Analysis of Ink/Coating Penetration on Paper Surfaces by Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) in Conjunction with Principal Component Analysis (PCA)

Time-of-Flight Secondary ion mass Spectrometry (ToF-SIMS), in conjunction with Principal Component Analysis (PCA), has been used to characterize the spatial distribution of the chemical components of ink, both on the surface and in the Z-direction of coated papers. Preliminary work was performed on commercial ink-jet printing paper and on commercially available photopaper to establish that ToF-SIMS, in conjunction with PCA, could help characterise ink/coating distribution. To illustrate further that ToF-SIMS/PCA could differentiate the individual components making up the ink, pigment-based and dye-based inks were applied to two coated papers (PCC + SA and PCC + starch + PVA) using an inkjet printer. This approach shows that high spatially resolved images obtained by ToF-SIMS allows a depth profile to be obtained, thereby allowing the correlation between ink distribution at the surface and in the Z-direction to be evaluated in relation to the coating formulation.