Bright white protective laminates

Abstract

Laminates of having a first outer layer of weatherable film, at least one mid layer, and a second outer layer of ethylene vinyl acetate containing an opacifying quantity of white pigment. The laminates are particularly useful for protecting photovoltaic cells, solar panels, and circuit boards. In photovolteic cells, the laminates result in increased power generation.

1 . A laminate comprising, and bonded together in the order specified, 
 (a) a first outer layer of weatherable film;    (b) at least one mid-layer selected from at least one of the group consisting of (i) poly(chlorotrifluoro ethylene), (ii) polymeric film coated on one or both surfaces with liquid crystal polymer, (iii) liquid crystal polymers; (iv) metal foil; and (v) polyester; and    (c) a second outer layer consisting essentially of ethylene vinyl acetate copolymer substantially free from cross-linking agent and having about from 3 to 15 weight % white opacifying pigment.    
     
     
         2 . A laminate of  claim 1  the weatherable film is selected from the group consisting of polyvinylidene fluoride, pigmented ionomers, aliphatic urethanes, weatherable grade polyesters, and polyvinyl fluoride.  
     
     
         3 . A laminate of  claim 2  wherein the weatherable film consists essentially of polyvinyl fluoride.  
     
     
         4 . A laminate of  claim 1  wherein the second outer layer has about from 5 to 12 weight % white opacifying pigment.  
     
     
         5 . A laminate of  claim 1  wherein the layers are adhesively bonded.  
     
     
         6 . A laminate of  claim 1  wherein at least one of the outer layers is adhesively bonded to at least one middle layer.  
     
     
         7 . A laminate of  claim 1  wherein the first outer layer has a thickness of about from 15 to 50 microns.  
     
     
         8 . A laminate of  claim 3  wherein the second outer layer has an optical density of at least about 1.0.  
     
     
         9 . A laminate of  claim 1  wherein the at least one mid-layer has a thickness of about from 10 to 50 microns.  
     
     
         10 . A laminate of  claim 9  wherein the at least one mid-layer has a thickness of about 24 microns.  
     
     
         11 . A laminate of  claim 1  wherein the second outer layer has a thickness of about from 50 to 200 microns.  
     
     
         12 . A laminate of  claim 1  wherein the ethylene vinyl acetate copolymer comprises about from 2 to 33 percent by weight of vinyl acetate.  
     
     
         13 . A laminate of  claim 12  wherein the ethylene vinyl acetate copolymer comprises about from 2 to 8 percent by weight of vinyl acetate.  
     
     
         14 . A laminate of  claim 1  wherein the second outer layer is at least about 99% opaque to ultraviolet light.  
     
     
         15 . A laminate of  claim 1  wherein the middle layer consists essentially of poly(chlorotrifluoro ethylene).  
     
     
         16 . A laminate of  claim 1  wherein the middle layer consists essentially of polyester film coated on one or both surfaces with polyvinylidene chloride.  
     
     
         17 . A laminate of  claim 1  wherein the middle layer consists essentially of polyester film coated on one or both surfaces with liquid crystal polymer.  
     
     
         18 . A laminate of  claim 1  wherein the middle layer consists essentially of liquid crystal polymer.  
     
     
         19 . A solar panel comprising a plurality of photovoltaic cells and a laminate of  claim 1 .  
     
     
         20 . A solar panel of  claim 18  wherein the second outer surface of the laminate is bonded to the solar panel.