Scavengers for ammonia in RTV compositions

Claim 1

A stable, one-package, substantially anhydrous and substantially acid-free, room temperature vulcanizable organopolysiloxane composition stable under ambient conditions in the substantial absence of moisture over an extended period of time and convertible to a tack-free elastomer, comprising: (A) an organopolysiloxane wherein the silicon atom at each chain end is terminated with at least two alkoxy radicals; (B) an effective amount of condensation catalyst; (C) a stabilizing amount of a silicon-nitrogen compound for scavenging hydroxy radicals, said silicon-nitrogen compound releasing ammonia as a by-product of the hydroxy-scavenging reaction; and (D) an effective amount of a scavenger for said ammonia by-product selected from the group consisting of molecular sieves and acids and mixtues thereof.

Claim 12

A method of making a one-package and substantially acid-free room temperature vulcanizable composition curable to the solid elastomeric state, which method comprises agitating under substantially anhydrous conditions at a temperature in the range of from about 0° C. to about 180° C., a room temperature vulcanizable material selected from (i) a mixture comprising: (A) 100 parts of a silanol terminated polydiorganosiloxane; (B) a stabilizing amount of a silicon-nitrogen compound for scavenging hydroxy radicals, said silicon-nitrogen compound releasing ammonia as a by-product of the hydroxy-scavenging reaction; (C) 0 to 10 parts of a crosslinking silane of the formula ##STR19## (D) an effective amount of a condensation catalyst; and (E) an effective amount of a scavenger for said ammonia by-product of the hydroxy-scavenging reaction selected from the group consisting of molecular sieves and acids and mixtures thereof; and (ii) a mixture comprising (A) 100 parts of a polyalkoxy-terminated polydiorganosiloxane base polymer; (B) 0 to 10 parts of a crosslinking silane of the formula ##STR20## (C) an effective amount of a condensation catalyst; (D) a stabilizing amount of a silicon-nitrogen compound for scavenging hydroxy radicals, said silicon-nitrogen compound releasing ammonia as a by-product of the hydroxy-scavenging reaction; and (E) an effective amount of a scavenger for said ammonia by-product of the hydroxy-scavenging reaction selected from the group consisting of molecular sieves and acids and mixtures thereof; where R 1 is a C 1-8 aliphatic organic radical selected from the group consisting of alkyl, alkylether, alkylester, alkylketone, and alkylcyano or a C 7-13 monovalent substituted or unsubstituted hydrocarbon radial, R 2 is a C 1-13 monovalent substituted or unsubstituted hydrocarbon radical, and e equals 0 or 1.

Claim 13

A method of making a one-package and substantially acid-free room temperature vulcanizable composition curable to the solid elastomeric state, which method comprises agitating under substantially anhydrous conditions at a temperature in the range of from about 0° C. to about 180° C., a room temperature vulcanizable material selected from (i) a mixture comprising: (A) 100 parts of a silanol terminated polydiorganosiloxane; (B) a stabilizing amount of a silicon-nitrogen compound for scavenging hydroxy radicals, said silicon-nitrogen compound releasing ammonia as a by-product of the hydroxy-scavenging reaction; (C) 0 to 10 parts of a crosslinking silane of the formula ##STR19## (D) an effective amount of a condensation catalyst; and (E) an effective amount of a scavenger for said ammonia by-product of the hydroxy-scavenging reaction selected from the group consisting of molecular sieves and acids and mixtures thereof; and (ii) a mixture comprising (A) 100 parts of a polyalkoxy-terminated polydiorganosiloxane base polymer; (B) 0 to 10 parts of a crosslinking silane of the formula ##STR20## (C) an effective amount of a condensation catalyst; (D) a stabilizing amount of a silicon-nitrogen compound for scavenging hydroxy radicals, said silicon-nitrogen compound releasing ammonia as a by-product of the hydroxy-scavenging reaction; and (E) an effective amount of a scavenger for said ammonia by-product of the hydroxy-scavenging reaction selected from the group consisting of molecular sieves and acids and mixtures thereof; where R 1 is a C 1-8 aliphatic organic radical selected from the group consisting of alkyl, alkylether, alkylester, alkylketone, and alkylcyano or a C 7-13 monovalent substituted or unsubstituted hydrocarbon radial, R 2 is a C 1-13 monovalent substituted or unsubstituted hydrocarbon radical, and e equals 0 or 1.