JPH06234548A - Japanese-style coloring material for pottery - Google Patents

Abstract

PURPOSE:To obtain an over-glaze coloring free from the generation of intrusion or stripping and sufficiently adaptable for the regulation standard of eluting lead test. CONSTITUTION:A coloring agent made of an adequate quantity of transition metal oxides is incorporated into a glass composition containing, by wt.%, 48.0-52.0% SiO2, 2.5-5.5 Al2O3, 20.0-30.0 B2O3, 8-20% total sum of PbO, BaO and ZnO and 5-7% total sum of Na2O, K2 and Li2O. For instance, at the time of baking at baking temp. of 830-860 deg.C, the thermal expansion coefficient is 5.1 to 5.3X10<-6>, the result of eluting lead test is 0.8-1.6mug/cm<2> and transparency, brightness and coloring are excellent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Japanese paint for porcelain which is completely fused to porcelain glaze without penetration and is excellent in acid resistance, transparency and color development.

[0002]

2. Description of the Related Art Paints used for overpainting on ceramics include Western paints and Japanese paints, both of which are fused to the glaze on the side to be painted by firing.

[0003] Western paints generally have a colorant suspended in glass and are totally opaque, whereas Japanese paints are transparent because the colorant is dissolved in the glass. It has excellent properties and has a good gloss. On the other hand, Japanese paint is often painted by putting the paint thickly, so if there is a large difference in the coefficient of thermal expansion between the top paint and the glaze on the side to be painted, cool it after baking with paint. In the process of, distortion may occur between the upper paint and the glaze, the upper paint may penetrate, or the upper paint may peel off.

According to the traditional oral tradition, the traditional Japanese paint for ceramics has a frit of 50% called a leaded white ball (weight percentage, hereinafter the same), 30% of tangible earth, 10% of silica stone, and an appropriate amount. It was usually adjusted by incorporating a colorant.

[0005]

According to the prior art, since the chemical composition of the frit, the components of the colorant, and the amount of the frit are determined solely by the experience and intuition of the formulator, they are necessary for the production of tableware. It has various characteristics, that is, it does not cause harmful penetration or peeling, it develops color well, it has excellent transparency and gloss, and it has acid resistance that sufficiently complies with the regulation standards for eluted lead in the Food Sanitation Law. However, there is a problem that it is extremely difficult to prepare the composition.

Therefore, an object of the present invention is to properly define the chemical composition of a glass composition so that all characteristics including compliance with the regulation standard of eluted lead can be obtained without causing penetration or peeling at all. It is to provide extremely good Japanese paint for ceramics.

[0007]

The constitution of the present invention for attaining the above object is, in terms of weight percentage, SiO ₂ 48.
_{0~52.0%, Al 2 O 3 2.5~5.5} %, B 2 O
_{3 20.0~30.0%,} PbO, BaO, the total content 8-20% of _{ZnO, Na 2 O, K 2} O, Li 2 O total content 5 of
The gist of the invention is to add a colorant composed of a transition metal oxide to a glass composition composed of 7%.

As the coloring agent, the glass composition 10
0%, CuO 4.0-6.0% and F ₂ O ₃ 0-0.5%, CoO 1.0-2.0% and Cu by weight percentage.
_{O1.0~1.6%, Fe 2 O 3 0.5~1.5} %, M
It can be either nO ₂ 1.8 to 2.5% or CoO 0 to 0.5%.

[0009]

According to the structure of the invention, SiO ₂ , B
₂ O ₃ is generally a glass-forming component, but SiO 2
₂ tends to raise the melting temperature and B ₂ O ₃ tends to lower it. Further, SiO ₂ is effective in reducing the coefficient of thermal expansion. Therefore, it is preferable to increase the amount of SiO ₂ as much as possible, but if the total amount of alkali metal oxides is 7% or less and the SiO ₂ exceeds 52%, the melting temperature will exceed 900 ° C. Get scarce.
On the other hand, if it is less than 48%, the acid resistance is deteriorated, and excessive Pb, Na, K and the like may be eluted in the eluted lead test according to the Food Sanitation Law. When B ₂ O ₃ exceeds 30%, the acid resistance becomes extremely poor, while when it is less than 20%, the melting temperature becomes excessive.

Since Al ₂ O ₃ significantly raises the melting temperature, it should be contained in a small amount as much as possible, but if it is less than 2.5%, phase separation occurs, the acid resistance is significantly deteriorated, and the transparency is high. Be damaged. Further, if it exceeds 5.5%, the melting temperature becomes excessive.

On the other hand, considering that the coefficient of thermal expansion of the white base material is about 4.5 to 5.6 × 10 ⁻⁶ , the coefficient of thermal expansion of the upper paint is about 5.0-
It is preferably in the range of about 5.5 × 10 ⁻⁶ . In general, alkali metal oxides of Na ₂ O, K ₂ O, and Li ₂ O are effective in lowering the melting temperature, but at the same time, they tend to significantly increase the coefficient of thermal expansion, so their total amount is , 7% or less is required. In particular, Li ₂ O
Is preferably 1% or less, and a minute amount of 1% or less of Li ₂ O is effective in decreasing the melting temperature. Further, when K ₂ O exceeds 5%, the melting temperature tends to increase, but with respect to the purple colorant MnO ₂ , it improves the color developability, so it is recommended to increase it slightly. To be When the total amount of alkali metal oxides is less than 5%,
The melting temperature becomes too high, which is not practical.

PbO, BaO and ZnO also increase the coefficient of thermal expansion, but their effect is not as great as that of alkali metal oxides. The influence on the coefficient of thermal expansion is
Since O is most prominent, it is necessary to control BaO to 5% or less at the maximum and to use it together with PbO or ZnO. PbO acts as a glass-forming component when it is contained in a large amount, but when it is too large, the acid resistance deteriorates and the coefficient of thermal expansion also becomes excessive. Therefore, it is preferably suppressed to 13% or less. Z
nO has the least effect on the coefficient of thermal expansion. However, since it does not have the effect of lowering the melting temperature as much as PbO,
It is preferable that the maximum is 10% or less. Also, PbO, B
If the total amount of aO and ZnO is less than 8%, the melting temperature will be excessive, and if it exceeds 20%, the thermal expansion coefficient will be excessive and the acid resistance will also deteriorate.

The glass composition has a painting temperature of about 830 to 860 ° C. when used as an overcoat. Further, it has an appropriate coefficient of thermal expansion, and even if it is thickly laid on a white base material having the smallest coefficient of thermal expansion, it does not cause penetration or peeling at all, and has sufficient transparency and beautiful luster. In addition, it has good acid resistance and can sufficiently meet the regulation criteria of the dissolved lead test according to the Food Sanitation Law.

CuO and Fe ₂ O ₃ as colorants develop a green color. However, if CuO is less than 4.0%,
The color is light, and if it exceeds 6.0%, the color tone becomes darker and
The melting is incomplete and the transparency is impaired. F of 0.5% or less
e ₂ O ₃ is effective in adding a yellow color to the green color to develop a stable green color, but if it exceeds 0.5%, the yellow color becomes too strong and is rather harmful.

CoO is the main coloring agent of dark blue,
If it is less than 1.0%, the color is light, and if it exceeds 2.0%, the color becomes too dark and blackish. The addition of CuO is effective for the stability of color development, but if it is less than 1.0%, it has no effect.
If it exceeds 1.6%, the effect of the green color is excessive and the color tone is impaired.

Fe ₂ O ₃ develops yellow color, but
If it is less than 5%, the color tone is light, and if it exceeds 1.5%, it becomes reddish brown. Further, excessive Fe ₂ O ₃ impairs transparency and raises the melting temperature.

MnO ₂ produces a purple color. 1.8%
If it is less than 2, the color is light, and if it exceeds 2.5%, the color becomes too dark and the melting temperature becomes high. A trace amount of CoO of 0.5% or less is effective in stabilizing the purple color by adding dark blue.

Such a Japanese paint for ceramics can be manufactured as a so-called color frit. That is, raw material chemicals are prepared so as to obtain a predetermined chemical composition containing a colorant, and the mixture is melted at about 1300 ° C. for 1 to 2 hours. The viscous melt is poured into cold water to quench it,
After sufficiently drying, a color frit is obtained by finely pulverizing to an average particle size of about 25 μm. The color frit can be drawn with a brush and overpainted by mixing water and furi and dissolving it to an appropriate viscosity.

[0019]

As described above, according to the present invention, by properly defining the chemical composition of the glass composition, various characteristics including the melting temperature, the thermal expansion coefficient, and the acid resistance can be expressed in a well-balanced manner. Therefore, even with a white base material with the smallest coefficient of thermal expansion, there is no risk of penetration or peeling, acid resistance is good, and it is fully compatible with the regulatory standards for eluted lead and is transparent. It has the excellent effect of excellent properties, color development and gloss.

[0020]

Example 1 32.12 parts silicon dioxide, kaolin 9.
22 parts, borax 13.44 parts, boric acid 27.49 parts, red lead 7.46 parts, potassium carbonate 3.20 parts, lithium carbonate 1.80 parts, basic copper carbonate 5.06 parts, red pattern 0 0.22 parts were blended and the mixture was melted at 1300 ° C. for 1.5 hours, poured into cold water and quenched. After being sufficiently dried, it was dry-ground for 17 hours by an alumina pot mill to obtain a color frit.

The chemical composition of the color frit is SiO ₂ 5
0.0%, Al ₂ O ₃ 5.0%, B ₂ O ₃ 28.0%,
PbO 10.0%, Na ₂ O 3.0%, K ₂ O3.0
%, Li ₂ O 1.0%, 100% of the glass composition, CuO 5.0%, Fe ₂ O ₃ 0.
It contained 3%.

When the obtained color frit was dissolved in water and furi, it was easy to draw and no harmful sagging occurred. 830-
When baked at 860 ° C., a green color excellent in transparency and gloss was developed, and no penetration or peeling occurred even for a white base glaze having a thermal expansion coefficient of 4.32 × 10 ⁻⁶ .

The coefficient of thermal expansion of this product is 5.16.
× is 10 ^-6, dissolution of lead test results based on the Food Sanitation Law, with respect to regulatory standards value 17μg / cm ^2, 0.8μg /
It was cm ² .

[0024]

Example 2 33.31 parts of silicon dioxide, kaolin 9.
56 parts, 18.58 parts of borax, 22.81 parts of boric acid, 10.50 parts of red lead, 2.21 parts of potassium carbonate, 1.36 parts of cobalt oxide, 1.68 parts of basic copper carbonate, By performing the same processing as in Example 1, a color frit was obtained.

The chemical composition of the color frit is SiO ₂ 5
0.0%, Al ₂ O ₃ 5.0%, B ₂ O ₃ 26.0%,
PbO 13.0%, Na ₂ O 4.0%, K ₂ O 2.0%
CoO 1.8 with respect to 100% of the glass composition consisting of
%, CuO 1.6%.

This product developed a deep blue color, and its characteristics were very good, as in Example 1. The coefficient of thermal expansion of this product was 5.30 × 10 ⁻⁶ , and the eluted lead test result was 1.3 μg / cm ² .

[0027]

Example 3 35.51 parts of silicon dioxide, kaolin 5.
81 parts, borax 14.11 parts, boric acid 28.85 parts, red lead 7.96 parts, zinc white 3.06 parts, potassium carbonate 2.2.
4 parts, lithium carbonate 1.89 parts, and red pattern 0.57 parts were mixed and treated in the same manner as in Example 1 to obtain a color frit.

The chemical composition of the color frit is SiO ₂ 5
0.0%, Al ₂ O ₃ 3.0%, B ₂ O ₃ 28.0%,
PbO 9.0%, ZnO 4.0%, Na ₂ O 3.0%,
K ₂ O2.0%, relative to the glass composition to 100% consisting of Li ₂ O1.0%, and contained Fe ₂ O ₃ 0.75%.

This product developed a yellow color and its properties were also very good. The coefficient of thermal expansion is 5.10 × 1.
0 ⁻⁶ , the elution lead test result was 1.6 μg / cm ² .

[0030]

Example 4 33.21 parts of silicon dioxide, kaolin 9.
53 parts, borax 6.95 parts, boric acid 32.93 parts, red lead 7.85 parts, barium carbonate 0.97 parts, potassium carbonate 4.97 parts, lithium carbonate 1.86 parts, manganese dioxide 1.51. Parts and 0.23 parts of cobalt oxide were mixed and treated in the same manner as in Example 1 to obtain a color frit.

The chemical composition of the color frit is SiO ₂ 5
0.0%, Al ₂ O ₃ 5.0%, B ₂ O ₃ 28.0%,
PbO 9.0%, BaO 1.0%, Na ₂ O 1.5%,
2.0% of MnO ₂ and 0.3% of CoO with respect to 100% of a glass composition consisting of 4.5% of K ₂ O and 1.0% of Li ₂ O.
Was included.

This product developed a purple color and its properties were also very good, the coefficient of thermal expansion was 5.20 × 10 ^-6 , and the result of the eluted lead test was 1.3 μg / cm ² .

[0033]

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] February 12, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

As the coloring agent, the glass composition 10
0% to CuO 4.0 to 6.0%, Fe ₂ O ₃ 0 to 0.5%, CoO 1.0 to 2.0% and C by weight percentage.
uO 1.0 to 1.6%, Fe ₂ O ₃ 0.5 to 1.5%,
Either MnO ₂ 1.8 to 2.5% or CoO 0 to 0.5% can be used.

Claims (5)

[Claims] 1. SiO ₂ 48.0-5 by weight percentage.
2.0%, Al ₂ O ₃ 2.5 to 5.5%, B ₂ O ₃ 2
0.0-30.0%, PbO, BaO, ZnO total amount 8
_{~20%, Na 2 O, K} 2 O, Li 2 O in the total amount 5-7%
A Japanese color paint for ceramics, which comprises a glass composition containing a colorant containing a transition metal oxide. 2. The colorant is the glass composition 100.
%, CuO 4.0-6.0%, F by weight percentage
e ₂ O ₃ 0 to 0.5%.
Japanese paint for ceramics described. 3. The glass composition 100 is used as the colorant.
%, CoO 1.0-2.0%, C by weight percentage
uO of 1.0 to 1.6%.
Japanese paint for ceramics described. 4. The glass composition 100 is used as the colorant.
%, By weight percentage, Fe ₂ O ₃ 0.5 to 1.5%
The Japanese color paint for ceramics according to claim 1, wherein 5. The glass composition 100 as the colorant.
% By weight, MnO ₂ 1.8-2.5%,
CoO is 0 to 0.5%, and the Japanese paint for ceramics according to claim 1.