JPH10287643A - New onium salt, photopolymerization initiator, energy ray-curable composition containing the same, and cured product of the composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a new compound, excellent in storage stability, compatibility and curability, and useful as an active component for a photopolymerization initiator, which gives an energy ray-curable composition giving little odor. SOLUTION: This onium salt is a compound shown by formula I [X is shown by formula II (Ar2 is a monovalent aromatic group); Ar1 is a monovalent aromatic group; Z is shown by the formula MQp-m (OH)m (M is P, As or Sb; Q is a halogen; (p) is 4 to 6; and (m) is 0 or 1)], e.g. a compound shown by formula III. The compound shown by the formula I is obtained by condensing a diphenyl sulfide-based compound shown by formula IV with a diphenyl sulfoxide compound shown by formula V at room temperature to 150 deg.C in a solvent, e.g. methanesulfonic acid or ethanesulfonic acid in the presence of a dehydration agent (e.g. phosphorus pentaoxide or concentrated sulfuric acid), preferably with mol of the compound shown by the formula V per equivalent of the terminal sulfide group of the compound shown by formula IV, and by dropping the reaction solution obtained above to an aqueous solution of an alkali metal salt shown by the formula MQp-m (OH)m .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel onium salt, a photopolymerization initiator containing the same as an active ingredient, an energy ray-curable composition containing the same, which can be cured by irradiation with energy rays, and a cured product thereof. About.

[0002]

2. Description of the Related Art Photopolymerizable compositions have been actively studied in the fields of printing inks, paints, coatings, liquid resist inks, etc. from the demands of energy saving, space saving, and non-polluting properties, and their practical use has been studied. . However, most of these studies were based on radical polymerization reactions of double bonds. Cationic polymerizable substances, such as epoxy resins, are excellent materials in physical properties, but are difficult to photopolymerize. Until now, materials with double bonds introduced by acrylic modification have been mainly used. . As a method of curing an epoxy resin by light, for example, US Pat.
No. 4576 proposes a method using a photosensitive aromatic diazonium salt as a photopolymerization initiator. However, the aromatic diazonium salt releases nitrogen gas by photodecomposition, and when the thickness of the epoxy resin is 15 μm or more, the coating film foams and is not suitable for thick coating. Furthermore,
Further, the mixture of the photosensitive aromatic diazonium salt and the epoxy resin has a problem in storage stability such that curing gradually proceeds even in the absence of light, and cannot be a one-part composition.

[0003]

Various studies have been made to overcome the above-mentioned drawbacks of the diazonium salt-based photopolymerization initiator, and aromatic sulfonium salts and aromatics have been proposed as techniques for improving thick coating properties and storage stability. Group iodonium salt initiators and curable resin compositions containing them are disclosed in
JP-A-14278, JP-B-52-14277, JP-A-54-53181, JP-B-59-19581.
No. 6,009,036. However, compositions containing these aromatic onium salts have the disadvantage of being less curable than diazonium salts, and in the case of aromatic sulfonium salts, the odor of the cured product has been a problem.
In order to overcome such a drawback, an aromatic sulfonium salt having a specific group is proposed in JP-A-56-55420 and the like. However, the above disadvantages are somewhat satisfactory but not sufficient. Also, as the field of use of the photopolymerizable composition has expanded, the development of a novel photopolymerization initiator to meet market requirements has become an important technical issue.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, obtained a novel onium salt. By using the same, storage stability and compatibility (particularly various vinyl ethers) were obtained. It has been found that an energy ray-curable composition having excellent curability and a low odor of the cured product can be obtained, thereby completing the present invention. That is,
The present invention provides (1) an onium salt represented by the following formula (1):

[0005]

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(In the formula (1), X represents a group represented by the formula (2).

[0007]

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However, in equations (1) and (2), A
r ₁ and Ar ₂ each represent a monovalent aromatic group. Z is the equation (3)

[0009]

Embedded image MQ _pm (OH) _m (3)

(In the formula (3), M is a phosphorus atom, an arsenic atom or an antimony atom, Q is a halogen atom, P is an integer of 4 to 6, and m is an integer of 0 or 1. .) Or equation (4)

[0011]

Embedded image BYaRb (4)

(In the formula (4), B is a boron atom, a and b
Is an integer from 0 to 4, where a + b is 4, Y
Represents a halogen atom or a hydroxyl group, and R represents a phenyl group substituted with at least one electron-withdrawing group or at least two halogen atoms. ) Represents an anion. (2) Ar ₁ and Ar ₂ are each

[0013]

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(These aromatic groups include (C ₁ -C ₂₀ ) alkyl groups, (C ₁ -C ₁₀ ) alkyloxycarbonyl groups, (C ₁ -C ₁₀ ) alkylcarbonyloxy groups, benzoyl groups, cyano groups , A nitro group, a (C ₁ -C ₂₀ ) alkoxy group, or a halogen atom, which may have one or more groups selected as a substituent.) (3) a photopolymerization initiator containing the onium salt of (1) or (2) as an active ingredient; and (4) an energy ray-curable composition containing a cationically polymerizable substance and the onium salt of (1) or (2). The composition according to (4), wherein the cationic polymerizable substance is an epoxy compound, a vinyl ether compound or a cyclic ether compound,
(6) The composition according to claim 5, wherein the epoxy compound is an alicyclic epoxy resin, and (7) the vinyl ether compound is triethylene glycol divinyl ether, tetraethylene glycol divinyl ether, cyclohexane-1,4.
-The composition of the above (5), which is dimethylol divinyl ether, 1,4-butanediol divinyl ether, polyester polyvinyl ether or urethane polyvinyl ether, (8) a cured product of the composition of the above (4) to (7),
(9) A method for curing the composition according to (4) to (7), wherein the composition is irradiated with an energy ray.
The invention relates to the curing method according to the above (9), wherein the energy ray is an ultraviolet ray or an electron beam.

The present invention will be described in detail. General formula (1),
Examples of the monovalent aromatic group represented by Ar ₁ and Ar ₂ in (2) include, for example,

[0016]

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And the like. Incidentally, these aromatic groups, methyl group, ethyl group, propyl group, butyl group, octyl group, an alkyl group of nonyl group _{C 1 ~C 20, (C 1} ~
C ₁₀₎ alkyl carbonyloxy group, a fluorine atom, a chlorine atom, a bromine atom, a halogen atom such as iodine atom, (C ₁
To C ₁₀ ) alkyloxysilbonyl groups, (C _{1 to} C ₂₀ )
It may have one or more substituents such as an alkoxy group, a benzoyl group, a cyano group and a nitro group.

The onium salt of the present invention is obtained by using a compound represented by the formula (5)

[0019]

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[0020] (Equation (5) in, Ar ₁ is the general formula (1) represents the same meaning as Ar ₁ in.) And diphenyl sulfide compound represented by the formula (6)

[0021]

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The method of using (in the formula (6), Ar ₂ is formula (2) represents. The same meaning as Ar ₂ in) the known production reaction of the sulfonium salt from the diphenyl sulfoxide compound represented by Can be synthesized by To explain the synthesis example specifically, the diphenyl sulfide compound represented by the formula (5) and the diphenyl sulphoxide compound represented by the formula (6) are preferably used in an amount of about 1 to 1 equivalent of the former terminal sulfide group. Methanesulfonic acid, ethanesulfonic acid, and the like, using a known method such as a dehydrating agent (eg, phosphorus pentoxide, concentrated sulfuric acid, acetic anhydride, etc.)
Room temperature to 1 in a solvent such as perfluoromethanesulfonic acid.
The condensation reaction may be performed at 50 ° C., and then these reaction solutions may be added dropwise to an alkali metal salt of a compound represented by the above formula (3) or (4), or an aqueous solution. Alternatively, the diphenyl sulfide-based compound represented by the formula (5) is partially oxidized in a suitable solvent (for example, acetic acid, acetic anhydride, sulfuric acid, methanesulfonic acid, etc.) to give a reaction solution,
A method in which the diphenyl sulfide compound and the diphenyl sulphoxide compound are present in about equimolar amounts and then the condensation reaction is carried out is also possible. At this time, as the oxidizing agent, a normal oxidizing agent such as hydrogen peroxide, potassium permanganate, nitric acid, sodium metaperiodate, iodobenzene diacetate, or the like is used. The reaction temperature is 0 to 100 ° C,
Preferably, it is performed at 30 to 60 ° C.

Specific examples of the compound represented by the formula (5) include the following compounds.

[0024]

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Specific examples of the compound represented by the formula (6) include, for example, 4-phenylcarbonyldiphenylsulfoxide, 4- (p-fluorophenylcarbonyl) diphenylsulfoxide, 4- (p-chlorophenylcarbonyl) diphenylsulfoxide , 4- (o-methoxyphenylcarbonyl) diphenylsulfoxide, 4-
(P-ter-butylphenylcarbonyl) diphenylsulfoxide, 4- (m-nitrophenylcarbonyl)
Examples include diphenyloxide, 4- (naphthalene-2-carbonyl) diphenylsulfoxide, 4- (p-diphenylcarbonyl) diphenylsulfoxide and the like.

Specific examples of the alkali metal salts of the compounds represented by the above formulas (3) and (4) include, for example, NaS
bF ₆ , NaPF ₆ , NaBF ₄ , NaSbF ₅ OH,
KSbF ₆ , KPF ₆ , KAsF ₆ , KSbF ₅ OH,
LiB (C ₆ F ₅ ) ₄ , LiB (C ₆ F ₅ ) ₂ F ₂ , L
iB (C ₆ F ₄ CF ₃ ) ₄ , NaB (C ₆ F ₅ ) ₄ , L
iBF ₃ (C ₆ F ₅ ), LiB (C ₆ H ₃ F ₂ ) _{4 and the} like can be given.

The compound represented by the formula (5) can be obtained by reacting an aromatic monocarboxylic acid compound with diphenyl sulfide. At this time, it is preferable to use a solution in which phosphoric anhydride is dissolved in an alkylsulfonic acid (for example, methanesulfonic acid, ethanesulfonic acid, perfluoromethanesulfonic acid, or the like) as a reaction solvent. C is preferred. The reaction time is 0.
5 to 15 hours are preferred. As for the use ratio of the aromatic monocarboxylic acid compound and diphenyl sulfide, it is preferable to react diphenyl sulfide at about 1 mole ratio with respect to 1 mole of the aromatic monocarboxylic acid compound.

Specific examples of the aromatic monocarboxylic acid compound include, for example, benzoic acid, o-methyl-benzoic acid, m-methyl-benzoic acid, p-methyl-benzoic acid, 3,5-dimethyl-benzoic acid, -Ethyl-benzoic acid, p-ter-
Butylbenzoic acid, p-octyl-benzoic acid, o-methylcarbonyloxy-benzoic acid, p-methyloxycarbonyl-benzoic acid, o-chlorobenzoic acid, m-chlorobenzoic acid, p-chlorobenzoic acid, 2,4 -Dichlorobenzoic acid, o-fluorobenzoic acid, m-fluorobenzoic acid,
2,4-difluorobenzoic acid, p-methoxybenzoic acid,
p-butoxybenzoic acid, o-benzoylbenzoic acid, p-
Examples include phenylbenzoic acid, m-phenylbenzoic acid, o-phenylbenzoic acid, naphthalene-2-carboxylic acid, naphthalene-1-carboxylic acid, p-cyanobenzoic acid, and o-cyanobenzoic acid.

Specific examples of the compound represented by the general formula (1) include the compounds shown in the following Table 1, but are not limited thereto.

[0030]

[Table 1]

Next, the energy ray-curable composition of the present invention will be described. Specific examples of the cationically polymerizable substance used in the composition of the present invention include, for example, epoxy compounds, vinyl ether compounds, and cyclic ether compounds (preferably spiro ortho esters, bicyclo ortho esters, spiro ortho carbonates). Such as spiro compounds and oxetane compounds). Examples of the epoxy compound include known aromatic epoxy resins, alicyclic epoxy resins, aliphatic epoxy resins, epoxy monomers, and episulfide monomers.

Here, a specific example of the aromatic epoxy resin is a polyglycidyl ether of a polyhydric phenol having at least one aromatic nucleus or an alkylene oxide adduct thereof, such as bisphenol A,
Glycidyl ethers and novolak epoxy resins (for example, produced by reacting bisphenol compounds such as bisphenol F and bisphenol S or alkylene oxide (eg, ethylene oxide, propylene oxide, butylene oxide, etc.) adducts of bisphenol compounds with epichlorohydrin) Phenol / novolak epoxy resin, cresol / novolak epoxy resin, brominated phenol / novolak epoxy resin, etc.), and trisphenol methane triglycidyl ether.

Specific examples of the alicyclic epoxy resin include 2,4-epoxycyclohexylmethyl-3,4-
Epoxy cyclohexane carboxylate, bis-
(3,4-epoxycyclohexylmethyl) adipate, 2- (3,4-epoxycyclohexyl-5,5-
(Spiro 3,4-epoxy) cyclohexanone-meta-
Dioxane, bis (2,3-epoxycyclopentyl)
Ether, EHPE-3150 (manufactured by Daicel Chemical Industries, Ltd., alicyclic epoxy resin, softening point 71 ° C.), epoxidized polybutanediene, and the like.

Further, specific examples of the aliphatic epoxy resin include polyglycidyl ether of an aliphatic polyhydric alcohol or an alkylene oxide adduct thereof, and typical examples thereof include diglycidyl ether of 1,4-butanediol, Diglycidyl ether of 1,6-hexanediol, triglycidyl ether of glycerin, triglycidyl ether of trimethylolpropane, diglycidyl ether of polyethylene glycol, diglycidyl ether of propylene glycol, ethylene glycol,
Polyglycidyl ethers of polyether polyols obtained by adding one or more alkylene oxides (eg, ethylene oxide, propylene oxide, etc.) to aliphatic polyhydric alcohols such as propylene glycol and glycerin are exemplified. Further, examples of the epoxide monomers include monoglycidyl ethers of aliphatic higher alcohols, phenol, cresol, butylphenol, and monoglycidyl ethers of polyether alcohols obtained by adding alkylene oxide thereto. Examples of the vinyl ether compound include triethylene glycol divinyl ether, tetraethylene glycol divinyl ether, trimethylolpropane trivinyl ether, cyclohexane-1,4-dimethylol divinyl ether, 1,4-butanediol divinyl ether, polyester divinyl ether and Urethane polyvinyl ether (for example, V manufactured by ALLIED-S / GNAL, V
Ectomer 2010). These cationically polymerizable substances are used alone or as a mixture of two or more.

The energy ray-curable composition of the present invention comprises:
0.01 to 2 parts per 100 parts by weight of the cationically polymerizable substance
0 parts by weight, more preferably 0.1 to 10 parts by weight of a photopolymerization initiator containing an onium salt represented by the above formula (1) as an active ingredient is contained as an essential component. The nature of the cationically polymerizable substance and the type of energy ray,
It is determined by considering various factors such as the irradiation dose, desired curing time, temperature, humidity, and coating film thickness. To facilitate dissolution of the photopolymerization initiator in the cationically polymerizable substance, the photopolymerization initiator must be dissolved in a solvent (for example, propylene carbonate, carbitol, carbitol acetate, γ-butyrolactone, etc.) before use. Can also. The energy ray-curable composition of the present invention can be prepared by mixing a cationically polymerizable substance and a photopolymerization initiator by a method such as mixing, dissolving or kneading.

The curable composition of the present invention can be cured to a touch-dry state or a solvent-insoluble state after 0.1 seconds to several minutes by irradiating energy rays such as ultraviolet rays. The energy ray may be any as long as it has an energy that induces the decomposition of the photopolymerization initiator, but may be a high or low pressure mercury lamp, a xenon lamp, a germicidal lamp, 2000 angstrom obtained from a laser beam or the like.
It is preferable to use an electromagnetic wave energy ray having a wavelength of 7000 angstroms, or an electromagnetic wave energy ray (high energy ray) such as an electron beam, X-ray, or radiation, and ultraviolet rays are more preferable. Exposure to an energy ray depends on the intensity of the energy ray, but usually about 0.1 to 10 seconds is sufficient. However, it is preferred to spend more time for relatively thick coatings. After 0.1 seconds to several minutes after the irradiation with the energy beam, most of the compositions are touch-dried by cation polymerization. However, in some cases, it is also preferable to heat the composition in order to accelerate the cation polymerization reaction.

The composition of the present invention may further contain a solvent for dilution, a non-reactive resin for modification, or a (meth) acrylate compound (for example, bisphenol A) as long as the cationic polymerization is not impaired. Oligomers such as epoxy (meth) acrylate, urethane (meth) acrylate, and polyester poly (meth) acrylate, which are reaction products of epoxy resins such as epoxy resins such as epoxy resins and novolak epoxy resins, and (meth) acrylic acid; (Meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate and other monomers) Can be blended. When a (meth) acrylate compound is used, it is preferable to use a photoradical polymerization initiator (for example, 1-hydroxycyclohexyl phenyl ketone, acetophenone dimethyl ketal, benzoyl methyl ether, etc.) in combination. Further, for example, an organic carboxylic acid or an acid anhydride can be used for the purpose of improving electric characteristics, or a polyol or other flexible prepolymer can be mixed for the purpose of imparting rubber elasticity.

The composition of the present invention is applied mainly to the surface of an article, for example, from 1 μm to 200 μm, preferably from 3 μm to 50 μm.
It is usually applied as a transparent liquid, but depending on the application, it may be inert pigments, dyes, fillers, antistatic agents, flame retardants, defoamers, flow regulators, Sensitizers, accelerators, light stabilizers and the like are used as a mixture. The energy ray-curable composition of the present invention can be used for metal, wood, rubber, plastic, glass, ceramic products and the like. Specific uses of the composition of the present invention include paints, coating agents, Examples include inks, resists, liquid resists, inks, adhesives, molding materials, casting materials, putties, glass fiber impregnating agents, fillers, and the like.

[0039]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. Parts in Synthesis Examples and Examples are parts by weight.

(Synthesis Example of Diphenyl Sulfide Compound Represented by Formula (5)) Synthesis Example 1 (Synthesis of Compound of Formula (i)) Methanesulfonic acid
7 parts and phosphorus pentoxide (16.2 parts) were uniformly dissolved, and diphenyl sulfide (18.6 parts) and benzoic acid (12.2 parts) were added thereto, and the mixture was reacted at 80 ° C for 1 hour. After confirming that the reaction was completed, 1000 parts of an aqueous potassium hydroxide solution (800 parts of water) was added.
In which 200 parts of potassium hydroxide is dissolved. ), The precipitate was filtered off and dried, and then dissolved in 400 parts of ethanol by heating (60 ° C). After cooling to 5 ° C, the precipitate was filtered off and dried to give a white solid (4- 20.3 parts of phenylcarbonyldiphenylsulfide) were obtained. The melting point of the product was 69-70 ° C.

Synthesis Example 2 180.3 parts of methanesulfonic acid and 18.3 parts of phosphorus pentoxide were uniformly dissolved, and 18.6 parts of diphenyl sulfide was added thereto.
And 13.6 parts of p-methylbenzoic acid were charged and reacted at 80 ° C. for 1 hour, and it was confirmed that the reaction was completed by liquid chromatography.
The same treatment as described above was performed to obtain 20.2 parts of a white solid (4- (p-methylphenylcarbonyl) diphenyl sulfide). The melting point of the product was 117-118 ° C.

Synthesis Example 3 208.2 parts of methanesulfonic acid and 20.8 parts of phosphorus pentoxide were uniformly dissolved, and 18.6 parts of diphenyl sulfide was added thereto.
And 15.7 parts of p-chlorobenzoic acid were charged and reacted at 80 ° C. for 1 hour, and it was confirmed that the reaction was completed by liquid chromatography.
The same treatment as described above was performed to obtain 21.6 parts of a white solid (4- (p-chlorophenylcarbonyl) diphenyl sulfide). The melting point of the product was 134-135 ° C.

Example 1 29 parts of the compound (4-phenylcarbonyldiphenyl sulfide) obtained in Synthesis Example 1, 150 parts of acetic anhydride and 1 part of sodium tungstate dihydrate were charged, and stirred at 50 to 70 ° C. for 35 parts. 5.7 parts of hydrogen peroxide were added dropwise, and the mixture was further reacted for 2 hours to partially oxidize the compound obtained in Synthesis Example 1. In the reaction solution, 4-phenylcarbonyldiphenylsulfide and 4-phenylcarbonyldiphenylsulfoxide were almost equimolar. And then charged with 200 parts of methanesulfonic acid, heated to 80 ° C. and reacted with stirring for 3 hours, and then, while stirring, the reaction mixture was stirred and stirred with 258.7 parts of a 5% aqueous solution of NaSbF ₆ 258.7 parts. , And the precipitated white solid was filtered, washed with methanol, and dried to obtain 35 parts of a white solid. The melting point of the product was 83-86 ° C, and the result of elemental analysis almost coincided with the calculated value.

Element Actual value (% by weight) Calculated value (% by weight) Carbon 55.89 55.97 Hydrogen 3.40 3.34 Sulfur 7.82 7.86 Antimony 14.75 14.93 Fluorine 13.86 13. 98 This gives the product with the structural formula

[0045]

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It was confirmed that the onium salt was represented by the following formula:

Example 2 30.4 parts of the compound (4- (p-methylphenylcarbonyl) diphenyl sulfide) obtained in Synthesis Example 2, 150 parts of acetic anhydride and 1 part of sodium tungstate dihydrate were charged, and 50 While stirring at 70 ° C., 5.7 parts of 35% hydrogen peroxide solution was added dropwise, and the mixture was further reacted for 2 hours to partially oxidize the compound obtained in Synthesis Example 2. Then, methanesulfonic acid 2 was added.
Then, the mixture was heated to 80 ° C., and reacted for 3 hours while stirring. Then, while stirring, the reaction mixture was gradually added dropwise to 258.7 parts of a 5% aqueous solution of NaSbF ₆ while stirring to precipitate white. The solid was filtered, then washed with methanol and dried to obtain 35.8 parts of a white solid. The melting point of the product was 133 to 135 ° C., and the result of elemental analysis almost coincided with the calculated value.

Element Actual measured value (% by weight) Calculated value (% by weight) Carbon 56.89 56.95 Hydrogen 3.81 3.70 Sulfur 7.62 7.60 Antimony 14.35 14.43 Fluorine 13.42 13. 51 This gives the product of structural formula

[0049]

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It was confirmed that the compound was an onium salt represented by the following formula:

Example 3 32.5 parts of the compound (4- (p-chlorophenylcarbonyl) diphenyl sulfide) obtained in Synthesis Example 3, 150 parts of acetic anhydride and 1 part of sodium tungstate dihydrate were charged, and 50-70 While stirring at ℃, 5.7 parts of 35% hydrogen peroxide solution was added dropwise, and the mixture was further reacted for 2 hours to partially oxidize the compound obtained in Synthesis Example 3, and then methanesulfonic acid 2
The mixture was heated to 80 ° C., and reacted for 3 hours while stirring. Then, while stirring, the reaction mixture was added dropwise little by little to 167.9 parts of a 5% aqueous solution of NaPF ₆ to precipitate white. The solid was filtered, washed with methanol and dried to obtain 34.1 parts of a white solid. The melting point of the product was 152 to 155 ° C., and the result of elemental analysis almost coincided with the calculated value. Element Actual measured value (% by weight) Calculated value (% by weight) Carbon 57.42 57.51 Hydrogen 3.09 3.17 Sulfur 8.03 8.08 Phosphorus 3.88 3.90 Fluorine 14.35 14.36 Chlorine 8 .85 8.93 The resulting product has the structural formula

[0052]

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It was confirmed that the compound was an onium salt represented by the following formula:

Examples 4 to 9 and Comparative Examples 1 to 6 The respective components were blended, mixed and dissolved in accordance with the blending compositions (the numerical values are parts by weight) shown in Table 2 to obtain the present invention and the comparative energy-curable compositions for comparison. I got something. These were applied on an aluminum test panel to a thickness of 5 μm, and a high-pressure mercury lamp (80 w / c
m), ultraviolet light was irradiated from a distance of 8 cm to cure.
Transparency, storage stability, touch dryness of the prepared composition,
The cured coating film was tested for gloss and odor. Table 2 shows the results.

(Test Method) Transparency: The transparency of the composition was visually determined. ○ ・ ・ ・ Completely transparent △ ・ ・ ・ Slightly dirty × ・ ・ ・ ・ White dull XX ・ ・ ・ ・ Separate immediately Storage stability: The composition was 3% at 40 ° C. Stored for months and tested for stability. ○ ・ ・ ・ No change at all △ ・ ・ ・ ・ Slightly thickened × ・ ・ ・ ・ Gelled Touch dryness: Irradiation dose until touch dry (mJ / c)
m ² ) was measured. Mitsawa: After irradiating ultraviolet rays until the touch was dried, the surface of the cured coating film was visually judged. ○ ・ ・ ・ Good gloss △ ・ ・ ・ Slightly cloudy × ・ ・ ・ No gloss Odor: After irradiating the coated surface with 1000 mJ / cm ² , the odor on the surface of the cured coating film was reduced. Observed. ○ ・ ・ ・ No odor △ ・ ・ ・ ・ Slight odor × ・ ・ ・ ・ Odor XX ・ ・ ・ ・ High odor

[0056]

Table 2 (1) Example 4 5 6 7 8 9 Composition Photopolymerization initiator obtained in Example 1 1.5 1.0 Photopolymerization initiator obtained in Example 2 1.5 1.0 Photopolymerization obtained in Example 3 Initiator 1.5 1.0 Celloxide 2021 * 4 80 80 80 EHPE-3150 * 5 20 20 20 VEctomer 2010 * 6 25 25 25 VEctomer 4020 * 7 25 25 25 Triethylene glycol divinyl ether 10 10 10 Physical properties Transparency ○ ○ ○ ○ ○ ○ Storage stability ○ ○ ○ ○ ○ ○ Dry to the touch (mJ / cm ² ) 23 23 75 12 12 23 Gloss ○ ○ ○ ○ ○ ○ Odor ○ ○ ○ ○ ○ ○ ○ Table 2 (2) Comparative Example 1 2 3 4 5 6 Composition Compound 1 * 1 1.5 1.0 Compound 2 * 2 1.5 1.0 Compound 3 * 3 1.5 1.0 Celloxide 2021 * 480 80 80 80 EHPE-3150 * 5 20 20 20 VEctomer2010 * 625 5 25 VEctomer4020 * 7 25 25 25 Triethylene glycol divinyl ether 10 10 10 Properties Transparency ○ ○ ○ ○ × × storage stability ○ ○ ○ ○ ○ ○ dry tack ^{(mJ / cm 2) 140 75} 75 34 23 23 Gloss ○ ○ ○ × × × Odor △ △ ○ △ △ ○

(Note) * 1 Compound 1: triphenylsulfonium hexafluorophosphate * 2 Compound 2: diphenyl-4-thiophenone xyphenylsulfonium hexafluorophosphate * 3 Compound 3: 4,4'-bis [bis (p- 2-
[Hydroxyethoxyphenyl) sulfonio] phenylsulfide hexafluorophosphate * 4 Celloxide 2021: an alicyclic epoxy resin manufactured by Daicel Chemical Industries, Ltd. * 5 EHPE-3150: alicyclic epoxy resin manufactured by Daicel Chemical Industries, Ltd. * 6 VEtomer 2010: aromatic urethane vinyl ether (manufactured by ALLIED-SIGNAL) * 7 VEtomer 4020: aliphatic ester vinyl ether having the following structural formula (ALLIED-SIG
NAL)

[0058]

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As is clear from the results in Table 2, the energy ray-curable composition containing the photopolymerization initiator of the present invention was
It has excellent compatibility, is transparent and has excellent curability, has good gloss of the cured coating film, and has low odor of the cured coating film.

[0060]

The energy ray-curable composition containing the photopolymerization initiator of the present invention has excellent compatibility, is transparent and excellent in curability, and has a high gloss of the cured film obtained. It gives a cured product with low odor and excellent physical properties with good adhesion to metal.

Claims (10)

[Claims] An onium salt represented by the following formula (1): (In the formula (1), X represents a group represented by the formula (2). However, in the formulas (1) and (2), Ar ₁ and Ar
₂ represents a monovalent aromatic group. Also, Z
Is a formula (3) embedded image MQ _pm (OH) _m (3) (in the formula (3), M is a phosphorus atom, an arsenic atom or an antimony atom, Q is a halogen atom, and P is 6
And m is an integer of 0 or 1. Or a formula (4): BYaRb (4) (In the formula (4), B is a boron atom, a and b are integers from 0 to 4, where a + b is 4 and Y is a halogen atom. Alternatively, R represents a hydroxyl group, and R represents a phenyl group substituted with at least one electron-withdrawing group or at least two halogen atoms.) )
2. Ar ₁ and Ar ₂ are each represented by the formula: (These aromatic groups are (C ₁ -C ₂₀ ) alkyl groups,
(C ₁ ~C ₁₀₎ alkyloxycarbonyl group, (C ₁ ~
C ₁₀₎ alkyl carbonyloxy group, a benzoyl group, a cyano group, a nitro group, (C ₁ -C ₂₀₎ alkoxy group, one or more groups selected from the group consisting of halogen atoms which may have a substituent . )). 3. A photopolymerization initiator comprising the onium salt of claim 1 or 2 as an active ingredient. 4. An energy ray-curable composition comprising a cationically polymerizable substance and the onium salt according to claim 1 or 2, 5. The method according to claim 1, wherein the cationically polymerizable substance is an epoxy compound,
The composition according to claim 4, which is a vinyl ether compound or a cyclic ether compound. 6. The composition according to claim 5, wherein the epoxy compound is an alicyclic epoxy resin. 7. The vinyl ether compound is triethylene glycol divinyl ether, tetraethylene glycol divinyl ether, cyclohexane-1,4-dimethylol divinyl ether, 1,4-butanediol divinyl ether, polyester polyvinyl ether or urethane polyvinyl ether. The composition of claim 5. 8. A cured product of the composition according to claim 4. 9. A method for curing a composition according to claim 4, wherein the composition is irradiated with an energy ray. 10. The curing method according to claim 9, wherein the energy ray is an ultraviolet ray or an electron beam.