Stiffeners for use in footwear

Abstract

The present invention relates to a process and composition for stiffening materials for use in the manufacturing of footwear using a combination of stiffeners and adhesives.

1 . A sheet stiffener material for use in footwear comprising a low melting point plastic adhesive resin and a stiffening plastic resin combined in a one step extrusion process, wherein said sheet stiffener material is stiff, resilient and has adhesive properties.  
   
   
       2 . A stiffener material according to  claim 1 , wherein said low melting point plastic adhesive resin and said stiffening plastic resin form a homogenous blend.  
   
   
       3 . A stiffener material according to  claim 2 , wherein said low melting point plastic adhesive resin is polycaprolactone and said stiffening plastic resin is polyethylene teraphthalate glycol.  
   
   
       4 . A stiffener material according to  claim 3 , wherein the ratio of polyethylene teraphthalate glycol to polycaprolactone is from about 40/60 to about 60/40.  
   
   
       5 . A process for preparing a stiffener material for use in footwear comprising combining a low melting point plastic adhesive resin and a stiffening plastic resin in a single step to produce a stiffening material, wherein said stiffening material is stiff, resilient and has adhesive properties.  
   
   
       6 . The process according to  claim 5 , wherein said low melting point plastic adhesive and said stiffening plastic resin are co-extruded to form a sheet of stiffening material with a plastic resin core, wherein said core further comprises an exterior layer of a low melting point plastic adhesive resin.  
   
   
       7 . The process according to  claim 6 , wherein said low melting point plastic adhesive resin is polycaprolactone and said stiffening plastic resin Is polyethylene teraphthalate glycol.  
   
   
       8 . The process according to  claim 6 , wherein said low melting point plastic adhesive resin is polycaprolactone and said stiffening plastic resin is polyethylene teraphthalate.  
   
   
       9 . The process according to  claim 6 , wherein said low melting point plastic adhesive resin is ethylene methyl acrylate copolymer and said stiffening plastic resin is a copolyester.  
   
   
       10 . The process according to  claim 6 , wherein said low melting point plastic adhesive resin is a mixture of ethylene methyl acrylate copolymer and polycaprolactone and said stiffening plastic resin is a copolyester.  
   
   
       11 . The process according to  claim 6 , wherein said low melting point plastic adhesive resin is a mixture of ethylene methyl acrylate copolymer and a copolyester and said stiffening plastic resin is a copolyester.  
   
   
       12 . The process according to  claim 5 , wherein said low melting point plastic adhesive and said stiffening plastic resin are blended and then extruded to form a single homogenous stiffening material, wherein said stiffening materials is stiff, resilient and has adhesive properties.  
   
   
       13 . The process according to  claim 12 , wherein said low melting point plastic adhesive resin is polycaprolactone and said stiffening plastic resin is polyethylene teraphthalate glycol.