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US 5,707,493 AGranted
Temperature-activated polysilicic acids in paper production
AssigneeJ.M. Huber Corporation
InventorSakari Saastamoinen
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Abstract
A temperature-activated polysilicic acid is prepared by heating an acidified aqueous alkali metal silicate. The temperature-activated polysilicic acid is used in the production of paper for improvement of retention and water removal.
Claims32
A process for the production of paper comprising the steps of:
- adding components comprising a temperature-activated polysilicic acid having a specific surface area of at least about 1350 m.sup.2 /g and a cationic polymer to an aqueous fiber pulp suspension, said components being added in an amount to enhance at least one paper/paper processing characteristic selected from the group consisting of filler retention, water removal, paper mechanical properties, fine and colloid recovery, and filterability;
- and,
- carrying out sheet formation and water removal;
- wherein the temperature-activated polysilicic acid is produced by a process comprising the steps of heating an acidified aqueous alkali metal silicate at a temperature of about 30.degree. to 250.degree. C. at a pH of about 0 to 5.
1 more element
A method for improving retention in a papermaking process wherein a temperature-activated polysilicic acid having a specific surface area of at least about 1350 m.sup.2 /g and a cationic polymer are added to an aqueous fiber pulp suspension, said polysilicic acid being added in an amount to enhance filler retention;
- wherein the temperature-activated polysilicic acid is produced by a process comprising the steps of heating an acidified aqueous alkali metal silicate at a temperature of about 30.degree. to 250.degree. C. at a pH of about 0 to 5.
Dependencies are inferred from the claim text.