JP5132685B2 - Metal thermoformed body, method for producing the same, and method for producing patterned metal sheet - Google Patents

Description

  The present invention relates to a metal product formed by heating, and relates to a technique for producing a metal thermoformed body that can suppress oxidation that proceeds from the surface by heating in the atmosphere.

  As a unique metal processing technology originating in the Edo period about 400 years ago, a method called wood grain is known. This wood grain is a single piece of bullion made by stacking and joining several bullions of different colors, such as copper, silver, gold, etc., using various processing methods on the surface. It is possible to create beautiful patterns with rich visual interest. For example, an original pattern can be formed by repeating the process of making irregularities on the wood grain with a chisel and scraping the convex parts or flattening with a hammer. Furthermore, it is also possible to boil this with a patina and color it. This kind of wood grain is mainly used as a technique for decorating samurai swords (swords), and it is currently being used not only in Japan but also in the United States and other countries around the world. However, it is hard to say that the technology itself is sufficiently known or popular.

In the technology to form a pattern by superimposing a plurality of metal plates having different color tones, in order to prevent oxidation during diffusion bonding, superposition is performed to prevent air (oxygen) from entering. A technique of applying a mixture of charcoal and powder to the periphery of a metal plate and heating it is employed.
In addition, some proposals have been made as an alternative to the method of applying powdered charcoal to the periphery of the metal plates that are overlapped. For example, in Patent Document 1, a red copper plate, a gold copper alloy plate and a silver stainless steel plate are alternately stacked in multiple stages, and the overlapped metal plates are surrounded by an auxiliary iron plate and sealed from the outside air to be sealed from the outside air, It is disclosed that this is heated to 800 to 850 ° C. in a heating furnace, and is laminated metallurgically (that is, diffusion bonding) to obtain a multilayer clad rod.
In Patent Document 2, a corrosion-resistant steel plate such as stainless steel and a copper alloy plate of a different color from this, that is, brass, bronze, bronze, Abyssinian gold, Mannheim gold, Nyurnberg gold, etc. are superimposed, An example is shown in which a steel clad sealed is heated to 800 to 900 ° C. and diffusion bonded to obtain a plate-like clad material having a different color metal phase on the surface. Specifically, it is shown that a stainless steel plate and a brass plate are overlapped and sealed with a 5 mm thin steel plate, placed in a heating furnace, heated to 800 ° C., and then rolled to obtain a plate-like clad material. Has been. As another example, a stainless steel plate and an Abyssinian gold plate having a composition of Cu 86.4%, Zn 11.2%, Sn 1.4% and Au 0.1% are overlapped and sealed with a 5 mm thin steel plate, Put in a heating furnace and heat to 850 ° C. and then roll to obtain a plate-like clad material, or a superposition of a stainless steel plate and an aluminum gold plate with a composition of Cu 96%, Al 5% and Fe 1% It is disclosed to enclose and seal with a thin steel plate, put it in a heating furnace, heat to 800 ° C., and then roll to obtain a plate-like clad material.
Similarly, Patent Document 3 discloses a ferrous metal plate such as ferritic or austenitic stainless steel, a Cu-Zn alloy plate, a Cu-Sn alloy plate, a Cu-Au alloy plate, a Cu-Al alloy. A heating furnace with a metal plate for decoration such as an alloy plate and the joint seam sealed by means such as welding (enclosed and sealed with a thin steel plate having a thickness of 5 mm in the embodiment) to prevent intrusion of outside air And diffusion bonding by heating up to 800 to 900 ° C.
Furthermore, Patent Document 4 discloses a method in which a copper or copper alloy plate is superposed on a steel plate that has been plated with tin or zinc in advance on a required surface, and heated and rolled in a state in which intrusion of outside air from around the joint is prevented. It has been shown that diffusion bonding is performed at a low temperature near the melting point of the plated metal. Specifically, a steel plate with both sides plated with copper is wrapped with a 1 mm thick sheet, welded with a seam, sealed, placed in a heating furnace and heated to 200 ° C. And then rolling to obtain a composite plate. Further, it is disclosed that a brass plate is superposed on both sides of a steel plate plated on both sides with a 1 mm thick thin steel plate, heated to about 450 ° C., and then rolled to obtain a composite plate. .
Japanese Patent Publication No.57-4434 Japanese Patent Publication No.55-36031 Japanese Patent Publication No.55-1986 Japanese Patent Publication No.34-6416

However, in the method of applying the powder mixture with charcoal, the metal plate and the metal plate are partially separated when removed from the heating furnace or in subsequent processing without being sufficiently diffusion-bonded. Sometimes, it was completely separated or disjointed.
Further, in the method described in Patent Document 1, the plurality of stacked metal plates are surrounded by an auxiliary iron plate and sealed from outside air by sealing, but in a state where the plurality of metal plates are pressurized. In addition, the work of wrapping with the auxiliary iron plate requires extremely difficult work, and seal welding requires a high level of skill. In the end, special equipment and advanced skills were required.
Similarly, in the methods described in Patent Document 2 to Patent Document 4, the periphery of a plurality of metal plates is surrounded by a thin steel plate and sealed from the outside air by sealing welding. The operation of surrounding the periphery of the plate with a thin steel plate in a pressurized state requires a very difficult operation and also requires high skill in sealing welding. In the end, special equipment and advanced skills were required.

In the first place, the intent to prevent the intrusion of outside air during diffusion bonding is to prevent oxygen from entering the joints between the stacked metal plates as described above and oxidizing the metal plate material. Therefore, it is possible to prevent oxidation of the metal plate material by performing the heating atmosphere in an atmosphere filled with an inert gas such as argon gas or helium gas or nitrogen gas, not in the air. .
However, since this method forms an antioxidant state by filling with an inert gas or the like, a supply facility such as an inert gas or a special heating facility is required, and the heating time is 8 hours to When it takes 10 hours, the inert gas or the like continues to flow during that time, and the manufacturing cost is remarkably increased.

Moreover, oxygen inside the bag material is consumed by placing and heating a plurality of stacked metal plate materials and oxygen-consuming charcoal in a titanium-containing stainless steel bag material having a thickness of about 0.03 mm. It is possible to prevent oxidation.
However, since this method is to prevent the inside of an expensive and difficult-to-obtain titanium-containing stainless steel bag material from being oxidized, the manufacturing cost is extremely high.

  Therefore, the present invention proposes a technique for manufacturing a metal thermoformed body that can eliminate the above problems and can suppress such oxidation in a metal thermoformed body that is susceptible to oxidation when heated in the atmosphere. For the purpose. It is another object of the present invention to propose a method for producing a patterned metal plate material that can be diffused and bonded securely and inexpensively and can form a beautiful pattern rich in visual interest.

The present invention has been proposed in view of the above, and a silver powder-containing composition containing silver powder and an organic binder is provided on the exposed surface of a heated object that contains a metal that is oxidized by heating in the atmosphere. a step of covering, a step of thermoforming by the the coated device under heat treated is heated in air, the metal heat molded body obtained after heating by the atmosphere, the heated together silver powder And a step of removing at least a part of the contained composition.
By configuring the invention in this manner, in the step of heating the object to be heated, the silver powder-containing composition is sintered to form a coating that densely covers the exposed surface, thereby preventing oxygen from entering. Furthermore, when the organic binder is thermally decomposed, the vicinity of the exposed surface becomes a reducing atmosphere, and oxidation proceeding from the exposed surface to the inside can be suppressed.
In addition, as a method for coating the exposed surface of the object to be heated with the silver powder-containing composition, a method of applying the paste-like silver powder-containing composition with a brush or a brush is common, but is not limited thereto. It is not a thing.

The “heated object containing a metal that is oxidized when heated in the atmosphere” of the present invention is a material in which a plurality of metal plates are overlapped and diffusion-bonded, copper containing copper powder or copper alloy powder Like a plastic composition or a copper powder-containing paste composition, it is susceptible to oxidation when subjected to heat treatment such as diffusion bonding, firing, sintering, etc. in the atmosphere, and consists of only metal or metal and organic matter, There are various things such as those formed with other things such as inorganic substances. Therefore, this heat treatment is understood in the broadest sense in the present invention.
In addition, “thermoforming” of the present invention means diffusion bonding, firing, sintering, etc. caused by heat treatment. This includes the part that burns or undergoes a chemical change, and is understood in the broadest sense in the present invention.

The present invention is the method described above, wherein the object to be heated is in a state where a plurality of metal plates having different color tones are stacked and pressed in the overlapping direction, and the exposed surface is at least the A method for producing a metal thermoformed body (that is, a metal plate material for pattern formation), characterized in that it refers to the periphery of a seam of a plurality of metal plates, and the thermoforming means that the seam is diffusion bonded. I also propose.
According to the JIS definition, diffusion bonding refers to “using the diffusion of atoms generated between the bonding surfaces by pressing the base material in close contact and applying pressure to the extent that plastic deformation does not occur as much as possible under temperature conditions below the melting point of the base material. To join ". According to the inventor's knowledge, the most important conditions in diffusion bonding are heating temperature, pressing and contacting, and oxidation prevention. Among these, regarding setting of heating temperature and pressing and contacting, respectively. In the end, it is important how easily and reliably antioxidation can be carried out. As this technique, the present invention has been found.

In the above-mentioned prior art, the method of applying a mixture of powder with charcoal to the periphery of the metal plate by superimposing metal plates is a clay shape immediately after application or immediately before entering the heating furnace. When charcoal burns in the heating furnace, oxygen is consumed, but the applied shape cannot be maintained, so that oxygen penetrates and the metal plate is oxidized, resulting in insufficient diffusion bonding.
On the other hand, in the present invention, since the seam periphery between the plurality of metal plates overlapped in the heated object to be heated is covered with the silver powder-containing composition, the organic binder burns in the heating furnace and oxygen is generated. Since the silver powder that is consumed and the remaining silver powder sinters and maintains the applied shape, a metal thermoformed body that is well diffused and bonded by preventing the entry of oxygen is obtained.
The obtained metal thermoformed body can be suitably used as a metal plate material for pattern formation. The removal of the silver powder-containing composition heated together from the obtained metal thermoformed product can be easily peeled off with a cutter blade or a polishing spatula, etc., but the post-process (pattern of the obtained metal thermoformed product In the initial step of producing the metal plate material for forming) or in the initial step of producing the patterned metal plate material, the metal thermoformed body is usually peeled off by the impact during the process of rolling or rolling with a hammer.

The present invention is the metal according to the above method, wherein the plurality of metal plates pressed and overlapped are aligned so that the directions rolled before the metal plates overlap are the same direction. A method for producing a thermoformed body is also proposed.
Usually, the metal plate to be used is rolled into a plate shape from a lump such as a square bar or a round bar with a roller or the like. By this roller rolling process, the metal plate used has anisotropy with respect to strength. That is, it becomes difficult to extend with a roller in the direction different from the direction extended with the roller. If you try to extend it forcibly, the bullion may break. Therefore, for example, a little mark is made with a thread saw on one side of each metal plate so that it matches the direction rolled before each metal plate is overlapped, and the mark faces the same direction. It is desirable to align and stack the metal plates so that the directions rolled before the metal plates overlap are the same. As a result, when the metal thermoformed body (that is, the metal plate for pattern formation) subjected to diffusion bonding is further rolled into a patterned metal plate material such as a grain metal, cracks are generated by rolling according to the marks attached thereto. You can avoid it.

In the present invention, a concave portion having an arbitrary shape is formed on the surface of a metal thermoformed body (that is, a metal plate for pattern formation) manufactured by the above method at a depth reaching at least a metal having a different color tone. A method for producing a patterned metal plate material is also proposed, which comprises performing an operation and an operation of rolling and flattening the surface on which the concave portion is formed to form a desired pattern.
This pattern metal plate manufacturing method is to form at least the concave portion and flatten the desired pattern to form a desired pattern. A known operation may be added.

The present invention is the method described above, wherein the object to be heated is a copper plastic composition containing copper powder or copper alloy powder, and the exposed surface is the surface of the copper plastic composition. The thermoforming also means that the copper or copper alloy of the copper plastic composition is sintered, and also provides a method for producing a metal thermoformed body.
Thereby, after shape | molding the copper plastic composition containing copper powder etc. to arbitrary shapes, the silver powder containing composition is coat | covered on the whole surface, and it will heat. As a result, the copper plastic composition is sintered in a state in which the formed arbitrary shape is maintained, and the surface is oxidized by forming a dense coating by sintering the silver powder-containing composition heated together. Is prevented. The removal of the silver powder containing composition heated from the obtained metal thermoformed body can be easily peeled off with a cutter blade or a polishing spatula.

In the heat-treated body formed by combining a noble metal plastic composition containing a noble metal powder selected from silver, gold, platinum or an alloy thereof and an organic binder, and the copper plastic composition, Only the exposed surface of the copper plastic composition is coated with a silver powder-containing composition containing silver powder and an organic binder. This is because the precious metal powder becomes a sintered product without being oxidized even if the precious metal plastic composition is heated in the air or the organic binder is burned. Further, when the noble metal plastic composition is coated with the silver powder-containing composition and heated, in the case of a noble metal plastic material of the same quality as the silver powder-containing composition, the noble metal of the noble metal plastic composition and the silver of the silver powder-containing composition This is because it becomes difficult to peel only the silver powder-containing composition heated together .

In the method described above, the heat-treated body is obtained by attaching a copper powder-containing paste composition containing copper powder or copper alloy powder to a part or all of a surface of a member to be decorated. The exposed surface refers to the surface of the copper powder-containing paste composition adhered thereto, and the thermoforming is performed on the member to be decorated with the copper powder or copper alloy powder of the copper powder-containing paste composition. There is also provided a method for producing a metal thermoformed product, characterized in that it is sintered.
Thereby, a silver powder containing composition is coat | covered and heated on the copper powder containing paste composition made to adhere to the surface of a decorating member. Thus, a copper powder-containing paste composition, the silver powder-containing composition that is heated together is prevented is the surface oxide and dense film by sintering, the sintering while maintaining the table surface. Moreover, the removal of the said silver powder containing composition heated together from the obtained metal thermoforming body can be easily peeled with a cutter blade or a polishing spatula.

The decorative member includes ceramic materials such as ceramics and glass, noble metal plates such as silver and gold or sintered noble metals, ferrous metal plates such as ferritic or austenitic stainless steel, copper, Cu- Examples thereof include inorganic materials such as a metal plate or a sintered body that are easily oxidized by heating in the air, such as a Zn-based alloy, a Cu-Sn-based alloy, a Cu-Au-based alloy, and a Cu-Al-based alloy. Naturally, when a metal plate that is easily oxidized by heating in the atmosphere is used as the member to be decorated, not only the surface of the copper powder-containing paste composition but also the silver powder-containing composition on the member to be decorated. It is preferable to coat and perform thermoforming.
The copper sintered film of copper or copper alloy sintered on the surface of the decorative member is an oxide film with a stewed liquid prepared appropriately, for example, a blend composition of patina, copper sulfate, alum and water depending on the difference in its components The simmering coloring which artificially forms and colors can be performed. The color to be colored varies depending on the component ratio of copper, for example, copper is cinnabar red, bronze is bluish black, quarter (alloy 75% copper, silver 25% alloy) is gray, and brass is gold brown . Therefore, various copper powder-containing paste compositions with different compositions of copper powder or copper alloy powder are attached to the surface of the decorated member so as to form a pattern, and then sintered to perform conventional simmering coloring. By this, the pattern which has various desired shades can be formed, and a pattern can be formed on the surface of a to-be-decorated member like a paint.

The present invention is characterized in that, in the above method, the silver powder contains 30 to 70% by weight of a powder having an average particle size of 2.2 to 3.0 μm, and the balance is a powder having an average particle size of 5 to 20 μm. A method of manufacturing a metal thermoformed body is also proposed.
The silver powder to be used is not particularly limited in particle size, but it is desirable to use a combination of the above-mentioned relatively small particle size silver powder and relatively large particle size silver powder.

In the above method, the present invention includes an organic binder containing 0.02 to 3.0 wt% starch and 0.02 to 3.0 wt% water-soluble cellulose resin in a solid content excluding water. Also proposed is a method for producing a metal thermoformed product.
The organic binder to be used is not particularly limited, but it is desirable to use a combination of the above two types of binders.

  In the method described above, the water-soluble cellulose resin is one or more selected from methylcellulose, carboxymethylcellulose, hydroxypropylcellulose, and hydroxypropylmethylcellulose. I also propose.

  The present invention also proposes a metal thermoformed article produced by the above method.

Although the method for producing a metal thermoformed product of the present invention is a very simple method, it is possible to obtain a metal thermoformed product in which oxidation at the time of heat forming in the atmosphere (that is, in the air) is suppressed. That is, a high-quality metal thermoformed product can be obtained without adjusting the heating atmosphere to be inert (or reducible).
Further, in the method for producing a metal sheet for pattern formation as the metal thermoformed article of the present invention, the joint periphery of the plurality of metal plates is silver powder-containing composition in a state where the plurality of stacked metal plates are pressed and brought into contact with each other. Since it is covered with an object and heated, and the most important condition in diffusion bonding is to prevent oxidation from the periphery by covering with this silver powder-containing composition, it is inexpensive, easy and reliable diffusion bonding A beautiful pattern can be formed by subsequent processing on the surface.
Further, unlike the above-described conventional method, it does not require extremely difficult work or high skill, and does not require expensive equipment, and can be implemented using inexpensive equipment and materials in the air. Therefore, the practical value is extremely high.

  In addition, a metal thermoformed product obtained by superimposing a plurality of metal plates having different colors (that is, a metal plate material for pattern formation) has a silver sintered body adhering to the joint edge of the superposed metal plates. Since each metal plate is sufficiently diffusion-bonded, the metal plate does not peel off or fall apart in subsequent processing.

Furthermore, the method for producing a patterned metal plate material of the present invention uses a metal thermoformed body (that is, a metal plate material for pattern formation) that is diffusion-bonded inexpensively, easily and reliably as described above. It contributes greatly to the development and enlightenment of seed technologies. In particular, it can be widely provided as a material in the field of decorative processing and design for various crafts and accessories.
In addition, the method for producing a metal thermoformed body of the present invention, in which the heat-treated body is formed from a copper plastic composition containing copper powder or copper alloy powder, is the exposure of the copper plastic composition formed into an arbitrary shape. By simply coating the surface with a silver powder-containing composition and heating, the copper or copper alloy of the copper plastic composition is suppressed from being oxidized, and the copper or copper alloy is sintered to maintain an arbitrary shape. Sintered products can be produced easily, without the need for extremely difficult operations and advanced skills, and without expensive equipment, which can be carried out in the air using inexpensive equipment and materials. Is. Therefore, it can be easily sintered while suppressing the oxidation of the copper plastic composition while maintaining the shaped shape, so it is widely used in the field of decorative processing and design for various crafts and accessories. This is a method for producing a metal thermoformed product.

Further, the heat-treated body is a metal thermoforming of the present invention in which a copper powder-containing paste composition containing a copper powder or a copper alloy powder is attached to part or all of the surface of a member to be decorated. The body manufacturing method is that the copper powder or copper alloy of the copper powder-containing paste composition is oxidized simply by coating the exposed surface of the adhered copper powder-containing paste composition with the silver powder-containing composition and heating. Sintered copper or copper alloy can be easily sintered on the surface of the decorated member by sintering copper or copper alloy to maintain an arbitrary shape, requiring extremely difficult work and high skill Therefore, more expensive equipment or the like is not necessary, and can be implemented using inexpensive equipment and materials in the air.
By attaching various copper powder-containing paste compositions in which the composition of the copper powder or the copper alloy powder is changed to form a pattern on the surface of the member to be decorated, sintering it and performing the above-mentioned simmering coloring, A pattern having various desired shades can be formed, so that a pattern can be formed on the surface of the member to be decorated as if it were a paint. Therefore, it is possible to easily sinter while suppressing the oxidation of various copper powder-containing paste compositions with a pattern formed on the surface of the member to be decorated. In the field of design, this is a method for producing a metal thermoformed article that can be widely used.

(A) The perspective view which shows the metal plate material for pattern formation of the state taken out from the heating furnace in Example 1, (b) It is the sectional drawing. (A) It is a disassembled perspective view which shows the state before apply | coating the silver paste in Example 2, (b) It is sectional drawing which shows the metal plate material for pattern formation of the state taken out from the heating furnace.

Explanation of symbols

1 for forming a pattern metal plate 2 copper 3 silver plate 4 supporting plate 5 wire 6 silver paste powder 8 was heated in a sign 7 preparative 9 square type steel 10 insertion hole 11 bolt 12 fastening nuts

<First Embodiment>
First, the metal plate which is a raw material used for the metal thermoforming body which concerns on 1st Embodiment of this invention, and a silver powder containing composition are demonstrated.
The metal thermoformed body according to the first embodiment is overlapped in a state where a plurality of metal plates having different color tones are pressed, and a silver powder-containing composition is applied (coated) to the peripheral edges of the joints of these metal plates. It can be obtained by thermoforming.
This coated silver powder-containing composition is formed into a film on the periphery of the seam by heating to block the atmosphere. The coating with the silver powder-containing composition is not limited to the peripheral edge of the joint, and it is preferable that the entire exposed surface that may be oxidized by contact with the atmosphere is coated.

The metal plate (base metal) used in the first embodiment is a copper plate, a silver plate, or red copper (shadow, containing 3% of gold in copper), one-quarter (shibuichi, containing a quarter of silver in copper, “Irogane” such as brass, copper alone, 18 gold, etc., or stainless steel plate can also be used, and the number of sheets is particularly limited However, dozens of metal plates are overlapped and used.
Moreover, as this metal plate, the thing which has not annealed is used suitably. Usually, a crystal material undergoes plastic deformation by sliding in the direction in which atoms are arranged most closely. On the slip surface, strain is concentrated on the boundary line between the already slipped area and the area that has not slipped. This boundary line is called dislocation. The dislocation is performed by reducing the density by high-temperature annealing or thermal cycle annealing. As diffusion of atoms in a solid, lattice or body diffusion, surface diffusion, grain boundary diffusion, and dislocation diffusion can occur in parallel. In dislocation diffusion, atoms diffusely move along dislocation lines. Therefore, as the metal plate to be used, those having a high density of dislocation lines that have not been annealed are preferably used because they can be easily diffusion bonded. Further, when the surface of the metal plate is roughened with a paper file or the like, dislocations further increase on the surface.
Usually, the metal plate to be used is rolled into a plate shape from a lump such as a square bar or a round bar with a roller or the like. By this roller rolling process, the metal plate used has anisotropy with respect to strength. That is, it becomes difficult to extend with a roller in the direction different from the direction extended with the roller. If you try to extend it forcibly, the bullion may break. Therefore, for example, a little mark is made with a thread saw on one side of each metal plate so that it matches the direction rolled before each metal plate is overlapped, and the mark faces the same direction. It is desirable to align and stack the metal plates so that the directions rolled before the metal plates overlap are the same. Accordingly, when the metal plate for pattern formation that has been diffusion-bonded is further rolled into a pattern metal plate material such as a grain metal, it is possible to prevent cracking by rolling in accordance with the mark provided.

These metal plates do not necessarily have a uniform thickness, and metal plates having different thicknesses may be used. In general, a square (rectangular) metal plate is used, but is not particularly limited.
Furthermore, it is desirable to remove these oxide films or perform a degreasing treatment on these metal plates prior to production.
The removal of the oxide film on the surface of the metal plate is not particularly limited. For example, there is a method of removing the oxide film in dilute sulfuric acid. Since this oxide film hinders diffusion bonding, it is desirable to quickly put it in water so as not to touch air when taking out from dilute sulfuric acid. In particular, copper is easy to oxidize. Also, the degreasing treatment is not particularly limited. For example, there is a method of putting a metal plate in a cleaning solution containing a neutral detergent, performing ultrasonic cleaning, and degreasing. After degreasing, wash thoroughly with water and rinse with detergent.

The silver powder-containing composition used in the present invention is a mixture of silver powder and an organic binder, and becomes a paste or clay depending on the amount of water or solvent added.
The silver powder is preferably composed of at least one of silver powder and silver alloy powder, and those having a particle diameter of 1 to 100 μm (micrometer) occupy 90% or more of the whole. In particular, those having an average particle size of 5 to 30 μm (micrometer) and appropriately distributed are desirable. This is because small particles are mixed between large particles, and the fine particles fill the gaps between the large particles, whereby a sintered body (layer) having a high density and thus a low shrinkage can be obtained.
In particular, it is more preferable that the silver powder contains 30 to 70% by weight of powder having an average particle size of 2.2 to 3.0 μm, with the balance being 5 to 20 μm.

The organic binder is not particularly limited, but at least water-soluble cellulose resin, British gum, xanthan gum, dextrin, dextran, pullulan, sodium alginate, polyerylene oxide, polypropylene oxide, polyvinyl pyrrolidone, polyethylene glycol, polyacrylic It is preferable to use one or more selected from acids, polyacrylic acid esters, water-soluble acrylic resins, urethane resins, thermoplastic resins, and oil-based binders.
Among the organic binders, the water-soluble cellulose resin and the British gum serve to impart plasticity and improve the adhesion to the metal plate (periphery). Polyethylene oxide functions to give high viscosity at a low concentration and to improve adhesiveness in liquid form. Glycerin provides moderate water retention. Sodium alginate gives moderate water retention like glycerin, but also contributes to the adhesion improving action. The polyacrylic acid ester and the polyacrylic acid serve to strengthen the adhesiveness. The oily binder is preferably a polymer organic binder such as an acrylic resin.

As an organic binder, it is particularly desirable to use 0.02 to 3.0 wt% starch and 0.02 to 3.0 wt% water-soluble cellulose resin in terms of solid content excluding water. Among these, the water-soluble cellulose resin serves to impart plasticity and improve adhesion to a metal plate as described above, but starch increases the dry strength when the silver powder composition is dried. However, when only starch is used as the organic binder, cracking of the dough tends to occur during coating. Therefore, these problems can be solved by using a water-soluble cellulose resin together. As described above, starch contains 0.02 to 3.0 wt% in terms of solid content excluding water in the clay composition, but if less than 0.02 wt%, it tends to cause insufficient strength during drying. Become. On the other hand, if it exceeds 3 wt%, the fabric cracks easily occur during coating. Also, the shrinkage rate increases. On the other hand, as described above, the water-soluble cellulose resin also contains 0.02 to 3.0 wt% in terms of solid content excluding water. If it is less than 0.02 wt%, the effect of imparting plasticity is sufficient. It is not demonstrated. When it exceeds 3 wt%, the shrinkage rate increases. As such a water-soluble cellulose resin, methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose and the like are used, which are dissolved in water and used.
As the amount of the organic binder composed of the starch and the water-soluble cellulose resin, the total amount of the starch and the water-soluble cellulose resin is preferably in the range of 0.1 to 4 wt%. If the amount of the organic binder is less than 0.1, it is difficult to maintain the shape. In addition, there is a disadvantage that the strength after coating and drying is weakened. When the amount of the organic binder exceeds 4 wt%, shrinkage increases and cracks are likely to occur. Therefore, the amount of the organic binder is suitably 0.1 to 4 wt%.

  The required amount of water is added. If the amount is too small, it becomes hard and difficult to apply. If the amount is too large, it tends to enter from the periphery of the metal plate by capillary action. This silver powder-containing composition can be prepared in the form of clay, paste, or slurry depending on the water content, but it is preferably applied as a paste with a brush or brush.

Bi, Se, Sb, In, Sn, Zn powder or alloy powder thereof may be added as a sintering accelerator.
Furthermore, you may add the metal compound powder or glass powder chosen from lead carbonate, lithium carbonate, zinc oxide, phosphoric acid, sodium carbonate, vanadium oxide, sodium silicate, phosphate etc. as an adhesive improvement agent.
Further, for the purpose of improving plasticity, a network polymer formed by condensation of structural units having a skeleton of phenylpropane such as lignin, glycerin, diglycerin, isoprene glycol, 1,3 butylene glycol, liquid paraffin, alcohols, Fats and oils, phthalic acid, phthalic acid-n-dioctyl, phthalic acid-n-dibutyl, and polyvinyl alcohol may be added, and a surfactant and a surfactant may be added as necessary.

Next, a method for manufacturing a sintered metal body according to the first embodiment will be described along a manufacturing procedure.
First, as a first step, a plurality of different metal plates are overlapped and pressed in the overlapping direction to contact each other.
Next, as a second step, in a state where the stacked metal plates are pressed and brought into contact with each other, the periphery of the joint is covered with the above-described silver powder-containing composition and dried.
Subsequently, as a third step, heating is performed at a temperature equal to or lower than the melting point of the stacked metal plates in the atmosphere, and the stacked metal plates are diffusion bonded.

[First step]
A plurality of metal plates prepared as described above are overlapped and pressed in the overlapping direction to contact each other. When superposing, the metal plates are stacked so as to coincide with the direction rolled before superposition. For example, there is a method of making a small mark with a thread saw on one side surface of each metal plate so as to coincide with the rolled direction, and aligning and superimposing the marks so as to face the same direction. It is not a thing. Accordingly, when the metal plate for pattern formation that has been diffusion-bonded is further rolled into a pattern metal plate material such as a grain metal, it is possible to prevent cracking by rolling in accordance with the mark provided.
As a method of pressing the stacked metal plates in the stacking direction and bringing them into contact with each other, it is necessary to perform by a method in which the pressing force is not removed even during heating in the third step described later.
(A) For example, a method of tightening with a bolt and nut sandwiching a metal plate overlapped using thick steel or square steel from above and below,
(B) There is a method of maintaining the pressing force using a wire or the like in a state where the stacked metal plates are pressed and contacted.
The method (A) is a method in which a thick steel material or square steel material sandwiched is put into a heating furnace in a third step described later, and is not particularly limited, but a patterned metal having a relatively large area. It is suitable for creating a plate material.
In the method (B), for example, a jig such as a vise is used to press in the overlapping direction, but the jig tries to maintain the pressing force with a wire or the like when the jig cannot be put into the heating furnace. Although it does not specifically limit, It is suitable when creating a pattern metal plate material with a comparatively small area.

In the method (A), a thick steel material or square steel material is applied in advance so that the uppermost layer and the lowermost metal plate in contact therewith are not joined during heating in the third step. It is desirable to keep it.
In addition, when sandwiched metal plates are sandwiched between thick steel and square steel materials and tightened with bolts and nuts from above and below, the metal is laminated with adhesive tape attached to the periphery for the purpose of temporary fixing. You may hold | maintain so that a board may be wrapped.

In the method (B), since the wire is used as described above, the wire is placed above the uppermost metal plate and below the lowermost metal plate so that the wire does not bite into the uppermost and lowermost metal plates. It is desirable to provide a thick support plate. The material of the support plate is not particularly limited. For example, when a copper plate or a silver plate is selected as the metal plate, an iron material having a close expansion coefficient is more suitable than stainless steel. In addition, as in the method (A), it is desirable to apply powder or the like to the support plate in advance so that the support plate and the metal plate are not joined.
Also, in this method, as described above, for example, a jig such as a vise is used to press in the stacking direction, but in order to maintain the pressing force, the stacked metal plates are wound in advance with a wire or the like. After a simple fastening and tightening, it is firmly tightened and pressed with a jig such as a vise, and this state is maintained with a wire or the like. In addition, you may carry with the adhesive tape in the said (A) method before winding up with a wire etc. so that the metal plate which overlap | superposed may not fall apart.

[Second step]
In the case where the adhesive tape is pasted on the periphery of the joint of the metal plates superposed in the first step, the adhesive tape is removed, and the silver powder-containing composition prepared in advance, preferably a paste-like silver powder-containing composition, is removed. Apply to the periphery of the seam and dry. As an application quantity, it applies so that it may become thickness 0.1-0.5 mm after drying.
As described above, the silver powder-containing composition is preferably applied as a paste to the periphery of the joint with a brush or a brush. However, if the viscosity is too low, the silver powder-containing composition is formed from the periphery into the metal plate and the metal plate. May enter a minute gap between the two and hinder diffusion bonding. In addition, even when the pressing by the first step is not sufficient, the silver powder-containing composition may enter between the metal plate and prevent diffusion bonding, so it is important to press firmly. is there.
Further, the drying after the application may be allowed to stand at room temperature or may be performed using preheating of a heating furnace such as an electric furnace.

[Third step]
In the air (in the atmosphere), heat treatment is performed at a temperature equal to or lower than the melting point of the stacked metal plates, and the stacked metal plates are diffusion bonded.
As a heating method, a method of heating in a heating furnace such as a kiln or an electric furnace is preferable. Moreover, although heating temperature changes with kinds of used metal plate, the heating temperature is 600-900 degreeC from the characteristic of a silver powder containing composition, Preferably it is 730-800 degreeC, Heating time is 30 minutes-20 hours, Preferably 3 What is necessary is just to heat for 10 hours.
In this heating state, the silver powder occupying most of the silver powder-containing composition applied in the second step is sintered, a slight residual water is evaporated, and a small amount of organic binder is burned out (oxidized). However, since oxygen is consumed at that time, the periphery of the metal plate covered with the silver powder-containing composition is in an antioxidant state, and good diffusion bonding is achieved.
In the method (A) in the first step, the thick steel material and the square steel material are put together in the heating furnace. Therefore, after this third step, the thick steel material and the square steel material are removed and each metal plate is removed. To obtain a metal thermoformed body having diffusion bonded.
In the method (B) in the first step, the metal plate is diffused by removing the wire and the support plate after the third step because it is put in the heating furnace while being wound with a wire or the like. A metal thermoformed body joined is obtained.

The metal thermoformed product obtained by the method for producing a metal thermoformed product of the present invention is a metal plate material for pattern formation, and the silver powder-containing composition sintered and densified by the heating for diffusion bonding is provided. It is in a state on the outer surface. The removal from the metal thermoform of the silver powder-containing composition heated together can be easily peeled off with a cutter blade or a polishing spatula after cooling, but when removing the above-mentioned wire or support plate, Metal thermoforming usually performed in the post-process (finishing process of the metal plate for pattern formation) that is partly peeled off naturally and performed as needed, or in the initial process of producing the pattern metal plate described below When the body is rolled with a roller or stretched with a hammer, it is naturally peeled off by the impact.
By using the pattern forming metal plate obtained by the method for manufacturing a metal thermoformed body of the present invention, a pattern metal plate having a desired pattern formed by the following various methods can be manufactured.
For example, on the surface of the metal plate for pattern formation, an operation of forming a concave portion of an arbitrary shape at a depth reaching at least a metal having a different color tone, and rolling and flattening the surface on which the concave portion is formed To form a desired pattern.

As a specific example, after a metal plate for pattern formation is stretched with a hammer etc. with a burner, etc., when it becomes hard, it is cast with a hammer with appropriate heating, and then a drill, a metal file, or various engraving swords Or the like is used to form a desired concave portion having a depth that reaches at least a metal having a different color tone. For example, a circular concave portion is formed in a drill, and a strip-shaped concave portion is formed in a metal file. The pattern formed is completely different depending on the arrangement and combination of these concave portions. Even when this desired pattern is formed, for example, a combination of silver and copper, it is interesting in color, and even if copper is oxidized and blackened, the contrast becomes remarkable and interesting.
Thereafter, a color-raising (coloring) treatment, a surface protection treatment, or the like may be performed as necessary. As a color raising (boiled coloring) treatment, the patterned metal plate is polished with a whetstone, park charcoal, park charcoal powder, etc., and degreased as usual. Depending on the composition, the composition of the patina, copper sulfate, alum and water may be changed as appropriate. In this color-raising process, the copper turns brown and turns red when cooked. It is known that bronze turns into a lacquer-like black color when boiled. Moreover, you may make it pass through the process process which processes a pattern metal plate material into ornaments, such as a ring, before these color raising processes.

As another example of pattern formation, the pattern forming metal plate is subjected to coining by applying it to a coining roll having irregularities on the peripheral surface to form a plurality of linear concave portions on the surface of the pattern forming metal plate. . Convex parts other than the concave part may be removed by surface grinding. In this method using coining, a pattern-formed plate material in which metal parts having different color tones appear in parallel is obtained.
In this method, a coining press plate may be used instead of the coining roll, and a complicated pattern can be formed by designing various coining surfaces of the coining roll or the coining press plate.
When such a mechanical process called coining is used, even complicated patterns can be mechanically reproduced, so it may be applied to mass production. It may be used to form an arbitrary concave portion (that is, the coining process may be applied as a base process).

As another example of pattern formation, masking is performed on a desired portion of the surface of the metal plate for pattern formation, and after removing the surface of the unmasked portion with a corrosive solution, the surface is removed by removing the masking. Roll this until flat. In a method using such masking (etching in a broad sense), a pattern-formed plate material having a different color tone between a desired portion and the other portion (background portion) can be obtained.
In this method, when performing masking, a known scribing-peeling method, photoengraving method or the like may be used. In this case, a maskant (chemical resistant film) or a photosensitive resin is used as the masking. . Moreover, as a corrosive liquid, nitric acid, hydrochloric acid, sodium cyanide, aqua regia, etc. are used suitably according to the kind of used metal plate. Further, when removing the masking, a method of immersing in an organic solvent, a method of immersing in a caustic soda solution or the like if the masking is a photosensitive resin are appropriately employed.
When such chemical means of etching is used, a physical pattern for forming the concave portion using the above-described drill or metal file is not necessary, so that even a worker with weak arm strength or the like can form a desired pattern. it can.

Second Embodiment
Next, a metal thermoformed body according to the second embodiment of the present invention will be described.
The metal thermoformed body according to the second embodiment forms a copper plastic composition containing copper powder or copper alloy powder into an arbitrary shape, and silver powder is formed on the entire surface (exposed surface exposed to the atmosphere) of this shaped body. It is obtained by applying (coating) the containing composition, heating it under the atmosphere, and then removing the coating of the silver powder-containing composition.

Since the silver powder containing composition used in 2nd Embodiment is the same as what was used in 1st Embodiment, detailed description is abbreviate | omitted.
The copper plastic composition used in 2nd Embodiment contains the copper powder which consists of at least one among copper powder and copper alloy powder, and an organic binder. Although copper powder and an organic binder are explained in full detail below, various copper plastic compositions are already marketed and you may make it use it.

  The copper powder is not particularly limited, but is preferably a powder having an average particle size of 20 μm or less, a maximum of about 100.0 μm, and a minimum of about 0.3 μm. Although there is no designation, it is preferred that the particles have a nearly spherical shape.

  The organic binder is not particularly limited, but cellulose binders such as methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, carmellose (carboxymethylcellulose), alginic binders such as sodium alginate, starch Polysaccharide binders such as wheat flour, British gum, xanthan gum, dextrin, dextran and pullulan, animal binders such as gelatin, vinyl binders such as polyvinyl alcohol and polyvinylpyrrolidone, acrylics such as polyacrylic acid and polyacrylate Binder, polyethylene oxide, polypropylene oxide, other resin binders such as polyethylene glycol, etc. Preferably selected and used more binders. In the cellulose binder, it is most preferable to use a water-soluble cellulose binder.

Further, if necessary, the following substances may be added to the organic binder as additives. That is, additives include organic acids (oleic acid, stearic acid, phthalic acid, palmitic acid, sepacic acid, acetylcitric acid, hydroxybenzoic acid, lauric acid, myristic acid, caproic acid, enanthic acid, butyric acid, capric acid, citric acid. Acid), organic acid esters such as phthalic acid-n-dioctyl, phthalic acid-n-dipyl (methyl group, ethyl group, propyl group, butyl group, octyl group, hexyl group, dimethyl group, diethyl group, isopropyl group, isobutyl Organic acid ester having a group), higher alcohol (octanol, nonanol, decanol), polyhydric alcohol (glycerin, arabit, sorbitan, diglycerin, isoprene glycol, 1,3 butylene glycol), ether (dioctyl ether, didecyl ether) Bones, phenylpropane Or a mixture of two or more selected from the group consisting of lignin, liquid paraffin, and oils and fats (for example, olive oil rich in oleic acid). . These additives are added for the purpose of improving plasticity or added for the purpose of preventing the copper plastic composition from adhering to the hand during modeling. Furthermore, the above additives, lignin and glycerin, provide appropriate water retention.
Furthermore, surfactants such as anionic, cationic and nonionic are listed as additives. The surfactant has an effect of improving the mixing property between the metal powder and the binder and an effect of improving water retention.

Among the organic binders, the water-soluble cellulose binder serves to impart plasticity. Of the organic binders, polyethylene oxide has a function of improving the adhesion in a liquid state by giving a high viscosity at a low concentration. Moreover, although sodium alginate gives moderate water retention like the said glycerol, it contributes also to the contact | adherence improvement effect | action. Furthermore, the polyacrylic acid ester and the polyacrylic acid serve to strengthen the adhesiveness.
As the organic binder, it is preferable to use 0.02 to 3.0 wt% of starch and 0.02 to 3.0 wt% of a water-soluble cellulose binder in terms of solid content excluding water. Among them, the water-soluble cellulose binder serves to impart plasticity as described above, while starch serves to increase the dry strength when the copper plastic composition is dried. However, when only starch is used as the organic binder, fabric cracks are likely to occur during coating. Therefore, these problems can be solved by using a water-soluble cellulose binder together. As described above, this starch contains 0.02 to 3.0 wt% in terms of solid content excluding water in the copper plastic composition, but if it is less than 0.02 wt%, the strength is insufficient at the time of drying. When it exceeds 3.0 wt%, the material is liable to crack during coating, and the shrinkage rate increases. On the other hand, as described above, the water-soluble cellulose binder also contains 0.02 to 3.0 wt% in terms of solid content excluding water. If it is less than 0.02 wt%, the effect of imparting plasticity is sufficient. However, if it exceeds 3.0 wt%, the shrinkage rate increases. As such a water-soluble cellulose-based binder, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, or the like is used, which is used after being dissolved in water.

As the amount of the organic binder in the copper plastic composition using the starch and the water-soluble cellulosic binder as the organic binder, as a more preferable mode, the total amount of the organic binder is 0 in terms of solid content excluding water. Desirably, it is within the range of 1 to 4 wt%. In this case, if the amount of the organic binder is less than 0.1 wt%, it is difficult to obtain a homogeneous copper plastic composition. In addition, there is a disadvantage that the strength after coating and drying is weakened. When the amount of the organic binder exceeds 4 wt%, the shrinkage rate increases and cracks are likely to occur. Therefore, the amount of the organic binder is desirably 0.1 to 4 wt%.
When polyethylene oxide is used, it is desirable to use polyethylene oxide having a molecular weight of 100,000 to several million within the range of 0.1 to 3 wt%.
Moreover, when using surfactant, it is desirable to exist in the range of 0.03 to 3 wt%, and when using fats and oils, it is desirable to be within the range of 0.1 to 3 wt%.

Water should be added in the required amount. If it is too small, it becomes hard and difficult to form, and if it is too much, the shape cannot be maintained. This copper plastic composition can be prepared in the form of clay, paste or slurry depending on the water content.
In the preferred composition, the powder of copper or copper alloy is 75 to 99 wt%. However, if the amount is too small, the shrinkage becomes large and the sintering is disturbed. If the amount is too large, the organic binder and water are correspondingly reduced. The ratio is reduced, which hinders modeling.

Next, the manufacturing method of the metal sintered compact concerning 2nd Embodiment is demonstrated.
First, as a first step, a copper plastic composition containing the above-described copper powder and the like is shaped into a desired shape.
Next, as the second step, the above-described silver powder-containing composition is applied (coated) to the entire exposed surface of the shaped copper plastic composition, and is dried.

In the heat-treated body formed by combining a noble metal plastic composition containing a noble metal powder selected from silver, gold, platinum or an alloy thereof and an organic binder and the copper plastic composition, copper plasticity Only the exposed surface of the composition is coated with a silver powder-containing composition containing silver powder and an organic binder. This is because the precious metal powder becomes a sintered product without being oxidized even if the precious metal plastic composition is heated in the air or the organic binder is burned.
Furthermore, when the noble metal plastic composition is coated with a silver powder-containing composition and heated, in the case of a noble metal plastic composition of the same quality as the silver powder-containing composition, the noble metal of the noble metal plastic composition and the silver of the silver powder-containing composition are This is because it becomes easy to obtain an integrated sintered product, and it is difficult to peel only the silver powder-containing composition heated together .

Subsequently, as a third step, the copper plastic composition is heated to form a sintered body in the atmosphere, and the coating of the silver powder-containing composition on the surface is sintered.
As a heating method, a method of heating in a heating furnace such as a kiln or an electric furnace is preferable. Although the heating temperature varies depending on the type of copper or copper alloy used, the heating temperature is 600 to 900 ° C., preferably 730 to 800 ° C., and the heating time is 30 minutes to 20 in consideration of the characteristics of the silver powder-containing composition. What is necessary is just to heat for time, Preferably 3 to 10 hours. In the heating furnace, the organic binder in the copper plastic composition and the organic binder in the silver powder-containing composition are each burned to consume oxygen, and the copper powder or the copper alloy powder in the copper plastic composition is mutually exchanged. In addition to sintering, in the silver powder-containing composition, the silver powder sinters and maintains the applied shape, so that the sintered body of the copper plastic composition, which is a good metal thermoform, is prevented from entering oxygen. can get.

Then, as the fourth step, the silver powder-containing composition heated together is removed to obtain a sintered body (metal thermoformed body) of the copper plastic composition.
The removal of the silver powder containing composition heated from the sintered body of the obtained copper plastic composition can be easily peeled off with a cutter blade or a polishing spatula. This is presumably because the silver powder-containing composition and the copper plastic composition differ in the timing and speed of sintering, and the linear shrinkage rates due to sintering differ.
This sintered body is thermoformed in a reducing atmosphere by a combustion reaction of an organic binder contained in a copper plastic composition or a silver powder-containing composition while being shielded from air by the heated silver powder-containing composition. Therefore, it has good surface properties with suppressed oxidation.

<Third Embodiment>
Next, a metal thermoformed body according to a third embodiment of the present invention will be described.
In the metal thermoformed article according to the third embodiment, the copper powder-containing paste composition is attached to the surface of the member to be decorated, and the silver powder-containing composition is applied (coated) to the exposed surface on the atmosphere side. It is obtained by removing the coating of the silver powder-containing composition after heating under the condition of In addition, the copper powder containing paste composition to adhere may be a part of the surface of a to-be-decorated member, and may be the whole.

Since the silver powder containing composition used in 3rd Embodiment is the same as what was used in 1st and 2nd Embodiment, detailed description is abbreviate | omitted.
Decorated members used in the third embodiment include ceramic materials such as ceramics and glass, noble metal plates such as silver and gold, sintered noble metals, ferrous metal plates such as ferritic or austenitic stainless steel, etc. Furthermore, inorganic materials such as copper, Cu—Zn alloys, Cu—Sn alloys, Cu—Au alloys, Cu—Al alloys, etc., which are easily oxidized by heating in the atmosphere, such as metal plates or sintered bodies. Can be mentioned.

  The copper powder-containing paste composition used in the third embodiment is composed of copper powder made of at least one of copper powder and copper alloy powder, and Bi, Se, In, Sn, Zn and alloys thereof added as necessary. One or more types of sintering accelerators selected from the group consisting of lithium carbonate, zinc oxide, sodium phosphate, sodium carbonate, vanadium oxide, lead carbonate, and glass powder, which are added as necessary. It contains an inorganic powder composed of the above adhesion improver and an aqueous or oily binder.

In order to suppress shrinkage, the copper powder preferably has a uniform particle size and shape, and preferably has a particle size of 1 to 50 μm and a substantially spherical shape. Thereby, shrinkage | contraction of a copper powder containing paste composition is suppressed and thick coating is attained. This copper powder is contained in the inorganic powder in the range of 70 to 99 wt%. More preferably, it is contained in the range of 75 to 95 wt%.
Moreover, in order to promote sintering of a copper powder containing paste composition, you may use the said sintering promoter. The effect of the sintering accelerator is reduced when the particle size is too coarse, and shrinkage is increased when the particle size is too fine. Therefore, it is desirable that the particle size is 1 to 50 μm and the shape is almost spherical like the noble metal powder. . This sintering accelerator is contained in the inorganic powder in a range not exceeding 10 wt%, that is, in a range of 0 to 10 wt%. More preferably, it is made to contain in 0-5 wt%. If the added amount of the sintering accelerator exceeds 10 wt%, the sintered copper film and its surroundings may be discolored after sintering and the appearance may be impaired, and the decorative value is lowered.

Furthermore, you may use the said adhesive improvement agent in order to improve the adhesiveness with respect to the to-be-decorated member of a copper-powder containing paste composition. When the member to be decorated is made of a ceramic material or a metal sintered body, the adhesion improver is melted by heat to become vitreous and functions as a glaze to impart high adhesiveness.
When the particle size is too coarse, the effect of the adhesion improver is reduced. When the particle size is too fine, the shrinkage increases. Therefore, it is desirable that the particle size is 1 to 50 μm and the shape is almost spherical like the noble metal powder. In addition, these adhesion improvers are contained in the inorganic powder in a range of 0 to 10 wt% (in the case where both the glass powder and the other adhesion improvers described above are used in combination, the total amount is in the range of 0 to 20 wt%). Let More preferably, each is contained in the range of 1 to 5 wt%, and the total amount is in the range of 1 to 10 wt%. Exceeding this range may cause the copper powder to melt with the adhesion improver after sintering and diffuse into the adhesion improver in which the copper powder is melted, causing discoloration of the copper sintered film and its surroundings, which may impair the appearance. , The decorative value is reduced.

The aqueous binder is an aqueous solution of a high-molecular water-soluble organic binder having an aqueous solution concentration of 1 to 10% and 800 to 10000 cp, and is not limited in its formulation. For example, celluloses, dextrins, glycerin, etc. Can be used. In particular, by using dextrins, the water repellency of the glass surface or metal surface of the member to be decorated can be suppressed and the adhesion can be improved. Celluloses and glycerin impart water retention to the sintering composition, improve the usability, and contribute to improving the adhesion to the glass surface in the same manner as the dextrins. Dextrins are effective in the range of 1 to 5% in the aqueous binder, celluloses are 1 to 5%, and the rest are in the range of water and preservatives. In addition, any additive may be blended. This aqueous binder is added in a range of 5 to 30 wt% with respect to the total amount of the inorganic powder, to obtain a clay-like or mud-like sintering composition. If the added amount of the aqueous binder is less than 5 wt%, the mixture becomes so hard that it cannot be kneaded, and if it exceeds 30 wt%, the fluidity becomes too high and is not suitable for thick coating.

As the oil-based binder, a polymer organic binding material such as an acrylic resin is used. For example, squeegee oil (trademark) used for oil paints and the like is representative, but is not particularly limited, and any additive may be blended. Similarly to the aqueous binder, a high molecular organic binder exhibiting 800 to 10000 cp is used and added in the range of 5 to 30 wt% with respect to the total amount of the inorganic powder, and the clay-like or mud-like baked material is added. Let it be a ligation composition. If the amount of the oil-based binder added is less than 5 wt%, it becomes so hard that it cannot be kneaded, and if it exceeds 30 wt%, the fluidity becomes too high and is not suitable for thick coating.

The copper powder containing paste composition comprised in this way can be made into paste shape or clay shape, made to adhere to the surface of a member to be decorated by arbitrary shapes, and can be heated and sintered. And the sintered copper powder containing paste composition shows high adhesiveness (adhesion) property with respect to the surface of a member to be decorated.
Next, the manufacturing method of the metal thermoformed body which concerns on 3rd Embodiment is demonstrated.
First, as a first step, the above-described copper powder-containing paste composition is applied (attached) to a part / all of the surface of the member to be decorated so as to have a desired pattern.
Next, as a second step, the above-described silver powder-containing composition is applied (coated) to the entire exposed surface of the applied copper powder-containing paste composition, and this is dried.
Naturally, when a metal plate or sintered body that is easily oxidized by heating in the atmosphere is used as the decorated member, not only the surface of the copper powder-containing paste composition, but also the decorated member with silver powder. It is preferable to perform thermoforming by coating the containing composition.

Subsequently, as a third step, the copper powder-containing paste composition is heated to form a sintered body in the atmosphere, and a coating of the silver powder-containing composition is sintered on the surface thereof.
As a heating method, a method of heating in a heating furnace such as a kiln or an electric furnace is preferable. The heating temperature varies depending on the type of copper or copper alloy used in the copper powder-containing paste composition, but the heating temperature is 600 to 900 ° C., preferably 700 to 800 ° C. in consideration of the characteristics of the silver powder-containing composition. The heating time is 3 minutes to 1 hour, preferably 5 to 30 minutes. In the heating furnace, the aqueous or oily binder of the copper powder-containing paste composition and the organic binder in the silver powder-containing composition are each burned to consume oxygen, and the copper powder or copper in the copper powder-containing paste composition As the alloy powders sinter together, the silver powders in the silver powder-containing composition also sinter and maintain the applied shape, thus preventing the entry of oxygen and favorably containing the copper powder-containing paste on the decorated member A sintered body (metal thermoformed body) having a desired pattern shape of the composition is obtained.

Next, as the fourth step, the silver powder-containing composition heated together is removed to obtain a sintered body (metal thermoformed body) of the copper powder-containing paste composition formed on the decorated member.
The removal of the silver powder containing composition heated from the sintered body of the obtained copper plastic composition can be easily peeled off with a cutter blade or a polishing spatula. This is presumably because the silver powder-containing composition and the copper powder-containing paste composition differ in the timing and speed of sintering, and the linear shrinkage rates due to sintering differ.
This sintered body is shielded from air by the silver powder-containing composition heated together, and is heated in a reducing atmosphere due to the combustion reaction of the binder contained in the copper powder-containing paste composition or the silver powder-containing composition. Since it is molded, it has a good surface property in which oxidation is suppressed.

  The copper sintered film of copper or copper alloy sintered on the surface of the decorative member is an oxide film with a stewed liquid prepared appropriately, for example, a blend composition of patina, copper sulfate, alum and water depending on the difference in its components The simmering coloring which artificially forms and colors can be performed. The color to be colored varies depending on the component ratio of copper, for example, copper is cinnabar red, bronze is bluish black, quarter (alloy 75% copper, silver 25% alloy) is gray, and brass is gold brown . Therefore, various copper powder-containing paste compositions with different compositions of copper powder or copper alloy powder are attached to the surface of the decorated member so as to form a pattern, and then sintered to perform conventional simmering coloring. By this, the pattern which has various desired shades can be formed, and a pattern can be formed on the surface of a to-be-decorated member like a paint.

  In the above description, the metal thermoformed body according to the embodiment is obtained by diffusion bonding a stack of a plurality of metal plates having different color tones as a heat-treated body before heating, and copper containing copper powder. Three examples were shown, one that was sintered after shaping the plastic composition, and one that was sintered on the contact surface with the copper powder-containing paste composition attached to the surface of the decorated member. However, these are merely examples, and the present invention can be widely applied to metal thermoformed bodies that are susceptible to oxidation when heated in the atmosphere. That is, the influence of oxidation can be eliminated by coating the exposed surface of the object to be heated with the silver powder-containing composition, forming a film on the exposed surface by heat treatment, and blocking the atmosphere.

<When obtaining a metal thermoformed body from a heat-treated body in which a plurality of metal plates having different color tones are superimposed>
<Raw materials used>
The used metal plates were a copper plate and a silver plate, and prepared ones that were not annealed.
Copper plate ... 20x20x1mm ... 10 sheets Silver plate (Ag92.5%) ... 20x20x1mm ... 10 sheets Each copper plate and each silver plate have different strength by roller processing. In order to align the direction of the metal plates to be stacked, the copper plates and the silver plates were slightly marked on the side surfaces of the copper plates and the silver plates with the same direction.
Further, the surface of each metal plate was roughened with a paper file or # 300-position sponge file and then placed in 10% dilute sulfuric acid to remove the oxide film. Further, a metal plate was placed in a cleaning solution containing a neutral detergent, subjected to ultrasonic cleaning, degreased, washed well with water, and the detergent was washed away.
The silver powder-containing composition used was a water-soluble silver mixed powder (80 wt%) composed of 50% (40 wt%) silver powder having an average particle diameter of 2.5 μm and 50% (40 wt%) silver powder having an average particle diameter of 20 μm. As a binder, 0.5 wt% starch, 0.7 wt% cellulose, and the remainder as water were mixed well to obtain a silver paste (silver powder-containing composition).

<Example 1; Production 1 of metal plate material for pattern formation>
Match the metal plate (copper plate and silver plate) to the direction rolled into a plate shape as a preparation for use, mark a little with a saw on one side of each side, and point the mark in the same direction In order to hold the metal plate alternately while aligning the marks made of the thread saw, L steel material having a thickness of about 4 mm was cut and used as a support plate.
The support plate (iron plate) and the metal plate were coated with powder so as not to join.
Next, the stacked metal plates were fixed to a clamp, and an adhesive tape was attached to the side edge portion to fix the stacked metal plates.
Subsequently, the stacked metal plates sandwiched between the support plates were sandwiched between 2 mmφ wires, and the wires were fixed together in a vise and tightened firmly (actual pressure of about 12 kg / cm ² ).
In the tightened state, the wire was twisted and fixed with pliers to maintain the pressing force.
And after peeling off an adhesive tape, the silver paste (silver powder containing composition) of the said composition was apply | coated to the joint edge periphery of the piled metal plate with a brush, and the brush was reciprocated about 2 to 3 times and covered.
In this state, the silver paste was dried. The dry film thickness was 0.1 to 0.3 mm.
It was put together with the wire in an electric furnace and heated at 730 to 760 ° C. for 10 hours. The electric furnace was turned off, allowed to cool at room temperature, the wire was removed, and the upper and lower support plates (iron plates) were taken to obtain metal plates for pattern formation. FIG. 1 shows the state of the pattern forming metal plate taken out of the heating furnace.
1 is a metal plate for pattern formation, 2 is a copper plate, 3 is a silver plate, 4 is a support plate (iron plate), 5 is a wire, 6 is a mark, 7 is a powder, and 8 is heated together. Silver paste .

<Example 2; Production 2 of metal plate material for pattern formation>
Match the metal plate (copper plate and silver plate) to the direction rolled into a plate shape as a preparation for use, mark a little with a saw on one side of each side, and point the mark in the same direction The metal plates were stacked one after the other while aligning the marks made of thread saws, and the overlapping metal plates were fixed by sticking adhesive tape to the side edges.
A jig in which bolts are suspended on both ends of two square steel materials was prepared, and a metal plate overlapped between the square steel materials was sandwiched.
The square steel material and the metal plate were coated with powder to prevent the joining.
Subsequently, nuts were fastened to the two bolts, and a metal plate overlapped between the square steel members was sandwiched and tightened strongly (actual pressure of about 14 kg / cm 2).
And after peeling off an adhesive tape, the silver paste of the said composition was apply | coated to the joint edge periphery of the piled metal plate with a brush, and the brush was reciprocated about 2 to 3 times and covered.
In this state, the silver paste was dried. The dry film thickness was 0.1 to 0.3 mm.
It was put together with the wire in an electric furnace and heated at 730 to 760 ° C. for 8 hours. The electric furnace was turned off, allowed to cool at room temperature, and the upper and lower square steel materials were taken as metal plates for pattern formation. FIG. 2 shows a state in which the metal plate for pattern formation is taken out from the heating furnace. Both dry film thickness of the heating silver paste covered the sintering imitating like forming metal plate.
Reference numeral 2 is a copper plate in FIG. 2, 3 silver plate, mark 6, 7 dove flour together heated silver paste 8, the square steel, 10 bolt insertion holes 9, 11 A bolt 12 is a tightening nut.

<Manufacture of patterned metal plate>
The metal sheet for pattern formation obtained in Examples 1 and 2 was heated with a burner and softened, and then it was stretched with a hammer while it was hot, and the thickness was about 3 mm (the area became about 4 to 5 times). To be). Both the heated paste over the patterned forming metal plate material (silver powder-containing composition), although sintered, is itself separated by working malleable at this hammer.
On the surface of this pattern-forming metal plate material, an electric drill is used to form dozens of circular concave portions where the lower metal surface is exposed by several steps, and the lower metal surface is exposed by several steps using a metal file. An infinite number of linear (band-like) concave portions were formed. This was struck flat with a hammer, and in some cases the surface was shaved to create a pattern.
Furthermore, confirm the mark with the thread saw, apply a roller in the direction that makes it easy to stretch (in the above-mentioned “direction of rolling into a plate as a preparation for use”), and the thickness is about 1 mm (the area is about 60 × 110 mm) In this state, the oxidized portion of copper is colored black and the contrast with silver is vivid, and this completes the patterned metal plate, but if necessary, the color raising process is performed.
As a process of color raising (boiled and colored), it is composed of 6g of patina, 6g of copper sulfate and 2L of water after polishing the patterned metal plate with grindstone, park charcoal, park charcoal powder, etc. and degreasing as usual. The color of the patterned metal plate was confirmed while being immersed in the stewed liquid and heated. Since copper turns red (dark red), a patterned metal plate with a beautiful visual pattern is obtained.

[Comparative Example 1]
A pattern-forming metal plate was prepared in exactly the same manner except that a mixture of powder with charcoal was used instead of the silver paste in Example 1. However, since the powder with charcoal was difficult to apply thinly, it was applied thickly to about 1 to 2 mm.
As a result, in the state taken out from the heating furnace, it separated at two places, and it became clear that the diffusion bonding was not sufficient. Furthermore, since it was easily predicted that it would fall apart by performing a process of striking with a hammer, the subsequent processes were stopped.

[Comparative Example 2]
A pattern-forming metal plate was prepared in exactly the same manner except that a mixture of powder with charcoal was used instead of the silver paste in Example 2. However, since the powder with charcoal was difficult to apply thinly, it was applied thickly to about 1 to 2 mm.
As a result, in the state taken out from the heating furnace, it separated at one place, and it became clear that the diffusion bonding was not sufficient. Furthermore, since it was easily predicted that it would fall apart by performing a process of striking with a hammer, the subsequent processes were stopped.

<In the case of obtaining a metal thermoformed body from a heat-treated body obtained by shaping a copper plastic composition containing copper powder>
<Raw materials used>
The copper powder constituting the copper clay (copper plastic composition) was prepared as a copper mixed powder in which 50% by weight of copper powder having an average particle size of 5 μm and 50% by weight of copper powder having an average particle size of 40 μm were mixed. Mix 90% by weight of this copper mixed powder with 1.04% by weight of methylcellulose as organic binder, 0.78% by weight of starch and 8.18% by weight of water. And made a clay that can be shaped into the desired design.

<Example 3>
Copper clay was stretched to a thickness of 2 mm with a roller, cut into a 20 × 20 mm plate, and dried. Next, silver paste (silver powder-containing composition) is placed with a spatula (clay spatula) so as to cover the entire dried copper clay plate (heated object), and applied to a thickness of about 0.5 mm. To do.
When the applied silver paste is completely dried, a copper clay plate is placed on the ceramic fiber board, held in an electric furnace heated to 780 ° C. for 4 hours, and then heat molded. By this thermoforming, the copper clay plate is sintered to become a copper sintered body (metal thermoformed body), the silver paste is also sintered, and the silver coating is formed on the surface of the copper sintered body. The body is obtained.

  When the heat forming is completed, the silver-coated copper sintered body is taken out from the electric furnace, and the silver coating on the side is scraped with a stick file or the like until the copper sintered body is seen. Then, a sharp tip such as a cutter blade is inserted from the gap between the silver coating and the copper sintered body to widen the gap, and the silver coating is turned up with a nipper or the like to separate from the copper sintered body. It is recognized that a very thin oxide film is formed on the surface of the copper sintered body separated at this point in visual judgment.

Next, the copper sintered body on which a thin oxide film is formed is immersed in a 5% by weight dilute sulfuric acid aqueous solution for about 10 minutes, washed with water, polished with a stainless brush, then polished with a sponge abrasive, Finally, when polished with a silver cloth with a small amount of metal abrasive, a reddish brown luster peculiar to copper metal is obtained.
After the heat forming, the oxide film formed on the surface of the copper sintered body (metal thermoformed body) was so thin that the size of the copper sintered body was not reduced.

<Comparative Example 3>
In contrast to the case of Example 3, a common process is performed to obtain a copper sintered body according to Comparative Example 3 except that the silver paste is not applied. In this case, the surface of the copper clay plate is always affected by oxidation during the heating process.
In the copper sintered body according to Comparative Example 3, a thick oxide film is formed so that the oxide film of about 0.1 to 0.3 mm is peeled off from the surface.
Further, when the copper sintered body according to Comparative Example 3 was polished and finished in the same manner as in Example 3, what was finally obtained was considerably reduced compared with that in Example 3.
From the results of Example 3 and Comparative Example 3, by applying (coating) a silver paste (silver powder-containing composition) to copper clay (copper plastic composition), sintering (thermoforming) is performed in the atmosphere. It was proved that the surface oxidation of the copper sintered body (metal thermoformed body) can be effectively prevented.
Thereby, it can be said that a copper sintered body (metal thermoformed body) can be precisely shaped from copper clay (copper plastic composition).

<When obtaining a metal thermoforming body from the to-be-processed body which made the copper powder containing paste composition adhere to the surface of a member to be decorated>
<Raw materials used>
The copper paste (copper powder-containing paste composition) is 90.0 wt% copper powder having an average particle size of 5.0 μm, 1.0 wt% bismuth powder having an average particle size of 1.0 μm as a sintering accelerator, and an organic binder. Squeegee oil OS-4500 (trademark) (manufactured by Kyoyo Chemical Industry Co., Ltd .; dissolved in an organic solvent of an acrylic ester copolymer) is blended at a rate of 9.0 wt%.
As the member to be decorated, a silver plate (20 × 20 × 0.5 mm) not subjected to special processing or the like was used.
In addition, the used silver paste (silver powder containing composition) is the same as that used in Examples 1, 2, and 3.

<Example 4>
Copper paste (copper powder-containing paste composition) is placed and attached with a spatula so that a circle with a diameter of about 10.0 mm is written in the center of the silver plate (decorated member) (in this case, the weight of the attached copper paste is 0.08 g to 0.10 g). Thus, the produced silver plate + copper paste laminate is left to stand in a dryer set at 100 ° C. for 1 hour and dried.
Further, a silver paste (silver powder-containing composition) is applied onto the dried copper paste, and the produced laminate of silver plate + copper paste + silver paste is again allowed to stand in a dryer set at 100 ° C. for 1 hour. Place and dry.

  The laminated body of silver plate + copper paste + silver paste thus dried is placed on a ceramic fiber board, and held at 780 ° C. for 5 minutes in an electric furnace in which the atmosphere is not particularly adjusted, followed by heat molding. By this thermoforming, the copper paste is sintered on the contact surface with the silver plate to become a copper adhesion film (metal thermoformed body), and the silver coating on which the silver paste is sintered on the opposite surface of this copper adhesion film Is covered.

When the heat forming is completed, the laminate is taken out from the electric furnace and gradually cooled, and then the silver coating can be easily peeled off with a polishing spatula or the like. This is due to a slight gap or crack caused by the difference in shrinkage between the copper paste and the silver paste.
And it is recognized that the surface of the copper adhesion film (metal thermoformed body) appearing from under the silver coating has a reddish brown color characteristic of metal copper. The results of Example 4 exhibit the most excellent surface oxidation preventing effect as compared with Comparative Examples 4A and 4B described below.

<Comparative Example 4A>
In contrast to the case of Example 4, the copper adhesion film according to Comparative Example 4A was sintered on the silver plate by performing a common treatment except that the silver paste was not applied.
It can be seen that the surface of the copper adhesion film of Comparative Example 4A is black and covered with a thick oxide film. Further, when the copper adhesion film was polished with this polishing spatula or the like, it was recognized that oxidation progressed to the inside of the copper adhesion film, and the color unique to metallic copper was not retained.
From the results of Example 4 and Comparative Example 4A, a copper paste (copper powder-containing paste composition) was attached to a silver plate (decorated member), and a silver paste (silver powder-containing composition) was further applied thereon ( It was proved that the surface oxidation of the copper-adhered film (metal thermoformed body) can be effectively prevented even by sintering (thermoforming) in the atmosphere.
Thereby, it can be said that a copper paste (copper powder containing paste composition) is made to adhere to a silver plate (decorative member), and a precise pattern can be formed.

<Comparative Example 4B>
Compared to the case of Example 4, the copper paste according to Comparative Example 4B was subjected to a common treatment except that the silver paste was not applied and the heating atmosphere was reduced by the following means. The membrane was sintered on a silver plate.
This reducing atmosphere was realized by putting a laminate of silver plate + copper paste and charcoal in a stainless steel petri dish with a cover.
As a result, the copper adhesion film on the silver plate was in a state in which a thin oxide film remained on the surface and the color of the metallic copper was almost maintained.

However, the following points became clear as problems.
First, in the process in which oxygen and charcoal present in the petri dish react to form a reducing atmosphere, it is recognized that the temperature varies greatly depending on the state of the petri dish and the amount of oxygen and charcoal present in the petri dish. It was.
If the stainless steel petri dish is not completely sealed just by placing a stainless steel lid, oxygen will enter and the reaction with the charcoal will be promoted, the inside of the petri dish will be hotter than the set temperature of the electric furnace, and further removed from the electric furnace After that, the inside of the petri dish is heated and it is difficult to adjust the temperature by heating it more than necessary.As a result, the copper adhesion film partially alloyed with the silver plate, or the adhesion area of the copper adhesion film melts. In some cases, it became a hole.
In addition, when the stainless steel lid is welded tightly to the stainless steel petri dish and completely sealed, the amount of oxygen is specified, but if the amount of charcoal is small, the reaction with oxygen does not take place sufficiently and oxidation of the copper paste proceeds. Therefore, it was necessary to know the appropriate amount of charcoal according to the volume (size) of the petri dish and the size of the work.
Therefore, in Comparative Example 4B, firing in a reducing atmosphere using a petri dish and charcoal is effective, but there are many factors that adjust the size of the petri dish, the appropriate amount of charcoal, the degree of oxygen penetration, and the like. There is a problem that requires trial and error and skill to know.
Moreover, it is necessary to prepare a reduction container such as a petri dish, and there is a problem that the capacity of the metal thermoformed body that can be accommodated therein is limited depending on the size.

Claims (10)

A step of coating a silver powder-containing composition containing silver powder and an organic binder on the exposed surface of the object to be heated containing a metal that is oxidized by heating in the atmosphere;
Thermoforming the coated heat-treated body by heating in the atmosphere;
And a step of removing at least a part of the silver powder-containing composition heated together from the metal thermoformed product obtained after heating in the atmosphere. The object to be heated is in a state where a plurality of metal plates having different color tones are stacked and pressed in the overlapping direction,
The exposed surface refers to a peripheral edge of at least a joint of the plurality of metal plates,
The said thermoforming means that the said joint joins by diffusion bonding, The manufacturing method of the metal thermoforming body of Claim 1 characterized by the above-mentioned.   3. The metal according to claim 2, wherein the plurality of metal plates pressed and overlapped are aligned so that the directions rolled before the metal plates are overlapped are the same direction. 4. A method for producing a thermoformed article.   A concave portion having an arbitrary shape is formed on the surface of the metal thermoformed article produced by the method according to claim 2 or claim 3 at a depth reaching at least a metal having a different color tone. A method for producing a patterned metal plate material, wherein a desired pattern is formed by performing an operation to perform and an operation to roll and flatten the surface on which the concave portion is formed. The object to be heated is a copper plastic composition containing a copper powder or a copper alloy powder,
The exposed surface refers to the surface of the copper plastic composition;
The said thermoforming means that the copper or copper alloy of the said copper plastic composition sinters, The manufacturing method of the metal thermoforming body of Claim 1 characterized by the above-mentioned. The heat-treated body is obtained by adhering a copper powder-containing paste composition containing copper powder or copper alloy powder to a part / all of the surface of the member to be decorated,
The exposed surface refers to the surface of the adhered copper powder-containing paste composition,
The said thermoforming means that the copper powder or copper alloy powder of the said copper powder containing paste composition sinters on the said to-be-decorated member, The metal heat of Claim 1 characterized by the above-mentioned. Manufacturing method of a molded object.   The said silver powder contains 30-70 weight% of powders with an average particle diameter of 2.2-3.0 micrometers, and the remainder is a powder with an average particle diameter of 5-20 micrometers, Claim 1 characterized by the above-mentioned. The method for producing a metal thermoformed article according to any one of Items 2, 3, 5, and 6.   The organic binder contains 0.02 to 3.0 wt% of starch and 0.02 to 3.0 wt% of water-soluble cellulose resin in terms of solid content excluding water. 8. The method for producing a metal thermoformed article according to any one of items 1, 2, 3, 5, 5, 6, and 7.   The method for producing a metal thermoformed article according to claim 8, wherein the water-soluble cellulose resin is one or more selected from methylcellulose, carboxymethylcellulose, hydroxypropylcellulose, and hydroxypropylmethylcellulose. .   A metal thermoformed article produced by the method according to any one of claims 1 to 9.

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