Abstract: The present invention relates to a fiber-reinforced epoxy resin composite sheet comprising an epoxy resin film and reinforcing fibers laminated on one or both surfaces of the epoxy resin film, wherein in the reinforcing fibers, opened fibers are oriented in a predetermined direction, and a volume content Vf of the reinforcing fiber is 5 to 70%.

Abstract: A curable resin composition including components (A), (B), (C) and (D) below: component (A): a bisphenol epoxy resin with a softening point of 80° C. or more, component (B): a bisphenol epoxy resin which is liquid at 25° C., component (C): a bi- or more-functional (meth)acrylate compound, and component (D): a curing agent.

Abstract: A curable resin composition including components (A), (B), (C) and (D) below: component (A): a bisphenol epoxy resin with a softening point of 80° C. or more, component (B): a bisphenol epoxy resin which is liquid at 25° C., component (C): a bi- or more-functional (meth)acrylate compound, and component (D): a curing agent.

Abstract: A heat-curable epoxy resin composition is a mixture in which an epoxy compound represented by formula (al), a polyisocyanate, a bisphenol type liquid epoxy resin and an epoxy resin curing agent are blended. An amount of the epoxy compound, per 100 parts by mass of all the epoxy resin blended in the heat-curable epoxy resin composition, is 5 parts by mass or more.

Abstract: An epoxy resin composition includes an organic phosphinic acid metal salt; an epoxy resin; dicyandiamide or a derivative thereof; a curing accelerator having a dimethylureido group; and an imidazole-based curing accelerator having a curing initiation temperature of 100° C. or higher. The curing initiation temperature is measured by a method includes preparing a sample resin composition by adding 10 parts by mass of an imidazole-based curing accelerator to 100 parts by mass of a bisphenol A type epoxy resin having an epoxy equivalent of 180 to 220, and mixing the components; measuring a calorific value of the sample resin composition using a differential scanning calorimeter at a rate of temperature increase of 10° C./min, and designating a temperature at the intersection point of the tangent line at the inflection point of the DSC curve thus obtained and the baseline as the curing initiation temperature.

Abstract: A curable resin composition including components (A), (B), (C) and (D) below: component (A): a bisphenol epoxy resin with a softening point of 80° C. or more, component (B): a bisphenol epoxy resin which is liquid at 25° C., component (C): a bi- or more-functional (meth)acrylate compound, and component (D): a curing agent.

Abstract: The present invention pertains to a prepreg containing reinforcing fibers and an epoxy resin composition. Said prepreg is sandwiched between dies preheated to 140.degree.C. and pressurized to MPa and held for five minutes at this temperature to obtain a cured article having a G?Tg of at least 150.degree.C. The present invention also pertains to a fiber-reinforced composite material and a method for producing same. According to this invention, it is possible to provide a prepreg which is well suited to press-molding, particularly to high-cycle press-molding. It is also possible to provide a fiber-reinforced composite material which can be heat-cured at a lower temperature and over a shorter time than conventional methods, with which it is possible to minimize excessive flow of resin in hot-press curing, and which is resistant to performance defects such as fiber meandering and defects in surface appearance. A method for producing the same can also be provided.

Abstract: The present invention is an epoxy resin composition characterized by containing component A (epoxy resin containing sulfur atoms in the molecule thereof); and component B (an epoxy resin composition containing an imidazole compound represented by formula (1), and at least one of the following components: component C (an imidazole compound represented by formula (2) below) or component D (an epoxy resin composition having at least one sulfur atom in the molecule. According to the present invention, it is possible to provide an epoxy resin composition which has outstanding stability when stored at room temperature, and which can be heat-cured at a relatively low temperature and over a short time, to give a resin with a high heat resistance when cured. (In formula (1), R1 represents a straight-chain or branched-chain alkyl group having 1 to 5 carbon atoms, or a hydroxymethyl group, R2 represents a straight-chain or branched-chain alkyl group having 1 to 5 carbon atoms, or a hydrogen atom.

Abstract: An epoxy resin composition comprising the following Component (A), Component (B), Component (C), and Component (D): Component (A): an organic phosphinic acid metal salt; Component (B): an epoxy resin; Component (C): dicyandiamide or a derivative thereof; and Component (D): a curing accelerator having a dimethylureido group. The epoxy resin composition described above, further comprising the Component (E) which is an imidazole-based curing accelerator having a curing initiation temperature of 100° C. or higher as measured by the following method. Measurement method of a curing initiation temperature: a sample resin composition is prepared by adding 10 parts by mass of an imidazole-based curing accelerator to 100 parts by mass of a bisphenol A type epoxy resin having an epoxy equivalent of 180 to 220, and mixing the components. For this sample resin composition, the calorific value is measured using a differential scanning calorimeter (DSC) at a rate of temperature increase of 10° C.

Abstract: Provided is a method for producing a good epoxy resin composition for obtaining fiber-reinforced plastics. A production method for obtaining a fiber-reinforced composite material by impregnating a fiber assembly with an epoxy resin composition and then curing the epoxy resin composition, wherein the epoxy resin composition contains a component [A], a component [B] and a component [C] respectively satisfying the conditions described below. When the blending amount of the component [B] is set to b parts by mass and the blending amount of the component [C] is set to c parts by mass relative to 100 parts by mass of the component [A] contained in the epoxy resin composition, formula (2) is satisfied within the range of formula (1), formula (4) is satisfied within the range of formula (3), and formula (6) is satisfied within the range of formula (5).

Abstract: The present invention pertains to a prepreg containing reinforcing fibers and an epoxy resin composition. Said prepreg is sandwiched between dies preheated to 140.degree.C and pressurized to MPa and held for five minutes at this temperature to obtain a cured article having a G?Tg of at least 150.degree.C. The present invention also pertains to a fiber-reinforced composite material and a method for producing same. According to this invention, it is possible to provide a prepreg which is well suited to press-molding, particularly to high-cycle press-molding. It is also possible to provide a fiber-reinforced composite material which can be heat-cured at a lower temperature and over a shorter time than conventional methods, with which it is possible to minimize excessive flow of resin in hot-press curing, and which is resistant to performance defects such as fiber meandering and defects in surface appearance. A method for producing the same can also be provided.

Abstract: The present invention is an epoxy resin composition characterized by containing component A (epoxy resin containing sulfur atoms in the molecule thereof); and component B (an epoxy resin composition containing an imidazole compound represented by formula (1), and at least one of the following components: component C (an imidazole compound represented by formula (2) below) or component D (an epoxy resin composition having at least one sulfur atom in the molecule. According to the present invention, it is possible to provide an epoxy resin composition which has outstanding stability when stored at room temperature, and which can be heat-cured at a relatively low temperature and over a short time, to give a resin with a high heat resistance when cured. (In formula (1), R1 represents a straight-chain or branched-chain alkyl group having 1 to 5 carbon atoms, or a hydroxymethyl group, R2 represents a straight-chain or branched-chain alkyl group having 1 to 5 carbon atoms, or a hydrogen atom.

Abstract: Provided is a method for producing a good epoxy resin composition for obtaining fiber-reinforced plastics. A production method for obtaining a fiber-reinforced composite material by impregnating a fiber assembly with an epoxy resin composition and then curing the epoxy resin composition, wherein the epoxy resin composition contains a component [A], a component [B] and a component [C] respectively satisfying the conditions described below. When the blending amount of the component [B] is set to b parts by mass and the blending amount of the component [C] is set to c parts by mass relative to 100 parts by mass of the component [A] contained in the epoxy resin composition, formula (2) is satisfied within the range of formula (1), formula (4) is satisfied within the range of formula (3), and formula (6) is satisfied within the range of formula (5).