method for preparation of nitrogen containing gesub - stitueerde silanen, method for preparation of vulcaniserende polysiloxanrubbers at room temperature under atmospheric conditions.and articles manufactured by vulcanisatie of the so obtained rubbers.

摘要

1297543 Imidatosilanes; RTV polysiloxane compositions GENERAL ELECTRIC CO 3 March 1970 [14 March 1969] 10200/70 Headings C3S and C3T Imidato silanes useful in the preparation of room temperature vulcanizing (RTV) compositions have the general formula where RSP1/SP and RSP7/SP are H or C 1-18 hydrocarbyl, halohydrocarbyl or cyanoalkyl groups, R, RSP2/SP and RSP3/SP are C 1-18 hydrocarbyl radicals which may be halo-, nitro- or alkoxy-substituted and RSP3/SP may additionally be H, dialkylamino or RSP4/SPOC(O)CH 2 - where RSP4/SP is aliphatic hydrocarbyl, or halo- or nitro-hydrocarbyl or RSP5/SPRSP6/SPN- where RSP5/SP and RSP6/SP are aliphatic hydrocarbyl, a is 1 to 4, b is 0 to 3, d and e are 0 or 1 and a + b + d + e is 4. They are prepared by reacting a silane RSP1/SP d RSP7/SP e SiX f , where X is halogen and f is 2, 3 or 4, with an imidate or mixture of imidate and an alcohol. An acid acceptor may be present and the reaction is preferably effected in an organic medium. The R.T.V. compositions comprise an imidatosilane of the above formula, wherein d and/or e are zero, and a silanol chain-stopped polydiorganosiloxane in which the organo groups are C 1-18 hydrocarbyl, halohydrocarbyl or cyanoalkyl. Copolymers and mixtures are included and up to 1% of mono- and tri-organo siloxane units may be present. Exposure to moisture hydrolyses the imidatosilane and cures the mixture. Preferably, 1 to 4 moles of imidatosilane are used per mol. of Si-bonded OH groups in the siloxane. Imidatosilanes of the above formula wherein both d and e and 1 are useful as chain extenders for the silanol-stopped polysiloxanes. In Example 56, a mixture of two silanol-stopped polydimethyl-siloxanes of different viscosities is mixed with dimethyl-bis-(ethylacetimidato) silane, dibutyl tin dilaurate, a silazane-treated silica filler and plasticizer and a small amount of methyl-tris-(ethylacetimidato) silane is added as curing agent. The composition is applied from a caulking cartridge.