Sodium Hexametaphosphate is mainly used for dispersing in coatings.
Coatings are widely used in home, construction and industry.
Coatings are usually made of resins, oils or emulsions, with or without addition of pigments and fillers, plus many additives, and viscous liquids made from organic solvents or water.
Additives in the coating can improve the appearance and performance of the coating, such as the brightness, light transmittance, mildew resistance, uniform dispersion, adhesion, etc. Sodium hexametaphosphate is an important coating additive.
The molecular formula of sodium hexametaphosphate is (NaPO3) 6, which belongs to a kind of polyphosphate with indefinite composition. The anion of sodium hexametaphosphate has a high molecular weight, and generally contains 30-90 PO3 genes, forming a long chain.
Due to the addition of water glass and other alkaline substances in the coating, the alkaline environment with pH value of 10-10.5 was prepared, that is, the concentration of OH - ion in the coating is high, and the reaction proceeds to the right, which is conducive to the further decomposition of H3PO4 and the conversion of sodium hexametaphosphate to orthophosphate. And at this time, the phosphate will carry out the condensation of multiple phosphoric ACID functional groups, especially at high temperature, the molecular groups of sodium hexametaphosphate will condense, and the condensed molecular groups are combined with the three-dimensional network of bentonite molecular groups in the coating, which effectively plays the role of bonding.
With the increase of the content of sodium hexametaphosphate, the effect on the brushing property is more obvious. When the content of sodium hexametaphosphate in the coating is about 6%, it can be fully dipped in the coating, and the brushing is light and smooth. After brushing, the coating will flow automatically without leaving any trace, and the viscosity will recover, The dribbling property of the coating with this content is very low, and the coating after brushing can maintain its inherent shape under the action of gravity, reaching the degree of balance with the dribbling property.
