JPH11167010A - Colored light retroreflection material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a retroreflection material capable of improving the utilization efficiency of light and imparting a variety of color tones to reflected light by emphasizing the optical component of a specified wavelength area by interference and feeding back the colored light of the color tone different from incident light in an incident light advancing direction. SOLUTION: This retroreflection material 10 is provided with a resin layer 14 on a reflection substrate 12 and many transparent fine balls 16 whose grain diameter is 30-80 μm composed of glass or the like are aligned and arranged on the surface layer side. The incident light 18 made incident from an outer part advances into the fine balls 16. Then, at least a part of it is reflected from the fine balls 16 through the resin layer 14 by the reflection substrate 12, is fed back to the fine balls 16 again and advances to the outer part. An interference material layer 22 is provided on the reflection substrate 12. The incident light 18 generates the interference of light at the interference material layer 22 and the reflected light 20 presents the color tone of a wavelength emphasized by the interference action. The interference material layer 22 is constituted of titanium dioxide coated mica.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a colored light retroreflective material,
In particular, the present invention relates to a colored light retroreflective material for coloring return light.

[0002]

2. Description of the Related Art For example, a retroreflective material is used for a traffic sign for night identification or clothes, and when a beam of light such as a headlight of an automobile is irradiated, a slight angle is formed with respect to the retroreflective material. , The return light can be transmitted almost in the incident direction. That is, in so-called specular reflection, reflected light is generated so that the incident angle and the reflection angle are substantially the same, so that the reflected light does not return to the incident direction except when light is incident at right angles to the mirror surface. .

Therefore, as shown in JP-A-63-38002 or JP-A-8-60627, a relatively high refractive index microsphere having a particle diameter of about 30 to 80 μm is formed on a light reflecting layer such as a metal film. A so-called retroreflective material, which can return light substantially in the incident direction even for light incident at a certain angle, is widely used.

The above-mentioned retroreflective material is excellent in that it has a high rate of returning in the incident direction even if the light is incident at a small angle of incidence. The return of the light of the color tone is the same as that of the specular reflector.
Therefore, conventionally, in order to color the retroreflective material, a method of coloring a portion through which light passes with a highly transparent pigment or dye has been adopted.

[0005] For example, a method of coloring an aluminum deposited film below glass microspheres or a method of coloring glass microspheres themselves are used. Etc. have been used. Further, as disclosed in Japanese Utility Model Publication No. 58-55024, there is a method in which a mica having a high reflectance is used for the reflective layer and a transparent colorant is mixed with the mica.

[0006]

However, the conventional coloring mechanism of the colorant absorbs light of a specific wavelength out of the incident light and develops the remaining color, so that the light use efficiency is low and the lightness is low. And the saturation was inevitably reduced. Further, since it is necessary to use a colorant having high transparency in order to maintain high light use efficiency even after coloring, only a very limited number of colorants can be used, or light or heat of these colorants can be used. There is also a problem such as poor stability, the method of use is limited, and only a limited number of colorants can be used. Therefore, at present, it is extremely difficult to provide a retroreflective material with high designability. SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the related art, and an object of the present invention is to provide a retroreflective material having high light use efficiency and capable of imparting various colors to reflected light.

[0007]

In order to achieve the above object, a colored light retroreflective material according to the present invention imparts a phase difference to a part of incident light and recombines the same to convert light components in a specific wavelength region. It is characterized in that colored light having a color tone different from that of the incident light is emphasized by interference and returned in the incident light entering direction.

[0008] The reflecting material according to the present invention includes a reflecting substrate and transparent microspheres arranged on the substrate, and on the reflecting substrate, an interference substance layer for producing a colored interference color is provided. Preferably, it is provided.

Further, in the above-mentioned reflecting material, it is preferable that the reflecting material includes a substrate and transparent microspheres arranged on the substrate, and an interference substance layer is provided on a surface of the transparent microsphere facing the substrate. It is suitable.

[0010] In the above-mentioned reflector, it is preferable that a scale oxide powder coated with metal oxide is used for the interference substance layer. In the reflector, the metal oxide-coated flaky powder is preferably a titanium dioxide-coated mica having a titanium oxide layer thickness of 40 nm or more and / or a low-order titanium oxide-coated mica.

In the above-mentioned reflecting material, it is preferable that the reflecting substrate has a color tone different from the interference color of the titanium oxide-coated mica. In the reflector, the metal oxide-coated flaky powder is preferably a titanium-based composite oxide-coated mica having an appearance color different from the interference color. In the reflection material, it is preferable that a surface metal oxide thin film is used for the interference substance layer.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present inventors have utilized light interference to color reflected light from a retroreflective material. That is, in the case of a retroreflective material, unlike ordinary mirror reflection, light refraction occurs a plurality of times in the retroreflective material. By interposing a substance that produces colored interference light in this optical path, it is possible to impart an interference color to the return light.

[0013]First embodiment  FIG. 1 schematically shows a retroreflective material according to an embodiment of the present invention.
The configuration is shown. In FIG.
Is to provide a resin layer 14 on a reflective substrate 12,
Transparent fine particles of glass or the like with a particle diameter of 30 to 80 μm on the side
A large number of small balls 16 are arranged.

The incident light 18 incident from the outside is
Proceed into the microsphere 16. Then, at least a part thereof is reflected by the reflective substrate 12 from the transparent microspheres 16 via the resin layer 14, returns to the microspheres 16 again, and proceeds outward.
Since the surface protruding outward of the microsphere 16 is a spherical surface,
Even if there is a slight change in the incident angle, the same effect is produced, and the reflected light 20 can be returned in the incident direction.

A feature of the present invention is that the interference of light is used to color the reflected light 20. For this reason, in this embodiment, an interference substance layer 22 is provided on the reflective substrate 12. ing. As a result, the incident light 18 causes light interference in the interference substance layer 22, and the reflected light 18
Has a color tone of a wavelength that is emphasized by the interference effect.

That is, as shown in FIG. 2, the interference substance layer 22 is composed of titanium dioxide-coated mica in the present embodiment, and the titanium dioxide-coated mica 22 has a scale-like mica 24 and a coating on the mica 24. Titanium dioxide layer 26
It is composed of Then, a part 20a of the incident light 18
Is reflected on the surface of the titanium dioxide layer 26 and further partially
Ob is reflected at the interface between the mica 24 and the titanium dioxide layer 26. The reflected light 20a and the reflected light 20b have an optical path difference about twice as large as that of the titanium dioxide layer 26. Of the wavelength components of the reflected light 20a and the reflected light 20b, a component whose optical path difference is an odd multiple of a half wavelength is amplified. And the component that is an integral multiple of the wavelength is attenuated. As a result, by adjusting the thickness of the titanium dioxide layer 26, the reflected interference light 28 having a desired color tone can be obtained. The colored reflected interference light 28 is returned by the transparent microsphere 16 in substantially the same direction as the incident light optical path, as shown in FIG.

In this embodiment, if the reflectance of the mica 22 coated with titanium dioxide is increased, the colored reflected interference light 28 is strongly observed from the return direction. As described above, according to the colored light retroreflective material 10 according to the present embodiment,
Since the interference effect of light is used to add color to the return light,
Light utilization efficiency is extremely high, and any color tone can be obtained by adjusting the layer thickness of titanium dioxide.
Further, since the substance that causes the interference color is a chemically and optically stable inorganic substance, titanium dioxide-coated mica, it can be a colored light retroreflective material having excellent heat resistance and weather resistance. In the case of mica coated with titanium dioxide, the following relationship is recognized between the layer thickness of titanium dioxide and the interference color.

[0018]

[Table 1] Interference color Geometric thickness of titanium dioxide (nm)  Silver 20-40 Gold 40-90 Red 90-110 Kaoru 110-120 Blue 120-135 Green 135-155 Second order gold 155-175Second Order Kaoru 175-200   Therefore, the amount of titanium dioxide-coated mica used in this embodiment is
The geometric layer thickness is preferably at least 40 nm.

[0019]Second embodiment  2, the light transmission of the titanium dioxide-coated mica 22
Adjust the reflection ratio to increase the reflection ratio by the reflection substrate 12
And the reflected light 30 by the reflective substrate 12 can be observed.
You. Therefore, by making the reflective substrate 12 colored, the return light
The color tone 20 reflects the colored reflected interference light 28 and the substrate color.
The reflected light 30 is synthesized. In this case,
From the direction other than the return direction, the colored reflected interference light 28
Hardly observed, the color tone of the reflective substrate 22 was observed,
For example, a beam of light from an automobile headlight
Light from the light source direction and the light from the other direction
The light emitted can be observed in different tones.

[0020]Third embodiment  FIG. 3 shows a colored light retroreflection according to the third embodiment of the present invention.
A material is disclosed, and a portion corresponding to the first embodiment is provided.
Is indicated by the reference numeral 100, and the description is omitted. This implementation
The characteristic feature in the form is that the
That is, mica coated with a titanium-based composite oxide of a color was used.

Also in this case, similarly to the second embodiment,
The feedback light 128 is observed by combining the color tone of the composite oxide 126 and the interference color based on the optical path difference by the composite oxide layer, while the color tone observed from a direction other than the light source direction is the original composite oxide coating. The color tone of mica 126 is obtained.

[0022]Fourth embodiment  FIG. 4 shows a colored light retroreflection according to the fourth embodiment of the present invention.
The main parts of the material are shown, and the parts corresponding to FIG.
The reference numeral 200 is added and the description is omitted. The dress shown in the figure
The colored light retroreflecting material 210 is a transparent microsphere
216 is attached to the buried surface of the resin layer 214. In addition,
As described above, as an interfering substance to be attached,
Titanium dioxide coated mica or colored complex acid
For example, oxide-coated mica can be used.

In this case, the reflection is repeatedly returned in the microsphere 216 and the interference substance layer 222 due to a difference in refractive index between the transparent microsphere 216 and the interference substance 222, or is reflected by the reflection substrate 212 and returned. Is determined.
Even when light passes through the interference substance layer 222 and is reflected by the reflection substrate 212, so-called transmitted interference light is generated when the light passes through the interference substance 222, so that colored feedback light can be obtained.

[0024]Fifth embodiment  FIG. 5 shows a colored light retroreflection according to the fifth embodiment of the present invention.
The main parts of the material are shown, and the parts corresponding to FIG.
The reference numeral 300 is added and the description is omitted. As shown in FIG.
The retroreflective material 310 is used to directly form the interference substance layer 322 on the reflective substrate 3.
12. Then, the surface of the interference substance layer 322
The reflected light 320a reflected by the
A specific color tone is produced by interference with the reflected light 320b.
Obtainable.

[0025]Sixth embodiment  FIG. 6 shows a colored light retroreflection according to the sixth embodiment of the present invention.
The main parts of the material are shown, and the parts corresponding to FIG.
The reference numeral 400 is added and the description is omitted. As shown in FIG.
The retroreflective material 410 forms the interference substance layer 422 with the transparent microsphere 41.
6 is formed on the buried surface of the resin layer 414. In this case
Provided a reflection layer 440 on the outer periphery of the interference substance layer 422 further.
The interface between the transparent microsphere 416 and the interfering substance layer 422
Light 420a reflected by the reflective layer 440 and reflected light 420 reflected by the reflective layer 440
A specific color tone can be obtained by interference with b.

The interference substance used in the first to fourth embodiments is preferably a coherent flaky powder typified by the titanium dioxide-coated mica. Examples of the scaly powder serving as a core of the coherent scaly powder include, for example, powders of metal aluminum, metal titanium, stainless steel, or plate-like iron oxide, plate-like silica,
Inorganic plate oxides such as plate titanium oxide and plate alumina,
Or muscovite, biotite, sericite, kaolinite,
Examples include layered compounds such as talc and organic polymer foils such as PET resin films and acrylic resin films, but the flaky powder used in the present invention is not particularly limited to these. Note that, in order to improve the light utilization rate, it is preferable to use a flake-like powder having light transmittance. The particle size of the flaky powder used in the present invention is not particularly limited, but is preferably 1 to 200 μm, particularly preferably 10 to 12 μm.
A flat one at 0 μm tends to exhibit beautiful gloss and interference colors.

In order to impart an interference color to these scaly powders, it is common to coat the surface of the scaly powders with a metal oxide, such as titanium dioxide, iron oxide, Titanium oxide, zirconium oxide, silicon oxide, aluminum oxide, cobalt oxide, nickel oxide, cobalt titanate, etc., and Li ₂ CoTi ₃ O ₈ or K
Examples thereof include composite oxides such as NiTiO _X and mixtures of these metal oxides, but are not particularly limited as long as they are metal oxides capable of exhibiting interference colors. The coating on the flaky powder of these metal oxides,
It can be performed by a method of heating or neutralizing and hydrolyzing the organic or inorganic salt of these metal oxides, or by a vapor deposition operation such as CVD or PVD.

The surface of these coherent flaky powders may be subjected to a surface treatment with an organic or inorganic compound as required. Further, the method of using the coherent flaky powder used in the present invention is not particularly limited, and any combination with a conventional coloring agent and the order of addition can be adopted as long as an interference color appears.

Further, as the interference substance layer used in the fifth and sixth embodiments, a metal film having an interference color obtained by oxidizing the surface of the metal film can be used. These metal films are prepared by a method of anodizing metal aluminum, metal titanium, stainless steel film, or the like, a method of preparing a metal oxide capable of expressing the interference color by a sol-gel method, and coating the same, or a method of coating the interference color. Is applied to a metal film by applying a metal alkoxide capable of exhibiting the above, and this is thermally decomposed, and a vapor deposition operation method such as CVD or PVD.

The colored light retroreflective material according to the present invention, which is excellent in the use efficiency of light colored by an interference color, can be used for daily goods such as marking films, shoes, bags, hats, clothing, furniture,
Electric products, buildings, automobiles, bicycles, printed matter, or paper, plastics, molded products such as metal can be given high designability, and the colored light retroreflective material according to the present invention was used for such products. In this case, it is also useful for preventing forgery.

[0031]

Embodiments of the present invention will be described below. First, a method for producing the coherent flaky powder suitably used in the present invention will be described.

[Preparation Example 1] 50 parts by weight of mica is added to 500 parts of ion-exchanged water, and sufficiently stirred to be uniformly dispersed.
To the obtained dispersion, 208.5 parts of a 40% by weight aqueous solution of titanyl sulfate was added, and the mixture was boiled for 6 hours while stirring. After cooling, the mixture was filtered, washed with water, and fired at 900 ° C. to obtain 90 parts of titanium dioxide-coated mica having a green interference color. The titanium dioxide-coated mica obtained in Production Example 1 was the first,
It can be used in 2, 4 embodiments.

[Production Example 2] 50 parts of mica was replaced with 5 parts of ion-exchanged water.
The resulting mixture was added to 00 parts and sufficiently stirred to be uniformly dispersed. An aqueous solution of titanyl sulfate having a concentration of 40% by weight was added to the obtained dispersion.
12.5 parts were added, and the mixture was heated with stirring and boiled for 6 hours. After allowing to cool, it was filtered, washed with water, and fired at 900 ° C. to obtain 100 parts of mica coated with titanium dioxide having green interference. Next, metal titanium 1.
Two parts were mixed, and the mixture was mixed with an oil diffusion pump for 1 hour.
It was reduced by heating at 800 ° C. for 4 hours at a degree of vacuum of 0 ⁻³ Torr or less. Vivid blue-green low order titanium oxide / titanium dioxide coated mica 1 with pearly luster in both appearance color and interference color after cooling
01.2 parts were obtained. The low-order titanium oxide-coated mica obtained in Production Example 2 can also be used in the first, second, and fourth embodiments, and it is possible to obtain return light having a particularly clear color tone.

[Production Example 3] 100 parts of mica titanium (Iriodin 235) produced by Merck, Germany, were subjected to a reduction treatment at 800 ° C. for 4 hours under an ammonia gas flow at a flow rate of 3 l / min. Vivid blue-green titanium oxynitride / titanium dioxide-coated mica 9 with pearl luster in both appearance color and interference color after cooling
8.5 parts were obtained. The titanium oxynitride / titanium dioxide-coated mica obtained in Production Example 3 can also be used in the first, second, and fourth embodiments, and it is possible to obtain return light having a particularly clear color tone.

[Production Example 4] 100 parts of the green interference mica titanium obtained in Production Example 2 was added to 200 parts of ion-exchanged water, stirred and uniformly dispersed. 10% concentration in the resulting dispersion
Was added at 80 ° C. over 3 hours while maintaining the pH at 4 to 5 with a 1 M aqueous sodium hydroxide solution, followed by filtration, washing with water and drying at 105 ° C. to obtain 102 parts of mica titanium oxide-coated cobalt hydroxide. Next, 100 parts of the obtained hydrated cobalt oxide-coated mica titanium and lithium carbonate 1
1.5 g was uniformly mixed by a small stirrer, and the obtained mixed powder was put in a magnetic crucible and calcined at 900 ° C. for 4 hours.
Thus, 105 parts of Li ₂ CoTi ₃ O ₈ -coated mica titanium having a vivid green color was obtained. The titanium-based composite oxide-coated mica obtained in Production Example 4 can be used in the third and fourth embodiments.

[Production Example 5] 50 parts of mica was replaced with ion-exchanged water 5
The resulting mixture was added to 00 parts and sufficiently stirred to be uniformly dispersed. 350 parts of 2M titanyl sulfate was added to the obtained dispersion, and the mixture was heated with stirring and boiled for 3 hours. After cooling, the mixture was filtered, washed with water, and dried at 200 ° C. to obtain 90 parts of mica coated with titanium dioxide. Next, 50 parts of the obtained titanium dioxide-coated mica was added to 500 parts of ion-exchanged water, stirred, and uniformly dispersed. To the resulting dispersion, 295 parts of a 0.42 M aqueous nickel chloride solution was added over 3 hours at 80 ° C. while maintaining the pH at 4 to 5 with a 1 M aqueous sodium hydroxide solution, followed by filtration and washing with water.
After drying at 05 ° C., the titanium oxide containing hydrous nickel mica was used.
8 parts were obtained.

Next, 2.75 parts of the obtained water-soluble nickel mica titanium and potassium chloride were uniformly mixed by a small mixer, and the mixture was placed in a magnetic crucible and calcined at 900 ° C. for 3 hours to obtain a bright yellow color. 51.0 parts of a glossy powder having the appearance color and the interference color of red were obtained. The titanium-based composite oxide-coated mica obtained in Production Example 5 can be used in the third and fourth embodiments. Next, the present invention will be described with reference to examples.

Example 1 A silicone resin solution was applied to the entire polyester film having a thickness of 50 μm and dried to such an extent that the resin did not flow.
The transparent glass microspheres having a mesh size of 00 to 250 were scattered and adhered and dried so as not to bury the hemisphere or more, and then heat-treated at 120 ° C. for 3 minutes to temporarily adhere the glass microspheres. Next, Production Example 1 based on the compounding ratio in Table 2
The pattern is screen-printed on the glass fine particle temporarily adhered surface of the film on which the transparent glass fine particle spheres are temporarily adhered with a transparent coloring screen printing ink containing green interference mica titanium, and the pattern is not dried until the pattern is dried. Spray nylon mesh fine particles on the mesh and dry.
For 5 minutes or more to obtain a retroreflective pattern film (transfer film) exhibiting green reflected light of the same color as the interference color of the green interference mica titanium.

[0039]

[Table 2]  Acrylic resin solution (concentration: 45 w / w%) 100 parts Green interference mica titanium of Production Example 1 (particle size: 10-60 μm) 30 partsOther additives

Example 2 When a silicone resin solution was applied to the entire surface of a polyester film having a thickness of 50 μm and dried to such an extent that the resin did not flow, the refractive index was 1.9.
After transparent glass fine particles of 00 to 250 mesh were sprayed and adhered and dried so as not to bury the hemisphere or more, they were heat-treated at 120 ° C. for 3 minutes to temporarily adhere the glass fine particles. Next, a pattern was screen-printed on a polyester film on which the glass microspheres were temporarily adhered using a transparent coloring screen printing ink having a compounding ratio shown in Table 3.
Next, aluminum was vacuum-deposited on this film so as to have a thickness of 80 nm. Further, an acrylic resin solution was applied to the surface, and while the solution was not dried, nylon resin fine particles of 80 to 250 mesh were sprayed and adhered and dried.
Heat treatment was performed at 5 ° C. for 5 minutes or more to obtain a retroreflective pattern film (transfer film) exhibiting bluish green reflected light close to the same color as the appearance color (interference color) of the low order titanium oxide / titanium dioxide coated mica.

[0041]

[Table 3]  Acrylic resin solution (concentration 45w / w%) 100 parts Blue-green low-order titanium oxide / titanium dioxide-coated mica of Production Example 2 (particle size 10-60 μm) 30 partsOther additives

Example 3 A silicone resin solution was applied to the entire surface of a polyester film having a thickness of 50 μm and dried to such an extent that the resin did not flow.
The transparent glass microspheres having a mesh size of 00 to 250 were scattered and adhered and dried so as not to bury the hemisphere or more, and then heat-treated at 120 ° C. for 3 minutes to temporarily adhere the glass microspheres. Next, a pattern was printed on a polyester film on which the glass microspheres were temporarily adhered using a transparent coloring screen printing ink containing a glossy powder having a vivid yellow appearance color and a red interference color according to the compounding ratio in Table 4. .

Next, the printing surface was coated with aluminum powder having an average particle diameter of 20 μm using an acrylic paint with a clearance of 0.1 μm.
It was painted using a 01 mm applicator. Then, an acrylic resin solution is applied to the surface, and before the solution is dried, 80 to 250 mesh nylon resin fine particles are sprayed and dried, and heat treatment is performed at 140 ° C. for 5 minutes or more. A red retroreflective pattern film (transfer film) was obtained.

[0044]

[Table 4]  Acrylic resin solution (concentration: 45 w / w%) 100 parts Glossy powder having a yellow appearance color and red interference color of Production Example 5 (particle size: 10-60 μm) 30 partsOther additives

Example 4 A refractive index of 1.9 and 200 to 2
100 g of 50 mesh transparent glass microspheres
While dispersing in 0 ml of isopropyl alcohol, 150 g of titanium tetraisopropoxide solution was added,
Next, 100 ml of a 1: 1 mixed solution of water / isopropyl alcohol was added dropwise at a rate of 5 ml / min while maintaining the dispersion at 30 ° C. After dropping, stirring was continued for 4 hours, followed by filtration, washing with water,
After drying at 200 ° C. for 3 hours, transparent glass microspheres having a yellow interference color were obtained. Next, a silicone resin solution is applied to the entire surface of the polyester film having a thickness of 50 μm, and when the resin is dried to such an extent that the resin does not flow, the transparent glass particle sphere having the yellow interference color prepared above is sprayed to form a hemisphere. After drying it in a single layer so that it does not bury,
Heat treatment was performed at 120 ° C. for 3 minutes to temporarily adhere glass microparticle spheres. Separately, a pattern was screen-printed on the glass fine particle temporarily adhered surface of the film on which the transparent glass fine particle spheres were temporarily adhered with the transparent coloring screen printing ink containing titanium mica of Production Example 4, and the pattern was dried before drying. ~
Nylon resin fine particles of 250 mesh were sprayed and dried, and heat-treated at 140 ° C. for 5 minutes or more to obtain a retroreflective pattern film (transfer film) exhibiting yellow reflected light.

In the retroreflective material according to the present invention, a glass sphere used so that a pattern or a character drawn by an interference color of an interfering substance can be clearly observed when a linear light having a certain direction is irradiated. Has a refractive index of 1.7 to 2.2,
Particularly preferably, 1.8 to 2.1, and the average particle diameter is 20 to 6.
It is suitable that it is 0 μm, particularly preferably 30 to 50 μm.

If the refractive index of the glass sphere is larger or smaller than this value, the focus is blurred and clear reflected light cannot be obtained. If the particle diameter of the glass sphere is smaller than this value, the glass particles will be buried in the resin layer, or the effective incident portion of light that can be retroreflected will be narrowed. On the other hand, if the particle diameter of the glass sphere is larger than this value, when the interference substance is screen-printed on the glass particles as described in Examples, the printing becomes difficult. In addition, it is difficult to adjust the focal length, and furthermore, there arises a problem that ink enters the gap between the glass balls.

In the case where a PET film is used for the outermost layer of the present invention as described in the examples, PET which is the outermost layer
The thickness of the film is 23 to 150 μm, particularly preferably 3 to 150 μm.
It is preferably from 8 to 50 μm. From this value PE
If the thickness of the T film is large, it is difficult to adjust the focal length, and if the thickness is thin, the production is difficult because the film is soft.

The retroreflective material according to the present invention, when used in a product as described above, can exhibit extremely high anti-counterfeiting properties. The interference substance in the retroreflective material according to the present invention produces an interference color when irradiated with linear light having a certain direction at a higher intensity than surrounding light. Therefore, when the retroreflective material according to the present invention irradiates linear light with an intensity higher than that of the surrounding light, an interference color due to an interference substance can be observed from the irradiation direction.

However, under normal light such as sunlight or illumination, light has various directions, and therefore enters the retroreflective material of the present invention from various directions. Then, the incident lights interfere with each other in various ways, making it difficult to observe the interference color. For this reason, it is difficult to observe interference colors from directions other than the linear light incident direction. Therefore, by using the retroreflective material of the present invention in the product, when irradiating linear light, the pattern or character is raised by the interference color of the interfering substance, so that the product is authentic or forged. It is possible to determine whether the product is a product.

Further, by utilizing the difference in color between the linear light of the interfering substance and that shown under normal light, the position at which the interfering substance is arranged is manipulated, so that the pattern and the interference color produced when the linear light is irradiated are obtained. By drawing letters etc.,
Even if the appearance color and the color synthesized by the substrate color and the appearance color of the interference substance appear to be a single color under normal light, the design or character can be observed under linear light. In addition, by drawing different designs and characters with the color shown under normal light and the color shown under linear light, you can observe patterns and characters observed under normal light and It is possible to use different patterns and characters to be provided, and it is possible to impart high anti-counterfeiting properties together with the design.

As described above, when the retroreflective material according to the present invention is used in a product, it is difficult to copy by a copy machine or the like because of the retroreflective property, and whether the irradiated light is ordinary light, Since different colors can be shown depending on whether it is linear light or not, the retroreflective material used in the product is illuminated with linear light using a linear light irradiator that emits linear light. By examining such factors, it is possible to immediately discriminate between a counterfeit product and an authentic product.

[0053]

As described above, according to the colored light retroreflective material of the present invention, the color tone is imparted by the interference action between the incident lights, so that the color tone has a wide selectivity and the light can be used. Excellent efficiency. Further, in the present invention, a titanium dioxide-coated mica or a low-order titanium oxide-coated mica having a high light transmittance is used as an interference substance, and the substrate color is colored. The synthesized color tone is observed, and the color of the substrate is observed from other directions, so that the design can be improved.
Further, in the present invention, by using a titanium-based composite oxide-coated mica as the interference substance, a combined color tone of the composite oxide color and the interference color is observed from the incident light return direction,
The complex oxide color is observed from other directions, and the design can be improved.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a schematic configuration of a colored light retroreflective material according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a main configuration of a colored light retroreflective material according to first and second embodiments of the present invention.

FIG. 3 is an explanatory diagram of a main configuration of a colored light retroreflective material according to a third embodiment of the present invention.

FIG. 4 is an explanatory diagram of a main configuration of a colored light retroreflective material according to a fourth embodiment of the present invention.

FIG. 5 is an explanatory diagram of a main configuration of a colored light retroreflective material according to a fifth embodiment of the present invention.

FIG. 6 is an explanatory diagram of a main configuration of a colored light retroreflective material according to a sixth embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 colored retroreflective material 12 reflective substrate 16 transparent microsphere 22 interference substance 24 scaly mica 26 titanium dioxide layer

Claims (8)

[Claims] 1. A coloring method in which a part of incident light is given a phase difference and recombined, and a light component in a specific wavelength region is enhanced by interference, and coloring light having a color tone different from that of the incident light is returned in the incident light entering direction. Light retroreflective material. 2. The reflection material according to claim 1, further comprising: a reflection substrate; and transparent microspheres aligned on the substrate, wherein an interference substance layer that produces a colored interference color is formed on the reflection substrate. The colored light retroreflective material is provided with: 3. The reflecting material according to claim 1, further comprising: a substrate; and transparent microspheres arranged on the substrate, wherein an interference substance layer is provided on a surface of the transparent microsphere facing the substrate. A colored light retroreflective material, comprising: 4. The colored light retroreflective material according to claim 2, wherein the interfering substance layer is made of scale oxide powder coated with metal oxide. 5. The coloring material according to claim 4, wherein the metal oxide-coated flaky powder is a titanium dioxide-coated mica and / or a low titanium oxide-coated mica having a titanium oxide layer thickness of 40 nm or more. Light retroreflective material. 6. The colored retroreflective material according to claim 5, wherein the reflective substrate has a color tone different from the interference color of the titanium oxide-coated mica. 7. The colored light according to claim 4, wherein the metal oxide-coated flaky powder is a titanium-based composite oxide-coated mica having an appearance color different from the interference color. Retroreflective material. 8. The colored light retroreflective material according to claim 2, wherein a metal oxide film on the surface is used for the interference substance layer.