Phenate Detergent Preparation

Abstract

A sulphurised calcium phenate detergent prepared by the following stages: i) reacting one or more alkyl phenol materials comprising hydrogenated distilled cashew nut shell liquid with first defined amounts of a calcium salt and of a promoter, and with sulphur, in the presence of a process solvent; and (ii) reacting the product of stage (i) with second defined amounts of the calcium salt and of the promoter and carbonating the product; the total amount of calcium salt and of promoter being such as to provide a sulphurised phenate of desired TBN, and the first amount of each of the calcium salt and of the promoter in stage (i), relative to its total amount in the method, being less than 50, expressed as a molar percentage. The sulphurised calcium phenate has a kinematic viscosity at 100° C. of greater than 750 and less than 1200 cSt.

What is claimed is: 
     
         1 . A method of making a sulphurised calcium phenate detergent comprising the steps of:
 (i) reacting one or more alkyl phenol materials comprising hydrogenated distilled cashew nut shell liquid with first defined amounts of a calcium salt (such as calcium oxide or calcium hydroxide) and of an alcohol, with sulphur, in the presence of a solvent; and   (ii) reacting the product of step (i) with second defined amounts of the calcium salt and of the alcohol and carbonating the product;   
       the total amount of calcium salt and of alcohol being such as to provide a sulphurised calcium phenate of desired TBN; and wherein the first amount of each of the calcium salt and of the alcohol in step (i), relative to its total amount in the method, is less than 50, expressed as a molar percentage. 
     
     
         2 . The method of  claim 1 , wherein said sulphur is elemental sulphur. 
     
     
         3 . The method of  claim 1 , wherein the first amount of each of the calcium salt and of the alcohol in step (i), relative to its total amount in the method, is less than 30, expressed as a molar percentage. 
     
     
         4 . The method of  claim 1 , wherein the first amount of each of the calcium salt and of the alcohol in step (i), relative to its total amount in the method, is less than 30, expressed as a molar percentage. 
     
     
         5 . The method of  claim 4 , wherein the first amount of each of the calcium salt and of the alcohol in step (i), relative to its total amount in the method, is less than 20, expressed as a molar percentage. 
     
     
         6 . The method of  claim 1 , wherein step (ii) is carried out in the absence of sulphur. 
     
     
         7 . The method of  claim 1 , wherein the alcohol is a mono-, di- or poly-hydric alcohol. 
     
     
         8 . The method of  claim 7 , wherein the alcohol is a 1,2-vicinal diol 
     
     
         9 . The method of  claim 1 , wherein the molar percentage of the first amount of each of the calcium salt and of the alcohol is not less than 5. 
     
     
         10 . The method of  claim 9 , wherein the molar percentage of the first amount of each of the calcium salt and of the alcohol is not less than 10. 
     
     
         11 . The method of  claim 1 , wherein the calcium salt is calcium oxide or calcium hydroxide. 
     
     
         12 . The method of  claim 1 , wherein the alkyl phenol material comprises 3-pentadecylphenol. 
     
     
         13 . The method of  claim 1  carried out in the presence of a carboxylic acid or anhydride. 
     
     
         14 . The method of  claim 13 , wherein the carboxylic acid or anhydride is stearic acid or a polyisobutene succinic anhydride. 
     
     
         15 . A sulphurised calcium phenate detergent obtainable by the method of  claim 1 , the sulphurised calcium phenate detergent having a kinematic viscosity at 100° C. of greater than 750 and less than 1200 cSt, as measured by ASTM D445. 
     
     
         16 . The sulphurised calcium phenate detergent of  claim 15 , having a kinematic viscosity at 100° C. of greater than 800 and less than 1150 cSt, preferably greater than 800 and less than 1150 cSt, as measured by ASTM D445. 
     
     
         17 . A lubricating oil composition comprising, in a major amount, an oil of lubricating viscosity and, in a minor amount, a detergent of  claim 15 . 
     
     
         18 . The lubricating oil composition of  claim 17 , wherein the oil of lubricating viscosity contains 50 mass % or more of a basestock containing greater than or equal to 90% saturates and less than or equal to 0.03% sulphur or a mixture thereof. 
     
     
         19 . The lubricating oil composition of  claim 17  in the form of a marine diesel cylinder lubricant. 
     
     
         20 . The lubricating oil composition of  claim 18  in the form of a marine diesel cylinder lubricant. 
     
     
         21 . The lubricating oil composition of  claim 17  in the form of a marine diesel trunk piston engine oil. 
     
     
         22 . The lubricating oil composition of  claim 18  in the form of a marine diesel trunk piston engine oil. 
     
     
         23 . A method of operating an internal combustion diesel engine comprising fuelling the engine, and lubricating the engine with a lubricating oil composition of  claim 17 . 
     
     
         24 . A method of operating an internal combustion diesel engine comprising fuelling the engine, and lubricating the engine with a lubricating oil composition of  claim 18 .