Bp Chemicals Limited

John Gabriel Speakman

Alain Berardi

Laszlo Havas

Claudine Viviane Lalanne-Magne

Erick Dominique Daire

Claude Chamla

The present invention relates to a process for the polymerization and copolymerization of 1-olefins and to a catalyst to be used in said process wherein the catalyst comprises (1) a complex having formula (I) wherein M is Fe&lsqb;II&rsqb;, Fe&lsqb;III&rsqb;, Co&lsqb;I&rsqb;, Co&lsqb;II&rsqb;, Co&lsqb;III&rsqb;, Mn&lsqb;I&rsqb;, Mn&lsqb;II&rsqb;, Mn&lsqb;III&rsqb;, Mn&lsqb;IV&rsqb;, Ru&lsqb;II&rsqb;, Ru&lsqb;III&rsqb; or Ru&lsqb;IV&rsqb;; X represents an atom or group covalently or ionically bonded to the metal M; T is the oxidation state of the metal; b is the valency of the atom or group X; and R 1 to R 7 are each independently selected from hydrogen, halogen, hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl, substituted heterohydrocarbyl or SiR&prime; 3 where each R&prime; is independently selected from hydrogen, halogen, hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl, substituted heterohydrocarbyl; and when any two or more of R 1 to R 7 are hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl or substituted heterohydrocarbyl, said two or more can be linked to form one or more cyclic substituents; (2) an activator which is an alkylalumoxane; and (3) a support material, wherein the atomic ratio of aluminium in the alkylalumoxane (2) to transition metal M in (1) is from 6:1 to 25:1.

Polymerization catalysts

Polymerisation catalyst

A process for the polymerization of 1-olefins which comprises the steps of a) preparing a prepolymer-based catalyst by contacting one or more 1-olefins with a catalyst system, and b) contacting the prepolymer-based catalyst with one or more 1-olefins, wherein the catalyst system comprises (1) a compound of formula (I) wherein M is Fe&lsqb;II&rsqb;, Fe&lsqb;III&rsqb;, Co&lsqb;I&rsqb;, Co&lsqb;II&rsqb;, Co&lsqb;III&rsqb;, Mn&lsqb;I&rsqb;, Mn&lsqb;II&rsqb;, Mn&lsqb;III&rsqb;, Mn&lsqb;IV&rsqb;, Ru&lsqb;II&rsqb;, RU&lsqb;III&rsqb; or Ru&lsqb;IV&rsqb;; X represents an atom or group covalently or ionically bonded to the transition metal M; T is the oxidation state of the transition metal M and b is the valency of the atom or group X; R , R , R , R , R , R and R are independently selected from hydrogen, halogen, hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl or substituted heterohydrocarbyl; and when any two or more of R -R are hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl or substituted heterohydrocarbyl, said two or more can be linked to form one or more cyclic substituents; optionally (2) an activator, and also optionally (3) a compound of the formula AlR , wherein each R is independently C -C alkyl or halo.

Polymerization process

An improved chromium oxide-based catalyst supported on a granular or microspherical refractory oxide for the gas phase polymerization of at least one alpha olefin containing from 2 to 12 carbon atoms, wherein the supported chromium oxide-based catalyst has been subjected to a sole calcination/activation step consisting of a single thermal treatment performed at a temperature ranging from 200&deg; to 450&deg; C. under an oxygen containing atmosphere, and an olefin polymerization process employing such catalyst.

Process for the gas phase polymerization of olefins

The present invention relates to a process for stopping an olefin polymerization which is carried out in a low pressure gas phase reactor, which process comprises introducing an effective quantity of deactivating agent into the reactor, characterized in that the olefin polymerisation is carried out using a chromium oxide catalyst and in that the deactivating agent is selected from oxygen, ammonia, water and carbon monoxide and is introduced over a relatively short period of time. The deactivating agent is preferably introduced into the polymerization reactor in a quantity such that in the reactor the weight ratio of the deactivating agent to the catalyst is at least 0.001.

Kill-gas introduction to a fluidized bed reactor containing chromium

The present invention relates to an alpha-olefin prepolymer catalytically active in an alpha-olefin (co-)polymerization comprising a transition metal, an organometallic compound and an antistatic agent. The prepolymer can be prepared by contacting the antistatic agent with a catalyst comprising the transition metal and the organometallic compound before or during an alpha-olefin prepolymerization. It can also be prepared by contacting the antistatic agent with an alpha-olefin prepolymer after a prepolymerization. It can also be prepared by a combination of the two methods. The prepolymer can be introduced into a gas phase (co-)polymerization medium for preparing polyolefin directly in a dry powder form, with a reduced amount of sheeting and agglomerates.

Gas phase olefin polymerization process

The present invention relates to a process for (co-)polymerizing ethylene in a gaseous phase, by means of a fluidized and/or mechanically stirred bed reactor, with the help of a catalyst comprising a chromium oxide and a titanium compound, supported on a refractory oxide and activated by a heat treatment. The process is characterized in that the catalyst is introduced into the reactor in the form of a dry powder consisting of particles free from prepolymer and the (co-)polymerization is carried out in the presence of an organoaluminium compound. The (co-)polymer thus obtained has substantially low catalyst residues, and an improved stress cracking resistance.

Process for the gas phase (co-)polymerization of ethylene

Process for polymerising ethylene, or copolymerising ethylene with an alpha-olefin, in the gas phase in the presence of a prepolymer/catalyst composition, the catalyst being an activated chromium oxide supported on a refractory oxide. The prepolymer is treated to an extraction with a solution comprising inert hydrocarbon and an organometallic compound, for example an alkylaluminum, prior to being dried and introduced into the gas phase (co) polymerisation. Prepolymer thus treated has improved properties in the dry state, for example improved flow.

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Martigues, France

John Gabriel Speakman