FOAMED SHEET-LIKE POLYCARBONATE WITH IMPROVED SURFACE PROPERTIES AND PREPARATION THEREOF

摘要

PURPOSE:To improve heat-insulating properties and surface characteristics by forcing a specified foaming agent into a polycarbonate resin heat-melted with an extruder and extrusion-molding the mixture. CONSTITUTION:After a polycarbonate resin wherein a plasticizer, a lubricant, a nucleating agent (e.g. talc) are incorporated is fed in an extruder and heat- melted, a foaming agent with a solubility parameter of 6.5 or larger (e.g. methylene chloride) is forced thereinto so as to obtain a ratio of 0.11 to 1.1mol/kg resin and the mixture is extruded into a sheet to obtain a foamed polycarbonate sheet with a foaming ratio 2 to 20, a mean cell diameter of 0.2mm or larger and a thickness of 5mm or less.