Process of forming multilayered structures
AssigneeMillipore Corporation
InventorWillem Kools
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Abstract
The present invention provides for a method of producing an integral multilayered porous membrane by simultaneously co-casting a plurality of polymer solutions onto a support to form a multilayered liquid sheet and immersing the sheet into a liquid coagulation bath to effect phase separation and form a porous membrane. The support can be a temporary support or form an integrated support for the membrane. The plurality of layers may be of the same polymer or different, same concentration or viscosity or different and may be subjected to the same processing conditions or different ones to form unique structures.
Claims20
A multilayered microporous membrane comprising a first asymmetric microporous polymer layer having a first polymeric composition and at least a second asymmetric microporous polymer layer having a second polymeric composition which is different from the first polymeric composition, wherein the first and second layers are integral and an interfacial zone is located between and connects the polymer layers.
A multilayered microporous membrane comprising at least two adjacent microporous polymer layers having different polymers, wherein an interfacial zone is located between and connects the two adjacent layers of the multilayered microporous membrane, said interfacial zone having a subtle change in pore size between the adjacent layers.
A multilayered microporous membrane comprising at least two adjacent symmetrical microporous polymer layers having different pore sizes, wherein the multilayered membrane is continuous and an interfacial zone is located between and connects the two adjacent layers of the multilayered microporous membrane, said interfacial zone having a subtle change in pore size between the adjacent layers.
Dependencies are inferred from the claim text.