JP4731759B2 - Chromogen - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to a color former, particularly a color former that emits a structural color.
[0002]
[Prior art]
Unlike dyes that develop colors due to the electronic properties of molecules and solids themselves, structures that do not have color themselves and develop colors due to the effects of light reflection, interference, diffraction, etc., are less susceptible to changes with time due to ultraviolet rays and gloss. Since it has advantages such as being easy, it is expected as a painting method for automobiles and a means for coloring fibers.
As such a coloring structure, for example, one having a structure in which two kinds of polymer substances having different refractive indexes are alternately laminated (Japanese Patent Laid-Open Nos. 7-34324 and 2000-246829), and one having a lamella (special feature) Kaihei 9-157957) has been proposed.
[0003]
[Problems to be solved by the invention]
However, none of the conventionally proposed coloring structures reflect strongly or shine brightly, comparable to a morpho butterfly that is famous as a natural product having a structural color.
SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a color former whose color changes gently according to a change in the angle of viewing like a morpho butterfly, and which has gradual chromatic dispersion, deep hue and high reflectance.
[0004]
[Means for Solving the Problems]
In order to solve the problem, the color former of the present invention is
When λ is the wavelength of visible light that should be most strongly reflected in the vertical direction, a high refractive index n1 , a high refractive index layer having a predetermined thickness d1 , a width smaller than the wavelength λ , a low refractive index n2 and a predetermined refractive index. Thickness d2 and low refractive index layers having a width smaller than the wavelength λ are alternately stacked, and a plurality of stacked bodies satisfying λ = 2 (n1 × d1 + n2 × d2) are shorter than the wavelength λ by 10 nm to 300 nm. The laminates are arranged in a planar direction on the substrate at intervals of the distances , and each laminate has a height that is randomly different from the adjacent laminate in the range of 1/2 to 2 layers .
[0005]
Since the color body of the present invention has a laminate in which high refractive index layers and low refractive index layers are alternately laminated, incident light is reflected by the high refractive index layers at each stage, and among the reflected light, the light of specific wavelength λ determined by the respective refractive index and thickness of the refractive index layers and low refractive index layer or cancel or intensified by interference.
[0006]
Moreover, since the width of the laminate is smaller than that wavelength, the enhanced reflected light is spatially spread by the diffraction effect, and such laminates are arranged at intervals of 10 nm to 300 nm shorter than the wavelength. High reflectivity can be obtained by the photonic band effect. Therefore, the color gradually changes depending on the viewing angle while having a high reflectance. Note that when the interval between the stacked bodies is narrower than 10 nm, a continuum is approximately obtained, so that the spread of light due to the diffraction effect cannot be obtained. On the other hand, when the interval is larger than 300 nm, the photonic band effect cannot be obtained. Limited to street. In this respect, since none of the conventional color forming structures described above limit the interval to the wavelength λ or less, it is significantly different from not corresponding to the condition for obtaining a high reflectance.
[0007]
Furthermore, if the wavelength to be strengthened, which is determined by the thickness of each layer, is close to the wavelength of visible light and reflects most strongly in the vertical direction with respect to light having a wavelength of, for example, 480 nm (blue), a shorter wavelength, for example, a wavelength of 420 nm. reflecting stronger than 480nm the light is too reflected not but 30 degree direction in the vertical direction so canceled by the interference constructive the interference in the opposite (purple). However, the laminate is not long and continuous in the plane direction, but has a width smaller than the wavelength of light as described above. Be emitted. In this respect, all of the above conventional color forming structures are remarkably different from the case where only the summing effect of rainbow color reflection is produced.
[0008]
In order to make such an effect remarkable, as the dimensions of the laminate, the thickness of the high refractive index layer is 30 to 120 nm, the low refractive index layer is 60 to 300 nm, and the width of each laminate is 100 to 400 nm or less. It is preferable to make the low refractive index layer thicker than the high refractive index layer in order to equalize the optical distance of each layer. The substrate is not limited as long as it can fix the laminate in a predetermined arrangement. For example, when each layer is made of an inorganic dielectric thin film, which will be described later, if the glass substrate is used, the color former can be completely composed of a solid inorganic material.
[0009]
In the color body of the present invention, each laminate has a different height from the adjacent laminate in the range of 1/2 layer to 2 layers , so that the phase of the diffracted light from each laminate is a laminate. Because of the irregularity of the height, it becomes messy and speckles that interfere with each other by chance in the space, so it looks shining brightly.
[0010]
Examples of the material constituting the high refractive index layer or the low refractive index layer include Al ₂ O ₃ , SiO ₂ , SiO, SnO ₂ , Sb ₂ O ₃ , PbCl ₂ , PbO, TiO ₂ , TiO, ZrO ₂ , and CeO _2. , CeF ₃ , ZnS, MgO, NaF, MgF ₂ and other inorganic dielectric thin films are selected from the above, and the heat resistance and light resistance can be improved by using inorganic material. In addition, the range of refractive index is expanded. Among these, in order to increase the refractive index ratio and increase the reflectance, the high refractive index layer is CeO ₂ , PbO, Sb ₂ O ₃ , PbCl ₂ , TiO ₂ , ZnS, and the low refractive index layer is SiO ₂ , MgF. A combination of ₂ is preferred.
Furthermore, when a light absorber is formed between the laminate and the base material, only light of a specific wavelength is absorbed, so that the hue can be changed. Further, when the light absorber is a metal thin film made of aluminum, gold, copper, chromium, etc., gloss is added to the reflected light.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the color body of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a color body of an embodiment.
The color body 1 includes a glass substrate 2 whose surface is polished to have a random roughness of about 30 nm to 400 nm, a metal thin film 3 formed on the surface of the glass substrate 2, and a groove 7 therebetween. It is composed of a large number (4 in the drawing) of stacked bodies 4 arranged. The laminate 4 is formed by alternately laminating five steps of high refractive index layers 5 and four steps of low refractive index layers 6. The thickness D of the high refractive index layer is 30 to 120 nm, and the low refractive index is low. The layer thickness d is 60 to 300 nm, and the width W of each layer is 100 to 400 nm or less. An interval G between one stacked body and the adjacent stacked body is 300 nm or less.
[0012]
The color body 1 is manufactured through the following steps. First, the polished glass substrate 2 is prepared, and a metal thin film 3 is deposited thereon by an evaporation means such as electron beam heating evaporation or heater heating evaporation. Thereafter, the high refractive index layer 5 and then the low refractive index layer 6 are repeatedly deposited by vapor deposition means such as electron beam heating vapor deposition, heater heating vapor deposition, and reactive vapor deposition in an oxygen atmosphere. To do. Next, the color body 1 is completed by processing the groove 7 reaching at least the surface of the metal thin film 3 from the uppermost surface by an electron beam patterning device, a focused ion beam device, or a lithography technique.
The obtained color body 1 has a randomness in the height direction of 30 nm or more and 400 nm or less following the surface roughness of the glass substrate 2 in the height of the laminate 4.
[0013]
【Example】
Example 1
In FIG. 1, a color body having a structure in which the metal thin film is removed, the width W is 400 nm, the number of steps of the high refractive index layer is 6, the refractive index is 2.3, the thickness is 60 nm, and the refractive index of the low refractive index layer is 1. .46, the thickness was set to 145 nm, and the angle dependence of the reflection intensity due to normal incidence of light was calculated. Such a combination of layers is possible by setting the high refractive index layer to one selected from Sb ₂ O ₃ , PbCl ₂ , TiO ₂ , and ZnS and the low refractive index layer to SiO ₂ . For ease of calculation, it was assumed that (1) the incident light reaches the stage considered without loss at each stage, and (2) the diffracted light does not diffract again by other stages. As a result, it became like FIG.
[0014]
As shown in FIG. 2, the reflection in the vertical direction is strongest at 700 nm, and the reflection becomes weaker as the wavelength becomes shorter, while the light at 650 nm is in the direction of 30 degrees with respect to the vertical, and the light at 600 nm is The reflection in the 40 degree direction was stronger than in the vertical direction. Therefore, it can be seen that it looks red when viewed from the front, and orange when viewed from 40 degrees to the vertical.
[0015]
-Example 2-
The angle dependence of the reflection intensity due to perpendicular incidence of light was calculated under the same conditions as in Example 1 except that the thickness of the high refractive index layer was 40 nm and the thickness of the low refractive index layer was 100 nm. As a result, it became like FIG.
[0016]
As shown in FIG. 3, the reflection in the vertical direction is strongest at 480 nm, and the reflection becomes weaker as the wavelength becomes shorter, while the light of 420 nm has a reflection in the direction of 30 degrees perpendicular to the vertical. It became stronger than the direction. Therefore, it can be considered that it looks blue when viewed from the front, and green when viewed from 30 degrees to the vertical. By the way. This angular distribution is very similar to that obtained experimentally from Morpho butterflies.
[0017]
【The invention's effect】
As described above, according to the color body of the present invention, the color has a bandwidth while having mainly a color in a certain wavelength region like a morpho butterfly, emits a hue with a depth, and has high reflectivity, so it has excellent designability. Useful in various design fields.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a color body of an embodiment.
2 is a graph showing the angle dependence of the reflection intensity by the color body of Example 1. FIG.
3 is a graph showing the angle dependence of the reflection intensity by the color body of Example 2. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Color development body 2 Glass substrate 3 Metal thin film 4 Laminated body 5 High refractive index layer 6 Low refractive index layer

Claims (3)

When λ is the wavelength of visible light that should be most strongly reflected in the vertical direction, a high refractive index n1 , a high refractive index layer having a predetermined thickness d1 , a width smaller than the wavelength λ , a low refractive index n2 and a predetermined refractive index. Thickness d2 and low refractive index layers having a width smaller than the wavelength λ are alternately stacked, and a plurality of stacked bodies satisfying λ = 2 (n1 × d1 + n2 × d2) are shorter than the wavelength λ by 10 nm to 300 nm. The color development is characterized in that it is arranged in a plane direction on the substrate at an interval of and each of the laminates has a randomly different height from the adjacent laminate in the range of 1/2 to 2 layers. body. The high refractive index layer and the low refractive index layer include Al ₂ O ₃ , SiO ₂ , SiO, SnO ₂ , Sb ₂ O ₃ , PbCl ₂ , PbO, TiO ₂ , TiO, ZrO ₂ , CeO ₂ , CeF ₃ , ZnS. , MgO, NaF, color body according to claim 1 comprising one or more selected from among inorganic dielectric thin film such as MgF _2. Furthermore color-former according to claim 1 or 2 light-absorbing body is formed between the laminate and the substrate.

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