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    81.
    发明专利
    未知

    公开(公告)号：DE3301717A1

    公开(公告)日：1984-07-26

    申请号：DE3301717

    申请日：1983-01-20

    Applicant: BASF AG

    Inventor： DOCKNER TONI DR ,  KEMPE UWE DR ,  FRANK ANTON

    IPC: C07D233/90

    Abstract: Imidazole-4,5-dicarboxylic acid is prepared by a process in which imidazole is reacted with formaldehyde, and the reaction mixture is treated with nitric acid.

    84.
    发明专利
    未知

    公开(公告)号：DE2232352A1

    公开(公告)日：1974-01-17

    申请号：DE2232352

    申请日：1972-07-01

    Applicant: BASF AG

    Inventor： SPAENIG HERMANN DR ,  DOCKNER TONI DR ,  KARN HELMUT

    IPC: C07C51/42 ,  C07C59/153 ,  C07C59/30

    Abstract: A process for the recovery of glyoxylic acid as a byproduct in the synthesis of glyoxal by elution of the ion exchanger used for purifying the glyoxal and crystallization of sodium glyoxylate at a pH of from 3 to 6 from the aqueous eluate.

    88.
    发明专利
    未知

    公开(公告)号：DE59602043D1

    公开(公告)日：1999-07-08

    申请号：DE59602043

    申请日：1996-03-16

    Applicant: BASF AG

    Inventor： DOCKNER TONI DR ,  EXNER HERBERT DR ,  BAUR KARL GERHARD DR ,  POTTHOFF CHRISTIANE

    IPC: C07C67/08 ,  C07C69/54

    Abstract: A continuous prepn. process for (meth)acrylic acid alkyl esters in a homogeneous, liq., organic solvent-free phase, comprises the following steps : (1) a 1-8C monovalent alcohol and (meth)acrylic acid are reacted in a mol. ratio of 1-2:1 at high temp. in the presence of sulphuric acid or an organic sulphonic acid catalyst, with the acid, alkanol and catalyst all being continuously supplied to a reactor ; (2) following several hours reaction time the azeotrope consisting of a (meth)acrylic acid alkyl ester and water or water / alkanol starting material is passed out of the top of the reactor where the pressure is 0.1-1 atmos. and sepd. in a rectification zone ; (3) the distillate is sepd. into at least one organic phase contg. the ester and at least one aq. phase ; (4) some of the organic phase is returned to the rectification zone and opt. water is returned to the reactor ; (5) the excess alkyl ester is sepd. from the organic phase by known methods ; and (6) some of the reaction mixt. is continuously removed from the reactor. The reaction temp. is 100-150 degrees C, the dwell time is 1-6 h and the reaction mixt. contains 5-20 wt.% acid catalyst.

    90.
    发明专利
    未知

    公开(公告)号：DE19604253A1

    公开(公告)日：1997-08-07

    申请号：DE19604253

    申请日：1996-02-06

    Applicant: BASF AG

    Inventor： SCHMIDT WILLI ,  GEISENDOERFER MATTHIAS DR ,  DOCKNER TONI DR ,  HERBST HOLGER DR ,  NESTLER GERHARD DR ,  WECK ALEXANDER DIPL ING

    IPC: C07B61/00 ,  C07C67/08 ,  C07C67/54 ,  C07C69/54 ,  B01J31/02

    Abstract: In the continuous production of alkyl (meth)acrylates (AA) by reacting (meth)acrylic acid with 1-8 carbon (C) monohydric alkanols in homogeneous liquid phase, free from solvent, at elevated temperature and in the presence of an acid esterification catalyst; (a) (meth)acrylic acid, alkanol and catalyst are fed to a reaction zone; (b) during a residence time, the water formed is separated in a rectification unit (RU) III above the reaction zone; (c) the aqueous distillate is separated into an organic phase containing the alkanol and an aqueous phase; (d) the organic phase is recycled to RU III; and (e) the reaction mixture is discharged from the reaction zone and passed to another RU, where AA is separated by distillation. The novel features are that: (i) the molar ratio of (meth)acrylic acid and alkanol is 1:(0.75-2); (ii) the aqueous phase from RU III is partly recycled to RU III; (iii) the reaction mixture is passed to RU I, in which it is separated into a product (II) containing the catalyst and a product (I) containing AA, residual alkanol and residual (meth)acrylic acid; and (iv) (I) is passed to RU II, in which AA is separated from residual alkanol and residual (meth)acrylic acid and the alkanol and acid are recycled to the reaction zone. Preferably the alkanol is 2-ethylhexanol. The catalyst is para-toluenesulphonic acid (p-TSA) and/or other organic sulphonic acids, e.g. methane-, benzene- or dodecylbenzene-sulphonic acid, and/or sulphuric acid (H2SO4). The catalyst concentration in the reaction mixture is 0.1-10, especially 0.1-6 wt.% p-TSA in the reaction zone and 2.5-50 wt.% p-TSA in the sump or an equimolar amount of organic sulphonic acid and/or H2SO4. The reaction zone consists of a cascade of NOTLESS 2, especially 2-4 consecutive sections, especially reactors with circulating vapourisers. All rectification units are rectification columns.

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