Patent ID: 6572794
Filing Date: 2003-06-03
Classification: B29C,B29D,B29K,B29L,C08F,C09K

Abstract:
A method of manufacturing a photochromic molded article comprising the steps of:(a) filling a mold with a photopolymerizable monomer composition containing: at least one photopolymerizable monomer; at least one photoinitiator; and at least one photochromic compound capable of coloring upon ultraviolet irradiation; (b) photopolymerizing said photopolymerizable composition under irradiation with a light comprising a UV portion and optionally a UV-visible portion; wherein before the beginning of the photopolymerization step, said photopolymerizable composition is subjected to a pre-heating step in which the temperature of said photopolymerizable composition is increased to a temperature which at least reduces or prevents coloration of said at least one photochromic compound during the photopolymerization step.