Preparation of polyester copolymers
AssigneeE. I. Du Pont de Nemours and Company
InventorEdward B. Jones
Life of this patent
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Abstract
Preparation of polyester resins from dimethylterephthalate by forming bis(2-hydroxyethyl) terephthalate, and using a portion of this product as solvent for one or more dicarboxylic acids and one or more dihydric alcohols, reacting the acids and alcohols, and combining the portions, and polymerizing the mixture.
Claims3
A continuous process for the preparation of high molecular weight polyester resin which comprises forming a stream containing bis(2-hydroxyethyl) terephthalate by the ester interchange reaction of dimethylterephthalate with ethylene glycol, separating a portion of the stream, into the separated portion adding isophthalic acid and ethylene glycol in about a 2/1 mole ratio of ethylene glycol to isophthalic acid and reacting said isophthalic acid and said ethylene glycol in the separated portion to form the corresponding bis ester and water, removing the water, and them combining the separated portion now containing the newly formed bis ester with the stream from which it was separated, and then polycondensing the bis compounds in the stream to form high molecular weight polyester.
Dependencies are inferred from the claim text.