Method of preparing high purity polyamic acids for use in electronic circuitry
AssigneeE. I. Du Pont de Nemours and Company
InventorYing K. Lee
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Abstract
A method of increasing the yield of a high purity polyamic acid that is the reaction product of a diamino compound and a polycarboxylic acid dianhydride, comprises: 1. purifying an inert solvent by distillation or ion-exchange; 2. purifying the dianhydride by sublimation; 3. purifying the diamino compound by a slurry process that involves the repeated washing of the diamino compound first with deionized water and then methanol; and 4. reacting the purified diamino compound with the purified dianhydride in the purified inert solvent.
Claims1
A method of increasing the yield of a high purity polyamic acid that is the reaction product of a diamino compound and a polycarboxylic acid dianhydride, comprising:
- a. purifying an inert solvent by distillation or ion-exchange;
- b. purifying the dianhydride by sublimation;
- c. purifying the diamino compound by a slurry process that involves the repeated washing of the diamino compound first with deionized water and then methanol;
- and
- d. reacting the purified diamino compound with the purified dianhydride in the purified inert solvent.
Dependencies are inferred from the claim text.