Recyclable label foil

Abstract

A label foil is disclosed that is suitable for in-mold labeling, has a high stiffness, is well suited for cutting and is recyclable. The top layers of the label foil are made of polyethylene. Both top layers have about the same thickness and the core layer has a thickness that is about 5 times to 20 times that of one top layer.

1 . Recyclable label foil ( 3 ) with at least 
 one first top layer ( 3 . 1 ) made of polyethylene,    one core layer ( 3 . 2 ) made of polypropylene, and    one second top layer ( 3 . 3 ) made of polyethylene,    where the top layers ( 3 . 1 ,  3 . 3 ) each have about the same thickness and where the core layer ( 3 . 2 ) has about 5 times to 20 times the respective thickness of one top layer ( 3 . 1 ,  3 . 3 ).    
     
     
         2 . Recyclable label foil ( 3 ) as set forth in  claim 1 , characterized in that 
 the top layers ( 3 . 1 ,  3 . 3 ) are made of high density polyethylene (HDPE) with a density p of 0.930 to 0.960 g/cm 3  and a melt flow index MFI (DIN 53735, 190° C./2.16 kg test conditions) of 3 to 7 g/10 min. and have a thickness of 2 to 10 μm, preferably of 3 to 7 μm,    the core layer ( 3 . 2 ) is made of polypropylene with a melt flow index MFI (DIN 53735, 190° C./2.16 kg test conditions) of 0.2 to 4 g/10 min, preferably of 0.2 to 2 g/10 min.    the label foil ( 3 ) exhibits an overall thickness of 40 to 80 μm, preferably of 50 to 70 μm, and    the melting point of the core layer ( 3 . 2 ) is greater than 155° C.    
     
     
         3 . Recyclable label foil ( 3 ) for in-mold labeling of synthetic containers to be produced by extrusion blow molding, with at least three co-extruded layers, where at least one core layer is located between two top layers and where at least one of the top layers consists of a sealable synthetic material that softens at or below the temperature of the blow mold, characterized in that 
 the top coatings ( 3 . 1 ,  3 . 3 ) are made of polyethylene and the core layer ( 3 . 2 ) of polypropylene, and    the two top layers ( 3 . 1 ,  3 . 3 ) each have about the same thickness and in that the core layer ( 3 . 2 ) has about 5 times to 20 times the respective thickness of one top layer ( 3 . 1 ,  3 . 3 ).    
     
     
         4 . Recyclable label foil as set forth in  claim 3 , characterized in that the synthetic material of the top layers ( 3 . 1 ,  3 . 3 ) exhibits a melt flow index MFI (DIN 53735, 190° C./2.16 kg test conditions) of 5 to 30 g/10 min., preferably of 10 to 20 g/10 min.  
     
     
         5 . Recyclable label foil as set forth in  claim 3  or  4 , characterized in that the top layers ( 3 . 1 ,  3 . 3 ) are made of low density polyethylene (PE-LD) with a density of 0.915 to 0.920 g/cm 3 .  
     
     
         6 . Recyclable label foil as set forth in  claim 3  or  4 , characterized in that the top layers ( 3 . 1 ,  3 . 3 ) are made of low density linear polyethylene polymerized with metallocene catalysts (PE-LLD) with a density of 0.915 to 0.985 g/cm 3 .  
     
     
         7 . Recyclable label foil as set forth in  claim 3  or  4 , characterized in that the top layers ( 3 . 1 ,  3 . 3 ) are made of a mixture of low density polyethylene (PE-LD) with a density of 0.915 to 0.985 g/cm 3  and low density linear polyethylene (PE-LLD) with a density of 0.935 to 0.985 g/cm 3 .  
     
     
         8 . Recyclable label foil as set forth in  claim 3  or  4 , characterized in that the top layers ( 3 . 1 ,  3 . 3 ) are made of an ethylene vinyl acetate copolymer (EVA) with a vinyl acetate content of 25 to 40 percent in weight.  
     
     
         9 . Recyclable label foil as set forth in  claim 3  or  4 , characterized in that the top layers ( 3 . 1 ,  3 . 3 ) are made of an ethylene copolymer or an ethylene terpolymer with a sealing temperature range from 60 to 85° C.  
     
     
         10 . Recyclable label foil ( 3 ) as set forth in one of the aforementioned claims, characterized in that at least the core layer ( 3 . 2 ) is filled with mineral filler materials such as chalk, lime, titanium oxide or talc with a fill content of 5 to 40 percent in weight.  
     
     
         11 . Recyclable label foil ( 3 ) as set forth in one of the aforementioned claims, characterized in that the filler material is talc with an average particle size of 2 to 20 μm, preferably with a particle size of 2 to 5 μm.  
     
     
         12 . Recyclable label foil ( 3 ) as set forth in one of the aforementioned claims, characterized in that the label foil ( 3 ) is a five-layer co-extruded product, where a coextruded adhesion-supporting layer ( 7 . 1 ,  7 . 2 ) with a thickness of 5 to 8 μm is located between each of the top layers ( 3 . 1 ,  3 . 3 ) and the core layer ( 3 . 2 ).