Fiber assembly, composite of electro conductive substrate and fiber assembly, and production methods thereof

• US 8,889,573 B2
• Filed: 09/04/2009
• Issued: 11/18/2014
• Est. Priority Date: 09/04/2008
• Status: Expired due to Fees

• Current Assignee: Daiwabo Holdings Company Limited, Daiwabo Polytec Co., Ltd. (Daiwabo Holdings Company Limited)
• Original Assignee: Daiwabo Holdings Company Limited, Daiwabo Polytec Co., Ltd. (Daiwabo Holdings Company Limited)
• Inventors: Kamisasa, Toshio
• Primary Examiner(s): Steele, Jennifer A
• Application Number:
  US13/062,333
• Publication Number:
  US 20110177395A1
• Time in Patent Office: 1,901 Days
• Field of Search: 442361-364, 428/372, 428/373, 429129-147, 429247-255
• US Class Current: 442/361
• CPC Class Codes: D01D 5/0023 the material being a polymer melt
• CPC Class Codes: D01D 5/34 Core-skin structure; Spinnerette packs therefor
• CPC Class Codes: D01D 5/36 Matrix structure; Spinnerette packs therefor
• CPC Class Codes: D01F 8/06 with at least one polyolefin as constituent
• CPC Class Codes: D04H 1/728 by electro-spinning electro-spinning methods and apparatus D01D5/0007
• CPC Class Codes: D04H 3/016 characterised by the fineness
• CPC Class Codes: D04H 3/147 Composite yarns or filaments
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 4/13 Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
• CPC Class Codes: H01M 4/139 Processes of manufacture
• CPC Class Codes: H01M 4/661 Metal or alloys, e.g. alloy coatings H01M4/669 take precedence
• CPC Class Codes: H01M 50/403 Manufacturing processes of separators, membranes or diaphragms
• CPC Class Codes: H01M 50/417 Polyolefins
• CPC Class Codes: H01M 50/44 Fibrous material
• CPC Class Codes: H01M 50/46 Separators, membranes or diaphragms characterised by their combination with electrodes
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 428/2929 Bicomponent, conjugate, composite or collateral fibers or filaments [i.e., coextruded sheath-core or side-by-side type]
• CPC Class Codes: Y10T 428/2931 Fibers or filaments nonconcentric [e.g., side-by-side or eccentric, etc.]
• CPC Class Codes: 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
• CPC Class Codes: Y10T 442/638 : Side-by-side multicomponent strand or fiber material
• CPC Class Codes: Y10T 442/64 : Islands-in-sea multicomponent strand or fiber material
• CPC Class Codes: Y10T 442/641 : Sheath-core multicomponent strand or fiber material

Abstract

The present invention relates to a fiber assembly obtained by electrifying a resin in a melted state by application of voltage between a supply-side electrode and a collection-side electrode so as to extend the resin into an ultrafine composite fiber by electrospinning, and accumulating the ultrafine composite fiber, wherein the ultrafine composite fiber includes at least two polymeric components and the ultrafine composite fiber includes at least one type of composite fiber selected from a sea-island structure composite fiber and a core-sheath structure composite fiber as viewed in fiber cross section, at least one selected from an island component and a core component has a volume specific resistance of 10¹⁵Ω·cm or less, and at least one selected from a sea component and a sheath component has a volume specific resistance exceeding 10¹⁵Ω·cm. Thereby, the present invention provides a fiber assembly obtained by accumulating an ultrafine composite fiber obtained by electrospinning without the use of any solvent or water as a spinning solution, a composite of an electro conductive substrate and such a fiber assembly, and production methods thereof.

Claims

1. A fiber assembly comprising an ultrafine composite fiber,

wherein the fiber assembly is obtained by electrifying a resin in a melted state by application of voltage between a supply-side electrode and a collection-side electrode so as to extend the resin into the ultrafine composite fiber by electrospinning, and accumulating the ultrafine composite fiber,

the ultrafine composite fiber comprises at least two polymeric components,

the ultrafine composite fiber comprises at least one type of a composite fiber selected from the group consisting of a sea-island structure composite fiber and a core-sheath structure composite fiber, as viewed in fiber cross section,

at least one component selected from an island component in the sea-island structure composite fiber and a core component in the core-sheath structure composite fiber has a volume specific resistance of 10¹⁵Ω

·

cm or less,

at least one component selected from a sea component in the sea-island structure composite fiber and a sheath component in the core-sheath structure composite fiber has a volume specific resistance exceeding 10¹⁵Ω

·

cm,

the at least one component selected from the core component and the island component is an ethylene-vinyl alcohol copolymer,

the at least one component selected from the sheath component and the sea component is a polyolefin,

the ultrafine composite fiber has a fiber diameter of 5 μ

m or less, and

the fiber assembly is formed in a sheet form in which portions of the ultrafine composite fibers are thermally bonded to each other by thermal adhesion of the at least one component selected from the sea component and the sheath component.

2. The fiber assembly according to claim 1,

wherein a polymer of the at least one component selected from the sea component and the sheath component has a melting point lower than a melting point of a polymer of the at least one component selected from the island component and the core component, by at least 10°

C.

3. The fiber assembly according to claim 1,

wherein the polymer of the at least one component selected from the island component and the core component has a melting point ranging from 100 to 300°

C., and

the polymer of the at least one component selected from the sea component and the sheath component has a melting point ranging from 70 to 180°

C.

4. The fiber assembly according to claim 1,

wherein the fiber assembly contains neither a solvent nor water except in an unavoidable amount.

14. The fiber assembly according to claim 1,

wherein the ultrafine composite fiber has a fiber diameter of 3 μ

m or less.

5. A composite of an electro conductive substrate and a fiber assembly comprising:

an electro conductive substrate; and

a fiber assembly,

wherein the fiber assembly is obtained by electrifying a resin in a melted state by application of voltage between a supply-side electrode and a collection-side electrode so as to extend the resin into an ultrafine composite fiber by electrospinning, and accumulating the ultrafine composite fiber,

the ultrafine composite fiber comprises at least two polymeric components,

the ultrafine composite fiber comprises at least one type of composite fiber selected from the group consisting of a sea-island structure composite fiber and a core-sheath structure composite fiber, as viewed in fiber cross section,

at least one component selected from an island component in the sea-island structure composite fiber and a core component in the core-sheath structure composite fiber has volume specific resistance of 10¹⁵Ω

·

cm or less,

at least one component selected from a sea component in the sea-island structure composite fiber and a sheath component in the core-sheath structure composite fiber has volume specific resistance exceeding 10¹⁵Ω

·

cm,

the at least one component selected from the core component and the island component is an ethylene-vinyl alcohol copolymer, and

the at least one component selected from the sheath component and the sea component is a polyolefin

the ultrafine composite fiber has a fiber diameter of 5 μ

m or less,

the fiber assembly is formed in a sheet form in which portions of the ultrafine composite fibers are thermally bonded to each other by thermal adhesion of the at least one component selected from the sea component and the sheath component, and

at least a part or all of a surface of the electro conductive substrate is covered and integrated with the fiber assembly.

6. The composite of the electro conductive substrate and the fiber assembly according to claim 5,

wherein the ultrafine composite fiber is partially embedded in the surface of the electro conductive substrate.

7. The composite of the electro conductive substrate and the fiber assembly according to claim 5,

wherein the electro conductive substrate is a battery electrode, and the fiber assembly is a battery separator.

11. The composite of an electro conductive substrate and a fiber assembly according to claim 5,

wherein a polymer of the at least one component selected from the sea component and the sheath component has a melting point lower than a melting point of a polymer of the at least one component selected from the island component and the core component, by at least 10°

C.

12. The composite of an electro conductive substrate and a fiber assembly according to claim 5,

wherein a polymer of the at least one component selected from the island component and the core component has a melting point ranging from 100 to 300°

C., and

a polymer of the at least one selected from the sea component and the sheath component has a melting point ranging from 70 to 180°

C.

13. The composite of an electro conductive substrate and a fiber assembly according to claim 5,

wherein the fiber assembly contains neither a solvent nor water except in an unavoidable amount.

15. The composite of the electro conductive substrate and the fiber assembly according to claim 5,

wherein the ultrafine composite fiber has a fiber diameter of 3 μ

m or less.

8. A method for producing a fiber assembly comprising steps of:

heating and melting a composite-resin-formed product in a solid state or a melted state in at least one region selected from the group consisting of a region in advance of a supply-side electrode and a region between the supply-side electrode and a collection-side electrode;

extending the composite-resin-formed product into an ultrafine composite fiber by electrospinning; and

accumulating the ultrafine composite fiber,

wherein the ultrafine composite fiber comprises at least two polymeric components,

the ultrafine composite fiber comprises at least one type of a composite fiber selected from the group consisting of a sea-island structure composite fiber and a core-sheath structure composite fiber, as viewed in fiber cross section,

at least one selected from an island component in the sea-island structure composite fiber and a core component in the core-sheath structure composite fiber has volume specific resistance of 10¹⁵Ω

·

cm or less,

at least one selected from a sea component in the sea-island structure composite fiber and a sheath component in the core-sheath structure composite fiber has volume specific resistance exceeding 10¹⁵Ω

·

cm,

the at least one component selected from the core component and the island component is an ethylene-vinyl alcohol copolymer,

the at least one component selected from the sheath component and the sea component is a polyolefin,

the ultrafine composite fiber has a fiber diameter of 5 μ

m or less, and

the fiber assembly is formed in a sheet form in which portions of the ultrafine composite fibers are thermally bonded to each other by thermal adhesion of the at least one component selected from the sea component and the sheath component.

9. The method for producing a fiber assembly according to claim 8,

wherein the composite-resin-formed product in the solid state or the melted state comprises at least two polymeric components,

the composite-resin-formed product in the solid or the melted state comprises at least one type of composite fiber selected from a sea-island structure composite fiber and a core-sheath structure composite fiber, as viewed in fiber cross section,

at least one component selected from an island component in the sea-island structure composite fiber and a core component in the core-sheath structure composite fiber has volume specific resistance of 10¹⁵Ω

·

cm or less, and

at least one component selected from a sea component in the sea-island structure composite fiber and a sheath component in the core-sheath structure composite fiber has volume specific resistance exceeding 10¹⁵Ω

·

cm.

16. The method for producing the fiber assembly according to claim 8,

wherein the ultrafine composite fiber has a fiber diameter of 3 μ

m or less.

10. A method for producing a composite of an electro conductive substrate and a fiber assembly in which at least a part or all of a surface of the electro conductive substrate is covered and integrated with the fiber assembly, comprising:

depositing the electro conductive substrate on a collection-side electrode;

heating and melting a composite-resin-formed product in a solid state or a melted state in at least one region selected from the group consisting of a region in advance of a supply-side electrode and a region between the supply-side electrode and the collection-side electrode;

extending the composite-resin-formed product into an ultrafine composite fiber by electrospinning; and

accumulating the ultrafine composite fiber on the surface of the electro conductive substrate so as to form a fiber assembly in which the electro conductive substrate is covered and integrated with the fiber assembly,

wherein the ultrafine composite fiber comprises at least two polymeric components,

the ultrafine composite fiber comprises at least one type of composite fiber selected from a sea-island structure composite fiber and a core-sheath structure composite fiber, as viewed in fiber cross section,

at least one component selected from an island component in the sea-island structure composite fiber and a core component in the core-sheath structure composite fiber has volume specific resistance of 10¹⁵Ω

·

cm or less,

at least one component selected from a sea component in the sea-island structure composite fiber and a sheath component in the core-sheath structure composite fiber has volume specific resistance exceeding 10¹⁵Ω

·

cm,

the at least one component selected from the core component and the island component is an ethylene-vinyl alcohol copolymer,

the at least one component selected from the sheath component and the sea component is a polyolefin,

the ultrafine composite fiber has a fiber diameter of 5 μ

m or less, and

the fiber assembly is formed in a sheet form in which portions of the ultrafine composite fibers are thermally bonded to each other by thermal adhesion of the at least one component selected from the sea component and the sheath component.

17. The method for producing the composite of the electro conductive substrate and the fiber assembly according to claim 10,

wherein the ultrafine composite fiber has a fiber diameter of 3 μ

m or less.