Silicate mineral paint

The term describes mineral colors paints with mineral binders. In the field of color are two relevant mineral binders: lime and silicate.

While lime binder under the influence of carbon dioxide and water carbonation ( carbonate ), bind silicate binder (usually potassium silicate or potassium silicate ) under the action of CO2 and form into contact with mineral reactants calcium silicate hydrates.

After lime coatings (subject to the fresco technique ) are only partially resistant to weathering, they find today focus only in the field of historic preservation application. If today is spoken of mineral colors, silicate paints are usually meant. It is here to paints that use potassium silicate as a binder. They are also called water glass colors or Keimfarben ( after the inventor Adolf Wilhelm Keim ).

The particular composition of silicate paints gives these special properties. Mineral - silicate paints are very durable and weather resistant. You can achieve a life of well over a hundred years. An example of this is the town hall provided in the 19th century with a mineral paint in Schwyz in Switzerland.

History

Alchemists in search of the " Philosopher's Stone " ( gold production ) discovered in fireplaces glassy shimmering beads. Sand mixed with potash and heat fused into water glass beads. First small round water glass discs were prepared and used as the first window. The first industrial production of water glass was made in the 19th century by Van Baerle in Gernsheim and Johann Gottfried Dingler in Augsburg. First experiments with water glass colors produce by Johann Nepomuk von Fuchs. In 1850 Munich's Pinakothek facade painting by the painter Kaulbach and Schlotthauer. By using not verkieselungsfähiger pigments ( earth pigments ) were washed out the paintings out of the water glass.

Mineral colors were patented in 1878 by craftsmen and researchers Adolf Wilhelm Keim and are still produced today by the successor company Keimfarben Diedorf at Augsburg.

V. Also van Baerle on which germ was instructed as a source for his glass of water, trying to make himself silicate paints. His experiments lasted for years, until they were mature, and he finally came to good results. The Silinwerk van Baerle in Gernsheim on the Rhine and the company Keimfarben Diedorf at Augsburg were known manufacturers.

Trigger for the intensive research Adolf Wilhelm seed was King Ludwig I of Bavaria. The art-loving monarch was so impressed by the colorful Kalkfresken northern Italy that he wanted to experience these works of art in his Kingdom of Bavaria. But the weather north of the Alps, known as much rougher, destroyed art paintings in a short time. Thus came his order to the Bavarian science to develop a color that looks like chalk, but is durable over a longer time.

Today, there are original paintings from the 19th century. Facades in Switzerland, for example, the inn " White Eagle " in Stein am Rhein or the town hall in Schwyz ( 1891), Oslo (1895 ) or in Traunstein (1891 ) are impressive evidence.

Properties

Mineral colors in addition inorganic colorants as the main constituent, a potassium- containing alkali silicate (water glass ), the potassium silicate, liquid potassium silicate, or even LIQVOR SILICIVM called. A paint with mineral colors not like other forms paints a layer, but combines permanently with the basic ( silicification ).

The result is an extremely stable connection between painting and painting carrier. In addition, the binder water glass is highly resistant to UV influences. While organic binders such as acrylate or silicone resin dispersions become brittle under UV influence over the years and to chalking, cracking, and in turn lead to paint damage, the inorganic binder glass of water remains stable. The chemical compound with the substrate and the UV stability of the binder are the main reasons for the extremely high durability of silicate paints.

To bind put silicate paints require a silicon-containing substrate. Therefore, they are suitable for mineral substrates such as mineral plasters and concrete. In wood and metal they are not or only partially usable. The water vapor permeability ( diffusion potential ) of silicate paints corresponds to that of the canvas. That is, silicate paints hinder the diffusion of water vapor is not practical. In the building or in the plaster contained moisture can freely diffuse to the outside again. This keeps the walls dry and avoid structural damage. In addition to condensate moisture is avoided at the building material surface. This reduces the risk of algae and fungi. The high alkalinity of the water glass binder provides additional security against attack by microorganisms and allows the complete abandonment of in-can preservatives.

Therefore, a contamination occurs less readily, because mineral painted surfaces other than dispersion or silicone resin -bonded paint surfaces recharge not static and heat are not sticky ( no thermal plasticity ). Therefore, stick to less dirt and they are also lighter washed off. Silicate paints are not inflammable, and do not contain organic ingredients and no organic solvents (DIN 18363 painting and decorating - Coatings 2.4.1).

Silicate paints are extremely color stable. After they are only tinted with mineral pigments and these are not changed by UV light in color, even the silicate coatings for decades in the shade remain constant.

Silicate paints are based on mineral raw materials. They are very environmentally friendly in production and effect. Your long life saves resources and the pollution- free formula protects the environment and health. Therefore Silicate colors are popular today, especially in the area of sustainable construction.

Types

Basically, today three types of silicate paints are distinguished: The pure silicate paint consists of two components, a dry or angeteigtem in water color powder and the liquid binder glass of water. (DIN 18363 painting and decorating - Coatings 2.4.1 ) The processing requires a lot of experience and know how. It is particularly common in the historic area.

Middle of the 20th century, the first one-component silicate paint was developed. The addition of up to 5 mass percent organic additives (eg acrylate, water repellents, thickeners, etc.) the color can be offered ready to use in the bucket. One speaks here of so-called " dispersion silicate paints " (DIN 18363 painting and decorating - Coatings 2.4.1). The scope of this silicate paint type is compared with the pure silicate paint significantly larger, because even substrates with lower strengths and / or organic components are coated. In addition, the processing is easier than in the pure silicate paint.

Since 2002 there is a third category of silicate paint, the so-called sol-silicate paint. It contains as binder a combination of silica sol and water glass. The organic content is limited as in the silicate emulsion paint on 5 percent by mass to obtain a chemical setting and the typical silicate strengths. The sol-silicate paint also allows for use on non-mineral plasters. Here the binding is chemically and physically. These colors are easy and safe to use on virtually all common substrates.