Claims
- 1. A method of preparing a substantially dry, water swellable polyelectrolyte film which comprises the steps of
- A. applying a coating on an impervious substrate wherein the coating comprises
- 1. a solution of a carboxylic synthetic polyelectrolyte wherein the solution consists of water, lower alcohols, or mixtures thereof and about 5 to about 60% by weight of a carboxylic polyelectrolyte, and
- 2. at least about 0.1% by weight based on the polyelectrolyte of a crosslinking agent reactive with carboxylate groups
- B. heating said coated substrate to a temperature greater than about 30.degree. C. to crosslink said polyelectrolyte to form a film, and
- C. separating said crosslinked polyelectrolyte film from said substrate.
- 2. The method as set forth in claim 1 wherein the solution used comprises
- 1. water, lower alcohols, and mixtures, thereof,
- 2. about 5 to about 60% by weight based on the amount of (1) of a carboxylic polyelectrolyte or mixtures thereof, and
- 3. at least about 0.1% by weight based on the polyelectrolyte of a crosslinking agent selected from polyhaloalkanols, sulfonium zwitterions, haloepoxyalkanes, polyglycidyl ethers, and mixtures thereof.
- 3. The method as set forth in claim 1 wherein the solution used comprises
- 1. water, lower alcohols, and mixtures thereof,
- 2. about 5 to about 60% by weight based on the amount of (1) of a carboxylic polyelectrolyte or mixtures thereof, and
- 3. at least about 0.1% by weight based on the polyelectrolyte of a polyglycidyl ether crosslinking agent.
- 4. The method as set forth in claim 3 wherein the polyglycidyl ether crosslinking agent is a polypropylene glycol diglycidyl ether having an epoxy equivalent weight range from about 175 to about 380.
- 5. The film prepared by the method of claim 1.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a divisional application of Ser. No. 468,794 filed May 9, 1974 now U.S. Pat. No. 3,980,663, patented Sept. 14, 1976, which is a continuation-in-part of Ser. No. 371,909 filed June 20, 1973, which is now abandoned.
US Referenced Citations (4)
Foreign Referenced Citations (1)
Number |
Date |
Country |
540,530 |
Oct 1941 |
UK |
Divisions (1)
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Number |
Date |
Country |
Parent |
468794 |
May 1974 |
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Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
371909 |
Jun 1973 |
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