Heat insulating material and method for producing same

摘要

The heat insulator of this invention comprises a thermoformed open cell rigid polyurethane foam core enclosed in a gas barrier material and evacuated. The method of this invention comprises heating an open cell rigid polyurethane foam at a temperature not lower than the temperature at which its storage modulus of elasticity begins to decrease and enclosing the thus-thermoformed polyurethane foam in a gas barrier material and evacuating the interior of the enclosure. The heat insulator of the invention is highly heat-insulating and can be snugly applied to irregular surfaces.