Patent ID: 7189776

Claim:
An aqueous composition comprising anionic organic polymeric particles and colloidal anionic silica-based particles having a specific surface area within the range of from 300 to 1000 m 2 /g, the anionic organic polymeric particles being obtained by polymerising one or more ethylenically unsaturated monomers together with one or more polyfunctional branching agents and/or polyfunctional crosslinking agents, the anionic organic polymeric particles and the colloidal anionic silica-based particles being present in an amount of within the range of from 1 to 45% by weight based on the total weight of the aqueous composition, the colloidal anionic silica-based particles being silica, aluminium-modified silica or amine-modified silica and being contained in a sol having an S-value within the range from 5 to 60% before mixing with the anionic organic polymeric particles.