Study On Synthesis Of Water-soluble Photoinitiator QTX

Water-soluble light-curing technology is an environmental friendly green technology, It has the advantages of no solution, no stimulation, low energy consumption, fast curing and so on. With environmental regulations increasingly stringent and increased awareness of environmental protection, light-curing technology has been getting more and more attention. Photoinitiator, as an important part of light-curing system, was developed rapidly. In this paper, the research and development on photoinitiator at home and abroad was reviewed, the new directions of photoinitiator wad introduced, especially in the development of water-soluble photoinitiator.In this paper, 2-hydroxy-3,4-dimethylthioxanthone was synthesized by thiosalicylic acid and 2, 3-dimethylphenol as raw material, sulfuric acid as the reaction medium. The product QTX was synthesized by etherification reaction, 3-chloro -2-hydroxypropyl trimethyl ammonium chloride as the etherification agent. The factors of affect the yield of 2-hydroxy-3,4-dimethylthioxanthone and etherification reaction were studied.Appropriate reaction conditions were received by studying the factors which affect the yield: thiosalicylic acid /2, 3-dimethylphenol is 1:4; molar ratio of concentrated sulfuric acid and thiosalicylic acid is 2.17:1; low and high temperature reaction time (1+3) h; low reaction temperature is 10℃, high reaction temperature is 90℃; the maximum yield of 2-hydroxy-3,4-dimethylthioxanthone is 75%. The degree of the factors affect the yield: material molar ratio> quantitative of concentrated sulfuric acid >reaction time>reaction temperature.Appropriate reaction conditions of etherification reaction: reaction time is 18h; reaction temperature is 100℃; the system pH is 9; CHPTA/2-hydroxy-3, 4-dimethyl thioxanthone is 1.1:1. Quaternary ammonium salt can also be phase transfer catalyst, when it is a little excessive, the yield increased significantly. The maximum yield of QTX is 28.5%.In summary, synthesis of 2-hydroxy-3,4-dimethyl thioxanthone and etherification reaction was studied, final yield of QTX was 21.4%...