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    12.
    发明专利
    未知

    公开(公告)号：AT250371B

    公开(公告)日：1966-11-10

    申请号：AT278865

    申请日：1965-03-26

    Applicant: BASF AG

    Inventor： HAMPRECHT GUENTHER DR ,  FROMM HERMANN DIETER DR ,  SCHWARZMANN MATTHIAS DR ,  VOGEL LUDWIG

    IPC: C07C273/16

    Abstract: Urea is recovered from the off-gas obtained in a melamine sythesis from urea in the gas phase and in the presence of catalysts and which has been freed from melamine by fractional condensation at from 150 DEG to 200 DEG C., by bringing said off-gas into intimate contact with a melt of urea or a melt of urea and its thermal decomposition products, both of which are kept up to 50 DEG C. above their melting temperature. Thermal decomposition products which may be present in the urea melt are biuret, triuret, cyanuric acid, ammeline, ammelide, melamine or melamine cyanurate. The presence of 20-25% biuret (obtained by blowing with CO2) is preferred, since this depresses the melting point and allows a very cool melt to be used. Portions of the melt are preferably drawn off after use and passed to the melamine synthesis reactor.

    Production of emulsifiable waxes
    14.
    发明专利
    Production of emulsifiable waxes 未知

    公开(公告)号：GB959362A

    公开(公告)日：1964-06-03

    申请号：GB4742062

    申请日：1962-12-17

    Applicant: BASF AG

    Inventor： JAHRSTORFER MICHAEL ,  SCHMEIDL KARL ,  STAIGER GERHARD ,  VOGEL LUDWIG

    IPC: C08F8/06 ,  C08F8/50 ,  C09G1/08

    Abstract: Molten polyolefins having a molecular weight of between 1,000 and 50,000 are oxidized with oxygen or oxygen-containing gas under increased pressure and at a temperature between 130 DEG and 250 DEG C. until 0.5 to 25 kg of oxygen has been absorbed for each 100 kg of polyolefin and the oxidation is carried out with intense agitation with an agitator output of from 1 to 15 kilowatts per 100 kg of polyolefin. Polyolefins exemplified are polyethylene, polypropylene, and a copolymer of ethylene and carbon monoxide containing between 1 and 3 carbonyl groups per 50 ethylene groups. The materials may be made by thermally degrading high molecular weight polyolefins. The products are easily emulsifiable waxes.

    Improvements in the purification of crude dimethyl terephthalate by distillation
    15.
    发明专利
    Improvements in the purification of crude dimethyl terephthalate by distillation 未知

    公开(公告)号：GB870012A

    公开(公告)日：1961-06-07

    申请号：GB219560

    申请日：1960-01-21

    Applicant: BASF AG

    Inventor： AROYAN HARRY JAMES ,  SINN RICHARD ,  SCHERF KARL ,  VOGEL LUDWIG

    IPC: B01D9/00 ,  C07C69/82

    Abstract: Pure dimethyl terephthalate is recovered from mixtures of the ester with methanol, water and other impurities by a process in which a distillation column 1 is maintained at a pressure at which the condensation temperature of the vaporized methanol-water mixture is above the solidification temperature of the ester, i.e. at least 8 atmospheres, an overhead fraction of methanol, water and low-boiling impurities is led off by line 5 to a second, dehydrating, distillation column 10 from which pure methanol is obtained overhead by line 11 and water and impurities are drained off by line 35, the ester mixed with high-boiling impurities is led by line 9 into a third distillation column 14 maintained at atmospheric or slightly elevated pressure up to 1 atmosphere gauge, to which column methanol vapour is also fed by line 13, and the pure ester is separated from methanol after the fraction consisting of ester and methanol distilled off by line 18 is condensed. High-boiling impurities are discharged by line 16. Crude mixtures preferably contain 1.5 to 8 parts of methanol per part of ester and the water content is between 1 and 30% of the methanol content. Two columns instead of column 1 may be used. The vapours in line 18 are condensed at atmospheric or reduced pressure in a vessel 20 and the condensate is cooled further, e.g. to between 40 DEG C. and -10 DEG C., in a container 21 to crystallize the ester, which is then separated from methanol in a centrifuge 24. The ester, after washing, if desired, with methanol from line 26, is passed to a drier 28 while excess methanol is passed to a reservoir 25 for use in the esterification of terephthalic acid or for circulation to the second column 10 by line 33.

    MANUFACTURE OF TETRAHYDROFURAN
    18.
    发明专利
    MANUFACTURE OF TETRAHYDROFURAN 未知

    公开(公告)号：CA1057765A

    公开(公告)日：1979-07-03

    申请号：CA233823

    申请日：1975-08-20

    Applicant: BASF AG

    Inventor： HETZEL ECKHARD ,  WEITZ HANS-MARTIN ,  VOGEL LUDWIG ,  HARTIG JUERGEN

    IPC: B01J27/00 ,  B01J31/00 ,  C07B61/00 ,  C07D307/08

    Abstract: Tetrahydrofuran is prepared from a compound containing butanediol or capable of generating butanediol. The butanedioldonating compound is the diacetate of butanediol-1,4 which is reacted with hydrolysis and etherification by passing it downwardly through a distillation column together with an acid catalyst and passing steam upwardly therethrough. The reaction is performed at temperatures of from 80.degree. to 200.degree.C and the amount of water used is from 1.24 to 20 moles for each mole of diacetate introduced. The product which distills off is tetrahydrofuran.

    20.
    发明专利
    未知

    公开(公告)号：DE2334916A1

    公开(公告)日：1975-01-30

    申请号：DE2334916

    申请日：1973-07-10

    Applicant: BASF AG

    Inventor： VOGEL LUDWIG ,  ROTERMUND GERHARD W DR ,  HETZEL ECKHARD DIPL-ING ,  CHRISTOPH DIPL-ING DR HORN HAN

    IPC: C07D209/48 ,  D07B7/06

    Abstract: 1465756 Phthalamide BASF AG 9 July 1974 [10 July 1973] 30292/74 Heading C2C A continuous process for the preparation of phthalimide comprises reacting phthalic anhydride with ammonia at elevated temperature, washing the off-gas with a melt which contains at least 70% by weight of phthalimide, at a temperature of not less than 210‹ C., and feeding the melt to the reaction. Preferably the reaction is carried out in countercurrent and the wash column is combined with the reactor by using a tray column, the phthalic anhydride melt being fed continuously to one of the middle trays, the ammonia being introduced at the bottom of the column, and the phthalimide melt, as the wash fluid, being introduced at the top of the column.

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