Patent GB-757219-A (GB)
Title: Improvements in or relating to lubricating compositions
Inventor: ELLIOTT JOHN SCOTCHFORD
IPC: G04B31/08
Filed: 1953-09-17
Abstract: A lubricating composition comprises a neutral ester or mixture of esters derived from aliphatic or cycloaliphatic dicarboxylic acids having from four to ten carbon atoms in the molecule, and branched-chain aliphatic or alkyl substituted cycloaliphatic alcohols having at least four carbon atoms in the molecule or from mixtures of such alcohols with glycols, and a minor proportion of a di (hydroxyaryl) thioether.  The ester may have the general formula <FORM:0757219/III/1> where R is an aliphatic or cycloaliphatic hydrocarbon radical having 2 to 8 carbon atoms, and R1 and R2 are branched-chain alkyl or alkyl-substituted cycloalkyl radicals having at least 4 carbon atoms; R may be -CH=CH-, (CH2)n where n is 2 to 8, or <FORM:0757219/III/2> The ester may be obtained by esterifying the dicarboxylic acid with a mixture of an alcohol and a glycol, and have the formula R2OOC.R.COOR3OOC.R.COOR1 where R, R1, and R2 are as above and <FORM:0757219/III/3> is a glycol or polyglycol having not more than 12 carbon atoms. The ester may also be obtained by esterifying a dicarboxylic acid with a glycol and a monocarboxylic acid or with a glycol, a monocarboxylic acid and a monohydric alcohol.  Lists of acids and glycols are given; examples of esters are di(1-methyl-4-ethyl octyl) glutarate, di(2-ethyl hexyl) adipate, azelate, sebacate, maleate and pinate, di(3-methyl butyl) azelate, di(3:5:5-trimethyl hexyl) sebacate, adipate and azelate, di(methyl cyclohexyl) adipate, 2-ethyl hexyl 1-methyl heptyl sebacate, 2-ethyl hexyl capryl succinate, and di(2-ethyl butyl) azelate.  The di(hydroxyaryl) thioethers have the general formula <FORM:0757219/III/4> where Ar are aromatic nuclei, x, y and z are 1 to 3 and n is zero or 1 to 6.  Examples are pp1-dihydroxy diphenyl thioether, di(3 methyl - 4 - hydroxyphenyl) thioether, di(5-methyl - 2 - hydroxyphenyl) thioether, di(2-methyl - 4 - hydroxyphenyl) thioether, di(4-methyl - 6 - hydroxyphenyl) thioether, di(6-methyl - 2 - hydroxyphenyl) thioether, di(3:5-dimethyl-2-hydroxyphenyl) thioether di(4-methyl - 3 - tertiary butyl - 2 - hydroxyphenyl) thioether, polymerized di(5-octyl - 2 - hydroxyphenyl) thioether, mixed isomeric bis(dihydroxy tertiary butyl phenyl) thioethers prepared from tertiary butyl catechol, di(3 - methoxy - 4 - hydroxyphenyl) thioether, and mixed isomeric di(o-phenyl hydroxyphenyl) thioethers prepared from o-phenyl phenol.  The thioethers are present in concentrations of 0.05 to 5.0 per cent by weight of the composition.  The composition may also include amines boiling above 140 DEG C., such as n-octylamine and higher primary aliphatic amines, dibutylamine and higher secondary aliphatic amines, cycloaliphatic amines such as dicyclohexylamine, heterocyclic amines such as the lupetidines and higher homologues of piperidine, and basic tertiary amines such as di-n-octylmethylamine and 2:6 lutidine. The amines may be present in amounts of 0.01 to 1.0 per cent. by weight of the composition.  The composition may also include polymers of esters of acrylic or alkyl-substituted acrylic acids, such as polymerized n-butyl, n-hexyl, 3:5:5 trimethyl hexyl and lauryl esters of methacrylic acid.  The polymers may be present in amounts of 1 to 15 per cent. by weight of the composition.  The composition may include rust inhibitors, such as metal petroleum sulphonates, and up to 20 per cent. by weight of the composition of mineral oil. Examples of compositions are given.  Specifications 584,445 and 696,064, mentioned in Provisional Specification are referred to.