Process for preparing platinum organosiloxane complexes

Patent metadata

Field	Value
Publication number	US-10787474-B2
Application number	US-201816617662-A
Country	US
Kind code	B2
Filing date	Jul 18, 2018
Priority date	Jul 20, 2017
Publication date	Sep 29, 2020
Grant date	Sep 29, 2020

Abstract

A platinum organosiloxane complex is prepared by a process including 1) combining A) a platinous halide and B) a ketone, and thereafter 2) adding C) a polyorganosiloxane having, per molecule, 2 to 4 silicon bonded terminally unsaturated hydrocarbon groups having from 2 to 6 carbon. The platinum organosiloxane complex prepared by the process is useful as a hydrosilylation catalyst.

First claim

The invention claimed is:

1. A process for forming a product comprising a platinum organosiloxane complex, wherein the process comprises:
1) combining by mixing for at least 2 hours at 50° C. to 90° C. or by milling for at least 1 hour at 50° C. to 90° C.
A) a platinous halide, and
B) a ketone,

where milling is performed by adding inert particles to a container containing the starting materials in step 1) and subjecting the container to rolling or agitation, and thereafter;
2) adding starting materials comprising
C) a polyorganosiloxane having, per molecule, 2 to 4 silicon bonded terminally unsaturated organic groups having from 2 to 6 carbon atoms and any remaining silicon bonded organic groups being monovalent hydrocarbon groups of 1 to 12 carbon atoms;

wherein Yield of the present process is not dependent upon particle size and/or crystallite size of the platinous halide selected for starting material A).

2. The process of claim 1 , where the platinous halide is platinum dichloride.

3. The process of claim 1 , where the platinous halide comprises 0.3% to 10% zero valent platinum.

4. The process of claim 1 , where the ketone is methyl ethyl ketone.

5. The process of claim 1 , where the polyorganosiloxane is a vinyl terminated polydimethylsiloxane.

6. The process of claim 1 , further comprising: adding D) an enone additive during step 1).

7. The process of claim 6 , where D) the enone additive is a compound of formula (I) and/or formula (II), where formula (I) is

and formula (II), is

where R1 to R10 are each independently selected from hydrogen, an alkyl group having from 1 to 6 carbon atoms, or a phenyl group, or where any two of R1 to R10 may combine to form one or more carbocyclic groups; with the proviso that when R1 is methyl, one of R2 and R3 is hydrogen and the other of R2 and R3 is methyl, and R5 and R6 are both hydrogen; then R4 is not methyl.

8. The process of claim 1 , where step 1) is performed from 4 to 16 hours before step 2).

9. The process of claim 1 , where step 1) is performed by heating for 5 to 8 hours at a temperature of 85° C. to 90 C.

10. The process of claim 1 , where step 2) is performed by heating at 50° C. to 85° C. for 2 to 12 hours.

11. The process of claim 1 , further comprising step 3) neutralizing the product formed by step 1).

12. The process of claim 1 , further comprising 4) recovering the platinum organosiloxane complex.

13. The process of claim 2 , where the platinous halide comprises 0.3% to 10% zero valent platinum.

Assignees

• Dow Silicones Corp

Inventors

• Dash Aswini
• Li Zhanjie
• Millward Andrew
• Tzou Ming-Shin

Classifications

• C07F15/0086 Primary

  Platinum compounds · CPC title

• C07F7/0829

  Hydrosilylation reactions · CPC title

• C07B47/00

  Formation or introduction of functional groups not provided for in groups C07B39/00 - C07B45/00 · CPC title

• B01J23/42

  Platinum · CPC title