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 resin composition comprising 99.9 to 50% by weight of polyimide represented by the formula: ##STR1## and 0.1 to 50% by weight of polyether ketone resin and/or polyester resin, and more particularly comprising the polyester resin capable of forming an anisotropical molten phase at a temperature of 420.degree. C. or less, and a polyimide-based molding resin composition which comprises the said resins and other additives such as phenolic resin, fluororesin, graphite, carbon fibers, aromatic polyamide fibers, potassium titanate fibers and a crystallization accelerator, and is excellent in thermal resistance, chemical resistance, mechanical strength and processability.

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: A molding resin composition comprising 99.9 to 50% by weight of polyimide represented by the formula: ##STR1## and 0.1 to 50% by weight of polyether ketone resin and/or polyester resin, and more particularly comprising the polyester resin capable of forming an anisotropical molten phase at a temperature of 420.degree. C. or less, and a polyimide-based molding resin composition which comprises the said resins and other additives such as phenolic resin, fluororesin, graphite, carbon fibers, aromatic polyamide fibers, potassium titanate fibers and a crystallization accelerator, and is excellent in thermal resistance, chemical resistance, mechanical strength and processability.

Abstract: A molding resin composition comprising 99.9 to 50% by weight of polyimide represented by the formula: ##STR1## and 0.1 to 50% by weight of polyether ketone resin and/or polyester resin, and more particularly comprising the polyester resin capable of forming an anisotropical molten phase at a temperature of 420.degree. C. or less, and a polyimide-based molding resin composition which comprises the said resins and other additives such as phenolic resin, fluororesin, graphite, carbon fibers, aromatic polyamide fibers, potassium titanate fibers and a crystallization accelerator, and is excellent in thermal resistance, chemical resistance, mechanical strength and processability.

Abstract: A molding obtained by laminating resinous plates of 0.05 to 1 mm thick, prepared by impregnating 20% by volume or more of a reinforcing fiber with a thermoplastic resin, and molding the resultant laminate, wherein sections where deviation or deformation is caused by an external force, or preferably nonjoining parts having an area of 5 to 60% based on the area of the location where impact is absorbed, are provided between the laminated layers constituting the molding, or the laminated layer surface where the impact is absorbed is formed with a shape having a curvature of 5 to 20 mm in radius. The molding absorbs impact force significantly and prevents efficiently human body, etc. from the shock upon striking.

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 molding resin composition comprising 99.9 to 50% by weight of polyimide represented by the formula: ##STR1## and 0.1 to 50% by weight of polyether ketone resin and/or polyester resin, and more particularly comprising the polyester resin capable of forming an anisotropical molten phase at a temperature of 420.degree. C. or less, and a polyimide-based molding resin composition which comprises the said resins and other additives such as phenolic resin, fluororesin, graphite, carbon fibers, aromatic polyamide fibers, potassium titanate fibers and a crystallization accelerator, and is excellent in thermal resistance, chemical resistance, mechanical strength and processability.

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: Polyimide sheets having excellent thermal resistance and good surface appearance of the resultant sheets are obtained by a melt-extrusion process from a specific polyimide in the temperature range of 300.degree. C. to 450.degree. C. and a moisture content of 200 ppm or less.

Abstract: An insulated wire having excellent thermal resistance and good surface appearance is obtained by coating a condutor with a specific polyimide in a temperature range of 300.degree. C. to 450.degree. C. and controlling moisture content to 200 ppm or less.

Abstract: Integrated circuit sockets for use in a burn-in test are disclosed. The IC sockets are produced by injection molding of a specific polyimide having an inherent viscosity of 0.35 to 0.65 dl/g and essentially consisting of recurring units represented by the formula (I): ##STR1## wherein X is a radical selected from the group consisting of a bond, divalent hydrocarbon having from 1 to 10 carbon atoms, etc. and R is a tetravalent radical selected from the group consisting of an aliphatic radical having two or more carbon atoms, cycloaliphatic radical, monoaromatic radical etc.

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: Provided are carbon-fiber-reinforced polyimide resin compositions having excellent mechanical strength. The compositions are formed of (a) 5-50 parts by weight of carbon fibers, which have been obtained by coating starting carbon fibers at surfaces thereof with an aromatic polysulfone resin and then heating the thus-coated carbon fibers at 300.degree.-400.degree. C., and (b) 95-50 parts by weight of a polyimide resin which perferably have recurring units of following formula: ##STR1## wherein X represents a specific divalent radical and R represents a particular tetra-valent radical.

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.

Abstract: This invention relates to a process for preparing fiber-reinforced thermoplastic (FRTP) molded articles comprising stacking sheet prepregs comprising unidirectionally arranged reinforcing fibers impregnated with thermoplastic resin and molding the same, and to a process for preparing FRTP molded articles by using woven reinforcing fibers in place of unidirectionally arranged reinforcing fibers. The FRTP molded articles obtained by the process of this invention have high quality and can be molded without unevenness in strength.

Abstract: Thermoplastic polyimide foams are provided which essentially consist of recurring units represented by the formula (I): ##STR1## wherein X is a bond, divalent hydrocarbon radical having from 1 to 10 carbon atoms etc. and R is an aliphatic radical having 2 or more carbon atoms, cycloaliphatic radical etc.The foams have an apparent density of from 0.02 to 0.2 g/cc, average cell diameter of 0.1 to 1 mm and a closed cell content of 50% or more.

Abstract: Thermoplastic polyimide foams are provided which essentially consist of recurring units represented by the formula (I): ##STR1## wherein X is a bond, divalent hydrocarbon radical having from 1 to 10 carbon atoms etc. and R is an aliphatic radical having 2 or more carbon atoms, cycloaliphatic radical etc.The foams have an apparent density of from 0.02 to 0.2 g/cc, average cell diameter of 0.1 to 1 mm and a closed cell content of 50% or more.