JP2780284B2 - Manufacturing method of dimmer for vehicle - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a vehicle light control body in which at least a part of a light transmission state changes by application of a voltage.

[Related Art] In recent years, a colored portion is provided above a windshield of an automobile or a side glass of a bus in order to prevent sunlight from entering a vehicle such as an automobile and secure a visual field of a driver or the like. Have been.

For example, a partially dyed polyvinyl butyral film sandwiched between two glass plates and vitrified, or a glass surface partially printed with a pattern is known.

Many of these have a so-called blurred portion in which the color gradually changes between a colored portion and a non-colored portion.

However, since the optical properties of these partially colored glasses are fixed, the colored portions become invisible or extremely difficult to see at night or in darkness. Further, there is a disadvantage that the change cannot be made even when it is desired to take in sunlight in a cold season or the like.

On the other hand, twisted nematic (TN) liquid crystals and guest hosts (G
H) There are liquid crystal display devices using liquid crystals and electrochromic devices using electrochromic (EC) materials.

Therefore, it has been proposed to use these elements for controlling the transmission state of light in the partially colored glass for vehicles.

[Problems to be Solved by the Invention] However, it is difficult to manufacture a TN liquid crystal element having a large area and a uniform substrate gap, and since a polarizing film is used, the TN liquid crystal becomes considerably dark even in a transmission state. In addition, it is extremely difficult to provide a so-called blur whose transmission state changes gradually.

Also, it is difficult to manufacture GH liquid crystal elements with a large area and uniform substrate gap, and there are many dyes used that are weak to direct sunlight, and there is a doubt about durability. It was extremely difficult to put on.

EC devices can be easily blurred by gradually reducing the thickness of the EC material layer.However, large-area devices are still difficult to manufacture and are current-driven devices. In the case of the element, the drive current becomes large, and when an electrode having a high resistance value such as a transparent electrode is used, there is a problem that the response becomes extremely slow and it takes several minutes or more. .

For this reason, there has been a demand for a light control body which is combined with a transparent body for a vehicle having a large area such as a windshield of an automobile to provide a light control function having a blurred pattern.

Means for Solving the Problems The present invention has been made to solve the above-mentioned problem, and is a vehicle for a vehicle, wherein at least a part of a transparent state of the vehicle is changed by application of a voltage. in the method for manufacturing use light adjuster, the refractive index of the resulting cured product, the refractive when ordinary refractive index of the liquid crystal material to be used (n _o), the extraordinary refractive index (n _e) or a liquid crystal material is randomly oriented When a mixture of a photocurable compound and a liquid crystal material forming a cured product matrix selected to match any one of the ratios ( _nx ) is sandwiched between a pair of electrode-attached substrates, and when the whole is photocured, ,
A part thereof is cured while applying a voltage, and a method of manufacturing a vehicle light control body characterized in that a part where a transmission state gradually changes is formed, and when the whole is photocured, a part thereof is partially cured. It is intended to provide a method for producing a vehicle light control body, characterized in that a photocurable compound as a raw material of a cured product is cured under different temperature conditions to form a portion where a transmission state is gradually different. .

In the present invention, the dimmer is a dimmer that controls transmission-scattering by voltage using an electro-optical medium such as a liquid crystal, and is a dimmer having a portion where transmission states are gradually different. By the voltage control, it is possible to easily make the whole completely transmissive, or to have a part in which the transmissive state gradually changes, that is, a state having a so-called blurred part.

In the present invention, a dimmer which controls transmission-scattering by a voltage has a portion where a transmission state is gradually different in a state where a sufficiently high voltage or a certain voltage is applied or in a state where a voltage is not applied. Any dimmer can be used.
Specifically, an element using liquid crystal is preferable in terms of current consumption, and in particular, an element in which a film-like liquid crystal layer in which a liquid crystal substance is dispersed and held in a cured product matrix is optimally sandwiched between a pair of substrates with electrodes. It is.

In this light control body, a blurred portion is obtained in a state where a specific applied voltage (including a case where no voltage is applied) is applied, and in a state where another specific applied voltage (including a case where no voltage is applied) is applied. What is necessary is just to become a completely transmissive state. Specifically, a partially blurred portion is obtained when no voltage is applied, and a completely transparent state is obtained when a sufficiently high voltage is applied.

Since such a dimmer is constituted by an element in which an electro-optical medium that changes a transmission-scattering state is sandwiched between substrates with electrodes, the substrate itself is made of glass, plastic, or the like used for vehicles. In the case of a transparent body, the element itself can be used as a vehicle light control body.

If the substrate itself cannot be used as a vehicle dimmer due to its strength, etc., a transparent body such as glass or plastic that can be used as a transparent body for vehicles is laminated or sandwiched between them. It may be used as a light control body. Specifically, a thin plastic substrate is used as the substrate of the element, and if it is sandwiched between two glass plates, it becomes a laminated glass.

FIG. 1 is a front view showing a vehicle light control body 1 in which the degree of scattering is higher on the upper side, where (A) shows a blurred state and (B) shows a completely transmissive state. 2 indicates a blurred portion, which is shown in (A),
(B) is gone.

FIG. 2 shows that the element 13 having the dimming function is
FIG. 4 is a cross-sectional view showing a state where the adhesive layer 15 is attached.

FIG. 3 shows that the element 23 having the dimming function is composed of two transparent bodies.
FIG. 6 is a cross-sectional view showing a state where the adhesive layer 25 is attached between 24A and 24B to form a laminated glass. In this example, the element 23 having the dimming function is slightly smaller than the transparent bodies 24A and 24B, but the element having the dimming function is not arranged in the transmission portion where the transmittance may not change. You may do so.

The vehicle dimmer according to the present invention has various uses such as a windshield for an automobile, a train, etc., a side glass, a side glass bent into a roof of a sightseeing bus, a sightseeing train, a sightseeing ship, etc., and a windshield for an aircraft. Both are mainly used by drivers and customers to take in or weaken sunlight or the like depending on their preference.

In the present invention, it is preferable to use a film-like liquid crystal layer in which a liquid crystal substance is dispersed and held in a cured product matrix, and this will be described more specifically.

In such a film-like liquid crystal layer, specifically, when the refractive index of the cured product matrix is the ordinary light refractive index (n _o ), the extraordinary light refractive index (n _e ) of the liquid crystal substance, or the liquid crystal substance is randomly oriented. To any of the refractive indices (n _x ). When the refractive index of the cured product matrix and one of the above-mentioned refractive indices of the liquid crystal substance match according to the voltage application state, the film-like liquid crystal layer is in a transmission state, and when not, the film-like liquid crystal layer is in a scattering state. .

For this reason, in the present invention, a portion in which the transmittance at the time of scattering is partially reduced is formed in advance, and a blurred portion is formed, or a voltage in which the threshold voltage of the liquid crystal is partially changed is applied. The transmission state may be different.

LCD An example, the refractive index of the resulting cured product, cured product matrix chosen to coincide with any of the ordinary refractive index of the liquid crystal material (n _o) or the extraordinary refractive index (n _e) to be used An example in which a film-like liquid crystal layer in which a substance is dispersed and used is described.

In such a film-like liquid crystal layer, when no voltage is applied, the refractive index (n _x ) of the liquid crystal substance that is not aligned (randomly aligned) with the cured product matrix does not match, so that the scattering state (white turbidity) occurs. a state), the state of applying a sufficiently high voltage than the threshold voltage, the refractive index of the liquid crystal material arranged between the cured matrix refractive index (n _o or
n _e ), so that the transmission state is established.

For this reason, in the case of automobile windshields, etc.,
The portion other than the portion to be blurred, that is, the portion which is always in the transmission state, is made such that the film-like liquid crystal layer is always in the transmission state irrespective of the voltage application state, or the voltage is always applied in use to transmit the liquid crystal layer. State. In order to keep the transmission state irrespective of the voltage application state, the film-like liquid crystal layer may be cured while applying a voltage when the film-like liquid crystal layer is cured.

For the portion to be blurred, a portion in which the transmittance at the time of scattering is partially reduced in advance may be formed, or the threshold voltage of the liquid crystal may be partially changed.

Specifically, in the former case, during the curing step of forming the film-like liquid crystal layer, by curing while applying a voltage only to a specific portion, the transmittance at the time of partial scattering is reduced in advance. Can be formed. The transmittance at the time of scattering can be controlled by the applied voltage, the voltage application time during the curing period, and the like, and these may be determined experimentally.

In the present invention, in particular, a photocurable compound can be easily obtained by using a photocurable compound as a raw material of a cured product while applying a voltage during curing by light exposure.

Specifically, using a mask whose transmittance is partially changed gradually, curing is performed for a certain time while applying light while applying a voltage, and then removing the mask and applying no voltage. The curing may be completed by irradiating light again. of course,
The reverse is also possible.

In the latter case, during the curing step of forming the film-like liquid crystal layer, the curing condition is changed only for a specific portion, so that the threshold voltage or the saturation voltage of the film-like liquid crystal layer is partially increased. Can form different parts. This is specifically temperature, light, etc., and may be determined experimentally.

In addition, even if the substrate gap is partially changed, a portion where the threshold voltage or the saturation voltage of the film-like liquid crystal layer is different can be partially formed, but the control tends to be difficult.
As described above, it is preferable to change the curing conditions while maintaining the same substrate gap.

In particular, it can be easily obtained by using a photocurable compound as a raw material of a cured product and curing by changing the temperature during curing by light exposure.

Specifically, light exposure may be performed simultaneously by partially changing the temperature, or curing may be performed by gradually raising or lowering the temperature while irradiating light using a mask whose transmittance is gradually changing. It should be done.

Of course, the like if the transmission state is like to change stepwise, keeping the temperatures T _1, which is arranged to mask, irradiated with light to cure the unmasked portions, and then move or change the mask Te light irradiation again at other temperatures T _2, may cure the uncured portion by repeating this.

These applied voltages and curing conditions may be determined experimentally depending on the purpose, materials used, and the like.

Further, in the device of the present invention, the refractive index of the cured product cured by light exposure can be made to match the refractive index ( _nx ) when the liquid crystal substance used is randomly oriented. Here, the term "randomly oriented" means that not all liquid crystal molecules are arranged parallel or perpendicular to the substrate surface, but are oriented in various directions due to the influence of the mesh or capsule constituting the cured product matrix. Indicates that.

In this case, when no voltage is applied, the refractive index (n _x ) of the liquid crystal substance that is not aligned (randomly aligned) matches the refractive index of the cured product matrix, so that the liquid crystal material shows a transmission state. Conversely, when a voltage is applied,
Since the refractive index of the liquid crystal material arranged between (n _o or n _e) and the refractive index of the cured product matrix do not match, and thus showing a scattering state (opaque state).

As a result, a transparent element can be obtained in the state where no voltage is applied, but the cured product matrix obtained by photocuring exists in a mesh or capsule shape, and the liquid crystal is randomly aligned under the influence of the cured product matrix. There is a problem that it is difficult to achieve a uniform state because the situation is the same as that described above.

This is because when the liquid crystal is vertically or horizontally oriented as in the former, it is easy to uniformly align the liquid crystal. Is slightly different, causing a difference in the refractive index,
This is because it is easy to see as unevenness.

In the present invention the refractive index of the cured product matrix, but to match the refractive index of the liquid crystal material to be used (n _o, n _e, one of n _x). It is preferable that the coincidence be completely coincident, but it is sufficient that the coincidence is made so as not to adversely affect the transmission state. Specifically, it is preferable that the difference in the refractive index is set to about 0.15 or less. This is because the cured product matrix swells due to the liquid crystal substance and approaches the refractive index of the liquid crystal substance more than the refractive index originally possessed by the cured product matrix. become.

In the present invention, it is preferable to form a cured product matrix by photocuring using a photocurable compound.

As a result, as described above, it is possible to form a portion in which light transmittance gradually varies in a scattered state in a desired portion or a film-like liquid crystal layer in which a threshold voltage or a saturation voltage gradually varies in a desired portion. Can be easily done. That is, a mask that blocks light is disposed on the surface of the substrate, and a mask whose transmittance is gradually changed, a voltage applied during curing, or a simple operation such as a temperature change during curing can be easily blurred. Can be formed.

The photocurable compound may be any compound that can be cured by infrared rays, visible rays, ultraviolet rays, and electron beams. The action of the light may be anything that promotes curing, and may be any of photons, electrons, and heat.

Therefore, in order to polymerize the photocurable compound, any of vinyl polymerization, addition polymerization, condensation polymerization, cationic polymerization, anionic polymerization, living polymerization and the like may be used, but moisture, a liquid crystal substance such as a corrosive substance is deteriorated. Condensation polymerizations that generate potentially hazardous substances are generally not preferred.

Further, the polymerization system may be uniform or heterogeneous. For example, a mixture of a photocurable compound and liquid crystal may be used, or a photocurable compound and liquid crystal mixed with polyvinyl alcohol or the like and microencapsulated may be used.

Specific examples of the photocurable compound include monoacrylate, diacrylate, N-substituted acrylamide,
N-vinylpyrrolidone, styrene and derivatives thereof,
Polyol acrylate, polyester acrylate,
Examples include compounds having monofunctional and polyfunctional vinyl groups represented by urethane acrylate, epoxy acrylate, silicone acrylate, fluoroalkyl acrylate, acrylate having polybutadiene skeleton, isocyanuric acid skeleton or hydantoin skeleton, unsaturated cycloacetal, and the like. .

In the present invention, it is preferable to use these various photocurable vinyl compounds. Among them, it is preferable to use an acryloyl compound because the liquid crystal and the cured product after light exposure have excellent phase separation state and uniformity, and the curing speed by light exposure is high and the cured product is stable. . The acryloyl group of the acryloyl compound referred to herein is α
Position, β position hydrogen is phenyl group, alkyl group, halogen,
It may be substituted with cyano or the like.

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

Specifically, the photocurable vinyl compound preferably contains 15 to 70% by weight of an acrylic oligomer containing two or more vinyl groups, has little shrinkage due to curing after photocuring, and has a small crack in the liquid crystal optical element. Less likely to occur,
Good moldability. If these minute cracks increase,
The light transmittance in the light transmitting state tends to decrease, and the performance of the element decreases. If the viscosity of this acrylic oligomer is too high or too low, it will adversely affect the moldability.
It is preferable to be about 150 to 500,000 cps.

The liquid crystal substance used in the present invention includes a nematic liquid crystal substance, a smectic liquid crystal substance, and the like, and may be used alone or in a composition.However, in order to satisfy various required performances such as an operating temperature range and an operating voltage. It may be advantageous to use the composition. In particular, the use of a nematic liquid crystal is preferred.

Further, the liquid crystal substance used is preferably uniformly dissolved in the curable compound, and a substance that does not dissolve or is difficult to dissolve in the cured product matrix after curing is required. It is desirable that the solubility of the liquid crystal material is as close as possible.

In particular, by using a liquid crystal substance and a photocurable compound and undergoing a photocuring process, the liquid crystal substance and the cured product are fixed by phase separation, and a structure in which the liquid crystal substance is scattered in a cured product matrix is formed. The distribution of the cured product matrix becomes uniform, and an element excellent in appearance quality and productivity can be easily manufactured.

In producing the device of the present invention, the curable compound and the liquid crystal substance may be a mixture of about 5:95 to 45:55, and may be used as a liquid or a viscous substance.

Further, a mixture of a curable compound and a liquid crystal substance for forming a film-like liquid crystal layer may be used alone or in combination with the curable compound and the liquid crystal substance, and a modifying agent necessary for element preparation, prepared. It may contain an element modifier or the like. Specifically, a crosslinking agent, a surfactant, a diluent, a thickener, a defoaming agent, an adhesion-imparting agent, a stabilizer, an absorbent, a dye,
It may contain a polymerization accelerator, a chain transfer agent, a polymerization inhibitor, a pigment, a dye, and the like.

When manufacturing the device of the present invention, the mixture of the curable compound and the liquid crystal substance to be prepared may be a liquid or a viscous material as long as they are uniformly mixed. You can choose For example, In ₂ O ₃ −SnO ₂ , SnO ₂
In general, it is more convenient to inject a liquid in a cell in which the glass substrate with a transparent electrode and the like are arranged so as to face each other and seal the periphery of the cell. When the opposing substrates are to be overlaid, the viscous state is generally more convenient.

The gap between the substrates can be operated at 5 to 100 μm, but it is appropriate to set it to 7 to 40 μm in consideration of the applied voltage and the contrast at ON / OFF.

Thus, the mixture held on the substrate is cured. In this case, using a photocurable compound, by light exposure,
It is preferable that the liquid crystal material and the cured product matrix are fixed in a phase-separated state. In the case where the refractive index of the cured product matches the n _o or n _e of the liquid crystal material before the light exposure, if the contents held by the substrate if uniformly dissolved, it is colorless and transparent, light exposure After that, the liquid crystal material becomes cloudy due to the refractive index scattering by the unaligned liquid crystal material and the cured product matrix. Of course, if there is a portion that has been cured while applying a voltage, its turbidity is low or it is in a transmission state.

In this device, the liquid crystal material starts to be aligned by applying a voltage higher than the threshold value, the refractive index approaches the cured material, the transmittance increases, and the applied voltage above the saturation voltage causes the cured material to be refracted. The rates match and a high transmission state results.
In this case, if there is a portion where the threshold voltage or the saturation voltage is partially different, a portion where the transmission state is partially different appears before the transmission state is reached.

In addition, when the refractive index of the cured product matrix is matched with the refractive index ( _nx ) of the liquid crystal material, before the light exposure, if the content held on the substrate is uniformly dissolved, it is colorless and transparent. In addition, after light exposure, the liquid crystal material that is not aligned and the cured product have the same refractive index, so that they are in a transmission state.

In the case of this element, when the element is cured while applying a voltage, the element does not completely enter the transmissive state, so that the threshold voltage or the saturation voltage is partially different. In this element,
When a voltage is applied, the liquid crystal substances are arranged, and the cured product and the refractive index are shifted and scattered, so that the liquid crystal material becomes cloudy. In this case, if there is a portion where the threshold voltage or the saturation voltage is partially different, a portion where the transmission state is partially different before the cloudy state appears.

In addition, dichroic dyes, simple dyes and pigments are added to the liquid crystal, colored ones are used as curable compounds, colored substrates are used as substrates, and color filters are laminated. You can also add a specific color.

By using a liquid crystal substance as a solvent and curing the photocurable compound by light exposure, there is no need to evaporate a mere solvent or water that is unnecessary at the time of curing, so that it can be cured in a closed system, high reliability, and Since the photocurable compound also has the effect of bonding the two substrates, a sealant can be eliminated.

For this reason, the productivity of supplying a solution of a photocurable compound and a liquid crystal substance on one electrode-attached substrate, further superimposing the other electrode-attached substrate thereon, and then irradiating light to cure the material. Good manufacturing methods can be adopted.

In particular, by using a plastic substrate as the substrate with electrodes, a thin and long liquid crystal optical element using a continuous plastic film can be easily manufactured, laminated with a transparent body such as glass or plastic, or sandwiched between transparent bodies. Easy to do.

By using such a film-like liquid crystal layer,
Even with a large area, the risk of short-circuiting between the upper and lower transparent electrodes is low, and there is no need to strictly control the orientation and the substrate gap as in a normal twisted nematic type display element, significantly lowering the transmittance and darkening This eliminates the need for using a polarizing plate having a problem in durability and makes it possible to manufacture a vehicle light modulator having a large area with extremely high productivity.

In order to reduce unevenness in the light transmission state, it is better that the substrate gap is constant to some extent. Therefore, it is better to dispose a spacer for controlling the gap such as glass particles, plastic particles, and ceramic particles in the substrate gap. preferable.

The element holding the film-shaped liquid crystal layer may be used as it is as a vehicle light controller when the substrate itself is made of thick glass or plastic. In the case where the substrate is made of thin plastic or thin glass, a transparent body such as plastic or glass, which is an original transparent body for vehicles, is laminated or sandwiched between them.

In particular, a plastic substrate is used as a substrate with electrodes for the element sandwiching the film-like liquid crystal layer, and an electrode lead-out line is attached to the element, and this is sandwiched between two glass plates slightly larger than this element, such as polyvinyl butyral. It is preferable that the element and the glass plate are integrated and laminated to form a laminated glass by holding the adhesive material layer through the adhesive material layer and curing the adhesive material layer by heating or light irradiation. Particularly, by using polyvinyl butyral as the adhesive material, a structure very similar to ordinary laminated glass can be obtained. Thereby, it can be used for a windshield of an automobile and the like in the same manner as ordinary laminated glass. Of course, there is also a method of sticking it to one transparent body and using it.

In particular, using a plastic film substrate for the substrate,
Since it can be cut at an arbitrary position later, the productivity is extremely high, which is suitable for a vehicle light control body requiring a large size.

When driving this dimmer, a driving means is added,
In the case where there is a difference between the threshold voltage and the saturation voltage, a driving means capable of applying two or more types of voltages may be added.
As the driving means, a driving means capable of switching and applying an alternating voltage of about several tens of volts as described later is used.

When applying a voltage for driving the liquid crystal optical element of the present invention, an AC voltage that changes the alignment of the liquid crystal may be applied. Specifically, an AC voltage of 5 to 100 V and about 10 to 1000 Hz may be applied so that the light transmission state of the element changes.

In addition, when no voltage is applied, it is usually sufficient to open or short-circuit the electrodes, but a voltage lower than the threshold may be applied.

Further, the transmittance may be changed by applying a voltage of three or more different levels or by changing the voltage gradually and continuously.

[Examples] Hereinafter, the present invention will be specifically described with reference to examples.

Example 1 7 parts of 2-ethylhexyl acrylate, 15 parts of 2-hydroxyethyl acrylate, 24 parts of an acrylic oligomer (M-1200, manufactured by Toa Gosei Chemical Co., Ltd., viscosity 30,000 cps / 50 ° C.), a photocuring initiator (“Darocur” manufactured by Merck) 1116 ") 0.9
And 64 parts of a liquid crystal (“E-8” manufactured by BDH) were uniformly dissolved. A 14 μm spacer was added to this and dispersed well. The mixture was cast on a 50 cm wide polyester film substrate with ITO, on which a 50 cm wide polyester film substrate with ITO was overlaid.

In addition, the width 30 cm is transparent from above, and the remaining width 20 cm
cm is placed on a polyester film substrate with ITO sandwiching the liquid crystal mixture with a mask that gradually increases the degree of light blocking toward the edges, and exposed to ultraviolet light for 30 seconds while applying a voltage of 50 Hz and 30 V between the ITO electrodes. did. Next, the mask was removed, and ultraviolet light was again exposed for 30 seconds to produce a device having a film-like liquid crystal layer.

In the device manufactured in this manner, the portion having a width of 30 cm was transparent, and the remaining portion having a width of 20 cm gradually increased in opacity toward the end (the other side was difficult to see).

When a voltage of 50 Hz and 50 V was applied to this device, the entire device became a transmission state.

Since the element was weak in strength as it was, a glass plate was attached to one side and used for a side glass of an automobile.

In addition, a glass plate was arranged on both sides and bonded through a polyvinyl butyral film to form a laminated glass, which was used for a side glass of an automobile.

In each of these, the upper end of the side glass became blurred or transparent depending on the voltage application state.

Example 2 The mixture of Example 1 was cast on a 25 cm wide polyester film substrate with ITO, and a 25 cm wide polyester film substrate with ITO was overlaid thereon.

Furthermore, it is transparent with a width of 15 cm from above, and the remaining width of 10 cm
In cm, a mask having a degree of light shielding gradually increased toward the end was placed on a polyester film substrate with ITO sandwiching the liquid crystal mixture, and exposed to ultraviolet light for 30 seconds. Next, the mask was removed, and ultraviolet rays were exposed for 30 seconds while applying a voltage of 50 Hz and 30 V between the ITO electrodes, thereby producing a device having a film-like liquid crystal layer.

In the device manufactured in this manner, the portion having a width of 15 cm was cloudy, and the remaining portion having a width of 10 cm was gradually reduced in cloudiness toward the end (the other side was easy to see).

When a voltage of 50 Hz and 50 V was applied to this device, the entire device became a transmission state.

This element was attached to the upper end of the tempered glass plate such that the side with higher turbidity was located on the upper end, and used for an automobile windshield.

In addition, glass plates are arranged on both sides, this element is arranged so that the side with high turbidity is on the upper end side, adhered via a polyvinyl butyral film to form a laminated glass, and it is used as a windshield for automobiles used.

In any of these, in the state where no voltage is applied, the portion 15 cm wide from the upper end of the windshield is cloudy, and the remaining 8 cm wide portion gradually decreases in cloudiness toward the end, The lower portion was transparent because no film-like liquid crystal layer was present.

When a voltage was applied thereto, all portions including the portion where the film-like liquid crystal layer was present were in a transmission state.

Example 3 On a polyester film substrate with ITO sandwiching the liquid crystal mixture of Example 1, a mask having a light shielding degree gradually increased toward an end from a portion above a portion 20 cm from the top was placed.
UV light was applied at ℃. Then, the temperature was set to 35 ° C., and after the mask was removed, ultraviolet rays were irradiated.

The device thus obtained was in a state of being scattered entirely without applying a voltage, and became entirely transparent when a voltage of 50 Hz and 100 V was applied.

However, when a voltage was gradually applied to this element, for example, at a voltage of 50 Hz and 20 V, the lower 30 cm width portion was almost transparent, and the remaining 20 cm width portion gradually toward the end. The cloudiness was high (the other side was difficult to see). Further, as the voltage was increased, the white turbid portion gradually narrowed, and became completely transparent at a voltage of 50 Hz and 100 V.

Since this element was also weak in strength as it was, a glass plate was attached to one side and used as a side glass of an automobile.

In addition, a glass plate was arranged on both sides and bonded through a polyvinyl butyral film to form a laminated glass, which was used for a side glass of an automobile.

In each of these, the upper end of the side glass became blurred or transparent depending on the voltage application state.

Example 4 One of the polyvinyl butyral films of Example 2 was colored deep blue over 15 cm above and gradually faded downward 12 cm below and transparent under the so-called blur. Was laminated using a polyvinyl butyral film containing.

In the thus obtained windshield, although the film-like liquid crystal layer was only partially present, the boundary between the existing portion and the non-existent portion was almost inconspicuous. .

[Effects of the Invention] As described above, the dimmer according to the present invention has a portion in which the transmission state is gradually different depending on the voltage application state, that is, a so-called blurred portion. You can change the rate.

In particular, the refractive index of the obtained cured product is any one of the ordinary light refractive index (n _o ), the extraordinary light refractive index (n _e ), and the refractive index (n _x ) when the liquid crystal material is randomly aligned. By using a film-like liquid crystal layer in which the liquid crystal substance is dispersed and held in the cured product matrix selected to match with the above, the production is easy even in a large area, the use of a polarizing plate is not necessary, and it is bright, A high-speed and high-life vehicle light control body can be easily obtained with high productivity.

In particular, when using a photocurable compound as the curable compound and curing by light exposure, by applying a voltage or changing the temperature to cure, the scattering property can be easily changed partially or the threshold value can be changed. The voltage or the saturation voltage can be changed. In addition, since the photocuring is performed, the curing time is short, and the productivity is extremely high.

Further, it can be manufactured by basically the same method as a conventional method of manufacturing a liquid crystal optical element having a transmission-scattering control film-like liquid crystal layer, and only a few steps are added. Hardly lowers.

Further, by providing a transparent body on at least one surface of the substrate, safety is improved, and particularly, by providing a transparent body on both sides to form a mating structure, damage is less likely to occur,
Like ordinary laminated glass, it can be easily applied to automobiles and the like.

In particular, by supplying a liquid crystal substance, a photocurable compound, particularly a photocurable vinyl compound, and, if necessary, a mixture with a photocuring initiator on the substrate, and placing the other substrate on it, A large-area element can be manufactured with extremely high productivity. For this reason, even in the case of glass, a considerably long substrate can be used, and in the case of a plastic substrate, a continuous process using a continuous film becomes possible.

The present invention is also applicable to various applications within a range that does not impair the effects of the present invention.

[Brief description of the drawings]

FIG. 1 is a front view showing a vehicle dimmer according to the present invention, wherein (A) shows a blurred state and (B) shows a completely transmissive state. 2 and 3 are cross-sectional views of a vehicle light control body according to the present invention. Vehicle dimmer: 1 Blur: 2 Device with dimming function: 13, 23 Transparent: 14, 24A, 24B Adhesive layer: 15, 25

Claims (2)

(57) [Claims] 1. A method for producing a vehicle light control body, wherein a transparent body for a vehicle, at least a part of which is changed in transmission state by application of a voltage, has a refractive index of a cured product obtained by:
A cured product matrix selected to match either the ordinary index of refraction (n _o ), the extraordinary index of refraction (n _e ) of the liquid crystal material used, or the index of refraction (n _x ) when the liquid crystal material is randomly oriented. When a mixture of a photocurable compound and a liquid crystal substance forming a liquid crystal material is sandwiched between a pair of substrates with electrodes, and when the whole is photocured, a part thereof is cured while applying a voltage, and the transmission state gradually changes. A method for manufacturing a light control body for a vehicle, characterized by forming a portion where the light is controlled. 2. A method for manufacturing a vehicle light control body, wherein the transparent state of the vehicle is at least partially changed by application of a voltage.
A cured matrix selected to match either the ordinary refractive index (n _o ), extraordinary refractive index (n _e ), or the refractive index (n _x ) of the liquid crystal material when it is randomly oriented. When a mixture of a photocurable compound and a liquid crystal substance forming a liquid crystal material is sandwiched between a pair of substrates with electrodes, and when the whole is photocured, a photocurable material which is a raw material of a cured product under partially different temperature conditions is used. A method for producing a vehicle light control body, comprising: curing a compound to form a portion having a gradually different transmission state.