METHOD OF OBTAINING WATER-REDISPERSIBLE POLYMER POWDERS Russian patent published in 2017 - IPC C08F2/00 C08F265/04 C08F291/00 

FIELD: chemistry.

SUBSTANCE: method of obtaining water-redispersible polymer powders is described. It is defined as loading of reactor with at least two unsaturated monomers, one of which is hydrophilic, and the other one is hydrophobic, with polymerization initiator, after which carbon dioxide is injected into the reactor to specific pressure. The primary components are heated to a temperature that ensures transfer of carbon dioxide to supercritical state, during the polymerization the mixture is stirred to ensure its homogeneity. Monomers are taken in amount, providing production of polymer powder with molecular weight of not more than 100,000. The glass transition temperature is in range between 0 and +40°C, and the average calculated equivalent mass of the hydrophobic part of polymer powder is 1.3-1.5 times greater than theoretical equivalent mass of the hydrophobic part of the polymer, which enables to achieve solubility of polymer powder. A water-redispersible polymer powder has been also described. It is obtained by polymerizing a mixture of unsaturated monomers of at least one hydrophobic and at least one hydrophilic monomer in the presence of polymerization initiator and supercritical carbon dioxide.

EFFECT: method of obtaining water-redispersible polymer powders with homogeneous structure of polymer particles has been developed with simplification of technology.

57 cl, 6 dwg, 4 tbl, 30 ex