JP7187947B2 - Light control sheet and light control glass - Google Patents

Description

The present invention relates to a light control sheet and light control glass.

The light control sheet includes a light control layer containing a liquid crystal composition and a pair of transparent electrode layers sandwiching the light control layer. When a driving voltage is applied between the pair of transparent electrode layers, the orientation of the liquid crystal molecules changes from the first orientation before the application to the second orientation after the application. The light modulating layer transmits light incident on the light modulating layer when the orientation of the liquid crystal molecules is one of the first orientation and the second orientation, and transmits light when the liquid crystal molecules are in the other of the first orientation and the second orientation. It scatters the light incident on the light layer.

The liquid crystal layer can contain a dichroic dye as an element constituting a liquid crystal composition. A light control sheet having a liquid crystal layer containing a dichroic dye is a guest-host type light control sheet. Since the guest-host type light control sheet can exhibit a color corresponding to the dichroic dye, the design of the light control sheet is enhanced (see, for example, Patent Document 1).

JP 2010-230759 A

However, there is a limit to the amount of dichroic dye that can be uniformly distributed in the liquid crystal composition. If the content of the dichroic dye is increased to obtain the desired density, the density of the dichroic dye will vary within the plane of the liquid crystal layer. As a result, the color displayed by the light control sheet becomes uneven depending on the density difference of the dichroic dye. In addition, since dichroic dyes have low light resistance and are easily faded, the influence of dichroic dyes on the long-term reliability of light control sheets is extremely large.

An object of the present invention is to provide a light control sheet and a light control glass that are capable of suppressing color unevenness exhibited by a light control layer and improving long-term reliability.

A light control sheet for solving the above problems comprises a light control layer containing a liquid crystal composition, a pair of transparent electrode layers sandwiching the light control layer in the thickness direction of the light control layer, and at least one colored transparent electrode layer. and a colored layer. The pair of transparent electrode layers is composed of a first transparent electrode layer and a second transparent electrode layer. The colored layer is located on at least one of the side opposite to the light control layer with respect to the first transparent electrode layer and the side opposite to the light control layer with respect to the second transparent electrode layer.

A light control sheet for solving the above problems includes a light control layer containing a liquid crystal composition, and a pair of transparent electrode layers sandwiching the light control layer in the thickness direction of the light control layer. The pair of transparent electrode layers is composed of a first transparent electrode layer and a second transparent electrode layer. At least one of the first transparent electrode layer and the second transparent electrode layer is colored transparent.

A light control glass for solving the above problems includes the light control sheet, a pair of glass substrates sandwiching the light control sheet in the thickness direction of the light control sheet, and at least one intermediate film. . The pair of glass substrates comprises a first glass substrate and a second glass substrate. The intermediate film is positioned between the first glass substrate and the light control sheet and has an adhesive property for bonding the first glass substrate to the light control sheet; and the second glass. At least one of a film having an adhesive property that is positioned between the substrate and the light control sheet and bonds the second glass substrate to the light control sheet.

A light control glass for solving the above problems is a light control sheet including a light control layer containing a liquid crystal composition and a pair of transparent electrode layers sandwiching the light control layer in the thickness direction of the light control layer. and a pair of glass substrates sandwiching the light control sheet in the thickness direction of the light control sheet, at least one intermediate film, and a colored transparent colored layer. The pair of glass substrates comprises a first glass substrate and a second glass substrate. The intermediate film is positioned between the first glass substrate and the light control sheet and has an adhesive property for bonding the first glass substrate to the light control sheet; and the second glass. It is any one of adhesive films positioned between a base material and the light control sheet and bonding the second glass base material to the light control sheet.

According to each of the above configurations, the light control sheet and the light control glass provided with the light control sheet can exhibit a color in which the color exhibited by the light control layer and the color exhibited by the colored layer are superimposed. Therefore, the occurrence of unevenness in the color exhibited by the light-modulating layer can be suppressed as compared with the case where the color exhibited by the light-modulating layer and the color exhibited by the colored layer are superimposed with the color exhibited by the light-modulating layer alone. . Moreover, since the light control sheet and the light control glass can be colored without using a dichroic dye, the long-term reliability of the light control sheet and the light control glass can be improved.

In the light control sheet, the liquid crystal composition contains a plurality of liquid crystal molecules, and the plurality of liquid crystal molecules is in a first alignment state and a second alignment state that are switched depending on whether or not a driving voltage for driving the liquid crystal molecules is applied. wherein the first alignment state is a state in which the transmittance is higher than that of the second alignment state, and the colored layer is a visible light of the light control sheet when the liquid crystal molecules are in the first alignment state. The light transmittance is 15% or more, and the light control sheet has a visible light transmittance of 2% or less when the liquid crystal molecules are in the second alignment state. may absorb light with a wavelength of

In the light control sheet, the colored layer may have a Munsell brightness of 1 or more and 5 or less.
According to each of the above configurations, not only in the second orientation state but also in the first orientation state, the visibility from one side to the other through the light control sheet and the visibility from the other side to the other side can be reduced. can.

In the light control sheet, the colored layer may be either the first base material supporting the first transparent electrode layer or the second base material supporting the second transparent electrode layer. According to the above configuration, since the substrate supports and colors the transparent electrode layer, there is no need to add a layer different from the substrate for coloring or supporting. Therefore, the thickness of the light control sheet can be prevented from increasing, and the light control sheet can exhibit a color corresponding to the wavelength band absorbed by the base material.

In the light control sheet, the colored layer is a layer that sandwiches the first base material supporting the first transparent electrode layer with the first transparent electrode layer in the thickness direction, or a layer that sandwiches the second transparent electrode layer. It may be any layer that sandwiches the supporting second substrate together with the second transparent electrode layer in the thickness direction. According to the above configuration, since the colored layer is provided as a separate layer from the pair of transparent substrates, the degree of freedom of the material forming the colored layer can be increased compared to the case where the substrate also functions as the colored layer. can be done.

According to the present invention, it is possible to suppress color unevenness exhibited by the light-modulating layer, and to improve long-term reliability.

Sectional drawing which shows the structure of the light control sheet in the 1st example of one Embodiment. Sectional drawing which shows the structure of the light control sheet in the 2nd example of one Embodiment. Sectional drawing which shows the structure of the light control sheet in the 3rd example of one Embodiment. Sectional drawing which shows the structure of the light control glass in the 1st example of one Embodiment. Sectional drawing which shows the structure of the light control glass in the 2nd example of one Embodiment. FIG. 4 is an operation diagram for explaining the operation when the light control sheet of the embodiment is applied to a vehicle window;

An embodiment of the light control sheet and the light control glass will be described with reference to FIGS. 1 to 6. FIG. The configuration of the light control sheet, the configuration of the light control glass, and the action of the light control sheet will be described below in order.

[Configuration of light control sheet]
The configuration of the light control sheet will be described with reference to FIGS. 1 to 3. FIG. Three examples of the configuration of the light control sheet are shown below.

[Light control sheet of the first example]
As shown in FIG. 1 , the light control sheet 10 of the first example includes a light control layer 11 , a pair of transparent electrode layers 12 and a pair of substrates 13 . The light control layer 11 contains a liquid crystal composition. The pair of transparent electrode layers 12 sandwich the light control layer 11 in the thickness direction of the light control layer 11 . The pair of substrates 13 sandwich the pair of transparent electrode layers 12 in the thickness direction of the light control layer 11 . In the light control sheet 10, the pair of transparent electrode layers 12 is composed of a first transparent electrode layer 12a and a second transparent electrode layer 12b. The pair of base materials 13 is composed of a first base material 13a and a second base material 13b. In the light control sheet 10 of this example, either the first base material 13a or the second base material 13b may be colored transparent, or both the first base material 13a and the second base material 13b may be colored transparent. It's okay.

That is, in the light control sheet 10 of this example, either the first base material 13a or the second base material 13b may be an example of the colored layer, or both the first base material 13a and the second base material 13b may be an example of a colored layer.

The light control sheet 10 can exhibit a composite color in which the color exhibited by the light control layer 11 and the color exhibited by the base material 13 functioning as a colored layer are overlapped. Therefore, compared with the case where the composite color is realized only by the color of the light control layer 11, the unevenness of the color of the light control layer 11 can be suppressed. Further, since the substrate 13 supports and colors the transparent electrode layer 12, it is not necessary to add a layer different from the substrate 13 for coloring or supporting. Therefore, the thickness of the light control sheet 10 can be prevented from increasing, and the light control sheet 10 can exhibit a color corresponding to the wavelength band absorbed by the base material 13 .

The light control layer 11 contains the liquid crystal composition as described above. The liquid crystal composition contains at least a plurality of liquid crystal molecules. The orientation of the plurality of liquid crystal molecules changes depending on whether or not a drive voltage for the liquid crystal molecules is applied to the light control layer 11 via the pair of transparent electrode layers 12 . The light control layer 11 may be, for example, a polymer network liquid crystal layer (PNLC). In this case, the light modulating layer 11 contains a polymer network and a liquid crystal composition. A polymer network has a three-dimensional mesh shape and partitions a plurality of domains. A liquid crystal composition is filled in each domain. The liquid crystal composition may contain a monomer for forming a polymer network in addition to the liquid crystal molecules.

Each transparent electrode layer 12 may be, for example, a layer formed from a transparent conductive oxide. Transparent conductive oxides can be, for example, ITO, ZAO, or SnO ₂ . Each transparent electrode layer 12 may be, for example, a layer formed from a conductive polymer. The conductive polymer may be PEDOT, for example.

Each substrate 13 includes a light transmissive matrix, whether or not it functions as a color layer. The light-transmitting base material may be various synthetic resins. The synthetic resin may be, for example, polycarbonate, polyethylene, polypropylene, polyethylene terephthalate, polyethylene naphthalate, or vinyl chloride resin.

The base material 13 functioning as a colored layer contains a pigment as an additive in addition to the base material described above. The dye absorbs light of wavelengths corresponding to predetermined light contained in the visible light region. A pigment may be, for example, a dye or a pigment. Depending on the color exhibited by the substrate 13, the wavelengths absorbed by the dyes can be selected. When the substrate 13 exhibits a red color, for example, the wavelength of the light absorbed by the pigment can be set to a wavelength band including green light. When the base material 13 exhibits a blue color, for example, the wavelength of light absorbed by the dye can be set to a wavelength band including yellow light. When the substrate 13 exhibits a black color, for example, the wavelength band of light absorbed by the pigment can be the entire visible light region. If the substrate 13 exhibits a red color, the dye may be gold, for example. When the base material 13 exhibits a black color, the base material 13 may contain, for example, metal compounds such as iron oxide (Fe ₂ O ₃ ) and cobalt oxide (CoO), carbon, or silver.

The substrate 13 functioning as a colored layer may be composed of a resin layer and a pigment layer. The resin layer is a synthetic resin layer formed from the base material described above. The dye layer can be positioned on at least one of the two opposing surfaces of the resin layer. The dye that forms the dye layer may be a dye that is mixed with the matrix.

The base material 13 has a size that covers the entire light control layer 11 when viewed from the thickness direction of the light control layer 11 . Therefore, when viewed from the thickness direction of the light-modulating layer 11 , the entire light-modulating layer 11 is viewed by an observer as exhibiting a color corresponding to the color exhibited by the base material 13 . Note that the base material 13 functioning as a colored layer may have a size that covers only a part of the light control layer 11 when viewed from the thickness direction of the light control layer 11 . Even in this case, the region of the light-modulating layer 11 covered with the substrate 13 when viewed in the thickness direction of the light-modulating layer 11 should exhibit a color corresponding to the color exhibited by the substrate 13. , is viewed by an observer.

The visible light region mentioned above is 380 nm or more and 780 nm or less. The liquid crystal molecules of the light modulating layer 11 include a first alignment state and a second alignment state that are switched depending on whether or not a driving voltage for driving the liquid crystal molecules is applied. The first alignment state has a higher transmittance than the second alignment state. In the base material 13 in this example, the visible light transmittance of the light control sheet 10 is 15% or more when the liquid crystal molecules are in the first alignment state, and the light control sheet 10 is light control when the liquid crystal molecules are in the second alignment state. The sheet 10 has a visible light transmittance of 2% or less, and can absorb light of a predetermined wavelength in the visible light region. As a result, the visibility from one side to the other through the light control sheet 10 and the visibility from the other side to the other can be reduced not only in the second orientation state but also in the first orientation state.

In the light control layer 11 of this example, the plurality of liquid crystal molecules are randomly arranged in the light control layer 11 when no drive voltage is applied to the light control layer 11 . On the other hand, when a driving voltage is applied to the light control layer 11, the plurality of liquid crystal molecules are arranged such that the long axis of each liquid crystal molecule is substantially perpendicular to the plane on which the light control layer 11 extends. . Therefore, in the light control sheet 10, the transmittance of the light control sheet 10 when the drive voltage is applied to the light control layer 11 is equal to the transmittance of the light control sheet 10 when the drive voltage is not applied to the light control layer 11. higher than transmittance. That is, in this example, when the drive voltage is applied to the light control layer 11, the plurality of liquid crystal molecules are in the first alignment state, and when the drive voltage is not applied to the light control layer 11, A plurality of liquid crystal molecules are in a second alignment state.

The visible light transmittance of the light control sheet 10 can be measured by a method based on JIS S 3107 "6.3 Visible light transmittance test". When only one of the pair of substrates 13 functions as a colored layer, the visible light transmittance described above is realized by one substrate 13 . On the other hand, when both of the pair of substrates 13 function as colored layers, the above-described visible light transmittance is realized by the two substrates 13 sandwiching the light control layer 11 . In this case, the visible light transmittances of the two substrates 13 may be the same or different. The point is that the visible light transmittance described above should be realized by the two substrates 13 .

The colored layer, that is, the Munsell brightness of the substrate 13 in this example can be 1 or more and 5 or less. As a result, the visibility from one side to the other through the light control sheet 10 and the visibility from the other side to the other can be reduced not only in the second orientation state but also in the first orientation state. The Munsell brightness of the base material 13 can be obtained by a method based on JIS Z 8721.

The visible light transmittance and Munsell brightness of the substrate 13 can be adjusted by the following methods. For example, visible light transmittance and Munsell brightness can be adjusted by the type of dye used to form the substrate 13 . Further, for example, the visible light transmittance and Munsell brightness can be adjusted in the base material 13 by adjusting the mass percentage (Mb/Ma×100) of the pigment (Mb) to the mass of the base material (Ma). Further, for example, the visible light transmittance and Munsell brightness of the substrate 13 can be reduced by increasing the percentage of the mass of the dye with respect to the mass of the base material.

[Light control sheet of the second example]
As shown in FIG. 2, the light control sheet 20 of the second example includes a light control layer 11 and a pair of transparent electrode layers 12, like the light control sheet 10 of the first example. The light control sheet 20 of the second example further includes a pair of colored layers 21 and a pair of transparent substrates 22 . A pair of colored layers 21 sandwich a pair of transparent electrode layers 12 . A pair of transparent substrates 22 sandwich a pair of colored layers 21 . Each colored layer 21 is positioned between the transparent electrode layer 12 and the transparent substrate 22 in the thickness direction of the light modulating layer 11 . Although the light control sheet 20 includes a pair of colored layers 21 in this example, the light control sheet 20 may include only one colored layer 21 . When the light control sheet 20 exhibits a black color, the colored layer 21 may be a blackening layer. The blackening layer can be, for example, a chromium layer, a silver layer, or a copper layer.

The light control sheet 20 of the second example can be combined with the configuration of the light control sheet 10 of the first example. More specifically, in addition to the colored layer 21, the light control sheet 20 may include at least one substrate 13 functioning as the colored layer described above. In this case, the colored layer 21 and the substrate 13 constitute a colored layer. Further, in this case, the desired visible light transmittance of the light control sheet 20 can be achieved by cooperation between the colored layer 21 and the substrate 13 .

[Light control sheet of the third example]
As shown in FIG. 3 , the light control sheet 30 of the third example includes a light control layer 11 , a pair of transparent electrode layers 12 , a pair of transparent substrates 31 and a colored layer 32 . In the third example, the light control layer 11 has the same configuration as the light control layer 11 in the first example, and the transparent electrode layer 12 has the same configuration as the transparent electrode layer 12 in the first example. The transparent base material 31 has the same configuration as the transparent base material 22 in the second example.

The colored layer 32 is a layer that sandwiches the second transparent substrate 31b that supports the second transparent electrode layer 12b together with the second transparent electrode layer 12b in the thickness direction. Thus, since the colored layer is provided as a layer separate from the pair of transparent base materials 31, it is possible to increase the degree of freedom in selecting materials for forming the colored layer compared to the case where the base material also functions as a colored layer. can.

The colored layer 32 may be, for example, a colored film. A colored film includes a light-transmissive base material and a pigment. The light-transmitting base material may be a synthetic resin, like the base material 13 of the first example described above. Synthetic resins may be, for example, polycarbonate, polyethylene, polypropylene, polyethylene terephthalate, polyethylene naphthalate, polyphenylene sulfide, polyether ketone, or polyether sulfone. A dye absorbs predetermined light included in the visible light region. A pigment may be, for example, a dye or a pigment. The wavelengths at which the dyes absorb can be selected depending on the color exhibited by the colored film. That is, the coloring matter contained in the colored film may be a coloring matter that the substrate 13 described above can contain.

The colored layer 32 may be, for example, colored glass. Colored glass includes silicon oxide (SiO ₂ ) as a base material and a pigment. The colorant contained in the colored glass may be a colorant that the substrate 13 described above can contain, as in the case of the colored film. When the colored glass exhibits a black color, the pigment contained in the colored glass is preferably iron oxide or cobalt oxide. When the colored glass presents a red color, the pigment contained in the colored glass is preferably gold. By selecting these dyes as dyes for coloring silicon oxide, the coloring properties of the colored glass can be enhanced.

The colored layer 32 may be, for example, a metal thin film. The metal thin film may be, for example, a gold thin film, a silver thin film, an iron thin film, or a copper thin film. The metal thin film may be, for example, a deposited film formed by a vacuum deposition method.

The colored layer 32 may be, for example, an adhesive layer or an adhesive layer. The adhesive layer contains an adhesive and a pigment. The adhesive may be, for example, an epoxy-based resin adhesive, a urethane-based resin adhesive, a melamine-based resin adhesive, or a phenol-based resin adhesive. The pigment may be any pigment that the substrate 13 described above may contain. The adhesive may be, for example, an acrylic resin adhesive or a silicone resin adhesive. The pigment may be any pigment that the substrate 13 of the first example described above can contain.

As described above, the colored layer 32 may have a single-layer structure composed of any one of a colored film, colored glass, metal thin film, adhesive layer, and adhesive layer, or at least one of these A multilayer structure comprising When the colored layer 32 has a multilayer structure, the colored layer 32 can include other layers in addition to any one of the four layers described above. When the colored layer 32 has a multilayer structure, the colored layer 32 may include at least one of a hard coat layer, an ultraviolet shielding layer, an infrared shielding layer, a visible light reflecting layer, an antifouling layer, and a heat insulating layer. can. The ultraviolet shielding layer may be an ultraviolet reflecting layer, an ultraviolet absorbing layer, or a layer having both functions. The infrared shielding layer may be an infrared reflecting layer, an infrared absorbing layer, or a layer having both functions.

Although the light control sheet 30 has only one colored layer 32 in this example, it may have a pair of colored layers 32 . In this case, the light control sheet 30 may include a layer sandwiching the first transparent substrate 31a supporting the first transparent electrode layer 12a together with the first transparent electrode layer 12a in the thickness direction.

When the light control sheet 30 includes a pair of colored layers 32 and the colored layers 32 have a multilayer structure, the layers included in one colored layer 32 and the layers included in the other colored layer 32 are made different from each other. be able to. Thereby, the function of one colored layer 32 and the function of the other colored layer 32 can be made different from each other.

The light control sheet 30 of the third example can be combined with at least one of the configuration of the light control sheet 10 of the first example and the configuration of the light control sheet 20 of the second example. More specifically, the light control sheet 30 may include the base material 13 functioning as a colored layer in the light control sheet 10 of the first example instead of at least one of the pair of transparent base materials. Moreover, the light control sheet 30 may include at least one colored layer 21 included in the light control sheet 20 of the second example. Further, the light control sheet 30 may include both the base material 13 functioning as the colored layer in the light control sheet 10 of the first example and the colored layer 21 .

[Configuration of light control glass]
The configuration of the light control glass will be described with reference to FIGS. 4 and 5. FIG. Two examples of the configuration of the light control glass are shown below.

[Light control glass of the first example]
As shown in FIG. 4 , the first example of the light control glass 40 includes a light control sheet 41 , an adhesive layer 42 and a glass substrate 43 . The light control sheet 41 includes a light control layer 11, a pair of transparent electrode layers 12, and a pair of transparent substrates 31, like the light control sheet 30 of the third example described above. However, the light control sheet 41 differs from the light control sheet 30 of the third example in that it does not have the colored layer 32 described above.

The adhesive layer 42 adheres the light control sheet 41 to the glass substrate 43 . The adhesive layer 42 is an example of a colored layer. The adhesive layer 42 contains an adhesive and a pigment. The adhesive contained in the adhesive layer 42 may be the adhesive that can be contained in the colored layer 32 described above. The pigment contained in the adhesive layer 42 may be a pigment that the colored layer 32 can contain.

Materials for forming the glass substrate 43 may be soda lime glass, crystal glass, borosilicate glass, or quartz glass. The glass substrate 43 may be, for example, window glass of an automobile or window glass of a building. When the glass substrate 43 is a window glass of an automobile, it is preferable that the glass substrate 43 is plate glass that satisfies the requirements specified in JIS R 3211.

Note that the light control glass 40 may have an adhesive layer instead of the adhesive layer 42 . In this case, the adhesive layer contains an adhesive and a pigment. The adhesive contained in the adhesive layer may be an adhesive that can be contained in the colored layer 32 . The pigment contained in the adhesive layer may be a pigment that can be contained in the colored layer 32 .

The light control glass 40 can be combined with each configuration of the light control sheets 10, 20, 30 of the first to third examples. The light control glass 40 may include any one of the light control sheet 10 of the first example, the light control sheet 20 of the second example, and the light control sheet 30 of the third example instead of the light control sheet 41. can. In this case, the color exhibited by the light control glass 40 is determined by cooperation between the colored layers included in the light control sheets 10 , 20 , 30 and the adhesive layer 42 .

When the light control glass 40 is combined with the light control sheets 10, 20, 30, the adhesive layer 42 may not function as a colored layer. That is, the adhesive layer 42 has the function of bonding the light control sheets 10, 20, 30 to the glass substrate 43, but does not have the function of absorbing light of a predetermined wavelength in the visible light region. good.

[Light control glass of the second example]
As shown in FIG. 5 , the light control glass 50 includes a light control sheet 51 , a pair of intermediate films 52 and a pair of glass substrates 53 . The pair of intermediate films 52 sandwich the light control sheet 51 in the thickness direction of the light control sheet 51 . The pair of glass substrates 53 sandwich the pair of intermediate films 52 in the thickness direction of the light control sheet 51 . The pair of glass substrates 53 is composed of a first glass substrate 53a and a second glass substrate 53b. An intermediate film 52 is positioned between each glass substrate 53 and the light control sheet 51 . The light control glass 50 of this example is a laminated glass in which two glass substrates 53 are adhered with an intermediate film 52 .

The light control sheet 51 has the same structure as the light control sheet 41 in the light control glass 40 of the first example. That is, the light control sheet 51 includes a light control layer, a pair of transparent electrode layers, and a pair of transparent substrates.

Each intermediate film 52 has the function of adhering one glass substrate 53 to the other glass substrate 53 . In this example, since the light control sheet 51 is positioned between the pair of glass substrates 53, each intermediate film 52 adheres one glass substrate 53 to the other glass substrate 53 via the light control sheet 51. do. Note that the intermediate film 52 used for window glass of automobiles is defined in JIS R 3211 as "an intermediate film is a material that bonds plate glass and plate glass or plastic (plate-like or film-like)". . Thus, the intermediate film 52 is a film positioned between a plate-shaped transparent member and another member and having a function of adhering the transparent member to the other member.

The intermediate film 52 is positioned between the first glass substrate 53a and the light control sheet 51 and has adhesiveness to bond the first glass substrate 53a to the light control sheet 51, or the second glass substrate. It is located between 53 b and the light control sheet 51 and has adhesiveness to adhere the second glass base material 53 b to the light control sheet 51 . The intermediate film 52 is an example of a colored layer. The intermediate film 52 may have a single-layer structure consisting only of an adhesive layer, or may have a multi-layer structure consisting of a plurality of layers. When the intermediate film 52 has a multilayer structure, the intermediate film 52 should include at least one of a sound insulating layer, an ultraviolet shielding layer, an infrared shielding layer, a visible light reflecting layer, and a light emitting layer in addition to the adhesive layer. can be done. The UV shielding layer may be a UV reflecting layer or a UV absorbing layer. The infrared shielding layer may be an infrared reflecting layer or an infrared absorbing layer. For example, the light-emitting layer can have a function of emitting light from a region irradiated with the excitation light in the light-emitting layer when the light-emitting layer is irradiated with excitation light that excites the light-emitting layer from the outside.

When the intermediate film 52 has a multi-layer structure, layers other than the adhesive layer may function as colored layers. In this case, the adhesive layer may or may not function as a colored layer. Moreover, when the adhesive layer does not have a function as a colored layer, the intermediate film 52 may contain a colored film.

The intermediate film 52 may have an adhesive layer instead of the adhesive layer. In this case, the adhesive layer contains an adhesive and a pigment. The adhesive contained in the adhesive layer may be an adhesive that can be contained in the colored layer 32 . The pigment contained in the adhesive layer may be a pigment that can be contained in the colored layer 32 .

When each intermediate film 52 has a multilayer structure, the layers included in one intermediate film 52 can be different from the layers included in the other intermediate film 52 . In this case, the functions of one intermediate film 52 and the functions of the other intermediate film 52 can be made different from each other. Note that even when the intermediate film 52 has a single-layer structure, the intermediate film 52 may be a layer containing a material exhibiting other functions in addition to the material exhibiting adhesiveness.

The light control glass 50 can be combined with each configuration of the light control sheets 10, 20, 30 of the first to third examples. The light control glass 50 may include any one of the light control sheet 10 of the first example, the light control sheet 20 of the second example, and the light control sheet 30 of the third example instead of the light control sheet 51. can. In this case, the color exhibited by the light control glass 50 is determined by cooperation between the colored layers provided in the light control sheets 10 , 20 , 30 and the intermediate film 52 .

When the light control glass 50 is combined with the light control sheets 10, 20, 30, the intermediate film 52 does not have to function as a colored layer. That is, the intermediate film 52 has the function of adhering the light control sheets 10, 20, 30 to the glass substrate 53, but does not have the function of absorbing light of a predetermined wavelength in the visible light region. good.

[Action of light control glass]
With reference to FIG. 6, the operation when the light control glass 40 of the first example is applied to the window of an automobile will be described. Below, the light control sheet 30 of the third example is adopted as the light control sheet provided in the light control glass, and the light control sheet 30 is a pair of colored layers sandwiching the light control layer in the thickness direction of the light control layer. 32 will be mainly described. Next, the operation when the colored layer 32 is positioned closer to the passenger compartment side than the light control layer, in other words, is positioned between the light control layer and the glass substrate will be described. Further, the operation when the light control glass presents a black color will be described below. 6, for convenience of illustration, the light control layer 11, the pair of transparent electrode layers 12, and the pair of transparent substrates 31 included in the light control sheet 30 are shown as one layer.

As shown in FIG. 6, in the light control glass 40, the glass substrate 43, the adhesive layer 42, and the light control sheet 30 are arranged in the order described. One surface of the glass substrate 43 is the outer surface 40O of the light control glass 40 , and one surface of the colored layer 32 is the inner surface 40I of the light control glass 40 . The outer surface 40O is part of the exterior surface of the vehicle and the inner surface 40I is part of the interior surface of the vehicle.

Since the light control glass 40 includes the pair of colored layers 32, it is possible to reduce the brightness of the black exhibited by the light control glass 40 compared to the case where the light control glass includes only one colored layer 32. Further, when the colored layer 32 has a multi-layered structure, by making the layer included in one colored layer 32 and the layer included in the other colored layer 32 different from each other, the function of one colored layer 32 and the The functions of the other colored layer 32 can be made different from each other. Thus, when the pair of colored layers 32 are provided, it is possible to impart more functions to the light control glass 40 than when the light control glass 40 is provided with one colored layer 32 .

For example, of the pair of colored layers 32, the colored layer 32 in contact with the adhesive layer 42 can be provided with an infrared reflective layer, and the colored layer 32 including the inner surface 40I can be provided with a visible light reflective layer. As a result, compared to a configuration in which the light control glass 40 does not have an infrared reflective layer and a visible light reflective layer, or a configuration in which only one of them is provided, the amount of infrared rays transmitted from the outside of the vehicle into the vehicle interior and the amount of visible light can be reduced. As a result, the temperature in the passenger compartment is prevented from becoming excessively high due to the transmission of sunlight.

The light control glass 40 may include only the colored layer 32 in contact with the adhesive layer 42 among the pair of colored layers 32 . In this case, among the pair of colored layers 32, the number of layers positioned between the viewer positioned outside the vehicle compartment and the colored layer 32 is greater than in the case where only the colored layer 32 including the inner surface 40I is provided. , the black color exhibited by the light control glass 40 is suppressed from becoming whitish. As a result, it is possible to enhance the design and luxury of the light control glass 40 for an observer positioned outside the vehicle compartment.

On the other hand, when a passenger inside the vehicle observes the outside of the vehicle through the light control glass 40, the passenger observes the outside through the light control sheet 30, so the amount of light entering the passenger's eyes increases. . Therefore, it is possible to prevent the passenger from visually recognizing the outside of the vehicle. As a result, for example, even when the passenger is wearing sunglasses, it is possible to prevent the passenger from visually recognizing the outside of the vehicle.

In the case of a conventional structure using a dichroic dye, if the curved surface is processed as in the case of application to an automobile window, for example, color unevenness due to the deviation of the dye occurs significantly. This is especially true for a type in which the outer edge of the liquid crystal layer is covered with a sealing material instead of PNLC. On the other hand, in the present embodiment, since no fluid dichroic dye is used in the layer, even if the light control sheet is applied to the curved surface, beautiful coloration without color unevenness is realized.

As described above, according to one embodiment of the light control sheet and the light control glass, the effects described below can be obtained.
(1) The light control sheet and the light control glass can exhibit a color in which the color exhibited by the light control layer 11 and the color exhibited by the colored layer are superimposed. Therefore, unevenness in the color exhibited by the light-modulating layer 11 can be suppressed compared to the case where the color exhibited by the light-modulating layer 11 and the color exhibited by the colored layer are realized only by the color exhibited by the light-modulating layer 11 .

(2) Not only in the second orientation state but also in the first orientation state, the visibility from one side to the other through the light control sheet and the visibility from the other side to the other side can be reduced.

(3) When the colored layer is the base material 13, since the base material 13 supports and colors the transparent electrode layer 12, it is necessary to add a layer different from the base material 13 for coloring or support. There is no Therefore, an increase in the thickness of the light control sheet can be suppressed, and the light control sheet can exhibit a color corresponding to the wavelength band absorbed by the base material.

(4) When the colored layer is provided as a layer separate from the pair of substrates, the degree of freedom of the material forming the colored layer can be increased compared to the case where the substrate also functions as a colored layer. .

(5) Realizes colored dimming without using any dyes including dichroic dyes. Therefore, it is possible to provide a light control sheet that is excellent in long-term reliability without fear of fading.

In addition, the embodiment described above can be implemented with the following changes.
[Orientation layer]
- Each light control sheet 10, 20, 30, 41, 51 may comprise a pair of orientation layers. When each light control sheet 10, 20, 30, 41, 51 has a pair of alignment layers, one alignment layer is positioned between the light control layer and the transparent electrode layer. In this case, the plurality of liquid crystal molecules are in the first alignment state when no drive voltage is applied to the light control layer, and the plurality of liquid crystal molecules are in the first alignment state when the drive voltage is applied to the light control layer. The plurality of liquid crystal molecules can be oriented such that the liquid crystal molecules of are in the second alignment state.

[applicable target]
- The object to which each light control sheet 10, 20, 30 and each light control glass 40, 50 are applied is not limited to an automobile, and may be, for example, a building or an apparatus. The building may be a commercial building or a residence.

[Colored layer]
- The colored layer may be a layer exhibiting colored transparency by reflecting light of a predetermined wavelength included in the visible light region.

- In the light control sheets 10, 20, 30, at least one of the first transparent electrode layer 12a and the second transparent electrode layer 12b may be a colored transparent colored layer.

10, 20, 30, 41, 51... Light control sheet 11... Light control layer 12... Transparent electrode layer 12a... First transparent electrode layer 12b... Second transparent electrode layer 13... Base material 13a... Second 1 base material 13b... second base material 21... colored layer 22, 31... transparent base material 31a... first transparent base material 31b... second transparent base material 32... colored layer 40, 50... tone Optical glass 40I inner surface 40O outer surface 42 adhesive layer 43, 53 glass base material 53a first glass base material 53b second glass base material 52 intermediate film.

Claims (6)

a polymer network partitioning a plurality of domains, and a light control layer that is a polymer network type liquid crystal layer containing a liquid crystal composition filled in the domains ;
a pair of transparent electrode layers sandwiching the light control layer in the thickness direction of the light control layer;
at least one colored transparent colored layer,
The pair of transparent electrode layers is composed of a first transparent electrode layer and a second transparent electrode layer,
The colored layer is located on at least one of the side opposite to the light control layer with respect to the first transparent electrode layer and the side opposite to the light control layer with respect to the second transparent electrode layer,
the liquid crystal composition comprises a plurality of liquid crystal molecules;
the plurality of liquid crystal molecules include a first orientation state and a second orientation state that are switched depending on whether or not a driving voltage for driving the plurality of liquid crystal molecules is applied;
The first alignment state has a higher transmittance than the second alignment state,
In the colored layer, the visible light transmittance of the light control sheet is 15% or more when the liquid crystal molecules are in the first alignment state, and the light control sheet has a visible light transmittance of 15% or more when the liquid crystal molecules are in the second alignment state. Absorbs light of a predetermined wavelength in the visible light region so that the visible light transmittance of the light sheet is 2% or less,
Munsell brightness of the colored layer is 1 or more and 5 or less
dimming sheet. The light control sheet according to claim 1 , wherein the colored layer is either a first base material supporting the first transparent electrode layer or a second base material supporting the second transparent electrode layer. The colored layer is a layer that sandwiches the first base material that supports the first transparent electrode layer together with the first transparent electrode layer in the thickness direction, or a second base material that supports the second transparent electrode layer. and the second transparent electrode layer in the thickness direction. a light control layer containing a liquid crystal composition;
A pair of transparent electrode layers sandwiching the light control layer in the thickness direction of the light control layer,
The pair of transparent electrode layers is composed of a first transparent electrode layer and a second transparent electrode layer,
at least one of the first transparent electrode layer and the second transparent electrode layer is a colored transparent colored layer ;
the liquid crystal composition comprises a plurality of liquid crystal molecules;
the plurality of liquid crystal molecules include a first orientation state and a second orientation state that are switched depending on whether or not a driving voltage for driving the plurality of liquid crystal molecules is applied;
The first alignment state has a higher transmittance than the second alignment state,
In the colored layer, the visible light transmittance of the light control sheet is 15% or more when the liquid crystal molecules are in the first alignment state, and the light control sheet has a visible light transmittance of 15% or more when the liquid crystal molecules are in the second alignment state. Absorbs light of a predetermined wavelength in the visible light region so that the visible light transmittance of the light sheet is 2% or less,
Munsell brightness of the colored layer is 1 or more and 5 or less
dimming sheet. The light control sheet according to any one of claims 1 to 4 ;
a pair of glass substrates sandwiching the light control sheet in the thickness direction of the light control sheet;
at least one interlayer;
The pair of glass substrates is composed of a first glass substrate and a second glass substrate,
The intermediate film is positioned between the first glass substrate and the light control sheet and has an adhesive property for bonding the first glass substrate to the light control sheet; and the second glass. Light control glass, which is at least one of a film having an adhesive property that is positioned between a base material and the light control sheet and bonds the second glass base material to the light control sheet. The intermediate film is colored and transparent.
The light control glass according to claim 5 .

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