JP2003096051A - Photocationic polymerization initiator and hardened product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photocationic-setting resin composition which is excellent in transparency and stability during its storage and does not produce benzene from the components of photocationic polymerization initiators of hardened products even if it is radiated with a light and a hardened film obtained from it is heat-treated. SOLUTION: An aromatic sulfonic acid ester compound represented by formula (1) is synthesized, and then the compound thus obtained is blended with a cationic polymerizable compound to give the photocationic-setting resin composition.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel aromatic sulfonic acid ester compound, a photocationic polymerization initiator comprising the same, and a photocurable composition containing the same and a cationically polymerizable compound, which can be polymerized by irradiation with active energy rays. Composition and a cured product thereof.

[0002]

2. Description of the Related Art Photocurable resin compositions have been extensively studied and industrially used in the fields of printing inks, paints, coatings, liquid resist inks, etc., in order to save energy, space, and pollution. Most of these utilize the photoradical polymerization reaction of unsaturated double bonds. Further, recently, the industrial application of a method of incorporating a cationic photopolymerization initiator into an epoxy resin and performing cationic photopolymerization has been investigated. The method of photocationic polymerization by irradiating an active energy ray such as an ultraviolet ray or an electron beam with a cationically polymerizable substance such as an epoxy resin is compared with a method of photoradical polymerization of an acrylate compound or the like by irradiation with an active energy ray. Curing shrinkage is small and it is not affected by oxygen during curing.
It has various characteristics that are advantageous when compared with the method of curing by photo-radical polymerization. When the cationically polymerizable substance is photocationically polymerized by irradiating it with active energy rays such as ultraviolet rays and electron beams, a photocationic polymerization initiator that generates an acid upon irradiation with active energy rays is added. As photocationic polymerization initiators, onium salts represented by aromatic diazonium salts, iodonium salts, sulfonium salts, phosphonium salts, selenonium salts, and metal arene complexes are already known, and these are mixed with a cationically polymerizable substance. Then, when the active energy ray is irradiated, the Bronsted acid or the Lewis acid generated by the irradiation of the active energy ray acts on the cationically polymerizable substance to induce the polymerization. US Pat. No. 4,690,054
No. 4,450,360, No. 4,576,999, No. 4,640,967, Canadian Patent No. 1274646, and European Patent No. 203829, and Advances in Polymer S.
science 62, Initiators-Pory
Reactions-Optical Activ
ty, p1 to p48, Springer-Verlag
(1984), latest UV curing technology, edited by Technical Information Society, p.
29 (1991). In particular,
Several aromatic sulfonium salt type photocationic polymerization initiators are commercially available as industrially useful photocationic polymerization initiators.

[0003]

However, the photocationic curable resin composition generally has a problem that the curing rate is slower than that of the photoradical curable resin composition containing an acrylic ester compound or the like. Especially, in the case of an aromatic sulfonium salt type photocationic polymerization initiator, the odor of the cured product may be a problem. In order to overcome these problems, an aromatic sulfonium salt type photocationic polymerization initiator having a specific group has been proposed in JP-A-56-55420. However, even with these proposed aromatic sulfonium salt type photocationic polymerization initiators, the drawback of slow curing rate and the problem of odor are somewhat solved, but they are not sufficient. At present, some aromatic sulfonium salt type photocationic polymerization initiators and aromatic iodonium salt type photocationic polymerization initiators are available on the market. However, in the case of aromatic sulfonium salt-type photocationic polymerization initiators that are commercially available, there are no sulfur atoms in the structure such as phenylthio group or phenyl group bonded to sulfur atom forming sulfonium cation. It has a benzene ring that only has a bond with. The structure has a benzene ring which only has a bond with a sulfur atom. When a resin composition containing a photocationic polymerization initiator is irradiated with active energy rays to be cured, or after being irradiated with active energy rays and then subjected to heat treatment to obtain a sufficiently cured film, the photocationic There is a possibility that benzene, which is a harmful substance, may be liberated by breaking the bond between the carbon atom having a relatively weak bond and the sulfur atom in the structure of the polymerization initiator.

[0004]

Means for Solving the Problems As a result of intensive research to solve the above-mentioned problems, the present inventor produced a novel aromatic sulfonic acid ester compound using a triphenylmethanol derivative as a raw material and By using it as a cationic polymerization initiator, it has excellent curability and is further cured by irradiation with active energy rays, or after being irradiated with active energy rays, it is subjected to heat treatment to obtain a sufficiently cured film. In this case, we succeeded in obtaining a photocationic curable resin composition that does not release odor or benzene. That is, the present invention provides [1] the following formula (1)

[0005]

[Chemical 2]

(Wherein R ₁ is a methyl group, an ethyl group, a methoxy group, an ethoxy group or a fluorine atom, and R ₂ is a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a carbon atom, respectively. An aromatic sulfonic acid ester compound represented by a linear or branched alkoxy group of formulas 1 to 4 or a fluorine atom. [2] A photocationic polymerization initiator (A) comprising an aromatic sulfonic acid ester compound represented by the formula (1) described in [1]. [3] A photocurable resin composition comprising the cationic photopolymerization initiator (A) according to [2] and one or more cationically polymerizable compounds (B). [4] Of the one or more kinds of cationically polymerizable compounds (B) described in [3], at least one kind is 1 in one molecule.
The photocurable resin composition according to [3], which is a compound having one or more epoxy groups. [5] The content of the photocationic polymerization initiator (A) is 1 or 2 or more with respect to the cationically polymerizable compound (B),
The photocurable resin composition according to [2] or [4], which is 0.1 to 10% by weight. [6] A cured product obtained by curing the photocurable resin composition according to any one of [3] to [5]. Regarding

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The cationic photopolymerization initiator (A) represented by the formula (1) of the present invention has the formula (2)

[0008]

[Chemical 3]

(Wherein R ₁ represents a methyl group, an ethyl group, a methoxy group, an ethoxy group or a fluorine atom, and X represents a chlorine atom or a bromine atom), and a halide of a benzenesulfonic acid derivative. , Formula (3)

[0010]

[Chemical 4]

(Here, R ₂ is a hydrogen atom and has 1 to 4 carbon atoms.
Represents a linear or branched alkyl group, a linear or branched alkoxy group having 1 to 4 carbon atoms, or a fluorine atom. It can be obtained by reacting a triphenylmethanol derivative represented by For the reaction, a known synthesis method of a p-toluenesulfonic acid ester derivative using an ordinary p-toluenesulfonic acid chloride and an alcohol compound can be applied.

Specific examples of the halide of the benzenesulfonic acid derivative represented by the formula (2) used in the reaction include, for example, p-toluenesulfonic acid chloride,
p-toluenesulfonic acid bromide, m-toluenesulfonic acid chloride, m-toluenesulfonic acid bromide, o-toluenesulfonic acid chloride, o-toluenesulfonic acid bromide, p-ethylbenzenesulfonic acid chloride, p-ethylbenzenesulfonic acid bromide, p -Methoxybenzenesulfonic acid chloride, p-
Examples thereof include methoxybenzenesulfonic acid bromide, p-ethoxybenzenesulfonic acid chloride, p-ethoxybenzenesulfonic acid bromide, p-fluorobenzenesulfonic acid chloride and p-fluorobenzenesulfonic acid bromide.

Further, the formula (3) used in the reaction here is used.
Specific examples of the triphenylmethanol derivative represented by are, for example, triphenylmethanol, tri (p-toluyl) methanol, tri (p-ethylphenyl) methanol, tri (pn-propylphenyl) methanol, tri (methanol). p-isopropylphenyl) methanol, tri (pn-butylphenyl) methanol, tri (p-)
Isobutylphenyl) methanol, tri (p-tert)
-Butylphenyl) methanol, tri (p-methoxyphenyl) methanol, tri (p-ethoxyphenyl) methanol, tri (p-fluorophenyl) methanol and the like can be mentioned.

The photocationic polymerization initiator (A) represented by the above formula (1) is represented by the halide of the benzenesulfonic acid derivative represented by the above formula (2) and the above formula (3). It can be obtained by condensing a triphenylmethanol derivative in a basic solvent. Formula (3)
The amount of the halide of the benzenesulfonic acid derivative represented by the formula (2) with respect to the triphenylmethanol derivative represented by the formula (3) is 1.0 mol of the triphenylmethanol derivative represented by the formula (3). The halide of the benzenesulfonic acid derivative represented by the above formula (2) is preferably charged in an amount of 0.9 to 3.0 mol, more preferably 1.1 to 1.5 mol. When it is difficult for the halide of the benzenesulfonic acid derivative represented by the formula (2) and the triphenylmethanol derivative represented by the formula (3) to react with each other, the triphenylmethanol derivative represented by the formula (3) is previously expressed. It is advisable to convert the phenylmethanol derivative into an alcoholate with lithium hydride, sodium hydride, potassium hydride or the like, and then react with the halide of the benzenesulfonic acid derivative represented by the above formula (2).

The photocationic polymerization initiator (A) represented by the above formula (1) is prepared by charging the triphenylmethanol derivative represented by the above formula (3) in a basic solvent, stirring and dispersing. Then, the halide of the benzenesulfonic acid derivative represented by the above formula (2) is added little by little to react, or the halide of the benzenesulfonic acid derivative represented by the above formula (2) and the above formula (3) ) In the organic solvent such as hydrocarbons such as toluene and xylene that are not reactive with the triphenylmethanol derivative represented by the formula (2), the halide of the benzenesulfonic acid derivative represented by the above formula (2) and the above A triphenylmethanol derivative represented by the formula (3) is charged, and a basic solvent is added little by little and reacted. Specific examples of the basic solvent used at this time include, for example, aqueous sodium hydroxide solution,
Aqueous solution of alkali metal salt such as potassium hydroxide aqueous solution, sodium hydrogen carbonate aqueous solution, potassium hydrogen carbonate aqueous solution, sodium carbonate aqueous solution, potassium carbonate aqueous solution, monoethylamine, diethylamine, triethylamine, isopropylamine, diisopropylamine, n-butylamine, di-n. -Butylamine, tri-n-butylamine,
Isobutylamine, diisobutylamine, n-pentylamine, di-n-pentylamine, tri-n-pentylamine, 2-ethylbutylamine, n-heptylamine, 2-ethylhexylamine, di-n-octylamine, cyclohexylamine, Dicyclohexylamine,
Organic substances such as aniline, monomethylaniline, dimethylaniline, diethylaniline, o-toluidine, pyridine, α-picoline, β-picoline, γ-picoline, 2,4-lutidine, 2,6-lutidine, quinoline, morpholine and ethylmorpholine. Mention may be made of amines. In addition, the photocationic polymerization initiator (A) represented by the formula (1) is replaced by a halide of a benzenesulfonic acid derivative represented by the formula (2) and triphenylmethanol represented by the formula (3). When the derivative is charged in an organic solvent such as hydrocarbons which is not reactive with these compounds and the reaction is obtained by adding a basic solvent little by little, it is preferable to use an organic amine as the basic solvent, If an aqueous solution of an alkali metal salt is used, the reaction solution will separate into two layers,
The reaction rate may decrease significantly.

The amount of the basic compound charged is 1.0% of the triphenylmethanol derivative represented by the above formula (3).
The amount is preferably 1.0 to 20.0 mol, and more preferably 2.0 to 6.0 mol. These basic compounds are preferably used as an aqueous solution when the basic compound is an alkali metal salt, and may be used as they are when the basic compound is an organic amine. When the alkali metal salt is used as an aqueous solution, it is preferable to prepare the alkali metal salt in a ratio of 10 to 50 w% with respect to water, and more preferably 20 to 40 w%.
In the synthesis of the photocationic polymerization initiator (A) represented by the formula (1), the triphenylmethanol derivative represented by the formula (3) is charged in a basic solvent and stirred to prepare the compound represented by the formula (2). When the halide of the benzenesulfonic acid derivative represented by the formula (1) is added and reacted, the halide of the benzenesulfonic acid derivative represented by the formula (2) is added little by little while paying attention to heat generation. In addition, the synthesis of the photocationic polymerization initiator (A) represented by the above formula (1) is performed by using the halide of the benzenesulfonic acid derivative represented by the above formula (2) and the tricarboxylic acid represented by the above formula (3). When the phenylmethanol derivative is first charged in a non-reactive organic solvent and the basic solvent is added for the reaction, the basic solvent should be added little by little while paying attention to heat generation.
The charging temperature and the reaction temperature are preferably −50 to 35 ° C., more preferably 0 to 20 ° C. Further, the reaction time is preferably 5 to 120 hours, more preferably 24 to 72 hours.

Specific examples of the photocationic polymerization initiator (A) of the present invention obtained as described above include, for example, p-
Triphenylmethyl toluenesulfonate, tri (p-toluyl) methyl p-toluenesulfonate, tri (p-ethylphenyl) methyl p-toluenesulfonate, tri (pn-propylphenyl) methyl p-toluenesulfonate, Tri (p-isopropylphenyl) methyl p-toluenesulfonate, tri (p-toluenesulfonate)
n-butylphenyl) methyl, p-toluenesulfonate tri (p-isobutylphenyl) methyl, p-toluenesulfonate tri (p-tert-butylphenyl) methyl, p-toluenesulfonate tri (p-methoxyphenyl) methyl , P-toluenesulfonate tri (p-ethoxyphenyl) methyl, p-toluenesulfonate tri (p
-Fluorophenyl) methyl, triphenylmethyl m-toluenesulfonate, tri (p-m-toluenesulfonate)
-Toluyl) methyl, triphenylmethyl o-toluenesulfonate, tri (p-toluyl) methyl o-toluenesulfonate, triphenylmethyl p-ethylbenzenesulfonate, tri (p-toluyl) methyl p-ethylbenzenesulfonate, p -Tri (p-ethylphenyl) methyl ethylbenzenesulfonate, tri (p-methoxyphenyl) methyl p-ethylbenzenesulfonate, tri (p-ethoxyphenyl) p-ethylbenzenesulfonate
Methyl, tri (p-fluorophenyl) methyl p-ethylbenzenesulfonate, triphenylmethyl p-methoxybenzenesulfonate, tri (p-toluyl) methyl p-methoxybenzenesulfonate, tri (p-p-methoxybenzenesulfonate) Ethylphenyl) methyl, p-methoxybenzenesulfonate tri (p-methoxyphenyl) methyl, p-methoxybenzenesulfonate tri (p)
-Ethoxyphenyl) methyl, tri (p-fluorophenyl) methyl p-methoxybenzenesulfonate, triphenylmethyl p-ethoxybenzenesulfonate, tri (p-toluyl) methyl p-ethoxybenzenesulfonate, p-ethoxybenzenesulfone Acid tri (p-ethylphenyl) methyl, p-ethoxybenzenesulfonate tri (p-methoxyphenyl) methyl, p-ethoxybenzenesulfonate tri (p-ethoxyphenyl) methyl,
Tri (p-fluorophenyl) methyl p-ethoxybenzenesulfonate, triphenylmethyl p-fluorobenzenesulfonate, tri (p-toluyl) methyl p-fluorobenzenesulfonate, tri (p-ethyl) p-fluorobenzenesulfonate Phenyl) methyl, tri (p-methoxyphenyl) methyl p-fluorobenzenesulfonate, tri (p-ethoxyphenyl) methyl p-fluorobenzenesulfonate, tri (p-fluorophenyl) methyl p-fluorobenzenesulfonate, etc. Can be mentioned.

Preferred examples of the cationic photopolymerization initiator (A) of the present invention include, for example, p-
Toluenesulfonate triphenylmethyl, p-toluenesulfonate tri (p-toluyl) methyl, p-toluenesulfonate tri (p-fluorophenyl) methyl, p-
Examples thereof include triphenylmethyl ethylbenzenesulfonate, triphenylmethyl p-methoxybenzenesulfonate, and triphenylmethyl p-fluorobenzenesulfonate.

Next, the photocurable resin composition of the present invention will be described. The photocurable resin composition of the present invention contains the above-mentioned photocationic polymerization initiator (A) of the present invention and the cationic polymerizable compound (B). As the cationically polymerizable compound (B), for example, a compound having an epoxy group,
Examples thereof include styrenes, vinyl compounds, vinyl ethers, spiroorthoesters, bicycloorthoesters, spiroorthocarbonates, oxetanes and lactones. Examples of the compound having an epoxy group include known aromatic epoxy compounds, alicyclic epoxy compounds, and aliphatic epoxy compounds. In addition,
Among these cationically polymerizable compounds (B), compounds having an epoxy group are often used.

Examples of aromatic epoxy compounds that can be used in the present invention include monofunctional epoxy compounds such as phenyl glycidyl ether, and polyhydric phenols having at least one aromatic ring or polyalkylene compounds of alkylene oxide adducts thereof. Glycidyl ether, and more specific examples thereof include bisphenol compounds such as bisphenol A, tetrabromobisphenol A, bisphenol F, and bisphenol S, or alkylene oxides of bisphenol compounds (for example, ethylene oxide, propylene oxide, butylene oxide, etc.). Glycidyl ethers obtained by reacting adducts with epichlorohydrin, phenol novolac type epoxy resins, cresol novolac type epoxy resins, brominated phenol novo Novolak epoxy resins such as click type epoxy resins, and tris-phenol methane triglycidyl ether. Specific examples of the alicyclic epoxy compound include 4-vinylcyclohexene monoepoxide, norbornene monoepoxide, limonene monoepoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, and bis- (3. 4-epoxycyclohexylmethyl) adipate, bis- (2,3-epoxycyclopentyl) ether, 2- (3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexanone-meta-dioxane and the like. be able to. Specific examples of the aliphatic epoxy compound include 1,4-butanediol diglycidyl ether,
1,6-hexanediol diglycidyl ether, 1,
9-nonanediol diglycidyl ether, ethylene glycol diglycidyl ether, ethylene glycol monoglycidyl ether, propylene glycol diglycidyl ether, propylene glycol monoglycidyl ether, diethylene glycol diglycidyl ether,
Triethylene glycol diglycidyl ether, tetraethylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, glycerol diglycidyl ether, glycerol triglycidyl ether, trimethylolpropane diglycidyl ether, trimethylolpropane triglycidyl ether, sorbitol tetraglycidyl ether, Examples thereof include allyl glycidyl ether and 2-ethylhexyl glycidyl ether.

Specific examples of styrenes that can be used in the present invention include styrene, α-methylstyrene, p-methylstyrene, p-chloromethylstyrene and the like. Specific examples of the vinyl compound include N-vinylcarbazole and N-vinylpyrrolidone.

Specific examples of vinyl ethers that can be used in the present invention include, for example, n-butyl vinyl ether, isobutyl vinyl ether, tert-butyl vinyl ether, cyclohexyl vinyl ether, ethylene glycol monovinyl ether, ethylene glycol divinyl ether, hydroxybutyl vinyl ether,
1,4-butanediol divinyl ether, triethylene glycol divinyl ether, tetraethylene glycol divinyl ether, propylene glycol divinyl ether, neopentyl glycol divinyl ether,
Glycerol divinyl ether, glycerol trivinyl ether, trimethylolpropane divinyl ether, trimethylolpropane trivinyl ether, sorbitol tetravinyl ether, cyclohexanedimethanol divinyl ether, n-dodecyl vinyl ether, 2,2-bis (4-cyclohexanol) propane divinyl ether, Alkyl vinyl ethers such as 2,2-bis (4-cyclohexanol) trifluoropropane divinyl ether, alkenyl vinyl ethers such as allyl vinyl ether, ethynyl vinyl ether, 1
-Alkynyl vinyl ethers such as methyl-2-propenyl vinyl ether, phenyl vinyl ether, hydroquinone divinyl ether, 4-vinyl ether styrene, p-methoxyphenyl vinyl ether, bisphenol A divinyl ether, tetrabromobisphenol A divinyl ether, bisphenol F divinyl ether, phenoxyethylene Allyl vinyl ethers such as vinyl ether and p-bromophenoxyethylene vinyl ether, aralkyl divinyl ethers such as 1,4-benzenedimethanol divinyl ether, Nm-chlorophenyldiethanolamine divinyl ether, and m-phenylene bis (ethylene glycol) divinyl ether. Etc. can be mentioned.

Specific examples of spiro orthoesters that can be used in the present invention include, for example, 1,4,6-trioxaspiro (4,4) nonane, 2-methyl-1,
4,6-trioxaspiro (4,4) nonane, 1,4
Examples thereof include 6-trioxaspiro (4,5) decane. Specific examples of bicycloorthoesters include, for example, 1-phenyl-4-ethyl-2,6,7-
Examples thereof include trioxabicyclo (2,2,2) octane and 1-ethyl-4-hydroxymethyl-2,6,7-trioxabicyclo (2,2,2) octane.
Specific examples of spiro orthocarbonates include, for example, 1,5,7,11-tetraoxaspiro (5,5)
Undecane, 3,9-dibenzyl-1,5,7,11-
Tetraoxaspiro (5,5) undecane and the like can be mentioned.

Further, examples of the oxetane that can be used in the present invention include oxetane, phenyloxetane, 3,3-dimethyloxetane, 3,3-bis (chloromethyl) oxetane, 2-hydroxymethyloxetane, and 3-methyl. -3-oxetane methanol, 3
-Methyl-3-methoxymethyloxetane, 3-ethyl-3-phenoxymethyloxetane, resorcinol bis (3-methyl-3-oxetanylethyl) ether,
Examples thereof include m-xylylene bis (3-ethyl-oxetanyl ethyl ether). Examples of lactones that can be used in the present invention include β-propiolactone and γ-butyrolactone.

The above-mentioned cationically polymerizable compound (B) used in the present invention may be used alone or in a mixture of two or more kinds.

The proportion of each component constituting the photocurable resin composition of the present invention is such that the cationically polymerizable compound (B) is 100%.
The cationic photopolymerization initiator (A) is usually preferably 0.1 to 10 parts by weight, more preferably 1 to 5 parts by weight, based on parts by weight. Cationic polymerizable compound (B)
When the proportion of the photocationic polymerization initiator (A) used is less than 0.1 part by weight based on 100 parts by weight, the curability after irradiation with active energy rays is deteriorated. On the contrary, when the proportion of the cationic photopolymerization initiator (A) used exceeds 10 parts by weight, crystals of the cationic photopolymerization initiator (A) are precipitated in the photocurable resin composition of the present invention to give a transparent appearance. Or the crystal of the photocationic polymerization initiator (A) is deposited on the surface of the coating film after coating the photocurable resin composition of the present invention, and a flat coating film surface cannot be obtained. Alternatively, the transparency of the cured film is impaired, the performance of the cured film such as water resistance and mechanical properties is deteriorated, and the price of the photocurable resin composition of the present invention is increased, which is not preferable.

By adding a photosensitizer to the photocurable resin composition of the present invention and blending it, the sensitivity to active energy rays can be improved, and the photocurable resin composition having a faster curing speed. It can be a thing. Specific examples of the photosensitizer that can be used here include, for example, naphthalene derivative, anthracene derivative, phenanthrene derivative, naphthacene derivative, chrysene derivative, perylene derivative, pentacene derivative, acridine derivative, benzthiazole derivative, benzoin derivative, fluorene derivative. ,
Naphthoquinone derivative, anthraquinone derivative, xanthene derivative, xanthone derivative, thioxanthene derivative,
Thioxanthone derivative, coumarin derivative, ketocoumarin derivative, cyanine derivative, acridine derivative, azine derivative, thiazine derivative, oxazine derivative, indoline derivative, azulene derivative, triallylmethane derivative, phthalocyanine derivative, spiropyran derivative, spirooxazine derivative, thiospiropyran derivative, organic Examples thereof include ruthenium complexes, and among them, preferred are naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, chrysene derivatives, perylene derivatives, and acridine derivatives, and among them, particularly substituted with an alkyl group having 1 to 4 carbon atoms. May have as a group 9,
10-dialkoxyanthracene derivative or 9,1
0-di (alkoxyalkoxy) anthracene derivatives are preferred.

Specific examples of the 9,10-dialkoxyanthracene derivative or the 9,10-di (alkoxyalkoxy) anthracene derivative which may have an alkyl group having 1 to 4 carbon atoms as a substituent include, for example, 10-
Dimethoxyanthracene, 2-ethyl-9,10-dimethoxyanthracene, 2-tert-butyl-9,10
-Dimethoxyanthracene, 2,3-dimethyl-9,1
0-dimethoxyanthracene, 9,10-diethoxyanthracene, 2-ethyl-9,10-diethoxyanthracene, 2-tert-butyl-9,10-diethoxyanthracene, 2,3-dimethyl-9,10-di Ethoxyanthracene, 9,10-di (n-propoxy) anthracene, 2-ethyl-9,10-di (n-propoxy) anthracene, 9,10-diisopropoxyanthracene, 2-ethyl-9,10-diiso Propoxyanthracene, 9,10-di (2-methoxyethoxy) anthracene, 2-ethyl-9,10-di (2-methoxyethoxy) anthracene, 2-tert-butyl-9,1.
0-di (2-methoxyethoxy) anthracene, 2,3
-Dimethyl-9,10-di (2-methoxyethoxy) anthracene, 9,10-di (n-butoxy) anthracene, 2-ethyl-9,10-di (n-butoxy) anthracene, 9,10-di ( 2-Ethoxyethoxy) anthracene, 2-ethyl-9,10-di (2-ethoxyethoxy) anthracene, 9,10-dibenzyloxyanthracene, 2-ethyl-9,10-dibenzyloxyanthracene, 2-tert- Butyl-9,10-dibenzyloxyanthracene, 2,3-dimethyl-9,10
-Dibenzyloxyanthracene, 9,10-di (2-
Carboxyethoxy) anthracene, 2-ethyl-9,
Examples thereof include 10-di (2-carboxyethoxy) anthracene.

The photocurable resin composition of the present invention further comprises a solvent for dilution or an antifoaming agent, within a range not impairing the curability.
Various additives such as a leveling agent, a thickener, a flame retardant, an antioxidant, a light stabilizer, a filler, an antistatic agent, a flow regulator and a coupling agent can be mixed.

The photocurable resin composition of the present invention can be obtained by uniformly mixing the above-mentioned components in a predetermined ratio, and is easily cured by irradiation with active energy rays such as ultraviolet rays. be able to. For the curing, the photocurable resin composition of the present invention is usually made to have a thickness of about 0.01 to 1 mm and then irradiated with active energy rays. The suitable active energy ray may be any as long as it has the energy to induce the decomposition of the photocationic polymerization initiator, but is preferably a high pressure mercury lamp, a low pressure mercury lamp, a xenon lamp, a metal halide lamp, a germicidal lamp, a laser. Examples thereof include electromagnetic wave energy of light having a wavelength of 2000 to 7,000 angstroms, light energy rays such as electron beams, X-rays, and ultraviolet rays. The irradiation time of the active energy ray depends on its intensity, but usually about 0.1 to 10 seconds is sufficient. However, it is preferable to spend more time for a coating film having a relatively thick film thickness. After 0.1 to several minutes after irradiation with the active energy ray, most of the photocurable resin composition is cured by photocationic polymerization and photoradical polymerization and dried by touch. Depending on the type and blending ratio, the photocurable resin composition may be exposed to active energy rays at 30 to 100 ° C.
By heating to a certain degree, it is possible to effectively promote the polymerization reaction and further improve the curing rate. Further, the cured product obtained by irradiating with active energy rays can be further heat-treated at 50 to 250 ° C. for the purpose of completing the curing by polymerization. In the case of heat treatment, considering the heat resistance of the base material to be coated with the photocurable resin composition and the cured product obtained, when heat treatment is performed at a high temperature of 100 ° C. or higher, the heat treatment should be performed in the shortest possible time. Is preferred.

Specific applications of the photocurable resin composition of the present invention include paints, coating agents, inks, resists, liquid resists, adhesives, molding materials, putties, glass fiber impregnating agents, sealing agents, and optical materials. Examples of the material that can be used as a coating agent include metal, wood, rubber, plastic, glass, and ceramic products.

[0032]

EXAMPLES The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to these examples.

Synthesis Example of Photocationic Polymerization Initiator (A) Example 1: 43.0 g of 25 w% aqueous potassium hydroxide solution was placed in a 100 mL four-necked flask, and 12.0 g of triphenylmethanol was added with stirring. After cooling this solution to 10 to 15 ° C, 11.0 g of p-toluenesulfonic acid chloride was added over 10 hours while paying attention to heat generation. After charging p-toluenesulfonic acid, the reaction solution was stirred at a temperature of 25 ° C. or lower for 48 hours. To this reaction solution, 30 mL of 6N hydrochloric acid was slowly charged while paying attention to the heat generation, and the pH of the reaction solution was adjusted to 5 to 6, and water was added to 15
The reaction solution was poured into 0 mL with stirring, and the mixture was stirred at a temperature of 15 to 20 ° C. for 1 hour. After stirring, cool the reaction mixture to 5-1
After stirring at 0 ° C. for 30 minutes, the precipitated crystals were filtered out and washed with 100 mL of water. Further, the obtained crystals were recrystallized with a mixed solvent of n-hexane and acetone and dried to obtain 12.8 g of the target triphenylmethyl p-toluenesulfonate (yield 67.0%). It was The obtained triphenylmethyl p-toluenesulfonate was a milky white powder and had a melting point of 84 to 86 ° C. The results of elemental analysis of the obtained reaction product are shown in Table 1.

Table 1 Element Measured value (wt%) Calculated value (wt%) C 75.28 75.32 H 5.40 5.36 S 7.77 7.74

Example 2: In the same manner as in Example 1, 25
45.0 g of w% aqueous potassium hydroxide solution, tri (p-toluyl) instead of 12.0 g of triphenylmethanol
By using 14.0 g of methanol, 11.1 g of p-toluenesulfonic acid chloride and 32 mL of 6N hydrochloric acid, 12.9 g of the target tri (p-toluyl) methyl p-toluenesulfonate (yield 61.1%) was obtained. Obtained. The obtained tri (p-toluyl) methyl p-toluenesulfonate was a milky white powder and had a melting point of 63 to 65 ° C.
Met. The results of elemental analysis of the obtained reaction product are shown in Table 2.
Shown in.

Table 2 Element Measured value (wt%) Calculated value (wt%) C 76.25 76.28 H 6.22 6.19 S 7.07 7.02

Example 3: In the same manner as in Example 1, p-
P instead of 11.0 g of toluenesulfonic acid chloride
-By using 11.2 g of fluorobenzenesulfonic acid chloride, the target p-fluorobenzenesulfonic acid triphenylmethyl 12.2 g (yield 63.2)
%) Was obtained. The obtained triphenylmethyl p-fluorobenzenesulfonate was a milky white powder and had a melting point of 74 to 76 ° C. The results of elemental analysis of the obtained reaction product are shown in Table 3.

Table 3 Element Measured value (wt%) Calculated value (wt%) C 71.65 71.74 H 4.70 4.59 S 7.71 7.66

Composition Examples Examples 4 to 6, Comparative Example 1 A resin composition was compounded according to the composition (numerical values are parts by weight) shown in Table 4 and mixed and dissolved. The resin compositions shown in Table 4 were prepared by dissolving 1.5 parts by weight of the photocationic polymerization initiators synthesized in advance in Examples 1 to 3 in 1.5 parts by weight of γ-butyrolactone. It was prepared by blending the compounds and heating and dissolving. Cured films of these blended compositions were obtained by applying the blended compositions prepared according to Table 4 on an aluminum test panel to a thickness of 5 μm and then irradiating them with ultraviolet rays from a distance of 8 cm with a high pressure mercury lamp (80 W / cm). It was The cured film thus obtained was tested for dryness to the touch, transparency, storage stability and gloss of the cured coating film as follows. The test results are also shown in Table 4.

Finger touch dryness: The ultraviolet irradiation dose until the surface is not scratched when touched with a finger or gauze is m.
It is expressed in J / cm ² .

Transparency: The composition was placed in a transparent container such as a test tube and visually evaluated. ○: No turbidity or precipitate.

Storage stability: The resin composition was stored at 40 ° C. for 3 months and the stability was investigated. ○: No change in viscosity and no crystallization.

Gloss of cured coating film: The surface of the cured coating film was visually evaluated after being irradiated with ultraviolet rays until it was dry to the touch. ○: Good gloss.

[0044]                                    Table 4                                                 Example comparison An example                                         4 5 6 1 Product obtained in Example 1 1.5 The product obtained in Example 2 1.5 Product obtained in Example 3 1.5 Triallylsulfonium compound * 1 1. 5 γ-butyrolactone 1.5 1.5 1.5 1.5 1. 5 Celoxide 2021 * 2 80 80 80 8 0 EHPE-3150 * 3 20 20 20 2 0 Touch dryness 55 50 457 5 Transparency ○ ○ ○ ○ Storage stability ○ ○ ○ ○ Gloss ○ ○ ○ ○

Note) * 1 Hexafluorophosphoric acid (4-phenylthiophenyl) diphenylsulfonium * 2 Daicel Chemical Industries, alicyclic epoxy resin * 3 Daicel Chemical Industrial, alicyclic epoxy resin

The hexafluorophosphoric acid used as the triallylsulfonium compound in Comparative Example 1 in Table 4 (4
-Phenylthiophenyl) diphenylsulfonium is
It was synthesized by the following method.

60.6 g of methanesulfonic acid was placed in a 100 mL separable flask, and 9.2 g of diphenyl sulfide and 1 of diphenyl sulfoxide were added with stirring.
0.0 g was added, and the mixture was stirred as it was at 20 ° C. To this mixture, 9.2 g of acetic anhydride was added dropwise at 25 ° C. or lower while paying attention to heat generation. After the entire amount of acetic anhydride was dropped, the mixture was stirred for about 10 minutes as it was, then heated up, and stirred at 50 to 60 ° C. for 5 hours. After cooling the reaction solution to 20 to 25 ° C, 350 mL of water
The mixture was added to the mixture with stirring, and a 25 wt% sodium hydroxide aqueous solution was further added until the pH of the solution became 5 to 7. After neutralization, the aqueous solution obtained by diluting the reaction solution was ice-cooled in a cool dark place and left for 2 hours, and the supernatant was removed by decantation.
500 mL of water was added and stirred to dissolve the residue. After the solution became a uniform light brown transparent solution, 9.8 g of potassium hexafluorophosphate that had been ground in advance was added,
After stirring for 1 hour as it was, the precipitated white crystals were filtered off. The obtained crystals were washed with 1 L of water, and the crystals were recrystallized with ethanol and air-dried for 24 hours.
20.5 g of the target (4-phenylthiophenyl) diphenylsulfonium hexafluorophosphate after vacuum drying at ℃
(Yield 80.4%) was obtained. The obtained (4-phenylthiophenyl) diphenylsulfonium hexafluorophosphate is a white to milky white powder and has a melting point of 116 to 118 ° C.
Met. Table 5 shows the results of elemental analysis of the obtained product.

Table 5 Element Measured value (wt%) Calculated value (wt%) C 55.86 55.79 H 3.78 3.72 S 12.38 12.42

Examples 7 to 9 and Comparative Example 2 Resin compositions were blended according to the blending composition shown in Table 6 (numerical values are parts by weight), mixed and dissolved. The compounding compositions shown in Table 6 were prepared by previously dissolving 3 parts by weight of the cationic photopolymerization initiator in 3 parts by weight of γ-butyrolactone, mixing the cationically polymerizable compound therein, and heating and dissolving the compound. . The cured film of these blended compositions was obtained by applying the blended compositions prepared according to Table 6 to a PET film cut into 70 mm × 60 mm by a bar coater, and irradiating ultraviolet rays from a distance of 8 cm with a high pressure mercury lamp (80 W / cm) at 100 mJ. It was cured by irradiation at a dose of ¹ / cm ² . After the curing, the PET film with the cured film was put into a 100 ml glass vial bottle whose airtightness was sufficiently confirmed so that the film surfaces did not overlap each other, sealed, and then heated in an electric furnace at 110 ° C. After cooling, 1 ml of gas in the vial
It was collected and benzene was quantified by gas chromatography. When quantifying benzene, a certain amount of benzene was analyzed by a gas chromatograph, the concentration of benzene was determined by a calibration curve, and then the detected amount of benzene was expressed in mg per 1 m 2 of the cured film. The test results are also shown in Table 6.

Table 6 Example Comparative Example 7 8 9 2 Product obtained in Example 3 3 Product obtained in Example 2 3 Product obtained in Example 3 3 Triallylsulfonium compound * 4 3 γ-butyrolactone 3 33 3 UVR-6110 * 5 50 50 50 50 50 UVR-6128 * 6 50 50 50 50 Weight of cured film (mg) 60.3 65.4 64.1 62. 2 Content of initiator (mg) 1.71 1.85 1.81 1. 76 Application area (cm ² ) 42 42 42 42 Detected amount of benzene (mg / m ² ) Not detected Not detected Not detected 0. 6

Note) * 4 (4-phenylthiophenyl) diphenylsulfonium hexafluorophosphate, the compound used in Comparative Example 1 in Table 4 above * 5 manufactured by Union Carbide Co., alicyclic epoxy resin * 6 Union Carbide Co. Made, alicyclic epoxy resin

[0052]

The photocationic polymerization initiator obtained in the present invention can be used as a photocationic polymerization initiator when photopolymerizing a cationically polymerizable compound. Also,
The photocurable resin composition containing the photocationic polymerization initiator obtained in the present invention has excellent transparency and storage stability, and can be photocured by irradiation with active energy rays such as ultraviolet rays. Furthermore, the resin composition of the present invention,
It does not liberate benzene when it is cured by irradiation with active energy rays or when heat treatment is performed to obtain a sufficiently cured film.

Claims (6)

[Claims] 1. The following formula (1): (Here, R ₁ is a methyl group, an ethyl group, a methoxy group, an ethoxy group or a fluorine atom, and R ₂ is a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms,
It represents a linear or branched alkoxy group having 1 to 4 carbon atoms or a fluorine atom. ) An aromatic sulfonic acid ester compound represented by: 2. A photocationic polymerization initiator (A) comprising an aromatic sulfonic acid ester compound represented by formula (1) according to claim 1. 3. A photocurable resin composition comprising the cationic photopolymerization initiator (A) according to claim 2 and one or more cationically polymerizable compounds (B). 4. The one or more kinds of cationically polymerizable compounds (B) according to claim 3, wherein at least one kind is a compound having one or more epoxy groups in one molecule. The photocurable resin composition according to claim 3. 5. The content of the photocationic polymerization initiator (A) is
The photocurable resin composition according to claim 2 or 4, wherein the content is 0.1 to 10% by weight with respect to one kind or two or more kinds of cationically polymerizable compounds (B). 6. A cured product obtained by curing the photocurable resin composition according to any one of claims 3 to 5.