Imitation sword

Abstract

To provide an imitation sword capable of maintaining the fine appearance of the imitation sword for a long term without generating environment pollution due to hexavalent chrome and health damage to a human body.SOLUTION: An imitation sword including a base material 10 imitating a sword blade and a blade pattern formation plating layer 30 can operate the blade pattern formation plating layer itself as corrosion prevention means to omit a chromium plating layer for conventionally protecting a blade pattern part 31 so as not to rust the blade pattern part. The corrosion prevention means uses the blade pattern formation plating layer 30 as an electroless nickel plating layer including nickel and metal having corrosion resistance and uses a film thickness α after polishing the blade pattern part as a thickness equal to or more than a reference film thickness capable of preventing pinholes according to a plating material from occurring.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a simulated sword that imitates the beauty of a Japanese sword, formed by laminating a plating layer on a base material having the shape of the blade of a Japanese sword. More specifically, in the prior art, even without the outermost chromium plating layer that was essential for preventing discoloration, rust, and scratches on the blade, the beauty of the simulated sword can be maintained over a long period, and the present invention relates to a simulated sword that does not cause environmental pollution by hexavalent chromium and health damage to the human body.

Background Art

[0002] Conventionally, simulated swords used for practicing and performing iaido, stage plays, etc. have imitated the beauty of Japanese swords by laminating a copper plating layer, an electrolytic nickel plating layer, and a hexavalent chromium plating layer in that order on a base material made of zinc die-casting. More specifically, by laminating an electrolytic nickel plating layer on top of the copper plating layer, the silver color and unique luster of the electrolytic nickel plating layer imitate the beauty of the ground color of tamahagane that makes up a Japanese sword.

[0003] The surface hardness of the electrolytic nickel plating layer can be made similar to that of a Japanese sword by increasing the amount of brightener added, but the surface hardness of the plating layer decreases. More specifically, since the surface hardness becomes a soft plating layer with a Vickers hardness of about 150 HV to 400 HV, the blade is easily scratched, and discoloration and rust are likely to occur. Therefore, in conventional simulated swords, it has been essential to laminate a chromium plating layer with a surface hardness of about 800 HV that is resistant to scratching to protect the electrolytic nickel plating layer from scratches and the like.

[0004] However, in the prior art, as described in Patent Documents 1, 2, etc., the blade pattern of a simulated sword was formed by scraping off the hard chromium plating layer and then buffing and roughening the soft electrolytic nickel plating layer to make it white. Therefore, for the blade pattern portion where the chromium plating layer has been removed by polishing, since the soft electrolytic nickel plating layer is exposed, there has been a problem that it cannot be protected from scratches and the like.

[0005] Furthermore, in the conventional polishing operation, when starting to polish the electrolytic nickel plating layer beyond the chromium plating layer, the surface hardness suddenly decreases. As a result, it is easy to excessively scrape the electrolytic nickel plating layer, and the film thickness of the electrolytic nickel plating layer in the blade pattern portion tends to become thin. In the first place, it is difficult to form a uniform plating layer on a flat plating object such as a blade body with the electrolytic nickel plating layer. Even if the blade pattern can be polished uniformly, there will be partially thin film thickness areas, and pinholes reaching the base material are likely to occur at those areas.

[0006] Therefore, in the blade pattern portion where the electrolytic nickel plating layer has been scraped and the film thickness has become thin, even if there are no scratches, sweat, sebum, etc. attached to the blade body from the pinholes can seep in and easily rust the underlying copper plating layer. The rust generated on this copper plating layer gradually emerges from the pinholes to the surface of the dummy knife, discoloring the blade pattern portion in a mottled manner and sometimes impairing the aesthetics of the dummy knife.

[0007] Patent Document 3 discloses the technology of a practice dummy knife applied for by the applicant of the present application. According to the technology described in this document, after forming a blade pattern on the electrolytic nickel plating layer by polishing, a finishing plating layer of a chromium plating layer is laminated. By uniformly covering the polished blade body with a hard chromium plating layer, it is possible to prevent scratches caused by practice, and at the same time, to block the pinholes generated in the electrolytic nickel plating layer due to the polishing of the blade pattern, thereby preventing discoloration and rust from occurring in the blade pattern portion.

[0008] Hexavalent chromium forming the chromium plating layer may lead to health hazards to the human body such as carcinogenicity and environmental pollution, and thus may potentially be subject to regulation in all plating products in the future. Currently, in Europe and the United States, the use of hexavalent chromium has already been prohibited and abolished in automotive parts and the like. In Japan as well, the Japan Automobile Manufacturers Association has self-regulated the use of hexavalent chromium for newly produced automobiles.

[0009] However, in the technology described in Patent Document 3, since the lamination of the chromium plating layer was an essential technology, a new problem has arisen that it is impossible to prevent health hazards and environmental pollution caused by chromium. Even if hexavalent chromium is replaced with trivalent chromium, which causes relatively less health hazards and environmental burden, trivalent chromium oxidizes to hexavalent chromium under acidic conditions, so it was impossible to completely prevent adverse effects on the human body and the environment.

[0010] As described above, in any of the technologies described in Patent Documents 1 to 3, since the lamination of chromium plating was essential, there was no technology for a simulated knife that could solve the new problem of environmental pollution and health hazards caused by hexavalent chromium. Therefore, in order to promote the Japanese sword culture, which is proud of the world, the applicant of the present application has conducted intensive research on a simulated knife that can maintain its aesthetic appearance even without a chromium plating layer whose use is being regulated, and has invented the simulated knife of the present application.

Prior Art Documents

Patent Documents

[0011] Patent Document 1: Japanese Patent Application Laid-Open No. 51-62599 Patent Document 2: Japanese Patent Application Laid-Open No. 52-126325 Patent Document 3: Japanese Patent Application Laid-Open No. 2019-002063

Summary of the Invention

Problems to be Solved by the Invention

[0012] The problem to be solved by the present invention is to provide a simulated knife that can maintain the aesthetic appearance of the simulated knife for a long time with only the plating layer that forms the blade pattern, even without the topmost chromium plating layer that was essential for preventing discoloration, rust, and scratches of the blade, and that does not cause environmental pollution by hexavalent chromium and health hazards to the human body.

Means for Solving the Problems

[0013] The first invention of the present invention is a simulated sword imitating a Japanese sword, comprising a base material and a blade pattern forming plating layer covering the base material, wherein the base material has the shape of the blade of a Japanese sword, and the blade pattern forming plating layer includes a blade pattern portion formed by polishing the plating layer and a non-polished portion where the plating layer is not polished, and also functions as a corrosion prevention means for the blade. The corrosion prevention means consists of the plating material forming the blade pattern forming plating layer and the blade pattern forming plating layer having a thickness equal to or greater than a reference film thickness. The plating material is composed of an electroless nickel plating layer containing nickel and a metal having corrosion resistance. The reference film thickness is a desired film thickness at which pinholes are less likely to occur according to the plating material. The non-polished film thickness in the non-polished portion is set to be equal to or greater than the sum of the assumed polishing thickness according to the blade pattern and the reference film thickness so that the film thickness after polishing in the blade pattern portion is equal to or greater than the thickness of the reference film thickness.

[0014] The material of the base material is preferably a zinc die casting made of zinc, copper, aluminum, etc., but may also be a resin material or the like and is not particularly limited. For example, in the case of a simulated sword for iaido practice, using a zinc die casting as the base material is suitable because the weight is similar to that of a Japanese sword. In the case of a simulated sword for stage drama, using a lightweight aluminum or the like as the base material enables even a female actress to easily swing it, and it can be made into a simulated sword that is not easily fatigued even during long hours of stage practice.

[0015] The plating layer laminated on the base material may be only the blade pattern forming plating layer, but it is preferable to provide an undercoat plating layer for smoothing the base material between the blade pattern forming plating layer and the base material because it can improve the adhesion of the electroless nickel plating layer. Also, although it is preferable for the blade pattern forming plating layer to cover the entire blade, it is sufficient if it covers only the upper body portion ahead of the collar of the blade.

[0016] The plating layer for forming blade patterns includes a blade pattern portion and a non-polished portion other than the blade pattern portion. In addition, the plating layer for forming blade patterns itself is located in the uppermost layer and functions as a corrosion prevention means for the blade body. The blade pattern portion is made to be in a white and shiny state by roughening the plating layer through polishing, and the non-polished portion is left with the silver-colored and shiny luster of the electroless nickel plating layer.

[0017] The corrosion prevention means consists of the plating material of the plating layer for forming blade patterns and the thickness of the plating layer for forming blade patterns. More specifically, the plating layer for forming blade patterns itself is provided with corrosion resistance by using an electroless nickel plating layer containing nickel and a metal having corrosion resistance as the plating material, and further, the corrosion resistance is enhanced by making the film thickness after polishing of the electroless nickel plating layer in the blade pattern portion equal to or greater than the reference film thickness at which pinholes are less likely to occur.

[0018] The plating material refers to the type of metal forming the electroless nickel plating layer and the content ratio of each metal. The metal having corrosion resistance may be, for example, phosphorus, boron, tungsten, etc., but does not include hexavalent chromium which has an environmental load. The electroless nickel plating layer may contain two or more kinds of metals having corrosion resistance. Thereby, the plating layer for forming blade patterns can be provided with corrosion resistance that cannot be obtained with an electrolytic nickel plating layer made of substantially pure nickel.

[0019] The reference film thickness at which pinholes are less likely to occur is not limited because it varies depending on the plating material, but it is suitable to use as an index the film thickness recommended for corrosion prevention in industrial applications. For example, in the Japanese Industrial Standard (JIS standard "H8645:1999") regarding an electroless nickel plating layer containing phosphorus, about 5 μm (Grade 2) is recommended for corrosion prevention applications. Note that since the mock knife is only used in an environment where it is less likely to rust compared to industrial applications, the reference film thickness may be thinner than the film thickness recommended for corrosion prevention applications.

[0020] The non-polished film thickness of the non-polished part is the same as the film thickness before polishing of the blade pattern part, and is made to be equal to or greater than the sum of the assumed polishing thickness that varies for each type of blade pattern and the reference film thickness according to the plating material. Since the thickness of the plating layer to be shaved when forming a desired blade pattern is assumed in advance and the thickness of the plating layer for blade pattern formation is determined, it is possible to make the film thickness after polishing equal to or greater than the reference film thickness without excessively laminating the electroless nickel plating layer that takes time to laminate. The film thickness before and after polishing may be confirmed by a non-destructive test such as a fluorescent X-ray test method.

[0021] The assumed polishing thickness of the blade pattern may be a value obtained empirically from the actual polishing thickness of the test-polished blade pattern. For example, in the case of a blade pattern having a substantially linear shape called a straight blade, since polishing is easy, the assumed polishing thickness may be assumed to be about 3 μm to about 5 μm. On the other hand, in the case of a blade pattern having a wavy shape such as a disordered blade, since the blade body is repeatedly polished while changing the direction in which the buff is pressed, a larger assumed polishing thickness than that of the straight blade is assumed.

[0022] In order to laminate an electroless nickel plating layer with excellent film thickness uniformity in view of the assumed polishing thickness of the blade pattern, even in the blade pattern part where the plating layer is polished, pinholes penetrating to the base are less likely to appear on the surface. Even if there are slightly remaining pinholes in the plating layer for blade pattern formation, within the application range of the mock knife, the corrosion resistance of the plating material can protect the base material and the underlying plating layer from corrosion, and the base material etc. will not rust and discolor the blade pattern part in a mottled manner.

[0023] According to the first invention, even without the topmost chromium plating layer that was essential for preventing discoloration, rust, and scratches on the blade body, the aesthetic appearance of the mock knife can be maintained over a long period, and there is an advantageous effect not found in the prior art that it does not cause environmental pollution and health damage to the human body by hexavalent chromium.

[0024] The second invention of the present invention is the mock knife of the first invention, characterized in that the film thickness after polishing is 3 μm or more, and the non-polished film thickness is 7 μm or more and 30 μm or less.

[0025] Since the film thickness after polishing is 3 μm or more, which corresponds to the first grade of the above JIS standard, in the case of disguise applications where sweat and the like hardly adhere, the aesthetic appearance of the blade pattern can be sufficiently maintained. Also, when the electroless nickel plating layer is polished by about 4 μm, the surface roughness of the blade pattern portion can be increased, and it is easy to form a sharp and white shining blade pattern. In the second invention, even when a highly aesthetic blade pattern is formed with a non-polished film thickness of at least 7 μm or more, the imitation knife is prevented from rusting.

[0026] Furthermore, if the film thickness after polishing is 5 μm or more, it conforms to the second grade recommended for industrial anti-corrosion applications in the above JIS standard, so it is also suitable for practice imitation knives to which sweat easily adheres. As a result, there is an advantageous effect that the aesthetic appearance of the imitation knife can be made closer to the aesthetic appearance of a Japanese sword by the contrast between the white shining blade pattern portion and the non-polished portion that shines with a silver-colored luster.

[0027] Furthermore, when the non-polished film thickness is in the range of 20 μm or more and 30 μm or less, the surface hardness of the electroless nickel plating layer can be accurately measured, and the plating quality can also be managed with high precision. In addition, if the non-polished film thickness of the electroless nickel plating layer is 30 μm or less, even in the case of electroless nickel plating that requires time for plating deposition, it is difficult to reduce productivity.

[0028] The third invention of the present invention is an imitation knife according to the first or second invention, characterized in that the plating material is either an alloy plating containing nickel and phosphorus or an alloy plating containing nickel and boron.

[0029] According to the third invention, the plating material is either an alloy plating containing nickel and phosphorus or an alloy plating containing nickel and boron. The electroless nickel plating layer made of these plating materials has the advantageous effects that it is difficult to be scratched due to its high surface hardness, and since the stability of the plating solution is high, the uniformity of the film thickness of the plating layer is also high, and it is easy to polish the blade pattern as expected.

[0030] The fourth invention of the present invention is a simulated knife of the first or second invention, wherein the plating material is an alloy plating containing nickel and phosphorus, and the phosphorus content in the alloy plating is 2% by weight or more and 10% by weight or less.

[0031] According to the fourth invention, the phosphorus content that eutectifies with nickel is 2% by weight or more and 10% by weight or less with respect to the total weight of the alloy plating. The plating solution that eutectifies phosphorus at this weight ratio has high stability of the plating solution and can form an electroless nickel plating layer with high film thickness uniformity. Furthermore, when sweat, sebum, rain, etc. adhere to the blade pattern portion, even if the blade is only wiped with a cloth, the high corrosion resistance of the nickel-phosphorus alloy prevents the blade from rusting and makes it easy to maintain.

[0032] More preferably, when the phosphorus content of the electroless nickel plating layer is 6% by weight to 8% by weight, it is excellent in all of surface hardness, gloss, and corrosion resistance. As a result, it has the advantageous effect that it can be made into a simulated knife with excellent durability that is easy to use not only for iaido practice but also for stage plays and the like.

[0033] The fifth invention of the present invention is a simulated knife of the fourth invention, characterized in that the blade pattern forming plating layer does not have a discolored and hardened film generated by heat treatment or heat drying treatment of the electroless nickel plating layer.

[0034] At the stage of plating the electroless nickel plating layer, since the plating solution adheres to the blade, it is necessary to wash the plating solution and dry the blade before polishing the blade pattern. The electroless nickel plating layer containing nickel and phosphorus has the property of forming a discolored and hardened film on the surface with the implementation of heat treatment and heat drying treatment, causing the blade to change color to a slightly yellowish brown and the reflected light to become slightly dull.

[0035] Therefore, in the fifth invention, after washing the plating solution, thorough wiping of moisture and natural drying are carried out so as not to cause a discolored and hardened film on the electroless nickel plating layer, thereby drying the blade without heat treatment. As a result, the entire blade is not discolored, and an effect is achieved that a mock sword imitating the beauty of a Japanese sword itself can be obtained.

[0036] The sixth invention of the present invention is a mock sword of the fourth invention, wherein the blade pattern forming plating layer further includes a reflected light relaxation means, and the reflected light relaxation means is composed of a discolored and hardened film formed by heat treatment or heat drying treatment of the electroless nickel plating layer.

[0037] Mock swords are used not only for iaido practice but also for stage plays, costumes, period drama filming, etc. In stage plays, etc., in order to avoid the illumination light reflecting to the audience, measures such as attaching an anti-reflection tape or applying an anti-reflection paint to the blade of a mock sword are taken, but all of them deteriorate the appearance of the mock sword.

[0038] Therefore, in the sixth invention, a discolored and hardened film serving as a reflected light relaxation means is deliberately provided on the electroless nickel plating layer. As a result, the reflected light of the mock sword becomes slightly dull, and an unprecedented advantageous effect is achieved that a mock sword suitable for stage plays, etc. can be obtained while maintaining the smooth beauty of a Japanese sword.

[0039] The seventh invention of the present invention is a mock sword of the first or second invention, further comprising an undercoat plating layer between the base material and the blade pattern forming plating layer, wherein the undercoat plating layer includes a means for enhancing the luster of the blade pattern forming plating layer, and the means for enhancing the luster is characterized in that a mirror-finished surface obtained by buff-polishing the undercoat plating layer is provided at least on the upper body portion of the blade.

[0040] According to the seventh invention, not only is there an underplating layer provided between the base material and the blade pattern forming plating layer to improve the adhesion of the blade pattern forming plating layer, but also a mirror finish surface that serves as a means for enhancing the luster of the blade pattern forming plating layer is provided on the surface of the underplating layer. The mirror finish surface may be provided not only on the upper body portion of the blade that is ahead of the collar but also on the stem portion behind the collar. The material of the metal forming the underplating layer is not limited except for hexavalent chromium, but copper, which has good adhesion with electroless nickel plating, is suitable.

[0041] The polished thickness of the underplating layer is not limited either, but if it is polished until the film thickness of the underplating layer after polishing becomes 50% or more and 80% or less of the film thickness before polishing, the luster of the mirror finish surface is high, and since the polishing process does not become excessively long, it is suitable. Thereby, the luster of the blade pattern forming plating layer laminated on the outermost layer can be approximated to the luster of the tamahagane of a Japanese sword, and a blade with a smooth surface and good appearance can be obtained.

Advantages of the Invention

[0042] · According to the first invention of the present invention, even without the outermost chromium plating layer that was essential for preventing discoloration, rust, and scratches on the blade, the aesthetic appearance of the imitation sword can be maintained over a long period, and there is an advantageous effect not found in the prior art of not causing environmental pollution and health hazards to the human body by hexavalent chromium. · According to the second invention of the present invention, there is an advantageous effect that the aesthetic appearance of the imitation sword can be made even more similar to the aesthetic appearance of a Japanese sword by the contrast between the white and shiny blade pattern portion and the non-polished portion that shines with a silver-like luster. · According to the third invention of the present invention, since the surface hardness is high, it is difficult to get scratched, and since the stability of the plating solution is high, the uniformity of the film thickness of the plating layer is also high, and there is an advantageous effect that it is easy to polish the blade pattern as expected.

[0043] · According to the fourth invention of the present invention, there is an advantageous effect that it can be made into an imitation sword with excellent durability that is easy to use not only for practicing iaido but also for stage plays and the like. · According to the fifth invention of the present invention, the entire blade does not change color, and an effect is achieved in that a simulated sword that imitates the beauty of a Japanese sword itself can be obtained. · According to the sixth invention of the present invention, there is an unprecedented advantageous effect in that the reflected light of the simulated sword becomes slightly dull, and a simulated sword suitable for stage plays and the like can be obtained while maintaining the graceful beauty of the Japanese sword. · According to the seventh invention of the present invention, the luster of the blade pattern forming plating layer on the outermost layer can be approximated to the luster of the tamahagane of a Japanese sword, and a blade with a smooth and good-looking surface can be obtained.

Brief Description of the Drawings

[0044]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0045] In a simulated sword including a base material imitating a blade and a blade pattern forming plating layer, the blade pattern forming plating layer itself is also made to function as a corrosion prevention means for protecting the blade from rusting. The corrosion prevention means consists of making the blade pattern forming plating layer an electroless nickel plating layer containing nickel and a metal having corrosion resistance, and making the film thickness after polishing of the blade pattern portion a thickness equal to or greater than a reference film thickness at which pinholes are less likely to occur according to the plating material.

Examples

[0046] In Example 1, a simulated sword 1 in the case of forming a blade pattern of a straight blade with a small assumed polishing thickness will be described with reference to FIGS. 1 to 3. FIG. 1(A) shows an overall explanatory view of the simulated sword, and FIG. 1(B) shows a partially enlarged view of the tip side of the blade.

[0047] Figure 2(A) is an explanatory diagram of the film thickness of the blade pattern forming plating layer, showing a partially enlarged cross-sectional view of a part of the blade pattern portion surrounded by the broken line portion A in Figure 1(B). Figure 2(B) is an explanatory diagram of the base plating layer, showing a partially enlarged cross-sectional view at the D-E position in Figure 1(A). Figure 3 shows a manufacturing process diagram of the simulated knife.

[0048] In this embodiment, among the blade body 100, the portion housed in the sheath is referred to as the upper body portion 101, and the portion housed in the handle member 102 is referred to as the stem portion 103 for explanation. The simulated knife 1 has a base material 10 forming the blade body, with a base plating layer 20 and a blade pattern forming plating layer 30 laminated thereon. Among the blade pattern forming plating layer, the blade tip side of the upper body portion 101 is roughened by buff polishing to form a straight blade pattern portion 31 (see Figure 1).

[0049] The portion of the blade pattern forming plating layer 30 excluding the blade pattern portion is an unpolished portion 32 that has not been buff polished. The unpolished film thickness of this unpolished portion 32 (see β in Figure 2(A)) is the same as the film thickness of the plating layer before polishing in the blade pattern portion 31. Also, the blade pattern forming plating layer 30 itself forms a corrosion prevention plating layer that functions as a corrosion prevention means. The corrosion prevention means consists of the corrosion resistance of the plating material and the fact that the film thickness after polishing (see α in the same figure) is set to be equal to or greater than a reference film thickness where pinholes are less likely to occur, thereby enhancing the corrosion protection performance.

[0050] The plating material of the blade pattern forming plating layer 30 consists of an electroless nickel plating layer that is an alloy plating of nickel and a metal having corrosion resistance. The metal having corrosion resistance may be phosphorus, boron, tungsten, etc., but is not limited thereto. Also, it may contain multiple types of metals having corrosion resistance, such as nickel-tungsten-phosphorus alloy plating.

[0051] In Example 1, an electroless nickel plating layer composed of an alloy of nickel and phosphorus is specifically described. In Example 3, an example of an electroless nickel plating layer containing nickel and boron is described, and in Example 4, an example of an electroless nickel plating layer containing nickel, tungsten, and phosphorus is described.

[0052] In the mock sword 1, the phosphorus content of the electroless nickel plating layer is set to 6% by weight or more and 8% by weight or less so that it is easy to approximate the ground color of a Japanese sword and can protect the blade from scratches and corrosion. Note that the phosphorus content is not limited to the above ratio, and if it is 2% by weight or more and 10% by weight or less, the balance of surface hardness, gloss, color, and corrosion resistance is good, and it is easy to use for any of practice purposes, theatrical purposes, and cosplay purposes.

[0053] The polished film thickness of the blade pattern portion 31 (refer to α in Fig. 2(A)) is made thicker than the reference film thickness at which pinholes are less likely to occur in electroless nickel plating. Electroless nickel plating mainly composed of nickel and phosphorus is recommended to have a film thickness of at least 5 μm for food protection use (Grade 2 or higher) in Japanese Industrial Standards (JIS standard "H8645:1999"). Since the mock sword is only used in an environment where it is less likely to be corroded compared to industrial use, Grade 1, which is one level lower than the above-mentioned Grade 2, is used as an index for the reference film thickness in the application range of the mock sword.

[0054] The non-polished film thickness of the non-polished portion 32 (refer to β in Fig. 2(A)) is made thicker than the total value of the assumed polishing thickness of the blade pattern (refer to γ in the same figure) and the value of the reference film thickness. Therefore, in the blade pattern portion 31, when the electroless nickel plating layer with the assumed polishing thickness is polished and removed, the polished film thickness (refer to α in the same figure) can be maintained thicker than the reference film thickness at which pinholes are less likely to occur.

[0055] Specific values of each film thickness are such that the reference film thickness is about 3 μm and the assumed polishing thickness of the straight blade pattern is about 4 μm. The non-polished film thickness may be about 7 μm or more, which is the sum of the value of the reference film thickness and the value of the assumed polishing thickness. When increasing the corrosion resistance, the non-polished film thickness may be made about 10 μm or more so that the polished film thickness can be maintained thicker than 5 μm. These actual values of the film thickness are for illustration and are not limited thereto.

[0056] Thus, since the electroless nickel plating layer is plated according to the total value of the reference film thickness and the assumed polishing thickness, even if the electroless nickel plating layer is not laminated excessively, the polished film thickness of the blade pattern portion 31 can be maintained at a thickness where pinholes are less likely to occur. Therefore, even in the case of electroless nickel plating, which takes several times longer than electrolytic plating, it is difficult to reduce productivity. The specific bath composition of the plating solution and the like will be described later together with the process.

[0057] On the other hand, when it is desired to manage and guarantee the plating quality with high precision, it is advisable to thicken the electroless nickel plating layer so that the non-polished film thickness is in the range of 20 μm or more and 30 μm or less. When the non-polished film thickness is 20 μm or more, it becomes easier to accurately measure the surface hardness of only the blade pattern forming plating layer without being affected by the hardness of the underlying plating layer or the like using a surface hardness meter.

[0058] Since the surface hardness of the electroless nickel plating layer varies greatly depending on the content rate of metals other than nickel, the content rate of phosphorus or the like can be estimated from the measured surface hardness. Therefore, by measuring the surface hardness, the corrosion resistance of the blade pattern forming plating layer as a corrosion prevention means can be confirmed without relying on immersion in salt water or the like, and the plating quality of individual products can be managed and guaranteed with high precision.

[0059] The abrasive grain size for polishing the blade pattern may be an abrasive selected from F230 to F360, but in particular, the F240 abrasive is suitable because it easily roughens the blade pattern portion to a white and rough surface. The polishing of the base material may be polishing with a sand belt or buff polishing. While rotating the polishing surface of the sand belt or the like at high speed, it may be pressed against the cutting edge side of the blade body and moved in the longitudinal direction to form a blade pattern.

[0060] In the case of the practice dummy sword, after buff-polishing the blade pattern, it is advisable to form a blade pattern plating layer without a discolored or hardened film on the surface without performing heat treatment or heat drying treatment. In this case, not only is it easy to approximate the appearance of the dummy sword to that of a Japanese sword, but the toughness inherent to the metal remains high. Even if the practice of instantly drawing and sheathing the sword is repeated, damage such as cracks is less likely to occur in the blade pattern plating layer.

[0061] On the other hand, in the case of the dummy sword for drama or cosplay, it is advisable to heat-dry the sword body with a dryer and provide a discolored or hardened film that serves as a means for relaxing reflected light on the blade pattern plating layer. In this case, the reflected light of the blade pattern plating layer can be dulled, making it less likely for the audience to feel dazzled even when the illumination light reflects during a stage play, and also making it easier for the dummy sword to be clearly reflected during commemorative photography outdoors.

[0062] Since the material of the base material 10 is such that the blade pattern plating layer 30 is composed of an electroless nickel plating layer, it is not limited to a conductive material, and a material suitable for the application can be selected. For example, in the case of the practice dummy sword, it is advisable to make the base material of zinc die-cast with a weight approximately the same as that of a Japanese sword. On the other hand, in the case of the dummy sword for drama or cosplay, it is advisable to make the base material of lightweight aluminum, resin, or the like.

[0063] In Example 1, a case will be specifically described where the base material 10 is zinc die-cast, an undercoat plating layer 20 is laminated between the base material 10 and the blade pattern plating layer 30, and the surface of the undercoat plating layer is polished to form a mirror-finished surface 21 (see FIGS. 2(A)). Note that the lamination of the undercoat plating layer may be omitted, or only the polishing of the undercoat plating layer may be omitted.

[0064] By providing the mirror-finished surface 21 on the undercoat plating layer, the undercoat plating layer 20 also functions as a means for enhancing the gloss of the blade pattern plating layer 30. The thickness to be polished and removed from the undercoat plating layer is not limited, but it is preferable to polish it so that the film thickness of the undercoat plating layer after polishing is in the range of 50% or more and 80% or less of the film thickness before polishing while gradually making the abrasive grain size finer, because the smoothness of the undercoat plating layer is increased.

[0065] Note that the polished portion of the underplating layer only needs to be the upper body portion 101 of the blade body that is visible when the blade is drawn, and polishing of the stem portion 103 may be omitted (see FIGS. 1 and 2). In this case, if the film thickness of the underplating layer 20 of the stem portion 103 (see δ in FIG. 2(B)) and the film thickness of the underplating layer 20 of the upper body portion 101 (see δ2 in FIG. 2(A)) are inspected by a fluorescent X-ray test method or the like, it is also possible to confirm the thickness after polishing and removing the underplating layer even in the final product.

[0066] If the material of the underplating layer 20 is an electrolytic copper plating layer, the plating deposition rate on the zinc die-cast base material is fast, and the adhesion to the electroless nickel plating layer is also high, which is suitable. The material of the underplating layer only needs not to be a metal that causes environmental pollution and health damage such as hexavalent chromium, and is not limited to copper. Note that when the underplating layer does not contain trivalent chromium either, it is more suitable because it becomes a completely chromium-free product.

[0067] The underplating layer may be a single layer or a multi-layer. Here, the multi-layer is not limited to the case where plating layers of different metals are laminated, and also includes the case where plating layers of the same metal are laminated such as copper cyanide plating and copper sulfate plating. Note that the underplating layer may be an electroless plating layer.

[0068] Here, the manufacturing process of the dummy knife 1 will be described with reference to the flowchart shown in FIG. 3. (First step: Substrate pretreatment step) In the first step, the substrate forming the blade body is polished and smoothed (S100). Specifically, while rotating a sand belt, a sisal buff, etc. coated with an abrasive, it is pressed against the zinc die-cast substrate and polished so that the surface becomes smooth. Also, the abrasive grain size is gradually changed from a coarser abrasive grain size to a finer abrasive grain size in the order of F40, F100, F180, and F240. When the polishing of the substrate is completed, through the steps of alkaline degreasing, water washing, weak acid immersion for activating zinc, and water washing, oil, oxide films, etc. are removed and the substrate pretreatment is completed. The alkaline degreasing step may be either electrolytic degreasing or immersion degreasing.

[0069] (Step 2: Undercoat Plating Process) In the second step, an electrolytic copper plating layer forming an undercoat plating layer is laminated on the surface of the polished substrate (S200). Here, by changing the bath composition and plating conditions of the plating solution, the electrolytic copper plating layer is laminated in three steps: a copper cyanide strike plating layer, a copper cyanide plating layer, and a copper sulfate plating layer. Examples of the bath composition and plating conditions for each plating layer are shown below.

[0070] (Copper Cyanide Strike Plating Process) As the first layer of the undercoat plating layer, a thin-film copper cyanide strike plating layer is formed by a copper cyanide strike plating bath so as to obtain an initial deposition plating layer with good adhesion. The bath composition per liter of the plating solution is about 30 g / L of cuprous cyanide and about 10 g / L to 15 g / L of free sodium cyanide. The plating bath conditions are a bath temperature of about 40°C, a current density of about 7 A / dm 2 , a plating bath time of about 1 minute to 5 minutes, and a copper cyanide strike plating layer with a film thickness of about 0.5 μm to 1.0 μm is laminated. Before moving on to the copper cyanide plating process, the substrate is washed with water.

[0071] (Copper Cyanide Plating Process) As the second layer of the undercoat plating layer, a copper cyanide plating layer with excellent uniform electrodeposition properties and low erosion to the zinc die-cast substrate is laminated by a copper cyanide bath. The bath composition per liter of the plating solution is about 50 g / L to 60 g / L of cuprous cyanide, about 60 g / L to 80 g / L of sodium cyanide, about 8 g / L to 15 g / L of free sodium cyanide, about 5 g / L to 15 g / L of potassium rhodanide, about 30 g / L to 50 g / L of Rochelle salt, and about 10 g / L to 20 g / L of potassium hydroxide. The plating bath conditions are a bath temperature of about 60°C, a current density of about 5 A / dm 2 , a plating bath time of about 6 minutes to 10 minutes, and a copper cyanide plating layer with a film thickness of about 10 μm to 15 μm is laminated. Before moving on to the copper sulfate plating process, the blade body is washed with water.

[0072] (Copper Sulfate Plating Process) As the third layer of the undercoat plating layer, a copper sulfate plating layer that is superior to the copper cyanide plating layer in leveling property and gloss for smoothing the base material is laminated by a copper sulfate bath. The bath composition per liter of the plating solution is copper sulfate: about 160 g / L to 220 g / L, sulfuric acid stock solution: about 40 g / L to 80 g / L, and chloride ions: about 20 mg / L to 80 mg / L. The plating bath conditions are a bath temperature of about 30 °C, a current density of about 8 A / dm 2 , a plating bath time of about 12 minutes to about 18 minutes, and a copper sulfate plating layer with a film thickness of about 20 μm to 30 μm is laminated. Before moving to the first drying step, the blade is washed with water. The sulfuric acid stock solution mentioned here refers to a sulfuric acid solution containing about 98% of sulfuric acid component by weight ratio.

[0073] (Step 3: First drying step) In the third step, the blade plated up to the undercoat plating layer is dried (S300). In this first drying step, in order not to cause stains or discoloration on the copper sulfate plating layer, after wiping off the moisture with thick blotting paper, the blade is dried by natural drying.

[0074] (Step 4: Polishing step of the undercoat plating layer) In the fourth step, the surface of the undercoat plating layer is polished to form a mirror-finished surface (S400). In this polishing step of the undercoat plating layer, a sisal buff or the like coated with a polishing agent is moved while being pressed against the undercoat plating layer, and at least on the upper body part of the blade, a mirror-finished surface is provided on the surface of the undercoat plating layer. Also here, polishing is performed while replacing the polishing agent from a coarser-grit grade to a finer-grit grade.

[0075] At the stage of finishing the polishing of the underlayer plating layer, an abrasive agent in which a polishing component is kneaded into an oil and fat material and processed into a rod shape is applied to a buff to polish the underlayer plating layer. As the polishing component, a fine particle size corresponding to #6000 of fine powder for precision polishing was used. After polishing, the blade is washed with water. If necessary, it may be washed with water after undergoing alkaline degreasing so as to surely wash the oil and fat component of the abrasive agent. In addition, the fourth step may be omitted when it is desired to relax the reflected light of the blade, such as in the case of a simulated knife for stage drama.

[0076] (Step 5: Electroless nickel plating process) In the fifth step, an electroless nickel plating layer that forms a blade pattern plating layer is plated on the blade plated with the underlayer plating layer (S500). First, in order to improve the adhesion between the underlayer plating layer and the electroless nickel plating layer, the blade is immersed in an activation solution for about 1 minute to activate the electrolytic copper plating layer. The composition of the activation solution is obtained by adding water to a stock solution of sulfuric acid containing 98% by weight of sulfuric acid component and diluting it so that 200 ml of the stock solution of sulfuric acid is contained per liter of the activation solution. After activation, the blade is washed with water.

[0077] Then, the washed blade is immersed in an electroless nickel plating solution to deposit an electroless nickel plating layer. The bath composition per liter of the plating solution is: nickel sulfate: about 20 g / L to 25 g / L, sodium hypophosphite as a reducing agent: about 25 g / L to 30 g / L, sodium hydroxide as a pH adjuster: about 1.6 g / L, lactic acid as a complexing agent: about 27 g / L, propionic acid as an accelerator: about 2 g / L, and sulfur compound as a stabilizer: about 2 mg / L.

[0078] The plating bath conditions are as follows: the bath temperature is adjusted to about 90°C, the pH is adjusted to about 4.0 to 5.0, and air is fed into the plating solution for stirring. Here, the plating bath time was set to about 40 to 45 minutes so that the non-polished film thickness of the electroless nickel plating layer would be about 10 μm. Before proceeding to the blade pattern forming step, the plating solution was washed with water, the moisture was wiped off with thick blotting paper, and then it was naturally dried. The plating bath time may be extended according to the non-polished film thickness. For example, if the film thickness is about 15 μm, the plating bath time may be set to about 60 to 70 minutes.

[0079] (Step 6: Blade Pattern Forming Step) In the sixth step, a profile conforming to the shape of the straight blade pattern is applied to the blade body for masking so that the portion other than the blade pattern part is not polished. While rotating a buff material coated with an abrasive at high speed, it is pressed against the blade body to form a blade pattern (S600). Here, the abrasive used was F240 with a coarse particle size so that the blade pattern part would shine brightly white. Before proceeding to the second drying step, the abrasive is degreased with alkali and washed with water.

[0080] (Step 7: Second Drying Step) In the seventh step, in order not to cause a discoloration and hardening film on the electroless nickel plating layer forming the blade body, after wiping off the moisture adhering to the washed blade body with thick blotting paper, it is naturally dried (S700). If it is desired to relax the reflected light of the blade pattern plating layer, instead of natural drying, a heat drying treatment may be carried out to form a discoloration and hardening film serving as a reflected light relaxation means. The heating temperature and time are not limited, but for example, the blade body may be heated for 1 hour while maintaining the internal temperature of the heating device at about 200°C.

Example

[0081] In Example 2, a simulated knife 2 with a blade pattern of a serrated edge will be described with reference to FIG. 4. FIG. 4(A) shows a partially enlarged view of the blade body for explaining the blade pattern, and FIG. 4(B) shows a partially enlarged cross-sectional view of the portion surrounded by the broken line A in FIG. 4(A). In the following of Example 2, the same components as those in Example 1 are denoted by the same reference numerals and the description thereof is omitted.

[0082] In Example 2, a blade pattern called "Mitsukasagi" is formed. The blade pattern of Mitsukasagi is a distinctive blade pattern known as the blade pattern of a Japanese sword struck at the "Sekigahara" in the province of Mino. It is polished so that the amplitude of the double wave pattern becomes significantly larger every three cycles (see Fig. 4(A)). Here, the wave on the peak side with weak luster will be described as the first blade pattern portion 33, and the wave on the blade tip side with strong luster will be described as the second blade pattern 34.

[0083] For the blade pattern of Mitsukasagi, since it is necessary to change the range where the blade body is masked by two types of profiles and perform buff polishing in two steps, the assumed polishing thickness is larger than that of the straight blade pattern, assuming about 10 μm (see γ2 in Fig. 4(B)). To obtain the same corrosion resistance as the simulated sword 1 with a straight blade pattern, the non-polished film thickness of the plated layer for blade pattern formation (see β2 in the same figure) is set to be thicker than that of the straight blade pattern, at about 15 μm or more, and the film thickness after polishing (see α in the same figure) is set to be about 5 μm or more.

[0084] When polishing the first blade pattern portion 33, the plated layer for blade pattern formation 30 before polishing is masked with a waveform profile having the same shape as the first blade pattern portion and buff polished. In the first blade pattern portion 33, about 4 μm to about 5 μm of the plated layer for blade pattern formation is polished and removed. Also, in the first blade pattern portion 33, in order to make the surface roughness smaller than that of the second blade pattern portion 34 (see Fig. 4(B)), buff polishing is performed using a #360 abrasive in the first blade pattern portion.

[0085] When polishing the second blade pattern portion 34, the plated layer for blade pattern formation is masked with a waveform profile having the same shape as the second blade pattern portion so as to include a part of the first blade pattern portion 33 and buff polished. In the second blade pattern portion 34, about 8 μm to about 10 μm of the plated layer for blade pattern formation is polished and removed in combination with the polishing of the first blade pattern portion 33.

[0086] Also, in the second blade pattern portion 34, buff polishing is performed using an abrasive having a particle size of F240, and the surface roughness is made rougher than that of the first blade pattern portion. As a result, a contrast in the intensity of the shine is generated between the two blade patterns, and the simulated knife 2 having the blade pattern of Mitsukisugi can be obtained.

Example

[0087] In Example 3, an example of the plating bath composition and plating conditions when the electroless nickel plating layer is made of nickel and boron will be briefly described. The bath composition per liter of the plating solution was nickel sulfate: about 15.5 g / L, dimethylamine borane as a reducing agent: about 7.1 g / L, and acetic acid as a pH adjuster: about 18.0 g / L. The weight of acetic acid indicates the weight converted to acetic acid components with a concentration of 100% of the acetic acid aqueous solution.

[0088] The plating conditions were adjusted such that the bath temperature was from about 50°C to about 70°C and the pH was from about 6.3 to about 6.7. The plating bath time is not limited, and it may be adjusted according to the non-polished film thickness of the electroless nickel plating layer. Since there is no Japanese Industrial Standard for electroless nickel plating containing nickel and boron, the recommended film thickness for anti-corrosion use of machine parts etc. may be used as the reference film thickness. In the case of boron, since the corrosion resistance is lower than that of phosphorus, the reference film thickness may be in the range of about 4 μm to 5 μm, which is thicker than the thickness shown in Example 1.

Example

[0089] In Example 4, an example of the plating bath composition and plating conditions when the electroless nickel plating layer is made of nickel, tungsten, and phosphorus will be briefly described. The bath composition per liter of the plating solution was nickel sulfate: about 4.2 g / L, sodium tungstate as a reducing agent: about 3.5 g / L, and sodium hypophosphite: about 3.5 g / L, ammonium sulfate as a pH adjuster: about 30.0 g / L, and sodium citrate as a pH buffer material: about 17.5 g / L.

[0090] The plating conditions were adjusted such that the bath temperature was about 90°C and the pH was adjusted from about 6.3 to 6.7. The plating bath time is not limited and may be adjusted according to the non-polished film thickness of the electroless nickel plating layer. In the case of Example 4, since there is no Japanese Industrial Standard, the film thickness recommended for anti-corrosion use in mechanical parts etc. may be used as the reference film thickness. Note that the electroless nickel plating layer containing nickel, tungsten, and phosphorus has the property that, compared with the case of Example 1, while the corrosion resistance is equivalent, pinholes are less likely to occur even with a thinner film thickness. Therefore, the reference film thickness is preferably in the range of about 2 μm to 3 μm, which is thinner than the thickness shown in Example 1.

[0091] (Others) · In each example, the weight and type of each component shown in the plating bath composition are merely illustrative and, of course, are not limited thereto. Also, regarding the plating conditions, the bath temperature and pH recommended by each manufacturer of the plating solution may be adjusted. Regarding the plating bath time as well, each plating layer may be adjusted so as to have a desired film thickness, and it goes without saying that it is not limited to the plating bath time shown in the examples. · The embodiments disclosed this time should be considered as illustrative in all respects and not restrictive. The technical scope of the present invention is not limited to the above description but is shown by the claims, and it is intended that all modifications within the meaning and scope equivalent to the claims are included.

Explanation of Reference Numerals

[0092] 1, 2... simulation knives, 100... blade body, 101... upper body part, 102... handle member, 103... stem part, 10... base material, 20... undercoat plating layer, 21... mirror finish surface, 30... blade pattern forming plating layer (electroless nickel plating layer), 31... blade pattern part, 32... non-polished part, 33... first blade pattern part, 34... second blade pattern part

Claims

1. In a simulated knife imitating a Japanese sword, a simulated knife including a base material and a blade pattern forming plating layer covering the base material, wherein the base material has the shape of the blade of a Japanese sword, the blade pattern forming plating layer includes a blade pattern portion formed by polishing the plating layer and a non-polished portion where the plating layer is not polished, and also functions as a means for preventing corrosion of the blade, the corrosion prevention means consists of the plating material forming the blade pattern forming plating layer and the blade pattern forming plating layer having a thickness equal to or greater than a reference film thickness, the plating material consists of an electroless nickel plating layer containing nickel and a metal having corrosion resistance, the reference film thickness is a desired film thickness at which pinholes are less likely to occur according to the plating material, so that the film thickness after polishing in the blade pattern portion is equal to or greater than the thickness of the reference film thickness, the non-polished film thickness in the non-polished portion is equal to or greater than the total thickness of the assumed polishing thickness according to the blade pattern and the reference film thickness, a simulated knife characterized by the above.

2. the film thickness after polishing is 3 μm or more, the non-polished film thickness is 7 μm or more and 30 μm or less, a simulated knife according to Claim 1, characterized by the above.

3. the plating material consists of either alloy plating containing nickel and phosphorus or alloy plating containing nickel and boron, a simulated knife according to Claim 1 or Claim 2, characterized by the above.

4. the plating material consists of alloy plating containing nickel and phosphorus, in the alloy plating, the content of phosphorus is 2% by weight or more and 10% by weight or less, a simulated knife according to Claim 1 or Claim 2, characterized by the above.

5. the blade pattern forming plating layer does not have a discolored and hardened film generated by heat treatment or heat drying treatment of the electroless nickel plating layer, a simulated knife according to Claim 4, characterized by the above.

6. the blade pattern forming plating layer further includes a reflected light relaxation means, the reflected light relaxation means consists of a discolored and hardened film formed by heat treatment or heat drying treatment of the electroless nickel plating layer, a simulated knife according to Claim 4, characterized by the above.

7. Furthermore, an undercoat plating layer is provided between the base material and the blade pattern forming plating layer, the undercoat plating layer includes a means for enhancing the luster of the blade pattern forming plating layer, the means for enhancing the luster consists of providing a mirror-finished surface formed by buff-polishing the undercoat plating layer at least on the upper body portion of the blade, The dummy knife according to claim 1 or claim 2, characterized by the above.

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