发明名称 |
PROCESS FOR PREPARING PYROMELLITIC DIANHYDRIDE |
摘要 |
The invention relates to a process for preparing pyromellitic dianhydride (PMDA) by heterogeneously catalyzed oxidation in the gas phase by means of a gas containing molecular oxygen. The process involves oxidizing benzaldehydes which are 2,4,5-trialkylated by Cl- to C3-alkyl groups or mixtures of benzaldehydes which are 2,4,5trialkylated by Cl- to C3-alkyl groups and benzenes which are 1,2,4,5-tetraalkylated by Cl- to C3-alkyl groups in the presence of a catalyst. The catalyst contains as active components 5% to 95% by weight of one or more transition-metal oxides of sub-group IV of the Periodic Table of the Elements, from 1% to 50% by weight of one or more transition-metal oxides of sub-group V of the Periodic Table of the Elements. The catalyst also contains from 0% to 10% by weight of one or more oxides of elements of main group I of the Periodic Table of the Elements and/or from 0% to 50% by weight of one or more oxides of elements of main groups III, IV and V of the Periodic Table of the Elements and of elements of sub-groups VI and VII of the Periodic Table of the Elements. The indicated percentages by weight are based in each case on the total weight of the active components and add to 100% by weight.
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申请公布号 |
CA2112140(C) |
申请公布日期 |
1998.09.15 |
申请号 |
CA19932112140 |
申请日期 |
1993.12.22 |
申请人 |
CONSORTIUM FUER ELEKTROCHEMISCHE INDUSTRIE GMBH |
发明人 |
WAGNER, WERNER;MUELLER, FRANK;EBERLE, HANS-JUERGEN;GRUNDEI, FRANZ |
分类号 |
B01J27/14;B01J23/20;B01J23/22;B01J27/198;C07B61/00;C07C51/265;C07D493/04;(IPC1-7):C07D493/04;B01J21/06 |
主分类号 |
B01J27/14 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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