JP2017110963A - Exterior parts of watches or accessories - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide exterior parts of watches or accessories, having a hardness large enough to prevent scratches or surface shape deformations caused by contacts with clothes or items when the exterior parts are being worn by persons, a decorativeness bright enough to seal surface somberness, and an affinity large enough not to cause metallic allergy on skins.SOLUTION: The exterior parts of watches or accessories according to the present application are made of an alloy of titanium and iron, which has a larger lightness at CIELab (L*a*b*colorimetric system) than that of 100% iron.SELECTED DRAWING: Figure 1A

Description

  The present invention relates to a timepiece or an exterior part of a decorative object made of a titanium (Ti) -iron (Fe) alloy body.

  A wristwatch case which is an exterior of a wristwatch is required to have durability against rubbing and impact and a decorative property as a decoration, and in particular, a high-grade product employs a metal exterior rather than a plastic. Furthermore, in the case of a metal sheath, since it is in direct contact with the skin for a long time, a metal that does not easily cause metal allergy to the skin is desirable.

  Compared to metals such as stainless steel, titanium is lighter and easier to wear than metals such as stainless steel, and the amount of ions eluted into sweat on the skin is low, causing metal allergies to the skin. It is known to be difficult, and is attracting attention as a skin-friendly metal exterior.

  Furthermore, titanium is also interested as a material for decorative objects such as bracelets and rings that come into contact with the skin for a long time.

  However, pure titanium used in watch cases has a problem that its surface is soft and easily scratched, and it has a disadvantage that its brightness is low and decorativeness is inferior to stainless steel, which is the mainstream of watch cases. was there.

As a technique for improving the hardness of titanium to be hardened, a method using a titanium-iron alloy in which iron, which is an inexpensive metal, is dissolved in titanium is considered. (For example, Patent Document 1)
Hereinafter, the titanium-iron alloy shown in Patent Document 1 will be described.
Patent Document 1 is directed to a decorative part using a titanium alloy, particularly a wristwatch exterior part.

  Titanium is used as a metal or alloy for wristwatches because of its lightness and skin allergies. However, since it has low hardness and is easily damaged, it needs to be hardened, and the surface condition is limited to gray color. There was a problem with lack of feeling.

  In Patent Document 1, a titanium alloy in which iron is mixed with titanium as a base material is manufactured, and the hardness and mirror surface state of each titanium alloy are evaluated. As a titanium alloy for a watch exterior, the hardness is Hv250 or more, after buffing The condition that the high surface property is good is imposed, and iron is 0.5 to 5%, which is a blending ratio that satisfies this condition.

  As described above, Patent Document 1 is an invention aimed at increasing the hardness of a titanium alloy of a wristwatch exterior part. However, the hardness and specularity of a titanium-iron alloy depends on the iron blending ratio. The titanium alloy is said to be suitable for a wristwatch exterior part when the iron blending ratio is 0.5 to 5%.

JP-A-7-62466 (first page, FIG. 1)

  The wristwatch exterior part material according to Patent Document 1 has been improved in terms of specularity, but has never been studied from the viewpoint of surface brightness, which creates the brightness of the alloy itself, that is, the beauty of the member. Absent.

  Therefore, a titanium-iron alloy obtained by dissolving iron in titanium at a blending ratio of 5% described in Patent Document 1 is good in terms of hardness and specularity, but the brightness of the alloy itself is inferior. Therefore, it has a drawback that it is insufficient for use as an exterior part of a watch or a decorative object that requires high brightness.

  That is, the exterior part of the timepiece or the decorative object according to the present invention has a surface in contact with the skin, which is evaluated for fastness against rubbing and impact, and a surface which is evaluated as a decorative object.

  For this reason, the exterior parts of watches or ornaments are rubbed with clothes, struck with objects, sometimes dropped and collided with the floor, etc., resulting in scuffing and surface deformation due to external forces. Hardness not required is required.

  In addition, since the exterior parts of watches or ornaments are always exposed to the eyes, beauty, that is, glittering of the surface, brightness is required, and metallic materials that give a dull impression are avoided, such as stainless steel There is a need for metals that exhibit bright surface properties.

  An object of the present invention is to solve the above problems. In other words, during use while worn on the human body, it has hardness that prevents abrasions and surface deformation caused by contact with clothes and objects, decorativeness with a bright texture that does not make the surface feel dull, and skin It is an object to provide an exterior part of a watch or an ornament having an affinity that does not cause metal allergy.

  In order to solve the above problems, the exterior part of the timepiece or the ornament of the present invention is made of an alloy of titanium and iron, and the brightness in CIELab (L * a * b * color system) is 100. It is characterized by its alloy being higher than% iron.

  With the above configuration, it is possible to provide a bright exterior component that does not cause metal allergy to the skin and does not give a dull feeling to the surface.

  Furthermore, the Vickers hardness of the alloy of titanium and iron is preferably 400 or more.

  The iron blending ratio of the alloy of titanium and iron is preferably more than 30% by weight and less than 100% by weight.

  More preferably, the iron compounding ratio of the alloy of titanium and iron is more than 30% by weight and 90% by weight or less.

  In this way, the exterior part is less likely to be scratched or deformed while maintaining a bright texture.

  According to the present invention, a watch or decoration that prevents a scratch or surface shape deformation caused by contact with clothing or an object during wearing, has a bright texture that does not make the surface feel dull, and does not cause metal allergy to the skin. The exterior part of a thing can be obtained.

It is a graph which shows the relationship between the brightness of a titanium-iron alloy in embodiment of this invention, and an iron compounding ratio. It is a table | surface which shows the relationship between the brightness of a titanium-iron alloy in embodiment of this invention, and an iron compounding ratio. It is a graph which shows the relationship between the Vickers hardness of the titanium-iron alloy in embodiment of this invention, and an iron compounding ratio. It is a table | surface which shows the relationship between the Vickers hardness of the titanium-iron alloy in embodiment of this invention, and an iron compounding ratio. It is a perspective view which shows the top of the wristwatch band as an exterior part of the timepiece in the embodiment of the present invention. It is a perspective view which shows a part of wristwatch band as an exterior part of the timepiece in the embodiment of the present invention. It is a schematic diagram which shows the structure of the vacuum arc melting apparatus used by this invention.

  Hereinafter, specific embodiments of the exterior part of the timepiece or the ornament of the present invention will be described in detail with reference to the drawings.

  In the description, a wristwatch band will be described as an example.

(Description of manufacturing procedure of titanium-iron alloy)
The manufacturing procedure of the titanium-iron alloy of the present invention will be described with reference to FIG. First, in order to clarify the iron blending ratio and the characteristics of the titanium-iron alloy in the titanium-iron alloy of the present invention, a titanium-iron alloy in which the iron blending ratio with respect to titanium is changed from 0% by weight to 100% by weight. It was produced using a vacuum arc melting method.

  Five test pieces were prepared for each sample ratio. In each test piece, titanium and iron were weighed so that the total weight of titanium and iron was 10 g. For example, when the iron blending ratio is 40% by weight, 6 g of titanium and 4 g of iron.

  FIG. 4 is a schematic configuration diagram of the vacuum arc melting furnace 40. The main components are the vacuum chamber 41, the copper hearth 43 on which the arc discharge electrode 42 and the material of the titanium-iron alloy are disposed, and the arc discharge disposed outside the vacuum chamber 41. A power supply 45 for the gas, a gas introduction pipe 48 connected to the gas inlet of the vacuum chamber 41, and an exhaust pipe 50 connected to the exhaust port of the vacuum tank 41.

  A titanium-iron alloy was produced by the following procedure. First, a mixture 44 of titanium and iron weighed so as to have an overall weight of 10 g was put into a water-cooled copper hearth 43. Titanium used sponge titanium named after its porous shape, and iron used granular iron.

  The air in the vacuum chamber 41 is exhausted using a vacuum pump (not shown) connected via an exhaust pipe 50 and an exhaust valve 51 connected to the exhaust port of the vacuum chamber 41. After reducing the pressure to 10 kPa, the exhaust valve 51 is closed to stop the exhaust, and the gas introduction valve 49 attached to the gas introduction pipe 48 connected to the gas introduction port of the vacuum chamber 41 is opened to introduce the gas. Argon gas was introduced into the vacuum chamber 41 from an argon gas cylinder (not shown) connected to the valve 49 for use. The pressure of argon gas in the vacuum chamber 41 was set to 35 kPa by adjusting the amount of argon gas introduced.

After the introduction of the gas into the vacuum chamber 41 in the above procedure, the arc discharge electrode 42 connected by the wiring 46 from the arc discharge power supply 45 and the water-cooled copper hearth 4 connected to the wiring 47
A voltage was applied during 3 to generate arc discharge. The arc discharge acts as a so-called negative resistance and the current runs away, but the power source 45 controls the current to be constant by a current control circuit to prevent the current runaway.

  The arc discharge current flows through the raw material of the titanium-iron alloy placed on the copper hearth 43, and the raw material of the alloy melts at a high temperature. Stop arc discharge when the whole raw material melts. When the alloy cools, the top and bottom of the alloy are turned over, and arc discharge is generated again to melt the alloy material and melt the whole. Upside down and dissolution were repeated three times to uniformly dissolve the raw materials of titanium and iron.

(Evaluation to know the characteristics of titanium-iron alloy produced by the above method)
Next, evaluation was performed in order to know the characteristics of the titanium-iron alloy produced by the above method.
First, a method for measuring the brightness of the produced titanium-iron alloy will be described.

  In general, RGB, CMYK, and CIELab (L * a * b * color system) are known as methods for expressing brightness and color. CIE is an abbreviation for the International Lighting Commission. CIELab (L * a * b * color system) is designed to approximate human vision. On the other hand, RGB and CMYK are given priority to the convenience of output devices such as displays and printers.

  Since the exterior part of the timepiece or the ornament of the present invention appeals to human vision, CIELab (L * a * b * color system) that approximates human vision is suitable as an evaluation system. In CIELab (L * a * b * color system), the lightness is expressed by L * and the hue is expressed by a * and b *. L * = 0 is black, L * = 100 is white, and a large value of L * means that the object looks bright.

  Therefore, in the present invention, the brightness of the titanium-iron alloy was evaluated by the brightness (L *) according to CIELab (L * a * b * color system).

  The brightness (L *) by CIELab (L * a * b * color system) was determined by the following method. First, the spectral spectrum of the reflected light from the test piece was measured using a spectrocolorimeter. Next, based on spectral spectrum data obtained by measurement, CIE uses color matching functions x (λ), y (λ), and z (λ) defined as the spectral sensitivity of the standard observer's eyes. Integral calculation was performed to calculate three values of tristimulus values X, Y, and Z, and brightness (L *) was obtained based on these three numerical values.

  Note that the color matching function depends on the viewing angle (the size of the object), and the CIE defines the color matching function for the 2 ° visual field and the color matching function for the 10 ° visual field. In the present invention, a color matching function having a 10-degree field of view suitable for watching a watch or an ornament is employed.

(Measurement of lightness dependence of iron composition ratio)
The relationship between the lightness (L *) and the iron blend ratio in CIELab (L * a * b * color system) based on the measurement experiment results will be described with reference to FIGS. 1A and 1B.

  FIG. 1B is a table showing the blending ratios and the lightness (L *) of titanium-iron alloys prepared by changing the iron blending ratio from 0 wt% to 100 wt% in the titanium-iron alloy. In the numerical values shown in the table of FIG. 1B, the average value of the lightness (L *) obtained by measuring the above-described measurement method for five alloy test pieces prepared for each iron blending ratio is entered.

  The graph of FIG. 1A is a graph plotted from the table of FIG. 1B using the numerical value of the iron blending ratio and the average value of the lightness (L *). The horizontal axis of the graph is the iron blend ratio (% by weight), and the vertical axis is the lightness (L *). The characteristic curve L1 shows the lightness with respect to each iron blending ratio.

  Looking at the characteristic curve L1, the lightness (L *) increases as the iron blending ratio increases, and the iron blending ratio takes a maximum value at 70% by weight, and the lightness (L *) = 82.7. The lightness (L *) = 82.7 is a brightness comparable to that of stainless steel.

  In the present invention, in order to know the lightness necessary for the beauty required for the watch case, the test was conducted with the beauty of the appearance, that is, the sensual viewpoint. Specifically, the five selected sensory test personnel were allowed to see the produced titanium-iron alloy without disclosing the iron blend ratio, and the brightness of the watch case was felt for each test piece. I was allowed to judge.

  As a result of this test, the acceptable product of the appearance quality is a titanium-iron alloy in which the iron blending ratio is more than 30% by weight and less than 100% by weight, and the accepted product is indicated by ○ in the table of FIG. The product is indicated by a cross. That is, the result was that the titanium-iron alloy having an iron blending ratio of more than 30% by weight and less than 100% by weight had excellent appearance quality exceeding the brightness of 100% iron.

  When the acceptable product and the rejected product are distinguished on the characteristic curve L1 in FIG. 1A, the acceptable product is a point indicated by a circle in the characteristic curve L1 and a solid line portion, and the rejected product is a point indicated by x in the characteristic curve L1. And the dotted line part. The lightness (L *) of 100% iron is 79.9, which is indicated by a dotted line in FIG. 1A as a reference line L2, but the acceptable product has a lightness higher than the lightness of 100% iron indicated by the reference line L2. It can be seen that

(Measurement of hardness of each iron blend ratio)
Next, using FIG. 2A and FIG. 2B, the relationship between the Vickers hardness based on the measurement experiment result and the iron blending ratio will be described.

  The watch case rubs on the clothes during wearing, touches nearby objects, falls to the floor when removed, and external force is applied to the surface of the watch case. Deformation may reduce the brightness and brightness of the surface and impair the beauty. In order to prevent these problems, it is effective that the titanium-iron alloy is hard.

  In the present invention, Vickers hardness (Hv), which is widely used, is adopted as a hardness index as a method for evaluating hardness. Vickers hardness (Hv) is the area of the indentation remaining after removing the load by applying a load to an indenter made of diamond with a regular quadrangular pyramid shape and pushing it into the surface of a titanium-iron alloy specimen. It is expressed as a numerical value obtained by dividing the load (expressed in kgf units or N units) by square mm units). The harder the material, the smaller the area of the dent. Therefore, the harder the material, the higher the Vickers hardness (Hv).

  2A and 2B are a graph and a table showing a relationship between a titanium-iron alloy produced by changing the iron blending ratio from 0 wt% to 100 wt% and Vickers hardness (Hv). FIG. 2B shows the average value of Vickers hardness (Hv) obtained by measuring with the above-described measurement method for five titanium-iron alloys prepared at each compounding ratio.

  FIG. 2A is a graph plotted from the table of FIG. 2B using the numerical value of the iron blending ratio and the average value of the Vickers hardness (Hv). The horizontal axis of the graph of FIG. 2A is the iron blend ratio (% by weight), the vertical axis is the Vickers hardness (Hv), and the characteristic curve H1 indicates the hardness with respect to the iron blend ratio.

  Looking at the characteristic curve H1, the Vickers hardness (Hv) increases as the iron blending ratio increases, and reaches a maximum when the iron blending ratio is 70% by weight, resulting in Vickers hardness (Hv) = 650.

In the present invention, in order to know the hardness required for a watch case, an experiment was performed in which the surface of a titanium-iron alloy test piece was rubbed with a cloth. A cotton cloth having a bristles of 2 mm was wound around a cylinder having a diameter of 10 cm, and the surface of the test piece was rubbed with a cotton cloth in such a manner that the cylinder was rotated 5 times per second with the bristles pushed into the 0.5 mm test piece. . After rubbing continuously for 1 hour, the test piece was taken out, and it was judged whether or not it was felt that the beauty of the surface of the test piece was damaged.

  Scratch resistance was evaluated by the above test, and in FIG. 2B, acceptable products that were judged to have no loss of beauty were indicated by ◯, and unacceptable products were indicated by x. That is, the result was that a titanium-iron alloy having an iron blending ratio of 10% by weight or more with a Vickers hardness of 400 or more was excellent in scratch resistance.

  In the characteristic curve H1 of the graph of FIG. 2A, the point indicated by ◯ and the solid line portion are acceptable products, and the point indicated by x and the dotted line portion are non-acceptable products. The dotted line H2 is a reference line indicating a Vickers hardness of 400.

  From the above results, it was found that a titanium-iron alloy having an iron blending ratio of 10 wt% or more and 90 wt% or less is excellent in scratch resistance.

  From the above results, the titanium-iron alloy produced by changing the iron blending ratio from 0% by weight to 100% by weight has a lightness (L *) in the range where the iron blending ratio is more than 30% by weight and less than 100% by weight. It has excellent characteristics in appearance quality exceeding the lightness of 100% iron, and it has excellent characteristics in scratch resistance in which the Vickers hardness exceeds 400 when the iron blending ratio is 10% by weight or more and 90% by weight or less. . That is, the iron blending ratio having the characteristics of achieving both the appearance quality exceeding the lightness (L *) of 100% iron and the scratch resistance exceeding Vickers hardness of 400 is more than 30% by weight and not more than 90% by weight.

  FIG. 3 is a perspective view of a wristband showing an embodiment of the present invention, FIG. 3A shows a top 30 of the wristband, and FIG. 3B is a part 31 of the wristband that connects the wristwatch body and a buckle of the wristwatch. FIG.

  Based on the above experimental results, the wristwatch band shown in FIG. 3 is made of a titanium-iron alloy having a bright surface like stainless steel and a hardness that prevents scratching even when rubbed against clothes, and having an iron blending ratio of 50% by weight. It was manufactured and forged from the alloy, and the connecting plate 32 for connecting the watch band top 30 was also in contact with the skin, so it was manufactured using the same material.

  Since the produced wristwatch band is a titanium alloy having high affinity to a living body, even if it is worn on the arm for a long time, metal allergy does not occur on the skin. In addition, since the brightness is 82.7, which is comparable to stainless steel, it is not a dull gray of titanium but a bright texture. Further, since the Vickers hardness is as high as 650, even if the outer surface of the watch band is rubbed with clothes or hits an object, there is little generation of scratches or deformation, and the deterioration of the decorativeness of the watch band can be prevented.

  The watch or decorative exterior parts of the present invention are free from metal allergy to the skin, prevent abrasion and surface deformation caused by contact with clothing and objects during wearing, and feel a dull surface. Since it has a bright texture that does not occur, it can be applied to all watches or decorative exterior parts to be worn on the human body.

30 Watch Band Top 31 Part of Watch Band 32 Connecting Plate 40 Vacuum Arc Melting Furnace 41 Vacuum Tank 42 Arc Discharge Electrode 43 Copper Hearth 44 Titanium-Iron Alloy Material 45 Arc Discharge Power Supply

Claims (4)

  It is an exterior part of a watch or an ornament, and the material of the exterior part is an alloy of titanium and iron, and the brightness in CIELab (L * a * b * color system) is higher than that of 100% iron. A watch or decorative exterior part characterized by a higher height.   2. The exterior part of a timepiece or an ornament according to claim 1, wherein the alloy has a Vickers hardness of 400 or more.   The timepiece or decorative exterior part according to claim 1, wherein the alloying ratio of iron in the alloy is more than 30% by weight and less than 100% by weight. The timepiece or decorative exterior part according to claim 1 or 2, wherein the alloying ratio of iron in the alloy is more than 30 wt% and not more than 90 wt%.

Images