Composite membranes, processes for their preparation and their use
AssigneeBayer Aktiengesellschaft
InventorsKarlheinz Hildenbrand, Rolf Dhein, Willi Meister, Dittmar Nerger
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Abstract
Composite membranes of a macroporous filler-containing membrane of at least two incompatible polymers and a pore-free polyurethane membrane applied there to exhibit an improved action in the removal of benzenes optionally suhstituted by lower alkyl radicals, hydroxyl, chlorine or bromine from their mixtures with aliphatic and/or cycloaliphatic hydrocarbons, alcohols, ethers, ketones and/or carboxylic acid esters or from effluent.
Claims10
Composite membranes, comprising (i) a macroporous filler-containing membrane of at least two incompatible polymers and (ii) a pore-free polyurethane (PU) membrane applied to (i) said composite membranes, being prepared by (a) dispersing an insoluble filler in a solution containing said at least two incompatible polymers, the amounts of said polymers being such as which would normally lead to phase separation in the solution to form a homogeneous casting solution, (b) processing said solution into membranes and carrying out precipitation coagulation thereof and (c) applying a pore-free PU membrane to the macroporous filler-containing membrane so obtained.
Dependencies are inferred from the claim text.