| 摘要 |
<p>A process for making a foam control composition comprising a cross-linked polyorganosiloxane in which is dispersed a filler, with hydrophobic surface, comprising step (A) mixing (i) a finely divided filler, (ii) a polyorganosiloxane having on at least two reactive substituents, for example on average two reactive substituents, and (iii) a polyorganosiloxane having at least three reactive substituents, capable of addition reaction via hydrosilylation; (B) hydrosilylation reaction of components (ii) and (iii) until the mixture at least partially gels, followed by applying shearing forces to this at least partially gelled mixture. Optionally step (A) comprises a diluent or solvent and after step (B) an emulsification step is carried out to make the foam control composition into an O/W emulsion. Also a process for controlling foam in an aqueous environment by using a foam control composition according to the invention, selected from inks, coatings, paints, detergents, black liquor of from those encountered during pulp and paper manufacture, waste water treatment, textile dyeing processes or the scrubbing of natural gas.</p> |
