Patent ID: 6821454
Filing Date: 2004-11-23
Classification: C08G,C09K

Abstract:
A method for removing water from surfaces of substrata, comprising the steps of covering said surface with a composition having a specific weight higher than that of the water and subsequently removing water from the composition by skimming, wherein a composition essentially consisting of the following components is used:A) a non ionic additive having a fluoropolyether structure with a fluorinated T end group containing one chlorine atom, having the following formula: T-ORf(CFY)-Lâ€ƒâ€ƒ(I) â€ƒwherein L=Xâ€”CH2CH2(OCH2CH2)nBâ€ƒâ€ƒ(Ia) wherein: X=CH2O; CH2NRâ€³; CONRâ€³; CH2OCH2CH2NRâ€³; CH2OCOCH2O; B=OH; SH; NHRâ€³; OCH3; OCOCH3, with Râ€³=H; C1-3 alkyl, T is a fluorinated radical selected from ClCF2CF(CF3)â€”, CF3CFClCF2â€”, ClCF2CF2â€”, ClCF2â€”,Y=CF3 or F,Rf is a perfluoropolyether or fluoropolyether radical; the number average molecular weight of the fluoroether part T-ORfâ€” in the range 400-2,000, a ratio by weight (K) between the fluorinated part and an L part of the additive is in the range 1.50-4.00; n in formula (Ia) is such as the ratio (K) is in the range 1.50-4.00; B) a perfluoropolyether having number average molecular weight in the range 300-900, provided that a ratio (KI) between the number average molecular weight of the fluoropolyether part T-ORfâ€” of the additive A) and the number average molecular weight of component B) is higher than 1.60.