Dupont Canada Inc.

Nova Chemicals (international) S.a.

E.i. Dupont De Nemours and Company

Du Pont of Canada Limited

Vaclav G Zboril

David John Mitchell

Stephen John Brown

Darwin Edward Kiel

Edward Christopher Foy

John Iatrou

Umesh Karnik

Jesus Vela Estrada

Annette Lynn Burke

Sam Louis Samuels

John R Boocock

Ronald A Zelonka

Daniel J Gillis

Rolf Mulhaupt

Lynne M Manuel

Sylvie Cloutier

Reginald K Ungar

Millard C Hughson

By controlling the hold up times and temperatures for mixing the components of aluminum, titanium and magnesium based catalyst for solution polymerization it is possible to prepare a catalyst having a high activity, which prepares high molecular weight polyolefins. Generally, catalyst loses activity and produces lower molecular weight polymer at higher temperatures. The catalyst of the present invention permits comparable polymers to be produced at higher reaction temperatures.

High activity catalyst for high molecular weight polyolefins

By controlling the hold up times, concentrations and temperatures for mixing the components of aluminum, titanium and magnesium based catalyst for solution polymerization it is possible to prepare a catalyst having a high activity, which prepares high molecular weight polyolefins. Generally, a catalyst loses activity and produces lower molecular weight polymer at higher temperatures. The catalyst of the present invention permits comparable polymers to be produced with higher catalyst activity and at higher reaction temperatures by increasing the concentration of the components used during the preparation of the catalyst.

High activity ziegler-natta catalyst for high molecular weight polyolefins

A dual shear mixing element for use in a chemical reactor. The device may be used in processes where liquids of different temperatures need to be thoroughly mixed in a short period of time and solute must stay in solution. The present invention is particularly useful in the solution polymerization of polyolefins, especially in the medium pressure process for the preparation of linear low density polyethylene.

Polymerization process using a dual shear mixing element

A dual shear mixing element includes an auger and an impeller for use in a chemical reactor. The device may be used in processes where liquids of different temperatures need to be thoroughly mixed in a short period of time and solute must stay in solution. The present invention is particularly useful in the solution polymerization of polyolefins, especially in the medium pressure process for the preparation of linear low density polyethylene.

Mixing element for a chemical reactor

A solution process for the preparation of high molecular weight polymers of alpha-olefins selected from the group consisting of homopolymers of ethylene and copolymers of ethylene and C.sub.3 -C.sub.12 higher alpha-olefins is disclosed. Ethylene and/or mixtures of ethylene and C.sub.3 -C.sub.12 higher alpha-olefins are polymerized under non-isothermal conditions in a tubular reactor or in a system of reactors which operate under different conditions, in the presence of a catalytic amount of a titanium-containing coordination catalyst in an inert solvent at a temperature in excess of 105.degree. C. The improvement is characterized in that:

Control of a solution process for polymerization of ethylene

The present invention relates to a method for activating coordination catalysts suitable for the polymerization of alpha olefins using a alkoxy aluminum alkyl compound prepared by mixing an alcohol and an alkyl aluminum. The activator retains its activity and is easy to prepare simplifying the polymerization process.

Activation of catalyst in ethylene polymerization at high temperatures

A solution process, and a catalyst therefor, for the preparation of high molecular weight polymers of alpha-olefins viz. homopolymers of ethylene and copolymers of ethylene and C.sub.3 -C.sub.12 alpha-olefins, is disclosed. The process is operated under solution polymerization conditions at 105.degree.-320.degree. C. The catalyst is obtained from titanium tetrahalides, vanadium oxytrihalides and organoaluminum compounds, in which an admixture of catalyst components is heat-treated at 180.degree.-250.degree. C. and subsequently cooled to a temperature of less than 150.degree. C. Additional vanadium oxytrihalide is then added. The resultant catalyst solution is activated with an aluminum compound. The catalyst has good activity, showing superior activity to catalysts in which additional vanadium oxytrihalide is not added or added at temperatures above 150.degree. C.

Solution process for the preparation of polymers of .alpha.-olefins

The process of this invention for making strong, discontinuous fibers from a polyolefin includes feeding a solution of polyolefin dissolved in an organic solvent at a pressure that is at least autogenous pressure to a spinneret. Plexifilamentary film-fibril strands are formed by flash spinning, by passing said solution through the exit of the spinneret and into a tunnel at a lower pressure and temperature than the solution, the temperature being greater than the boiling point of the organic solvent. At or subsequent to the exit from the spinneret but inside the tunnel, the strands and solvent are contacted in the tunnel with an inert fluid that has a liquid and a vapor phase, the amount of inert fluid being such that the ratio of the total volumetric flow rate of solvent vapor plus inert fluid vapor to the mass flow rate of the polymer is greater than 4.5 m.sup.3 /kg in the tunnel. The temperature of the inert fluid in the tunnel is 2.degree.-40.degree. C. lower than the melting point of the polymer. Strong discontinuous fibers are recovered. The fibers, especially in the form of a pulp, may be used as part of thermally bonded blends with cellulose, as a filler and in the form of sheet.

Flash spinning process for forming strong discontinuous fibres

A method and apparatus for the monitoring and control of concentration of an ion in a solution at an elevated temperature of at least 100.degree. C. are disclosed. The method comprises the steps of contacting a first electrode with a flowing first solution containing said ion at the elevated temperature, and contacting a second electrode with a second flowing solution containing said ion at the elevated temperature. The rate of flow of the second solution is substantially lower than the rate of flow of the first solution. The first and second solutions are then contacted or admixed. The electrodes must be capable of detecting the ion at the elevated temperature and have the same response characteristics to changes in concentration of the ion at the elevated temperature. The concentration of the ion in the second solution is measured at a temperature lower than the elevated temperature under conditions permitting accurate measurement of the concentration of the ion, and the concentration of the ion in the first solution is monitored and controlled by adjusting the concentration of the ion in at least one of the first and second solutions. The method is particularly adapted for the monitoring and control of salt solutions used in the manufacture of polyamides, using palladium hydride electrodes.

Monitoring and control of process streams at elevated temperatures

A continuous process for the manufacture of a fibrous material from a polyolefin. The process comprises feeding a solution of polyolefin dissolved in an organic solvent at elevated temperature and pressure to a spinneret. The exit of the spinneret is the inlet to an elongated vertical tube and is located in an upper section of an elongated vertical vessel. The tube extends for a major portion of the length of the vessel. Solvent is removed from an upper section of the vessel and water is sprayed both down the tube and into the vessel. The strands thus formed are shredded in a self-cleaning self-feeding shredder located at the bottom of the vessel. The shredded fibres and water are conveyed to a second vessel having a baffle located between the inlet and outlet thereof such that the shredded fibrous material passes from the inlet, over the baffle and to the outlet of the second vessel, the upper lip of the baffle being so that the level of water in the second vessel is in substantially the same horizontal plane as the shredder. An inert gas e.g. steam, is fed to the second vessel to effect removal of volatile matter. The shredded fibres and liquid passing from the second vessel are fed to a dewatering device. The process may be used to manufacture fibrous polyolefin products e.g. the form of a pulp. The preferred polyolefin is a high molecular weight homopolymer of ethylene or copolymer of ethylene and at least one C.sub.4 -C.sub.10 hydrocarbon alpha-olefin.

Coupled spinning and dewatering process

A method is disclosed for the reduction of the extractability of trialkanolamines from polyolefins containing such compounds e.g. as a result of the use of trialkanolamines as catalyst deactivators in processes for the polymerization of olefins. Zinc oxide and/or zeolite molecular sieves are incorporated into the polyolefin, either during the process for the manufacture of the polyolefin or subsequent to such manufacture. Zinc oxide may be used in amount of 0.01-4 parts by weight and zeolite molecular sieves in amounts of 0.05-1 parts by weight, per 100 parts of polyolefin. The resultant compositions may be more acceptable for use in the fabrication of articles intended for the packaging of e.g. foodstuffs.

Polyolefin compositions containing trialkanolamines

A solution polymerization process for the preparation of high molecular weight polymers of alpha-olefins is disclosed. In the process, the coordination catalyst is deactivated using a solution of at least one trialkanolamine deactivating agent of the formula N(ROH)(R'OH).sub.2 where R is isopropyl and R' is alkyl of 2-4 carbon atoms, especially ethyl or isopropyl. The process is capable of producing polyers of improved color.

Isopropanolamines as catalyst deactivators in solution process for

A solution polymerization process for the preparation of high molecular weight polymers selected from the group consisting of homopolymers of ethylene and copolymers of ethylene and butene-1 is disclosed. The process comprises feeding monomer(s), coordination catalyst and inert hydrocarbon solvent to a reactor, polymerizing the monomers at a temperature of up to 320.degree. C. and a pressure of less than 25 MPa, and deactivating the catalyst in the solution so obtained. The catalyst is deactivated by sequentially admixing therewith a minor amount of dimethyl carbonate followed by a solution of a salt of an alkaline earth metal or zinc and an aliphatic monocarboxylic acid dissolved in hydrocarbon solvent. The hydrocarbon solvent and other volatile matter are then separated from the resultant solution and a composition comprising the high molecular weight polymer is recovered. The amount of dimethyl carbonate is not more than 2.5 moles, per mole of halogen plus alkyl radicals in the coordination catalyst.

Reduction of isomerization in solution process for polymerization of

A solution process, and a catalyst therefor, for the preparation of high molecular weight polymers of alph-olefins viz. homopolymers of ethylene and copolymers of ethylene and C.sub.3 -C.sub.12 alpha-olefins, is disclosed. The process is operated under solution polymerization conditions at 105.degree.-320.degree.. The catalyst is obtained from titanium tetrahalides, vanadium oxytrihalides and organoaluminum compounds, in which an admixture of catalyst components is heat-treated at 150.degree.-320.degree. C., and activated with an aluminoxane. The catalyst has good activity and the polymer obtained has improved color.

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Kingston, Canada

Vaclav G Zboril