Copolymers of hydroxyalkyl acrylates and methacrylates and alkyl acrylates and methacrylates reacted with diisocyanates

Claim 1

A HARD THOUGH THERMOSET RESIN FORMED BY REACTING TOGETHER AT A TEMPERATURE OF FROM ABOUT 50*C. TO ABOUT 150*C. AT LEAST ONE COMPOUND FROM EACH OF THE THREE GROUPS AS FLLOWS: (A) A LOW MOLECULAR WEIGHT COPOLYMER OF FROM ABOUT 20 MOLE PERCENT TO ABOUT 40 MOLE PERCENT OF A COMPOUND SELECTED FROM THE CLASS CONSISTING OF HYDROXYALKYL ACRYLATES AND METHACRYLATES AND ABOUT 60 MOLE PERCENT TO ABOTU 80 MOLE PERCENT OF A COMPOUND SELECTED FROM THE CLASS CONSISTING OF ALKYL ACRYLATES AND METHACRYLATES, HAVING AN AVERAGE NUMBER OF HYDROXYL GROUPS PER POLYMER CHAIN OF AT LEAST 2 BUT NOT MORE THAN 3.5, (B) A COMPOUND SELECTED FROM THE CLASS CONSISTING OF DIHYDRIC AND TRIHYDRIC ALCOHOLS, AND (C) AN ORGANIC DIISOCYANATE, IN THE RATION PER 100 PARTS OF (A), OF ABOUT 15 TO 20 PARTS OF (B) AND ABOUT 40 TO 90 PARTS OF (C).