Investigation of Synthesis and Dyeing Properties of Some Azonaphthalimide Disperse Dyestuffs for the Dyeing of Polyester Fibres

Unmodified polyester fibres can only be dyed with disperse dyestuffs either with the aid of carriers at 1000 e (no longer desirable due to environmental limitations), or at elevated temperatures (1300 e for the exhaustion processes and 2100 e for the thermosol processes). The economical production of wash-fast, light-fast and sublimation- fast, red and bluish-red dyeings on polyester fibres with azo disperse dyestuffs is not easily achievable. The aim of the present study was to synthesize new dyestuffs based on various 4-aminonaphthalimide derivatives in order to achieve the above mentioned goals. The use of various 4-aminonaphthalimide derivatives as diazo components and ~-naphthol as the coupling component gave a series of bright red dyeings on polyester fibres. The use of N,N-diethyl-m-toluidine as a coupling component together with the same diazo components gave bright bluish-red dyeings on polyester fibres. Using Npropyl- 4-aminonaphthalimide as an azo component and p-amino acetophenone as a coupling component gave a yellowish-cream dyed polyester fibres. Spectrophotometric studies on polyester fibres, showed that the attained dyeings had good tinctorial strength and high colour build up on polyester fibres. The dyeings also gave perfect wash fastnesses, very good to excellent sublimation fastnesses and very good light fasstnesses.