Reformable epoxy resin for composites

Abstract

The present invention contemplates a method for forming a composite structure including a plurality of rigid layers and one or more reformable epoxy resin layers. The resulting composite is molded to form a non-planar composite structure.

What is claimed is: 
     
         1 ) A method comprising:
 i. forming a substantially planar composite structure having at least two layers;   ii. applying a reformable epoxy resin material onto one or more of the at least two layers;   iii. optionally cutting the composite structure to a desired shape;   iv. heating the composite structure in a mold to form a non-planar composite structure.   
     
     
         2 ) The method according to  claim 1 , wherein the reformable epoxy resin epoxy material falls below its glass transition temperature upon exposure to ambient temperature in less than 5 minutes. 
     
     
         3 ) The method according to  claim 1 , wherein after the reformable epoxy resin material falls below its glass transition temperature, it can be heated multiple times above its glass transition temperature for molding into the non-planar composite structure. 
     
     
         4 ) The method according to  claim 3 , wherein the reformable epoxy resin material falls below its glass transition temperature upon exposure to ambient temperature. 
     
     
         5 ) The method according to  claim 2 , wherein the composite structure is a furniture panel. 
     
     
         6 ) The method according to  claim 2 , wherein the composite structure is an automotive or aerospace panel. 
     
     
         7 ) The method according to  claim 1 , wherein the reformable epoxy resin material falls below its glass transition temperature prior to forming the non-planar composite structure. 
     
     
         8 ) The method according to  claim 1 , wherein at least one of the at least two layers is a wood material. 
     
     
         9 ) The method according to  claim 3 , wherein at least one of the at least two layers is a polymeric material. 
     
     
         10 ) The method according to  claim 2 , wherein the reformable epoxy resin material is stored at room temperature prior to use. 
     
     
         11 ) The method according to  claim 1 , wherein the shelf life of the reformable epoxy resin material is at least about 3 months, at least about 6 months, at least about 1 year, or even at least about 5 years. 
     
     
         12 ) The method according to  claim 3 , wherein the reformable epoxy resin material is recyclable. 
     
     
         13 ) The method according to  claim 1 , wherein the glass transition temperature of the reformable epoxy resin material is higher than room temperature but lower than 200° C. 
     
     
         14 ) The method according to  claim 1 , wherein the reformable epoxy resin material can be processed at a temperature of less than 200° C., or even less than 150° C. 
     
     
         15 ) The method according to  claim 10 , wherein the stiffness of the reformable epoxy resin material is substantially higher than the stiffness of a thermoplastic material without an epoxy component. 
     
     
         16 ) The method according to  claim 1 , wherein the reformable epoxy resin material is capable of receiving printed material prior to forming the composite structure whereby the printed material can be clearly viewed after formation of the composite structure. 
     
     
         17 ) The method according to  claim 1 , wherein the resulting composite structure is stampable. 
     
     
         18 ) The method according to  claim 1 , wherein the resulting composite structure includes natural fiber materials. 
     
     
         19 ) The method according to  claim 1 , wherein the resulting composite structure does not fail at greater than 2.5% strain during a three point bend test. 
     
     
         20 ) The method according to  claim 1 , wherein the resulting composite structure does not fail at greater than 3.5% strain during a three point bend test.