BLOW-MOLDED OBJECT OF ULTRA-HIGH-MOLECULAR-WEIGHT POLYETHYLENE AND PRODUCTION THEREOF

摘要

PURPOSE:To produce a blow-molded object having excellent low-temperature characteristics and a high tensile strength at break by stretching at a specified temperature a parison produced from an ultra-high-molecular-weight polyethylene having a specified intrinsic viscosity. CONSTITUTION:A blow-molded ultra-high-molecular-weight polyethylene object is formed of an ultra-high-molecular-weight polyethylene having an intrinsic viscosity [eta] measured in a decalin solvent at 135 deg.C of at least 5dl/g. The blow-molded object has a tensile strength at break of at least 400kg/cm<2> in the machine direction, and at least 500kg/cm<2> in the transverse direction, together with a low-temperature embrittlement temperature of -50 deg.C or below. The blow-molded object is produced by a method wherein a parison comprising an ultra-high-molecular-weight polyethylene having an intrinsic viscosity [eta]measured in the decalin solvent at 135 deg.C of at least 5dl/g is stretched into a hollow shape at a temperature higher than the melting point of the polyethylene by 50 deg.C. The ultra-high-molecular-weight polyethylene to be used is a homopolymer or copolymer comprising a structural unit derived from ethylene.