Electrically conductive film

Patent metadata

Field	Value
Publication number	US-9468092-B2
Application number	US-201414405572-A
Country	US
Kind code	B2
Filing date	Oct 8, 2014
Priority date	Oct 10, 2013
Publication date	Oct 11, 2016
Grant date	Oct 11, 2016

Abstract

The present invention relates to an electrically conductive film characterized by being able to undergo elastic deformation, having little residual strain rate and exhibiting stress relaxation properties. More specifically, the present invention relates to an electrically conductive film wherein the stress relaxation rate (R) and the residual strain rate α, as measured in a prescribed extension-restoration test, are as follows: 20%≦R≦95% and 0%≦α≦3%.

First claim

The invention claimed is:

1. An electrically conductive film obtained by forming a metal layer having a regular mesh-like structure or an irregular random mesh-like structure on a resin substrate that is able to undergo elastic deformation,
the stress relaxation rate (R) and the residual strain rate (α), as measured in a extension-restoration test described below, satisfy the following relationships:
20%≦R≦95% and

0%≦α≦3%;

wherein in the extension-restoration test a piece of the electrically conductive film having a thickness of 50 μm and a shape of No. 6 dumbbell having a width of measured portion of 4 mm and a length of linear portion of 25 mm being subjected to an extension process and then a restoration process under the conditions described below using a tensile-compression tester in accordance with ISO 3384, and the stress relaxation rate (R) and the residual strain rate (α) being calculated using the calculation methods described below,

Extension process conditions:
deflection correction is carried out at a force of 0.05 N or lower,
Speed of testing: 25 mm/min at 0 to 25% extension;
Temperature conditions: 23° C.;
Extension/holding conditions: holding for 5 minutes at 25% extension;

Restoration process conditions:
Speed of testing: 0.1 mm/min until the tensile force reaches 0±0.05 N;
Temperature conditions: 23° C.;

Stress relaxation rate calculation method:
the tensile force being measured at the point when the extension process is complete, and this being defined as the initial tensile force (F A0 ), then the amount of strain being maintained for 5 minutes under the extension/holding conditions, after which the tensile force is measured, and this being defined as F A (t 5 ), with the stress relaxation rate (R) being calculated using the following formula:

R
=

F

A
⁢

⁢
O

-

F
A

⁡

(

t
⁢

⁢
5

)

F
AO

×
100

;

Residual strain rate calculation method:
the amount of strain being measured at the point where the tensile force in the restoration process reaches 0±0.05 N, and this being defined as the residual strain rate (α).

2. The electrically conductive film according to claim 1 , wherein the resin substrate contains at least a thermosetting resin.

3. The electrically conductive film according to claim 2 , wherein the thermosetting resin contains an epoxy resin.

4. The electrically conductive film according to claim 1 , wherein the metal layer contains at least one of gold, silver, copper, aluminum and combinations of these metals.

5. The electrically conductive film according to claim 1 , wherein in the metal layer, the area covered by metal is 5 to 80%.

6. The electrically conductive film according to claim 1 , wherein the thickness of the metal layer is 10 micrometers or lower and the minimum line width of the metal layer is 0.1 micrometers or more.

7. The electrically conductive film according to claim 1 , wherein a part or all of the metal layer is embedded in the resin substrate that is able to undergo elastic deformation.

8. The electrically conductive film according to claim 1 , which has, between the metal layer and the resin substrate layer, a resin layer having a composition that is different from the resin of the resin substrate layer.

9. The electrically conductive film according to claim 1 , which has a total light transmittance of 70% or higher.

10. A patterned electrically conductive film obtained by partially removing the metal layer in the electrically conductive film according to claim 1 .

11. A display that uses the electrically conductive film according to claim 1 .

12. A touch sensor that uses the electrically conductive film according to claim 1 .

13. A solar cell that uses the electrically conductive film according to claim 1 .

Assignees

• Panasonic Ip Man Co Ltd
• Panasonic Ip Man Co Ltd

Inventors

• Sawada Tomoaki
• Yoshioka Shingo
• Abe Takatoshi

Classifications

• C08J7/0427

  with only one layer of a composition containing a polymer binder (with more layers C08J7/042) · CPC title

• B32B15/092

  comprising epoxy resins · CPC title

• B32B2262/103

  Metal fibres · CPC title

• B32B15/08

  of synthetic resin · CPC title

• H01B1/02

  mainly consisting of metals or alloys · CPC title