Claims
- 1. A process for producing terephthalic acid of high purity suitable for direct polymerization by oxidizing p-tolualdehyde at 180.degree.-280.degree. C. with a gas containing molecular oxygen in a solvent consisting of water in the presence of bromine ions, the concentration of the bromine ions being 0.5-12% by weight on the basis of the solvent, in a reactor using zirconium or a zirconium alloy as a reactor material.
- 2. A process according to claim 1, wherein the oxidation reaction is conducted in the presence of 0.5-6% by weight of the bromine ions on the basis of the solvent.
- 3. A process according to claim 2, wherein the oxidation reaction is conducted in the presence of 1-4% by weight of the bromine ions on the basis of the solvent.
- 4. A process according to claim 1, wherein the oxidation reaction is conducted at 210.degree.-260.degree. C.
- 5. A process according to claim 1, wherein the oxidation reaction is carried out under a pressure of 10-50 kg/cm.sup.2 gauge.
- 6. A process according to claim 1, wherein the oxidation reaction is conducted with air.
- 7. A process according to claim 1, wherein the oxidation reaction is conducted in the water in an amount of at least twice the weight of p-tolualdehyde.
- 8. A process according to claim 7, wherein the amount of water is 3-6 times the weight of p-tolualdehyde.
- 9. A process according to claim 1, wherein the oxidation reaction is conducted batchwise, semi-continuously or continuously.
- 10. In a process for producing terephthalic acid by oxidizing p-tolualdehyde in a liquid phase with a gas containing molecular oxygen in the presence of bromine ions at an elevated temperature and under a pressure of 10-50 kg/cm.sup.2 gauge, the improvement comprising conducting the oxidation in water as solvent at 180.degree.-280.degree. C. in a reactor having a zirconium or zirconium alloy inner surface.
- 11. The process of claim 1 in which the p-tolualdehyde is oxidized in the presence of compounds of heavy metals selected from the group consisting of manganese and cerium.
- 12. The process of claim 10 in which the reactor has a zirconium or zirconium alloy lining and said lining is 0.5-6 mm thick.
- 13. The process of any one of claims 1 or 10 in which the zirconium alloy is zircaloy.
Priority Claims (1)
Number |
Date |
Country |
Kind |
53-17649 |
Feb 1978 |
JPX |
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Parent Case Info
This is a continuation, of application Ser. No. 9,963, filed Feb. 6, 1979 now abandoned.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
3012038 |
O'Neill et al. |
Dec 1961 |
|
3708531 |
Croce et al. |
Jan 1973 |
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Continuations (1)
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Number |
Date |
Country |
Parent |
9963 |
Feb 1979 |
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