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A process of production of technical pure (>95%) carbazole from coal tar. Anthracene mud (obtained from anthracene oil fraction) of coal tar is a rich resource of carbazole. The process effectively isolates the carbazole from such anthracene mud and basically involves vacuum distillation of the mud to obtain therefrom a fraction rich in anthracene-carbazole, digesting the said fraction in benzene to provide an Anthracene-Carbazole (AC) residue rich in carbazole, subjecting the residue to formaline treatment to obtain therefrom the carbazole as filtrate and treating the filtrate containing carbazole to isolate the substantially pure carbazole. The process produces substantially pure carbazole in good yield from anthracene oil fraction (anthracene mud) which would not affect isolation of anthracene from the same oil fraction. The process for manufacture is simple and cost-effective having inherent flexibility to adopt to wide variations in the raw material composition. The pure carbazole of the invention is useful for various purposes including production of tetranitro carbazole (Nitrosan), production of polyvinyl carbazole, production of hydron blue dyes, inden-cumbarone-carbazole resins and poly n-ethyl carbazole in electro-photography.
Notices, Deadlines & Correspondence
Patent Information
Applicants
STEEL AUTHORITY OF INDIA LIMITED
INDIAN INSTITUTE OF TECHNOLOGY
Inventors
1. JAYANTI VENKATA SITARAMA MURTY
2. CHATI HARSHARAJ KRISHNARAO
3. PATWARDHAN SURESH RAMCHANDRA
Specification
Documents
Application Documents
| # | Name | Date |
|---|---|---|
| 1 | 573-cal-2000-granted-specification.pdf | 2011-10-06 |
| 2 | 573-cal-2000-granted-reply to examination report.pdf | 2011-10-06 |
| 3 | 573-cal-2000-granted-pa.pdf | 2011-10-06 |
| 4 | 573-cal-2000-granted-letter patent.pdf | 2011-10-06 |
| 5 | 573-cal-2000-granted-form 3.pdf | 2011-10-06 |
| 6 | 573-cal-2000-granted-form 2.pdf | 2011-10-06 |
| 7 | 573-cal-2000-granted-form 18.pdf | 2011-10-06 |
| 8 | 573-cal-2000-granted-form 1.pdf | 2011-10-06 |
| 9 | 573-cal-2000-granted-examination report.pdf | 2011-10-06 |
| 10 | 573-cal-2000-granted-drawings.pdf | 2011-10-06 |
| 11 | 573-cal-2000-granted-description (complete).pdf | 2011-10-06 |
| 12 | 573-cal-2000-granted-correspondence.pdf | 2011-10-06 |
| 13 | 573-cal-2000-granted-claims.pdf | 2011-10-06 |
| 14 | 573-cal-2000-granted-abstract.pdf | 2011-10-06 |