Water soluble or non-water soluble polymer made of, expressed in % by weight of each monomer: a) from 30% to 60% of at least one hydroxy and/or methoxy polyalkylene glycol monomer with the formula R - m - n - R', with: - m and n designating integers that are less than or equal to 150, at least one of which is non-zero, - EO and PO respectively designating ethylene oxide and propylene oxide, - R designating the methacrylate or methacrylurethane function, - R' designating a hydroxy or methoxy group, b) from 20% to 60% of at least one hydrophobic monomer chosen from styrene and the (meth)acrylic esters with from 1 to 4 carbon atoms, c) from 0.1% to 10% of at least one monomer which is acrylic and/or methacrylic acid, d) from 0 to 5% of an associative monomer with the formula R - m - n - R', with: - m and n designating integers that are less than or equal to 150, at least one of which is non-zero, - EO and PO respectively designating ethylene oxide and propylene oxide, - R designating the methacrylate or methacrylurethane function, - R' designating an alkyl or aryl or alkylaryl group with from 8 to 32 carbon atoms, linear or branched, e) from 0 to 5% of a monomer with two ethylenic unsaturations, the sum of the percentages a), b), c), d) and e) being equal to 100%, characterized in that it is partially or totally neutralized by one or several neutralization agents, except the polymer consisting of 51.5% by weight of butylacrylate, of 40.0% by weight of polyethyleneglycol monomethyl ether monomethacrylate (Mw 400), of 4.85% by weight of methylmethacrylate, of 2.00% by weight of methacrylic acid, of 0.10% by weight of 2-hydroxy-2-methyl-1-phenyl-1-propan (CAS # 7473-98-5), of 0.05% by weight of hexanediol dimethacrylate. a) from 30% to 60% of at least one hydroxy and/or methoxy polyalkylene glycol monomer with the formula R - m - n - R', with: - m and n designating integers that are less than or equal to 150, at least one of which is non-zero, - EO and PO respectively designating ethylene oxide and propylene oxide, - R designating the methacrylate or methacrylurethane function, - R' designating a hydroxy or methoxy group, - m and n designating integers that are less than or equal to 150, at least one of which is non-zero, - EO and PO respectively designating ethylene oxide and propylene oxide, - R designating the methacrylate or methacrylurethane function, - R' designating a hydroxy or methoxy group, b) from 20% to 60% of at least one hydrophobic monomer chosen from styrene and the (meth)acrylic esters with from 1 to 4 carbon atoms, c) from 0.1% to 10% of at least one monomer which is acrylic and/or methacrylic acid, d) from 0 to 5% of an associative monomer with the formula R - m - n - R', with: - m and n designating integers that are less than or equal to 150, at least one of which is non-zero, - EO and PO respectively designating ethylene oxide and propylene oxide, - R designating the methacrylate or methacrylurethane function, - R' designating an alkyl or aryl or alkylaryl group with from 8 to 32 carbon atoms, linear or branched, - m and n designating integers that are less than or equal to 150, at least one of which is non-zero, - EO and PO respectively designating ethylene oxide and propylene oxide, - R designating the methacrylate or methacrylurethane function, - R' designating an alkyl or aryl or alkylaryl group with from 8 to 32 carbon atoms, linear or branched, e) from 0 to 5% of a monomer with two ethylenic unsaturations,