Abstract
In connection with the synthesis of heat-transfer printing dye, a number of new aminonaphthoquinone dyes were synthesized by the reaction of naphthazarin with butylamine in the presence of cupric chloride. Selective β-butylaminations predominantly proceeded by adding copper salts in the reaction mixtures.
Some spectral and dyeing properties of these new aminonaphthoquinone (NQ) dyes were studied in comparison with the corresponding anthraquinone (AQ) dyes. From the results of P. P. P. MO calculations of some amino-NQ, it was fo and that the first excitation was attributed to the intramolecular charge transfer transition from amino substituted benzene ring to P-quinone as the same as the cases of amino AQ dyes. The substitution of 8-butylamino group (2- or 6-position) to the 5, 8-bisbutylamino -1, 4-NQ, which absorbs in longer wavelength region of 36 nm than 1, 4-bisbutylamino AQ, causes the hypsochromic shift of 39 nm (2-position) and 66 nm (6-position), and loses the brightness in color because of the appearance of the second band at about 460 nm.
Dyeability on polyester and the fastness to light were almost the same as that of corresponding AQ dyes. Poor fastness to sublimation caused by the smaller molecular size than AQ dyes was proposed to be favourable for heat-transfer printing dyes.
