Patent GB-676712-A (GB)
Title: Sulphur-containing compounds and lubricating compositions containing them
IPC: C07B45/00
Filed: 1950-01-13
Abstract: Sulphur-containing compounds suitable for use as additives for lubricants are obtained by heating a mono-alkene containing at least 5 carbon atoms in the molecule or a mixture of such mono-alkenes with sulphur at between 100 DEG  and 200 DEG  C., preferably between 140 DEG  and 180 DEG  C., in the presence of a catalytic proportion of an organic vulcanizing accelerator, the molecular proportion of sulphur to mono-alkene or mixture of mono-alkenes being not more than 2 : 1. In calculating the molecular proportion of sulphur the sulphur molecule is deemed to be monoatomic.  Specified alkenes are pentenes, hexenes, heptenes, octenes, decenes, tetradecenes, cetene, cerotene and melene or mixtures thereof, also the mixture of mono-alkenes obtained by the cracking or by the chlorination and dehydrochlorination of mineral oils or paraffin wax or by the dehydration of long-chain fatty alcohols.  The reaction may be carried out under pressure and in an oxygen-free atmosphere, e.g. nitrogen.  Specified vulcanization accelerators are 1-mercaptobenzthiazole and its substituted derivatives, benzthiazyl sulphides, alkyl xanthates, dithiocarbamates, aryl esters of the dithio acids such as 2,4-dinitrophenyl-piperidine carbothionolate and 2,4-dinitrophenyl-dialkyl dithiocarbamates and esters of the thiazoles with organic acids such as 1-benzthiazyl thiostearate or benzoate and 2,4 - dinitrophenyl - benzthiazyl sulphide.  The more simple types may also be employed, e.g. aniline and thiocarbanilide and other organic bases such as piperidine, hexamethylene tetramine and the guanidines such as diphenylguanidine.  Metal - containing vulcanizing accelerators such as the zinc dialkyl dithiocarbamates cannot be used where the presence of metal would prove undesirable in the final product unless some suitable means of removing the metal is employed.  The use of about 0.5 to 10 per cent of vulcanization accelerator based on the total weight of sulphur and hydrocarbons gives good results.  The reaction products may be purified by distillation under vacuum or by steam distillation under vacuum.  In examples: (1) a mixture of mono-alkenes containing 6 carbon atoms in the molecule (obtained by the fractional distillation of cracked paraffin wax products) are heated with sulphur and 1-mercapto-benzthiazole in an autoclave at 140 DEG  C. for 16 hours; the product is stated to be free from sulphides other than the tetrasulphide, whereas if the accelerator is omitted the product would contain penta- and hexa-sulphides; (2) a mixture of mono-alkenes containing 9 carbon atoms in the molecule (obtained by the fractional distillation of products obtained by the cracking of paraffin wax) is heated with sulphur and zinc diethyl dithiocarbamate at 142 DEG  C. and atmospheric pressure for 10 hours, the reaction mixture being then cooled and filtered to remove the zinc in the vulcanizing accelerator; (3) a mixture of mono-alkenes containing 18 to 20 carbon atoms (obtained by the fractional distillation of a product obtained by cracking paraffin wax) is heated with sulphur and 1-mercapto-benzthiazole at 140 DEG  C. for 9 hours.  Specification 607,765 is referred to.ALSO:A lubricating composition comprises a mineral lubricating oil or a lubricating grease and a small proportion of a sulphur-containing compound obtained by heating a mono-alkene containing at least 5 carbon atoms in the molecule or a mixture of such mono-alkenes with sulphur at between 100 DEG C and 200 DEG C in the presence of a catalytic proportion of an organic vulcanizing accelerator, the molecular proportion of sulphur to mono-alkene or mixture of mono-alkenes being not more than 2:1 (see Group IV(b)). The sulphurated hydrocarbons may be added in such quantities as to yield lubricants having sulphur contents of 0.01 per cent to 5.0 per cent, generally about 0.1 per cent.  The lubricating compositions may contain pourpoint depressors such as alkylated napthalenes, thickeners such as soaps and inorganic gels, oxidation inhibitors such as 2,4-dimethyl-6-tertiary butyl phenol and 2.6-di-tertiary butyl-4-methyl phenol, sludge dispersers such as oil soluble metal soaps and oil soluble metal phenates, anti-corrosion agents such as polycarboxylic acids obtained by condensing alkenes with maleic acid, viscosity index improvers such as polyisobutylenes and methyl methacrylate polymers, foam preventing agents such as polymeric organic silicones and metasilicates and antiring sticking agents such as basic metal soaps of alkylated salicylic acids.  Other extreme pressure additives such as halogen and phosphorus containing compounds may also be used in conjunction with the sulphurated compounds, e.g. such compounds as chlorinated paraffin wax, calcium dichlorostearate, tricresyl phosphate, trichlorophenyl phosphate or 2,4-di(trichloromethyl)-6-nitro-1,3-benzodioxane.