Halogen-free, printable, multilayered shrink films and articles encapsulated therein

Abstract

The present invention relates to a halogen-free, multilayered heat shrink film comprising (A) a core layer comprising a copolymer of ethylene or propylene with an alpha olefin and the core having an upper and lower surface, (B) a skin layer on the upper surface of the core layer, wherein the skin layer comprises a polyolefin or polyolefin blend and (C) a printable layer on the lower surface of the core layer, wherein the shrinkage of the film is at least about 30%. The invention also relates to articles, including cylindrical articles such as batteries. The films have good shrinkage and avoids end puckering. Additionally, the films are printable, even with gravure printing. The films and labels produced thereform may be applied at high speeds and have good heat stability.

1 . A halogen-free, multilayered heat shrink film comprising (A) a core layer comprising a copolymer of ethylene or propylene with an alpha olefin and the core having an upper and lower surface, (B) a skin layer on the upper surface of the core layer, wherein the skin layer comprises a polyolefin or polyolefin blend and (C) a printable layer on the lower surface of the core layer, wherein the shrinkage of the film is at least about 30%.  
     
     
         2 . The film of  claim 1  wherein (A) is a copolymer of ethylene or propylene and butene or hexene.  
     
     
         3 . The film of  claim 2  wherein the copolymer has a butene content of about 3% to about 20%.  
     
     
         4 . The film of  claim 1  wherein the core layer further comprises an olefin homopolymer.  
     
     
         5 . The film of  claim 4  wherein the olefin homopolymer is propylene or butylene homopolymer.  
     
     
         6 . The film of  claim 1  wherein (B) is polypropylene, polybutene, or a propylene and butene copolymer.  
     
     
         7 . The film of  claim 1  wherein (B) is a polyolefin blend of a polyolefin homopolymer and a copolymer of ethylene or propylene and an alpha-olefin.  
     
     
         8 . The film of  claim 1  wherein (B) is a polyolefin blend of a propylene homopolymer and a copolymer of propylene and an alpha olefin.  
     
     
         9 . The film of  claim 1  wherein (C) is blend of a polyolefin and a soft polar additive.  
     
     
         10 . The film of  claim 9  wherein the polyolefin is an ethylene or propylene homopolymer or a copolymer of ethylene and propylene.  
     
     
         11 . A halogen-free, multilayered heat shrink film comprising (A) a core layer comprising a blend of (1) a copolymer of ethylene or propylene with an alpha olefin and (2) a homopolymer of an olefin, and having an upper and lower surface, (B) a skin layer on the upper surface of the core layer, wherein the skin layer comprises a polyolefin homopolymer or a blend of a polyolefin homopolymer and a copolymer of ethylene or propylene and an alpha olefin and (C) a printable layer on the lower surface of the core layer, wherein the printable layer comprises a blend of a polyolefin and a soft polar additive, wherein the shrinkage of the film is at bast about 35%.  
     
     
         12 . The film of  claim 11  wherein the copolymer of (1) is a propylene and butene copolymer.  
     
     
         13 . The film of  claim 11  wherein homopolymer of (2) is a polybutene.  
     
     
         14 . The film of  claim 11  wherein the polyolefin homopolymer is polypropylene or polybutene and the copolymer is a propylene butene copolymer.  
     
     
         15 . The film of  claim 11  wherein the polyolefin is a polypropylene or polyethylene and the soft polar additive is ethylene vinyl acetate.  
     
     
         16 . An article encapsulated with a multilayer heat shrink film of  claim 1 .  
     
     
         17 . A article encapsulated with a multilayer heat shrink film of  claim 10 .  
     
     
         18 . The article of  claim 16 , wherein the article is a battery.  
     
     
         19 . The article of  claim 17 , wherein the article is a battery.