Timepiece, jewellery or gemstone jewellery made of gold

Abstract

To provide a gold alloy that has the same bronze hue as the 9-carat gold alloy and exhibits improved tarnish resistance.SOLUTION: A gold alloy contains 73 wt.% to 77 wt.% of gold, 5 wt.% to 9.9 wt.% of silver, 1 wt.% to 4.9 wt.% of palladium, and 10 wt.% to 18 wt.% of copper. The gold alloy may further contain up to 0.05 wt.% of one or more elements selected from iridium, rhenium, and ruthenium. A timepiece, jewelry, or gemstone jewelry made of the gold alloy is also provided.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention provides an 18 karat gold alloy with an attractive bronze hue and improved tarnish resistance. Regarding.

[0002] The invention further relates to timepieces, precious stones or gemstone jewelry made from this gold alloy. do. [Background technology]

[0003] A zinc-free 9 carat gold alloy is known from European Patent Application Publication No. 19193469. 37.5% to 38.5% by weight of gold, with a total percentage of 4% to 32% by weight. Palladium and / or silver, 25% to 54% by weight of copper, 0% to 10% by weight of gas This alloy has excellent deformability and improved stress corrosion and tarnish resistance. Furthermore, it has an attractive bronze-like hue and is free of the drawbacks associated with oxidation of this material. .

[0004] Improved tarnish resistance compared to standard 9-karat gold alloy, but tarnish is still observed over time This discoloration can result in the beautiful bronze-like color of objects made from this alloy. The phase changes. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] European Patent Application Publication No. 19193469 Summary of the Invention [Problem to be solved by the invention]

[0006] The object of the present invention is to provide a gold alloy having the same bronze hue as the prior art 9 carat gold alloy and being tarnish-resistant. The goal is to develop improved gold alloys. [Means for solving the problem]

[0007] For this purpose, the chemical composition of the gold alloy has been adapted. is an 18-karat alloy containing silver, palladium, and copper.

[0008] More specifically, the gold alloy is 73% to 77% by weight gold, 5% to 9.9% by weight silver, % of silver, 1% to 4.9% by weight of palladium, and 10% to 18% by weight of copper. Has.

[0009] Advantageously, the present invention is a composite of 73% to 77% by weight of gold, 5% to 9.9% by weight of silver, and 100% by weight of silver. % to 4.9 wt. % palladium, 10 wt. % to 18 wt. % copper, and 0 to 0.05 wt. % % by weight of one or more elements selected from iridium, rhenium and ruthenium Regarding gold alloys.

[0010] According to specific embodiments of the present invention, the gold alloy has one or a suitable combination of the following characteristics: It has the function. 73.5% to 77% gold, 5.5% to 9.9% silver, 1.5% % to 4.9 wt. % palladium and 11 wt. % to 18 wt. % copper. · 73.5% to 76.5% by weight gold, 5.5% to 9.9% by weight silver, 1. Contains 5% to 4.9% by weight of palladium and 11% to 16% by weight of copper . 74% to 76.5% by weight of gold, 6% to 9.9% by weight of silver, 2% to It contains 4.9% by weight of palladium and 12% to 16% by weight of copper. · 74% to 76% by weight gold, 6% to 9.5% by weight silver, 2% to 4. It contains 9% by weight of palladium and 12% to 15.5% by weight of copper. Maximum 0.05% by weight of one or more elements selected from iridium, rhenium and ruthenium contains multiple elements. CIELAB color space a * Values 3 to 9, b * The value is between 12 and 18. CIELAB color space a * Values 5.5 to 8, b * The value is between 14 and 17. The L value in the CIELAB color space is between 80 and 90. Hardness HV1 of 140 to 185, preferably 155 to 180.

[0011] The present invention further relates to timepieces, precious stones or gemstone jewelry made from the alloy.

[0012] In use, timepieces, precious stones or gemstone jewellery made with this alloy may be Improved resistance to tarnishing over time compared to those made using 9-karat alloys It has been found to be more resistant to tarnish than other 18-karat alloys. It has been improved.

[0013] In terms of color, the 9 karat alloy of the prior art and the 18 karat alloy of the present invention are similar by visual inspection. It has a similar hue. [Effects of the Invention]

[0014] Further features and advantages of the present invention will become apparent from the following detailed description, illustrated by way of non-limiting example and with reference to the accompanying drawings, in which: This will become clear from the description of the preferred embodiment. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 shows a timepiece including a middle case made using a gold alloy according to the present invention. [Figure 2] FIG. 2 shows the fading curves for the alloy of the present invention (INV) and two 18 carat alloys of the prior art (2N, 3N). DETAILED DESCRIPTION OF THE INVENTION

[0016] The present invention is more particularly intended for application in the watchmaking, gem or gemstone jewellery sector. Therefore, timepieces, jewels or gems made from this alloy are also included. The term "timepiece" refers to the middle case, back case, Bezel, push buttons, bracelet links, dial, hands, or dial indexes This refers both to external parts such as the case, and to parts of the movement such as the plate, bridges or balance. It will be understood that, by way of example, the timepiece is a middle case 1 as shown in FIG.

[0017] The gold alloy according to the present invention is 73 to 77% by weight gold, 5 to 11% by weight silver. 1 to 4.9% by weight of palladium and 10 to 18% by weight of copper. This alloy is free of nickel, cobalt, iron and manganese.

[0018] Advantageously, the gold-based alloy contains between 73.5% and 77% by weight of gold, between 5.5% and 9.9% by weight of copper. % by weight of silver, 1.5% to 4.9% by weight of palladium, and 11% to 18% by weight of Contains % copper.

[0019] Preferably, the gold-based alloy is 73.5% to 76.5% by weight gold, 5.5% to 6.5% by weight silver, 9.9% by weight of silver, 1.5% to 4.9% by weight of palladium, and 11% to 1 Contains 6% by weight of copper.

[0020] More preferably, the gold-based alloy is 74% to 76.5% gold, 6% to 9.9% silver, 2% to 10% copper, 2% to 10% nickel ... It contains 4.9% to 4.9% palladium and 12% to 16% copper.

[0021] Particularly preferably, the gold-based alloy is 74% to 76% by weight gold, 6% to 9.5% by weight silver, % by weight of silver, 2% to 4.9% by weight of palladium, and 12% to 15.5% by weight of Contains copper.

[0022] Additionally, the gold-based alloy may contain from 0 to 0.05 weight percent (inclusive) iridium. containing one or more elements selected from the group consisting of ruthenium, rhenium, and ruthenium, and The weight percent ranges cover the total proportion of one or more of these elements. Advantageously, the alloy contains 0. It contains 0.025% by weight of iridium.

[0023] To prepare gold alloys, the various elements of the composition are melted together before casting. Deform the cast ingot with a work hardening rate of 75% or more distributed among the passes, and perform intermediate annealing at 550°C. The heating is carried out at temperatures ranging from 0°C to 750°C for 5 to 30 minutes. Anneal at 650°C for 30 minutes. After cooling, the blank is machined to a specific size. Cut into pieces.

[0024] The alloy obtained after deformation and annealing conforms to the CIELAB color space (CIE No. 15, ISO 7724 / 1, DIN5033 Teil7, ASTM E-1164 standards) * Values between 3 and 9, preferably between 5.5 and 8, b *Values are 12 to 18, preferably 14 to 1 7 and a * and b * The values together define the color of the alloy, and the L value is between 80 and 90. Ri, La * b * The values together define the color of the alloy. More specifically, according to the present invention, Define the hue a * and b * I pay attention to the value.

[0025] These alloys have a hardness of 140 to 185 HV1, preferably 155 to 180 HV1. It has.

[0026] Table 1 shows the reference 9 carat gold alloys of EP 19193469, and The compositions of the five 18-carat gold alloys of the present invention are shown by weight. The hardness (HV1) is also shown in Table 1. * a * b * The color measurement values are from Konica Minolta CM-2600d Measured with a spectrophotometer under a D65 illuminant and an observation angle of 10°. Delta E and Delta C values Each shows the color difference and saturation difference relative to the 9K reference. * b * Calculate based on the value. ref , a * ref and b * ref Reference 9 carat gold alloy Refers to the value of ΔE=[(L ref -L) 2 +(a * ref -a * ) 2 +(b * ref -b * ) 2 ] 1 / 2

[0027] Delta C is a * b * Calculate based on the value. ΔC=[(a * ref -a * ) 2 +(b * ref -b * ) 2 ] 1 / 2

[0028] [Table 1]

[0029] a * value and b * The values are very close, a * The values ranged from 6.4 to 7.8, compared with the reference value of 6.7. * The values are 14.7 to 16.4, compared to the reference value of 15. The alloy has the same bronze hue. Discoloration is assessed visually after exposure to ambient air for several days. In contrast to the prior art 9 carat gold alloy, which changes color substantially, the 1 carat gold alloy of the present invention The 8-karat gold alloy maintains its attractive bronze hue without tarnishing. as well as two prior art 18 carat gold alloys, namely 75 wt. % Alloy 2N, containing 75% gold, 12.5% silver and 9% copper by weight; Comparative fading tests were carried out on alloy 3N, which contains 12.5% copper and 12.5% silver by weight. The color test is performed by immersing the sample in a saturated aqueous solution of sodium chloride at 70°C for several days. The color fading was defined as Delta E and was monitored by colorimetric measurements performed under the same conditions as above. As shown in Figure 2, the new gold alloy exhibited a significant improvement in solubility compared to the prior art 18-karat gold alloys 2N and 3N. This significantly improves colorfastness.

[0030] The alloy according to the invention has a hardness HV1 of 158 to 175 in the annealed state and is easy.

[0031] Thus, the new gold alloy has an attractive bronze hue and is less likely to tarnish over time.

Claims

1. 73% to 77% by weight gold, 5% to 9.9% by weight silver, 1% to 4.9% by weight % palladium by weight, and 10% to 18% copper by weight.

2. 73.5% to 77% by weight gold, 5.5% to 9.9% by weight silver, 1.5% by weight % to 4.9% by weight of palladium and 11% to 18% by weight of copper.

2. The gold alloy of claim 1 .

3. 73.5% to 76.5% by weight gold, 5.5% to 9.9% by weight silver, 1.5 % to 4.9% by weight of palladium and 11% to 16% by weight of copper. The gold alloy according to claim 1 or claim 2,

4. 74% to 76.5% by weight of gold, 6% to 9.9% by weight of silver, 2% to 4% by weight 9% by weight of palladium and 12% to 16% by weight of copper. The gold alloy of any one of claims 1 to 3.

5. 74% to 76% by weight gold, 6% to 9.5% by weight silver, 2% to 4.9% by weight % by weight of palladium and 12 to 15.5% by weight of copper. The gold alloy of any one of claims 1 to 4.

6. One or more elements selected from iridium, rhenium and ruthenium up to 0.

6. The gold alloy according to claim 1, wherein the gold alloy contains 0.05% by weight of the gold alloy. alloy.

7. a in CIELAB color space ＊ Values are 3 to 9, b ＊ The value is between 12 and 18. The gold alloy of any one of claims 1 to 6.

8. a in the CIELAB color space ＊ Values range from 5.5 to 8, b ＊ The value must be between 14 and 17.

8. The gold alloy according to any one of claims 1 to 7.

9. 10. The method according to claim 1, wherein the L value of the CIELAB color space is between 80 and 90.

9. The gold alloy of claim 8.

10. It is characterized by having a hardness HV1 of 140 to 185, preferably 155 to 180.

10. The gold alloy of claim 1, wherein the gold alloy is a hydroxyapatite or hydroxyapatite.

11. A timepiece, jewel or jewelry made from the gold alloy of any one of claims 1 to 10. Gemstone jewelry.

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