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    31.
    发明专利
    未知

    公开(公告)号：BR0210761A

    公开(公告)日：2004-07-20

    申请号：BR0210761

    申请日：2002-07-02

    Applicant: BASF AG

    Inventor： WOSTBROCK KARL-HEINZ ,  STROEFER ECKHARD ,  WEBER MARKUS ,  KERTH STEFFEN

    IPC: C01B21/14

    Abstract: A process for preparing a salt-free aqueous hydroxylamine solution by reacting an aqueous solution of a hydroxylammonium salt with a base to give a mixture and separating from said mixture by distillation a salt-free aqueous hydroxylamine solution, involving using as a base an aqueous solution of a mixture of NaOH and KOH in a molar ratio Na + :K + in the range from 70:30 to 95:5 and with a total concentration of Na + and K + in the range from 0.1 to 10 m/m % based on the total amount of the mixture.

    METHOD FOR PRODUCING AN AQUEOUS HYDROXYLAMINE SOLUTION DEVOID OF SALT
    36.
    发明专利
    METHOD FOR PRODUCING AN AQUEOUS HYDROXYLAMINE SOLUTION DEVOID OF SALT 未知

    公开(公告)号：CA2451482A1

    公开(公告)日：2003-01-16

    申请号：CA2451482

    申请日：2002-07-02

    Applicant: BASF AG

    Inventor： WOSTBROCK KARL-HEINZ ,  STROEFER ECKHARD ,  WEBER MARKUS ,  KERTH STEFFEN

    IPC: C01B21/14

    Abstract: The invention relates to a method for producing an aqueous hydroxylamine solution that is devoid of salt by reacting an aqueous solution of a hydroxylammonium salt with a base to obtain a mixture and by separating an aqueous hydroxylamine solution devoid of salt by distillation from said mixture. The method is characterised in that an aqueous solution of a mixtur e of NaOH and KOH with a molar ratio of Na+: K+ in the region of between 70: 3 0 and 95: 5 and a total concentration of Na+ and K+ in the region of between 0 .1 and 10 m/m % (in relation to the total quantity of the mixture) is used as t he base.

    37.
    发明专利
    未知

    公开(公告)号：DE59801534D1

    公开(公告)日：2001-10-25

    申请号：DE59801534

    申请日：1998-06-18

    Applicant: BASF AG

    Inventor： WATZENBERGER OTTO ,  SCHELLING HEINER ,  PFAB PETER ,  STROEFER ECKHARD

    IPC: B01D3/00 ,  C01B21/14

    Abstract: PCT No. PCT/EP98/03714 Sec. 371 Date Dec. 8, 1999 Sec. 102(e) Date Dec. 8, 1999 PCT Filed Jun. 18, 1998 PCT Pub. No. WO98/57886 PCT Pub. Date Dec. 23, 1998A very pure aqueous solution of free hydroxylamine is prepared by a process in which the dilute, aqueous hydroxylamine solution is concentrated in a column by removing hydroxylamine-containing vapors via a side take-off in the bottom of the column, and very pure hydroxylamine is obtained by condensing the vapors. The novel process can be carried out simply, in a gentle manner and on a large scale and gives electronic grade hydroxylamine.

    38.
    发明专利
    未知

    公开(公告)号：BR9907634A

    公开(公告)日：2000-11-14

    申请号：BR9907634

    申请日：1999-01-26

    Applicant: BASF AG

    Inventor： STROEFER ECKHARD ,  JACOBS JAN ,  SEYFERT WILFRIED ,  SCHWARZ HANS VOLKMAR ,  SCHWEERS OLAF ,  SCHARR VOLKER ,  PENZEL ULRICH

    IPC: C07B61/00 ,  C07C209/78 ,  C07C211/45 ,  C07C211/50 ,  C07C263/10 ,  C07C265/14

    Abstract: The production of methylene-di-phenylamine from aniline (A) and formaldehyde (F) with an acid catalyst (C) comprises placing (A) and possibly (C) in a reactor, feeding (F) and possibly (C) through a mixer into a circulation loop containing (A), possibly (C) and possibly (F), and heating to above 75 degrees C after adding at least 50% of the total (F). Independent claims are also included for: (a) mixtures containing methylene-di-phenylamine (MDA) obtained by this process; (b) a process for the production of polyisocyanates by phosgenation of these mixtures; (c) a process for the production of methylene-diphenylisocyanate (MDI) by phosgenation of MDA (obtained as above) at 50-150 degrees C and 0.5-10 bar, optionally in presence of inert solvent; (d) a process for the production of MDI comprising: (1) the semi-continuous process described above using a mol ratio of (A):(C) = (1:0.6)-(1:0.01) and a mol ratio of (A):(total F) = (1.7:1)-(7.2:1), in which the temperature of the circulating mixture is 20-75 degrees C and the mixture is heated for at least 0.2 hour at above 75 degrees C after adding at least 50% of the (F), (2) neutralization, (3) distillation of water and aniline, (4) phosgenation of the purified MDA as in (c) above, (5) removal of phosgene, hydrogen chloride and possibly solvent at below 150 degrees C under vacuum or inert gas, (6) removal of solvent at not above 1900 degrees C and (7) isolation of 2,2'-, 2,4'- and/or 4,4'-MDI and/or mixtures of at least two of these isomers by distillation at 2-50 mbar and 150-250 degrees C and/or by crystallization; and (e) polyisocyanates obtained by these processes.

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