JPS6037065B2 - Enamel low alkaline frit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Today, in the enamel industry, there is an urgent need to save energy, save resources, and further reduce costs by rationalizing the enamel manufacturing process.

One way to streamline the enamel manufacturing process is to improve the pongee laying method. Currently, there are two methods of enameling that are already in practical use in Japan: the pongee pongee pongee pongee pongee pongee pongee pongee pongee pongee method that utilizes the dew-air migration phenomenon, and the dry powder electrostatic pongee pongee pongee pongee pongee pongee pongee pongee pongee pongee method that utilizes the phenomenon of dew electrophoresis, which saves resources and energy and produces high-quality enamel. It is attracting attention as it can be manufactured at low cost. In particular, in the dry powder static lightning pongee method, -60 to 19
By applying an electrostatic voltage of 0 KV between the item and the gun, the frit particles are charged and pongee is made efficiently. On the other hand, the frit particles that are not effectively used for pongee making are continuously collected and used again. This method has the great advantage that there is no waste of frit.

In this case, the effectiveness of the dry powder static casting method depends on how efficiently the frit particles are charged and how long the charged frit particles maintain their charge level. In order to maintain charging efficiency and charge amount, it is better for frit particles to have a larger electrical resistance value. In general, the frit normally used in the enamel industry is made of 760% enamel, which is mainly applied to metal materials such as iron or its alloys.
Since glass is fused onto a metal material by firing for a relatively short time of 2 to iQ minutes at a temperature of ~880 qo, its composition is limited.

In order for the enamel to have the various properties substantially required under the above-mentioned firing conditions, the frit composition should be SiO
It is necessary that the total amount of monovalent alkali metal oxides be in the range of 235 to 55 M%, &0310 to 2 skin t%, and 10 to 25 M%. It can be said that the electrical properties of a frit are controlled by the amount of monovalent alkali component in the frit composition. It is known that the electrical resistance of frit particles decreases as the temperature increases due to the movement of monovalent alkaline components in the frit. Therefore, by reducing the amount of monovalent alkali metal oxide, the electrical properties of the frit and, of course, of the enamel are improved. However, among the frits currently used in the enamel industry, low-alkali frits are used for heat-resistant enamel for stainless steel, but these frits contain less &03 components,
The characteristic is that there are many muscle 0 components, or the Si02 component is 65
It is characterized in that B203 is M% or more and breast Wt% or less, and the firing temperature is usually 950 to 1050°C. In the ceramics industry, many frits with low monovalent alkali content are used, but many of these frits usually contain harmful PbO components, and frits that do not contain POO have a low flow rate at the firing temperature. It is impossible to convert it to enamel due to problems with its properties and coefficient of thermal expansion.
In view of these current circumstances, the inventors conducted various studies on frits that can be fired satisfactorily within the conventional firing conditions for enamel and have excellent electrical characteristics, and as a result they have completed the present invention.

That is, the first aspect of the present invention is Si0230~5 skin t%, &0
320-35M%, the total amount of one or more of Na20, K20, Li20 is 0.1-4.0wt%, Ca0
, mother ○, total amount of one or more of Zn0, Mg○, Sr○ is 20 to 4 t%, Tio, 2, 1 of Zr02
The total amount of the species or two species is 0-1%, AI203 is 0-1%.
The second invention is a low alkali frit characterized in that the oxidation rate is 3%, and the second invention is characterized in that Moo3 is essential for the 10% oxide, and this and Ni○, Coo, M
The total amount of one or more of n○ and Cb○ is 0.05~
This is an enamel low alkali frit characterized by a 5M% content.

Next, the reasons for the limitations of the present invention will be described.

The reason why Si02 is 30-5% is because Si02 is 3%.
If it is less than %, it is difficult to substantially vitrify it, or
This is because even if it is vitrified, it cannot be put to practical use because it lacks chemical resistance, and if Si02 exceeds 5 skin t%, the firing temperature increases and at the same time the coefficient of thermal expansion decreases. The reason why the content is set at 20 to 35 M% is that if it is less than 2.9%, the firing temperature will not be sufficiently low, and if it exceeds 35 wt%, the coefficient of thermal expansion will become too small. Na20, K2
0, the amount of monovalent alkali metal oxide such as Li20 is 0.1
~4. The skin t% was defined as 4. This is because if it exceeds skin t%, sufficient electrical properties, especially a large electrical resistance value, cannot be obtained (approximately 0.1 wt% exists as impurities).
This point is an important feature of the present invention. Also Ca○, Ba○
, Zn0, Mg0, and S, the total amount of one or more of them is set to 20 to 4 t% because if it is less than 2 t%, the firing temperature cannot be lowered sufficiently, and it exceeds 4 t%. This is because vitrification becomes virtually impossible. At this time, Ti02
When the total amount of one or both of Zr02 and Zr02 is added at 1% or less, the chemical resistance of the glass improves, and when Zr03 is added at 3wt% or less, the chemical resistance of the glass is improved.
When added below, it has the effect of improving the chemical resistance of glass.

Furthermore, with respect to 10% of the above-mentioned oxide, Moo3
is essential, and when one or more of Ni○, Coo, Mn○, and Cu○ are added in a total amount of 0.05 to 5wt%, the former has the effect of lowering the surface tension, and the latter has the effect of lowering the surface tension of the material. The low alkali frit of the present invention is extremely effective when used as a dressing because it has the effect of promoting close adhesion to the material.

Next, the present invention will be explained by citing specific examples.

Example 1 Table 1 Oxide composition of frit Na2○ 3. skin t
%&03 29.0
〃Si02
35.0〃Ca0
20.0〃B60
9.0〃Zn0
4.0 total
100.0 Table 2 Preparation composition of frit Anhydrous trellis sand 97 parts trellis acid 397 Katsura stone
・ 350〃Calcium carbonate 116〃Barium carbonate
116 Zinc white
40 total
1357 Each raw material was prepared according to the formulation shown in Table 2 that satisfied the oxide composition shown in Table 1, mixed well, melted at a temperature of 1250 to 1280 qC, and rapidly cooled to obtain a frit.

The obtained frit was dry-milled to leave a 200-mesh streak of about 5#, and an electrostatic charge of -9 V was applied to a steel plate with a base plate baked using an electrostatic powder gun. ,
It adhered relatively well, and even when it was placed in a furnace for firing, no adhering powder was observed to fall.

Example 2 Table 3 Oxide composition of frit Li20 2.
5wt%B03 3
3.5〃Si02
31.0〃Ti02
4.0〃Zr02
5.0〃Ca0
16.0〃Mg0
4.0 Total 100.0 Table 4
Lithium carbonate 62 parts Acid 596 Katsura acid
285 Titanium oxide
40 Zircon Cinate
75 Calcium carbonate
286 Magnesium carbonate
84″ total
1428〃Tani raw materials were prepared according to the formulation composition in Table 4 that satisfies the oxide composition shown in Table 3, mixed well, melted at a temperature of 1300 qo, and rapidly cooled to obtain a frit. Weight of the obtained frit 10 4 parts by weight of clay,
0.1 part by weight of sodium aluminate, C.I. M. C.O. 0.5 parts by weight of bentonite, 0.2 parts by weight of bentonite, and 50 parts by weight of water were milled to obtain a slip with a roughness of enough to pass almost all the way through a 200-mesh node. They used it to make pongee.

The applied membrane was very strong, and the current used was very low, so that the temperature rise of the slip due to Joule heat was significantly reduced and the throwing power of the slip was improved. After drying, it was baked for 2.5 minutes at 830:00, and a beautiful surface was obtained, and the edges were well covered with glaze. Example 3 Table 5 Oxide composition of frit Li02 0.
5wt%Na20
0.5″&03
31.0〃Si02
35.0〃Ti02
7.0〃Zr02
2.0″Ca0
15.0〃Ba0
7.0〃N2
03 2.0〃Total 100.0〃Mo
o3 3.0
〃Coo 0.
3〃Ni0
0.7〃Mn0
1.5 total
2.8 Table 6 Preparation composition of frit Lithium carbonate 12 parts Soda ash 9 Shelves Acid
552 Acid
340 Titanium oxide
70 Zircon acetate
30 Calcium carbonate
268 Barium carbonate
90〃Alumina
20 total 13
91〃Molybdenum oxide 3〃
Cobalt oxide 3 Nickel oxide 7 Manganese oxide
15〃Total
1419 According to the formulation composition shown in Table 6 that satisfies the oxide silk composition shown in Table 5, each raw material was prepared, mixed well, and then melted at a temperature of 1330 to 135000 to obtain a rapidly cooled frit.

2 parts by weight of clay, 0.5 parts by weight of pentonite, C.I. M. C.O. Add 0.5 parts by weight and 1 part by weight of Chin powder kaiseki to a 325 mesh knot with 55 parts by weight of water to dry residue after drying for about 3 to 4 days (slip collection amount 10
0') to obtain a slip.

Spray the resulting slip with a spray gun for 6 minutes (wet)
When both sides were sewn at a ratio of /10 x 15 on one side and fired at 870°C for 3 minutes, an enamel with a very smooth surface was obtained.

When the surface of the enamel was observed using an optical microscope, it was found that the air bubbles were very small. When the electrical resistance of the surface of this enamel was measured, it was found to be very high, about 1.30 m, which was significantly improved compared to the surface electrical resistance of ordinary enamel. As is clear from the above examples, reducing the monovalent alkali metal oxide in the frit composition significantly improves the electrical properties of the frit, and in the future electrical components will require insulation resistance at high temperatures. The present invention has great industrial significance as it can be applied to

Claims (1)

[Claims] 1 SiO_2 30-50 wt% B_2O_3 20-35 wt% Total amount of one or more of Na_2O, K_2O, Li_2O 0.1-4.0 wt% CaO, BaO, ZnO
, MgO, and SrO, the total amount of one or more types 20~
An enameled low-alkali frit characterized in that the total amount of one or both of TiO_2 and ZrO_2 is 0 to 10 wt%, 0 to 3 wt%. 2SiO_2 30-50wt% B_2O_3 20-30wt% Total amount of one or more of Na_2O, K_2O, Li_2O 0.1-40wt% CaO, BaO, ZnO,
Total amount of one or more of MgO and SrO 20-4
0 wt% Total amount of one or both of TiO_2 and ZrO_2 0 to 10 wt% Al_2O_3 0 to 3 wt% of the oxide composition of 100 wt%, MoO_3 in the outer layer
is essential, and this and NiO, CoO, MnO, CuO
An enamel low-alkali lift characterized by containing one or more of the following in a total amount of 0.05 to 5 wt%.