Waterproof and breathable, porous membranes
AssigneeETH Zurich
InventorsWendelin Jan Stark, Mario Stucki
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Abstract
The invention relates to manufacturing processes for waterproof and breathable porous polymer membranes by coating a substrate with a dispersion comprising polymer, coated particles and diluent and removing the particles by dissolution, wherein the particles are made of organic salts, metal salts or metal oxides and the coating material is selected from carboxylic acids and alkoxy silanes. The invention further relates to dispersions to obtain such membranes, to polymer membranes obtained, to shaped articles containing such membranes; to the use of such membranes, shaped articles and intermediates.
Claims9
A method of manufacturing a porous polymer membrane having a pore size of 5-1000 nm, comprising the steps of
- a) providing a dispersion comprising
- one or more diluents in an amount of at least 40 wt. %,
- one or more polymers dissolved therein,
- one or more coated particles dispersed therein,
- optionally one or more additives dissolved therein
- whereby the ratio (wt %) of polymer:
- coated particles is in the range of 2:1 to 0.01:1, and
- whereby the coated particles are pre-manufactured,
- are selected from the group consisting of organic salts, metal salts, metal oxides and combinations thereof,
- the coating material is selected from the group of carboxylic acids, aryl-alkoxy-silanes alkyl-aryl-alkoxy-silanes and alkyl-alkoxy-silanes, and
- have a particle size in the range of 5-1000 nm;
- b) coating a substrate with said dispersion;
- c) optionally subjecting the obtained material to a drying step;
- d) optionally subjecting the thus obtained material to a polymerisation or cross-linking step;
- e) removing said one or more particles by a dissolution step;
- f) optionally removing the obtained polymer membrane from said supporting material.
Dependencies are inferred from the claim text.