Foamed polymeric materials

• US 4,529,739 A
• Filed: 07/24/1984
• Issued: 07/16/1985
• Est. Priority Date: 07/24/1984
• Status: Expired due to Term

• Current Assignee: The Dow Chemical Company (Dow, Inc.)
• Original Assignee: The Dow Chemical Company (Dow, Inc.)
• Inventors: Erickson, Robert E., Wallace, Theodore C., Scott, Laurie J.
• Primary Examiner(s): Foelak, Morton
• Application Number:
  US06/633,833
• Time in Patent Office: 357 Days
• Field of Search: 521/72
• US Class Current: 521/72
• CPC Class Codes: C08J 9/02 using blowing gases generated by the reacting monomers or modifying agents during the preparation or modification of macromolecules
• CPC Class Codes: C08J 9/08 developing carbon dioxide

Abstract

Foamed water-swellable polymeric water absorbent materials are prepared by contacting a polymer capable of having a water-swellable character and containing acid moieties in acid form with a blowing agent such as sodium bicarbonate, which blowing agent is capable of neutralizing the acid moieties of the polymer. The foamed polymers are useful in a wide variety of water absorbent applications.

Claims

1. A process for preparing a foamed water-swellable polymeric water absorbent material, said process comprising contacting an aqueous polymer dispersion said polymer capable of having a water-swellable character and containing a functionally effective amount of pendant acid moieties in acid form with a carbon dioxide yielding compound decomposeable blowing agent which is capable of neutralizing an effective amount of pendant acid moieties.

2. A process of claim 1 wherein said polymer capable of having a water-swellable character is lightly crosslinked.

3. A process of claim 1 wherein said polymer is in the form of a latex.

4. A process of claim 1 wherein said polymer is simultaneously hydrolyzed.

5. A process of claim 1 wherein said polymer comprises from about 1 to about 60 weight percent of monomers containing acid moieties which are polymerized to form said polymer.

6. A process for preparing a foamed water-swellable polymeric water absorbent material, said process comprising contacting an aqueous polymer dispersion said polymer capable of having a hydrophilic character and containing a functionally effective amount of pendant acid moieties in acid form with a carbon dioxide yielding decomposable compound blowing agent which is capable of neutralizing an effective amount of pendant acid moieties and said polymer is simultaneously subjected to crosslinking.

7. A process of claim 6 wherein said polymer capable of having a water-swellable character is lightly crosslinked.

8. A process of claim 6 wherein said polymer is in the form of a latex.

9. A process of claim 6 wherein said polymer is simultaneously hydrolyzed.

10. A process of claim 6 wherein said polymer comprises from about 1 to about 60 weight percent of monomers containing acid moieties which are polymerized to form said polymer.