Photoalignment material, display substrate having an alignment layer formed using the same, and to a method of manufacturing the display substrate

• US 8,597,727 B2
• Filed: 10/09/2012
• Issued: 12/03/2013
• Est. Priority Date: 05/21/2008
• Status: Expired due to Fees

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Lee, Jun-Woo, Takeshita, Fusayuki, Jeon, Baek-Kyun, Jung, Tae-Sung, Kim, Hoi-Lim, Choi, Jeong-Hye, Kim, Sung-Yi
• Primary Examiner(s): Blackwell, Gwendolyn
• Assistant Examiner(s): Zhang, Ruiyun
• Application Number:
  US13/647,752
• Publication Number:
  US 20130029443A1
• Time in Patent Office: 420 Days
• Field of Search: 428/1.1, 428/1.2, 349/123, 349/124, 349/187, 445/58, 528/345, 427/525, 427/515, 427/161, 427/487, 427/508, 430/321, 524/111, 524/112, 524/113, 524/114, 524/173, 524/233, 524/359, 252/299.4, 264/1.1, 264/1.27, 264/494, 438/30
• US Class Current: 427/162
• CPC Class Codes: C09K 19/3048 in which at least two rings are linked by a carbon chain containing carbon to carbon double bonds
• CPC Class Codes: C09K 2019/0448 the end chain group being a polymerizable end group, e.g. -Sp-P or acrylate
• CPC Class Codes: C09K 2323/00 Functional layers of liquid crystal optical display excluding electroactive liquid crystal layer characterised by chemical composition
• CPC Class Codes: C09K 2323/02 Alignment layer characterised by chemical composition
• CPC Class Codes: G02F 1/133742 for homeotropic alignment
• CPC Class Codes: G02F 1/133788 by light irradiation, e.g. linearly polarised light photo-polymerisation

Abstract

A photoalignment material includes an alignment polymer, a photoalignment additive including a compound represented by the following Chemical Formula 1 and an organic solvent.

In Chemical Formula 1, R₁ represents a cyclic compound. A and B independently represent a single bond or —(C_nH_2n)—. “n” represents an integer in a range of 1 to 12. Each —CH₂— of A and/or B may be replaced with

R₃ represents an alkyl group having 1 to 12 carbon atoms, and each —CH₂— of A and/or B may be replaced with —O—. R₄ represents

In Chemical Formula 1, each hydrogen atom excluding hydrogen atoms of R₄ may be replaced with chlorine (Cl) or fluorine (F).

Claims

1. A method of manufacturing a display substrate, the method comprising:

forming a pixel unit on a base substrate; and

coating a photoalignment material on the base substrate having the pixel unit, the photoalignment material including an alignment polymer, a photoalignment additive including a chemical compound represented by the following Chemical Formula 1 and an organic solvent;

2. The method of claim 1, wherein the cyclic compound includes one selected from the group consisting of cyclohexane, benzene, chroman, naphthalene, tetrahydrofuran and dioxane.

3. The method of claim 1, wherein the alignment polymer has a main chain including at least one selected from the group consisting of a polyimide compound, a polyamic acid compound, a polysiloxane compound, a polyvinyl cinnamate compound, a polyacrylate compound, and a polymethyl methacrylate compound.

4. The method of claim 3, wherein the alignment polymer has a photoreactive branch group coupled to the main chain and capable of having an orientation due to light.

5. The method of claim 1, wherein the forming of the pixel unit comprises:

forming a switching element on the base substrate, wherein the switching element is electrically connected to a gate line and a data line; and

forming a pixel electrode electrically connected to the switching element.

6. The method of claim 1, wherein the forming of the pixel unit comprises:

forming a plurality of color filters on the base substrate; and

forming a common electrode layer on the base substrate having the color filters.

7. The method of claim 1, further comprising:

prebaking the preliminary layer at a temperature of about 50°

C. to about 70°

C. prior to irradiating the preliminary layer.

8. The method of claim 7, further comprising:

heating the preliminary layer such that the alignment polymer chemically reacts with the photoalignment additive, subsequent to prebaking the preliminary layer and prior to irradiating the preliminary layer.

9. The method of claim 8, wherein the heating of the preliminary layer includes hard-baking the preliminary layer at a temperature from about 180°

to about 220°

.

10. The method of claim 1, wherein ultra-violet (UV) light is used for irradiating the base substrate having the preliminary layer.

11. The method of claim 10, wherein the intensity of the UV light is about 0.5 J/cm² to about 2 J/cm².