Talk about: the importance of green dyes.

Since the middle of the 20th century, science and technology have entered a period of rapid development on a global scale. At the same time, more and more people are worried that the predatory exploitation of global resources and the large amount of "three wastes" discharged with the development of industrialization have seriously damaged the living environment of human beings and threatened their survival and health, so people are increasingly aware of the importance of environmental protection.

1968 In March, Director Gundam of USAID delivered a speech entitled "Green Revolution: Achievements and Worries" at the annual international development conference, which fully affirmed the achievements of world economic development, but at the same time expressed concern about the destruction of the ecological environment such as the earth, atmosphere and ocean, and put forward the concept of "green revolution" for the first time. In the following decades, "green" became synonymous with less pollution and no pollution. Green food, green agricultural products, green fibers and green textiles have come out one after another, and gradually set off a "green wave" on a global scale.

It has become a worldwide trend to provide consumers with products that are safe and beneficial to ecological and environmental protection. The trend of paying attention to green consumption has affected textiles and clothing. The development of textile and garment production, in addition to the technical progress of production technology, the application of a large number of dyes plays an important role in improving various wearing functions. However, some of these dyes are not only harmful to human body, but also very harmful to the protection of ecological environment, which has aroused widespread concern of consumers and is called "toxins in the wardrobe".

Since the 1980s, developed countries have begun to conduct a comprehensive study on the possible harmful substances in textiles and their effects on human health and the environment. Technical standards for monitoring harmful substances in textiles have been put forward one after another, and regulations were formed in the 1990s. For example,1July, 1994, the Food and Consumer Goods Law (the second amendment) of the German government, the Oeko-TexStandard 100 of the same period and the Eeo-Label (eco-label) eco-textile technical standard of the European Union in the late 1990s. Harmful substances included in the monitoring scope of eco-textiles include pesticides, carcinogenic dyes, sensitizing dyes, extractable heavy metals, formaldehyde, preservatives, chlorine-containing organic carriers, PVC plasticizers, organotin compounds, flame retardants and other chemicals that can reduce and decompose carcinogenic aromatic amines. Therefore, the essence of green textiles is green chemistry or green dyes.

With the increasingly fierce competition in international textile and clothing trade, green textiles will dominate the new trend of international textile and clothing trade and dominate the international textile and clothing trade market. Developing and applying green dyes to make textiles and clothing meet the requirements of ecological environment protection is the most important factor to develop green textiles.

The bifunctional dyes of monofluozine and vinyl sulfone are Cibacron C and FN of ciba specialty chemicals company. It has the advantages of high fixation rate, good levelness, good washability, easy washing, good fastness and insensitivity to process conditions.

There are 16 varieties of cibacron type c, such as: cibacron yellow C-5G, (c.i. yellow 175), yellow c-5g (c.i. yellow 175) and yellow c-r (c.i. yellow 66). Orange C-G, orange C-Br (c.i. active orange 133), brown C-RN, red C-4G, RedC-2G, red c-b, (c.i. red 235), red C-2BL, red c-r (c.i.

Cibacron FN was launched during 1996- 1997. The fixation rate is above 80%, and it does not contain carcinogenic aromatic amines and AOX. It has good levelness, diffusibility, compatibility and reproducibility, can be dyed at a low bath ratio of 1: 10, and has high wet fastness and various fastnesses. There are 16 varieties. For example:

The tricolor dyes are cibacron yellow fn-2r (reactive yellow 206), red fn-r (reactive red 238), blue fn-r (reactive blue 235) and navy blue fn-b (reactive blue 238). Auxiliary color dyes include: cibacron orange FIN-BR, yellow fn-3f (C.I reactive orange 9 1), yellow FN-4G, red FN-3G, (c.i. reactive red 266), red FN-B, orange FN-R, scarlet FN-3G and blue fn-3g. From 1998 to 1999, Cibacron Brill. Blue FN-G and red FN-G are newly introduced. However, some variants of type C and FN are composed of the same bifunctional groups.

In order to improve the fixation rate, dyeing depth and lifting rate of dyes, three kinds of reactive dyes have been developed in recent years. For example, Cibacron RedC-2G (C.I reactive red 228) and cibacron Redfn-3g (C.I reactive red 266) contain three active groups, namely monochlorotriazine, monofluoriazine and vinyl sulfone. However, due to the increase of molecules, the dye is difficult to diffuse in the fiber, so the transfer dyeing performance is reduced, resulting in poor levelness.

B. the same bifunctional dye

There are three types of dyes with the same bifunctional group. Namely, bismonochlorotriazine, Shuang Yi fluorotriazine and divinylsulfone.

Dyes with the same active groups are first represented by C.I. Reactive Black 5 (Reactive Black KN-B) with two vinyl sulfone groups. Black sulfide and direct black dyes are gradually replaced in cotton black dyes because of their low price, good fastness, fixation rate of about 70% and good washing resistance, and become the most used black reactive dyes. However, due to low blackness and low lift, many studies have been done to overcome this defect. In 1980s, C.I. Reactive Orange 82 was added, which improved the blackness to some extent, such as domestic reactive deep black KN-G2RC 133. At present, a compound C.I. Reactive Black 5 is mixed with other orange and red reactive dyes to expand its application.

Other divinylsulfone reactive dyes, such as C.I. Reactive Orange 107, have been suggested to be mixed with C.I. Reactive Black 5 to improve the blackness.

Dyes containing bis-monochlorotriazine reactive groups include domestic KE reactive dyes, Basilen E from Procion H-E of BASF Company, Ciba CRONE from Ciba Refinery, Kayacion E from Japan Chemical Company, etc. There are two kinds of reactive groups in this kind of dyes: bridge type and bilateral type.

1984 introduced the Procion H-EXL model based on the Procion H-E model, which means excellent levelness, indicating excellent levelness. This kind of dye has good compatibility, reproducibility and easy washing, and also has high diffusion rate, high dye transfer rate and high fixation rate. The early variety is 14, which is suitable for large bath ratio dyeing. They are: Prosien yellow H-EXL, yellow-brown H-EXL, reddish-brown H-EXL, Brill. Scarlett H. Exl, Brill. Orange H-EXL, brill Red H-EXL, Red H-EXL, Red H-EXL, Blue H-EXL, Blue H-EXL, Royal H-EXL, Navy H-EXL, Amber H-EXL and Dark Blue H-EXL. 1998 has added four new varieties, which are suitable for dyeing with small bath ratio dyeing machine. Not only can excellent leveling effect be obtained, but also the dyeing effect is basically unaffected when the dyeing parameters such as bath ratio, temperature and salt dosage are deviated. They are: Pushion Emerald H-EXL, Sapphire H-EXL, Turquoise H-EXL and Yellow H-EXL. In 2003, six new varieties were introduced, namely Procion Yellow XL+ and Brill. Red XL+, Rubin XL+, dark blue XL+, cyan XL+ and navy XL+. This series of dyes has good transfer performance, levelness and reproducibility, and is especially suitable for medium and dark colors, such as deep red, brown, green and sesame color with poor color attention.

The above reactive dyes can be used in RFT(Right-First-Time) process, that is, the one-time success rate is improved. In order to achieve RFT, reactive dyes with excellent performance must be used, and whether the reactive dyes are good or not is expressed by reactive dye compatibility index RISC. The general determination is as follows: directness in neutral electrolyte, S value is 70%-80%, dye transfer rate MF value >; 90%, MLDF value of leveling factor >; 70%, and the time required to reach half fixation rate is T 1/2≥ 10min. The new and old varieties of Procion H-EXL are all within these numerical ranges, so they have good compatibility and are suitable for controlling dyeing.

Colijn's Delimarin XN is also a kind of bismonochlorotriazine dye, which is different from Pusion H-EXL in that the two active groups are linked by ethylene (-CH2CH2-), while Pusion H-EXL is linked by phenylenediamine. XN type has 12 varieties, and the three primary dyes are yellow X-4rn (C.I. Reactive Orange 70), red X-6BN (C.I. Reactive Red 243) and navy blue X-GN (C.I. Reactive Blue 2 14).

Drimarene XN also includes yellow X-RN (reactive yellow 165), orange X-3LGN (reactive orange1kloc-0/7), scarlet X-2GN (reactive red 224) and emerald X-GN (C

Ciba Specialty Chemicals Company's Ciba clone model is Shuang Yi fluorotriazine. The linking group is similar to ethylene aliphatic hydrocarbon and has flexibility. LS reactive dyes have high molecular weight, high affinity to fiber, good solubility, moderate reactivity, high binding fastness, low salt content for dyeing and low salt content. 1 1 variety, the absorption rate is over 90%, and the fixation rate is about 80%. They are yellow15-4g (c.i. reactive yellow 207), yellow LS-R (C.I reactive yellow 208), orange LS-BR (C.I reactive orange 132) and scarlet ls-2g (c.i. Red LS-B (reactive red 270), blue LS-3R (reactive blue 263), Brill. Blue LS-G, navy LS-G (reactive blue 264), green LS-3B (reactive green 32) and black LS-.

Kayacelon React CN dye developed by Japan Chemical Company is the active group of bis -3- carboxypyridine quaternary ammonium triazine, and the free group during dyeing is 3- carboxypyridine (nicotinic acid), which is harmless to the environment. Because of its high reactivity, it has high adsorption rate and high immobilization rate. It can be used for one-bath one-step dyeing of polyester-cotton blended fabric with disperse dyes, and it is a promising environment-friendly reactive dye. However, due to the high requirements of reaction control in the manufacturing process, the dye contains impurities produced by side reactions, and the source of nicotinic acid needs to be solved. There are the following varieties.

Such as: Kagacelon react Yellow CN-GL (C.I C.I. Reactive Yellow 178), Yellow CN-4g (C.I Reactive Yellow 164), Yellow CN-RL (C.I Reactive Yellow 162). Red CN-3b (C.I reactive red 22 1), red CN-7b (C.I reactive red 237), scarlet CN-GL (C.I reactive red 236), Turquoeie CN-2g (C.I reactive blue 237), and Brill. Bluecn-BL (C.I Reactive Blue 2 16) and Deep Blue CN-R (C.I Reactive Blue 2 17), etc.

(2) Development of dye matrix

The matrix structure of dyes is mainly azo type (including heterocyclic azo type), accounting for about 70%-75% of reactive dyes. Other matrix structures are anthraquinone type and phthalocyanine type. The dye matrix developed in recent years is mainly polycyclic structure, all of which are aimed at improving the dyeing depth, lifting power, light fastness, chlorine fastness and oxidation resistance of reactive dyes.

Triphenyl bis? The matrix dye of azine structure is bright blue matrix, which has excellent light fastness and good dyeing depth. Its molar absorption coefficient is 4-5 times that of anthraquinone structure, 2-3 times that of azo structure, and its fixation rate is 1.2- 1.6 times that of other reactive dyes, up to about 90%. For example, C.I. Reactive Blue 198 (Reactive Brilliant Blue KE-GN) and C.I. Reactive Blue187 (Kayacelon reactive brill). Bluecn-FL) and C.I. Reactive Blue 204(Cibacron F-GFN).

Jiayue? The dye matrix of this structure is copper complex dye, which has high complex stability and good planarity, so it has high directness, high dye uptake and high fixation rate. The products of this kind of dye M-BRE are as follows: Reactive Blue 104 (Reactive Blue KM-GR, K-FGR), Reactive Blue 2 16 (Ka Ya Theron Reactive Blue BL) and Reactive Blue 22 1 (Reactive Blue M).

Jiayue? The structure is a blue reactive dye developed earlier, and the most valuable is the metal complex structure of o-bisazo tri-integrated ring. The reactive dye with this structure is different from Jiayue. The metal complex structure of tricyclic ring is symmetrical.

In addition to high stability, this structure is mainly characterized by extremely high light fastness, reaching 7-8 grades, even for light dyes, its light fastness is still very high; Good planarity and high directness; And has good fastness to chlorine and peroxide. The commercial dye with this structure is Levafix Olive E-GLA, and its active group is 6- amino 2,3-dichloro-1, 4- quinine? Lin.

The parent dye with benzodifuranone structure absorbed the benzodifuranone structure in the new red disperse dye. Bright color, high dyeing strength and excellent dyeing performance. Commodity is summifix supra red 4bnf150% grain.

(3) Development of joint

The linking group between chromophore and active group of reactive dyes is related to the activity and other properties of dyes. The usual linking group is imino, but in the presence of alkali, due to the loss of protons on imino, the electron cloud density of triazine increases and the reactivity decreases. Therefore, in recent years, many commercial reactive dyes have changed their linking groups.

The imino connecting group between monochlorotriazine and vinyl sulfone of one-sided double-reactive dye was changed to alkylamino (tertiary amino) to prevent amino group from dissociating and reduce the reaction activity. At the same time, due to the introduction of alkyl (methyl or ethyl), the planarity between active groups and matrix is reduced, the directness of dyes to fibers is destroyed, and the levelness and washability of dyes are improved. This linker is usually found in Sumifix Supra dyes.

Two bridged monochloro (fluoro) triazines with the same bifunctional groups are condensed with diamine compounds. The common use of p-phenylenediamine shows that the whole dye molecule has a linear structure, good planarity and high directness. It belongs to high-temperature reactive dyes and is suitable for high-temperature dyeing process. Characterized by high fixation rate and excellent wet fastness; But the levelness and washability are poor. Such as KE type and Procion HE type reactive dyes.

Alkyl diamine linking groups, such as propane diamine, ethylenediamine, alkyl diamine, etc. Because of its structural flexibility, it is beneficial to improve levelness and reduce dyeing temperature. This reactive dye with linking group has high reactivity, fixation rate and lifting force. They appear in the structures of Drimarene XN dye and Cibacron LS dye.

2. Develop and apply new varieties to improve dyeing performance and fastness.

A new reactive dye for (1) low salt dyeing.

In order to maintain and improve the adsorption rate and fixation rate of reactive dyes with less inorganic salts, it is necessary to properly improve the affinity between dyes and fibers, but it will cause problems such as decreased solubility, levelness and washability of dyes. After in-depth study on the structure and affinity of reactive dyes, it is found that the amount of inorganic salts can be reduced by reducing sulfonic acid groups and using other temporary soluble groups such as β -ethyl sulfate sulfone, increasing the coplanarity of dye molecules and introducing substituents with hydrogen bonds into fibers. A new variety of low-salt dyeing was introduced. For example, the CibaERIONLS model of CIBA Specialty Chemicals Co., Ltd. has an inorganic salt content of 1/2 ~ 1/3 of that of ordinary double reactive dyes, which has excellent levelness, lifting power and reproducibility, and can be used for one-bath one-step dyeing of polyester-cotton blended fabrics with disperse dyes.

Sumitomo Corporation of Japan introduced a set of SumifixSupra E-XF dyes in 1996, which contained monochlorotriazine and vinyl sulfone. As long as 30g/l sodium sulfate is added, the same dark color can be obtained by adding 50g/l sodium sulfate when dyeing with Sumifix Supra ordinary dye, and it has excellent levelness and reproducibility. Sumifix Supra NF dye and HF dye are introduced in 1998. Not only the fixation rate is high, but also it can be dyed with low salt. The dosage of sodium sulfate is only half that of ordinary double reactive dyes, and it also has excellent dyeing fastness, washing resistance and excellent reproducibility. It is especially suitable for medium to dark dyeing, and the amount of residual dye in dyeing wastewater is only 25%-30% of that of ordinary reactive dye dyeing wastewater.

1In June, 1999, Japan Chemical Company developed a set of three primary colors of medium and dark reactive dyes. Namely: kayacion yellow e-le conc kayacion magenta e-le conc. And Kayacion blue E-LE cone. E-LE is a depleted low electrolyte system. High affinity and reactivity, high fixation rate, generally 78%-8 1%, and high dyeing fastness.

DyStar Company screened out some Levafix E-A dyes in 1997, which can reduce the amount of inorganic salts by 2/3, and the dyes have good solubility and excellent levelness.

(2) Development and application of dyes to improve dyeing fastness.

In the application of reactive dyes, the most concerned but also the most difficult problems are the light-colored printed fabrics' fastness to sunlight, the fastness to washing and wet rubbing, the fastness to chlorine and the fastness to perspiration. To solve these problems of dyeing fastness, besides the rationalization of printing and dyeing process and the application of auxiliaries after dyeing, the selection of dyes and the development of new varieties play a vital role.

Dye itself is the most important factor affecting the light fastness of light-colored fabrics, so the choice of dyes is the most important, and the role of auxiliaries can be ignored. Among tricolor dyes and yellow reactive dyes, the light fastness of parent chromophores such as pyridone, pyrazolone and naphthalene trisulfonic acid can reach 6-7 grades. For example: C.I. Reactive Blue 50, 69, 74, 94, etc. The turquoise blue spectrum of phthalocyanine, such as C.I. Reactive Blue 14, 15, 63, 23 1, etc. The dark blue spectra of the structures, such as reactive blue 104, blue 220 and blue 22 1, etc. The light fastness of the above three blue reactive dyes can reach 6-7. The light fastness of reactive dyes in red spectrum is generally low, especially for light-colored fabrics. For example, Megafix red PBL can reach grade 5-6 at the concentration of 0.05%- 1.0%(owf). CibacronRed FN-2BL is 5-6 at 1/6 standard chromaticity. Drimarene Rubine CL-3BL can reach grade 5-6 under the standard chromaticity of 1/25. Evergol red C-3B in Yong Guang, Taiwan Province can reach 6 levels at the depth of 0.0 1-0. 1%(owf), and it is matched with Evergol yellow C-GL and Evergol blue C-2B. The dyeing depth of the above dyes can reach 6 levels.

The wet rubbing fastness of deep dyed fabrics with reactive dyes is related to printing and dyeing process, fabric structure and fabric surface smoothness, and it can also be improved by treating with auxiliaries after dyeing. However, the choice of dyes is very important, and we should pay attention to two points: first, try to reduce the floating color on dyed products to facilitate cleaning; The difference between the final dye uptake and the fixation rate shall not exceed 150%, and the fixation rate shall not be less than 70%; In order to wash off the floating color easily, it is necessary to choose reactive dyes with primary dye uptake below 75% (before adding alkali). Secondly, the high concentration of dyes used in dark dyeing leads to the increase of floating color, so we should choose dyes that can reach the required depth and use less, that is, dyes with high lifting power. In recent years, reactive dyes with multiple reactive groups have been developed, such as cibacron. The lifting power of crimson S-B is about 3 times that of commonly used better reactive dyes, such as C.I. Reactive Red 239, 195. Other reactive dyes, such as Ciba Red C-2G (C.I Reactive Red 228), Ciba Red FN-3G (C.I Reactive Red 266), etc.

The perspiration fastness of reactive dyes has attracted much attention in recent years. Some reactive dyes have good perspiration fastness, but poor perspiration fastness. Due to the different fading mechanism under the dual action of sweat and sunlight, the general reactive dyes and metal complex reactive dyes can not meet the fastness requirements due to the reduction of lactic acid and the integration of amino acids in sweat. In recent years, some reactive dyes with good perspiration light fastness and no metal complex have been screened and developed. Such as ProcionElmerald, Sappbire, Turquoise and Flvine H-EXL, have excellent fastness to perspiration and chlorine. Sumifix SupraHF and NF series, Kayacion E-LE series and DrimareneCL-C series dyes can all reach the perspiration light fastness of 4-5.

1On July 5th, 994, the German government banned for the first time the production, use and sale of azo dyes that can reduce carcinogenic aromatic amines (only carcinogenic aromatic amines are used as diazo components of azo dyes, not coupling components) and products using these dyes. The carcinogenic problem of aromatic amines was first raised by Germany in 1985, and the carcinogenic effect of aromatic amines was officially confirmed by the German health department in 1905. With the development of dye industry, the cases of bladder cancer are increasing year by year. By the mid-1960s, according to incomplete statistics, more than 1000 cases of occupational bladder cancer caused by aromatic amines were found all over the world, mainly in the dye industry.

1968 held an international conference to analyze the carcinogenicity of aromatic amines, and 1969 was discussed at the 16 international occupational health conference held in Tokyo, Japan. It is agreed that benzidine and diethylamine have the most serious carcinogenic effects on human body. Germany's MAK Committee (Maximum Arbeitplaz Konzentrantions) pointed out that azo dyes made of carcinogenic aromatic amines are prone to biological reduction under the action of intestinal bacteria and some enzymes, which makes the azo dyes crack again, releasing the original carcinogenic aromatic amines and producing carcinogenic activity. Therefore, in the early 1970s, the MAK Committee made suggestions on how to deal with these aromatic amines. German dye industry stopped producing benzidine dyes at 197 1 and replaced benzidine with benzidine derivatives with lower toxicity. Since then, with the deepening of research, many carcinogenic aromatic amines have been discovered. 1973 in may, the us occupational safety and health administration announced that it would take emergency measures against 14 chemicals including benzidine and 3,3'-dichlorobenzidine. 1974 1 10 In October, the US Environmental Protection Agency announced nine kinds of toxic aromatic amines. At that time, the Ministry of Chemical Industry of China also banned the production and use of benzidine, diethylamine and their synthetic azo dyes.

1974, ecology and toxicology association of dye manufacturing industry (ETAD) was established in Europe. The acute toxicity, repeated contact toxicity, sensitization, carcinogenicity, permeability, irritation, toxicity in water and biodegradability of 4400 dyes and organic pigments were systematically tested. It is found that azo dyes synthesized from about 50-60 kinds of aromatic amines can decompose carcinogens, among which 20 kinds of aromatic amines are particularly prominent. 1988 the german MAK Committee emphasized the seriousness of this problem. 1In April, 1992, Germany promulgated the Law on Food and Consumer Goods, which clearly pointed out that 15 azo dyes synthesized by carcinogenic aromatic amines were prohibited dyes, which was the first regulation on the ecological safety of consumer goods in the world. 1July 5, 1994 15 as a formal law, explicitly banned the use of certain azo dyes in textiles and shoes, and later 1994, 12, 14 and1July 5.

According to these rules, Bayer Company analyzed that there were 1 18 kinds of banned dyes involved in the German market in 194, including 77 kinds of direct dyes, 26 kinds of acid dyes, 6 kinds of dispersed dyes, 5 kinds of ice dyes, 3 kinds of basic dyes and 0 kinds of oxidized dyes 1. The company increased the number of banned dyes to 132 by investigating the dyes circulating in 1996 international market. 1999 According to the research of the German Institute of Chemistry and Chemical Engineering (VCI), 14 1 azo dyes can reduce and decompose 22 kinds of carcinogenic aromatic amines, including 8 1 direct dyes, 28 kinds of acid dyes, 8 kinds of disperse dyes, 7 kinds of basic dyes, 5 kinds of ice dyes and 65438+. Between VCI's 14 1 and Bayer's 1 18, there are 1 13 dyes with the same structure and 5 dyes with different structures. Therefore, if the results of the two surveys are added up, there should be 146 banned dyes. In fact, with the addition of auxiliary dyes produced in the process of dye synthesis, the number of banned dyes produced in the process of detection and application exceeds this figure. Some additives may also be suspected to contain 22 kinds of carcinogenic aromatic amines, such as diisocyanates commonly used in polyurethane resin coating agents, such as 2,4-toluene diisocyanate (TDI) and 4,4'-diphenylmethane diisocyanate (MDI), which may contain carcinogenic 2,4-diaminotoluene or 4,4'-diaminodimethylmethane.

The development of green dyes is firstly to develop substitutes for dyes and auxiliaries that are banned due to carcinogenic aromatic amines. Due to the limited value of extractable heavy metals and formaldehyde in textiles, it is necessary to develop metal-free, low-formaldehyde and formaldehyde-free dyes and auxiliaries.

The research and development of green dyes and auxiliaries are actively carried out in the dye and auxiliaries industry in China. In the past ten years, many new varieties that meet the requirements of ecological environment protection have been provided to the market, which basically meet the needs of ecological textiles.