Low platinum content hydrosilylation reaction-crosslinked silicone rubber powder
View Patent ↗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.
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.