JP6826482B2 - Transparent screens, bright room screens, and methods for manufacturing transparent screens. - Google Patents

Description

The present invention relates to a laminate in which reflective layers are laminated, various screens using the laminate, and a method for manufacturing the laminate.

The layer formed by fixing the cholesteric liquid crystal phase is known as a layer having a property of selectively reflecting either right-handed circularly polarized light or left-handed circularly polarized light in a specific wavelength range. Therefore, it has been developed into various uses, and as an example, various uses as a screen for projection have been proposed.

For example, Patent Document 1 includes a polarization selective reflection layer that diffusely reflects a specific polarization component as a reflection type projection screen, and the polarization selective reflection layer has at least two or more partially selective reflection layers laminated on each other. A projection screen in which the first partial selective reflection layer, which diffusely reflects light having a wavelength range indicating a color most easily absorbed by the polarization selective reflection layer, is arranged on the outermost surface of the observation side among the partial selective reflection layers. Is described.
In the projection screen described in Patent Document 1, the partially selective reflection layer has a cholesteric liquid crystal structure (a layer formed by fixing the cholesteric liquid crystal phase), and due to the structural non-uniformity (defect) of the cholesteric liquid crystal structure, It diffuses and reflects light of a specific polarization component.

Japanese Unexamined Patent Publication No. 2005-107508

A projection screen or other projection screen using a layer in which the cholesteric liquid crystal phase is fixed is required to have an enlarged viewing angle.
More specifically, when light is incident from the normal direction of the surface of the layer formed by fixing the cholesteric liquid crystal phase, either right circularly polarized light or left circularly polarized light is selectively reflected. .. At that time, if the reflection is performed not only in the normal direction but also in the oblique direction, the visibility from the oblique direction is improved. That is, when used for a screen or the like in which a layer formed by fixing a cholesteric liquid crystal phase is used as a reflective layer, the reflective layer is excellent in the characteristic of reflecting incident light in various directions (so-called diffuse reflectivity). Is required.
Further, when the layer formed by fixing the cholesteric liquid crystal phase is applied to a transparent screen or the like, high transparency is also required.

However, for example, in the case of the projection screen described in Patent Document 1, since the diffuse reflectability is obtained by introducing a defect into the cholesteric liquid crystal structure, the diffuse reflectivity and transparency do not meet the recent demand levels. For example, a transparent screen using a layer formed by fixing a conventional cholesteric liquid crystal phase is required to have further improvement in diffuse reflectance and transparency.

An object of the present invention is to solve such a problem of the prior art, and to obtain a laminated body capable of obtaining a transparent screen or the like having good diffuse reflectance and excellent transparency. It is an object of the present invention to provide a screen to be used, a transparent screen and a screen for a bright room, and a method for producing the laminate.

In order to achieve such an object, the present invention provides the following laminates, screens, transparent screens and bright room screens, and methods for manufacturing the laminates.
[1] It has a substrate and a plurality of laminated reflective layers supported by the substrate.
The reflective layer is formed by immobilizing the cholesteric liquid crystal phase, and in the cross section of the reflective layer, the bright and dark portions derived from the cholesteric liquid crystal phase have a wavy structure.
The reflective layer closest to the substrate is a laminate characterized by having a selective reflection center wavelength in a wavelength region of 400 nm or less or a wavelength region of 700 nm or more.
[2] The laminate according to [1], wherein the reflective layer closest to the substrate has a selective reflection center wavelength in a wavelength region of 700 nm or more.
[3] The laminate according to [1] or [2], wherein the selective reflection center wavelengths of the reflective layers are different from each other in all the reflective layers.
[4] The laminate according to any one of [1] to [3], wherein the direction of circular polarization reflected by the reflective layer is the same for all the reflective layers.
[5] The laminate according to any one of [1] to [4], wherein the selective reflection center wavelength of the reflective layer gradually becomes shorter toward a direction away from the substrate.
[6] The laminate according to any one of [1] to [5], wherein the number of reflective layers is 4 or less.
[7] The laminate according to any one of [1] to [6], wherein the substrate has no color and the total light transmittance is 70% or more.
[8] The selective reflection center wavelength of the reflection layer closest to the substrate is 700 to 1000 nm.
The laminate according to any one of [1] to [7], which has a reflective layer having a selective reflection center wavelength of 600 nm or more and less than 700 nm, and at least one reflective layer having a selective reflection center wavelength of 420 nm or more and less than 600 nm.
[9] The laminate according to any one of [1] to [8], wherein the reflective layer closest to the substrate has the thickest film thickness among the plurality of reflective layers.
[10] The laminate according to any one of [1] to [9], wherein the surface on which the reflective layer of the substrate is formed is a flat surface.
[11] A screen having the laminate according to any one of [1] to [10].
[12] A transparent screen having the laminate according to any one of [1] to [10].
[13] A bright room screen having the laminate according to any one of [1] to [10].
[14] A layer formed by immobilizing a cholesteric liquid crystal phase, in which the bright and dark parts derived from the cholesteric liquid crystal phase have a wavy structure and the selective reflection center wavelength is 400 nm or less or 700 nm or more. The process of forming the visible light reflective layer and
It comprises a step of applying an upper layer composition containing a liquid crystal compound and a chiral agent, orienting the liquid crystal compound to form an upper layer reflective layer in the state of a cholesteric liquid crystal phase.
After performing the step of forming the invisible light reflecting layer, the step of forming the upper reflecting layer on the invisible light reflecting layer is performed, or further, the upper reflecting layer is formed on the formed upper reflecting layer. A method for manufacturing a laminate, in which the steps are performed one or more times.
[15] The step of forming the invisible light reflecting layer is to apply the invisible light reflecting layer composition containing the liquid crystal compound and the chiral agent on the substrate and heat the applied invisible light reflecting layer composition. The method for producing a laminate according to [14], wherein the liquid crystal compound is oriented to bring it into a cholesteric liquid crystal phase, and then the invisible light reflecting layer composition is cooled or heated.
[16] In the step of forming the upper reflective layer, the cholesteric liquid crystal phase is formed by orienting the liquid crystal compound by applying the upper layer composition and then heating the upper layer composition at the time of forming at least one upper reflective layer. The method for producing a laminate according to [14] or [15], wherein the upper layer composition is then cooled or heated in the state of [14].

According to the present invention, a laminate capable of obtaining a transparent screen having high diffuse reflectance and transparency, a screen using this laminate, a transparent screen and a screen for a bright room, and a manufacturing method capable of producing this laminate Can be provided.

It is a figure which conceptually shows the cross section of the laminated body of this invention. It is a conceptual diagram for demonstrating the light reflection by a cholesteric liquid crystal phase. It is a conceptual diagram for demonstrating the light reflection by a cholesteric liquid crystal phase. It is a scanning electron micrograph of the cross section of the laminated body in the Example of this invention. It is a conceptual diagram for demonstrating the evaluation of diffuse reflectance in an Example.

Hereinafter, the present invention will be described in detail. The numerical range represented by using "~" in the present specification means a range including the numerical values before and after "~" as the lower limit value and the upper limit value.
Further, in the present specification, "(meth) acrylate" is a notation representing both acrylate and methacrylate, and "(meth) acryloyl group" is a notation representing both an acryloyl group and a methacryloyl group. "(Meta) acrylic" is a notation that represents both acrylic and methacrylic.
In the present specification, visible light is light having a wavelength visible to the human eye among electromagnetic waves, and indicates light in a wavelength range of more than 400 nm and less than 700 nm. Invisible light is light in a wavelength range of 400 nm or less or 700 nm or more. Further, although not limited to this, among visible light, light in the wavelength range of 420 nm or more and less than 500 nm is blue light (B light), and light in the wavelength range of 500 nm or more and less than 600 nm is green light (G light). Yes, the light in the wavelength range of 600 nm or more and less than 700 nm is red light (R light). Further, although not limited to this, among the invisible light, the light in the wavelength range of 200 to 400 nm is ultraviolet light, and the light in the wavelength range of 700 to 1000 nm is infrared light.

FIG. 1 conceptually shows a cross section of the laminate of the present invention. FIG. 1 is a diagram conceptually showing, for example, a state in which a cross section of the laminate of the present invention is observed with a scanning electron microscope (SEM) (the same applies to FIGS. 2 and 3 described later).
The laminate 10 shown in FIG. 1 includes a substrate 12, an infrared light reflecting layer 14 formed on one surface of the substrate 12, and a red light reflecting layer 16 laminated on the surface of the infrared light reflecting layer 14. A green light reflecting layer 18 laminated on the surface of the red light reflecting layer 16 and a blue light reflecting layer 20 laminated on the surface of the green light reflecting layer 18. In the following description, the substrate 12 side of the laminate 10 is also referred to as “bottom”, and the blue light reflecting layer 20 side is also referred to as “top”.

The infrared light reflecting layer 14, the red light reflecting layer 16, the green light reflecting layer 18, and the blue light reflecting layer 20 are all layers in which the cholesteric liquid crystal phase is fixed.
In the following description, when it is not necessary to distinguish the infrared light reflecting layer 14, the red light reflecting layer 16, the green light reflecting layer 18, and the blue light reflecting layer 20, all the reflecting layers are collectively referred to as a "reflecting layer". To tell.
As is well known, the layer formed by immobilizing a cholesteric liquid crystal has wavelength selectivity for reflection, reflects only right-handed polarized light or only left-handed polarized light in a predetermined wavelength region, and transmits other light. ..
The infrared light reflecting layer 14 has a selective reflection center wavelength in the region of infrared light (for example, 750 nm or 850 nm). The red light reflecting layer 16 has a selective reflection center wavelength in the region of red light (for example, 650 nm). The green light reflecting layer 18 has a selective reflection center wavelength in a region of green light (for example, 550 nm). Further, the blue light reflecting layer 20 has a selective reflection center wavelength in the blue light region (for example, 450 nm).

Further, as described above, the infrared light reflecting layer 14, the red light reflecting layer 16, the green light reflecting layer 18, and the blue light reflecting layer 20 are layers in which the cholesteric liquid crystal phase is fixed.
Therefore, in the cross section of the reflective layer (laminated body 10), each reflective layer has a striped pattern in which bright and dark portions are alternately laminated in the thickness direction (vertical direction in FIG. 1) due to the cholesteric liquid crystal phase. Observed.
That is, in the cross section of the infrared light reflecting layer 14, a striped pattern in which bright portions 24 and dark portions 26 are alternately laminated is observed in the thickness direction due to the cholesteric liquid crystal phase. In the cross section of the red light reflecting layer 16, a striped pattern in which bright portions 28 and dark portions 30 are alternately laminated is observed in the thickness direction due to the cholesteric liquid crystal phase. In the cross section of the green light reflecting layer 18, a striped pattern in which bright portions 32 and dark portions 34 are alternately laminated is observed in the thickness direction due to the cholesteric liquid crystal phase. Further, in the cross section of the blue light reflecting layer 20, a striped pattern in which bright portions 36 and dark portions 38 are alternately laminated is observed in the thickness direction due to the cholesteric liquid crystal phase.

Here, in the laminate 10 of the present invention, the surface on which the reflection layer is formed on the substrate 12 is a flat surface having no unevenness or wavy shape, but the infrared light reflection layer 14 and red light formed on the substrate 12 The bright and dark areas in the cross section of the reflective layer 16, the green light reflecting layer 18, and the blue light reflecting layer 20 (laminated reflective layers) have a periodic wavy structure.
That is, in the present invention, the reflective layer is a layer having a cholesteric liquid crystal structure and having a structure in which the angle formed by the spiral axis and the surface of the reflective layer changes periodically. In other words, the reflective layer has a cholesteric liquid crystal structure, and the cholesteric liquid crystal structure gives a striped pattern of bright and dark parts in a cross-sectional view of the reflective layer observed by a scanning electron microscope, and is a method of lines formed by dark parts. It is a reflective layer in which the angle between the line and the surface of the reflective layer changes periodically.

FIG. 2 conceptually shows a cross section of a layer formed by fixing a general cholesteric liquid crystal phase.
As described above, as shown in FIG. 2, in the cross section of the layer 42 in which the cholesteric liquid crystal phase is fixed arranged on the substrate 12, a striped pattern of a bright portion B and a dark portion D is usually observed. That is, in the cross section of the layer 42 in which the cholesteric liquid crystal phase is fixed, a layered structure in which bright portions B and dark portions D are alternately laminated is observed.
One bright portion B in FIG. 2 and two dark portions D arranged above and below the one bright portion B correspond to one pitch of the spiral of the cholesteric liquid crystal phase.
Generally, the striped pattern (layered structure) of the bright portion B and the dark portion D is formed so as to be parallel to the surface of the substrate 12 which is a flat surface, as shown in FIG. In such an embodiment, the layer 42 on which the cholesteric liquid crystal phase is fixed exhibits specular reflectivity. That is, when light is incident from the normal direction of the layer 42 in which the cholesteric liquid crystal phase is fixed, the light is reflected in the normal direction, but the light is hardly reflected in the diagonal direction and is inferior in diffuse reflectance (Fig. See the arrow in 2).

On the other hand, as in the layer 46 whose cross section is conceptually shown in FIG. 3, the cholesteric liquid crystal phase is fixed by using the forming surface (substrate 12) of the layer 46 on which the cholesteric liquid crystal phase is fixed as a flat surface. When the bright portion B and the dark portion D of the layer 46 have a wavy structure (undulation structure), when light is incident on the layer 46 having the wavy structure (concavo-convex structure) from the normal direction of the layer 46. , As shown in FIG. 3, since there is a region where the spiral axis of the liquid crystal compound is inclined, a part of the incident light is reflected in the oblique direction (see the arrow in FIG. 3).
That is, in the reflective layer in which the cholesteric liquid crystal phase is fixed, the reflective layer having high diffuse reflectance can be realized by having the bright portion B and the dark portion D having a wavy structure. Further, the diffuse reflectance becomes better as the unevenness of the wavy structure between the bright portion B and the dark portion D becomes larger.

As described above, each reflective layer of the laminate 10 of the present invention is a layer formed by fixing the cholesteric liquid crystal phase, and is a striped pattern of the bright portion 28 and the dark portion 30 (the bright portion 28 and the dark portion 30) of the red light reflecting layer 16. ), The bright portion 32 and the dark portion 34 of the green light reflecting layer 18 (striped pattern of the bright portion 32 and the dark portion 34), and the bright portion 36 and the dark portion 38 of the blue light reflecting layer 20 (the striped pattern of the bright portion 36 and the dark portion 38). ) Have a periodic wavy structure.
Therefore, according to the laminate 10 of the present invention, the red light reflecting layer 16, the green light reflecting layer 18, and the blue light reflecting layer 20 can preferably diffusely reflect red, green, and blue visible light. As a result, the laminated body 10 of the present invention can display an image with a wide viewing angle when used for, for example, a screen for projection.

Here, in the laminated body 10 of the present invention, the bright portion 24 and the dark portion 26 (striped pattern of the bright portion 24 and the dark portion 26) of the infrared light reflecting layer 14 formed on the surface of the substrate 12 also have a periodic wavy structure. Has. However, as described above, the infrared light reflecting layer 14 has a selective reflection center wavelength in the region of infrared light. Therefore, the infrared light reflecting layer 14 does not directly contribute to the diffuse reflection of visible light.
However, the laminate 10 of the present invention has the infrared light reflection layer 14 on the surface of the substrate 12 (as the reflection layer closest to the substrate) to enhance the transparency of the laminate 10 and the red light reflection layer. 16. It is possible to make the wavy structure of the bright part and the dark part of the green light reflecting layer 18 and the blue light reflecting layer 20 into a wavy structure having unevenness of sufficient size.
In the following description, the "wavy structure of bright and dark areas" of the reflective layer is also simply referred to as "wavy structure".

As will be described later, as an example, in the reflective layer having a wavy structure, a composition containing a liquid crystal compound and a chiral agent is applied to a surface to be formed, and the composition is heated to orient the liquid crystal compound in the cholesteric liquid crystal phase. After that, the composition can be formed by cooling the composition and fixing the cholesteric liquid crystal phase by irradiation with ultraviolet rays or the like.
The diffuse reflectance of the reflective layer increases as the unevenness of the wavy structure of the reflective layer increases.
However, in order for the wavy structure of the reflective layer to have a wavy structure having sufficiently large irregularities to obtain high diffuse reflectivity, the reflective layer needs to have a certain thickness or more.
When the reflective layer is made thicker, the light transmittance is naturally lowered and the transparency of the laminated body is lowered. That is, there is a trade-off relationship between the high light diffusivity due to the size of the unevenness of the wavy structure of the reflective layer and the transparency of the reflective layer.

Here, according to the study by the present inventors, when a reflective layer (layer formed by fixing the cholesteric liquid crystal phase) is formed on the reflective layer (layer formed by fixing the cholesteric liquid crystal phase) having a wavy structure. Following the wavy structure of the lower reflective layer (following the wavy structure of the reflective layer), the upper reflective layer also has a similar wavy structure.
Further, the larger the unevenness of the wavy structure of the lower reflection layer, the larger the unevenness of the wavy structure of the upper reflection layer. The large unevenness of the wavy structure of the reflective layer means that the height of the wave is high and the pitch of the wave is short.

The present invention has been made based on this finding, and has an infrared light reflection layer 14 having a selective reflection center wavelength in the infrared light region on the substrate 12, and red light reflection on the infrared light reflection layer 14. It has a layer 16, a green light reflecting layer 18, and a blue light reflecting layer 20.
The infrared light reflecting layer 14 reflects only infrared light and transmits all visible light. That is, even if the infrared light reflecting layer 14 is thickened, the transparency of the laminated body 10 does not decrease. Therefore, an infrared light reflecting layer 14 having a thickness capable of obtaining sufficiently large wavy unevenness is formed on the substrate 12, and a red light reflecting layer 16, a green light reflecting layer 18 and a blue light reflecting layer 14 are formed on the infrared light reflecting layer 14. By forming the layer 20, even if the red light reflecting layer 16, the green light reflecting layer 18 and the blue light reflecting layer 20 are thin, the unevenness of the wavy structure can be made sufficiently large.
Therefore, the laminate 10 of the present invention can have both high transparency and good diffuse reflectance. For example, by using it for a transparent screen, the transparency is good and the viewing angle is good. Can get a wide transparent screen.

In the laminated body 10, the reflective layer formed on the surface of the substrate 12 (closest to the substrate 12) is the infrared light reflective layer 14. The infrared light reflecting layer 14 is a reflecting layer having a selective reflection center wavelength of 700 nm or more (a layer formed by fixing a cholesteric liquid crystal phase). If the selective reflection center wavelength of the infrared light reflecting layer 14 is less than 700 nm, the transparency of the infrared light reflecting layer 14 is lowered, and the laminated body 10 having sufficient transparency cannot be obtained.
The selective reflection center wavelength of the infrared light reflecting layer 14 is preferably 700 to 1000 nm, more preferably 750 nm or more, and further preferably 800 nm or more in that transparency can be improved.

The thickness of the infrared light reflecting layer 14 is not particularly limited. The thickness of the infrared light reflecting layer 14 is preferably 1 to 20 μm, more preferably 2 to 15 μm, still more preferably 3 to 10 μm, in that the unevenness of the wavy structure of the bright portion 24 and the dark portion 26 can be increased.
Further, although there is no particular limitation, the infrared light reflecting layer 14 is preferably the thickest among the reflecting layers in that the unevenness of the wavy structure can be increased and the transparency can be improved. In this case, another reflection layer having the same thickness as the infrared light reflection layer 14 may be provided.

The laminated body 10 has a red light reflecting layer 16, a green light reflecting layer 18, and a blue light reflecting layer 20, which are layers in which the cholesteric liquid crystal phase is fixed, on the infrared light reflecting layer 14.
As described above, when the lower reflection layer has a wavy structure, the wavy structure of the upper reflection layer basically follows the wavy structure of the lower reflection layer.
Therefore, the wavy structure of the red light reflecting layer 16 follows the wavy structure of the infrared light reflecting layer 14, and the wavy structure of the green light reflecting layer 18 follows the wavy structure of the red light reflecting layer 16 and reflects blue light. The wavy structure of the layer 20 follows the wavy structure of the green light reflecting layer 18. Therefore, the irregularities of the wavy structure often match between the adjacent reflection layers.

The thicknesses of the red light reflecting layer 16, the green light reflecting layer 18, and the blue light reflecting layer 20, that is, the thicknesses of the reflecting layers other than the reflecting layer closest to the substrate 12, are also not particularly limited.
From the viewpoint of transparency, the thickness of the red light reflecting layer 16, the green light reflecting layer 18, and the blue light reflecting layer 20 is preferably 0.1 to 10 μm, more preferably 0.2 to 8 μm, and more preferably 0.5 to 6 μm. Is even more preferable.

In the laminated body 10 of the present invention, the wavy structure in the cross section of each reflective layer has a substantially uniform wave pitch, but the wave height may vary.
For example, the height of the wave may be highest in the central region in the thickness direction of the reflective layer, and gradually decrease toward the upper side (surface side) in the thickness direction and the substrate 12 side. That is, the amplitude of the wavy structure in the cross section of the reflective layer may be the largest in the central region in the thickness direction, and may gradually decrease toward the surface side and the substrate 12 side.
Alternatively, the structure may have waves having a uniform height over the entire thickness direction, such as the wavy structure of the layer 46 shown in FIG.

In the laminated body 10 of the illustrated example, the surface of each reflective layer (the upper reflective layer or the interface with air) may be flat or may have an uneven structure.
When the upper surface of the reflective layer has a concavo-convex structure, the concavo-convex structure is generally periodic (approximately periodic), and the phase of the concavo-convex is opposite to the wavy structure of the bright and dark parts of the cross section. become.
Such a reflective layer having an uneven structure on the upper surface performs at least one of selection of a chiral agent and / or an orientation control agent and selection of conditions for heat treatment or cooling treatment in the production method of the present invention described later. By doing so, it can be formed.

A reflective layer having an uneven surface has a wave height of a wavy structure in a cross section of the reflective layer larger than that of a reflective layer having a flat surface.
Therefore, a reflective layer having irregularities on the surface can obtain higher diffuse reflectivity.

In the laminated body 10 of the present invention, the wavy structure (the wavy structure of the bright part and the dark part) in the cross section of the reflective layer is the same not only in the horizontal direction of FIG. 1 but also in the cross section in the direction perpendicular to the paper surface of FIG. Wavy structure is formed. That is, the wavy structure of the reflective layer is two-dimensionally formed in the plane direction of the reflective layer, and the reflective layer has a wavy structure in the cross section in all directions.
However, the present invention is not limited to this, and the reflective layer may have a wavy structure in which continuous waves are formed so as to travel in only one direction in a cross section. However, in terms of diffuse reflectivity, it is preferable that the reflective layer has a wavy structure in all directions as described above.
The same applies to the unevenness of the upper surface of the reflective layer in this respect.

In the laminated body 10 of the present invention, the pitch of the wavy structure (distance between the tops of the waves) in the bright and dark parts of the cross section of the reflective layer is not particularly limited. The pitch of the wavy structure of the reflective layer is preferably 0.5 to 5 μm, more preferably 1 to 4 μm.
In order for the reflective layer to exhibit suitable diffuse reflectivity, it is preferable to reduce the pitch (period / frequency) of the wavy structure and increase the height of the wave (height of unevenness, that is, amplitude). However, the pitch of the wavy structure and the height of the unevenness are usually in a trade-off relationship. On the other hand, by setting the pitch of the wavy structure of the reflective layer in the above range, it is possible to form a wavy structure having a suitable balance between pitch and height, and it is possible to form a laminated body 10 having high diffuse reflectance.

As described above, the infrared light reflecting layer 14 has a selective reflection center wavelength in the region of infrared light. The red light reflecting layer 16 has a selective reflection center wavelength in the region of red light. The green light reflecting layer 18 has a selective reflection center wavelength in the region of green light. Further, the blue light reflecting layer 20 has a selective reflection center wavelength in the blue light region.
In the laminate of the present invention, the number of reflective layers excluding the infrared light reflecting layer 14 formed on the surface of the substrate 12 may be one, but is preferably two or more, or two or more. It is more preferable to have three layers. That is, the total number of reflective layers is preferably 4 or less.
Further, it is preferable that all the reflection layers other than the infrared light reflection layer 14 formed on the surface of the substrate 12 have a selective reflection center wavelength in the visible light region. In addition, in any case, it is preferable that the laminated body 10 of the present invention has a different selective reflection center wavelength in all the reflection layers. Thereby, for example, when the laminated body of the present invention is used as a projection screen or the like, a projected image can be displayed corresponding to images of various colors.

When the number of reflective layers excluding the infrared light reflecting layer 14 is three, the laminated body 10 includes the red light reflecting layer 16, the green light reflecting layer 18, and the blue light reflecting layer as shown in the illustrated example. It is preferable to have 20. That is, when the number of reflective layers excluding the infrared light reflecting layer 14 is three, it is preferable that the selective reflection center wavelength of the one reflective layer is 600 nm or more and less than 700 nm, and the one reflective layer is The selective reflection center wavelength is preferably 500 nm or more and less than 600 nm, and the selective reflection center wavelength of one layer is preferably 420 nm or more and less than 500 nm. This point is the same even when the number of reflective layers excluding the infrared light reflecting layer 14 is 4 or more.
Further, when the number of reflective layers excluding the infrared light reflecting layer 14 is two, the laminated body of the present invention is replaced with the green light reflecting layer 18 and the blue light reflecting layer 20, and green light-blue light. It is preferable to have a reflective layer. In other words, when the reflecting layer excluding the infrared light reflecting layer 14 is two layers, the laminate of the present invention preferably has a red light reflecting layer 16 and a green light-blue light reflecting layer. That is, when the number of reflective layers excluding the infrared light reflecting layer 14 is two, it is preferable that the selective reflection center wavelength of one reflective layer is 600 nm or more and less than 700 nm, and the other reflective layer. The selective reflection center wavelength is preferably 420 nm or more and less than 600 nm (for example, 470 nm).
This makes it possible to display a full-color projection image, for example, when the laminate of the present invention is used as a projection screen or the like.

The selective reflection center wavelength (center wavelength λ of selective reflection) of the reflection layer formed by fixing the cholesteric liquid crystal layer depends on the pitch P (= spiral period) of the spiral structure in the cholesteric liquid crystal phase, and the reflective layer (cholesteric liquid crystal phase). ) Follows the relationship between the average refractive index n and λ = n × P.
Here, the central wavelength λ of the selective reflection of the reflection layer means a wavelength at the center of gravity of the reflection peak of the circularly polarized reflection spectrum measured from the normal direction of the reflection layer. As can be seen from the above equation, the center wavelength of selective reflection can be adjusted by adjusting the pitch of the spiral structure. That is, by adjusting the n value and the P value, for example, in order to selectively reflect either right-handed circularly polarized light or left-handed circularly polarized light with respect to blue light, the central wavelength λ is adjusted to make an apparent selection. The central wavelength of reflection can be set to a wavelength range of 420 nm or more and less than 500 nm. The apparent center wavelength of selective reflection means the wavelength at the center of gravity of the reflection peak of the circular polarization reflection spectrum of the reflection layer measured from the observation direction during practical use (when used as a projection image display member). To do. Since the pitch of the cholesteric liquid crystal phase depends on the type of chiral auxiliary used together with the liquid crystal compound or the concentration thereof added, a desired pitch can be obtained by adjusting these.

The reflected light of the reflective layer formed by fixing the cholesteric liquid crystal phase is circularly polarized light. That is, the laminated body 10 of the present invention reflects circularly polarized light. Whether the reflected light is right-handed or left-handed depends on the twisting direction of the spiral of the cholesteric liquid crystal phase. The selective reflection of circular polarization by the cholesteric liquid crystal phase reflects the right circular polarization when the spiral twisting direction of the cholesteric liquid crystal phase is right, and the left circular polarization when the spiral twisting direction is left.
The direction of rotation of the cholesteric liquid crystal phase can be adjusted by the type of the liquid crystal compound forming the reflective layer or the type of the chiral agent added.

For the measurement method of the twist direction (sense) or pitch of the spiral, see "Introduction to Liquid Crystal Chemistry Experiment", edited by Liquid Crystal Society of Japan, Sigma Publishing, 2007, p. 46, and "Liquid Crystal Handbook", Liquid Crystal Handbook Editorial Committee, Maruzen, p. 196. The method can be used.

In the laminated body 10 of the present invention, the circularly polarized light reflected by the reflective layer is not particularly limited and may be either right-handed circularly polarized light or left-handed circularly polarized light. However, it is preferable that the laminated body 10 of the present invention reflects circularly polarized light in the same direction (turning direction) in all the reflective layers.
As a result, for example, when the laminate of the present invention is used as a screen for displaying a projected image, it is preferable that when the light source of the projector is circularly polarized light or elliptically polarized light, a difference in reflection performance depending on the color is unlikely to occur.

In addition to this, in the present invention, for example, two red light reflecting layers having the same selective reflection center wavelength are provided, one reflecting layer reflects red right circular polarization, and the other reflecting layer reflects red right circular polarization. It may be configured to reflect the red left circular polarization.

As a preferred embodiment, the laminated body 10 of the illustrated example has an infrared light reflecting layer 14 on the surface of the substrate 12, a red light reflecting layer 16 on the surface, and a green light reflecting layer 18 on the red light reflecting layer 16. , It has a blue light reflecting layer 20 on it.
That is, as a preferred embodiment of the laminated body 10, the selective reflection center wavelength of the reflective layer constituting the laminated body 10 gradually becomes shorter toward the upper side (direction away from the substrate 12).
By having such a configuration, that is, by reducing the difference in the selective reflection center wavelengths of the adjacent reflection layers, there is a large difference in structure and characteristics between the adjacent reflection layers such as the pitch of the spiral structure in the adjacent reflection layers. It is preferable in that it is possible to form a reflective layer (a layer formed by fixing the cholesteric liquid crystal phase) having few defects by preventing the occurrence of.

The laminate 10 shown in FIG. 1 has an infrared light reflecting layer 14 having a selective reflection center wavelength in the infrared light region as a reflecting layer on the surface of the substrate 12 (the reflecting layer closest to the substrate 12).
The laminate of the present invention is not limited to this, and the selective reflection center is used as the reflection layer on the surface of the substrate 12 (the reflection layer closest to the substrate 12) in a wavelength region of 400 nm or less, preferably in the wavelength region of ultraviolet light. A reflection layer having a wavelength may be provided.

By setting the selective reflection center wavelength of the reflection layer formed on the surface of the substrate 12 to 400 nm or less, even if the reflection layer is thinner than the reflection layer having a selective reflection center wavelength of 700 nm or more, the wavy structure of the reflection layer (bright portion). It is possible to form a reflective layer with large irregularities (wavy structure in the dark part).
On the other hand, as in the laminated body 10 shown in FIG. 1, by setting the selective reflection center wavelength of the reflective layer on the surface of the substrate 12 to 700 nm or more, a high-quality reflective layer with few defects can be formed, and further. By thickening the reflective layer, a wavy structure having larger irregularities can be obtained.
Therefore, when it is necessary to make the laminate thin and obtain a large diffuse reflectance, it is preferable that the selective reflection center wavelength of the reflective layer on the surface of the substrate 12 is 400 nm or less, and the laminate is particularly thin. When it is not necessary to do so, it is preferable that the selective reflection center wavelength of the reflection layer on the surface of the substrate 12 is 700 nm or more. Further, considering the diffuse reflectance and transparency comprehensively, the selective reflection center wavelength of the reflection layer on the surface of the substrate 12 is preferably 700 nm or more.

In the laminated body, when the selective reflection center wavelength of the reflection layer on the surface of the substrate 12 is 400 nm or less, the selective reflection center wavelength of the adjacent laminates is set to the same reason as that of the laminate 10 shown in FIG. It is preferable to reduce the difference. That is, when the selective reflection center wavelength of the reflection layer on the surface of the substrate 12 is 400 nm or less, it is preferable that the selective reflection center wavelength of the reflection layer gradually becomes longer from the substrate 12 upward.
Therefore, when the laminate 10 shown in FIG. 1 has the red light reflecting layer 16, the green light reflecting layer 18, and the blue light reflecting layer 20, the selective reflection center wavelength of the surface of the substrate 12 is 400 nm or less. It is preferable that the blue light reflecting layer 20 is formed on the layer, the green light reflecting layer 18 is formed on the blue light reflecting layer 20, and the red light reflecting layer 16 is formed on the green light reflecting layer 18.

As described above, the laminate 10 has an infrared light reflecting layer 14, a red light reflecting layer 16, a green light reflecting layer 18, and a blue light reflecting layer 20 formed on the substrate 12.
In the laminated body 10, the substrate 12 is a plate-like material for supporting the reflective layer (composition for forming the reflective layer).
The substrate 12 preferably has no color (that is, achromatic color) and has a total light transmittance of 70% or more. That is, the substrate 12 is preferably colorless and transparent. Further, the total light transmittance of the substrate 12 is more preferably 80% or more, further preferably 90% or more.
In the present invention, the total light transmittance may be measured according to JIS K 7361 using a commercially available measuring device such as NDH5000 or SH-7000 manufactured by Nippon Denshoku Kogyo Co., Ltd.

The material constituting the substrate 12 is not particularly limited, and for example, a cellulose-based polymer, a polycarbonate-based polymer, a polyester-based polymer, a (meth) acrylic polymer, a styrene-based polymer, a polyolefin-based polymer, a vinyl chloride-based polymer, an amide-based polymer, etc. Examples thereof include various resin materials such as imide-based polymers, sulfone-based polymers, polyether sulfone-based polymers, and polyether ether ketone-based polymers.
The substrate 12 may contain various additives such as UV (ultraviolet) absorbers, matting fine particles, plasticizers, deterioration inhibitors, and release agents. Further, the substrate 12 may have a layer such as an alignment layer on the surface.
The substrate preferably has low birefringence in the visible light region. For example, the phase difference of the substrate at a wavelength of 550 nm is preferably 50 nm or less, more preferably 20 nm or less.

The thickness of the substrate 12 is not particularly limited, but is preferably 10 to 200 μm, more preferably 20 to 100 μm from the viewpoint of thinning and handleability.
The above thickness is intended as an average thickness, and the thickness of any five points on the substrate is measured and arithmetically averaged.
As described above, in the laminated body 10 of the present invention, the reflective layer has a wavy structure, but the forming surface of the reflective layer of the substrate 12 does not have an uneven structure or a wavy structure, but is a flat surface.

As described above, the infrared light reflecting layer 14, the red light reflecting layer 16, the green light reflecting layer 18, and the blue light reflecting layer 20 (reflecting layer) are provided on the substrate 12.
The reflective layer is a layer in which the cholesteric liquid crystal phase is fixed. For such a reflective layer, as an example, a composition containing a liquid crystal compound and a chiral agent (invisible light reflective layer composition and upper layer composition) is prepared, and this composition is applied and dried, and if necessary. It can be formed by curing the composition and immobilizing the cholesteric liquid crystal phase.

(Liquid crystal compound)
The type of liquid crystal compound is not particularly limited.
In general, liquid crystal compounds can be classified into rod-shaped type (rod-shaped liquid crystal compound) and disk-shaped type (discotic liquid crystal compound, disk-shaped liquid crystal compound) according to their shape. Further, the rod-shaped type and the disk-shaped type are classified into a low molecular weight type and a high molecular weight type, respectively. A polymer generally refers to a polymer having a degree of polymerization of 100 or more (polymer physics / phase transition dynamics, by Masao Doi, p. 2, Iwanami Shoten, 1992). In the present invention, any liquid crystal compound can be used. Further, two or more kinds of liquid crystal compounds may be used in combination.

The liquid crystal compound may have a polymerizable group. The type of the polymerizable group is not particularly limited, and a functional group capable of an addition polymerization reaction is preferable, and a polymerizable ethylenically unsaturated group or a ring-polymerizable group is more preferable. More specifically, as the polymerizable group, a (meth) acryloyl group, a vinyl group, a styryl group, an allyl group, an epoxy group, or an oxetane group is preferable, and a (meth) acryloyl group is more preferable.

As the liquid crystal compound, the liquid crystal compound represented by the following formula (I) is preferable in that the diffuse reflectance of the reflective layer is more excellent.
Among them, the number of trans-1,4-cyclohexylene groups which may have a substituent represented by A is divided by m and defined as mc because the diffuse reflectance of the reflective layer is more excellent. When, a liquid crystal compound satisfying mc> 0.1 is preferable, and a liquid crystal compound satisfying 0.4 ≦ mc ≦ 0.8 is more preferable.
The mc is a number represented by the following formula.
mc = (number of trans-1,4-cyclohexylene groups may have a substituent represented by A) ÷ m

During the ceremony
A represents a phenylene group which may have a substituent or a trans-1,4-cyclohexylene group which may have a substituent, and at least one of A has a substituent. Also shows a good trans-1,4-cyclohexylene group,
L is a single bond, or -CH ₂ O-, -OCH ₂ -,-(CH ₂ ) ₂ OC (= O)-, -C (= O) O (CH ₂ ) _2- , -C (= O) O-, -OC (= O)-, -OC (= O) O-, -CH = N-N = CH-, -CH = CH-, -C≡C-, -NHC (= O) From −, −C (= O) NH−, −CH = N−, −N = CH−, −CH = CH—C (= O) O−, and −OC (= O) −CH = CH− Indicates a linking group selected from the group
m represents an integer from 3 to 12
Sp ¹ and Sp ² are independently ^one or ^two in a single bond or a linear or branched alkylene group having 1 to 20 carbon atoms and a linear or branched alkylene group having 1 to 20 carbon atoms, respectively. One or more −CH ₂₋ are −O−, −S−, −NH−, −N (CH ₃ ) −, −C (= O) −, −OC (= O) −, or −C (= O) ) Indicates a linking group selected from the group consisting of groups substituted with O−.
Q ¹ and Q ² each independently represent a hydrogen atom or a polymerizable group selected from the group consisting of groups represented by the following formulas (Q-1) to (Q-5), where Either Q ¹ or Q ² shows a polymerizable group;

A is a phenylene group which may have a substituent or a trans-1,4-cyclohexylene group which may have a substituent. In the present specification, the phenylene group is preferably a 1,4-phenylene group.
At least one of A is a trans-1,4-cyclohexylene group which may have a substituent.
The m A's may be the same or different from each other.

m represents an integer of 3 to 12, preferably an integer of 3 to 9, more preferably an integer of 3 to 7, and even more preferably an integer of 3 to 5.

The substituent which the phenylene group and the trans-1,4-cyclohexylene group in the formula (I) may have is not particularly limited, and for example, an alkyl group, a cycloalkyl group, an alkoxy group, or an alkyl ether. Examples thereof include a substituent selected from the group consisting of a group, an amide group, an amino group, a halogen atom, and a group composed of a combination of two or more of the above substituents. Further, examples of the substituent include the substituents represented by ^{-C (= O) -X 3 -Sp} 3 -Q 3 below. The phenylene group and the trans-1,4-cyclohexylene group may have 1 to 4 substituents. When having two or more substituents, the two or more substituents may be the same or different from each other.

As used herein, the alkyl group may be either linear or branched. The number of carbon atoms of the alkyl group is preferably 1 to 30, more preferably 1 to 10, and even more preferably 1 to 6. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group and a neopentyl group. Examples thereof include a 1,1-dimethylpropyl group, an n-hexyl group, an isohexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, and a dodecyl group. The description of the alkyl group in the alkoxy group is the same as the description of the alkyl group. Further, in the present specification, specific examples of the alkylene group when referred to as an alkylene group include a divalent group obtained by removing one arbitrary hydrogen atom in each of the above-mentioned examples of an alkyl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

In the present specification, the number of carbon atoms of the cycloalkyl group is preferably 3 or more, more preferably 5 or more, preferably 20 or less, more preferably 10 or less, further preferably 8 or less, and particularly preferably 6 or less. Examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group and the like.

The substituents that the phenylene group and the trans-1,4-cyclohexylene group may have include an alkyl group, an alkoxy group, and a group consisting of -C (= O) -X ^3- Sp ^3- Q ^3. Substituents selected from are preferred. Here, X ³ represents a single bond, -O-, -S-, or -N (Sp ^4- Q ⁴ )-, or a nitrogen atom forming a ring structure with Q ³ and Sp ^3. Shown. Sp ³ and Sp ⁴ are independently one or two in a single bond or a linear or branched alkylene group having 1 to 20 carbon atoms and a linear or branched alkylene group having 1 to 20 carbon atoms, respectively. One or more −CH ₂₋ are −O−, −S−, −NH−, −N (CH ₃ ) −, −C (= O) −, −OC (= O) −, or −C (= O) ) Indicates a linking group selected from the group consisting of groups substituted with O−.
In Q ³ and Q ⁴ , each of the hydrogen atom, cycloalkyl group, and cycloalkyl group has one or more -CH ₂ − -O-, -S-, -NH-, and -N (CH _3). )-, -C (= O)-, -OC (= O)-, or -C (= O) O-substituted group, or represented by formulas (Q-1) to (Q-5). Shows any polymerizable group selected from the group consisting of the groups to be.

One or more -CH ₂ − in a cycloalkyl group is −O−, −S−, −NH−, −N (CH ₃ ) −, −C (= O) −, −OC (= O) Specific examples of the group substituted with − or −C (= O) O− include a tetrahydrofuranyl group, a pyrrolidinyl group, an imidazolidinyl group, a pyrazoridinyl group, a piperidyl group, a piperazinyl group, and a morphornyl group. .. Of these, a tetrahydrofuranyl group is preferable, and a 2-tetrahydrofuranyl group is more preferable.

In formula (I), L is a single bond or −CH ₂ O−, −OCH ₂₋ , − (CH ₂ ) ₂ OC (= O) −, −C (= O) O (CH ₂ ) ₂ -, -C (= O) O-, -OC (= O)-, -OC (= O) O-, -CH = CH-C (= O) O-, and -OC (= O)- The linking group selected from the group consisting of CH = CH− is shown. L is preferably −C (= O) O− or −OC (= O) −. The m L's may be the same or different from each other.

Sp ¹ and Sp ² are independently ^one or ^two in a single bond or a linear or branched alkylene group having 1 to 20 carbon atoms and a linear or branched alkylene group having 1 to 20 carbon atoms, respectively. One or more −CH ₂₋ are −O−, −S−, −NH−, −N (CH ₃ ) −, −C (= O) −, −OC (= O) −, or −C (= O) Indicates a linking group selected from the group consisting of groups substituted with O−. Sp ¹ and Sp ² each have the number of carbon atoms to which a linking group selected from the group consisting of -O-, -OC (= O)-, and -C (= O) O- is bonded to both ends independently. Selected from the group consisting of 1 to 10 linear alkylene groups, -OC (= O)-, -C (= O) O-, -O-, and 1 to 10 carbon linear alkylene groups. It is preferably a linking group composed of one or a combination of two or more groups, and more preferably a linear alkylene group having 1 to 10 carbon atoms having —O— bonded to both ends.

Q ¹ and Q ² each independently represent a hydrogen atom or a polymerizable group selected from the group consisting of groups represented by the following formulas (Q-1) to (Q-5). However, either Q ¹ or Q ² shows a polymerizable group.

As the polymerizable group, an acryloyl group (formula (Q-1)) or a methacryloyl group (formula (Q-2)) is preferable.

Specific examples of the liquid crystal compound include a liquid crystal compound represented by the following formula (I-11), a liquid crystal compound represented by the formula (I-21), and a liquid crystal compound represented by the formula (I-31). Can be mentioned. In addition to the above, the compound represented by the formula (I) of JP2013-12631A, the compound represented by the formula (I) of JP2010-70543A, and the formula of JP-A-2008-291218. Compound represented by (I), compound represented by formula (I) of Patent No. 4725516, compound represented by general formula (II) of JP2013-087109, JP2007-176927 The compound described in paragraph [0043] of the above, the compound represented by the formula (1-1) of JP-A-2009-286885, the compound represented by the general formula (I) of WO2014 / 10325, JP-A-2016-81035. Known compounds described in the compounds represented by the formula (1) of JP-A and the compounds represented by the formulas (2-1) and (2-2) of JP-A-2016-121339 are Can be mentioned.

Liquid crystal compound represented by the formula (I-11)

In the formula, R ¹¹ represents a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, or −Z ¹² −Sp ¹² −Q ¹² .
L ¹¹ indicates a single bond, −C (= O) O−, or −O (C = O) −.
L ¹² indicates −C (= O) O−, −OC (= O) −, or −CONR ²⁻ .
R ² represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.
Z ¹¹ and Z ¹² are independently single-bonded, -O-, -NH-, -N (CH ₃ )-, -S-, -C (= O) O-, -OC (= O)-, respectively. -OC (= O) O-, ^{or, -C (= O) NR 12} - indicates,
R ¹² indicates a hydrogen atom or −Sp ¹² −Q ¹²
Sp ¹¹ and Sp ¹² are each independently a single bond, a linear or branched alkylene group having from carbon atoms 1 be replaced by Q ¹¹ 12 or carbon atoms which may be substituted with Q ^11, 1 From 12 to 12 linear or branched alkylene groups, any one or more of -CH ₂ − is -O-, -S-, -NH-, -N (Q ¹¹ )-, or -C (= O). )-Indicates the linking group obtained by substituting with-
Q ¹¹ is a hydrogen atom, a cycloalkyl group, one in the cycloalkyl group or two or more -CH ₂ - is -O -, - S -, - NH -, - N (CH 3) -, - C (= A group consisting of groups substituted with O)-, -OC (= O)-, or -C (= O) O-, or groups represented by the formulas (Q-1) to (Q-5). Indicates a polymerizable group selected from
Q ¹² represents a polymerizable group selected from the group consisting of groups represented by hydrogen atom or formula (Q-1) ~ formula (Q-5),
l ¹¹ indicates an integer from 0 to 2
m ¹¹ indicates an integer of 1 or 2 and represents
n ¹¹ indicates an integer from 1 to 3 and represents
A plurality of R ^11, a plurality of L ^11, a plurality of L ^12, a plurality of l ^11, a plurality of Z ^11, a plurality of Sp ^11, and a plurality of Q ¹¹ may each be the same or different from each other.
Further, the liquid crystal compound represented by the formula (I-11) is polymerizable as R ¹¹ selected from the group consisting of groups in which Q ¹² is represented by the formulas (Q-1) to (Q-5). It contains at least one of the base −Z ¹² −Sp ¹² −Q ¹² .
The liquid crystal compound represented by formula (I-11) is, Z ¹¹ is -C (= O) O- or ^{-C (= O) NR 12 -} , and, Q ¹¹ has the formula (Q-1) ~ It is preferably −Z ¹¹ −Sp ¹¹ −Q ¹¹ which is a polymerizable group selected from the group consisting of the groups represented by the formula (Q-5). The liquid crystal compound represented by formula (I-11) as R ^11, Z ¹² is -C (= O) O- or ^{-C (= O) NR 12 -} , and, Q ¹² has the formula (Q -1) It is preferably −Z ¹² −Sp ¹² −Q ¹² which is a polymerizable group selected from the group consisting of the groups represented by the formulas (Q-5).

The 1,4-cyclohexylene groups contained in the liquid crystal compound represented by the formula (I-11) are all trans-1,4-cyclohexylene groups.
As a preferable embodiment of the liquid crystal compound represented by the formula (I-11), L ¹¹ is a single bond, l ¹¹ is 1 (dicyclohexyl group), and Q ¹¹ is a formula (Q-1) to a formula (Q-5). ) Is a polymerizable group selected from the group consisting of the groups represented by).
As another preferred embodiment of the liquid crystal compound represented by the formula (I-11), m ¹¹ is 2, l ¹¹ is 0, and both R ¹¹ represent −Z ¹² −Sp ¹² −Q ¹² . , Q ¹² and the like are compounds which are polymerizable groups selected from the group consisting of groups represented by the formula (Q-1) ~ formula (Q-5).

Liquid crystal compound represented by the formula (I-21)

In the formula, Z ²¹ and Z ²² each independently represent a trans-1,4-cyclohexylene group which may have a substituent or a phenylene group which may have a substituent.
Each of the above substituents is 1 to 4 substituents independently selected from the group consisting of -CO-X ^21- Sp ^23- Q ²³ , an alkyl group, and an alkoxy group.
m21 represents an integer of 1 or 2, n21 represents an integer of 0 or 1,
When m21 indicates 2, n21 indicates 0,
When m21 indicates 2, the two Z ^21s may be the same or different.
At least one of Z ²¹ and Z ²² is a phenylene group which may have a substituent and is a phenylene group.
L ²¹ , L ²² , L ²³ and L ²⁴ are independently single-bonded or -CH ₂ O-, -OCH ₂ -,-(CH ₂ ) ₂ OC (= O)-, -C (= O). ) O (CH ₂ ) _2- , -C (= O) O-, -OC (= O)-, -OC (= O) O-, -CH = CH-C (= O) O-, and- Indicates a linking group selected from the group consisting of OC (= O) -CH = CH-.
X ²¹ indicates -O-, -S-, or -N (Sp ^25- Q ²⁵ )-or indicates a nitrogen atom that forms a ring structure with Q ²³ and Sp ²³ .
r ²¹ represents an integer from 1 to 4
Sp ²¹ , Sp ²² , Sp ²³ , and Sp ²⁵ are independently single-bonded or linear or branched alkylene groups with 1 to 20 carbon atoms and linear or branched alkylene groups with 1 to 20 carbon atoms, respectively. One or more -CH ₂ − in the group is −O−, −S−, −NH−, −N (CH ₃ ) −, −C (= O) −, −OC (= O) −, Alternatively, a linking group selected from the group consisting of groups substituted with −C (= O) O− is indicated.
Q ²¹ and Q ²² each independently represent any polymerizable group selected from the group consisting of the groups represented by the formulas (Q-1) to (Q-5).
In Q ²³ , one or more -CH _2- in hydrogen atom, cycloalkyl group, and cycloalkyl group are -O-, -S-, -NH-, -N (CH ₃ )-, -C (= Select from the group consisting of groups substituted with O)-, -OC (= O)-, or -C (= O) O-, and groups represented by the formulas (Q-1) to (Q-5). One of the polymerizable groups to be used, or when X ²¹ is a nitrogen atom forming a ring structure with Q ²³ and Sp ²³ , shows a single bond.
Q ²⁵ is a hydrogen atom, a cycloalkyl group, one or two or more -CH ₂ in the cycloalkyl group - is -O -, - S -, - NH -, - N (CH 3) -, - C ( It consists of a group substituted with = O)-, -OC (= O)-, or -C (= O) O-, or a group represented by the formulas (Q-1) to (Q-5). Q ²⁵ is not a hydrogen atom when it represents any polymerizable group selected from the group and Sp ²⁵ is a single bond.

The liquid crystal compound represented by the formula (I-21) preferably has a structure in which 1,4-phenylene groups and trans-1,4-cyclohexylene groups are alternately present, for example, m21 is 2. n21 is 0, and, if Z ²¹ are each optionally substituted trans-1,4-cyclohexylene group, an arylene group optionally having a substituent from Q ²¹ side, Alternatively, m21 is 1, n21 is 1, Z ²¹ is an arylene group which may have a substituent, and Z ²² is an arylene group which may have a substituent. Is preferable.

Liquid crystal compound represented by formula (I-31);

In the formula, R ³¹ and R ³² are independently selected groups from the group consisting of an alkyl group, an alkoxy group, and -C (= O) -X ^31- Sp ^33- Q ³³ .
n31 and n32 independently represent integers 0-4, respectively.
X ³¹ indicates a single bond, -O-, -S-, or -N (Sp ^34- Q ³⁴ )-or indicates a nitrogen atom forming a ring structure with Q ³³ and Sp ³³ .
Z ³¹ represents a phenylene group which may have a substituent and
Z ³² represents a trans-1,4-cyclohexylene group which may have a substituent or a phenylene group which may have a substituent.
Each of the above substituents is 1 to 4 substituents independently selected from the group consisting of an alkyl group, an alkoxy group, and -C (= O) -X ^31- Sp ^33- Q ³³ .
m31 represents an integer of 1 or 2, m32 represents an integer of 0-2,
Two Z ³¹ when m31 and m32 indicates 2, Z ³² may be the same or different and
L ³¹ and L ³² are independently single-bonded or -CH ₂ O-, -OCH ₂ -,-(CH ₂ ) ₂ OC (= O)-, -C (= O) O (CH ₂ ). _2- , -C (= O) O-, -OC (= O)-, -OC (= O) O-, -CH = CH-C (= O) O-, and -OC (= O)- Indicates a linking group selected from the group consisting of CH = CH−.
Sp ³¹ , Sp ³² , Sp ³³ and Sp ³⁴ are independently single-bonded or linear or branched alkylene groups having 1 to 20 carbon atoms and linear or branched alkylene groups having 1 to 20 carbon atoms. In one or more of -CH ₂ − are -O-, -S-, -NH-, -N (CH ₃ )-, -C (= O)-, -OC (= O)-, or Indicates a linking group selected from the group consisting of groups substituted with −C (= O) O−.
Q ³¹ and Q ³² each independently represent any polymerizable group selected from the group consisting of the groups represented by the formulas (Q-1) to (Q-5).
In Q ³³ and Q ³⁴ , one or more -CH ₂ − in hydrogen atom, cycloalkyl group, and cycloalkyl group are -O-, -S-, -NH-, and -N (CH _{3), respectively.} )-, -C (= O)-, -OC (= O)-, or -C (= O) O-substituted group, or in formulas (Q-1) to (Q-5) Representing any polymerizable group selected from the group consisting of the represented groups, Q ³³ may exhibit a single bond when forming a ring structure with X ³¹ and Sp ^33, with Sp ³⁴ In a single bond, Q ³⁴ is not a hydrogen atom.
As the liquid crystal compound represented by the formula (I-31), particularly preferable compounds include a compound in which Z ³² is a phenylene group and a compound in which m 32 is 0.

The compound represented by the formula (I) preferably has a partial structure represented by the following formula (II).
In formula (II), black circles indicate the bonding positions with other parts of formula (I). The partial structure represented by the formula (II) may be included as a part of the partial structure represented by the following formula (III) in the formula (I).

Wherein R ¹ and R ² each independently represent a hydrogen atom, an alkyl group, an alkoxy group, and is selected from the group consisting of groups represented by ^{-C (= O) -X 3 -Sp} 3 -Q 3 It is a base. Here, X ³ represents a single bond, -O-, -S-, or -N (Sp ^4- Q ⁴ )-, or a nitrogen atom forming a ring structure with Q ³ and Sp ^3. Shown. X ³ is preferably single bond or −O−. R ¹ and R ² is preferably a ^{-C (= O) -X 3 -Sp} 3 -Q 3. Further, it is preferable that R ¹ and R ² are the same as each other. The bonding position of R ¹ and R ² to each phenylene group is not particularly limited.

Sp ³ and Sp ⁴ are independently one or two in a single bond or a linear or branched alkylene group having 1 to 20 carbon atoms and a linear or branched alkylene group having 1 to 20 carbon atoms, respectively. The above -CH ₂ -is -O-, -S-, -NH-, -N (CH ₃ )-, -C (= O)-, -OC (= O)-, or -C (= O). Indicates a linking group selected from the group consisting of groups substituted with O−. As Sp ³ and Sp ⁴ , independently, a linear or branched alkylene group having 1 to 10 carbon atoms is preferable, a linear alkylene group having 1 to 5 carbon atoms is more preferable, and a direct chain having 1 to 3 carbon atoms is preferable. The alkylene group of the chain is more preferred.
In Q ³ and Q ⁴ , each of the hydrogen atom, cycloalkyl group, and cycloalkyl group has one or more -CH ₂ − -O-, -S-, -NH-, and -N (CH _3). )-, -C (= O)-, -OC (= O)-or -C (= O) O-substituted groups, or represented by formulas (Q-1) to (Q-5). Shows any polymerizable group selected from the group consisting of the groups to be.

The compound represented by the formula (I) also preferably has a structure represented by the following formula (II-2), for example.

In the formula, A ¹ and A ² independently represent a phenylene group which may have a substituent or a trans-1,4-cyclohexylene group which may have a substituent, and the above-mentioned substituents are Each is independently 1 to 4 substituents selected from the group consisting of an alkyl group, an alkoxy group, and -C (= O) -X ^3- Sp ^3- Q ³ .
L ¹ , L ² and L ³ are single bonds, or -CH ₂ O-, -OCH ₂ -,-(CH ₂ ) ₂ OC (= O)-, -C (= O) O (CH ₂ ) ₂ -, -C (= O) O-, -OC (= O)-, -OC (= O) O-, -CH = CH-C (= O) O-, and -OC (= O)- Indicates a linking group selected from the group consisting of CH = CH−.
n1 and n2 each independently represent an integer from 0 to 9, and n1 + n2 is 9 or less.
The definitions of Q ¹ , Q ² , Sp ¹ , and Sp ² are synonymous with the definitions of each group in the above formula (I). The definitions of X ³ , Sp ³ , Q ³ , R ¹ , and R ² are synonymous with the definitions of each group in the above formula (II).

Examples of the liquid crystal compound represented by the formula (I) and satisfying 0.4 ≦ mc ≦ 0.8 are described in paragraphs [0051] to [0054] of International Publication No. 2016/047648. The compounds that have been used are exemplified.

In addition, you may use 2 or more liquid crystal compounds in combination. For example, two or more liquid crystal compounds represented by the formula (I) may be used in combination.
Among them, the liquid crystal compound represented by the above formula (I), which satisfies 0.4 ≦ mc ≦ 0.8, and the liquid crystal compound represented by the formula (I), 0.1. It is preferable to use a liquid crystal compound satisfying <mc <0.3.

Examples of the liquid crystal compound represented by the formula (I) and satisfying 0.1 <mc <0.3 are described in paragraphs [0055] to [0058] of International Publication No. 2016/0447648. The compounds that have been used are exemplified.

The liquid crystal compound used in the present invention is a compound represented by the following formula (IV) described in JP-A-2014-198814, particularly one (meth) acrylate group represented by the formula (IV). A polymerizable liquid crystal compound having the above is also preferably used.

Equation (IV)
Wherein (IV), A ¹ represents an alkylene group having 2 to 18 carbon atoms, two or more CH ₂ that is not one of the CH ₂ or adjacent in the alkylene group is substituted by -O- May;
Z ¹ represents −C (= O) −, −OC (= O) − or single bond;
Z ² represents −C (= O) − or −C (= O) −CH = CH−;
R ¹ represents a hydrogen atom or a methyl group;
R ² has a hydrogen atom, a halogen atom, a linear alkyl group having 1 to 4 carbon atoms, a methoxy group, an ethoxy group, and a phenyl group, a vinyl group, a formyl group, a nitro group, and a cyano group which may have a substituent. , Acetyl group, acetoxy group, N-acetylamide group, acryloylamino group, N, N-dimethylamino group or maleimide group, methacryloylamino group, allyloxy group, allyloxycarbamoyl group, alkyl group having 1 to 4 carbon atoms. Represents a certain N-alkyloxycarbamoyl group, N- (2-methacryloyloxyethyl) carbamoyloxy group, N- (2-acryloyloxyethyl) carbamoyloxy group or a structure represented by the following formula (IV-2);
L ¹ , L ² , L ³ and L ⁴ are independently alkyl groups having 1 to 4 carbon atoms, alkoxy groups having 1 to 4 carbon atoms, alkoxycarbonyl groups having 2 to 5 carbon atoms, and 2 to 4 carbon atoms. Represents an acyl group, a halogen atom or a hydrogen atom of, and at least one of L ¹ , L ² , L ³ and L ⁴ represents a group other than a hydrogen atom.

-Z ^5- T-Sp-P formula (IV-2)
In formula (IV-2), P represents an acrylic group, a methacryl group or a hydrogen atom, Z ⁵ is a single bond, -C (= O) O-, -OC (= O)-, -C (= O). NR ¹ − (R ¹ represents a hydrogen atom or a methyl group), −NR ¹ C (= O) −, −C (= O) S−, or −SC (= O) −, where T is 1 , 4-Phenylene, Sp represents a divalent aliphatic group having 1 to 12 carbon atoms which may have a substituent, and one CH ₂ in the aliphatic group or _two or more non-adjacent groups. CH ₂ may be substituted with −O−, −S−, −OC (= O) −, −C (= O) O− or −OCOO−. ).

The compound represented by the above formula (IV) is preferably a compound represented by the following formula (V).
Equation (V)
In equation (V), n1 represents an integer of 3-6;
R ¹¹ represents a hydrogen atom or a methyl group;
Z ¹² represents -C (= O)-or -C (= O) -CH = CH-;
R ¹² is represented by a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms, a methoxy group, an ethoxy group, a phenyl group, an acryloylamino group, a methacryloylamino group, an allyloxy group, or the following formula (IV-3). Represents the structure.
-Z ^51- T-Sp-P formula (IV-3)
In formula (IV-3), P represents an acrylic or methacrylic group;
Z ⁵¹ represents -C (= O) O- or -OC (= O)-; T represents 1,4-phenylene;
Sp represents a divalent aliphatic group having 2 to 6 carbon atoms which may have a substituent. One CH ₂ or non-adjacent two or more CH ₂ in the aliphatic groups, -O -, - OC (= O) -, - C (= O) O- or -OC (= O) O It may be replaced with −.

The above n1 represents an integer of 3 to 6, and is preferably 3 or 4.
The Z ¹² represents −C (= O) − or −C (= O) −CH = CH−, and preferably −C (= O) −.
The above R ¹² is represented by a hydrogen atom, a linear alkyl group having 1 to 4 carbon atoms, a methoxy group, an ethoxy group, a phenyl group, an acryloylamino group, a methacryloylamino group, an allyloxy group, or the above formula (IV-3). It is more preferable to represent a methyl group, an ethyl group, a propyl group, a methoxy group, an ethoxy group, a phenyl group, an acryloylamino group, a methacryloylamino group, or a group represented by the above formula (IV-3). , Methyl group, ethyl group, methoxy group, ethoxy group, phenyl group, acryloylamino group, methacryloylamino group, or a structure represented by the above formula (IV-3) is more preferable.

Examples of the compound represented by the formula (IV) include the compounds described in paragraphs [0020] to [0036] of JP-A-2014-198814.

Examples of the liquid crystal compound used in the present invention include compounds represented by the following formula (VI), which are also described in JP-A-2014-198814, particularly (meth) acrylate represented by the following formula (VI). Liquid crystal compounds having no group are also preferably used.

Equation (VI)
In formula (VI), Z ³ represents −C (= O) − or −CH = CH—C (= O) −;
Z ⁴ represents −C (= O) − or −C (= O) −CH = CH−;
Each of R ³ and R ⁴ independently has a hydrogen atom, a halogen atom, a linear alkyl group having 1 to 4 carbon atoms, a methoxy group, an ethoxy group, and an aromatic ring or cyclohexyl group which may have a substituent. Carbon number of vinyl group, formyl group, nitro group, cyano group, acetyl group, acetoxy group, acryloylamino group, N, N-dimethylamino group, maleimide group, methacryloylamino group, allyloxy group, allyloxycarbamoyl group, alkyl group Is represented by an N-alkyloxycarbamoyl group in which is 1 to 4, an N- (2-methacryloyloxyethyl) carbamoyloxy group, an N- (2-acryloyloxyethyl) carbamoyloxy group, or the following formula (VI-2). Represents the structure;
L ⁵ , L ⁶ , L ⁷ and L ⁸ are independently alkyl groups having 1 to 4 carbon atoms, alkoxy groups having 1 to 4 carbon atoms, alkoxycarbonyl groups having 2 to 5 carbon atoms, and 2 to 4 carbon atoms. Represents an acyl group, a halogen atom or a hydrogen atom of, and at least one of L ⁵ , L ⁶ , L ⁷ and L ⁸ represents a group other than a hydrogen atom.

-Z ^5- T-Sp-P formula (VI-2)
In formula (VI-2), P represents an acrylic group, a methacryl group or a hydrogen atom, and Z ⁵ is −C (= O) O−, −OC (= O) −, −C (= O) NR ¹ −. (R ¹ represents a hydrogen atom or a methyl group), -NR ¹ C (= O)-, -C (= O) S-, or -SC (= O)-, and T represents 1,4-phenylene. , And Sp represents a divalent aliphatic group having 1 to 12 carbon atoms which may have a substituent. However, 2 or more CH ₂ not one CH ₂ or adjacent in the aliphatic groups, -O -, - S -, - OC (= O) -, - C (= O) O- or - It may be replaced with OC (= O) O−.

The compound represented by the above formula (VI) is preferably a compound represented by the following formula (VII).
Equation (VII)
In formula (VII), Z ¹³ represents -C (= O)-or -C (= O) -CH = CH-;
Z ¹⁴ represents −C (= O) − or −CH = CH—C (= O) −;
R ¹³ and R ¹⁴ are independently hydrogen atoms, linear alkyl groups having 1 to 4 carbon atoms, methoxy groups, ethoxy groups, phenyl groups, acryloylamino groups, methacryloylamino groups, allyloxy groups, or the above formula (IV). Represents the structure represented by -3).

The Z ¹³ represents −C (= O) − or −C (= O) −CH = CH−, and preferably −C (= O) −.
R ¹³ and R ¹⁴ are independently hydrogen atoms, linear alkyl groups having 1 to 4 carbon atoms, methoxy groups, ethoxy groups, phenyl groups, acryloylamino groups, methacryloylamino groups, allyloxy groups or the above formula (IV-). Representing the structure represented by 3), a methyl group, an ethyl group, a propyl group, a methoxy group, an ethoxy group, a phenyl group, an acryloylamino group, a methacryloylamino group, or a structure represented by the above formula (IV-3). It is preferably represented, and more preferably represents a methyl group, an ethyl group, a methoxy group, an ethoxy group, a phenyl group, an acryloylamino group, a methacryloylamino group, or a structure represented by the above formula (IV-3).

Examples of the compound represented by the formula (VI) include the compounds described in paragraphs [0042] to [0049] of JP-A-2014-198814.

As the liquid crystal compound used in the present invention, the compound represented by the following formula (VIII), which is also described in JP-A-2014-198814, particularly the two compounds represented by the following formula (VIII) ( A polymerizable liquid crystal compound having a meta) acrylate group is also preferably used.

Equation (VIII)
Wherein (VIII), A ² and A ³ each independently represents an alkylene group having 2 to 18 carbon atoms, two or more CH ₂ that is not one of the CH ₂ or adjacent in the alkylene group, - May be replaced with O-;
Z ⁵ represents −C (= O) −, −OC (= O) − or single bond;
Z ⁶ represents -C (= O)-, -C (= O) O- or a single bond;
R ⁵ and R ⁶ each independently represent a hydrogen atom or a methyl group;
L ⁹ , L ¹⁰ , L ¹¹ and L ¹² are independently alkyl groups having 1 to 4 carbon atoms, alkoxy groups having 1 to 4 carbon atoms, alkoxycarbonyl groups having 2 to 5 carbon atoms, and 2 to 4 carbon atoms. Represents an acyl group, a halogen atom or a hydrogen atom of, and at least one of L ⁹ , L ¹⁰ , L ¹¹ and L ¹² represents a group other than a hydrogen atom.

The compound represented by the above formula (VIII) is preferably a compound represented by the following formula (IX).
Equation (IX)
In formula (IX), n2 and n3 each independently represent an integer of 3-6;
R ¹⁵ and R ¹⁶ each independently represent a hydrogen atom or a methyl group.

In the formula (IX), n2 and n3 each independently represent an integer of 3 to 6, and it is preferable that n2 and n3 are 4.
In formula (IX), R ¹⁵ and R ¹⁶ each independently represent a hydrogen atom or a methyl group, and it is preferable that R ¹⁵ and R ¹⁶ represent a hydrogen atom.

Examples of the compound represented by the formula (VIII) include the compounds described in paragraphs [0056] and [0057] of JP-A-2014-198814.

These liquid crystal compounds can be produced by a known method.

(Chiral agent (chiral compound))
The composition comprises a chiral agent.
The type of chiral auxiliary is not particularly limited. The chiral agent may be liquid crystal or non-liquid crystal. The chiral agents are various known chiral agents (for example, liquid crystal device handbook, Chapter 3-4-3, TN (Twisted Nematic), STN (Super Twisted Nematic) chiral agents, page 199, Japan Society for the Promotion of Science 142. You can choose from (described in 1989, edited by the committee). Chiral agents generally contain an asymmetric carbon atom. However, an axial asymmetric compound or a surface asymmetric compound that does not contain an asymmetric carbon atom can also be used as a chiral agent. Examples of axially asymmetric or surface asymmetric compounds include binaphthyl, helicene, paracyclophane and derivatives thereof. The chiral agent may have a polymerizable group.

The content of the chiral agent in the composition is preferably 0.5 to 30% by mass with respect to the total mass of the liquid crystal compound. A smaller amount of chiral agent is preferred because it tends not to affect the liquid crystallinity. Therefore, as the chiral agent, a compound having a strong twisting force is preferable so that a desired twisting orientation of a spiral pitch can be achieved even in a small amount.
Examples of the chiral agent exhibiting such a strong twisting force include JP-A-2002-302487, JP-A-2002-80478, JP-A-2002-80851, JP-A-2002-179668, and JP-A-2002. 179670, 2002-338575, 2002-180051, 62-81354, WO2002 / 00195, 2011-241215, 2003-287623 , JP-A-2002-302487, JP-A-2002-80478, JP-A-2002-80851, and the chiral agents described in JP-A-2014-034581 and LC-756 manufactured by BASF. Can be mentioned.

(Arbitrary ingredient)
The composition may contain components other than the liquid crystal compound and the chiral agent.

(Polymerization initiator)
The composition may contain a polymerization initiator. In particular, when the liquid crystal compound has a polymerizable group, it is preferable that the composition contains a polymerization initiator.
The polymerization initiator is preferably a photopolymerization initiator capable of initiating a polymerization reaction by irradiation with ultraviolet rays. Examples of the photopolymerization initiator include α-carbonyl compounds (described in US Pat. Nos. 2,376,661 and 236,670), acidoin ether (described in US Pat. No. 2,448,828), and α-hydrogen-substituted aromatic acidoin. Compounds (described in US Pat. No. 2722512), polynuclear quinone compounds (described in US Pat. Nos. 3,043127 and 2951758), a combination of triarylimidazole dimer and p-aminophenylketone (US Pat. No. 3,549,376). (Described in the specification), aclysine and phenazine compounds (Japanese Patent Laid-Open No. 60-105667, US Pat. No. 4,239,850), oxadiazole compounds (described in US Pat. No. 4,212,970), and the like.
The content of the polymerization initiator in the composition is not particularly limited, but is preferably 0.1 to 20% by mass, more preferably 1 to 8% by mass, based on the total mass of the liquid crystal compound.

(Orientation control agent (orientation agent))
The composition may contain an orientation control agent. The inclusion of the orientation control agent in the composition allows stable or rapid formation of the cholesteric liquid crystal phase.
Examples of the orientation control agent include a fluorine-containing (meth) acrylate-based polymer, a compound represented by the general formulas (X1) to (X3) described in WO2011 / 162291, paragraph [0007] of JP2012-211306A. ] To [0029], the compounds described in paragraphs [0020] to [0031] of JP2013-47204A, the compounds described in paragraphs [0165] to [0170] of WO2016 / 909648, WO2016. / 092844, paragraphs [0077] to [0081], and general formulas (Cy201) to (Cy211) described in Japanese Patent No. 4592225 can be mentioned. It may contain two or more kinds selected from these. These compounds can reduce or substantially horizontally align the molecules of the liquid crystal compound at the air interface of the layer. In addition, although "horizontal orientation" in the present specification means that the long axis of the liquid crystal molecule and the film surface are parallel, it does not require that they are strictly parallel, and in this specification, it is referred to as a horizontal plane. It shall mean an orientation with an inclination angle of less than 20 °.
The orientation control agent may be used alone or in combination of two or more.
The content of the orientation control agent in the composition is not particularly limited, but is preferably 0.01 to 10% by mass, more preferably 0.01 to 5% by mass, and 0.01 to 0.01 to the total mass of the liquid crystal compound. 1% by mass is more preferable.

(solvent)
The composition may contain a solvent.
Examples of the solvent include water and organic solvents. Examples of the organic solvent include amides such as N and N-dimethylformamide; sulfoxides such as dimethyl sulfoxide; heterocyclic compounds such as pyridine; hydrocarbons such as benzene and hexane; alkyl halides such as chloroform and dichloromethane; acetic acid. Esters such as methyl, butyl acetate and propylene glycol monoethyl ether acetate; ketones such as acetone, methyl ethyl ketone, cyclohexanone and cyclopentanone; ethers such as tetrahydrofuran and 1,2-dimethoxyethane; 1,4-butanediol di Acetate; etc. These may be used alone or in combination of two or more.

(Other additives)
The composition is one or more kinds of antioxidants, ultraviolet absorbers, sensitizers, stabilizers, plasticizers, chain transfer agents, polymerization inhibitors, defoamers, leveling agents, thickeners. , Flame Retardants, Surfactants, Dispersants, and Other Additives such as Coloring Materials such as Dyes and Pigments.

In such a laminated body 10 of the present invention, first, an infrared light reflecting layer 14 in which the bright portion 24 and the dark portion 26 have a wavy structure in a cross section is formed on the substrate 12, and the infrared light reflecting layer 14 is topped. A red light reflecting layer 16, a green light reflecting layer 18, and a blue light reflecting layer 20 are sequentially formed by a coating method using a composition (upper layer composition) containing a liquid crystal compound and a chiral agent as described above. By doing so, it can be manufactured.

In the formation of the infrared light reflecting layer 14, first, a composition containing the liquid crystal compound and the chiral agent as described above (invisible light reflecting layer composition) is prepared, and the prepared composition is applied to the substrate 12.
The coating method is not particularly limited, and examples thereof include a wire bar coating method, an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, and a die coating method.
If necessary, the invisible light reflecting layer composition coated on the substrate 12 may be dried after coating. By carrying out the drying treatment, the solvent can be removed from the applied composition.

Next, the invisible light reflecting layer composition (composition layer (coating film)) coated on the substrate 12 is heated to orient the liquid crystal compounds in the composition to obtain a cholesteric liquid crystal phase.
The liquid crystal phase transition temperature of the invisible light reflecting layer composition is preferably in the range of 10 to 250 ° C., more preferably in the range of 10 to 150 ° C. from the viewpoint of manufacturing suitability.
As preferred heating conditions, it is preferable to heat the composition at 40 to 100 ° C. (preferably 60 to 100 ° C.) for 0.5 to 5 minutes (preferably 0.5 to 2 minutes).

After the invisible light reflective layer composition is heated to bring the liquid crystal compound into a cholesteric liquid crystal phase, the composition is cooled or cooled so as to improve the spiral inducing force of the chiral agent contained in the invisible light reflecting layer composition. It is heated to form the infrared light reflecting layer 14. That is, the coating layer is such that the spiral inducing force (HTP: Helical Twisting Power) of the chiral agent contained in the invisible light reflecting layer composition constituting the coating layer (composition layer) formed on the substrate 12 is increased. Is cooled or heat-treated.
By applying the cooling treatment and the heat treatment of the coating layer, the spiral inducing force of the chiral auxiliary is increased, the twist of the liquid crystal compound is increased, and as a result, the orientation of the cholesteric liquid crystal phase (inclination of the spiral axis) is changed. As a result, the bright portion 24 and the dark portion 26 parallel to the substrate 12 are changed, and the infrared light reflecting layer having the bright portion 24 and the dark portion 26 having a wavy structure (concave and convex structure) as shown in FIG. 1 (FIG. 3). 14 (layer of composition in cholesteric liquid crystal phase state) is formed.

When cooling the invisible light reflecting layer composition, it is preferable to cool the composition so that the temperature of the composition is lowered by 30 ° C. or more because the infrared light reflecting layer 14 is more excellent in diffuse reflectance. .. Among them, in that the above effect is more excellent, it is preferable to cool the composition so that the temperature is lowered by 40 ° C. or higher, and it is more preferable to cool the composition so that the temperature is lowered by 50 ° C. or higher. The upper limit of the reduced temperature range of the cooling treatment is not particularly limited, but is usually about 70 ° C.
In other words, the cooling treatment is intended to cool the composition so that the temperature of the composition in the cholesteric liquid crystal phase state before cooling is T-30 ° C or lower.
The cooling method is not particularly limited, and examples thereof include a method in which the substrate on which the composition is arranged is allowed to stand in an atmosphere of a predetermined temperature.

The cooling rate in the cooling process is not limited, but in order to suitably form the wavy structure of the bright portion 24 and the dark portion 26 of the cholesteric liquid crystal phase, or the unevenness of the surface of the reflective layer described later, the cooling rate is set. , It is preferable to set the speed to some extent.
Specifically, the maximum value of the cooling rate in the cooling treatment is preferably 1 ° C. or higher per second, and more preferably 2 ° C. or higher per second.

When the liquid crystal compound has a polymerizable group, the invisible light reflecting layer composition on the substrate 12 may be cured after being cooled or heat-treated to fix the cholesteric liquid crystal phase. This curing treatment may be performed at the same time as the cooling treatment or the heat treatment, or may be performed after the cooling treatment or the heat treatment is performed.
The state in which the cholesteric liquid crystal phase is "fixed" is the most typical and preferable state in which the orientation of the liquid crystal compound which is the cholesteric liquid crystal phase is maintained. It is not limited to this, and specifically, in the temperature range of 0 to 50 ° C., and more severely, -30 to 70 ° C., the layer has no fluidity, and the layer is oriented by an external field or an external force. It shall mean a state in which the fixed orientation form can be kept stable without causing a change. In the present invention, as will be described later, it is preferable to fix the orientation state of the cholesteric liquid crystal phase by a curing reaction that proceeds by irradiation with ultraviolet rays.
In the layer in which the cholesteric liquid crystal phase is fixed, it is sufficient that the optical properties of the cholesteric liquid crystal phase are retained in the layer, and it is necessary that the composition in the layer finally exhibits liquid crystallinity. Absent.

The method of curing treatment is not particularly limited, and examples thereof include photo-curing treatment and thermosetting treatment. Among them, the light irradiation treatment is preferable, and the ultraviolet irradiation treatment is more preferable.
A light source such as an ultraviolet lamp is used for ultraviolet irradiation.
The amount of ultraviolet irradiation energy is not particularly limited, but is generally preferably about 0.1 to 0.8 J / cm ² . The time of irradiation with ultraviolet rays is not particularly limited, but may be appropriately determined from the viewpoint of both sufficient strength and productivity of the obtained layer.

After forming the infrared light reflecting layer 14 having a wavy structure in this way, the red light reflecting layer 16, the green light reflecting layer 18, and the blue light reflecting layer 20 are placed on the infrared light reflecting layer 14 by a coating method. Are sequentially formed.
As a result, the red light reflecting layer 16, the green light reflecting layer 18, and the blue light reflecting layer having the wavy structure (the wavy structure of the bright part and the dark part) in the cross section follow the wavy structure of the cross section of the infrared light reflecting layer 14. 20 can be formed.

In the formation of the red light reflecting layer 16, first, as with the invisible light reflecting layer composition, an upper layer composition for forming the red light reflecting layer 16 containing the liquid crystal compound and the chiral agent as described above is prepared. ..
Next, the upper layer composition is applied onto (the surface) of the infrared light reflecting layer 14. As the coating method, the same method as that for the invisible light reflecting layer composition is used.
Next, after drying the upper layer composition as needed, the liquid crystal compounds in the composition layer formed on the infrared light reflecting layer 14 are oriented to bring the red light reflecting layer 16 into the state of the cholesteric liquid crystal phase. Form. When the liquid crystal compound has a polymerizable group, the composition may be further cured in the same manner as in the infrared light reflecting layer 14.

In the present invention, preferably, the red light reflecting layer 16 is also formed in the same manner as the infrared light reflecting layer 14. That is, the liquid crystal compound in the composition layer formed on the infrared light reflecting layer 14 is oriented by heating the upper layer composition, and after the liquid crystal compound is oriented, the upper layer composition is cooled or heat-treated. I do.
As a result, the unevenness of the wavy structure of the red light reflecting layer 16 can be increased to form the red light reflecting layer 16 having excellent diffuse reflectance.

As described above, when the lower reflective layer has a wavy structure in the cross section, the upper reflective layer also follows the wavy structure of the lower reflective layer, and the bright and dark parts in the cross section have a wavy structure. Therefore, the red light reflecting layer 16 formed on the infrared light reflecting layer 14 by the coating method also has a wavy structure in the bright portion 28 and the dark portion 30 in the cross section.

Next, an upper layer composition for forming the green light reflecting layer 18 containing the same liquid crystal compound and the chiral agent is prepared, and the green light reflecting layer 18 is formed by the same method. Further, an upper layer composition for forming the blue light reflecting layer 20 containing the same liquid crystal compound and the chiral agent is prepared, and the blue light reflecting layer 20 is formed by the same method to prepare the laminated body 10. Similar to the red light reflecting layer 16, these reflecting layers also follow the wavy structure of the lower reflecting layer, and the bright and dark parts in the cross section have a wavy structure.
When forming a larger number of reflective layers, the same film formation may be repeated according to the number of reflective layers to be formed.

Such a laminated body 10 of the present invention can be used as a screen and a half mirror for displaying a projected image. Further, by controlling the reflection band, it can also be used as a color filter or a filter for improving the color purity of the display light of the display (see, for example, Japanese Patent Application Laid-Open No. 2003-294948).
Further, the laminated body 10 can be used for various purposes such as a polarizing element, a reflective film, an antireflection film, a viewing angle compensating film, a holography, and an alignment film, which are constituent elements of an optical element.

The laminated body 10 of the present invention is particularly preferably used as a projected image display member such as a screen for displaying a projected image. Specifically, it is suitably used as a transparent screen and a screen for a bright room.
That is, by the function of the reflection layer as described above, it is possible to form a projected image by reflecting the circularly polarized light of either sense at the wavelength showing selective reflection of the projected light. The projected image may be displayed on the surface of the projected image display member and visually recognized as such, or may be a virtual image that appears above the projected image display member when viewed from the observer.

By adjusting the center wavelength of the selective reflection of each reflection layer according to the emission wavelength range of the light source used for projection and the usage mode of the projection image display member, a clear projection image can be displayed with high light utilization efficiency. Can be done. In particular, by adjusting the center wavelength of the selective reflection of the reflective layer according to the emission wavelength range of the light source used for projection, it is possible to display a clear color projected image with high light utilization efficiency.

Further, for example, the projected image display member can be made into a half mirror that can be used as a combiner of a head-up display by having a structure that is transparent to light in the visible light region. The projected image display half mirror can visually display the image projected from the projector, and when the projected image display half mirror is observed from the same side on which the image is displayed, the opposite side is displayed. You can observe the information or landscape on the side at the same time.

Hereinafter, the features of the present invention will be described in more detail with reference to Examples and Comparative Examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be appropriately changed as long as they do not deviate from the gist of the present invention. Therefore, the scope of the present invention should not be construed as limited by the specific examples shown below.

[Preparation of liquid crystal compositions 1 to 6]
The components shown in Table 1 below were mixed to prepare liquid crystal compositions 1 to 6. The amounts of each component are all parts by mass.

Rod-shaped liquid crystal compound 101

Rod-shaped liquid crystal compound 102

Rod-shaped liquid crystal compound 201

Rod-shaped liquid crystal compound 202

Chiral auxiliary

Orientation control agent (In the following formula, "33" and "67" represent the content (mol%) of each repeating unit with respect to all repeating units).

[Example 1]
As the substrate 12, a PET film (manufactured by FUJIFILM Corporation) subjected to a rubbing treatment was prepared.
The liquid crystal composition 1 as an invisible light reflecting layer composition was applied to the rubbing-treated surface of the substrate 12 at room temperature using a wire bar. The coating layer of the liquid crystal composition 1 was dried at room temperature for 10 seconds and then heated in an atmosphere of 95 ° C. for 1 minute to orient the liquid crystal compound.
Then, the coated layer is irradiated with UV light (ultraviolet light) for 8 seconds at an output of 80% using a Fusion D-bulb (lamp 90 mW / cm ² ) at 30 ° C., and an infrared light reflecting layer is applied on the substrate 12. 14 was formed. In the above procedure, the liquid crystal compound was oriented at 95 ° C., and then the liquid crystal composition was cooled to 30 ° C.
A part of the formed infrared light reflecting layer 14 is peeled off, and the film thickness of the infrared light reflecting layer 14 is measured with a shape measurement laser microscope VK-X200 (manufactured by KEYENCE) using a 10x objective lens. did. As a result, the film thickness of the infrared light reflecting layer 14 was 4 μm.

Next, the liquid crystal composition 3 was applied as an upper layer composition on the infrared light reflecting layer 14. The liquid crystal composition 3 was applied in the same manner as the invisible light reflecting layer composition. Then, the liquid crystal composition 3 was dried, heated (orientated), cooled and cured in the same manner as the infrared light reflecting layer 14, to form a red light reflecting layer 16 on the infrared light reflecting layer 14. When the film thickness was measured in the same manner, the film thickness of the red light reflecting layer 16 was 2 μm.
Hereinafter, similarly, the green light reflecting layer 18 is formed on the red light reflecting layer 16 by using the liquid crystal composition 4, and the blue light reflecting layer 20 is formed on the green light reflecting layer 18 by using the liquid crystal composition 5. It was formed to prepare a laminated body 10. The film thickness of the green light reflecting layer 18 was 1 μm, and the film thickness of the blue light reflecting layer 20 was 1 μm.
The reflected wavelength of the laminate was measured using a spectrophotometer (UV-3100PC, manufactured by Shimadzu Corporation). As a result, a peak with a selective reflection center wavelength of 750 nm derived from the liquid crystal composition 1, a peak with a selective reflection center wavelength of 650 nm derived from the liquid crystal composition 3, a peak with a selective reflection center wavelength of 550 nm derived from the liquid crystal composition 4, and further. A peak of 450 nm was observed as the selective reflection center wavelength derived from the liquid crystal composition 5.
The selective reflection center wavelengths of each reflection layer are also shown in Table 1.

When the laminate 10 was set in the polarizing microscope and each reflective layer was observed by epi-illumination so that the slow axis of the substrate 12 (PET film) coincided with the direction of the polarizer of the polarizing microscope, a diffraction grating-like structure was observed. The formation of (= undulation structure) was clearly confirmed.
Further, when the cross section of the laminated body 10 was cut by an ultramicrotome, pretreated, and the cross section was observed by an SEM (SU8030 type SEM manufactured by Hitachi High-Technologies Corporation), each reflective layer had a wavy structure in bright and dark areas. I was able to confirm that it was. FIG. 4 shows an SEM photograph of this cross section.

[Examples 2 to 5, Comparative Examples 1 to 3]
The laminate 10 is formed in the same manner as in Example 1 except that the liquid crystal composition to be used, the order in which the reflective layer is formed by the liquid crystal composition, and the coating amount (thickness of the reflective layer) of the liquid crystal composition are changed. did.
The reflection wavelength of each laminated body was measured in the same manner as in Example 1. As a result, in Examples 2 to 4, a peak having a selective reflection center wavelength of 850 nm derived from the liquid crystal composition 2 was observed instead of a peak having a selective reflection center wavelength of 750 nm derived from the liquid crystal composition 1. Further, in Example 5, a peak having a selective reflection center wavelength of 850 nm derived from the liquid crystal composition 2 was observed instead of the peak having a selective reflection center wavelength of 750 nm derived from the liquid crystal composition 1, and further, the liquid crystal composition 6 had a peak having a selective reflection center wavelength of 850 nm. A peak with a selective reflection center wavelength of 470 nm was observed.

[Evaluation]
The following evaluations were performed on the laminates 10 produced in Examples 1 to 5 and Comparative Examples 1 to 3.
<Haze and total light transmittance>
The haze and total light transmittance of the prepared laminate were measured. The haze and total light transmittance were both measured using SH-4000 manufactured by Nippon Denshoku Kogyo Co., Ltd., the haze was measured in accordance with JIS K 7136, and the total light transmittance was measured in accordance with JIS K 7361.
If the haze is 5% or less and the total light transmittance is 75% or more, it can be judged that both are good.

<Diffuse reflectivity evaluation>
The relative reflectance of each reflective layer with respect to the reference (white plate) was measured using the double beam measurement mode of GCMS-3B manufactured by Murakami Color Co., Ltd.
Specifically, as shown in FIG. 5, the incident light from the light source 50 is irradiated from the normal direction of the surface of the sample 54 (laminate or white plate), and the poles with respect to the normal direction of the surface of the sample 54. The reflected light was measured by a detector 52 arranged at a position where the angle θ was 45 °, and the relative reflectance of each reflecting layer with respect to the reference was measured.
When the relative reflectance is 5 or more, it can be judged that the diffuse reflectance is good.
The results are summarized in Table 2.

As shown in Table 2, all of the laminates of the present invention have a low haze of 5% or less, a high total light transmittance of 75% or more, and a 45 ° relative reflection amount of 5 or more. Diffuse reflectivity is also good. That is, the laminate of the present invention has both good transparency and diffuse reflectivity.
Specifically, when comparing Examples and Comparative Examples, the reflection amount of Examples 1, 2 and 5 is reduced to about 1/3 to 1/2 of that of Comparative Examples 2 and 3, but on the other hand. The haze is reduced to about 1/5, and the ratio of the amount of reflection to the haze is very high. In addition, Examples 1, 2 and 5 have a higher total light transmittance than Comparative Examples 2 and 3.
Further, comparing Examples 2 and 3 and Example 4 in which the same liquid crystal composition is used in the first to fourth layers, the selective reflection center wavelength of the reflection layer is upward from the substrate 12. However, Example 2 in which the wavelength gradually becomes shorter has better haze and total light transmittance as compared with Example 4 which does not satisfy this condition. Further, in Example 3, in which the selective reflection center wavelength of the reflective layer gradually becomes shorter from the substrate 12 upward, this condition is satisfied despite the thick film thickness of the second and subsequent layers in the visible light region. It has almost the same haze and total light transmittance as in Example 4 which does not satisfy the above conditions, and also has higher diffuse reflectance because the thickness of the second and subsequent layers in the visible light region is thick.
In addition, instead of the four reflective layers, the third layer, which is the green light reflecting layer 18, and the fourth layer, which is the blue light reflecting layer 20, are replaced with green light having a selective reflection center wavelength of 470 nm in the third layer. Example 5 having three reflective layers provided with a reflective layer having both characteristics of the reflective layer 18 and the blue light reflecting layer 20 also has the same haze and total light transmittance as the other embodiments, and diffuse reflection. Has sex.

In comparison, Comparative Examples 1 to 3 in which the selective reflection center wavelength of the reflection layer of the first layer (the surface of the substrate 12) is in the visible light region (650 nm) improves haze and total light transmittance. Therefore, it is necessary to make the first layer thin as in Comparative Example 1, and as a result, the diffuse reflectance is deteriorated. On the other hand, as in Comparative Examples 2 and 3, by thickening the reflective layer of the first layer or the subsequent layers, the diffuse reflectance is increased, but the haze and the total light transmittance are significantly decreased. That is, the laminated body of the comparative example has not been obtained with both good transparency and diffuse reflectance like the laminated body of the present invention.
From the above results, the effect of the present invention is clear.

10 Laminated body 12 Substrate 14 Infrared light reflecting layer 16 Red light reflecting layer 18 Green light reflecting layer 20 Blue light reflecting layer 24, 28, 32, 36 Bright areas 26, 30, 34, 38 Dark areas 42, 46 layers 50 Light source 52 Detector 54 samples

Claims (13)

It has a substrate having a flat surface and a plurality of laminated reflective layers formed on the flat surface of the substrate.
The reflective layer is formed by immobilizing a cholesteric liquid crystal phase, and in the cross section of the reflective layer, bright and dark portions derived from the cholesteric liquid crystal phase have a wavy structure.
A transparent screen characterized in that the reflective layer closest to the substrate has a selective reflection center wavelength in a wavelength region of 400 nm or less or 700 nm or more. The transparent screen according to claim 1, wherein the reflective layer closest to the substrate has a selective reflection center wavelength in a wavelength region of 700 nm or more. The transparent screen according to claim 2, wherein the selective reflection center wavelength of the reflection layer gradually becomes shorter toward a direction away from the substrate. The transparent screen according to any one of claims 1 to 3, wherein the selective reflection center wavelengths of the reflection layers are different from each other in all the reflection layers. The transparent screen according to any one of claims 1 to 4, wherein the direction of circular polarization reflected by the reflective layer is the same for all the reflective layers. The transparent screen according to any one of claims 1 to 5, wherein the number of reflective layers is 4 or less. The transparent screen according to any one of claims 1 to 6, wherein the substrate has no color and has a total light transmittance of 70% or more. The selective reflection center wavelength of the reflection layer closest to the substrate is 700 to 1000 nm.
The transparency according to any one of claims 1 to 7, further comprising the reflective layer having a selective reflection center wavelength of 600 nm or more and less than 700 nm, and the reflective layer having at least one selective reflection center wavelength of 420 nm or more and less than 600 nm. screen. The transparent screen according to any one of claims 1 to 8, wherein the reflective layer having the thickest film thickness among the plurality of reflective layers is closest to the substrate. It has a substrate having a flat surface and a plurality of laminated reflective layers formed on the flat surface of the substrate.
The reflective layer is formed by immobilizing a cholesteric liquid crystal phase, and in the cross section of the reflective layer, bright and dark portions derived from the cholesteric liquid crystal phase have a wavy structure.
A screen for a bright room, wherein the reflective layer closest to the substrate has a selective reflection center wavelength in a wavelength region of 400 nm or less or 700 nm or more. Invisible light which is a layer formed by immobilizing a cholesteric liquid crystal phase, in which bright and dark parts derived from the cholesteric liquid crystal phase have a wavy structure and a selective reflection center wavelength is 400 nm or less or 700 nm or more. The process of forming the reflective layer and
It comprises a step of applying an upper layer composition containing a liquid crystal compound and a chiral agent, orienting the liquid crystal compound to form an upper layer reflective layer in a state of a cholesteric liquid crystal phase.
After performing the step of forming the invisible light reflecting layer on the flat surface of the substrate having a flat surface, the step of forming the upper layer reflecting layer on the invisible light reflecting layer was performed, or further formed. A method for manufacturing a transparent screen, in which the step of forming the upper reflective layer on the upper reflective layer is performed one or more times. The step of forming the invisible light reflecting layer is
A non-visible light reflecting layer composition containing a liquid crystal compound and a chiral agent is applied onto a substrate, and the coated invisible light reflecting layer composition is heated to orient the liquid crystal compound to obtain a state of a cholesteric liquid crystal phase. The method for producing a transparent screen according to claim 11 , wherein the treatment is performed, and then the invisible light reflecting layer composition is cooled or heated. In the step of forming the upper layer reflective layer, the liquid crystal compound is oriented and cholesteric by applying the upper layer composition and then heating the upper layer composition at the time of forming at least one layer of the upper layer reflective layer. The method for producing a transparent screen according to claim 11 or 12 , wherein the upper layer composition is brought into a liquid crystal phase state and then subjected to a treatment of cooling or heating the upper layer composition.