Multilayered polyolefin-based films having a layer comprising a crystalline block copolymer composite or a block copolymer composite resin

Abstract

Disclosed are multilayer film structures comprising a layer (B) that comprises a crystalline block copolymer composite (CBC) or a specified block copolymer composite (BC), comprising i) an ethylene polymer (EP) comprising at least 80 mol % polymerized ethylene; ii) an alpha-olefin-based crystalline polymer (CAOP) and iii) a block copolymer comprising (a) an ethylene polymer block comprising at least 80 mol % polymerized ethylene and (b) a crystalline alpha-olefin block (CAOB); and a layer C that comprises a polyolefin having at least one melting peak greater than 1255 C, the top facial surface of layer C in adhering contact with the bottom facial surface of layer B. Such multilayer film structure preferably comprises (A) a seal layer A having a bottom facial surface in adhering contact with the top facial surface of layer B. Such films are suited for use in electronic device (ED) modules comprising an electronic device such as a PV cell. Also disclosed is a lamination process to construct a laminated PV module comprising such multilayer film structures.

What is claimed is: 
     
         1 . A multilayer film structure comprising a layer (Layer B) and a bottom layer (Layer C), each layer having opposing facial surfaces in adhering contact with the other layer, wherein:
 B. Layer B comprises a crystalline block copolymer composite (CBC) or a specified block copolymer composite (BC), comprising:
 i) an ethylene polymer (EP) comprising at least 80 mol % polymerized ethylene; 
 ii) an alpha-olefin-based crystalline polymer (CAOP) and 
 iii) a block copolymer comprising (a) an ethylene polymer block comprising at least 80 mol % polymerized ethylene and (b) a crystalline alpha-olefin block (CAOB), 
 or a mixture of said composite(s); and 
   C. bottom Layer C comprises a polyolefin having at least one melting peak greater than 125° C. and has a top facial layer and a bottom facial surface, the top facial surface of Layer C in adhering contact with the bottom facial surface of Layer B.   
     
     
         2 . A multilayer film structure according to  claim 1  wherein the i) EP in Layer B comprises at least 80 mol % polymerized ethylene and the balance is polymerized propylene. 
     
     
         3 . A multilayer film structure according to  claim 1  wherein the block composite resin in Layer B is a crystalline block composite resin. 
     
     
         4 . A multilayer film structure according to  claim 1  wherein the Layer B block composite resin has a CAOB amount (in part (iii)) in the range of from 30 to 70 weight % of the CAOB. 
     
     
         5 . A multilayer film structure according to  claim 3  wherein the Layer B block composite resin has a CAOB amount (in part (iii)) in the range of from 40 to 60 weight % of the CAOB. 
     
     
         6 . A multilayer film structure according to  claim 1  where tie Layer B comprises a CBC having a CBCI of between 0.3 to 1.0 or a specified BC having a BCI of between 0.1 to 1.0. 
     
     
         7 . A multilayer film structure according to  claim 1  wherein propylene is the alpha-olefin in ii) and iii) in tie Layer B. 
     
     
         8 . A multilayer film structure according to  claim 1  wherein tie Layer B is a blend comprising greater than 40 weight percent CBC or specified BC. 
     
     
         9 . A multilayer film structure according to  claim 8  wherein tie Layer B is a blend further comprising one or more polyolefin selected from an ethylene octene plastomer, LLDPE and LDPE. 
     
     
         10 . A multilayer film structure according to  claim 1  wherein the CBC or specified BC of Layer B has a melt flow rate of from 3 to 15 g/10 min (at 230° C./2.16 Kg). 
     
     
         11 . The multilayer film structure according to  claim 1  comprising:
 (A) a seal layer A having a top facial surface and a bottom facial surface, the bottom facial surface in adhering contact with the top facial surface of layer B. 
 
     
     
         12 . A multilayer film structure according to  claim 11  in which the top layer A comprises a linear low density polyethylene (LLDPE). 
     
     
         13 . A multilayer film structure according to  claim 12  in which the top layer A comprises a blend formulation of a linear low density polyethylene (LLDPE) comprising a polar ethylene copolymer in an amount of from 10 to 45 weight %. 
     
     
         14 . A multilayer film structure according to  claim 11  in which the top layer A comprises a BC or CBC and the layer composition is different from layer B composition. 
     
     
         15 . A multilayer film structure according to  claim 1  in which the bottom layer C comprises a propylene-based polymer. 
     
     
         16 . A multilayer film structure according to  claim 9  in which the bottom layer C comprises a propylene-based polymer having a heat of fusion value of at least 60 Joules per gram (J/g). 
     
     
         17 . A multilayer film structure according to  claim 1  wherein Layer A is from 0 to 200 micrometer (μm) in thickness; Layer B is from 25 to 100 μm in thickness; and Layer C is from 150 to 350 μm in thickness. 
     
     
         18 . A multilayer film structure according to  claim 1  comprising a top seal Layer A comprising a blend formulation of a linear low density polyethylene (LLDPE) comprising a polar ethylene copolymer in an amount of from 10 to 45 weight %, a bottom Layer C comprising a propylene-based polymer and a Layer B between Layer A and Layer C comprising a crystalline block copolymer composite (CBC) comprising i) an ethylene polymer (EP) comprising at least 93 mol % polymerized ethylene; ii) a crystalline propylene polymer and iii) a block copolymer comprising (a) an ethylene polymer block comprising at least 93 mol % polymerized ethylene and (b) a crystalline propylene polymer block. 
     
     
         19 . An electronic device (ED) module comprising an electronic device and a multilayer film structure according to  claim 1 . 
     
     
         20 . A lamination process to construct a laminated PV module comprising the steps of:
 (1.) bringing at least the following layers into facial contact in the following order:
 (a) a light-receiving top sheet layer having an exterior light-receiving facial surface and an interior facial surface; 
 (b) a light transmitting thermoplastic polymer encapsulation layer, having one facial surface directed toward the top sheet layer and one directed toward a light-reactive surface of a PV cell; 
 (c) a PV cell have a light reactive surface; 
 (d) a second encapsulating film layer; and 
 (e) a backsheet layer comprising a multilayer film structure according to  claims 1 ; and 
   (2.) heating and compressing the layers of Step (1.) at conditions sufficient to create the needed adhesion between the layers and, if needed in some layers or materials, initiation of their crosslinking.