Patent ID: 8481606

Claim:
A process for the production of a polyester polyol, comprising (I) mixing at least one carboxylic acid anhydride (A), and diethylene glycol (B), with (1) at least one C 2 -C 4 glycol (C) other than diethylene glycol, and at least one aliphatic C 5 -C 12 dicarboxylic acid (D), or (2) at least one C 5 -C 10 glycol (E) and at least one C 4 dicarboxylic acid (F), wherein the molar ratio of component (B) to (A) is in the range 1.5:1-1.1:1, and the proportion by weight of components (A) and (B), based on the weight of all the components of the mixture, is in the range 66-95 wt. %, and (2) reacting the mixture to form a polyester polyol.