JP2012006325A - Laser-engraving resin composition, laser-engraving relief printing plate original plate and method for producing the same, and relief printing plate and plate-making method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser-engraving resin composition, securing sufficient dynamic strength or scum removal properties after engraving by effectively connecting a radical polymerization network and a sol-gel crosslinked network when hardening the laser-engraving resin composition to form the radical polymerization network and the sol-gel crosslinked network, to provide a relief printing plate original plate using the laser-engraving resin composition and a method for producing the same, to provide a plate-making method for a relief printing plate using the same, and to provide the relief printing plate obtained by the same.SOLUTION: This provided laser-engraving resin composition contains at least: (a component A) a compound having an azo group or a peroxy group, and having a hydrolyzable silyl group and/or a silanol group; (a component B) a binder polymer; and (a component C) a radically polymerizable compound. The relief printing plate original plate using the laser-engraving resin composition and the method for producing the same, the plate-making method for the relief printing plate using the same, and the relief printing plate obtained by the same are also provided.

Description

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

  Conventionally, hydrophobic laser engraving printing plates using natural rubber, synthetic rubber, thermoplastic elastomer, and the like have been used (see Patent Documents 1-3). As a technique for improving the rinsing property of engraving residue generated by laser engraving, a technology has been proposed in which porous inorganic fine particles are contained in the relief forming layer, liquid residue is adsorbed on the particle, and the removability is improved ( (See Patent Document 4). In addition, the inclusion of an organosilicon compound in a photosensitive resin composition that can be engraved with laser reduces the residue rate of engraving after engraving (it becomes difficult to attach residue), and wipes engraving residue with a cloth impregnated with an organic solvent. It is shown that it becomes easy (see Patent Document 5).

JP 11-338139 A European Patent Application No. 1936438 JP 2009-255510 A JP 2004-174758 A International Publication No. 2005/070691 Pamphlet

The method described in Patent Document 4 has a problem that the engraving shape (edge shape) is not good because it contains particles, which causes a reduction in image quality.
Moreover, in the method described in Patent Document 5, the adhesive residue is removed using an organic solvent, and it is difficult to remove the adhesive residue with an aqueous system having excellent environmental suitability.

  The object of the present invention is to effectively link each other when curing a resin composition for laser engraving to form a radical polymerization network and a sol-gel cross-linking network, and to remove sufficient mechanical strength and debris after engraving. Resin composition for laser engraving that can secure the properties, relief printing plate precursor using the resin composition for laser engraving, a method for producing the same, a method for making a relief printing plate using the same, and a relief obtained thereby To provide a print version.

The above-mentioned problems of the present invention have been solved by means described in the following <1>, <10>, <11>, <13>, <15> and <16>. It is described below together with <2> to <9>, <12>, <14> and <17> which are preferred embodiments.
<1> (Component A) A compound having an azo group or a peroxy group and having a hydrolyzable silyl group and / or a silanol group, (Component B) a binder polymer, and (Component C) a radical polymerizable compound A resin composition for laser engraving characterized by containing,
<2> The resin composition for laser engraving according to the above <1>, wherein component A is a compound represented by the following formula (A-1) or formula (A-2):

（式（Ａ−１）及び式（Ａ−２）中、Ｚはパーオキシ基又はアゾ基を表し、Ｘは加水分解性シリル基又はシラノール基を表し、Ｙ¹は（Ｌ＋１）価の連結基を表し、Ｙ²は２価の連結基を表し、Ｙ³は（ｍ＋１）価の連結基を表し、Ｙ⁴は（ｎ＋１）価の連結基を表し、Ｌ、ｍ及びｎはそれぞれ１〜３の整数を表す。）

(In Formula (A-1) and Formula (A-2), Z represents a peroxy group or an azo group, X represents a hydrolyzable silyl group or silanol group, and Y ¹ represents a (L + 1) -valent linking group. Y ² represents a divalent linking group, Y ³ represents an (m + 1) valent linking group, Y ⁴ represents an (n + 1) valent linking group, and L, m, and n each represent 1 to 3 Represents an integer.)

<3> (Component D) For laser engraving according to the above <1> or <2>, which contains a compound having a hydrolyzable silyl group and / or a silanol group, which has neither an azo group nor a peroxy group Resin composition,
<4> The resin composition for laser engraving according to <3>, wherein the ratio of component D to component A is 0 to 50 by mass ratio,
<5> The resin composition for laser engraving according to any one of the above <1> to <4>, wherein the component B contains a hydroxyl group,
<6> The resin composition for laser engraving according to <5>, wherein Component B is polyvinyl butyral or a derivative thereof,
<7> (Component E) The resin composition for laser engraving according to any one of the above <1> to <6>, further containing a photothermal conversion agent,
<8> The resin composition for laser engraving according to <7>, wherein the component E is carbon black,
<9> (Component F) The resin composition for laser engraving according to any one of the above <1> to <8>, further comprising a radical polymerization initiator having neither a hydrolyzable silyl group nor a silanol group. object,
<10> A relief printing plate precursor for laser engraving having a relief forming layer comprising the resin composition for laser engraving according to any one of <1> to <9> above,
<11> Relief printing for laser engraving having a crosslinked relief forming layer obtained by crosslinking the relief forming layer comprising the resin composition for laser engraving according to any one of <1> to <9> above by light and / or heat. Original edition,
<12> The relief printing plate precursor for laser engraving according to <11>, wherein the crosslinked relief forming layer is crosslinked by heat,
<13> A layer forming step of forming a relief forming layer comprising the resin composition for laser engraving according to any one of the above <1> to <9>, and the relief forming layer by light and / or heat A method for producing a relief printing plate precursor for laser engraving, which comprises a crosslinking step of crosslinking and obtaining a relief printing plate precursor having a crosslinked relief forming layer,
<14> The method for producing a relief printing plate precursor according to <13>, wherein the crosslinking step is a step of crosslinking the relief forming layer with heat,
<15> A layer forming step of forming a relief forming layer comprising the resin composition for laser engraving according to any one of the above <1> to <9>, the relief forming layer is crosslinked by light and / or heat. A method for making a relief printing plate comprising: a crosslinking step for obtaining a relief printing plate precursor having a crosslinked relief forming layer; and a engraving step for laser engraving the relief printing plate precursor having the crosslinked relief forming layer to form a relief layer. ,
<16> A relief printing plate having a relief layer produced by the plate making method of a relief printing plate according to <15> above,
<17> The relief printing plate according to <16>, wherein the relief layer has a thickness of 0.05 mm or more and 10 mm or less.

  According to the present invention, when the resin composition for laser engraving is cured to form a radical polymerization network and a sol-gel cross-linking network, they are effectively connected to each other, and sufficient mechanical strength and debris removal after engraving are removed. Resin composition for laser engraving that can secure the properties, relief printing plate precursor using the resin composition for laser engraving, a method for producing the same, a method for making a relief printing plate using the same, and a relief obtained thereby We were able to provide a printed version.

  Hereinafter, the present invention will be described in detail.

(Resin composition for laser engraving)
The resin composition for laser engraving of the present invention (hereinafter also simply referred to as “resin composition”) is (Component A) a compound having an azo group or a peroxy group and having a hydrolyzable silyl group and / or a silanol group. (Component B) a binder polymer and (Component C) a radically polymerizable compound.
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.

The present invention is effective in effectively connecting the resin composition for laser engraving to each other when the radical polymerization network and the sol-gel crosslinking network are formed. In the present invention, the “radical polymerization network” means a network structure formed by polymerization of a radical polymerizable compound. The “sol-gel cross-linked network” means a network structure of siloxane formed by cross-linking a compound having a hydrolyzable silyl group and / or silanol group by a sol-gel reaction.
In the present invention, the resin composition for laser engraving contains component A having an azo group or a peroxy group, which is a radical polymerization initiating group, and having a hydrolyzable silyl group and / or a silanol group. Thereby, when hardening this resin composition, a radical is generated from component A and component A and a radical polymerization network are connected. At the same time, the sol-gel reaction, which is a different curing system, proceeds via the hydrolyzable silyl group or silanol group of component A, so that the radical polymerization network and the sol- The gel crosslinking network is connected. Thus, according to the present invention, when the resin composition for laser engraving is cured to form a radical polymerization network and a sol-gel cross-linking network, they are effectively connected to each other to obtain sufficient mechanical strength and engraving. Debris removability can be ensured.
Further, when the binder polymer has a reactive group such as a hydroxyl group that reacts with a hydrolyzable silyl group and / or silanol group, component A is linked to the binder polymer by the hydrolyzable silyl group and / or silanol group. Is done. Also, as described above, component A is linked to the radical polymerization network by an azo group or a peroxy group. As a result, the binder polymer and the radical polymerization network are connected to each other via component A. Thus, according to the present invention, the binder polymer and the radical polymerization network are effectively connected to each other, so that sufficient mechanical strength and debris removal after engraving can be ensured.

The resin composition of the present invention can obtain a high-density crosslinked structure when cured as described above. Therefore, according to this invention, the resin composition for laser engraving excellent in film forming property can be obtained.
The resin composition of the present invention can be applied to a wide range of applications for forming a resin shaped article subjected to laser engraving without any particular limitation. For example, as an application mode of the resin composition of the present invention, specifically, an image forming layer of an image forming material that forms an image by laser engraving, a relief forming layer of a printing plate precursor that forms a convex relief by laser engraving , Intaglio, stencil, stamp, and the like, but are not limited thereto. The resin composition of the present invention can be particularly suitably used for an image forming layer of an image forming material for forming an image by laser engraving and a relief forming layer in a relief printing plate precursor for laser engraving.

In this specification, regarding the explanation of the relief printing plate precursor, it contains a binder polymer (component B or the like), is a flat surface layer as an image forming layer to be subjected to laser engraving, and is uncrosslinked crosslinkable. The 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. Further, “(Component A) a compound having an azo group or a peroxy group and having a hydrolyzable silyl group and / or a silanol group” or the like is also referred to as “Component A” or the like as appropriate.
Hereinafter, the components of the resin composition for laser engraving will be described.

<(Component A) Compound having azo group or peroxy group and having hydrolyzable silyl group and / or silanol group>
The resin composition for laser engraving of the present invention contains (Component A) a compound having an azo group or a peroxy group and having a hydrolyzable silyl group and / or a silanol group. Hereinafter, although preferable component A is explained in full detail, this invention is not restrict | limited by these description.

  In the present invention, component A is preferably a compound represented by the following formula (A-1) or formula (A-2).

In the formula (A-1) and the formula (A-2), Z represents a peroxy group or an azo group.
In the formula (A-1) and the formula (A-2), X represents a hydrolyzable silyl group or a silanol group. The “hydrolyzable silyl group” represented by X is a silyl group having hydrolyzability, and examples of the hydrolyzable group include alkoxy groups, mercapto groups, halogen atoms, amide groups, acetoxy groups, amino groups. 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 (A-3).

In the formula (A-3), at least one of R ^{1 to} R ³ is selected from the group consisting of an alkoxy group, a mercapto group, a halogen atom, an amide group, an acetoxy group, an amino group, and an isopropenoxy group. Represents a hydrolyzable group or a hydroxyl group. The remaining R ^{1 to} R ³ are each independently a hydrogen atom, a halogen atom, or a monovalent organic substituent (for example, an alkyl group, an aryl group, an alkenyl group, an alkynyl group, and an aralkyl group can be exemplified). To express. As the alkyl group, a methyl group, an ethyl group, and an (iso) propyl group are preferable, and a methyl group and an ethyl group are more preferable. As the aryl group, a phenyl group is preferable.
In the formula (A-3), the hydrolyzable group bonded to the silicon atom is particularly preferably an alkoxy group or a halogen atom, and more preferably an alkoxy group.
As an alkoxy group, a C1-C30 alkoxy group is preferable from a viewpoint of rinse property and printing durability. More preferably, it is a C1-C15 alkoxy group, More preferably, it is C1-C5, Most preferably, it is a C1-C3 alkoxy group, Most preferably, it is a methoxy group or an ethoxy group.
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. is there.

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

In Formula (A-1) and Formula (A-2), Y ¹ represents an (L + 1) -valent linking group, Y ² represents a divalent linking group, and Y ³ represents an (m + 1) -valent linking group. Y ⁴ represents a (n + 1) -valent linking group. These linking groups include aliphatic groups, aromatic groups, heterocyclic groups, and —O—, —S—, —NH—, —N <, —CO—, —C (═N —) —, —SO—, It is preferably —SO ₂ —, a hydrogen atom, or a combination thereof. More preferably, these linking groups include —O—, —S—, —NH—, —N <, and —CO—.
L, m and n are each an integer of 1 to 3.
Hereinafter, compounds (1) to (12) are shown as specific examples of component A, but the present invention is not limited thereto. In the following, Me represents a methyl group, Et represents an ethyl group, and Pr represents a propyl group.

There is no restriction | limiting in particular as the synthesis | combining method of component A, It can synthesize | combine by a well-known method.
For example, the above compounds (1) to (10) are an addition reaction, a substitution reaction, or a commercially available azo compound having a terminal reactive group such as an amino group or a hydroxyl group with an epoxy group, an alkyl halide, or a compound having a hydroxyl group. It can be synthesized by a condensation reaction. It can also be obtained by converting a hydrazine moiety such as a dialkylhydrazine compound into an azo group by an oxidation reaction with hypochlorous acid, for example. However, the synthesis method of the polyfunctional organic azo compound that can be used as the component A of the present invention is not limited to the above.
For example, per (substituted) benzoic acid such as the above-mentioned compounds (11) and (12) can be obtained from L. S. Silbert, E.M. Siegel, D.M. Swern, J. et al. Org. Chem. , 27, 1336 (1962) and J.A. R. Moyer, N.M. C. Manley, J.M. Org. Chem. 29, 2099 (1964) and the like. However, the synthesis method of the polyfunctional organic peroxide that can be used as the component A of the present invention is not limited to the above.

  The content of Component A contained in the resin composition of the present invention is 0.01 to 20% by mass in the total solid content from the viewpoint of satisfying the balance between the mechanical strength of the coating film and the residue removal property. Is preferable, more preferably 0.05 to 10% by mass, and particularly preferably 0.1 to 4% by mass.

<(Component B) Binder polymer>
The resin composition for laser engraving of the present invention contains (Component B) a binder polymer.
The binder polymer is a polymer component contained in the resin composition for laser engraving, and a general polymer compound can be appropriately selected and used alone or in combination of two or more. 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.

  The binder polymer preferably has a hydroxyl group. When the binder polymer has a hydroxyl group, a crosslinked structure with the component A having a hydrolyzable silyl group and / or silanol group and the component D described later can be effectively formed.

  As binder polymer, polystyrene resin, polyester resin, polyamide resin, polyurea polyamideimide resin, polyurethane resin, polysulfone resin, polyethersulfone resin, polyimide resin, polycarbonate resin, hydrophilic polymer containing hydroxyethylene unit, 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. As the thermoplastic elastomer, those described in detail in paragraphs 0039 to 0040 of JP-A-2008-163081 can be used. 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 and 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.

  Moreover, polyesters comprising hydroxyl carboxylic acid units such as polylactic acid can be preferably used. Specific examples of such polyesters include polyhydroxyalkanoate (PHA), lactic acid-based polymer, polyglycolic acid (PGA), polycaprolactone (PCL), poly (butylene succinic acid), and derivatives or mixtures thereof. Those selected from the group consisting of

Furthermore, a polymer containing a hydroxyethylene unit can also be preferably used. As the hydrophilic polymer containing a hydroxyethylene unit, polyvinyl alcohol (PVA) and its derivatives are preferably used.
Examples of PVA derivatives include acid-modified PVA in which at least part of the hydroxyl group of the hydroxyethylene unit is modified to an acid group such as a carboxyl group, modified PVA in which part of the hydroxyl group is modified to a (meth) acryloyl group, at least of the hydroxyl group Modified PVA partially modified with an amino group, modified PVA introduced with ethylene glycol, propylene glycol and their multimers into at least a part of the hydroxyl group, polyvinyl acetal obtained by treating polyvinyl alcohol with aldehydes, etc. Is mentioned. Among these, polyvinyl acetal is particularly preferably used. As aldehydes used for the acetal treatment, acetaldehyde and butyraldehyde are preferably used because they are easy to handle. In particular, polyvinyl butyral is a PVA derivative that is preferably used. The structure of the polyvinyl butyral derivative is as shown below, and includes these structural units.

上記式中、ｌ、ｍ及びｎは上記式中のそれぞれの繰返し単位のポリビニルブチラール中における含有量（モル％）を表し、ｌ＋ｍ＋ｎ＝１００の関係を満たす。ポリビニルブチラール及びその誘導体中のブチラール含量（上記式中におけるｌの値）は、３０〜９０モル％が好ましく、４０〜８５モル％がより好ましく、４５〜７８モル％が特に好ましい。
彫刻感度と皮膜性とのバランスの観点から、ポリビニルブチラール及びその誘導体の重量平均分子量は、５，０００〜８００，０００が好ましく、８，０００〜５００，０００がより好ましく、彫刻カスのリンス性向上の観点からは、５０，０００〜３００，０００が特に好ましい。

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 (KS)” manufactured by Sekisui Chemical from the viewpoint of alcohol solubility (particularly ethanol). The series “Denka Butyral” made by Denka can be mentioned. More preferably, from the viewpoint of alcohol solubility (particularly ethanol), “S-Lec B” series made by Sekisui Chemical and “Denka Butyral” made by Denka, and more preferably “BL-1”, In "BL-1H", "BL-2", "BL-5", "BL-S", "BX-L", "BM-S", "BH-S", Denka's "Denka Butyral"“# 3000-1”, “# 3000-2”, “# 3000-4”, “# 4000-2”, “# 6000-C”, “# 6000-EP”, “# 6000-CS”, “ # 6000-AS ".
When forming a relief forming layer using the PVB derivative as the (B-1) 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 surface of the membrane.

As the acrylic resin that can be used as the binder polymer, any acrylic resin that is obtained using a known acrylic monomer and has a hydroxyl group in the molecule can be used.
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.
The content of Component B contained in the resin composition of the present invention is 2 to 95% by mass in the total solid content from the viewpoint of satisfying a good balance of form retention, water resistance and engraving sensitivity of the coating film. Is preferable, more preferably 5 to 80% by mass, and still more preferably 10 to 60% by mass.

<(Component C) radical polymerizable compound>
In the present invention, from the viewpoint of more 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 C) a radical polymerizable compound (hereinafter simply referred to as “ It is also preferable to contain a “polymerizable compound”.
The polymerizable compound can be arbitrarily selected from compounds having at least 1, preferably 2 or more, more preferably 2 to 6 ethylenically unsaturated groups.

  Hereinafter, a monofunctional polymerizable compound having one ethylenically unsaturated group in the molecule and a polyfunctional polymerizable compound having two or more of the same group in the molecule will be described.

Examples of radically polymerizable ethylenically unsaturated compounds include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid and their salts, and anhydrides having an ethylenically unsaturated group. Polymers such as products, (meth) acrylates, (meth) acrylamides, acrylonitrile, styrene, various unsaturated polyesters, unsaturated polyethers, unsaturated polyamides, unsaturated urethanes.
The (meth) acrylate represents acrylate or methacrylate, and (meth) acrylamide represents acrylamide or methacrylamide.

  Monofunctional polymerizable compounds include methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, butoxyethyl acrylate, carbitol acrylate, cyclohexyl acrylate, benzyl acrylate, N-methylol acrylamide, epoxy Acrylic acid derivatives such as acrylate, methacrylic derivatives such as methyl methacrylate, N-vinyl compounds such as N-vinylpyrrolidone and N-vinylcaprolactam, and derivatives of allyl compounds such as allyl glycidyl ether, diallyl phthalate and triallyl trimellitate. Can be mentioned.

  Polyfunctional polymerizable compounds include ethylene glycol diacrylate, triethylene glycol diacrylate, propylene glycol diacrylate, triethylene glycol dimethacrylate, 1,3-butanediol diitaconate, pentaerythritol dicrotonate, sorbitol tetramaleate , Polyhydric alcohol compounds such as methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, or ester compounds or amide compounds of polyvalent amine compounds and unsaturated carboxylic acids, and JP-A 51-37193 Urethane acrylates such as those described in JP-A-48-64183, JP-B-49-43191, and JP-B-52-30490. Can be mentioned resins and (meth) polyfunctional acrylates or methacrylates such as epoxy acrylates obtained by reacting an acrylic acid. Furthermore, the Japan Adhesion Association Vol. 20, no. 7, 300-308 (1984); Shinzo Yamashita, “Cross-linking agent handbook” (1981, Taiseisha); Kato Kiyomi, “UV / EB curing handbook (raw material)” (1985, Takashi Molecular Publications); Radtech Study Group, “Application and Market of UV / EB Curing Technology”, 79 pages (1989, CMC); Eiichiro Takiyama, “Polyester Resin Handbook”, (1988, Nikkan Kogyo) Commercially available products as described in Shimbunsha etc., or radically polymerizable or crosslinkable monomers and oligomers known in the industry can be used.

  Since the relief forming layer according to the present invention preferably has a crosslinked structure in the film, a polyfunctional polymerizable compound is preferably used. The molecular weight of these polyfunctional polymerizable compounds is preferably 200 to 2,000.

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 an engraving sensitivity improvement, it has two or more ethylenically unsaturated groups especially, and connects between two ethylenically unsaturated groups 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. , Functional groups containing dithiocarbamate or thiourea.

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, but engraving sensitivity and solubility in a coating solvent. From the viewpoint of balance, 1 to 10 is preferable, 1 to 5 is more preferable, and 1 to 2 is still more preferable.
On the other hand, the number of ethylenically unsaturated sites 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.
Examples of the sulfur-containing polyfunctional monomer include compounds described in paragraphs 0107 to 0130 of JP 2010-100048 A.

  The sulfur-containing polyfunctional monomer in the present invention is a reaction between a sulfur atom-containing dicarboxylic acid and an epoxy group-containing (meth) acrylate, a reaction between a sulfur atom-containing diol and an isocyanate-containing (meth) acrylate, a dithiol and an isocyanate-containing (meth) acrylate. It is possible to synthesize the compound by using a reaction with a diisothiocyanate and a hydroxy group-containing (meth) acrylate, a known esterification reaction, or the like. Moreover, you may use a commercial item.

  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.
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 total content of component C including the sulfur-containing polyfunctional monomer contained in the resin composition of the present invention is 10 to 60% by mass with respect to the nonvolatile component from the viewpoint of flexibility and brittleness of the crosslinked film. Is preferable, and the range of 15-45 mass% is more preferable.
In addition, when using together a sulfur-containing polyfunctional monomer and another polymeric compound, 5 mass% or more is preferable and, as for the quantity of the sulfur-containing polyfunctional monomer in all the polymeric compounds, 10 mass% or more is more preferable.

<(Component D) Compound having no azo group or peroxy group and having hydrolyzable silyl group and / or silanol group>
The resin composition for laser engraving of the present invention preferably contains (Component D) a compound having neither an azo group nor a peroxy group and having a hydrolyzable silyl group and / or a silanol group. The “hydrolyzable silyl group” in Component D is a hydrolyzable silyl group. Examples of the hydrolyzable group include an alkoxy group, a mercapto group, a halogen atom, an amide group, an acetoxy group, an amino group, An isopropenoxy group etc. can be mentioned. 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), at least one of R ^{1 to} R ³ is a water selected from the group consisting of an alkoxy group, a mercapto group, a halogen atom, an amide group, an acetoxy group, an amino group, and an isopropenoxy group. It represents a decomposable group or a hydroxyl group. The remaining R ^{1 to} R ³ are each independently a hydrogen atom, a halogen atom, or a monovalent organic substituent (for example, an alkyl group, an aryl group, an alkenyl group, an alkynyl group, and an aralkyl group can be exemplified). To express.
In the formula (1), the hydrolyzable group bonded to the silicon atom is particularly preferably an alkoxy group or a halogen atom, and more preferably an alkoxy group.
As an alkoxy group, a C1-C30 alkoxy group is preferable from a viewpoint of rinse property and printing durability. More preferably, it is a C1-C15 alkoxy group, More preferably, it is C1-C5, Most preferably, it is a C1-C3 alkoxy group, Most preferably, it is a methoxy group or an ethoxy group.
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. is there.

Component D in the present invention is preferably a compound having one or more groups represented by the formula (1), more preferably a compound having two or more. In particular, a compound having two or more hydrolyzable silyl groups is preferably used. That is, a compound having two or more silicon atoms having a hydrolyzable group bonded in the molecule is preferably used. The number of silicon atoms bonded to the hydrolyzable group contained in Component D 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 4, and the total number of hydrolyzable groups in the formula (1) is preferably in the range of 2 or 3. In particular, it is preferable that three hydrolyzable groups are bonded to a 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 preferable alkoxy groups include methoxy, ethoxy, propoxy, isopropoxy, butoxy, tert-butoxy, phenoxy, and benzyloxy. A plurality of these alkoxy groups may be used in combination, or a plurality of different alkoxy groups may be used in combination.
Examples of the alkoxysilyl group to which the alkoxy group is bonded include, for example, a trialkoxysilyl group such as a trimethoxysilyl group, a triethoxysilyl group, a triisopropoxysilyl group, a triphenoxysilyl group; a dimethoxymethylsilyl group, a diethoxymethylsilyl group And dialkoxymonoalkylsilyl groups such as methoxydimethylsilyl group and ethoxydimethylsilyl group.

Component D preferably has at least a sulfur atom, an ester bond, a urethane bond, an ether bond, a urea bond, or an imino group.
Among them, the component D preferably contains a sulfur atom from the viewpoint of crosslinkability, and from the viewpoint of engraving residue removal (rinse), an ester bond, urethane bond, or It preferably contains an ether bond (particularly an ether bond contained in an oxyalkylene group). The component D containing a sulfur atom functions as a vulcanizing agent or a vulcanization accelerator during the vulcanization treatment, and accelerates the reaction (crosslinking) of the polymer containing the conjugated diene monomer unit. As a result, the rubber elasticity necessary for the printing plate is developed. Further, the strength of the crosslinked relief forming layer and the relief layer is improved.
Moreover, it is preferable that the component D in this invention is a compound which does not have an ethylenically unsaturated group.

Component D in the present invention includes a compound in which a plurality of groups represented by the formula (1) are bonded via a divalent linking group. Such a divalent linking group includes From the viewpoint, a linking group having a sulfide group (—S—), an imino group (—N (R) —), or a urethane bond (—OCON (R) — or —N (R) COO—) is preferable. R represents a hydrogen atom or a substituent. Examples of the substituent in R include an alkyl group, an aryl group, an alkenyl group, an alkynyl group, and an aralkyl group.
There is no restriction | limiting in particular as a synthesis method of the component D, It can synthesize | combine by a well-known method. As an example, a typical synthesis method of component D including a linking group having the above specific structure is shown below.

<Synthesis Method of Component D Having Sulfide Group as Linking Group>
The method for synthesizing component D having a sulfide group as a linking group (hereinafter, appropriately referred to as “sulfide linking group-containing component D”) is not particularly limited, and specifically includes, for example, a halogenated hydrocarbon group. Reaction of component D and alkali sulfide, reaction of component D having mercapto group and halogenated hydrocarbon, reaction of component D having mercapto group and component D having halogenated hydrocarbon group, component D having halogenated hydrocarbon group Reaction of a component D having an ethylenically unsaturated double bond with a mercaptan, reaction of a component D having an ethylenically unsaturated double bond and a component D having a mercapto group, an ethylenically unsaturated double bond Reaction of a compound having a bond with a component D having a mercapto group, reaction of a ketone with a component D having a mercapto group, a diazonium salt and a mercapto group Reaction of component D having component, component D having mercapto group and oxirane, reaction of component D having mercapto group and component D having oxirane group, reaction of component D having mercaptan and oxirane group, mercapto Examples thereof include a synthesis method such as a reaction between a component D having a group and aziridines.

<Synthesis Method of Component D Having Imino Group as Linking Group>
The synthesis method of component D having an imino group as a linking group (hereinafter, referred to as “imino linking group-containing component D” as appropriate) is not particularly limited. Specifically, for example, component D having an amino group and Reaction of halogenated hydrocarbon, reaction of component D having amino group and component D having halogenated hydrocarbon group, reaction of component D having halogenated hydrocarbon group and amine, component D having amino group and oxirane Reaction of component D having amino group and component D having oxirane group, reaction of amines and component D having oxirane group, reaction of component D having amino group and aziridines, ethylenically unsaturated Reaction of component D having a heavy bond with amines, reaction of component D having ethylenically unsaturated double bond and component D having amino group, compound having ethylenically unsaturated double bond Reaction of component D having an mino group, reaction of a compound having an acetylenic unsaturated triple bond and component D having an amino group, reaction of component D having an imine unsaturated double bond and an organic alkali metal compound, iminity Examples of the synthesis method include a reaction between Component D having a saturated double bond and an organic alkaline earth metal compound, and a reaction between Component D having a carbonyl compound and an amino group.

<Synthesis method of component D having urethane bond (ureylene group) as linking group>
The synthesis method of component D having a ureylene group as a linking group (hereinafter, appropriately referred to as “ureylene linking group-containing component D”) is not particularly limited. Specifically, for example, component D having an amino group and Examples of the synthesis method include a reaction of isocyanate esters, a reaction of component D having an amino group and component D having an isocyanate ester, and a reaction of component D having an amine and isocyanate ester.

  Component D is preferably a compound represented by the following formula (D-1) or formula (D-2).

（式（Ｄ−１）及び式（Ｄ−２）中、Ｒ^Bはエステル結合、アミド結合、ウレタン結合、ウレア結合、又は、イミノ基を表し、Ｌ¹はｎ価の連結基を表し、Ｌ²は二価の連結基を表し、Ｌ^s1はｍ価の連結基を表し、Ｌ³は二価の連結基を表し、ｎ及びｍはそれぞれ独立に１以上の整数を表し、Ｒ¹〜Ｒ³はそれぞれ独立に水素原子、ハロゲン原子、又は、一価の有機置換基を表す。ただし、Ｒ¹〜Ｒ³の少なくともいずれか１つは、アルコキシ基、メルカプト基、ハロゲン原子、アミド基、アセトキシ基、アミノ基、及び、イソプロペノキシ基よりなる群から選択される加水分解性基、又は、ヒドロキシル基を表す。）

(In Formula (D-1) and Formula (D-2), R ^B represents an ester bond, an amide bond, a urethane bond, a urea bond, or an imino group, L ¹ represents an n-valent linking group, and L ² represents a divalent linking group, L ^s1 represents an m-valent linking group, L ³ represents a divalent linking group, n and m each independently represents an integer of 1 or more, R ^{1 to} R ³ each independently represents a hydrogen atom, a halogen atom, or a monovalent organic substituent, provided that at least one of R ^{1 to} R ³ is an alkoxy group, a mercapto group, a halogen atom, an amide group, an acetoxy group Represents a hydrolyzable group selected from the group consisting of a group, an amino group, and an isopropenoxy group, or a hydroxyl group.)

R ¹ to R ³ in Formula (D-1) and Formula (D-2) has the same meaning as R ¹ to R ³ in Formula (1), and preferred ranges are also the same.
Wherein R ^B is, from the viewpoint of rinsing properties and film strength, it is preferable that an ester bond or a urethane bond, and more preferably an ester bond.
The divalent or n-valent linking group in L ^{1 to} L ³ is a group composed of at least one atom selected from the group consisting of a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom and a sulfur atom. It is preferably a group composed of at least one atom selected from the group consisting of carbon atom, hydrogen atom, oxygen atom and sulfur atom. The number of carbon atoms of L ^{1 to} L ³ is preferably 2 to 60, and more preferably 2 to 30. L ³ preferably does not contain an ester bond, an amide bond, a urethane bond, a urea bond, or an imino group.
The m-valent linking group in L ^s1 is a group composed of a sulfur atom and at least one atom selected from the group consisting of a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom and a sulfur atom. Are preferable, and an alkylene group or a group in which two or more alkylene groups, sulfide groups, and imino groups are combined is more preferable. The carbon number of L ^s1 is preferably 2 to 60, and more preferably 6 to 30.
N and m are each independently preferably an integer of 1 to 10, more preferably an integer of 2 to 10, still more preferably an integer of 2 to 6, and particularly preferably 2. preferable.
The n-valent linking group of L ¹ and / or the divalent linking group of L ² or the divalent linking group of L ³ must have an ether bond from the viewpoint of sculpture residue removal (rinse). It is more preferable to have an ether bond contained in the oxyalkylene group.
Among the compounds represented by formula (D-1) or formula (D-2), from the viewpoint of crosslinkability and the like, in formula (D-1), an n-valent linking group of L ¹ and / or L ² The divalent linking group is preferably a group having a sulfur atom.

  Specific examples of component D that can be applied to the present invention are shown below. For example, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxy Silane, γ-glycidoxypropyltriethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, p-styryltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacrylic Roxypropyltriethoxysilane, γ-acryloxypropyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropylmethyldimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxy Silane, N- (β-aminoethyl) -γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercapto Propyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, mercaptomethyltrimethoxysilane, dimethoxy-3-mercaptopropylmethylsilane, 2- (2-aminoethylthioethyl) diethoxymethylsilane, 3- (2-acetoxyethyl) Thiopropyl) dimethoxymethylsilane, 2- (2-aminoethylthioethyl) triethoxysilane, dimethoxymethyl-3- (3-phenoxypropylthiopropyl) silane, bis (triethoxysilylpropyl) disulfide, bis (tri Toxisilylpropyl) 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-ureidopropyltriethoxysilane, trimethylsilanol, Examples thereof include diphenylsilanediol and triphenylsilanol. In addition, the compounds shown below are preferred, but the present invention is not 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 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 D can be obtained by appropriately synthesizing, but it is preferable from the viewpoint of cost to use a commercially available product. Examples of component D 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 for the resin composition of the present invention according to the purpose.

As component D in the present invention, a partial hydrolysis condensate obtained by using one kind of a compound having a hydrolyzable silyl group and / or silanol group, or a partial cohydrolysis condensate obtained by using two or more kinds Can be used. Hereinafter, these compounds may be referred to as “partial (co) hydrolysis condensates”.
Among silane compounds as partial (co) hydrolysis condensate precursors, from the viewpoint of versatility, cost, and film compatibility, it has a substituent selected from a methyl group and a phenyl group as a substituent on silicon. It is preferably a silane compound, specifically, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane. 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 2 to 50-mer, more preferably 2 to 30-mer, and a partial cohydrolysis condensate using two or more silane compounds as raw materials. It is also possible to use it.

  In addition, as such a partial (co) hydrolysis condensate, you may use what is marketed as a silicone alkoxy oligomer (for example, it is marketed from Shin-Etsu Chemical Co., Ltd.), etc. You may use what was manufactured by removing by-products, such as alcohol and hydrochloric acid, after making the hydrolysis water of less than an equivalent react with a hydrolysable silane compound based on a conventional method. 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 D in the resin composition of the present invention may be used alone or in combination of two or more.
The content of the component D contained in the resin composition of the present invention is preferably in the range of 0.1 to 80% by mass, more preferably in the range of 1 to 40% by mass in terms of solid content. Most preferably, it is the range of 5-30 mass%.
The ratio of component D to component A (component D) / (component A) is a mass ratio, preferably 0 to 50, more preferably 1 to 50, still more preferably 1 to 20, Preferably it is 2-10. The preservability of a resin composition can be improved as the ratio with respect to the said component A of the component D is 50 or less. Further, when the ratio of the component D to the component A is 1 or more, the effect of improving the film strength and removing engraving residue by the component A can be sufficiently obtained.

<(Component E) photothermal conversion agent>
The resin composition for laser engraving of the present invention preferably contains (Component E) a photothermal conversion agent. The photothermal conversion agent is considered to promote thermal decomposition of the cured product of the resin composition for laser engraving of the present invention by absorbing laser light and generating heat. Therefore, it is preferable to select a photothermal conversion agent that absorbs light having a laser wavelength used for engraving.

When a laser (YAG laser, semiconductor laser, fiber laser, surface emitting laser, etc.) emitting an infrared ray with a wavelength of 700 to 1,300 nm is used as a light source for laser engraving, it absorbs maximum at 700 to 1,300 nm as a photothermal conversion agent. It is preferable to use a compound having a wavelength.
Various dyes or pigments are used as the photothermal conversion agent 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. Specific examples include those having a maximum absorption wavelength at 700 to 1,300 nm, such as azo dyes, metal complex azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, diimmonium compounds, and quinoneimine dyes. , Methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, and metal thiolate complexes. Examples of the dye preferably used in the present invention include cyanine dyes such as heptamethine cyanine dye, oxonol dyes such as pentamethine oxonol dye, phthalocyanine dyes, and paragraphs 0254 to 0265 and 0270 of JP2010-069763A. ˜0272 can be mentioned.

  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 In addition, quinophthalone pigments, dyed lake pigments, azine pigments, nitroso pigments, nitro pigments, natural pigments, fluorescent pigments, inorganic pigments, carbon black, and the like can be used. Among these pigments, carbon black is preferable.

  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 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 (from 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, more preferably 500 m ² / g or more. The DBP number is preferably 200 m ² / g or more, more 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 ( Akzo), Princex (registered trademark) XE (Degussa) or Black Pearls (registered trademark) 2000 (Cabot), and Ketjen Black (Lion) are commercially available. is there.

  The content of the photothermal conversion agent in the resin composition for laser engraving varies greatly depending on the molecular extinction coefficient inherent to the molecule, but is in the range of 0.01 to 20% by mass of the total solid content of the resin composition. Is more preferable, more preferably 0.05 to 10% by mass, and still more preferably 0.1 to 5% by mass.

<(Component F) Radical polymerization initiator having neither hydrolyzable silyl group nor silanol group>
The resin composition for laser engraving of the present invention may contain (Component F) a radical polymerization initiator (hereinafter also simply referred to as “polymerization initiator”) having neither a hydrolyzable silyl group nor a silanol group. preferable.
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.

  As the (a) aromatic ketones to (l) azo compound, compounds described in JP 2010-67963 A, paragraphs 0198 to 0249 can be preferably used.

Preferred examples of the radical polymerization initiator in the present invention include the above-mentioned (a) aromatic ketones, (b) onium salt compounds, (c) organic peroxides, (e) hexaarylbiimidazole compounds, (i) Examples include metallocene compounds, (k) compounds having a carbon halogen bond, and (l) azo compounds, and (c) organic peroxides and (l) azo compounds are more preferred.
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- (tertiarybutylperoxycarbonyl) benzophenone, 3 , 3′4,4′-tetra- (tertiary amyl peroxycarbonyl) benzophenone, 3,3′4,4′-tetra- (tertiary hexylperoxycarbonyl) benzophenone, 3,3′4,4′- Tetra- (tertiary octylperoxycarbonyl) benzophenone, 3,3'4,4'-tetra- (cumylperoxycarbonyl) benzophenone, 3,3'4,4'-tetra- (p-isopropylcumylperoxycarbonyl) ) Peroxide esters such as benzophenone and di-tertiary butyl diperoxyisophthalate 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-methylpropionamide) Oxime), 2,2′-azobis [2- (2-imidazolin-2-yl) propane], 2,2′-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) -2- Hydro Ethyl] 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.

Component F in the present invention may be used alone or in combination of two or more.
Content of the component F contained in the resin composition of this invention becomes like this. Preferably it is 0.01-10 mass% with respect to the total solid of this resin composition, More preferably, it is 0.1-3 mass% It is.

<Other additives>
In the resin composition for laser engraving of the present invention, various known additives can be appropriately blended as long as the effects of the present invention are not impaired. Examples include fillers, fragrances, plasticizers, waxes, process oils, organic acids, metal oxides, antiozonants, antiaging agents, thermal polymerization inhibitors, colorants, and the like. You may use, and may use 2 or more types together.

(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” means that the relief-forming layer having a crosslinkability made of the resin composition for laser engraving is cured by light and / or heat before being crosslinked. It refers to both or either state.
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.
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 light and / or heat, and thermal crosslinking is preferable. The crosslinking is not particularly limited as long as the resin composition is cured. The reaction between the radical polymerizable compounds of component C, the reaction of component C and component A, the binder polymer of component B and component A and It is also a concept including a cross-linked structure formed by a reaction between the component D and a compound containing a silyl group, a reaction between the component A and the component D, or the like.
A “relief printing plate” is produced by laser engraving a printing plate precursor having a crosslinked relief forming layer.
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 a crosslinkable layer. As the relief printing plate precursor for laser engraving of the present invention, in addition to the crosslinked structure of component A and component D, it further contains a radically polymerizable compound of component C and a polymerization initiator of component F, thereby providing further crosslinking properties. What has the relief forming layer which provided the function is preferable.

  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. In addition, for laser engraving produced by applying a crosslinkable resin composition for laser engraving and curing from the back surface (opposite to laser engraving surface, including cylindrical ones) with light or heat In the relief printing plate precursor, the support is not necessarily required because the back side of the cured resin composition for laser engraving functions as a support.

<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 a resin that can be dissolved or dispersed in water, such as polyvinyl alcohol, polyvinyl acetate, partially saponified polyvinyl alcohol, hydroxyalkyl cellulose, alkyl cellulose, polyamide resin, etc. It is preferable that

(Manufacturing method of relief printing plate precursor for laser engraving)
Formation of the relief forming layer in the relief printing plate precursor for laser engraving is not particularly limited. For example, a resin composition for laser engraving is prepared, and if necessary, from this coating solution composition for laser engraving. 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 of forming a relief forming layer comprising the resin composition for laser engraving of the present invention, and crosslinking by the relief forming layer light and / or heat. And a crosslinking step for obtaining a relief printing plate precursor having a crosslinked relief-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 plate making method of the relief printing plate 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.
In the resin composition for laser engraving, for example, component A, component B, and optional component D, component E, fragrance, and plasticizer are dissolved in an appropriate solvent, and then component C and component F are dissolved. Can be manufactured. Since most of the solvent components need to be removed at the stage of producing the relief printing plate precursor, the solvent may be a low-boiling solvent that easily volatilizes (for example, ethanol, n-propanol, isopropanol, propylene glycol monomethyl ether, cyclohexanone, It is preferable to keep the total amount of solvent added as low as possible by using methyl ethyl ketone) or the like and adjusting the drying 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 a production method comprising a crosslinking step of obtaining a relief printing plate precursor having a crosslinked relief forming layer by crosslinking the relief forming layer with light and / or heat. Is preferred.
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, irradiation with actinic rays may be performed after the relief forming layer is covered with a vinyl chloride sheet and evacuated.

  When the relief forming layer contains a thermal polymerization initiator (the above-mentioned photopolymerization initiator can also be a thermal polymerization initiator), the relief forming layer is heated by heating the relief printing plate precursor for laser engraving. It can be crosslinked (step of crosslinking by heat). Examples of the heating means 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 the heated roll for a predetermined time.

As a method for crosslinking the relief forming layer, thermal crosslinking is preferred from the viewpoint that the relief forming layer can be uniformly cured (crosslinked) from the surface to the inside.
By crosslinking the relief forming layer, there is an advantage that the relief formed first after laser engraving becomes sharp, and second, the adhesiveness of engraving residue generated during laser engraving is suppressed. When an uncrosslinked relief-forming layer is laser engraved, unintended portions are likely to melt and deform due to residual heat that has propagated around the laser-irradiated portion, and a sharp relief layer may not be obtained. In addition, as a general property of a material, a material having a low molecular weight tends to be liquid rather than solid, that is, the adhesiveness tends to be strong. The engraving residue generated when engraving the relief forming layer tends to become more tacky as more low-molecular materials are used. Since the polymerizable compound which is a low molecule becomes a polymer by crosslinking, the generated engraving residue tends to be less tacky.

When the crosslinking step is a step of crosslinking by light, an apparatus for irradiating actinic rays is relatively expensive. Absent.
When the cross-linking step is a step of cross-linking by heat, there is an advantage that an extra expensive apparatus is not required, but since the printing plate precursor becomes high temperature, the thermoplastic polymer that becomes flexible at high temperature is not heated. The raw materials to be used must be carefully selected, such as the possibility of deformation.
In the case of thermal crosslinking, it is preferable to add a thermal polymerization initiator. As the thermal polymerization initiator, it can be used as a commercial thermal polymerization initiator for free radical polymerization. Examples of such a thermal polymerization initiator include a compound containing a suitable peroxide, hydroperoxide, or azo group. Representative vulcanizing agents can also be used for crosslinking. Thermal crosslinking can also be performed by adding a heat-curable resin, such as an epoxy resin, to the layer as a crosslinking component.

(Relief printing plate and plate making method)
The plate making method of the relief printing plate of the present invention comprises a layer forming step of forming a relief forming layer comprising the resin composition for laser engraving of the present invention, the relief forming layer is crosslinked by light and / or heat, and a crosslinked relief forming layer is formed. It is preferable to include a cross-linking step for obtaining a relief printing plate precursor having the above and a engraving step for laser engraving the relief printing plate precursor having the cross-linking 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 the Laser Society, practical laser technology, and the Institute of Electronic Communication.
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. Moreover, it is preferable that the pH of a rinse liquid is 14 or less, It is more preferable that it is 13 or less, It is still more preferable that it is 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. Further, 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.
Although the usage-amount of surfactant does not need to specifically limit, it is preferable that it is 0.01-20 mass% with respect to the total mass of a rinse liquid, and it is more preferable that it is 0.05-10 mass%.

As described above, the relief printing plate of the present invention having a relief layer on a support is 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 from the viewpoint of satisfying various flexographic printing aptitudes such as abrasion resistance and ink transferability. 7 mm or less, particularly preferably 0.05 mm or more and 0.3 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.
The Shore A hardness in the present specification is a durometer (spring type) in which an indenter (called a push needle or indenter) is pushed and deformed on the surface of the object to be measured, and the amount of deformation (pushing depth) is measured and digitized. It is a value measured by a rubber hardness meter.

  The relief printing plate produced by the method of the present invention can be printed with oil-based ink or UV ink by a letterpress printing machine, and can also be printed with UV ink by a flexographic printing machine.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.
In addition, the weight average molecular weight (Mw) of the polymer in an Example is displaying the value measured by GPC method unless there is particular notice. Further, “parts” in the following description means “parts by mass” unless otherwise specified.

Example 1
1. Preparation of crosslinkable resin composition for laser engraving In a three-necked flask equipped with a stirring blade and a cooling tube, “Denkabutyral # 3000-2” (manufactured by Denki Kagaku Kogyo Co., Ltd., polyvinyl butyral derivative, Mw) = 90,000) 50 parts and 47 parts of propylene glycol monomethyl ether acetate as a solvent were added and heated at 70 ° C. for 120 minutes with stirring to dissolve the polymer. Thereafter, the solution was brought to 40 ° C., 2 parts of compound (3) shown as a specific example of component A, 15 parts of monomer M-1 shown below as component C (polyfunctional), and component C (monofunctional) ) 8 parts of Bremer LMA (manufactured by NOF Corporation), 1.6 parts of perbutyl Z (manufactured by NOF Corporation) as component F, and Ketjen black EC600JD (carbon black, Lion Corporation) as component E 1 part) was added and stirred for 30 minutes. Thereafter, 15 parts of Compound S-1 (trade name, available from Shin-Etsu Chemical Co., Ltd. as KBE-846) shown below as Component D, and phosphoric acid (manufactured by Wako Pure Chemical Industries, Ltd.) as a catalyst 0.4 part was added and it stirred at 40 degreeC for 10 minute (s). By this operation, a fluid crosslinkable resin composition for laser engraving was obtained.

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 crosslinkable resin composition for laser engraving obtained above is gently flowed so as not to 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 to prepare a relief printing plate precursor for laser engraving.

3. Preparation of relief printing plate The relief forming layer of the obtained original plate 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 a semiconductor laser engraving machine. As the 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 The performance of the relief printing plate was evaluated in the following items, and the results are shown in Table 1.

(4-1) Rinsability (removability of residue)
The laser-engraved plate was immersed in water, and the engraved part was rubbed 10 times with a toothbrush (Lion Corporation, Clinica Habrush Flat). Then, the presence or absence of debris 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 ×.

(4-2) Film strength (mechanical strength)
After thermal crosslinking, the crosslinked relief forming layer (thickness 0.9 mm) peeled off from the PET film is punched out using a dumbbell defined in JIS K 62533, and a crosslinked relief is formed by punching only a spring (max 1,000 g). The tip of one side of the layer was hooked, the tip of the other side was pulled by hand, and the value of the load of only the spring when the crosslinked relief forming layer broke was measured. Using the measured load value at break, the sheet strength (film strength) was determined by the following equation. If the film strength is 6 N / cm or more, it is at a level that causes no practical problems.
(Sheet strength [N / cm]) = (Load at break [kg] × 9.8 [m / s ² ]) / 0.5 [cm]

(Examples 2-5 and Comparative Examples 1-5)
A resin composition for laser engraving, a relief printing plate precursor for laser engraving, and a relief were produced in the same manner as in Example 1 except that component A and / or component B used in Example 1 were changed as described below. Printing plates were obtained for Examples 2-5 and Comparative Examples 1-5, respectively. The performance evaluation was performed in the same manner as in Example 1, and the results are shown in Table 1.
In Example 2, Compound (3) of Component A used in Example 1 was changed to Compound (10) shown as a specific example of Component A.
In Example 3, the compound (3) of component A used in Example 1 was changed to the compound (11) shown as a specific example of component A.
In Example 4, Denkabutyral # 3000-2 of Component B used in Example 1 was replaced with acrylic resin: cyclohexyl methacrylate / 2-hydroxyethyl methacrylate copolymer (copolymerization ratio 70/30 (mol%), Mw). = 50,000).
In Example 5, Denkabutyral # 3000-2 of Component B used in Example 1 was replaced with 50/50 (mol%) polyaddition resin of polyurethane resin: tolylene diisocyanate / polypropylene glycol (average molecular weight 2,000). (Mw = 90,000).
In Comparative Example 1, the component A compound (3) used in Example 1 was not added.
In Comparative Example 2, the compound (3) of Component A used in Example 1 was changed to [3- (trimethoxysilyl) propyl] methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.).
In Comparative Example 3, the compound (3) of Component A used in Example 1 was changed to [3- (trimethoxysilyl) propyl] acrylate (manufactured by Tokyo Chemical Industry Co., Ltd.).
In Comparative Example 4, the compound (3) of Component A used in Example 1 was not added, and Denkabutyral # 3000-2 of Component B was replaced with an acrylic resin: cyclohexyl methacrylate / 2-hydroxyethyl methacrylate copolymer (copolymer The polymerization ratio was changed to 70/30 (mol%), Mw = 50,000).
In Comparative Example 5, the compound (3) of Component A used in Example 1 was not added, and Denkabutyral # 3000-2 of Component B was replaced with polyurethane resin: tolylene diisocyanate / polypropylene glycol (average molecular weight of 2,000). The polyaddition resin (Mw = 90,000) was changed to 50/50 (mol%).

  As shown in Table 1, the relief printing plates of Examples 1 to 5 prepared using the resin composition for laser engraving containing component A were rinsed as compared with the relief printing plates of Comparative Examples 1 to 5. It can be seen that it has excellent properties and high productivity during plate making. Moreover, it turns out that it is excellent in film | membrane strength and sufficient mechanical strength is ensured compared with the crosslinked relief forming layer of Comparative Examples 1-5 of the crosslinked relief forming layer of Examples 1-5.

Claims (17)

(Component A) a compound having an azo group or a peroxy group and having a hydrolyzable silyl group and / or a silanol group,
(Component B) a binder polymer, and
A resin composition for laser engraving, comprising at least (Component C) a radically polymerizable compound. The resin composition for laser engraving according to claim 1, wherein Component A is a compound represented by the following Formula (A-1) or Formula (A-2).

(In Formula (A-1) and Formula (A-2), Z represents a peroxy group or an azo group, X represents a hydrolyzable silyl group or silanol group, and Y ¹ represents a (L + 1) -valent linking group. Y ² represents a divalent linking group, Y ³ represents an (m + 1) valent linking group, Y ⁴ represents an (n + 1) valent linking group, and L, m, and n each represent 1 to 3 Represents an integer.)   (Component D) The resin composition for laser engraving according to claim 1 or 2, comprising a compound having neither an azo group nor a peroxy group and having a hydrolyzable silyl group and / or a silanol group.   The resin composition for laser engraving according to claim 3, wherein the ratio of component D to component A is 0 to 50 in terms of mass ratio.   The resin composition for laser engraving according to claim 1, wherein Component B contains a hydroxyl group.   The resin composition for laser engraving according to claim 5, wherein Component B is polyvinyl butyral or a derivative thereof.   The resin composition for laser engraving according to claim 1, further comprising (Component E) a photothermal conversion agent.   The resin composition for laser engraving according to claim 7, wherein Component E is carbon black.   (Component F) The resin composition for laser engraving according to any one of claims 1 to 8, further comprising a radical polymerization initiator having neither a hydrolyzable silyl group nor a silanol group.   A relief printing plate precursor for laser engraving, comprising a relief forming layer comprising the resin composition for laser engraving according to any one of claims 1 to 9.   A relief printing plate precursor for laser engraving, comprising a crosslinked relief forming layer obtained by crosslinking the relief forming layer comprising the resin composition for laser engraving according to any one of claims 1 to 9 with light and / or heat.   The relief printing plate precursor for laser engraving according to claim 11, wherein the crosslinked relief forming layer is crosslinked by heat. A layer forming step of forming a relief forming layer comprising the resin composition for laser engraving according to any one of claims 1 to 9, and
A method for producing a relief printing plate precursor for laser engraving, comprising: a crosslinking step of crosslinking the relief forming layer with light and / or heat to obtain a relief printing plate precursor having a crosslinked relief forming layer.   The method for producing a relief printing plate precursor according to claim 13, wherein the crosslinking step is a step of crosslinking the relief forming layer with heat. A layer forming step of forming a relief forming layer comprising the resin composition for laser engraving according to any one of claims 1 to 9,
A crosslinking step of crosslinking the relief forming layer with light and / or heat to obtain a relief printing plate precursor having a crosslinked relief forming layer; and
A method for making a relief printing plate, comprising: engraving a relief printing plate precursor having the crosslinked relief forming layer by laser engraving to form a relief layer.   The relief printing plate which has a relief layer manufactured by the plate-making method of the relief printing plate of Claim 15.   The relief printing plate according to claim 16, wherein the thickness of the relief layer is 0.05 mm or more and 10 mm or less.