Process for making multiphase polymeric film having a lamellar structure with controlled permeability and/or controlled mechanical properties

A process for making a multiphase polymeric film having a lamellar structure with controlled permeability, comprising the steps of:

• preparing a molten blend comprising:
• a first polymer phase dispersed in a second polymer phase which is a matrix polymer phase incompatible with the said first phase, and
• a compatibilizer selected from the group consisting of DEM, DEM-g-SEBS and DEM-g-PP;
• extruding the molten blend through a flat die provided with an exit;
• stretching the so-extruded blend downstream of said exit at a preselected stretching ratio to produce the said multiphase polymeric film;
• and
• solidifying the extruded film sufficiently rapidly to preserve the lamellar structure;
• wherein a permeability of the polymeric film to oxygen gas under an O2/N2 relative humidity of 90%/90% is 5.4 mm*cm3/(m2*day*atm) or less.

A process for making a multiphase polymeric film having a lamellar structure with controlled permeability, comprising the steps of:

• preparing a molten blend comprising:
• a first polymer phase dispersed in a second polymer phase which is a matrix polymer phase incompatible with the said first phase, and
• a compatibilizer selected from the group consisting of DEM, DEM-g-SEBS and DEM-g-PP;
• extruding the molten blend through a flat die provided with an exit;
• stretching the so-extruded blend downstream of said exit at a preselected stretching ratio to produce the said multiphase polymeric film;
• and
• solidifying the extruded film sufficiently rapidly to preserve the lamellar structure;
• wherein a barrier property of the polymeric film to oxygen gas under an O2/N2 relative humidity of 31%/dry is least 87% better than a barrier property to oxygen gas of a polymeric film comprising the blend of the first polymer phase and the second polymer phase without the compatibilizer under the same conditions.

A process for making a multiphase polymeric film having a lamellar structure with controlled permeability, comprising the steps of:

• preparing a molten blend comprising:
• a first polymer phase dispersed in a second polymer phase which is a matrix polymer phase incompatible with the said first phase, and
• a compatibilizer selected from the group consisting of DEM, DEM-g-SEBS and DEM-g-PP;
• extruding the molten blend through a flat die provided with an exit;
• stretching the so-extruded blend downstream of said exit at a preselected stretching ratio to produce the said multiphase polymeric film;
• and
• solidifying the extruded film sufficiently rapidly to preserve the lamellar structure;
• wherein a barrier property of the polymeric film to oxygen gas under an O2/N2 relative humidity of 31%/dry is least 97% better than a barrier property to oxygen gas of a polymeric film consisting of the first polymer phase under the same conditions.

A process for making a multiphase polymeric film having a lamellar structure with controlled permeability, comprising the steps of:

• preparing a molten blend comprising:
• a first polymer phase dispersed in a second polymer phase which is a matrix polymer phase incompatible with the said first phase, and
• a compatibilizer selected from the group consisting of DEM, DEM-g-SEBS and DEM-g-PP;
• extruding the molten blend through a flat die provided with an exit;
• stretching the so-extruded blend downstream of said exit at a preselected stretching ratio to produce the said multiphase polymeric film;
• and
• solidifying the extruded film sufficiently rapidly to preserve the lamellar structure;
• wherein a barrier property of the polymeric film to oxygen gas under an O2/N2 relative humidity of 90%/90% is least 93% better than a barrier property to oxygen gas of a polymeric film consisting of the first polymer phase under the same conditions.

A process for making a multiphase PP/EVOH/compatibilizer polymeric film having a lamellar structure with controlled permeability, comprising the steps of:

• preparing a molten blend comprising:
• EVOH dispersed in PP;
• and
• a compatibilizer selected from the group consisting of DEM-g-SEBS and DEM-g-PP;
• extruding the molten blend through a flat die provided with an exit;
• stretching the so-extruded blend downstream of said exit at a preselected stretching ratio to produce the said multiphase polymeric film;
• and
• solidifying the extruded film sufficiently rapidly to preserve the lamellar structure;
• wherein a barrier property of the PP/EVOH/compatibilizer polymeric film to oxygen gas under an O2/N2 relative humidity of 31%/dry is least 88% better than a barrier property to oxygen gas of a PP/EVOH/PP-g-MAH polymeric film under the same conditions.