CS221007B1 - Frit for the preparation of basic enamel for dry application in an electrostatic field - Google Patents

Abstract

The frit according to the invention, in addition to the requirement to exclude barium, an element harmful to health, solves a) the problem of further increasing the quality of the coating, which is achieved by reducing the sodium oxide content.

Description

The invention relates to a frit for the preparation of dry-base enamel in an electrostatic field, suitable in particular for a method of applying single-firing base and top enamel. Known frits of this kind according to the prior art contain in most cases cobalt oxide as a holding agent. Their disadvantage is the relatively high cost and general nedosjtatok cobalt oxide. Also known are cobalt-free frits, whose advantage over cobalt frits is the reduced raw material cost achieved by cobalt savings. A disadvantage of one of the frits, however, is that it contains barium oxide, which is harmful to health. Another frit powder has the disadvantage that it is relatively sensitive to increased relative air humidity, resulting in fluctuations in the electrostatic adhesion of the powder.

These drawbacks are eliminated by the frit for the preparation of the base enamel of the invention, which consists in that the frit contains 30 to 46% silica, 16 to 24% boron oxides, 5 to 15.99% sodium oxide, 0.2 to 4% oxide potassium, 1 to 5% of the lithium oxide, 4 to 8% of the calcium oxide, 1 to 5% of clay, 0.5 to 2% of phosphorus pentoxide, 0.5 to 2% of titanium dioxide, 1.5 to 4 % of nickel oxide, 0.7 to 3% of manganese dioxide, and 4 to 8% of calcium fluoride.

The advantage of the frit according to the invention, while being cobalt-free and free of any barium compound as a particularly harmful element, is that the powder prepared therefrom can be applied over a wide range of thicknesses without the risk of ejection in the coating. thicker deposits, especially at the edges, resist to a higher degree of exposure to higher relative humidity, which guarantees stable electrostatic adhesion. The powder can also be operated over a wider range of granulometric compositions.

The following is an example of a frit composition according to the invention, the components of which are expressed in weight concentration:

Silicon dioxide

Boric oxide

Sodium oxide

Potassium oxide

Lithium oxide

Calcium oxide

Aluminum oxide

Phosphorus pentoxide

Titanium dioxide

Nickel oxide

Manganese dioxide

Calcium fluoride

The method of applying a frit according to the invention is similar to that of a known frit of this kind. The overall appearance of the finished enamel formed from the frit of the present invention is homogeneous, without igneous

S1O2 .... 43 B2O3 .... 18 Na2O .... 12 K2O .... 1.25 L12O .... 4 CaO. . . . 6 AI2O3. . . 2 P2O5 .... 1.2 T1O2 .... 1.2 NiO .... 3.2 Mn02. . . 0.8 CaF2 .... 7.35

even when the thickness of the deposition is three times four times the prescribed thickness. This feature of the frit according to the invention is a prerequisite for its wide range of applications.

Claims (1)

PREDMET Frit for the preparation of basic enamels for dry deposition in an electrostatic field, characterized in that it contains silica at a concentration of 30 to 46 percent, boron oxide at a concentration of 16 to 24%, sodium oxide at a concentration of 5 to 15.99% , potassium oxide at a concentration of 0.2 to 4%, lithium oxide at a concentration of 1 to 5%, calcium oxide at a concentration of 4 to 8%, alumina at a concentration of 1 to 5%, phosphorus pentoxide at a concentration of 0% , 5 to 2%, titanium dioxide at a concentration of 0.5 to 2%, nickel oxide at a concentration of 1.5 to 4%, manganese dioxide at a concentration of 0.7 to 3%, and calcium fluoride at a concentration of 4 to 8 θ / o.