中科微点-全球专利检索

  1. Login
  2. Sign Up

Search Results

1496 records (took 0.022 seconds)

    232.
    发明专利
    未知

    公开(公告)号：DE1620476C3

    公开(公告)日：1974-11-14

    申请号：DE1620476

    申请日：1965-07-28

    Applicant: STAMICARBON B.V., HEERLEN (NIEDERLANDE)

    Inventor： VERSTRIJDEN, ULRICH, GELEEN ,  DEUMENS, JOHANNES JOZEF MARIA, NUTH

    IPC: C07B43/02 ,  C07D41/00

    Abstract: The invention relates to a process for preparing 3 - nitro - aza cycloheptane - 2 - N - carbochloride by reacting 2-chloro-aza cyclo-2,3-heptene-N-carbochloride with a nitrating acid preferably a mixture of nitric acid and sulphur trioxide in substantially equi-molecular proportions, in liquid sulphur dioxide at a temperature below 30 DEG C. and hydrolysing the reaction product at a temperature below 50 DEG C. The hydrolysis of the reaction product is preferably carried out in the presence of a water-miscible organic solvent for the aza-cycloheptane compound such as nitro benzene.

    235.
    发明专利
    未知

    公开(公告)号：DE1520941B2

    公开(公告)日：1974-05-30

    申请号：DE1520941

    申请日：1960-06-07

    Applicant: STAMICARBON B.V., GELEEN (NIEDERLANDE)

    Inventor： BERG, CORNELIS EMILE PETRUS VALERIUS VAN DEN ,  HENDRIKS, HENDRIK ,  MUYTJENS, MATHIAS JOSEPHUS GERARDUS

    IPC: B01D11/04 ,  B01J19/28 ,  B08B3/12 ,  C07F9/165 ,  C08F6/24 ,  C08F1/88

    Abstract: Removing catalyst residues from a synthetic polymeric material by a process which comprises continuously passing impure polymeric material with a liquid (1) upwards within a column provided with internal obstructions, and continuously passing a liquid (2), heavier than liquid (1) and at least not completely miscible with (1), downwards within the column, at such a rate that liquid (1) forms a continuous phase in the column, and imparting to the liquids in the column flow pulses at substantially regular time intervals, e.g. by a pump, and continuously withdrawing purified polymeric material together with liquid (1), from the top section of the column, and liquid substantially free of polymeric material from the bottom section of the column. Liquid (1), may be the polymerization medium and it may contain the impure polymer as a dispersion, emulsion, or a solution. Before the polymer and liquid (1) is supplied to the base of the column, it may be treated with an alcohol such as water-free methanol, ethanol, isopropyl alcohol, or butanol, to which a small amount of an acid, or base, may be added. The liquid (2), may be water, water containing 96-70% by volume of methanol, or an alcohol thickened by a polar substance such as urea, sulphuric acid, sodium hydroxide, sodium acetate, acetic acid, ethylene glycol, or glycerol. A wetting agent may be present in liquids (1) or (2). The process may be carried out using two columns in series. In the examples the catalyst residues removed are of the Ziegler-type. The polymers purified may be homo- and copolymers of ethylene, propylene, 1-butene, isobutene, styrene, butadiene, isoprene, or chloroprene.

    PROCESS FOR PREPARING UREA
    239.
    发明专利
    PROCESS FOR PREPARING UREA 未知

    公开(公告)号：ZA878215B

    公开(公告)日：1988-04-28

    申请号：ZA878215

    申请日：1987-11-02

    Applicant: STAMICARBON B.V.

    Inventor： KEES JONCKERS ,  HENK CHRISTIAAN BURKS

    IPC: C07C67/00 ,  C07C239/00 ,  C07C273/04 ,  C07C

    Abstract: Process for preparing urea in which, - at a pressure of 125-350 bar and the corresponding temperature, a urea synthesis solution containing carbamate is formed from carbon dioxide and an excess of ammonia, - in a first decomposition step part of the carbamate is decomposed, with supply of heat and in countercurrent contact with a stripping gas, and the resulting gas phase is in part condensed in a first con-densation zone, - in at least two further decomposition steps a further part of the carbamate still present is decomposed and the gas mixture formed is separated off, in the first of the further decomposition steps a pressure of 4-40 bar being maintained, - the remaining urea-containing solution is processed by evaporation to form a concentrated urea solution, the heat required for evaporation being obtained at least in part by condensation of the gas mixture obtained in the first of the further decomposition steps. The gas mixture used in the first evaporation step is formed by the gas phase resulting from the heat exchange between the part of the stripped urea synthesis solution expanded to a pressure of 4-40 bar and the condensing gas mixture in the first condensation zone.

Patent Agency Ranking