摘要 |
<p>There are provided aqueous emulsions useful for rendering porous substrates water repellent comprising (a) a hydrolyzable silane having a determinable pH-stable range, (b) an emulsifying agent having an HLB value of from 2 to 20, an effective amount of (c) a buffering compound to maintain the composition within the pH-stable range; and (d) water. Such buffered compositions are stable on long term storage and maintain high effective levels of active silane content even when they include biocides which may accelerate the hydrolysis of aqueous silane-containing compositions.</p> |