Patent GB-705524-A (GB)
Title: Improvements in or relating to lubricating greases
IPC: C10M169/00
Filed: 1951-10-30
Abstract: N-acyl amino phenols of the formula <FORM:0705524/IV (b)/1> wherein R is an alkyl group containing 4-22 carbon atoms and R1 and R2 are hydrogen atoms or alkyl groups containing 1-20 carbon atoms, are employed as thickeners in lubricating grease compositions (see Group III).  N-stearoyl p-amino phenol is prepared by refluxing p-amino phenol with stearic acid in presence of xylene as water-entraining agent, distilling off the xylene and recrystallizing from glacial acetic acid.  Other compounds of the above formula may be obtained by heating the appropriate aminophenol with the desired acid or acid chloride.ALSO:A lubricating grease composition, suitable for use in textile machinery for lubricating twister rings and also suitable for lubricating gears and for forming rust preventive coatings on metal surfaces, comprises a lubricant base thickened with a minor proportion of an N-acyl compound of the general formula <FORM:0705524/III/1> wherein R is an alkyl group containing 4-22 carbon atoms and R1 and R2 are hydrogen atoms or alkyl groups containing 1-20 carbon atoms.  The lubricant base is chosen from mineral lubricating oils, petrolatums, asphalts, asphalts cut back with mineral oils, silicone oils, synthetic dicarboxylic acid esters, polyethers, complex esters and propane-extracted petroleum resins. Silicone oils mentioned are polymers of methyl phenyl, ethyl butyl, methyl cyclohexyl, dicyclohexyl, diphenyl, phenyl ethyl and phenyl propyl silicones.  The synthetic dicarboxylic acid esters may have the general formula R1OOCRCOOR11 wherein R is a bivalent aliphatic hydrocarbon radicle such as methylene, polymethylene, ethylidene, propylidene, methyl dimethylene and butylidene, and R1 and R11 are similar or dissimilar branched chain alkyl, alkaryl and cycloalkaryl radicles having 4-22 carbon atoms, particularly esters of adipic, suberic, azelaic and sebacic acids.  The polyethers may be polyglycol ethers while the complex esters may be esters of alkylated succinic acid or "Oxo alcohol" esters of dihydroxy acids.  The asphalt may be extracted from mineral oil and may be oxidized before use.  Specific N-acyl compounds of the general formula mentioned above are N-palmitoyl, N-stearoyl and N-arachidoyl p-amino phenols, N-n-valeroyl-4-amino-3-pentadecyl phenol, N-n-pentanoyl-4-amino-2, 6-di-tertiary butyl phenol and N-n-hexoyl-4-amino-2-hexyl phenol. The grease composition may also contain a minor proportion of a greaseforming soap, particularly a calcium, barium, strontium, sodium or lithium soap derived from hydrogenated fish oil acids, hydrogenated castor oil, stearic acid, hydroxy stearic acid, oleic acid, beef fat, tallow or other saturated or unsaturated glycerides. In the examples, grease compositions are prepared from (1) mineral lubricating oil and N-stearoyl or N-erucyl p-amino phenol or an N-acyl p-amino phenol wherein the acyl radicle is that of hydrogenated fish oil fatty acids having carbon chain lengths of C14 to C22, (2) phenyl methyl silicone polymer oil and N-stearoyl p-amino phenol with or without a solution of lithium stearate in mineral oil or volatile solvent, the volatile solvent if used being distilled off, (3) white petrolatum and N-stearoyl p-amino phenol, a mixture of N-stearoyl and N-lauroyl p-amino phenols, or N-acyl p-amino phenol where the acyl radicle is derived from a commercial stearic acid containing palmitic acid, (4) mineral oil, di-2-ethyl hexyl sebacate, lithium stearate and N-stearoyl-p-amino phenol, (5) mineral oil, "C8 Oxo" alcohol ester of sebacic acid, lithium 12-hydroxy stearate and N-palmitoyl p-amino phenol, (6) cut back oxidized asphalt and N-stearoyl p-amino phenol prepared from commercial stearic acid, and (7) N-stearoyl p-amino phenol and either petroleum resin, a blend of petroleum resin and mineral oil or a blend of asphalt cut back and petrolatum.ALSO:A lubricating grease composition comprises an asphalt, or an asphalt cutback, thickened with a minor proportion of an N-acyl compound of the formula <FORM:0705524/V/1> wherein R is an alkyl group containing 4 - 22 carbon atoms and R1 and R2 are hydrogen atoms or alkyl groups containing 1-20 carbon atoms.  The asphalt may be extracted from mineral oil and may be oxidized before use. Specific N-acyl compounds mentioned are N-palmitoyl, N-stearoyl and N-arachidoyl p-amino phenols, N-n - valeroyl - 4 - amino - 3 - pentadecyl phenol, N-n-pentanoyl-4-amino-2, 6-di-tertiary butyl phenol and N-n-hexoyl-4-amino-2-hexyl phenol.  The grease composition may also contain a minor proportion of a grease-forming soap, particularly a calcium, barium, strontium, sodium or lithium soap derived from hydrogenated fish oil acids, hydrogenated castor oil, stearic acid, hydroxy stearic acid, oleic acid, beef fat, tallow or other saturated or unsaturated glycerides.  In the examples, grease compositions are prepared from (1) cutback oxidized asphalt and N-stearoyl p-amino phenol prepared from a commercial stearic acid containing palmitic acid and (2) asphalt cutback petrolatum and N-stearoyl p-amion phenol.