Process for esterification
AssigneeMinnesota Mining and Manufacturing Company
InventorMark N. Schaeffer
Life of this patent
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Abstract
A method for the rapid esterification of dicarboxylic acids or the transesterification of lower alkyl carboxylic acid diesters with diols is disclosed. The method includes recycling of evaporated unreacted starting materials and can be carried out at elevated pressures. The resulting esterification or transesterification products can then be polymerized into polyesters, for example by a thin film polymerization method.
Claims20
A process for the esterification of dicarboxylic acids or for the transesterification of dicarboxylic lower-alkyl esters, with at least one alkylene diol having two primary alcohol functionalities, comprising the steps of
- A) adding a liquid mixture comprising said acid or ester and said diol to a substantially horizontal channel;
- B) allowing said liquid to flow through said channel such that the ratio of the width of said channel to the depth of said liquid is greater than 1.5 to 1;
- C) heating said liquid mixture to a temperature sufficiently high to initiate esterification or transesterification and to drive off reaction water or lower alkyl alcohol byproducts;
- D) removing water or lower-alkyl alcohol byproduct vapors from the channel such that such vapors have little further contact with said liquid mixture.
Dependencies are inferred from the claim text.