GB769496A - Organosilicon compounds - Google Patents

Abstract

The invention comprises silanes and siloxanes derived therefrom, the silanes having the general formula [(R11OOC)aR]R1bSiX3-b where R11 is an alkyl radical, R is a divalent or trivalent saturated aliphatic or cycloaliphatic hydrocarbon radical of at least 3 carbon atoms, R1 is a monovalent hydrocarbon radical free from aliphatic unsaturation, or a halogenated derivative thereof, X is Cl, Br or H, a is 1 or 2, and b is 0 or 1, the carbonyl group being at least as far away from the Si atom as the gamma carbon. They are prepared by reacting, at a temperature below 200 DEG C., a silane R1bSiX4-b, at least one X being a hydrogen atom, with an unsaturated, aliphatic or cycloaliphatic mono- or di-ester in which the unsaturated linkage is at least as far from the ester radical as the gamma carbon. Examples of reactants are given, as well as of the radicals R, R1 and R11. Included among those of R1 are chloro-, bromo- and fluoro-substituted radicals. The siloxanes have the general formula [(YOOC)aR]R1bSiO 3-b/2 where Y is an alkyl radical or a hydrogen atom and R, R1, a and b have the above values. When siloxanes containing ester groups are required, the hydrolysis of the above silanes is effected at temperatures below 35 DEG C. To obtain carboxylic acid substited siloxanes, stronger hydrolysis is necessary to hydrolyse the R11 group as well as the X group in the silane, e.g. refluxing with aqueous alcoholic alkaline solution. The siloxanes may be copolymerized with siloxanes including those containing functional groups as disclosed in Specifications 769,497 and 769,498. They may also be reacted with polyfunctional organic compounds such as polyhydric alcohols, polyamines, polycarboxylic acids and their esters, e.g. producing modified alkyd resins, which may be further modified by drying oils or drying oil acids. The siloxanes, per se, are useful as lubricants. In the examples: (1) methyl oleate is heated with phenylsilane in the presence of tert. butyl perbenzoate to give C6H5SiH2C17\t H34COOMe. Hydrolysis at room temperature, with dilute NaOH gives the siloxane [C6H5 (MeOOC.C17H34)SiO]x. Hydrolysis by refluxing with aqueous ethanol NaOH gives the siloxane [C6H5(HOOC.C17H34)SiO]x; (2 Methyl-11-(phenylsilyl)-undecanoate is prepared from methyl undecenylate and phenylsilane and is hydrolysed to [C6H5(HOOC.C10H20)SiO]x; (3) Mixed isomers of the formula C6H5SiH2(C6H20COOMe) are prepared from methyl-4-cyclohexene carboxylate and phenylsilane and are hydrolysed to [C6H5(MeOOC.C6H20)SiO]x; (4) The silane of Example (3) is completely hydrolysed to give the acid-substituted siloxane; (5) Methyl-4-cyclohexene carboxylate is heated with trichlorosilane in the presence of platinum, giving the silane Cl3SiC6H20COOMe which is hydrolysed to [MeOOC.C6H20.SiO1.5]x; (6) A siloxane [C6H5(HOOC.C6H20)SiO]x is heated with a siloxane of the formula [C6H5.HO(CH2)3SiOx] and with 12-hydroxy-stearic acid to an elastic material. Reaction of this product with toluene di-isocyanate produces a rubbery material; (7) A mixture of siloxanes [C6H5(CH3OOC(CH2)3)SiO]x and [C6H5(HOOC.C6H26)SiO]x is heated with a few drops of tert. butylamine and piperidine to form a viscous resin which is further reacted with a small amount of maleic acid to give a resin soluble in acrylontrile; (8) The silane <FORM:0769496/IV(a)/1> is obtained from dimethyl-3,6-endo-ethylene-1,2,3,6 - tetrahydrophthalate and methyl dibromosilane. Mild hydrolysis gives the estersubstituted siloxane which on further hydrolysis yields the acid siloxane; (9) Chlorophenylsilane is reacted with methyl undecenylate to give (ClC6H4)H2Si(CH2)20COOMe. On treatment with cold dil.NaOH, the siloxane[(ClC6H4) MeOOCH(CH2)20SiO]x is obtained, which on stronger hydrolysis yields the acid siloxane; (10) Copolymeric siloxanes of the units C6H5 Me.SiO, Me2SiO and MeOOC.C6H20SiO1.5 are obtained by cohydrolysing an equimolar mixture of Cl3SiC6H20COOMe, C6H5.MeSiCl2 and Me2SiCl2. The copolymer is further hydrolysed to convert the ester group into the acid group. Copolymers are likewise obtained from mixtures of Cl3C6H20COOMe, phenylvinyldichlorosilane, trimethylchlorosilane and tribromoxenyltrichlorosilane; (11) The reaction product of MeSiHBr2 and methyl-4-cyclohexene carboxylate is hydrolysed to (MeOOC.C6H20)MeSiO and finally to (HOOC.C-H20)MeSiO.