Polyfunctional organosiloxanes, compositions containing same, and methods for the preparation thereof

Patent metadata

Field	Value
Publication number	US-11905375-B2
Application number	US-201917277636-A
Country	US
Kind code	B2
Filing date	Dec 4, 2019
Priority date	Dec 21, 2018
Publication date	Feb 20, 2024
Grant date	Feb 20, 2024

Abstract

A polyfunctional organohydrogensiloxane and method for its preparation using a boron containing Lewis acid as catalyst is disclosed. A clustered functional organosiloxane may be prepared by a method comprising functionalizing the polyfunctional organohydrogensiloxane. The polyfunctional organohydrogensiloxane and the clustered functional organosiloxane are useful in curable compositions. The polyfunctional organohydrogensiloxane may be used in a release coating composition. The clustered functional organosiloxane may be used in an adhesive composition.

First claim

The invention claimed is:

1. A clustered functional organosiloxane of unit formula:

where

subscript n is 2 to 2,000, each subscript d is independently 0 to 995, subscript o′=0 to 100, subscript n′=(o′+1), each R is an independently selected monovalent hydrocarbon group, each R 1 is independently selected from the group consisting of monovalent hydrocarbon groups and monovalent halogenated hydrocarbon groups, and each R 8 is a hydrogen atom or a curable group, with the proviso that at least one R 8 per molecule is a curable group other than hydrogen.

2. The clustered functional organosiloxane of claim 1 , where subscript o′=0 and the clustered functional organosiloxane has formula:

3. The clustered functional organosiloxane of claim 2 , where each subscript d=0, and the clustered functional organosiloxane has formula:

4. The clustered functional organosiloxane of claim 1 , where subscript n is 2 to 1,000, each R is an alkyl group of 1 to 6 carbon atoms, and each R 1 is selected from the group consisting of an alkyl group of 1 to 20 carbon atoms, an alkenyl group of 2 to 20 carbon atoms, an aryl group of 6 to 20 carbon atoms, and a halogenated alkyl group of 1 to 20 carbon atoms.

5. The clustered functional organosiloxane of claim 1 , where subscript n is 5 to 50; each R is methyl; and each R 1 is independently selected from the group consisting of methyl, vinyl, phenyl, and trifluoropropyl.

6. A method for preparing a polyfunctional organohydrogensiloxane comprising:
1) combining
A) a boron containing Lewis acid;
B) a hydroxyl terminated polydiorganosiloxane of formula

subscript n is 2 to 2,000, and each R 1 is independently selected from the group consisting of monovalent hydrocarbon groups and monovalent halogenated hydrocarbon groups; and
C) a polyorganohydrogensiloxane of formula

where each subscript d is independently 0 to 995, and each R is an independently selected monovalent hydrocarbon group, thereby preparing the product, where the product comprises a polyfunctional organohydrogensiloxane and a by-product comprising H 2 .

7. The method of claim 6 , where the method is performed at a temperature of 5° C. to 70° C.

8. The method of claim 6 , where A) the boron containing Lewis acid is a trivalent boron compound with at least one perfluoroaryl group per molecule.

9. The method of claim 8 , where A) the boron containing Lewis acid is B(C 6 F 5 ) 3 , tris(pentafluorophenyl)borane.

10. The method of claims 6 , where subscript n is 2 to 1,000, and each R 1 is selected from the group consisting of an alkyl group of 1 to 20 carbon atoms, an alkenyl group of 2 to 20 carbon atoms, an aryl group of 6 to 20 carbon atoms, and a halogenated alkyl group of 1 to 20 carbon atoms.

11. The method of claims 6 , where C) the polyorganohydrogensiloxane has formula:

12. The method of claim 11 , where each R is an alkyl group of 1 to 6 carbon atoms.

13. The method of claims 6 , further comprising recovering the polyfunctional organohydrogensiloxane, wherein the method comprises one or more of: 2) during and/or after step 1), removing the H 2 generated during formation of the polyfunctional organohydrogensiloxane; 3) neutralizing residual boron containing Lewis acid in the organohydrogensiloxane dendrimer and/or 4) removing a particulate.

14. The method of claim 6 , further comprising:
combining a) the polyfunctional organohydrogensiloxane,
b) a hydrosilylation reaction catalyst, and
c) a reactive species having an average, per molecule at least one aliphatically unsaturated group capable of undergoing an addition reaction with a silicon bonded hydrogen atom of starting material b) and further comprising one or more curable groups per molecule; thereby preparing a product comprising a clustered functional organosiloxane.

15. The method of claim 14 , where the reactive species comprises a silane of formula R 4 y SiR 5 (4−y) , where subscript y is 1 to 3, each R 4 is the aliphatically unsaturated group capable of undergoing an addition reaction, and each R 5 is the curable group; thereby preparing a product comprising a clustered-functional polyorganosiloxane dendrimer.

16. The method of claim 15 , where subscript y=1; each R 4 is independently selected from the group consisting of alkenyl and alkynyl; and each R 5 is independently selected from the group consisting of an organic group containing an acrylate group, an alcohol group, an alkoxy group, an epoxy group, an isocyanate group, a methacrylate group, or a urethane group.

17. The method of claim 14 , where each aliphatically-unsaturated group is independently selected from the group consisting of alkenyl and alkynyl; and curable group is independently selected from the group consisting of an organic group containing an acrylate group, an alcohol group, an alkoxy group, an epoxy group, an isocyanate group, a methacrylate group, or a urethane group.

18. A curable composition comprising:
(I) the clustered functional organosiloxane of claim 1 and
(II) a curing agent.

19. An adhesive composition comprising:
A) clustered functional organosiloxane of unit formula:

where subscript n is 2 to 2,000, each subscript d is independently 0 to 995, subscript o′=0 to 100, subscript n′=(o′+1), each R is an independently selected monovalent hydrocarbon group, each R 1 is independently selected from the group consisting of monovalent hydrocarbon groups and monovalent halogenated hydrocarbon groups, and each R 8 is a hydrogen atom or a curable group, with the proviso that at least one R 8 per molecule is a curable group other than hydrogen;
B) a reactive resin and polymer,
C) a condensation reaction catalyst, and
D) a free radical initiator; and
optionally, one or more additional starting materials selected from the group consisting of E) a dual cure compound, F′) an adhesion promoter, G) a corrosion inhibitor, H) a rheology modifier, I) a drying agent, J) a crosslinker, K) a filler, L) a spacer, M) an acid scavenger, N) a silanol functional polydiorganosiloxane, O ) a fluorescent optical brightener, P) a chain transfer agent, Q) a (methacrylate monomer, R) a poly-alkoxyterminated polydiorganosiloxane, and S) a colorant.

Assignees

• Dow Silicones Corp

Inventors

• Joffre Eric
• Liu Nanguo
• Lu Gang
• Niu Zhenbin
• Rich David

Classifications

• C08G77/12 Primary

  containing silicon bound to hydrogen · CPC title

• C08G77/06

  Preparatory processes · CPC title

• C08G77/08

  characterised by the catalysts used · CPC title

• C08G77/38

  Polysiloxanes modified by chemical after-treatment · CPC title

• C08G77/382

  containing atoms other than carbon, hydrogen, oxygen or silicon · CPC title