Many attempts have been made to devise laminating resins having low volatile emissions and still meet the physical specifications and other desirable properties of the end products, while remaining relatively easy to use. In Lee U.S. Pat. No. 4,465,806, for example, a more or less conventional unsaturated polyester resin is combined with, instead of the usual styrene, a reaction product of a polyepoxy compound and acrylic or methacrylic acid which may be the diacrylate of a polyglycidyl ether of bisphenol-A.
Cycloaliphatic epoxides are well known. They have been reacted with various other materials and used in various environments. See the bulletin on cycloaliphatic epoxide systems published by Union Carbide Corporation. The reaction product of such materials with acrylic acid or methacrylic acid are not well known, and although aliphatic epoxys are enumerated as potential ingredients in some vinyl ester resin patents, they are not demonstrated in any nor are they mentioned as a possible use for cycloaliphatic epoxy resins in any of Union Carbide's (the manufacturer) literature. Further, when we formed these vinyl ester resins we found it necessary to depart radically from the accepted ratio of one monounsaturated acid per unreacted epoxy group to a preferred ratio of one monounsaturated acid per 1.6 epoxy groups. This indicated a different chemistry from that found in forming BPA epoxy vinyl ester resins.
Ethoxylated, difunctional, bisphenol-A has been used in the past as an ingredient in various types of resins, generally resins which include a significant diisocyanate component, as in Ford, Jr. et al U.S. Pat. No. 3,876,726.
However, we are not aware of any combinations in the prior art of the types of laminating resins we employ in our invention, namely combinations of alkoxylated difunctional bisphenol-A and vinyl ester resins based on cycloaliphatic epoxides.