The present invention relates to a process for preparing a resin composition comprising benzoxazine, a prepreg and a laminate prepared therefrom. Said resin composition comprising benzoxazine is prepared by adding an acidic filler into the resin composition comprising benzoxazine, wherein said resin composition comprising benzoxazine comprises a benzoxazine resin, an epoxy resin A1 having an epoxy equivalent of 150-450, and an epoxy resin A2 having an epoxy equivalent of 451-1000. By adding an acidic filler into the resin composition, the present invention greatly promotes the polymerization of benzoxazine and epoxy resins, and decreases the curing temperature needed for the polymerization of benzoxazine and epoxy resins. The laminates prepared from the resin composition added with an acidic filler have a high anti-stripping stability, a high glass transition temperature, a low water absorption, a high heat resistance, a high bending strength and a better processability, and can achieve a low coefficient of thermal expansion.

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.

A molding compound is made by heat-softening, fusing and compressing strips of unidirectionally aligned filaments embedded in a thermosetting resin. The thermosetting resin is non-tacky at room temperature, which allows for easy handling, elimination of cold storage and the use of robotic manufacturing methods. Composites made by molding the molding compound have excellent, highly isotropic tensile properties.

Provided are a method for producing an FRP precursor and a device for producing an FRP precursor, wherein the method and the device have a good productivity, and under a normal pressure, enable filling of a resin into a bulk gap of an aggregate as well as prevent the resin from spouting out from an edge portion thereof. The method for producing the FRP precursor is to produce the FRP precursor by melt-adhering each of a pair of thermosetting resin films 54 to each of both surfaces 40a and 40b of an aggregate 40 that is in a form of a sheet, the method comprising: an aggregate's surface heating process to heat aggregate's both surfaces, i.e., the both aggregate's surfaces 40a and 40b of the aggregate 40, and a film press-adhering process to obtain the FRP precursor wherein under a normal pressure, one aggregate-side film surface 54a of the pair of the films 54 is press-adhered to one surface of the heated both aggregate's surfaces, and another aggregate-side film surface 54a of the pair of the films 54 is press-adhered to another surface of the heated both aggregate's surfaces.

The present invention relates to a halogen-free resin composition and a prepreg and a laminated board prepared therefrom. The halogen-free resin composition contains the following components in parts by weight: 50-100 parts of an epoxy resin; 20-70 parts of benzoxazine; 5-40 parts of a polyphenyl ether; 5-40 parts of allyl benzene-maleic anhydride; 10-60 parts of a halogen-free flame retardant; 0.2-5 parts of a curing accelerator, and 20-100 parts of a filler. The prepreg and laminated board prepared from the halogen-free resin composition have comprehensive performances such as a low dielectric constant, a low dielectric loss, an excellent flame retardance, heat resistance, cohesiveness and moisture resistance, etc., and are suitable for use in a halogen-free high multilayer circuit board.

Provided are a thermosetting resin composition whose cured product exhibits a low dielectric constant and a low loss tangent as well as excellent flame retardancy, heat resistance, and thermal decomposition resistance, a cured product obtained from the thermosetting resin composition, and an active ester resin for use in the thermosetting resin composition. Specifically, the thermosetting resin composition contains, as essential components, an epoxy resin and an active ester resin having a resin structure that has a structural segment represented by formula (I) below and monovalent aryloxy groups at both terminals:

##STR00001##

An epoxy resin exhibits a small change in volume after thermal history, is excellent in low thermal expansion and low moisture absorption, and has high heat resistance, in terms of a cured product obtained therefrom; a curable resin composition; a cured product which has all the above properties; a semiconductor encapsulating material; a semiconductor device; a prepreg; a circuit board; a buildup film; a buildup substrate; a fiber-reinforced composite material; and a molded article. The present invention is characterized by an epoxy resin, characterized by including as essential components, a cresol-naphthol co-condensed novolac type epoxy resin (A), a naphthol glycidyl ether compound (B), and one or more xanthene compounds (C) selected from the group of compounds represented by the following structural formulae (1) to (3), wherein the content of the xanthene compound(s) (C) is from 0.1% to 5.5% in terms of area ratio in a GPC measurement. ##STR00001##

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 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.

An epoxy resin composition having a first epoxy resin component containing an oxazolidone; a second epoxy resin component; a latent hardener comprising dicyandiamide particles having a particle distribution in which at least 35% of the dicyandiamide particles have a particle size of less than 2 microns; and an epoxy soluble latent catalyst is provided. It has been found that the combination of the epoxy components, a latent hardener having dicyandiamide particles in which at least 35% of the dicyandiamide particles have a particle size of less than 2 microns, and an epoxy soluble latent catalyst provides an epoxy resin composition that provides a more homogeneous infusion of the resin into a fibrous material for forming a prepreg. As a result, faster cure of the epoxy resin composition is obtained, which in turn, reduces the mold cycle time for preparing molded articles and parts.

A prepreg tape in which reinforcing fiber bundles are impregnated with a thermosetting resin composition, wherein the prepreg tape has a tack value measured at 23 C. at a plunger push pressure of 90 kPa of 5-40 kPa, a tack value measured at 45 C. and a plunger push pressure of 150 kPa of 35-100 kPa, and a drape value at 23 C. of 10-40, and includes unidirectional fibers arranged along the direction of length of the prepreg tape.