Method for preparing granular hexamethylol melamine

Abstract

The invention discloses a method for preparing granular hexamethylol melamine, which includes the following steps that: measured water and paraformaldehyde are poured into a reaction kettle, a moderate amount of inorganic base is added to regulate the pH value to 7 to 8, measured melamine is then added after 5 minutes of stirring, and the temperature is then increased to 40 DEG C to 50 DEG C, and is kept for about 15 minutes to 2 hours; a moderate amount of inorganic base is used to regulate the pH value to 8 to 10, and the temperature is then increased to 50 DEG C to 80 DEG C, kept for about 15 minutes to 2 hours and reduced to less than 40 DEG C; acid is used for regulating the pH value to neutral, centrifugal separation is carried out, so that waste water is separated, and after drying, the finished product is obtained; and the separated waste water can be recycled to replace part of water. The invention has the advantages of little pollution and easy operation, moreover, the synthesized hexamethylol melamine is sand-like granules, and can be easily separated and dried, and the hexamethylol melamine has good effect when being used in fields such as the synthesization of glue for rubber, the synthesization of amino resin for baked steel finish and waterproof coating for mineral wool boards.

Description

technical field [0001] The invention belongs to the field of chemical synthesis, in particular to a preparation method of hexamethylolmelamine. Background technique [0002] In the textile dyeing and finishing industry, hexamethylolmelamine is used as a cross-linking agent for pigment printing of textile products, which can effectively improve the color fastness of textile products; as a finishing agent for textile products, it can effectively improve the waterproof, anti-shrinkage, and anti-shrinkage properties of textile products. Anti-wrinkle performance, the finished textile products are crisp, plump and shiny; it is used to synthesize highly methylated amino resins, which are widely used in the coating industry for automobiles and color steel tiles. At present, the general production of hexamethylol melamine is to use melamine and 37% formaldehyde solution to synthesize, that is, formaldehyde solution and melamine are subjected to methylolation reaction under alkaline c...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to overcome the above-mentioned deficiencies existing in the prior art, and provide a kind of preparation method of granular hexamethylol melamine, replace formaldehyde aqueous solution with paraformaldehyde as reaction raw material, add reclaimed waste water to carry out methylolation reaction , aiming to solve the problems in the prior art that there are many aldehyde-containing wastewater and long time consumption, etc. The wet product obtained from the separation has a solid content of more than 75%, and the drying is fast and does not agglomerate