DE1249148B - Procedures for the production of underglaze decoration of porcelain, earthenware, majolica wares and the like - Google Patents

Description

UNION REPUBLIC OF GERMANY

IEUTSCHES

PATENT OFFICE

EDITORIAL

Int. Cl .:

C04b

German class: 80 b-23/02

Number: 1249148

File number: A 46572 VI b / 80 b

Filing date: July 13, 1964

Opened on August 31, 1967

In the production of underglaze decorations of porcelain, earthenware, majolica and the like as you know, proceed as follows:

The ceramic mass is slurried in water with the addition of fluxes and other admixtures and mixed thoroughly. This mass is then made on appropriate molding machines shaped.

After drying in the air, the ceramic blanks are smoothed, i. i.e., minor bugs and bumps are evened out. This is followed by a brief temperature drying in which the ceramic blanks can be dried leather-hard.

The ceramic blanks are decorated at this stage. For this purpose one uses Sliding decals in which the decoration is made with ceramic underglaze enamel paints on a special decal paper is printed. A suitable sliding varnish is printed on the image (decor) using mask printing.

After moistening the backing paper, the image is transferred to the ceramic blank. Since the ceramic If blanks are porous, the adhesive strength of the decals is not sufficient in most cases to ensure sufficient adhesion to the ceramic blank. For this This is usually based on the ceramic blank on which the decals are applied should apply a glue solution.

After the applied decal has dried, the ceramic blank must now be carefully placed in the Kiln so that the sliding varnish can burn. This process is particular in the Austrian patent specification 2-25 206 described.

After this intermediate firing, an aqueous glaze dispersion is applied to the decorated ceramic object sprayed on. This is followed by the glaze - Fer + igbrand. On the previous one Intermediate firing cannot be dispensed with in the previously common process, as the aqueous glaze dispersion does not adhere to the water-repellent sliding varnish, but rather runs apart on it. For this reason, attempts have also been made to add wetting agents to the sliding varnish, such as also the sliding varnish based on polymers containing carboxyl groups, which are water-swellable own to manufacture.

None of these attempts and methods are satisfactory, since the glaze continually rolls off is observed during the final firing, especially at the edges of the pictures.

Since the two-time burning process is due to loss of time

Method of making the
Underglaze decoration of porcelain,
Earthenware, majolica and the like

Applicant:

J. Albrecht, Mainz, Wallaustr. 33;

F. Xaver Leipold,

Zirndorf via Nuremberg, Österreicher Str. 20

Named as inventor:

Karl-Heinz Kluge, Mainz-Gonsenheim;

Alfred Eppich, Zirndorf

and material expenditure causes considerable costs, the task arose to reduce the underglaze de-

To simplify ao koration of said goods, to streamline the previous process and the application the decoration can still be improved. Since it was previously not possible to follow the decals the application to the leather-hard pre-fired ceramic blank with the aqueous glaze dispersion to overmold without doing an intermediate firing for the purpose of burning the sliding varnish, the following inventive method was developed.

After this, a frit is added to the previously known decal coating, which is is a defined melting glass glaze. The frit is used in the fineness of the enamel color to match the sliding varnish added in a suitable form by rolling in or stirring in, with, based on the remaining, dried film, about 50%, also more or less, can be added. The added frit is hydrophilic, so that a sliding varnish produced in this way can be compared with an aqueous varnish without any difficulty Can be sprayed over glaze dispersion without, as in the conventional way, prior to burning the sliding varnish would be necessary.

The incorporated frit is to be used in its melting start and in its melting interval upcoming glaze matched.

According to the method of the invention is in the

Production of underglaze decorated porcelain, earthenware, majolica goods and the like proceed as follows:

The ceramic mass is slurried in water with the addition of fluxes and other admixtures, mixed thoroughly and then shaped on appropriate molding machines.

709 639/492

After air drying, the ceramic Smoothed blanks, d. H. small errors and bumps are evened out. Then follows a short temperature drying in which the ceramic blanks are dried leather-hard.

The ceramic blanks can now be used in the places where they are to be decorated a fixative consisting of a solution of polyvinyl acetate in a combination of suitable solvents, be pretreated. The sliding image is now applied to the ceramic blanks, according to the invention the sliding varnish is mixed with frit, transferred.

Then the aqueous glaze dispersion is sprayed on without the intermediate firing that was previously necessary or applied in another of the known ways and after the glaze has dried ceramic bodies are fired in a fire at the usual firing temperatures.

This results in the essential advantage that the said porcelain, earthenware, majolica goods and the like can now be fired in one firing process in the underglaze decoration process. You can also proceed in such a way that the leather-hard, predried ceramic blank first coated with the aqueous glaze dispersion, after drying the areas to be decorated fixed with the already mentioned fixative and the underglaze sliding image produced using frit on the so fixed, unfired glaze. Now also in one Burning process Image and glaze burned.

In the German patent specification 209559 a process for the production of underglaze decals is disclosed protected, which is characterized in that the decal paper with a layer of chalk and a magnesia and glucose mixture is printed.

The technical application of this process fails because the printing technology on such treated papers is very difficult and that the dextrose mixture causes a strong sticking of the stored sheets with slightly increased humidity evokes.

The inventive method has the great advantage that the prints in the usual Way to be made on the normal decal paper and only in the decal film a frit is incorporated, which shows no sticking and which, due to its hydrophilicity, the later to be applied aqueous glaze dispersion assumes.

The frit contained according to the invention in the decal varnish also brings the new and special Advantage that an occasional rolling at the edges of the picture or a slight Er-S the fact that the image sintered into the glaze is reliably prevented by the frit above it will. In addition, the ceramic enamel color is counteracted by the frit above it mechanical stress and weak ίο acids protected.

Claims (3)

Patent claims: ]. Process for the production of the underglaze decoration of porcelain, earthenware, majolica goods and the like., Characterized in that a frit is added to the mask printing varnish (sliding varnish) required for the production of ceramic sliding pictures and the decor is in before applying the printed frit-containing sliding picture varnish its contours or also partially printed with a paint or printing oil that also contains fries, the frit contained therein being matched in its softening start and softening interval to the frit contained in the decal paint and to the ceramic enamel colors used to produce the decoration.
■ 2. The method according to claim 1, characterized in that the so-produced, provided with a frit-containing varnish sliding images on the with a fixative consisting of a solution of polyvinyl acetate in a combination of suitable solvents, fixed ceramic blank and then applied without intermediate firing with the aqueous glaze dispersion are coated. 3. The method according to claim 1, characterized in that the with a fry-containing Underglaze images provided with decal varnish on the unfired, with an aqueous glaze dispersion coated ceramic blank fixed with a fixative, be fired without intermediate firing in a fire at the usual firing temperatures. Considered publications:
German Patent No. 209 559;
German interpretative document No. 1 038 571;
Austrian patent specification No. 225 206. 709 639/492 8.67 © Bundesdruckerei Berlin