JP2660565B2 - Patterned light control material and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a patterned tone used for various dimming applications such as displays, signboards, blinds, daylighting materials, partitions, etc. by causing a difference in optical properties. Light materials.

[Conventional technology]

As a light modulating material using liquid crystal, a nematic liquid crystal is emulsified and dispersed in an aqueous solution of polyvinyl alcohol and encapsulated, applied on a transparent electrode substrate, dried to form a liquid crystal layer, and then a counter electrode is formed thereon. There is known a light control material in which another transparent electrode substrate is bonded (see Japanese Patent Application Laid-Open No. 58-50 / 1983).
1631).

In addition, a liquid crystal layer in which liquid crystal is dispersed without being encapsulated in an epoxy resin matrix of bisphenol A,
A light control material formed between opposing transparent electrode substrates is also known (Japanese Patent Publication No. 61-502128).

These light modulating materials, when a voltage is applied between the transparent electrodes,
Since the liquid crystal layer changes from a cloudy light scattering state to a transparent light transmitting state, the above-described various light control applications are expected.

[Problems to be solved by the invention]

However, the transparent electrode substrate of the light modulating material is formed by depositing a metal oxide such as ITO on one entire surface of a transparent substrate such as a transparent plastic film, or by applying a transparent conductive paint to the transparent substrate. Since a transparent electrode was formed on one entire surface, when a voltage was applied between the transparent electrodes, the entire liquid crystal layer changed from a cloudy state to a transparent state, and a pattern or the like could not be developed or disappeared.

Therefore, the present inventors have already proposed a light control material in which at least one transparent electrode is patterned into a desired pattern or pattern by means such as etching (Japanese Patent Application No. 63-164530).
In such a light control material, when no voltage is applied between the transparent electrodes, the liquid crystal layer is entirely turbid as in the case of the conventional light control material, but when a voltage is applied, one of the patterned liquid crystal layers is formed. Since it becomes transparent according to the pattern shape of the transparent electrode, and the other portions remain in a cloudy state, a transparent watermark pattern is developed, so that it is possible to perform variable light control.

However, when the transparent electrode is patterned by etching as in the above-mentioned light control material, first, a photoresist film is formed on the surface of the transparent electrode, and a mask plate on which the pattern is formed is overlapped thereon, and exposed. Since the photoresist film must be opened in the pattern shape and then immersed in an etchant to remove the photoresist film remaining on the surface at the end, there is a problem that it is troublesome and costly.

Further, the light control material in which the transparent electrodes are patterned cannot exhibit a transparent watermark pattern when no voltage is applied between the transparent electrodes, and makes the entire liquid crystal layer transparent even when a voltage is applied. Therefore, it is not suitable for dimming applications where light transmission is prioritized over light scattering.

The present invention has been made in view of the above circumstances, and aims to develop a transparent watermark or opaque pattern when no voltage is applied, and the entire liquid crystal layer becomes transparent when a voltage is applied. It is an object of the present invention to provide a light modulating material with a pattern, in which the pattern disappears and a pattern can be formed on the liquid crystal layer by means much simpler than etching or the like, and a method for manufacturing the same.

[Means for solving the problem]

In order to achieve the above object, the patterned light modulating material of the present invention is a light modulating material comprising at least a liquid crystal layer in which liquid crystal is dispersed in a solidified resin matrix, and transparent electrodes laminated on both surfaces thereof. The liquid crystal layer is characterized by exhibiting a transparent or cloudy pattern pattern in a state where no voltage is applied between the transparent electrodes, and the production method of the present invention A light modulating material including at least a liquid crystal layer in which liquid crystal is dispersed in a resin matrix and transparent electrodes laminated on both surfaces of the light modulating material is prepared, and a mask material having a pattern formed thereon is overlaid on one surface of the light modulating material. In addition, a voltage is applied between the transparent electrodes of the light control material to irradiate the light control material through the mask material while keeping the liquid crystal layer transparent.

The term "pattern pattern" as used in the present specification is a term of a broad concept encompassing not only patterns but also various display patterns such as designs, characters, symbols, etc., and "transparency" refers to a state in which transparency is extremely high. The term is a concept term that includes processing to a semi-transparent state to the extent that it can be distinguished from cloudy spots, in addition to the processing described above.

(Operation)

When a liquid crystal layer in which liquid crystal is dispersed in a solidified resin matrix and a transparent electrode laminated on both surfaces of the liquid crystal layer is used, when no AC voltage is applied between the transparent electrodes, the liquid crystal layer scatters transmitted light. However, when an AC voltage is applied to apply an electric field to the liquid crystal layer, the liquid crystal molecules are oriented in the direction of the electric field and become transparent.

The present inventors partially irradiate a light control material (liquid crystal layer) with a light beam while keeping the liquid crystal layer transparent by applying a voltage as described above, and the irradiated portion is fixed in a transparent state, and the voltage is reduced. We have found a new fact that it does not return to a cloudy state even when no voltage is applied. The reason why the light-irradiated part is made transparent in this way is not clear, but there is probably a substance that reacts by light irradiation in the matrix resin, and the substance acts on the liquid crystal molecules under light irradiation, and the liquid crystal molecules are aligned. It is presumed that it is kept as it is.

The present invention is directed to forming a pattern pattern on a liquid crystal layer by utilizing the above-described light-irradiation effect of the liquid crystal layer to make the liquid crystal layer transparent. Liquid crystal molecules are oriented in the direction of the electric field and change from a cloudy state to a transparent state, and the entire liquid crystal layer becomes transparent and the pattern disappears. Then, when the voltage application is stopped, the light-irradiated portion maintains the transparent state as it is, whereas the transmitted light is scattered and returns to the cloudy state in the light-non-irradiated portion, so that the transparent or cloudy pattern according to the pattern pattern appears. .

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a plan view showing one embodiment of a patterned light control material of the present invention, and FIG. 2 is an enlarged cross-sectional view taken along the line ABCD of FIG.

The patterned light modulating material of this embodiment includes two transparent resin films 3a, 3b (hereinafter, referred to as transparent electrode films) each having transparent electrodes 2a, 2b formed on one side on both upper and lower surfaces of the liquid crystal layer 1.
Thickness 100 to 5 laminated so that the transparent electrode is on the liquid crystal layer side
A sheet-like light control material having a five-layer structure of about 00 μm, in which transparent pattern patterns 4a, 4b, and 4c are formed in the liquid crystal layer 1 and one side edge of one (upper) transparent electrode 2a. Collector electrodes 5a and 5b are provided on the other (lower) edge of the transparent electrode 2b (left edge) and the other (lower) transparent electrode 2b. One end of each of the collecting electrode portions 5a, 5b is provided with a lead wire connecting terminal strip 6a, 6b protruding to the outside, and the insulating tape 7 covers the periphery of the dimming material.

The liquid crystal layer 1 is obtained by dispersing a liquid crystal in a solidified resin matrix. Specifically, a liquid crystal layer in which a nematic liquid crystal is dispersed in a liquid state in a cured epoxy resin matrix by a phase separation method is preferable. It is. This is because, in such a liquid crystal layer, the liquid crystal dispersed in a droplet state has a substantially uniform particle size of about 1 μm, and the liquid crystal molecules have good orientation, so that high transparency can be obtained. Among them, the cured epoxy resin matrix contains an epoxy resin mainly composed of an aliphatic resin such as a glycidyl ester-based epoxy resin, a glycidyl ether-based epoxy resin, and a glycidylamine-based epoxy resin. A liquid crystal layer adjusted so that the difference from the refractive index is within 0.02 is particularly preferable because it has advantages such as good contrast between the light transmitting state and the light scattering state and the difficulty of yellowing over time.

The blending amount of the liquid crystal is not particularly limited as long as the light scattering rate is within an allowable range. However, considering the economics of using an expensive liquid crystal, the weight ratio of the liquid crystal to the resin matrix 1 is 2%. It is good to be in the range of -0.01, preferably in the range of 1-0.1. In addition, in order to make the thickness of the liquid crystal layer 1 uniform, transparent synthetic resin microbeads or glass having a light refractive index equal to or close to the light refractive index of the resin matrix may be contained as necessary.

As will be described later, the transparent pattern patterns 4a, 4b, 4c of the liquid crystal layer 1 are formed by superposing a mask material obtained by cutting out the pattern patterns 4a, 4, 4c on one surface of the light control material and forming a transparent material between the transparent electrodes 2a, 2b. It is formed by irradiating a light beam through a mask material in a state where a voltage is applied to make the liquid crystal layer 1 transparent to partially make the liquid crystal layer 1 transparent. The transparent state is maintained, and the liquid crystal layer 1 does not return to the cloudy state again as in the non-light-irradiated portion (the portion other than the transparent pattern pattern). Various rays such as the sun, a fluorescent lamp, and an electric lamp (lamp) can be used as the above-mentioned rays, but ultraviolet rays are most preferable in terms of illuminance and time. In addition, the above-mentioned mask material may be any material that can block light rays, and for example, a metal plate or a light-shielding plastic sheet or film is used.

The transparent electrode films 3a and 3b laminated on the upper and lower surfaces of the liquid crystal layer 1 are made of, for example, polyethylene terephthalate,
On one side of a transparent resin film such as polyethersulfone or polycarbonate, a metal oxide such as ITO or tin oxide is deposited or sputtered or a transparent conductive paint is applied to form the transparent electrodes 2a and 2b on one side. It is formed as a whole.

In addition, collector electrodes 5a, 5b provided at the edges of the transparent electrodes 2a, 2b.
5b is for making the voltage between the transparent electrodes 2a and 2b substantially uniform, and the collector electrode portion 5a on the right edge cuts off the right edge of the liquid crystal layer 1 and the right edge of the lower transparent electrode film 3b. By exposing the right edge of the upper transparent electrode 2a in a strip shape, and applying a conductive paste such as a copper paste, a silver paste, or a carbon paste to the exposed portion, it is formed so as not to be short-circuited with the lower transparent electrode 2b. The collector electrode portion 5b on the left edge is cut off the left edge of the liquid crystal layer 1 and the left edge of the upper transparent electrode film 3a to expose the lower transparent electrode 2b in a strip shape. By applying the conductive paste described above, the conductive paste is formed so as not to be short-circuited with the upper transparent electrode 2a. The collector electrodes 5a and 5b may be formed by attaching a metal foil tape such as a copper foil tape to the exposed portions of the transparent electrodes 2a and 2b.

Terminal pieces 6a, 6b attached to one end of the collector electrodes 5a, 5b are:
For example, metal foil tape such as copper foil tape, phosphor bronze, copper,
It is made of a thin metal piece such as aluminum, and is adhered by a conductive adhesive or the like, and a lead wire is connected to a protruding portion of the terminal piece 6a, 6b.

Further, the insulating tape 7 covering the periphery of the light control material prevents moisture penetration, electric leakage, electric shock, delamination of the light control material periphery, etc., and is made of, for example, transparent polypropylene resin or polyvinyl chloride resin. An adhesive insulating tape or the like is used. Instead of the insulating tape 7, a transparent insulating adhesive such as an epoxy resin or a silicone resin may be applied to the periphery of the light control material to cover it.

The patterned light modulating material having the above-described configuration is used for the transparent electrodes 2a and 2a.
In the state where no AC voltage is applied between b and b, the pattern patterns 4a, 4b and 4b of the liquid crystal layer 1 are transparent and portions other than the pattern pattern (hereinafter referred to as non-pattern portions) are clouded. By contrast, the transparent watermark pattern appears as the pattern. In this state, when an AC voltage is applied between the transparent electrodes 2a and 2b to apply an electric field to the liquid crystal layer 1, the liquid crystal molecules in the non-pattern portion of the liquid crystal layer 1 are oriented in the direction of the electric field, and the ordinary photorefractive index of the liquid crystal and the resin The light refractive index of the matrix is changed to the transparent state from the white turbid state by the same or similar, and the entire liquid crystal layer 1 becomes transparent and the pattern disappears. Then, when the voltage is not applied again, the pattern 4
While a, 4b, and 4c maintain transparency, the non-patterned part is scattered by the difference between the extraordinary refractive index of the liquid crystal and the refractive index of the resin matrix, and returns to a cloudy state. The watermark pattern appears again.

In the above embodiment, the pattern patterns 4a, 4b, and 4c are transparent, and a transparent pattern is developed. However, the pattern can be a cloudy pattern. That is, the pattern patterns 4a, 4b, 4c
The mask material is superimposed on one side of the light control material, and the transparent electrodes 2a, 2
When light is irradiated through the mask material in a state where the liquid crystal layer 1 is made transparent by applying a voltage between the pattern patterns 4a, 4b, and 4c.
The other parts become transparent, and the pattern patterns 4a, 4b, 4c remain cloudy. Therefore, when no voltage is applied, the pattern patterns 4a, 4b, 4c become cloudy pattern patterns, and when a voltage is applied, the entire liquid crystal layer 1 becomes transparent and the pattern disappears.

As described above, the patterned light control material of the present invention can perform a variable light control by expressing or extinguishing a transparent pattern or a cloudy pattern, and when light is applied, light passes through the entire surface, Even when no voltage is applied, light passes through the transparent pattern patterns 4a, 4b, 4c or the non-pattern portions, and thus is suitable for dimming applications in which light transmission is prioritized.

Next, an embodiment of the manufacturing method of the present invention will be described with reference to FIG.

According to this embodiment, first, a sheet-like dimmer having a five-layer structure shown in FIG. 3A, that is, transparent electrode films 3a and 3b are provided on the upper and lower surfaces of the liquid crystal layer 1 and the transparent electrodes 2a and 2b are A sheet-like light modulating material having a structure laminated on the layer side is manufactured. The production of such a sheet-like light control material is performed by using the upper transparent electrode film.
Between 3a and the lower transparent electrode film 3b, an intermediate layer of a resin liquid is formed by sandwiching a resin for forming a liquid crystal layer in which liquid crystal is dissolved or dispersed, and the intermediate layer is heated and cured. This is performed by solidifying the liquid crystal layer 1.

As the resin liquid for forming the liquid crystal layer, a nematic liquid crystal is dissolved in an uncured epoxy resin at the mixing ratio described above,
A mixture obtained by mixing an appropriate amount of a curing agent, a catalyst and the microbeads described above is suitably used. When an intermediate layer is formed from such a resin solution and cured by heating, the liquid crystal gradually becomes insoluble and undergoes phase separation as the cross-linking and curing of the epoxy resin progresses. When the curing is completed, the liquid crystal is 1 μm as described above. Liquid crystal phase 1 having high transparency when a voltage is applied can be formed because the liquid crystal particles are uniformly dispersed as substantially spherical droplets having a substantially uniform particle size. Among such epoxy resin liquids, the epoxy resin is mainly composed of the above-mentioned aliphatic epoxy resin, and the difference between the light refractive index (light refractive index after curing) and the ordinary light refractive index of the liquid crystal is 0.02. The resin liquid adjusted to be within the range is particularly preferably used because the liquid crystal layer 1 having a good contrast between the light transmitting state and the light scattering state and hardly yellowing over time can be formed as described above. .

As shown in FIG. 3 (b), one side edge (right side edge) of one (lower side) transparent electrode film 3b is cut off in the formed sheet-like light control material in the next collector electrode part forming step. Then, as shown in FIG. 3 (c), the conductive paste described above is applied to the exposed electrode portion to form a strip-shaped collector electrode portion 5a, and the lead connecting terminal strip 6a is electrically connected to the collector electrode portion 5a. Glue with an adhesive or the like. Then, in the same manner, as shown in FIG.
The other side edge (left side edge) of the transparent electrode film 3a is cut off, the collector electrode portion 5b is formed on the exposed portion of the transparent electrode 2b, and the terminal piece 6b is bonded.

When the formation of the collecting electrode portions 5a and 5b and the attachment of the terminal pieces 6a and 6b are completed, lead wires are connected to both terminal pieces 6a and 6b as shown in FIG. An AC voltage is applied between 2b to change the liquid crystal layer 1 from a cloudy state to a transparent state. In this state, a mask material 10 from which a pattern pattern 9 is cut out is superimposed on one surface of a light control material, and an ultraviolet irradiation device (light beam) is applied. UV light is irradiated from the irradiation device 11 through the mask material 10. As described above, when the ultraviolet rays are irradiated while the voltage is applied to the transparent electrodes 2a and 2b, the ultraviolet-irradiated portion of the liquid crystal layer 1 is made transparent, and the liquid crystal layer 1 does not return to a cloudy state even when no voltage is applied. As shown in (1), a pattern pattern 4 that is always transparent is formed on the liquid crystal layer 1.

The voltage applied between the transparent electrodes 2a and 2b may be any voltage that is higher than the voltage at which the liquid crystal layer 1 becomes transparent, and the ultraviolet irradiation conditions are such that a sufficient amount of ultraviolet light is applied to make the liquid crystal layer 1 transparent. Irradiation conditions can be used. However, irradiation conditions that are so severe that ultraviolet rays penetrate into the mask portion of the liquid crystal layer 1 should be avoided. An example of suitable conditions for voltage and ultraviolet irradiation is as follows. When the above-mentioned epoxy resin-based liquid crystal layer 1 is irradiated with ultraviolet rays using a 20 W ultraviolet irradiation lamp (FL20S-BL manufactured by Toshiba), the gap between the transparent electrodes is increased. Is about 40 V, the ultraviolet irradiation time is about 10 minutes, and the irradiation distance is about 20 cm. When the transparent pattern 4 is formed on the epoxy resin liquid crystal layer (having a haze of about 90% when no voltage is applied) under such conditions, the haze of the pattern 4 (having a haze when no voltage is applied) is about 20%. %, And a transparent pattern pattern 4 with good transparency is obtained. Q The patterned light modulating material on which the transparent pattern pattern 4 is formed is:
As shown in FIG. 2, the periphery of the light control material is covered with the above-described insulating tape 7 to obtain a product.

In the above embodiment, the transparent pattern was formed.
A cloudy pattern can be formed by using the mask material 10 having the shape of the pattern pattern 9 and performing the same other method. Also, the formation of the collector electrodes 5a, 5b and the terminal strips 6a, 6b
Although the transparent pattern 4 is formed after the mounting, the transparent pattern 4 may be formed first. Further, in the above-described embodiment, the periphery of the light control material is covered with the insulating tape 7 after forming the transparent pattern 4, but may be covered with the insulating tape 7 before forming the transparent pattern 4. . Note that the insulating tape 7 is not always necessary.

As mentioned above, although the Example of this invention was described in full detail, this invention is not limited to an Example, For example, the acrylic resin plate and the polycarbonate resin plate on one side or both sides of the above-mentioned patterned light control material Transparent plastic and glass plates such as polystyrene resin plate and vinyl chloride resin plate
Acrylic, vinyl acetate, silicone, urethane and other adhesives or pressure-sensitive adhesives are used for bonding or sticking by means of room temperature curing, heat curing, ultraviolet irradiation curing, or hot melt seals or butyral sheets. It may be used for bonding or sticking, and various functions may be added by laminating a heat ray cut film, a weather resistance improving film, or the like, or by performing a surface hardness treatment.

〔The invention's effect〕

As is clear from the above description, the patterned light control material of the present invention can perform a variable light control by expressing or eliminating a transparent pattern or a cloudy pattern, and light is not applied when no voltage is applied. Light is transmitted through the entire transparent pattern or non-pattern pattern, and when light is applied, the light passes through the entire surface.This is suitable for dimming applications where light transmission is prioritized. Can be extremely easily performed by partially irradiating the transparent electrode, so that there is an effect that labor and cost are greatly reduced as compared with the case where the transparent electrode is patterned by etching.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view showing one embodiment of a patterned light control material of the present invention, and FIG. 2 is an enlarged cross-sectional view taken along the line ABCD of FIG. 3 (a) to 3 (f) are explanatory diagrams for sequentially explaining one embodiment of the manufacturing method of the present invention. 1 ... liquid crystal layer, 2a, 2b ... transparent electrode, 3a, 3b ... transparent electrode film, 4, 4a, 4b, 4c ... pattern pattern.

Continuation of the front page (72) Inventor Koichi Se 2-30-30 Azuchicho, Higashi-ku, Osaka-shi, Osaka Inside Takiron Co., Ltd. (56) References JP-A 1-2229232 (JP, A) JP-A 2-99920 (JP , A)

Claims (2)

(57) [Claims] 1. A light modulating material comprising at least a liquid crystal layer in which liquid crystal is dispersed in a solidified resin matrix and transparent electrodes laminated on both surfaces thereof, wherein a voltage is not applied between the transparent electrodes. A patterned light modulating material, wherein the liquid crystal layer exhibits a transparent or clouded pattern pattern. 2. A light modulating material including at least a liquid crystal layer in which liquid crystal is dispersed in a solidified resin matrix and transparent electrodes laminated on both surfaces thereof is prepared, and a mask material on which a pattern is formed is prepared. While superimposing on one side of the light material, applying a voltage between the transparent electrodes of the light control material and keeping the liquid crystal layer transparent,
A method for manufacturing a patterned light control material, comprising irradiating a light beam onto the light control material through a mask material.