SOLAR CELL MODULES COMPRISING ENCAPSULANT SHEETS WITH LOW HAZE AND HIGH MOISTURE RESISTANCE

摘要

A solar cell module comprising a solar cell layer and an ionomer sheet comprising a sodium/zinc mixed ionomer that is the neutralization product of a precursor acid copolymer; wherein the precursor acid copolymer comprises copolymerized units of an α-olefin having 2 to 10 carbon atoms and about 20 to about 30 wt % of copolymerized units of an α,&bgr;-ethylenically unsaturated carboxylic acid having 3 to 8 carbon atoms based on the total weight of the precursor acid copolymer; wherein the precursor acid copolymer has a melt flow rate of about 70 to about 1000 g/10 min, as determined in accordance with ASTM D1238 at 190° C. and 2.16 kg; and wherein when about 40% to about 90% of the total content of the carboxylic acid groups present in the precursor acid copolymer are neutralized to carboxylate groups to comprise carboxylate groups and counterions that consist essentially of sodium ions, the resulting sodium ionomer has a freeze enthalpy that is not detectable or that is less than about 3.0 j/g, when determined by differential scanning calorimetry in accordance with ASTM D3418.