Transparent conductive laminate and touch panel using the same

• US 6,689,458 B1
• Filed: 04/24/2001
• Issued: 02/10/2004
• Est. Priority Date: 08/31/1999
• Status: Expired due to Term

• Current Assignee: Teijin Limited
• Original Assignee: Teijin Limited
• Inventors: Yahata, Kazuo, Kon, Tatsuichiro, Hara, Hiroshi, Mikoshiba, Hitoshi
• Primary Examiner(s): Jones, Deborah
• Assistant Examiner(s): BOSS, WENDY L
• Application Number:
  US09/830,126
• Time in Patent Office: 1,022 Days
• Field of Search: 428/156, 428/220, 428/323, 428/327, 428/332, 428/336, 428/339, 428/402, 428/500, 428/702, 428/689, 428/333
• US Class Current: 428/339
• CPC Class Codes: B32B 27/06 as the main or only constituent of a layer, which is next to another layer of the same or of a different material next to a layer of a particular substance B32B9/045; next to a bituminous or tarry layer B32B11/046; next to a water setting substance layer B32B13/12; next to a metal layer B32B15/08; next to a glass layer B32B17/10; next to a layer formed of natural mineral fibres or particles B32B19/045; next to a wood layer B32B21/08; next to a cellulosic plastic layer B32B23/08; next to a natural or synthetic rubber layer B32B25/08
• 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: Y10T 428/24479 including variation in thickness
• CPC Class Codes: Y10T 428/25 Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 428/265 1 mil or less
• CPC Class Codes: Y10T 428/269 including synthetic resin or polymer layer or component
• CPC Class Codes: Y10T 428/2982 Particulate matter [e.g., sphere, flake, etc.]

Abstract

This invention relates to a transparent conductive laminate and to a touch panel which uses the transparent conductive laminate and has excellent durability and excellent visibility. The transparent conductive laminate contains a transparent polymer substrate and a transparent conductive layer disposed on at least one of surfaces of the transparent polymer substrate, the transparent conductive layer has a surface containing micro bumps, wherein: (1) the transparent conductive laminate contains a cross-linked polymer layer (A) containing fine particles and a cross-linked polymer layer (B) between the transparent polymer substrate and the transparent conductive layer, said cross-linked polymer layer (A) is disposed between the transparent polymer substrate and said cross-linked polymer layer (B); (2) the cross-linked polymer layer (B) contacts the transparent conductive layer; and (3) the surface of said transparent conductive layer contains the bumps having an average height of 0.3 to 1 μm and a density in the range of 350 to 1,800 bumps/mm². The transparent conductive laminate can be used as an electrode substrate to provide a touch panel which has excellent writing durability, does not generate interference fringes in the touch panel, and gives non-dim and easily readable letters on the display.

Claims

1. A transparent conductive laminate comprising a transparent polymer substrate and a transparent conductive layer disposed on at least one of sides of the transparent polymer substrate, said transparent conductive layer has a surface containing micro bumps, wherein:

(1) said transparent conductive laminate comprises a cross-linked polymer layer (A) containing fine particles and a cross-linked polymer layer (B) between the transparent polymer substrate and the transparent conductive layer, said cross-linked polymer layer (A) is disposed between the transparent polymer substrate and said cross-linked polymer layer (B);

(2) the cross-linked polymer layer (B) contacts the transparent conductive layer; and

(3) the surface of said transparent conductive layer comprises the bumps having an average height of 0.3 to 1 μ

m and a density in the range of 350 to 1,800 bumps/mm².

2. The transparent conductive laminate according to claim 1, wherein the cross-linked polymer layer (A) has a surface facing the cross-linked polymer layer (B), said surface comprises micro bumps having an average height of 0.3 to 1 μ

m and a density of 350 to 1,800 bumps/mm².

3. The transparent conductive laminate according to claim 1, wherein the cross-linked polymer layer (B) is 20 to 110 nm in thickness.

4. The transparent conductive laminate according to claim 1, wherein the cross-linked polymer layer (A) comprises a radiation-cured acrylic resin.

5. The transparent conductive laminate according to claim 1, wherein the fine particles have an average diameter of 2 to 4 μ

m.

6. The transparent conductive laminate according to claim 1, wherein the cross-linked polymer layer (B) does not contain fine particles substantially.

7. The transparent conductive laminate according to claim 1, wherein the cross-linked polymer layer (B) is obtained by hydrolyzation and condensation polymerization of a metal alkoxide.

8. The transparent conductive laminate according to claim 1, wherein the transparent polymer substrate is a film or sheet of a thermoplastic polymer.

9. The transparent conductive laminate according to claim 1, wherein the transparent conductive layer comprises mainly a metal oxide.

11. The transparent conductive laminate according to claim 1, the laminate further comprises a cross-linked polymer layer (C) disposed between the cross-linked polymer layer (A) containing fine particles and the cross-linked polymer layer (B), said cross-linked polymer layer (C) has a higher refractive index than that of the cross-linked polymer layer (B).

12. The transparent conductive laminate according to claim 11, wherein said transparent conductive layer has a surface having an average reflectance of not more than 5.5% in wavelength of 450 to 650 nm and a b* value of transmitted light being −

2 to +3, wherein said b* value is obtained based on psychometric chroma coordinates in the CIE 1976 (L*a*b*) Space according to Japan Industrial Standard No. Z8729.

13. The transparent conductive laminate according to claim 12, wherein the cross-linked polymer layer (C) has a refractive index in a range of 1.7 and +0.3 higher than the refractive index of said transparent conductive layer, and has 20 to 90 nm in thickness;

said cross-linked polymer layer (B) has 1.35 to 1.5 in refractive index and 30 to 110 nm in thickness;

said transparent conductive layer has 12 to 30 nm in thickness; and

the cross-linked polymer layer (C), the cross-linked polymer layer (B) and the transparent conductive layer have 180 to 230 nm in total of optical path length of each layer (wherein the optical path length is a value obtained by multiplying a refractive index of a layer with a thickness of the layer).

14. The transparent conductive laminate according to claim 13, wherein the cross-linked polymer layer (C) and the cross-linked polymer layer (B) are cross-linked polymer layers obtained by mainly hydrolyzation and condensation polymerization of metal alkoxides, respectively.

15. The transparent conductive laminate according to claim 12, wherein said cross-linked polymer layer (C) has a refractive index in a range of 1.7 and +0.3 higher than the refractive index of said transparent conductive layer;

said cross-linked polymer layer (B) has 1.35 to 1.5 in refractive index;

said transparent conductive layer has 12 to 30 nm in thickness; and

said polymer layer (B) has a minimum point of surface reflectance within a wavelength range between 260 and 390 nm.

16. The transparent conductive laminate according to claim 15, wherein said cross-linked polymer layer (C) and said cross-linked polymer layer (B) are cross-linked polymer layers obtained by mainly hydrolyzation and condensation polymerization of metal alkoxides, respectively.

17. A touch panel comprising two transparent electrode substrates, each of the substrates has a conductive layer at least one side of the substrate, the transparent conductive layers of the two substrates face each other, characterized in that at least one of the transparent conductive substrates is the transparent conductive laminate according to claim 1.

18. The touch panel according to claim 17, said touch panel further comprises a transparent polymer film or sheet being laminated to a side opposite to the side where the transparent conductive layer of the transparent conductive laminate is formed.

10. A transparent conductive laminate comprises a transparent polymer substrate and a transparent conductive layer, said transparent polymer substrate is a thermoplastic polymer film or sheet, said transparent conductive layer comprising mainly a metal oxide, wherein the transparent conductive layer is disposed on one of sides, and the transparent conductive layer has a surface containing micro bumps, further wherein:

(1) said transparent conductive laminate comprises, between the transparent polymer substrate and the transparent conductive layer, a radiation-cured resin layer (A1) which comprises an acrylic resin containing fine particles having an average diameter of 2 to 4 μ

m, and a cross-linked polymer layer (B1) which does not containing fine particles substantially and obtained by hydrolyzation and condensation polymerization of a metal alkoxide, said radiation-cured resin layer (A1) is disposed between said transparent polymer substrate and the cross-linked polymer layer (B1);

(2) said cross-linked polymer layer (B1) has 20 to 110 nm in thickness and contacts with the transparent conductive layer; and

(3) said transparent conductive layer has a surface containing midcro bumps having an average height of 0.3 to 1 μ

m and a density of 350 to 1,800 bumps/mm².