公开(公告)号：JPS5825929A

公开(公告)日：1983-02-16

申请号：JP12474981

申请日：1981-08-11

Applicant: TORAY INDUSTRIES

Inventor： TSUNASHIMA KENJI ,  YOSHII TOSHIYA ,  FUKUYAMA TAKEO

IPC: B32B27/32 ,  B29C49/00 ,  B29C55/00 ,  B29C55/12 ,  B32B37/00

Abstract: PURPOSE:To prepare a laminated film of even thickness and excellent transparency by such an arrangement wherein common extrusion is carried out so that a film of crystalline polyolefine of high melting point is laminated on both sides of a film of crystalline polyolefine of low molecular weight, and then bi-axial stretching and heat treatment are carried out. CONSTITUTION:At least one of crystalline low molecular weight polyolefine A of which extreme viscosity is 0.5-1.5 and crystalline polyolefine B of higher melt ing point is added with a crystal forming nuclear agent of 0.001-0.5wt% and they are simultaneously extruded so that films of polyolefine B are laminated on both sides of polyolefine A. Next, this laminated films is bi-axially stretched and then heat treated at a temperature higher than the melting point of polyolefine A and lower than that of polyolefine B. By this manner, uneven thickness at the time of two-shaft elongation is eliminated and a laminated film of polyolefine of good transparency can be manufactured.

公开(公告)号：JPS5818260A

公开(公告)日：1983-02-02

申请号：JP11676281

申请日：1981-07-25

Applicant: TORAY INDUSTRIES

Inventor： TSUNASHIMA KENJI ,  YOSHII TOSHIYA ,  FUKUYAMA TAKEO

IPC: B32B7/10 ,  B32B27/32