Patent GB-736728-A (GB)
Title: Improvements in or relating to sulfonation of lube oil distillates
Inventor: PALTZ WALTER JOSEPH
IPC: C07C309/62
Filed: 1953-05-15
Abstract: Oil-soluble petroleum sulphonic acids are obtained by mixing a petroleum hydrocarbon oil having a normal undiluted viscosity of 100-2000 seconds Saybolt at 100 DEG  F. with a petroleum naphtha which is an aliphatic petroleum hydrocarbon fraction free of olefines and aromatics and of B.R. 100-200 DEG  C. and being present in a quantity sufficient to reduce the viscosity of the petroleum hydrocarbon oil to less than 100 seconds Saybolt at 100 DEG  F.; subjecting the resultant mixture to a single treat with sulphuric acid with intimate mixing for less than 15 minutes at a maximum temperature of 160 DEG  F.; adding water to the sulphonated mixture in an amount not more than 50 volume per cent based on sulphuric acid and stratifying and separating the resultant mixture into an oil layer containing the sulphonic acids and an aqueous sludge. The sulphonic acids may be subsequently converted to their alkali metal, alkali earth metal or nitrogen base salts.  Sodium, potassium, calcium, barium, magnesium and ammonium salts are specified.  The petroleum hydrocarbon oil may have been previously acid-treated, deasphalted, dewaxed or solvent extracted with e.g. ketones, nitrobenzene, phenol or cresol, and may be a distillate, neutral or bright stock but is still reactive to sulphuric acid.  A preferred range of 130-140 DEG  F. is maintained during sulphonation. Sulphuric acid of 100 per cent up to 65 per cent dissolved SO3 or a stabilized liquid anhydrous SO3 may be used.  Contact times of 1-5 minutes are indicated although in some cases a time of 20 seconds suffices. Intimate mixing is essential, e.g. equivalent to that obtained in a colloid mill.  In an illustration an extracted Coastal distillate of viscosity 500 seconds Saybolt at 100 DEG  F. is diluted with an equal volume of a predominantly paraffinic naphtha of B.R. 100-200 DEG  C., treated for one-and-a-quarter minutes with 7 per cent by volume based on undiluted feed of fuming sulphuric acid containing 60 per cent dissolved SO3 at 130-140 DEG  F. and 30 per cent of water based on sulphuric acid is added to the products which are then allowed to settle.  Generally the sulphonic acids in the oil layer are neutralized, e.g. with caustic soda (optionally in 40-60 per cent isopropanol) or soda ash, calcium carbonate or hydroxide, barium hydroxide or nitrogen bases, the soaps extracted with aqueous alcohol solution, e.g. 40-80 per cent aqueous isopropanol or 50 per cent aqueous ethanol, and the soap recovered by solvent removal. Sodium soaps may be converted into alkaline earth sulphonates by double decomposition reactions. The products are lubricating oil additives.  Examples are provided showing the treatment of extracted Coastal distillates, the sulphonate being obtained as the calcium salt.ALSO:Mineral lubricating-oil compositions comprise as detergents oil-soluble petroleum sulphonic acids and salts thereof made by mixing a petroleum hydrocarbon oil of normal undiluted viscosity of 100-2000 seconds Saybolt at 100 DEG  F. with a petroleum naphtha which is an aliphatic petroleum hydrocarbon fraction free of olefines and aromatics and of B.R. within 100-200 DEG  C. and present in a quantity sufficient to reduce the viscosity of the petroleum hydrocarbon oil to less than 100 seconds Saybolt at 100 DEG  F., subjecting the resultant mixture to a single treat with sulphuric acid with intimate mixing for less than 15 minutes at a maximum temperature of 160 DEG  F.; adding water to the sulphonated mixture in an amount not more than 50 volume per cent based on sulphuric acid and stratifying and separating the resultant mixture into an oil layer containing the sulphonic acids and an aqueous sludge with subsequent conversion of the acids to their salts if desired. Alkali metal, alkaline earth metal or nitrogen base salts are mentioned, e.g. sodium, potassium, calcium, barium, magnesium and ammonium salts.  The petroleum hydrocarbon oil may have been previously acid-treated, deasphalted, dewaxed or solvent extracted and may be a distillate, neutral or bright stock.  In example (3) calcium sulphonates prepared as above from mixtures of extracted Coastal oils of viscosity 500 and 910 seconds Saybolt at 100 DEG  F. with a petroleum naphtha of B.R. 116-143 DEG  C. are added in about 1 per cent by weight to a paraffin, phenol extracted lubricating oil, and the detergent properties of the composition examined.