Patents Assigned to Stamicarbon N.V.
  • Patent number: 4015946
    Abstract: A process for recovering ammonium sulphate from an aqueous ammonium sulphate solution containing organic contaminants is disclosed. The aqueous solution is contacted with an organic substance which is water soluble and which is capable, in combination with a saturated ammonium sulphate solution, of forming a two-layer system. The organic substance is selected from the group consisting of lactames of 4 to 20 carbon atoms, and mixtures thereof. The resultant two layers may be separated into an aqueous phase containing the ammonium sulphate, and an organic phase containing the organic substance and the organic contaminants. Typical organic contaminants include acrylonitrile prepared from propylene, methyl methacrylate prepared from acetone cyandihydrin, and methyl methacrylate prepared from acrylonitrile. The ammonium sulphate is readily crystallized from the aqueous phase.
    Type: Grant
    Filed: July 12, 1971
    Date of Patent: April 5, 1977
    Assignee: Stamicarbon N.V.
    Inventors: Jentje Bonnema, Henri J. H. Simon
  • Patent number: 4003928
    Abstract: A process is described for the preparation of urea at a high temperature and pressure whereby the quantity of water recycled to the urea-synthesis reactor along with the recycle ammonium carbamate may be reduced. The high pressure aqueous urea solution from the reactor is expanded into two or more ammonium carbamate decomposition stages operating at successively lower pressures. In at least one of the ammonium carbamate decomposition stages the expanded aqueous urea solution is heated in a controlled manner and a first off-gas is separated. The residual aqueous urea solution is again heated and a second off-gas is removed, which off-gas is combined with the first off-gas, condensed and recycled to the urea-synthesis reactor.
    Type: Grant
    Filed: June 24, 1974
    Date of Patent: January 18, 1977
    Assignee: Stamicarbon N.V.
    Inventor: Antonius M. A. Heunks
  • Patent number: 3987092
    Abstract: Lysine is optically resolved by forming a salt with sulphanilic acid and selectively crystallizing one of the antipodes from a supersaturated solution thereof. The salt of lysine and sulphanilic acid is a novel compound.
    Type: Grant
    Filed: October 2, 1969
    Date of Patent: October 19, 1976
    Assignee: Stamicarbon N.V.
    Inventors: Willem K. van der Linden, Geertrudes H. Suverkropp
  • Patent number: 3957913
    Abstract: Polyfunctional anionic initiators for the preparation of elastomeric block copolymers are prepared by reacting a monofunctional anionic initiator, such as secondary butyl lithium, with a monovinyl aromatic compound, such as styrene, or a conjugated diene, such as butadiene or isoprene or mixtures thereof to form a polyuric reaction product which in turn, is reacted with a polyvinyl aromatic compound, such as divinyl benzene. The cross-linked reaction product, prior to use, is reacted with styrene or another monovinyl aromatic compound. The resulting polyfunctional anionic initiators are useful in producing elastomeric block co-polymers of the A-B-(A)n type exhibiting good elastomeric properties.
    Type: Grant
    Filed: April 12, 1974
    Date of Patent: May 18, 1976
    Assignee: Stamicarbon N.V.
    Inventors: Bernard C. Roest, Herman A. J. Schepers
  • Patent number: 3937674
    Abstract: Petroleum resin comprising units of cyclopentadiene, methyl cyclopentadiene or both is reacted at 150.degree.-320.degree.C with an unsaturated fatty acid, such as tall oil fatty acid, in the presence of magnesium oxide or other metal compound for a period of time until a modified resin having a melting point of at least 125.degree.C, preferably 140.degree.-160.degree.C is obtained. The resulting resins are especially useful as binding and thickening agents for printing ink resulting in an ink that dries rapidly and is resistant to rubbing.
    Type: Grant
    Filed: September 19, 1972
    Date of Patent: February 10, 1976
    Assignee: Stamicarbon N.V.
    Inventor: Jan Laarkamp
  • Patent number: 3936430
    Abstract: Process for preparing halogenated rubbery copolymers of ethylene, at least one other .alpha.-alkene, dicyclopentadiene and optionally one or more other polyenes is disclosed, wherein the copolymer is halogenated in the substantially undissolved or solid state with molecular halogen at a temperature of between -30.degree. and +80.degree.C. The halogenated copolymers produced by the process of the present invention may be covulcanized with strongly unsaturated rubbers to yield products which have excellent physical and mechanical properties, with reduced vulcanization times. The vulcanizates are suited for numerous applications including, for instance, car tires.
    Type: Grant
    Filed: December 22, 1972
    Date of Patent: February 3, 1976
    Assignee: Stamicarbon N.V.
    Inventors: Lowhardt A. A. Schoen, Marinus J. R. Visseren, Jean G. VAN DER Sangen