发明名称 |
Procédé pour la purification du téréphtalate diméthylique brut obtenu par dépolymérisation du téréphtalate de polyéthylène. |
摘要 |
A process for the purification of crude dimethyl terephthalate which has been recovered by the depolymerisation of polyethylene terephthalate by heating the polyethylene terephthalate in the presence of methanol at a temperature of substantially 200 DEG C. and a pressure of substantially 40 atmospheres, comprises crystallising the crude ester while hot in a first stage in the presence of methanol at a temperature of from 58 DEG C. to 50 DEG C. until at least 50% of the dimethyl terephthalate contained in the crude ester has precipitated, continuing the crystallisation at a temperature of 48 DEG C. until no more. dimethyl terephthalate precipitates, separating the resulting crystal magma at a temperature of at least 27 DEG C. and immediately centrifuging the separated crystal magma. An example is furnished. |
申请公布号 |
BE583333(A1) |
申请公布日期 |
1960.02.01 |
申请号 |
BE19590583333 |
申请日期 |
1959.10.06 |
申请人 |
VEREINIGTE GLANZSTOFF-FABRIKEN A.G. |
发明人 |
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分类号 |
C07C67/03;C07C69/82;C08J11/00;(IPC1-7):C07C |
主分类号 |
C07C67/03 |
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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