| 摘要 |
The invention relates to a process for preparing polyorganosiloxane emulsions whose internal phase comprises the active polyorganosiloxane substance and whose external phase comprises, in solution or dispersion, an emulsifier or an emulsifier mixture and, if desired; an emulsion-stabilizing protective colloid, to the polysiloxane emulsions thus obtainable and, in particular, to the use of these macroemulsions, so prepared, as defoamers. A first embodiment of the invention relates to a process for preparing polyorgano siloxane emulsions, which comprises a) formulating a mixture from: from 5 to 50% by weight of polyorganosiloxanes optionally comprising hydrophobic solid bodies, from 0 to 20% by weight of organic oil, from 0.5 to 10% by weight of one or more nonionic or anionic emulsifiers, from 40 to 95% by weight of water, and if desired, thickeners, protective colloids and/or auxiliary preservatives; b) passing this mixture through,, and dispersing it in, at least one interaction chamber having a capillary thickness of from 100 to 500 .mu.m :in a pressure range from 100 to 1000 bar; and c) releasing this mixture in an outlet reservoir, the average droplet sizes being from 0.5 to 100 .mu.m.
|
