Chlorine-contg. polysiloxane(s) - prepd. by hydrolysis of chloro:silane(s) in the presence of polysiloxane(s) and per:fluoroalkane sulphonic acid

摘要

Linear or branched, calibrated Cl-contg. polyorganosiloxanes are prepd. by partial hydrolysis of >=1 chlorosilane RaR1bSiCl(4-a-b) or their partial hydrolysates in the presence of >=1 polyorganosiloxane of formula (R2R11SiO1/2)-(RR11SiO)(R11SiO3/2)(SiO2) (I) (where a and b are 0-3 and a+b is not >3; R and R1 are H or opt. halogen or cyano substd. is not >18C monovalent (un)satd. aliphatic or aromatic hydrocarbon gp.; R11 is as R, Cl or OH and the ratio of Cl contg. Si atoms to non-Cl contg. Si atoms is 8:1-5:1 and the total number of all Si Cl gps. is greater than the number of all Si OH gps.) and in the presence of 0.05-1wt. % (w.r.t. Si cpd.) perfluoroalkane sulphonic acid. Addition of water can be carried out uninterrupted without the need for much cooling aggregates to prevent escape of gaseous HCl due to the low amt. of chlorosilane in (I). Due to the lower amt. of HCl formation there is a reduction in the use of HCl washers. The prod. can be reacted with active H contg. cpds. e.g. to form polyether-polysiloxane copolymers which due to their surface active properties can be used as e.g. polyurethane foam stabilisers.