JP6787249B2 - Composition for laser marking and its use - Google Patents

Description

The present invention relates to a composition for laser marking, which comprises a specific salt-forming compound, and its use.

In recent years, the inkjet method has been the mainstream for printing and printing on the surfaces of various containers such as sheets, packaging sheets, egg packs, cards, foods, cosmetics, toiletries, pharmaceuticals, and caps of containers, but ink stains and characters There are many problems in terms of lack of ink or maintenance of equipment. On the other hand, in the movement to automate and unmanned the marking process, a non-contact marking method using laser light, which has a high marking speed, is becoming widespread.

Patent Document 1 and Patent Document 2 propose a non-contact recording method using laser light having a wavelength in the near infrared region. In general, a laser marking ink is composed of a color former, a color developer, and a near-infrared absorbing dye. When a laser beam is applied to the coated object of this ink, the near-infrared absorbing dye absorbs the laser beam and generates heat, so that the coloring agent and the developing agent in the irradiated portion react to develop a color.

In order to obtain good color development ability, it is important to select a near-infrared absorbing dye that is colorless before laser irradiation, strongly absorbs light in the near-infrared region during laser irradiation, and efficiently converts heat. , Phthalocyanine (Patent Document 3), Cyanin (Patent Document 4), and Squalylium (Patent Document 5) have been proposed. However, the phthalocyanine-based material has a structure-derived absorption band in the visible light region and is colored by itself, so that there is a problem in invisibility. In addition, although cyanine-based and squarylium-based materials have good invisibility, they generally have many structures with strong cohesiveness and are difficult to disperse and dissolve, so that there is a problem in viscosity and storage stability as a composition. ..

JP-A-58-209594 JP-A-58-094494 JP-A-2005-119262 JP-A-11-254830 Japanese Unexamined Patent Publication No. 7-25153

The problem to be solved by the present invention is a composition for laser marking, which has extremely high invisibility and near-infrared absorbing ability, excellent viscosity and storage stability, and excellent color development when irradiated with a laser, and a recording method thereof. Is to provide.

That is, the present invention is a salt-forming compound of a squarylium [A] represented by the following general formula (1) and a resin [B] having a cationic group in the side chain, a color former [C], and a color developer [D]. And a composition for laser marking containing the resin [E].
General formula (1)

[In the general formula (1), X _{1 to} X ₁₀ each independently have a hydrogen atom, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, and a substituent. Aryl group which may have a substituent, an aralkyl group which may have a substituent, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, an amino group, a substituted amino group, and -SO ₂ NR. ₁ R ₂ , -COOR ₃ , -CONR ₄ R ₅ , represents a nitro group, a cyano group or a halogen atom, and adjacent groups may form a ring. R _{1 to} R ₅ each independently represent an alkyl group which may have a hydrogen atom or a substituent. n represents an integer of 1 to 4. Z ⁺ represents a hydrogen ion or an inorganic or organic cation. ]

The present invention also relates to the composition for laser marking according to claim 1, wherein the resin [B] having a cationic group in the side chain is a vinyl resin containing a structural unit represented by the following general formula (2). ..
General formula (2)

[In the general formula (2), R ₆ represents an alkyl group which may have a hydrogen atom or a substituent. R _{7 to} R ₉ each independently represent a hydrogen atom, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or an aryl group which may have a substituent, and R Two of _{7 to} R ₉ may be bonded to each other to form a ring. Q is an alkylene group, an arylene group, _{-CONH-R 10} - or _{-COO-R 11} - _{represents, R 10} and _{R 11} represents an alkylene group. Y ⁻ represents an inorganic or organic anion. ]

The present invention also relates to the above-described laser marking composition in which n in the general formula (1) is 1 or 2.

The present invention also relates to the above-mentioned laser marking composition in which the quaternary ammonium salt value of the solid content of the resin [B] having a cationic group in the side chain is 20 to 130 mgKOH / g.

Further, in the present invention, the content of the salt-forming compound of the squarylium [A] and the resin [B] having a cationic group in the side chain is 0.05 to 5% by mass in the total solid content of the composition for laser marking. The present invention relates to the above-mentioned composition for laser marking.

The present invention also relates to a coated product obtained by coating the above-mentioned laser marking composition.

The present invention also relates to a recording material obtained by irradiating the coated object with a laser beam for recording.

Further, the present invention relates to a recording method in which the coated object is irradiated with a laser beam and recorded.

The composition for laser marking of the present invention has excellent invisibility and near-infrared absorption ability, and has viscosity and storage stability by using a specific salt-forming compound having good optical properties and which is hard to aggregate and precipitate. It is excellent in color development when irradiated with a laser.

<Laser marking composition>
The composition for laser marking of the present invention will be described in detail. In the composition for laser marking of the present invention, in addition to a specific salt-forming compound of squarylium [A] and a resin [B] having a cationic group in the side chain, a color former [C] and a color developer [D] , Resin [E] as an essential component, and is composed of other known additives and the like. The salt-forming compound can be used in either the dispersed state or the dissolved state.

<Squaririum [A]>
The squarylium [A] represented by the general formula (1) of the present invention will be described in detail.

General formula (1)

[In the general formula (1), X _{1 to} X ₁₀ each independently have a hydrogen atom, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, and a substituent. Aryl group which may have a substituent, an aralkyl group which may have a substituent, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, an amino group, a substituted amino group, and -SO ₂ NR. ₁ R ₂ , -COOR ₃ , -CONR ₄ R ₅ , represents a nitro group, a cyano group or a halogen atom, and adjacent groups may form a ring. R _{1 to} R ₅ each independently represent an alkyl group which may have a hydrogen atom or a substituent. n represents an integer of 1 to 4. Z ⁺ represents a hydrogen ion or an inorganic or organic cation. ]

In X _{1 to} X ₁₀ , the "alkyl group which may have a substituent" includes a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a tert-butyl group, a tert-amyl group and a 2-ethylhexyl group. Examples thereof include stearyl group, chloromethyl group, trichloromethyl group, trifluoromethyl group, 2-methoxyethyl group, 2-chloroethyl group, 2-nitroethyl group, cyclopentyl group, cyclohexyl group, dimethylcyclohexyl group and the like. Of these, a methyl group, an ethyl group and an n-propyl group are preferable from the viewpoint of synthesis difficulty and invisibility, and a methyl group is particularly preferable.

In X _{1 to} X ₁₀ , the "alkenyl group which may have a substituent" includes a vinyl group, a 1-propenyl group, an allyl group, a 2-butenyl group, a 3-butenyl group, an isopropenyl group, an isobutenyl group and 1 -Pentenyl group, 2-pentenyl group, 3-pentenyl group, 4-pentenyl group, 1-hexenyl group, 2-hexenyl group, 3-hexenyl group, 4-hexenyl group, 5-hexenyl group and the like can be mentioned. Of these, a vinyl group and an allyl group are preferable from the viewpoint of synthesis difficulty and invisibility.

In X _{1 to} X ₁₀ , the "aryl group which may have a substituent" includes a phenyl group, a naphthyl group, a 4-methylphenyl group, a 3,5-dimethylphenyl group, a pentafluorophenyl group, and a 4-bromophenyl group. Groups, 2-methoxyphenyl group, 4-diethylaminophenyl group, 3-nitrophenyl group, 4-cyanophenyl group and the like can be mentioned, and among these, the phenyl group and 4-methylphenyl group are difficult to synthesize and invisible. It is preferable from the viewpoint of sex.

Examples of the "aralkyl group which may have a substituent" in X _{1 to} X ₁₀ include a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group and the like, and among these, the benzyl group is difficult to synthesize. Preferred from the viewpoint of degree and invisibility.

In X _{1 to} X ₁₀ , "alkoxy groups having substituents" include methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, n-octyloxy group and 2-ethylhexyloxy. Examples thereof include a group, a trifluoromethoxy group, a cyclohexyloxy group, a stearyloxy group and the like, and among these, a methoxy group, an ethoxy group and a trifluoromethoxy group are preferable from the viewpoint of synthesis difficulty and invisibility.

In X _{1 to} X ₁₀ , the "aryloxy group which may have a substituent" includes a phenoxy group, a naphthyloxy group, a 4-methylphenyloxy group, a 3,5-chlorophenyloxy group and a 4-chloro-2-. Examples thereof include a methylphenyloxy group, a 4-tert-butylphenyloxy group, a 4-methoxyphenyloxy group, a 4-diethylaminophenyloxy group, a 4-nitrophenyloxy group, and among these, a phenoxy group and a naphthyloxy group. However, it is preferable from the viewpoint of synthesis difficulty and invisibility.

In X _{1 to} X ₁₀ , the "substituted amino group" includes a methyl amino group, an ethyl amino group, an isopropyl amino group, an n-butyl amino group, a cyclohexyl amino group, a stearyl amino group, a dimethyl amino group, a diethyl amino group and a dibutyl amino group. , N, N-di (2-hydroxyethyl) amino group, phenylamino group, naphthylamino group, 4-tert-butylphenylamino group, diphenylamino group, N-phenyl-N-ethylamino group and the like. Of these, a dimethylamino group and a diethylamino group are preferable from the viewpoint of synthetic difficulty and invisibility.

Examples of the "halogen atom" in X _{1 to} X ₁₀ include fluorine, bromine, chlorine and iodine.

In X _{1 to} X ₁₀ , adjacent groups may form a ring, and examples thereof include, but are not limited to, the following structures.

In R _{1 to} R ₅ , the "alkyl group which may have a substituent" has the same meaning as X _{1 to} X ₁₀ .

X _{1 to} X ₁₀ preferably contain an unsubstituted alkyl group from the viewpoint of synthesis difficulty, viscosity, storage stability, invisibility, and near-infrared absorbing ability, and X ₃ , X ₄ , X _7, and X. It is more preferable that at least one of ₈ is an unsubstituted alkyl group, and it is particularly preferable that X ₃ and X ₇ are unsubstituted alkyl groups. The unsubstituted alkyl group is preferably a methyl group.

As the "inorganic or organic cation" of Z ⁺ , known ones can be adopted without limitation, and specific examples thereof include metal atoms, ammonium compounds, pyridinium compounds, imidazolium compounds, phosphonium compounds, and sulfonium compounds. it can. As Z ⁺ , a hydrogen atom, a metal atom, and an ammonium compound are preferable from the viewpoint of synthesis difficulty.

N in the general formula (1) is preferably 1 or 2 from the viewpoint of synthesis difficulty, viscosity, invisibility and near-infrared absorption ability, and among them, n = 2 is particularly from the viewpoint of synthesis difficulty. preferable.

(Manufacturing method of squarylium [A])
The following method can be considered as a method for producing the squalylium [A], but the squalylium [A] used in the present invention is not limited to the following production method. The 1,8-diaminonaphthalene represented by the following formula (3) and the cyclohexanones represented by the following general formula (4) are heated under reflux in a solvent together with a catalyst to be condensed, and then the following formula (5) is obtained. The above 3,4-dihydroxy-3-cyclobutene-1,2-dione is added, and the mixture is further heated under reflux and condensed to obtain a squarylium [A] precursor represented by the general formula (6). Further, by sulfonation of this squalylium [A] precursor in sulfuric acid having an appropriate concentration, squalylium [A] (Z ⁺ = hydrogen ion) represented by the general formula (7) can be obtained. By salt-exchange-reacting the squarylium [A] (Z ⁺ = hydrogen ion) represented by the general formula (7) with an arbitrary ionic compound, Z ⁺ can be converted into an arbitrary inorganic or organic cation. it can.

<Resin [B] having a cationic group in the side chain>
The resin [B] having a cationic group in the side chain of the present invention will be described. The resin [B] having a cationic group in the side chain is not particularly limited as long as it has at least one onium base in the side chain, but a suitable onium salt structure is available from the viewpoint of availability and the like. Is preferably an ammonium salt, an iodonium salt, a sulfonium salt, a diazonium salt, and a phosphonium salt, and more preferably an ammonium salt, an iodonium salt, and a sulfonium salt in consideration of storage stability (thermal stability). .. More preferably, it is an ammonium salt. The resin having a cationic group in the side chain is preferably an acrylic resin, and among them, a vinyl resin containing a structural unit represented by the following general formula (2) is preferably used.

General formula (2)

[In the general formula (2), R ₆ represents an alkyl group which may have a hydrogen atom or a substituent. R _{7 to} R ₉ each independently represent a hydrogen atom, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or an aryl group which may have a substituent, and R Two of _{7 to} R ₉ may be bonded to each other to form a ring. Q is an alkylene group, an arylene group, _{-CONH-R 10} - or _{-COO-R 11} - _{represents, R 10} and _{R 11} represents an alkylene group. Y ⁻ represents an inorganic or organic anion. ]

As the "optionally substituted alkyl group" in R _6, a methyl group, an ethyl group, a propyl group, n- butyl group, i- butyl, t- butyl group, n- hexyl group, a cyclohexyl group Can be mentioned. As the alkyl group, an alkyl group having 1 to 12 carbon atoms is preferable, an alkyl group having 1 to 8 carbon atoms is more preferable, and an alkyl group having 1 to 4 carbon atoms is particularly preferable.

When the alkyl group represented by R ₆ has a substituent, examples of the substituent include a hydroxyl group and an alkoxyl group. Among them, the R _6, a hydrogen atom or a methyl group is most preferable.

In R _{7 to} R ₉ , "alkyl groups that may have substituents" include linear alkyl groups (methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-octyl, n-decyl, etc. n-dodecyl, n-tetradecyl, n-hexadecyl and n-octadecyl, etc.), branched alkyl groups (isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, tert-pentyl, isohexyl, 2-ethylhexyl and 1, 1,3,3-Tetramethylbutyl, etc.), cycloalkyl groups (cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc.) and crosslinked cyclic alkyl groups (norbornyl, adamantyl, pinanyl, etc.). As the alkyl group, an alkyl group having 1 to 18 carbon atoms is preferable, and an alkyl group having 1 to 8 carbon atoms is more preferable.

In R _{7 to} R ₉ , "alkenyl groups that may have a substituent" include linear or branched alkenyl groups (vinyl, allyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3 -Butenyl, 1-methyl-1-propenyl, 1-methyl-2-propenyl, 2-methyl-1-propenyl and 2-methyl-2-propenyl, etc.), cycloalkenyl groups (2-cyclohexenyl and 3- Cyclohexenyl, etc.). As the alkenyl group, an alkenyl group having 2 to 18 carbon atoms is preferable, and an alkenyl group having 2 to 8 carbon atoms is more preferable.

In R _{7 to} R ₉ , the "aryl group which may have a substituent" includes a monocyclic aryl group (phenyl etc.), a condensed polycyclic aryl group (naphthyl, anthracenyl, phenanthrenyl, anthraquinolyl, fluorenyl, naphthoquinolyl and the like). ) And aromatic heterocyclic hydrocarbon groups (thienyl (group derived from thiophene), frill (group derived from furan), pyranyl (group derived from pyran), pyridyl (group derived from pyridine), Examples thereof include 9-oxoxanthenyl (group derived from xanthone) and 9-oxothioxanthenyl (group derived from thioxanthone).

When the alkyl group, alkenyl group and aryl group represented by R _{7 to} R ₉ have a substituent, the substituent includes, for example, a halogen atom, a hydroxyl group, an alkoxyl group, an aryloxy group, an alkenyl group or an acyl group. Examples thereof include a substituent selected from an alkoxycarbonyl group, a carboxyl group, a phenyl group and the like. As the substituent, a halogen atom, a hydroxyl group, an alkoxyl group, and a phenyl group are particularly preferable.

As R _{7 to} R ₉ , an alkyl group which may have a substituent is preferable, and an unsubstituted alkyl group is more preferable. Further, two of R _{7 to} R ₉ may be bonded to each other to form a ring.

In the general formula (2), components of the Q connecting the acrylic sites and ammonium base is an alkylene group, an arylene _{group, -CONH-R 10 -, -} COO-R 11 - _{represents, R 10} and _{R 11} represents an alkylene group represents. Among these, the polymerizable, for reasons of _{availability, -CONH-R 10 -, -} COO-R 11 - is preferably. Further, examples of the "alkylene group" in R ₁₀ and R ₁₁ include a methylene group, an ethylene group, a propylene group and a butylene group, and among these, an ethylene group is particularly preferable.

The component of Y ⁻ in the general formula (2) constituting the counter anion of the resin [B] may be an inorganic or organic anion. As the counter anion, known ones can be adopted without limitation, and specifically, hydroxide ion; halogen ion such as chloride ion, bromide ion and iodide ion; and carboxylate ion such as formate ion and acetate ion; Like carbonate ion, bicarbonate ion, nitrate ion, sulfate ion, sulfite ion, chromate ion, dichromate ion, phosphate ion, cyanide ion, permanganate ion, and even hexacyanoferrate (III) acid ion. Examples include complex ions. From the viewpoint of synthetic suitability and stability, halogen ions and carboxylic acid ions are preferable, and halogen ions are most preferable. When the counter anion is an organic acid ion such as a carboxylic acid ion, the organic acid ion may be covalently bonded to the resin to form an intramolecular salt.

In order to obtain a vinyl-based resin containing a structural unit represented by the general formula (2), which is a preferable mode of the present invention, only a method of copolymerizing an ethylenically unsaturated monomer having an ammonium base as a monomer component is available. Instead, a vinyl-based resin having an amino group copolymerized with an ethylenically unsaturated monomer having an amino group as a monomer component is obtained, and then an onium chloride agent is reacted to obtain ammonium chloride. good.

Hereinafter, specific examples of ethylenically unsaturated monomers that can be used to obtain a vinyl-based resin containing a structural unit represented by the general formula (2), which is a preferable mode of the present invention, will be shown. In the present specification, when either or both of "acrylic, methacrylic" is indicated, it may be described as "(meth) acrylic". Similarly, when either or both of "acryloyl and methacryloyl" are indicated, it may be described as "(meth) acryloyl".

Examples of the ethylenically unsaturated monomer having a quaternary ammonium base include (meth) acryloyloxyethyltrimethylammonium chloride, (meth) acryloyloxyethyltriethylammonium chloride, (meth) acryloyloxyethyldimethylbenzylammonium chloride, and (meth). ) Alkyl (meth) acrylate-based quaternary ammonium salts such as acryloyloxyethyl methylmorpholinoammonium chloride, (meth) acryloylaminopropyltrimethylammonium chloride, (meth) acryloylaminoethyltriethylammonium chloride, (meth) acryloylaminoethyldimethylbenzyl Examples thereof include alkyl (meth) acryloylamide-based quaternary ammonium salts such as ammonium chloride, dimethyldiallylammonium methylsulfate, and trimethylvinylphenylammonium chloride. Of these, alkyl (meth) acrylate-based quaternary ammonium salts are preferable.

Examples of the ethylenically unsaturated monomer having an amino group include dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dipropylaminoethyl (meth) acrylate, diisopropylaminoethyl (meth) acrylate, and dibutylamino. Ethyl (meth) acrylate, diisobutylaminoethyl (meth) acrylate, dit-butylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylamide, diethylaminopropyl (meth) acrylamide, dipropylaminopropyl (meth) acrylamide, diisopropyl (Meta) acrylic acid ester having a dialkylamino group such as aminopropyl (meth) acrylamide, dibutylaminopropyl (meth) acrylamide, diisobutylaminopropyl (meth) acrylamide, dit-butylaminopropyl (meth) acrylamide, or (meth) Examples thereof include styrenes having a dialkylamino group such as dimethylaminostyrene and dimethylaminomethylstyrene, diallylamine compounds such as diallylmethylamine and diallylamine, and amino such as N-vinylpyrrolidin, N-vinylpyrrolidone and N-vinylcarbazole. Group-containing aromatic vinyl-based monomers can be mentioned.

Examples of the onium chloride agent include alkyl sulfuric acid such as dimethyl sulfuric acid, diethyl sulfuric acid, or dipropyl sulfuric acid, sulfonic acid ester such as methyl p-toluenesulfonate, or methyl benzenesulfonate, methyl chloride, ethyl chloride, propyl chloride, or Examples thereof include alkyl chlorides such as octyl chloride, methyl bromide, ethyl bromide, propyl bromide, alkyl bromides such as octyl chloride, benzyl chloride, benzyl bromide and the like.

In the reaction between an ethylenically unsaturated monomer having an amino group and an onium chloride agent, an onium chloride agent having an equimolar amount or less with respect to the amino group is usually added dropwise to an ethylenically unsaturated monomer solution having an amino group. It can be done by doing. The temperature during the ammonium chloride reaction is about 90 ° C. or lower, particularly preferably about 30 ° C. or lower when the vinyl monomer is ammonium chloride, and the reaction time is about 1 to 4 hours.

Alternatively, an alkoxycarbonylalkyl halide can be used as the onium chloride agent. The alkoxycarbonylalkyl halide is represented by the following general formula (8).
DR _12- COOR ₁₃ General formula (8)
(In the general formula (8), D is a halogen such as chlorine or bromine, preferably bromine, and R ₁₂ is an alkylene group having 1 to 6, preferably 1 to 5, and more preferably 1 to 3 carbon atoms. Yes, R ₁₃ is a lower alkyl group having 1 to 6 carbon atoms, preferably 1 to 3 carbon atoms.)

In the reaction of the ethylenically unsaturated monomer having an amino group with the alkoxycarbonylalkyl halide, an equimolar or less alkoxycarbonylalkyl halide is reacted with the amino group in the same manner as the above onium chloride agent, and then -COOR ₁₃ is added. It is obtained by hydrolyzing and converting to a carboxylate ion (-COO-). As a result, an ethylenically unsaturated monomer having a carboxybetaine structure represented by the general formula (8) and having an ammonium base can be obtained.

Other ethylenically unsaturated monomers that can be used other than the structural unit represented by the general formula (2) include, for example, (meth) acrylic acid esters, crotonic acid esters, vinyl esters, and maleic acid. Diesters, fumaric acid diesters, itaconic acid diesters, (meth) acrylamides, vinyl ethers, vinyl alcohol esters, styrenes, (meth) acrylonitrile and the like are preferred.

Specific examples of such a vinyl monomer include the following compounds.
Examples of (meth) acrylic acid esters include methyl (meth) acrylic acid, ethyl (meth) acrylic acid, n-propyl (meth) acrylic acid, isopropyl (meth) acrylic acid, and n-butyl (meth) acrylic acid. , (Meta) acrylate isobutyl, (meth) acrylate t-butyl, (meth) acrylate n-hexyl, (meth) acrylate cyclohexyl, (meth) acrylate t-butylcyclohexyl, (meth) acrylate 2- Ethylhexyl, t-octyl (meth) acrylate, dodecyl (meth) acrylate, octadecyl (meth) acrylate, acetoxyethyl (meth) acrylate, phenyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2- (2-methoxyethoxy) ethyl (meth) acrylate, 3-phenoxy-2-hydroxypropyl (meth) acrylate, ( Benzyl (meth) acrylate, diethylene glycol monomethyl ether (meth) acrylate, diethylene glycol monoethyl ether (meth) acrylate, triethylene glycol monomethyl ether (meth) acrylate, triethylene glycol monoethyl ether (meth) acrylate, (meth) ) Polyethylene glycol monomethyl ether acrylate, (meth) Polyethylene glycol monoethyl ether acrylate, β-phenoxyethoxyethyl (meth) acrylate, nonylphenoxypolyethylene glycol (meth) acrylate, dicyclopentenyl (meth) acrylate, ( Dicyclopentenyloxyethyl acrylate, (meth) trifluoroethyl acrylate, octafluoropentyl (meth) acrylate, perfluorooctylethyl (meth) acrylate, dicyclopentanyl (meth) acrylate, (meth) ) Tribromophenyl acrylate, tribromophenyloxyethyl (meth) acrylate and the like.

Examples of crotonic acid esters include butyl crotonic acid, hexyl crotonic acid and the like.

Examples of vinyl esters include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl methoxyacetate, vinyl benzoate and the like. Examples of maleic acid diesters include dimethyl maleate, diethyl maleate, and dibutyl maleate.

Examples of fumaric acid diesters include dimethyl fumarate, diethyl fumarate, dibutyl fumarate and the like.

Examples of itaconic acid diesters include dimethyl itaconic acid, diethyl itaconic acid, dibutyl itaconic acid and the like.

Examples of (meth) acrylamides include (meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide, and Nn. -Butylacryl (meth) amide, N-t-butyl (meth) acrylamide, N-cyclohexyl (meth) acrylamide, N- (2-methoxyethyl) (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N , N-diethyl (meth) acrylamide, N-phenyl (meth) acrylamide, N-benzyl (meth) acrylamide, (meth) acryloylmorpholin, diacetone acrylamide and the like.

Examples of vinyl ethers include methyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, methoxyethyl vinyl ether and the like. Examples of styrenes include styrene, methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, isopropylstyrene, butylstyrene, hydroxystyrene, methoxystyrene, butoxystyrene, acetoxystyrene, chlorostyrene, dichlorostyrene, bromostyrene, chloromethyl. Examples thereof include styrene, hydroxystyrene protected by a group that can be deprotected by an acidic substance (for example, t-Boc), methyl vinylbenzoate, and α-methylstyrene.

In addition, the ethylenically unsaturated monomer that can be used in a structural unit other than the structural unit represented by the general formula (2) may further contain a copolymerization unit derived from a monomer having an acid group.

Examples of the monomer having an acid group include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, α-chloroacrylic acid and citraconic acid; maleic acid, maleic anhydride, fumaric acid, itaconic acid and anhydrous. Unsaturated dicarboxylic acids such as itaconic acid, citraconic acid, citraconic anhydride, and mesaconic acid or their anhydrides; trivalent or higher unsaturated polycarboxylic acids or their anhydrides; mono (2-acryloyloxyethyl) oxalate ), Mono oxalic acid (2-methacryloyloxyethyl), mono phthalate (2-acryloyloxyethyl), mono (2-methacryloyloxyethyl) and other monovalent or higher polyvalent carboxylic acids [ (Meta) acryloyloxyalkyl] esters; mono (meth) acrylates of both terminal carboxypolymers such as ω-carboxy-polycaprolactone monoacrylate and ω-carboxy-polycaprolactone monomethacrylate can be mentioned.

Examples of a method for obtaining a vinyl-based resin containing a structural unit represented by the general formula (2) suitable for the present invention include anionic polymerization, living anionic polymerization, cationic polymerization, living cationic polymerization, free radical polymerization, and living radical polymerization. , Known methods can be used. Of these, free radical polymerization or living radical polymerization is preferable.

In the case of the free radical polymerization method, it is preferable to use a polymerization initiator. As the polymerization initiator, for example, an azo compound and an organic peroxide can be used. Examples of azo compounds include 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane1-carbonitrile), and 2 , 2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl 2,2'-azobis (2-methylpropionate) , 4,4'-azobis (4-cyanovaleric acid), 2,2'-azobis (2-hydroxymethylpropionitrile), or 2,2'-azobis [2- (2-imidazolin-2-yl) ) Propane] and the like. Examples of organic peroxides are benzoyl peroxide, t-butylperbenzoate, cumenehydroperoxide, diisopropylperoxydicarbonate, di-n-propylperoxydicarbonate, di (2-ethoxyethyl) peroxy. Examples thereof include dicarbonate, t-butylperoxyneodecanoate, t-butylperoxyvivarate, (3,5,5-trimethylhexanoyl) peroxide, dipropionyl peroxide, diacetyl peroxide and the like. These polymerization initiators can be used alone or in combination of two or more. The reaction temperature is preferably 40 to 150 ° C., more preferably 50 to 110 ° C., and the reaction time is preferably 3 to 30 hours, more preferably 5 to 20 hours.

In the living radical polymerization method, side reactions that occur in general radical polymerization are suppressed, and further, the growth of polymerization occurs uniformly, so that a block polymer or a resin having a uniform molecular weight can be easily synthesized.

Among them, the atom transfer radical polymerization method using an organic halide or a sulfonyl halide compound as an initiator and a transition metal complex as a catalyst can be applied to a wide range of monomers and has a polymerization temperature applicable to existing equipment. It is preferable in that it can be adopted. The atom transfer radical polymerization method can be carried out by the method described in References 5 to 12 below.
(Reference 5) Fukuda et al., Prog. Polym. Sci. 2004, 29, 329
(Reference 6) Mattyjaszewski et al., Chem. Rev. 2001,101,2921
(Reference 7) Mattyjaszewski et al., J. Mol. Am. Chem. Soc. 1995, 117, 5614
(Reference 8) Macromolecules 1995, 28, 7901, Science, 1996, 272,866
(Reference 9) International Publication No. 96/030421 (Reference 10) International Publication No. 97/018247 (Reference 11) Japanese Patent Application Laid-Open No. 9-208616 (Reference 12) Japanese Patent Application Laid-Open No. 8-4-1117

It is preferable to use an organic solvent for the above polymerization. The organic solvent is not particularly limited, but for example, ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, xylene, acetone, hexane, methyl ethyl ketone, cyclohexanone, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether. Acetic acid, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate and the like are used. Two or more kinds of these polymerization solvents may be mixed and used.

The amount of ammonium base present in the vinyl-based resin containing the structural unit represented by the general formula (2) suitable for the present invention is not particularly limited, but from the viewpoint of storage stability, ammonium in the resin The salt value is preferably 10 to 200 mgKOH / g, more preferably 20 to 130 mgKOH / g, and even more preferably 20 to 80 mgKOH / g.

In order for the ammonium salt value of the resin to satisfy the above range, the preferable content of the structural unit having a quaternary ammonium base is 4 to 74% by mass in a total of 100% by mass of the structural units constituting the resin. A more preferable range is 8 to 48% by mass.

The molecular weight of the vinyl-based resin containing the structural unit represented by the general formula (2) used in the present invention is not particularly limited, but the converted weight average molecular weight measured by gel permeation chromatography (GPC). Is preferably 1,000 to 500,000, more preferably 3,000 to 15,000.

In the resin [B] having a cationic group in the side chain, the total content of the structural units represented by the above general formula (2) is not particularly limited, but the resin [B] having a cationic group in the side chain. When the total structural units contained in the above are 100% by mass, the total content of the structural units represented by the above general formula (2) is 5% by mass from the viewpoint of the solvent solubility and coloring power of the salt-forming compound. % Or more, more preferably 10 to 50% by mass.

<Salt-forming compound>
The salt-forming compound of the present invention stirs or vibrates an aqueous solution in which a squarylium [A] and a resin [B] having a cationic group in the side chain are dissolved, or an aqueous solution of squarylium [A] and a cation in the side chain. It can be easily obtained by mixing an aqueous solution of the resin [B] having a sex group with stirring or vibration. In the aqueous solution, the anionic group of squarylium [A] and the cationic group of resin [B] are ionized, and these are ionically bonded, and the ion-bonded portion becomes water-insoluble and precipitates. On the contrary, since the salt composed of the counter cation of squarylium [A] and the counter anion of the resin [B] is water-soluble, it can be removed by washing with water or the like. As the squarylium [A] to be used and the resin [B] having a cationic group in the side chain, only one type may be used, or a plurality of types having different structures may be used.

As the aqueous solution used at the time of salt formation, a mixed solution of water and a water-soluble organic solvent may be used in order to dissolve the squarylium [A] and the resin [B] having a cationic group in the side chain. Examples of the water-soluble organic solvent include methanol, ethanol, n-propanol, isopropanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, n-butanol, isobutanol, 2- (methoxymethoxy) ethanol, 2-. Butoxyethanol, 2- (isopentyloxy) ethanol, 2- (hexyloxy) ethanol, ethylene glycol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene Glycol, propylene glycol monomethyl ether acetate, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, triethylene glycol, triethylene glycol monomethyl ether, polyethylene glycol, glycerin, tetraethylene glycol, dipropylene glycol, acetone , Diacetone alcohol, aniline, pyridine, ethyl acetate, isopropyl acetate, methyl ethyl ketone, N, N-dimethylformamide, dimethylsulfoxide, tetrahydrofuran (THF), dioxane, 2-pyrrolidone, 2-methylpyrrolidone, N-methyl-2-pyrrolidone , 1,2-hexanediol, 2,4,6-hexanetriol, tetraflufuryl alcohol, 4-methoxy-4 methylpentanone and the like. These water-soluble organic solvents are preferably used in an amount of 5 to 50% by mass, most preferably 5 to 20% by mass, based on the total weight of the aqueous solution (100% by mass).

The ratio of the squarylium [A] to the resin [B] having a cationic group in the side chain is such that the molar ratio of the total cationic unit of the resin [B] to the total anionic group of the squarylium [A] is 10/1 to 1 to 1. The salt-forming compound of the present invention can be suitably adjusted in the range of 1/10, preferably in the range of 4/1 to 1/4, and particularly preferably in the range of 2/1 to 1/2.

When n in the squarylium [A] represented by the general formula (1) is 2 or more, all the sulfo groups may be salt-formed with the resin [B], or one or more sulfo groups may be the resin [B]. The counter cation of the remaining sulfo group may remain in the Z ⁺ state. The ratio of the resin [B] to Z ⁺ can be controlled by changing the molar ratio at the time of production.

<Color former [C]>
Examples of the color former [C] include electron-donating leuco dyes, and various known compounds can be used. These can be used alone or in combination of two or more, and are appropriately selected depending on the application and required quality characteristics. Specific examples include, but are not limited to, the following compounds.

(1) Triarylmethane compound 3,3'-bis (4-dimethylaminophenyl) -6-dimethylaminophthalide <trade name: crystal violet lactone, CVL>, 3- (4-dimethylamino-2-methylphenyl) ) -3- (4-Dimethylaminophenyl) phthalide, 3,3'-bis (2- (4-dimethylaminophenyl) -2- (4-methoxyphenyl) ethenyl) -4,5,6,7-tetra Chlorophthalide <NIR-Black>, 3,3'-bis (4-dimethylaminophenyl) phthalide <MGL>, 3- (4-dimethylaminophenyl) -3- (1,2-dimethylindole-3-yl) ) Phenylide, 3- (4-dimethylaminophenyl) -3- (2-phenylindole-3-yl) phthalide, 3,3'-bis (4-ethylcarbazole-3-yl) -3-dimethylaminophthalide , 3,3'-bis (1-ethyl-methylindol-3-yl) phthalide <Indrill Red>, 3,3'-bis (2-phenylindole-3-yl) -5-dimethylaminophthalide , Tris (4-dimethylaminophenyl) methane <LCV>, etc.

(2) Diphenylmethane compound 4,4-bis (dimethylamino) benzhydrinbenzyl ether, N-halophenyl-leucooramine, N-2,4,5-trichlorophenylleucooramine and the like.

(3) Xanthene compounds Rhodamine B-anilinolactam, 3-diethylamino-7-dibenzylaminofluorane, 3-diethylamino-7-butylaminofluorane, 3-diethylamino-7-anilinofluorane <Green-2 >, 3-Diethylamino-7- (2-chloroanilino) fluorane, 3-dibutylamino-7- (2-chloroanilino) fluorane <TH-107>, 3-diethylamino-7- (3-trifluoromethylanilino) fluorane <Black-100>, 3-diethylamino-6-methyl-7-anilinofluorane <ODB>, 3-dibutylamino-6-methyl-7-anilinofluorane <ODB-2>, 3-piperidino-6 -Methyl-7-anilinofluorane, 3- (N-isoamyl-N-ethylamino) -6-methyl-7-anilinofluorane <S-205>, 3- (N-ethyl-N-tolylamino) -6-Methyl-7-anilinofluorane, 3- (N-cyclohexyl-N-methylamino) -6-methyl-7-anilinofluorane <PSD-150>, 3-diethylamino-6-chloro-7 -(Β-ethoxyethylamino) fluorane, 3-diethylamino-6-chloro-7- (γ-chloropropylamino) fluorane, 3-cyclohexylamino-6-chlorofluorane <OR-55>, 3-diethylamino-6 -Chloro-7-anilinofluorane, 3- (N-cyclohexyl-N-methylamino) -6-methyl-7-anilinofluorane, 3-diethylamino-7-phenylfluorane, etc.

(4) Thiazine compounds Benzoyl leucomethylene blue, p-nitrobenzoyl leucomethylene blue and the like.

(5) Spiro-based compounds Examples thereof include 3-methylspirodinaphthopyran, 3-ethylspirodinaphthopyran, 3-benzylspirodinaphthopyran, 3-methylnaphtho- (6'-methoxybenzo) spiropyran and the like.

(6) Pentadiene compound 1,1,5,5-tetrakis (4-dimethylaminophenyl) -3-methoxy-1,4-pentadiene, 1,1,5,5-tetrakis (4-dimethylaminophenyl) -1 , 4-Pentadiene, etc.

<Color developer [D]>
Examples of the color developer [D] include electron-accepting compounds, and various known compounds can be used. These can be used alone or in combination of two or more, and are appropriately selected according to the intended use and required quality. Specific examples include, but are not limited to, the following compounds.

Inorganic acidic substances such as active white clay, atapargite, colloidal silica, aluminum silicate, benzyl 4-hydroxybenzoate, ethyl 4-hydroxybenzoate, normal propyl 4-hydroxybenzoate, isopropyl 4-hydroxybenzoate, 4-hydroxybenzoic acid 4-Hydroxybenzoic acid esters such as butyl, 4-hydroxyphthalic acid diesters such as dimethyl 4-hydroxyphthalate, diisopropyl 4-hydroxyphthalate, dibenzyl 4-hydroxyphthalate, dihexyl 4-hydroxyphthalate, and phthalic acid Phydroxy monoesters such as monobenzyl ester, phthalic acid monocyclohexyl ester, phthalic acid monophenyl ester, phthalic acid monomethylphenyl ester, bis (4-hydroxy-3-tert-butyl-6-methylphenyl) sulfide, bis ( Bishydroxyphenyl sulfides such as 4-hydroxy-2,5-dimethylphenyl) sulfide, bis (4-hydroxy-5-ethyl-2-methylphenyl) sulfide, 3,4-bisphenol A, 1,1-bis ( 4-Hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) propane <bisphenol A>, bis (4-hydroxyphenyl) methane <bisphenol F>, 2,2-bis (4-hydroxyphenyl) hexane, Tetramethylbisphenol A, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 1,4-bis (2- (4-hydroxyphenyl) propyl) benzene.

1,3-bis (2- (4-hydroxyphenyl) propyl) benzene, 1,4-bis (4-hydroxyphenyl) cyclohexane, 2,2'-bis- (4-hydroxy-3-isopropylphenyl) propane, Bisphenols such as 1,4-bis (1- (4- (2- (4-hydroxyphenyl) -2-propyl) phenyl) ethyl) benzene, 4-hydroxy-4'-isopropoxydiphenyl sulfone <D-8 >, 4-Hydroxyphenylaryl sulfones such as 4-hydroxy-4'-methoxydiphenyl sulfone, 4-hydroxy-4'-normal propoxydiphenyl sulfone, bis (4-hydroxyphenyl) sulfone <bisphenol S>, tetramethylbisphenol S, bis (3-ethyl-4-hydroxyphenyl) sulfone, bis (3-propyl-4-hydroxyphenyl) sulfone, bis (3-isopropyl-4-hydroxyphenyl) sulfone, bis (3-tert-butyl-4) Bis such as −hydroxy-6-methylphenyl) sulfone, bis (3-chloro-4-hydroxyphenyl) sulfone, bis (3-bromo-4-hydroxyphenyl) sulfone, 2-hydroxyphenyl-4'-hydroxyphenyl sulfone 4-Hydroxyphenylaryl sulfonates such as hydroxyphenyl sulfone, 4-hydroxybenzene sulfonate, 4-hydroxyphenyl-p-tolyl sulfonate, 4-hydroxyphenyl-p-chlorobenzene sulfonate, 4-hydroxybenzoyloxy benzoate 4-Hydroxybenzoyloxy benzoic acid esters such as benzyl acid, ethyl 4-hydroxybenzoyloxy benzoate, normal propyl 4-hydroxybenzoyloxy benzoate, isopropyl 4-hydroxybenzoyloxy benzoate, butyl 4-hydroxybenzoyloxy benzoate , 2,4-Dihydroxybenzophenone, α, α'-bis- (3-methyl-4-hydroxyphenyl) -m-diisopropylbenzophenone, 2,3,4,4'-tetrahydroxybenzophenone and other benzophenones, N- Stearyl-p-aminophenol, 4-hydroxysalitylanilide, 4,4'-dihydroxydiphenyl ether, n-butylbis (hydroxyphenyl) acetate, α, α', α "-tris (4-hydroxyphenyl) -1,3 5-Triisopropylbenzene, died Stearyl gallate.

4,4'-thiobis (6-t-butyl-m-cresol), 2,2-bis (3-allyl-4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxy- 3-Methylphenyl) Sulfide, p-tert-butylphenol, p-phenylphenol, p-benzylphenol, 1-naphthol, 2-naphthol and other phenolic compounds, N, N'-di-m-chlorophenylthiourea and the like Urea compounds, benzoic acid, p-tert-butyl benzoic acid, trichloro benzoic acid, 3-sec-butyl-4-hydroxy benzoic acid, 3-cyclohexyl-4-hydroxy benzoic acid, 3,5-dimethyl-4-hydroxy benzoic acid Acids, terephthalic acid, salicylic acid, 3-isopropylsalicylic acid, 3-tert-butylsalicylic acid, 4- (2- (p-methoxyphenoxy) ethyloxy) salicylic acid, 4- (3- (p-tolylsulfonyl) propyloxy) salicylic acid, Aromatic carboxylic acids such as 5- (p- (2- (p-methoxyphenoxy) ethoxy) cumyl) salicylic acid, and zinc, magnesium, aluminum, calcium, titanium, manganese, tin, nickel and the like of these aromatic carboxylic acids. Salts with polyvalent metals, as well as organic acidic substances such as antipyrine complexes of zinc thiocyanate and complex zinc salts of terephthalaldehyde acid and other aromatic carboxylic acids.

<Resin [E]>
As the resin [E], as a water-soluble resin, cellulose, methyl cellulose, methoxy cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, polyvinyl alcohol, polyacrylamide, polyacrylic acid, casein, gelatin, styrene / maleic anhydride copolymer salt, isobutylene. / Maleic anhydride copolymer salt, polyacrylic acid ester, polyurethane resin, acrylic / styrene resin and the like. As the solvent type resin, styrene / maleic acid, acrylic / styrene resin, polystyrene, polyester, polycarbonate, epoxy resin, polyurethane resin, polybutyral resin, polyacrylic acid ester, styrene / butadiene copolymer, styrene / butadiene / Examples thereof include acrylic acid copolymer, polyvinyl acetate, fluororesin, phenol resin, acrylic silicon / modified silicon resin, aminoalkyd resin, phthalic acid resin, and water-soluble resin is preferable. When used as a composition, a curing agent can be used in combination for the purpose of improving the film strength, heat resistance, water resistance, solvent resistance, etc. of the surface protective layer.

The content of the resin [E] is preferably 5 to 50% by mass, more preferably 5 to 30% by mass, based on the total solid content of the laser marking composition. As the resin [E], at least one selected from the group consisting of polyvinyl alcohol, polyacrylamide, polyacrylic acid, polyacrylic acid ester, polyurethane resin and acrylic / styrene resin is more preferable.

<Other known additives>
Other known additives include sensitizers, storage stabilizers, fillers, dispersants, surfactants, defoamers, optical brighteners, water resistant agents, lubricants, UV absorbers, antioxidants, etc. And can be used according to the required quality.

<Manufacturing method of laser marking composition>
The composition for laser marking of the present invention can be produced by a conventionally known method. The method for preparing various coating liquids for the laser marking composition is not particularly limited, and generally, water is used as a dispersion medium, and the salt-forming compound, the color former [C], the color developer [D], and the resin [ E] and, if necessary, other known additives can be mixed and stirred. The salt-forming compound, the color former [C] and the color developer [D] of the present invention are separately pulverized and dispersed in an aqueous system using a sand grinder, an attritor, a ball mill or the like, and then mixed to obtain an aqueous coating solution. A method and a method of obtaining an aqueous coating liquid after microencapsulating any one of the salt-forming compound, the color former [C] and the color developer [D] of the present invention are known.

The ratio of the color-developing agent [C] and the color-developing agent [D] to be used is appropriately selected according to the type of the color-developing agent [C] and the color-developing agent [D] to be used, and is not particularly limited. ] A color developer [D] of about 0.1 to 50 parts by mass, preferably about 0.1 to 10 parts by mass is used with respect to 1 part by mass.

The salt-forming compound of the present invention is used in the range of 0.1 parts by mass or less, preferably 0.001 to 0.08 parts by mass, with respect to 1 part by mass of the color former [C]. The composition for laser marking is preferably used in the range of 0.05 to 5% by mass, more preferably 0.05 to 3% by mass, based on the total solid content.

It is more preferable that the salt-forming compound, the color former [C], and the color developer [D] of the present invention are atomized so as not to exceed the average particle size of 3 μm. As described above, the salt-forming compound of the present invention can be used even in a dissolved state, so that it is not necessary to pay attention to the average particle size of the salt-forming compound of the present invention. The reason for the atomization is that the more the material is atomized, the more the dot diameter of the colored printing part is almost the same as the spot diameter of the laser beam that is the light source, and the uniform dot diameter is obtained, resulting in high-quality and clear printing. This is because it is thought that a line drawing can be obtained.

<Coated material>
The composition for laser marking of the present invention can be coated on a known base material to obtain a coated product. The known base material may be made of a plastic film, paper, metal foil, glass, ceramic, wood, or the like, and the shape and size of the base material may be arbitrary. The type of synthetic resin constituting the plastic film is not particularly limited, and may be a thermoplastic resin, a thermosetting resin, or a UV / EB curable resin. Examples of thermoplastic resins include polyolefin, polyvinylidene chloride, polyvinylidene chloride, polystyrene, polyvinylacetate, polytetrafluoroethylene, acrylonitrile butadiene styrene, polyacrylic methacrylate, polyamide, nylon, polyacetal, polycarbonate, polybutylene terephthalate, and polyethylene. Examples thereof include terephthalate, polyvinylidene chloride, polysulfone, polyimide, polyamide, mixtures thereof, and copolymers based on these. Examples of thermosetting resins include phenolic resins, epoxy resins, melamine resins, urea resins, unsaturated polyester resins, alkyd resins, polyurethanes, thermosetting polyimides, and mixtures thereof.

(Coating method)
Examples of the coating method include, but are not limited to, spray coating, spin coating, slit coating, roll coating, inkjet, screen, gravure, offset, flexo and other printing methods.

<Recording material, laser>
The coated material can be used as a recording material by irradiating it with a laser beam. The laser beam used for laser marking is not particularly limited as long as it is a near-infrared laser beam, and examples thereof include laser beams such as semiconductor lasers, dye (pulse) lasers, and Alexandrite lasers. Since the salt-forming compound of the present invention has an absorption band in the region of 750 to 950 nm, the wavelength of the laser used is preferably in the range of 750 to 950 nm. The laser irradiation conditions are appropriately selected depending on the coating method, coating conditions, type of base material, and the like.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples as long as the gist of the present invention is not exceeded. In the examples and comparative examples, "parts" and "%" mean "parts by mass" and "% by mass", respectively.

(Method for identifying squarylium [A])
Elemental analysis and MALDITF-MS spectra were used to identify the squarylium [A] used in the present invention. For elemental analysis, a 2400 CHNElemant Analyzer manufactured by PerkinElmer Co., Ltd. was used. For the MALDIOF-MS spectrum, the obtained compound was identified by matching the molecular ion peak of the obtained mass spectrum with the mass number obtained by calculation using the MALDI mass spectrometer autoflex III manufactured by Bruker Daltonics. ..

(Weight average molecular weight (Mw) of resin [B] having a cationic group in the side chain)
The weight average molecular weight (Mw) of the resin [B] having a cationic group in the side chain used in the present invention is a GPC (manufactured by Tosoh Corporation, HLC-) equipped with an RI detector using a TSKgel column (manufactured by Tosoh Corporation). 8120 GPC), polystyrene-equivalent weight average molecular weight (Mw) measured using THF as the developing solvent.

(Quaternary ammonium salt value of resin [B] having a cationic group in the side chain)
The quaternary ammonium salt value of the resin [B] having a cationic group in the side chain used in the present invention was determined by titrating with a 0.1 N silver nitrate aqueous solution using a 5% potassium chromate aqueous solution as an indicator, and then water. It was converted to the equivalent of potassium oxide. The quaternary ammonium salt value of the resin [B] below indicates the quaternary ammonium salt value of the solid content.

<Manufacturing method of squarylium [A]>
(Manufacturing of squarylium [A-1])
To 400 parts of toluene, 40.0 parts of 1,8-diaminonaphthalene, 25.1 parts of cyclohexanone, and 0.087 parts of p-toluenesulfonic acid monohydrate are mixed, heated and stirred in an atmosphere of nitrogen gas, and 3 It was refluxed for hours. The water produced during the reaction was removed from the system by azeotropic distillation. After completion of the reaction, the dark brown solid obtained by distilling toluene was extracted with acetone and purified by recrystallization from a mixed solvent of acetone and ethanol. The obtained brown solid was dissolved in a mixed solvent of 240 parts of toluene and 160 parts of n-butanol, and 13.8 parts of 3,4-dihydroxy-3-cyclobutene-1,2-dione was added to create an atmosphere of nitrogen gas. The mixture was heated and stirred inside, and the mixture was refluxed for 8 hours. The water produced during the reaction was removed from the system by azeotropic distillation. After completion of the reaction, the solvent was distilled and 200 parts of hexane was added while stirring the obtained reaction mixture. The obtained black-brown precipitate was filtered off, washed successively with hexane, ethanol and acetone, and dried under reduced pressure. The obtained black-brown solid was dissolved in 1000 parts of 90% sulfuric acid and stirred at 30 ° C. for 5 hours. After completion of the reaction, the reaction solution was added dropwise to the place where 10000 parts of water was being stirred, and the mixture was stirred at 20 ° C. for 1 hour. The obtained precipitate was separated by filtration, washed with 0.5% hydrochloric acid, and dried under reduced pressure to obtain 70.9 parts (yield: 92%) of squarylium [A-1]. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-1].

Squalilium [A-1]

(Manufacturing of squarylium [A-2])
The same operation as in the production of squalylium [A-1] was performed except that 1000 parts of 98% sulfuric acid was used instead of 1000 parts of 90% sulfuric acid used in the production of squalylium [A-1]. 2] 79.8 parts (yield: 92%) was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-2].

Squalilium [A-2]

(Manufacturing of squarylium [A-3])
The same operation as in the production of squarylium [A-1] was performed except that 1000 parts of 101% sulfuric acid was used instead of 1000 parts of 90% sulfuric acid used in the production of squarylium [A-1]. 3] 87.8 parts (yield: 91%) was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-3].

Squalilium [A-3]

(Manufacturing of squarylium [A-4])
The same operation as in the production of squalylium [A-1] was performed except that 1000 parts of 104.5% sulfuric acid was used instead of 1000 parts of 90% sulfuric acid used in the production of squalylium [A-1]. A-4] 95.6 parts (yield: 90%) was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-4].

Squalilium [A-4]

(Manufacturing of squarylium [A-5])
The same operation as in the production of squarylium [A-2] was performed except that 32.2 parts of 2,6-dimethylcyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squarylium [A-2]. , Squalylium [A-5] 89.8 parts (yield: 96%) was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-5].

Squalilium [A-5]

(Manufacturing of squarylium [A-6])
The same operation as in the production of squarylium [A-1] was performed except that 32.2 parts of 3,5-dimethylcyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squarylium [A-1]. , 82.2 parts of squarylium [A-6] (yield: 98%) was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-6].

Squalilium [A-6]

(Manufacturing of squarylium [A-7])
The same operation as in the production of squalylium [A-2] was performed except that 32.2 parts of 3,5-dimethylcyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squalylium [A-2]. , 90.8 parts of squarylium [A-7] (yield: 97%) was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-7].

Squalilium [A-7]

(Manufacturing of squarylium [A-8])
The same operation as in the production of squalylium [A-3] was performed except that 32.2 parts of 3,5-dimethylcyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squalylium [A-3]. , 98.1 parts of squarylium [A-8] (yield: 95%) was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-8].

Squalilium [A-8]

(Manufacturing of squarylium [A-9])
The same operation as in the production of squarylium [A-4] was performed except that 32.2 parts of 3,5-dimethylcyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squarylium [A-4]. , 106.2 parts of squarylium [A-9] (yield: 94%) was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-9].

Squalilium [A-9]

(Manufacturing of squarylium [A-10])
The same operation as in the production of squalylium [A-2] was performed except that 28.6 parts of 4-methylcyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squalylium [A-2]. [A-10] 85.6 parts (yield: 95%) was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-10].

Squalilium [A-10]

(Manufacturing of squarylium [A-11])
The same operation as in the production of squarylium [A-1], except that 35.8 parts of 3,3,5-trimethylcyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squarylium [A-1]. 81.1 parts (yield: 93%) of squarylium [A-11] was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-11].

Squalilium [A-11]

(Manufacturing of squarylium [A-12])
The same operation as in the production of squarylium [A-2], except that 35.8 parts of 3,3,5-trimethylcyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squarylium [A-2]. To obtain 90.2 parts of squarylium [A-12] (yield: 93%). As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-12].

Squalilium [A-12]

(Manufacturing of squarylium [A-13])
The same operation as in the production of squarylium [A-3], except that 35.8 parts of 3,3,5-trimethylcyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squarylium [A-3]. To obtain 98.1 parts (yield: 92%) of squarylium [A-13]. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-13].

Squalilium [A-13]

(Manufacturing of squarylium [A-14])
The same operation as in the production of squarylium [A-4], except that 35.8 parts of 3,3,5-trimethylcyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squarylium [A-4]. Was carried out to obtain 104.8 parts (yield: 90%) of squarylium [A-14]. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-14].

Squalilium [A-14]

(Manufacturing of squarylium [A-15])
The same operation as in the production of squarylium [A-1] was performed except that 39.4 parts of 3,5-diethylcyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squarylium [A-1]. , Squalylium [A-15] 86.1 parts (yield: 95%) was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-15].

Squalilium [A-15]

(Manufacturing of squarylium [A-16])
The same operation as in the production of squalylium [A-2] was performed except that 39.4 parts of 3,5-diethylcyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squalylium [A-2]. , 94.3 parts of squarylium [A-16] (yield: 94%) was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-16].

Squalilium [A-16]

(Manufacturing of squarylium [A-17])
The same operation as in the production of squalylium [A-3] was performed except that 39.4 parts of 3,5-diethylcyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squalylium [A-3]. , 103.5 parts of squarylium [A-17] (yield: 94%) was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-17].

Squalilium [A-17]

(Manufacturing of squarylium [A-18])
The same operation as in the production of squalylium [A-4] was carried out except that 39.4 parts of 3,5-diethylcyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squalylium [A-4]. , 110.2 parts of squarylium [A-18] (yield: 92%) was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-18].

Squalilium [A-18]

(Manufacturing of squarylium [A-19])
The same operation as in the production of squalylium [A-2], except that 39.4 parts of 5-isopropyl-2-methylcyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squalylium [A-2]. To obtain 93.3 parts (yield: 93%) of squarylium [A-19]. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-19].

Squalilium [A-19]

(Manufacturing of squarylium [A-20])
The same operation as in the production of squalylium [A-2] was performed except that 46.0 parts of 2-cyclohexylcyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squalylium [A-2]. [A-20] 97.1 parts (yield: 91%) was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-20].

Squalilium [A-20]

(Manufacturing of squarylium [A-21])
The same operation as in the production of squalylium [A-2] was performed except that 28.1 parts of 2-norbornanone was used instead of 25.1 parts of cyclohexanone used in the production of squalylium [A-2]. A-21] 82.5 parts (yield: 92%) was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-21].

Squalilium [A-21]

(Manufacturing of squarylium [A-22])
With the production of squalylium [A-2], except that 42.5 parts of spiro [5.5] undecane-1-one was used in place of 25.1 parts of cyclohexanone used in the production of squalylium [A-2]. The same operation was carried out to obtain 97.1 parts (yield: 94%) of squarylium [A-22]. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-22].

Squalilium [A-22]

(Manufacturing of squarylium [A-23])
Instead of 25.1 parts of cyclohexanone used in the production of squarylium [A-2], 3-methyl-3,4,4a, 5,8,8a-hexahydronaphthalene-1 (2H) -one 41.9 parts The same operation as in the production of squarylium [A-2] was carried out except that 93.5 parts (yield: 94%) of squarylium [A-23] was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-23].

Squalilium [A-23]

(Manufacturing of squarylium [A-24])
The same operation as in the production of squarylium [A-2], except that 41.0 parts of 3- (2-chloroethyl) cyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squarylium [A-2]. To obtain 95.8 parts (yield: 94%) of squarylium [A-24]. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-24].

Squalilium [A-24]

(Manufacturing of squarylium [A-25])
With the production of squalylium [A-2], except that 59.8 parts of 3,5-di (trifluoromethyl) cyclohexanone was used in place of 25.1 parts of cyclohexanone used in the production of squalylium [A-2]. The same operation was carried out to obtain 111.4 parts (yield: 93%) of squarylium [A-25]. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-25].

Squalilium [A-25]

(Manufacturing of squarylium [A-26])
The same operation as in the production of squarylium [A-2] was performed except that 44.5 parts of 2-phenylcyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squarylium [A-2]. [A-26] 96.8 parts (yield: 92%) was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-26].

Squalilium [A-26]

(Manufacturing of squarylium [A-27])
The same operation as in the production of squalylium [A-2] was performed except that 48.1 parts of 4-p-tolylcyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squalylium [A-2]. , 102.1 parts (yield: 94%) of squarylium [A-27] was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-27].

Squalilium [A-27]

(Manufacturing of squarylium [A-28])
The same operation as in the production of squalylium [A-2] was carried out except that 48.1 parts of 4-benzylcyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squalylium [A-2]. [A-28] 103.2 parts (yield: 95%) was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-28].

Squalilium [A-28]

(Manufacturing of squarylium [A-29])
The same operation as in the production of squarylium [A-2] was performed except that 36.3 parts of 4-ethoxycyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squarylium [A-2]. [A-29] 88.7 parts (yield: 91%) was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-29].

Squalilium [A-29]

(Manufacturing of squarylium [A-30])
With the production of squarylium [A-2], except that 68.0 parts of 2,6-di (trifluoromethoxy) cyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squarylium [A-2]. The same operation was carried out to obtain 118.6 parts (yield: 93%) of squarylium [A-30]. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-30].

Squalilium [A-30]

(Manufacturing of squarylium [A-31])
The same operation as in the production of squalylium [A-2] was performed except that 48.6 parts of 4-phenoxycyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squalylium [A-2]. [A-31] 100.4 parts (yield: 92%) was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-31].

Squalilium [A-31]

(Manufacturing of squarylium [A-32])
Production of squalylium [A-2], except that 52.4 parts of N-ethyl-3-oxocyclohexane-1-sulfoamide was used in place of 25.1 parts of cyclohexanone used in the production of squalylium [A-2]. The same operation as in the above was carried out to obtain 106.0 parts (yield: 94%) of squarylium [A-32]. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-32].

Squalilium [A-32]

(Manufacturing of squarylium [A-33])
The same operation as in the production of squarylium [A-2] was performed except that 36.3 parts of 4-oxocyclohexanecarboxylic acid was used instead of 25.1 parts of cyclohexanone used in the production of squarylium [A-2]. , 87.7 parts of squarylium [A-33] (yield: 90%) was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-33].

Squalilium [A-33]

(Manufacturing of squarylium [A-34])
The same operation as in the production of squalylium [A-2] was performed except that 43.5 parts of ethyl 2-oxocyclohexanecarboxylic acid was used instead of 25.1 parts of cyclohexanone used in the production of squalylium [A-2]. This was carried out to obtain 96.9 parts of squarylium [A-34] (yield: 93%). As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-34].

Squalilium [A-34]

(Manufacturing of squarylium [A-35])
Similar to the production of squalylium [A-2], except that 46.8 parts of 4-oxo-N-propylcyclohexanecarboxyamide was used instead of 25.1 parts of cyclohexanone used in the production of squalylium [A-2]. Squarylium [A-35] 102.0 (yield: 95%) was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-35].

Squalilium [A-35]

(Manufacturing of squarylium [A-36])
The same operation as in the production of squalylium [A-2] was performed except that 28.9 parts of 4-aminocyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squalylium [A-2]. [A-36] 85.0 parts (yield: 94%) was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-36].

Squalilium [A-36]

(Manufacturing of squarylium [A-37])
The same operation as in the production of squalylium [A-2] was performed except that 36.1 parts of 4- (dimethylamino) cyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squalylium [A-2]. This was carried out to obtain 92.3 parts (yield: 95%) of squarylium [A-37]. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-37].

Squalilium [A-37]

(Manufacturing of squarylium [A-38])
The same operation as in the production of squarylium [A-2] was performed except that 31.4 parts of 4-oxocyclohexanecarbonitrile was used instead of 25.1 parts of cyclohexanone used in the production of squarylium [A-2]. , 85.4 parts of squarylium [A-38] (yield: 92%) was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-38].

Squalilium [A-38]

(Manufacturing of squarylium [A-39])
The same operation as in the production of squalylium [A-2] was performed except that 36.6 parts of 4-nitrocyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squalylium [A-2]. [A-39] 89.9 parts (yield: 92%) was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-39].

Squalilium [A-39]

(Manufacturing of squarylium [A-40])
The same operation as in the production of squarylium [A-2] was performed except that 34.3 parts of 3,5-difluorocyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squarylium [A-2]. , 88.8 parts of squarylium [A-40] (yield: 93%) was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-40].

Squalilium [A-40]

(Manufacturing of squarylium [A-41])
The same operation as in the production of squarylium [A-2] was performed except that 33.9 parts of 2-chlorocyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squarylium [A-2]. [A-41] 87.5 parts (yield: 92%) was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-41].

Squalilium [A-41]

(Manufacturing of squarylium [A-42])
The same operation as in the production of squalylium [A-2] was performed except that 65.4 parts of 3,3-dibromocyclohexanone was used instead of 25.1 parts of cyclohexanone used in the production of squalylium [A-2]. , Squalylium [A-42] 116.3 parts (yield: 93%) was obtained. As a result of mass spectrometry and elemental analysis by TOF-MS, it was identified as squarylium [A-42].

Squalilium [A-42]

Tables 1 and 2 show the results of mass spectrometry and elemental analysis of the squaryliums [A-1] to [A-42] synthesized in the production examples.

<Method for preparing resin [B] having a cationic group in the side chain>
(Preparation of resin [B-1] having a cationic group in the side chain)
67.3 parts of methyl ethyl ketone was placed in a four-neck separable flask equipped with a thermometer, a stirrer, a distillation tube, and a cooler, and the temperature was raised to 75 ° C. under a nitrogen stream. Separately, 33.2 parts of methyl methacrylate, 27.3 parts of n-butyl methacrylate, 27.3 parts of 2-ethylhexyl methacrylate, 12.2 parts of dimethylaminoethylmethyl chloride salt methacrylate, 2,2'-azobis (2,4). -Dimethylvaleronitrile) was made uniform in 6.5 parts and 25.1 parts of methyl ethyl ketone, charged in a dropping funnel, attached to a four-neck separable flask, and added dropwise over 2 hours. Two hours after the completion of the dropping, it was confirmed from the solid content that the polymerization yield was 98% or more and the weight average molecular weight (Mw) was 7500, and the mixture was cooled to 50 ° C. Then, 72 parts of isopropyl alcohol was added to obtain a resin [B-1] having a cationic group in the side chain having a resin component of 40% by mass. The ammonium salt value of the obtained resin was 33 mgKOH / g.

(Preparation of resin [B-2] having a cationic group in the side chain)
67.3 parts of methyl ethyl ketone was placed in a four-neck separable flask equipped with a thermometer, a stirrer, a distillation tube, and a cooler, and the temperature was raised to 75 ° C. under a nitrogen stream. Separately, 22.4 parts of methyl methacrylate, 16.7 parts of n-butyl methacrylate, 27.3 parts of 2-ethylhexyl methacrylate, 15.0 parts of hydrochiethyl methacrylate, 2.5 parts of methacrylic acid, 1.3 parts of t-butyl methacrylate. , 1.3 parts of isobutyl methacrylate, 1.3 parts of cyclohexyl methacrylate, 12.2 parts of dimethylaminoethylmethyl chloride salt methacrylate, 6.5 parts of 2,2'-azobis (2,4-dimethylvaleronitrile), and After making 25.1 parts of methyl ethyl ketone uniform, the mixture was charged into a dropping funnel, attached to a 4-port separable flask, and dropped over 2 hours. Two hours after the completion of the dropping, it was confirmed from the solid content that the polymerization yield was 98% or more and the weight average molecular weight (Mw) was 7950, and the mixture was cooled to 50 ° C. Then, 72 parts of isopropyl alcohol was added to obtain a resin [B-2] having a cationic group in the side chain having a resin component of 40% by mass. The ammonium salt value of the obtained resin was 33 mgKOH / g.

(Preparation of resin [B-3] having a cationic group in the side chain)
67.3 parts of methyl ethyl ketone was placed in a four-neck separable flask equipped with a thermometer, a stirrer, a distillation tube, and a cooler, and the temperature was raised to 75 ° C. under a nitrogen stream. Separately, 21.0 parts of methyl methacrylate, 27.3 parts of n-butyl methacrylate, 27.3 parts of 2-ethylhexyl methacrylate, 22.4 parts of dimethylaminoethylmethyl chloride salt methacrylate, 2,2'-azobis (2,4). -Dimethylvaleronitrile) was made uniform in 6.5 parts and 25.1 parts of methyl ethyl ketone, charged in a dropping funnel, attached to a four-neck separable flask, and added dropwise over 2 hours. Two hours after the completion of the dropping, it was confirmed from the solid content that the polymerization yield was 98% or more and the weight average molecular weight (Mw) was 7640, and the mixture was cooled to 50 ° C. Then, 72 parts of isopropyl alcohol was added to obtain a resin [B-3] having a cationic group in the side chain having a resin component of 40% by mass. The ammonium salt value of the obtained resin was 66 mgKOH / g.

(Preparation of resin [B-4] having a cationic group in the side chain)
62.4 parts of isopropyl alcohol was placed in a 4-port separable flask equipped with a thermometer, a stirrer, a distillation tube, and a cooler, and the temperature was raised to 75 ° C. under a nitrogen stream. Separately, 16.0 parts of methyl methacrylate, 17.0 parts of butyl methacrylate, 16.0 parts of styrene, 51.0 parts of dimethylaminoethylmethyl chloride salt methacrylate, 2,2'-azobis (2,4-dimethylvaleronitrile) After homogenizing 6 parts and 25.0 parts of methyl ethyl ketone, the mixture was charged in a dropping funnel, attached to a 4-neck separable flask, and dropped over 2 hours. Two hours after the completion of the dropping, it was confirmed from the solid content that the polymerization yield was 98% or more and the weight average molecular weight (Mw) was 7050, and the mixture was cooled to 50 ° C. Then, 65 parts of isopropyl alcohol was added to obtain a resin [B-4] having a cationic group in the side chain having a resin component of 40% by mass. The ammonium salt value of the obtained resin was 138 mgKOH / g.

(Preparation of resin [B-5] having a cationic group in the side chain)
62.4 parts of isopropyl alcohol was placed in a 4-port separable flask equipped with a thermometer, a stirrer, a distillation tube, and a cooler, and the temperature was raised to 75 ° C. under a nitrogen stream. Separately, 35.5 parts of methyl methacrylate, 30.0 parts of butyl methacrylate, 16.8 parts of 2-ethylhexyl acrylate, 17.7 parts of dimethylaminopropylmethyl chloride salt methacrylate, 2,2'-azobis (2,4-dimethyl). After homogenizing 5.7 parts of valeronitrile and 15.6 parts of methyl ethyl ketone, the mixture was charged in a dropping funnel, attached to a four-neck separable flask, and dropped over 2 hours. Two hours after the completion of the dropping, it was confirmed from the solid content that the polymerization yield was 98% or more and the weight average molecular weight (Mw) was 7420, and the mixture was cooled to 50 ° C. Then, 72 parts of isopropyl alcohol was added to obtain a resin [B-5] having a cationic group in the side chain having a resin component of 40% by mass. The ammonium salt value of the obtained resin was 45 mgKOH / g.

(Preparation of resin [B-6] having a cationic group in the side chain)
67.3 parts of methyl ethyl ketone was placed in a four-neck separable flask equipped with a thermometer, a stirrer, a distillation tube, and a cooler, and the temperature was raised to 75 ° C. under a nitrogen stream. Separately, 34.7 parts of isobornyl methacrylate, 1.7 parts of n-butyl methacrylate, 30.0 parts of hydrochiethyl methacrylate, 2.5 parts of methacrylic acid, 16.3 parts of t-butyl methacrylate, 2.5 parts of isobutyl methacrylate. After homogenizing 2.3 parts of cyclohexyl methacrylate, 10.0 parts of dimethylaminoethyl methacrylate, 6.5 parts of 2,2'-azobis (2,4-dimethylvaleronitrile), and 25.1 parts of methyl ethyl ketone. It was charged into a dropping funnel, attached to a 4-port separable flask, and dropped over 2 hours. Two hours after the completion of the dropping, it was confirmed from the solid content that the polymerization yield was 98% or more and the weight average molecular weight (Mw) was 6830, and the mixture was cooled to 50 ° C. To this, 3.2 parts of methyl chloride and 22.0 parts of ethanol were added and reacted at 50 ° C. for 2 hours, then heated to 80 ° C. over 1 hour, and further reacted for 2 hours. In this way, a resin [B-6] having a cationic group in the side chain having a resin component of 47% by mass was obtained. The ammonium salt value of the obtained resin was 34 mgKOH / g.

(Preparation of resin [B-7] having a cationic group in the side chain)
67.3 parts of methyl ethyl ketone was placed in a four-neck separable flask equipped with a thermometer, a stirrer, a distillation tube, and a cooler, and the temperature was raised to 75 ° C. under a nitrogen stream. Separately, 60.0 parts of methyl methacrylate, 10.0 parts of n-butyl methacrylate, 10.0 parts of 2-isocyanatoethyl methacrylate, 20.0 parts of N, N-dimethylaminomethylstyrene, 2,2'-azobis (2). , 4-Dimethylvaleronitrile) was made uniform in 6.7 parts and 25.1 parts of methyl ethyl ketone, charged in a dropping funnel, attached to a 4-port separable flask, and added dropwise over 2 hours. Two hours after the completion of the dropping, it was confirmed from the solid content that the polymerization yield was 98% or more and the weight average molecular weight (Mw) was 6770, and the mixture was cooled to 50 ° C. To this, 15.7 parts of benzyl chloride and 22.0 parts of ethanol were added and reacted at 50 ° C. for 2 hours, then heated to 80 ° C. over 1 hour, and further reacted for 2 hours. In this way, a resin [B-7] having a cationic group in the side chain having a resin component of 50% by mass was obtained. The ammonium salt value of the obtained resin was 60 mgKOH / g.

(Preparation of resin [B-8] having a cationic group in the side chain)
62.4 parts of isopropyl alcohol was placed in a 4-port separable flask equipped with a thermometer, a stirrer, a distillation tube, and a cooler, and the temperature was raised to 75 ° C. under a nitrogen stream. Separately, 30.0 parts of methyl methacrylate, 20.0 parts of butyl methacrylate, 15.0 parts of hydroxyethyl methacrylate, 5.0 parts of methacrylic acid, 10.0 parts of styrene, 20.0 parts of N-vinylpyrrolidone, 2,2'. -After homogenizing 4.7 parts of azobis (2,4-dimethylvaleronitrile) and 15.6 parts of isopropyl alcohol, it was charged into a dropping funnel, attached to a four-neck separable flask, and dropped over 2 hours. .. Two hours after the completion of the dropping, it was confirmed from the solid content that the polymerization yield was 98% or more and the weight average molecular weight (Mw) was 7550, and the mixture was cooled to 50 ° C. To this, 9.0 parts of methyl chloride and 22.0 parts of isopropyl alcohol were added, reacted at 50 ° C. for 2 hours, heated to 80 ° C. over 1 hour, and further reacted for 2 hours. Then, 50 parts of isopropyl alcohol was added to obtain a resin [B-8] having a cationic group in the side chain having a resin component of 44% by mass. The ammonium salt value of the obtained resin was 92 mgKOH / g.

Table 3 shows the compositions, ammonium salt values, and weight average molecular weights of the resins [B-1] to [B-8] synthesized in the production examples.

The abbreviations in Table 3 are shown below.
MMA: Methyl methacrylate n-BMA: n-Butyl methacrylate 2-EHMA: 2-Ethylhexyl methacrylate 2-EHA: 2-Ethylhexyl acrylate HEMA: Hydroxyethyl methacrylate MAA: TBMA methacrylate: t-Butyl methacrylate IBMA: Isobutyl methacrylate CHMA: Cyclohexyl Methacrylate IBX: Isobornyl Methacrylate St: Styrene MOI: 2-Isocyanatoethyl Methylhexyl

<Manufacturing method of salt-forming compounds>
[Manufacturing Example 43]
(Production of salt-forming compound 1)
A salt-forming compound 1 composed of squarylium [A-1] and a resin [B-2] having a cationic group was produced by the following procedure. A resin [B-2] having a cationic group in the side chain of 51 parts is added to 2000 parts of water, and the mixture is sufficiently stirred and mixed, and then heated to 60 ° C. On the other hand, an aqueous solution prepared by dissolving 6.03 parts of squarylium [A-1] and 0.85 parts of sodium hydroxide in 90 parts of water is prepared and gradually added dropwise to the resin solution. After the dropping, the mixture is stirred at 60 ° C. for 120 minutes to sufficiently react. To confirm the end point of the reaction, it was judged that the salt-forming compound was obtained by dropping the reaction solution onto the filter paper and using the point where the bleeding disappeared as the end point. After allowing to cool to room temperature with stirring, suction filtration is performed, and after washing with water, the salt-forming compound remaining on the filter paper is dried by removing water with a dryer, and 21 parts of squarylium [A-1] and cations are obtained. A salt-forming compound 1 composed of a resin [B-2] having a sex group was obtained.

[Manufacturing Examples 44 to 84]
(Production of salt-forming compounds 2-42)
Hereinafter, the squarylium [A] and the resin [B] used in the production of the salt-forming compound 1 are the same as those of the salt-forming compound 1 except that the compounds and amounts shown in Table 4 are changed. Got

[Manufacturing Example 85]
(Manufacturing of near-infrared absorbing dye [F-1])
The following near-infrared absorbing dye [F-1] was synthesized based on JP-A-2005-119262.

Near infrared absorbing dye [F-1]

[Manufacturing Example 86]
(Manufacturing of near-infrared absorbing dye [F-2])
The following near-infrared absorbing dye [F-2] was synthesized based on JP-A-11-254830.

Near infrared absorbing dye [F-2]

[Manufacturing Example 87]
(Manufacture of near-infrared absorbing dye [F-3])
The following squarylium [F-3] was synthesized based on JP-A-7-25153.

Near infrared absorbing dye [F-3]

<Manufacturing of composition for laser marking>
[Example 1] (Laser marking composition LM-1)
(Preparation of 10% polyvinyl alcohol aqueous solution)
A 10% polyvinyl alcohol aqueous solution, which is a resin (E), is prepared by adding 50 parts of polyvinyl alcohol and 450 parts of water manufactured by Wako Pure Chemical Industries, Ltd. to a 1 L beaker and heating and stirring at 50 ° C. for 30 minutes. did.

(Preparation of salt-forming compound dispersion)
The mixture having the following composition was uniformly stirred and mixed, dispersed with an Eiger mill for 3 hours using zirconia beads having a diameter of 0.5 mm, and then filtered through a filter of 0.5 μm to prepare a salt-forming compound dispersion.
Salt-forming compound 14 parts (E) 10% polyvinyl alcohol solution 122 parts Water 74 parts

(Adjustment of color former [C] dispersion)
The mixture having the following composition is uniformly stirred and mixed, dispersed with an Eiger mill for 3 hours using zirconia beads having a diameter of 0.5 mm, and then filtered through a filter of 0.5 μm to prepare a color former [C] dispersion. did.
(C) 3,3'-Bis (4-dimethylaminophenyl) -6-dimethylaminophthalide
60 parts (E) 10% polyvinyl alcohol solution 100 parts Water 40 parts

(Adjustment of color developer [D] dispersion)
The mixture having the following composition is uniformly stirred and mixed, dispersed with an Eiger mill for 3 hours using zirconia beads having a diameter of 0.5 mm, and then filtered through a filter of 0.5 μm to obtain a color developer [D] dispersion. Made.
(D) 4-Hydroxy-4'-isopropoxydiphenyl sulfone
40 parts (E) 10% polyvinyl alcohol solution (E) 100 parts Water 60 parts

(Adjustment of composition LM-1 for laser marking)
The dispersion produced by the above method was mixed at the following ratio to obtain a laser marking composition (LM-1).
Salt-forming compound dispersion 5 parts Color-developing agent [C] dispersion 40 parts Color-developing agent [D] dispersion 10 parts

[Examples 2-56, Comparative Examples 1-3] (Laser marking compositions LM-2 to 59)
The composition for laser marking is the same as that of LM-1, except that the types and amounts of the salt-forming compound 1, the color former [C], and the color developer [D] are changed to the compounds and parts by mass shown in Table 5. The products LM-2 to 59 were obtained.

<Evaluation of composition for laser marking>
The following evaluations were carried out on the obtained laser marking compositions LM-1 to 59. The results are shown in Table 6.

(Viscosity evaluation)
The obtained composition for laser marking was measured for viscosity at 25 ° C. using an E-type viscometer (“ELD-type viscometer” manufactured by Toki Sangyo Co., Ltd.). Evaluation was made based on the following criteria.
⊚: Less than 5 mPa · s ○: 5 mPa · s or more and less than 10 mPa · s Δ: 10 mPa · s or more, less than 30 mPa · s ×: 30 mPa · s or more

(Storage stability)
The obtained laser marking composition was stored in a thermostat at 60 ° C. for 1 week, accelerated over time, and then the change in ink viscosity before and after the time was measured. The viscosity of the ink was measured using an E-type viscometer (“ELD-type viscometer” manufactured by Toki Sangyo Co., Ltd.) under the condition of a rotation speed of 50 rpm at 25 ° C. Evaluation was made based on the following criteria.
⊚: Change rate is less than ± 3% ○: Change rate is ± 3% or more and less than ± 5% △: Change rate is ± 5% or more and less than ± 15% ×: Change rate is ± 15% or more

(Near infrared absorption capacity)
The obtained composition for laser marking was diluted 1000 times with water, and then the absorption spectrum in the wavelength range of 300 to 1000 nm was measured using a spectrophotometer (U-4100, manufactured by Hitachi High-Technologies Corporation). At that time, a 10 mm square quartz cell was used as the UV cell. The maximum absorption of the salt-forming compound of the present invention is in the region of 750 to 950 nm, and the near-infrared absorbing ability was evaluated based on the absorbance at the maximum absorption wavelength according to the following criteria. At the same concentration, the higher the absorbance at the maximum absorption wavelength, the better the near-infrared absorption capacity. The higher the near-infrared absorbing capacity, the more efficiently the laser light can be converted into heat, so that the color development property in laser marking is improved. In other words, it also leads to a reduction in the amount of the near-infrared absorbing dye added.
⊚: Absorbance at the maximum absorption wavelength is 1.0 or more ○: Absorbance at the maximum absorption wavelength is 0.6 or more and less than 1.0 Δ: Absorbance at the maximum absorption wavelength is 0.3 or more and less than 0.6 ×: At the maximum absorption wavelength Absorbance is less than 0.3

(Invisibility)
Using the absorption spectrum in the wavelength range of 300 to 1000 nm obtained by the above method, the invisibility is determined by the following criteria based on the "average absorbance at 400 to 700 nm" when the absorbance at the maximum absorption wavelength is standardized to 1. Evaluated in.
⊚: 0.05 or less ○: 0.05 or more and less than 0.075 Δ: 0.075 or more and less than 0.1 ×: 0.1 or more

The composition for laser marking containing the salt-forming compound of the present invention exhibited excellent viscosity, storage stability, near-infrared absorption ability, and invisibility. In particular, a composition for laser marking containing salt-forming compounds 6 to 9, 11 to 14, 43, 44 in which X ₃ , X ₄ , X ₇ and X ₈ of the cyclo ring of squarylium [A] are substituted with methyl groups The result was extremely good. Among them, the composition for laser marking having the salt-forming compounds 6, 7, 11, 12, 43, 44 having the substitution number n = 1 or 2 of the sulfo group has viscosity, storage stability, near-infrared absorption ability, and The results were particularly good with respect to invisibility. Further, the salt-forming compound using the resin [B-1 to 3, 5 to 8] having an ammonium salt value of 20 or more and 130 or less mgKOH / g was excellent in dispersibility, and particularly good in storage stability.

The composition for laser marking of the present invention has very good viscosity and storage stability, which is derived from the fact that the salt-forming compound of the present invention is easily dispersed and easily dissolved. Therefore, the composition for laser marking using the salt-forming compound of the present invention is excellent in stability as an ink without depending on the composition and process, and in particular, the storage stability is remarkably good, so that the ink is long-term. Can be stored. Furthermore, since the near-infrared absorbing ability is high, efficient heat conversion becomes possible, that is, the amount of the near-infrared absorbing dye added can be reduced. In addition, since the invisibility is high, it is difficult to visually confirm the coated portion, and the color difference before and after laser irradiation becomes large. That is, the color development property is improved. In addition, its high invisibility makes it possible to use it for security purposes.

<Manufacturing of laser marking coating>
[Examples 57 to 112, Comparative Examples 4 to 6]
(Manufacturing of laser marking coated products P-1 to 59)
The obtained laser marking composition LM-1 to 59 was solidly coated on plain paper with a bar coater so as to have a dry coating amount of 5.0 g / m ^2, and dried in an oven at 60 ° C. for 1 minute. Coatings P-1 to 46 were obtained.

<Evaluation of laser marking coating>
The following evaluations were carried out on the obtained laser marking coated products P-1 to 59. The results are shown in Table 7.

(Color development)
The obtained laser marking coated product was irradiated with laser light under the conditions of a laser wavelength of 808 nm, a laser scanning speed of 10 mm / sec, and a laser output of 50 mW to draw clear lines derived from a color former. The color development of the obtained lines was visually compared and evaluated according to the following criteria. 〇 and above are at a level sufficient for practical use, and ◎ is able to draw extremely high-concentration lines, and it is possible to reduce near-infrared absorbing dyes.
⊚: The density is very high, and extremely clear lines can be drawn.
◯: The density is high and clear lines can be drawn.
Δ: The line can be visually confirmed.
X: The concentration is low and it is difficult to identify.

The composition for laser marking containing the salt-forming compound of the present invention exhibited extremely excellent color development. In particular, a composition for laser marking containing salt-forming compounds 6 to 9, 11 to 14, 43, 44 in which X ₃ , X ₄ , X ₇ and X ₈ of the cyclo ring of squarylium [A] are substituted with methyl groups. The coated material used was extremely good, and very high-concentration lines were drawn, and it is considered that the amount of addition can be easily reduced. On the other hand, in the case of the near-infrared absorbing dye which is not the present invention, the color-developing property at a practical level has not been obtained except for Comparative Example 5 in which the near-infrared absorbing dye [F-2] is used. Further, as described above, the near-infrared absorbing dye [F-2] has not reached the practical level because of problems in viscosity and storage stability as ink. The composition for laser marking of the present invention has both "stability as an ink" and "optical characteristics", and is also extremely excellent in color development when laser marking is performed.

Claims (7)

A salt-forming compound of a squarylium [A] represented by the following general formula (1) and a resin [B] having a cationic group in the side chain, a color former [C], a color developer [D] and a resin [E]. A composition for laser marking , wherein the resin [B] having a cationic group in the side chain is a vinyl-based resin containing a structural unit represented by the following general formula (2) .
General formula (1)


[In the general formula (1), X _{1 to} X ₁₀ each independently have a hydrogen atom, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, and a substituent. Aryl group which may have a substituent, an aralkyl group which may have a substituent, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent, an amino group, a substituted amino group, and -SO ₂ NR. ₁ R ₂ , -COOR ₃ , -CONR ₄ R ₅ , represents a nitro group, a cyano group or a halogen atom, and adjacent groups may form a ring. R _{1 to} R ₅ each independently represent an alkyl group which may have a hydrogen atom or a substituent. n represents an integer of 1 to 4. Z ⁺ represents a hydrogen ion or an inorganic or organic cation. ]
General formula (2)


[In the general formula (2), R ₆ represents an alkyl group which may have a hydrogen atom or a substituent. R _{7 to} R ₉ each independently represent a hydrogen atom, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or an aryl group which may have a substituent, and R Two of _{7 to} R ₉ may be bonded to each other to form a ring. Q is an alkylene group, an arylene group, _{-CONH-R 10} - or _{-COO-R 11} - _{represents, R 10} and _{R 11} represents an alkylene group. Y ⁻ represents an inorganic or organic anion. ] The composition for laser marking according to claim 1 , wherein n in the general formula (1) is 1 or 2. The composition for laser marking according to claim 1 or 2 , wherein the quaternary ammonium salt value of the solid content of the resin [B] having a cationic group in the side chain is 20 to 130 mgKOH / g. Claim 1 in which the content of the salt-forming compound of the squarylium [A] and the resin [B] having a cationic group in the side chain is 0.05 to 5% by mass in the total solid content of the composition for laser marking. ~ 3 The composition for laser marking according to any one of the items. A coated product obtained by coating the composition for laser marking according to any one of claims 1 to 4 . A recording material obtained by irradiating the coated object according to claim 5 with a laser beam and recording the material. A recording method for recording by irradiating a coated object according to claim 5 with a laser beam.