Copolymer of Styrene and Maleic Anhydride Comprising an Epoxy Resin Composition and Co-Cross-Linking Agent

Abstract

A composition useful as an impregnant for the making of laminates for printed wiring boards including an epoxy resin a first cross-linking agent of a strene-maleic anhydride copolymer and a second co-cross-linking agent.

1 . A resin composition comprising an admixture of a copolymer of styrene and maleic anhydride (SMA) as cross-linking agent, a curable composition of oxirane ring-containing compounds, and a co-cross-linking agent that is an optionally brominated bisphenol A (BPA) an optionally brominated bisphenol A diglycidyl ether (BPADGE) or a mixture of both an optionally brominated bisphenol A and an optionally brominated bisphenol A diglycidyl ether. 
     
     
         2 . The resin composition of  claim 1  wherein the co-cross-linking agent is tetrabromobisphenol A (TBBPA), tetrabromobisphenol A diglycidyl ether (TBBPADGE), or a mixture thereof. 
     
     
         3 . The resin composition of  claim 2  wherein the co-cross-linking agent is a mixture of tetrabromobisphenol A (TBBPA) and tetrabromobisphenol A diglycidyl ether (TBBPADGE). 
     
     
         4 . The resin composition of  claim 3  including at least 10% by weight of TBBPA and at least 10% by weight of TBBPADGE are employed. 
     
     
         5 . The resin composition of  claim 1  wherein the epoxy resin is a derivative of bisphenol A. 
     
     
         6 . The resin composition of  claim 1  wherein the SMA has a molecular weight of about 1400 to about 50,000, and an anhydride content of more than 15% by weight. 
     
     
         7 . The resin composition according to  claim 1  wherein the SMA is selected from one SMA or a mixture of SMAs having a styrene:maleic anhydride ratio of 1:1, 2:1, 3:1, or 4:1, and a molecular weight from about 1400 to about 2000. 
     
     
         8 . The resin composition according to  claim 1  wherein a copolymer is used such as to give an equivalency ratio of anhydride and aromatic hydroxy groups:epoxy groups in the range of 50 to 150% by weight. 
     
     
         9 . A laminate comprising a synthetic layer and a metal layer, characterized in that the synthetic layer is composed of the resin composition of  claim 1 . 
     
     
         10 . A printed wiring board (PWB) comprising the laminate of  claim 9 . 
     
     
         11 . The laminate of  claim 9  wherein the synthetic layer is reinforced with fibers.