• Textile Coloration and Finishing
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• v.27 no.1
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• pp.27-34
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• 2015

Novel super hydrophobic disazo red dyes were synthesized to improve light fastness of the primary monoazo red dye of previous study on polyolefin fibers such as polypropylene and ultra high molecular weight polyethylene fibers. 4-Alkylanilines were diazotized and then coupled to 2,5-dimethylaniline to produce dye intermediates which were then further used to synthesize final disazo red dyes by diazoization and coupling to ${\beta}$-naphthol. Considering both affinity of the dyes toward both polyolefin fibers and color fastnesses, the decyl-substituted dye was determined as the optimum dye. The decyl-substituted disazo red dye exhibited good dyeability on both polyolefin fibes and almost the same color values as the previous primary monoazo red dye. Light fastness on ultra high molecular weight polyethylene fibers was improved up to rating 3~4 compared to rating 2~3 of the previous primary monoazo red dye.

• Fibers and Polymers
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• v.3 no.4
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• pp.147-152
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• 2002

Copper (II) salts are used as metallizing agents in the synthesis of new non-genotoxic direct dyes for cotton. Specifically, cotton fabric is dyed with non-genotoxic disazo direct dyes and then treated with copper salts. The complexes are characterized by neutron activation analysis, absorption spectrometry and standard Salmonella mammalian mutagenicity assay, and the after-treated fabrics are evaluated for lightfastness and washfastness. Direct dyes possessing ortho-propoxy and ortho'-hydroxy substituted systems formed the corresponding nonmutagenic 1:2 dye:metal complex and undergo significant improvement in lightfastness following metallization.

• Textile Coloration and Finishing
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• v.15 no.2
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• pp.86-92
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• 2003

It is already known that the color of wool fabric dyed with disazo acid dyes could be changed in dyeing process and this is accelerated under alkaline condition. Focus was given to figuring out the mechanism of this color change, through the LC-MS analysis. In this study, no color change was seen in wool fabrics dyed with C. I. Acid Blue 113 under weak acidic, neutral and weak alkaline conditions for 1hour. However, the wool fabrics dyed under weak alkaline condition for a long time over 3 hours fumed reddish orange. When the wool fabrics dyed under weak acidic, neutral and weak alkaline conditions were treated with $0.5g/L\;Na_2C0_3$ solution, all of them turned reddish orange. On the other hand, the color of silk fabrics dyed with C. I. Acid Blue 113 were not changed after the same alkaline treatment. Wool contains cystine and cysteine, whereas silk does not. Due to the reversible reduction/oxidation process of cystine and cysteine in wool dyeing, the C. I. Acid Blue 113 of the dis-azo type is decomposed by reduction and consequently turned them into the reddish orange mono-azo types dye.

• Textile Coloration and Finishing
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• v.8 no.1
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• pp.8-14
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• 1996

In resist-discharge printing of cotton fabrics with reactive/reactive dyes the effects of both resist agents, benzaldehyde sodium bisulfite(BASB) and glyoxal sodium bisulfite (GSB), and Rongalite on the resist-discharge behaviors of C.I. Reactive Black 5(B1-5), which is disazo type and has two vinylsulfone groups, were investigated. It was confirmed that BASB and GSB were effective resist agents, and about 4% of BASB or about 6% of GSB was proper to obtain successful white or colored resist-discharge results. It was thought that the good resist-dischargeability of BASB was due to the hydrophobicity of bezene in BASB, and also that of GSB resulted from the structural effects caused by two hydroxy groups in GSB and the ease of washing of unactivated reactive dye. Only 5% Rongalite without any resist agents showed good resist-discharge result, but 1~3% Rongalite with 4% BASB brought about the stain of cotton fabric by reddish monoazo products produced by insufficient cleavage of two azo groups in Bl-5.