POLYURETHANE FOAMS HAVING SUFFICIENT HARDNESS AND GOOD FLEXIBILITY Russian patent published in 2020 - IPC C08G18/40 C08G18/76 C08G18/48 C08G18/63 C08G101/00 

FIELD: manufacturing technology; chemistry.

SUBSTANCE: present invention relates to a reaction system for producing foamed polyurethane material, as well as a method for production thereof. Reaction system contains at least a polyisocyanate composition and a composition of reagents which are reactive with respect to isocyanate. Functionality of the polyisocyanate composition is between 2.2 and 2.7. Composition of reagents reactive with respect to isocyanate contains a) at least one polyoxyethylene-based polyether polyol and b) at least one polymer polyether polyol. Polyoxyethylene-based polyether polyol has average nominal hydroxyl functionality of 2.5–3.5, a hydroxyl number higher than 350 and content of ethylene oxide is more than 85 wt %. Polymer polyether polyol has molecular weight within 2,000–7,000 and content of solid particles within 20–45 wt % with respect to total weight of polymer polyol. Method of producing the foamed polyurethane material involves reaction of a reaction system with an isocyanate index of 90–120.

EFFECT: obtained material has low density, sufficient hardness and good flexibility and mechanical strength.

11 cl, 2 tbl, 1 ex