Rhone-poulenc Chimie

Veronique Gouron

Bernard Jousseaume

Michel Pereyre

Jean-Marc Frances

Jean-Marie Frances

Novel tetracoordinated tin (IV) compounds, well suited as latent catalysts for the preparation of polyurethanes or for the crosslinking of curable diorganopolysiloxanes (upon thermal decomposition thereof into diorganotin dicarboxylates or dialcoholates), have the general formula (1): ##STR1## in which the radicals R, which may be the same or different, are each a linear or branched chain C.sub.1 -C.sub.20 alkyl radical, a mononuclear aryl radical, or an aralkyl or alkaryl radical, the alkyl moieties of which having from 1 to 6 carbon atoms; the radicals R.sub.1 and R.sub.2, which may be the same or different, are each a hydrogen atom, a cyano radical, a C.sub.1 -C.sub.6 alkyl radical, or an alkoxycarbonyl radical, the alkyl moiety of which having from 1 to 6 carbon atoms, with the proviso that R.sub.1 and R.sub.2 may together form a saturated hydrocarbon ring member having from 5 to 8 carbon atoms; the radical R.sub.3 is a hydrogen atom, a linear or branched chain C.sub.1 -C.sub.20 alkyl radical, a linear or branched chain C.sub.1 -C.sub.20 alkoxy radical, a mononuclear aryl radical or a mononuclear aryloxy radical; and a is 0 or 1.

Tin (IV) compounds

Optionally chelated tetracoordinated or pentacoordinated tin(IV) compounds having the general formula: ##STR1## are useful latent catalysts in compositions for the preparation of polyurethanes, or for the crosslinking of organopolysiloxanes, by increasing the temperature of appropriate reaction mixtures to a level above the decomposition temperature of such tin(IV) compound.

Optionally chelated tin(IV) compounds useful as latent catalysts

Novel tin (IV) compounds

Storage-stable, curable polyorganosiloxane compositions, whether solvent-free, in solution in an organic solvent or in aqueous emulsion, contain (A) a polydiorganosiloxane having silanol endgroups, (B) a polydiorganohydrosilane, and (C) a catalytically effective amount of a latent tin catalyst of the formula (1): ##STR1## and are cured into elastomeric state by heating to a temperature at least equal to the decomposition temperature of the latent catalyst (C); such polyorganosioxane compositions are well adopted for the thin-layer coating of a wide variety of useful substrates, e.g., paper.

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Talence, France

Veronique Gouron