Process aid for melt processable polymers
View Patent ↗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.
1. A fluoropolymer process aid composition comprising a) fluoropolymer and b) polycaprolactone having a number average molecular weight in the range of 2000 to 10000.
2. A composition of claim 1 wherein said composition has a weight ratio of polycaprolactone to fluoropolymer of up to 5:1.
3. A composition of claim 1 wherein said polycaprolactone has a number average molecular weight between 2000 and 4000.
4. A composition of claim 1 wherein said fluoropolymer is a fluoroelastomer comprising a copolymer of vinylidene and a comonomer selected from the group consisting of hexafluoropropylene, chlorotrifluoroethylene, 1-hydropentafluoropropylene, 2-hydropentafluoropropylene and tetrafluoroethylene.
5. A composition of claim 1 wherein said fluoropolymer is a semi-crystalline fluoropolymer selected from the group consisting of poly(vinylidene fluoride), tetrafluoroethylene homopolymer, a copolymer of tetrafluoroethylene and hexafluoropropylene and a copolymer of tetrafluoroethylene and propylene.
6. A composition of claim 1 wherein said fluoropolymer is a fluoroelastomer comprising a copolymer of tetrafluoroethylene and propylene.