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US 6,642,310 B2Granted
Process aid for melt processable polymers
AssigneeDuPont Dow Elastomers L.L.C.
InventorsGeorge Richard Chapman, Jr., Steven Richard Oriani
Life of this patent
Estimating the term…
Abstract
Extrusion processability of non-fluorinated melt-processable polymers is improved by introducing a fluoropolymer process aid by means whereby the weight average particle size of the fluoropolymer is greater than 2 microns as it reaches the extruder die entrance.
Claims29
An extrudable composition for passing through a die at an extrusion temperature, said composition comprising:
- A) a non-fluorinated melt processable polymer;
- B) 25 to 2000 parts per million by weight, based on total weight of the extrudable composition, of a fluoropolymer, said fluoropolymer having a weight average particle size greater than 2 microns and less than 10 microns, as measured at a point immediately preceding the die;
- and
- C) at least an effective amount of interfacial agent to achieve a fluoropolymer weight average particle size greater than 2 microns and less than 10 microns as measured at a point immediately preceding the die, but no more than a 5:1 weight ratio of interfacial agent to fluoropolymer, said interfacial agent being chemically distinct from both said non-fluorinated melt processable polymer and said fluoropolymer, and said interfacial agent having a melting point less than said extrusion temperature.
1 more element
A process aid masterbatch for use in an extrudable composition at an extrusion temperature, said process aid masterbatch comprising:
- A) a non-fluorinated melt processable polymer;
- B) 1 to 50 weight percent, based on total weight of the masterbatch, of fluoropolymer having a melting point less than said extrusion temperature, said fluoropolymer selected from the group consisting of i) fluoroelastomers having a Mooney viscosity, measured per ASTM D1646 at 121°C., large rotor, condition ML 1+10 minutes, of 60 to 80 and ii) semi-crystalline fluoropolymers having a melt index, measured per ASTM D1238, 265° C., 5 kg weight, between 0.5 and 3.0 dg/min;
- and
- C) at least an effective amount, to improve processability, of interfacial agent other than a poly(oxyalkylene) polymer, but no more than a 5:1 weight ratio of interfacial agent to fluoropolymer, said interfacial agent being chemically distinct from both said non-fluorinated melt processable polymer and said fluoropolymer, and said interfacial agent having a melting point less than said extrusion temperature.
1 more element
Dependencies are inferred from the claim text.