JP2013050724A - Method for manufacturing substrate for liquid crystal display device, substrate for liquid crystal display device, and liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a substrate for a liquid crystal display device which can reliably align a liquid crystal without inducing dust or static electricity, and to provide the substrate for the liquid crystal display device, and the liquid crystal display device.SOLUTION: A method for manufacturing a substrate for a liquid crystal display device comprises the steps of: forming a film of material 102 on a substrate 101 for forming a groove to impart liquid crystal alignment property; forming a groove 103, by imprinting, to impart the liquid crystal aligning property to the material 102 for forming the groove on which a film is formed; forming a film of alignment layer material 104 that exhibits the liquid crystal aligning property by irradiation, on an upper face of the film on which the groove 103 is formed; and subjecting the alignment layer material 104 on which a film is formed to alignment processing to impart the liquid crystal aligning property by the irradiation 105.

Description

  The present invention relates to a method for manufacturing a substrate for a liquid crystal display device that exhibits liquid crystal orientation suitable for alignment of a liquid crystal display panel, for example, a substrate for a liquid crystal display device, and a liquid crystal display device.

  For example, a liquid crystal display device such as a liquid crystal display panel has features such as thin and light weight and low power consumption, and is widely used. In this liquid crystal display device, the operation principle uses a change in liquid crystal alignment due to the action of an electric field. Therefore, the uniformity and stability of the liquid crystal alignment are particularly important, and an alignment film is used to align the liquid crystal uniformly.

  In general, an alignment film is formed by applying a solution of polyimide resin or a precursor thereof onto a substrate to form a film, and performing a liquid crystal alignment process by a process called “rubbing” that is rubbed in one direction with baffle ( Patent Document 1). Such rubbing has a problem of generation of dust and static electricity.

On the other hand, an alignment film material that uses a resin having a functional group that reacts with light as an alignment film and performs alignment treatment by irradiating polarized ultraviolet rays or the like has been proposed (see Patent Document 2).
JP 9-185068 A JP 2000-112125 A

  By the way, the alignment film material that performs alignment treatment with light proposed by Patent Document 2 and the like has weaker alignment control force for aligning liquid crystal than rubbing treatment proposed by Patent Document 1 and the like, and therefore, the alignment of the liquid crystal. Defects are likely to occur and are a problem.

  The present invention has been made in view of such circumstances, and there is no generation of dust or static electricity, and a liquid crystal display device substrate manufacturing method, a liquid crystal display device substrate, and a liquid crystal display capable of reliably aligning liquid crystals. The object is to provide a device.

  In order to solve the above-described problems and achieve the object, the present invention is configured as follows.

The invention according to claim 1 is a step of forming a material for forming a groove for imparting liquid crystal orientation on a substrate,
Forming a groove for imparting liquid crystal alignment to the material for forming the film-formed groove by imprinting;
Forming an alignment film material that exhibits liquid crystal alignment by light irradiation on the upper surface of the film in which the groove is formed;
A step of performing an alignment treatment to give liquid crystal alignment by light irradiation to the formed alignment film material;
It is a manufacturing method of the board | substrate for liquid crystal display devices characterized by having.

  The invention according to claim 2 is the method for manufacturing a substrate for a liquid crystal display device according to claim 1, wherein the groove has a width of 1 nm or more and 1000 nm or less.

  The invention described in claim 3 is the method for manufacturing a substrate for a liquid crystal display device according to claim 1, wherein the material for forming the groove is a crosslinkable resin.

  The invention according to claim 4 is the method for producing a substrate for a liquid crystal display device according to claim 3, wherein the crosslinkable resin is a heat crosslinkable resin.

  The invention according to claim 5 is the method for producing a substrate for a liquid crystal display device according to claim 3, wherein the crosslinkable resin is a photocrosslinkable resin.

  The invention according to claim 6 is the method for manufacturing a substrate for a liquid crystal display device according to any one of claims 1 to 5, wherein the substrate is a plastic film.

  The invention described in claim 7 is a substrate for a liquid crystal display device manufactured by the method for manufacturing a substrate for a liquid crystal display device according to any one of claims 1 to 6.

  The invention according to claim 8 is a liquid crystal display device manufactured using the substrate for liquid crystal display device according to claim 7.

  With the above configuration, the present invention has the following effects.

  In the first aspect of the present invention, a material for forming a groove for imparting liquid crystal alignment is formed on the substrate, the groove is formed by imprinting, and the groove is further aligned on the upper surface of the film. By forming a film material and performing alignment treatment by light irradiation, liquid crystal alignment can be performed reliably without generation of dust or static electricity.

  In the invention described in claim 2, the groove has a width of 1 nm or more and 1000 nm or less, and the liquid crystal can be aligned more reliably.

  In the invention according to claim 3, the material for forming the groove is a crosslinkable resin, and the groove can be formed with high accuracy by imprinting.

  In the invention according to claim 4, the crosslinkable resin is a heat crosslinkable resin, and the groove can be formed with high precision by imprinting by heating.

  In the invention according to claim 5, the crosslinkable resin is a photocrosslinkable resin, and the grooves can be formed with high precision by imprinting by light irradiation.

  In the invention described in claim 6, the substrate is a plastic film, can be firmly integrated with the material for forming the groove, is thin and flexible, and is easy to handle.

  According to a seventh aspect of the present invention, there is no generation of dust or static electricity by the method for manufacturing a substrate for a liquid crystal display device according to any one of the first to sixth aspects, and the liquid crystal can be surely produced with a simple configuration. Orientation can be performed.

  According to the eighth aspect of the invention, a liquid crystal display device manufactured using the liquid crystal display device substrate of the seventh aspect and having excellent uniformity and stability of liquid crystal alignment can be obtained.

It is process drawing of the manufacturing method of the board | substrate for liquid crystal display devices of embodiment of a reference example. It is a figure explaining the manufacturing method of the board | substrate for liquid crystal display devices. It is a figure explaining the process of forming a groove | channel. It is a schematic block diagram of the manufacturing method of the board | substrate for liquid crystal display devices of embodiment. It is a figure explaining the manufacturing method of the board | substrate for liquid crystal display devices. It is a figure explaining the structure of the board | substrate for liquid crystal display devices. It is a figure explaining the structure of a liquid crystal display device.

  Embodiments of a method for manufacturing a substrate for a liquid crystal display device, a substrate for a liquid crystal display device, and a liquid crystal display device according to the present invention will be described below. The embodiment of the present invention shows the most preferable mode of the present invention, and the present invention is not limited to this.

First, an embodiment of a method for manufacturing a substrate for a liquid crystal display device will be described.
[Reference embodiment]
1 is a process diagram of a method for manufacturing a substrate for a liquid crystal display device according to an embodiment of a reference example, FIG. 2 is a diagram illustrating a method for manufacturing a substrate for a liquid crystal display device, and FIG. 3 is a diagram illustrating a process of forming a groove. It is.

  As shown in FIG. 1, the method of manufacturing the substrate for a liquid crystal display device according to the embodiment of the reference example includes a step A1 for forming an alignment film material, a step A2 for forming a groove by imprinting, and an alignment treatment. And performing step A3.

(Process A1 for depositing alignment film material)
In step A1 for forming this alignment film material, as shown in FIG. 2A, an alignment film material 2 that exhibits liquid crystal alignment properties is formed on the substrate 1 by light irradiation. As the substrate 1, glass or plastic film can be used. However, the plastic film is thin and flexible and easy to handle. Examples of the plastic film include, but are not limited to, thermoplastic resins such as polyethylene terephthalate, polycarbonate, and polyethersulfone, and crosslinkable resins such as epoxy resins.

  As the alignment film material 2, a photodecomposition type alignment film material having a property of aligning liquid crystal in a direction orthogonal to the polarization direction by irradiating polarized ultraviolet rays can be used, and is formed by coating on the surface of the substrate. However, it is not limited to this, and may be joined by adhesion or the like.

  As the alignment film material 2, for example, an organic film such as polyvinyl cinnamate and polyimide can be used, and liquid crystal alignment ability is imparted by irradiating linearly polarized ultraviolet rays. Further, a polyamic acid thin film can be used, and liquid crystal alignment is imparted by irradiation with polarized or non-polarized radiation while heating to room temperature or higher.

(Process A2 for forming grooves by imprint)
In step A2 of forming this groove by imprinting, as shown in FIG. 2B, a groove 3 for imparting liquid crystal orientation to the formed alignment film material 2 is formed by imprinting. This imprint uses a mold 60 as shown in FIG. The mold 60 has a contact surface 62 having a plurality of scale grooves 61. The mold 60 may use other materials or combinations of materials depending on the embodiment, but in this embodiment, the mold 60 is manufactured using a quartz plate, but nickel (Ni) or the like is used. You may make using. The scale groove 61 may be made by etching or otherwise made on the contact surface 62 using conventional means such as lithography.

  After forming such a mold 60, as shown in FIG. 3B, the contact surface 62 of the mold 60 is pressed against the surface of the alignment film material 2 to be transferred. Here, as shown in FIG. 3C, the scale groove 61 of the contact surface 62 of the mold 60 is transferred to the alignment film material 2 by the imprint method, and the alignment film material 2 is given liquid crystal alignment properties. Groove 3 is formed.

  The grooves 3 are parallel, have a width of 1 nm or more and 1000 nm or less, are larger than 1 μm, and have a depth (or height) of less than 50 nm, whereby liquid crystal alignment can be performed more reliably.

(Step A3 for performing orientation treatment)
In step A3 for performing the alignment treatment, as shown in FIG. 2C, alignment treatment for imparting liquid crystal alignment to the alignment film material 2 in which the grooves 3 are formed by light irradiation 4 is performed. In this embodiment, a substrate for a liquid crystal display device can be obtained by performing an alignment treatment of the alignment film by irradiating polarized ultraviolet rays in a direction orthogonal to the grooves at room temperature.

  As described above, the alignment film material 2 that exhibits liquid crystal alignment is formed on the substrate 1 by light irradiation, and the grooves 3 for imparting liquid crystal alignment to the alignment film material 2 are formed by imprinting. By performing the alignment treatment by irradiation 4, there is no generation of dust and static electricity, and the liquid crystal can be reliably aligned with a simple configuration.

[Embodiment]
FIG. 4 is a schematic configuration diagram of a method for manufacturing a liquid crystal display device substrate according to the embodiment, and FIG. 5 is a diagram illustrating a method for manufacturing a liquid crystal display device substrate.

  As shown in FIG. 4, the manufacturing method of the substrate for a liquid crystal display device of this embodiment includes a step B1 for forming a material for forming a groove, a step B2 for forming a groove by imprinting, and an alignment film. It has process B3 which forms a film into a film, and process B4 which performs orientation processing.

(Step B1 of depositing a material for forming the groove)
In the step B1 of forming a material for forming the groove, as shown in FIG. 5A, a material 102 for forming a groove for imparting liquid crystal alignment is formed on the substrate 101. .

  As the substrate 101, glass and plastic film can be used as in the substrate 1 of the first embodiment.

  As the material 102 for forming the groove, a crosslinkable resin such as an epoxy resin can be used, and the groove is formed by applying to the surface of the substrate. Examples of the crosslinkable resin include a photocrosslinkable resin and a heat crosslinkable resin. An acrylic resin can be used as the photocrosslinkable resin, and an epoxy resin can be used as the thermally crosslinkable resin.

(Process B2 for forming grooves by imprint)
In step B2 of forming the groove by imprinting, as shown in FIG. 5B, a groove 103 for imparting liquid crystal alignment to the material 102 for forming the formed groove is formed by imprinting. Imprinting can use the mold 60 of the embodiment of FIG. 3 to form the groove 103 in the material 102 for forming the groove in the same manner. By using a crosslinkable resin as the material 102 for forming the groove, the groove 103 can be formed with high precision by imprinting. In particular, with the heat crosslinkable resin, the groove 103 can be accurately formed by heating and imprinting. The photocrosslinkable resin can be formed, and the groove 103 can be formed with high accuracy by light irradiation and imprinting, and the compatibility between the processing method and the resin characteristics is improved. The grooves 103 are parallel, have a width of 1 nm or more and 1000 nm or less, are larger than 1 μm, and have a depth (or height) of less than 50 nm, whereby liquid crystal alignment can be performed more reliably.

(Process B3 for depositing alignment film material)
In the step B3 of forming this alignment film material, as shown in FIG. 5C, an alignment film material 104 that exhibits liquid crystal alignment is formed by light irradiation on the upper surface of the film in which the groove 103 is formed. As the alignment film material 104, a photodegradable alignment film material having a property of aligning liquid crystal in the direction orthogonal to the polarization direction by irradiating polarized ultraviolet rays can be used, and is formed by coating on the surface of the substrate. However, it is not limited to this, and may be joined by adhesion or the like.

  As the alignment film material 104, for example, an organic film such as polyvinyl cinnamate or polyimide can be used, and liquid crystal alignment ability can be imparted by irradiating linearly polarized ultraviolet rays. Further, a polyamic acid thin film can be used, and liquid crystal alignment can be imparted by irradiation with polarized or non-polarized radiation while heating to room temperature or higher.

(Step B4 for performing orientation treatment)
In step B4 for performing the alignment treatment, as shown in FIG. 5D, alignment treatment for imparting liquid crystal alignment to the formed alignment film material 104 by light irradiation 105 is performed. In this embodiment, the alignment film is aligned by irradiating polarized ultraviolet rays in a direction orthogonal to the grooves at room temperature to obtain a substrate for a liquid crystal display device.

  In this manner, the material 102 for forming a groove for imparting liquid crystal alignment is formed on the substrate 101, the groove 103 is formed by imprinting, and the alignment film is formed on the upper surface of the film on which the groove 103 is formed. By depositing the material 104 and performing the alignment treatment by the light irradiation 105, the liquid crystal can be reliably aligned without generation of dust or static electricity.

Next, an embodiment of a substrate for a liquid crystal display device will be described.
[Reference embodiment]
As shown in FIG. 6A, a substrate A for a liquid crystal display device according to an embodiment of this reference example is formed by forming an alignment film material 2 that exhibits liquid crystal alignment on a substrate 1 by light irradiation. A groove 3 for imparting liquid crystal orientation to the formed alignment film material 2 is formed by imprinting, and alignment treatment for imparting liquid crystal orientation to the alignment film material 2 formed with the groove 3 by light irradiation is performed. It is manufactured by the manufacturing method of the embodiment.

[Embodiment]
In the liquid crystal display device substrate B of this embodiment, as shown in FIG. 6B, a material 102 for forming a groove for imparting liquid crystal alignment is formed on the substrate 101, and the film is formed. A groove 103 for imparting liquid crystal alignment to the material 102 for forming the groove is formed by imprinting, and an alignment film material 104 that exhibits liquid crystal alignment by light irradiation is formed on the upper surface of the film on which the groove 103 is formed. The alignment film material 104 thus formed is subjected to an alignment treatment that gives liquid crystal alignment by light irradiation, and is manufactured by the manufacturing method of the embodiment.

Next, an embodiment of a liquid crystal display device will be described.
[Embodiment]
The liquid crystal display device C of this embodiment includes a liquid crystal cell 300 as shown in FIG. In this liquid crystal cell 300, the two liquid crystal display device substrates A of the embodiment are combined so that the alignment treatment direction is 90 degrees, a cell gap cell is produced, and the liquid crystal 301 is injected. A process of once heating to a temperature at which it becomes an isotropic liquid and then cooling to room temperature is performed so that the orientation direction and the absorption axis direction are orthogonal to each surface of the two substrates for liquid crystal display device A. The plate 302 is bonded.

[Embodiment]
The liquid crystal display device D of this embodiment has a liquid crystal cell 310 as shown in FIG. In this liquid crystal cell 310, the two liquid crystal display device substrates B of the embodiment are combined so that the alignment treatment direction is 90 degrees, a cell gap cell is formed, the liquid crystal 301 is injected, and the liquid crystal is The polarizing plate is heated so that it becomes an isotropic liquid and then cooled to room temperature, and the orientation treatment direction and the absorption axis direction are perpendicular to each surface of the two liquid crystal display device substrates B. 302 is bonded.

  Thus, the liquid crystal display device includes at least a liquid crystal cell and a polarizing plate. And a polarizing plate consists of a protective film and a polarizing film at least. Generally, a polarizing plate is obtained by dyeing a polarizing film made of a polyvinyl alcohol film with iodine, stretching, and laminating protective films on both sides. In the transmissive liquid crystal display device, the polarizing plate is attached to both sides of the liquid crystal cell, and one or more optical compensation sheets may be disposed. On the other hand, in a reflective liquid crystal display device, it is common to arrange a reflector, a liquid crystal cell, one or more optical compensation sheets, and a polarizing plate in this order. The liquid crystal cell includes a liquid crystal molecule, two substrates for encapsulating the liquid crystal molecule, and an electrode layer for applying a voltage to the liquid crystal molecule. The liquid crystal cell performs ON / OFF display depending on the alignment state of liquid crystal molecules. The liquid crystal cell can be applied to both transmissive and reflective types, such as TN (Twisted Nematic), IPS (In-Plane Switching), OCB (Optically Compensated Bend), VA (Vertically Aligned), ECB (Electrical Bly). A display mode such as a ferroelectric liquid crystal is known.

  Next, examples will be described.

Example 1
On a glass substrate on which indium tin oxide (ITO) is formed as a transparent electrode, a photodegradable alignment film material having a property of aligning liquid crystals in a direction orthogonal to the polarization direction by irradiating polarized ultraviolet rays is applied. After pre-drying for 1 minute on a hot plate at 0 ° C., heat treatment was performed in an oven at 180 ° C. for 30 minutes to obtain an alignment film having a thickness of 60 nm.

  This substrate is set on a sheet of silicone rubber, and a quartz plate having grooves of 10 nm width and 10 nm depth chopped at a cycle of 20 nm on the alignment film surface is pressed at a temperature of 200 ° C. and a pressure of 0.5 MPa to perform imprinting. It was. Then, the alignment film was subjected to an alignment treatment by irradiating polarized ultraviolet rays in a direction orthogonal to the grooves at room temperature to obtain a substrate for a liquid crystal display device.

  Two substrates for a liquid crystal display device were combined so that the alignment treatment direction was 90 degrees, a cell having a cell gap of 5 μm was produced, and liquid crystal was injected. Subsequently, the liquid crystal was once heated to a temperature at which the liquid crystal became an isotropic liquid, and then cooled to room temperature. A polarizing plate was bonded to each surface so that the alignment treatment direction and the absorption axis direction were orthogonal to each other to obtain a test liquid crystal display device.

  When this liquid crystal display device was observed visually and using a microscope, the alignment of the liquid crystal was good.

(Example 2)
A solution of a thermal crosslinking resin was applied on a polyethersulfone film substrate, preliminarily dried for 15 minutes in an oven at 90 ° C., and then heated and crosslinked at 160 ° C. for 60 minutes to obtain a coating film having a thickness of 1 μm.

  This substrate was set on a silicone rubber sheet, and a quartz plate having grooves of 100 nm width and 200 nm depth chopped at a cycle of 200 nm was pressed on the alignment film surface at a temperature of 170 ° C. and a pressure of 1 MPa for imprinting.

  Subsequently, an ITO film was formed on the substrate by sputtering. At that time, the substrate was cooled so as not to exceed 170 ° C.

  Next, a photo-crosslinking type alignment film material having the property of aligning the liquid crystal parallel to the polarization direction by irradiating polarized ultraviolet rays is applied, pre-dried on a 90 ° C. hot plate for 1 minute, and then heated to 150 ° C. It heat-processed for 90 minutes in oven, and obtained the alignment film with a film thickness of 40 nm.

  Thereafter, the alignment film was subjected to an alignment treatment by irradiating polarized ultraviolet rays in a direction parallel to the grooves at room temperature to obtain a substrate for a liquid crystal display device.

  In the same manner as in Example 1, a test liquid crystal display device was manufactured.

  When this liquid crystal display device was observed visually and using a microscope, the alignment of the liquid crystal was good.

(Example 3)
A solution of a photocrosslinking resin was applied onto a film substrate made of polyethersulfone on which ITO was formed and dried in an oven at 120 ° C. for 30 minutes to obtain a coating film having a thickness of 100 nm.

  This substrate is set on a silicone rubber sheet, and a quartz plate having grooves of 50 nm width and depth of 50 nm chopped at a cycle of 100 nm on the alignment film surface is pressed from the back surface of the quartz plate while pressing it at a temperature of 30 ° C. and a pressure of 1 MPa. Was imprinted by crosslinking the photocrosslinked resin.

  Next, a photo-crosslinking type alignment film material having the property of aligning the liquid crystal parallel to the polarization direction by irradiating polarized ultraviolet rays is applied, pre-dried on a 90 ° C. hot plate for 1 minute, and then heated to 150 ° C. It heat-processed for 90 minutes in oven, and obtained the alignment film with a film thickness of 40 nm.

  Thereafter, the alignment film was subjected to an alignment treatment by irradiating polarized ultraviolet rays in a direction parallel to the grooves at room temperature to obtain a substrate for a liquid crystal display device.

  In the same manner as in Example 1, a test liquid crystal display device was manufactured.

  When this liquid crystal display device was observed visually and using a microscope, the alignment of the liquid crystal was good.

(Comparative Example 1)
It implemented like Example 1 except not imprinting. When the liquid crystal display device was observed with a microscope, disclination lines and traces of flow alignment accompanying liquid crystal injection were observed, and the liquid crystal alignment was poor.

(Comparative Example 2)
It implemented like Example 2 except not forming alignment film. When the liquid crystal display device was observed, traces of fluid alignment and random alignment were observed, and the alignment of the liquid crystal was poor.

  The present invention is applicable to, for example, a method for manufacturing a substrate for a liquid crystal display device that exhibits liquid crystal orientation suitable for alignment of a liquid crystal display panel, etc., a substrate for a liquid crystal display device, and a liquid crystal display device. The liquid crystal can be surely aligned.

A1 Process for forming alignment film material A2 Process for forming groove by imprinting A3 Process for performing alignment process 1 Substrate 2 Alignment film material 3 Groove 4 Light irradiation B1 Process for forming film for forming groove B2 Groove Step B3 Step of forming an alignment film material B4 Step of performing an alignment process 101 Substrate 102 Material for forming a groove 103 Groove 104 Alignment film material 105 Light irradiation A Liquid crystal according to a reference example Substrate B for Display Device Substrate C for Liquid Crystal Display Device of Embodiment Liquid Crystal Display Device D of Embodiment of Reference Example Liquid Crystal Display Device 300, 310 of Embodiment Liquid Crystal Cell 301 Liquid Crystal 302 Polarizing Plate

Claims (8)

Forming a material for forming a groove for providing liquid crystal alignment on a substrate;
Forming a groove for imparting liquid crystal alignment to the material for forming the film-formed groove by imprinting;
Forming an alignment film material that exhibits liquid crystal alignment by light irradiation on the upper surface of the film in which the groove is formed;
A step of performing an alignment treatment to give liquid crystal alignment by light irradiation to the formed alignment film material;
A method for producing a substrate for a liquid crystal display device, comprising:   The method for manufacturing a substrate for a liquid crystal display device according to claim 1, wherein the groove has a width of 1 nm to 1000 nm.   The method for manufacturing a substrate for a liquid crystal display device according to claim 1, wherein a material for forming the groove is a crosslinkable resin.   The method for producing a substrate for a liquid crystal display device according to claim 3, wherein the crosslinkable resin is a heat crosslinkable resin.   The method for producing a substrate for a liquid crystal display device according to claim 3, wherein the crosslinkable resin is a photocrosslinkable resin.   The method for manufacturing a substrate for a liquid crystal display device according to any one of claims 1 to 5, wherein the substrate is a plastic film.   A substrate for a liquid crystal display device, which is manufactured by the method for manufacturing a substrate for a liquid crystal display device according to any one of claims 1 to 6. A liquid crystal display device manufactured using the substrate for a liquid crystal display device according to claim 7.