Replacement of Polyurethane Resin with Castor Oil-Based Alkyd Resin in Gloss Paint Production

Abstract

Polyurethane resins give an excellent paint film when cured. However, because of the unsteady and rising cost of polyfunctional di-isocyanate which is a chief component of polyurethanes, it is imperative that polyurethanes are replaced with other resins which are relatively cheaper while still maintaining the quality of the paint film. The quality of the film formed from the replacement of polyurethane resin with castor oil based alkyd resin was examined in this research. Pigment Volume Concentration concept of paint formulation was used to produce two samples (A and B) of 100 cm3 of gloss paints containing 45%, and 5% of polyurethane resin combined with 55% and 95% of alkyd resin respectively, and these were compared with a paint produced with only polyurethane resin (sample C). They were subjected to drying time, chemical resistance, solubility test, adhesion test and weathering test. Results from these tests showed that sample B had the shortest drying time, 0% adhesion failure, excellent weathering, solubility and chemical resistance. Hence, castor oil based alkyd resins are excellent film formers like their polyurethane counterpart and as such can be used as their replacement.