JP7794055B2 - UV absorbers and their uses - Google Patents

Description

The present invention relates to an ultraviolet absorber.

Various polymer materials are widely used for a variety of purposes, including as molded bodies, films, and coating materials. However, it is known that the action of ultraviolet rays contained in sunlight, etc., can cause discoloration and deterioration in mechanical strength and other quality issues for these materials. For this reason, ultraviolet absorbers are blended into various polymer materials to prevent quality deterioration.

For example, UV absorbers are incorporated into packaging materials for pharmaceuticals, cosmetics, etc. to protect the packaging material itself and the organic matter contained within from deterioration and decomposition. Furthermore, in display devices, UV absorbers are commonly added to optical films such as polarizing plate protective films to prevent discoloration of these optical films. UV absorbers have also traditionally been incorporated into coating compositions such as paints and adhesives to prevent deterioration due to UV rays.

However, simply blending an ultraviolet absorber into a polymer material can cause the ultraviolet absorber to bleed over time, making it unsuitable for use in packaging for pharmaceuticals, cosmetics, etc. due to their impact on the human body.

In addition, when polymer materials containing UV absorbers are molded or coated by heat treatment, the UV absorbers often undergo thermal decomposition, preventing them from exerting their intended effect. Therefore, there is a demand for UV absorbers with sufficient heat resistance.

However, it has been pointed out that not only ultraviolet light with wavelengths of less than 400 nm from sunlight, but also light in the short wavelength visible light range of around 400 to 420 nm, can cause damage to organic matter and the human body. Therefore, for certain applications, including those mentioned above, there is a demand for ultraviolet absorbers that can absorb light in the short wavelength visible light range.

One known method for preventing UV absorber bleeding is to convert the UV absorber into a UV-absorbing unsaturated monomer and then polymerize it to form a polymer. UV absorbers include benzophenone-based, benzotriazole-based, and triazine-based UV absorbers, and triazine-based UV absorbers are known to have high heat resistance.

For example, Patent Document 1 discloses a triazine-based UV absorber having a (meth)acryloyl group capable of radical polymerization. In the synthesis method of Patent Document 1, when converting a triazine-based UV absorber into an unsaturated monomer, the large number of hydroxy groups that serve as reaction sites tends to result in low monofunctionality of the polymerizable group, making reaction control difficult. It is difficult to control the polymerization of UV absorbers with low monofunctionality, making it impossible to properly design a UV-absorbing polymer.

Patent Document 2 discloses a triazine-based UV absorber that has excellent heat resistance and bleeding resistance due to the linking of triazine skeletons. Furthermore, Patent Document 3 discloses a triazine-based UV absorber that absorbs UV rays in the long wavelength region and has excellent heat resistance. However, the UV absorption properties of these triazine-based UV absorbers in the short wavelength region of visible light are not fully satisfactory, their bleeding resistance is insufficient, and because they do not have polymerizable groups, bleeding cannot be suppressed by polymerization.

Furthermore, triazine-based UV absorbers tend to have higher heat resistance, but also higher colorability, the more hydroxy groups on the aromatic ring bonded to the triazine ring that can form hydrogen bonds with the nitrogen atom of the triazine ring. The triazine-based UV absorbers disclosed in these patent documents cannot be said to have sufficient heat resistance and colorability at the same time.

WO2018/216750 JP 2016-113445 A JP 2017-132948 A

The present invention aims to provide an ultraviolet absorber that absorbs light in the ultraviolet region below 400 nm and the short wavelength visible region of 400 to 420 nm, and has excellent heat resistance, bleeding resistance, and low coloration.

The present invention relates to an ultraviolet absorber having a triazine ring directly bonded to a hydroxynaphthyl group, wherein the hydroxynaphthyl group is a group having a structure represented by the following general formula (1):
General formula (1) *-X-Y-Z
(In the formula, X represents —COO— or —CONH—, Y represents a divalent linking group, Z represents a polymerizable unsaturated group, and * represents a bond to the hydroxynaphthyl group.)

The present invention also relates to the above-mentioned ultraviolet absorber, wherein the polymerizable unsaturated group is one selected from the group consisting of a vinyl group, a (meth)allyl group, and a (meth)acryloyl group.

The present invention also relates to an ultraviolet absorber that is a polymer of the ultraviolet absorber.

The present invention also relates to an ultraviolet absorber that is a copolymer of the ultraviolet absorber and another monomer.

The present invention also relates to an ultraviolet-absorbing molding agent containing the ultraviolet absorber.

The present invention also relates to an ultraviolet-absorbing coating agent containing the ultraviolet absorber.

The present invention provides ultraviolet absorbers and ultraviolet-absorbing coating agents that absorb light in the ultraviolet region below 400 nm and in the short-wavelength visible region of 400 to 420 nm, and have excellent heat resistance, bleeding resistance, and low coloration.

<Ultraviolet absorber>
The ultraviolet absorber of the present invention can absorb light in the visible light short wavelength region of about 400 to 420 nm, in addition to the ultraviolet region of less than 400 nm, due to the action of the naphthalene ring bonded to the triazine ring. It is preferable that the naphthalene ring is directly bonded to the triazine ring without a linking group. It is more preferable that at least one of the one, two, or three naphthalene rings directly bonded to the triazine ring contains a hydroxy group at the 2-position. It is more preferable that the number of naphthalene rings having a hydroxy group at the 2-position directly bonded to the triazine ring is one. As the number of naphthalene rings having a hydroxy group at the 2-position directly bonded to the triazine ring increases, heat resistance tends to improve, but colorability tends to increase.

The ultraviolet absorber of the present invention may be in the form of a monomer or a polymer. The monomeric ultraviolet absorber of the present invention is an ultraviolet absorber having a triazine ring directly bonded to a hydroxy naphthyl group, and is an ultraviolet absorber represented by the following general formula (2), general formula (3), or general formula (4), in which the hydroxy naphthyl group has a structure represented by the following general formula (1):
General formula (1) *-X-Y-Z
(In the formula, X represents —COO— or —CONH—, Y represents a divalent linking group, Z represents a polymerizable unsaturated group, and * represents a bond to the hydroxynaphthyl group.)

In the general formulas (2) to (4), R _1b to R _1g , R _2a to R _2g , and R _3a to R _3g each independently represent a hydrogen atom, a hydroxy group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a nitrile group, a nitro group, a carboxyl group, a sulfo group, R ₇ , a substituted or unsubstituted aryl group, or a group represented by the general formula (1).

In general formula (1), X is an ester group or amide group represented by -COO- or -CONH-. * indicates a bond to the hydroxynaphthyl group. By directly bonding such an electron-withdrawing group to the hydroxynaphthalene ring, the heat resistance of the UV absorber can be improved and its colorability can be reduced.

The linking group Y in general formula (1) is an alkylene group having 1 to 20 carbon atoms or an arylene group having 1 to 20 carbon atoms, which may have a substituent such as a hydroxy group, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an aryloxy group having 6 to 20 carbon atoms. Between carbon atoms of the alkylene group having 1 to 20 carbon atoms, one or more cycloalkylene groups having 6 to 20 carbon atoms, arylene groups having 6 to 20 carbon atoms, carbonyl groups, ether bonds, ester bonds, carbonate ester bonds, amide bonds, urethane bonds, urea bonds, or bonds represented by the following general formulas (Y-1) to (Y-6) may be connected.

Z in general formula (1) is a vinyl group, a (meth)allyl group, or a (meth)acryloyl group, and is represented by the following general formulas (Z-1) to (Z-5). From the perspective of versatility in polymerization, (meth)acryloyl groups represented by general formulas (Z-4) and (Z-5) are preferred.

_R7 is an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkyleneoxy group having 1 to 20 carbon atoms, or an alkenyloxy group having 1 to 20 carbon atoms, which may have a substituent such as a hydroxy group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a nitrile group, a nitro group, a carboxyl group, or a sulfo group, and the carbon atoms of the alkyl group having 1 to 20 carbon atoms, alkenyl group having 1 to 20 carbon atoms, alkoxy group having 1 to 20 carbon atoms, alkyleneoxy group having 1 to 20 carbon atoms, or alkenyloxy group having 1 to 20 carbon atoms may be linked between their carbon atoms by one or more carbonyl groups, ether bonds, ester bonds, carbonate ester bonds, amide bonds, urethane bonds, or urea bonds.

The substituted or unsubstituted aryl group is an aryl group having 6 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, or a biphenyl group, and may have a substituent such as a hydroxy group, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a nitrile group, a nitro group, a carboxyl group, or a sulfo group.

Examples of compounds represented by general formula (2) include the following compounds, but the UV absorbers of the present invention are not limited to these compounds.

Examples of the compound represented by formula (4) include the following compounds, but the ultraviolet absorber of the present invention is not limited to these compounds.
(A-11)

The synthesis method for the triazine-based ultraviolet absorber is not particularly limited, and the absorber can be synthesized using known synthesis methods for compounds having a triazine structure. For example, a method of subjecting cyanuric chloride or a cyanuric chloride derivative to a substitution reaction with naphthol or a naphthol derivative using aluminum trichloride can be mentioned. Another example is a method of subjecting methyl 2-hydroxy-1-naphthoate and benzamidine hydrochloride to a condensation ring reaction using sodium methoxide. The substituents on the naphthalene ring linked to the triazine ring via a single bond and on R ₄ , R ₅ , and R ₆ can be introduced after or before the triazine structure is formed.

The method for introducing the substituent represented by general formula (1) is not particularly limited, and known methods can be used. Examples include the introduction of an ester bond by an addition reaction of a carboxylic acid to an epoxy compound, the introduction of an ester bond or an amide bond by a reaction of an acid chloride with an alcohol or an amine, and the introduction of an ester bond by a transesterification reaction of a carboxylic acid or a carboxylic acid ester with an alcohol. The substituent represented by general formula (1) may be introduced after or before the triazine structure is formed.

The purification method for these triazine-based UV absorbers is not particularly limited, and methods such as distillation, recrystallization, reprecipitation, and the use of filtering materials and adsorbents can be used.

<Ultraviolet absorbing polymer>
The ultraviolet absorber of the present invention may be in the form of a polymer. The ultraviolet absorber in the form of a monomer represented by general formula (1) has a polymerizable unsaturated group, and therefore, the polymerizable unsaturated group can be polymerized to form an ultraviolet absorbing polymer.
The ultraviolet-absorbing polymer absorbs light in the ultraviolet region of less than 400 nm and in the short wavelength visible region of 400 to 420 nm by containing the ultraviolet absorber in the monomer form of the present invention as a monomer component. Polymerizing the ultraviolet absorber makes it possible to obtain an ultraviolet absorber with excellent heat resistance and bleeding resistance, making it a material more suitable for molding resin compositions and coating compositions.

The ultraviolet-absorbing polymer of the present invention may be obtained by homopolymerizing the monomeric ultraviolet absorber of the present invention, or by copolymerizing it with other monomers. When blended into a molding resin composition or a coating composition, it is preferable to copolymerize the ultraviolet absorber of the present invention with other monomers.

When the monomeric UV absorber of the present invention is copolymerized with other monomers, the monomeric UV absorber is preferably contained in the monomeric component at 20 to 80% by mass, assuming that the total monomer component, including the monomeric UV absorber, is 100% by mass. If it is less than 20% by mass, the UV absorption effect is low, and if it is more than 80% by mass, compatibility with the base resin to be blended tends to be poor.

Other monomers include, for example, (meth)acrylic acid esters, crotonate esters, vinyl esters, maleic acid diesters, fumaric acid diesters, itaconic acid diesters, (meth)acrylamides, vinyl ethers, vinyl alcohol esters, styrenes, (meth)acrylonitrile, acidic group-containing monomers, monomers having a hindered amine photostable structure, and ultraviolet-absorbing unsaturated monomers other than those of the present invention.

(Meth)acrylic acid esters include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, tert-butylcyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 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 Examples of suitable acrylates include diethylene glycol monoethyl ether (meth)acrylate, triethylene glycol monomethyl ether (meth)acrylate, triethylene glycol monoethyl ether (meth)acrylate, polyethylene glycol monomethyl ether (meth)acrylate, polyethylene glycol monoethyl ether (meth)acrylate, β-phenoxyethoxyethyl (meth)acrylate, nonylphenoxy polyethylene glycol (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, trifluoroethyl (meth)acrylate, octafluoropentyl (meth)acrylate, perfluorooctylethyl (meth)acrylate, dicyclopentanyl (meth)acrylate, tribromophenyl (meth)acrylate, tribromophenyloxyethyl (meth)acrylate, glycidyl (meth)acrylate, 4-(2,3-epoxypropoxy)butyl (meth)acrylate, and 1,4-cyclohexanedimethanol mono(meth)acrylate.

Examples of crotonate esters include n-butyl crotonate, isobutyl crotonate, sec-butyl crotonate, tert-butyl crotonate, and hexyl crotonate.

Examples of vinyl esters include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl methoxyacetate, and vinyl benzoate.

Examples of maleic acid diesters include dimethyl maleate, diethyl maleate, and dibutyl maleate.

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

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

Examples of (meth)acrylamides include (meth)acrylamide, N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-propyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N-n-butylacryl(meth)amide, N-tert-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)acryloylmorpholine, and diacetone acrylamide.

Examples of vinyl ethers include methyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, and methoxyethyl vinyl ether.

Examples of styrenes include styrene, methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, isopropylstyrene, butylstyrene, hydroxystyrene, methoxystyrene, butoxystyrene, acetoxystyrene, chlorostyrene, dichlorostyrene, bromostyrene, chloromethylstyrene, hydroxystyrene protected with a group that can be deprotected with an acidic substance (e.g., t-Boc), methyl vinylbenzoate, and α-methylstyrene.

Examples of acidic group-containing monomers include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, α-chloroacrylic acid, and cinnamic acid; unsaturated dicarboxylic acids or acid anhydrides such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, and mesaconic acid; tri- or higher carboxylic acid unsaturated polycarboxylic acids or acid anhydrides; mono[(meth)acryloyloxyalkyl] esters of di- or higher carboxylic acid polyhydric acids such as mono(2-acryloyloxyethyl) succinate, mono(2-methacryloyloxyethyl) succinate, mono(2-acryloyloxyethyl) phthalate, and mono(2-methacryloyloxyethyl) phthalate; and mono(meth)acrylates of polymers with carboxy terminals such as ω-carboxy-polycaprolactone monoacrylate and ω-carboxy-polycaprolactone monomethacrylate.

Examples of monomers having a hindered amine light-stable structure include, but are not limited to, 4-(meth)acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 4-(meth)acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4-(meth)acryloylamino-1,2,2,6,6-pentamethylpiperidine, 4-cyano-4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, and 4-crotonoylamino-2,2,6,6-tetramethylpiperidine. These may be used alone or in appropriate combinations of two or more types, if necessary.

Copolymerizing these monomers with a hindered amine light-stable structure can further improve light stability. It is more preferable for them to be included in the copolymer composition at 3 to 40% by weight. Less than 3% by weight is less effective at ensuring light stability, while more than 40% by weight tends to result in increased hydrophilicity and poor compatibility.

Examples of ultraviolet absorbing unsaturated monomers other than those of the present invention include 4-acryloyloxybenzophenone, 4-methacryloyloxybenzophenone, 2-hydroxy-4-acryloyloxybenzophenone, 2-hydroxy-4-methacryloyloxybenzophenone, 2-hydroxy-4-(2-acryloyloxy)ethoxybenzophenone, 2-hydroxy-4-(2-methacryloyloxy)ethoxybenzophenone, 2-hydroxy-4-(2-methyl-2-acryloyloxy)ethoxybenzophenone, 2,2' -dihydroxy-4-methacryloyloxybenzophenone and other benzophenone-based unsaturated monomers; 2-[2'-hydroxy-5'-(methacryloyloxymethyl)phenyl]-2H-benzotriazole, 2-[2'-hydroxy-5'-(methacryloyloxyethyl)phenyl]-2H-benzotriazole, 2-[2'-hydroxy-5'-(methacryloyloxypropyl)phenyl]-2H-benzotriazole, 2-[2'-hydroxy-3'-tert-butyl-5'-(methacryloyloxyethyl)phenyl]-2H-benzotriazole, 2-[2'-hydroxy-5'-tert-butyl-3'-(methacryloyloxyethyl)phenyl]-2H-benzotriazole,
Benzotriazole-based unsaturated monomers such as 2-[2'-hydroxy-5'-(β-methacryloyloxyethoxy)-3'-tert-butylphenyl]-4-tert-butyl-2H-benzotriazole are also included.

(UV absorbing molding agent)
The ultraviolet-absorbing polymer can also be used as an ultraviolet-absorbing molding agent. The ultraviolet-absorbing molding agent may be used alone, or may be used as a molding resin composition comprising a polyolefin and the ultraviolet-absorbing polymer. When used alone or mixed with a polyolefin, the ultraviolet-absorbing polymer preferably contains an unsaturated monomer represented by general formula (5) and/or (6) in its copolymer composition.

General formula (5)

(In the formula, _R8 represents a hydrogen atom or a methyl group, and _R9 represents a hydrocarbon group having 18 or less carbon atoms.)

General formula (6)

(In the formula, R ₁₀ represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms.)
The unsaturated monomer represented by general formula (5) plays a role in ensuring compatibility with polyolefins. When _R9 is a hydrocarbon group having 18 or less carbon atoms, the crystallinity of the unsaturated monomer represented by general formula (5) is relatively suppressed, ensuring high compatibility with polyolefins.
In the general formula (5), examples of R ₉ , which is a hydrocarbon group having 18 or less carbon atoms, include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, a sec-pentyl group, a tert-pentyl group, a 3-pentyl group, an isopentyl group, a neopentyl group, an n-hexyl group, a 2-methylpentyl group, a 3-methylpentyl group, a 2,2-dimethylbutyl group, a 2,3-dimethylbutyl group, an n-heptyl group, a 2-methylhexyl group, a 3-methylhexyl group, a 2,2-dimethylpentyl group, a 2,3-dimethylpentyl group, a 2,4-dimethylpentyl group, Examples of such alkyl groups include linear or branched alkyl groups such as 3,3-dimethylpentyl, 3-ethylpentyl, 2,2,3-trimethylbutyl, n-octyl, 2-ethylhexyl, isooctyl, tert-octyl, n-nonyl, isononyl, decyl, isodecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl; alicyclic hydrocarbon groups such as cyclododecyl; and polycyclic hydrocarbon groups such as isobornyl, dicyclopentanyl, dicyclopentenyl, and adamantyl. Among these, hydrocarbon groups having 10 or fewer carbon atoms are preferred.

Specific examples of unsaturated monomers represented by general formula (5) include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, t-octyl (meth)acrylate, and isopropyl (meth)acrylate. Examples include octyl, nonyl (meth)acrylate, dodecyl (meth)acrylate, lauryl (meth)acrylate, octadecyl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, cyclohexyl (meth)acrylate, tert-butylcyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and adamantyl (meth)acrylate.

This unsaturated monomer represented by general formula (6) also plays a role in ensuring compatibility with polyolefins.

Specific examples of unsaturated monomers represented by general formula (6) include styrene and vinyltoluene.

The unsaturated monomers represented by general formula (5) and/or (6) are preferably contained in the copolymer composition in an amount of 20% by weight or more. If the amount is less than 20% by weight, the effect of ensuring compatibility tends to be reduced.

Ultraviolet-absorbing polymers can be synthesized by anionic polymerization, cationic polymerization, free radical polymerization, living anionic polymerization, living cationic polymerization, and living radical polymerization. Of these, free radical polymerization and living radical polymerization are preferred.

Free radical polymerization preferably uses a polymerization initiator. Examples of the polymerization initiator include azo compounds and peroxides. Examples of azo compounds include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 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), and 2,2'-azobis[2-(2-imidazolin-2-yl)propane]. Examples of peroxides include benzoyl peroxide, tert-butyl perbenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di(2-ethoxyethyl)peroxydicarbonate, tert-butyl peroxyneodecanoate, tert-butyl peroxypivalate, (3,5,5-trimethylhexanoyl)peroxide, dipropionyl peroxide, and diacetyl peroxide. Polymerization initiators can be used alone or in combination. The reaction temperature is preferably 40 to 150°C, more preferably 50 to 110°C. The reaction time is preferably 3 to 30 hours, more preferably 5 to 20 hours.

Living radical polymerization suppresses the side reactions that occur in general radical polymerization, and furthermore, because polymerization growth occurs uniformly, it is possible to easily synthesize block polymers and resins with uniform molecular weights.

Living radical polymerization is preferably carried out using an organic halide or a sulfonyl halide compound as an initiator and a transition metal complex as a catalyst, since it can be used with a wide range of monomers and can employ a polymerization temperature that is compatible with existing equipment. Atom transfer radical polymerization can be carried out by the methods described in the following references 1 to 8, etc.
(Reference 1) Fukuda et al., Prog. Polym. Sci. 2004, 29, 329
(Reference 2) Matyjaszewski et al., Chem. Rev. 2001, 101, 2921
(Reference 3) Matyjaszewski et al., J. Am. Chem. Soc. 1995, 117, 5614
(Reference 4) Macromolecules 1995, 28, 7901, Science 1996, 272, 866
(Reference 5) International Publication No. 96/030421 (Reference 6) International Publication No. 97/018247 (Reference 7) Japanese Patent Application Laid-Open No. 9-208616 (Reference 8) Japanese Patent Application Laid-Open No. 8-41117

An organic solvent is preferably used in the synthesis of the UV-absorbing polymer. Examples of organic solvents include ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, xylene, acetone, hexane, methyl ethyl ketone, cyclohexanone, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, and diethylene glycol monobutyl ether acetate. Organic solvents can be used alone or in combination of two or more.

The molecular weight of the ultraviolet-absorbing polymer is preferably a weight-average molecular weight of 5,000 to 200,000, more preferably 5,000 to 100,000, as measured by gel permeation chromatography (GPC).

UV-absorbing polymers can be molded with polyolefins.

<Polyolefin>
Polyolefins include polyethylene, polypropylene, polybutene-1, and poly-4-methylpentene, and copolymers thereof.
Examples of polyethylene include low-density polyethylene and high-density polyethylene.
The polypropylene may be, for example, crystalline or amorphous polypropylene.
Examples of copolymers using these include ethylene-propylene random, block or graft copolymers, copolymers of α-olefins and ethylene or propylene, ethylene-vinyl acetate copolymers, ethylene-methyl acrylate copolymers, ethylene-ethyl acrylate copolymers, and ethylene-acrylic acid copolymers.
Among these, crystalline or amorphous polypropylene, ethylene-propylene random, block or graft copolymers are preferred, and propylene-ethylene block copolymers are more preferred. Furthermore, polypropylene-based resins are preferred from the viewpoints of being inexpensive and having a small specific gravity, which allows for the weight reduction of molded articles.

The number average molecular weight of polyolefins is approximately 30,000 to 500,000.

The melt flow rate (MFR) of the polyolefin is preferably 1 to 100 (g/10 min). Note that the MFR is a value determined in accordance with JIS K-7210.

The content of the ultraviolet-absorbing polymer is preferably 0.01 to 10 parts by mass per 100 parts by mass of polyolefin.

The UV-absorbing molding agent of the present invention may contain wax.

Examples of waxes include polyethylene wax and polypropylene wax. The melting point of the wax is preferably 50 to 180°C, more preferably 80 to 170°C. The melting point of the wax is measured in a nitrogen atmosphere using a differential scanning calorimeter. Polyolefins are compounds that do not have a melting point but do have a softening point.

The number average molecular weight of the wax is preferably 500 to 25,000, and more preferably 1,000 to 15,000. The number average molecular weight is measured in accordance with JIS K2207:1996 (Japanese Industrial Standards).

The wax content is preferably 0.1 to 10 parts by mass per 100 parts by mass of polyolefin.

The molding resin composition of the present invention is preferably produced, for example, as a masterbatch containing a high concentration of ultraviolet-absorbing polymer. The masterbatch can be produced, for example, by melt-kneading the ultraviolet-absorbing polymer and polyolefin and pelletizing them using a pelletizer. To prevent aggregation of the ultraviolet-absorbing polymer, it is preferable to first melt-knead the ultraviolet-absorbing polymer and wax to produce a dispersion, and then melt-knead this together with the polyolefin to produce the masterbatch. Here, it is preferable to use a blend mixer or a three-roll mill to produce the dispersion.

Rather than blending an amount of the ultraviolet absorbing polymer equivalent to that contained in the molded body at the time of molding, if the ultraviolet absorbing polymer is first preliminarily dispersed as a master batch and then blended (melted and kneaded) with the thermoplastic resin of the diluent resin to produce a desired molded body, the ultraviolet absorbing polymer can be more easily dispersed uniformly in the molded body.
When the molding resin composition is prepared as a masterbatch, it is preferable to blend 1 to 30 parts by mass of the ultraviolet-absorbing polymer with 100 parts by mass of the polyolefin. The mass ratio of the masterbatch (x) to the diluent resin (y) is preferably x/y = 1/5 to 1/100. Within this range, the molded product is likely to have good optical properties.

The diluent resin is not limited to polyolefin, and any thermoplastic resin that is compatible with polyolefin may be appropriately selected and used.
The melt kneading is preferably carried out using, for example, a single screw kneading extruder, a twin screw kneading extruder, a tandem twin screw kneading extruder, etc. The melt kneading temperature varies depending on the type of polyolefin, but is usually about 150 to 250°C.

The molding resin composition of the present invention may contain, in addition to the polyolefin and ultraviolet-absorbing polymer, antioxidants, light stabilizers, dispersants, etc.

The molding resin composition of the present invention preferably contains an ultraviolet absorbing polymer and a thermoplastic resin other than polyolefin.
Examples of thermoplastic resins other than polyolefin include polycarbonate, polyacrylic, polyester, and cycloolefin resin.

<Polycarbonate>
Polycarbonate is a compound synthesized by a known method from a dihydric phenol and a carbonate precursor. Examples of dihydric phenols include hydroquinone, resorcinol, 2,2-bis(4-hydroxyphenyl)propane, bis(4-hydroxyphenyl)methane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane, and bis(4-hydroxyphenyl)sulfide. Among these, bis(4-hydroxyphenyl)alkanes are preferred, and 2,2-bis(4-hydroxyphenyl)propane, also known as bisphenol A, is more preferred.
Examples of carbonate precursors include phosgene, diphenyl carbonate, dihaloformates of dihydric phenols, etc. Among these, diphenyl carbonate is preferred.

The dihydric phenol and carbonate precursor can be used alone or in combination of two or more types.

<Polyacrylic>
Polyacrylic is a compound obtained by polymerizing monomers such as methyl methacrylate and/or ethyl methacrylate using a known method. Examples include ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-acrylic acid copolymer. In addition to the above-mentioned monomers, monomers such as butadiene, α-methylstyrene, and maleic anhydride can also be added for polymerization, and the heat resistance, fluidity, and impact resistance can be adjusted by adjusting the amount and molecular weight of the monomer.

<Polyester>
Polyesters are resins having ester bonds in the main chain of the molecule, and examples thereof include polycondensates synthesized from dicarboxylic acids (including their derivatives) and diols (dihydric alcohols or dihydric phenols); polycondensates synthesized from dicarboxylic acids (including their derivatives) and cyclic ether compounds; and ring-opening polymerization products of cyclic ether compounds. Examples of polyesters include homopolymers of dicarboxylic acids and diols, copolymers using multiple raw materials, and polymer blends of these. Dicarboxylic acid derivatives include acid anhydrides and esterified products. There are two types of dicarboxylic acids: aliphatic and aromatic. Aromatic dicarboxylic acids are preferred, as they have improved heat resistance.

Examples of aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, phthalic acid, chlorophthalic acid, nitrophthalic acid, p-carboxyphenylacetic acid, m-phenylenedigolic acid, p-phenylenedigolic acid, diphenyldiacetic acid, diphenyl-p,p'-dicarboxylic acid, diphenyl-4,4'-diacetic acid, diphenylmethane-p,p'-dicarboxylic acid, diphenylethane-m,m'-dicarboxylic acid, stilbenzylcarboxylic acid, diphenylbutane-p,p'-dicarboxylic acid, benzophenone-4,4'-dicarboxylic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, and naphthalene-2,7-dicarboxylic acid. Examples of the carboxylic acid include p-carboxyphenoxyacetic acid, p-carboxyphenoxybutyric acid, 1,2-diphenoxypropane-p,p'-dicarboxylic acid, 1,5-diphenoxypentane-p,p'-dicarboxylic acid, 1,6-diphenoxyhexane-p,p'-dicarboxylic acid, p-(p-carboxyphenoxy)benzoic acid, 1,2-bis(2-methoxyphenoxy)-ethane-p,p'-dicarboxylic acid, 1,3-bis(2-methoxyphenoxy)propane-p,p'-dicarboxylic acid, 1,4-bis(2-methoxyphenoxy)butane-p,p'-dicarboxylic acid, and 1,5-bis(2-methoxyphenoxy)-3-oxypentane-p,p'-dicarboxylic acid.
Examples of the aliphatic dicarboxylic acid include oxalic acid, succinic acid, adipic acid, suberic acid, magelaic acid, sebacic acid, dodecanedicarboxylic acid, undecanedicarboxylic acid, maleic acid, and fumaric acid.

Examples of dihydric alcohols include ethylene glycol, trimethylene glycol, butane-1,3-diol, butane-1,4-diol, 2,2-dimethylpropane-1,4-diol, cis-2-butene-1,4-diol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, octamethylene glycol, decamethylene glycol, cyclohexanedimethanol, etc. Among these, ethylene glycol, butane-1,4-diol, and cyclohexanedimethanol are preferred.
Examples of dihydric phenols include hydroquinone, resorcinol, and bisphenol A.
Examples of the cyclic ether compound include ethylene oxide and propylene oxide.

Dicarboxylic acids and dihydric alcohols can be used alone or in combination of two or more types.

<Cycloolefin resin>
Cycloolefin resins are polymers of ethylene or α-olefins and cyclic olefins. α-olefins are monomers derived from C4 to C12 α-olefins, such as 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, 1-decene, and 1-dodecene. Cycloolefins are monomers derived from norbornene, such as those substituted with a hydrogen group, a halogen atom, or a monovalent or divalent hydrocarbon group. Among these, unsubstituted norbornene is preferred.

When using a thermoplastic resin other than polyolefin, the UV-absorbing molding agent of the present invention is preferably made into a masterbatch, just as when using polyolefin. The masterbatch preparation method, optional ingredients, etc. are also the same as those described above.

The ultraviolet-absorbing molding agent of the present invention is preferably used for, for example, food packaging, pharmaceutical packaging, and display applications. For food packaging and pharmaceutical packaging, it is preferable to use, for example, polyester as the thermoplastic resin. These molded articles have improved flexibility and visibility, and can suppress deterioration of the contents.
Furthermore, for display applications (e.g., televisions, personal computers, smartphones, etc.), it is preferable to use, for example, polyacrylic or polycarbonate as the thermoplastic resin. These molded articles can suppress adverse effects on the eyes by absorbing ultraviolet light contained in backlights and light in the short wavelength region of visible light, and can also suppress deterioration of the display elements of displays by absorbing ultraviolet light contained in sunlight and light in the short wavelength region of visible light, and can also suppress a decrease in transparency due to migration.

The molded article of the present invention is produced by molding an ultraviolet absorbing molding agent.
Examples of the molding method include extrusion molding, injection molding, blow molding, etc. Examples of the extrusion molding method include compression molding, pipe extrusion molding, laminate molding, T-die molding, inflation molding, melt spinning, etc.

The molding temperature is usually between 160 and 240°C, depending on the softening point of the diluted resin.

In the present invention, a molded body is an article obtained by pouring an ultraviolet-absorbing molding agent into a mold. Furthermore, molded bodies include articles obtained without using a mold, such as plastic film, and molded bodies.

The molded article of the present invention can be used in a wide range of applications, including medical drugs, cosmetics, food containers and packaging materials, miscellaneous goods, textile products, pharmaceutical containers, various industrial coating materials, automobile parts, home appliances, building materials for housing, and toiletries. It can also be used in a wide range of applications, including display materials, sensor materials, and optical control materials.

(UV absorbing coating agent)
The ultraviolet absorbing agent of the present invention can be used as an ultraviolet absorbing coating agent. The ultraviolet absorbing coating agent may be used alone or may be mixed to form a coating composition.
Specifically, the ultraviolet-absorbing coating agent is an adhesive or pressure-sensitive adhesive for coating a pressure-sensitive adhesive layer or adhesive layer on a substrate as an adhesive sheet or adhesive sheet, or a paint for coating a coating layer on a substrate.
The pressure-sensitive adhesive preferably contains the ultraviolet-absorbing polymer of the present invention and a curing agent.
The ultraviolet absorbing polymer is a polymer synthesized by radical polymerization of an ultraviolet absorbing unsaturated monomer, a (meth)acrylic acid ester, an acidic group-containing monomer and/or a hydroxyl group-containing monomer, and the like.
Examples of the acidic group-containing monomer include acrylic acid and methacrylic acid.
Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate.

Examples of curing agents include isocyanate curing agents, epoxy curing agents, aziridine curing agents, and metal chelate curing agents.

For example, the adhesive can be coated onto a release sheet and dried to form an adhesive layer, and then a substrate can be attached to the adhesive layer to produce an adhesive sheet.

The pressure-sensitive adhesive sheet is preferably used by being attached to a display when used for a display (for example, a television, a personal computer, a smartphone, etc.).
By including the ultraviolet-absorbing material of the present invention, the pressure-sensitive adhesive sheet can absorb ultraviolet light contained in backlights and light in the short wavelength region of visible light, thereby suppressing adverse effects on the eyes. Furthermore, by absorbing ultraviolet light contained in sunlight and light in the short wavelength region of visible light, deterioration of display elements can be suppressed, and a decrease in transparency due to migration can also be suppressed. Note that the terms sheet, film, and tape are synonyms.

The coating agent, which is a paint, preferably contains a monomeric UV absorber or UV-absorbing polymer and other resins, and preferably also contains an organic solvent. The other resins preferably have a glass transition temperature of 30°C or higher. Examples include nitrocellulose and polyester. Thermosetting resins can also be used in paint applications. In this case, it is preferable for the resin to contain a curing agent. Thermosetting resins are resins with a glass transition temperature of 10°C or higher. Examples of thermosetting resins include acrylic resins, polyesters, and polyurethanes. Thermosetting resins preferably have functional groups that can react with the curing agent. Examples of such functional groups include carboxyl groups and hydroxyl groups. Examples of curing agents include isocyanate curing agents, epoxy curing agents, aziridine curing agents, and amine curing agents.

When the ultraviolet absorber of the present invention is used as a coating layer in paint, the ultraviolet-absorbing coating agent preferably has photocurability. Therefore, it preferably contains a photopolymerizable compound and a photopolymerization initiator. Furthermore, it is more preferable that the ultraviolet absorber in the ultraviolet-absorbing coating agent contains a photocurable moiety. The ultraviolet-absorbing coating agent is preferably used as a hard coat layer, a top coat layer, or an intermediate layer of various laminates. It can also contain known additives and, if necessary, an organic solvent.

Photopolymerizable compounds include monomers and oligomers. Examples of the photopolymerizable compound include methyl (meth)acrylate, ethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, cyclohexyl (meth)acrylate, β-carboxyethyl (meth)acrylate, polyethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, triethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, phenoxytetraethylene glycol (meth)acrylate, phenoxyhexaethylene glycol (meth)acrylate, trimethylolpropane PO-modified tri(meth)acrylate, trimethylolpropane EO-modified tri(meth)acrylate, isocyanuric acid EO-modified di(meth)acrylate, isocyanuric acid EO-modified tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol, Examples of suitable acrylic acid esters and methacrylic acid esters include butyl ether tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, 1,6-hexanediol diglycidyl ether di(meth)acrylate, bisphenol A diglycidyl ether di(meth)acrylate, neopentyl glycol diglycidyl ether di(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, tricyclodecanyl (meth)acrylate, ester acrylates, (meth)acrylic acid esters of methylolated melamine, epoxy (meth)acrylates, and urethane acrylates; (meth)acrylic acid, styrene, vinyl acetate, hydroxyethyl vinyl ether, ethylene glycol divinyl ether, pentaerythritol trivinyl ether, (meth)acrylamide, N-hydroxymethyl (meth)acrylamide, N-vinylformamide, and acrylonitrile.

Examples of photopolymerization initiators include acetophenone-based compounds, benzoin-based compounds, benzophenone-based compounds, thioxanthone-based compounds, triazine-based compounds, oxime ester-based compounds, phosphine-based compounds, quinone-based compounds, borate-based compounds, carbazole-based compounds, imidazole-based compounds, and titanocene-based compounds. Of these, oxime ester-based compounds are preferred due to their high sensitivity.

The UV-absorbing coating agent of the present invention can be used in a wide range of applications, such as as a coating layer for medical drugs, cosmetics, food containers and packaging materials, miscellaneous goods, textile products, pharmaceutical containers, various industrial coating materials, automotive parts, home appliances, building materials for housing, and toiletries. It can also be used in a wide range of applications, such as glass interlayer materials, lens materials, display materials, sensor materials, and optical control materials.

The present invention will be described in more detail below. The present invention is not limited to the examples. Note that "parts by mass" is expressed as "parts" and "% by mass" is expressed as "%".

(molecular weight)
The number average molecular weight (Mn) and weight average molecular weight (Mw) were measured by gel permeation chromatography (GPC) equipped with an RI detector. The instrument used was an HLC-8320GPC (manufactured by Tosoh Corporation), with two separation columns connected in series, and both columns packed with "TSK-GEL SUPER HZM-N" in series. The oven temperature was 40°C, and the eluent was a THF solution, with a flow rate of 0.35 ml/min. The sample was dissolved in a solvent consisting of 1 wt% of the above eluent, and 20 microliters was injected. All molecular weights are polystyrene equivalent values.

(Non-volatile content)
The nonvolatile content was measured by weighing 0.5 g of a sample into an aluminum container and heating it in an electric oven at 200°C for 1 hour.
The weight ratio was calculated from the weight ratio before and after drying after 0 minutes.
Nonvolatile content % = (weight after drying) / (weight before drying) x 100

<Example of Monomeric UV Absorber>
Example 1
[Ultraviolet absorber (A-1)]
A four-neck flask equipped with a thermometer, a stirrer, and a condenser was charged with 44.0 parts of 2-chloro-4,6-diphenyl-1,3,5-triazine, 87.7 parts of aluminum chloride, and 660 parts of chlorobenzene, and the mixture was stirred at room temperature to dissolve. Next, 49.9 parts of methyl 6-hydroxy-2-naphthoate was added little by little, and the mixture was heated to 90°C and stirred for 2 hours. After completion of the reaction, 2000 parts of methanol and 500 parts of water were charged into a separately prepared beaker, and the reaction solution was added dropwise. The precipitate was separated by filtration, and the resulting wet cake was returned to 1000 parts of methanol and reslurried at room temperature for 1 hour, followed by filtration. The resulting wet cake was dried overnight at 80°C to obtain 62.8 parts of a methyl ester intermediate.
Next, 62.8 parts of the methyl ester intermediate, 630 parts of methanol, 314 parts of a 25% aqueous sodium hydroxide solution, and 314 parts of water were charged into a four-neck flask equipped with a thermometer, a stirrer, and a condenser, and the mixture was heated to 60°C and stirred for 3 hours. After completion of the reaction, 1000 parts of 15% hydrochloric acid was charged into a separately prepared beaker, and the reaction solution was added dropwise. The precipitate was separated by filtration, and the resulting wet cake was reslurried in 1000 parts of water for 1 hour and separated by filtration. The resulting wet cake was dried overnight at 80°C to obtain 59.1 parts of a carboxylic acid intermediate.
Subsequently, a thermometer, a stirrer, and a four-necked flask equipped with a condenser were charged with 59.1 parts of a carboxylic acid intermediate, 40.1 parts of glycidyl methacrylate, 1.9 parts of N,N-dimethylbenzylamine, 0.06 parts of methylhydroquinone, and 590 parts of N-methyl-2-pyrrolidone, and heated to 100 ° C. under an air atmosphere and stirred for 4 hours. After completion of the reaction, a separately prepared beaker was charged with 600 parts of methanol, 300 parts of water, and 300 parts of 35% hydrochloric acid, and the reaction solution was added dropwise. The precipitate was filtered off, and the resulting wet cake was returned to 1000 parts of methanol and reslurried at room temperature for 1 hour, followed by filtration. The resulting wet cake was dried under reduced pressure at 60 ° C. overnight, yielding 63.3 parts of ultraviolet absorber (A-1).

The NMR measurement of the ultraviolet absorber (A-1) confirmed the above structure. The measurement conditions were as follows:
<Measurement conditions>
Equipment: BRUKER AVANCE400
Resonance frequency: 400MHz ( ^1H -NMR)
Solvent: dimethyl sulfoxide- _d6
Tetramethylsilane was used as the internal standard substance for ¹ H-NMR, and chemical shift values were expressed in δ values (ppm), and coupling constants in Hertz. Furthermore, s stands for singlet, d for doublet, dd for doubledouble, t for triplet, m for multiplet, and br for broad. The details of the obtained NMR spectrum are as follows:
δ=1.90 (s, 3H, -CH ₃ ), 4.16 (m, 1H, -CH-OH), 4.24 (m, 2H, -O-CH ₂ -), 4.34 (m, 2H, -O-CH ₂ -), 5.50 (br, 1H, -CH-OH), 5.70 (d, J=1.6Hz, 1H, C=CH ₂ ), 6.10 (d, J=1.6Hz, 1H, C=CH ₂ ), 7.40 (d, J=9.0Hz, 1H, naphthalene ring-H), 7.67 (t, J=7.3Hz, 4H, benzene ring-H), 7.70-7.80 (m, 2H, benzene ring-H), 7.70-7.80 (m, 1H, naphthalene ring-H), 8.03 (dd, J=9.2, 2.0Hz, 1H, naphthalene ring-H), 8.24 (d, J=9.0Hz, 1H, naphthalene ring-H), 8.62 (d, J=7.3Hz, 4H, benzene ring-H), 8.64 (d, J=2.0Hz, 1H, naphthalene ring-H), 12.00-13.00 (br, 1H, naphthalene ring-OH)

As mentioned above, in this specification, structural identification was performed using NMR using UV absorber (A-1) as an example. Structural identification was also performed using NMR for other UV absorbers in the same manner as above, but the data is omitted.

Example 2
[Ultraviolet absorber (A-2)]
An ultraviolet absorber (A-2) was obtained in the same manner as in Example 1, except that methyl 6-hydroxy-1-naphthoate was used instead of methyl 6-hydroxy-2-naphthoate.

Example 3
[Ultraviolet absorber (A-3)]
An ultraviolet absorber (A-3) was obtained in the same manner as in Example 1, except that methyl 7-hydroxy-2-naphthoate was used instead of methyl 6-hydroxy-2-naphthoate.

Example 4
[Ultraviolet absorber (A-4)]
An ultraviolet absorber (A-4) was obtained in the same manner as in Example 1, except that methyl 3-hydroxy-2-naphthoate was used instead of methyl 6-hydroxy-2-naphthoate.

Example 5
[Ultraviolet absorber (A-5)]
A four-neck flask equipped with a thermometer, a stirrer, and a condenser was charged with 20.0 parts of the carboxylic acid intermediate of Example 1, 0.3 parts of N,N-dimethylformamide, and 200 parts of chlorobenzene, and the mixture was stirred while cooling. Next, 11.4 parts of thionyl chloride was added dropwise at 0°C, and the mixture was stirred at 60°C for 2 hours. Next, 9.3 parts of 2-hydroxyethyl methacrylate and 9.7 parts of triethylamine were added dropwise, and the mixture was stirred at 60°C for 6 hours. After completion of the reaction, 300 parts of 10% hydrochloric acid was charged into a separately prepared beaker, and the previous reaction solution was added dropwise. The precipitate was separated by filtration, and the resulting wet cake was returned to 300 parts of methanol and reslurried at room temperature for 1 hour, followed by filtration. The resulting wet cake was dried under reduced pressure at 60°C overnight, yielding 20.3 parts of ultraviolet absorber (A-5).

Example 6
[Ultraviolet absorber (A-6)]
An ultraviolet absorber (A-6) was obtained in the same manner as in Example 5, except that 2-aminoethyl methacrylate was used instead of 2-hydroxyethyl methacrylate.

Example 7
[Ultraviolet absorber (A-7)]
An ultraviolet absorber (A-7) was obtained in the same manner as in Example 5, except that allyl alcohol was used instead of 2-hydroxyethyl methacrylate.

(Example 8)
[Ultraviolet absorber (A-8)]
A four-necked flask equipped with a thermometer, a stirrer, and a condenser was charged with 20.0 parts of ultraviolet absorber (A-1), 0.05 parts of dioctyltin dilaurate, 0.0006 parts of dibutylhydroxytoluene, and 200 parts of chlorobenzene, and the mixture was stirred at room temperature. Next, the reaction solution was heated to 70 ° C., and 5.5 parts of 2-isocyanatoethyl methacrylate was added dropwise little by little, followed by stirring for 5 hours. After completion of the reaction, 300 parts of water was added to a separately prepared beaker, and the previous reaction solution was added dropwise. The precipitate was filtered off, and the resulting wet cake was returned to 300 parts of methanol, reslurried at room temperature for 1 hour, and filtered off. The resulting wet cake was dried under reduced pressure at 60 ° C. overnight, and 22.9 parts of ultraviolet absorber (A-8) was obtained.

Example 9
[Ultraviolet absorber (A-9)]
An ultraviolet absorber (A-9) was obtained in the same manner as in Example 5, except that glycerol dimethacrylate was used instead of 2-hydroxyethyl methacrylate.

Example 10
[Ultraviolet absorber (A-10)]
An ultraviolet absorber (A-10) was obtained in the same manner as in Example 5, except that pentaerythritol triacrylate was used instead of 2-hydroxyethyl methacrylate.

Example 11
[Ultraviolet absorber (A-11)]
An ultraviolet absorber (A-11) was obtained in the same manner as in Example 1, except that cyanuric chloride was used instead of 2-chloro-4,6-diphenyl-1,3,5-triazine.

(Comparative Example 1)
[Ultraviolet absorber (A-12)]
The known compound 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-[2-(2-ethylhexanoyloxy)ethoxy]phenol was used as is for the evaluation.

(Comparative Example 2)
[Ultraviolet absorber (A-13)]

The above intermediate was synthesized using cyanuric chloride, 2-methylresorcinol, and 1-bromohexane as raw materials in accordance with the synthesis methods described in Examples of JP-A-11-71356 and JP-A-2018-504479.
Subsequently, 20.0 parts of the above intermediate and 100 parts of tetrahydrofuran were charged into a four-necked flask equipped with a thermometer, a stirrer, and a condenser, and the mixture was stirred at room temperature. Thereafter, 5.7 parts of acryloyl chloride was added dropwise little by little. Thereafter, 8.6 parts of triethylamine was added dropwise little by little, and the mixture was stirred at room temperature for 1 hour. Meanwhile, 300 parts of water was charged into a beaker, and the previous reaction solution was added dropwise, heated and stirred to volatilize tetrahydrofuran until an ultraviolet absorber precipitated, and then filtered. The obtained wet cake was returned to 300 parts of water, and reslurried at room temperature for 1 hour, and then filtered. The obtained wet cake was dried under reduced pressure at 60 ° C., and the following ultraviolet absorber (A-13) was obtained.

(A-13)

[Heat resistance]
The results of evaluation of the ultraviolet absorbents of Examples 1 to 11 and the ultraviolet absorbents of Comparative Examples 1 and 2 using a thermogravimetric differential thermal analyzer are shown in Table 1. The measurement conditions are as follows:
<Measurement conditions>
Apparatus: TG-DTA8122 (manufactured by RIGAKU Corporation)
Measurement atmosphere: nitrogen Temperature rise condition: 10°C/min
Measurement range: 40 to 500°C

The evaluation criteria for heat resistance are as follows.
◯: 50% weight loss temperature is 420°C or higher △: 50% weight loss temperature is 370°C or higher but less than 420°C X: 50% weight loss temperature is less than 370°C. Not suitable for practical use

[Light absorption]
The ultraviolet-visible absorption spectra of the ultraviolet absorbents of Examples 1 to 11 and Comparative Examples 1 and 2 were measured, and the results are shown in Table 1. The method for preparing the measurement container and the measurement conditions are as follows. Note that for all of these ultraviolet absorbents, the visible light absorbency and the like were evaluated after confirming that the transmittance was less than 10% in the wavelength range of 320 nm or more and less than 400 nm.

<Solution preparation method>
One part of the ultraviolet absorber and 1,000 parts of chloroform were mixed and completely dissolved, and then one part of the above solution and 99 parts of chloroform were uniformly mixed to prepare a measurement solution with a concentration of 10 ppm.

<Measurement conditions>
Apparatus: U-3500 (manufactured by Hitachi, Ltd.)
Measurement wavelength: 260-700nm

The evaluation criteria for the ultraviolet-visible absorption spectrum are as follows:
Good: Absorbs light in the visible light region of 400 to 420 nm, with a maximum absorption wavelength of 360 nm or more in the 340 to 420 nm region. Bad: Absorbs only light in the ultraviolet region of less than 400 nm. Not suitable for practical use.

[purity]
Purity was evaluated by high-performance liquid chromatography equipped with a UV detector. An ACQUITY UPLC H-Class (Waters) was used as the instrument, and an ACQUITY UPLC BEH C18 was used as the column. Gradient measurements were performed at a temperature of 40°C, using 50 mM aqueous ammonium acetate and DMF as the eluent, and a flow rate of 0.4 ml/min. The measurement sample was dissolved in DMF and 1 μL was injected.

The purity evaluation criteria are as follows:
◯: No peak of excess reactant, purity is 95% or more △: No peak of excess reactant, purity is 85% or more but less than 95% X: Excess reactant peak present. Not suitable for practical use Incidentally, excess reactant means a product in which the reaction has proceeded excessively and the ultraviolet absorber has been polysubstituted with polymerizable moieties.

[Colorability]
The color of the obtained ultraviolet absorber was visually evaluated according to the following criteria.
◯: Light yellow. Good △: Yellow. Practical range ×: Deep yellow. Not practical.

<Example of UV-absorbing polymer>
Example 12
[Ultraviolet-absorbing polymer (B-1)]
A four-neck separable flask equipped with a thermometer, a stirrer, a condenser, and a dropping funnel was charged with 40.0 parts of ultraviolet absorber (A-1), 0.4 parts of 2-ethylhexyl thioglycolate, and 56.9 parts of cyclohexanone, and the temperature was raised to 100°C under a nitrogen stream. Separately, 0.4 parts of 2,2'-azobis(dimethyl isobutyrate) and 2.3 parts of cyclohexanone were mixed and completely dissolved to prepare a polymerization initiator solution, which was then charged into the dropping funnel. The polymerization initiator solution was added dropwise over 6 hours, and a polymerization reaction was carried out. Two hours after the completion of the dropwise addition, it was confirmed from the solid content that the conversion rate was 98% or higher, and the polymerization reaction was terminated by cooling. The obtained ultraviolet absorbing polymer (B-1) had a nonvolatile content of 40.8%, a weight average molecular weight (Mw) of 30,000, a number average molecular weight (Mn) of 15,000, and a molecular weight distribution (Mw/Mn) of 2.00.

The ultraviolet-absorbing polymers of Examples 13 to 27 and Comparative Examples 3 and 4 were produced using the polymerization compositions shown in Table 2 in the same manner as in Example 12. Note that the ultraviolet-absorbing polymer (B-17) of Comparative Example 3 gelled during polymerization.

[Heat resistance]
The results of evaluation of the ultraviolet absorbing polymers of Examples 12 to 27 and Comparative Example 4 using a thermogravimetric differential thermal analyzer are shown in Table 2. The measurement conditions are as follows:
<Measurement conditions>
Apparatus: TG-DTA8122 (manufactured by RIGAKU Corporation)
Measurement atmosphere: nitrogen Temperature rise condition: 10°C/min
Measurement range: 40 to 500°C

The evaluation criteria for heat resistance are as follows.
◯: 50% weight loss temperature is 360°C or higher. ×: 50% weight loss temperature is less than 360°C. Not practical.

[Light absorption]
The ultraviolet-visible absorption spectra of the ultraviolet-absorbing polymers of Examples 12 to 27 and Comparative Example 4 were measured, and the results are shown in Table 2. The method for preparing the measurement container and the measurement conditions are as follows. Note that these ultraviolet-absorbing polymers were all confirmed to have a transmittance of less than 10% in the wavelength range of 320 nm or more and less than 400 nm, and then their visible light absorbance and other properties were evaluated.

<Solution preparation method>
One part of the ultraviolet absorber and 1,000 parts of chloroform were mixed and completely dissolved, followed by uniformly mixing 5 parts of the above solution and 95 parts of chloroform to prepare a measurement solution with a concentration of 10 ppm.

<Measurement conditions>
Apparatus: U-3500 (manufactured by Hitachi, Ltd.)
Measurement wavelength: 260-700nm

The evaluation criteria for the ultraviolet-visible absorption spectrum are as follows:
◯: Absorbs light in the visible light region of 400 to 420 nm, with the maximum absorption wavelength in the 340 to 420 nm region being 360 nm or more. ×: Absorbs only light in the ultraviolet region of less than 400 nm.

The abbreviations used in Table 2 are as follows:
MMA: methyl methacrylate LA: lauryl acrylate ISTA: isostearyl acrylate CHMA: cyclohexyl methacrylate DCPMA: dicyclopentanyl methacrylate BzMA: benzyl methacrylate MAnh: maleic anhydride AA: acrylic acid HEMA: 2-hydroxyethyl methacrylate Comparative monomer: 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole

(Example 28)
<Masterbatch manufacturing>
100 parts of wax (C-1) and 100 parts of the dried product of ultraviolet-absorbing polymer (B-1) were mixed and kneaded at 160 ° C. using a three-roll mill to obtain a dispersion of ultraviolet-absorbing polymer (B-1). Next, 12.2 parts of the dispersion obtained above together with 97.8 parts of polyolefin (D-1) were mixed in a Henschel mixer. Next, the mixture was melt-kneaded at 180 ° C. using a single-screw extruder with a screw diameter of 30 mm, and then cut into pellets using a pelletizer to obtain a masterbatch. The dried product of the ultraviolet-absorbing polymer was obtained by reprecipitation purification using a known method and vacuum drying at 60 ° C. for 24 hours.
<Film molding>
100 parts of polyolefin (D-1) was mixed with 10 parts of the resulting masterbatch as a diluent resin, and then the mixture was melt-mixed and molded at 180°C using a T-die molding machine (manufactured by Toyo Seiki Seisaku-sho) to obtain a film having a thickness of 1 mm.

(Examples 29 to 43, Comparative Example 5)
Masterbatches were produced in the same manner as in Example 28, except that the materials in Example 28 were changed to the materials and blending amounts shown in Table 3, and then films of Examples 29 to 43 and Comparative Example 5 were produced, respectively. The blending amounts of the ultraviolet-absorbing polymer and diluent resin in the masterbatch were adjusted so that the ultraviolet absorber concentration (UVA concentration) in the film would be the same as in Example 28.

(Example 44)
<Production of master batches, which are UV-absorbing molding agents>
100 parts of polycarbonate (E-1) and 20 parts of the dried product of ultraviolet absorbing polymer (B-8) were fed into a twin-screw extruder (manufactured by The Japan Steel Works, Ltd.) having a screw diameter of 30 mm through the same supply port, melt-kneaded at 280°C, and then cut into pellets using a pelletizer to prepare a masterbatch. The dried product of the ultraviolet absorbing polymer was obtained by reprecipitation purification using a known method and vacuum drying at 60°C for 24 hours.
<Film molding>
6.6 parts of the obtained master batch was mixed with 103.4 parts of the dilution resin polycarbonate (E-1), and the mixture was melt-mixed at a temperature of 280°C using a T-die molding machine (manufactured by Toyo Seiki Seisaku-sho) to form a film having a thickness of 1 mm.

(Examples 45 to 47, Comparative Examples 6 to 9)
Masterbatches were produced in the same manner as in Example 44, except that the materials in Example 44 were changed to the materials shown in Table 4, and then films of Examples 45 to 47 and Comparative Examples 6 to 9 were produced. The amounts of the ultraviolet-absorbing polymer and diluent resin in the masterbatch were adjusted so that the ultraviolet absorber concentration (UVA concentration) in the film was the same as in Example 44.

[Optical properties]
The transmittance of the obtained film was measured using an ultraviolet-visible-near infrared spectrophotometer (manufactured by Shimadzu Corporation) as a spectral transmittance measured against a white standard plate.
The evaluation was carried out to see if the following conditions were met.
◯: Light transmittance of wavelengths from 380 to 400 nm is less than 2% across the entire region. ×: Light transmittance of wavelengths from 380 to 400 nm is 2% or more across the entire region. Not suitable for practical use.

[Transparency]
The transmittance of the obtained film was evaluated visually according to the following criteria.
◎: No turbidity at all. Very good. ◯: Almost no turbidity. Good. △: Slight turbidity. Practical range. ×: Clear turbidity. Not practical.

[Quality over time]
The obtained film was exposed to a xenon weather meter at an illuminance of 60 W/m ² at 300 to 400 nm for 1500 hours.
◯: No yellowing observed at all.
△: Slight yellowing is observed.
×: Yellowing is clearly observed. Unsuitable for practical use.

[Migration evaluation]
The obtained film was sandwiched between soft vinyl chloride sheets and heat-pressed using a heat press under conditions of a pressure of 100 g/ ^cm2 and a temperature of 170°C for 30 seconds. The film was then immediately removed, and migration into the soft vinyl chloride sheet was evaluated using an ultraviolet-visible-near infrared spectrophotometer (manufactured by Shimadzu Corporation). The evaluation was performed by selecting five locations on the soft vinyl chloride sheet that had been treated as described above, measuring the absorbance in the ultraviolet region, and calculating the average.
◯: absorbance less than 0.05 at less than 400 nm and at 400 to 420 nm △: absorbance of 0.05 or more and less than 0.2 at less than 400 nm and at 400 to 420 nm ×: absorbance of 0.2 or more at less than 400 nm and at 400 to 420 nm. Not suitable for practical use.

[Change in light absorption over time due to heat]
The resulting film was evaluated for changes in light absorption with time due to heat.
<Evaluation method>
The obtained film was placed in an oven with an internal temperature of 80° C. for one week, and then the change in the shape of the ultraviolet-visible absorption spectrum was evaluated. The evaluation criteria were as follows:
◯: No change in the spectrum shape is observed before and after applying heat history. ×: The spectrum shape changes before and after applying heat history. Not practical.

The waxes used in the examples are listed below.
(C-1) Polyethylene wax (SANWAX 131-P, average molecular weight 3500, melting point 105°C, manufactured by Sanyo Chemical Industries, Ltd.)

The polyolefins (number average molecular weight of 30,000 or more) used in the examples are shown below.
(D-1) Polyethylene (Suntec LD M2270, MFR = 7 g/10 min, manufactured by Asahi Kasei Chemicals Corporation)

Furthermore, thermoplastic resins other than polyolefins used in the examples are listed below.
(E-1) Polycarbonate (Iupilon S3000, MFR = 15 g/10 min, manufactured by Mitsubishi Engineering-Plastics Corporation)
(E-2) Polymethacrylic resin (Acrypet MF, MFR = 14 g/10 min, manufactured by Mitsubishi Rayon Co., Ltd.)
(E-3) Polyester (Mitsui Pet SA135, manufactured by Mitsui Chemicals)
(E-4) Cycloolefin resin (TOPAS5013L-10, manufactured by Mitsui Chemicals, Inc.)

(Adhesive Resin Production Example F-1)
Using a reactor equipped with a stirrer, reflux condenser, nitrogen inlet tube, thermometer, and dropping tube, 96.0 parts of n-butyl acrylate, 4.0 parts of 2-hydroxyethyl acrylate, 50% of the total amount, 0.2 parts of 2,2'-azobisisobutylnitrile as a polymerization initiator, and 150 parts of ethyl acetate as a solvent were charged into a reaction vessel under a nitrogen atmosphere, and the remaining 50% of the total amount and an appropriate amount of ethyl acetate were charged into a dropping vessel. Next, heating was started and the start of the reaction in the reaction vessel was confirmed, and then the contents of the dropping tube and 0.01 parts of an ethyl acetate diluted solution of 2,2'-azobisisobutylnitrile were added dropwise under reflux. After completion of the dropping, the reaction was allowed to proceed for 5 hours while maintaining the reflux state. After completion of the reaction, the mixture was cooled and an appropriate amount of ethyl acetate was added to obtain Adhesive Resin Production Example F-1, an acrylic resin. The adhesive resin of Production Example F-1 thus obtained had a weight average molecular weight of 500,000, a nonvolatile content of 40%, and a viscosity of 3,200 mPa·s.

(Example 50)
As an adhesive resin, 100 parts of the nonvolatile content of the adhesive resin of Production Example F-1 was mixed with 2 parts of ultraviolet absorbing polymer (B-1), 0.1 parts of KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd.) as a silane coupling agent, and 0.4 parts of a trimethylolpropane adduct of tolylene diisocyanate (abbreviation: TDI-TMP, NCO value = 13.2, nonvolatile content = 75%) as a curing agent (D) were added, and the mixture was stirred well to obtain an adhesive. Thereafter, this adhesive was applied to a release film of a 38 μm thick polyethylene terephthalate substrate so that the thickness after drying was 50 μm, and dried for 2 minutes in a hot air oven at 100 ° C. Then, a 25 μm polyethylene terephthalate film was bonded to the adhesive layer side, and the mixture was aged at room temperature for 7 days in this state to obtain an adhesive sheet.

(Examples 51 to 65, Comparative Example 10)
As shown in Table 5, pressure-sensitive adhesive sheets of Examples 51 to 65 and Comparative Example 10 were obtained in the same manner as in Example 50. The amount of ultraviolet-absorbing polymer was adjusted so that the ultraviolet absorber concentration (UVA concentration) in the dried coating film was the same as in Example 50.

(Evaluation of adhesive sheets)
[Adhesive strength]
The resulting pressure-sensitive adhesive sheet was prepared to a size of 25 mm wide and 150 mm long. In an atmosphere of 23°C and 50% relative humidity, the release film was peeled off from the pressure-sensitive adhesive sheet, and the exposed pressure-sensitive adhesive layer was attached to a glass plate and pressed back and forth once with a 2 kg roll. After leaving it for 24 hours, the adhesive strength was measured using a tensile tester in a 180° peel test, in which the sheet was peeled in a 180° direction at a rate of 300 mm/min, and evaluated based on the following evaluation criteria (in accordance with JIS Z0237:2000).
⊚: Adhesion strength is 15 N or more, which is very good.
○: Adhesion strength is 10 N or more and less than 15 N, which is good.
×: Adhesive strength is less than 10 N, and not practical.

[Holding power]
The obtained adhesive sheet was prepared in a size of 25 mm wide x 150 mm long. According to JIS Z0237:2000, the release sheet was peeled off from the adhesive sheet, and the adhesive layer was attached to a 25 mm wide x 25 mm wide portion of the lower end of a polished stainless steel plate with a width of 30 mm and a length of 150 mm. After one round trip of pressure bonding with a 2 kg roll, a load of 1 kg was applied in a 40 ° C atmosphere and left for 70,000 seconds to measure the holding power. For evaluation, the length of downward shift of the upper end of the adhesive sheet attachment surface was measured.
Evaluation criteria: Good: The shifted length is less than 0.5 mm.
×: The shifted length is 0.5 mm or more. Not practical.

[Transparency]
The release sheet was peeled off from the obtained pressure-sensitive adhesive sheet, and the transparency of the pressure-sensitive adhesive layer was evaluated visually. The appearance of the pressure-sensitive adhesive layer was evaluated based on the following three-level evaluation criteria.
○: The adhesive layer is transparent and good. △: The adhesive layer is slightly whitened, but is within the range of practical use. ×: The adhesive layer is whitened and is not suitable for practical use.

[Migration evaluation]
The resulting adhesive sheet was prepared in a size of 100 mm wide and 100 mm long. Under an atmosphere of 23 ° C and 50% relative humidity, the release film was peeled off from the adhesive sheet, and the exposed adhesive layer was attached to a glass plate and pressed back and forth once with a 2 kg roll. The sheet was then left in the same environment for 48 hours, and the adhesive sheet was then peeled off. The migration of the ultraviolet-absorbing material into the glass was evaluated using a UV-visible-near-infrared spectrophotometer (manufactured by Shimadzu Corporation). The evaluation was performed by selecting five locations on the glass that had been treated as described above, measuring the absorbance in the ultraviolet region, and calculating the average.
◯: absorbance less than 0.05 at less than 400 nm and at 400 to 420 nm △: absorbance of 0.05 or more and less than 0.2 at less than 400 nm and at 400 to 420 nm ×: absorbance of 0.2 or more at less than 400 nm and at 400 to 420 nm. Not suitable for practical use.

[Change in light absorption over time due to heat]
The pressure-sensitive adhesive sheet was evaluated for its change in light absorption over time due to heat.
<Evaluation method>
The pressure-sensitive adhesive sheet was placed in an oven with an internal temperature of 80° C. for one week, and then the change in the shape of the ultraviolet-visible absorption spectrum was evaluated. The evaluation criteria were as follows:
◯: No change in the spectrum shape is observed before and after applying heat history. ×: The spectrum shape changes before and after applying heat history. Not practical.

<Paint>
(Example 66)
A paint was prepared by stirring and mixing the following composition.
Ultraviolet absorbing polymer (B-1) 1.0 part Polyester (Vylon GK250, manufactured by Toyobo Co., Ltd.) 9.0 parts Methyl ethyl ketone 90.0 parts

(Examples 67 to 81, Comparative Example 11)
As shown in Table 6, the paints of Examples 67 to 81 and Comparative Example 11 were prepared in the same manner as in Example 66. The amount of ultraviolet absorbing polymer was adjusted so that the ultraviolet absorber concentration (UVA concentration) in the dried coating film was the same as in Example 66.

(Production of coated material)
The resulting coating material was applied to a glass substrate having a thickness of 1000 μm using a bar coater so as to give a dry film thickness of 6 μm, and dried at 100° C. for 2 minutes to form a coating film.
(Evaluation of coated products)
The resulting coated products were evaluated by the following methods.

[Transparency Assessment]
The transparency of the obtained substrate was evaluated visually.
○: No turbidity observed. Good ×: Turbidity observed. Not suitable for practical use.

[Migration evaluation]
A soft vinyl chloride sheet was placed on the coating surface of the obtained coating product and heat-pressed using a heat press under conditions of a pressure of 100 g/ ^cm2 and a temperature of 170°C for 30 seconds. The film was then immediately removed, and migration to the soft vinyl chloride sheet was evaluated using an ultraviolet-visible-near-infrared spectrophotometer (manufactured by Shimadzu Corporation). Evaluation was performed by selecting five locations on the soft vinyl chloride sheet that had been treated as described above, measuring the absorbance in the ultraviolet region, and calculating the average.
◯: absorbance less than 0.05 at less than 400 nm and at 400 to 420 nm △: absorbance of 0.05 or more and less than 0.2 at less than 400 nm and at 400 to 420 nm ×: absorbance of 0.2 or more at less than 400 nm and at 400 to 420 nm. Not suitable for practical use.

[Change in light absorption over time due to heat]
The resulting coated products were evaluated for changes in light absorption with time due to heat.
<Evaluation method>
The resulting coated product was placed in an oven with an internal temperature of 80° C. for one week, and then the change in the shape of the ultraviolet-visible absorption spectrum was evaluated. The evaluation criteria were as follows:
◯: No change in the spectrum shape is observed before and after applying heat history. ×: The spectrum shape changes before and after applying heat history. Not practical.

<Photocurable composition>
(Example 82)
The raw materials were mixed and stirred to prepare a photocurable composition according to the following composition.
Ultraviolet absorber (A-1) 10.0 parts Photopolymerizable compound (multifunctional acrylate "KAYARAD DPHA" manufactured by Nippon Kayaku Co., Ltd.)
9.0 parts Photopolymerization initiator ("Omnirad 184" manufactured by IGM Resin BV) 1.0 part Propylene glycol monomethyl ether 80.0 parts

(Examples 83 to 88, Comparative Examples 12 to 13)
As shown in Table 7, the photocurable compositions of Examples 83 to 88 and Comparative Examples 12 to 13 were prepared in the same manner as in Example 82. The amount of ultraviolet absorber or ultraviolet-absorbing polymer was adjusted so that the ultraviolet absorber concentration (UVA concentration) in the dried coating film was the same as that of Example 82.

(Production of coated material)
The photocurable composition was applied to a 1 mm thick glass substrate using a bar coater to a dry film thickness of 6 μm. The resulting coating was dried at 100° C. for 1 minute and then cured by irradiating it with ultraviolet light from a high-pressure mercury lamp at 400 mJ/ ^cm2 to produce a coated product.
(Evaluation of coated products)
The resulting coated products were evaluated by the following methods.

[Scratch resistance]
The coated sample was placed in a Gakushin tester and shaken 10 times with steel wool at a load of 250 g. The coated sample was then removed and the degree of scratching was judged visually on a 5-point scale as follows. A higher score indicates better scratch resistance of the cured film.
5: No scratches at all.
4: There are slight scratches.
3: Scratches are present, but the substrate is not visible.
2: Scratches were observed and the cured film was partially peeled off.
1: The cured film peeled off, leaving the substrate exposed. Not suitable for practical use.

[Pencil hardness]
In accordance with JIS-K5600, a pencil hardness tester (HEIDON-14 Scratching Tester manufactured by HEIDON) was used to test five times with various pencil lead hardnesses at a load of 500 g on the cured film of the coating material. The hardness of the lead when no scratches were made or only one scratch was made out of the five times was taken as the pencil hardness of the cured film. The evaluation criteria were as follows:
A: 2H or more.
B:H.
C: Lower than H. Not practical.

[Transparency]
The transparency of the resulting coated product was evaluated visually.
○: No turbidity observed. Good △: Slight turbidity observed. Practical range ×: Significant turbidity observed. Not practical

[Migration evaluation]
The resulting coated product was sandwiched between two soft vinyl chloride sheets and heat-pressed using a heat press under conditions of a pressure of 100 g/ ^cm2 and a temperature of 170°C for 30 seconds. The film was then immediately removed, and migration into the soft vinyl chloride sheet was evaluated using an ultraviolet-visible-near-infrared spectrophotometer (manufactured by Shimadzu Corporation). Evaluation was performed by selecting five locations on the soft vinyl chloride sheet that had been treated as described above, measuring the absorbance in the ultraviolet region, and calculating the average.
◯: absorbance less than 0.05 at less than 400 nm and at 400 to 420 nm △: absorbance of 0.05 or more and less than 0.2 at less than 400 nm and at 400 to 420 nm ×: absorbance of 0.2 or more at less than 400 nm and at 400 to 420 nm. Not suitable for practical use.

[Change in light absorption over time due to heat]
The resulting coated products were evaluated for changes in light absorption with time due to heat.
<Evaluation method>
The resulting coated product was placed in an oven with an internal temperature of 80° C. for one week, and then the change in the shape of the ultraviolet-visible absorption spectrum was evaluated. The evaluation criteria were as follows:
◯: No change in the spectrum shape is observed before and after applying heat history. ×: The spectrum shape changes before and after applying heat history. Not practical.

As shown in Tables 1 to 7, it was found that the ultraviolet absorbers and ultraviolet absorbing polymers of the present invention absorb light in the ultraviolet region of less than 400 nm and in the visible short wavelength region of 400 to 420 nm, and are excellent in heat resistance, bleeding resistance, and low coloration.

Claims (6)

An ultraviolet absorber having a triazine ring directly bonded to a hydroxynaphthyl group, wherein the hydroxynaphthyl group is a group having a structure represented by the following general formula (1):
General formula (1) *-X-Y-Z
(In the formula, X represents —COO— or —CONH—, Y represents a divalent linking group, Z represents a polymerizable unsaturated group, and * represents a bond to the hydroxynaphthyl group.) The ultraviolet absorber according to claim 1, wherein the polymerizable unsaturated group is one selected from the group consisting of a vinyl group, a (meth)allyl group, and a (meth)acryloyl group. An ultraviolet absorber which is a polymer of the ultraviolet absorber according to claim 1 or 2. An ultraviolet absorber which is a copolymer of the ultraviolet absorber according to claim 1 or 2 with another monomer. An ultraviolet-absorbing molding agent comprising the ultraviolet absorber described in any one of claims 1 to 4. An ultraviolet absorbing coating agent, comprising the ultraviolet absorber according to any one of claims 1 to 4.