JPWO2006106716A1 - Surface treated metal products - Google Patents

Abstract

  Provided is a surface-treated metal product obtained by coating the surface of a metal product with a transparent inorganic material such as a carbide, nitride, or carbonitride, for example, a silicon carbonitride film. The surface-treated metal product obtained can be seen through the beautiful luster of the metal surface and can be colored, and even if the surface is touched with fingers, no contact marks such as fingerprints are left and scratches are present. It is not conspicuous and is excellent in corrosion resistance, weather resistance, stain resistance, etc.

Description

  The present invention relates to a surface-treated metal product obtained by coating the surface of a metal product with an inorganic material. More specifically, since the present invention coats the surface with a film of a transparent inorganic material, the metallic surface can be seen through the inorganic material, or can be colored by the interference of light. The present invention relates to a surface-treated metal product having excellent weather resistance, anticorrosion properties, and antifouling properties.

  In recent years, applications such as home appliances such as refrigerators, office equipment such as cabinets, housing equipment such as system kitchens, and outer walls and frames of buildings, metal products such as stainless steel plates and plated steel plates have not been painted. In addition, attempts have been made to use the beautiful luster of the surface of metal products. However, the background of metal products is such that when touching the surface with fingers, contact marks such as fingerprints remain, it is conspicuous even with slight scratches, and especially in the case of building materials, adhesion of dirt and acid rain etc. Due to the effect of, the metal material has a drawback such as corrosion. Therefore, it has been attempted to provide a protective layer such as a coating film or a resin film on the surface of a metal product so as to prevent contact marks of a finger or the like, generation of scratches or corrosion. However, there is no example in which an inorganic material which is transparent and has sufficient weather resistance is provided as a protective film on the surface of a metal product. As an example of forming a protective film or an outer surface coating on the metal surface through which the metal surface can be seen, the following may be mentioned.

Japanese Unexamined Patent Publication No. 6-57178 discloses that a transparent anticorrosive thick film paint is applied to the metal surface of an aluminum alloy road wheel, which is an automobile part, without impairing the transparency of the metal background before application. Patent Document 1 discloses a method for forming a coating film capable of preventing the corrosion of the coating and preventing the adhesion inhibition due to an external impact (Patent Document 1). In this method, since the surface of the road wheel is a three-dimensional curved surface, it is possible to form a protective film by painting, but it is difficult to maintain the anticorrosion effect for a long time due to the occurrence of pinholes. Is.
JP-A-6-57178

Further, Japanese Patent Laid-Open No. 9-277476 has excellent moldability when used for coating the outer surface of a deep-drawn metal can, and a portion of the metal can whose outer surface is not printed has a metal surface. A polyester laminated film used for the outer surface coating of a deep-drawn metal can, which is transparent and has no white spots on the outer surface when the metal product is subjected to retort sterilization treatment (Patent Document 2). The polyester film used to coat the outer surface of the deep-drawn metal can has a crystallization temperature of 100 to 160° C. in order to secure the moldability and prevent the occurrence of white spots during the retort sterilization treatment. A special polyester film containing 0.01 to 1% by weight of a lubricant having an average particle size of 0.01 to 2.5 μm must be used, and a general-purpose inexpensive resin film cannot be used.
JP, 9-277476, A

  The above technique provides a metal product in which a metallic luster is maintained by coating a transparent resin film. Further, a resin laminated steel plate coated with a transparent resin film is also known, and a steel plate coated with a transparent resin such as fluorine or acrylic is also known. However, it is considered that the resin film obtained by the current coating method or laminating method cannot maintain a long-term anticorrosion effect due to pinholes or the like. Further, the surface coating of the resin film has many restrictions because of the workability that only the surface having a specific shape can be coated. Further, there is a problem that the metal coated with the resin cannot be recycled.

Further, conventionally, a technique of forming a film of an inorganic material on the surface of a metal member to impart wear resistance, corrosion resistance, heat resistance and the like has been known (for example, see Patent Documents 3 and 4 below). As far as the person is aware, the idea of coating the surface of a metal product with a film of a transparent, wear-resistant, corrosion-resistant, and heat-resistant carbide, nitride, or carbonitride-based inorganic material was proposed. Was never here.
JP-A-4-165087 JP-A-9-125229

  An object of the present invention is to provide a metal product which is excellent in cosmetic properties, corrosion resistance, weather resistance and the like without impairing the transparency of the surface of the metal product.

  The invention according to claim 1 of the present invention is a surface-treated metal product obtained by coating the surface of a metal product with a transparent inorganic material such as a carbide, a nitride, or a carbonitride.

  The invention according to claim 2 is the surface-treated metal product according to claim 1, wherein the inorganic material having the transparency of a carbide, nitride or carbonitride system produces an interference color with the surface of the metal product.

  The invention according to claim 3 is the surface-treated metal product according to claim 1 or 2, wherein the transparent inorganic material has a Martens hardness of 25 GPa or more.

  The invention according to claim 4 is the surface-treated metal product according to any one of claims 1 to 3, wherein the transparent inorganic material is a silicon carbonitride film.

  The invention according to claim 5 is the surface-treated metal according to any one of claims 1 to 4, wherein the metal surface is provided with designability and/or functionality in advance by physical and/or chemical treatment. It is a product.

  In the invention according to claim 6, the physical and/or chemical treatment is one of surface polishing, embossing, punching, etching, thin film forming, or anodizing. It is a surface-treated metal product.

  In the invention according to claim 7, the metal product before coating is made of stainless steel, aluminum alloy, surface-treated steel, plated steel, aluminum, titanium, magnesium, copper, hastelloy steel, nickel steel or a combination of these metals. And the surface-treated metal product according to any one of claims 1 to 6, which is selected from the group consisting of products made of them and other materials.

  The invention according to claim 8 is a surface-treated titanium product obtained by coating the surface of a titanium color product with a silicon carbonitride film.

  The invention according to claim 9 is a surface-treated magnesium or magnesium alloy product obtained by coating the surface of magnesium or magnesium alloy having an anodized film with a silicon carbonitride film. In the present invention, the film is a thin film that covers the surface of the metal product.

  The surface-treated metal product of the present invention is formed by coating the metal product with a film of an inorganic material, particularly the metal product is coated with a transparent film, and the metal surface can be seen through the inorganic material film, or It looks colored due to light interference and is excellent in weather resistance, corrosion resistance, stain resistance, and the like.

It is a figure which shows the measurement result of the contact angle of the silicon carbonitride film (SiCN film) formed into a film at each substrate (stainless steel plate) temperature. It is a figure which shows the measurement result of the Martens hardness of the silicon carbonitride film formed at each substrate temperature. It is a figure which shows the time-dependent change of the contact angle of the silicon carbonitride film formed on various substrates. It is a figure which shows the time-dependent change of the refractive index of the silicon carbonitride film formed on the silicon plate. It is a figure which shows the time-dependent change of the film thickness of the silicon carbonitride film formed on the silicon plate.

  In the present invention, metal products include intermediate products and processed products of all shapes such as metal plates, pipes and coils. Depending on the application, it may also be combined with other, for example plastic, glass, ceramics. As a metal product, it is also interesting to use the beautiful luster of the surface of the metal product without painting, but on the surface of the metal product surface, touch marks such as fingerprints may remain when touching the surface with fingers. , Even if it has a slight scratch, it is conspicuous, and rust and dirt easily occur due to wind and rain. Therefore, the present invention provides a metal product that solves these problems, that is, a metal product in which the surface of the metal product is coated with a transparent inorganic material such as a carbide, a nitride, or a carbonitride. Is. Having the see-through property means a state in which the background of the metal product surface is seen through, or a state in which the metal product surface is colored in various colors due to light interference with the metal surface. Even if it is completely transparent, it may be a semi-transparent one that looks cloudy to some extent or one that is colored as long as the aesthetics of the background can be felt.

  The carbide, nitride or carbonitride-based inorganic material of the present invention is not limited to one that covers the entire surface of the metal product in a film form, but one that covers a part of the surface as necessary. good. Further, as the inorganic material, a material that can be colored or printed with an organic or inorganic pigment can be used. Furthermore, the same kind or different kinds of inorganic materials may be laminated and coated in multiple layers (having the same thickness or different thicknesses).

  As the carbide, nitride, or carbonitride-based transparent inorganic material of the present invention, a material having a hardness of 25 GPa (Martens hardness) or more is preferable. Specific examples include silicon carbonitride film, carbonitride film, diamond-like carbon, diamond, silicon-diamond, and silicon nitrogen. In the present invention, a silicon carbonitride film is particularly preferable, and the silicon carbonitride film generally means a thin film represented by SiCxNy. However, in SiCxNy, x and y mean numerical values in the range of 0<x<1, 0<y<4/3, respectively, and satisfying 4x+3y=4.

  The metal product before coating is required to be one that can be easily processed such as bending without causing rust or dirt on the surface for a long period of time. Stainless steel, aluminum alloy, surface treated steel, plated steel , Products made of aluminum, titanium, magnesium, copper, Hastelloy steel, nickel steel or combinations of these metals (eg alloys, plywood), and products made of them with other materials, eg plastics, glasses, ceramics It was selected from the group.

  The metal product before coating may have a design and/or functionality imparted to the metal surface in advance by physical and/or chemical treatment. The physical treatment may be any method, for example, as a surface treatment after hot rolling or cold rolling, after hot rolling, a silver white matte surface finish by annealing/descaling, After cold rolling, silver-white glossy surface finish by annealing pickling, smooth glossy surface finish by lightly polishing the glossy surface with polishing rolls, close to mirror surface by performing bright heat treatment after cold rolling There is a glossy surface finish. In addition, the surface treatment by surface polishing includes various types of surface polishing ranging from relatively rough polishing of about #100 to precise polishing by buffing. With this, it is possible to create a rough finish surface to a mirror finish surface. You can

  In addition, as a special finish, a hairline finish with long continuous polishing eyes like hair with a polishing belt of appropriate grain size, a vibration finish with a non-directional hairline polishing finish by multi-axis horizontal polishing, There are also a shot blasting finish when a shot of alumina or the like is blown with high pressure air for finishing, and a glass bead blasting finish when a shot of glass beads is blown with high pressure air. Further, there are punching processing and embossing processing by a press machine or the like.

  Further, by using an abrasive roll in which abrasive particles are adhered to the paper and rotating the abrasive roll to bring it into contact with a metal product, grinding is performed in accordance with the rotational direction. In this case, a linear pattern is formed on the surface of the metal product along the traveling direction. In addition, non-directional grinding is performed by bringing a horizontal polishing machine into contact with a metal product while applying eccentricity and vibration using paper or unwoven cloth to which abrasive particles are fixed. In this case, a nondirectional random pattern is formed on the metal surface. Further, by spraying glass beads or alumina onto the metal product with high-pressure air, a satin uneven pattern is formed on the metal product. In the present invention, all of these are preferable as physical treatment methods for metal products before coating.

Examples of the chemical treatment include etching, thin film forming, or anodizing (forming an oxide film by anodizing). As the thin film forming process, for example, a thin film of TiN, TiO ₂ , TiCN or the like may be formed on the metal surface by a physical vapor deposition (PVD) ion plating technique. When the present invention is combined with these, the wear resistance, corrosion resistance, heat resistance and the like of metal products are further improved.

  The surface or surface pattern of the metal product that has been subjected to the physical and/or chemical treatment is a typical surface appearance of the metal product, and is a surface or pattern that is beautiful in design. The strength or weakness of this pattern or the like can be selectively imparted according to the intended use or preference by changing or adjusting the physical and/or chemical treatment method/conditions. Further, when a bare metal product comes into contact with a finger or the like, the mark remains, resulting in a dirty appearance. Therefore, as described above, after imparting a desired surface pattern to the surface of the metal product, the metal product surface is coated with a transparent inorganic material of the carbide, nitride or carbonitride system of the present invention, The surface of the product can be seen through, but even if the surface is flawed, it is inconspicuous, and even if a finger or the like comes into contact with it, the mark does not remain, and the beautiful surface of the present invention (surface treatment ) It can be a metal product.

  Further, even on the mirror surface of the metal product formed by a physical method or a chemical method, by coating the transparent inorganic material of the carbide, nitride or carbonitride system of the present invention, even if the surface has a flaw The decorative metal product of the present invention is inconspicuous, does not leave a trace thereof even when it is touched by fingers and the like, and does not impair the beautiful surface. Further, the metal surface coated by the thin film forming process may be coated with the carbide, nitride or carbonitride based inorganic material of the present invention. In any case, an interference color can be emitted depending on the film thickness of the coated inorganic material.

  In the present invention, the method/means for coating the surface of the metal product with a transparent inorganic material such as carbide, nitride or carbonitride is not particularly limited, and known methods/means can be adopted. Preferred are, for example, a chemical vapor deposition method, an anodic oxidation method, a sputtering method, and an ion plating method.

In the present invention, by coating the surface of the titanium color product with the silicon carbonitride film, a characteristic surface-treated titanium product having a very robust interference color can be obtained. When titanium is used as an anode in an aqueous solution and electrolyzed using an anodizing device, the titanium surface of the anode reacts with oxygen to form a thin film (oxide film, TiO ₂ ). The oxide film itself is colorless and transparent, but it looks colored due to interference of visible light due to its thickness. Although the color looks different depending on the thickness of the coating, the thickness of the coating is determined by the voltage of anodic oxidation, so that the desired titanium color product can be obtained by adjusting the voltage.

  When this is coated with the inorganic material of the present invention, particularly a silicon carbonitride film, a characteristic surface-treated titanium product having a very robust interference color is obtained. Although the interference color of the original titanium slightly changes due to the thickness of the silicon carbonitride film, the surface-treated titanium product having a desired color can be obtained by designing in consideration of the interference color. When a normal titanium color product is used outdoors, for example, a phenomenon occurs in which the surface of titanium is oxidized due to acid rain to form a hydroxide film, and the interference color of light is completely changed. Although such a phenomenon cannot be solved by an ordinary protective film coating, by covering with a thin and transparent silicon carbonitride film of the present invention, discoloration of interference color can be sufficiently prevented.

  In addition, magnesium alloys have been increasingly used for portable electronic device casings because of their light weight characteristics, but since they are metals that are easily oxidized, it is important to protect them with an oxidation resistant film on the surface. Relies on oxidation and resin coating. However, the magnesium anodic oxide film has large voids as compared with the aluminum oxide film, is porous and has poor oxidation resistance of the film, and only limited color development is obtained. Therefore, a resin coating is further applied on the anodic oxide film, but this will impair the metallic luster of the corners and the distinction from the plastic casing. Further, the resin coating film poses a problem when magnesium is recycled.

  When the silicon carbonitride film (SiCxNy film) of the present invention is formed directly on the magnesium or magnesium alloy or after the magnesium or magnesium alloy surface is subjected to the anodic oxide film, the corrosion resistance performance and the surface hardness are improved. In addition, the fingerprints are difficult to attach or the metal color is emitted, and there are advantages such as not being an obstacle to recycling.

A silicon carbonitride film is deposited on a stainless steel plate that has been mirror-polished by a hot wire chemical vapor deposition method using hexamethyldisilazane (HMDS) and ammonia (NH ₃ ) as raw materials Was coated. When the film thickness of the silicon carbonitride film (SiCxNy film) was changed, the color developed due to the interference between the underlying stainless steel substrate and the transparent SiCxNy film depending on the film thickness, and brown (50 nm) as the film thickness increased. , Purple (75 nm), blue (90 nm), yellow-green (130 nm), gold (150 nm), orange (170 nm), green (190 nm), red-purple (200 nm). The number in parentheses indicates the film thickness of the SiCxNy film measured by the ellipsometry method.

FIG. 1 shows the contact angle measurement results of a silicon carbonitride film (SiCxNy film) having a film thickness of 50 nm formed at each substrate (stainless steel plate) temperature. White circles show the results using HMDS and NH ₃ (50 sccm) as the raw material, and black circles show the results using only HMDS as the raw material. The contact angle before the film formation was 89 degrees, but it can be seen that the value of the contact angle after the film formation of the silicon carbonitride film is small under any conditions. Since the contact angle is small, the wettability with water is improved and the antifouling property is improved.

  FIG. 2 shows the Martens hardness measurement result of the silicon carbonitride film formed at each substrate temperature. The Martens hardness measurement was performed using an ultra-fine indentation hardness tester. It can be seen that by setting the substrate temperature at the time of film formation to 250° C., a silicon carbonitride film having a hardness of 28.7 GPa can be obtained. This is particularly excellent in strength.

  Obtained in this example, the stainless steel sheet coated with a silicon carbonitride film, when immersed in hydrogen fluoride, sulfuric acid, nitric acid, hydrochloric acid, sodium chloride aqueous solution, sodium hydroxide aqueous solution, respectively, interference color change, No film peeling or pinhole formation was observed.

FIG. 3 shows the contact angle of water with respect to a 100-nm-thick silicon carbonitride film (SiCxNy film) formed on a plate surface of aluminum (Al), copper (Cu), stainless steel (SUS), and titanium (Ti). The measurement results are shown. As film forming conditions, the flow rate of HMDS of the raw material was 1.1 sccm, the flow rate of NH ₃ was 50 sccm, the substrate temperature was 250° C., and the tungsten filament temperature was 1750° C. Although the contact angle before film formation is large in the range of 90 to 140 degrees for all metal materials, the value of the contact angle becomes small after the silicon carbonitride film is formed, and the contact angle is soaked in a 10% sulfuric acid solution for a long time. However, there was almost no change in the contact angle.

4 and 5, a silicon carbonitride film (SiCxNy film) having a film thickness of 100 nm is formed on the surface of the silicon plate and treated with sulfuric acid, nitric acid, hydrochloric acid or saline having a concentration of 10% to obtain a refractive index ( 4) and the change in film thickness (FIG. 5) are shown. As film forming conditions, the flow rate of HMDS of the raw material was 1.1 sccm, the flow rate of NH ₃ was 50 sccm, the substrate temperature was 250° C., and the tungsten filament temperature was 1750° C. Since there is almost no change in both the refractive index and the film thickness, it can be seen that neither film quality change nor etching has occurred.

In this example, the surface of a titanium color plate obtained by anodizing a pure titanium plate was covered with a silicon carbonitride film, and changes in interference color were observed. First, according to a conventional method, the anodic oxidation voltage was set to 13 V and 30 V to obtain a titanium color plate which was colored gold (13 V) and blue (30 V), respectively. Then, as in Example 1, a silicon carbonitride film (SiCxNy) was formed on the surface of the titanium color plate by a hot wire chemical vapor deposition method using hexamethyldisilazane (HMDS) and ammonia (NH ₃ ) as raw materials. Film) was formed.

  The film thickness was 60 nm for the gold (13V) titanium color plate and 80 nm for the blue (30V) titanium color plate. Then, depending on the film thickness, due to the interference between the underlying titanium color plate and the transparent SiCxNy film, the gold one was colored blue and the blue one was colored gold. The surface-treated titanium plate obtained by coating the surface thereof with a silicon carbonitride film was very excellent in weather resistance against interference colors.

  The surface-treated metal product of the present invention, by coating an inorganic material having transparency, the texture and gloss of the metal product are retained, and by utilizing the optical interference effect between the inorganic material and the base, A beautiful color tone is also added. Further, the coating film has excellent fingerprint resistance, is not conspicuous even if the surface is scratched, and has excellent weather resistance. Therefore, the metal product of the present invention can be suitably applied to home appliances such as refrigerators with a bare metal surface, office equipment such as cabinets, housing equipment such as system kitchens, and building materials such as outer walls and inner walls. it can.

[0002]
[Patent Document 1] JP-A-6-57178 [0004]
Further, Japanese Patent Laid-Open No. 9-277476 has excellent moldability when used for coating the outer surface of a deep-drawn metal can, and a portion of the metal can whose outer surface is not printed has a metal surface. A polyester laminated film used for the outer surface coating of a deep-drawn metal can, which is transparent and has no whitening spots on the outer surface coating when the metal product is subjected to retort sterilization treatment (Patent Document 2). The polyester film used to coat the outer surface of the deep-drawn metal can has a crystallization temperature of 100 to 160° C. in order to secure the moldability and prevent the occurrence of white spots during the retort sterilization treatment. A special polyester film containing 0.01 to 1% by weight of a lubricant having an average particle size of 0.01 to 2.5 μm must be used, and a general-purpose inexpensive resin film cannot be used.
[Patent Document 2] JP-A-9-277476 [0005]
The above technique provides a metal product in which a metallic luster is maintained by coating a transparent resin film. Further, a resin laminated steel plate coated with a transparent resin film is also known, and a steel plate coated with a transparent resin such as fluorine or acrylic is also known. However, it is considered that the resin film obtained by the current coating method or laminating method cannot maintain a long-term anticorrosion effect due to pinholes or the like. Further, the surface coating of the resin film has many restrictions because of the workability that only the surface having a specific shape can be coated. Further, there is a problem that the metal coated with the resin cannot be recycled.
[0006]
Further, conventionally, a technique of forming a film of an inorganic material on the surface of a metal member to impart wear resistance, corrosion resistance, heat resistance and the like is known (see, for example, Patent Documents 3 to 6 below). On the other hand, it has been pointed out by the present inventors that a silicon carbonitride film can be used as a transparent surface protective film as an inorganic material (see Non-Patent Documents 1 and 2 below). However, there is no further knowledge about the silicon carbonitride film, and as far as the inventor knows, various metal products whose surface is coated with the silicon carbonitride film have been specifically proposed together with their excellent features. There was no.
[Patent Document 3] JP-A-4-165087 [Patent Document 4] JP-A-9-125229 [Patent Document 5] JP-A-3-97865 [Patent Document 6] JP-A-62-127467 Non-Patent Document 1] K. ODA, A.A. IZUMI, Proceedings of 51st Joint Lecture Meeting on Applied Physics, 2004.03.28, p. 910, 28a-P2-9
[Non-Patent Document 2] T.W. NAKAYAMADA, K.; ODA, A.A. IZUMI, Proceedings of the 52nd Joint Lecture on Applied Physics, 2005.03.29, p. 895, 29p-ZB-14
DISCLOSURE OF THE INVENTION
[Problems to be Solved by the Invention]

[0003]
[0007]
An object of the present invention is to provide a metal product which is excellent in cosmetic properties, corrosion resistance, weather resistance and the like without impairing the transparency of the surface of the metal product.
[Means for Solving the Problems]
[0008]
The invention according to claim 1 of the present invention is a surface-treated metal product obtained by coating a metal surface with a hydrophilic silicon carbonitride film having a Martens hardness of 25 GPa or more and having transparency.
[0009]
The invention according to claim 2 is the surface-treated metal product according to claim 1, wherein the silicon carbonitride film produces an interference color with the metal surface.
[0010]
[0011]
[0012]
The invention according to claim 5 is the surface-treated metal product according to claim 1 or 2, wherein the metal surface is previously provided with design and/or functionality by physical and/or chemical treatment.
[0013]
In the invention according to claim 6, the physical and/or chemical treatment is one of surface polishing, embossing, punching, etching, thin film forming, or anodizing. It is a surface-treated metal product.
[0014]
In the invention according to claim 7, the metal product before coating is made of stainless steel, aluminum alloy, surface-treated steel, plated steel, aluminum, titanium, magnesium, copper, hastelloy steel, nickel steel or a combination of these metals. And the surface-treated metal product according to claim 1, 2, 5 or 6, which is selected from the group consisting of products including them and other materials.
[0015]
The invention according to claim 8 is a surface-treated titanium product obtained by coating the surface of a titanium color product with a silicon carbonitride film.
[0016]
The invention according to claim 9 is a surface-treated magnesium or magnesium alloy product obtained by coating the surface of magnesium or magnesium alloy having an anodized film with a silicon carbonitride film. In the present invention, the film is a thin film that covers the surface of a metal product.

[0004]
It
【The invention's effect】
[0017]
The surface-treated metal product of the present invention is obtained by coating the metal product with a hydrophilic silicon carbonitride film having a Martens hardness of 25 GPa or more and having transparency, and the metal surface can be seen through the inorganic material film, or It looks colored due to light interference, and is excellent in weather resistance, corrosion resistance, stain resistance, and the like.
[Brief description of drawings]
[0018]
FIG. 1 is a diagram showing a measurement result of a contact angle of a silicon carbonitride film (SiCN film) formed at each substrate (stainless steel plate) temperature.
FIG. 2 is a diagram showing measurement results of Martens hardness of a silicon carbonitride film formed at each substrate temperature.
FIG. 3 is a diagram showing changes over time in contact angle of silicon carbonitride films formed on various substrates.
FIG. 4 is a view showing a change with time of a refractive index of a silicon carbonitride film formed on a silicon plate.
FIG. 5 is a view showing a change over time in film thickness of a silicon carbonitride film formed on a silicon plate.
BEST MODE FOR CARRYING OUT THE INVENTION
[0019]
In the present invention, metal products include intermediate products and processed products of all shapes such as metal plates, pipes and coils. Depending on the application, it may also be combined with other, for example plastic, glass, ceramics. As a metal product, it is also interesting to use the beautiful luster of the surface of the metal product without painting, but on the surface of the metal product surface, touch marks such as fingerprints may remain when touching the surface with fingers. , Even if it has a slight scratch, it is conspicuous, and rust and dirt easily occur due to wind and rain. Therefore, the present invention provides a metal product that solves these problems, that is, a metal product in which the surface of the metal product is coated with a transparent inorganic material such as a carbide, a nitride, or a carbonitride. Is. Having the see-through property means a state in which the background of the metal product surface is seen through, or a state in which the metal product surface is colored in various colors due to light interference with the metal surface. Even if it is completely transparent, as long as you can feel the beauty of the background,

[0005]
It may be a semi-transparent one that is easily visible, or one that is colored.
[0020]
The hydrophilic silicon carbonitride film having a Martens hardness of 25 GPa or more and having a see-through property is not limited to one that covers the entire surface of the metal product in a film shape, but may cover a part thereof as necessary. It may be one that has become. The silicon carbonitride film may be colored or printed with an organic or inorganic pigment or the like. Further, the same kind or different kinds of silicon carbonitride films may be laminated and coated in multiple layers (having the same thickness or different thicknesses).
[0021]
The silicon carbonitride film of the present invention has a Martens hardness of 25 GPa or more and is transparent and hydrophilic. The silicon carbonitride film generally means a thin film represented by SiCxNy. However, in SiCxNy, x and y mean numerical values in the range of 0<x<1, 0<y<4/3, respectively, and satisfying 4x+3y=4.
[0022]
The metal product before coating is required to be one that can be easily processed such as bending without causing rust or dirt on the surface for a long period of time. Stainless steel, aluminum alloy, surface treated steel, plated steel , Products made of aluminum, titanium, magnesium, copper, Hastelloy steel, nickel steel or combinations of these metals (eg alloys, plywood), and products made of them with other materials, eg plastics, glasses, ceramics It was selected from the group.
[0023]
The metal product before coating may have a design and/or functionality imparted to the metal surface in advance by physical and/or chemical treatment. The physical treatment may be any method, for example, as a surface treatment after hot rolling or cold rolling, after hot rolling, a silver white matte surface finish by annealing/descaling, After cold rolling, silver-white glossy surface finish by annealing pickling, smooth glossy surface finish by lightly polishing the glossy surface with polishing rolls, close to mirror surface by subjecting to bright heat treatment after cold rolling There is a glossy surface finish. In addition, the surface treatment by surface polishing includes various types of surface polishing ranging from relatively rough polishing of about #100 to precise polishing by buffing. With this, it is possible to create a rough finish surface to a mirror finish surface.

[0007]
However, the traces thereof do not remain, and the decorative (surface-treated) metal product of the present invention can be obtained without impairing the beautiful surface.
[0028]
Further, even on the mirror surface of the metal product formed by a physical method or a chemical method, by coating the transparent inorganic material of the carbide, nitride or carbonitride system of the present invention, even if the surface has a flaw The decorative metal product of the present invention is inconspicuous, does not leave a trace thereof even when it is touched by fingers and the like, and does not impair the beautiful surface. Further, the metal surface coated by the thin film forming process may be coated with the carbide, nitride or carbonitride based inorganic material of the present invention. In any case, an interference color can be emitted depending on the film thickness of the coated inorganic material.
[0029]
In the present invention, the method/means for coating the surface of the metal product with a hydrophilic silicon carbonitride film having a Martens hardness of 25 GPa or more and having transparency is not particularly limited, and known methods/means can be adopted. .. Preferred are, for example, a chemical vapor deposition method, an anodic oxidation method, a sputtering method, and an ion plating method.
[0030]
In the present invention, by coating the surface of the titanium color product with the silicon carbonitride film, a characteristic surface-treated titanium product having a very robust interference color can be obtained. When titanium is used as an anode in an aqueous solution and electrolyzed using an anodizing device, the titanium surface of the anode reacts with oxygen to form a thin film (oxide film, TiO ₂ ). The oxide film itself is colorless and transparent, but it looks colored due to interference of visible light due to its thickness. Although the color looks different depending on the thickness of the coating, the thickness of the coating is determined by the voltage of anodic oxidation, so that the desired titanium color product can be obtained by adjusting the voltage.
[0031]
Then, when this is coated with the silicon carbonitride film of the present invention, a characteristic surface-treated titanium product having a very robust interference color is obtained. Although the interference color of the original titanium changes slightly due to the thickness of the silicon carbonitride film, the surface-treated titanium product having a desired color can be obtained by designing in consideration of it in advance. When a normal titanium color product is used outdoors, for example, a phenomenon occurs in which the surface of titanium is oxidized due to acid rain to form a hydroxide film, and the interference color of light is completely changed. Such a phenomenon cannot be solved by an ordinary protective film coating, but by coating with a thin and transparent silicon carbonitride film of the present invention, it is possible to sufficiently prevent discoloration of interference color.

[0010]
A visible titanium color plate was obtained. Then, as in Example 1, a silicon carbonitride film (SiCxNy) was formed on the surface of the titanium color plate by a hot wire chemical vapor deposition method using hexamethyldisilazane (HMDS) and ammonia (NH ₃ ) as raw materials. Film) was formed.
[0041]
The film thickness was 60 nm for the gold (13V) titanium color plate and 80 nm for the blue (30V) titanium color plate. Then, depending on the film thickness, due to the interference between the underlying titanium color plate and the transparent SiCxNy film, the gold one was colored blue and the blue one was colored gold. The surface-treated titanium plate obtained by coating the surface thereof with a silicon carbonitride film was very excellent in weather resistance against interference colors.
[Industrial availability]
[0042]
The surface-treated metal product of the present invention is coated with a hydrophilic silicon carbonitride film having a Martens hardness of 25 GPa or more and having transparency, so that the background and luster of the metal product are retained, and the silicon carbonitride film and the base material are retained. A beautiful color tone is also imparted by utilizing the optical interference effect with. Further, the coating film has excellent fingerprint resistance, is not conspicuous even if the surface is scratched, and has excellent weather resistance. Therefore, the metal product of the present invention can be suitably applied to home appliances such as refrigerators with a bare metal surface, office equipment such as cabinets, housing equipment such as system kitchens, and building materials such as outer walls and inner walls. it can.

Claims (9)

  A surface-treated metal product obtained by coating a metal surface with a transparent inorganic material such as a carbide, a nitride, or a carbonitride.   The surface-treated metal product according to claim 1, wherein the transparent inorganic material produces an interference color with the metal surface.   The surface-treated metal product according to claim 1, wherein the transparent inorganic material has a Martens hardness of 25 GPa or more.   The surface-treated metal product according to claim 1, wherein the transparent inorganic material is a silicon carbonitride film.   The surface-treated metal product according to any one of claims 1 to 4, wherein the metal surface is previously provided with design and/or functionality by physical and/or chemical treatment.   The surface-treated metal product according to claim 5, wherein the physical and/or chemical treatment is one of surface polishing, embossing, punching, etching, thin film forming and anodizing.   The metal product before coating is made of stainless steel, aluminum alloy, surface-treated steel, plated steel, aluminum, titanium, magnesium, copper, hastelloy steel, nickel steel, or a combination of these metals, and those and other materials. The surface-treated metal product according to any one of claims 1 to 6, which is selected from the group consisting of products.   Surface-treated titanium products made by coating the surface of titanium color products with a silicon carbonitride film.   A surface-treated magnesium or magnesium alloy product obtained by coating the surface of magnesium or a magnesium alloy having an anodized film with a silicon carbonitride film.

Images