METHOD OF PRODUCING AQUEOUS POLYURETHANE DISPERSION Russian patent published in 2019 - IPC C08G18/48 C08G18/42 C08G18/32 C08G18/38 C08G18/61 C09D175/04 C09D175/02 C08J3/03 

FIELD: manufacturing technology.

SUBSTANCE: present invention relates to a method of producing an aqueous polyurethane dispersion used in production of coatings and adhesives. Said method comprises the following steps: preliminary dehydration of polyol component in reactor at 93–95 °C under vacuum to residual moisture content of not more than 0.03 % with subsequent supply of mixture of organic acid and solvent, stirring at 50–80 °C and introduction of an isocyanate component, synthesis of prepolymer at 25–90 °C in nitrogen atmosphere to content of calculated amount of residual isocyanate groups, neutralization of carboxyl groups with a tertiary amine at 40–80 °C for 0.5–3 hours, dispersion of prepolymer in water with addition of antifoaming agent, after which introduction of amine "A2" is carried out, then at pH within 6.0–7.0 introduction of amine "A1" is carried out and maintenance till complete disappearance of NCO-groups. Amine "A1" is a product of hydrolysis and subsequent polycondensation of amino alkoxysilane H₂NR-Si-(OAlk)₃ of general formula H₂N-R-Si(OAlk)₂-O-Si(OAlk)₂-R-NH₂. Amine "A2" is a water-soluble amine with functionality on NH_2-group from 2 to 4. Isocyanate component is a diisocyanate and/or polyisocyanate with functionality of 2 to 3 on the NCO-group. Polyol component is at least one polyether-polyol functional with OH-groups from 1.9 to 4 and hydroxyl number from 14 to 250. Solvent can be dissolved in the organic and aqueous phases. Organic acid has functionality on COOH groups from 1 to 3 and OH groups from 2 to 3.

EFFECT: coatings and adhesives obtained based on said aqueous polyurethane dispersion have high adhesion properties.

4 cl, 1 tbl, 6 ex