Synthesis of Some Azo Disperse Dyes from 1-Substituted 2-Hydroxy-6-pyridone Derivatives and Their Colour Assessment on Polyester Fabric

Abstract

The synthesis of a series of 3-(p-substituted phenylazo)-6-pyridone dyes which is suitable for the dyeing of polyester fabrics, is described. Visible absorption spectra of the dyes were examined in various solvents and the compounds in solution exhibited hydrazone-common anion equilibrium. The electronic absorption spectra cover a λ max range of 404-464 nm in DMF at uniformly high absorption intensity between 5.33 × 10 4-8.55 × 10 4 l•mol-1 •cm-1 and gave bright intense hues of yellow to orange on polyester fabrics. The colour parameters of the dyed fabrics were measured and the dyes have excellent exhaustion between 72%-79% for polyester fabrics, more intense and of very good fastness properties on polyester fabrics. The remarkable degree of levelness and brightness after washing is indicative of good penetration and excellent affinity of these dyes for the polyester fabric.

Experimental and theoretical insight into the electronic properties of 4‐aryl‐5‐arylazo‐3‐cyano‐6‐hydroxy‐2‐pyridone dyes

“…Disperse azo-pyridone dyes give bright hues and are suitable for dyeing of polyester fabrics [9]. The physicochemical properties of these dyes are closely related to their tautomerism.…”

Arylazoazines and arylazoazoles as interesting disperse dyes: Recent developments with emphasis on our contribution laboratory outcomes

“…These compounds have two tautomeric forms, and in solution there is a very fast equilibration between them [49]. Sakoma et al [50] has also reported three component condensations of ethyl cyano acetate, primary amines, and ethyl acetoacetate without catalyst. The yields of the obtained products 19o-q ranged from 86 to 91%.…”

“…The bright hue might be attributed to the high planarity of the pyridone ring, because of the lower steric interaction of a five membered ring. The remarkable degree of levelness and brightness after washing is indicative of good penetration and the excellent exhaustion of these dyes for the polyester fabric due to the accumulation of polar groups [50].…”

“…Pyridones 19a-q could be readily coupled with aromatic and heteroaromatic diazonium salts affording the corresponding aryl and heteroaromatic azopyridones 21a-t (Table 4). Sakoma et al [50] and Ashkar et al [51] have evaluated 3-(p-substituted phenylazo)-6-pyridone dyes 21a-d and 21j-t as disperse dyes on polyester fabrics in order to examine the influence of substituent on the color of the prepared dyes. Sakoma et al concluded that the exhaustion of the dyes was very good on polyester fabric with excellent wash and light fastness properties.…”

Synthesis and Application of Azo Disperse Reactive Dyes derived from p-Aminobenzaldehyde

“…In the conventional disperse dyeing of polyester, dispersing agents are usually added to increase the dispersion stability and solubility of disperse dyes. However, after the dyeing process is finished, they are not adsorbed onto polyester and discharged as effluents with the residual dyeing liquor, which increases the COD and BOD values of the effluent [3][4] . It is widely known that the presence of an aldehyde group in a dye molecule renders the dye capable of reacting with the free functional groups of the wool keratin, or with the hydroxyl group of the cellulose [5][6] .…”