Polymer compositions
AssigneeBorealis Technology Oy
InventorsHanneli Seppänen, Hans Georg Daviknes
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Abstract
The present invention concerns a polymer composition and films manufactured from such compositions. The present polymer compositions comprise 80-99 wt-% on an essentially linear polyethylene with a component having a relatively low MW and a relatively high density, and another component having a relatively high MW and a relatively low density, said linear polyethylene having an MFR21 of at least 5 g/10 min, a maximum MFR2 of 6 g/10 min, a density of 915-945 kg/m3. Further the compositions contain 1-20 wt-% of a branched copolymer of ethylene and an acrylate monomer with 20-28 wt-% acrylate monomer units. The MFR2 of the copolymer is 0.4 to 2.0 g/10 min. Cross-laminated film materials having good mechanical properties can be manufactured from the present compositions.
Claims17
A cross-laminated film material comprising at least two oriented polymer film plies laminated together, each film being uniaxially oriented in a generally different direction with regard to each other, at least one of said polymer films comprising a polymer composition formed by
- (I) 80-99 wt-% of polyethylene, which comprises components (i) and (ii)
- wherein component (i) has a lower MW and a higher density than component (ii),
- said linear polyethylene having an MFR21 of at least 5 g/10 min, a maximum MFR2 of 6 g/10 min, a density of 915-945 kg/m3, and
- (II) 1-20 wt-% of a branched copolymer of ethylene and an acrylate monomer containing 20-28 wt-% acrylate monomer units, said copolymer having an MFR2 of 0.4 to 2.0 g/10 min.
A method of producing a cross-laminated film material comprising the steps of
- providing a polymer composition consisting essentially of
- (I) 80-99 wt-% of a polyethylene, which comprises components (i) and (ii), wherein
- component (i) has a lower MW and a higher density than component (ii), and
- said linear polyethylene having an MFR21 of at least 5 g/10 min, a maximum MFR2 of 6 g /10 min, a density of 915-945 kg/m3, and
- (II) 1-20 wt-% of a branched copolymer of ethylene and an acrylate monomer containing 20-28 wt-% acrylate monomer units, said copolymer having an MFR2 of 0.4 to 2.0 g/10 min,
- processing the polymer composition into a film,
- subjecting the film to helical cutting to provide film bands having oblique orientation,
- superimposing the film bands so that their directions of orientation are crossing;
- and
- laminating the bands together to form a cross-laminated film structure.
Dependencies are inferred from the claim text.