Tetraethyl tetrafluo ammonium fluoroborate preparation method

Abstract

The present invention relates to the preparation process of tetraethyl ammonium tetrafluoroborate as electronic level reagent in producing electronic elements. The preparation process includes recrystallization to obtain refined boric acid, preparing fluoroboric acid with hydrofluoric acid and boric acid in the equal molar ratio, exchange reaction of tetraethyl ammonium halide and fluoroboric acid at 10-50 deg.c and alcohol in the presence of organic solvent, eliminating hydrogen halide at 30-90 deg.c and reduced pressure condition, recrystallization and low temperature decompression drying to obtain ultimate product tetraethyl ammonium tetrafluoroborate. The ultimate product reaches the quality requirement of: purity not lower than 99.5 %, water content not more than 10 ppm, Fe not more than 1.0 ppm, Si not more than 3.0 ppm, Na not more than 3.0 ppm, and K not more than 3.0 ppm.

Description

technical field [0001] The present invention relates to a kind of preparation method of the electronic grade reagent-tetraethyl ammonium tetrafluoroborate that is used for preparing electronic components, and the molecular formula of tetraethyl ammonium tetrafluoroborate is (C 2 h 5 ) 4 N + BF 4 - . Background technique [0002] product(C 2 h 5 ) 4 N + BF 4 - It can be prepared by reacting quaternary ammonium base or quaternary ammonium salt with fluoboric acid. Many documents have been reported, such as: JP2001-247522A mentions that the use of quaternary ammonium bases can be used as raw materials to react with fluoboric acid to obtain high-purity (C 2 h 5 ) 4 N + BF 4 - . JP2000-226361 report uses quaternary ammonium salt as raw material to carry out (C 2 h 5 ) 4 N + BF 4 - Synthesis. JP2000-226360 then first carries out haloalkane and low-carbon tertiary amine reaction, and then reacts with fluoboric acid to generate final product (C 2 h 5 ) 4 ...

AI Technical Summary

Problems solved by technology

[0003] Looking at the above (C 2 h 5 ) 4 N + BF 4 - Preparation method, the preparation method of quaternary ammonium base as raw material is relatively mild, and the technical process is relatively short, but because the source of quaternary ammonium base is mostly obtained by ion exchange of quaternary ammonium salt, therefore, when using quaternary ammonium base as raw material, It is unavoidable to have some metal ions such as potassium and sodium, to obtain high purity, the target product (C) that does not contain metal ions substantially 2 h 5 ) 4 N + BF 4 - The production process brings many troubles and difficulties

The second method and the third method are actually one method, that is, the preparation method of quaternary ammonium salt as a raw material. The fourth method is not suitable for use because the reaction temperature is relatively high, and the methanol solution of boron trifluoride is highly toxic and belongs to dangerous goods.

Some literature introduces the process of concentration and crystallization and introduces the use of various organic solvents for crystallization and washing, which causes troubles in the recovery of organic solvents