| abstract |
PURPOSE: To obtain high surface accuracy and excellent optical properties by previously adding an internal release agent to a monomer mixture. n CONSTITUTION: The internal release agent is added to the mixture composed of arom. polyisocyanate contg. sulfur atoms and arom. polyol and/or active hydrogen compd. which is polyol and the mixture is subjected to cast polymerization. The internal release agent to be used is exemplified by, for example, fluorine nonionic surfactant, silicon nonionic surfactant, etc., and is adequately selected according to the combination of the monomers, polymn. conditions, economy, and ease of handling. The plastic lens obtd. in such a manner has the high surface accuracy and the excellent optical properties, is light in weight and is highly resistant to impact. The lens is thus adequate as optical element stocks for spectacle lenses, camera lenses etc. n COPYRIGHT: (C)1990,JPO&Japio |