Patent ID: 9670328
Date: 2017-06-06
CPC Classifications: C08G,C08J

Claim:
1. A thermoset resin formulation for the manufacture of large and thick composite structures; said formulation consisting essentially of: (i) at least one liquid epoxy resin present in a weight proportion varying between 50 parts to 70 parts; (ii) at least one di-amine hardening agent present in a weight proportion varying between 21 phr to 29 phr and selected from the group consisting of isophorone diamine, 2,2′-dimethyl-4,4′-methylene bis(cyclohexyl amine), and diethyl toluene diamine; (iii) at least one low molecular weight epoxy diluent, other than the at least one liquid epoxy resin, present in a weight proportion varying in the range of 10 phr to 40 phr; and (iv) N,N-dimethylaminopropylamine, as an accelerator, present in a weight proportion varying between 0.5 phr to 3.0 phr; and wherein the thermoset resin formulation: has a viscosity suitable for vacuum assisted resin transfer molding; exhibits unchanged reactivity within a temperature range of 25° C. to 40° C.; and exhibits a negligible exotherm during a curing reaction at 40° C.