Patent GB-785198-A (GB)
Title: Improved extreme pressure lubricants
Inventor: MOFFATT VIVIAN ALEXANDER
IPC: C10M131/12
Filed: 1956-04-30
Abstract: Lubricating-oil compositions comprise a lubricating oil or grease and a diester of a b -halo substituted alkane dicarboxylic acid, the carbon chain of which may be interrupted by an oxygen or sulphur atom.  The lubricating oil may be mineral or synthetic or a mixture of oils, a list of synthetic oils being given, and may be gelled to a grease with a metal soap of a fatty acid or an inorganic gelling agent such as silica or clay.  Examples of suitable acids at b b 1dichloro adipic, a a 1 tetrachloro adipic, hexachloro adipic, a a 1b b 1 tetrachloro sebacic and the mono and di b  halogen derivatives of glutaric, 1,2-dimethyl glutaric, 1,2-dimethyl adipic, pimelic, 1,2,5-trimethyl pimelic, suberic, azelaic, nonane-1:9 dicarboxylic and decane-1:10 dicarboxylic acids.  An example of an acid with an interrupted chain is HOOC-(CH2)3-S-(CH2)3-COOH.  Any alcohol may be used to form the ester, monohydric alcohols, particularly alkanols with 6-9 carbon atoms such as hexanol, 3-ethyl hexanol, 2-methyl heptanol and 3,5,5-trimethyl hexanol, being preferred, but aryl substituted alcohols and alcohols containing heterocyclic substituents such as furfuryl alcohol are also mentioned.  In examples the tetra-chloro (a a 1,b b 1) derivative of di (3,5,5 tri methyl hexyl) sebacate and the tetra chloro (a a 1b b 1) derivative of adipic acid dimethyl ester were added to oils and greases. Optional ingredients mentioned are antioxidants such as alkyl phenols, amino phenols and amines, corrosion inhibitors such as dicarboxylic acids containing at least 16 carbon atoms and organic compounds containing acidic radicals in close proximity to a nitrile, nitro or nitroso group, wear-reducing agents such as esters of phosphorus acids and neutral aromatic sulphur compounds of relatively high molecular weight, and anti-foam agents such as dimethyl silicone polymer.  Also mentioned are oil-soluble urea or thio-urea derivatives, polyisobutylenepolymers, and polymerized unsaturated esters of fatty acids and monohydric alcohols.ALSO:Di-esters of b -halo substituted alkane dicarboxylic acids are employed as ingredients in lubricating compositions (see Group III).  They may be prepared by reacting chlorine with an alkane dicarboxylic acid and esterifying the resulting halogenated dicarboxylic acid with a suitable alcohol.  Preferably, the dicarboxylic acid or the corresponding dimethyl ester is first converted into the acid dichloride, e.g. with thionyl chloride, and the acid dichloride then reacted with gaseous chlorine.  The chlorination may be effected in the presence of a catalyst such as iodine.  In examples details are given of the preparation of the tetrachloro (a ,a 1,b ,b 1) derivative of di-(3,5,5-trimethylhexyl) sebacate from 3,5,5-trimethylhexanol and the tetrachlorinated dichloride obtained by chlorinating the reaction product of sebacic acid and thionyl chloride, and of the tetrachloro (a ,a 1,b ,b 1) derivative of adipic acid dimethyl ester from methanol and the tetrachlorinated dichloride obtained by chlorinating the reaction product of adipic acid and thionyl chloride using ultra-violet illumination to catalyse the chlorination.