JPH0667163A - Liquid crystal device manufacturing method - Google Patents

Abstract

(57) [Abstract] [Purpose] In a method for producing a liquid crystal device having a light control layer in which a transparent solid substance is dispersed in a continuous layer of the liquid crystal material, the liquid crystal material in the light control layer forming material is partially Actinic rays are irradiated in the oriented state, and characters, patterns, etc. are displayed due to the difference in white turbidity between the oriented portion and the non-oriented portion of the device. [Structure] In a state where a liquid crystal material is partially aligned by partially rubbing an electrode layer of a substrate having an electrode layer or by rubbing a liquid crystal alignment layer partially provided on the electrode layer of the substrate. The light control layer forming material is irradiated with actinic rays.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a liquid crystal device capable of forming a large area, and more specifically, to blocking or opening a field of view, and limiting or blocking transmission of light or illumination light electrically. Or it can be operated thermally and is used as a screen for blocking the field of view in building windows and show windows, and as a curtain for daylighting control, displaying characters and figures, and providing high-speed response. By electrically switching the display,
The present invention relates to a method for manufacturing a liquid crystal device used as a high information display body such as a display of an office automation equipment, an advertising board, a guide board, a decorative display board, or the like.

[0002]

2. Description of the Related Art In order to enable low-voltage driving characteristics, high contrast, and time-division driving, which are important characteristics required for liquid crystal devices, JP-A-1-198725 discloses that a liquid crystal material forms a continuous layer. However, a liquid crystal device in which a polymer substance having a three-dimensional network structure is formed in this continuous layer is disclosed.

In such a liquid crystal device, a light control layer forming material containing a liquid crystal material, a photopolymerizable composition and a photopolymerization initiator is present between two transparent substrates having electrode layers. It can be produced by irradiating ultraviolet light to polymerize the photopolymerizable composition. In order to display patterns, characters, etc. on the liquid crystal device thus created, the electrode layer on the substrate is removed so as to have a predetermined pattern, and a display is applied by applying a voltage to the remaining electrode layer. To do.

[0004]

As described above, the conventional liquid crystal device for displaying patterns and characters requires a step of removing the electrode layer on the substrate in the manufacturing process. But,
An object of the present invention is to provide an inexpensive liquid crystal device capable of displaying a design, characters and the like without requiring a step of removing the electrode layer on the substrate.

[0005]

In order to solve the above problems, the present invention provides a liquid crystal material, a polymerizable composition, and a polymerization initiator between two substrates having at least one transparent electrode layer. The liquid crystal in the light control layer forming material is partially aligned by irradiating the light control layer forming material consisting of and with an actinic ray, and the contrast between the aligned portion and the non-aligned portion caused by the alignment Provided is a method for manufacturing a liquid crystal device, which is characterized by displaying patterns, characters and the like on the device according to the difference.

As a method of partially orienting the light control layer forming material, a generally used method of forming an orientation film on two substrate electrodes and rubbing the orientation film may be used. However, it is also possible to directly rub the electrode layer on the substrate.

That is, in a substrate having two electrode layers used in a cell containing a light control layer, the electrode layer surface of at least one of the substrates is a woven fabric made of nylon, rayon, or the like.
Using deer bark, brush, rubber, etc., the surface of the electrode layer is oriented by repeatedly rubbing it in one direction according to predetermined characters, patterns, and the like. Commonly used TN and S
In a TN type liquid crystal device, a substrate on which an aligning agent such as polyimide is treated is used on the electrode layer, and the treated surface is rubbed. However, it is of course possible to use the substrate thus treated for orientation. is there. The entire surface of the substrate treated with the aligning agent may be partially rubbed, or the necessary portion may be previously coated with the aligning agent and the portion may be rubbed.

The substrate used in the present invention may be a rigid material such as glass or metal, or a flexible material such as a plastic film. The two substrates are opposed to each other and are separated by an appropriate distance. However, at least one of them must be transparent, and the light control layer sandwiched between the two must be visible from the outside, but complete transparency is not essential. If the liquid crystal device is used to act on light passing from one side of the device to the other, both substrates will be provided with appropriate transparency.
An appropriate transparent or opaque electrode can be used for this substrate depending on the purpose.

However, in the case of a flexible material such as a plastic film, it can be used in the production method of the present invention after being fixed to a rigid material such as glass or metal.

Next, an empty cell is created using the substrate created in this way. A combination of one oriented substrate and an unoriented substrate may be used, or both oriented substrates may be used. Usually, it is desirable to dispose a spacer for holding a gap between the two substrates, as in a known liquid crystal device. As the spacer, for example, Mylar,
Various liquid crystal cells such as alumina and polymer beads can be used. The two substrates with the spacers sandwiched between them are filled with an injection hole, and the peripheral portion is sealed with a thermosetting or UV-curable sealant to form an empty cell. The liquid crystal material used in the present invention does not need to be a single liquid crystal compound, and may be a mixture containing two or more kinds of liquid crystal compounds or substances other than the liquid crystal compound. Any material recognized as a liquid crystal material in the technical field may be used, and one having a positive dielectric anisotropy is preferable. The liquid crystal used is preferably a nematic liquid crystal, a smectic liquid crystal or a cholesteric liquid crystal, and particularly preferably a nematic liquid crystal. To improve its performance, a cholesteric liquid crystal, a chiral nematic liquid crystal, a chiral smectic liquid crystal, a chiral compound, a dichroic dye, or the like may be appropriately contained.

The liquid crystal material is 4-substituted benzoic acid 4 '.
-Substituted phenyl ester, 4-substituted cyclohexanecarboxylic acid 4'-substituted phenyl ester, 4-substituted cyclohexanecarboxylic acid 4'-substituted biphenyl ester, 4-
(4-Substituted cyclohexanecarbonyloxy) benzoic acid 4′-substituted phenyl ester, 4- (4-substituted cyclohexyl) benzoic acid 4′-substituted cyclohexyl ester,
4-substituted 4'-substituted biphenyl, 4-substituted phenyl 4 '
-Substituted cyclohexane, 4-substituted 4 ″ -substituted ta-phenyl, 4-substituted biphenyl 4′-substituted cyclohexane,
Examples thereof include 2- (4-substituted phenyl) -5-substituted pyrimidine. The proportion of the liquid crystal material in the light control layer is preferably in the range of 60 to 95% by weight, particularly 75 to 8%.
A range of 5% by weight is preferred. This is because if the liquid crystal material is too much or too little, the dispersed state of the liquid crystal material and the transparent solid substance will not be uniform, and the light control function due to light scattering will not be exhibited, which is not preferable.

The transparent solid substance formed in the light control layer may be one in which a liquid crystal material is spherically dispersed in a polymer, but one having a three-dimensional network structure is more preferable. It is preferable that the three-dimensional mesh portion of the transparent solid substance is filled with a liquid crystal material and that the liquid crystal material forms a continuous layer. By forming a disordered state of the liquid crystal material, an optical boundary surface is formed. It is indispensable for forming and expressing light scattering.

A synthetic resin is suitable as the transparent solid substance of the present invention. Examples of a method for forming a three-dimensional network structure include a method of irradiating with ultraviolet rays while keeping the light control layer forming material enclosed in the cell in an isotropic liquid state to polymerize the photopolymerizable composition.

Examples of the polymer-forming monomer that forms the transparent solid substance include styrene, chlorostyrene, and α.
-Methylstyrene, divinylbenzene; as a substituent,
Methyl, ethyl, propyl, butyl, amyl, 2-ethylhexyl, octyl, nonyl, dodecyl, hexadecyl, octadecyl, cyclohexyl, benzyl, methoxyethyl, butoxyethyl, phenoxyethyl, allyl, methallyl, glycidyl, 2-hydroxyethyl, 2
-Acrylate or methacrylate or fumarate having groups such as hydroxypropyl, 3-chloro-2-hydroxypropyl, dimethylaminoethyl, diethylaminoethyl; ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-butylene glycol, Poly (meth) acrylates or poly (meth) acrylates such as tetramethylene glycol, hexamethylene glycol, neopentyl glycol, trimethylolpropane, glycerin and pentaerythritol; vinyl acetate, vinyl butyrate or vinyl benzoate, acrylonitrile, cetyl vinyl ether, limonene. , Cyclohexene, diallyl phthalate, 2-, 3- or 4-vinyl pyridine, acrylic acid, methacryl Acid, acrylamide, methacrylamide, N-hydroxymethyl acrylamide or N-
Hydroxyethylmethacrylamide and their alkyl ether compounds; 3 per mol of trimethylolpropane
Di- or tri (meth) acrylate of triol obtained by adding more than mol of ethylene oxide or propylene oxide; 2 per mol of neopentyl glycol
Di (meth) acrylate of diol obtained by adding more than mol of ethylene oxide or propylene oxide; reaction product of 1 mol of 2-hydroxyethyl (meth) acrylate and 1 mol of phenyl isocyanate or n-butyl isocyanate; dipenta Erythritol poly (meth) acrylate; Tris- (hydroxyethyl) -isocyanuric acid poly (meth) acrylate;
Tris- (hydroxyethyl) -phosphate poly (meth)
Acrylate; mono (meth) acrylate or di (meth) acrylate of di- (hydroxyethyl) -dicyclopentadiene; pivalate ester neopentyl glycol diacrylate; caprolactone modified hydroxypivalate ester neopentyl glycol diacrylate; straight chain aliphatic Diacrylate; polyolefin modified neopentyl glycol diacrylate and the like can be mentioned.

The polymer-forming oligomers include, for example, epoxy (meth) acrylate, polyester (meth) acrylate, polyurethane (meth) acrylate.
And polyester (meth) acrylate can be used.

Examples of the photopolymerization initiator include 2,4
6-trimethylbenzoyldiphenylphosphine oxide (“Lucirin TPO” manufactured by BASF), 2-hydroxy-2-methyl-1-phenylpropan-1-one (“Darocur 1173” manufactured by Merck), 1-hydroxycyclohexylphenylketone ( Ciba Geigy "Irgacure 184"), 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one (Merck "Darocur 1116"), benzyl dimethyl ketal (Ciba Geigy) Made "Irgacure 65
1 "), 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone-1 (Ciba Geigy" Irgacure 907 "), 2,4-diethylthioxanthone (Nippon Kayaku Co., Ltd.) "Kayakyu DETX")
And a mixture of ethyl p-dimethylaminobenzoate (“Kayacure EPA” manufactured by Nippon Kayaku Co., Ltd.), a mixture of isopropyl thioxanthone (“Cantacure ITX” manufactured by Ward Prekinsop) and ethyl p-dimethylaminobenzoate. Etc.

The empty cell produced by the above-mentioned method is placed in a container that can be evacuated, the air in the container is evacuated, and then the injection hole of the empty cell is dipped in the light control layer forming material to keep this state. Meanwhile, the inside of the container is returned to the atmospheric pressure by using an inert dry gas such as nitrogen gas, and the light control layer forming material is injected into the cell. Next, an ultraviolet-curing type sealing agent is applied to the injection hole portion, the volume shrinkage inside the cell due to the decrease of the cell temperature, or the cell is pressurized, and the sealing agent is bulged when the pressure is released. The appropriate amount is taken into the cell and sealed.

The liquid crystal material in the light control layer forming material enclosed in the cell is partially oriented according to the rubbing treatment of the substrate. In this state, a high pressure mercury lamp, an ultra high pressure mercury lamp, a metal halide lamp, etc. are used. By supplying the polymerization energy by using the polymerizable composition to polymerize the polymerizable composition, a dimming layer made of a liquid crystal material and a transparent solid substance is formed, and at the same time, a sealing agent is also cured to produce a liquid crystal device. In the device thus manufactured, the liquid crystal material is partially aligned in the portion where the substrate is rubbed, so that the light scattering degree is lower than that in the unaligned portion.
For this reason, a difference in the degree of light scattering occurs between the oriented portion and the non-oriented portion, and the oriented portion becomes less cloudy than the non-oriented portion. Characters, designs, etc. will be displayed due to the difference in the shade of the cloudiness.

[0019]

EXAMPLES The present invention will now be described more specifically by showing examples of the present invention. However, the present invention is not limited to these examples.

Hereinafter, in the examples, "%" represents "% by weight", and each of the evaluation characteristics means the following symbols and contents. T ₀ : White turbidity; Light transmittance (%) when applied voltage is 0 T ₁₀₀ : Transparency; Light transmittance (%) when the applied voltage is increased with increasing applied voltage V ₁₀ : Threshold value; Applied voltage (Vrms) V _{90 at which} light transmittance is 10% when T ₀ is 0% and T ₁₀₀ is 100%: Saturation voltage; Same as above, applied voltage at which light transmittance is 90% ( Vrms) CR: Contrast = T ₁₀₀ / T ₀

Further, the illuminance of ultraviolet rays was measured using a unimeter with a light receiver UVD-365PD manufactured by Ushio Inc.

A square ITO glass substrate having a side of 30 cm (resistance 100 Ω / cm ² ) is used, the ITO surface is the upper surface, and an alphabet A having a side of about 10 cm and a thickness of about 2 cm is placed under the substrate. Arranged the drawn design. The ITO surface of the substrate was rubbed by rubbing the portion of the letter A repeatedly with a deer skin in a fixed direction.

Using the two substrates thus treated,
The empty cells were created so that the parts of the cells overlap. An empty cell was prepared using Micropearl SP (manufactured by Sekisui Fine Co., Ltd.), which is a spherical spacer having a diameter of 15 μm, as a spacer, and a thermosetting sealing agent DSA-002 (manufactured by Rodik) as a sealing agent. As a liquid crystal material, "PN-00
1 "(Rodick Co.) 84.0%, as a polymerizable oligomer" KAYARAD-HX-220 "(Nippon Kayaku Co., Ltd. caprolactone modified hydroxypivalate neopentylglycol diacrylate) 15.7%, and" lucillin TPO ". (2,4,6-trimethylbenzoyldiphenylphosphine oxide manufactured by BASF)
A light control layer forming material was produced using 0.3%.

While maintaining the above-mentioned 30 cm square empty cell at 40 ° C. in an evacuable container, the empty cell was placed so that the injection hole of the cell was in the lower part. Next, the air in this container was exhausted to about 10 ⁻² Torr, and then the injection hole of the empty cell was immersed in the light control layer forming material. While maintaining this state, nitrogen gas was introduced into the container to return to normal pressure, and the light control layer forming material was injected into the cell.

Next, while maintaining the panel at 40 ° C., the injection hole portion was filled with a UV-curing type sealing agent Photorex A-704.
(Made by Sekisui Fine Co., Ltd.), and then the whole cell is
While maintaining the temperature at 6.3 ° C., ultraviolet rays having an intensity of 30 mW / cm ² were irradiated for 60 seconds to manufacture a liquid crystal device.

When the light control layer of the obtained liquid crystal device was observed with an electron microscope, a three-dimensional network structure composed of a transparent solid substance could be confirmed. "PN-001" physical transition temperature 68.5 ° C. <-25 ° C. refractive index _{n e = 1.787 n o = 1.533} Δn = 0.254 threshold voltage (Vth) 1.15V dielectric anisotropy of Sex Δε = 26.9

In the obtained liquid crystal device, in the state where no voltage was applied, the portion rubbed with A had less cloudiness than the other untreated portions, and the letter A was recognized on the device. When a voltage was applied, the entire surface became transparent.

When the relationship between the applied voltage and the light transmittance of the obtained liquid crystal device was measured, the rubbing treated portion and the untreated portion were as shown in the table below.

[0029]

[Table 1]

[0030]

According to the method of manufacturing a liquid crystal device of the present invention, by partially orienting the liquid crystal material in the cell, it is possible to display simple characters, patterns, etc., and an inexpensive light scattering type liquid crystal device. Can be produced. Therefore, the method for manufacturing a liquid crystal device of the present invention is useful as a method for manufacturing a display element of a computer terminal, a projection display device, a light control glass, and the like.

Claims (3)

[Claims] 1. A light control layer forming material composed of a liquid crystal material, a polymerizable composition and a polymerization initiator is present between at least one transparent substrate having an electrode layer, and an actinic ray is irradiated. According to the method for producing a liquid crystal device, which forms a light control layer composed of a liquid crystal material and a transparent solid substance,
A method for manufacturing a liquid crystal device, which comprises irradiating an actinic ray in a state where the liquid crystal material in the light control layer forming material is partially aligned. 2. The method of manufacturing a liquid crystal device according to claim 1, wherein the liquid crystal material is partially aligned by partially rubbing the electrode layer of at least one of the substrates. 3. A liquid crystal alignment layer is partially provided on an electrode layer of at least one substrate, and the liquid crystal alignment layer is subjected to a rubbing treatment to partially align the liquid crystal material. 1. A method for manufacturing a liquid crystal device according to 1.