Decorative film, decorative molded body, decorative panel, and electronic device
By designing a combination of a convex structure with a specific inclination angle on the decorative film and a liquid crystal layer, the problem of insufficient color changes in the decorative material is solved, and a rich viewing angle-dependent color effect and functional improvement are achieved.
Patent Information
- Application Number
- JP2022540072
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Priority Date
- 2020-12-24
- Filing Date
- 2021-06-24
- Publication Date
- 2025-02-12
- Estimated Expiration
- 2041-06-24
AI Technical Summary
The prior art is difficult to achieve rich color changes in decorative materials from different perspectives, and traditional decorative methods have shortcomings in functionality and environmental protection.
A decorative film with a reflective layer with a raised structure is adopted to control the inclination angle and distribution of the raised structure to achieve changes in color at different perspectives, combining the selective reflection and optical interference effects of the liquid crystal layer.
It realizes rich color changes in decorative materials from different perspectives, enhances the visual impact of the design, and improves functionality and environmental protection.
Smart Images

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Abstract
Description
[Technical field]
[0001] The present disclosure relates to a decorative film, a decorated molded body, a decorated panel, and an electronic device. [Background technology]
[0002] A decorated molded body is known in which a decorative film is placed on the surface of a resin molded body to color the surface of the resin molded body in a desired hue or to provide a desired pattern on the surface of the resin molded body. The decorated molded body is obtained, for example, by placing a decorative film in a mold in advance and then injection molding a base resin into the mold, and has a structure in which the decorative film is integrated with the surface of the resin molded body. The process of placing a decorative film in a mold in advance and then injection molding the base resin is generally referred to as film insert molding or simply insert molding. The decorated molded body may also be manufactured by attaching a decorative film to the molded body after molding.
[0003] As a conventional hot stamp foil, JP 2001-105795 A describes a hot stamp foil characterized in that a cholesteric liquid crystal polymer layer having a selective reflection wavelength range in visible light is laminated as a transfer layer. In addition, JP 2017-97114 A describes improving retroreflectivity by subjecting the cholesteric liquid crystal layer to uneven processing. Summary of the Invention [Problem to be solved by the invention]
[0004] An object of the present invention is to provide a decorative film that exhibits a wide range of color variations depending on the viewing direction. A problem to be solved by another embodiment of the present disclosure is to provide a decorated molded body including the above decorative film, or a decorated panel including the above decorative film. Another problem to be solved by another embodiment of the present disclosure is to provide an electronic device including the above-mentioned decorative panel. [Means for solving the problem]
[0005] The present disclosure includes the following aspects. <1> The decorative film has a substrate and a reflective layer having a convex structure, and in a cross section obtained by cutting the convex structure in a direction perpendicular to the surface direction of the decorative film, the average positive inclination angle Φ AVE The direction in which the angle is the largest is taken as the first direction, and the average positive tilt angle Φ AVE When the direction in which is the smallest is defined as the second direction, Φ AVE is 3° or more, and Φ in the second direction AVE A decorative film having an area A where the angle is smaller than 3°. <2> The area A in the surface direction of the decorative film includes an area having a size equal to or larger than a circle having a radius of 150 μm. <1> The decorative film according to claim 1. <3> The region B has a different second direction from the region A in the plane. <1> or <2> The decorative film according to claim 1. <4> The distance between the region A and the region B in the surface direction of the decorative film is 1 mm or less. <3> The decorative film according to claim 1. <5> In a cross-sectional shape obtained by cutting the convex structure in the region A in a direction perpendicular to the surface direction of the decorative film and in the first direction, a middle height point H between the maximum point and the minimum point of the positive inclination angle 1 / 2 The inclination angle Φ 1 / 2 is greater than or equal to 3° and less than 60° <1> ~ <4> 13. The decorative film according to claim 12 . <6> In a cross-sectional shape obtained by cutting the convex structure in the region A in a direction perpendicular to the surface direction of the decorative film and in the first direction, a middle height point H between the maximum point and the minimum point of the positive inclination angle 1 / 2 The inclination angle Φ 1 / 2 is 60° or more, <1> ~ <4> 13. The decorative film according to claim 12 . <7> In a cross-sectional shape obtained by cutting the convex structure in the region A in a direction perpendicular to the surface direction of the decorative film and in the first direction, the area ratio of a region having an inclination angle Φ of 0° or more and less than 3° is 50% or less with respect to the total area of the region A. <1> ~ <6> 13. The decorative film according to claim 12 . <8> In a cross-sectional shape obtained by cutting the convex structure in the region A in a direction perpendicular to the surface direction of the decorative film and in the first direction, the area ratio of a region having an inclination angle Φ of 3° or more and less than 45° is 40% or more of the total area of the region A. <1> ~ <7> 13. The decorative film according to claim 12 . <9> In a cross-sectional shape obtained by cutting the convex structure in the region A in a direction perpendicular to the surface direction of the decorative film and in the first direction, the area ratio of a region having an inclination angle Φ of 3° or more and less than 7° is 40% or more. <1> ~ <8> 13. The decorative film according to claim 12 . <10> In a cross-sectional shape obtained by cutting the convex structure in the region A in a direction perpendicular to the surface direction of the decorative film and in the first direction, the distance between the minimum points of the positive inclination angle is less than 100 μm. <1> ~ <9> 13. The decorative film according to claim 12 . <11> In a cross-sectional shape obtained by cutting the convex structure in the region A in a direction perpendicular to the surface direction of the decorative film and in the first direction, the distance between the minimum points of the positive inclination angle is 10 μm or more. <1> ~ <10> 13. The decorative film according to claim 12 . <12> The reflective layer contains liquid crystal in a cholesteric alignment state. <1> ~ <11> 13. The decorative film according to claim 12 . <13> The convex structure is a linear convex structure. <1> ~ <12> 13. The decorative film according to claim 12 . <14> The linear convex structure includes a linear convex structure having a ratio L / W of the length L to the average line width W of 5 or more. <1> ~ <13> 13. The decorative film according to claim 12 . <15> <1> ~ <14> A decorated molded body comprising the decorative film according to any one of claims 1 to 5 or a molded product thereof. <16> <1> ~ <14> A decorative panel comprising the decorative film or a molded product thereof according to any one of the above items. <17> <16> An electronic device comprising the decorative panel according to claim 1.
[0006] <a1>A substrate; A reflective layer having a plurality of linear convex structures, The shape of the linear convex structure is 1) The ratio (L / W) of length (L) to average line width (W) is 5 or more, 2) A decorative film having at least a region where the angle formed in the length (L) direction within a single linear convex structure is 45° or more. <a2>A substrate; A reflective layer having a plurality of linear convex structures, The shape of the linear convex structure is 1) The ratio (L / W) of length (L) to average line width (W) is 5 or more, 2) A decorative film having at least an area within the plane where the angle between adjacent linear convex structures in the length (L) direction is 45° or more. <a3>A substrate; A reflective layer having a plurality of linear convex structures, The shape of the linear convex structure is 1) The ratio (L / W) of length (L) to average line width (W) is 5 or more, 2) A decorative film including an area in which the relationship between the average line width Wa = (W1 + W2) / 2 of adjacent convex structures and the distance (D) between the vertices of the convex structures is D > 1.5Wa. <a4>A substrate; A reflective layer having a plurality of linear convex structures, The shape of the linear convex structure is 1) The ratio (L / W) of length (L) to average line width (W) is 5 or more, 2) A decorative film in which the inclination of the cross-sectional shape at the midpoint between the maximum point and the minimum point of the convex structure is 60° or more. <a5>The reflective layer is a layer containing a cholesteric liquid crystal. <a1> ~ <a4>13. The decorative film according to claim 12 . <a6> <a1> ~ <a5>A decorated molded body comprising the decorative film according to any one of the above items. <a7> <a1> ~ <a5>A decorative panel comprising the decorative molded body according to any one of the above. <a8> <a7>An electronic device comprising the decorative panel according to claim 1. Effect of the Invention
[0007] According to one embodiment of the present disclosure, it is possible to provide a decorative film that exhibits a wide range of color variations depending on the viewing direction. According to another embodiment of the present disclosure, a decorated molded body including the above decorative film or a decorated panel including the above decorative film can be provided. According to another embodiment of the present disclosure, there is provided an electronic device including the above-described decorative panel. [Brief description of the drawings]
[0008] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of a decorative film according to the present disclosure. [Diagram 2] FIG. 2 is a schematic cross-sectional view showing an example of a decorative film according to the present disclosure. [Diagram 3] FIG. 3 is a schematic cross-sectional view showing an example of a decorated molded body according to the present disclosure. [Figure 4] FIG. 4 is a schematic cross-sectional view showing an example of a decorated molded body according to the present disclosure. [Diagram 5] FIG. 5 is a schematic cross-sectional view showing an example of a decorated molded body according to the present disclosure. [Figure 6] FIG. 6 is a schematic cross-sectional view showing an example of a decorative panel according to the present disclosure. [Figure 7] 7(a) to (c) are schematic diagrams showing an example of the convex substrate pattern (A). [Figure 8] 8(a) to (e) are schematic diagrams showing examples of the convex substrate pattern (B). [Figure 9] FIG. 9 is a schematic diagram showing an example of an optical mask pattern. [Figure 10] FIG. 10 is a schematic cross-sectional view showing an example of a decorative panel for a display according to the present disclosure. [Figure 11] FIG. 11 is an enlarged schematic view of an area having a convex structure of a reflective layer in an example of a decorative film according to the present disclosure. [Figure 12] 12(a) to 12(c) are schematic cross-sectional views of directions A to C in FIG. 11 and schematic diagrams showing the inclination angle Φ. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0009] The decorative film according to the present disclosure will be described below. However, the present disclosure is not limited to the following embodiments, and can be modified as appropriate within the scope of the purpose of the present disclosure. When describing the embodiments of the present disclosure with reference to the drawings, the description of overlapping components and symbols may be omitted. Components indicated by the same symbols in the drawings are the same components. The dimensional ratios in the drawings do not necessarily represent the actual dimensional ratios.
[0010] In the present disclosure, when a group (atomic group) is represented without indicating whether it is substituted or unsubstituted, it includes both those that have no substituent and those that have a substituent. For example, an "alkyl group" includes not only an alkyl group that has no substituent (an unsubstituted alkyl group) but also an alkyl group that has a substituent (a substituted alkyl group). In the present disclosure, "light" means actinic rays or radiation. In the present disclosure, "actinic rays" or "radiation" refers to, for example, the emission line spectrum of a mercury lamp, far ultraviolet light represented by an excimer laser, extreme ultraviolet light (EUV light: Extreme Ultraviolet), X-rays, and electron beams (EB). Unless otherwise specified, "exposure" in this disclosure includes not only exposure to the emission line spectrum of a mercury lamp, far ultraviolet light represented by an excimer laser, extreme ultraviolet light, X-rays, EUV light, and the like, but also exposure to particle beams such as electron beams and ion beams. In this disclosure, the symbol "to" is used to mean that the numerical values before and after it are included as the lower limit and upper limit.
[0011] In this disclosure, (meth)acrylate refers to acrylate and methacrylate, and (meth)acrylic refers to acrylic and methacrylic. In the present disclosure, the weight average molecular weight (Mw) of the resin component, the number average molecular weight (Mn) of the resin component, and the dispersity (also referred to as molecular weight distribution) (Mw / Mn) of the resin component are defined as polystyrene-equivalent values measured using a Gel Permeation Chromatography (GPC) device (HLC-8120GPC manufactured by Tosoh Corporation) (solvent: tetrahydrofuran, flow rate (sample injection amount): 10 μL, column: TSK gel Multipore HXL-M manufactured by Tosoh Corporation, column temperature: 40° C., flow rate: 1.0 mL / min, detector: refractive index detector).
[0012] In the present disclosure, when a plurality of substances corresponding to each component are present in the composition, the amount of each component in the composition means the total amount of the corresponding substances present in the composition, unless otherwise specified. In the present disclosure, the term "process" includes not only an independent process but also a process that cannot be clearly distinguished from other processes as long as the intended purpose of the process is achieved. In the present disclosure, the term "total solid content" refers to the total mass of the components excluding the solvent from the entire composition of the composition. Also, the term "solid content" refers to the components excluding the solvent from the entire composition of the composition, and may be, for example, solid or liquid at 25°C. In the present disclosure, "mass %" and "weight %" are synonymous, and "parts by mass" and "parts by weight" are synonymous. Also, in the present disclosure, combinations of two or more preferred aspects are more preferred aspects.
[0013] (Decorative film) The decorative film according to the present disclosure has a substrate and an optical thin film that develops color by optical interference or structural color. Specifically, the decorative film according to the present disclosure has a substrate and a reflective layer having a convex structure, and in a cross section obtained by cutting the convex structure in a direction perpendicular to the surface direction of the decorative film, the average positive inclination angle Φ AVE The direction in which the angle is the largest is taken as the first direction, and the average positive tilt angle Φ AVE When the direction in which is the smallest is defined as the second direction, Φ AVE is 3° or more, and Φ in the second direction AVE has an area A smaller than 3°.
[0014] The use of the decorative film according to the present disclosure is not particularly limited, and can be used, for example, to decorate electronic devices (e.g., wearable devices and smartphones), home appliances, audio products, computers, displays, in-vehicle products, watches, accessories, optical components, doors, window glass, and building materials. In particular, the decorative film according to the present disclosure can be suitably used to decorate electronic devices (e.g., wearable devices and smartphones). In addition, the decorative film according to the present disclosure has excellent three-dimensional moldability, and is therefore suitable as a decorative film for molding used in molding such as three-dimensional molding and insert molding, and is more suitable as a decorative film for three-dimensional molding.
[0015] Conventionally, for example, printing, painting, deposition, or plating has been used for surface decoration used in items such as home appliances, electronic devices, and mobile phones. However, for example, from the perspective of functionality, environmental load, and reupholstery, decoration techniques using decorative films have become more widely used. On the other hand, new designs are required due to the spread of user preferences. In particular, changes in color (e.g., color and fine shades) depending on the viewing angle are one of the designs that are required, and the introduction of decoration techniques to obtain such designs has been required. In addition, JP 2001-105795 A describes a hot stamp foil in which a cholesteric liquid crystal polymer layer is laminated as a transfer layer, but since the reflected color changes depending on the viewing angle, a uniform color could not be obtained. In addition, JP 2017-97114 A describes improving retroreflectivity by applying uneven processing to the cholesteric liquid crystal layer, but does not mention its use as a decorative film and its effects.
[0016] As a result of intensive research by the present inventors, it was found that a decorative film including the above-mentioned configuration can provide a decorative film useful as a material for a decorated molded body that has a rich color change depending on the viewing direction. In this disclosure, "rich in color change depending on the viewing direction" means, for example, that there is a large change in color when the object is viewed from an angle perpendicular to the surface direction of the object and when the object is viewed from an angle of 45° to the surface direction of the object. The above-mentioned effect is preferable in that it can improve the impact of the design.
[0017] The decorative film according to the present disclosure will be described in detail below.
[0018] <Base material> The decorative film according to the present disclosure has a substrate. The substrate may be a support. As the substrate, for example, a substrate conventionally known as a substrate used for molding such as three-dimensional molding and insert molding can be used without particular limitation, and may be appropriately selected according to suitability for molding. In addition, the shape and material of the substrate are not particularly limited, and may be appropriately selected as desired. From the viewpoint of ease of molding and chipping resistance, the substrate is preferably a resin substrate, more preferably a resin film.
[0019] Specific examples of the substrate include resin films containing resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), acrylic resin, urethane resin, urethane-acrylic resin, polycarbonate (PC), acrylic-polycarbonate resin, triacetyl cellulose (TAC), cycloolefin polymer (COP), and acrylonitrile / butadiene / styrene copolymer resin (ABS resin). Among these, the substrate is preferably polyethylene terephthalate (PET), acrylic resin, polycarbonate, or polypropylene from the viewpoint of moldability and strength, and more preferably polyethylene terephthalate (PET), acrylic resin, or polycarbonate. The substrate may also be a laminated resin substrate of two or more layers. For example, a laminated film containing an acrylic resin layer and a polycarbonate layer is preferably used.
[0020] The substrate may contain additives as necessary. Examples of such additives include lubricants (e.g., mineral oil, hydrocarbons, fatty acids, alcohols, fatty acid esters, fatty acid amides, metal soaps, natural waxes, and silicones), inorganic flame retardants (e.g., magnesium hydroxide and aluminum hydroxide), halogen-based organic flame retardants, phosphorus-based organic flame retardants, organic or inorganic fillers (e.g., metal powder, talc, calcium carbonate, potassium titanate, glass fiber, carbon fiber, and wood powder), antioxidants, ultraviolet inhibitors, lubricants, dispersants, coupling agents, foaming agents, colorants, and engineering plastics other than the above-mentioned resins. Examples of engineering plastics include polyolefins, polyesters, polyacetals, polyamides, and polyphenylene ethers.
[0021] The substrate may be a commercially available product. Examples of commercially available products include Technoloy (registered trademark) series (acrylic resin film or acrylic resin / polycarbonate resin laminated film, manufactured by Sumitomo Chemical Co., Ltd.), ABS film (manufactured by Okamoto Corporation), ABS sheet (manufactured by Sekisui Seikei Kogyo Co., Ltd.), Teflex (registered trademark) series (PET film, manufactured by Teijin Film Solutions Co., Ltd.), Lumirror (registered trademark) easy moldable type (PET film, manufactured by Toray Industries, Inc.), and Pure Thermo (polypropylene film, manufactured by Idemitsu Unitech Co., Ltd.).
[0022] The thickness of the substrate is determined according to, for example, the use and handling of the molded product to be produced, and is not particularly limited.The lower limit of the thickness of the substrate is preferably 1 μm or more, more preferably 10 μm or more, even more preferably 20 μm or more, and particularly preferably 30 μm or more.The upper limit of the thickness of the substrate is preferably 500 μm or less, more preferably 200 μm or less, and particularly preferably 100 μm or less.
[0023] <Reflection layer> The decorative film according to the present disclosure has a reflective layer having a convex structure, and in a cross section obtained by cutting the convex structure in a direction perpendicular to the surface direction of the decorative film, the average positive inclination angle Φ AVE The direction in which the angle is the largest is taken as the first direction, and the average positive tilt angle Φ AVE When the direction in which is the smallest is defined as the second direction, Φ AVE is 3° or more, and Φ in the second direction AVE has an area A smaller than 3°.
[0024] A method for determining the first direction and the second direction in the present disclosure will be described below. The above-mentioned convex structure is cut in any plane perpendicular to the surface direction of the decorative film (i.e., there are 360° in the direction), and the average positive inclination angle Φ AVE The direction in which the maximum value is reached and the average positive tilt angle Φ AVE Find the direction in which is the smallest. Mean positive slope angle Φ AVE The method of calculating the average positive inclination angle Φ is as follows: for an area including the above-mentioned convex structure and having a size equal to or larger than a circle with a radius of 150 μm, the above-mentioned convex structure is cut in one direction, and the inclination angle of the convex structure portion in the cross section of the cut surface is averaged only for the parts of the cross section that are 0° or more. AVE Note that the part with a negative inclination angle is the average of the positive inclination angles Φ AVE are excluded from the calculation. In addition, the above-mentioned positive inclination angle is an angle with respect to the surface direction of the decorative film, and the portion greater than 90° and less than 180° is considered to be an inclination angle in the opposite direction to the measurement direction of the above-mentioned positive inclination angle, and the portion less than 90° and exceeding 0° is considered to be a negative inclination angle. Mean positive slope angle Φ AVE Specifically, the decorative film is cut using a microtome (e.g., RX-860, manufactured by Yamato Koki Kogyo Co., Ltd.) in any plane (360° in total) perpendicular to the surface direction of the decorative film. The cutting direction can be predicted to some extent by observing the surface of the decorative film using a microscope (e.g., BX53M, manufactured by Olympus Corporation). The cut cross section is observed using a scanning electron microscope (e.g., SU3800, manufactured by Hitachi High-Technologies Corporation) to measure the cross-sectional shape, and Φ is calculated as described above. AV E Calculate. Other methods for measuring the cross-sectional shape include a method for measuring the surface shape of the convex structure using a laser microscope (e.g., VK-X1000 manufactured by Keyence Corporation). In addition, when the convex structure can be measured three-dimensionally, the cross-sectional shape may be calculated from the three-dimensional shape.
[0025] A more specific explanation will be given with reference to FIG. 11 and FIG. FIG. 11 is an enlarged schematic view of an area having a convex structure of a reflective layer in an example of a decorative film according to the present disclosure. The convex structure of the reflective layer in FIG. 11 is formed of a plurality of linear convex structures whose longitudinal direction is the vertical direction in FIG. Straight lines A, B, and C in Fig. 11 respectively indicate the directions in which the convex structure is cut. Cross sections of the convex structure cut in the direction indicated by line A (direction A), the direction indicated by line B (direction B), or the direction indicated by line C (direction C) are shown in Fig. 12. In Fig. 12, (a) shows a cross section of the convex structure cut in direction A, (b) shows a cross section of the convex structure cut in direction B, and (c) shows a cross section of the convex structure cut in direction C. As shown in Fig. 12(a), the cross section of the convex structure in direction A has inclination angles Φ of 30° and -20°. The bar indicated by a1 shows the distribution of positive inclination angles, and the bar indicated by a2 shows the distribution of negative inclination angles. In direction A, the average positive inclination angle Φ AVE The result is 30°. As mentioned above, the negative tilt angle of -20° is excluded from the calculation. 12(b), the cross section of the convex structure in direction B has inclination angles Φ of 20° and −10°. The bar indicated by b1 shows the distribution of positive inclination angles, and the bar indicated by b2 shows the distribution of negative inclination angles. In direction B, the average positive inclination angle Φ AVE The result is 20°. As mentioned above, the negative tilt angle of -10° is excluded from the calculation. Furthermore, as shown in FIG. 12(c), the cross section of the convex structure in direction C is flat, and the inclination angle Φ is 0°. In direction C, the average positive inclination angle Φ AVE When we solve this, the result is 0°. The same operation is performed over 360° (if the first and second directions are predictable to some extent, this can be omitted), and the average positive tilt angle Φ AVE The first direction is the direction in which the mean positive tilt angle Φ AVE The second direction is found to be the direction in which is smallest. In the region having the convex structure shown in FIG. 11 and FIG. 12, Φ AVE is 30°, and Φ in the second direction AVE is 0°.
[0026] In the present disclosure, a convex structure means that a convex undulation is formed with respect to a specific plane. In addition, the decorative film according to the present disclosure only needs to have a convex structure in the reflective layer, and the surface of the decorative film itself may be flat (preferably without a convex structure having a height of 1 μm or more on the surface). The shape of the convex structure is not particularly limited, and may be, for example, a linear structure, a spiral structure, a concentric circular structure, a wavy line structure, or various other shapes. In the present disclosure, the term "linear" means a shape having a length in a specific direction. Specifically, a preferred embodiment of the invention is one in which the ratio (L / W) of the length (L) to the average line width (W) is 5 or more. In addition, the cross-sectional shape of the above-mentioned convex structure is not particularly limited, but for example, the cross-sectional shape in a direction perpendicular to the surface direction of the decorative film and perpendicular to the longitudinal direction of the convex structure may be a triangular shape, a square shape, a rectangular shape, a trapezoidal shape, a semicircular shape, a semi-elliptical shape, or the like. For example, when a decorative film has, on its surface, an area in which a plurality of linear convex structures are arranged, and an area in which a plurality of linear convex structures are arranged in a longitudinal direction different from that of the linear convex structures in the above area, a decorative film having visibility in which one area is bright and the other area is dark depending on the viewing direction can be obtained. Furthermore, for example, when a decorative film has an area with a concentric convex structure on its surface, light and dark areas are generated radially from the center of the concentric circle in the area, and a decorative film having visibility in which the light and dark areas change depending on the viewing direction is obtained.
[0027] For example, the convex structure shown in FIG. 7 or FIG. 8 is preferable. FIG. 7(a) is a schematic diagram showing an example of an area A1 in which a concentric circular convex structure is formed, and shows a pattern area. Fig. 7(b) is a diagram showing the details of region A1 in Fig. 7(a), and Fig. 7(b) is a schematic diagram seen from the side (top) where the convex structure is formed in a direction perpendicular to the surface direction of the decorative film, and the concentric convex structure is formed in a region of 50 mm in diameter. The black line part in Fig. 7(b) shows the linear convex shape, and the same pattern is repeated up to a diameter of 50 mm. FIG. 7(c) is a diagram showing an example of a cross-sectional view taken along line ab shown in FIG. 7(b). 8(a) to 8(e) are schematic diagrams showing an example (area A1) of the region A in which a plurality of linear convex structures are formed. Fig. 8(a) is a schematic diagram seen from the side where the convex structure is formed in the direction perpendicular to the surface direction of the decorative film, and shows an example in which two types of 10mm x 10mm regions (region A2 and region B2) in which a convex structure is formed with multiple linear convex structures with different longitudinal directions are laid out in a size of 50mm x 50mm in the surface direction. In Fig. 8(a), region A2 is indicated as A2, and region B2 is indicated as B2. FIG. 8(b) shows a detail of area A2, where the same pattern is repeated down to 10 mm×10 mm. FIG. 8(c) is a diagram showing an example of a cross-sectional view taken along line cd in FIG. 8(b). FIG. 8(d) shows a detail of area B2, where the same pattern is repeated down to 10 mm×10 mm. FIG. 8(e) is a diagram showing an example of a cross-sectional view between ef in FIG. 8(d).
[0028] The convex structure preferably has a periodic pitch. The pitch is the interval between adjacent convex portions in the convex structure. The interval between convex portions is the distance between the highest points of the convex portions. For example, if the convex structure is hemispherical, the pitch corresponds to the distance between the apexes of the two nearest hemispherical convex portions. For example, if the convex structure is triangular, the pitch corresponds to the distance between the apexes of the two nearest triangular convex portions. Furthermore, when the convex structure has a hemispherical shape, the inclination angle at a certain point of the convex structure portion in the cross section is the inclination angle of the tangent at the above-mentioned point.
[0029] From the viewpoints of obtaining visibility with rich color changes depending on the viewing angle and of brilliance, the height (H) of the convex structure is preferably 1 μm or more, more preferably 1 μm to 100 μm, even more preferably 2 μm to 30 μm, particularly preferably 3 μm to 20 μm, and most preferably 4 μm to 10 μm. In the present disclosure, the in-plane average value of the height difference between adjacent maximum and minimum parts of the convex surface obtained using a laser microscope (e.g., VK-X1000 manufactured by Keyence Corporation) is adopted as the height of the convex structure. The surface to be measured is the exposed surface of the convex structure of the reflective layer (i.e., the convex surface). However, when the layer covering the reflective layer has a convex structure and the convex structure of the layer covering the reflective layer can be considered to be substantially the same as the convex structure of the reflective layer, the height of the convex structure of the layer covering the reflective layer may be adopted as the height of the convex structure of the reflective layer.
[0030] From the viewpoints of obtaining visibility with rich color changes depending on the viewing angle and of brilliance, the width (W) of the convex structure is preferably 1 μm or more, more preferably 2 μm to 200 μm, even more preferably 30 μm to 100 μm, and particularly preferably 4 μm to 40 μm. In the present disclosure, the in-plane average value of the distance between the minimum parts of the convex parts obtained using a laser microscope (e.g., VK-X1000 manufactured by Keyence Corporation) is adopted as the width of the convex structure. The surface to be measured is the exposed surface of the convex structure of the reflective layer (i.e., the convex surface). However, when the layer covering the reflective layer has a convex structure and the convex structure of the layer covering the reflective layer can be considered to be substantially the same as the convex structure of the reflective layer, the width of the convex structure of the layer covering the reflective layer may be adopted as the width of the convex structure of the reflective layer.
[0031] The length (L) of the convex structure is not particularly limited and can be appropriately selected as desired. From the viewpoints of obtaining visibility with rich color changes depending on the viewing angle and of brilliance, the length (L) is preferably 5 μm or more, more preferably 10 μm to 100 m, even more preferably 30 μm to 20 m, and particularly preferably 50 μm to 10 m. In the present disclosure, the length (L) of the linear convex structure can be measured by observation using a laser microscope (e.g., VK-X1000 manufactured by Keyence Corporation). The surface to be measured is the exposed surface of the convex structure of the reflective layer (i.e., the convex surface). However, when the layer covering the reflective layer has a convex structure and the convex structure of the layer covering the reflective layer can be considered to be substantially the same as the convex structure of the reflective layer, the width of the convex structure of the layer covering the reflective layer may be adopted as the width of the convex structure of the reflective layer.
[0032] The ratio of the width of the convex structure to the height of the convex structure (width:height) is preferably 20:1 to 1:2, more preferably 10:1 to 1:0.8, even more preferably 8:1 to 1:1, and particularly preferably 4:1 to 1:1.2, from the viewpoints of obtaining visibility with rich color changes depending on the viewing angle and of brilliance.
[0033] Reflective layer thickness H T The height H of the convex structure of the reflective layer D The ratio of D / H T >0.1, 0.5 <H D / H T <200, preferably 1 <H D / H T <100 is more preferable, 5 <H D / H T It is especially preferred that it is <50. The thickness of the reflective layer refers to the distance between the upper and lower surfaces of the reflective layer.
[0034] When the decorative film according to the present disclosure has a linear convex structure, the ratio (L / W) of the length (L) of the linear convex structure to the average line width (W) is preferably 5 or more, more preferably 8 or more, even more preferably 10 or more, and particularly preferably 20 or more. By adjusting the ratio within the above range, high glitteriness and visibility with rich color change depending on the viewing angle can be obtained.
[0035] When the decorative film according to the present disclosure has a linear convex structure, it is preferable that the angle formed by the length (L) in the in-plane direction in a single linear convex shape is at least 45°, more preferably at least 60°, even more preferably at least 70°, and particularly preferably at least 90°. The above range provides high glitter and visibility with rich color change depending on the viewing angle. Here, adjacent convex shapes in a single linear convex shape whose angle formed by the length (L) in the in-plane direction within the line width (W) is less than 20° are considered to be within the range of a single convex shape.
[0036] When the decorative film according to the present disclosure has a linear convex structure, it is preferable that the angle between adjacent linear convex structures in the length (L) direction is at least 45° in the plane, more preferably at least 60° in the plane, even more preferably at least 70° in the plane, and particularly preferably at least 80° in the plane. The above range provides high glitter and visibility with rich color change depending on the viewing angle. Here, adjacent means that the linear convex structures are adjacent to each other at a distance of 10 times or less than the average value Wa=(W1+W2) / 2 of the line widths (W1 and W2) of adjacent linear convex shapes.
[0037] When the decorative film according to the present disclosure has a linear convex structure, the relationship between the distance (D) between the vertices of adjacent convex structures and the average line width Wa=(W1+W2) / 2 of the adjacent convex structures preferably includes a region where D>1.5Wa, more preferably includes a region where 1.75Wa≦D≦10Wa, even more preferably includes a region where 1.8Wa≦D≦8Wa, and particularly preferably includes a region where 2DWa≦D≦6Wa. The above ranges provide high glitter and visibility with rich color changes depending on the viewing angle.
[0038] When the decorative film according to the present disclosure has a linear convex structure, the region A is an intermediate height point (H 1 / 2 ) preferably includes a convex structure having an inclination angle Φ of 60° or more, more preferably includes a convex structure having an inclination angle Φ of 70° or more, and further preferably includes a convex structure having an inclination angle Φ of 80° or more. By using the above range, high glitteriness and visibility with rich color change depending on the viewing angle can be obtained.
[0039] From the viewpoints of visibility and color change depending on the viewing direction, the region A in the surface direction of the decorative film preferably includes a region having a size equal to or larger than a circle having a radius of 150 μm. The upper limit of the size of the region A is the area of one surface of the decorative film. The decorative film may have two or more regions A in the surface direction, and the size of each region is not particularly limited. They may all be the same size, or two or more regions may be different sizes.
[0040] The decorative film according to the present disclosure may have an area other than the above-mentioned area A in the surface direction of the decorative film, may have an area having one or more types of convex structures different from the above-mentioned area A, or may have an area without a convex structure. In addition, from the viewpoints of brilliance and color change depending on the viewing direction, the decorative film according to the present disclosure preferably further has within its plane a region B whose second direction is different from that of the region A, more preferably further has within its plane a region C whose second direction is different from that of the regions A and B, and even more preferably further has within its plane a region D whose second direction is different from that of the regions A to C. In addition, from the viewpoint of glitter and color change depending on the viewing direction, the above-mentioned regions B to D are set to Φ AVE is 3° or more, and Φ in the second direction AVE It is preferable that the area is smaller than 3°.
[0041] In the decorative film according to the present disclosure, Φ in the first direction including the regions A to D AVE is 3° or more, and Φ in the second direction AVE The total area of the region within the plane of the decorative film that is smaller than 3° is not particularly limited, but from the viewpoints of visibility, opal-like visibility, and color change depending on the viewing direction, it is preferably 10 area% to 100 area%, more preferably 20 area% to 100 area%, even more preferably 30 area% to 100 area%, and particularly preferably 50 area% to 100 area%.
[0042] The distance between the region A and the region B in the surface direction of the decorative film is not particularly limited, but from the viewpoint of making the brilliance and the contrast between the light and dark areas more easily visible, it is preferably 5 mm or less, more preferably 1 mm or less, and particularly preferably 0.5 mm or less. The lower limit of the distance is 0 mm, that is, the region A and the region B may be in contact with each other.
[0043] In a cross-sectional shape obtained by cutting the convex structure in the region A in a direction perpendicular to the surface direction of the decorative film and in the first direction, a middle height point H between the maximum point and the minimum point of the positive inclination angle 1 / 2 The inclination angle Φ 1 / 2 From the viewpoint of brilliance when viewed from the front, for example when viewed on a table or in a displayed state, the angle is preferably 3° or more and less than 60°, more preferably 3° or more and less than 20°, and particularly preferably 3° or more and less than 7°. In addition, regarding the positions of the above-mentioned maximum point and the above-mentioned minimum point, for example, when the above-mentioned cross-sectional shape is a semicircular convex structure, the apex of the semicircular convex structure is the maximum point, and the contact point between the semicircular arc and the diameter is the minimum point. 1 / 2 is a position at half the height of the semicircular convex structure.
[0044] In addition, in a cross-sectional shape obtained by cutting the convex structure in the region A in a direction perpendicular to the surface direction of the decorative film and in the first direction, a middle height point H between the maximum point and the minimum point of the positive inclination angle is 1 / 2 The inclination angle Φ 1 / 2 When viewed from an oblique direction, particularly from an oblique direction of 45° or more from a direction perpendicular to the surface, for example, when an object decorated with the decorative film is held in the hand and tilted to view, from the viewpoint of brilliance, the angle is preferably 60° or more and less than 90°, more preferably 60° or more and less than 75°.
[0045] In a cross-sectional shape obtained by cutting the convex structure in the region A in the direction perpendicular to the surface direction of the decorative film and in the first direction, the area ratio of the region having an inclination angle Φ of 0° or more and less than 3° is preferably 50% or less, more preferably 35% or less, and particularly preferably 25% or less, of the total area of the region A, from the viewpoint of making the dark part in the bright and dark parts darker and enhancing the contrast. The lower limit of the area ratio is 0%.
[0046] Furthermore, in a cross-sectional shape of the convex structure in the region A cut in a direction perpendicular to the surface direction of the decorative film and in the first direction, the area ratio of the region having an inclination angle Φ of 3° or more and less than 45° is, from the viewpoint of making the bright parts in the bright and dark parts brighter and enhancing the contrast, preferably 40% or more, more preferably 50% or more and 90% or less, and particularly preferably 60% or more and 80% or less, of the total area of the region A.
[0047] Furthermore, in the cross-sectional shape of the convex structure in the above-mentioned region A cut in a direction perpendicular to the surface direction of the decorative film and in the above-mentioned first direction, the area ratio of the region where the inclination angle Φ is 3° or more and less than 7° is preferably 20% or more, more preferably 40% or more, and particularly preferably 50% or more and 90% or less, from the viewpoint of brightening the bright parts in the bright and dark parts when viewed from the front and enhancing the contrast.
[0048] In a cross-sectional shape obtained by cutting the convex structure in the above-mentioned region A in a direction perpendicular to the surface direction of the above-mentioned decorative film and in the above-mentioned first direction, the distance between the minimum points of the positive inclination angle is preferably less than 150 μm, more preferably less than 100 μm, and particularly preferably less than 50 μm, from the viewpoint of reducing the visibility of the convex structure and obtaining specular reflectivity.
[0049] Furthermore, in a cross-sectional shape obtained by cutting the convex structure in the above-mentioned region A in a direction perpendicular to the surface direction of the above-mentioned decorative film and in the above-mentioned first direction, the distance between the minimum points of the positive inclination angle is preferably 5 μm or more, more preferably 10 μm or more, and particularly preferably 20 μm or more, from the viewpoint of suppressing the occurrence of rainbow patterns due to interference.
[0050] In addition, in each region such as region A, when a multiple convex structure is present, the distance between the vertices of adjacent convex structures is, independently, preferably 5 μm or more and less than 150 μm, more preferably 10 μm or more and less than 100 μm, and particularly preferably 20 μm or more and less than 50 μm, from the viewpoints of glitter, visibility, color change depending on the viewing direction, and suppressing the occurrence of rainbow patterns due to interference.
[0051] The method of forming the convex structure in the reflective layer is not particularly limited, but for example, a method of preparing a mold in which a shape corresponding to the linear convex structure is formed in advance, transferring the convex shape to a substrate on which a reflective layer without a convex structure is laminated, and a method of transferring the convex shape to a substrate before forming a reflective layer, and then deforming the reflective layer along the convex shape can be preferably mentioned.In either case, a resin layer described later that can easily follow the convex shape can also be provided on the substrate.The transfer method can be, for example, a method of directly pressing the mold onto the substrate, a method of pressing using a roll-type laminator, and a method of pressing using a vacuum laminator. As a method for forming the convex structure in the reflective layer, a method for forming the convex structure by sputtering an inorganic compound such as inorganic particles onto a base material having the convex structure can also be mentioned.
[0052] The reflective layer preferably has a central wavelength of selective reflection in the range of 300 nm or more and 1,500 nm or less. Examples of the reflective layer include a layer containing liquid crystal in a cholesteric orientation state (also simply referred to as a "cholesteric liquid crystal layer"), a layer containing flat metal particles, an optical multilayer film, and a layer containing a chromic material. Among the above-mentioned reflective layers, a cholesteric liquid crystal layer or a layer containing an optical multilayer film is preferred from the viewpoints of glitter and color change depending on the viewing direction, and a cholesteric liquid crystal layer is more preferred from the viewpoint of increasing color change depending on the viewing direction.
[0053] <<Liquid crystal composition>> The cholesteric liquid crystal layer is a layer formed by curing a liquid crystal composition. The liquid crystal composition is a composition containing a liquid crystal compound. As the liquid crystal compound used in the present disclosure, it is preferable to use at least a cholesteric liquid crystal compound having one ethylenically unsaturated group or one cyclic ether group from the viewpoint of molding processability and temporary support peelability. The liquid crystal composition for forming the cholesteric liquid crystal layer contains, for example, a cholesteric liquid crystal compound having one ethylenically unsaturated group or one cyclic ether group in an amount of 25% by mass or more based on the total solid content of the liquid crystal composition, and may further contain other components (for example, a chiral agent, an alignment control agent, a polymerization initiator, and an alignment assistant).
[0054] -Cholesteric liquid crystal compound having one ethylenically unsaturated group or one cyclic ether group- The liquid crystal composition preferably contains, as a liquid crystal compound, 25% by mass or more of a cholesteric liquid crystal compound having one ethylenically unsaturated group or one cyclic ether group (hereinafter also referred to as a "specific liquid crystal compound").
[0055] The ethylenically unsaturated group in the specific liquid crystal compound is not particularly limited, and may be, for example, a (meth)acryloxy group, a (meth)acrylamide group, a vinyl group, a vinyl ester group, or a vinyl ether group. From the viewpoint of reactivity, the ethylenically unsaturated group is preferably a (meth)acryloxy group, a (meth)acrylamide group, or an aromatic vinyl group, more preferably a (meth)acryloxy group or a (meth)acrylamide group, and particularly preferably a (meth)acryloxy group.
[0056] The cyclic ether group in the specific liquid crystal compound is not particularly limited, but from the viewpoint of reactivity, it is preferably an epoxy group or an oxetanyl group, and particularly preferably an oxetanyl group.
[0057] From the viewpoints of reactivity and suppression of changes in reflectance and color after molding, the specific liquid crystal compound is preferably a cholesteric liquid crystal compound having one ethylenically unsaturated group. More preferably, the liquid crystal composition contains 25% by mass or more of the cholesteric liquid crystal compound having one ethylenically unsaturated group based on the total solid content of the liquid crystal composition.
[0058] The specific liquid crystal compound may have both an ethylenically unsaturated group and a cyclic ether group in one molecule, but the number of ethylenically unsaturated groups is one, or the number of cyclic ether groups is one. In addition, as long as the number of ethylenically unsaturated groups in the specific liquid crystal compound is one, for example, the specific liquid crystal compound may be a compound having one ethylenically unsaturated group and one or more cyclic ether groups.
[0059] When the liquid crystal composition contains a cholesteric liquid crystal compound having one ethylenically unsaturated group, the liquid crystal composition preferably contains a radical polymerization initiator, and more preferably contains a photoradical polymerization initiator, from the viewpoint of suppressing changes in reflectance and color after molding.
[0060] When the liquid crystal composition contains a cholesteric liquid crystal compound having one cyclic ether group, from the viewpoint of suppressing changes in reflectance and color tone after molding, the liquid crystal composition preferably contains a cationic polymerization initiator, and more preferably contains a photocationic polymerization initiator.
[0061] From the viewpoint of suppressing changes in reflectance and color after molding, the specific liquid crystal compound is preferably a cholesteric liquid crystal compound having both an ethylenically unsaturated group and a cyclic ether group, and more preferably a cholesteric liquid crystal compound having one ethylenically unsaturated group and one cyclic ether group.
[0062] The specific liquid crystal compound may be a rod-shaped liquid crystal compound or a discotic liquid crystal compound as long as it has a liquid crystal structure. The specific liquid crystal compound is preferably a rod-shaped liquid crystal compound from the viewpoints of ease of adjusting the pitch of the helical structure in the cholesteric liquid crystal layer and suppressing changes in reflectance and color after molding.
[0063] As the rod-shaped liquid crystal compound, azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoates, cyclohexane carboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines, phenyldioxanes, tolanes, or alkenylcyclohexylbenzonitriles are preferably used. In addition to the above-mentioned low molecular weight liquid crystal compounds, liquid crystalline polymer compounds can also be used. As the rod-shaped liquid crystal compound, the following compounds are described in "Makromol. Chem., Vol. 190, p. 2255 (1989)"; "Advanced Materials 5, p. 107 (1993)”, U.S. Pat. No. 4,683,327, U.S. Pat. No. 5,622,648, U.S. Pat. No. 5,770,107, WO 1995 / 022586, WO 1995 / 024455, WO 1997 / 000600, WO 1998 / 023580, WO 1998 / 052905, JP-A-1-272551, JP-A-6-16616, JP-A-7-110469, JP-A-11-80081, and JP-A-2001-328973, compounds having one ethylenically unsaturated group or one cyclic ether group can be used. Furthermore, as the rod-shaped liquid crystal compound, for example, a compound having one ethylenically unsaturated group or one cyclic ether group among the compounds described in JP-A-11-513019 and JP-A-2007-279688 can be preferably used. The cholesteric liquid crystal layer is more preferably a layer in which the orientation of the rod-shaped liquid crystal compound is fixed by polymerization.
[0064] As the discotic liquid crystal compound, for example, among the compounds described in JP-A-2007-108732 or JP-A-2010-244038, a compound having one ethylenically unsaturated group or one cyclic ether group can be preferably used.
[0065] Specific examples of the specific liquid crystal compound include, but are not limited to, the compounds shown below.
[0066] [ka]
[0067] [ka]
[0068] [ka]
[0069] [ka]
[0070] [ka]
[0071] [ka]
[0072] [ka]
[0073] The liquid crystal composition may contain one specific liquid crystal compound alone or two or more specific liquid crystal compounds. The content of the specific liquid crystal compound is preferably 25% by mass or more based on the total solid content of the liquid crystal composition. When the content of the specific liquid crystal compound is 25% by mass or more, a decorative film with small change in reflectance after molding can be obtained. In addition, from the viewpoint of suppressing change in reflectance and change in color after molding, the content of the specific liquid crystal compound is preferably 30% by mass or more based on the total solid content of the liquid crystal composition, more preferably 40% by mass or more, even more preferably 60% by mass or more and 99% by mass or less, and particularly preferably 80% by mass or more and 98% by mass or less.
[0074] -Other cholesteric liquid crystal compounds- The liquid crystal composition may contain other cholesteric liquid crystal compounds (hereinafter, simply referred to as "other liquid crystal compounds") other than the specific liquid crystal compound. Examples of the other liquid crystal compounds include cholesteric liquid crystal compounds having no ethylenically unsaturated group and no cyclic ether group, cholesteric liquid crystal compounds having two or more ethylenically unsaturated groups and no cyclic ether group, cholesteric liquid crystal compounds having two or more cyclic ether groups and no ethylenically unsaturated group, and cholesteric liquid crystal compounds having two or more ethylenically unsaturated groups and two or more cyclic ether groups. From the viewpoint of suppressing changes in reflectance and color after molding, the other liquid crystal compound is preferably at least one compound selected from the group consisting of cholesteric liquid crystal compounds having no ethylenically unsaturated group and no cyclic ether group, cholesteric liquid crystal compounds having two or more ethylenically unsaturated groups and no cyclic ether group, and cholesteric liquid crystal compounds having two or more cyclic ether groups and no ethylenically unsaturated group, more preferably at least one compound selected from the group consisting of cholesteric liquid crystal compounds having no ethylenically unsaturated group and no cyclic ether group, cholesteric liquid crystal compounds having two ethylenically unsaturated groups and no cyclic ether group, and cholesteric liquid crystal compounds having two cyclic ether groups and no ethylenically unsaturated group, and particularly preferably at least one compound selected from the group consisting of cholesteric liquid crystal compounds having no ethylenically unsaturated group and no cyclic ether group, and cholesteric liquid crystal compounds having two ethylenically unsaturated groups and no cyclic ether group.
[0075] As the other liquid crystal compound, a known cholesteric liquid crystal compound can be used. As the rod-shaped liquid crystal compound among the other liquid crystal compounds, for example, those described in "Makromol. Chem., Vol. 190, p. 2255 (1989)" and "Advanced Materials 5, p. 107 (1993)," U.S. Pat. No. 4,683,327, U.S. Pat. No. 5,622,648, U.S. Pat. No. 5,770,107, WO 1995 / 022586, WO 1995 / 024455, WO 1997 / 000600, WO 1998 / 023580, WO 1998 / 052905, JP-A-1-272551, JP-A-6-16616, JP-A-7-110469, JP-A-11-80081, and JP-A-2001-328973 can be used. Furthermore, as the rod-shaped liquid crystal compound in the other liquid crystal compounds, for example, the compounds described in JP-T-11-513019 or JP-A-2007-279688 can be preferably used. As the discotic liquid crystal compound in the other liquid crystal compounds, for example, the compounds described in JP-A-2007-108732 or JP-A-2010-244038 can be preferably used.
[0076] The liquid crystal composition may contain one or more of the other liquid crystal compounds. From the viewpoint of suppressing changes in reflectance and color tone after molding, the content of the other liquid crystal compounds is preferably 70% by mass or less, more preferably 60% by mass or less, even more preferably 40% by mass or less, and particularly preferably 5% by mass or less, based on the total solid content of the liquid crystal composition. The lower limit of the content of the other liquid crystal compounds is 0% by mass.
[0077] -Chiral agents (optically active compounds)- From the viewpoint of ease of forming a cholesteric liquid crystal layer and ease of adjusting the pitch of the helical structure, the liquid crystal composition preferably contains a chiral agent (i.e., an optically active compound). The chiral agent has a function of inducing a helical structure in the cholesteric liquid crystal layer. The chiral agent may be selected according to the purpose, since the twist direction or helical pitch of the helical structure induced by the liquid crystal compound varies. The chiral agent is not particularly limited, and known compounds (for example, compounds described in "Liquid Crystal Device Handbook", Chapter 3, Section 4-3, Chiral Agents for TN (twisted nematic) and STN (Super-twisted nematic), p. 199, edited by the 142nd Committee of the Japan Society for the Promotion of Science, 1989), isosorbide, and isomannide derivatives can be used. The chiral agent generally contains an asymmetric carbon atom, but axially asymmetric compounds or planarly asymmetric compounds that do not contain an asymmetric carbon atom can also be used as the chiral agent. Preferred examples of the axially asymmetric compound or the planarly asymmetric compound include a binaphthyl compound, a helicene compound, and a paracyclophane compound.
[0078] From the viewpoint of suppressing the change in reflectance after molding, the liquid crystal composition preferably contains a chiral agent having a polymerizable group, and more preferably contains a chiral agent containing a polymerizable group and a chiral agent without a polymerizable group. The polymerizable group is not particularly limited as long as it is a polymerizable group, but from the viewpoint of reactivity and suppressing the change in reflectance after molding, it is preferably an ethylenically unsaturated group or a cyclic ether group, and more preferably an ethylenically unsaturated group. The preferred aspects of the ethylenically unsaturated group and the cyclic ether group in the chiral agent are the same as the preferred aspects of the ethylenically unsaturated group and the cyclic ether group in the specific liquid crystal compound described above.
[0079] When the chiral agent has an ethylenically unsaturated group or a cyclic ether group, from the viewpoints of reactivity and suppression of change in reflectance after molding, it is preferable that the ethylenically unsaturated group or cyclic ether group of the specific liquid crystal compound and the ethylenically unsaturated group or cyclic ether group of the chiral agent are the same type of group (for example, an ethylenically unsaturated group, preferably a (meth)acryloxy group), and it is more preferable that they are the same group.
[0080] From the viewpoints of reactivity and suppression of change in reflectance after molding, the chiral agent having a polymerizable group is preferably a chiral agent having two or more polymerizable groups, more preferably a chiral agent having two or more ethylenically unsaturated groups or a chiral agent having two or more cyclic ether groups, and particularly preferably a chiral agent having two or more ethylenically unsaturated groups.
[0081] The chiral agent may be a cholesteric liquid crystal compound.
[0082] As described later, when the magnitude of the helical pitch of the cholesteric liquid crystal layer is controlled by light irradiation during the production of the cholesteric liquid crystal layer, the liquid crystal composition preferably contains a chiral agent (hereinafter also referred to as a "photosensitive chiral agent") that is sensitive to light and can change the helical pitch of the cholesteric liquid crystal layer. The photosensitive chiral agent is a compound that changes its structure by absorbing light and can change the helical pitch of the cholesteric liquid crystal layer. As such a compound, a compound that causes at least one of a photoisomerization reaction, a photodimerization reaction, and a photodecomposition reaction is preferable. A compound that causes a photoisomerization reaction refers to a compound that causes stereoisomerization or structural isomerization by the action of light. Examples of compounds that cause a photoisomerization reaction include azobenzene compounds and spiropyran compounds. Also, a compound that causes a photodimerization reaction refers to a compound that causes an addition reaction between two groups and is cyclized by light irradiation. Examples of compounds that cause a photodimerization reaction include cinnamic acid derivatives, coumarin derivatives, chalcone derivatives, and benzophenone derivatives. The light is not particularly limited, and examples thereof include ultraviolet light, visible light, and infrared light.
[0083] A preferred example of the photosensitive chiral agent is a chiral agent represented by the following formula (CH1): The chiral agent represented by the following formula (CH1) can change the orientation structure, such as the helical pitch (e.g., helical period and twist period) of the cholesteric liquid crystal phase, depending on the amount of light upon irradiation.
[0084] [ka]
[0085] In formula (CH1), Ar CH1 and Ar CH2 each independently represents an aryl group or a heteroaromatic ring group; R CH1 and R CH2 each independently represents a hydrogen atom or a cyano group.
[0086] Ar in formula (CH1) CH1 and Ar CH2 is preferably an aryl group. CH1 and Ar CH2 The total number of carbon atoms in the aryl group in is preferably 6 to 40, and more preferably 6 to 30. The aryl group may have a substituent. Examples of the substituent include preferably a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, a hydroxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, a carboxy group, a cyano group, or a heterocyclic group, and more preferably a halogen atom, an alkyl group, an alkenyl group, an alkoxy group, a hydroxy group, an acyloxy group, an alkoxycarbonyl group, or an aryloxycarbonyl group.
[0087] Ar CH1 and Ar CH2 is preferably an aryl group represented by the following formula (CH2) or formula (CH3).
[0088] [ka]
[0089] In formula (CH2) and formula (CH3), R CH3 and R CH4 each independently represents a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group, an alkoxy group, a hydroxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, a carboxy group, or a cyano group; L CH1 and L CH2 each independently represents a halogen atom, an alkyl group, an alkoxy group, or a hydroxy group, nCH1 represents an integer of 0 to 4, nCH2 represents an integer of 0 to 6, and * represents the bonding position with C forming an ethylenically unsaturated bond in formula (CH1).
[0090] R in formula (CH2) and formula (CH3) CH3 and R CH4 are each independently preferably a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an aryl group, an alkoxy group, a hydroxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, or an acyloxy group, more preferably an alkoxy group, a hydroxy group, or an acyloxy group, and particularly preferably an alkoxy group. L in formula (CH2) and formula (CH3) CH1 and L CH2 are preferably each independently an alkoxy group having 1 to 10 carbon atoms or a hydroxy group. In the formula (CH2), nCH1 is preferably 0 or 1. In the formula (CH3), nCH2 is preferably 0 or 1.
[0091] Ar of formula (CH1) CH1 and Ar CH2 The total number of carbon atoms in the heteroaromatic ring group in is preferably 4 to 40, more preferably 4 to 30. The heteroaromatic ring group may have a substituent. As the substituent, for example, a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkoxy group, a hydroxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, or a cyano group is preferable, and a halogen atom, an alkyl group, an alkenyl group, an aryl group, an alkoxy group, or an acyloxy group is more preferable. As the heteroaromatic ring group, a pyridyl group, a pyrimidinyl group, a furyl group, or a benzofuranyl group is preferable, and a pyridyl group or a pyrimidinyl group is more preferable.
[0092] In formula (CH1), R CH1 and R CH2 are each preferably independently a hydrogen atom.
[0093] The liquid crystal composition may contain one type of chiral agent alone or two or more types. The content of the chiral agent can be appropriately selected depending on the structure of the specific liquid crystal compound used and the desired pitch of the helical structure. From the viewpoints of ease of forming a cholesteric liquid crystal layer, ease of adjusting the pitch of the helical structure, and suppression of reflectance change after molding, the content of the chiral agent is preferably 1% by mass or more and 20% by mass or less, more preferably 2% by mass or more and 15% by mass or less, and particularly preferably 3% by mass or more and 10% by mass or less, based on the total solid content of the liquid crystal composition.
[0094] When the liquid crystal composition contains a chiral agent having a polymerizable group as a chiral agent, the content of the chiral agent having a polymerizable group is, from the viewpoint of suppressing a change in reflectance after molding, preferably from 0.2 mass % to 15 mass % relative to the total solid content of the liquid crystal composition, more preferably from 0.5 mass % to 10 mass %, even more preferably from 1 mass % to 8 mass %, and particularly preferably from 1.5 mass % to 5 mass %.
[0095] When the liquid crystal composition contains a chiral agent that does not have a polymerizable group as a chiral agent, the content of the chiral agent that does not have a polymerizable group is preferably from 0.2 mass % to 20 mass % inclusive, more preferably from 0.5 mass % to 15 mass % inclusive, and particularly preferably from 1.5 mass % to 10 mass % inclusive, relative to the total solid content of the liquid crystal composition, from the viewpoint of suppressing changes in reflectance after molding.
[0096] In addition, the pitch of the helical structure of the cholesteric liquid crystal in the cholesteric liquid crystal layer, and the selective reflection wavelength and its range described below can be easily changed not only by the type of liquid crystal compound used, but also by adjusting the content of the chiral agent. Although it cannot be said in general, when the content of the chiral agent in the liquid crystal composition is doubled, the pitch may be halved and the center value of the selective reflection wavelength may also be halved.
[0097] -Polymerization initiator- The liquid crystal composition preferably contains a polymerization initiator, and more preferably contains a photopolymerization initiator.
[0098] When the liquid crystal composition contains a cholesteric liquid crystal compound having one ethylenically unsaturated group, the liquid crystal composition preferably contains a radical polymerization initiator, and more preferably contains a photoradical polymerization initiator, from the viewpoint of suppressing changes in reflectance and color after molding.
[0099] When the liquid crystal composition contains a cholesteric liquid crystal compound having one cyclic ether group, from the viewpoint of suppressing changes in reflectance and color tone after molding, the liquid crystal composition preferably contains a cationic polymerization initiator, and more preferably contains a photocationic polymerization initiator.
[0100] The liquid crystal composition preferably contains, as the polymerization initiator, only either a radical polymerization initiator or a cationic polymerization initiator.
[0101] As the polymerization initiator, a known polymerization initiator can be used. In addition, the polymerization initiator is preferably a photopolymerization initiator capable of initiating a polymerization reaction by ultraviolet irradiation. Examples of the photopolymerization initiator include α-carbonyl compounds (described in U.S. Pat. Nos. 2,367,661 and 2,367,670), acyloin ether compounds (described in U.S. Pat. No. 2,448,828), α-hydrocarbon-substituted aromatic acyloin compounds (described in U.S. Pat. No. 2,722,512), polynuclear quinone compounds (described in U.S. Pat. Nos. 3,046,127 and 2,951,758), a combination of triaryl imidazole dimer and p-aminophenyl ketone (described in U.S. Pat. No. 3,549,367), acridine compounds and phenazine compounds (described in JP-A-60-105,667 and U.S. Pat. No. 4,239,850), and oxadiazole compounds (described in U.S. Pat. No. 4,212,970).
[0102] As the photoradical polymerization initiator, a known photoradical polymerization initiator can be used. Preferred examples of the photoradical polymerization initiator include an α-hydroxyalkylphenone compound, an α-aminoalkylphenone compound, and an acylphosphine oxide compound.
[0103] As the cationic photopolymerization initiator, a known cationic photopolymerization initiator can be used. Preferred examples of the cationic photopolymerization initiator include an iodonium salt compound and a sulfonium salt compound.
[0104] The liquid crystal composition may contain one type of polymerization initiator alone or two or more types. The content of the polymerization initiator can be appropriately selected according to the structure of the specific liquid crystal compound used and the desired pitch of the helical structure. From the viewpoints of ease of forming a cholesteric liquid crystal layer, ease of adjusting the pitch of the helical structure, polymerization rate, and strength of the cholesteric liquid crystal layer, the content of the polymerization initiator is preferably 0.05% by mass or more and 10% by mass or less, more preferably 0.05% by mass or more and 5% by mass or less, even more preferably 0.1% by mass or more and 2% by mass or less, and particularly preferably 0.2% by mass or more and 1% by mass or less, based on the total solid content of the liquid crystal composition.
[0105] -Crosslinking agent- The liquid crystal composition may contain a crosslinking agent to improve the strength and durability of the cholesteric liquid crystal layer after curing. As the crosslinking agent, for example, a crosslinking agent that cures with ultraviolet light, heat, or moisture can be suitably used. The crosslinking agent is not particularly limited and can be appropriately selected according to the purpose, and examples thereof include polyfunctional acrylate compounds such as trimethylolpropane tri(meth)acrylate and pentaerythritol tri(meth)acrylate; epoxy compounds such as glycidyl (meth)acrylate and ethylene glycol diglycidyl ether; aziridine compounds such as 2,2-bishydroxymethylbutanol-tris[3-(1-aziridinyl)propionate] and 4,4-bis(ethyleneiminocarbonylamino)diphenylmethane; isocyanate compounds such as hexamethylene diisocyanate and biuret type isocyanate; polyoxazoline compounds having an oxazoline group in the side chain; and alkoxysilane compounds such as vinyltrimethoxysilane and N-(2-aminoethyl)3-aminopropyltrimethoxysilane. In addition, a known catalyst can be used according to the reactivity of the crosslinking agent, and the productivity can be improved in addition to improving the strength and durability of the cholesteric liquid crystal layer.
[0106] The liquid crystal composition may contain one type of crosslinking agent alone or two or more types of crosslinking agents. From the viewpoint of strength and durability of the cholesteric liquid crystal layer, the content of the crosslinking agent is preferably from 1% by mass to 20% by mass, more preferably from 3% by mass to 15% by mass, based on the total solid content of the liquid crystal composition.
[0107] -Multifunctional polymerizable compound- From the viewpoint of suppressing the change in reflectance after molding, the liquid crystal composition preferably contains a polyfunctional polymerizable compound, and more preferably contains a polyfunctional polymerizable compound having the same type of polymerizable group. Examples of the polyfunctional polymerizable compound include the cholesteric liquid crystal compound having two or more ethylenically unsaturated groups and no cyclic ether group, the cholesteric liquid crystal compound having two or more cyclic ether groups and no ethylenically unsaturated group, and the cholesteric liquid crystal compound having two or more ethylenically unsaturated groups and two or more cyclic ether groups, the chiral agent having two or more polymerizable groups, and the crosslinking agent.
[0108] The liquid crystal composition preferably contains, as a polyfunctional polymerizable compound, at least one compound selected from the group consisting of a cholesteric liquid crystal compound having two or more ethylenically unsaturated groups and no cyclic ether group, a cholesteric liquid crystal compound having two or more cyclic ether groups and no ethylenically unsaturated group, and a chiral agent having two or more polymerizable groups, and more preferably contains a chiral agent having two or more polymerizable groups.
[0109] The liquid crystal composition may contain one type of polyfunctional polymerizable compound alone or two or more types. From the viewpoint of suppressing a change in reflectance after molding, the content of the polyfunctional polymerizable compound is preferably 0.5% by mass to 70% by mass, more preferably 1% by mass to 50% by mass, even more preferably 1.5% by mass to 20% by mass, and particularly preferably 2% by mass to 10% by mass, based on the total solid content of the liquid crystal composition.
[0110] -Other additives- The liquid crystal composition may contain additives other than the above-mentioned components as necessary. As the additives, known additives can be used, and examples thereof include surfactants, polymerization inhibitors, antioxidants, horizontal alignment agents, ultraviolet absorbers, light stabilizers, colorants, and metal oxide particles.
[0111] The liquid crystal composition may also contain a solvent. The solvent is not particularly limited and can be appropriately selected depending on the purpose, but an organic solvent is preferably used. The organic solvent is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include ketones (e.g., methyl ethyl ketone and methyl isobutyl ketone), alkyl halides, amides, sulfoxides, heterocyclic compounds, hydrocarbons, esters, and ethers. The solvent may be used alone or in combination of two or more. Among these, ketones are particularly preferred when considering the burden on the environment. The above-mentioned components may also function as a solvent.
[0112] The content of the solvent in the liquid crystal composition is not particularly limited, and may be adjusted to a content of the solvent that provides desired coating properties. The content of the solid content relative to the total mass of the liquid crystal composition is not particularly limited, but is preferably 1% by mass to 90% by mass, more preferably 5% by mass to 80% by mass, and particularly preferably 10% by mass to 80% by mass. The content of the solvent in the liquid crystal composition at the time of curing to form a cholesteric liquid crystal layer is preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 2% by mass or less, and particularly preferably 1% by mass or less, relative to the total solid content of the liquid crystal composition. The content of the solvent in the cholesteric liquid crystal layer obtained by curing the liquid crystal composition is preferably 5% by mass or less, more preferably 3% by mass or less, even more preferably 2% by mass or less, and particularly preferably 1% by mass or less, relative to the total mass of the cholesteric liquid crystal layer.
[0113] - Application and curing of liquid crystal composition - In forming a cholesteric liquid crystal layer, the liquid crystal composition is used by, for example, applying it onto an object (for example, the above-mentioned substrate and the alignment layer described below). The liquid crystal composition can be applied, for example, by making the liquid crystal composition into a solution state using a solvent, or by heating it into a liquid such as a molten liquid, and then by an appropriate method such as a roll coating method, a gravure printing method, or a spin coating method. The liquid crystal composition can also be applied by various methods such as a wire bar coating method, an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, and a die coating method. In addition, the liquid crystal composition can be discharged from a nozzle using an inkjet device to form a coating film (meaning a film-like liquid crystal composition formed by application).
[0114] After the liquid crystal composition is applied, the liquid crystal composition is cured to form a cholesteric liquid crystal layer. The liquid crystal composition is cured to maintain and fix the alignment state of the molecules of the liquid crystal compound (for example, the above-mentioned specific liquid crystal compound). The liquid crystal composition is preferably cured by a polymerization reaction of a polymerizable group (for example, an ethylenically unsaturated group or a cyclic ether group) possessed by the liquid crystal compound. When a solvent is used as a component of the liquid crystal composition, it is preferable to dry the coating film by a known method after the liquid crystal composition is applied and before the polymerization reaction for curing. For example, the coating film may be dried by leaving it to stand, or the coating film may be dried by heating. It is sufficient that the liquid crystal compound in the liquid crystal composition is aligned after the application and drying of the liquid crystal composition.
[0115] -Layer structure of cholesteric liquid crystal layer- From the viewpoint of suppressing changes in reflectance after molding, the decorative film according to the present disclosure preferably has two or more cholesteric liquid crystal layers. The compositions of the two or more cholesteric liquid crystal layers may be the same or different. When the decorative film according to the present disclosure has two or more cholesteric liquid crystal layers, the decorative film according to the present disclosure may have at least one layer formed by curing a liquid crystal composition containing a cholesteric liquid crystal compound (i.e., a specific liquid crystal compound) having one ethylenically unsaturated group or one cyclic ether group in an amount of 25% by mass or more relative to the total solid content of the liquid crystal composition. From the viewpoint of suppressing changes in reflectance after molding, it is preferable that each of the two or more cholesteric liquid crystal layers is a layer formed by curing a liquid crystal composition containing a cholesteric liquid crystal compound having one ethylenically unsaturated group or one cyclic ether group in an amount of 25% by mass or more relative to the total solid content of the liquid crystal composition.
[0116] Furthermore, for example, when the decorative film according to the present disclosure has two cholesteric liquid crystal layers, it is preferable to have a cholesteric liquid crystal layer on each side of the base material from the viewpoint of suppressing changes in reflectance after molding.
[0117] <<Selective reflectivity of the reflective layer>> The reflective layer preferably has a central wavelength of selective reflection wavelength in the range of 300 nm to 1,500 nm. In the present disclosure, the "central wavelength of selective reflection wavelength" refers to the minimum and minimal value of the light transmittance of the target object (e.g., the reflective layer). min (unit:%), the half-value transmittance T is expressed by the following formula 1 / 2 The average value of two wavelengths (unit: %) is shown. However, the first of the two wavelengths is the T min The second of the two wavelengths is the maximum wavelength in the wavelength range that includes wavelengths shorter than the wavelength that shows the above T min The transmittance is the minimum wavelength in a wavelength range including wavelengths longer than the wavelength at which the selective reflection wavelength is observed. The transmittance is measured using a spectrophotometer (e.g., Shimadzu Corporation, spectrophotometer UV-2100). The central wavelength of the selective reflection wavelength may be in the range of 380 nm or more and 780 nm or less, or in the range of more than 780 nm and 1,500 nm or less. Formula for calculating half-value transmittance: T 1 / 2 =100-(100-T min )÷2
[0118] The reflective layer preferably has a maximum reflection wavelength in the wavelength range of 380 nm to 1,500 nm. From the viewpoint of use in a decorative film, the wavelength range including the maximum reflection wavelength is preferably 380 nm to 1,200 nm, more preferably 400 nm to 1,000 nm, and particularly preferably 420 nm to 900 nm.
[0119] From the viewpoints of strength and durability, the thickness of the reflective layer is preferably 0.2 μm to 150 μm, more preferably 0.5 μm to 100 μm, further preferably 1 μm to 50 μm, and particularly preferably 1 μm to 10 μm.
[0120] <Alignment layer> The decorative film according to the present disclosure may have an alignment layer in contact with the cholesteric liquid crystal layer. The alignment layer is used to align the molecules of the liquid crystal compound in the liquid crystal composition when forming a layer containing a liquid crystal compound (hereinafter also referred to as a "liquid crystal layer"). Since the alignment layer is used, for example, when forming the liquid crystal layer, a decorative film that does not include a liquid crystal layer may or may not include an alignment layer.
[0121] The alignment layer can be provided, for example, by rubbing an organic compound (preferably a polymer), oblique deposition of an inorganic compound (e.g., SiO2), or by forming a layer having microgrooves. Furthermore, alignment layers that generate an alignment function by applying an electric field, a magnetic field, or light irradiation are also known. Depending on the material of the lower layer such as the support and the liquid crystal layer, the lower layer can be directly aligned (e.g., rubbing) to function as an alignment layer without providing an alignment layer. An example of such a support that can be the lower layer is polyethylene terephthalate (PET). In addition, when a layer (hereinafter referred to as the "upper layer" in this paragraph) is laminated directly on the liquid crystal layer, the lower liquid crystal layer may act as an alignment layer to align the liquid crystal compound for the preparation of the upper layer. In such a case, the liquid crystal compound in the upper layer can be aligned without providing an alignment layer or performing a special alignment treatment (e.g., rubbing treatment).
[0122] As preferred examples of the alignment layer, a rubbed alignment layer and a photoalignment layer will be described below.
[0123] <<Rubbing treatment alignment layer>> The rubbing treatment alignment layer is an alignment layer to which alignment is imparted by rubbing treatment. Examples of polymers that can be used in the rubbing treatment alignment layer include, for example, methacrylate copolymers, styrene copolymers, polyolefins, polyvinyl alcohol, and modified polyvinyl alcohols described in paragraph 0022 of JP-A-8-338913, as well as poly(N-methylolacrylamide), polyesters, polyimides, vinyl acetate copolymers, carboxymethylcellulose, and polycarbonates. A silane coupling agent can be used as the polymer. As the polymer that can be used in the rubbing treatment alignment layer, water-soluble polymers (e.g., poly(N-methylolacrylamide), carboxymethylcellulose, gelatin, polyvinyl alcohol, and modified polyvinyl alcohol) are preferred, gelatin, polyvinyl alcohol, or modified polyvinyl alcohol are more preferred, and polyvinyl alcohol or modified polyvinyl alcohol is particularly preferred.
[0124] In the method of orienting a liquid crystal compound using a rubbed alignment layer, for example, a composition for forming a cholesteric liquid crystal layer (one form of a liquid crystal composition) is applied to the rubbed surface of the rubbed alignment layer to orient the molecules of the liquid crystal compound. Thereafter, if necessary, a polymer contained in the alignment layer is reacted with a polyfunctional monomer contained in the cholesteric liquid crystal layer, or a crosslinking agent is used to crosslink the polymer contained in the alignment layer, thereby forming a cholesteric liquid crystal layer. The thickness of the alignment layer is preferably in the range of 0.1 μm to 10 μm.
[0125] -Rubbing treatment- The surface of the alignment layer, support, or other layer to which the composition for forming a cholesteric liquid crystal layer is applied may be subjected to a rubbing treatment, if necessary. The rubbing treatment can generally be carried out by rubbing the surface of a film mainly composed of a polymer in a certain direction with paper or cloth. General methods for rubbing treatment are described, for example, in "Liquid Crystal Handbook" (published by Maruzensha, October 30, 2000).
[0126] The rubbing density can be changed by the method described in "Liquid Crystal Handbook" (published by Maruzensha). The rubbing density (L) is quantified by the following formula (A). Formula (A): L=Nl(1+2πrn / 60v) In formula (A), N is the number of rubbings, l is the contact length of the rubbing roller, π is the circular constant, r is the radius of the roller, n is the number of rotations of the roller (rpm: revolutions per minute), and v is the stage movement speed (per second).
[0127] In order to increase the rubbing density, the number of rubbings may be increased, the contact length of the rubbing roller may be increased, the radius of the roller may be increased, the number of rotations of the roller may be increased, or the stage moving speed may be decreased, whereas in order to decrease the rubbing density, the opposite may be done. In addition, the description of Japanese Patent No. 4052558 may be referred to for the conditions of the rubbing treatment.
[0128] <<Photo alignment layer>> The photo-alignment layer is an alignment layer to which alignment is imparted by light irradiation. Photo-alignment materials used in the photo-alignment layer are described in many documents. Examples of photo-alignment materials include azo compounds described in JP 2006-285197 A, JP 2007-76839 A, JP 2007-138138 A, JP 2007-94071 A, JP 2007-121721 A, JP 2007-140465 A, JP 2007-156439 A, JP 2007-133184 A, JP 2009-109831 A, Japanese Patent No. 3883848 A, and Japanese Patent No. 4151746 A, and azo compounds described in JP 2002-229039 A. Preferred examples include aromatic ester compounds, maleimide and / or alkenyl-substituted nadiimide compounds having photo-orientable units described in JP-A-2002-265541 and JP-A-2002-317013, photo-crosslinkable silane derivatives described in JP-A-4205195 and JP-A-4205198, and photo-crosslinkable polyimides, polyamides, or esters described in JP-T-2003-520878, JP-T-2004-529220, and JP-T-4162850. Particularly preferred are azo compounds, photo-crosslinkable polyimides, polyamides, or esters.
[0129] For example, a layer formed from the above material is irradiated with linearly polarized light or non-polarized light to produce a photo-alignment layer. In the present disclosure, "irradiation with linearly polarized light" refers to an operation for causing a photo-reaction in a photo-alignment material. The wavelength of the light used varies depending on the photo-alignment material used, and is not particularly limited as long as it is a wavelength necessary for the photo-reaction. Preferably, the peak wavelength of the light used for photoirradiation is 200 nm to 700 nm, and more preferably, the peak wavelength of the light is ultraviolet light of 400 nm or less.
[0130] The light source used for the light irradiation includes commonly used light sources, such as lamps (e.g., tungsten lamps, halogen lamps, xenon lamps, xenon flash lamps, mercury lamps, mercury xenon lamps, and carbon arc lamps), various lasers (e.g., semiconductor lasers, helium-neon lasers, argon ion lasers, helium cadmium lasers, and YAG (Yttrium Aluminum Garnet) lasers), light-emitting diodes, and cathode ray tubes. It can be done.
[0131] As a means for obtaining linearly polarized light, a method using a polarizing plate (e.g., an iodine polarizing plate, a dichroic dye polarizing plate, and a wire grid polarizing plate), a method using a prism-based element (e.g., a Glan-Thompson prism) and a reflective polarizer utilizing the Brewster angle, or a method using light emitted from a polarized laser light source can be adopted. Also, a filter and a wavelength conversion element may be used to selectively irradiate only light of a required wavelength.
[0132] When the light to be irradiated is linearly polarized, a method is adopted in which the light is irradiated vertically or obliquely to the upper or lower surface of the alignment layer. The incident angle of the light varies depending on the photo-alignment material, but is preferably 0° to 90° (vertical), more preferably 40° to 90°. When non-polarized light is used, the non-polarized light is irradiated obliquely to the upper or lower surface of the alignment layer. The incident angle of the non-polarized light is preferably 10° to 80°, more preferably 20° to 60°, and particularly preferably 30° to 50°. The irradiation time is preferably 1 minute to 60 minutes, more preferably 1 minute to 10 minutes.
[0133] <Resin layer> The decorative film according to the present disclosure preferably has a resin layer between the substrate and the reflective layer. For example, when pressure is applied to the reflective layer to impart an uneven structure, the resin layer deforms, so that the reflective layer can easily follow the unevenness used as a mold.
[0134] The thickness of the resin layer is preferably from 0.2 μm to 100 μm, more preferably from 0.5 μm to 70 μm, and further preferably from 1.0 μm to 50 μm.
[0135] The elastic modulus of the resin layer is preferably 0.000001 GPa to 3 GPa, more preferably 0.00001 to 1 GPa, and even more preferably 0.0001 to 0.5 GPa at 25° C. The elastic modulus is measured by a nanoindenter device (for example, Nanoindenter G200, manufactured by KLA Corporation).
[0136] The resin layer preferably contains a binder resin as a main component. The binder resin is not limited, and any known resin can be used. From the viewpoint of obtaining a desired color, the binder resin is preferably a transparent resin, and specifically, a resin having a total light transmittance of 80% or more is preferable. The total light transmittance can be measured by a spectrophotometer (for example, a spectrophotometer UV-2100 manufactured by Shimadzu Corporation).
[0137] The binder resin is not limited, and known resins can be used. Examples of the binder resin include acrylic resin, silicone resin, polyester, urethane resin, and polyolefin. The binder resin may be a homopolymer of a specific monomer, or a copolymer of a specific monomer and another monomer.
[0138] The binder resin may be used alone or in combination of two or more. From the viewpoint of moldability, the content of the binder resin in the resin layer is preferably 5% by mass to 70% by mass, more preferably 10% by mass to 60% by mass, and particularly preferably 20% by mass to 60% by mass, based on the total mass of the resin layer.
[0139] A known pressure sensitive adhesive or bonding agent may also be used for the resin layer.
[0140] <<Adhesive>> Examples of the adhesive include acrylic adhesives, rubber adhesives, and silicone adhesives. Examples of the adhesive include acrylic adhesives, ultraviolet (UV) curing adhesives, and silicone adhesives described in "Evaluation of Properties of Release Paper / Release Film and Adhesive Tape and Technology for Controlling Them," Information Agency, 2004, Chapter 2. In this disclosure, the acrylic adhesive refers to an adhesive containing a polymer of a (meth)acrylic monomer (i.e., a (meth)acrylic polymer). When the resin layer contains an adhesive, the resin layer may further contain a tackifier.
[0141] <<Adhesive>> Examples of the adhesive include urethane resin adhesives, polyester adhesives, acrylic resin adhesives, ethylene vinyl acetate resin adhesives, polyvinyl alcohol adhesives, polyamide adhesives, and silicone adhesives. In terms of higher adhesive strength, urethane resin adhesives and silicone adhesives are preferred.
[0142] <<Method of forming resin layer>> The method of forming the resin layer is not limited. The resin layer can be formed, for example, by using a composition for forming a resin layer. The composition for forming a resin layer can be prepared, for example, by mixing the raw materials of the resin layer. The method of applying the composition for forming a resin layer can be, for example, the same method as the application method of the liquid crystal composition.
[0143] <<Additives>> The resin layer may contain additives, if necessary, in addition to the above components. The additives are not limited, and known additives can be used. Examples of the additives include surfactants described in paragraph 0017 of Japanese Patent No. 4502784 and paragraphs 0060 to 0071 of Japanese Patent Publication No. 2009-237362, thermal polymerization inhibitors (also called polymerization inhibitors, preferably phenothiazine) described in paragraph 0018 of Japanese Patent No. 4502784, and additives described in paragraphs 0058 to 0071 of Japanese Patent Publication No. 2000-310706.
[0144] <Colored layer> The decorative film according to the present disclosure preferably has a colored layer. In addition, in an embodiment, the decorative film is preferably a decorative film for visually viewing the colored layer through the cholesteric liquid crystal layer. The colored layer may be a colored layer (i.e., not colorless and transparent). The colored layer is preferably an opaque colored layer (preferably a colored layer having a total light transmittance of 10% or less). The color of the colored layer may be black, gray, white, red, orange, yellow, green, blue, or purple. A black colored layer is preferable because the intensity of the reflected light is small and the color change is more emphasized. A white colored layer is preferable from the viewpoint that the light transmitted through the reflective layer is reflected by the colored layer and a color change using a complementary color is obtained. For example, when the reflective layer selectively reflects green light, a color using the complementary color magenta can be expressed.
[0145] The colored layer may be a layer obtained by curing a polymerizable compound, or may be a layer containing a polymerizable compound and a polymerization initiator. From the viewpoint of storage stability and adhesion between the colored layer and other layers, the colored layer is preferably a layer obtained by curing a polymerizable compound, and more preferably a layer obtained by curing at least a bifunctional or trifunctional polymerizable compound having at least one partial structure selected from the group consisting of a urethane bond and an alkyleneoxy group having 2 or 3 carbon atoms.
[0146] <<Coloring agent>> From the viewpoint of visibility, the colored layer preferably contains a colorant, and from the viewpoint of durability, it is more preferable that the colorant contains a pigment. The colorant is not particularly limited, and a colorant having a desired hue can be appropriately selected and used. Examples of the colorant include pigments and dyes, and pigments are preferable. In addition, the pigment is preferably a particulate pigment. As the pigment, various inorganic pigments and organic pigments known in the art can be used.
[0147] Examples of inorganic pigments include those described in paragraphs 0015 and 0114 of JP-A-2005-7765. Specific examples of inorganic pigments include white pigments (e.g., titanium dioxide, zinc oxide, lithopone, precipitated calcium carbonate, white carbon, aluminum oxide, aluminum hydroxide, and barium sulfate) and black pigments (e.g., carbon black, titanium black, titanium carbon, iron oxide, and graphite). Known chromatic pigments such as iron oxide, barium yellow, cadmium red, and chrome yellow can also be used.
[0148] Examples of the organic pigment include the organic pigments described in paragraph 0093 of JP-A-2009-256572. Specific examples of the organic pigment include CI Pigment red pigments such as CI Pigment Red 177, 179, 224, 242, 254, 255, 264, etc.; yellow pigments such as CI Pigment Yellow 138, 139, 150, 180, 185, etc.; orange pigments such as CI Pigment Orange 36, 38, 71, etc.; green pigments such as CI Pigment Green 7, 36, 58, etc.; blue pigments such as CI Pigment Blue 15:6, etc.; and purple pigments such as CI Pigment Violet 23, etc.
[0149] In addition, the colored layer may contain particles of a pigment having light transmittance and light reflectance (so-called glittering pigment) as a pigment. When the method for forming the colored layer includes a step of exposing the colored layer to light, the glittering pigment is preferably used within a range that does not interfere with curing by exposure.
[0150] The colorants may be used alone or in combination of two or more. In addition, inorganic pigment particles and organic pigment particles may be used in combination. The content of the colorant in the colored layer is preferably 1% by mass to 50% by mass, more preferably 5% by mass to 50% by mass, and even more preferably 10% by mass to 40% by mass, based on the total mass of the colored layer, from the viewpoints of expressing a desired hue (for example, suppressing whitening) and maintaining the shape conformability of the colored layer to the mold. Here, "whitening" in the present disclosure refers to a change in the colored layer to exhibit a whitish color with a matte feel.
[0151] <<Polymerizable compounds>> The colored layer used in the present disclosure may contain a polymerizable compound. The polymerizable compound is a compound having a polymerizable group.
[0152] Examples of the polymerizable group include an ethylenically unsaturated group and an epoxy group, and from the viewpoint of curability, etc., an ethylenically unsaturated group is preferred, and a (meth)acryloxy group is more preferred. Moreover, the polymerizable group is preferably a radically polymerizable group.
[0153] The polymerizable compound is preferably a bifunctional or trifunctional polymerizable compound having at least one partial structure selected from the group consisting of a urethane bond, a urea bond, an alkyleneoxy group having 2 or 3 carbon atoms, and a hydrocarbon group having 6 to 12 carbon atoms (hereinafter also referred to as a "specific polymerizable compound"), and more preferably a compound containing a urethane bond in the partial structure.
[0154] -Bifunctional or trifunctional polymerizable compound having a urethane bond- The bifunctional or trifunctional polymerizable compound having a urethane bond (hereinafter also referred to as "specific polymerizable compound 1") is preferably a urethane oligomer. The nitrogen atom in the urethane bond may be disubstituted (one of the groups on the nitrogen atom is a hydrogen atom) or trisubstituted. In addition, the specific polymerizable compound 1 preferably has a urethane resin chain.
[0155] The urethane oligomer is preferably a urethane (meth)acrylate oligomer. The urethane (meth)acrylate oligomer can be, for example, an aliphatic urethane (meth)acrylate and an aromatic urethane (meth)acrylate. For details, Oligomer Handbook (supervised by Junji Furukawa, published by The Chemical Daily Co., Ltd.) can be referred to, and the urethane oligomer described therein can be appropriately selected according to purpose and used to form a colored layer.
[0156] The molecular weight of the urethane oligomer, which is a type of specific polymerizable compound 1, is preferably 800 to 2,000, and more preferably 1,000 to 2,000.
[0157] As the urethane (meth)acrylate oligomer, which is one type of specific polymerizable compound 1, a commercially available product may be used. Commercially available urethane (meth)acrylate oligomers include, for example, U-2PPA and UA-122P manufactured by Shin-Nakamura Chemical Co., Ltd.; CN964A85, CN964, CN959, CN962, CN963J85, CN965, CN982B88, CN981, CN983, CN991, CN991NS, CN996, CN996NS, CN9002, CN9007, CN9178, and CN9893 manufactured by Sartomer Japan Co., Ltd.; and EBECRYL230, EBECRYL270, EBECRYL284, EBECRYL4858, EBECRYL210, EBECRYL8402, EBECRYL8804, and EBECRYL8800-20R (all trade names) manufactured by Daicel-Allnex Corporation. In addition, "EBECRYL" is a registered trademark.
[0158] <<Dispersant>> From the viewpoint of improving the dispersibility of the pigment contained in the colored layer, the colored layer may contain a dispersant. By including a dispersant in the colored layer, the dispersibility of the pigment in the colored layer formed is improved, and the hue of the resulting decorative film can be made uniform.
[0159] The dispersant can be appropriately selected depending on the type and shape of the pigment, but is preferably a polymer dispersant. Examples of the polymer dispersant include silicone polymers, acrylic polymers, and polyester polymers.
[0160] When it is desired to impart heat resistance to the decorative film, it is preferable to use, for example, a silicone polymer such as a graft type silicone polymer as a dispersant.
[0161] The weight average molecular weight of the dispersant is preferably from 1,000 to 5,000,000, more preferably from 2,000 to 3,000,000, and particularly preferably from 2,500 to 3,000,000. When the weight average molecular weight is 1,000 or more, the dispersibility of the pigment is further improved.
[0162] As the dispersant, commercially available products may be used. Examples of commercially available products include EFKA 4300 (acrylic polymer dispersant) from BASF Japan, Homogenol L-18, Homogenol L-95, and Homogenol L-100 from Kao Corporation, Pers 20000 and Solsperse 24000 from Lubrizol Japan, and DISPERBYK-110, DISPERBYK-164, DISPERBYK-180, and DISPERBYK-182 from BYK-Chemie Japan. Note that "Homogenol", "Solsperse", and "DISPERBYK" are all registered trademarks.
[0163] When the colored layer contains a dispersant, the dispersant may contain only one type of dispersant, or may contain two or more types of dispersants. The content of the dispersant is preferably 1 part by mass to 30 parts by mass with respect to 100 parts by mass of the colorant.
[0164] <<Polymerization initiator>> The colored layer may contain a polymerization initiator. As the polymerization initiator, a photopolymerization initiator is preferable from the viewpoint of increasing sensitivity to light exposure. As the photopolymerization initiator, for example, the polymerization initiator described in paragraphs 0031 to 0042 of JP2011-95716A and the oxime-based polymerization initiator described in paragraphs 0064 to 0081 of JP2015-014783A can be used.
[0165] Specific examples of the photopolymerization initiator include 1-[4-(phenylthio)phenyl]-1,2-octanedione-2-(O-benzoyloxime) (e.g., IRGACURE® OXE-01, manufactured by BASF), [9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethan-1-one-1-(O-acetyloxime) (e.g., IRGACURE® OXE-02, manufactured by BASF), 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone (e.g., IRGACURE® 379EG, manufactured by BASF), 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one (e.g., IRGACURE® 907 ... hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl}-2-methyl-propan-1-one (e.g., IRGACURE (registered trademark) 127, manufactured by BASF), 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone-1 (e.g., IRGACURE (registered trademark) 369, manufactured by BASF), 2-hydroxy-2-methyl-1-phenylpropan-1-one (e.g., IRGACURE (registered trademark) 1173, manufactured by BASF), 1-hydroxycyclohexyl phenyl ketone (e.g., IRGACURE (registered trademark) 184, manufactured by BASF), 2,2-dimethoxy-1,2-diphenylethane-1-one (e.g., IRGACURE (registered trademark) 651, manufactured by BASF), and an oxime ester polymerization initiator (trade name: Lunar 6 (manufactured by DKSH Japan Co., Ltd.), 2,4-diethylthioxanthone (e.g., Kayacure DETX-S, manufactured by Nippon Kayaku Co., Ltd.), and fluorene oxime polymerization initiators DFI-091 and DFI-020 (both manufactured by Daito Chemistry Co., Ltd.).
[0166] Among these, from the viewpoint of enhancing the curing sensitivity, it is preferable to use an initiator other than a halogen-containing polymerization initiator such as a trichloromethyltriazine-based compound, and an oxime-based polymerization initiator such as an α-aminoalkylphenone-based compound, an α-hydroxyalkylphenone-based compound, or an oxime ester-based compound is more preferable.
[0167] The content of the polymerization initiator is preferably from 0.1 to 15 parts by mass, and more preferably from 0.5 to 10 parts by mass, relative to 100 parts by mass of the polymerizable compound.
[0168] <<Binder resin>> The colored layer preferably contains a binder resin from the viewpoint of reducing the cure shrinkage of the colored layer. The binder resin is not particularly limited, and a known resin can be appropriately selected. The binder resin is preferably a transparent resin from the viewpoint of obtaining a desired hue, and specifically, a resin having a total light transmittance of 80% or more is preferable. The total light transmittance can be measured by a spectrophotometer (for example, a spectrophotometer UV-2100 manufactured by Shimadzu Corporation).
[0169] Examples of the binder resin include acrylic resin, silicone resin, polyester resin, urethane resin, and olefin resin. Among them, from the viewpoint of transparency, acrylic resin, silicone resin, or polyester resin is preferable, and acrylic resin or silicone resin is more preferable. Furthermore, from the viewpoint of heat resistance, silicone resin is preferable.
[0170] In the present disclosure, the term "acrylic resin" refers to a resin containing a structural unit derived from an acrylic monomer having a (meth)acryloyl group. The term "(meth)acryloyl group" is a concept that includes a methacryloyl group and an acryloyl group. The acrylic resin includes, for example, a homopolymer of acrylic acid, a homopolymer of methacrylic acid, a homopolymer of an acrylic acid ester, a homopolymer of a methacrylic acid ester, a copolymer of acrylic acid and other monomers, a copolymer of methacrylic acid and other monomers, a copolymer of an acrylic acid ester and other monomers, a copolymer of a methacrylic acid ester and other monomers, and a urethane-modified copolymer having a urethane skeleton in the side chain. Examples of the acrylic resin include a glycidyl methacrylate adduct of a cyclohexyl methacrylate / methyl methacrylate / methacrylic acid copolymer, a random copolymer of benzyl methacrylate / methacrylic acid, a copolymer of allyl methacrylate / methacrylic acid, and a copolymer of benzyl methacrylate / methacrylic acid / hydroxyethyl methacrylate.
[0171] As the silicone resin, known silicone resins can be used, for example, methyl-based straight silicone resin, methylphenyl-based straight silicone resin, acrylic resin-modified silicone resin, ester resin-modified silicone resin, epoxy resin-modified silicone resin, alkyd resin-modified silicone resin, and rubber-based silicone resin. Among them, methyl-based straight silicone resin, methylphenyl-based straight silicone resin, acrylic resin-modified silicone resin, or rubber-based silicone resin is preferred, and methyl-based straight silicone resin, methylphenyl-based straight silicone resin, or rubber-based silicone resin is more preferred.
[0172] As the silicone resin, commercially available products may be used, and examples of commercially available products include KR-300, KR-311, KR-251, X-40-2406M, and KR-282 manufactured by Shin-Etsu Chemical Co., Ltd.
[0173] Examples of the polyester resin include linear saturated polyesters synthesized from an aromatic dibasic acid or its ester-forming derivative and a diol or its ester-forming derivative. Specific examples of linear saturated polyesters include polyethylene terephthalate, polyethylene isophthalate, polybutylene terephthalate, poly(1,4-cyclohexylene dimethylene terephthalate), and polyethylene-2,6-naphthalate.
[0174] The content of the binder resin is preferably 5% by mass to 70% by mass, more preferably 10% by mass to 60% by mass, and even more preferably 20% by mass to 60% by mass, based on the total mass of the colored layer, from the viewpoint of reducing the cure shrinkage of the colored layer. The ratio of the total amount of the binder resin to the total amount of the polymerizable compounds including the specific polymerizable compound, i.e., the total amount of the polymerizable compounds / the total amount of the binder resin, is preferably 0.3 to 1.5, and more preferably 0.5 to 1.0.
[0175] <<Other ingredients>> The colored layer may contain additives as necessary in addition to the above components. As the additives, known additives can be used, for example, surfactants described in paragraph 0017 of Japanese Patent No. 4502784 and paragraphs 0060 to 0071 of Japanese Patent Publication No. 2009-237362, thermal polymerization inhibitors (also called polymerization inhibitors, preferably phenothiazine) described in paragraph 0018 of Japanese Patent No. 4502784, and other additives described in paragraphs 0058 to 0071 of Japanese Patent Publication No. 2000-310706.
[0176] <<Formation of colored layer>> The method of forming the colored layer is not particularly limited, but it is preferable to form the colored layer using a composition for forming a colored layer. The composition for forming a colored layer preferably contains a colorant, and more preferably contains a colorant and an organic solvent. The composition for forming a colored layer may further contain other components described above. The composition for forming a colored layer can be prepared, for example, by mixing an organic solvent and a component contained in the colored layer, such as a colorant. The content of the components contained in the colored layer is described as the content (mass%) relative to the total mass of the colored layer, but when these components are contained in the composition for forming a colored layer, the content is to be read as the content (mass%) relative to the total solid content of the composition for forming a colored layer.
[0177] In addition, when the composition for forming a colored layer contains a pigment as a colorant, it is preferable to prepare a pigment dispersion containing the pigment and its dispersant in advance and use this pigment dispersion to prepare the composition for forming a colored layer, from the viewpoint of further enhancing the uniform dispersibility and dispersion stability of the pigment.
[0178] The color layer forming composition may be one prepared in advance by the above-mentioned method, or a commercially available product may be used, or the color layer forming composition may be prepared immediately before coating.
[0179] -Organic solvents- As the organic solvent, any organic solvent that is commonly used can be used without any particular limitation.Specific examples of the organic solvent include esters, ethers, ketones, aromatic hydrocarbons, and the like.In addition, methyl ethyl ketone, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cyclohexanone, cyclohexanol, methyl isobutyl ketone, ethyl lactate, methyl lactate, and the like, which are the same as the solvents described in paragraphs 0054 and 0055 of U.S. Patent Application Publication No. 2005 / 282073, can also be suitably used as the organic solvent in the colored layer forming composition. Among them, 1-methoxy-2-propyl acetate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl cellosolve acetate, ethyl lactate, butyl acetate, methyl 3-methoxypropionate, 2-heptanone, cyclohexanone, diethylene glycol monoethyl ether acetate (ethyl carbitol acetate), diethylene glycol monobutyl ether acetate (butyl carbitol acetate), propylene glycol methyl ether acetate, methyl ethyl ketone, etc. are preferably used as organic solvents in the colored layer forming composition. These organic solvents may be used alone or in combination of two or more. The content of the organic solvent is not particularly limited, but is preferably 5% by mass to 90% by mass, more preferably 30% by mass to 70% by mass, based on the total mass of the colored layer forming composition (for example, coating liquid).
[0180] <Adhesive layer> The decorative film according to the present disclosure preferably has an adhesive layer from the viewpoint of adhesion to the housing to which the decorative film is attached or adhesion between layers. The material of the adhesive layer is not particularly limited and can be appropriately selected according to the purpose. For example, the adhesive layer may be a layer containing a known pressure-sensitive adhesive or adhesive.
[0181] <<Adhesive>> Examples of the adhesive include acrylic adhesives, rubber adhesives, and silicone adhesives. Examples of the adhesive include the acrylic adhesives, ultraviolet (UV) curing adhesives, and silicone adhesives described in Chapter 2 of "Evaluation of Properties of Release Paper, Release Film, and Adhesive Tape and Technology for Controlling Them," Information Agency, 2004. When the adhesive layer contains an adhesive, the adhesive layer may further contain a tackifier.
[0182] <<Adhesive>> Examples of the adhesive include urethane resin adhesives, polyester adhesives, acrylic resin adhesives, ethylene vinyl acetate resin adhesives, polyvinyl alcohol adhesives, polyamide adhesives, and silicone adhesives. In terms of higher adhesive strength, urethane resin adhesives and silicone adhesives are preferred.
[0183] In the decorative film according to one embodiment, the relationship between the thickness (T2) of the colored layer, the thickness (T3) of the reflective layer (preferably a cholesteric liquid crystal layer), and the thickness (T4) of the adhesive layer preferably satisfies T4<10(T2+T3). By satisfying the above relationship, a decorative film that is thin and has excellent glitter and visibility can be obtained. More preferably, T4<8(T2+T3), even more preferably, T4<5(T2+T3), and particularly preferably, T4<3(T2+T3).
[0184] <<How to form an adhesive layer>> The method of forming the adhesive layer is not particularly limited, and examples thereof include a method of laminating a protective film on which an adhesive layer is formed so that the adhesive layer contacts an object (e.g., a reflective layer, an alignment layer, or a colored layer), a method of laminating an adhesive layer alone so that the adhesive layer contacts an object (e.g., a reflective layer, an alignment layer, or a colored layer), and a method of applying a composition containing a pressure-sensitive adhesive or adhesive onto an object (e.g., a reflective layer, an alignment layer, or a colored layer). A known method can be used as the lamination method. A preferred application method is the same as the application method of the liquid crystal composition.
[0185] The thickness of the adhesive layer in the decorative film is preferably 2 μm to 40 μm, more preferably 3 μm to 25 μm, further preferably 4 μm to 20 μm, and particularly preferably 4 μm to 15 μm, from the viewpoint of achieving both adhesive strength and handleability.
[0186] <Other layers> The decorative film according to the present disclosure may have layers other than those described above. Examples of the other layers include a self-repairing layer, an antistatic layer, an antifouling layer, an anti-electromagnetic wave layer, and a conductive layer, which are layers known in decorative films. The other layers in the decorative film according to the present disclosure can be formed by a known method. For example, a method of applying a composition (layer-forming composition) containing the components contained in these layers in a layer form and drying it can be mentioned.
[0187] <<Cover film>> The decorative film according to the present disclosure may have a cover film as the outermost layer on the reflective layer side based on the substrate for the purpose of preventing dirt, etc. The cover film may be made of any material that is flexible and has good peelability, and examples of such materials include resin films. Examples of such resin films include polyethylene films. The cover film is introduced into the decorative film by, for example, attaching it to an object (e.g., a reflective layer). The method of attaching the cover film is not particularly limited, and examples of such methods include known attachment methods, and examples of such methods include a method of laminating the cover film on the object (e.g., a reflective layer).
[0188] <Layer structure of decorative film> Here, an example of the layer structure of the decorative film will be described with reference to Fig. 1 and Fig. 2. However, the layer structure of the decorative film is not limited to the layer structure shown in each figure. Fig. 1 is a schematic cross-sectional view showing an example of the layer structure of the decorative film according to the present disclosure. The decorative film 20 shown in Fig. 1 has a base material 22, a colored layer 24 on the base material 22, an alignment layer 26 on the colored layer 24, a cholesteric liquid crystal layer (reflective layer) 28 on the alignment layer 26, and an adhesive layer 30 on the cholesteric liquid crystal layer 28.
[0189] Fig. 2 is a schematic cross-sectional view showing an example of the layer structure of the decorative film according to the present disclosure. The decorative film 50 shown in Fig. 2 has a colored layer 32, a substrate 34 on the colored layer 32, a resin layer 36 on the substrate 34, an alignment layer 38 on the resin layer 36, and a cholesteric liquid crystal layer (reflective layer) 40 on the alignment layer 38.
[0190] <Method of manufacturing decorative film> The manufacturing method of the decorative film according to the present disclosure is not limited. For example, a decorative film having at least a substrate and a reflective layer can be manufactured by providing a reflective layer and, if necessary, a layer other than the reflective layer on a substrate. The above-mentioned methods can be used to form each layer. A plurality of laminates including two or more layers may be manufactured in advance, and the laminates may be stacked to manufacture the decorative film.
[0191] (Decoration method and decoration) The decoration method according to the present disclosure is not particularly limited as long as it is a decoration method using the decorative film according to the present disclosure. For example, the decoration method according to the present disclosure preferably includes a step of attaching the reflective layer side surface of the decorative film and the convex surface of a transparent body having a convex structure by a lamination or molding process. The decorated object according to the present disclosure is preferably a decorated object using the decorative film according to the present disclosure, and is preferably a decorated object obtained by the decoration method according to the present disclosure.
[0192] In the step of attaching the surface of the decorative film on the reflective layer side to the convex surface of the transparent body having a convex structure, it is preferable to perform an activation treatment in advance on the surface of the decorative film on the reflective layer side and / or the convex surface of the transparent body having a convex structure. The advance activation treatment improves adhesion. Examples of the activation treatment include corona treatment, plasma treatment, and silane coupling agent treatment. Corona treatment is most preferable from the viewpoint of ease of production process.
[0193] (Decorative molding) The present disclosure relates to a decorated molded body that includes a base material and a reflective layer having a convex structure with a specific shape. The decorated molded body is one form of a decorative article. According to the above embodiment, a decorated molded body that has high brilliance and rich color variation depending on the viewing direction is provided.
[0194] <Base material> The decorated molded body according to the present disclosure includes a substrate. For example, the substrate described in the above "decorative film" section can be used as the substrate. The preferred embodiment of the substrate is the same as the preferred embodiment of the substrate described in the above "decorative film". The substrate may have a linear convex structure.
[0195] <Reflection layer> The decorated molded body according to the present disclosure includes a reflective layer. The reflective layer has a convex structure. The reflective layer described in the above "Decorative Film" section can be used as the reflective layer. The preferred embodiment of the reflective layer is the same as the preferred embodiment of the reflective layer described in the above "Decorative Film" section. In an embodiment, the reflective layer is preferably a layer containing cholesteric liquid crystal.
[0196] <Resin layer> The decorated molded body according to the present disclosure preferably includes a resin layer between the substrate and the reflective layer. The resin layer particularly contributes to the formation of a convex structure in the reflective layer. For example, the resin layer can improve the conformability of the reflective layer to a surface having a convex structure (i.e., a convex surface) used as a mold for imparting a convex structure to the reflective layer. As a result, the desired convex structure can be easily imparted to the reflective layer.
[0197] As the resin layer, the resin layer described in the above "decorative film" section can be used. The preferred embodiment of the resin layer is the same as the preferred embodiment of the resin layer described in the above "decorative film". The resin layer may have a convex structure. It is preferred that the resin layer has the same convex structure as the reflective layer.
[0198] The thickness of the resin layer is preferably 0.5 to 10 times, more preferably 0.8 to 8 times, and particularly preferably 1 to 5 times the depth (height) of the convex structure of the reflective layer.
[0199] <Colored layer> The decorated molded body according to the present disclosure preferably includes a colored layer. As the colored layer, the colored layer described in the above "decorative film" section can be used. The preferred embodiment of the colored layer is the same as the preferred embodiment of the colored layer described in the above "decorative film". The colored layer may have a convex structure.
[0200] The position of the colored layer is not limited. In an embodiment, the colored layer is preferably disposed between the substrate and the reflective layer. That is, the decorated molded body according to an embodiment preferably includes the substrate, the colored layer, and the reflective layer in this order. In an embodiment, the colored layer is preferably disposed on the opposite side of the substrate to the reflective layer. That is, the decorated molded body according to an embodiment preferably includes the colored layer, the substrate, and the reflective layer in this order.
[0201] <Alignment layer> The decorated molded body according to the present disclosure may include an alignment layer. The alignment layer is preferably in contact with a reflective layer (preferably a cholesteric liquid crystal layer). As the alignment layer, the alignment layer described in the above "Decorative Film" section can be used. A preferred embodiment of the alignment layer is the same as the preferred embodiment of the alignment layer described in the above "Decorative Film". The alignment layer may have a convex structure.
[0202] <Adhesive layer> The decorated molded body according to the present disclosure may include an adhesive layer. The adhesive layer may be disposed on the surface of the decorated molded body. The adhesive layer may be disposed between any two layers included in the decorated molded body. As the adhesive layer, the adhesive layer described in the above "Decorative Film" section may be used. A preferred embodiment of the adhesive layer is the same as the preferred embodiment of the adhesive layer described in the above "Decorative Film" section. The adhesive layer may have a convex structure.
[0203] <Transparent body with convex structure> The decorated molded body according to the present disclosure preferably includes a transparent body having a convex structure, and more preferably includes a resin substrate and a sheet having a convex shape formed by a cured product of a curable composition provided on at least one surface of the resin substrate.
[0204] (Resin substrate) Examples of the resin substrate include sheets or films of acrylic resin, polyester resin, polycarbonate resin, and the like. An example of the acrylic resin is polymethyl methacrylate. Examples of polyester resins include polyethylene terephthalate (PET) and polyethylene naphthalate (PEN).
[0205] The thickness of the resin substrate is not particularly limited, but is preferably in the range of 50 μm to 300 μm, and more preferably in the range of 50 μm to 200 μm when uniformly molded (shaped) at high temperature. When in the above range, the resin substrate is less likely to break, is less likely to crack during handling (e.g., during transportation) during molding processing, and is less likely to crack during three-dimensional molding.
[0206] The resin substrate may be a commercially available product, such as an acrylic resin film manufactured by Mitsubishi Chemical Corporation (Acryplene HBS010P (PMMA film), thickness: 125 μm), a polyethylene terephthalate resin film manufactured by Toray Industries, Inc. (Lumirror S10, thickness: 100 μm), or a polycarbonate resin film manufactured by Teijin Chemicals Co., Ltd. (Iupilon H-3000, thickness: 125 μm).
[0207] The transparent body having a convex structure preferably includes a process for preparing a curable resin composition (composition preparation process), a process for curing the photo- or thermosetting composition by irradiation with active energy rays or by heating to prepare a molding sheet (sheet preparation process), and a process for molding the curable composition into a desired shape using a mold such as a metal mold or a wooden mold.
[0208] Specifically, for example, a mold processed into a desired convex shape is prepared, the curable composition is poured into the mold, and the mold is dried as necessary, and then the curable composition is cured. In this way, a molded product molded into a desired shape can be stably obtained.
[0209] Next, the polymerizable composition is irradiated with active energy rays to generate radicals, which cause a polymerization reaction of the polymerizable compound to proceed, thereby forming a convex shape that is a cured product of the curable composition. In forming a convex shape, the resin substrate may be brought into contact with the curable composition before the curing composition is cured, and then the curable composition may be cured. By curing the curable composition in a state where the resin substrate and the curable composition are in contact with each other, it is possible to expect an improvement in adhesion due to cure shrinkage, and in addition to the adhesion effect derived from the composition, the improvement in adhesion to the resin substrate is more effectively achieved.
[0210] The mold for forming the convex structure can be made by known methods such as cutting and etching. It is preferable to use a mold made by an etching process because it is easy to obtain brilliance when the decoration is held in the hand and tilted to be viewed. From the viewpoint of brilliance when viewed from the front, it is preferable to use a mold made by cutting.
[0211] <Other layers> The decorated molded body according to the present disclosure may include layers other than the layers described above. For example, the layers described in the "decorative film" section above can be used as the other layers.
[0212] The decorated molded body according to the present disclosure may include a transparent body having a surface with a convex structure (i.e., a convex surface). In an embodiment, the decorated molded body preferably includes a substrate, a reflective layer, and a transparent body having a surface with a concave-convex structure, in this order. For example, by observing the decorated molded body in a direction from the transparent body to the substrate, a user can observe high brilliance and uniform color regardless of the viewing direction. The transparent body is preferably in contact with a reflective layer (preferably a cholesteric liquid crystal layer). The transparent body may be in contact with the reflective layer via another layer (e.g., an alignment layer). The convex surface of the transparent body is preferably facing the reflective layer. Examples of the transparent body include transparent resin and glass.
[0213] <Layer structure of decorated molded body> Examples of the layer structure of the decorated molded body will be described with reference to Figures 3, 4, and 5. However, the layer structure of the decorated molded body is not limited to the layer structures shown in each figure.
[0214] Fig. 3 is a schematic cross-sectional view showing an example of a decorated molded body according to the present disclosure. The decorated molded body 70 shown in Fig. 3 has, in this order, a substrate 22, a colored layer 24, an alignment layer 26, a cholesteric liquid crystal layer (reflective layer) 28, an adhesive layer 30, and a transparent body 60 having a linear convex structure. The transparent body 60 is one form of a transparent body.
[0215] Fig. 4 is a schematic cross-sectional view showing an example of a decorated molded body according to the present disclosure. The decorated molded body 80 shown in Fig. 4 has, in this order, a colored layer 32, a substrate 34, a resin layer 36, an alignment layer 38, a cholesteric liquid crystal layer (reflective layer) 40, and a transparent body 60 having a linear convex structure.
[0216] Fig. 5 is a schematic cross-sectional view showing an example of a decorated molded body according to the present disclosure. The decorated molded body 90 shown in Fig. 5 has, in this order, a colored layer 32, a substrate 34, a resin layer 36, a cholesteric liquid crystal layer (reflective layer) 40, an alignment layer 38, and a transparent body 60 having a linear convex structure.
[0217] Fig. 10 is a schematic cross-sectional view showing an example of a decorative molded body for display according to the present disclosure. The decorative molded body 120 shown in Fig. 10 has a retardation layer 110 of a quarter-wave plate, a base material 34, a resin layer 36, a cholesteric liquid crystal layer (reflective layer) 40, an alignment layer 38, a transparent body 60 having a linear convex structure, a retardation layer 112 of a quarter-wave plate, an adhesive layer 114, and a liquid crystal axially symmetric polarization converter 116 in this order.
[0218] <Manufacturing method of decorated molded body> The manufacturing method of the decorated molded body according to the present disclosure is preferably a method using the decorative film according to the present disclosure. The manufacturing method of the decorated molded body according to the present disclosure is preferably a process of attaching the decorative film to a transparent body having a convex structure on the reflective layer side of the decorative film. The decorative film according to the present disclosure is also excellent in three-dimensional moldability, so it can be suitably used for manufacturing the decorated molded body, and is particularly suitable for manufacturing the decorated molded body by at least one molding selected from the group consisting of thermal lamination, three-dimensional molding, and insert molding. In addition, according to the decorative film according to the present disclosure, it is also possible to make a decorated molded body by attaching it to a molded body after molding. When producing a decorated molded body, by using the decorative film according to the present disclosure, it becomes possible to apply it to molds with more complex shapes, smaller shapes, etc., and the range of uses of the decorated molded body can be expanded. The layer structure of the decorated molded body obtained by using the decorative film reflects the layer structure of the decorative film. In other words, the decorated molded body obtained by using the decorative film includes each layer included in the decorative film.
[0219] In addition, three-dimensional molding is also suitable as a molding method. For example, three-dimensional molding is preferably exemplified by thermoforming, vacuum molding, pressure molding, and vacuum pressure molding. The vacuum molding method is not particularly limited, but a method in which three-dimensional molding is performed in a heated state under vacuum is preferred. Vacuum refers to a state in which the pressure inside the room is reduced to a vacuum degree of 100 Pa or less. The temperature during three-dimensional molding may be appropriately set according to the molding substrate used, but is preferably a temperature range of 60°C or higher, more preferably a temperature range of 80°C or higher, and even more preferably a temperature range of 100°C or higher. The upper limit of the temperature during three-dimensional molding is preferably 200°C. The temperature during three-dimensional molding refers to the temperature of the molding substrate used for three-dimensional molding, and is measured by attaching a thermocouple to the surface of the molding substrate.
[0220] Vacuum molding can be carried out using vacuum molding techniques that are widely known in the molding field. For example, vacuum molding may be carried out using Formech 508FS manufactured by Nippon Touki Kogyo Co., Ltd.
[0221] The manufacturing method of the decorated molded body will be specifically described below. The manufacturing method of the decorated molded body according to the present disclosure preferably includes a step of preparing a decorative film having at least a substrate and a reflective layer, and a step of contacting the reflective layer with a surface having a convex structure, applying a pressure of 0.01 MPa or more to the reflective layer, and imparting a convex structure to the reflective layer. The surface having the convex structure functions as a mold for imparting a convex structure to the reflective layer. By contacting the reflective layer with a surface having a concave-convex structure and applying pressure to the reflective layer, the reflective layer is deformed along the surface having the convex structure. As a result, the reflective layer is imparted with a convex structure.
[0222] The layer structure of the decorative film may be determined according to the layer structure of the intended decorated molded body. For example, by using a decorative film having a base material, a reflective layer, and a resin layer between the base material and the reflective layer, a decorated molded body including the base material, the resin layer, and the reflective layer in this order can be obtained.
[0223] The structured surface may be defined by the exterior surface of a variety of articles. The structured surface may be, for example, a surface of a mold, or may be a surface of an article other than a mold.
[0224] In the process of bringing the reflective layer into contact with the surface having the convex structure, the reflective layer may be brought close to the surface having the convex structure, or the surface having the convex structure may be brought close to the reflective layer. The reflective layer may be brought into contact with the surface having the convex structure via another layer (e.g., an alignment layer).
[0225] The pressure applied to the reflective layer is preferably 0.1 MPa or more, more preferably 0.3 MPa or more, and particularly preferably 0.5 MPa or more. The upper limit of the pressure applied to the reflective layer is not limited. The upper limit of the pressure applied to the reflective layer may be determined, for example, according to the processability of the reflective layer and the thickness of the decorative film. The pressure applied to the reflective layer is preferably 10 MPa or less, more preferably 3 MPa or less, and particularly preferably 1 MPa or less.
[0226] The method of applying pressure to the reflective layer is not limited, and any known method can be used. Examples of the pressure application method include a method using compressed air and a method using a press machine.
[0227] In the manufacturing method of the decorated molded body, for example, a transparent body having a surface with the above-mentioned convex structure (i.e., a convex surface) may be used as an article having a surface with a convex structure. For example, a manufacturing method of the decorated molded body according to an embodiment preferably includes a step of preparing a decorative film having at least a substrate and a reflective layer having a selective reflection wavelength with a central wavelength in the range of 300 nm to 1,500 nm, and a step of contacting the reflective layer with the surface with the convex structure by superposing the transparent body having a surface with the convex structure and the decorative film, applying a pressure of 0.01 Mpa or more to the reflective layer, and imparting a convex structure to the reflective layer. After imparting a convex structure to the reflective layer, the transparent body may or may not be removed. When the transparent body is not removed, the transparent body is disposed, for example, as an outer layer of the decorated molded body.
[0228] <Application> The uses of the decorated molded body obtained as described above are not particularly limited, and the decorated molded body can be used for various articles. Particularly suitable uses of the decorated molded body include the interior and exterior of electronic devices (e.g., wearable devices and smartphones), the interior and exterior of automobiles, the interior and exterior of electrical products, and packaging containers.
[0229] (Decorative panel) The decorative panel according to the present disclosure includes the decorative film according to the present disclosure or a molded product thereof, and preferably includes the decorative film according to the present disclosure. In addition, the decorative panel according to the present disclosure preferably includes the decorative molded body according to the present disclosure. The decorative molded body in the decorative panel is synonymous with the decorative molded body described in the "Decorative Molded Body" section above.
[0230] The decorative panel can be manufactured, for example, by bonding the surface of the reflective layer side of the decorative molded body to the surface of the member that will be the surface layer of the decorative panel. An example of the member that will be the surface layer of the decorative panel is a glass panel. For example, the above-mentioned adhesive layer can be used to bond the decorative molded body to the member that will be the surface layer of the decorative panel. The decorative molded body may be used alone as a decorative panel without combining it with other members.
[0231] An example of the layer structure of the decorative panel will be described with reference to FIG. 6. However, the layer structure of the decorative panel is not limited to the layer structure shown in FIG. 6. FIG. 6 is a schematic cross-sectional view showing an example of a decorative panel according to the present disclosure. The decorative panel 100 shown in FIG. 6 has, in this order, a colored layer 32, a base material 34, a resin layer 36, a cholesteric liquid crystal layer (reflective layer) 40, an alignment layer 38, a transparent body 60 having a convex structure, an adhesive layer 42, and a glass panel 44.
[0232] The shape of the decorative panel is not limited. The shape of the decorative panel may be determined, for example, according to the application. The decorative panel may be, for example, flat. The decorative panel may also have a curved surface.
[0233] The decorative panel can be used, for example, for the interior and exterior of various articles (for example, electronic devices, automobiles, and electrical products). For example, when the decorative panel 100 shown in Fig. 6 is used as a housing for an electronic device, it is preferable to arrange the colored layer 32, the base material 34, the resin layer 36, the cholesteric liquid crystal layer (reflective layer) 40, the alignment layer 38, the transparent body 60 having a convex structure, the adhesive layer 42, and the glass panel 44 from the inside to the outside of the housing. By observing the decorative panel 100 in the direction from the glass panel 44 to the colored layer 32, the user can observe high brilliance and uniform color regardless of the viewing direction.
[0234] (Electronic Devices) The electronic device according to the present disclosure includes the decorative panel according to the present disclosure. Examples of the electronic device include a wearable device and a smartphone. The decorative panel in the electronic device is synonymous with the decorative panel described in the above "Decorative Panel". The decorative panel is preferably used as a housing for the electronic device.
[0235] The method for manufacturing the electronic device is not limited, and a known method can be used. When a decorative panel is used as a housing for the electronic device, various electronic components of the electronic device can be accommodated inside the housing including the decorative panel, thereby manufacturing the electronic device including the decorative panel. EXAMPLES
[0236] The present disclosure will be described in more detail below with reference to examples. The scope of the present disclosure is not limited to the specific examples shown below.
[0237] Example 1 <Preparation of the support> As the supports, two sheets of Cosmoshine (registered trademark) A4100 (PET, thickness: 50 μm, film having an easy-adhesion layer on one side, manufactured by Toyobo Co., Ltd., A4 size) were prepared. Hereinafter, the two supports are referred to as Support 1A and Support 1B, respectively.
[0238] [Composition of Coating Solution 1 for Forming Orientation Layer] Modified polyvinyl alcohol as shown below: 28 parts by weight Citric acid ester (AS3, manufactured by Sankyo Chemical Co., Ltd.): 1.2 parts by mass Photopolymerization initiator (Irgacure 2959, manufactured by BASF): 0.84 parts by weight Glutaraldehyde: 2.8 parts by weight ·Water: 699 parts by mass Methanol: 226 parts by weight
[0239] Modified polyvinyl alcohol (The numbers to the right of each unit in the following compounds indicate the molar ratio.)
[0240] [ka]
[0241] <Preparation of Laminate 1-1> On the surface of the support 1A on which the easy-adhesion layer was not formed, the coating solution 1 for forming an alignment layer was applied by a wire bar coater. Then, the applied coating solution 1 for forming an alignment layer was dried at 100° C. for 120 seconds to prepare an alignment layer 1 having a layer thickness of 0.5 μm.
[0242] The above-prepared alignment layer 1 was subjected to a rubbing treatment (rayon cloth, pressure: 0.1 kgf (0.98 N), rotation speed: 1,000 rpm (revolutions per minute), conveying speed: 10 m / min, number of round trips: 1) in a direction rotated 31.5° counterclockwise from the short side direction of alignment layer 1.
[0243] <Formation of Cholesteric Liquid Crystal Layer 1> The prepared alignment layer 1 was subjected to a rubbing treatment (rayon cloth, pressure: 0.1 kgf (0.98 N), rotation speed: 1,000 rpm (revolutions per minute), conveying speed: 10 m / min, number of reciprocations: 1) in a direction rotated 31.5° counterclockwise from the short side direction of the alignment layer 1. The components contained in the coating solution 1 for forming a cholesteric liquid crystal layer shown below were stirred and dissolved in a container kept at 25° C. to prepare the coating solution 1 for forming a cholesteric liquid crystal layer (liquid crystal composition 1).
[0244] [Composition of Coating Solution 1 for Forming Cholesteric Liquid Crystal Layer] Methyl ethyl ketone: 150.6 parts by weight ·Liquid crystal compound 1 (rod-shaped liquid crystal compound): 92 parts by mass Photopolymerization initiator A (IRGACURE 907, manufactured by BASF): 0.50 parts by mass Chiral agent A: 4.00 parts by weight Chiral agent B: 4.00 parts by weight The following surfactant F1: 0.027 parts by weight
[0245] Liquid crystal compound 1 (monofunctional): The following rod-shaped liquid crystal compound. In the case of radical polymerization, even if an oxetanyl group (cationically polymerizable functional group) is attached, it is defined as monofunctional because it has only one acryloxy group (radical polymerizable group). The same applies to cationic polymerization.
[0246] [ka]
[0247] Chiral agent A (bifunctional): the following compound
[0248] [ka]
[0249] Chiral agent B (zero functionality): the following compound. In the following compound, Bu represents an n-butyl group.
[0250] [ka]
[0251] Surfactant F1: The following compound
[0252] [ka]
[0253] The prepared cholesteric liquid crystal layer forming coating solution 1 was applied to the rubbed surface of the alignment layer 1 using a wire bar coater, and dried at 85° C. for 120 seconds. The exposure dose for the surface of the cholesteric liquid crystal layer of the formed laminate was 70 mJ / cm 2 . 2 A laminate 1-1 was formed by forming a cholesteric liquid crystal layer 1 having a thickness of 3.0 μm through exposure to (i-line). The laminate 1-1 has a support 1A, an alignment layer 1, and a cholesteric liquid crystal layer 1 in this order.
[0254] <Preparation of Laminate 1-2> An acrylic adhesive (SK Dyne SG-50Y, manufactured by Soken Chemical & Engineering Co., Ltd.) was applied to the surface of the separately prepared Cosmoshine (registered trademark) A4100 (i.e., support 1B) on which the easy-adhesion layer was formed, using a comma coater, and dried at 120°C for 2 minutes to form a resin layer 1 (adhesive layer) with a layer thickness of 20 μm, thereby forming a laminate 1-2. The laminate 1-2 has a support 1B and a resin layer 1.
[0255] <Preparation of Laminate 1-3> The laminate 1-1 and the laminate 1-2 were laminated together using a laminator so that the resin layer 1 and the cholesteric liquid crystal layer 1 were in contact with each other. The PET film on the laminate 1-1 side (i.e., the support 1A) was peeled off to obtain a laminate 1-3 in which the support 1B / resin layer 1 / cholesteric liquid crystal layer 1 / alignment layer 1 were laminated in this order.
[0256] <Preparation of black pigment dispersion> Carbon black, dispersant, polymer, and solvent were mixed to obtain the following black pigment dispersion composition, and a black pigment dispersion was obtained using a triple roll mill and a bead mill. The average particle size of the carbon black measured using a Microtrac FRA (Honeywell) was 163 nm.
[0257] -Composition of black pigment dispersion- Resin-coated carbon black prepared according to the description in paragraphs 0036 to 0042 of Japanese Patent No. 5320652: 20.0% by mass Dispersant 1 (structure below): 1.0% by mass Polymer (random copolymer of benzyl methacrylate / methacrylic acid = 72 / 28 (molar ratio), weight average molecular weight: 30,000): 6.0% by mass Propylene glycol monomethyl ether acetate: 73.0% by mass
[0258] [ka]
[0259] <Composition of Coating Solution 1 for Forming Colored Layer> Black pigment dispersion: 30 parts by weight Polymerizable compound 1: Urethane acrylate oligomer, CN-996NS, manufactured by Sartomer Japan Co., Ltd.: 25 parts by mass Binder resin 3: urethane modified acrylic polymer (containing polyol) 35% by weight ethyl acetate / ethyl methyl ketone / isopropyl alcohol solution: 25 parts by weight Photopolymerization initiator (Irgacure 2959, manufactured by BASF): 1.0 part by mass Methyl ethyl ketone: 19 parts by weight
[0260] <Preparation of Laminate 1> The coating solution 1 for forming a colored layer was applied onto the support 1B of the laminate 1-3 using a wire bar coater, and dried for 10 minutes at 100° C. The exposure dose for the surface of the colored layer of the formed laminate was 500 mJ / cm 2 . 2 The entire surface was exposed to light (i-line) to form a colored layer 1 (black colored layer) having a layer thickness of 4 μm, thereby forming a laminate 1. The laminate 1 has a colored layer 1, a support 1B, a resin layer 1, a cholesteric liquid crystal layer (reflective layer) 1, and an alignment layer 1 in this order.
[0261] <Molding process> The surface of the alignment layer 1 of the laminate 1 was subjected to corona treatment using a tabletop corona treatment device (TEC-8XA, manufactured by Kasuga Electric Co., Ltd., set output 70 W, operation speed 1 m / min, number of times: 5 reciprocations), and then a transparent body having a convex pattern (thickness 2 mm, width 50 mm, length 50 mm) was used as a mold, and the surface of the alignment layer 1 of the laminate 1 was brought into contact with the convex surface of the transparent body, and a molded body 1 (i.e., a decorated molded body) was obtained by performing a pressure molding process (TOM molding). The convex pattern had the shape described in Example 1 of Table 1. For the pressure molding process, a TOM molding machine NGF-0510-R (manufactured by Fuse Vacuum Co., Ltd.) was used, the molding temperature was 120°C, and the stretch ratio was 30% at the highest part. The pressure in the pressure molding process was 0.3 MPa.
[0262] <Average positive slope Φ AVE Measurements > The decorative film was cut using a microtome (e.g., RX-860, manufactured by Yamato Koki Kogyo Co., Ltd.) in any plane (360° in all) perpendicular to the surface direction of the decorative film. The cutting direction can be predicted to some extent by observing the surface of the decorative film with a microscope (BX53M, manufactured by Olympus Corporation). The cut cross section was observed with a scanning electron microscope (SU3800, manufactured by Hitachi High-Tech Corporation) to measure the cross-sectional shape and obtain the Φ AVE was calculated.
[0263] <Performance evaluation> -Color change for each viewing direction (evaluation of the change in brightness when rotated horizontally on a table)- The reflectance was measured in the wavelength range of 380 nm to 780 nm using an ultraviolet-visible-near infrared spectrophotometer (JASCO Corp., V-750) and an automatic absolute reflectance measurement unit (JASCO Corp., ARMV-919). The reflectance indicates the maximum value of the reflection spectrum when the horizontal axis is the wavelength and the vertical axis is the reflectance. The reflectance when the molded body was set in the sample holder so that the first direction was the incident surface was defined as the highlight reflectance (R H ), and the reflectance when the same area is set so that the second direction is the incident surface is called the shade reflectance (R S The ratio of the reflectances (R H / R S The incidence angle and the acceptance angle were set within the range of 0° to -45° and the acceptance angle -90° to 90°, and the reflectance ratio (R H / R S ) is the angle at which it is largest. The angle is an absolute angle with the perpendicular line to the substrate plane taken as 0°. The color change for each viewing direction was evaluated according to the following criteria. As an evaluation result, C is preferable, B is more preferable, and A is particularly preferable. <<Evaluation criteria>> A: Highlight reflectance (R H ) and shade reflectance (R S ) and the ratio (R H / R S ) is 100 or more B: Highlight reflectance (R H ) and shade reflectance (R S ) and the ratio (R H / R S ) is 10 or more and less than 100 C: Highlight reflectance (R H ) and shade reflectance (R S ) and the ratio (R H / R S ) is 1.2 or more and less than 10 D: Highlight reflectance (R H ) and shade reflectance (R S ) and the ratio (R H / R S ) is less than 1.2
[0264] -Evaluation of in-plane brightness contrast (evaluation of brightness difference within the plane when viewed from any one direction)- Observe from any direction, and define the brightest area as A and the darkest area as B. The reflectance when area A is set in the sample holder so that the first direction is the incident surface is called the highlight reflectance (R H ), The reflectance when area B is set so that the first direction of area A is the incident surface is called the shade reflectance (R S )year, The reflectance ratio (R H / R S ) was measured. The in-plane light-dark contrast was evaluated according to the following criteria. As an evaluation result, C is preferable, B is more preferable, and A is particularly preferable. <<Evaluation Criteria>> A: Highlight reflectance (R H ) and shade reflectance (R S ) and the ratio (R H / R S ) is 100 or more B: Highlight reflectance (R H ) and shade reflectance (R S ) and the ratio (R H / R S ) is 10 or more and less than 100 C: Highlight reflectance (R H ) and shade reflectance (R S ) and the ratio (R H / R S ) is 1.2 or more and less than 10 D: Highlight reflectance (R H ) and shade reflectance (R S ) and the ratio (R H / R S ) is less than 1.2
[0265] - Evaluation of sparkling brilliance (evaluation of the steepness of the change in brightness when viewed from any one direction) - The reflectance was measured under the following conditions for two regions A and B on either side of the boundary where the reflectance changes sharply. The reflectance when region A is set in the sample holder so that the first direction is the incident surface is called the highlight reflectance (R H )year, The reflectance when region B is set in the sample holder so that the first direction of region A is the incident surface is called the shade reflectance (R S )year, The reflectance ratio (R H / R S ) was measured. In addition, the distance between region A and region B was measured. The glittering shine was evaluated from A to D according to the following criteria. A: Highlight reflectance (R H ) and shade reflectance (R S ) and the ratio (R H / R S ) is 100 or more and the distance between the regions is 1 mm or less B: Highlight reflectance (R H ) and shade reflectance (R S ) and the ratio (R H / R S ) is 10 or more and less than 100, and the distance between the regions is 1 mm or less C: Highlight reflectance (R H ) and shade reflectance (R S ) and the ratio (R H / R S ) is 1.2 or more and less than 10, and the distance between the regions is 1 mm or less D: Highlight reflectance (R H ) and shade reflectance (R S ) and the ratio (R H / R S ) is less than 1.2 or the distance between the regions is greater than 1 mm
[0266] -Evaluation of the brightness when tilted in the hand (evaluation of the difference in brightness when viewed from a low angle)- The reflectance ratio (R H / R S ) was measured. The glittering sensation when held in the hand and tilted was evaluated according to the following criteria. A: Highlight reflectance (R H ) and shade reflectance (R S ) and the ratio (R H / R S ) is 100 or more B: Highlight reflectance (R H ) and shade reflectance (R S ) and the ratio (R H / R S ) is 10 or more and less than 100 C: Highlight reflectance (R H ) and shade reflectance (R S ) and the ratio (R H / R S ) is 1.2 or more and less than 10 D: Highlight reflectance (R H ) and shade reflectance (R S ) and the ratio (R H / R S ) is less than 1.2
[0267] - Evaluation of the brightness on a table (evaluation of the difference in brightness at the observation angle assumed for decorative use) - The ratio of reflectance (R H / R S ) was measured. The brightness on the table was evaluated according to the following criteria. A: Highlight reflectance (R H ) and shade reflectance (R S ) and the ratio (R H / R S ) is 100 or more B: Highlight reflectance (R H ) and shade reflectance (R S ) and the ratio (R H / R S ) is 10 or more and less than 100 C: Highlight reflectance (R H ) and shade reflectance (R S ) and the ratio (R H / R S ) is 1.2 or more and less than 10 D: Highlight reflectance (R H ) and shade reflectance (R S ) and the ratio (R H / R S ) is less than 1.2
[0268] -Evaluation of brightness when viewed from the front (evaluation of brightness difference when viewed from directly in front)- The reflectance ratio (R H / R S ) was measured. The brightness as viewed from the front was evaluated according to the following criteria. A: Highlight reflectance (R H ) and shade reflectance (R S ) and the ratio (R H / R S ) is 100 or more B: Highlight reflectance (R H ) and shade reflectance (R S ) and the ratio (R H / R S ) is less than 100
[0269] -Evaluation of visibility of convex structures- The obtained molded body was visually inspected and evaluated for visibility of the convex structure. A: The shape of the convex structure is not visible. B: The shape of the convex structure is visible.
[0270] -Rainbow unevenness caused by interference- The obtained molded body was visually inspected to evaluate whether or not rainbow color unevenness was visible. A: No visible rainbow unevenness B: Rainbow-colored unevenness is visible
[0271] - Viewing angle dependence of color change (evaluation of whether a large color change occurs depending on the viewing angle) - The obtained molded article was evaluated for changes in color when viewed from angles of 0° and 45° (for example, yellow at 0° and blue at 45°). A: There is a large change in color when viewed from a 0° angle and when viewed from a 45° angle. B: A slight change in color is observed when viewed from a 0° direction and a 45° direction.
[0272] The evaluation results are shown in Tables 1 and 2.
[0273] (Examples 2 to 11) Evaluation was carried out using molded bodies 2 to 11 obtained by changing the convex pattern in Example 1. The evaluation results of Examples 2 to 11 are shown in Table 2. In Example 11, the reflective layer was prepared by the following method. A niobium oxide film was formed to a thickness of 100 nm on the convex surface of the substrate having a convex shape using a sputtering film forming device (e.g., RAS-1100C manufactured by Shincron Co., Ltd.). A silicon oxide film was formed to a thickness of 100 nm on the niobium oxide layer. The process of alternately forming niobium oxide and silicon oxide films was repeated until a total of eight layers were laminated to a thickness of 800 nm, and a molded body was obtained. The molded body had a substrate having a convex pattern and a reflective layer.
[0274] Comparative Example 1 A molded body 12 was produced in the same manner as in Example 1, except that the coating solution 1 for forming a cholesteric liquid crystal layer was not applied to the surface of the alignment layer 1 that had been rubbed in Example 1, and a cholesteric liquid crystal layer was not formed.
[0275] Comparative Example 2 Instead of the transparent body having a convex pattern, a (smooth) PET substrate (A4300, manufactured by Toyobo Co., Ltd., thickness 50 μm) having no convex pattern was used to produce a molded body 13.
[0276] (Comparative Examples 3 and 4) The cross-sectional shape of the convex structure of the transparent body was changed to the conditions in Table 1 to produce molded bodies 14 and 15, respectively.
[0277] The evaluation results of Comparative Examples 1 to 4 are shown in Table 1.
[0278] [Table 1]
[0279] [Table 2]
[0280] As shown in Tables 1 and 2, the decorative films of Examples 1 to 11, which are the decorative films according to the present disclosure, were decorative films with a richer change in color depending on the viewing direction than the decorative films of Comparative Examples 1 to 4.
[0281] (Example 12: Film for display decoration) In Example 1, the prepared coating solution 1 for forming a cholesteric liquid crystal layer was applied to the surface of the alignment layer 1 that had been subjected to the rubbing treatment using a wire bar coater, and dried at 85° C. for 120 seconds. Then, the coating solution was exposed to a 30 mJ / cm 2 beam through a mask pattern shown in FIG. 2 A molded body A-1 was produced in the same manner as in Example 1, except that the liquid crystal layer was irradiated with light from a metal halide lamp (MAL625NAL manufactured by GS Yuasa Corp.) with an exposure dose of 100 nm to perform an isomerization process of the reflection wavelength, and that a black layer was not formed. After the above process, the liquid crystal layer exhibited a reflection pattern with a blue to red gradation color. Furthermore, on the surface of the substrate opposite to the surface on which the liquid crystal layer was formed, a retardation layer of a quarter-wave plate was transferred to the cholesteric liquid crystal layer by the method described in paragraphs 0170 to 0171 of JP 2017-215558 A, to form a molded body A-2. Furthermore, using the method described in paragraphs 0170 to 0171 of JP 2017-215558 A, a retardation layer of a quarter-wave plate was transferred to the transparent body having the linear convex pattern (A) (the smooth surface side without the convex pattern) and laminated to form molded body A-3. In this case, each of the quarter-wave plates was positioned so that the transmittance was maximized when linearly polarized light was transmitted through the liquid crystal layer. Furthermore, an acrylic adhesive (SK Dyne SG-50Y, manufactured by Soken Chemical Engineering Co., Ltd.) was applied using a comma coater onto the retardation layer of the 1 / 4 wavelength plate laminated on the transparent body side having the linear convex pattern (A), and dried at 120°C for 2 minutes to form a resin layer A-4 (adhesive layer) with a layer thickness of 20 μm. Furthermore, a liquid crystal axially symmetric polarization converter (RADPOL4, manufactured by ARCoptix) was rubbed on the resin layer A-4 with a silicone rubber roller at room temperature and bonded to the resin layer A-4 to form a molded body A-5.
[0282] Molded body A-5 was placed on the display of an iPad Pro (liquid crystal display, manufactured by Apple Inc.) with the liquid crystal axially symmetrical polarization converter on the top surface. In this case, it was placed in the direction that maximized the transmittance of the linearly polarized light output from the display. When the display was ON, if the transmitted light of the liquid crystal axially symmetrical converter was set to be linearly polarized, the image displayed on the display was clearly visible, and the pattern of the decorative film was hardly visible. On the other hand, when the display was OFF, if the liquid crystal axially symmetrical converter was set to transmit all light, the reflected color of the decorative film (gradation from blue to red) was clearly visible, and a pattern with high brilliance and rich changes in reflected color depending on the viewing angle was visible. [Explanation of symbols]
[0283] 20:Decorative film 22: Base material 24: Colored layer 26: Orientation layer 28: Cholesteric liquid crystal layer (reflective layer) 30: Adhesive layer 32: Colored layer 34: Base material 36: Resin layer 38: Orientation layer 40: Cholesteric liquid crystal layer (reflective layer) 42: Adhesive layer 44: Glass panel 50:Decorative film 60: Transparent body with uneven structure 70: Decorative molding 80: Decorative molding 90: Decorative molding 100:Decorative panel 110:1 / 4 wave plate retardation layer 112:1 / 4 wave plate retardation layer 114: Adhesive layer 116: Decorative molding
[0284] The disclosures of Japanese Patent Application No. 2020-129501, filed on July 30, 2020, and Japanese Patent Application No. 2020-215029, filed on December 24, 2020, are incorporated by reference in their entireties into this specification. All publications, patent applications, and technical standards mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, or technical standard was specifically and individually indicated to be incorporated by reference. < / a8> < / a1> < / a7> < / a1> < / a6> < / a1>
Claims
1. A substrate; A reflective layer having a convex structure on a surface thereof, In a cross section obtained by cutting the convex structure in a direction perpendicular to the surface direction of the decorative film, the average positive inclination angle Φ AVE The direction in which the angle is the largest is taken as the first direction, and the average positive tilt angle Φ AVE When the direction in which is the smallest is defined as the second direction, Φ AVE is 3° or more, and Φ in the second direction AVE has an area A smaller than 3°; In a cross-sectional shape obtained by cutting the convex structure in the region A in a direction perpendicular to the surface direction of the decorative film and in the first direction, the area ratio of a region having an inclination angle Φ of 3° or more and less than 45° is 65% or more and 90% or less with respect to the total area of the region A, In a cross-sectional shape obtained by cutting the convex structure in the region A in a direction perpendicular to the surface direction of the decorative film and in the first direction, the area ratio of a region having an inclination angle Φ of 3° or more and less than 7° is 40% or more and 60% or less, the convex structure is a linear convex structure, The linear convex structure includes a linear convex structure having a ratio L / W of a length L to an average line width W of 5 or more. Decorative film.
2. The decorative film according to claim 1 , wherein the region A in the surface direction of the decorative film includes a region having a size equal to or larger than a circle having a radius of 150 μm.
3. The decorative film according to claim 1 or 2, further comprising an area B in the plane, the area B being different from the area A in the second direction.
4. The decorative film according to claim 3 , wherein a distance between the region A and the region B in a surface direction of the decorative film is 1 mm or less.
5. In a cross-sectional shape obtained by cutting the convex structure in the region A in a direction perpendicular to the surface direction of the decorative film and in the first direction, a middle height point H between the maximum point and the minimum point of the positive inclination angle 1/2 The inclination angle Φ 1/2 The decorative film according to any one of claims 1 to 4, wherein the angle is 3° or more and less than 60°.
6. In a cross-sectional shape obtained by cutting the convex structure in the region A in a direction perpendicular to the surface direction of the decorative film and in the first direction, a middle height point H between the maximum point and the minimum point of the positive inclination angle 1/2 The inclination angle Φ 1/2 The decorative film according to any one of claims 1 to 4, wherein the angle is 60° or more.
7. The decorative film according to any one of claims 1 to 6, wherein in a cross-sectional shape of the convex structure in the region A cut in a direction perpendicular to the surface direction of the decorative film and in the first direction, the area ratio of the region having an inclination angle Φ of 0° or more and less than 3° is 50% or less of the total area of the region A.
8. The decorative film according to any one of claims 1 to 7, wherein in a cross-sectional shape obtained by cutting the convex structure in the region A in a direction perpendicular to the surface direction of the decorative film and in the first direction, the distance between the minimum points of the positive inclination angle is less than 100 μm.
9. The decorative film according to any one of claims 1 to 8, wherein in a cross-sectional shape obtained by cutting the convex structure in the region A in a direction perpendicular to the surface direction of the decorative film and in the first direction, the distance between the minimum points of the positive inclination angle is 10 μm or more.
10. The decorative film according to any one of claims 1 to 9, wherein the reflective layer contains liquid crystal in a cholesteric orientation state.
11. A decorated molded body comprising the decorative film according to any one of claims 1 to 10 or a molded product thereof.
12. A decorative panel comprising the decorative film according to any one of claims 1 to 10 or a molded product thereof.
13. An electronic device comprising the decorative panel according to claim 12.
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