Study On The Synthesis Of The Dispersing Agent MF

The dispersing agent MF acquires a considerable degree of developmet, resulting from its performance to other agents, and its over60%of consumption in the dyestuff. Actually, it plays an important role in dispersing and stuffing the dyes.The dispersing agent MF is one kind of anionic dispersing agent, the formaldehyde condensate of methyl naphthalene sulfonic acid. Normally, it is synthesized to be industrial naphthalene, sulphonating by the sulfonic acid and then condensated by the formaldehyde. After neutralizing with the lime and liquid, it can be strained to be the target product. But it also produces too much calcium sulfate waste residue, contributing to the environmental burden.According to the materials and data both from home and abroad, as well as my actual inspection. In this article,I choose SO3as the sulfonating agent to sulfonate it, and the formaldehyde to condensate it, which successfully demonstrate the reasonable synthetic route and process of the dispersing agent MF. It turns out that all the data of this item has reached the standard of the same kinds of products in China.The optimized process of the dispersing agent MF is as follows:In a flask,100g of methyInaphthalene was added, then20g of sulfuric acid and45g of sulfur trioxide was added at50-80℃. The mixture was heated to140℃for3hours. After cooling to120℃,30g water was added for hydrolysis, until the sulfonated acid value reaches about21%. Afterwards,50g formaldehyde was added at80℃. Then the mixture was heated to100-110℃for4hours. After the condensation reation finished, a certain amount of water was added, controlling the solid content at40%. The pH is adjusted to5-7with liquid caustic soda, the residue is slurry dispersing agent MF. It can also be spray dried to obtain a dispersant MF powder.The dispersing agent MF’s total yield rate of small scale experiment is1:2.0, while the rate of pilot scale experiment is1:1.98, a little lower than the former. So it meets the designing purpose.