Ultrathin polymethylmethacrylate polymer films
AssigneeHoechst Celanese Corporation
InventorRachel S. Kohn
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Abstract
Disclosed herein are pinhole-free, ultrathin, polymethylmethacrylate films having thicknesses of about 400 angstroms or less and a process to prepare them. The films find particular utility in separatory applications.
Claims17
A pinhole-free, polymethylmethacrylate polymer film having a thickness of about 400 angstroms or less prepared according to the process comprising:
- (a) preparing a casting solution containing a polymethylmethacrylate polymer in a mixture of alkyl acetates;
- (b) depositing the casting solution on water to form a free-standing film;
- and
- (c) removing the film from the water.
A pinhole-free, polymethylmethacrylate polymer film having a thickness of about 400 angstroms or less prepared according to the process comprising:
- (a) preparing a casting solution containing a polymethylmethacrylate polymer having a molecular weight, M.sub.w, greater than about 250,000 at about the three to about the twelve percent by weight level based upon the total weight of the casting solution, in about a 4:6 to about a 6:4 by volume ratio of ethyl acetate:
- pentyl acetate;
- (b) depositing the casting solution on water to form a free-standing film;
- and
- (c) removing the film from the water.
A pinhole-free, polymethylmethacrylate polymer film having a thickness of about 400 angstroms or less prepared according to the process comprising:
- (a) preparing a casting solution containing a polymethylmethacrylate polymer having a molecular weight, M.sub.w, greater than about 250,000 at about the three to about the twelve percent by weight level, based upon the total weight of the casting solution, in about a 4:4:6:6 to about a 6:6:4:4 by volume ratio of ethyl acetate:
- propyl acetate:
- butyl acetate:
- pentyl acetate;
- (b) depositing the casting solution on water to form a free-standing film;
- and
Dependencies are inferred from the claim text.