Corona-resistant resin-compatible laminates

Patent metadata

Field	Value
Publication number	US-10186353-B2
Application number	US-201615188500-A
Country	US
Kind code	B2
Filing date	Jun 21, 2016
Priority date	Jun 30, 2015
Publication date	Jan 22, 2019
Grant date	Jan 22, 2019

Abstract

Laminate structure suitable for use as electrical insulation comprising:
a) a corona-resistant layer comprising 90 to 99 weight percent uniformly distributed calcined mica and 1 to 10 weight percent aramid material, the aramid material being in the form of floc, fibrid, or mixtures thereof; b) a support layer comprising unidirectional or woven filament yarns, the support layer having a first and second face; and c) a resin-compatible layer comprising 60 to 80 weight percent uniformly distributed uncalcined mica and 20 to 40 weight percent aramid material, the aramid material being in the form of floc, fibrid, or mixtures thereof; wherein the first face of the support layer is directly bound to the corona-resistant layer and the second face of the support layer is directly bound to the resin-compatible layer; the laminate structure having a total mica content of 60 weight percent or greater.

First claim

What is claimed is:

1. A laminate structure suitable for use as electrical insulation, comprising:
a) a corona-resistant layer comprising 90 to 99 weight percent uniformly distributed calcined mica and 1 to 10 weight percent aramid material, the aramid material being in the form of floc, fibrid, or mixtures thereof, the corona-resistant layer having a basis weight of 100 to 150 grams per square meter;
b) a support layer comprising unidirectional or woven filament yarns, the support layer having a first and second face; and
c) a resin-compatible layer comprising 60 to 80 weight percent uniformly distributed uncalcined mica and 20 to 40 weight percent aramid material, the aramid material being in the form of floc, fibrid, or mixtures thereof, the resin-compatible layer having a basis weight of 10 to 50 grams per square meter;

wherein the first face of the support layer is directly bound to the corona-resistant layer and the second face of the support layer is directly bound to the resin-compatible layer;
the laminate structure having a total mica content of 60 weight percent or greater.

2. The laminate structure of claim 1 wherein the resin-compatible layer is bound to the support layer by use of an adhesive.

3. The laminate structure of claim 1 wherein the corona-resistant layer is bound to the support layer by use of an adhesive.

4. The laminate structure of claim 1 wherein all the aramid material in the corona-resistant layer is present as an aramid fibrid.

5. The laminate structure of claim 1 wherein the aramid material in each of the corona-resistant and resin-compatible layers comprises a mixture of 35-95 wt % binder and 5-65 wt % aramid floc, based on the amounts of binder and aramid floc in each layer.

6. The laminate structure of claim 5 wherein the aramid material in each of the corona-resistant and resin-compatible layers comprises a mixture of 35-75 wt % binder and 25-65 wt % aramid floc, based on the amounts of binder and aramid floc in each layer.

7. The laminate structure of claim 5 wherein the binder is an aramid fibrid.

8. The laminate structure of claim 1 wherein the filament yarns of the support layer comprise glass yarns or yarns made from thermoplastic or thermoset polymers.

9. The laminate structure of claim 8 wherein the filament yarns of the support layer comprise glass yarns.

10. The laminate structure of claim 1 wherein aramid material includes poly(meta-phenylene isophthalamide).

11. The laminate structure of claim 1 in the form of a tape having a width of 0.635 to 5.1 centimeters (0.25 to 2 inches).

12. The laminate structure of claim 1 further comprising an impregnating resin, varnish, or mixture thereof.

13. The laminate structure of claim 12 wherein the resin, varnish, or mixture thereof is partially or completely cured.

Assignees

• Du Pont

Inventors

• Kang Byoung Sam
• Lee Sang Woo

Classifications

• B32B2307/206

  Insulating · CPC title

• B32B5/024 Primary

  Woven fabric · CPC title

• B32B2262/0215

  Thermoplastic elastomer fibers · CPC title

• B32B7/12

  using interposed adhesives or interposed materials with bonding properties · CPC title

• H01B3/04

  mica · CPC title