DD216477A1 - POLISHING MIXTURE FOR GLASS OBJECTS - Google Patents

Abstract

The invention relates to a polish mixture for Glasgegenstaende, especially for screen parts of Bildwiedergaberoehren. The aim is to limit the consumption of polishes with low availability. The object is the development of a polish mixture, in the use of the solid content in the polishing suspension is not subject to settling in the circulating containers. The polish mixture according to the invention is characterized in that it consists of amorphous hydrated silicic acid and cerium oxide with other rare earths in an aqueous slurry and the particle size of the hydrated silicic acid is 2 ... 60 μm. The proportion of silica to cerium oxide and other rare earths is preferably 50%.

Description

Inventor:

W dr. Badger, Robert Naundorf, Hans-Jürgen Bräuer, Axel Pluta, Kurt Peschke, Werner Jakob, Angela

Authorized agent ι

VEB Kombinat Technical Glass Ilmenau

Central Office for Property Rights GDR - 6300 - ILMENAU PO Box 303

IPK: 0 09 G, 1/02

Polish mixture for glass objects

Field of application of the invention;

The invention relates to a polishing agent mixture for glass objects, in particular for screen parts of video display tubes.

• 1 SEI? 1983)

Characteristics of the known solutions ^

For polishing glass articles, a number of polishes such as iron oxide, alumina, titania, zirconia, zinc oxide, ceria and the like, which are normally used in the form of an aqueous slurry, are known.

Among the plurality of polishing agents, cerium oxide predominantly used in admixture with other rare earths such as lanthana, jteodymia, praseodymia and the like has the greatest polishing efficiency.

Characteristic of the cerium oxide is the high specific glass removal achieved during the polishing process and the gloss polishing produced,

The use of cerium oxide in admixture with other rare earths is therefore predominantly used in high-performance polishing machines, where the production of a gloss polish at a short machine cycle time, such as, for example, is difficult. when polishing picture tubes for picture tubes, it is demanded "The low availability and high price of ceria limit its use as a polish.

The use of cerium oxide with other rare earths in aqueous slurry is carried out for rational utilization on the polishing machines in the Breislauf. A waxy part is the settling of the polishing agent into the collecting, Ruhr, sieve and storage containers, which is still intensified by the glass abrasion constantly present in the polishing suspension Polishing agent not evenly secured for the effective polishing process and therefore also the degree of polishing of the polishing agent is limited «

DB - AS 1271288 proposes the use of silica sol as a stable colloidal material for polishing materials

Dispersion of amorphous silica is characterized in a liquid.

The use of silica sol as a single component to polish glass articles does not assure the required polishing effect, as is the case with the use of cerium oxide with other Pail rare earths.

Another Kachteil is the lack of gloss polishing, so that the application for the intended purpose on high-performance polishing machines, especially for polishing screens for picture tubes is not possible for both reasons.

In DE - AS 1239044 a Glaspoliermittelmischung is proposed, which goes beyond the additive polishing effect of individual cheap polishes «For this purpose, a mechanical mixture of finely divided silica with a finely divided monoxide of the group zinc, cadmium and lead oxide. As can be seen from the examples presented there, the polishing effects achieved with the proposed polish mixtures are not sufficient for the polish performance * achieved with the use of sole cerium oxide, since the polish time of the compositions is in all cases lower than that with the use of cerium oxide single component. The use of this mixture for high-performance polishing machines, in particular for polishing screen parts for picture tubes, therefore excludes for this reason.

Object of the invention:

The aim of the invention is the development of a polish mixture for glass objects, in particular for screen parts of picture tubes, the application of which ensures a high polishing effect and at the same time limits the consumption of polishes with low availability and high price.

Essence of

The invention has for its object to develop a polish mixture, "in its use, the solids content in the polishing suspension is not subject to settling in the circulating containers and at the same time a constant constant distribution of the polishing agent in the suspension and thus its optimal recovery in the polishing process is guaranteed.

According to the invention this object is achieved in that polish mixture is used in which the Zeroxtd used in a known manner with other rare earths in aqueous slurry by amorphous hydrated silica having a Teilchengrb'ße of 2 ,,. 60 which is distinguished by a high absorption capacity, net, partially replaced.

The polish mixture according to the invention in aqueous slurry has thixotropic properties and the solids content in the suspension has a high specific surface area. As a result, a uniform distribution of effective for the PoIierprozeß individual polishing agent components is achieved and prevents their settling during the cycle on the polishing machines. When using the polish mixture according to the invention for glass articles, especially for screens for picture tubes on Hochleistungspoliermaschinen with short cycle times, in addition to a high polishing performance is achieved a reduction in the specific material consumption of limited available and expensive Zeroxides with other rare earth Des ^ further the polish mixture according to the invention characterized that the proportion of hydrated silica in relation to ZeroxLd and other rare earths is 5 * _ββ 95 % _9, preferably 50% _g

Total rare earth oxide to at least 50 % and the total solids content of polishes in the polishing agent suspension 10 ... 80 g / l, preferably 60 g / l. /,.

Embodiment of the invention:

The invention will be explained in more detail below using an exemplary embodiment:

Purely by polishing screen parts for display tubes, the polish mixture is prepared by mixing 3 kg of hydrated silicic acid and 3 kg of rare earths containing 52 % CeO 3 in a container and the contents to a volume of 100 l with water is replenished.

The solids content of the polishing agents in the polishing agent suspension is 60 g / l.

The particle size of the hydrated silicic acid is, according to the sludge analysis using ultrafine particles:

Total residue on 50, ^ m sieve: 10,6 % total residue on 30 / in sieve: 25,5 % total residue on 15 / tm sieve: 45,8 %

After stirring, the boll compound mixture is ready for use and is fed to the circuit on the high-performance polishing machines for carrying out the polishing process.

Claims (1)

Erfindungsanspruoh; A polish mixture for glass articles, in particular for picture screen parts of picture display tubes, characterized in that it consists of amorphous hydrated silicic acid and cerium oxide with other rare particles of an aqueous slurry and the particle [. / size of the hydrated silica is 2 to 60 mm thick. f ~ 2. Poliermittelgeinisch according to item 1, characterized in that the proportion of hydrated silica in relation to cerium oxide and rare earth changed Ms 5 95% - preferably 50% _t, is ·        \. '.' - ·. <. 3 · polish mixture according to items 1 and 2, characterized in that the proportion of ZeroxLd to the rare earths is at least 50 % in total, 4 · polish mixture according to item 1 to 3, characterized in that the total amount of polish in the polish suspension is up to 80 g / l, preferably 60 g / l.