PRESSING PLATE-SHAPED BODY

摘要

A method of producing a plate-shaped body, particularly a video disc in which circumferential warp in the thicknesswise direction, thickness fluctuation and deflection of the signal track are minimized comprising The steps of pressing by a mold a thermoplastic resin which has been heated to a temperature above the softening point thereof, and cooling the thermoplastic resin to solidify the same. During the cooling, the pressure of the mold is decreased to a low level when the thermoplastic resin has been cooled down to a temperature around the softening point. The thermoplastic resin is allowed to be solidified without any substantial and local residual stress to ensure minimal circumferential warp, thickness fluctuation and deflection signal track.