Patent GB-673734-A (GB)
Title: Improvements in mineral lubricating oil compositions
Filed: 1948-02-05
Abstract: Substances of general formula <FORM:0673734/IV (b)/1> where M is a metal, X is oxygen, sulphur or selenium, X1 is oxygen, sulphur or selenium, X or X1 or both being sulphur or selenium, R and R1 are organic radicles and R1 is aromatic, are employed as additives in lubricating compositions (see Group III).  The use of such substances containing an aliphatic hydrocarbon group having at least 20 carbon atoms linked to the aromatic nucleus is however excluded.  The additives may be prepared by first forming a compound <FORM:0673734/IV (b)/2> where R11 is aromatic and contains a substituent hydroxyl group, and then replacing the hydrogen of the hydroxyl group with a metal.  Compound <FORM:0673734/IV (b)/3> may be prepared by esterifying an acid <FORM:0673734/IV (b)/4> with a material R11XH selected from the class consisting of aromatic alcohols and phenols and their sulphur and selenium analogues, wherein the radicle R11 contains at least one hydroxyl radicle which is attached to an aromatic ring and which does not become esterified. Lists of acids which may be employed in the preparation are given and include aliphatic acids such as fatty acids, cycloaliphatic acids such as naphthenic acids, aromatic acids and any of these acids wherein a sulphur or selenium atom is substituted for at least one atom of oxygen. Lists are also given of phenolic alcohols and polyhydric phenols which may be employed in the preparation, while phenyl thio- or seleno-alcohols, and thio- or seleno-phenols which contain at least one hydroxyl group attached to an aromatic ring, are also mentioned for this purpose.  The additive may contain substituents for example a halogen such as chlorine.  In an example, the magnesium phenate of m-hydroxyphenylthionostearate is prepared by reaction of thiostearic acid chloride with resorcinol and treatment of the product with magnesium methoxide.ALSO:A lubricating composition, particularly suitable for use as a crankcase lubricant when high temperatures or other severe conditions are encountered, comprises a major proportion of mineral oil and a minor proportion of an oil-soluble substance of the general formula <FORM:0673734/III/1> where M is a metal, X is oxygen, sulphur or selenium, X1 is oxygen, sulphur or selenium, X or X1 or both being sulphur or selenium, R and R1 are organic radicles and R1 is aromatic, the substance not being one containing an aliphatic hydrocarbon group having at least 20 carbon atoms linked to the aromatic nucleus.  The substance may be prepared by first forming a compound <FORM:0673734/III/2> where R11 is aromatic and contains a substituent hydroxyl group, and then replacing the hydrogen of the hydroxyl group with a metal.  Compound <FORM:0673734/III/3> may be prepared by esterifying an acid <FORM:0673734/III/4> with a material R11XH selected from the class consisting of aromatic alcohols and phenols and their sulphur and selenium analogues, wherein the radicle R11 contains at least one hydroxyl radicle which is attached to an aromatic ring and which does not become esterified.  Lists of acids which may be employed in the preparation are given and include aliphatic acids such as fatty acids, cycloaliphatic acids such as naphthenic acids, aromatic acids and any of these acids wherein a sulphur or selenium atom is substituted for at least one atom of oxygen. Lists are also given of phenolic alcohols and polyhydric phenols which may be employed in the preparation, while phenyl thio- or seleno-alcohols, and thio- or seleno-phenols which contain at least one hydroxyl radicle attached to an aromatic ring, are also mentioned for this purpose.  The substance added to the mineral oil may contain substituents; thus if it contains a halogen such as chlorine it will impart high detergency and high film strength to the lubricating composition.  The lubricating composition may also contain extreme pressure additives such as sulphur or halogen compounds.  In an example 1.5 per cent of the magnesium phenate of m-hydroxphenyl-thionostearate (prepared by reaction of thiostearic acid chloride with resorcinol and treatment of the product with magnesium methoxide) is added to mineral oil. The Specification as open to inspection under Sect. 91, refers to a lubricating composition comprising a major proportion of mineral lubricating oil and a minor proportion of an oil-solube metal-containing aromatic compound having a molecular structure characterized by an ester group, an aromatic group, and the metal-containing radicle MX-, in which X is selected from the class consisting of oxygen, sulphur and selenium, and is directly attached to an aromatic ring.  The addition of the magnesium phenate of lauryl salicylate to mineral lubricating oil is mentioned.  The details of the preparation of the magnesium phenate of lauryl salicylate and the magnesium phenate of iso-amyl salicylate, the lists of phenolic acids, aliphatic alcohols, aromatic alcohols and monohydric phenols which may be used in the preparation of the oil-soluble metal-containng aromatic compound, and the list of substituents which may be present in such compound, are those which appear in U.S.A. Specification 2,320,228.  This subject-matter does not appear in the Specification as accepted.