JP3270195B2 - Light control component - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light control structure capable of controlling light transmittance by controlling the temperature of a light control layer.

[0002]

2. Description of the Related Art The absorptivity of thermochromic compounds such as spiropyran solution changes with temperature. Taking advantage of this property, a thermochromic compound such as a spiropyran solution can be used as the light control layer of the light control structure. By controlling the temperature of the light control layer, the light transmittance of the light control component obtained in this manner can be controlled.

[0003]

A conventional dimming structure using a thermochromic compound such as a spiropyran solution has a narrow wavelength range in which the light absorption can be changed.
Further, there is a problem that the wavelength is also limited to a specific wavelength.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and in a light control structure capable of controlling the light transmittance by controlling the temperature of a light control layer, the light absorption rate increases in response to a rise in temperature. It is an object of the present invention to obtain a dimming component that can freely control the absorption wavelength range to be controlled and that can easily increase the dimming area.

[0005]

SUMMARY OF THE INVENTION A dimming structure according to the present invention comprises:
In a light control structure capable of controlling light transmittance by controlling the temperature of the light control layer, at least one of the light control layers includes a liquid crystal layer as a light control layer between two transparent substrates, and the liquid crystal layer has a P layer. A layer in which a liquid crystal material containing 0.05 to 10% by weight of a dichroic dye is oriented in a direction perpendicular to the substrate surface.
And align the liquid crystal layer perpendicular to the substrate surface
An alignment film on the substrate surface in contact with the liquid crystal layer
And at least one of the alignment films is a non-light-modulating structure.
Mainly ruphenoxy polyethylene glycol acrylate
Polymerizing and curing the polymer resin-forming monomer liquid as a component
It is characterized by being formed by a polymer resin film composed of:

That is, in the thus formed structure, the liquid crystal layer as a light control layer is in a vertical alignment state. The term “vertical” here means that the liquid crystal is 5
It refers to having an orientation angle in the range of 0 to 90 degrees. By the way, in the structure of the present invention, the liquid crystal is set at 70 degrees to 90 degrees.
It is more preferred to have an orientation angle in the range of degrees.

[0007] The long axis of the dichroic dye molecules contained in the liquid crystal layer in the vertical alignment state is aligned perpendicular to the substrate surface like the liquid crystal molecules. This P-type dichroic dye has a light absorption anisotropy with a large light absorption in the molecular long axis direction. Then, when the molecular long axis of the P-type dichroic dye is oriented perpendicular to the substrate surface, the light absorptivity for light incident perpendicular to the substrate is minimized.

Here, when the temperature of the liquid crystal layer is increased, the liquid crystal layer undergoes a phase transition to an isotropic phase. And 2 contained in the liquid crystal layer
The orientation state of the molecular long axis of the chromatic dye also becomes isotropic. For this reason, the light absorptance increases as compared with the vertical alignment. That is, the light transmittance of the light modulating component decreases in response to the temperature rising to the region where the liquid crystal layer exhibits the isotropic phase.

At that time, if the content of the dichroic dye contained in the liquid crystal layer of the light modulating component is too large, the liquid crystal layer will not show a nematic phase. If the amount is too small, the change width of the light absorption of the liquid crystal layer corresponding to the temperature will be small. Therefore, the amount of the P-type dichroic dye contained in the liquid crystal material forming the liquid crystal layer needs to be 0.05 to 10% by weight.

As the dichroic dye used in the present invention, any p-type dichroic dye for liquid crystal use can be used without particular limitation. Examples thereof include dichroic dyes such as anthraquinone dyes, azo dyes, quinophthalone dyes, berylen dyes, coumarin dyes, thioindigo dyes, merocyanine dyes, styryl dyes, and oxonol dyes. Further, these dichroic dyes can be appropriately blended and used as needed. In this case, it is used in consideration of the absorption wavelength range of each dichroic dye to be blended.

That is, if the type of dichroic dye to be contained in the liquid crystal layer is selected, the absorption wavelength range can be set.
It is possible to freely control the absorption wavelength range in which the light absorption rate increases in response to the temperature rise. Here, the dichroic dye contained in the liquid crystal layer may be a single type or a mixture of two or more types having different absorption wavelengths.

It is more preferable that the P-type dichroic dye used in the present invention has a larger dichroic ratio, which is a ratio of the light absorptivity in the minor axis direction to the major axis direction.

Commercially available dichroic dyes include, for example, "SI-497" (blue dye) and "M" manufactured by Mitsui Toatsu Dye Co., Ltd.
-137 "(blue pigment)," M-483 "(blue pigment),
“SI-426” (red pigment), “S-416” (black pigment), “S-344” (black pigment) and “L” manufactured by Nippon Kayaku Co., Ltd.
CD-118 "(blue pigment)," LCD-208 "(red pigment)," LCD-465 "(black pigment)," CLD-506 "(blue pigment) manufactured by Sumitomo Chemical Co., Ltd., and the like.

In the present invention, the liquid crystal layer undergoes a phase transition to an isotropic phase, thereby increasing the light absorptivity of the structure. Therefore, the selection of the liquid crystal material is performed in consideration of the operating temperature range according to the use of the constituent body and the phase transition temperature of the liquid crystal to an isotropic phase. In the present invention, a general nematic liquid crystal or the like can be used, and as a commercial product, for example, an E7 liquid crystal manufactured by Merck can be used.

The liquid crystal layer in the present structure must exhibit a vertical alignment state with respect to the substrate surface below the phase transition temperature to the isotropic phase. As a method of liquid crystal alignment treatment for the nematic liquid crystal layer to show a vertical alignment state with respect to the substrate surface, a method of forming an organic alignment film on the substrate surface is used.
You.

[0016]

[0017] In the method for forming the liquid crystal layer showing such vertical alignment state, as a way that form a liquid crystal layer of the structure, the organic alignment film is formed on the substrate surface in contact with the liquid crystal layer, as the liquid crystal material This is a method using a nematic liquid crystal containing a dichroic dye. In this method, in general, the temperature region where the light absorption is minimized can be widened by using a nematic liquid crystal, and the formation of an organic alignment film can be easily performed with a large area as compared with other liquid crystal alignment means. It has the advantage that the property is stable.

Nonylphenoxypolyethylene glycol acrylate is used as an organic alignment film material for this purpose.
-Polymerization of polymer resin-forming monomer liquid mainly containing
A cured polymer resin film or the like can be used. So
And place it on at least one substrate surface in contact with the liquid crystal layer.
To vertically align the liquid crystal layer of the present structure.
It is preferable to use it as an alignment film.

[0019]

[0020]

[0021]

The above polymer resin film-forming monomer liquid is
Alignment for orienting the liquid crystal layer in the vertical direction by applying it to the substrate surface using a spin coater, bar coater, etc., and then polymerizing and curing using an ultraviolet curing method or thermal polymerization method. A film can be formed on the substrate.

In the present invention, at least one of the substrates must have transparency, and the light control layer sandwiched between the two substrates must be visible from the outside. However, complete transparency is not essential. If the dimming component is used to act on light passing from one side of the component to the other, it is preferred that both substrates have adequate transparency.

Such a substrate may be a rigid material, for example, glass or metal, or a flexible material, for example, a plastic film. In the case of a flexible substrate material such as a plastic film, the substrate can be fixed to a rigid material, for example, glass, metal, or the like, and then used in the manufacturing method of the present invention.

The two substrates are opposed to each other and are obtained at an appropriate interval. At that time, it is desirable to interpose a spacer for maintaining a space between the two substrates.
As the spacer, for example, polymer resin spheres such as glass beads and polystyrene, metal spheres, mylar, alumina and the like for liquid crystal cells can be used without any particular limitation.

The thickness of the liquid crystal layer of the light control component of the present invention is desirably in the range of 1 to 100 μm.

In the dimming structure of the present invention, a heat generating layer is provided on at least one substrate or in contact with the substrate.
If the liquid crystal layer can be freely heated, the liquid crystal layer can be heated to the phase transition temperature to the isotropic phase, whereby the optical absorptance of the structure can be artificially increased. The heating layer in this application does not necessarily have to be transparent, but if the dimming component is used to act on light passing from one side of the component to the other side In this case, it is preferable that the heat generating layer has appropriate transparency.

Here, as the transparent heat generating layer, for example, a metal thin film layer of silver or the like formed to a thickness of about 10 nm by a vacuum sputtering method is sandwiched between dielectric layers of titanium oxide or the like from above and below. A stacked body or the like can be used, and the stacked body can be heated by applying a current to the metal thin film layer in the stacked body.

Hereinafter, an application example in the case where the light control component of the present invention is actually used will be described. However, the invention is not limited to these applications.

The present invention has a function of increasing the light absorptance of the structure in response to a rise in the temperature of the liquid crystal layer. Therefore, when used in a lighting part such as a window in a car such as a building or an automobile or a railway, the temperature of the liquid crystal layer also increases in a state where the room temperature is high, and when the temperature reaches a phase transition temperature region to an isotropic phase, The light absorption of the construct increases sharply. At this time, the component absorbs much of the light, such as sunlight, that enters the room, prevents the flow of light energy into the room, and suppresses the temperature rise in the room. This function is equivalent to an automatic temperature control function in the room, and an energy saving effect such as a reduction in power consumption associated with the operation of the cooling device can be obtained by using the light control structure. it can.

As described above, by adding a heat generating layer portion to the dimming structure of the present invention so that the liquid crystal layer can be freely heated, for example, the structure can be applied to the entire surface of the windshield of an automobile or the like. When partially used, when the driver feels dazzling sunlight coming from the front, etc., if the light absorptance of the component is increased by operating the heating layer to generate heat, the light entering from the front can be reduced. Many can be blocked. That is, the driver can continue driving comfortably without having to wear sunglasses or the like.

[0032]

Example 1 One example of the light control component of the present invention was manufactured and evaluated as follows. FIG. 1 is a schematic cross-sectional view of a light control component according to an example. FIGS. 2 and 3 show changes in transmittance when the dimming components in Examples 1 and 2 were evaluated. In FIG. 1, 1 is a substrate, 2 is an alignment film, and 3 is a liquid crystal layer as a light control layer. 2 and 3, the horizontal axis indicates the measurement wavelength (nm), and the vertical axis indicates the transmittance (%).

At the time of evaluation, the measurement of the light absorptivity of the present structure was performed indirectly by measuring the transmittance of light passing through the present structure. The measurement light beam was made to enter the liquid crystal layer of the present structure from a vertical direction. The measurement of the light transmittance and the light transmission spectrum was performed using an instantaneous multi-photometry system “Photoal MCPD-1000” type manufactured by Otsuka Electronics Co., Ltd.

First, in Example 1, as a liquid crystal material, 99.0% by weight of a nematic liquid crystal (E7 liquid crystal manufactured by Merck, a nematic-isotropic phase transition temperature of 61 ° C.) was used, and a p-type dichroic dye (Mitsui A mixture of 1.0% by weight of K-Dye Co., Ltd. M-483) was used.

As a means for vertically aligning the liquid crystal layer, an organic alignment film 2 was formed on two transparent glass substrates 1. For this purpose, nonylphenoxy polyethylene glycol acrylate (Aronix M-11 manufactured by Toa Gosei Chemical Industry Co., Ltd.) is used.
19.5 parts by weight of 100 parts by weight of 1) and 19.5 parts by weight of pentaerythritol tetraacrylate (PE4A manufactured by Kyoeisha Yushi Kagaku Kogyo Co., Ltd.), and benzyldimethylketal (Ciba-Geigy) as a polymerization initiator A mixture comprising 0.5% by weight of Irgacure 651),
It was used as an organic alignment film forming monomer liquid.

After this is uniformly coated on two substrates 1, the light intensity is about 10 mW / cm 2 in a nitrogen atmosphere.
Irradiation of ultraviolet light for about 10 minutes
The liquid was polymerized and cured to form a resin film having a thickness of about 80 nm, which was used as an alignment film 2.

Next, two substrates were bonded together via a spacer so that the surfaces of the liquid crystal alignment films formed previously faced each other, thereby producing a glass cell having a substrate interval of about 12 μm. The liquid crystal material was injected into this glass cell to form a liquid crystal layer 3 as a light control layer.

First, the light transmission spectrum of the structure was measured at room temperature. This measurement result is shown by a solid line in the graph of FIG. Thereafter, the light transmission spectrum of the structure was measured with the structure heated to 65 ° C. This measurement result is indicated by a broken line in the graph of FIG.

As shown in FIG. 2, the light transmittance of this structure at a wavelength of 600 nm was about 61% at room temperature and about 25% at 65 ° C. That is, the light absorption at room temperature was low, and the light absorption at 65 ° C. was high. The light transmission spectrum of the present structure showed the same absorptivity change characteristics even when the temperature of the structure was repeatedly heated and cooled between room temperature and 65 ° C. several times.

The present structure visually exhibits a blue color, and the shade of the blue color changes between room temperature and 65 ° C. That is, it exhibits a deep blue color at 65 ° C.

[0041]

EXAMPLE 2 A liquid crystal material was composed of 98.0% by weight of a nematic liquid crystal (E7 liquid crystal manufactured by Merck, nematic-isotropic phase transition temperature of 61 ° C.) and a P-type dichroic dye (Mitsui Toatsu Dyeing Co., Ltd.). Manufactured by S-416) was well mixed with 2.0% by weight.

As a means for vertically aligning the liquid crystal layer, an organic alignment film 2 was formed on two transparent glass substrates 1. For this purpose, nonylphenoxy polyethylene glycol acrylate (Aronix M-11 manufactured by Toa Gosei Chemical Industry Co., Ltd.) is used.
19.5 parts by weight of 100 parts by weight of 1) and 19.5 parts by weight of pentaerythritol tetraacrylate (PE4A manufactured by Kyoeisha Yushi Kagaku Kogyo Co., Ltd.), and benzyldimethylketal (Ciba-Geigy) as a polymerization initiator A mixture comprising 0.5% by weight of Irgacure 651),
It was used as an organic alignment film forming monomer liquid.

After this was uniformly applied on two substrates 1, the light intensity was about 10 mW / cm 2 in a nitrogen atmosphere.
Irradiation of ultraviolet light for about 10 minutes
The liquid was polymerized and cured to form a resin film having a thickness of about 80 nm, which was used as an alignment film 2.

Next, two substrates were bonded via a spacer so that the surfaces of the previously formed liquid crystal alignment films faced each other, thereby producing a glass cell having a substrate interval of about 12 μm. The liquid crystal material was injected into this glass cell to form a liquid crystal layer 3 as a light control layer.

First, the light transmission spectrum of the structure was measured at room temperature. This measurement result is shown by a solid line in the graph of FIG. Thereafter, the light transmission spectrum of the structure was measured while the structure was heated to 65 ° C. This measurement result is indicated by a broken line in the graph of FIG.

As shown in FIG. 3, the light transmittance of the present structure at a wavelength of 600 nm is about 64% at room temperature and about 24% at 65 ° C., and the light transmittance of the present structure at a wavelength of 500 nm is It was about 62% at room temperature and about 18% at 65 ° C.

That is, as shown in the light transmission spectrum of FIG. 3, over a wide absorption wavelength range, the light absorption at room temperature was low and the light absorption at 65 ° C. was high. The light transmission spectrum of the present structure showed the same absorptivity change characteristics even when the temperature of the structure was repeatedly heated and cooled between room temperature and 65 ° C. several times.

The present structure visually appears black, and the density of the black color changes between room temperature and 65 ° C. That is, it exhibits a deep black color at 65 ° C.

[0049]

As described above in detail, the light control component of the present invention has a light absorption rate which increases in response to a rise in temperature, and freely controls an absorption wavelength range in which the light absorption rate can be changed. It has a function to do. In addition, since the configuration is simple and suitable for increasing the area, the light control component can be widely used in industrial fields and the like.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a light control component.

FIG. 2 shows the results of transmittance change measurement of Example 1.

FIG. 3 is a measurement result of transmittance change in Example 2.

[Explanation of symbols]

 Reference Signs List 1 substrate 2 alignment film 3 liquid crystal layer

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kenji Nakatani 4-3-2 Asahigaoka, Hino-shi, Tokyo Teijin Limited Tokyo Research Center (56) References JP-A-57-129413 (JP, A) JP-A-58-152221 (JP, A) JP-A-58-150935 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02F 1/13 102 G02F 1/1337 520 G02F 1 / 137 500

Claims (2)

(57) [Claims] 1. By controlling the temperature of the light control layer,
In a light control component capable of controlling light transmittance, at least one of the light control components includes a liquid crystal layer as a light control layer between two transparent substrates, and the liquid crystal layer contains a P-type dichroic dye in an amount of 0.05 to 10%. A layer in which a liquid crystal material containing 5% by weight is oriented in a direction perpendicular to the substrate surface , and the liquid crystal layer is oriented in a direction perpendicular to the substrate surface.
An alignment film for orienting the liquid crystal layer in contact with the liquid crystal layer.
Dimming structure provided on the substrate surface, at least one of
The alignment film is made of nonylphenoxypolyethylene glycol
Polymer resin-forming monomer liquid containing acrylate as a main component
Formed by polymer resin film obtained by polymerizing and curing
The liquid crystal light control structure. 2. The liquid crystal light control structure according to claim 1 , wherein a heat generation layer is provided on at least one of the substrates as means for controlling the temperature of the liquid crystal layer as the light control layer.