Claims
- 1. A substantially dry water swellable particulate polyelectrolyte produced by the method which comprises
- 1. preparing a solution,
- I. which comprises a solvent selected from the group consisting of water, lower alcohols and mixtures thereof, and
- Ii. about 5 to about 60% by weight based on (I) of a crosslinkable carboxylic copolymer which contains in the copolymer
- A. about 25 to about 98% by weight based on the total weight of the copolymer of units derived from an alkali metal salt of an olefinically unsaturated monosulfonic or monocarboxylic acid;
- B. about 2 to about 50% by weight of units derived from an olefinically unsaturated monocarboxylic acid; and
- C. about 0.1 to about 5.0% by weight of units derived from an N-substituted acrylamide or methacrylamide having the formula
- H.sub.2 C=CR--C(O)--NHCH.sub.2 --O--R'
- wherein R is selected from hydrogen or methyl and R' is hydrogen or an alkyl group of 1-8 carbons,
- 2. spreading a coating of said solution on an impervious substrate,
- 3. heating said coated substrate to a temperature greater than about 30.degree. C to crosslink said polyelectrolyte,
- 4. separating said crosslinked polyelectrolyte film from said substrate, and
- 5. disintegrating said film to form flakes, strips, or powders thereof.
- 2. The particulate polyelectrolyte as set forth in claim 1 wherein the crosslinkable carboxylic copolymer contains 90 weight percent of units derived from sodium acrylate, 9 weight percent of units derived from acrylic acid and 1.0 weight percent of units derived from N-methylolacrylamide.
- 3. The particulate polyelectrolyte as set forth in claim 1 wherein the crosslinkable carboxylic copolymer contains 79 weight percent of units derived from sodium styrene sulfonate, 20 weight percent of units derived from acrylic acid and 1.0 weight percent of units derived from N-methylolacrylamide.
- 4. The particulate polyelectrolyte as set forth in claim 1 wherein the crosslinkable carboxylic copolymer contains 90 weight percent of units derived from sodium acrylate, 9 weight percent of units derived from acrylic acid and 1.0 weight percent of units derived from N-isobutoxymethylacrylamide.
- 5. The particulate polyelectrolyte as set forth in claim 1 wherein the crosslinkable carboxylic copolymer contains 79.7 weight percent of units derived from sodium acrylate, 20 weight percent of units derived from acrylic acid, and 0.3 weight percent of units derived from N-methylolacrylamide.
- 6. The particulate polyelectrolyte as set forth in claim 1 wherein the crosslinking agent is N-isobutoxymethyl acrylamide.
CROSS-REFERENCE TO RELATED APPLICATION
This is a divisional, of application Ser. No. 494,439, Filed Aug. 5, 1974.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
2701391 |
Yost et al. |
Feb 1955 |
|
3808305 |
Gregor |
Apr 1974 |
|
3957710 |
Rohmann et al. |
May 1976 |
|
Foreign Referenced Citations (1)
Number |
Date |
Country |
1,209,333 |
Oct 1970 |
UK |
Divisions (1)
|
Number |
Date |
Country |
Parent |
494439 |
Aug 1974 |
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