Low platinum content hydrosilylation reaction-crosslinked silicone rubber powder

Patent metadata

Field	Value
Publication number	US-9561171-B2
Application number	US-201314654625-A
Country	US
Kind code	B2
Filing date	Dec 13, 2013
Priority date	Dec 22, 2012
Publication date	Feb 7, 2017
Grant date	Feb 7, 2017

Abstract

A method to produce a hydrosilylation reaction-crosslinkable silicone rubber powder includes washing the hydrosilylation reaction-crosslinkable silicone rubber powder using an aqueous solution. The aqueous solution can be heated to a temperature of 30° C. to 99° C. The aqueous solution contains at least one type of surfactant. The hydrosilylation reaction-crosslinkable silicone rubber powder produced via the method has a platinum metal content ≦3.5 ppm by mass. The hydrosilylation reaction-crosslinkable silicone rubber powder can be used for various applications, including use in a cosmetic composition, which can also include a cosmetic raw material.

First claim

The invention claimed is:

1. A hydrosilylation reaction-crosslinked silicone rubber powder having a platinum metal content ≦3.5 ppm by mass.

2. The hydrosilylation reaction-crosslinked silicone rubber powder as claimed in claim 1 , wherein the platinum metal content is in a range of 1.5 to 3.0 ppm by mass.

3. The hydrosilylation reaction-crosslinked silicone rubber powder as claimed in claim 1 , wherein the average particle diameter of the silicone rubber powder is from 0.1 μm to 10 mm.

4. The hydrosilylation reaction-crosslinked silicone rubber powder as claimed in claim 1 , obtained by washing a silicone rubber powder containing at least 5 ppm by mass of platinum metal using an aqueous solution heated to a temperature of 30° C. to 99° C. and containing at least one type of surfactant.

5. A method of producing a hydrosilylation reaction-crosslinked silicone rubber powder, the method comprising:
washing a silicone rubber powder containing at least 5 ppm by mass of platinum metal using an aqueous solution of at least one type of surfactant to lower platinum content in the silicone rubber powder;
wherein the hydrosilylation reaction-crosslinked silicone rubber powder produced has a platinum metal content ≦3.5 ppm by mass.

6. The method as claimed in claim 5 , wherein the surfactant is selected from the group consisting of anionic surfactants, cationic surfactants, nonionic surfactants, and amphoteric surfactants.

7. The method as claimed in claim 5 , wherein the aqueous solution of at least one type of surfactant is heated to a temperature of 30° C. to 99° C.

8. The method as claimed in claim 5 , wherein the concentration of surfactant in the aqueous solution is in the range of 0.1 to 10% by mass.

9. The method as claimed in claim 5 , wherein the surfactant is a nonionic surfactant.

10. The method as claimed in claim 9 , wherein the surfactant is selected from a polyoxyethylene alkyl ether or a sodium diethylhexyl sulfosuccinate.

11. A method of producing a hydrosilylation reaction-crosslinked silicone rubber powder, the method comprising
(a) producing a silicone rubber powder by curing a composition comprising:
(A) an organopolysiloxane having at least two alkenyl groups in a molecule;
(B) an organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms in a molecule; and
at least 5.0 ppm by mass of a platinum-based catalyst, in terms of a platinum metal content, relative to the mass of a cured product resulting from crosslinking component (A) and component (B); and

(b) washing at least once the silicone rubber powder using at least 50 parts by mass of an aqueous solution heated to a temperature of 30° C. to 99° C. containing at least 0.1% by mass of at least one type of surfactant, per 100 parts by mass of the silicone rubber powder,
to obtain a silicone rubber powder having a platinum metal content ≦3.5 ppm by mass.

12. A cosmetic composition comprising:
(i) hydrosilylation reaction-crosslinked silicone rubber powder as claimed in claim 1 ; and
(ii) at least one cosmetic raw material.

13. The hydrosilylation reaction-crosslinked silicone rubber powder as claimed in claim 2 , wherein the average particle diameter of the powder is from 0.1 μm to 10 mm.

14. The hydrosilylation reaction-crosslinked silicone rubber powder as claimed in claim 13 , obtained by washing a silicone rubber powder containing at least 5 ppm by mass of platinum metal using an aqueous solution heated to a temperature of 30° C. to 99° C. containing at least one type of surfactant.

15. The method as claimed in claim 5 , wherein the platinum metal content is in a range of 1.5 to 3.0 ppm by mass.

16. The method as claimed in claim 6 , wherein the aqueous solution of at least one type of surfactant is heated to a temperature of 30° C. to 99° C.

17. The method as claimed in claim 16 , wherein the concentration of surfactant in the aqueous solution is in the range of 0.1 to 10% by mass.

18. The method as claimed in claim 11 , wherein the platinum metal content is in a range of 1.5 to 3.0 ppm by mass.

19. The method as claimed in claim 11 , wherein the concentration of surfactant in the aqueous solution is in the range of 0.1 to 10% by mass.

20. The method as claimed in claim 19 , wherein the surfactant is a nonionic surfactant, alternatively is selected from a polyoxyethylene alkyl ether or a sodium diethylhexyl sulfosuccinate.

Assignees

• Dow Corning Toray Co Ltd

Inventors

• Wakita Mari

Classifications

• C08K5/56

  Organo-metallic compounds, i.e. organic compounds containing a metal-to-carbon bond · CPC title

• C08L83/00

  Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon only; Compositions of derivatives of such polymers · CPC title

• A61K8/0245

  Specific shapes or structures not provided for by any of the groups of A61K8/0241 · CPC title

• A61K8/895 Primary

  containing silicon bound to unsaturated aliphatic groups, e.g. vinyl dimethicone · CPC title

• C08G77/34

  Purification · CPC title