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US 4,230,892 AGranted
Alcoholysis process for preparing poly-(tetramethylene ether) glycol
AssigneeE. I. Du Pont de Nemours and Company
InventorGerfried Pruckmayr
Life of this patent
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Abstract
Poly(tetramethylene ether) ester is converted to poly(tetramethylene ether) glycol by alcoholysis using as a catalyst an oxide, hydroxide or alkoxide of calcium, strontium, barium or magnesium.
Claims7
A process for converting a poly(tetramethylene ether) diester to PTMEG, the process comprising
- (A) preparing a mixture of
- (1) a poly(tetramethylene ether) diester having a pH of about 7,
- (2) an alkanol of 1-4 carbon atoms, and
- (3) 1-25 mol percent, based on the diester, of a catalyst which is an oxide or hydroxide of calcium, strontium or barium;
- (B) bringing the mixture to its boiling point and holding it there while the vapors of the alkanol/alkyl ester azeotrope which form are continuously removed from the reaction zone, until conversion is substantially complete;
- and then
- (C) removing the catalyst, and optionally the residual alkanol and residual alkyl ester, from the reaction mass.
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A process for converting PTMEA to PTMEG, the process comprising
- (A) preparing a mixture of
- (1) 20-60%, by the total weight of PTMEA and methanol, of PTMEA having a pH of about 7,
- (2) 40-80%, by the total weight of PTMEA and methanol, of methanol, and
- (3) 8-20 mol percent, based on the PTMEA, of calcium oxide;
- (B) bringing the mixture to its boiling point and holding it there while the vapors of the methanol/methyl acetate azeotrope which form are continuously removed from the reaction zone, until conversion is substantially complete;
- and then
- (C) removing the calcium oxide, residual methanol and residual methyl acetate from the reaction mass.
4 more elements
Dependencies are inferred from the claim text.