Extrusion coating polyethylene with improved drawdown
AssigneeBorealis AG
InventorsMarkku Sainio, Auli Nummila-Pakarinen
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Abstract
Use of an antioxidant being a sterically hindered phenol for increasing the drawdown speed of a low density polyethylene in an extrusion coating process.
Claims14
Article comprising a substrate and at least one polymer layer, said polymer layer is extrusion coated on the substrate, wherein the polymer layer comprises a composition (Co) comprising a low density polyethylene (LDPE) and a primary antioxidant (PAO), wherein:
- the polymer layer and/or the composition (Co) has/have a melt flow rate MFR2 (190° C.) of at least 2.0 g/10 min,
- and wherein further the melt flow rate MFR2 (190° C.) of the composition (Co) before and after extrusion are
- 1.5
- ≥
- MFR
-
- (
- after
- )
- MFR
-
- (
- before
- )
- ≥
- 0.5
- wherein
- MFR (after) is the melt flow rate MFR2 (190° C.) of the composition (Co) after extrusion coating;
- MFR (before) is the melt flow rate MFR2 (190° C.) of the composition (Co) before extrusion coating.
Article comprising a substrate and at least one polymer layer, said polymer layer is extrusion coated on the substrate, wherein the polymer layer comprises a composition (Co) comprising a low density polyethylene (LDPE) and a primary antioxidant (PAO), wherein:
- the polymer layer and/or the composition (Co) has/have a melt flow rate MFR2 (190° C.) of at least 2.0 g/10 min,
- wherein further the amount of primary antioxidant (PAO) is in the range of 15 to 2,500 ppm and at least in an amount preventing a change of the melt flow rate MFR2 (190° C.) of the composition (Co) during extrusion coating of more than 40%.
A process of extrusion coating a substrate with a draw-down speed of at least 300 m/min by extruding a composition (Co) in a molten state through a flat die onto said substrate at a temperature of from 275 to 330° C., wherein said composition (Co) comprises low density polyethylene (LDPE) and from 15 to 2,500 ppm of a primary antioxidant (PAO).
(canceled)
14-16. (canceled)
Dependencies are inferred from the claim text.