grinding and/or dispersion aids based on polymers and/or partly magnesium neutralised copolymers for aqueous suspensions of mineral materials suitable for pigmentary applications

摘要

Grinding aid based on polymers and/or copolymers partially neutralised with magnesium for aqueous suspensions of inorganic materials with a view to pigment applications. Grinding aid consisting of polymers and/or copolymers of specific viscosity of between 0.3 and 0.8 and obtained by treatment, with the aid of one or a number of polar solvents, of a polymer and/or copolymer which results from the polymerisation and/or copolymerisation of acrylic and/or vinyl monomers containing acidic groups in which the active acidic sites are partially or completely neutralised with a degree of neutralisation of the active acidic sites by a neutralising agent providing the magnesium ion ranging from 40 % to 60 %, limits included, and by a neutralising agent containing the sodium ion ranging up to 60 %. Process for grinding in aqueous suspension employing the said aid, and aqueous suspensions obtained by the said process and their applications in the field of mass filler, paper coating, paint and plastics.