Composite sheet and manufacturing method for a foamed decorative sheet free of pvc and plasticizers

Abstract

A composite sheet and a manufacturing process for producing a decorative sheet using the composite sheet are provided. The composite sheet has a base layer and a foamable layer bonded to the base layer. The foamable layer includes 100 parts by weight of a polyolefin material having an elastic modulus of <0.1 GPa, 0.1-10 parts by weight of a foaming agent, and 0-200 parts by weight of additives. The foamable layer has a thickness of 0.05 to 0.3 mm.

What is claimed is: 
     
         1 . A composite sheet comprising:
 a base layer having an elastic modulus of >1 GPa; and   a foamable layer bonded to the base layer and including:
 100 parts by weight of a polyolefin material having an elastic modulus of <0.1 GPa; 
 0.1-10 parts by weight of a foaming agent; 
 0-200 parts by weight of additives; and, 
   said foamable layer having a thickness of 0.05 to 0.3 mm.   
     
     
         2 . The composite sheet of  claim 1 , wherein said polyolefin material is selected from the group consisting of thermoplastic elastomer polyolefins, ethylene vinyl acetate copolymers, and atactic polypropylene polymers, or mixtures thereof. 
     
     
         3 . The composite sheet of  claim 1 , wherein said foaming agent is selected from the group consisting of azodicarbonamide, an azodicarbonamide metal salt, hydrazodicarbonamide, sodium bicarbonate, trihydrazino-sym-triazine, pp′-oxybis-benzenesulfonylhydrazide, dinitroso-pentamethylene-tetramine,
 azobisisobutyl-odinitrile, p-toluenesulfonylhydrazide, and bisbenzenesulfonylhydrazide. 
 
     
     
         4 . The composite sheet of  claim 1 , wherein said additives are selected from the group consisting of catalysts, pigments, fillers, matting agents, microbial agents, UV stabilizers, fire retardants and release compounds. 
     
     
         5 . The composite sheet of  claim 4 , wherein:
 said additives include a catalyst; and,   said catalyst is selected from the group consisting of zinc oxide, barium ricinoleate, tin methoxy maleate, hydrated calcium silicate, calcium stearate, zinc stearate, lead acetate, zinc laurate, zinc octonoate, and cadmium amyl phosphite.   
     
     
         6 . The composite sheet of  claim 1 , wherein:
 said base layer is selected from the group consisting of paper, paper-like material, non-woven material, woven fabrics, nonwoven fabrics and plastic foils.   
     
     
         7 . The composite sheet of  claim 1 , wherein said polyolefin material is a polyolefin blend including polyolefins with an elastic modulus>0.1 GPa and polyolefins with an elastic modulus<0.1 GPa, such that a total elastic modulus of the polyolefin blend is <0.1 GPa. 
     
     
         8 . A method for producing a foamed decorative sheet, the method comprising the steps of:
 providing a composite sheet as claimed in  claim 1 ;   printing on the composite sheet; and   foaming of the composite sheet.   
     
     
         9 . A decorative sheet produced by the method of  claim 8 . 
     
     
         10 . The decorative sheet of  claim 9 , wherein the decorative sheet is a wall cover.