PROCEDURE FOR ANTI-FUMPING OF Aqueous DISPERSIONS AND POLYMERS ORGANIC SUBSTANCES BY ADDING POLYOXYLYCLE-POLYSILOXAN BLOCK COPOLYMERISATES

Abstract

Abstract Process for the defoaming of aqueous dispersions of polymeric organic substances, particularly dispersions of binders, coating agents and adhesives, by addition of polyoxyalkylene/polysiloxane block copolymers, where the polyoxyalkylene/polysiloxane block copolymers used are those of the general formula R<1>O-A-[B-A-]mR<1> in which A is a polyoxyalkylene block of the average formula (CnH2nO-)y, in which n has a value of 2.8 to 4.0 and y has a value from 15 to 100, B is a polysiloxane block of the average formula <IMAGE> in which R<2> is identical or different and is an alkyl radical having 1 to 4 carbon atoms or a phenyl radical, however at least 90% of the R<2> radicals are methyl radicals and x has a value from 10 to 100, R<1> is identical or different and is a hydrogen or alkyl radical having 1 to 4 carbon atoms and m has a value from 4 to 20, in amounts of 0.01 to 2.0% by weight, relative to the dispersion to be defoamed. <??>The block copolymers to be used according to the invention show outstanding defoaming action, the particular advantage particularly lying in the fact that when the defoamed dispersions are applied to a flat substrate no defects in wetting occur.

Inventors

• 👤 Roland Berger
• 👤 Hans-Ferdi Fink
• 👤 Otto Klocker
• 👤 Roland Sucker

Bibliographic Details