Abstract: A fuel cell gas diffusion layer includes: a porous carbon fiber base substrate containing discontinuous carbon fibers bonded to each other with carbide, and a porous layer containing at least carbonaceous particles, the porous carbon fiber base substrate having a porous layer (A) with a mean thickness t1 of 10 to 55 ?m deposited on one surface A thereof, the porous carbon fiber base substrate being impregnated with porous layer (J) at least part of which is exposed at an opposite surface B, the porous carbon fiber base substrate having internal pores with a cross-sectional area accounting for 5% to 40% of the total cross section in a through-plane direction, at least porous layer (A) and porous layer (J) both having a void percentage of 50% to 85%, the porous carbon fiber base substrate having a thickness of 60 to 300 ?m, and the porous carbon fiber base substrate having a bulk density of 0.20 to 0.45 g/cm3.

Abstract: A process for producing a sheet-shaped prepreg includes: a fiber bundle introduction step in which tape-shaped reinforcing fiber bundles are disposed in a multilayer arrangement in the thickness direction and introduced into a die to which a molten thermoplastic resin has been supplied; a fiber bundle thickness reduction step in which each of the tape-shaped reinforcing fiber bundles is widened by means of spreading to reduce the thickness; a resin impregnation step in which the tape-shaped reinforcing fiber bundles are impregnated with the molten resin in the die; and a lamination step in which the plurality of resin-impregnated tape-shaped reinforcing fiber bundles are laminated in the die.

Abstract: A fuel cell gas diffusion layer includes: a porous carbon fiber base substrate containing discontinuous carbon fibers bonded to each other with carbide, and a porous layer containing at least carbonaceous particles, the porous carbon fiber base substrate having a porous layer (A) with a mean thickness t1 of 10 to 55 ?m deposited on one surface A thereof, the porous carbon fiber base substrate being impregnated with porous layer (J) at least part of which is exposed at an opposite surface B, the porous carbon fiber base substrate having internal pores with a cross-sectional area accounting for 5% to 40% of the total cross section in a through-plane direction, at least porous layer (A) and porous layer (J) both having a void percentage of 50% to 85%, the porous carbon fiber base substrate having a thickness of 60 to 300 ?m, and the porous carbon fiber base substrate having a bulk density of 0.20 to 0.45 g/cm3.

Abstract: A composite prepreg base includes a raw prepreg base comprising a fiber sheet including discontinuous reinforcing fibers arranged in one direction and having a fiber length of 1-300 mm and a matrix resin infiltrated into the fiber sheet; and an additional resin layer formed on at least one surface of the raw prepreg base. The composite prepreg base is produced by a process including (i) the step of preparing the raw prepreg base and (ii) the step of forming an additional resin layer on at least one surface of the raw prepreg base prepared. A layered base includes two or more sheets of the composite prepreg base which have been superposed so that the additional resin layer is present on at least one surface; and a fiber-reinforced plastic formed by heating and pressing the layered base.

Abstract: A laminated base material includes a lamination and integration of prepreg base materials each of which includes many reinforcing fibers arranged substantially in one direction and a matrix resin adhered to the reinforcing fibers, wherein at least one of the laminated prepreg base materials is formed with a prepreg base material having, throughout its whole surface, many incisions each extending in a direction crossing the reinforcing fibers, substantially all of the reinforcing fibers divided by incisions, and wherein a length L of each of reinforcing fiber segments formed by the incisions is 10 to 100 mm, a thickness H of the prepreg base material is 30 to 300 ?m, and a fiber volume content Vf of the reinforcing fibers is 45 to 65% and arranging directions of the reinforcing fibers between one and another laminated prepreg base materials have at least two directions different each other.

Abstract: A thermoplastic resin prepreg includes: a constituent element (I): 20-60 parts by weight of a thermoplastic resin (A) having a linear or branched polymer structure; a constituent element (II): 2-10 parts by weight of a thermoplastic resin (B) which is unevenly distributed to a surface site and has a melting point lower than that of the thermoplastic resin (A); and a constituent element (III): 30-78 parts by weight of reinforcing fibers.

Abstract: The structural warp knit sheet provided by this invention is a warp knit sheet for spars or stringers which comprises: a warp knit structure constituted of chain-stitch structures configured of ground knitting yarns; longitudinal insertion yarns that have been inserted in the longitudinal direction into the warp knit structure, the longitudinal insertion yarns being continuous carbon fiber yarns; and transverse insertion yarns that have been inserted in directions along which the transverse insertion yarns shuttle between the adjacent chain-stitch structures, the chain-stitch structures having been united by means of the transverse insertion yarns. The longitudinal insertion yarns are carbon fiber yarns which each is composed of 12,000-50,000 filaments and has a tensile strength of 4 GPa or higher, a tensile modulus of 220-450 GPa, and a drape value of 4-22.

Abstract: A method of producing a carbon fiber aggregate cutting an edge material of a carbon fiber base material composed of carbon fibers to obtain a cut piece, and forming the cut piece into a web and/or into a nonwoven fabric to obtain a carbon fiber aggregate.

Abstract: A process for producing a sheet-shaped prepreg includes: a fiber bundle introduction step in which tape-shaped reinforcing fiber bundles are disposed in a multilayer arrangement in the thickness direction and introduced into a die to which a molten thermoplastic resin has been supplied; a fiber bundle thickness reduction step in which each of the tape-shaped reinforcing fiber bundles is widened by means of spreading to reduce the thickness; a resin impregnation step in which the tape-shaped reinforcing fiber bundles are impregnated with the molten resin in the die; and a lamination step in which the plurality of resin-impregnated tape-shaped reinforcing fiber bundles are laminated in the die.

Abstract: A composite prepreg base which includes a raw prepreg base comprising a fiber sheet comprising discontinuous reinforcing fibers arranged in one direction and having a fiber length of 1-300 mm and a matrix resin infiltrated into the fiber sheet; and an additional resin layer formed on at least one surface of the raw prepreg base. The composite prepreg base is produced by a process including (i) the step of preparing the raw prepreg base and (ii) the step of forming an additional resin layer on at least one surface of the raw prepreg base prepared. Also provided are: a layered base including two or more sheets of the composite prepreg base which have been superposed so that the additional resin layer is present on at least one surface; and a fiber-reinforced plastic formed by heating and pressing the layered base.

Abstract: A prepreg base material includes reinforcing fibers arranged substantially in one direction and a matrix resin between the reinforcing fibers, wherein the prepreg base material has substantially throughout its entire surface incisions, each incision extending in a direction substantially crossing the reinforcing fibers, wherein substantially all of the reinforcing fibers are divided by the incisions, a length (L) of each of reinforcing fiber segments formed by the incisions is in the range of 10 to 100 mm, a thickness H of the prepreg base material is in the range of 30 to 300 ?m, and a fiber volume content by Vf of the reinforcing fibers is in the range of 45 to 65%.

Abstract: A chopped fiber bundle includes a large number of unidirectionally arranged reinforced fibers. The length of each of the reinforced fibers is in the range of 5 to 100 mm. The chopped fiber bundle has a transition segment in which the number of the reinforced fibers increases toward the central part of the chopped fiber bundle in the aligned direction of the reinforced fibers with both ends in the aligned of the reinforced fibers in the chopped fiber bundle being a starting point. The level of a change in total sectional area of the large number of reinforced fibers is not more than 0.05 mm2 per mm in the aligned direction of the reinforced fibers over the whole area in the longitudinal direction of the chopped fiber bundle.

Abstract: A preform, formed with a plurality of reinforcing fiber substrates stacked to each other and each made of at least reinforcing fiber yarns, has a resin material, whose main component is a thermoplastic resin, interlaminated between the layers of the reinforcing fiber substrates in the preform, and has through holes extending through a plurality of the reinforcing fiber substrates in the thickness direction of the preform; an FRP molded using this preform; and processes for producing these. By improving the impregnability in the thickness direction of the preform, an FRP excellent both in various mechanical properties and in matrix resin impregnation and stabler in quality can be produced with high productivity.

Abstract: A fiber-reinforced plate-like plastic having a plate and a protrusion rising on the plate, wherein the plate and the protrusion each contain a laminated structure composed of plural reinforcing fiber sheets which each include many fibers of 10 to 100 mm in fiber length arranged in a fixed direction and at least two of the layers constituting the laminated structure are different in the direction of arrangement of reinforcing fibers and wherein at least part of the reinforcing fibers extend continuously from the plate to the protrusion and at least one of the layers constituting the laminated structure of the protrusion has a shape similar to the shape of the protrusion; and a process for the production of fiber-reinforced plastic which includes cutting a unidirectional prepreg sheet composed of many reinforcing fibers arranged in a fixed direction and a matrix resin into prepreg base material sheets with the above fiber length, laminating the prepreg base material sheets with the directions of arrangement of

Abstract: The present invention has an object of providing a method for producing a carbon fiber woven fabric in which the length of each warp yarn made of a carbon fiber strand is uniform, weft yarns are straightly arranged without waviness, and that is excellent in quality can be obtained with high productivity (production speed), and is characterized that a method for producing a carbon fiber woven fabric using an air jet loom in which heald in a shedding motion has an angle of repose in a range of 0 to 50° when weaving a uni-directional carbon fiber woven fabric woven with a carbon fiber strand having a fineness of 400 to 6,000 tex as the warp yarn and an auxiliary fiber having a fineness of ? or less of the carbon fiber strand as the weft yarn.

Abstract: A method for producing a reinforcing fiber woven fabric of the invention is a method for producing a reinforcing fiber 1 for weaving the reinforcing fiber as at least a warp 2. The yarn width of at least the warp 2 constituting the woven fabric is widened in the direction of the weft 3 by reciprocating cylindrical bodies 4 in the direction of the warp 2 of the woven fabric while rolling the cylindrical bodies 4 in a pressurization state to the woven fabric 1 A apparatus for producing a reinforcing fiber woven fabric of the invention comprising: a guide roller 5 which comes into contact with the surface of a reinforcing woven fabric continuously passing through at a predetermined winding angle and rotates; a plurality of cylindrical bodies 4 rotatably supported on the woven fabric which comes into contact with the surface of the guide roller 5; and driving parts 6 to 10 for reciprocating the cylindrical bodies in the direction of the warp 2 of the woven fabric.

Abstract: A chopped fiber bundle includes a large number of unidirectionally arranged reinforced fibers. The length of each of the reinforced fibers is in the range of 5 to 100 mm. The chopped fiber bundle has a transition segment in which the number of the reinforced fibers increases toward the central part of the chopped fiber bundle in the aligned direction of the reinforced fibers with both ends in the aligned of the reinforced fibers in the chopped fiber bundle being a starting point. The level of a change in total sectional area of the large number of reinforced fibers is not more than 0.05 mm2 per mm in the aligned direction of the reinforced fibers over the whole area in the longitudinal direction of the chopped fiber bundle.

Abstract: A composite prepreg base which includes a raw prepreg base comprising a fiber sheet comprising discontinuous reinforcing fibers arranged in one direction and having a fiber length of 1-300 mm and a matrix resin infiltrated into the fiber sheet; and an additional resin layer formed on at least one surface of the raw prepreg base. The composite prepreg base is produced by a process including (i) the step of preparing the raw prepreg base and (ii) the step of forming an additional resin layer on at least one surface of the raw prepreg base prepared. Also provided are: a layered base including two or more sheets of the composite prepreg base which have been superposed so that the additional resin layer is present on at least one surface; and a fiber-rein-forced plastic formed by heating and pressing the layered base.

Abstract: The present invention has an object of providing a method for producing a carbon fiber woven fabric in which the length of each warp yarn made of a carbon fiber strand is uniform, weft yarns are straightly arranged without waviness, and that is excellent in quality can be obtained with high productivity (production speed), and is characterized that a method for producing a carbon fiber woven fabric using an air jet loom in which heald in a shedding motion has an angle of repose in a range of 0 to 50° when weaving a uni-directional carbon fiber woven fabric woven with a carbon fiber strand having a fineness of 400 to 6,000 tex as the warp yarn and an auxiliary fiber having a fineness of ? or less of the carbon fiber strand as the weft yarn.

Abstract: A fiber-reinforced plate-like plastic having a plate and a protrusion rising on the plate, wherein the plate and the protrusion each contain a laminated structure composed of plural reinforcing fiber sheets which each include many fibers of 10 to 100 mm in fiber length arranged in a fixed direction and at least two of the layers constituting the laminated structure are different in the direction of arrangement of reinforcing fibers and wherein at least part of the reinforcing fibers extend continuously from the plate to the protrusion and at least one of the layers constituting the laminated structure of the protrusion has a shape similar to the shape of the protrusion; and a process for the production of fiber-reinforced plastic which includes cutting a unidirectional prepreg sheet composed of many reinforcing fibers arranged in a fixed direction and a matrix resin into prepreg base material sheets with the above fiber length, laminating the prepreg base material sheets with the directions of arrangement of