MANUFACTURE OF POLYETHYLENE FILM

摘要

PURPOSE:To obtain a film whose elastic coefficient and strength are high, by a method wherein a high-elasticity and high-strength tape of ultra-high- molecular-weight polyethylene is turned into a fused film by softening or fusing an uncrystalline polymer and a secondary crystalline part contained into the tape. CONSTITUTION:An uncrystallized polymer part and secondary crystalline part act upon oriented polyethylene as a binder by softening or fusing them by performing heat treatment at a temperature ranging between the fusion temperature of a grown up crystal constituting the oriented polyethylene and that of the uncrystallized polymer part or the secondary crystalline part and the oriented polyethylene is made into a sheet. Then the film is obtained through an orienting method. Ultra-high-molecular-weight polyethylene to be applied to the titled method is an ethylene monopolymer whose intrinsic viscosity (eta) at a decalin solvent temperature of 135 deg.C is more than 5dl/g or two or more kinds of alpha-olefin copolymer having high crystallizability. A high-elasticity and high-strength tape of ultra-high-molecular-weight polyethylene whose tensile elastic coefficient (the first state) 30GPa ore more is desirable. The form of the tape shows a flattening rate of more than 5 and width is more than 3mm.