Polysilicate microgels as retention/drainage aids in papermaking
AssigneeE. I. Du Pont de Nemours and Company
InventorJohn D. Rushmere
Life of this patent
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Abstract
The use of anionic polysilicate microgels with an organic polymer to flocculate pulp and filler fines, such that water removal is easier and fines retention is greater.
Claims7
A method for improving retention and drainage in a papermaking process of the type wherein aqueous paper furnish containing pulp is formed and dried which comprises adding to the pulp a water soluble polysilicate microgel formed by partial gelation of an alkali metal silicate in combination with at least about 0.001 wt percent, based on the dry weight of the paper furnish, of a water soluble cationic polymer.
In a papermaking process of the type in which an aqueous paper furnish containing pulp is formed and dried, the improvement comprising sequentially adding to the pulp a water soluble polysilicate microgel in an amount of from about 0.001 to 1.0 wt%, based on the dry weight of the paper furnish, and at least about 0.001 wt%, based on the dry weight of the paper furnish, of a water soluble cationic polymer to improve drainage and fines retention.
Dependencies are inferred from the claim text.