Patent GB-802896-A (GB)
Title: Lubricating grease compositions
IPC: B23K9/18
Filed: 1956-08-13
Abstract: A lubricating grease composition comprises a silicone lubricating oil and an indanthrene compound having a melting point above 250 DEG  F. The lubricating oils mentioned are the organosilicone fluids obtained by the hydrolysis and chemical condensation of compounds having the average formula R4-zSiXz, where R is a monovalent hydrocarbon or halohydrocarbon radical, X is a hydrolysable halogen or alkoxy group and z is a whole or fractional number between 1.5 and 2.25. These compounds are extensively described and examples include halogen-substituted silicones.  Phenylmethyl silicone polymer is preferred.  The indanthrene compounds contain at least two units of the structure <PICT:0802896/III/1> (which may have a second carbonyl radicle attached to the middle ring) the two tricyclic nuclei being linked by two -N=, -NH-, or =CH- groups or by intervening condensed ring systems. Nitrogen, when present, is not a nuclear element in the tricyclic rings.  The carbonyl groups may be, but are preferably not, neutralized with metal ions such as sodium, potassium or calcium. Other gelling agents may be used in conjunction with the indanthrene compounds such as colloids, e.g. silica with or without magnesia or alumina, bentonite and hectorite clays, soaps, e.g. alkali metal soaps of aliphatic monocarboxylic acids of at least 20 carbon atoms, which may be combined with alkali metal salts of aromatic carboxylic acids such as sodium benzoate.  The greases may contain optional ingredients such as anti-oxidants, anti-corrosion agents and extreme pressure additives.  An example comprises a methylphenyl silicone polymer base oil gelled with an aqueous paste of indanthrone and dehydrated.  Specification 3462/46, as open to inspection under Sect. 91, is referred to.ALSO:A lubricating grease composition comprises a silicone lubricating oil and an indanthrene compound having a melting-point above 250 DEG  F.  The lubricating oils mentioned are the organosilicone fluids obtained by the hydrolysis and chemical condensation of compounds having the average formula R4-zSiXz, where R is a monovalent hydrocarbon or halohydrocarbon radical, X is a hydrolysable halogen or alkoxy group and z is a whole or fractional number between 1.5 and 2.25. These compounds are extensively described and examples include halogen-substituted silicones. Phenylmethyl silicone polymer is preferred.  The indanthrene compounds contain at least two units of the structure <FORM:0802896/IV (a)/1> (which may have a second carbonyl radical attached to the middle ring) the two tricyclic nuclei being linked by two -N=, -NH-, or =CH- groups or by intervening condensed ring systems. Nitrogen, when present, is not a nuclear element in the tricyclic rings.  The carbonyl groups may be, but are preferably not, neutralized with metal ions such as sodium, potassium or calcium. Other gelling agents may be used in conjunction with the indanthrene compounds such as colloids, e.g. silica with or without magnesia or alumina, bentonite and hectorite clays, soaps, e.g. alkali metal soaps of aliphatic monocarboxylic acids of at least 20 carbon atoms, which may be combined with alkali metal salts of aromatic carboxylic acids such as sodium benzoate. The greases may contain optional ingredients such as anti-oxidants, anti-corrosion agents and extreme pressure additives.  An example comprises a methylphenyl silicone polymer base oil gelled with an aqueous paste of indanthrone and dehydrated.  Specification 3462/46 , as open to inspection under Sect. 91, is referred to.