TECHNOLOGY (PROCESS) FOR OBTAINING WATER POLYURETHANE DISPERSION Russian patent published in 2023 - IPC C08G18/48 C08G18/42 C08G18/32 C08G18/66 C08G18/75 C08J3/03 C09D175/04 C09D175/06 

FIELD: polymers.

SUBSTANCE: invention relates to a method for producing an aqueous polyurethane (PU) dispersion, the use of which can significantly improve the environmental safety of materials used in the production of coatings and adhesives. The method for producing an aqueous polyurethane dispersion includes the following steps: dehydration of the polyester polyol by heating under vacuum; transferring the polyester polyol to a prepolymer synthesis reactor; supply of organic acid and solvent, and stirring of the resulting mixture to homogenize the reaction mass at a temperature of 90-92°C at a rate not higher than 900 rpm; the introduction of cycloaliphatic diisocyanate and the implementation of the synthesis of the prepolymer in a nitrogen atmosphere with stirring to the content of the calculated amount of residual isocyanate groups; neutralization of carboxyl groups with a tertiary amine; transferring the prepolymer melt into the dispersant reactor, in which the aqueous phase is located, with the defoamer added to it; introduction into the dispersion of a water-soluble amine "A" - a diamine of a neutralized sulfonic acid with a functionality according to the sulpho-group 1 of the general formula Н₂N--CH₂--CH₂--NH--(CH₂)_x–SO₃Na, where х=1-3. In the prepolymer dispersion stage, the mixing rate is increased to at least 1200 rpm and the mixing is maintained at the specified rate until the dispersion production process is completed.

EFFECT: method results in a decrease in the aggregation of polymer particles (globules) and an increase in the adhesive properties of the dispersion.

10 cl, 2 ex