JP2018192741A - Laminated decorative structure - Google Patents

Abstract

To provide a laminated decorative structure forming an ornamental design, capable of recognizing a specific color when observing the ornamental design from a front, and capable of heightening ornamental design properties by varying colors when observing from an oblique angle.SOLUTION: The laminated decorative structure includes: a layer A; a layer B on one surface thereof; and a layer C on the other surface, where the layer A has a first reflection wave length band in a visible light region concerning a vertically incident light and a second reflection wave length band in a visible light region concerning an obliquely incident light, the first reflection wave length band is a reflection wave length band different from the second reflection wave length band, the layer B is a hiding layer, and the layer C covers a part of layer A and does not cover a part.SELECTED DRAWING: None

Description

  The present invention relates to a laminated decorative structure. Specifically, a laminated decorative structure rich in design using a layer having a reflection wavelength band in the visible light region for vertically incident light and a layer having a reflection wavelength band different from that in the visible light region for oblique incident light. About.

  The optical interference film is configured to selectively reflect or transmit light having a specific wavelength due to structural optical interference between layers by alternately laminating layers having a low refractive index and layers having a high refractive index. Such an optical interference film is obtained by setting the wavelength of light that is selectively reflected or transmitted in the visible light region, thereby obtaining a film having a pearly luster that looks superior in design, such as iridescent, by structural color development. be able to.

  Patent Document 1 discloses an optical interference film that uses selective reflection of visible light and is visually colorless and transparent when an object is viewed from the front, and exhibits a color when the object is viewed from an oblique angle. It is disclosed. Further, in Patent Document 2, although the base material does not have the feature, a reflective layer that enables selective reflection of visible light is provided on the base material, so that when a person visually recognizes an object, iridescent color The structure which provides the designability of is disclosed.

  On the other hand, articles that can be visually recognized by human eyes, such as building materials, electronics, and mobility such as automobiles, have a design value that is one value in purchasing. Therefore, technologies that can be given designs have been increasingly proposed in recent years. For example, Patent Document 3 discloses a technique for giving a beautiful appearance to a base material by performing surface decoration using a decorative structure. Among them, particularly in the field of mobility such as automobiles, it is desired to enhance visibility from the viewpoint of enhancing safety.

JP-T-2006-512619 JP 2011-255558 A JP 2013-241528 A JP2015-118160A

  An object of the present invention is to form a design, and when such a design is viewed from the front, a specific color can be visually recognized, and when the color is viewed at an oblique angle, the design can be improved by changing the color. The object is to provide a decorative structure.

  As a result of intensive studies to achieve such an object, the inventors have arranged a concealing layer on one surface of a film having a property of reflecting visible light at the front and oblique angles, and a part of the other surface. By arranging a layer (sometimes referred to as a non-hidden layer) that covers a part of the non-hidden layer, the coated part of the non-hidden layer and the non-hidden layer are covered. The design is formed by the parts that are not present, and the formed design expresses a desired color when viewed from the front, and expresses a color different from the color when viewed from an oblique angle, and is a color due to a change in the viewing angle. From this change, it was found that the effect of enhancing the visibility can be imparted, and the present invention has been completed.

That is, this invention comprises the following structures.
1. A layered decorative structure having layer A and layer B on one side and layer C on the other side,
The layer A has a first reflection wavelength band in the visible light region for vertically incident light, a second reflection wavelength band in the visible light region for oblique incident light, and the first reflection wavelength band and the second reflection wavelength band. It is a reflection wavelength band different from the reflection wavelength band,
Layer B is a concealing layer,
The layer C covers a part of the layer A and does not cover a part thereof.
Laminated decorative structure.
2. The laminated decorative structure according to the above 1, wherein the difference between the first reflection wavelength band and the second reflection wavelength band is 10 nm or more.
3. The laminated decorative structure according to 1 or 2 above, wherein the median value of the first reflection wavelength band is 500 to 750 nm and the median value of the second reflection wavelength band is 400 to 650 nm.
4). The layer A is a birefringent layer A1 mainly containing an aromatic polyester mainly composed of ethylene-2,6-naphthalenedicarboxylate, and an isotropic layer A2 mainly containing an amorphous copolyester. The laminated decorative structure according to any one of 1 to 3 above, wherein the laminated film is formed by laminating films alternately laminated, and the laminated film transmits blue light.
5). The laminated decorative structure according to any one of 1 to 4, wherein the layer B has a color that can be visually recognized as white or black.
6). The laminated decorative structure according to any one of 1 to 5, wherein an area ratio of a portion of the layer C that does not cover the layer A is 10% or more.
7). The laminated decorative structure according to any one of 1 to 6, which is for a moving body.

  According to the present invention, it is possible to visually recognize a specific color when a design is formed and the design is viewed from the front, and to improve the design by changing the color when viewed at an oblique angle. A decorative structure can be provided.

  Hereinafter, the present invention will be described in detail.

[Laminated decorative structure]
The laminated decorative structure of the present invention has a layer A and a layer B on one surface thereof, the surface is covered with the layer B, and has a layer C on the other surface. Has a layer structure of at least three or more layers, which are partially covered by the layer C and not partially covered. Such a layered decorative structure is one in which the side of the layer C becomes the viewer side and the design is achieved. The layer B is a concealing layer, and for example, when the laminated decorative structure of the present invention is used by being attached to a base material, the color of the base material can be concealed.

[Layer A]
(Reflection characteristics of layer A)
The layer A in the present invention is a reflection unit having a first reflection wavelength band in the visible light region for vertically incident light and a second reflection wavelength band in the visible light region for oblique incident light. The first reflection wavelength band and the second reflection wavelength band are different reflection wavelength bands.

  In the present invention, unless otherwise specified, the “visible light region” refers to a wavelength range of 400 to 800 nm.

  Further, the “reflection wavelength band” refers to a region between the intersections of the short wavelength side intersection and the long wavelength side intersection of the 30% reflectance in the reflection band having a case where the reflectance is 50% or more.

  “Vertical incident light” refers to light that is incident on the surface of the layer A from the normal direction, and in the spectrum of light that is reflected in the normal direction to the surface of the layer A, the visible light region. The first reflection wavelength band.

  The “oblique incident light” refers to light that is incident on the surface of the layer A at an arbitrary incident angle other than the normal direction, and the light is incident on the surface of the layer A with the arbitrary incident angle. In the spectrum of light reflected at the same emission angle, the second reflection wavelength band is provided in the visible light region. The incident angle is preferably 80 degrees or less, more preferably 75 degrees or less, and further preferably 65 degrees or less. This is because if the incident angle is too large, it is difficult to change the color even if the angle is set. If the incident angle is small, the color changes with a slight change in the angle, which may be desired. However, if the incident angle is too small, after the color has changed due to a slight change in the angle, it tends to be difficult to change the color even if the angle is changed, so the lower limit of the incident angle is preferably It is 10 degrees or more, more preferably 25 degrees or more, and further preferably 45 degrees or more.

  A plurality of reflection wavelength bands may be provided, but the first reflection wavelength band and the second reflection wavelength band are selected as the reflection wavelength band having the maximum average reflectance of the reflection wavelength band.

  As described above, the layer A in the present invention has the first reflection wavelength band and the second reflection wavelength band, and these are different reflection wavelength bands. Here, “different reflection wavelength bands” means that the medians of the reflection wavelength bands do not match, and preferably means that there is a difference of 10 nm or more. Such a difference is more preferably 30 nm or more, further preferably 50 nm or more, and particularly preferably 80 nm or more. The greater the difference, the greater the change in color when the angle is added, which is preferable as design. Here, the “median value” refers to the median value of the wavelength in the wavelength region where the reflectance is 50% or more in the reflection wavelength band.

  The median value of the first reflection wavelength band is preferably in the range of 500 to 750 nm. The second reflection wavelength band preferably has a median value in the range of 400 to 650 nm. By doing in this way, it will change a preferable color and is preferable as designability. From this viewpoint, the median value of the first reflection wavelength region is more preferably in the range of 520 to 710 nm, and further preferably in the range of 540 to 670 nm. The median value of the second reflection wavelength region is more preferably in the range of 420 to 610 nm, and still more preferably in the range of 440 to 570 nm.

  The bandwidths of the first reflection wavelength band and the second reflection wavelength band are preferably individually 250 nm or less. This makes it easy to recognize a specific color in each of the case of normal incidence light and oblique incidence light. If the bandwidth is too wide, light of many wavelengths is mixed and approaches white light. Therefore, if one bandwidth is moderately narrow and it is easy to recognize a specific color, even if the other bandwidth is wide and close to white light, it may be preferable as a design if it is recognized as a color change. . From the viewpoint of easily recognizing a specific color, the bandwidth is more preferably 220 nm or less, and further preferably 200 nm or less. An embodiment in which both the first reflection wavelength band and the second reflection wavelength band satisfy these conditions can be exemplified as a preferable aspect. In that case, when an angle is applied, a change from a specific color to a specific color occurs, and as a design property It may be preferable. From the viewpoint of approaching white light, the bandwidth may exceed 250 nm, for example, 350 nm or less and 300 nm or less. Here, “bandwidth” refers to the distance between the short wavelength side intersection and the long wavelength side intersection in the above-described reflection wavelength band.

  The average reflectance of the first reflection wavelength band and the second reflection wavelength band is preferably individually 60% or more, more preferably 70% or more, still more preferably 90% or more, and particularly preferably 95% or more. is there. Thereby, it becomes easy to visually recognize the color. If the reflectance is too low, the color of the reflected light is difficult to be visually recognized. It is preferable that both the first reflection wavelength band and the second reflection wavelength band satisfy these, and it is easy to recognize a change in color, which is preferable as a design property. The “average reflectance” in the reflection wavelength band refers to an average reflectance in a wavelength region where the reflectance is 50% or more in the reflection wavelength band.

  There are several methods for providing such a specific reflection characteristic in visible light, and there is no particular limitation in the present application. Conventionally known techniques can be employed, but polymer layers A1 and A2 (hereinafter simply referred to as “layer A1”, respectively). , “Layer A2”) are alternately stacked, and a method of providing the above-described reflection characteristics by using a light interference effect due to a difference in refractive index between these layers is preferable. This method can be referred to the matters described in Patent Document 4. In this method, the polymer material, the polymer laminating method, and the stretching method can be arbitrarily adopted in order to provide desired reflection characteristics, but the following method is exemplified as a preferable method.

(Layer A polymer)
The layer A1 in the present invention is preferably a polyester, more preferably an aromatic polyester, and further preferably an aromatic polyester having ethylene naphthalene dicarboxylate units as main repeating units. The ethylene naphthalene dicarboxylate unit is preferably an ethylene-2,6-naphthalene dicarboxylate unit. The term “main” as used herein means that it accounts for 80 mol% or more, preferably 90 mol% or more, more preferably 95 mol% or more, based on all repeating units of the aromatic polyester in the layer A1. Particularly preferred is a homopolyester containing no copolymerization component. When the ethylene naphthalene dicarboxylate unit is less than 80 mol%, it tends to be difficult to impart a sufficient refractive index difference with the layer A2 described later, and it is difficult to develop sufficient reflection characteristics. It is in. From this viewpoint, the polyester of the layer A1 is preferably crystalline. In the present invention, crystallinity means that the crystallization enthalpy is 2 J / g or more in DSC measurement, and amorphous means that it is less than 2 J / g.

  As the copolymerization component used in the aromatic polyester, conventionally known ones can be used. For example, aromatic carboxylic acids such as isophthalic acid, terephthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, and biphenyldicarboxylic acid (however, the main repeating components) The same as the unit is excluded.); Aliphatic dicarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, etc .; acid components such as alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, diethylene glycol, Aliphatic diols such as propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol; alicyclic diols such as 1,4-cyclohexanedimethanol, polyethylene glycol , Polytetrame It can be exemplified glycol components such as glycol. Of these, isophthalic acid, terephthalic acid, neopentyl glycol, 1,4-cyclohexanedimethanol and diethylene glycol are preferable, and isophthalic acid and terephthalic acid are particularly preferable. These copolymer components may be used alone or in combination of two or more components.

  The intrinsic viscosity (orthochlorophenol, measured at 35 ° C.) of the polyester constituting the layer A1 is preferably 0.40 to 0.80 dl / g, more preferably 0.45 to 0.75 dl / g. If the intrinsic viscosity is within such a range, the film forming property when forming a film having a multilayer laminated structure with a second layer described later is good.

  The layer A1 in the present invention may contain a small amount of other polymers and additives as long as the object of the present invention is not impaired. For example, lubricants such as inert particles, colorants such as pigments and dyes, Examples thereof include additives such as an agent, a flame retardant, a foaming agent, and an ultraviolet absorber.

  The layer A2 in the present invention is preferably made of polyester. Such polyester may be crystalline or non-crystalline, but when crystalline polyester is used, depending on the processing conditions during film formation, it is easy to crystallize by heating during post-processing and is transparent. May be accompanied by deterioration of the properties and reflection characteristics. On the other hand, it is preferable to use an amorphous polyester as the polyester of the layer A2, because it becomes easy to maintain the high transparency and reflectance of the initial film even after heating during post-processing.

  A preferable amorphous polyester in the present invention is preferably a copolyester, more preferably copolyethylene terephthalate. More specifically, a polyester containing an ethylene terephthalate component in an amount of 50 mol% or more and 80 mol% or less based on all repeating units is preferably exemplified, and more preferably an ethylene terephthalate component is 55 mol% or more and 75 mol% or less. is there. That is, it is a copolymerized polyethylene terephthalate in which the copolymerization component is preferably 20 to 50 mol%, more preferably 25 to 45 mol%. In order to make it amorphous, it is preferable to adjust the amount of copolymerization that exhibits amorphousness in accordance with the type of copolymerization component to be used, such as copolymerization of copolymerized polyethylene terephthalate. When the component is isophthalic acid or naphthalenedicarboxylic acid, for example, it may be about 30 mol% or more.

  When the copolymerization amount of the copolyester of the layer A2 is less than the lower limit, it tends to be crystallized and oriented during film formation, making it difficult for the refractive index difference to occur between the layer A1 and the reflective characteristics to be easily reduced. It is in. In addition, the haze tends to increase due to crystallization during film formation. On the other hand, if the amount of copolymerization exceeds the upper limit, heat resistance and film-forming properties during film formation (particularly during extrusion) are likely to be reduced, and the copolymer component is a component that imparts high refractive index properties. The refractive index difference from the layer A1 tends to be small due to the increase in the refractive index. When the copolymerization amount is within the above range, it is easy to secure a sufficient difference in refractive index from the layer A1 while maintaining good heat resistance and film-forming properties, and easily impart sufficient visible light reflection performance. Become.

  When crystalline polyester is used as the layer A2, the layer A2 is melted at the time of film formation by setting the heat setting temperature at the time of film formation to not less than the melting point of the layer A2 and not more than the melting point of the layer A1, for example. Crystallization can be suppressed, and the initial haze can be reduced. Further, by melting the layer A2 during film formation and suppressing the crystal and orientation, a difference in refractive index between the layer A1 and the layer A1 can be easily obtained. When the difference in refractive index is increased, high visible light reflection performance can be imparted. However, even if it melts and suppresses crystallization and orientation in this way, the layer A2 has crystallinity due to the nature of the crystalline polyester. As a result, an increase in haze and a decrease in reflectance may occur. For this reason, amorphous polyester is preferred.

  As copolymerization components preferably used for the polyester constituting the layer A2, aromatic dicarboxylic acids such as isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, adipic acid, azelaic acid, sebacic acid, decane Aliphatic dicarboxylic acids such as dicarboxylic acids, acid components such as alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, aliphatic diols such as butanediol and hexanediol, alicyclic diols such as cyclohexanedimethanol, and glycol components such as spiroglycol. Can be mentioned. Of these, isophthalic acid, 2,6-naphthalenedicarboxylic acid, cyclohexanedimethanol, and spiroglycol are preferable. When a copolymerization component other than these is included, the copolymerization amount is 10 based on the total acid component or the total glycol component. It is preferable that it is below mol%. In particular, 1,4-cyclohexanedimethanol is preferred as a copolymer component of an amorphous polyester containing an ethylene terephthalate component from the viewpoint of a low refractive index and a small decrease in molecular weight during extrusion.

  As the polyester constituting the layer A2, a copolymerized polyester having a glass transition temperature of less than 90 ° C., more preferably a copolymerized polyethylene terephthalate having a glass transition temperature of less than 90 ° C. can be used. When the glass transition temperature is such that the polyester of the layer A1 is stretched under stretching conditions such that the polyester of the layer A1 is oriented, the orientation of the polyester of the layer A2 is difficult to proceed because of the high stretching temperature. It becomes easy to make a refractive index difference between them. The glass transition temperature of polyester here is calculated | required by the DSC measuring method mentioned later using a polymer sample.

  The intrinsic viscosity (orthochlorophenol, measured at 35 ° C.) of the polyester constituting the layer A2 is preferably 0.4 to 1.0 dl / g, more preferably 0.45 to 0.95 dl / g, still more preferably. Is in the range of 0.5-0.90 dl / g. When the intrinsic viscosity is not within such a range, the difference from the intrinsic viscosity of the polyester constituting the layer A1 may become large. The film forming property may be deteriorated.

  When two or more kinds of polyesters are melt-mixed in an extruder and are obtained by transesterification, the intrinsic viscosity of each polyester may be in the above range.

  The layer A2 in the present invention may contain a small amount of additives within a range that does not impair the object of the present invention. Examples of such additives include lubricants such as inert particles, and colorants such as pigments and dyes. And additives such as stabilizers, flame retardants and foaming agents. Examples of the lubricant particles include inorganic particles such as silica, alumina, titanium oxide, calcium carbonate and kaolin, precipitated particles of catalyst residues, and organic particles such as silicone, polystyrene cross-linked bodies and acrylic cross-linked bodies.

  The polyester of the layers A1 and A2 in the present invention can be produced by applying a known method. For example, it can be produced by a method in which an acid component, a glycol component, and a copolymer component as main components are esterified and then a reaction product obtained is subjected to a polycondensation reaction to obtain a polyester. Alternatively, these raw material monomer derivatives may be transesterified, and then the resulting reaction product may be subjected to a polycondensation reaction to obtain a polyester. Further, it may be a method obtained by melt-kneading in an extruder using two or more kinds of polyesters to cause a transesterification reaction (redistribution reaction).

(Laminated structure of layer A)
The layer A used in the laminated decorative structure of the present invention is preferably one in which the above-described layer A1 and layer A2 are alternately laminated. However, since the reflectance is increased by increasing the number of laminated layers, a desired layer A is used. A suitable number of layers may be selected so that the reflectance can be obtained. For example, it is preferable that the number of stacked layers is 161 or more because the reflectance of desired light can be further improved. The number of stacked layers is more preferably 231 layers or more, and further preferably 275 layers or more. As described above, as the number of layers increases, selective reflection due to multiple interference increases, and the reflectance can be increased. However, if the desired reflection characteristics are obtained, productivity can be increased, or a thin film can be formed. For example, the number of stacked layers may be reduced. For example, it may be 2001 layers or less, preferably 1001 layers or less.

  The layer thickness of the layer A1 in the present invention is preferably in the range of 0.06 to 0.3 μm, and the layer thickness of the layer A2 is also preferably in the range of 0.06 to 0.3 μm. The above-described polyester is used for each of the layer A1 and the layer A2, and the thickness of each layer is set within a range of 0.06 to 0.3 μm. Therefore, it becomes easy to provide the specific reflection characteristics as described above even for obliquely incident light.

  The thickness of the layer A in the laminated decorative structure of the present invention is preferably 10 μm or more, more preferably 20 μm or more, and the upper limit is 200 μm or less, more preferably 151 μm or less in consideration of handleability and the like. preferable.

  The layer A used in the laminated decorative structure of the present invention is preferably a stretched film stretched at least in a uniaxial direction, and more preferably a biaxially stretched film stretched in a biaxial direction. By making the stretched film, the refractive index of the layer A1 in the stretching direction can be increased, the difference in refractive index between the layers A1 and A2 can be further increased, and the number of layers can be reduced. The film thickness can be reduced while providing reflection characteristics.

The thickness and refractive index of the layer A1 and the layer A2 can be designed to have a desired reflection wavelength band in consideration of the reflection wavelength obtained from the following formula. In the formula, λ represents the reflection wavelength (nm), n1 and n2 represent the refractive index of each layer, and d1 and d2 represent the physical thickness (nm) of each layer.
λ = 2 (n1 × d1 + n2 × d2)

  In particular, in order to make the first reflection wavelength band and the second wavelength band different from each other, the difference in refractive index in the thickness direction between the layer A1 and the layer A2 may be increased. Specifically, the difference in the refractive index in the thickness direction between the layer A1 and the layer A2 is preferably 0.05 or more, more preferably 0.08 or more, and further preferably 0.1 or more, and the angle change to be visually recognized. As a result, the change in color associated with increases in visibility, and visibility can be improved.

  The layer A may have a thickness (for example, 1 μm or more) that does not affect optical interference. For example, you may have a surface layer on the surface of the alternately laminated body of layer A1 and layer A2. Moreover, you may have an intermediate | middle layer between the alternately laminated body of two layer A1 and layer A2. These surface layers and intermediate layers can have the same composition as layer A1 or layer A2.

(Coating layer of layer A)
In the laminated decorative structure of the present invention, from the viewpoint of ensuring the slipperiness of the layer A and / or from the viewpoint of ensuring the adhesion with the adjacent layers B and C, it is easy to slip and / or easily adhere. The coating layer is preferably provided on at least one side of the layer A.

  Examples of the resin component constituting the coating layer include a polyester resin and an acrylic resin, and it is preferable to add a lubricant (filler, wax) in order to impart slipperiness.

  Examples of the method for forming the coating layer include a method in which a coating liquid containing the composition constituting the coating layer, preferably an aqueous coating liquid, is coated on the film at any stage of forming the film as the layer A. Moreover, after forming the film as the layer A, the method of apply | coating a coating liquid on a film and forming a coating layer is mentioned.

(Manufacturing method of layer A)
Below, the method of manufacturing the layer A of the laminated decorative structure of the present invention will be described using a biaxially stretched film as an example.

  In order to obtain layer A of the laminated decorative structure of the present invention, a resin for layer A1, for example, an aromatic polyester mainly containing ethylene-2,6-naphthalenedicarboxylate unit as a main repeating unit, and a resin for layer A2 For example, a polyester containing an ethylene terephthalate component of preferably 50 mol% or more and 80 mol% or less, preferably based on all repeating units, is extruded in a state of being laminated in a desired number of laminations in a molten state, and a laminated unstretched film (sheet-like) Process). At this time, if the film thicknesses of the layer A1 and the layer A2 are laminated so as to change stepwise or continuously in the thickness direction of the film, the reflection wavelength band can be further widened. It is preferable to select it accordingly.

  The laminated unstretched film thus obtained has a film forming machine axial direction (may be referred to as a longitudinal direction, a longitudinal direction or MD), and a direction perpendicular to the thickness direction (lateral direction, width direction, TD). In some cases). The stretching temperature is preferably in the range of the glass transition temperature of the resin of the layer A1 (Tg) to (Tg + 50) ° C. In this case, the draw ratio is preferably 2 to 6 times, more preferably 2.5 to 5 times, and still more preferably 3 to 5 times. The larger the draw ratio, the smaller the variation in the plane direction of the individual layers in the layer A1 and the layer A2 due to the thinning due to stretching, so that the light interference becomes uniform in the plane direction, and the stretching direction between the layer A1 and the layer A2 The difference in refractive index and the difference in refractive index in the film thickness direction are preferable. Moreover, since the orientation of layer A1 and layer A2 advances and a thermal expansion coefficient becomes low, it is preferable that a draw ratio is large.

  As the stretching method at this time, known stretching methods such as heat stretching with a rod heater, roll heating stretching, and tenter stretching can be used. From the viewpoints of reducing scratches due to contact with the roll and stretching speed, tenter stretching is performed. preferable. The stretching in the machine direction and the transverse direction may be simultaneous stretching or sequential stretching. Moreover, it is preferable to perform a heat setting process after extending | stretching. Furthermore, a conventionally known method may be employed to adjust the heat shrinkage rate.

[Layer B]
Layer B of the laminated decorative structure of the present invention is a concealing layer. The layer B is characterized by reflecting visible light transmitted through the layer A, concealing light from the layer B side, or concealing the color of the substrate placed on the side opposite to the layer A. And Since the layer A has a characteristic of reflecting a specific wavelength of visible light at the front and at an oblique angle, when viewed from the layer A side, the visually recognized color differs depending on the reflection characteristic of the light reaching the layer B. The color can be arbitrarily selected depending on the desired design, but in order to minimize the influence of the color of the substrate placed on the surface opposite to the layer A, the layer B is 10% or more. The hiding rate is preferably 35% or more, more preferably 40% or more, still more preferably 50% or more, and particularly preferably 90% or more. The “concealment rate” is a numerical value obtained by a method described later.

  There are various methods for providing the layer B with a concealing property, and the method is not limited. For example, the layer B can be easily obtained by printing a color such as white with ink. More specifically, the layer B can be obtained by printing with ink on a substrate such as a film that does not have concealment, or the layer A can be printed with the ink by printing on the layer A. Can be. In addition, as the layer B, a polymer film containing white inert particles such as titanium oxide and barium sulfate in a polymer material may be used, or such a film may be laminated on a film having no hiding property. The layer B can be concealed. When the layer B is obtained separately from the layer A, the layer B may be laminated on the layer A by laminating it.

  Layer B preferably has a thickness of 1 to 20 μm. It is easy to set it as more preferable concealment property by setting it as this range. Too thick is uneconomical. More preferably, it is 3-15 micrometers.

[Layer C]
The layer C of the laminated decorative structure of the present invention is characterized in that one surface of the layer A is partially covered and not partially covered. As described above, since the layer A has a characteristic of reflecting a specific wavelength of visible light at the front and oblique angles, the region not covered by the layer C is a portion where the color changes depending on the angle. On the other hand, when viewed from the layer C side, the design and color difference of the layer C are visually recognized in the region covered by the layer C. By drawing the area not covered by the layer C as a character or an illustration with an arbitrary design, the color changes depending on the angle at which the drawn area is viewed, and such excellent visibility can be obtained. The layer C has a function of concealing the visible light reflection characteristics of the layer A. For example, in order to make the design property by the reflection characteristics of the layer A more conspicuous, the concealment ratio is 10% or more, preferably It is 35% or more, more preferably 40% or more, still more preferably 50% or more, and particularly preferably 90% or more. The higher the concealment rate, the higher the effect of the design property due to the shape of the portion not having the layer C, but it may be preferable to reduce the color difference between the portion having the layer C and the portion not having the layer C. The concealment rate of the layer C varies depending on the desired design and may be arbitrarily selected. In such a case, the concealment rate may be, for example, less than 50%, less than 40%, or less than 35%.

  There are various methods for creating the covering portion and the non-covering portion of the layer C, and the method is not limited. For example, the layer C can be easily obtained by printing ink in the same manner as the layer B. Further, the layer A can be laminated by laminating a separately formed layer C or the like.

  As described above, the layer C covers a part of the layer A and does not cover a part thereof, but the area ratio of the uncoated part is preferably 10% or more. By doing so, the portion where the color appears to change becomes an appropriate size, and the effect on the design is further obtained. More preferably, it is 30% or more, More preferably, it is 50% or more. On the other hand, even if the area ratio of the uncovered portion is too large, the influence on the design properties due to the shape formed by the portion covered by the layer C and the uncovered portion tends to be small. The area ratio of the uncovered portion is preferably 90% or less, more preferably 80% or less. The area ratio of the uncovered part is obtained by dividing the area of the part not covered by the layer C by the total area of the area covered by the layer C and the uncovered area. It is a ratio. In actual use, another part is provided on the layered decorative structure of the present invention, and a part of the layered decorative structure of the present invention is concealed and used so that the hidden portion is not visually recognized. In such a case, the above-described area ratio can be considered in a range visually recognized in actual use.

  The design formed by the portion covered by the layer C and the portion not covered by the layer C may be formed by “pulling” the layer C or may be formed by the layer C. In the former, the extracted part becomes a part where the color changes, and in the latter, a part around the design formed by the layer C becomes a part where the color changes.

  Layer C preferably has a thickness of 1 to 20 μm. By setting it as such a range, it is easy to make it more preferable reflectivity and concealment. Too thick is uneconomical. More preferably, it is 3-15 micrometers.

[Other layers]
When the laminated decorative structure of the present invention is used by being attached to a substrate as the other layer, an adhesive layer therefor can be provided on the surface of layer B opposite to layer A. The surface of the layer C opposite to the layer A can have a surface protective layer such as an overcoat layer for the purpose of protecting the design.

[Usage]
The laminated decorative structure of the present invention is preferably used for applications in which the viewing angle with respect to the design can change. For example, when used for a moving body such as an automobile, a train, a ship, or an airplane, when the moving body is viewed from a fixed viewpoint, the viewing angle with respect to the design changes as the moving body moves, and the color of the design changes. The effect of improving the design property can be obtained.

  The laminated decorative laminate of the present invention is also preferably used for movable bodies such as mobile phones and notebook computers. This is because, for example, the viewing angle can be changed by the opening / closing operation, and the effect of improving the design can be obtained. Furthermore, these are also mobile applications, and it is preferable for mobile applications because the effect of improving the design can be obtained by changing the viewing angle by carrying.

  In addition to those that move or move as described above, even fixed ones can be used for applications in which the viewing angle can change and the viewing angle can change. Examples include building materials.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention does not receive any limitation by this. In addition, each value in a present Example was calculated | required according to the following method.

(1) Number of layers A layered A film sample was cut into 2 mm in the longitudinal direction of the film and 2 cm in the width direction, fixed to an embedding capsule, and then embedded with an epoxy resin (Epomount manufactured by Refinetech Co., Ltd.). The embedded sample was cut perpendicularly in the film width direction with a microtome (“ULTRACUT” (registered trademark) UCT manufactured by Leica Microsystems) to obtain a thin film slice having a thickness of 50 nm. A transmission electron microscope (TECNAI-G2 manufactured by Japan FEI Co., Ltd.) was used for observation and photographing at an acceleration voltage of 120 kV, and the number of layers was measured from the photograph.

(2) Thickness (2-1) Thickness of each layer of A to C layers The total thickness of the film and the thickness of each layer of the A to C layers were determined by observation with an optical microscope of the film cross section and photography. In addition, when it has another layer, if it is the measurement range of an optical microscope, it can apply to this method.
(2-2) Thickness of A1 layer and A2 layer Thickness of each layer of A1 layer and A2 layer by analyzing an image from a photograph of an electronic optical microscope taken when measuring the number of layers A in (1) above Got. Specifically, the thickness of each of the A1 layer and the A2 layer was calculated by reading the thickness of each of the A1 layer and the A2 layer on a scale from a photograph of an electronic optical microscope and then dividing the thickness by the scale factor of the image. .

(3) Refractive index The refractive index of each layer of layer A was determined by the following method.
When the raw material for constituting the layer to be measured in layer A is crystalline, a single layer film (thickness 20 μm) obtained under the same stretching conditions as layer A is prepared using such raw material, and Abbe's refraction The refractive index of the film forming direction (nMD), the direction orthogonal to the film forming direction and the thickness direction (nTD), and the thickness direction (nTH) of the film was measured by a meter.
When the raw material for constituting the layer to be measured in layer A is amorphous, an unstretched film (thickness: 100 μm) is prepared using the raw material, and the film forming direction ( nMD), the direction perpendicular to the film forming direction and the thickness direction (nTD), and the refractive index in the thickness direction (nTH) of the film were measured.

(4) Optical characteristics An integrating sphere was attached to a spectrophotometer (Shimadzu Corporation UV-3101PC), and the reflectance with normal incident light was measured over a wavelength range of 300 to 1000 nm when the BaSO ₄ white plate was 100%. The measurement conditions were a scan speed of 200 nm / min, a slit width of 8 nm, and a sampling pitch of 2.0 nm. The reflectance was read from the obtained chart at intervals of 2 nm.
From the obtained chart, for the reflection band having a case where the reflectance is 50% or more in the visible light region, the region between the intersection of the short wavelength side intersection and the long wavelength side intersection of the 30% reflectance is first reflected. The wavelength band was defined, and the interval between the intersections was defined as the bandwidth.
Further, in the first reflection wavelength band, the median value of the wavelength in the wavelength region where the reflectance is 50% or more is set as the median value of the first reflection wavelength band. Moreover, the average reflectance in this wavelength region was defined as the average reflectance in the first reflection wavelength region.
The optical characteristics with oblique incident light were determined in the same manner. The incident angle was 60 degrees.

(5) Optical characteristics (hiding ratio)
The tristimulus values X, Y, and Z values in reflection upon light source incidence from the layer A side were calculated using a color difference meter with the layer A concealing layer provided to the layer A. At this time, the Yw value which is an arithmetic average value of the stimulus values Y measured at five different locations by arranging the white plate on the layer B side with the BaSO ₄ white plate being 100% reflectance and the blackboard being 100% absorption rate. And a ratio (value expressed as a percentage by multiplying Yb / Yw by 100) from the Yb value, which is the arithmetic average value of the stimulus value Y measured at five different locations by placing a blackboard on the layer B side, It was set as the concealment rate of B. When measuring the concealment rate of layer B, if layer C is present, measure at the portion not covered by layer C, or if this is difficult, measure by removing layer C appropriately with a solvent or the like. went.
The layer C was obtained in the same manner. When measuring the concealment rate of layer C, when layer B was included, measurement was performed with layer B appropriately removed with a solvent or the like.
Based on the obtained concealment rate, the following criteria were used for evaluation.
A: Concealment rate 90% or more B: Concealment rate 50% or more and less than 90% C: Concealment rate 40% or more and less than 50% D: Concealment rate 35% or more and less than 40% E: Concealment rate 10% or more and less than 35% F: Concealment Less than 10%

(6) Area ratio of uncovered portion of layer C When layer B and layer C are applied to layer A, if the original sample is the same or smaller than the copy paper, the sample is magnified or enlarged Prepare 10 copies that are as large as possible so that the whole fits on one copy sheet, cut out the portion corresponding to the uncovered portion of layer C, and the original sample on the remaining copy sheet The weight of both the portion corresponding to the entire size was measured, and the area ratio of the uncoated portion was determined from the weight ratio by the weight method. If the original sample is larger than the copy paper, copy the entire sample by dividing it into multiple parts at least at the same magnification, prepare 10 sets, and use the gravimetric method to determine the area of the uncoated part The percentage can be determined. When calculating the area ratio by the weight method, copy paper that is as homogeneous as possible is used, and the cutout is performed with vinyl gloves. After cutting, the temperature and humidity are controlled for 24 hours under conditions of 23 ° C. and 50% RH. I went there.

(7) Designability A red plate is installed as a background, and the sample is placed so that the layer B side is the background side, and observed from the direction perpendicular to the sample surface, from which the observation accuracy is 30 degrees, When the hue of the region where the sample is visually recognized is visually changed from the oblique direction when it is visually changed from 60 degrees and 80 degrees, the color change is observed with respect to the observation from the vertical direction, and no color change is observed. X, and although the color change was observed, the case where the hue changed due to the background color (red background) was evaluated as Δ.

(8) DSC measurement (glass transition temperature, crystallization enthalpy)
The glass transition point and crystallization enthalpy were read from the 2nd scan DSC chart after the 1st scan quenching measured under the following conditions.
Sample weight: 10mg
Apparatus: DSC8500 manufactured by PerkinElmer
Temperature conditions: (i) 1st scan: 30 to 300 ° C. (temperature increase rate 20 ° C./min), (ii) rapid cooling of the sample after holding 300 ° C. for 3 minutes (quenching condition 750 ° C./min (set value)), (iii) 2nd scan: 30 to 300 ° C. (temperature increase rate 20 ° C./min)
Environmental conditions: Under nitrogen atmosphere (100 mL / min)

[Example 1]
Polyethylene-2,6-naphthalate (hereinafter referred to as “PEN”, which was also crystalline) having an intrinsic viscosity (orthochlorophenol, 35 ° C.) of 0.62 dl / g as the polyester (A1) for the layer A1. Cyclohexanedimethanol copolymerized polyethylene terephthalate (hereinafter referred to as “PETG”) having an intrinsic viscosity (orthochlorophenol, 35 ° C.) of 0.77 dl / g obtained by copolymerizing 30 mol% of cyclohexanedimethanol as the polyester (A2) for A2. Each was prepared.

  The polyester for layer A1 (A1) was dried at 180 ° C. for 5 hours and the polyester for layer 2 (A2) was dried at 60 ° C. for 12 hours and then supplied to separate extruders. PEN was 300 ° C. and PETG was 270 ° C. Until heated to a molten state. After branching the polyester for layer A1 (A1) into 137 layers and the polyester for layer A2 (A2) into 138 layers, the polyester for layer A1 (A1) and the polyester for layer A2 (A2) alternately Protection is provided on both sides of the laminated structure part and the laminated structure part in which the ratio of the maximum layer thickness and the minimum layer thickness in each of the layers A1 and A2 is continuously changed up to 1.4 times at the maximum / minimum. Lamination was performed using a multi-layer feed block apparatus that laminated the layers, and the laminated state was guided to a die and cast on a casting drum. And the unstretched multilayer laminated film which has a protective layer which consists of polyester (A1) for layer A1 in the outermost layer of both surfaces of a film, and the total number of layers of a laminated structure part was 275 layers. The thicknesses of the protective layers on the front and back sides were each 21% with respect to the entire thickness. At this time, the discharge amounts of the layer A1 and the layer A2 were adjusted so that the average optical thicknesses of the layer A1 and the layer A2 in the laminated portion were equal.

  The unstretched film thus obtained was preheated at 120 ° C., and further heated by a 900 ° C. IR heater 15 mm above between low-speed and high-speed rolls and stretched 3.5 times in the longitudinal direction. Subsequently, it was supplied to a tenter, and the tenter was stretched 4.5 times in the transverse direction at 145 ° C. The obtained biaxially oriented polyester film was heat-fixed at a temperature of 180 ° C. for 30 seconds to obtain a film as the layer A. In the obtained layer A, the average thickness of the layer A1 was 95 nm, and the average thickness of the layer A2 was 105 nm.

  Next, a layer B obtained on one side and a layer C on the other side were formed by inkjet printing using the obtained layer A cut into an A4 plate. Layer B was a white hiding layer and was provided on the entire surface of layer A. In addition, the layer C is formed as an uncovered portion of an arbitrary design (for example, a rectangle) so as to have an area ratio of the uncovered portion of the table, and the other portion is a white hiding layer similar to the layer B as a covered portion. It was. The thickness of layer B was 10 μm, and the thickness of layer C was 10 μm.

The refractive index of the layer A1 was nMD = 1.73, nTD = 1.78, and nTH = 1.49. The refractive index of the layer A2 was nMD = 1.58, nTD = 1.58, and nTH = 1.58.
Table 1 shows the evaluation results of the obtained laminated decorative structure.

[Examples 2 and 3, Comparative Example 1]
The same operation as in Example 1 was repeated except that the total thickness was adjusted with the layer thickness ratio of layer A unchanged. Table 1 shows the physical properties of the laminated decorative structure obtained. In addition, layer B and layer C changed the design so that it might become the area ratio of the non-covering part as described in a table | surface, and adjusted thickness so that it might become the concealment rate range as described in a table | surface.

[Example 4]
The same operation as in Example 1 was repeated except that the layer B was changed to a black masking layer. Table 1 shows the physical properties of the laminated decorative structure obtained.

[Comparative Example 2]
A film as layer A was obtained in the same manner as in Example 1. Next, the layer B was formed in the direction of the obtained layer A, and the layer C was formed in the other surface by inkjet printing. Layer B was a white hiding layer and was provided on the entire surface of layer A. Layer C is formed as a non-covered portion of an arbitrary design (for example, a rectangle) so as to have an area ratio of the non-covered portion of the table, and the other portion is a white hiding layer similar to layer B as the covered portion. . The thickness of layer B was 0.5 μm, and the thickness of layer C was 10 μm. Table 1 shows the physical properties of the laminated decorative structure obtained in a state where the concealment rate of the layer B is lowered.

The laminated decorative structure of the present invention has a reflection characteristic of a specific reflection wavelength band with respect to vertical incident light, and has a reflection characteristic of a specific reflection wavelength band different from that with respect to oblique incident light. It is possible to make a design with different colors depending on the angle, and it is useful for improving the visibility and design of articles visually recognized by human eyes, such as mobility of building materials, electronics, automobiles and the like.

Claims (7)

A layered decorative structure having layer A and layer B on one side and layer C on the other side,
The layer A has a first reflection wavelength band in the visible light region for vertically incident light, a second reflection wavelength band in the visible light region for oblique incident light, and the first reflection wavelength band and the second reflection wavelength band. It is a reflection wavelength band different from the reflection wavelength band,
Layer B is a concealing layer,
The layer C covers a part of the layer A and does not cover a part thereof.
Laminated decorative structure.   The laminated decorative structure according to claim 1, wherein a difference between the first reflection wavelength band and the second reflection wavelength band is 10 nm or more.   The laminated decorative structure according to claim 1 or 2, wherein a median value of the first reflection wavelength band is 500 to 750 nm and a median value of the second reflection wavelength band is 400 to 650 nm.   The layer A is a birefringent layer A1 mainly containing an aromatic polyester mainly composed of ethylene-2,6-naphthalenedicarboxylate, and an isotropic layer A2 mainly containing an amorphous copolyester. The laminated decorative structure according to any one of claims 1 to 3, wherein the laminated film is formed by alternately laminating layers, and the laminated film transmits blue light.   The layered decorative structure according to any one of claims 1 to 4, wherein the layer B has a color that can be visually recognized as white or black.   The laminated decorative structure according to any one of claims 1 to 5, wherein an area ratio of a portion of the layer C that does not cover the layer A is 10% or more. The laminated decorative structure according to any one of claims 1 to 6, which is for a moving body.