Dyestuff manufacturers introduce environmentally friendly dyes to you (3)
(1) Environmental friendly reactive dyes with high fixation rate are KE, ME and B reactive dyes at home, and Procion H-EXL, Sumifix Supra, Basilen Fm and Cibacron C reactive dyes abroad. The fixation rate of these new reactive dyes is more than 80%. The levelness and diffusivity of these new reactive dyes are very good. They are not affected by bath ratio, temperature and salt content. They have good washability. They have excellent light fastness and perspiration fastness because of a suitable one-time absorption rate.
(2) In the process of reactive dyeing with low salt dyeing, inorganic salts are often used as dyeing promoters in dyeing liquor. The wastewater with high salt content destroys the ecological environment of water and poses a serious threat to crops and human beings. Sumitomo Company of Japan adopts environmental protection dyes such as Sumifix Supra NF and E-XF, with salt consumption of 60% of the general dyes; Cibacron LS dyes of Ciba Company have high affinity for fibers, good dye solubility, high bonding fastness and low salt consumption, only 1/3-1/2 of the general reactive dyes, with dye uptake rate of over 90% and fixation rate. Kayacion E-CM dye, Kayacion E-MS dye, Kayacion E-S133 dye, Levafix EA, Levafix ES, Levafix OS series dyes developed by Japan Chemical Pharmaceutical Company, all have low salt dyeing function, good dye solubility, good leveling, low salt consumption, and are environmentally friendly new products.
(3) Environmentally friendly reactive dyes without heavy metals or adsorbable organic halides, such as Ciba-cron Black CNN, Black W-NN, Black C-2R, Black LS-N and domestic reactive black KN-GZGC133 (granules), are the main types of reactive dyes.
(4) Environmentally friendly reactive dyes with improved fastness are Cibacron Light, Sumifix Supra HF and NF series, Kayacion E-LE and AP dyes for printing. Their perspiration-sunlight fastness reaches 3-4 grades and above.
Commonly used sulfur dyes are not allergic dyes, carcinogenic dyes and acute toxic dyes. They do not contain heavy metals and adsorbable organic halides. They use less salt and consume much less water and energy than reactive dyes. Therefore, sulfur dyes are also one of the alternative dyes for banned dyes, especially black ones. But when dyeing with sulfur dyes, sodium sulfide and alkali need to be added to reduce them. The waste water contains 15%-20% sulfide and the hydrogen sulfide odor produced in the manufacture and application of sulfur dyes brings serious environmental and ecological pollution problems.
Diresul RDT dyestuff produced by Clariant Company in Switzerland is a 20% pre-reduced sulfur dyestuff solution with sulfur content ranging from 0.7% to 4.0% and almost no odor of hydrogen sulfide, which is made by replacing sodium sulfide and alkali with environmentally and ecologically harmless glucose and alkali as reducing agents. Because the new dyes greatly reduce the sulfide content in wastewater, consume less water, and treat the wastewater simply, and use hydrogen peroxide, bromate or persulfate as oxidant when oxidizing, the oxidized wastewater is also easy to treat. Deiresul EV, a new environmental friendly sulfur dye, contains less than 50 mg/L of sulfide and 1/3 of the conventional dosage of reducing agent. The sulfide content in wastewater is greatly reduced, and the COD value of wastewater is also greatly reduced. In addition, the company used sulfite to treat sulfur dye oxides and introduced sulfur sulfide group-SSO3 to make environmental friendly sulfur dyes. Their sulfide content was actually "zero", water-soluble, and the solution was neutral, but they had no affinity for cellulose fibers and were mainly used for leather dyeing.
In addition, James Robinson's pre-reduced leuco solution of sulfur dyes, DyStar's low sulfur content sulfur dyes such as Cassulfon Black C-BRV and Cassulfon Carbon CMRV are environmentally friendly sulfur dyes for environmental and ecological protection.
Vat dyes do not contain azo dyes which can produce 22 carcinogenic aromatic amines under specific conditions. They are not allergic dyes, carcinogenic dyes and acute toxic dyes. They do not contain environmental hormones. Moreover, the color of waste water used is low, and they are a substitute for banned dyes. However, according to the requirements of environmental and ecological protection, there are many steps to manufacture VAT dyes, complex synthesis reactions, and sometimes organic halides such as polychlorinated benzene are used as solvents and heavy metals and their derivatives as catalysts. Therefore, the environmental and ecological pollution of vat dyes has always been a concern.
Indanthren Colloisol dyes of BASF, Cibanone MD dyes of Ciba Refining Company, Benzathren micro dyes of Bezema Company and Mikethrene s/f dyes of Mitsui-BASF Company have all met the requirements of environmental protection dyes.
SM-type vat dye of Shanghai Dyestuff Company not only does not contain prohibited dyes, but also can extract heavy metals below the limit, does not contain environmental hormones, does not contain chemicals polluting the environment, etc. It is also an environmentally friendly vat dye that can replace prohibited dyes.
Cationic dyes are special dyes for polyacrylonitrile fibers. In the production of cationic dyes, zinc chloride is usually used to precipitate the compound salt. The content of zinc in the products is very high, usually 15%-20%. ETAD clearly stipulates that zinc is one of the heavy metals to be controlled in dyes. Therefore, the development of environmentally friendly cationic dyes is mainly about Zinc in dyes. Through technological transformation, the new manufacturing technology no longer uses zinc chloride, but uses other environmentally and ecologically harmless precipitators. The cationic dyes thus prepared meet the requirements of environmentally friendly dyes.