LOW-MOLECULAR, PHOSPHORUS-CONTAINING POLYACRYLIC ACIDS AND USE THEREOF AS SCALE INHIBITORS IN WATER SUPPLY SYSTEMS Russian patent published in 2016 - IPC C08F220/06 C08F2/38 C08F2/10 C08L33/02 C02F5/14 

FIELD: chemistry.

SUBSTANCE: invention relates to low-molecular weight, phosphorus-containing polyacrylic acids, to aqueous solutions containing same, a method for production thereof, as well as to use thereof as scale inhibitors in water supply systems. Described is an aqueous solution of polymers of acrylic acid with average molecular weight 1,000-4,000 g/mol. Aqueous solution is obtained by polymerisation of acrylic acid in feed mode with peroxodisulphate as initiator in presence of hypophosphite in water as solvent. Wherein (i) water is taken, and (ii) acrylic acid in acidic, non-neutralized form, aqueous peroxodisulphate solution and aqueous hypophosphite solution are added continuously, and (iii) a base is added on completion of acrylic acid feed to aqueous solution, wherein comonomer content does not exceed 30 wt%, based on total monomer content. At most 16 % of phosphorus is in form of connected at end of polymer chain phosphinate and/or phosphonate groups.

EFFECT: technical result is reduction of precipitation and deposits of calcium sulphate in water supply systems.

16 cl, 2 tbl, 15 ex