Claims
- 1. A one-package substantially anhydrous room temperature vulcanizable organopolysiloxane composition convertible to a tack-free elastomer, comprising: (1) an organopolysiloxane wherein the silicon atom at each polymer chain end is terminated with at least 1 hydroxy radical; (2) an effective amount of cross-linking agent; and (3) an effective amount of end-capping catalyst comprising a combination of (i) a Lewis acid and (ii) a compound selected from the group consisting of substituted guanidines, amines and mixtures thereof.
- 2. The composition of claim 1 wherein the cross-linking agent has the formula ##STR39## where R.sup.1 is a C.sub.(1-8) aliphatic organic radical selected from the group consisting of alkyl, alkylester, alkylketone and alkylcyano radicals of a C.sub.(7-13) arakyl radical, R.sub.2 is a C.sub.(1-13) monovalent substituted or unsubstituted hydrocarbon radical and b is a whole number equal to 0 or 1.
- 3. The composition of claim 1 wherein ingredient (3)(i) of the end-capping catalyst is an acid anhydride.
- 4. The composition of claim 1 wherein ingredient (3)(i) of the end-capping catalyst has the formula ##STR40## where R.sup.30 and R.sup.31 are C.sub.(1-20) monovalent hydrocarbon radicals and j is a whole number that varies from 0 to 3.
- 5. The composition of claim 1 wherein ingredient (3) (i) of the end-capping catalyst has the formula ##STR41## where R.sup.32 is a C.sub.(1-20) monovalent hydrocarbon radical.
- 6. The composition of claim 1 wherein ingredient (3) (i) of the end-capping catalyst is an inorganic acid.
- 7. The composition of claim 6 wherein the inorganic acid is selected from the class consisting of HCl, H.sub.3 PO.sub.4, H.sub.2 SO.sub.4, and polyphosphoric acid.
- 8. The composition of claim 3 wherein the acid anhydride has the formula ##STR42## where R.sup.33, R.sup.34 are C.sub.(1-20) monovalent hydrocarbon radicals.
- 9. The composition of claim 1 wherein ingredient (3) (i) of the end-capping catalyst is selected from the group consisting of
- BF.sub.3, (CH.sub.3 CH.sub.2).sub.2 O, and AlCl.sub.3.
- 10. The composition of claim 1 wherein the total acid number does not exceed 15.
- 11. The composition of claim 1 wherein the acid number is at least 0.1.
- 12. The composition of claim 1 wherein ingredient (3) (i) is present at a concentration of 0.1 to 0.5 parts by weight per 100 parts by weight of the organopolysiloxane and ingredient (3) (ii) is present at a concentration of 0.1 to 0.5 parts by weight per 100 parts by weight of the organopolysiloxane.
- 13. 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: (1) an organopolysiloxane wherein the silicon atom at each polymer chain end is terminated with at least 1 hydroxy radical: (2) an effective amount of a polyalkoxy cross-linking agent; (3) an effective amount of end-capping catalyst comprising a combination of (i) a Lewis acid and (ii) a compound selected from the group consisting of substituted guanidines, amines and mixtures thereof; (4) a stabilizing amount of silane scavenger for hydroxy functional groups having the formula ##STR43## wherein R.sup.1 is a C.sub.(1-8) aliphatic organic radical selected from the group consisting of alkyl, alkylether, alkylester, alkylketone, and alkylcyano radicals, or a C.sub.(7-13) aralkyl radicl, R.sup.2 is a C.sub.(1-13) monovalent substituted or unsubstituted hydrocarbon radical, X is a hydrolyzable leaving group selected from the group consisting of amido, amino, carbamato, enoxy, imidato, isocyanato, oximato, thioisocyanato, and ureido radicals and, c is a whole number equal to 0 to 3 inclusive, f is an integer equal to 1 to 4 inclusive and the sum of c+f is equal to 1 to 4 inclusive; and (5) an effective amount of a condensation catalyst.
- 14. The composition of claim 13 wherein the cross-linking agent has the formula ##STR44## where R.sup.1 is a C.sub.(1-8) aliphatic organic radical selected from the group consisting of alkyl, alkylester, alkylketone and alkylcyano radicals or a C.sub.(7-13) arakyl radical, R.sup.2 is a C.sub.(1-13) monovalent substituted or unsubstituted hydrocarbon radical and b is a whole number equal to 0 or 1.
- 15. The composition of claim 13 wherein ingredient (3) (i) of the end-capping catalyst is an acid anhydride.
- 16. The composition of claim 13 wherein ingredient (3) (i) of the end-capping catalyst has the formula ##STR45## where R.sup.30 and R.sup.31 are C.sub.(1-20) monovalent hydrocarbon radicals and j is a whole number that varies from 0 to 3.
- 17. The composition of claim 13 wherein ingredient (3) (i) of the end-capping catalyst has the formula ##STR46## where R.sup.32 is a C.sub.(1-20) monovalent hydrocarbon radical.
- 18. The composition of claim 13 wherein ingredient (3) (i) of the end-capping catalyst is an inorganic acid.
- 19. The composition of claim 18 wherein the inorganic acid is selected from the class consisting of HCl, H.sub.3 PO.sub.4, H.sub.2 SO.sub.4, and polyphosphoric acid.
- 20. The composition of claim 15 wherein the acid anhydride has the formula ##STR47## where R.sup.33, R.sup.34 are C.sub.(1-20) monovalent hydrocarbon radicals.
- 21. The composition of claim 13 wherein ingredient (3) (i) of the end-capping catalyst is selected from the group consisting of BF.sub.3, (CH.sub.3 CH.sub.2).sub.2 O, and AlCl.sub.3.
- 22. The composition of claim 13 wherein the total acid number does not exceed 15.
- 23. The composition of claim 13 wherein the total acid number is at least 0.1.
- 24. The composition of claim 13 wherein ingredient (3) (i) is present at a concentration of 0.1 to 0.5 parts by weight per 100 parts by weight of the organopolysiloxane and ingredient (3) (ii) is present at a concentration of 0.1 to 0.5 parts by weight per 100 parts by weight of the organopolysiloxane.
- 25. The composition of claim 13 wherein the scavenging silane has the formula ##STR48## where R.sup.1 is a C.sub.(1-8) aliphatic organic radical selected from the group consisting of alkyl, alkylether, alkylester, alkylketone and alkylcyano radicals, or a C.sub.(7-13) aralkyl radical, R.sup.2 is a C.sub.(1-13) monovalent substituted or unsubstituted hydrocarbon radical, X is a hydrolyzable leaving group selected from the group consisting of amido, amino, carbamato, enoxy, imidato, isocyanato, oximato, thioisocyanato and ureido radicals; and, a is an integer equal to 1 or 2 inclusive, b is a whole number equal to 0 to 1 inclusive and silane is both the silane scavenger for hydroxy functional groups and a polyalkoxysilane cross-linking agent for terminating the silicon atom at each organopolysiloxane chain end with at least two alkoxy radicals.
- 26. A room temperature vulcanizable composition in accordance with claim 13 where the silane scavenger is methyldimethoxy-N-methylacetamidosilane.
- 27. A room temperature vulcanizable composition in accordance with claim 13, which contains a tin compound as the condensation catalyst.
- 28. A room temperature vulcanizable composition in accordance with claim 13, where R, R.sup.1 and R.sup.2 are methyl and which has a tin compound as a condensation catalyst.
- 29. An RTV composition in accordance with claim 13 wherein the condensation catalyst is dibutyltindiacetate.
- 30. An RTV composition in accordance with claim 13 containing a polymethoxysilane cross-linking agent.
- 31. A one-package room temperature vulcanizable composition in accordance with claim 30, where the polymethoxysilane is methyltrimethoxysilane.
- 32. A one-package RTV in accordance with claim 13, where the substituted guanidine is butyltetramethylguanidine.
- 33. A one-package RTV in accordance with claim 13 wherein ingredient (3) (ii) is a dialkylamine.
- 34. A one-package, stable, room temperature vulcanizable composition in accordance with claim 13 having an excess of up to 3% by weight of silane scavenger based on the weight of the organopolysiloxane.
- 35. A room temperature vulcanizable composition in accordance with claim 13 wherein ingredient (3) (ii) is di-n-hexylamine.
- 36. 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 0.degree. C. to 180.degree. C., a room temperature vulcanizable material comprising a mixture of
- (a) 100 parts of a silanol-terminated polydiorganosiloxane consisting essentially of chemically combined units of the formula ##STR49## (b) 0 to 10 parts of cross-linking agent and (c) an effective amount of end-capping catalyst comprising a combination of (i) a Lewis acid and (ii) a compound selected from the group consisting of substituted guanidines, amines and mixtures thereof, where R is selected from C.sub.(1-13) monovalent substituted or unsubstituted hydrocarbon radicals.
- 37. A mixture comprising
- (a) 100 parts of a silanol-terminated polydiorganosiloxane consisting essentially of chemically combined units of the formula ##STR50## (b) a stabilizing amount of a silane scavenger for hydroxy functional groups of the formula ##STR51## (c) 0 to 10 parts of cross-linking silane of the formula ##STR52## (d) an effective amount of end-capping catalyst comprising a combination of (i) a Lewis acid and (ii) a compound selected from the group consisting of substituted guanidines, amines and mixtures thereof, and
- (e) an effective amount of condensation catalyst,
- where R is selected from C.sub.(1-13) monovalent substituted or unsubstituted hydrocarbon radicals, R.sup.1 is a C.sub.(1-8) aliphatic organic radical selected from the group consisting of alkyl, alkylether, alkylester, alkylketone and alkylcyano radicals or a C.sub.(7-13) aralkyl radical, R.sup.2 is a C.sub.(1-13) monovalent substituted or unsubstituted hydrocarbon radical, X is a hydrolyzable leaving group selected from the group consisting of amido, amino, carbamato, enoxy, imidato, isocyanato, oximato, thioisocyanato and ureido radicals, and a is an integer equal to 1 or 2, b is a whole number equal to 0 or 1, and the sum of a+b is equal to 1 or 2.
- 38. 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 polymer chain end is terminated with at least 1 hydroxy radical;
- (b) optionally, a polyalkoxysilane cross-linking agent;
- (c) an effective amount of end-capping catalyst comprising a combination of (i) a Lewis acid and (ii) a compound selected from the group consisting of substituted guanidines, amines and mixtures thereof;
- (d) an effective amount of a condensation catalyst; and
- (e) a stabilizing amount of a scavenger for hydroxy functional groups selected from the group consisting of non-cyclic silyl nitrogen compounds of the formula ##STR53## and cyclic silyl nitrogen compounds having at least one unit of the formula ##STR54## and the rest of the units, if any, having the formula ##STR55## where R.sup.10 and R.sup.12 are C.sub.1-8 aliphatic organic radicals selected from the group consisting of alkyl, alkylether, alkylester, alkylketone, alkylcyano and aryl, R.sup.11, R.sup.13 and R.sup.14 are C.sub.1-8 monovalent substituted or unsubstituted hydrocarbon radicals, a varies from 0 to 2, h is 0 or 1, s varies from 1 to 25, Q is selected from the group consisting of hydrogen, C.sub.1-8 monovalent substituted or unsubstituted hydrocarbon radicals and radicals of the formula ##STR56## where R.sup.10 is a C.sub.1-8 aliphatic organic radical selected from the group consisting of alkyl, alkylether, alkylester, alkylketone, alkylcyano and aryl, R.sup.11 is a C.sub.1-8 monovalent substituted or unsubstituted hydrocarbon radical, f varies from 0 to 3, d is a whole number that varies from 1 to 25, R.sup.22 is selected from the group consisting of hydrogen and C.sub.1-8 monovalent hydrocarbon radicals and R.sup.23 is selected from the group consisting of monovalent hydrocarbon radicals and hydrocarbonoxy radicals, A is selected from the group consisting of hydrogen, C.sub.1-8 monovalent substituted and unsubstituted hydrocarbon radicals and radicals of the formula ##STR57## where R.sup.10 is a C.sub.1-8 aliphatic organic radical selected from the group consisting of alkyl, alkylether, alkylester, alkylketone, alkylcyano and aryl, R.sup.11 is a C.sub.1-8 monovalent substituted or unsubstituted hydrocarbon radical, g varies from 0 to 3, and in the above scavenger there is at least one hydrocarbonoxy group in the molecule.
- 39. A room temperature vulcanizable composition in accordance with claim 38, having an effective amount of a cross-linking silane of the formula ##STR58## where R.sup.1 is a C.sub.1-8 aliphatic organic radical selected from the group consisting of alkyl, alkylether, alkylester, alkylketone and alkylcyano radicals, or a C.sub.7-13 aralkyl radical, R.sup.2 is a C.sub.1-13 monovalent substituted or unsubstituted hydrocarbon radical, and b is a whole number equal to 0 or 1.
- 40. 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 0.degree. C. to 180.degree. C., a room temperature vulcanizing material comprising a mixture of:
- (i) 100 parts of a silanol-terminated polysiloxane consisting essentially of chemically combined units of the formula ##STR59## (ii) a stabilizing amount of a scavenger for hydroxy functional groups selected from the group consisting of non-cyclic silyl nitrogen compounds of the formula ##STR60## and cyclic silyl nitrogen compounds having at least one unit of the formula ##STR61## and the rest of the units, if any, having the formula ##STR62## where R is a C.sub.1-13 monovalent substituted or unsubstituted hydrocarbon radical, R.sup.10 and R.sup.12 are C.sub.1-8 aliphatic organic radicals selected from the group consisting of alkyl, alkylether, alkylester, alkylketone, alkylcyano and aryl, R.sup.11, R.sup.13 and R.sup.14 are C.sub.1-8 monovalent substituted or unsubstituted hydrocarbon radicals, a varies from 0 to 2, h is 0 or 1, s varies from 1 to 25, Q is selected from the group consisting of hydrogen, C.sub.1-8 hydrocarbon radicals, and radicals of the formula ##STR63## where d is a whole number that varies from 1 to 25 and f varies from 0 to 3, R.sup.22 is selected from the group consisting of hydrogen and C.sub.1-8 monovalent hydrocarbon radicals and R.sup.23 is independently selected from C.sub.1-8 monovalent hydrocarbon radicals and hydrocarbonoxy radicals, A is selected from the group consisting of hydrogen, C.sub.1-8 monovalent substituted and unsubstituted hydrocarbon radicals and radicals of the formula ##STR64## where R.sup.10 is a C.sub.1-8 aliphatic organic radical selected from the group consisting of alkyl, alkylether, alkylester, alkylketone, alkylcyano and aryl, R.sup.11 is a C.sub.1-8 monovalent substituted or unsubstituted hydrocarbon radical, g varies from 0 to 3, and in the above scavengers there is at least one hydrocarbonoxy group in the molecule,
- (iii) 0-10 parts of polyalkoxy cross-linking silane,
- (iv) an effective amount of end-capping catalyst comprising a combination of (a) a Lewis acid and (b) a compound selected from the group consisting of substituted guanidines, amines and mixtures thereof; and
- (v) an effective amount of condensation catalyst.
- 41. A mixture comprising:
- (a) 100 parts of a silanol terminated polydiorganosiloxane consisting essentially of chemically combined units of the formula ##STR65## (b) a stabilizing amount of scavenger for hydroxy functional groups selected from the group consisting of non-cyclic silyl nitrogen compounds of the formula ##STR66## and cyclic silyl nitrogen compounds having at least one unit of the formula ##STR67## and the rest of the units, if any, having the formula ##STR68## where R is a C.sub.1-13 monovalent substituted or unsubstituted hydrocarbon radical, R.sup.10 and R.sup.12 are C.sub.1-8 aliphatic organic radicals selected from the group consisting of alkyl, alkylether, alkylester, alkylketone, alkylcyano and aryl, R.sup.11, R.sup.13 and R.sup.14 are C.sub.1-8 monovalent substituted or unsubstituted hydrocarbon radicals, a varies from 0 to 2, h is 0 or 1, s varies from 1 to 25, Q is selected from the group consisting of hydrogen, C.sub.1-8 monovalent substituted or unsubstituted hydrocarbon radicals and radicals of the formula ##STR69## where R.sup.10 is a C.sub.1-8 aliphatic organic radical selected from the group consisting of alkyl, alkylether, alkylester, alkylketone, alkylcyano and aryl, R.sup.11 is a C.sub.1-8 monovalent substituted or unsubstituted hydrocarbon radical, f varies from 0 to 3, d is a whole number that varies from 1 to 25, R.sup.22 is selected from the group consisting of hydrogen and C.sub.1-8 monovalent hydrocarbon radicals and R.sup.23 is independently selected from C.sub.1-8 monovalent hydrocarbon radicals and hydrocarbonoxy radicals, A is selected from the group consisting of hydrogen, C.sub.1-8 monovalent substituted or unsubstituted hydrocarbon radicals and radicals of the formula ##STR70## where R.sup.10 is a C.sub.1-8 aliphatic organic radical selected from the group consisting of alkyl, alkylether, alkylester, alkylketone, alkylcyano and aryl, R.sup.11 is a C.sub.1-8 monovalent substituted or unsubstituted hydrocarbon radical, and g varies from 0 to 3, wherein in the above scavenger there is at least one hydrocarbonoxy group in the molecule,
- (c) 0 to 10 parts of polyalkoxy cross-linking silane;
- (d) an effective amount of end-capping catalyst comprising a combination of (i) a Lewis acid and (ii) a compound selected from the group consisting of substituted guanidines, amines and mixtures thereof; and
- (e) an effective amount of condensation catalyst.
- 42. The mixture of claim 41, wherein the scavenger and cross-linking agent has the formula ##STR71##
- 43. The composition of claim 41 wherein ingredient (d) (i) of the end-capping catalyst is an acid anhydride.
- 44. The composition of claim 41 wherein ingredient (d) (i) of the end-capping catalyst has the formula ##STR72## where R.sup.30 and R.sup.31 are C.sub.(1-20) monovalent hydrocarbon radicals and j is a whole number that varies from 0 to 3.
- 45. The composition of claim 41 wherein ingredient (d) (i) of the end-capping catalyst has the formula ##STR73## where R.sup.32 is a C.sub.(1-20) monovalent hydrocarbon radical.
- 46. The composition of claim 41 wherein ingredient (d) (i) of the end-capping catalyst is an inorganic acid.
- 47. The composition of claim 46, wherein the inorganic acid is selected from the group consisting of HCl, H.sub.3 PO.sub.4, H.sub.2 SO.sub.4, and polyphosphoric acid.
- 48. The composition of claim 43 wherein the acid anhydride has the formula ##STR74## where R.sup.33, R.sup.34 are C.sub.(1-20) monovalent hydrocarbon radicals.
- 49. The composition of claim 41 wherein ingredient (d) (i) of the end-capping catalyst is selected from the group consisting of BF.sub.3, (CH.sub.3 CH.sub.2).sub.2 O, and AlCl.sub.3.
- 50. The composition of claim 41 wherein the total acid number does not exceed 15.
- 51. The composition of claim 41 wherein the total acid number is at least 0.1.
- 52. The composition of claim 41 wherein ingredient (d) (i) is present at a concentration of 0.1 to 0.5 parts by weight per 100 parts by weight of the organopolysiloxane and ingredient (d) (ii) is present at a concentration of 0.1 to 0.5 parts by weight per 100 parts by weight of the organopolysiloxane.
- 53. 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:
- (1) an organopolysiloxane wherein the silicon atom at each polymer chain end is terminated with at least 1 hydroxy radical;
- (2) a polyalkoxy cross-linking agent;
- (3) an effective amount of end-capping catalyst comprising a combination of (i) a Lewis acid and (ii) a compound selected from the group consisting of substituted guanidines, amines and mixtures thereof;
- (4) an effective amount of condensation catalyst; and
- (5) a stabilizing amount of a scavenger for hydroxy functional groups which is a silicon-nitrogen compound selected from the group consisting of:
- (A) silicon-nitrogen compounds having the formula ##STR75## where Y is selected from R"' and R".sub.2 N-- and (B) silicon-nitrogen polymers comprising (1) from 3 to 100 mole percent chemically combined structural units having the formula ##STR76## and (2) from 0 to 97 mole percent chemically combined structural units represented by the formula ##STR77## where the silicon atoms of said silicon-nitrogen polymer are joined to each other by a member selected from an SiOSi linkage and a SiNR"Si linkage, the free valences of said silicon atoms other than those joined to oxygen to form a siloxy unit and nitrogen to form a silazy unit are joined to a member selected from an R"' radical and an (R").sub.2 N radical and where the ratio of the sum of said R"' radicals and said (R").sub.2 N radicals to the silicon atoms of said silicon-nitrogen polymer has a value of 1.5 to 3, inclusive, and R" is a member selected from the group consisting of hydrogen, monovalent hydrocarbon radicals, and fluoroalkyl radicals, R"' is a member selected from the group consisting of hydrogen, monovalent hydrocarbon radicals and fluoroalkyl radicals, and c is a whole number equal to 0 to 3, inclusive.
- 54. 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 0.degree. C. to 180.degree. C., a room temperature vulcanizable material comprising a mixture of
- (A) 100 parts of a silanol-terminated polydiorganosiloxane consisting essentially of chemically combined units of the formula ##STR78## (B) from 1 to 10 parts of an alkoxy-functional cross-linking silane; (C) an effective amount of end-capping catalyst comprising a combination of (i) a Lewis acid and (ii) a compound selected from the group consisting of substituted guanidines, amines and mixtures thereof; and
- (D) a stabilizing amount of a scavenger for hydroxy functional groups selected from the group consisting of silicon-nitrogen compounds having the formula ##STR79## where Y is selected from R"' and R".sub.2 N and a silicon-nitrogen polymer comprising (1) from 3 to 100 mole percent chemically combined structural units having the formula ##STR80## and (2) from 0 to 97 mole percent chemically combined structural units represented by the formula ##STR81## where the silicon atoms of said silicon-nitrogen polymer are joined to each other by a member selected from an SiOSi linkage and a SiNR"Si linkage, the free valences of said silicon atoms other than those joined to oxygen to form a siloxy unit and nitrogen to form a silazy unit are joined to a member selected from an R"' radical and an (R").sub.2 N radical, and where the ratio of the sum of said R"' radicals and said (R").sub.2 N radicals to silicon atoms of said silicon-nitrogen polymer has a value of 1.5 to 3, inclusive, and R" is a member selected from the group consisting of hydrogen, monovalent hydrocarbon radicals and fluoroalkyl radicals, R"' is a member selected from the group consisting of hydrogen, monovalent hydrocarbon radicals and fluoroalkyl radicals, and c is a whole number equal to 0 to 3 inclusive, and
- (E) an effective amount of condensation catalyst.
- 55. A mixture comprising
- (A) 100 parts of a silanol-terminated polydiorganosiloxane consisting essentially of chemically combined units of the formula ##STR82## (B) 1 to 10 parts of a polyalkoxy cross-linking silane; (C) an effective amount of end-capping catalyst, comprising a combination of (i) a Lewis acid and (ii) a compound selected from the group consisting of substituted guanidines, amines and mixtures thereof;
- (D) a stabilizing amount of scavenger for hydroxy functional groups selected from the group consisting of silicon-nitrogen compounds having the formula ##STR83## where Y is selected from R"' and R".sub.2 N and silicon-nitrogen polymers comprising (1) from 3 to 100 mole percent chemically combined structural units having the formula ##STR84## and (2) from 0 to 97 mole percent chemically combined structural units represented by the formula ##STR85## where the silicon atoms of said silicon-nitrogen polymer are joined to each other by a member selected from an SiOSi linkage and a SiNR"Si linkage, the free valences of said silicon atoms other than those joined to oxygen to form a siloxy unit and nitrogen to form a silajy unit are joined to a member selected from an R"' radical and an (R").sub.2 N radical, and where the ratio of the sum of said R"' radicals and said (R").sub.2 N radicals to the silicon atoms of said silicon-nitrogen polymer has a value of 1.5 to 3, inclusive, and R" is a member selected from the group consisting of hydrogen, monovalent hydrocarbon radicals, anf fluoroalkyl radicals, R"' is a member selected from the group consisting of hydrogen, monovalent hydrocarbon radicals and fluoroalkyl radicals, and c is a whole number equal to 0 to 3, inclusive, and
- (E) an effective amount of condensation catalyst, where R is selected from C.sub.(1-13) monovalent substituted or unsubstituted hydrocarbon radicals.
- 56. The composition of claim 55 wherein ingredient (C) (i) of the end-capping catalyst is an acid anhydride.
- 57. The composition of claim 55 wherein ingredient (C) (i) of the end-capping catalyst has the formula ##STR86## where R.sup.30 and R.sup.31 are C.sub.(1-20) monovalent hydrocarbon radicals and j is a whole number that varies from 0 to 3.
- 58. The composition of claim 55 wherein ingredient (C) (i) of the end-capping catalyst has the formula ##STR87## where R.sup.32 is a C.sub.(1-20) monovalent hydrocarbon radical.
- 59. The composition of claim 55 wherein ingredient (C) (i) of the end-capping catalyst is an inorganic acid.
- 60. The composition of claim 59 wherein the inorganic acid is selected from the group consisting of HCl, H.sub.3 PO.sub.4, H.sub.2 SO.sub.4, and polyphosphoric acid.
- 61. The composition of claim 56 wherein the acid anhydride has the formula ##STR88## where R.sup.33, R.sup.34 are C.sub.(1-20) monovalent hydrocarbon radicals.
- 62. The composition of claim 55 wherein ingredient (C) (i) of the end-capping catalyst is selected from the group consisting of BF.sub.3, (CH.sub.3 CH.sub.2).sub.2 O, and AlCl.sub.3.
- 63. The composition of claim 55 wherein the total acid number does not exceed 15.
- 64. The composition of claim 55 wherein the total acid number is at least 0.1.
- 65. 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 (1) an organopolysiloxane wherein the silicon atom at each polymer chain end is terminated with at least one hydroxy radical; (2) a polyalkoxy cross-linking agent; (3) an effective amount of end-capping catalyst comprising a combination of (i) a Lewis acid and (ii) a compound selected from the group consisting of substituted guanidines, amines and mixtures thereof; and (4) a stabilizing amount of silane scavenger for hydroxy functional groups which is a silyl amine of the formula ##STR89## where R" is a radical selected from the group consisting of hydrogen and C.sub.(1-8) monovalent hydrocarbon radicals, R.sup.20 is a radical selected from the group consisting of C.sub.(1-8) monovalent hydrocarbon radicals and C.sub.(1-8) alkoxy radicals and fluoroalkyl radicals, and g is a whole number that varies from 1 to 3, h is a whole number that varies from 0 to 2 and the sum of h+g does not exceed 3.
Parent Case Info
This application is a continuation of application Ser. No. 427,930, filed Sept. 29, 1982, now abandoned.
US Referenced Citations (30)
Non-Patent Literature Citations (1)
Entry |
R. O. Sauer et al., J.A.C.S., vol. 68, 1946, pp. 241-244. |
Continuations (1)
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Number |
Date |
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Parent |
427930 |
Sep 1982 |
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