Abstract: To provide a flame-retardant resin composition that has superior adhesion subsequent to curing and molding when used as a printed wiring board adhesive and that provides superior printed wiring board electrical characteristics; and a flexible printed wiring board metal-clad laminate, a coverlay, a flexible printed wiring board adhesive sheet, and a flexible printed wiring board employing this resin composition. (SOLUTION) The flame-retardant resin composition comprises a thermosetting resin, a hardener, and a phosphorus-containing polymer.

Abstract: The present invention provides a polyamideimide resin for flexible printed circuit boards that prior to curing exhibits an excellent solubility, processability, and handling characteristics, and that after curing exhibits flame retardancy, solder heat resistance, circuit embeddability, and flexibility and further has a high glass-transition temperature (Tg) and is able to maintain a high adhesive strength. The present invention provides a polyamideimide resin for flexible printed circuit boards, which is obtained by the polymerization reaction of an acid component comprising at least a monoanhydride and an aromatic dicarboxylic acid with a diisocyanate compound or diamine compound in an approximately equimolar amount with respect to the total molar amount of the acid component, wherein the molar amount of the monoanhydride is 0.4 to 0.8 taking the total molar amount of the acid component as 1.

Abstract: The present invention provides a polyamideimide resin for flexible printed circuit boards that prior to curing exhibits an excellent solubility, processability, and handling characteristics, and that after curing exhibits flame retardancy, solder heat resistance, circuit embeddability, and flexibility and further has a high glass-transition temperature and is able to maintain a high adhesive strength. The present invention provides a polyamideimide resin for flexible printed circuit boards, which is obtained by the polymerization reaction of an acid component comprising at least a monoanhydride and an aromatic dicarboxylic acid with a diisocyanate compound or diamine compound in an approximately equimolar amount with respect to the total molar amount of the acid component, wherein the molar amount of the monoanhydride is 0.4 to 0.8 taking the total molar amount of the acid component as 1.

Abstract: The present invention provides a polyamideimide resin for flexible printed circuit boards that prior to curing exhibits an excellent solubility, processability, and handling characteristics, and that after curing exhibits flame retardancy, solder heat resistance, circuit embeddability, and flexibility and further has a high glass-transition temperature (Tg) and is able to maintain a high adhesive strength. The present invention provides a polyamideimide resin for flexible printed circuit boards, which is obtained by the polymerization reaction of an acid component comprising at least a monoanhydride and an aromatic dicarboxylic acid with a diisocyanate compound or diamine compound in an approximately equimolar amount with respect to the total molar amount of the acid component, wherein the molar amount of the monoanhydride is 0.4 to 0.8 taking the total molar amount of the acid component as 1.