Process for preparing polysulfane silanes

• Main Authors: Droege, Helmut, Boldt, Kai Dieter, Hermeke, Julia
• Format: Patent
• Language: English
• Published: 11.07.2023
• Subjects: ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAININGELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN,SULFUR, SELENIUM OR TELLURIUM; CHEMISTRY; METALLURGY; ORGANIC CHEMISTRY

Process for preparing polysulfane silanes of the formula I(R1O)3-mR2mSi-R3-Sx-R3-SiR2m(OR1)3-m  I,by reaction of silane of the formula II(R1O)3-mR2mSi-R3-Hal  II,with one or more metal sulfides of the formula IIIMe(SH)f and/or Me3-fSx-y  III,optionally in the presence of one or more salts of monohydric or polyhydric acids,with the optional addition of y mol of sulfur in aqueous R1-OH solution, wherein the water content of the aqueous R1-OH solution is 5% to 40% by weight,whereina. the process stream from the reaction of silane of the formula II with one or more metal sulfides of the formula III, optionally in the presence of one or more salts and optionally with the addition of sulfur, in aqueous R1-OH solution, comprising polysulfane silanes of the formula I, silane of the formula II, metal sulfides of the formula III, solvent R1-OH, water and process salts,is combined with the wash solution from step d, comprising solvent R1-OH, water and polysulfane silanes of the formula I,b. the solvent R1-OH and water are removed by distillation,c. the remaining suspension comprising polysulfane silane of the formula I and process salt is subjected to a filtration or a sedimentation andd. the process salt from step c is washed with solvent R1-OH and then dried, the wash solution comprising solvent R1-OH, water and polysulfane silane of the formula I is recycled to process step a.