Antistatic polyimide-based film and flexible display panel using same

Patent metadata

Field	Value
Publication number	US-11518921-B2
Application number	US-202017034702-A
Country	US
Kind code	B2
Filing date	Sep 28, 2020
Priority date	Sep 30, 2019
Publication date	Dec 6, 2022
Grant date	Dec 6, 2022

Abstract

Provided is an antistatic polyimide-based film. More particularly, as an antistatic polyimide-based film for a window cover for protecting a surface of a display device, a window cover film having a protective film formed on the polyimide-based film provides an improvement to a problem of not being used as a film for a display window cover because a portion of the protective film remains on a base layer or a hard coating layer without being peeled off due to static electricity in the protective film or the base layer, or a hard coating layer, or the hard coating layer is peeled off with some or all of the protective film when the protective film is peeled off.

First claim

What is claimed is:

1. An antistatic polyimide-based film comprising:
a polyimide-based base layer; and
an antistatic layer formed on one or both surfaces of the base layer and having a surface resistance of 10 7 Ω/□ or more,
wherein the antistatic polyimide-based film has a total light transmittance of 89% or more, a haze of 1.2% or less, a yellow index of 3.0 or less, and a b* value of 1.5 or less.

2. The antistatic polyimide-based film of claim 1 , wherein the antistatic polyimide-based film has a surface resistance change of 1×10 3 or less, as measured according to the following Equation 1, after being maintained at 150° C. for 10 minutes.
Surface Resistance Change=Surface Resistance after Heat Treatment/Surface Resistance before Heat Treatment  [Equation 1]

3. The antistatic polyimide-based film of claim 1 , wherein the antistatic layer comprises modified carbon nanotubes surface-treated with an inorganic acid, and an organic-inorganic binder resin.

4. The antistatic polyimide-based film of claim 3 , wherein the antistatic layer comprises 0.01 to 5 parts by weight of the modified carbon nanotubes surface-treated with the inorganic acid, based on 100 parts by weight of the organic-inorganic binder resin.

5. The antistatic polyimide-based film of claim 3 , wherein the organic-inorganic binder resin is derived from any one or two or more inorganic precursors selected from tetraalkoxysilane, trialkoxysilane, dialkoxysilane, monoalkoxysilane, and colloid silica; and
any one or two or more silane coupling agents selected from vinyl trichlorosilane, vinyltris(β-methoxyethoxy)silane, vinyl triethoxysilane, vinyl trimethoxysilane, 3-methacryloxypropyl-trimethoxysilane, β-(3,4-epoxycyclohexyl)-ethyltrimethoxysilane, γ-glycidoxypropyl-trimethoxysilane, glycidoxypropyl-trimethoxysilane, γ-glycidoxypropyl-methylidiethoxysilane, N-β-(aminoethyl)-γ-aminopropyl-trimethoxysilane, N-β-(aminoethyl)-γ-aminopropyl-methyldimethoxysilane, 3-aminopropyl-triethoxysilane, N-phenyl-γ-aminopropyl-trimethoxysilane, and γ-mercaptopropyl-trimethoxysilane.

6. The antistatic polyimide-based film of claim 1 , wherein the base layer has a modulus of 3 GPa or more and a break elongation of 8% or more, as measured according to ASTM D882, has a light transmittance of 5% or more, as measured at 388 nm according to ASTM D1746, and has a total light transmittance of 87% or more, as measured at 400 to 700 nm, a haze of 2.0% or less, a yellow index of 5.0 or less, and a b* value of 2.0 or less.

7. The antistatic polyimide-based film of claim 1 , wherein the base layer has a polyamide-imide structure.

8. The antistatic polyimide-based film of claim 7 , wherein the base layer comprises a unit derived from a fluorine-based aromatic diamine, a unit derived from an aromatic dianhydride, a unit derived from an alicyclic dianhydride, and a unit derived from an aromatic diacid dichloride.

9. The antistatic polyimide-based film of claim 1 , wherein the base layer has a thickness of 10 to 500 μm, and the antistatic layer has a thickness of 1 nm to 1 μm.

10. A window cover film comprising:
the antistatic polyimide-based film of claim 1 ; and
a coating layer formed between a base layer and an antistatic layer of the antistatic polyimide-based film or formed on a back surface of the antistatic layer or the antistatic layer.

11. The window cover film of claim 10 , wherein the coating layer comprises any one or more selected from a hard coating layer, an anti-fingerprint layer, an anti-fouling layer, an anti-scratch layer, a low-refractive index layer, an anti-reflective layer, and an impact absorption layer.

12. A flexible display panel comprising the antistatic polyimide-based film of claim 1 .

Assignees

• Sk Innovation Co Ltd
• Sk Ie Tech Co Ltd

Inventors

• Ahn Jong Nam
• Kim Hye Jin

Classifications

• C08G73/14

  Polyamide-imides · CPC title

• C08J7/046

  Forming abrasion-resistant coatings; Forming surface-hardening coatings · CPC title

• C09D7/62

  modified by treatment with other compounds · CPC title

• C08J7/044 Primary

  Forming conductive coatings; Forming coatings having anti-static properties · CPC title

• C08J2379/08

  Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors · CPC title