Patent ID: 8211264

Claim:
A method for preparing a transparent multilayer film laminate comprising at least a first film layer and a second film layer, the method comprising: A. providing a first film layer comprising a perfluorinated copolymer resin composition wherein i) the perfluorinated copolymer resin consists essentially of copolymerized units of tetrafluoroethylene and at least one perfluorinated comonomer and ii) at least one surface of the first film layer has been modified by a surface treatment; B. providing a second film layer comprising a polymeric material selected from the group consisting of α-olefin ethylenically unsaturated carboxylic acid copolymers, ionomers of α-olefin ethylenically unsaturated carboxylic acid copolymers, ethylene vinyl acetate copolymers, poly(vinyl acetals), polyurethanes, polyvinylchlorides, polyethylenes, polyolefin block copolymer elastomers, copolymers of α-olefins and ethylenically unsaturated carboxylic acid esters, silicone elastomers, epoxy resins, and combinations of two or more thereof; C. treating a surface of the second film layer with an aminosilane coupling agent to provide a surface-treated second film layer; D. contacting a treated surface of the surface-treated second film layer with the modified surface of the first film layer; and E. adhering the first film layer to the second surface-treated film layer by the application of heat and optionally pressure or vacuum to form a multilayer film laminate; wherein the multilayer film laminate is characterized by (i) having an average peel strength between the first film layer and the second surface-treated film layer of greater than 2 lbf/in, measured after exposing the multilayer film laminate to conditions of 85° C. and 85% relative humidity for 1000 hours with the proviso that when the second film layer comprises an ethylene vinyl acetate copolymer, the multilayer film laminate is maintained at a sufficient temperature for a time sufficient to crosslink the ethylene vinyl acetate copolymer prior to exposing the multilayer film laminate to conditions of 85° C. and 85% relative humidity for 1000 hours; and (ii) having a light transmission level, as a percentage of the light transmitted through air at wavelengths from 400 to 800 nm, as determined according to methods in ASTM E424, that exceeds that of a comparison standard laminate wherein the multilayer film laminate and the comparison standard laminate have the same structure and composition with the exception that the first film layer of the comparison standard laminate comprises an ethylene tetrafluoroethylene copolymer resin, the compositions of the first film layers of the multilayer film laminate and the comparison standard laminate being otherwise identical.