Study On Preparation Of E-grade 2, 3, 4, 4'-Tetrahydroxybenzophenone

Electronic chemicals generally refers to chemicals used in the electronic industry,mainly used in integrated circuits and printed circuit board. Nowadays ,with the rapid development of electronic technology, especially in the field of microelectronic technology, the circuits which was highly integrated required photoresist's machining accuracy in the etching process becoming more and more harsh, Therefore, the quality of chemicals used in electronics, especially the quality of metal ions to a more demanding. 2,3,4,4'-tetrahydroxybenzophenone (4HBP) commonly used as a UV absorber, mainly used for the import agent of UV positive photoresist, are widely used in modern integrated circuit processing.In this paper, 2,3,4,4'-tetrahydroxybenzophenone crude has been synthesized according to reference by pyrogallic acid and p-hydroxybenzoic acid as raw material and boron trifluoride as a catalyst, and the structure have been identified by spectral analysis IR, 1HNMR, 13CNMR and EI-MS, etc. then try to find the optimum conditions of synthesis process by orthogonal test: feed ratio of pyrogallic acid with p-hydroxybenzoic acid is 1:1.1(molar ratio), amount of catalyst 240ml, reaction temperature 110∪?eaction time 8 hour. Under these conditions the average yield can reach to 84%.4HBP's refining includes decolorization and purification, final product meets all the requirement of specifications.(1)Decolorization test Choose the decoloration special activated carbon and D301 resin as decolorant, investigate the impact of the amount and ratio of decolorant, time and temperature on decolorization by single factor test, the best conditions for decolorization: the proportion of carbon to resin is 1:4, and amount of about 3% of crude products, under the temperature of 75℃for 30 minutes.(2)In this research we adopt the combination of chromatographic column and micro-filtration membrane to remove the products of metal ions, according to physical and chemical properties of liquid and the state of metal ions in solution, choice the granular activated carbon which after oxidated-acidificated for column packing; and roll-microporous membrane composited by PTFE, investigate the impact of membrane pore size and pressure on separation, and then effect the metal ions in filtrate, and to determine the optimum process parameters: membrane pore size 0.2μm, pressure 0.06MPa, cycling for 45 minutes in 35~38℃, and then collect the filtrate, cooling and crystallize, filter and dry, get product finally. All the standard of product: purity≥99.5%, the total yield≥76%, metal ions≤200ppb, reached the level of electronic-grade. Test results show that the combination of chromatographic column and micro-filtration membrane complement and promote each other, improve the treatment effect of the entire process.