Copolymer of styrene and maleic anhydride comprising an epoxy resin composition and a co-cross linking agent

Abstract

A resin composition comprising a copolymer of styrene and maleic anhydride (SMA) as cross-linking agent, an epoxy resin, and a co-cross-linking agent, characterized in that the co-cross-linking agent is an optionally brominated bisphenol A (BPA), or an optionally brominated bisphenol A diglycidyl ether (BPADGE), or a mixture thereof, and that the composition is free from an allyl network forming compound. The resin composition may be applied to make laminates and printed wiring boards.

1 . A resin composition comprising a copolymer of styrene and maleic anhydride (SMA) as cross-linking agent, an epoxy resin, and a co-cross-linking agent, characterized in that the co-cross-linking agent is an optionally brominated bisphenol A (BPA), or an optionally brominated bisphenol A diglycidyl ether (BPADGE), or a mixture thereof, and that the composition is free from an allyl network forming compound.  
     
     
         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  wherein at least 10% by weight of TBBPA and at least 10% by weight of TBBPADGE are employed.  
     
     
         5 . The resin composition of any one of claims  1 - 4  wherein the epoxy resin is a derivative of bisphenol A, in particular FR4.  
     
     
         6 . The resin composition of any one of claims  1 - 5  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 any one of claims  1 - 6  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 any one of claims  1 - 7  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, preferably in the range of 75 to 125% by weight, and more preferably in the range of 90 to 110% 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 any one of the preceding claims, which optionally may be reinforced with fibres.  
     
     
         10 . A printed wiring board (PWB) made of the laminate of  claim 9.