Process for sizing paper with anionic hydrophobic sizing agents and cationic retention aids

Abstract

Sizing agents, some of which are known compounds and some of which are novel aromatic compounds which contain in the aromatic nucleus a single hydrophobic substituent containing at least 5 carbon atoms and at least one anionic group, said hydrophobic substituent being linked to the aromatic nucleus through an ester, amide, urethane or urea bridge, with the CO group of ester and amide bridges being attached to the hydrophobic radical and a methylene group being optionally present between said bridges and the aromatic nucleus, are particularly suitable, together with commercially available retention aids, for use in a process for the mass sizing of paper or cardboard or for the surface sizing of paper.

Dependencies are inferred from the claim text.