Quinone → Carbamic acid, ethyl ester

Participants

Reaction Conditions

Reaction Steps

A U.V. curable urethane composition is prepared by heating 104.4 grams (0.6 moles) of tolylene diisocyanate to 70° C. and, while maintaining this temperature adding dropwise over 2 hours a homogeneous solution, also heated to 70° C., consisting of 26.8 grams of trimethylolpropane, 79.0 grams of methyl methacrylate and 0.02 grams p-benzoquinone. At the end of the reaction period, the product is maintained at 70° C. for an additional 6 hours. There is, thereafter, added dropwise 57.2 grams of 2-hydroxyethyl methacrylate over a period of one-half hour, after which the reaction is continued for an additional 10 hours, followed by the addition of 43 grams methyl methacrylate, to obtain a methyl methacrylate solution of a light yellow, transparent photopolymerizable prepolymer containing approximately 1.8% by weight of isocyanate groups.

Provenance & Evidence