Process for making siloxane oligomer
A process for making a Si—H functional siloxane oligomer from the reaction between silicon hydride compositions and cyclic siloxane oligomer in the presence of a Lewis acid is provided. The Lewis acid is operable to interact with the hydrogen of the silicon hydride to promote ring opening of the cyclic siloxane oligomer and the insertion a siloxane oligomer segment between Si and H atom to thereby form the Si—H functional siloxane oligomer.
1 . A process for making a Si—H functional siloxane oligomer, comprising:
reacting at least one of a silicon hydride or a Si—H functional siloxane with both a cyclic siloxane oligomer and a Lewis acid, wherein a pendant hydrogen of the silicon hydride or of the Si—H functional siloxane promotes ring opening of the cyclic siloxane oligomer to form a polysiloxane segment, and the polysiloxane segment inserts between the hydrogen and the silicon atom from which the hydrogen was pendant.
2 . The process as defined in claim 1 wherein said cyclic siloxane oligomer has the formula
wherein R 1 and R 2 may be independently selected from hydrogen, a group of one to twelve carbon atom monovalent hydrocarbon radicals, a group of one to about twelve carbon atom monovalent hydrocarbon radicals substituted with one or more halogens, and combinations of two or more thereof.
3 . The process as defined in claim 1 wherein the Lewis acid catalyst comprises a composition of the formula:
MR 3 b X c
wherein M is selected from the group consisting of B, Al, Ga, In and Tl; each R 3 is independently selected from the group of monovalent aromatic hydrocarbon radicals having from 6 to 14 carbon atoms; X is a halogen atom selected from the group consisting of F, Cl, Br, and I; b is 1, 2, or 3; and c is 0, 1 or 2; subject to the requirement that b+c=3.
4 . The process as defined in claim 3 wherein each R 3 is C 6 F 5 and b=3.
5 . The process as defined in claim 3 where M is boron.
6 . The process as defined in claim 1 wherein the Lewis acid catalyst is tri(pentafluorophenyl)boron.
7 . The process as defined in claim 1 wherein the Lewis acid is present in a concentration in a range of from about 10 wppm to about 50,000 wppm.
8 . The process as defined in claim 1 wherein said cyclic siloxane oligomer comprises one or more cyclic trisiloxane oligomers.
9 . The process as defined in claim 1 wherein said cyclic siloxane oligomer is selected from the group consisting of hexamethyl cyclo trisiloxane, triphenyl trimethyl cyclo trisiloxane, trimethyl tris (trifluoro propyl)cyclo trisiloxane, and hexaphenyl cyclo trisiloxane.
10 . The process as defined in claim 1 wherein said polysiloxane segment is a trisiloxane segment.
11 . The process as defined in claim 1 wherein the Si—H functional siloxane comprises one or more alkyl polysiloxane, aryl polysiloxane, or alkylaryl polysiloxane.
12 . The process as defined in claim 1 further comprising providing thermal energy.
13 . The process as defined in claim 1 wherein one or both of the silicon hydride or the Si—H functional siloxane comprises one or more trialkylsilane, dialkylarylsilane, alkyldiarylsilane, triarylsilane, dialkylsilane, alkylarylsilane, diarylsilane, alkylsilane, or arylsilane.
14 . A Si—H functional siloxane oligomer prepared by the process as defined in claim 1 .
15 . A process, comprising:
interacting one or both of a silicon hydride or of a Si—H functional siloxane with a Lewis acid, the Lewis acid being operable to interact with a hydrogen that is pendant from a silicon atom of at least one of the silicon hydride or of the Si—H functional siloxane;
opening a ring of a cyclic siloxane oligomer using the interacted hydrogen to form a polysiloxane segment;
inserting the polysiloxane segment between the interacted hydrogen and the silicon atom to form a telomer; and
reacting the telomer with at least another cyclic siloxane oligomer.
16 . The process as defined in claim 15 wherein said cyclic siloxane oligomer has the formula
wherein R 1 and R 2 may be independently selected from hydrogen, a group of one to twelve carbon atom monovalent hydrocarbon radicals, a group of one to twelve carbon atom monovalent hydrocarbon radicals substituted with one or more halogens, and combinations thereof.
17 . The process as defined in claim 15 wherein the Lewis acid catalyst comprises a composition of the formula:
MR 3 b X c
wherein M is selected from the group consisting of B, Al, Ga, In and TI; each R 3 is independently selected from the group of monovalent aromatic hydrocarbon radicals having from 6 to 14 carbon atoms; X is a halogen atom selected from the group consisting of F, Cl, Br, and I; b is 1, 2, or 3; and c is 0, 1 or 2; subject to the requirement that b+c=3.
18 . The process as defined in claim 16 where M is boron.
19 . The process claim 16 wherein each R 3 is C 6 F 5 and b=3.
20 . The process as defined in claim 15 wherein the Lewis acid catalyst is tri(pentafluorophenyl)boron.
21 . The process as defined in claim 15 wherein the concentration of the Lewis acid catalyst ranges from about 10 wppm to about 50,000 wppm.
22 . The process as defined in claim 15 wherein said cyclic siloxane oligomer comprises a cyclic trisiloxane oligomer.
23 . The process as defined in claim 15 wherein said cyclic siloxane oligomer is selected from the group consisting of hexamethyl cyclo trisiloxane, triphenyl trimethyl cyclo trisiloxane, and trimethyl tris (trifluoropropyl)cyclo trisiloxane.
24 . The process as defined in claim 15 wherein said polysiloxane segment is a trisiloxane segment.
25 . The process as defined in claim 15 wherein one or both of the silicon hydride or the Si—H functional siloxane comprises one or more trialkylsilane, dialkylarylsilane, alkyldiarylsilane, triarylsilane, dialkylsilane, alkylarylsilane, diarylsilane, alkylsilane, or arylsilane.
26 . The process as defined in claim 15 further comprising providing thermal energy.
27 . Any one of an intermediate for a siloxane elastomers, a siloxane elastomers, an intermediate for an insulating material, an insulating material, an intermediate for a cosmetic product, a cosmetic product, siloxane foam, a siloxane coating, a hyperbranched silicone polymer, across-linked siloxane network, and a gel prepared by using the Si—H functional siloxane oligomer prepared by the process as defined in claim 1 .
28 . Any one of an intermediate for a siloxane elastomers, a siloxane elastomers, an intermediate for an insulating material, an insulating material, an intermediate for a cosmetic product, a cosmetic product, a siloxane foam, a siloxane coating, a hyperbranched silicone polymer, across-linked siloxane network, and a gel prepared by using the Si—H functional siloxane oligomer prepared by the process as defined in claim 15 .
29 . A siloxane oligomer comprising the reaction product of:
a silicon hydride or a Si—H functional siloxane, wherein the silicon hydride and the Si—H functional siloxane have a hydrogen that is pendant from a silicon atom;
a cyclic siloxane oligomer; and
a Lewis acid that is operable to interact with the pendant hydrogen, wherein the interaction enables the hydrogen to promote a ring opening of the cyclic siloxane oligomer to form a polysiloxane segment that is insertable between the pendant hydrogen and the silicon atom.