Electron Beam Cured Silicone Materials

Abstract

Methods of preparing silicone materials using electron beam curing are described. The materials are hot melt processed and cured in the absence of an effective amount of catalysts and initiators. Both functional and nonfunctionalized silicone materials may be used. Exemplary cured materials include silicone pressure sensitive adhesives, silicone foams, and non-tacky silicone films.

What is claimed is: 
     
         1 . A crosslinked silicone-based material made according a method comprising
 (a) hot melt processing a composition comprising a silicone material; and   (b) subjecting the composition to electron beam irradiation forming the crosslinked silicone-based material.   
     
     
         2 . The crosslinked silicone-based material of  claim 1 , wherein hot melt processing comprises extruding. 
     
     
         3 . The crosslinked silicone-based material of  claim 1 , wherein the silicone material is a nonfunctionalized silicone material. 
     
     
         4 . The crosslinked silicone-based material of  claim 1 , wherein the silicone material comprises a siloxane backbone and at least one functional group. 
     
     
         5 . The crosslinked silicone-based material of  claim 4 , wherein all functional groups are hydroxyl groups. 
     
     
         6 . The crosslinked silicone-based material of  claim 1 , wherein the crosslinked silicone-based material is a silicone pressure sensitive adhesive. 
     
     
         7 . The crosslinked silicone-based material of  claim 1 , wherein the silicone material is a polysiloxane. 
     
     
         8 . The crosslinked silicone-based material of  claim 7 , wherein the polysiloxane is a poly(dimethyl siloxane). 
     
     
         9 . The crosslinked silicone-based material of  claim 7 , wherein the polysiloxane is an aromatic siloxane. 
     
     
         10 . The crosslinked silicone-based material of  claim 1 , wherein the silicone material comprises a gum having a dynamic viscosity at 25° C. of greater than 1,000,000 mPa·sec. 
     
     
         11 . The crosslinked silicone-based material of  claim 1 , wherein the composition further comprises an MQ resin tackifier. 
     
     
         12 . The crosslinked silicone-based material of  claim 1 , wherein the composition further comprises at least one of glass bubbles and polymeric microspheres. 
     
     
         13 . The crosslinked silicone-based material of  claim 1 , wherein the silicone material comprises a silicone fluid having a dynamic viscosity at 25° C. of no greater than 600,000 mPa·sec. 
     
     
         14 . The crosslinked silicone-based material of  claim 1 , wherein the composition is substantially free of catalysts and initiators. 
     
     
         15 . An adhesive article comprising a substrate having a first major surface, and the silicone pressure sensitive adhesive according  claim 1  adhered to at least a portion of the first major surface of the substrate. 
     
     
         16 . The adhesive article of  claim 15 , wherein the substrate comprises a foam. 
     
     
         17 . The crosslinked silicone-based material of  claim 1 , wherein the crosslinked material is non-tacky.