Abstract: Curable resin composition comprising a compound (A) having one or more maleimide groups within the molecule thereof, and vinlbenzyl compound (B) obtained by reacting amines with halomethylstyrene in the presence of alkali.The composition exhibits excellent low-temperature curability, heat resistance and mechanical strength.

Abstract: A thermoset resin composition comprises a compound (A) having one or more maleimido groups in its molecule and at least one vinylbenzyl ether compound (B) selected from the group consisting of compounds (B.sub.1) having at least two vinylbenzyl ether groups bonded to a naphthalene nucleus in its molecule and compounds (B.sub.2) having at least two vinylbenzyl ether groups bonded to a benzene nucleus having at least one substituent selected from the group consisting of hydroxyl groups, alkyl groups and alkoxy groups in its molecule.The composition exhibits excellent low-temperature curing properties, heat resistance and mechanical strength.

Abstract: A curable composition for a fiber-reinforced resin, comprises (A) 60-90 weight % of an epoxy-containing (meth)acrylate resin which contains an epoxy group and an unsaturated-monobasic acid ester group in its molecules and which is formed by the reaction of an epoxy resin containing at least two epoxy groups per molecule and having an epoxy equivalent of 100-1000 with an unsaturated-monobasic acid in an amount such that there are 0.2-0.7 equivalents of carboxyl groups per 1 equivalent of epoxy groups, (B) 40-10 weight % of a radical polymerizable monomer, (C) an organic peroxide, (D) a curing agent for the epoxy resin, and (E) one or more reinforcing materials selected from continuous fiber and fiber cloth.

Abstract: The present invention provides a resinous composition of modified phenolic compounds comprising a phenolic compound and an unsaturated cycloacetal, the composition being curable with an active energy rays, the improvement residing in the use of an onium salt. The cured material has no appreciable odor of acrolein and is stable in storage.

Abstract: This invention relates to a curable resin composition suitable for use in the applications of casting material, coating material, putty, adhesives, various types of linings and FRP, said curable resin composition being characterized in that an unsaturated acrylic urethane prepared by addition reaction of a hydroxyl-terminated polymer, a polyisocyanate and a monohydroxylalkyl monoacrylate or a monohydroxylalkyl monomethacrylate, substantially free from an isocyanate group and having a weight-average extension of molecular chain of 100 A or more is added to at least one of an unsaturated polyester resin and an epoxy acrylate resin in an amount effective for the development of toughness, thus the toughness of the conventional unsaturated polyester or epoxyacrylate ester being improved by admixing said unsaturated acrylic urethane therewith.

Abstract: This invention relates to a method for improving surface properties of a porous inorganic material, which comprises coating said material with an infiltratable photopolymerizable paint containing unsaturated spiroacetal resin as one or more layers in environmental atmosphere to infiltrate said paint into said material and then exposing the resultant material to ultraviolet radiation.

Abstract: This invention relates to a resinous composition curable to an insoluble and infusible resin, which comprises: (i) a compound having at least 2 or more unsaturated cycloacetal groups per molecule, expressed by the formula, ##STR1## (ii) a compound having at least 2 or more mercapto groups (--SH) per molecule, said compound (i) and compound (ii) being mixed in the functional group ratio of 1 : 0.5 - 1.7 and the average total number of the unsaturated cycloacetal groups and mercapto groups being 4 or more.

Abstract: This invention relates to a method for preparing paper board having excellent wet tensile strength and compression strength, which comprises (a) having paper board impregnated or coated with a mixture of an unsaturated vinyl ester prepolymer having a molecular weight of 300 to 3000 and having at least one hydroxyl group at the .beta.-position with respect to an ester bond in the molecule with at least one monomer selected from the group of methylacrylate, ethylacrylate and butylacrylate in a mixing weight ratio of 10:90-40:60, and (b) irradiating the paper board having the resinous mixture with electrons to cure the resinous mixture.

Abstract: This invention relates to a curable resinous composition prepared by reacting 1 mol of (a) an unsaturated polycycloacetal, 0.1 to 3 mols of (b) an ester of polyhydric alcohol/unsaturated monocarboxylic acid, having an alcoholic hydroxyl group and a polymerizable unsaturated bond selected from the group of acryl and methacryl groups in the same molecule, and 0.1 to 2.9 mols (per hydroxyl group in component b) of (c) a polyhydroxy compound.

Abstract: This invention relates to a curable resinous composition which comprises a combination of (I) a curable resinous compound prepared by reacting 1 mol of (a) an unsaturated polycycloacetal, 0.1 to 3 mols of (b) an ester of a polyhydric alcohol/unsaturated monocarboxylic acid, having an alcoholic hydroxyl group and a polymerizable unsaturated bond in the same molecule, and 0 to 2.9 mols of (c) a polyhydroxy compound such as polyols, polyethers and polyesters, with (II) an unsaturated polyester.

Abstract: This invention relates to a polymerizable cycloacetal resinous composition, characterized by reacting 1 equivalent of diallylidenepentaerythritol (I) with 0.8 - 2.0 equivalents of polyhydric alcohol-unsaturated monocarboxylic acid ester mono-ol (II) having both a hydroxyl group and a polymerizable or copolymerizable unsaturated bond in the same molecule, with or without a solvent, in the presence of a polymerization inhibitor and addition reaction catalyst.

Abstract: This invention relates to a polymerizable cycloacetal resinous composition, characterized by reacting 1 equivalent of diallylidenepentaerythritol (I) with 0.8 - 2.0 equivalents of polyhydric alcohol-unsaturated monocarboxylic acid ester mono-ol (II) having both a hydroxyl group and a polymerizable or copolymerizable unsaturated bond in the same molecule, with or without a solvent, in the presence of a polymerization inhibitor and addition reaction catalyst.