METHOD OF PRODUCING POLYSILOXANE URETHANE Russian patent published in 2012 - IPC C08G18/61 C08G77/458 C08G77/46 C08G18/32 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing polysiloxane urethane, which can be used as film vapour- and gas-permeable polymer materials and protective coatings on fabric. The disclosed method is realised by reacting a low-molecular weight diol, organosiloxane and an aromatic diisocyanate in the medium of an aprotic solvent. The low-molecular weight diol used is an ethylene oxide- and propylene oxide-based block copolymer with molecular weight of 4000-4500 and content of terminal hydroxyl groups of 80-99 wt % and potassium (sodium) alcoholate groups of 1-20 wt %. The organosiloxane used is cyclotetrasiloxane of formula: , where R is -CH₃, -C₂H₅, -C₆H₅, -CH=CH₂. The molar ratio of the ethylene oxide- and propylene oxide-based block copolymer, aromatic diisocyanate and cyclotetrasiloxane is equal to 1:(10-30):(3-40), respectively.

EFFECT: simple process of producing polysiloxane urethane, as well as obtaining polysiloxane urethane with high ultimate tensile stress, modulus of elasticity and vapour permeability, a porous structure, gas permeability and heat-resistance.

19 ex, 1 tbl, 2 dwg