| 摘要 |
PURPOSE:To prepare a heat-resistant polyethylene porous membrane with specific values of void volume, bubble point in ethanol, boiling xylene insolubles, breaking extension and shrinkage factor at the time of heat treatment to be endurable for the use under high temperature or heat treatment. CONSTITUTION:Polyethylene is cold oriented after being melt molded by using a nozzle for spinning, and then an almost hollow-yarn porous membrane is prepared by being heat oriented and relaxation heat set. Then, a solvent is volatilized after the porous membrane is immersed in the solution prepared by dissolving a radical generator such as 1,1-bis-(t-butylperoxy)-3,3,5-trimethyl cyclohexane or the like in the solvent, and the radical generated is retained on the porous membrane and heated in nitrogen. Thus, the porous membrane with 40-90% of void volume, 1.5kg/cm<3> or more of bubble point - breaking extension, 10% or less of shrinkage factor when heat-treated in pressurized water vapor at 121 deg.C for 30min and 30% or more of breaking extension after heat treatment is prepared. |
