The Covalent Reactions of Primary Amino Side-chains and Disulphide Bonds in Wool Keratin

Previous work on the reactions of different types of reactive dyes with wool is reassessed and new jindings presented. The decrease in reactivity of basic wool side chains to reaction with 1:fluoro:2:4 dinitrobenzene after wool has been dyed with acidic or reactive dyes is further investigated. New and previous correction factors measuring the extent of this inactivation are compared. Using such corrections, the extent of actual covalent binding of reactive dyes to basic wool side chains is determined. Applying these corrections gives reasonable stoichiometry in the dye-fibre reaction. The extent of reaction of thiols, basic and hydroxyl groups in wool with five reactive dyes of different classes has been measured, and compared for two dyeing methods (long-liquor and urea pad-batch). The differences and similarities in the extent and type of reaction of the dyes with the fibre sites, using the two methods of application, is discussed. The role of disulphide degradation in reactive dyeing is further investigated. The effect of alkaline treatments on the fixation of reactive dyes, and the availability of wool lysine side-chains for reaction (in the urea pad-batch dyeing system) is reported upon.     

羊毛活性/分散染料染色染料相互作用研究

在一定工艺条件下，用活性染料染羊毛，再用分散染料套染，其K／S值大于单独使用活性和分散染料染色的K／S值之和，活性染料对羊毛起到了改性作用，使分散染料染色湿牢度有显著提高。随着活性染料浓度的增加，分散染料的上染率也增加。用分散染料套染活性染料，其匀染性相对于单独使用活性染料有提高。     

Mechanism of Reaction of Proteins with Reactive Dyes:I-Literature Survey

The chemistry of reactive dyes and wool keratin is described briefly. Published investigations of the mechanisms of dyeing of wool and other protein fibres with reactive dyes are discussed and compared.     

活性染料用于拉细羊毛染色的研究

研究了四类活性染料染拉细羊毛的工艺条件和十二个染色配方。与媒介染料相比，用活性染料对拉细羊毛染色可获得更好的效果。染料的溶解度、匀染性、上色率、固色率均好于媒介染料，颜色的批差小。研究结果表明：除煮呢沾色牢度外，染色羊毛的各项牢度均优于媒介染料。     

Instrumental Colour Prediction A Potential Aid to Dye and Process Selection

A relationship has been established between the dyeing properties of fibre–reactive dyes and the spectral reflectance properties of the colours produced on machine–washable wool. The information gained in routine dye calibration for instrumental colour–prediction systems may be used by the practical dyer for dye selection. The spectral reflectance properties of the resultant dyeings are explained in terms of the diffusion, fixation and level–dyeing properties of specific fibre–reactive dyes applied to wool by exhaust and pad–dyeing processes.     

锦纶66微纤维活性染料染色条件探讨

采用毛用和棉用活性染料对锦纶66微纤维染色,详细讨论了染色温度、染浴pH值、染色和皂洗方法对染色深度和固色率的影响,分析了不同类型的活性染料对染色条件的敏感性。活性染料对锦纶66微纤维的染色深度、固着率和固着效率受温度、pH值、染料母体结构和活性基的影响很大。毛用活性染料更适合于锦纶66微纤维的染色,普通乙烯砜硫酸酯及乙烯砜硫酸酯/一氯均三嗪染料可有选择性地加以使用,毛用活性染料合适的染色pH值约为4,其它染料适用的pH值因品种而异。采用酸性染色或先酸性后碱性的染色条件均可,后者的优点是固着效率高,但染色深度未见提高染色后采用碱性条件皂洗有利于染色深度的提高。     

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.     

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.     

Research in the cold pad–batch dyeing process for wool pretreated by hydrogen peroxide

The cold pad–batch dyeing process of wool pretreated by hydrogen peroxide was carried out with Lanasol reactive dyes and Realan reactive dyes. The influences of various conditions of the dyeing process, including urea dosage, sodium bisulphite dosage, pH value, batching time and the liquor pickup on colour yield, were analysed. Fixation, levelness of dyeing, dye penetration, colour fastness, breaking strength and elongation were compared between untreated and treated wool fabrics. The study showed that cold pad–batch dyeing of wool fabric is a good prospect for future use because of the resulting advantages, such as higher fixation yield, less energy usage and lower sewage discharge.     

Investigation into the dyeing of wool with Lanasol and Remazol reactive dyes in seawater

Freshwater is an increasingly scarce resource that is extensively used in textile wet‐processing. In seeking to identify alternative low freshwater‐usage coloration technology, this study examined the potential use of seawater (SEAW) as the dyeing medium for wool coloration using a range of reactive dyes. Initially, the dyeing behaviour of the wool fabric in simulated seawater (SSW) was compared with conventional dyeing from distilled water (DW) using α‐bromoacrylamide‐based Lanasol dyes and sulphatoethyl sulphone‐based Remazol dyes. These preliminary studies demonstrated that comparable coloration could be achieved in the SSW medium based on an assessment of the dye exhaustion, dye fixation, colour yield and levelness. Subsequent dyeing studies of wool using Mauritian seawater with both the Lanasol and Remazol reactive dyes confirmed that, based on the dye exhaustion, dye fixation, colour yield and levelness, comparable coloration could be achieved, highlighting the possibility of substituting freshwater with seawater as the dyeing medium.     

Synthesis and Application of Some New Reactive Chlorohydrin Dyes

Azo and phthalocyanine dyes carrying the chlorohydrin group, as the precursor of the reactive epoxy group, were prepared using new catalyzed reactions. The reactive group is attached to the coupling component in some cases and to the diazonium component in other cases. A phthalocyanine dye carrying two reactive groups was also synthesized. The dyeing of cotton, wool and multifibre fabrics was studied, under different dyeing conditions. Various techniques of dyeing and printing were used. Exhaustion and padding methods were investigated for dyeing, and direct, reserve and discharge methods for printing. One–stage and two–stage procedures were employed for both printing and dyeing. It was found that the chlorohydrin reactive dyes prepared in the present work could be applied by nearly all known methods of dyeing and printing on cotton, wool, viscose rayon, nylon and acrylic fibres. The dyeings obtained had satisfactory fastness properties and showed fairly good dye fixation on the substrate.     

Reactive dyeing systems for wool fibres based on hetero-bifunctional reactive dyes. Part 1: Application of commercial reactive dyes

The wool dyeing properties, such as exhaustion and fixation parameters, of selected hetero-bifunctional Sumifix Supra dyes and some other commercial reactive dyes were quantified under various dyebath pH conditions. Studies of the dyeing of wool serge fabric indicated that Sumifix Supra dyes could produce reasonably high fixation values. However, remarkably improved fixation values were obtained when these dyes were pre-activated to the vinylsulphone form and dyed in this form, especially at low pH values (pH 4 or lower).     

The effect of reactive dyes on damage in wool dyeing

This paper demonstrates that reactive dyes exert a significant fibre–protective effect when dyeing wool fabric; this effect may be measured, in a reproducible manner, using the wet–burst strength test. The effect of dyebath pH, dye concentration, dyebath temperature and dyeing time on wool can thus be evaluated. The magnitude of the above protective effect has been compared with that achieved using commercially available fibre–protective agents. It is concluded that reactive dyes are significantly more effective than the latter agents when employed in medium to full depths. It is proposed that the unusual protective effect afforded by reactive dyes is related to the following factors. Reactive dyes readily react with sulphur nucleophiles, thus inhibiting thiol–disulphide interchange reactions and thereby significantly interfering with the level of set produced in a boiling dyebath. Reactive dyes react preferentially with non–keratinous proteins in the intercellular cement and the endocuticle thus reducing their tendency to hydrolyse and to partially dissolve in the hot aqueous dyebath.     

Reactive dyeing systems for wool fibres based on hetero-bifunctional reactive dyes. Part 2: Investigation of dyeing properties during the dyeing cycle

The dyeing behaviour during the dyeing cycle of a Sumifix Supra dye and some other commercial reactive dyes under various dyebath pH conditions was investigated. Studies of the dyeing of wool serge fabric indicated that the diffusion properties of hetero-bifunctional Sumifix Supra dyes generally lie between those of b-sulphatoethylsulphone (Remazol dyes) and monochlorotriazine (Procion H dyes).     

Production of Fast Dyeings on Resin-treated Wool

The dyeing properties of wool treated with Hercosett 57 resin to render it machine-washable have been studied. It has been shown that this reactive highly basic resin can greatly improve the dyeability of wool. Reactive dyes have excellent properties on this wool. Differential-dyeing and fully continuous dyeing processes, using the special properties of Hercosett-treated wool, have been studied.     

The Dyeing Properties of Monoazo Reactive Disperse Dyes Derived from –Chloro–4–aminoacetophonone on Polyester Fibre Blends

The preparation of monoazo reactive disperse dyes from –chloro–4–aminoacetophenone and the dyeing properties of these dyes on polyester–cotton and polyester–wool blends are reported.     

The Dyeing of Wool–Polyester Blends with Reactive Disperse Dyes

The dyeing behaviour of the Procinyl (ICI) range of reactive disperse dyes on wool–polyester blends is described. Two of the dyes were found to dye both components of such blends to approximately the same depth, whilst the remaining three dyes in the range strongly favoured the wool component.     

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.     

壳聚糖在活性染料染羊毛织物上的应用工艺探讨

本文对壳聚糖处理过的羊毛织物用活性蓝BET染色工艺进行了探讨.讨论了壳聚糖脱乙酰度、壳聚糖浓度对羊毛染色性能的影响,并比较了经壳聚糖处理与未处理羊毛染色性能的差异.结果表明,提高处理液中壳聚糖的浓度或脱乙酰度都能提高活性染料的固色率,提高织物表面色深值K/S,而且对染色样的各项牢度影响不大.     

Improving the dyeability of wool by treatment with chitosan

A study of pretreatment of wool fabrics with chitosan by a pad-dry method has been carried out. The pretreatment effectively eliminates differences in dyeing behaviour between damaged and undamaged wool fibres, with an increase in the rate of dye uptake and the exhaustion of acid and reactive dyes. Penetration of the fibre by dyes has been followed using fluorescence microscopy and the role of the chitosan coating in the dyeing process clarified. Similar colour fastness properties were obtained on both untreated and chitosan-treated wool fabrics. The chitosan coating on wool fabrics has been examined by scanning electron microscopy. Evidence for the presence of chitosan was sought using a colorimetric method. It is believed that an approximately uniform and adherent chitosan sheath is formed on individual wool fibres.