Ultraviolet curable black ink composition for foldable display and bezel pattern forming method using same

Patent metadata

Field	Value
Publication number	US-10858525-B2
Application number	US-201816492811-A
Country	US
Kind code	B2
Filing date	Dec 11, 2018
Priority date	Dec 14, 2017
Publication date	Dec 8, 2020
Grant date	Dec 8, 2020

Abstract

An ultraviolet curable black ink composition, a bezel pattern forming method using the same, a bezel pattern produced by the method, and a display substrate including the bezel pattern; are disclosed herein. In some embodiments, an ultraviolet curable ink composition includes a black pigment, a dispersant, an epoxy compound, an oxetane compound, a light diffusing agent, a photopolymerization initiator, and an organic solvent. The ultraviolet curable black ink composition is developed to be applied to a cover window film of a foldable display, has excellent light shielding properties and folding properties at a thin thickness, and as a light diffusing agent is applied to the ink, prevents surface wrinkles from generating due to a difference in the curing rate of the upper and power portions of a bezel, by means of UV curing alone without a pretreatment process.

First claim

What is claimed is:

1. An ultraviolet curable ink composition for forming a black bezel pattern, comprising:
a black pigment;
a dispersant;
an epoxy compound;
an oxetane compound;
a light diffusing agent selected from the group consisting of TiO 2 , Al 2 O 3 and a combination thereof;
a photopolymerization initiator; and
an organic solvent wherein the black pigment is present in an amount of 18 to 25% by weight based on the total weight of the ultraviolet curable ink composition.

2. The ultraviolet curable ink composition according to claim 1 , wherein the organic solvent has a boiling point of 200° C. or higher and a viscosity of 1 cP to 5 cP at 25° C.

3. The ultraviolet curable ink composition according to claim 1 , wherein the photopolymerization initiator is 10-[1,1′-biphenyl]-4-yl-2-(1-methylethyl)-9-oxo-9H-thioxanthenium hexafluorophosphate.

4. The ultraviolet curable ink composition according to claim 1 , wherein the organic solvent is present in an amount of 20 to 40% by weight based on the total weight of the ultraviolet curable ink composition.

5. The ultraviolet curable ink composition according to claim 1 , wherein the composition has a viscosity of 1 cP to 50 cP at 25° C., and wherein the adhesive force to a substrate of the composition after curing is 4B or more as measured by ASTM D3002 or D3359 in a cross-cut test.

6. The ultraviolet curable ink composition according to claim 1 , wherein the composition has a curing dose of 1000 to 10,000 mJ/cm 2 and is cured by absorbing ultraviolet radiation in a wavelength range of 250 nm to 410 nm.

7. A method of forming a bezel pattern, comprising:
inkjet printing the ultraviolet curable ink composition of claim 1 on a substrate in the form of a bezel pattern; and
irradiating the printed ultraviolet curable ink composition with ultraviolet radiation to cure the bezel pattern.

8. The method of forming a bezel pattern according to claim 7 , wherein the thickness of the cured bezel pattern is 2 to 4 μm.

9. A bezel pattern produced by patterning and curing the ultraviolet curable ink composition of claim 1 .

10. A display substrate comprising the bezel pattern of claim 9 .

11. The ultraviolet curable ink composition according to claim 1 , wherein the light diffusing agent is present in an amount of 5 to 10% by weight based on the total weight of the ultraviolet curable ink composition.

Assignees

• Lg Chemical Ltd

Inventors

• Yoo Jaehyun
• Park Sungeun
• Kim Areum
• Kim Joonhyung

Classifications

• C09D11/38

  characterised by non-macromolecular additives other than solvents, pigments or dyes · CPC title

• C09D11/322

  Pigment inks · CPC title

• C09D11/101 Primary

  Inks specially adapted for printing processes involving curing by wave energy or particle radiation, e.g. with UV-curing following the printing · CPC title

• C09D11/037

  characterised by the pigment · CPC title

• C09D11/03

  characterised by features other than the chemical nature of the binder · CPC title