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.     

New Dyes and their Intermediates for Synthetic-polymer Fibres

Halogenobenzothiazolylazo dyes were prepared by coupling diazotised halogeno-2-aminobenzothiazoles to N-β-hydroxyethyl-N-β-cyanoethyl-m-toluidine. The colour and fastness properties of the dyes on secondary cellulose acetate and on polyester fibre are compared with respect to the position and the nature of the halogen atom. Dyes containing 4-halogeno atoms have the highest fastness to sublimation on polyester fibres; the fastness to light of the dyes is considerably higher on secondary cellulose acetate than on polyester fibres, but differences between individual dyes are small.     

Dispersant-free dyeing of polyester with temporarily solubilised disperse dyes

In an effort to overcome some of the environmental problems associated with the use of dispersing agents, four temporarily solubilised disperse dyes had previously been synthesised and characterised for use in dispersant-free polyester dyeing. In this paper the dyeing and fastness characteristics of these dyes on polyester fabrics have been examined. It was found that the optimum pH to guarantee a moderate rate of hydrolysis was 5, which allowed temporarily solubilised disperse dyes to be successfully applied to polyester without the use of dispersants. The dyebath remained stable during the dyeing procedure. The dyes exhibited good levelling and fastness properties on polyester.     

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.     

Dyeing Properties of Monoazo Disperse Dyes Containing 5- and 6-Aminoindazoles as Diazo Components

In this study the effects of various coupling components, used in conjunction with 5- and 6-aminoindazoles as diazo components, on the spectral characteristics and dyeing properties of dyes for cellulose secondary acetate (acetate), nylon 6 and polyester have been investigated. Eight new disperse dyes suitable for acetate, nylon 6 and polyester were synthesised. In general, when disperse dyes are applied in the dyeing of nylon 6 the colour fastness to water is very low. However, we found that the new dyes synthesised showed good dyeing properties in all cases, on all three fibre types. Some of the dyes obtained using 5- and 6-aminoindazoles gave bright dyeings of good fastness to light, washing, perspiration, dry cleaning and rubbing. Some bright dyeings on polyester were also obtained.     

The synthesis and application of some aziridinyl disperse dyes

The aziridinyl group has been introduced as a terminal substituent into a series of monoazo disperse dyes; the dyes absorb hypsochromically in comparison with their counterparts containing larger terminal ring systems. When applied from aqueous dyebaths the dyes exhibit higher wash fastness on nylon 6.6 and diacetate fibres than conventional dispersedyes of similar structure and relative molecular mass. On polyester and triacetate fibresthe aziridinyl dyes display similar wash fastness to conventional dyes. Dye polymerisation and/or covalent fixation may account for the observed high fastness of the dyes on diacetate and nylon fibres. With the exception of nylon 6.6, the aziridinyl dyes display lower light fastness than conventional disperse dyes on the fibres studied, this being attributable to the greater susceptibility of the aziridinyl dyes to oxidative rather than reductive photodegradation.     

Use of β‐cyclodextrin in the dyeing of polyester with low environmental impact

In this paper, the effect of β‐cyclodextrin as an additive in the dyeing of polyester with disperse dyes, as a substitute for a commercial surfactant commonly used, was explored with the aim of reducing the environmental impact of the exhausted baths. Using a chemometric approach, a small group of dyes was selected as a ‘training set’ to be representative of a larger series of dyes with a similar structure. The selected dyes were synthesised and applied to the dyeing of polyester fibres under various conditions. The technological properties of the dyed samples were measured. The results showed that β‐cyclodextrin can satisfactorarily be used as an additive in dyebaths for polyester without the addition of other auxiliaries, with a positive environmental impact. Solubility isotherms evidenced dye–β‐cyclodextrin interactions. The formation of inclusion complexes did not produce negative effects on the dyeing performance. Light fastness values were modelled as a function of the structure by the chemometric partial least squares method and the established model was used to predict the fastness of dyes of analogous structure, not yet explored.     

含羧甲磺酰基水溶性分散染料的研究

本文提出一类含有羧甲磺酰基（—SO_2CH_2COOH）的新的水溶性分散染料。利用应用时的高温,它转变为不溶性的分散染料。因此,在成品加工时不必进行砂磨,不需要扩散剂。它在弱酸、中性和碱性中都可使用,并适用于纯涤纶和涤/棉织物的印花和轧染。     

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.     

Structure—wet fastness relationships of some blue disperse dyes for polyester

A range of monoazo blue disperse dyes has been synthesised by coupling benzenoid and heterocyclic diazo components to aniline derivatives containing ester functions. The colour properties and wet fastness of the dyes on polyester at 1/1 standard depth have been examined and rationalised in terms of dye structure. Styryl dyes have also been prepared in order to compare their wet fastness properties to those of the azo dyes.     

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.     

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.     

Study of the Influence of Gemini Cationic Surfactants on the Dyeing and Fastness Properties of Polyester Fabrics Using Naphthalimide Dyes

In this paper, the dyeing and fastness properties of three monoazo naphthalimide dyes including different imide groups (dye 1: ethyl amine, dye 2: ethyl glycinate and dye 3: glycine) on a polyester fabric were investigated in the presence of two gemini cationic surfactants (symbolized as 12‐4‐12 or 14‐4‐14) and a conventional single chain surfactant, dodecyltrimethylammonium bromide (DTAB). The color strength (K/S) of naphthalimide dyes on polyester fabric was measured through the reflectance spectrophotometric method, and the values obtained in the presence of different cationic surfactants increased in the order of dye 3 < dye 2 < dye 1. Although the K/S values indicated that the gemini cationic surfactants had almost no effect on the dyeing behavior of dye 1, but they were effective in dyeing ability of dye 2 and dye 3. The data for dye 2 demonstrated that build up of polyester fabrics in the presence of gemini surfactants are more than the conventional cationic surfactant, and also K/S values of dye 3 on polyester fabrics were in the order: DTAB > 12‐4‐12 > 14‐4‐14. It was found that the washing and rubbing fastness properties improved with increasing the concentration of surfactants. In addition, the sublimation fastness of dye 3 was more than the other dyes owing to the presence of a polar group in its chemical structure, and the light fastness of naphthalimide dyes on polyester fabrics was generally moderate.     

载体复配对涤纶分散染料常压沸染的影响研究

将N-正丁基邻苯二甲酰亚胺、自制苯酯助剂和WLS联合应用于涤纶常压沸染染色中,结果表明:N-正丁基邻苯二甲酰亚胺和苯酯助剂具有增塑涤纶的作用,而苯酯助剂和WLS具有阳离子结构,可促进分散染料阴离子胶束吸附涤纶,这3种助剂按适当比例复配有协效作用。复配载体应用于涤纶织物分散染料常压染色,染料上染百分率、染色织物表观深度、耐摩擦牢度及耐皂洗牢度与传统高温高压染色工艺效果相当。     

Polymerizable Dyes Part II

Abstract

Arylene bisazo resorcinol dyes IIIa-e were prepared and polycondensed with formaldehyde in the presence of aqueous oxalic acid. The resulting polymeric dyes IVa-e were characterized by yield, melting point, colour, elemental analysis and visible and IR spectroscopy. The thermal properties of polymeric dyes were examined by thermogravimetric analysis. Their dyeing performance on nylon and polyester was assessed. The dyeing on nylon and polyester had yellow, orange, red and brown shades with moderate to good, light and wash fastness. Polymerization of bisazo dyes IIIa-e with formaldehyde on dyed nylon and polyester have also been carried out. The dyeing properties of polymeric dyes were compared with the dyes polymerized on nylon and polyester.     

Dispersant-free dyeing of polyester with temporarily solubilised azo disperse dyes from 1-substituted-2-hydroxypyrid-6-one derivatives

Four temporarily solubilised azo disperse dyes based on 1-substituted-2-hydroxypyrid-6-one were synthesised and characterised. The dyes showed high extinction coefficients and had a yellow shade on polyester fabric. They were successfully applied to polyester without the use of dispersants and the optimum pH was found to be 5. It was found that the dyes could be alkali-cleared due to ionisation of the dye under mild alkaline conditions. The dyes exhibited good to excellent fastness properties on the polyester fabric.     

Synthesis and fastness properties of styryl and azo disperse dyes derived from 6-nitro substituted 3-aryl-2-methyl-4(3H)-quinazolinone

The synthesis of 6-nitro substituted 3-aryl-2-methyl-4(3 H )-quinazolinones from readily available starting materials, such as isatoic anhydride, is described. One of these, 3-phenyl-2-methyl-4(3 H )-quinazolinone, has been utilised to prepare a range of styryl disperse dyes for polyester. Novel azo disperse dyes based on 6-nitro-3-( m -diethylaminophenyl)-2-methyl-4(3 H )-quinazolinone as coupling component are reported. The application properties of the dyes on polyester and their fastness properties have been evaluated, with the latter being disappointing.     

Dyeing Properties of Monoazo Dyes Derived from 5-Nitro-2-aminobenzothiazole-3N-oxide on Various Synthetic-polymer Fibres

The preparation of new monoazo dyes from substituted 5-nitw-2-aminobenzothiazole-3N-oxides and aniline coupling components and their dyeing properties on polyester, cellulose acetate, nylon 6 and acrylic fibres are reported. The dyes exhaust well on synthetic-polymer fibres to give bright dyeings of good fastness to dry cleaning and sublimation. Their light fastness is better than that of dyeings of the unnitrated dyes. However the transferability of the nitro dyes is such that they are unsuitable for sublimation printing. The transferability of other dyes derived from 2-aminobenzothiazole-3N-oxide and its derivatives is also assessed.     

The Development of Dyes and Methods for Dyeing Polyester

Early work on the dyeing of polyester fibre showed that only dyes of very low aqueous solubility had substantivity for the fibre, and that for dyeing at the boil without a carrier only the smallest molecular weight disperse dyes, and selected azoic combinations, had sufficiently high dyeing rate to give adequate colour yield in a practicable time of dyeing. The development of carriers for dyeing at the boil, and of machinery for batchwise dyeing under pressure at temperatues up to 140°C, extended the range of suitable dyes to those of lower dyeing rate but higher heat–fastness properties. As an alternative to exhaust dyeing, polyester may be dyed with disperse dyes by padding followed by dry heat fixation at temperatures up to 220°C, and this method has found its main commercial application in the continuous dyeing of polyester–cellulosic blend fabrics. The development of new disperse dyes has followed these trends in application methods, and the proportion of available dyes having higher heat–fastness properties has steadily increased from about 1950 onwards. Improvements have also taken place over the same period in the physical properties of the dyes, to meet the increasingly severe demands on dispersion properties imposed by the newer dyeing methods.     

One-bath dyeing of a polyester/cotton blend with reactive disperse dyes from 2-hydroxypyrid-6-one derivatives

A series of temporarily solubilised reactive disperse dyes based on 1-substituted derivatives of 2-hydroxypyrid-6-one were applied to a 65;35 polyester/cotton blend using a one-bath dyeing method without dispersing agent. The dyeing behaviour of these dyes on polyester and cotton fabrics, and polyester/cotton blend fabric, were studied. The colour yields of the dyes on the polyester/cotton blend were found to be highly dependent on the initial pH, optimum results being obtained at pH 5. Good levelling and good to excellent fastness properties were obtained on the blend, with the exception of lightfastness, which was moderate.