Decorative film, display device, and automobile interior finishing

Abstract

The present invention addresses the first problem of providing a decorative film having a cholesteric liquid crystal layer capable of reproducing colors in the region bounded by x = 0.26-0.40 and y = 0.28-0.40 in an xy chromaticity diagram of the CIE1931 color space without any grainy touch. The present invention also addresses the second problem of providing a display device and an automobile interior finishing comprising the decorative film.　The decorative film has a base material and a cholesteric liquid crystal layer. The cholesteric liquid crystal layer has an in-plane region in which the pitch of the liquid crystal compound helical structure is different.

Description

Decorative films, display devices, and interior trims for automobiles

[0001] The present invention relates to a decorative film, a display device, and an interior trim for an automobile.

[0002] It is known that a cholesteric liquid crystal phase has a property of selectively reflecting either right-handed circularly polarized light or left-handed circularly polarized light in a specific wavelength band (selective reflection property). Cholesteric liquid crystal layers obtained by fixing a cholesteric liquid crystal phase have been applied in various fields, such as color filters, due to their selective reflection property. For example, Patent Document 1 discloses an application as a light-reflective RGB-patterned cholesteric color filter.

[0003] Recently, decorative films have been used to decorate the surfaces of home appliances, office equipment, automobile parts, etc. As such decorative films, the use of decorative films having a cholesteric liquid crystal layer has been considered, and there is a demand for the reproduction of various colors.

[0004] Special Publication No. 2004-538515

[0005] On the other hand, the reflection spectrum of a single cholesteric liquid crystal layer in which the pitch of the helical structure of the liquid crystal compound (hereinafter also referred to as "helical pitch") is uniform is close to a monochromatic spectrum because the reflection band is relatively narrow, and the reproducible colors are limited to the colors on and near the periphery of the xy chromaticity diagram defined by the CIE (International Commission on Illumination) (hereinafter also referred to as "xy chromaticity diagram of the CIE 1931 color space").

[0006] In contrast, if a reflection spectrum having a broad reflection band with a half-width of 150 nm or more in the visible light region can be formed by mixing a plurality of monochromatic spectra, it becomes possible to reproduce colors closer to the center of the xy chromaticity diagram of the CIE 1931 color space. The present inventors have now discovered that there is room for further investigation into a method for reproducing, without producing a grainy appearance, colors near the center of the xy chromaticity diagram of the CIE 1931 color space, particularly colors on and near the curve known as the "blackbody locus," which includes white (specifically, colors in the region surrounded by x = 0.26 to 0.40 and y = 0.28 to 0.40 (colors such as gray to pale orange)).

[0007] Therefore, an object of the present invention is to provide a decorative film having a cholesteric liquid crystal layer that can reproduce the colors in the region surrounded by x = 0.26 to 0.40 and y = 0.28 to 0.40 in the xy chromaticity diagram of the CIE 1931 color space without producing a grainy appearance. Another object of the present invention is to provide a display device and an automobile interior that include the decorative film.

[0008] As a result of extensive research into solving the above problems, the present inventors have found that the above problems can be solved by the following configuration, and have completed the present invention.

[0009] [1] A decorative film having a substrate and a cholesteric liquid crystal layer, wherein the cholesteric liquid crystal layer has regions in its plane where the pitch of the helical structure of the liquid crystal compound varies, the magnitude of the pitch changes continuously in one direction in the plane, and maximum and minimum values ​​of the pitch appear alternately, the maximum value being in the range of 350 to 600 nm, and the minimum value being in the range of 150 to 300 nm, the magnitude of the pitch changes continuously in a direction perpendicular to the one direction, and maximum and minimum values ​​of the pitch appear alternately, the maximum value being in the range of 350 to 600 nm, and the minimum value being in the range of 150 to 300 nm, the distance between positions showing adjacent maximum values ​​in the one direction is 100 to 300 μm, and the distance between positions showing adjacent maximum values ​​in the direction perpendicular to the one direction is 100 to 300 μm, A decorative film, wherein: when a position showing the maximum value of the pitch is defined as a first position and a position showing the minimum value of the pitch adjacent to the first position in the one direction is defined as a second position, a difference between the maximum value of the pitch at the first position and the minimum value of the pitch at the second position is 100 nm or more; when a position showing the maximum value of the pitch is defined as a first position and a position showing the minimum value of the pitch adjacent to the first position in a direction perpendicular to the one direction is defined as a third position, a difference between the maximum value of the pitch at the first position and the minimum value of the pitch at the third position is 100 nm or more. [2] The decorative film according to [1], wherein the half width in a reflection wavelength band of the cholesteric liquid crystal layer is 150 nm or more. [3] A display device comprising a display element and the decorative film according to [1] or [2], arranged on one surface of the display element. [4] The display device according to [3], wherein light emitted from the display element is linearly polarized light. [5] The display device according to [3] or [4], wherein the display element is a liquid crystal display device or an electroluminescence display device. [6] An automobile interior, comprising the decorative film according to [1] or [2]. [7] An automobile interior, comprising the display device according to [3] or [4].

[0010] According to the present invention, a decorative film having a cholesteric liquid crystal layer can be provided that can reproduce the color of the region surrounded by x = 0.26 to 0.40 and y = 0.28 to 0.40 in the xy chromaticity diagram of the CIE 1931 color space without producing a grainy appearance. Furthermore, according to the present invention, a display device and an automobile interior trim that include the decorative film can be provided.

[0011] FIG. 1 is a schematic diagram showing an example of an embodiment of a decorative film. FIG. 2 is a schematic explanatory diagram for explaining regions in the plane of a cholesteric liquid crystal layer 12 where the pitch of the helical structure of a liquid crystal compound is different. FIG. 3 is a schematic diagram showing changes in the magnitude of the helical pitch of a liquid crystal compound in an H-H' cross section along the X direction of the cholesteric liquid crystal layer 12. FIG. 4 is a schematic diagram showing changes in the magnitude of the helical pitch of a liquid crystal compound in a V-V' cross section along the Y direction of the cholesteric liquid crystal layer 12. FIG. 5 is a schematic diagram showing the halftone dot pattern of an AM screen mask used in the Examples section. FIG. 6 is a schematic diagram showing the halftone dot arrangement method of the mask used in Comparative Example 2.

[0012] The present invention will be described in detail below. The following description of the constituent elements may be based on representative embodiments of the present invention, but the present invention is not limited to such embodiments. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. Furthermore, in this specification, the liquid crystal composition and liquid crystal compound conceptually include those that no longer exhibit liquid crystallinity due to curing or the like.

[0013] In this specification, "parallel" and "orthogonal" do not mean "parallel" and "orthogonal" in the strict sense, but rather mean a range of parallel ±5° and orthogonal ±5°, respectively. In this specification, "(meth)acrylate" is used to mean "either one or both of acrylate and methacrylate." In addition, "(meth)acryloyl" is used to mean "either one or both of acryloyl and methacryloyl."

[0014] In the present invention, the selective reflection central wavelength and half-width in the selective reflection wavelength band of the cholesteric liquid crystal layer of the decorative film are determined by the following method. First, the integrated reflectance at wavelength λ of the cholesteric liquid crystal layer of the decorative film is measured using a spectrophotometer (JASCO Corporation, V-550) equipped with a large integrating sphere device (JASCO Corporation, ILV-471). When the integrated reflectance is measured by the above-mentioned method, a spectral waveform of the integrated reflectance is obtained that is a mountain-shaped (convex upward) curve with wavelength as the horizontal axis. The average reflectance (arithmetic mean) of the maximum and minimum values ​​of the integrated reflectance is then determined, and of the two wavelengths at the two intersections between the spectral waveform and the average reflectance, the value of the shorter wavelength wavelength is λα (nm) and the value of the longer wavelength wavelength is λβ (nm), and the value is calculated using the following formula: Selective reflection central wavelength = (λα + λβ) / 2 Half-width = (λβ - λα)

[0015] In this specification, "visible light" refers to light with a wavelength of 400 to 700 nm, and "ultraviolet light" refers to light with a wavelength of 10 nm or more and less than 400 nm.

[0016] [Decorative film] The decorative film of the present invention is a decorative film having a substrate and a cholesteric liquid crystal layer, wherein the cholesteric liquid crystal layer has regions in its plane where the pitch of the helical structure of the liquid crystal compound is different, the magnitude of the pitch changes continuously in one in-plane direction (hereinafter also referred to as "direction X"), and maximum and minimum values ​​of the pitch appear alternately, the maximum value being in the range of 350 to 600 nm, and the minimum value being in the range of 150 to 300 nm, the magnitude of the pitch changes continuously in a direction (hereinafter also referred to as "direction Y") perpendicular to the one direction (direction X), and maximum and minimum values ​​of the pitch appear alternately, the maximum value being in the range of 350 to 600 nm, and the minimum value being in the range of 150 to 300 nm, the distance between positions showing adjacent maximum values ​​in the one direction (direction X) is 100 to 300 μm, the distance between adjacent positions showing the maximum value in a direction (direction Y) perpendicular to the one direction is 100 to 300 μm; when the position showing the maximum value of the pitch is defined as a first position and the position showing the minimum value of the pitch adjacent to the first position in the one direction (direction X) is defined as a second position, the difference between the maximum value of the pitch at the first position and the minimum value of the pitch at the second position is 100 nm or more; when the position showing the maximum value of the pitch is defined as the first position and the position showing the minimum value of the pitch adjacent to the first position in the direction (direction Y) perpendicular to the one direction is defined as a third position, the difference between the maximum value of the pitch at the first position and the minimum value of the pitch at the third position is 100 nm or more.

[0017] The cholesteric liquid crystal layer of the decorative film can reproduce the colors in the region surrounded by x=0.26 to 0.40 and y=0.28 to 0.40 in the xy chromaticity diagram of the CIE 1931 color space without producing a grainy appearance.

[0018] The effects of the cholesteric liquid crystal layer in the decorative film of the present invention are presumed to be as follows: In the cholesteric liquid crystal layer of the decorative film, the helical pitch of the liquid crystal compound changes continuously in the in-plane X and Y directions, and maximum and minimum values ​​of the pitch alternate (where the maximum value is in the range of 350 to 600 nm and the minimum value is in the range of 150 to 300 nm), with the difference between adjacent maximum and minimum values ​​being 100 nm or greater. As a result, a reflection spectrum can be formed with a broad reflection band with a half-width of 150 nm or greater in the visible light range, making it possible to reproduce colors in the region bounded by x = 0.26 to 0.40 and y = 0.28 to 0.40 on the xy chromaticity diagram of the CIE 1931 color space. The cholesteric liquid crystal layer selectively reflects incident light and exhibits a hue corresponding to the wavelength of the reflected light. By varying the helical pitch of the liquid crystal compound, the hue of the reflected light selectively reflected by the cholesteric liquid crystal layer can be adjusted. For example, when the average refractive index (wavelength 589.3 nm) of the liquid crystal compound is approximately 1.5, the reflected light from a helical structure with a maximum pitch value will be red, while the reflected light from a helical structure with a minimum pitch value will be blue. Furthermore, the cholesteric liquid crystal layer of the decorative film has a distance between adjacent positions showing maximum pitch values ​​of 100 to 300 μm in each of the in-plane X and Y directions. With this configuration, when the reflected light from the cholesteric liquid crystal layer is viewed, the human eye cannot separate the colors (in other words, it is viewed as a single color), so the graininess (roughness of the image) is less noticeable.

[0019] [First embodiment] Fig. 1 is a schematic diagram showing one example (first embodiment) of an embodiment of the decorative film of the present invention. The decorative film 1 shown in Fig. 1 has a substrate 10 and a cholesteric liquid crystal layer 12 on the surface of the substrate 10. As will be described later, the cholesteric liquid crystal layer 12 has regions in its plane where the pitch of the helical structure (helical pitch) of the liquid crystal compound is different. The decorative film 1 may further have a base layer (not shown) between the substrate 10 and the cholesteric liquid crystal layer 12.

[0020] The thickness of the decorative film 1 is not particularly limited, but is preferably 30 to 1,500 μm, more preferably 50 to 1,000 μm, and even more preferably 90 to 500 μm.

[0021] <Substrate 10> The substrate 10 is a member that supports the cholesteric liquid crystal layer 12. There are no particular limitations on the substrate 10, and known films can be used, with a resin film being preferred. Examples of resins that can be used to form the resin film include polyesters such as polyethylene terephthalate (PET), polycarbonate (PC), acrylic resins, epoxy resins, polyurethanes, cycloolefin resins, polyamides, polyolefins, cellulose derivatives, and silicones. The substrate 10 may be either a single layer or a multilayer.

[0022] The substrate 10 is preferably colorless and transparent. The term "colorless and transparent" means that the substrate 10 has substantially no absorption in the visible light region. The average transmittance of the substrate 10 in the wavelength region of 380 to 780 nm is preferably 80% or more, and more preferably 90% or more.

[0023] The substrate 10 may be a releasable substrate that can be peeled from the cholesteric liquid crystal layer 12 or an optionally disposed underlayer. Examples of the releasable substrate 10 include resin films formed from resins such as cellulose derivatives, cycloolefin resins, acrylic resins, and polyethylene terephthalate. The releasable substrate may also be a non-releasable substrate having a release layer formed on its surface, or a surface-treated non-releasable substrate. The releasable substrate 10 is peeled from the decorative film 1 after being attached to a component of an image display device for manufacturing the image display device, or after being attached to a component of an automobile interior.

[0024] The thickness of the substrate 10 is not particularly limited and can be set appropriately depending on the material constituting the substrate. The lower limit of the thickness of the substrate 10 is typically preferably 20 μm or more, more preferably 40 μm or more. Furthermore, when the substrate 10 is a peelable substrate, the lower limit of its thickness is preferably 35 μm or more, more preferably 50 μm or more. Note that by setting the thickness of the substrate 10, which serves as the substrate when forming the cholesteric liquid crystal layer 12 or an optionally disposed underlayer, to 20 μm or more, and particularly setting the thickness of the peelable substrate 10 to 50 μm or more, a more uniform layer is more likely to be obtained. The upper limit of the thickness of the substrate 10 is typically preferably 1000 μm or less, more preferably 500 μm or less, and even more preferably 300 μm or less.

[0025] <Underlayer> As described above, the decorative film 1 may optionally have an underlayer between the substrate 10 and the cholesteric liquid crystal layer 12. The underlayer may be any layer having a function according to the purpose, and examples thereof include an alignment film for forming the cholesteric liquid crystal layer 12, a protective layer that prevents damage to the substrate 10 by a solvent when the cholesteric liquid crystal layer 12 is formed, and a layer that reduces the difference in surface energy between the surface of the substrate 10 and the material forming the cholesteric liquid crystal layer 12. Furthermore, when the substrate 10 is peelable, the underlayer may function as a protective layer that protects the cholesteric liquid crystal layer 12 after the decorative film 1 is attached to another member and the substrate 10 is peeled off.

[0026] The underlayer is preferably a resin layer. The resin constituting the underlayer is not particularly limited, but examples thereof include polyacrylate resin, polymethacrylate resin, polyvinyl alcohol resin, polyolefin resin, polycarbonate resin, polyurethane resin, polystyrene resin, polyimide resin, epoxy resin, polyester resin, and polyether resin. The underlayer may be either a single layer or a multilayer. The thickness of the underlayer is not particularly limited, and is, for example, preferably 0.01 to 8.0 μm, more preferably 0.2 to 3.0 μm, and even more preferably 0.5 to 2.0 μm.

[0027] <Cholesteric Liquid Crystal Layer 12> The cholesteric liquid crystal layer 12 is a layer in which liquid crystal compounds are oriented to form a cholesteric liquid crystal phase. Alternatively, the cholesteric liquid crystal layer may be a layer formed by fixing the cholesteric liquid crystal phase. Here, the "fixed" cholesteric liquid crystal phase state refers to a state in which the orientation of the liquid crystal compounds in the cholesteric liquid crystal phase is maintained, which is the most typical and preferred embodiment. However, this is not limited thereto. Specifically, it refers to a state in which the layer lacks fluidity and can stably maintain the fixed orientation state without any change in the orientation state due to external fields or external forces, typically within a temperature range of 0 to 50°C, or, under more severe conditions, within a temperature range of −30 to 70°C. As described below, the cholesteric liquid crystal layer 12 is preferably a layer in which the orientation state of the cholesteric liquid crystal phase is fixed by a photocuring reaction (preferably a curing reaction that proceeds by ultraviolet irradiation).

[0028] Cholesteric liquid crystal phases are known to exhibit selective reflectivity at specific wavelengths. In a typical cholesteric liquid crystal phase, the central wavelength of selective reflection (selective reflection central wavelength) λ depends on the helical pitch P of the cholesteric liquid crystal phase and follows the relationship λ = n × P with the average refractive index n of the cholesteric liquid crystal phase. Therefore, the selective reflection central wavelength can be adjusted by adjusting this helical pitch. The larger (longer) the helical pitch, the longer the selective reflection central wavelength of the cholesteric liquid crystal phase. Note that the helical pitch is one pitch (helical period) of the helical structure of the cholesteric liquid crystal phase, in other words, one helical turn, i.e., the length of the helical axis direction in which the director of the liquid crystal compound constituting the cholesteric liquid crystal phase rotates 360°. For example, in the case of a rod-shaped liquid crystal, the director is the long axis.

[0029] The helical pitch of a cholesteric liquid crystal phase depends on the type and concentration of the chiral agent used together with the liquid crystal compound when forming the cholesteric liquid crystal layer. Therefore, the desired helical pitch can be obtained by adjusting these factors. Details on adjusting the pitch are provided in Fujifilm Research Report No. 50 (2005), pp. 60-63. Methods for measuring the sense and pitch of the helical pitch can be found in "Introduction to Liquid Crystal Chemistry Experiments," edited by the Japanese Liquid Crystal Society, published by Sigma Publishing in 2007, p. 46, and "Liquid Crystal Handbook," published by the Liquid Crystal Handbook Editorial Committee, Maruzen, p. 196.

[0030] Furthermore, cholesteric liquid crystal phases exhibit selective reflection for either left- or right-handed circularly polarized light at a specific wavelength. Whether the reflected light is right-handed or left-handed circularly polarized light depends on the twist direction (sense) of the helix of the cholesteric liquid crystal phase. The selective reflection of circularly polarized light by a cholesteric liquid crystal phase reflects right-handed circularly polarized light when the helix twist direction of the cholesteric liquid crystal layer is right-handed, and reflects left-handed circularly polarized light when the helix twist direction is left-handed. The direction of rotation of the cholesteric liquid crystal phase can be adjusted by the type of liquid crystal compound forming the cholesteric liquid crystal layer and / or the type of chiral agent added.

[0031] The cholesteric liquid crystal layer 12 is a layer in which the liquid crystal compound is oriented to form a cholesteric liquid crystal phase, and as shown in Fig. 2 , it has regions 14 in its plane in which the helical pitch of the liquid crystal compound varies. In the regions 14, positions A (hereinafter also referred to as "maximum positions A") where the helical pitch of the liquid crystal compound is maximum and positions B (hereinafter also referred to as "minimum positions B") where the helical pitch of the liquid crystal compound is minimum are alternately arranged at substantially equal intervals and in a substantially regular pattern in both the row direction (X direction) and column direction (Y direction) in the plane (note that the Y direction is a direction perpendicular to the X direction). That is, in the regions 14, the magnitude of the helical pitch of the liquid crystal compound continuously changes in one in-plane direction, and multiple rows in which the maximum and minimum values ​​of the helical pitch of the liquid crystal compound alternate are arranged in a direction perpendicular to the one in-plane direction. In the perpendicular direction, the magnitude of the helical pitch of the liquid crystal compound also continuously changes, and the maximum and minimum values ​​of the helical pitch of the liquid crystal compound alternate.

[0032] 3 is a schematic diagram showing the change in the magnitude of the helical pitch of the liquid crystal compound in the HH' cross section along the X direction of the cholesteric liquid crystal layer 12. In FIG. 3, the region surrounded by the dotted line in FIG. 2 (maximum position A （１，１） , minimum position B （１，１） , maximum position A （１，２） Only the cross-sectional area corresponding to the region containing the

[0033] The upper diagram of Fig. 3 is a schematic diagram showing the liquid crystal compound LC oriented in a cholesteric liquid crystal manner along a helical axis extending in the thickness direction. （１，１） and minimum position B （１，１） When comparing the minimum position B （１，１） In the upper diagram of FIG. 3, the number of turns of the liquid crystal compound LC is larger, and the helical pitch is shorter. （１，１） and minimum position B （１，１） and the maximum position A （１，２） and minimum position B （１，１） The helical pitch of the helical structure formed by the liquid crystal compound LC is at the maximum position A （１，１） and maximum position A （１，２） and the minimum position B （１，１） The helical pitch of the helical groove 10 has an intermediate region, which is larger than the helical pitch of the helical groove 10 in the helical groove 10 .

[0034] The lower diagram of Fig. 3 is a schematic diagram showing the relationship between the magnitude and position of the helical pitch of the cholesteric liquid crystal layer 12 shown in the upper diagram of Fig. 3. The vertical axis represents the magnitude of the helical pitch, and the horizontal axis represents the position in the X direction in the plane. As shown in the lower diagram of Fig. 3, the cholesteric liquid crystal layer 12 has a maximum position A along the X direction in the plane. （１，１） From maximum position A （１，２） The magnitude of the helical pitch of the liquid crystal compound LC changes continuously toward the helical pitch of the liquid crystal compound LC. The rate of change of the helical pitch is, for example, preferably 250 to 3,000 nm / mm, and more preferably 500 to 2,500 nm / mm, in terms of achieving a better effect of the present invention.

[0035] The magnitude of the helical pitch can be confirmed by observation with a scanning electron microscope (SEM). When an H-H' cross section of the cholesteric liquid crystal layer 12 along the X direction is observed with an SEM, a striped pattern is observed in which lines of bright areas (bright lines) and lines of dark areas (dark lines) derived from the cholesteric liquid crystal phase are alternately arranged in the thickness direction. The observed striped pattern has a periodic wave structure with amplitude in the thickness direction of the cholesteric liquid crystal layer 12, and the spacing between the bright lines is large at a location corresponding to the maximum position A and small at a location corresponding to the minimum position B. The magnitude of the helical pitch (the size of one turn of the spiral) corresponds to the value obtained by doubling the distance from the center position of any bright line to the center position of the adjacent bright line in the striped pattern observed with an SEM.

[0036] 4 is a schematic diagram showing the change in the magnitude of the helical pitch of the liquid crystal compound in the VV' cross section along the Y direction of the cholesteric liquid crystal layer 12. In FIG. 4, the region surrounded by the dotted line in FIG. 2 (maximum position A （１，１） , minimum position B （２，１） , maximum position A （３，１） Only the cross-sectional area corresponding to the region containing the

[0037] The upper diagram of Fig. 4 is a schematic diagram showing the liquid crystal compound LC oriented in a cholesteric liquid crystal manner along a helical axis extending in the thickness direction. （１，１） and minimum position B （２，１） When comparing the minimum position B （２，１） In the upper diagram of FIG. 4, the number of turns of the liquid crystal compound LC is larger, and the helical pitch is shorter. （１，１） and minimum position B （２，１） and the maximum position A （３，１） and minimum position B （２，１） The helical pitch of the helical structure formed by the liquid crystal compound LC is at the maximum position A （１，１） and maximum position A （３，１） and the minimum position B （２，１） The helical pitch of the helical groove 10 has an intermediate region, which is larger than the helical pitch of the helical groove 10 in the helical groove 10 .

[0038] The lower diagram of Fig. 4 is a schematic diagram showing the relationship between the magnitude and position of the helical pitch of the cholesteric liquid crystal layer 12 shown in the upper diagram of Fig. 4. The vertical axis represents the magnitude of the helical pitch, and the horizontal axis represents the position in the Y direction in the plane. As shown in the lower diagram of Fig. 4, the cholesteric liquid crystal layer 12 has a maximum position A along the Y direction in the plane. （１，１） From maximum position A （３，１） The magnitude of the helical pitch of the liquid crystal compound LC changes continuously toward the

[0039] The magnitude of the helical pitch can be confirmed by observation with a scanning electron microscope (SEM). When a V-V' cross section of the cholesteric liquid crystal layer 12 along the Y direction is observed with an SEM, a striped pattern is observed in which lines of bright areas (bright lines) and lines of dark areas (dark lines) derived from the cholesteric liquid crystal phase are alternately arranged in the thickness direction. The observed striped pattern has a periodic wave structure with amplitude in the thickness direction of the cholesteric liquid crystal layer 12, and the spacing between the bright lines is large at a location corresponding to the maximum position A and small at a location corresponding to the minimum position B. The magnitude of the helical pitch (the size of one turn of the spiral) corresponds to the value obtained by doubling the distance from the center position of any bright line to the center position of the adjacent bright line in the striped pattern observed with an SEM.

[0040] In the cholesteric liquid crystal layer 12, the magnitudes of the helical pitches at maximum positions A and minimum positions B alternately arranged along both the X and Y directions satisfy the following relationship: The magnitude of the helical pitch at maximum position A (maximum value of the helical pitch) is in the range of 350 to 600 nm, and the magnitude of the helical pitch at minimum position B (minimum value of the helical pitch) is in the range of 150 to 300 nm. The magnitude of the helical pitch at maximum position A (maximum value of the helical pitch) is more preferably in the range of 350 to 550 nm. The magnitude of the helical pitch at minimum position B (maximum value of the helical pitch) is more preferably in the range of 150 to 280 nm.

[0041] Along the X direction, a maximum position A and a minimum position B (for example, in FIG. 3, the maximum position A （１，１） and minimum position B （１，１） , maximum position A（１，２） and minimum position B （１，１） ), the difference between the magnitude of the helical pitch at maximum position A (maximum value of helical pitch) and the magnitude of the helical pitch at minimum position B (minimum value of helical pitch) is 100 nm or more. In other words, when an arbitrary maximum position A is defined as a first position and a position indicating minimum position B adjacent to the first position along the X direction is defined as a second position, the difference between the magnitude of the helical pitch at the first position (maximum value of helical pitch) and the magnitude of the helical pitch at the second position (minimum value of helical pitch) is 100 nm or more. Note that the upper limit of the difference in magnitude of the helical pitch at maximum position A and minimum position B adjacent to each other along the X direction is, for example, 1,000 nm or less. The difference in magnitude of the helical pitch at maximum position A and minimum position B adjacent to each other along the X direction is preferably 100 to 500 nm, and more preferably 150 to 400 nm.

[0042] In addition, a maximum position A and a minimum position B (for example, in FIG. 4, the maximum position A （１，１） and minimum position B （２，１） , maximum position A （３，１） and minimum position B （２，１） ), the difference between the magnitude of the helical pitch at maximum position A (maximum value of helical pitch) and the magnitude of the helical pitch at minimum position B (minimum value of helical pitch) is 100 nm or more. In other words, when an arbitrary maximum position A is defined as a first position and a position indicating minimum position B adjacent to the first position along the Y direction is defined as a third position, the difference between the magnitude of the helical pitch at the first position (maximum value of helical pitch) and the magnitude of the helical pitch at the third position (minimum value of helical pitch) is 100 nm or more. Note that the upper limit of the difference in magnitude of the helical pitch at maximum position A and minimum position B adjacent to each other along the Y direction is, for example, 1,000 nm or less. The difference in magnitude of the helical pitch at maximum position A and minimum position B adjacent to each other along the Y direction is preferably 100 to 500 nm, and more preferably 150 to 400 nm.

[0043] The cholesteric liquid crystal layer 12 has maximum positions A adjacent to each other along the X direction (for example, maximum positions A in FIG. 3).（１，１） and maximum position A （１，２） The distance between the maximum positions A adjacent to each other along the X direction is preferably 120 to 280 nm, and more preferably 150 to 250 nm. In addition, the cholesteric liquid crystal layer 12 has a distance between the maximum positions A adjacent to each other along the Y direction (for example, the maximum positions A in FIG. 4). （１，１） and maximum position A （３，１） The distance between the maximum positions A adjacent to each other along the Y direction is preferably 120 to 280 nm, and more preferably 150 to 250 nm.

[0044] In the cholesteric liquid crystal layer 12, the magnitude of the helical pitch of the liquid crystal compound may change continuously in the ZX direction, which is at an angle of 45° to the Y direction relative to the X direction (hereinafter also referred to as the ZX direction), and in the ZY direction, which is perpendicular to the ZX direction. The maximum and minimum values ​​of the helical pitch of the liquid crystal compound may also alternate. In such a case, it is typically preferable that the difference in the magnitude of the helical pitch at the position where the helical pitch is at its maximum value (hereinafter referred to as the "maximum position ZA") and the position where the helical pitch is at its minimum value (hereinafter referred to as the "maximum position ZB"), which are alternately arranged along the ZX and ZY directions, between the maximum position ZA and the minimum position ZB adjacent to each other along the ZA direction, and between the maximum position ZA and the minimum position ZB adjacent to each other along the ZB direction, is less than 100 nm.

[0045] As described above, the selective reflection center wavelength λ of the cholesteric liquid crystal phase depends on the helical pitch P in the cholesteric liquid crystal phase and follows the relationship λ = n × P with the average refractive index n of the cholesteric liquid crystal phase. Therefore, the larger the helical pitch, the longer the selective reflection center wavelength of the cholesteric liquid crystal phase. The cholesteric liquid crystal layer 12 has alternating maximum positions A and minimum positions B along the X and Y directions, where the magnitude of the helical pitch satisfies the above relationship, thereby reflecting light having a selective reflection center wavelength derived from each helical pitch. Therefore, the reflection spectrum can have a broad reflection band with a half-width of 150 nm or more in the visible light region. As a result, it is possible to reproduce colors within a predetermined range on the xy chromaticity diagram of the CIE 1931 color space. Furthermore, the cholesteric liquid crystal layer 12 has adjacent maximum positions A (e.g., maximum positions A in FIG. 3 ) along the X and Y directions. （１，１） and maximum position A （１，２） , the maximum position A in FIG. （１，１） and maximum position A （３，１）、 With this configuration, when the reflected light from the cholesteric liquid crystal layer is viewed, the human eye cannot separate the colors, so the graininess (roughness of the image) is less noticeable.

[0046] The lower limit of the thickness of the cholesteric liquid crystal layer 12 is preferably 0.5 μm or more, more preferably 2 μm or more, and even more preferably 3 μm or more, in order to provide a clearer reflected color, and the upper limit of the thickness of the cholesteric liquid crystal layer is preferably 10 μm or less, more preferably 6 μm or less, and even more preferably 4 μm or less, in order to facilitate the formation of the cholesteric liquid crystal layer.

[0047] The haze value of the cholesteric liquid crystal layer is preferably 2.0% or less, more preferably 1.8% or less, even more preferably 1.3% or less, and particularly preferably 1.0% or less, in order to provide the cholesteric liquid crystal layer with superior transparency. The lower limit is 0% or more. The haze value is a value measured using a haze meter (e.g., NDH-5000, manufactured by Nippon Denshoku Industries Co., Ltd.) by a method in accordance with JIS K 7105.

[0048] [Method for forming decorative film] An example of a method for manufacturing a decorative film is a manufacturing method having a step X and a step Y. When the liquid crystal compound has a polymerizable group, the method for manufacturing a decorative film is preferably a manufacturing method having a step X, a step Y, and a step Z.

[0049] Step X: A step of contacting a substrate with a composition containing a liquid crystal compound and a chiral agent to form a composition layer on the substrate in which the liquid crystal compound is oriented and in a cholesteric liquid crystal phase state. Step Y: A step of exposing the composition layer through a mask having a predetermined halftone dot pattern (a step of changing the helical twisting power of the chiral agent). Step Z: A step of curing the composition layer that has undergone Step Y (a step of fixing the cholesteric liquid crystal phase). The procedures of Steps X to Z are described in detail below.

[0050] <Step X> Step X is a step of bringing a substrate into contact with a composition containing a liquid crystal compound and a chiral agent to form, on the substrate, a composition layer in which the liquid crystal compound is oriented and in a cholesteric liquid crystal phase state.

[0051] The composition containing the liquid crystal compound and the chiral agent used in step X will be described later. Examples of the substrate used in step X include those described as the substrate of the decorative film 1. Furthermore, the above-mentioned underlayer may be further formed on the surface of the substrate on the side where the cholesteric liquid crystal layer is formed.

[0052] The method for bringing the substrate into contact with the composition is not particularly limited, and examples thereof include a method in which the composition is applied to the substrate, and a method in which the substrate is immersed in the composition.

[0053] After contacting the substrate with the composition, a drying treatment may be carried out, if necessary, to remove the solvent from the composition layer on the substrate. After contacting the substrate with the composition, a heat treatment is preferably carried out to promote the alignment of the liquid crystal compound and to create a cholesteric liquid crystal phase. The heating temperature is preferably 40 to 120°C, more preferably 60 to 100°C. The heating time is preferably 1 to 10 minutes, more preferably 2 to 6 minutes.

[0054] <Step Y> Step Y is a step of exposing the composition layer through a mask having a predetermined halftone dot pattern. Step Y changes the helical twisting power of the chiral agent at the exposed portions of the composition layer (the positions of the openings in the mask), increasing or decreasing the helical pitch of the liquid crystal compound. That is, for example, when a composition layer in which the liquid crystal compound obtained in step X has a cholesteric liquid crystal orientation is exposed through a mask having a pattern in which the halftone dot portions are non-openings, the helical twisting power of the chiral agent at positions corresponding to the non-opening halftone dot portions remains substantially unchanged, while the helical twisting power of the chiral agent at positions corresponding to the exposed portions increases or decreases. As a result, positions at which the helical pitch of the liquid crystal compound is maximized and positions at which the helical pitch of the liquid crystal compound is minimized can be formed within the plane of the composition layer. Note that if the chiral agent contained in the composition layer is a chiral agent whose helical twisting power increases upon exposure, the helical twisting power of the chiral agent increases and the helical pitch decreases at positions corresponding to the exposed portions. On the other hand, if the chiral agent contained in the composition layer is a chiral agent whose helical twisting power decreases upon exposure, the helical twisting power of the chiral agent will decrease and the helical pitch will increase at positions corresponding to exposed areas. Furthermore, during exposure treatment, even positions corresponding to non-openings in the mask (unexposed areas) will typically be exposed to light leaking from the light source due to diffracted light, etc. In particular, when a substrate on which a composition layer is disposed is transported into an exposure device to perform exposure treatment, light from the light source often hits the substrate obliquely due to manufacturing reasons. As a result, the edge regions corresponding to non-openings in the mask are likely to be weakly exposed, often increasing or decreasing the helical twisting power of the chiral agent present at these exposed positions. Therefore, when exposure treatment is performed using a mask having a predetermined halftone dot pattern, a region having an intermediate helical pitch may be formed between the maximum position A and the minimum position B in one direction (X direction) and the perpendicular direction (Y direction) within the plane of the composition layer, as shown in Figures 3 and 4. That is, in one direction (X direction) within the plane of the composition layer and in the direction perpendicular thereto (Y direction), the magnitude of the helical pitch of the liquid crystal compound changes continuously, and a region can be formed in which maximum and minimum values ​​of the pitch appear alternately.

[0055] The chiral agent contained in the composition preferably undergoes photoisomerization upon exposure treatment, resulting in a change in its helical twisting power. In this exposure treatment, the degree of change in the helical twisting power of the chiral agent can be adjusted by appropriately adjusting the exposure dose and / or exposure wavelength. The exposure wavelength is preferably, for example, 300 to 400 nm, more preferably 300 to 380 nm. Examples of light sources include light-emitting diodes (UV-LEDs) that emit ultraviolet light, ultra-high pressure mercury lamps, high-pressure mercury lamps, and metal halide lamps. The exposure dose is, for example, 5 to 2,000 mJ / cm. ２ is preferred, and 10 to 1,000 mJ / cm ２ is more preferred.

[0056] The exposure treatment can be carried out in an environment of room temperature (25°C), or may be carried out under heated conditions of less than 65°C.

[0057] (Mask) In process Y, a mask having a predetermined halftone dot pattern is used. A mask having a predetermined halftone dot pattern is preferably a mask in which halftone dots (non-openings) are arranged at approximately regular intervals in both one direction in the plane and the direction perpendicular thereto, such as an AM screen mask. Examples of halftone dot arrangement include a rhombic lattice pattern, a square lattice pattern, and a hexagonal lattice pattern. The cholesteric liquid crystal layer 12 shown in FIG. 2 can be formed using a mask (specifically, an AM screen mask) in which halftone dots are arranged in a rhombic lattice pattern as shown in FIG. 5. Examples of halftone dot shapes include circular (perfect circle, elliptical) and rectangular, with circular shapes being preferred and circular shapes being more preferred. The size of the halftone dots is preferably a size corresponding to a circle-equivalent diameter of 50 to 150 μm, more preferably 70 to 140 μm. The distance between halftone dots is preferably 100 to 300 μm, more preferably 150 to 250 μm. The term "dot-to-dot distance" as used herein refers to the distance between adjacent dots in a dot pattern that are arranged approximately regularly in both one direction and a direction perpendicular to the one direction. It also refers to the distance between the centers of adjacent dots (i.e., in the case of circular dots, the distance between the centers of adjacent dots). The dot-to-dot distance between dots that are arranged approximately regularly in one direction within a plane and in a direction perpendicular to the one direction may be different from the dot-to-dot distance between dots that are arranged approximately regularly in the direction perpendicular to the one direction.

[0058] The method for producing a mask having a halftone dot pattern is not particularly limited, and it can be produced by, for example, gravure printing or screen printing. It can also be produced by forming a pattern on a vapor-deposited film of a metal such as chromium by lithography. Furthermore, it can also be produced by using a laser photoplotter system to form halftone dots on a printing plate by turning on and off laser irradiation based on digital image data.

[0059] <Step Z> Step Z is a step of subjecting the composition layer that has undergone step Y to a curing treatment. The method of curing is not particularly limited, and examples thereof include photocuring and heat curing, with photocuring being preferred. When photocuring is performed as the curing treatment, the composition in step X preferably contains a photopolymerization initiator. The wavelength of the light irradiated in the photocuring treatment is preferably different from the wavelength of the light used in the exposure treatment in step Y, and the photopolymerization initiator preferably does not exhibit sensitivity to the wavelength of the light used in the exposure treatment. In particular, the photocuring treatment is preferably performed by ultraviolet irradiation. The exposure dose is, for example, 100 to 1,000 mJ / cm. ２ is preferred, and 200 to 800 mJ / cm ２ is more preferred.

[0060] Furthermore, the curing treatment in step Z is preferably carried out under heating and / or in a low-oxygen atmosphere. The heating temperature is preferably within a temperature range in which a cholesteric liquid crystal phase is exhibited, for example, 25 to 140°C is preferred, and 30 to 100°C is more preferred. The oxygen concentration is preferably 5,000 volume ppm or less, more preferably 1,000 volume ppm or less, and even more preferably 200 volume ppm or less. The oxygen concentration can be adjusted by known methods such as nitrogen substitution. The polymerization reaction rate after curing the composition is preferably 50% or more, more preferably 60% or more. The polymerization reaction rate can be confirmed by measuring the consumption rate of polymerizable functional groups using IR (infrared absorption spectrometry) absorption spectroscopy.

[0061] By carrying out the curing treatment in step Z, a layer in which the cholesteric liquid crystal phase is fixed is formed.

[0062] (Composition) The composition used in step X will be described below. The composition contains a liquid crystal compound and a chiral agent. Various components that may be contained in the composition will be described below.

[0063] Liquid Crystal Compound The composition contains a liquid crystal compound. The liquid crystal compound refers to a compound that exhibits liquid crystallinity. The phrase "a compound exhibits liquid crystallinity" means that the compound has the property of exhibiting an intermediate phase between a crystalline phase (low temperature side) and an isotropic phase (high temperature side) when the temperature is changed. As a specific observation method, the optical anisotropy and fluidity derived from the liquid crystal phase can be confirmed by observing the compound under a polarizing microscope while heating or cooling it using a Mettler Toledo FP90 hot stage system or the like.

[0064] The liquid crystal compound is not particularly limited, and examples thereof include rod-shaped liquid crystal compounds and discotic liquid crystal compounds. The rod-shaped liquid crystal compound and discotic liquid crystal compound may be low-molecular-weight or high-molecular-weight compounds. The term "high-molecular-weight compound" as used herein refers to a compound having a degree of polymerization of 100 or more ("Polymer Physics: Phase Transition Dynamics," by Masao Doi, p. 2, Iwanami Shoten, 1992).

[0065] Among the liquid crystal compounds, rod-shaped liquid crystal compounds are preferred, such as azomethines, azoxy compounds, cyanobiphenyls, cyanophenyl esters, benzoates, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines, phenyldioxanes, tolanes, and alkenylcyclohexylbenzonitriles.

[0066] The liquid crystal compound may be either polymerizable or non-polymerizable, but polymerizable is preferred because it can fix the cholesteric liquid crystal phase. That is, a liquid crystal compound having a polymerizable group is preferred. The number of polymerizable groups possessed by the liquid crystal compound is preferably one or more, more preferably two or more. The upper limit is not particularly limited, and is, for example, preferably six or less, more preferably three or less. The number of polymerizable groups possessed by the liquid crystal compound is particularly preferably two.

[0067] The type of polymerizable group is not particularly limited, and examples thereof include unsaturated polymerizable groups, epoxy groups, and aziridinyl groups, with ethylenically unsaturated groups or ring-polymerizable groups being more preferred.Specific examples of the polymerizable group include (meth)acryloyl groups, vinyl groups, styryl groups, allyl groups, epoxy groups, and oxetane groups being preferred, with (meth)acryloyl groups being more preferred.The polymerizable group can be introduced into the molecules of the liquid crystal compound by various methods.

[0068] Specific examples of liquid crystal compounds include those described in Makromol. Chem., Vol. 190, p. 2255 (1989), Advanced Materials Vol. 5, p. 107 (1993), U.S. Patent No. 4,683,327, U.S. Patent No. 5,622,648, U.S. Patent No. 5,770,107, WO 1995 / 022586, WO 1995 / 024455, WO 1997 / 000600, WO 1998 / 023580, WO 1998 / 052905, WO 2016 / 194327, WO 2016 / 052367, JP-A-1-272551, JP-A-6-016616, JP-A-7-110469, JP-A-11-080081, and, liquid crystal compounds described in JP-A-2001-328973, and the like.

[0069] The average refractive index of the liquid crystal compound at a wavelength of 589.3 nm is preferably 1.40 to 1.60, more preferably 1.45 to 1.55.

[0070] The liquid crystal composition may contain two or more liquid crystal compounds. When two or more liquid crystal compounds are used in combination, the alignment temperature may decrease.

[0071] The lower limit of the content of the liquid crystal compound in the composition is preferably 40% by mass or more, more preferably 60% by mass or more, and even more preferably 75% by mass or more, based on the total solid content of the composition. The upper limit is preferably 99.9% by mass or less, more preferably 99.5% by mass or less, based on the total solid content of the composition. The solid content refers to components other than the solvent in the composition. Components other than the solvent are considered to be solids even if they are liquid. The composition may contain one liquid crystal compound or two or more liquid crystal compounds. When two or more liquid crystal compounds are used, the total content is preferably within the above range.

[0072] -Chiral Agent- The composition contains a chiral agent. The chiral agent is preferably a photosensitive chiral agent whose helical twisting power changes upon irradiation with light (hereinafter, also simply referred to as "photosensitive chiral agent"). The photosensitive chiral agent may be liquid crystalline or non-liquid crystalline. The photosensitive chiral agent may be a chiral agent containing an asymmetric carbon atom, or may be an axially asymmetric compound or a planar asymmetric compound that does not contain an asymmetric carbon atom. Examples of photosensitive chiral agents include chiral agents whose helical twisting power decreases upon irradiation with light, and chiral agents whose helical twisting power increases upon irradiation with light.

[0073] Examples of photosensitive chiral agents include so-called photoreactive chiral agents. A photoreactive chiral agent has a chiral moiety and a photoreactive moiety that undergoes a structural change upon irradiation with light, and is, for example, a compound that significantly changes the twisting power of a liquid crystal compound depending on the amount of irradiation. Examples of photoreactive moieties that undergo a structural change upon irradiation with light include photochromic compounds (Kingo Uchida, Masahiro Irie, Chemical Industry, Vol. 64, p. 640, 1999; Kingo Uchida, Masahiro Irie, Fine Chemical, Vol. 28(9), p. 15, 1999). The structural change refers to decomposition, addition reaction, isomerization, racemization, [2+2] photocyclization, dimerization, and the like that occur upon irradiation of the photoreactive moiety with light, and the structural change may be irreversible. Examples of chiral moieties include the asymmetric carbons described in Hiroyuki Nodaira, Chemistry Review, No. 22, Chemistry of Liquid Crystals, p. 73, 1994.

[0074] Examples of the photoreactive chiral agent include the photoreactive chiral agents described in paragraphs 0044 to 0047 of JP-A No. 2001-159709, the optically active compounds described in paragraphs 0019 to 0043 of JP-A No. 2002-179669, the optically active compounds described in paragraphs 0020 to 0044 of JP-A No. 2002-179633, the optically active compounds described in paragraphs 0016 to 0040 of JP-A No. 2002-179670, the optically active compounds described in paragraphs 0017 to 0050 of JP-A No. 2002-179668, and the optically active compounds described in paragraph 0018 of JP-A No. 2002-180051. to 0044, optically active compounds described in paragraphs 0016 to 0055 of JP-A No. 2002-338575, optically active isosorbide derivatives, photoreactive optically active compounds described in paragraphs 0023 to 0032 of JP-A No. 2002-080478, photoreactive chiral agents described in paragraphs 0019 to 0029 of JP-A No. 2002-080851, optically active compounds described in paragraphs 0022 to 0049 of JP-A No. 2002-179681, optically active compounds described in paragraphs 0015 to 0044 of JP-A No. 2002-302487, optically active compounds described in paragraphs 0016 to 0055 of JP-A No. 2002-338575, optically active isosorbide derivatives, photoreactive optically active compounds described in paragraphs 0023 to 0032 of JP-A No. 2002-080478, photoreactive chiral agents described in paragraphs 0019 to 0029 of JP-A No. 2002-080851, optically active compounds described in paragraphs 0022 to 0049 of JP-A No. 2002-302487, optically active polyesters described in paragraphs 0015 to 0050 of JP-A No. 38668, binaphthol derivatives described in paragraphs 0019 to 0041 of JP-A No. 2003-055315, optically active fulgide compounds described in paragraphs 0008 to 0043 of JP-A No. 2003-073381, optically active isosorbide derivatives described in paragraphs 0015 to 0057 of JP-A No. 2003-306490, optically active isosorbide derivatives described in paragraphs 0015 to 0041 of JP-A No. 2003-306491, optically active isosorbide derivatives described in paragraphs 0015 to 0049 of JP-A No. 2003-313187 optically active isosorbide derivatives described in paragraphs

[0015] to

[0057] of JP-A-2003-313188; optically active isomannide derivatives described in paragraphs

[0015] to

[0049] of JP-A-2003-313189; optically active polyester / amides described in paragraphs

[0015] to

[0052] of JP-A-2003-313292; optically active compounds described in paragraphs

[0012] to

[0053] of WO2018 / 194157; and optically active compounds described in paragraphs

[0020] to

[0049] of JP-A-2002-179682.

[0075] The photosensitive chiral agent preferably has a double bond in the molecule that undergoes photoisomerization or photodimerization, since this provides a better rate of change in helical twisting power upon irradiation with light. Specifically, the chiral agent containing a double bond that undergoes photoisomerization or photodimerization is preferably a chiral agent containing a partial structure selected from the group consisting of cinnamoyl, stilbene, chalcone, azobenzene, and azomethine, and more preferably a chiral agent containing a partial structure selected from the group consisting of cinnamoyl, stilbene, and chalcone, since it has low visible light absorption. In particular, the double bond that undergoes photoisomerization or photodimerization is preferably a cis structure, since this provides a low initial helical twisting power (before irradiation with light) and a better rate of change in helical twisting power upon irradiation with light. That is, for example, in the case of a chiral agent containing stilbene as a partial structure, a chiral agent containing cis-stilbene as a partial structure is preferred; in the case of a chiral agent containing chalcone as a partial structure, a chiral agent containing cis-chalcone as a partial structure is preferred; and in the case of a chiral agent containing cinnamoyl as a partial structure, a chiral agent containing cis-cinnamoyl as a partial structure is preferred.

[0076] Furthermore, the photosensitive chiral agent preferably contains a partial structure selected from the group consisting of an isosorbide partial structure (a partial structure derived from isosorbide), an isomannide partial structure (a partial structure derived from isomannide), and a binaphthyl partial structure, because these have a superior rate of change in helical twisting power. In this specification, the binaphthyl partial structure, the isosorbide partial structure, and the isomannide partial structure each refer to the following structures. The portion in the binaphthyl partial structure where the solid line and the dashed line are parallel represents a single bond or a double bond. The binaphthyl partial structure below may also be condensed with another ring structure. In the structures shown below, * represents a bond position.

[0077]

[0078] The photosensitive chiral agent may have a polymerizable group. The type of the polymerizable group is not particularly limited, and is preferably a functional group capable of undergoing an addition polymerization reaction, more preferably a polymerizable ethylenically unsaturated group or a ring-polymerizable group, and still more preferably a (meth)acryloyl group, a vinyl group, a styryl group, or an allyl group.

[0079] The helical twist power (HTP) of a chiral dopant is a factor that indicates the helical orientation ability, as expressed by the following formula (A): HTP=1 / (helical pitch length (unit: μm)×concentration of chiral dopant relative to liquid crystal compound (mass %)) [μm -1 The helical pitch length refers to the length of the pitch P (=helical period) of the helical structure of the cholesteric liquid crystal phase, and can be measured by the method described on page 196 of Liquid Crystal Handbook (published by Maruzen Co., Ltd.). The helical twisting power (HTP) of a chiral agent can also be expressed by the following formula (B): Formula (B): HTP = (average refractive index of liquid crystal compound) / {(concentration of chiral agent relative to liquid crystal compound (mass%)) × (central reflection wavelength (nm))} [μm -1 ]

[0080] The content of the chiral dopant in the composition is preferably 2.0% by mass or more, more preferably 3.0% by mass or more, relative to the total mass of the liquid crystal compound. Furthermore, the upper limit of the total content of the chiral dopant in the liquid crystal composition is preferably 18.0% by mass or less, more preferably 15.0% by mass or less, and even more preferably 12.0% by mass or less, relative to the total mass of the liquid crystal compound, in terms of suppressing haze in the cholesteric liquid crystal layer. The composition may contain one chiral dopant alone, or two or more dopant types. When two or more dopant types are used, the total content thereof is preferably within the above range.

[0081] —Polymerization Initiator— The composition may contain a polymerization initiator. Examples of polymerization initiators include photopolymerization initiators and thermal polymerization initiators, with photopolymerization initiators capable of initiating a polymerization reaction upon ultraviolet irradiation being preferred. Examples of photopolymerization initiators include alkylphenone compounds, α-carbonyl compounds, acyloin ethers, α-hydrocarbon-substituted aromatic acyloin compounds, polynuclear quinone compounds, phenazine compounds, and oxadiazole compounds. When the composition contains a polymerization initiator, the content of the polymerization initiator in the composition is not particularly limited, but is preferably 0.1 to 20.0% by mass, and more preferably 1.0 to 8.0% by mass, relative to the total mass of the liquid crystal compound. The composition may contain one type of polymerization initiator alone, or two or more types. When two or more types are used, the total content thereof is preferably within the above-mentioned range.

[0082] -Surfactant- The composition may contain a surfactant that contributes to stable or rapid formation of a liquid crystal phase (e.g., a nematic phase, a cholesteric phase). Examples of surfactants include fluorine-containing (meth)acrylate polymers, compounds represented by general formulas (X1) to (X3) described in WO 2011 / 162291, compounds represented by general formula (I) described in paragraphs

[0082] to

[0090] of JP 2014-119605 A, and compounds described in paragraphs

[0020] to

[0031] of JP 2013-47204 A (Japanese Patent No. 5774518 A). These compounds can reduce the tilt angle of liquid crystal compound molecules at the air interface of the layer, or can align the liquid crystal compound substantially horizontally. In this specification, "horizontal alignment" refers to a state in which the molecular axis of the liquid crystal compound (corresponding to the long axis of the liquid crystal compound when the liquid crystal compound is a rod-shaped liquid crystal compound) is parallel to the surface (film surface) of the composition layer. However, this does not require strict parallelism, and in this specification, it refers to an alignment in which the tilt angle with the film surface is less than 20 degrees. When the liquid crystal compound is horizontally aligned near the air interface, alignment defects are less likely to occur, resulting in high transparency in the visible light region. On the other hand, if the molecules of the liquid crystal compound are aligned at a large tilt angle with respect to the film surface, for example, in a cholesteric phase, their helical axes will deviate from the film surface normal, which is undesirable because it reduces reflectivity, causes fingerprint patterns, increases haze, or exhibits diffraction. Specific examples of surfactants include the compounds described in paragraphs 0082 to 0090 of JP-A No. 2014-119605, the compounds described in paragraphs 0031 to 0034 of JP-A No. 2012-203237, the compounds described in paragraphs 0092 and 0093 of JP-A No. 2005-099248, and the compounds described in paragraphs 0076 to 0078 and 0082 to 0085 of JP-A No. 2002-129162. Specific examples of surfactants also include the fluorine-containing (meth)acrylate polymers described in paragraphs 0018 to 0043 of JP-A No. 2007-272185.

[0083] When the composition contains a surfactant, the content of the surfactant is not particularly limited, but is preferably 0.001 to 10% by mass, and more preferably 0.05 to 3% by mass, relative to the total mass of the liquid crystal compound. The composition may contain one surfactant alone, or two or more surfactants. When two or more surfactants are used, the total content thereof is preferably within the above range.

[0084] -Solvent- The composition may contain a solvent. The solvent is preferably capable of dissolving each component of the composition. Examples include methyl ethyl ketone, cyclohexanone, and mixed solvents thereof. When the composition contains a solvent, the content of the solvent in the composition is preferably an amount that makes the solids concentration of the composition 5 to 50 mass %, more preferably an amount that makes 10 to 40 mass %. The composition may use one solvent alone, or two or more solvents. When two or more solvents are used, the total content thereof is preferably within the above range.

[0085] -Additives- The composition may contain additives other than the components described above. Examples of other additives include antioxidants, UV absorbers, sensitizers, stabilizers, plasticizers, chain transfer agents, polymerization inhibitors, antifoaming agents, leveling agents, thickeners, flame retardants, dispersants, crosslinking agents, photoisomerizable compounds, monofunctional monomers, polyfunctional monomers, and coloring materials such as dyes and pigments.

[0086] The use of the decorative sheet of the present invention is not particularly limited, but it is preferably used, for example, to decorate the surfaces of home appliances, office equipment, automobile parts, etc. More specifically, it is more preferably used to decorate the surfaces of display elements mounted on home appliances, office equipment, automobile parts, etc.

[0087] [Display Device] The display device (image display device) of the present invention comprises a display element and a decorative sheet disposed on the surface of the display element. The decorative sheet is preferably disposed on one surface of the display element, more preferably on the viewing side of the display element. The display element is not particularly limited, and examples thereof include a liquid crystal cell, an electroluminescence (EL) display panel, and a plasma display panel, with a liquid crystal cell or an EL display panel being preferred. That is, the display device is preferably a liquid crystal display device using a liquid crystal cell as the display element, or an EL display device using an EL display panel as the display element. The light emitted from the display element is preferably linearly polarized or circularly polarized, with linearly polarized light being more preferred.

[0088] [Liquid Crystal Display Device] The liquid crystal cell used in the liquid crystal display device is not particularly limited, but is preferably VA (Vertical Alignment) mode, OCB (Optically Compensated Bend) mode, IPS (In-Plane-Switching) mode, or TN (Twisted Nematic). In a TN mode liquid crystal cell, rod-shaped liquid crystal molecules (rod-shaped liquid crystal compounds) are aligned substantially horizontally when no voltage is applied, and are further aligned with a twist angle of 60 to 120°. TN mode liquid crystal cells are most commonly used as color TFT liquid crystal display devices, and are described in many literature. In a VA mode liquid crystal cell, rod-shaped liquid crystal molecules are aligned substantially vertically when no voltage is applied. VA mode liquid crystal cells include (1) narrowly defined VA mode liquid crystal cells in which rod-shaped liquid crystal molecules are aligned substantially vertically when no voltage is applied and substantially horizontally when a voltage is applied (described in Japanese Patent Application Laid-Open No. 2-176625), (2) multi-domain MVA mode (multi-domain vertical alignment) liquid crystal cells in which VA mode is multi-domained to widen the viewing angle (described in SID97, Digest of Tech. Papers (Proceedings) 28 (1997) 845), (3) n-ASM (axially symmetric aligned microcell) mode liquid crystal cells in which rod-shaped liquid crystal molecules are aligned substantially vertically when no voltage is applied and substantially horizontally when a voltage is applied (described in Proceedings of the Japan Liquid Crystal Symposium 58-59 (1998)), and (4) SURVIVAL mode liquid crystal cells (presented at LCD (Liquid Crystal Display) International 98). Furthermore, any of a PVA (Patterned Vertical Alignment) type, an optical alignment type, and a PSA (Polymer-Sustained Alignment) type may be used. Details of these modes are described in Japanese Patent Laid-Open No. 2006-215326 and Japanese Patent Laid-Open No. 2008-538819. In an IPS mode liquid crystal cell, rod-shaped liquid crystal molecules are aligned substantially parallel to the substrates, and when an electric field parallel to the substrate surfaces is applied, the liquid crystal molecules respond in a planar manner.In the IPS mode, black display occurs when no voltage is applied, and the absorption axes of the pair of upper and lower polarizing plates are perpendicular to each other. Methods of using an optical compensation sheet to reduce light leakage during black display in oblique directions and improve the viewing angle are disclosed in JP-A Nos. 10-54982, 11-202323, 9-292522, 11-133408, 11-305217, and 10-307291.

[0089] [EL Display Device] The EL display panel used in the EL display device can be any of various known EL display panels used in self-luminous display devices that use inorganic EL display panels and organic EL display panels. An organic EL display panel is a display panel configured using organic EL elements in which an organic light-emitting layer (organic electroluminescence layer) is sandwiched between electrodes (between a cathode and an anode). The configuration of the organic EL display panel is not particularly limited, and any known configuration can be used.

[0090] The inorganic EL display panel may be an array of inorganic R-, G-, and B-light-emitting elements. The inorganic EL elements are so-called LEDs (light-emitting diodes). Furthermore, the inorganic EL display panel may be an EL display panel configured by two-dimensionally arranging light-emitting sections having minute inorganic R-, G-, and B-light-emitting elements. The area ratio of the light-emitting elements in an EL display panel using minute inorganic EL elements is not limited. The area ratio of the light-emitting elements in the EL display panel is preferably 30% or less, more preferably 10% or less, even more preferably 3% or less, and even more preferably 1% or less. In order to reduce the area ratio of the light-emitting elements, it is necessary to increase the output of the light-emitting elements to achieve sufficient brightness. In this respect, inorganic EL elements (so-called LEDs) are preferred as the light-emitting elements in the EL display panel. By using inorganic EL elements, sufficient brightness can be obtained even when the area ratio of the light-emitting elements is within the preferred range of 30% or less, more preferably 10% or less, even more preferably 3% or less, and even more preferably 1% or less.

[0091] In order to obtain a display device that achieves high resolution and sufficient brightness while reducing the area ratio of the light-emitting element, it is preferable to use a fine inorganic EL light-emitting element. As the fine inorganic EL light-emitting element, an inorganic EL light-emitting element in which the diameter of a circle inscribed in the inorganic EL light-emitting element is 360 μm or less is preferable, an inorganic EL light-emitting element in which the diameter is 200 μm or less is more preferable, an inorganic EL light-emitting element in which the diameter is 100 μm or less is even more preferable, and an inorganic EL light-emitting element in which the diameter is 50 μm or less is even more preferable.

[0092] In one embodiment, the EL display panel may be a transparent substrate. Preferably, the EL display panel may have EL light-emitting elements arranged on a transparent substrate. By using a transparent substrate, a display device with a high design quality can be realized, in which the background of the display device can be seen through and reflection of external light on the substrate surface is suppressed.

[0093] The EL display panel has R, G, and B light-emitting elements and is capable of displaying full-color images, but the present invention is not limited to this. For example, the EL substrate may have only R light-emitting elements, only G light-emitting elements, or only B light-emitting elements and be capable of displaying monochrome images (single-color images). Alternatively, the EL substrate may have R and G light-emitting elements, or R and B light-emitting elements, or G and B light-emitting elements and be capable of displaying two-color images.

[0094] When a display device equipped with a decorative sheet does not display an image using a display element, the pattern of the decorative sheet itself is visible. On the other hand, when an image is displayed using a display element, the pattern of the decorative sheet itself is not strongly visible due to bright light from an oblique angle, and the displayed image can be clearly seen.

[0095] A preferred embodiment of the display device of the present invention is an interior of an automobile.

[0096] The present invention will be described in more detail below with reference to examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the examples shown below.

[0097] Example 1 Preparation of Substrate A polyethylene terephthalate film having an easy-adhesion layer on one side (Cosmoshine A4160, manufactured by Toyobo Co., Ltd., thickness 100 μm, width 330 mm, length 2000 m) was prepared as a substrate.

[0098] [Preparation of substrate with optical mask layer] An optical mask layer (hereinafter also referred to as a "printed mask layer") was provided by a printing process on the surface of the substrate on which the easy-adhesion layer was formed. Specifically, using a wet electrophotographic printer ("Indigo 6900" (manufactured by Hewlett-Packard)), a halftone dot pattern (width 300 mm, length 980 mm) was repeatedly printed continuously for 1500 m in the longitudinal direction of the substrate on the surface on which the easy-adhesion layer was formed. The halftone dot pattern was formed using white ink and had a 175-line AM screen tone. The halftone dots were circular, with a diameter of 100 μm. FIG. 5 shows a schematic diagram of the prepared pattern mask. As shown in FIG. 5, the pattern mask 22 has a pattern in which halftone dots 24, which are non-openings, are arranged at equal intervals in both the R direction and the C direction perpendicular to the R direction. The size of each halftone dot is the same, as shown in Table 1. The distance between adjacent halftone dots along the R direction and the distance between adjacent halftone dots along the C direction (inter-dot distance) are also the same, as shown in Table 1.

[0099] [Formation of Underlayer] Using a bar coater, underlayer-forming coating liquid 1 was applied at room temperature to the surface of the substrate opposite to the side having the optical mask layer. The amount of underlayer-forming coating liquid 1 applied was adjusted to an amount that would result in a thickness of approximately 0.8 to 1.2 μm after drying. The coating film was then dried at 80° C. for 2 minutes, and then irradiated with light from a metal halide lamp ("MAL625NAL" manufactured by GS Yuasa Corporation) at an exposure dose of 180 mJ / cm. ２ Thus, a hardened layer (underlayer) was formed.

[0100] <Coating liquid 1 for base layer formation> KAYARAD PET30 (manufactured by Nippon Kayaku Co., Ltd.) 25 parts by mass DCP (manufactured by Shin-Nakamura Chemical Co., Ltd.) 75 parts by mass Omnirad 819 (manufactured by IGM Resins B.V.) 4.0 parts by mass The following surfactant F2 0.01 parts by mass Methyl isobutyl ketone 243 parts by mass

[0101] --Surfactant F2--

[0102]

[0103] [Formation of Liquid Crystal Layer (Cholesteric Liquid Crystal Layer)] Using a bar coater, the following liquid crystal layer-forming coating liquid 1 was applied to the surface of the underlayer at room temperature. The amount of liquid crystal layer-forming coating liquid 1 applied was adjusted to an amount that would result in a thickness of approximately 2.5 to 4 μm after drying. The resulting coating film was then dried at 80°C for 2 minutes. Then, at room temperature, the dried coating film was subjected to a lithography process at an illuminance of 30 mW and an exposure dose of 40 mJ / cm through an optical mask layer on the back surface of the substrate (the surface of the substrate opposite to the side having the coating film). ２ (a step of changing the helical twisting power of the photosensitive chiral agent). Next, in a low-oxygen atmosphere (an environment with an oxygen concentration of 100 volume ppm or less), the coating film was irradiated with light from a metal halide lamp ("MAL625NAL" (GS Yuasa Corporation)) at room temperature from the surface side of the substrate on which the coating film was formed, thereby curing the coating film and forming a cured layer (a cholesteric liquid crystal layer in which the cholesteric liquid crystal phase was fixed), thereby producing a decorative film (a curing step). The irradiation here was carried out at an exposure dose of 600 mJ / cm. ２ Thereafter, a PMMA (Poly Methyl Methacrylate) film was attached to the surface of the cured layer opposite the underlayer via an acrylic adhesive G25 (manufactured by Nichiei Shinka Co., Ltd.), and only the substrate with the optical mask layer of the decorative film was peeled off, thereby transferring the cured layer and the underlayer to the PMMA film side.

[0104] <Liquid Crystal Layer Forming Coating Liquid 1> Methyl ethyl ketone: 140.5 parts by mass Mixture LC1 of the following rod-shaped liquid crystal compounds: 100.0 parts by mass Omnirad 819 (manufactured by IGM Resins B.V.): 1.0 part by mass Chiral agent A having the following structure: 8.0 parts by mass Surfactant F1 having the following structure: 0.1 parts by mass

[0105] The average refractive index (wavelength 589.3 nm) of the mixture LC1 of rod-shaped liquid crystal compounds shown below is 1.49. The chiral dopant A shown below corresponds to a chiral dopant that reduces the helical twisting power upon exposure to light.

[0106] -Mixture of rod-shaped liquid crystal compounds LC1-

[0107]

[0108] The numerical values ​​in the above formula are in mass %. Me represents a methyl group.

[0109] -Chiral Agent A-

[0110]

[0111] --Surfactant F1--

[0112]

[0113] [Evaluation of Decorative Film] The prepared decorative films were subjected to the following measurements and evaluations.

[0114] <Measurement of cholesteric pitch> The decorative film was cut out using a microtome (RX-860, Yamato Koki Kogyo Co., Ltd.). The decorative film was cut out in each direction corresponding to the R direction and C direction of the optical mask layer (see Figure 5) placed during the production of the decorative film, to obtain each test piece. Next, the cross section of the cholesteric liquid crystal layer of each obtained test piece was observed using an SEM ("SU3800", manufactured by Hitachi High-Tech Corporation). For each test piece cut out along the R direction and C direction described above, a striped pattern in which bright and dark lines derived from the cholesteric liquid crystal phase were alternately arranged in the thickness direction was observed in the SEM image. Furthermore, it was confirmed that the observed striped pattern had a periodic wave-like structure with amplitude in the thickness direction, and the spacing between the bright lines increased where the wave amplitude increased, and the spacing between the bright lines decreased where the wave amplitude decreased.

[0115] Furthermore, when the magnitude of the helical pitch of the cholesteric liquid crystal phase at each position was measured from the SEM image, it was confirmed that the magnitude of the helical pitch changed continuously in each of the obtained test pieces, and that maximum and minimum values ​​of the helical pitch alternated. Furthermore, when the helical pitch was measured at the position where the helical pitch was maximum (maximum position A) and the position where the helical pitch was minimum (minimum position B), the minimum value of the helical pitch was 230 nm, and the maximum value of the helical pitch was 480 nm for each of the obtained test pieces. The helical pitch of the cholesteric liquid crystal phase was calculated by doubling the distance between the center position of any bright line and the center position of the adjacent bright line.

[0116] As described above, the pattern mask has a pattern in which halftone dots of the same size are regularly arranged at equal intervals in both the R and C directions. That is, the distance between adjacent halftone dots along the R and C directions is the same as the distance between adjacent non-halftone dot areas along the R and C directions. Here, the non-halftone dot areas refer to non-halftone dot areas located between adjacent halftone dots along the R direction and non-halftone dot areas located between adjacent halftone dots along the C direction in a pattern in which halftone dots are regularly arranged at equal intervals in both the R and C directions. In the decorative film of Example 1, in the cholesteric liquid crystal phase, the helical pitch at positions corresponding to the halftone dots in the pattern mask remains substantially unchanged upon exposure, while the helical pitch at positions where no halftone dots are located is expanded by exposure. As a result, in both the R and C directions in the cholesteric liquid crystal phase, regions where the helical pitch is minimal are formed at positions corresponding to the halftone dots, and regions where the helical pitch is maximal are formed in the non-halftone dot areas. It was confirmed that the distance between adjacent maximum positions A observed in the SEM images of each test piece cut out along the R direction and C direction as described above is approximately the same as the distance between non-dots regularly arranged in each of the R direction and C direction on the pattern mask, i.e., is approximately the same as the distance between dots.

[0117] Furthermore, the decorative film was visually observed, and the image quality (graininess) was evaluated according to the following criteria: (Evaluation criteria) "A": The color at the position where the helical pitch is maximum and the color at the position where the helical pitch is minimum were not separated, and the color was recognized as a single color. "B": The color at the position where the helical pitch is maximum and the color at the position where the helical pitch is minimum were separated, and the color appeared grainy.

[0118] Next, the reflection spectrum of the decorative film was measured, and the half-value width was calculated based on the maximum reflectance (%). The half-value width was 280 nm. In the xy chromaticity diagram of the CIE 1931 color space obtained from the reflection spectrum, x = 0.30, y = 0.32.

[0119] [Examples 2 to 6] Decorative films of Examples 2 to 6 were prepared using the same procedure as in Example 1, except for the following changes, and measurements similar to those in Example 1 were performed. In Examples 2 to 6, SEM images of each test piece cut along the R and C directions were observed, similar to Example 1, revealing a striped pattern in which bright and dark lines derived from the cholesteric liquid crystal phase were arranged alternately in the thickness direction. Furthermore, it was confirmed that the observed striped pattern had a periodic wave-like structure with amplitude in the thickness direction, with the spacing between bright lines increasing where the wave amplitude was large and decreasing where the wave amplitude was small. Furthermore, SEM images of each test piece cut along the R and C directions were observed to reveal a continuous change in the size of the helical pitch, with maximum and minimum values ​​of the helical pitch appearing alternately. Furthermore, it was confirmed that in each test piece cut along the above-mentioned R direction and C direction, the distance between adjacent positions (maximum positions A) where the spiral pitch is maximum is approximately the same as the distance between the dots formed on the pattern mask.

[0120] Example 2 A decorative film was produced in the same manner as in Example 1, except that the exposure dose was changed from 40 mJ to 35 mJ, and measurements were carried out in the same manner as in Example 1. The results are shown in Table 1.

[0121] Example 3 A decorative film was produced in the same manner as in Example 1, except that the diameter of the dots in the optical mask layer was changed from 100 μm to 130 μm, and measurements were carried out in the same manner as in Example 1. The results are shown in Table 1.

[0122] Example 4 A decorative film was produced in the same manner as in Example 1, except that the diameter of the dots in the optical mask layer was changed from 100 μm to 67 μm, and measurements were carried out in the same manner as in Example 1. The results are shown in Table 1.

[0123] Example 5 A decorative film was produced in the same manner as in Example 1, except that the dot spacing of the optical mask layer was changed from 200 μm to 300 μm, and measurements were carried out in the same manner as in Example 1. The results are shown in Table 1.

[0124] Example 6 A decorative film was produced in the same manner as in Example 4, except that the dot spacing of the optical mask layer was changed from 200 μm to 100 μm, and measurements were carried out in the same manner as in Example 1. The results are shown in Table 1.

[0125] [Comparative Example 1] A decorative film was produced in the same manner as in Example 1, except that no optical mask layer was formed. The cholesteric pitch was observed to be 340 nm, with no continuous change observed in one direction or in the direction perpendicular to it. The half-width of the reflection spectrum of the decorative film was 65 nm, and in the xy chromaticity diagram of the CIE 1931 color space obtained from the reflection spectrum, x = 0.23, y = 0.19.

[0126] Comparative Example 2 A decorative film was produced in the same manner as in Example 1, except that the diameter of the dots in the optical mask layer was changed to 200 μm so that adjacent dots overlapped, and measurements were carried out in the same manner as in Example 1. The results are shown in Table 1. The dots on the mask used in Comparative Example 2 were arranged as shown in FIG. 6, taking the five dots in the upper left corner of the mask in FIG. 5 as an example.

[0127] [Comparative Example 3] Exposure amount: 60 mJ / cm ２ A decorative film was produced in the same manner as in Example 4, except for changing the temperature and humidity, and measurements were carried out in the same manner as in Example 1. The results are shown in Table 1.

[0128] [Comparative Example 4] Exposure amount: 100 mJ / cm ２ A decorative film was produced in the same manner as in Example 1, except for changing the temperature and humidity, and measurements were carried out in the same manner as in Example 1. The results are shown in Table 1.

[0129] Comparative Example 5 A decorative film was produced in the same manner as in Example 1, and measurements were carried out in the same manner as in Example 1, except that the distance between the halftone dots of the optical mask layer was changed to a halftone dot size of 200 μm, and the distance between the positions where the adjacent helical pitches showed their maximum values ​​was adjusted to 400 μm. The results are shown in Table 1.

[0130] Table 1 is shown below. In Table 1, "printed dot size" and "dot spacing" represent the "printed dot spacing (μm)" and "dot spacing (μm)" in both the R and C directions of the optical film layer. The printed dot size indicates the diameter. In Table 1, the "maximum value (nm)," "minimum value (nm)," and "difference between the maximum and minimum values ​​(nm)" in the "cholesteric liquid crystal phase helical pitch" column represent the measurement results for each test piece prepared by cutting out the decorative film in the directions corresponding to the R and C directions of the optical mask layer (see FIG. 5) placed during the preparation of the decorative film. In other words, taking Example 1 as an example, this means that in both the cross sections along the R direction and the C direction of the optical mask layer (see FIG. 5 ) placed during the production of the decorative film, the minimum value of the helical pitch was 230 nm, the maximum value of the helical pitch was 480 nm, and the difference between the maximum and minimum values ​​of the helical pitch was 250 nm. Note that the directions corresponding to the R direction and the C direction of the optical mask layer (see FIG. 5 ) placed during the production of the decorative film respectively coincide with the X direction and the Y direction in the in-plane schematic diagram of the cholesteric liquid phase layer shown in FIG.

[0131] Further, for the decorative films obtained in each example, test pieces were prepared cut at an angle of 45° to the C direction with respect to the R direction of the optical mask layer (see FIG. 5) placed during the production of the decorative film, and in the direction in which the dots are arranged (hereinafter also referred to as the "ZR direction") and in the direction perpendicular thereto (hereinafter also referred to as the "ZC direction"), and the evaluation was carried out using the same procedure as in Example 1. As a result, in the SEM image observation of each test piece cut along the above-mentioned ZX direction and ZY direction, a striped pattern in which bright lines and dark lines derived from the cholesteric liquid crystal phase are alternately arranged in the thickness direction was observed, and the observed striped pattern had a periodic wave-like structure with amplitude in the thickness direction, and it was confirmed that the spacing between the bright lines was larger at positions where the wave amplitude was larger, and the spacing between the bright lines was smaller at positions where the wave amplitude was smaller. Furthermore, in the SEM image observation of each test piece cut out along the ZX direction and the ZY direction, it was confirmed that the size of the helical pitch changed continuously and that maximum and minimum values ​​of the helical pitch appeared alternately. However, since the maximum value of the helical pitch was small, it was confirmed that the difference between the maximum and minimum values ​​was less than 100 nm.

[0132]

[0133] From the results in the table, it is clear that the cholesteric liquid crystal layer of the decorative film of the example can reproduce the colors in the area surrounded by x = 0.26 to 0.40 and y = 0.28 to 0.40 in the xy chromaticity diagram of the CIE 1931 color space without any sense of graininess.

[0134] Furthermore, a comparison of Examples 1, 3, and 4 confirmed that when the size of the mask dots (non-apertures) is small, light from the exposure light source is likely to strike not only from the front but also from oblique directions when the film is transported and exposed, which increases the amount of exposure per area in the exposed portion and tends to increase the maximum value of the helical pitch. Also, a comparison of Examples 4 and 6 confirmed that when the distance between the mask dots (non-apertures) is greater, light from the exposure light source is likely to strike not only from the front but also from oblique directions when the film is transported and exposed, which increases the amount of exposure per area in the exposed portion and tends to increase the maximum value of the helical pitch.

[0135] REFERENCE SIGNS LIST 1 Decorative film 10 Substrate 12 Cholesteric liquid crystal layer 14 Region 22 Pattern mask 24 Halftone dot A Position where the helical pitch is maximum (maximum position) B Position where the helical pitch is minimum (minimum position) LC Liquid crystal compound

Claims

1. A substrate; A decorative film having a cholesteric liquid crystal layer, the cholesteric liquid crystal layer has regions in which the pitch of the helical structure of the liquid crystal compound is different in the plane, the size of the pitch changes continuously in one direction in the plane, and maximum and minimum values ​​of the pitch appear alternately, the maximum value being in a range of 350 to 600 nm, and the minimum value being in a range of 150 to 300 nm; the size of the pitch changes continuously in a direction perpendicular to the one direction, and maximum and minimum values ​​of the pitch appear alternately, the maximum value being in a range of 350 to 600 nm, and the minimum value being in a range of 150 to 300 nm; the distance between adjacent positions showing the maximum value in the one direction is 100 to 300 μm; the distance between adjacent positions showing the maximum value in a direction perpendicular to the one direction is 100 to 300 μm; a position showing a maximum value of the pitch is defined as a first position, and a position showing a minimum value of the pitch adjacent to the first position in the one direction is defined as a second position, the difference between the maximum value of the pitch at the first position and the minimum value of the pitch at the second position is 100 nm or more, A decorative film in which, when a position showing the maximum value of the pitch is defined as a first position and a position showing the minimum value of the pitch adjacent to the first position in a direction perpendicular to the one direction is defined as a third position, the difference between the maximum value of the pitch at the first position and the minimum value of the pitch at the third position is 100 nm or more.

2. The decorative film according to claim 1 , wherein the half width in the reflection wavelength band of the cholesteric liquid crystal layer is 150 nm or more.

3. A display device comprising: a display element; and the decorative film according to claim 1 or 2, which is disposed on one surface of the display element.

4. The display device according to claim 3 , wherein the light emitted from the display element is linearly polarized light.

5. The display device according to claim 3 , wherein the display element is a liquid crystal display device or an electroluminescence display device.

6. An interior trim for an automobile, comprising the decorative film according to claim 1 or 2.

7. An interior decoration for an automobile, comprising the display device according to claim 3.

8. A method for manufacturing the decorative film according to claim 1, A method for manufacturing a decorative film, comprising at least steps X, Y, and Z. Step X: A step of contacting a substrate with a composition containing a liquid crystal compound and a chiral agent to form a composition layer on the substrate in which the liquid crystal compound is oriented and in a cholesteric liquid crystal phase state. Step Y: A step of exposing the composition layer through an AM screen mask to change the helical twisting power of the chiral agent. Step Z: A step of subjecting the composition layer that has been subjected to step Y to a curing treatment to fix the state of the cholesteric liquid crystal phase.