CN-121995672-A - Method for producing liquid crystal alignment film, method for repairing defect in liquid crystal alignment film, method for producing liquid crystal device, and photo-alignment agent for repairing

Abstract

The invention provides a method for manufacturing a liquid crystal alignment film, a method for repairing defects of the liquid crystal alignment film, a method for manufacturing a liquid crystal device, and a photo-alignment agent for repairing, which can repair defects existing in the liquid crystal alignment film simply and accurately, and can obtain the liquid crystal device with sufficiently suppressed display defects. The liquid crystal alignment film is produced by a method comprising a film formation step of forming a liquid crystal alignment film by applying a liquid crystal alignment agent to a substrate, a detection step of detecting defects present in the liquid crystal alignment film, a coating step of partially coating a repair photo-alignment agent on a region including the defects in the liquid crystal alignment film when the defects are detected by the detection step, and an irradiation step of irradiating a region including the application site of the repair photo-alignment agent with radiation.

Inventors

• WANG DAOHAI
• UESAKA HIROSUKE

Assignees

• JSR株式会社

Dates

Publication Date

20260508

Application Date

20250912

Priority Date

20241106

Claims (7)

1. 1. A method for manufacturing a liquid crystal alignment film, comprising: a film forming step of forming a liquid crystal alignment film by applying a liquid crystal alignment agent to a substrate; a detection step of detecting a defect existing in the liquid crystal alignment film; a coating step of partially coating a repair photo-alignment agent on a region including the defect in the liquid crystal alignment film when the defect is detected by the detection step, and And an irradiation step of irradiating a region including the application site of the repair photo-alignment agent with radiation.
2. 2. The method for producing a liquid crystal alignment film according to claim 1, wherein the repair photo-alignment agent contains a compound having a photo-alignment site and a solvent.
3. 3. The method for producing a liquid crystal alignment film according to claim 2, further comprising a heat imparting step of imparting heat to the photo-alignment agent for repair applied to the region including the defect by the applying step.
4. 4. The method for producing a liquid crystal alignment film according to claim 1, further comprising a removing step of partially removing a region of the liquid crystal alignment film containing the defect before the repairing photo-alignment agent is applied by the applying step, in a case where the defect is detected by the detecting step.
5. 5. A defect repair method of a liquid crystal alignment film, comprising: A preparation step of preparing a substrate on which a liquid crystal alignment film is formed; a detection step of detecting a defect existing in the liquid crystal alignment film; a coating step of partially coating a repair photo-alignment agent on a region including the defect in the liquid crystal alignment film when the defect is detected by the detection step, and And an irradiation step of irradiating a region including the application site of the repair photo-alignment agent with radiation.
6. 6. A method for manufacturing a liquid crystal device, comprising the liquid crystal alignment film manufactured by the method for manufacturing a liquid crystal alignment film according to any one of claims 1 to 4 or the liquid crystal alignment film repaired by the method for repairing a defect of a liquid crystal alignment film according to claim 5.
7. 7. A repair photo-alignment agent for partially forming a repair film in a region including a defect existing in a liquid crystal alignment film formed on a substrate in the liquid crystal alignment film, The photoalignment agent for repair contains a compound having a photoalignment site and a solvent.

Description

Method for producing liquid crystal alignment film, method for repairing defect in liquid crystal alignment film, method for producing liquid crystal device, and photo-alignment agent for repairing Technical Field The present invention relates to a method for producing a liquid crystal alignment film, a method for repairing a defect in a liquid crystal alignment film, a method for producing a liquid crystal device, and a photo-alignment agent for repairing. Background In a liquid crystal display, particularly a liquid crystal display panel for a large-sized television, an angle of view, transmittance, response time, and the like are important performance indexes. As operation modes of liquid crystal display for making the values of these performance indexes good, various modes such as a twisted nematic (TWISTED NEMATIC, TN) type, a Super twisted nematic (Super TWISTED NEMATIC, STN) type, a vertical alignment (VERTICAL ALIGNMENT, VA) type, a polymer stable alignment (Polymer Sustained Alignment, PSA) type, a coplanar switching (IN PLANE SWITCHING, IPS) type, a fringe field switching (FRINGE FIELD SWITCHING, FFS) type, and the like have been developed. In addition, large-sized televisions using these liquid crystal display mode techniques are currently being mass-produced. A liquid crystal device is provided with a liquid crystal alignment film for controlling alignment of liquid crystal molecules in a liquid crystal cell. If there is a defect in the liquid crystal alignment film, alignment control of liquid crystal molecules in a predetermined direction may not be performed at the defective portion. If the alignment of the liquid crystal molecules cannot be controlled in a predetermined direction, the alignment of the liquid crystal molecules may be disturbed, and the liquid crystal molecules may be recognized as defective (bright spot) by an observer of the liquid crystal device. Accordingly, various methods for repairing a bright point defect of a liquid crystal display device derived from a defect generated in a liquid crystal alignment film have been proposed (for example, refer to patent document 1 or patent document 2). Patent document 1 discloses a method of correcting a bright point defect of a liquid crystal display device by irradiating an alignment film of the active matrix type liquid crystal display device with laser light and partially removing the alignment film. Patent document 2 discloses that, when a defective portion is present in a liquid crystal alignment film formed on a substrate, a repair stamp to which repair ink is applied, and repair ink is applied to the defective portion of the liquid crystal alignment film to repair the defective portion. In addition, in the conventional manufacturing process of a liquid crystal display device, when a defect is detected in a liquid crystal alignment film formed on a substrate, reworking is performed in which the liquid crystal alignment film is peeled off from the substrate to form a liquid crystal alignment film again. [ Prior Art literature ] [ Patent literature ] [ Patent document 1] Japanese patent laid-open No. Hei 8-15660 [ Patent document 2] International publication No. 2010/140443 Disclosure of Invention [ Problem to be solved by the invention ] However, as described in patent document 1, in the method of partially removing the liquid crystal alignment film by irradiating the liquid crystal alignment film inside the panel with laser light from the outside of the apparatus after the liquid crystal display panel is built, there is a concern that the defective portion of the liquid crystal alignment film cannot be irradiated with laser light with good accuracy or alignment disorder of liquid crystal molecules occurs in the portion irradiated with laser light, and thus the bright point defect cannot be sufficiently eliminated. In addition, there is a concern that the reworking may cause damage to the substrate, or the manufacturing cost may be increased in order to form the liquid crystal alignment film again after reworking. Further, in the case of using the repair ink, there is a concern that the alignment direction of the liquid crystal molecules cannot be properly controlled at the repair site using the repair ink, and the bright point defect cannot be sufficiently eliminated. The present invention has been made in view of the above circumstances, and an object thereof is to provide a method for producing a liquid crystal alignment film, which can easily and accurately repair defects existing in the liquid crystal alignment film, and which can obtain a liquid crystal device in which display defects are sufficiently suppressed. [ Means of solving the problems ] According to the present invention, the following methods for producing a liquid crystal alignment film, repairing a defect in a liquid crystal alignment film, producing a liquid crystal device, and repairing a photo-alignment agent can be provided. A method for producing a liquid