Styrene-glycidyl acrylate copolymer foam

Claim 1

A FOAMED PRODUCT WHICH IS DIMENSIONALLY STABLE AT TEMPERATURES UP TO ABOUT 150*C., CONSISTING OF A STYRENEGLYCIDYL ACRYLATE COPOLYMER CONTAINING FROM 70-90 PERCENT BY WEIGHT STYRENE AND 10-30 PERCENT BY WEIGHT GLYCIDYL ACRYLATE, SAID COPOLYMER BEING CROSS-LINKED WITH ETHYLENEDIAMINE, SAID ETHYLENEDIAMINE BEING PRESENT BEFORE CURING IN AN AMOUNT EQUAL TO AT LEAST ONE ACTIVE HYDROGEN EQUIVALENT FOR EACH OXIRANE GROUP OF THE GLYCIDYL ACRYLATE, PREPARED BY INTIMATELY BLENDING PARTICLES OF A FOAMABLE COPOLYMER, HAVING THE AFORESAID CHEMICAL COMPOSITION AND HAVING INTEGRATED THEREWITH 5-30 PERCENT BY WEIGHT, BASED ON THE WEIGHT OF SAID COPOLYMER OF A VOLATILE ALIPHATIC HYDROCARBON BOILING IN THE RANGE OF 35100*C., WITH SAID ETHYLENEDIAMINE IN THE AMOUNT SPECIFIED AFORESAID, HEATING THE BLENDED MATERIAL TO VOLATILIZE SAID HYDROCARBON THEREFROM TO FORM AN INTEGRAL CELLULAR FOAM AT A TEMPERATURE BELOW THAT AT WHICH CONSIDERABLE CROSS-LINKING OCCURS DURING A PREDETERMINED TIME INTERVAL, AND CURING SAID FOAM BY HEATING AT A TEMPERATURE OF 80 TO 135*C. FOR AT LEAST 15 MINUTES.