JPH01269922A - Method for manufacturing liquid crystal optical elements - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a transmission-scattering type liquid crystal optical element, a method for manufacturing the same, and its use.

[Prior Art] In recent years, transmission-scattering control type liquid crystal has been developed, which uses a film-like liquid crystal layer in which the voids of a resin matrix are filled with a liquid crystal substance, and this film-like liquid crystal layer is sandwiched between a pair of electrode-equipped substrates. Optical elements are attracting attention.

11, GJ: raighhead et al. Appl, Ph
ys, Lett, 40(1) 22(198
2), which takes advantage of the characteristic that liquid crystal has refractive index anisotropy. Specifically, a porous body is impregnated with liquid crystal, and the refractive index of the liquid crystal is changed depending on whether or not a voltage is applied, thereby controlling transmission and scattering by adjusting the refractive index with the porous body. This method is a useful method that can overcome the drawbacks of the principle DS mode and PC mode without using a polarizing plate.

A similar device was created by J. L. Ferguson et al. using a nematic liquid crystal microencapsulated using polyvinyl alcohol (Publication No. 58-501631), and N. Pearlman et al. 60-252687), also J
, W., Doane et al. have created a method of dispersing and curing liquid crystal in an epoxy resin (Publication No. 502128/1983).

[Problems to be solved by the invention] H, G, (:Raighhead et al.'s method uses a method such as impregnation into a porous body, so the size of the pores and grooves in the porous body used varies, and the liquid crystal It is difficult to impregnate
Due to the problem that there is no flexibility in the ratio of the amounts of porous material and liquid crystal, there are drawbacks such as insufficient change in transmittance and difficulty in device fabrication.

Also, J.L. Ferguson et al. or N.P.
The device by Earlman et al. cures as moisture evaporates, so it cannot be cured while sandwiching two substrates, and there is no adhesion between the two substrates, and flatness cannot be achieved over a large area. It has been difficult to create devices with high

In addition, when trying to create an element with a change in the transmission-scattering state, these elements require evaporation of water during curing of the film-like liquid crystal layer, so the film-like liquid crystal layer is sandwiched between electrode-attached substrates. Therefore, the electrodes necessary for display had to be patterned.

In addition, in the device of J. W. Doane et al., when forming a film-like liquid crystal layer on a large-area substrate, an uncured film-like liquid crystal layer is coated and handled, which tends to result in insufficient control of its thickness. In particular, it has been extremely difficult to uniformly coat a film-like liquid crystal layer on a curved substrate.

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems, and includes a film-like liquid crystal layer formed by filling the voids of a resin matrix with a liquid crystal substance, which is attached to a pair of electrodes. In a liquid crystal optical element sandwiched between substrates, a film-like liquid crystal layer and a liquid crystal material.

The refractive index of the obtained cured product matches either the ordinary refractive index (no), the extraordinary refractive index (n8), or the refractive index (nx) when the liquid crystal material is randomly oriented. A latex consisting of a curable compound selected as above and compatible with the liquid crystal substance, and a polymeric substance selected so as to match the refractive index of the cured product of this curable compound is cured. A liquid crystal optical element characterized by forming a specific orientation in at least a part of its film-like liquid crystal layer so that the light transmission state changes less than other parts depending on whether or not a voltage is applied, or when a voltage is applied. A liquid crystal optical element forming a part in which the transmission state of light does not change regardless of the presence or absence of an applied voltage, a light control body consisting of the liquid crystal optical element and a driving means for applying a voltage thereto, and the liquid crystal optical element. An object display body consisting of an element, a driving means for applying a voltage thereto, and a placement means for arranging an object, and a display device that combines a plurality of liquid crystal optical elements and is provided with a driving means that can drive each one individually. It provides:

In addition, the refractive index of the liquid crystal material and the obtained cured product are the ordinary refractive index (no), the extraordinary refractive index (ne) of the liquid crystal material, or the refractive index when the liquid crystal material is randomly oriented ( nx) and is compatible with the liquid crystal substance, and a polymeric substance selected so as to match the refractive index of the cured product of this curable compound. Latex is supplied onto one electrode-equipped substrate, and water is evaporated to form a semi-cured film-like liquid crystal layer in which the voids in the polymer matrix are filled with a dissolved mixture of liquid crystal material and curable compound. , the other substrate with electrodes is placed on top of it and cured to fix the phase separation between the cured product of the curable compound and the liquid crystal material, and the liquid crystal material fills the voids in the matrix of the polymer material and the cured product. A method for manufacturing a liquid crystal optical element characterized by forming a film-like liquid crystal layer, and a method for manufacturing a liquid crystal optical element, which is characterized by forming a film-like liquid crystal layer, and applying a voltage to at least the electrodes of the portions to be kept in a specific orientation state, and the portions to be kept in a specific orientation state. Either mask the other parts and expose to light to cure, then remove the mask and cure the uncured parts without applying voltage, or mask the part you want to keep in a specific orientation and expose to light. It is characterized by curing the parts other than the parts to be kept in a specific orientation state, then removing the mask, and applying voltage to the electrodes at least in the parts to be kept in a particular orientation state, while hardening the uncured parts. A method for manufacturing a liquid crystal optical element is provided.

The device of the present invention uses a latex consisting of a liquid crystal substance, a curable compound that can be dissolved therein, and a polymeric substance, and uses two curing processes: a curing process of the polymeric substance by evaporation of water, and a curing process of the curable compound. Through this process, a structure is formed in which liquid crystal material is scattered in a matrix of a cured product made of a polymeric substance and a curable compound, and the distribution of liquid crystal and cured product is uniform, resulting in excellent appearance quality and productivity when purchased in bulk. It is something.

In the present invention, the refractive index of the cured product obtained by curing the curable compound is the ordinary refractive index (
no), the extraordinary optical refractive index (ne), or the refractive index when the liquid crystal material is randomly oriented (n8). Further, the refractive index of the polymer material is made to match the refractive index of the cured product obtained by curing the curable compound.

As a result, when the refractive index of the resin matrix of the formed film-like liquid crystal layer and the refractive index of the liquid crystal material filled in the voids match, light is transmitted, and when they do not match, light is scattered (cloudy). It turns out.

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 device of the present invention, the refractive index of the polymer material of the cured product and latex obtained by curing the curable compound constituting the resin matrix is greater than the refractive index of the liquid crystal material used.
o or n, when no voltage is applied, a scattering state (that is, a cloudy state) occurs due to the difference in refractive index between the unaligned liquid crystal material and the resin matrix, and the voltage When applied, the liquid crystal substance is aligned and the refractive index of the liquid crystal (no or ne) matches the refractive index of the resin matrix, indicating a transparent state, and it has a reversible dimming function. becomes.

The film-like liquid crystal layer of the device of the present invention is formed by two processes: a curing process of a polymeric substance by evaporation of water, and a curing process of a curable compound.
It is formed by going through two curing steps.

The present invention uses a mixture of a curable compound, a liquid crystal material, and a polymeric material. This mixture constitutes latex, and can be easily supplied to a substrate with electrodes to form a thin film, and even if supplied to a large area, it can be made to have a relatively uniform thickness.

In the first half of the curing process, the water in the latex evaporates to harden the polymeric substance.The polymer constitutes a matrix, and a dissolved mixture of liquid crystal material and curable compound is formed in the voids of the matrix. A semi-cured film-like liquid crystal layer with a filled structure is formed. In this state, since the refractive indexes of the two do not normally match, a scattering state occurs.

In the second half of the curing step, the other electrode-attached substrate is placed on top of this semi-cured film-like liquid crystal layer, and the curable compound is cured by heating, light exposure, or the like. As a result, the curable compound, which was uncured in the previous step, phase-separates from the liquid crystal material and hardens, forming a matrix together with the already hardened polymer material.

In this state, the refractive index of the cured product made from the curable compound and the polymer are made to match, so as mentioned above, the refractive index of these resin matrices and the refractive index of the liquid crystal material match. Otherwise, this film-like liquid crystal layer will be in a scattering state.

In the present invention, during the latter curing process, a specific orientation is formed by curing with voltage applied only to specific portions.

Usually, by curing the material while applying a voltage equal to or higher than the threshold voltage, that portion always becomes light-transmissive.

However, depending on the system of the curable compound and liquid crystal substance used, there are differences in orientation formation in response to this applied voltage, so even if a voltage higher than the threshold voltage is applied, the light transmitting state may not always be achieved. A voltage sufficiently higher than the threshold voltage should be applied, and the composition of the system should be appropriately selected.

After curing, this portion almost transmits light regardless of voltage application. This makes it possible to display specific characters and figures without patterning the electrodes. Furthermore, it becomes possible to easily surround characters, figures, graphs, etc. with a continuous frame, and there is also an advantage that the degree of freedom of display and the ease of designing display patterns are improved.

Other areas that are cured with no voltage applied or with a low voltage applied will allow light to pass through to some extent in areas where voltage was applied but only for a short period of time, and the light transmittance will increase due to the application of voltage. begins to change.

In this case, the liquid crystal substance is cured by light exposure while applying a voltage that does not completely align the material, or by applying a voltage and exposing to light for a short time to the extent that curing progresses to some extent. In this case, the liquid crystal molecules will be oriented on average at approximately a certain angle to the substrate surface.

As a result, the light transmittance in a state where no voltage is applied is higher than that of the surrounding cloudy part, and it becomes possible to display halftones. This makes it possible to display images like photographs.

If you want to display halftones like a photograph, you can easily create a photographic tone by using a photocurable compound and exposing it to light using a photographic negative or positive while applying a high voltage. A liquid crystal optical element can be obtained.

As a result, areas that are strongly hit by light are always in a transparent state, and the less the amount of light hits, the more intense the scattering becomes. This allows various intermediate tones to be produced depending on the amount of light transmitted. Scattering and transmission of the scattered portion can be controlled by applying a voltage.

In order to form a portion through which light always passes according to the present invention, the threshold value of the liquid crystal of the liquid crystal optical element in the portion obtained by curing while applying a voltage to form a specific orientation is The dielectric constant value (ε) measured below a voltage and the dielectric constant measured in two states of the liquid crystal optical element in the part cured without applying a voltage, that is, (1) the liquid crystal is sufficiently perpendicular to the substrate. Dielectric constant (ε.H) measured at a voltage that allows alignment (2) Dielectric constant (ta) measured at a voltage below the threshold voltage of the liquid crystal
It is preferable that the relational expression with rr) is as follows.

Note that if the transmittance is increased in the scattering state instead of always in the transmitting state using the method described above, the transmission-scattering can be controlled by applying or not applying voltage, and the response speed of transmission-scattering is faster. There is a tendency for the drive voltage to decrease.

For this reason, there is also a method of use in which a voltage is applied to cure the curable compound to form a specific orientation within a range where the transmittance in the scattering state is not too high. In this case, a voltage is applied to the film-like liquid crystal layer on the entire surface of the device to harden it.

In particular, the transmittance increases when the liquid crystal is oriented perpendicularly to the substrate surface when a voltage is applied, so the resin matrix, i.e., the polymer substance and curable compound that make up the latex, harden. It is preferable to use a combination of a photocurable compound selected so that the refractive index of the cured product matches the no of the liquid crystal material used, and a liquid crystal material with positive dielectric anisotropy.

In addition, the element of the present invention is such that the refractive index of the cured product of the curable compound and the refractive index of the polymeric material match the refractive index (n8) when the liquid crystal material used is randomly oriented. It can also be used as a gift.

Random alignment here means that all liquid crystal molecules are not aligned parallel or perpendicular to the substrate surface.
This indicates that the cured product is oriented in various directions due to the influence of the networks or capsules that make up the matrix. In this case, when no voltage is applied, the refractive index of the unaligned (randomly oriented) liquid crystal material and the resin matrix match, and therefore a transmissive state is exhibited.

Conversely, when a voltage is applied, the liquid crystal material aligns, and the refractive index of the liquid crystal (no or na) no longer matches the refractive index of the resin matrix, resulting in a scattering state (that is, a cloudy state). .

As a result, a transparent element can be obtained without applying a voltage, but the resin matrix exists in a network or capsule shape, and the liquid crystal is influenced by the cured product of this resin matrix and is oriented randomly. Because of this, there are interlayer points where it is difficult to achieve a uniform state.

When oriented vertically or horizontally as in the former case, it is easy to achieve uniform alignment, but when oriented randomly, even if it is random from a macroscopic point of view, when viewed partially, it is difficult to align it uniformly. This is because the condition is slightly different, resulting in a difference in refractive index, which tends to appear uneven.

As in the case described above, this type of element is cured by applying a voltage higher than the threshold voltage only to a specific part during the second half of the curing process of the curable compound. can always be in a scattered state.

After curing, light is scattered in this portion regardless of voltage application. This makes it possible to display specific characters and figures without patterning electrodes.

Also, in the case of this element, the liquid crystal substance is cured by light exposure while applying a voltage that does not completely align the material, or it is cured by light exposure for a short time to the extent that curing progresses to a certain extent while applying a voltage. By curing or the like, the liquid crystal molecules can be oriented at an approximately certain angle to the substrate surface when viewed on average. This makes it possible to display halftones like photographs and to drive at low voltages.

In this case as well, since there are differences in orientation formation in response to applied voltage depending on the system of the curable compound and liquid crystal substance used, it is preferable to determine the applied voltage experimentally depending on the desired orientation state.

In addition, in the present invention, the refractive index of this resin matrix and the refractive index of the liquid crystal material used (any of no, n, and nyo) are made to match, but this matching does not mean making them completely match. is preferable, but it suffices if they match closely to the extent that the transmission state is not adversely affected.

Specifically, the difference between the refractive index of the latex polymer material, the refractive index of the curable compound, and the refractive index of the liquid crystal material is reduced to 0.
．． It is preferable to keep it at about 15 or less. This is because the polymer material or cured material swells with the liquid crystal material, and the refractive index of the polymer material or cured material approaches the liquid crystal material's refractive index than the original refractive index of the polymer material or cured material, so even if there is a difference of this degree, , almost all light is transmitted.

In the present invention, as the curable compound, there can be used a compound that does not cure when the latex polymer substance is cured by evaporation of water, but is cured by heat, light, etc. thereafter. In particular, photocurable compounds have a short curing time and are highly productive, and can easily form a specific orientation in a desired area without patterning the electrodes by simply blocking light with a mask and displaying a fixed display. can form a part.

In other words, by placing a light-blocking mask on the surface of the substrate, it is easy to harden only specific areas and form a specific orientation, creating a fixed display in which light always passes through or is scattered. can form a part.

This photocurable compound may be any compound that can be cured by infrared rays, visible rays, ultraviolet rays, or electron beams, and the action of light may be of any kind as long as it promotes curing, whether by photons, electrons, or heat. But that's fine.

Therefore, the photocurable compound may be any one of vinyl polymerization, addition polymerization, condensation polymerization, cationic polymerization, anionic polymerization, living polymerization, etc., but may contain substances that may deteriorate liquid crystal materials such as moisture and corrosive substances. Condensation polymerization that generates is generally unfavorable.

Alternatively, after photocuring with a mask, the whole may be heated to perform thermal polymerization.

When using a photocurable compound, if you want to speed up the curing speed, you can add a photocuring initiator, etc. If the compound can be photocured by radical species, you can create an element with excellent appearance quality and reliability. can do.

This photocurable compound may be one in which the compound itself is photoreactive, or one in which curing is induced by a substance generated by light irradiation, and can be roughly divided into those that decompose and harden due to light irradiation, and those that cure by polymerization. It is classified as something that does.

Typical of these compounds include photocurable acrylic monomers and oligomers, specifically monoacrylates, diacrylates, N-eta acrylamide, N-vinylpyrrolidone, styrene and its derivatives,
polyol acrylate, polyester acrylate,
Monofunctional and polyfunctional vinyl groups represented by urethane acrylate, epoxy acrylate, silicone acrylate, fluoroalkyl acrylate, polyacrylate with a polybutadiene skeleton, polyacrylate with an isocyanuric acid skeleton, acrylate with a hydantoin skeleton, unsaturated cycloacetal, etc. A compound having the following is exemplified.

In particular, among photocurable compounds, the use of acrylic compounds provides excellent phase separation and uniformity of the liquid crystal and cured product after exposure to light, and also provides fast curing speed upon exposure to light. This is preferred because the product is stable.

In addition, the curable compounds may be used alone or in combination, and include modifiers necessary for device creation, modifiers for the created device, etc. Specifically, crosslinking agents, surfactants, diluents, It may contain thickeners, antifoaming agents, 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 and solubility with the liquid crystal.

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

The liquid crystal materials used in the present invention include nematic liquid crystal materials,
There are smectic liquid crystal substances, and they may be used alone or as a composition, but it is more advantageous to use a composition in order to satisfy various required performances such as operating temperature range and operating voltage. In particular, it is preferable to use nematic liquid crystal.

In addition, it is preferable that the liquid crystal substance used be uniformly dissolved in the curable compound, and the cured product after exposure to light must be one that does not dissolve or is difficult to dissolve, and when using a composition, individual It is desirable that the solubility of the liquid crystal material be as close as possible.

The polymeric material constituting the latex used in the present invention may be any material as long as it contains a solution of the liquid crystal material and a curable compound and forms a stable latex. Specifically,
Vinyl polymers include polyvinyl acetate, polystyrene, polyethylene, polyvinyl chloride, acrylic copolymers,
Vinyl acetate polymers, redene chloride copolymers, vinyl chloride copolymers, etc., and synthetic rubbers such as polyisobutylene,
Chloroprene rubber, polybutadiene rubber, SBRSNB
In addition to RlMBR, examples include polyurethane, polyepoxy, polysiloxane, etc., and various additives may be included to ensure the stability of the latex.

The polymeric substance in this latex hardens (hardens, not polymerizes) by evaporating water.
Forms the framework of the resin matrix.

When manufacturing the device of the present invention, the total amount of the curable compound and the polymeric substance and the amount of the liquid crystal substance are in a weight ratio of 5:95 to 7.
A mixture of about 5:25 may be used, and it may be used as a liquid viscous substance. In this case, the weight ratio of the curable compound and the polymeric substance may generally be about 10:90 to 90:10.

The method for manufacturing the device of the present invention will be exemplified below.

First, a polymer material constituting latex is added to a dissolved mixture of a curable compound and a liquid crystal material to form a stable latex mixed therewith. In this latex, a dissolved mixture of a liquid crystal substance and a curable compound is dispersed in a polymeric substance dispersed in water.

This latex, IIn203-3no (IT
The liquid crystal layer is supplied onto a transparent electrode-equipped glass substrate such as O) or Snow by a method such as roll coating, spin code, or printing, and moisture is evaporated to form a film-like liquid crystal layer in a semi-cured state. In this state, in the film-like liquid crystal layer, the polymer material hardens to form a resin matrix framework, and a dissolved mixture of the liquid crystal material and the curable compound exists dispersed in the voids.

Next, an opposing substrate with electrodes is placed on top of this semi-cured film-like liquid crystal layer, and the curable compound is cured by light exposure or heating. As a result, the dissolved mixture of the liquid crystal material and the curable compound, which had been dispersed in the voids of the framework of the resin matrix in which the polymer material had hardened, was removed.
The curable compound is cured and phase-separated from the liquid crystal substance, forming a film-like liquid crystal layer in which the liquid crystal substance is dispersed in the voids in the resin matrix made of the polymer substance and the cured product of the curable compound.

When the curable compound is cured, the compound may be cured while applying pressure, or may be cured while the substrate is curved, or may be cured while applying a voltage, if necessary.

Alternatively, the curable compound may be cured without overlapping the other electrode-equipped substrate, and the other electrode-equipped substrate may be bonded after curing.

The thickness of the film-like liquid crystal layer in this cured state is 5 to 5.
It can operate at 100μI, but if you take into account the applied voltage and the on/off contrast, it can be operated at 7 to 40μI.
It is appropriate to set it to .

In this way, first the polymeric substance in the latex is cured, and then the curable compound is cured to form a film-like liquid crystal layer.

In this case, if the refractive index of the cured product, to be more precise, the refractive index of the cured product and polymeric material constituting the resin matrix, and the 00 or n of the liquid crystal material are made to match, the alignment will not occur after curing. A cloudy state occurs due to refractive index scattering due to the liquid crystal material and the resin matrix. In the device of the present invention thus produced, when a voltage is applied, the liquid crystal material is aligned, and the refractive index of the resin matrix matches the refractive index of the aligned liquid crystal material, so that the element becomes transmissive.

In the present invention, when it is desired to produce a specific orientation of a fixed display, the curable compound is cured while applying a voltage only to this portion.

There are various methods for producing this specific orientation, but it is preferable to use a photocurable compound as the curable compound and to perform light exposure because of good productivity, and examples thereof are shown below.

■ Arrange electrodes that correspond to the pattern in specific areas, apply voltage between them, and expose the entire area to light to cure it.

■A light-shielding mask is formed on areas excluding specific areas, and while a voltage is applied to at least the specific areas, light is applied to the entire area to cure only the specific areas, and then the light-shielding mask is removed. to cure the remaining part.

(2) While scanning with a laser or the like, voltage is applied to the necessary areas to form a specific orientation only in specific areas.

Further, the process may be reversed so that the parts excluding the particular parts are cured first by combining these methods or by using a mask having the same shape as the particular parts.

In particular, the process (1) and its reverse process can use electrodes for driving non-patterned elements previously formed on the substrate, and only a mask is required as an additional means, resulting in good productivity.

It is also possible to adopt the structure of a normal liquid crystal optical element cell with electrodes formed on the inner surface, and use the electrodes to create a specific pattern with a specific orientation, or to place electrodes on the outside and thereby create a specific pattern. may be oriented in a specific manner. By these, for example, it is possible to combine figures in a dot matrix display, segment display, bar graph display, or form a continuous frame.

In addition, for example, by using a disk-shaped glass substrate cell with ITO on the entire surface, rotating it at the center, and then writing with a laser beam or the like using the method (2), it can be used as a memory element.

Furthermore, as mentioned above, by changing the voltage during curing stepwise around the threshold voltage, and controlling the light irradiation time, curing temperature, etc., the transmittance changes depending on the voltage, although the white turbidity is low. It is also possible to form a transmissive part with a half tone.

The device created in this way has a part where light always passes through due to a specific orientation, and a part that is usually cloudy or slightly cloudy, but by applying a voltage, the liquid crystal aligns and the cured product becomes It has a portion where the transmittance changes because the refractive index of the liquid crystal matches the refractive index of the liquid crystal and becomes a transparent state.

In addition, by appropriately selecting the system of the curable compound and liquid crystal material, the applied voltage, the intensity of light, etc., it is possible to reduce the degree of cloudiness when the voltage is turned off without narrowing the transmission-scattering control range too much. It is also possible to increase the response speed or lower the drive voltage without lowering the voltage.

In addition, the refractive index of the resin matrix is set to the refractive index of the liquid crystal material (
nx), the refractive index of the liquid crystal material that is not aligned after curing matches the refractive index of the resin matrix, resulting in a transparent state. When a voltage is applied to the device thus produced, the liquid crystal material is aligned, and the refractive index of the resin matrix and the aligned liquid crystal material are shifted from each other and scattered, resulting in a cloudy state.

In this case, if a specific orientation is formed, light will always be scattered in that part.

Of course, in this case, as in the case described above, it is also possible to form a halftone portion, increase the response speed, and lower the driving voltage.

In the present invention, a dichroic dye, a simple dye, or a pigment is added to this liquid crystal, a colored material is used as a polymer substance or a curable compound, a colored substrate is used as a substrate,
You can also add a specific color by applying a color filter.

In the present invention, latex is supplied to the substrate, water is evaporated, and the polymer is cured to a semi-cured state, so it can be quickly supplied to a large area and the thickness can be made uniform relatively easily. .

The curable compound is then cured to separate the liquid crystal material by phase separation, completing the curing of the film-like liquid crystal layer. During this latter half of curing, there is no need to simply evaporate the solvent or water. Therefore, it can be cured in a closed system, making it highly reliable.
In addition, since the photocurable compound also has the effect of bonding two substrates together, a sealant can be made unnecessary. Also,
In this step, since both substrates can be held in a pressurized state, the gap between the substrates can be further made uniform. At this time, even if the pressurizing pressure is strong, a resin matrix made of polymeric substances has already been formed, so there is less risk of short circuit between the substrates, and productivity is good. Therefore, the semi-cured film-like liquid crystal layer By bending a substrate having a curved surface and then performing the latter half of the curing process, it is possible to easily manufacture an element using a curved substrate. Further, as described above, it is also possible to easily form a specific orientation in a specific portion to display a fixed display.

In the present invention, the electrode-attached substrate may be a substrate made of glass, plastic, etc., on which transparent electrodes such as ITO, 5n02, etc. are formed. Of course, it is possible to form an insulating layer between the substrate and the electrodes, or to use low-resistance metal lead wires for the electrodes.
A mirror electrode may be formed on one electrode, or non-glare dust may be formed on the front side of the substrate. In particular, by using a plastic substrate as the substrate, a long liquid crystal optical element using a continuous plastic film can be easily manufactured.

By sandwiching a film-like liquid crystal layer between such electrode-attached substrates, even if the area is large, the risk of short-circuiting 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.

In addition, in the element of the present invention as well, in order to reduce unevenness in the state of light transmission, it is preferable that the gap between the substrates is constant to some extent. For this reason, it is preferable to arrange a spacer for controlling the gap such as glass particles, plastic particles, ceramic particles, etc. in the gap between the substrates. Specifically, it is preferable to supply a spacer for controlling the substrate gap in the latex on the substrate. Alternatively, the spacer may be supplied before or after the latex is supplied, and then the water can be evaporated.

In this case, by applying pressure after stacking the other substrate and then curing the curable compound, a more uniform gap between the substrates can be easily achieved.

Although such a liquid crystal optical element can be used as a display element, it is suitable for use as a light control body because it can be easily made into a large area and can be cut into a desired size later. . When used as a light control body,
Since it is usually a transmission type, 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 material f'1 such as polyvinyl butyral is placed between two glass plates that are slightly larger than the liquid crystal optical element. Sandwiched through the layers,
It is preferable to cure the adhesive material layer by heating or light irradiation to integrate the liquid crystal optical element and the glass plate to form a laminated glass. In particular, by using polyvinyl butyral as the adhesive material, it is possible to It can have a structure very similar to 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 light control bodies using this liquid crystal optical element 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 products. Available for use.

When used as a light control body, this liquid crystal optical element is
A driving means for driving this may be added. As this driving means, one that can normally apply an alternating current voltage of about several tens of volts is used, as will be described later.

In addition, by combining this liquid crystal optical element with arrangement means for arranging various objects and adding a driving means to drive it, it can be used in object display bodies such as show windows and showcases for displaying various products. You can also. This has applications such as being used for files so that the title of the file cannot be seen unless a voltage is applied to make it transparent, and the presence or absence of a file can always be confirmed by the transparent part.

Furthermore, by combining a plurality of liquid crystal optical elements of the present invention, each of which can be driven individually, it can be used for a display device that displays characters and figures. By arranging the kanji characters so that the kanji characters are displayed, it becomes possible to create a large-sized display device with 111 or more characters per character, which was not possible with conventional liquid crystal display elements.

When applying a voltage for driving the liquid crystal optical element of the present invention, it is sufficient to apply an AC voltage that changes the alignment of the liquid crystal.
An alternating current voltage of about 0.011z may be applied.

Furthermore, when no voltage is applied, the electrodes may be opened or short-circuited. Among these, by making the impedance between the electrodes, that is, the total impedance of the electrode impedance, the connection impedance at the terminal part, and the circuit impedance, lower than the impedance of the liquid crystal material and the waste of the cured material, The LCD responds quickly when the voltage is turned off.

In particular, it is preferable that the impedance between the electrodes or the impedance of the layer of the liquid crystal material and the cured material be 1710 or less. 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 charges accumulated between the electrodes are quickly discharged. The movement of the liquid crystal returning to its random orientation is not inhibited, and the change between transmission and scattering becomes faster.

The device of the present invention can be used for display devices, especially large 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, light shutters, etc. It is possible to use

It can also be installed in front of a light source such as a light bulb and used to electrically switch between fog lamps and regular lamps, for example.

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

In addition, 1111 can be used in conjunction with color filters or mixed dichroic dyes into the liquid crystal to create colors, and can be used with other displays such as TN liquid crystal display elements, electrochromic display elements, electroluminescent display elements, etc.
It may also be used as a base material, and various applications are possible.

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

Example 1 2 parts of n-butyl acrylate, 4 parts of 2-hydroxyethyl acrylate, 3 parts of acrylic oligomer (rM-62QOJ manufactured by Toagosei Kagaku Co., Ltd.), liquid crystal (BD
18 parts of rE-8J (manufactured by H Company) and 0.18 parts of a photocuring initiator (GloCure 1116J, manufactured by Merck & Co., Ltd.) were added and uniformly dissolved. Neil DLS J
) 3.1 g, and was diffused using a diffusion device (Yamato f, ``!, ni-21'' manufactured by '1 Gakusha) to prepare a stable latex.

This latex was applied onto an ITO-attached polyester substrate, and water was evaporated to form a semi-cured film-like liquid crystal layer having a thickness of about 20 μm.

Next, as the other substrate, a polyester substrate with ITO was superimposed and exposed to light for about 5 minutes using an ultraviolet irradiation device (Toscure 4004 manufactured by Toshiba Corporation) to complete curing.

The entire surface of this element was cloudy in this state. When an AC voltage of 50 Hz and 80 V was applied to this element, the entire surface became transparent.

In addition, as the other substrate, after superimposing a polyester substrate with ITO, 1, cut out a T-shaped black tape and paste it as a light-shielding mask, and cover the entire cell with 5011z, 6
Using an ultraviolet irradiation device while applying an AC voltage of 0V,
After exposure for about 1 minute, the mask was removed and exposure was carried out for about 5 minutes using an ultraviolet irradiation device to complete curing.

In this state, this element had a T-shaped transparent part and other parts were cloudy.

When an AC voltage of 30 VAC (501 (Z)) was applied to this element, the entire surface became transparent.

Example 2 1 part of n-butyl acrylate and 5 parts of 2-hydroxyethyl acrylate were mixed with a liquid crystal (rE-8J manufactured by BDH).
) and 0.12 parts of benzoin isopropyl ether as a photocuring initiator were added and uniformly dissolved. A stable latex was prepared using this solution in the same manner as in Example 1.

This latex was applied onto an ITO-attached polyester substrate, and water was evaporated to form a semi-cured film-like liquid crystal layer having a thickness of about 20 μm.

Next, as the other substrate, a polyester substrate with ITO was superimposed and exposed to light for about 3 minutes using an ultraviolet irradiation device (Toscure 400, manufactured by Toshiba Corporation) to complete curing.

The entire surface of this element was cloudy in this state. When an AC voltage of 5011z and 80V was applied to this element, the entire surface became transparent.

In addition, as the other substrate, after superimposing the polyester substrate with ITO, 1, cut out a T-shaped black tape and paste it as a light-shielding mask, and apply 50 tlz to the entire cell, 6
Using an ultraviolet irradiation device while applying an AC voltage of 0V,
After exposure for about 1 minute, the mask was removed and exposure was carried out for about 3 minutes using an ultraviolet irradiation device to complete curing.

In this state, this element had a T-shaped transparent part and other parts were cloudy.

When an alternating current voltage of 30 VAC (50 Hz) was applied to this element, the entire surface became transparent.

Example 3 Using the same element as in Example 1, it was sandwiched between two black light-shielding plates with two polyvinyl butyral films interposed therebetween, and was integrated by heating and pressurizing in an autoclave.

The device imaged in this way was safe to external pressure and highly reliable.

Example 4 Light exposure was carried out in the same manner as in Example 1, using a photographic negative as a mask instead of the black tape with the letter T cut out in Example 1 as a light-shielding mask, and then voltage was applied. The device was fabricated by performing light exposure without any oxidation.

When an alternating current voltage (Δcaov, 5011z) was applied to this element, the entire surface became transparent, and when the voltage was removed, an image with halftones ranging from transparent parts to cloudy parts was obtained.

Example 5 A device was manufactured in the same manner as in Example 1, using a pattern of a person skiing as a mask pattern.

This element was installed in front of a show window in which ski equipment was placed. When no voltage is applied to this show window, the pattern of the figure of a person skiing appears cloudy, or the alternating current voltage (AC80V, 501iz
), the entire surface became transparent.

Example 6 A gXU device was fabricated in the same manner as in Example 1, using a pattern of circular holes as a mask pattern.

This element was used as a light control body for a door. When no voltage is applied to this door, the inside is visible only through the round hole, and when an AC voltage (AC80V, 5011Z
), the entire surface became transparent. This allows the interior of the door to be seen only through the round hole when it is in use, and when not in use, the door is completely transparent and can be seen at a glance.

Example 7 A device was manufactured in the same manner as in Example 1, using a pattern with rectangular holes as a mask pattern.

This element was used as a light control body and as a glass door for a file shelf. When no voltage was applied to this glass door, the width of the file shelf was visible only through the rectangular hole, but when an AC voltage (80V, 5011z) was applied to it, the surface of the glass door became transparent. .

As a result, it is possible to make it possible to always see the file number, etc. of a file placed in the file folder that may be seen by others, but to make the file title visible only when a voltage is applied.

Example 8 A square mask with a frame cut out around the periphery was used as the mask pattern, and the device was subjected to WA treatment in the same manner as in Example 1.
Built.

A dot display type display device was created by using 8×8 elements to display one character.

In this display device, the area around each dot is always transparent and light passes through it, but the area around each dot is
When 11z) was applied, only the applied dots became completely transparent and a display was made.

[Effects of the Invention] As described above, the present invention provides a novel liquid crystal optical element and a method for manufacturing the same, and the refractive index of the obtained cured product is the ordinary refractive index (no) of the liquid crystal material used, A curable compound selected to match either the extraordinary optical refractive index (ne) or the refraction 1 (ne) when the liquid crystal material is randomly oriented, a liquid crystal material, and a polymeric material are mixed. A semi-hardened film-like liquid crystal is created by using latex, first evaporating the water to harden the polymer, and then filling the voids in the resin matrix of the polymer material with a dissolved mixture of the hardening compound and the liquid crystal material. This is an element in which a layer is formed and then a curable compound is cured to fix the phase separation between the liquid crystal material and the cured product. Therefore, the present invention does not require a polarizing plate, provides an element with excellent appearance quality and productivity, and can easily provide an element with a large area and uniform performance.

In the present invention, compared to obtaining a film-like liquid crystal layer by simply using a mixed solution of a liquid crystal material and a curable compound that can be dissolved in the liquid crystal material, the film thickness can be easily made uniform even over a large area, and the film thickness can be easily made even over a large area. It can also be easily applied to printed circuit boards.

In addition, compared to obtaining a film-like liquid crystal layer using latex made only of a liquid crystal substance and a polymer substance, since the substrate can be hardened by applying pressure in a post-process, it is easier to obtain a uniform film thickness, and It has the advantage that it can achieve a fast curing speed similar to that of light exposure, has good productivity, and has the ability to bond two substrates by itself. Furthermore, by partially curing the material while applying a voltage, a specific orientation can be formed in a portion, and a fixed display can be easily obtained.

In particular, when curing the curable compound, a voltage is applied between at least a portion of the substrate to produce a specific orientation, which is useful for display purposes, especially for large area and curved displays, and for large area and curved displays. It can be widely used for dimming, light shutter, etc.

In particular, it is possible to fix the phase separation between the liquid crystal substance and the cured material by holding the substrate between a pair of electrode-attached substrates, using a photocurable compound as the curable compound, and curing the photocurable compound by exposure to light. This is preferable because the curing time is short, productivity is extremely high, and a specific fixed display can be easily obtained using only a mask.

Further, by patterning using a mask with a specific pattern, there is an advantage that curing of this specific portion and curing of the remaining portion can be performed successively using the same device.

Furthermore, specific characters and figures can be displayed without patterning electrodes. Furthermore, it becomes possible to easily surround characters, figures, graphs, etc. with a continuous frame, and there is also an advantage that the degree of freedom of display and the ease of designing display patterns are improved.

In addition, when photocuring is performed while applying a voltage near the threshold voltage, or when curing is performed by exposing to light for a short time while applying a voltage, the light is not completely transmitted, but the surrounding It is also possible to form areas that allow light to pass through or are cloudy compared to the masked areas. This makes it possible to display intermediate tones that are not binary, transparent or cloudy.

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, a latex mixed with a liquid crystal material, a curable compound, and a polymeric material is supplied onto a substrate, the moisture is evaporated, the polymeric material is cured, and the other substrate is placed on top of the latex and exposed to light. By heating and curing the curable compound, uniform, large-area devices can be manufactured with extremely high productivity. Therefore, even when the substrate is glass, a fairly long substrate can be used, and when the substrate is plastic, a continuous process using a continuous film is also possible.

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

In addition to this, the present invention can be applied in various other ways without detracting from the effects of the present invention.

Claims (7)

[Claims] (1) In a liquid crystal optical element in which a film-like liquid crystal layer formed by filling voids in a resin matrix with a liquid crystal substance is sandwiched between a pair of electrode-attached substrates, the film-like liquid crystal layer
The refractive index of the liquid crystal material and the obtained cured product are the ordinary refractive index (n_o), the extraordinary refractive index (n_e), or the refractive index (n_x) when the liquid crystal material is randomly oriented. A latex made of a curable compound selected to match the liquid crystal substance and compatible with the liquid crystal substance, and a polymeric substance selected to match the refractive index of the cured product of the curable compound. A liquid crystal optical element characterized by: (2) Forming a specific orientation in at least a part of the film-like liquid crystal layer so that the state of light transmission changes less depending on whether or not a voltage is applied than other parts, or regardless of whether or not a voltage is applied. 2. The liquid crystal optical element according to claim 1, further comprising a portion where the state of light transmission does not change. (3) A light control body comprising the liquid crystal optical element according to claim 1 or 2 and a driving means for applying a voltage to the liquid crystal optical element. (4) An object display body comprising the liquid crystal optical element according to claim 1 or 2, driving means for applying a voltage thereto, and arrangement means for arranging an object. (5) A display device in which a plurality of liquid crystal optical elements according to claim 1 or 2 are combined and provided with driving means capable of individually driving each of the liquid crystal optical elements. (6) In a method for manufacturing a liquid crystal optical element, in which a film-like liquid crystal layer formed by filling voids in a resin matrix with a liquid crystal substance is sandwiched between a pair of electrode-attached substrates, the liquid crystal substance and the obtained cured product are The refractive index is the ordinary refractive index (n_o), the extraordinary refractive index (n_e) of the liquid crystal material, or the refractive index when the liquid crystal material is randomly oriented (n_x
) and a curable compound that is compatible with the liquid crystal substance, and a polymeric substance that is selected to match the refractive index of the cured product of this curable compound. is supplied onto one electrode-attached substrate, and water is evaporated to form a film-like liquid crystal layer in a semi-cured state in which the voids in the matrix of the polymeric material are filled with a dissolved mixture of the liquid crystal material and the curable compound. The other substrate with electrodes is placed on top of the other substrate and cured to fix the phase separation between the cured product of the curable compound and the liquid crystal material, and the liquid crystal material is filled into the voids in the matrix of the polymer material and the cured product. 1. A method for manufacturing a liquid crystal optical element, comprising forming a film-like liquid crystal layer. (7) While applying a voltage to at least the part of the electrode that you want to keep in a specific orientation state, mask the part other than the part you want to keep in a specific orientation state, and cure it by exposing it to light, then remove the mask and apply the voltage. 7. The method for manufacturing a liquid crystal optical element according to claim 6, wherein the uncured portion is cured without applying any voltage. (8) Mask the part you want to keep in a specific orientation state, expose to light to harden the parts other than the part you want to keep in the specific orientation state, then remove the mask, and at least mask the part you want to keep in the specific orientation state. 7. The method for manufacturing a liquid crystal optical element according to claim 6, wherein the uncured portion is cured while applying a voltage to the electrode.