METHOD FOR PRODUCING RIGID POLYURETHANE FOAM MATERIALS Russian patent published in 2016 - IPC C08G18/50 C08G18/48 C08G18/28 C08G18/40 C08G65/26 

FIELD: chemistry.

SUBSTANCE: present invention relates to a method for the production of polyurethane rigid foams by reacting polyisocyanates with at least three different compounds each having at least two reactive isocyanate groups with hydrogen atoms in the presence of blowing agents. One of three said compounds (i) is a polyether alcohol component obtainable by reacting a mixture of melamine and at least one hydroxyl- and amino-functional compound with alkylene oxide. Second of three compounds (ii) is a polyether alcohol component, having a hydroxyl number of 300 to 600 mg KOH/g coupled with an average functionality of 4 to 8, and the third compound (iii) is a polyether alcohol component, having a hydroxyl number of 100 to 350 mg KOH/g coupled with an average functionality of 2 to 5.

EFFECT: hard polyurethane foams produced by this method are characterised by optimum flow properties at low viscosity of the polyol component and can be used as heat-insulating material in cooling equipment, in boilers, pipelines of central heating or in construction.

20 cl, 1 tbl, 3 ex