Seek the process route for tetramethylammonium hydroxide

What a mature product! Everyone who knows how to work with the Mo production process makes a living from this! Research it on your own; come with solid evidence! Study on the Synthetic Process Conditions of Tetramethylammonium Hydroxide 【Author】: Zeng Qingyun 【Introduction】: With the continuous development of large-scale integrated circuits, there is an increasing demand for high-purity electronic-grade tetramethylammonium hydroxide (TMAH). However, traditional methods for producing TMAH have drawbacks such as high costs and high levels of impurity ions. By comprehensively comparing the literature, this paper selected dimethyl carbonate and trimethylamine methanol solution as raw materials to prepare high-purity TMAH through synthesis, hydrolysis, and electrolysis. Through single-factor experiments and orthogonal experiments, the effects of raw material ratios (molar ratio of dimethyl carbonate to trimethylamine), reaction temperature, reaction time, and reaction pressure on the conversion rate of the synthesis reaction were discussed. The optimal process conditions were determined as follows: the raw material ratio is 1:1.2, the temperature is 125°C, the reaction time is 5.5 hours, the reaction pressure is 2 MPa, and the conversion rate reaches 99.06%. Through single-factor experiments, the hydrolysis process conditions for methyl tetramethylammonium carbonate were investigated: with a molar ratio of water to methyl tetramethylammonium carbonate of 6:1, vacuum distillation was carried out at 70°C for 2 hours, achieving a conversion rate of 94.4%. Titanium-based ruthenium dioxide was used as the anode, and stainless steel was used as the cathode; tetramethylammonium hydroxide was synthesized by electrolysis at a constant current density in an H-type electrolyzer. The effects of the type of ion exchange membrane, raw material concentration, electrolysis temperature, and current density on current efficiency were primarily investigated. When Asahi Kasei F4403D was used as the cation exchange membrane, a current efficiency of 83.5% could be achieved at a concentration of 1.41 mol/L for tetramethylammonium bicarbonate, an electrolyte temperature of 40–60°C, and a current density of 792 A/m2. Infrared spectroscopy and nuclear magnetic resonance spectroscopy were employed to characterize tetramethylammonium bicarbonate and the resulting product, tetramethylammonium hydroxide. I 【Degree Year】: 2010 【Keywords】: Tetramethylammonium hydroxide, Tetramethylammonium bicarbonate, Carbonate ester, Electrolysis, Synthesis 【Degree-awarding Institution】: Zhengzhou University. The electronic-grade tetramethylammonium hydroxide production technology developed by Hangzhou Greenda Chemical Co., Ltd. and Zhejiang University utilizes an environmentally friendly carbonate electrolysis method; the tetramethylammonium carbonate electrolyte is obtained through condensation and hydrolysis reactions of trimethylamine and dimethyl carbonate. The electrolyte raw materials not only cause minimal corrosion to the electrolysis equipment, but the products obtained through electrolysis also contain no chloride ions, thereby improving the purity and quality of the products. The highest yield of the synthesis reaction is 90–95%. Compared with the ammonium chloride electrolysis method, it offers advantages such as a longer service life for the electrolysis system, as well as a lower content of harmful chloride ions in the product. Through measures such as raw material refinement and the use of imported ion exchange membranes, this technology enables the electrolytic product TMAH to meet the enterprise standard Q/GLD205-2004 requirement of less than 50 ppb for metal ions. Under optimized electrolysis conditions, a current efficiency of 80–85% can be achieved, and the specially developed titanium-iridium anode has a service life of over six months. This technology possesses strong competitiveness compared to similar foreign products in terms of raw material costs and production expenses. This technology has been successfully applied at a pilot-scale production level of 600 tons per year; the product quality has received positive feedback from users, offering broad market prospects. In 2005, industrial-scale production with an annual output of over 5,000 tons was successfully launched, yielding significant economic and social benefits.