Can technical grade sodium hexametaphosphate(SHMP) be used as a complexing agent in printing and dyeing?
Editor：川东化工Time：2019-05-09Hits：
Complexing agent in the printing and dyeing industry is also known as chelating agent, chelating dispersant, metal blocking agent, water softener and so on. Sodium hexametaphosphate(SHMP) complexing agent is more and more widely used in printing and dyeing industry, such as softening water quality, preventing sediments, eliminating scaling of dyeing and finishing equipment, preventing bleaching and holes in fabrics, ensuring brightness of dyeing, etc.
Sodium hexametaphosphate(SHMP) complexing agent and metal ions bind to form compounds that have only coordination bond but no covalent bond. Compounds that have both coordination bond and covalent bond are called chelates. The stability constants of complexes are constants of the equilibrium of reversible reactions of complexation and dissociation. The lower the stability constant is, the more metal ions the complex dissociates, and the higher the stability constant is. The less metal ions the complex dissociates, or even does not dissociate. Moreover, the complex will not change its valence in the redox reaction. Complexation capacity (complexation capacity) refers to the amount of metal ions that can be complexed per gram of complexing agent. The higher the complexation capacity, the stronger the complexation ability.
The stability of the complexing agent at different PH values, ie the change in the stability constant at different PH values, is another important property of the complexing agent. The complexing ability of some complexing agents varies greatly at different PH values, and some may even hydrolyze, decompose or react to lose the complexing force.
Different complexing agents have different properties and complexing abilities, so they should be selective when used. Technical grade sodium hexametaphosphate(SHMP) has good complexing power in acidic medium.
The technical grade sodium hexametaphosphate(SHMP) produced by Chongqing Chuandong Chemical (Group) Co., Ltd. is produced from the genuine raw materials obtained by the thermal process of the phosphate rock of our own refined phosphorus mine. It has uniform particles, less impurities, better flow rate and less consumption.
