Patent GB-911171-A (GB)
Title: Calcium-containing carbonate organic sulphonate complexes
IPC: C10M159/24
Filed: 1958-12-31
Abstract: Lubricating oil compositions comprise, as an anti-wear and detergent additive, a minor proportion by weight of a complete calcium containing organic sulphonate-carbonate salt, which may also contain a second metal from Group I or II of the Periodic Table, in a hydrocarbon solution, prepared in specified manner by reacting a preformed slurry or suspension of carbonated calcium hydroxide in methanol with a hydrocarbon solution of an organic sulphonic acid or normal or basic metal salt thereof, the metal being from Group I or II of the Periodic Table, removing the methanol and filtering the resulting solution of complex salt (see Group IV(b)).  The composition normally contains 0,5 to 40% by weight of complex salt solution.  Specific complexes are calcium wax-benzene sulphonate-carbonate, calcium sodium wax benzene sulphonate-carbonate, calcium zinc wax-benzene sulphonate-carbonate. Analogous oilsoluble petroleum sulphonate-carbonates are mentioned. Tests are described with reference to a Mid-Continent oil to which various of the above salts are added in paraffinic oil solution.  The slurry or suspension of carbonated calcium hydroxide in methanol mentioned above is prepared by forming a suspension or slurry of calcium hydroxide in absolute methanol containing 200 to 800 mls. of methanol per equivalent of calcium hydroxide, chilling the mixture if necessary to a temperature of 30 DEG C. or lower and passing CO2 thereinto at 30 DEG C. or lower to provide therein a molar ratio of CO2:Ca of from about 0,6 p  to about 2,0.  Specification 790,473 is referred to.ALSO:Calcium-containing complex organic sulphonate carbonate salts, which may also contain a second metal from Group I or II of the Periodic System are prepared by a process comprising the steps of (i) forming a suspension or slurry of calcium hydroxide in absolute methanol containing 200 to 800 mls. of methanol per equivalent of calcium hydroxide, (ii) chilling the suspension, if necessary, to a temperature of 30 DEG C. or lower, (iii) passing CO2 into the suspension or slurry at a temperature of 30 DEG C. or lower to provide therein a molar ratio of CO2:Ca of from about 0.6 to about 2.0, (iv) forming a reaction mixture of the carbonated suspension or slurry at 30 DEG C. or lower with a hydrocarbon solution of an organic sulphonic acid or normal or basic metal salt thereof, the metal being of Group I or II, in a proportion to supply to the mixture at least about 2 equivalents of Ca per equivalent of sulphonic acid or at least 1 equivalent of Ca per equivalent of sulphonic acid metal salt, and allowing the mixture to react, (v) removing the methanol from the reaction mixture and (vi) filtering the reaction mixture to recover a hydrocarbon solution of the calcium-containing complex salt.  The sulphonic acids specified include oil-soluble petroleum sulphonic acids and various alkyl substituted benzene and naphthalene sulphonic acids containing C8-28 alkyl groups, the preparation of a petroleum sulphonic acid and wax-benzene sulphonic acids being described in detail.  The hydrocarbon solvent may be for example a mineral oil, benzene, toluene, xylene, or light naphtha.  The complex salt products may be used as lubricating oil additives (see Group III).  In typical examples: (4) CO2 is passed into a slurry of calcium hydroxide in chilled methanol and a hot solution of a wax-benzene sulphonic acid in a paraffinic oil is added thereto; methanol is distilled off and nitrogen then passed through at 90-100 DEG C. to remove residual methanol whereupon the product is filtered; (6) and (7) the method of (4) is repeated in substance using however the normal calcium salt or the sodium salt of the sulphonic acid as starting material.  Other examples describe the analogous preparations of a complex calcium-zinc sulphonate-carbonate and a complex calcium-barium sulphonate-carbonate (starting with a barium wax-benzene sulphonate whose preparation is described). Comparative experiments are described wherein (a) a mixture of an alkyl benzene sulphonic acid, methanol, calcium hydroxide and paraffin oil is carbonated at 20 DEG C., heated to remove the methanol and then filtered; (b) the method of (4) is carried out but the preformed slurry of calcium carbonate is heated under reflux forming a gel, before being reacted with the sulphonic acid.  Specification 790,473 is referred to.