Abstract: It is known to polymerize olefins using transition metal complexes and/or compounds. There is an ongoing search for catalysts for olefin polymerization which do not rely on transition metals as the active center. The present invention provides novel aluminum phosphinimine complexes which are useful in the polymerization of olefins.
Type:
Grant
Filed:
August 17, 1999
Date of Patent:
May 22, 2001
Assignee:
The Governors of the University of Alberta
Inventors:
Ronald G. Cavell, Qinyan Wang, Ruppa P. Kamalesh Babu, Aparna Kasani
Abstract: A process for the separation and recovery of methyl tertiary butyl ether from mixed C4/C5 streams, such as resulting from the co-production of methyl tertiary butyl ether and tertiary amyl methyl ether from the reaction of methanol with isobutene and isoamylenes in a mixed C4/C5 stream. In a distillation column reactor the reaction is carried out concurrently with distillation of the products from the unreacted materials. In the distillation little or no MTBE is carried overhead with the unreacted C4's, C5's and methanol by controlling the methanol concentration in said column to maintain substantially a methanol/C5 azeotrope in the overheads.
Type:
Grant
Filed:
June 9, 2000
Date of Patent:
May 15, 2001
Assignee:
Catalytic Distillation Technologies
Inventors:
Lawrence A. Smith, Jr., Henry J. Semerak, Willibrord A. Groten
Abstract: A process for treating a full boiling range naphtha is disclosed in which the mercaptans and diolefins are removed simultaneously in a debutanizer distillation column reactor. The mercaptans are reacted with the diolefins to form sulfides which are higher boiling than the C4 and lighter portion of the naphtha which is taken as overheads. The higher boiling sulfides are removed as bottoms along with any C5 and heavier materials. The bottoms are preferably taken to a splitter where a portion is taken as overheads and a heavier portion is recovered with the sulfides. This reduced volume of naphtha may be hydrogenated to convert the sulfides to H2S and diolefins, which may be hydrogenated to olefins and alkanes.
Abstract: A medium pressure process for the solution polymerization of ethylene at a temperature of from 80° C. to 250° C. in the presence of a catalyst system comprising (1) a catalyst component which is a group 4 metal complex having a delocalized, cyclic, pi-bonded ligand, a (defined, specific) heteroligand and one or two activatable ligands; and (2) an ionic activator which does not contain an active proton. The catalyst component is unbridged and easily synthesized. It is highly active in solution polymerization when properly activated (but is not active when used in combination with an alumoxane). Preferred catalyst systems contain an unbridged monocyclopentadienyl titanium (IV) complex and triphenylcarbenium tetrakis (pentafluorophenyl) borate.
Type:
Grant
Filed:
January 13, 1999
Date of Patent:
April 24, 2001
Assignee:
Nova Chemical (International) S.A
Inventors:
Xiaoliang Gao, Qinyan Wang, Rupert Edward von Haken Spence, Stephen John Brown, Peter Zoricak
Abstract: Devolatilization of molten polymer is carried out using a vertical static mixer which opens directly into a flash tank. Expansion of a stripping agent injected at an inlet of the static mixer occurs in the static mixer and the continued shearing causes disengagement of the vapor from the polymer, so that expansion is complete before the polymer enters the flash tank and stripper and volatiles are removed by a pump and condenser arrangement which holds the flash tank at a reduced pressure. Polymer outlets are in the floor of the flash tank and have metering pumps at their bottom end.
Abstract: The impurity content, e.g. propionitrile, in a fraction containing C5 or C6 tertiary olefins obtained by cracking hydrocarbons is reduced by distilling with an alkanol and removing the impurity as a higher boiling point fraction.
Abstract: The present invention provides a tethered bridged metallocene compound in which the tether typically comprises a segment of the formula —(R2)d—(CH2CH2)e(CH═CH)f wherein R2 is an alkylene or phenylene group, and d, e and f are 1 or 0. One end of the tether reacts with a silane bridged metallocene compound and the other reacts with the support. The activated metallocene compound is capable of producing a polymer having a narrow molecular weight distribution.
Abstract: A process for the production of cyclohexane by the hydrogenation of benzene is provided wherein the reactor is operated at a pressure wherein the reaction mixture is boiling under low hydrogen partial pressure in the range of about 0.1 psia to less than 200 psia at 0 to 350 psig overhead pressure. The catalyst is provided as a catalytic distillation structure such that the reaction is concurrently occurring with a distillation. The benzene is fed at a point above the bed and the hydrogen is fed below the bed. All of the overheads may be returned as reflux to provide cooling within the catalyst bed.
Abstract: An improved silver catalyst for the oxidation of ethylene with molecular oxygen is made by impregnating a porous support with a silver salt of an acid; subjecting the impregnated support to a multi-stage activation in an atmosphere containing less oxygen than air by heating at a first temperature in the range of 150 to 200° C. for less than an hour, heating at a second temperature in the range of from greater than 200° C. to 300° C. for less than one hour, heating at a third temperature in the range of from greater than 300° C. to 400° C. for less than one hour and finally heating at a fourth temperature in the range of from greater than 400° C. to 500° C.; and post impregnating the support with an alkali metal, preferably cesium, from an anhydrous alcohol solution followed by washing with alcohol solvent and rapid drying to produce a finished catalyst having from 1-6×10−3 gew of the alkali metal per kg of catalyst.
Abstract: A particulate deactivator is used to pacify halogen-containing catalyst residues from a medium pressure solution polymerization process. The deactivator is added post-reactor preferably in the form of a suspension. The particulate deactivator may also be used in conjunction with a secondary, soluble deactivator.
Type:
Grant
Filed:
December 12, 1998
Date of Patent:
January 30, 2001
Assignee:
NOVA Chemicals (International) S.A.
Inventors:
Fazle Sibtain, Antonio Pietro Nicola, Stephen John Brown, Linda Jean Santry
Abstract: A diaphragm/spring operated pressure relief valve having a sensing passage of substantially the same flow area as the outlet orifice of the valve whereby failure of either diaphragm results in “fail open” configuration with the addition of a sensing inlet shroud located to capture the total pressure at the inlet and channel it to the sensing chamber to allow the valve to relieve full rated capacity in the event the sensing diaphragm is ruptured.
Abstract: A process for the selective hydrogenation of the diolefins and acetylenic compounds in a olefin rich aliphatic hydrocarbon streams is disclosed wherein the selective hydrogenation is carried out at 40 to 300° F. under low hydrogen partial pressure in the range of about 0.1 psi to less than 70 psia at 0 to 350 psig in a distillation column reactor containing a hydrogenation catalyst which serves as a component of a distillation structure, such as supported PdO encased in tubular wire mesh. Essentially no hydrogenation of the olefins occurs.
Type:
Grant
Filed:
November 25, 1997
Date of Patent:
January 2, 2001
Assignee:
Catalytic Distillation Technologies
Inventors:
Dennis Hearn, Robert P. Arganbright, Edward M. Jones, Jr., Lawrence A. Smith, Jr., Gary R. Gildert
Abstract: The melt of polyvinyl aromatic polymers comprising from 10 to 45 weight % of star branched polymer prepared using a combination of thermal and tetra functional peroxide initiation has an improved melt strength permitting better foam formation for extrusion foam blown with conventional blowing agents and inert gases including CO.sub.2.
Abstract: It is desirable to reduce the amount of volatile organic blowing agent in expandable polystyrene. This may be accomplished by partially polymerizing a mass of styrene and incorporating therein water together with an emulsifier. The partially polymerized mass is then polymerized to a high conversion using conventional suspension techniques. The polymer beads containing water which acts as a blowing agent are recovered.
Type:
Grant
Filed:
December 30, 1998
Date of Patent:
December 12, 2000
Assignee:
Nova Chemicals (International) S.A.
Inventors:
Jeroen Joost Crevecoeur, Eric Wilhelmus Johannes Frederik Neijman, Laurentius Nicolaas Ida Hubertus Nelissen, Johannes Maria Zijderveld
Abstract: The present invention relates to compatibilizers useful to laminate a layer of a vinyl aromatic polymer such as polystyrene and a polyester such as PET. The compatibilizer comprises a mixture comprising 5-95 weight % of a polyester, 95-5 weight % of an impact modified polymer of a vinyl aromatic monomer such as high impact polystyrene (HIPS) and from 5 to 20 weight % of a hydrogenated block polymer of a vinyl aromatic monomer and a conjugated diolefin sometimes called SEBS.
Abstract: A wood coring bit having a base, a central guide shaft, a sleeve extending along the guide shaft, a pair of scribing teeth on the surface of the sleeve adjacent to the work piece, which scores a track into the work piece as the bit rotates and raker tooth on the surface of the sleeve adjacent of the work piece which is aligned to follow in the track scored by the scribing teeth and to cut and lift out the wood from the scored area. A helical slot extends through said sleeve from the raker tooth to receive the chip. A shank aligned with the guide shaft is used to connect the bit to a drill.
Abstract: A process for the preparation of expandable polymer particles containing a polymer of a vinylarene monomer and a foaming agent, which process comprises:1) polymerizing, by suspension polymerization, 100 parts by weight of a vinylarene monomer, in the presence of 1 to 20 parts by weight of a radical initiator having a half life of 1 hour in benzene at 70 to 110.degree. C., until at least 60% of the vinylarene monomer is polymerized;400 to 4,900 parts by weight additional vinylarene monomer as well as 0.05 to 1% wt, based on the amount of vinylarene monomer added in step 2, of a radical initiator having a half life of 1 hour in benzene at 70 to 110.degree. C. and polymerizing to completion, in which process the blowing agent can be added before, during or after the polymerization process.
Type:
Grant
Filed:
April 16, 1999
Date of Patent:
November 28, 2000
Assignee:
Nova Chemicals (International) S.A.
Inventors:
Rakesh Jaysinh Paleja, Dominique Paul Vliers, Maria Johanna Willems
Abstract: Organometallic complexes having a phosphinimine ligand, a (non-phosphinimine) heteroligand and at least one activatable ligand are catalyst components for olefin polymerization. Preferred polymerization systems are prepared by combining the organometallic complexes with an ionic activator and/or an alumoxane. Preferred catalyst components contain Ti, Zr or Hf and are activated with an ionic activator to provide ethylene polymerization catalysts.
Type:
Grant
Filed:
June 9, 1999
Date of Patent:
November 14, 2000
Assignee:
NOVA Chemicals (International) S.A.
Inventors:
Stephen John Brown, Xiaoliang Gao, Qinyan Wang, Peter Zoricak, Rupert Edward von Haken Spence, Wei Xu
Abstract: The present invention provides a novel process for preparing a catalyst, preferably free of electron donor, useful in gas phase polymerization of olefins having a broad polydispersity.
Type:
Grant
Filed:
May 12, 1998
Date of Patent:
October 31, 2000
Assignee:
Nova Chemicals Ltd.
Inventors:
Mark Kelly, Dusan Jeremic, Victoria Ker, Charles Russell
Abstract: Olefin co- or homopolymers having a good molecular weight and short chain branching may be prepared in the presence of a pyridyl bridged bisphosphinimine complex of a Group 8, 9 or 10 metal.