METHOD OF OBTAINING OLIGOBORSILAZANES Russian patent published in 2017 - IPC C07F5/02 C08G77/62 C08G77/06 C08G79/08 

FIELD: chemistry.

SUBSTANCE: method is proposed for the preparation of oligobosilazanes by the interaction of oligosilazanes containing NH and Si-H groups, which are organosilicon compounds of the silazane class that do not contain alkyl radicals at the nitrogen atom and boron-containing modifiers with BH groups that do not contain alkyl radicals at the nitrogen atom, in a solvent mixture, characterized in that the oligobisilazanes are prepared in two stages, the first of which involves dissolving aminoborane in an N-methylcyclosilazane medium selected from [R¹R²Si-NR³]_n, where R¹=H, R²=Me, H; R³=Me; n=3, 4, at molar ratios of N-methylcyclosilazane to aminoborane from 0.60 to 2.18 and a Si/B ratio of 2.40 to 6.55 at a temperature of 90-120°C for 0.5-2.0 hours to form a boron-containing composition which is an adduct of aminoborane with N-methylcyclosilazane, and in the second stage, the boron-containing composition interacts with an oligosilazane selected from oligoorganosilazanes, organocyclosilazanes and disilazanes in various ratios, by heat treatment in an inert gas atmosphere (nitrogen, argon) at 90-140°C for 3.5-8.0 h. When aminosilane is added to oligosilazane, a preliminary heat treatment of the reaction mixture is carried out at 60-80°C in an ammonia medium.

EFFECT: proposed method is carried out in a controlled mode without the use of high-temperature solvents and allows to obtain oligobosilazanes with improved thermal and oxidative stability.

2 cl, 2 dwg, 2 tbl, 8 ex