| 摘要 |
<p>Aqueous siloxane and siloxane/silane emulsions are provided together with a method of providing them. The aqueous siloxane emulsion prepared in accordance with the invention comprises: (i) hydrolysable alkylalkoxysiloxane having general formula (I), wherein R represents a hydrocarbyl group containing from 1 to 30 carbon atoms, b is 0, 1 or 2, and R' represents an aliphatic group containing from 1 to 10 carbon atoms, (ii) 0,1 % to 10 % by weight of a surfactant selected from the group consisting of an alkylamine alkoxylate, or, an acidified or partially acidified alkylamine alkoxylate, quaternary alkyl ammonium salts, acid alkylamine salts and imidazoline salts; and (iii) water. The invention also provides that up to 45 % by weight of the emulsion may be alkylalkoxysilane of the formula: R'n - Si - R'''4-n wherein R' is a hydrocarbyl group containing from 1 to 20 carbon atoms, R''' is a hydrolysable group, and n is 1 or 2. These emulsions maintain high effective levels of the active silicone content on long term storage. The emulsions of the invention are useful in rendering permeable mineral substrates water repellent.</p> |
