Use of weakly anionic copolymers as dispersing and/or grinding aid agent of an aqueous suspension of mineral materials

A dispersing and/or grinding agent comprising a copolymer comprising polymerized units of

• a) at least one anionic monomer with an unsaturated ethylenic chain and a monocarboxylic function,
• b) optionally, at least one anionic monomer with an unsaturated ethylenic chain and a dicarboxylic, sulphonic, phosphoric, phosphonic function or a combination thereof,
• c) at least one non-ionic monomer with an unsaturated ethylenic chain of formula (I):
• in which
• m and p represent a number of alkylene oxide units and are less than or equal to 150,
• n represents a number of ethylene oxide units and is less than or equal to 150,
• q represents a number at least equal to 1 and
• 5≦(m+n+p)q≦150
• R1 is hydrogen, methyl or ethyl radical,
• R2 is hydrogen, methyl or ethyl radical,
• R is selected from the group consisting of acrylurethane, methacrylurethane, α-α′-dimethyl-isopropenylbenzyl urethane and allyl urethane,
• R′ represents a hydrocarbon radical having 1 to 5 carbon atoms,
• d) optionally, an acrylamide monomer, methacrylamide monomer, a derivative thereof or a mixture thereof, or one or more non water-soluble monomers, and
• e) optionally, at least one monomer having at least two unsaturated ethylenic chains selected from the group consisting of ethylene glycol dimethacrylate, trimethylolpropane-triacrylate, allyl acrylate, an allyl maleate, methylenebisacrylamide, methylenebismethacrylamide, tetrallyloxyethane, a triallylcyanurate, and an allyl ether obtained from a polyol,
• wherein the total of a), b), c), d) and e) is 100%, and
• wherein the copolymer has a specific viscosity of no more than 10.

A process comprising:

• at least one of dispersing or grinding a mineral pigment, filler or combination thereof, in aqueous suspension in the presence of a water-soluble copolymer,
• wherein said water-soluble copolymer comprises polymerized units of
• a) at least one anionic monomer with an unsaturated ethylenic chain and a monocarboxylic function,
• b) optionally, at least one anionic monomer with an unsaturated ethylenic chain and a dicarboxylic, sulphonic, phosphoric, phosphonic function or a combination thereof,
• c) at least one non-ionic monomer having an unsaturated ethylenic chain of formula (I):
• in which
• m and p represent a number of alkylene oxide units and are less than or equal to 150,
• n represents a number of ethylene oxide units and is less than or equal to 150,
• q represents a number at least equal to 1 and
• 5≦(m+n+p)q≦150
• R1 is hydrogen, methyl or ethyl radical,
• R2 is hydrogen, methyl or ethyl radical,
• R is an acrylic ester, a methacrylic ester, a maleic ester, an itaconic ester, a crotonic ester, a vinyl phthalic ester, an unsaturated urethane, an allyl ether, a vinyl ether or an ethylenically unsaturated amide,
• R′ represents a hydrocarbon radical having 1 to 5 carbon atoms,
• d) optionally, an acrylamide monomer, methacrylamide monomer, a derivative thereof or a mixture thereof, or one or more non water-soluble monomers, and
• e) at least one monomer having at least two unsaturated ethylenic chains selected from the group consisting of ethylene glycol dimethacrylate, trimethylolpropane-triacrylate, allyl acrylate, an allyl maleate, methylenebisacrylamide, methylenebismethacrylamide, tetrallyloxyethane, a triallylcyanurate, and an allyl ether obtained from a pentaerythritol, sorbitol, sucrose or mixtures thereof,
• wherein the total of a), b), c), d) and e) is 100%, and
• wherein the copolymer has a specific viscosity of no more than 10.

A dispersing and/or grinding agent comprising a copolymer comprising polymerized units of

• a) at least one anionic monomer with an unsaturated ethylenic chain and a monocarboxylic function,
• b) optionally, at least one anionic monomer with an unsaturated ethylenic chain and a dicarboxylic, sulphonic, phosphoric, phosphonic function or a combination thereof,
• c) at least one non-ionic monomer with an unsaturated ethylenic chain of formula (I):
• in which
• m and p represent a number of alkylene oxide units and are less than or equal to 150,
• n represents a number of ethylene oxide units and is less than or equal to 150,
• q represents a number at least equal to 1 and
• 5≦(m+n+p)q≦150
• R1 is hydrogen, methyl or ethyl radical,
• R2 is hydrogen, methyl or ethyl radical,
• R is an acrylic ester, a methacrylic ester, a maleic ester, a itaconic ester, a crotonic ester, a vinyl phthalic ester, an unsaturated urethane, an allyl ether, a vinyl ether or an ethylenically unsaturated amide,
• R′ represents a hydrocarbon radical having 1 to 5 carbon atoms,
• d) optionally, an acrylamide monomer, methacrylamide monomer, a derivative thereof or a mixture thereof, or one or more non water-soluble monomers, and
• e) at least one monomer having at least two unsaturated ethylenic chains selected from the group consisting of ethylene glycol dimethacrylate, trimethylolpropane-triacrylate, allyl acrylate, an allyl maleate, methylenebisacrylamide, methylenebismethacrylamide, tetrallyloxyethane, a triallylcyanurate, and an allyl ether obtained from a pentaerythritol, sorbitol, sucrose or mixtures thereof,
• wherein the total of a), b), c), d) and e) is 100%, and
• wherein the copolymer has a specific viscosity of no more than 10.