Aqueous polymer dispersion, its use and method for preparing aqueous polymer dispersion
AssigneeKemira Oyj
InventorsAnneli Lepo, Helena Peuranen
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Abstract
The invention relates to an aqueous polymer dispersion having a viscosity of ≤150 m Pas at 40% solids content and comprising polymer particles having a particle size D50 less than 85 nm. The polymer dispersion is obtainable by free radical emulsion copolymerisation of at least monomer (a) and monomer (b), where monomer (a) is at least one optionally substituted styrene and monomer (b) is at least one C1-C4-alkyl (meth)acrylate, in a reaction mixture comprising degraded starch which has an average molecular weight Mn<1000 g/mol. The invention relates also to the use of the polymer dispersion and method for preparing it.
Claims14
A coating composition for coating of paper, board or the like, having a solids content of 50-74% and a low shear viscosity <3500 mPas, the coating composition comprising:
- water,
- inorganic mineral particles, and
- additive(s), including binders and a rheology modifier,
- wherein the rheology modifier is an aqueous polymer dispersion having a viscosity of ≤150 mPas at 40% solids content and comprising polymer particles having a particle size D50 less than 85 nm, the polymer dispersion being obtainable by free radical emulsion copolymerization of at least monomer (a) and monomer (b), wherein
- monomer (a) is at least one optionally substituted styrene, and
- monomer (b) is at least one C1-C4-alkyl (meth)acrylate,
- in a reaction mixture comprising degraded starch which has an average molecular weight of Mn<1000 g/mol.
Dependencies are inferred from the claim text.