JPS63278036A - Liquid crystal optical element and its production - Google Patents

Abstract

PURPOSE:To enable easy production of an element having a good appearance grade and productivity by holding a mixture composed of a prescribed photosetting compd. and liquid crystal material and a spacer for controlling an inter-substrate spacing between a pair of substrates with electrodes thereby immobilizing the phase sepn. with the cured matter. CONSTITUTION:The mixture composed of the photosetting compd. which is so selected that the refractive index of the cured matter to be obtd. coincides with any of the refractive index of the ordinary light of the liquid crystal material to be used, the refractive index of the extraordinary light thereof or the refractive index of the case in which the liquid crystal material is randomly oriented and the liquid crystal material as well as the spacer for controlling the inter-substrate spacing are held between a pair of the substrates with electrodes and the photosetting compd. is cured to immobilize the phase sepn. of the nematic liquid crystal material and the cured matter. The inter-substrate spacing is thereby nearly uniformly controlled and the element having the decreased uneven transmittance and the good appearance grade is obtd. The liquid crystal material and the cured matter in particular are uniformly distributed and the element having the excellent productivity is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an element configuration of a transmission random type liquid crystal optical element and a manufacturing method thereof.

[Prior Art] Conventionally, two modes, dynamic scattering (DS) and phase transition (PC), are known for liquid crystal optical elements whose operation principle is light scattering. In DS mode, liquid crystal with negative dielectric anisotropy doped with a conductive substance is sealed in a horizontally or vertically aligned substrate with transparent electrodes. Two states are controlled: a state in which dynamic scattering is caused by applying a higher voltage, and a state in which transmittance is reduced. In addition, in the PC mode, a cholesteric liquid crystal is sealed in a transparent electrode-equipped substrate that is aligned as necessary, and depending on whether or not a voltage is applied, a nematic phase with a homeotropic alignment (transmission) and a cholesteric phase with a focal conic alignment or Brehner alignment (scattering) are generated. It controls two states. Both DS mode and PC mode do not use polarizing plates, so they have the advantage of providing a wide viewing angle.

Since the former is a current effect type in which a conductive substance is added to the liquid crystal, it has drawbacks such as increased power consumption and reduced reliability of the liquid crystal.

On the other hand, even in the latter case, the operating voltage depends on (interelectrode distance/liquid crystal pitch), so when trying to increase the area, there is a difficult problem that requires a highly accurate and uniform gap. . On the other hand, H, G, Craighea
d et al.^pp1. Phys, Lett.

40 (1122t1982) takes advantage of the characteristic of liquid crystals having refractive index anisotropy. Specifically, liquid crystals are impregnated into a porous body, and the refractive index of the liquid crystals is changed by applying or not applying an electric field. Transmission and scattering are controlled by changing the refractive index of the porous body. This method uses the principle DS mode, P
This is a possible and useful method to overcome the drawbacks of C mode. A similar device is J. L. Fergaso.
With nematic liquid crystal microencapsulated using polyvinyl alcohol, et al.
No. 1), and L.N., Pearlman et al. (Japanese Patent Application Laid-open No. 60-25261) by using various latex-incorporated liquid crystals.
No. 17), and J, 'fJ, Doane et al. described a method of dispersing and curing liquid crystals in epoxy resin (Published in 1982-
No. 502128).

[Problems to be solved by the invention] Since the method of If, G., and Craighead et al. takes a method of impregnating a porous body, the size of the pores and grooves of the liquid crystal used varies, and impregnation of the liquid crystal is difficult. However, it is difficult to adjust the amount of the porous material and the liquid crystal, and there is no flexibility in the ratio of the amount of the porous material to the liquid crystal. Therefore, the transmittance change cannot be sufficiently controlled, and it is difficult to fabricate the device. Also J, L, Fer
The devices by Gason et al., K;
As a result, it has the disadvantage of becoming cloudy and swelling, resulting in a decrease in physical properties. Also, J.L. Doan
A method of curing epoxy resin with ultraviolet rays is disclosed in the method of et al., but since epoxy resin undergoes ionic polymerization but not radical polymerization, it is difficult to cure epoxy resin with the acid produced by decomposing a Lewis acid or protonic acid salt with ultraviolet rays. It performs polymerization.

Therefore, by-products and free acids produced during the decomposition of the salt have resulted in a defect in that the external appearance and reliability of the device are poor.

Such a liquid crystal optical element does not require a strict substrate gap compared to a liquid crystal display element using a normal polarizing film, but as the area increases, unevenness in the substrate gap causes uneven light transmittance. It's starting to happen.

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems, and provides a liquid crystal optical element in which a layer containing a liquid crystal substance is sandwiched between a pair of electrode-attached substrates. , so that the refractive index of the obtained cured product matches either the ordinary refractive index (no), the extraordinary refractive index (ne) of the liquid crystal material used, or the refractive index (ne) when the liquid crystal material is randomly oriented. A mixture of a curable compound and a liquid crystal substance selected as above and a spacer for controlling the substrate gap are held between a pair of electrode-attached substrates, the curable compound is cured, and the phase separation between the liquid crystal substance and the cured product is fixed. A method for producing a liquid crystal optical element in which a mixture containing a liquid crystal substance and a resin is supplied between a pair of electrode-attached substrates, and the mixture is cured. The refractive index of the obtained cured product is made to match either the ordinary refractive index (no), the extraordinary refractive index (ne) of the liquid crystal material used, or the refractive index (n) when the liquid crystal material is randomly oriented. This mixture and a spacer for controlling the substrate gap are held between a pair of electrode-attached substrates, the curable compound is cured, and the liquid crystal substance and the cured material are combined. The present invention provides a method for manufacturing a liquid crystal optical element that fixes phase separation.

In the device of the present invention, the mixture of the liquid crystal substance, the curable compound, and the spacer for controlling the gap between the substrates undergoes a step of curing the curable compound by light exposure or heating, so that the liquid crystal substance and the cured product form a phase with each other. Since the separation is fixed, the gap between the substrates can be controlled to be substantially uniform, and a device with good appearance quality and less unevenness in transmittance can be easily obtained. In particular, by using a photocurable compound that dissolves in the liquid crystal substance as the curable compound, the distribution of the liquid crystal substance and the cured substance becomes uniform, resulting in an element with excellent appearance quality and productivity.

In the present invention, in either a state where no voltage is applied or a state where a voltage is applied, the refractive index of the cured product is the ordinary refractive index (no) and the extraordinary refractive index of the liquid crystal material used. (ne) or the refractive index (ne) when the liquid crystal material is randomly oriented.

As a result, when the refractive index of the obtained cured product and the refractive index of the liquid crystal substance match, light is transmitted, and when they do not match, light is scattered (cloudy).

Taking advantage of this characteristic, the liquid crystal optical element of the present invention is highly effective when used in a light control body.

In addition, in the element of the present invention, the refractive index of the obtained cured product is determined by the ordinary refractive index (ne) or the extraordinary refractive index (ne) of the liquid crystal material.
When no electric field is applied, the liquid crystal material exhibits a scattering state (that is, a cloudy state) due to the difference in refractive index between the unaligned liquid crystal material and the cured material, and when an electric field is applied, In this case, the liquid crystal material is aligned and the refractive index of the liquid crystal (no or n) matches the refractive index of the cured material, indicating a transmitting state, and it is considered an element with reversible dimming function. Become.

In particular, if the orientation of the liquid crystal is perpendicular to the substrate surface when an electric field is applied, haze unevenness will occur.Therefore, the transmittance will increase, so the refractive index of the resulting cured product will be lower than that of the liquid crystal material used. It is preferable to use a combination of a curable compound selected to match 00 and a nematic liquid crystal material with positive dielectric anisotropy.

Further, in the element of the present invention, the refractive index of the cured product can be made to match the refractive index (one) when the liquid crystal material used is randomly oriented. Randomly oriented here does not mean that all liquid crystal molecules are aligned parallel or perpendicular to the substrate surface.
This indicates that the liquid crystal molecules are oriented towards the divine direction due to the influence of the matrix of the cured material. In this case, when no electric field is applied, the liquid crystal material is not aligned,
Since the refractive index of the cured product matches, it shows a transparent state.

On the other hand, when an electric field is applied, the liquid crystal material is aligned and the refractive index of the liquid crystal (no or n) does not match the refractive index of the cured material, resulting in a scattering state (that is, a cloudy state). Become. As a result, a transparent element can be obtained without applying a voltage, but the cured product obtained by curing exists in a network or forms fine microcapsules, and the liquid crystal is randomly affected by this cured product. There is a problem that it is difficult to obtain a uniform state because the orientation is similar to that of 5.

When oriented vertically or horizontally as in the former case, it is easy to achieve a uniform orientation, but when oriented randomly, even if it is random from a macro perspective, when viewed partially, the orientation is However, in the present invention, the refractive index of this cured product and the refractive index of the liquid crystal material used (no, n6, n)
Although it is preferable to make them completely match, it is sufficient to make them match roughly to the extent that the transmission state is not adversely affected. in particular.

It is preferable to keep the difference in refractive index to about 0.15 or less. This is because the cured material swells due to the liquid crystal material and becomes closer to the refractive index of the liquid crystal material than the original refractive index of the cured material, so even if there is a difference of this degree, almost all light will pass through. Become.

The curable compound used in the present invention is preferably a photocurable compound. This enables curing in a short time and improves productivity. Further, it is preferable that the curable compound used at the same time dissolves in the liquid crystal substance used to form a solution. This eliminates the need to use other solvents and eliminates the need to volatilize the solvent during curing.
It has the advantage that it can be cured after being sandwiched between substrates.

As the curable compound of the present invention, it is preferable to use a photocurable vinyl compound. In this case, if it is desired to increase the curing speed, a photocuring initiator may be added, and as long as the material can be photocured by radical species, an element with excellent appearance quality and reliability can be produced. This photocurable vinyl compound is a compound that itself has photoreactivity.
Curing may be induced by a substance generated by light irradiation, and can be broadly classified into those that decompose and harden upon light irradiation and those that undergo monopolymerization and hardening.

Those that undergo polymerization and curing are further divided into those that undergo photodimerization and those that undergo polymerization. Among vinyl groups, many of the former have a cinnamoyl group or a cinnamylidene group, such as polyvinyl cinnamate, polycinnamylidene vinyl acetate, and phenylene diacrylate. In the latter, polymers and oligomers are activated by light and polymerize and cure with each other or with other polymers, oligomers, and polymers, and among vinyl groups, acryloyl, allyl, spiran, and vinyl Examples include benzene-based polymers, oligomers, and polymers. Specifically, 1,000-noacrylate, diacrylate, N-substituted acrylamide, N-vinylpyrrolidone, styrene and its derivatives, polyol acrylate, polyester acrylate, urethane acrylate, epoxy acrylate, silicone acrylate, fluoroalkyl acrylate, having a polybutadiene skeleton Examples include compounds having monofunctional and polyfunctional vinyl groups, such as polyacrylates, polyacrylates having an isocyanuric acid skeleton, acrylates having a hydantoin skeleton, and unsaturated cycloacetals.

In the present invention, these various photocurable vinyl compounds can be used, but it is preferable to use acryloyl compounds.
It is preferable because the phase separation state and uniformity of the liquid crystal and cured product after light exposure are excellent, and the curing speed by light exposure is fast and the cured product is stable. In addition, in the acryloyl group of the acryloyl compound mentioned here, the hydrogens at the 0-position and the β-position may be substituted with a phenyl group, an alkyl group, a halogen, a cyano, or the like.

In the present invention, among these photocurable vinyl compounds, those that are polymerized and cured by light irradiation, particularly those containing oligomers that are polymerized and polymerized, are preferred.

Specifically, 15 to 70 wt of acrylic oligomer containing two or more vinyl groups is used as a photocurable vinyl compound.
% is preferable, so that there is less shrinkage due to curing after photocuring, and small racks are not generated in the liquid crystal optical element.
<, moldability becomes good. As the number of these microcracks increases, the light transmittance in the light transmitting state tends to decrease.
Device performance deteriorates. If the viscosity of this acrylic oligomer is too high or too low, it will adversely affect moldability.
It is preferable to set it as about 150-50000 cps at 0 degreeC.

For the remaining portion of the photocurable vinyl compound, a vinyl monomer can be used. In particular, acrylic mercury is preferred as it has good compatibility with acrylic oligomers.

The acrylic oligomer preferably used in the present invention has the structure of general formula (1) shown below.

The part represented by
It is sufficient to have lCtl-COO-). Specifically, the following structures are possible.

(CIIiCH20). , -ECdltO). etc. (
R-0ji.

ml+,.

(R represents an alkylene group, R' represents hydrogen or an alkyl group, and may be substituted with phenylene or cyclohexylene. In addition, multiple R in the same structural formula,
When R' etc. are present, they may all be the same group, or each may be a hole. Note that these skeletons are merely examples, and may be appropriately selected in consideration of the shape, characteristics, etc. of the element.

Further, the curable compound may be used alone or in a mixture of two or more, and may contain a modifier necessary for device creation, a modifier for the created device, etc. Specifically, the curable compound may be used as a crosslinking agent, It may contain activators, diluents, thickeners, defoamers, adhesion agents, stabilizers, absorbents, dyes, polymerization accelerators, chain transfer agents, polymerization inhibitors, and the like.

The curable compound used in the element of the present invention may be selected from among various materials that meet the above-mentioned requirements, taking into consideration the refractive index of the liquid crystal, solubility with the liquid crystal, and the like.

Further, examples of the photocuring initiator include benzoin ether type, hesiphenone type, acetophenone type, and thioxanthone type.

The liquid crystal material used in the present invention can be nematic liquid crystal or smectic liquid crystal. Although 111 may be used alone or a composition may be used, it can be said that it is more advantageous to use a composition unless various required performances such as operating temperature range and operating voltage are satisfied.

Further, it is preferable that the liquid crystal substance used be one that uniformly dissolves in the photocurable vinyl compound used and does not dissolve or is difficult to dissolve in the cured product after exposure to light. When using a composition, it is desirable that the solubility of the individual liquid crystal substances be as close as possible.

When manufacturing the device of the present invention, the curable compound and liquid crystal substance may be mixed at a mixing ratio of about 5:95 to 75:25.

In particular, when using a photocurable vinyl compound, the ratio of the photocurable vinyl compound and the liquid crystal substance is 5:95 to 45:
It is preferable to form a dissolved mixture of about 55% and a mesh-like matrix can be formed.

When manufacturing the device of the present invention, the mixture of the curable compound and liquid crystal substance to be prepared may be in the form of a solution, a viscous substance, or a dispersion as long as it is uniform; The most suitable one can be selected depending on the manufacturing method of the element.

Specifically, it is generally more convenient to inject in liquid form into a cell in which glass substrates with transparent electrodes such as 1naO+-3nOi, Snow, etc. are placed facing each other and the periphery is sealed. A viscous state is generally more convenient when applying to plastic, glass, or other substrates and stacking opposing substrates together.

The inter-substrate gap can be operated at 5 to 100 μm, but it is appropriate to set it to 7 to 40 μm, taking into account the applied voltage and contrast during on/off.

In this way, the mixture held on the substrate is fixed in a phase-separated state of the liquid crystal material and the cured material by light exposure, heating, or the like. The term "light exposure" as used herein generally means ultraviolet irradiation or electron beam irradiation.

The refractive index of the obtained cured product is determined by the ordinary refractive index of the liquid crystal material (no
) or the extraordinary refractive index (ne), the contents held on the substrate will be colorless and transparent before curing if they are uniformly dissolved, but after curing they will not be aligned. It becomes cloudy due to refractive index scattering due to the liquid crystal material and the cured material.

The device of the present invention produced in this manner becomes transmissive because the liquid crystal substance is aligned and the refractive index matches that of the cured product by applying a voltage.

In addition, when the refractive index of the cured product is made to match the refractive index (ne) of the liquid crystal substance, the contents held on the substrate will be colorless and transparent before curing if they are uniformly dissolved, and after curing is in a transparent state because the refractive indexes of the unaligned liquid crystal material and the cured material match. When a voltage is applied to the device of the present invention produced in this way, the liquid crystal substance is aligned and scattered with a refractive index different from that of the cured product, resulting in a cloudy state.

In the present invention, dichroic dyes, simple dyes, or pigments are added to the liquid crystal, colored curable compounds are used, colored substrates are used, or color filters are laminated. You can also add a specific color.

In the present invention, by using a liquid crystal substance as a solvent and using a photocurable compound that dissolves in the liquid crystal substance, the photocurable compound is cured by light exposure, so that the simple solvent and water that are unnecessary during curing are evaporated. There's no need to do it.

Therefore, since it can be cured in a closed system, it is highly reliable, and the photocurable compound also has the effect of bonding two substrates together, making it possible to eliminate the need for a sealant.

For this purpose, a photocurable compound and a liquid crystal substance melt are supplied onto one substrate with electrodes, and the other substrate with electrodes is superimposed on top of that, and then light is irradiated to harden the material and both electrodes are attached. A highly productive manufacturing method of bonding the substrates can be adopted.

In particular, by using a plastic substrate as the electrode-attached substrate, a long liquid crystal optical element using a continuous plastic film can be easily manufactured.

By using such a liquid crystal with a matrix of liquid crystal and a curable compound, even if the area is large, the risk of shorting between the upper and lower transparent electrodes is low, and the alignment is similar to that of a normal twisted nematic type display element. There is no need to strictly control the distance between the substrates and the gap between the substrates, and a liquid crystal light control body having a large area can be manufactured with extremely high productivity.

As mentioned above, in the liquid crystal optical element of the present invention, the control of the substrate gap is not as strict as that of ordinary liquid crystal display elements, but in order to reduce unevenness in the light transmission state, the substrate gap must be kept constant to some extent. It's better to be. Therefore, in the present invention, a spacer for controlling the gap, such as glass particles, plastic particles, ceramic particles, etc., is arranged in the gap between the substrates.

Specifically, a mixture of a curable compound and a liquid crystal substance containing a spacer for controlling the gap between the substrates is supplied onto a substrate with electrodes, that is, a mixed solution of a curable compound and a liquid crystal substance mixed with a spacer is supplied. Bye. Alternatively, a mixture of a curable compound and a liquid crystal substance may be supplied onto the electrode-attached substrate (011) or a spacer may be supplied afterwards, and then the other electrode-attached substrate may be stacked. In this case, by applying pressure after overlapping and then curing, it is easier to obtain more uniform gaps.

This spacer has a resistance of 0.0% to the mixture of the curable compound and the liquid crystal material. It is sufficient to mix about 10 wt% of old. This is because there is no need for strict gap control like in normal liquid crystal display elements, and because the curable compound hardens to form a network matrix or microcapsules, the amount of spacers is large. Since the spacer is less noticeable even if the spacer is used, the allowable range of addition is wider than that of ordinary liquid crystal display elements. In particular, by using a spacer that has approximately the same refractive index as the refractive index when the curable compound is cured, it can be made extremely inconspicuous.

In addition, as mentioned above, the manufacturing method using the superposition method is suitable for manufacturing the liquid crystal optical element of the present invention, but in this case, unlike the injection method, the spacer does not interfere with injection, so production Extremely sensitive. That is, when injecting liquid crystal into an empty cell with spacers sprinkled thereon for gap control as in a normal liquid crystal display element, it takes several hours to inject even a cell as large as 30 cm square. On the other hand, in the manufacturing method using superimposition of the present invention, even liquid crystal optical elements having an area many times larger than the liquid crystal display element can be superimposed in a few minutes, and since a spacer is used, a large Even in terms of area, the gap between the substrates can be kept almost uniform.

Such a liquid crystal optical element can also be used as a display element, but it is easy to make a large area, for example, a 1 m square element, and it can be cut to a desired size later, so it is difficult to adjust. It is suitable when used as a light body.

When used as a light control body, the electrode is usually a transmissive type, so the electrode is a transparent electrode. Of course, a metal lead portion may also be provided in a part thereof to lower the resistance. Furthermore, when used as a light control mirror, one electrode may be a reflective electrode.

When the substrate of this liquid crystal optical element is made of plastic or thin glass, a protective plate made of plastic or glass is laminated for further protection, or the substrate is made of tempered glass, laminated glass, etc.
Various applications are possible, such as wire-filled glass.

In particular, a liquid crystal optical element is made by using a plastic substrate as a substrate with electrodes, an electrode lead wire is attached, and an adhesive such as polyvinyl butyral is applied between two protective plates such as glass plates that are slightly larger than the liquid crystal optical element. It is preferable to sandwich the liquid crystal optical element and the protective plate through material layers and cure the adhesive material layer by heating or light irradiation to integrate the liquid crystal optical element and the protective plate into a laminated glass-like structure. Among them, by using polyvinyl butyral as the adhesive material, it is possible to obtain a structure extremely similar to that of ordinary laminated glass.

In order to manufacture this liquid crystal optical element, it is possible to prepare two substrates of a desired shape and combine them to manufacture the liquid crystal optical element, or to use a continuous plastic film substrate, or to use a long glass substrate. It may also be manufactured by using a method of manufacturing and cutting it later.

Applications of the liquid crystal optical element of the present invention as a light control body include building materials such as windows, skylights, partitions, and doors, vehicle materials such as windows and moon roofs, and materials such as cases, doors, and lids for various electrical appliances. It can be used for

When applying a voltage to the liquid crystal optical element of the present invention, it is sufficient to apply an alternating current voltage that changes the alignment of the liquid crystal. Specifically, an AC voltage of about 5 to 100 V and about 10 to 1000 Hz may be applied.

Also, when no voltage is applied, the electrodes can be opened or short-circuited. Among these, the impedance between the electrodes, that is, the total impedance of the electrode impedance, the connection impedance at the terminal, and the circuit impedance, is By making the impedance lower than that of the layer of nematic liquid crystal material and cured material, the response of the liquid crystal when the voltage is turned off is fast.

In particular, it is preferable that the impedance between the electrodes be 1710 or less of the impedance of the layer of liquid crystal material and cured material. Therefore, when the impedance of the electrode and the connection impedance at the terminal portion are high, it is preferable to lower the impedance of the circuit.

By forming a self-discharge circuit in this way, even if the capacitance of the element itself is much larger than that of a normal liquid crystal display element, the charge accumulated between the electrodes is quickly discharged, and the liquid crystal display does not inhibit the movement back to a random orientation, and the change between transmission and scattering becomes faster.

The device of the present invention can be used for display devices, especially large-area display devices, curved display devices, etc., which are difficult to use with conventional liquid crystal display devices, as well as large-area light control devices, optical shutters, etc. Many uses are possible. It can also be installed in front of a light source such as a light bulb and used to electrically switch between a fog lamp and a regular lamp.

Further, in the present invention, one of the electrodes may be used as a specular reflective electrode as a mirror, and in this case, the back substrate may be made of opaque glass, plastic, ceramic, or metal.

In addition, color filters can be used in conjunction with the liquid crystal, dichroic dyes can be mixed into the liquid crystal to create color, and other displays such as liquid crystal display elements, electrochromic display elements, electroluminescence display elements, etc. They may be used in a stacked manner, and various applications are possible.

[Example] Hereinafter, the present invention will be specifically explained with reference to Examples.

Example 1 1 part of n-butyl acrylate and 5 parts of 2-hydroxyethyl acrylate were added to liquid crystal rE-8J (manufactured by CBDH)
A uniform solution of 18 parts of benzoin isopropyl ether and 0.12 parts of benzoin isopropyl ether as a photocuring initiator was injected into a glass substrate cell with ITO on which spacers each having a diameter of 25 μm were scattered at about 1 spacer per 1 mm.The injection hole was sealed. After that, the ultraviolet irradiation device Il (manufactured by Hara 2 [Toscure 400J])
When exposed to light for about 60 seconds, the entire exposed surface became cloudy. The transmittance before voltage application was 18.4%, but when AC60V (5GHz) was applied, it became 58.7%.
% transmittance.

(Transmittance meter rM-304Jl manufactured by Asahi Spectroscope Example 2 1 part of n-butyl acrylate and 3 parts of 2-hydroxyethyl acrylate, acrylic oligomer (rM-+200 J manufactured by Toagosei Chemical Co., Ltd., viscosity 30000 cps)
15G'C) 4 parts, Merck Co., Ltd. [Crocure-1116J O, 16 parts, liquid crystal r E] as a photocuring initiator
-8 parts and 4 parts were uniformly dissolved. Spacer approximately 10μm
A device was prepared in the same manner as in Example 1, except that about 5 particles were dispersed per 1 +++ m" in diameter. Voltage application (^C60
The transmittance before and after V, 5 leaves 2) is 37.9% and 76.
It was 8%.

Practical Example 3 3 parts of rope tyl acrylate, acrylic oligomer (
Manufactured by Osaka Organic Chemical Industry Co., Ltd. [Viscoat #823J, viscosity 19000 cps/50°C) 1 part, liquid crystal "E-8"
3 parts and 0.1 part of "Glocure 1116" were uniformly mixed and applied using a doctor blade onto an ITO-attached polyester film substrate temporarily adhered to a glass plate. μm
After scattering 3 m spacers per 1 mm, ITO-attached polyester film substrates temporarily adhered to a glass plate were placed together and exposed to light under the same conditions as in the first experiment to create an element. Applied voltage (AC6QV.

The transmittance before and after 5011z1 is 42.8% and 67, respectively.
．． It was 1%.

By adopting a manufacturing method by overlapping, Example 1,
Compared to Example 2, the time required for manufacturing is extremely shortened,
No phenomenon such as residual bubbles due to insufficient injection occurred.

Example 4 1 part of n-butyl acrylate, 5 parts of 2-hydroxyethyl acrylate, 3 parts of acrylic oligomer (rM-5200J manufactured by Toagosei Kagaku Co., Ltd.), 20 parts of "Crocure-1173J O" as a photocuring initiator, liquid crystal rE
-8 parts of Bji were uniformly dissolved. A device was produced in the same manner as in Example 1, except that the glass plate thickness of the cell used was 3.0 mm and the light exposure time was 3 minutes. Voltage application T
AC60V, 50112) Transmittance before and after is 8
．． 2% and 51.7%.

Example 5 1 part N-(n-butoxymethyl)-acrylamide, n
-butyl acrylate 3 parts, "Crocure IIIJ"
O, 2 parts, liquid crystal manufactured by Roche r TN-623
9.5 parts of J was uniformly dissolved. Cell gap 10μm
A device was produced in the same manner as in Example 2, except that. The transmittance after Oii was 79.2% and 85.2%, respectively.

Example 6 12 parts of n-butyl acrylate, acrylic oligomer (
Toagosei Kagaku rM-+200 J) 24 copies,
Crocure-111641, 4 parts, liquid crystal rE-8J 6
4 parts were uniformly dissolved. After adding a spacer with a diameter of 14 μm and dispersing it well, it was laminated between polyester films with ITO temporarily adhered to a glass plate, and an ultraviolet irradiation device ff (Mitsubishi Electric's "Neolumi Super (30W)" was applied).
J) A device was prepared by exposing it to light for about 90 seconds.

The transmittance when no voltage is applied is 10%, and the transmittance after applying voltage is 67% (AC15V, 50IIz),
It was 81% (AClooV, 50Hz).

Furthermore, this was sandwiched between two glass plates with two polyvinyl butyral films interposed therebetween, and heated and pressurized in an autoclave to integrate them.

The light control body integrated in this way was safe against external pressure and had high reliability.

Example 7 A device was produced in the same manner as in Example 6 except that the spacer was 8 μm. The transmittance when no voltage is applied is 20
%, the transmittance after voltage application is 77% (AC15V, El
[In2), 79% (AC30V, 5011z
)Met.

Example 8 In the device of Example 6, the response time for change in transmittance when the circuit was opened from a state where a voltage of AC 30 V was applied was 1.2 seconds. After the voltage was turned off, both electrodes of the device were short-circuited through an lkΩ resistor, and the response time was 0.02 seconds.

Example 9 An element was produced in the same manner as in Example 6, except that 1.5 parts of "Best Cure 161" manufactured by Atomic Shime Kagaku Kogyo Co., Ltd. was added and dispersed as a colored cured product.

A device that is uniformly colored on the entire surface is obtained, and the transmittance is 7.5% when no voltage is applied, and the transmittance after voltage is 65.8.
% (AClooV, 5011z).

Example 10 7 parts of n-octyl acrylate and 15 parts of 2-hydroxyethyl acrylate, acrylic oligomer rM-
14 parts of 1200J and 64 parts of liquid crystal "E-8J" were uniformly dissolved in 3 parts of benzoin isopropyl ether as a photocuring initiator.This solution was temporarily adhered to a glass plate.
It was coated on a polyester film substrate with a 14 μm diameter, and then a polyester film substrate with an I゛ and 0 that had been temporarily adhered to a glass plate was superimposed on the glass plate. After light exposure for about 60 seconds, an element whose exposed surface became cloudy was obtained. The transmittance before voltage application was 16.3%, but with ACl
When ooV (501Iz) was applied, the transmittance was 78.2%.

This element uses an acrylic oligomer as a raw material, and compared to the element of Example 1, there were fewer microcracks after curing and the change in transmittance due to voltage application was greater.

[Effects of the Invention] As described above, the present invention provides a novel liquid crystal optical element, and the refractive index of the obtained cured product is different from the ordinary refractive index (no) and the extraordinary refractive index of the liquid crystal material used. (ne) or refractive index (ne) when liquid crystal material is randomly oriented
A mixture of a curable compound and a liquid crystal substance selected to match one of the above and a spacer for controlling the substrate gap is held between a pair of electrode-attached substrates, and the curable compound is cured;
The present invention relates to an element having a structure in which the phase separation between a liquid crystal substance and a cured product is fixed so that the liquid crystal is held in a network-like or microcapsule-like matrix of the cured product, and a method for manufacturing the same.

Therefore, the liquid crystal optical element of the present invention does not require a polarizing plate,
It is an element with excellent appearance quality and productivity, and is suitable for display purposes, especially large area and curved displays, as well as large area dimming,
It can be widely used in optical shutters, etc.

In particular, using a nematic liquid crystal material and a photocurable vinyl compound, and using a solution in which the photocurable vinyl compound is dissolved in the nematic liquid crystal material is recommended from the viewpoint of reliability, durability, and productivity. It's nice to see.

In the present invention, since a spacer for controlling the gap between the substrates is used, short circuits between the substrates are unlikely to occur even when the area is increased, and a highly productive manufacturing method such as the overlapping method can be easily adopted.

In the present invention, if a photocurable compound is used, the reliability of the device is high, the device having a laminated glass-like structure can be easily produced, and the device is highly safe and resistant to breakage due to external pressure.

Furthermore, by providing a protective plate on at least one side of this substrate, safety is improved, and in particular, by providing protective plates on both sides, damage becomes less likely to occur.

In particular, supplying a liquid crystal substance, a curable compound, and optionally a mixture with a curing initiator and a spacer on the substrate;
By placing the other substrate a on top of the substrate, large-area devices can be manufactured with extremely high productivity. For this reason, even in the case of glass substrates, fairly long substrates can be used, and in the case of plastic substrates, continuous processes using continuous films are also possible.

In particular, when a plastic substrate is used as the substrate, although productivity is good, the strength is poor, so when the area is increased, the substrate is easily damaged or bent. Therefore, the effect of providing protective plates on both sides is great. In particular, by using a glass plate as a protective plate and bonding it with an adhesive material, it has a structure similar to laminated glass, making it even safer and more reliable.

Furthermore, in the liquid crystal optical element of the present invention, since the liquid crystal substance is dispersed in the gaps of the network-like or microcapsule-like matrix of the cured compound, the element can be cut into a desired size after manufacturing. can.

In particular, compared to devices consisting of microcapsules or independent liquid crystal grains, devices in which liquid crystal dispersions are interconnected in a network matrix are preferred, and the liquid crystals are more likely to be aligned uniformly when voltage is applied. Therefore, the haze in the transparent state is small, and the driving voltage can be low. This also has the effect of preventing the element from becoming reddish when it is in a cloudy state.

The present invention can be applied in various other ways as long as the effects of the present invention are not impaired.

Procedural amendment March 1986/Joichi

Claims (30)

[Claims] (1) In a liquid crystal optical element formed by sandwiching a layer containing a liquid crystal substance between a pair of substrates with electrodes, the refractive index of the obtained cured product is the ordinary refractive index (n_o) of the liquid crystal substance used,
A mixture of a curable compound and a liquid crystal material selected to match either the extraordinary refractive index (n_e) or the refractive index when the liquid crystal material is randomly oriented (n_x) and a spacer for controlling the gap between the substrates. A liquid crystal optical element, characterized in that it is held between a pair of electrode-attached substrates, a curable compound is cured, and phase separation between a liquid crystal substance and a cured product is fixed. (2) A curable compound selected so that the refractive index of the resulting cured product matches the ordinary refractive index (n_o) or extraordinary refractive index (n_e) of the liquid crystal substance used is used. The liquid crystal optical element according to item 1. (3) A patent claim that uses a curable compound selected so that the refractive index of the obtained cured product matches the ordinary refractive index (n_o) of the liquid crystal material used, and a liquid crystal material with positive dielectric anisotropy. 2. The liquid crystal optical element according to item 2. (4) The liquid crystal optical element according to claim 1, wherein the curable compound used is a photocurable compound. (5) The liquid crystal optical element according to claim 1, wherein the curable compound used is dissolved in the liquid crystal substance used and fixes phase separation between the liquid crystal substance and the cured product upon curing. (6) The liquid crystal optical element according to claim 5, wherein the photocurable compound used is a photocurable vinyl compound. (7) The liquid crystal optical element according to claim 6, wherein the photocurable vinyl compound used is an acryloyl compound. (8) The liquid crystal optical element according to claim 7, wherein the photocurable vinyl compound used is an acrylic ester compound. (9) The liquid crystal optical element according to claim 8, wherein the photocurable vinyl compound used contains 15 to 70 wt% of an acrylic oligomer. (9) The liquid crystal optical element according to claim 1, wherein the electrode-attached substrate is a transparent electrode-attached substrate. (10) The liquid crystal optical element according to claim 9, wherein the substrate with transparent electrodes is a plastic substrate with transparent electrodes. (11) The liquid crystal optical element according to claim 9 or 10, wherein a protective plate is laminated on the outside of the transparent electrode-attached substrate. (12) The liquid crystal optical element according to claim 11, wherein the protective plate is bonded to the outside of both transparent electrode-attached substrates. (13) Claim 11 in which the protective plate is a glass plate
9. The liquid crystal optical element according to item 9. (14) A liquid crystal optical element according to claim 11, wherein the glass plates are bonded with polyvinyl butyral to form a laminated glass-like structure. (15) In a method for manufacturing a liquid crystal optical element in which a mixture containing a liquid crystal substance and a resin is supplied between a pair of electrode-attached substrates and the mixture is cured, the refractive index of the cured product obtained as the mixture is The ordinary refractive index (n
___o) using a mixture of a curable compound and a liquid crystal material selected to match either the extraordinary refractive index (n_e) or the refractive index when the liquid crystal material is randomly oriented (n_x); A method for manufacturing a liquid crystal optical element, characterized in that a spacer for controlling a substrate gap is held between a pair of electrode-attached substrates, a curable compound is cured, and phase separation between a liquid crystal substance and a cured product is fixed. (16) The refractive index of the obtained cured product is the ordinary refractive index (n_o) or the extraordinary refractive index (n_e) of the liquid crystal material used.
16. The method for manufacturing a liquid crystal optical element according to claim 15, wherein a curable compound selected to match the above is used. (17) A patent that uses a curable compound selected so that the refractive index of the resulting cured product matches the ordinary refractive index (n_o) of the liquid crystal material used, and a nematic liquid crystal material with positive dielectric anisotropy. A method for manufacturing a liquid crystal optical element according to claim 16. (18) A mixture of a curable compound and a liquid crystal substance is supplied onto one electrode-equipped substrate, and the other electrode-equipped substrate is further superimposed on the mixture, and then cured.
The method for manufacturing a liquid crystal optical element according to any one of Item 17. (19) A mixture of a curable compound and a liquid crystal substance containing a spacer for controlling the gap between the substrates is supplied onto one substrate with electrodes, and the other substrate with electrodes is placed on top of the mixture and pressurized, and then, The method for manufacturing a liquid crystal optical element according to claim 18, wherein the liquid crystal optical element is cured. (20) Supply a spacer for controlling the gap between the substrates before or after supplying the mixture of a curable compound and a liquid crystal substance onto one substrate with electrodes, and then stack the other substrate with electrodes on top of it and pressurize it, and then , Claim 1 to be cured
The method for manufacturing a liquid crystal optical element according to item 8. (21) The curable compound used is a photocurable compound and is cured by light exposure.
A method for manufacturing a liquid crystal optical element as described in 1. (22) The method for manufacturing a liquid crystal optical element according to claim 15, wherein the curable compound used is dissolved in the liquid crystal substance used, and the phase separation between the liquid crystal substance and the cured product is fixed upon curing. (23) The method for manufacturing a liquid crystal optical element according to claim 22, wherein the photocurable compound used is a photocurable vinyl compound. (24) The method for manufacturing a liquid crystal optical element according to claim 23, wherein the photocurable vinyl compound used is an acryloyl compound. (25) The method for producing a liquid crystal optical element according to claim 24, wherein the photocurable vinyl compound used is an acrylic ester compound. (26) Claim 25: The photocurable vinyl compound used contains 15 to 70 wt% of acrylic oligomer.
A method for manufacturing a liquid crystal optical element as described in 1. (27) After curing the curable compound and fixing the phase separation between the liquid crystal substance and the cured product, a protective plate is laminated on the outside of at least one transparent electrode-attached substrate.Claims 15 to 26 A method for manufacturing a liquid crystal optical element according to any one of paragraphs. (28) The method for manufacturing a liquid crystal optical element according to claim 27, wherein the protective plate is adhered to the outside of both transparent electrode-attached substrates. (29) Claim 27 in which the protective plate is a glass plate
29. A method for manufacturing a liquid crystal optical element according to item 28. (30) The method for manufacturing a liquid crystal optical element according to claim 29, wherein the glass plates are bonded with polyvinyl butyral and the two glass plates are integrated into a laminated glass shape.