Allied Colloids Limited

Minerals Technologies Inc.

Mineral Technologies, Inc.

Bruce Evans

Brian Frederic Satterfield

Thomas Adrian Cauley

David Depasquale

Filled paper is made by adding a cationising amount of cationic polymer to a slurry of precipitated calcium carbonate, mixing this slurry into a cellulosic suspension and forming a thin stock, adding anionic particulate material to the suspension before or after the slurry, mixing a polymeric retention aid into the thin stock which includes the precipitated calcium carbonate and the anionic particulate material, draining the thin stock on a screen to form a sheet and drying the sheet. A suitable slurry for this purpose is a slurry of 5 to 70% by weight precipitated calcium carbonate and cationic polymer selected from 0.1 to 1% cationic starch and 0.01 to 0.3% of a high charge density, relatively low molecular weight, cationic polymer.

Production of filled paper

Filled paper is made by adding a cationising amount of cationic polymer to precipitated calcium carbonate or other filler either as a slurry or in a thick stock component, producing a thin stock containing the cationised filler and then treating the thin stock with a formaldehyde resin and polyethylene oxide as a retention system prior to drainage and drying.

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Bethlehem, PA, United States of America

Bruce Evans