| abstract |
Describes polymerizable organic resin compositions of from about 70 to 90 weight percent of a polyol(allyl carbonate), e.g., diethylene glycol bis(allyl carbonate), and from about 30 to 70 weight percent of aliphatic polyurethane having terminal allylic unsaturation. The polymerizable compositions have initiated pot life times of at least about 24 hours at 25° C. and castings that have low yellowness (b*) values. Polymerizates prepared from such compositions may be used to prepare photochromic articles, e.g., lenses, by incorporating a photochromic substance, e.g., by thermal transfer, into the polymerizate. |