Masonry water repellants properties

A substance that, because of its physicochemical nature, will not mix or blend with another substance.. All hydrophobic materials have water-repellent properties due largely to differences in surface tension or electric charges, e.g., oils, fats, waxes, and certain types of plastics. Silicone resin coatings can keep water from penetrating masonry by lining the pores, not by filling them they will not exclude water under pressure. 

Silicones have been used as masonry water repellents for more than 40 years. Mineral btiilding materials absorb water and change their properties. The source of water is moisture, frost and efflorescence. The absorption of water depends on the porosity of the material. Water conveys destructive agents inside the building material, causing damage to the building. The absorption of water occurs by a number of routes (Wacker-Chemie, 1989), as will now be described. 

The clear-colorless nature of silicone repellents allows preservation of the original appearance of the concrete. Their lack of film formation leaves the masonry pores open, thereby allowing transport of moisture outward to the atmosphere. They are highly durable to environmental conditions and will retain their repellent properties for several years. There are two types of water-repellent silicones (1) one is the resin-solvent type that is characterized as a partially hydrolyzed, partially alcoholized silicone resin dissolved in a hydrocarbon solvent. Generally, such products approach the 5% nonvolatile level. (2) The second is a water-soluble alkaline silicone repellent that is recommended for use on limestone and other nonsiliceous stone and masonry. 

Uses Water repellent for coatings, masonry surf., silicate coatings, pipe insulation, and wallboard Features No VOCs, water-dilutable Properties Clear to si. yel. Iiq. 40% cone, in water Precaution Nonflamm. 

Uses Film-former, binder in coatings, protective coatings improves weathering in paints water repellent for masonry Features Rec. for applic. to substrates exposed to high temps. Properties Colorless to straw clear to hazy liq. sp.gr. 1.07 dens. 8.9 lb/ gal flash pt. (PMCC) 88 F... 

Uses Primer, water repellent, paint adhesion promoter for masonty Features Penetrates deeply into new or existing masonry surfs, to form flat penetrating masonty primer, or clear water repellent low VOC strengthens substrate max. water tepellency will be realized in 72 h Properties Yel. or orange liq. sp.gr. 1.02 flash pt. 67 F ref. index 1.42 VOC 252 g/l 100% silicone content... 

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