Abstract:

In order to improve the yellowing resistance of polyurethane leather fabrics, the influence of light stabilizers on the yellowing resistance of polyurethane leather fabrics was investigated by analyzing the influence of UV light on the performance and appearance of polyurethane coating film. In addition, the optimized compound admixture ratio of light stabilizers depending on the analysis and evaluation of influence of color difference value on the level of leather color change was obtained. The related process conditions were optimized by studying the influence of processes such as stamping temperature, stamping time, washing and heat setting on the yellowing resistance of polyurethane leather fabrics. The results indicate that by adding light stabilizers into polyurethane leather fabrics, the aging rate of photoengraving could be dramatically reduced and the yellowing resistance could be enhanced. When the mass of hindered amine light stabilizer LS-622 is one third of that of UV absorber UV-531, the weight is 2.0%, the stamping temperature is 100 ℃ and the stamping time is 30 s, the anti-yellowing effect of brown polyurethane leather fabrics is optimized, and the level of color change is increased to level 2 with slight color change.

Key words: polyurethane, leather fabric, yellowing, coating, light stabilizer