JPH0728039A - Liquid crystal display element and its production - Google Patents

Abstract

PURPOSE:To provide a liquid crystal display element having excellent impact resistance without scattering spacers into picture elements by forming walls consisting of plural resin regions in regions corresponding to the spacing parts between upper and lower band-shaped electrodes. CONSTITUTION:Straight stripe electrodes 2a, 2b and oriented films 4a, 4b are formed on substrates 1a, 1b. The walls 5 of the striped resins are formed on the inter-electrode parts of the substrate 1 in parallel with the longitudinal direction of the electrodes 2. The substrates 1a, 1b are thereafter so stuck to each other that the electrodes 2a, 2b orthogonally crossing each other and are adhered and fixed with a sealing material 7 to form liquid crystal cells. The walls 5 are in the state of adhering the walls to the upper and lower oriented films 4a, 4b at this time. Mixtures composed of photosetting resins and liquid crystal materials are injected into the formed liquid crystal cells to form the display picture elements. The resin materials are then subjected to a photosetting reaction by irradiating the materials with UV rays by using a photomask 3 to form the walls 5 of the resins.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a matrix type liquid crystal display device, and more particularly to an internal structure of the liquid crystal display device and a method for manufacturing the same.

[0002]

2. Description of the Related Art Current liquid crystal display devices, that is, panel structures such as TN (twisted nematic), STN (super twisted nematic), and FLC mode are
The two opposing substrates are bonded to each other via a granular or rod-shaped spacer, and the liquid crystal material is sandwiched between the substrates.

In recent years, there has been a demand for a liquid crystal panel that is strong against external shock.

This problem is especially related to chiral smectic C
It is very important in a display mode using a ferroelectric liquid crystal having a crystal structure called (SmC *) phase.

The liquid crystal molecules of the ferroelectric liquid crystal have a spiral structure in a normal state, but by selecting the liquid crystal layer thickness to be smaller than the spiral pitch of the spiral structure, the ferroelectric liquid crystal has
It is known to have two stable orientation states. These two orientation states are a forward orientation electric field, for example, a first orientation state when a positive voltage is applied, and a reverse electric field, for example, a negative orientation. The second alignment state is applied to the voltage of.

Then, the chiral smectic C (S
Since the mC *) phase has a drawback that it is extremely weak against external shock, it is difficult to put the mode using this ferroelectric liquid crystal into practical use.

As a means for solving the above-mentioned problem, it is considered to install a transparent plate for shock protection on the surface of the panel.

There has also been proposed a technique for improving the rigidity of the panel by taking some measures between the substrates. For example, Japanese Patent Application Laid-Open No. 62-174726 proposes a technique using a spacer having adhesiveness. But,
In this method, the dispersibility of the adhesive spacer is poor, and
As a lump, it adversely affects the orientation, and since the spacers are scattered in the picture element, the contrast is lowered. Also, in terms of impact resistance, practicable reliability has not been obtained.

Further, the conventional spacers are generally granular or rod-shaped, but in JP-A-56-99384, an insulating substance is provided in a columnar shape to replace the spacer. Technology is also proposed. However, with this method, although the role of the spacer can be fulfilled, the strength is weak and the reliability of impact resistance is not satisfactory.

[0010]

As described above, in the conventional liquid crystal display device, the spacers are scattered in the display picture elements, so that the contrast is lowered and the liquid crystal material is vulnerable to impact. Particularly in the case of a mode using a ferroelectric liquid crystal, this countermeasure against shock is a major issue.

The present invention has been made in order to solve the conventional problems as described above, and makes it possible to keep the cell thickness uniform, and to provide a liquid crystal display device having excellent impact resistance and its manufacture. It provides a method.

[0012]

According to the present invention, upper and lower substrates facing each other, a plurality of upper strip electrodes arranged in parallel on the upper substrate at predetermined intervals in the row direction, and a lower substrate. A liquid crystal display device comprising a plurality of lower strip electrodes arranged in parallel in the column direction at predetermined intervals and a display medium sealed in a gap between the upper substrate and the lower substrate, wherein A liquid crystal display element is provided, in which a wall made of a plurality of resin regions is formed in a region corresponding to a gap portion of a side strip electrode.

Further, the liquid crystal display device is characterized in that an insulating film is formed on the plurality of strip electrodes.

Further, the liquid crystal display device is characterized in that an alignment film is formed on the plurality of strip electrodes or the insulating film.

Further, the present invention is a liquid crystal display element characterized in that a spacer is contained only in at least one resin region among the plurality of resin regions.

According to the present invention, upper and lower substrates facing each other, a plurality of upper strip electrodes arranged in parallel on the upper substrate at predetermined intervals in the row direction, and predetermined on the lower substrate in the column direction. In a liquid crystal display device comprising a plurality of lower strip electrodes arranged in parallel with each other at intervals and a display medium sealed in a gap between the upper substrate and the lower substrate, on the upper and lower substrates facing each other. A step of forming a plurality of strip electrodes, a step of forming an insulating film on the strip electrodes formed on one of the substrates facing each other, and a step of forming an insulating film on the strip electrodes or the insulating film. A step of forming an alignment film, a step of performing a rubbing treatment on the formed alignment film surface, and a step of forming a resin column or wall in a specific pattern on a specific region on the surface of the one substrate facing each other. Process and the strip A step of arranging the upper and lower substrates so as to face each other so that the formation surfaces face each other with a constant space therebetween, and injecting a mixture of a photocurable resin and a display medium between the upper and lower substrates facing each other. The liquid crystal is characterized by including the step of forming the display picture element and the step of arranging a light shield on the upper and lower substrates facing each other and irradiating ultraviolet light from the light shield side. A method for manufacturing a display device is provided.

Further, the display picture element is formed by dropping or applying a mixture of a photocurable resin and a display medium between the upper and lower substrates facing each other. The method for producing a liquid crystal display element described in 1.

[0018]

In the liquid crystal display element according to the present invention, a plurality of different resins are formed in columns or walls in regions corresponding to the gaps between the upper and lower strip electrodes on the upper and lower substrates, respectively. , The resin can easily control the cell gap without interspersing spacers in the picture element. Further, since the resin is a resin having photosensitivity, it can be easily arranged at a specific position. Therefore, it is possible to form a matrix structure that surrounds the picture elements on all sides.

Further, in some cases, spacers are dispersed in one of the resins to complete a liquid crystal display element having excellent impact resistance.

[0020]

EXAMPLES The present invention will be described in detail below with reference to specific examples, but the present invention is not limited to these examples.

[0021]

Embodiment 1 As shown in FIGS. 1 and 2, two substrates 1
A linear stripe electrode (thickness 2000 angstrom, width 100 μm, electrode interval 2) made of ITO (compound of indium oxide and tin oxide) or the like on a and 1b
5 μm, number of electrodes 2000 × 2000) 2a, 2b are formed. Flint glass (manufactured by Nippon Sheet Glass Co., Ltd., size 300 mm × 300 mm) is used as the substrates 1a and 1b, and an oxide film OCDType II (manufactured by Tokyo Ohka Co., Ltd.) is applied at a thickness of 1000 Å as an insulating film.
Alignment film 4 is formed by applying a polyimide resin PSI-A-2101-S02 (manufactured by Chisso Corporation) and heat treatment.
After forming a and 4b, the alignment film 4a is formed by using a nylon cloth.
For example, the rubbing treatment is performed in the longitudinal direction of the electrode 2a, and for the alignment film 4b in the direction perpendicular to the electrode 2b.

Then, a uniform mixture of a spherical silica spacer having a diameter of 1.5 μm (manufactured by Catalysts and Chemicals Co., Ltd.) and a negative photoresist OPSR-5600 (manufactured by Tokyo Ohka Co., Ltd.) was spin-coated on the substrate 1a to a thickness of about 1.6 μm. Uniform thickness, through exposure and development steps, between the electrodes of the substrate 1a,
Patterning is performed in parallel with the longitudinal direction of the electrode 2a to form a striped resin wall 5.

After that, the substrates 1a and 1b are attached to each other so that the rubbing directions coincide with each other and the electrodes 2a and 2b are orthogonal to each other, and they are adhesively fixed by a sealing material 7,
Create a liquid crystal cell. At this time, the striped wall 5
Is in a state of being adhered to the upper and lower alignment films 4a and 4b.

In the prepared liquid crystal cell, 0.1 g of trimethylolpropane trimethacrylate, 0.4 g of 2-ethylhexyl acrylate, 0.5 g of isobornyl acrylate, and ferroelectric liquid crystal material ZLI-4237-0.
00 (manufactured by Merck) and initiator Irugacure
184 (manufactured by Ciba-Geigy) 0.1 g of the mixture 9 is injected by a vacuum injection method while the liquid crystal material is in an isotropic liquid state.

After this, for example, as shown in FIG. 2, a photomask 3 is arranged and a high pressure mercury lamp (20 mW / cm ² , 3
(65 nm) for 2 minutes to irradiate ultraviolet rays to carry out the photo-curing reaction of the polymerizable compound and the resin material.
The resin wall 6 was formed as described above.

By laminating a polarizing plate on the formed liquid crystal cell, SSFLC (Surface Stab) is formed.
ilized Ferroelectric Liqu
idCrystal) display element was produced.

The electro-optical characteristic (contrast) of the liquid crystal display element produced as described above was 35.

An impact resistance reliability test was conducted using the liquid crystal display device thus obtained.

In the pressure test, the liquid crystal display element was 5 k
By applying a pressure of g / cm ² and by subjecting the liquid crystal display element to a natural drop from a height of 5 cm to the floor surface in the drop test, the degree of disorder of the alignment of the liquid crystal display element was examined. In each of the above two types of tests, there was no disturbance in the alignment of the liquid crystal.

Therefore, it was found that this liquid crystal display device has good impact resistance of liquid crystal, can strictly maintain the cell thickness, and can easily make the alignment uniform.

Further, when a polarizing plate is attached to the liquid crystal cell, the resin portions 5 and 6 formed as described above hardly transmit light and also sufficiently serve as a light shielding layer.

[0032]

Example 2 The same substrate as in Example 1 was used, and SE was used as the alignment film.
An alignment layer is formed by rubbing using -150 (manufactured by Nissan Chemical Co., Ltd.).

Then, a uniform mixture of a spherical silica spacer having a diameter of 4.3 μm (manufactured by Catalysts and Chemicals Co., Ltd.) and a negative photoresist OPSR-5600 (manufactured by Tokyo Ohka Co., Ltd.) was spin-coated on the substrate 1a to a thickness of about 4.5 μm. Is uniformly applied, and after exposure and development steps, a columnar resin 5 is formed between the electrodes of the substrate 1a as shown in FIG. 4, for example.

After that, the substrates 1a and 1b are attached so that the rubbing directions are orthogonal to each other, and the electrodes 2a and 2b are also orthogonal to each other, and they are adhesively fixed by a sealing material 7,
Create a liquid crystal cell. At this time, the columnar resin 5 is in a state of being adhered to the upper and lower alignment films 4a and 4b.

Then, in the prepared liquid crystal cell, 0.1 g of trimethylolpropane trimethacrylate, 0.4 g of 2-ethylhexyl acrylate, 0.5 g of isobornyl acrylate, and liquid crystal material ZLI-3700-0.
4g of a mixture of CN (cholesteric nonanate) of 0.3% to 00 (manufactured by Merck) and an initiator Irug
The mixture 9 with 0.1 g of the cure 184 is injected by the vacuum injection method.

After this, for example, as shown in FIG. 2, the photomask 3 is arranged and the high pressure mercury lamp (20 mW / cm ² , 3
(65 nm) for 2 minutes to carry out photocuring reaction of the polymerizable compound and the resin material to form resin walls 5 and 6 as shown in FIG. 4, for example.

A TN type liquid crystal display device was prepared by bonding a polarizing plate to the formed liquid crystal cell.

The electro-optical characteristic (contrast) of the liquid crystal display element produced as described above was 38.

[0039]

Example 3 Using the same substrate as in Example 1, PSI was used as an alignment film.
Using -2101-A-02 (manufactured by Chisso Corporation), an alignment layer is formed by rubbing.

Then, a uniform mixture of a spherical silica spacer having a diameter of 1.5 μm (manufactured by Catalysts & Chemicals Co., Ltd.) and a negative photoresist OPSR-5600 (manufactured by Tokyo Ohka Co., Ltd.) was spin-coated on the substrate 1a to a thickness of about 1.6 μm. Is uniformly applied and exposed and developed to form striped resin walls 5 between the electrodes of the substrate 1a as shown in FIG. 1, for example.

On the other substrate 1b, 0.5 g of trimethylolpropane trimethacrylate, 2.0 g of 2-ethylhexyl acrylate, 2.5 g of isobornyl acrylate and a ferroelectric liquid crystal material ZLI-423.
7-000 (manufactured by Merck) and an initiator Iruga
The mixture 9 containing 0.5 g of cure 184, for example, as shown in FIG.
As described above, the hot plate 8 is arranged under the substrate 1b, and the hot plate 8 is set at about 100 ° C. at which the liquid crystal material shows an isotropic liquid state, and the above mixture 9 is placed on the substrate 1b.
Was dropped, applied, and left as it was until it spreads over the entire substrate 1b.

After that, the other substrate 1a is bonded in a constant temperature bath at 100 ° C. so that the rubbing directions are the same and the electrodes 2a and 2b are orthogonal to each other.
b The uniform pressure is applied to the entire surface to bond and fix the peripheral portion of the substrate with the seal material 7.

At this time, the striped wall 5 is in a state of being adhered to the upper and lower alignment films 4a and 4b.

After this, for example, as shown in FIG. 2, a photomask 3 is arranged and a high pressure mercury lamp (20 mW / cm ² , 3
(65 nm) for 2 minutes to irradiate ultraviolet rays to carry out photo-curing reaction of the above-mentioned polymerizable compound and resin material to form resin walls 5 and 6 as shown in FIG. 3, for example.

A SSFLC display element was prepared by bonding a polarizing plate to the formed liquid crystal cell.

The electro-optical characteristic (contrast) of the liquid crystal cell prepared as described above was 35.

An impact resistance reliability test was conducted using the liquid crystal display device thus obtained.

In the pressure test, the liquid crystal display element was 5 k
By applying a pressure of g / cm ² and by subjecting the liquid crystal display element to a natural drop from a height of 5 cm to the floor surface in the drop test, the degree of disorder of the alignment of the liquid crystal display element was examined. In each of the above two types of tests, there was no disturbance in the alignment of the liquid crystal.

Therefore, it was found that this liquid crystal panel has good impact resistance of liquid crystal, can strictly maintain the cell thickness, and can easily make the alignment uniform.

Further, when a polarizing plate is attached to the liquid crystal cell, the resin portions 5 and 6 formed as described above hardly transmit light and also sufficiently serve as a light shielding layer.

The liquid crystal material used in Examples 1 to 3 described above is an organic mixture which exhibits a liquid crystal state at around room temperature,
Nematic liquid crystals (including liquid crystals for dual-frequency driving and liquid crystals with Δε <0), cholesteric liquid crystals, smectic liquid crystals, ferroelectric liquid crystals, and discotic liquid crystals can be used.

Specifically, in the nematic liquid crystal, ZLI
3700-000, ZLI-4801-000, ZLI
-4801-001, ZLI-4792 (manufactured by Merck & Co., Inc.), and ferroelectric liquid crystal materials include ZLI-4237-00.
0, ZLI-4237-001, ZLI-4003 (manufactured by Merck & Co., Inc.) and the like are preferable, but not limited thereto.

Of the two kinds of photosensitive resin materials used in this embodiment, the resin 5 is the negative photoresist 0PS.
R-5600 (manufactured by Tokyo Ohka Co., Ltd.) is used, but any positive or negative photoresist can be used as long as it is a photoresist. Alternatively, photosensitive polyimide, photosensitive polyamide, or the like may be used. Further, the prepolymer (monomer, oligomer, etc.) used as the photosensitive resin of the resin 6 is a substance that finally forms the pillar or wall of the polymer that supports the liquid crystal droplets, and its selection is very important. In particular, when driving a TFT, the liquid crystal in the liquid crystal cell and the electrical insulation of the polymer are required, and the specific resistance of the monomer is 1 × even in the uncured state.
Since 10 ¹² Ω · cm or more is required, the photosensitive resin that can be used is either a photocurable resin or a polymer substance.

Examples of the photo-curable resin include acrylic acid and acrylic acid ester having a long chain alkyl group of C3 or more, or a benzene ring, and more specifically, isobutyl acrylate, stearyl acrylate, lauryl acrylate, Isoamyl acrylate, n-butyl methacrylate, n-lauryl methacrylate, tridecimer tacrylate, 2-ethylhexyl acrylate, n-stearyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, 2-phenoxyethyl methacrylate, isobornyl acrylate, isobornyl Methacrylate, and bifunctional or higher polyfunctional resin for increasing the physical strength of the polymer, for example, bisphenol A dimethacrylate, bisphenol A diacrylate, 1.4- Tan diol dimethacrylate,
1.6-hexanediol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, even more preferably halogenated, especially chlorinated, and fluorinated resins of these monomers, for example: 2.2.3.3.4.4-Hexafluorobutyl methacrylate, 2.2.3.3.4.4-hexachlorobutyl methacrylate, 2.2.3.3-Tetrafluoropropyl methacrylate, 2.2. 3.3-Tetrafluoropropyl methacrylate, perfluorooctylethyl methacrylate, perchlorooctylethyl methacrylate, perfluorooctylethyl acrylate,
Perchlorooctylethyl acrylate etc. can be used.

These monomers may be used alone or in combination of two or more. In addition, chlorinated and fluorinated polymers or oligomers may be mixed and used with these monomers, if necessary.

As the photopolymerization initiator, Irugacur
e184, 651, 907, Darocure 117
3, 1116, 2959 (manufactured by Ciba Geigy) can be used.

The shape of the resin to be formed is not particularly limited. For example, it may be formed in a stripe shape or a matrix shape between the electrodes, or may be formed in a pillar shape or a dot shape at the intersection of the upper and lower electrodes. it can.

The method for forming the resin is also not particularly limited, and a photomask may be used or line scanning may be performed with a beam spot.

[0059]

As described above, according to the present invention, a plurality of resin walls are formed between picture elements, and one of the resin walls is adhered to the upper and lower substrates. The walls of the resin serve as spacers without scattering spacers, and since the ground contact area is larger than that of granular spacers, a sufficient effect can be obtained in terms of impact resistance as well.
Also, when the resin contains a spacer, the effect of the resin wall containing the spacer is large, such as improvement of impact resistance, especially in a display mode using a ferroelectric liquid crystal. Become.

Further, the resin according to the present invention can form a matrix structure surrounding the four sides of the picture element, and since the polarizing plate completely blocks light under crossed Nicols, a shielding layer between the respective picture elements is provided. Can also play the role of.

[Brief description of drawings]

FIG. 1 is a perspective view illustrating a liquid crystal display element of Examples 1 and 3 and showing a resin wall in a liquid crystal cell.

FIG. 2 is a cross-sectional view illustrating a liquid crystal display device of Examples 1, 2, and 3 and showing a positional relationship between a liquid crystal cell and a photomask.

FIG. 3 is a perspective view illustrating the liquid crystal display elements of Examples 1 and 3 and showing the shapes of two kinds of resins in a liquid crystal cell.

FIG. 4 is a plan view for explaining the liquid crystal display element of Example 2 and showing the shapes of two kinds of resins when the liquid crystal cell is viewed from directly above.

FIG. 5 is an overall view illustrating a liquid crystal display element of Example 3 and showing a manufacturing method.

[Explanation of Codes] 1a, 1b Substrate 2a, 2b Electrode 3 Photomask 4a, 4b Alignment film 5 Resin 1 6 Resin 2 7 Sealing material 8 Hot plate 9 Liquid crystal-photocurable resin mixture

Claims (6)

[Claims] 1. An upper substrate and a lower substrate facing each other, a plurality of upper strip electrodes arranged in parallel on the upper substrate at predetermined intervals in a row direction, and a predetermined interval on a lower substrate in a column direction. In a liquid crystal display device comprising a plurality of lower strip electrodes arranged in parallel with each other and a display medium sealed in a gap between the upper substrate and the lower substrate, corresponding to a gap portion between the upper and lower strip electrodes. In the area to
A liquid crystal display element, wherein a wall formed of a plurality of resin regions is formed. 2. The liquid crystal display element according to claim 1, wherein an insulating film is formed on the plurality of strip electrodes. 3. The liquid crystal display element according to claim 1, wherein an alignment film is formed on the plurality of strip electrodes or the insulating film. 4. The liquid crystal display element according to claim 1, wherein a spacer is contained only in at least one resin region of the plurality of resin regions. 5. The upper and lower substrates facing each other, a plurality of upper strip electrodes arranged in parallel on the upper substrate at a predetermined interval in the row direction, and a predetermined interval in the column direction on the lower substrate. In a liquid crystal display device comprising a plurality of lower strip electrodes arranged in parallel with each other and a display medium sealed in a gap between the upper substrate and the lower substrate, on the upper and lower substrates facing each other, Forming a plurality of strip-shaped electrodes respectively, forming an insulating film on the plurality of strip-shaped electrodes formed on one of the substrates facing each other, and forming an alignment film on the plurality of strip-shaped electrodes or the insulating film. And a step of subjecting the formed alignment film surface to a rubbing treatment respectively, and a step of forming a resin column or wall in a specific pattern on a specific region on the one substrate surface facing each other. Forming the strip electrode A step of arranging the upper and lower substrates to face each other so as to face each other at a constant interval; and injecting a mixture of a photocurable resin and a display medium between the upper and lower substrates facing each other. Accordingly, a liquid crystal display comprising: a step of forming the display picture element; and a step of arranging a light shield on the upper and lower substrates facing each other and irradiating ultraviolet light from the light shield side. Device manufacturing method. 6. The display picture element is formed by dropping or applying a mixture of a photocurable resin and a display medium between the upper and lower substrates facing each other. A method for manufacturing a liquid crystal display device according to item 1.