Process for purifying terephthalic acid containing 4-carboxybenzaldehyde as an impurity
    5.
    发明授权
    Process for purifying terephthalic acid containing 4-carboxybenzaldehyde as an impurity 失效
    用于将含有4-羧基苯甲醛的三癸酸用于纯化的方法

    公开(公告)号:US3658894A

    公开(公告)日:1972-04-25

    申请号:US3658894D

    申请日:1968-10-02

    CPC classification number: C07C51/487 C07C63/26

    Abstract: A PROCESS FOR PURIFYING TEREPHTHALIC ACID BY REDUCING ITS 4-CARBOXYBENZALDEHYDE CONTENT TO BELOW A PREDETERMINED LEVEL, E.G., 100 P.P.M. OR LESS, TO PROVIDE A PRODUCT SUITABLE FOR USE IN APPLICATIONS SUCH AS FORMING SYNTHETIC FIBERS COMPRISING RAISING SOLID, IMPURE TEREPHTHALIC ACID TO A TEMPERATURE SUFFICIENT TO CAUSE SUBLIMATION, E.G., 235* C. TO 285*C. IN A REACTION ZONE, PASSING A GAS CONTAINING MOLECULAR OXYGEN THROUGH THE REACTION ZONE TO OXIDIZE THE 4-CARBOXYBENZALDEHYUDE TO TEREPHTHALIC ACID AND THEREAFTER RECOVERING THE SUBLIMATED TEREPHTHALIC ACID. TO REDUCE FORMATION OF UNDESIRABLE SIDE-PRODUCTS FORM THE TEREPHTHALIC ACID, THE OXYGEN-CONTAINING AS MAY CONTAIN WATER VAPOR.

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