Liquid resin compositions that can be used in the manufacture of composite materials are described. A method of making a fiber-reinforced polymeric composite material comprises wetting a fibrous material with a liquid prepolymer composition comprising at least one (meth)acrylic monomer, at least one base, and at least one peroxy ester; and polymerizing the liquid prepolymer composition to form a fiber-reinforced polymeric composite material.

A method of manufacturing a multilayer board includes forming conductor patterns on four or more insulating base material layers, forming a multilayer body by stacking the insulating base material layers in a state in which the conductor patterns face each other with prepreg layers therebetween, and heat-pressing the multilayer body. In a state before the step of heat-pressing, among the prepreg layers, a thickness of an outermost prepreg layer is larger than a thickness of a prepreg layer other than the outermost prepreg layer.

A method of manufacturing a multilayer board includes forming conductor patterns on four or more insulating base material layers, forming a multilayer body by stacking the insulating base material layers in a state in which the conductor patterns face each other with prepreg layers therebetween, and heat-pressing the multilayer body. In a state before the step of heat-pressing, among the prepreg layers, a thickness of an outermost prepreg layer is larger than a thickness of a prepreg layer other than the outermost prepreg layer.

An object of the present invention is to provide an epoxy resin composition that can be preferably used for prepreg and fiber reinforced composite material applications, has high Tg, and is excellent in elastic modulus and strength. The present invention is the epoxy resin composition including the following components [A] to [C] and satisfying the following conditions (1) to (2): [A]: epoxy resin [B]: polyamine curing agent, and [C]: a compound having a boiling point of 130° C. or more and a molecular weight m of 50 or more and 250 or less, the compound having no epoxy group in the molecule and having substantially no curing ability of an epoxy resin, (1): at least a part of the component [C] satisfies that the sum of the polar component and the hydrogen bond component in the Hansen solubility parameters is 10.0 or less, (2): the ratio C/E of the amount by mole, E, for epoxy groups of the component [A] to the amount by mole, C, of the component [C] satisfying the condition (1) is 0.01 or more and 0.20 or less.

Carbon fiber composites containing lignin carbon fibers are described. The lignin carbon fibers can be derived from organosolv lignin obtained from single source lignocellulosic feedstocks or combinations of such feedstocks or lignin obtained via other pulping or extraction methods. Also described are methods of preparing the carbon fiber composites.

Carbon fiber composites containing lignin carbon fibers are described. The lignin carbon fibers can be derived from organosolv lignin obtained from single source lignocellulosic feedstocks or combinations of such feedstocks or lignin obtained via other pulping or extraction methods. Also described are methods of preparing the carbon fiber composites.

Provided is a sheet molding compound having excellent thick portion-molding properties that can inhibit the occurrence of internal cracks even during the molding of a thick portion and enables a carbon fiber composite material molded article to be excellently released from a die. Also provided is a carbon fiber composite material molded article. The sheet molding compound of the present invention contains a fiber substrate (A) containing carbon fiber and a thermosetting resin composition (B), in which an average fiber length of the carbon fiber is 5 mm or more, and a volumetric molding shrinkage rate of the thermosetting resin composition (B) is 0.5% or more and 4.4% or less. Furthermore, the carbon fiber composite material molded article of the present invention has a thick portion having a thickness of 10 mm or more, in which the thick portion is formed of a cured material of the sheet molding compound of the present invention.

A resin composition contains a thermosetting resin (A) and an inorganic filler (B). The inorganic filler (B) includes: a first filler (B1); and a second filler (B2) of a nanometer scale having a smaller particle size than the first filler (B1). The first filler (B1) includes an anhydrous magnesium carbonate filler (b1) and an alumina filler (b2). The proportion of the first filler (B1) relative to a total solid content in the resin composition is equal to or greater than 50% by volume and equal to or less than 90% by volume. The proportion of the second filler (B2) relative to the total solid content in the resin composition is equal to or greater than 0.1% by volume and equal to or less than 2.0% by volume.

A resin composition contains a thermosetting resin (A) and an inorganic filler (B). The inorganic filler (B) includes: a first filler (B1); and a second filler (B2) of a nanometer scale having a smaller particle size than the first filler (B1). The first filler (B1) includes an anhydrous magnesium carbonate filler (b1) and an alumina filler (b2). The proportion of the first filler (B1) relative to a total solid content in the resin composition is equal to or greater than 50% by volume and equal to or less than 90% by volume. The proportion of the second filler (B2) relative to the total solid content in the resin composition is equal to or greater than 0.1% by volume and equal to or less than 2.0% by volume.

The purpose of the present invention is to provide: an epoxy resin composition which enables the achievement of a resin cured product that has high flame retardancy and excellent mechanical characteristics; and a prepreg and a fiber-reinforced composite material, each of which uses this epoxy resin composition. One embodiment of the epoxy resin composition according to the present invention, said epoxy resin composition having achieved the above-described purpose, contains the components (A) and (B) described below. (A): a bifunctional glycidyl amine type epoxy compound (B): an epoxy compound having a specific structure and/or an epoxy compound having another specific structure