Deposition of ethylene-hexafluoropropene gradient plasma-copolymer using dielectric barrier discharge reactor at atmospheric pressure: Application to release coatings on pressure-sensitive tape

Plasma-polymerized hexafluoropropene (PPHFP) film deposited using a dielectric barrier discharge reactor at atmospheric pressure had low enough adhesive strength, 22.2 Nm(-1), for use as a release coating of pressure-sensitive adhesive tapes, but the bond strength between PPHFP film and a poly (ethylene terephthalate) (PET) substrate film was slightly weak: some part of the PPHFP deposits could be peeled from the PET substrate. Since the XPS results indicated that the bond strength between plasmapolymerized ethylene (PPE) film and PET substrate was strong enough, we tried to deposit PPE and plasma-polymerized ethylene - hexafluoropropene gradient plasmacopolymer between the PET substrate and the PPHFP film. This multi-layer film (MLF) had low enough adhesive strength, 36.6 Nm(-1), for use as the release coating; this value was near that of a control sample, Teflon sheet, 21.6 Nm(-1). Moreover, the bond strength between MLF and PET substrate became stronger than that between PPHFP and PET films.