| (19) |
 |
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(11) |
EP 0 521 588 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
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08.09.1993 Bulletin 1993/36 |
| (43) |
Date of publication A2: |
|
07.01.1993 Bulletin 1993/01 |
| (22) |
Date of filing: 26.04.1991 |
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| (84) |
Designated Contracting States: |
|
DE ES FR GB IT SE |
| (30) |
Priority: |
27.04.1990 GB 9009407
27.04.1990 US 515302
|
| (62) |
Application number of the earlier application in accordance with Art. 76 EPC: |
|
91908818.7 / 0526556 |
| (71) |
Applicants: |
|
- W.L. GORE & ASSOCIATES, INC.
Newark,
Delaware 19714-9206 (US)
- W.L. GORE & ASSOCIATES (UK) LTD
London WC2A 2JP (GB)
|
|
| (72) |
Inventor: |
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- Mortimer, William Patrick
Conowingo, MD 21918 (US)
|
| (74) |
Representative: Horner, Martin Grenville et al |
|
Cruikshank & Fairweather
19 Royal Exchange Square
Glasgow G1 3AE
Scotland
Glasgow G1 3AE
Scotland (GB) |
|
| |
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|
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Remarks: |
|
This application was filed on 22 - 09 - 1992 as a divisional application to the application
mentioned under INID code 60. |
|
| (54) |
Electrical insulating material |
(57) An electrical insulating composite material comprises an intimate admixture of
(a) 5-90 weight percent of a thermoplastic copolymer of tetrafluoroethylene and perfluoro
(propyl vinyl ether); and
(b) 90-5 weight percent of coagulated dispersion type polytetrafluoroethylene (PTFE),
or of porous expanded PTFE.
Tape made from the composite material may be porous expanded tape or non-porous tape.
The tape is wrapped around a conductor (C) and sintered at 320-450°C. A dual-wrap
construction having layers (A, B) of both porous expanded tape and of non-porous tape
give particularly good dynamic cut-through and scrape resistance properties.