| 摘要 |
PROBLEM TO BE SOLVED: To provide an ultra-high molecular weight polyethylene foam having a skin layer with added functions such as an excellent appearance, lightness, heat insulating property, sound absorbency, reduced dielectric constant, shock-absorbing property, flexibility or the like without greatly reducing excellent wear resistance, self-lubricating property, impact resistance, low temperature resistance, chemical resistance or the like originally belonging to the ultra-high molecular weight polyethylene, and to provide a method for stable production of the foam. SOLUTION: The invention relates to the foam obtained by foaming the ultra-high molecular weight polyethylene having 30×10<SP>4</SP>-1,000×10<SP>4</SP>of viscosity average molecular weight wherein the foam has 0.02-0.7 g/cm<SP>3</SP>of density. The foam is obtained by adding carbon dioxide to the ultra-high molecular weight polyethylene in molten state in an extruder, arranging the residence time and pressure of the resin in the die section at a specific value, and extruding and foaming the resin by arranging the surface temperature of the resin immediately after extrusion from the die section and the temperature in the resin center at the predetermined temperature. COPYRIGHT: (C)2005,JPO&NCIPI |
