Polyhydroxy curable fluoroelastomer compositions
View Patent ↗Disclosed herein is a curable composition comprising a polyhydroxy curable fluoroelastomer, a polyhydroxy curative, a cure accelerator and an unsaturated metal compound process aid. Such curable compositions have a lower Mooney viscosity than do similar compositions absent the process aid.
1. A curable fluoroelastomer composition comprising:
A) a polyhydroxy curable fluoroelastomer consisting essentially of
i) vinylidene fluoride, hexafluoropropylene, and optionally tetrafluoroethylene,
ii) vinylidene fluoride, perfluoro(alkyl vinyl ether), 2-hydropentafluoropropylene, and optionally tetrafluoroethylene;
iii) tetrafluoroethylene, propylene, and optionally 3,3,3-trifluoropropene;
iv) tetrafluoroethylene, perfluoro(methyl vinyl ether) and hexafluoro-2-(pentafluorophenoxy)-1-(trifluorovinyloxy) propane, or
v) ethylene, tetrafluoroethylene, perfluoro(methyl vinyl ether), and optionally 3,3,3-trifluoropropylene;
B) a polyhydroxy curative;
C) a cure accelerator; and
D) an unsaturated metal compound process aid having the formula Y (4-n) MX n wherein Y is selected from alkyl, aryl, carboxylic acid, or alkyl ester groups; M is selected from Si, Ge, or Sn; X is an allyl group CR 1 R 2 CR 3 ═CR 4 R 5 , vinyl group CR 1 ═CR 2 R 3 , allenyl group CR 1 ═C═CR 2 R 3 , alkynyl group C≡CR 1 , or propargyl group CR 1 R 2 C≡CR 3 ; R 1 -R 5 are selected independently from the group consisting of H, F, alkyl, aryl, heterocycle, or perfluoroalkyl groups; and n is 1,2, or 3.
2. The curable composition of claim 1 wherein said unsaturated metal compound process aid is of the formula Y (4-n) MX n wherein M is Sn, X is allyl group CR 1 R 2 CR 3 ═CR 4 R 5 , Y is alkyl or aryl, R 1 -R 5 are H and n is 1 or 2.
3. The curable composition of claim 2 wherein said unsaturated metal compound process aid is allyltrioctylstannane.
4. The curable composition of claim 2 wherein said unsaturated metal compound process aid is allyltriphenylstannane.
5. The curable composition of claim 2 wherein said unsaturated metal compound process aid is diallyldioctylstannane.
6. The curable composition of claim 1 wherein said unsaturated metal compound process aid is of the formula Y (4-n) MX n wherein M is Sn, X is vinyl group CR 1 ═CR 2 R 3 , Y is alkyl or aryl, R 1 -R 3 are H and n is 1.
7. The curable composition of claim 6 wherein said unsaturated metal compound process aid is vinyltrioctylstannane.
8. The curable composition of claim 6 wherein said unsaturated metal compound process aid is vinyltriphenylstannane.
9. The curable composition of claim 1 wherein said unsaturated metal compound process aid is of the formula Y (4-n) MX n wherein M is Ge, X is allyl group CR 1 R 2 CR 3 ═CR 4 R 5 , Y is alkyl or aryl, R 1 -R 5 are H and n is 1.
10. The curable composition of claim 9 wherein said unsaturated metal compound process aid is allyltrioctylgermane.
11. The curable composition of claim 9 wherein said unsaturated metal compound process aid is allyltriphenylgermane.
12. The curable composition of claim 1 wherein said unsaturated metal compound process aid is of the formula Y (4-n) MX n wherein M is Si, X is allyl group CR 1 R 2 CR 3 ═CR 4 R 5 , Y is alkyl or aryl, R 1 -R 5 are H and n is 1.
13. The curable composition of claim 12 wherein said unsaturated metal compound process aid is allyltriphenylsilane.
14. The curable composition of claim 1 wherein said unsaturated metal compound process aid is of the formula Y (4-n) MX n wherein M is Si, X is vinyl group CR 1 ═CR 2 R 3 , Y is alkyl or aryl, R 1 -R 3 are H and n is 1.
15. The curable composition of claim 14 wherein said unsaturated metal compound process aid is triphenyl(vinyl)silane.