GB622311A - Improvements in or relating to lubricating compositions - Google Patents

Abstract

An extreme pressure or high film strength lubricant comprises a mineral lubricating oil or a lubricating grease and a small proportion, e.g. about 1 per cent of an additive comprising a product obtainable by the addition reaction of a carbon tetrahalide or a trihalomethane and an alkene-1 containing 8 or more carbon atoms in the molecule or a mixture of such alkenes. The carbon tetrahalide may be carbon tetrachloride and the trihalomethane may be chloroform. The product may be partially dehydrohalogenated, e.g. by heating to about 100 DEG C., prior to being added to the oil in order to obtain a more stable product. The addition products before partial dehydrohalogenation are believed to be compounds or mixtures of compounds having the general formula <FORM:0622311/III/1> wherein Y represents a halogen atom, X represents a hydrogen or halogen atom and R represents an aliphatic hydrocarbon radical of at least six carbon atoms. The alkenes-1 used as starting material may be isolated from the mixture of alkenes-1, other alkenes, alkanes and other aliphatic hydrocarbons obtained by the cracking of paraffin wax or the crude complex of cracked hydrocarbons may be used. The addition products may be prepared in the presence of peroxide condensing agents such as benzoyl peroxide or acetyl peroxide. Examples are given of the preparation of the addition products from cracked wax alkenes-1 containing 12 or 14 carbon atoms in the molecule and carbon tetrachloride, chloroform, carbon tetrabromide and bromotrichloromethane respectively [see Group IV (b)].ALSO:Halogen-containing organic compounds, suitable for use as additives in lubricants (see Group III), are obtained by the addition reaction of a carbon tetrahalide or a trihalomethane and an alkene-1 containing 8 or more carbon atoms in the molecule, in the presence of peroxide condensing agents such as benzoyl peroxide or acetyl peroxide. The products are believed to be compounds or mixtures of compounds having the general formula <FORM:0622311/IV (b)/1> wherein Y represents a halogen atom, X represents a hydrogen or halogen atom and R represents an aliphatic hydrocarbon radical of at least six carbon atoms. In some cases the addition product tends to lose hydrogen halide on being subjected to an elevated temperature, but may be stabilized by a partial dehydrohalogenation, for example by heating to about 100 DEG C. In an example, 30 parts by weight of commercial benzoyl peroxide are dehydrated in a Dean and Stark apparatus by refluxing with 770 parts of carbon tetrachloride. 168 parts by weight of a mixture of alkenes-1 containing on an average 12 carbon atoms in the molecule and obtained by the cracking of paraffin wax are added and the mixture refluxed for 17 hours. The excess of carbon tetrachloride is then distilled off, the residue dissolved in 200 parts by volume of acetone and extracted successively with a concentrated aqueous solution of potassium iodide, an aqueous solution of sodium thiosulphate and water. The residual acetone was distilled off, leaving the product in the form of a mobile reddish oil miscible with mineral lubricating oils at room temperature and containing 44 per cent by weight of chlorine. On heating the product to constant weight at 100 DEG C. under 12 m.m. mercury pressure, the chlorine content fell to 23.0 per cent. Additional examples are given of the preparation by similar methods of addiion products from cracked paraffin wax alkenes-1 containing 12 or 14 carbon atoms in the molecule and chloroform, carbon tetrabromide and bromotrichloromethane respectively.