JP2009298109A - Laser-engravable relief printing plate original plate, relief printing plate, and method of manufacturing relief printing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser-engravable relief printing plate original plate having a sufficiently high engraving sensibility, capable of being directly laser-engraved to make a plate, and capable of suppressing an unpleasant odor which is generated at that time, a method of manufacturing a relief printing plate using the relief printing plate original plate, and a relief printing plate obtained by the manufacturing method. <P>SOLUTION: The laser-engravable relief printing plate original plate a relief forming layer at least containing a polyfunctional polymerizable compound (A) having an ethylenic unsaturated bond, a binder polymer (B), and a fragrant material (C). The relief printing plate, and the method of manufacturing the relief printing plate are also provided. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

  As a method for forming a printing plate by forming irregularities on a photosensitive resin layer laminated on a surface area of a support, a relief forming layer formed using a photosensitive composition is exposed to ultraviolet light through an 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 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 film, and development processing are required. Methods that do not and are being studied.

In recent years, a method of making a relief forming layer by scanning exposure without using an original film has been studied.
As a technique that does not require an original image film, a relief printing plate precursor provided with 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. Is also possible.
However, high energy is required to form a relief having irregularities that can withstand printing pressure on a relief forming layer having a predetermined thickness, and the speed of laser engraving is slow, so compared to the type that forms an image through a mask, There is a problem of low productivity.

  For this reason, attempts have been made to improve the sensitivity of the relief original plate. For example, a flexographic printing plate precursor for laser engraving including an elastomer foam has been proposed (see, for example, Patent Document 3). In this technology, low-density foam is used for the relief forming layer to improve the engraving sensitivity. However, because it is a low-density material, the strength of the printing plate is insufficient and the printing durability is significantly impaired. There is a problem of being.

  Further, for example, Patent Documents 4 to 6 disclose flexographic printing plate precursors capable of laser engraving or flexographic printing plates 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 plate. There is a problem that an unpleasant odor such as scorching is generated.

Moreover, the problem of the direct engraving CTP method is that the laser engraving speed is low. In the mask CTP method, the thickness of the mask layer element to be ablated is about 1 to 10 μm, whereas in the direct engraving CTP method, it is necessary to engrave at least 100 μm in order to directly form a relief. Because.
Therefore, some proposals for improving the laser engraving sensitivity have been made as follows.

For example, a flexographic printing plate precursor for laser engraving including an elastomer foam has been proposed (see, for example, Patent Document 7). In this technology, the engraving sensitivity is improved by using a foam having a low density. However, since it is a low density material, the strength as a printing plate is insufficient, and the printing durability is remarkably impaired. is there.
For example, a flexographic printing plate precursor for laser engraving that contains a microsphere encapsulating a hydrocarbon-based gas has been proposed (see, for example, Patent Document 8). In this technology, the gas in the microspheres expands due to the heat generated by the laser, and the engraving sensitivity is improved by a system that disintegrates the material to be engraved. There is a problem that the strength tends to be insufficient. In addition, gas is more easily expanded by heat than solids, and even if a microsphere with a high thermal deformation start temperature is selected, volume change due to changes in external temperature cannot be avoided. However, it is not suitable to use a material containing air bubbles in a printing plate that requires the above.
For example, a resin relief printing plate for laser engraving containing a polymer filler having a ceiling temperature of less than 600 degrees K has been proposed (see, for example, Patent Document 9). In this technology, the engraving sensitivity is improved by adding a polymer filler having a low depolymerization temperature. However, when such a polymer filler is used, the surface of the printing plate precursor is uneven, There is a problem of seriously affecting the print quality.

  In addition, as a technique for suppressing an unpleasant odor generated when subjected to laser engraving, for example, a polymer composition containing a polymer containing 45% by mass or more of ethylene units as a repeating unit and an organic peroxide. There has been proposed a flexographic printing plate characterized in that it is made of a polymer material for laser processing formed by cross-linking (see, for example, Patent Document 10). According to this flexographic printing plate, the odor from the polymer material can be improved.

As described above, various techniques have been proposed for the relief forming layer of the relief printing plate precursor for laser engraving. The current situation is that almost no suppression has been provided.
Japanese Patent No. 2773847 JP-A-9-171247 JP 2002-357907 A Japanese Patent No. 2846954 JP 11-338139 A JP-A-11-170718 JP 2000-318330 A US Patent Application Publication No. 2003/180636 JP 2000-168253 A Japanese Patent Laid-Open No. 2002-3665

This invention makes it a subject to achieve the following objectives.
That is, an object of the present invention is to provide a relief printing plate precursor for laser engraving, which has sufficiently high engraving sensitivity, can be directly made by laser engraving, and can suppress unpleasant odors generated at that time, and the relief printing The object is to provide a method for producing a relief printing plate using a plate precursor and a relief printing plate obtained by the production method.

Means for solving the above-mentioned problems are as follows.
The relief printing plate precursor for laser engraving of the present invention has a relief forming layer containing at least (A) a polymerizable compound having an ethylenically unsaturated bond, (B) a binder polymer, and (C) a fragrance. And

In the relief printing plate precursor for laser engraving of the present invention, (A) the polymerizable compound having an ethylenically unsaturated bond is preferably a compound having a sulfur atom in the molecule.
Moreover, it is preferable that (C) fragrance | flavor contains a natural fragrance | flavor and it is also preferable that a synthetic | combination fragrance | flavor is included.
Furthermore, (C) the fragrance preferably contains an ester compound, and preferably contains a terpene compound.
In addition, the relief forming layer in the present invention preferably further contains (D) a photothermal conversion agent capable of absorbing light having a wavelength of 700 nm to 1300 nm.
In addition, the relief forming layer in the relief printing plate precursor for laser engraving of the present invention is preferably cured by at least one of light and heat.

The method for producing a relief printing plate of the present invention comprises (1) a step of crosslinking the relief forming layer in the relief printing plate precursor for laser engraving of the present invention by at least one of light and heat, and (2) formation of a crosslinked relief. A step of laser engraving the layer to form a relief layer.
Further, the step (1) is preferably a step of crosslinking the relief forming layer with heat.

The relief printing plate of the present invention has a relief layer produced by the method for producing a relief printing plate of the present invention.
In the relief printing plate of the present invention, the thickness of the relief layer is preferably from 0.05 mm to 10 mm, and the Shore A hardness of the relief layer is preferably from 50 ° to 90 °.

  According to the present invention, a relief printing plate precursor for laser engraving that has sufficiently high engraving sensitivity, can be directly made by laser engraving, and can suppress unpleasant odors generated at that time, and the relief printing plate precursor It is possible to provide a method for producing a relief printing plate using, and a relief printing plate obtained by the production method.

  Hereinafter, the relief printing plate precursor for laser engraving, the relief printing plate, and the method for producing the relief printing plate of the present invention will be described in detail.

[Relief printing plate precursor for laser engraving]
The relief printing plate precursor for laser engraving of the present invention has a relief forming layer containing at least (A) a polymerizable compound having an ethylenically unsaturated bond, (B) a binder polymer, and (C) a fragrance.
Hereinafter, the relief printing plate precursor for laser engraving of the present invention is also simply referred to as “the relief printing plate precursor of the present invention”.

The relief printing plate precursor of the present invention has sufficiently high engraving sensitivity when subjected to laser engraving and can perform laser engraving at high speed, so that the engraving time can be shortened, and also during laser engraving. The unpleasant odor which generate | occur | produces can be suppressed.
Hereinafter, each component constituting the relief forming layer will be described.

<(A) Polymerizable compound having an ethylenically unsaturated bond>
The relief forming layer in the present invention contains (A) a polymerizable compound having an ethylenically unsaturated bond.
The polymerizable compound having an ethylenically unsaturated bond used in the present invention (hereinafter sometimes simply referred to as “polymerizable compound”) has at least one ethylenically unsaturated double bond, preferably two or more. More preferably, it can be arbitrarily selected from 2 to 6 compounds.

Hereinafter, the monofunctional monomer which has one ethylenically unsaturated double bond in a molecule | numerator used as a polymeric compound, and the polyfunctional monomer which has 2 or more of the said bonds in a molecule | numerator are demonstrated.
In the relief forming layer in the present invention, 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.

  Specific examples of esters of polyhydric alcohol compounds and unsaturated carboxylic acids include acrylic acid esters such as ethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butanediol diacrylate, and tetramethylene glycol diacrylate. , Propylene glycol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane tri (acryloyloxypropyl) ether, trimethylolethane triacrylate, hexanediol diacrylate, 1,4-cyclohexanediol diacrylate, tetra Ethylene glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, Taerythritol tetraacrylate, dipentaerythritol diacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate, tri (acryloyloxyethyl) isocyanurate, polyester Examples include acrylate oligomers.

  Methacrylic acid esters include tetramethylene glycol dimethacrylate, triethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, Hexanediol dimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol dimethacrylate, dipentaerythritol hexamethacrylate, dipentaerythritol pentamethacrylate, sorbitol trimethacrylate, sorbitol tetramethacrylate, bis [p (3-methacryloxy-2-hydroxypropoxy) phenyl] dimethyl methane, bis - [p- (methacryloxyethoxy) phenyl] dimethyl methane.

  Itaconic acid esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate, 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate And sorbitol tetritaconate.

Examples of crotonic acid esters include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, and sorbitol tetradicrotonate.
Examples of isocrotonic acid esters include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate.

Examples of maleic acid esters include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate.
Furthermore, the mixture of the above-mentioned ester monomer can also be mentioned.

  Specific examples of amide monomers of polyvalent amine compounds and unsaturated carboxylic acids include methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, 1,6-hexamethylene bis-methacrylic. Examples include amide, diethylenetriamine trisacrylamide, xylylene bisacrylamide, and xylylene bismethacrylamide.

Further, urethane acrylates as described in JP-A-51-37193, JP-A-48-64183, JP-B-49-43191 and JP-B-52-30490 are described. Polyfunctional acrylates and methacrylates such as polyester acrylates and epoxy acrylates obtained by reacting an epoxy resin with (meth) acrylic acid can be given. Furthermore, Journal of Japan Adhesion Association Vol. 20, no. 7, pages 300 to 308 (1984), those introduced as photocurable monomers and oligomers can also be used.
Specifically, NK oligo U-4HA, U-4H, U-6HA, U-6ELH, U-108A, U-1084A, U-200AX, U-122A, U-340A, U-324A, UA-100 (Above, Shin-Nakamura Chemical Co., Ltd.), UA-306H, AI-600, UA-101T, UA-101I, UA-306T, UA-306I (above, manufactured by Kyoeisha Yushi), Art Resin UN-9200A, UN-3320HA , UN-3320HB, UN-3320HC, SH-380G, SH-500, SH-9832 (manufactured by Negami Industrial Co., Ltd.), PLEX6661-O (manufactured by Degussa, Germany), and the like.

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

The functional group containing a carbon-sulfur bond in the sulfur-containing polyfunctional monomer in the present invention includes sulfide, disulfide, sulfoxide, sulfonyl, sulfonamide, thiocarbonyl, thiocarboxylic acid, dithiocarboxylic acid, sulfamic acid, thioamide, and thiocarbamate. , Functional groups containing dithiocarbamate or thiourea.
From the viewpoint of engraving sensitivity, a functional group containing disulfide, thiocarbamate, or dithiocarbamate is preferred, and a functional group containing disulfide is more preferred.
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-, -C-SS-, -NH (C = S) It is preferably at least one unit selected from O—, —NH (C═O) S—, —NH (C═S) S—, and —C—SO ₂ —. From the viewpoint of increasing, -C-SS-, -NH (C = S) O-, -NH (C = O) S-, -NH (C = S) S-ga are preferred, and -C-SS- is the most preferable.

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

As the ethylenically unsaturated site contained in the sulfur-containing polyfunctional monomer, for example, a partial structure represented by any one of the following general formulas (1) to (5) is preferable, but the degradability viewpoint of the polymer is preferable. Therefore, the partial structure represented by any one of the general formulas (1) to (3) is preferable, and the partial structure represented by the general formula (1) is more preferable.
In the sulfur-containing polyfunctional monomer in the present invention, two or more of the same types of partial structures of the following general formulas (1) to (5) may be present in one molecule, or different types. Two or more things may exist.

First, general formulas (1) to (3) will be described.
In general formulas (1) to (3), R ^{1 to} R ¹¹ each independently represents a hydrogen atom or a monovalent substituent. X and Y each independently represent an oxygen atom, a sulfur atom, —N—R ^a —, or a sulfonyl group, and Z represents an oxygen atom, a sulfur atom, —N—R ^a —, a sulfonyl group, or a phenylene group. Represents. Here, R ^a represents a hydrogen atom or a monovalent organic group.

In the general formula (1), R ^{1 to} R ³ each independently represent a hydrogen atom or a monovalent substituent.
Examples of R ¹ include a hydrogen atom or an organic group such as an alkyl group which may have a substituent. Among them, a hydrogen atom, a methyl group, a methylalkoxy group, and a methyl ester group are specifically preferable.
R ² and R ³ each independently have a hydrogen atom, a halogen atom, an amino group, a dialkylamino group, a carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, or a substituent. A good alkyl group, an aryl group which may have a substituent, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, an alkylamino group which may have a substituent, An arylamino group which may have a substituent, an alkylsulfonyl group which may have a substituent, an arylsulfonyl group which may have a substituent, and the like are mentioned. Among them, a hydrogen atom, a carboxyl group, alkoxycarbonyl A group, an alkyl group which may have a substituent, and an aryl group which may have a substituent are preferable. Here, examples of the substituent that can be introduced into these groups include a methoxycarbonyl group, an ethoxycarbonyl group, an isopropyloxycarbonyl group, a methyl group, an ethyl group, and a phenyl group.
X is preferably an oxygen atom, a sulfur atom, or —N—R ^a —, and examples of R ^a include an alkyl group that may have a substituent.

In the general formula (2), R ^{4 to} R ⁸ each independently represents a hydrogen atom or a monovalent substituent.
Examples of R ^{4 to} R ⁸ include a hydrogen atom, a halogen atom, an amino group, a dialkylamino group, a carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, and an alkyl group that may have a substituent, An aryl group that may have a substituent, an alkoxy group that may have a substituent, an aryloxy group that may have a substituent, an alkylamino group that may have a substituent, and a substituent. An arylamino group which may have a substituent, an alkylsulfonyl group which may have a substituent, an arylsulfonyl group which may have a substituent, and the like. Among them, a hydrogen atom, a carboxyl group, an alkoxycarbonyl group, a substituent An alkyl group which may have a substituent and an aryl group which may have a substituent are preferable. Here, examples of the substituent that can be introduced into these groups include those exemplified as the substituent that can be introduced in the general formula (1).
Y is preferably an oxygen atom, a sulfur atom, or —N—R ^a —, and examples of R ^a include the same as those in the general formula (1).

In the general formula (3), R ^{9 to} R ¹¹ each independently represent a hydrogen atom or a monovalent substituent.
Specific examples of R ^{9 to} R ¹¹ include a hydrogen atom, a halogen atom, an amino group, a dialkylamino group, a carboxyl group, an alkoxycarbonyl group, a sulfo group, a nitro group, a cyano group, and a substituent. An alkyl group which may have a substituent, an aryl group which may have a substituent, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, an alkylamino group which may have a substituent , An arylamino group which may have a substituent, an alkylsulfonyl group which may have a substituent, an arylsulfonyl group which may have a substituent, and the like. Among them, a hydrogen atom, a carboxyl group, an alkoxy A carbonyl group, an alkyl group which may have a substituent, and an aryl group which may have a substituent are preferable. Here, examples of the substituent that can be introduced into these groups include those exemplified as the substituent that can be introduced in the general formula (1).
Z is preferably an oxygen atom, a sulfur atom, —N—R ^a —, or a phenylene group, and examples of R ^a include the same as those in the general formula (1).

In addition, the sulfur-containing polyfunctional monomer in the present invention includes a linking group L connecting the ethylenically unsaturated sites in addition to the partial structure represented by any one of the general formulas (1) to (3). Here, L represents a divalent or higher linking group containing a carbon-sulfur bond. From the viewpoint of thermal decomposability, the linking group L preferably has an ester bond in addition to the carbon-sulfur bond, and more preferably has an ester bond and a hydroxyl group at the same time.
Examples of the functional group having a carbon-sulfur bond contained in the linking group L include sulfide, disulfide, sulfoxide, sulfonyl, sulfonamide, thiocarbonyl, thiocarboxylic acid, dithiocarboxylic acid, sulfamic acid, thioamide, thiocarbamate, dithiocarbamate, or Examples include functional groups containing thiourea. From the viewpoint of engraving sensitivity, a functional group containing disulfide, thiocarbamate, or dithiocarbamate is preferred, and a functional group containing disulfide is more preferred.
In addition, the linking group L preferably contains a hydrocarbon group in addition to the functional group having a carbon-sulfur bond, and more preferably has a total carbon number of 1 to 10. Especially, it is preferable that the connection group L contains what the some C1-C6 hydrocarbon group connected via structures other than hydrocarbon groups, such as ester. As a hydrocarbon group, a C1-C6 alkylene group, a phenylene group, etc. are preferable. Examples of the structure other than the hydrocarbon group constituting the linking group L include an ester bond, an amide bond, a urea bond, a urethane bond, an ether bond, and a carbonyl group. Preferred are esters. Further, this hydrocarbon group may be appropriately substituted with a monovalent substituent, and as the substituent, a hydroxyl group, a thiol group, an amino group, a carboxyl group, a cyano group, a nitro group, or the like is preferably used. In particular, the hydrocarbon group constituting the linking group L is preferably a hydrocarbon group substituted with a hydroxyl group. The linking group L preferably has a structure containing 1 to 5 hydrocarbon groups per ethylenically unsaturated bond.

Specific examples of preferable sulfur-containing polyfunctional monomers having a partial structure represented by any one of the general formulas (1) to (3) are shown below, but the present invention is not limited thereto.
Moreover, R in the following specific examples represents a hydrogen atom or a methyl group, and a plurality of Rs present in the molecule may be the same or different.

  Next, partial structures represented by the following general formulas (4) and (5) will be described.

In the general formula (4), R ¹² represents a hydrogen atom or a methyl group.
R ¹³ represents any substitutable atom or atomic group.
k represents an integer of 0 to 4.

In the general formula (5), R ¹⁴ represents a hydrogen atom or a methyl group.
R ¹⁵ represents any substitutable atom or atomic group.
m represents an integer of 0 to 4.
A ⁻ represents a counter anion.
In addition, such a pyridinium ring may take the form of benzopyridinium condensed with benzene by bonding two R ¹⁵ to form a benzene ring, and in this case, includes a quinolium group and an isoquinolium group.

The atoms or atomic groups represented by R ¹³ and R ¹⁵ each independently have a halogen atom, amino group, dialkylamino group, carboxyl group, alkoxycarbonyl group, sulfo group, nitro group, cyano group, or substituent. An alkyl group which may have a substituent, an aryl group which may have a substituent, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, an alkyl which may have a substituent Examples include an amino group, an arylamino group which may have a substituent, an alkylsulfonyl group which may have a substituent, an arylsulfonyl group which may have a substituent, among others, a carboxyl group, an alkoxycarbonyl A group, an alkyl group which may have a substituent, and an aryl group which may have a substituent are preferable. Here, examples of the substituent that can be introduced into these groups include a methoxycarbonyl group, an ethoxycarbonyl group, an isopropyloxycarbonyl group, a methyl group, an ethyl group, and a phenyl group.

In addition, as a counter anion represented by A ⁻ , F ⁻ , Cl ⁻ , Br ⁻ , I ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , BAr ₄ ⁻ (Ar is an arbitrary Represents an aryl group optionally substituted by several fluorine atoms or CF ₃ , and four Ars may be the same or different from each other.), CF ₃ SO ₃ ⁻ , p-CH ₃ C ₆ H ₄ SO ₃ ⁻ , CH ₃ SO ₃ ⁻ and CF ₃ COO ⁻ can be mentioned.

  Here, in addition to the partial structure represented by the general formula (4) or (5), the sulfur-containing polyfunctional monomer in the present invention includes a linking group L that connects the ethylenically unsaturated sites. This connecting group L is synonymous with the above-mentioned connecting group L, and its preferable example is also the same.

Although a preferable example is shown below as a sulfur-containing polyfunctional monomer which has a partial structure represented by General formula (4) or (5) below, this invention is not limited to these.
Moreover, R in the following specific examples represents a hydrogen atom or a methyl group, and a plurality of Rs present in the molecule may be the same or different.

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

  The molecular weight of the sulfur-containing polyfunctional monomer in the present invention is preferably 120 to 3000, more preferably 120 to 1500, from the viewpoint of the flexibility of the formed film.

Moreover, although the sulfur-containing polyfunctional monomer in this invention may be used independently, you may use it as a mixture with the polyfunctional polymerizable compound and monofunctional polymerizable compound which do not have a sulfur atom in a molecule | numerator.
From the viewpoint of engraving sensitivity, it is preferable to use a sulfur-containing polyfunctional monomer alone or as a mixture of a sulfur-containing polyfunctional monomer and a monofunctional ethylenic monomer, more preferably a sulfur-containing polyfunctional monomer and a monofunctional. This is an embodiment used as a mixture with an ethylenic monomer.

The relief forming layer in the present invention can adjust film physical properties such as brittleness and flexibility by using a polymerizable compound including a sulfur-containing polyfunctional monomer.
In addition, the total content of polymerizable compounds including the sulfur-containing polyfunctional monomer in the relief forming layer in the present invention is preferably in the range of 5% by mass to 90% by mass from the viewpoint of flexibility and brittleness of the crosslinked film. 10 mass%-75 mass% is more preferable, 10 mass%-60 mass% is still more preferable, and the range of 15 mass%-40 mass% is especially preferable.
In addition, when using together a sulfur-containing polyfunctional monomer and another polymeric compound, 5 mass% or more is preferable and, as for the quantity of the sulfur-containing polyfunctional monomer in all the polymeric compounds, 10 mass% or more is more preferable.

<(B) Binder polymer>
The relief forming layer in the present invention contains (B) a binder polymer.
The (B) binder polymer used in the present invention is a main component contained in the relief forming layer, and usually a thermoplastic resin, a thermoplastic elastomer, or the like is used depending on the purpose.
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.
For example, when the purpose is to form a soft and flexible film, a soft resin or a thermoplastic elastomer is selected.
Furthermore, it is preferable to use a hydrophilic or alcoholic polymer from the viewpoint of easy preparation of the coating composition for the relief forming layer and improvement in resistance to the oil-based ink in the obtained relief printing plate.
In addition, for example, 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 selected as the binder polymer.
In this way, in consideration of the physical properties according to the application application of the relief printing plate precursor, a binder polymer can be selected according to the purpose, and one kind of the binder polymer or a combination of two or more kinds can be used.
Hereinafter, various polymers that can be used as the binder polymer in the present invention will be described.

(Degradable polymer)
Examples of the binder polymer that is preferably used from the viewpoint of laser engraving sensitivity include polymers having a partial structure that decomposes upon application of energy such as exposure and heating (polymer having decomposability).

  Examples of degradable polymers include styrene, α-methylstyrene, α-methoxystyrene, acrylic esters, methacrylic esters, and esters other than the above as monomer units having a partial structure that is easily decomposed and cleaved in the molecular chain. Examples include polymers containing compounds, ether compounds, nitro compounds, carbonate compounds, carbamoyl compounds, hemiacetal ester compounds, oxyethylene compounds, aliphatic cyclic compounds, and the like.

Among these, in particular, polyethers such as polyethylene glycol, polypropylene glycol, polytetraethylene glycol, aliphatic polycarbonates, aliphatic carbamates, polymethyl methacrylate, polystyrene, nitrocellulose, polyoxyethylene, polynorbornene, polycyclohexane. A polymer having a molecular structure such as a hydrogenated hexadiene or a dendrimer having many branched structures is preferred from the viewpoint of degradability.
A polymer containing a large number of oxygen atoms in the molecular chain is preferred from the viewpoint of degradability. From such a viewpoint, a compound having a carbonate group, a carbamate group, or a methacryl group in the polymer main chain is preferable.
For example, polyesters and polyurethanes synthesized from (poly) carbonate diol or (poly) carbonate dicarboxylic acid as raw materials, polyamides synthesized from (poly) carbonate diamine as raw materials, and the like can be cited as examples of polymers having good thermal decomposability. . These polymers may contain a polymerizable unsaturated group in the main chain and side chain. In particular, when it has a reactive functional group such as a hydroxyl group, an amino group, or a carboxyl group, it is easy to introduce a polymerizable unsaturated group into such a thermally decomposable polymer.

  Moreover, polyester which consists of hydroxyl carboxylic acid units, such as polylactic acid, can be used as a polymer which has decomposability | degradability. 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.

(Thermoplastic polymer)
One of the binder polymers preferably used from the viewpoint of laser engraving sensitivity is a thermoplastic polymer.
The thermoplastic polymer may be an elastomer or a non-elastomeric resin, and may be selected according to the use mode of the relief printing plate precursor of the present invention.
Examples of the thermoplastic elastomer include urethane-based thermoplastic elastomers, ester-based thermoplastic elastomers, amide-based thermoplastic elastomers, and silicone-based thermoplastic elastomers. In order to improve the laser engraving sensitivity of these thermoplastic elastomers, those obtained by introducing easily decomposable functional groups such as carbamoyl groups and carbonate groups into the main chain of the elastomers can also be used. Moreover, you may mix and use a thermoplastic polymer and the said thermodegradable polymer.
Thermoplastic elastomer is a material that exhibits rubber elasticity at room temperature, and its molecular structure consists of a soft segment such as polyether or rubber molecule, and a hard segment that prevents plastic deformation at around room temperature, just like vulcanized rubber, There are various types of hard segments such as a frozen phase, a crystalline phase, a hydrogen bond, and an ionic bridge. Such a thermoplastic elastomer is suitable when the relief printing plate precursor of the present invention requires flexibility such as a flexographic plate.

  The type of thermoplastic elastomer is selected according to the purpose.For example, when solvent resistance is required, urethane type, ester type, amide type, fluorine type thermoplastic elastomer is preferable, and when heat resistance is required, Urethane-based, olefin-based, ester-based, and fluorine-based thermoplastic elastomers are preferred. Moreover, the hardness of a relief forming layer can be changed greatly by selecting the kind of thermoplastic elastomer.

  Non-elastomeric resins include, for example, polyester resin, unsaturated polyester resin, polyamide resin, polyamideimide resin, polyurethane resin, unsaturated polyurethane resin, polysulfone resin, polyethersulfone resin, polyimide resin, polycarbonate resin, wholly aromatic Mention may be made of polyester resins and hydrophilic polymers containing hydroxyethylene units (for example polyvinyl alcohol derivatives).

(Hydrophilic or alcoholic polymer)
As the binder polymer used in the present invention, a hydrophilic polymer or an alcoholic polymer is preferable from the viewpoint of removal of residue after engraving. Specific examples of the hydrophilic polymer include those described later, and among them, a hydrophilic polymer containing a hydroxyethylene unit is preferable. As the hydrophilic or alcoholic binder, for example, a polymer such as polyvinyl butyral can be suitably used.

The hydrophilic polymer which is one of the preferred embodiments of the binder polymer will be described in detail.
The hydrophilic polymer refers to a water-soluble or water-swellable polymer. Here, in the present invention, “water solubility” means that 5% by mass or more is dissolved in water at 25 ° C., and “water swellability” is 5% by mass in water at 25 ° C. When added in such a manner, it absorbs water and expands, and when it is visually observed, it does not dissolve, but it indicates that there is no clear solid (powder) precipitate.

  As the hydrophilic polymer, a single polymer may be used, or a plurality of types of polymers may be used.

  Examples of the hydrophilic polymer include hydrophilic polymers containing hydroxyethylene units, polysaccharides having hydrophilic functional groups such as cellulose, and salt structures and amino acids neutralized with acidic functional groups such as sodium polyacrylate. Examples thereof include an acrylic resin containing a salt structure or an onium structure in which the group is neutralized, a polyamide resin or a polyester resin into which a hydrophilic group such as polyethylene oxide is introduced, gelatin, and the like.

  Hydrophilic polymers include hydrophilic polymers containing hydroxyethylene, polar groups such as amino groups or carboxylic acid groups / sulfonic acid groups / sulfuric acid groups, and salt structures in which these are neutralized in that they exhibit good hydrophilicity. Cellulose, amino group or polar group-containing acrylic resin such as carboxylic acid group / sulfonic acid group / sulfuric acid group and salt structure in which these are neutralized, and polyamide resin are preferred. More preferably, hydrophilic polymers containing hydroxyethylene, polar groups-containing acrylic resins such as amino groups or carboxylic acid groups / sulfonic acid groups / sulfuric acid groups and salt structures in which these are neutralized, and polyamide resins are more preferable. Polyvinyl alcohols and polyamide resins.

  Particularly preferred as the hydrophilic polymer is a polymer selected from polyvinyl alcohol (PVA) and derivatives thereof from the viewpoint of film property and resistance to UV ink.

In the present invention, PVA and derivatives thereof are co-polymers containing 0.1 to 100 mol% of hydroxyethylene units, preferably 1 to 98 mol%, more preferably 5 to 95 mol%. Polymers or polymers and their modified products are included.
The monomer for forming the copolymer together with the vinyl alcohol structural unit can be appropriately selected from known copolymerizable monomers.
Among PVA and its derivatives, PVA and vinyl alcohol / vinyl acetate copolymer (partially saponified polyvinyl alcohol) can be exemplified, and these modified products also correspond to this.

  As the hydrophilic polymer, in particular, one or more selected from PVA and derivatives thereof and a hydrophilic polymer not containing a hydroxyethylene unit (hereinafter also referred to as “non-PVA derivative” as appropriate) may be used in combination. Good.

Examples of the method for synthesizing the hydrophilic polyamide include the following.
A polyamide having a polyethylene glycol unit is obtained by reacting ε-caprolactam and / or adipic acid with polyethylene glycol modified with both terminal amines, and a hydrophilic polyamide having a piperazine skeleton is obtained by reacting with piperazine. Moreover, the hydrophilic polyamide by which the crosslinkable functional group was introduce | transduced into the polymer is obtained by making the amide group of hydrophilic polyamide and the epoxy group of glycidyl methacrylate react. These non-PVA derivatives may be used alone or in combination of two or more.

  Examples of PVA derivatives include polymers in which at least some of the hydroxyl groups of the hydroxyethylene units have been modified to carboxyl groups, polymers in which some of the hydroxyl groups have been modified to (meth) acryloyl groups, and at least some of the hydroxyl groups have been modified to amino groups. And a polymer in which ethylene glycol, propylene glycol, or a multimer thereof is introduced into at least a part of the hydroxyl group.

  A polymer in which at least a part of the hydroxyl group is modified to a carboxyl group can be obtained by esterification with polyvinyl alcohol or partially saponified polyvinyl alcohol and a polyfunctional carboxylic acid such as succinic acid, maleic acid or adipic acid. . The amount of the carboxyl group introduced in the polymer is preferably 0.01 mol to 1.00 mol, more preferably 0.05 mol to 0.80 mol, per 1 mol of the hydroxyl group.

  A polymer in which at least a part of the hydroxyl group is modified to a (meth) acryloyl group can be obtained by adding glycidyl (meth) acrylate to the carboxyl group-modified polymer, or by adding polyvinyl alcohol or partially saponified polyvinyl alcohol and (meth) acrylic acid. It can be obtained by esterification. The amount of (meth) acryloyl group introduced in the polymer is preferably 0.01 mol to 1.00 mol, more preferably 0.03 mol to 0.50 mol, per mol of the hydroxyl group. In addition, the description with a (meth) acryloyl group is a general term for an acryloyl group and / or a methacryloyl group. The notation (meth) acrylate is a generic term for acrylate and / or methacrylate. The same applies to (meth) acrylic acid and the like.

  A polymer in which at least a part of the hydroxyl group is modified with an amino group can be obtained by esterification with polyvinyl alcohol or partially saponified polyvinyl alcohol and a carboxylic acid containing an amino group such as carbamic acid. The amount of amino group introduced in the polymer is preferably 0.01 mol to 1.00 mol, more preferably 0.05 mol to 0.70 mol, relative to 1 mol of the hydroxyl group.

  Polymers in which ethylene glycol, propylene glycol, or a multimer thereof is introduced into at least a part of the hydroxyl groups are heated with polyvinyl alcohol or partially saponified polyvinyl alcohol and glycols under a sulfuric acid catalyst to react with water as a by-product. It can be obtained by removing it outside the system. The total introduction amount of ethylene glycol, propylene glycol and their multimers in the polymer is preferably 0.01 mol to 0.90 mol, more preferably 0.03 mol to 0.50 mol, relative to 1 mol of the hydroxyl group. .

  Among the modified PVA derivatives, a polymer in which at least a part of the hydroxyl group is modified to a (meth) acryloyl group is particularly preferably used. By directly introducing an unreacted crosslinkable functional group into the hydrophilic polymer, the strength of the crosslinked product when the relief forming layer is crosslinked can be increased without using a large amount of the above-mentioned sulfur-containing polyfunctional monomer. This is because both the flexibility and strength of the crosslinked product can be achieved. That is, according to this aspect, the relief forming layer of the relief printing plate precursor of the present invention can achieve both flexibility and strength.

Further, the non-PVA derivative means one having a polarity close to the degree of compatibility with PVA and its derivatives.
Specifically, as the non-PVA derivative, for example, hydrophilicity in which a hydrophilic group such as polyethylene glycol or piperazine is introduced into a water-insoluble polyamide obtained by polymerization of only adipic acid, 1,6-hexanediamine, and ε-caprolactam. Include polyamides. A hydrophilic polyamide is suitable for use as a non-PVA derivative because it exhibits compatibility with the PVA derivative by the action of the hydrophilic group. In other words, such a hydrophilic polyamide has good compatibility with PVA and its derivatives, and easily enters between the molecules of PVA and its derivatives. Will be flexible.

(Hydrophobic polymer)
As the binder polymer in the present invention, a relatively hydrophobic binder polymer may be used.
In order to adjust properties such as film hardness and flexibility at the time of film formation, compatibility with other components such as a polymerizable compound and an initiator, the relatively hydrophobic binder polymer is shown below. A polymer containing such a monomer as a polymerization or copolymerization component can also be used.
2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, β-hydroxy-β ′-(meth) (Meth) acrylate having a hydroxyl group such as acryloyloxyethyl phthalate, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, isoamyl (meth) acrylate, 2-ethylhexyl (meth) Alkyl (meth) acrylates such as acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, cycloalkyl (meth) acrylates such as cyclohexyl (meth) acrylate, chloroethyl (meth) Alkyl halides (meth) acrylates such as acrylate and chloropropyl (meth) acrylate, alkoxyalkyl (meth) acrylates such as methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, and butoxyethyl (meth) acrylate, phenoxyethyl acrylate Alkoxyalkylene glycols (meth) such as phenoxyalkyl (meth) acrylates such as nonylphenoxyethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate Acrylate, (meth) acrylamide, diacetone (meth) acrylamide, N, N′-methylenebis (meth) acryl (Meth) acrylamides such as amides, 2,2-dimethylaminoethyl (meth) acrylate, 2,2-diethylaminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylamide, N, N-dimethyl Compounds having only one ethylenically unsaturated bond such as aminopropyl (meth) acrylamide, di (meth) acrylate of polyethylene glycol such as diethylene glycol di (meth) acrylate, such as dipropylene glycol di (meth) acrylate Polypropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, glycerol tri (meth) acrylate Such as polyvalent (meth) acrylates and glycidyl (meth) acrylates obtained by addition reaction of compounds with ethylenically unsaturated bonds and active hydrogen, such as unsaturated carboxylic acids and unsaturated alcohols, with ethylene glycol diglycidyl ether Many polyvalent (meth) acrylamides such as polyvalent (meth) acrylates and methylenebis (meth) acrylamides obtained by addition reaction of unsaturated epoxy compounds with compounds having active hydrogen such as carboxylic acids and amines, and divinylbenzene And compounds having two or more ethylenically unsaturated bonds, such as a valent vinyl compound. In this invention, these can be used individually or in combination of 2 or more types.

  From the viewpoint of film property, the monomer of the polymerization component is 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxytrile. Alkoxyalkylene glycol (meth) acrylates such as ethylene glycol (meth) acrylate and methoxydipropylene glycol (meth) acrylate, (meth) acrylamide, diacetone (meth) acrylamide, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, N -Acryloylmorpholine is preferred. Among these, acrylates are particularly preferable from the viewpoint of ensuring flexibility of the obtained polymer.

In addition, the following polymers can also be used as the binder polymer.
That is, a polymer containing at least one of an olefin and a carbon-carbon triple bond in the main chain is exemplified. For example, SB (polystyrene-polybutadiene), SBS (polystyrene-polybutadiene-polystyrene), SIS (polystyrene-polyisoprene-polystyrene). And SEBS (polystyrene-polyethylene / polybutylene-polystyrene).

(Polymer having carbon-carbon unsaturated bond)
As the binder polymer, a polymer having a carbon-carbon unsaturated bond in the molecule can be suitably used. The carbon-carbon unsaturated bond may be present in either the main chain or the side chain of the polymer, and may be present in both. Hereinafter, the carbon-carbon unsaturated bond may be simply referred to as “unsaturated bond”, and the carbon-carbon unsaturated bond remaining at the end of the main chain or side chain may be referred to as “polymerizable group”. .
When having a carbon-carbon unsaturated bond in the main chain of the polymer, it may be present at one end, both ends, or in the main chain of the polymer main chain. Moreover, when it has a carbon-carbon unsaturated bond in the side chain of a polymer, this unsaturated bond may be directly couple | bonded with the principal chain structure, and may be couple | bonded through the suitable coupling group.

  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.

  When a polymer having a highly reactive polymerizable unsaturated group such as a methacryloyl group is used as a polymer having a carbon-carbon unsaturated bond in the side chain, a film having extremely high mechanical strength can be produced. In particular, in polyurethane-based and polyester-based thermoplastic elastomers, it is possible to introduce a highly reactive polymerizable unsaturated group into the molecule relatively easily.

  When an unsaturated bond or a polymerizable group is introduced into the binder polymer, a structural unit having a polymerizable group precursor formed by bonding a protective group to the polymerizable group is copolymerized with the polymer to remove the protective group. Reactive group such as hydroxyl group, amino group, epoxy group, carboxyl group, acid anhydride group, ketone group, hydrazine residue, isocyanate group, isothiocyanate group, cyclic carbonate group, ester group And then reacting a binder having a plurality of groups capable of binding to the reactive group (for example, polyisocyanate in the case of a hydroxyl group or an amino group) to adjust the molecular weight and Is converted to a bonding group, and then reacted with an organic compound having a polymerizable unsaturated group and a group that reacts with the terminal bonding group, and a polymerizable group is obtained by a polymer reaction. A method of introducing, it is possible to take any known method. According to these methods, the amount of unsaturated bond and polymerizable group introduced into the polymer compound can be controlled.

Such a polymer having an unsaturated bond is also preferably used in combination with a polymer having no unsaturated bond. That is, a polymer obtained by adding a hydrogen to the olefin part of the polymer having a carbon-carbon unsaturated bond, or a monomer hydrogenated to the olefin part, for example, a monomer hydrogenated to butadiene, isoprene, or the like as a raw material. Polymers obtained by forming can be used in combination because of their excellent compatibility, and the amount of unsaturated bonds of the binder polymer can be adjusted.
When these are used in combination, the polymer having no unsaturated bond is generally 1 part by mass to 90 parts by mass, preferably 5 parts by mass to 80 parts by mass with respect to 100 parts by mass of the polymer having an unsaturated bond. Can be used in proportions.
As will be described later, in the case where the curing property is not required for the binder polymer, such as when other polymerizable compounds are used in combination, an unsaturated bond is not necessarily required for the binder polymer, and various polymers having no unsaturated bond. Alone can also be used as the binder polymer. Preferred examples of the polymer having no unsaturated bond in such a case include polyester, polyamide, polystyrene, acrylic resin, acetal resin, and polycarbonate.

  The number average molecular weight of the binder polymer having or not having an unsaturated bond that can be used in the present invention is preferably in the range of 10,000 to 1,000,000. A more preferable range is from 50,000 to 500,000. When the number average molecular weight is in the range of 10,000 to 1,000,000, the mechanical strength of the formed film can be ensured. The number average molecular weight is measured using gel permeation chromatography (GPC), and evaluated with respect to a polystyrene sample having a known molecular weight.

  The weight average molecular weight (polystyrene conversion by GPC measurement) of the binder 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 to prepare a coating solution composition for a relief forming layer. Convenient. The weight average molecular weight of the binder polymer is more preferably 10,000 to 400,000, particularly preferably 15,000 to 300,000.

The content of the binder polymer in the relief forming layer is preferably 5% by mass to 80% by mass, preferably 15% by mass to 75% by mass, and more preferably 20% by mass to 65% by mass.
In particular, when the content of the binder polymer is 15% by mass or more, printing durability sufficient to use the obtained relief printing plate as a printing plate can be obtained. The components are not insufficient, and even when a relief printing plate is used as a flexographic printing plate, flexibility sufficient for use as a printing plate can be obtained, which is preferable.

<(C) Fragrance>
The relief forming layer in the present invention contains (C) a fragrance as an essential component. The fragrance is effective for reducing odor during laser engraving.
The fragrance is particularly preferably one that neutralizes or masks the odor derived from the polymerizable compound (A).
As a fragrance | flavor, a well-known fragrance | flavor can be selected suitably and can be used, a fragrance | flavor can also be used individually by 1 type and it can also be used combining a some fragrance | flavor.
The fragrance is preferably appropriately selected depending on the polymerizable compound or solvent used in the relief forming layer, and is preferably optimized by combining known fragrances. Moreover, as a fragrance | flavor, both a natural fragrance | flavor and a synthetic | combination fragrance | flavor can be used.

Natural flavors used in the present invention can be broadly classified into animal flavors and vegetable flavors.
Examples of animal flavors include castrium (sea scented incense), musk (scented scented incense), ambergris (dragon scented incense), and civet (spirit scented incense).
Examples of vegetable flavors include lemon oil, orange oil, lime oil, bergamot oil, eucalyptus oil, mandarin oil, wintergreen oil, camphor oil, pepper oil, oak moss oil, oppoponax oil, copaiba oil, sandals Oil, cedarwood oil, trubalsum oil, perubalsum oil, benzoin oil, vanilla oil, abies fa oil, almond oil, columnus oil, camomil oil, cardamom oil, galvanum oil, caraway oil, cumin oil, coriander oil, juniper Berry oil, spearmint oil, sage oil, celery oil, thyme oil, tarragon oil, nutmeg oil, basil oil, hyssop oil, pettigren oil, butchu oil, penny royal oil, peppermint oil, mace oil, lavender oil, rosemary oil, Lobe oil, laurel oil, amylis oil Elemi oil, Cassia oil, Guayac oil, Clove oil, Stylax oil, Geranium oil, Tangerine oil, Patchouli oil, Vetiver oil, Labdanum oil, Lemongrass oil, Angelica oil, Hinoki oil, Hiba oil, Citronella oil, Anise seed oil, Ylang Ylang Oil, Clarisage Oil, Cinnamon Oil, Star Anise Oil, Cananga Oil, Black Currant Oil, Amblet Seed Oil, Bay Oil, Boad Rose Oil, Kayapte Oil, Cassie Oil, Coriander Oil, Costas Oil, Davana Oil, Dill Oil , Fennel oil, Fenigree oil, Gene oil, Grapefruit oil, Ginger oil, Hop oil, Hyacinth oil, Inmortel oil, Jasmine oil, Jonquil oil, Labandin oil, Linaroe oil, Lycea cubeba oil, Marjoram oil, Mimosa oil, Mill oil, Myrtle oil, Narushi Oil, Olivenham oil, Oris oil, Parsley oil, Palmarosa oil, Pepper oil, Perilla oil, Neroli oil, Orange flower oil, Pimenta oil, Pine oil, Rose oil, Spike lavender oil, Tadget oil, Tonka beans oil, Tuberose oil , Turpentine oil, valerian oil, violet oil, wormwood oil, yuzu oil and the like.

The natural fragrance component can be used without any problem even if it has any shape such as essential oil, absolute, concrete, resinoid and the like.
In addition, depending on the purpose of use, the main component, unique component, or necessary component contained can be fractionated from the natural fragrance and used as a fractionated fragrance. In this case, it can be separated and purified by distillation, recrystallization, chromatography, chemical treatment or the like.

  Synthetic fragrances are classified into fractionated fragrances and chemically synthesized fragrances obtained by separating and purifying active ingredients contained in plant essential oils. The latter is produced by petrochemical products and natural terpene compounds as raw materials, based on organic synthesis processes, by total synthesis, semi-synthesis, and biosynthesis methods. Chemically synthesized fragrances may be those obtained by chemically synthesizing the same active ingredients as natural fragrances, and newly discovered compounds that are not found in natural fragrances but are excellent in fragrance. .

  Focusing on the molecular structure of fragrances, the fragrances include aliphatic hydrocarbons, terpene hydrocarbons, hydrocarbons such as aromatic hydrocarbons, aliphatic alcohols, terpene alcohols, alcohols such as aromatic alcohols, and aliphatic ethers. , Ethers such as aromatic ethers, aliphatic oxides, oxides such as terpene oxides, aliphatic aldehydes, terpene aldehydes, alicyclic aldehydes, aldehydes such as thioaldehydes, aromatic aldehydes, aliphatic ketones , Terpene ketone, alicyclic ketone, aliphatic cyclic ketone, non-benzene aromatic ketone, aromatic ketone and other ketones, acetals, ketals, phenols, phenol ethers, fatty acids, terpene carboxylic acids, fats Acids such as cyclic carboxylic acid and aromatic carboxylic acid, acid amides, aliphatic lactate , Macrocyclic lactones, terpene lactones, alicyclic lactones, aromatic lactones and other lactones, aliphatic esters, furan carboxylic acid esters, aliphatic cyclic carboxylic acid esters, cyclohexyl carboxylic acid esters, terpene carboxylic acids Examples include esters such as acid esters and aromatic carboxylic acid esters, nitrogen-containing compounds such as nitromusks, nitriles, amines, pyridines, quinolines, pyrrole and indole.

Specifically, the hydrocarbons include α-pinene, β-pinene, camphene, myrcene, limonene, terpyrene, osmene, γ-terpinene, α-ferrandylene, p-cymene, β-cariolefin, β-farnesene. 1,3,5-undecatriene, diphenylmethane and the like.
Examples of alcohols include trans-2-hexenol, cis-3-hexenol, 3-octanol, 1-octen-3-ol, 2,6-dimethyl-2-heptanol, 9-decenol, and 4-methyl-3-decene. -5-ol, 10-undecenol, trans-2-cis-6-nonadienol, linalool, geraniol, nerol, citronellol, rosinol, myrsenol, lavandulol, tetrahydrogeraniol, tetrahydrolinalol, hydroxycitronellol, dihydromyrcenol, allo Osimenol, α-terpineol, tarpinen-4-ol, 1-menthol, borneol, isopulegol, nopol, farnesol, nerolidol, bisabolol, cedrol, patchoulialcohol, vetivero 2,4-dimethyl-3-cyclohexene-1-methanol, 4-isopropylcyclohexanol, 4-isopropylcyclohexanemethanol, 1- (4-isopropylcyclohexyl) ethanol, 2,2-dimethyl-3- (3-methylphenyl) ) Propanol, pt-butylcyclohexanol, ot-butylcyclohexanol, ambrinol, 1- (2-tert-butylcyclohexyloxy) -2-butanol, pentamethylcyclohexylpropanol, 1- (2,2, 6-trimethylcyclohexyl) -3-hexanol, benzyl alcohol, phenethyl alcohol, phenoxyethyl alcohol, styryl alcohol, anise alcohol, cinnamic alcohol, phenylpropyl alcohol, dimethylbenz Aliphatic alcohols such as lucarbinol, dimethylphenyl ethyl carbinol, phenethyl methyl ethyl carbinol, 3-methyl-5-phenylpentanol, thymol, carvacrol, orcinol monomethyl ether, eugenol, isoeugenol, propenyl guaetol, aromatic Group alcohols and terpene alcohol compounds.

  Examples of ethers include nerol oxide, miloxide, 1,8-cineol, rose oxide, limethol, mentfuran, linalool oxide, butyldimethyldihydropyran, acetoxyamyltetrahydropyran, cedolmethyl ether, methoxycyclodecane, 1-methyl -1-methoxycyclodecane, ethoxymethylcyclododecyl ether, tricyclodecenyl methyl ether, rubofix, cedroxide, ambroxan, glycalva, voiris, anisole, dimethylhydroquinone, paracresylmethylether, acetanisole, anethole, dihydro Anethole, Estragol, Diphenyl ether, Methyl eugenol, Methyl isoeugenol, Benzyl isoeugenol, Phenylmethy Isoamyl ether, beta-naphthyl methyl ether, beta-naphthyl ethyl ether, beta-naphthyl isobutyl ether, aliphatic ethers such as hexamethyl hydro cyclopentane benzopyran, aromatic ethers, terpene oxide compounds.

  Aldehydes include hexyl aldehyde, heptyl aldehyde, octyl aldehyde, nonyl aldehyde, decyl aldehyde, undecyl aldehyde, dodecyl aldehyde, tridecyl aldehyde, trimethyl hexyl aldehyde, methyl octyl acetaldehyde, methyl nonyl acetaldehyde, trans-2-hexenal, cis -4-heptenal, 2,6-nonadienal, cis-4-decenal, undecylene aldehyde, trans-2-dodecenal, trimethylundecenal, 2,6,10-trimethyl-5,9-undecadienal, citral, Citronellal, hydroxycitronellal, perilaldehyde, methoxydihydrocitronellal, citronellyloxyacetaldehyde, 2,4-dimethyl-3- Chlohexenyl aldehyde, isocyclocitral, centenal, mylacaldehyde, rilal, Bernaldehyde, dupical, macear, boronal, setneral, benzaldehyde, phenylacetaldehyde, phenylpropional, cinnamic aldehyde, α-amylcinnamic aldehyde, α-hexylcin Namic aldehyde, hydrotropic aldehyde, anisaldehyde, p-methylphenylacetaldehyde, cuminaldehyde, cyclamenaldehyde, 3- (pt-butylphenyl) propanal, p-ethyl-2,2-dimethylhydrocinnamic aldehyde, 2 -Methyl-3- (p-methoxyphenyl) propanal, pt-butyl-α-methylhydrocinnamic aldehyde, salicyl Aldehyde, heliotropin, ocean propanal, vanillin, ethyl vanillin, aliphatic aldehydes such as methyl vanillin, aromatic aldehydes include terpene aldehyde compounds.

  As acetals, octanal glycol acetal, acetaldehyde ethyl cis-3-hexenyl acetal, citral dimethyl acetal, citral diethyl acetal, acetaldehyde ethyl linalyl acetal, hydroxycitronellal dimethyl acetal, phenylacetaldehyde dimethyl acetal, hydrotropic aldehyde dimethyl acetal , Phenylacetaldehyde glyceryl acetal, acetaldehyde phenylethylethyl acetal, acetaldehyde phenylethylpropyl acetal, phenylpropanal propylene glycol acetal, 4,4,6-trimethyl-2-benzyl-1,3-dioxane, 2,4,6-trimethyl -2-phenyl-1,3-dioxane, 4,4 6-trimethyl-2-butyl-1,3-dioxane, tetrahydropyran indeno -m- dioxin, dimethyl tetrahydroindenyl indeno -m- dioxin include acetal compounds such Karanaru.

  As ketones, acetoin, diacetyl, methyl amyl ketone, ethyl amyl ketone, methyl hexyl ketone, methyl nonyl ketone, methyl heptenone, coabon, camphor, carvone, menthone, d-pulegone, pepitone, fension, geranylacetone, cedryl methyl Ketone, Nootkaton, Ionone, Methylionone, Allylionone, Iron, Damascon, Damasenone, Dynascon, Maltol, Ethylmaltol, 2,5-Dimethyl-4-hydroxyfuranone, pt-butylcyclohexanone, amylcyclopentanone, heptylcyclopentanone , Dihydrojasmon, cis-jasmon, Florex, pricatone, muscone, cybeton, cyclopentadecanone, cyclohexadecenone, 4-cyclohexyl 4-methyl-2-pentanone, p-mentel-6-yl-propanone, 2,2,5-trimethyl-5-menthylcyclopentanone, ethoxyvinyltetramethylcyclohexanone, dihydropentamethylindanone, iso-Esuper (product) Name), Trimofix (trade name), acetophenone, p-methylacetophenone, benzylacetophenone, calone, raspberry ketone, anisylacetone, 4- (4-hydroxy-3-methoxyphenyl) -2-butanone, methylnaphthyl ketone, 4 Aliphatic such as phenyl-4-methyl-2-pentanone, benzophenone, 6-acetylhexamethylindane, 4-acetyldimethyl-t-butylindane, 5-acetyltetramethylisopropylindane, 6-acetylhexatetralin Tons, aromatic ketones, terpene ketone compounds.

  Esters include ethyl formate, cis-3-hexenyl formate, linalyl formate, citronellyl formate, geranyl formate, benzyl formate, phenyl ethyl formate, ethyl acetate, butyl acetate, isoamyl acetate, methyl cyclopentylidene acetate, hexyl acetate, acetic acid Cis-3-hexenyl, trans-3-hexenyl acetate, isononyl acetate, citronellyl acetate, lavandulyl acetate, geranyl acetate, linalyl acetate, mircenyl acetate, tervinyl acetate, menthyl acetate, menthanyl acetate, nopyru acetate, boronyl acetate, isobornyl acetate, acetic acid p-t-butylcyclohexyl, o-t-butylcyclohexyl acetate, tricyclodecenyl acetate, 2,4-dimethyl-3-cyclohexene-1-methanyl acetate, benzyl acetate, phenylethyl acetate, styrylyl acetate, vinegar Cinnamyl, anisyl acetate, p-cresyl acetate, heliotropyl acetate, guayl acetate, cedryl acetate, vetiberyl acetate, decahydro-β-naphthyl acetate, acetyl eugenol, acetyl isoeugenol, ethyl propionate, isoamyl propionate, citronellyl propionate, propionic acid Geranyl, linalyl propionate, terpinyl propionate, benzyl prolionate, cinnamyl propionate, allyl cyclohexylpropionate, tricyclodecenyl propionate, ethyl butyrate, ethyl 2-methylbutyrate, butyl butyrate, isoamyl butyrate, hexyl butyrate, butyric acid Linalyl, geranyl butyrate, citronellyl butyrate, benzyl butyrate, cis-3-hexenyl isobutyrate, citronellyl isobutyrate, geranyl isobutyrate, linalyl isobutyrate, isobutyrate Benzyl acid, phenylethyl isobutyrate, phenoxyethyl isobutyrate, tricyclodecenyl isobutyrate, ethyl isovalerate, propyl valerate, citronellyl isovalerate, geranyl isovalerate, benzyl isovalerate, cinnamyl isovalerate, Phenyl ethyl isovalerate, ethyl caproate, allyl caproate, ethyl enanthate, allyl enanthate, ethyl caprate, citronellyl tiglate, methyl octynecarboxylate, allyl 2-pentyloxyglycolate, cis-3-hexenylmethyl carbonate , Ethyl pyruvate, isoamyl pyruvate, ethyl acetoacetate, ethyl levulinate, methyl benzoate, ethyl benzoate, isobutyl benzoate, isoamyl benzoate, benzyl benzoate, geranyl benzoate, linalyl benzoate, feline benzoate Ruethyl, methyl dihydroxydimethylbenzoate, methyl phenylacetate, ethyl phenylacetate, isobutyl phenylacetate, isoamyl phenylacetate, geranyl phenylacetate, benzyl phenylacetate, phenylethyl phenylacetate, p-cresyl phenylacetate, methyl cinnamate, ethyl cinnamate , Benzyl cinnamate, cinnamyl cinnamate, phenylethyl cinnamate, methyl salicylate, ethyl salicylate, isobutyl salicylate, isoamyl salicylate, hexyl salicylate, cis-3-hexenyl salicylate, benzyl salicylate, phenylethyl salicylate, ethyl anislate, anthranil Methyl acid, ethyl anthranilate, methyl methyl anthranilate, methyl jasmonate, methyl dihydrojasmonate, methyl phenyl glycy Ethyl, phenylglycidic acid ethyl Gurikomeru, fractons, Fureisuton, Furuteto, Jibesukon, aliphatic esters such as Karikisoru (trade name), an aromatic ester, carbonate compounds.

  Examples of the carboxylic acids include carboxylic acid compounds such as geranilic acid, citronellic acid, benzoic acid, phenylacetic acid, phenylpropionic acid, cinnamic acid, and 2-methyl-2-pentenonic acid.

  Examples of lactones include γ-octalactone, γ-nonalactone, γ-decalactone, γ-undecalactone, δ-decalactone, coumarin, dihydrocoumarin, jasmolactone, jasmine lactone, sugar lactone, cyclopentadecanolide, cyclohexanone. Sadecanolide, 12-cyclopentadecanolide, cyclohexadecenolide, 12-oxa-16-hexadecanolide, 11-oxa-16-hexadecanolide, 10-oxa-16-hexadecanolide, ethylene brush note, ethylenedodecanedioate And aliphatic lactones and aromatic lactone compounds.

  Examples of nitrogen-containing compounds include acetylpyrrole, indole, skatole, indolene, 2-acetylpyridine, maritima, 6-methylquinoline, 6-isopropylquinoline, 6-isobutylquinoline, 2-acetylpyrazine, 2,3-dimethylpyrazine, 2-Isopropyl-3-methoxypyrazine, 2-isobutyl-3-methoxypyrazine, 2-sec-butyl-3-methoxypyrazine, trimethylpyrazine, geranylnitrile, citronellylnitrile, 5-phenyl-3-methyl-2-pentene Nitrogen-containing compounds such as nitrile, 3,7-dimethyl-2,6-nonadiene nitrile, cinnamon nitrile, cumin nitrile, dodecane nitrile, tridecene-2-nitrile, 5-methyl-3-heptanone oxime and the like can be mentioned.

  Among these, representative examples include acetyl cedrene, IsoEsuper (trade name), ethyl isovalerate, benzyl isovalerate, ethyl vanillin, ethylene brushate, 1-octen-3-ol, galaxolide (trademark) Name), camphor, methyl cinnamate, geraniol, geranyl acetate, benzyl acetate, linalyl acetate, sandalol (trade name), cyclamenaldehyde, cyclopentadecanolide, citral, citronellal, citronellol, methyl dihydrojasmonate, cisjasmine, Damascon, Turpiol, Tonalid (trade name), Vacdanol, Vanillin, Hydroxycitronellal, Phenylacetaldehyde, 2-Phenylethanol, Hexylcinnamic aldehyde, Cis-3-hexenol, Heliotro Emissions, methyl ATRA preparative rates, methyl ionone, menthol, ionone, linalool, lyral (trade name), Kobanoru (trade name), Lilial (brand name), rose oxide can be exemplified.

  Among these, as perfumes, terpene hydrocarbons, terpene alcohols, terpene oxides, terpene aldehydes, terpene ketones, terpene carboxylic acids, terpene lactones, terpene carboxylic esters and the like terpene compounds and / or aliphatic esters It is preferable to use ester compounds such as furan carboxylic acid esters, aliphatic cyclic carboxylic acid esters, cyclohexyl carboxylic acid esters, terpene carboxylic acid esters, and aromatic carboxylic acid esters.

Moreover, it is preferable to use a heat-resistant fragrance | flavor as a fragrance | flavor in this invention. By using heat-resistant fragrances, it is possible to mask the bad odor caused by the decomposition of the resin by releasing fragrance at the time of laser engraving, and to make a laser engraved layer that can be stored for a long time with little odor emission at room temperature it can.
Here, the heat-resistant fragrance is a fragrance that masks the bad odor caused by decomposition of the resin by releasing the fragrance during the laser engraving work and that can be stored for a long time with little fragrance being emitted at room temperature. Say.

Specifically, as the heat-resistant fragrance, one or more fragrance components selected from the group consisting of heliotrop, jasmine, rose, orange flower, amber, and musk are shown below. Preferably used.
Further, as a more specific fragrance, an oriental base mainly composed of the following patchouli oil, a fragrance component obtained from the group consisting of the following rose, amber, musk, and jasmine, a dioctyl phthalate solvent ( There is a fragrance of the tab (TABU) type added with DOP.
Oriental base: patchouli oil, hercoline (methyl abieticate), vanillin, ethyl vanillin, coumarin rose fragrance ingredients: phenylethyl alcohol, geraniol, iso-bornylmethoxycyclohexanol (iso-Bornyl methoxycyclohexanol)
Amber fragrance ingredient: Tetrahydroparamethylquinoline Musk fragrance ingredient: Garac solid, musk ketone Jasmine fragrance ingredient: α-amylcinnamaldehyde, methyl dihydrojasmonate

In addition, the following heliotrope-based fragrance components are used as the main fragrance, and jasmine-based fragrance components, as well as rose-based fragrance components and orange flower-based fragrance components, are added to the solvent DOP in order to impart harmonicity and diffusibility. Amethyst type fragrances added together with are also preferred.
Heliotrope fragrance ingredients: heliotropin, musk ketone, coumarin, ethyl vanillin, acetyl cedrene, hercoline (methyl abieticate), eugenol, methyl ionone Rose fragrance ingredients: Damascon-β, Damascon-α, iso-bornylmethoxycyclohexanol Orange Flower perfume ingredients: methyl anthranilate, γ-undecalactone, γ-nonalactone Jasmine perfume ingredients: methyl dihydrojasmonate

  Furthermore, it is also preferable to use 6-hydroxyalkanoic acid or 6- (5- and / or 6-alkenoyloxy) alkanoic acid 6- (5- and / or 6-alkenoyloxy) alkanoic acid as another heat-resistant fragrance.

  The content of the fragrance is preferably 0.003% by weight to 1.5% by weight, and more preferably 0.005% by weight to 1.0% by weight with respect to the relief forming layer in the present invention. If the fragrance component is below such a range, the masking effect cannot be fully exerted, and if it exceeds the above range, the fragrance of the fragrance becomes too strong and does not lead to improvement of the working environment, and the engraving sensitivity is low. May arise.

Hereinafter, the fragrance | flavor with respect to an acrylic odor is explained in full detail.
Among the polymerizable compounds (A) described above, the acrylic acid ester monomer and the methacrylic acid ester monomer are one of important raw materials constituting the relief forming layer in the present invention and have an odor as an acrylic odor. It is. These monomers give an odor when a slight amount (100 ppb) remains even after the relief forming layer is crosslinked and cured by light or heat.

In particular, for a relief forming layer having such an acrylic odor, it is possible to reduce the acrylic odor by using the following perfumes of group a and group b.
Group a: at least one fragrance selected from a fragrance group having an orange note b group: at least one fragrance selected from a fragrance group having a green note

Fragrance groups having orange note (group a) include, for example, orange oil valencia, bergamot oil, neroli oil, pettigren oil, d-limonene, linalool, orange flower absolute, linalyl acetate, methylanthranilate, uranium thiol, Examples thereof include methyl beta naphthyl ketone and arayara, and orange oil Valencia or bergamot oil is particularly preferable.
These may be used alone or in combination of two or more.
The addition amount of the fragrance selected from this a group is 0.001% by mass to 3.0% by mass with respect to the mass of the relief forming layer from the viewpoint of sufficient masking effect and appropriate fragrance, and further, engraving sensitivity. % Is preferable, 0.003 mass% to 1.5 mass% is more preferable, and 0.005 mass% to 1.0 mass% is most preferable.

Further, the fragrance group (group b) having a green note includes, for example, cis-3-hexenol, cis-3-hexenyl acetate, phenylacetaldehyde, dimethyltetrahydrobenzaldehyde, methylphenylcarbinyl acetate, methyloctyne carbonate, allyl butyrate. Rate, cuminaldehyde, allylcyclohexyloxyacetate, butyl orthobutyl glycolate, pyrazine, ethyl benzoate, etc., and particularly preferred are cis-3-hexenol, cis-3-hexenyl acetate, phenylacetaldehyde, dimethyltetrahydrobenzaldehyde. , Methyl phenylcarbinyl acetate, methyl octyne carbonate. These green notes are fragrance components that are also present in natural fragrances such as rose, geranium, and violet leaf, but their origins are not particularly limited.
These may be used alone or in combination of two or more.
The addition amount of the fragrance selected from this b group is 0.001% by mass to 3.0% by mass with respect to the mass of the relief forming layer from the viewpoint of sufficient masking effect and appropriate fragrance, and further engraving sensitivity. % Is preferable, 0.003 mass% to 1.5 mass% is more preferable, and 0.005 mass% to 1.0 mass% is most preferable.

  Moreover, the preferable mass ratio of the fragrance | flavor of a group and b group is preferable from the point of sufficient masking effect and the balance of fragrance, a group: b group = 150: 1-1: 1, a group: b group = 100 : 1-1: 1 are more preferable.

  In the present invention, the role of the fragrance in the actual relief forming layer is to mask the odor generated during the laser irradiation, that is, to neutralize the acrylic odor, and the fragrance is scented from the non-irradiated portion of the laser. Since there is also a reduction effect, for example, in addition to the fragrance having the orange note of the fragrance of the a group and the green note of the fragrance of the b group, conventionally known fragrance components described above can be used freely.

Hereinafter, the arbitrary components suitably used for the relief forming layer in the present invention will be described.
As the optional component, (D) a photothermal conversion agent capable of absorbing light having a wavelength of 700 nm to 1300 nm, a polymerization initiator, and the like are preferably used.

<(D) Photothermal conversion agent>
The relief forming layer in the present invention preferably contains (D) a photothermal conversion agent. The photothermal conversion agent is considered to promote thermal decomposition of the relief forming layer 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 1300 nm is used as a light source for laser engraving, the relief forming layer in the present invention is a light having a wavelength of 700 nm to 1300 nm. It is preferable to contain a photothermal conversion agent capable of absorbing water.
Various dyes or pigments are used as the photothermal conversion agent in the present invention.

  Among the photothermal conversion agents, as the dye, commercially available dyes and known ones described in documents such as “Dye Handbook” (edited by the Society for Synthetic Organic Chemistry, published in 1970) can be used. Specifically, azo dyes, metal complex azo dyes, pyrazolone azo dyes, naphthoquinone dyes, anthraquinone dyes, phthalocyanine dyes, carbonium dyes, diimmonium compounds, quinoneimine dyes, methine dyes, cyanine dyes, squarylium dyes, pyrylium salts, metal thiolate complexes And the like.

Examples of the dye preferably used in the present invention include the dyes described in paragraphs [0124] to [0137] of JP-A-2008-63554.
One suitable photothermal conversion agent in the present invention is at least one compound selected from cyanine compounds and phthalocyanine compounds from the viewpoint of high engraving sensitivity. Further, when the photothermal conversion agent is used in a combination (condition) in which the thermal decomposition temperature of the hydrophilic polymer suitable as the binder polymer is equal to or higher than the thermal decomposition temperature, the engraving sensitivity tends to be further increased, which is preferable.

Of the photothermal conversion agents used in the present invention, the dye is preferably a dye having an absorption maximum at a wavelength of 700 nm to 1300 nm.
Dyes that can be preferably used in the present invention include cyanine dyes such as heptamethine cyanine dyes, oxonol dyes such as pentamethine oxonol dyes, indolium dyes, benzindolinium dyes, benzothiazolium dyes, quinolinium Among the phthalide compounds and the like reacted with a system dye and a developer, those having a maximum absorption wavelength at 700 nm to 1300 nm can be mentioned. The light absorption characteristics vary greatly depending on the type of substituent and position in the molecule, the number of conjugate bonds, the type of counterion, the surrounding environment in which the dye molecule is present, and the like.

  Further, commercially available laser dyes, supersaturated absorbing dyes, and near infrared absorbing dyes can also be used. For example, as a laser dye, trade marks “ADS740PP”, “ADS745HT”, “ADS760MP”, “ADS740WS”, “ADS765WS”, “ADS745NH”, “ADS790NH”, “ADS800NH” of American Die Source (Canada), Trademarks “NK-3555”, “NK-3509”, and “NK-3519” manufactured by Hayashibara Biochemical Laboratories, Inc. can be mentioned. In addition, as a near-infrared absorbing pigment, trade names “ADS775MI”, “ADS775MP”, “ADS775HI”, “ADS775PI”, “ADS775PP”, “ADS780MT”, “ADS780BP”, “ADS793EI”, trade names “ADS775MI”, “ADS775MP”, “ADS775HI” , “ADS798MI”, “ADS798MP”, “ADS800AT”, “ADS805PI”, “ADS805PP”, “ADS805PA”, “ADS805PF”, “ADS812MI”, “ADS815EI”, “ADS818HI”, “ADS818HT”, “ADS8” ADS830AT, ADS838MT, ADS840MT, ADS845BI, ADS905AM, ADS956BI, ADS1040T, "ADS1040P", "ADS1045P", "ADS1050P", "ADS1060A", "ADS1065A", "ADS1065P", "ADS1100T", "ADS1120F", "ADS1120P", "ADS780WS", "ADS785WS", "ADS790WS", "ADS790WS", "ADS790WS" , “ADS820WS”, “ADS830WS”, “ADS850WS”, “ADS780HO”, “ADS810CO”, “ADS820HO”, “ADS821NH”, “ADS840NH”, “ADS880MC”, “ADS890MC”, “Yamamoto Co., Ltd.” , Trademarks “YKR-2200”, “YKR-2081”, “YKR-2900”, “YKR-2100”, “YKR-3071”, Arimoto Made by Manabu Industry Co., Ltd., trademark "SDO-1000B", Hayashibara Biochemical Laboratories Inc., trademark "NK-3508", mention may be made of the "NKX-114". However, it is not limited only to these.

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

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

The carbon black applicable to the present invention has a specific surface area of at least 150 m ² / g and a DBP number of at least from the viewpoint of improving engraving sensitivity by efficiently transferring heat generated by photothermal conversion to surrounding polymers. Conductive carbon black, which is 150 ml / 100 g, is preferred.

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

Suitable conductive carbon blacks having a specific surface area up to about 1500 m ² / g and a DBP number up to about 550 ml / 100 g are for example Ketjenluck® EC300J, Ketjenluck® EC600J (from Akzo), It is commercially available under the names Princex® XE (from Degussa) or Black Pearls® 2000 (from Cabot), Ketjen Black (manufactured by Lion Corporation).

  The content of the photothermal conversion agent in the relief forming layer varies greatly depending on the molecular extinction coefficient inherent to the molecule, but is preferably in the range of 0.01% by mass to 20% by mass with respect to the total mass of the relief forming layer. Preferably it is 0.05 mass%-10 mass%, Most preferably, it is the range of 0.1 mass%-5 mass%.

<(E) Polymerization initiator>
The relief forming layer in the present invention preferably contains (E) a polymerization initiator.
As the polymerization initiator, those known to those skilled in the art can be used without limitation. Specifically, for example, Bruce M. Monroe et al., Chemical Revue, 93, 435 (1993) and RSD Davidson, Journal of Photochemistry and biology A: Chemistry, 73.81 (1993); JPFaussier, “Photoinitiated Polymerization-Theory and Applications ": Rapra Review vol. 9, Report, Rapra Technology (1998); M. Tsunooka et al., Prog. Polym. Sci., 21, 1 (1996). FDSaeva, Topics in Current Chemistry, 156, 59 (1990); GGMaslak, Topics in Current Chemistry, 168, 1 (1993); HBShuster et al, JACS, 112,6329 (1990); IDFEaton et al, JACS, 102 , 3298 (1980) and the like, a group of compounds that cause oxidative or reductive bond cleavage is also known.

  Hereinafter, a specific example of a preferable polymerization initiator will be described in detail with respect to a radical polymerization initiator which is a compound that generates radicals by light and / or heat energy and initiates and accelerates a polymerization reaction of a polymerizable compound. Are not limited by these statements.

  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 improving sensitivity and relief edge shape, (c) organic peroxides and (l) azo compounds are more preferable, and (c) organic peroxides are particularly preferable.
Usually, engraving sensitivity decreases when the hardness is increased to improve the edge shape of the relief. However, the above-described sulfur-containing polyfunctional monomer mentioned as a preferred embodiment of the polymerizable compound and the preferred polymerization initiator as described above By using, the edge shape can be improved without lowering the engraving sensitivity. This is probably because the oxygen atom and nitrogen atom in the polymerization initiator form an interaction with the sulfur atom of the sulfur-containing polyfunctional monomer, and both components are close to each other, increasing the degree of polymerization and increasing the hardness. The edge shape is improved, and the low temperature thermal decomposition characteristics of the sulfur-containing polyfunctional monomer are expected to suppress a decrease in sensitivity due to an increase in the degree of polymerization.

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

(C) Organic peroxide Preferred as a radical polymerization initiator that can be used in the present invention (c) Organic peroxide includes almost all organic compounds having one or more oxygen-oxygen bonds in the molecule. Examples thereof include methyl ethyl ketone peroxide, cyclohexanone peroxide, 3,3,5-trimethylcyclohexanone peroxide, methylcyclohexanone peroxide, acetylacetone peroxide, 1,1-bis (tertiary butyl peroxy) -3,3. 5-trimethylcyclohexane, 1,1-bis (tertiarybutylperoxy) cyclohexane, 2,2-bis (tertiarybutylperoxy) butane, tertiary butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene Hydroperoxide, parameter hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, ditertiary butyl peroxide, tertiary butyl Cumyl peroxide, dicumyl peroxide, bis (tertiarybutylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-di (tertiarybutylperoxy) hexane, 2,5-xanoyl peroxide, peroxy Succinic oxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, meta-toluoyl peroxide, diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-2-ethoxyethyl peroxy Carbonate, dimethoxyisopropyl peroxycarbonate, di (3-methyl-3-methoxybutyl) peroxydicarbonate, tertiary butyl peroxyacetate, tertiary butyl peroxypivalate, tertiary butyl peroxyneodecanoate, tarsha Tributyl peroxyoctanoate, tertiary butyl peroxy-3,5,5-trimethylhexanoate, tertiary butyl peroxylaurate, tertiary carbonate, 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'-te Tra- (t-octylperoxycarbonyl) benzophenone, 3,3′4,4′-tetra- (cumylperoxycarbonyl) benzophenone, 3,3′4,4′-tetra- (p-isopropylcumylperoxycarbonyl) ) Benzophenone, carbonyldi (t-butylperoxydihydrogen diphthalate), carbonyldi (t-hexylperoxydihydrogen diphthalate) and the like.

  Among them, 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- (cumylper) Peroxyesters such as (oxycarbonyl) benzophenone, 3,3′4,4′-tetra- (p-isopropylcumylperoxycarbonyl) benzophenone, di-t-butyldiperoxyisophthalate are preferred.

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

The polymerization initiator in the present invention may be used alone or in combination of two or more.
The polymerization initiator can be added in a proportion of preferably 0.01% by mass to 10% by mass, more preferably 0.1% by mass to 3% by mass with respect to the total mass of the relief forming layer.

<Other additives>
The relief forming layer in the present invention preferably contains a plasticizer.
The plasticizer has an action of softening the relief forming layer and needs to be compatible with the binder polymer.
As the plasticizer, for example, dioctyl phthalate, didodecyl phthalate or the like, polyethylene glycols, polypropylene glycol (monool type or diol type), polypropylene glycol (monool type or diol type) are preferably used.

In the relief forming layer of the present invention, it is more preferable to add nitrocellulose or a highly heat conductive substance as an additive for improving engraving sensitivity.
Since nitrocellulose is a self-reactive compound, it generates heat during laser engraving and assists in thermal decomposition of a binder polymer such as a hydrophilic polymer. As a result, it is estimated that the engraving sensitivity is improved.
Moreover, a highly heat conductive substance is added in order to assist heat transfer, and examples of the heat conductive substance 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, silver fine particle, or copper fine particle having a particle size of micrometer order to several nanometer order. Particularly preferred is a conjugated polymer, and specific examples include polyaniline and polythiophene. It is done.
Moreover, the sensitivity at the time of photocuring a relief forming layer can be further improved by using a co-sensitizer.

Furthermore, the relief forming layer may contain a small amount of a thermal polymerization inhibitor. This thermal polymerization inhibitor is used to prevent unnecessary thermal polymerization of the polymerizable compound during the production or storage of the relief forming layer.
Furthermore, a coloring agent such as a dye or a pigment may be added for the purpose of coloring the relief forming layer. 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 when the relief forming layer is cured, a known additive such as a filler may be added.

<Configuration of relief printing plate precursor>
The relief printing plate precursor for laser engraving of the present invention has a relief forming layer composed of the aforementioned components. This relief forming layer is preferably provided on a support.
Here, in the present invention, the “relief printing plate precursor for laser engraving” refers to a state in which a relief forming layer having crosslinkability is cured by at least one of light and heat. Thereafter, the relief printing plate precursor is laser engraved to produce a “relief printing plate”.

The relief printing plate precursor of the present invention may have an adhesive layer between the support and the relief forming layer, if necessary, and also has a slip coat layer and a protective film on the relief forming layer. May be.
Hereinafter, components of the relief printing plate precursor of the present invention will be described.

<Relief forming layer>
The relief forming layer is preferably composed of the above-described components and is a layer that is cured by at least one of light and heat, that is, a layer having crosslinkability.
The production mode of the relief printing plate using the relief printing plate precursor of the present invention is preferably a mode in which the relief printing plate is produced by forming a relief layer by crosslinking the relief forming layer and then laser engraving. By crosslinking the relief forming layer, wear of the relief layer during printing can be prevented, and a relief printing plate having a relief layer having a sharp shape after laser engraving can be obtained.

  In addition, a relief forming layer can be formed by using the coating liquid composition for relief forming layers, and shape | molding this to a sheet form or a sleeve form.

<Support>
The support that can be used for the relief printing plate precursor of the present invention will be described.
The material used for the support in the relief printing plate precursor of the present invention is not particularly limited, but those having high dimensional stability are preferably used. For example, metals such as steel, stainless steel and aluminum, polyester (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.

<Adhesive layer>
In the relief printing plate precursor of the present invention, 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.

  The material that can be used for the adhesive layer may be any material that strengthens the adhesive force after the relief forming layer is crosslinked, and preferably has a strong adhesive force before the relief forming layer is crosslinked. Here, the adhesive force means both the adhesive force between the support / adhesive layer and the adhesive layer / relief forming layer.

  When the adhesive layer and the relief forming layer are peeled from the laminate comprising the support / adhesive layer / relief forming layer at a rate of 400 mm / min, the peel force per 1 cm width of the sample is 1 It is preferably 0.0 N / cm or more or non-peeling, and more preferably 3.0 N / cm or more or non-peeling.

  The adhesive force of the adhesive layer / relief forming layer is such that when the adhesive layer is peeled from the adhesive layer / relief forming layer at a rate of 400 mm / min, the peel force per 1 cm width of the sample is 1.0 N / cm or more or cannot be peeled off. It is preferable that it is 3.0 N / cm or more, or more preferably non-peelable.

  Examples of materials (adhesives) that can be used for the adhesive layer include: Those described in the edition of Skeist, “Handbook of Adhesives”, the second edition (1977) can be used.

<Protective film, slip coat layer>
The relief forming layer becomes a portion (relief layer) where the relief is formed after laser engraving, and the surface of the relief layer functions as an ink deposition part. Since the relief forming layer after cross-linking is reinforced by cross-linking, the surface of the relief forming layer hardly causes scratches or dents that affect printing. However, the relief forming layer before cross-linking is often insufficient in strength, and the surface is likely to have scratches and dents. From such a viewpoint, a protective film may be provided on the surface of the relief forming layer for the purpose of preventing scratches or dents on the surface of the relief forming layer.

  If the protective film is too thin, the effect of preventing scratches and dents cannot be obtained. If the protective film is too thick, handling becomes inconvenient and the cost increases. Therefore, the thickness of the protective film is preferably 25 μm to 500 μm, and more preferably 50 μm to 200 μm.

  As the protective film, a known material as a protective film for a printing plate, 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 plain or 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 Of these, partially saponified polyvinyl alcohol having a saponification degree of 60 mol% to 99 mol%, hydroxyalkyl cellulose having 1 to 5 carbon atoms in the alkyl group, and alkyl cellulose are particularly preferably used from the viewpoint of tackiness.

  When the protective film is peeled from the relief forming layer (and slip coat layer) / protective film at a speed of 200 mm / min, the peel force per 1 cm is preferably 5 mN / cm to 200 mN / cm, preferably 10 mN / cm to 150 mN. / Cm is more preferable. If it is 5 mN / cm or more, it can work without peeling off the protective film during the work, and if it is 200 mN / cm or less, the protective film can be peeled without difficulty.

-Preparation of relief printing plate precursor for laser engraving-
Next, a method for producing a relief printing plate precursor for laser engraving will be described.
Formation of the relief forming layer in the relief printing plate precursor for laser engraving is not particularly limited. For example, a relief forming layer coating solution composition is prepared, and a solvent is removed from the relief forming layer coating solution composition. The method of melt-extruding on a support body after removing is mentioned. Alternatively, the relief forming layer coating solution composition may be cast on a support and dried in an oven to remove the solvent from the coating solution composition.
Thereafter, a protective film may be laminated on the relief forming layer as necessary. Lamination can be performed by pressure-bonding the protective film and the relief forming layer with a heated calendar roll or the like, or by bringing the protective film into close contact with the relief forming layer impregnated with a small amount of solvent on the surface.
When using a protective film, you may take the method of laminating | stacking a relief forming layer on a protective film first, and laminating a support body then.
When providing an adhesive layer, it can respond by using the support body which apply | coated the adhesive layer. When providing a slip coat layer, it can respond by using the protective film which apply | coated the slip coat layer.

  The coating composition for the relief forming layer is prepared, for example, by dissolving a binder polymer and optional photothermal conversion agent and plasticizer in an appropriate solvent, and then dissolving the polymerizable compound and the polymerization initiator. Can be manufactured.

  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 easily volatile) are used as the solvent. Etc.) and the total amount of the solvent added is preferably kept as small as possible. The amount of the solvent added can be suppressed by raising the temperature of the system, but if the temperature is too high, the polymerizable compound is likely to undergo a polymerization reaction, so that the coating after the addition of the polymerizable compound and / or polymerization initiator is performed. The preparation temperature of the liquid composition is preferably 30 ° C to 80 ° C.

  Here, in the present invention, in the case of a relief printing plate precursor for laser engraving, as described above, it refers to the state in which the relief forming layer is crosslinked. 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 (step (1) in the method for producing a relief printing plate of the present invention described later).

  The thickness of the relief forming layer in the relief printing plate precursor of the present invention 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, before and after crosslinking. is there.

[Relief printing plate and its manufacture]
The method for producing a relief printing plate of the present invention comprises (1) a step of crosslinking an uncrosslinked relief forming layer in the relief printing plate precursor for laser engraving of the present invention by at least one of irradiation with actinic rays and heating (hereinafter referred to as “ And (2) a step of laser engraving the crosslinked relief forming layer to form a relief layer (hereinafter referred to as “step (2)” as appropriate). Features. By the method for producing a relief printing plate of the present invention, the relief printing plate of the present invention having a relief layer on a support can be produced.

<Step (1)>
The relief printing plate precursor for laser engraving of the present invention has a relief forming layer cured by crosslinking as described above. In order to obtain such a relief forming layer, it is preferable to use a step of crosslinking the uncrosslinked relief forming layer in the relief printing plate precursor for laser engraving of the present invention by irradiation with active light and / or heating.
The term “crosslinking” in the present invention is a concept including a crosslinking reaction for linking binder polymers, and a relief by a polymerization reaction between polymerizable compounds having an ethylenically unsaturated bond or a reaction between a binder polymer and a polymerizable compound. It is a concept that includes the curing reaction of the forming layer.

As described above, in the step (1), crosslinking of the uncrosslinked relief forming layer is performed by irradiation with actinic rays and / or heat.
In the step (1), when the step of crosslinking by light and the step of crosslinking by heat are used in combination, these steps may be simultaneous with each other or separate steps.

Step (1) is a step of crosslinking the relief forming layer of the relief printing plate precursor for laser engraving by at least one of irradiation and heating.
The relief forming layer preferably contains a polymerizable compound, a binder polymer, a photothermal conversion agent, and a polymerization initiator, and in step (1), the polymerizable compound is polymerized by the action of the polymerization initiator to form a crosslink. It is a process to do.
The polymerization initiator is preferably a radical generator, and the radical generator is roughly classified into a photopolymerization initiator and a thermal polymerization initiator depending on whether the trigger for generating radicals is light or heat.

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 (step of crosslinking by light ).
The irradiation with actinic light 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 support side of the relief forming layer is the back side, the surface may only be irradiated with actinic rays, but if the support is a transparent film that transmits actinic rays, it is preferable to irradiate the back side with actinic rays. . 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 crosslinked by heating the relief printing plate precursor for laser engraving. (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.

In the case where the step (1) 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 restrictions on the raw materials of the printing plate precursor. rare.
When step (1) 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 being heated. The raw materials to be used must be carefully selected.
A thermal polymerization initiator can be added during the thermal crosslinking. As the thermal polymerization initiator, it can be used as a commercial thermal polymerization initiator for free radical polymerization. Examples of such a thermal polymerization initiator include a compound containing a suitable peroxide, hydroperoxide, or azo group. Representative vulcanizing agents can also be used for crosslinking. Thermal crosslinking can also be performed by adding a heat-curable resin, such as an epoxy resin, as a crosslinking component to the layer.

As a crosslinking method of the relief forming layer in the step (1), 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 second, the adhesiveness of engraving residue generated during laser engraving is suppressed. When an uncrosslinked relief-forming layer is laser engraved, unintended portions are likely to melt and deform due to residual heat that has propagated around the laser-irradiated portion, and a sharp relief layer may not be obtained. In addition, as a general property of a material, a material having a low molecular weight tends to be liquid rather than solid, that is, the adhesiveness tends to be strong. The engraving residue generated when engraving the relief forming layer tends to become more tacky as more low-molecular materials are used. Since the polymerizable compound which is a low molecule becomes a polymer by crosslinking, the generated engraving residue tends to be less tacky.

<Step (2)>
In the method for producing a relief printing plate of the present invention, the step (1) is followed by (2) a step of forming a relief layer by laser engraving a crosslinked relief forming layer. By the method for producing a relief printing plate of the present invention, the relief printing plate of the present invention having a relief layer on a support can be produced.

In the method for producing a relief printing plate of the present invention, following the step (2), the following steps (3) to (5) may be further included as necessary.
Step (3): A step of rinsing the surface of the engraved relief layer with water or a liquid containing water as a main component (rinsing step).
Step (4): A step of drying the engraved relief layer (drying step).
Step (5): A step of imparting energy to the relief layer after engraving and further crosslinking the relief layer (post-crosslinking step).

Step (2) is a step of forming a relief layer by laser engraving the relief forming layer crosslinked in step (1). 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 scanning and irradiating the relief forming layer is exemplified.
In this step (2), an infrared laser is preferably used. When irradiated with an infrared laser, the molecules in the relief forming layer undergo molecular vibrations and generate heat. 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 part, and molecules in the relief forming layer are selectively removed by molecular cutting or ionization, that is, Sculpture is made. The advantage of laser engraving is that the engraving depth can be set arbitrarily, so that the structure can be controlled three-dimensionally. For example, a portion that prints fine halftone dots can be engraved shallowly or with a shoulder so that the relief does not fall down due to printing pressure. As a result, the ink is less likely to be buried in the groove, and it is possible to suppress the crushing of the extracted characters.
In particular, when engraving with an infrared laser corresponding to the absorption wavelength of the photothermal conversion agent, the relief forming layer can be selectively removed with higher sensitivity, and a relief layer having a sharp image can be obtained. As the infrared laser used in the step (2), a carbon dioxide laser or a semiconductor laser is preferable from the viewpoint of productivity, cost, and the like. In particular, a semiconductor infrared laser with a fiber is preferably used.

When engraving residue is attached to the engraving surface, a step (3) of rinsing the engraving residue by rinsing the engraving surface with water or a liquid containing water as a main component may be added. As a means of rinsing, there is a method of washing with tap water, a method of spraying high-pressure water, and a known batch type or conveying type brush type washing machine as a photosensitive resin relief printing machine. For example, when the engraving residue cannot be removed, a rinsing solution to which a surfactant is added may be used.
When the step (3) of rinsing the engraved surface is performed, it is preferable to add a step (4) of drying the engraved relief forming layer and volatilizing the rinse liquid.
Furthermore, you may add the process (5) which further bridge | crosslinks a relief forming layer as needed. By performing the additional crosslinking step (5), the relief formed by engraving can be further strengthened.

As described above, the relief printing plate of the present invention having a relief layer on a support is obtained.
The thickness of the relief layer of the relief printing plate is preferably 0.05 mm or more and 10 mm or less, more preferably 0.05 mm or more from the viewpoint of satisfying various flexographic printing aptitudes such as abrasion resistance and ink transferability. 7 mm or less, particularly preferably 0.05 mm or more and 0.3 mm or less.

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

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

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

  First, synthesis examples of the sulfur-containing polyfunctional monomer M1, the sulfur-containing polyfunctional monomer M2, and the polyfunctional monomer C used in Examples and Comparative Examples are shown.

[Synthesis Example: Synthesis of sulfur-containing polyfunctional monomer M1]
In a 500 mL three-necked flask equipped with a stirring blade and a condenser tube, 3,3′-thiodipropionic acid (Wako Pure Chemicals, 89.05 g), glycidyl methacrylate (Wako Pure Chemicals, 156.26 g) 1-methoxy-2-propanol (Nippon Emulsifier Co., Ltd., 27.78 g), tetraethylammonium bromide (Tokyo Kasei Co., Ltd., 4.20 g), 4-hydroxy-2,2,6,6-tetramethylpyridine 1 -Oxyl free radical (Tokyo Chemical Industry, 0.5
0 g) was added and stirred at 80 ° C. for 4 hours. To this solution, water (500 g) and ethyl acetate (500 g) were added, transferred to a separatory funnel and stirred vigorously, and then the aqueous layer was removed. Subsequently, a saturated aqueous sodium carbonate solution (200 g) was added and stirred vigorously. The aqueous layer was removed. Subsequently, saturated brine (200 g) was added and stirred vigorously, and then the aqueous layer was removed. After the organic layer was transferred to a 1 L Erlenmeyer flask, magnesium sulfate (100 g) was added and dried. Magnesium sulfate was removed by filtration and ethyl acetate was removed under reduced pressure to obtain sulfur-containing polyfunctional monomer M1 (233.04 g) having the following structure. The structure of the obtained sulfur-containing polyfunctional monomer M1M1 was identified by ¹ H NMR.

[Synthesis Example: Synthesis of sulfur-containing polyfunctional monomer M2]
For the sulfur-containing polyfunctional monomer M2 having the following structure, a synthesis method similar to that for the sulfur-containing polyfunctional monomer M1 is applied, and "3,3'-thiodipropionic acid" Instead of “propionic acid”, synthesis was performed. The structure of the obtained sulfur-containing polyfunctional monomer M2 was identified by ¹ H NMR.

[Synthesis Example: Synthesis of Polyfunctional Monomer C]
The polyfunctional monomer C having the following structure was synthesized by applying the same synthesis method as that of the sulfur-containing polyfunctional monomer M1 and replacing “3,3′-thiodipropionic acid” with “pimelic acid”. The structure of the obtained polyfunctional monomer C was identified by ¹ H NMR.

[Example 1]
1. Preparation of coating composition for relief forming layer 36 g of GOHSENAL T-215 (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., PVA derivative) as a binder polymer in a three-necked flask equipped with stirring blades and cooling tubes, photothermal conversion agent Ketjen Black EC600JD (carbon black, manufactured by Lion Co., Ltd.) 0.75g, 20g of diethylene glycol as plasticizer, 35g of water and 12g of ethanol as solvent, heated at 70 ° C for 120 minutes with stirring to dissolve the polymer It was. Furthermore, 32 g of the sulfur-containing polyfunctional monomer M1 synthesized as described above, 1.8 g of perbutyl Z (manufactured by NOF Corporation) as a polymerization initiator, and the fragrances described in Table 1 below (described in Table 1) Amount: A fragrance amount (mass%) based on the total amount of the coating liquid composition for the relief forming layer was added and stirred for 30 minutes to obtain a flowable coating liquid composition 1 for the relief forming layer.

2. Preparation of relief printing plate precursor for laser engraving A spacer (frame) of a predetermined thickness is placed on a PET substrate, and the coating liquid composition 1 for relief forming layer obtained above is gently so as not to flow out of the spacer (frame). It was cast and dried in an oven at 65 ° C. for 4 hours to provide a relief forming layer having a thickness of about 1 mm.
The obtained relief forming layer was heated at 100 ° C. for 3 hours to thermally cross-link the relief forming layer to obtain a relief printing plate precursor for laser engraving.

3. Preparation of relief printing plate “FD-100” (manufactured by Tosei Electrobeam Co., Ltd.) equipped with a semiconductor laser with a maximum output of 16 W (laser oscillation wavelength 840 nm) as a near-infrared laser engraving machine for the relief forming layer after crosslinking. ), The engraving conditions are set to laser output: 15 W, scanning speed: 100 mm / sec, pitch interval: 0.15 mm, and a relief layer is formed by engraving a solid portion of 2 cm square to form a relief printing plate 1 was obtained.

The thickness of the relief layer of the relief printing plate 1 was 1.45 mm.
Moreover, when the Shore A hardness of the relief layer was measured by the above-mentioned measuring method, it was 63 °. In addition, the measurement of the Shore hardness A of a relief layer was similarly performed also in each Example and comparative example which are mentioned later.

[Examples 2-8, Comparative Examples 1-3]
The “sulfur-containing polyfunctional monomer M1” used in Example 1 was changed to the polyfunctional monomer described in Table 1 below, and the fragrance and the amount added were changed as shown in Table 1 below for laser engraving. Except that the resin composition was prepared, a relief printing plate precursor for laser engraving was prepared in the same manner as in Example 1, and then relief printing plates 2 to 8 and C1 to C3 were prepared from the relief printing plate precursor for laser engraving. did.
Here, in Examples 6-8, only 1 type of fragrance | flavor described in following Table 1 was used.
Further, the thicknesses of the relief layers and Shore A hardness of the obtained relief printing plates 2 to 8 and C1 to C3 are as shown in Table 1 below.

[Examples 9 to 16, Comparative Examples 4 to 6]
The “sulfur-containing polyfunctional monomer M1” used in Example 1 was changed to the polyfunctional monomer described in Table 1 below, and the fragrance and the amount added were changed as shown in Table 1 below for laser engraving. A relief printing plate precursor for laser engraving was prepared in the same manner as in Example 1 except that the resin composition was prepared.
Here, in Examples 14-16, only 1 type of fragrance | flavor described in following Table 1 was used.
The relief printing plate precursor for laser engraving was used in the same manner as in Example 1 except that laser engraving was performed using a carbon dioxide laser engraving machine as follows, and relief printing plates 9 to 16 and C4 to C4 were used. C6 was produced.
That is, “CO ₂ laser marker ML-Z9500” (manufactured by Keyence Corporation) equipped with a carbon dioxide laser with a maximum output of 30 W was used as a carbon dioxide laser engraving machine. Engraving conditions were set such that the laser output was 15 W, the scanning speed was 100 mm / second, and the pitch interval was 0.15 mm, and a solid portion of 2 cm square was engraved to obtain a relief printing plate.
Here, the thicknesses of the relief layers and the Shore A hardness of the obtained relief printing plates 9 to 16 and C4 to C6 are as shown in Table 1 below.

<Evaluation>
-Sculpture depth-
The “engraving depth” of the relief layers of the relief printing plates 1 to 16 and C1 to C6 was measured as follows. Here, “sculpture depth” refers to the difference between the engraved position (height) and the unengraved position (height) when the cross section of the relief layer is observed. The “engraving depth” in this example was measured by observing the cross section of the relief layer with an ultra-deep color 3D shape measuring microscope VK9510 (manufactured by Keyence Corporation). A large engraving depth means high engraving sensitivity. The results are shown in Table 1.

-Odor evaluation-
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):
○: Four or more out of six people recognized the odor reduction effect.
(Triangle | delta): Two or more of six persons recognized the odor reduction effect.
X: The odor reduction effect was not recognized. In addition, when an evaluation score is more than (triangle | delta), it is thought that there is no problem in practical use.
Here, the above-mentioned “odor reduction effect” refers to both a relief printing plate precursor to which a fragrance is added and a relief printing plate precursor having the same composition except that no fragrance is added. It means the effect obtained by laser engraving with the method and comparing the odors at that time.

As shown in Table 1, it was confirmed that the odor during laser engraving was suppressed by the addition of the fragrance. In addition, the engraving depth exceeds 100 μm, and it can be seen that the engraving sensitivity is sufficiently high.
In particular, when a polymerizable compound having a sulfur atom (a sulfur-containing polyfunctional monomer) was used as the polymerizable compound, it was confirmed that the engraving depth was particularly large and a remarkable odor suppressing effect was exhibited.

Claims (13)

  (A) A relief printing plate precursor for laser engraving having a relief forming layer containing at least a polymerizable compound having an ethylenically unsaturated bond, (B) a binder polymer, and (C) a fragrance.   The relief printing plate precursor for laser engraving according to claim 1, wherein the polymerizable compound (A) having an ethylenically unsaturated bond is a compound having a sulfur atom in the molecule.   The relief printing plate precursor for laser engraving according to claim 1, wherein the fragrance (C) includes a natural fragrance.   The relief printing plate precursor for laser engraving according to any one of claims 1 to 3, wherein the fragrance (C) includes a synthetic fragrance.   The relief printing plate precursor for laser engraving according to claim 1, wherein the fragrance (C) contains an ester compound.   The relief printing plate precursor for laser engraving according to claim 1, wherein the fragrance (C) contains a terpene compound.   (D) The relief printing plate precursor for laser engraving according to any one of claims 1 to 6, further comprising a photothermal conversion agent capable of absorbing light having a wavelength of 700 nm to 1300 nm.   The relief printing plate precursor for laser engraving according to any one of claims 1 to 7, wherein the relief forming layer is cured by at least one of light and heat. (1) The step of crosslinking the relief forming layer in the relief printing plate precursor for laser engraving according to any one of claims 1 to 8 by at least one of light and heat, and
(2) forming a relief layer by laser engraving a crosslinked relief forming layer;
A method for producing a relief printing plate comprising   The method for producing a relief printing plate according to claim 9, wherein the step (1) is a step of crosslinking the relief forming layer with heat.   The relief printing plate which has a relief layer manufactured by the manufacturing method of the relief printing plate of Claim 9 or Claim 10.   The relief printing plate according to claim 11, wherein the thickness of the relief layer is from 0.05 mm to 10 mm.   The relief printing plate according to claim 11, wherein the Shore A hardness of the relief layer is from 50 ° to 90 °.