Methyl Naphthalene Sulphonate Formaldehyde

The preparation process of Sodium Salt Of Polynaphthalene Sulphonic Acid mainly includes three steps: Sulfonation of methyl naphthalene, condensation of sulfonated products with formaldehyde, and neutralization.
Firstly, 500kg of methyl naphthalene is put into the sulfonation kettle, heated and melted, then the stirring is turned on, and the temperature is raised to 130~140℃ for reaction. Then, add 210L of water under rapid stirring, and then stir for half an hour to take samples to measure the acidity, if the total acidity of 25% to 27% is qualified. Cool to 90～100℃.
Then, condense the sulfonation product with formaldehyde. The above cooled material was pumped into the condensation kettle, 37% formaldehyde aqueous solution was added, and the reaction was carried out under the pressure of 196 kPa.
Finally, the neutralization step was carried out. Add alkali to neutralize to pH 8-10, and the reaction was finished. Cool the crystallization, filter out the crude product and dry it as the finished product.
Sodium polynaphthalene sulfonate has excellent diffusion properties, non-permeability and foaming, acid resistance, alkali resistance, hard water resistance and inorganic salts. It has no affinity for cotton, hemp and other fibers, and can be used with protein and nylon at the same time, but it can not be mixed with cationic dyestuff or cationic surfactant. It is mainly used as dispersant and filler for reducing dyes and disperse dyes. It has the advantages of good abrasion effect, dispersion, heat resistance and high temperature dispersion stability.