Synthesis and salt‐free dyeing characteristics of cationic reactive dyes containing polyetheramine segments

A series of cationic reactive dyes containing both quaternary ammonium and polyetheramine as soluble groups and monochlorotriazine as a reactive group have been synthesised and applied to cellulose fibre by salt‐free exhaust dyeing. Investigation of the synthesis method and dyeing properties of these cationic reactive dyes showed that the best pH value for these dyes is 6, and also that these cationic reactive dyes give a high substantivity to cellulose. In the salt‐free dyeing process, their adsorption was consistent with the Langmuir isotherm during the primary exhaustion stage, but in the secondary exhaustion stage the adsorption was in accordance with the Freundlich isotherm, and their secondary exhaustion reached up to 96% and above. Moreover, the degree of fixation, the levelling, and the transfer properties on cotton fabric were good. Light fastness reached grade 5–6, washing, perspiration, and dry rubbing fastness reached grade 4 and above, but wet rubbing fastness reached only grade 3–4.     

A study of novel bisazo reactive red dyes with good wet fastness

Three series of bisazo reactive red dyes were synthesised using 6‐amino‐1‐naphthol‐3‐sulphonic acid and its derivatives as the coupling components. The dyeing parameters and wash fastness of these dyes on knitted cotton were evaluated and the relationships between the structure and dyeing properties were investigated. It was found that the hydrophilic groups introduced into the dye molecules decrease the substantivity and fixation of the dyes, but increase the build‐up and migration properties. The defined wash‐off factor can directly reflect the wash fastness of the dyes and the build‐up property can be improved by commercialisation using certain auxiliaries. The results indicate that there is the possibility of synthesising a red reactive dye with a satisfying balance between high fixation and good wash fastness and several such dyes have been developed.     

Pretreatment of cotton fabrics with polyamino carboxylic acids for salt‐free dyeing of cotton with reactive dyes

In this study, polyamino carboxylic acids have been used to improve the dyeability of cotton in a salt‐free reactive dyeing process. These polyamino carboxylic acids were prepared by partial carboxylation of polyvinylamine. Cotton fabric was pretreated with polyamino carboxylic acids and dyed with reactive dyes. The colour strengths of the dyed fabrics were evaluated by measuring the K/S values. The fastness properties (washing, rubbing and light fastness) of the dyed cotton fabrics were also measured. The pretreatment of cotton with polyamino carboxylic acids creates positive charges on the fabric surface. In this way, salt‐free reactive dyeing of cotton or dyeing with only a small amount of electrolyte is possible.     

Application of phthalimide-based alkali-clearable azo disperse dyes on polyester and polyester/cotton blends

Phthalimide-based alkali-clearable azo disperse dyes were synthesised and applied to polyester and polyester/cotton blends. These dyes have an alkali-clearable property that enables alkaline treatment to be substituted for conventional reduction clearing. Therefore, by using these dyes, it is possible to avoid generating dyehouse effluents with high BOD values and carcinogenic aromatic amines that may, in some cases, be liberated by reduction clearing. In addition, polyester/cotton blends can be dyed by a one-bath, two-step dyeing method, as alkali clearability enables the disperse and reactive dyes to be used in the same bath. The dyeing behaviour and fastness properties of these dyes have been investigated. In particular, the cross-staining of cotton was studied to estimate the suitability of the dyes synthesised for dyeing polyester/cotton blends.     

One‐bath dyeing of polyester/cotton blends with disperse and bis‐3‐carboxypyridinium‐s‐triazine reactive dyes. Part 2: Application of substantive reactive dyes to cotton at 130 °C and neutral pH†

An earlier paper reported that the reactive dyes (not the disperse dyes) were responsible for the inability to achieve heavy depths of shade, when dyeing polyester/cotton blends by a one‐bath process at 130 °C and neutral pH using reactive dyes containing a 3‐carboxypyridinium‐s‐triazinyl group. It was shown that the poor colour yield of the bis‐3‐carboxypyridinium‐s‐triazine reactive dyes was because of their low exhaustion level at 130 °C and pH of 7.0–7.5. We now report the synthesis and evaluation of some bis‐3‐carboxypyridinium‐s‐triazine reactive dye structures, possessing highly substantive chromophores, as a means of obtaining high colour yield, on 100% unmercerised cotton, under the specified dyeing conditions. The technical performance of these dyes under such conditions was compared with that of selected Novacron (Cibacron) LS and Procion H‐E dyes, applied under their recommended (atmospheric) dyeing conditions.     

Studies involving reactive dyes containing a benzophenone ultraviolet absorber

Nine new fibre reactive dyes containing a built‐in hydroxybenzophenone moiety were synthesised, characterised using electrospray mass spectroscopic analysis, applied to cotton fabrics and the ultraviolet protection factor values of the dyed cotton fabrics determined. The results showed that the anti‐ultraviolet properties of cotton were improved by dyeing with dyes containing a built‐in hydroxybenzophenone moiety, but that the benzophenone ultraviolet absorber need not be covalently linked to dye molecules to provide significant benefit.     

Application of polycarboxylic acid sodium salt in the dyeing of cotton fabric with reactive dyes

In this study, the effects of polycarboxylic acid sodium salt on the dyeing of cotton with reactive dyes were evaluated by measuring and comparing the K/S values and dyeing fastnesses of the dyed cotton fabric samples. Results showed that the K/S value and dyeing fastness of cotton fabrics dyed with polycarboxylic acid sodium salt, substituting inorganic salts as exhausting agent were close to that of with sodium chloride when dip‐dyeing process was used. While, in pad‐dry dyeing, the K/S value of cotton fabric samples dyed with polyacid salts as exhausting agent was higher than that of with sodium sulfate, and the dyeing fastnesses of these samples were nearly the same. The dyeing mechanism of cotton fabric with reactive dye, using polycarboxylic acid sodium salt as exhausting agent was analyzed. The dyeing exhausting mechanism of reactive dye seems different when the inorganic salt and polycarboxylic acid sodium salt were used as exhausting agent in the dyeing of cotton fabric with reactive dye. The polycarboxylic acid sodium salt, as weak electrolyte, increased the dye‐uptake of reactive dye on cotton fabric not only by screening negative charges on cotton surface, but also by the effect of salting‐out or hydrophobic combination. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Synthesis and application of yellow azo‐anthraquinone disperse dyes for polylactide fibres

1‐Phenyl‐3‐methyl‐5‐pyrazolonyl azo‐anthraquinone dyes having high light fastness on polylactide fibres were synthesised from 1‐aminoanthraquinone via a diazotisation‐coupling reaction with 1‐phenyl‐3‐methyl‐5‐pyrazolones. The structures of these new dyes were confirmed using mass spectrometry, infrared and proton nuclear magnetic resonance spectroscopy and combustion analyses. Their dyeing behaviour on polylactide fibres was also determined, whereupon it was found that the title dyes could be applied at a relatively low dyeing temperature and that the corresponding dyed fabrics had good fastness properties.     

Synthesis and dyeing properties of polyvinylamine dyes for cotton

Novel polyvinylamine dyes were designed and synthesised from poly(N‐vinylformamide‐co‐vinylamine) and reactive dyes, then used to dye cotton fibres by the dip‐pad‐steam process, with the dyeing methods being examined in detail. Each polyvinylamine dye was fixed to cotton without a crosslinking agent through covalent bonds formed between the reactive group of the dye and the cotton fibres. A fixation of 99% was achieved, with grades of 4 and 4‐5 wash and dry‐rub fastness, respectively.     

Synthesis of an amino-terminated hyperbranched polymer and its application in reactive dyeing on cotton as a salt-free dyeing auxiliary

A water-soluble amino-terminated hyperbranched polymer was synthesised from methyl acrylate and diethylene triamine by melt polycondensation. Its molecular weight and possible structure were characterised by gel permeation chromatography, Fourier transform infrared spectrophotometry and nuclear magnetic resonance spectroscopy. The zeta potential of cotton fabrics treated with the aqueous solution of the amino-terminated hyperbranched polymer (6 g dm⁻³) in the presence of citric acid (2 g dm⁻³) and sodium hypophosphite (3 g dm⁻³) of the liquid phase is positive at pHs lower than 7.5. Dyed with reactive dyes, the treated cotton fabric displayed a markedly enhanced colour strength, even when dyeing had been carried out in the absence of the electrolyte. The washing fastness, rubbing fastness and levelling properties of the dyed, treated cotton fabrics were also good compared with that obtained by conventional dyeing. The dyeing behaviour of Reactive Brilliant Yellow A-4GLN on treated cotton fabric was examined and found to follow a Langmuir-type adsorption curve. It is concluded that the amino-terminated hyperbranched polymer can be used as a salt-free auxiliary in reactive dyeing on cotton.     

高阳离子化度叔胺型聚丙烯酰胺在活性染料无盐染色中的应用(英文)

Tertiary amine cationic polyacrylamide with high cationization degree was used as a new cationic agent to pretreat cotton with dip-pad-bake method. The obtained cationic cotton was dyed with reactive dyes in the absence of electrolyte. The effects of the characteristics of the cationic agent and the pretreatment conditions on dyeability of reactive dye were investigated. The results showed that the fixation and K/S values of the reactive dyes on the cationic cotton were improved compared with those on the un-treated one in the presence of salt. Tests on fastness properties of the dyed cotton and fabric quality of the pretreated cotton were carried out and the results showed that wash and rub fastness of the salt-free dyeing were both satisfactory. And anti-crease property, tensile and tear strength, and handling of the cationic cotton were also good compared with that of the untreated one.     

Deep‐coloured polyester/cotton blends with low concentrations of polymethylol dyes by a one‐pass continuous dyeing process

An obvious limitation of the one‐pass continuous dyeing process for polyester/cotton blends is its inability to achieve deep colour depth, which is caused by the low dye fixation yields of commercial reactive dyes. In this study, the performances of polyester/cotton blends dyed with high‐fixation polymethylol dyes and disperse dyes were compared with those of polyester/cotton blends dyed with a mixture of reactive dyes and disperse dyes. Polymethylol dyes were observed to be suitable for dyeing polyester/cotton blends when used in low concentrations; the required concentrations of polymethylol dyes were only 23–58% of the concentrations of commercial reactive dyes required to reach a given colour level on polyester/cotton blends. The wash and crocking fastness of polyester/cotton blends dyed with polymethylol dyes were similar to those of polyester/cotton blends dyed with reactive dyes.     

Chemical modification of cotton to improve fibre dyeability

A new fibre-reactive quaternary compound containing an acrylamide residue was synthesised and used as a cotton modification reagent. The agent was applied to cotton fabrics using a pad-bake process. It was found that the treated fibre could be dyed with reactive dyes without the addition of salt or alkali. The reactive dyes were almost completely exhausted and showed a high degree of covalent bonding with the pretreated cellulose. The effect of varying the pretreatment conditions was investigated and the optimum conditions for pretreating and dyeing were established.     

Synthesis of temporarily solubilised azo disperse dyes containing a β‐sulphatoethylsulphonyl group and dispersant‐free dyeing of polyethylene terephthalate fabric

Disperse dyes containing a β‐sulphatoethylsulphonyl group have temporary solubility and can be applied for dispersant‐free dyeing of hydrophobic fibre. Six novel temporarily solubilised azo disperse dyes having a β‐sulphatoethylsulphonyl group in their structures were synthesised, and their dyeing properties on polyester were investigated. As a dye intermediate, a diazo component having dibromo groups was prepared, and 4‐diethylamino‐4′‐(2‐sulphatoethylsulphonyl‐4,6‐dibromo)azobenzene dyes were prepared by a diazo‐coupling reaction. Then, the dyes containing dicyano groups were prepared by cyanation of corresponding dyes with dibromo groups. The absorption maxima of the dyes were affected by the substituents in the diazo and coupling component rings and varied from 434 to 616 nm in dimethylformamide. Polyethylene terephthalate woven fabric could be dyed with the synthesised temporarily solubilised dyes without using any dispersants. Dyebath pH affected the K/S value at maximum absorption as well as percentage exhaustion on polyethylene terephthalate fabric, and the optimum pH was 5. The dyes gave brownish orange, red, purple, and greenish blue hues on polyethylene terephthalate fabrics, and colour build‐up was good. Wash fastness was good to excellent, rubbing fastness was moderate to excellent, and light fastness was poor to moderate.     

天成HN型活性染料涤/棉一浴一步法染色

天成HN型活性染料是一系列高温染色中性反应固着型具有季胺型吡啶甲酸基团的三嗪型活性染料,具有较高的染色牢度和良好的染色性能。本文研究了HN型活性染料用于涤/棉的一浴一步法染色工艺。工艺宽容性大,染色重现性好。     

合成纤维及其混纺织物用染料的研究(Ⅲ)含β-羟乙基砜硫酸酯基活性分散染料在涤-棉混纺织物上的染色机理

本文探讨了含β-羟乙基砜硫酸酯基活性分散染料在涤-棉混纺织物上热熔染色各阶段的迁移及其存在形态.测定了染料的升华性能和气相转移.研究热熔条件对染料在涤-棉混纺织物上分配的影响及染料分子结构与分配的关系.由此提出了这类染料在涤-棉混纺织物上的热熔染色机理.     

Dyeing cotton with reactive dyes under neutral conditions

This paper describes a new method to dye cotton with selected reactive dyes by long-liquor – or so-called 'exhaustion'– processes under neutral conditions. Particularly promising results were obtained with reactive dyes containing free vinyl sulphone residues. Although there are dyes on the market that contain free vinyl sulphone groups, for example, the Novacron C (Huntsman) range of dyes, many of this class contain 'blocked' vinyl sulphone residues; examples include sulphatoethylsulphone or chloroethylsulphone precursor groups, and these may be preactivated to the highly reactive vinyl sulphone form simply by a mild alkali treatment. After this activation, neutral, long-liquor dyeings can be carried out at the boil in the presence of electrolyte. This new dyeing method gave very good results in terms of overall fixation efficiency values, without the need for alkali additions.     

Synthesis and application of KM‐type reactive dyes containing 2‐ethoxy‐4‐chloro‐s‐triazine

A new kind of hetero‐bifunctional reactive dye containing 2‐ethoxy‐4‐chloro‐s‐triazine, with better activity matching with β‐hydroxyethyl sulphone sulphate at a low fixation temperature, was successfully synthesised and characterised. An ethoxy group was designed to be introduced into triazine to increase the substantivity and the reactivity of the dyes. Thereby, the fixation of mono‐s‐chlorotriazine/hydroxyethyl sulphone sulphate (KM‐type) bifunctional reactive dyes on cotton was improved, and dyeing under mild conditions with high fixation was realised. Nineteen dyes with orange, red and blue colours were synthesised and characterised by UV‐Vis and infrared spectroscopy and mass spectrometry. Synthesised dyes were dyed at 60, 75 and 90°C, respectively. Exhaustion and reactivity for all of the ethoxy‐containing KM‐type dyes was over 90% at the optimal temperature, and fixation was over 87%, which was higher than the ethoxy‐free comparative dyes. The optimal fixation temperature of ethoxy‐containing dyes was initially reduced to 75°C, and then to 60°C. Compared with comparative dyes, the wash fastness and light fastness were basically unchanged, and the wet rub fastness of the H‐acid series was reduced by one grade.     

One-bath dyeing of wool/acrylic blends with reactive cationic dyes based on monofluorotriazine

A series of reactive cationic dyes containing the monofluorotriazine structure has been synthesised and their dyeing behaviour on wool, acrylic and a 50:50 wool/acrylic blend studied using a one-bath method. The results indicate that reactive cationic dyes having this structure give a high level of exhaustion and fixation on these fibres. Fastness properties on the wool/acrylic blend were also in general very good.     

Innovation and application of dyes with high fixation

Reactive dyes are the main species for cotton dyeing due to their wide range of hue, satisfactory color fastness and facile application method. Aiming at increasing fixation on cotton fibers, benzimidazolone yellow reactive dyes, sulfonamide red reactive dyes and anthraquinone azo blue reactive dyes are designed. The preparation, characterization and application properties of these dyes with high fixation are introduced in detail. In order to achieve dye fixation to near 100%, macromolecular cro...