DETERMINATION OF CAUSES OF COEFFICIENT OF FRICTION INCREASES IN PE/PETLAMINATES USING TIME-OF-FLIGHT SECONDARY ION MASS SPECTROMETRY

摘要

The Coefficient of Friction (COF) of PE/PET laminates is critical to their performance in packaging applications.Occasionally, the COF of these films can unexpectedly increase when they are stored. The COF of the film iscontrolled primarily by the SLIP additives that have been deliberately blended into the film. In order to fullyunderstand why a given film has an acceptable or unacceptable COF, one must identify the total SLIP content of thefilm, the location of the SLIP within the film, and the type of SLIP present in the film. Furthermore, since othercomponents of the film may interfere with the SLIP, it is often necessary to fully characterize the film to identify thefactors that alter the behavior of the SLIP. Several techniques are available for SLIP analysis, including extraction(coupled with FTIR, GC, HPLC and/or NMR), and Attenuated Total Internal Reflectance FTIR (ATR). However,these techniques are often insufficient to generate a complete picture in order to solve a COF problem. Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) can be used to identify and quantify the SLIP present, mapthe distribution of the SLIP, and map the construction of the complete film. In this manner, this technique can beused to identify the root cause of the COF problem. In this case, the ToF-SIMS identified the root cause as mixing ofthe urethane adhesive used in the lamination into the PET layer. The mixed urethane/PET layer interacts with theSLIP at the surface to redistribute the SLIP into the mixed layer, reducing the COF of the film.