Analysis of Raw Materials
The analysis of the resins, pigments, solvents and additives that are used in the manufacture of paints and inks requires the use of a variety of techniques.
At the simplest, QA, level it can often suffice to use FTIR to obtain a “fingerprint” spectrum which can be compared with that of a reference material. If more detailed analysis is required, then GC-MS is an excellent method of separating and identifying the components of solvent blends. The same technique, used in conjunction with a pyrolyser, can be used to identify polymer resins and other involatile organic materials such as organic pigments.
The detailed analysis of inorganic pigments and extenders usually involves elemental analysis such as inductively coupled plasma-atomic emission spectroscopy (ICP-AES) or X-ray fluorescence spectrometry (XRF). There are some cases where the trace impurities in a sample can give useful information regarding its origin or can be used to confirm that a particular grade of material has been used. In such case we can extend elemental analysis to determine trace elements at part per million levels. In situations where even detailed elemental analysis does not provide a conclusive identification, then for crystalline materials, X-ray diffraction (XRD) can often provide the information required.