Performance Evaluation of Local Clay-Extender Pigment on Alkyd Paint Formulations

The performances of Nsu clay extender pigment in alkyd paint formulations have been studied. Xylene was used as the solvent while TiO2 formulated alkyd paint sample served as a reference in this study. The three particle sizes of the clay used in this study are 0.075, 0.15, and 0.30 mm. The physic-mechanical properties of the paint samples were evaluated according to ASTM. The study showed that paints formulated with Nsu clay had higher viscosities which increased with increases in clay contents at any clay particle size investigated while 100 % TiO2 formulated alkyd paint had the least paint viscosity. The specific gravities of the formulated alkyd paint samples decreased with increases in clay contents and clay particle sizes. The 100 % TiO2 formulated alkyd paint had the highest specific gravity. The drying properties of the paint samples were generally good. The alkyd paint formulated with 0.075 mm clay particle size had low drying times than those formulated with 0.15 and 0.30 mm clay particle sizes at any clay content. The dry film thickness of the formulated paint samples were in the range of 0.29 – 0.39. The dry paint film hardness of the formulated alkyd paints increased with increases in clay contents at the three clay particle sizes studied. With the exception of TiO2 formulated paint sample which exhibited no settling tendency, the formulated paint samples exhibited moderate settling tendencies for 0.075 mm clay particle size when compared with the other clay particle sizes. There was no mildew formation observed on all the paint samples after exposure to rain and sunlight for eight months. There was no evidence of rust in all the formulated paint samples. Generally, all the paint samples exhibited good resistance to distilled water, 3 % H2SO4, and Na2CO3. All the formulated paint samples were affected on 3 % NH3 immersion which resulted to wrinkles, with the larger particle sized clay adversely affected. The performance characteristics obtained from the formulated paint samples with the indigenous Nsu clay has highlighted the improved paint properties obtainable with the local clay which should justify their utilization in the surface coatings industries for a variety of different applications