Water-retaining and optical-brightener-activating polymer composition, paper coating colors and sheets of coated paper thus obtained

Abstract

A stable aqueous liquid polymer composition, which comprises: (i) at least one polyvinyl alcohol (PVA) which has an Ostwald viscosity less than 5 mPa·s corresponding to a degree of polymerization less than 600 and a molar percentage of hydrolysis ranging from 70 to 100 measured from the ester value (DIN 53401), corresponding to a molar percentage of vinyl acetate units from 30 to 0, and (ii) at least one water-soluble polymer at neutral or alkaline pH, the composition controlling the activation of optical brighteners, water retention and viscosities of paper coating colors.

Dependencies are inferred from the claim text.