Abstract: A laminate body is provided which contains a thin prepreg having a component (A) containing a matrix of reinforcing fiber, a component (B) containing a thermosetting resin, and a component (C) containing particles of a thermoplastic resin. When molded and cured out of autoclave, the laminate body achieves a fiber-reinforced composite having a low void ratio and providing excellent mechanical performance.

Abstract: The void content of a cured fiber-reinforced composite material is advantageously reduced, particularly when the composite material article is large in size or fabricated using an out-of-autoclave procedure, by using prepreg sheets impregnated with a thermosettable resin composition containing thermoplastic particles and modified to have one or more characteristics such as a certain level of average surface roughness. Such characteristics may be imparted to the prepreg sheet by, for example, conditioning the prepreg sheet by subjecting it to vacuum conditions in advance of being consolidated and cured as part of a prepreg stack.

Abstract: The objective of the present invention is to provide a prepreg and a fiber reinforced composite material using this prepreg. This prepreg has good handleability, is suitable for producing a reinforced composite material in a short-time and without using an autoclave, and is capable of yielding a fiber reinforced composite material exhibiting excellent impact resistance, wherein the occurrence of voids has been suppressed. To attain the objective, this prepreg comprises a reinforced fiber [A] that is layered and partially impregnated with an epoxy resin composition containing an epoxy resin [B] and a hardener [C], the impregnation rate ? being 30 to 95%. In this prepreg, a thermoplastic resin [D] insoluble in the epoxy resin [B] is distributed unevenly over a surface on one side of the prepreg, and a portion not impregnated with the epoxy resin composition is localized in the layer of the reinforced fiber [A] on the side where the thermoplastic resin [D] is distributed unevenly.

Abstract: A laminate body is provided which contains a thin prepreg having a component (A) containing a matrix of reinforcing fiber, a component (B) containing a thermosetting resin, and a component (C) containing particles of a thermoplastic resin. When molded and cured out of autoclave, the laminate body achieves a fiber-reinforced composite having a low void ratio and providing excellent mechanical performance.

Abstract: The objective of the present invention is to provide a prepreg and a fiber reinforced composite material using this prepreg. This prepreg has good handleability, is suitable for producing a reinforced composite material in a short-time and without using an autoclave, and is capable of yielding a fiber reinforced composite material exhibiting excellent impact resistance, wherein the occurrence of voids has been suppressed. To attain the objective, this prepreg comprises a reinforced fiber [A] that is layered and partially impregnated with an epoxy resin composition containing an epoxy resin [B] and a hardener [C], the impregnation rate ? being 30 to 95%. In this prepreg, a thermoplastic resin [D] insoluble in the epoxy resin [B] is distributed unevenly over a surface on one side of the prepreg, and a portion not impregnated with the epoxy resin composition is localized in the layer of the reinforced fiber [A] on the side where the thermoplastic resin [D] is distributed unevenly.