Abstract: The present invention relates to a hybrid prepreg having reinforcing carbon fibers and foreign fibers. The carbon fibers have a diameter ranging from 5-30 microns and are unidirectionally arranged. The foreign fibers are composed either of single monofilaments having a diameter ranging from between about 50-150 microns or of strands formed by bundling together a plurality of single monofilaments having a diameter ranging from between about 5-50 microns. If strands are employed, they have a conversion diameter (D.sub.0) which is less than about 500 microns. The conversion diameter (D.sub.0) is represented by the following equation: ##EQU1## wherein n is the number of monofilaments used in forming the strand, and wherein d is the diameter of these monofilaments. Examples of foreign fibers which can be used when practicing this invention include boron fibers, metal fibers and organic fibers.

Abstract: A hybrid laminated prepreg is disclosed, which comprises a resin layer, a decorative layer laminated thereon and having a pattern, and a transparent prepreg layer laminated on the decorative layer. In manufacturing a fiber reinforced composite resin material molding, the hybrid prepreg is laminated in a couple of layers on the outermost one of laminated layers of usual prepreg. Thus, it is possible to easily decorate the obtainable molding to readily provide an aesthetic sense to the appearance of the molding and also dispense with time-consuming operation of coating or the like. Further, unlike the coating or the like, it is possible to stably hold the aesthetic sense of the appearance for long time.

Abstract: In the prepreg manufacuturing method according to the present invention, at least one of a first and second release papers is coated with a matrix resin having a low viscosity. Reinforcing fibers are supplied in between the release papers and arranged on the matrix resin layer. Then, the reinforcing fibers are impregnated with the matrix resin by heating and pressing the release papers. After separating one of the papers, a room-temperature curing type hardener is applied onto the matrix resin layer to form a high viscosity layer on a surface layer of the matrix resin layer. Thereafter, a cover film is laid over the surface layer to make a prepreg.

Abstract: An epoxy resin composition for forming prepregs is disclosed which includes an epoxy resin having at least two epoxy groups, a latent curing agent for the epoxy resin in an amount of 0.5-3.0 equivalents per equivalent of the epoxy groups of the epoxy resin, and a reactive, viscosity-increasing agent in an amount of 0.2-3.0 parts by weight per 100 parts by weight of the epoxy resin. The epoxy resin composition has an initial viscosity n.sub.I(50) at 50.degree. C. of 1,000-200,000 cP and an initial viscosity n.sub.I(23) at 23.degree. C. of at least 10,000 cP.

Abstract: A reinforcing fiber sheet is provided which includes a support sheet and reinforcing fibers. The fibers are arranged in one direction on at least one surface of the support sheet and attached thereto through an adhesive layer. There is also provided a method of reinforcing a structure, which includes arranging bundles of the reinforcing fibers in one direction on at least one surface of a support sheet in parallel apart from each other or close to each other, wherein the surface of the support sheet is coated with an adhesive layer. Thereafter, pressing the bundles against the support sheet such that the reinforcing fibers are adhered through the adhesive layer to the support sheet in one direction in a slightly unfastened state to thereby produce the reinforcing fiber sheet.

Abstract: A reinforcing fiber sheet is provided which includes a support sheet and reinforcing fibers. The fibers are arranged in one direction on at least one surface of the support sheet and attached thereto through an adhesive layer. There is also provided a method of reinforcing a structure, which includes impregnating reinforcing fibers of the fiber sheets with a room temperature-settable resin, attaching the resin-impregnated fiber sheets to a surface of the structure, and thereafter setting the room temperature-settable resin.

Abstract: The present invention relates to a hybrid prepreg having reinforcing carbon fibers and foreign fibers. The carbon fibers have a diameter ranging from 5-30 microns and are unidirectionally arranged. The foreign fibers are composed either of single monofilaments having a diameter ranging from between about 50-150 microns or of strands formed by bundling together a plurality of single monofilaments having a diameter ranging from between about 5-50 microns. If strands are employed, they have a conversion diameter (D.sub.0) which is less than about 500 microns. The conversion diameter (D.sub.0) is represented by the following equation: ##EQU1## wherein n is the number of monofilaments used in forming the strand, and wherein d is the diameter of these monofilaments. Examples of foreign fibers which can be used when practicing this invention include boron fibers, metal fibers and organic fibers.

Abstract: A flexible unidirectional glass prepreg comprising glass rovings having a thickness of 50 to 150 .mu.m and formed of glass fiber monofilaments having a diameter of 10 to 20 .mu.m and a matrix resin impregnated between the fiber monofilaments.

Abstract: In the production of a decorative sheet, a synthetic resin paste is first applied onto the upper surface of a substrate sheet to form an undercoat layer. Then, one or more pastes, each being of the same material and having approximately the same viscosity as the paste of the undercoat layer, are laterally sprayed so as to drop onto the undercoat layer. The result is a smoothing phenomenon, with the pattern layer cooperating with the undercoat layer to form a smooth patterned surface. Finally, the pattern layer is heated and jelled.