JPS58204141A - Low karat gold alloy for casting assuming gold color - Google Patents

Abstract

PURPOSE:To obtain the titled gold alloy consisting of prescribed percentages of Au, Ag, Pd, Cu and In, assuming a gold color comparable to that of a high karat gold alloy in spite of the low Au content, and having high corrosion resistance. CONSTITUTION:This low karat gold alloy for casting assuming a gold color consists of, by weight, 30-50% Au, 5-35% Ag, 5-15% Pd, 10-20% Cu and 10- 18% In. The physical properties of the alloy can be further improved by adding one or more among <=0.1% Ir, <=2% Pt and 5% Zn to the alloy. The corrosion resistance and gold color of the gold alloy are comparable to those of a 14k. gold alloy, and this alloy can be widely used as a gold alloy for casting an inlay, a crown, a bridge, etc. for dental use, accessories, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a low karat gold alloy for casting, and more particularly, to a low karat gold alloy for casting, which exhibits a golden color similar to that of high-strength rat gold alloys and has high corrosion resistance despite having a low gold content. The present invention relates to low karat gold alloys for industrial use.

For example, gold alloys used as cast prosthetic materials such as dental inlays, crowns, and bridges use gold-m-m-palladium as a base alloy and incorporate appropriate amounts of platinum, indium, zinc, etc. to improve corrosion resistance. mechanical strength,
Molten IA! 1. Adjusting the temperature, etc. These gold alloys exhibit a beautiful golden color and have good corrosion resistance, so
It can be said that it is extremely suitable for the above-mentioned uses. However, as the price of gold has been on the rise,
In order to cope with such social conditions, research into low-carat gold alloys with a low gold content has been actively conducted.
No. 5B-4720, No. 55-58844, Special Publication No. 5
No. 6-47940, No. 56-47941, etc. have been proposed. However, these low-karat gold alloys have fatal flaws in that they do not exhibit the golden color characteristic of gold alloys and have poor corrosion resistance, making it impossible to obtain commercial value as precious metal materials.

The present inventors focused on the above-mentioned circumstances and
＋＊”r”Ah, red 8. '14 We have been conducting intensive research in an effort to develop a casting gold alloy that exhibits a comparable golden color and corrosion resistance. The present invention was completed as a result of such research, and its composition is as follows: Gold: 80-5
0% (weight: the same below), silver: 5-85%, palladium: 5-15%, copper: 10-20%, and indium: 1
0 to 18q6] or these elements, iridium: 0.1 or less, remainder: 2 or less, and zinc 25q
The gist lies in that it contains at least one element selected from the group consisting of 6 or less and exhibits a golden color and high corrosion resistance comparable to that of a 14-strength gold alloy.

The reasons for determining the types and blending ratios of alloying elements in the present invention will be explained below.

Kin2 is an essential element for an 80-50 alloy, but in order to achieve the original objective of reducing costs by lowering the carat weight, the upper limit was set at 50. On the other hand, the lower limit was set to ensure a golden color and high corrosion resistance comparable to that of a 14-strength gold alloy, and if it is less than 80%, it will not be satisfied even if other alloy components are appropriately adjusted as described below. You won't be able to get the golden color and corrosion resistance you want.

Silver = 5 to 85 Silver is an element that alloys well with gold, copper, and palladium. In other words, it is a basic element that does not impair physical properties and is necessary to form a gold-colored, highly corrosion-resistant alloy to be described later. That is, for the same reason as gold, when gold and other elements are added, the composition range can be limited to 5 to 85 chi as base alloy elements.

5 to 15% palladium, which gives the alloy a golden color and increases its corrosion resistance, as well as increases its melting temperature and improves its mechanical strength.In order to effectively demonstrate these effects, it must be included I have to. However, if the amount is too high, the golden color will diminish and the color will turn white, and the melting temperature will be too high, making it rather brittle, so it is necessary to keep it below 15%.

Indium: 10-18 This is the most important element in the present invention, and must be contained in an amount of 101 or more in order to exhibit a stable golden color even when the gold content is low. Moreover, if it is too large, the melting temperature and temperature of the alloy will be low (too much will cause poor mechanical strength, so it is necessary to keep it below 18%).

Copper: 10 to 20 Copper is an extremely important element for improving strength, and must be contained in copper of 10 to 20 to achieve the purpose. In addition, if the amount is too high, the corrosion resistance will decrease and the golden color will be lost after a short period of use, and the alloy will become excessively hard and have poor workability, so it is necessary to keep the amount below 20.

Essential component 1 in the present invention! The above is the same, but if necessary, one or more elements selected from the group consisting of iridium with a coefficient of 0.1 or less, platinum with a coefficient of 21 or less, and zinc with a coefficient of 5 or less may be added. , the physical properties of the gold alloy can be further improved.

That is, as is well known, iridium is effective in enhancing the effect of grain refinement in gold alloys.

If it exceeds 0.1 inch, it is not preferable because it damages the uniform M weave of the same bath alloy and unnecessarily increases the price and pressure. Platinum is expected to have the same effect as iridium, and is effective in increasing the strength of the alloy, but if it exceeds 2 or more, there will be a slight increase in the number of cavities.
Moreover, it is not desirable because it only increases the price unnecessarily. Zinc also refines the grains of cast alloys, acts as a matrix strengthener and deoxidizer, and is extremely useful in improving the physical properties of gold alloys.

However, if it is too large, the elongation rate of the alloy will decrease, so it must be kept below a factor of 5.

Although the contents of the individual constituent elements of the gold alloy according to the present invention are as described above, it is not necessarily appropriate to define the effects of these constituent elements only by their respective contents, and the actual When formulating, the optimum value should be selected and determined from among the above-mentioned preferred content ratios, while also considering the interaction of all the constituent elements.

Next, in order to further clarify the structure and effects of the present alloy, the differences will be explained while comparing it with known gold alloys.

Table 1 shows the composition, physical properties, and color 1 of known gold alloys and the gold alloy of the present invention.

Table 1 can be thought of as follows.

Base metal: I61 is a commercially available dental 14-strength metal alloy, alloy A2 is the same dental low karat gold alloy, alloy A3 is the same dental silver alloy, and A1 has a high Au content, so after polishing. The alloy surface has a golden color, but the surface skin immediately after casting is black. Even when the Au content is high in this way, the surface texture immediately after casting cannot necessarily be said to be good. O and A
The color tone of Rin 2 and silver alloy A8, which have a low u content, is poor immediately after casting, and the surface texture after polishing does not exhibit a golden color. Sho A
The reason why the PD content is increased as the U content decreases is to improve corrosion resistance.

Alloys A4 and 5 are low-karat gold alloys, which were developed for use in baking porcelain materials, have high PD and PT contents, and are naturally white in color and are highly soluble alloys. In other words, although it is a low-karat gold alloy, its purpose of use is completely different from that of the present invention.

Alloys A6-8 were developed as low-karat gold alloys for casting, and although they are inexpensive, they do not have the golden color characteristic of gold alloys and have low commercial value.

Alloys I69-11 do not use Ag as an alloy component and are made of Ga.
This is a special gold alloy that has been added to improve its quality, but its color tone is no different from known low-karat gold alloys.

Alloy A12 was invented for decorative purposes. This does not contain in in its constituent elements, has a high Cu content, and has a low Pd content of 8, so it cannot be expected to have high corrosion resistance for dental use.

Alloy metal 18 is a silver alloy that does not contain any Au, and naturally does not have a golden color.

In this case, In is blended for the purpose of improving the corrosion resistance of the silver alloy, and the effect K unique to the present invention (the effect of promoting golden color development by AuK) as described above cannot be expected. (Nor.

Alloys 414 to 16 are comparative examples in which the cumulative amount of any of the constituent elements is outside the specified range.Alloy 1614 has a very confusing color tone due to a lack of ln, and alloy 415 has poor corrosion resistance due to a lack of pd. bad. Furthermore, since the alloy flat plate 16 lacks Cu particles, its physical properties, especially its elongation rate, are low and it cannot be put to practical use.

On the other hand, base metals 1617 to 20 are die-cast examples that satisfy all the requirements of the present invention, and have excellent mechanical properties on average, as well as exhibiting a yellow color on the surface immediately after casting. It has a beautiful golden color. Furthermore, for alloys 417 to 28, a discoloration test (87℃) according to JIS-T6118 was conducted.
(observation of discoloration after 72 hours of immersion in a 0.1 molar sodium sulfide aqueous solution), no discoloration was observed, and it was confirmed that the material had excellent corrosion resistance.

The present invention is generally constructed as described above, and provides a casting alloy that has corrosion resistance and golden color comparable to that of 14-karat gold alloys, even though it is a low-karat gold alloy with a low gold content. I ended up getting it. Therefore, it can be widely used as a casting gold alloy for dental inlays, crowns, bridges, decorations, etc.

Applicant: Sankin Kogyo Co., Ltd.

Claims (1)

[Claims] 111 gold: 80 to 50 weight (weight: same below), silver = 5
~86%, Palladium: 5-15%, Copper: 10-20%
and indium: 10 to 18% A low karat gold alloy for casting, characterized by a good strength, golden color and high corrosion resistance. (2) Gold = 80-50 (weight: same below), Silver: 5
~85chi, palladium: 5~15q6, copper: 10~20
Indium: 10 to 18%, Iridium: 0.
At least one element selected from the group consisting of 1% or less, platinum = 2 or less, and zinc: 5 or less, golden color? i! 1. A low karat gold alloy for casting, characterized by having corrosion resistance.