| 摘要 |
PURPOSE:To improve the yield of molded products by preventing generation of carbonization, deterioration and a foreign matter, by a method wherein oxygen density in resin is made at equilibrium density or lower at an oxygen partial pressure specific value of atmosphere, heating and melting are performed under inert atmosphere and molded. CONSTITUTION:Oxygen, density in methacrylate resin of a molding material is made at equilibrium density or lower at oxygen partial pressure of 50mmHg of atmosphere, heating and melting are performed in an inert atmosphere and molded. With this construction, in a resin material, a quantity of dissolved oxygen in the resin is reduced and a molded product of little carbonizaiton, deterioration and foreign matter can be obtained. Furthermore, since the molded product wherein carbonization, deterioration and a foreign matter are little is obtained, at the time of molding of the heated and molten resin material by a molding machine, it is necessary to hold the molded product under the inert atmosphere. Since the resin material is held under the inert atmosphere, adsorption of oxygen to the resin material and entrapment of oxygen gas into the resin material in melting and kneading can be prevented. |
