Patent GB-766528-A (GB)
Title: A process for the production of organosilicon compounds
IPC: H01B3/46
Filed: 1955-03-30
Abstract: 766,528. Organo-silicon compounds and polymers. MIDLAND SILICONES, Ltd. March 30, 1955 [April 13, 1954], No. 9286/55. Classes 2 (6) and 2 (7). [Also in Group V] Organo-silicon compounds, including polymers, free from aliphatic unsaturation and silicon-bonded hydrogen and containing at least one alkyl radical of less than five carbon atoms attached to silicon, are modified by reaction with an olefinic compound in the presence of an aromatic acyl peroxide. It is suggested that a hydrogen atom is abstracted from the alkyl radical followed by addition of the olefine to the free radical thus produced. The olefine may polymerize under the influence of the peroxide and the. temperature should therefore be kept below that at which such polymerization occurs rapidly. Temperatures of 50-75‹ C. are specified for the more reactive olefinic compounds such as acrylonitrile and 110-150‹ C. for tetranuoroethylene or ethylene. The olefine may be a polymer, e.g. natural rubber or polybutadiene. A large number of organo silicon compounds are referred to, conforming to the general formulµ and R x R<SP>1</SP> y X z Si-(in which the silicon atom is attached to one or more other silicon atoms), in which a is 1-4, b 0 to 3, c 0 to 3, x 1 to 3, y 0-2 and z 0 to 2. R is an alkyl radical of less than 5 carbon atoms, R<SP>1</SP> is any siliconbonded organic radical, free from aliphatic unsaturation, R<SP>11</SP> is any divalent hydrocarbon radical free from aliphatic unsaturation, and X is any hydrolysable or condensable group. A large number of olefinic compounds are referred to. In examples: (1) trifluorochloroethylene was reacted in the presence of,benzoyl peroxide in a rocker bomb at 110-150‹ C. with (a) 1000 c.s. viscosity trimethyl endblocked polydimethylsiloxane; (b) 10 c.s. viscosity trimethyl end-blocked polydimethylsiloxane; (c) a non-flowing polydimethylsiloxane; (d) (Me 2 SiO) 4 ; (e) (Me 3 Si) 2 O; (f) a 320 c.s. viscosity liquid of formula (Me 2 SiCH 2 ) x . The unreacted halogenated ethylene was recovered and the quantity reacted determined. The product from (a) was fractionated giving inter alia a liquid with good lubricating properties. The physical properties of the various fractions and the CF 2 =CFC1 to Si ratios are tabulated. Three of the fractions were further fractionated. (2) Divinylbenzene was reacted with a 1000 c.s. viscosity trimethyl endblocked polydimethylsiloxane. (3) As in (2) but using styrene, the product being fractionated. (4) As in (2) but using vinyl acetate, the product being fractionated. (5) As in (2) but using acrylonitrile, the product being fractionated. (6) A benzene-soluble non-flowing polydimethylsiloxane was reacted with acrylonitrile and the product fractionated. (7) Reacting the polysiloxane of Example (2) with 1-dodecene. (8) Reacting the polysiloxane of Example (2) with acrylamide and fractionating the product. (9) Reacting the polysiloxane of Example (2) with cis-dichloroethylene and fractionating the product. (10) Reacting the polysiloxane of Example (2) with hexafluorodichlorocyclopentene. (11) As in (8) but using (a) allyl alcohol; (b) allylamine, and (c) acrylic acid. (12) Reacting dimethyldiethoxysilane with trifluorochloroethylene, the product being more resistant to hydrolysis than the starting material. (13) Trifluorochloroethylene reacted with diethyldichlorosilane, tetramethylsilane and a resinous phenylmethylpolysilane. The Specification lists a large number of other starting materials including polymeric ethylenically unsaturated compounds such as natural rubber, polybutadiene, polychloroprene, butadienestyrene and butadiene-acrylonitrile copolymers and polyhexafluorobutadiene. The grafting of the olefin and the organosilicon compound may be carried out simultaneously with the polymerization of the olefin. Specification 688,166 is referred to.