US 12,281,224 B2
Fluoroelastomer compounds
Christopher J. Bish, Kennett Square, PA (US)
Assigned to DUPONT POLYMERS, INC., Wilmington, DE (US)
Appl. No. 16/317,911
Filed by E I DU PONT DE NEMOURS AND COMPANY, Wilmington, DE (US)
PCT Filed Aug. 9, 2017, PCT No. PCT/US2017/046030
§ 371(c)(1), (2) Date Jan. 15, 2019,
PCT Pub. No. WO2018/038917, PCT Pub. Date Mar. 1, 2018.
Claims priority of provisional application 62/379,713, filed on Aug. 25, 2016.
Prior Publication US 2021/0292534 A1, Sep. 23, 2021
Int. Cl. C08L 27/18 (2006.01); C08K 3/04 (2006.01); C08K 3/22 (2006.01); C08K 3/30 (2006.01); C08K 5/25 (2006.01); C08L 27/20 (2006.01); C08L 29/10 (2006.01)
CPC C08L 27/18 (2013.01) [C08K 3/04 (2013.01); C08K 3/22 (2013.01); C08K 3/30 (2013.01); C08K 5/25 (2013.01); C08L 27/20 (2013.01); C08L 29/10 (2013.01); C08K 2003/2241 (2013.01); C08K 2003/3045 (2013.01); C08K 2201/005 (2013.01)] 7 Claims
 
1. A curable perfluoroelastomer compound comprising:
A. a perfluoroelastomer comprising copolymerized units of:
(1) tetrafluoroethylene, hexafluoropropylene, or a mixture of these;
(2) at least one perfluoro(alkyl vinyl) ether, perfluoro(alkoxy vinyl) ether, or a mixture of these; and
(3) one or more cure site monomers comprising a functional group selected from the group consisting of nitrile groups, bromine atoms, and iodine atoms;
B. from 10 to 100 phr of at least one carbon black having a particle size of at least 60 nm;
C. from 1 to 35 phr of a mineral filler, wherein the mineral filler is barium sulfate; and
D. a curing agent, wherein the curing agent is selected from the group consisting of oxalyl dihydrazide, carbohydrazide, isophthalic dihydrazide, and t-butyl carbazate;
wherein said perfluoroelastomer compound in the shape of an O-ring, after curing and exposure to distilled water at 225° C. under 20 percent compression for 1500 hours using Wykeham-Farrence testing equipment, exhibits a sealing force retention measured at 90° C. which is at least 25 percent greater than an identical perfluoroelastomer compound lacking said mineral filler.