US Patent 7229503 Treatment of glass substrata with (per) fluoropolyether compounds

Use in the treatment of glass substrata of mono- and bi-functional (per)fluoropolyether compounds having the following structures:Rf—CFY-L-W  (I)W-L-YFC—O—Rf—CFY-L-W  (II)wherein:L is a linking organic group —CO—NR′—(CH2)q—, with R′=H or C1-C4 alkyl; q=1-8; Y=F, CF3;W is a —Si(R1)α(OR2)3−α group with α=0, 1, 2;R1 and R2 equal to or different from each other are C1-C6 alkyl groups, optionally containing one or more ether O atoms, C6-C10 aryl groups, C7-C12 alkyl-aryl or aryl-alkyl groups;Rf has a number average molecular weight in the range 350-5,000, and comprises repeating units of the type:(CFXO),(CF2CF2O),(CF(CF3)CF2O),(CF2CF(CF3)O),wherein X=F, CF3.