Blends of fluoroplastics and fluoroelastomers

Claim 2

A melt blended composition comprising l00 parts by weight of a cured fluoroelastomer consisting essentially of from 79.9 to 52 mole % units derived from tetrafluoroethylene, 20 to 45 mole % units derived from a perfluoroalkylvinyl ether wherein the alkyl group contains from l to l0 carbon atoms, and 0.l to 4.0 mole % cure site monomer units derived from vinylidene fluoride, trifluoroethylene, vinyl fluoride, CH₂=CHF f where R f is a perfluoroalkyl group containing from l to 5 carbon atoms, perfluorophenoxy substituted perfluoroalkylene vinyl ethers wherein the perfluoroalkylene group contains from l to 5 carbon atoms, N C(R′ f -O) n CF=CF₂ where R′ f is a perfluoroalkylene group of 2 or 3 carbon atoms and n is l-4, fluoroolefins of 2 to 5 carbon atoms containing l or 2 bromo substituents or fluoroolefins of 2 to 5 carbon atoms, containing l or 2 iodo substituents, and from 2 to 50 parts by weight of a thermoplastic perfluorocarbon copolymer containing at least 5 mole % units derived from tetrafluoroethylene having a melting point above 300°C which is present as generally spherical particles having a particle size of less than about l0 microns.

Claim 3

The composition of Claim l wherein the thermoplastic perfluorocarbon contains 50 to 98 mole % units derived from tetrafluoroethylene and 2 to 50 mole % units derived from hexafluoropropylene or a perfluoroalkylvinyl ether wherein the perfluoroalkyl group contains from l to l0 carbon atoms.

Claim 4

The composition of Claim l or 2 wherein the fluoroelastomer contains from 74.8 to 57 mole % units derived from tetrafluoroethylene, 25 to 40 mole % units derived from perfluoroalkylvinyl ether and 0.2 to 3.0 mole % cure site monomer derived units.

Claim 5

The composition of Claim 1, 2 or 3 wherein the thermoplastic perfluorocarbon contains from 97 to 75 mole % units derived from tetrafluoroethylene and 3 to 25 mole % units derived from hexafluoropropylene or perfluoroalkylvinyl ether.

Claim 6

The composition of any one of Claims 1 to 4 wherein there is present from 5 to 3O parts by weight thermoplastic perfluorocarbon copolymer per lOO parts by weight fluoroelastomer.

Claim 7

The composition of any one of Claims 1 to 5 wherein a curing agent is present adapted to cure the cure site monomer units present.

Claim 8

A process of preparing a blend of l00 parts of fluoroelastomer consisting essentially of from 79.9 to 52 mole % units derived from tetrafluoroethylene, 20 to 45 mole % units derived from a perfluoroalkylvinyl ether wherein the alkyl group contains from l to l0 carbon atoms, and 0.l to 4.0 mole % cure site monomer units derived from a vinylidene fluoride, trifluoroethylene, vinyl fluoride, CH₂=CHR f where R f is a perfluoroalkyl group containing from l to 5 carbon atoms, perfluorophenoxy substituted perfluoroalkylene vinyl ethers wherein the perfluoroalkylene group contains from l to 5 carbon atoms, N C(R′ f -O) n CF=CF₂ where R′ f is a perfluoroalkylene group of 2 or 3 carbon atoms and n is 1-4, fluoroolefins containing l or 2 bromo substituents or fluoroolefins of 2 to 5 carbon atoms containing l or 2 iodo substituents, and from 2 to 50 parts by weight of a thermoplastic copolymer containing at least 50 mole % units derived from tetrafluoroethylene comprising blending said fluoroelastomer and thermoplastic copolymer at a temperature above the melting point of the thermoplastic copolymer followed by addition of curing ingredients at below l00°C and curing the fluoroelastomer.

Claim 9

A process of preparing a blend of l00 parts of fluoroelastomer consisting essentially of from 79.9 to 52 mole % units derived from tetrafluoroethylene, 20 to 45 mole % units derived from a perfluoroalkylvinyl ether wherein the alkyl group contains from l to l0 carbon atoms, and 0.l to 4.0 mole % cure site monomer units derived from a vinylidene fluoride, trifluoroethylene, vinyl fluoride, CH₂=CHR f where R f is a perfluoroalkyl group containing from l to 5 carbon atoms, perfluorophenoxy substituted perfluoroalkylene vinyl ethers wherein the perfluoroalkylene group contains from l to 5 carbon atoms, N C(R′ f -O) n CF=CF₂ where R′ f is a perfluoroalkylene group of 2 or 3 carbon atoms and n is 1-4, fluoroolefins containing l or 2 bromo substituents or fluoroolefins of 2 to 5 carbon atoms containing l or 2 iodo substituents, and from 2 to 50 parts by weight of a thermoplastic copolymer containing at least 50 mole % units derived from tetrafluoroethylene comprising blending said fluoroelastomer and thermoplastic copolymer at a temperature above the melting point of the thermoplastic copolymer followed by addition of curing ingredients at below l00°C and curing the fluoroelastomer.

Claim 10

The process of Claim 7 wherein the thermoplastic perfluorocarbon contains 50 to 98 mole % units derived from tetrafluoroethylene and 2 to 50 mole % units derived from hexafluoropropylene or a perfluoroalkylvinyl ether wherein the alkyl group contains from l to l0 carbon atoms.

Claim 11

The process of Claim 7 or 8 wherein the fluoroelastomer contains from 74.8 to 57 mole % units derived from tetrafluoroethylene, 25 to 4O mole % units derived from perfluoroalkylvinyl ether and O.2 to 3.O mole % cure site monomer derived units.

Claim 12

1O. The process of any one of Claims 7 to 9 wherein the thermoplastic perfluorocarbon contains from 97 to 75 mole % units derived from tetrafluoroethylene and 3 to 25 mole % units derived from hexafluoropropylene or perfluoroalkylvinyl ether.

Claim 13

The process of any one of Claims 7 to 1O wherein there is present from 5 to 3O parts by weight thermo­plastic perfluorocarbon copolymer per 1OO parts by weight fluoroelastomer.