JP5009664B2 - Variable color sheet and variable color wall decoration - Google Patents

Description

The present invention relates to a variable color sheet configured to be able to change an atmosphere by changing a color visually recognized, for example, between day and night. More specifically, a variable color sheet configured to appear to change its color tone by irradiating various external light sources such as sunlight, fluorescent light, incandescent light bulb, and the like, and using this as a wallpaper material The present invention relates to a variable color wall surface decoration material.

  Conventionally, various articles are known to exhibit different shades due to changes in external stimuli.

For example, it is known that wallpaper, wall cloth, plaster, wall paint, and the like used as interior decoration materials give different atmospheres during the day and at night. More specifically, for example, in Japan, there is a tendency to prefer white-based wall decoration materials, and such white-based wall decoration materials are generally bright indoors in daylight sunlight. Can be provided. However, the above-mentioned wall decoration material mainly composed of white does not have a bright white composition that was obtained during the day, but has a slightly dark, cold impression when the light source is a fluorescent or incandescent bulb at night. It tends to be recognized as giving white.

In this way, in the same article, the perceived color tone changes due to a change in external stimulus, that is, the light source irradiated from sunlight to a different light source such as a room light such as a fluorescent lamp or an incandescent lamp. Is called color rendering.

  Techniques for changing the color tone of articles by actively utilizing the color rendering properties have been studied. For example, it is known that certain rare earth element oxides exhibit specific absorption peaks at specific wavelengths in the visible light region. Attempts have been made to utilize the fact that the hue that is reflected and visible to the human eye looks different due to the change in the wavelength distribution of the irradiated light source using the rare earth element. This is based on the fact that when a light source with a different spectral distribution is irradiated to an object, a color rendering phenomenon with a different color appearance is used. When the light source is irradiated, it is used that each color appears to change in accordance with the wavelength distribution of the light source.

For example, in Patent Document 1 below, oxides of holmium (hereinafter also referred to as “Ho”), neodymium (hereinafter also referred to as “Nd”), and praseodymium (hereinafter also referred to as “Pr”) are visible light. It has been reported that it has a specific absorption peak in the region and develops color rendering properties because the intensity of absorbed light changes with changes in the external light source.

  In addition, the following Patent Document 2 discloses a ceramic product capable of exhibiting color rendering properties, and, like Patent Literature 1, using Ho, Nd, and Pr oxides, and mixing them with ceramics provides the color rendering properties. There is a description about the pottery you have.

Patent Document 3 below discloses an invention relating to a thermoplastic resin composition having reversible discoloration obtained by adding polyorganosiloxane to ABS-based resin or polycarbonate-based resin and blending holmium oxide fine particles. . The invention disclosed in Patent Document 3 is that, when kneading holmium oxide into a polycarbonate resin, polyorganosiloxane is also blended at the same time to prevent foaming during kneading and improve mechanical strength and thermal stability. And relates to a technique for kneading holmium oxide into the resin.

In addition to color rendering properties, various chromic materials are known as materials whose color tone is changed by an external stimulus.

For example, a photochromic material emits light of another wavelength when a compound is excited by irradiation with light of a specific wavelength and returns to a steady state, and a thermochromic material is heated by heat. The compound is denatured and develops as a different color. Further, the electrochromic material is modified by electrical stimulation and develops different colors.

Under such circumstances, the sheet material is a variable chromaticity in which a color change is caused by an external stimulus, and the color change appears instantaneously and is visually recognized, and the color tone before and after the change is changed. There has been a need for a variable color sheet material having a preferred hue. In particular, it has been demanded to provide a wall decoration material in which a change in color tone is preferably recognized during the daytime when sunlight is a light source and at night when an incandescent bulb or a fluorescent lamp is a light source.

JP 11-246219 A JP 2002-255673 A JP 2001-294725 A

However, Patent Document 1 discloses only the spectral characteristics of a material capable of exhibiting color rendering properties and a method for producing the material itself, and does not describe a specific use.

  Patent Document 2 only describes a method for preventing deterioration of the material at a high temperature when a rare earth element is mixed in the ceramic and fired at a high temperature. , Which relates to a molded product obtained by adding holmium oxide fine particles and polyorganosiloxane to a thermoplastic resin, and merely discloses a mixture of the thermoplastic resin and the fine particles, both of which are used as sheets. There was no mention about the use of.

  In addition, the color rendering reaction obtained by utilizing the oxides of the specific rare earth elements disclosed in Patent Documents 1 to 3 should confirm the change in the color tone by visual observation, although the color tone changes instantaneously. Was difficult and did not show sufficient color rendering properties to be required as a wall decoration material.

In addition, none of the chromic materials described above has a slow response speed and does not react instantaneously, and has a limited service life due to material durability problems, and a long-term variable color effect cannot be expected. In particular, the photochromic material, like the rare earth element, exhibits a variable color property due to the difference in the light source. However, since it is an organic compound, there is a problem in weather resistance and heat resistance.

  The present invention has been made in view of the above problems, and is a variable color sheet material in which a color tone change occurs due to an external stimulus, and the color tone change instantly appears and is clearly recognized visually. In addition, an object of the present invention is to provide a sheet material of variable chromaticity having a hue with favorable color tone before and after the change.

The present invention is a variable color sheet utilizing the color rendering properties exhibited by a specific rare earth element, and a reflective layer is laminated on a variable color coloring layer formed by including a specific rare earth element in a synthetic resin. Of the light irradiated to the variable chromatic coloring layer, the light transmitted through the variable chromatic coloring layer is reflected by the reflective layer, and is again transmitted through the variable chromatic coloring layer. It is.

That is, the present invention
(1) A base material, a reflective layer, and a variable chromatic coloring layer are laminated in this order,
On one surface of the variable color coloring layer containing at least one oxide of rare earth elements selected from holmium (Ho), neodymium (Nd), and erbium (Er) in the synthetic resin, A reflective layer having reflectivity in the visible light region is laminated,
The solar reflectance in the visible light region of the reflective layer is 70% or more,
The thickness of the variable chromatic coloring layer is 50 to 200 μm,
A variable chromaticity sheet characterized in that the hue changes depending on the light source ,
( 2 ) The variable color sheet according to (1) above, wherein the solar radiation transmittance in the visible light region of the variable color layer is 60% or more,
( 3 ) The variable color sheet according to the above (1) or (2) , wherein the reflective layer is located on a wall member side, and the variable color colored layer is located outside the reflective layer. Variable color wall decoration, characterized by being used
Is a summary.

  In the present invention, the “visible light region” means a wavelength region of about 380 nm to about 780 nm. “Having reflectivity in the visible light region” means that a significant solar reflectance is shown in the visible light region.

  The “sunlight reflectance” refers to the reflectance defined in JIS-A-5759.

  The present invention provides a variable color coloring layer comprising a synthetic resin containing an oxide of a rare earth element selected from holmium (Ho), neodymium (Nd), and erbium (Er) capable of exhibiting preferable color rendering properties. In addition, the use of incident light can be improved by laminating a reflective layer capable of reflecting light in the visible light range. That is, when light is irradiated from the variable chromatic coloring layer side, the light transmitted without being reflected or absorbed by the variable chromatic coloring layer is reflected by the reflecting layer, and the reflected light is reflected as the incident light. Succeeded in increasing the amount of light absorbed by the rare earth element oxide by re-entering the tunable colored layer from the opposite direction.

  As a result, the variable color sheet of the present invention and the variable color wall surface decoration material using the same sufficiently exhibit the color rendering properties due to the presence of the rare earth elements, and the hues that change due to the difference in the light source are all beautiful. And clearly visible. Moreover, unlike a chromic material, the color tone can be changed instantaneously.

  Furthermore, among the light reflected by the reflective layer, the light transmitted through the variable chromatic coloring layer is visually recognized as reflected light, so that the brightness of the surface of the variable chromatic coloring layer can be improved. Therefore, when decorating indoor walls using the wall surface decorating material of the present invention, it is possible not only to provide a wall surface with high brightness and beautiful color tone in daylight, but also at night. Even under a light source such as a fluorescent lamp or white light, it is possible to provide a wall having good lightness and a color tone clearly different from that of the daytime.

The best mode for carrying out the present invention will be described below.

(About variable chromatic coloring layer)
The variable color sheet of the present invention is a laminated structure formed by laminating at least a variable color coloring layer and a reflective layer. The variable color coloring layer is formed by adding a rare earth element oxide to a synthetic resin, and exhibits color rendering properties.

About rare earth elements:
The present inventors have examined various substances, particularly rare earth elements, and holmium (Ho), neodymium (Nd), or erbium (Er) oxide has a plurality of absorption peaks in the visible light region, and irradiation is performed. Depending on the type of the light source to be produced, the result is that the color is different and shows a beautiful color, and these oxides are included in the variable color coloring layer of the present invention. If any one of the above three types of oxides is used, it is possible to obtain a sheet exhibiting a color tone peculiar to each oxide, and further to obtain a sheet exhibiting a more subtle color. It is also possible to add any combination.

In addition, other rare earth elements such as praseodymium (Pr), which has been known to exhibit a color rendering effect, have been studied in the same manner. However, since the hues exhibited under various light sources are all dark and light, preferred hues. I found it difficult to say. In addition, an effective color rendering property cannot be obtained with a small addition amount. On the other hand, when the addition amount is increased, the lightness is lowered and a darker color tone is visually recognized. In particular, when the sheet of the present invention is used as a wall decoration material, a desirable effect cannot be obtained, and thus it was excluded from the rare earth elements constituting the present invention.

The Ho oxide (Ho ₂ O ₃ ) has major absorption peaks in the vicinity of 460 nm, 540 nm, and 650 nm in the visible light region. For this reason, it appears light yellow when irradiated with sunlight, appears almost white when irradiated with light from a normal fluorescent lamp (day white), and dark pink when irradiated with light from a three-wavelength light emitting fluorescent lamp (day white) To orange.

The Nd oxide (Nd ₂ O ₃ ) exhibits a light mauve color with sunlight and a light blue color with a three-wavelength light-emitting fluorescent lamp (day white).

In addition, the above-mentioned Er oxide (Er ₂ O ₃ ) exhibits a light pink color in sunlight and an orange color when irradiated with light from a three-wavelength light-emitting fluorescent lamp (lunch white).

As described above, the rare earth element oxide contained in the variable color coloring layer of the present invention exhibits a bright and beautiful color tone with respect to sunlight or a light source commonly used in daily life.

As the rare earth element oxide used in the present invention, those produced by various conventionally known methods can be arbitrarily selected and used. As an example of the production method, any metal or a compound of hydroxide, carbonate, oxalate or the like of these metals is heated and vaporized by a plasma method, and the vapor of the rare earth metal is oxidized and cooled. Examples thereof include a method for producing an oxide. In particular, the direct current arc plasma method is the most preferred production method from the viewpoint of productivity.

The direct current plasma arc method uses the rare earth metal raw material as an anode electrode, generates a plasma flame of argon gas from the cathode electrode, heats and evaporates the raw material, oxidizes and cools the metal vapor, thereby reducing the particle size. It becomes possible to produce oxide particles that are small to some extent.

The average particle diameter of the rare earth element oxide is preferably in the range of 0.1 μm to 20 μm, more preferably 0.5 μm to 10 μm. When the average particle diameter of these rare earth element oxides exceeds 20 μm, the change in color tone according to the type of external light source becomes small, and sufficient color rendering properties cannot be exhibited, which is not preferable. Moreover, when the said average particle diameter is less than 0.1 micrometer, since particle | grains are easy to aggregate, it is unpreferable.

The purity of the rare earth element oxide is preferably 95 to 100% and more preferably 99 to 100% in order to exhibit high color rendering properties.

The addition amount of the rare earth element oxide contained in the variable color coloring layer in the present invention can be arbitrarily determined in consideration of the degree of color tone change desired in the sheet. Generally, when the addition amount is increased, a sheet having a large degree of change in color tone under various light sources can be obtained. Holmium, neodymium, and erbium do not have the possibility of lightness being reduced to an unfavorable extent by increasing the amount of addition as in the case of praseodymium described above.
However, mainly for economic reasons, it is desirable to reduce the addition amount of the rare earth element as much as possible within a range in which a desired color change can be exhibited. Here, in the case of the variable color sheet of the present invention, a reflective layer described later is laminated on the variable color layer, so that even if the addition amount of the rare earth element is small, preferable color tone change and lightness are exhibited. It is possible to squeeze. More specifically, it is 0.5 parts by weight or more and 10 parts by weight or less, more preferably 1.0 part by weight or more and 5.0 parts by weight or less with respect to 100 parts by weight of the synthetic resin constituting the variable color coloring layer. With the addition amount, it is possible to constitute the variable chromatic coloring layer of the present invention.

About synthetic resins:
As the synthetic resin constituting the variable color coloring layer in the present invention, a conventionally known synthetic resin can be appropriately selected and used as long as it is a synthetic resin that contains the rare earth element and can be molded into a sheet shape. In particular, polyvinyl chloride resin, polyolefin resin, acrylic resin, and the like are selected as preferable synthetic resins.

Examples of the polyvinyl chloride resin include polyvinyl chloride, copolymers of vinyl chloride and other monomers such as vinyl acetate, ethylene, propylene, alkyl vinyl ether, acrylic acid ester, methacrylic acid ester, acrylonitrile, and the like. Mixtures of vinyl chloride and other polymers can be used.

Examples of the polyolefin resin include homopolymers such as polyethylene and polypropylene, olefin monomers such as ethylene and propylene, and other monomers such as vinyl acetate, α-olefin, acrylic acid ester, methacrylic acid ester, alkyl vinyl ether, and acrylonitrile. In addition to these copolymers, mixtures of polyethylene and polypropylene with other polymers can be used.

As said acrylic resin, homopolymers, such as acrylic acid, acrylic ester, and methacrylic ester, and 2 or more types of copolymers chosen from these monomers can be used. Further, a copolymer with a monomer copolymerizable with the above monomer, for example, acrylonitrile, butadiene or the like can be used.

Of the above-mentioned synthetic resins, soft polyvinyl chloride added with a plasticizer is particularly preferably used, and it is more preferable to use a paste resin characterized by emulsion polymerization of a polyvinyl chloride resin.

About other additives:
In addition to the oxide of the specific rare earth element, other additives can be added to the synthetic resin constituting the variable chromatic coloring layer as necessary. Examples of other additives include various additives such as colorants, plasticizers, stabilizers, surfactants, lubricants, foaming agents, ultraviolet absorbers, light stabilizers, antioxidants, and fillers. it can. Hereinafter, these additives will be described in more detail.

  As the colorant, a conventionally known pigment or dye may be used. In order to exhibit a more subtle color tone in the hue exhibited by the rare earth element oxide, it is mixed with a synthetic resin together with the rare earth element oxide. Can do. In such a case, if a colorant having a high degree of coloring and a large hiding property is selected, the color rendering property of the rare earth element may be difficult to be visually recognized on the sheet surface. It is necessary to determine the amount of addition. In particular, the use of a highly concealing colorant such as titanium oxide, zinc oxide, or carbon black is not suitable as a colorant because it may reduce the effect of color rendering.

Plasticizers include phthalate plasticizers such as di-2-ethylhexyl phthalate; phosphate plasticizers such as tricresyl phosphate; epoxy plasticizers such as epoxidized soybean oil; di-2-ethylhexyl adipate Those selected from fatty acid ester plasticizers such as trimellitic acid ester plasticizers and polyester plasticizers can be used as additives.

Stabilizers include metal salts of higher fatty acids such as barium stearate; metal salts such as composites of barium and zinc salts of higher fatty acids; metal salts of alkyl benzoic acids such as zinc tert-butylbenzoate; ricinoleic acid Metal soaps such as barium; organic phosphite stabilizers such as triphenyl phosphite; tin stabilizers such as dibutyltin dilaurate can be used as additives.

As the surfactant, any of an anionic surfactant, a nonionic surfactant, and a cationic surfactant can be used. Nonionic surfactants include esters of polyhydric alcohols and fatty acids such as sorbitan and glycerin, esters of polyhydric alcohols and fatty acids and dibasic acids, or compounds in which alkylene oxides such as ethylene oxide and propylene oxide are added. Alternatively, a fluorosurfactant can be used.

Lubricants include fatty acid-based lubricants such as stearic acid, fatty acid amide-based lubricants such as stearic acid amide and methylenebisstearamide, ester-based lubricants such as butyl palmitate, and organophosphate metal salt-based lubricants such as barium isodecyl phosphate. One or more lubricants selected from polyethylene wax and liquid paraffin can be used.

As the foaming agent, a microcapsule type foaming agent in which a shell made of a thermoplastic resin includes a thermally expandable material such as an aliphatic hydrocarbon such as butane or pentane, N ′, N′-dinitrosopentamethylenetetramine, N ', N'-dimethyl-N', N'-dinitrosotephthalamide, azodicarboxamide, azobisisobutyronitrile, benzenesulfonyl hydrazide, P, P'-oxybis (benzenesulfonyl hydrazide), benzene-1, Thermally decomposable foaming agents such as 3-disulfonyl hydrazide and toluenesulfonyl hydrazide can be used. However, if these foaming agents are added to the variable color coloring layer, the solar reflectance in the visible light region tends to increase, so the solar transmittance in the visible light region may be reduced. Need to be adjusted accordingly.

Examples of UV absorbers include benzophenone UV absorbers such as 2-hydroxy-4-methoxybenzophenone, benzotriazole UV absorbers such as 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, and salicylic acid ester One or more selected from ultraviolet absorbers and cyanoacrylate ultraviolet absorbers can be used.

Examples of the light stabilizer include 4- (phenylacetoxy) -2,2,6,6-tetramethylpyridine, tris- (2,2,6,6-tetramethyl-4-piperidyl) triazine-2,4,6. -Hindered amine light stabilizers such as tricarboxylates can be used.

As the antioxidant, generally used phenolic antioxidants, thiopropionic acid ester antioxidants, aliphatic sulfide antioxidants, and the like can be used.

As the filler, any inorganic and / or organic filler that has excellent heat resistance and does not cause physical or chemical changes such as melting and decomposition at the processing temperature can be used. Specific examples include inorganic fillers such as calcium carbonate, magnesium carbonate, magnesium silicate, aluminum oxide, aluminum hydroxide, magnesium hydroxide, talc, hydrotalcite, crosslinked vinyl chloride resin powder, acrylic resin Examples thereof include organic fillers such as powders and powders of crosslinked synthetic resins such as polyurethane powders.

About the solar transmittance of the variable chromatic coloring layer:
The variable color coloring layer is constituted by adding at least a specific rare earth element oxide to a synthetic resin as described above, and a reflection layer described later is laminated on the variable color coloring layer. Good color rendering properties are exhibited on the surface of the variable chromaticity colored layer side of the variable chromaticity sheet. In the present invention, the solar radiation transmittance in the visible light region of the variable chromaticity colored layer is 60% or more in order to sufficiently obtain the reflection effect of the reflective layer described later and to make the color rendering property visible well. It is desirable. When the solar radiation transmittance in the visible light region of the variable chromatic coloring layer is less than 60%, the amount of light that passes through the variable chromatic coloring layer, is reflected by the reflective layer, and passes through the variable chromatic coloring layer again is small. Also, the color rendering due to the change of the light source is difficult to see. In order to obtain the desirable solar radiation transmittance, it is desirable to consider the transparency of the synthetic resin used, the type and amount of additives, and the like.

The above-mentioned “sunlight transmittance” indicates a rate at which a wavelength in the visible light region is transmitted, and is measured in accordance with JIS-A-5759.

About the thickness of the variable chromatic coloring layer:
The thickness of the variable chromatic coloring layer is not particularly limited, and the use of the sheet of the present invention, the amount of rare earth element oxide added, the transmittance of the synthetic resin constituting the colored layer, etc. This can be determined as appropriate. The same applies to the case where the variable color sheet of the present invention is used as wallpaper. In general, the thickness of the variable color layer is preferably about 50 μm to 200 μm.

(About the reflective layer)
Next, the reflective layer in the present invention will be described. The reflective layer of the present invention is a layer that is laminated on the variable chromatic coloring layer, and is a layer that exhibits reflectivity with respect to light in the visible light range. In order to obtain a sufficiently rich color rendering in the variable color sheet of the present invention, the reflection of the reflective layer is a solar reflectance in a visible light region of 380 nm to 780 nm defined in JIS-A-5759. It is desirable that the high reflectivity is 70% or more.

  Hereinafter, the reason why the color rendering property of the rare earth element is satisfactorily exhibited by providing the reflective layer in the present invention will be described.

Generally, a part of light incident on a substance is reflected, a part is absorbed, and the rest is transmitted. The amount of reflection, absorption, and transmission of light varies depending on the additive contained in the substance, the permeability of the substance, and the like, but the higher the permeability of the substance, the greater the amount of light transmission.
Here, when a single-layer colored layer containing a rare earth element is studied, among the light in the visible light range incident on the colored layer, a wavelength having a specific absorption peak is included in the rare earth element contained in the colored layer. As it is absorbed, part of the other light is reflected and stimulates the retina of the viewer to make a specific color tone visible. When each light source having a different light wavelength distribution is irradiated, the color tone visually recognized by the viewer changes due to the balance between the wavelength absorbed by the rare earth element and other wavelengths, so-called color rendering. Sex can be demonstrated.

However, when the present inventors have studied in detail a single colored layer containing a rare earth element, the single colored layer generally has high light transmittance, in other words, low light reflectance, By allowing the rare earth element to absorb only a specific wavelength in the visible light region and reflecting the remaining wavelengths, the color tone peculiar to the rare earth element cannot be fully exhibited, and the color tone shown in various light sources It was found that the difference hardly appears (Problem 1) and the brightness is not sufficient (Problem 2). On the other hand, it was also possible to improve the color rendering by adding a large amount of rare earth elements, but it was also economically disadvantageous and not substantial (Problem 3). That is, for reasons such as the above problems 1 to 3, it has been difficult to obtain rich color rendering properties with a single colored layer containing a rare earth element.
In order to solve the above problems 1 and 2, when a white pigment such as titanium oxide is added to the colored layer so as to increase the reflectivity of the colored layer itself, the reflectance is improved and the high brightness is obtained. Although the incident light is reflected mainly on the surface area of the colored layer, the amount of incident light reaching the rare earth element present in the colored layer is reduced, and the color rendering is rather poor.

  Thus, as a result of diligent efforts, the present inventors have found that, by effectively utilizing light transmitted through a colored layer containing a rare earth element, it is possible to exhibit good color rendering properties that have not been obtained conventionally. . Specifically, by laminating a reflective layer showing reflectivity with respect to light in the visible light region on a colored layer containing a rare earth element, the light transmitted from the colored layer side was transmitted through the colored layer. Light can be reflected by the reflective layer. Then, since the reflected light passes through the colored layer again from the direction substantially opposite to the incident light, the amount of light absorbed by the rare earth element increases. As a result, the specific color tone shown by the rare earth element is clearly shown, and the change in color tone when the light source is changed, that is, the color rendering property can also be shown well.

The reflective layer in the present invention is not particularly limited as long as it is a layer that can be favorably reflected in the visible light range. For example, a white sheet, a metallic gloss layer such as aluminum, or a sheet having a mirror finish is used. Etc. can be appropriately selected and used.
As the white sheet, for example, a white synthetic resin sheet can be used. The white synthetic resin sheet is formed by using any of the resins listed as the synthetic resin used to form the above-described variable color coloring layer and adding a white pigment or metal powder to form a sheet. Can be easily obtained. As the white pigment, a preferable white color can be obtained by mixing a relatively large amount of an inorganic compound such as titanium oxide or barium sulfate. Furthermore, it is possible to increase the reflectance by mixing fillers such as solid glass beads, hollow glass balloons, and shirasu balloons.

  The synthetic resin that constitutes the reflective layer may be the same as the synthetic resin that constitutes the variable color layer or may be a different type.

Furthermore, in addition to adding a white pigment or the like to the synthetic resin as described above, the above-mentioned plasticizer, stabilizer, surfactant, lubricant, foaming agent, ultraviolet absorber, light stabilizer, antioxidant, filling Various additives such as a colorant and a colorant can be added in the same manner by one or a combination of two or more.
For example, according to an embodiment in which a foaming agent is added to a synthetic resin and a reflective layer that is a foamed resin sheet is employed, the reflectivity of the reflective layer can be further enhanced by the cell structure constituting the foamed resin sheet. In addition, there is an effect that impact absorbability can be imparted. Further, by foaming the synthetic resin constituting the reflective layer, it is possible to show uneven shadows on the surface of the reflective layer, and the reflective layer portion exposed to the outer surface of the sheet (that is, the reflective layer on which the colored layer is not laminated) It is possible to improve the decorativeness of the sheet by the shading of the unevenness in the portion). Alternatively, by laminating the variable chromatic coloring layer on the foaming reflective layer, it is possible to impart a shadow derived from the unevenness of the reflective layer surface to the variable chromatic coloring layer surface. Therefore, by bubbling the reflective layer, it is possible to show a decorative effect due to the shading of irregularities even on the surface of the variable color pigmented layer.

(About support substrate)
As described above, the variable color sheet of the present invention has a basic structure of a two-layer structure of a variable color coloring layer containing an oxide of a rare earth element and a reflective layer laminated thereon. A support base material may be laminated. As the supporting substrate, various paper substrates or nonwoven fabric substrates can be used as appropriate. In addition, when the said support base material is provided with reflectivity, this support base material can also be utilized as a combined member of a reflective layer and a support base material.

(About surface protective layer)
Further, a protective layer may be further laminated on the variable color coloring layer side in the present invention. The protective layer is desirably transparent to such an extent that the color rendering properties exhibited by the variable color coloring layer are not disturbed, but from the viewpoint of giving a subtle nuance to the color tone, for example, it may be transparent or partially colored. Good. The surface protective layer can be generally composed of a light transmissive curable resin, but is not limited thereto.

(About layer structure)
The sheet of the present invention composed of the variable color coloring layer and the reflective layer, or further a support substrate, may have a simple laminated structure in which each layer is substantially flat, or an arbitrary layer is printed and formed. For example, it can be formed as a pattern layer. For example, as shown in FIG. 1A, the variable color sheet 1 of the present invention can be configured as a two-layer structure of a variable color coloring layer 2 and a reflective layer 3, or FIG. ), The support base material 4 may be further laminated on the reflective layer 3 side as the variable color sheet 1 ′ of the present invention. Although not shown, a surface protective layer may be provided on the surface of the variable color coloring layer 2 in the variable color sheet 1 or 1 ′. As another example, as shown in FIG. 2A, as the variable chromaticity sheet 11 of the present invention, a discontinuous variable chromaticity coloring layer 2 provided in an arbitrary pattern on the reflective layer 3 is provided. Alternatively, as shown in the variable color sheet 11 ′ shown in FIG. 2 (B), a discontinuous reflective layer 3 having an arbitrary pattern is formed on one surface of the support base 4 for reflection. The variable color coloring layer 2 may be provided on substantially the entire surface of the support base 4 so as to cover the layer 3. As another embodiment, a discontinuous reflective layer 3 having an arbitrary pattern is formed on the base sheet 4 as in the variable color sheet 11 ″ shown in FIG. A variable color coloring layer 2a that is the same design and is laminated on the upper surface of the reflective layer 3 or a variable color coloring layer 2b that is different from the reflective layer 3 and is laminated to cover the reflective layer 3; A surface protective layer 5 may be provided on substantially the entire surface of the support base 4 so as to cover the reflective layer 3 and the variable color coloring layers 2a and 2b. In addition, the surface protective layer 5 in the variable color sheet 11 ″ is arbitrary, and the surface protective layer 5 may be omitted.

  The pattern of the variable chromatic coloring layer 2 or the reflective layer 3 shown in FIG. 2 means a pattern other than that formed as a substantially flat layer provided continuously, for example, any figure, character, stripe, It may be an arbitrary line pattern such as on a lattice.

(About variable color wall decoration)
The variable color sheet of the present invention can be used as an interior decoration material, and in particular, can be used as wallpaper. The variable color wall surface decoration material of the present invention using the variable color sheet is scheduled to be used so that the reflective layer is positioned on the wall surface side and the variable color coloring layer is positioned on the outer surface of the reflective layer. In general, a structure in which a supporting base material such as a backing paper is provided, a reflective layer is provided on one surface of the supporting base material, and a variable color coloring layer is provided on the surface of the reflective layer is desirable. Such a variable color wall surface decoration material is generally used such that a support base material and a wall surface are bonded to a wall surface made of gypsum board, wood or the like using an appropriate adhesive.

Hereinafter, the variable color wall surface decoration material of the present invention will be described in more detail in accordance with a widely used method for producing vinyl chloride wallpaper. However, the present invention is not limited to the following, and can be produced with reference to various conventionally known methods for producing wallpaper.

When producing a vinyl wallpaper, a paste-like polyvinyl chloride composition for forming a reflective layer having reflectivity for light in the visible light region on a support substrate such as a paper substrate or a nonwoven fabric is used as a knife coater. , Coating by means of a comma coater, etc., heat-gelating it to form a vinyl chloride resin layer as a reflective layer, and further forming a paste-like polymer on the surface to form a variable color coloring layer exhibiting color rendering properties Coating a composition prepared by adding an oxide of a specific rare earth element to a vinyl chloride resin by the same method as the method for forming a reflective layer, or by means such as a rotary screen printing method, and heat gelling. To form a variable color coloring layer, and if necessary, laminate a transparent synthetic resin solution layer on the surface or embossing it to make the surface uneven It can be prepared by or to emphasize.
The reflective layer and the variable chromatic coloring layer may be a uniform layer or a partial layer. If at least a part of the variable chromatic coloring layer is provided on the reflective layer, the variable color The effect of the present invention can be selectively produced in the portion where the colored layer and the reflective layer are laminated.

Further, in the same method for producing a polyvinyl chloride wall material, it is also possible to add a rare earth metal oxide exhibiting color rendering properties to a solution of a transparent synthetic resin laminated on the outermost surface of a polyvinyl chloride resin.

As the synthetic resin solution used in this case, for example, a polyurethane resin, an acrylic resin, an epoxy resin, a polyester resin, or the like is used. As the synthetic resin solution, the synthetic resin is dissolved in various organic solvents. In addition to those, a synthetic resin dispersion (so-called emulsion) in which a synthetic resin is dispersed in a liquid may be used.
Furthermore, there is no problem in adding various additives as necessary.

(Evaluation of the present invention)
As described above, the variable color sheet or the variable color wall surface decoration material of the present invention contains a specific rare earth element in a synthetic resin and can exhibit good color rendering properties. The effect of the sheet of the present invention, that is, whether or not the color rendering property is sufficiently exhibited can be evaluated by measuring L * value, a * value and b * value with a color difference meter using various light sources. it can.

Specifically, in Konica Minolta spectrophotometer CM-3600d, D65 light source (sunlight measurement light source), F10 light source (fluorescent lamp measurement light source: three-wavelength daylight white), A light source (incandescent light bulb) Color rendering properties can be evaluated by using three types of light sources (measurement light sources), performing color measurement under each of the light sources, and obtaining a difference in measured values due to the difference in the light sources. Here, the L * value indicates the brightness of the color, and the a * value and the b * value indicate the chromaticity. Therefore, the change in the a * value and / or b * value when the light source is changed reflects the change in the color tone, and the color rendering properties increase as the change rate (that is, the difference in the measured value expressed in absolute value) increases. It means high.

That is, when the a * value and the b * value are measured using a plurality of light sources, and the difference between the a * value and the b * value under different light sources is calculated, this difference (that is, the rate of change in chromaticity depending on the type of light source). ) Means higher color rendering properties. This difference does not need to be large in comparison among all the light sources used, and at least a difference in a * value and / or b * value between the D65 light source (sunlight measurement light source) and the F10 light source or A light source. Can be evaluated as having good color rendering properties. According to the above, it is possible to evaluate whether it is possible to show a significantly different color tone between chromaticity under sunlight during daytime and chromaticity under a light source commonly used as an artificial light at night or the like. it can.

The above-mentioned chromaticity difference that can be evaluated as having good color rendering properties is required to be 2 or more in order to ensure that the color rendering properties are visually recognized. In order to be recognized as sex, it is more desirable that the difference is 3.5 or more.
In particular, from the viewpoint of use as a wall decoration material, in addition to good color rendering properties, it is desired that the lightness is high both in the daytime and at night, so in addition to having the above-mentioned good degree of difference. It is desirable that the brightness is sufficiently high. The degree to which the wall surface feels bright in the room is 60 or more, more preferably 70 or more, and even more preferably 75 or more in the lightness. Even if the above-described chromaticity difference is 2 or more, if the lightness is less than 60, the color rendering property is visually recognized, but the room may be felt dark or stuffy.

In addition, as a method of measuring the solar reflectance in the visible light region of the reflective layer, an intensity function taking into account the wavelength distribution of actual sunlight as defined in JIS-A5759 is added to the actual spectral reflectance measured value. Can be calculated.
Specifically, the spectral reflectance in the visible light region of 380 nm to 780 nm was measured with an integrating sphere using a self-recording spectrophotometer V-570 manufactured by JASCO Corporation, and the weight value specified in Table 3 of JIS-A5759 It is a value calculated by adding a coefficient.
In the case where the variable chromatic coloring layer is provided not on the entire surface but partially on the surface of the reflective layer (for example, the mode of FIG. 2A), at least the variable chromatic coloring layer is laminated. The reflective layer in the part can reflect light in the visible light region satisfactorily. Desirably, the solar radiation reflectance in the visible light region of the reflective layer is 70% or more, and the variable color coloring layer is not necessarily provided on the upper surface. The above-described reflectivity is not required even in a portion that does not have the.

Examples of the variable color sheet of the present invention will be described below, but the present invention is not limited to the following examples.

(Reflective layer composition paste)
Various additives are added to 100 parts by weight of polyvinyl chloride resin (PX-QHPN, manufactured by Shin Daiichi Vinyl Co., Ltd.), and vinyl chloride resin pastes B1 to B4 (hereinafter referred to as “vinyl chloride” for constituting the reflective layer). The “resin paste” was omitted, and “B1” or the like may be simply described.) Was prepared. Table 1 shows the types and amounts of additives added in B1 to B4. The numerical values in the table are all expressed in parts by weight except the solar reflectance.

(Paste for variable color coloring layer composition)
Various additives are added to 100 parts by weight of a polyvinyl chloride resin (PX-QHPN, manufactured by Shin Daiichi Vinyl Co., Ltd.) to form vinyl chloride resin pastes A1 to A9 (hereinafter, The “vinyl chloride resin paste” was omitted, and “A1” or the like may be simply described. Table 2 shows the types and amounts of the additives added in A1 to A9. All numerical values in the table are shown in parts by weight.

(Examples 1-8)
Paper-made paper base material (CP-65 manufactured by Chuetsu Pulp Co., Ltd.) (weight per unit area: 65 g / m ² ) was used as a supporting base material, and the vinyl chloride resin paste B1 shown in Table 1 was formed on the entire surface of the paper base material. Was coated to a thickness of 0.15 mm, and heated at 140 ° C. for 1 minute to gel to form a reflective layer, and on the reflective layer, a vinyl chloride resin paste A2 shown in Table 2 was used. After coating the variable color coloring layer in stripes by screen printing to a thickness of 0.1 mm, the heat treatment is performed at 200 ° C. for 40 seconds to foam the reflective layer, thereby producing a variable color sheet. Example 1 was adopted.
Further, a variable color sheet was prepared in the same manner as in Example 1 except that the vinyl chloride resin paste A4 was used instead of the vinyl chloride resin paste A2. In addition, in the same manner as in Example 1, Example 3 was used using B1 and A5, Example 4 was used using B1 and A3, Example 5 was used using B1 and A1, and Example 2 was used using B2 and A2. 6, Example 7 was prepared using B2 and A4, and Example 8 was prepared using B1 and A9.

(Comparative Examples 1-7)
A variable chromaticity sheet was prepared in the same manner as in Example 1 except that the vinyl chloride resin paste A8 was used instead of the vinyl chloride resin paste A2, and used as Comparative Example 1. Further, in the same manner as in Example 1, Comparative Example 2 was compared using B3 and A2, Comparative Example 3 was compared using B3 and A4, Comparative Example 4 was compared using B4 and A2, and Comparative Example 4 was compared using B4 and A4. In Example 5, Comparative Example 6 was prepared using B1 and A6, and Comparative Example 7 was prepared using B1 and A7.

(Reference Examples 1 and 2)
Without using the vinyl chloride resin paste B, it was coated on the paper substrate directly in the same stripe shape as in the example using the vinyl chloride resin paste A3 to a thickness of 0.1 mm by screen printing, at 200 ° C. A sheet was prepared by heat treatment for 40 seconds to obtain Reference Example 1. Further, a sheet was prepared as Reference Example 2 in the same manner as in Reference Example 1 except that A1 was used instead of the vinyl chloride resin paste A3.

(Evaluation 1)
About Examples 1-8 which are the variable chromaticity sheet | seats of this invention, Comparative Examples 1-7 with respect to this, and the reference example 1, the chromaticity a * value and b * value in a some light source were measured with the following method, and color rendering Sex was evaluated. Further, the lightness L * value on the colored layer side surface of each sheet was also measured. Note that the measurement was performed at a portion where the variable chromatic coloring layer and the reflective layer were laminated.

The chromaticity and lightness are measured using a spectrophotometer CM-3600d manufactured by Konica Minolta, using a D65 light source (sunlight measurement light source) and an F10 light source (fluorescent lamp measurement light source: three-wavelength type) at an angle of 2 °. L * value, a * value, and b * value with A light source (light source for measuring incandescent bulb) were measured. The measurement results are shown in Table 3 for Examples and Table 4 for Comparative Examples and Reference Examples.

In order to evaluate the color rendering properties from the values obtained in the above measurement, for each of the a * value and the b * value, F-10 (3-wavelength fluorescent light source) or D65 (light source for measuring sunlight) is used as a reference. The difference from A (incandescent light source) was calculated as an absolute value as | D65-F10 | and | D65-A |. About a calculation result, it shows to Table 3-2 about an Example and Table 4-2 about a comparative example and a reference example.

  From the above evaluation 1, all of Examples 1 to 8 show a value of 2 or more in at least one of | D65-F10 | or | D65-A | in the a * value and / or the b * value. confirmed. This is because the chromaticity shown when the sun is used as the light source and the chromaticity shown when the fluorescent lamp or incandescent light bulb, which is widely used as a room light, is used as the light source, have a visually different tone. It was confirmed that all of Examples 1 to 8 had good color rendering properties. Further, in Examples 1 to 8, the lightness exceeds 75 under any light source used in this evaluation, and when used as a wall decoration material, the wall surface can be felt as bright as desired. It was confirmed to be a thing.

  On the other hand, in Comparative Examples 1 to 7, the absolute values | D65-F10 | and | D65-A | obtained as differences in chromaticity are both less than 2, and the color rendering property is poor. It was confirmed that there was no change in color tone under the incandescent bulb.

  In Reference Example 1, numerical values of 2 or more were shown in absolute values | D65-F10 | and | D65-A | obtained as differences in chromaticity. However, the difference in chromaticity of Reference Example 1 prepared by adding 10 parts by weight of holmium oxide is the same as that of Example 5 including the variable chromatic coloring layer prepared by adding 3 parts by weight of holmium oxide. Less than or equal to the difference. The brightness of Reference Example 1 was less than 60 under any of the light sources used in this evaluation. Accordingly, it was suggested that the present invention including the reflective layer exhibits a sufficient color rendering property and can ensure a sufficient brightness even if the amount of the rare earth element added is small.

(Evaluation 2)
In order to evaluate the reflectance of the sheet in the presence or absence of the reflective layer, the reflectance of the layer side to which the rare earth element was added was recorded using Example 4, Example 5, Reference Example 1 and Reference Example 2. Measured at The measurement conditions were in accordance with JIS-A5759, and the spectral reflectance in the visible light region of 380 nm to 780 nm was measured with an integrating sphere with a self-recording spectrophotometer V-570 manufactured by JASCO Corporation. The value calculated taking into account the specified weight coefficient was taken as the reflectance at that wavelength. The results are shown in FIG. 3, Example 4 is shown as a square symbol (10 phr Ho ₂ O ₃ / white), Example 5 is shown as a diamond symbol (3 phr Ho ₂ O ₃ / white), and Reference Example 1 is a triangular symbol ( 10 phr Ho ₂ O ₃ single layer), and Reference Example 2 was shown as a round symbol (3 phr Ho ₂ O ₃ single layer).

From the result of Evaluation 2, it was found that Example 4 and Example 5 including the reflective layer had significantly higher reflectance than Reference Example 1 and Reference Example 2. Further, in all the samples, absorption peaks of specific wavelengths peculiar to holmium oxide were confirmed in the vicinity of 460 nm, 540 nm, and 650 nm, but the amounts of addition of holmium oxide were the same as in Example 4, Reference Example 1, and Example 5. When the absorption peak was compared with Example 2, it turned out that all of Examples show a sharper absorption peak.

As described above, from the result of evaluation 2, it is possible to increase the reflectance of the surface of the colored layer by laminating the reflective layer on the colored layer containing the rare earth element, and as a result, high brightness is shown. Even when the addition amount of the rare earth element is the same, each absorption peak is remarkably increased due to the presence of the reflective layer, suggesting that the color rendering properties are significantly improved.

1A and 1B are cross-sectional views showing an embodiment of the variable color sheet of the present invention. 2A to 2C are cross-sectional views showing an embodiment of the variable color sheet of the present invention. It is a graph which shows the reflectance of Example 4, Example 5, Reference Example 1, and Reference Example 2. FIG.

Explanation of symbols

1 ′, 11, 11 ′, 11 ″ Variable color sheet 2 Variable color layer 3 Reflective layer 4 Support base material 5 Protective layer

Claims (3)

The base material, the reflective layer, and the variable chromatic coloring layer are laminated in this order,
On one surface of the variable color coloring layer containing at least one oxide of rare earth elements selected from holmium (Ho), neodymium (Nd), and erbium (Er) in the synthetic resin, A reflective layer having reflectivity in the visible light region is laminated,
The solar reflectance in the visible light region of the reflective layer is 70% or more,
The thickness of the variable chromatic coloring layer is 50 to 200 μm,
A variable chromaticity sheet characterized in that the hue changes depending on the light source . The variable color sheet according to claim 1, wherein the variable color coloring layer has a solar transmittance of 60% or more in a visible light region. 3. The variable color sheet according to claim 1, wherein the reflective layer is located on a wall member side, and the variable color colored layer is located outside the reflective layer. A variable color wall surface decoration material characterized in that

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