JP4748735B2 - COLORING STRUCTURE, PROCESS FOR PRODUCING THE SAME, AND ELECTRIC PRODUCT HAVING THE COLORING STRUCTURE - Google Patents

Description

  The present invention relates to a coloring structure, a method for producing the same, and an electrical product having the coloring structure.

  Usually, coloring is performed using a paint (pigment). This paint contains volatile organic substances and may adversely affect the environment. In addition, since the mechanical strength of the paint is low, problems such as easy scratching and peeling occur, and problems such as deterioration of appearance due to discoloration due to chemical changes have occurred.

  On the other hand, the coloration seen in morpho butterflies and beetles is the coloration due to light interference, diffraction and scattering based on the fine structure. If coloring is performed using such a coloring mechanism, coloring can be done without using paint. It is possible to solve the above-mentioned problems caused by using the paint.

  Here, as an example using the color development mechanism, a structure 100 including a metal layer 101 and an anodized layer 103 in which a plurality of nanoholes 102 are formed as shown in FIG. 16 can be considered. In this structure 100, the intensity of the reflected light A transmitted through the anodized layer 103 and reflected by the surface 101a of the metal layer 101 is higher than the intensity of the reflected light B reflected by the outer surface 103a of the anodized layer 103. Therefore, the interference between the reflected light A and the reflected light B is not emphasized, and the color contrast (saturation) cannot be improved (a clear color can be visually recognized).

  Further, as an example using the coloring mechanism, as shown in FIG. 17, a metal substrate 111 capable of forming a transparent anodized film, a barrier layer 112 formed on the surface thereof, and an outer surface 112a of the barrier layer 112 An interference color metal body 110 including a light reflective layer 113 formed thereon is disclosed (see Patent Document 1). In this interference color-developing metal body 110, by forming the light reflective layer 113 on the outer surface 112a of the barrier layer 112, the intensity of the reflected light B reflected by the light reflective layer 113 is improved and the metal substrate is formed. Since the intensity of the reflected light A reflected on the surface 111a of the 111 is weakened, the interference between the reflected light A reflected on the surface 111a of the metal substrate 111 and the reflected light B can be emphasized, and the color contrast (saturation) ) Can be improved.

  However, if the light reflective layer 113 formed on the outer surface 112a of the barrier layer 112 is scratched or the light reflective layer 113 formed on the outer surface 112a is peeled, the light reflective layer 113 The intensity of the reflected light B reflected is improved and the intensity of the reflected light A reflected on the surface 111a of the metal substrate 111 cannot be reduced, and the reflected light A and the light reflected from the surface 111a of the metal substrate 111 are reflected. There is a problem that the interference with the reflected light B reflected by the luminescent layer 113 cannot be enhanced, and the color contrast (saturation) cannot be improved.

  Patent Document 2 discloses a nanohole structure in which a carbon layer is deposited inside a nanohole formed in a direction substantially orthogonal to the metal layer surface. This nanohole structure is a carbon nanotube composite material. It is obtained in the process of manufacturing and is not used as a coloring structure. That is, the present invention is novel in that the nanohole structure is used as the color developing structure.

Japanese Patent Laid-Open No. 2002-36372 JP 2005-350339 A

  An object of the present invention is to solve the conventional problems and achieve the following objects. That is, a color developing structure that can enhance the interference between the light reflected on the surface of the light reflecting layer and the light reflected on the outer surface of the light transmitting layer, thereby improving the color contrast (saturation). It is an object of the present invention to provide a body, a method for producing the same, and an electrical appliance having the coloring structure.

Means for solving the problems are as follows. That is,
The color developing structure of the present invention is formed on at least the inner surface of the nanohole among the light reflecting layer, the light transmitting layer formed on the light reflecting layer and having nanoholes formed thereon, and the exposed surface of the light transmitting layer. And a light absorption layer.

  In the coloring structure, incident light is transmitted through the light transmission layer and totally reflected on the surface of the light reflection layer, and is reflected on the outer surface of the light transmission layer. At this time, the light absorption layer formed on the inner surface of the nanohole in the light transmission layer absorbs (attenuates) light transmitted through the light transmission layer. As a result, compared with the case where the light absorption layer is not formed on the inner surface of the nanohole, the light transmitted through the light transmission layer and totally reflected on the surface of the light reflection layer is reflected on the outer surface of the light transmission layer. Significantly emphasize the interference with the emitted light. Further, when the interference light is visible light, the coloring structure appears to be colored even if no paint (pigment) is applied to the coloring structure.

  Furthermore, even if an external force is applied, the light absorption layer formed on the outer surface of the light transmission layer is damaged, or the light absorption layer formed on the outer surface of the light transmission layer is peeled off, Since the light absorption layer formed on the inner surface of the nanohole remains, the light transmitted through the light transmission layer is absorbed (attenuated), and the light reflected on the surface of the light reflection layer and the outside of the light transmission layer are absorbed. It maintains strong interference with the light reflected on the surface and does not suffer damage such as deterioration in color contrast (saturation).

  The method for producing a coloring structure according to the present invention includes a light transmitting layer forming step of forming a light transmitting layer in which nanoholes are formed on a light reflecting layer by anodizing a metal substrate, and light absorption on the inner surface of the nanohole. And a light absorption layer forming step of forming a layer.

  In the method for producing the color developing structure, in the light transmission layer forming step, the metal substrate is anodized to form the light transmission layer in which nanoholes are formed on the light reflection layer. In the process, a light absorption layer is formed on the inner surface of the nanohole. As a result, the colored structure can be obtained efficiently.

  According to the present invention, the conventional problems can be solved, and the light transmitted through the light transmission layer is absorbed (attenuated) and reflected by the surface of the light reflection layer and reflected by the outer surface of the light transmission layer. Thus, it is possible to provide a color-forming structure that can enhance interference with light and improve color contrast (saturation), a method for producing the same, and an electrical appliance having the color-forming structure.

(Coloring structure)
The color developing structure of the present invention is formed on at least the inner surface of the nanohole among the light reflecting layer, the light transmitting layer formed on the light reflecting layer and having nanoholes formed thereon, and the exposed surface of the light transmitting layer. And other members (layers) appropriately selected as necessary.

As shown in FIGS. 1A and 1B, the color developing structure of the present invention includes a light reflecting layer 11, a light transmitting layer 13 formed on the light reflecting layer 11, in which nanoholes 12 are formed, and a light transmitting layer 13. It has a light absorption layer 14 formed on at least the inner surface of the nanohole 12 in the exposed surface, and further has other members (layers) appropriately selected as necessary.
Here, in FIG. 1A, the light absorption layer 14 is formed on the entire exposed surface (the inner surface of the nanohole 12 and the outer surface 13a of the light transmission layer 13), but the present invention is not limited to this. As shown, it may be formed only on the inner surface of the nanohole 12.

-Light reflection layer-
The light reflecting layer 11 is not particularly limited as long as it reflects light, and examples of the material that reflects light include a metal layer. The metal layer may be, for example, any of a simple metal, an alloy, and the like. Among these, for example, aluminum, magnesium, a magnesium alloy, and the like are preferable. Among these, aluminum is particularly preferable.
As will be described later, when the metal substrate is anodized, the remaining metal portion without being anodized becomes the light reflecting layer 11.

-Light transmission layer-
The light transmitting layer 13 is not particularly limited as long as a plurality of nanoholes 12 are formed and transmits light, and the thickness, shape, structure, size, and the like can be appropriately selected according to the purpose.

  There is no restriction | limiting in particular as thickness of the light transmissive layer 13, Although it can select suitably according to the objective, For example, 100-800 nm is preferable and 100-600 nm is especially preferable. If the thickness of the light transmission layer 13 is smaller than 100 nm, there is a problem that interference in the visible light region is reduced and the color disappears. If the thickness of the light transmission layer 13 is larger than 800 nm, the length of the light absorption layer 14 is increased. There is a problem that the absorption capacity is increased, and as a result, most of the light is absorbed. The color tone can be adjusted by adjusting the thickness of the light transmission layer 13. When the light transmission layer 13 is thick, the color tone indicates red, and when the light transmission layer 13 is thin, the color tone indicates blue.

  There is no restriction | limiting in particular as said shape, Although it can select suitably according to the objective, For example, plate shape, disk shape (disk shape), etc. are mentioned suitably.

  In addition, when the said shape is plate shape, disk shape, etc., the nanohole (pore) 12 is formed in the direction substantially orthogonal to the surface 11a of the light reflection layer 11. The nanoholes 12 may be formed as holes through the light transmission layer 13 or may be formed as holes (dents) without penetrating the light transmission layer 13.

  There is no restriction | limiting in particular as said structure, According to the objective, it can select suitably, A single layer structure may be sufficient and a laminated structure may be sufficient.

  There is no restriction | limiting in particular as said magnitude | size, According to the objective, it can select suitably.

-Light absorption layer-
The light absorption layer 14 is not particularly limited as long as it is formed on at least the inner surface of the nanohole 12 in the exposed surface of the light transmission layer 13 and absorbs (attenuates) light. For example, it is a carbon layer. It is also preferable that it has a layered structure. The thickness of the light absorption layer 14 is preferably 2 to 20 nm.
If the thickness of the light absorption layer is less than 2 nm, there is a problem that the absorption capacity is lowered. If the thickness of the light absorption layer is more than 20 nm, the absorption capacity is too high to absorb most light. is there.
By making the light absorption layer 14 thick, the light transmitted through the light transmission layer 13 can be more absorbed (attenuated), and the color contrast (saturation) can be improved. The light absorption layer 14 may be formed not only on the inner surface of the nanohole 12 but also on the outer surface 13 a of the light transmission layer 13.

―Other layers―
There is no restriction | limiting in particular as said other layer, According to the objective, it can select suitably.

  In the coloring structure 10 of the present invention, the light absorption layer 14 absorbs (attenuates) the light A transmitted through the light transmission layer 13, and the light A reflected by the surface 11a of the light reflection layer 11 and the light transmission layer. The interference with the light B reflected on the outer surface 13a of the 13 can be emphasized, so that the color contrast (saturation) can be improved.

  Furthermore, even if an external force is applied, the light absorption layer 14 formed on the outer surface 13a of the light transmission layer 13 is damaged, or the light absorption layer 14 formed on the outer surface 13a of the light transmission layer 13 is peeled off. However, since the light absorption layer 14 remains on the inner surface of the nanohole 12, the light A transmitted through the light transmission layer 13 is absorbed (attenuated) and reflected on the surface 11a of the light reflection layer 11. The strong interference between the light A and the light B reflected on the outer surface 13a of the light transmission layer 13 is maintained, and no damage such as deterioration in color contrast (saturation) occurs.

  Even the structure (FIG. 16) composed of only the light reflection layer 11 and the light transmission layer 13 in which the light absorption layer 14 is not formed produces a slight color, but the color contrast (saturation) is low and the color development. It does not function as a structure. Therefore, by adding the light absorption layer 14 made of a carbon layer or the like, the color saturation is improved as shown in FIG. Further, when the light absorption layer 14 is a carbon layer, since the carbon has a high hardness, the mechanical strength of the coloring structure can be improved.

  In addition, the color development structure shown in FIG. 5 has different colors in the regions A to G. This color difference is caused by a difference in the thickness of the light transmission layer 13, that is, in an anodic oxidation treatment time. As shown in FIG. 6, region H is first processed for t1 seconds (for example, 32 seconds), region I is processed for t2 seconds (for example, 57 seconds), and region J is further processed for t3 seconds (for example, 82 seconds). By processing, the region K is processed for t1 seconds, the region L is processed for t2 seconds, the region M is processed for t3 seconds, the region N is processed for t1 + t2 seconds, the region O is processed for t2 + t3 seconds, and the region P is processed for t1 + t3 seconds. As a result, the region Q is processed for t1 + t2 + t3 seconds, and a difference in the processing time of the anodic oxidation can be obtained. As a result, the thickness of the light transmission layer 13 can be varied, and as a result, a difference in color can be produced.

  Moreover, if the anodizing time is continuously changed, the color can be continuously changed, and for example, a rainbow-like color can be expressed. Specifically, as shown in FIG. 7, a method of gradually lifting the aluminum substrate from the electrolytic bath while anodizing the aluminum substrate is conceivable. Then, the color which changes continuously is obtained by providing the light absorption layer 14.

  The production of the coloring structure of the present invention is not particularly limited, and can be produced according to a known method, but can be suitably produced by the production method of the coloring structure of the present invention described below.

(Method for producing colored structure)
The method for producing a color forming structure of the present invention includes at least a light transmitting layer forming step and a light absorbing layer forming step, and further includes other steps appropriately selected as necessary.

<Light transmission layer forming step>
The light transmission layer forming step is a step of forming a light transmission layer in which nanoholes are formed on the light reflection layer by anodizing the metal substrate.

-Metal substrate-
The metal substrate is not particularly limited as long as it is formed using a metal material. The metal material may be any of a simple metal, an alloy, etc. Among these, for example, aluminum, Magnesium, a magnesium alloy, etc. are mentioned suitably, Among these, aluminum is especially preferable.

The method for smoothing the surface of the metal substrate (smoothing treatment) is not particularly limited and may be appropriately selected depending on the intended purpose. Preferred examples include electropolishing.
The metal substrate has streaks due to rolling in the substrate manufacturing process, and the substrate surface is often rough and uneven. Therefore, a smooth surface can be obtained by performing a smoothing process such as electrolytic polishing.
The electrolytic polishing can be performed using, for example, an electrolytic polishing apparatus as shown in FIG.

-Anodizing treatment-
A light transmission layer (porous layer) having innumerable nanoholes is produced by anodizing the metal substrate. For example, as shown in FIG. 3, anodization is performed by placing a metal substrate masked on one side with an insulating tape as an anode and a metal substrate of the same size masked on one side as a cathode, and placing it in a cell. It can be performed.

  There is no restriction | limiting in particular as a voltage in the said anodizing process, According to the objective, it can select suitably.

  The type, concentration, temperature, time, etc. of the electrolytic solution in the anodizing treatment are not particularly limited and are appropriately selected according to the thickness of the light transmission layer to be formed, the number, size, aspect ratio, etc. of the nanoholes. be able to. The thickness of the light transmission layer can be adjusted by increasing or decreasing the anodizing time. The aspect ratio of the nanoholes can be adjusted by increasing the diameter of the nanoholes (alumina pores) by immersing them in a phosphoric acid solution after the anodizing treatment.

  Through the above steps, a light transmission layer (porous layer) in which a plurality of nanoholes are formed is formed.

<Light absorption layer formation process>
The light absorbing layer forming step is a step of forming a light absorbing layer on the inner surface of the nanohole. For example, a source gas is supplied into the nanohole, and a light absorption layer is formed on the inner surface of the nanohole by chemical vapor deposition.

-Source gas-
The source gas is not particularly limited as long as it is deposited on the inner surface of the nanohole by a chemical vapor deposition method (CVD method), and can be appropriately selected according to the purpose. It is preferable to use a mixed gas with the introduction gas.
As the carbon supply gas, for example, at least one hydrocarbon selected from the group consisting of methane, ethane, propane, acetylene, ethylene, propylene, and benzene is preferable.
Examples of the introduced gas include nitrogen, argon, hydrogen, NH _{3 and the} like, and nitrogen gas is preferable.
In this case, the mixing ratio in the mixed gas is not particularly limited and can be appropriately selected depending on the purpose. For example, when acetylene gas is used as the carbon supply gas and nitrogen gas is used as the introduction gas Is preferably about acetylene gas: nitrogen gas = 10-30: 90-70 by volume ratio at normal pressure, and particularly preferably acetylene gas: nitrogen gas = 20: 80.

-Chemical vapor deposition (CVD)-
Examples of the chemical vapor deposition method (CVD method) include thermal CVD (also simply referred to as CVD), hot filament CVD, plasma enhanced CVD (also referred to as plasma assisted CVD and plasma CVD), plasma enhanced hot filament CVD, Laser enhanced CVD (also called laser CVD), and the like can be given. Among these, thermal CVD and plasma CVD are preferable.

In the thermal CVD, carbon is deposited by heating to about 400 to 2,000 ° C.
In the plasma CVD, carbon is deposited by decomposing a source gas with plasma excited at a high frequency (RF) of about 0.1 to 1,000 W / cm ³ . In addition to plasma excited by the high frequency (RF), plasma excited by low frequency, microwave (MW), direct current (DC), or the like can be used.
In the chemical vapor deposition method (CVD method), for example, as shown in FIG. 4, an anodized metal substrate is placed on a quartz boat so that the anodized surface faces up, and the soaking zone in the center of the reaction tube is placed. It can be done by putting in. Here, the film formation of the source gas is performed under atmospheric pressure and at a temperature of 400 to 1000 ° C., preferably 600 to 800 ° C.

  In the light absorption layer forming step, when the carbon layer is formed by the CVD method or the like, the material of the light transmission layer acts as a catalyst for forming the carbon layer. It is not necessary to use it separately. For example, when the light transmission layer is made of alumina, the alumina present on the exposed surface of the light transmission layer acts as a catalyst for forming the carbon layer as it is.

  There is no restriction | limiting in particular as said catalyst, Although it can select suitably according to the objective, For example, a transition metal is mentioned suitably. Examples of the transition metal include Fe, Ni, Co, Ru, Rh, Pd, Pt, La, Ce, Pr, Nd, Gd, Tb, Dy, Ho, Er, Lu, and alloys containing these metal elements. Is mentioned.

  Before performing the light absorption layer forming step, the exposed surface of the light transmission layer may be cleaned, and the cleaning method includes discharge such as solvent cleaning, corona treatment, plasma treatment, plasma ashing, and the like. Processing, etc.

<Other processes>
There is no restriction | limiting in particular as said other process, According to the objective, it can select suitably, For example, a washing | cleaning process, a drying process, etc. are mentioned.

(Electrical products)
Examples of the electric appliance include a personal computer and a mobile phone.

<Personal computer>
The personal computer is not particularly limited as long as it has a color developing structure as a casing, and can be appropriately selected according to the purpose.

<Mobile phone>
The mobile phone is not particularly limited as long as it has a color developing structure as a casing, and can be appropriately selected according to the purpose.

  Examples of the present invention will be described below, but the present invention is not limited to the following examples.

Example 1
<Manufacture of coloring structure>
As shown in FIG. 8, an aluminum substrate was electropolished, the electropolished aluminum substrate was anodized, and carbon was deposited on the anodized aluminum substrate to produce a color structure.

-Electropolishing-
The aluminum substrate used as the starting material (Furuuchi Chemistry, for substrates, purity 99.99%, 0.5 × 100 × 300 (mm)) contains streaks due to rolling in the substrate manufacturing process, and the substrate surface is rough. Since it was uniform, electropolishing was performed to obtain a smooth surface.

  Table 1 shows the experimental conditions for electrolytic polishing. An insulating tape was attached to one side of the Al plate cut to 0.5 × 50 × 50 (mm). This was used as the anode and the Ni plate cut to the same size (Furuuchi Chemistry, purity 99.9%, 0.5 × 100 × 300 (mm)) as the cathode, and a polishing apparatus was assembled as shown in FIG. It was. At this time, the temperature was controlled in a thermostatic chamber (EYELA, NCB-2300), and a DC stabilized power source (YAMABISHI, MD-110-1) was used as a power source. After the treatment, the substrate was immediately washed with acetone, the insulating tape was peeled off and stored in acetone.

-Anodization-
Table 2 shows the anodizing conditions. A substrate having one side masked with an insulating tape (aluminum substrate subjected to electropolishing) was used as an anode, and an aluminum substrate of the same size masked on one side was used as a cathode, and anodization was performed. At this time, the temperature was controlled in a thermostatic bath, and a DC stabilized power source was used as the power source. After the treatment, distilled water was applied in several times to thoroughly wash the substrate.

-Carbon deposition-
A carbon layer was formed by depositing pyrolytic carbon on the inner surface of the nanohole and the outer surface of the light transmission layer by chemical vapor deposition (CVD) using acetylene as a carbon precursor. The anodized aluminum substrate was placed on a quartz boat so that the anodized surface was up, and a maximum of three sheets were placed in the soaking zone in the center of the reaction tube as shown in FIG. FIG. 9 shows the experimental process. After heating up to 600 ° C. in a nitrogen flow for 1 hour, acetylene diluted with nitrogen (concentration: 20% by volume, total flow rate: 500 mL / min) was introduced into the reaction tube, and CVD was performed at 600 ° C. for 2 hours. . Then, acetylene was stopped and it cooled to room temperature under nitrogen circulation. The carbon layer thus obtained had a thickness of 5 nm.

(Example 2)
In Example 1, a coloring structure was produced in the same manner as in Example 1 except that the treatment time in the anodic oxidation treatment was changed from 27 seconds to 35 seconds.

(Example 3)
In Example 1, a coloring structure was produced in the same manner as in Example 1 except that the treatment time in the anodic oxidation treatment was changed from 27 seconds to 44 seconds.

Example 4
In Example 1, a coloring structure was produced in the same manner as in Example 1 except that the treatment time in the anodic oxidation treatment was changed from 27 seconds to 52 seconds.

(Example 5)
In Example 1, a coloring structure was produced in the same manner as in Example 1 except that the treatment time in the anodic oxidation treatment was changed from 27 seconds to 60 seconds.

(Example 6)
In Example 1, a coloring structure was produced in the same manner as in Example 1 except that the treatment time in the anodic oxidation treatment was changed from 27 seconds to 68 seconds.

(Example 7)
In Example 1, a coloring structure was produced in the same manner as in Example 1 except that the treatment time in the anodic oxidation treatment was changed from 27 seconds to 77 seconds.

(Example 8)
In Example 1, a color forming structure was produced in the same manner as in Example 1 except that the treatment time in the anodic oxidation treatment was changed from 27 seconds to 150 seconds.

Example 9
In Example 1, a coloring structure was produced in the same manner as in Example 1 except that the treatment time in the anodic oxidation treatment was changed from 27 seconds to 300 seconds.

(Example 10)
In Example 1, a coloring structure was produced in the same manner as in Example 1 except that the treatment time in the anodic oxidation treatment was changed from 27 seconds to 600 seconds.

(Comparative Example 1)
In Example 2, a coloring structure was produced in the same manner as in Example 2 except that carbon was not deposited on the anodized aluminum substrate.

(Comparative Example 2)
In Example 9, a coloring structure was produced in the same manner as in Example 9 except that carbon was not deposited on the anodized aluminum substrate.

FIG. 10 is a graph showing the reflection spectra of the color developing structures of Examples 1 to 7.
From FIG. 10, it can be seen that the peak position where the reflectance is maximum is shifted to the long wavelength side as the anodizing time is increased.

FIG. 11 is a graph showing the relationship between the anodizing time and the thickness of the light transmission layer.
From FIG. 11, when the anodizing time is 27 seconds, the thickness of the light transmitting layer is 127 nm. When the anodizing time is 52 seconds, the thickness of the light transmitting layer is 173 nm, and the anodizing time is 77. It is understood that the thickness of the light transmission layer is 224 nm at the second.

FIG. 12 is a graph showing the reflection spectra of the color developing structures of Examples 2, 8, 9, and 10, and Comparative Examples 1 and 2.
FIG. 13 is a diagram for explaining B / A indicating the degree of interference.
Table 3 shows data comparing Examples 2 and 9 with Comparative Examples 1 and 2. It shows that the degree of interference is so strong that B / A is large. From Table 3, it can be seen that since the value of the example is larger than that of the comparative example, the degree of interference is greater in the example than in the comparative example.

  FIG. 14 is a diagram showing a reflection spectrum of a coloring structure (anodization time 600 seconds) subjected to oxygen plasma treatment (20 to 160 seconds). As shown in FIG. 14, the oxygen plasma treatment time becomes longer, that is, as the carbon layer in the coloring structure is damaged or peeled, the reflectance increases and the coloring contrast (color) decreases (the color is only faint). It can be seen).

  FIG. 15 is a diagram showing the refractive index of the color developing structure (anodic oxidation time 600 seconds) subjected to oxygen plasma treatment (20 to 160 seconds).

  14 and 15, when the oxygen plasma treatment is performed for 20 seconds, the carbon layer formed on the outer surface of the light transmission layer is completely peeled off, but the carbon layer formed on the inner surface of the nanohole remains. is doing. At this time, the reflection spectrum and the refractive index of the coloring structure (oxygen plasma treatment (20 seconds)) are almost the same as the reflection spectrum and the refractive index of the coloring structure (coated in FIGS. 14 and 15) not subjected to the oxygen plasma treatment. Equivalent behavior is shown. For this reason, even if an external force is applied, the carbon layer formed on the outer surface of the light transmission layer is damaged, or the carbon layer formed on the outer surface of the light transmission layer is only peeled off, and the carbon layer becomes light. If it is formed on the inner surface of the nanohole in the transmission layer, it absorbs (attenuates) the light transmitted through the light transmission layer, and is reflected on the surface of the light reflection layer and reflected on the outer surface of the light transmission layer. It can be seen that the strong interference with the light is maintained, and the color contrast (saturation) is not damaged.

  When the oxygen plasma treatment is performed for 160 seconds, not only the carbon layer formed on the outer surface of the light transmission layer but also the carbon layer formed on the inner surface of the nanohole is peeled off to form a carbon layer formed on the inner surface of the nanohole. Is in a state that hardly remains. At this time, the reflection spectrum and refractive index of the coloring structure (oxygen plasma treatment (160 seconds)) are larger than the reflection spectrum and refractive index of the coloring structure (coated in FIGS. 14 and 15) not subjected to oxygen plasma treatment. It shows different behavior. From this, when the carbon layer formed on the inner surface of the nanohole is peeled off (when the carbon layer is not formed on the inner surface of the nanohole), the light transmitted through the light transmitting layer is not absorbed (attenuated). It can be seen that strong interference between the light reflected on the surface of the light reflecting layer and the light reflected on the outer surface of the light transmitting layer cannot be maintained, and the color contrast (saturation) is lowered.

The preferred embodiments of the present invention are as follows.
(Additional remark 1) The coloring structure characterized by including a light reflection layer and the light transmission layer which has a nanohole in this order, and the said light transmission layer has a light absorption layer in the inner surface of the said nanohole.
(Additional remark 2) The color development structure of Additional remark 1 whose light absorption layer is a carbon layer.
(Appendix 3) The color developing structure according to any one of appendices 1 to 2, wherein the light absorption layer has a layered structure.
(Appendix 4) The color developing structure according to any one of appendices 1 to 3, wherein the light absorption layer has a thickness of 2 to 20 nm.
(Supplementary note 5) The light-transmitting layer is the color developing structure according to any one of Supplementary notes 1 to 4, wherein the thickness is 100 to 800 nm.
(Appendix 6) The color developing structure according to any one of appendices 1 to 5, wherein the light transmission layer has a plurality of regions each having a different thickness.
(Appendix 7) The color developing structure according to any one of appendices 1 to 6, wherein the light transmission layer has a thickness that continuously changes.
(Additional remark 8) The color reflection structure in any one of Additional remark 1 to 7 whose light reflection layer consists of either aluminum, magnesium, and a magnesium alloy.
(Additional remark 9) It is a manufacturing method of the coloring structure body in any one of additional remarks 1-8, Comprising: The light transmission which forms the light transmissive layer by which the metal substrate was anodized and the nanohole was formed on the light reflection layer A method for producing a coloring structure comprising a layer forming step and a light absorbing layer forming step of forming a light absorbing layer on the inner surface of the nanohole.
(Additional remark 10) The coloring structure of Additional remark 9 whose source gas used at a light absorption layer formation process consists of at least 1 sort (s) of hydrocarbon selected from the group which consists of methane, ethane, propane, acetylene, ethylene, propylene, and benzene. Body manufacturing method.
(Additional remark 11) The manufacturing method of the coloring structure of Additional remark 10 whose source gas further contains nitrogen gas.
(Additional remark 12) The manufacturing method of the color development structure in any one of Additional remark 9 to 11 in which film-forming in a light absorption layer formation process is performed on the conditions of 400-1000 degreeC under atmospheric pressure.
(Additional remark 13) The manufacturing method of the color development structure of Additional remark 12 with which film-forming in a light absorption layer formation process is performed on the conditions of 600-800 degreeC under atmospheric pressure.
(Additional remark 14) The manufacturing method of the color development structure of Additional remarks 9-13 which performs an anodizing process by changing the time which a metal substrate is immersed in electrolyte solution continuously in a light absorption layer formation process.
(Supplementary note 15) An electrical appliance having the coloring structure according to any one of Supplementary notes 1 to 8.

  The coloring structure of the present invention can be suitably used as a housing for electrical products such as personal computers and mobile phones, and can also be suitably used as a decorative optical filter.

FIG. 1A is a schematic explanatory view showing an example of the color developing structure of the present invention. FIG. 1B is a schematic explanatory view showing another example of the color developing structure of the present invention. FIG. 2 is a schematic explanatory view showing an example of an electropolishing apparatus used in the method for producing a color developing structure of the present invention. FIG. 3 is a schematic explanatory view showing an example of an anodic oxidation cell used in the method for producing a coloring structure according to the present invention. FIG. 4 is a schematic explanatory view showing an example of a CVD apparatus used in the method for producing a coloring structure according to the present invention. FIG. 5 is a schematic explanatory view showing an example of the color development state of the color development structure of the present invention. FIG. 6 is a diagram illustrating the color development state of the color development structure of the present invention. FIG. 7 is a schematic explanatory view showing an example of anodizing treatment in the method for producing a color developing structure of the present invention. FIG. 8 is a process diagram showing an example of a method for producing a color developing structure according to the present invention. FIG. 9 is a graph showing an experimental process of carbon deposition in the method for producing a color forming structure of the present invention. FIG. 10 is a graph showing the reflection spectra of the color developing structures of Examples 1 to 7. FIG. 11 is a graph showing the relationship between the anodizing time and the thickness of the light transmission layer. FIG. 12 is a graph showing the reflection spectra of the color developing structures of Examples 2, 8, 9, and 10, and Comparative Examples 1 and 2. FIG. 13 is a diagram for explaining B / A indicating the degree of interference. FIG. 14 is a diagram showing a reflection spectrum of a coloring structure (anodization time 600 seconds) subjected to oxygen plasma treatment (20 to 160 seconds). FIG. 15 is a diagram showing the refractive index of a color developing structure (anodic oxidation time 600 seconds) subjected to oxygen plasma treatment (20 to 160 seconds). FIG. 16 is a schematic explanatory view showing an example of a conventional color developing structure. FIG. 17 is a schematic explanatory view showing another example of a conventional color forming structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Coloring structure 11 Light reflection layer 11a Surface 12 Nanohole 13 Light transmission layer 13a Outer surface 14 Light absorption layer 100 Structure 101 Metal layer 101a Surface 102 Nanohole 103 Anodized layer 103a Outer surface 110 Interference color coloring metal body 111 Metal substrate 111a Surface 112 Barrier layer 112a Outer surface 113 Light reflective layer

Claims (7)

A coloring structure comprising a light reflection layer and a light transmission layer having nanoholes in this order, wherein the light transmission layer has a carbon layer on an inner surface of the nanohole. The color developing structure according to claim 1, wherein the carbon layer is a light absorbing layer . The color developing structure according to claim 1, wherein the carbon layer has a thickness of 2 to 20 nm.   The color developing structure according to claim 1, wherein the light transmission layer has a thickness of 100 to 800 nm.   The color developing structure according to claim 1, wherein the light transmission layer has a plurality of regions having different thicknesses. 6. The method for producing a color developing structure according to claim 1, wherein a light transmitting layer forming step is performed in which a metal substrate is anodized to form a light transmitting layer in which nanoholes are formed on the light reflecting layer. When manufacturing method of coloring structure which comprises a carbon layer formation step of forming a carbon layer on the inner surface of the nanoholes. An electrical product having the coloring structure according to any one of claims 1 to 5 as a casing .