POLYMER BLENDS AS COATING INHIBITORS IN WATER-CARRYING SYSTEMS

摘要

The invention relates to a polymer blend in solid or aqueous form containing, relative to the polymer content, (A) 5 to 95 wt% of a water-soluble or water-dispersible polymer with an average molecular weight of 1000 to 20000 g/mol consisting of (a1) 20 to 80 wt% of at least one monomer, selected from the group consisting of C2-C8 olefins, allyl alcohol, isoprenol, C1-C4 alkyl vinyl ethers and vinyl esters of C1-C4 monocarboxylic acids, (a2) 20 to 80 wt% of at least one monoethylenically unsaturated C3-C8 carboxylic acid, an anhydride or a salt thereof, (a3) 0 to 50 wt% of one or more monomers containing sulphonic acid groups, (B) 5 to 95 wt% of a water-soluble or water-dispersible polymer with an average molecular weight of 1000 to 50000 g/mol consisting of (b1) 30 to 100 wt% of at least one monoethylenically unsaturated C3-C8 carboxylic acid, an anhydride or a salt thereof, (b2) 0 to 70 wt% of one or more monomers containing sulphonic acid groups, (b3) 0 to 70 wt% of at least one non-ionic monomer of formula (I), H2C=C(R1)(CH2)xO[R2-O]o-R3, wherein R1 represents hydrogen or methyl, R2 represents the same or different, linear or branched C2-C6 alkylene groups, which can be arranged block-wise or statistically, and R3 represents hydrogen or a straight-chain or branched C1-C4 alkyl group, x representing 0, 1 or 2 and o for a number between 3 and 50.