Synthesis, spectral properties and application of novel monoazo disperse dyes derived from N-ester-1,8-naphthalimide to polyester

A series of novel monoazo disperse dyes based on N-ester-1,8-naphthalimides were synthesized using 4-amino-N-methylglycinate-1,8-naphthalimide and 4-amino-N-ethylglycinate-1,8-naphthalimide, as diazo components, with various couplers. The spectrophotometric properties of the dyes were examined in different solvents and their solvatochromism effects were investigated. The dyes displayed λmax of between 515 and 563 nm and the molar extinction coefficient of the dyes varied from 25,863 to 49,080 l mol−1 cm−1. Most of the dyes showed acceptable build up properties on polyester fibres under high temperature conditions and displayed moderate light fastness and very good wash and dry heat fastness on polyester fibres. The results indicated that the presence of an ester group within the dye molecule provided alkali-clearable potential.