Patent GB-644359-A (GB)
Title: Stabilised organic liquids of lubricating viscosity and allied substances
Filed: 1946-10-22
Abstract: The Specification as open to inspection under Sect. 91 refers to the addition to synthetic resins, such as polyvinyl resins, of anti-oxidant selenium or tellurium compounds of the general formula [(R1R2R3)­C-X-]nY, wherein R1, R2 and R3 are hydrogen or organic radicals (any two of which may be joined to form a single bivalent radical), C is a carbon atom not forming part of a benzenoid ring, X is selenium or tellurium, Y is hydrogen as a cationic atom or radical and n represents the valency of Y.  Examples given of such compounds include n-butyl, n-amyl, decyl, lauryl and octadecyl seleno-mercaptans and their sodium, calcium, barium, zinc, cobalt, nickel and lead salts.  This subject-matter does not appear in the Specification as accepted.ALSO:Selenium and tellurium derivatives of the general formula [(R1R2R3)=C-X-]nY, wherein R1, R2 and R3 are hydrogen or organic radicals (any two of which may be joined to form a single bi-valent radical), C is an aliphatic carbon atom (i.e. a carbon atom other than a carbon atom forming part of a benzenoid ring), X is selenium or tellurium, Y is hydrogen or a salt-forming cationic atom or radical and n represents the valency of Y, are prepared as follows: Sodium diselenide is reacted with an aliphatic chloride to yield an aliphatic diselenide which is reduced to an aliphatic selenomercaptan.  Potassium or other metal may be substituted for sodium, tellurium may be used instead of selenium and bromine may be substituted for chlorine.  In a specific example dioctadecyl diselenide is prepared by reacting sodium diselenide with octadecyl chloride in the presence of boiling ethyl alcohol, and the dioctadecyl diselenide is extracted with petroleum ether after diluting the reaction mixture with water.  The extract is dried, concentrated and cooled after addition of acetone and the diselenide crystallized out.  The diselenide is then reduced by heating with sulphuric acid and zinc dust, and octadecyl selenomercaptan crystallized out by cooling.  The mercaptan may be converted into metallic salts by reacting it with alcoholic solutions of metal hydroxides or metal acetates or it may be dissolved in aqueous or aqueous-alcoholic sodium or potassium hydroxide and treated with an aqueous solution of a water-soluble polyvalent metal salt to precipitate the mercaptide of the polyvalent metal.  In an example, octadecyl selenomercaptan is converted into the zinc salt by the addition of an aqueous solution of zinc acetate to an alcoholic solution of the mercaptan.  The precipitated mercaptide is filtered, washed successively with water, alcohol and petroleum ether and dried in vacuo over calcium chloride.  Examples are given of the preparation of the cadmium, lead, barium and nickel mercaptides by similar methods.  The selenium and tellurium compounds, and particularly their salts may be used as lubricant antioxidants (see Group III).  The Specification as open to inspection under Sect. 91 describes the use of the compounds defined above as antioxidants for organic substances in general, mention being made of aldehydes, ethers, p  terpenes, mercaptans, phenols and phenol-formaldehyde and urea-formaldehyde resins.  This subject-matter does not appear in the Specification as accepted.ALSO:Organic liquids of lubricating viscosity and allied substances are stabilized against oxidation by incorporating in them a small proportion of a compound having the general formula [(R1R2R3)­C-X-]nY, wherein R1, R2 and R3 are hydrogen or organic radicals (any two of which may be joined to form a single bivalent radical), C is an aliphatic carbon atom (i.e. a carbon atom other than a carbon atom forming part of a benzenoid ring), X is selenium or tellurium, Y is hydrogen or a salt-forming cationic atom or radical and n represents the valency of Y.  The organic liquids of lubricating viscosity may be hydrocarbon motor, gear or turbine oils, or a propylene oxide polymer synthetic oil, and the allied substances may be transformer oils, mineral oil-soap lubricating greases, fats and fatty oils.  The anti-oxidant may be an aliphatic selenomercaptan containing 5 to 30 carbon atoms in the molecule, such as octadecyl or 2-ethylhexyl selenomercaptan or a polyvalent metal salt thereof, e.g. the zinc salt, the proportion of the mercaptan (or its salt) in the composition being about 0.1 to 2 per cent by weight.  The composition may comprise a major proportion of a mineral lubricating oil and dissolved therein about 0.1 to 2 per cent by weight of a polyvalent metal salt of an alkyl selenomercaptan containing 5 to 30 carbon atoms in the molecule and about 0.1 to 2 per cent by weight of an oil-soluble polyvalent metal salt of either a phenol or a sulphonic acid.  The phenate may be an alkaline earth metal salt of an alkylated phenol containing in the molecule two phenate nuclei linked by sulphur. The seleno or telluro additive may be in the form of an concentrated dispersion in mineral lubricating oil for blending with organic liquids of lubricating viscosity, i.e. a minimum viscosity of 40 S.S.U. at 100 DEG  F.  Additional examples of selenium and tellurium compounds which may be used are n-butyl, n-amyl, decyl, lauryl, cetyl, and paraffin wax derived selenomercaptans and their sodium, calcium, barium and zinc salts; 2-ethylhexyl, lauryl and octadecyl telluromercaptan, and their sodium, barium and zinc salts. Other radicals which may be present are ethyl, n- and isopropyl, isobutyl, isoamyl, hexyl, undecyl, and tetradecyl, benzyl and cetylbenzyl, cyclohexyl and methylcyclohexyl, and the organic radical attached to selenium may contain an unsaturated group or may be substituted by a non-hydrocarbon substituent such as chlorine, hydroxyl, alkoxyl, or amino.  Examples of other metals which may be present in the selenium and tellurium compounds are potassium, lithium, strontium, cadmium, cobalt, nickel, lead and thallium.  In an example, lead octadecyl selenomercaptide prepared from basic lead acetate, sodium diselenide and octadecyl chloride (see Group IV (b)) and sulphurized calcium phenate (prepared by condensing a butene polymer of average mol. wt. about 200 with phenol, forming the calcium salt and heating it with sulphur) are dissolved in a solvent refined S.A.E. 30 paraffinic oil of Californian origin in such proportions as to give the oil a content of calcium and zinc each of 7 millimols. per kilogram of oil.  U.S.A. Specifications 2,228,661, 2,346,156, 2,349,817, 2,360,302 and 2,363,012 are referred to.  The Specification as open to inspection under Sect. 91 comprises also compositions in which the major constituent may be any organic substance, specific references being made to gasoline, kerosine, fats and fatty oils.  This subject-matter does not appear in the Specification as accepted.ALSO:The Specification as open to inspection under Sect. 91 refers to the addition to rubber of anti-oxidant selenium or tellurium compounds of the structure [(R1R2R3)­C-X-]nY wherein R1, R2 and R3 are hydrogen or organic radicals (any two of which may be joined to form a single bivalent radical), C is an aliphatic carbon atom (i.e. a carbon atom other than a carbon atom forming part of a benzenoid ring), X is selenium or tellurium, Y is hydrogen or a salt-forming cationic atom or radical and n represents the valency of Y.  Examples given of such compounds include aliphatic selenomercaptans containing 5-30 carbon atoms in the molecule such as n-butyl, n-amyl, decyl, lauryl and octadecyl seleno-mercaptans and their sodium, calcium, barium, zinc, cadmium, cobalt, nickel and lead salts.  This subject-matter does not appear in the Specification as accepted.