Silanes and Siliconates
Organofunctional silanes are compounds that combine the functionality of a reactive organic group with inorganic functionality in a single molecule. This special property allows them to be used as molecular bridges between organic polymers and inorganic materials. This bridging property of organofunctional silanes is crucially important in four application fields: in adhesion promotion, surface modification, crosslinking of polymers and in hydrophobization. Organofunctional silanes are available from WACKER with the trade names GENIOSIL®, SEMICOSIL® and SILRES® BS, and used in various applications due to their versatile properties.
Silicates are not silicones, since they are derived from oligo silicic acids. They differ by their content of residual alcohol groups. Further curing takes place by the addition of catalysts, such as sulfuric acid. Silicates include all salts and esters of silicic acid. Silicates are water-dilutable are are used in construction chemical applications and in coating systems. Silicates are marketed by WACKER for example under the trade name SILRES®.
Potassium methyl siliconate is present as a highly alkaline aqueous solution. Diluted with water, it is used for in-plant water-repellent impregnation of heavy clay products such as roof tiles, floor tiles and flower pots. After the water has evaporated, the potassium methyl siliconate reacts with atmospheric carbon dioxide (CO2) to form K2CO3 and the water-repellent active agent poly methyl silicic acid
As adhesion promoters, organofunctional silanes provide better anchorage of coatings, adhesives and sealants to a range of different substrates. In surface modification, they optimize compatibility and permit the chemical bonding of inorganic fillers to organic polymers. Organofunctional silanes are used as curing agents for organic polymers, for example in moisture-curing adhesives and sealants or paints and coatings. In addition, vinyl-functional silanes are used for crosslinking polyethylene, particularly for manufacturing heat-resistant pipes (for example, for drinking water pipes or underfloor heating) and as PVC substitutes for insulating cable sheathing.
For use as hydrophobic agents, for example for protection of construction materials, organofunctional silanes are characterized by excellent durability and an outstanding water-repellent effect, without hindering the passage of water vapor.
Silicates, such as silicate ester, are used in stone conservation. The addition of this binder stabilizes the structure of stone damaged by weathering. The silicates used for stone strengthening are introduced into the construction material by immersion, and react with the capillary water of the pores. Silicate ester, particularly ethyl silicates, also have a proven track record as binders for zinc-rich coatings. Even under extreme conditions, they rapidly harden into chemically stable coatings that are well anchored and can be easily overpainted.
WACKER offers a wide range of organofunctional silanes. Organofunctional silanes are hybrid compounds that combine the functionality of a reactive organic group with the inorganic functionality of an alkyl silicate in a single molecule. As a result, organofunctional silanes can be used as molecular bridges between organic and inorganic materials.
WACKER offers silicates for construction chemical applications and coating systems. Silicates include all salts and esters of silicic acid. Organic silicates, such as the esters of mono and disilicic acids can only be produced synthetically. The inorganic silicates, with the exception of alkali silicates (water glass), are an important group of naturally occurring silicon-oxygen compounds (silicate materials).