METHOD OF PRODUCING HEAT-RESISTANT OLIGOORGANOSILOXANE RESINS Russian patent published in 2012 - IPC C08G77/06 

FIELD: chemistry.

SUBSTANCE: invention relates to the technology of producing oligoorganosiloxane resins used in production of composite materials for different purposes, as a film-forming component of lacquer when producing protective coatings and for modifying organic lacquer and resins. Disclosed is a method of producing heat-resistant oligoorganosiloxane resins of formula [PhSiO_3/2]_a[R_nSiO_1.5]_b[Me₂SiO]_c, where R_n - Me, H, Vin, where n=1; a=0.5-0.97; b=0.03-0.5; c=0-0.47 by polycondensation of products of hydrolysis starting organoalkoxysilanes in an active medium which is an anhydrous carboxylic acid under the effect of a catalyst which is sulphuric acid, characterised by that the mixture of starting organoalkoxysilanes, selected from PhSi(OEt)₃, R_nSi(OEt)_4-n, where R_n=Me, H, Vin, where n=1, first undergoes partial hydrolysis at temperature 70°C, where the catalyst - sulphuric acid - is taken in amount of 0.001-0.09 mol % of the total number of moles of starting organoalkoxysilanes, and to improve elasticity of the obtained product, cyclosiloxane [Me₂SiO]₄ which does not contain chlorine is added to the mixture of starting organoalkoxysilanes.

EFFECT: method enables to obtain resins with high decomposition temperature.

1 cl, 2 tbl, 8 ex