JP4628474B2 - Structural color developing body and method for producing the same - Google Patents

Description

  The present invention relates to a structural color developing body having optical coherence and a method for producing the same.

Colors that exist in nature can be broadly divided into pigment colors (chemical coloring) such as pigments and pigments, and structural colors due to light interference. The pigment color is the color that can be seen when the light energy changes to the electronic energy of the material.For example, the reflected color is the remaining color that is absorbed and transmitted by the material, and the transmitted color is the remaining color that is absorbed and reflected. is there.
While this dye color has the advantage that it can be chemically developed by a very simple operation by simply applying a chemical color former such as a dye or pigment to an object and drying it, it uses a dye or pigment substance. Therefore, in recent years, it has been regarded as a problem from the viewpoint of recyclability and environmental protection, and also has a problem that cannot be solved essentially, such as fading due to ultraviolet rays.

  On the other hand, the structural color due to optical coherence is caused by the fact that the substance itself does not have a pigment, so there is no exchange of energy between the light and the substance, and it has a fine structure with a wavelength of light in the visible region or less. A color developed by optical phenomena such as light interference, diffraction, scattering, and photonic crystals. Examples of typical structural colors include morpho butterfly wings, peacock feathers, iridescent shells and opal play colors in nature. Regarding the coloration principle of these structural colors, for example, Morpho butterfly wings exhibit a unique “brilliant blue” color because of the regular shelf structure with streaks on the scales of Morpho butterfly wings spaced about 0.2 μm It has been clarified that this is because of the intense blue structural color due to the multilayer film interference (see, for example, Non-Patent Documents 1 and 2).

In recent years, a method of artificially forming a structure exhibiting a structural color (hereinafter referred to as “structural color developing body”) has attracted attention.
For example, by using focused ion beam CVD, which is one of the nanotechnology, it is possible to create almost the same structure as the shelf structure on the scales of morpho butterfly wings, and to reproduce the wing color unique to morpho butterflies. (For example, see Non-Patent Document 3). However, since this method requires the use of an expensive device, the cost is high, the manufacturing process is complicated, and there is a problem in mass productivity.

It has been known for a long time that rod-like or plate-like colloidal particles in a solvent settle by gravity and self-assemble to develop a structural color (for example, Non-Patent Document 4). For example, rod-like colloidal particles such as vanadium oxide (V), tobacco mosaic virus, myosin, fibrin, and benzoperpurine aggregate in the sol state and exhibit optical anisotropy. A sol that naturally exhibits optical anisotropy is called a tacttosol, and a phenomenon caused by a group of particles in which colloidal particles of a tactsol are arranged in parallel is called a tactoid. Plate-like colloidal particles such as old iron hydroxide colloid sol and tungsten oxide sol are arranged to form a layer (layer spacing: about 200 to 400 μm), and the layers are regularly arranged in the vertical direction toward the bottom of the container. Due to this regular layer arrangement, the reflected light exhibits a red or blue structural color (interference color). This arranged layer is called a Schiller layer or a multicolored layer (iridescent layer). The formation of the layer is very reproducible. After shaking and standing, the original layer is formed again. Is done.
On the other hand, as another method for artificially forming the structural color developing body, there is a method of regularly arranging spherical particles of the order of μm such as silica. There are many researches on structural color developing bodies formed by, for example, a method in which spherical particles are naturally settled and deposited, or electrophoresis is used to accumulate spherical particles on a substrate. Patent Documents 5 and 6).

Shuichi Kinoshita, Shinya Yoshioka and Kenji Kawagoe “Mechanisms of structural color in the Morpho butterfly: cooperation of regularity and irregularity in an iridescent scale” Proc. R. Soc. Lond. (2002). B269, pp. 1417 to 1422 Shuichi Kinoshita, Shinya Yoshioka “Structural colors of insects, especially morpho butterflies” Textile and Industrial (Seni to Kogyo) Vol. 59 (2003) pp. 35-39 Keiichiro Watanabe, Takayuki Hoshino, Kazuhiro Kanda, Yuichi Haruyama, Shinji Matsui “Brilliant Blue Observation from a Morpho-Butterfly-Scale Quasi-Structure” Jpn. J. Appl. Phys. (2005), Vol. 44, pp. L48-L50 H. Zocher “Die optischen Methoden zur Untersuchung der Anisotropie in Kolloiden” Z. Anorg. Allg. Chem. 147, 91 (1925). Koji Yoshinaga, Tsuneo Kobayashi, Hiroyuki Karakawa, “Preparation of Monodispersed Polyelectrolyte-Modified Colloidal Silica and Control of Surface Zeta Potential” Polymer Papers (Koubunshi Ronbunsyu), Vol. 57, no. 4 (2000), pp. 244-250 Hiroshi Fudouzi, Younan Xia, “Photonic Papers and Inks: Color Writing with Colorless Materials”, Advanced Materials, (2003), Vol. 15, no. 11, June 5, pp. 892 to 896

In this way, with the development of nanotechnology, a fine structure has been created, and applied research and development of structural color developing bodies has progressed rapidly.
However, what is mainly used as a structural color developing body at present is a spherical particle made of silica or the like disclosed in Non-Patent Documents 5 and 6, etc., but by self-assembly of the spherical particles such as silica. The formed colloidal crystal thin film (structural color chromophore) requires a long time to be immobilized on the substrate, and has a problem in mass productivity. Further, many spherical silica particles having a single particle diameter are expensive, and the formed colloidal crystal thin film (structural color developing body) is expensive.
On the other hand, the structural color body formed by the self-organization of inexpensive iron hydroxide (III) colloid is stable only in the sol state, and is taken out from the sol by drying in the state of the structural color. Is extremely difficult.
In this way, in contrast to dye colors (chemical coloring) that can be developed with a very simple operation by simply applying a chemical coloring agent such as a dye or pigment to an object and drying it, In fact, a structural color developing body that enables stable and durable structural color development has not yet been developed.

  Under such circumstances, an object of the present invention is to provide a structural color developing body that can be formed by a simple operation such as coating and drying, and has high mechanical strength, chemical stability, and thermal strength. It is in.

  As a result of intensive studies to solve the above problems, the present inventors have formed a thin film formed by self-organization in the course of evaporation of a mixed solvent containing a mixture of iron (III) hydroxide colloid and lead halide. As a result, the present inventors have found that the structural colored body exhibits a clear structural color and that the structural colored body is extremely excellent in mechanical strength, chemical stability, and thermal strength.

That is, the present invention relates to the following invention.
<1> It is obtained by mixing a solution (A) containing iron (III) hydroxide colloid and a solution (B) containing lead halide to form a mixed solution, and then removing the solvent from the mixed solution. A structural color developer.
<2> The structural color developer according to claim 1, wherein the molar ratio of iron (III) hydroxide and lead halide contained in the mixed solution is in the range of 1.0 to 25.
<3> The structural color developing body according to <1> or <2>, wherein the solvent of the solution (A) is water and the solvent of the solution (B) is ethanol.
<4> The structural color developing body according to <3>, wherein the solvent of the mixed solution is removed by evaporating and drying the solvent under conditions of a temperature of 20 to 35 ° C. and a relative humidity of 40 to 80%. .
<5> The structural color body according to any one of <1> to <4>, wherein the lead halide is lead (II) iodide.
<6> The solution (A) is previously filtered through a filter or filter paper having a pore size or a retained particle size of 0.2 to 5 μm, and then mixed with the solution (B). The structural color developing body described.
<7> A step of mixing a solution (A) containing iron (III) hydroxide colloid and a solution (B) containing lead halide to form a mixed solution, evaporating the solvent from the mixed solution, and drying A process for producing a structural color developing body.
<8> The structural color developing body according to <7>, wherein the solvent of the mixed solution is removed by evaporating and drying the solvent under conditions of a temperature of 20 to 35 ° C. and a relative humidity of 40 to 80%. Manufacturing method.
<9> The method for producing a structural color body according to <7> or <8>, wherein the lead halide is lead (II) iodide.

  The structural color developing material of the present invention is extremely excellent in mechanical strength, chemical stability and thermal strength, and can maintain the structural color development for a long time. Moreover, since the raw material compound of the structural color developing body of the present invention is inexpensive, the manufacturing cost can be kept low.

2 is a photograph of a structural color developing body (blue) in Example 2. 6 is a photograph of a structural color developing body (green) of Example 6. 6 is a photograph of a structural color developing body (red) in Example 7. 6 is a photograph of a structural color developing body (gold color) of Example 8.

Hereinafter, the present invention will be described in detail.
The present invention is obtained by removing a solvent from a mixed solution formed by mixing a solution (A) containing iron (III) hydroxide colloid and a solution (B) containing lead halide, and then from the mixed solution. The structural color developing body thus obtained.

The structural color developing material of the present invention is characterized by mixing a solution (A) containing iron (III) hydroxide colloid and a solution (B) containing lead halide, evaporating the solvent, and drying. It is excellent in mechanical strength, chemical stability and thermal strength by a simple operation of removing the solvent of the mixed solution, and consists of various colors (blue, green, red, gold, or their intermediate colors) It is to be able to form a thin-film structural color developing body exhibiting a single structural color).
Although it is not completely clear at this stage that the structural color developing body capable of developing a remarkable structural color can be formed by such a simple operation, the solvent of the mixed solution (preferably a mixed solvent of alcohol and water) is used. In the process of evaporating gradually, the iron hydroxide (III) colloid self-assembles to form a regular structure, and it is assumed that lead halide contributes to improving the stability of the structure. Is done.
In addition, in order for the structural color developing body to color the structural color beautifully, the molar ratio of iron (III) hydroxide and lead halide contained in the mixed solution is in the range of 1.0 to 25. A range of 2.5 to 10 is particularly preferable.

In the solution (A) containing the iron (III) hydroxide colloid, the solvent of the solution (A) may be any solvent that can disperse the iron (III) hydroxide colloid, and specifically, water, methanol, or ethanol. The lower alcohols such as can be mentioned, and these may be used alone or in combination of two or more.
In particular, from the viewpoint of the stability of the iron (III) hydroxide colloid, the solvent of the solution (A) preferably contains water, and particularly preferably water.

The concentration of the iron (III) hydroxide colloid in the solution (A) is preferably in the range of 1 × 10 ⁻⁴ to 2 × 10 ⁻³ mol / L in terms of Fe atom, and 5 × 10 ⁻⁴ to It is particularly preferably 1 × 10 ⁻³ mol / L.
When the concentration is less than 1 × 10 ⁻⁴ mol / L, there is a problem that the color of the structural color becomes unclear. On the contrary, when the concentration exceeds 2 × 10 ⁻³ mol / L, the solvent removal described later is performed. When performing, there is a problem that the arrangement of the iron (III) hydroxide colloid is disturbed and it becomes difficult to exhibit structural coloring.

The method for forming the iron (III) hydroxide colloidal particles in the solution (A) is not particularly limited. However, when the hydrolysis reaction of iron (III) chloride is used, iron (III) chloride is added to boiling water. By adding this aqueous solution, a colloid of iron (III) hydroxide is formed according to the following reaction formula (1).

FeCl ₃ + 3H ₂ O → Fe (OH) ₃ + 3HCl (1)

Iron (III) hydroxide colloidal particles are inorganic polymer compounds that grow by dehydration condensation by covalently bonding tetracoordinate iron (Fe) atoms at two locations via oxygen (O) atoms. It is considered to be a multinuclear complex with a plate-like structure that becomes elongated as the number of the particles increases. The size of ordinary colloidal particles is 0.001 to 0.1 μm, but iron (III) hydroxide colloidal particles prepared by iron (III) chloride hydrolysis reaction include particles with a high degree of polymerization. Since this hinders structural color development, it is preferable to remove this with a filter or filter paper. A structural color is expressed from a filter or filter paper having a pore diameter or a retained particle diameter of 0.2 to 5 μm. In order to obtain a good structural color developing body having high brightness with good reproducibility, the retained particle diameter is particularly large. It is preferable to filter with 5 μm filter paper. As a filter paper, Advantech Toyo qualitative filter paper (No. 2) can be mentioned as a suitable specific example.
A beautiful blue structure color very similar to the color of Morpho butterfly wings can be expressed from an iron (III) hydroxide colloidal sol filtered with a 0.2 μm pore size filter. As a filter, 0.2 μm Supor Syringe Filters (Pall Pharm Assure HP1002, LOT.NO. 21441 2010-07) can be mentioned as a preferred specific example.

  Specific examples of the lead halide as the solute of the solution (B) containing lead halide include lead (II) fluoride, lead (II) chloride, lead (II) bromide, and lead (II) iodide. These may be used alone or in combination of two or more. Among these, lead (II) iodide is preferably contained, and only lead (II) iodide is particularly preferred in that a highly stable structural color developing body can be obtained.

  The solvent of the solution (B) may be any solvent that can dissolve lead halide and is compatible with the solvent of the solution (A). Specifically, water; methanol, ethanol, n-propanol, isopropanol The lower alcohols such as can be mentioned, and these may be used alone or in combination of two or more. Among these, ethanol is particularly preferable from the viewpoint of safety to the human body, and only ethanol is particularly preferable.

The suitable concentration of lead halide in the solution (B) depends on the concentration of the iron (III) hydroxide colloid in the solution (A) to be mixed. Specifically, the Pb atom equivalent concentration is preferably in the range of 1 × 10 ⁻⁵ to 2 × 10 ⁻⁴ mol / L, and preferably 5 × 10 ⁻⁵ to 1 × 10 ⁻⁴ mol / L. Is particularly preferred.
When the concentration of lead halide is less than 1 × 10 ⁻⁵ mol / L, the stabilizing effect is reduced from the iron (III) hydroxide colloid particles by lead halide, and the concentration exceeds 2 × 10 ⁻⁴ mol / L. On the other hand, the presence of lead halide inhibits the self-organization of iron (III) hydroxide colloidal particles, making it difficult to obtain a stable structural color developer.
The solution (B) may contain components other than lead halide as long as the object of the present invention is not impaired.

  As a method for producing the structural color developing material of the present invention, a case where water is used as the solvent of the solution (A), lead (II) iodide is used as the solute of the solution (B), and ethanol is used as the solvent will be specifically described. To do.

As a solution (A), a predetermined amount of iron chloride is added to a predetermined amount of boiling pure water and stirred for a predetermined time to form an aqueous solution of iron (III) hydroxide according to the above reaction formula (1). be able to. The obtained aqueous solution of iron (III) hydroxide (solution (A)) can be purified and used by means such as filtration or ion exchange, if necessary.
As described above, from the viewpoint of obtaining a thin film-like structural color developing body, a suitable concentration of iron (III) hydroxide is 5 × 10 ⁻⁴ to 1 × 10 ⁻³ mol in terms of Fe atom. / L.

As a solute of the solution (B), lead (II) iodide to be used can be produced by a conventionally known method. For example, lead oxide (I) is heated in the presence of methyl iodide, lead acetate, (II) A method in which an aqueous solution and an aqueous potassium iodide solution are mixed and precipitated.
In addition, since the structural color developing body can be produced with good reproducibility, it is preferable to recrystallize and use lead (II) iodide.
Ethanol used as a solvent for the solution (B) has a high compatibility with water, and its lead (II) iodide has a saturated concentration of about 8.0 × 10 ⁻⁵ mol / L, and has a thin-film structure. This is preferable because a dilute lead (II) iodide solution suitable for forming a color developing body can be obtained.

The mixing ratio of the solution (A) and the solution (B) may be appropriately determined according to the purpose and application, and is arbitrary depending on the concentration of iron hydroxide (III) or lead (II) iodide in each solution. However, from the viewpoint that the solution can be rapidly and uniformly mixed, the volume ratio of the solution (A) to the solution (B) is preferably 3: 7 to 7: 3.
The method for mixing the solution (A) and the solution (B) is not particularly limited, and the mixing temperature is not particularly limited, but the conditions under which the dissolved lead halide does not precipitate are selected. It is.
In addition, in the step of evaporating and removing the solvent, in addition to the solution (A) and the solution (B), if necessary, ethanol or water, which are the respective solvents, is further added, and a structural color developing body is formed. The color can be changed.

  The structural color developing body of the present invention can be obtained by evaporating and removing the solvent from the mixed solution obtained by mixing the solution (A) and the solution (B). As a method of evaporating and removing the solvent and drying, any method such as natural drying, heat drying, and vacuum drying may be used. However, in order to obtain a structural color developing body having a highly uniform structure, rapid Since natural evaporation of the solvent is not preferred, natural drying is preferred. Suitable drying conditions include a temperature of 20 to 35 ° C. (more preferably 25 to 32 ° C.) and a relative humidity of 40 to 80% (more preferably 55 to 70%). .

The structural color developing body of the present invention can itself be used as a self-supporting film, but a mixed solution obtained by mixing the solution (A) and the solution (B) is applied to various substrates, and the substrate It is often formed on the material surface.
The substrate is not particularly limited, and an inorganic substrate such as glass or plastic can be selected by appropriately selecting a solvent to be used according to the properties of the substrate surface (hydrophilic or hydrophobic, unevenness, etc.). It can be used for any organic base material such as.
The structural color developing body of the present invention can be suitably used for transparent glass and ceramics, particularly from the viewpoint of its design properties, and is also suitable for a substrate made of resin because it does not require a heating step. Can be used.
Moreover, the coating method to a base material is not specifically limited, It can carry out by a conventionally well-known coating method. That is, brush coating, bar coater coating, sponge coating, spray coating, and the like.

  The curing time of the structural color body applied to the substrate varies depending on the solute concentration of each of the solution (A) and the solution (B), the mixing ratio thereof, the coating amount, the solvent evaporation method, etc. The structural color developing body having sufficient hardness can be obtained by evaporating and removing (drying) the solvent in about 1 day.

  Even if the structural color developing body of the present invention is left in the air under various illuminations for a long period (several months or more), the brightness of the structural color is not impaired. In addition, this structural coloring thin film does not dissolve in water at all, and has high durability against acidic solutions such as hydrochloric acid and nitric acid, alkaline solutions such as sodium hydroxide and potassium hydroxide, and organic solvents such as benzene and toluene. Even if immersed in these solutions (solvents), there is almost no change.

The structural color developing body of the present invention exhibits a single structural color consisting of blue, green, red, gold, or an intermediate color thereof. The structural color of the structural color developing body depends on the raw material composition, the thickness of the structural color developing body, and the like. Although the thickness of the structural color developing body can be arbitrarily adjusted, it is preferably 1 to 20 μm in order to obtain a continuous film having no defects.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these.

The reagents and evaluation equipment used are shown below.
Iron (III) chloride hexahydrate (Kanto Chemical Co., Ltd. reagent special grade, 99.0%)
Potassium iodide (Kanto Chemical Co., Ltd. reagent grade, 99.5%)
Potassium fluoride dihydrate (Kanto Chemical Co., Ltd. reagent grade, 98.0%)
Potassium chloride (Kanto Chemical Co., Ltd. reagent special grade, 99.5%)
Potassium bromide (Kanto Chemical Co., Ltd. reagent special grade, 99.0%)
Lead (II) acetate trihydrate (Kanto Chemical Co., Ltd. reagent grade, 99.5%)
Ethanol (Kanto Chemical Co., Ltd. reagent grade, 99.5%)
Methanol (Kanto Chemical Co., Ltd. reagent grade, 99.8%)

“Preparation of solution (A) containing iron (III) hydroxide colloid”
About 1000 mL of pure water is taken into a beaker, and 50 mL of a newly prepared 20 wt% aqueous solution of iron (III) chloride is added to the beaker while stirring with a glass rod, and an aqueous solution containing iron (III) hydroxide colloid (hereinafter referred to as solution ( A)) was prepared.
The concentration of the aqueous solution of iron (III) colloid in the obtained solution (A) was 8.0 × 10 ⁻⁴ mol / L.
Further, the obtained solution (A) was filtered through the following filter paper 1, filter paper 2, filter paper 3, and filter paper (filter) 4 to obtain solutions (A1), solution (A2), solution (A3), It was set as the solution (A4).

Filter paper 1: No. 2 filter paper (retained particle size: 5μm Advantech Toyo qualitative filter paper)
Filter paper 2: No. 131 filter paper (retained particle size: 3μm Advantech Toyo qualitative filter paper)
Filter paper 3: Glass fiber filter paper GS-25 (Retained particle size: 0.6 μm Advantech Toyo Analytical filter paper)
Filter paper (filter) 4: Syringe filter (pore size: 0.2 μm) Pall PharmAssure
(HP1002, LOT.NO. 21441 2010-07)

“Preparation of solution (B1) containing lead halide (saturated lead (II) iodide ethanol solution)”
In a 200 mL beaker, 50 mL of pure water was added, 6.0 g of lead (II) acetate was added thereto, and the mixture was thoroughly stirred with a glass rod to dissolve it, thereby preparing a lead (II) acetate solution.
Into a 100 mL beaker, 50 mL of pure water was added, 6.0 g of potassium iodide was added thereto, and the mixture was thoroughly stirred with a glass rod to dissolve, thereby preparing a potassium iodide solution.
The yellow precipitate produced when this potassium iodide solution and lead (II) acetate solution were mixed was filtered with a suction filtration device, and the powder on the filter paper was washed with pure water. The obtained powder was purified by recrystallization to produce lead (II) iodide.
About 2 g of the obtained lead (II) iodide powder was placed in 300 mL of ethanol (Kanto Chemical Co., Ltd. reagent grade, 99.5%), stirred for 2 days with a magnetic stirrer, allowed to stand for 6 hours, and then filtered (Advantech). By filtering through Toyo qualitative filter paper, No. 2), a solution (B1) in which lead (II) iodide was saturatedly dissolved in an ethanol solvent was obtained.
The color of the solution (B1) is light yellow. As a result of measuring the amount of lead (II) iodide dissolved from the change in weight when a certain amount of the solution (B1) was completely evaporated, the concentration was 8. It was found to be 0 × 10 ⁻⁵ mol / L.

“Preparation of solution containing lead halide (B2) (saturated lead fluoride (II) ethanol solution)”
A solution (B2) in which lead fluoride (II) was saturatedly dissolved in an ethanol solvent was carried out in the same manner as lead (II) iodide, except that 2.14 g of potassium fluoride was used instead of 6.0 g of potassium iodide. )
The color of the solution (B2) is colorless. As a result of measuring the amount of lead (II) dissolved from the change in weight when a certain amount of the solution (B2) is completely evaporated, the concentration is 2.78. It was found to be × 10 ⁻³ mol / L.

“Preparation of solution containing lead halide (B3) (saturated lead (II) chloride ethanol solution)”
Except for using 2.75 g of potassium chloride instead of 6.0 g of potassium iodide, the same operation as the above lead (II) iodide was performed, and a solution (B3) in which lead (II) chloride was dissolved in an ethanol solvent in a saturated manner was obtained. Obtained.
The color of the solution (B3) is colorless. As a result of measuring the amount of lead (II) dissolved from the change in weight when a certain amount of the solution (B3) was completely evaporated, the concentration was 4.67 ×. It was found to be 10 ⁻⁵ mol / L.

“Preparation of solution containing lead halide (B4) (saturated lead (II) bromide ethanol solution)”
A solution (B4) in which lead bromide (II) was saturatedly dissolved in an ethanol solvent was carried out in the same manner as lead (II) iodide, except that 4.39 g of potassium bromide was used instead of 6.0 g of potassium iodide. )
The color of the solution (B4) is colorless. As a result of measuring the amount of lead (II) bromide dissolved from the change in weight when a certain amount of the solution (B4) was completely evaporated, the concentration was 9.73. It was found to be × 10 ⁻⁴ mol / L.

Example 1
In an environment with a room temperature of 28 ° C. and a relative humidity of 55%, drop 1 drop (1 drop is about 0.05 mL) of solution (A) into a 50 mL beaker (manufactured by IWAKI Glass Co., Ltd.), then 4 drops of ethanol. Is dripped, shaken and mixed well, and evenly applied to the bottom of the beaker. About 5 minutes later, finally, 4 drops of the solution (B1) was added and mixed well, and the mixture was allowed to stand for about 1 day to form the structural color developer of Example 1 on the bottom of the beaker. The structural color body of Example 1 exhibited a blue structural color.

(Example 2)
The structural color body of Example 2 was formed in the same manner as in Example 1 except that the solution (A1) was used instead of the solution (A). The structural color developer of Example 2 exhibited a particularly beautiful blue structural color (FIG. 1).

(Example 3)
The structural color body of Example 3 was formed in the same manner as in Example 1 except that the solution (A2) was used instead of the solution (A). The structural color developing material of Example 3 was blue but exhibited a blue structural color.

Example 4
The structural color body of Example 4 was formed in the same manner as in Example 1 except that the solution (A3) was used instead of the solution (A). The structural color developing body of Example 4 was blue but exhibited a blue structural color.

(Example 5)
The structural color body of Example 4 was formed in the same manner as in Example 1 except that the solution (A4) was used instead of the solution (A). The structural color developing body of Example 4 exhibited a beautiful blue structural color with high luminance very similar to the color of the morpho butterfly wing.

(Example 6)
In an environment with a room temperature of 28 ° C. and a relative humidity of 55%, drop 3 drops of the solution (A1) into a 50 mL beaker (manufactured by IWAKI Glass Co., Ltd.) with a dropper (1 drop is about 0.05 mL) and add the solution (B1). When 3 drops were added and mixed well, and the mixture was allowed to stand for about 1 day, the structural color developer of Example 6 was formed at the bottom of the beaker. The structural color developer of Example 6 exhibited a beautiful green structural color (FIG. 2).

(Example 7)
In an environment with a room temperature of 28 ° C. and a relative humidity of 55%, drop 2 drops (1 drop is about 0.05 mL) of the solution (A1) into a 50 mL beaker (manufactured by IWAKI Glass Co., Ltd.), and 1 drop of ethanol. Was added dropwise and shaken and mixed. Finally, 3 drops of the solution (B1) was added and mixed well. When the mixture was allowed to stand for about 1 day, the structural color developer of Example 7 was formed at the bottom of the beaker. The structural color developing body of Example 7 exhibited a beautiful red structural color (FIG. 3).

(Example 8)
The structural color developer of Example 8 was formed in the same manner as in Example 7 except that the same amount of water was used instead of ethanol. The structural color body of Example 8 exhibited a particularly beautiful golden structural color (FIG. 4).

Example 9
The structural color body of Example 9 was formed in the same manner as Example 2 except that the solution (B2) containing the same amount of lead fluoride was used instead of lead iodide. The structural color developer of Example 9 was not clear in color compared to Example 2 which had a blue structural color.

(Example 10)
A structural color body of Example 10 was formed in the same manner as in Example 6 except that the solution (B2) containing the same amount of lead fluoride was used instead of lead iodide. The structural color developing body of Example 10 was not clear in color compared to Example 6 which exhibited a green structural color.

(Example 11)
A structural color body of Example 11 was formed in the same manner as Example 7 except that the solution (B2) containing the same amount of lead fluoride was used instead of lead iodide. The structural color developer of Example 11 was not clear in color compared to Example 7 which exhibited a green structural color.

(Example 12)
The structural color body of Example 11 was formed in the same manner as Example 8 except that the solution (B2) containing the same amount of lead fluoride was used instead of lead iodide. The structural color developer of Example 11 was not clear in color compared to Example 8 which exhibited a green structural color.

(Example 13)
A structural color body of Example 9 was formed in the same manner as in Example 2 except that the solution (B3) containing the same amount of lead chloride was used instead of lead iodide. The structural color developer of Example 13 was not clear in color compared to Example 2 which had a blue structural color.

(Example 14)
The structural color body of Example 14 was formed in the same manner as in Example 6 except that the solution (B3) containing the same amount of lead chloride was used instead of lead iodide. The structural color developer of Example 14 was not vivid in color compared to Example 6 which exhibited a green structural color.

(Example 15)
The structural color body of Example 15 was formed in the same manner as Example 7 except that the solution (B3) containing the same amount of lead chloride was used instead of lead iodide. The structural color developer of Example 15 was not clear in color as compared to Example 7 which exhibited a green structural color.

(Example 16)
The structural color body of Example 16 was formed in the same manner as in Example 8 except that the solution (B3) containing the same amount of lead chloride was used instead of lead iodide. The structural color developing body of Example 16 was not clear in color compared to Example 8 which exhibited a green structural color.

(Example 17)
The structural color body of Example 17 was formed in the same manner as in Example 2 except that the solution (B4) containing the same amount of lead bromide was used instead of lead iodide. The structural color developer of Example 17 was not vivid in color compared to Example 2 which had a blue structural color.

(Example 18)
The structural color body of Example 18 was formed in the same manner as in Example 6 except that the solution (B4) containing the same amount of lead bromide was used instead of lead iodide. The structural color developer of Example 18 was not clear in color compared to Example 6 which had a green structural color.

(Example 19)
The structural color body of Example 19 was formed in the same manner as in Example 7 except that the solution (B4) containing the same amount of lead bromide was used instead of lead iodide. The structural color developer of Example 19 was not clear in color as compared to Example 7 which exhibited a green structural color.

(Example 20)
The structural color body of Example 20 was formed in the same manner as in Example 8 except that the solution (B4) containing the same amount of lead bromide was used instead of lead iodide. The structural color developer of Example 20 was not vivid in color compared to Example 8 which had a green structural color.

(Comparative Example 1)
An attempt was made to produce a structural color body in the same process as in Example 2 except that the same amount of lead acetate was used instead of lead halide, but the thin film formed on the bottom of the beaker did not exhibit a structural color. .

(Comparative Example 2)
An attempt was made to produce a structural color body in the same process as in Example 6 except that the same amount of lead acetate was used instead of lead halide, but the thin film formed on the bottom of the beaker did not exhibit a structural color. .

(Comparative Example 3)
An attempt was made to produce a structural color body in the same process as in Example 7 except that the same amount of lead acetate was used instead of lead halide, but the thin film formed on the bottom of the beaker did not exhibit a structural color. .

(Comparative Example 4)
An attempt was made to produce a structural color body in the same process as in Example 8 except that the same amount of lead acetate was used instead of lead halide, but the thin film formed on the bottom of the beaker did not exhibit a structural color. .

(Example 21)
A similar experiment was performed by changing the preparation container of the structural color developing body from a 50 mL beaker to a 100 mL beaker (manufactured by IWAKI Glass Co., Ltd.). In addition, since the diameter of the bottom face of a 50 mL and 100 mL beaker is 4.0 cm and 5.0 cm, respectively, the area ratio of a beaker bottom face is 1: 1.56.
In order to make the film thickness of the thin film (structural color developing body) equal in the 50 mL beaker and the 100 mL beaker, in the case of the 100 mL beaker, the amount of liquid dropped is about 1.6 times that in the case of the 50 mL beaker. 2. An attempt was made to produce a structural color developing body in the same steps as in Example 6, Example 7, and Example 8. As a result, structural color developing bodies having beautiful structural colors of blue, green, red, and gold were obtained. It was.

(Example 22)
An attempt was made to produce a structural color body in the same steps as in Example 2, Example 6, Example 7, and Example 8 except that the production surface of the thin film (structural color body) was changed from glass to ceramic. Structural color development bodies having beautiful structural colors of blue, green, red, and gold, respectively, were obtained.
The surface of the earthenware with a structural color developer on the surface was heated for 1 hour at the highest temperature of the flame of the gas burner (about 1800 ° C), and then the surface was observed. Was not.
Furthermore, the ceramics on which this structural color developing body was formed were immersed in liquid nitrogen (-196 ° C.), pulled up after 8 hours, and the surface was observed, but no change was confirmed in the structural color developing body. It was.

  According to the present invention, it is possible to easily produce a structural color developing body that exhibits a beautiful structural color that could only be seen with an iridescent shell, a morpho butterfly wing, or a bird wing. Moreover, since the raw material compound for the structural color developing body of the present invention is inexpensive, the manufacturing cost can be kept extremely low. Furthermore, by using the structural color developing material obtained in the present invention for paints, inks, paints, fibers, cosmetics, and plastics, it is possible to produce those products that develop various structural colors. Very promising.

Claims (9)

  It is obtained by mixing a solution (A) containing iron (III) hydroxide colloid and a solution (B) containing lead halide to form a mixed solution, and then removing the solvent from the mixed solution A structural color developer characterized by   The structural color developing body according to claim 1, wherein the molar ratio of iron (III) hydroxide and lead halide contained in the mixed solution is in the range of 1.0 to 25.   The structural color developing body according to claim 1 or 2, wherein the solvent of the solution (A) is water and the solvent of the solution (B) is ethanol.   4. The structural color development according to claim 3, wherein the solvent of the mixed solution is removed by evaporating the solvent at a temperature of 20 to 35 [deg.] C. and a relative humidity of 40 to 80%, followed by drying. body.   The structural color developing body according to any one of claims 1 to 4, wherein the lead halide is lead (II) iodide.   The structural color developing body according to any one of claims 1 to 5, wherein the solution (A) is mixed with the solution (B) after being previously filtered through a filter or filter paper having a pore size or a retained particle size of 0.2 to 5 µm. .   A step of mixing an aqueous solution (A) containing iron (III) hydroxide colloid with an ethanol solution (B) containing lead halide to form a mixed solution, and a step of evaporating the solvent from the mixed solution and drying it. And a method for producing a structural color developing body.   8. The structural color development according to claim 7, wherein the solvent of the mixed solution is removed by evaporating and drying the solvent under conditions of a temperature of 20 to 35 ° C. and a relative humidity of 40 to 80%. Body manufacturing method.   The method for producing a structural color developing body according to claim 7 or 8, wherein the lead halide is lead (II) iodide.