# US 9,437,348 B2 · Electrical insulation material

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- Number: US 9,437,348 B2
- Document ID: US9437348B2
- Status: Granted
- Kind: B2
- Application number: 13/069,679
- Filed: 2011-03-23
- Published: 2012-06-21
- Granted: 2016-09-06
- Earliest claimed: 2010-12-17
- Assignees: 3M Innovative Properties Company
- Applicants: Robert H. Turpin; David S. Stankes; Martin H. Fox; Mitchell T. Huang
- Inventors: Robert H. Turpin; David S. Stankes; Martin H. Fox; Mitchell T. Huang
- Web page: https://patentgrep.com/patent/US9437348B2

## CPC

- H01B 3/52: wood; paper; press board
- B32B 5/024: {Woven fabric}
- B32B 5/26: another layer {next to it} also being fibrous or filamentary {(relative arrangement of fibres or filaments of different layers B32B5/12)}
- B32B 19/06: next to a fibrous or filamentary layer
- D21H 13/26: Polyamides; Polyimides
- D21H 13/10: Organic non-cellulose fibres
- D21H 17/67: Water-insoluble compounds, e.g. fillers, pigments
- D21H 21/18: Reinforcing agents
- Y10T 442/608: Including strand or fiber material which is of specific structural definition
- Y10T 442/659: Including an additional nonwoven fabric
- Y10T 442/693: Including a paper layer
- 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})
- B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- D21H: PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

Provided in at least one embodiment is a nonwoven paper layer directly fused on one or both sides with a nonwoven fabric layer wherein one or both of the nonwoven paper and nonwoven fabric are electrically insulating.

## Claims

### Claim 1

An article comprising:
a nonwoven paper layer directly fused on one or both sides with a nonwoven fabric layer wherein one or both of the nonwoven paper and nonwoven fabric are electrically insulating,
wherein the nonwoven paper comprises:
about 50 wt % to about 80 wt % of an inorganic filler selected from the group consisting of kaolin clay, talc, calcium carbonate, alumina trihydrate, montmorillonite, smectite, bentonite, illite, chlorite, sepiolite, attapulgite, halloysite, vermiculite, laponite, rectorite, perlite, aluminum nitride, silicon carbide, boron nitride, and combinations thereof, and
about 3 wt % to about 10 wt % polymer latex binder, and
wherein the nonwoven fabric comprises:
about 20 wt % to about 70 wt % binder fibers, wherein the binder fibers comprise at least one of bicomponent binder fibers and undrawn binder fibers, and
about 30 wt % to about 80 wt % staple fibers, wherein the staple fibers comprise para-aramid staple fibers.

### Claim 2 (depends on 1)

The article of claim 1 having a composite part dielectric breakdown strength of greater than or equal to 150 volts/mil according to ASTM D149-09.

### Claim 3 (depends on 1)

The article of claim 1 wherein the nonwoven paper further comprises aramid fibers.

### Claim 4 (depends on 3)

The article of claim 3 wherein the aramid fibers of the nonwoven paper are one or both of para-aramid and meta-aramid fibers.

### Claim 5 (depends on 1)

The article of claim 1 wherein the nonwoven paper further comprises about 10 to about 30 wt % aramid fibers.

### Claim 6 (depends on 1)

The article of claim 1 wherein the nonwoven paper further comprises non-aramid fibers selected from the group consisting of polyphenylene sulfide, polyester, polyamides, acrylic, melamine, glass, and polyimide.

### Claim 7 (depends on 1)

The article of claim 1 wherein the polymer latex binder is selected from the group consisting of acrylic latex, styrene acrylic latex, natural rubber latex, and combinations thereof.

### Claim 8 (depends on 1)

The article of claim 1 wherein the binder fibers of the nonwoven fabric further comprise non-aramid fibers selected from the group consisting of polyphenylene sulfide, polyester, glycol-modified polyester, polyphenyl sulfone, polypropylene, and combinations thereof.

### Claim 9 (depends on 1)

The article of claim 1 wherein of the nonwoven paper layer comprises more than one sheet of nonwoven paper.

### Claim 10

The article of claiml wherein the nonwoven fabric layer comprises more than one sheet of nonwoven fabric.

### Claim 11 (depends on 1)

The article of claim 1 comprising about 49 to about 95 wt % nonwoven paper and about 5 to about 51 wt % nonwoven fabric.

### Claim 12 (depends on 1)

The article of claim 1 having one nonwoven paper layer and one nonwoven fabric layer, and comprising about 66 to about 95 wt % nonwoven paper and about 5 to about 34 wt % nonwoven fabric.

### Claim 13 (depends on 1)

The article of claim 1 having one nonwoven paper layer between two nonwoven fabric layers, and comprising about 49 to about 93 wt % nonwoven paper and about 7 to about 51 wt % nonwoven fabric.