Dielectric substrates comprising a polymide core layer and a high temperature fluoropolymer bonding layer, and methods relating thereto

A dielectric substrate useful for wrapping wire or cable or for supporting electronic circuitry, the substrate comprising:

• a. a polyimide layer having a thickness in a range between and including any two of the following thicknesses:
• 8, 10, 12, 15, 20, 25, 30, 40, 50, 60, 70, 75, 80, 90, 95, 100, 120, 125, 130, 135, 140, 145 and 150 microns;
• b. a high-temperature bonding layer having:
• i. a thickness between and including any two of the following numbers:
• 0.25, 0.5, 0.75, 1, 2, 3, 4, 5, 6, 8, 10, 12, 14, 16, 18, 20, 22 and 25 microns;
• ii. a melting point in a range between and including any two of the following temperatures:
• 220, 225, 230, 240, 250, 260, 270, 280, 290, 295, 300, 305, 310, 315 and 320° C.;
• and
• iii. the high-temperature bonding layer comprising a high temperature base polymer comprising poly(tetrafluoroethylene-co-perfluoro[alkyl vinyl ether]) (PFA) in a concentration range between and including any two of the following weight percentages (based upon the total amount of high temperature base polymer):
• 65, 70, 75, 80, 85, 90, 95, 96, 97, 98, 99 and 100;
• and optionally blended with poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP) in an amount in a range between (and including) any two of the following weight percentages (based upon total weight of high temperature base polymer):
• 0, 1, 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, and 45,
• c. an adhesive primer layer in contact with and positioned between the polyimide layer and the high-temperature bonding layer, the adhesive primer layer having an adhesive primer base polymer comprising about 70, 80, 90, 95, 96, 97, 98, 99, 99.5 or 100 weight percent poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP), optionally blended with a second copolymer selected from the group consisting of:
• polytetrafluoroethylene (PTFE), poly(tetrafluoroethylene-co-perfluoro[alkyl vinyl ether]) (PFA);
• poly(ethylene-co-tetrafluoroethylene) (ETFE) and derivations or copolymers thereof, and
• d. a polyimide-to-metal (“PTM”) bonding layer adjacent to the polyimide layer is on an opposite side of the high-temperature bonding layer, the polyimide-to-metal bonding layer comprising a base polymer comprising about 70, 80, 90, 95, 96, 97, 98, 99, 99.5 or 100 weight percent poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP), optionally blended with a second polymer selected from the group consisting of:
• polytetrafluoroethylene (PTFE), poly(tetrafluoroethylene-co-perfluoro[alkyl vinyl ether]) (PFA);
• poly(ethylene-co-tetrafluoroethylene) (ETFE) and derivations or copolymers thereof, wherein the polyimide-to-metal (PTM) bonding layer has a thickness between and including any two of the following numbers 0.25, 0.3, 0.4, 0.5, 0.75, 1, 2, 3, 4, 5, 10, 15, 20, 22 or 25 microns.