An object of the present invention is to provide a molding material which can suppress film lifting, gives good peelability of release paper, and can produce therefrom a fiber-reinforced composite article with good demoldability from a metal mold, and a fiber-reinforced composite article. The molding material of the present invention comprises an epoxy resin composition comprising a component (A): an epoxy resin, a component (B): an epoxy resin curing agent, and a component (C): an unsaturated fatty acid ester compound having a melting point or pour point of 25 C. or lower; and a reinforcing fiber substrate, wherein the reinforcing fiber substrate is impregnated with the epoxy resin composition.

Provided are an epoxy resin composition, a prepreg, a resin sheet, and a carbon fiber-reinforced composite material, which have high heat resistance, a high elastic modulus, low water absorption, and excellent flame resistance. This epoxy resin is a para-cresol novolac epoxy resin represented by General formula (1), in which a content ratio of components represented by n=1 as measured by gel permeation chromatography is less than 10% by area, and a content ratio of components represented by n=2 as measured by gel permeation chromatography is at least 1% by area and less than 40% by area.

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(In the formula, plural R's each independently represent a C1-6 alkyl group, n represents a real number of 1 to 10, and G represents a substituted or unsubstituted glycidyl group.)

Composite honeycomb that may be contoured to form composite honeycomb structures, which have tight radii of curvatures and/or compound curvatures, and which are suitable for use in high temperature environments. The method for making the composite honeycomb involves using high temperature prepreg to make a flexible composite honeycomb that is formed into a composite honeycomb precursor. A high temperature coating resin is applied to the composite honeycomb precursor to form the high temperature composite honeycomb.

The present invention provides a heat-curable resin composition, which comprises (1) a heat-curable resin mixture comprising a heat-curable resin (a) and thickener particles (b) and exhibiting a viscosity (150 C.) after having been held at a temperature of 150 C. for 30 seconds that is a viscosity (S), and (2) a curing agent, and is characterized in that the heat-curable resin composition exhibits a lowest viscosity (R) at 80-120 C., the lowest viscosity (R) is 0.1-10 Pa.Math.s, and the viscosity (S) and lowest viscosity (R) satisfy the relationship of formula (1):
5<S/R<200formula (1).

Provided is a heat-curable resin composition exhibiting a superior handling property and workability in the form of a film, having a high adhesion to a base material, and capable of yielding a cured product with a low elasticity. The heat-curable resin composition contains: (A) 90 to 10 parts by mass of a silicone-modified epoxy resin; (B) 10 to 90 parts by mass of a maleimide compound having a weight-average molecular weight (Mw) of 2,500 to 50,000; and (C) a curing catalyst,
provided that a total of the components (A) and (B) is 100 parts by mass.

Provided is a resin composition for forming a resin layer of a laminate by coating, the resin composition having a thixotropic index at 25 C. of from 3 to 10, and the laminate includes a pair of members and the resin layer arranged between the pair of members.

The present invention provides thermosetting resin pre-impregnated or infused fiber materials or prepregs comprising a fiber material of a heat resistant fiber, such as a continuous fiber material or a discontinuous chopped fiber mat, infused with a thermosetting resin mixture comprising (i) at least one liquid epoxy resin; (ii) at least one epoxy novolac resin, (iii) dicyandiamide and (iv) and an adduct of a cycloaliphatic amine and a liquid epoxy resin, wherein the dicyandiamide is dissolved in the adduct of a cycloaliphatic amine and a liquid epoxy resin. The prepreg or fiber material has a shelf life of at least 30 days at ambient temperature and pressure before its Initial Tg (DSC) rises above 40 C.

A semipreg that can be cured/molded to form aerospace composite parts including rocket booster casings. The semipreg includes a fibrous layer and a resin layer located on one side of the fibrous layer. The resin layer includes an epoxy component that is a combination of a hydrocarbon epoxy novolac resin and a trifunctional epoxy resin and optionally a tetrafunctional epoxy resin. The resin matrix includes polyethersulfone as a toughening agent and a thermoplastic particle component.

Peel ply for surface preparation and a method of surface preparation prior to adhesive bonding. A resin-rich peel ply is applied onto a curable, resin-based composite substrate, followed by co-curing. After co-curing, the composite substrate is fully cured but the matrix resin in the peel ply remains partially cured. When the peel ply is removed, a roughened, bondable surface with chemically-active functional groups is revealed. The composite substrate with the chemically-active, bondable surface may be bonded to another composite substrate to form a covalently-bonded structure.

Pre-impregnated composite material (prepreg) that can be cured/molded to form aerospace composite parts. The prepreg includes carbon reinforcing fibers and an uncured resin matrix. The resin matrix includes an epoxy component, polyethersulfone as a toughening agent, and a curing agent. The resin matrix is also composed of a thermoplastic particle component that includes hybrid polyamide particles wherein each hybrid particle contains a mixture of amorphous and semi-crystalline polyamide.