Transparent Conductive Films Containing Carbon Nanotubes And Touch Panel

• US 20100040887A1
• Filed: 10/07/2008
• Published: 02/18/2010
• Est. Priority Date: 08/14/2008
• Status: Active Grant

• Current Assignee: Korea Electrotechnology Research Institute
• Original Assignee: Korea Electrotechnology Research Institute
• Inventors: Han, Joong Tark, Jeong, Hee Jin, Woo, Jong Seok, Lee, Geon Woong
• Granted Patent: US 8,741,434 B2
• Time in Patent Office: Days
• US Class Current: 428/412
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: C08K 3/34 Silicon-containing compounds
• CPC Class Codes: C08K 7/06 Elements
• CPC Class Codes: C09D 5/24 Electrically-conducting paints conductive materials H01B1/00
• CPC Class Codes: C09D 7/62 modified by treatment with other compounds
• CPC Class Codes: C09D 7/70 characterised by shape, e.g. fibres, flakes or microspheres
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• CPC Class Codes: H10K 85/221 Carbon nanotubes
• CPC Class Codes: Y10T 428/29 Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
• CPC Class Codes: Y10T 428/30 Self-sustaining carbon mass or layer with impregnant or other layer
• CPC Class Codes: Y10T 428/31504 Composite [nonstructural laminate]
• CPC Class Codes: Y10T 428/31507 Of polycarbonate

Abstract

Disclosed herein is a transparent conductive polycarbonate film coated with carbon nanotubes, including a transparent conductive layer formed by applying a mixed solution of carbon nanotubes and a binder on one side or both sides of a transparent polycarbonate film, and a touch panel using the transparent conductive polycarbonate film as a lower transparent electrode. The present invention provides a transparent conductive polycarbonate film coated with a mixed solution of carbon nanotubes and a binder, by which a touch panel having high transmissivity can be manufactured by directly forming a transparent conductive layer on a polycarbonate film used as a protective film of a liquid crystal display using carbon nanotubes, without using a polyethylene terephthalate (PET) substrate used for a transparent electrode of a conventional touch panel, by which the production cost of the touch panel can be decreased, and by which a thin touch panel can be manufactured.

Claims

1. A transparent conductive polycarbonate film coated with carbon nanotubes, comprising a transparent conductive layer formed by applying a mixed solution of carbon nanotubes and a binder on one side or both sides of a transparent polycarbonate film.

2. The transparent conductive polycarbonate film of claim 1, wherein the carbon nanotubes are selected from among single-wall carbon nanotubes, double-wall carbon nanotubes, multi-wall carbon nanotubes, and mixtures thereof.

3. The transparent conductive polycarbonate film of claim 1, wherein the transparent conductive polycarbonate film has a surface resistance of 1×

103 Ω

/sq or less and a transmissivity of 70% or more in a wavelength of 540˜

560 nm.

4. The transparent conductive polycarbonate of claim 1, wherein, in the coating of the mixed solution of the carbon nanotubes and binder, the transparent conductive polycarbonate film is provided on one side or both sides thereof with a mono-layered transparent conductive layer having a predetermined amount of the binder or a multi-layered transparent conductive layer having different amounts of the binder from each other.

5. The transparent conductive polycarbonate film of claim 4, wherein the multi-layered transparent conductive layer comprises:

a conductive layer; and

a protective layer formed on the conductive layer or an adhesive layer formed beneath the conductive layer.

6. The transparent conductive polycarbonate film of claim 5, wherein the conductive layer has a lower binder content than that of the adhesive layer or the protective layer.

7. The transparent conductive polycarbonate film of claim 5, wherein the multi-layered transparent conductive layer comprises:

an adhesive layer formed on the polycarbonate film;

a conductive layer formed on the adhesive layer; and

a protective layer formed on the conductive layer.

8. The transparent conductive polycarbonate film of claim 7,

wherein an amount of the binder included in the adhesive layer is 20˜

99.9 parts by weight based on 100 parts by weight of a mixture of the carbon nanotubes and binder,

an amount of the binder included in the conductive layer is 0.1˜

50 parts by weight based on 100 parts by weight of the mixture of the carbon nanotubes and binder, and

an amount of the binder included in the protective layer is 20˜

99.9 parts by weight based on 100 parts by weight of the mixture of the carbon nanotubes and binder.

9. The transparent conductive polycarbonate film of claim 5,

wherein the multi-layered transparent conductive layer comprises:

an adhesive layer formed on the polycarbonate film; and

a conduction-protection mixed layer, serving as both a conductive layer and a protective layer, formed on the adhesive layer.

10. The transparent conductive polycarbonate film of claim 9,

wherein an amount of the binder included in the adhesive layer is 20˜

99.9 parts by weight based on 100 parts by weight of a mixture of the carbon nanotubes and binder, and

an amount of the binder included in the conduction-protection mixed layer be 0.1˜

70 parts by weight based on 100 parts by weight of the mixture of the carbon nanotubes and binder.

11. The transparent conductive polycarbonate film of claim 5,

wherein the multi-layered transparent conductive layer comprises:

a conduction-adhesion mixed layer, serving as both a conductive layer and an adhesive layer, formed on the polycarbonate film, and

a protective layer formed on the conduction-adhesion mixed layer.

12. The transparent conductive polycarbonate film of claim 11,

wherein an amount of the binder included in the conduction-adhesion mixed layer is 0.1˜

70 parts by weight based on 100 parts by weight of a mixture of the carbon nanotubes and binder, and

an amount of the binder included in the protective layer is 20˜

99.9 parts by weight based on 100 parts by weight of the mixture of the carbon nanotubes and binder.

13. The transparent conductive polycarbonate film of claim 1, wherein the binder is one selected from among thermoplastic resins, thermosetting resins, photo-curable resins, silane compounds, titanium compounds, copolymers, self-assembled resins, conductive polymers, and combinations thereof.

14. The transparent conductive polycarbonate film of claim 1, wherein the carbon nanotube has an outer diameter of 0.5˜

15 nm.

15. A touch panel, comprising:

a protective layer for protecting a liquid crystal display screen; and

a transparent conductive film formed on the protective layer, the transparent conductive film including a lower transparent electrode, an upper transparent electrode, and a spacer interposed therebetween,

wherein the transparent conductive polycarbonate film coated with carbon nanotubes of claim 1 is used as the protective layer of the liquid crystal display screen, and simultaneously used as the lower transparent electrode.