# US 5,703,185 A · Fluoropolymer extrusion process

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- Number: US 5,703,185 A
- Document ID: US5703185A
- Status: Granted
- Kind: A
- Application number: 08/685,083
- Filed: 1996-07-23
- Granted: 1997-12-30
- Earliest claimed: 1996-07-23
- Assignees: E. I. Du Pont de Nemours and Company
- Inventors: Leslie Mitchell Blair
- Web page: https://patentgrep.com/patent/US5703185A

## CPC

- H01B 3/445: {from vinylfluorides or other fluoroethylenic compounds}
- H01B: CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES (selection for magnetic properties H01F1/00; waveguides H01P {; printed circuits H05K})

## Abstract

Copolymers of tetrafluoroethylene, hexafluoropropylene, and perfluoro(ethyl vinyl ether) can be extruded at higher rates than corresponding copolymers containing perfluoro(propyl vinyl ether).

## Claims

### Claim 1

A process comprising extruding and melt drawing a tetrafluoroethylene copolymer resin to form insulation on an electrical conductor, wherein said copolymer is partially-crystalline copolymer comprising tetrafluoroethylene, hexafluoropropylene in an amount corresponding to HFPI of from 2.0 to about 5.3, and from 0.2% to 3% by weight of perfluoro(ethyl vinyl ether).

### Claim 2 (depends on 1)

The process of claim 1, wherein the amount of perfluoro(ethyl vinyl ether) in said copolymer is from 0.5% to 2.5% by weight.

### Claim 3 (depends on 2)

The process of claim 2, wherein the amount of said hexafluoropropylene in said copolymer corresponds to HFPI of from 2.8 to 4.1.

### Claim 4 (depends on 1)

The process of claim 1, wherein said copolymer has a melt viscosity of no more than 10.times.10.sup.3 Pa.s.