Method for preparing novel fluorinated organosiloxane copolymers

Claim 1

A method for preparing a fluorine-containing organosiloxane copolymer consisting essentially of repeating units of the formula R'CH 2 CH 2 Si(R") n O.sub.(3-n)/2, R(CH 3 ) 2 SiO 1/2 , SiO 4/2 , silicon-bonded hydroxyl groups, and optionally, (CH 3 ) 2 SiO units, said method comprising the steps of I. heating to a temperature of from 50° C. to the boiling point thereof of a liquid reaction mixture comprising (A) a fluorinated silane of the formula R'CH.sub.2 CH.sub.2 Si(R").sub.n X.sub.3-n, (B) a nonfluorinated benzene soluble organosiloxane copolymer consisting essentially of repeating units of the formula R(CH 3 ) 2 SiO 1/2 and SiO 4/2 in a molar ratio of from 0.6:1-1.1:1, respectively, at least 0.1% by weight of silicon-bonded hydroxyl groups, and, optionally, (CH 3 ) 2 SiO units, II. continuing heating of said liquid reaction mixture for a period sufficient to form said fluorine-containing organosiloxane copolymer, and III. removing any acidic byproducts generated during the reaction of (A) and (B), where R represents a saturated or ethylenically unsaturated hydrocarbon radical containing from 1 to 4 carbon atoms or a phenyl radical, R' represents a monovalent organic radical containing at least 4 perfluorinated carbon atoms, R" represents an alkyl radical containing from 1 to 3 carbon atoms or a phenyl radical, X represents a hydrolyzable group and n is 0, 1 or 2.

Claim 2

A method for preparing a fluorine-containing organosiloxane copolymer consisting essentially of repeating units of the formula R'CH 2 CH 2 Si(R") n O.sub.(3-n)/2, R(CH 3 ) 2 SiO 1/2 , SiO 4/2 , silicon-bonded hydroxyl groups, and optionally, (CH 3 ) 2 SiO units, said method comprising the steps of I. heating to a temperature of from 50° C. to the boiling point thereof of a liquid reaction mixture comprising (A) a fluorinated silane of the formula R'CH.sub.2 CH.sub.2 Si(R").sub.n X.sub.3-n, (B) a nonfluorinated benzene soluble organosiloxane copolymer consisting essentially of repeating units of the formula R(CH 3 ) 2 SiO 1/2 and SiO 4/2 in a molar ratio of from 0.6:1-1.1:1, respectively, at least 0.1% by weight of silicon-bonded hydroxyl groups, and, optionally, (CH 3 ) 2 SiO units, II. continuing heating of said liquid reaction mixture for a period sufficient to form said fluorine-containing organosiloxane copolymer, and III. removing any acidic byproducts generated during the reaction of (A) and (B), where R represents a saturated or ethylenically unsaturated hydrocarbon radical containing from 1 to 4 carbon atoms or a phenyl radical, R' represents a monovalent organic radical containing at least 4 perfluorinated carbon atoms, R" represents an alkyl radical containing from 1 to 3 carbon atoms or a phenyl radical, X represents a hydrolyzable group and n is 0, 1 or 2.