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    PROCESS FOR THE PREPARATION OF PERFLUOROETHERCARBOXYLIC ACIDS
    5.
    发明专利
    PROCESS FOR THE PREPARATION OF PERFLUOROETHERCARBOXYLIC ACIDS 未知

    公开(公告)号：CA2067077A1

    公开(公告)日：1992-10-27

    申请号：CA2067077

    申请日：1992-04-24

    Applicant: HOECHST AG

    Inventor： GRIES THOMAS ,  SCHWERTFEGER WERNER ,  KOTTMANN HARIOLF ,  EBMEYER FRANK

    IPC: B01J19/18 ,  C07C51/04 ,  C07C51/44 ,  C07C59/135

    Abstract: HOE 91/F 121 Process for the preparation of perfluoroethercarboxylic acids The invention relates to a process for the preparation of perfluoroethercarboxylic acids of the formula (I) Rf-COOH from perfluoroetheracyl fluorides of the formula (II): (II) Rf-COF where Rf is equal to CmF2m+1-O-(C3F60)n-CF(CF3)-, in which m = 1 - 8 and n = O - 8, in which the acyl fluorides (II) are diluted with 0.5 to 5 times the amount by weight of a fluorinated inert solvent and the diluted mixture is then intensively mixed with 2-15 mol of water per mole of acyl fluoride and the organic phase obtained after phase separation is freed from the solvent by distillation.

    PROCESS FOR PREPARING A PARTICULARLY PURE GLYCOLIC ACID
    7.
    发明专利
    PROCESS FOR PREPARING A PARTICULARLY PURE GLYCOLIC ACID 未知

    公开(公告)号：CA2194739A1

    公开(公告)日：1997-07-11

    申请号：CA2194739

    申请日：1997-01-09

    Applicant: HOECHST AG

    Inventor： EBMEYER FRANK ,  HABERLEIN HARALD ,  MOHN HOLGER

    IPC: B01D61/44 ,  C07C51/367 ,  C07C51/42 ,  C07C59/06

    Abstract: The present invention relates to a process for preparing a particularly pure glycolic acid by saponification with chloroacetic acid with an excess of alkali metal hydroxide, with the resulting alkali metal chloride being filtered off, and the 20 to 70% strength by weight glycolic acid solution being subsequently subjected to anelectrodialysis at 20 to 40.degree.C and a cell voltage of 0.5 to 2.5 V per cell pair. The process of the invention permits optimum removal of sodium chloride and chloroacetic acid as necessary for preparing a particularly pure glycolic acid. Other organic acids, nitrogen compounds, aldehydes and salts are not produced in this process and thus do not affect the product quality.

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