Multilayer Film

Abstract

A solar panel backside film used in solar panel constructions. The film comprises a PET film having a net peak area as measured by differential scanning calorimetry of about −15 J/g to about 5 J/g measured from the endpoint of the glass transition (Tg) up to 230° C., and an additive to opacify the PET film. A polymeric layer is adhered to the PET film to create a solar panel backside film. The solar panel backside film generally has a reflectivity of 50% or greater at a point in the visible range of light. Additionally, the solar panel backside film, when applied to a solar panel and exposed to 2000 hours at 85° C. and 85% relative humidity, does not result in exfoliation or visible cracks in the PET film.

1 . A film, comprising:
 (a) a polyethylene terephthalate film having an intrinsic viscosity of 0.60 or greater; and   (b) at least one other polymeric layer adhered to the polyethylene terephthalate to create a solar film, wherein the solar film when applied to a solar panel and exposed to 2000 hours of 85° C. and 85% relative humidity, the polyethylene terephthalate film does not exhibit visible cracks or exfoliation.   
     
     
         2 . The film according to  claim 1 , wherein the film exhibits a shrinkage of less than 1% in the machine direction measured at 150° C. and a reflectivity in the visible light range of 70% or greater. 
     
     
         3 . A solar panel comprising:
 (a) glass,   (b) a plurality of solar cells encapsulated in a polymer and adhered to the glass; and   (c) the film according to  claim 1  adhered to the polymer on a surface opposite the glass.