The graft copolymer and its manufacturing method, a resin composition and a molded article

The present invention discloses a method for producing a graft copolymer, obtained by the method of the graft copolymer, blended with the graft copolymer has excellent impact resistance in a resin, sufficient heat resistance and resistance incombustible resin composition, and the resin composition molded product obtained by molding; the method for producing the graft copolymer in the toluene-insoluble matter is more than 20% by mass of a polyorganosiloxane-based rubber (a) in the presence of a vinyl monomer comprising a polyfunctional vinyl monomer (b1) is a method for producing a graft copolymer polymerized (B); with respect to the polyorganosiloxane-based rubber (a) and a vinyl monomer (B) having a total of 100% by mass, the mass ratio of the polyfunctional vinyl monomer (b1) from 11 to 19% by mass.