Borealis Technology Oy

Optatech Corporation

Mika H&auml;rk&ouml;nen

Bo Malm

Pauli Leskinen

Erkki Laiho

Amir K Karbasi

Esa Suokas

Anders E Nymark

Marja Ora

P&auml;ivi Pitk&auml;nen

Pirjo Jaaskel&auml;inen

John Haugen

Seppo Kuusela

The present invention concerns a process for producing a propylene polymer nucleated with a polymeric nucleating agent containing vinyl compound units. The method comprises modifying a catalyst by polymerizing a vinyl compound in the presence of said catalyst in a medium, which does not essentially dissolve the polymerized vinyl compound, and by continuing the polymerization of the vinyl compound until the concentration of unreacted vinyl compounds is less than about 0.5 wt-%. The thus obtained modified catalyst composition is used for polymerizing propylene optionally together with comonomers to produce in the presence of said modified catalyst composition. Modification of the catalyst according to the present invention will reduce production costs and provide highly reliable catalyst activity.

Process for preparing polypropylene

The present invention concerns a multilayered polymer film structure, which comprises at least one first layer (,) containing a thermoplastic polymer and at least one second layer (,), arranged adjacent to said first layer, containing a liquid crystalline polymer. According to the invention, the second layer (,) consists essentially of a compounded polymer blend formed by the liquid crystalline polymer and a thermoplastic polymer, the liquid crystalline polymer of the second layer forms a continuous phase, and the first and the second layers (,) contain the same thermoplastic polymer. The oxygen transmission rate of the second layer is less than about 150 cm,/(m,&middot;d&middot;bar), determined according to the standard ASTM D 3985-81, and the water vapour transmission rate of the integral film structure is less than 10 g/(m,&middot;24&middot;h) at RH 80% 23&deg; C., determined according to ASTM F 1249-90. The present structure can be used as a barrier layer in packages.

Multilayered polymer films and process for the preparation thereof

The invention relates to a process for the preparation of a creep-resistant polypropylene by means of the following steps: (a) copolymerizing propylene and ethylene into a random copolymer at 40 to 110&deg; C. using: a catalyst system of the above-mentioned type; a portion of ethylene or C,-C,-&agr;-olefin leading to 1.0 to 10.0% by weight of ethylene repeating units in said random copolymer; and no or a minimal amount of hydrogen leading to a MFR,value of between 0.01 and 5.0 g/10 min for said random copolymer, if this step is performed first, or to a MFR,value for said polypropylene of between 0.05 and 0.40 g/10 min, if this step is performed after step (b); the proportion of random copolymer of this step being from 20 to 80% by weight of said polypropylene, (b) polymerizing propylene at 40 to 110&deg; C. using: a catalyst system of the above-mentioned type; no or a minimal portion of ethylene leading to 0.0 to 1.0% by weight of ethylene repeating units in the polymer resulting from this step; and an amount of hydrogen leading to a MFR,value of between 30 and 300 g/10 min for said polymer, if this step is performed first, or to a MFR,value for said polypropylene of between 0.05 and 0.40 g/10 min, if this step is performed after step (a); the proportion of polymer of this step being from 80 to 20% by weight of said polypropylene.

Process for the preparation of creep-resistant polypropylene block copolymers

Growing community of inventors

Vantaa, Finland

Mika Härkönen

Growing community of inventors

Vantaa, Finland

Mika H&auml;rk&ouml;nen

Mika Härkönen