KR102155610B1 - Coating method of color pattern for stainless plate - Google Patents

Abstract

The present invention provides a step of preparing a stainless plate, applying a pattern to the stainless plate using an ultraviolet curing paint, curing the pattern to form a pattern layer, forming a nickel plating layer on the surface of the stainless plate It relates to a method for forming a color pattern of a stainless steel plate comprising the step of, wherein the reduction rate of lightness according to HSL color coordinates of the stainless steel plate on which the nickel plated layer is formed with respect to the stainless plate before the nickel plated layer is formed is 20% or less. As a result, the color pattern and the color of the stainless steel plate can be maintained even after the nickel plating layer is formed.

Description

Method of forming color pattern of stainless steel plate. {COATING METHOD OF COLOR PATTERN FOR STAINLESS PLATE}

The present invention relates to a method for forming a color pattern of a stainless steel plate, and more particularly, to a method for forming a pattern for stably forming a color pattern on the surface of a stainless steel plate used for an advertisement or the like.

In general, billboards are made of plastic, wood, metal, etc. depending on the installation location or size. In the case of small advertisement boards, advertisement boards made of stainless steel are being manufactured in order to use the gloss of metal materials.

A billboard consists of a frame and a display on which information for advertisement is printed. If the display is made of plastic or wood, it is possible to easily print a desired color and pattern. However, in the case of stainless steel, the ink for printing the pattern is easily printed on the surface. Since it is not adsorbed, there is a problem that it is easily peeled off by an external impact.

In view of this problem, a method of forming a pattern with UV-curable ink on a stainless steel display portion and then irradiating UV light to cure it is used, but in this case, when the UV-curable ink is cured, chemical bonding with the stainless steel surface is not achieved. Therefore, the print pattern is eventually peeled off and color bleeding occurs after printing. In order to solve this problem, a method of forming a protective layer on the surface of stainless steel on which the pattern is printed can be used. Formation of a protective layer using a transparent resin composition is not easy due to compatibility with stainless steel, and the protective layer is formed through the plating process. In the case of formation, it is possible to fix the pattern, but when the metal thin film for plating is formed, the unique color of the pattern is deteriorated, and the color peculiar to stainless steel is not implemented, so that the quality of the advertisement board is deteriorated.

The plating technology on the surface of stainless steel is a process of plating a Cu-Ni thin film on the stainless steel diaphragm described in Korean Patent Publication No. 10-0240012 by sputtering, or sputtering or ions on the intermediate layer formed of stainless steel described in Korean Patent No. 10-1287903. A process of applying a color layer made of a ceramic material by the plating method is known, but this is not a process of plating while utilizing the color of stainless steel like an advertisement board, but a technique for simply forming a plating layer. In particular, Korean Patent Publication No. 10-1287903 describes the point of applying a color layer with a ceramic material, but this only realizes a single color by applying a ceramic layer, but does not expose the color of the stainless steel underneath. There is a difficult problem in implementing patterns of various colors.

Korean Registered Patent Publication No. 10-0240012 Korean Patent Publication No. 10-1287903

The present invention has been devised in view of the problems of the prior art as described above, and an object of the present invention is to provide a method of forming a plating layer to form a color pattern on the surface of a stainless steel plate and stabilize it.

In addition, it is an object of the present invention to provide a color pattern forming method capable of sufficiently realizing a visual effect by allowing the color pattern and the color sense of stainless steel to be maintained even after the plating layer is formed.

The method for forming a color pattern of a stainless steel plate according to the present invention for solving the above problems includes: preparing a stainless steel plate, applying a pattern to the stainless steel plate using UV-curable ink, and curing the pattern to form a pattern layer. Forming, including forming a nickel plated layer on the surface of the stainless steel plate, and lightness according to HSL color coordinates of the stainless plate on which the nickel plated layer is formed with respect to the stainless plate before the nickel plated layer is formed It is characterized in that the reduction rate is 20% or less.

In this case, the thickness of the nickel plating layer may be 0.1 to 10 μm, and information is displayed by the pattern layer formed on the stainless steel plate.

According to the method for forming a color pattern of a stainless steel plate according to the present invention, a plating layer can be formed to stabilize the color pattern and form a color pattern on the surface of the stainless steel plate.

In addition, even after the plating layer is formed, the color pattern and the color sense of stainless steel can be maintained, so that the visual effect can be sufficiently realized.

Hereinafter, the present invention will be described in detail.

The method for forming a color pattern of a stainless steel plate according to the present invention includes preparing a stainless steel plate, applying a pattern to the stainless steel plate using UV-curable ink, curing the pattern to form a pattern layer, and the stainless steel plate. And forming a nickel plating layer on the surface of the.

These color pattern formation and nickel plating processes are the same as those of a conventional printing process and plating process. However, in the present invention, the plating layer protects the color pattern formed on the stainless steel plate and does not reduce the inherent color sense of the stainless steel plate. Since the purpose is to achieve this purpose, a color pattern is formed according to specific process conditions.

The pattern layer formed on the stainless steel plate serves as a display unit for displaying information. Accordingly, the stainless steel plate on which such a pattern layer is formed may be used as a display unit for displaying information by constituting a part of an advertisement board or a product housing.

In order to achieve this purpose, the reduction rate of lightness according to HSL color coordinates of the stainless steel plate on which the nickel plated layer is formed with respect to the stainless steel plate before the nickel plated layer is formed should be 20% or less. If the reduction rate of the brightness is too large, the unique metallic color of stainless steel is changed, making it difficult to visually sense that it is made of stainless steel.

This is, when the stainless steel plate of the present invention is applied to constitute the display unit of the advertisement board, the advertisement plate made of stainless steel is composed of a display unit for printing a pattern including advertisement information, a support for supporting it, and a fixture for fixing to a wall or floor. , The display unit made of stainless steel enhances the visual effect as an advertisement board by expressing the unique color of the metal. When the color is changed, the quality of the advertisement board is deteriorated.

The method of forming the color pattern will be described in detail as follows.

First, remove foreign substances from the surface of the stainless steel plate cut to a size suitable for the display of the billboard. To this end, a short ball is shot on the surface of the stainless steel plate to remove foreign matter. Through this process, the adhesion of the ink is improved when UV-curable ink is applied along with the removal of foreign matter on the surface, thereby preventing the spreading of the printed pattern. Can be suppressed.

Next, the pre-treatment of the stainless steel plate is performed, which not only removes residual foreign matter, but also improves the color and gloss of the stainless steel plate. In this pretreatment process, the hot water washing, degreasing, washing and drying processes may be sequentially repeated one or more times, which can be appropriately selected according to the type or state of the stainless steel plate as a raw material.

In other words, in the hot water washing process, hot water at 50 to 60℃ is sprayed at a pressure of 0.5 to 1kgf/㎠ to remove foreign substances, and in the degreasing process, a neutral surfactant is diluted and mixed in a concentration of 5 to 10% in hot water at 50 to 60℃. One liquid detergent is sprayed onto the surface of the stainless steel plate at a spraying pressure of 1 to 2kgf/cm2. Through this degreasing process, oil or other foreign matter remaining on the surface is removed. After that, the pretreatment of the surface is completed through water washing and drying.

A pattern is printed on the surface of the stainless steel plate prepared as described above using UV-curable ink.

In this case, in order to facilitate the application of the UV-curable ink, the surface of the stainless steel may be etched with an etching solution containing 18 to 36% sulfuric acid. This etching treatment has an advantageous effect on the application of ink and formation of a plating layer, but it is possible to deteriorate the color or gloss of stainless steel, so it is performed only when necessary. In addition, when using an etching solution, a neutralization and washing process are required.

Printing of the pattern using the UV-curable ink may be performed according to a conventional printing method. The UV-curable ink is a color ink and can print various patterns on the surface of the stainless steel plate.

In addition, since it can be cured by irradiating UV rays for 30 minutes to 1 hour after printing, a pattern layer is formed. Since this pattern layer can be easily peeled off the surface of the stainless steel plate, it is preferable to form a plating layer immediately after the pattern layer is cured.

In general, since ink cannot be chemically adsorbed on an inactive surface, such as stainless steel, a base coat is formed with a resin composition for this purpose.However, when the base coat layer is formed, the unique color or luster of stainless steel disappears, so a separate base layer is formed in the present invention. Without forming a color pattern layer.

In one embodiment, the UV-curable paint is applied to a thickness of 10 to 20 μm by a spray method, and then the surface temperature is raised to 70 to 80°C by irradiating infrared rays with an infrared lamp, and the solvent is removed for 5 to 10 minutes by applying hot air. . Thereafter, the UV-curable paint is cured by irradiating ultraviolet rays with an amount of 4,000 to 6,000 mJ/cm 2.

The stainless steel plate on which the pattern layer is formed forms a plated layer through electroless nickel plating. Nickel sulfate or nickel chloride may be used as the plating solution for the nickel plating, and it is used in the form of a nickel salt, and the amount of the nickel salt is preferably 0.1 to 10 g/ℓ.

In addition, the plating solution contains a reducing agent and a complexing agent, and the reducing agent is hypophosphorous acid (H ₂ PO ₂ ), hypophosphite such as sodium hypophosphite (NaH ₂ PO ₂ ·H ₂ O), dimethylamine borane, trimethylamine Borane and hydrazine can be used. It is preferable that the amount of the reducing agent is 0.1 to 10 g/ℓ.

In addition, as the complexing agent, carboxylic acids such as malic acid, succinic acid, lactic acid and citric acid, amino acids such as glycine, alanine, iminodiacetic acid, arginine and glutamic acid may be used, and it is preferably contained in the range of 0.1 to 10 g/L. Do.

In the present invention, a stabilizer is further added to the plating solution because it is necessary to make the plating layer thin and to serve as a protective layer of the color pattern through the formation of a uniform plating layer. As the stabilizer, a water-soluble lead salt or a sulfur compound is usually used, and as a result of experiments using various stabilizers, it has been found that it is effective to use a triazole compound.

These stabilizers play a role in increasing the stability of the plating solution, but if the ingredients of the stabilizer are not appropriate, they may cause discoloration of the deposit or make unnecessary gloss, and cause step or skip plating. It is necessary to find a suitable stabilizer.

As a stabilizer used in the present invention, 1,2,4-triazolate (1,2,4-triazolate) or 1,2,3-triazolate (1,2,3-triazolate), which is a salt of triazole, is used. In use, the stabilizer is included in an amount of 0.1 to 10 mg/ℓ, thereby improving the efficiency of nickel plating.

The plating layer may be formed by immersing the surface of the stainless steel plate in a plating bath for a certain period of time. The temperature of the plating bath is determined in consideration of the stability of the bath and the precipitation rate, but is preferably in the range of 30 to 80°C. Further, the thickness of the plating layer can be appropriately adjusted by adjusting the immersion time in the plating bath, and the thickness of the plating layer is preferably 0.1 to 10 μm.

If the thickness of the plating layer is too thin, it cannot function as a protective film, and if it is too thick, it causes the color of the stainless steel plate and the pattern layer printed on it to be reduced.Therefore, it is necessary to adjust the process conditions so that the thickness of the plating layer falls within the above range. have.

The formation of the plating layer through coating deposition proceeds to the desired thickness or is deposited until metal ions are depleted from the solution, the deposition rate is generally 0.1 to 15 mil (0.001 inch, 25 μm) per hour, preferably It was found to vary from 0.1 to 5 mils.

Whether or not the color is deteriorated due to the application of the plating layer is determined by the reduction rate of lightness according to the HSL color coordinates. The HSL color coordinates represent color coordinates in terms of hue, saturation, and lightness. In the case of general stainless steel, hue, saturation, and brightness represent 48°, 7%, and 87%, respectively. When the plating layer is formed on the surface, not only the hue and saturation but also the brightness are significantly reduced, and when the reduction rate of the brightness exceeds 20%, the metallic luster is completely lost and the unique color of the stainless steel plate cannot be expressed. In addition, the reduction rate of the brightness is preferably 10% or less, more preferably 5% or less. In addition, in the case of hue, a change of more than 1° occurs, and in the case of saturation, even when a change of about 5% occurs, the unique color of the stainless steel plate is lost. there is a problem.

Therefore, the plating layer should be formed so that the reduction in brightness according to the HSL color coordinate is 20% or less, preferably 10% or less, and more preferably 5% or less.

For this, factors such as concentration, composition, and deposition rate of the plating solution were found to have an influence, and as described above, the deposition rate was increased from 0.1 to 5 mil ( 0.001 inch, 25 μm) was found to be able to form an optimized plating layer.

In order to confirm the effect of the method for forming a color pattern of a stainless steel plate according to the present invention, the test specimen was evaluated as follows.

A stainless steel plate generally used for advertisement boards was cut into a size of 10×10 cm to prepare a specimen, and then foreign substances were removed and dried through a pretreatment process.

A rectangular pattern having a size of 1 x 1 cm was printed on the surface of the specimen with an ultraviolet curing paint. Printing was performed by a spray method, and was applied to a thickness of 10 to 20 μm. After the coating was applied, infrared rays were irradiated with an infrared lamp to remove the solvent by applying hot air for 5 minutes while raising the surface temperature to 70 to 80°C. After that, it was cured by irradiating ultraviolet rays with an amount of about 5,000mJ/cm2.

The plated layer was formed by electroless nickel plating on the stainless steel plate on which the pattern was printed. As the plating solution, 5 g/ℓ of nickel chloride aqueous solution was used, ₂ g/ℓ of sodium hypophosphite (NaH ₂ PO ₂ ·H ₂ O) as a reducing agent, 0.1 g/ℓ of succinic acid as a complexing agent, and 1,2,4-tria as a stabilizer A plating solution containing 0.1 g/L of zolate was used. The thickness of the nickel plating layer was 1±0.5 μm, and the deposition rate was 0.8 mil (Example 1).

In addition, for comparison, a color pattern was formed on the stainless steel plate specimen in the same manner as in Example 1, but lead acetate 0.1g/ℓ was used as a stabilizer used in the plating solution, and the thickness of the nickel plating layer was 1±0.5㎛, and deposited. The speed was 0.9 mil (Comparative Example 1).

In addition, a color pattern was formed in the same manner as in Example 1, but the plating layer was formed so that the deposition rate was 12 mil and the thickness of the nickel plating layer was 13±2 μm by controlling the concentration of the plating solution (Comparative Example 2).

The HSL value was obtained from the image photographed of the specimen using a color conversion program, and the results are shown in Table 1. In Table 1, stainless steel was photographed in a state in which foreign substances were removed through a pretreatment process.

Hue(°) Saturation(%) Lightness(%) Stainless steel 48 7 87 Example 1 48 8 85 Comparative Example 1 49 13 74 Comparative Example 2 51 8 58

Looking at the results, in the case of Example 1, there was little difference between stainless steel and brightness, and there was little change in hue and saturation, indicating that the unique color sense of stainless steel was maintained despite the formation of the plating layer. On the other hand, in the case of Comparative Examples 1 and 2, it was found that the color of stainless steel was darkened by the formation of the plating layer, and the metallic gloss was also reduced, so that the color cannot be maintained.

In addition, in Example 1 and Comparative Examples 1 and 2, the pattern layer was not peeled off or spread by the formation of the plating layer, indicating that the plating layer serves as a protective layer.

Although the present invention has been described as the above-mentioned embodiment, it is possible to make various modifications or variations without departing from the gist and scope of the invention. In addition, the appended claims include such modifications or variations that fall within the gist of the present invention.

Claims (3)

Preparing a stainless steel plate;
Applying a pattern to the stainless steel plate using UV-curable ink;
Curing the pattern to form a pattern layer;
Forming a nickel plating layer on the surface of the stainless steel plate on which the pattern layer is formed;
In the method of forming a color pattern of a stainless steel plate comprising a,
The plating solution for forming the nickel plating layer contains 0.1 to 10 g/l of a nickel salt, 0.1 to 10 g/l of a reducing agent, 0.1 to 10 g/l of a complexing agent, and 0.1 to 10 mg/l of a triazole compound. Contains,
In the step of forming the plating layer, the deposition rate is 0.1 to 5 mil (0.001 inch, 25 μm),
The reduction rate of lightness according to HSL color coordinates of the stainless steel plate on which the nickel plated layer is formed relative to the stainless steel plate before the nickel plated layer is formed is 20% or less,
The color pattern forming method of a stainless steel plate, characterized in that by displaying information by the pattern layer formed on the stainless steel plate, it is used as a display unit for displaying information by configuring a part of an advertisement plate or a product housing.
The method according to claim 1,
The method of forming a color pattern of a stainless steel plate, characterized in that the thickness of the nickel plating layer is 0.1 to 10㎛.
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