DE94853C - - Google Patents

Description

IMPERIAL

PATENT OFFICE.

J '

The pigments that these types of painting have hitherto used, those on the open air ensuing solidification of a binder containing the pigments and mixed with them are based - that is, binder painting in contrast to ceramic painting - suffer without exception to the great disadvantage, especially the pigment, the color body itself, is a more or less easily decomposable substance, which by its very nature is relatively weak chemical effects are destroyed or their color can be influenced can.

For example, if you bring creamy white, a frequently used body of color, into contact with hydrogen sulphide it is blackened, zinc white is thinned by the action Sulfuric acid destroyed, cinnabar turned gray in the open air in a short time.

Even mixing individual colors with each other brings with it dangers, as one mutual decomposition can take place; for example, when mixing Cremserweifs with cadmium yellow lead sulfur, which makes the mixture very bright soon cloudy.

Also the binders with which and the substrates on which the pigments are applied can have a very harmful effect on them.

When painting "al fresco" ζ. B. the color scale is extremely limited, since the Lime used as a substrate and binding agent destroyed many of the otherwise common colors.

When processing with other binders, other inconveniences arise. In the application dry oil z. B. 100 parts of creamy white absorb only 17 parts of oil, 100 parts madder, on the other hand, 250 parts oil. The first color dries very quickly, the second very quickly slowly, and this gives so different drying properties when mixing, painting over each other, etc. Body easily giving rise to cracks, folds, darkening, etc. All of the above Evils now, which have become a real calamity in our painting today can be remedied by adding colored, finely ground glass flows of certain composition can be used.

If the basic mass of these rivers has a sufficiently high content of silica, so can be seen as almost insensitive to chemical reagents (with the exception of hydrofluoric acid) and be called absolutely durable and weatherproof. They influence each other not in the least, are completely indifferent to all binding agents, such as oil, lime, Water glass, casein, tempera, and always have binding agents when rubbed with equal parts same consistency.

There is no longer any restriction of the color scale in one or the other technique necessary and one is no longer interested in certain chemical compounds which are accidental produce a usable color (cream white = basic lead carbonate, Cinnabar = sulfur-mercury, ocher =

Iron oxide hydrate, Schweinfurt green = arsenic acetic acid Copper oxide), but can, since nowadays the coloring of glass rivers is developing to a high degree of perfection has to make any color you want.

It is true that there has been a single color in binder painting since the earliest times in use, soft, at least earlier, in most cases from a finely ground one Glass rivers existed, namely the cobalt color or real smalts. But it was next to the other perishable pigments are not used because of their greater durability, but for the sake of the beautiful color which is unique to cobalt silicates and could not be replaced by any other chemical compound.

But since the experience was made at the beginning of this century that Thon was involved When annealed, cobalt compounds take on almost the same color as the real smalt these have been consistently replaced by the new, less durable preparation.

Smalt has also remained the only pigment which has been produced in the form of a colored glass, unconscious of its special durability and without this special property having given rise in the course of time to differently colored pigments with the same property.

As already indicated, the basic mass of the glass flow, which is actually used for production Unassailable, weatherproof paints should be used, a high silica content have e.g. B.

ιooSilicic acid, 5 carbonate of potash, 8 carbonate of lime for those glasses in which with Consideration of the .Metal oxide to be melted down for coloring, an addition of lead is avoided must be, or

60 silica, 30 lead oxide, 10 borax for metal oxides which can tolerate the addition of lead.

The silica content is 60 pCt in both cases. and above. It sinks significantly below this level, the resulting glass loses its durability considerably. So insist for example the colored glass frits, which ceramic painting uses, approximate from 75 lead oxide, 25 silica, or 10 lead oxide, 60 borax, 30 silica. Diluted Hydrochloric acid destroys almost all of them.

The frits are only received when they are melted onto the relevant substrate used brands have sufficient firmness, shine and their correct color and persist mostly only from mixtures of rivers and metal oxides and unmelted frits, which in many cases have a significantly different color than in the fully melted state.

Also with regard to the addition of coloring metal oxides, the glass fluxes, which are intended to be used for the production of durable paints, are significantly different from others. Since even very intentionally colored glasses look very pale when powdered and coated with a binding agent, those glasses must have a very high content of coloring oxides in order to obtain a colored powder of sufficient intensity after the melt product has been ground.

. Even very. deeply colored., glasses for colored glass windows contain a maximum of 3 pCt. coloring Oxide, the deepest porcelain colors up to 20 pCt., The glasses for paints, however, up to 50 pCt.

Claims (1)

Patent Claim:,.
Process for the production of durable, weatherproof paints, characterized in that glass fluxes with a high content of silicic acid and paint are finely rubbed and, instead of the pigments customary up to now, with the binders peculiar to the individual types of paint (linseed oil, casein, lime, rubber, etc.) to paintable paints are processed.