Patent GB-651543-A (GB)
Title: Improvements in and relating to organo-substituted polysiloxanes
IPC: C08G77/00
Filed: 1948-05-19
Abstract: Polysiloxanes are made by reacting, at temperatures in the range 125 DEG  to 350 DEG  C., and in the absence of an aqueous medium, a compound of general formula RnSiX4,n, where R is a monovalent hydrocarbon radical, X is halogen and n is 1, 2 or 3, with an "ether," viz., a compound of general formula R1-CH2-O-CH2-R11 or R-CH2-O-R111 or <FORM:0651543/IV (a)/1> , where R1 and R11 are hydrogen or monovalent hydrocarbon radicals, R111 is a monovalent aromatic hydrocarbon radical and Z is a saturated bivalent radical, viz. an unsubstituted alkylene radical or a bivalent radical of the general formula -O-(CH2O)n-, where n is 1, 2 or 3. Example of "ethers" include dialkyl and aryl alkyl ethers, trioxane, tetrahydrofuran, pentamethylene oxide and heptamethylene oxide.  From 0.1 to 5 per cent by weight of a catalyst such as aluminium or other specified metal chloride and boron halide may be used.  The products of the reaction are organosubstituted polysiloxanes and an organic halide.  The latter, e.g. methyl chloride, may be used, as in Specification 575,667, in the preparation of organohalogenosilanes by passage over heated silicon in the presence of a metal catalyst.  The reactant ratio is preferably that representing about 1.5 to 6 or more halogen atoms of silane to each "ether" oxygen atom.  In examples, dimethyldichlorosilane and dimethyl ether are reacted (1), (2) plus aluminium chloride; (3), (4) alone; (11) plus zinc chloride; (12) plus tin chloride hydrate; (13) plus cobalt chloride hexahydrate; (14) plus nickel chloride hexahydrate; and dimethyldichlorosilane was reacted with (6) diethyl ether; (7) di-n-butyl ether; (8) anisole; (9) tetrahydrofuran-(tetramethylene oxide); (10) trioxane; and (5) trimethylbromosilane was reacted with dimethyl ether plus aluminium chloride.  One of the products of example (8) was C6H5OSi(CH3)2Cl, having a boiling-point of 200 DEG  C.  The 1.4-dichlorobutane obtained in example (9) may be treated with an alkali-metal cyanide to give adiponitrile which may be used in fibre-forming polyamide production.  The polysiloxanes obtained in example (10) include [Cl.Si.(CH3)2]2O and [(CH3)2SiO]4 and [Cl.(CH3)2SiO]2Si(CH3)2.ALSO:Polysiloxanes are made by reacting, at temperatures in the range 125 DEG  to 350 DEG  C., and in the absence of an aqueous medium, a compound of general formula RnSiX4-n, where R is a monovalent hydrocarbon radical, X is halogen and n is 1, 2, or 3 with an "ether," viz. a compound of general formula R1-CH2-O-CH2-R11 or R-CH2-O-R111 or <FORM:0651543/IV (b)/1> where R1 and R11 are hydrogen or monovalent hydrocarbon radicals, R111 is a monovalent aromatic hydrocarbon radical and Z is a saturated bivalent radical, viz., an unsubstituted alkylene radical or a bivalent radical of the general formula -O-(CH2O)n)-, where n is 1, 2 or 3. Examples of "ethers" include dialkyl and aryl alkyl ethers, trioxane, tetrahydrofuran, pentamethylene oxide and heptamethylene oxide.  From 0.1 to 5 per cent by weight of a catalyst such as aluminium or other specified metal chloride and boron halide may be used.  The products of the reaction are organo-substituted polysiloxanes and an organic halide.  The latter, e.g. methyl chloride, may be used, as in Specification 575,667, in the preparation of organohalogensilanes by passage over heated silicon in the presence of a metal catalyst.  The reactant ratio is preferably that representing about 1.5 to 6 or more halogen atoms of silane to each "ether" oxygen atom.  In examples, dimethyldichlorosilane and dimethyl ether are reacted (1), (2) plus aluminium chloride; (3), (4) alone; (11) plus zinc chloride; (12) plus tin chloride hydrate; (13) plus cobalt chloride hexahydrate; (14) plus nickel chloride hexahydrate; and dimethyldichlorosilane was reacted with (6) diethyl ether; (7) di-n-butyl ether; (8) anisole; (9) tetrahydrofuran (tetramethylene oxide); (10) trioxane; and (5) trimethylbromosilane was reacted with dimethyl ether plus aluminium chloride.  One of the products of example (8) was C6H5OSi(CH3)2Cl, having a boiling point of 200 DEG  C.  The 1.4 dichlorobutane obtained in example (9) may be treated with an alkali-metal cyanide to give adiponitrile which may be used in fibre-forming polyamide production.  The polysiloxanes obtained in example (10) include [ClSi(CH3)2]2O and [(CH3)2SiO]4 and [(Cl(CH2)2SiO]2Si(CH3)2.