No salt and low salt reactive dyeing Research

Keywords: reactive dyes without salt and low salt dyeing research Wangdong Wei Wang Qing Yuan Liu America (1. Zhongyuan Institute of Technology, Zhengzhou 450007, China; 2. Donghua University, College of Chemistry and Chemical Engineering, Shanghai 201600) Abstract: In the traditional dyeing process, the activity dyes cellulose fibers require a lot of salt added to increase the dye rate and fixation rate. addition of salt led to deterioration of water quality, destruction of ecological environment, and therefore no-salt and low salt reactive dyeing of a dyeing and printing workers committed to to solve one of the hot issues. In this paper, dyes developed modified cellulose fibers, dyeing auxiliaries, dyeing four aspects of salt-free dyeing techniques described the recent research and analysis were summarized. Key words: reactive dyes ; no salt and low salt dyeing; dye structure; cellulose fiber modification; dyeing auxiliaries; dyeing process CLC: TS193 Document code: A yield of cellulose fibers is the world's largest textile fibers, and dyes have become cellulose fiber textile dyeing the most important class of dyes. reactive molecular structure of simple, bright color, chromatography is complete, easy to use, low cost and excellent fastness. But the most prominent problem is that reactive dye uptake and fixation rate dye is not utilized in the traditional dyeing process, in order to improve dye uptake and dye color to color, need to join a large number of inorganic salts to promote dye, according to the structure of dyes and dyeing fabrics of different nature, the amount of salt range of about 30 ~ 150g / L. joined the large amount of neutral salt, so that serious environmental pollution caused by dyeing wastewater. From the ecological point of view, the high salt content of wastewater discharged directly altered the water quality of lakes, damage to the environment. salt The high permeability will lead to soil salinization around rivers and lakes, reducing crop yields. followed by the salt waste of resources and increase costs. current printing and dyeing wastewater treatment of organic compounds has made great achievements. but salt The deal is still in the preliminary study stage. desalting process at home and abroad have been using ion exchange desalting technology and membrane separation technology. ion exchange technology research and application have been reported, but the membrane separation technology in printing and dyeing wastewater treatment application also tentative. In short, by physical chemical and biochemical methods can not be achieved in printing and dyeing wastewater degradation and recycling of inorganic salts. Based on this, in recent years, non-salt and low salt reactive dyeing printing workers have become a hot topic of research 1. This paper systematically expounded no salt and low salt reactive dyeing the feasibility and the realization of such a dyeing process of different ways. 1 dye structure developed in recent years, mostly low-salt reactive dyeing higher immediacy, in ensuring levelness of dye solubility and the premise, the number of sulfonic less. In order to improve dye fixation and fixation efficiency rate, low salt stain or dye belong to the dual-reactive dyes. dyes on acid base number of the more fiber the greater the charge repulsion and reduce the direct nature of the more notable, whereas the more hydrophobic groups, aromatic ring plane arrangement of the stronger, the higher the dye immediacy, the lower the salt content. If the introduction of urea in the dye-based parent, an increase of dye molecules coplanar, thereby increasing its direct nature, reduce the amount of salt, but the immediacy is not too high, otherwise it would be difficult to wash than hydrolysis of dyes. dye active group reaction activity increased, dye fixing rate increase, the activity of dye fiber af smaller increase dye penetration to the concentration gradient within the fiber, so that dyes easy to dye fiber. In order to reduce or eliminate the dye and fiber between the negatively charged molecules repulsion, in recent years has developed a cationic dyes. by the basis of the traditional reactive type of water-soluble cationic group to replace the original water-soluble dyes in anionic groups, such as replacing dyes with quaternary ammonium salts of sulfur acid group. At present more than one-chloro-triazine and vinyl sulfone reactive group of the reactive dye based. more dyes can be dyed without salt conditions, because the dye carried by the positive charge makes a great dye and fiber affinity. with the first structure of the dye application performance is better than the second structure of the dyes, the first structure of pyridine group was introduced as a solubilizing group, and connect through the fat interval alkanes chromophore. In alkaline conditions, the pyridine group and breakup, which can avoid the introduction of positive charge caused by reduced light-fastness of dyed fabrics problem.================= # # # page ###@=================In addition, the reaction of fluorine-containing reactive double high. Such dyes can be low in the low-alkali salt bath staining than the staining conditions, the final fixation rate can reach 80% to 95%. If all the double use of fluoride-triazine reactive dyes, and applications without increasing the cost of production, based on reducing the use of inorganic salts Liang 12.5 ~ 25 tons / year. But dye Di Intermediate result of such equipment not corrosion serious Bingju meet environmental standards, Suo Yi fluorinated dyes by further studies. With multiple Reactive Dyes, such as the MCT/SES, can implement neutral conditions in low salt staining. However, such dyes have high activity, likely to cause uneven dyeing and dyes will increase the amount of the cost increase. 2 cellulose fiber modification on the fiber was modified at times in the past can only be temporary so that the fibers with cationic, fiber and quaternary ammonium cations formed by dissociation of the dyeing process is easy, dyeing with different dyeing conditions changed greatly, dyeing properties unstable. In recent years, the most common change of reagents with fiber by covalent bonding. That is, the introduction of amine salt or quaternary ammonium salt with fiber epoxy hydroxyl reaction, after this modified cationic cellulose fiber with a permanent, stable dyeing properties. Such as the compounds with triethanolamine to modification, or ethyl chloride hydrochloric acid diammonium salt B to modification, generate diethylamino ethyl cellulose, the fiber of the highly reactive response. As the tertiary amine base, fixing rate significantly speed, because it has its own De catalyst, can enhance the solid color reaction. Zongti aminoalkyl of cellulosic fibers connected after, not only for reactive dyes in response to Xing Da Da enhanced Er Qiezai after acidic medium of the proton to form ammonium of cation, anionic dye adsorption can be located. epoxy amine or quaternary ammonium cation and other cationic agents for small molecule agents, permeability, conducive to leveling through the dye, but a large amount. so people have tended to study large molecules and polymers cation of multi-reactive reagents. such as the cationic crosslinker DE, containing several very lively reactive epoxy functional group, and also contains several cationic quaternary ammonium salt groups, can be used for soybean fiber and cotton fiber blends modified to salt-free dyeing. There is also a synthesis of chlorine-triazine and epoxy propyl more reactive groups of reactive cationic compounds as modification reagents. TETS is a new multi-functional cross-linking amine reagent, molecular contains a tertiary amine and 3 reactive groups, in alkaline conditions, with fiber-OH on the occurrence of crosslinking reaction, the tertiary amine is introduced into the fiber. The polyfunctional crosslinking agent, and cellulose fibers crosslinked network, in addition to improving the dyeing properties of fibers, the fibers of such cross-linking agent can also improve other properties, such as anti-wrinkle and anti-bacterial and so on. As many cationic reagent itself is detrimental to the environment, Some amines such as toxic substances in nature, large eyes, skin, respiratory tracts, have a stimulating effect. Therefore, the development environment-friendly biomass cationic chemical reagents has been more attention. chitosan derivatives with NMA-HTCC ( containing quaternary ammonium) to deal with cellulose fibers, made of modified fibers in both activity of cationic group, can be dyed without salt conditions. can be given to antimicrobial resistance and crease-resistant fabrics to improve fabric moisture permeability. At the same time The fastness also increased, but decreased light fastness after dyeing. Synthesis of low viscosity with high direct drying of cationic starch hydrolysis, the compounds are used in the pretreatment of cotton fabric, used in the synthesis of tert-modifier amine or quaternary ammonium ether as an agent of starch hydrolysis, this reagent low price, good performance, biodegradable, and can be used for reactive dyes exhaust staining. by the starch and glycidyl trimethyl ammonium chloride made of cationic starch Modification of the fiber is mainly used for dyeing of reactive dyes, but is better when applied to exhaust dyeing levelness poor. more fiber is the fiber was modified cationic so that in the mechanism of dyeing with reactive dyes occurred great changes, due to positively charged form of fiber to dye anion easily be adsorbed to the fiber surface, so as to achieve the purpose of dyeing without salt. In addition to cationic modified fiber, but also can be modified by other methods. such as the use of poly acrylamide on the pretreatment of cotton fibers to make cellulose hydroxyl partially changed into amide, which will lead to cellulose fibers like wool fibers from the role, equivalent to the use of reactive dyes as acid dyes, which can be achieved salt-free dyeing of cotton fabric. but this time the fastness of dyed goods will be affected to some extent.=================@### page ###@== ===============3 to change the dye color dyeing auxiliary structure can not be achieved fully without salt stain, and modified cellulose cation there is on the fiber properties or dyeing properties instability and levelness problems. So people in recent years has done a lot of dyeing auxiliary work, a series of salt-free dyeing synthetic cross-linking agent that cross-linking agent in the dyeing process of the formation of dye and fiber cross-linking of bond, in fact, these additives are mainly used to improve the color fastness of dyed fibers. for cationic modified cellulose reagents, most of the cross-linking agent can be used as a salt-free, its mechanism similar to the fixing agent solid color, or additives and dyes and also the formation of covalent cross-linked fibers to improve the utilization of dye. the traditional use of the crosslinking agent is formaldehyde containing compounds, such crosslinking reaction is good, but the toxic substance . Later, synthetic and ultra low formaldehyde cross-linking agent formaldehyde, but these substances containing N-hydroxymethyl, at high temperatures will release formaldehyde. In recent years people have synthesized a series of non-formaldehyde crosslinking agent, its molecular Compounds containing reactive or active group. mainly the following categories: (1) 1,3,5 - acrylamide hexahydro triazine FAP. but the poor directly, do not dissolve in water, needed dispersant to improve their reactive; (2) N, N-dimethyl acrylamide Asia (MBA); (3) epoxy compounds, generally more glycidyl amine compounds containing two or more epoxy-based, cross-linking after staining brightly colored fabric shade, wet fastness and feel better. but poor stability, high price; (4) activity of vinyl compounds, such compounds is represented by the two vinyl sulfone and the saturated material. divinyl sulfone in alkaline medium and temperature conditions, can be crosslinked with the cellulose fibers can also be in the alkaline (pH = 7 ~ 9) and wool under the thiol reaction high, cross-linking effective. 2 vinyl sulfone derivative of saturation is a basic non-toxic, non-volatile water-soluble compounds can be used for dyeing fabrics crosslinking; (5) multi-isocyanate esters, such crosslinking agent system containing two or more highly unsaturated isocyanate (-N = C = O) of alkanes or aromatic compounds, easily and with hydroxyl, amino compounds and other active hydrogen atoms linked into a three-dimensional structure; (6), cyanuric chloride and its derivatives, use cyanuric chloride three chlorine atoms of different lively, and the fibers of the-NH2 (-OH), dye-NH2 in the reaction of condensation polymers. As the three chlorine atoms in the role of different conditions, making dye and fiber cross-linking efficiency. In addition to no-salt crosslinking agent, the use of organic salt instead of salt for reactive dyeing began to study. early use of EDTA (ethylenediaminetetraacetic acid) as the reactive dye-promoting agent, although in this case to achieve the objective of biodegradable, but organic salts such as acid alkali salt, alkaline hydrolysis of reactive dyes accelerated, process difficult to control. sodium citrate promote better dyeing effects on the environment friendly, but expensive, not suitable for industrial production. has recently been with the organic polycarboxylic acid sodium salt as the accelerant to study the use of sodium polyacrylate (PA) and sodium salt polymaleic (PM) of the mixture as accelerants. polycarboxylate toxicity, raw materials are cheap, equivalent sodium ion concentration in such conditions, the dyeing effect and the effect of NaCl equivalent and the color fastness is also not greatly affected . 4 dyeing proper design and control of salt-free dyeing process is also an important means and low salt dyeing. from the dye adsorption kinetics and thermodynamics know that the direct nature of dye and the dyeing temperature and liquor ratio, the lower the direct nature of dyeing temperature The higher the amount of the less need for salt. but the temperature is too low will reduce the solubility of dyes and dyeing rate, and therefore must use the appropriate additives to improve the dissolution and dispersion of dye, to speed up the dye and fixation rates . bath than the smaller of the higher direct dye, the less amount of salt. In recent years, also used for dyeing the field of electrochemical research. dyes in water can be dissociated into anion, suitable voltage applied to the dye. With electrode potential difference between relying on the directional ion ions through the enhancement of dye penetration, it will undoubtedly enhance the dye, while allowing sodium ions move in the opposite direction, instead of having the fiber's surface cation barrier, thus Do not add salt when dyeing dyeing acceleration. But this process of research is only in theory stage, there is a range of issues, such as the choice of electrochemical parameters. In addition, the emerging micro-suspension dyeing process, this technology is mainly used in wool dyeing wool with reactive process, that is, adding the process of dyeing auxiliaries micro-suspension of EX-1 and EX-2, these additives to the aggregation state of dyes to a very small presence, at low temperature, the dye adsorbed on the fiber surface can be large, but the dye bath temperature is increased dye molecules released from the micro-suspension, fully puffed quickly spread to the fibers, without salt to promote dye, this method can reduce the dyeing process of wool fibers injury.=================@### page ###@=================5 Conclusion As the requirements of environmental protection and clean production, no salt and low salt dyeing dyeing technology is today a trend. In order to achieve this process paper fiber from the dye structure modification of dyeing auxiliaries and dyeing four aspects are discussed. in dye synthesis side mainly in the dye into the mother in some groups, most notably the synthesis of cationic dyes. But with the complexity of the structure of dye its cost will increase. modification of the fiber is the fiber of the cations of the major changes nature of the modified fibers can be achieved in the absence of salt under the conditions of dyeing, but the modification will extend the process time, and sometimes modified fiber mechanical properties will be affected. In the dyeing auxiliary, the synthesis of a large number of currently cross-linking, despite the environmental compliance of the cross-linking agent, but its performance varies with different cross-linking, the main problems is handled by the shade of dyed goods sometimes change. some new dyeing also only at a preliminary stage of exploration. theoretical results of the current study was not extended to the actual large-scale production. how to dye the nature of the fiber and dye requirements, selecting technology, lower costs, the key to the realization of industrial production. Benwen Transfer from:

分类:Industry 时间:2010-02-18 人气:489
blog comments powered by Disqus


iOS 开发

Android 开发

Python 开发



PHP 开发

Ruby 开发






Javascript 开发

.NET 开发



Copyright (C), All Rights Reserved. 版权所有 闽ICP备15018612号

processed in 0.052 (s). 11 q(s)