JPS60118649A - Low-melting enamel glaze - Google Patents

Abstract

PURPOSE:A low-melting enamel glaze composition that is obtained by adding a specific amount of Mn oxide to a low-melting enamel fritt containing MoO3, thus being sintered below A1 transformation temperature to form enamel layers of high adhesion and smoothness. CONSTITUTION:To 100pts.wt. of a low-melting enamel fritt composition containing SiO2, B2O3, Na2O, F2, K2O, Li2O, CaO, BaO, Al2O3, ZrO2 and more than 1% of MoO3, is added more than 0.5pts.wt. of Mn oxide such as MnO2. The resultant enamel glaze composition can be sintered at a temperature lower than A1 transformation temperature of steel and further form enamel layers of high adhesion and smooth surfaces even in steel plates undergoing low-grade pretreatment.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an enamel glaze composition that can be fired at low temperatures.

Conventional structure and its problems Generally, the baking mA degree of enameled steel plate is 800 to 870°.
C, which is higher than the mountain transformation point of steel, so it is easily deformed due to thermal distortion during baking, resulting in poor dimensional accuracy after baking and a high defect rate.Therefore, it is necessary to increase the plate thickness. Also, steel plate 2so
When heated at a high temperature of ○ to 870"C, hydrogen gas adsorbed or occluded in the steel sheet will be significantly generated, and the moisture in the slip and the moisture on the steel sheet will combine with carbon in the steel sheet in the firing temperature range. The reaction generated carbon dioxide gas, which tended to cause defects such as bubbles and bottle balls on the enamel surface.

For example, the thickness of the inner wall of an oven. , When enamel is baked on a 6 MN□ steel plate at 800 to 870°C,
There were disadvantages such as large deformation of the molded product, occurrence of many bubbles, bubbles, etc., and a high defect rate. On the other hand, if enamel can be fired at a low temperature below the A1 transformation, there will be less deformation due to thermal distortion, and as a result, there will be fewer defects such as bubbles and pinholes due to gas generation, and it will be possible to fire enamel at a low temperature below the A1 transformation. It has the advantage that it is easy to use, and it is easy to enamel VC products with complicated shapes.

In recent years, saving resources and energy has become an important issue, and by lowering the firing temperature of enamel, it is possible to reduce the cost of piercing, and by making it possible to use thin sheets, the material of the base material can be reduced. Therefore, the inventors of the present invention have proposed the following eight characteristics of steel: It can be baked below the transformation point, it can be deglazed, it has excellent slip shelf life, and it can be used for low-grade steel sheets. We have developed a low softening point transparent enamel frit that has better adhesion than enamel even after pretreatment. The basic composition of the frit was as follows.

510232-45% by weight A22030.5-5B
2037-20n ZrO20,5-4,5rrNa
20314-22 F2 2-9 2004-
5 u MoO30,4-5rtL 1200,3-2
〃 CoO15-15n BaO1,5-1 s u Usually, Co is used as a frit for lowering general enamel.
Although O is widely known to be effective as an adhesive oxide, C00 is expensive, so it is often not used in combination with NiO or U MnQ2.

Regarding low-melting enamel fired at low temperatures, COO was not as effective as it is said to be for general enamel. In low-melting enamel, M
oO3 worked effectively as an adhesion improver and the Mo5s
i stands for friso) Since it is not colored, it was possible to obtain a transparent enamel friso.

The figure shows the relationship between the firing temperature and adhesion of enamel when Frit'Th containing 2% by weight of each of Mo5s (represented by the solid line) and C00 (represented by the dotted line) is used. Adhesion is the adhesion rate of PEI standard.

The base material is a 5 pcc steel plate with a thickness of 0, 6 parts Mtb, a pickling loss of about 10 owI/dm2, and a nickel coating amount of about ahy.
/cbf.

The firing time was kept at each set temperature for 5 minutes, and the enamel film thickness was about 120 Jim.

Could be approx. 780 approx. I think it's due to sublimation in the vicinity.

However, when using Furinotowo1 history including MoOs,
Although excellent adhesion was obtained even when fired at low temperatures, it was found that there was a problem in that larger bubbles were generated in the hollow, making the surface uneven.

This phenomenon was noticeable in frits with a special V (Mo0) of 31% by weight or more (hereinafter simply expressed as %).

Purpose of the Invention The present invention provides a low-melting enamel glaze composition that can be fired below the A1 transformation point of steel, has excellent adhesion even when the steel plate is pretreated with a low grade, and can obtain a single layer of enamel with a smooth surface. 0 Structure of the Invention The low melting enamel glaze composition of the present invention has Mo0a f1%
Low softening point enamel frit f main component containing the above,
A porcelain glaze composition that can be fired at 750°C or lower, containing 0.5 parts by weight or more of manganese oxide per 10 parts by weight of hollow frit. With V, large bubbles no longer occur and a smooth surface is obtained.

The amount of manganese oxide added to the mill should be increased in proportion to the amount of MoO3 in the hollow frit composition; if the amount is 1% in the frit, add 0.5 part of K in the mill, and if it is 5%, add 3 ~6 sites are sufficient, and as a manganese oxide, MnQ M
There are n3O4, MrI203 and Mr102, but 1VirIO2 is generally used.

Description of Examples The glaze composition of the present invention can be produced, for example, as follows. That is, first, a low softening point enamel film having a composition containing Mo53f is prepared.

For this purpose, the following raw materials for each component are mixed according to the composition ratio. Thoroughly dry mixed raw materials are 1100-1300
Melt by heating at °C. In this case, it is necessary to carefully control the heating temperature and time by changing the composition ratio of the final frit components. ' Also time -: 2 after dissolving the raw material
It is important to allow vitrification to proceed for 40 minutes and stir as necessary.

If the glass is kept in a molten state for a long time, the alkaline components will sublimate and break off, so in order to avoid this for too long, after melting, the glass is placed in water to be rapidly cooled and heated at rt4. - When dried, a low softening point enamel frit is obtained.

Examples of raw materials for each component 1) S102 component sandstone, feldspar 2) S203 component fluorite, sorg fluoride, potassium borofluoride, barium fluoride, cryolite.

4) Na2O components: soda ash, soda saltpeter, sulfur salt, borax, silicofluoride soda,
Cryolite, feldspar 0 5) K20 ingredients potassium saltpeter, potassium carbonate, potassium borofluoride, feldspar.

6) L12o component Lithium carbonate, spodumene.

7) CaO component Limestone, slaked lime, fluorite, dolomite.

8) Ba○ components barium carbonate, barium nitrate, barium fluoride 09) A
IV, 203, Z r02 components alumina, alumina hydroxide, cryolite, feldspar.

ZrO2, di)l/ :I7, (ZrO2-ns 1
02) 01o) M003 Components MoO2, ammonium molybutate, molybutylene/acid 1. IJum, molybdenum disulfide, molybdenum disulfide 'n,7'i obtained as above: low softening point enameled furino l-, usual slip agent (e.g. clay, silica powder, coloital silicate, sodium nitrite) , pigment, water)
In addition to Mo0a f for foam suppression, milling was carried out using a ball mill to obtain a glaze composition that was rubbed onto a water-based slip. , 600 to 750''C, it becomes an enamel film with a smooth surface.

1 Table 1 V The raw materials shown in Table 1 were blended in the proportions shown in the same table to make low softening point frit formulations 1 to 4').

Compounds 1 to 4 were thoroughly dry-mixed and dissolved at 1200°C, and then maintained at the same temperature for 30 minutes. After melting, the glass was put into water and rapidly cooled, and then dried and smoked to obtain Friso IG-1 to G-4 having the compositions shown in Table 2.

Table 1 (unit: double placement part) Table 2 (unit: weight %) Next, 5 parts of clay was added to 100 parts each of the four types of low softening point enamel frits G-1 to G-4 obtained as described above. 1 part, 2 parts of silica powder (325 mesh under), 0.0 parts of sodium nitrite.
1 part, a pigment containing MnO2° or manganese oxide in the amount shown in Table 3, and water were added, and the mixture was milled in a wet ball mill to form a slip.

Milling is carried out for about 3 hours, and the particle size suitable for spray glazing (
200 Menonyu residue of 60CC slip) 3-6,9
The slip was adjusted to r and specific gravity of 1.75 to 1.85.

100 rub x 1 with pre-treated slip
00×0.6M 5pCC steel plate (pickling reduction value approx. 50n)
vld, nickel adhesion amount approx. 2 yn/dyn'
) was spray glazed. After that, it is dried, 690-72
Baked at 0°C for 5 minutes to obtain a single layer of hollow surface, P,
The n adhesion rates were determined using E and I adhesion testers, respectively.

Note that the enamel film thickness was set to about 120 μm.

The method for determining adhesion using the P, E, and I adhesion testers is to press a fired test piece to 2000 bonds (approximately 907
．． A force of 20/ ) was applied, continuity was detected using 169 needles, and the adhesion rate was determined using the following formula.

Adhesion rate (to) = ((169 - number of detections) / 169)
As shown in Table 3 of Xl 00 Table 3, when MoO3 in the frit is less than 1%, no abnormal generation of bubbles is observed, but the adhesion performance is insufficient. On the other hand, M003 is 1%
In the above case, sufficient adhesion performance was obtained, but bubbles were generated and the appearance was poor, but this bubble did not occur when fired at a high temperature. For example, if the slip of Comparative Example 3 is glazed and fired at 750°C for 5 minutes, no bubbles will be generated, but because the firing temperature is too high, the enamel layer will have a yuzu skin, burnt edges, or flakes. However, it was not practical.

Therefore, even if the frit contains 1% or more of MoO3, if 0.5 parts by weight or more of manganese oxide is added to the mill, the firing conditions of 690 to 1°720"C23 can be improved.
Even after ~4 minutes, the abnormal generation of bubbles disappeared and a good surface condition was obtained. Examples 1 to 3 are examples in which Mn02f was used as the manganese oxide. It is also possible to use pigments containing crushed manganese oxides. Example 4 has MnO of 20~
CuO-MnO-Coo-Cr203 containing 30%
- This is an example using a Fe203-Nio-based black pigment.

Mill addition of manganese oxide also improves the adhesion rate.

Since manganese oxide colors the enamel layer reddish-purple, brown, or black, the enamel layer using the low-melting enamel glaze composition of this example will have a dark color such as black thread, braided thread, or gray. ing.

Effects of the Invention As described above, the low-melting enamel glaze composition to which manganese oxide is added can be fired at a temperature below the A1 transformation point, resulting in less deformation and strength deterioration, less pinholes and flaking, and It has many of the original characteristics of low-melting enamel, such as being resource-saving and energy-saving, and even when the steel plate is pretreated with a low grade, it has excellent adhesion and a smooth surface with a single layer of porosity. .

[Brief explanation of drawings]

The figure shows the adhesion in the frit as a relationship between the firing temperature of the enamel and the adhesion of the enamel for different oxides. Name of agent: Patent attorney Toshio Nakao (1) Written amendment (1986) Yudero Genzuki (1988) Patent Application No. 222607 (2) Name of the invention: Low-melting enamel glaze (3) Relationship with the case: Patent Application location 1006 Kadoma, Kadoma City, Osaka Prefecture Name (
582) Matsushita Electric Industrial Co., Ltd. Representative Toshihiko Yamashita 4 Agent 571 Address 1006 Oaza Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. Column 777 for the detailed description of the invention in the specification subject to the 5th amendment 6. Contents of amendment 0) rMos3J on page 8, line 11 of the specification will be corrected to "manganese oxide." (2) On page 11, lines 16-17, [200o pounds (
Approximately 907.20K9) force” r 2000psi
(Corrected to "D pressure".

Claims (1)

[Claims] A low-melting enamel glaze which has a low softening point enamel frit containing 1% by weight or more of Mo53f as a main component and contains 0.5 parts by weight or more of manganese oxide per 100 parts by weight of the enamel frit.