JP2011046090A - Rinse liquid for making relief printing plate and method for making relief printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide rinse liquid for making a relief printing plate which can easily remove scum on a plate produced at the time of engraving and can suppress bad smell in a plate-making work environment and to provide a method for making the relief printing plate. <P>SOLUTION: The rinse liquid for making the relief printing plate includes a compound having a deodorization ability. Preferably the compound having the deodorization ability is polyphenols and/or cyclic oligosaccharides. It is preferable that the compound having the deodorization ability is contained by 0.01 to 10 wt.% to total weight of the rinse liquid. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rinsing liquid for relief printing plate making and a method for making a relief printing plate.

  As a method of forming a printing plate by forming irregularities on the photosensitive resin layer laminated on the support surface, the relief forming layer formed using the photosensitive composition is exposed to ultraviolet light through the original film. A method of selectively curing an image portion and removing an uncured portion with a developer, so-called “analog plate making” is well known.

  The relief printing plate is a relief printing plate having a relief layer having irregularities, and the relief layer having such irregularities includes, for example, an elastomeric polymer such as synthetic rubber, a resin such as a thermoplastic resin, Alternatively, it is obtained by patterning a relief forming layer containing a photosensitive composition containing a mixture of a resin and a plasticizer to form irregularities. Of such relief printing plates, those having a soft relief layer are sometimes referred to as flexographic plates.

  When producing a relief printing plate by analog plate making, since an original image film using a silver salt material is generally required, the production time and cost of the original image film are required. Furthermore, since chemical processing is required for development of the original image film and processing of the development waste liquid is also required, a simpler plate preparation method, for example, a method that does not use the original image film, and development processing are required. The method of not doing is examined.

In recent years, a method of making a relief forming layer by scanning exposure without requiring an original film has been studied.
As a technique that does not require an original film, a relief printing plate precursor having a laser-sensitive mask layer element capable of forming an image mask on a relief forming layer has been proposed (see, for example, Patent Documents 1 and 2). . According to these plate making methods, since an image mask having the same function as the original film is formed from the mask layer element by laser irradiation based on the image data, it is referred to as “mask CTP method”. A film is not necessary, but the subsequent plate making process is a process of exposing with ultraviolet light through an image mask to develop and remove an uncured portion, and there is still room for improvement in that a development process is required.

  Many so-called “direct engraving CTP methods” in which a relief forming layer is directly engraved with a laser to make a plate as a plate making method that does not require a development step have been proposed. The direct engraving CTP method literally engraves with a laser to form reliefs, and has the advantage that the relief shape can be freely controlled, unlike the relief formation using the original film. For this reason, when an image such as a letter is formed, the area is engraved deeper than other areas, or the fine halftone dot image is engraved with a shoulder in consideration of resistance to printing pressure, etc. Is also possible.

When a hydrophobic polymer or elastomer (rubber) is used as the binder polymer that constitutes the relief forming layer, the water resistance is good, so the resistance to water-based inks during printing is high, but the relief formation contains a hydrophobic binder polymer. When the layer is laser engraved, the residue produced by engraving is a sticky liquid and often makes it difficult to perform a simple rinsing operation with tap water.
As a technique for improving the rinsing property of debris after engraving, a technique has been proposed in which porous inorganic fine particles are contained in the relief forming layer, liquid debris is adsorbed on the particles, and the removability is improved (for example, Patent Documents). 3).

  Further, for example, Patent Document 4 discloses a flexographic printing plate precursor capable of laser engraving or a flexographic printing plate obtained by laser engraving. In these documents, a monomer is mixed with an elastomeric rubber as a binder, the mixture is cured by a thermal polymerization mechanism or a photopolymerization mechanism, and then laser engraving is performed to obtain a flexographic printing plate. There is a problem that an unpleasant odor such as scorching is generated.

  As a technique for suppressing an unpleasant odor generated when subjected to laser engraving, for example, a polymer composition containing 45% by mass or more of ethylene units as a repeating unit and an organic peroxide is crosslinked. A flexographic printing plate comprising a polymer material for laser processing thus formed has been proposed (for example, see Patent Document 5).

  As described above, at present, the technology that can suppress the unpleasant odor generated at the time of laser engraving is not sufficiently provided. In particular, a technique relating to suppression of unpleasant odor in a rinsing process generally performed after a laser engraving process is not provided.

JP 2004-262135 A JP 2001-121833 A JP 2004-174758 A JP 2006-2061 A Japanese Patent Laid-Open No. 2002-3665

  An object of the present invention is to provide a rinsing liquid for relief printing plate making that can easily remove debris on the plate generated during engraving and can suppress odor in the plate making work environment, and a plate making method for the relief printing plate. Is to provide.

The above-described problems of the present invention have been solved by means described in the following <1> and <12>. It is described below together with <2> to <11> which are preferred embodiments.
<1> A rinsing liquid for relief printing plate making, comprising a compound having deodorizing ability,
<2> The rinsing liquid for relief printing plate making according to <1>, wherein the compound having deodorizing ability includes polyphenols,
<3> The rinsing liquid for relief printing plate making according to <2>, wherein the polyphenol contains a catechol residue and / or a pyrogallol residue,
<4> The rinsing liquid for relief printing plate making according to <2> or <3>, wherein the polyphenol is catechin and / or a derivative thereof,
<5> The rinsing liquid for relief printing plate making according to any one of <1> to <4>, wherein the compound having deodorizing ability includes a cyclic oligosaccharide,
<6> The rinsing liquid for relief printing plate making according to <5>, wherein the cyclic oligosaccharide is cyclodextrin,
<7> The relief printing plate making plate according to any one of <1> to <6>, wherein the compound having deodorizing ability is contained in an amount of 0.01% by weight to 10% by weight based on the total weight of the rinse liquid. Rinse solution,
<8> The relief printing plate making according to any one of <1> to <7>, wherein the compound having the deodorizing ability is contained in an amount of 0.1% by weight or more and 1% by weight or less based on the total weight of the rinsing liquid. Rinse solution,
<9> The rinsing liquid for relief printing plate making according to any one of <1> to <8>, wherein the pH of the rinsing liquid is 8 or more,
<10> The rinsing liquid for relief printing plate making according to any one of <1> to <9>, wherein the water-miscible solvent is contained in an amount of 0.1% by weight to 10% by weight with respect to the total weight of the rinsing liquid. ,
<11> The rinsing liquid for relief printing plate making according to <10>, wherein the water-miscible solvent is alcohol,
<12> A step of preparing a relief printing plate precursor having a relief forming layer, a step of engraving the relief printing plate precursor by exposure, and a step of removing engraving residue generated by engraving with a rinse liquid in this order The rinsing liquid is the rinsing liquid for relief printing plate making described in any one of <1> to <11>.

  According to the present invention, there are provided a rinsing liquid for relief printing plate making that can easily remove scum on a plate generated during engraving and can suppress odor in a plate making work environment, and a plate making method for a relief printing plate. Could be provided.

Hereinafter, the present invention will be described in detail.
In the following description, the description of “A to B” representing a numerical range means “A or more and B or less” unless otherwise specified. That is, a numerical range including A and B which are end points is represented.

(Rinse for relief printing plate making)
The rinsing liquid for relief printing plate making of the present invention (hereinafter also simply referred to as “rinsing liquid”) contains a compound having a deodorizing ability (hereinafter also referred to as “deodorant”).
<Deodorant>
The deodorant used in the present invention is not particularly limited. For example, “Latest deodorant and deodorization technology” (Industry Technology Association), “Development and commercialization of new deodorant industrial deodorant. Compounds described in "Approach of" (Technical Information Association).
In the present invention, from the viewpoint of availability and versatility, the deodorant compound (deodorant) is phenols, diphenols, polyphenols, hydroquinones, diarylamines, alkylated p-phenylenediamine. , Dihydroquinones, thioethers, hindered amines, phosphites, phosphonites, thioethers, and polysaccharides. Among these, polyphenols and / or polysaccharides are more preferable, and polyphenols and / or cyclic oligosaccharides are more preferable.
Furthermore, the deodorant that can be used in the present invention is preferably a natural extract component.
Examples of natural extract components include catechins, epigallocatechins, gallocatechins, epicatechin gallates, epigallocatechin galades, gallotannins, and ellagitannins, which are extracts from plants such as catechins and tannins, and rosemary, Examples include sunflower seeds, fresh coffee, tea, grape skins, grape seeds, extracts from natural products such as apples, and those containing enzymes that oxidize phenolic compounds. In addition, polysaccharides typified by chitosan or the like, or plant extract components typified by hinoki oil, docami extract, orange essential oil and the like are also preferred.

In the present invention, as described above, polyphenols are preferably used as the deodorant.
Moreover, as said polyphenol, catechin and tannin which are flavonoids are more preferable. Specific examples include catechin, epigallocatechin, gallocatechin, epicatechin gallate, epigallocatechin galade, gallotannin, and ellagitannin, and catechin, epicatechin gallate, and gallotannin are more preferable.

  As the deodorant, a compound having a phenolic hydroxyl group is preferably used. Among compounds having a phenolic hydroxyl group, those having a plurality of phenolic hydroxyl groups are preferred. In particular, a compound having 2 to 10 phenolic hydroxyl groups in one molecule is preferably used, and a compound having a catechol group and / or a pyrogallol group (more preferably a galloyl group) is more preferable. Further, catechins having a flavan skeleton are preferably used, and catechins having 5 to 10 hydroxyl groups are preferably used.

  Specific examples of preferable compounds as compounds having deodorizing ability are listed below, but the present invention is not limited to these.

なお、上記の化学式において、対イオンは省略しており、対イオンとしては、Ｃｌ^-が例示できる。

In the above formulas, counterion is omitted, as counterions, Cl ^- can be exemplified.

The compound having a deodorizing ability used in the present invention preferably contains polyphenols in terms of a high deodorizing effect.
Here, “polyphenols” in the present invention refers to a compound having a plurality of phenolic hydroxyl groups, and not only a compound having a plurality of aromatic rings having a hydroxyl group, but also a compound having a plurality of hydroxyl groups on the same aromatic ring. Including.

In particular, polyphenols are preferably compounds having at least one of a catechol group and a pyrogallol group, and catechins and / or catechin derivatives are preferred.
The catechin derivatives are represented by (+)-catechin, epicatechin, gallocatechin, epigallocatechin, epigallocatechin gallate, etc., and OH is present in the aromatic ring or aliphatic cyclic ether ring in the structure with a flavan structure as a basic skeleton. Introduced compounds and compounds in which these OH are further modified with a substituent are mentioned.

  Moreover, in this invention, it is also preferable that a deodorizer contains cyclic oligosaccharide from a viewpoint which has high deodorizing ability. Although it does not specifically limit as cyclic oligosaccharide, It is preferable that it is a cyclodextrin. Cyclodextrin is a cyclic oligosaccharide having a cyclic structure in which D-glucose is bound by α (1 → 4) glucoside bonds, and α-cyclodextrin (cyclohexaamylose), β-cyclodextrin (cycloheptaamylose), γ -Cyclodextrin (cyclooctaamylose) is exemplified.

  In the rinsing solution of the present invention, the deodorizing compound may be used alone or in combination of a plurality of types.

  The amount of the deodorizing compound added to the rinsing liquid includes all of the rinsing liquid from the viewpoints of the odor reduction effect, the solubility of the rinsing liquid in water used as a solvent, and the ability to remove residue on the plate. It is preferably 0.01% to 10% by weight, more preferably 0.1% to 5% by weight, and further preferably 0.1% to 1% by weight. preferable. In addition, when using 2 or more types of compounds which have deodorizing ability, it is preferable to make it total into said addition amount.

<PH of rinse solution>
The pH of the rinse liquid is preferably 8 or higher, more preferably pH 10 or higher, and further preferably pH 11 or higher. Moreover, it is preferable that the pH of a rinse liquid is 14 or less, More preferably, it is 13 or less, More preferably, it is 12.5 or less.
It is preferable that the pH of the rinsing liquid is 8 or more because sufficient rinsing properties (cleaning properties) can be obtained. Moreover, since pH is 12.5 or less and handling is easy, it is especially preferable.

What is necessary is just to adjust pH using an acid (acidic compound) and a base (basic compound) 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 basic compound for adjusting pH is not particularly limited, and a known basic compound can be used, but an inorganic basic compound is preferable, and an alkali metal salt compound and an alkaline earth metal salt are preferable. A compound is more preferable, and an alkali metal hydroxide is more preferable.
Examples of basic compounds include sodium hydroxide, ammonium, potassium, lithium, sodium silicate, potassium, tribasic sodium phosphate, potassium, ammonium, dibasic sodium phosphate, potassium, Examples include inorganic alkali salts such as ammonium, sodium carbonate, potassium, ammonium, sodium hydrogen carbonate, potassium, ammonium, sodium borate, potassium, and ammonium.
Further, when an acid is used for adjusting the pH, inorganic acids are preferred, for example, HCl, H ₂ SO _3, phosphoric acid, HNO ₃ is illustrated.

<Surfactant>
It is preferable that the rinse liquid contains a surfactant.
There is no restriction | limiting in particular as surfactant, A well-known surfactant can be used, Anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant etc. can be illustrated.
Anionic surfactants include fatty acid salts, abietic acid salts, hydroxyalkane sulfonates, alkane sulfonates, α-olefin sulfonates, dialkyl sulfosuccinates, alkyl diphenyl ether disulfonates, linear alkyl benzene sulfonates, Branched alkyl benzene sulfonates, alkyl naphthalene sulfonates, alkylphenoxy polyoxyethylene propyl sulfonates, polyoxyethylene alkyl sulfophenyl ether salts, N-methyl-N-oleyl taurine sodium, N-alkyl sulfosuccinic acid monoamides Sodium salts, petroleum sulfonates, sulfated castor oil, sulfated beef tallow oil, fatty acid alkyl ester sulfate esters, alkyl sulfate esters, polio Siethylene alkyl ether sulfates, fatty acid monoglyceride sulfates, polyoxyethylene alkylphenyl ether sulfates, polyoxyethylene styrylphenyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, polyoxy Examples thereof include ethylene alkylphenyl ether phosphate esters, partially saponified products of styrene-maleic anhydride copolymers, partially saponified products of olefin-maleic anhydride copolymers, naphthalene sulfonate formalin condensates, and the like.

Examples of the cationic surfactant include alkylamine salts and quaternary ammonium salts.
Nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene polystyryl phenyl ether, polyoxyethylene polyoxypropylene alkyl ether, glycerin fatty acid partial esters, sorbitan fatty acid partial esters , Pentaerythritol fatty acid partial esters, propylene glycol mono fatty acid esters, sucrose fatty acid partial esters, polyoxyethylene sorbitan fatty acid partial esters, polyoxyethylene sorbitol fatty acid partial esters, polyethylene glycol fatty acid esters, polyglycerin fatty acid partial esters , Fatty acid diethanolamides, N, N-bis-2-hydroxyalkylamines, polyoxyethylene alkyl Min, triethanolamine fatty acid esters, trialkylamine oxides, molecular weight of polypropylene glycol 200 to 5,000, trimethylolpropane, adduct of glycerin or sorbitol polyoxyethylene or polyoxypropylene, acetylene glycol, and the like.

Examples of amphoteric surfactants include carboxybetaine compounds, sulfobetaine compounds, phosphobetaine compounds, amine oxide compounds, or phosphine oxide compounds.
Fluorine-based and silicone-based nonionic surfactants can also be used in the same manner.
Surfactant may be used individually by 1 type, or may use 2 or more types together.
The amount of the surfactant used is not particularly limited, but is preferably 0.01 to 20% by weight, more preferably 0.05 to 10% by weight, based on the total weight of the rinse liquid. .

  In the present invention, in particular, the amphoteric surfactant represented by the following formula (1) (compound represented by formula (1)) and / or the amphoteric surfactant represented by formula (2) (formula (2) It is preferable to include a compound represented by Among these, it is preferable to contain at least an amphoteric surfactant represented by the formula (1) (a compound represented by the formula (1)).

（式（１）中、Ｒ¹〜Ｒ³はそれぞれ独立に、一価の有機基を表し、Ｒ⁴は単結合、又は、二価の連結基を表し、ＡはＰＯ（ＯＲ⁵）Ｏ^-、ＯＰＯ（ＯＲ⁵）Ｏ^-、Ｏ^-、ＣＯＯ^-、又は、ＳＯ₃ ^-を表し、Ｒ⁵は、水素原子、又は、一価の有機基を表し、Ｒ¹〜Ｒ³のうち２つ以上の基が互いに結合し環を形成してもよい。）

(In formula (1), R ^{1 to} R ³ each independently represents a monovalent organic group, R ⁴ represents a single bond or a divalent linking group, and A represents PO (OR ⁵ ) O ^−. , OPO (OR ⁵ ) O ⁻ , O ⁻ , COO ⁻ , or SO ₃ ⁻ , R ⁵ represents a hydrogen atom or a monovalent organic group, and two or more of R ^{1 to} R ³ May be bonded to each other to form a ring.)

（式（２）中、Ｒ⁶〜Ｒ⁸はそれぞれ独立に、一価の有機基を表し、Ｒ⁹は単結合、又は、二価の連結基を表し、ＢはＰＯ（ＯＲ¹⁰）Ｏ^-、ＯＰＯ（ＯＲ¹⁰）Ｏ^-、Ｏ^-、ＣＯＯ^-、又は、ＳＯ₃ ^-を表し、Ｒ¹⁰は、水素原子、又は、一価の有機基を表し、Ｒ⁶〜Ｒ⁸のうち２つ以上の基が互いに結合し環を形成してもよい。）

(In formula (2), R ^{6 to} R ⁸ each independently represents a monovalent organic group, R ⁹ represents a single bond or a divalent linking group, and B represents PO (OR ¹⁰ ) O ^−. , OPO (OR ¹⁰ ) O ⁻ , O ⁻ , COO ⁻ , or SO ₃ ⁻ , R ¹⁰ represents a hydrogen atom or a monovalent organic group, and two or more of R ^{6 to} R ⁸ May be bonded to each other to form a ring.)

In the present invention, the rinsing liquid for relief printing plate making may be a compound represented by the formula (1) and / or a compound represented by the formula (2), which may be used alone or in combination of two or more. However, it is preferable to contain at least the compound represented by the formula (1).
The compound represented by the formula (1) or the compound represented by the formula (2) is preferably a carboxybetaine compound, a sulfobetaine compound, a phosphobetaine compound, an amine oxide compound, or a phosphine oxide compound. In the present invention, N = O amine oxide compound, and, each structure of the phosphine oxide compound P = O ^{is, N + -O -, P +} -O - shall be regarded as.
R ^{1 to} R ³ in the formula (1) each independently represent a monovalent organic group. Moreover, although two or more groups among R ^{1 to} R ³ may be bonded to each other to form a ring, it is preferable that no ring is formed.
The monovalent organic group in R ^{1 to} R ³ is not particularly limited, but an alkyl group, an alkyl group having a hydroxy group, an alkyl group having an amide bond in the alkyl chain, or an ether bond in the alkyl chain. The alkyl group is preferably an alkyl group, an alkyl group having a hydroxy group, or an alkyl group having an amide bond in the alkyl chain.
In addition, the alkyl group in the monovalent organic group may be linear, branched or have a ring structure.
Further, it is particularly preferable that two of R ^{1 to} R ³ are methyl groups, that is, the compound represented by the formula (1) has an N, N-dimethyl structure. With the above structure, particularly good rinsing properties are exhibited.

R ⁴ in the formula (1) represents a single bond or a divalent linking group, and is a single bond when the compound represented by the formula (1) is an amine oxide compound.
The divalent linking group in R ⁴ is not particularly limited, but is preferably an alkylene group or an alkylene group having a hydroxy group, and is an alkylene group having 1 to 8 carbon atoms or a carbon having a hydroxy group. It is more preferably an alkylene group having 1 to 8 carbon atoms, and further preferably an alkylene group having 1 to 3 carbon atoms or an alkylene group having 1 to 3 carbon atoms having a hydroxy group.
A in the formula (1) represents PO (OR ⁵ ) O ⁻ , OPO (OR ⁵ ) O ⁻ , O ⁻ , COO ⁻ , or SO ₃ ^−, and represents O ⁻ , COO ⁻ , or SO ₃ ^−. is preferably, COO ^- is more preferable.
When A ⁻ is O ⁻ , R ⁴ is preferably a single bond.
R ⁵ in PO (OR ⁵ ) O ⁻ and OPO (OR ⁵ ) O ⁻ represents a hydrogen atom or a monovalent organic group, and is a hydrogen atom or an alkyl group having one or more unsaturated fatty acid ester structures. It is preferable that
R ⁴ is preferably a group having no PO (OR ⁵ ) O ⁻ , OPO (OR ⁵ ) O ⁻ , O ⁻ , COO ⁻ , and SO ₃ ⁻ .

R ^{6 to} R ⁸ in the formula (2) each independently represent a monovalent organic group. Moreover, although two or more groups among R ^{6 to} R ⁸ may be bonded to each other to form a ring, it is preferable that no ring is formed.
The monovalent organic group in R ^{6 to} R ⁸ is not particularly limited, but is preferably an alkyl group, an alkenyl group, an aryl group, or a hydroxy group, and is preferably an alkenyl group, an aryl group, or a hydroxy group. More preferably.
In addition, the alkyl group in the monovalent organic group may be linear, branched or have a ring structure.
Moreover, it is particularly preferable that two of R ^{6 to} R ⁸ are aryl groups.

R ⁹ in the formula (2) represents a single bond or a divalent linking group, and is a single bond when the compound represented by the formula (2) is a phosphine oxide compound.
The divalent linking group for R ⁹ is not particularly limited, but is preferably an alkylene group or an alkylene group having a hydroxy group, and is an alkylene group having 1 to 8 carbon atoms or a carbon having a hydroxy group. It is more preferably an alkylene group having 1 to 8 carbon atoms, and further preferably an alkylene group having 1 to 3 carbon atoms or an alkylene group having 1 to 3 carbon atoms having a hydroxy group.
B in the formula (2) represents PO (OR ¹⁰ ) O ⁻ , OPO (OR ¹⁰ ) O ⁻ , O ⁻ , COO ⁻ , or SO ₃ ^−, and is preferably O ⁻ .
When B ⁻ is O ⁻ , R ⁹ is preferably a single bond.
R ¹⁰ in PO (OR ¹⁰ ) O 2 ^— and OPO (OR ¹⁰ ) O 2 ^— represents a hydrogen atom or a monovalent organic group, and represents a hydrogen atom or an alkyl group having one or more unsaturated fatty acid ester structures. It is preferable that
R ⁹ is preferably a group having no PO (OR ¹⁰ ) O ⁻ , OPO (OR ¹⁰ ) O ⁻ , O ⁻ , COO ⁻ , and SO ₃ ⁻ .

  The compound represented by the formula (1) is preferably a compound represented by the following formula (3).

（式（３）中、Ｒ¹は一価の有機基を表し、Ｒ⁴は単結合、又は、二価の連結基を表し、ＡはＰＯ（ＯＲ⁵）Ｏ^-、ＯＰＯ（ＯＲ⁵）Ｏ^-、Ｏ^-、ＣＯＯ^-、又は、ＳＯ₃ ^-を表し、Ｒ⁵は、水素原子、又は、一価の有機基を表す。）

(In Formula (3), R ¹ represents a monovalent organic group, R ⁴ represents a single bond or a divalent linking group, and A represents PO (OR ⁵ ) O ⁻ , OPO (OR ⁵ ) O. ^-, O -, COO ^-, or SO ₃ ^- represents, R ⁵ represents a hydrogen atom, or a monovalent organic group).

Equation (3) in R ^1, A and, R ⁵ is, R ^1, A in Formula (1), and has the same meaning as R ^5, a preferred range is also the same.

  The compound represented by the formula (2) is preferably a compound represented by the following formula (4).

（式（４）中、Ｒ⁶〜Ｒ⁸はそれぞれ独立に、アルキル基、アルケニル基、アリール基、又は、ヒドロキシ基を表す。ただし、Ｒ⁶〜Ｒ⁸の全てが同じ基となることはない。）

(In the formula (4), R ^{6 to} R ⁸ each independently represents an alkyl group, an alkenyl group, an aryl group, or a hydroxy group. However, all of R ^{6 to} R ⁸ do not become the same group. .)

R ^{6 to} R ⁸ in the formula (4) each independently represent an alkyl group, an alkenyl group, an aryl group, or a hydroxy group, and preferably an alkenyl group, an aryl group, or a hydroxy group.

  Specific examples of the compound represented by the formula (1) or the compound represented by the formula (2) include the following compounds.

  The total content of the compound represented by the formula (1) and / or the compound represented by the formula (2) in the rinsing liquid for relief printing plate making of the present invention is preferably 0.1 to 20% by weight. 0.3 to 10% by weight is more preferable, and 0.5 to 7% by weight is further preferable.

The rinsing liquid for relief printing plate making of the present invention may use a surfactant other than the compound represented by the formula (1) and the compound represented by the formula (2).
In the rinsing liquid for relief printing plate making of the present invention, when a surfactant other than the compound represented by the formula (1) and the compound represented by the formula (2) is used, the amount added is the formula (1). The total weight of the compound represented by formula (2) and the compound represented by formula (2): The total weight of the surfactant other than the compound represented by formula (1) and the compound represented by formula (2) = 1: 1 It is preferably 2 to 1: 0.1, more preferably 1: 1 to 1: 0.1.

<Solvent>
The rinsing liquid for relief printing plate making of the present invention preferably contains water as a main component.
Moreover, the rinsing liquid for relief printing plate making of the present invention may contain a water miscible solvent such as alcohols, acetone and tetrahydrofuran as a solvent other than water. In particular, when a compound having deodorizing ability has low solubility in water, the solubility can be supplemented by adding a water-miscible solvent. As the water-miscible solvent, alcohol is preferable and methanol, ethanol, and isopropanol are particularly preferable from the viewpoint of mixing with water and reducing damage to the relief forming layer. The amount of the water-miscible solvent added to the total amount of the rinsing liquid is preferably 0.1% by weight to 10% by weight, more preferably 0.5 to 5% by weight, and particularly preferably 1 to 5% by weight. It is preferable that the addition amount of the water-miscible solvent is 10% by weight or less because damage to the relief forming layer is small. Moreover, it is preferable that the amount of the water-miscible solvent added is 0.1% by weight or more because the effect of the solvent addition can be obtained.

<Antifoaming agent>
The rinsing liquid for relief printing plate making of the present invention preferably contains an antifoaming agent.
As the antifoaming agent, it is preferable to use a general silicon-based self-emulsifying type, emulsifying type, surfactant nonionic compound having an HLB (Hydrophile-Lipophile Balance) value of 5 or less. Among these, a silicon antifoaming agent is preferable, and an emulsified dispersion type and a solubilized type can be used.
Specific examples of the antifoaming agent include TSA 731 and TSA 739 (manufactured by Toray Dow Corning Co., Ltd.).
The content of the antifoaming agent is preferably 0.001 to 1.0% by weight with respect to the total amount of the rinsing liquid for relief printing plate making.

<Other ingredients>
The rinsing liquid for relief printing plate making of the present invention may contain a preservative, an inorganic acid, and / or a chelating agent, if necessary.
As the preservative, the inorganic acid, and the chelating agent, known ones can be used.

(Relief printing plate making method)
The method for making a relief printing plate of the present invention comprises a step of preparing a relief printing plate precursor having a relief forming layer (hereinafter also referred to as “preparation step”), a step of engraving the relief printing plate precursor by exposure (hereinafter referred to as “ And a step of removing engraving residue generated by engraving with a rinsing liquid (hereinafter, also referred to as “rinsing process”) in this order. A rinsing liquid for relief printing plate making.

<Preparation process>
The plate making method of the relief printing plate of the present invention includes a step of preparing a relief printing plate precursor having a relief forming layer (preparation step).
Although there is no restriction | limiting in particular as a relief printing plate precursor which has a relief forming layer which can be used for the platemaking method of the relief printing plate of this invention, It is preferable that it is a relief printing plate precursor for laser engraving.
In the present invention, the “relief-forming layer” refers to a layer that can be engraved. For example, when a crosslinking agent is used, it refers to a layer that is crosslinked by light or heat. When a crosslinking agent is used, the layer before being crosslinked by light or heat is referred to as an “uncrosslinked relief forming layer”.
In the present invention, the “relief printing plate precursor for laser engraving” refers to a relief printing plate precursor that can be engraved. For example, when a cross-linking agent is used, the relief-forming layer having a crosslinkability made of a resin composition is an optical Or the state hardened | cured with the heat. A “relief printing plate” is produced by laser engraving the printing plate precursor.

The preparation step includes (A) a layer formation step of coating the resin composition on a support to form an uncrosslinked relief forming layer, and the uncrosslinked relief forming layer by at least one of light and heat. A cross-linking step of obtaining a relief printing plate precursor having a relief forming layer by crosslinking, or (B) a step of forming a non-cross-linked relief forming layer by coating the resin composition into a film, the uncross-linked relief forming layer A layer forming step of obtaining a relief printing plate precursor having a relief forming layer by crosslinking with at least one of irradiation with actinic light and heating, and curing one surface of the uncrosslinked relief forming layer or the crosslinked relief forming layer Preferably, it is a crosslinking step, (A) a layer forming step of coating the resin composition on a support to form an uncrosslinked relief forming layer, and the uncrosslinked relief forming layer is subjected to light and heat. And more preferably not even a crosslinking step of obtaining a crosslinked relief printing plate precursor having a relief forming layer by one.
Moreover, it is preferable to dry the coated uncrosslinked relief forming layer as needed. In the present invention, “coating” includes not only coating and providing but also casting.

  As described above, the relief printing plate precursor that can be used in the present invention preferably has a relief forming layer cured by crosslinking. In order to obtain such a relief forming layer, it is preferable that the preparation step includes a step of crosslinking an uncrosslinked relief forming layer in the relief printing plate precursor by light and / or heat.

  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, but ultraviolet light is the most common. If the support side of the relief forming layer is the back side, the surface may only be irradiated with light. However, if the support is a transparent film that transmits actinic rays, it is preferable that the back side is further irradiated with light. When the protective film exists, the irradiation from the surface may be performed while the protective film is provided, or may be performed after the protective film is peeled off. Since polymerization inhibition may occur in the presence of oxygen, actinic rays may be irradiated after the relief forming layer is covered with a vinyl chloride sheet and evacuated.

  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 secondly, the adhesiveness of engraving residue generated during laser engraving is suppressed.

Moreover, the plate making method of the relief printing plate of the present invention comprises a resin composition in which the preparation step includes at least a polymer having a hydroxyl group (—OH) and a compound having a group represented by the formula (I) described later. A step of forming an uncrosslinked relief forming layer by coating on the surface, and a step of obtaining a relief printing plate precursor having a relief forming layer by crosslinking the uncrosslinked relief forming layer with light and / or heat. Is particularly preferred.
By the above process, a relief printing plate precursor having a relief forming layer containing a binder having a group represented by the formula (I) such as an alkoxysilyl group can be easily obtained.
In addition, when the uncrosslinked relief forming layer is cross-linked by light, the resin composition preferably contains a photothermal conversion agent described later.
The resin composition preferably contains a polymerizable compound described later from the viewpoint of improving printing durability.

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.
The irradiation with actinic rays is generally performed on the entire surface of the relief forming layer. Visible light, ultraviolet light, or an electron beam is mentioned as actinic light, but ultraviolet light is the most common. If the substrate side for immobilizing the relief forming layer, such as a support for the relief forming layer, is the back surface, the surface may be irradiated with actinic rays, but the support used is transparent to transmit actinic rays. If it is a film, it is also preferable to irradiate actinic rays from the back side. When the protective film exists, the irradiation from the surface may be performed while the protective film is provided, or may be performed after the protective film is peeled off. Since polymerization inhibition may occur in the presence of oxygen, actinic rays may be irradiated after the crosslinkable 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.

When the crosslinking step is a step of crosslinking by light, an apparatus for irradiating actinic rays is relatively expensive, but the printing plate precursor does not become high temperature, so there are almost no restrictions on the raw materials of the printing plate precursor. Absent.
When the crosslinking step is a step of crosslinking 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 because they may be deformed.
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 compounds 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.

As a crosslinking method of the relief forming layer in the crosslinking step, crosslinking by heat is preferable 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 secondly, 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 have less adhesiveness.

<Engraving process>
The plate making method of the relief printing plate of the present invention includes a step of engraving the relief printing plate precursor by exposure (engraving step).
In the engraving step, it is preferable that a relief is formed by irradiating a laser beam corresponding to an image to be formed with a specific laser to be described later to form a relief.
Specifically, the relief layer is formed by engraving the crosslinked relief forming layer by irradiating a laser beam corresponding to the image to be formed. Preferably, a step of controlling the laser head with a computer based on digital data of an image to be formed and performing scanning irradiation on the relief forming layer can be mentioned. When the infrared laser is irradiated, the molecules in the relief forming layer undergo molecular vibration and heat is generated. When a high-power laser such as a carbon dioxide laser or a YAG laser is used as an infrared laser, a large amount of heat is generated in the laser irradiation portion, and molecules in the photosensitive layer are selectively cut by molecular cutting or ionization, that is, Sculpture is made. At this time, since the exposed region also generates heat due to the photothermal conversion agent in the relief forming layer, the heat generated by the photothermal conversion agent also promotes this removability.
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, the relief can be prevented from falling by printing pressure by engraving with a shallow or shoulder on the part that prints fine halftone dots, and the groove part that prints fine punched letters should be engraved deeply Thus, it becomes difficult for the groove to be filled with ink, and it is possible to suppress the crushing of the extracted characters.
In particular, when engraving with an infrared laser corresponding to the maximum absorption wavelength of the photothermal conversion agent, heat generation from the above-described photothermal conversion agent is efficiently performed, so that a more sensitive and sharp relief layer can be obtained.
As an infrared laser used for engraving, a carbon dioxide laser or a semiconductor laser is preferably used from the viewpoint of productivity, cost, etc. Among them, a semiconductor infrared laser with a fiber described in detail below is particularly preferably used.

In general, a semiconductor laser can be downsized with high efficiency and low cost of laser oscillation compared to a CO ₂ laser. Moreover, since it is small, it is easy to form an array. The control of the beam diameter is performed using an imaging lens and a specific optical fiber. The semiconductor laser with fiber is effective for image formation in the present invention because it can efficiently output laser light by attaching an optical fiber. 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 semiconductor lasers are described in “Laser Handbook 2nd Edition” edited by Laser Society, Practical Laser Technology and Electronic Communication Society.
Further, a plate making apparatus equipped with a fiber-coupled semiconductor laser that can be suitably used in a method for producing a relief printing plate using a relief printing plate precursor is disclosed in Japanese Patent Application Nos. 2008-15460 and 2008 filed by the present applicant. -58160, which can be used to make relief printing plates.

The semiconductor laser used for laser engraving preferably has a wavelength of 700 nm to 1,300 nm, more preferably 800 nm to 1,200 nm, further preferably 860 nm to 1,200 nm, and 900 nm to 1,100 nm. Those are particularly preferred.
Since the band gap of GaAs is 860 nm at room temperature, an AlGaAs-based active layer is generally preferably used in a region less than 860 nm. On the other hand, a semiconductor active layer material of InGaAs type is used at 860 nm or more. In general, since Al is easily oxidized, a semiconductor laser having an active layer of an InGaAs-based material is more reliable than an AlGaAs-based material, and therefore, 860 nm to 1,200 nm is preferable.
Furthermore, as a practical semiconductor laser, considering not only the active layer material but also the composition of the clad material, a semiconductor laser having an InGaAs-based material in the active layer has a more preferable wavelength of 900 nm to 1,100 nm. It is easy to obtain a high output and high reliability in the range. Therefore, it is easy to achieve low cost and high productivity by using a fiber-coupled semiconductor laser having an active layer of an InGaAs-based material having a wavelength of 900 nm to 1,100 nm.
In order to realize a laser engraving relief printing system that is inexpensive and highly productive and has good image quality, a relief printing plate precursor having a relief forming layer using a resin composition for laser engraving as described later is used. In addition, it is preferable to use a semiconductor laser with a specific wavelength as described above and a fiber-attached semiconductor laser.

  By using a semiconductor laser with a fiber, in the control of the shape to be engraved, the engraving area can be changed by changing the beam shape of the semiconductor laser with fiber or changing the amount of energy supplied to the laser without changing the beam shape. This also has the advantage that the shape of the can be changed.

In the method for making a relief printing plate of the present invention, the engraving residue preferably contains a polymer having a group represented by the following formula (I). That is, it is preferable that the resin composition for laser engraving forming the relief forming layer contains a compound having a group represented by the following formula (I).
-M (R ¹ ) (R ² ) _n (I)
(In the formula (I), R ¹ represents OR ³ or a halogen atom, M represents Si, Ti, or Al. When M is Si, n is 2, and when M is Ti, n is 2. And when M is Al, n is 1, each of R ² independently represents a hydrocarbon group, OR ³ or a halogen atom, and R ³ represents a hydrogen atom or a hydrocarbon group.)
R ¹ to R ^3, n and M in the polymer having a group represented by the formula (I), and R ¹ to R ^3, n and M in the compound having a group represented by the formula (I) to be described later It is synonymous and the preferable range is also the same.

<Rinsing process>
The plate making method of the relief printing plate of the present invention includes a step of removing engraving residue generated by engraving with a rinsing liquid (rinsing treatment step).
As the rinsing liquid in the rinsing process, the rinsing liquid for relief printing plate making of the present invention is used.
The relief printing plate immediately after engraving has engraving residue on the surface. In the rinsing process, the engraving residue is removed with the rinsing liquid for relief printing plate making of the present invention.
The amount of the rinsing liquid used is required to cover at least the entire plate with the liquid. The amount used varies depending on the plate, but is preferably 10 ml / m ² or more, more preferably 50 ml / m ² or more, and further preferably 70 ml / m ² or more. Moreover, it is especially preferable that the usage-amount of a rinse liquid is 70-500 ml / m < ² > from the point of the cost of the amount of process liquids.
The means for rinsing in the rinsing process is not particularly limited, but a method of simply washing with a rinsing liquid, a method of spraying a high-pressure rinsing liquid, a batch type or a conveying type known as a photosensitive resin letterpress developing machine. And a method of brushing the engraved surface mainly in the presence of a rinsing liquid.
Further, the rinsing operation may be performed manually, or a plate making apparatus such as a commercially available cleaning apparatus may be used. In the case of processing with a cleaning device, a rinsing liquid can be charged into the tank in the cleaning device for processing. In this case, the liquid is charged in accordance with the tank capacity and processing is performed. As the cleaning device, JOW-1824-WF manufactured by JEOL Ltd. can be used.

Moreover, in the plate-making method of the relief printing plate of this invention, the following drying process and / or a post-crosslinking process may be included as needed.
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.
The plate making method of the relief printing plate of the present invention preferably includes a step of volatilizing the rinse liquid by drying the engraved relief forming layer.
The plate making method of the relief printing plate of the present invention may further include a step of further crosslinking the relief forming layer, if necessary. By performing the post-crosslinking step, the relief formed by engraving can be further strengthened.
Moreover, when a post-crosslinking process is included, it is preferable that the used relief printing plate precursor has a relief forming layer cured by crosslinking.

<Relief printing plate precursor>
The relief printing plate precursor that can be used in the present invention is not particularly limited, and a known relief printing plate precursor can be used, but is preferably a relief printing plate precursor for laser engraving, and a resin composition for laser engraving. It is more preferable to have a relief forming layer comprising The relief forming layer preferably has a crosslinked structure, and is preferably a layer crosslinked by heat and / or light.
The relief forming layer is not particularly limited and a known layer can be used, and it is a layer made of a resin composition for laser engraving described later, or a layer obtained by curing a resin composition for laser engraving described later. Is preferred. The relief forming layer is preferably provided on the support.

If necessary, the relief printing plate precursor for laser engraving may further have an adhesive layer between the support and the relief forming layer, and a slip coat layer and a protective film on the relief forming layer.
The relief forming layer can be formed, for example, by using a coating liquid composition and molding it into a sheet shape or a sleeve shape. As a coating liquid composition, the resin composition for laser engraving mentioned later can be illustrated preferably.

<Support>
The relief printing plate precursor that can be used in the present invention may have a support.
The material used for the support in the relief printing plate precursor is not particularly limited, but materials having high dimensional stability are preferably used. For example, metals such as steel, stainless steel, and aluminum, polyester resins (for example, PET, PBT, PAN) ) And plastic resins such as polyvinyl chloride, synthetic rubbers such as styrene-butadiene rubber, and plastic resins reinforced with glass fibers (such as epoxy resins and phenol resins). As the support, a PET (polyethylene terephthalate) 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.
Also, a laser engraving produced by applying a crosslinkable resin composition for laser engraving and curing it from the back surface (opposite to the surface on which laser engraving is performed, including cylindrical ones) with light or heat. In the relief printing plate precursor for use, since the back side of the cured resin composition for laser engraving functions as a support, the support is not always essential.

<Adhesive layer>
An adhesive layer may be provided between the relief forming layer and the support for the purpose of enhancing the adhesive force between the two layers. As a material (adhesive) that can be used for the adhesive layer, for example, those described in I. Skeist, “Handbook of Adhesives”, 2nd edition (1977) can be used.

<Protective film, slip coat layer>
For the purpose of preventing scratches and dents on the surface of the relief forming layer, a protective film may be provided on the surface of the 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 (polyethylene terephthalate) or a polyolefin film such as PE (polyethylene) or PP (polypropylene) can be used. The surface of the film may be matted. When providing a protective film on a relief forming layer, the protective film must be 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

(Relief printing plate precursor preparation method)
Next, a method for producing a relief printing plate precursor will be described.
The formation of the relief forming layer in the relief printing plate precursor is not particularly limited. For example, a relief forming layer coating solution composition (containing a resin composition for laser engraving) is prepared, and this relief forming layer is used. The method of melt-extruding on a support after removing a solvent from a coating liquid composition is mentioned. Or the method of casting the coating liquid composition for relief forming layers on a support body, drying this in oven, and removing a solvent from a coating liquid composition may be sufficient.
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 a protective film is used, a method of first laminating a relief forming layer on the protective film and then laminating the support may be employed.
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.

  The coating composition for the relief forming layer can be produced, for example, by dissolving a polymer and, as an optional component, a photothermal conversion agent and a plasticizer in an appropriate solvent, and then dissolving a polymerizable compound and a polymerization initiator. . Since most of the solvent components need to be removed at the stage of producing the relief printing plate precursor, low-molecular alcohols (e.g., methanol, ethanol, n-propanol, isopropanol, propylene glycol monomethyl ether, which are volatile) are easily used as solvents. ) And the like, and adjusting the temperature, it is preferable to keep the total amount of the solvent added as small as possible.

Here, in the present invention, in the case of a relief printing plate precursor for laser engraving, it refers to the state in which the relief forming layer is crosslinked as described above. In the method of crosslinking the relief forming layer, it is preferable to perform a step of crosslinking the relief forming layer by irradiation with actinic rays and / or heating.
In addition, “crosslinking” as used herein is a concept including a crosslinking reaction for linking polymers, a crosslinking reaction between crosslinking agents, a polymerization reaction between a polymerizable compound having an ethylenically unsaturated bond, and a polymer. It is also a concept including a curing reaction of the relief forming layer by a reaction of a crosslinking agent and a polymerizable compound.

  The thickness of the relief forming layer in the relief printing plate precursor is preferably from 0.05 mm to 10 mm, more preferably from 0.05 mm to 7 mm, particularly preferably from 0.05 mm to 3 mm.

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 forming 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 printing pressure of kiss touch.
In addition, the Shore A hardness in this specification is measured by measuring the amount of deformation (indentation depth) by pressing and deforming an indenter (called a push needle or indenter) on the surface of the object to be measured at 25 ° C. and 50% RH. The value measured with a durometer (spring type rubber hardness meter) for digitization.

  The relief printing plate produced by the method for making a relief printing plate of the present invention can be printed with oil-based ink or UV ink by a relief printing press, and can also be printed with UV ink by a flexographic printing press. is there.

<Resin engraving resin composition>
The resin composition for laser engraving (hereinafter also simply referred to as “resin composition”) that can be used in the present invention preferably contains at least a binder.

As an application mode of the resin composition, 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, an intaglio, and a stencil , Stamps and the like, but are not limited thereto.
Hereinafter, the components of the resin composition for laser engraving will be described.

[Crosslinking agent]
The resin composition for laser engraving preferably contains a crosslinking agent.
In the present invention, from the viewpoint of forming a crosslinked structure in the relief forming layer, the relief forming layer resin composition preferably contains a crosslinking agent in order to form the crosslinked structure.
The crosslinking agent that can be used in the present invention is not particularly limited as long as it can be polymerized by a chemical reaction caused by light or heat to cure the relief forming layer. In particular, a polymerizable compound having an ethylenically unsaturated group (hereinafter also referred to as “polymerizable compound”), a reactive silane compound having a reactive silyl group such as an alkoxysilyl group or a halogenated silyl group, and a reactive titanium compound. A reactive aluminum compound is preferably used, and a reactive silane compound is more preferably used. These compounds may form a crosslinked structure in the relief forming layer by reacting with the binder, or may form a crosslinked structure by reacting with each other, and both of these reactions. A cross-linked structure may be formed.
The polymerizable compound that can be used here can be arbitrarily selected from compounds having at least 1, preferably 2 or more, more preferably 2 to 6 ethylenically unsaturated groups.

The resin composition for laser engraving preferably contains a compound having a group represented by the following formula (I) (hereinafter also referred to as “compound (I)”).
-M (R ¹ ) (R ² ) _n (I)
(In the formula (I), R ¹ represents OR ³ or a halogen atom, M represents Si, Ti, or Al. When M is Si, n is 2, and when M is Ti, n is 2. And when M is Al, n is 1, each of R ² independently represents a hydrocarbon group, OR ³ or a halogen atom, and R ³ represents a hydrogen atom or a hydrocarbon group.)

In formula (I), M represents Si, Ti, or Al. Among these, M is preferably Si or Ti, and more preferably Si.
In the formula (I), R ¹ represents OR ³ or a halogen atom, R ³ represents a hydrogen atom or a hydrocarbon group, and the hydrocarbon group includes an alkyl group having 1 to 30 carbon atoms and 6 to 30 carbon atoms. Aryl groups having 2 to 30 carbon atoms, aralkyl having 7 to 37 carbon atoms, and the like. Among these, R ³ is preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 20 carbon atoms, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or 6 to 6 carbon atoms. 10 aryl groups are more preferable, and a methyl group or ethyl group is particularly preferable. That is, R ¹ is particularly preferably a methoxy group or an ethoxy group.
R ¹ is -M (R ²⁾ _n O when treated with an alkaline rinse solution ^- is preferably one that ionized.

In the formula (I), R ² represents a hydrocarbon group, OR ³ or a halogen atom. R ³ represents a hydrogen atom or a hydrocarbon group, R ³ is as described above, and the preferred range is also the same.
R ² is preferably OR ³ or a halogen atom, and more preferably OR ³ .

N is 2 when M is Si. When M is Si, a plurality of R ² may be the same or different, and is not particularly limited.
N is 2 when M is Ti. When M is Ti, a plurality of R ² may be the same or different, and is not particularly limited.
When M is Al, n represents 1.

  In addition, the compound (I) may be one in which a group represented by the above formula (I) is introduced into the polymer by reaction with a polymer, and has a group represented by the above formula (I) before the reaction, A group represented by the above formula (I) may be introduced into the polymer.

As the compound (I), an embodiment in which M is Si is particularly preferable.
When M is Si, it is also possible to use a silane coupling agent as the compound having the group represented by the formula (I) (compound (I)). The silane coupling agent is a compound having a group capable of reacting with an inorganic component such as an alkoxysilyl group and a group capable of reacting with an organic component such as a methacryloyl group, and capable of binding the inorganic component and the organic component. is there. The same applies to titanium coupling agents and aluminate coupling agents.
Compound (I) has a reactive group such as a vinyl group, an epoxy group, a methacryloyloxy group, an acryloyloxy group, a mercapto group, and an amino group, and reacts with the polymer with the reactive group, whereby the polymer has the formula (I It is also preferred that a group represented by

Examples of the silane coupling agent include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ -Glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ- Methacryloxypropyltriethoxysilane, γ-acryloxypropyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropylmethyldimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimeth Sisilane, N- (β-aminoethyl) -γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercapto Examples thereof include propyltrimethoxysilane, γ-chloropropyltrimethoxysilane, and γ-ureidopropyltriethoxysilane.
As the compound (I), a compound having a plurality of groups represented by the formula (I) is also preferably used. In such a case, the group represented by the formula (I) can be introduced into the polymer by reacting a part of the group represented by the formula (I) with the polymer. For example, the R ¹ group and optionally the R ² group of compound (I) react with an atom and / or group (eg, hydroxyl group (—OH)) that can react with the compound in the polymer (eg, alcohol exchange). react. In addition, when a plurality of groups represented by the formula (I) are bonded to the polymer, the compound (I) also functions as a crosslinking agent, and can form a crosslinked structure.
Such a compound (I) is preferably a compound having a plurality of groups represented by the formula (I), and preferably a compound having 2 to 6 groups represented by the formula (I). More preferred is a compound having 2 to 3 groups represented by the formula (I).
Although the compounds shown below are preferred, 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.

In the present invention, silica particles, titanium oxide particles, aluminum oxide particles and the like can also be used as the compound (I). These particles can react with a polymer described later to introduce a group represented by the above formula (I) into the polymer. For example, -SiOH is introduced by the reaction between silica particles and a polymer described later.
Other examples of titanium coupling agents include Ajinomoto Fine Techno Co., Ltd. Preneact, Matsumoto Fine Chemical Co., Ltd. Titanium Tetraisopropoxide, Nippon Soda Co., Ltd. Titanium-i-propoxybis (acetylacetonato) titanium. An example of the aluminate coupling agent is acetoalkoxyaluminum diisopropylate.

In this invention, said compound (I) may be used individually by 1 type, and may use 2 or more types together.
In this invention, it is preferable that content of the compound (I) contained in the resin composition for relief forming layers is 0.1-80 weight% in conversion of solid content, and it is more preferable that it is 1-40 weight%. Preferably, it is 5 to 30% by weight.

In the present invention, from the viewpoint of forming a crosslinked structure in the relief forming layer, the relief forming layer coating liquid preferably contains a polymerizable compound in order to form the crosslinked structure.
The polymerizable compound that can be used here can be arbitrarily selected from compounds having at least one ethylenically unsaturated group, preferably two or more, and more preferably 2-6.
Further, in the present invention, a compound having only one ethylenically unsaturated group (monofunctional polymerizable compound, monofunctional monomer) from the viewpoint of film physical properties such as flexibility and brittleness in addition to the purpose of forming a crosslinked structure. ) May be used.

Hereinafter, a compound (monofunctional monomer) having one ethylenically unsaturated group in the molecule and a compound (polyfunctional monomer) having two or more ethylenically unsaturated groups in the molecule used as a polymerizable compound explain.
Since the relief forming layer is required to have a crosslinked structure in the film, a polyfunctional monomer is preferably used. The molecular weight of these polyfunctional monomers is preferably 200 to 2,000.
Examples of monofunctional monomers and polyfunctional monomers include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.) and esters of polyhydric alcohol compounds, unsaturated carboxylic acids, Examples include amides with polyvalent amine compounds.

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

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

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

The molecular weight of the sulfur-containing polyfunctional monomer in the present invention is preferably 120 to 3,000, more preferably 120 to 1,500, from the viewpoint of the flexibility of the formed film.
Moreover, although the sulfur-containing polyfunctional monomer in this invention may be used independently, you may use it as a mixture with the polyfunctional polymerizable compound and monofunctional polymerizable compound which do not have a sulfur atom in a molecule | numerator.
From the viewpoint of engraving sensitivity, it is preferable to use the sulfur-containing polyfunctional monomer alone or as a mixture of the sulfur-containing polyfunctional monomer and the monofunctional monomer, and use it as a mixture of the sulfur-containing polyfunctional monomer and the monofunctional monomer. An embodiment is more preferred.

In the relief forming layer, film properties such as brittleness and flexibility can be adjusted by using a polymerizable compound such as a sulfur-containing polyfunctional monomer.
Further, the total content of the polymerizable compound including the sulfur-containing polyfunctional monomer in the relief forming layer is preferably 10 to 60% by weight with respect to the nonvolatile component from the viewpoint of the flexibility and brittleness of the crosslinked film. The range of 15 to 45% by weight is more preferable.
In addition, when using together a sulfur-containing polyfunctional monomer and another polymeric compound, 5 weight% or more is preferable and, as for the quantity of the sulfur-containing polyfunctional monomer in all the polymeric compounds, 10 weight% or more is more preferable.

〔binder〕
The resin composition for laser engraving preferably contains a binder (hereinafter also referred to as “binder polymer”).
The binder 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 a printing plate precursor, it is necessary to select it in consideration of various performances such as laser engraving property, ink acceptability, and engraving residue dispersibility.
As binders, polystyrene resin, polyester resin, polyamide resin, polyurea resin, polyamideimide resin, polyurethane resin, polysulfone resin, polyethersulfone resin, polyimide resin, polycarbonate resin, hydrophilic polymer containing hydroxyethylene units, acrylic resin, acetal A resin, an epoxy resin, a polycarbonate resin, rubber, a thermoplastic elastomer, or the like can be selected and used.

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

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

As the binder, it is particularly preferable to use a polymer having a hydroxyl group (—OH) (hereinafter also referred to as “specific polymer”). The skeleton of the specific polymer is not particularly limited, but an acrylic resin, an epoxy resin, a hydrophilic polymer containing a hydroxyethylene unit, a polyvinyl acetal resin, a polyester resin, and a polyurethane resin are preferable.
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. A copolymer obtained by polymerizing these and a known (meth) acrylic monomer or vinyl monomer can be preferably used.
It is also possible to use an epoxy resin having a hydroxy group in the side chain as the specific polymer. As a preferable specific example, an epoxy resin obtained by polymerizing an adduct of bisphenol A and epichlorohydrin as a raw material monomer is preferable.
As the polyester resin, a polyester resin composed of hydroxyl carboxylic acid units such as polylactic acid can be preferably used. Specific examples of the polyester resin 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 are preferred.

The specific polymer is preferably a polymer having an atom and / or group capable of reacting with the compound (I), and is a polymer having an atom and / or group capable of reacting with the compound (I) and is insoluble in water. And it is more preferable that it is a binder polymer soluble in a C1-C4 alcohol.
Although it does not specifically limit as an atom and / or group which can react with the said compound (I), An ethylenically unsaturated bond, an epoxy group, an amino group, a (meth) acryloyl group, a mercapto group, a hydroxy group is illustrated, These Of these, hydroxy groups are preferred.

  As a specific polymer in the present invention, polyvinyl butyral (PVB), an acrylic resin having a hydroxyl group in a side chain, and a film having good engraving sensitivity and good film property while achieving both water-based ink suitability and UV ink suitability Preferred examples include an epoxy resin having a hydroxyl group in the side chain.

  The specific polymer that can be used in the present invention is a preferred combined component of the resin composition for laser engraving constituting the relief forming layer in the present invention, and photothermal conversion capable of absorbing light having a wavelength of 700 to 1,300 nm described later. When combined with an agent, a glass transition temperature (Tg) of 20 ° C. or higher is particularly preferable because engraving sensitivity is improved. Hereinafter, a polymer having such a glass transition temperature is referred to as a non-elastomer. That is, an elastomer is generally defined academically as a polymer having a glass transition temperature of room temperature or lower (see Science Dictionary 2nd edition, Editor International Science Promotion Foundation, published by Maruzen Co., Ltd., P154). . Therefore, a non-elastomer refers to a polymer having a glass transition temperature exceeding normal temperature. Although there is no restriction | limiting in the upper limit of the glass transition temperature of a specific polymer, it is preferable from a viewpoint of handleability that it is 200 degrees C or less, and it is more preferable that it is 25 degreeC or more and 120 degrees C or less.

When a polymer having a glass transition temperature of room temperature (20 ° C.) or higher is used, the specific polymer takes a glass state at room temperature. Therefore, a thermal molecular motion is considerably suppressed as compared with a rubber state. It is in. In laser engraving, in addition to the heat imparted by the infrared laser during laser irradiation, the heat generated by the function of the photothermal conversion agent used in combination with the desired heat is transferred to the specific polymer around it, which decomposes and dissipates. As a result, engraving is performed to form a recess.
When a specific polymer is used, if a photothermal conversion agent is present in a state where thermal molecular motion of the specific polymer is suppressed, heat transfer to the specific polymer and thermal decomposition are considered to occur effectively. It is presumed that the engraving sensitivity is further increased due to various effects.

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

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

Hereinafter, although polyvinyl butyral (PVB) and its derivative (s) are mentioned and demonstrated as a particularly preferable example of polyvinyl acetal, it is not limited to this.
As PVB, it can also be obtained as a commercial product, and preferred specific examples thereof include “ESREC B” series and “ESREC K” manufactured by Sekisui Chemical Co., Ltd. from the viewpoint of alcohol solubility (particularly ethanol solubility). (KS) "series," Denkabutyral "manufactured by Denki Kagaku Kogyo Co., Ltd. are preferred. More preferably, from the viewpoint of alcohol solubility (especially ethanol), “S-Lec B” series manufactured by Sekisui Chemical Co., Ltd. and “Denka Butyral” manufactured by Denki Kagaku Kogyo Co., Ltd. are particularly preferable. In the “ES REC B” series manufactured by Co., Ltd., “BL-1”, “BL-1H”, “BL-2”, “BL-5”, “BL-S”, “BX-L”, “BM-” "# 3000-1", "# 3000-2", "# 3000-4", "# 4000-2", "S", "BH-S", and Denka Butyral manufactured by Denki Kagaku Kogyo Co., Ltd. “# 6000-C”, “# 6000-EP”, “# 6000-CS”, “# 6000-AS”.
When a relief forming layer is formed using PVB as a specific polymer, a method in which a solution dissolved in a solvent is cast and dried is preferable from the viewpoint of the smoothness of the surface of the membrane.

(2) Acrylic resin As the acrylic resin that can be used as the specific polymer, any acrylic resin obtained using a known acrylic monomer and having 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.

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 such acrylic monomers include (meth) acrylic acid esters such as 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-methoxy Ethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2- (2-methoxyethoxy) ethyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, diethylene glycol mono Tyl ether (meth) acrylate, diethylene 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 (meta ) Acrylate, N, N-diethylaminoethyl (meth) acrylate, N N- dimethylaminopropyl (meth) acrylate.
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.

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

Among the specific polymers, polyvinyl butyral and its derivatives are particularly preferable from the viewpoint of rinsing properties and printing durability when used as a relief forming layer.
The content of the hydroxyl group contained in the specific polymer in the present invention is preferably 0.1 to 15 mmol / g, more preferably 0.5 to 7 mmol / g in any of the above-described polymers. .
Only 1 type of specific polymer may be used for a resin composition, and 2 or more types may be used together.
The weight average molecular weight (in terms of polystyrene by GPC measurement) of the binder that can be used in the present invention is preferably 5,000 to 1,000,000, more preferably 8,000 to 750,000. Most preferably, it is from 1,000,000 to 500,000.
The preferred content of the specific polymer in the resin composition that can be used in the present invention is 2 to 95% by weight 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. It is preferable that there is, more preferably 5 to 80% by weight, particularly preferably 10 to 60% by weight.

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

  As the polymer used, 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. This is described in detail in paragraphs 0039 to 0040 of JP 2008-163081 A. Furthermore, it is preferable to use a hydrophilic or alcoholic polymer from the viewpoint of easy preparation of the composition for a relief forming layer and improvement in resistance to oil-based ink in the obtained relief printing plate. As the hydrophilic polymer, those described in detail in paragraph 0041 of JP-A-2008-163081 can be used.

  In addition, polyesters composed of hydroxycarboxylic 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 are preferred.

In addition, when used for the purpose of curing by heating or exposure and improving the strength, a polymer having a carbon-carbon unsaturated bond in the molecule is preferably used.
Examples of such a polymer that includes a carbon-carbon unsaturated bond in the main chain include SB (polystyrene-polybutadiene), SBS (polystyrene-polybutadiene-polystyrene), SIS (polystyrene-polyisoprene-polystyrene), and SEBS. (Polystyrene-polyethylene / polybutylene-polystyrene) and the like.

As a polymer having a carbon-carbon unsaturated bond in the side chain, a carbon-carbon unsaturated bond such as an allyl group, an acryloyl group, a methacryloyl group, a styryl group, or a vinyl ether group is introduced into the side chain of the binder polymer. It is obtained by doing. In the method of introducing a carbon-carbon unsaturated bond into the side chain of the binder polymer, a structural unit having a polymerizable group precursor formed by bonding a protective group to a polymerizable group is copolymerized with the polymer, and the protective group is eliminated. To prepare a polymer compound having a plurality of reactive groups such as a hydroxyl group, an amino group, an epoxy group, and a carboxyl group, and to react with these reactive groups and a carbon-carbon unsaturated bond. A known method such as a method of introducing the compound having a polymer reaction by polymer reaction can be employed. According to these methods, the amount of unsaturated bonds and polymerizable groups introduced into the polymer compound can be controlled.
Thus, in consideration of the physical properties according to the application application of the relief printing plate, a combined polymer according to the purpose can be selected, and one type of the combined polymer or a combination of two or more types can be used.

  The weight average molecular weight (in terms of polystyrene by GPC measurement) of the combined polymer in the present invention is preferably from 50,000 to 500,000. If the weight average molecular weight is 50,000 or more, the form retainability as a single resin is excellent, and if it is 500,000 or less, it is easy to dissolve in a solvent such as water, which is convenient for preparing a relief forming layer. The weight average molecular weight of the combined use polymer is more preferably 10,000 to 400,000, and particularly preferably 15,000 to 300,000.

The total content of the polymer (binder polymer) (the total content of the specific polymer and the combination polymer) is preferably 5 to 95% by weight, preferably 15 to 80% by weight, based on the total solid content of the resin composition for laser engraving. Is more preferable, and 20 to 65% by weight is more preferable.
For example, when the resin composition for laser engraving is applied to the relief forming layer of a relief printing plate precursor, the resulting relief printing plate can be used as a printing plate by setting the binder polymer content to 5% by weight or more. Insufficient printing durability is obtained, and by making it 95% by weight or less, other components are not deficient, and flexibility sufficient to be used as a printing plate even when a relief printing plate is used as a flexographic printing plate. Obtainable.

〔solvent〕
In the present invention, it is preferable that the solvent used when preparing the resin composition is mainly an aprotic organic solvent from the viewpoint of promptly proceeding the reaction between the compound (I) and the specific polymer. More specifically, it is preferable to use an aprotic organic solvent / protic organic solvent = 100/0 to 50/50 (weight ratio). More preferably, it is 100 / 0-70 / 30, Most preferably, it is 100 / 0-90 / 10.
Preferred specific examples of the aprotic organic solvent include acetonitrile, tetrahydrofuran, dioxane, toluene, propylene glycol monomethyl ether acetate, methyl ethyl ketone, acetone, methyl isobutyl ketone, ethyl acetate, butyl acetate, ethyl lactate, N, N-dimethylacetamide, N-methylpyrrolidone and dimethyl sulfoxide.
Preferred specific examples of the protic organic solvent are methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 1-methoxy-2-propanol, ethylene glycol, diethylene glycol, and 1,3-propanediol.

[Alcohol exchange reaction catalyst]
When using compound (I) for a resin composition, in order to accelerate | stimulate reaction with compound (I) and a specific polymer, it is preferable to contain an alcohol exchange reaction catalyst.
The alcohol exchange reaction catalyst can be applied without limitation as long as it is a commonly used reaction catalyst.
Hereinafter, an acid or basic catalyst, which is a typical alcohol exchange reaction catalyst, and a metal complex catalyst will be sequentially described.

-Acid or basic catalyst-
As the catalyst, an acid or a basic compound is used as it is, or a catalyst in which it is dissolved in a solvent such as water or an organic solvent (hereinafter referred to as an acidic catalyst and a basic catalyst, respectively). The concentration at the time of dissolving in the solvent is not particularly limited, and may be appropriately selected according to the characteristics of the acid or basic compound used, the desired content of the catalyst, and the like.
The type of acidic catalyst or basic catalyst is not particularly limited. Specifically, examples of the acidic catalyst include hydrogen halides such as hydrochloric acid, nitric acid, sulfuric acid, sulfurous acid, hydrogen sulfide, perchloric acid, hydrogen peroxide, carbonic acid, Examples of the basic catalyst include carboxylic acids such as formic acid and acetic acid, substituted carboxylic acids obtained by substituting R of the structural formula represented by RCOOH with other elements or substituents, sulfonic acids such as benzenesulfonic acid, and phosphoric acid. Include ammoniacal bases such as aqueous ammonia and amines such as ethylamine and aniline. From the viewpoint of promptly proceeding the alcohol exchange reaction in the layer, methanesulfonic acid, p-toluenesulfonic acid, pyridinium p-toluenesulfonate, phosphoric acid, phosphonic acid, and acetic acid are preferable, and methanesulfonic acid, p-toluenesulfonic acid. Phosphoric acid is particularly preferred.

-Metal complex catalyst-
The metal complex catalyst used as the alcohol exchange reaction catalyst in the present invention is preferably a metal element selected from the group consisting of groups 2, 4, 5 and 13 of the periodic table, β-diketone (preferably acetylacetone, etc.), ketoester , Hydroxycarboxylic acid or its ester, amino alcohol, and an oxo or hydroxy oxygen compound selected from the group consisting of enolic active hydrogen compounds.
Furthermore, among the constituent metal elements, group 2 elements such as Mg, Ca, St, and Ba, group 4 elements such as Ti and Zr, group 5 elements such as V, Nb, and Ta, and 13 such as Al and Ga. Group elements are preferred and each form a complex with an excellent catalytic effect. Among them, complexes obtained from Zr, Al, or Ti are excellent, and ethyl orthotitanate is particularly preferable.
These are excellent in stability in aqueous coating solutions and in gelation promoting effect in sol-gel reaction during heating and drying. Among them, ethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate), di ( Particularly preferred are acetylacetonato) titanium complex and zirconium tris (ethylacetoacetate).

  In the resin composition, only one type of alcohol exchange reaction catalyst may be used, or two or more types may be used in combination. The content of the alcohol exchange reaction catalyst in the resin composition is preferably 0.01 to 20% by weight and more preferably 0.1 to 10% by weight with respect to the polymer having a hydroxyl group.

(Polymerization initiator)
The resin composition for laser engraving preferably contains a polymerization initiator, and more preferably uses a compound having an ethylenically unsaturated group and a polymerization initiator in combination.
A well-known thing can be used for a polymerization initiator without a restriction | limiting. Hereinafter, although the radical polymerization initiator which is a preferable polymerization initiator is explained in full detail, this invention is not restrict | limited by these description.

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

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

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

  Moreover, as a polymerization initiator, it can divide roughly into a photoinitiator and a thermal-polymerization initiator. In the present invention, a thermal polymerization initiator is preferably used from the viewpoint of improving the degree of crosslinking. As the thermal polymerization initiator, (c) an organic peroxide and (l) an azo compound are preferably used. In particular, the following compounds are preferred.

(C) Organic peroxide As a radical polymerization initiator that can be used in the present invention, preferred (c) organic peroxide is 3,3′4,4′-tetra (t-butylperoxycarbonyl) benzophenone. 3,3′4,4′-tetra (t-amylperoxycarbonyl) benzophenone, 3,3′4,4′-tetra (t-hexylperoxycarbonyl) benzophenone, 3,3′4,4′- Tetra (t-octylperoxycarbonyl) benzophenone, 3,3′4,4′-tetra (cumylperoxycarbonyl) benzophenone, 3,3′4,4′-tetra (p-isopropylcumylperoxycarbonyl) benzophenone, Peroxide esters such as di-t-butyldiperoxyisophthalate are preferred.

(L) Azo compound As a radical polymerization initiator that can be used in the present invention, preferred (l) azo compounds include 2,2′-azobisisobutyronitrile and 2,2′-azobispropio. Nitrile, 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- Methylpropionamidooxime), 2,2′-azobis [2- (2-imidazolin-2-yl) propane], 2,2′-azobis {2-methyl-N- [1,1-bis (hydroxymethyl)] − -Hydroxyethyl] propionamide}, 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) propionamide], 2,2′-azobis (N-butyl-2-methylpropionamide), 2 , 2′-azobis (N-cyclohexyl-2-methylpropionamide), 2,2′-azobis [N- (2-propenyl) -2-methylpropionamide], 2,2′-azobis (2,4,4) 4-trimethylpentane) and the like.

The polymerization initiator in the present invention may be used alone or in combination of two or more.
The polymerization initiator can be added at a ratio of preferably 0.01 to 10% by weight, more preferably 0.1 to 3% by weight, based on the total solid content of the resin composition for laser engraving.

[Photothermal conversion agent]
The relief forming layer preferably contains a photothermal conversion agent.
The resin composition for laser engraving preferably contains a photothermal conversion agent.
It is considered that the photothermal conversion agent promotes thermal decomposition of the cured product of the resin composition for laser engraving 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 having a wavelength of 700 nm to 1,300 nm is used as a light source for laser engraving, the relief forming layer in the present invention has a thickness of 700 nm to 1,300 nm. It is preferable to contain the photothermal conversion agent which can absorb the light of this wavelength.
Various dyes and / or pigments are used as the photothermal conversion agent in the present invention.
More preferably, the photothermal conversion agent is at least one photothermal conversion agent selected from pigments and dyes having absorption at 800 nm to 1,200 nm.
The photothermal conversion agent is preferably a pigment.

  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 nm to 1,300 nm. Azo dyes, metal complex salt azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, diimmonium compounds, quinone imine dyes , Methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, and metal thiolate complexes. In particular, cyanine dyes such as heptamethine cyanine dye, oxonol dyes such as pentamethine oxonol dye, and phthalocyanine dyes are preferably used. Examples thereof include the dyes described in paragraphs 0124 to 0137 of JP-A-2008-63554.

  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 addition, black colorants such as carbon black can be used as color chips or color pastes previously dispersed in nitrocellulose or the like by using a dispersant as required in order to facilitate dispersion. Chips and pastes are easily available 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 preferably has a dibutyl phthalate (DBP) oil absorption of less than 150 ml / 100 g.
In addition, as the carbon black, conductive carbon black having a specific surface area of at least 150 m ² / g is preferable from the viewpoint of improving engraving sensitivity by efficiently transferring heat generated by photothermal conversion to surrounding polymers and the like. .

  The content of the photothermal conversion agent in the laser forming layer or the resin composition for laser engraving varies greatly depending on the molecular extinction coefficient inherent to the molecule, but is 0% of the total solid weight of the resin composition. The range of 0.01 to 20% by weight is preferable, the range of 0.05 to 10% by weight is more preferable, and the range of 0.1 to 5% by weight is particularly preferable.

<Other additives>
The resin composition for laser engraving and the relief layer of the relief printing plate precursor may contain known additives in addition to those described above.
The resin composition for laser engraving preferably contains a plasticizer.
The plasticizer has a function of softening a film formed of the resin composition for laser engraving and needs to be compatible with the polymer.
As the plasticizer, for example, dioctyl phthalate, didodecyl phthalate, tributyl citrate and the like, polyethylene glycols, polypropylene glycol (monool type and diol type), polypropylene glycol (monool type and diol type) and the like are preferably used. .
The resin composition for laser engraving is more preferably added with nitrocellulose or a highly thermally conductive substance as an additive for improving engraving sensitivity. Since nitrocellulose is a self-reactive compound, it generates heat during laser engraving and assists in the thermal decomposition of coexisting polymers such as hydrophilic polymers. As a result, it is estimated that the engraving sensitivity is improved. The high thermal conductive material is added for the purpose of assisting heat transfer, and examples of the thermal conductive material include inorganic compounds such as metal particles and organic compounds such as conductive polymers. As the metal particles, the conductive polymer is preferably a gold fine particle, a silver fine particle, or a copper fine particle having a particle size of micrometer order to several nanometer order. Particularly, a conjugated polymer is preferable, and specifically, polyaniline and polythiophene are mentioned. It is done.
Moreover, the sensitivity at the time of photocuring the resin composition for laser engraving can be further improved by using a co-sensitizer.
Furthermore, it is desirable to add a small amount of a thermal polymerization inhibitor in order to prevent unnecessary thermal polymerization of the polymerizable compound during the production or storage of the composition.
A colorant such as a dye or pigment may be added for the purpose of coloring the resin composition for laser engraving. Thereby, properties such as the visibility of the image portion and the suitability of the image density measuring device can be improved.
Furthermore, in order to improve the physical properties of the cured film of the resin composition for laser engraving, a known additive such as a filler may be added.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example.

(Preparation of relief printing plate precursor A)
1. Preparation of Crosslinkable Resin Composition for Laser Engraving 50 g of Denkabutyral # 3000-2 (manufactured by Denki Kagaku Kogyo Co., Ltd., polyvinyl butyral Mw = 90,000) as a polymer in a three-necked flask equipped with a stirring blade and a cooling tube Then, 47 g of propylene glycol monomethyl ether acetate was added as a solvent and heated at 70 ° C. for 120 minutes with stirring to dissolve the polymer. Thereafter, 15 g of tributyl citrate as a plasticizer, 8 parts by weight of Bremer LMA (dodecyl methacrylate, manufactured by NOF Corporation) as a polymerizable compound, and perbutyl Z (manufactured by NOF Corporation) as a polymerization initiator are 1. 6 g, 1 g of carbon black (Show Black N110, manufactured by Cabot Japan Co., Ltd., DBP oil absorption 115 ml / 100 g) as a photothermal conversion agent was added and stirred for 30 minutes. Thereafter, 15 g of KBE-846 (manufactured by Shin-Etsu Chemical Co., Ltd.) as a crosslinking agent and 0.4 g of phosphoric acid as a catalyst were added and stirred at 70 ° C. for 10 minutes. By this operation, a flowable crosslinkable relief forming layer coating solution A (crosslinkable resin composition for laser engraving) was obtained.

2. Preparation of relief printing plate precursor for laser engraving A spacer (frame) having a predetermined thickness is placed on a PET substrate, and the coating solution A for the crosslinkable relief forming layer obtained above is gently so as not to flow out of the spacer (frame). The relief forming layer having a thickness of about 1 mm was provided by casting and drying in an oven at 70 ° C. for 3 hours to prepare a relief printing plate precursor A for laser engraving.

(Preparation of relief printing plate precursor B)
1. Preparation of Crosslinkable Resin Composition for Laser Engraving 50 g of Denkabutyral # 3000-2 (manufactured by Denki Kagaku Kogyo Co., Ltd., polyvinyl butyral Mw = 90,000) as a polymer in a three-necked flask equipped with a stirring blade and a cooling tube Then, 47 g of propylene glycol monomethyl ether acetate was added as a solvent and heated at 70 ° C. for 120 minutes with stirring to dissolve the polymer. Thereafter, 15 g of tributyl citrate as a plasticizer, 8 parts by weight of Bremer LMA (dodecyl methacrylate, manufactured by NOF Corporation) as a polymerizable compound, and perbutyl Z (manufactured by NOF Corporation) as a polymerization initiator are 1. 6 g, 1 g of carbon black (Show Black N110, manufactured by Cabot Japan Co., Ltd., DBP oil absorption 115 ml / 100 g) as a photothermal conversion agent was added and stirred for 30 minutes. Thereafter, 15 g of KBE-846 (manufactured by Shin-Etsu Chemical Co., Ltd.) as a crosslinking agent and 0.4 g of phosphoric acid and silica particles (Aerosil 200CF) as a catalyst were added and stirred at 70 ° C. for 10 minutes. By this operation, a flowable crosslinkable relief forming layer coating liquid B (crosslinkable resin composition for laser engraving) was obtained.

2. Preparation of relief printing plate precursor for laser engraving A relief printing plate precursor B was prepared in the same manner as the relief printing plate precursor A, except that the coating liquid B for relief forming layer was used.

(Relief printing plate making)
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 the following laser.
A high-quality CO ₂ laser marker ML-9100 series (manufactured by KEYENCE, Inc.) was used as a carbon dioxide laser engraving machine. Relief printing plate precursors A and B were raster-engraved with a carbon dioxide laser engraving machine with a carbon dioxide laser engraving machine under conditions of output: 12 W, head speed: 200 mm / second, pitch setting: 2,400 DPI.
The thickness of the relief layer of the relief printing plate was about 1 mm.

<Rinse process>
(Preparation of rinse solution)
In the preparation of the rinse solution, a 48% NaOH aqueous solution (manufactured by Wako Pure Chemical Industries, Ltd.) was dropped into 500 ml of pure water while stirring to obtain a predetermined pH. Next, a predetermined amount of a compound having a deodorizing ability described in Table 1 below and a water-miscible solvent were added.
Thereafter, lauric acid amidopropyl dimethylamine oxide (Sofudazoline LAO, manufactured by Kawaken Fine Chemical Co., Ltd.) as a surfactant was further added by 5% by weight of the total amount and stirred for 30 minutes to prepare a rinse solution.

[Rinse process]
Each rinse solution prepared on each plate material engraved by the above method was dropped with a dropper (1 mL / cm ² ) so that the plate surface was evenly wetted, and allowed to stand for 1 minute, and then a toothbrush (made by Lion Corporation, And rubbed 20 times (30 seconds) in parallel with the plate with a load of 200 gf. Thereafter, the plate surface was washed with running water, the moisture on the plate surface was removed, and the plate surface was naturally dried for about 1 hour to obtain rinsed plates of Examples 1 to 17 and Comparative Examples 1 and 2.

(Evaluation)
<Resistance removal>
The surface of the rinsed plate was observed with a microscope having a magnification of x100 (manufactured by Keyence Corporation), and the remaining residue on the plate was evaluated. The evaluation criteria are as follows.
×: Adhered to the entire surface of the plate Δ: Slight residue remains on the convex portion of the plate image, and residue remains on the bottom (recessed portion) of the image ○ △: Slight residue remains on the convex portion of the plate image, Further, a slight residue remains on the bottom (recess) of the image. ○: Only a slight residue remains on the bottom (recess) of the image. ○ ◎: No residue remains on the plate.

<Odor>
The printing plate precursor during laser engraving by the above-described method was subjected to sensory evaluation by smelling odor, and the odor level was evaluated as follows. The results are shown in Table 1.
Six professional panelists evaluated the following evaluation criteria (evaluation points).
Evaluation criteria (evaluation points):
◎: About 5 out of 6 people recognized that there was no problem about odor ○: 4 or more about 6 people recognized that there was no problem about odor △: 3 or more about 6 people recognized that there was no problem about odor X: Less than 2 out of 6 people recognized that there was no problem with odor. If the evaluation score is Δ or more, there is no problem in practical use.

  The results are shown in the table below.

  As shown in Table 1, it was confirmed that an unpleasant odor was suppressed by the addition of a compound having a deodorizing ability to the rinse liquid.

Claims (12)

A rinsing solution for relief printing plate making, comprising a compound having a deodorizing ability.   The rinsing solution for relief printing plate making according to claim 1, wherein the compound having deodorizing ability contains polyphenols.   The rinsing liquid for relief printing plate making according to claim 2, wherein the polyphenols contain a catechol residue and / or a pyrogallol residue.   The rinsing liquid for relief printing plate making according to claim 2 or 3, wherein the polyphenol is catechin and / or a derivative thereof.   The rinsing liquid for relief printing plate making according to any one of claims 1 to 4, wherein the compound having deodorizing ability contains a cyclic oligosaccharide.   The rinsing solution for relief printing plate making according to claim 5, wherein the cyclic oligosaccharide is cyclodextrin.   The rinse liquid for relief printing plate making as described in any one of Claims 1-6 which contains 0.01 to 10weight% of the compound which has the said deodorizing ability with respect to the total weight of a rinse liquid.   The rinsing liquid for relief printing plate making according to any one of claims 1 to 7, wherein the compound having the deodorizing ability is contained in an amount of 0.1% by weight or more and 1% by weight or less based on the total weight of the rinsing liquid.   The rinsing liquid for relief printing plate making according to any one of claims 1 to 8, wherein the pH of the rinsing liquid is 8 or more.   The rinsing liquid for relief printing plate making according to any one of claims 1 to 9, comprising a water-miscible solvent in an amount of 0.1 wt% to 10 wt% based on the total weight of the rinsing liquid.   The rinsing solution for relief printing plate making according to claim 10, wherein the water-miscible solvent is alcohol. Preparing a relief printing plate precursor having a relief forming layer;
Engraving the relief printing plate precursor by exposure; and
A process of removing engraving residue generated by engraving with a rinse liquid in this order,
The rinsing liquid is the rinsing liquid for relief printing plate making according to any one of claims 1 to 11, wherein the plate making method of a relief printing plate is characterized in that