Spectrophotometric evaluation of pigmented urethane acrylate coating colour stability

Abstract

Abstract The research was carried out testing two red pigment dispersion colour stability in UV light-curing urethane acrylate composition. The given urethane acrylate composition was pigmented with a pigment content of 0.1% to 5%. Coating colour change was evaluated at room temperature and at 50°C over a 28-day period. For all prepared pigment samples, spectrometric colour difference measurements were performed using CIEL*a*b* and CIEL*C*h* colour systems and FTIR-ATR to evaluate their stability over time. The colour stability was improved with increasing pigment concentration. There was found the difference between tested red pigments and can be concluded that one of them are more stable for use in pigmented coatings.