Abstract: The method includes: a) a step of stacking and shaping a prepreg according to the shape of a surface of the structure; b) a step of vacuum-pressurizing the stacked and shaped prepreg; c) a step of heating and curing the vacuum-pressurized prepreg to produce a cured product of the prepreg; and d) a step of bonding the cured product to the surface of the structure. The prepreg includes: a resin composition including an ethylenically unsaturated group-containing resin (A) and a polymerization initiator (B); and reinforcement fibers (C). The polymerization initiator (B) has a 10-hour half-life temperature of 60° C. to 75° C. This method for reinforcing and repairing the structure allows a structure having excellent workability and excellent mechanical strength to be obtained.

Abstract: Provided is a prepreg including: a resin composition including a urethane (meth)acrylate (A), a polymerization initiator (B), and an amine catalyst (C); and reinforcement fibers (D). The urethane (meth)acrylate (A) is a reaction product of a polyisocyanate compound (al) and a hydroxyl group-containing compound (a2), the polyisocyanate compound (a1) including polymethylene polyphenyl polyisocyanate and diphenylmethane diisocyanate, the hydroxyl group-containing compound (a2) including a compound having a hydroxyl group and a (meth)acryloyl group.

Abstract: Provided is a prepreg resin composition, containing: a urethane (meth)acrylate (A) that is a reaction product of polyisocyanate (a1), polyol (a2), and hydroxy alkyl (meth)acrylate (a3); a polymerization initiator (B); and a thermoplastic resin (C), as an essential component, in which the polyisocyanate (a1) is at least one polyisocyanate selected from 2,4?-diphenyl methane diisocyanate, 4,4?-diphenyl methane diisocyanate, a carbodiimide modified product of 4,4?-diphenyl methane diisocyanate, and polymethylene polyphenyl polyisocyanate. The prepreg resin composition of the invention is excellent in molding properties, and is capable of forming a molded article excellent in various physical properties such as flexibility, impact resistance, and heat resistance, and thus, can be preferably used in a prepreg and a molded article thereof.

Abstract: Provided is a method for manufacturing a molded article obtained by double belt press molding a thermosetting prepreg, in which the thermosetting prepreg is coated with a release film during molding, and a width of the prepreg is 1 to 25 mm smaller than that of the release film. This manufacturing method suppresses burr generation and fiber twisting, and is excellent in width restriction, and thus can be suitably used for, for example, automobile members, railroad vehicle members, aerospace machine members, ship members, household equipment members, sporting goods members, light vehicle members, building and civil engineering members, and housings for OA equipment and the like.

Abstract: The present invention provides a prepreg including a radical polymerizable resin composition, containing at least a radical polymerizable resin and a polymerization initiator, and a fiber substrate. The prepreg is characterized in that both surfaces of the prepreg are coated with a film having an oxygen permeability of 200 (ml/m2·24 h·atm) or less. The prepreg can suppress the delay of the proceeding of curing reaction after storage at room temperature, can allow curing reaction to properly proceed during heating of the prepreg, can suppress the occurrence of a molding defect, and can produce a molded product having excellent workability, and thus can be preferably used for an automobile member, a rail vehicle member, an aerospace plane member, a civil engineering and construction member, a casing of an OA device, and the like, and can be particularly preferably used for an automobile member, a housing equipment member, a sport member, etc.

Abstract: Provided is a prepreg containing a urethane (meth)acrylate (A), a polymerization initiator (B), and reinforcement fibers (C), characterized in that the polymerization initiator (B) is an alkyl peroxy ester compound having a 10-hour half-life temperature of 60° C. or higher and lower than 70° C. The prepreg has excellent storage stability and excellent moldability, even under the low-temperature molding condition of 110° C. or lower, and enables to obtain a molded article having excellent physical properties such as interlaminar shear strength. Therefore, the prepreg can be suitably used in automobile components, railway vehicle components, aerospace craft components, ship components, housing equipment components, sporting components, light vehicle components, building and civil engineering components, and casings of OA equipment and the like.

Abstract: Provided is a prepreg containing a urethane (meth)acrylate (A), an ethylenically unsaturated monomer (B), a polymerization initiator (C), and reinforcement fibers (D), characterized in that the urethane (meth)acrylate (A) is a reaction product of a polyisocyanate (a1) and a polyol (a2) having an ethylenically unsaturated group and an aromatic skeleton, and/or a reaction product of a polyisocyanate (a1), a polyol (a3) not having an ethylenically unsaturated group but having an aromatic skeleton, and a hydroxyalkyl (meth)acrylate (a4), and that the ethylenically unsaturated monomer (B) has a molecular weight of 320 or more and a weight reduction rate (%) of less than 2 when heated under atmospheric pressure at 150° C. for 3 minutes. The prepreg has excellent moldability and enables to produce a molded article having excellent physical properties such as flexural strength and interlaminar shear strength, and therefore the prepreg can be suitably used in automobile components and the like.

Abstract: Provided is a prepeg resin composition, containing: a urethane (meth)acrylate (A) that is a reaction product of polyisocyanate (a1), polyol (a2), and hydroxy alkyl (meth)acrylate (a3); and a polymerization initiator (B), as an essential component, in which the polyisocyanate (a1) is at least one polyisocyanate selected from 2,4?-diphenyl methane diisocyanate, 4,4?-diphenyl methane diisocyanate, a carbodiimide modified product of 4,4?-diphenyl methane diisocyanate, and polymethylene polyphenyl polyisocyanate, and the polyol (a2) has an aromatic-ring and an oxyalkylene structure. The prepreg resin composition of the invention is excellent in workability and molding properties, and is capable of forming a molded article excellent in various physical properties such as external appearance and heat resistance, and thus, can be preferably used in a prepreg and a molded article thereof.

Abstract: Provided is a prepreg resin composition, containing: a urethane (meth)acrylate (A) that is a reaction product of polyisocyanate (a1), polyol (a2), and hydroxy alkyl (meth)acrylate (a3); a polymerization initiator (B); and a thermoplastic resin (C), as an essential component, in which the polyisocyanate (a1) is at least one polyisocyanate selected from 2,4?-diphenyl methane diisocyanate, 4,4?-diphenyl methane diisocyanate, a carbodiimide modified product of 4,4?-diphenyl methane diisocyanate, and polymethylene polyphenyl polyisocyanate. The prepreg resin composition of the invention is excellent in molding properties, and is capable of forming a molded article excellent in various physical properties such as flexibility, impact resistance, and heat resistance, and thus, can be preferably used in a prepreg and a molded article thereof.

Abstract: Provided is a prepreg including: a urethane (meth)acrylate that is a reaction product of a polyisocyanate compound comprising a polymethylene polyphenyl polyisocyanate as an essential component with a hydroxyl group-containing compound comprising, as an essential component, a compound having a hydroxyl group and a (meth)acryloyl group; a polymerization initiator; and carbon fibers. The prepreg is excellent in workability and molding property and can form molded products excellent in various physical properties such as interlayer shear strength and heat resistance. Thus, the prepreg is suitable for use in various molded articles including automotive members.

Abstract: Provided is a prepeg resin composition, containing: a urethane (meth)acrylate (A) that is a reaction product of polyisocyanate (a1), polyol (a2), and hydroxy alkyl (meth)acrylate (a3); and a polymerization initiator (B), as an essential component, in which the polyisocyanate (a1) is at least one polyisocyanate selected from 2,4?-diphenyl methane diisocyanate, 4,4?-diphenyl methane diisocyanate, a carbodiimide modified product of 4,4?-diphenyl methane diisocyanate, and polymethylene polyphenyl polyisocyanate, and the polyol (a2) has an aromatic-ring and an oxyalkylene structure. The prepreg resin composition of the invention is excellent in workability and molding properties, and is capable of forming a molded article excellent in various physical properties such as external appearance and heat resistance, and thus, can be preferably used in a prepreg and a molded article thereof.

Abstract: Provided is a sheet winding molding method including winding a thermosetting prepreg around a substrate while heating the thermosetting prepreg, wherein the time taken to form a next layer of the thermosetting prepreg on a layer of the wound thermosetting prepreg is shorter than the gel time of the prepreg at the temperature of the wound thermosetting prepreg. The sheet winding molding method is advantageous not only in that the method has excellent productivity, but also in that a molded article having excellent physical properties, such as excellent interlaminar shear strength, can be obtained by the method.

Abstract: Provided is a prepreg including: a urethane (meth)acrylate that is a reaction product of a polyisocyanate compound comprising a polymethylene polyphenyl polyisocyanate as an essential component with a hydroxyl group-containing compound comprising, as an essential component, a compound having a hydroxyl group and a (meth)acryloyl group; a polymerization initiator; and carbon fibers. The prepreg is excellent in workability and molding property and can form molded products excellent in various physical properties such as interlayer shear strength and heat resistance. Thus, the prepreg is suitable for use in various molded articles including automotive members.

Abstract: Provided is a prepreg containing a urethane-modified epoxy (meth)acrylate (A) that is a reaction product of an epoxy (meth)acrylate (a1) having an average of 1.8 to 2.6 hydroxy groups and a polyisocyanate (a2) having an average of 2 to 3 isocyanate groups, an ethylenically unsaturated monomer (B), a polymerization initiator (C), and reinforcing fibers (D) as essential components, in which the molar ratio (NCO/OH) of isocyanate groups (NCO) in the polyisocyanate (a2) to hydroxy groups in the epoxy (meth)acrylate (a1) is 0.6 to 1.1, and the proportion of the ethylenically unsaturated monomer (B) in the total mass of the epoxy (meth)acrylate (a1) and the ethylenically unsaturated monomer (B) is 10% to 50% by mass. The prepreg has good workability and good moldability and can be appropriately used for various molded articles such as automotive members because various excellent physical properties such as interlaminar shear strength and heat resistance are provided.

Abstract: The two-part curable polyurethane foam resin composition uses little or no petroleum-derived raw materials but a plant-derived raw material so that the biomass ratio can be improved, the load on the environment can be reduced, and excellent physical characteristics can be exhibited. The two-part curable polyurethane foam resin composition includes a main agent that contains an isocyanate-terminated urethane prepolymer (A) and a curing agent that contains an isocyanate-reactive compound (B), water (C), and a catalyst (D), in which a polyol component used in (A) and (B) uses a castor oil polyol (b1) having 1.5 to 2.3 functional groups on average and a polyol (b2) prepared by addition polymerization of lactone to polytetramethylene glycol and/or polytetramethylene glycol (b3), the ratio (b1)/(b2) and/or (b3)=15/85 to 60/40 on a mass basis, and a content of the castor oil polyol (b1) is 10 to 45% by mass.

Abstract: The present invention relates to a two-component urethane resin composition for a polishing pad including a base resin containing an isocyanate group-terminated urethane prepolymer (A) and a curing agent containing an isocyanate group reactive compound (B), and characterized in that the prepolymer (A) is a prepolymer having an isocyanate group equivalent of 250 to 700 and being produced by reacting a polyisocyanate (a1) with an aromatic polyester polyol (a2) and a polyether polyol (a3) which are used as polyol components in combination at a mass ratio of (a2)/(a3)=5/95 to 70/30, and the aromatic polyester polyol (a2) has 2 to 11 aromatic rings in its molecular chain, and also relates to a polyurethane polishing pad using the resin composition and a method for producing a polyurethane polishing pad.

Abstract: The two-part curable polyurethane foam resin composition uses little or no petroleum-derived raw materials but a plant-derived raw material so that the biomass ratio can be improved, the load on the environment can be reduced, and excellent physical characteristics can be exhibited. The two-part curable polyurethane foam resin composition includes a main agent that contains an isocyanate-terminated urethane prepolymer (A) and a curing agent that contains an isocyanate-reactive compound (B), water (C), and a catalyst (D), in which a polyol component used in (A) and (B) uses a castor oil polyol (b1) having 1.5 to 2.3 functional groups on average and a polyol (b2) prepared by addition polymerization of lactone to polytetramethylene glycol and/or polytetramethylene glycol (b3), the ratio (b1)/(b2) and/or (b3)=15/85 to 60/40 on a mass basis, and a content of the castor oil polyol (b1) is 10 to 45% by mass.

Abstract: The present invention relates to a two-component urethane resin composition for a polishing pad including a base resin containing an isocyanate group-terminated urethane prepolymer (A) and a curing agent containing an isocyanate group reactive compound (B), and characterized in that the prepolymer (A) is a prepolymer having an isocyanate group equivalent of 250 to 700 and being produced by reacting a polyisocyanate (a1) with an aromatic polyester polyol (a2) and a polyether polyol (a3) which are used as polyol components in combination at a mass ratio of (a2)/(a3)=5/95 to 70/30, and the aromatic polyester polyol (a2) has 2 to 11 aromatic rings in its molecular chain, and also relates to a polyurethane polishing pad using the resin composition and a method for producing a polyurethane polishing pad.