Patent GB-669206-A (GB)
Title: Improvements in and relating to lubricating grease
Filed: 1949-07-13
Abstract: Alkylene glycol and alkylene thioglycol polymers and their mono ester and ether derivatives are employed as stabilizers for certain lubricating grease compositions (see Group III).  The polymers have the formula H-(OCnH2n-O-CmH2m)a-OH where a (n+m) is at least 6 and are prepared by polymerizing, in presence of iodine &c. as catalyst, ethylene, propylene, butylene or isobutylene oxide or by reacting a monohydric alcohol with an alkylene oxide.  The average m.w. of the polymers is from 200-7000.  The esters are prepared by esterifying the polymers with suitable acids especially higher fatty acids, naphthenic acids, sulphonic acids or oxidized tall oil acids.  An example of a lubricating grease comprises 3.7 per cent hydrogenated fish oil acids, 3.7 per cent castor oil acids, 1.0 per cent lithium hydrate solution, 10 per cent paraffin oil 35-40 per cent, Coastal pale oil, 5-15 per cent oxidized Edeleanu extract and 0.1 per cent polyethylene glycol.ALSO:In the manufacture of a lubricating grease composition prepared from a mineral and/or synthetic oil and a minor proportion of a soap, there is added to the composition at any stage of its manufacture, from 1-20 per cent by weight of an oxidized petroleum fraction rich in aromatics, and/or an oxidized nitrogenous fraction and/or an oxidized sulphurous fraction, both the last two of which are derived from a petroleum fraction rich in aromatics.  In a modification the aromatic fraction may be added to the grease composition in which it is then oxidized. The aromatic fractions are preferably obtained by the sulphur dioxide or furfural treatment of a petroleum distillate of S.U.V. about 60 at 210 DEG F. although other solvents are also mentioned and suitable fractions may also be obtained by catalytic conversion of petroleum hydrocarbons.  The fraction may be oxidized before or after addition to the grease, by exposure to the air or blowing air through the fraction.  The fractions may also be oxidized, prior to their addition to the grease, by means of hydrogen peroxide, manganese dioxide, permanganates, chlorates, perchlorates, perborates, chromates or chromic acid.  The soap used to form the grease may be a metal or organic base soap of acids such as fatty acids derived from animal, vegetable, marine and fish oils or synthetic acids or mixtures thereof; various acids including hydrogenated, hydroxy and keto acids are mentioned, and also acids derived from the oxidation of petroleum, and naphthenic, rosin and tall oil acids.  Synthetic lubricating oils referred to are the polymerized olefins, or organic esters such as 2-ethylhexyl sebacate, dioctyl phthalate and trioctyl phosphate, and polymeric tetra-hydrofurans; natural oils such as castor or lard oil may be mixed with the mineral or synthetic lubricating oil.  Optional ingredients of the composition mentioned are stabilizing agents such as alkylene glycol or thioglycol polymers and their mono-ester and ether derivatives; additional soaps or salts; oxidation inhibitors such as various amines and phenols; corrosion inhibitors such as primary amines containing at least 6 carbon atoms and heterocyclic nitrogen compounds; extreme pressure agents such as phosphorous esters, aromatic sulphur and selenium compounds; sulphurized fatty oils or esters; sulphurized long-chain olefins; sulphurized or phosphorized compounds; chlorinated hydrocarbons and chlorinated esters; antiwear agents such as urea or thiourea derivatives; anti-foaming agents, viscosity index improvers, oiliness agents and pour point depressors.  Specific examples of all these compounds are mentioned.