Patent ID: 7988907
Filing Date: 2011-08-02
Classification: B29C,B29K,C08L,C09K,Y10T

Abstract:
1. A method for manufacturing a pressure-resistant container liner by a blow molding, comprising: a resin composition melting step of heating a blow molding liquid crystal resin composition within a temperature range from a melting point to the melting point +40° C. to melt the resin composition, the resin composition being produced by blending, melting and kneading (A) 100 weight parts of liquid crystal polyester and/or liquid crystal polyester amide, (B) 10 to 25 weight parts of styrene series copolymer comprising 40 to 97% by weight of one or more kinds of styrenes, 60 to 3% by weight of glycidylester of an α, β-unsaturated acid expressed by a following general formula (1), and 0 to 50% by weight of another vinyl monomer, the styrene series copolymer having an epoxy equivalent of 1700 to 3000 g/eq and a weight average molecular weight of 30000 or more, where —R′ denotes hydrogen or an alkyl group, and (C) 0 to 100 weight parts of one or more kinds of fibrous, particulate, and plate-like fillers, the resin composition having a melt viscosity of 60 to 4000 Pa·s at a temperature higher than the melting point by 20° C. at a shear rate of 1000/sec and a melt tension of 20 mN or more at a take-over speed of 15 m/min; a parison forming step of extruding and forming a cylindrical parison with an extrusion speed equal to or higher than 0.3 kg/minute and lower than 5 kg/minute by using the specific resin composition melt in the resin composition melting step; a mold closing step of placing the parison formed in the parison forming step between a pair of molds forming a cylindrical cavity and of closing the molds; and a forming step of blowing gas into the parison in the molds closed in the mold closing step to form a liner, wherein: the resin composition in which an increase rate of a melt tension at a twice take-over speed (30 m/minute) to the melt tension at the take-over speed of 15 m/minute is 1.05 or more, is used.