Patent ID: 6767626
Filing Date: 2004-07-27
Classification: C04B,Y10T

Abstract:
A process for protecting stone comprising:contacting stone with a substantially amorphous fluoropolymer comprising (a) 30 to 50 mole percent of repeat units of the formula â€”CF2â€”CF(CF3)â€”â€ƒâ€ƒ(I) â€ƒderived from hexafluoropropylene; (b) 25 to 50 mole percent of repeat units of the formula â€”CF2â€”CF2â€”â€ƒâ€ƒ(II) â€ƒderived from tetrafluoroethylene; and (c) about 10 to about 25 mol- % of repeat units selected from the group consisting of â€”CF2CFXâ€”, â€”CH2â€”CHRâ€”, â€”CH2CF2â€”â€ƒâ€ƒ(III) and mixtures thereof wherein X is H or perfluoroalkoxy having 1-20 carbons, and R is H, alkyl, alkoxy, perfluoroalkyl, F.