Patent ID: 6015778
Filing Date: 2000-01-18
Classification: C07G,C10M

Abstract:
A process for producing an overbased oil soluble calcium sulfonate, comprising the steps of:(a) mixing a substrate comprising a sulfonic acid wherein the sulfonic acid is of the formulae(R.sup.1).sub.x (R.sup.2).sub.y --T--(SO.sub.3 H).sub.z or (I)(R.sup.2).sub.y --T--(SO.sub.3 H).sub.z (II)R.sup.3 --SO.sub.3 H (III)wherein R.sup.1 is an alkyl group containing 1 or 2 carbon atoms, R.sup.2 is an alkyl group containing at least 12 carbon atoms, R.sup.3 is an aliphatic group containing at least 15 carbon atoms, T is a benzene or naphthalene nucleus and within (I), x, y and z are each independently an integer of 1 up to 3 times the number of aromatic nuclei present in T with the proviso that the sum of x, y and z does not exceed the unsatisfied valences of T or within (II), y is an integer of from 1 to 3 and z is an integer of from 1 to 4 with the proviso that the sum of y and z does not exceed the unsatisfied valences of T or a calcium salt of a sulfonic acid, with at least one alcohol wherein the alcohol is a mixture of methanol, isobutyl alcohol and amyl alcohol, a diluent oil, a carboxylic acid, wherein the carboxylic acid is a polybasic carboxylic acid of the formula ##STR9## wherein R.sup.4 is an aliphatic hydrocarbon based group of from 4 to 400 aliphatic carbon atoms, an acidic material of calcium chloride, water and calcium oxide to form a mixture;(b) heating the mixture to its reflux point to form a neutral calcium salt of the acid moieties;(c) removing a substantial portion of distillable solvents to form an intermediate residue;(d) adding to the intermediate residue at least one alcohol, a surfactant wherein the surfactant is a calcium salt of a formaldehyde coupled aliphatic phenol, calcium oxide and water such that for every 100 parts of substrate, there are not more than 25 parts water to form an intimate mixture having a direct base number of 90-250;(e) heating said intimate mixture (d) to below its reflux point to form a heated intimate mixture;(f) passing gaseous carbon dioxide into the heated intimate mixture (e) to form an overbased calcium sulfonate and a mixture of calcium hydroxide, calcium carbonate and regenerated water until the direct base number is from 90-150;(g) adding additional calcium oxide until the direct base number is from 90-250 followed by the passing of additional gaseous carbon dioxide until the direct base number is from 90-150;(h) continuing the passing of gaseous carbon dioxide to a direct base number of 0-75 after the last portion of calcium oxide is added;(i) removing any distillable solvents to form a final residue; and(j) filtering the final residue to obtain a substantially solvent-free and solids-free oil soluble overbased calcium sulfonate;with the proviso that calcium oxide is the only substantial source of overbasing calcium.