Method for the preparation of alkoxy-containing organopolysiloxane

Claim 1

A method for the preparation of an alkoxy-terminated organopolysiloxane which comprises the successive steps of: (a) reacting a silanol-terminated diorganopolysiloxane represented by the general formula HO--SiR.sup.1.sub.2 --O.sub.n H, in which each R 1 is a monovalent group selected from the class consisting of methyl, vinyl, phenyl and 3,3,3-trifluoropropyl groups and the subscript n is a positive integer, with an organosilane compound represented by the general formula R.sup.3 Si(O--N═X).sub.3, in which R 3 is a monovalent group selected from the class consisting of methyl, ethyl, propyl, vinyl, phenyl and 3,3,3-trifluoropropyl groups and X is a divalent group represented by the general formula ═CR 4 2 , R 4 being a halogen-substituted or unsubstituted monovalent hydrocarbon group, or ##STR5## R 5 being a halogen-substituted or unsubstituted divalent hydrocarbon group, in a molar ratio of the silane compound to the silanol groups in the diorganopolysiloxane of at least 1 under a substantially anhydrous condition to form an intermediate oxime-terminated diorganopolysiloxane represented by the general formula (X═N--O).sub.2 (R.sup.3)Si--O--SiR.sup.1.sub.2 --O.sub.n Si(R.sup.3)(O--N═X).sub.2, in which R 1 , R 3 , X and n each have the same meaning as defined above; and (b) reacting the intermediate oxime-terminated diorganopolysiloxane with a monohydric alcohol represented by the general formula R.sup.6 OH, in which R 6 is a monovalent hydrocarbon group having 1 to 8 carbon atoms, in a molar ratio of the monohydric alcohol to the oxime groups of the formula --O--N═X in the intermediate oxime-terminated diorganopolysiloxane of at least 1 to form an alkoxy-terminated diorganopolysiloxane represented by the general formula (R.sup.6 O).sub.2 (R.sup.3)Si--O--SiR.sup.1.sub.2 --O.sub.n Si(R.sup.3)(OR.sup.6).sub.2, in which R 1 , R 3 , R 6 and n each have the same meaning as defined above.

Claim 2

A method for the preparation of an alkoxy-terminated organopolysiloxane which comprises the successive steps of: (a) reacting a silanol-terminated diorganopolysiloxane represented by the general formula HO--SiR.sup.1.sub.2 --O.sub.n H, in which each R 1 is a monovalent group selected from the class consisting of methyl, vinyl, phenyl and 3,3,3-trifluoropropyl groups and the subscript n is a positive integer, with an organosilane compound represented by the general formula R.sup.3 Si(O--N═X).sub.3, in which R 3 is a monovalent group selected from the class consisting of methyl, ethyl, propyl, vinyl, phenyl and 3,3,3-trifluoropropyl groups and X is a divalent group represented by the general formula ═CR 4 2 , R 4 being a halogen-substituted or unsubstituted monovalent hydrocarbon group, or ##STR5## R 5 being a halogen-substituted or unsubstituted divalent hydrocarbon group, in a molar ratio of the silane compound to the silanol groups in the diorganopolysiloxane of at least 1 under a substantially anhydrous condition to form an intermediate oxime-terminated diorganopolysiloxane represented by the general formula (X═N--O).sub.2 (R.sup.3)Si--O--SiR.sup.1.sub.2 --O.sub.n Si(R.sup.3)(O--N═X).sub.2, in which R 1 , R 3 , X and n each have the same meaning as defined above; and (b) reacting the intermediate oxime-terminated diorganopolysiloxane with a monohydric alcohol represented by the general formula R.sup.6 OH, in which R 6 is a monovalent hydrocarbon group having 1 to 8 carbon atoms, in a molar ratio of the monohydric alcohol to the oxime groups of the formula --O--N═X in the intermediate oxime-terminated diorganopolysiloxane of at least 1 to form an alkoxy-terminated diorganopolysiloxane represented by the general formula (R.sup.6 O).sub.2 (R.sup.3)Si--O--SiR.sup.1.sub.2 --O.sub.n Si(R.sup.3)(OR.sup.6).sub.2, in which R 1 , R 3 , R 6 and n each have the same meaning as defined above.