Blended fluoropolymer compositions and coatings for flexible substrates

1. A fluoropolymer composition, comprising:

a fluoropolymer base component comprising at least one fluoropolymer including high molecular weight polytetrafluoroethylene (HPTFE) having a number average molecular weight (M n ) of at least 500,000, said at least one fluoropolymer base component present in an amount of between 82 wt. % and 96 wt. % based on the total solids weight of all fluoropolymers in said composition; and

a blended fluoropolymer composition present in an amount of between 4 wt. % and 18 wt. % based on the total solids weight of all fluoropolymers in said composition, said blended fluoropolymer composition comprising:

at least one low molecular weight polytetrafluoroethylene (LPTFE) having a first melt temperature (T m ) of 335° C. or less, and a mean particle size of 1.0 microns (μm) or less; and

at least one melt-processible fluoropolymer (MPF); and

said composition is in the form of an aqueous dispersion.

2. The composition of claim 1 , wherein said at least one melt-processible fluoropolymer comprises perfluoroalkoxy (PFA) present in an amount between 37 wt. % and 65 wt. % based on the total solids weight of said fluoropolymers in said blended fluoropolymer composition.

3. The composition of claim 2 , wherein said at least one melt-processible fluoropolymer comprises perfluoroalkoxy (PFA) present in an amount between 50 wt. % and 60 wt. % based on the total solids weight of said fluoropolymers in said blended fluoropolymer composition.

4. The composition of claim 1 , wherein said at least one melt-processible fluoropolymer comprises fluorinated ethylene propylene (FEP) present in an amount between 20 wt. % and 85 wt. % based on the total solids weight of said fluoropolymers in said blended fluoropolymer composition.

5. The composition of claim 4 , wherein said at least one melt-processible fluoropolymer comprises fluorinated ethylene propylene (FEP) present in an amount between 50 wt. % and 75 wt. % based on the total solids weight of said fluoropolymers in said blended fluoropolymer composition.

6. The composition of claim 1 , wherein said low molecular weight polytetrafluoroethylene (LPTFE) has a mean particle size of 0.9 microns (μm) or less.

7. The composition of claim 1 , wherein said low molecular weight polytetrafluoroethylene (LPTFE) has a first melt temperature (T m ) of 332° C. or less.

8. The composition of claim 1 , wherein said low molecular weight polytetrafluoroethylene (LPTFE) is obtained via emulsion polymerization without being subjected to agglomeration, thermal degradation, or irradiation.

9. The composition of claim 1 , wherein said low molecular weight polytetrafluoroethylene (LPTFE) is an LPTFE micropowder obtained via emulsion polymerization or suspension polymerization with or without a subsequent molecular weight reduction step.

10. The coating composition of claim 1 , wherein said fluoropolymer base component is present in an amount of between 85 wt. % and 95 wt. % and said blended fluoropolymer composition is present in an amount of between 5 wt. % and 15 wt. % based on the total solids weight of all fluoropolymers in said coating composition.

11. The coating composition of claim 1 , wherein said fluoropolymer base component is present in an amount of between 90 wt. % and 95 wt. % and said blended fluoropolymer composition is present in an amount of between 5 wt. % and 10 wt. % based on the total solids weight of all fluoropolymers in said coating composition.

12. The coating composition of claim 1 , wherein said at least one melt-processible fluoropolymer (MPF) comprises perfluoroalkoxy (PFA), said fluoropolymer base component is present in an amount of between 85 wt. % and 95 wt. % and said blended fluoropolymer composition is present in an amount of between 5 wt. % and 15 wt. % based on the total solids weight of all fluoropolymers in said coating composition.

13. The coating composition of claim 1 , wherein said at least one melt-processible fluoropolymer (MPF) comprises perfluoroalkoxy (PFA), said fluoropolymer base component is present in an amount of between 90 wt. % and 95 wt. % and said blended fluoropolymer composition is present in an amount of between 5 wt. % and 10 wt. % based on the total solids weight of all fluoropolymers in said coating composition.

14. The coating composition of claim 1 , wherein said at least one low molecular weight polytetrafluoroethylene (LPTFE) is present in an amount between 40 wt. % and 60 wt. % and said at least one melt-processible fluoropolymer (MPF) is present in an amount of between 40 wt. % and 60 wt. % based on the total solids weight of said at least one LPTFE and said at least one MPF.

15. The coating composition of claim 1 , wherein said at least one low molecular weight polytetrafluoroethylene (LPTFE) is present in an amount between 45 wt. % and 55 wt. % and said at least one melt-processible fluoropolymer (MPF) is present in an amount of between 45 wt. % and 55 wt. % based on the total solids weight of said at least one LPTFE and said at least one MPF.

16. The coating composition of claim 1 , wherein said at least one melt-processible fluoropolymer (MPF) comprises perfluoroalkoxy (PFA), said at least one low molecular weight polytetrafluoroethylene (LPTFE) is present in an amount between 40 wt. % and 60 wt. % and said PFA is present in an amount of between 40 wt. % and 60 wt. % based on the total solids weight of said at least one LPTFE and said PFA.

17. The coating composition of claim 1 , wherein said at least one melt-processible fluoropolymer (MPF) comprises perfluoroalkoxy (PFA), said at least one low molecular weight polytetrafluoroethylene (LPTFE) is present in an amount between 45 wt. % and 55 wt. % and said PFA is present in an amount of between 45 wt. % and 55 wt. % based on the total solids weight of said at least one LPTFE and said PFA.

18. The coating composition of claim 1 , wherein said at least one melt-processible fluoropolymer comprises perfluoroalkoxy (PFA) present in an amount between 43 wt. % and 63 wt. %, based on the total solids weight of said fluoropolymers in said blended fluoropolymer composition.

19. The coating composition of claim 1 , wherein said at least one melt-processible fluoropolymer comprises perfluoroalkoxy (PFA) present in an amount between 50 wt. % and 60 wt. %, based on the total solids weight of said fluoropolymers in said blended fluoropolymer composition.

20. The coating composition of claim 1 , wherein said at least one low molecular weight polytetrafluoroethylene (LPTFE) has a mean particle size of 0.75 microns (μm) or less.

21. The coating composition of claim 1 , wherein said at least one low molecular weight polytetrafluoroethylene (LPTFE) has a mean particle size of 0.5 microns (μm) or less.

22. The coating composition of claim 1 , wherein said at least one low molecular weight polytetrafluoroethylene (LPTFE) has a mean particle size of 0.2 microns (μm) or less.

23. The coating composition of claim 1 , wherein said at least one low molecular weight polytetrafluoroethylene (LPTFE) has a first melt temperature (T m ) of 329° C. or less.

24. The coating composition of claim 1 , wherein said at least one low molecular weight polytetrafluoroethylene (LPTFE) has a first melt temperature (T m ) of 327° C. or less.

25. The coating composition of claim 1 , wherein said at least one low molecular weight polytetrafluoroethylene (LPTFE) has a first melt temperature (T m ) of 325° C. or less.

26. The coating composition of claim 1 , wherein said at least one high molecular weight polytetrafluoroethylene (HPTFE) includes a modifying co-monomer in an amount less than 1 wt. % based on the weight of said high molecular weight polytetrafluoroethylene (HPTFE).

27. The coating composition of claim 26 , wherein said modifying co-monomer is perfluoropropylvinyl ether (PPVE).

28. The coating composition of claim 1 , wherein:

said at least one melt-processible fluoropolymer (MPF) comprises perfluoroalkoxy (PFA), said fluoropolymer base component is present in an amount of between 85 wt. % and 95 wt. % and said blended fluoropolymer composition is present in an amount of between 5 wt. % and 15 wt. % based on the total solids weight of all fluoropolymers in said coating composition;

said at least one high molecular weight polytetrafluoroethylene (HPTFE) includes a modifying co-monomer in an amount less than 1 wt. % based on the weight of said high molecular weight polytetrafluoroethylene (HPTFE); and

said at least one low molecular weight polytetrafluoroethylene (LPTFE) is obtained via emulsion polymerization and without being subjected to agglomeration, thermal degradation, or irradiation, and has a mean particle size of 1.0 microns (μm) or less.

29. The coating composition of claim 28 , wherein said at least one low molecular weight polytetrafluoroethylene (LPTFE) has a first melt temperature (T m ) of 329° C. or less.

30. The coating composition of claim 28 , wherein said at least one low molecular weight polytetrafluoroethylene (LPTFE) has a mean particle size of 0.5 microns (μm) or less.

31. The coating composition of claim 1 , wherein:

said at least one melt-processible fluoropolymer (MPF) comprises perfluoroalkoxy (PFA), said at least one low molecular weight polytetrafluoroethylene (LPTFE) is present in an amount between 45 wt. % and 55 wt. % and said PFA is present in an amount of between 45 wt. % and 55 wt. % based on the total solids weight of said at least one LPTFE and said PFA;

said at least one high molecular weight polytetrafluoroethylene (HPTFE) includes a modifying co-monomer in an amount less than 1 wt. % based on the weight of said high molecular weight polytetrafluoroethylene (HPTFE); and

said at least one low molecular weight polytetrafluoroethylene (LPTFE) is obtained via emulsion polymerization and without being subjected to agglomeration, thermal degradation, or irradiation, and has a mean particle size of 1.0 microns (μm) or less.

32. The coating composition of claim 31 , wherein said at least one low molecular weight polytetrafluoroethylene (LPTFE) has a first melt temperature (T m ) of 329° C. or less.

33. The coating composition of claim 31 , wherein said at least one low molecular weight polytetrafluoroethylene (LPTFE) has a mean particle size of 0.5 microns (μm) or less.

34. A fluoropolymer composition, comprising:

at least one high molecular weight polytetrafluoroethylene (HPTFE) having a number average molecular weight (M n ) of at least 500,000 and present in an amount of between 75 wt. % and 96 wt. % based on the total solids weight of all fluoropolymers in said composition, said at least one high molecular weight polytetrafluoroethylene (HPTFE) includes a modifying co-monomer in an amount less than 1 wt. % based on the weight of said high molecular weight polytetrafluoroethylene (HPTFE);

at least one low molecular weight polytetrafluoroethylene (LPTFE) having a first melt temperature (T m ) of 335° C. or less; and

at least one melt-processible fluoropolymer (MPF), wherein;

said at least one LPTFE and said at least one MPF are together present in an amount of between 4 wt. % and 25 wt. % based on the total solids weight of all fluoropolymers in said composition;

said at least one melt-processible fluoropolymer (MPF) comprises perfluoroalkoxy (PFA), said at least one low molecular weight polytetrafluoroethylene (LPTFE) is present in an amount between 40 wt. % and 60 wt. % and said PFA is present in an amount of between 40 wt. % and 60 wt. % based on the total solids weight of said at least one LPTFE and said PFA; and

said composition is in the form of an aqueous dispersion.

35. The coating composition of claim 34 , wherein said modifying co-monomer is perfluoropropylvinyl ether (PPVE).

36. The coating composition of claim 34 , wherein said at least one melt-processible fluoropolymer (MPF) comprises perfluoroalkoxy (PFA), said at least one low molecular weight polytetrafluoroethylene (LPTFE) is present in an amount between 45 wt. % and 55 wt. % and said PFA is present in an amount of between 45 wt. % and 55 wt. % based on the total solids weight of said at least one LPTFE and said PFA.

37. The coating composition of claim 34 , wherein said at least one low molecular weight polytetrafluoroethylene (LPTFE) has a mean particle size of 0.75 microns (μm) or less.

38. The coating composition of claim 34 , wherein said at least one low molecular weight polytetrafluoroethylene (LPTFE) has a mean particle size of 0.5 microns (μm) or less.

39. The coating composition of claim 34 , wherein said at least one low molecular weight polytetrafluoroethylene (LPTFE) has a mean particle size of 0.2 microns (μm) or less.

40. The coating composition of claim 34 , wherein said at least one low molecular weight polytetrafluoroethylene (LPTFE) has a first melt temperature (T m ) of 329° C. or less.

41. The coating composition of claim 34 , wherein said at least one low molecular weight polytetrafluoroethylene (LPTFE) has a first melt temperature (T m ) of 327° C. or less.

42. The coating composition of claim 34 , wherein said at least one low molecular weight polytetrafluoroethylene (LPTFE) has a first melt temperature (T m ) of 325° C. or less.

43. A method of applying a coating to a flexible substrate, said method comprising the step of:

applying the fluoropolymer composition of claim 34 to a flexible substrate.

44. A method of forming a powder, comprising the step of:

drying the fluoropolymer composition of claim 34 .