JP7135799B2 - Oriented substrate with electrodes and liquid crystal display element - Google Patents

Description

The present invention relates to a liquid crystal display element and an alignment substrate with electrodes used for the liquid crystal display element.

Liquid crystal display devices have characteristics such as thinness, light weight, and low power consumption, and their applications are expanding in a wide range of fields such as display devices for mobile phones, computers, and televisions. Various display modes such as TN (Twisted Nematic), IPS (In-Plane Switching), and FLC (Ferroelectric Liquid Crystal) have been proposed as the display principle of liquid crystal display elements. It is necessary to regulate the alignment direction in advance.

As a method for regulating the alignment direction of liquid crystal molecules, an alignment film formed using a solution containing polyimide or a polyimide precursor is formed on a substrate, and then a roller wound with cloth such as rayon or cotton is rotated at different speeds. A method in which the surface of the alignment film is rubbed in one direction (rubbing method) by rotating the roller while maintaining a constant distance between the substrate and the substrate, or a method in which linearly polarized ultraviolet rays are irradiated to generate anisotropy in the molecular orientation of the polyimide. (photo-alignment method) and the like are adopted. By these alignment treatments, the liquid crystal molecules are strongly bound to the surface of the substrate with the alignment film and oriented in a certain direction. Hereinafter, the direction in which the liquid crystal molecules are bound by the surface of the substrate with the alignment film and aligned is referred to as the "easy alignment axis".

In recent years, as an improvement measure for improving the low driving voltage property of a liquid crystal display element, a liquid crystal display element having a strong anchoring film on one side of a substrate and a weak anchoring film on the other side (see, for example, Patent Document 1) has been proposed. Proposed. In this specification, a film that regulates the orientation direction of liquid crystal molecules, such as the alignment film described above, is referred to as a "strong anchoring film", and the ability to regulate is referred to as a "strong anchoring ability". Similarly, a film that has a weak orientation regulating force (anchoring) on the substrate surface and can change the direction of the liquid crystal molecules by an electric field or the like even in the vicinity of the film is referred to as a "weak anchoring film." The ability to change the orientation of liquid crystal molecules is referred to as "weak anchoring ability". That is, a "strong anchoring film" is a "film having strong anchoring ability". A "weak anchoring membrane" is a "membrane having weak anchoring ability". A material capable of forming a film having a strong anchoring ability is referred to as a "strong anchoring film-forming material", and a material capable of forming a film having a weak anchoring ability is referred to as a "weak anchoring film-forming material". write.

A layer having both a region having weak anchoring ability and a region having strong anchoring ability is referred to as "both anchoring layers". Although the term "alignment film" for a liquid crystal display device usually indicates the strong anchoring film described above, both anchoring layers are considered to be one form of the "alignment film" in this specification.

An example of Patent Document 1 describes a liquid crystal display element having a weak anchoring film on one side of which a polymer brush is formed on the surface of a substrate and a strong anchoring film which is a rubbed polyimide film on the other side. . Since the weak anchoring film has a weak alignment regulating force of the liquid crystal molecules, a liquid crystal display element having a weak anchoring film on one side and a strong anchoring film on the other side is different from a liquid crystal display element having strong anchoring films on both sides. In comparison, it has the merit of being high in low driving voltage, but at the same time has the demerit of low display responsiveness when the voltage is turned off.

In the liquid crystal display element used for information terminals, the display responsiveness when the voltage is off is not so important, such as when reproducing moving images, and when the voltage is off, such as when displaying the time. There is an area where the time is long and power saving is emphasized.

A liquid crystal display element having a strong anchoring film on both sides is effective for high display responsiveness when the voltage is off, and a strong anchoring film on one side and a strong anchoring film on the other side for excellent power saving. A liquid crystal display device having a weak anchoring film is effective.

Usually, in a single liquid crystal display element, when there are two types of regions where the display responsiveness when the voltage is off and the power saving are emphasized respectively, priority is given to the display responsiveness when the voltage is off, and A liquid crystal display device having a strong anchoring film is used. Therefore, the advantage of improving the low driving voltage property of the liquid crystal display element by providing the weak anchoring film has been known, but the deterioration of the display response when the voltage is off becomes a barrier, and there is an area where the property is emphasized. However, it was not possible to use a weak anchoring film for liquid crystal display elements.

JP 2017-010030

An object of the present invention is to provide a liquid crystal display element in which both a region having a high low driving voltage property and a region having a high display response when the voltage is off exist in a single liquid crystal display device, and to the liquid crystal display device. An object of the present invention is to provide an oriented substrate with electrodes that can be used.

As a result of intensive studies in order to solve the above problems, the inventors of the present invention have found that an electrode provided on a substrate and both anchoring layers having both a region having a weak anchoring ability and a region having a strong anchoring ability An oriented substrate with electrodes capable of generating an electric field parallel to the substrate, and a region having weak anchoring ability occupying the area of both anchoring layers on the electrode region generating the electric field parallel to the substrate The present inventors have found that the above object can be achieved by a liquid crystal display device having an electrode-attached alignment substrate having pixels with an area ratio of 40 to 100%, and have completed the present invention.

The present invention includes the following configurations.
[1] An electrode-attached oriented substrate comprising, on a substrate, at least an electrode and both anchoring layers having both a region having weak anchoring ability and a region having strong anchoring ability;
the electrodes are capable of generating an electric field parallel to the substrate;
An electrode provided with a pixel, wherein the ratio of the area of the area having the weak anchoring ability to the area of the two anchoring layers is 40 to 100% on the electrode area that generates an electric field parallel to the substrate. Oriented substrate.

[2] The pixel according to item [1], further comprising a pixel in which the ratio of the area of the region having the weak anchoring ability to the area of the two anchoring layers on the electrode region is 0 to 20%. oriented substrate with electrodes.

[3] In a pixel in which the ratio of the area of the region having weak anchoring ability to the area of both anchoring layers on the electrode region that generates an electric field parallel to the substrate is 40 to 100%, The oriented substrate with electrodes according to item [1], wherein the ratio of the area of the area having the weak anchoring ability to the area of both the anchoring layers on the non-electrode area other than the area is 0 to 20%. .

[4] A liquid crystal display device comprising the alignment substrate with electrodes according to any one of [1] to [3] and a second alignment substrate facing the alignment substrate with a liquid crystal layer interposed therebetween;
A liquid crystal display device, wherein the second alignment substrate is provided with a strong anchoring film.

An oriented substrate with electrodes according to a preferred embodiment of the present invention has both regions having weak anchoring ability and regions having strong anchoring ability. Therefore, a liquid crystal display element having both a region excellent in low driving voltage property and a region excellent in display response when the voltage is turned off can be produced. In particular, it is useful as a liquid crystal display element in which one of the two strong anchoring films of an IPS display mode liquid crystal display element is replaced with both anchoring layers.

FIG. 4 is a plan view showing examples of pixels, electrode regions, and non-electrode regions; FIG. 4 is a plan view showing an example of a region pattern of the oriented substrate with electrodes of the present invention. FIG. 4 is a plan view showing a specific example of the shape of the region pattern matched to the shape of the electrode in the example of the region pattern of the oriented substrate with electrodes of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows schematic structure of 1st Embodiment of the liquid crystal display element 10 of this invention, and the backlight unit 11 for a display, polarizing plate 12A, and polarizing plate 12B. It should be noted that both the cases where both anchoring layers 13 are regions 13A having weak anchoring ability and regions 13B having strong anchoring ability are represented as shown in FIG. In the first embodiment, the liquid crystal compound Lp having a positive dielectric anisotropy is used, the liquid crystal in the state where the electric field E is applied, and in the case where both the anchoring layers 13 are the regions 13A having a weak anchoring ability FIG. 4 is a cross-sectional view showing the distribution of orientation directions of molecules; In the first embodiment, the liquid crystal compound Lp having a positive dielectric anisotropy is used, the liquid crystal in the state where the electric field E is applied, and in the case where both the anchoring layers 13 are the regions 13B having a strong anchoring ability FIG. 4 is a cross-sectional view showing the distribution of orientation directions of molecules; A plane showing the relationship between the wiring direction of the electrode lines and the orientation direction of the liquid crystal molecules in the vicinity of the weak anchoring film when the liquid crystal compound Lp having positive dielectric anisotropy is used in the first embodiment and no electric field is applied. It is a diagram. FIG. 7 shows both the cases where both anchoring layers 13 are regions 13A having weak anchoring ability and regions 13B having strong anchoring ability. In the first embodiment, the liquid crystal compound Lp having a positive dielectric anisotropy is used, the electrode is in a state where an electric field E is applied, and both the anchoring layers 13 are the regions 13A having a weak anchoring ability. FIG. 3 is a plan view showing the relationship between the wiring direction of lines and the orientation of liquid crystal molecules; In the first embodiment, the liquid crystal compound Lp having a positive dielectric anisotropy is used, and the electrode in the state where the electric field E is applied and in the case where both the anchoring layers 13 are the regions 13B having a strong anchoring ability. FIG. 3 is a plan view showing the relationship between the wiring direction of lines and the orientation of liquid crystal molecules; FIG. 4 is a plan view showing the relationship between the arrangement of Cr comb-teeth electrodes for an IPS cell and the arrangement of both anchoring layers in a two-partition pattern of an example. Two pixels 18 are formed on one alignment substrate with electrodes. The comb-teeth electrodes are arranged in a plane parallel to the substrate along the direction X at regular intervals. FIG. 4 is a plan view showing the relationship between the arrangement of Cr comb-teeth electrodes for an IPS cell and the arrangement of both anchoring layers of the first stripe pattern in the example. Two pixels 18 are formed on one alignment substrate with electrodes. The comb-teeth electrodes are arranged in a plane parallel to the substrate along the direction X at regular intervals. FIG. 4 is a plan view showing the relationship between the arrangement of Cr comb-teeth electrodes for an IPS cell and the arrangement of both anchoring layers of a second stripe pattern in the example. Two pixels 18 are formed on one alignment substrate with electrodes. The comb-teeth electrodes are arranged in a plane parallel to the substrate along the direction X at regular intervals.

<1. Oriented substrate with electrodes of the present invention>
The oriented substrate with electrodes of the present invention is an oriented substrate comprising at least an electrode and both anchoring layers having both a region having weak anchoring ability and a region having strong anchoring ability on the substrate. be.

<1-1. Configuration of Oriented Substrate with Electrodes>
The configuration of the substrate, electrodes, and both anchoring layers in the oriented substrate with electrodes is a configuration in which the electrodes and the two anchoring layers are laminated in this order on the substrate.

The electrodes are divided into pixels. In this specification, for example, in the case of displaying the three primary colors of R (red), G (green), and B (blue), each color is "1 pixel", and R, G, and B together are "3 pixels". It should be written as Furthermore, the regions of the alignment substrate with electrodes corresponding to the pixels displayed by the liquid crystal display element are also referred to as "pixels".

It is preferable that the electrode is composed of a plurality of comb-teeth electrodes per pixel. A region that can generate an electric field parallel to the substrate on and between the comb-teeth electrodes is referred to as an "electrode region", and a region other than the electrode region is referred to as a "non-electrode region". . That is, the pixels in the electrode-attached oriented substrate of the present invention have both electrode regions and non-electrode regions.

Examples of the pixels, the electrode regions, and the non-electrode regions are shown in FIG. Part of the pixel electrodes in FIG. 1 is omitted.

Examples of electrodes used in the textured substrate with electrodes of the present invention include metal electrodes such as Cr used in the examples; Transparent electrodes such as GZO (gallium doped zinc oxide) and ATO (antimony tin oxide). A metal electrode can be formed at a lower cost than a transparent electrode. By using a transparent electrode, the light transmittance of the liquid crystal display element can be improved more than when using a metal electrode.

<1-2. Ratio of area of region having weak anchoring ability to area of both anchoring layers>
In the oriented substrate with electrodes of the present invention, the ratio of the area of the region having the weak anchoring ability to the area of the two anchoring layers on the electrode region (hereinafter referred to as "weak anchoring area ratio") is 40 to 100. % pixels.

On the electrode region, regions with a large weak anchoring area ratio have a high low driving voltage characteristic of the corresponding regions of the liquid crystal display element, and regions with a small weak anchoring area ratio have a high display response when the voltage is turned off.

Therefore, by using an oriented substrate with electrodes having both pixels with a large weak anchoring area ratio on the electrode region and pixels with a small weak anchoring area ratio on the electrode region, a single liquid crystal display element can be obtained. , it is possible to manufacture a liquid crystal display element in which both a region having a high low driving voltage property and a region having a high display response when the voltage is turned off exist.

In order to produce a liquid crystal display element having a region with a high low driving voltage property, it is preferable to have a pixel having a weak anchoring area ratio of 40 to 100% on the electrode region, and the display response when the voltage is OFF is improved. To create a high area, it is preferable to have pixels with a weak anchoring area percentage on the electrode area of 0-20%. A preferred example of a liquid crystal display element having both a region with high low driving voltage and a region with high display response when voltage is off is a pixel having a weak anchoring area ratio on the electrode region of 80 to 100%, and a pixel having a weak anchoring area ratio on the electrode region of 0 to 20%.

Furthermore, by reducing the weak anchoring area ratio of the non-electrode region in the peripheral portion of the pixel where the weak anchoring area ratio on the electrode region is large, a good balance between the low drive voltage property and the display response when the voltage is off is achieved. It is possible to manufacture a liquid crystal display element having a wide area.

Preferably, the weak anchoring area percentage on the electrode region is 60-100%, and the weak anchoring area percentage on the non-electrode region is 0-20%.

<1-3. Region Pattern of Oriented Substrate with Electrodes>
In the pattern of regions of both anchoring layers of the oriented substrate with electrodes of the present invention (hereinafter referred to as “region pattern”), the region having weak anchoring ability and the region having strong anchoring ability are one-dimensional or two-dimensional. It is desirable that the Due to the regularity of the area pattern, the productivity and reproducibility when producing the area pattern are excellent.

Examples of the shape of the region pattern are a two-part shape (2a), a stripe shape (2b), a lattice shape (2c), and a polka dot shape (2d). Examples of these are shown in FIG. Regions (2α) and (2β) in FIG. 2 are regions with weak anchoring ability and regions with strong anchoring ability, or regions with strong anchoring ability and regions with weak anchoring ability, respectively.

As a specific example of the shape of the region pattern that matches the shape of the electrode, both a pixel having a weak anchoring area ratio on the electrode region of 100% and a pixel having a weak anchoring area ratio of 0% on the electrode region. Example (3a) of a two-part shape with pixels and an example of a stripe shape with pixels in which the area ratio of weak anchoring on the electrode region is 80% and the area ratio of weak anchoring on the non-electrode region is 0% (3b) and (3c) are shown in FIG. Regions (3α) and (3β) in FIG. 3 are regions having weak anchoring ability and strong anchoring ability, respectively.

<2. Method for Producing Oriented Substrate with Electrodes>
In the preparation of the oriented substrate with electrodes of the present invention, both anchoring layers are formed on a substrate provided with at least electrodes (hereinafter referred to as "substrate with electrodes").

An example of a method for producing an oriented substrate with electrodes is
After forming a solid film having weak anchoring ability on a substrate with electrodes, the recoating property of the solid film is partially changed by using patterned irradiation of ultraviolet rays, etc., and strong anchoring property is applied to the regions with good recoating property. A method of producing an oriented substrate with electrodes by forming a pattern body having
After forming a pattern body having weak anchoring ability on a substrate with electrodes by using a printing method such as gravure offset printing or flexo printing, a pattern body having strong anchoring ability is formed in the region not having weak anchoring ability. a method of producing an oriented substrate with electrodes by
After forming a solid film having weak anchoring ability on a substrate with electrodes, a pattern body having weak anchoring ability is formed by using a photoresist and undergoing an etching process, and a region not having weak anchoring ability is formed. A method for producing an oriented substrate with electrodes by forming a pattern body having a strong anchoring ability in
Using a photosensitive material on a substrate with electrodes, forming a pattern body having weak anchoring ability by photolithography, and then forming a pattern body having strong anchoring ability in areas not having weak anchoring ability. (hereinafter referred to as "manufacturing method C");
Another method is to form a solid film having a strong anchoring ability on a substrate with electrodes, and then form a pattern body having a weak anchoring ability by an ink jet method to produce an oriented substrate with electrodes.

In any of these methods, the liquid crystal molecules in the vicinity of the region with strong anchoring ability are oriented in a certain direction by performing an orientation treatment process on the pattern body with strong anchoring ability or the solid film with strong anchoring ability. become oriented.

As used herein, the term “recoating property” refers to the properties of a film with respect to the application of a coating liquid onto the film. The state of the film in which the coating liquid spreads well on the film and a coating film can be formed is expressed as “good recoating property”. In the manufacturing method A described above, the recoating property is improved by irradiating ultraviolet rays onto a solid film having poor recoating property.

Among these examples of methods for producing an oriented substrate with electrodes, production method A and production method B, which do not use a development step, are preferable in consideration of productivity in producing an area pattern. Fabrication method A and fabrication method C using an exposure process are preferred. In addition, three manufacturing methods, manufacturing method A, manufacturing method B, and manufacturing method C, are used in the examples described later.

<2-1. Method for expressing weak anchoring ability>
An example of a method for exhibiting weak anchoring ability is a method of using a low surface free energy material such as a fluorine-containing material to reduce the interaction of the surface of the formed film with the liquid crystal material (for example, JP-A-6-202086, hereinafter " A temperature that forms a polymer brush, is higher than the Tg (glass transition temperature) of the coexisting portion of the polymer brush and the liquid crystal material, and allows the shape of the coexisting portion to be freely varied. (for example, JP-A-2014-215421, hereinafter referred to as "method for forming a polymer brush") to reduce the interaction of the coexisting portion with the liquid crystal material by heating to . It should be noted that the method of using a low surface free energy material is used in the examples described later.

A specific example of the method of using a low surface free energy material is to prepare a weak anchoring film-forming material containing a polyfunctional carboxyl compound, a polyfunctional epoxy compound, and a polymerizable surfactant, and apply the material on a substrate. , a method of forming a film having weak anchoring ability by baking, and a weak anchor containing a polyfunctional carboxyl compound, a polyfunctional epoxy compound, a polymerizable surfactant, a polyfunctional acrylate compound, and a photopolymerization initiator. In this method, a ring film-forming material is prepared, the material is applied on a substrate, exposed to light, and baked to form a film having weak anchoring ability. When using a material for forming a weak anchoring film containing a polyfunctional acrylate compound and a photopolymerization initiator, the material is coated on a substrate, pattern-exposed, developed, and baked to form a weak anchoring film. It is possible to form a pattern body having the ability.

A specific example of the method for forming a polymer brush is a method of forming a film having weak anchoring ability by immersing a substrate in a liquid containing a radically polymerizable monomer and subjecting the surface of the substrate to living radical polymerization to form a polymer brush. be.

Among these examples of methods for exhibiting weak anchoring ability, a pattern body having strong anchoring ability is formed when an oriented substrate with electrodes is manufactured by the above-described manufacturing method A, manufacturing method B, or manufacturing method C. A method of using low surface free energy materials that are easy to use is preferred.

<2-2. Method for Expressing Strong Anchoring Ability>
A strong anchoring ability can be expressed by a known method for forming alignment films for liquid crystal display elements. Examples of methods for forming alignment films for liquid crystal display elements are the above-described rubbing method and photo-alignment method. Of these two methods, the photo-alignment method is preferable because it can suppress the deterioration of the weak anchoring ability of the region of the alignment substrate of the present invention having the weak anchoring ability during the alignment treatment process.

Examples of the photo-alignment method include a method using a photoisomerization type material (eg, JP-A-2005-275364), a method using a photodimerization-type material (eg, JP-A-10-251646), and a photodegradation type (for example, JP-A-9-297313). In order to maintain the weak anchoring ability of the region having the weak anchoring ability, among these photo-alignment methods, a method using a photoisomerization type material having high sensitivity at an exposure wavelength of 300 nm or more and a photodimerization type material. is preferred, and a method of using a photoisomerizable material having high sensitivity at an exposure wavelength of 350 nm or more is particularly preferred. Incidentally, in the examples described later, a method using a photoisomerizable material is used.

<3. Liquid crystal display element using the alignment substrate with electrodes of the present invention>
Liquid crystal compounds include a positive type with positive dielectric anisotropy and a negative type with negative dielectric anisotropy. A positive liquid crystal compound has a large dielectric property in the long axis direction of liquid crystal molecules and a small dielectric property in a direction orthogonal to the long axis direction. A negative-type liquid crystal compound has a dielectric property that is small in the longitudinal direction of liquid crystal molecules and large in a direction orthogonal to the longitudinal direction. In the following description of the liquid crystal display element, an example using a positive liquid crystal compound will be described.

The liquid crystal display element has the above-described strong anchoring film, the above-described weak anchoring film, and both of the above-described anchoring layers as alignment films for controlling the alignment direction of liquid crystal molecules. In the liquid crystal display element of the present invention, one of two alignment films facing each other is a strong anchoring film and the other is both anchoring layers.

The oriented substrate with electrodes of the present invention can be used as a substrate having both of the above anchoring layers.

<3-1. First Embodiment>
FIG. 4 is a cross-sectional view showing a first embodiment of the liquid crystal display element 10 of the present invention, and a schematic configuration of a backlight unit 11, a polarizing plate 12A, and a polarizing plate 12B for display. FIG. 5 shows the region 13A in which both the anchoring layers 13 have a weak anchoring ability in the state where the liquid crystal compound Lp with the positive dielectric anisotropy is used and the electric field E is applied in the first embodiment. FIG. 10 is a diagram showing the distribution of orientation directions of liquid crystal molecules in the case. FIG. 6 shows the region 13B in which both the anchoring layers 13 have a strong anchoring ability in the state where the liquid crystal compound Lp with the positive dielectric anisotropy is used and the electric field E is applied in the first embodiment. FIG. 10 is a diagram showing the distribution of orientation directions of liquid crystal molecules in the case. FIG. 7 shows the wiring direction of electrode lines and the alignment direction of liquid crystal molecules in the vicinity of both anchoring layers when the liquid crystal compound Lp with positive dielectric anisotropy is used and no electric field is applied in the first embodiment. FIG. 4 is a diagram showing relationships; FIG. 8 shows the region 13A in which both the anchoring layers 13 have weak anchoring ability in the state where the liquid crystal compound Lp with the positive dielectric anisotropy is used and the electric field E is applied in the first embodiment. FIG. 10 is a diagram showing the relationship between the wiring direction of electrode lines and the alignment of liquid crystal molecules in the case. FIG. 9 shows the region 13B in which both the anchoring layers 13 have a strong anchoring ability in the state where the liquid crystal compound Lp with the positive dielectric anisotropy is used and the electric field E is applied in the first embodiment. FIG. 10 is a diagram showing the relationship between the wiring direction of electrode lines and the alignment of liquid crystal molecules in the case.

As shown in FIG. 4, in the liquid crystal display element of the present invention, a first substrate (LCP-1) on which both anchoring layers 13 are formed is arranged to face the two anchoring layers with a gap therebetween. A second substrate (LCP-2) on which a strong anchoring film 14 is formed, disposed between the two anchoring layers and the strong anchoring film, and transmits or blocks the light by driving liquid crystal molecules. A liquid crystal layer (LCP-3) and a driving electrode layer (LCP-4) for applying an electric field to the liquid crystal molecules in a direction along the first substrate (LCP-1) and the second substrate (LCP-2). ing.

The first substrate (LCP-1) and the second substrate (LCP-2) are made of substrates such as glass, respectively, and are arranged parallel to each other with a predetermined interval.

The polarizing plates 12A and 12B are arranged in crossed Nicols. For example, the polarizing direction of the polarizing plate 12A is the Y direction, and the polarizing direction of the polarizing plate 12B is the X direction.

A drive electrode layer (LCP-4) is provided on either one of the first substrate (LCP-1) and the second substrate (LCP-2). As shown in FIG. 4, in the first embodiment, the drive electrode layer (LCP-4) is provided on the first substrate (LCP-1). The driving electrode layer (LCP-4) is formed by arranging a plurality of electrode lines 15A in parallel along the surface of the first substrate (LCP-1). In FIG. 4, each electrode line 15A is formed linearly so that its wiring direction extends along the direction Y within a plane parallel to the surface of the first substrate (LCP-1). In the drive electrode layer (LCP-4), such electrode lines 15A are arranged at regular intervals along the direction X in a plane parallel to the surface of the first substrate (LCP-1).

EXAMPLES Next, the present invention will be specifically described by examples, but the present invention is not limited in any way.

<Example 1: Liquid crystal display element provided with alignment substrate with two-section pattern electrode>
[Preparation of weak anchoring film forming material (W1)]
A 1,000 mL four-necked flask equipped with a thermometer, a stirrer, a raw material inlet and a nitrogen gas inlet was charged with 604.80 g of dehydrated and purified propylene glycol monomethyl ether acetate (hereinafter referred to as PGMEA) as a polymerization solvent. 34.47 g of carboxylic acid dianhydride, 1,2,3,4-butanetetracarboxylic dianhydride, and 164 g of styrene-maleic anhydride copolymer, SMA1000 (trade name, Kawaseki Co., Ltd.) .11 g, 50.17 g of benzyl alcohol which is a monohydric alcohol, and 10.45 g of 1,4-butanediol which is a polyhydric hydroxy compound were charged, and stirred at 130° C. for 3 hours under a stream of dry nitrogen. After that, the solution after the reaction was cooled to 25°C, 10.80 g of 3,3'-diaminodiphenylsulfone as a diamine and 25.20 g of PGMEA were added, and the mixture was stirred at 20 to 30°C for 2 hours, and then cooled to 115°C. The mixture was stirred for 1 hour and cooled to 30° C. or less to obtain a pale yellow, transparent polyesteramic acid solution (PEA-1) having a solid content concentration of 30% by weight. The weight average molecular weight of the solid content measured by GPC was 10,000.

The weight-average molecular weight in this specification is a value in terms of polystyrene obtained by the GPC method (column temperature: 35° C., flow rate: 1 mL/min). Polystyrene with a molecular weight of 645 to 132,900 as standard polystyrene (for example, polystyrene calibration kit PL2010-0102 from Agilent Technologies Inc.), and PLgel MIXED-D (trade name, Agilent Technologies Inc.) for the column. can be measured using tetrahydrofuran as a mobile phase. The weight-average molecular weights of commercially available products in this specification are values listed in catalogues.

A material for forming a weak anchoring film (W1) was prepared by adding the following weight. As a polyfunctional carboxyl compound, 1.00 g of polyesteramic acid solution (PEA-1) having a solid content concentration of 30% by weight, and as a polyfunctional epoxy compound, Techmore VG3101L (trade name, Printec Co., Ltd., hereinafter abbreviated as "VG3101L") ) 0.30 g, Megafac RS-72-K (trade name, DIC Corporation, hereinafter abbreviated as "RS-72-K") 0.20 g as a polymerizable surfactant, and PGMEA 24.90 g as a solvent.

[Preparation of strong anchoring film forming material (S1)]
1.4184 g of 4,4′-diaminoazobenzene, 0.4184 g of 1,4-bis(4-aminophenyl)butane were added to a 200 mL four-necked flask equipped with a thermometer, a stirrer, a raw material inlet and a nitrogen gas inlet. 5736 g, 0.1281 g of 1,4-bis(4-aminophenyl)piperazine, and 44.0 g of dehydrated N-methylpyrrolidone (hereinafter abbreviated as "NMP") were charged and dissolved with stirring under a stream of dry nitrogen. Next, 3.8799 g of 1,8-bis(3,4-dicarboxylic acid)octane dianhydride and 20.0 g of dehydrated NMP were added and stirred at room temperature for 24 hours to obtain a reaction solution. 20.0 g of ethylene glycol monobutyl ether was added to this reaction solution to obtain a polyamic acid solution having a solid concentration of 6% by weight. Let this polyamic acid solution be (PA1). The weight average molecular weight of the polyamic acid contained in (PA1) was 10,000.

1.9123 g of 1,4-bis(4-aminophenyl)piperazine, 0.9123 g of 4,4′-diaminodiphenyl ether were placed in a 200 mL four-necked flask equipped with a thermometer, a stirrer, a raw material inlet and a nitrogen gas inlet. 8561 g, 0.3082 g of 1,4-phenylenediamine, and 44.0 g of dehydrated NMP were added and dissolved with stirring under a dry nitrogen stream. 1.8354 g of 1,2,3,4-butanetetracarboxylic dianhydride, 1.0880 g of pyromellitic dianhydride and 20.0 g of dehydrated NMP were added and stirred at room temperature for 24 hours. 30.0 g of ethylene glycol monobutyl ether was added to this reaction solution to obtain a polyamic acid solution having a polymer solid concentration of 6% by weight. Let this polyamic acid solution be (PA2). The weight average molecular weight of the polyamic acid contained in (PA2) was 50,000.

A polyamic acid solution (PA1), a polyamic acid solution (PA2), and NMP were charged in the following weights and mixed and dissolved to prepare a strong anchoring film-forming material (S1) having a polymer solid concentration of 4% by weight.

9.00 g of polyamic acid solution (PA1) having a solid concentration of 6% by weight
21.00 g of polyamic acid solution (PA2) having a solid concentration of 6% by weight
NMP 15.00g

[Production of Alignment Substrate 1a with Electrode for Liquid Crystal Display Device Production]
Using the manufacturing method A described above, an alignment substrate 1a with electrodes for manufacturing a liquid crystal display element was manufactured as follows.

The material for forming a weak anchoring film (W1) was spin-coated on a substrate with a Cr comb-teeth electrode for IPS cells at 2,000 rpm for 10 seconds, pre-baked on a hot plate at 100° C. for 2 minutes, and then heated at 230° C. C. for 30 minutes in an oven to obtain a film-coated substrate having a film thickness of approximately 40 nm and having a weak anchoring ability.

An exposure apparatus PHOTO SURFACE PROCESSOR PL2003N-12 equipped with a low-pressure mercury lamp EUV200WS-60 (trade name, Sen Special Light Source Co., Ltd.) that irradiates the obtained film-coated substrate with ultraviolet light containing light with a wavelength of 185 nm and light with a wavelength of 254 nm ( (trade name, SEN Special Light Source Co., Ltd.) and a photomask having a two-section pattern were used for pattern exposure to obtain a substrate with a pattern-exposed film having different recoating properties between the exposed area and the unexposed area. The amount of exposure was measured with an ultraviolet integrating photometer UIT-150 (trade name, Ushio Inc.) and a photodetector UVD-S254 (trade name, Ushio Inc.), and was converted to 10 J/cm ² at a wavelength of 254 nm. .

On the substrate with the patterned exposure film having different recoating properties in the exposed and unexposed areas, the material for forming a strong anchoring film (S1) was spin-coated at 3,000 rpm for 10 seconds, followed by a hot plate at 70°C. A coating film of the material for forming a strong anchoring film was formed on the exposed region of the substrate with the patterned exposure film by pre-baking for 80 seconds.

Next, using Multilight ML-501C/B (trade name, Ushio Inc.) equipped with an ultra-high pressure mercury lamp and a polarizing plate, the coated substrate was irradiated with linearly polarized ultraviolet light in the vertical direction. The amount of exposure was measured with a UV integrated light meter UIT-150 (trade name, Ushio Inc.) and a photodetector UVD-S365 (trade name, Ushio Inc.), and was converted to 2 J/cm ² at a wavelength of 365 nm. . The polarization direction of the linearly polarized ultraviolet rays was perpendicular to the wiring direction of the Cr comb-teeth electrode. By setting this direction, the alignment easy axis of the region having a strong anchoring ability in both anchoring layers of the alignment substrate 1a with electrodes for manufacturing a liquid crystal display element is parallel to the wiring direction of the Cr comb-teeth electrode. becomes.

Further, post-baking was performed in an oven at 230° C. for 20 minutes to obtain an alignment substrate with electrodes having both anchoring layers in a two-section pattern (hereinafter referred to as “alignment substrate 1a with electrodes for manufacturing liquid crystal display element”). FIG. 10 shows the relationship between the arrangement of the Cr comb-teeth electrode for the IPS cell and the arrangement of both anchoring layers of the two-section pattern, and the two light transmittance measurement points (T1) and (T2). The pattern shown in FIG. 10 corresponds to (3a) in FIG.

In the pattern shown in FIG. 10, the weak anchoring area ratio in the pixel with the light transmittance measurement point (T1) is 0% for both the electrode region and the non-electrode region, and the light transmittance measurement point (T2) is 0%. The weak anchoring area ratio in a certain pixel is 100% for both the electrode region and the non-electrode region.

[Fabrication of alignment substrate 2 for fabricating liquid crystal display element]
A strong anchoring film-forming material (S1) was spin-coated on a glass substrate at 2,000 rpm for 10 seconds, and prebaked on a hot plate at 70° C. for 80 seconds to obtain a substrate with a coating film. Next, using Multilight ML-501C/B (trade name, Ushio Inc.) equipped with an ultra-high pressure mercury lamp and a polarizing plate, the coated substrate was irradiated with linearly polarized ultraviolet light in the vertical direction. The amount of exposure was measured with a UV integrated light meter UIT-150 (trade name, Ushio Inc.) and a photodetector UVD-S365 (trade name, Ushio Inc.), and was converted to 2 J/cm ² at a wavelength of 365 nm. . Further, the substrate was post-baked in an oven at 230° C. for 20 minutes to obtain a substrate with a strong anchoring film having a thickness of approximately 100 nm. The obtained substrate with the strong anchoring film is hereinafter referred to as "orientation substrate 2 for manufacturing a liquid crystal display element".

[Preparation of positive liquid crystal composition (LC-1)]
A positive liquid crystal composition (LC-1) was prepared by mixing and dissolving the compounds represented by the following general formulas (2-1) to (2-9) at the indicated weight ratios.

[Production of liquid crystal display element 1a1]
Two substrates, an alignment substrate 1a with electrodes for liquid crystal display element fabrication and an alignment substrate 2 for liquid crystal display element fabrication, were aligned with both anchoring layer sides and strong anchoring film sides facing each other, and alignment with electrodes for liquid crystal display element fabrication was performed. The wiring direction of the Cr comb-teeth electrode of the substrate 1a and the easy alignment axis of the strong anchoring film of the alignment substrate 2 for manufacturing the liquid crystal display element were arranged so as to be parallel to each other. By arranging in this way, among both anchoring layers of the alignment substrate 1a with an electrode for manufacturing a liquid crystal display element, the alignment easy axis of the region having a strong anchoring ability and the strong anchoring of the alignment substrate 2 for manufacturing a liquid crystal display element. The orientation easy axes of the films are parallel. Further, a space was formed between the two anchoring layers and the strong anchoring film for injecting the positive liquid crystal composition (LC-1), and the two films were bonded together to prepare an empty cell with a cell thickness of 4 μm. A positive liquid crystal composition (LC-1) was vacuum-injected into the prepared empty cell and annealed at 120° C. for 5 minutes to prepare a liquid crystal display element 1a1. 4, the wiring direction of the electrode lines 15A and the orientation easy axis of the strong anchoring film 14 are the direction Y. As shown in FIG.

[Evaluation of low drive voltage]
A voltage (hereinafter referred to as “Vmax”) at which the maximum light transmittance is obtained was measured at the light transmittance measurement points (T1) and (T2) of the manufactured liquid crystal display element 1a1. For the measurement, an LCD5100 luminance meter manufactured by Otsuka Electronics Co., Ltd. equipped with a halogen lamp was used. At the time of measurement, the liquid crystal display element 1a1 was sandwiched between two polarizing plates arranged in crossed nicols. was the angle at which the light transmittance of was the minimum. The applied voltage is a rectangular wave (60 Hz). A case where Vmax was less than 8.0V was evaluated as "high", and a case where Vmax was 8.0V or more was evaluated as "low". Table 1 shows the measurement results and evaluation results.

[Evaluation of display responsiveness when voltage is off]
The fall time τf (fall time) was measured at the light transmittance measurement points (T1) and (T2) of the manufactured liquid crystal display element 1a1. For the measurement, an LCD5100 luminance meter manufactured by Otsuka Electronics Co., Ltd. equipped with a halogen lamp as a light source was used. At the time of measurement, the liquid crystal display element 1a1 was sandwiched between two polarizing plates arranged in crossed nicols. It was the angle at which the light transmittance at the time was the minimum. The applied voltage is a square wave (60 Hz, Vmax as described above). Here, τf is the time required for the light transmittance to change from 90% to 10% when the light transmittance at the maximum transmittance voltage is 100% and the transmittance at no voltage is 0%. When the fall time τf was less than 23.5 ms, the display responsiveness when the voltage was off was evaluated as “high”, and when it was 23.5 ms or more, it was evaluated as “low”. Table 1 shows the measurement results and evaluation results.

<Example 2: Liquid crystal display element provided with alignment substrate with first stripe pattern electrode>
A liquid crystal display element 1a2 was fabricated in the same manner as in Example 1, except that the two-partition pattern photomask was changed to a first stripe pattern photomask capable of forming a pattern as shown in FIG. The pattern shown in FIG. 11 corresponds to (3b) in FIG.

The weak anchoring area ratio in the electrode region of the pattern shown in FIG. 11 is (7.0 mm/9.8 mm)=71%, and the weak anchoring area ratio in the non-electrode region is 0%.

At the measurement point (T3) of the obtained liquid crystal display element 1a2, measurement of Vmax, measurement of fall time τf, evaluation of low drive voltage property, and evaluation of display response when voltage is off were performed. For the evaluation, the same evaluation method as that for the liquid crystal display element 1a1 was used. Table 1 shows the respective measurement results and evaluation results.

<Example 3: Liquid crystal display element provided with alignment substrate with second stripe pattern electrode>
A liquid crystal display element 1a3 was fabricated in the same manner as in Example 1, except that the two-partition pattern photomask was changed to a second stripe pattern photomask capable of forming a pattern as shown in FIG. The pattern shown in FIG. 12 corresponds to (3c) in FIG.

The weak anchoring area ratio in the electrode region of the pattern shown in FIG. ×3.5 mm+5.0 mm−9.8 mm)/(23.8 mm−9.8 mm)]=16%.

At the measurement point (T4) of the obtained liquid crystal display element 1a3, measurement of Vmax, measurement of fall time τf, evaluation of low driving voltage property, and evaluation of display response when voltage is off were performed. For the evaluation, the same evaluation method as that for the liquid crystal display element 1a1 was used. Table 1 shows the respective measurement results and evaluation results.

<Example 4: Liquid crystal display element manufactured using manufacturing method B>
[Preparation of weak anchoring film forming material (W2)]
A material for forming a weak anchoring film (W2) was prepared by adding the following weight. 1.00 g of polyesteramic acid solution (PEA-1) having a solid concentration of 30% by weight as a polyfunctional carboxyl compound, 0.30 g of VG3101L as a polyfunctional epoxy compound, and RS-72-K0. 20 g, and as solvents 12.03 g PGMEA and 12.87 g diethylene glycol monobutyl ether.

[Production of Alignment Substrate 1b with Electrode for Liquid Crystal Display Device Production]
The weak anchoring film forming material (W2) was pattern-printed on a substrate with a Cr comb-teeth electrode for IPS cells by a gravure offset method so as to form a two-section pattern as shown in FIG. By pre-baking on the plate for 2 minutes, a substrate with pattern coated film and electrodes was obtained. Next, it was post-baked in an oven at 230° C. for 30 minutes to obtain a substrate with patterned electrodes having a film thickness of about 40 nm and weak anchoring ability.

On the obtained substrate with electrodes and a patterned body having weak anchoring ability, the material for forming a strong anchoring film (S1) was spin-coated at 3,000 rpm for 10 seconds, followed by heating on a hot plate at 70° C. for 80 seconds. By pre-baking, a coating film of the material for forming a strong anchoring film (S1) was formed on the pattern body unformed region of the patterned body-attached substrate having weak anchoring ability.

Next, using Multilight ML-501C/B (trade name, Ushio Inc.) equipped with an ultra-high pressure mercury lamp, the coated substrate was irradiated with linearly polarized ultraviolet rays from the vertical direction. The amount of exposure was measured with an ultraviolet integrating photometer UIT-150 (trade name, Ushio Inc.) and a photodetector UVD-S365 (trade name, Ushio Inc.) and was set to 2 J/cm ² . The polarization direction of the linearly polarized ultraviolet rays was perpendicular to the wiring direction of the Cr comb-teeth electrode. By setting this direction, the alignment easy axis of the region having a strong anchoring ability in both anchoring layers of the alignment substrate 1b with electrodes for manufacturing a liquid crystal display element is parallel to the wiring direction of the Cr comb-teeth electrode. becomes.

Further, by post-baking in an oven at 230° C. for 20 minutes, an alignment substrate 1b with electrodes for manufacturing a liquid crystal display device was obtained.

[Fabrication of liquid crystal display element 1b1]
A liquid crystal display element 1b1 was manufactured using the same manufacturing method as the liquid crystal display element 1a1, except that the alignment substrate 1a with electrodes for liquid crystal display element fabrication was changed to the alignment substrate 1b with electrodes for liquid crystal display element fabrication.

At the measurement points (T1) and (T2) of the obtained liquid crystal display element 1b1, Vmax was measured, the fall time τf was measured, the low drive voltage property was evaluated, and the display response when the voltage was turned off was evaluated. . For measurement and evaluation, the same measurement method and evaluation method as those for the liquid crystal display element 1a1 were used. Table 1 shows the respective measurement results and evaluation results.

<Example 5: Liquid crystal display element manufactured using manufacturing method C>
[Preparation of weak anchoring film forming material (W3)]
A material for forming a weak anchoring film (W3) was prepared by adding the following weight. 1.00 g of polyesteramic acid solution (PEA-1) having a solid concentration of 30% by weight as a polyfunctional carboxyl compound, 0.30 g of VG3101L as a polyfunctional epoxy compound, and RS-72-K0. 30 g, as a polyfunctional acrylate compound, Aronix M-402 (trade name, Toagosei Co., Ltd.) 0.30 g, as a photopolymerization initiator, Adeka Arcles NCI-930 (trade name, ADEKA Co., Ltd.) 0.09 g, and 24.36 g of PGMEA as solvent.

[Production of Alignment Substrate 1c with Electrode for Liquid Crystal Display Device Production]
The material for forming a weak anchoring film (W3) was spin-coated at 1,000 rpm for 10 seconds on a substrate with a Cr comb-teeth electrode for IPS cells, and pre-baked on a hot plate at 100 ° C. for 2 minutes to obtain a coating film. A substrate with attached electrodes was obtained. Next, a photomask forming a two-part pattern as shown in FIG. was pattern-exposed through The exposure amount was measured with an integrating photometer UIT-102 (trade name, Ushio Inc.) and a photodetector UVD-365PD (trade name, Ushio Inc.), and was converted to 100 mJ/cm ² at a wavelength of 365 nm. Subsequently, the film was developed with a 2.38% TMAH aqueous solution at 25°C for 10 seconds, rinsed with running ultrapure water for 60 seconds, and post-baked in an oven at 230°C for 30 minutes to obtain a film thickness of approximately 100 nm at the exposed portion. A pattern body-attached electrode-attached substrate having a weak anchoring ability and a film thickness of approximately 50 nm in the unexposed portion (hereinafter referred to as "an electrode-attached alignment substrate 1c for manufacturing a liquid crystal display element") was obtained.

On the obtained substrate with electrodes and patterned body having weak anchoring ability, the strong anchoring forming material (S1) was spin-coated at 3,000 rpm for 10 seconds, and prebaked on a hot plate at 70° C. for 80 seconds. Thus, a coating film of the material for forming a strong anchoring film (S1) was formed on the unexposed portion of the substrate with a patterned body having weak anchoring ability.

Next, using Multilight ML-501C/B (trade name, Ushio Inc.) equipped with an ultra-high pressure mercury lamp and a polarizing plate, the coated substrate was irradiated with linearly polarized ultraviolet light in the vertical direction. The amount of exposure was measured with a UV integrated light meter UIT-150 (trade name, Ushio Inc.) and a photodetector UVD-S365 (trade name, Ushio Inc.), and was converted to 2 J/cm ² at a wavelength of 365 nm. .

Further, by post-baking in an oven at 230° C. for 20 minutes, an alignment substrate 1c with electrodes for manufacturing a liquid crystal display device was obtained.

[Fabrication of liquid crystal display element 1c1]
A liquid crystal display element 1c1 was produced using the same production method except that the alignment substrate 1a with electrodes for liquid crystal display element production was changed to the alignment substrate 1c with electrodes for liquid crystal display element production.

At the measurement points (T1) and (T2) of the obtained liquid crystal display element 1c1, measurement of Vmax, measurement of fall time τf, evaluation of low driving voltage performance, and evaluation of display response when voltage is off were performed. . For measurement and evaluation, the same measurement method and evaluation method as those for the liquid crystal display element 1a1 were used. Table 1 shows the respective measurement results and evaluation results.

As is clear from Examples 1, 4 and 5, the liquid crystal display element provided with the alignment substrate with electrodes of the present invention has a high low driving voltage region and a display response when the voltage is off, among the single liquid crystal display elements. It can be seen that there are both regions of high volatility.

As is clear from the results of the light transmittance measurement point (T3) in Example 2, the results of the light transmittance measurement point (T4) in Example 3, and the results of the light transmittance measurement point (T2) in Example 1, In the liquid crystal display device comprising the oriented substrate with electrodes of the present invention, when the area ratio of weak anchoring on the electrode region is large and the area ratio of weak anchoring on the non-electrode region is small, weak anchoring on the electrode region Compared to the case where the area ratio is large and the weak anchoring area ratio on the non-electrode region is also large, it can be seen that Vmax does not increase so much and the display response when the voltage is turned off is improved.

A liquid crystal display element provided with the oriented substrate with electrodes of the present invention can be manufactured as a single liquid crystal display element having both a region with high low driving voltage characteristics and a region with high display response when the voltage is off. Furthermore, by controlling the pattern of these areas, it is possible to adjust the display responsiveness of the areas having weak anchoring ability when the voltage is off.

10 Liquid crystal display element 11 Backlight unit 12A, 12B Polarizing plate LCP-1 First substrate LCP-2 Second substrate LCP-3 Liquid crystal layer LCP-4 Drive electrode layer 13 Both anchoring layers 13A Weak anchoring of both anchoring layers region 13B having strong anchoring capability region 14 of both anchoring layers strong anchoring film 15A electrode line 16 pixel electrode 17 common electrode 18 pixel 19 electrode region 20 non-electrode region Lp liquid crystal compound X, Y first substrate and Coordinate axes imaginary on a plane parallel to the second substrate

Claims (3)

An oriented substrate with electrodes, comprising on the substrate at least electrodes and both anchoring layers having both regions with weak anchoring ability and regions with strong anchoring ability;
the electrodes are capable of generating an electric field parallel to the substrate;
A pixel in which the area ratio of the area having the weak anchoring ability to the area of the two anchoring layers on the electrode area that generates an electric field parallel to the substrate is 40 to 100% and 0 to 20%. and an alignment substrate with electrodes. An oriented substrate with electrodes, comprising on the substrate at least electrodes and both anchoring layers having both regions with weak anchoring ability and regions with strong anchoring ability;
the electrodes are capable of generating an electric field parallel to the substrate;
a pixel in which the ratio of the area of the area having the weak anchoring ability to the area of the two anchoring layers is 40 to 100% on the electrode area that generates an electric field parallel to the substrate;
In the pixel, the oriented substrate with electrodes, wherein the ratio of the area of the region having weak anchoring ability to the area of both the anchoring layers on the non-electrode region other than the electrode region is 0 to 20%. A liquid crystal display device comprising the alignment substrate with electrodes according to claim 1 or 2 and a second alignment substrate facing the alignment substrate with a liquid crystal layer interposed therebetween;
A liquid crystal display device, wherein the second alignment substrate is provided with a strong anchoring film.

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