Polyurethane-based thickener for aqueous composition

PROBLEM TO BE SOLVED: To prepare a polyurethane suitable as a thickener for an aqueous composition particularly to facilitate the preparation of a thickener having a thickening action at least equivalent to that of a conventional thickener under low-shear conditions by reacting a specified polyether component (hereinbelow referred to as A) with a polyisocyanate component (hereinbelow referred to as B) in a specified ratio. SOLUTION: Component A having an OH value of 10-30 mgKOH/g and obtained by alkoxylating a mixture comprising 30-80 mol.% 8-30C monofunctional alcohol or alkylphenol, 2-10 mol.% NaOH or KOH, 10-60 mol.% water and 0-10 mol.% tri- to hexa-hydric alcohol of a molecular weight of 92-600 with a mixture containing up to 20 mol.%, based on the total amount of ethylene oxide or both ethylene oxide and alkylene oxides, propylene oxide is reacted with component B containing at least one organic diisocyanate in NCO/OH equivalent ratio of 0.9:1 to 1.2:1. COPYRIGHT: (C)1996,JPO