Composition for forming film having wrinkle structure and method of forming the film

Patent metadata

Field	Value
Publication number	US-2016159686-A1
Application number	US-201514822417-A
Country	US
Kind code	A1
Filing date	Aug 10, 2015
Priority date	Dec 4, 2014
Publication date	Jun 9, 2016
Grant date	—

Abstract

A composition for forming film having wrinkle structure and a method of forming the film are disclosed. The composition includes photo-curable agent and photoinitiator dissolved in the photo-curable agent. The cut off wavelength of light transmittance of the photo-curable agent is greater than the cut off wavelength of light absorbance of the photoinitiator. Photo-cured thin film is formed at the upper portion of composition layer at an initial time period of irradiation. By subsequent contraction, the photo-cured thin film forms wrinkles. The wrinkle structure is controlled by the relation of the cut off wavelength of light transmittance of the photo-curable agent and the cut off wavelength of light absorbance of the photoinitiator, the photo-curing rate of the composition and the thickness of the composition layer, and the photoinitiator concentration, etc., before photo-curing. The film may increase the emission efficiency of LED and OLED and the sensing effect of sensor.

First claim

What is claimed is:

1 . A composition for forming a film having a wrinkle structure, comprising:
a first photo-curable agent and a first photoinitiator dissolved in the first photo-curable agent, a first cut off wavelength of light transmittance of the first photo-curable agent being greater than a first cut off wavelength of light absorbance of the first photoinitiator, the first cut off wavelength of light transmittance being the longest light wavelength of wavelengths having less than or equal to about 1.0% of light transmittance when light is irradiated to the first photo-curable agent layer with a thickness of about 1 mm, and the first cut off wavelength of light absorbance being the shortest light wavelength of wavelengths having less than or equal to about 0.05 of light absorbance when light is irradiated to a diluted solution layer, about 10 mm in thickness, of the first photoinitiator with about 1.0×10 −4 mol %.

2 . The composition of claim 1 , wherein the first cut off wavelength of light transmittance of the first photo-curable agent and the first cut off wavelength of light absorbance of the first photoinitiator are from about 250 nm to about 350 nm.

3 . The composition of claim 1 , wherein the first photo-curable agent has a liquid phase with a viscosity from about 1 cP to about 10 7 cP at 25° C.

4 . The composition of claim 1 , wherein a concentration of the first photoinitiator is from about 0.01 wt % to about 10 wt % with respect to a total amount of the composition.

5 . The composition of claim 1 , wherein the first photo-curable agent chemically comprises at least two substituted or unsubstituted styrene groups in a molecule thereof.

6 . The composition of claim 1 , further comprising a second photo-curable agent,
the second photo-curable agent having a second cut off wavelength of light transmittance smaller than the first cut off wavelength of light absorbance of the first photoinitiator, and an amount of the second photo-curable agent being from about 1 wt % to about 70 wt % with respect to an total amount of photo-curable agents.

7 . The composition of claim 6 , wherein the second photo-curable agent comprises at least two substituted or unsubstituted acryl groups in a molecule thereof.

8 . The composition of claim 1 , further comprising a third photo-curable agent,
the third photo-curable agent having a solid phase, and an amount of the third photo-curable agent being from about 1 wt % to about 70 wt % with respect to an total amount of photo-curable agents.

9 . The composition of claim 1 , wherein the first photoinitiator comprises at least one selected from the group consisting of Irgacure 184, Irgacure 651, Irgacure 754, Irgacure 2959, Darocur 1173 and Darocur MBF.

10 . The composition of claim 1 , further comprising a second photoinitiator dissolved in the first photo-curable agent,
the second photoinitiator having a second cut off wavelength of light absorbance greater than the first cut off wavelength of light transmittance of the first photo-curable agent, and an amount of the second photoinitiator being from about 0.1 wt % to about 50 wt % with respect to an total amount of photo initiators.

11 . The composition of claim 10 , wherein the second photoinitiator comprises at least one selected from the group consisting of Darocur TPO, Irgacure 369, Irgacure 907, Irgacure 819, Irgacure 2100, Irgacure 784, Irgacure 250, Irgacure 184, Irgacure 651, Irgacure 754, Irgacure 2959, Darocur 1173 and Darocur MBF.

12 . The composition of claim 1 , further comprising a monomer diluting the first photo-curable agent and functioning as a chain extender to further increase the molecular weight during cross-linking the first photo-curable agent,
the monomer comprising at least one selected from the group consisting of 2,3,4,5,6-pentafluorostyrene, methyl methacrylate, methyl acrylate, trifluoroacetic acid allyl ester, trifluoroacetic acid vinyl ester, 2,2,2-trifluoroethyl methacrylate, acrylic acid 1,1,1,3,3,3-hexafluoroisopropyl ester, methacrylic acid 1,1,1,3,3,3-hexafluoroisopropyl ester, 1-pentafluorophenyl-pyrrole-2,5-dione, N-methyl maleimide, N-ethyl maleimide, N-propyl maleimide, N-butyl maleimide, N-tert-butyl maleimide, N-pentyl maleimide and N-hexyl maleimide.

13 . The composition of claim 1 , further comprising a solvent diluting the first photo-curable agent,
the solvent comprising at least one selected from the group consisting of cyclopentanone, cyclohexanone, γ-butyrolactone, toluene, methanol, ethanol, propanol, ethyl ether, N,N-dimethyl acetamide, N-methyl pyrrolidinone, tetrahydrofuran, ethyl acetate and hexane.

14 . A method of forming a film, comprising:
providing a composition comprising a photo-curable agent and a photoinitiator dissolved in the photo-curable agent to form a composition layer on a substrate; and curing the composition layer to form a film having an randomly ordered wrinkle structure, the photoinitiator having a cut off wavelength of light absorbance less than or equal to about 310 nm, the cut off wavelength of light absorbance being the smallest light wavelength of wavelengths having light absorbance of less than or equal to about 0.05 when light is irradiated to a diluted solution layer, about 10 nm in thickness, with about 1.0×10 −4 mol % of the photoinitiator.

15 . The method for forming a film of claim 14 , wherein the curing of the composition layer comprises irradiating ultraviolet rays to the composition layer.

16 . The method for forming a film of claim 14 , wherein the photoinitiator comprises at least one selected from the group consisting of Irgacure 184, Irgacure 651, Irgacure 754, Irgacure 2959, Darocur 1173 and Darocur MBF.

17 . The method for forming a film of claim 14 , wherein an apparent first order photo-curing rate constant (k app ) during curing the composition layer is from about 0.01 to about 5.0 sec −1 .

18 . The method for forming a film of claim 14 , further comprising controlling the thickness of the composition layer to from about 0.1 μm to about 1000 μm to control the size of the wrinkle structure.

19 . The method for forming a film of claim 15 , wherein a wavelength range of the ultraviolet rays is from about 200 nm to about 500 nm.

20 . The method for forming a film of claim 15 , wherein the irradiating of the ultraviolet rays is conducted under an inert gas or under vacuum for from about 1 to about 30 min.

Assignees

• Korea Electronics Telecomm

Inventors

• Park Seung Koo
• Moon Jaehyun
• Lee Jeong Ik
• Yu Byoung Gon
• Lee Jonghee
• Joo Chul Woong
• Cho Doo-Hee
• Han Jun-Han

Classifications

• C03C2217/77

  Coatings having a rough surface · CPC title

• C03C2218/116

  by spin-coating, centrifugation · CPC title

• C03C2218/32

  After-treatment · CPC title

• C03C17/32 Primary

  with synthetic or natural resins (C03C17/30 takes precedence) · CPC title

• C03C17/3405

  with at least two coatings of organic materials (C03C17/36, C03C17/42 take precedence) · CPC title