Sequestering Agent Commonly Used in Printing and Dyeing
Time: Click: 1818
Sequestering agent, also known as complexing agents, are organic or inorganic compounds that chelate with heavy metal ions to form stable water-soluble complexes and passivate heavy metal ions. The molecule of the compound contains electron donors that can coordinate and bind with heavy metal ions, so it has a series of special effects, such as softening, descaling, rust protection, stability, and synergism. The common sequestering agent used in printing and dyeing is as follows.
(1)Phosphates: mainly including sodium tripolyphosphate, sodium polyphosphate, sodium hexametaphosphate, sodium pyrophosphate and so on.
Because of its ion exchangeability, this reagent is the first softener used in printing and dyeing industry. Sodium pyrophosphate can form complex ions with iron ions, so it can be used as hydrogen peroxide stabilizer. However, inorganic phosphate is prohibited in some areas.
(2)Aminocarboxylic acid: mainly contains ethylenediaminetetraacetic acid (ED-TA), namely softener B; nitrogen triacetic acid (NTA), namely softener A. In addition, there are diethylenetriamine pentaacetic acid (DTPA), N-hydroxyethyl ethylamine triacetic acid (HEDIA), ethylene glycol monobis (B-aminoethyl ether) - N, N-tetraacetic acid (EGTA).The ligands of aminocarboxylic acid chelating agents are nitrogen atoms and negatively charged carboxylic acid radical ions (COO-). The more ligands, the stronger the complexation with metal ions. Among them, DTPA cooperates most strongly with most metal ions, followed by EDIA and HEDIA, and NTA is the worst. Among them, DTPA is the best hydrogen peroxide stabilizer. However, NTA, EDTA, DTPA, and others have very poor biodegradability due to metal chelation and have been banned in some European countries in recent years.
May 10, 2017Waterborne polyurethane possess good film covering property in itself. If we introduce cationic chain extender at the time of compounding polyurethane, we can get cationic waterborne polyurethanne. T...view
May 10, 2017It will improve the wet fastness of nylon and its blended fabrics after dyeing and printing . It will improve the nylon fabrics color fastness at continuous dyeing . And it have less impact on the gl...view
May 11, 2017I. The choose of dyeThere are a great variety of reactive dye with different quality level. So the choose of qualified dye becomes important.1. The choose of bi-functional reactive dyes and multi-func...view
August 3, 2017People in the printing and dyeing industry know that after the fabrics processed by fixing agent, fixing agent remover is often used to remove the fixing agents remaining on the surface of fabric. Thi...view
December 6, 2019Preface:Environmental acrylic levelling agent BDR is a high-quality retarding agent, which is suitable for the dyeing of acrylic fiber of cationic dyestuff(medium to quickly absorbed).It does not contain benzalkonium chloride limited by 2013 oeko-tex stanview