TW202028388A - Photocurable adhesive composition - Google Patents

Abstract

A photocurable adhesive composition comprising a group 8 transition metal metallocene compound and a 2-cyanoacrylate compound, and do not comprising a compound having a benzoquinone structure or comprising a compound having a benzoquinone structure and wherein the content of a compound having a benzoquinone structure is more than 0 ppm and less than 4 ppm.

Description

Light-curing adhesive composition

The invention relates to a light-curing adhesive composition.

The adhesive composition containing the 2-cyanoacrylate compound can quickly start to polymerize by the trace moisture existing near the surface of the material to be adhered, and in a very short time of a few seconds to a few minutes, it will be made of various materials. Almost all of the materials to be adhered are adhered, and its adhesive force is also strong, so it is used as the main component of instant adhesives in a wide range of fields such as electrical, electronic, mechanical parts, precision machinery, household goods, and medical.

In addition, a photocurable adhesive composition is known that can be easily cured by light without impairing the excellent characteristics of an instant adhesive such as a one-component type at room temperature. As the conventional photocurable adhesive composition, for example, the composition described in Patent Documents 1 to 4 is known. Patent Document 1 describes a photocurable composition characterized in that as essential components, it is composed of (A) α-cyanoacrylate and (B) group VIII of the periodic table containing an aromatic electron-based ligand. (Group 8) of transition metal metallocene (metallocene) compounds.

In addition, Patent Document 2 describes a photocurable composition characterized by containing the following components as essential components: (A) α-cyanoacrylate, (B) dicene substituted with a lower alkyl group Iron compound, and (C) light hardening accelerator.

In addition, Patent Document 3 describes a photocurable composition characterized in that, as essential components, (A) α-cyanoacrylate, (B) an aromatic electron-based ligand-containing periodic table The transition metal metallocene compound of group VIII, (C) is composed of a photohardening accelerator having a structure represented by the following general formula (1).

式(1)中，R為氫原子、或碳數1～8的烷基、鹵素基、碳數1～8的烷硫基，各R可相同或不同。

In the formula (1), R is a hydrogen atom, or an alkyl group having 1 to 8 carbons, a halogen group, or an alkylthio group having 1 to 8 carbons, and each R may be the same or different.

In addition, Patent Document 4 describes a cyanoacrylate-based adhesive composition that can be cured by moisture and light, and contains the following components as essential components: (A) α-cyanoacrylate, (B ) Multifunctional compounds with (meth)acrylic acid groups, (C) peroxides, (D) metallocene compounds of transition metals from group 8 of the periodic table containing aromatic electron-based ligands, (E) molecules Internal fracture type light radical initiator.

Patent Document 1: Japanese Patent Application Publication No. 9-249708 Patent Document 2: Japanese Patent Application Laid-Open No. 11-166006 Patent Document 3: Japanese Patent Application Publication No. 2003-277422 Patent Document 4: Japanese Patent Application Publication No. 2007-217484

[The problem to be solved by the invention] The problem to be solved by the present invention is to provide a light-curing adhesive composition which has excellent storage stability. [Technical means to solve the problem]

The technical means to solve the aforementioned problems include the following aspects. >1> A photocurable adhesive composition comprising: a group 8 transition metal metallocene compound and a 2-cyanoacrylate compound; and, it does not contain a compound having a quinone structure or has a quinone structure The content of the compound is more than 0 ppm and less than 4 ppm. >2> The photocurable adhesive composition as described in >1>, wherein the group 8 transition metal metallocene compound is at least selected from the group consisting of ferrocene and ruthenium 1 kind of compound. >3> The photocurable adhesive composition as described in >1> or >2>, wherein the aforementioned Group 8 transition metal metallocene compound is ferrocene. >4> The photocurable adhesive composition according to any one of >1> to >3>, which further contains a light radical generator. >5> The photocurable adhesive composition as described in >4>, wherein the photo-radical generator is composed of an acyl germane compound, an acyl phosphine oxide compound and an alkyl phenone compound At least one compound selected from the group. >6> The photocurable adhesive composition according to any one of >1> to >5>, which further contains a polymerization inhibitor. >7> The photocurable adhesive composition according to >6>, wherein the polymerization inhibitor includes a phenolic radical polymerization inhibitor. >8> The photocurable adhesive composition as described in >6> or >7>, wherein the polymerization inhibitor includes a radical polymerization inhibitor having a hydroquinone structure. >9> The photocurable adhesive composition as described in >7> or >8>, wherein the content of the polymerization inhibitor is 10 ppm or more and 1,000 ppm or less. [effect]

According to the present invention, it is possible to provide a photocurable adhesive composition having excellent storage stability.

The description of the constitutional requirements described below may be performed in accordance with a representative embodiment of the present invention, but the present invention is not limited to such an embodiment. In addition, in the specification of this case, the so-called "~" is used in the meaning of including the numerical value described before and after it as the lower limit and the upper limit. In the numerical ranges described in stages in this specification, the upper limit or lower limit described in one numerical range can be replaced with the upper limit or lower limit of another numerical range described in stages. In addition, in the numerical range described in this specification, the upper limit or the lower limit of the numerical range can be replaced with the values disclosed in the examples. In the present invention, when a plurality of substances corresponding to each component are present in the composition, the amount of each component in the composition means the total amount of the plurality of substances present in the composition unless otherwise specified. In the present invention, the term "step" is not only an independent step, but even if it cannot be clearly distinguished from other steps, as long as the desired purpose of the step can be achieved, it is also included in this term. In the present invention, "% by mass" and "% by weight" have the same meaning, and "parts by mass" and "parts by weight" have the same meaning. In addition, in the present invention, a combination of two or more preferable aspects is a more preferable aspect. In addition, in this specification, "(meth)acryloyl group" means both or either of an acryloyl group and a methacryloyl group, and "(meth)acryloyloxy group" means an acryloyloxy group and a methacryloyl group. Both or either of the acetoxy groups. In addition, in some of the compounds in this specification, a hydrocarbon chain may be described in a simplified structural formula with the symbols of carbon (C) and hydrogen (H) omitted. Hereinafter, the content of the present invention will be described in detail.

(Photocurable adhesive composition) The photocurable adhesive composition of the present invention contains: a group 8 transition metal metallocene compound and a 2-cyanoacrylate compound; and does not contain a compound having a benzoquinone structure or a compound having a benzoquinone structure The content is more than 0 ppm and less than 4 ppm.

In the conventional method for producing 2-cyanoacrylate compounds, when depolymerization is performed, a compound having a hydroquinone structure such as hydroquinone is often used as a polymerization inhibitor. However, the present inventors discovered the following fact: when a compound having a hydroquinone structure is used in the production of a 2-cyanoacrylate compound, the compound having a hydroquinone structure will be oxidized due to the action of impurities and decomposition products, although Trace amounts of compounds with benzoquinone structure are still produced; even if distillation is performed, the compounds with benzoquinone structure in the 2-cyanoacrylate compound cannot be completely removed; and the presence of compounds with benzoquinone structure will greatly increase Contributes to the storage stability of the photocurable adhesive composition. The inventors of the present invention have intensively studied and found that by making the following composition, it is possible to provide a photocurable adhesive composition with excellent storage stability. The composition is based on 2-cyanoacrylate photocuring In the adhesive composition, the content of the compound that does not contain a quinone structure or a compound that has a benzoquinone structure exceeds 0 ppm and does not reach 4 ppm.

Hereinafter, the present invention will be described in detail.

>Compounds with benzoquinone structure> The photocurable adhesive composition of the present invention does not contain a compound having a benzoquinone structure, or the content of a compound having a benzoquinone structure exceeds 0 ppm and does not reach 4 ppm. In addition, from the viewpoint of storage stability, the photocurable adhesive composition of the present invention preferably does not contain a compound having a quinone structure, or the content of a compound having a quinone structure exceeds 0 ppm and 3 ppm. Hereinafter, it is more preferable that the content of a compound having no benzoquinone structure or a compound having a benzoquinone structure is more than 0 ppm and 2 ppm or less, and it is even more preferable that it does not contain a compound having a benzoquinone structure or has a quinone structure The content of the compound is more than 0 ppm and less than 1.5 ppm. Furthermore, when the photocurable adhesive composition of the present invention contains two or more compounds having a quinone structure, the aforementioned content is the total content of two or more compounds having a quinone structure.

The compound having a benzoquinone structure in the present invention may be a compound having a 1,4-benzoquinone structure or a compound having a 1,2-benzoquinone structure. Examples of compounds having a benzoquinone structure include 1,4-benzoquinone, 1,2-benzoquinone, 1,4-naphthoquinone, 1,2-naphthoquinone, 9,10-anthraquinone, and the like.

The method for reducing the content of the compound having a benzoquinone structure in the photocurable adhesive composition of the present invention is not particularly limited. For example, it is preferable to use a compound having no benzoquinone structure or having a benzoquinone structure. The 2-cyanoacrylate compound with a small content of the compound is used as the method of the 2-cyanoacrylate compound used. As a method for producing 2-cyanoacrylate compounds, for example, the following method is known: depolymerizing 2-cyanoacrylate polycondensate, which is a condensation product of a cyanoacetate compound and a formaldehyde compound, and further depolymerizing The obtained crude 2-cyanoacrylate compound is distilled to obtain a refined 2-cyanoacrylate compound. In the depolymerization described above, in the past, at least a compound having a hydroquinone structure was often used as a polymerization inhibitor, and commercial 2-cyanoacrylate compounds contained more compounds having a benzoquinone structure. As a method of reducing the content of the compound having a benzoquinone structure in the 2-cyanoacrylate compound, specifically, it is preferable to include, for example, the use of a polymerization inhibitor that does not have a hydroquinone structure during the aforementioned depolymerization. Method; More preferably, for example, when performing the aforementioned depolymerization and when performing the aforementioned distillation, a method of using a polymerization inhibitor having no hydroquinone structure.

From the viewpoint of storage stability, the aforementioned polymerization inhibitor having no hydroquinone structure preferably contains a compound having a phenolic hydroxyl group, more preferably a compound represented by the following formula (1), and particularly preferably as follows The compound represented by formula (2).

In formula (1) and formula (2), R ₁ to R ₅ each independently represent a hydrogen atom or a substituent other than a hydroxyl group (but excluding phenolic hydroxyl group) that can be bonded to each other to form a ring, and R ₆ represents hydrogen Atom or an alkyl group, R ₇ to R ₁₀ each independently represent an alkyl group, a cycloalkyl group, or an alkenyl group, and R ₁₁ represents a hydrogen atom or a (meth)acryloyl group.

In formula (1), from the viewpoint of storage stability, it is preferable that at least one of R ₁ to R ₅ is the aforementioned substituent, and it is more preferable that R ₁ and R _{5 are} at least the aforementioned substituent, and it is particularly preferable R ₁ , R ₃ and R _{5 are} at least the aforementioned substituents. In formula (1), from the standpoint of storage stability, it is preferable that R ₁ and R ₅ are each independently a linear or branched alkyl group, a cycloalkyl group, or an alkyl group having a structure having a phenolic hydroxyl group. , Or an alkyl group having a (meth)acryloyloxy phenyl structure, more preferably R ₁ is a linear or branched alkyl group and R ₅ is an alkyl group having a structure with a phenolic hydroxyl group or has (methyl) ) The alkyl group of the acryloxyphenyl structure, particularly preferably R ₁ is a linear or branched alkyl group and R ₅ is an alkyl group having a (meth)acryloxy phenyl structure. In formula (1), from the viewpoint of storage stability, R _{3 is} preferably a hydrogen atom, an alkyl group, or an alkoxy group, and preferably a linear or branched alkyl group, a cycloalkyl group, or an alkoxy group , A linear or branched alkyl group, or an alkoxy group is more preferred. The alkyl group in the aforementioned R ₁ , R ₃ and R ₅ is preferably an alkyl group having 1 to 8 carbon atoms, preferably an alkyl group having 1 to 6 carbon atoms, and a linear or branched alkyl group having 1 to 6 carbon atoms. Alkyl, C1-C6 cycloalkyl, tertiary butyl, or 2-methyl-2-butyl is more preferred, and methyl, tertiary butyl, or 2-methyl-2-butyl is preferred Especially good. The aforementioned alkyl group may be linear, branched, or have a ring structure, and may also have a substituent. The substituent may be a group that does not lose the ability to inhibit polymerization, and examples thereof include a halogen atom, an alkoxy group, and an aryl group. In addition, the aforementioned substituents may be further substituted with at least one group selected from the group consisting of the aforementioned substituents and alkyl groups. In formula (1), R ₂ and R ₄ are each independently preferably a hydrogen atom or an alkyl group, preferably a hydrogen atom.

In the formula (2), from the viewpoint of storage stability, R _{6 is} preferably a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and more preferably a hydrogen atom or a methyl group. In formula (2), from the standpoint of storage stability, R ₇ and R ₁₀ are preferably tertiary alkyl groups, preferably tertiary alkyl groups having 4 to 8 carbon atoms, and tertiary butyl or 2- Methyl-2-butyl is particularly good. In formula (2), from the standpoint of storage stability, R ₈ and R _{9 are} preferably C 1-8 alkyl and alkoxy groups, and methyl, tertiary butyl, 2-methyl- 2-butyl, methoxy, ethoxy, propoxy, or butoxy is preferred. In the formula (2), from the viewpoint of storage stability, R _{11 is} preferably a hydrogen atom or a (meth)acryloyl group.

In addition, it is preferable to include a compound whose 5% weight reduction temperature in a nitrogen atmosphere of the aforementioned polymerization inhibitor having no hydroquinone structure is relative to the 2-cyanide contained in the photocurable adhesive composition of the present invention. The boiling point of the base acrylate compound is in the range of -150°C to +50°C.

Among them, from the standpoint of storage stability, the aforementioned polymerization inhibitor that does not have a hydroquinone structure is preferably from 2,2'-methylenebis(6-tertiarybutyl-p-cresol) (221°C ), 2,2'-methylene bis(4-ethyl-6-tertiary butylphenol) (229℃), 2,2'-methylene bis(4-methyl-6-tertiary butyl) Phenol) monoacrylate (234℃), 2,2'-ethylene bis(4,6-bis(tertiary amyl)phenol) monoacrylate (253℃) and 2,2'-methylene At least one compound selected from the group consisting of bis(6-(1-methylcyclohexyl)p-cresol) (285°C). In addition, the temperatures described in parentheses are all 5% weight reduction temperatures.

The aforementioned polymerization inhibitor having no hydroquinone structure can be removed from the 2-cyanoacrylate compound used during the aforementioned depolymerization and the aforementioned distillation, and can also be removed from the 2-cyanoacrylate compound without completely removing it In the case, it is included in the photocurable adhesive composition of the present invention.

>Group 8 transition metal metallocene compound> The photocurable adhesive composition of the present invention contains a metallocene compound of a group 8 transition metal. We speculate that the aforementioned Group 8 transition metal metallocene compound will function as a photopolymerization initiator. In addition, since the light absorption wavelength of the aforementioned Group 8 transition metal metallocene compound is also on the long wavelength side of 500 nm or more, the photocurable adhesive composition of the present invention can be used in a wider wavelength range. Light in the ultraviolet region and visible region can still be photohardened.

As the aforementioned Group 8 transition metal metallocene compound, for example, a metallocene compound having a transition metal element of Group 8 of the periodic table including the following: a ferrocene compound in which the transition metal is iron, and the transition metal is osmium An osmium compound, a ruthenium compound in which the transition metal is ruthenium, a cobaltene compound in which the transition metal is cobalt, and a nickelocene compound in which the transition metal is nickel. From the viewpoint of photocuring properties and storage stability, among these, at least one compound selected from the group consisting of ferrocene and ruthenium is preferred.

As the aforementioned Group 8 transition metal ferrocene compound, specifically, for example, ferrocene, ethyl ferrocene, n-butyl ferrocene, benzyl ferrocene, acetyl ferrocene Iron, tertiary amylferrocene, 1,1'-dimethylferrocene, 1,1'-bis(tertiarybutyl)ferrocene, 1,1'-bis(benzyl) Ferrocene, 1,1'-bis(acetylcyclopentadienyl) iron, bis(pentamethylcyclopentadienyl) iron, bis(cyclopentadienyl) osmium, bis(pentamethyl) Cyclopentadienyl) osmium, dicyclopentadienyl ruthenium (bis(cyclopentadienyl)ruthenium), bis(pentamethylcyclopentadienyl)ruthenium. In addition, as the aforementioned Group 8 transition metal metallocene compound, it can be preferably used: the transition metal of Group 8 of the periodic table having an aromatic electron-based ligand described in JP 2003-277422 A Metallocene compounds. Among these, from the viewpoints of photocuring properties, adhesion speed, cost-effectiveness ratio, and storage stability, the metallocene compound of the aforementioned Group 8 transition metal is preferably selected from ferrocene and ethyldiocene At least one compound selected from the group consisting of iron, n-butyl ferrocene, benzylferrocene and ruthenium, particularly preferably selected from the group consisting of ferrocene, benzylferrocene and At least one compound selected from the group consisting of ruthenium.

The photocurable adhesive composition of the present invention may contain one type or two or more types of the metallocene compound of the group 8 transition metal. From the viewpoint of photocuring properties and storage stability, in the photocurable adhesive composition of the present invention, the content of the group 8 transition metal metallocene compound is preferably 1 ppm to 50,000 ppm, and preferably 10 ppm to 10,000 ppm is preferred, and 20 ppm to 2,000 ppm is particularly preferred.

>2-cyanoacrylate compound> The photocurable adhesive composition of the present invention contains a 2-cyanoacrylate compound. The 2-cyanoacrylate compound used in the present invention is not particularly limited, but a compound represented by the following formula (C) is preferred.

In formula (C), R represents a saturated or unsaturated linear hydrocarbon group, branched chain hydrocarbon group, or cyclic hydrocarbon group with a carbon number of 1 to 20 which may have a halogen atom, or a carbon number which may have a halogen atom 1-20 aromatic hydrocarbon group. Wherein, when R contains an ether bond, any one or both of the hydrocarbon residue chains bonded to the ether bond are saturated or unsaturated linear hydrocarbon groups with 5 to 20 carbon atoms, which may have halogen atoms, A branched chain hydrocarbon group, a cyclic hydrocarbon group, or an aromatic group having 5 to 20 carbon atoms which may have a halogen atom.

Specific examples of 2-cyanoacrylate compounds include ester compounds such as the following esters of 2-cyanoacrylate: methyl, ethyl, ethyl chloro, n-propyl, isopropyl, allyl, Propargyl ester, n-butyl ester, isobutyl ester, n-pentyl ester, n-hexyl ester, pentyl ester, 2-methyl-3-butenyl ester, 3-methyl-3-butenyl ester, 2-pentenyl ester, 6-chlorohexyl ester, cyclohexyl ester, phenyl ester, tetrahydrofurfuryl ester, 2-hexenyl ester, 4-methylpentenyl ester, 3-methyl-2-cyclohexenyl ester, norbornyl ester, heptyl ester , Cyclohexane methyl ester, cycloheptyl ester, 1-methylcyclohexyl ester, 2-methylcyclohexyl ester, 3-methylcyclohexyl ester, 2-ethylcyclohexyl ester, n-octyl ester, 2-octyl Ester, cyclooctyl ester, cyclopentane methyl ester, 2,3-dimethylcyclohexyl ester, n-nonyl ester, isononyl ester, ketononyl ester, n-decyl ester, isodecyl ester, n-dodecyl ester, 2-methoxyethyl, 2-ethoxyethyl, 2-ethoxy-2-ethoxyethyl, butoxyethoxyethyl, 1-(2-methoxy-1- (Methyl ethoxy) propyl ester, 2,2,2-trifluoroethyl, hexafluoroisopropyl, lauryl ester, isotridecanyl ester, cinnamyl ester, cetyl ester, stearyl ester, oleyl ester, two Dodecyl ester, hexadecyl ester, octyl dodecyl ester, benzyl ester, chlorophenyl ester, 2-pentoxy ethyl ester, 2-hexoxy ethyl ester, 2-cyclohexyloxy ethyl ester, 2-(2-Ethylhexyloxy)ethyl and 2-phenoxyethyl.

Among these, the 2-cyanoacrylate compound preferably includes, for example, the following esters of 2-cyanoacrylate: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl , Cyclohexyl ester, phenyl ester, tetrahydrofurfuryl ester, 2-ethylhexyl ester, n-octyl ester, 2-octyl ester, 2-methoxyethyl, 2-ethoxyethyl, or 1-(2 -Methoxy-1-methylethoxy)propyl ester.

The photocurable adhesive composition of the present invention may contain a single type of 2-cyanoacrylate compound or two or more types. From the viewpoints of curability, adhesion speed, and adhesion strength, in the photocurable adhesive composition of the present invention, the content of the 2-cyanoacrylate compound is preferably 40% by mass or more, and more preferably 60% by mass or more. good.

>Light free radical generator> From the viewpoint of photocurability, the photocurable adhesive composition of the present invention preferably further contains a photoradical generator. As the aforementioned photoradical generator, conventional photoradical generators used when photopolymerizing a radically polymerizable compound can be used. Examples of photo-radical generators include: acylgermane-based compounds; acylphosphine oxide-based compounds; acetophenone-based compounds that do not have hydroxyl groups, nitrogen atoms, and sulfide bonds; and do not have hydroxyl groups, nitrogen atoms, and sulfur Benzoin compounds with ether bond, etc. Among them, from the viewpoints of photocurability, adhesion speed, and storage stability, the photoradical generator is preferably an acylgermane-based compound.

As the acylgermane-based compound, preferably, for example, a monoacylgermane-based compound, and a bisacylgermane-based compound, and more preferably, for example, a bisacylgermane-based compound. Preferred examples of the acylgermane compound include Ivocerin (manufactured by Ivoclar Vivadent).

As the acylphosphine oxide-based compound, preferably, for example, a monoacylphosphine oxide-based compound and a bisacylphosphine oxide-based compound, and more preferably, for example, a bisacylphosphine oxide-based compound. As a mono-bis-amidyl phosphine oxide type compound, the compound represented by following formula (A-1) is mentioned preferably, for example.

In the formula (A-1), R ^A1 and R ^A2 each independently represent an alkyl group having 1 to 8 carbons, an alkoxy group having 1 to 8 carbons, a phenyl group, or an alkyl group having 1 to 3 carbons having 1 to 8 A phenyl group substituted by an alkoxy group having 1 to 8 carbon atoms, and R ^A3 represents a linear or branched alkyl group having 1 to 18 carbon atoms which is unsubstituted or substituted with an acetoxy group. Or a cycloalkyl group having 3 to 12 carbons; an alkyl group having 1 to 8 carbons, an alkoxy group having 1 to 8 carbons, an unsubstituted or halogen-substituted aryl group; or the following formula (A- 2) Representation of the base.

In the formula (A-2), R ^A4 and R ^A5 each independently represent an alkyl group having 1 to 8 carbons, an alkoxy group having 1 to 8 carbons, a phenyl group, or having 1 to 3 carbons 1 to 8 A phenyl group substituted by an alkyl group or a C 1-8 alkoxy group, X ^A1 represents a para-phenylene group.

As the phosphine oxide-based compound, for example, methyl isobutyryl methyl phosphinate, methyl isobutyryl phenyl phosphinate, methyl trimethyl acetyl phosphinate, methyl- 2-ethylhexyl phosphinate, isopropyl-2-ethylhexyl phenyl phosphinate, methyl p-tolyl phenyl phosphinate, methyl o-tolyl phenyl phosphinate Phosphonate, methyl-2,4-dimethylbenzyl phenyl phosphinate, methyl phenyl phosphonate, isobutyryl diphenyl phosphine oxide, 2-methyl hexyl Diphenyl phosphine oxide, o-tolyl diphenyl phosphine oxide, p-(tertiary butyl benzyl) diphenyl phosphine oxide, 3-pyridyl carbonyl diphenyl phosphine oxide, propylene diphenyl Phosphine oxide, benzyl diphenyl phosphine oxide, adipyl bis (diphenyl phosphine oxide), etc.

Preferred examples of the bisacetoxyphosphine oxide compound include a compound represented by the following formula (A-3).

In the formula (A-3), R ^p is unsubstituted or is an alkyl group having 1 to 12 carbons, an alkylthio group having 1 to 8 carbons, or a halogen atom, and each R ^p may be the same or different.

In the formula (A-3), the alkyl group having 1 to 12 carbon atoms in R ^p may be linear or branched, for example: methyl, ethyl, propyl, isopropyl, butyl, isobutyl Base, secondary butyl, tertiary butyl, pentyl, isopentyl, hexyl, heptyl, octyl, nonyl, decyl, or dodecyl. It is preferably an alkyl group having 1 to 6 carbons, and more preferably an alkyl group having 1 to 4 carbons. In the formula (A-3), the alkylthio group having 1 to 8 carbon atoms in R ^p may be linear or branched, and examples include methylthio, ethylthio, propylthio, isopropylthio Group, butylthio, tertiary butylthio, hexylthio, or octylthio. Among them, methylthio is preferred. Examples of the halogen atom include a chlorine atom, a bromine atom, and an iodine atom. Among them, chlorine atom is preferred.

Examples of the bis(2,4,6-trimethylbenzyl) phenylphosphine oxide and bis(2,6-dimethoxybenzyl)-based compounds include 2,4,4-Trimethylpentyl phosphine oxide, etc.

Examples of acetophenone-based compounds include 4-phenoxydichloroacetophenone, 4-tertiarybutyldichloroacetophenone, 4-tertiarybutyltrichloroacetophenone, diethoxy Acetophenone and so on. Examples of benzoin-based compounds include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzil dimethyl ketal, and the like.

From the viewpoints of photohardenability, adhesion speed, and storage stability, among these, the photoradical generator is preferably selected from dibenzyldiethylgermanium, bis(4-methoxy Benzoyl) dimethyl germanium, bis(4-methoxybenzyl) diethyl germanium, ferrocenyl germanium, benzyl dimethyl germanium, bis(4-methyl At least one compound selected from the group consisting of benzyl diethyl germanium, bis(4-methyl benzyl) dimethyl germanium, and dibenzyl dibutyl germanium, more preferably It is made from dibenzyl diethyl germanium, bis(4-methoxybenzyl) dimethyl germanium, bis(4-methoxybenzyl) diethyl germanium, bis(4 -At least one compound selected from the group consisting of methylbenzyl)diethylgermanium, bis(4-methylbenzyl)dimethylgermanium, and dibenzyldibutylgermanium .

The photocurable adhesive composition of the present invention may contain one or more photo radical generators alone. From the viewpoints of photocuring properties, adhesion speed, and storage stability, in the photocurable adhesive composition of the present invention, relative to the total mass of the photocurable adhesive composition, the content of the photoradical generator is 0.01% by mass to 5% by mass is preferred, 0.05% by mass to 2% by mass is preferred, and 0.05% by mass to 1% by mass is particularly preferred.

>Polymerization inhibitor> From the viewpoint of storage stability, the photocurable adhesive composition of the present invention preferably further contains a polymerization inhibitor. As the aforementioned polymerization inhibitor, a conventional polymerization inhibitor can be used.

Preferred examples of the polymerization inhibitor include anionic polymerization inhibitors that do not have a hydroquinone structure, such as phosphorus pentoxide, SO ₂ , p-toluenesulfonic acid, methanesulfonic acid, propane sultone, and BF ₃ complex. .

In addition, from the viewpoint of storage stability, it is preferable to use a phenolic radical polymerization inhibitor as the polymerization inhibitor.

The phenolic radical polymerization inhibitor preferably includes, for example, the aforementioned free radical polymerization inhibitor having no hydroquinone structure, such as the compound represented by the formula (1) or (2). From the standpoint of storage stability, as a radical polymerization inhibitor that does not have a hydroquinone structure, it is preferably selected from p-methoxyphenol, butylhydroxyanisole, dibutylhydroxytoluene, di(tertiary) Butyl) hydroxytoluene, 6-tertiary butyl-4-xylenol, 2,6-bis(tertiary butyl)phenol, 2,2'-methylenebis(6-tertiary butyl-p-methyl Phenol), 2,2'-methylene bis(4-ethyl-6-tertiary butyl phenol), 2,2'-methylene bis(4-methyl-6-tertiary butyl phenol) Monoacrylate, 2,2'-ethylenebis(4,6-bis(tertiary pentyl)phenol)monoacrylate and 2,2'-methylenebis(6-(1-methylcyclohexyl) ) At least one selected from the group consisting of p-cresol).

In addition, from the standpoint of storage stability, as the aforementioned phenolic radical polymerization inhibitor, it is preferable to include a radical polymerization inhibitor having a hydroquinone structure, and more preferably a free radical polymerization inhibitor having a 1,4-hydroquinone structure. -Based polymerization inhibitor. From the standpoint of storage stability, as a radical polymerization inhibitor having a hydroquinone structure, it is preferably selected from 1,4-hydroquinone, 1,2-hydroquinone, methylhydroquinone, 2,6-dihydroquinone Selected from the group consisting of methylhydroquinone, 2,6-di(tertiarybutyl)hydroquinone, 1,4-dihydroxynaphthalene, 1,2-dihydroxynaphthalene and 9,10-dihydroxyanthracene At least one compound, more preferably from 1,4-hydroquinone, 1,2-hydroquinone, methylhydroquinone, methoxyhydroquinone, 2,6-dimethylhydroquinone and 2,6-dihydroquinone At least one selected from the group consisting of (tertiary butyl)hydroquinone, particularly preferably at least one selected from the group consisting of hydroquinone, methylhydroquinone and methoxyhydroquinone.

Furthermore, the addition of a radical polymerization inhibitor having a hydroquinone structure is more preferably after distillation and purification when preparing the photocurable adhesive composition or when manufacturing the 2-cyanoacrylate compound which is the raw material. It is preferably when preparing a light-curable adhesive composition.

The photocurable adhesive composition of the present invention may contain one type of polymerization inhibitor alone or two or more types. Among them, from the viewpoint of storage stability, it is preferable to contain an anionic polymerization inhibitor without a hydroquinone structure, and more preferably to contain a radical polymerization inhibitor without a hydroquinone structure and an anionic polymerization inhibitor without a hydroquinone structure. The inhibitor is particularly preferably a radical polymerization inhibitor having a hydroquinone structure, a radical polymerization inhibitor having no hydroquinone structure, and an anionic polymerization inhibitor having no hydroquinone structure. With respect to the total mass of the photocurable adhesive composition, the aforementioned polymerization inhibitor is preferably 50 ppm to 1% by mass, and more preferably 20 ppm to 5,000 ppm. In addition, the content of the radical polymerization inhibitor having a hydroquinone structure is preferably 10 ppm or more and 1000 ppm or less, and more preferably 20 ppm or more and 500 ppm or less.

>Other additives> The photocurable adhesive composition of the present invention may contain additives other than the aforementioned components. There are no particular restrictions on other additives, and conventional additives can be used. As other additives, for example, suitable amounts of the following can be blended within a range that does not impair the curability and adhesive strength of the photocurable adhesive composition according to the purpose: anionic polymerization accelerator, plasticizer, thickener, hair Fuming silica, particles, fillers, colorants, fragrances, solvents, strength enhancers, etc. The content of other additives is not particularly limited, but it is preferably 20% by mass or less, and more preferably 10% by mass or less with respect to the total mass of the photocurable adhesive composition.

Examples of the anionic polymerization accelerator include polyalkylene oxides, crown ethers, silicocrown ethers, calixarenes, cyclodextrins, and gallic phenol-based cyclic compounds. The so-called polyalkylene oxides refer to polyalkylene oxides and their derivatives. Examples include Japanese Patent Publication No. 60-37836, Japanese Patent Publication No. 1-43790, Japanese Patent Application Publication No. 63-128088, It is disclosed in Japanese Patent Laid-Open No. 3-167279, the specification of U.S. Patent No. 4386193, and the specification of U.S. Patent No. 4424327. Specifically, for example: (1) Polyalkylene oxide such as diethylene glycol, triethylene glycol, polyethylene glycol, and polypropylene glycol; (2) Polyethylene glycol monoalkyl ester, polyethylene glycol two Alkyl ester, polypropylene glycol dialkyl ester, diethylene glycol monoalkyl ether, diethylene glycol dialkyl ether, dipropylene glycol monoalkyl ether, dipropylene glycol dialkyl ether and other polyalkylene oxide derivatives Wait. Examples of the crown ethers include those disclosed in Japanese Patent Publication No. 55-2236 and Japanese Patent Application Publication No. 3-167279. Specifically, for example: 12-crown-4, 15-crown-5, 18-crown-6, benzo-12-crown-4, benzo-15-crown-5, benzo-18-crown- 6. Dibenzo-18-crown-6, dibenzo-24-crown-8, dibenzo-30-crown-10, tribenzo-18-crown-6, asymmetric dibenzo-22- Crown-6, dibenzo-14-crown-4, dicyclohexyl-24-crown-8, cyclohexyl-12-crown-4, 1,2-decalyl-15-crown-5, 1,2-naphthalene And-15-crown-5, 3,4,5-naphthyl-16-crown-5, 1,2-methylbenzo-18-crown-6, 1,2-tertiarybutyl-18-crown 6. 1,2-vinylbenzo-15-crown-5, etc. Examples of the silicocrown ethers include those disclosed in Japanese Patent Application Laid-Open No. 60-168775. Specifically, for example, dimethylsilica-11-crown-4, dimethylsilica-14-crown-5, and dimethylsilica-17-crown-6 can be mentioned. Examples of cyclic aromatic hydrocarbons include those disclosed in Japanese Patent Application Publication No. 6-179482, Japanese Patent Application Publication No. 62-235379, and Japanese Patent Application Publication No. 63-88152. Specifically, for example: 5,11,17,23,29,35-hexa(tertiary butyl)-37,38,39,40,41,42-hexahydroxy ring [6] arene, 37,38 ,39,40,41,42-hexahydroxy ring [6] aromatic hydrocarbon, 37,38,39,40,41,42-hexa (2-keto-2-ethoxy) ethoxy ring [6] aromatic hydrocarbon , 25,26,27,28-Tetra (2-keto-2-ethoxy) ethoxy cyclo[4] arene, tetra (4-tertiary butyl-2-methylenephenoxy) ethyl Glycol acetate and so on. Examples of the cyclodextrins include those disclosed in JP 5-505835 A, etc. Specifically, for example, α-, β-, or γ-cyclodextrin can be mentioned. Examples of the gallic phenol-based cyclic compounds include those disclosed in JP 2000-191600 A and the like. Specifically, for example: 3,4,5,10,11,12,17,18,19,24,25,26-dodecethoxy carbon methoxy-C-1, C-8, C -15,C-22-Tetramethyl[14]-metacyclic aromatic (3,4,5,10,11,12,17,18,19,24,25,26-dodecaethoxycarbomethoxy-C-1,C- 8,C-15,C-22-tetramethyl[14]-metacyclophane). Only one type of these anionic polymerization accelerators may be used, or two or more types may be used in combination.

A plasticizer can be contained as long as it does not impair the effect of this invention. As this plasticizer, for example, acetyl triethyl citrate, acetyl tributyl citrate, dimethyl adipate, diethyl adipate, dimethyl sebacate, ortho Dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisodecyl phthalate, dihexyl phthalate, diheptyl phthalate, phthalate Dioctyl dicarboxylate, bis(2-ethylhexyl) phthalate, diisononyl phthalate, diisododecyl phthalate, bis(pentadecyl phthalate) ), dioctyl terephthalate, diisononyl isophthalate, decyl toluate, bis(2-ethylhexyl) camphorate, 2-ethylhexyl cyclohexanecarboxylate, fumaric acid Diisobutyl ester, diisobutyl maleate, glycerol trihexanoate, 2-ethylhexyl benzoate, dipropylene glycol dibenzoate, etc. Among these, from the viewpoints of good compatibility with 2-cyanoacrylate and high plasticizing efficiency, tributyl acetyl citrate, dimethyl adipate, and phthalate Dimethyl formate, 2-ethylhexyl benzoate, and dipropylene glycol dibenzoate are preferred. Only one type of these plasticizers may be used, or two or more types may be used in combination. In addition, the content of the plasticizer is not particularly limited. When the content of the 2-cyanoacrylate compound is 100 parts by mass, it is preferably 3 to 50 parts by mass, and more preferably 10 to 45 parts by mass. , More preferably 20 to 40 parts by mass. If the content of the plasticizer is 3 parts by mass to 50 parts by mass, the retention rate of the adhesive strength after the thermal cycle resistance test can be improved.

In addition, as thickeners, for example, polymethyl methacrylate, copolymers of methyl methacrylate and acrylate, copolymers of methyl methacrylate and other methacrylates, acrylic rubber, poly Vinyl chloride, polystyrene, cellulose ester, polyalkyl-2-cyanoacrylate, and ethylene-vinyl acetate copolymer. Only one kind of these thickeners may be used, or two or more kinds may be used in combination.

The photocurable adhesive composition of the present invention can also contain fumed silica. The fuming silica is anhydrous silica with ultrafine powder (preferably with a primary particle size of 500 nm or less, particularly preferably a primary particle size of 1 nm to 200 nm). The anhydrous silica is for example: silicon tetrachloride As a raw material, it is anhydrous silicon oxide that is produced by oxidation in a gas phase in a high-temperature flame (preferably, the primary particle size is 500 nm or less, and particularly preferably, the primary particle size is 1 nm to 200 nm). And there are hydrophilic silica with high hydrophilicity and hydrophobic silica with high hydrophobicity. As the fuming silica, any one can be used. From the viewpoint of good dispersibility to the 2-cyanoacrylate compound, hydrophobic silica is preferred.

As the hydrophilic silica, various commercially available products can be used, and examples thereof include AEROSIL 50, 130, 200, 300, and 380 (the above are trade names, manufactured by Japan AEROSIL Co., Ltd.). The specific surface areas of these hydrophilic silicas are 50±15 m ² /g, 130±25 m ² /g, 200±25 m ² /g, 300±30 m ² /g, and 380±30 m ² /g. . In addition, commercially available hydrophilic silica can be used: REOLOSIL QS-10, QS-20, QS-30 and QS-40 (the above are trade names, manufactured by TOKUYAMA), etc. The specific surface areas of these hydrophilic silicas are 140±20 m ² /g, 220±20 m ² /g, 300±30 m ² /g, and 380±30 m ² /g. In addition, commercially available hydrophilic silica made by CABOT can also be used.

In addition, as hydrophobic silica, products produced in the following manner can be used: in the presence or absence of a solvent, a specific compound is brought into contact with hydrophilic silica, and it is preferably heated to treat the surface of the hydrophilic silica. For treatment, the specific compound is: a compound that can react with the hydroxyl groups present on the surface of hydrophilic silica to form a hydrophobic group; or a compound that can be adsorbed on the surface of hydrophilic silica and can form a hydrophobic layer on the surface .

Examples of compounds used for surface treatment of hydrophilic silica for hydrophobization include various silane coupling agents of alkyl, aryl, and aralkyl groups with hydrophobic groups such as n-octyltrialkoxysilane. ;Silicating agents such as methyltrichlorosilane, dimethyldichlorosilane, and hexamethyldisilazane; silicone oils such as polydimethylsiloxane; higher alcohols such as stearyl alcohol; and, stearin Higher fatty acids such as acid. As the hydrophobic silica, a product that is hydrophobized by using any compound can be used.

Commercially available hydrophobic silicas include, for example, AEROSIL RY200 and R202 which are hydrophobized by surface treatment with silicone oil, and AEROSIL R974 which is hydrophobized by surface treatment with dimethyl silylating agent, R972, R976, AEROSIL R805 hydrophobized by surface treatment with n-octyltrimethoxysilane, AEROSIL R811, R812 (the above are trade names, Japan AEROSIL Co., Ltd.); and REOLOSIL MT-10 (trade name, made by Tokuyama Co., Ltd.) which has been surface-treated with methyltrichlorosilane and hydrophobized. The specific surface areas of these hydrophobic silicas are 100±20 m ² /g, 100±20 m ² /g, 170±20 m ² /g, 110±20 m ² /g, 250±25 m ² /g , 150±20 m ² /g, 150±20 m ² /g, 260±20 m ² /g, 120±10 m ² /g.

In the photocurable adhesive composition of the present invention, when the content of the 2-cyanoacrylate compound is 100 parts by mass, the preferred content of fuming silica is 1 part by mass to 30 parts by mass. Although it also varies with the type of 2-cyanoacrylate compound and the type of fuming silica, the preferred content of the fuming silica is 1 part by mass to 25 parts by mass, and the particularly preferred content is 2 parts by mass. Parts ~ 20 parts by mass. If the content of fuming silica is 1 part by mass to 30 parts by mass, it is possible to produce an adhesive composition with good workability without impairing the curability and adhesive strength of the photocurable adhesive composition. .

The curing method of the photocurable adhesive composition of the present invention is not particularly limited as long as it can be polymerized and cured by a 2-cyanoacrylate compound. It can be cured by light, or by moisture, etc. Moisture hardens. When the photocurable adhesive composition of the present invention is cured by light, it can be cured by the following methods: using high-pressure mercury lamp, halogen lamp, xenon lamp, LED (light emitting diode) lamp, solar Light, etc. to irradiate ultraviolet and visible light.

The storage method of the photocurable adhesive composition of the present invention can be stored by a conventional storage method, for example: preferably in an environment with no or less moisture and oxygen (for example, less than 0.01% by volume) Mixing, more preferably mixing in an inert gas environment. Examples of the inert gas include nitrogen, argon, and the like. In addition, the photocurable adhesive composition of the present invention is preferably stored under shading.

The photocurable adhesive composition of the present invention can be used for the conventional use as a 2-cyanoacrylate composition and the use of a photocurable adhesive composition. For example, it can be used as a so-called instant adhesive, and can be used as a photocurable instant adhesive. Since the photocurable adhesive composition of the present invention has photocurability and moisture curability and is excellent in storage stability, it can be used in a wide range of fields such as general use, industrial use, and medical use. Specifically, it can be suitably used for the adhesion and fixation or coating of the same or different kinds of articles such as the following: sealing of electronic parts, mounting of reels and wire loops in fishing rods, wire materials such as coils Fixing, fixing the magnetic head on the pedestal, filling agent for treating teeth, adhesion and decoration of artificial nails, etc. [Example]

Hereinafter, the present invention will be specifically explained based on examples. Furthermore, the present invention is not limited by these embodiments. In addition, in the following, "parts" and "%" mean "parts by mass" and "% by mass", unless otherwise specified.

(Example 1) The photocurable adhesive composition of Example 1 was obtained by mixing with 2-octyl 2-cyanoacrylate (2-OctCA) with an acid content (acid content) of 0.20 μg equivalent in the following manner: BF ₃ -methanol complex (polymerization inhibitor) becomes 20 ppm in the composition; SUMILIZER MDP-S (polymerization inhibitor, the following compound) becomes 1,000 ppm in the composition; Ferrocene (FeCp ₂ , The group 8 transition metal metallocene compound, manufactured by Wako Pure Chemical Industries, Ltd.) becomes 600 ppm in the composition; Ivocerin (photo-radical generator, the following compound, manufactured by Ivoclar Vivadent) becomes 3,000 in the composition ppm.

SUMILIZER MDP-S

SUMILIZER MDP-S

Ivocerin

Ivocerin

>Viscosity> Use an E-type viscometer to measure at 25°C with an arbitrary number of rotations.

>Storage stability assessment> After adding 1.5 g of the obtained photocurable adhesive composition to a light-shielding sealed container, and storing it in a 60°C constant temperature chamber, the initial and elapsed time viscosity was measured at the time points described in Table 1. The smaller the change in viscosity, the better the storage stability. The evaluation results are shown in Table 1.

>Adhesion speed> After adding the obtained light-curing adhesive composition to a light-shielding sealed container and storing it in a constant temperature room at 60°C, the initial and elapsed time is the light-curing adhesive composition at the time points described in Table 1. In accordance with JIS K 6861 "Test Methods for α-Cyanoacrylate Adhesives", the adhesion speed was measured in an environment of 23°C and 60%RH. The test pieces used are as follows. Test piece: ABS resin made by UMG ABS, trade name "GSE" The evaluation results are shown in Table 1.

>Evaluation of photocuring properties> After adding the obtained photocuring adhesive composition to a light-shielding sealed container and storing it in a constant temperature room at 60°C, the initial and elapsed time are taken as the time points described in Table 1. The light-curable adhesive composition is formed in a polyethylene container to form a liquid film with a thickness of 1 mm. A spot type UV irradiation device (Spot Cure UIS-25102, manufactured by USHIO Electric Co., Ltd.) equipped with a longpass filter (GG395 manufactured by Schott) was used at 150 W/cm ² (wavelength After irradiating it with the intensity of 405 nm, the irradiation time until the sample is completely hardened is measured. Furthermore, Example 7 and Comparative Example 5 take into account the absorption wavelength of the optical radical generator, and in the case of not equipped with a long-pass filter, the same applies to 150 W/cm ² (UV-A: at the wavelength 320 nm～390 nm value) to irradiate it. The smaller the value, the better the photocurability. The evaluation results are shown in Table 1.

(Examples 2 to 5, and Comparative Examples 1 and 2) Except for adding 1,4-hydroquinone (HQ), 1,4-benzoquinone (BQ), and 2-hydroxy-1,4-naphthoquinone to the composition so as to become the amount described in Table 1, the rest It carried out similarly to Example 1, and prepared the photocurable adhesive composition separately. Using the obtained photocurable adhesive composition, it carried out similarly to Example 1, and performed various evaluations. The evaluation results are summarized as shown in Table 1.

[Table 1]

(Examples 6 to 8, and Comparative Examples 3 to 5) In addition to using the 2-octyl 2-cyanoacrylate (2-OctCA) equivalent to 0.62 μg of the acid content (acid content), bis(2, 2-OctCA) was added to the composition so that it became the amount described in Table 2. 4,6-Trimethylbenzyl)phenylphosphine oxide (manufactured by iGM, trade name "Omnirad819") or 2,2-dimethoxy-2-phenylacetone (manufactured by iGM, trade name " Omnirad 651") was used to replace Ivocerin, and the rest was performed in the same manner as in Example 1, and the photocurable adhesive compositions were prepared separately. Using the obtained photocurable adhesive composition, it carried out similarly to Example 1, and performed various evaluations. The evaluation results are summarized as shown in Table 2.

[Table 2]

(Examples 9-11, and Comparative Examples 6 and 7) Except that 2-OctCA was changed to 2-ethoxyethyl 2-cyanoacrylate (EtOEtCA), and ferrocene (FeCp ₂ , Group 8 The content of transition metal (metallocene compound) and Ivocerin (photo-radical generator) was changed to the amount described in Table 3, and 1,4-hydrogen was added to the composition so that it became the amount described in Table 3 Except for quinone (HQ) or 1,4-benzoquinone (BQ), the rest was performed in the same manner as in Example 1, and the photocurable adhesive composition was prepared separately. Using the obtained photocurable adhesive composition, it carried out similarly to Example 1, and performed various evaluations. The evaluation results are summarized as shown in Table 3.

[table 3]

(Examples 12-14 and Comparative Examples 8 and 9) Except that 2-OctCA was changed to isobutyl 2-cyanoacrylate (iBuCA), and ferrocene (FeCp ₂ , a group 8 transition metal ferrocene The content of metal compound) and Ivocerin (photo-radical generator) was changed to the amount described in Table 4, and 1,4-hydroquinone (HQ) was added to the composition to become the amount described in Table 4 Or, except for 1,4-benzoquinone (BQ), the rest was performed in the same manner as in Example 1, and the photocurable adhesive compositions were prepared separately. Using the obtained photocurable adhesive composition, it carried out similarly to Example 1, and performed various evaluations. The evaluation results are summarized as shown in Table 4.

[Table 4]

As shown in Tables 1 to 4, compared with the photocurable adhesive composition of the comparative example, the storage stability of the photocurable adhesive composition of the present invention, that is, the photocurable adhesive composition of the examples More excellent.

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Claims (9)

A light-curing adhesive composition, which contains: Group 8 transition metal metallocene compounds, and 2-cyanoacrylate compound; In addition, the content of the compound that does not contain a quinone structure or a compound that has a benzoquinone structure exceeds 0 ppm and does not reach 4 ppm. The photocurable adhesive composition according to claim 1, wherein the group 8 transition metal metallocene compound is at least one compound selected from the group consisting of ferrocene and ruthenium . The photocurable adhesive composition according to claim 1, wherein the group 8 transition metal metallocene compound is ferrocene. The photocurable adhesive composition according to claim 1, which further contains a photoradical generator. The photocurable adhesive composition according to claim 4, wherein the photoradical generator is selected from the group consisting of an acyl germane compound, an acyl phosphine oxide compound, and an alkyl phenone compound At least one compound selected. The photocurable adhesive composition according to claim 1, which further contains a polymerization inhibitor. The photocurable adhesive composition according to claim 6, wherein the polymerization inhibitor includes a phenolic radical polymerization inhibitor. The photocurable adhesive composition according to claim 6, wherein the polymerization inhibitor includes a radical polymerization inhibitor having a hydroquinone structure. The photocurable adhesive composition according to claim 7 or 8, wherein the content of the polymerization inhibitor is 10 ppm or more and 1,000 ppm or less.