ORGANOSILICON COMPOUNDS

摘要

1473335 Silicon-containing Ti and Al chelates; RTV compositions IMPERIAL CHEMICAL INDUSTRIES Ltd 8 Sept 1975 [19 Sept 1974] 40881/74 Headings C3S and C3T Novel chelates have the formula AlRR1 2 or TiRR1(OR11) 2 , where R represents a siliconcontaining group chelated to the metal atom, R1 represents an optionally silicon-containing group chelated to the metal atom, and R11 is a hydrocarbyl or trialkylsilyl group. They may be prepared by addition of a compound containing at least one SiH group to an unsaturated chelating agent before or after reaction thereof with a suitable Al or Ti compound. In Examples 1 and 2 (EtO) 2 MeSiH is added to ethyl 2-allylacetylacetate (Example 1) or 3-allyl-acetylacetone (Example 2) in 1 : 1 molar ratio i.p.c. PtCl 2 2Et 2 S to give the silylated chelating agents; these are then reacted alone in 2 : 1 molar ratio with (i-PrO) 4 Ti (Examples 1 and 2), (i-PrO) 2 Ti(OSiMe 3 ) 2 (Example 6) or (i-PrO) 3 Ti- OSiMe 3 (Example 7), or followed by the unmodified ethyl acetoacetate or acetylacetone in 1 : 1 : 1 molar ratio with (iPrO) 4 Ti (Examples 4 and 5); the ester is reacted in 3 : 1 molar ratio with (iPrO) 3 Al; or the silylated diketone with unmodified acetylacetone and (iPrO) 3 Al in 2 : 1 : 1 molar ratio. In Example 3 the siloxane Me 3 SiO(Me 2 SiO) 35À5 (MeHSiO) 12À5 SiMe 3 is added i.p.o. PtCl 2 .2Et 2 S to the product from (iPrO) 4 Ti, allylacetylacetone and acetylacetone in 1 : 1 : 1 molar ratio; this is used to prime Al or as an additive for an RTV silicone rubber composition. In Examples 10 and 11 allylacetylacetone is reacted with alum to give the Al trichelate, to which is then added 2 molar parts of (EtO) 2 Me- SiH or (MeOC 2 H 4 O) 2 MeSiH. In Examples 12-20 6 p.b.w. of various of the above products and 0À4 p.b.w. of stannous octoate are used to catalyse 100 p.b.w. of a base consisting of 40 wt. per cent CaCO 3 and 60 wt. per cent of (A) a 3 : 2 : 1 mixture of polydimethylsiloxane diols of viscosity 4700 and 60,000 cP/25‹ C. and a trimethylsilyl - terminated polydimethylsiloxane of 350 cP/25‹ C., or (B) a product from a polydimethylsiloxane diol of 3900 cP/25‹ C. and methylsilyl triacetate, giving RTV rubbers.