| 发明名称 |
THIN FILM HEATING FOR THE PRELIMINARY PURIFICATION OF CRUDE PHTHALIC ANHYDRIDE |
| 摘要 |
In the preliminary purification (prior to distillation) of crude phthalic anhydride produced from xylene, the pretreatment is improved by heating a thin film of molten phthalic anhydride to 200-280 DEG C. during the course of not more than 60 seconds, said film having a thickness of not more than 2 mm.
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| 申请公布号 |
US3650906(A) |
申请公布日期 |
1972.03.21 |
| 申请号 |
USD3650906 |
申请日期 |
1969.04.14 |
| 申请人 |
CHEMIEBAU DR. A. ZIEREN GMBH. & CO. KG. |
发明人 |
HUBERT GEHRKEN;GERD HELMS;GERHARD KEUNECKE;HERBERT KRIMPHOVE |
| 分类号 |
C07C51/573;(IPC1-7):B01D1/22;B01D3/00 |
主分类号 |
C07C51/573 |
| 代理机构 |
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