Abstract: There is provided a process for the copolymerisation of propylene with at least one C4-20 &agr;-olefin or C4-20 diene in a reaction medium in the presence of a catalyst system at a temperature of greater that 80° C. or at a temperature and pressure above the critical temperature and pressure of the reaction medium. Under such conditions, comonomer incorporation is higher than under standard conditions.

Abstract: A process for the production of a propylene based polymer, the process comprising the following steps: (a) a first polymerization stage comprising homopolymerizing propylene or copolymerizing propylene and at least one alpha-olefin in the presence of an alpha-olefin polymerization catalyst whereby to produce a polypropylene component; (b) a second polymerization stage comprising copolymerizing ethylene and at least one alpha-olefin in the presence of an alpha-olefin polymerization catalyst whereby to produce an ethylene/alpha-olefin copolymer component; and (c) blending the polymer components produced in steps (a) and (b) whereby to produce a polymer blend, wherein the first and second polymerization stages are effected in separate polymerization reactors connected in parallel.

Abstract: Polypropylene heterophasic copolymers with good flow and impact properties are made by visbreaking a starting polypropylene heterophasic copolymer of which the amorphous rubber has an intrinsic viscosity of 2 dl/g or more and the ethylene content in the amorphous rubber, determined as C2 of AM, is from 20 wt-% to 45 wt-%.

Abstract: The invention provides a process for the production of a propylene based polymer, said process comprising the following steps: (a) a first polymerization stage comprising homopolymerizing propylene or copolymerizing propylene and at least one &agr;-olefin in the presence of an &agr;-olefin polymerization catalyst whereby to produce a polypropylene component; (b) a second polymerization stage comprising copolymerizing ethylene and at least one &agr;-olefin in the presence of an &agr;-olefin polymerization catalyst whereby to produce an ethylene/&agr;-olefin copolymer component; and (c) blending the polymer components produced in steps (a) and (b) whereby to produce a polymer blend, wherein said first and second polymerization stages are effected in separate polymerization reactors connected in parallel.

Abstract: Olefins or mixtures of olefins, particularly propene or mixtures of propene advantageously with ethene, can be polymerized using a Ziegler-Natta catalyst system containing, besides a transition-metal-based procatalyst and cocatalyst which is an organometallic compound, a compound particularly suited for controlling the stereospecificity of the produced polymer. Such a compound called an external donor may also have other effects. By using an acetal derivative of an aldehyde that has two ether groups for this purpose, advantageously selected from the group of dialkoxyphenylalkanes, e.g., dimethoxyphenylpropane, a good stereospecificity of the product is attained combined with the high hydrogen sensitivity of the catalyst system, whereby the use of hydrogen as the chain transfer agent offers an easy control method of the molecular weight of the product by means of adjusting the amount of hydrogen available in the polymerization reaction.