MANUFACTURE OF PLASTIC LENS AND ADHESIVE TAPE FOR MANUFACTURING SAME PLASTIC LENS

摘要

PURPOSE:To obtain a good plastic lens free from optical distortion by a method wherein an adhesive tape obtained by laminating an adhesive agent to a specific plastic film base material is stuck close to the sides of two molds and a polymerizable substance is cast into the mold formed by surrounding with the two molds and adhesive tape for polymerization. CONSTITUTION:An adhesive tape obtained by laminating an adhesive agent to a plastic film base material whose permeability factor to oxygen and that to vapor do not exceed respectively 15cc/m<2>.24hr.0.1mm and 10g/m<2>.24hr.0.1mm is stuck close to the sides of two molds positioned at a fixed interval. A polymerizable substance is polymerized by casting the same into a mold formed by surrounding with the two molds and adhesive tape and the plastic lens is manufactured. Polyvinylidene fluoride or its polymer or an ethylene-vinyl alcohol copolymer is available as a plastic film satisfying important matters of this oxygen and permeability to the vapor. Generally a range of 10-100mum is good for a suitable thickness of the plastic film base material.