Granted Patent B2

US 12,281,224 · App. 16/317,911 · Granted Apr 22, 2025

Inventor: Christopher J. Bish (Kennett Square, PA)

Assignee: DUPONT POLYMERS, INC.

C08L27/18C08K3/04C08K3/22C08K3/30C08K5/25C08L27/20C08L29/10C08K2003/2241C08K2003/3045C08K2201/005

Abstract

Claims (23)

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.

2. The perfluoroelastomer compound of claim 1 , wherein the cure site monomer comprises a nitrile group.

3. The perfluoroelastomer compound of claim 1 , wherein the cure site monomer is a nitrile-containing perfluorinated vinyl ether.

4. The perfluoroelastomer compound of claim 1 , wherein the carbon black has a particle size of at least 100 nm.

5. An article comprising the cured perfluoroelastomer compound of claim 1 .

6. The article of claim 5 in the form of a gasket, seal, tubing, diaphragm, or O-ring.

7. A process for preparing the perfluoroelastomer compound of claim 1 , comprising the step of:

1) mixing a perfluoroelastomer compound that comprises:

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.

Assignments (8)

Continuity (2)

References Cited (22)