Patent GB-628878-A (GB)
Title: Lubricating compositions comprising carbon black and organo-silicon oxide polymers
Filed: 1946-07-15
Abstract: A method of forming a lubricating composition adapted to the lubrication of ball and roller bearings comprises admixing and dispersing a substantially neutral finely divided carbon black in a normally liquid substantially non-volatile organo-silicon oxide polymer to form a substance of grease-like consistency which contains between 2 and 25 per cent by weight of the carbon black. The polymers may be of viscosity between 3 and 1000 centistokes and their organic substituents may be alkyl, alicyclic, aryl, or aralkyl radicles.  The polymers may be prepared by hydrolysis of organosilanes containing one or more of the hydrocarbon radicals attached to the silicon atom, the remaining substituents being hydrolysable groups.  Hydrolysis is carried out by heating with dilute mineral acid, e.g. a mixture of diethoxy dimethyl silane and ethoxy trimethyl silane and the less volatile products and water are removed under vacuum at 250 DEG  C. A suitable carbon black has a surface area of 134-178 square meters per gram and particle size of 250 Angstron units, and yields a water-extract of pH 9.5 to 5.5.  The ingredients may be blended by passing them through a three-roll paint dispersion mill, followed by heating to 110 DEG  C. In examples, carbon black is blended with (1) an organo-silicon oxide polymer having 95 mole. per cent (CH3)2SiO units and 5 mole. per cent (CH3)3SiO0,5 units; (2) an organo silicon oxide polymer having 40 mole. per cent C6H5.CH3SiO units, 49 mole per cent of (CH3)2SiO units, and 11 mole. per cent of (CH3)3SiO0,5 units. Substances inhibiting corrosion may be added to the products. Specification 600,634 is referred to.  Reference has been directed by the Comptroller to Specification 607,695.ALSO:A method of forming a lubricating composition adapted to the lubrication of ball and roller bearings, comprises admixing and dispersing a substantially neutral finely-divided carbon black in a normally liquid substantially non-volatile organo-silicon oxide polymer to form a grease which contains between 2 and 25 per cent by weight of the carbon black. The polymers may be of viscosity between 3 and 1000 centistokes and their organic substituents may be alkyl, alicyclic, aryl or aralkyl radicles.  The polymers may be prepared by hydrolysis of organosilanes containing one or more of the hydrocarbon radicals attached to the silicon atom, the remaining substituents being hydrolysable groups.  Hydrolysis is carried out by heating with dilute mineral acid, e.g. a mixture of diethoxy dimethyl silane and ethoxy trimethyl silane, and the less volatile products and water are then removed under vacuum at 250 DEG  C.  A suitable carbon black has a surface area of 134-178 square meters per gram, and particle size 250 Angstrom units, and yields a water-extract of pH 9.5 to 5.5.  The ingredients may be blended by passing them through a three roll paint dispersion mill, followed by heating to 110 DEG  C.  In examples, carbon black is blended with (1) an organo-silicon oxide polymer having 95 mole. per cent (CH3)2SiO units and 5 mole. per cent (CH3)3SiO0,5 units; (2) an organo silicon oxide polymer having 40 mole. per cent C6H5.CH3.SiO units, 49 mole. per cent of (CH3)2SiO units, and 11 mole. per cent of (CH3)3,SiO0,5 units.  Substances inhibiting corrosion may be added to the products.  Specification 600,634 is referred to.  Reference has been directed by the Comptroller to Specification 607,695.