JP3283599B2 - Coloring method using nanometer particle thin film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coloring method. More specifically, the present invention relates to a method for forming a color using a thin film of nanometer particles having a particle diameter of 200 nm or less, which can generate a uniform intrinsic color spectrum and can appropriately control the color spectrum. is there.

[0002]

2. Description of the Related Art In the field of optics, various studies have been made on a coloring technique, and some research results have been reported so far. For example, as one example of this color-forming technique, an opal color-forming method using a suspension of submicron to micron particles is known, and utilizes diffracted light derived from the regularity of the wavelength order of a three-dimensional crystal. In addition, a coloring method using diffracted light of a submicron to micron particle thin film has been proposed. This is an application of diffracted light derived from the regularity of a two-dimensional crystal in the order of wavelength. In the above coloring method, the radiation angle of the diffracted light can be made different from the incident direction.

[0003] In addition, color reflection light from a liquid or solid thin film having a thickness of 20 to 100 nm on the order of nanometers has been proposed, and interference caused by multiple reflections of the upper and lower surfaces of a uniform thin film of liquid or solid has been proposed. I use. The reflected light in this case has the property that the incident angle and the reflection angle are equal. Further, there is also a color coloring method (Chromoskedaic paintaing) using a solid suspension film of nanometer particles having a particle diameter of 200 nm or less.
This is known as a coloring method depending on the particle size by e-scattering. .

[0004]

However, in the conventional color forming methods exemplified above, for example, each of them has a problem to be improved. That is,
There is a problem that the opal light in the opal coloring method is three-dimensional light emission and does not substantially belong to the two-dimensional color coloring technique.

Further, in the case of a color forming method using diffracted light of a submicron to micron particle thin film, although it is a two-dimensional color forming technique, since the diffracted light is used, the color forming spectrum is large depending on the viewing direction and the crystal domain direction. There is a disadvantage that the color changes and the color is not unique to the object. On the other hand, in the case of a coloring method using a nanometer liquid thin film, the coloring spectrum changes due to evaporation of the liquid, and it is difficult to fix the color. In addition, the method using a nanometer solid thin film is generally widely used as a color coating method. However, since the film thickness is on the order of nanometers, control of a color spectrum and control of color uniformity are difficult. There is a problem that is difficult.

Further, as for the coloring method using a nanometer particle solid suspension film, the color spectrum cannot be controlled because the principle of coloring has not been known so far. The present invention has been made in view of the circumstances described above, and solves the drawbacks of the conventional color forming method, can generate a uniform unique color spectrum, and appropriately controls the color spectrum. 200n particle size
The purpose of the present invention is to provide a two-dimensional coloring method using a thin film of nanometer particles of m or less.

[0007]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems by providing two-dimensionally arrayed light-transmitting fine particles having a particle diameter of 200 nm or less at a nanometer scale on a substrate surface. A color developing method using a nanometer particle thin film, characterized in that a color is controlled by the reflection interference of a fine particle thin film by controlling the number thereof.

In the present invention, in order to avoid diffracted light, light-transmitting nanometer particles having a particle diameter of 200 nm or less are used, and are arranged two-dimensionally on the substrate surface. Generates a unique color spectrum as reflected light from the light source. There is no particular limitation on the type of nanometer particles other than being light transmissive, for example, polystyrene latex particles or silica, or metal fine particles such as colloidal gold or silver, ceramic particles such as titanium oxide, zirconium oxide, and aluminum oxide, Alternatively, polymer particles such as polyacrylic particles can be used. Coloring by such a nanometer particle thin film, when obtaining coloration of visible light, the particle diameter is 30 to 200 nm
And in the case of ultraviolet light, 10 to
A range of about 50 nm is preferable. Further, in order to obtain infrared light coloring, the particle diameter can be set to about 100 to 1000 nm.

Further, in the present invention, in order to enable uniform color development, the number of nanometer particle layers to be two-dimensionally arranged on the substrate surface is controlled to form a nanometer particle thin film having a uniform particle diameter. Make the thickness uniform. For example, as shown in FIG. 1, the particle diameter of the nanometer particle (1) is sufficiently smaller than that of light, so that it can be regarded as a uniform particle thin film. Due to the interference between the surface of the particle thin film and the reflected light from the surface of the substrate (2), a color is generated. Depending on the number of the particle layers of the nanometer particles, that is, the thickness of the particle thin film, as shown in FIG. The wavelength of light changes. The thickness of the nanometer particle thin film is digitally controlled by controlling the number of particle layers, and as a result, the color spectrum can be digitally controlled. As described above, by using the nanometer particles, the uniformity of the film and the appropriate film thickness are simultaneously realized.

[0010] The color development spectrum includes particle diameter and particle density, optical properties of particles such as transmittance, reflectance, and refractive index, as well as film thickness and its reflectance of a particle thin film, and reflectance of a substrate on which a thin film is formed. Dependent. Therefore, these elements are appropriately controlled to adjust the color tone of the reflected light. Explaining the principle of coloring, as shown in FIGS. 2, 3, 4 and 5, for example, the coloring spectrum (FIG. 2) is the reflection spectrum of the substrate (FIG. 3) and the reflection spectrum of the nanometer particle thin film surface. (FIG. 4) and the interference spectrum (FIG. 5) due to the particle thin film.

There is no particular limitation on the type of substrate that can be used, and examples thereof include glass, mica, and those whose surfaces are coated with a metal such as gold, silver, or aluminum. in this case,
The substrate is preferably flat with respect to the particle diameter. Therefore, any solid such as a polymer, a biological membrane, and ceramics can be appropriately selected and employed as long as the solid has a flat surface.

In forming a nanometer fine particle thin film on such a substrate, for example, a millimeter-sized circular cell (3) as shown in FIG. 6 can be used. This circular cell (3) has a hole (4) with a diameter of several mm inside.
And a partition (5) made of paraffin or the like, and the above-described substrate (2) hermetically disposed at the bottom thereof. The diameter (R) of the hole (4) inside the partition (5) can be, for example, about φ2-4 mm.

A nanometer particle solution (6) in which nanometer particles are dispersed is injected into the hole (4). The nanometer particle solution (6) can be in a state in which the particles are suspended in a solvent. As the solvent, various organic solvents such as methanol, ether, benzene, and an emulsion can be used in addition to water. . Next, the solvent component is evaporated from the nanometer particle solution (6) in an appropriate atmosphere such as air, oxygen, ozone, or the like, and two-dimensional nanometer particles are formed on the surface of the substrate (2) using the cohesive force accompanying the evaporation. Dimensionally accumulate.

[0014]

The present invention will be described in more detail with reference to the following examples. Example 1 Using a circular cell (3) illustrated in FIG. 6, a thin film of polystyrene latex having a particle diameter of 144 nm with a controlled number of particle layers was formed on a mica substrate surface, and colored by light irradiation.

In order to examine the relationship between the color development and the film thickness of the thin film, the number of particle layers of the thin film was observed and measured with an electron microscope. Table 1 shows the results.

[0016]

[Table 1]

As is clear from Table 1, it was confirmed that the color tone changes depending on the number of layers (film thickness) and the density of the particle layer. The above color development was based on the reflected light of vertically illuminating light with an episcopic microscope. Then, when the substrate was inclined by 45 ° and the color development due to oblique light reflection was observed, the same color development as in the case of the above-mentioned front reflected light was obtained. It has been confirmed that the coloring method of the present invention does not change the coloring even if the direction of the light is changed, unlike the coloring by the conventional diffracted light.

FIG. 7 (a) is an electron microscope film image showing a change from a single-layer film to a double-layer film of a 144 nm polystyrene particle thin film, and FIG. 7 (b) is a schematic sectional view thereof. . Example 2 Color development was observed in the same manner as in Example 1 except that a polystyrene latex particle thin film having a particle diameter of 55 nm was formed on a gold-deposited glass substrate. The results are also shown in Table 1.

As is clear from Table 1, it was confirmed that the color tone changes depending on the thickness of the polystyrene latex particle thin film. In addition, from the comparison with the results of Example 1, it was confirmed that the color tone changes depending on the reflection spectrum of the substrate and the particle size of the nanometer particles. Example 3 In order to further examine the relationship between the reflection spectrum and color development of the substrate, a polystyrene latex particle thin film having a particle diameter of 55 nm was formed on a carbon substrate coated with a carbon film in the same manner as in Example 2 and colored.

As a result, it was confirmed that when the carbon film was coated, the color development shifted to red as a whole as compared with the case of gold deposition. Of course, the present invention is not limited by the above examples. It goes without saying that various aspects are possible for details such as the type and size of the nanometer fine particles and the substrate.

[0021]

As described in detail above, according to the present invention, a color having a uniform intrinsic color spectrum, which is appropriately controlled in spectrum, is realized by a nanometer particle thin film having a particle diameter of 200 nm or less. A wide range of applications can be developed for light reflection filters, color photographs, color coating films, and the like.

[Brief description of the drawings]

FIG. 1 is a model diagram illustrating the principle of coloring in the coloring method of the present invention.

FIG. 2 is a spectrum diagram illustrating a color spectrum obtained by the method of the present invention.

FIG. 3 is a spectrum diagram illustrating a reflection spectrum of a substrate.

FIG. 4 is a spectrum diagram illustrating a reflection spectrum of the surface of a nanometer particle thin film.

FIG. 5 is a spectrum diagram illustrating an interference spectrum by a nanometer particle thin film.

FIG. 6 is a cross-sectional view illustrating a circular cell that can be used in the method of the present invention.

FIGS. 7A and 7B are an electron microscope image diagram and a schematic cross-sectional view of a layer configuration thereof.

[Explanation of symbols]

 Reference Signs List 1 nanometer particle 2 substrate 3 circular cell 4 hole 5 partition wall 6 nanometer particle solution

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Kuniaki Nagayama, Inventor 2-21-15 Asayakita, Suginami-ku, Tokyo (56) References JP-A-2-175601 (JP, A) JP-A-60-36355 (JP, A)

Claims (3)

(57) [Claims] 1. A single-layer or multi-layer light-transmitting fine particle having a particle diameter of 200 nm or less on a nanometer scale on a substrate surface.
Two-dimensional integrated is arranged to form a fine particle film, the different inherent color space in accordance with the number of layers by the reflection interference particle film
Coloring method according nanometers fine particles thin film characterized in that the color is developed by generating a vector. 2. A particle size, particle density, color development method according to claim 1 for adjusting the color tone by controlling the optical properties and / or reflectance of the substrate particles. 3. The color-forming method according to claim 1, wherein the particle size is 30 to 200 nm.