| 摘要 |
<p>Preparation of terephthalic acid from the oxidation product obtained accrding to GE 1,041,945. The oxidation product is after-treated for the working up thereof to free terephthalic acid by raising the temperature and eventually under pressure, as in NE 66,09738, in the presence of p-xylene, water, or acetic acid, which can be added as a mixture. In particular the treatment temperature is 210-280 deg.C and the reaction time of between the minimum time necessary for heating to the above temperature, and 5 hrs. The reagents may be added continuously. High purity product suitable for prodn. of alkyd resins or polyester fibre of film.</p> |
