Production technology of methyl naphthalenesulfonic acid-methyl aldehyde condensation compound

Abstract

The present invention provides a method for preparing a condensation compound of methylol naphthalene sulphonic acid formaldehyde. The method comprises the following steps that methylnaphthalene is adopted as the material, and is sulfonated with 104.5 percent of fuming sulfuric acid in advance; the sulfonated product is condensed with formaldehyde; and, finally the pH is adjusted to between 6 and 9 by liquid alkali, and thus the methylol naphthalene sulphonic acid formaldehyde condensation compound is obtained. The method does not need to add an azeotrope former, and does not need to add and distill of sulfonated bodies every time. The process is simplified, the manufacturing cost is saved, and the impurity content in the product is reduced. Additionally, the 104.5 percent of fuming acid is adopted to sulfonate. Not only the efficiency of methylnaphthalene sulfuration is improved, but also the total acidity of the condensation reaction process is reduced. The subsequent process completely adopts liquid alkali. No calcium sulfate calcium offscum is produced. Compared with the adoption of concentrated sulfuric acid, the quality of the product is equivalent in dispersancy, calcium and magnesium ions are not produced, and the product is stable in heat resistance.

Description

(1) Technical field [0001] The invention relates to a production process of a dye diffusing agent MF (methylnaphthalenesulfonic acid formaldehyde condensate). (2) Background technology [0002] MF is a formaldehyde condensate of methylnaphthalenesulfonic acid, an anionic surfactant, mainly used as a dispersant and filler for disperse dyes and vat dyes. It has the advantages of good grinding effect, dispersibility, heat resistance, and high temperature dispersion stability. It can be compounded with various dispersants to meet the commercial requirements of various disperse dyes and vat dyes. In addition, it can also be used as a superplasticizer for concrete and a dispersant for vat dye suspension dyeing. [0003] Although the current domestic MF production processes are various, they are similar. Basically, methylnaphthalene (with or without pretreatment) is used as the main raw material, sulfuric acid with a concentration of 98% is used as the sulfonating agent, and high-...

AI Technical Summary

Problems solved by technology

The disadvantages of this method are: it is necessary to add an entrainer, and finally there is an additional process of distilling the entrainer; it is necessary to reserve and add recycled materials every time; there is no closed facility in the whole reaction process, and there will be sulfur-containing waste gas during the reaction Escaping not only causes the loss of raw materials, but also seriously pollutes the working environment