SILRES® BS 68
SILRES® BS 68 is a solvent-thinnable, silane/siloxane mixture. It is used in diluted form for the hydrophobic impregnation of mineral construction materials and as primer for mineral substrates. The concentrated product is also used for manufacturing bitumen-bound minerals or as a binder for mineral systems. The product develops its hydrophobic effect as a result of the reaction with atmospheric moisture or with water adsorbed onto the pores and capillary walls of the construction material. SILRES® BS 68 is characterized by higher alkali resistance compared to pure methyl silicone resins. The construction material's water vapor permeability is only slightly affected.
For impregnation or priming, the diluted solution of SILRES® BS 68 is applied to the construction material by flood coating or brushing. In general, it is sufficient to apply two coats, wet on wet, to the construction material, once its surface region has air-dried. Flooding is the best way to do this.
The amount of impregnant/primer consumed for applying two generous coats depends on the absorbency of the particular construction material. For cost calculations and specification writing, consumption should be determined on a sufficiently large test area (1-2 m²). This can also be used to test the effectiveness of the treatment.
Application in the Bulk In bituminous systems, SILRES® BS 68 is used to pretreat the mineral component. Improved affinity with the bitumen is usually observed after pre-treatment. If the product is to be used undiluted as a binder, it should be thoroughly mixed with the mineral matrix. Pressing is usually necessary to achieve setting simultaneously with the reaction.
SILRES® BS 68 can be diluted with water-free aliphatic or aromatic hydrocarbons or with absolute alcohol. The weight ratio should be between 1:11 and 1:15. Preferred solvents are hydrocarbons with low aromatic content, such as Shellsol T. Alcohols should only be used as diluents when contact with solvent-sensitive plastics (expanded polystyrene, bitumen, etc.) cannot be avoided during application.