Patent GB-757241-A (GB)
Title: Improvements in or relating to lubricating compositions
Inventor: ELLIOTT JOHN SCOTCHFORD
IPC: G04B31/08
Filed: 1954-01-26
Abstract: The invention comprises a lubricating composition as claimed in the parent Specification which lubricating composition has incorporated therein a minor proportion of a neutral organic phosphate or phosphite ester.  The composition of the parent Specification compries 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 dicarboxylic acid ester may have the general formula <FORM:0757241/III/1> where R is a 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:0757241/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:0757241/III/3> is a glycol or polyglycol havng 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, di(3-methyl butyl) azelate, di(2-ethyl hexyl) azelate, di(2-ethyl hexyl) sebacate, di(3 : 5 : 5-trimethylhexyl) sebacate, di(3 : 5 : 5-trimethyl hexyl) adipate di(2-ethyl hexyl) maleate, di(methyl cyclohexyl) adipate, 2-ethyl-hexyl 1-methyl heptyl sebacate, di(2-ethyl hexyl) pinate.  The organic phosphate esters have the formulae <FORM:0757241/III/4> or where R1, R2 and R3 are alkyl, aryl, alkaryl or cycloalkyl radicals, and R4 is an alkylene or arylene radical.  Examples of phosphate esters are trimethyl, triethyl, tri(n-butyl), tri(2-ethyl hexyl), triphenyl, tri-o-tolyl, tri-m-tolyl, tri(p-tertiary amyl phenyl), tri(methyl cyclohexyl) tri(butoxyethyl) phosphates and tetraethyl p-phenylene diphosphate. The phosphate esters are present in amounts of 0.5 to 10 per cent by weight of the composition.  The organic phosphite esters have the formula <FORM:0757241/III/5> where R1, R2 and R3 are alkyl, aryl, alkaryl or cycloalkyl radicals, or they may be phosphite esters of hydroxy-substituted aromatic thioethers and have the formula <FORM:0757241/III/6> or (RO)m-P-(O-Ar-S-Ar-OH)n where the R's are hydrocarbon radicals which may have ether or ester substituents, the Ar's are aromatic radicals which may have alkyl, ether or ester substituents, m is zero, 1 or 2, and n is 1 to 3, the sum of m and n being 3. Examples of phosphite esters are tri(n-butyl), triphenyl, tritolyl, tricyclohexyl, tri(methyl cyclohexyl) phosphites and p-octyl phenyl thioether phosphite, and di(3-carbomethoxy-4-hydroxyphenyl) thioether ditolyl phosphite. The phosphite esters are present in amounts of 0.1 to 5 per cent by weight of the composition.  The di(hydroxyaryl) thioethers have the formula <FORM:0757241/III/7> where Ar's are aromatic nuclei, x, y and z are 1 to 3 and n is zero or 1 to 6.  Examples are p p1-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)thiether, di(6-methyl-2-hydroxyphenyl) thioether di(3 : 5-dimethyl-4-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 from 0.2 to 5.0 per cent by weight of the composition.  The compositions may also include amines boiling above 140 DEG C., in amounts of 0.01 to 1.0 per cent by weight, polymers of esters of acrylic or alkyl-substituted acrylic acids in amounts of 1 to 15 per cent by weight, metal petroleum sulphonates and up to 20 per cent mineral oil.  Examples of compositions are given.  Specifications 574,445 and 696,064 also are referred to.