Particulate absorbent material
AssigneeMicro Vesicular Systems, Inc.
InventorsDonald F. H. Wallach, An-Cheng Chang
Life of this patent
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Abstract
The present invention features methods of making absorbent material which exhibit excellent absorption for saline and other liquids as well as being biodegradable. The methods of the invention form a particulate which can be stored in dry form and rehydrated at any time. The particulate can be used to replace the presently utilized polyacrylate superabsorbers. The base material used in the methods of the invention is a carboxylated cellulosic material such as carboxymethylcellulose, preferably, a carboxymethylcellulose having a DS, or Degree of Substitution, of 0.5 or greater. The carboxylated cellulose material is reacted with two distinct agents; a cross-linking agent and a hydrophobicity agent to make the final absorbent.
Claims20
A method of making a particulate absorbent material comprising the steps of:
- A. reacting a carboxylated cellulosic material with
- i. a cross-linking agent, and
- ii. a hydrophobicity agent;
- B. separating the reaction product;
- and
- C. removing water from said reaction product until it is substantially dehydrated and a particulate is formed of said absorbent material.
A method of making a particulate absorbent comprising the steps of:
- forming an emulsion of carboxymethylcellulose having a DS greater than 0.5 in an organic solvent;
- reacting said carboxymethylcellulose with a cross-linking agent selected from the group consisting of primary and secondary chromium and aluminum alkoxides, ferric chloride, aluminum and chromium hydroxides, aluminum and chromium acetates, and mixtures thereof;
- reacting the carboxymethylcellulose with a hydrophobicity agent selected from the group consisting of monobasic and polybasic carboxylic acids having 2-16 carbon atoms, and salts, chlorides, and anhydrides thereof;
- and
- removing said organic solvent.
A method of making a particulate absorbent comprising the steps of:
- swelling particulates of carboxymethylcellulose having a DS greater than 0.5 in an aqueous solvent;
- reacting said carboxymethylcellulose with a cross-linking agent selected from the group consisting of primary and secondary chromium and aluminum alkoxides, ferric chloride, aluminum and chromium hydrates, aluminum and chromium acetates, and mixtures thereof;
- reacting the carboxymethylcellulose with a hydrophobicity agent selected from the group consisting of monobasic and polybasic carboxylic acids havings 2-16 carbon atoms, and salts, chlorides, and anhydrides thereof;
- and
- removing said aqueous solvent.
Dependencies are inferred from the claim text.