JPH0212223A - Pattern light control sheet - Google Patents

Abstract

PURPOSE:To easily form intricate patterns, graphic patterns, etc., in a wide range by forming transparent electrodes to both side of a resin layer and patterning at least one of the transparent electrodes. CONSTITUTION:The transparent electrodes 3, 4 are formed both sides of the resin layer 2 formed by dispersing a liquid crystal in a resin matrix. A transparent base material 3a formed with the transparent electrodes 3 patterned and formed with the patterns or graphic patterns and a transparent base material 4a formed with the plane transparent electrode 4 are respectively laminated on both surfaces of the resin layer 2. The impression and non-impression of the voltage of a power source V are switched by a switch S provided between the electrodes 3 and 4. An electric field is, therefore, generated in compliance with the pattern of at least the electrodes 3 of one side when the voltage is impressed between the electrodes 3 and 4. Only the resin layer of the part applied with the electric field of the resin layer 2 is then changed from a light scattering state to a light transmission state. The patterns or graphic patterns which are transparent to the pattern shape are easily formed in a wide range in this way.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for producing a display by creating a difference in optical properties.
Related to patterned light control sheets used for partitions, signboards, etc.

[Prior Art] A light control sheet containing a liquid crystal compound in a resin matrix is prepared by emulsifying and dispersing a nematic liquid crystal in an aqueous polyvinyl alcohol solution, encapsulating it, coating it on a transparent electrode substrate and drying it, and then A light control sheet is known in which another transparent electrode substrate serving as a counter electrode is adhered onto the coating film (Japanese Patent Application Publication No. 58-501631).

Also known is a light control sheet in which a resin layer in which liquid crystal is dispersed without being encapsulated in a bisphenol A type epoxy resin matrix is formed between opposing transparent electrode substrates (Japanese Patent Application Publication No. 61-502128 issue).

[Problems to be Solved by the Invention] However, the transparent electrode substrate used in the above-mentioned light control sheet has been developed by, for example, depositing a metal oxide such as ITO on the entire surface of the transparent substrate, or applying a transparent conductive paint to the entire surface of the transparent substrate. It was common to form a transparent electrode on the entire surface of a transparent substrate by coating the entire surface of the substrate. Therefore, in the above light control sheet, when a voltage is applied between both transparent electrodes, the entire surface of the light control sheet changes from a cloudy light-scattering state to a transparent light-transmitting state. could not be formed.

[Means for Solving the Problems] In order to solve the above problems, the patterned light control sheet of the present invention has the following features:
It is characterized in that transparent IT electrodes are formed on both sides of a resin layer in which liquid crystal is dispersed in a resin matrix, and at least one of the transparent electrodes is patterned.

[Function] In the patterned light control sheet having the above structure, when no voltage is applied between the transparent electrodes on both sides of the resin layer, the liquid crystal molecules in the resin layer are free and irregularly arranged, and the abnormal light of the liquid crystal is Since the refractive index is different from that of the resin matrix, the incident light is scattered due to the refractive index difference. Therefore, the entire resin layer is cloudy like ground glass. However, when a voltage is applied between both transparent electrodes, at least one of the transparent electrodes is patterned, so an electric field is generated in the pattern, and only the liquid crystal molecules in the part of the resin layer where the electric field is applied are exposed to the electric field. The normal light refractive index of the liquid crystal is the same as or close to the refractive index of the resin matrix, and the two become optically the same or close to each other, so the pattern becomes transparent, while other parts remain cloudy. becomes.

[Example] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic perspective view of a patterned light control sheet according to an embodiment of the present invention, and FIG. 2 is a sectional view thereof. The patterned light control sheet 1 shown in the figure includes, for example, a transparent base material 3a on which a transparent electrode (hereinafter referred to as a patterned transparent electrode) 3 formed by patterning a pattern or a design pattern as shown in FIG. 1, and a flat surface. Transparent substrates 4a on which transparent electrodes (hereinafter referred to as planar transparent electrodes) 4 are formed are laminated on both surfaces of the resin layer 2, respectively. Further, in order to obtain weather resistance, a transparent resin plate 8 having an acrylic film 7 or the like laminated thereon is attached to the surfaces of the transparent substrates 3a and 4a on both sides with an adhesive or the like. Then, this patterned light control sheet 1 is turned on by a switch S provided between the transparent electrodes 3 and 4.
It is used to switch between applying and not applying voltage.

The resin layer 2 is formed by separating the liquid crystal dissolved in the epoxy resin matrix 2a into spherical independent liquid crystal droplets (hereinafter referred to as liquid crystal droplets) having a substantially uniform particle size that does not cause large variations by a phase separation method. ) 5. The epoxy resin matrix 2a contains at least one type of aliphatic epoxy resin, such as a glycidyl ester epoxy resin, a glycidyl ether epoxy resin, a glycidyl amine epoxy resin, etc.
For example, aromatic epoxy resins such as bisphenol A type epoxy resins are appropriately mixed and used, and curing can be performed using most of various curing agents such as amine-based, acid anhydride-based, and mercaptan-based curing agents. When the epoxy resin matrix 2a contains at least one type of aliphatic epoxy resin, high transparency can be obtained in a light transmitting state even when the voltage applied between the transparent electrodes is low, and strong clouding occurs when no voltage is applied. It is preferable because it becomes a light-scattering state, has extremely good contrast, has good weather resistance, and is resistant to yellowing, so that excellent transparency can be maintained over a long period of time.

As the resin matrix 2a of the resin layer 2, other acrylic esters, methacrylic esters, ene/thousol-based resins and other radiation-cured resins, polyvinyl alcohol and other water-soluble resins that are cured by irradiation with ultraviolet rays, radiation, electron beams, etc. Almost all resins can be used, such as urethane resin, acrylic resin and other emulsifying resins, polyvinyl chloride and other organic solvent-soluble resins, and glycidyl ester resins. Alternatively, the resin layer 2 may be formed by emulsifying and dispersing the liquid crystal in the resin matrix 2a and encapsulating it.

On the other hand, the liquid crystals that are decomposed into the resin matrix 2a include various types of liquid crystals such as biphenyl, ester, Schinf base, and pyrimidine liquid crystals, which are commonly used in display liquid crystal cells for calculators, watches, automobile meter panels, etc. are used respectively. The optical properties of the mock light control sheet 1 of the present invention are affected by the proportion of this liquid crystal in the epoxy resin matrix 2a, but there is no particular problem as long as the scattering rate of the incident light is within an allowable range. Considering the economic efficiency of using expensive liquid crystal, the weight ratio of liquid crystal to 1 of the epoxy resin matrix 2a is within the range of 2 to 0.01.
Above all, it is preferable to mix so that the refractive index is within the range of 1 to 0.1, and the difference between the refractive index of the resin matrix 2a and the normal light refractive index of the liquid crystal layer 5 is adjusted to be 0.02 or less. This is desirable, because if the refractive index is larger than 0.02, even if a voltage is applied between the transparent electrodes 3.4 to transmit light, the resin layer 2 will become cloudy due to light scattering, making it impossible to obtain high transparency. be.

In order to make the thickness of the resin layer 2 uniform, it is preferable to add a small amount of microbeads as a spacer. ~30μm
Synthetic resin beads of about 100 mL are preferably used.

The transparent electrodes 3 and 4 laminated on both sides of the resin layer 2 are made of, for example, a vapor-deposited film of a metal oxide such as ITO or a coated film of a transparent conductive paint. After forming an electrode on the entire surface of the transparent base material 3a, it is formed by etching a pattern or design pattern as shown in FIG. be done. Note that if the transparent electrodes 3 and 4 are exposed, it will cause problems in terms of safety and other various aspects, so the transparent electrodes 3 and 4 are made of, for example, polyethylene terephthalate, polysulfone, polyethersulfone (PES), polyphenylene sulfide (
PPS), transparent synthetic resin films and plates such as acrylic,
Alternatively, they are coated and protected by being formed in advance on the insides of transparent substrates 3a and 4a such as temporary glass, and laminated on both sides of the resin layer 2 with the transparent molds 8i13.4 facing inside.

In addition, the patterned light control sheet 1 of the present invention has upper and lower transparent resin plates 8 made of a highly transparent polycarbonate plate, acrylic plate, polyvinyl chloride plate, etc. on which a highly weather-resistant acrylic film 7 or the like is laminated. It has a structure in which the surfaces of transparent base materials 3a and 4a are bonded to each other with an adhesive or the like. In this case, a transparent resin plate mixed with an ultraviolet absorber is used as the transparent resin plate 8, and it is cut so that almost no ultraviolet rays are irradiated onto the resin layer 2, thereby suppressing yellowing and deterioration of the resin layer 2 as much as possible. It is desirable to improve gender.

Note that the acrylic film 7 is not necessarily necessary, and a transparent film made of acrylic film or the like may be laminated to the transparent substrates 3a, 4a, or
If a film containing an ultraviolet absorber is used as a and the transparent resin plate 8 is not used, a flexible patterned light control sheet can be obtained.

In the patterned light control sheet 1 of the present invention having the above configuration, if no voltage is applied between the transparent electrodes 3 and 4 on both sides of the resin layer 2,
As shown in FIG. 3, a liquid crystal layer 5 dispersed within the resin layer 2
Since the liquid crystal molecules 5a in the liquid crystal layer 5 are arranged irregularly in a free state, the extraordinary light refractive index of the liquid crystal layer 5 is different from the refractive index of the epoxy resin matrix 2a, and the incident light is divided between the liquid crystal layer 5 and the epoxy resin matrix 2a. The light is scattered or refracted at the interface, enters the liquid crystal layer 5, is further scattered within the liquid crystal layer 5, and comes out of the liquid crystal layer 5 in all directions, creating a light scattering state. The entire sub-light sheet 1 becomes cloudy like ground glass. On the other hand, when a voltage is applied between the patterned transparent electrode 3 and the planar transparent electrode 4 as shown in FIG. 4, an electric field is generated in the pattern or design pattern of the patterned transparent electrode 3, and the liquid crystal layer The liquid crystal molecules 5a in the liquid crystal layer 5 are aligned, and the difference between the normal optical refractive index of the liquid crystal layer 5 and the refractive index of the epoxy resin matrix 2a becomes zero or extremely small, and the two become optically the same or similar substances. Therefore, the resin layer 2 changes from a light-scattering state to a light-transmitting state, becomes transparent according to the pattern or design pattern of the patterned transparent electrode 3, and maintains a cloudy state in other parts. In this case, since the liquid crystal layer 5 formed by the phase separation method in the aliphatic epoxy resin matrix 2a has a substantially constant size of about 1 μm, it is possible to obtain a good light scattering state and at the same time It can be brought into a light-transmitting state with a practical voltage of . Moreover, the patterned light control sheet 1 of the present invention
The hardened epoxy resin matrix 2a and the liquid crystal layer 5
Since the difference from the normal optical refractive index of The contrast between the light transmission state and the light scattering state is improved.

Next, a second embodiment of the patterned light control sheet of the present invention is shown in FIG. 3, a transparent base material 11a having a planar transparent electrode 11 formed on the other surface is laminated, and the transparent base material 11a is stacked on the other side, and between the planar transparent electrode 4 on the lower surface side of the resin layer 2 and the planar transparent electrode 11 or with the pattern transparent electrode 3. Wiring is performed so that a voltage can be selectively applied between the two. Other configurations are the patterned light control sheet 1 above.
Since it is the same as that, the same reference numerals are given to the same members and the description thereof will be omitted.

In the patterned light control sheet 10 of the present invention, if no voltage is applied between the transparent electrodes 3.4 and between the planar transparent electrodes 4.11 sandwiching the resin layer 2, the pattern light control sheet 10 of the present invention
Similarly, the resin layer 2 is in a light scattering state, and the entire resin layer 2 is cloudy like ground glass. In this state, the transparent electrode 3.4
When a voltage is applied to the selected area, an electric field is generated in the pattern or pattern of the patterned transparent electrode 3, which changes from a light scattering state to a light transmitting state and becomes transparent, similar to the patterned light control sheet 1, and the other parts become transparent. It will remain cloudy. On the other hand, when a voltage is selectively applied between the planar transparent electrodes 4 and 11, the entire resin layer 2 changes from a light scattering state to a light transmitting state, and the entire patterned light control sheet 10 becomes transparent. Therefore, when selecting between the transparent electrodes to which a voltage is applied, there are three types of light transmission: the whole is transparent, only the pattern or design pattern formed on the patterned transparent electrode 3 is transparent and the other parts are cloudy, and the whole is cloudy. This results in a patterned light control sheet 10 that can form a state. Note that it is necessary to use a film as thin as possible for the transparent base material 3a so that it becomes an insulating layer.

Furthermore, the patterned light control sheet 20 shown in FIG. A transparent base material 2 on which a patterned transparent electrode 21 having a pattern or design pattern different from the patterned transparent electrode 3 is formed on its surface.
1a are stacked. And this pattern light control sheet 2
0 is wired so that a voltage can be selectively applied between the patterned transparent electrodes 3321, between the transparent electrodes 3.22, between the transparent electrodes 11.21, and between the planar transparent electrodes 11.22, which sandwich the resin layer 2 therebetween. Other configurations are the patterned light control sheet 10 above.
Since it is the same as that, the same reference numerals are given to the same members and the description thereof will be omitted.

In this patterned light control sheet 20, if no voltage is applied between any of the transparent electrodes, the resin layer 2 will be in a light scattering state as described above, and the patterned light control sheet 20 will be completely cloudy. There is. When a voltage is selectively applied between the transparent electrodes 3 and 22, an electric field is generated in the pattern or design pattern formed on the patterned transparent electrode 3, changing to a light transmitting state and becoming transparent, while the other parts are in a cloudy state. It will remain as it is. Also,
When a voltage is selectively applied between the transparent electrodes 11 and 21, an electric field is generated in the pattern or pattern of the patterned transparent electrodes 21, which becomes transparent, and the other parts remain cloudy. Furthermore, when a voltage is applied selectively between the patterned transparent electrodes 3.21, an electric field is generated only in the overlapping portion of the patterned transparent electrodes 3 and 21 with the resin layer 2 in between, and the pattern of the patterned transparent electrodes 3.21 is Alternatively, only the common part of both patterns, which is different from the design pattern, becomes transparent, and the other parts become cloudy.

Furthermore, when a voltage is selectively applied between the planar transparent electrodes 11 and 21, the entire patterned light control sheet 20 enters a light transmitting state and becomes transparent. Therefore, in this patterned light control sheet 20, when selecting between the transparent electrodes to which a voltage is applied, there are five types: the whole is transparent, three types of patterns or design patterns are transparent and the other parts are cloudy, and the whole is cloudy. Since a light transmitting state can be obtained, the light control sheet has a richer variety of patterns.

Further, the patterned light control sheet 30 shown in FIG. 7 has two layers of resin Fi2.2', and has planar transparent electrodes 4.2 on both sides.
A resin layer 2.2' is formed above and below a transparent base material 4a having a shape of 4', patterned transparent electrodes 3°31 with different patterns or patterns are formed on one side, and a planar transparent electrode 1 is formed on the other side.
Transparent base materials 3a, 31a on which 1.11' are formed, and a transparent resin plate 8.8 on which an acrylic film 7.7 is laminated are sequentially laminated. And this pattern light control sheet 30
is between the planar transparent electrodes 4.11, between the transparent electrodes 3.4, between the planar transparent electrodes 4' and 11', between the transparent electrodes 31.4', between the patterned transparent electrodes 3.31 and the planar transparent electrodes 11.11. The wires are wired so that a voltage can be applied selectively between the two.

In this patterned light control sheet 30, if no voltage is applied between any of the transparent electrodes, both the resin layers 2 and 2' will be in a light scattering state, so that the entire patterned light control sheet 30 will become cloudy. However, between the transparent electrodes 3°4 and the planar transparent electrodes 4' and 1
When a voltage is applied by selecting a voltage between 1', the entire surface of the resin layer 2' becomes transparent and becomes transparent, and the resin layer 2 generates an electric field in the pattern or design pattern of the patterned transparent electrode 3 and becomes transparent. The area becomes cloudy, and the patterned light control sheet 30 becomes transparent in the pattern or design pattern of the patterned transparent electrode Bi3. Furthermore, when voltage is applied by selecting between the transparent electric bridges 3 and 4' and between the planar transparent molds 14 and 11, the entire surface of the resin layer 2 becomes transparent, and the resin layer 2' has the pattern of the patterned transparent electrode 31. Alternatively, the pattern light control sheet 30 becomes transparent in the pattern of the pattern, and the other parts become cloudy, and the pattern light control sheet 30 becomes transparent in the pattern of the pattern transparent electrode 31 or the pattern. Furthermore, when a voltage is applied by selecting between the patterned transparent electric bridges 3 and 31, each patterned transparent electrode 3.3
An electric field is generated in the overlapping part of the pattern or design pattern of 1,
This overlapping portion becomes another pattern or design pattern, resulting in a pattern light control sheet 30 in which the resin layer 2.2' is transparent. Then, when a voltage is selectively applied between the planar transparent electrodes 11 and 11', both the resin layers 2 and 2' become transparent, and the entire surface of the patterned light control sheet 30 becomes transparent. Therefore, this patterned light control sheet 30 can realize five types of light transmission states: a cloudy state, a state where three types of patterns or design patterns are transparent and the other parts are cloudy, and a state where the entire sheet is transparent.

Here, when a plurality of resin layers 2 having three types of transparent electrodes formed on both sides are combined as in the patterned light control sheet 30, a patterned light control sheet is obtained which allows a plurality of types of transparent patterns or design patterns. However, when forming transparent electrodes on both sides of the transparent base material 3a, etc., and applying a voltage between the outer transparent electrode and the transparent electrode formed with the resin layer 2 in between, the transparent base material 3a... If the thickness of the material 3a exceeds approximately 50 μm, voltage application will be insufficient, so it is preferably several μm thick.
It is preferable that the transparent base material 3a is as thin as the following.

[Effects of the Invention] As is clear from the above description, in the patterned light control sheet of the present invention, when a voltage is applied between the transparent electrodes, an electric field is generated according to the pattern of at least one of the transparent electrodes, and the electric field in the resin layer is Only the resin layer in the covered portions changes from a light scattering state to a light transmitting state and becomes transparent in a pattern, resulting in the effect that a pattern or design pattern can be easily formed over a wide range.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a patterned resin sheet according to an embodiment of the present invention, Fig. 2 is a schematic vertical cross-sectional view of a patterned light control sheet of the same embodiment, and Figs. 3 and 4 are respectively shown when no voltage is applied. FIG. 5 is a schematic cross-sectional view of a patterned light control sheet according to another embodiment of the present invention, and FIG. 6 is a schematic cross-sectional view of a patterned light control sheet according to another embodiment of the present invention. FIG. 7 is a schematic sectional view of a schematic light control sheet according to another embodiment of the present invention. 1.10.20.30... Pattern light control sheet 2.2'.
...Resin layer 2a...Resin matrix 5...Liquid crystal droplets

Claims (1)

[Claims] (1) A patterned light control sheet, characterized in that transparent electrodes are formed on both sides of a resin layer in which liquid crystals are dispersed in a resin matrix, and at least one of the transparent electrodes is patterned.