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 comprising a siloxane having at least one vinyl or allyl group bonded to a silicon atom. 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;
B) a polyhydroxy curative;
C) a cure accelerator; and
D) an unsaturated metal compound process aid comprising a siloxane having at least one vinyl or allyl group bonded to a silicon atom, wherein said unsaturated metal compound process aid is:
1,5-divinyl-3,3-diphenyl-1,1,5,5-tetramethyltrisiloxane,
1,3-divinyl-1,3-diphenyl-1,3-dimethyldisiloxane,
1,5-divinylhexamethyltrisiloxane,
1,3-divinyltetraphenyldisiloxane, or
vinyl terminated diphenylsiloxane-dimethylsiloxane copolymer.
2. The curable composition of claim 1 wherein said unsaturated metal compound process aid is 1,5-divinyl-3,3-diphenyl-1,1,5,5-tetramethyltrisiloxane.
3. The curable composition of claim 1 wherein said unsaturated metal compound process aid is 1,3-divinyl-1,3-diphenyl-1,3-dimethyldisiloxane.
4. The curable composition of claim 1 wherein said unsaturated metal compound process aid is 1,5-divinylhexamethyltrisiloxane.
5. The curable composition of claim 1 wherein said unsaturated metal compound process aid is 1,3-divinyltetraphenyldisiloxane.
6. The curable composition of claim 1 wherein said unsaturated metal compound process aid is vinyl terminated diphenylsiloxane-dimethylsiloxane copolymer.