KR20190053570A - Coloring method for metal substrate and metal substrate colored by the same - Google Patents

Abstract

The present invention relates to a method for coloring a metal substrate and a metal substrate colored by the method. The method comprises the steps of: (1) forming engraved patterns of various depths on a surface of the metal substrate; and (2) forming a coloring layer on the surface of the metal substrate which has been subjected to the step (1), wherein the coloring layer is formed of plasmonic nanoparticles having a resonance frequency in the visible light region or a dielectric layer in which precursors are dispersed. According to the present invention, a metal substrate having different colors can be provided according to the thickness of the coloring layer, thereby enabling a stereoscopic display of various and beautiful color patterns on the metal substrate.

Description

TECHNICAL FIELD The present invention relates to a method of coloring a metal substrate,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of coloring a metal substrate and a metal substrate colored by the method, and more particularly, to a dielectric substrate having a metal substrate on which an engraved pattern of various depths is formed and on which plasmonic nanoparticles or precursors thereof are dispersed And a color different from the first color is formed according to the thickness of the coloring layer, and a metal substrate colored by the method.

As the industry develops and life becomes rich, there is a growing demand for color metallic substrates capable of three-dimensional representation of various and beautiful color patterns, as well as new materials capable of achieving high performance and high added value while possessing the inherent characteristics of metals.

In general, a method for coloring a metal surface includes a method of directly coloring the surface of a metal material by coating with a color paint, a method of coloring by dipping a metal material in a plating solution, or a method of etching a surface of a metal material by etching to form a concave portion A pattern color texture method in which a color is left in the concave portion after forming the concave portion is used.

As such a conventional method, Japanese Patent Application Laid-Open No. 10-0102078 (KOKAI) discloses a method of forming a pattern or character using an etching technique and forming a plated color only on a pattern or character through gold plating or the like . However, according to this method, environmental pollution due to the use of the plating solution is caused, and there is a limitation that only a single gold color can be obtained.

In addition, Patent Document 2 (Japanese Unexamined Patent Publication (Kokai) No. 4-91875) discloses a method of forming fine irregularities on a stainless steel or Ni-Cr steel with a laser and then applying a noble metal coating on the irregular portion to realize a luxurious color . However, this method is disadvantageous in that the equipment cost is high because it is subjected to a vacuum deposition or a sputtering process.

Therefore, there is a need for research on a metal substrate coloring method capable of three-dimensional expression of various and beautiful color patterns for various metal materials with inexpensive and simple processes.

KR 100102078 B JP 04091875 A

The present invention includes a step of forming a coloring layer composed of a dielectric layer in which plasmonic nanoparticles or precursors thereof are dispersed on the surface of a metal substrate on which an engraved pattern of various depths is formed, And a metal substrate colored by the coloring method.

In order to solve the above-described problems, the present invention provides a method of manufacturing a metal substrate, comprising the steps of: (1) forming an engraved pattern having various depths on a surface of a metal substrate; And (2) forming a coloring layer on the surface of the metal substrate that has been subjected to the step (1), wherein the coloring layer is formed of a plasmonic nanoparticle having a resonance frequency in a visible light region or a dielectric layer having its precursors dispersed therein. Of the present invention.

The metal substrate may include any one or two or more metals selected from the group consisting of nickel, aluminum, copper, and stainless steel.

The plasmonic nanoparticles may include any one or two or more metal nanoparticles selected from the group consisting of gold nanoparticles, silver nanoparticles, copper nanoparticles, indium nanoparticles, tin nanoparticles, and aluminum nanoparticles. The dielectric layer may include any one or two or more selected from the group consisting of polymers, silica, titania, and precursors thereof.

The coloring layer may be a transparent coloring layer.

The upper surface of the colored layer formed according to the step (2) may have a flat shape without bending, and a different strength color may be realized on the surface of the metal substrate according to the depth of the colored layer.

The method of forming the colored layer may be selected from the group consisting of a doctor blade method, a spin coating method, and a drop casting method.

The present invention also provides a colored metal substrate according to the above coloring method.

According to the present invention, there is provided a coloring layer made of a plasmatic nano-particle having a resonance frequency in a visible light region or a dielectric layer in which precursors thereof are dispersed, on the surface of a metal substrate having an engraved pattern of various depths formed thereon, Can provide a metal substrate having a different color.

Accordingly, the present invention enables stereoscopic representation of various and beautiful color designs with respect to various metal substrates, and manufacturing cost is low because it can be colored by a simple process as compared with the conventional method.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 schematically shows a coloring step of a metal substrate according to one embodiment of the present invention. Fig.
Figure 2 shows photographs of metal substrates colored according to a coloring process according to an example of the present invention.

Hereinafter, the present invention will be described in detail. Prior to that, terms and words used in the present specification and claims should not be construed in a conventional or dictionary sense, and the inventor can appropriately define the concept of a term in order to describe its invention in the best possible way It should be construed as meaning and concept consistent with the technical idea of the present invention. Therefore, the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention, and not all of the technical ideas of the present invention are described. Therefore, It should be understood that various equivalents and modifications may be present.

The present invention relates to a method of coloring a metal substrate and a method of coloring the metal substrate by (1) forming an engraved pattern having various depths on the surface of the metal substrate; And (2) forming a coloring layer on the surface of the metal substrate that has undergone the step (1), wherein the coloring layer is formed of a plasmonic nanoparticle having a resonance frequency in a visible light region or a dielectric layer in which the precursor thereof is dispersed. FIG. 1 schematically shows a metal substrate coloring process according to one embodiment of the present invention, and the present invention will be described in detail with reference to FIG.

(1) a step of forming an engraved pattern

This step is a step of forming engraving patterns of various depths on the surface of the metal substrate.

As the metal substrate, metals commonly used in this field can be used without limitation. For example, the metal substrate may include any one or two or more metals selected from the group consisting of nickel, aluminum, copper, and stainless steel, and preferably a metal substrate in the form of a foil in which a relief pattern can be easily formed.

The depth of the engraved pattern may determine the thickness of the coloring layer formed in step (2) to be performed at a later time, and colors having different intensities depending on the thickness of the coloring layer may be implemented. That is, the present invention can provide various strength colors on a metal substrate by forming engraved patterns of various depths on a metal substrate surface, and as a result, a metal substrate having a three-dimensional color pattern can be provided.

(2) Coloring layer formation step

This step is a step of forming a coloring layer comprising a plasmonic nanoparticle having a resonance frequency in a visible light region or a dielectric layer in which precursors thereof are dispersed on the surface of the metal substrate that has undergone the above step (1).

As used herein, the term " plasmonic nanoparticles " means metal nanoparticles having the ability to cause surface plasmon. Specifically, the metal nanoparticles have a phenomenon (surface plasmon resonance effect) in which light is strongly absorbed or scattered at a specific wavelength depending on the kind thereof. Using this principle, the present invention is to embed plasmonic nanoparticles having a resonant frequency in the visible light region in the colored layer to realize various colors on the surface of the metal substrate. In addition, the plasmonic nanoparticles have excellent absorption and scattering characteristics as well as optical stability compared to an organic dye.

As such plasmonic nanoparticles, any one or two or more metal nanoparticles selected from the group consisting of gold nanoparticles, silver nanoparticles, copper nanoparticles, indium nanoparticles, tin nanoparticles and aluminum nanoparticles may be used, Nanoparticles can be used. In addition, the precursor may be used instead of the plasmonic nanoparticles. For example, when metal salts of these metals are used instead of nanoparticles as a precursor for forming the metal nanoparticles, a dielectric layer in which metal nanoparticles are dispersed through additional precipitation process .

The dielectric layer may include a dielectric or a precursor thereof, and may include one or more selected from the group consisting of polymers, silica, titania, and precursors thereof.

The polymer may include any one or two or more selected from the group consisting of polyvinylpyrrolidone, ethyl cellulose, polyvinyl alcohol, and polyvinyl butyral .

The silica precursor may include one or more selected from the group consisting of perhydropolysilazane, methyltriethoxysilane, tetramethoxysilane, and tetraethylorthosilicate. can do. The silica (SiO ₂ ) is composed of the most abundant elements in the natural world, and not only can it be synthesized at a low cost, but also has excellent properties such as light transmittance, chemical inertness, photochemical stability and colloidal stability. Particularly, silica is a coating material having high transparency, and the coloring layer according to the present invention has high transparency.

The titania precursor may include any one or two or more selected from the group consisting of titanium tetrachloride, titanium butoxide, titanium ethoxide and titanium isopropoxide . When titania having a refractive index higher than that of silica is used in place of silica as a dielectric material, different colors can be realized while using the same plasmonic nanoparticles.

In this step (coloring layer forming step), the dielectric or its precursor may be used in a form mixed with a solvent. That is, the coloring layer according to the present invention can be formed by applying a dispersion liquid in which a plasmonic nanoparticle or a precursor thereof is dispersed in a solution of a dielectric or dielectric precursor to the metal substrate. As the solvent, any one generally used in the field may be used without limitation, and any one or two or more selected from the group consisting of ethanol, methanol, water, dibutyl ether, dimethylformamide and chloroform may be used.

The dielectric layer according to the present invention may have a high transparency, and accordingly, the colored layer made of the dielectric layer may be a transparent colored layer. In the colored layer, a color is formed on the metal substrate in such a manner that the color of the transparent dielectric layer and the specific wavelength is absorbed and the complementary color is expressed. Here, the specific wavelength refers to the resonance frequency in the visible light region of the plasmonic nanoparticle. The type of color realized on the metal substrate is affected by the color of the transparent dielectric layer and the resonance frequency of the plasmonic nanoparticles. However, the intensity of the color realized on the metal substrate is influenced by the plasmonic The amount of the nanoparticles or the precursor thereof, or the depth of the colored layer.

More specifically, according to the present invention, in the case where the depressed pattern is relatively deep on the metal substrate and the colored layer is thick, the plasmonic nanoparticles are much more and more deeply distributed than the non-depressed portion. Therefore, a relatively high intensity color can be realized in a deep-formed engraved pattern portion. In this regard, the coating process according to the present invention will be described in more detail with reference to FIG.

1, a colored layer 200 formed in accordance with an embodiment of the present invention is shown in red. As shown in FIG. 1, the upper surface of the colored layer 200 formed according to the step (2) may have a flat shape without bending. The coloring layer 200 having various depths can be formed on the metal base Ni by forming the coloring layer 200 flat on the metal base Ni on which the engraved patterns of various depths are formed, Different colors may be implemented on the surface of the metal base Ni according to the thickness of the layer 200.

More specifically, referring to FIG. 1, a nickel (Ni) foil is used as a metal substrate, and engraved patterns 100 and 110 having different depths are formed on the nickel foil, Are formed. 2 shows a photograph of a nickel (Ni) foil after completion of the coloring process. 2, the portion of the first engraved pattern 100 having the deepest depth has the darkest color and the portion of the second engraved pattern 110 having the intermediate depth has a lower intensity than that of the first engraved pattern 100 And the portion 120 where the engraved pattern is not formed shows a light color having the lowest color intensity. That is, FIG. 2 shows that the color intensity is different depending on the thickness of the colored layer 200 formed on the nickel (Ni) foil. Accordingly, the present inventors have found that by forming a colored layer comprising a dielectric layer in which plasmonic nanoparticles having a resonance frequency in a visible light region are dispersed on the surface of a metal substrate on which engraved patterns with various depths are formed, Can provide a metal substrate having a different color, and completed the present invention.

As a method for forming the colored layer, known coating methods can be used without limitation. Preferably, a method of coating the upper surface of the colored layer in an equilibrium manner, for example, a method selected from the group consisting of a doctor blade method, a spin coating method and a drop casting method, may be used.

The method of coloring a metal substrate according to the present invention may further comprise the step of curing the metal substrate that has undergone the step (2). As the curing method, a method generally used in this field can be used without limitation. For example, a method of curing by heating or a method of curing by irradiation of ultraviolet ray can be used.

For example, if a silica precursor such as Perhydropolysilazane is used to form a dielectric layer comprising silica, the curing step is necessary. The curing may be carried out using a thermal curing method of heating at a temperature of 250 to 350 ° C. for 60 to 120 minutes, and it is preferable that a hard colored layer is formed on the metal substrate when curing under the above conditions.

In the step (2), when the metal salt of the plasmonic nanoparticle, which is a precursor of the plastic nanoparticle, is mixed with the dielectric or its precursor solution to form a colored layer, ultraviolet rays, visible rays, To cause photolysis to form plasmonic nanoparticles in the dielectric layer to form a colored layer.

On the other hand, according to the present invention, a colored metal substrate is provided according to the above coloring method. For example, FIG. 2 shows a photograph of a metal substrate after the formation of a colored layer according to an embodiment of the present invention, followed by a curing step. Referring to FIG. 2, it can be seen that colors of various intensities are realized in a three-dimensional manner on a metal substrate.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example (see Fig. 1)

A nickel (Ni) foil was prepared as a metal substrate, and a first engraved pattern 100 and a second engraved pattern 110 having different depths were formed on the surface of the nickel (Ni) foil by an imprint method.

Next, 49 mg of gold nanoparticles as the plasmonic nanoparticles were added to 1 ml of the silica precursor solution to prepare a colorant coating solution. At this time, the silica precursor solution is a mixture of perhydropolysilazane, which is a silica precursor, and dibutyl ether, which is a solvent, in a concentration of 0.993 mol.

1, the upper surface of the colored layer 200 is formed into a flat shape without bending, as shown in FIG. 1, by coating the colorant coating liquid on a nickel foil having the engraved pattern formed thereon. Respectively.

The coloring process was then completed by curing the coated nickel foil at 300 캜 for 90 minutes.

Assessment Methods

The coloration of the colored nickel foil according to the embodiment of the present invention was visually observed, and a photograph of the nickel foil after completion of the coloring process is shown in FIG. Referring to FIG. 2, a color having a low intensity on the nickel foil is formed in the order of the first engraved pattern 100 having the deepest depth, the second engraved pattern 110 having the middle depth, and the portion 120 having no engraved pattern It can be confirmed that it is implemented. That is, according to the present invention, it can be confirmed that the intensity of color is different depending on the depth of the engraved pattern formed on the nickel foil, that is, the thickness of the colored layer.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, Should be construed as being included in the scope of the present invention.

Claims (9)

(1) forming engraved patterns of various depths on the surface of the metal substrate; And
(2) forming a coloring layer on the surface of the metal substrate having been subjected to the step (1), wherein the coloring layer comprises a plasma layer having a resonance frequency in a visible light region or a dielectric layer in which precursors thereof are dispersed Coloring method. The method according to claim 1,
Wherein the metal substrate comprises one or two or more metals selected from the group consisting of nickel, aluminum, copper and stainless steel. The method according to claim 1,
Wherein the plasmonic nanoparticle comprises one or two or more metal nanoparticles selected from the group consisting of gold nanoparticles, silver nanoparticles, copper nanoparticles, indium nanoparticles, tin nanoparticles and aluminum nanoparticles. A method of coloring a substrate. The method according to claim 1,
Wherein the dielectric layer comprises one or more selected from the group consisting of polymers, silica, titania, and precursors thereof. The method according to claim 1,
Wherein the colored layer is a transparent colored layer. The method according to claim 1,
Wherein the upper surface of the colored layer formed according to the step (2) has a flat shape without bending. The method according to claim 6,
Wherein a color of a different intensity is realized on the surface of the metal substrate in accordance with the depth of the colored layer. The method according to claim 1,
Wherein the method of forming the colored layer is selected from the group consisting of a doctor blade method, a spin coating method, and a drop casting method. A metal substrate colored according to the coloring method of any one of claims 1 to 8.

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