Healthy Home Decoration, Start from Understanding Inorganic Coatings

There is no clear definition of inorganic coatings so far, and the naming of coatings is generally determined by the main film-forming substances, so inorganic coatings usually refer to a class of coatings with inorganic materials as the main film-forming substances or binders. There are many kinds of inorganic binders, and inorganic coatings can be applied in different fields according to the performance characteristics of inorganic binders. Such as phosphate as inorganic binder inorganic coatings as industrial high-temperature coatings, based on silane curing silica sol inorganic coatings (also called inorganic ceramic coatings) often as a non-stick coating and industrial high decorative baked ceramic coatings.

Common inorganic binders in the construction industry are mainly cement, gypsum, alkali metal silicates (water glass), silica sol, lime, etc.. Cement and gypsum can only be used to manufacture dry inorganic coatings, lime can be used to produce both dry inorganic coatings and liquid inorganic coatings, and water glass and silica sol can only be used to produce liquid inorganic coatings. Dry powder inorganic coating is generally only suitable for thick film coating, thin surface coating will be less effective, and dry powder inorganic coating construction is not convenient. The most used inorganic coatings in the construction industry are liquid inorganic coatings, and the main binders of liquid inorganic coatings are lime, water glass and silica sol. Lime-based inorganic coatings have been seldom used due to the disadvantages of strong alkalinity, slow drying, inability to adjust the color (only white), and poor weather resistance. Therefore, the current architectural liquid inorganic coatings mainly refer to the inorganic coatings based on water glass and silica sol.

Development history of inorganic coatings

The first generation of inorganic coatings invented by Kem more than 140 years ago was pure inorganic coatings, which were two-component coatings (also known as 2K coatings) consisting of powders composed of inorganic pigments and fillers and liquid potassium silicate. According to the German standard DIN 18363, it is formulated as a two-component, completely free of inorganic components and can only be used to coat surfaces of solid, absorbent mineral-based substrates. Its excellent weathering resistance and color fastness are unmatched, and buildings decorated with inorganic paints in the 19th century are still intact today. The first generation of inorganic paints is still in use today, but has the disadvantage of being packaged in two-component packages, which must be thoroughly mixed before use and require a certain amount of time to mature.

In 1962, the second generation of inorganic coatings came out, it is potassium silicate as the main binder, supplemented by a small amount of highly alkali resistant organic synthetic emulsion, and add the appropriate amount of inorganic pigments, fillers and additives formulated as a one-component silicate emulsion coatings, also known as organosilicate coatings. According to the German standard DIN18363, the organic component (including emulsion and additives) should not exceed 5%. Thanks to the second generation of inorganic coatings, inorganic coatings in the form of silicate emulsion coatings have been highly sought after by consumers since the 1970s and have been developed worldwide, especially in Europe. 2002 saw a revolution in the exterior coatings market thanks to the third generation of inorganic coatings: "silica-sol silicate coatings" based on the concept of a completely new binder were introduced as a new category of inorganic coating, "silica-sol silicate coatings". Coatings", based on a new binder concept, opened up completely new fields of application for inorganic coatings. The new base material is a stable mixture of silica sol and potassium water glass which, in addition to the chemical bonding with the inorganic mineral substrate through silicification, produces a strong adhesion to solid organic coatings and, due to the lower curing shrinkage stress, is less susceptible to skinning and cracking and can therefore be applied to almost any common substrate surface. It can also be used on almost any common substrate surface because it dries faster, has better water resistance, and has less salt precipitation, making it more suitable for exterior wall coating. The organic content of silica-sol silicate coatings is still kept below 5% and therefore still meets the requirements of DIN 18363.