Perfluoroelastomer articles having good surface properties
View Patent ↗Cured perfluoroelastomer articles are disclosed which have improved surface characteristics. The articles are coated with a thin durable film comprising a fluorocarbon telomer which reduces surface stickiness, while maintaining the sealing properties of the article.
1. A cured perfluoroelastomer article for use as a vacuum seal in a high temperature environment, said article having at least a portion of a surface coated with a film having a thickness between 0.1 and 20 microns, said film consisting of a fluorocarbon telomer selected from the group consisting of polytetrafluoroethylene, tetrafluoroethylene/perfluoroalkoxy copolymer (PFA) and fluorinated ethylene/propylene copolymer (FEP), said fluorocarbon telomer having a weight average molecular weight between 1000 and 10000.
2. A cured perfluoroelastomer article of claim 1 wherein said perfluoroelastomer comprises copolymerized units of tetrafluoroethylene, a perfluorinated vinyl ether and a cure site monomer.
3. A cured perfluoroelastomer article of claim 2 wherein said perfluoroelastomer comprises copolymerized units of 53.0-79.6 mole percent tetrafluoroethylene, 20.0-46.6 mole percent perfluoro(methyl vinyl ether) and 0.4-1.5 mole percent nitrile-containing cure site monomer.
4. A cured perfluoroelastomer article of claim 1 wherein said fluorocarbon telomer is polytetrafluoroethylene.
5. A cured perfluoroelastomer article of claim 1 wherein said fluorocarbon telomer has a weight average molecular weight between 2000 and 4000.
6. A cured perfluoroelastomer article of claim 1 wherein said film has a thickness between 3 and 10 microns.