Abstract: Polyolefin molding compositions and molded articles thereof exhibit exceptional mechanical strength, dimensional accuracy and heat deformation characteristics and are provided by melt-blending a polyolefin base resin, a liquid-crystal polyester resin, and a filler material. The liquid-crystal polyester is one which exhibits optical anisotropic characteristics in the melt-phase and preferably has a melt-viscosity of 20000 to 50 Poise as determined at a temperature of 310.degree. C. and a shear rate of 1200 sec.sup.-1. The liquid-crystal polyester resin forms a three-dimensional network structure throughout the polyolefin base resin and envelops substantially all of the filler material therewithin. As a result, the molded articles of the polyolefin compositions can be employed in end-use applications which require improved mechanical strength, dimensional accuracy and/or heat deformation characteristics.

Abstract: To provide a polyacetal resin composition having a minimal molding shrinkage and capable of forming a molding having good surface conditions and being resistant to friction and abrasion by solving a problem of delamination and problems posed in molding and processing when a polystyrene resin is incorporated into a polyacetal resin in order to improve its properties.A thermoplastic polystyrene resin B is incorporated into a polyacetal resin A by using a thermoplastic acrylic resin C as the third component and a combination of components A and B each having a melt flow value satisfying a specified condition as the components A and B, said components A, B and C being used in amounts of 55 to 95 parts by weight, 43 to 3 parts by weight and 20 to 2 parts by weight, respectively, for 100 parts by weight of the sum of A, B and C.