摘要:
A catalyst for the copolymerization of ethylene by the gas-phase fluidized-bed method is prepared by a process in which a titanium-containing and magnesium-containing active component, reacted with an alcohol as a complexing agent, is applied to a finely divided silica from homogeneous solution, in the presence of a polysiloxane, by evaporating the solvent, and the resulting homogeneous catalyst intermediate is then preactivated by treatment with the alkylaluminum compound and the Lewis base in an inert hydrocarbon solution, and the copolymers prepared using the above catalyst are employed for the production of films exhibiting little blocking.
摘要:
Ethene homopolymers and ethene copolymers with minor amounts of higher .alpha.-monoolefins are prepared by polymerization of the monomer or monomers using a chromium trioxide catalyst which is obtained by a method in which (1) a finely divided, porous, silicate carrier is laden with (2) chromium trioxide or a chromium compound which is converted to chromium trioxide under the conditions of stage (3), and then (3) the intermediate resulting from stage (2) is heated in an oxygen-containing gas stream. In this process, a cocatalyst which consists of a lithiumalkyl used in addition to the chromium trioxide catalyst.
摘要:
The present invention relates to a new solid catalytic component, which can be used in combination with an aluminum compound as co-catalyst and optionally an external electron donor as additional co-catalyst to form a catalytic system of the Ziegler-Natta-catalyst-type. The solid catalytic system comprises titanium or vanadium compound, a compound of magnesium containing at least one halogen, a particulate porous support, and optionally an internal electron donor.
摘要:
A process for the preparation of Ziegler-Natta type catalyst systems, containing, as active constituentsa) a titanium-containing solid component, which contains in addition to a compound of titanium at least one electron donor compound, and is present in an inert solvent in the form of a suspension, and, as co-catalyst,b) an aluminum compound andc) optionally further electron donor compoundsin which, following the preparation of the titanium-containing solid component a), the inert solvent present in the suspension is removed by first filtering the suspension in a first step, and then removing further solvent from the filtered material in a second step by applying a pressure difference at temperatures of not more than 100.degree. C.
摘要:
In a novel process for the preparation of a supported catalyst for the polymerization of .alpha.-olefins, a carrier gel (1) is first prepared by a method in which a sodium or potassium waterglass solution is introduced into a stream of an aqueous mineral acid which is subjected to angular momentum and may contain aluminum ions, longitudinally and tangentially to the stream, the resulting silica hydrosol sprayed in the form of drops into a gaseous medium and allowed to solidify into a hydrogel, and the resulting hydrogel is freed from salts by washing without prior aging and, if necessary, freed from some of the water by extraction with alcohols and/or ketones and is then dried. This gives the carrier gel (1), which is milled and is fractionated according to particle size. In a second process step, the carrier gel (1) is laden with chromium trioxide or with a chromium compound which can be converted into chromium trioxide, after which the resulting chromium-containing carrier gel (2) is heated at from 400.degree. to 1100.degree. C. for from 10 to 1,000 minutes in an anhydrous gas stream containing oxygen in a concentration of more than 10% by volume. In the novel process, it is essential that the drying of the hydrogel be carried out with formation of the carrier gel (1) in a fast dryer in the course of not more than 300 seconds at an inlet temperature of from 200.degree. to 600.degree. C. The supported catalyst prepared in this manner gives homo- and copolymers of ethylene having excellent low temperature impact strength.
摘要:
Catalyst systems of the Ziegler-Natta type comprise as active constituents a) a solid component comprising a compound of titanium or vanadium, a compound of magnesium, a particulate inorganic oxide as support and an internal electron donor compound, and as cocatalyst b) an aluminum compound and c) if desired, a further, external electron donor compound, wherein the particulate, inorganic oxide used has a specific surface area of from 350 to 1000 m2/g and a mean particle diameter {overscore (D)} in the range from 5 to 60 &mgr;m and comprises particles which are composed of primary particles having a mean particle diameter {overscore (d)} in the range from 1 to 10 &mgr;m and contain voids or channels between the primary particles, where the macroscopic proportion of voids or channels having a diameter of greater than 1 &mgr;m in the particles of the inorganic oxides is in the range from 5 to 30% by volume and the molar ratio of the compound of magnesium to the particulate, inorganic oxide is from 0.5:1 to 2.0:1.
摘要:
Homopolymerization and copolymerization of ethene is carried out using a Ziegler catalyst system consisting of (1) a transition metal catalyst component, (2) an organoaluminum catalyst component and (3) an organohalogen catalyst component. The component (1) used is the solid-phase product (VI) which has been obtained by a method in which (1.1) first (1.1.1) an inorganic oxidic substance (I) as a carrier and (1.1.2) a solution (II) of (IIa) a certain oxahydrocarbon and (IIb) a mixture of (IIb1) a vanadium trichloride/alcohol complex and (IIb2) a titanium trihalide or titanium trihalide/alcohol complex and (IIc) a silicon or boron compound are combined with formation of a suspension (III) and the latter is evaporated to form a solid-phase intermediate (IV) and (1.2) then (1.2.1) the intermediate (IV) obtained in (1.1) and (1.2.2) a dissolved organoaluminum compound (V) are combined with formation of a suspension, the solid-phase product (VI) formed as the suspended substance being the transition metal catalyst component (1).
摘要:
Ultrahigh molecular weight ethylene polymers are prepared in the gas phase in a thoroughly mixed bed of finely divided polymer by continuous introduction of the monomer into a polymerization system at 60.degree.-120.degree. C. and 5-60 bar in the presence of a reaction product of a titanium-containing catalyst and an antistat.
摘要:
The present invention relates to a new solid catalytic component, which can be used in combination with an aluminum compound as co-catalyst and optionally an external electron donor as additional co-catalyst to form a catalytic system of the Ziegler-Natta-catalyst-type. The solid catalytic system comprises titanium or vanadium compound, a compound of magnesium containing at least one halogen, a particulate porous support, and optionally an internal electron donor.
摘要:
In catalyst systems of the Ziegler-Natta type modified during their preparation and comprising as active constituentsa) a titanium-containing solid component which is obtained by reacting a compound of titanium with a compound of magnesium, a halogen, an inorganic oxide as support, a C.sub.1 -C.sub.8 -alkanol and a carboxylic ester as electron donor compound,and also as cocatalystb) an aluminum compound andc) if desired, a further electron donor compound,the titanium-containing solid component a) is prepared by first, in a first stage, admixing an inorganic oxide as support with a solution of a chlorine-free compound of magnesium in an inert solvent, stirring this mixture for from 0.5 to 5 hours at from 10 to 120.degree. C. and subsequently reacting it while stirring continually in an inert solvent with a C.sub.1 -C.sub.8 -alkanol in an at least 1.3-fold excess, based on the compound of magnesium, to give a chlorine-free intermediate, then, without purification or extraction of the intermediate, adding a compound of trivalent or tetravalent titanium and a carboxylic ester as electron donor compound to this intermediate, stirring the resulting mixture for at least 30 minutes at from 20 to 130.degree. C., subsequently filtering off and washing the solid thus obtained and subsequently, in a second stage, extracting the solid obtained from the first stage in an inert solvent comprising at least 5% by weight of titanium tetrachloride and washing it with a liquid alkane.