Silicone-organic elastomer gels
View Patent ↗Gel compositions are disclosed containing a silicone organic elastomer from the reaction of an organohydrogensiloxane having at least two SiH containing cyclosiloxane rings in its molecule, a compound or mixture of compounds having at least two aliphatic unsaturated groups in its molecule, and a hydrosilylation catalyst. The silicone elastomer reaction product may itself be a gelled composition, or optionally may be contained in a carrier fluid to form a gel. The gel compositions may further contain a personal or healthcare active.
1. A gel composition comprising a silicone organic elastomer from the reaction of;
A) an organohydrogensiloxane prepared by a hydrosilylation reaction of
a) an organohydrogencyclosiloxane having at least two SiH units on the siloxane ring and,
B) a compound or mixture of compounds having at least two aliphatic unsaturated hydrocarbon groups in its molecule,
wherein the molar ratio of SiH units of a) the organohydrogencyclosiloxane to aliphatic unsaturated groups of component B) used in the hydrosilylation reaction ranges from 2/1 to 8/1,
B 1 ) an α, ω-unsaturated alkene or alkyne containing 1 to 30 carbons,
C) a hydrosilylation catalyst, and
D) a carrier fluid,
wherein the gel composition has a compression hardness of at least 200 Newton/m 2 .
2. The composition of claim 1 further comprising;
E) a personal care or healthcare active.
3. The composition of claim 1 wherein a) the organohydrogencyclosiloxane having at least two SiH units on the siloxane ring has the formula [(CH 3 )HSiO] g where g is 3-8.
4. The composition of claim 1 wherein B) the compound containing at least two aliphatic unsaturated hydrocarbon groups in its molecule is selected from a compound having the formula R 2 —Y—R 2 where R 2 is a monovalent unsaturated aliphatic group containing 2 to 12 carbon atoms and Y is a divalent hydrocarbon, a siloxane, a polyoxyalkylene, a polyalkylene, a polyisoalkylene, a hydrocarbon-silicone copolymer, or mixtures thereof.
5. The composition of claim 1 wherein component B) comprises 1,5 hexadiene.
6. The composition of claim 1 wherein B) the compound containing at least two aliphatic unsaturated hydrocarbon groups is selected from an organopolysiloxane comprising at least two siloxane units having a formula R 2 R m SiO (4-m)/2
wherein
R is an organic group,
R 2 is a monovalent unsaturated aliphatic hydrocarbon group, and
m is zero to 3.
7. The composition of claim 6 wherein the organopolysiloxane has the formula
(R 2 R 2 SiO 0.5 )(SiO 2 ) w (R 2 R 2 SiO 0.5 )
(R 2 R 2 SiO 0.5 )(SiO 2 ) w (R 2 SiO) x (R 2 R 2 SiO 0.5 ),
R 2 SiO 0.5 )(R 2 SiO) x (R 2 R 2 SiO 0.5 ),
(R 3 SiO 0.5 )(R 2 SiO) x (R 2 RSiO) y (R 3 SiO 0.5 ),
(R 3 SiO 0.5 )(R 2 SiO) x (R 2 RSiO) y (RSiO 1.5 ) z (R 3 SiO 0.5 ), or
(R 3 SiO 0.5 )(R 2 SiO) x (R 2 RSiO) y (SiO 2 ) w (R 3 SiO 0.5 ),
where w≧0, x≧0, y≧2, and z is ≧0, R is an organic group, and
R 2 is a monovalent unsaturated aliphatic hydrocarbon group.
8. The composition of claim 7 wherein R is methyl and R 2 is CH 2 ═CH— or CH 2 ═CH—(CH 2 ) 4 —.
9. The composition of claim 7 wherein the organopolysiloxane is a vinyl functional polydimethylsiloxane or hexenyl functional polydimethylsiloxane having the average formula;
CH 2 ═CH(Me) 2 SiO[Me 2 SiO] x Si(Me) 2 CH═CH 2
CH 2 ═CH(CH 2 ) 4 (Me) 2 SiO[Me 2 SiO] x Si(Me) 2 (CH 2 ) 4 CH═CH 2 , or
Me 3 SiO[(Me) 2 SiO] x [CH 2 ═CH(Me)SiO] y SiMe 3
wherein Me is methyl, x≧0, and y≧2.
10. The composition of claim 4 wherein Y in the R 2 —Y—R 2 compound is a hydrocarbon-silicone copolymer group having the formula
—[R 1 u (R 2 SiO) v ] q —
where R 1 is a divalent hydrocarbon, R is an organic group,
u and v are independently ≧1, and q is >1.
11. The composition of claim 1 wherein
R is methyl,
R 1 is hexylene,
u=1, v and q is >1.
12. The composition of claim 11 wherein v ranges from 2 to 500.
13. The composition of claim 11 where q ranges from 2 to 100.
14. The composition of claim 4 wherein Y in the R 2 —Y—R 2 compound is a polyalkylene group.
15. The composition of claim 4 wherein Y in the R 2 —Y—R 2 compound is polyisobutylene.
16. The composition of claim 1 wherein C) the hydrosilylation catalyst is a platinum group containing catalyst.
17. The composition of claim 1 wherein the molar ratio of A)/B) is from 10/1 to 1/10.
18. The composition of claim 1 wherein the carrier fluid is a silicone or organic fluid having a viscosity at 25° C. in the range of 1 to 1,000 mm 2 /sec.
19. The composition of claim 1 wherein the carrier fluid is decamethylcyclopentasiloxane, isododecane, or isodecyl neopentanoate.
20. The composition of claim 2 wherein E) is a personal care active selected from a vitamin, sunscreen, plant extract, or fragrance.
21. The composition of claim 2 wherein E) is a health care active selected from a topical drug active, protein, enzyme, antifugual, or antimicrobial agent.
22. The composition of claim 2 wherein component E) is vitamin A palmitate.
23. The composition of claim 2 wherein component E) is octyl methoxycinnamate.
24. A process for preparing a gel paste composition comprising;
I) shearing the silicone elastomer gel of claim 1 ,
II) combining the sheared silicone elastomer gel with additional quantities of
D) the carrier fluid to form a gel paste composition.
25. The process of claim 24 further comprising the addition of
E) a personal care or healthcare active in step II).
26. The gel paste composition prepared according to the process of claim 24 .