abstract |
An alcoholic fluoroalkyl-functional group containing organosiloxane based composition is prepared by the controlled hydrolysis of at least one fluoroalkyl-functional group containing organosilane of formula I:in which R1 is a mono, oligo- or perfluorinated alkyl group having 1-9 C atoms or a mono-, oligo- or perfluorinated aryl group, Y is a CH2, O or S group, R2 and R are each independently a linear, branched or cyclic alkyl group having 1-8 C atoms or an aryl group and x=0, 1 or 2 and y=0, 1 or 2, where (x+y)<=2, at a temperature in the range of 0-120° C. over a period of 0.5-24 hours and with thorough mixing in an alcoholic medium which contains water and a weak mono- or polybasic acid or a weak base or a weak mono- or polybasic acid and a weak base or an acid or basic salt, the water employed and the alkoxysilane employed being in a molar ratio of 2-500:1. |