Patent ID: 6132804
Filing Date: 2000-10-17
Classification: B01D,B05D

Abstract:
A process for continuously coating a continuous porous substrate to prepare a composite filtration membrane comprising:providing a first liquid component;providing a first applicator means for applying the first liquid component onto the substrate, wherein said first applicator means comprises a slot die head or a direct gravure applicator;applying a quantitative amount of the first component onto the substrate to coat the substrate and form a liquid layer by relatively moving the substrate and the first applicator with respect to each other at a speed of between 20 and 200 feet per minute;providing a second liquid component;providing a second applicator means in tandem with the first applicator means for applying the second liquid component, wherein said second applicator means comprises a slot die head;applying a quantitative amount of the second liquid component onto the liquid layer to contact the second liquid component with the liquid layer by relatively moving the substrate coated with the liquid layer and the second applicator with respect to each other;allowing the first and second liquid component to interfacially polymerize to form a composite layer of a thickness of between about 25 .ANG. and 1 micron; anddrying the composite layer to form a composite membrane.