MOLD FOR INJECTION MOLDING AND INJECTION MOLDING METHOD

PROBLEM TO BE SOLVED: To obtain a mold for injection molding and an injection molding method improving a transferability, at the same time, effectively preventing a defect such as a crack or the like from occurring on the molding, and also not disturbing achievement of high-cycle operation. SOLUTION: The mold for injection molding to produce an optical element by injecting an amorphous polyolefinic resin into a space for resin molding in the mold and the injection molding method are provided. The surface temperature of the resin molding space when the amorphous polyolefinic resin is filled into the the resin molding space can be kept at a temperature higher than a glass transition temperature of the amorphous polyolefinic resin by arranging a heat insulating material around the resin molding space. The surface temperature of the resin filled in the resin molding space changes as shown in a curve b, the temperature at the time of completing filling of the resin is higher than the glass transition temperature as shown at a point A, a temperature difference B between the surface part of the resin (a skin layer) and a core part of the resin is small, therefore a residual stress at the dwelling process or a cooling process can be reduced. COPYRIGHT: (C)2006,JPO&NCIPI