JPH05132340A - Liquid or pasty noble metal composition for enamel painting use to be applied on ceramic - Google Patents

Abstract

PURPOSE:To obtain the title composition improved in alkali resistance by formulating a liquid noble metal resinate or paste with a liquid Th resinate or paste, an adhering agent like Bi, rosin and solvent, and, as necessary, Cr and Rh. CONSTITUTION:Firstly, a noble metal compound such as terpene sulfide Au is dissolved in a solvent comprising turpentine oil, benzyl alcohol and rosin at specified weight ratio into a liquid noble metal resinate or paste. And, as sintering-preventive/alkalinity enhancer, a liquid Th resinate or paste is prepared by dissolving Th in turpentine oil. Thence, a specified amount of the liquid noble metal resinate is formulated with the Th resinate, an adhering agent like Bi, rosin and solvent, thus giving the objective composition comprising (A) 100 pts.wt. of the noble metal, (B) 1-8 pts.wt. of Th, (C) 0.02-3 pts.wt. of Bi, and, where appropriate, (D) a specified amount of Cr and Pd. This composition is applied to ceramic surface followed by calcining at 600-800 deg.C to form a noble metal film on the ceramic.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of a liquid or paste noble metal composition for painting used in ceramics, and more specifically, a liquid or paste liquid noble metal composition adjusted to improve alkali resistance. The present invention relates to improvement of a precious metal composition for painting.

[0002]

2. Description of the Related Art Conventionally, Rh (rhodium) has been used as a main ingredient as a sintering inhibitor for liquid or pasty precious metal compositions for painting, which are used for ceramics including ceramics and glassware. By adding and blending Cr, Bi, V, B and the like to the above, a beautiful noble metal mirror surface is fired on the ceramic surface, and the alkali resistance of this fired noble metal thin film is improved.

[0003]

However, since the above rhodium has a small amount of resources and is in high demand, the price has risen remarkably. Therefore, rhodium is used as a sintering inhibitor for precious metal compositions for painting. It has become extremely difficult to do.

Further, when rhodium is used, the alkali resistance of the mirror surface of the noble metal applied to the surface of the ceramic is not sufficiently satisfactory. For example, noble metal compositions for painting with rhodium having the composition shown in Table 13 are used. The precious metal film formed by 100% in a 2% aqueous solution of sodium carbonate
When a boiling alkali resistance test at ℃ was performed, it should take about 10 minutes at a calcination temperature of 600 ℃, about 50 minutes at a calcination temperature of 700 ℃, and about 80 minutes at a calcination temperature of 800 ℃. It was found that the gold mirror surface was completely peeled off. That is, rhodium, which has been conventionally used as a sintering inhibitor for precious metal compositions for overpainting, has a serious problem that the price is very high, and also has a problem that alkali resistance is not always sufficient. ..

The present invention was researched and developed with the object of solving the above problems, and the inventors of the present invention have conducted various experiments and researches, and as a result, have sintered a precious metal composition for painting. As an inhibitor, it is possible to exert a sintering prevention effect comparable to rhodium as compared with rhodium, which is significantly cheaper and more easily available than conventionally used rhodium, and has an alkali resistance of a noble metal film formed by the composition. The present invention has been completed by discovering a surprising fact that can significantly improve

The main object of the present invention is to improve the alkali resistance of the noble metal thin film fired on the surface of the ceramic remarkably and to maintain a beautiful noble metal mirror surface for a long period of time. An object of the present invention is to provide a paste-like precious metal composition for overpainting. Another object of the present invention is to provide a liquid or paste form for use in ceramics, which is capable of significantly improving the sintering preventing effect of the precious metal thin film that is fired on the surface of the ceramic, and is capable of reliably firing a beautiful precious metal mirror surface. Another object of the present invention is to provide a precious metal composition for painting. Still another object of the present invention is to provide a precious metal composition for overpainting which is provided with each of the above-mentioned excellent features at a significantly low cost and easily.

[0007]

As a means for solving the above-mentioned problems and achieving the object, in the present invention, gold, platinum,
To the resinate solution or resinate paste of palladium or other noble metal, the required amount of resinate solution or resinate paste of thorium as a sintering inhibitor and alkali resistance improver, an adhesive such as bismuth, and an appropriate amount of rosin and solvent are added, and further necessary. A noble metal composition for liquid painting or paste coating for ceramics, which is characterized by adding chrome and a small amount of rhodium according to the above, was developed and adopted.

Further, in the present invention, in the above liquid or paste noble metal composition for painting, the noble metal 100
Liquid or paste noble metal composition for overcoating used in ceramics, characterized by adding 1 to 8 parts by weight of thorium to parts by weight, and noble metal 10
1 to 8 parts by weight of thorium, 1 to 10 parts by weight of bismuth, and 0.02 to 3 parts by weight of rhodium are added to 0 parts by weight, respectively, to prepare a liquid or paste for use in ceramics. We have developed and adopted the precious metal compositions for painting on the shape of each.

[0009]

EXAMPLES In order to facilitate understanding of the present invention,
A description will be given with some examples.

Example 1 Table 1 shows an example of the composition of a gold liquid for liquid painting (Liquid Bright Gold) having a gold content of 11% and containing thorium as a sintering inhibitor. Table 2 shows the metal composition of the gold thin film after coating and firing in the case of ceramics at 600 ° C to 800 ° C.

[0011]

[Table 1]

[0012]

[Table 2]

A uniform bright gold thin film without sintering having a metal composition in the ratios shown in Table 2 was subjected to a boiling alkali resistance test at 100 ° C. in a 2% aqueous solution of sodium carbonate, and found to have a firing temperature of 600 ° C. The gold thin film was not peeled at all even after boiling for about 15 minutes, about 2 hours at 700 ° C., and about 5 hours at 800 ° C., and the original beautiful gold mirror surface could be retained.

Example 2 A compositional example of a gold liquid for liquid painting (Liquid Bright Gold) having a gold content of 11%, in which an appropriate amount of Rh was used in combination with Th as a sintering inhibitor, is shown in Table 3, and this 11% Table 4 shows the metal composition of the gold thin film after the gold liquid was applied to the ceramic surface and fired at 700 ° C to 800 ° C in the case of a ceramic.

[0015]

[Table 3]

[0016]

[Table 4]

A uniform bright gold thin film without sintering having a metal composition in the ratio shown in Table 4 was subjected to a boiling alkali resistance test under the same conditions as in Example 1, and the baking temperature was 70.
Even if it was boiled at 0 ° C. for about 2 hours and at 800 ° C. for about 5 hours, the gold thin film was not peeled at all, and the original beautiful gold mirror surface could be retained.

Example 3 Table 5 shows an example of the composition of a palladium liquid for painting with thorium as a sintering inhibitor, and a palladium liquid added to a gold liquid having a gold content of 11%. Table 6 shows the metal composition of the palladium thin film after coating on the ceramic surface and firing at 800 ° C. in the case of ceramics.

[0019]

[Table 5]

[0020]

[Table 6]

A palladium thin film of sinter-free bright having a metal composition of the ratio shown in Table 6 was subjected to a boiling alkali resistance test under the same conditions as in Example 1, and the firing temperature was 8
Even if it was boiled for about 4 hours at 00 ° C., the palladium thin film was not peeled at all, and the original beautiful gold mirror surface could be retained.

Example 4 A composition example of a platinum liquid for overpainting in which a palladium liquid and a platinum liquid were added to a gold liquid having a gold content of 11%, in which an appropriate amount of Rh was used in combination with Th as a sintering inhibitor, is shown in Table 7. Table 8 shows the metal composition of the platinum thin film after the platinum solution was applied to the ceramic surface and fired at 800 ° C. in the case of ceramics.

[0023]

[Table 7]

[0024]

[Table 8]

Pt resinate has a strong catalytic property at 300 ° C.
When heated above the above, spontaneous ignition will occur. Usually, an organic sulfur compound is used as a catalyst poison, or a low-grade composition is prepared.
Almost no difference was found in the alkali resistance test between Th and Th. However, when a plurality of noble metal compositions as shown in Table 7 above were used, it was found that Th in combination with Rh is effective not only as a sintering inhibitor but also as an alkali resistance agent. That is, when a uniform platinum film without sintering having a metal composition of the ratio shown in Table 8 was subjected to a boiling alkali resistance test under the same conditions as in Example 1, it was boiled for about 3 hours at a firing temperature of 800 ° C. Even though the platinum thin film did not peel off, the original beautiful platinum mirror surface could be retained, and it was proved that the result was superior to the comparative example described below in which only Rh was used as the sintering inhibitor. ..

Example 5 A composition example of a matting gold liquid for overpainting in which gold powder was added to a gold liquid having a gold content of 11% using thorium as a sintering inhibitor is shown in Table 9.
Table 10 shows the metal composition of the matte gold thin film after the matte gold solution was applied to the ceramic surface and fired at 700 ° C to 800 ° C in the case of ceramics.

[0027]

[Table 9]

[0028]

[Table 10]

When a non-sintered matte gold thin film having a metal composition of the ratio shown in Table 10 was subjected to a boiling alkali resistance test under the same conditions as in Example 1, it was about 2 when the baking temperature was 700 ° C. In the case of 800 ° C. for about 5 hours, the matte gold thin film was not peeled at all even after boiling for about 5 hours, and the original beautiful matte gold mirror surface could be retained.

Example 6 An example of a composition of paste gold for overcoating in which thorium is used as a sintering inhibitor and a gold content of 11% is shown in Table 11, and the paste gold is used for screen printing on a ceramic surface. Table 12 shows the metal composition of the gold thin film after being applied and fired at 600 ° C to 800 ° C in the case of ceramics.

[0031]

[Table 11]

[0032]

[Table 12]

A uniform bright gold thin film without sintering having a metal composition in the ratios shown in Table 12 was subjected to a boiling alkali resistance test under the same conditions as in Example 1, and the same results as in Example 1 were obtained. was gotten. Note: (1) Numerical values of the metals shown in each of the above examples are not metal oxides but all metal contents. (2) The thorium used in each of the above examples refers to all organic thorium compounds that have a ThO ₂ structure when fired in air.

In the present invention, the addition amount of thorium is set to a ratio of 1 to 8 parts by weight with respect to 100 parts by weight of noble metal, because when the addition amount of thorium is less than 1 part by weight, the surface of ceramics is fired. This is based on the reason that sintering of the noble metal thin film cannot be sufficiently prevented and the alkali resistance of the noble metal thin film is deteriorated. Further, when the addition amount of thorium exceeds 8 parts by weight, the coloring degree of the noble metal is increased. Is not possible to form a beautiful precious metal mirror surface, and the adhesion color of the precious metal thin film is reduced. Further, the addition of Cr is not an essential requirement of the present invention, but the addition amount is 0.1 to 100 parts of noble metal.
A range of 1.5 parts is desirable.

[0035]

COMPARATIVE EXAMPLE Next, a comparative example will be described in which rhodium is conventionally used instead of thorium used as the sintering inhibitor and the alkali resistance improver in each of the above-mentioned examples.

Comparative Example 1 Table 13 shows an example of the composition of a gold liquid for liquid painting (Liquid Bright Gold) having a gold content of 11% and containing rhodium as a sintering inhibitor. Table 14 shows the metal composition of the gold thin film after coating and firing at 600 ° C. to 800 ° C. in the case of ceramics.

[0037]

[Table 13]

[0038]

[Table 14]

A non-sintering uniform bright gold thin film having a metal composition in the ratios shown in Table 14 was subjected to a boiling alkali resistance test at 100 ° C. in a 2% aqueous solution of sodium carbonate.
The gold thin film was completely peeled off by boiling for about 10 minutes at a firing temperature of 600 ° C., for about 50 minutes at 700 ° C., and for about 1 hour and 20 minutes at 800 ° C.

Comparative Example 2 Table 15 shows an example of the composition of a palladium liquid for overpainting in which a palladium liquid was added to a gold liquid having a gold content of 11% using rhodium as a sintering inhibitor. Table 16 shows the metal composition of the palladium thin film after coating on the ceramic surface and firing at 800 ° C. in the case of ceramics.

[0041]

[Table 15]

[0042]

[Table 16]

When a sintered palladium thin film having a metal composition having a ratio shown in Table 16 and not sintered was subjected to a boiling alkali resistance test under the same conditions as in Comparative Example 1, it was about 1 at a firing temperature of 800 ° C. The palladium thin film was completely peeled off by boiling for a while.

Comparative Example 3 An example of the composition of a platinum liquid for overcoating, in which a palladium liquid and a platinum liquid were added to a gold liquid having a gold content of 11% using rhodium as a sintering inhibitor, is shown in Table 17. Table 18 shows the metal composition of the platinum thin film after the platinum solution was applied to the ceramic surface and fired at 800 ° C. in the case of ceramics.

[0045]

[Table 17]

[0046]

[Table 18]

A non-sintered platinum film having a metal composition of the ratios shown in Table 18 was subjected to a boiling alkali resistance test under the same conditions as in Comparative Example 1, and it was found that the baking temperature was 800 ° C. for about 1 hour. The platinum film was completely peeled off by boiling.

Comparative Example 4 A composition example of a matting gold liquid for overpainting in which gold powder was added to a gold liquid containing 11% of gold, using rhodium as a sintering inhibitor, is shown in Table 1.
Table 9 shows the metal composition of the matte gold thin film after coating the ceramic surface with this matt gold solution and firing it at 700 ° C to 800 ° C in the case of ceramics.

[0049]

[Table 19]

[0050]

[Table 20]

A non-sintered matte gold thin film having a metal composition having a ratio shown in Table 20 was subjected to a boiling alkali resistance test under the same conditions as in Comparative Example 1, and when the baking temperature was 700 ° C., it was about 50. The matte gold thin film was completely peeled off by boiling for about 1 hour and 20 minutes at 800 ° C. for one minute.

Comparative Example 5 An example of a composition of paste gold for overpainting with a gold content of 11% using rhodium as a sintering inhibitor is shown in Table 21, and the paste gold was used for screen printing on a ceramic surface. Table 22 shows the metal composition of the gold thin film after being applied and fired at 600 ° C to 800 ° C in the case of ceramics.

[0053]

[Table 21]

[0054]

[Table 22]

When a uniform bright gold thin film without sintering having a metal composition of the ratio shown in Table 22 was subjected to a boiling alkali resistance test under the same conditions as in Comparative Example 1, the same bad results as in Comparative Example 1 were obtained. Results were obtained.

As is clear from the description of each of the above Examples and Comparative Examples, the liquid or paste noble metal composition for overcoating used in the ceramics according to the present invention is a noble metal thin film which is fired on the ceramic surface. As a sintering inhibitor, without using rhodium alone as in the past,
Compared to the case where rhodium is used alone, thorium, which is much richer in resources and much cheaper than rhodium, is used alone or in combination with a small amount of rhodium.
Even if it is superior, it is possible to exert the same effect of preventing sintering.

Further, as compared with the case where rhodium is used alone, the alkali resistance of the noble metal thin film coated and fired on the ceramic surface can be remarkably improved, and the beautiful noble metal mirror surface can be retained for a long time even under severe use conditions. It is possible to obtain a great effect.

Although the details of the present invention have been described above with reference to the main embodiments, the above-mentioned embodiments are merely for the purpose of illustration, and the present invention is not limited to these embodiments. Without departing from the scope of the present invention, all should be included in the scope of the present invention.

[0059]

OPERATIONS AND EFFECTS OF THE INVENTION As is clear from the above description, the composition according to the present invention can exert the following various effects.

(1) As a sintering inhibitor for a noble metal thin film to be fired on the surface of ceramics, thorium is used alone or in combination with a small amount of rhodium, without conventionally using rhodium alone. As a result, compared with the case where rhodium is used alone, the effect of preventing sintering can be significantly improved, and a beautiful noble metal mirror surface made of a noble metal thin film can be formed on the surface of ceramics.

(2) Further, this composition can remarkably improve the alkali resistance of the noble metal thin film applied to the surface of the ceramic and baked, and can keep a beautiful noble metal mirror surface for a long time even under severe use conditions.

(3) This composition has an economic advantage that it can be provided at a significantly low cost because thorium, which is a sintering inhibitor, is more easily available than rhodium and the cost is significantly lower.

Claims (3)

[Claims] 1. A resinate solution or resinate paste of gold, platinum, palladium or other noble metal, a resinous solution of thorium in the required amount as a sintering inhibitor and an alkali resistance improver, an adhesive agent such as resinate paste and bismuth, and an appropriate amount thereof. A noble metal composition for liquid painting or paste-like use for ceramics, which is prepared by adding rosin, a solvent and, if necessary, chrome and a small amount of rhodium. 2. A liquid or paste noble metal composition for overcoating used in ceramics according to claim 1, wherein 1 to 8 parts by weight of thorium is added to 100 parts by weight of the noble metal. object. 3. 100 parts by weight of noble metal, 1 to 8 parts by weight of thorium, 1 to 10 parts by weight of bismuth and 0.02
The liquid or paste noble metal composition for overcoating used in the ceramics according to claim 1, which is prepared by adding 3 to 3 parts by weight of rhodium.