Reactive dyeing of silk using commercial acid dyes based on a three‐component Mannich‐type reaction

Acid dyes are employed for commercially dyeing silk, which results in ionic bonds between the silk fibroin and the dye. This generally leads to low wet fastness properties for dyed silk fabrics. In this work, three commercial acid dyes with aromatic primary amine structures were selected to dye silk using a Mannich‐type reaction, resulting in improved wet fastness of dyed silk by forming covalent bonds between silk fibroin and dye. The Mannich‐type reactive dyeing was applied to silk fabrics at both 30 and 90°C in trials. Dyeing at 90°C can shorten the dyeing time compared with dyeing at 30°C, even although dye exhaustion and relative fixation at 90°C were a little lower. The dyeing process was optimised when the dyeing temperature was 90°C, dyebath pH 4, dye‐to‐formaldehyde ratio 1:30 and holding dyeing time 60 minutes. The results showed that the dye exhaustion on silk fabrics for the three aromatic primary amine‐containing acid dyes exceeded 94% and their relative fixation was over 80%. Their washing and rubbing fastness reached grade 4 or higher. Hence, the colour fastness properties of dyed silk fabrics using the Mannich‐type reactive dyeing method is superior to the conventional acid dyeing method using the same aromatic primary amine‐containing acid dyes. The Mannich‐type reactive dyeing for silk fabrics at 90°C can be developed into a novel and rapid reactive dyeing method, promising an effective dyeing process with excellent colour fastness.     

Synthesis and application to cellulose of reactive dye precursor of anti‐bacterial N‐halamine

To achieve textile dyeing and functional finishing in one process, a bleach‐resistant reactive dye precursor to anti‐bacterial N‐halamine was synthesised by reacting a type of dichlorotriazine reactive dye with 4‐amino‐2,2,6,6‐tetramethylpiperidine. The synthesised compound, which can be transformed to an N‐halamine molecule by exposure to dilute bleach solution, was used to dye cotton fabrics. After exposure to a dilute sodium hypochlorite solution, dyed cotton fabrics showed excellent anti‐bacterial properties against Staphylococcus aureus and Escherichia coli O157:H7, facilitating a ca. 6‐log reduction in bacteria within a short period of contact. Compared with the dichlorotriazine reactive dye, the reactive dye precursor demonstrated comparable dyeing properties including exhaustion and fixation values. No differences in rub fastness, wash fastness or bleach fastness were detected between fabrics dyed with, respectively, dichlorotriazine reactive dye and the reactive dye precursor to N‐halamine.     

Dyeing and finishing of lyocell union fabrics: an industrial study

Lyocell union fabrics, namely lyocell/silk and lyocell/polyester fabrics, were woven in different fabric constructions and dyed with reactive dyes, acid dyes and a disperse dye. The resulting dyed fabrics were given a resin finishing treatment and their wash fastness was measured. With appropriate dye selection and control of dyeing conditions, some bright solid shades and effective cross‐dyed shades were obtained. The dyed and finished fabrics had a smooth, lustrous handle, ideal for lightweight garments.     

One‐step dyeing of polyethylene terephthalate fabric,combining pretreatment and dyeing using alkali‐stable disperse dyes

In the conventional dyeing process, polyester and its blended fabrics are usually dyed in a weak acidic medium. In order to reduce cost and improve production efficiency, a new dyeing method – one‐step dyeing of polyethylene terephthalate fabrics, combining pretreatment and dyeing in alkali conditions – was investigated. The alkali‐stable disperse dyes Red 900, Red 902, Yellow BROB and Blue 825 were used to dye polyethylene terephthalate fabrics. The dyeing properties of polyethylene terephthalate fabrics in the case of one‐step dyeing at various pH values or sodium hydroxide concentrations were discussed in terms of colour yield, colour parameters and fastness. The performance of one‐step dyeing using alkali‐stable disperse dyes was excellent. The dyed fabric had good fastness. Wet processing could be combined and shortened. One‐step dyeing of polyethylene terephthalate fabrics could reduce the consumption of water and energy and improve production efficiency. One‐step dyeing of polyethylene terephthalate has potential application in cleaner textile production.     

Electrostatic self‐assembly dyeing of cotton fabrics

A new approach to the dyeing of cotton fabrics using an electrostatic self‐assembly method was evaluated. Cotton fabrics were pretreated with 2,3‐epoxypropyltrimethylammonuium chloride and cationic charges were produced on the fabric surfaces. For the dyeing of cotton fabric, reactive and acid dyes were used. Oppositely charged anionic reactive/acid dyes and cationic poly(diallyldimethylammonium chloride) were alternately deposited on the surface of cationised cotton fabrics. Ten multilayer films of dye/poly(diallyldimethylammonium chloride) were deposited on the cotton fabric surfaces using a padder. The build‐up of the multilayer films and the level of colour strength (K/S) achieved are discussed. Samples of cotton fabrics were also dyed with the same dyes, but using the exhaust method, and both types of dyed samples were compared. The washing, rubbing and light fastness properties were evaluated for the dyed fabrics.     

Neutral dyeing of wool and wool/polyester blend fabrics using sulphatoethylsulphone reactive‐disperse dyes

Two models of temporarily anionic sulphatoethylsulphone reactive disperse dyes were applied to wool, polyester and wool/polyester blend fabrics at different dyeing pH. Maximum exhaustion values and colour yield were observed at pH 7. The results showed that reactive disperse dyes containing bis‐sulphatoethylsulphone reactive groups were more convenient for neutral dyeing of wool and wool/polyester blend fabrics if compared with a dye containing a mono‐sulphatoethylsulphone group. Excellent to very good wet fastness properties on all dyed fabrics were achieved.     

Improving the colour fastness of dyed nylon‐6 fabric by graft copolymerisation and curing of acrylic acid

The influence of grafting and grafting–curing of acrylic acid on the colour fastness of nylon‐6 fabric dyed with an acid dye of low wash fastness was investigated. The variables involved in grafting were initially optimised for pristine nylon‐6 fabric prior to grafting the same monomer onto the dyed fabrics. The highest graft yield achieved for the pristine and dyed nylon‐6 fabrics was 44 and 14% respectively. Grey scale testing and colorimetric analysis revealed that the highest colour fastness and the smallest drop in colour strength belonged to the dyed–grafted–cured nylon‐6 fabric. The colour components were measured, and the total colour difference of each sample after five washing cycles was computed. The specific colour difference showed that the implementation of either grafting or grafting–curing processes will alter the reference colour of the dyed fabric. The tensile strength of the grafted and grafted–cured fabrics was respectively 2.7 and 6.3% lower than that of dyed nylon‐6.     

纯棉织物涂料染色工艺的研究

本文研究了阳离子改性纯棉针织物荧光涂料染色的新工艺,系统分析了涂料浓度、染色温度、粘合剂用量、焙烘温度等工艺参数对涂料染色织物各项性能的影响。通过测定染色织物的K/S值、摩擦牢度、皂洗牢度,得到柠檬黄荧光涂料对阳离子改性纯棉针织物染色的最佳工艺配方:涂料浓度为0.5%~3%(o.w.f.),染色温度为60℃,粘合剂用量为5 g/L,焙烘温度为120℃。     

Synthesis and application of a novel,triphendioxazine‐based,phosphorus‐containing acid dye for wool

A novel phosphorus‐containing acid dye based on triphendioxazine was designed and synthesised from diphenylamine through a series of reactions. The dye has a navy‐blue colour, high molar extinction coefficient of 5.32 × 10⁴ l/mol·cm, and high substantivity for dyeing wool in a salt‐free, aqueous dyebath. A high exhaustion value of 98.2% on wool fabrics was recorded at 3% omf and a liquor ratio of 1:20. The wash fastness values of the acid dye, including colour change and staining on cotton and wool, were grades 5, 4 and 4–5, respectively. The dry and wet fastness are grades 4–5 and 4, respectively. In addition, light fastness reaches grades 6–7 at 3% omf dye concentration. These dye properties are better than those of commercial triphendioxazine dyes, for example, CI Direct Blue 106 and CI Reactive Blue 198, under analogous dyeing conditions.     

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.     

Investigation into the effect of a plant‐derived stabiliser on the light and wash fastness of sulphur‐dyed cotton and nylon fabrics

In this study, cotton fabric and nylon fabric were dyed with a range of commercial sulphur dyes and the light and wash fastness of the coloured fabrics was investigated. The effect of after‐treating the coloured cotton and nylon fabrics with a tannin‐based commercial product, Bayprotect Cl, in the presence or absence of sodium sulphate in the treatment bath, was found to significantly improve the light fastness of the sulphur‐dyed cotton, and the photoprotective effect was partially stable to ISO 105‐C06 washing. In addition, the tannin‐based after‐treatment also improved the colour stability of the dyed fabrics to the perborate‐based ISO 105‐C06 washing. The possible mechanisms for the improved fastness properties are also discussed. The application of sulphur dyes to nylon is potentially commercially useful but has been limited because of the reported poor light fastness of the dyeings. The photoprotective effect of the tannin‐based after‐treatment was investigated with a view to providing the necessary commercial performance. However, it was established that on this fibre, the light fastness improvement was marginal, and the associated wash fastness to oxidative bleach‐based ISO 105‐C06 washing was limited.     

Using carbon black nanoparticles to dye the cationic‐modified cotton fabrics

Carbon black (CB) aqueous dispersion was prepared and used to dye the cationic‐modified cotton fabrics through exhaust dyeing process. The effects of CB concentration, CB nanoparticles size, dyeing bath pH, dyeing time and dyeing temperature were investigated. The color yields of dyed fabrics were evaluated on Kubelka‐Munk value K/S. The surface morphologies of cationic modified and nonmodified cotton fabrics were measured by video microscope. The fabrics presented 18.9 of the color yield with the dyeing conditions: the dyeing solution contained 2% o.w.f. CB and dyeing at 80°C for 30 min with pH 13 using a 50 : 1 liquor ratio. The images of the video microscope demonstrated a clear surface profile for the cationic‐modified cotton fabrics dyed with smaller CB particle size solutions. These results indicated that CB nanoparticles were suitable for dyeing the cotton fabrics. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Application issue of anthraquinonoid vat dyes on inherently flame-resistant fabrics

The vat dyeing process of specific fabrics with protective, inherently fire retardant properties that have a high content of aramid fibres in their composition, is presented. The research was performed on fabric samples that differ in raw material composition and aramid content. The samples were dyed in raw form (group 1) as well as after pretreatment with alkaline scouring (group 2). Measured limiting oxygen index (LOI) values showed that the selected fabrics meet the properties of inherently fire retardant fabrics. Dyeing was performed with Indanthren® Olive Green HB (manufactured by DyStar) vat dye, in exhaustion process, with a bath ratio of 1:30. The dye concentration was 3%, and sodium-hydrosulphite (Na₂S₂O₄) was used as a reducing agent. The colouristic analyses were performed based on spectrophotometric measurement and results interpretation according to CIELab system. The evaluation of primary tactile properties was performed which show an increase of smoothness and softness after scouring and dyeing. Also, wash fastness as well as light fastness tests have shown satisfactory fastness properties.     

Eco‐friendly pretreatment of silk fabric for dyeing with Delonix regia extract

The flowers of Delonix regia have been evaluated for the natural dyeing of silk using a biomordant and enzymes. This is an eco‐friendly textile pretreatment that does not utilise metal mordanting. The aqueous extract obtained from the dried red flowers was used for the dyeing of silk fabrics. A bright reddish‐brown hue colour was observed when 30% owf Delonix extract was used on the pretreated silk material. The silk fabric was treated with either an enzyme or biomordant. The resulting dyed fabric showed resistance to fading. Finally, all dyed specimens were tested for wash and light fastness properties, making Delonix a viable alternative to synthetic red dyes. Through desorption studies, the order of reactivity of enzymes towards dye uptake in the one‐step process was found to be lipase > diasterase > protease–amylase = Pyrus(biomordant). For the two‐step process, the order of reactivity of enzymes was found to be protease–amylase > lipase > Pyrus (biomordant) > diasterase. Overall, it can be concluded that, treatments, the two‐step process was better in terms of larger colour yield values, fastness properties and both dye adherence ability.     

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.     

Carrier dyeing of polyphenylene sulphide fabric with disperse dye

Polyphenylene sulphide is considered to be a high‐performance thermoplastic material and has been used in many areas over the past few decades. But the application of polyphenylene sulphide fabric used for protective clothing is limited because of difficulties in its dyeing and printing. In this work, carrier dyeing of polyphenylene sulphide fabric with disperse dye is discussed, and the effect of the structure of the carrier, dyeing temperature, dyeing time, usage of carrier and usage of dye on colour strength of the dyed sample and the percentage of dye exhaustion were investigated. In addition, the glass transition temperature, crystalline structure and orientation degree of treated polyphenylene sulphide fibre with benzyl benzoate were measured by differential scanning calorimetry, X‐ray diffraction analysis and velocity‐oriented tester, respectively. The results indicated that benzyl benzoate could increase the percentages of dye exhaustion and colour strength values, while at the same time reduce the glass transition temperature and orientation degree of the treated polyphenylene sulphide fibre. Thus, it would be beneficial to the diffusion of the dye molecules into the amorphous region of the fibre. Furthermore, the decrease of tensile strength and limiting oxygen index of the dyed polyphenylene sulphide sample was very little, and the colour fastness and levelness of the dyed polyphenylene sulphide samples were also satisfactory.     

Optimising by response surface methodology the dyeing of polyester with a liposome‐encapsulated disperse dye

Optimisation of conditions for dyeing polyester with liposome‐encapsulated CI Disperse Red 50 was performed using response surface methodology. The effects of temperature, time, and lecithin:dye ratio on the colour strength of dyed fabrics were investigated by a central composite design. The coefficient of determination, the probability value in analysis of variance, and the normality plot of residuals demonstrated sufficient significance of the proposed fitness function. It was found that the temperature and time of the dyeing cycle were effective factors in the dyeing of polyester fabrics with encapsulated dye. It was also established that the colour yield of dyed fabrics was above 25 in the case of a dyeing time of >80 min, a lecithin:dye ratio of ≤2, and a temperature of ca. 128 °C. Comparison of colour strengths produced by liposome‐encapsulated dye and commercial dye revealed that there was approximately the same build‐up on polyester. Dyeings from encapsulated CI Disperse Red 50 exhibited very similar fastness to dyeings from conventional CI Disperse Red 50.     

Investigation into the sequential application of cationic/anionic fixing agents to improve the oxidative washing resistance of CI Leuco Sulphur Black 1‐dyed cotton fabric

Sulphur‐dyed cellulosic textiles are susceptible to washing powders containing activated peracid formulations resulting in obvious fading during repeated laundering. This study presents a novel one‐bath/two‐stage exhaust finishing process to improve the oxidative wash fastness of CI Leuco Sulphur Black 1‐dyed cotton fabric. The effect of the combined Tinofix ECO and Bayprotect Cl after‐treatment was to impart better colour fastness to oxidative International Organisation for Standardisation (ISO) 105 CO9 washing of the dyed cotton compared with those dyed fabrics after‐treated with Tinofix ECO alone. In addition, while the dyed fabrics rub and light fastness performances were unchanged by the after‐treatments, some improvement in the tensile strength of the combined Tinofix ECO and Bayprotect Cl after‐treated fabrics was observed.     

中空涤纶针织物的高温染色工艺研究

简单介绍了常用涤纶织物的染色方法,并通过正交试验,分别选择固色温度、助剂质量浓度、固色时间三因素的三个水平,确定出分散染料染中空涤纶针织物时的最佳高温染色工艺为:染料浓度2%(o.w.)f,浴比1∶20,固色温度130℃,固色时间60 min,助剂质量浓度1 g/L。对染色前后织物的顶破强力、保暖性能、透气性能进行了测试,得出染色后织物的强力没有明显变化,保暖性有所提高,透气性略微下降。     

One‐bath union dyeing of wool/polytrimethylene terephthalate blends†

The one‐bath dyeing of blends of polytrimethylene terephthalate (PTT) staple and wool has been investigated. The exhaustion of selected Terasil disperse dyes on PTT fibre and Lanasol reactive dyes on wool was measured as a function of temperature, together with the cross‐staining of the Terasil dyes on the wool component and the Lanasol dyes on PTT component. Most Terasil disperse dyes achieved satisfactory dye uptake on PTT at 110 °C, whereas on conventional polyester (polyethylene terephthalate) temperatures of up to 130 °C are required. An optimised union‐dyeing technique for wool/PTT blends was developed which minimised the staining of Terasil disperse dyes on wool and produced dyed goods with high levels of wet colour fastness. Carriers were not required to enhance the dyeability of PTT at low temperatures. The wool component appeared to be protected against damage at 110 °C by the reactive dyes. The results indicate the potential for blending PTT fibre and wool to produce fabrics that are easier to dye at lower temperatures than conventional wool/polyester blends.