Manufacture of zinc salts of high molecular weight alkylated hydroxy aromatic compounds

Claim 1

IN THE MANUFACTURE OF A ZINC SALT OF AN ALKYL SUBSTITUTED HYDROXY AROMATIC HYDROCARBON CONSISTING OF CARBON, HYDROGEN AND OXYGEN, WHEREIN THE ALKYL SUBSTITUENT ON THE RING CONTAINS FROM 15 TO 30 CARBON ATOMS, THE IMPROVEMENT TO OBTAIN A ZINC SALT OF AT LEAST 1% BY WEIGHT SOLUBILITY IN A RESIDUAL MINERAL LUBRICATING OIL OF THE AIRPLANE ENGINE OIL TYPE AND WHICH HAS EFFECTIVE ENGINE CLEANLINESS PROPERTIES, WHICH COMPRISES MIXING UNDER SUBSTANTIALLY ANHYDROUS CONDITIONS AND IN THE PROPORTION OF SUBSTANTIALLY ONE MOLAR AMOUNT OF AN ALKYL SUBSTITUTED HYDROXY AROMATIC HYDROARBON CONSISTING OF CARBON, HYDROGEN AND OXYGEN, ONE MOLAR AMOUNT OF AN ALKALI METAL ALCOHOLATE OF AN ALIPHATIC ALCOHOL CONTAINING 4 TO 6 CARBON ATOMS IN THE MOLECULE AND BOILING ABOVE THE BOILING POINT OF WATER, SAID ALKALI METAL ALCOHOLTE BEING IN SOLUTION IN AN EXCESS OF THE SAID ANHYDROUS ALCOHOL, AND SLIGHTLY MORE THAN ONEHALF MOLAR AMOUNT OF A SOLUBLE ZINC SALT WHOSE ACIDIC PORTION FORMS AN ALKALI METAL SALT WHICH IS INSOLUBLE IN THE SAID ANHYDROUS ALCOHOL, REACTING THE SAID MIXTURE UNDER REFLUXING CONDITIONS OF THE SAID C4 TO C6 ALIPHATIC ALCOHOL FOR A PERIOD OF TIME IN EXCESS OF 20 HOURS TO PRODUCE AN ANHYDROUS ALCOHOL SLUTION OF THE ZINC SALT OF THE ALKYL SUBSTITUTED HYDROXY AROMATIC HYDROCARBON IN WHICH THE ALKALI METAL SALT IS PRECIPITATED, FILTERING TO REMOVE THE PRECIPITATED ALKALI METAL SALT, ADDING TO THE FILTRATE A DRY MINERAL LUBRICATING OIL, AND STRIPPING TO REMOVE THE ALCOHOL UNDER ANHYDROUS CONDITIONS TO RECOVER AN ANHYDROUS MINERAL LUBRICATING OIL CONCENTRATE OF THE SAID ZINC SALT HAVING THE AFOREMENTIONED PROPERTIES.