| 摘要 |
The aqueous reaction products of monoalkylchlorosilanes with aqueous dispersions of Ca(OH)2 (see Division C3), are used for rendering masonry materials water-repellent. Materials specified are articles or building structures made from concrete, brick, cinder block, stucco and water-mixed cement coatings. The reaction product can be used in an amount as low as 0.1% by weight of the masonry material to be impregnated. In Examples (i) an aqueous reaction product of Ca(OH)2 and CH3SiCl3 was added to a lime paint composed of slaked lime and ferric oxide; (ii) the reaction product of (i) was added to a mixture of plaster and water and the resulting mix was poured out and allowed to dry as a slab; (iii) the aqueous reaction product of Ca(OH)2 with a mixture of CH3SiCl3 and CH3SiH.Cl2 was added to a lim mortar; (iv) the aqueous reaction product of Ca(OH)2 and CH3SiHCl2 was added to plaster; and (5) the reaction product of (i) was added to a mix of cement, sand and water.ALSO:A silicone water repellent for masonry materials is made by reacting one or more monoalkylchlorosilanes with an excess (i.e. more than 1.5 mols per mol of silane) of calcium hydroxide dispersed in water. Silanes specified are RSiCl3 and RHSiCl2, in which R can be methyl, ethyl, propyl, butyl or octadecyl. In a typical example (1) an aqueous slurry was stirred with CH3SiCl3 and heated to yield, after filtration of removal of CaCl2 by washing, a paste-like reaction product containing 38% water. |
