that absorbs light having a laser wavelength used for engraving.

When the crosslinked relief forming layer in the relief printing plate precursor for laser engraving of the present invention is used for laser engraving using a laser emitting a infrared ray of 700 to 1,300 nm (YAG laser, semiconductor laser, fiber laser, surface emitting laser, etc.) as a light source In addition, as the photothermal conversion agent, it is preferable to use a compound having a maximum absorption wavelength at 700 to 1,300 nm.
Various dyes or pigments are used as the photothermal conversion agent that can be used in the present invention.

  Among the photothermal conversion agents, as the dye, commercially available dyes and known ones described in documents such as “Dye Handbook” (edited by the Society for Synthetic Organic Chemistry, published in 1970) can be used. Specifically, those having a maximum absorption wavelength at 700 nm to 1,300 nm are preferably mentioned, and azo dyes, metal complex azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes , Diimmonium compounds, quinoneimine dyes, methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, metal thiolate complexes, and the like.

  Dyes preferably used in the present invention include cyanine dyes such as heptamethine cyanine dyes, oxonol dyes such as pentamethine oxonol dyes, phthalocyanine dyes, and paragraphs 0124 to 0137 of JP-A-2008-63554. Mention may be made of dyes.

  Among the photothermal conversion agents used in the present invention, commercially available pigments and color index (CI) manuals, “latest pigment manuals” (edited by the Japan Pigment Technical Association, published in 1977), “latest pigment application” The pigments described in “Technology” (CMC Publishing, 1986) and “Printing Ink Technology” CMC Publishing, 1984) can be used.

  Examples of the pigment include black pigments, yellow pigments, orange pigments, brown pigments, red pigments, purple pigments, blue pigments, green pigments, fluorescent pigments, metal powder pigments, and other polymer-bonded dyes. Specifically, insoluble azo pigments, azo lake pigments, condensed azo pigments, chelate azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene and perinone pigments, thioindigo pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments , Quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black, and the like. Of these pigments, carbon black is preferred.

  As long as the dispersibility in the composition is stable, carbon black can be used regardless of the classification according to ASTM or the use (for example, for color, for rubber, for dry battery, etc.). Carbon black includes, for example, furnace black, thermal black, channel black, lamp black, acetylene black and the like. In order to facilitate dispersion, black colorants such as carbon black can be used as color chips or color pastes previously dispersed in nitrocellulose or a binder, if necessary. Such chips and pastes can be easily obtained as commercial products.

  In the present invention, it is also possible to use carbon black having a relatively low specific surface area and relatively low DBP (dibutyl phthalate) absorption and even finer carbon black having a large specific surface area. Examples of suitable carbon blacks include Printex® U, Printex® A, or Specialschwarz® 4 (Degussa).

The carbon black that can be used in the present invention has a specific surface area of 150 m ² / g or more and a DBP number from the viewpoint of improving engraving sensitivity by efficiently transferring heat generated by photothermal conversion to surrounding polymers. Conductive carbon black that is 150 ml / 100 g or more is preferred.

This specific surface area is preferably 250 m ² / g or more, particularly preferably 500 m ² / g or more. The DBP number is preferably 200 m ² / g or more, particularly preferably 250 ml / 100 g or more. The carbon black described above may be acidic or basic carbon black. The carbon black is preferably basic carbon black. Of course, mixtures of different binders can also be used.

Conductive carbon black having a specific surface area of 150 to about 1,500 m ² / g and a DBP number of 150 to about 550 ml / 100 g are, for example, Ketjenblack (registered trademark) EC300J, Ketjenblack (registered trademark) EC600J ( Commercially available under the names Akzo), Princex (registered trademark) XE (Degussa), Black Pearls (registered trademark) 2000 (Cabot), or Ketjen Black (Lion) Is possible.

When carbon black is used as the photothermal conversion agent, thermal crosslinking is preferred from the viewpoint of film curability, rather than photocrosslinking using UV light or the like, and is a preferred combination component as described above (component E). It is more preferable to use the organic peroxide in combination with an agent because the engraving sensitivity is extremely high.
The most preferred embodiment of the present invention is an embodiment in which (Component C) a binder polymer is used and (Component F) is used in combination with carbon black which is a photothermal conversion agent capable of absorbing light having a wavelength of 700 to 1,300 nm. Can be mentioned.

  In the resin composition for laser engraving of the present invention, the content of (component F) a photothermal conversion agent capable of absorbing light having a wavelength of 700 to 1,300 nm varies greatly depending on the molecular extinction coefficient inherent to the molecule. The total solid content of the resin composition is preferably 0.01 to 20% by weight, more preferably 0.05 to 10% by weight, and particularly preferably 0.1 to 5% by weight.

<Solvent>
The resin composition for laser engraving of the present invention may contain a solvent.
The solvent used in preparing the resin composition for laser engraving of the present invention is preferably mainly an aprotic organic solvent from the viewpoint of solubility of each component. More specifically, aprotic organic solvent / protic organic solvent is preferably used at 100/0 to 50/50 (weight ratio), and preferably used at 100/0 to 70/30 (weight ratio). It is more preferable to use it at 100/0 to 90/10 (weight ratio).
Preferable specific examples of the aprotic organic solvent include acetonitrile, tetrahydrofuran, dioxane, toluene, propylene glycol monomethyl ether acetate, methyl ethyl ketone, acetone, methyl isobutyl ketone, ethyl acetate, butyl acetate, ethyl lactate, N, N-dimethylacetamide. , N-methylpyrrolidone, and dimethyl sulfoxide.
Preferable specific examples of the protic organic solvent include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 1-methoxy-2-propanol, ethylene glycol, diethylene glycol, and 1,3-propanediol.
Among these, propylene glycol monomethyl ether acetate is preferable.

<Other additives>
In the resin composition for laser engraving of the present invention, additives other than the components A to F can be appropriately blended within a range that does not impair the effects of the present invention. Examples include fragrances, fillers, plasticizers, waxes, process oils, metal oxides, antiozonants, antiaging agents, thermal polymerization inhibitors, colorants, etc., and these are used alone. Alternatively, two or more kinds may be used in combination.

The resin composition for laser engraving of the present invention preferably contains a plasticizer. The plasticizer has a function of softening a film formed of the resin composition for laser engraving, and needs to be compatible with the binder polymer.
As the plasticizer, for example, dioctyl phthalate, didodecyl phthalate and the like, polyethylene glycols, polypropylene glycol (monool type and diol type), and polypropylene glycol (monool type and diol type) are preferably used.
In the resin composition for laser engraving of the present invention, it is more preferable to add nitrocellulose or a highly thermally conductive substance as an additive for improving engraving sensitivity. Since nitrocellulose is a self-reactive compound, it generates heat during laser engraving and assists in thermal decomposition of a binder polymer such as a hydrophilic polymer. As a result, it is estimated that the engraving sensitivity is improved. The highly heat conductive material is added for the purpose of assisting heat transfer, and examples of the heat conductive material include inorganic compounds such as metal particles and organic compounds such as a conductive polymer. As the metal particles, gold fine particles, silver fine particles, and copper fine particles having a particle size of micrometer order to several nanometer order are preferable. As the conductive polymer, a conjugated polymer is particularly preferable, and specific examples include polyaniline and polythiophene.
Moreover, the sensitivity at the time of photocuring the resin composition for laser engraving can be further improved by using a co-sensitizer.
Furthermore, it is preferable to add a small amount of a thermal polymerization inhibitor in order to prevent unnecessary thermal polymerization of the polymerizable compound during the production or storage of the composition.
Colorants such as dyes or pigments may be added for the purpose of coloring the resin composition for laser engraving. Thereby, properties such as the visibility of the image portion and the suitability of the image density measuring device can be improved.
Furthermore, in order to improve the physical properties of the cured film of the resin composition for laser engraving, a known additive such as a filler may be added.

(Relief printing plate precursor for laser engraving)
The first embodiment of the relief printing plate precursor for laser engraving of the present invention has a relief forming layer comprising the resin composition for laser engraving of the present invention.
Further, the second embodiment of the relief printing plate precursor for laser engraving of the present invention has a crosslinked relief forming layer obtained by crosslinking the relief forming layer comprising the resin composition for laser engraving of the present invention.
In the present invention, the “relief printing plate precursor for laser engraving” is a state in which the relief-forming layer having a crosslinkability made of the resin composition for laser engraving is in a state before being crosslinked and cured by light or heat. Both or either one.
In the present invention, the “relief-forming layer” refers to a layer in a state before being crosslinked, that is, a layer made of the resin composition for laser engraving of the present invention, and may be dried if necessary. Good.
A “relief printing plate” is produced by laser engraving a printing plate precursor having a crosslinked relief forming layer.
In the present invention, the “crosslinked relief forming layer” refers to a layer obtained by crosslinking the relief forming layer. The crosslinking can be performed by heat, and the crosslinking may be formed by light by polymerization of (Component D) polymerizable compound. The crosslinking is not particularly limited as long as the resin composition is cured, and a crosslinked structure formed by a reaction between component A and component C, a reaction between components A, a reaction between (component D) polymerizable compounds, or the like. However, it is preferable to form a cross-linked structure by reaction of Component A with other components.
In the present invention, the “relief layer” refers to a layer engraved with a laser in a relief printing plate, that is, the crosslinked relief forming layer after laser engraving.

The relief printing plate precursor for laser engraving of the present invention has a relief forming layer made of a resin composition for laser engraving containing the above components. The (crosslinked) relief forming layer is preferably provided on the support.
The relief printing plate precursor for laser engraving further has an adhesive layer between the support and the (crosslinked) relief forming layer, if necessary, and a slip coat layer and a protective film on the (crosslinked) relief forming layer. May be.

<Relief forming layer>
The relief forming layer is a layer made of the resin composition for laser engraving of the present invention, and is preferably a thermally crosslinkable layer.

  As a production mode of a relief printing plate using a relief printing plate precursor for laser engraving, a relief printing plate precursor having a crosslinked relief forming layer is obtained by crosslinking the relief forming layer, and then a crosslinked relief forming layer (hard relief forming layer) is used. It is preferable that the relief printing plate is produced by forming a relief layer by laser engraving. By crosslinking the relief forming layer, wear of the relief layer during printing can be prevented, and a relief printing plate having a relief layer having a sharp shape after laser engraving can be obtained.

The relief forming layer can be formed by molding the resin composition for laser engraving having the above-described components for the relief forming layer into a sheet shape or a sleeve shape. The relief forming layer is usually provided on a support which will be described later. However, the relief forming layer can be directly formed on the surface of a member such as a cylinder provided in an apparatus for plate making and printing, or can be arranged and fixed there. It does not necessarily require a support.
Hereinafter, the case where the relief forming layer is formed into a sheet shape will be mainly described as an example.

<Support>
The material used for the support of the relief printing plate precursor for laser engraving is not particularly limited, but materials having high dimensional stability are preferably used. For example, metals such as steel, stainless steel and aluminum, polyester (for example, PET (polyethylene terephthalate)) , Plastic resins such as PBT (polybutylene terephthalate), PAN (polyacrylonitrile)) and polyvinyl chloride, synthetic rubbers such as styrene-butadiene rubber, and plastic resins reinforced with glass fibers (such as epoxy resins and phenol resins) It is done. As the support, a PET film or a steel substrate is preferably used. The form of the support is determined depending on whether the relief forming layer is a sheet or a sleeve.

<Adhesive layer>
When the relief forming layer is formed on the support, an adhesive layer may be provided between them for the purpose of enhancing the adhesive strength between the layers.
As a material (adhesive) that can be used for the adhesive layer, for example, I.I. Those described in the edition of Skeist, “Handbook of Adhesives”, the second edition (1977) can be used.

<Protective film, slip coat layer>
For the purpose of preventing scratches or dents on the surface of the relief forming layer or the surface of the crosslinked relief forming layer, a protective film may be provided on the surface of the relief forming layer or the surface of the crosslinked relief forming layer. The thickness of the protective film is preferably 25 to 500 μm, more preferably 50 to 200 μm. As the protective film, for example, a polyester film such as PET, or a polyolefin film such as PE (polyethylene) or PP (polypropylene) can be used. The surface of the film may be matted. The protective film is preferably peelable.

  When the protective film cannot be peeled or when it is difficult to adhere to the relief forming layer, a slip coat layer may be provided between both layers. The material used for the slip coat layer is composed mainly of a resin that is soluble or dispersible in water, such as polyvinyl alcohol, polyvinyl acetate, partially saponified polyvinyl alcohol, hydroxyalkyl cellulose, alkyl cellulose, and polyamide resin, and that is less sticky. It is preferable to do.

(Manufacturing method of relief printing plate precursor for laser engraving)
The formation of the relief forming layer in the relief printing plate precursor for laser engraving is not particularly limited. The method of melt-extruding on a support body after removing a solvent is mentioned. Alternatively, the resin composition for laser engraving may be cast on a support and dried in an oven to remove the solvent from the resin composition.
Among them, the plate making method of the relief printing plate for laser engraving of the present invention includes a layer forming step for forming a relief forming layer comprising the resin composition for laser engraving of the present invention, and a crosslinked relief obtained by crosslinking the relief forming layer with heat. The production method preferably includes a crosslinking step for obtaining a relief printing plate precursor having a forming layer.

Thereafter, a protective film may be laminated on the relief forming layer as necessary. Lamination can be performed by pressure-bonding the protective film and the relief forming layer with a heated calendar roll or the like, or by bringing the protective film into close contact with the relief forming layer impregnated with a small amount of solvent on the surface.
When using a protective film, you may take the method of laminating | stacking a relief forming layer on a protective film first, and laminating a support body then.
When providing an adhesive layer, it can respond by using the support body which apply | coated the adhesive layer. When providing a slip coat layer, it can respond by using the protective film which apply | coated the slip coat layer.

<Layer formation process>
The method for producing a relief printing plate precursor for laser engraving of the present invention preferably includes a layer forming step of forming a relief forming layer comprising the resin composition for laser engraving of the present invention.
As a method for forming the relief forming layer, the resin composition for laser engraving of the present invention is prepared, and if necessary, the solvent is removed from the resin composition for laser engraving and then melt-extruded onto a support. A method of preparing the resin composition for laser engraving of the present invention, casting the resin composition for laser engraving of the present invention on a support and drying it in an oven to remove the solvent is preferably exemplified.
The resin composition for laser engraving can be produced by, for example, dissolving or dispersing Component A to Component C and optional components D to F in an appropriate solvent, and then mixing these liquids. Since most of the solvent component is preferably removed at the stage of producing the relief printing plate precursor, the solvent is a low-molecular alcohol that easily volatilizes (eg, methanol, ethanol, n-propanol, isopropanol, propylene glycol monomethyl ether). It is preferable to keep the total amount of solvent added as small as possible by adjusting the temperature.

  The thickness of the (crosslinked) relief forming layer in the relief printing plate precursor for laser engraving is preferably 0.05 mm or more and 10 mm or less, more preferably 0.05 mm or more and 7 mm or less, and more preferably 0.05 mm or more and 3 mm or less before and after crosslinking. Further preferred.

<Crosslinking process>
The method for producing a relief printing plate precursor for laser engraving of the present invention is preferably a production method including a crosslinking step for obtaining a relief printing plate precursor having a crosslinked relief forming layer obtained by crosslinking the relief forming layer with heat.
The relief forming layer can be crosslinked by heating the relief printing plate precursor for laser engraving (thermal crosslinking step). Examples of the heating means for crosslinking by heat include a method of heating the printing plate precursor in a hot air oven or a far infrared oven for a predetermined time, and a method of contacting a heated roll for a predetermined time.
By thermally crosslinking the relief forming layer, there is an advantage that, firstly, the relief formed after laser engraving becomes sharp, and secondly, the adhesiveness of engraving residue generated during laser engraving is suppressed.

Moreover, in order to form a bridge | crosslinking by polymerizing a polymeric compound using a photoinitiator etc., you may further perform bridge | crosslinking by light.
When the relief forming layer contains a photopolymerization initiator, the relief forming layer can be crosslinked by irradiating the relief forming layer with an actinic ray that triggers the photopolymerization initiator.
In general, light is applied to the entire surface of the relief forming layer. Examples of light (also referred to as “active light”) include visible light, ultraviolet light, and electron beam, and ultraviolet light is the most common. If the substrate side for immobilizing the relief forming layer, such as the support of the relief forming layer, is the back side, the surface may only be irradiated with light, but the support should be a transparent film that transmits actinic rays. For example, it is preferable to irradiate light from the back side. When the protective film exists, the irradiation from the surface may be performed while the protective film is provided, or may be performed after the protective film is peeled off. Since polymerization inhibition may occur in the presence of oxygen, actinic rays may be irradiated after the relief forming layer is covered with a vinyl chloride sheet and evacuated.

(Relief printing plate and plate making method)
The plate making method of the relief printing plate of the present invention includes a layer forming step of forming a relief forming layer comprising the resin composition for laser engraving of the present invention, a relief printing plate having a crosslinked relief forming layer obtained by crosslinking the relief forming layer with heat. It is preferable to include a crosslinking step for obtaining an original plate and an engraving step for laser engraving the relief printing plate precursor having the crosslinked relief forming layer.
The relief printing plate of the present invention is a relief printing plate having a relief layer obtained by crosslinking and laser engraving a layer made of the resin composition for laser engraving of the present invention. It is preferably a relief printing plate that has been made.
In the relief printing plate of the present invention, a water-based ink can be suitably used during printing.
The layer forming step and the cross-linking step in the plate making method of the relief printing plate of the present invention are synonymous with the layer forming step and the cross-linking step in the method for producing a relief printing plate precursor for laser engraving, and the preferred range is also the same.

<Engraving process>
The plate making method of the relief printing plate of the present invention preferably includes an engraving step of laser engraving the relief printing plate precursor having the crosslinked relief forming layer.
The engraving step is a step of forming a relief layer by laser engraving the crosslinked relief forming layer crosslinked in the crosslinking step. Specifically, it is preferable to form a relief layer by engraving a crosslinked crosslinked relief forming layer by irradiating a laser beam corresponding to a desired image. Moreover, the process of controlling a laser head with a computer based on the digital data of a desired image and carrying out scanning irradiation with respect to a bridge | crosslinking relief forming layer is mentioned preferably.
In this engraving process, an infrared laser is preferably used. When irradiated with an infrared laser, the molecules in the crosslinked relief forming layer undergo molecular vibrations and generate heat. When a high-power laser such as a carbon dioxide laser or YAG laser is used as an infrared laser, a large amount of heat is generated in the laser irradiation part, and molecules in the crosslinked relief forming layer are selectively cut by molecular cutting or ionization. That is, engraving is performed. The advantage of laser engraving is that the engraving depth can be set arbitrarily, so that the structure can be controlled three-dimensionally. For example, a portion that prints fine halftone dots can be engraved shallowly or with a shoulder so that the relief does not fall down due to printing pressure, and a portion of a groove that prints fine punched characters is engraved deeply As a result, the ink is less likely to be buried in the groove, and it is possible to suppress the crushing of the extracted characters.
In particular, when engraving with an infrared laser corresponding to the absorption wavelength of the photothermal conversion agent, the crosslinked relief forming layer can be selectively removed with higher sensitivity, and a relief layer having a sharp image can be obtained.

As the infrared laser used in the engraving process, a carbon dioxide laser (CO ₂ laser) or a semiconductor laser is preferable from the viewpoints of productivity and cost. In particular, a semiconductor infrared laser with a fiber (FC-LD) is preferably used. In general, a semiconductor laser can be downsized with high efficiency and low cost in laser oscillation compared to a CO ₂ laser. Moreover, since it is small, it is easy to form an array. Furthermore, the beam shape can be controlled by processing the fiber.
The semiconductor laser preferably has a wavelength of 700 to 1,300 nm, more preferably 800 to 1,200 nm, still more preferably 860 to 1,200 nm, and particularly preferably 900 to 1,100 nm.

Moreover, since the semiconductor laser with a fiber can output a laser beam efficiently by attaching an optical fiber, it is effective for the engraving process in the present invention. Furthermore, the beam shape can be controlled by processing the fiber. For example, the beam profile can have a top hat shape, and energy can be stably given to the plate surface. Details of the semiconductor laser are described in “Laser Handbook 2nd Edition” edited by Laser Society, “Practical Laser Technology” edited by Electronic Communication Society, and the like.
Also, a plate making apparatus equipped with a fiber-coupled semiconductor laser that can be suitably used in a method for making a relief printing plate using the relief printing plate precursor of the present invention is disclosed in JP 2009-172658 A and JP 2009-214334 A. And can be used for making a relief printing plate according to the present invention.

In the method for making a relief printing plate of the present invention, following the engraving step, the following rinsing step, drying step, and / or post-crosslinking step may be included as necessary.
Rinsing step: a step of rinsing the engraved surface of the relief layer surface after engraving with water or a liquid containing water as a main component.
Drying step: a step of drying the engraved relief layer.
Post-crosslinking step: a step of imparting energy to the relief layer after engraving and further crosslinking the relief layer.
Since the engraving residue adheres to the engraving surface after the above process, a rinsing step of rinsing the engraving residue by rinsing the engraving surface with water or a liquid containing water as a main component may be added. As a means of rinsing, there is a method of washing with tap water, a method of spraying high-pressure water, and a known batch type or conveying type brush type washing machine as a photosensitive resin relief printing machine. For example, when the engraving residue cannot be removed, a rinsing liquid to which soap or a surfactant is added may be used.
When the rinsing process for rinsing the engraving surface is performed, it is preferable to add a drying process for drying the engraved relief forming layer and volatilizing the rinsing liquid.
Furthermore, you may add the post-crosslinking process which further bridge | crosslinks a relief forming layer as needed. By performing the post-crosslinking step, which is an additional cross-linking step, the relief formed by engraving can be further strengthened.

The pH of the rinsing solution that can be used in the present invention is preferably 9 or more, more preferably 10 or more, and still more preferably 11 or more. The pH of the rinsing liquid is preferably 14 or less, more preferably 13.5 or less, still more preferably 13.2 or less, and particularly preferably 12.5 or less. Handling is easy in the said range.
What is necessary is just to adjust pH using an acid and / or a base suitably in order to make a rinse liquid into said pH range, and the acid and base to be used are not specifically limited.
The rinsing liquid that can be used in the present invention preferably contains water as a main component.
Moreover, the rinse liquid may contain water miscible solvents, such as alcohol, acetone, tetrahydrofuran, etc. as solvents other than water.

It is preferable that the rinse liquid contains a surfactant.
As the surfactant that can be used in the present invention, a carboxybetaine compound, a sulfobetaine compound, a phosphobetaine compound, an amine oxide compound, or from the viewpoint of reducing engraving residue removal and influence on the relief printing plate, Preferred are betaine compounds (amphoteric surfactants) such as phosphine oxide compounds.

Examples of the surfactant include known anionic surfactants, cationic surfactants, and nonionic surfactants. Furthermore, fluorine-based and silicone-based nonionic surfactants can be used in the same manner.
Surfactant may be used individually by 1 type, or may use 2 or more types together.
The amount of the surfactant used is not particularly limited, but is preferably 0.01 to 20% by weight and more preferably 0.05 to 10% by weight with respect to the total weight of the rinse liquid.

As described above, a relief printing plate having a relief layer on the surface of an arbitrary substrate such as a support can be obtained.
The thickness of the relief layer of the relief printing plate is preferably 0.05 mm or more and 10 mm or less, more preferably 0.05 mm or more and 7 mm, from the viewpoint of satisfying various printability such as wear resistance and ink transferability. Hereinafter, it is particularly preferably 0.05 mm or more and 3 mm or less.

The Shore A hardness of the relief layer of the relief printing plate is preferably 50 ° or more and 90 ° or less. When the Shore A hardness of the relief layer is 50 ° or more, even if the fine halftone dots formed by engraving are subjected to the strong printing pressure of the relief printing press, they do not collapse and can be printed normally. In addition, when the Shore A hardness of the relief layer is 90 ° or less, it is possible to prevent faint printing in a solid portion even in flexographic printing with a kiss touch.
Note that the Shore A hardness in this specification is quantified by pressing and deforming an indenter (called a push needle or an indenter) on the surface of the object to be measured at 25 ° C., and measuring the deformation amount (indentation depth). It is a value measured by a durometer (spring type rubber hardness meter).

  The relief printing plate of the present invention can be printed using any of water-based ink, oil-based ink, and UV ink by a relief printing press, and printing with UV ink by a flexographic printing press. Is also possible. The relief printing plate of the present invention is excellent in rinsing properties, no engraving residue remains, the obtained relief layer has excellent printing durability, and there is a concern of plastic deformation of the relief layer and deterioration of printing durability over a long period of time. There is no, and printing can be carried out.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.

Example 1
1. Preparation of resin composition for laser engraving In a three-necked flask equipped with a stirring blade and a cooling tube, (Component C) Denkabutyral # 3000-2 (polyvinyl butyral (PVB), manufactured by Denki Kagaku Kogyo Co., Ltd.) as a binder polymer ) 50 parts and 47 parts of propylene glycol monomethyl ether acetate as a solvent were heated at 70 ° C. for 2 hours with stirring to dissolve the polymer. Furthermore, (Component D) 1,6-hexanediol dimethacrylate (manufactured by Tokyo Chemical Industry Co., Ltd., 15 parts) as a polymerizable compound, (Component E) perbutyl Z (t-butyl peroxybenzoate, NOF as a polymerization initiator) 1 part of (manufactured by Co., Ltd.), 1 part of (component F) Ketjen black EC600JD (carbon black, manufactured by Lion Corporation) as a photothermal conversion agent, and (component A) silane compound S-1 (following compound (note that Et represents an ethyl group.), KBE-846, manufactured by Shin-Etsu Chemical Co., Ltd.), 15 parts, (Component B) U-CAT SA1 (1,8-diazabicyclo [5.4.0] as a thermal base generator. ] 1 part of undecene-7 (DBU) -phenol salt (manufactured by San Apro Co., Ltd.) was added and stirred for 10 minutes, and the resin composition 1 for laser engraving for a relief forming layer having fluidity was mixed with the solution. I got it.

<Evaluation of composition stability>
The “stability” of the obtained resin composition for laser engraving was evaluated as follows. When the obtained resin composition for laser engraving is further heated at 70 ° C. for 30 minutes and the viscosity change before and after heating is less than 5%, the case where it is 5% or more and less than 10% is Δ, or 10% or more. Some cases were evaluated as x.

2. Preparation of relief printing plate precursor for laser engraving A spacer (frame) of a predetermined thickness is placed on a PET substrate, and the resin composition 1 for laser engraving obtained above is gently cast to the extent that it does not flow out of the spacer (frame). Then, it was dried in an oven at 70 ° C. for 3 hours to provide a relief forming layer having a thickness of about 1 mm, thereby producing a relief printing plate precursor 1 for laser engraving.

3. Preparation of relief printing plate The relief forming layer of the obtained relief printing plate precursor 1 for laser engraving was heated at 80 ° C for 3 hours and further at 100 ° C for 3 hours to thermally crosslink the relief forming layer.
The relief forming layer after crosslinking was engraved with the following two types of lasers.
As a carbon dioxide laser engraving machine, engraving by laser irradiation was performed using a high-quality CO ₂ laser marker ML-9100 series (manufactured by Keyence Corporation). After removing the protective film from the relief printing plate precursor 1 for laser engraving, a carbon dioxide laser engraving machine is used to rasterize a 1 cm square solid part under the conditions of output: 12 W, head speed: 200 mm / second, pitch setting: 2,400 DPI Engraved.
As a semiconductor laser engraving machine, a laser recording apparatus equipped with a fiber-coupled semiconductor laser (FC-LD) SDL-6390 (JDSU, wavelength: 915 nm) having a maximum output of 8.0 W was used. A 1 cm square solid part was raster engraved with a semiconductor laser engraving machine under conditions of laser output: 7.5 W, head speed: 409 mm / second, pitch setting: 2,400 DPI.
The thickness of the relief layer of the relief printing plate was about 1 mm.
Moreover, when the Shore A hardness of the relief layer was measured by the above-mentioned measuring method, it was 75 °. In addition, the measurement of Shore hardness A was similarly performed also in each Example and comparative example which are mentioned later.

4). Evaluation of Relief Printing Plate Performance evaluation of the relief printing plate was performed on the following items, and the results are shown in Table 2.

(4-1) Engraving Depth “Engraving depth” of the relief layer obtained by laser engraving the relief forming layer of the relief printing plate precursor was measured as follows. Here, “sculpture depth” refers to the difference between the engraved position (height) and the unengraved position (height) when the cross section of the relief layer is observed. The “engraving depth” in this example was measured by observing the cross section of the relief layer with an ultra-deep color 3D shape measuring microscope VK9510 (manufactured by Keyence Corporation). A large engraving depth means high engraving sensitivity. The results are shown in Table 2 for each type of racer used for engraving.

(4-2) Rinsing property The laser-engraved plate was immersed in water, and the engraved part was rubbed 10 times with a toothbrush (manufactured by Lion Corporation, Clinica Habrush Flat). Thereafter, the presence or absence of residue on the surface of the relief layer was confirmed with an optical microscope. The case where there was no residue was marked by ◎, the case where there was almost no residue, ○, the residue where a little residue remained, Δ, and the case where residue was not removed was indicated by ×.

(4-3) Printing durability The obtained relief printing plate is set in a printing machine (ITM-4 type, manufactured by Iyo Machinery Co., Ltd.), and water-based ink Aqua SPZ16 Beni (Toyo Ink Manufacturing Co., Ltd.) (Manufactured by Nippon Paper Industries Co., Ltd., thickness: 100 μm), and printing was confirmed using 1 to 10% highlights. The end of printing was a halftone dot, and the length (meters) of paper printed up to the end of printing was used as an index. The larger the value, the better the printing durability.

(Examples 2-34 and Comparative Examples 1-6)
A resin composition for laser engraving, a relief printing plate precursor for laser engraving, and a relief printing plate were prepared in the same manner as in Example 1 except that the components A to F were changed to those shown in Table 1. It produced for 2-34 and Comparative Examples 1-6, respectively.
Moreover, the stability, engraving depth, rinse property and printing durability of the composition were evaluated by the same method as in Example 1, respectively.
Further, the Shore A hardness of the relief layer of the obtained relief printing plate was measured by the same method as in Example 1.
The evaluation results are summarized in Table 2.

The compounds indicated by the abbreviations in Table 1 other than those described above in Example 1 are as follows.
S-2 to S-4: Compounds shown below (In addition, Et represents an ethyl group and Me represents a methyl group.)
U-CAT SA102: 1,8-diazabicyclo [5.4.0] undecene-7 (DBU) -2-ethylhexylate (manufactured by San Apro Co., Ltd.)
U-CAT SA506: DBU-p-toluenesulfonate (manufactured by San Apro Co., Ltd.)
U-CAT SA603: DBU-formate (manufactured by San Apro Co., Ltd.)
U-CAT 1102: 1,5-diazabicyclo [4.3.0] nonene-5 (DBN) -2-ethylhexylate (manufactured by San Apro Co., Ltd.)
PMMA: Polymethyl methacrylate (weight average molecular weight Mw = 50,000)
TR-2000 (styrene butadiene rubber manufactured by JSR Corporation)
DCP: Compound shown below (manufactured by Shin-Nakamura Chemical Co., Ltd.)
701: Compounds shown below (manufactured by Shin-Nakamura Chemical Co., Ltd.)
NOD-N: Compound shown below (manufactured by Shin-Nakamura Chemical Co., Ltd.)
A-NOD-N: Compound shown below (manufactured by Shin-Nakamura Chemical Co., Ltd.)
A-DPH: The following compounds (manufactured by Shin-Nakamura Chemical Co., Ltd.)
Perhexa V (4,4-di (t-butylperoxy) n-butyl valerate, manufactured by NOF Corporation)
Perhexyl I (t-hexyl peroxyisopropyl monocarbonate, manufactured by NOF Corporation)
Ketjen Black: Ketjen Black EC600JD (carbon black, manufactured by Lion Corporation)
Black Pearls 2000: Carbon black (manufactured by Cabot)

Claims (21)

(Component A) a compound having a hydrolyzable silyl group and / or a silanol group;
(Component B) a thermal base generator;
(Component C) A binder polymer, and a resin composition for laser engraving.   The resin composition for laser engraving according to claim 1, wherein Component A is a compound having a total of two or more hydrolyzable silyl groups and / or silanol groups.   The resin composition for laser engraving according to claim 1 or 2, wherein the hydrolyzable silyl group in Component A is a residue in which at least one alkoxy group or halogen atom is directly bonded to a Si atom.   The resin composition for laser engraving according to any one of claims 1 to 3, wherein Component B is a salt of a base and an acid.   The resin composition for laser engraving according to claim 4, wherein the base is an amine compound.   The resin composition for laser engraving according to claim 5, wherein the amine compound is a cycloamidine compound. The resin composition for laser engraving according to claim 6, wherein the cycloamidine compound is a compound represented by the formula (1).

(M represents an integer of 2 to 6, and each R independently represents a hydrogen atom or a substituent.)   The compound represented by the formula (1) is 1,8-diazabicyclo [5.4.0] undecene-7 or 1,5-diazabicyclo [4.3.0] nonene-5. 8. The resin composition for laser engraving according to 7.   The resin composition for laser engraving according to any one of claims 4 to 8, wherein the acid is an organic acid.   The resin composition for laser engraving according to claim 9, wherein the organic acid is an organic acid selected from the group consisting of a carboxylic acid, an aromatic hydroxy compound, and an organic sulfonic acid.   The resin composition for laser engraving according to any one of claims 1 to 10, wherein Component C is at least one selected from the group consisting of an acrylic resin and polyvinyl butyral.   The resin composition for laser engraving according to claim 11, wherein Component C is polyvinyl butyral.   The resin composition for laser engraving according to claim 1, further comprising (Component D) a polymerizable compound.   The resin composition for laser engraving according to claim 1, further comprising (Component E) a polymerization initiator.   The resin composition for laser engraving according to any one of claims 1 to 14, further comprising (Component F) a photothermal conversion agent capable of absorbing light having a wavelength of 700 to 1,300 nm.   A relief printing plate precursor for laser engraving comprising a relief forming layer formed from the resin composition for laser engraving according to any one of claims 1 to 15 on a support.   A relief printing plate precursor for laser engraving, comprising a crosslinked relief-forming layer obtained by thermally crosslinking a relief-forming layer formed from the resin composition for laser engraving according to any one of claims 1 to 15 on a support.   A method for making a relief printing plate, comprising a step of laser engraving a crosslinked relief forming layer in the relief printing plate precursor according to claim 17 to form a relief layer.   A relief printing plate having a relief layer produced by the plate making method according to claim 18.   The relief printing plate according to claim 19, wherein the thickness of the relief layer is 0.05 mm or more and 10 mm or less.   The relief printing plate according to claim 19 or 20, wherein the Shore A hardness of the relief layer is from 50 ° to 90 °.