The present invention is a urethane-type polymer obtained by a reaction of: a monohydroxy compound (A) represented by Formula (1), wherein R 1 is an aliphatic hydrocarbon group having 24 to 36 carbon atoms, and m represents a number ranging from 0 to 1000 a polyethylene glycol (B) represented by Formula (2), wherein n represents a number ranging from 2 to 1000 a monoglyceryl ether compound (C) represented by Formula (3), wherein R 2 represents an aliphatic hydrocarbon group having 5 to 12 carbon atoms and an isocyanate compound (D) represented by Formula (4), €ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒR 3 �NCO] q €ƒ€ƒ€ƒ€ƒ€ƒ(4) wherein R 3 represents a hydrocarbon group having 4 to 13 carbon atoms, and q represents the number 2 or 3. This urethane-type polymer can be used as a urethane-type viscosity modifier excellent in long-term storage stability, similarly to alkali thickening-type viscosity modifiers, while having characteristics similar to those of existing urethane-type viscosity modifiers.
