METHOD OF OLIGO- AND POLYELEMENTOORGANOSPIROCYCLOSILOXANES PREPARATION Russian patent published in 2018 - IPC C08G77/06 C08G77/08 C08G77/16 C08G77/58 

FIELD: chemistry.

SUBSTANCE: invention relates to the synthesis of polyelementoorganospirocyclosiloxanes. Method is proposed for the preparation of heat-cured oligo- and polyelementoorganospirocyclosiloxanes containing homogeneously polycondensation containing from 1.01 to 3.87 % by weight of hydroxyl groups corresponding to the structural formula

,

where M=Si, Ti, Zr; R¹=H, CH₃, C₆H₅; R²=CH₃, CH₂Cl, CF₃CH₂CH₂, CH=CH₂, C₆H₅; a=4–19, acidohydrolytic copolycondensation of one of the four-functional organoelement monomers-tetraalkoxides (source of the Q-unit) of formula M(OR)₄, where R=C_nH_2n+1 (n=1–8), or mixtures thereof with an individual diorganodialkoxysilane (source of the D-unit) of general formula R¹R²Si(OR³)₂, where R³=R, and/or with an individual diorganocyclosiloxane (source of the D-unit) of formula [R¹R²SiO]_m, where m=3, 4, 5, 6, and/or their mixtures under the condition Q:D=1:2. Technical result is a universal method for the preparation of oligo- and polyelementoorganospirocyclosiloxanes with a uniform distribution of Q- and D-units, a degree of polycondensation ≥ 90 %, high stability, reproducibility of their physico-chemical characteristics and yield of at least 98 %, as well as reduced consumption of organic acids, a decrease in the formation of by-products – alcohols and their esters 2.2 times by using diorganocyclosiloxanes as feedstock, acceleration of the technological process and reduction of losses of the target product as a result of replacement of the filtration stage by centrifugation are achieved.

EFFECT: universal method for the preparation of oligo- and polyelementoorganospirocyclosiloxanes has been developed.

1 cl, 11 ex