Lidstock material having improved sealability and peelability to wide classes of materials

Abstract

A material that can be used as a lid ( 12 ) on a container ( 14, 40 ), the lid containing a solid substrate ( 30 ) and a peelable and heat sealable film ( 32 ) which contains a mixture of at least aliphatic-aromatic copolyester, inorganic filler, butene-1 polymer and ethylene-vinyl acetate copolymer, where the substrate ( 30 ) is preferably made of aluminum.

1 . A peelable and heat sealable material suitable for bonding to a wide variety of substrates, comprising a solid substrate joined to a film, the film comprising: 
 a.) aliphatic-aromatic copolyester;    b.) particulate inorganic filler;    c.) butene-1 polymer; and    d.) ethylene-vinylacetate copolymer.    
   
   
       2 . The material of  claim 1 , wherein, said substrate material is a lidstock material and comprises at least one material selected from metal foil, plastic, and paper.  
   
   
       3 . The material of  claim 1 , wherein said substrate comprises aluminum foil.  
   
   
       4 . The material of  claim 1 , wherein said inorganic filler comprises talc, silica, or alumina.  
   
   
       5 . The material of  claim 1 , wherein said material is bondable to all of PVC, PET and PVDC.  
   
   
       6 . The material of  claim 1 , wherein said film comprises about 25 wt. % to about 50 wt. % of aliphatic-aromatic copolyester.  
   
   
       7 . The material of  claim 1 , wherein said film comprises at least about 5 wt. % of both butene-1 polymer and ethylene-vinyl acetate copolymer.  
   
   
       8 . The material of  claim 1 , wherein said film comprises from about 10 wt. % to about 30 wt. % of butene-1 polymer and from about 10 wt. % to about 30 wt. % of ethylene-vinyl acetate copolymer.  
   
   
       9 . The lidstock material of  claim 1 , wherein said film comprises about 20-30 wt. % of the inorganic filler.  
   
   
       10 . The lidstock material of  claim 1 , wherein said filler has a particle size of from about 0.5 micrometer to 10 micrometer and contains from about 0.5 wt. % to 5 wt. %, based on the weight of the filler, of a carboxylic acid.  
   
   
       11 . The material of  claim 1 , wherein said material is bondable to PS, PP and PE as well as PVC, PET and PVDC.  
   
   
       12 . The material of  claim 9 , wherein said filler is selected from the group consisting of talc, alumina, silica and mixtures thereof talc having an average particle size of from 0.5 micrometers to 10 micrometers.  
   
   
       13 . A lid for a plastic container comprising the lidstock material of  claim 2 .  
   
   
       14 . A container comprising a plastic body having an edge defining an opening and a flange extending radially outwardly of said opening, and a lid comprising the lidstock material of  claim 2  heat sealed to said flange.  
   
   
       15 . The container of  claim 13 , wherein said substrate comprises aluminum foil.