PURPOSE: To obtain the titled molded article having excellent dimensional stability and appearance, by mixing liquid A consisting of caprolactam and a catalyst, liquid B consisting of caprolactam, a rubber compound containing a branched polyhydric alcohol and an activation agent and liquid C consisting of a filler, etc., and injection-molding the mixture.

CONSTITUTION: The objective molded article can be produced by pouring and mixing (A) a liquid A of a nylon RIM material composed of caprolactam and an alkali main catalyst, (B) a liquid B of a nylon RIM material composed of caprolactam, a rubbery compound composed mainly of a branched olefinic polyhydric alcohol having a molecular weight of 1,000W10,000 and an activation agent of formula (Ar is bivalent aromatic residue; X is halogen; m is 1W6; Y and Y' are acyl such as CO, SO, etc.; n and n' are 3W11) and (C) a liquid C composed of a fibrous or flaky filler having an average ratio of 5W15 and a spherical filler having an average aspect ratio of 1W3 from respective storage tanks 2W4 in a mixing head 11 and injecting the mixture into a hybrid mold 1 composed of a metallic skin layer and a resin back-up under pressure.