Grinding and/or for dispersing aid of mineral materials in aqueous suspension, resulting aqueous suspensions and uses thereof

A dispersion and/or grinding-aid agent for mineral fillers in aqueous suspension, the agent comprising homopolymers and/or copolymers of acrylic and/or methacrylic acid with one or more acrylic, vinyl or allyl monomers, characterised in that the said homopolymers and/or copolymers of acrylic and/or methacrylic acid with one or more acrylic, vinyl or allyl monomers are neutralised so that the molar percentage of the active acid sites of the non-neutralised polymer is between 10% and 30% and that of the active acid sites neutralised by at least one at least bifunctional neutralisation agent is between 10% and 80%, the remainder to 100% of the active acid sites of the polymer being neutralised by monofunctional neutralisation agents.