JPH027330B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a flexible and tough coating composition with excellent adhesion, heat resistance, and hydrolysis resistance. In recent years, radiation-curable resins have been attracting attention as materials using curing systems using radiation such as electron beams and ultraviolet rays in response to the progress of environmental pollution, increases in energy costs, and restrictions on energy use. As such photosensitive compositions, resin compositions having a backbone of polyester resin, polyurethane resin, epoxy resin, etc. and having double bonds that can be polymerized by radiation are often used, but they generally do not contain volatile organic solvents. It is very desirable from the point of view of environmental conservation, as it contains no or only a small amount of paint. It has been put to practical use in a wide range of fields, including printing inks, adhesives, flexible circuit overlays and other coating materials, solder resists for printed circuit boards, etching resists, plating resists, and inks for printed circuits. However, the curing reaction caused by irradiation with electron beams or ultraviolet rays causes radical polymerization of ethylenic double bonds rapidly in a short period of time, so that shrinkage or residual strain occurs during curing. As a result, compared to conventionally used thermosetting and solvent-volatile resins, it lacks adhesion to surrounding resins or metals, which often limits its use in the various applications listed above. Ta. On the other hand, although there are radiation-curable resins that have excellent adhesion, they often have problems with their original characteristic of rapid curing. For example, epoxy resin and α, β-
Radiation-curable resins whose main constituent is adducts of unsaturated acids cure rapidly when exposed to radiation and have high hardness, but they have poor toughness and also have poor adhesion due to large shrinkage during curing. It had the following drawback. Radiation-curable resins containing liquid polybutadiene or liquid polyisoprene and acrylic acid ester as main components exhibit excellent adhesion when irradiated with radiation, but require a relatively long time for complete curing. In view of these points, we are improving materials, improving composition,
Furthermore, although thermoplastic resins and thermosetting resins that are not directly involved in the radiation curing reaction have been added, it is often not possible to achieve the intended purpose. The purpose of the present invention is to provide a coating composition that provides flexibility and toughness to the resulting cured product by modifying the unsaturated polyurethane resin itself, and that also has significantly improved adhesion to various adherends. Our goal is to provide the following. The present invention is based on the general formula (R ¹ and R ² are hydrogen or methyl group, X is hydrogen or methyl group, Cl, Br or I, n is a number of 0.1 or more) The epoxy group of the epoxy resin is ring-opened with amines. The present invention relates to a coating composition containing a modified epoxy resin as one component and an unsaturated polyurethane resin having two or more terminal groups having a polymerizable ethylenic double bond and an OH group. The unsaturated polyurethane resin of the present invention can be produced in various ways using, for example, a polyol (A), an organic polyisocyanate (B), an epoxy resin (C), an amine (D), and an ethylenically unsaturated compound (B) having active hydrogen. It can be obtained by the following method. As the polyol (A), various polyester polyols, polyether polyols, and other polyols can be used. Examples of polyester polyols include aliphatic dicarboxylic acids having 4 to 20 carbon atoms such as adipic acid, suberic acid, sebacic acid, and brassylic acid, terephthalic acid, and isophthalic acid as acid components, and ethylene glycol, propylene glycol, neopentyl glycol, Polyester polyols whose polyol components include aliphatic diols having 1 to 6 carbon atoms such as hexamethylene glycol, ether glycols such as diethylene glycol and dipropylene glycol, spiroglycols, and N-alkyl dialkanolamines such as N-methyldiethanolamine; Polycaprolactone polyol etc. can be used,
Specific examples include polyethylene adipate polyol, polybutylene adipate polyol,
Adipate polyols such as polyethylene propylene adipate polyol, terephthalic acid polyols (e.g. Toyobo Co., Ltd., product name Vylon RUX,
Vylon RV-200L), polycaprolactone polyol (e.g., Daicel Chemical, trade name Plaxel)
212, Praxel 220), etc. Specific examples of polyether polyols include polyoxyethylene polyol, polyoxypropylene polyol, polyoxytetramethylene polyol, and the like. In addition, other polyols include polycarbonate polyol (e.g., West Germany, Bayer AG, product name Desmofene 2020E), polybutadiene polyol (e.g., Nippon Soda, product name G-1000, G-
2000, G-3000, Idemitsu Petrochemical, product name Poly bd
R-45HT), polypentadiene polyol, castor oil polyol, and the like. These polyols can be used alone or in combination of two or more. Organic polyisocyanate (B) used in the present invention
Examples include diphenylmethane diisocyanate (MDI), tolylene diisocyanate (TDI), tolidine diisocyanate (TODI), xylylene diisocyanate (XDI), naphthylene diisocyanate (NDI), isophorone diisocyanate ( IPDI),
These include diisocyanates such as hexamethylene diisocyanate (HDI), dicyclohexylmethane diisocyanate (HMDI), and lysine diisocyanate (LDI), and polyisocyanates such as triphenylmethane triisocyanate, polymethylene polyphenyl isocyanate (PAPI), and carbodiimide-modified MDI. can be used alone or in combination of two or more. A preferred example of the epoxy resin (C) used in the present invention is an epoxy resin containing one or more epoxy groups in one molecule and having an epoxy equivalent of 100 to 4,000, preferably 120 to 1,000, particularly bisphenol-based epoxy resins. Epoxy resins are preferred, and epoxy resins having the following general formula are most preferred. In the formula, R ¹ and R ² are hydrogen or a methyl group, X is hydrogen,
Methyl group, Cl, Br or I, n represents a number of 0.1 or more, and n is preferably a number of 1 or more. The amines (D) are preferably compounds containing secondary amino groups, such as dialkylamines such as diethylamine, dipropylamine, and dibutylamine, N-methylethanolamine, N-butylethanolamine, diethanolamine, dipropanolamine, etc. These alkanolamines can be used alone or in combination of two or more. In the present invention, various types of ethylenically unsaturated compounds (E) having active hydrogen can be used, but representative examples include ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, Mono(meth)acrylates of dihydric alcohols such as 1,4-butanediol, diethylene glycol, dipropylene glycol, polyethylene glycol, and polypropylene glycol; mono(meth)acrylates of trihydric alcohols such as trimethylolethane, trimethylolpropane, and glycerin; ) acrylates, di- and tri(meth)acrylates of tetrahydric or higher alcohols such as pentaerythritol, etc., and these can be used alone or in combination of two or more. In the synthesis of the unsaturated polyurethane resin of the present invention, it is optional to use a chain extender (F) in addition to the above-mentioned components, and such chain extenders include, for example, 2- to 6-functional chain extenders with a molecular weight of 500 or less. Examples include polyols having a molecular weight of 500 or less and diamines having a primary or secondary unterminated amino group. Suitable chain extenders include (a) ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butanediol, hexanediol,
Polyols such as glycerin, trimethylolpropane, pentaerythritol, sorbitol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, xylylene glycol (b) hydrazine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 1,
Diamines such as 4-cyclohexanediamine (c) Alkanolamines such as ethanolamine, diethanolamine, and triethanolamine (d) Hydroquinone, pyrogallol, 4,4'-isopropylidene diphenol, aniline, and the above polyols and diamines and polyols with a molecular weight of 500 or less obtained by adding propylene oxide and/or ethylene oxide to alkanolamines in any order. The unsaturated polyurethane resin of the present invention can be synthesized by various methods using the above components, but the amines used to open the epoxy group generally have high reactivity with the NCO group of the organic polyisocyanate.
The presence of an NCO group is not preferred because ring opening of the epoxy group is likely to be inhibited. Therefore, the ring-opening reaction of the epoxy group with amines can be carried out alone, during the urethanization reaction, or when all the NCO groups have been consumed after the completion of the reaction.
A stepwise synthesis method in which the epoxy ring-opening reaction and the urethanization reaction are separated is desirable. Furthermore, when using an epoxy resin that does not have active hydrogen, it is appropriate to first perform a ring-opening reaction to generate OH groups, and then proceed to the urethanization reaction. A specific example of a synthesis method that takes these limitations into consideration is:
Compound (A), compound (B), and if necessary, compound (F) are reacted to synthesize a prepolymer with terminal NCO, and then compound (E) is reacted to synthesize a prepolymer with terminal NCO, and a prepolymer with terminal NCO is synthesized. A method of reacting ring-opened compound (C) with compound (D) and the above prepolymer,
A method for synthesizing an unsaturated polyurethane resin by reacting compounds (A), (C), (E) and optionally compound (F) with compound (B), and carrying out a ring-opening reaction with compound (D). A) and
(B), synthesize terminal NCO prepolymers from compounds (B) and (E), and add reactants of compounds (C) and (D) and optional compounds to the mixture of these two types of prepolymers. A method for reacting (F) can be exemplified. In addition, when the reaction product of the compounds (C) and (D) of the present invention has three or more active hydrogens in the molecule, it is desirable to adopt a synthesis method that takes into consideration prevention of gelation during synthesis. In the epoxy ring-opening reaction of the present invention, it is preferable to ring-open all of the epoxy groups, but of course some epoxy groups may remain. Usually, the amines are added in an amount of about 1 or less equivalents to the epoxy groups, preferably It is best to use about 0.2 to 1 equivalent. The reaction is usually carried out at about 20 to 180°C, preferably about 100 to 150°C, but if the reaction solution contains compounds or groups having ethylenic double bonds, these compounds or To prevent thermal polymerization of the group,
It is appropriate to consider the reaction temperature and addition of a thermal polymerization inhibitor. When synthesizing the unsaturated polyurethane resin of the present invention, the ratio of each component can be appropriately determined from a wide range depending on the intended use of the coating composition, but usually the chemical equivalent ratio of NCO groups to active hydrogen (NCO
Index) is about 0.2 to 0.98, preferably about 0.3 to 0.98, including active hydrogen generated by ring opening of the epoxy group.
It is best to carry out the reaction within a range of 0.9, and the reaction is usually carried out within a range of about 30 to 0.9, except when opening the epoxy group.
The temperature is preferably 130°C, preferably about 40-120°C. The OH group concentration in the unsaturated polyurethane resin obtained is preferably 0.05 meq/g or more. In the present invention, the unsaturated polyurethane resin can be synthesized without a solvent, in the presence of an organic solvent, or in the presence of an ethylenically unsaturated compound used as a crosslinking agent, which will be described later. Examples of organic solvents include ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate and methyl propionate, ethers such as dioxane and cellosolve acetate, and dimethylformamide and dimethyl sulfoxide. In the present invention, other compounds can be mixed within a range that does not impair the purpose. Specific examples of these compounds include unsaturated polyester resins, saturated polyester resins, epoxy resins, and (meth)
Esters with acrylic acid, polyurethane resins, diallyl phthalate resins, ketone resins, alkyd resins, phenolic resins, rosin-modified phenolic resins, rosin esters, maleic acid-modified rosin esters, urea resins, melamine resins, polyamide resins, styrene (meth) ) Acrylic acid copolymers or their esters, styrene-maleic anhydride resins or their esters, poly(meth)acrylates, _C5 - _C9 petroleum resins, hydrogenated petroleum resins,
Examples include polybutadiene, natural or synthetic rubber, polyethylene, polypropylene, ethylene-vinyl acetate copolymer resin, polyvinyl alcohol, and wax. Further, these known compounds can be added before or during the reaction as long as they do not interfere with the synthesis of the unsaturated polyurethane resin of the present invention. In the present invention, an ethylenically unsaturated compound can be used as a crosslinking agent if necessary when curing the unsaturated polyurethane resin. Various known compounds can be used as ethylenically unsaturated compounds, but typical examples include styrene,
Vinyltoluene, chlorostyrene, t-butylstyrene, α-methylstyrene, divinylbenzene, acrylic acid, methacrylic acid, methyl, ethyl, isopropyl, n-butyl, t-butyl, α-ethylhexyl, n -Nonyl, n-decyl, lauryl, stearyl ester, etc., n-butoxyethyl, cyclohexyl, phenoxyethyl, tetrahydrofurfurin, -lycidyl, allyl, benzyl, tribromophenyl of acrylic or methacrylic acid,
2,3-dichloropropyl, 3-chloro-2-hydroxypropyl, N,N-dimethylaminoethyl, N,N3 diethylaminoethyl, Nt-
Butylaminoethyl ester, etc., ethylene glycol mono(meth)acrylate, propylene glycol mono(meth)acrylate, diethylene glycol mono(meth)acrylate, dipropylene glycol mono(meth)acrylate, molecular weight (hereinafter referred to as MW) 200 to 1000. Polyethylene glycol mono(meth)acrylate, MW200
~1000 polyethylene glycol monomethyl ether mono(meth)acrylate, MW200~1000
polypropylene glycol mono(meth)acrylate, polypropylene glycol monomethyl ether mono(meth)acrylate with MW200-1000, polyethylene glycol monoethyl ether mono(meth)acrylate with MW200-1000,
MW200-1000 polypropylene glycol monoethyl ether mono(meth)acrylate, ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, 1,3
-propanediol di(meth)acrylate,
1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, glycerin di(meth)acrylate, glycerin tri(meth)acrylate,
trimethylolethane di(meth)acrylate,
Trimethylolethane tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, acrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide,
Examples include ethylene bisacrylamide, diacryl phthalate, triallyl isocyanurate, dibutyl fumarate, and vinyl acetate. However, if present during the urethanization reaction, ethylenically unsaturated compounds having active hydrogen should be excluded from the above. In the present invention, the weight ratio of the unsaturated polyurethane resin to the ethylenically unsaturated compound is preferably 20:80 to 95:5, more preferably 50:50 to 80:20. A known thermal polymerization inhibitor may be added for the purpose of stably storing the coating composition of the present invention. For example, hydroquinone, mono-tert-butylhydroquinone, 2,5-di-tert-butylhydroquinone, hydroquinone monomethyl ether, catechol, p-tert-butylcatechol,
Examples include benzoquinone, 2,5-di-tert-butylbenzoquinone, 2,5-diphenyl-p-benzoquinone, 2,6-di-tert-butyl-p-cresol, and picric acid. It is desirable that these thermal polymerization inhibitors prevent only the thermal polymerization reaction (dark reaction) without inhibiting the photocuring reaction, so the amount added should be adjusted based on the total amount of the unsaturated polyurethane resin and crosslinking agent. It is desirable that the amount ranges from 0.001 to 2.5% by weight, preferably from 0.005 to 1% by weight. Furthermore, in the present invention, commonly used additives such as dispersants, lubricants, abrasives, and antistatic agents can be added as necessary. Furthermore, in the present invention, commonly used additives such as colorants, flame retardants, and lubricants, and fillers such as glass, mica, and iron powder may be added. The coating composition of the present invention can be cured by a known method. For example, when curing with an electron beam, the accelerating voltage is 100 to 1000 KeV, preferably 150 KeV.
A cured product can be obtained by irradiating in an inert gas atmosphere using an electron beam irradiation device of ~300 KeV such that the total absorbed dose is 0.5 to 20 Mrad, preferably 2 to 15 Mrad. In addition, in the present invention, other curing means such as those using thermal energy such as infrared rays, high frequency waves, or microwaves, that is, heating curing methods, curing methods using ultraviolet rays obtained from mercury lamps, xenon lamps, etc., or
A method of curing by irradiating with other radiation such as rays or gamma rays can also be used. In the present invention, when using high-energy ionizing radiation such as electron beams, X-rays, and γ-rays, which have the effect of being absorbed by substances and emitting secondary electrons, it is not necessary to add a polymerization initiator. is also good, but
When curing by heating or ultraviolet rays, it is preferable to add a thermal polymerization initiator or a photopolymerization initiator. Examples of these thermal or photopolymerization initiators include ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide, hydroperoxides such as cumene hydroperoxide and tert-butyl peroxide, and di-tert-butyl peroxide. Examples include dialkyl peroxides such as oxide and dicumyl peroxide, peroxy esters such as tert-butyl peroxylaurate and tert-butyl peroxybenzoate, and azo compounds such as azobisisobutyronitrile.
Further, polymerization accelerators such as metal soaps such as cobalt and manganese for the above-mentioned ketone peroxides, or reducing amines for the above-mentioned hydroperoxides can also be used in combination. As described above, the coating composition of the present invention is composed of an unsaturated polyurethane resin containing as a component a modified epoxy resin in which epoxy groups are ring-opened with amines, and the cured product thereof is flexible and strong, and has good adhesion and It has excellent heat resistance and hydrodispersion resistance,
It is useful as a coating composition. A detailed explanation will be given below with reference to synthesis examples and examples. Note that "parts" or "%" simply means parts by weight or percent by weight. Synthesis Example 1 Epikote 1001 (molecular weight
900, epoxy equivalent 475) 225.9g, diethanol
48.0g, dioxane 274.5g and hydroquinone
0.55 g was added, heated to 1085°C, and reacted for about 3 hours under reflux of dioxane to obtain a modified epoxy resin solution (A) in which the epoxy group was ring-opened. Synthesis Example 2 In Synthesis Example 1, diethanolamine was added to 22.5
g, hydroquinone 0.5g, dioxane 248.9
Modified epoxy resin solution was prepared in the same manner except that g was
I got (B). Synthesis Example 3 Put TDI (75.0g) into a reactor equipped with a stirring device,
Warmed to 80℃, Byron RV200L (molecular weight 1940)
Gradually drop a mixed solution of 418.1 g, dioxane 493.35 g, and dibutyltin dilaurate 0.25 g,
The mixture was heated to ℃ and allowed to react for about 3 hours. The above reactants were placed in a separately prepared reactor equipped with a stirring device.
Add 971.3 g of the mixture and warm to 80°C, and gradually dropwise add a mixed solution of 22.15 g of 2-hydroxyethyl acrylate (ethylene glycol monoacrylate, hereinafter abbreviated as HEA), 1.0 g of hydroquinone, and 22.25 g of dioxane, for about 3 hours. The reaction was carried out to obtain urethane prepolymer (C). Synthesis Example 4 In Synthesis Example 3, polycaprolactone polyol (trade name Plaxel) was used instead of Vylon RV200L.
A urethane prepolymer (D) was obtained in the same manner as in Synthesis Example 3 except that urethane prepolymer (D) was used. Synthesis Example 5 Put IPDI (154.18g) into a reactor equipped with a stirring device,
Byron RV200L was heated to 80℃ at 465.6
A mixed solution of 214.5 g of Desmophene E (molecular weight 2000), 1.75 g of hydroquinone, and 872.62 g of dioxane was gradually added, heated to 90°C, and a total of 0.25 g of dibutyltin dilaurate was added in two portions. After reacting for about 3 hours, add HEA.
A mixed solution of 36.30 g of dibutyltin dilaurate and 0.04 g of dibutyltin dilaurate was gradually added dropwise to obtain urethane prepolymer (E). Synthesis Example 6 175.0 g of the modified epoxy resin solution (A) obtained in Synthesis Example 1 was placed in a reactor equipped with a stirring device, heated to 80°C, and the urethane prepolymer (A) obtained in Synthesis Examples 3 and 4 was added. C) and (D) 569.4g and 380.0g respectively
A mixed solution of g was gradually added and reacted for about 1.5 hours to obtain an unsaturated polyurethane resin solution (). This solution had a solid content of 50% and had 0.78 meq/g of OH groups in the solid content. Synthesis Example 7 In Synthesis Example 6, instead of the modified epoxy resin solution (A), 159.0g of the same (B) and 522.0g and 427.0g of the urethane prepolymers (C) and (D) were used, respectively, and the same reaction was carried out. An unsaturated polyurethane resin solution () was obtained. This solution had a solid content of 50% and contained 0.38 meq/g of OH groups in the solid content. Synthesis Example 8 350.4g of the modified epoxy resin solution (A) obtained in Synthesis Example 1 was placed in a reactor equipped with a stirring device, and 682.35g of urethane prepolymer (E) was gradually dropped into the mixture heated to 80°C. The mixture was reacted for about 2 hours to obtain an unsaturated polyurethane resin solution (2). The solid content of this solution was 50%, and the solid content contained 2.10 meq/g of OH groups. Synthesis Example 9 Put MDI (218.5g) into a reactor equipped with a stirring device and
Byron RV200L (360.3
g), polyethylene adipate (molecular weight 1000)
142.8g, Epicote 1001 (97.64g), dibutyltin dilaurate 0.17g and cyclohexanone
915.3g of the mixed solution was gradually added dropwise and reacted for about 3 hours and 30 minutes while heating to 90℃, and then
After gradually dropping a mixed solution of 60.85 g of HEA and 1.83 g of hydroquinone and reacting for about 2 hours and 30 minutes,
11.8 g of 1,4-butanediol was added and the reaction was further continued for about 2 hours. Next, 21.5 g of diethanolamine was added while heating to 120°C, and the mixture was reacted for about 3 hours to obtain an unsaturated polyurethane resin solution (2) containing a modified epoxy resin. The solid content is 50%,
The OH group concentration in the solid content was 0.67 meq/g. Synthesis Example 10 In the same manner as in Synthesis Example 9, except that 11.56 g of N-methylethanolamine was used instead of diethanolamine, an unsaturated product with a solid content of 50% and an OH group concentration of 0.34 meq/g in the solid content was prepared. A polyurethane resin solution () was obtained. Synthesis Example 11 In Synthesis Example 6, instead of the modified epoxy resin solution (A), the epoxy resin solution (F) obtained by removing diethanolamine from the components in the synthesis of (A) was used at 144.3
An unsaturated polyurethane resin solution () was obtained in the same manner except that g was used. Synthesis Example 12 An unsaturated polyurethane resin solution () was obtained in the same manner as in Synthesis Example 7, except that 99.1 g of the epoxy resin solution (F) was used instead of the modified epoxy resin solution (B). Synthesis Example 13 In Synthesis Example 6, 30.3g of a 50% dioxane solution of glycerin was used instead of the modified epoxy resin solution (A).
The same procedure was used except that the solid content was 50% and the solid content was
An unsaturated polyurethane resin solution () with an OH group concentration of 0.68 meq/g was obtained. Synthesis Example 14 In the same manner as in Synthesis Example 7, except that 8.45 g of diethylene glycol was used instead of the modified epoxy resin solution (B), an unsaturated polyurethane resin solution () was prepared.
I got it. Synthesis Example 15 An unsaturated polyurethane resin solution () was obtained in the same manner as in Synthesis Example 9 except that diethanolamine was not added. Examples 1 to 6 The unsaturated polyurethane resin solutions () to () obtained in the above synthesis examples were mixed in the compositions shown in Table 1 to obtain radiation-curable compositions. Apply the above composition onto a 50μ thick steel plate with a degreased surface using an applicator until the dry thickness is 30μ.
After drying in an oven at 80°C for 3 minutes, using a curtain beam type electron beam irradiation device, the acceleration voltage was 200KeV and the beam current was
The coating film was cured by irradiation at 12 mA with an irradiation dose of 10 Mrad. The properties of the resulting coating film measured in accordance with JIS5400 are also shown in Table 1. In addition, in order to examine the durability of the coating film, the coating film was placed in a constant temperature and humidity chamber adjusted to 70°C and 95% RH for 400 hours, humidified and heated, and its properties were evaluated again. I saw a change. In the table, PU indicates unsaturated polyurethane resin solution, HEMA indicates 2-hydroxyethyl methacrylate, HPMA indicates 2-hydroxypropyl methacrylate, NPGDA indicates neopentyl glycol diacrylate, and TMPTA indicates trimethylolpropane triacrylate. Comparative Examples 1 to 6 Using the unsaturated polyurethane resin solutions () to () obtained in the above synthesis examples, a mixture with the composition shown in Table 2 was cured in the same manner as in the examples to form a coating film. Obtained. The properties and durability of these coating films were evaluated in the same manner as in the Examples and compared with the Examples. The results are also shown in Table 2.

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【table】

Claims (1)

[Claims] 1. General formula (R ¹ and R ² are hydrogen or methyl group, X is hydrogen or methyl group, Cl, Br or I, n is a number of 0.1 or more) The epoxy group of the epoxy resin is ring-opened with amines. A coating composition comprising a modified epoxy resin as one component and an unsaturated polyurethane resin having two or more terminal groups having a polymerizable ethylenic double bond and an OH group. 2. The composition according to claim 1, wherein the unsaturated polyurethane resin has 0.05 meq/g or more of OH groups in the molecular chain. 3 Ethylenically unsaturated compound as a crosslinking agent,
3. The composition according to claim 1, wherein the ratio of the former to the unsaturated polyurethane resin is in the range of 5:95 to 80:20.