JPH09255707A - Curable composition and method of curing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a curable composition which cures in a short time even when it contains a pigment and an additive, a filler, etc., having high hiding power or even when it is thick, and which is excellent in shelf stability and suitable for a putty by blending an ethylenically unsaturated polymerizable compound, a filler and a specified polymerization initiator. SOLUTION: This composition contains an ethylenically unsaturated polymerizable compound (e.g. unsaturated polyester resin), an inorganic filler and/or an organic filler, and a polymerization initiator comprising a combination of a hexaarylbiimidazole compound and a hydrogen donor. An example of a hydrogen donor used is an aromatic thiol compound such as 2- mercaptobenzothiazole. The weight ratio of the hexaarylbiimidazole compound to the hydrogen donor is preferably (20:1) to (1:30), although it is arbitrary. After the composition is filled, it is cured by irradiation with a light containing a wavelength at which the initiator is sensitive and by heating.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel curable composition and a method for curing the same. More specifically, it can be cured in a short time even if it contains pigments and additives, fillers, dyes, etc. with high concealment ratio, and it is thick and does not have good light transmittance, and it is stable in storage. TECHNICAL FIELD The present invention relates to a curable composition suitable for a putty material having excellent properties, and a curing method by light irradiation and heating thereof.

[0002]

2. Description of the Related Art Conventionally, a two-part putty material has been used for the purpose of repairing automobiles, sealing seams of building materials, or filling irregularities of car body outer panels during the coating process of railway vehicles to improve the appearance. Has been. For example, a radical curable resin such as an unsaturated polyester resin is cured using a curing agent such as a peroxide, but since it is a two-part type, it takes time to weigh it, forget to add the curing agent, and after mixing the two parts. There were problems such as the limitation of working time and the disposal of unused mixture, and improvements were expected.

As a method for solving these problems, a one-component putty material has been developed. For example,
In 30690, application of ultraviolet light curing is examined, but when the thickness of the cured product is large, or when an additive such as a pigment having a high concealment ratio is contained, the ultraviolet light transmittance is low, and thus ultraviolet light is not transmitted. Has a problem that it does not reach the inside of the curing system sufficiently and the curing inside the curing system is insufficient.

Further, in order to solve the problem of ultraviolet light curing, a method using a visible light polymerization initiator and a thermal polymerization initiator such as 2,2'-azobisisobutyronitrile or benzoyl peroxide together (Japanese Patent Application No. 6-222678), or a method of combining a dye having a photosensitivity in the near infrared with a boron salt (Japanese Patent Application No. 7-322480). However, all putty materials using these polymerization initiators have a problem that the storage period thereof is as short as 2-3 months or less.

[0005]

DISCLOSURE OF THE INVENTION The present invention is directed to a novel curable composition and a method for curing the same, and more specifically, to the problems of conventional two-component putty materials such as the trouble of weighing, forgetting to add the curing agent, and the two-component composition. Limitation of working time after mixing, problem of waste of mixture, light transmission of UV light curing type one-part putty material, safety of light source, etc., as well as visible and near red light curing type putty material. An object of the present invention is to provide a curable composition suitable for a novel putty material and a method for curing the same, which solves problems such as storage stability.

[0006]

Means for Solving the Problems As a result of repeated studies by the present inventors to solve the above problems, (A) a polymerizable compound having an ethylenically unsaturated group (B) an inorganic filler and / or an organic compound Filler (C) Curable composition containing a polymerization initiator of a combination of a hexaarylbiimidazole compound and a hydrogen donor (aromatic thiol compound), and

(A) Polymerizable compound having an ethylenically unsaturated group (B) Inorganic filler and / or organic filler (C) Polymerization of combination of hexaarylbiimidazole compound and hydrogen donor (aromatic thiol compound) A method for curing a curable composition, which comprises filling a curable composition containing an initiator, then irradiating with light having a photosensitive wavelength of a polymerization initiator in the composition, and heating By doing so, the above object was achieved.

The putty material in the present invention is used to enhance the appearance such as for vehicles, or to improve the sealing property such as fillers used for repairing automobiles, building materials, glass, etc. Represents a filler. For details, for example, see the section "Pate" in the Illustrated Plastics Glossary (published by Nikkan Kogyo Shimbun, June 30, 1988, first edition, 7 prints).

A feature of the photopolymerization initiator used in the present invention is the combined use of a hydrogen donor with a hexaarylbiimidazole compound represented by the following general formula (1). These initiators are more sensitive to light in the long wavelength region (visible light region of 400 nm or more) than conventional ultraviolet polymerization initiators and are excellent in light transmittance.

The hexaarylbiimidazole compound used in the present invention is a compound represented by the general formula (1).

General formula (1):

Embedded image (In the formula, L ₁ , L ₂ and L ₃ each independently represent an aryl group or a substituted aryl group.)

Specific examples of the hexaarylbiimidazole compound include bis (2,4,5-triphenyl) imidazole, bis (2-o-chlorophenyl-4,5-diphenyl) imidazole and bis (2-o, p). -Dichlorophenyl-4,5-diphenyl) imidazole, bis (2-o-bromophenyl-4,5-diphenyl) imidazole and the like. Details of the hexaarylbiimidazole compound are described in JP-B-41-3545.

The hydrogen donor used in the present invention is a compound which, as a result, donates a hydrogen radical to the triarylimidazolyl radical produced by the cleavage of the hexaarylbiimidazole to produce a radical effective for radical polymerization. Say. Specific examples of this hydrogen donor include aromatic thiol compounds such as 2-mercaptobenzothiazole, 2-mercaptochlorobenzothiazole, 2-mercaptobenzimidazole, 2-mercaptomethylbenzimidazole and 2-mercaptobenzoxazole. Can be mentioned.

The ratio of the hexaarylbiimidazole compound to the hydrogen donor is arbitrary, but 20/1 to 1/30
The range of (weight ratio) is preferably, and more preferably 5 /
It is in the range of 1 to 1/20.

The amount of the hexaarylbiimidazole compound and the hydrogen donor combined is the polymerizable component 10
0.01 to 35 parts by weight with respect to 0 parts by weight, preferably
It is 0.05 to 25 parts by weight. The total amount of the hexaarylbiimidazole compound and the hydrogen donor used is 0.01
If it is less than 35 parts by weight, the polymerization tends to be insufficient, and if it exceeds 35 parts by weight, the hardness of the cured product may be insufficient.

Polymerization initiators obtained by combining these hexaarylbiimidazole compounds and hydrogen donors are 2
Not only is it a photopolymerization initiator that is sensitive to light containing a wavelength region of 00 to 500 nm,
It was found that by heating above, it acts as a thermal polymerization initiator and is extremely stable in the composition at room temperature. Therefore, the curable composition of the present invention has unprecedented storage stability and maintains sufficient curability even after 6 months or more.

The essential wavelength of light used in the present invention is 40
It is a wavelength region of 0 to 500 nm. Only light having a wavelength shorter than 400 nm has extremely poor light transmissivity and is not preferable for safety. Further, the light having a wavelength longer than 500 nm alone is not preferable because the hexaarylbiimidazole compound has no photosensitivity.

Representative examples of the polymerizable compound having an ethylenically unsaturated group used in the present invention include unsaturated polyester resins, vinyl ester resins and curable (meth) acrylic resins.

The unsaturated polyester resin may be a product obtained by reacting an acid or its anhydride with an alcohol by a known method.

Specific examples of the acid or its anhydride include phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, adipic acid and the like, saturated polybasic acids having no active unsaturated bond or their anhydrides and fumaric acid. Unsaturated polybasic acid having an active unsaturated bond such as acid, maleic anhydride, maleic acid, and itaconic acid, or an anhydride thereof, and if necessary, benzoic acid, abietic acid, dicyclopentenyl maleic acid half ester And monocarboxylic acids such as Specific examples of alcohols include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 2; -Methyl-
1,3-propanediol, 2,2-dimethyl-1,3
Examples include polyhydric alcohols such as propanediol, cyclohexane-1,4-dimethanol, an ethylene oxide adduct of bisphenol A, and a propylene oxide adduct of bisphenol-A.

The vinyl ester resin is produced by a known method, and is an epoxy (meth) resin obtained by reacting an epoxy resin with (meth) acrylic acid.
Polyester (meta) obtained by reacting an acrylate or a polyester having a terminal carboxyl group obtained from a saturated dicarboxylic acid and / or unsaturated dicarboxylic acid and a polyhydric alcohol with an epoxy compound containing an α, β-unsaturated carboxylic ester group A) acrylate and the like.

Examples of the epoxy resin as a raw material for the vinyl ester resin include bisphenol-A-diglycidyl ether and its high molecular weight homologues, novolac type polyglycidyl ethers and the like.

As the saturated dicarboxylic acid, a dicarboxylic acid having no active unsaturated group, for example, phthalic acid,
Isophthalic acid, terephthalic acid, tetrahydrophthalic acid,
Examples thereof include adipic acid and sebacic acid. Examples of unsaturated dicarboxylic acids include dicarboxylic acids having an active unsaturated group, such as fumaric acid, maleic acid, fumaric anhydride, and itaconic acid.

Further, as the polyhydric alcohol component, for example, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,2-
Butanediol, 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-
1,3-propanediol, cyclohexane-1,4-
Examples thereof include polyhydric alcohols such as dimethanol, an ethylene oxide adduct of bisphenol A, and a propylene oxide adduct of bisphenol A.

A typical example of the epoxy compound containing an α, β-unsaturated carboxylic acid ester group is glycidyl methacrylate.

Examples of the curable acrylic resin include (meth) acrylates such as diethylene glycol diacrylate, 1,6-hexanediol dimethacrylate, trimethylolpropane triacrylate, pentaerythritol trimethacrylate, and pentaerythritol tetraacrylate, and hydroxyalkyl ( A product obtained by reacting acrylic acid and / or methacrylic acid with an adduct of a polyhydric alcohol and ethylene oxide, which includes a urethane acrylate and the like formed by the reaction of (meth) acrylate with a compound having at least two or more isocyanate groups; A product obtained by reacting acrylic acid and / or methacrylic acid with an adduct of the polyhydric alcohol with propylene oxide; an adduct of the polyhydric alcohol with ε-caprolactone Oligomers of the products such as obtained by reacting acrylic acid and / or methacrylic acid are also included.

As the compound having an ethylenically unsaturated group, the following resins can be used in addition to the unsaturated polyester resin, vinyl ester resin and curable (meth) acrylic resin. The resin includes a resin obtained by condensing (meth) acrylic acid with a terminal hydroxyl group of polyester, a polyurethane resin containing an ethylenically unsaturated group, an epoxy resin containing an ethylenically unsaturated group, and an ethylenically unsaturated group. Examples thereof include a phosphorus-containing epoxy resin, a silicon resin containing an ethylenically unsaturated group, and a melamine resin containing an ethylenically unsaturated group.

The filler used in the present invention is powder,
Examples include organic substances and inorganic substances in various shapes such as spherical shapes, whisker-like shapes, and scale-like shapes, or composites and mixtures thereof.

Specific examples of the inorganic filler include known ones such as calcium carbonate, talc, clay, glass powder, silica, aluminum hydroxide, barium sulfate, titanium oxide and alumina. These inorganic fillers,
It is also possible to use two or more kinds in combination.

As specific examples of the organic filler, polystyrene, polyvinyl acetate, polymethylmethacrylate, polystyrene, polyvinylidene chloride microballoons, polyacrylonitrile microballoons and the like can be used. These organic fillers can be used in combination of two or more. Further, an organic filler and an inorganic filler may be used together.

The amount of the inorganic filler and / or the organic filler used is 100 in total of the resin and the reactive diluent.
1-500 parts by weight, preferably 50-
It is 300 parts by weight. If the amount of the filler is too small, the physical properties required for the cured product such as hardness will be insufficient, and the internal stress will increase due to shrinkage during polymerization, which is not preferable. On the other hand, if the amount of the filler is too large, the light transmittance may be lowered and the curing reaction may not proceed sufficiently, or the cured product may be reduced in flexibility and may become brittle.

In the composition of the present invention, the kneading property and the impregnating property of the polymerizable unsaturated compound and the filler are enhanced, and the hardness, strength, chemical resistance and water resistance of the molded product are adjusted. Reactive diluents such as styrene monomers and methylmethacrylate can be added for purposes. Although the amount of the reactive diluent used is not particularly limited, it is generally 0 to 250 parts by weight, preferably 20 to 150 parts by weight with respect to 100 parts of the unsaturated polyester resin, vinyl ester resin or curable acrylic resin. When the amount used exceeds 250 parts, the chemical resistance of the cured product to solvents and the like becomes extremely poor.

Monomers used as the reactive diluents are aromatic monomers such as styrene, α-methylstyrene, p-methylstyrene, chlorostyrene, methylmethacrylate, isobutyl (meth) acrylate, isobornyl (meth) acrylate, distyrene. Cyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, polyoxy (Meth) acrylate monomer such as ethylene (meth) acrylate, N-substituted acrylamide such as N, N-dimethylacrylamide, N, N-diethylacrylamide, N-acryloylmorpholine, N-vinylpyrroyl Don, N- vinyl -N- methylacetamide, N-vinyl formamide, nitrogen-containing unsaturated monomers such as vinyl pyridines, (meth) acrylic acid, and vinyl acetate. Further, as the reactive diluent, a phosphorus-containing polymerizable unsaturated monomer, an isocyanate compound such as butyl isocyanate and phenyl isocyanate, and 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2-hydroxyethyl (meth)
An adduct of a hydroxyl group-containing monomer such as acrylate or 2-hydroxypropyl (meth) acrylate, an adduct of phosphoric acid and the above hydroxyl group-containing monomer, and the like can also be used.

Further, the composition of the present invention requires various pigments, leveling agents generally used as additives for paints, plasticizers, defoamers, thickeners, polymerization inhibitors, antioxidants and the like. According to the above, it may be added to the extent that the storage stability of the composition of the present invention is not impaired.

Curing of the composition of the present invention (hereinafter referred to as putty material) is generally performed by the following procedure. First, a polymerizable compound, a filler, a polymerization initiator, and various additives that are added as necessary are sufficiently kneaded to obtain a putty material. Then
The putty material is overlaid on the object to be coated to a desired thickness, excess putty is removed if necessary, the surface is smoothed, and then light irradiation and heating are performed to carry out a curing reaction of the composition.

The coating thickness of the putty material is arbitrarily determined as needed, but is generally in the range of 1 mm to 4.5 cm. Too thicker than necessary is not preferable, because it may take longer time than necessary for curing, and in some cases, the deep portion of the putty material may be insufficiently cured.

As the light source used for curing of the present invention,
Any light source having a spectral distribution in the photosensitive wavelength region of the initiator in the putty material and capable of irradiating light with an intensity capable of causing a photoreaction, such as a xenon lamp, a halogen lamp, an incandescent lamp, a metal halide lamp, sunlight, etc. Can be used.
It is also possible to use two or more kinds of light sources in combination so as to match the photosensitive wavelength of the initiator.

The light intensity required for curing the putty material of the present invention is
It depends on the photosensitivity (photosensitivity) of the initiator, the curability of the polymerizable compound, the type and amount of the filler, the thickness of the putty material to be applied, etc., but generally 10 mJ / cm ² or more, preferably 10 mJ / cm ² or more.
It is 0 mJ / cm ² or more. If the light intensity is too low, the photoreaction may not proceed sufficiently, the curing reaction of the putty may be insufficient, or the curing in the depth direction may become uneven.

The light irradiation time cannot be unconditionally specified because the effective wavelength range of the light source, the output, the irradiation distance, the thickness of the molding material, etc. are different, but 0.01 hours or more, preferably 0.16. Irradiate for more than an hour.

Further, during the photo-curing reaction, it is preferable to perform light irradiation under a low oxygen concentration in order to reduce polymerization inhibition of the surface of the putty material due to oxygen. For example, after coating the putty material, the surface of the putty material is covered with a light-transmissive film to irradiate it with light, or an inert gas atmosphere such as nitrogen, argon, carbon dioxide, or the above inert gas in air. By blowing on the surface of the composition, it is possible to reduce the oxygen concentration and accelerate curing.

The heating method in the production method of the present invention can be appropriately selected in consideration of the shape and composition of the putty material to be cured, the temperature and time required for curing, and the like. Specific examples include conventional methods, such as heating in a heating furnace, heating with hot air, and radiation with a heater.

Further, there are a method of simultaneously heating while irradiating light and a method of first irradiating light and then heating. As described above, in the case of simultaneously heating while irradiating light, when irradiating light having a spectrum in the infrared region from a light source (lamp), the heat of light (heat rays) may be used as it is. Further, when the amount of heat is insufficient, an infrared lamp, an infrared heater or the like may be used separately.

The putty material composition of the present invention is basically used as a one-part composition, but in some cases, it can be used as a conventional two-part putty in which an initiator is mixed immediately before use. Of course it is possible.

[0044]

The present invention will be described below with reference to examples.
The present invention is not limited to this. Further, "parts" in Examples and Comparative Examples represent parts by weight unless otherwise specified.

(Examples 1 to 3) Unsaturated group equivalent, about 350
Unsaturated polyester resin, trade name: Rigolac 214
1 [manufactured by Showa Highpolymer Co., Ltd.] (including styrene) 50 parts, the initiator and the filler described in Table 1 [talc (average particle size 10 μm
m) 50 parts] was added and sufficiently kneaded by stirring for 15 minutes with a high speed dissolver. The putty material immediately after kneading, the one stored in the dark at 25 ° C. for 3 months after the kneading, and the one stored in the dark at 25 ° C. for 6 months after the kneading were used for the curing experiment.

[0046]

[Table 1]

(Comparative Example 1) Unsaturated group equivalent, unsaturated polyester resin of about 350, trade name: Rigolac 2141
[Showa High Polymer Co., Ltd.] (including styrene) 50 parts, camphorquinone 1 part, azobisisobutyronitrile 1 part and filler [talc (average particle size 10 μm) 50 parts] are added, and a high speed dissolver is used. The mixture was thoroughly kneaded by stirring for 15 minutes. After kneading, what was stored in the dark at 25 ° C. for 3 months was gelled, and thus a curing experiment was not performed.

(Comparative Example 2) Unsaturated group equivalent, unsaturated polyester resin of about 350, trade name: Rigolac 2141
[Showa Highpolymer Co., Ltd.] (including styrene) 50 parts, 1,
1,5,5-Tetrakis (p-diphenylaminophenyl) -2,4-pentadienyl triphenyl-n-butylborate 1 part, tetra-n-butylammonium
1 part of triphenyl-n-butyl borate and 50 parts of a filler [talc (average particle size 10 μm) 50 parts] were added and sufficiently kneaded by stirring for 15 minutes with a high speed dissolver. After kneading, what was stored in the dark at 25 ° C. for 3 months was gelled, and thus a curing experiment was not performed.

(Examples 4 to 5) Vinyl ester resin, trade name: Lipoxy RF-312-7 (containing styrene) [manufactured by Showa Highpolymer Co., Ltd.] in 50 parts, and the initiators and fillers shown in Table 1 50 parts of [talc (average particle size 10 μm)] was added, and the mixture was sufficiently kneaded by stirring for 15 minutes with a high-speed dissolver. Putty material immediately after kneading, 25 ° C after kneading
Stored in the dark for 3 months at 25 ° C after kneading
The sample stored in the dark for 6 months was cured by the following method.

(Examples 6 to 9) Vinyl ester resin, trade name: Lipoxy R-808 [Showa Highpolymer Co., Ltd.] 25
Parts, 25 parts of isobornyl acrylate, 50 parts of the initiator and the filler listed in Table 1 [talc (average particle size 10 μm) 50
Parts] and the mixture was sufficiently kneaded by stirring for 15 minutes with a high-speed dissolver. The putty material immediately after kneading, the one stored in the dark at 25 ° C. for 3 months after the kneading, and the one stored in the dark at 25 ° C. for 6 months after the kneading were used for the curing experiment.

(Examples 10 to 11) 35 parts of trimethylolpropane trimethacrylate, 2-hydroxy-3-
In 15 parts of phenoxypropyl acrylate, the initiator and the filler described in Table 1 [talc (average particle size 10 μm) 5
0 part] was added, and the mixture was sufficiently kneaded by stirring with a high-speed dissolver for 15 minutes. The putty material immediately after kneading, the one stored in the dark at 25 ° C. for 3 months after the kneading, and the one stored in the dark at 25 ° C. for 6 months after the kneading were used for the curing experiment.

Curing Experiment The putty materials produced in Examples 1 to 6 were filled until the recesses of a recessed aluminum plate having a depth of 40 mm were filled, and irradiation was performed for 20 minutes at an irradiation distance of 20 cm using a 1.5 kW halogen lamp. Then, after leaving it at room temperature, the cured product was peeled from the aluminum plate, and then the hardness of the front surface (light-irradiated surface) and the back surface (surface on the back side irradiated with light) was measured with a Barcol hardness meter (hard).
Table 2 shows the results.

The putty materials produced in Examples 7 to 11 were filled until the concave portions of a concave aluminum plate having a depth of 40 mm were filled,
Irradiation distance of 20 cm using a 1.5 kW halogen lamp
Irradiate for 10 minutes, then use an infrared lamp for irradiation distance of 20
Irradiation in cm for 10 minutes. Then, after being left at room temperature, the cured product was peeled off from the aluminum plate, and then the hardness of the front surface (light-irradiated surface) and the back surface (reverse surface to be irradiated with light) were measured with a Barcol hardness meter (hard). Table 2 shows the results.

[0054]

[Table 2]

Performance Test of Cured Product In order to perform a performance test of the cured product, a test plate to which putty material is applied was prepared. Preparation of test plate Aluminum plate (manufactured by Japan Test Panel Co., JIS.H.400
0) Iron plate (manufactured by Nippon Test Panel, SPCC-SB) Zinc treated plate (manufactured by Nippon Test Panel, SPGC) Electrogalvanized plate (Silver Alloy manufactured by Nippon Steel) Water-resistant paper # 150 on the surface of the above four types of plates It was lightly polished to give a test plate.

Preparation of Test Coated Plates The putty materials immediately after kneading produced in Examples 1 to 6 and the putty materials that had been stored in the dark at 25 ° C. for 6 months after kneading were each 10 mm thick on each test plate. With a spatula, and a irradiation distance of 20 using a 1.5 kW halogen lamp.
Irradiation in cm for 20 minutes. The performance test results of the obtained test coated plate are shown in Table 3 for the putty material immediately after kneading and Table 4 for the putty material stored in the dark at 25 ° C. for 6 months after kneading.
Shown in

The putty material immediately after kneading prepared in Examples 7 to 11 and the putty material which had been stored in the dark at 25 ° C. for 6 months after kneading were made to have a thickness of 10 mm on each test plate. Apply with a spatula, using a 1.5 kW halogen lamp,
Irradiation was performed at an irradiation distance of 20 cm for 10 minutes, and then an infrared lamp was irradiated at an irradiation distance of 20 cm for 10 minutes. The performance test results of the obtained test coated plate are shown in Table 3 for the putty material immediately after kneading and in Table 4 for the putty material stored in the dark at 25 ° C. for 6 months after kneading.

[0058]

[Table 3]

[0059]

[Table 4]

Test Method Dryability: The surface tack and internal hardening of the test coated plate were examined by touch with a finger. ◯: No tack on the surface and good curing inside Δ: The surface is slightly tacked, but the inside is cured well. X: There is no tack on the surface, but the inside is poorly cured. Adhesion: Putty adhesion (putty trace) when each test coated plate was bent at 90 ° from the center was examined and evaluated as follows. ：: Putty is adhered. Poor: Only 50% or less of the putty was observed. Abrasiveness: The surface of the test coated plate was abraded using water resistant paper # 150, and the easiness of abrading was compared, and evaluated as follows. ：: The putty coating film is often shaved even if polished lightly. Δ: The putty coating film was shaved, but the polishing felt slightly heavy. X: The polishing is heavy and the putty coating film cannot be scraped well. Water resistance: Iron plate (Nippon Test Panel Co., SPCC-S
Using B) as a test plate, the test coated plate prepared by the above method was polished in order of water resistant papers # 240, # 150 and # 400 to smooth the surface. Commercially available acrylic urethane paint (trade name: manufactured by High Art Isam Paint Co., Ltd.) is spray-coated (dry film thickness: 50 μm) on the ground putty coating film, left at room temperature (20 ° C.) for 30 minutes, and then dried at 60 ° C. in a dryer. It was dried for 60 minutes. After cooling, blister ring box (RH99
%, Temperature 50 ° C.) for 48 hours, and the state of the coating film surface (blister, foaming with a diameter of about 2 mm) and the putty adhesion when bent to a 90 ° angle were examined. The blister was evaluated as described below, and the putty adhesion was the same as the above. ：: No blister was generated. B: Blister is generated in 50% or more of the coating film.

From the curing experiment, the hardness of the cured product (putty) having a thickness of 40 mm was exhibited on both the front surface and the back surface.
Only in the examples of the present invention, the curability of the putty material composition after kneading and after storage for 3 months and 6 months did not change. From the performance test of the cured product, it is clear that the performance of the cured product of the putty material composition of the present invention (drying property, adhesion property, polishing property, water resistance) is good even after storage for 6 months.

[0062]

According to the present invention, by using a polymerization initiator comprising a combination of a hexaarylbiimidazole compound and a hydrogen donor, a sufficient hardness is exhibited on both the front and back surfaces of the polymerizable compound and the filler. You can
Further, it is possible to provide a curable composition suitable for a one-pack type putty material, which has storage stability at room temperature for 6 months or more, and a curing method thereof.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takeo Watanabe 1-1-1, Onodai, Midori-ku, Chiba City, Chiba Prefecture, Showa Denko K.K. 1-1-1 Showa Denko Co., Ltd.

Claims (4)

[Claims] 1. A polymerizable compound having (A) an ethylenically unsaturated group, (B) an inorganic filler and / or an organic filler, and (C) a polymerization initiator of a combination of a hexaarylbiimidazole compound and a hydrogen donor. A curable composition comprising: 2. A polymerizable compound having (A) an ethylenically unsaturated group, (B) an inorganic filler and / or an organic filler, and (C) a polymerization initiator of a combination of a hexaarylbiimidazole compound and a hydrogen donor. A curable putty material composition comprising: 3. The composition according to claim 1, wherein the hydrogen donor is an aromatic thiol compound. 4. A curable composition, which comprises filling the composition according to claim 1, 2 or 3 and then irradiating with light having a photosensitive wavelength of a polymerization initiator in the composition and heating. How to cure things.