Triazinylamino-alkylphosphonate reactive dyes for cellulosic fibres

A bifunctional reactive bis-phosphonoalkylaminotriazine dye was synthesised by condensing 2 mol of aminoethylphosphonic acid with the commercially available bis-monochloro- s -triazinyl dye, CI Reactive Red 120. A similar but much lower molecular weight dye was prepared by condensing the commercially available dichloro- s -triazine dye, Procion Red MX 8B, with aminomethylphosphonate. A model aryl-phosphonate dye was also prepared by diazotising m -aminobenzene-phosphonic acid and coupling the diazonium salt to R-salt. These dyes were isolated as their free acids and then converted to their ammonium salts. Pad liquors containing dye, cyanamide and ammonium dihydrogen phosphate were applied to cotton fabric. In the case of the bis-phosphonoethylamino- s -triazine dye, very high dye–fibre fixation values (>90%) were achieved using a pad–batch–bake procedure; for the Procion T model dye, the comparative maximum fixation was only modest. In the absence of cyanamide, no fixation could be obtained for the arylphosphonate dye but both bis-phosphonoalkylaminotriazine dyes gave significant fixation.     

An analysis of the substantivity of hydrolysed reactive dyes and its implication for rinsing processes

Substantivity plays a key role in dyeing processes, for dye exhaustion and fixation as well as for dye removal during rinsing. The latter is especially relevant for reactive dyes when the hydrolysed dye has to be removed from the fibre. The substantivity of the hydrolysed form of 46 commercially important reactive dyes was analysed at two temperatures for a wide range of dye amounts, pH values and electrolyte concentrations. The results showed that substantivity was highly dye‐specific and varied, for each variable analysed, almost within the entire theoretically possible range of values. Substantivity values correlated best with the number of sulphatoethylsulphone groups in the dye molecule and dye solubility in the presence of sodium chloride. Sensitivity to electrolyte, pH, dye amount and temperature broadly correlated with each other, implying that a reduction in electrolyte concentration and an increase in pH and temperature are more beneficial in the removal of highly substantive reactive dyes. Some dyes remained highly substantive even at 90 °C, indicating that dye removal in industrial processes, too, would be difficult. For dyes with little substantivity, however, wash baths at the boil do not appear to be necessary, neither is the significant removal of electrolyte before rinsing at elevated temperature.     

Photofading of reactive dyes on silk and cotton: effect of dye—fibre interactions

Fading characteristics of selected bifunctional and monofunctional reactive dyes have been studied on silk and cotton. Dyes were applied in the reactive and hydrolysed forms in order to study the influence of covalent bonding on the photofading of reactive dyes. The active dye-fibre interaction was found to influence the light fastness of dyes. Reactive dyes forming covalent bonds exhibited better fastness especially on cotton. Only a slight difference in light fastness of fixed and unfixed dyes was observed in the case of silk. The bifunctional reactive dyes, due to the formation of crosslinks, maintain the integrity of the fibre particularly for short periods of light exposure.     

Dyeing properties of soya fibre with reactive and acid dyes

In order to determine the most suitable type of dye for soya bean fibre, the dyeing properties of three acid dyes and three bifunctional reactive dyes were compared. Additionally, the effect of a range of reactive groups on dyeing performance were studied, including difluorochloropyrimidine, monofluorotriazine, monochlorotriazine and β-sulphatoethyl sulphone, and of these the first was found to perform best. Irrespective of reactive group, however, the main factor affecting build-up was found to be the substantivity of the dye for soya fibre. The monofunctional reactive dyes in general were found to exhibit good wash fastness.     

Reactive dye dyeability of cellulose fibers with cellulase treatment

Reactive dye dyeing was performed on cellulose fibers in combination with cellulase treatment. First, polynosic and cupra fibers were selected to discuss the saturation dye uptake of the previously cellulase-treated fibers. Cupra fiber exhibited a similar saturation dyeuptake dependence on weight loss, irrespective of dye species and the substantivity of the dyes. In the polynosic fiber, the saturation dye-uptake dependence on weight loss exhibited a minimum using a lower substantive dye and a maximum using a higher substantive dye. Comparative discussions of the saturation dye uptake based on X-ray and infrared measurements led to the assumption that a region dyeable with the higher substantive dye is created by the cellulase treatment of the polynosic fiber. This region is assumed to have some degree of order as shown by infrared spectroscopy. Next, cotton fiber, which is important from a practical viewpoint, is dyed and then hydrolyzed. It was found that the hydrolysis of cotton fiber dyed with a reactive monofunctional dye was retarded almost in the same manner as that dyed with Congo Red. The hydrolysis of cotton fiber dyed with dyes of higher substantivity and more bifunctional property was probably retarded to a greater extent compared to dyes of lower substantivity and less bifunctional property. © 1996 John Wiley & Sons, Inc.     

Modification of a vinylsulphone reactive dye using diethanolamine-O-disulphate

The β-sulphatoethylsulphone dye, Remazol Orange 3R, was converted to its vinylsulphone form and then reacted with diethanolamine- O -disulphate (DES) to produce a new type of reactive dye carrying pendent amino-di(ethyl- O -sulphate) groups. Application of the latter dye to cotton, using the pad–dry–steam process in the presence of alkali, resulted in a good level of dye–fibre covalent fixation. It had been expected that the sulphate ester would react by nucleophilic substitution to give bifunctional covalent attachment of the dye to cotton. It was shown, however, that an intermediate dye containing an aziridine residue was produced, which under hot alkaline conditions was converted by β-elimination to the vinylsulphone dye, and it was in this form that reaction with cotton took place.     

活性染料S、E、F、R值测试与配伍性能研究

本文采用活性染料特征值S，E，F，R（S-直接性值，E-吸尽值，F-固色值，R-固色速率）来评价染料的配伍性，选择双活性基型活性染料，按一定工艺处方，浸染纯棉织物，测定各染料S，E，F，R值，通过测试出的S，E，F，R值选择一些染料进行组合，拼色和研究，通过实验证明，用S，E，F，R值相近的染料拼色，染色时均匀上色。色相变化很小，而用S，E，F，R值相差大的染料拼色。染色过程中色差变化很大。染色难以控制。     

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.     

Synthesis of reactive dyes based on the bis-(N-carboxymethylamino)monoquaternary-triazine-bis-ethylsulphone reactive group. Part 1: Application to cotton cellulose

Reactive dyes containing the bis-( N -carboxymethylamino)monoquaternary-triazine-bis-ethylsulphone [bis-( N -CMA)-MQT-bis-ES] group and related derivatives have been synthesised. When boiled under mildly acidic conditions, such dyes are able to form two small vinylsulphone dye molecules through a process of 1,2-trans elimination. The bis-( N -CMA)-MQT-bis-ES dye was applied using different dyeing procedures (novel dyeing methods 1 and 2). The dyeing and soaping-off results of bis-( N -CMA)-MQT-bis-ES dye were compared with a model sulphatoethylsulphone dye applied using the conventional alkaline fixation method used for applying this type of reactive dye to cotton. The bis-( N -CMA)-MQT-bis-ES dye showed higher exhaustion and fixation values applied using novel dyeing method 2 compared with the sulphatoethylsulphone dye applied using the alkaline fixation method. The soaping-off efficiency for the large bis-( N -CMA)-MQT-bis-ES dye applied using novel dyeing method 2 was the same as that obtained for the sulphatoethylsulphone dye applied using the alkaline fixation method.     

One-bath dyeing of polyester/cotton with disperse and bis-3-carboxypyridinium-s-triazine reactive dyes. Part 1: Factors limiting production of heavy shades

Over the last 20 years, selected disperse dyes and bis-3-carboxypyridinium- s -triazine reactive dyes have been widely promoted for the exhaust dyeing of polyester/cotton blends in a one-bath-one-stage ('all-in') process under neutral conditions. However, despite the time and energy savings afforded by this elegant dyeing process, there is a belief in the dyeing industry that economical production is limited to pale and medium depths of shade. In this paper, the two dye classes (disperse dyes on polyester and bis-3-carboxypyridinium- s -triazine reactive dyes on cotton) have been investigated to understand why heavy depths of shade cannot readily be obtained economically using this process.     

Use of a novel water-soluble arylating agent to dye wool and wool blends with disperse dyes

A series of water-soluble fibre-reactive arylating agents were synthesised and evaluated from the stand-point of improving fibre coloration with disperse dyes. In particular, the compound, sodio-2,4-dianilino-6-[4'- β -sulphatoethylsulphonylanilino]- s -triazine (FAA 200) was found to be promising; this compound could be applied in the same bath as a disperse dye at pH 5–6. Under the latter conditions this compound showed high substantivity to wool and at the boil readily underwent β -elimination of the sulphate ester residue to give the vinyl sulphone reactive group which adds on to nucleophilic sites in the fibre to form a covalent bond. Coapplication with commercially available disperse dyes gave bright, level dyeings that exhibited promising wet fastness. FAA 200 was used as an auxiliary to dye disperse dyes on both fibre components of a wool–polyester blend fabric; it was found that addition of hydrogen peroxide or sodium thiocyanate was necessary to obviate reduction of certain disperse dyes when dyeing at 120 °C.     

The Physical and Chemical Properties of Reactive Dyes and their Effect on Printing Behaviour

The currently available methods of fixation of prints on textiles are reviewed and the influence of the reactivity, diffusion coefficient and substantivity of reactive dyes on their behaviour in printing is described. It is shown how the suitability to the various fixation methods and the stability in alkaline printing paste of reactive dyes can be correlated with the values of reactivity, diffusion coefficient, and substantivity measured by simple techniques. Changes that can be made to the reactivity of a dye by modification of its structure or its application conditions are also illustrated. The influence of hydrolysis of reactive dyes and of breakage of the dye–fibre bond during processing on the fixation achieved is discussed and a method is developed enabling the actual rate of reaction of reactive dyes with cellulose to be calculated.     

Synthesis and application of a hetero-bifunctional disulphidebis(ethylsulphone/monochlorotriazine) reactive dye

The behaviour of a heterobifunctional reactive dye based on a disulphidebis(ethylsulphone/monochlorotriazine) reactive system has been investigated. Relatively high degrees of exhaustion and fixation were achieved for cotton fabrics dyed with the disulphidebis(ethylsulphone/monochlorotriazine) reactive dye compared to bifunctional sulphatoethylsulphone/monochlorotriazine and/or conventional monofunctional monochlorotriazine reactive dyes. The results also indicate that the fastness properties are approximately the same for all the dyes studied in this investigation.     

Structure—reactivity studies of a new polyfunctional disulphide bis(ES-MCT/SES) reactive dye applied to silk

A new polyfunctional reactive dye containing disulphidebis(ethylsulphone-monochlorotriazine/sulphatoethylsulphone) reactive system has been synthesised and applied to silk. High exhaustion/fixation results have been achieved at 90 °C and pH 9. The vinylsulphone precursor of the disulphidebis(ethylsulphone) group combined with a sulphatoethylsulphone/monochlorotriazine reactive system confers a relatively high fixation efficiency for this type of polyfunctional reactive dye when compared with that of a conventional bifunctional reactive dye containing the sulphatoethylsulphone/monochlorotriazine reactive system. The results also indicate that high fastness properties were obtained for the reactive dyes under investigation.     

Design and application of a multifunctional reactive dye capable of high fixation efficiency on cellulose

A polyfunctional reactive dye containing two dichloro- s -triazine residues linked through aliphatic amino groups via a third triazine system to the chromophoric residue has been prepared. The dye was synthesised stepwise from a specially synthesised 2,4-dichloro- s -triazine dyes. The first step is the reaction of both carbon–chlorine sites in the 'parent' dye with 2 mol ethylenediamine under selected conditions of pH and temperature; these conditions ensure that only one of the amino groups in the ethylenediamine will react to give the bis-2,4-aminoethyleneaminotriazine dye. The second step is the condensation of 2 mol cyanuric chloride with the two pendant primary amino groups. The alkylamino-linked dichloro- s -triazine dyes show very different dyeing properties when compared with those shown by the parent dichloro- s -triazine dye, which has the reactive group linked directly into the aromatic chromophore; in particular, the new dyes have high fixation efficiencies when dyed on cotton at 50 °C and the dye–fibre bond stability to boiling acidic conditions is very good.     

Pretreatment of cotton with poly(vinylamine chloride) for salt-free dyeing with reactive dyes

Poly(vinylamine chloride) has been investigated as a pretreatment for the salt-free dyeing of cotton with reactive dyes. Dye fixation was found to be much higher than by conventional dyeing without pretreatment, even in the presence of a large amount of salt. The influence of pretreatment conditions on dye fixation, such as pad–bake variables and the concentration of poly(vinylamine chloride), has been studied. The dyeing behaviour of CI Reactive Red 2 on pretreated cotton was examined and found to follow a Langmuir-type adsorption curve. Dyed cotton pretreated with poly(vinylamine chloride) showed excellent wash fastness and good rub fastness. It is concluded that poly(vinylamine chloride) is effective as a pretreatment for salt-free dyeing with reactive dyes.     

Synthesis and application of a polyfunctional bis(monochlorotriazine/sulphatoethylsulphone) reactive dye

The behavior of a polyfunctional reactive dye containing bis(monochlorotriazine/sulphatoethylsulphone) reactive system on silk has been investigated. The twinned monochlorotriazine/sulphatoethylsulphone reactive system confers a relatively high fixation efficiency of this type of polyfunctional reactive dye even at low salt and/or temperature conditions when compared with that of the conventional bifunctional reactive dye containing one monochlorotriazine/sulphatoethylsulphone reactive system. The results also indicate that the fastness properties are approximately the same for both the reactive dyes under investigation.     

Effect of various bioscouring systems on the accessibility of dyes into cotton

The effect of four different enzymatic bioscouring systems for cotton have been compared in regard to the dyeability of reactive, cationic and acid dyes. The residual pectin content was determined and the results assessed in terms of dyeability against control samples prepared in the absence of enzyme. The capacity of a bifunctional reactive dye to cover the differences between fabrics treated with different bioscouring treatments was very good. Exhaustion of the cationic dye relative to alkaline scouring was increased by 27.5% and that of the acid dye decreased by 48.2%, indicating that pectin hydrolysis produced an increase in the negative charge on the fibre. The dye exhaustion differences between the four enzymatic systems studied were of significance and confirmed the hypothesis that each enzymatic system provides its own end-groups, resulting in differences in the response of the fibre to dyeing. Enzymatic bioscouring reduces the pollution level of the effluent.     

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.     

Study of the desorption of hydrolysed reactive dyes from cotton fabrics in an ethanol–water solvent system

The factors influencing the desorption of hydrolysed dyes resulting from reactive cotton dyeings in an ethanol–water solvent system, including the volume ratio of ethanol to water, pH, and temperature, were investigated. The maximum desorption was achieved when the volume ratio of ethanol to water was optimised to 4:6. Desorption increased with an increase in pH and temperature. The kinetic curves of dye desorption at three different temperatures fit a two‐step kinetic model. The dye desorbability at 60 °C in an ethanol–water system was similar to that observed using conventional water washing in the presence of detergent at 95 °C. Findings suggest that wash‐off in an ethanol–water system can be considered as an alternative, more effective process for removing hydrolysed dyes from reactive cotton dyeings.