Nova Chemicals (international) S.a.

Nova Chemicals Inc.

Norman Aubee

XiaoChuan Wang

Peter Zoricak

Brian Molloy

Qinyan Wang

Lawrence VanAsseldonk

P Scott Chisholm

Shivendra K Goyal

Tony Tikuisis

Bronwyn Gillon

Douglas Checknita

Owen Lightbody

Nitin Borse

Stephen John Brown

Patrick Lam

Derek Wasylenko

Maryam Fereydoon

Fraser Waldie

Lison Mark

Thomas Green

Christian Carello

Jared Taylor

Lawrence Vanasseldonk

A polymer processing aid (PPA) reduces melt defects in extruded polyolefins in the absence of fluoropolymers. The polymer processing aid comprises a polyalkylene glycol such as a polyethylene glycol together with a high pressure low density polyethylene (LDPE) and reduces melt defects well in a thermoplastic polyolefin such as a linear low density polyethylene (LLDPE).

Fluoropolymer free polymer processing aids

A Biaxially Oriented Polyethylene (BOPE) process uses a selected polyethylene having a medium density and a very broad molecular weight distribution. The use of this selected polyethylene facilitates stretching in the BOPE process in comparison to previously used polyethylene resins having a higher density and/or a narrower molecular weight distribution.

Biaxially oriented MDPE film

An ethylene copolymer comprising ethylene and at least one alpha olefin having from 4 to 8 carbon atoms has a density f from 0.940 to 0.960 g/cm, a molecular weight distribution, Mw/Mn of from 9 to 12, and a Z-average molecular weight, Mz of greater than 500,000. The ethylene copolymer is made in a multi-zone reactor system under solution phase polymerization conditions and is useful in the preparation of biaxially oriented polyethylene (BOPE) films.

Ethylene copolymer for biaxial orientation

A polyethylene composition which when made into a film layer having a thickness of about 1 mil has a machine direction (MD) 1% secant modulus of ≥200 MPa and an oxygen transmission rate (OTR) of ≥600 cmper 100 inchper day and when made into a film layer having a thickness of about 2 mil has a seal initiation temperature (SIT) of ≤90° C. and an area of hot tack window (AHTW) of ≥160 Newtons·° C.

Polyethylene composition and film having high stiffness, outstanding sealability and high permeability

In the manufacture of extruded polymers there are a number of surface defects referred to as sharkskin, snakeskin and orange peel which all generally relate to the rheology of the polymer melt. A severe form of surface defect is 'melt fracture' which is believed to result when the shear rate at the surface of the polymer is sufficiently high that the surface of the polymer begins to fracture. That is, there is a slippage of the surface of the extruded polymer relative to the body of the polymer melt. The surface generally can't flow fast enough to keep up with the body of the extrudate and a fracture in the melt occurs generally resulting in a severe loss of surface properties for the extrudate. A polymer extension process is disclosed wherein these undesirable surface defects are eliminated.

Polymer extrusion process

A polyethylene composition including a first polyethylene which is an ethylene copolymer having a weight average molecular weight of from 70,000 to 250,000 and a molecular weight distribution M/Mof &#x3c;2.3, a second polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of from 50,000 to 200,000 and a molecular weight distribution M/Mof &#x3c;2.3, and a third polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of from 70,000 to 200,000 and a molecular weight distribution M/Mof &#x3c;2.3, where the first polyethylene has more short chain branching than the second polyethylene or the third polyethylene.

Polyethylene composition and film having outstanding properties

A thermoformable film comprises a polyethylene composition. The polyethylene composition comprises a first polyethylene which is an ethylene copolymer having a weight average molecular weight of from 70,000 to 250,000 and a molecular weight distribution M/Mof &#x3c;2.3, a second polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of from 15,000 to 100,000 and a molecular weight distribution M/Mof &#x3c;2.3, and a third polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of from 70,000 to 250,000 and a molecular weight distribution M/Mof &#x3e;2.3, where the first polyethylene has more short chain branching than the second polyethylene or the third polyethylene. The polyethylene composition has a melt flow ratio (I/I) of &#x2264;50 and an area Dimensional Thermoformability Index (aDTI) at 105&#xb0; C. of less than 15.

Thermoformable film

A thermoformable film including a polyethylene composition. The polyethylene composition includes a first polyethylene which is an ethylene copolymer having a weight average molecular weight of from 70,000 to 250,000 and a molecular weight distribution M/Mof &#x3c;2.3, a second polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of less than 75,000 and a molecular weight distribution M/Mof &#x3c;2.3, a third polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of less than 75,000 and a molecular weight distribution M/Mof &#x3c;2.3, and a fourth polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of from 100,000 to 250,000 and a molecular weight distribution M/Mof &#x3e;2.3, where the first polyethylene has more short chain branching than the second polyethylene or the third polyethylene. The polyethylene composition has a melt flow ratio (I/I) of &#x2264;55 and an area Dimensional Thermoformability Index (aDTI) at 105&#xb0; C. of less than 15.

A multilayer film having Machine Direction Orientation (MDO) is prepared by first co-extruding a multilayer film, then stretching the multilayer film in the machine direction at a temperature lower than the melting point of the polyethylene resin that is used to prepare the film. At least one layer of the film is a first polyethylene composition having a density of from about 0.94 to about 0.97 g/cc and at least one second layer is prepared from a polyethylene composition having a lower density than the first polyethylene composition. This disclosure enables the manufacture of films having outstanding barrier properties (low Water Vapor Transmission Rate, WVTR, and low Oxygen Transmission Rate, OTR) and good physical properties.

MDO multilayer film

A polyethylene composition includes a first polyethylene which is an ethylene copolymer having a weight average molecular weight of from 70,000 to 250,000 and a molecular weight distribution Mw/Mn of &#x3c;2.3, a second polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of from 15,000 to 100,000 and a molecular weight distribution Mw/Mn of &#x3c;2.3, and a third polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of from 70,000 to 250,000 and a molecular weight distribution Mw/Mn of &#x3e;2.3, where the first polyethylene has more short chain branching than the second polyethylene or the third polyethylene. The polyethylene composition has a soluble fraction in a CEF analysis of at least 10 weight percent. Film made from the polyethylene composition may have a machine direction 1% secant modulus of &#x25a1;190 MPa (at a film thickness of about 1 mil), a seal initiation temperature (SIT) of &#x2264;100&#xb0; C. (at a film thickness of about 2 mil), an area of hot tack window (AHTW) of &#x2265;160 Newtons&#xb7;C&#xb0; (at a film thickness of about 2 mil) and an oxygen transmission rate (OTR) of &#x2265;650 cm3 per 100 inch2 per day (at a film thickness of about 1 mil).

Polyethylene composition and film having a good permeability, stiffness and sealability

A polyethylene composition comprises a first polyethylene which is an ethylene copolymer having a weight average molecular weight of from 70,000 to 250,000 and a molecular weight distribution M/Mof &#x3c;2.3, a second polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of from 50,000 to 200,000 and a molecular weight distribution M/Mof &#x3c;2.3, and a third polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of from 70,000 to 200,000 and a molecular weight distribution M/Mof &#x3c;2.3, where the first polyethylene has more short chain branching than the second polyethylene or the third polyethylene. The polyethylene composition has a composition distribution breadth index, CDBIobtained from a crystallization elution fractionation (CEF) analysis of &#x3c;45 weight %. A film made from the polyethylene composition may have a machine direction 1% secant modulus of &#x2265;200 MPa (at a film thickness of about 1 mil), a seal initiation temperature (SIT) of &#x2264;85&#xb0; C. (at a film thickness of about 2 mil), an area of hot tack window (AHTW) of &#x2265;220 Newtons&#xb7;C&#xb0; (at a film thickness of about 2 mil), an oxygen transmission rate (OTR) of &#x2265;600 cmper 100 inchper day (at a film thickness of about 1 mil), a dart impact strength of &#x2265;400 g/mil, and a machine direction (MD) tear strength of &#x2265;400 g/mil.

A polyethylene composition includes a first polyethylene which is an ethylene copolymer having a weight average molecular weight of from 70,000 to 250,000 and a molecular weight distribution M/Mof &#x3c;2.3, a second polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of from 15,000 to 100,000, a molecular weight distribution M/Mof &#x3e;2.3, and a third polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of from 70,000 to 250,000 and a molecular weight distribution M/Mof &#x3e;2.3, where the first polyethylene has more short chain branching than the second polyethylene or the third polyethylene. The polyethylene composition has a soluble fraction in a CEF analysis of at least 10 weight percent. Film made from the polyethylene composition may have a machine direction 1% secant modulus of 200 &#x2265;MPa (at a film thickness of about 1 mil), a seal initiation temperature (SIT) of &#x2264;90&#xb0; C. (at a film thickness of about 2 mil), an area of hot tack window (AHTW) of &#x2265;160 Newtons&#xb7;C&#xb0; (at a film thickness of about 2 mil) and an oxygen transmission rate (OTR) of &#x2265;600 cmper 100 inch per day (at a film thickness of about 1 mil).

A polyethylene composition including a first polyethylene which is an ethylene copolymer having a weight average molecular weight of from 70,000 to 250,000 and a molecular weight distribution M/Mof &#x3c;2.3, a second polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of less than 75,000 and a molecular weight distribution M/Mof &#x3c;2.3, and a third polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of from 100,000 to 300,000 and a molecular weight distribution M/Mof &#x3e;2.3, where the first polyethylene has more short chain branching than the second polyethylene or the third polyethylene. The polyethylene composition has a soluble fraction in a CEF analysis of at least 15 weight percent. A film made from the polyethylene composition may have a machine direction 1% secant modulus of &#x2265;200 MPa (at a film thickness of about 1 mil) and an oxygen transmission rate (OTR) of &#x2265;700 cmper 100 inchper day (at a film thickness of about 1 mil). A film made from the polyethylene composition retains much of its dart impact performance on downgauging from a thickness of 1 mil to a thickness of 0.75 mil.

Polyethylene composition and film having retained dart impact

In some embodiments disclosed herein are polyethylene composition including a first polyethylene which is an ethylene copolymer having a weight average molecular weight of from 70,000 to 250,000 and a molecular weight distribution M/Mof &#x3c;2.3, a second polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of less than 75,000 and a molecular weight distribution M/Mof &#x3c;2.3, a third polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of less than 75,000 and a molecular weight distribution M/Mof &#x3c;2.3, and a fourth polyethylene which is an ethylene copolymer or homopolymer having a weight average molecular weight of from 100,000 to 250,000 and a molecular weight distribution M/Mof &#x3e;2.3, where the first polyethylene has more short chain branching than the second polyethylene or the third polyethylene. The polyethylene composition may have a soluble fraction in a CEF analysis of at least 7.5 weight percent. Film made from the polyethylene composition may have a machine direction 1% secant modulus of 200 MPa (at a film thickness of about 1 mil) and an oxygen transmission rate (OTR) of &#x2265;550 cmper 100 inch per day (at a film thickness of about 1 mil). Film made from the polyethylene composition retains much of its dart impact performance on downgauging from a thickness of 1 mil to a thickness of 0.75 mil.

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Okotoks, Canada

Norman Aubee