Thermally initiated acid catalyzed reaction between silyl hydride and siloxane
A composition contains a mixture of silyl hydride, a siloxane, a Lewis acid catalyst and an amine having the following formula: R 1 R 2 R 3 N; where the nitrogen is not a member of an N═C—N linkage and where each of R 1 , R 2 , and R 3 is independently selected from a group consisting of hydrogen, alkyl, substituted alkyl, and conjugated moieties; and wherein at least one of R 1 , R 2 and R 3 is a conjugated moiety connected to the nitrogen by a conjugated carbon.
1. A process comprising the steps of:
(a) providing a composition comprising a mixture of silyl hydride, a siloxane, tris(pentafluorophenyl)borane, and an amine selected from the group consisting of aniline and p-anisidine, provided the tris(pentafluorophenyl)borane and amine are combined so that the amine can complex with and block the catalytic activity of the Lewis acid prior to combining them with both of the silyl hydride and the siloxane, wherein the siloxane in the composition has a concentration of 70 weight % or more, and the silyl hydride in the composition has a concentration of 5 weight % or more each based on combined weight of silyl hydride, siloxane, amine, and tris(pentafluorophenyl)borane; and
(b) heating the composition to a temperature sufficient to dissociate the Lewis acid catalyst from the amine, wherein the temperature is 80° C. or higher.
2. The process of claim 1 , wherein the process further includes a step of applying the composition to a substrate or placing the composition in a mold after step (a) and before or during step (b).
3. The process of claim 2 , wherein the process further comprises forming a coating or a molded article from the composition.
4. The process of claim 1 , wherein in step (b) the temperature is 80° C. to 300° C.
5. The process of claim 1 , wherein the silyl hydride and the siloxane are the same molecule.
6. The process of claim 1 , wherein the composition is free of a UV light sensitive blocking agent for the tris(pentafluorophenyl)borane.
7. The process of claim 1 , wherein the siloxane is a polysiloxane comprising M, D, T, and Q units with a degree of polymerization of 10 to 10,000.
8. The process of claim 1 , wherein the silyl hydride is polymeric and contains more than one Si—H bond.
9. The process of claim 1 , wherein the siloxane or the silyl hydride, or both serves as a crosslinker.
10. The process of claim 1 , further comprising adding one or a combination of more than one component selected from the group consisting of hydrocarbyl solvents, pigments, fillers, moisture scavengers, fluorescent brighteners, stabilizers, and corrosion inhibitors.
11. The process of claim 4 , wherein in step (b) the temperature is 80° C. to 250° C.
12. The process of claim 11 , wherein in step (b) the temperature is 80° C. to 200° C.
13. The process of claim 12 , wherein in step (b) the temperature is 80° C. to 150° C.
14. The process of claim 1 , wherein in step (a), the tris(pentafluorophenyl)borane and the amine are combined by a process comprising mixing the tris(pentafluorophenyl)borane and the amine, wherein the amine is at a concentration of 100 mol % to 110 mol % relative to total moles of tris(pentafluorophenyl)borane.