Patent ID: 8053607

Claim:
A method for producing a polyether-polyol having a molecular weight distribution ranging from 1.66 to 1.95, which comprises preparing a polyether-polyol (A) having a number-average molecular weight of from 500 to 4500 represented by: HO—[(CH 2 ) 4 O] n —[CH 2 CH 2 CHR 1 CH 2 O] q —H and/or HO—[(CH 2 ) 4 O] n —[(CH 2 CHR 1 CH 2 CH 2 O)] q —H wherein R 1 represents a methyl radical; n indicates a positive integer; and q indicates 0 or a positive integer, by polymerization of tetrahydrofuran or copolymerization of tetrahydrofuran with methyl-substituted tetrahydrofuran, and subjecting said polyether-polyol (A) to fractional extraction of said polyether-polyol (A) having a number-average molecular weight of from 500 to 4500 in the presence of an aqueous solution (C) containing from 30 to 50 wt % sulfuric acid based on the aqueous solution (C) at a room temperature to 100° C.