The present invention relates to a fiber-reinforced plastic, including: a reinforcing fiber group containing reinforcing fibers; a thermosetting resin layer containing a first thermosetting resin; and a thermoplastic resin layer, in which the thermoplastic resin layer is provided as a surface layer of the fiber-reinforced plastic, an interface between the thermoplastic resin layer and the thermosetting resin layer is positioned inside the reinforcing fiber group, and the thermoplastic resin layer contains a dispersed phase of a second thermosetting resin.

The present invention relates to a resin composition containing: an epoxy resin; and an aromatic polysulfone resin containing an amino group-containing aromatic polysulfone having an amino group at at least one terminal of a main chain of a polymer chain, in which a number average molecular weight of the aromatic polysulfone resin is 10,000 or less.

A polymer composition comprising a star-branched copolymer having a plurality of arms is disclosed. Each polymer arm has a molecular weight Mp of from 1 kg/mol to 50 kg/mol and comprises polymerized units (i) derived from a first vinyl aromatic monomer comprising a radical-reactive group, wherein from greater than 10 mol % to 100 mol % of the units (i) are unhydrogenated; and optionally, polymerized units (ii) comprising hydrogenated and unhydrogenated forms of polymerized units derived from a high Tg monomer, and hydrogenated form of polymerized units (i) or hydrogenated form of polymerized styrene units; and optionally, polymerized units (iii) comprising (a) hydrogenated form of polymerized units derived from one or more acyclic conjugated dienes, and (b) polymerized units derived from one or more of a second vinyl aromatic monomer; wherein less than 10 wt. % of units (a) are unhydrogenated.

A polymer composition comprising a star-branched copolymer having a plurality of arms is disclosed. Each polymer arm has a molecular weight Mp of from 1 kg/mol to 50 kg/mol and comprises polymerized units (i) derived from a first vinyl aromatic monomer comprising a radical-reactive group, wherein from greater than 10 mol % to 100 mol % of the units (i) are unhydrogenated; and optionally, polymerized units (ii) comprising hydrogenated and unhydrogenated forms of polymerized units derived from a high Tg monomer, and hydrogenated form of polymerized units (i) or hydrogenated form of polymerized styrene units; and optionally, polymerized units (iii) comprising (a) hydrogenated form of polymerized units derived from one or more acyclic conjugated dienes, and (b) polymerized units derived from one or more of a second vinyl aromatic monomer; wherein less than 10 wt. % of units (a) are unhydrogenated.

The invention is targeted mainly at a process for the preparation of a semifinished product comprising a PAEK-based resin and reinforcing fibers, comprising the stages of: a. preparation of a dispersion comprising a PAEK-based resin in the pulverulent form dispersed in an aqueous phase comprising a surfactant; b. bringing the reinforcing fibers into contact with said aqueous dispersion; c. drying the fibers impregnated with dispersion; and d. heating the impregnated fibers to a temperature sufficient for the melting of the resin, so as to form a semifinished product,
characterized in that the surfactant is a thermally stable surfactant. It is furthermore targeted at the dispersion of use in said process. Finally, it is targeted at the semifinished products capable of being obtained and also at their use in the manufacture of composite materials.

Methods of making fiber-containing prepregs are described. The methods may include the steps of providing a plurality of fibers, and applying a reactive resin composition to the plurality of fibers to make a mixture of the plurality of fibers and the resin composition. The reactive resin composition may include at least one of monomers and oligomers capable of polymerizing into a polymerized resin matrix. The mixture may be heated to a polymerization temperature where the monomers, oligomers, or both polymerize to form a fiber-resin amalgam that includes the polymerized resin matrix. The fiber-resin amalgam may be formed into the fiber-containing prepreg. Also described are methods of forming a fiber-reinforced composite that includes the prepreg.

A resin composition for wiring board material contains a thermosetting resin and a thermally expandable microcapsule, in which the relative dielectric constant (10 GHz) of a cured product of the resin composition is more than 1.0 and 2.2 or less.

A resin composition for wiring board material contains a thermosetting resin and a thermally expandable microcapsule, in which the relative dielectric constant (10 GHz) of a cured product of the resin composition is more than 1.0 and 2.2 or less.

Provided is an epoxy resin composition containing an epoxy resin (A), a curing agent (B) and an imidazole adduct-type curing accelerator (C), in which the curing agent (B) contains a compound (B-1) represented by formula (B-1) [R.sup.1 represents a hydrogen atom, a halogen atom, a methoxy group or a hydrocarbon group having 1 to 12 carbon atoms] and a compound (B-2) represented by formula (B-2) [R.sup.2 represents a hydrogen atom, a halogen atom, a methyl group or a methoxy group] and the content of the compound (B-2) is 2 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the epoxy resin (A).

Provided is an epoxy resin composition containing an epoxy resin (A), a curing agent (B) and an imidazole adduct-type curing accelerator (C), in which the curing agent (B) contains a compound (B-1) represented by formula (B-1) [R.sup.1 represents a hydrogen atom, a halogen atom, a methoxy group or a hydrocarbon group having 1 to 12 carbon atoms] and a compound (B-2) represented by formula (B-2) [R.sup.2 represents a hydrogen atom, a halogen atom, a methyl group or a methoxy group] and the content of the compound (B-2) is 2 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the epoxy resin (A).