Neste Oy

Borealis Technology Oy

Valtion Teknillinen Tutkimuskeskus

Borealis Holding A/s

Mika Harkonen

Jukka Seppala

Kari Hiltunen

Timo Leinonen

Kauno Alastalo

Johan-Fredrik Selin

Eero I Iiskola

Arild Follestad

Christer Hans Bergstrom

Espen Ommundsen

Esa Suokas

Doris Pospiech

Pentti Passiniemi

Frank Bohme

Merja Poikela

Tarja Soderberg

Manfred Ratzsch

Minna Malin

Janne Kylma

Heli Alanko

Jyrki Hakola

Jukka Tulisalo

Paivi L Pitkanen

Ann Britt Bjaland

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. Also provided are polymer compositions comprising: (i) 30 to 97% by weight, based on the total weight of the polymer composition, of a propylene based polymer; and (ii) 3 to 70% by weight, preferably 5 to 20% by weight, based on the total weight of the polymer composition, of an ethylene copolymer plastomer (e.g., an ethylene-propylene plastomer) containing at least 60% by weight ethylene.

Process for producing propylene based polymer compositions

Polymer films and process for the preparation thereof

Melt-processible poly (ester urethane) and a process for the preparation

Thermoplastic biodegradable polyester a process for the preparation

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. The acetal derivative is a compound according to formula (III): ##STR1## wherein R is C.sub.1-4 alkyl group, R.sup.1 and R.sup.2 are the same or different and each is a hydrocarbon group or a group which can together form a ring, R.sup.3 is hydrogen or a hydrocarbon group. If with the acetal derivative donor is used a clearly less hydrogen sensitive donor, e.g., alkoxysilanes, much broader MWD's of the product are achieved.

Stereospecific catalyst system for polymerization of olefins

Melt-processable block copolyesterimide and method for manufacturing it

Growing community of inventors

Vantaa, Finland

Mika Harkonen