Back to results
US 5,175,057 AGranted
Adhesion promoters for room temperature vulcanizable silicone compositions
AssigneeGeneral Electric Company
InventorsJeffrey H. Wengrovius, Gary M. Lucas
Life of this patent
Estimating the term…
Abstract
Alkoxy-functional RTV silicone compositions are provided containing improved adhesion promoters which are the reaction product of a silanol-containing polysiloxane fluid preferably comprising (i) monoorganosiloxy; (ii) triorganosiloxy units; (iii) diorganosiloxy units; and, optionally, (iv) siloxy units; and B) an organofunctional-polyalkoxysilane containing polar organic groups.
Claims17
An alkoxy-functional RTV organopolysiloxane composition comprising by weight:
- (1) 100 parts of a polyalkoxy-terminated 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 chain end is terminated with at least two alkoxy radicals, the organic group being a C.sub.1-15 monovalent hydrocarbon radical;
- (2) an effective amount of a diorganotin bis beta-diketonate condensation catalyst of the general formula:
- ##STR6## wherein R.sup.4 is selected from C.sub.(1-18) monovalent hydrocarbon radicals and substituted monovalent hydrocarbon radicals, and R.sup.5, R.sup.6, and R.sup.7 are the same or different monovalent radicals selected from the class consisting of hydrogen, R.sup.4, OR.sup.4, --Si(R.sup.4).sub.3, --OSi(R.sup.4).sub.3, aryl, acyl, and nitrile;
- and
- (3) from about 1.0 to about 50 parts of an adhesion promoter which is the product prepared by reacting at a temperature in the range of from about 10.degree. to about 150.degree. C.:
- (A) 100 parts by weight of a silanol-containing polysiloxane selected from
- (i) a linear, silanol-terminated polydiorganosiloxane having the general formula:
- HO(R.sub.2 SiO).sub.n H
- wherein each R is independently a monovalent hydrocarbon radical having from 1 to about 10 carbon atoms, and "n" is a whole number that varies from about 2 to about 1000;
- or
- (ii) a silanol-containing polysiloxane fluid comprising:
- (a) from about 1 to about 80 mole percent of monoorganosiloxy units;
- (b) from about 0.5 to about 50 mole percent of triorganosiloxy units;
- (c) from about 1 to about 80 mole percent of diorganosiloxy units;
- and
- (d) from 0 to about 25 mole percent of siloxy units;
- the silanol-containing polysiloxane containing from about 0.01 to about 7% by weight of silicon-bonded hydroxyl groups;
- and
- (B) from about 0.1 to about 10 parts by weight of at least one organofunctional-polyalkoxysilane having the general formula ##STR7## wherein each R.sup.1 and R.sup.3 is independently a monovalent hydrocarbon radical having from 1 to about 20 carbon atoms;
- each R.sup.2 is independently a divalent saturated, unsaturated, or aromatic hydrocarbon radical having from 1 to about 20 carbon atoms;
- X is a polar organic radical selected from the group consisting of amido, formamido, imidato, ureas, isocyanato, cyano, acryloxy, acyloxy, ether, and epoxy, and "a" is a number from 0 to 2.
18 more elements
A method for improving the adhesion of an RTV composition to a substrate, comprising the step of combining
- (a) an alkoxy-functional RTV organopolysiloxane composition comprising by weight:
- (1) 100 parts of a polyalkoxy-terminated 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 chain end is termined with at least two alkoxy radicals, the organic group being a C.sub.1-15 monovalent hydrocarbon radical;
- and
- (2) an effective amount of a diorganotin bis beta-diketonate condensation catalyst of the general formula:
- ##STR9## wherein R.sup.4 is selected from C.sub.(1-18) monovalent hydrocarbon radicals and substituted monovalent hydrocarbon radicals, and R.sup.5, R.sup.6, and R.sup.7 are the same or different monovalent radicals selected from the class consisting of hydrogen, R.sup.4, OR.sup.4, --Si(R.sup.4).sub.3, --OSi(R.sup.4).sub.3, aryl, acyl, and nitrile;
- with
- (b) from about 1 to about 50 parts of an adhesion promoter which is the product prepared by reacting at a temperature in the range of from about 10.degree. to about 150.degree. C.:
- (A) 100 parts by weight of a silanol-containing polysiloxane selected from
- (i) a linear, silanol-terminated polydiorganosiloxane having the general formula:
- HO(R.sub.2 SiO).sub.n H
- wherein each R is independently a monovalent hydrocarbon radical having from 1 to about 20 carbon atoms, and "n" is a whole number that varies from about 2 to about 1000;
- or
- (ii) a silanol-containing polysiloxane fluid comprising:
- (a) from about 1 to about 80 mole percent of monoorganosiloxy units;
- (b) from about 0.5 to about 50 mole percent of triorganosiloxy units;
- (c) from about 1 to about 80 mole percent of diorganosiloxy units;
- and
- (d) from 0 to about 25 mole percent of siloxy units;
- the silanol-containing polysiloxane containing from about 0.01% to about 7% by weight of silicon-bonded hydroxyl groups;
- and
- (B) from about 0.1 to about 10 parts by weight of at least one organofunctional-polyalkoxysilane having the general formula ##STR10## wherein each R.sup.1 and R.sup.3 is independently a monovalent hydrocarbon radical having from 1 to about 20 carbon atoms;
- each R.sup.2 is independently a divalent saturated, unsaturated, or aromatic hydrocarbon radical having from 1 to about 20 carbon atoms;
- X is a polar organic radical selected from the group consisting of amido, formamido, imidato, ureas, isocyanato, cyano, acryloxy, acyloxy, ether, and epoxy, and "a" is a number from 0 to 2.
20 more elements
Dependencies are inferred from the claim text.