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Title:
LIGHT-TRANSMISSIVE DECORATIVE FILM, MOLDED ARTICLE CONTAINING LIGHT-TRANSMISSIVE DECORATIVE FILM, PRODUCTION METHOD THEREOF, AND LIGHTING DISPLAY DEVICE
Document Type and Number:
WIPO Patent Application WO/2019/092582
Kind Code:
A1
Abstract:
A decorative film which can provide a design that changes due to light in the ambient environment and light from a light source disposed behind the decorative film, and can be used in a molding method of covering an article having a three-dimensional shape by heat-stretching. The light-transmissive decorative film according to an embodiment of the present disclosure, which can cover an article having a three-dimensional shape by heat-stretching, includes an upper design layer having optical transparency, a reflective layer, and a lower design layer having optical transparency in this order, and the OD value of the reflective layer is from 0.7 to 1.7.

Inventors:
SHIBAHARA, Norihito (6-7-29 Kitashinagawa, Shinagawa-Ku, Tokyo, 〒141-8684, JP)
KUSUMOTO, Ayako (6-7-29 Kitashinagawa, Shinagawa-Ku, Tokyo, 〒141-8684, JP)
SAKAI, Rie (6-7-29 Kitashinagawa, Shinagawa-Ku, Tokyo, 〒141-8684, JP)
Application Number:
IB2018/058680
Publication Date:
May 16, 2019
Filing Date:
November 05, 2018
Export Citation:
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Assignee:
3M INNOVATIVE PROPERTIES COMPANY (3M Center, Post Office Box 33427Saint Paul, Minnesota, 55133-3427, US)
International Classes:
B32B15/08; B32B15/20; B32B25/14; B32B27/08; B32B27/30; B32B27/32; B32B27/36; B32B27/40; B32B3/26
Attorney, Agent or Firm:
KNECHT, Harold C., III, et al. (3M Center, Office of Intellectual Property CounselPost Office Box 3342, Saint Paul Minnesota, 55133-3427, US)
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Claims:
Claims

1. A light-transmissive decorative film capable of covering an article having a

three-dimensional shape by heat-stretching, the light-transmissive decorative film comprising an upper design layer having optical transparency, a reflective layer, and a lower design layer having optical transparency in this order, wherein an OD value of the reflective layer is from 0.7 to 1.7.

2. The light-transmissive decorative film according to claim 1, wherein a first design produced by the upper design layer is visible in daylight, and a second design produced by a combination of the upper design layer and the lower design layer is visible in the presence of light passing through the lower design layer, the reflective layer, and the upper design layer in this order.

3. The light-transmissive decorative film according to claim 1 or 2, wherein a storage modulus is from 1 χ 106 Pa to 1.5 χ 108 Pa within a temperature range of from 1 10°C to 150°C when measured in a tension mode at a frequency of 10 Hz.

4. The light-transmissive decorative film according to claim 1 or 2, wherein a storage modulus is from 1 χ 105 Pa to 2 χ 108 Pa within a temperature range of from 1 15°C to 140°C when measured in a tension mode at a frequency of 10 Hz.

5. The light-transmissive decorative film according to any one of claims 1 to 4, wherein the reflective layer comprises a vapor-deposited layer containing tin, indium, or a combination thereof.

6. The light-transmissive decorative film according to any one of claims 1 to 5, wherein the upper design layer comprises a first resin layer and a surface layer, and the lower design layer comprises a second resin layer and a pattern layer.

7. The light-transmissive decorative film according to any one of claims 1 to 6, wherein the reflective layer has an uneven surface.

8. The light-transmissive decorative film according to any one of claims 1 to 7, further comprising a third resin layer configured to support the reflective layer on a surface thereof.

9. The light-transmissive decorative film according to claim 8, wherein the third resin layer has an uneven surface.

10. The light-transmissive decorative film according to any one of claims 1 to 9, wherein a total light transmittance at a wavelength of from 400 to 700 nm is not greater than 3%.

11. The light-transmissive decorative film according to any one of claims 1 to 9, wherein a total light transmittance at a wavelength of from 400 to 700 nm is not greater than 12%.

12. The light-transmissive decorative film according to any one of claims 1 to 11, wherein a total light transmittance of a combination of the upper design layer and the reflective layer at a wavelength of from 400 to 700 nm is not greater than 12%.

13. A molded article comprising a substrate and the light-transmissive decorative film according to any one of claims 1 to 12 configured to cover the substrate.

14. The molded article according to claim 13, wherein a first design produced by the upper design layer is visible in daylight, and a second design produced by a combination of the upper design layer, the substrate, and the lower design layer is visible in the presence of light passing through the substrate, the lower design layer, the reflective layer, and the upper design layer in this order. 15. The molded article according to claim 13 further comprising an adhesive layer between the light-transmissive decorative film and the substrate, wherein a first design produced by the upper design layer is visible in daylight, and a second design produced by a combination of the upper design layer, the substrate, the adhesive layer, and the lower design layer is visible in the presence of light passing through the substrate, the adhesive layer, the lower design layer, the reflective layer, and the upper design layer in this order.

16. The molded article according to any one of claims 13 to 15, wherein the substrate has unevenness on a surface on an opposite side to the light-transmissive decorative film. 17. A production method for a molded article comprising: preparing the light-transmissive decorative film according to any one of claims 1 to 12 and a substrate; and applying the light-transmissive decorative film to a surface of the substrate by a three-dimensional heat-stretching molding method to form a molded article in which the substrate is covered with the

light-transmissive decorative film.

18. A lighting display device comprising: the molded article according to any one of claims 13 to 16; and a light source disposed on a lower design layer side, when seen from the reflective layer of the light-transmissive decorative film.

19. The lighting display device according to claim 18, wherein an illuminance on a measurement surface 15 cm vertically away from a center of a surface of the molded article is from 0.5 lm/m2 to 45 lm/m2.

20. The lighting display device according to claim 18 or 19, wherein an illuminance of the light source on a measurement surface 15 cm vertically away from a light-emitting surface of the light source is from 0.5 lm/m2 to 300 lm/m2.

Description:
LIGHT-TRANSMISSIVE DECORATIVE FILM, MOLDED ARTICLE CONTAINING LIGHT-TRANSMISSIVE DECORATIVE FILM, PRODUCTION METHOD THEREOF,

AND LIGHTING DISPLAY DEVICE

TECHNICAL FIELD

The present disclosure relates to a light-transmissive decorative film, a molded article containing a light-transmissive decorative film, a production method thereof, and a lighting display device.

BACKGROUND ART

Decorative films of diverse designs are used across a wide range of fields of interior materials of automobiles and the like. As one mode of a design of a decorative film, a decorative film has been proposed in which a pattern of a light-transmissive part is visible when illuminated with a light source from behind, but in a state not illuminated by a light source from behind, the pattern of the light-transmissive part blends in with a surrounding light-blocking part and becomes invisible.

JP 2001-347539 A describes "a back-lightable decorative molded article in which an insert film or a transfer layer is formed integrally with a light-transmissive molded article surface and has at least one light-transmissive part and a light-blocking part adjacent to the

light-transmissive part, the decorative molded article being formed by successively laminating, on the light-transmissive molded article surface from a viewing side, a light-blocking layer formed on only the light-blocking part and a colored light-transmissive layer formed on at least the light-transmissive part in a region in the vicinity of at least one light-transmissive part; wherein the following relational formulas ( 1) to (3) hold for a color difference ΔΕ when the chromaticity of the light-transmissive part and the light-blocking part in the region is measured from the viewing side using the CIE (International Commission on Illumination) 1976 L*a*b color system as well as the value Xi (%) of the light transmittance of all layers including the molded article positioned on the light-transmissive part in the region and the maximum value X2 (%) of the light transmittance of all layers including the molded article positioned on the light-blocking part in the region measured with JIS K 7105; and relational formula (4) additionally holds when there is a portion in which the colored light-transmissive layer is not formed on the light-blocking part in the region. ΔΕ<50... (1) 3<Xi<70... (2) 4X 2 ≤Xi... (3) X 2 <10... (4)"

SUMMARY OF THE INVENTION

The demand for diversity in designs in decorative films is increasing further. In particular, there is a demand for a decorative film capable of providing a highly designable appearance which changes when placed in an environment in which light such as daylight is incident on the decorative film surface without the film being illuminated with a light source from behind and when placed in a dark location and illuminated with a light source from behind. When such a decorative film is applied to an article having a three-dimensionally curved face such as a molded article containing a material such as plastic, for example, the decorative film is preferably able to conform to the curved face well without any loss in design.

The present disclosure provides a decorative film which can provide a design that changes due to light in the ambient environment and light from a light source disposed behind the decorative film, and can be used in a molding method of covering an article having a three-dimensional shape by heat-stretching (called a "three-dimensional heat-stretching molding method" hereafter).

One embodiment of the present disclosure provides a light-transmissive decorative film capable of covering an article having a three-dimensional shape by heat-stretching, the light-transmissive decorative film including an upper design layer having optical transparency, a reflective layer, and a lower design layer having optical transparency in this order, wherein an OD value of the reflective layer is from 0.7 to 1.7.

Another embodiment of the present disclosure provides a molded article including a substrate and the light-transmissive decorative film configured to cover the substrate.

Yet another embodiment of the present disclosure provides a production method for a molded article including: preparing the light-transmissive decorative film described above and a substrate and applying the light-transmissive decorative film to a surface of the substrate by a three-dimensional heat-stretching molding method to form a molded article in which the substrate is covered with the light-transmissive decorative film.

Yet another embodiment of the present disclosure provides a lighting display device including the molded article described above and a light source disposed on the lower design layer side when seen from the reflective layer of the light-transmissive decorative film described above.

The present disclosure provides a decorative film which can provide a design that changes due to light in the ambient environment and light from a light source disposed behind the decorative film, and can be suitably used in a three-dimensional heat-stretching molding method.

The above descriptions should not be construed to be a disclosure of all of the embodiments and benefits of the present invention.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic cross-sectional view of a light-transmissive decorative film according to an embodiment of the present disclosure.

FIG. 2A is a schematic cross-sectional view of a molded article and lighting display device to which a light-transmissive decorative film according to an embodiment of the present disclosure is attached, illustrating a view when observed in a state in which a light source is off. FIG. 2B is a schematic cross-sectional view of a molded article and lighting display device to which a light-transmissive decorative film according to an embodiment of the present disclosure is attached, illustrating a view when observed in a state in which a light source is on.

FIG. 3 is a cross-sectional view of a light-transmissive decorative film according to another embodiment of the present disclosure.

FIG. 4A is a schematic cross-sectional view of a molded article and lighting display device to which a light-transmissive decorative film according to another embodiment of the present disclosure is attached, illustrating a view when observed in a state in which a light source is off.

FIG. 4B is a schematic cross-sectional view of a molded article and lighting display device to which a light-transmissive decorative film according to another embodiment of the present disclosure is attached, illustrating a view when observed in a state in which a light source is off.

FIG. 5 A is a photograph illustrating the appearance of a molded article to which the light-transmissive decorative film of Example 2 is attached in daylight.

FIG. 5B is a photograph illustrating the appearance of a molded article to which the light-transmissive decorative film of Example 2 is attached when irradiated with light from behind.

DESCRIPTION OF EMBODIMENTS

For the purpose of illustrating typical embodiments of the present invention, typical embodiments of the present invention are described in detail below, referring to the drawings, but the present invention is not limited to these embodiments. Regarding the reference numerals in the drawings, constituents labeled with similar numbers across different drawings are similar or corresponding constituents.

In the present disclosure, the term "film" encompasses articles referred to as "sheets".

In the present disclosure, the term "storage modulus" is the storage modulus E' when viscoelasticity measurement is performed in tension mode at a frequency of 10 Hz using a dynamic viscoelastic analyzer.

In the present disclosure, the term "(meth)acrylic" means "acrylic or methacrylic", and the term "(meth)acrylate" means "acrylate or methacrylate".

In the present disclosure, when describing the "total light transmittance" mentioned with regard to the light-transmissive decorative film and components thereof (for example, the upper design layer, a combination of the upper design layer and the reflective layer, the lower design layer, the surface layer, or the like) as well as a molded article, this refers to the maximum total light transmittance measured in portions where the light-transmissive decorative film functions effectively in each component - that is, the maximum total light transmittance measured in regions including a first design and/or a second design. For example, the total light transmittance of a light-transmissive decorative film or the total light transmittance of a molded article to which a light-transmissive decorative film is attached refers to the maximum value measured in regions including a first design and/or a second design. On the other hand, the total light transmittance of only the upper design layer and the reflective layer refers to the maximum value measured in a region including a first design. In the present disclosure, the wavelength range in the visible range is not particularly limited, but the "total light transmittance in the visible range" refers to the total light transmittance at 400 nm to 700 nm.

In the present disclosure, the three-dimensional heat-stretching molding method includes a "three-dimensional overlay method" (TOM). In the present disclosure, the term,

"three-dimensional overlay method" refers to a molding method including a process of preparing a film and a three-dimensional article; a process of disposing the film and the article in a vacuum chamber having in the interior thereof a heating device, wherein the film separates the interior space of the vacuum chamber into two and the article is disposed in one of the separated interior spaces; a process of heating the film by the heating device; a process of putting both the interior space in which the article is disposed and the interior space on the opposite side thereof in a vacuum atmosphere; and a process of making the article and the film contact with each other to cover the article with the film while putting the interior space in which the article is disposed in a vacuum atmosphere and putting the interior space on the opposite side thereof in a pressurized atmosphere or normal -pressure atmosphere.

The light-transmissive decorative film according to an embodiment of the present disclosure includes an upper design layer having optical transparency, a reflective layer, and a lower design layer having optical transparency in this order, wherein the OD value of the reflective layer is from approximately 0.7 to approximately 1.7. The light-transmissive decorative film can be suitably used in a three-dimensional heat-stretching molding method such as insert molding or TOM.

FIG. 1 illustrates a cross-sectional view of a light-transmissive decorative film 10 according to an embodiment of the present disclosure. The decorative film 10 includes, in this order, an upper design layer 12 having optical transparency, a reflective layer 14, and a lower design layer 16 having optical transparency. The decorative film 10 may further include, as optional components, additional layers such as a bonding layer for bonding the layers forming the decorative film together, a primer layer, a release liner, an adhesive layer for attaching the decorative film to a substrate, and the like. In FIG. 1, an adhesive layer 18 is illustrated as an optional component. In one embodiment, as illustrated in FIG. 1, the upper design layer 12 includes a first resin layer 122 and a surface layer 124, and the lower design layer 16 includes a second resin layer 162 and a pattern layer 164.

FIG. 2A is a schematic cross-sectional view of a molded article 20 in which the light-transmissive decorative film 10 is attached to a substrate 22, and a lighting display device including the molded article 20 and a light source 32. In FIG. 2A, the light source 32 is off, and light incident from the upper side of the light-transmissive decorative film 10 in daylight is reflected by the reflective layer 14 so that a design (first design) produced by the upper design layer 12 is visible to an observer.

FIG. 2B is a schematic cross-sectional view of a molded article 20 and a lighting display device 30 with the same configuration as in FIG. 2A, wherein the light source 32 is on. When the vicinity of the lighting display device is dark, the amount of light incident on the upper surface of the light-transmissive decorative film 10 is small, and the amount of light incident on the lower surface of the light-transmissive decorative film 10 from the light source 32 is large. Therefore, as a result of light from the light source 32 passing through the lower design layer 16, the reflective layer 16, and the upper design layer 12 - that is, due to the presence of light passing through the lower design layer 16, the reflective layer 14, and the upper design layer 12 in this order - a design (second design) produced by a combination of the upper design layer 12 and the lower design layer 16 is visible to the observer.

The reflective layer 14 has an OD value of from approximately 0.7 to approximately 1.7 and is designed so as to reflect light incident from the upper surface of the light-transmissive decorative film 10 in daylight and to transmit at least a portion of light incident from the lower surface of the light-transmissive decorative film 10. In this way, it is possible to provide a highly designable appearance of two types that change when the light-transmissive decorative film is placed in daylight without being illuminated by a light source from behind and when placed in a dark environment and illuminated with a light source from behind.

In FIGS. 1, 2 A, and 2B, the reflective layer 14 is illustrated as a layer having a substantially smooth surface, but the reflective layer 14 may have an uneven surface. In this embodiment, an appearance with a visual effect abounding in change in daylight, in particular, can be obtained. A schematic cross-sectional view of the light-transmissive decorative film of this embodiment is illustrated in FIG. 3, wherein the reflective layer 14 is illustrated as a layer having an uneven surface.

The upper design layer and the lower have optical transparency. These design layers may include optically transparent regions and may include one or a plurality of non-optically transparent regions.

In this embodiment, the entire upper design layer is translucent or transparent. In some embodiments, the total light transmittance in the visible range of the upper design layer is not less than approximately 1%, not less than approximately 2%, or not less than approximately 3% and not greater than approximately 70%, not greater than approximately 60%, or not greater than approximately 50%. In the present disclosure, the total light transmittance is determined in accordance with JIS K 736-1 : 1997 (ISO 13468-1 : 1996). As a result of the total light transmittance of the upper design layer being within the range described above, the visibility of the second design when illuminated by a light source from behind can be increased. In some embodiments, the total light transmittance in the visible range of the combination of the upper design layer and the reflective layer is not less than approximately 0.01%, not less than approximately 0.02%, or not less than approximately 0.05% and not greater than approximately 12%, not greater than approximately 10%, or not greater than approximately 8%. As a result of the total light transmittance of the combination of the upper design layer and the reflective layer being within the range described above, the visibility of the second design in daylight can be effectively reduced, and the visibility of the second design when illuminated by a light source from behind can be maintained.

In some embodiments, the total light transmittance in the visible range of the lower design layer is not less than approximately 1%, not less than approximately 2%, or not less than approximately 3% and not greater than approximately 70%, not greater than approximately 60%, or not greater than approximately 50%. As a result of the total light transmittance of the lower design layer being within the range described above, the clarity of the second design when illuminated by a light source from behind can be increased.

Examples of the upper and lower design layers include a color layer that exhibits a paint color or the like, a pattern layer that expresses a logo, an image, or a pattern such as a wood grain pattern, stone grain pattern, geometric pattern or leather pattern, a relief (embossed pattern) layer in which recesses and protrusions are provided on the surface, and layers including combinations thereof.

A resin layer in which pigments such as inorganic pigments such as titanium oxide, carbon black, chrome yellow, yellow iron oxide, colcothar, or red iron oxide; organic pigments such as phthalocyanine pigments (phthalocyanine blue, phthalocyanine green, or the like), azo lake pigments, indigo pigments, perinone pigments, perylene pigments, quinophthalone pigments, dioxazine pigments, or quinacridone pigments such as quinacridone red are dispersed in a binder resin such as (meth)acrylic resin or polyurethane can be used as a color layer. In some embodiments, the upper design layer includes a transparent color layer, and the total light transmittance of the upper design layer is not less than approximately 5%, not less than approximately 90%, or not less than approximately 95%.

As a pattern layer, a layer having a pattern, logo, design, or the like formed by printing such as gravure direct printing, gravure offset printing, inkjet printing, laser printing or screen printing, coating such as gravure coating, roll coating, die coating, bar coating or knife coating, punching, or etching may be used.

The pattern layer may be supported by the resin layer. A variety of resins such as acrylic resins that include polymethyl methacrylate (PMMA), polyurethane, polyvinyl chloride, polycarbonate, acrylonitrile/butadiene/styrene copolymer (ABS), polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate, and copolymers such as ethylene/acrylic acid copolymer, ethylene/ethyl acrylate copolymer, and ethylene/vinyl acetate copolymer, or mixtures thereof, for example, can be used as the transparent resin layer. From the perspectives of strength, impact resistance, and the like, polyurethane, polyvinyl chloride, polyethylene terephthalate, acrylonitrile/butadiene/styrene copolymer and polycarbonate can be advantageously used as the resin layer. The resin layer may be provided in the form of a film, a sheet, or the like.

The pattern layer may include a plurality of regions of different colors and/or light transmittance. In FIGS. 1, 2A, and 2B, the lower design layer 16 includes a pattern layer 164 supported on the second resin layer 162, and the pattern layer 164 is illustrated as a layer that has a different color and light transmittance depending on the location. For example, as illustrated in FIG. 2B, light from the light source 32 is transmitted in regions where the pattern layer 164 is present (white regions), while a portion of light is transmitted in other regions (regions with diagonal lines), and light is not transmitted in other regions (black regions).

As a relief layer, a thermoplastic resin resin layer having a concavo-convex form on the surface obtained by a conventionally known method such as embossing, scratching, laser processing, dry etching, hot pressing, or the like may be used. The relief layer can be formed by coating a heat-curable or radiation-curable resin such as curable (meth)acrylic resin on a release film having a concavo-convex form, curing it by heat or radiation, and removing the release film. The thermoplastic resin, heat-curable resin and radiation-curable resin used in the relief layer are not particularly limited, but fluorine resins, polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), (meth)acrylic resins, a polyolefins such as polyethylene and polypropylene, thermoplastic elastomers, polycarbonates, polyamides,

acrylonitrile-butadiene-styrene copolymers (ABS), acrylonitrile-styrene copolymers, polystyrenes, polyvinyl chlorides, polyurethanes, and the like may be used.

In one embodiment, the upper design layer includes a color layer, and the lower design layer includes a pattern layer. In this embodiment, the film exhibits an appearance with a uniform color (first design) in an environment in which light is incident from the upper surface of the light-transmissive decorative film in daylight or the like, and a combination of the color of the upper design layer and the pattern of the lower design layer (second design) is visible when light is made incident from the lower surface of the light-transmissive decorative film using a light source or the like in a state in which the vicinity is dark. In another embodiment, both the upper design layer and the lower design layer include pattern layers. In this embodiment, the pattern of the upper design layer (first design) is visible in an environment in which light is incident from the upper surface of the light-transmissive decorative film in daylight or the like, and a combination of the pattern of the upper design layer and the pattern of the lower design layer (second design) is visible when light is made incident from the lower surface of the light-transmissive decorative film using a light source or the like in a state in which the vicinity is dark. The upper design layer may include a surface layer disposed on the uppermost surface of the light-transmissive decorative film. The surface layer may have a substantially smooth surface, or may have a concavo-convex surface such as an embossed pattern on the surface. As a surface layer, a variety of resins such as (meth)acrylic resins including polymethyl methacrylate (PMMA), polyurethane, fluorine resins such as ethylene/tetrafluoroethylene copolymers (ETFE), polyvinylidene fluoride (PVDF), and methyl methacrylate/vinylidene fluoride copolymers (PMMA/PVDF), silicone copolymers, polyolefins such as polyvinyl chlorides, polycarbonates, acrylonitrile-butadiene-styrene copolymers (ABS), polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), copolymers such as ethylene-acrylic acid copolymers, ethylene -ethyl acrylate copolymers, and ethylene -vinyl acetate copolymers, or mixtures thereof, for example, can be used. From the perspectives of transparency, strength, impact resistance, and the like, (meth)acrylic resins, polyurethanes, polyvinyl chlorides, polyethylene terephthalate, acrylonitrile/butadiene/styrene copolymers and polycarbonates can be advantageously used as the surface layer. The surface layer may function as a protective layer for protecting other layers forming the light-transmissive decorative film from puncture, impact, or the like from the outside. The surface layer may be a multilayer laminate such as a multilayer extruded laminate, for example.

The surface layer may include, as necessary, ultraviolet absorbers such as benzotriazole, Tinuvin (trademark) 400 (manufactured by BASF), and the like, and hindered amine light stabilizers (HALS) such as Tinuvin (trade name) 292 (manufactured by BASF), and the like. Through the use of ultraviolet absorbers, hindered amine light stabilizers, and the like, discoloration, fading, deterioration and the like of coloring material (in particular organic pigments that are relatively sensitive to light such as ultraviolet light, and the like) that may be included in the upper design layer or the lower design layer can be effectively prevented. The surface layer may include hard coating material, a luster giving agent, and the like, and may also have an additional hard coating layer. The entire surface layer is typically transparent, but in order to provide an intended appearance, all or a portion of the outermost layer may be translucent, and a portion of the protective layer may be opaque. In some embodiments, the total light transmittance in the visible range of the surface layer is not less than approximately 85%, not less than approximately 90%, or not less than approximately 95%.

A resin layer that can be used in the upper design layer or the lower design layer may be adhesive. In some embodiments, the reflective layer or the like can be directly laminated on such as resin layer without interposing a bonding layer. When the second resin layer included in the lower design layer is adhesive, the light-transmissive decorative film can be adhered to the substrate without separately providing an adhesive layer. An adhesive resin layer may be formed by adding a tackifier to the resin material described above, for example, or may be formed from the same material as the adhesive layer described below. The first resin layer included in the upper design layer may have a translucent metallic layer with a total transmittance in the visible range of not less than approximately 10% and not greater than approximately 70%, for example, inside the first resin layer. The presence of such a translucent metallic layer makes it possible to provide a design with a flip-flop property in which the appearance changes depending on the angle of viewing. The translucent metallic layer may be a metal thin film containing a metal selected from aluminum, nickel, gold, platinum, chromium, iron, copper, tin, indium, silver, titanium, lead, zinc, germanium, and the like formed by vacuum deposition, sputtering, ion plating, plating, or the like, or may be a brightening (metallic) resin layer in which brightening (metallic) pigments such as aluminum brightening material, such as aluminum flakes, vapor-deposited aluminum flakes, metal oxide-coated aluminum flakes, or colored aluminum flakes, or pearl brightening material, such as flake or synthetic mica covered with a metal oxide such as titanium oxide, or iron oxide, are dispersed in a binder resin such as acrylic resin, or polyurethane resin.

The upper design layer and the lower design layer may have a variety of thicknesses, but the thickness is typically not less than approximately 0.1 μιη, not less than approximately 1 μιη, or not less than approximately 3 μιη and not greater than approximately 300 μιη, not greater than approximately 200 μιη, or not greater than approximately 100 μιη. In an embodiment in which the upper design layer includes a surface layer, the thickness of the surface layer may typically be not less than approximately 1 μιη, not less than approximately 5 μιη, or not less than approximately 10 μιη and not greater than approximately 200 μιη, not greater than approximately 100 μιη, or not greater than approximately 80 μιη. When the decorative film is applied to a substrate with a complex shape, a thinner surface layer is advantageous from the perspective of conformity to the shape of the substrate, and a thickness of not greater than approximately 100 μιη or not greater than approximately 80 μιη, for example, is preferable. On the other hand, when the objective is to protect the films forming the light-transmissive decorative film, a thicker surface layer is advantageous, and a thickness of not less than approximately 5 μιη or not less than approximately 10 μιη, for example, is preferable.

The reflective layer may be a metal thin film containing a metal selected from aluminum, nickel, gold, platinum, chromium, iron, copper, tin, indium, silver, titanium, lead, zinc, germanium, or the like, or alloys or compounds of the same, formed by vacuum deposition, sputtering, ion plating, plating or the like. By using a metal thin film, high reflection performance can be achieved while increasing the conformity to the shape of the substrate by reducing the total thickness of the light-transmissive decorative film.

In one embodiment, the reflective layer is a vapor-deposited layer containing tin, indium, or a combination thereof. In this embodiment, the stability of the metal forming the reflective layer is high, and deterioration such as corrosion or discoloration is unlikely to occur even when oxidized, so the reflection performance of the reflective layer can be maintained over a long period of time.

The reflective layer may be a resin layer in which brightening pigments such as aluminum brightening material, such as aluminum flakes, vapor-deposited aluminum flakes, metal oxide-coated aluminum flakes, or colored aluminum flakes, or pearl brightening material, such as flake or synthetic mica covered with a metal oxide such as titanium oxide, or iron oxide, are dispersed in a binder resin such as a (meth)acrylic resin or polyurethane. The reflective layer may be a metal foil of aluminum, nickel, gold, silver, copper, or the like.

When the reflective layer is a metal thin film or a metal foil, it is advantageous for the reflective layer to be supported on a resin layer. By supporting the reflective layer on a resin layer, damage to the reflective layer can be prevented or reduced when the light-transmissive decorative film deforms due to the three-dimensional overlay method. The resin layer may be the first resin layer of the upper design layer, the second resin layer of the lower design layer, or a third resin layer separate from these design layers.

The surface of the resin layer supporting the reflective layer may be a flat surface or may be an uneven surface. When the resin layer surface is uneven, the reflective layer itself that is formed thereon becomes uneven, which makes it possible to achieve complex light reflection and exhibit a visual effect abounding in change.

In one embodiment, as illustrated in FIG. 3, the light-transmissive decorative film 10 further includes a third resin layer 15, and the reflective layer 14 is supported on the surface of the third resin layer 15. As illustrated in FIG. 3, the third resin layer 15 may have an uneven surface, which causes the reflective layer 14 to also have an uneven surface.

In one embodiment, the resin layer supporting the reflective layer contains at least one thermoplastic resin selected from the group consisting of vinyl chloride/vinyl acetate copolymers, polyurethanes, polyesters, (meth)acrylic resins, and phenoxy resins. In the present disclosure,

"phenoxy resin" means a thermoplastic polyhydroxy polyether synthesized using a bisphenol and epichlorohydrin, and encompasses those having an epoxy group derived from a tiny amount of epichlorohydrin in the molecule (for example, at the terminal). For example, the epoxy equivalent amount of phenoxy resin is higher than that of epoxy resin, for example, not less than 5,000, not less than 7,000 or not less than 10,000.

It is advantageous for the resin layer supporting the reflective layer to contain a phenoxy resin. A resin layer containing a phenoxy resin has particularly excellent adhesion to a reflective layer containing a metal such as tin, indium or the like. In one embodiment, the resin layer supporting the reflective layer contains a phenoxy resin and a polyurethane - in particular, a polyester-based polyurethane with excellent miscibility with the phenoxy resin.

The OD (optical density) value of the reflective layer is not less than approximately 0.7 and not greater than approximately 1.7. In some embodiments, the OD value of the reflective layer is not less than approximately 0.8 or not less than approximately 0.9 and not greater than approximately 1.5 or not greater than approximately 1.3. By setting the OD value of the reflective layer to within the range described above, it is possible to reflect light incident from the upper surface of the light-transmissive decorative film in daylight and to transmit at least a portion of light incident from the lower surface of the light-transmissive decorative film. As a result, it is possible to provide a highly designable appearance of two types that change when the light-transmissive decorative film is placed in daylight without being illuminated by a light source from behind and when placed in a dark environment and illuminated with a light source from behind.

As long as the thickness of the reflective layer is set so that the reflective layer has the OD value described above, the thickness may differ depending on the material and a formation method of the reflective layer, even for the same OD value. For example, when a vapor-deposited layer containing tin, indium, or a combination thereof is used as a reflective layer, these films ordinarily form a sea-island structure and may have a continuous layer structure.

The light-transmissive decorative film may further include an adhesive layer disposed on the lower design layer side when viewed from the reflective layer of the light-transmissive decorative film. Generally used adhesives such as solvent-type, emulsion-type, pressure-sensitive type, heat-sensitive type, and heat-curable or ultraviolet-curable type adhesives, including (meth)acrylics, polyolefins, polyurethanes, polyesters, rubbers, and the like can be used as the adhesive layer. The thickness of the adhesive layer is typically not less than approximately 5 μπι, not less than approximately 10 μπι, or not less than approximately 20 μπι and not greater than approximately 200 μπι, not greater than approximately 100 μπι, or not greater than approximately 80 μιη.

As the release layer for protecting the adhesive layer or the resin layer that is adhesive, any release liner can be used. Examples of typical release liners include those prepared from paper (for example, kraft paper), and polymer materials (for example, polyolefins such as polyethylene and polypropylene, and ethylene vinyl acetate, polyurethane and polyesters such as polyethylene terephthalate and the like). The release liner may be coated as necessary with a silicone-containing material or fluorocarbon-containing material. The thickness of the release liner is typically not less than approximately 5 μπι, not less than approximately 15 μπι, or not less than approximately 25 μπι and not greater than approximately 300 μπι, not greater than approximately 200 μπι, or not greater than approximately 150 μπι.

Each layer forming the light-transmissive decorative film may be bonded using a bonding layer. Generally used adhesives such as solvent-type, emulsion-type, pressure-sensitive type, heat-sensitive type, and heat-curable or ultraviolet-curable type adhesives, including acrylics, polyolefins, polyurethanes, polyesters, rubbers, and the like can be used as the bonding layer. The thickness of the bonding layer is typically not less than approximately 0.05 μπι, not less than approximately 0.5 μιη, or not less than approximately 5 μιη, and not more than approximately 100 μιη, not more than approximately 50 μιη, or not more than approximately 20 μιη.

Within a range that does not diminish the visual effect of the light-transmissive decorative film, the adhesive layer and/or the bonding layer may contain coloring materials such as the same inorganic pigments and organic pigments as those described for the upper and lower design layers.

In some embodiments, the storage modulus of one or a plurality of the resin layer and surface layer of the upper design layer, the resin layer of the lower design layer, and the resin layer forming the reflective layer or supporting the reflective layer may be not less than approximately 1 x 10 6 Pa, not less than approximately 1.5 χ 10 6 Pa, or not less than approximately 2 χ 10 6 Pa and not greater than approximately 1.5 χ 10 8 Pa or not greater than approximately 1.3 χ 10 8 Pa in the temperature range of from 110°C to 150°C when measured in the tension mode at a frequency of 10 Hz. As a result of the storage modulus of the resin layer or the surface layer being within the range described above, the light-transmissive decorative film can be made to conform well to the three-dimensional curved face of the substrate. This makes it possible to prevent damage to the reflective layer and to maintain the quality of the first and second designs when stress, heat, or the like is applied to the light-transmissive decorative film or when the light-transmissive decorative film deforms.

It is advantageous for a resin layer, which has a storage modulus of not less than approximately 1 χ 10 6 Pa, not less than approximately 1.5 χ 10 6 Pa, or not less than approximately 2 x 10 6 Pa and not greater than approximately 1.5 χ 10 8 Pa or not greater than approximately 1.3 χ 10 8 Pa in the temperature range of from 1 10°C to 150°C when measured in the tension mode at a frequency of 10 Hz, to be disposed on both sides of the reflective layer. As a result of using a sandwich structure in which the reflective layer is supported from both sides by resin layers having a storage modulus within the range described above, damage to the reflective layer can be more effectively prevented when the light-transmissive decorative film is greatly deformed by a three-dimensional curved face overlay method, for example, or when the light-transmissive decorative film is stretched at an area stretching ratio of 100% or greater or 200% or greater.

In some other embodiments, the storage modulus of one or a plurality of the resin layer and surface layer of the upper design layer, the resin layer of the lower design layer, and the resin layer forming the reflective layer or supporting the reflective layer may be not less than approximately 1 χ 10 5 Pa, not less than approximately 1.5 χ 10 5 Pa, or not less than approximately 2 x 10 5 Pa and not greater than approximately 2 χ 10 8 Pa, not greater than approximately 1.5 χ 10 8 Pa, or not greater than approximately 1 χ 10 8 Pa in the temperature range of from 1 15°C to 140°C when measured in the tension mode at a frequency of 10 Hz. As a result of the storage modulus of the resin layer or the surface layer being within the range described above, the light-transmissive decorative film can be made to conform well to the three-dimensional curved face of the substrate. This makes it possible to prevent damage to the reflective layer and to maintain the quality of the first and second designs when stress, heat, or the like is applied to the light-transmissive decorative film or when the light-transmissive decorative film deforms.

It is advantageous for a resin layer, which has a storage modulus of not less than approximately 1 χ 10 5 Pa, not less than approximately 1.5 χ 10 5 Pa, or not less than approximately 2 x 10 5 Pa and not greater than approximately 2 χ 10 8 Pa, not greater than approximately 1.5 χ 10 8 Pa, or not greater than approximately 1 χ 10 8 Pa in the temperature range of from 1 15°C to 140°C when measured in the tension mode at a frequency of 10 Hz, to be disposed on both sides of the reflective layer. As a result of using a sandwich structure in which the reflective layer is supported from both sides by resin layers having a storage modulus within the range described above, damage to the reflective layer can be more effectively prevented when the light-transmissive decorative film is greatly deformed by a three-dimensional curved face overlay method, for example, or when the light-transmissive decorative film is stretched at an area stretching ratio of 100% or greater or 200% or greater.

The light-transmissive decorative film can be produced by appropriately combining conventionally known methods such as coating, heat lamination, transferring, printing, vapor deposition, and extrusion. The following production method will be described hereinafter as an example, but the production method for a light-transmissive decorative film is not limited to this example.

A pattern layer constituting a lower design layer is formed by printing on a release liner such as a PET film, and a resin layer A is formed by coating on the pattern layer. An adhesive layer formed by coating, extrusion, or the like on a separate release liner B is then laminated by heat lamination on the resin layer A to form a laminate 1 including a lower design layer.

A resin layer B is formed by coating on another release liner C such as a PET film, and a metal such as tin or indium is vapor-deposited on the resin layer B to form a reflective layer supported on the resin layer B. Colored transparent resin layer C constituting an upper design layer is laminated by heat lamination on the reflective layer. A resin layer serving as a surface layer of the upper design layer is then laminated by heat lamination on the transparent resin layer C, and the resin film surface is subjected to emboss finishing to form a laminate 2.

The release liner A of the laminate 1 and the release liner C of the laminate 2 are then removed, and a light-transmissive decorative film is formed by heat-laminating the laminates 1 and 2,such that the pattern layer included in the lower design layer of the laminate 1 and the resin layer B of the laminate 2 face one another. In the method of manufacturing the light-transmissive decorative film, the coating may include a drying and/or a curing process as necessary, and the co-extrusion method may be replaced with a single layer extrusion method, a multilayer extrusion method, or the like.

In some embodiments, the thickness of the light-transmissive decorative film is not less than approximately 25 μπι, not less than approximately 50 μπι, or not less than approximately 100 μηι and not greater than approximately 2 mm, not greater than approximately 1 mm, or not greater than approximately 500 μιη. By setting the thickness of the light-transmissive decorative film to be within the range described above, the decorative film can be made to sufficiently conform to a substrate with a complex shape, and thus a structure with excellent appearance can be provided.

In some embodiments, the storage modulus of the light-transmissive decorative film is not less than approximately 1 χ 10 6 Pa, not less than approximately 1.5 χ 10 6 Pa, or not less than approximately 2 χ 10 6 Pa and not greater than approximately 1.5 χ 10 8 Pa or not greater than approximately 1.3 χ 10 8 Pa in the temperature range of from 1 10°C to 150°C when measured in the tension mode at a frequency of 10 Hz. In the present disclosure, the "storage modulus of the light-transmissive decorative film" refers to a single value measured for the entire multilayer structure, which is a combination of the storage moduli of each individual layer constituting the light-transmissive decorative film. As a result of the storage modulus of the light-transmissive decorative film being within the range described above, the light-transmissive decorative film can be made to conform well to the three-dimensional curved face of the substrate. This makes it possible to prevent damage to the reflective layer and to maintain the quality of the first and second designs when stress, heat, or the like is applied to the light-transmissive decorative film or when the light-transmissive decorative film deforms.

In some other embodiments, the storage modulus of the light-transmissive decorative film is not less than approximately 1 χ 10 5 Pa, not less than approximately 1.5 χ 10 5 Pa, or not less than approximately 2 χ 10 5 Pa and not greater than approximately 2 χ 10 8 Pa, not greater than approximately 1.5 χ 10 8 Pa, or not greater than approximately 1 χ 10 8 Pa in the temperature range of from 1 15°C to 140°C when measured in the tension mode at a frequency of 10 Hz. As a result of the storage modulus of the light-transmissive decorative film being within the range described above, the light-transmissive decorative film can be made to conform well to the

three-dimensional curved face of the substrate. This makes it possible to prevent damage to the reflective layer and to maintain the quality of the first and second designs when stress, heat, or the like is applied to the light-transmissive decorative film or when the light-transmissive decorative film deforms.

In some embodiments, the total light transmittance in the visible range of the light-transmissive decorative film is not greater than approximately 3%, not greater than approximately 2.5%, or not greater than approximately 2% and not less than approximately 0.01 %, not less than approximately 0.025%, or not less than approximately 0.04%. As a result of the total light transmittance of the light-transmissive decorative film being within the range described above, the visibility of the design provided by the lower design layer in daylight can be effectively reduced, and the visibility of the second design provided by a combination of the upper and lower design layers when illuminated by a light source from behind can be maintained. In some other embodiments, the total light transmittance in the visible range of the light-transmissive decorative film is not greater than approximately 12%, not greater than approximately 10%, or not greater than approximately 8% and not less than approximately 0.01%, not less than approximately 0.05%, or not less than approximately 0.1%. As a result of the total light transmittance of the light-transmissive decorative film being within the range described above, the visibility of the design provided by the lower design layer in daylight can be effectively reduced, and the visibility of the second design provided by a combination of the upper and lower design layers when illuminated by a light source with low power output, in particular, from behind can be maintained.

The scratch resistance of the light-transmissive decorative film can be evaluated in terms of pencil hardness in accordance with JIS K5600-5-4. The pencil hardness of the

light-transmissive decorative film of one embodiment is 6B or greater when measured by fixing the light-transmissive decorative film on a glass plate and then scratching the surface at a rate of 600 mm/min. The pencil hardness may be not below 5B, not below 4B, or not below 3B.

According to an embodiment of the present disclosure, a molded article in which a substrate is covered by the light-transmissive decorative film is provided. For example, by applying the light-transmissive decorative film to the surface of a substrate using TOM, a molded article in which the substrate is covered with the light-transmissive decorative film can be formed. Similarly, even when injection molding, extrusion, or the like, which does not require a high degree of conformity to the shape of the film shape in comparison to TOM, is used, a molded article in which the light-transmissive decorative film is attached to the substrate can be formed.

The substrate may contain various materials such as polyethylenes, polypropylenes, (meth)acrylic resins, polycarbonates, acrylonitrile -butadiene -styrene copolymers, blends thereof, or combinations thereof, for example. The substrate may be an inorganic material having optical transparency such as glass. The substrate may have various shapes such as a flat shape or a three-dimensional shape. The substrate is translucent or transparent. It is advantageous for the substrate to be transparent - in particular, for the total light transmittance of the substrate in a wavelength range of from 400 to 700 nm to be not less than approximately 90% or not less than approximately 95% - as it allows the second design provided by the lower design layer to be clearly visible. In some embodiments, the substrate contains a polycarbonate with excellent strength and transparency.

As in the case of the upper and lower design layers, the substrate may be a color layer that exhibits a paint color or the like, a pattern layer that expresses a logo, an image, or a pattern such as a wood grain pattern, stone grain pattern, geometric pattern or leather pattern, a relief (embossed pattern) layer in which an uneven shape is provided on the surface, or a combination thereof, or the substrate may contain such a layer. Examples of color layers, pattern layers, and relief layers are the same as those explained for the upper and lower design layers. The color layer may be a colored film attached to the substrate. In the molded article, a first design produced by the upper design layer is visible in daylight, and a second design produced by a combination of the upper design layer, the substrate, and the lower design layer is visible in the presence of light passing through the substrate, the lower design layer, the reflective layer, and the upper design layer in this order.

In a molded article further including an adhesive layer disposed between the

light-transmissive decorative film and the substrate, a first design produced by the upper design layer is visible in daylight, and a second design produced by a combination of the upper design layer, the substrate, the adhesive layer, and the lower design layer is visible in the presence of light passing through the substrate, the adhesive layer, the lower design layer, the reflective layer, and the upper design layer in this order. The adhesive layer may be a layer forming the

light-transmissive decorative film as described above, or the adhesive layer may be formed on the substrate surface. An adhesive layer functioning as a color layer, for example, may contain colorants such as pigments such as inorganic pigments such as titanium oxide, carbon black, chrome yellow, yellow iron oxide, colcothar, or red iron oxide; organic pigments such as phthalocyanine pigments (phthalocyanine blue, phthalocyanine green, or the like), azo lake pigments, indigo pigments, perinone pigments, perylene pigments, quinophthalone pigments, dioxazine pigments, or quinacridone pigments such as quinacridone red.

In one embodiment, the substrate has unevenness on the surface on the opposite side as the light-transmissive decorative film. Schematic cross-sectional views of a molded article and a lighting display device to which the light-transmissive decorative film of this embodiment is attached are illustrated in FIGS. 4 A and 4B. FIG. 4A illustrates how the lighting display device looks when observed in a state in which the light source is off, and FIG. 4B illustrates how the lighting display device looks in a state in which the light source is on. In FIG. 4A, as in FIG. 2A, the light source 32 is off, and light incident from the upper side of the light-transmissive decorative film 10 in daylight is reflected by the reflective layer 14 so that a design (first design) produced by the upper design layer 12 is visible to an observer. In FIG. 4B, the advancing direction changes when light from the light source 32 is incident on the uneven surface of the substrate 22, and the light then passes through the substrate 22, the adhesive layer 18, the lower design layer 16, the reflective layer 14, and the upper design layer 12. As a result, a design (second design) produced by a combination of the upper design layer 12 and the lower design layer 16, a combination of the upper design layer 12, the substrate 22, and the lower design layer 16, and a combination of the upper design layer 12, the substrate 22, the adhesive layer 18, and the lower design layer 16 is visible to an observer in the presence of light passing through the substrate 22, the adhesive layer 18, the lower design layer 16, the reflective layer 14, and the upper design layer 12 in this order.

Since the advancing direction of light incident on the substrate 22 changes, a visual effect in which the brightness, design, or the like changes depending on the angle at which the molded article is observed, for example, can be obtained.

In some embodiments, the total light transmittance in the visible range of the molded article is not greater than approximately 3%, not greater than approximately 2.5%, or not greater than approximately 2% and not less than approximately 0.01%, not less than approximately

0.025%, or not less than approximately 0.04%. As a result of the total light transmittance of the molded article being within the range described above, the visibility of the design (second design) provided by the lower design layer and optionally the substrate and/or adhesive layer in daylight can be effectively reduced, and the visibility of the second design when illuminated by a light source from behind can be maintained.

In some other embodiments, the total light transmittance in the visible range of the molded article is not greater than approximately 12%, not greater than approximately 10%, or not greater than approximately 8% and not less than approximately 0.01%, not less than approximately 0.05%, or not less than approximately 0.1%. As a result of the total light transmittance of the molded article being within the range described above, the visibility of the design (second design) provided by the lower design layer and optionally the substrate and/or adhesive layer in daylight can be effectively reduced, and the visibility of the second design when illuminated by a light source with low power input, in particular, from behind can be maintained.

The maximum area stretching ratio of the light-transmissive decorative film after molding is generally not lower than approximately 50%, not lower than approximately 100%, or not lower than approximately 200% and not higher than approximately 1000%, not higher than

approximately 500%, or not higher than approximately 300%. The area stretching ratio is defined as area stretching ratio (%) = (B-A)/A (where A is the area of a certain portion of the light-transmissive decorative film before molding, and B is the area of the portion corresponding to A of the light-transmissive decorative film after molding). For example, if the area of a certain portion of the light-transmissive decorative film is 100 cm 2 before molding and the area of that portion of the article after molding is 250 cm 2 , the area stretching ratio is 150%. The maximum area stretching ratio refers to the value at the location of highest area stretching ratio in the light-transmissive decorative film on the entire article surface. For example, when a flat film is affixed to a three-dimensional substrate by TOM, the portion of the film that first affixes to the substrate is stretched very little and has an area stretching ratio of nearly 0%. The ends that are affixed last are stretched significantly and achieve an area stretching ratio of 200% or higher. Thus, the area stretching ratio varies widely depending on location. Whether the molding process is acceptable or not is determined by the presence or absence of defects such as nonconformity to the substrate, tearing of the film, and the like in the portions of the film that are stretched the most. Accordingly, the area stretching ratio in the portion that was stretched the most, that is, the maximum area stretching ratio rather than the average area stretching ratio of the overall molded product becomes the substantial index for the acceptability of the molded product. The maximum area stretching ratio is determined by, for example, printing 1-mm squares on the entire surface of the light-transmissive decorative film before molding and then measuring the change in the areas thereof after molding, or by measuring the thickness of the light-transmissive decorative film before and after molding.

One embodiment of the present disclosure provides a lighting display device including a molded article in which a substrate is covered by a light-transmissive decorative film, and a light source disposed on the lower design layer side from the perspective of the reflective layer of the light-transmissive decorative film. Various light sources such as an LED, a fluorescent lamp, an incandescent lamp, or a halogen lamp may be used as a light source . It is advantageous for an LED, which has a high illuminance and small amount of heat radiation, to be used as the light source used in the lighting display device. A diffusing plate or a diffusing film may be disposed between the molded article and the light source with the objective of reducing the visibility of the shape of the light source by diffusing the light from the light source.

The illuminance of the light source used in the lighting display device may be, for example, not less than approximately 0.5 lm/m 2 , not less than approximately 0.6 lm/m 2 , or not less than approximately 0.7 lm/m 2 and not greater than approximately 300 lm/m 2 , not greater than approximately 200 lm/m 2 , or not greater than approximately 100 lm/m 2 on a measurement surface positioned 15 cm vertically away from the light-emitting surface of the light source. The illuminance in the present disclosure can be measured using an illuminance meter in accordance with JIS C 7801 :2014 "Methods of Measuring Light of Light Sources for General Lighting".

The illuminance of the lighting display device may be, for example, not less than approximately 0.5 lm/m 2 , not less than approximately 0.6 lm/m 2 , or not less than approximately 0.7 lm/m 2 and not greater than approximately 45 lm/m 2 , not greater than approximately 35 lm/m 2 , or not greater than approximately 30 lm/m 2 on a measurement surface positioned 15 cm vertically away from the center of the surface of the molded article.

The light-transmissive decorative film of the present disclosure may be suitably used in three-dimensional heat-stretching molding methods such as insert molding or TOM for the purpose of decoration of automobile parts, household appliances, railroad cars, and building materials, and it may be used particularly suitably in TOM. The light-transmissive decorative film of the present disclosure may also be used in other molding methods such as, for example, various molding techniques such as injection molding or extrusion, or may be used by applying the light-transmissive decorative film to a flat substrate such as a plastic sheet or window glass. EXAMPLES

In the following examples, specific embodiments of the present disclosure are described as examples, but the present disclosure is not limited to these embodiments. All "parts" and "percent" are based on mass unless specified otherwise.

Examples 1 to 3 and Comparative Examples 1 and 2

A light-transmissive decorative film was produced in accordance with the following procedure. A water-based polyurethane solution (Resamine (trade name) D6260 (called a "water-based urethane solution" hereinafter), Dainichiseika Color & Chemicals Mfg. Co., Ltd. (Chuo-ku, Tokyo, Japan)) was applied to a printed layer with a wood pattern formed on a polyethylene terephthalate (PET) film with a thickness of 50 μπι subj ected to mold release treatment, and this was heated for 5 minutes at 120°C to form a polyurethane layer with athickness of 20 μπι. A white acrylic adhesive layer with a thickness of 40 μπι was then formed on a liner prepared by forming a melamine mold release layer on a PET film (ACW200, 3M (St. Paul, Minnesota, USA), and after drying, this was heat-laminated at 50°C on the polyurethane layer to form a laminate 1.

A tin vapor-deposited layer having the respective OD value shown in Table 1 was formed on a polyurethane layer formed with a thickness of 20 μπι using a water-based urethane solution on another PET film with a thickness of 50 μπι subjected to mold release treatment, and a thin, pitch black printed layer formed on yet another PET film with a thickness of 50 μπι subjected to mold release treatment was heat-laminated at 50°C on the vapor-deposited layer. The OD value was determined using a Gretag Macbeth D200-II concentration meter.

After the PET film supporting the pitch black printed layer was removed, an acrylic film (Technolloy (Trademark) S014S, Escarbo Sheet (Mitsuke-shi, Niigata, Japan) with a thickness of 75 μπι was heat-laminated at 50°C. The acrylic film surface was then subjected to emboss finishing using a heating cylinder having a hairline shape to form a laminate 2.

After the other PET film of the laminate 2 was removed, the PET film supporting the printed layer with a wood pattern of the laminate 1 was removed, and the polyurethane layer of the laminate was positioned so as to face the printed layer with a wood pattern of the laminate 1 and heat-laminated at 120°C to produce a light-transmissive decorative film.

The liner (ACW200) was removed from the light-transmissive decorative film, and this was pressure-bonded at 145°C with a vacuum/pressure forming method onto a polycarbonate substrate having a semi-cylindrical three-dimensionally curved face to produce a molded product to which the light-transmissive decorative film was attached.

The OD value of the tin vapor-deposited layer, the light transmittance (value calculated from OD value), the total light transmittance of the light-transmissive decorative film prior to molding, and the vacuum moldability of the light-transmissive decorative films of Examples 1 to 3 and Comparative Examples 1 and 2 are shown in Table 1. In addition, the appearance when observed in daylight without being illuminated with light from the polycarbonate substrate side using an LED with a power output of 10 W (first design) and the appearance when illuminated with light in a dark room (second design) are also shown in Table 1. An LED tape light (product name: Minger LED tape light for car interior decoration, LED type 5050, output power: 10 W (2.5 W χ 4 tapes), source: Shenzhen Minger E-commerce Co., Ltd. (Shenzhen City, Guandong Province, People's Republic of China)) was used as a light source. The total light transmittance was measured using an NDH 2000 haze meter (Nippon Denshoku Industries Co., Ltd. (Bunkyo-ku, Tokyo, Japan)). The first design was considered good if the wood pattern design of the lower design layer was invisible and was considered poor if the wood pattern design was visible. The second design was considered good if the wood pattern of the lower design layer was clearly visible and was considered poor if the wood pattern appeared blurry. The first and second designs of the light-transmissive decorative film of Example 2 are respectively illustrated in photographs in FIGS. 5A and 5B.

Table 1

The storage modulus of the polyurethane layer formed using the water-based urethane solution contained in the light-transmissive decorative film was within the range of from 6.2 χ 10 6 Pa to 1.1 x 10 8 Pa in the temperature range of from HO to 150°C when measured in the tension mode at a frequency of 10 Hz using an ARES dynamic viscoelasticity measuring device

(manufactured by TA Instruments Japan Inc., Shinagawa-ku, Tokyo, Japan).

Example 4

A light-transmissive decorative film was produced in accordance with the following procedure. Two indium vapor-deposited layers were formed in a superimposed manner on a polyurethane layer formed with a thickness of 20 μιη using a water-based urethane solution on another PET film with a thickness of 50 μιη subjected to mold release treatment. The OD value of the indium vapor-deposited layer determined using a Gretag Macbeth D200-II concentration meter was 0.7. The PET film supporting the polyurethane layer was removed, and a printed layer with a wood pattern (thickness: 3-4 μιη) formed on another PET film with a thickness of 50 μιη subjected to mold release treatment was heat-laminated at 120°C on the polyurethane layer to form a laminate 1. A thin, pitch black printed layer (thickness: 3 μηι) formed on yet another PET film with a thickness of 50 μπι subjected to mold release treatment was heat-laminated at 120°C on the indium vapor-deposited layer of the laminate 1 to form a laminate 2.

A multilayer extruded film with a thickness of 105 μπι including a fluorine resin layer and an acrylic resin layer was subjected to emboss finishing on the fluorine resin layer side using a heating cylinder having a hairline shape to form a surface layer.

After the PET film supporting the pitch black printed layer was removed from the laminate 2, a laminate 3 was formed by heat-laminating the surface layer at 120°C on the pitch black printed layer so that the non-embossed surface was in contact with the pitch black printed layer.

A white acrylic adhesive layer with a thickness of 40 μπι was then formed on a liner prepared by forming a melamine mold release layer on a PET film. After the PET film supporting the printed layer with a wood pattern was removed from the laminate 3, a white acrylic adhesive layer was heat-laminated at 50°C on the printed layer with a wood pattern to produce a light-transmissive decorative film.

The liner (ACW200) was removed from the light-transmissive decorative film, and this was pressure-bonded at 145°C with a vacuum/pressure forming method onto a transparent polycarbonate substrate having a semi-cylindrical three-dimensionally curved face to produce a molded product to which the light-transmissive decorative film was attached.

Example 5

A light-transmissive decorative film and a molded article were produced in the same manner as in Example 4 with the exception that a tin vapor-deposited layer having an OD value of 1.2 was used instead of an indium vapor-deposited layer.

Example 6

A light-transmissive decorative film and a molded article were produced in the same manner as in Example 4 with the exception that multilayer vapor-deposited film including an indium vapor-deposited layer and a tin vapor-deposited layer having an OD value of 1.7 was used instead of an indium vapor-deposited layer.

Example 7

A light-transmissive decorative film was produced in accordance with the following procedure. A "cast" pattern was formed as a printed layer by inkjet printing on a polyvinyl chloride film with a thickness of 80 μπι having an acrylic transparent adhesive layer with a thickness of 30 μπι covered by a PET film with a thickness of 50 μπι subjected to mold release treatment to form a laminate 1.

Two indium vapor-deposited layers were formed in a superimposed manner on a polyurethane layer formed with a thickness of 20 μπι using a water-based urethane solution on another PET film with a thickness of 50 μπι subjected to mold release treatment. The OD value of the indium vapor-deposited layer determined using a Gretag Macbeth D200-II concentration meter was 0.7. A thin, pitch black printed layer (thickness: 3 μιη) formed on another PET film with a thickness of 50 μπι subjected to mold release treatment was laminated on the indium vapor-deposited layer. The PET film supporting the polyurethane layer was removed, and an acrylic transparent adhesive layer with a thickness of 30 μπι supported on the PET film with a thickness of 50 μπι subjected to mold release treatment was laminated on the polyurethane layer to form a laminate 2.

A multilayer extruded film with a thickness of 105 μπι including a fluorine resin layer and an acrylic resin layer was subjected to emboss finishing on the fluorine resin layer side using a heating cylinder having a hairline shape to form a surface layer. The acrylic transparent adhesive layer with a thickness of 30 μπι supported on the PET film with a thickness of 50 μπι subjected to mold release treatment was laminated on the non-embossed surface of the surface layer to form a laminate 3.

After the PET film supporting the pitch black printed layer was removed from the laminate 2 and the PET film supporting the acrylic transparent adhesive layer was removed from the laminate 3, a laminate 4 was formed by laminating onto the pitch black printed layer so that the acrylic transparent adhesive layer of the laminate 3 was in contact with the pitch black printed layer.

After the PET film supporting the acrylic transparent adhesive layer of the laminate 4 was removed, a light-transmissive decorative film was produced by laminating the laminate 4 and the laminate 1 so that the acrylic transparent adhesive layer of the laminate 4 was in contact with the printed layer of the laminate 1.

The PET film was removed from the light-transmissive decorative film, and this was pressure-bonded at 120°C with a vacuum/pressure forming method onto a transparent polycarbonate substrate having a semi-cylindrical three-dimensionally curved face to produce a molded product to which the light-transmissive decorative film was attached.

Example 8

A light-transmissive decorative film and a molded article were produced in the same manner as in Example 7 with the exception that the printed layer on the polyvinyl chloride film was changed from a "cast" pattern to a dot and circle pattern.

Comparative Example 3

A light-transmissive decorative film was produced in accordance with the following procedure. A "cast" pattern was formed as a printed layer by inkjet printing on a polyvinyl chloride film with a thickness of 80 μπι having an acrylic transparent adhesive layer with a thickness of 30 μπι covered by a PET film with a thickness of 50 μπι subjected to mold release treatment to form a laminate 1.

Two indium vapor-deposited layers were formed in a superimposed manner on a polyurethane layer formed with a thickness of 20 μπι using a water-based urethane solution on another PET film with a thickness of 50 μιη subjected to mold release treatment. The OD value of the indium vapor-deposited layer determined using a Gretag Macbeth D200-II concentration meter was 0.7. The PET film supporting the polyurethane layer was removed, and an acrylic transparent adhesive layer with a thickness of 30 μιη supported on the PET film with a thickness of 50 μιη subjected to mold release treatment was laminated on the polyurethane layer to form a laminate 2.

A multilayer extruded film with a thickness of 105 μιη including a fluorine resin layer and an acrylic resin layer was subjected to emboss finishing on the fluorine resin layer side using a heating cylinder having a hairline shape to form a surface layer. The acrylic transparent adhesive layer with a thickness of 30 μπι supported on the PET film with a thickness of 50 μπι subjected to mold release treatment was laminated on the non-embossed surface of the surface layer to form a laminate 3.

After the PET film supporting the acrylic transparent adhesive layer was removed from the laminate 3, a laminate 4 was formed by laminating onto the indium vapor-deposited layer so that the acrylic transparent adhesive layer of the laminate 3 was in contact with the indium vapor-deposited layer.

After the PET film supporting the acrylic transparent adhesive layer of the laminate 4 was removed, a light-transmissive decorative film was produced by laminating the laminate 4 and the laminate 1 so that the acrylic transparent adhesive layer of the laminate 4 was in contact with the printed layer of the laminate 1.

The PET film was removed from the light-transmissive decorative film, and this was pressure-bonded at 120°C with a vacuum/pressure forming method onto a transparent polycarbonate substrate having a semi-cylindrical three-dimensionally curved face to produce a molded product to which the light-transmissive decorative film was attached.

Comparative Example 4

A light-transmissive decorative film and a molded article were produced in the same manner as in Comparative Example 3 with the exception that the printed layer on the polyvinyl chloride film was changed from a "cast" pattern to a dot and circle pattern.

The light-transmissive decorative films of Examples 4 to 8 and Comparative Examples 3 and 4 were evaluated with the following procedure.

Appearance in indoor light

The molded article was observed in indoor light, and the appearance was evaluated based on the visibility of the wood pattern, the "cast" pattern, or the dot and circle pattern (second design) under the criteria shown in Table 2. Table 2: A earance assessment criteria in indoor li ht

Appearance when a white LED lamp is on in a dark room

A white LED was disposed below the transparent polycarbonate substrate of the molded article used for appearance evaluation, and this was placed in a dark room (simple tabletop dark room BBX-01, As One Corporation (Osaka-shi, Osaka, Japan). An LED tape light (product name: Minger LED tape light for car interior decoration, LED type 5050, output power: 10 W (2.5 W > 4 tapes), source: Shenzhen Minger E-commerce Co., Ltd. (Shenzhen City, Guandong Province, People's Republic of China)) or an LED surface light-emitting light (LED trace stand, A4 size, power output: 1.8 W, thickness: 5 mm, Unigear (Best Saving Biz ((People's Republic of China))) was used as a light source. The molded article was observed from directly above in a state in which the white LED was turned on in a dark room, and the appearance was evaluated based on the clarity of the wood pattern, the "cast" pattern, or the dot and circle pattern (second design) under the criteria shown in Table 3.

Table 3 : Appearance evaluation criteria when a white LED lamp is on in a dark room

Total Light Transmittance

The total light transmittance of the light-transmissive decorative film was measured. The average value among values measured using an NDH 5000 haze meter (Nippon Denshoku Industries Co., Ltd. (Bunkyo-ku, Tokyo, Japan)) for three areas of the region enclosed by a circle 3 cm in diameter was used as the total light transmittance. For Examples 7 and 8 and Comparative Examples 3 and 4, the total light transmittance of the laminate 2 including a pitch black printed layer and an indium vapor-deposited layer (Examples 7 and 8) and the total light transmittance of the laminate 2 including an indium vapor-deposited layer (Comparative Examples 3 and 4) were also measured.

Illuminance

The illuminance of light that can be seen through the molded article when the white LED lamp is on was measured by placing a black acrylic plate at a position 15 cm vertically away from the center of the surface of the molded article in a dark room to form a measurement surface, and then using the average value among values measured with illuminance meters (T-10M, Konica Minolta Japan, Inc. (Minato-ku, Tokyo, Japan) placed at equal intervals at 12 points (3 x4 points) on the plate as the illuminance (lm/m 2 ).

The evaluation results for Examples 4 to 8 and Comparative Examples 3 and 4 are shown in Table 4.

Table 4

1) N.A. indicates that there are no measurement results.

2) Values in parentheses indicate the results of measuring the illuminance of the light source itself without placing a sample under the light source.