# US 11,442,201 B2 · Flexible display cover substrate

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- Number: US 11,442,201 B2
- Document ID: US11442201B2
- Status: Granted
- Kind: B2
- Application number: 16/619,089
- Filed: 2019-04-01
- Published: 2021-06-03
- Granted: 2022-09-13
- Earliest claimed: 2019-04-01
- Assignees: Microcosm Technology Co., Ltd.
- Applicants: Microcosm Technology Co., Ltd.
- Inventors: Bo-Hung Lai; Chih-Te Yen; Tang-Chieh Huang
- Web page: https://patentgrep.com/patent/US11442201B2

## CPC

- C09D 5/22: Luminous paints {(luminescent compositions C09K11/00)}
- C08F 292/00: Macromolecular compounds obtained by polymerising monomers on to inorganic materials
- C08J 7/0427: {with only one layer of a composition containing a polymer binder (with more layers C08J7/042)}
- C08J 7/046: Forming abrasion-resistant coatings; Forming surface-hardening coatings
- C08L 79/08: Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
- C09D 7/41: Organic pigments; Organic dyes
- G02B 1/14: Protective coatings, e.g. hard coatings
- G09F 9/301: {flexible foldable or roll-able electronic displays, e.g. thin LCD, OLED}
- B82Y 20/00: Nanooptics, e.g. quantum optics or photonic crystals
- B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites
- B82Y 40/00: Manufacture or treatment of nanostructures
- C08J 2379/08: Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
- C08K 5/0041: {Optical brightening agents, organic pigments}
- C08L 2201/10: Transparent films; Clear coatings; Transparent materials
- C08L 2203/16: used for films
- G02B 2207/101: Nanooptics
- G02B 2207/113: Fluorescence
- C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D)
- C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29)
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G09F: DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09)

## Abstract

A flexible display cover substrate is provided, including a transparent polyimide film and a device protective layer. The device protective layer is formed by a hard coating layer disposed on at least one side of the transparent polyimide film, and the hard coating layer is composed of three or more reactive functional group compounds, an initiator, an elastic oligomer, a nano inorganic modified particle, and a fluorescent pigment. The flexible display cover substrate of the invention, after being folded by a radius of curvature of 1 mm, does not cause cracks on the surface of the hard coating layer or break the substrate, and the yellow index YI of the flexible display cover substrate is less than 2.0.

## Claims

### Claim 1

A flexible display cover substrate, comprising:
a transparent polyimide film; and
a device protective layer formed by a hard coating layer and disposed on at least one side of the transparent polyimide film, and the hard coating layer is composed of three or ore reactive functional group compounds, an initiator, an elastic oligomer, a nano inorganic modified particle, and a fluorescent pigment,
wherein the elastic oligomer is an oligomer of carbamate(meth)acrylic acid, and is formed by reacting hydroxy(meth)acrylate and diisocyanate.

### Claim 2 (depends on 1)

The flexible display cover substrate of claim 1, wherein a yellow index YI of the flexible display cover substrate is less than 2.0.

### Claim 3 (depends on 1)

The flexible display cover substrate of claim 1, wherein the fluorescent pigment is composed of a photoluminescent material and has an absorption wavelength of 360 nm to 430 nm and an emission wavelength of 430 nm to 520 nm.

### Claim 4 (depends on 1)

The flexible display cover substrate of claim 1, wherein a Stokes shift of the fluorescent pigment is less than 150 nm.

### Claim 5 (depends on 1)

The flexible display cover substrate of claim 1, wherein the fluorescent pigment is a Coumarin series, Fluorol 7GA (2-butyl-6-(butylamino)-1H -benz[de]isoquinoline-1,3(2H)-dione), pyridine 1 (1-ethyl-2-(4-(p -dimethylaminophenyl)-1,3-butadienyl)-pyridinium perchlorat), carbazole, a fluorescent powder, or a quantum dot.

### Claim 6 (depends on 1)

The flexible display cover substrate of claim 1, wherein based on a total weight of the hard coating layer, an amount of the fluorescent pigment is 0.01 wt % to 1 wt %.

### Claim 7 (depends on 1)

The flexible display cover substrate of claim 1, wherein a thickness of the flexible display cover substrate is 50 μm to 130 μm and a total light transmittance thereof is 90% or more.

### Claim 8 (depends on 1)

The flexible display cover substrate of claim 1, wherein a thickness of the hard coating layer is 5 μm to 30 μm and a hardness thereof is 7H to 9H.

### Claim 9 (depends on 1)

The flexible display cover substrate of claim 1, wherein a thickness of the transparent polyimide film is 25 μm to 100 μm.

### Claim 10 (depends on 1)

The flexible display cover substrate of claim 1, wherein based on a total weight of the hard coating layer, amounts of the three or more reactive functional group compounds and the initiator are 10 wt % to 60 wt %.