Use of polyolethers for producing porous plastic coatings
AssigneeEvonik Operations GmbH
InventorsMichael Klostermann, Jan Marian Von Hof, Martin Glos, Christian Eilbracht, Verena Dahl, Oliver Springer, Hans Henning Wenk
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Abstract
The invention relates to the use of polyolethers as additives in aqueous polymer dispersions for producing porous polymer coatings, preferably for producing porous polyurethane coatings.
Claims23
A porous polyurethane coating, obtained by applying an aqueous polyurethane dispersion comprising a polyglycerol ether derivative, to a carrier, wherein the polyglycerol ether derivative is of the general formula 2:
- MaDbTc Formula 2
- where
- M=[C3H5(OR″)2O1/2]
- D=[C3H5(OR″)1O2/2]
- T=[C3H5O3/2]
- a=1 to 10,
- b=0 to 10,
- c=0 to 3,
- where the R″ radicals are independently identical or different monovalent aliphatic saturated or unsaturated hydrocarbyl radicals having from 2 to 38 carbon atoms or H, wherein at least one of the R″ radicals is a hydrocarbyl radical;
- and
- wherein the porous polyurethane coating has a mean cell size less than 150 μm.
A process for producing a porous polyurethane coating, including polyglycerol ether as additives in aqueous polyurethane dispersion, the process comprising
- a) providing a mixture comprising an aqueous polyurethane dispersion, at least one polyglycerol ether derivative of general formula 2
- MaDbTc Formula 2
- where
- M=[C3H5(OR″)2O1/2]
- D=[C3H5(OR″)1O2/2]
- T=[C3H5O3/2]
- a=1 to 10,
- b=0 to 10,
- c=0 to 3,
- where the R″ radicals are independently identical or different monovalent aliphatic saturated or unsaturated hydrocarbyl radicals having from 2 to 38 carbon atoms or H, wherein at least one of the R″ radicals is a hydrocarbyl radical
- b) foaming the mixture to give a homogeneous, fine-cell foam,
- c) optionally adding at least one thickener to establish the desired viscosity of the wet foam,
- d) applying a coating of the foamed polyurethane dispersion to a suitable carrier,
- e) drying the coating,
- wherein said porous polyurethane coating has a mean cell size less than 150 μm.
Dependencies are inferred from the claim text.