JP2004224972A - Curable composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of a reaction product of dicyclopentadiene with an unsaturated carboxylic acid or an alcohol, comprising the brittleness of a cured product caused by a rigid dicyclopentadienyl structure and low molecular weight of the reaction product, by incorporating a soft material compatible with the air curability of the dicyclopentadienyl structure and having a relatively high molecular weight. <P>SOLUTION: The subject curable composition contains 5-90 mass% radically polymerizable monomer containing the dicyclopentadienyl structure and 1-50 mass% polyalkylene glycol. The polyalkylene glycol has a mass-average molecular weight of 300-5,000 and is a a polypropylene glycol or a block polymer containing ≥30 mass% block having a polypropylene glycol structure. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【００２３】
（実験例：硬化塗膜作成）
組成物１〜５を厚さ０．８ｍｍのＳＰＣＣテストピース（日本テストパネル社製）に１００μｍのドクターブレードで塗布した。これを１２０℃に加熱してある送風乾燥機に入れ、１０分加熱硬化させた。
【００２４】
（実験例：硬化物作成）
組成物１〜５を内径５ｃｍ、深さ１．０ｃｍのＳＵＳ製型枠に入れ、１００℃で３０分加熱硬化させた。室温まで冷却したのち、型枠から外した。
【００２５】
（実験例：特性評価）
（１）硬化性：硬化被膜及び硬化物を外観及び指触で観察した。
判定基準： ○良好 △表面タック有り ×不良
（２）耐溶剤性：硬化物をアセトンに浸析し、室温で２４時間静置した。

（３）耐水性：硬化塗膜をイオン交換水に浸析し、５０℃で２４時間静置した。

（４）密着性：硬化塗膜をＪＩＳ Ｋ５４００ ８．５．２（碁盤目テープ法）のすきま間隔１ｍｍ（ます目１００）で評価した。
（５）鉛筆硬度：硬化塗膜をＪＩＳ Ｋ５４００ ８．４（鉛筆引っかき値）により評価した。
（６）耐衝撃性：硬化塗膜をＪＩＳ Ｋ５４００ ８．３．２（耐衝撃性 デュポン式）により評価した。
（７）耐屈曲性：硬化塗膜をＪＩＳ Ｋ５４００ ８．２（エリクセン値）により破断距離を求めた。（２０℃）
【００２６】
結果を表２に示した。
【００２７】
【表２】

【００２８】
【発明の効果】
実施例で明らかな如く、本発明によれば柔軟で強度が高い硬化塗膜、硬化物が容易に得られる、硬化性に優れた硬化性組成物を製造することができる。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a radical-curable composition used for paints, adhesives, casting materials and the like.
[0002]
[Prior art]
Compositions containing a dicyclopentadienyl structure exhibit air drying properties and have been widely used for vinyl ester resins, alkyd resins and the like since ancient times. For example, Japanese Patent No. 3279964 discloses a method for producing an unsaturated polyester by reacting a reaction product of dicyclopentadienyl, maleic anhydride and water, and a polyhydric alcohol and a polybasic acid. Recently, an epoxy resin has been actively combined with the resin. For example, Japanese Patent No. 3351833 discloses an unsaturated ester obtained by reacting an unsaturated monobasic acid and an unsaturated polybasic acid with an epoxy resin. A technique relating to a repair material having an asphalt structure containing a (meth) acrylic monomer containing a dicyclopentadienyl group is disclosed.
[0003]
[Problems to be solved by the invention]
In general, a product obtained by reacting dicyclopentadiene with an unsaturated carboxylic acid or alcohol has a strong affinity for oxygen with a dicyclopentadienyl structure and has a tertiary carbon, particularly an allylic tertiary carbon. It is known that this is an excellent curable composition which has good air curability and can form a cured film having high hardness because it contains oxygen to form a peroxide by combining with oxygen. On the other hand, the dicyclopentadienyl structure itself is rigid, and there is a disadvantage that the cured product is brittle because of the small molecular weight of the reaction product. To compensate for this, epoxy resins having a relatively large molecular weight are used in combination with dicyclopentadiene to react with unsaturated carboxylic acids and alcohols.In this case, however, the epoxy resin itself is rigid, Since the resin itself has no air curability, there is a problem that the effect is limited in order to reduce the air curability. In order to solve these problems, it has been widely practiced to dissolve and dilute a reaction product obtained from dicyclopentadiene with (meth) acrylate or an aromatic vinyl compound to supplement the physical properties of a cured product. In this case, since the dicyclopentadienyl structure is diluted, the air curability is poor, and other peroxides are used in combination, or a catalyst called a dryer that promotes peroxide formation by air oxidation is added. However, the reactivity between the monomer used for dilution and dissolution and the reactant obtained from dicyclopentadiene is poor, and it is difficult to achieve both curability and flexibility. Further, in this case, the dicyclopentadienyl structure becomes thin, and there is a disadvantage that the curability is inferior due to polymerization inhibition by oxygen particularly on the surface in contact with air.
[0004]
[Means for Solving the Problems]
The present invention has been made in view of these problems, and aims to solve the problem by coexisting a flexible material having a relatively large molecular weight, which can coexist with the air-curing property of the dicyclopentadienyl structure.
[0005]
BEST MODE FOR CARRYING OUT THE INVENTION
The present inventors have conducted intensive studies on materials that can achieve the object based on the above assumption, and as a result, have found that polyalkylene glycols, particularly materials having a polypropylene glycol structure, are effective, and have led to the present invention. It is. That is, the present invention relates to a curable composition characterized by containing a radically polymerizable monomer having a dicyclopentadienyl structure and a polyalkylene glycol.
[0006]
In addition, the present invention has found an appropriate combination as a result of studying preferable auxiliary materials for expanding the applicable range of the curable composition according to the present invention. That is, the present invention relates to a curable composition comprising, in addition to the curable composition, a peroxide alone having a 10-hour half-life temperature of 80 ° C. or higher, particularly an organic hydroperoxide and a transition metal compound, particularly a cobalt compound. Composition.
[0007]
In the present invention, the radical polymerizable monomer containing a dicyclopentadienyl structure refers to dicyclopentadiene such as an acryl group, a methacryl group, a maleyl group, an itacoil group, an allyl group, an aromatic vinyl group, a vinyl ester group, and a vinyl ether. A compound in which a radical polymerizable group is directly or indirectly bonded. Examples of the directly bonded monomers include, for example, dicyclopentadienyl acrylate, dicyclopentadienyl methacrylate, bis (acroyl) dicyclopentadiene, bis (methacryloyl) dicyclopentadiene, dicyclopentadienyl maleate, and maleic acid Di (dicyclopentadienyl) acid, dicyclopentadienyl itaconate, di (dicyclopentadienyl) itaconate, dicyclopentadienyl allyl ether, dicyclopentadienyl bis (oxyallyl), dicyclopentane Examples include, but are not limited to, dienyl vinyl ether, dicyclopentadienyl bis (oxyvinyl), 4-dicyclopentadienyl styrene, and the like.
[0008]
Further, those indirectly bonded are compounds having a structure in which a connecting group other than these is inserted between a dicyclopentadienyl group and a radical polymerizable group. Examples of such a linking group include, but are not particularly limited to, alkylene groups such as methylene, ethylene, propylene, butylene, and cyclohexylene; and polyoxymethylene, polyoxyethylene, polyoxypropylene, and polyoxybutylene. Various types such as polyoxyalkylene group, arylene group such as phenylene, naphthylene, benzylidene and the like, poly (oxyalkylenecarbonyloxy) such as poly (oxyethylcarbonyloxy), poly (oxypropylcarbonyloxy), poly (oxybutylcarbonyloxy), etc. The linking group in the present invention can be used as long as it does not substantially affect the radical polymerization reaction.
[0009]
In the present invention, the radically polymerizable monomer containing a dicyclopentadienyl structure is a condition that includes at least one dicyclopentadienyl structure and at least one radically polymerizable group. May be included. Further, the inclusion of a functional group other than these is not excluded unless the radical polymerizability is not particularly adversely affected.
[0010]
In the present invention, the polyalkylene glycol is cured without impairing the curability, and has a role of improving the flexibility of the cured product after curing. Polyalkylene glycol has a structure in which alkylene groups such as methylene, ethylene, butylene, and cyclohexylene are connected by an ether bond, and both the alkylene group and the ether group are bonds having a high degree of freedom. Certain polyalkylene glycols are also very flexible. It is well known that ether bonds form peroxides by air oxidation, but this effect is also effective in the present invention, and the affinity with oxygen derived from the dicyclopentadienyl structure is high. As a result, oxygen dissolved in the cured product easily reacts with the ether bond, thereby promoting the formation of peroxide. As a result, when radical polymerization is caused for the purpose of curing the composition, peroxides derived from ether bonds are also decomposed to generate radicals. Generate As a result of this symbiotic action, in the cured product, a dicyclopentadienyl structure, a polyalkylene glycol, and a polymer formed from a radical polymerizable group form a covalent bond with each other.
[0011]
As the polyalkylene glycol in the present invention, various materials can be used as described above, and it is particularly preferable to use a polypropylene glycol or a block polymer containing at least 30% by mass of a block having a polypropylene glycol structure. As described above, in the present invention, the symbiotic action of the ether bond contained in the polyalkylene glycol is utilized, and a higher result of the ether bond ratio is preferable. Accordingly, a polyalkylene glycol having a short alkylene moiety is preferable. On the other hand, in the present invention, as described above, the affinity with oxygen of the dicyclopentadienyl structure is utilized, but in order to utilize this effect, the affinity between the dicyclopentadienyl structure and the polyalkylene glycol is also increased. is necessary. The dicyclopentadienyl structure has a low polarity because it has no polar portion, and a low-polarity polyalkylene glycol having a long alkylene portion has good affinity. In the present invention, polypropylene glycol is mentioned as a particularly preferable one for these conflicting reasons. In the above discussion, the polyalkylene glycol is limited to one type, but a plurality of polyalkylene glycols can be used in combination. The purpose can be achieved simply by coexisting a polyalkylene glycol having a heterogeneous structure, but a block polymer bonded by a covalent bond is preferred. Also in this case, the polypropylene glycol structure is effective, and the block polymer with another polyalkylene glycol has an effect close to that of polypropylene glycol alone. Among them, the polypropylene glycol structure is particularly 30% by mass or more, particularly 50% by mass or more. Inclusions are preferred.
[0012]
The polyalkylene glycol in the present invention is not particularly limited, but one having a weight average molecular weight of 300 to 5,000, particularly preferably 500 to 3,000 is used. Here, if the molecular weight is small, the number of molecules that do not participate in the bond derived from the ether bond in the cured product tends to increase. On the other hand, if the molecular weight is large, not only the viscosity of the composition becomes high, but also the solubility is lowered and the affinity with the dicyclopentadienyl structure becomes poor.
[0013]
In the present invention, the radical polymerizable monomer having a dicyclopentadienyl structure and the polyalkylene glycol are respectively 5 to 90% by mass, preferably 10 to 85% by mass, particularly preferably 30 to 80% by mass, and 1 to 50% by mass. %, Preferably 5 to 45% by mass, particularly preferably 20 to 40% by mass. Here, if the amount of the radical polymerizable monomer containing a dicyclopentadienyl structure is small, the curability is reduced, the free polyalkylene glycol is increased, and the physical properties are reduced. On the other hand, if the amount is large, the curability is improved, but the ratio of the polyalkylene glycol is reduced, and the cured product becomes brittle. When the amount of polyalkylene glycol is small, the cured product becomes brittle, and when the amount is large, the dicyclopentadienyl structure becomes thin and the curability decreases. Although not particularly limited, the amount of the polyalkylene glycol used is 0.1 to 2 parts by mass, preferably 0.2 to 2 parts by mass, based on 1 part by weight of the radical polymerizable monomer having a dicyclopentadienyl structure. 1.5 parts by mass, particularly preferably 0.3 to 1 part by mass, is used.
[0014]
In the present invention, it is also possible to use another radical polymerizable monomer copolymerizable with a radical polymerizable monomer having a dicyclopentadienyl structure. Examples of such a monomer include monofunctional monomers such as acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxybutyl acrylate, and phenyl acrylate. Acrylates, polyfunctional acrylates such as ethylene glycol diacrylate, propylene glycol diacrylate, butylene glycol diacrylate, glycerin polyacrylate, pentaerythritol polyacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, bisphenol A diacrylate, Methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, methacrylic acid Monofunctional methacrylates such as hydroxyethyl, 2-hydroxybutyl methacrylate, phenyl methacrylate, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, butylene glycol dimethacrylate, glycerin polymethacrylate, pentaerythritol polymethacrylate, polyethylene glycol dimethacrylate , Polyfunctional methacrylates such as polypropylene glycol dimethacrylate, bisphenol A dimethacrylate, maleic anhydride, maleic acid, methyl maleate, methyl maleate, dimethyl maleate, ethyl maleate, diethyl maleate, diethyl maleate and the like, methyl itaconate , Dimethyl itaconate, ethyl itaconate, diethyl itaconate, butyl itaconate, ita Itaconic acids such as phosphate, dimethyl styrene, vinyl toluene, and aromatic vinyl compounds such as vinyl naphthalene, and is not particularly limited.
[0015]
In the present invention, additives can be used to promote curing. Preferred as such an additive is a combination of a peroxide and a transition metal compound having a 10-hour half-life temperature of 80 ° C. or higher when measured alone, and particularly preferred is a 10-hour half-life temperature having a 10-hour half-life temperature. A combination of an organic peroxide at 80 ° C. or higher and a cobalt compound is exemplified.
[0016]
Here, the peroxide acts mainly to promote radical polymerization of the radically polymerizable monomer. Here, the peroxide is preferably one that is hardly decomposed to some extent in view of the stability of the composition and the efficiency of radical polymerization initiation. The 10-hour half-life temperature of the peroxide alone is a guide for the ease of peroxide decomposition. The 10-hour half-life temperature is a temperature at which the decomposition of peroxide is measured while changing the temperature, and the temperature at which half of the peroxide is decomposed in 10 hours is determined. In this case, the higher the temperature, the less the thermal decomposition, and the lower the temperature, the easier the thermal decomposition. The peroxide used in the present invention preferably has a 10-hour half-life temperature of 80 ° C. or higher. Examples of such a peroxide include p-menthane hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, t-hexyl hydroperoxide, Organic piperooxides such as t-butyl hydroperoxide, bis (t-butylperoxy m-isopropyl) benzene, dicumyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) ) Dialkyl peroxides such as hexane, t-butylcumyl peroxide, di-t-butyl peroxide, 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexanone, 1,1-bis (T-butylperoxy) cyclohexane, 1,1-bis (t- Peroxyketals such as butylperoxy) cyclododecane, 2,2-bis (t-butylperoxy) butane, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane, t- Hexyl peroxyisopropyl monocarbonate, t-butylperoxymaleic acid, t-butylperoxy 3,3,5-trimethylhexanoic acid, t-butylperoxylauric acid, 2,5-dimethyl-2,5-bis ( m-toluoylperoxy) hexane, t-butylperoxyisopropyl monocarbonate, t-hexylperoxybenzoate, 2,5-dimethyl-bis (benzoylperoxy) hexane, t-butylperoxyacetic acid, t-butylperoxy Oxybenzoate, bis (t-butylperoxy) isophthalic acid and the like However, organic hydroperoxides are particularly preferred.
[0017]
In the present invention, the transition metal compound used in combination with the peroxide includes cobalt (II) chloride, cobalt (II) sulfate, cobalt (II) nitrate, cobalt (II) carbonate, cobalt (II) acetate, cobalt ( II) acetylacetonate, cobalt (III) acetylacetonate, cobalt (II) benzoate, cobalt (II) bromide, cobalt (II) chromate, cobalt (II) cyclohexylbutyrate, cobalt (II) octylate, glucone Cobalt (II) oxide, Cobalt (II) hydroxide, Cobalt (II) iodide, Cobalt (II) naphthenate, Cobaltcene (II), Cobalt monoxide (II), Cobalt (III) trioxide, Trioxide Cobalt (two or three), cobalt (II) phosphate, cobalt (II) stearate, cobalt sulfide (II), cobalt compounds such as cobalt (II) thiocyanate, ferrocene (II), ferrocene (II) carboxylic acid, iron (III) acetylacetonate, ammonium iron oxalate (III), iron (III) bromide, chloride Iron (II), iron (III) chloride, iron (III) citrate, iron (III) cyclohexylbutyrate, iron (III) diphosphate, iron (III) octylate, iron (II) fumarate, iron lactate ( II), iron (II) naphthenate, iron (III) nitrate, iron (II) oxalate, iron (III) oxide, iron (III) perchlorate, iron (III) phosphate, iron (II) sulfate, sulfide Iron compounds such as iron (II) and ammonium iron (III) oxalate, nickel (II) acetate, nickel (II) acetylacetonate, nickel (II) amide sulfate, nickel (II) bromide, charcoal Nickel (II), nickel chloride (II), nickel octylate (II), nickel formate (II), nickel hydroxide (II), nickel nitrate (II), nickelocene (II), nickel oxide (two, three), Nickel compounds such as nickel (II) perchlorate, potassium nickel (II) cyanide, nickel (II) sulfamate, nickel (II) sulfate, copper acetate (II), copper ammonium chloride (II), copper bromide ( I), Copper (II) bromide, Copper (I) chloride, Copper (II) chloride, Copper (II) citrate, Copper (I) cyanide, Copper (II) cyclohexylbutyrate, Copper (II) ammonium chloride Copper (II) diphosphate, copper (II) fluoride, copper (II) formate, copper (II) gluconate, copper (II) hydroxide, copper (I) iodide, copper (I) naphthenate, Copper (II) nitrate, e Copper (II) oleate, copper (II) oxalate, copper (I) oxide, copper (II) oxide, copper (II) phosphate, copper (II) phthalate, copper (II) potassium chloride, copper rhodanide ( I), copper compounds such as copper (II) sulfate, copper (II) sulfide, copper (II) terephthalate, copper (I) thiocyanate, vanadium (III) chloride, vanadium (IV) fluoride, vanadium naphthenate ( III), vanadium (IV) stearate, vanadium (IV) sulfate, vanadium (V) oxide, vanadium oxytrichloride, vanadium oxide acetylacetonate, vanadium oxalate, vanadium oxalate, and other vanadium compounds, cerium fluoride (III ), Cerium (IV) hydroxide, cerium (III) nitrate, cerium (IV) oxalate, cerium (IV) oxide, cerium (III) sulfate, Compounds such as cerium (IV) ammonium cerium, carbonyl molybdenum, molybdenum chloride (V), molybdenum (IV) oxide, molybdenum acetylacetonate, molybdenum (IV) sulfide, molybdic acid, 12-molybd (IV) phosphoric acid , Molybdenum compounds such as 12-molybdo (IV) silicic acid, tungsten chloride (VI), tungsten oxide (VI), sodium tungsten citrate, tungstic acid, 12-tungsto (VI) phosphoric acid, 12-tungsto (VI) silicon Acids, ammonium tungstate, ammonium tungstophosphate, tungsten compounds such as sodium 12-tungstate, potassium tungstate, calcium tungstate, etc., and in the present invention, cobalt compounds are particularly preferred. .
[0018]
In the present invention, when a peroxide and a transition metal compound are used in combination, the peroxide is 0.01 to 10% by mass, preferably 0.05 to 7% by mass, and particularly preferably 0.1 to 5% by mass. And 0.0001 to 5% by mass, preferably 0.001 to 3% by mass, particularly preferably 0.005 to 1% by mass of a transition metal compound. The ratio of the peroxide to the transition metal compound is not particularly limited, but the transition metal compound is preferably 0.001 to 1 part by mass, particularly preferably 0.01 to 0.1 part by mass, per 1 part by mass of the peroxide. use. Here, if the amount of the peroxide used is small, the curability is reduced, and if it is large, the physical properties of the cured product are reduced due to impurities derived from the peroxide. In addition, if the amount of the transition metal compound is small, the curability, particularly the surface curability, decreases, and if the amount is large, the stability of the composition decreases.
[0019]
In the present invention, in addition to the above-mentioned components, fillers, pigments, dyes, and various additives for improving weather resistance, preventing dripping, improving smoothness, and the like can be used as necessary. These materials are not particularly limited, but those that do not substantially affect the radical polymerizability are preferable. The amount used varies depending on the material used and its purpose, but the maximum amount of the filler is preferably 90% by mass or less, particularly preferably 80% by mass or less. Here, when the amount used is large, the ratio of the curable composition according to the present invention decreases, and the curability and the physical properties of the cured product decrease.
[0020]
【Example】
Hereinafter, the present invention will be described in more detail with reference to experimental examples including examples and comparative examples.
(Synthesis of Radical Polymerizable Monomer Containing Dicyclopentadienyl Structure)
(Experimental example: Synthesis example 1)
In a SUS reactor equipped with a stirrer, 132 parts of dicyclopentadiene and 130 parts of 2-hydroxyethyl methacrylate were mixed with 0.65 part of hydroquinone and 1.3 parts of 12-tungstophosphoric acid. And reacted for 10 hours. When the reaction product was analyzed by GC, the raw material almost completely disappeared and became one main product peak (separately identified as dicyclopentadienylethyl methacrylate), and was used as it was. This reaction product is designated as DCPDM-1.
(Experimental example: Synthesis example 2)
Using 86 parts of methacrylic acid instead of 2-hydroxyethyl methacrylate, 0.43 parts of hydroquinone and 0.86 parts of 12-tungstophosphoric acid were reacted in the same manner as in Synthesis Example 1. The obtained reaction product is designated as DCPDM-2.
[0021]
(Experimental example: Production of curable composition)
The components were weighed according to the formulation shown in Table 1 and uniformly mixed with a stirrer. Materials other than those shown in the synthesis examples are as follows.
PPG-1000 (manufactured by Nippon Emulsifier): polypropylene glycol (molecular weight 1000)
PPG-700 (manufactured by Nippon Emulsifier): polypropylene glycol (molecular weight 700)
Park Mill H-80 (manufactured by NOF Corporation): Park Mill Hydroperoxide (diluted with aromatic hydrocarbon; purity 80%)
Perhexa 3M (manufactured by NOF Corporation): 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexanone (purity 95%)
Cobalt (II) naphthenate (manufactured by Wako Pure Chemical Industries, Ltd.): Reagent, cobalt content about 6%
Cobalt octylate (II) (manufactured by Wako Pure Chemical Industries, Ltd.): reagent, cobalt 2-ethylhexanoate / cobalt content about 12%
Cobalt stearate (Wako Pure Chemicals reagent reagent): Reagent, chemical grade talc SS (manufactured by Nippon Talc): general-purpose talc, average particle size 8 μm
[0022]
[Table 1]

[0023]
(Experimental example: Preparation of cured coating)
Compositions 1 to 5 were applied to a 0.8 mm thick SPCC test piece (manufactured by Nippon Test Panel Co., Ltd.) using a 100 μm doctor blade. This was put into a blow dryer that was heated to 120 ° C., and was heated and cured for 10 minutes.
[0024]
(Experimental example: Preparation of cured product)
Compositions 1 to 5 were placed in a SUS mold having an inner diameter of 5 cm and a depth of 1.0 cm, and were cured by heating at 100 ° C. for 30 minutes. After cooling to room temperature, it was removed from the mold.
[0025]
(Experimental example: Characteristic evaluation)
(1) Curability: The cured film and the cured product were observed by appearance and finger touch.
Judgment criteria: ○ Good △ Surface tack present × Poor (2) Solvent resistance: The cured product was immersed in acetone and allowed to stand at room temperature for 24 hours.

(3) Water resistance: The cured coating film was immersed in ion-exchanged water and allowed to stand at 50 ° C. for 24 hours.

(4) Adhesion: The cured coating film was evaluated according to JIS K5400 8.5.2 (cross-cut tape method) at a clearance of 1 mm (square 100).
(5) Pencil hardness: The cured coating film was evaluated according to JIS K5400 8.4 (pencil scratch value).
(6) Impact resistance: The cured coating film was evaluated according to JIS K5400 8.3.2 (Dupont type impact resistance).
(7) Flex resistance: The breaking distance of the cured coating film was determined according to JIS K5400 8.2 (Erichsen value). (20 ° C)
[0026]
The results are shown in Table 2.
[0027]
[Table 2]

[0028]
【The invention's effect】
As is clear from the examples, according to the present invention, it is possible to produce a curable composition having excellent curability and capable of easily obtaining a cured film and a cured product which are flexible and have high strength.

Claims (4)

A curable composition containing 5 to 90% by mass of a radical polymerizable monomer having a dicyclopentadienyl structure and 1 to 50% by mass of a polyalkylene glycol. The curable composition according to claim 1, wherein the polyalkylene glycol is a block polymer having a weight average molecular weight of 300 to 5000 and containing at least 30% by mass of polypropylene glycol or a block having a polypropylene glycol structure. The curable composition according to claim 2, comprising 0.01 to 10% by mass of a peroxide having a 10-hour half-life temperature of 80C or more alone and 0.0001 to 5% by mass of a transition metal compound. The curable composition according to claim 3, wherein the peroxide is an organic hydroperoxide and the transition metal is cobalt.