Silicone polymer termination

Claim 1

A method of producing a polydiorganosiloxane free of hydroxyl groups comprising (A) heating 100 parts by weight of polydiorganosiloxane containing alkali metal to a temperature of from room temperature to 160° C., then (B) adding sufficient acidic or acid producing phosphoric component of the formula ##STR6## where X, Y, and Z are hydrogen or SiR 3 , and R is a monovalent hydrocarbon radical or halogenated hydrocarbon radical having 1 to 6 carbon atoms, to give a mole ratio of alkali metal from the polydioganosiloxane in (A) to the phosphorous in (B) of from 1:1 to 1:10, and from 0.2 to 1.0 parts by weight of silylamide component of the formula R.sub.3 SiNR'C(O)R" where R is hydrogen, monovalent hydrocarbon radical or halogenated hydrocarbon radical having from 1 to 6 carbon atoms, and R' and R" are hydrogen, monovalent hydrocarbon radical having from 1 to 6 carbon atoms, or R 3 Si- radical, and mixing with the exclusion of atmospheric moisture, then (C) holding at temperature for a sufficient time to allow the removal of the hydroxyl groups, then (D) devolatilizing to reduce the level of silylamide or volatile products to a level of less than 0.15 part by weight, to yield a polydiorganosiloxane having a slight change in viscosity and no hydroxyl groups.

Claim 2

A method of producing a polydiorganosiloxane free of hydroxyl groups comprising (A) heating 100 parts by weight of polydiorganosiloxane containing alkali metal to a temperature of from room temperature to 160° C., then (B) adding sufficient acidic or acid producing phosphoric component of the formula ##STR6## where X, Y, and Z are hydrogen or SiR 3 , and R is a monovalent hydrocarbon radical or halogenated hydrocarbon radical having 1 to 6 carbon atoms, to give a mole ratio of alkali metal from the polydioganosiloxane in (A) to the phosphorous in (B) of from 1:1 to 1:10, and from 0.2 to 1.0 parts by weight of silylamide component of the formula R.sub.3 SiNR'C(O)R" where R is hydrogen, monovalent hydrocarbon radical or halogenated hydrocarbon radical having from 1 to 6 carbon atoms, and R' and R" are hydrogen, monovalent hydrocarbon radical having from 1 to 6 carbon atoms, or R 3 Si- radical, and mixing with the exclusion of atmospheric moisture, then (C) holding at temperature for a sufficient time to allow the removal of the hydroxyl groups, then (D) devolatilizing to reduce the level of silylamide or volatile products to a level of less than 0.15 part by weight, to yield a polydiorganosiloxane having a slight change in viscosity and no hydroxyl groups.

Claim 3

A method of producing a polydiorganosiloxane free of hydroxyl groups comprising (A) heating 100 parts by weight of diorganocyclosiloxane to a temperature of from room temperature to 160° C. in the presence of an alkaline polymerization catalyst for a time sufficient to polymerize to the desired molecular weight, to give a polydiorganosiloxane, then (B) adding sufficient acidic or acid producing phosphoric component of the formula ##STR7## where X, Y, and Z are hydrogen of SiR 3 , and R is a monovalent hydrocarbon radical or halogenated hydrocarbon radical having 1 to 6 carbon atoms, to give a mole ratio of alkali metal from the polydiorganosiloxane in (A) to the phosphorous in (B) of from 1:1 to 1:10, and from 0.2 to 1.0 parts by weight of silylamide component of the formula R.sub.3 SiNR'C(O)R" wherein R is hydrogen, monovalent hydrocarbon radical or halogenated hydrocarbon radical having from 1 to 6 carbon atoms, and R' and R" are hydrogen, monovalent hydrocarbon radical having from 1 to 6 carbon atoms, or R 3 Si- radical, and mixing with the exclusion of atmospheric moisture, then (C) holding at temperature for a sufficient time to allow the removal of the hydroxyl groups, then (D) devolatilizing to reduce the level of silylamide or volatile products to a level of less than 0.15 part by weight, to yield a polydiorganosiloxane having a slight change in viscosity and a reduced number of hydroxyl groups.

Claim 4

A method of producing a polydiorganosiloxane free of hydroxyl groups comprising (A) heating 100 parts by weight of diorganocyclosiloxane to a temperature of from room temperature to 160° C. in the presence of an alkaline polymerization catalyst for a time sufficient to polymerize to the desired molecular weight, to give a polydiorganosiloxane, then (B) adding sufficient acidic or acid producing phosphoric component of the formula ##STR7## where X, Y, and Z are hydrogen of SiR 3 , and R is a monovalent hydrocarbon radical or halogenated hydrocarbon radical having 1 to 6 carbon atoms, to give a mole ratio of alkali metal from the polydiorganosiloxane in (A) to the phosphorous in (B) of from 1:1 to 1:10, and from 0.2 to 1.0 parts by weight of silylamide component of the formula R.sub.3 SiNR'C(O)R" wherein R is hydrogen, monovalent hydrocarbon radical or halogenated hydrocarbon radical having from 1 to 6 carbon atoms, and R' and R" are hydrogen, monovalent hydrocarbon radical having from 1 to 6 carbon atoms, or R 3 Si- radical, and mixing with the exclusion of atmospheric moisture, then (C) holding at temperature for a sufficient time to allow the removal of the hydroxyl groups, then (D) devolatilizing to reduce the level of silylamide or volatile products to a level of less than 0.15 part by weight, to yield a polydiorganosiloxane having a slight change in viscosity and a reduced number of hydroxyl groups.