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 and in the presence of a monohydric or polyhydric alcohol.
摘要:
A supported catalyst for ethene polymerization by Phillips catalysis is disclosed. The supported catalyst is prepared by (1) mixing a porous silicate in an inert, organic liquid to produce a silicate suspension, (2) providing an ester of phosphoric acid or phosphorous acid, (3) mixing an organic liquid, a chromium compound, and a trialkylaluminum compound to produce a chromium compound/aluminum compound and combining the silicate suspension, the phosphorus compound and the chromium compound/aluminum compound suspension. This resulting suspension is evaporated to dryness to form a catalyst intermediate. The catalyst intermediate is heated in nitrogen, then heated in an oxygen-containing atmosphere, and then heated again in nitrogen to produce an activated catalyst. The activated catalyst is suspended in an organic liquid and treated with an alkyl boron compound to produce the desired supported catalyst.
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:
A novel Phillips catalyst for the copolymerization of ethylene with .alpha.-olefins, contains, as a catalytically active component, a finely divided, aluminum silicate-supported, phosphorus-containing chromium catalyst. This can be prepared by applying at least one organic phosphorus(III), (IV) and/or (V) compound and at least one chromium(III) compound which does not react with said phosphorus compounds under the reaction conditions used, in succcession in any order or simultaneously, to a finely divided aluminum silicate hydrogel or xerogel with formation of a catalyst intermediate and activating the catalyst intermediate at elevated temperatures in an oxidizing atmosphere, with the result that the chromium catalyst is formed. The novel Phillips catalyst gives ethylene/.alpha.-olefin copolymers in which the comonomers are more uniformly distributed over the copolymer chains than is the case with ethylene/.alpha.-olefin copolymers which have been prepared with the aid of conventional Phillips catalysts. Moldings which have been produced from the ethylene/.alpha.-olefin copolymers obtained in the novel procedure have a particularly high environmental stress cracking resistance and an excellent creep rupture strength.
摘要:
A novel Phillips catalyst for the copolymerization of ethylene with .alpha.-olefins, contains, as a catalytically active component, a finely divided, aluminum silicate-supported, phosphorus-containing chromium catalyst. This can be prepared by applying at least one organic phosphorus(III), (IV) and/or (V) compound and at least one chromium(III) compound which does not react with said phosphorus compounds under the reaction conditions used, in succcession in any order or simultaneously, to a finely divided aluminum silicate hydrogel or xerogel with formation of a catalyst intermediate and activating the catalyst intermediate at elevated temperatures in an oxidizing atmosphere, with the result that the chromium catalyst is formed. The novel Phillips catalyst gives ethylene/.alpha.-olefin copolymers in which the comonomers are more uniformly distributed over the copolymer chains than is the case with ethylene/.alpha.-olefin copolymers which have been prepared with the aid of conventional Phillips catalysts. Moldings which have been produced from the ethylene/.alpha.-olefin copolymers obtained in the novel procedure have a particularly high environmental stress cracking resistance and an excellent creep rupture strength.
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:
A process for the continuous preparation of finely divided homopolymers and copolymers of ethene by catalytic polymerization in a circular tube reactor using a liquid alkane as reaction medium in which the ethene or ethene/comonomer mixture to be polymerized is present in dissolved form and the polymer formed is present in suspended form and running the reaction mixture as a cycle stream to which the feed materials are added by bleeding in and from which the polymer formed is withdrawn by bleeding out reaction mixture, comprising (a) maintaining the mean concentration C.sub.m of polymer in the cycle stream at a value within a certain range and (b) effecting the bleeding out of reaction mixture at a point of the cycle stream at which the concentration of polymer has a value which is lower than the mean concentration C.sub.m by a distinct and definite amount.
摘要:
A process for introducing a catalyst powder based on a titanium compound supported on magnesium halide into a gas-phase olefin polymerization reactor, characterized in that it comprises: (a) storing the catalyst powder under an atmosphere of a liquid C3-C12 alkane; (b) withdrawing from step (a) a measured amount of said catalyst powder by means of a rotary valve; (c) transferring said metered amount of catalyst powder to a catalyst activation section by a continuous pick-up flow of a liquid C3-C12 alkane; (d) contacting the catalyst powder with a liquid phase comprising an organo-aluminum compound and optionally an external donor compound, at a temperature ranging from −20° C. to 60° C.; (e) introducing the activated catalyst powder in one or more gas-phase olefin polymerization reactors, where a gaseous mixture comprising at least one alpha-olefin is subjected to polymerization.
摘要:
A process for introducing a catalyst powder based on a titanium compound supported on magnesium halide into a gas-phase olefin polymerization reactor, characterized in that it comprises: (a) storing the catalyst powder under an atmosphere of a liquid C3-C12 alkane; (b) withdrawing from step (a) a measured amount of said catalyst powder by means of a rotary valve; (c) transferring said metered amount of catalyst powder to a catalyst activation section by a continuous pick-up flow of a liquid C3-C12 alkane; (d) contacting the catalyst powder with a liquid phase comprising an organo-aluminum compound and optionally an external donor compound, at a temperature ranging from −20° C. to 60° C.; (e) introducing the activated catalyst powder in one or more gas-phase olefin polymerization reactors, where a gaseous mixture comprising at least one alpha-olefin is subjected to polymerization.