SOLVENTLESS COMPOSITIONS OF POLYSILOXANES WITH HYDROXYSILYL GROUPS AND RETICULATING AGENTS WITH ALKOXYSILYL GROUPS CATALYZED BY ORGANIC IRON OR ZIRCONIUM COMPOUNDS, THEIR USE IN IMPREGNATING OR COATING COMPOSITIONS FOR ASBEST, CELLULOSIC OR SYNTHETIC MATERIALS

摘要

Solventless organopolysiloxane compositions are well adopted as coating/impregnating materials for a wide variety of substrates to provide, e.g., water repellant/solvent resistant gaskets and various substrates possessing enhanced non-stick characteristics, are comprised of (i) an alpha , omega -dihydroxypolydiorganopolysiloxane having a viscosity, measured at 25 DEG C., ranging from 5 to 100,000 mPa.s and consisting essentially of recurring units of the formula Z2SiO (ii) a polyorganopolysiloxane having from 1.60 to 1.90 organic radicals per silicon atom, having a viscosity ranging from 30 mPa.s at 25 DEG C. to 3,000 mPa.s at 25 DEG C., having from 0.2 to 10% of hydroxyl groups and consisting essentially of the recurring units RSiO1.5, R2SiO and R3SiO0.5 (iii) a crosslinking agent containing a polyalkoxysilyl group; and (iv) a catalytically effective amount of an organic iron or zirconium catalyst soluble in the organopolysiloxane medium.