Preparation method of diazo photosensitizer

Abstract

The invention discloses a preparation method of a diazonium photosensitizer, which comprises the following steps: 1) mixing concentrated sulfuric acid and phosphoric acid according to a proper ratio to obtain a mixed acid, cooling, and slowly adding a proper amount of p-aminodiphenylamine diazonium sulfate (VRT) which is a wet product; wherein the temperature is controlled to be 20-40 DEG C when the p-aminodiphenylamine diazonium sulfate is added; 2) slowly adding a proper amount of paraformaldehyde after the dissolution in the step 1) is finished, and reacting at the temperature of below 40 DEG C until the reaction is complete; 3) dissolving a reaction solution completely reacted in the step 2) in water, adding a proper amount of a chlorine salt, and separating out a yellow precipitate; and 4) filtering, and drying the yellow precipitate to obtain the product. According to the preparation method disclosed by the invention, reaction with paraformaldehyde is carried out in the mixed acid, the reaction temperature can be effectively increased, the direct damage effect of the concentrated sulfuric acid on the raw materials is reduced, the reaction can be carried out at a relatively high temperature which is easier to control, the weight of the synthesized photosensitizer required for photoresist mixing is reduced to 90%, and the cost is saved.

Description

Technical field: [0001] The invention relates to the technical field of polymer material synthesis, in particular to a simple and stable preparation method of a diazo photosensitizer. Background technique: [0002] As people's awareness of environmental protection continues to increase, it has become an inevitable trend for product replacement to replace heavy chrome photosensitive glue with diazo photosensitive glue. In the current market, most of the photosensitizers of flat screen photosensitive adhesives that are commonly used are diazo photosensitizers, and the synthesis of the photosensitizers is mostly using VRT aqueous solution to first synthesize diazo double salts. The dried diazonium double salts are mixed with paraformaldehyde in concentrated sulfuric acid at 15 ℃ below the reaction, washed with ethanol to obtain the available diazo photosensitizer. The process is cumbersome, the cycle of preparing the photosensitizer is long, and the preparation process needs t...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to address the above-mentioned deficiencies in the prior art technology, and provide a kind of simple and stable synthesis and preparation method of diazo photosensitizer, which effectively solves the long cycle of preparing photosensitizer, and the preparation process needs to be cooled down, The obtained photosensitizer has poor quality and other problems