Abstract: A process for preparing a molded article of fiber-reinforced plastic having an optional configuration and no tendency to deformation and cracks by using a plate material consisting essentially of a fibrous reinforcement and a thermoplastic resin, comprising the steps of previously setting-up, on the plate material and/or a mold, a sheet prepreg obtained by impregnating a unidirectionally arranged fiber or woven cloth with a thermoplastic resin in areas where the fibrous reinforcement does not follow the flow of the resin well or in areas where special reinforcement is required and successively carrying out integral molding to obtain said article; and a molded article obtained by said process.

Abstract: A molding material shaped like a plate and comprising a composite of continuous fibers and thermoplastic resin wherein each of the filaments which form the continuous fiber is coated around the surface thereof with the thermoplastic resin. Although the molding material has a high density of reinforcing fibers therein, it provides excellent distribution of fibers in the molding process; few of its fibers are broken, and its mechanical strength is considerably enhanced when its specific surface is made larger than a certain value. This molding material can be used for injection, extrusion and compression moldings.

Abstract: Method and apparatus for manufacturing a sheet-prepreg reinforced with fibers wherein a sheet of fibers such as warp or woven fibers such as fabrics is conveyed between a pair of band belts one of which is coated with a film of thermoplastic resin which has been heated higher than its softening point to enhance resin-impregnating efficiency and prevent the impregnated resin from contacting air. Further, when the sheet of fibers or woven fibers is conveyed in this manner, the molten resin is not maintained on the manufacturing line, thereby preventing it from being deteriorated by heat. The apparatus can be thus kept under operation for a long time and the sheet-prepreg reinforced with the fibers can be made much higher in quality and the deterioration of the impregnated resin can be further delayed.

Abstract: A process for preparing a molded article of fiber-reinforced plastic having an optional configuration and no tendency to deformation and cracks by using a plate material including a fibrous reinforcement and a thermoplastic resin, including the steps of previously setting-up, on the plate material and/or a mold, a sheet prepreg obtained by impregnating a unidirectionally arranged fiber or woven cloth with a thermoplastic resin in areas where the fibrous reinforcement does not follow the flow of the resin well or in areas where special reinforcement is required and successively carrying out integral molding to obtain said article; and a molded article obtained by the process.

Abstract: Method and apparatus for manufacturing a sheet-prepreg reinforced with fibers wherein a sheet of fibers such as warp or woven fibers such as fabrics is conveyed between a pair of band belts one of which is coated with a film of thermoplastic resin which has been heated higher than its softening point to enhance resin-impregnating efficiency and prevent the impregnated resin from contacting air. Further, when the sheet of fibers or woven fibers is conveyed in this manner, the molten resin is not maintained on the manufacturing line, thereby preventing it from being deteriorated by heat. The apparatus can be thus kept under operation for a long time and the sheet-prepreg reinforced with the fibers can be made much higher in quality and the deterioration of the impregnated resin can be further delayed.

Abstract: This invention relates to a method for preparing a polyimide having good heat-stability and excellent flowability in a molten state.The polymide is prepared by reacting aromatic diamines such as 4,4'-bis(3-aminophenoxy)biphenyl, bis[4-(3-aminophenoxy)phenyl] ketone and bis [4-(3-aminophenoxy)phenyl] sulfone; tetracarboxylic dianhydrides such as pyromellitic dianhydride, 3,3', 4,4'-benzophenonetetracarboxylic dianhydride and bis(3,4-dicarboxyphenyl) ether dianhydride; and dicarboxylic anhydrides such as glutaric anhydride, 1,2-hexanedicarboxylic anhydride, phthalic anhydride and 3,4-benzophenonedicarboxylic anhydride. The molar ratio of aromatic diamine: tetracarboxylic dianhydride: dicarboxylic anhydride is 1:(0.9 to 1.0):(0.001 to 1.0).The invention also relates to polyimide composite materials which are excellent in mechanical strengths and processability.

Abstract: The invention relates to processes for preparing a polyimide, a polyimide composition prepared by the processes and polyimide composite materials containing the same.