Continuous preparation of low unsaturation polyoxyalkylene polyether polyols with continuous additon of starter

A continuous process for the preparation of a polyoxyalkylene polyether product by DMC-catalyzed polyoxyalkylation, comprising:

• a) introducing into a reactor a DMC catalyst/starter mixture;
• b) continuously introducing alkylene oxide into said reactor;
• c) continuously introducing continuously added starter into said reactor, wherein said starter contained in said DMC catalyst/starter mixture and said continuously added starter may be the same or different;
• and
• d) continuously withdrawing a polyoxyalkylene polyether product having a number average molecular weight of N Daltons where N is from about 500 to about 50,000;
• wherein the continuous build ratio of said continuous process is greater than 0.70.

A continuous process for the DMC catalyzed preparation of polyoxyalkylene polyethers, comprising:

• a) introducing into a continuous reactor an effective polyoxyalkylation catalyzing amount of at least one DMC catalyst;
• b) continuously introducing into said reactor one or more alkylene oxides;
• c) continuously introducing into said reactor further DMC catalyst;
• d) continuously introducing into said reactor one or more continuously added starter molecules, said continuously added starter molecules having an average molecular weight of from about 18 Da to 45,000 Da, such that a concentration of continuously added starter molecules is maintained for about 50 percent or more of the average residence time of said reactor;
• e) continuously withdrawing a polyoxyalkylene polyether product having an equivalent weight in excess of 1000 Da.

A continuous process for the preparation of a polyoxyalkylene polymer or copolymer of a number average molecular weight N, comprising establishing oxyalkylation conditions in a continuous reactor containing DMC catalyst;

• continuously adding alkylene oxide;
• continually adding further DMC catalyst in an amount sufficient to maintain oxyalkylation conditions;
• continuously adding continuously added starter having a molecular weight less than said number average molecular weight such that a concentration of said continuously added starter and/or a concentration of an oxyalkylated continuously added starter having a molecular weight less than said number average molecular weight N is maintained during a substantial portion of said oxyalkylation;
• and continuously withdrawing a polyoxyalkylene product of said number average molecular weight N.

A continuous process for the preparation of a polyoxyalkylene polyether product having a number average molecular weight N, employing continuous addition of starter, comprising:

• a) establishing in a continuous reactor a first portion of a differential oxyalkylation catalyst/initial starter mixture effective to initiate polyoxyalkylation of said initial starter after introduction of alkylene oxide into said continuous reactor;
• b) continuously introducing into said continuous reactor one or more alkylene oxides;
• c) continuously introducing into said continuous reactor one or more continuously added starters which may be the same or different than said initial starter;
• d) continuously introducing into said reactor further differential oxyalkylation catalyst/further starter mixture such that the catalytic activity is maintained;
• e) polyoxyalkylating combined starters by continuously practicing at least steps b) through d) herein until a polyoxyalkylene polyether product of number average molecular weight N is obtained;
• and
• f) continuously removing said polyoxyalkylene polyether product from said continuous reactor.

A continuous process for the DMC catalyzed preparation of polyoxyalkylene polyethers, comprising:

• a) introducing into a continuous reactor an effective polyoxyalkylation catalyzing amount of at least one DMC catalyst;
• b) continuously introducing into said reactor one or more alkylene oxides;
• c) continuously introducing into said reactor further DMC catalyst;
• d) continuously introducing into said reactor one or more continuously added starter molecules, said continuously added starter molecules having an average molecular weight of from about 18 Da to 45,000 Da, such that a concentration of continuously added starter molecules is maintained for a portion of the average residence time of said reactor such that the proportion of high molecular weight tail is reduced as compared to the amount of high molecular weight tail contained in a polyol of the same composition and molecular weight prepared in a batch process where all starter is added at once;
• and
• e) continuously withdrawing a polyoxyalkylene polyether product having an equivalent weight in excess of 1000 Da.