Sliders and slide fasteners for slide fasteners

Abstract

We provide a lock pin for a slide fastener that is designed to appear black and seamlessly integrated with surrounding components. [Solution] A slider 20 for a slide fastener comprising a slider body 23, a pull tab 25, and a lock pin 21, wherein the lock pin is made of stainless steel, a black oxide film is formed on the surface of the lock pin, and the lightness L* on the surface of the lock pin as defined in the CIELAB color space as defined in JIS Z8781-4 (2013) is 31.70 ≤ L* ≤ 35.90, and the value of a* is -0.708 ≤ a* ≤ 1.929. Furthermore, the difference ΔL* between the lightness L* of the slider body and the lightness L* of the lock pin is ΔL* ≤ 8.54, and the difference in the value of a* Δa* is 0.03 ≤ Δa* ≤ 2.67. In addition, the thickness of the oxide film on the surface of the lock pin is 320 nm or more and 1870 nm or less.

Description

Technical Field

[0001] The present invention relates to a slider for a slide fastener, and particularly to a slider and a slide fastener provided with a black lock pin.

Background Art

[0002] As one type of slider for a slide fastener, there is a slider having a function of stopping the slider from accidentally moving up and down by locking a locking claw to an element according to the operating state of a pull tab. These are sometimes called sliders for slide fasteners with an automatic stop device, or sometimes called auto-lock sliders. Among these sliders for slide fasteners with an automatic stop device, there is a type of slider for a slide fastener with an automatic stop device provided with a component (hereinafter simply referred to as a "lock pin") in which a locking claw for engaging with an element so that the slider does not move and a plate-shaped spring for operating the locking claw between a locked position and an unlocked position are integrated. For example, sliders such as those in Patent Document 1 and Patent Document 2.

[0003] The slider of Patent Document 1 is a slider having a shape structure suitable for manufacturing a slider body by die-casting zinc, and the slider of Patent Document 2 is a slider having a shape structure suitable for manufacturing a slider body by pressing a copper-zinc alloy. Sliders provided with a lock pin in which a locking claw and a plate-shaped spring are integrated, such as those in Patent Document 1 and Patent Document 2, are sometimes called "semi-automatic sliders" or "semi-auto-lock sliders", and in this specification, they are called "semi-automatic sliders" or simply "sliders".

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

[0005] In such semi-automatic sliders, the locking pin requires sufficient strength to maintain the locked state and high durability against repeated elastic deformation, so stainless steel is widely used.

[0006] Furthermore, because such semi-automatic sliders can easily prevent the slide fastener from opening unintentionally, they have been widely used as sliders for slide fasteners on the plackets of clothing such as jeans and jackets. When used in such clothing applications, in the type of slider described in Patent Document 1, the slider body is manufactured by zinc die-casting, and the natural color of the zinc material is used to create a color close to silver, which has been a common practice. Also, as described in Patent Document 2, when copper-zinc alloys such as red brass or brass are used for the slider body and pull tab in clothing such as jeans, the natural color of the copper-zinc alloy is used to create a color close to gold, or the surface is plated with copper-tin to create a silver color, which has been a common practice.

[0007] In the case of clothing applications, stainless steel lock pins have a silver color. Therefore, if the slider body is gold-colored, the stainless steel lock pin is heat-treated in the air to oxidize it and match the gold color before use. If the slider body is silver, the lock pin, which has been heat-treated in the air to oxidize it to a gold color as described above, is then acid-washed to return it to its original silver color, thus preserving the silver color of the lock pin. While semi-automatic sliders have traditionally been used in the manner described above, in recent years there has been a growing need to use semi-automatic sliders in bags and other items. In such cases, the slider color is required to be black, a color commonly used in bags, in addition to the traditional gold and silver.

[0008] When blackening the semi-automatic slider, it's important to note that the term "black" isn't a single, uniform shade; in reality, differences in visible light absorption and reflectivity mean there are many different shades of black. Furthermore, while the lock pin is made of stainless steel, the slider body is not. Since these two parts are manufactured separately and then assembled, the black of each part isn't exactly the same, sometimes resulting in differences in appearance. In particular, in recent years, there's a preference for products with a uniform, so-called "pure black" finish—a black with lower visible light reflectivity and higher absorption. In such cases, if even a small part isn't pure black, its appearance will differ from the overall pure black, potentially creating an undesirable impression. Furthermore, when slide fasteners are used in wetsuits or hunting wear, if the small part has a different color against the overall black material, it can stand out, or conversely, it can stand out by reflecting visible light from certain angles. This could potentially attract sharks or other ferocious and dangerous wild animals, not only making the garment look unsightly but also limiting the uses of the slide fastener.

[0009] Such subtle differences in color tone are not unique to black; they also occur with conventional gold and silver. However, with colors like gold and silver, which are composed of highly directional reflected light, it is natural for the appearance and way they shine to change depending on the angle of light reflection. Therefore, even if there is a slight difference in appearance between the slider body color and the lock pin color, it tends not to be perceived as jarring. However, with colors like black, which exhibit their color by absorbing visible light, differences in color due to the degree of blackness can be more noticeable. [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] When it comes to blackening stainless steel lock pins, plating and painting are options. However, with plating, several undercoat layers must be applied to the stainless steel base material to form a black plating layer that adheres sufficiently to the stainless steel, which complicates the manufacturing process and increases production costs. With painting, the lock pin is subjected to strong friction and elastic deformation, so peeling is a potential drawback that must be considered.

[0011] This invention was conceived from the observation of the sense of unease people feel due to subtle color differences in such black parts. Its purpose is to provide a lock pin for a slide fastener that is designed to appear black and seamlessly integrated with surrounding parts, using a less expensive manufacturing method while maintaining sufficient adhesion strength. [Means for solving the problem]

[0012] The slider for slide fasteners of the present invention has the following features in order to achieve the above objective. A slider (20,30) for a slide fastener comprising a slider body (23,33), a pull tab (25,35), and a lock pin (21,31), wherein the lock pin (21,31) is made of stainless steel, a black oxide film is formed on the surface of the lock pin (21,31), and the lightness L* on the surface of the lock pin (21,31) as defined in the CIELAB color space as defined in JIS Z8781-4 (2013) is 31.70 ≤ L* ≤ 35.90, and the value of a* is -0.708 ≤ a* ≤ 1.929. Furthermore, a notable feature is that the b* value on the surface of the lock pin (21,31), as defined in the CIELAB color space as specified in JIS Z8781-4 (2013), is -2.428 ≤ b* ≤ 0.466. Preferably, the stainless steel material of the lock pins (21, 31) is an austenitic stainless steel material containing 10-14% nickel by weight, and the lightness L* on the surface of the lock pins (21, 31) as defined in the CIELAB color space as defined in JIS Z8781-4 (2013) is 31.70 ≤ L* ≤ 34.16, the value of a* is 0.369 ≤ a* ≤ 1.736, and the value of b* is -2.428 ≤ b* ≤ 0.466. Alternatively, the stainless steel material of the lock pins (21,31) is an austenitic stainless steel material containing 13-17% manganese by weight, and the lightness L* on the surface of the lock pins (21,31) as defined in the CIELAB color space as defined in JIS Z8781-4 (2013) is 33.04 ≤ L* ≤ 35.90, the value of a* is -0.708 ≤ a* ≤ 1.929, and the value of b* is -2.388 ≤ b* ≤ -1.495.

[0013] Preferably, the slider body (23,33) is black, and the difference ΔL* between the lightness L* of the slider body (23,33) and the lightness L* of the lock pin (21,31), as defined in the CIELAB color space defined in JIS Z8781-4 (2013), is ΔL* ≤ 8.54, and the difference Δa* between the a* value of the slider body (23,33) and the a* value of the lock pin (21,31) is 0.03 ≤ Δa* ≤ 2.67. Furthermore, if the stainless steel material of the lock pins (21, 31) is an austenitic stainless steel material containing 10-14% nickel by weight, it is preferable that the slider body (23, 33) is black, and the difference ΔL* between the lightness L* of the slider body (23, 33) and the lightness L* of the lock pins (21, 31), as defined in the CIELAB color space specified in JIS Z8781-4 (2013), is ΔL* ≤ 6.79, and the difference Δa* between the a* value of the slider body (23, 33) and the a* value of the lock pins (21, 31) is 1.11 ≤ Δa* ≤ 2.47. Furthermore, if the stainless steel material of the lock pins (21, 31) is an austenitic stainless steel material containing 13-17% manganese by weight, it is preferable that the slider body (23, 33) is black, and the difference ΔL* between the lightness L* of the slider body (23, 33) and the lightness L* of the lock pins (21, 31), as defined in the CIELAB color space specified in JIS Z8781-4 (2013), is ΔL* ≤ 8.54, and the difference Δa* between the a* value of the slider body (23, 33) and the a* value of the lock pins (21, 31) is 0.03 ≤ Δa* ≤ 2.67.

[0014] Furthermore, it is also preferable to have a slide fastener equipped with the slider for slide fasteners described above, wherein the elements of the slide fastener are manufactured from ferritic stainless steel, and the lightness L* of the elements as defined in the CIELAB color space as defined in JIS Z8781-4 (2013) is 29.67 ≤ L* ≤ 36.24, the value of a* is -0.63 ≤ a* ≤ 0.76, and the value of b* is 0.42 ≤ b* ≤ 1.22. In this case, it is more preferable that the slider body (23,33) is black, the difference ΔL* between the lightness L* of the element as defined in the CIELAB color space as defined in JIS Z8781-4 (2013) and the lightness L* of the slider body (23,33) is ΔL* ≤ 8.94, and the difference Δa* of the a* value is 0.11 ≤ Δa* ≤ 1.49.

[0015] Furthermore, the slider for the slide fastener in the embodiment of the present invention is characterized in that the thickness of the oxide film on the surface of the lock pins (21, 31) is 320 nm or more and 1870 nm or less. In some embodiments, the stainless steel material of the lock pins (21, 31) is an austenitic stainless steel material containing 10% to 14% nickel by weight, and the thickness of the oxide film on the surface of the lock pins (21, 31) is 320 nm to 1260 nm. In some other embodiments, the stainless steel material of the lock pins (21, 31) is an austenitic stainless steel material containing 13% or more and 17% or less of manganese by weight percent, and the thickness of the oxide film on the surface of the lock pins (21, 31) is 440 nm or more and 1870 nm or less. And in the slide fastener using the slider for slide fasteners according to the embodiment of the present invention, it is preferable that the thickness of the oxide film of the element of the slide fastener is 1010 nm or more and 2700 nm or less.

Advantages of the Invention

[0016] According to the configuration of the slider for slide fasteners of the present invention, even when a user desires a black color with a low reflectance of visible light and a high absorption rate as a slide fastener-using product, the black color of the slider for slide fasteners does not cause a sense of incongruity in the whole product being used. In addition, the manufacturing cost is suppressed compared to the case of blackening by plating means. Also, the problem of the adhesion of the colored layer as caused by painting means has been improved.

Brief Description of the Drawings

[0017] [Figure 1] It is a perspective view of the slider for slide fasteners according to the first embodiment of the present invention. [Figure 2] It is a view for explaining the three components constituting the slider for slide fasteners according to the first embodiment of the present invention in a disassembled state. [Figure 3] It is a perspective view of the slider for slide fasteners according to the second embodiment of the present invention. [Figure 4] It is a view for explaining the three components constituting the slider for slide fasteners according to the second embodiment of the present invention in a disassembled state. [Figure 5] It is a schematic view showing the state of the oxide film formed on the surface of the lock pin of the slider for slide fasteners of the present invention. [Figure 6]It is a graph showing the results of analyzing the distribution of metal elements contained in the black oxide film formed on the surface of the lock pins of Examples 1-16 in the depth direction by Auger electron spectroscopy. [Figure 7] Similarly to the above, it is a graph of Example 1-17. [Figure 8] Similarly to the above, it is a graph of Example 1-18. [Figure 9] Similarly to the above, it is a graph of Example 1-19. [Figure 10] Similarly to the above, it is a graph of Example 1-20. [Figure 11] Similarly to the above, it is a graph of Example 1-21. [Figure 12] Similarly to the above, it is a graph of Example 2-16. [Figure 13] Similarly to the above, it is a graph of Example 2-17. [Figure 14] Similarly to the above, it is a graph of Example 2-18. [Figure 15] Similarly to the above, it is a graph of Example 2-19. [Figure 16] Similarly to the above, it is a graph of Example 2-20. [Figure 17] Similarly to the above, it is a graph of Example 2-21. [Figure 18] Similarly to the above, it is a graph of Comparative Example 1-2. [Figure 19] Similarly to the above, it is a graph of Comparative Example 1-3. [Figure 20] Similarly to the above, it is a graph of Comparative Example 2-2. [Figure 21] Similarly to the above, it is a graph of Comparative Example 2-3. [Figure 22] Similarly to the above, it is a graph of Comparative Example 3. [Figure 23] It is a graph showing the results of analyzing the distribution of metal elements contained in the black oxide film formed on the surface of the slide fastener element of Example 3-16 in the depth direction by Auger electron spectroscopy. [Figure 24]The graph above is the same as that of Example 3-17. [Figure 25] The graph above is the same as that of Example 3-18. [Figure 26] The graph above is the same as that of Example 3-19. [Figure 27] The graph above is the same as that of Example 3-20. [Figure 28] The graph shown above is the same as that of Example 3-21. [Modes for carrying out the invention]

[0018] The embodiments of the present invention will be described below with reference to the drawings. Figure 1 is a perspective view of a slider 20 for a slide fastener according to a first embodiment of the present invention. As shown in Figure 2, this slider 20 comprises at least three parts: a locking pin 21, a slider body 23, and a pull tab 25. The slider body 23 of the type of slider 20 in Figure 1 has a shape and structure suitable for manufacturing by die-casting using zinc material. The locking pin 21 is made of stainless steel because it needs to have sufficient strength to maintain the stopped locked state of the slider 20 and sufficient durability against repeated elastic deformation. The pull tab 25 is made of an appropriate material such as zinc or a copper-zinc alloy. These locking pin 21, slider body 23, and pull tab 25 are each manufactured as separate parts in separate processes. Then, the pull tab 25 is attached to the slider body 23 by crimping, and the locking pin 21 is attached to the body 23 to complete the slider 20.

[0019] In this embodiment, during the manufacturing process of each component, the lock pin 21, slider body 23, and pull handle 25, all three are colored to have a black appearance. Preferably, the body 23 is colored black by painting. The metal part of the pull handle 25 can also be colored by painting, and if necessary, the entire pull handle can be made black by integrally molding black rubber material around the metal part. Note that the slider body 23 and pull handle 25 may be colored black by plating or chemical conversion treatment instead of painting. As for the lock pin 21, it is possible to color it black by painting or plating, but in this embodiment, it is colored black by chemical conversion treatment. The process of blackening the lock pin 21 will be described in more detail later.

[0020] Figure 3 is a perspective view of a slider 30 for a slide fastener according to a second embodiment of the present invention. As shown in Figure 4, this slider 30 comprises at least three parts: a locking pin 31, a slider body 33, and a pull tab 35. The slider body 33 of the slider 30 of this type in Figure 3 has a shape and structure suitable for manufacturing by press-forming a copper-zinc alloy. The locking pin 31 is made of stainless steel because it is required to have sufficient strength to maintain the stopped-lock state of the slider 30 and high durability against repeated elastic deformation. The pull tab 35 is made of an appropriate material such as a copper-zinc alloy. These locking pin 31, slider body 33, and pull tab 35 are each manufactured as separate parts in separate processes, and then the pull tab 35 and locking pin 31 are attached to the slider body 33 to form the finished slider 30.

[0021] In the second embodiment of the present invention, during the manufacturing process of each component, the lock pin 31, the slider body 33, and the pull handle 35, all of them are colored to have a black appearance. The body 33 and the pull handle 35 are preferably colored black by plating, but they can also be colored black by painting or chemical conversion treatment. The lock pin 31 can also be colored by plating or painting, but in this embodiment as well, it is colored black by chemical conversion treatment.

[0022] Sliders 20, 30 having a structure comprising at least three components as shown in Figures 1 to 4 above are sometimes called "semi-automatic sliders" or "semi-automatic locking sliders" as mentioned above, but in this specification, they will simply be referred to as "sliders 20, 30" in the description.

[0023] Next, the blackening treatment of the lock pins 21 and 31 in the embodiment of the present invention will be described. When attempting to blacken the stainless steel lock pins 21 and 31 against the black slider bodies 23 and 33, various methods such as painting, plating, and chemical treatment can be considered for blackening the lock pins 21 and 31. However, when using painting to blacken the stainless steel lock pins 21 and 31, the paint tends to peel off easily, leading to problems in terms of long-term quality, as the lock pins are components that undergo repeated elastic deformation and are subjected to strong friction from metal contact with the pull tab and washing. Furthermore, when using plating to blacken the stainless steel lock pins 21 and 31, it is difficult to directly laminate a black plating layer onto the stainless steel base material with good adhesion, requiring several layers of underplating to improve adhesion, which increases manufacturing costs. In addition, whether using painting or plating, obtaining a black color with low visible light reflectivity and high absorption requires thicker paint or plating films, which has the disadvantage of losing the texture of the stainless steel material of the lock pin due to the coating. For these reasons, in the present invention, an oxide film is formed on the lock pins 21 and 31 by chemical conversion treatment to blacken them. Figure 5 is a schematic diagram showing the oxide film formed on the surface of the lock pins 21 and 31 of the slider for the slide fastener of the present invention. An oxide film 53 is formed on the surface of the base material 51 of the lock pins 21 and 31.

[0024] Attempts have been made to blacken the lock pins 21 and 31 by chemical conversion treatment, and it has been possible to blacken them using a relatively simple process. Such chemical conversion treatments are widely used in which, after pretreatment steps such as polishing, heat treatment, and removal of naturally formed oxide films are performed on parts pressed from stainless steel, an oxide film is formed by immersion in an acidic solution (chromic acid-based solution) or an alkaline solution (caustic soda-based solution), and then cleaning and drying are performed as posttreatment.

[0025] However, even with an oxide film produced by chemical conversion treatment, depending on the state of the oxide film, the lock pins 21 and 31 may appear not to be a perfect black (the black color exhibited by an object that completely absorbs visible light) depending on the angle from which they are viewed, due to the way light is reflected. In such cases, depending on the viewing angle, the black color of the product using the zipper (bags, clothing, etc.) and the black color of the slider body 23 and 33 may not appear to be the same black as the black color of the lock pins 21 and 31, resulting in a visual discrepancy. The reason for this is that the oxide film was not thick enough to sufficiently suppress the reflection of visible light to approach a perfect black, and also not to sufficiently absorb visible light to approach a perfect black. Therefore, in the present invention, the oxide film thickness is formed to a thickness that is sufficient to sufficiently suppress the reflection of visible light to approach a perfect black, which was not present in conventional chemical conversion treated lock pins 21 and 31.

[0026] Next, we will explain the results of measurements taken for the brightness and hue of the lock pins 21 and 31 in the embodiment of the present invention.

[0027] As a means of evaluating the degree of blackness of the sliders 20, 30 and lock pins 21, 31 in the embodiments of the present invention, the values ​​of a*, b*, and L* in the CIELAB color space specified in JIS Z8781-4 (2013) were used. Here, a* and b* are color tones specified in the CIELAB color space specified in JIS Z8781-4 (2013), where a* represents a magenta-green color tone (+ is closer to magenta, - is closer to green), and b* represents a yellow-blue color tone (+ is closer to yellow, - is closer to blue). In addition, L* represents the lightness specified in the CIELAB color space specified in JIS Z8781-4 (2013), and a larger value indicates a higher gloss. The color measurement was performed using an RTC-21 manufactured by Ikegami Tsushinki Co., Ltd. The light source was LED lighting.

[0028] Examples 1-1 to 1-15, shown in Table 1, are lock pins 21 and 31 in embodiments of the present invention, manufactured from nickel-based austenitic stainless steel containing 10-14% nickel. More specifically, they are lock pins 21 and 31 in embodiments of the present invention, manufactured from nickel-based austenitic stainless steel containing 12 weight percent nickel, 20 weight percent chromium, and 3 weight percent manganese. The appearance of Examples 1-1 to 1-15 is a deep, rich black, with almost no change in appearance depending on the angle of light reflection. Table 1 shows the results of measuring the lightness L*, a*, and b* values ​​for Examples 1-1 to 1-15 and comparing them with the lightness L*, a*, and b* values ​​of the slider bodies 23 and 33. Note that "Brightness difference ΔL* from the body" is the value obtained by subtracting "Brightness L* of the slider body" from "Measured value of Brightness L* for each example", "Color difference Δa* from the body" is the value obtained by subtracting "Measured value of a* of the slider body" from "Measured value of a* for each example", and "Color difference Δb* from the body" is the value obtained by subtracting "Measured value of b* of the slider body" from "Measured value of b* for each example" (the same applies to Tables 2, 3, and 4 below).

[0029] Examples 2-1 to 2-15, shown in Table 2, are lock pins 21 and 31 in embodiments of the present invention, manufactured from manganese-based austenitic stainless steel containing 13-17% manganese. More specifically, they are lock pins 21 and 31 in embodiments of the present invention, manufactured from manganese-based austenitic stainless steel containing 15 weight percent manganese, 4 weight percent nickel, and 17 weight percent chromium. The appearance of Examples 2-1 to 2-15 is a deep, rich black, with almost no change in appearance depending on the angle of light reflection. Table 2 shows the results of measuring the lightness L*, a*, and b* values ​​for Examples 2-1 to 2-15 and comparing them with the lightness L*, a*, and b* values ​​of the slider bodies 23 and 33.

[0030] Examples 3-1 to 3-15, shown in Table 3, are embodiments in which test pieces (slide fastener element-shaped test pieces) made from ferritic stainless steel (SUS430) were subjected to the same chemical conversion treatment to blacken them as in the above examples. The appearance of Examples 3-1 to 3-15 is a deep, rich black, with almost no change in appearance depending on the angle of light reflection. Table 3 shows the results of measuring the lightness L*, a*, and b* values ​​for Examples 3-1 to 3-15 and comparing them with the lightness L*, a*, and b* values ​​of slider bodies 23 and 33.

[0031] [Table 1]

[0032] [Table 2]

[0033] [Table 3]

[0034] The slider bodies 23 and 33 are sliders that have been blackened by painting. They are painted with a black paint that has low reflectivity and high absorption of visible light. The lightness L* value of the black paint was L* = 27.36, and the values ​​of a* and b* were a* = -0.738 and b* = -0.424, respectively.

[0035] In these examples 1-1 to 2-15, the lock pins 21 and 31, despite the fact that both the slider body 23 and 33 are made from different materials, processed and colored separately before assembly, maintain a low brightness L* difference (ΔL) between the slider body 23 and 33 and the lock pins 21 and 31, with ΔL* ≤ 8.54. The "color difference Δa*" and "color difference Δb*" from the body are also kept within acceptable limits, and in particular, the difference in the value of a* (Δa*) is kept low, with 0.03 ≤ Δa* ≤ 2.67. As a result, the appearance is such that it is difficult to get the impression that there is a significant difference in the appearance of the black color of the two parts. Furthermore, the absolute value of brightness L* is 31.70 ≤ L* ≤ 35.90, and the values ​​of a* and b* are -0.708 ≤ a* ≤ 1.929 and -2.428 ≤ b* ≤ 0.466, respectively. As a result, the black color of lock pins 21 and 31 is a black that has a lower reflectivity and higher absorption of visible light than other black colors, and can be described as true black. Therefore, even when used as a component in the slider of a slide fastener in a product with a concept of being entirely black, the lock pins 21 and 31 will not stand out as being different. In some embodiments, the difference in brightness L* (ΔL) between the slider bodies 23, 33 and the lock pins 21, 31 exceeds 6.3, resulting in a slightly brighter brightness difference. However, in these embodiments, the difference in a* value (Δa*) is kept within a low range of less than 2.7, so there is no unnatural appearance such as a reddish-brown color depending on the angle of light reflection.

[0036] In particular, the nickel-based austenitic stainless steel lock pins 21 and 31 in Examples 1-1 to 1-15 have a brightness difference L* (ΔL) with the slider bodies 23 and 33 kept within a low range of 4.34 ≤ ΔL* ≤ 6.79. The "color difference Δa*" and "color difference Δb*" with the body are also kept within an acceptable low range, and in particular, the difference in the value of a* (Δa*) is kept within a low range of 1.11 ≤ Δa* ≤ 2.47. As a result, the appearance does not give the impression that there is a large difference in the appearance of the black color of the two parts. Furthermore, the absolute value of brightness L* is 31.70 ≤ L* ≤ 34.16, and the values ​​of a* and b* are 0.369 ≤ a* ≤ 1.736 and -2.428 ≤ b* ≤ 0.466, respectively. As a result, the black color of lock pins 21 and 31 is a black that has a lower reflectivity and higher absorption of visible light than other black colors, and can be described as true black. Therefore, even when used as a component in the slider of a slide fastener in a product with a concept of being entirely black, the lock pins 21 and 31 will not stand out as being different.

[0037] Furthermore, in particular, the manganese-based austenitic stainless steel lock pins 21 and 31 in Examples 2-1 to 2-15 have a difference in brightness L* (ΔL) with the slider bodies 23 and 33 kept within a low range of 5.68 ≤ ΔL* ≤ 8.54. The "color difference Δa*" and "color difference Δb*" with the body are also kept within an acceptable low range, and in particular, the difference in the value of a* (Δa*) is kept within a low range of 0.03 ≤ Δa* ≤ 2.67. As a result, the appearance does not give the impression that there is a significant difference in the appearance of the black color of the two parts. Furthermore, the absolute value of brightness L* is 33.04 ≤ L* ≤ 35.90, and the values ​​of a* and b* are -0.708 ≤ a* ≤ 1.929 and -2.388 ≤ b* ≤ -1.495, respectively. As a result, the black color of lock pins 21 and 31 is a black that has a lower reflectivity and higher absorption of visible light than other black colors, and can be described as a true black. Therefore, even when used as a component in the slider of a slide fastener in a product with a concept of being entirely black, the lock pins 21 and 31 will not stand out as being different.

[0038] Furthermore, in the test pieces (slide fastener element-shaped test pieces) manufactured from ferritic stainless steel (SUS430) in Examples 3-1 to 3-15, the difference in brightness L* (ΔL) was kept within a low range of 2.31 ≤ ΔL* ≤ 8.94, similar to the lock pins 21 and 31. The "color difference Δa* from the body" and "color difference Δb* from the body" were also kept within a low range that is within the acceptable range, and in particular, the difference in the value of a* (Δa*) was kept within a low range of 0.11 ≤ Δa* ≤ 1.49. As a result, the appearance is such that it is difficult to get the impression that there is a big difference in the appearance of the black color of the two parts. Furthermore, since the absolute value of brightness L* is 29.67 ≤ L* ≤ 36.24, and the values ​​of a* and b* are -0.63 ≤ a* ≤ 0.76 and 0.42 ≤ b* ≤ 1.22, respectively, by using not only sliders 20 and 30 but also slide fastener elements from Examples 3-1 to 3-15, in products with a concept where the entire product is completely black, the slide fastener elements will not stand out as being of a different impression, and the entire slide fastener will give a unified black impression.

[0039] In contrast, the following shows the results of similar color measurements performed on a comparative example of a lock pin that had been blackened by chemical conversion treatment but whose degree of blackening was insufficient (i.e., a comparative example in which the visible light reflectance was not sufficiently low and the absorptive rate was not sufficiently high, resulting in only a black color).

[0040] [Table 4]

[0041] In Table 4, the lock pin of Comparative Example 1 has a black appearance that is lighter and more reddish compared to those of Examples 1-1 to 2-15, and appears reddish-brown depending on the angle of light reflection. In this comparative example 1, the lock pin has a slightly high difference in brightness L* (ΔL) between it and the slider body 23 and 33, at ΔL* = 6.35, and also a high color difference Δa* from the body at 5.50. Therefore, it gives the impression that there is a significant difference in the appearance of black compared to the slider body. Furthermore, the absolute value of brightness L* is L* = 33.71, and the values ​​of a* and b* are a* = 4.67 and b* = -0.16, respectively. As a result, the black color of the lock pin is not in the range of so-called true black, which has a lower reflectivity and higher absorption of visible light. When used as a component in the slider of a slide fastener in a product where the entire product is designed to be true black, the lock pin will stand out as being distinctly different.

[0042] In Table 4, the lock pin of Comparative Example 2 has an appearance that is closer to brown than black, and appears brown depending on the angle of light reflection. In this comparative example 2, the difference in brightness L* (ΔL) between the lock pin and the slider body 23,33 is extremely high at ΔL* = 16.1, and the color difference Δa* from the body is also high at 19.6. Therefore, it gives the impression that there is a significant difference in the appearance of black between the lock pin and the slider body. Furthermore, the absolute value of brightness L* is L* = 43.48, and the values ​​of a* and b* are a* = 18.89 and b* = 10.58, respectively. As a result, the color of the lock pin is closer to brown than black, and when used as a component in the slider of a slide fastener in a product where the entire product is designed to be completely black, the lock pin will stand out as being distinctly different.

[0043] In contrast, since the sliders 20 and 30 of the present invention have the configuration described above, even if the lock pins 21 and 31, which have been chemically treated to black, are used as components in the sliders of a slide fastener in a product where the entire product is designed to be completely black, the lock pins 21 and 31 will not give the impression of being a conspicuously different color. Furthermore, if a similar black oxide film is also applied to the stainless steel fastener elements, the entire slide fastener can be given a unified black appearance.

[0044] Next, the condition of the thickness of the oxide film formed on the surface of the lock pins 21, 31 or the test piece (a test piece in the shape of a slide fastener element) in the embodiment of the present invention will be described with reference to Figures 6 to 23.

[0045] Figures 6 to 17 are graphs showing the distribution of metal elements contained in the black oxide film 53 formed on the surface of the lock pins 21 and 31 in embodiments of the present invention, as analyzed in the depth direction by Auger electron spectroscopy. Figures 18 to 23 are graphs showing the results of analyzing the distribution of metal elements contained in the black oxide film 53 formed on the surface of a test piece (a test piece in the shape of a slide fastener element) in an embodiment of the present invention, using Auger electron spectroscopy in the depth direction.

[0046] First, let's explain Figures 6 through 11. Figures 6 to 11 show the results of analyzing the lock pins 21 and 31 in embodiments of the present invention, which were manufactured from nickel-based austenitic stainless steel containing 10-14% nickel, similar to Examples 1-1 to 1-15 shown in Table 1 above. For convenience, the sample analyzed in Figure 6 will be referred to as Example 1-16, the sample analyzed in Figure 7 as Example 1-17, the sample analyzed in Figure 8 as Example 1-18, the sample analyzed in Figure 9 as Example 1-19, the sample analyzed in Figure 10 as Example 1-20, and the sample analyzed in Figure 11 as Example 1-21. Here, we will explain in detail the relationship between the implementation samples of Examples 1-1 to 1-15 shown in Table 1 and the implementation samples of Examples 1-16 to 1-21 from which film thickness data was obtained by Auger electron spectroscopy. Examples 1-1 to 1-5 in Table 1 and Examples 1-16 (Figure 6) and 1-17 (Figure 7), from which film thickness data was obtained by Auger electron spectroscopy, are implementation samples from a group that underwent chemical conversion treatment as part of the same manufacturing lot. In other words, when chemical conversion treatment is performed on small parts such as lock pins, several hundred lock pins are treated at once. From this manufacturing lot of several hundred units treated at once, the seven lock pins that were arbitrarily sampled for obtaining measurement data are Examples 1-1, 1-2, 1-3, 1-4, and 1-5 in Table 1, and Examples 1-16 (Figure 6) and 1-17 (Figure 7), from which film thickness data was obtained by Auger electron spectroscopy. Similarly, Examples 1-6, 1-7, 1-8, 1-9, and 1-10 in Table 1, along with Examples 1-18 (Figure 8) and 1-19 (Figure 9), for which film thickness data was obtained by Auger electron spectroscopy, belong to the same group of products that underwent chemical conversion treatment as part of the same manufacturing lot. Similarly, Examples 1-11, 1-12, 1-13, 1-14, and 1-15 in Table 1, along with Examples 1-20 (Figure 10) and 1-21 (Figure 11), for which film thickness data was obtained by Auger electron spectroscopy, belong to the same group of products that underwent chemical conversion treatment as part of the same manufacturing lot.

[0047] Let's explain Figure 6. Figure 6 is a graph showing the change in the proportion of each metal element in the thickness direction of the oxide film layer of the lock pin 21. By looking at the change in the distribution of oxygen (O) along with the constituent elements of iron (Fe), manganese (Mn), chromium (Cr), nickel (Ni), carbon (C), and silicon (Si) contained in the base stainless steel material, the thickness of the oxide film can be estimated. In this specification, the thickness in the depth direction up to the point where the value of the oxygen amount near the surface (maximum value) formed on the sample becomes 50% is defined as the thickness of the oxide film for convenience (hereinafter simply referred to as "thickness of the oxide film" or "film thickness"). For example, in Figure 6, the maximum value of the oxygen amount near the surface formed on the sample is approximately 3500 on the vertical axis (Intensity), and the thickness of the oxide film is defined as 340 nm, which is the depth at which the value becomes 1750, which is 50% of that value. In other words, the thickness of the oxide film in Examples 1-16 is 340 nm.

[0048] Similarly, examining the thickness of the oxide film, the oxide film thickness in Example 1-17 shown in Figure 7 is 320 nm. The oxide film thickness in Example 1-18 shown in Figure 8 is 530 nm. The oxide film thickness in Example 1-19 shown in Figure 9 is 480 nm. The oxide film thickness in Example 1-20 shown in Figure 10 is 1260 nm. The oxide film thickness in Example 1-21 shown in Figure 11 is 1010 nm. The thickness distribution range of the oxide film in these six experimental samples, from Examples 1-16 to 1-21, is between 320 nm and 1260 nm.

[0049] Next, we will explain Figures 12 to 17. Figures 12 to 17 show the results of analyzing the lock pins 21 and 31 in embodiments of the present invention, which were manufactured from manganese-based austenitic stainless steel containing 13-17% manganese, similar to Examples 2-1 to 2-15 shown in Table 2 above. For convenience, the sample analyzed in Figure 12 will be called Example 2-16, the sample analyzed in Figure 13 will be called Example 2-17, the sample analyzed in Figure 14 will be called Example 2-18, the sample analyzed in Figure 15 will be called Example 2-19, the sample analyzed in Figure 16 will be called Example 2-20, and the sample analyzed in Figure 16 will be called Example 2-21. Here, we will explain in detail the relationship between the implementation samples of Examples 2-1 to 2-15 shown in Table 2 and the implementation samples of Examples 2-16 to 2-21 from which film thickness data was obtained by Auger electron spectroscopy. Examples 2-1 to 2-5 in Table 2 and Examples 2-16 (Figure 12) and 2-17 (Figure 13), from which film thickness data was obtained by Auger electron spectroscopy, are implementation samples from a group that underwent chemical conversion treatment as part of the same manufacturing lot. In other words, when chemical conversion treatment is performed on small parts such as lock pins, several hundred lock pins are treated at once. From this manufacturing lot of several hundred units treated at once, the seven lock pins that were arbitrarily sampled for obtaining measurement data are Examples 2-1, 2-2, 2-3, 2-4, and 2-5 in Table 2, and Examples 2-16 (Figure 12) and 2-17 (Figure 13), from which film thickness data was obtained by Auger electron spectroscopy. Similarly, Examples 2-6, 2-7, 2-8, 2-9, and 2-10 in Table 2, along with Examples 2-18 (Figure 14) and 2-19 (Figure 15), for which film thickness data was obtained by Auger electron spectroscopy, belong to the same group of products that underwent chemical conversion treatment as part of the same manufacturing lot. Similarly, Examples 2-11, 2-12, 2-13, 2-14, and 2-15 in Table 2, along with Examples 2-20 (Figure 16) and 2-21 (Figure 17), for which film thickness data was obtained by Auger electron spectroscopy, belong to the same group of products that underwent chemical conversion treatment as part of the same manufacturing lot.

[0050] The definition of the oxide film thickness, as read from the measurement data in Figures 12 to 17, is the same as the method described in Figure 6 above. Specifically, in Figure 12, the maximum value of oxygen near the surface formed on the sample is approximately 3750 on the vertical axis (Intensity), and the thickness of the oxide film is defined as 440 nm, which is 50% of that value, or 1875. In other words, the thickness of the oxide film in Example 2-16 is 440 nm.

[0051] Similarly, examining the thickness of the oxide film, the oxide film thickness in Example 2-17 shown in Figure 13 is 570 nm. The oxide film thickness in Example 2-18 shown in Figure 14 is 840 nm. The oxide film thickness in Example 2-19 shown in Figure 15 is 860 nm. The oxide film thickness in Example 2-20 shown in Figure 16 is 1870 nm. The oxide film thickness in Example 2-21 shown in Figure 17 is 1830 nm. The thickness distribution range of the oxide film in these six experimental samples, from Example 2-16 to Example 2-21, is between 440 nm and 1870 nm.

[0052] On the other hand, a comparative example in which the oxide film thickness was not formed to a thickness sufficient to sufficiently suppress the reflection of visible light to approach complete blackness will be described below with reference to Figures 18 to 21, in the same manner as the above example.

[0053] Figures 18 and 19 show the results of analyzing samples extracted from lock pins that underwent chemical conversion treatment as part of the same manufacturing lot as Comparative Example 1, using Auger electron spectroscopy in the same manner as in the above example. For convenience, the sample analyzed in Figure 18 will be called Comparative Example 1-2, and the sample analyzed in Figure 19 will be called Comparative Example 1-3. When the film thickness of Comparative Example 1-2 and Comparative Example 1-3 were estimated using Auger electron spectroscopy in the same manner as above, it was found that the oxide film thickness of Comparative Example 1-2 was approximately 2020 nm, and the oxide film thickness of Comparative Example 1-3 was approximately 2300 nm. In other words, the film thickness of Comparative Example 1 was too thick compared to the film thickness distribution range of the example of the present invention.

[0054] Figures 20 and 21 show the results of analyzing samples extracted from lock pins that underwent chemical conversion treatment as part of the same manufacturing lot as Comparative Example 2, using Auger electron spectroscopy in the same manner as in the above example. For convenience, the sample analyzed in Figure 20 will be called Comparative Example 2-2, and the sample analyzed in Figure 21 will be called Comparative Example 2-3. When the film thickness of Comparative Example 2-2 and Comparative Example 2-3 were estimated using Auger electron spectroscopy in the same manner as above, it was found that the oxide film thickness of Comparative Example 2-2 was approximately 40 nm, and the oxide film thickness of Comparative Example 2-3 was approximately 60 nm. In other words, the film thickness of Comparative Example 2 was too thin compared to the film thickness distribution range of the example of the present invention. Furthermore, a lock pin made of stainless steel containing 10% to 14% nickel by weight, similar to Comparative Example 2, but manufactured in a different lot and subjected to chemical conversion treatment, was also analyzed by Auger electron spectroscopy. This is designated as Comparative Example 3. Comparative Example 3 has a black appearance that is slightly reddish, and can appear brown depending on the angle of light reflection. It cannot be evaluated as a true black, as it has a low reflectivity and high absorption rate of visible light. Figure 22 shows the results of the analysis of Comparative Example 3 using Auger electron spectroscopy, similar to the method described above. Based on Figure 22, the estimated film thickness was found to be approximately 2020 nm, similar to the method described above. This indicates that the film thickness of Comparative Example 3 was excessively thick compared to the film thickness distribution range of the examples of the present invention.

[0055] From the analysis results of each example and comparative example described above, it was found that, as in Comparative Example 1, when the thickness of the oxide film exceeds 2000 nm, a light reflection tendency emerges in which the brightness L* is small but the a* value is high. As a result, it appears as a light reddish-black compared to the example, and depending on the angle of light reflection, it can appear reddish-brown. On the other hand, as in Comparative Example 2, when the thickness of the oxide film is less than 100 nm, the brightness L* becomes too high (too bright), and the values ​​of a* and b* also increase, resulting in the reflection of colored light. Compared to the example, the appearance becomes closer to brown than black, and it was found that it also appears brown depending on the angle of light reflection. Furthermore, Comparative Example 3 also showed that when the oxide film thickness exceeds 2000 nm, the black appearance becomes a slightly reddish black.

[0056] From the results of the comparative examples above, it was found that the thickness of the oxide film needs to be greater than 100 nm, and also less than 2000 nm. Furthermore, from the results of the examples above, it was found that the thickness of the oxide film is preferably between 320 nm and 1870 nm.

[0057] Furthermore, it can be seen that the distribution of the numerical range of preferred film thickness for lock pins made of nickel-based stainless steel shown in Examples 1-16 to 1-21 and the distribution of the numerical range of preferred film thickness for lock pins made of manganese-based stainless steel shown in Examples 2-16 to 2-21 show that the distribution of preferred numerical ranges for nickel-based materials is slightly shifted towards smaller film thicknesses than that for manganese-based materials. In other words, when the stainless steel material of lock pins 21 and 31 contains 10% to 14% nickel by weight, it is preferable that the thickness of the oxide film on the surface of lock pins 21 and 31 is 320 nm to 1260 nm. On the other hand, when the stainless steel material of lock pins 21 and 31 contains 13% to 17% manganese by weight, it is preferable that the thickness of the oxide film on the surface of lock pins 21 and 31 is 440 nm to 1870 nm. Generally, the formation of a black oxide film on stainless steel materials through chemical conversion treatment is related to the fact that the film thickness increases with longer immersion time in the chemical conversion treatment solution (such as a chromic acid-based solution or a caustic soda-based solution). Therefore, as described above, if the numerical range of the optimal film thickness is known, the appropriate range of immersion time in the chemical conversion treatment solution can be easily estimated, and the above-mentioned technical knowledge is advantageous in terms of improving the efficiency of the manufacturing process.

[0058] Next, although the test specimen was not a locking pin (it was a slide fastener element in shape) (and the material was ferritic stainless steel (SUS430)), the film thickness was analyzed in the same way, and the results will be explained using Figures 23 to 28.

[0059] Ferritic stainless steel is an alloy of iron and chromium and does not contain nickel, which gives it the disadvantage of being prone to oxidation (rusting). On the other hand, ferritic stainless steel is less prone to work hardening and easier to process than austenitic stainless steel, making it advantageous for use in parts with high processing rates, such as fastener elements, which are forged. In this respect, it differs from the situation with lock pins, where using austenitic stainless steel is advantageous, but in order to achieve a unified black color for the entire slide fastener, it is important to comprehensively analyze and consider the tendency of blackening due to surface treatment of fastener elements in conjunction with the tendency of blackening of lock pins and sliders.

[0060] Figures 23 to 28 show the results of analyzing test specimens (slide fastener element-shaped specimens) made from ferritic stainless steel (SUS430), similar to Examples 3-1 to 3-15 shown in Table 3 above. For convenience, the sample analyzed in Figure 23 will be referred to as Example 3-16, the sample analyzed in Figure 24 as Example 3-17, the sample analyzed in Figure 25 as Example 3-18, the sample analyzed in Figure 26 as Example 3-19, the sample analyzed in Figure 27 as Example 3-20, and the sample analyzed in Figure 28 as Example 3-21. Here, we will explain in detail the relationship between the implementation samples of Examples 3-1 to 3-15 shown in Table 3 and the implementation samples of Examples 3-16 to 3-21 from which film thickness data was obtained by Auger electron spectroscopy. Examples 3-1 to 3-5 in Table 3 and Examples 3-16 (Figure 23) and 3-17 (Figure 24), from which film thickness data was obtained by Auger electron spectroscopy, are implementation samples of a group that underwent chemical conversion treatment as part of the same manufacturing lot. In other words, when chemical conversion treatment is performed on small parts such as lock pins, several hundred lock pins are treated at once. From this manufacturing lot of several hundred units treated at once, the seven lock pins that were arbitrarily sampled for obtaining measurement data are Examples 3-1, 3-2, 3-3, 3-4, and 3-5 in Table 3, and Examples 3-16 (Figure 23) and 3-17 (Figure 24), from which film thickness data was obtained by Auger electron spectroscopy. Similarly, Examples 3-6, 3-7, 3-8, 3-9, and 3-10 in Table 3, along with Examples 3-18 (Figure 25) and 3-19 (Figure 26), for which film thickness data was obtained by Auger electron spectroscopy, belong to the same group of products that underwent chemical conversion treatment as part of the same manufacturing lot. Similarly, Examples 3-11, 3-12, 3-13, 3-14, and 3-15 in Table 3, along with Examples 3-20 (Figure 27) and 3-21 (Figure 28), for which film thickness data was obtained by Auger electron spectroscopy, belong to the same group of products that underwent chemical conversion treatment as part of the same manufacturing lot.

[0061] The definition of the oxide film thickness, as read from the measurement data in Figures 23 to 28, is the same as the method described in Figure 6 above. Specifically, in Figure 23, the maximum value of oxygen near the surface formed on the sample is approximately 4300 on the vertical axis (Intensity), and the thickness of the oxide film is defined as 1010 nm, which is 50% of that value, or 2150. In other words, the thickness of the oxide film in Example 3-16 is 1010 nm.

[0062] Similarly, examining the thickness of the oxide film, the thickness of the oxide film in Example 3-17 shown in Figure 24 is 1070 nm. The thickness of the oxide film in Example 3-18 shown in Figure 25 is 1620 nm. The thickness of the oxide film in Example 3-19 shown in Figure 26 is 1470 nm. The thickness of the oxide film in Example 3-20 shown in Figure 27 is 2190 nm. Note that the thickness of the oxide film in Example 3-21 shown in Figure 28 is 2500 nm or more, which exceeds the range that can be measured by the device, so the thickness cannot be estimated using the same method as above. However, it can be inferred that it is approximately between 2600 nm and 2800 nm. Therefore, we will take the midpoint and estimate the thickness to be 2700 nm. The thickness distribution range of the oxide film in these six experimental samples, from Example 3-16 to Example 3-21, is between 1010 nm and 2700 nm.

[0063] Here, the shape of the fastener element is roughly a hexahedron with opposing parallel planes, and these planes tend to overlap during surface treatment with chemical solutions. Because the coloring solution does not flow easily to the overlapping surfaces, the growth of the film thickness on the overlapping surfaces is slowed. On the other hand, the shape of the lock pin is not such a hexahedron, so the coloring solution flows well across the entire surface of the lock pin. Therefore, in order to achieve uniform coloring (chemical conversion treatment) on the fastener element, the treatment time needs to be longer compared to the treatment time of the lock pin, and as a result, the oxide film formed on the surface tends to be thicker. On the other hand, the growth of the film thickness on the surface of the lock pin progresses almost uniformly overall, so uniform coloring can be achieved in a short time. In addition, ferritic stainless steel does not contain nickel, so it oxidizes more easily than austenitic stainless steel, and the rate of film thickness growth tends to be faster with surface treatment. Due to these circumstances, the oxide film thickness of fastener elements made from ferritic stainless steel tends to be thicker than the oxide film thickness of lock pins made from austenitic stainless steel. In this respect, the surface treatment of the fastener elements differs from that of the lock pins. However, in order to achieve a unified black color for the entire slide fastener, it is important to comprehensively analyze and consider the tendency for the fastener elements to become black due to surface treatment, together with the tendency for the lock pins and sliders to become black.

[0064] From the results in Figures 23 to 28 and the color measurement data shown in Table 3, it was found that for test pieces made of ferritic stainless steel (SUS430) (test pieces in the shape of slide fastener elements), if the oxide film thickness is between 1010 nm and 2700 nm, even though the color is still black, it will have a lower visible light reflectivity and a higher absorption rate, resulting in a so-called "pure black" color. From this, it was found that by using ferritic stainless steel (SUS430) not only for sliders 20 and 30, but also for slide fastener elements, and using film thicknesses within the above-mentioned preferred numerical range, it is possible to create a unified black impression for the entire slide fastener in products where the concept is for the entire product to be pure black, without the slide fastener elements standing out as a distinctly different part.

[0065] It should be noted that the present invention is not limited to the embodiments disclosed above. It is also possible to appropriately utilize, use as a substitute for, or add to technologies that are substantially the same as or have similar effects as those described in the embodiments of the present invention, as recognized by those skilled in the art. Furthermore, it is also possible to combine and implement the characteristic configurations of the above embodiments.

[0066] Furthermore, throughout this specification, the parts numbered and described in the drawings are described as the minimum necessary components in each embodiment of the present invention, and this does not mean that the present invention is composed solely of the parts numbered and described in the drawings.

[0067] Furthermore, the numerical values ​​described in this specification are based on the values ​​in the tables provided in this specification, and in principle, if there is any discrepancy in the correspondence of the numerical values, the values ​​entered in the tables should be presumed to be more accurate. [Explanation of Symbols]

[0068] 20,30: Slider 21,31: Lock pin 23,33: Slider body 25,35: Pull handle

Claims

1. A slider (20, 30) for a slide fastener, comprising a slider body (23, 33), a pull tab (25, 35), and a locking pin (21, 31), The aforementioned lock pins (21, 31) are made of stainless steel. A black oxide film is formed on the surface of the lock pins (21, 31). A slider for a slide fastener, characterized in that the lightness L* on the surface of the lock pins (21, 31) as defined in the CIELAB color space as defined in JIS Z8781-4 (2013) is 31.70 ≤ L* ≤ 35.90, and the value of a* is -0.708 ≤ a* ≤ 1.

929.

2. The value of b* on the surface of the lock pin (21, 31), as defined in the CIELAB color space as defined in JIS Z8781-4 (2013), is -2.428 ≤ b* ≤ 0.

466. A slider for a slide fastener according to claim 1, characterized by the above.

3. The stainless steel material of the lock pins (21, 31) is an austenitic stainless steel material containing 10 to 14% nickel by weight, On the surface of the lock pins (21, 31), the lightness L* defined in the CIELAB color space as defined in JIS Z8781-4 (2013) is 31.70 ≤ L* ≤ 34.16, the value of a* is 0.369 ≤ a* ≤ 1.736, and the value of b* is -2.428 ≤ b* ≤ 0.

466. A slider for a slide fastener according to claim 1, characterized by the above.

4. The stainless steel material of the lock pins (21, 31) is an austenitic stainless steel material containing 13 to 17% manganese by weight percentage, On the surface of the lock pins (21, 31), the lightness L* defined in the CIELAB color space as defined in JIS Z8781-4 (2013) is 33.04 ≤ L* ≤ 35.90, the value of a* is -0.708 ≤ a* ≤ 1.929, and the value of b* is -2.388 ≤ b* ≤ -1.

495. A slider for a slide fastener according to claim 1, characterized by the above.

5. The slider body (23, 33) is black, As defined in the CIELAB color space as specified in JIS Z8781-4 (2013), The difference ΔL* between the brightness L* of the slider body (23, 33) and the brightness L* of the lock pin (21, 31) is ΔL* ≤ 8.

54. The difference Δa* between the a* value of the slider body (23, 33) and the a* value of the lock pin (21, 31) is 0.03 ≤ Δa* ≤ 2.

67. A slider for a slide fastener according to claim 1 or 2, characterized by the above.

6. The slider body (23, 33) is black, As defined in the CIELAB color space as specified in JIS Z8781-4 (2013), The difference ΔL* between the brightness L* of the slider body (23, 33) and the brightness L* of the lock pin (21, 31) is ΔL* ≤ 6.

79. The difference Δa* between the value of a* of the slider body (23, 33) and the value of a* of the lock pin (21, 31) is 1.11 ≤ Δa* ≤ 2.

47. A slider for a slide fastener according to claim 3, characterized by the above.

7. The slider body (23, 33) is black, As defined in the CIELAB color space as specified in JIS Z8781-4 (2013), The difference ΔL* between the brightness L* of the slider body (23, 33) and the brightness L* of the lock pin (21, 31) is ΔL* ≤ 8.

54. The difference Δa* between the a* value of the slider body (23, 33) and the a* value of the lock pin (21, 31) is 0.03 ≤ Δa* ≤ 2.

67. A slider for a slide fastener according to claim 4, characterized by the above.

8. A slide fastener comprising a slider for slide fasteners according to any one of claims 1 to 4, wherein the elements of the slide fastener are manufactured from a ferritic stainless steel material, and the lightness L* of the elements as defined in the CIELAB color space as defined in JIS Z8781-4 (2013) is 29.67 ≤ L* ≤ 36.24, the value of a* is -0.63 ≤ a* ≤ 0.76, and the value of b* is 0.42 ≤ b* ≤ 1.

22.

9. A slide fastener comprising a slider for a slide fastener as described in claim 8, wherein the slider body (23, 33) is black, A slide fastener characterized in that the difference ΔL* between the lightness L* of the element as defined in the CIELAB color space as defined in JIS Z8781-4 (2013) and the lightness L* of the slider body (23, 33) is ΔL* ≤ 8.94, and the difference in the value of a* Δa* is 0.11 ≤ Δa* ≤ 1.

49.

10. A slider for a slide fastener according to claim 1 or 2, characterized in that the thickness of the oxide film on the surface of the lock pins (21, 31) is 320 nm or more and 1870 nm or less.

11. The slider for a slide fastener according to any one of claims 1, 3, or 6, characterized in that the stainless steel material of the lock pins (21, 31) is an austenitic stainless steel material containing 10% to 14% nickel by weight, and the thickness of the oxide film on the surface of the lock pins (21, 31) is 320 nm to 1260 nm.

12. The slider for a slide fastener according to any one of claims 1, 4, or 7, characterized in that the stainless steel material of the lock pins (21, 31) is an austenitic stainless steel material containing 13% to 17% by weight of manganese, and the thickness of the oxide film on the surface of the lock pins (21, 31) is 440 nm to 1870 nm.

13. A slide fastener according to claim 8, characterized in that the thickness of the oxide film on the elements of the slide fastener is 1010 nm or more and 2700 nm or less.

Images