# US 5,700,573 A · Flexible biregional carbonaceous fiber, articles made from biregional carbonaceous fibers, and method of manufacture

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 5,700,573 A
- Document ID: US5700573A
- Status: Granted
- Kind: A
- Application number: 08/428,691
- Filed: 1995-04-25
- Granted: 1997-12-23
- Earliest claimed: 1995-04-25
- Inventors: Francis Patrick McCullough
- Web page: https://patentgrep.com/patent/US5700573A

## CPC

- H01M 4/587: for inserting or intercalating light metals
- D01F 8/08: with at least one polyacrylonitrile as constituent
- D01F 9/12: Carbon filaments; Apparatus specially adapted for the manufacture thereof
- D01F 11/14: with organic compounds, e.g. macromolecular compounds
- H01M 4/13: Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M 4/625: {Carbon or graphite}
- H01M 4/663: {containing carbon or carbonaceous materials as conductive part, e.g. graphite, carbon fibres}
- H01M 4/667: {in the form of layers, e.g. coatings}
- H01M 4/806: {Nonwoven fibrous fabric containing only fibres}
- H01M 4/38: of elements or alloys
- H01M 4/485: of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence)
- H01M 4/668: {Composites of electroconductive material and synthetic resins}
- H01M 4/70: characterised by shape or form
- H01M 6/48: with bipolar electrodes
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- H01M 2004/029: {Bipolar electrodes}
- H01M 2300/0025: Organic electrolyte
- Y02E 60/10: Energy storage using batteries
- Y10T 428/29: Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
- Y10T 428/2913: Rod, strand, filament or fiber
- Y10T 428/2918: including free carbon or carbide or therewith [not as steel]
- Y10T 428/2924: Composite
- Y10T 428/2933: Coated or with bond, impregnation or core
- Y10T 428/2967: Synthetic resin or polymer
- Y10T 428/2973: Particular cross section
- Y10T 428/30: Self-sustaining carbon mass or layer with impregnant or other layer
- Y10T 442/2803: Polymeric coating or impregnation from a silane or siloxane not specified as lubricant or water repellent
- Y10T 442/3683: Fabric layer contains carbon or carbonaceous strand material
- Y10T 442/629: Composite strand or fiber material
- Y10T 442/637: Including strand or fiber material which is a monofilament composed of two or more polymeric materials in physically distinct relationship [e.g., sheath-core, side-by-side, islands-in-sea, fibrils-in-matrix, etc.] or composed of physical blend of chemically different polymeric materials or a physical blend of a polymeric material and a filler material
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- D01F: CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A novel flexible biregional carbonaceous fiber is disclosed comprising an inner core region of a thermoplastic polymeric material and an outer region of a carbonaceous sheath. The flexible biregional carbonaceous fibers are particularly characterized by having a ratio of the radius of the core region with respect to the total radius of the fiber (r:R) of from about 1:4 to about 1:1.05, a density of from about 1.45 to about 1.87 g/cm.sup.3, and a bending strain value of from greater than 0.01 to less than 50%. In a further embodiment of the invention, a biregional precursor fiber is disclosed having an inner core region of a thermoplastic polymeric material and an outer sheath region of a oxidation stabilized, thermoset polymeric material. The oxidation stabilized precursor fiber is characterized by having a density of from about 1.20 to about 1.32 g/cm.sup.3 The invention further resides in methods of making the biregional fibers. Preferred end uses for the biregional fibers are disclosed including thermal insulation; flame resistant and fire blocking insulation; blends of the biregional carbonaceous fibers with other natural or polymeric fibers; coated fibers, composites composed of a polymeric matrix reinforced with the biregional carbonaceous fibers of the invention, electron conductive fibers for battery electrodes, and the like.

## Claims

### Claim 1

A biregional carbonaceous fiber derived from a single homogeneous polymeric precursor fiber, wherein said biregional carbonaceous fiber comprises an inner core region of a thermoplastic polymeric material and a surrounding outer sheath region of a carbonaceous material, and wherein said inner core region and said outer sheath do not present an intermediate zone between the regions.

### Claim 2 (depends on 1)

The fiber of claim 1, having a density of from about 1.45 to about 1.87 g/cm.sup.3.

### Claim 3

The fiber of claim. 1, wherein the ratio (r:R) of the radius of the inner core region (r) with respect to the total radius of the fiber (R) is from about 1:4 to about 1:1.105.

### Claim 4 (depends on 1)

The fiber of claim 1, wherein the ratio (r:R) of the radius of the inner core region (r) with respect to the total radius of the fiber (R) is from about 1:3 to about 1:1.125.

### Claim 5 (depends on 1)

The fiber of claim 1, wherein said carbonized outer sheath region is electrically non-conductive, has a carbon content of greater than 68% but less than 85% by weight, and a bulk resistivity of from about 10.sup.8 to about 10.sup.2 ohm-cm.

### Claim 6 (depends on 1)

The fiber of claim 1, wherein said carbonized outer sheath region has electrostatic dissipating characteristics, a carbon content of greater than 68% but less than 85% by weight, and a bulk resistivity of from about 10.sup.3 to about 10.sup.0 ohm-cm.

### Claim 7 (depends on 1)

The fiber of claim 1, wherein said carbonized outer sheath region is electrically conductive, has a carbon content of greater than 85% by weight, and a bulk resistivity of less than 10.sup.0 ohm-cm.

### Claim 8 (depends on 1)

The fiber of claim 1, wherein said carbonized outer sheath region is graphitic and electrically conductive, has a carbon content of greater than 92% by weight, and a bulk resistivity of less than 10.sup.-2 ohm-cm.

### Claim 9 (depends on 1)

The fiber of claim 1, wherein said fiber is flexible and has a bending strain value of from greater than 0.01 to less than 50%, and a Young's modulus of from greater than 0.3 MM psi (2.0 GPa) to 50 MM psi (345 GPa).

### Claim 10 (depends on 1)

The fiber of claim 1, wherein said fiber is crimped and has an elongatability to break of from about 2 to about 12%, and a reversible deflection ratio of greater than 1:1.

### Claim 11 (depends on 1)

The fiber of claim 1, having a generally circular, non-circular, flat, or tubular cross-sectional shape, and a diameter of from about 1 micrometer to about 30 micrometers.