Abstract: This invention relates to a flame retardant epoxy resin composition which includes an epoxy resin structure having an epoxy functionality of 2 or more with a measured total heat release value of not more than 23 kJ/g as well as an organic phosphinic acid structure (in reacted or unreacted form), as well as a prepreg, and a fiber reinforced composite material prepared using the epoxy resin composition. More specifically, an epoxy resin composition is provided that contains a combination of particular types of epoxy resins and curatives that provide sufficient flame retardance when cured at 163° C. for 15 minutes. The epoxy resin systems are also suitable for preparing a fiber-reinforced composite material that will also provide sufficient flame retardance for a variety of applications.

Abstract: This invention relates to a flame retardant fiber-reinforced composite material based on an epoxy resin composition which includes at least one epoxy resin having an epoxy functionality of at least 2 as well as at least one organic phosphinic acid or derivative thereof (e.g., an organic phosphinic acid-modified epoxy resin), reinforced with a fiber having a thermal conductivity?3 W/m·K at room temperature, as well as a prepreg for making such a flame retardant fiber-reinforced composite material. More specifically, a composite material is provided that contains a combination of particular types of epoxy resins, curatives, and reinforcing fibers that provide sufficient flame retardance for thin-ply laminates when cured at 163° C. for 15 minutes. These cured composites are also suitable for a variety of applications requiring flame retardancy.

Abstract: A prepreg is provided. The prepreg includes sizing agent-coated carbon fibers and a thermosetting resin composition (B) impregnated between the sizing agent-coated carbon fibers. The sizing agent includes a reactive component (A) having at least three reactive groups per molecule: (i) two or more first functional groups capable of reacting with the thermosetting resin composition (B), and (ii) at least one second functional group different from the two or more first functional groups (i). The second functional group includes at least one of amide, imide, urethane, urea, carbonyl, ester, sulfonyl, aromatic ring, or combinations thereof. The thermosetting resin composition (B) includes at least one thermosetting resin other than an epoxy resin and has a glass transition temperature of 220° C. or more after being cured.

Abstract: A fiber reinforced prepreg comprising reinforcement fibers; particles (D1) and (D2); and a thermosetting resin composition is provided. The resin includes maleimide compound (A), and co-monomer (B). Co-monomer (B) has least one of an alkenylphenol, an alkenylphenoxy, or a diamine group. Particles (D1) are smaller than (D2) and particles (D1) and (D2) are insoluble in the thermosetting resin. Particles (D1) range in diameter from 1 to 10 microns and have a mode on a volume basis from 3 to 6 microns and are present from 3 to 12 percent by volume of the thermosetting resin. Particles (D2) range from 10 to 100 microns diameter and a mode of 20 to 60 microns and are present from 1 to 6 percent by volume of the thermosetting resin composition. After cure, at least 90% by volume of particles (D1) and (D2) remain in the prepreg interlayers.

Abstract: A prepreg having excellent tackiness as well as excellent resin strength after curing and strength in the non-fiber direction is described; and a fiber-reinforced composite material using the prepreg, where the prepreg is composed of reinforcing fibers and a resin composition which includes [A] an epoxy resin, [B] a dicyanamide and [C] a compound having a melting point of 130° C. or lower and a solubility parameter whose difference from the solubility parameter of [B] is 8 or less.

Abstract: A curable benzoxazine resin composition for a fiber-reinforced composite material is provided which contains at least a component [A], a component [B], and a component [C]. The component [A] includes at least one multifunctional benzoxazine resin having a non-hydrocarbon linkage such as carbonyl, oxygen, sulfur, sulfone or sulfoxide between aromatic moieties. The component [B] includes at least one multifunctional benzoxazine resin having a direct bond or a hydrocarbon linkage between aromatic moieties. The component [C] includes at least one cycloaliphatic epoxy resin containing at least two epoxy groups which are part of cycloaliphatic rings. The curable benzoxazine resin composition is useful in the molding of fiber-reinforced composite materials.

Abstract: The purpose of the present invention is to provide: a method for producing a gas diffusion electrode base which enables the achievement of a gas diffusion electrode base that has a microporous layer with small surface roughness and is not susceptible to damaging an electrolyte membrane; and a gas diffusion electrode base that has a microporous layer with small surface roughness and is not susceptible to damaging an electrolyte membrane. For the purpose of achieving the above-described purpose, the present invention has the configuration described below. Namely, a specific gas diffusion electrode base which has a carbon sheet and a microporous layer, and wherein the carbon sheet is porous and the DBP oil absorption of a carbon powder contained in the microporous layer is 70-155 ml/100 g.

Abstract: A prepreg having excellent tackiness as well as excellent resin strength after curing and strength in the non-fiber direction is described; and a fiber-reinforced composite material using the prepreg, where the prepreg is composed of reinforcing fibers and a resin composition which includes [A] an epoxy resin, [B] a dicyanamide and [C] a compound having a melting point of 130° C. or lower and a solubility parameter whose difference from the solubility parameter of [B] is 8 or less.

Abstract: Provided is a fiber-reinforced composite material exhibiting high heat resistance and excellent appearance quality. is the composite material is based on an epoxy resin composition which contains constituents [A], [B], and [C] and satisfies conditions (i) and (ii): [A] a tri- or higher functional epoxy resin; [B] an aromatic amine; [C] an imidazole compound; 0.20?b/a?0.60; and??(i) 0.002?c/a?0.014;??(ii) wherein a (mol) denotes the number of epoxy groups in 100 g of the epoxy resin composition, b (mol) denotes the number of active hydrogens contained in the constituent [B], and c (mol) denotes the number of imidazole rings contained in the constituent [C]).

Abstract: The purpose of the present invention is to provide: a method for producing a gas diffusion electrode base which enables the achievement of a gas diffusion electrode base that has a microporous layer with small surface roughness and is not susceptible to damaging an electrolyte membrane; and a gas diffusion electrode base that has a microporous layer with small surface roughness and is not susceptible to damaging an electrolyte membrane. For the purpose of achieving the above-described purpose, the present invention has the configuration described below. Namely, a specific gas diffusion electrode base which has a carbon sheet and a microporous layer, and wherein the carbon sheet is porous and the DBP oil absorption of a carbon powder contained in the microporous layer is 70-155 ml/100 g.

Abstract: The present invention addresses the problem of providing: a towpreg that has superior bobbin unspoolability and process pass-through properties, and is capable of yielding a fiber-reinforced composite having extremely high 0° tensile strength utilization; and a pressure vessel using such a towpreg. The means for solving this problem is a towpreg obtained by impregnating a reinforcing fiber tow with an epoxy resin composition containing [A]-[D], wherein: the epoxy resin composition contains 10-90 parts by mass of [A] and 10-50 parts by mass of [B] per 100 parts by mass of the epoxy resin component; the epoxy resin composition has a 25° C. viscosity (?25) of 1-40 Pa·s and a 40° C. viscosity (?40) of 0.2-5 Pa·s; and the cured epoxy resin composition has a glass transition temperature (Tg) of 95° C. or higher.

Abstract: Disclosed is a prepreg comprising an epoxy resin composition containing [A] an epoxy resin and [B] a curing agent, and a reinforcing fiber, wherein the epoxy resin composition satisfies: (a) [A1] an epoxy resin represented by the general formula (I) is contained as the epoxy resin [A], and [A1?] an epoxy resin satisfying: n?2 among the component [A1]; wherein, R1, R2 and R3 each independently represent a hydrogen atom or a methyl group, and n represents an integer of 1 or more; (b) the entire epoxy resin has an average epoxy equivalent of 165 to 265 g/eq; (c) a water absorption coefficient at 85° C. and 95% RH for 2 hours is 3.0% by mass or less based on 100% by mass of the epoxy resin composition; (d) [B1] an aromatic urea as [B] a curing agent; and (e) the content of [B2] dicyandiamide is 0.5 part by mass or less based on 100 parts by mass of the entire epoxy resin.

Abstract: A gas diffusion electrode in which a microporous layer is provided on at least one surface of a conductive porous substrate, wherein the areas obtained by dividing the cross section perpendicular to the plane of the microporous layer into three equal parts in the thickness direction are a first area, a second area, and a third area, with respect to the conductive porous substrate side, the fluorine strength of the third area being 0.8 to 1.2 times the fluorine strength of the second area.

Abstract: A porous carbon sheet includes a carbon fiber and a binding material, wherein when in a measured surface depth distribution, a ratio of an area of a portion having a depth of 20 ?m or less in a measured area of one surface is a surface layer area ratio X, and a ratio of an area of a portion having a depth of 20 ?m or less in a measured area of another surface is a surface layer area ratio Y, the surface layer area ratio X is larger than the surface layer area ratio Y, and a difference between the surface layer area ratios is 3% or more and 12% or less.

Abstract: A gas diffusion electrode substrate that is used in a fuel cell and is constituted by an electrode substrate and microporous parts, in which a microporous part (A) is formed on one surface of the electrode substrate with a thickness in the range of 10 ?m or more and 60 ?m or less, and in the gas diffusion electrode substrate, the pore volume of pores with a pore size of 0.1 ?m or more and less than 10 ?m is within the range of 0.9 times or more and 5 times or less of the pore volume of pores with a pore size of 10 ?m or more and less than 100 ?m.

Abstract: A gas diffusion electrode substrate has an electrically conductive porous substrate and a microporous layer-1 on one side of the electrically conductive porous substrate. The microporous layer-1 includes a dense portion A and a dense portion B. The dense portion A is a region containing a fluorine resin and a carbonaceous powder having a primary particle size of 20 nm to 39 nm. The dense portion A has a thickness of 30% to 100% with respect to the thickness of the microporous layer-1 as 100% and a width of 10 ?m to 200 ?m. The dense portion B is a region containing a fluorine resin and a carbonaceous powder having a primary particle size of 40 nm to 70 nm.

Abstract: Provided is a fiber-reinforced composite material exhibiting high heat resistance and excellent appearance quality. is the composite material is based on an epoxy resin composition which contains constituents [A], [B], and [C] and satisfies conditions (i) and (ii): [A] a tri- or higher functional epoxy resin; [B] an aromatic amine; [C] an imidazole compound; 0.20?b/a?0.60; and??(i) 0.002?c/a?0.014;??(ii) wherein a (mol) denotes the number of epoxy groups in 100 g of the epoxy resin composition, b (mol) denotes the number of active hydrogens contained in the constituent [B], and c (mol) denotes the number of imidazole rings contained in the constituent [C]).

Abstract: Provided is a method for producing a fiber-reinforced composite material exhibiting high heat resistance and excellent appearance quality. It is a method for producing a fiber-reinforced composite material, which includes disposing a prepreg containing a reinforced fiber being impregnated with an epoxy resin composition in a mold, pressurizing and heating the prepreg at 0.2 to 2.5 MPa and 130° C. to 200° C. as primary curing, and then further heating the prepreg at 210° C. to 270° C. for 10 minutes or more as secondary curing.

Abstract: Disclosed herein are an epoxy resin composition for fiber-reinforced composite materials which has low viscosity, high Tg, high elastic modulus, and excellent fracture toughness and a fiber-reinforced composite material using such an epoxy resin composition which has excellent thermal properties, compressive strength, impact resistance, fatigue resistance, and open-hole tensile strength and which is suitable for producing structural parts of aircraft and the like. The epoxy resin composition comprises at least a given bifunctional epoxy resin as a component (A), a liquid aromatic diamine curing agent as a component (B), and core-shell polymer particles as a component (C), wherein the core-shell polymer particles as the component (C) contain epoxy groups in their shell and have a volume-average particle size of 50 to 300 nm.

Abstract: A gas diffusion electrode has a microporous layer on at least one surface of an electroconductive porous substrate. The microporous layer has a first microporous layer in contact with the electroconductive porous substrate, and a dense layer in contact with the first microporous layer. The thickness of the dense layer is at least 1 ?m. The average number density B of pores having a pore diameter of 0.15-1 ?m in the dense layer is at least 1.3A, where A is the average number density of pores having a pore diameter of 0.15-1 ?m in the microporous layer disposed on at least one surface of the electroconductive porous substrate.