Claims
- 1. 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).
- 2. A room temperature vulcanizable silicone composition according to claim 1 wherein the polyalkoxy-terminated polydiorganosiloxane (A) has the general formula: ##STR17## wherein each R and R.sup.2 is independently a substituted or unsubstituted C.sub.(1-15) monovalent hydrocarbon radical, 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.(7-13) aralkyl radical; "n" is a whole number ranging from about 50 to about 2500, and "a" is a whole number which is either 0 or 1.
- 3. A composition according to claim 2 wherein R is selected from C.sub.(1-13) monovalent hydrocarbon radicals, halogenated hydrocarbon radicals, or cyano alkyl radicals; R.sup.1 is a C.sub.(1-8) alkyl radical or a C.sub.(7-13) aralkyl radical; and R.sup.2 is a methyl, phenyl, or vinyl radical.
- 4. A composition according to claim 3 wherein R, R.sup.1, and R.sup.2 are each methyl groups.
- 5. A composition according to claim 1 wherein the tin condensation catalyst is selected from the group consisting of di(n-butyl)tinbis(acetylacetonate), di(n-butyl)tinbis(benzoylacetonate), di(ethyl)tinbis(lauroylacetonate); di(methyl)tinbis(pivaloylacetonate); di(n-octyl)tinbis(acetylacetonate); di(n-propyl)tinbis(1,1,1 -trifluoroacetylacetonate); di(n-butyl)tin(acetylacetonate)(ethylacetoacetate) and di(n-butyl)tinbis(ethylacetoacetate).
- 6. A composition according to claim 5 wherein the catalyst is di(n-butyl)tinbis(acetylacetonate).
- 7. A composition according to claim 1 wherein the adhesion promoting polyalkoxysilane is an epoxy-functional polyalkoxysilane having the general formula: ##STR18## wherein R.sup.9, R.sup.10, R.sup.11, R.sup.12, R.sup.13 and b are as previously defined.
- 8. A composition according to claim 7 wherein the adhesion promoting epoxy-functional polyalkoxysilane is selected from the group consisting of gamma-glycidoxypropylmethyldimethoxysilane, gamma-glycidoxpropylmethyldiethoxysilane, gamma-glycidoxypropyltriethoxysilane, gamma-glycidoxypropylmethyldiethoxysilane, and gamma-glycidoxyethyltrimethoxysilane, and epoxycyclohexylethyltrimethoxysilane.
- 9. A composition according to claim 8 wherein the adhesion promoting epoxy-functional polyalkoxysilane is gamma-glycidoxypropyltrimethoxysilane.
- 10. A composition according to claim 1 wherein the crosslinking polyalkoxy silane is selected from the group consisting of methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, tetraethoxysilane, and vinyltrimethoxysilane.
- 11. A composition according to claim 10 wherein the crosslinking polyalkoxy silane is methyltrimethoxysilane.
- 12. A composition according to claim 11 further comprising filler.
- 13. A composition according to claim 12 wherein the filler is a reinforcing filler.
- 14. A composition according to claim 13 wherein the filler is fumed silica.
- 15. A composition according to claim 11 wherein the adhesion promoting polyalkoxysilane (D) is present in an amount ranging from about 0.8 to about 1.6 parts.
- 16. A composition according to claim 15 wherein the adhesion promoting polyalkoxysilane is present in an amount ranging from about 1.0 to about 1.6 parts.
- 17. A composition according to claim 11 wherein the condensation catalyst is present in an amount ranging from about 0.01 to about 2.0 parts.
- 18. A composition according to claim 17 wherein the condensation catalyst is present in the composition in an amount ranging from about 0.1 to about 1.0 parts.
- 19. A composition according to claim 1 wherein the scavenger is present in the composition in an amount ranging from about 0.2 to about 1 part.
- 20. A composition according to claim 19 wherein the scavenger is present in the composition in an amount ranging from about 0.4 to about 0.8 part.
- 21. A composition according to claim 1 wherein the crosslinking polyalkoxysilane is present in an amount ranging from about 0.3 to about 2.0 parts.
- 22. A composition according to claim 21 wherein the polyalkoxy crosslinking agent is present in an amount ranging from about 0.5 to about 1.6 parts.
- 23. 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., having the general formula: ##STR19## wherein R, R.sup.1 and R.sup.2 are each methyl radicals; "n" is a whole number ranging from about 50 to about 2500, and "a" is a whole number which is either 0 or 1;
- B. from about 0.2 to about 0.5 parts of di(n-butyl)tinbis(acetylacetonate);
- C. from about 0.4 to about 0.8 parts of hexamethyldisilazane;
- D. from about 0.8 to about 1.6 parts of gamma-glycidoxypropyltrimethoxysilane; and
- E. from 0.5 to about 1.6 parts of methyltrimethoxysilane.
- 24. The cured composition of claim 1.
- 25. The cured composition of claim 23.
- 26. A substrate coated with the composition of claim 1.
- 27. A substrate according to claim 26 wherein the substrate is a masonry substrate, aluminum, glass, polyacrylate, polycarbonate, polyvinylchloride, or concrete substrate.
- 28. A substrate coated with the composition of claim 23.
- 29. A substrate according to claim 28 wherein the substrate is a masonry substrate, aluminum, glass, polyacrylate, polycarbonate, polyvinylchloride, or concrete substrate.
- 30. A substrate coated with the cured composition of claim 1.
- 31. A substrate according to claim 30 wherein the substrate is a masonry substrate, aluminum, glass, polyacrylate, polycarbonate, polyvinylchloride, or concrete substrate.
- 32. A substrate coated with the cured composition of claim 23.
- 33. A substrate according to claim 32 wherein the substrate is a masonry substrate, aluminum, glass, polyacrylate, polycarbonate, polyvinylchloride, or concrete substrate.
Parent Case Info
This is a continuation of Ser. No. 08/046,511 filed on Apr. 12, 1993 now abandoned which is a contuation of Ser. No. 07/628,771 filed on Dec. 17, 1990 also abandoned.
US Referenced Citations (13)
Continuations (2)
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Number |
Date |
Country |
Parent |
46511 |
Apr 1993 |
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Parent |
628771 |
Dec 1990 |
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