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US 2011/0237697 A1Published application
Process for the production of polyester polyols with low volumes of dioxane waste
AssigneeBayer MaterialScience AG
InventorsHartmut Nefzger, Erika Bauer, Johannes Van de Braak, Jürgen Schlobmacher
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Abstract
The invention relates to the production and use of polyester polyols, formed from at least one carboxylic acid hydride and ethylene glycol, wherein a specialized reaction control stustantially suppresses the formation of 1,4-dioxane from diethylene glycol.
Claims15
A process for the production of a polyester polyol, comprising
- (1) mixing
- at least one carboxylic acid anhydride (A), and diethylene glycol (B), with (1) at least one C2-C4 glycol (C) and at least one aliphatic C5-C12 dicarboxylic acid (D), or (2) at least one C5-C10 glycol (E) and at least one C4 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.
2 more elements
Dependencies are inferred from the claim text.