Fading of reactive dyes on cellulose under light and perspiration

The fading of nine reactive dyes on cotton fabrics under light and perspiration was investigated using the ATTS standard and many factors affecting the stability of these dyes were discussed, viz. exposure environment, chromophores of dyes, the pH value and components of the artificial perspiration. The experimental results show that reactive dyes exhibit lowest stability under simultaneous exposure to light, perspiration and oxygen in a wet state. Among all selected dyes, Cu-complex azo reactive dyes appear to be the most sensitive, whereas anthraquinone reactive dyes show the best stability. The pH value of perspiration may also greatly influence the fading of dyes by affecting the hydrolytic stability of dye–fibre bonding. Furthermore, the study on the contribution of artificial perspiration components discloses that some acidic components play major roles in the fading of the dyes and inorganic salts usually decelerate the fading extent.     

活性染料对莲纤维的染色性能研究

为了了解活性染料对莲纤维的染色性能,采用单因素分析法,在改变温度、浴比、时间、元明粉浓度、纯碱浓度等工艺条件下,分别采用两种不同类型的活性染料对莲纤维进行染色,并测试其上染率、固色率、耐皂洗色牢度和耐汗渍色牢度。结果表明:活性大红X-3B上染莲纤维的最佳染色工艺为染色温度40℃,染液浴比1∶40,染色时间60 min,元明粉质量浓度20 g/L,纯碱质量浓度30 g/L;活性嫩黄X-7G上染莲纤维的最佳染色工艺为染色温度40℃,染液浴比1∶50,染色时间60 min,元明粉质量浓度10 g/L,纯碱质量浓度20 g/L;活性染料耐皂洗色牢度和耐汗渍色牢度都在3级以上。     

Synthesis of pharmacological dyes and their application on synthetic fabrics

Seven new azo dyes were prepared by linking various amino derivatives to barbituric acid through diazo coupling reactions. The structures of the azo dyes were identified by elemental analyses and by Fourier transform infrared, proton nuclear magnetic resonance, and mass spectral data. The barbituric acid dyes exist in five different tautomeric forms, with the Fourier transform infrared and proton nuclear magnetic resonance spectra confirming the existence of these dyes in triketo tautomeric form in the solid state and in the diketo form in the liquid state. All the compounds were tested for their antibacterial, antifungal, anticancer, and antioxidant activity. The prepared dyestuffs were dyed on polyester fabrics, and subsequently their dyeing properties and their light, washing, perspiration, rubbing, and sublimation fastness were determined.     

Some Aspects of the Light Fastness of Reactive Azo-dyes on Cellulose under Wet Conditions

The photochemical behaviour of four reactive-azo dyes, (two dyes with poor wet light fastness and two dyes with normal wet light fastness) was examined to elucidate the mechanisms by which some reactive azo dyes, applied to cellulose, fade more rapidly when wet. In one case it was found that the major primary photochemical reaction is photoejection of electrons, which is enhanced in the aqueous environment, while in the second case, a back reaction between hydroxyl radicals and dye molecules is facilitated by the aqueous environment.     

环境因素对染料日晒牢度的影响

本文综述了光、染料聚集态、染色深度、汗液及纤维种类等环境因素对染料日晒牢度的影响.并对各个因素所起作用的机理和方式作了详尽的阐述.指出染料的日晒牢度是受其化学结构和所处的外部环境及形态共同作用的,要根据不同的服用环境和需要来设计染料结构,以提高染料的日晒牢度.     

纳米级分散蓝2BLN的制备及应用

普通分散蓝2BLN染料滤饼和分散剂经机械球磨得到染料分散液,滴加到快速搅拌的分散剂水溶液中进行再沉淀,得到的染料粗品在100 MPa下进行高压均质得到纳米级分散蓝2BLN液体染料,并完成了1 t/批的中试工业化实验研究。经激光粒度仪、Zeta电位粒度仪和透射电镜扫描检测,染料粒径D90≤90 nm。经室温放置稳定性实验,在室温下放置180 d后液体染料粒径无明显变化。对制备的纳米级染料进行了印染性能检测,其耐光、耐洗、耐汗渍、耐干热、耐摩擦等指标都比普通染料优越。     

The effect of perspiration on photo-induced chemical reaction of azo dyes and the determination of aromatic amine products

In order to investigate the impact of perspiration on photo-induced chemical reaction of azo dyes and the carcinogenic aromatic amine products produced from the reaction, we have carried out experimental studies on the photochemical reaction of C.I. Reactive Red 2 mixed with American Association of Textile Chemists and Colorists（AATCC）standard artificial perspiration. UV-vis spectroscopic technique was employed to monitor the reaction processes, and the reaction products were analyzed by hollow fiber protected liquid-liquid-liquid phase micro-extraction with capillary electrophoresis（HF-LLLME-CE). The results showed that perspiration had remarkable influence on the photochemical reaction of azo dyes. Aromtic amines formed during the photochemical process as a result of reduction of azo dyes by organic components in perspiration. The HF-LLLME-CE methodology was validated in analyzing aromatic amines produced from the photochemical degradation of azo dye C.I. Reactive Red 2 and C.I. Acid Red 35 mixed with artificial perspiration.     

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...     

Use of siloxanes to increase dye fastness on leather†

Amino‐functionalised siloxanes have been used to increase the number of active sites in leather (and especially suede) available for dye fixation. The use of a second hydrophobic siloxane in conjunction with the amino‐functionalised siloxane, further increases the fastness results. The best results are found for the use of reactive dyes on siloxane pre‐treated leather samples, where washfastness and perspiration fastness results of 4–5 or 5 for all fibres on a multifibre staining material for a commercially acceptable black are obtained. Wet and dry crock fastness of 3 is reached.     

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.     

Dyeing and fastness properties of polyamide fabrics using some acid‐based monoazo disperse dyes

A series of monoazo disperse dyes derived from naphthalimide containing butyric acid has been applied on polyamide fabrics. The build up and dyeing properties of these dyes such as leveling property, wash, light, perspiration for alkaline and acidic conditions, and rubbing fastnesses on polyamide fabrics have been investigated. The results showed that the applied dyes are capable of producing red to bluish red hues on polyamide fabrics. Because of the presence of both carboxylic acid and hydroxyl groups on the molecular structure of Dye 3, it showed desired and more strength in respect to other used dyes. Comparing the build up of these dyes to commercial dyes such as disperse red 60 and disperse red 73 revealed that most of the used dyes have higher build up in comparison to the commercial ones. Measurement of fastness properties of dyed samples indicated that they have good wash (4–5), rubbing (4), perspiration (4–5), and heat fastnesses (4–5) and they possess less than moderate light fastness (3–4) on polyamide fabrics. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

Dyeing of polyester and its blends with some disazo dyes derived from the disodium salt of chromotropic acid and their chelates with transition metal ions

Disazo dyes derived from the disodium salt of chromotropic acid and their chelates with metal ions were applied on polyester, polyester/cotton and polyester/wool blend fibres as disperse dyes. The fastness to washing, perspiration, rubbing and light of the resultant dyeings were measured. The bonding of dye or its complexes to the fibre and the effect of substituent groups on the colour fastness of the dyes are discussed.     

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 and fastness properties of phthalimide‐based alkali‐clearable azo disperse dyes on poly(ethylene terephthalate)

The properties of a series of phthalimide‐containing azo disperse dyes and azo dyes with N‐methyl phthalimide moieties in their diazo component were investigated and compared when used to colour polyethylene terephthalate. The N‐substitution of the phthalimide gave a hypsochromic effect on the colour change and better colour yields on poly(ethylene terephthalate) fabrics, probably because of the electron‐donating property of the methyl group and the higher hydrophobicity of phthalimide‐containing azo dyes compared with those containing phthalimide moieties. The results show that phthalimide‐based azo disperse dyes have excellent dyeing fastness properties and that high wash fastness can be achieved using alkali clearance. This alternative clearance method is important for reducing the environmental impact of the dyeing process by replacing reductive clearing and, in particular, by removing the need for sodium hydrosulphite, which creates a high biological oxygen demand when released in conventional disperse dyeing effluent and which generates aromatic amines.     

Thiophene Based Monomeric and Polymeric Disperse Dyes for Hydrophobic Fibres

Abstract

Eight monomeric dyes have been prepared by coupling 2-amino-3-carbethoxy-4,5-dimethylthiophene with various N-phenylmaleimides. Polymeric dyes have been prepared by free radical polymerization of monomeric dyes and they are characterized by IR spectra, Intrinsic viscosity, molecular weight by Vapour Pressure Osmometry, thermogravimetry analysis and elemental analysis. The monomeric dyes have been also characterized by IR spectral studies and elemental analysis. All the dyes were applied as a disperse dyes on nylon and polyester fibres. The dyed fibres showed fair to good fastness to light on nylon and fair fastness on polyester. The washing, rubbing, perspiration and sublimation fastness properties of the dyed fibres has been found to be very good to excellent.     

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.     

Effect of acylation on the dyeing and fastness properties of some azo dyes

The changes brought about by acetylation, benzoylation and terephthaloylation of some disperse dyes derived from 4–aminoazobenzene on the dyeing and fastness properties are described. Dyes substituted by benzoyl and terephthaloyl groups tended to have better light, wash and sublimation fastness on polyester. The dyes showed good build–up when these groups are coupled with an N–β–cyanoethyl group. Acylation of azo dyes resulted in poor substantivity and poor fastness properties on nylon 6.     

Colour fastness properties of alkali-clearable azo disperse dyes containing a fluoro-sulphonyl group

The colour fastness properties of alkali-clearable azo disperse dyes containing a fluorosulphonyl group have been investigated. In particular, the colour fastness properties of alkali-cleared poly(ethyleneterephthalate) were compared with those of conventional reduction-cleared poly(ethyleneterephthalate). Specifically, 4-aminoazobenzene dyes containing a nitro group in place of the fluorosulphonyl group in the 4'-position were synthesised in order to compare their fastness properties on poly(ethyleneterephthalate) with those of the 4'-fluorosulphonyl analogues.