Reversible photochromic laminate

Abstract

The present invention provides a reversible photochromic laminate containing a metal-containing substrate and exhibiting excellent color development. [Solution] A reversible photochromic laminate comprising a substrate containing a metal and having a light reflectance of 30% or more, and a reversible photochromic layer formed on the substrate, which is a dried ink composition containing a reversible photochromic material, wherein the reversible photochromic material contains a photochromic compound.

Description

Technical Field

[0001] The present disclosure relates to a reversible photochromic laminate.

Background Art

[0002] Photochromic compounds have the characteristic of coloring upon irradiation with ultraviolet light or the like and fading when the irradiation is stopped, that is, reversibly changing color depending on the presence or absence of light irradiation, and are used for various applications and purposes. Patent Document 1 discloses printing on a paper substrate using ink mixed with a photochromic compound.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, printing on materials other than paper, for example, on metals, has been carried out.

[0005] One object of the present disclosure is to provide a reversible photochromic laminate having excellent coloring properties and using a substrate containing a metal.

Means for Solving the Problems

[0006] Aspect 1 of the present invention is a substrate containing a metal and having a light reflectance of 30% or more, and a reversible photochromic layer which is a dried product of an ink composition containing a reversible photochromic material formed on the substrate, and the reversible photochromic material contains a photochromic compound, a reversible photochromic laminate.

Effects of the Invention

[0007] According to the present invention, a reversible photochromic laminate containing a metal substrate and exhibiting excellent color development is provided. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 shows the reflectance spectrum of an example of a covering material. [Modes for carrying out the invention]

[0009] Substrates containing metals are light-reflective. It has been found that the higher the light reflectivity of the substrate, the higher the color development of the reversible photochromic layer containing the photochromic compound. Since metals do not transmit light, light irradiated from the side of the reversible photochromic layer is reflected by the surface of the substrate. In other words, both the light irradiated from the side of the reversible photochromic layer and the light reflected by the surface of the substrate are incident on the reversible photochromic layer. This further promotes the color change of the photochromic compound. When the light reflectivity of the substrate is 30% or higher, the reversible photochromic layer exhibits particularly high color development.

[0010] In the case of light-transmitting or light-absorbing substrates such as paper, only light irradiated from the side of the reversible color-changing layer enters the reversible color-changing layer. Therefore, a reversible color-changing layer formed on a metal-containing substrate exhibits higher color development compared to one formed on paper.

[0011] Color development can be expressed in terms of the intensity of the color (also called color density). Excellent color development can be rephrased as having a deep color (high color density). In this specification, color development is evaluated relatively by visual inspection. Color development can also be evaluated by reflectance measured by a spectrophotometer or color density measured by a spectrodensitometer.

[0012] [Reversible photochromic laminate] The reversible photochromic laminate (hereinafter sometimes referred to as "coating") of this disclosure comprises a substrate and a reversible photochromic layer formed on the substrate, which is a dried ink composition containing a reversible photochromic material. The substrate contains a metal and has a light reflectance of 30% or more. The reversible photochromic material contains a photochromic compound.

[0013] Photochromic compounds change color when irradiated with sunlight, ultraviolet light, or light with a peak emission wavelength in the range of 400-495 nm (typically violet light with a wavelength of 405 nm), and decolorize when irradiation is stopped. Therefore, the reversible photochromic layer changes color upon light irradiation due to the action of the photochromic compound. For example, the color of the coating changes between indoors and outdoors, or between daytime and nighttime. The coatings of this disclosure have excellent design and high appeal.

[0014] (base material) The base material contains a metal. The metal content may be, for example, 10% by mass or more, 50% by mass or more, 90% by mass or more, or 100% by mass of the base material.

[0015] The substrate has a light reflectance of 30% or more. This improves the color development of the reversible light-color-changing layer. The light reflectance of the substrate may be 35% or more, 50% or more, or 80% or more.

[0016] Light reflectance is measured using a spectrophotometer. The wavelength of light used for measurement is not particularly limited; any wavelength within the range in which the photochromic compound exhibits color is acceptable. Typically, light reflectance is measured by irradiating the substrate with violet light at a wavelength of 405 nm.

[0017] The type of metal is not particularly limited. Examples of metals include one or more selected from the group consisting of aluminum, aluminum alloys, iron, iron alloys (typically steel), zinc, and zinc alloys. The base material may contain at least one of aluminum and aluminum alloys.

[0018] The surface of the substrate may be in any form as long as it has a light reflectance of 30% or more. The substrate may be subjected to a surface treatment for smoothing the surface. Examples of the surface treatment include chemical conversion treatment, electrolytic polishing, chemical polishing, anodic oxidation, and plating treatment.

[0019] The substrate may have a colored appearance, a non-colored appearance, or a metallic luster. From the viewpoint of color development, the substrate may be non-colored (so-called silver color) with a metallic luster.

[0020] The shape of the substrate may be planar or three-dimensional. The substrate may have a three-dimensional shape.

[0021] The substrate may contain materials other than metals. Examples of materials other than metals include paper, synthetic paper, fibers, fabrics, synthetic leather, natural leather, plastics, foams, glass, ceramics, wood, or stone. These may be used alone or in combination of two or more.

[0022] The substrate may be a printing object. That is, the substrate may be a material suitable for printing, and the reversible photochromic layer may be formed on the substrate by a printing method.

[0023] (Reversible photochromic layer) The reversible photochromic layer is a dried solid of the ink composition. The reversible photochromic layer is formed by drying and solidifying the ink composition. Solidification means that a substance (the ink composition in this embodiment) changes from a liquid to a solid. What is obtained by solidifying the ink composition is the dried solid, which corresponds to the reversible photochromic layer in this embodiment. The reversible photochromic layer may contain components (typically, a binder described later) contained in the ink composition or a reaction product thereof. The reversible photochromic layer can be formed by applying the ink composition to the substrate or a base layer described later.

[0024] Hereinafter, solidification without intentional chemical changes will be referred to as "drying solidification." After the application of the ink composition, the chemical hardening (polymerization) and solidification of the polymerizable vehicle (see below) will be referred to as "curing drying." Application means adhering the ink composition to the substrate. The method of adhesion is not limited and may be printing, coating, or other methods.

[0025] The reversible light-changing layer may be formed on the entire surface of the substrate or on only a portion of it. The reversible light-changing layer may be formed to represent, for example, figures such as circles, ellipses, squares, and rectangles; shapes such as people, animals, plants, fruits, food products, vehicles, buildings, and celestial bodies; various letters; symbols; and geometric patterns. These may be used individually or in combination of two or more types.

[0026] The thickness of the reversible color-changing layer is not particularly limited and is set appropriately so that reversible color changeability is achieved. For example, the thickness of the reversible color-changing layer is 0.5 μm or more and 2 μm or less. The thickness of the reversible color-changing layer may be 0.7 μm or more and 1 μm or more. The thickness of the reversible color-changing layer may be 1.5 μm or less and 1.3 μm or less.

[0027] The ink composition contains a reversible light-color-changing material. The ink composition may contain non-color-changing colorants such as general dyes and / or pigments. The ink composition may contain a non-color-changing white pigment such as titanium dioxide.

[0028] The reversible photochromic material contains a photochromic compound. The reversible photochromic material may further contain an oligomer.

[0029] The reversible photochromic material may be a reversible photochromic microcapsule comprising a wall film and a photochromic compound and oligomer encapsulated within the wall film. Hereinafter, an aggregate of reversible photochromic microcapsules (hereinafter referred to as "microcapsules") may be referred to as a "microcapsule pigment."

[0030] The reversible photochromic material may be reversible photochromic resin particles (hereinafter referred to as "resin particles") comprising a thermoplastic resin or a thermosetting resin and a photochromic compound and oligomer dispersed in the resin.

[0031] The reversible photochromic material may be in the form of microcapsules. Microcapsules are less susceptible to external influences and can exhibit the desired reversible photochromic properties over a long period of time.

[0032] • Microcapsules A microcapsule comprises a wall film and a photochromic compound and oligomer encapsulated within the wall film. Microcapsule pigments are aggregates of microcapsules (particles). Ink compositions containing microcapsule pigments reversibly change color.

[0033] ·Wall membrane The membrane is in the form of a tiny capsule (a shape with a closed space inside). The membrane forms the aforementioned internal space, separating it from the outside. The photochromic compound and oligomer are encapsulated within this internal space.

[0034] The wall film enhances the chemical and physical stability of the photochromic compound and protects it from various degradation factors. This ensures that the desired reversible photochromic properties are maintained over the long term.

[0035] The material of the wall film is not particularly limited. Examples of wall film materials include polyurea, polyamide, polyurethane, epoxy resin, melamine resin, urea resin, urea urethane resin, isocyanate resin, vinyl resin, gelatin, ethylcellulose, polyvinyl alcohol, and carboxymethylcellulose. These can be used individually or in combination of two or more.

[0036] The membrane (and microcapsules) are obtained by known methods. The membrane is manufactured by a method appropriate to its material, etc. For example, the membrane can be manufactured by interfacial polymerization, in situ polymerization, liquid curing coating, phase separation from aqueous solutions, phase separation from organic solvents, melt-dispersion-cooling, air suspension coating, or spray drying.

[0037] For example, microcapsules can be obtained using interfacial polymerization as follows. First, an emulsion is prepared by adding a system (oil phase) containing the encapsulation material and the wall material to an aqueous medium (aqueous phase) all at once or in stages and stirring. As stirring continues, the wall material polymerizes at the interface between the oil phase and the aqueous phase (interfacial polymerization reaction). At this time, the wall closes to hold the encapsulation material inside, forming a microcapsule. Finally, the microcapsules are separated from the aqueous phase, washed, and dried to isolate them.

[0038] A curing agent may be added to the reaction system. The reaction system may be heated. Desolvent removal may be performed during or after the interfacial polymerization reaction.

[0039] A coating layer may be provided on the surface of the wall film, depending on the purpose. The coating layer can further improve durability and modify surface properties. Examples of materials for the coating layer include those similar to those of the wall film. The materials of the wall film and the coating layer may be the same or different.

[0040] The mass ratio of the wall film to its inclusions (wall film:inclusions) may be, for example, 1:1 to 1:7. This mass ratio makes it easier to obtain the desired color density and clarity. The mass ratio (wall film:inclusions) may also be 1:1 to 1:6.

[0041] • Photochromic compounds Known photochromic compounds can be used. Examples of photochromic compounds include one or more selected from the group consisting of spirooxazine derivatives, spiropyran derivatives, and naphthopyran derivatives. Examples of photochromic compounds include those described in Japanese Patent Publication No. 2021-120493 and International Publication No. 2020 / 137469.

[0042] Photochromic compounds may have photomemory properties (color memory photochromic properties). Examples of photochromic compounds having photomemory properties include diarylethene derivatives. Examples of photochromic compounds having photomemory properties include the compounds described in Japanese Patent Application Publication No. 2021-120493.

[0043] • Oligomer The encapsulation may contain oligomers. The photochromic compound may dissolve in the oligomers. The oligomers may be present around the photochromic compound. The oligomers protect the photochromic compound from various degradation factors. The oligomers can maintain the reversible photochromic properties of the photochromic compound. The oligomers can assist in molecular structural changes of the photochromic compound and adjust its color change sensitivity. The oligomers increase the color intensity of the microencapsulated pigment. The oligomers also increase the lightfastness of the microencapsulated pigment.

[0044] Examples of oligomers include one or more selected from the group consisting of styrene-based oligomers, acrylic-based oligomers, terpene-based oligomers, and terpene phenol-based oligomers.

[0045] The styrene oligomer may have a mass-average molecular weight (Mw) of 200 to 6000. If the Mw of the styrene oligomer is 200 or higher, stability and light resistance may be improved. If the Mw of the styrene oligomer is 6000 or lower, the molecular structure of the photochromic compound changes more easily, allowing it to quickly revert to its original molecular structure when light irradiation stops. Therefore, color retention during fading is less likely to occur. Similarly, the molecular structure of the photochromic compound changes more easily due to light irradiation, making it easier to achieve higher color intensity. In addition, the color change sensitivity is easier to adjust. The Mw of the styrene oligomer may be 4000 or lower.

[0046] Styrene oligomers are compounds having a styrene skeleton or their hydrogenated derivatives. Examples of styrene oligomers include low molecular weight polystyrene, styrene-α-methylstyrene copolymers, α-methylstyrene polymers, and α-methylstyrene-vinyltoluene copolymers. These can be used individually or in combination of two or more.

[0047] Acrylic oligomers may have an Mw of 12000 or less. When the Mw of acrylic oligomers is 12000 or less, the color change sensitivity is easily adjustable. Acrylic oligomers may have an Mw of 1000 or more. When the Mw of acrylic oligomers is 1000 or more, stability is improved. In addition, the color intensity tends to increase and lightfastness may be further improved. Acrylic oligomers may have an Mw of 1000 to 12000. Acrylic oligomers may have an Mw of 1500 or more. Acrylic oligomers may have an Mw of 8000 or less, and may also have an Mw of 6000 or less.

[0048] Examples of acrylic oligomers include acrylic acid ester copolymers.

[0049] Terpene oligomers may have an Mw of 250 to 4000. If the Mw of the terpene oligomer is 250 or higher, stability and lightfastness may improve. If the Mw of the terpene oligomer is 4000 or lower, color retention during fading is less likely, and the color intensity tends to be higher. In addition, the color change sensitivity is easier to adjust. The Mw of the terpene oligomer may be 300 or higher.

[0050] Terpene oligomers have a terpene skeleton. Examples of terpene oligomers include α-pinene polymers, β-pinene polymers, and d-limonene polymers. These can be used individually or in combination of two or more.

[0051] Terpene phenol oligomers may have an Mw of 200 to 2000. If the Mw of terpene phenol oligomers is 200 or higher, stability improves and the color intensity may increase. If the Mw of terpene phenol oligomers is 2000 or lower, the color change sensitivity is easier to adjust. The Mw of terpene phenol oligomers may be 500 or higher. The Mw of terpene phenol oligomers may be 1200 or lower.

[0052] Terpene phenol oligomers are copolymers or hydrogenated products of cyclic terpene monomers and phenols. Examples of terpene phenol oligomers include α-pinene-phenol copolymers. These can be used individually or in combination of two or more.

[0053] The Mw of the above oligomers can be measured by gel permeation chromatography (GPC).

[0054] The mass ratio of the photochromic compound to the styrene-based oligomer or acrylic-based oligomer (photochromic compound:styrene-based oligomer / acrylic-based oligomer) may be, for example, 1:1 to 1:10000, or 1:5 to 1:500.

[0055] The mass ratio of the photochromic compound to the terpene oligomer (photochromic compound:terpene oligomer) may be, for example, 1:1 to 1:5000, or 1:5 to 1:500.

[0056] The mass ratio of the photochromic compound to the terpene phenol oligomer (photochromic compound: terpene phenol oligomer) may be, for example, 1:1 to 1:50, or 1:2 to 1:30.

[0057] When the mass ratio of the photochromic compound to the various oligomers is within the above range, the reversible photochromic properties of the photochromic compound are more easily maintained, and sufficient color intensity can be obtained.

[0058] ·others The inclusions may contain non-coloring agents such as general dyes and / or pigments. Non-coloring agents may cause an intermutation of color from a first color to a second color.

[0059] ·Average particle diameter (X) The average particle size (X) of the microcapsules based on volume is not particularly limited. The average particle size (X) may be between 0.1 μm and 3.0 μm. When the average particle size (X) is 0.1 μm or larger, a sufficient amount of photochromic compound can be encapsulated, further improving the color development of the reversible photochromic layer. In addition, aggregation of microcapsules is suppressed, making it difficult for coarse particles to form, thus reducing defects during application (e.g., printing defects). When the average particle size (X) is 3.0 μm or smaller, the dispersibility of the microcapsule pigment in the ink composition is improved, improving the quality of the reversible photochromic layer.

[0060] The average particle size (X) may be 0.3 μm or larger, or 0.5 μm or larger. From the viewpoint of dispersibility, the average particle size (X) may be 2.0 μm or smaller, or 1.5 μm or smaller. From the viewpoint of color development, the average particle size (X) may be 1.5 μm or smaller, or 1.0 μm or smaller. The average particle size (X) can be said to be the average diameter of the primary particles of the microcapsule.

[0061] In the printing industry, a white ink layer (white undercoat layer) is typically added beneath the printed layer to improve color reproduction. The white ink layer reduces the influence of the substrate, thereby enhancing color vibrancy.

[0062] The reversible light-changing layer containing microcapsule pigments having the above average particle size (X) exhibits a whitish appearance. This is thought to be because the small average particle size (X) of the microcapsules makes visible light more easily diffusely reflected. Therefore, the reversible light-changing layer can exert a so-called white-suppressing effect, further improving color development.

[0063] The whiteness of the reversible photochromic layer is thought to be caused by visible light being reflected (i.e., scattered) in various directions from the outer surface of the microcapsules. Since the average particle diameter (X) is about the same as or larger than the wavelength of visible light, much of the above scattering is thought to be Mie scattering. In Mie scattering, light of all wavelengths is scattered in the same way, so the whiteness is strongly expressed.

[0064] The average particle size (X) of the microcapsules is similar to or larger than the wavelength of visible light, while being smaller than conventional microcapsules. Therefore, Mie scattering is more likely to occur. Consequently, the reversible photochromic layer may exhibit a stronger whiteness.

[0065] While visible light is scattered on the outer surface of the microcapsules, some of the visible light is transmitted through the wall film. The visible light that enters the inside of the microcapsules acts on the photochromic compound, exhibiting reversible photochromicity.

[0066] (Method for calculating average particle size (X)) The particle size of the microcapsules is the equivalent diameter of an isovolume sphere, measured using a laser diffraction / scattering particle size distribution analyzer (e.g., LA-960V2, manufactured by Horiba, Ltd.) that has undergone a predetermined calibration.

[0067] The average particle size (X) is the average value of the equivalent diameter of an equal-volume sphere (the particle size D50, i.e., the median diameter, which corresponds to a frequency of 50% when the particle size distribution is determined based on volume).

[0068] The prescribed calibration will be explained. If the particle size of all microcapsules exceeds 0.20 μm, the average value of the equivalent diameter of an equivolute sphere is measured using the Coulter method with a particle size distribution analyzer (e.g., Multisizer 4e, manufactured by Beckman Coulter, Inc.), and calibration is performed based on that value.

[0069] In cases other than those described above, the microcapsule region is determined using image analysis-based particle size distribution measurement software (for example, MacView, manufactured by Mountec Co., Ltd.), the projected area equivalent diameter (Heywood diameter) is calculated from the area of ​​the microcapsule region, and calibration is performed based on the average value of these equivalent diameters of equivolute spheres.

[0070] The average particle size (X) can be controlled, for example, by the manufacturing conditions of microcapsules. In interfacial polymerization, increasing the stirring speed or lengthening the stirring time tends to decrease the average particle size (X).

[0071] To control the average particle size (X) to 0.1 μm to 3.0 μm, for example, microcapsules can be manufactured by interfacial polymerization using 0.5 to 25 parts by mass of wall film material for every 1 part by mass of encapsulation material.

[0072] Microencapsulated pigments may contain particles that are not perfectly spherical. Microencapsulated pigments may also contain particles with depressions on their surface. Particles with depressions on their surface may be observed, for example, as a double circle (an outer circle corresponding to the shape of the microcapsule and an inner circle corresponding to the shape of the depression) in a planar SEM image. Particles with depressions on their surface may have a larger contact area with the substrate than perfectly spherical particles, and thus may have improved adhesion to the substrate.

[0073] • Resin particles The resin particles are particles comprising a thermoplastic resin or a thermosetting resin, and a photochromic compound and oligomer dispersed in the resin.

[0074] Resin particles are produced by methods such as pulverization, spray drying, emulsion polymerization, suspension polymerization, suspension condensation, and dispersion polymerization.

[0075] Specifically, the resin particles are obtained by the following pulverization method. First, a thermoplastic resin, a photochromic compound, and an oligomer are melt-kneaded at a temperature above the melting point of the thermoplastic resin. Next, the mixture is cooled and solidified below the melting point of the thermoplastic resin to obtain a bulk mixed resin. The mixed resin is then coarsely crushed and pulverized to produce fine particles. Finally, resin particles are obtained by classification and drying.

[0076] Resin particles can also be obtained in the following way. First, a thermoplastic resin, a photochromic compound, and an oligomer are mixed and dissolved in a suitable solvent. Next, the solvent is removed to obtain a bulk mixed resin. The mixed resin is then coarsely crushed and pulverized to produce fine particles. Finally, resin particles are obtained by classification and drying.

[0077] Resin particles can also be obtained using emulsion polymerization. First, an emulsifier is dissolved in an aqueous medium to form micelles. Next, a system containing polymerizable monomers, a photochromic compound, and an oligomer (oil phase) is added to the system containing the emulsifier (aqueous phase) once or in stages and stirred to prepare an emulsion. A portion of the oil phase is incorporated into the micelles and solubilized, while another portion forms oil droplets without being incorporated into the micelles. A polymerization initiator is added to this mixed system. This causes radicals from the polymerization initiator to enter the micelles, initiating the reaction of the polymerizable monomers. As polymers are generated within the micelles, and polymerizable monomers are also supplied from the oil droplets, the polymer grows, and resin particles are formed. Finally, the resin particles are separated from the aqueous phase and isolated by washing and drying.

[0078] In emulsion polymerization, the reaction system may be heated. Desolvent removal may be performed during or after the emulsion polymerization reaction. Emulsifiers may not be used.

[0079] ·Thermoplastic resin Examples of thermoplastic resins include polystyrene, acrylic resins such as polymethyl methacrylate, polyester, polyvinyl chloride, polybutadiene, acrylic-urethane copolymer resins, polyethylene, polypropylene, polyacrylonitrile, polyacetal, ethylene-propylene copolymer resin, ethylene-vinyl acetate copolymer resin, styrene-acrylic copolymer resin, styrene-butadiene copolymer resin, styrene-acrylonitrile copolymer resin, and acrylonitrile-butadiene copolymer resin. These can be used individually or in combination of two or more.

[0080] ·Thermosetting resin Examples of thermosetting resins include epoxy resins, epoxy acrylate resins, xylene resins, toluene resins, guanamine resins, benzoguanamine resins, melamine resins, urethane resins, phenolic resins, alkyd resins, polyamides, polyimides, polyamide esters, urea resins, silicone resins, and unsaturated polyesters. These can be used individually or in combination of two or more.

[0081] • Polymerizable monomers Examples of polymerizable monomers include monovinylidene aromatic monomers such as styrene, vinyltoluene, tert-butylstyrene, chlorostyrene, vinylbenzyl chloride, and vinylpyridine; α,β-ethylenically unsaturated alkyl esters such as ethyl acrylate, methyl methacrylate, butyl acrylate, and 2-ethylhexyl acrylate; unsaturated esters of saturated carboxylic acids such as vinyl acetate; unsaturated halides such as vinyl chloride and vinylidene chloride; unsaturated nitriles such as acrylonitrile; dienes such as butadiene and isoprene; acrylic acid, sodium acrylate, methacrylic acid, etc. Examples include ethylenically unsaturated carboxylic acids such as taconic acid and maleic acid, or their salts; ethylenically unsaturated carboxylic acid amides such as acrylamide; hydroxyalkyl (meth)acrylates such as hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxyethyl methacrylate; unsaturated aminoalkyl esters such as 2-aminoethyl methacrylate; epoxy monomers such as glycidyl methacrylate; unsaturated sulfoalkyl compounds such as 2-sulfoethyl methacrylate; ethylenically unsaturated quaternary ammonium compounds such as vinylbenzyltrimethylammonium chloride; and vinylpyrrolidone. These can be used individually or in combination of two or more.

[0082] • Ink composition The ink composition includes, for example, a reversible photochromic material and a vehicle. The ink composition is prepared by mixing and stirring the components. The viscosity of the ink composition is not particularly limited.

[0083] The content of the reversible photochromic material may be, for example, 5% by mass or more and 45% by mass or less of the mass of the ink composition. The above content of the reversible photochromic material may be 10% by mass or more and 15% by mass or more. The above content of the reversible photochromic material may be 40% by mass or less and 35% by mass or less.

[0084] The vehicle comprises, for example, a binder, a solvent and / or water, and various additives as needed. The vehicle may be curable (polymerizable). The vehicle may be oxidatively polymerizable, thermosetting, ultraviolet curable, or electron beam curable.

[0085] ·binder The binder is an organic compound. The binder contains at least one of a polymerizable monomer, a polymerizable oligomer, and a polymer. The polymer may be polymerizable or nonpolymerizable.

[0086] Examples of polymers include non-drying oil alkyd resins, semi-drying oil alkyd resins, drying oil alkyd resins, urethane-modified alkyd resins, styrene-modified alkyd resins, acrylic-modified alkyd resins, epoxy-modified alkyd resins, phenol-modified alkyd resins, oil-free alkyd resins, acid-cured amino alkyd resins, rosin-modified alkyd resins, silicone-modified alkyd resins, rosin-modified phenol resins, rosin-modified maleic acid resins, acrylic resins, silicone-modified acrylic resins, alkyd-modified acrylic resins, cellulose acetate butyrate (CAB)-modified acrylic resins, acrylic polyols, epoxy resins, acrylic-modified epoxy resins, amine-modified epoxy resins, fluororesins, polycarbonate resins, amino resins, melamine resins, benzoguanamine resins, urea resins, isocyanate resins, chlorinated polyolefin resins, vinyl chloride resins, vinyl chloride copolymer resins, and vinylidene chloride resins. These can be used individually or in combination of two or more.

[0087] Examples of polymerizable monomers include epoxy acrylates, urethane acrylates, oligoester acrylates, and polyester acrylates. Other examples of polymerizable monomers include acrylate compounds with molecular weights of 100 to 800. Examples of acrylate compounds include 2-ethylhexyl acrylate, butanediol diacrylate, diethylene glycol diacrylate, tetraethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, neopentyl glycol acrylate benzoate, 2-acryloyloxyethyl acid phosphate, 2-hydroxyethyl acrylate, isooctyl acrylate, and benzyl acrylate. These can be used individually or in combination of two or more.

[0088] Examples of polymerizable oligomers include dimers, trimers, tetramers, and low molecular weight polymers (Mw 100-10000) of one or more of the polymerizable monomers mentioned above.

[0089] The solid content of the binder may be, for example, 30% by mass or more and 60% by mass of the mass of the vehicle. The above content of the binder may be 35% by mass or more and 40% by mass or more. The above content of the binder may be 55% by mass or less and 50% by mass or less.

[0090] • Solvents and / or water The vehicle contains at least one of a solvent and water. Examples of solvents include aliphatic hydrocarbons, aromatic hydrocarbons, alcohols, esters, and ketones. For offset printing, the solvent may be relatively slow-drying. Examples of slow-drying solvents (high-boiling point solvents) include industrial solvents, kerosene, Solvesso 100, Solvesso 150, xylene, mineral spirits, n-butanol, anone, isophorone, cellosolve, and cellosolve acetate. These can be used individually or in combination of two or more.

[0091] The content of the solvent and / or water may be, for example, 30% by mass or more and 60% by mass of the mass of the vehicle. The above content of the solvent and / or water may be 35% by mass or more and 40% by mass or more. The above content of the solvent and / or water may be 55% by mass or less and 50% by mass or less.

[0092] • Additives The vehicle may contain various additives. Examples of additives include thixotropy-inducing agents, wetting agents, coupling agents, curing agents, viscosity modifiers, extender pigments, antioxidants, UV absorbers, light stabilizers, polymerization inhibitors for dark-time stabilization, leveling agents, defoaming agents, adhesion-inducing agents, antistatic agents, preservatives and antifungal agents, flame retardants, and rust inhibitors.

[0093] Vehicles containing polymerizable binders may contain polymerization initiators and sensitizers. It is desirable that polymerization inhibitors and polymerization initiators do not coexist.

[0094] The vehicle may contain solid matter. The vehicle may contain extender pigments. Extender pigments improve the fluidity, opacity, gloss, and colorability of the ink composition. Examples of extender pigments include clay minerals such as clay (activated clay) and bentonite, calcium carbonate, and silica (white carbon). The extender pigment may contain at least one of clay minerals and silica. The extender pigment content may be 1% by mass or more and 30% by mass or less of the mass of the vehicle.

[0095] (Other layers) The coating may include an underlayer interposed between the substrate and the reversible light-coloring layer. The underlayer may be a layer that does not exhibit reversible light-coloring properties (an irreversible light-coloring layer). Examples of the underlayer include a white ink layer, an adhesive layer, and a sealing layer. The thickness of the underlayer is not particularly limited and is set appropriately according to the purpose, etc. The white ink layer contains a white pigment. The underlayer is formed, for example, by a coating method, a printing method, a lamination method, or a heat-pressing method.

[0096] The coating may include a transparent protective layer provided on the reversible photochromic layer. The transparent protective layer protects the microcapsule pigment from physical impact. Transparency means that the total light transmittance is 70% or higher. The total light transmittance can be measured by a method in accordance with JIS K 7361-1.

[0097] The transparent protective layer may contain a light stabilizer or a transparent metallic luster pigment from the viewpoint of light resistance. Examples of light stabilizers include ultraviolet absorbers, antioxidants, anti-aging agents, singlet oxygen quenchers, superoxide anion quenchers, ozone quenchers, visible light absorbers, and infrared absorbers. The transparent metallic luster pigment has, for example, a base material such as natural mica, synthetic mica, glass fragments, alumina, or transparent film fragments, and a metal oxide such as titanium oxide that coats its surface.

[0098] The thickness of the transparent protective layer is not particularly limited and is set as appropriate depending on the purpose. The transparent protective layer can be formed, for example, by coating, printing, lamination, or heat bonding.

[0099] The coating may include a layer formed on the substrate that does not exhibit reversible light-changing properties (an irreversible light-changing layer). The irreversible light-changing layer may be positioned below and adjacent to the reversible light-changing layer, or above and adjacent to the reversible light-changing layer, or may be formed on the same plane as the reversible light-changing layer. The irreversible light-changing layer may cause the coating to undergo an intermutation color change from a first color to a second color.

[0100] The thickness of the irreversible light-coloring layer is not particularly limited and can be set as appropriate depending on the purpose. The irreversible light-coloring layer can be formed, for example, by coating or printing.

[0101] [Method for manufacturing coated material] The reversible light-color-changing layer is formed by applying an ink composition to a substrate or underlayer. Typical methods of application include coating and printing. Coating methods include brush coating, spray coating, electrostatic coating, electrodeposition coating, flow coating, roller coating, and dipping coating. Printing methods include, for example, offset printing, screen printing, process printing, gravure printing, flexographic printing, and transfer printing. The reversible light-color-changing layer may be formed by offset printing.

[0102] The number of times the color is applied is not particularly limited and can be set appropriately according to the desired color density. The number of times it is applied may be once or two or more times.

[0103] After application, volatile components (typically solvents) contained in the vehicle are removed, and the ink composition is dried and solidified. From the viewpoint of improving the durability of the reversible photochromic layer, a polymerizable vehicle may be used to form the reversible photochromic layer by curing and drying.

[0104] The drying and solidification method is not particularly limited. Examples of drying and solidification methods include natural drying, heat drying, and hot air drying. The curing and drying method is appropriately selected depending on the properties of the vehicle. Examples of curing and drying methods include the addition of an oxidizing agent, heating, ultraviolet irradiation, and electron beam irradiation. Curing and drying may be carried out by heating.

[0105] When forming a reversible photochromic layer by heating using a polymerizable vehicle, the heating temperature may be between 150°C and 250°C. The heating process may be performed multiple times. For example, the first heating step (primary drying) removes the solvent contained in the ink composition to obtain a touch-dry or semi-dried reversible photochromic layer. Primary drying suppresses color transfer of the ink composition and improves the handling properties of the coated object. Subsequently, the vehicle within the reversible photochromic layer is chemically cured in a second heating step (secondary drying).

[0106] The primary drying temperature and the secondary drying temperature may be the same or different. The secondary drying temperature may be higher than the primary drying temperature. This facilitates the curing of the vehicle and improves the durability of the reversible photochromic layer.

[0107] [Applications of laminates] The coatings described herein can be used in a variety of applications. Examples of applications are given below, but are not limited to these.

[0108] (A medium for displaying ultraviolet radiation levels) The coatings of this disclosure are used in a medium for displaying ultraviolet (UV) radiation levels. The reversible photochromic layer used in this disclosure increases in color intensity as the amount of light irradiation increases. That is, the cumulative amount of irradiated UV radiation is visualized. The UV radiation level display medium has a coating on at least a part of it. The entire UV radiation level display medium may be formed from the coating. The UV radiation level display medium and the coating may be molded together or may be separate components.

[0109] (container) The coverings of this disclosure are used for containers. The container has the covering on at least a part of it. The entire container may be formed from the covering. The container and the covering may be molded together or they may be separate.

[0110] The container has a shape that allows it to hold and remove various contents. Specifically, the container may be a bottomed cylindrical shape.

[0111] The contents are not particularly limited. Examples of contents include liquid industrial products such as paints, inks, fuels, industrial oils and solvents; gases; tools; electronic equipment; cosmetics; perfumes; pharmaceuticals; chemicals such as pesticides and fire extinguishing agents; and food and beverages. The contents may be food or beverages. Food or beverages may be served in places where they are visible to many people. Food or beverages are also expected to play a role in improving the atmosphere of the place and providing conversation topics. Therefore, the appearance of the containers for food or beverages greatly influences purchasing intent. Containers equipped with a reversible light-changing layer have high design appeal and can meet the above expectations. Examples of beverages include alcoholic beverages such as beer and soft drinks such as juices.

[0112] In particular, it may be a container for holding food or beverages. The reversible light-coloring layer is formed, for example, on the outer surface of the container (or the outer surface if it is cylindrical).

[0113] (toy) The coverings of this disclosure are used in toys. The toys have the coverings on at least a part of them. The entire toy may be formed from the coverings. The toy and the coverings may be molded together or they may be separate.

[0114] Examples of toys include dolls or animal-shaped toys; dollhouses, furniture, hats, bags, or shoes; accessory toys; toys that imitate vehicles, plants, buildings, or food; and drones.

[0115] The toy may be, for example, a toy that imitates a vehicle (a die-cast miniature car). The toy that imitates a vehicle may be manufactured, for example, by die-casting, or by applying aluminum vapor deposition to a casting or plastic surface manufactured by die-casting. The toy that imitates a vehicle equipped with the coating of this disclosure has a sense of weight and realistic texture, as well as a clear color change when exposed to light, and has a high level of design appeal.

[0116] The toy may be, for example, a drawing toy. The drawing toy comprises, for example, a board having the covering of the present disclosure and a pen having a light source. The light emitted from the pen causes the covering to light up in the path of the pen, allowing any image to be drawn. The drawing toy having the covering of the present disclosure can draw vividly colored images.

[0117] (Outdoor goods) The coverings of this disclosure are used for outdoor articles. The outdoor article has the covering on at least a part of it. The entire outdoor article may be formed of the covering. The outdoor article and the covering may be molded together or they may be separate.

[0118] Outdoor articles are articles installed outdoors or articles primarily used outdoors. Outdoor articles equipped with the coverings of this disclosure appear differently during the day when sunlight is shining on them and at night when sunlight is not shining on them, allowing for enjoyment of this change. These articles also have excellent design appeal because they display vivid colors during the day.

[0119] Examples of outdoor items include the following: (1) Transportation equipment Automobiles, trains, helicopters, airplanes, ships, motorcycles, bicycles, mopeds, snowmobiles, cable cars, lifts, hovercraft, strollers, wheelchairs (2) Building materials Window frames, shutters, blinds, water tanks, doors, balconies, building exterior panels, roofing materials, stairs, mailboxes, lath, signs (3) Road components Building exteriors, pedestrian bridges, signs, highway side walls, railway viaducts, bridges (4) Plant equipment Tanks, pipes, towers (5) Agricultural equipment Greenhouses, silos, sprinklers (6) Fire extinguishing equipment Fire extinguishers, fire hydrants, fire hoses, fire hose nozzles, sprinkler systems, hose storage boxes (7) Communication equipment Power transmission towers, parabolic antennas (8) Electrical equipment Covers for electrical wiring boxes, lighting fixtures, and various electrical equipment. (9) Others Monuments, navigational aids, pallets, turntables, traversers, nameplates, license plates, water pipes, ladders, step ladders, sports equipment, mountaineering equipment, fishing gear, parasols, pet supplies

[0120] (Forgery prevention medium) The coverings of this disclosure are used in anti-counterfeiting media. The anti-counterfeiting media has the covering on at least a portion of it. The entire anti-counterfeiting media may be formed by the covering. The anti-counterfeiting media and the covering may be molded together or may be separate.

[0121] For example, if the coating of this disclosure is placed on a genuine product, its color will change when exposed to light, thus confirming its authenticity. Because the color change of the coating of this disclosure is clear, authenticity can be easily determined. In addition, when light is not irradiated, it is difficult to notice that the coating has a reversible photochromic layer, making it difficult for a third party to duplicate it.

[0122] (Other items) The coverings of this disclosure are used on articles other than those described above. Other articles may have coverings on at least a portion of them. The entire other article may be formed by the covering. The other article and the covering may be molded together or separately.

[0123] Other items include, for example, bags, packaging containers, stationery, electronic devices, ornaments, and stickers.

[0124] Examples of electronic devices include mobile phones, smartphones, smartwatches, smart glasses, earphones, headphones, personal computers, cameras, speakers, games, protective cases for various electronic devices, and covers for various electronic devices.

[0125] Examples of jewelry include rings, bracelets, tiaras, necklaces, earrings, piercings, hair clips, false nails, watches, glasses, keychains, cufflinks, and tie clips.

[0126] Examples of stickers include various types of stickers used for decoration, packaging, and advertising. [Examples]

[0127] The embodiments of the present invention will be described in more detail below with reference to examples. The embodiments of the present invention are not limited by the following examples, and can be implemented with appropriate modifications within the scope that is consistent with the spirit described above and below, and all such modifications are included within the technical scope of the embodiments of the present invention.

[0128] [Example 1] (1) Preparation of the materials for the inclusions Five parts by mass of a photochromic compound (1,3,3-trimethyl-6′-(1-morpholino)-spiroindoline naphthoxazine) and 50 parts by mass of a styrene oligomer (styrene-α-methylstyrene copolymer, Mw: 317, manufactured by Eastman Chemical Company, product name: Picorastic A-5) were mixed, and the photochromic compound was dissolved by heating to obtain the material for the encapsulation.

[0129] (2) Fabrication of microcapsules Microcapsules were fabricated using the obtained encapsulated material by interfacial polymerization. First, 5 parts by mass of the encapsulation material was added to a mixed solution of 30 parts by mass of the wall material (aromatic isocyanate prepolymer) and 70 parts by mass of ethyl acetate. This was emulsified and dispersed in a 15% by mass gelatin aqueous solution, and stirred at a speed of 6500 rpm while heating to prepare a microcapsule dispersion. Finally, a microcapsule aggregate (microcapsule pigment) was obtained from the above microcapsule dispersion by centrifugation.

[0130] The average particle size (X) of the obtained microcapsules was 2.0 μm. The average particle size (X) was calculated as described above.

[0131] (Confirmation of reversible photochromicity) Two parts of the obtained microcapsule pigment and four parts of water were mixed to prepare an aqueous dispersion of the microcapsule pigment, which was then placed in a screw-capsule vial. Using a light irradiation device (Optcode Co., Ltd., product name: Select 100 LED Stand Light), the screw-capsule vial was irradiated with violet light at a wavelength of 405 nm for one minute. The distance between the light source and the screw-capsule vial was 10 cm. The microcapsule pigment was colorless before irradiation with violet light, but changed to violet after irradiation. After being left in the room for a while, it returned to being colorless. This confirmed that the microcapsule pigment changes color upon irradiation with violet light, and that this color change is reversible.

[0132] (3) Preparation of ink composition An ink composition was obtained by mixing 40 parts of microcapsule pigment, 52 parts of ethylene-vinyl acetate copolymer resin emulsion, 5 parts of viscosity modifier, and 3 parts of leveling agent.

[0133] (4) Preparation of covering An aluminum plate was prepared as the substrate. A solid pattern was printed onto the aluminum plate using an ink composition via screen printing. After that, it was left to stand at room temperature (approximately 23°C) to form a reversible photochromic layer.

[0134] [Color development evaluation 1] We evaluated the differences in color development due to differences in substrates. Samples were prepared using the ink composition obtained in Example 1, and the color development of these samples was evaluated. Color development was evaluated by the color density of the reversible photochromic layer after light irradiation. The evaluation results are shown in Table 1. A higher color density indicates that the reversible photochromic layer is more strongly colored, and therefore the color development is higher.

[0135] • Measurement of the light reflectance of the substrate First, a UV-Vis spectrophotometer (manufactured by JASCO Corporation, product name: V-670) was used to measure the baseline in the wavelength range of 300-700 nm using a standard white plate at a scanning speed of 2000 nm / min. Next, various substrates were placed on a sample stage, and violet light with a wavelength of 405 nm (*1) was irradiated using a light irradiation device (Optcode Co., Ltd., product name: Select 100 LED Stand Light), and the light reflectance at a wavelength of 405 nm was measured. The distance between the light source and the substrate was 10 cm.

[0136] (*1) The photochromic compound of Example 1 develops color when exposed to ultraviolet light and violet to blue light with peak emission wavelengths of 400 nm to 495 nm. Considering the usage environment, the substrate was irradiated with light with a peak emission wavelength of 405 nm, which is near the boundary between ultraviolet and visible light.

[0137] • Sample preparation Using the ink composition obtained in Example 1, a solid pattern was printed onto a PET film by screen printing. Then, by allowing it to stand at room temperature (approximately 23°C), a reversible photochromic layer with a thickness of 75 μm was formed. This resulted in obtaining a sample comprising a PET film and a reversible photochromic layer.

[0138] • Measurement of color density Samples were placed on various substrates to create simulant coatings 1-8. These simulant coatings were set on the sample stage of the same UV-Vis spectrophotometer as described above, and irradiated with 405 nm purple light for 3 seconds using a light irradiation device (Optcode Co., Ltd., product name: Select 100 LED stand light) to fully develop the reversible photochromic layer. The distance between the light source and the sample was 10 cm.

[0139] Subsequently, the sample was quickly placed in a fluorescence spectrometer (Konica Minolta, Inc., product name: FD-7) and the cyan, magenta, and yellow concentrations (*2) were measured.

[0140] (*2) The above photochromic compound emits color in purple to blue light when irradiated with light at a peak emission wavelength of 405 nm, so cyan, magenta, and yellow, which constitute the purple color, were measured.

[0141] [Table 1]

[0142] Table 1 shows that, when the amount of photochromic compound used is the same, the color density increases when the light reflectance of the substrate is 30% or higher. For example, a cyan color density of 0.85 or higher, a magenta color density of 1.10 or higher, and a yellow color density of 0.46 or higher indicates that the color change due to light irradiation is sufficiently visible. In particular, when 5 parts by mass of photochromic compound are used for 50 parts by mass of styrene oligomer, the fact that each color density satisfies the above conditions indicates high color development.

[0143] [Example 2] (2) Microcapsules with an average particle size (X) of 3.3 μm were prepared in the same manner as in Example 1, except that 1 part by mass of the photochromic compound was used and the stirring speed was set to 5000 rpm. The ink composition was prepared in the same manner as in Example 1, except that these microcapsules were used, and a coating was obtained.

[0144] [Example 3] (2) Microcapsules with an average particle size (X) of 0.53 μm were prepared in the same manner as in Example 1, except that 1 part by mass of the photochromic compound was used and the stirring speed was 10,000 rpm. An ink composition was prepared in the same manner as in Example 1, except that these microcapsules were used, and a coating was obtained.

[0145] [Color development evaluation 2] We evaluated the differences in color development due to differences in the average particle size (X) of microencapsulated pigments. Two samples were prepared using the ink compositions obtained in Examples 2 and 3, and their color development was evaluated. Color development was evaluated by the color density, measured in the same manner as above, and the light reflectance of the reversible color-changing layer. A lower light reflectance of the reversible color-changing layer indicates that the layer absorbs more light, and therefore the color development is higher. The evaluation results are shown in Table 2.

[0146] • Sample preparation Using the ink compositions obtained in Examples 2 and 3, solid patterns were printed onto PET films by screen printing. The films were then left to stand at room temperature (approximately 23°C) to form a 75 μm thick reversible photochromic layer. This yielded two samples, each comprising a PET film and a reversible photochromic layer.

[0147] • Measurement of the light reflectance of the reversible light-changing layer The sample was placed on an aluminum plate to create dummy coatings 9 and 10. The dummy coatings 9 and 10 were set on a sample stage, and a light irradiator (Optcode Co., Ltd., product name: Select 100 LED stand light) was used to irradiate the sample with violet light at a wavelength of 405 nm to fully develop the reversible photochromic layer. The distance between the light source and the sample was 10 cm. After that, the irradiation was stopped, and the light reflectance of the developed reversible photochromic layer at a wavelength of 585 nm (*3) was measured. Figure 1 shows the measured reflectance spectrum.

[0148] (*3) The absorption peak wavelength of the above photochromic compound shifts to around 580 nm when irradiated with violet light. Therefore, the light reflectance at a wavelength of 585 nm was measured.

[0149] [Table 2]

[0150] Tables 2 and 3 and Figure 1 show that the smaller the average particle size (X) of the microcapsules, the lower the light reflectivity and the higher the color density. In other words, the color development is enhanced. This is thought to be because the smaller the average particle size, the more easily light is absorbed by the reversible photochromic layer.

[0151] The lower color densities of coatings 9 and 10 compared to coatings 1-5 shown in Table 1 are due to the smaller amount of photochromic compound used. In coatings 9 and 10, where 1 part by mass of the photochromic compound was used per 50 parts by mass of styrene oligomer, the cyan color density was 0.40 or higher, the magenta color density was 0.50 or higher, and the yellow color density was 0.20 or higher, indicating that the color change upon light irradiation is sufficiently visible.

[0152] To solve the above problems, the present invention provides the following embodiments. [1] A substrate containing metal and having a light reflectance of 30% or more, The substrate comprises a reversible photochromic layer which is a dried product of an ink composition containing a reversible photochromic material, The aforementioned reversible photochromic material is a reversible photochromic laminate containing a photochromic compound. [2] The reversible photochromic material further comprises an oligomer, wherein the reversible photochromic laminate of [1] is described above. [3] The reversible photochromic laminate of [2], wherein the reversible photochromic material is a reversible photochromic microcapsule comprising a wall film and the photochromic compound and oligomer encapsulated in the wall film. [4] The reversible photochromic laminate according to [3] above, wherein the average particle size (X) of the microcapsules on a volume basis is 0.1 μm to 3.0 μm. [5] The reversible photochromic laminate of [2], wherein the reversible photochromic material is a reversible photochromic resin particle comprising a thermoplastic resin or a thermosetting resin and the photochromic compound and the oligomer dispersed in the resin. [6] A reversible photochromic laminate according to any of the above [1] to [5], wherein the metal is at least one selected from the group consisting of aluminum, aluminum alloys, iron, and iron alloys. [7] A reversible photochromic laminate according to any of the above [1] to [5], wherein the substrate is the material to be printed. [8] A container having any of the reversible photochromic laminates described in [1] to [7] above. [9] A container for holding food or beverages, as described in [8] above.

[10] A toy having any of the above [1] to [7] reversible photochromic laminates.

[11] An outdoor article having any of the reversible photochromic laminates described in [1] to [7] above.

[12] A counterfeit prevention medium having any of the reversible photochromic laminates described in [1] to [7] above. [Industrial applicability]

[0153] This invention provides a reversible photochromic laminate comprising a metal-containing substrate and exhibiting excellent color development.

Claims

1. A substrate containing metal and having a light reflectance of 30% or more, The substrate comprises a reversible photochromic layer which is a dried product of an ink composition containing a reversible photochromic material, The aforementioned reversible photochromic material is a reversible photochromic laminate containing a photochromic compound.

2. The reversible photochromic laminate according to claim 1, wherein the reversible photochromic material further comprises an oligomer.

3. The reversible photochromic laminate according to claim 2, wherein the reversible photochromic material is a reversible photochromic microcapsule comprising a wall film and the photochromic compound and oligomer encapsulated in the wall film.

4. The reversible photochromic laminate according to claim 3, wherein the average particle diameter (X) of the microcapsules on a volume basis is 0.1 μm to 3.0 μm.

5. The reversible photochromic laminate according to claim 2, wherein the reversible photochromic material comprises a thermoplastic resin or a thermosetting resin, and reversible photochromic resin particles dispersed in the resin, the photochromic compound and the oligomer.

6. The reversible photochromic laminate according to any one of claims 1 to 5, wherein the metal is at least one selected from the group consisting of aluminum, aluminum alloys, iron, iron alloys, zinc, and zinc alloys.

7. The reversible photochromic laminate according to any one of claims 1 to 5, wherein the substrate is a printed material.

8. A container having the reversible photochromic laminate according to claim 1.

9. A container for holding food or beverages, according to claim 8.

10. A toy having a reversible photochromic laminate as described in claim 1.

11. An outdoor article having the reversible photochromic laminate according to claim 1.

12. An anti-counterfeiting medium having a reversible photochromic laminate as described in claim 1.

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