Curable fluoroelastomer composition
View Patent ↗Fluoroelastomer compositions comprising fluoroelastomers having copolymerized units of a nitrile group-containing cure site monomer are cured with certain hydroxylamine derivatives. The hydroxylamine derivative is of formula R 1 (C(O)) n NHOR 2 wherein n is 0 or 1; R 1 is H, C(O)R 3 , C(O)R 4 , C(O)OR 3 , or C(O)SR 3 ; R 2 is H, C(O)R 3 , or C(O)OR 3 ; R 3 is C 1 -C 20 alkyl group, aryl, heterocycle, benzyl, 9-fluorenylmethyl, or CH 2 R 4 ; and R 4 is a fluoroalkyl group, with the proviso that R 1 and R 2 cannot simultaneously be H.
1. A curable composition comprising:
A. a fluoroelastomer comprising copolymerized units of a nitrile group-containing cure site monomer; and
B. an hydroxylamine derivative of formula R 1 (C(O)) n NHOR 2 wherein n is 0 or 1; R 1 is H, C(O)R 3 , C(O)R 4 , C(O)OR 3 , or C(O)SR 3 ; R 2 is H, C(O)R 3 , or C(O)OR 3 ; R 3 is C 1 -C 20 alkyl group, aryl, heterocycle, benzyl, 9-fluorenylmethyl, or CH 2 R 4 ; and R 4 is a fluoroalkyl group, with the proviso that R 1 and R 2 cannot simultaneously be H.
2. A curable composition of claim 1 wherein n is 0; R 1 is H and R 2 is C(O)R 3 .
3. A curable composition of claim 1 wherein n is 0; R 1 is H and R 2 is C(O)OR 3 .
4. A curable composition of claim 1 wherein n is 0; R 1 is C(O)R 3 and R 2 is H.
5. A curable composition of claim 1 wherein n is 0; R 1 is C(O)R 4 and R 2 is H.
6. A curable composition of claim 1 wherein n is 0; R 1 is C(O)R 3 and R 2 is C(O)OR 3 .
7. A curable composition of claim 1 wherein n is 0; R 1 is C(O)OR 3 and R 2 is C(O)OR 3 .
8. A curable composition of claim 1 wherein the hydroxylamine derivative is selected from the group consisting of acetohydroxamic acid, benzyl-N-hydroxycarbamate, tert-butyl N-hydroxycarbamate, benzohydroxamic acid, N,O-(tert-butoxycarbonyl)hydroxylamine, succinohydroxamic acid, and benzoyloxyamine hydrochloride.
9. A curable composition of claim 1 further comprising a curative accelerator.
10. A cured article formed from the composition of claim 1 .