Melt fracture reduction
AssigneeNova Chemical Corporation
InventorsP. Scott Chisholm, Tony Tikuisis, Shivendra Kumar Goyal, Douglas Checknita, Nick Klaus Kurt Bohnet
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Abstract
The extrusion of thermoplastic polyolefin, especially linear low density polyethylene (LLDPE) is improved by the use of a processing additive comprising a blend of a thermoplastic acrylic polymer and a fluorocarbon polymer. In a preferred embodiment, the processing additive is a homogeneous blend of a thermoplastic styrene/methyl methacrylate polymer and a thermoplastic copolymer of vinylidene fluoride and hexafluoropropylene. The polyolefin extrudates produced according to this invention have reduced levels of melt fracture when extruded in conventional polymer extrusion equipment.
Claims5
An extrudable composition comprising:
- A) a major component of a thermoplastic polyolefin;
- and
- B) less than 1 weight percent, based on the weight of said thermoplastic polyolefin, of a premixed blend of a fluorocarbon polymer and an acrylic-containing thermoplastic polymer said acrylic-containing thermoplastic polymer comprising a copolymer of from about 45 to about 80 weight percent of bound styrene and from about 20 to about 55 weight percent of bound methyl methacrylate.
An extrudable composition comprising:
- A) a thermoplastic polyolefin;
- and
- B) from 0.01 to 0.2 weight per cent, based on the weight of said thermoplastic polyolefin, of a fluorocarbon polymer, with the provisos that:
- (a) said fluorocarbon polymer is provided as a component of a premixed blend with an acrylic-containing thermoplastic polymer;
- and
- (b) the weight ratio of said fluorocarbon polymer to said acrylic-containing thermoplastic polymer in said premixed blend is from about 95/5 to 5/95.
Dependencies are inferred from the claim text.