Patent GB-719927-A (GB)
Title: Lubricating greases and the preparation thereof
IPC: C10M169/00
Filed: 1952-12-29
Abstract: A lubricating grease comprises a mineral oil containing less than 15 per cent. by weight of aromatic hydrocarbons and having a viscosity between 1250 and 11000 S.U.S. at 100 DEG F., a liquid polyorganosiloxane having a viscosity of 10-600 centistokes at 100 DEG F. and present in an amount greater than that of the mineral oil, sufficient of a sodium soap of a carboxylic acid having at least 20 carbon atoms in the molecule or of a mixture of soaps consisting predominantly of such sodium soaps to provide a grease consistency, and a minor proportion of a metal salt of a carboxylic acid containing an aromatic ring.  The soap employed may consist wholly of sodium soaps or may contain a minor proportion of soaps derived from other metals such as potassium and calcium.  A list of acids is given from which the soaps employed may be derived, and fatty acids (including beeswax acids, degras acids, and hydroxy fatty acids containing at least 12 carbon atoms in the molecule) and naphthenic acids are mentioned. The metal salt of a carboxylic acid containing an aromatic ring may be an alkali metal, alkaline earth metal or heavy metal salt of such acids as benzoic acid, toluic acids, xylic acids, naphthoic acids, alkyl naphthoic acids, salicyclic acid (and other substituted aromatic acids containing such substituents as halogen, or amino, hydroxy or keto groups), phenyl acetic acid and cinnamic acid.  The lubricating grease may also contain alcohols (including sterols) having at least 12 carbon atoms in the molecule, organic selenium compounds, phospho-sulphurized terpenes, carbamates, pour-point depressants, viscosity index improvers, antioxidants (examples of which are given), anti-corrosion agents and extreme pressure agents.  Additional synthetic lubricating oils such as aliphatic diesters (e.g. bis (2-ethylhexyl) sebacate), phosphate esters (e.g. tricresyl phosphate) and phosphonates (e.g. diethyl benzene phosphonate) may also be present.  In the examples, the mineral oil employed is a bright stock and the polyorganosiloxane is a dimethyl silicone fluid.  Soaps mentioned in the examples are sodium soap of beeswax acids and sodium cerotate, while metal salts of carboxylic acids containing aromatic rings mentioned are sodium benzoate and lithium salicylate.  Additional substance present in lubricating greases of the examples are among the following: wool fat alcohols, cetyl alcohol, cholesterol, phenyl alphanaphthylamine, P2S5 reaction product with turpentine, zinc dibutyl dithiocarbomate and dilauryl selenide.ALSO:A lubricating grease, especially suitable for the lubrication of bearings operating at high temperatures, comprises a mineral oil containing less than 15 per cent. by weight of aromatic hydrocarbons and having a viscosity between 1250 and 11000 S.U.S. at 100 DEG F., a liquid polyorganosiloxane having a viscosity of 10-600 centistokes at 100 DEG F. and present in an amount greater than that of the mineral oil, sufficient of a sodium soap of a carboxylic acid having at least 20 carbon atoms in the molecule or of a mixture of soaps consisting predominantly of such sodium soaps to provide a grease consistency, and a minor proportion of a metal salt of a carboxylic acid containing an aromatic ring.  The soap employed may consist wholly of sodium soaps or may contain a minor proportion of soaps derived from other metals such as potassium and calcium.  A list of acids is given from which the soaps employed may be derived, and fatty acids (including beeswax acids, degras acids, and hydroxy fatty acids containing at least 12 carbon atoms in the molecule) and naphthenic acids are mentioned.  The metal salt of a carboxylic acid containing an aromatic ring may be an alkali metal, alkaline earth metal or heavy metal salt of such acids as benzoic acid, toluic acids, xylic acids, naphtoic acids, alkyl naphthoic acids, salicylic acid (and other substituted aromatic acids containing such substituents as halogen or amino, hydroxy or keto groups) phenyl acetic acid and cinnamic acid.  The lubricating grease may also contain alcohols (including sterols) having at least 12 carbon atoms in the molecule, organic selenium compounds, phospho-sulphurized terpenes, carbamates, pour-point depressants, viscosity index improvers, antioxidants (examples of which are given), anti-corrosion agents and extreme pressure agents. Additional synthetic lubricating oils such as aliphatic diesters (e.g. bis (2-ethylhexyl) sebacate), phosphate esters (e.g. tricresyl phosphate) and phosphonates (e.g. diethyl benzene phosphonate) may be present.  In the examples, the mineral oil employed is a bright stock and the polyorganosiloxane is a dimethyl silicone fluid.  Soaps mentioned in the examples are sodium soap of beeswax acids and sodium cerotate, while metal salts of carboxylic acids containing aromatic rings mentioned are sodium benzoate and lithium salicylate.  Additional substances present in lubricating greases of the examples are among the following:-wool fat alcohols, cetyl alcohol, cholestanol, phenyl alpha-naphthylamine, P2S5 reaction product with turpentine, zinc dibutyl dithiocarbamate and dilauryl selenide.