Paint has many purposes. From protecting the structure of a building to being an important design method in architecture. This is because the colour of a paint underlines the individual character of a building, a street, an ensemble or an entire location. So colour design is anything but trivial or arbitrary.
Paint also changes in colour: wood goes dark or grey, white coats of paint become yellow and facades fade. The latter can be avoided: with mineral external paints and their highly lightfast inorganic pigments. The paint remains unchanged for decades!
Many paints change, some quicker than others – this is due to pollution, harmful substances (so-called "acid rain") and, in particular, the levels of UV in sunlight. Whilst dirt diminishes the brilliance of a paint's colour, UV light can lead to a change in the paint itself. The binder in conventional paints breaks down, as seen particularly in a white fogging effect on brightly coloured paint coatings. Dirt on the paint naturally changes the visual appearance.
The phenomenon of paints changing colour has been known for decades and is an obvious visual flaw on buildings for all to see. You are sure to be familiar with the typical so-called "shutter effect" – the facade has faded, whilst the original colour of the exterior paint remains essentially unchanged behind the shutters, protected from light and the weather. These and many other manifestations related to colour changes have a considerably detrimental effect on the overall impression of a facade. They are not only unattractive but also counteract every intended colour design.
We differentiate between organic and inorganic (mineral) pigments. UV light causes a change in the chemical structure of organic pigments and in their colour. This does not apply to mineral pigments. They are made from natural raw materials such as iron oxides and stand out with an extremely high colour shade constancy. They are durable, lightfast and UV-resistant, and retain their colour for decades. Even "acid rain" cannot harm them. Colour-fast coatings – silicate exterior paints –consist of only selected mineral pigments.
The binder has a considerable influence on the colour of a paint. Organic binders such as those used in conventional paints are made from synthetic materials. They change over time and become milky. Microscopic cracks can form. The colour of the paint becomes greyer and less pure.
Silicate paints by KEIM are made with only inorganic binders such as potassium silicate or sol-silicate. They allow light rays to hit the colour pigment unhindered and permanently. The binder enables the coating to form a permanent bond with the substrate, based on the silicification principle. Spalling of the paint is not possible. Nor do mineral paints attract dirt particles in the same way as conventional paints.
KEIM mineral paints contain only top quality inorganic pigments. This consistent approach is unique in the paint market and ensures long lasting coatings!
Mineral paints by KEIM therefore remain unchanged for decades, ensuring brilliant facades with lasting colour stability. Some exterior coatings with KEIM paints are over 100 years old!