Air activated organotin catalysts for silicone curing and polyurethane preparation
作者:Bernard Jousseaume、Nicolas Noiret、Michel Pereyre、Annie Saux、Jean Marc Frances
DOI:10.1021/om00015a042
日期:1994.3
Upon exposure to air, 1,2-bis(acyloxy)tetraalkyldistannanes incorporated in mixtures of either silicone oils and curing agent, or of isocyanates and alcohols, are oxidized to 1,3-bis(acyloxy)tetraalkyldistannoxanes which show excellent catalytic properties for curing silicones or for preparing polyurethanes. Under nitrogen, they induce longer pot-lives than the usual bis(acyloxy)dialkylstannane catalysts. Peralkyl-polycyclostannanes, obtained either by the palladium-catalyzed decomposition of dialkylstannanes or by reduction of dichlorodialkylstannanes with metals, are also very good latent catalysts for silicone curing. When incorporated into reactive mixtures under nitrogen, they do not catalyze the condensation. Upon exposure to air, they are oxidized to active catalysts which cure silicones. These di- or polystannanes can be considered air-activated latent organotin catalysts.