Room temperature vulcanizable silicone compositions

A scavenger-containing room temperature vulcanizable silicone composition having improved shelf life, primerless adhesion, deep section cure, and low toxicity properties, comprising by weight:

• A. 100 parts of a polydiorganosiloxane having a viscosity of from about 100 to about 1,000,000 centipoise at 25.degree. C., wherein the silicon atoms at each polymer end chain is terminated with at least two R'O groups, the organic group being a C.sub.1-15 monovalent organic radical, wherein R' is as defined below;
• B. an effective amount of a diorganotin bis beta-diketonate condensation catalyst of the general formula:
• ##STR13## wherein R.sup.5 is selected from C.sub.(1-18) monovalent hydrocarbon radicals or substituted monovalent hydrocarbon radicals, and R.sup.6, R.sup.7, and R.sup.8 are the same or different monovalent radicals selected from the class consisting of hydrogen, R.sup.5, OR.sup.5, --OSi(R.sup.5).sub.3, --Si(R.sup.5).sub.3, aryl, acyl, and nitrile;
• C. from about 0.1 to about 1.5 parts of a scavenger for hydroxy functional groups;
• D. from about 0.6 to about 5 parts of an adhesion promoting polyalkoxysilane having the general formula:
• ##STR14## wherein R.sup.9 and R.sup.10 are C.sub.1-8 monovalent hydrocarbon radicals;
• Z is a saturated, unsaturated or aromatic hydrocarbon residue which is further functionalized by a member selected from the class consisting of ether, isocyanato, cyano, acryloxy, and acyloxy and a group having the general formula:
• ##STR15## wherein R.sup.11 and R.sup.12 are C.sub.2-12 divalent hydrocarbon radicals, R.sup.13 is selected from the group consisting of hydrogen and C.sub.1-8 monovalent hydrocarbon radicals;
• and b varies from 0 to 1;
• and
• E. from 0 to about 10 parts of a crosslinking silane having the general formula:
• ##STR16## wherein R.sup.1 is a C.sub.(1-8) aliphatic organic radical selected from alkyl radicals, alkylether radicals, alkylester radicals, alkylketone radicals, alkylcyano radicals, or a C.sub.(7-15) aralkyl radical;
• each R.sup.2 is independently a substituted or unsubstituted C.sub.(1-15) monovalent hydrocarbon radical;
• and b is the same as in D wherein component (E) is different from component (D).