Patent ID: 9676897
Date: 2017-06-13
CPC Classifications: C08G,C08J

Claim:
1. A process for producing a polyether polyol, the process comprising: subjecting a propylene oxide to ring-opening addition polymerization with respect to an initiator having an average number of hydroxyl groups of from 2 to 8, in the presence of a double metal cyanide complex catalyst in a form of slurry, to obtain an intermediate polyol; and subjecting ethylene oxide to ring-opening addition polymerization with respect to the intermediate polyol in the presence of an alkali metal hydroxide as a polymerization catalyst, to obtain a polyether polyol (A1) having a hydroxyl value of from 5 to 24 mgKOH/g, wherein the polyether polyol (A1) comprises a terminal ethylene oxide addition in molar amount of from 19.1 to 23 mol per mol of the initiator provided in the ring-opening addition polymerization of the propylene oxide, wherein no alkylene oxides other than propylene oxide are added in the presence of the double metal cyanide complex catalyst before subjecting ethylene oxide to ring-opening addition polymerization with respect to the intermediate polyol, and wherein the intermediate polyol is obtained by: supplying and reacting a part of the propylene oxide in a reaction fluid comprising the initiator and the double metal cyanide complex catalyst, wherein the maximum temperature of the reaction fluid reached during the reaction of the part of the propylene oxide is higher by from 15 to 50° C. than the initial temperature of the reaction fluid immediately before supplying the part of propylene oxide; and supplying the remaining part of the propylene oxide after the reaction of the part of the propylene oxide, and carrying out ring-opening addition polymerization in the presence of the double metal cyanide complex catalyst.