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US 7,030,199 B1Granted
Method for producing water-soluble or water-swellable polymerizates with a very low residual monomer content, products produced according to this method and the use thereof
AssigneeStockhausen GmbH & Co. KG
InventorsMiroslav Chmelir, Kurt Dahmen
Life of this patent
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Abstract
The invention relates to a process for producing water-soluble or water-swellable polymer products from acrylic acid and/or acrylic acid derivatives partially or completely neutralized with nitrogen compounds and with exceedingly low levels of residual monomers, which process is characterized by subsequent heating of the polymer product at temperatures of from 120 to 240° C. The polymers produced accordingly are suitable for use as flocculants, dispersants and absorbers.
Claims18
A process for producing a water-soluble or water-swellable polymer or copolymer comprising:
- providing an acid monomer alone, or in combination with at least one comonomer;
- partially or completely neutralizing said at least one monomer with at least one basic nitrogen compound;
- free-radical polymerizing said at least one monomer alone, or in combination with said at least one comonomer to form said water-soluble or water-swellable polymer or copolymer,
- wherein said free-radical polymerization is started at a temperature of from 0 to 50° C and is performed in aqueous solution at a maximum temperature of no more than 102-104° C, to provide an aqueous polymer or copolymer solution or an aqueous polymer or copolymer gel;
- and,
- subsequent to completion of said free-radical polymerization, heating said water-soluble or water-swellable polymer or copolymer at a temperature of from 120° to 240° ;
- wherein said heating is caried out for a time period between 10 minutes and 2 hours;
- wherein the water-soluble or water-swellable polymer or copolymer has a content of residual monomer of less than 50 ppm.
5 more elements
Dependencies are inferred from the claim text.