Process of forming multilayered structures
AssigneeMillipore Corporation
InventorWillem Kools
Life of this patent
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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.
Claims27
1) A process of forming multilayered microporous structures comprising the steps of:
- a. preparing two or more solutions of a polymer and a solvent for said polymer,
- b. cocasting the two or more solutions onto a support,
- c. effecting a phase separation of the two or more solutions and,
- d. recovering the microporous multilayered structure.
6) The process of claim wherein at least one of the two or more polymer solutions is a homogeneous solution.
8) A multilayered membrane formed of two or more layers, the membrane being microporous, integral and having been formed by a process of cocasting.
19) A multilayered, microporous membrane formed of two or more layers, the membrane being integral and said membrane being made by the process of:
- a. preparing two or more solutions of a polymer and a solvent for said polymer,
- b. cocasting the two or more solutions onto a support,
- c. effecting a phase separation of the two or more solutions and,
- d. recovering the multilayered structure.
20) A microporous, polymeric structure comprised of a first layer and a second layer, wherein at least the first layer is symmetrical.
21) A microporous, polymeric structure comprised of a first layer and a second layer, wherein at least the first layer is asymmetrical.
Dependencies are inferred from the claim text.