Substituent effects on the photofading of disperse azo dyes on poly(ethylene terephthalate) substrate

作者：Okada Yasuyo^*; Hihara Toshio; Hirose Mie; Morita Zenzo

来源：Coloration Technology, 2010, 126(3): 127-139.

DOI：10.1111/j.1478-4408.2010.00237.x

The relationships between the chemical structures and oxidative fading of the disperse azo dyes, p-nitrophenylazo- and benzothiazoleazo-anilines, on poly(ethylene terephthalate) substrate are discussed in terms of the parameters k(0,i) (rate constants of reaction towards 1O(2)) and f(i) (photosensitivity), the molecular parameters of molecular orbital theory and substituents in the diazo and coupling components, on the assumption that the initial rates of oxidative fading are proportional to the product of k(0,i) and f(i). 2-Methoxy-5-acetylamino-N-substituted aniline couplers exhibited large f(i) values. 2-Chloro and 4-nitro substituents of aniline diazo components exhibited small f(i) values or high quantum yields of internal conversion, while 4-nitro substituent did not. A close correlation between N-substituents and light fastness, proposed by Muller and supplemented by Dawson, demonstrates the applicability of frontier orbital theory, through the highest occupied molecular orbital (HOMO) energy of the dyes, to the analysis of oxidative fading. Dyes with N-2-cyanoethyl substituents, which gave a lower HOMO energy, also exhibited superior light fastness compared with N-2-hydroxyethyl substituents.

• 出版日期2010