Electrical insulating material comprising an insulating layer in the form of an organic polymer
US5061554A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 21, 1988 |
| Grant date | Oct 29, 1991 |
| Priority date | — |
| Expiry date | Mar 21, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T442/2475
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A tape-formed or sheet-formed insulating material for use in windings and coils of electrical machines includes an insulating layer in the form of a homogeneous film of an organic polymer or in the form of a felt of a paper of fibres of an organic polymer and a protective layer coated on at least one side of the insulating layer which protects the insulating layer against degradation caused by corona. The protective layer comprises an organic polymer containing at least 10 percent by volume of a powdered filler in the form of chromium oxide, iron oxide or a mixture of chromium oxide and iron oxide. The filler preferably has an intrinsic resistivity of 10.sup.4 -10.sup.8 ohm m. The thickness of the protective layer and the total thickness of the protective layer, respectively, are preferably smaller than the thickness of the insulating layer and the resistivity of the protective layer is preferably in excess of 10.sup.10 ohm m.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.