Emulsifier/detergent compounds for metalworking lubricants

Abstract

Metal sulfonate emulsifier and detergent compounds for use with various metalworking lubricants are taught together with the method of preparing same. The sulfonates are prepared by co-sulfonating selected alkylbenzenes and certain oils with oleum. More specifically, the method involves preparation of a complex mixture of alkylbenzenes and lubricating oils, sulfonation by means of oleum only, and conversion to a metal sulfonate via specific processing steps.

1 . A process for preparing a metal sulfonate useful as an emulsifier or detergent in metalworking liquids, wherein said metal sulfonate is selected from the group consisting of lithium, sodium, potassium, calcium or mixtures thereof, said method comprising: 
 A. Forming an admixture consisting essentially of linear monoalkylbenzenes, unbranched dialkylbenzenes, c-1 methyl branched dialkylbenzenes, at least two different paraffinic oils and a volatile paraffinic solvent;    B. Sulfonating said admixture with 20 percent (20%) oleum at mole ratios of about 1.1 mole to 1.4 mole of oleum per mole of aromatic compound at temperatures 70° C. or below;    C. Separating the spent sulfuric acid from the resulting sulfonic acid;    D. Neutralizing the sulfonic acid with lithium, sodium, potassium or calcium hydroxide or oxide or mixtures thereof;    E. Separating or centrifuging the neutral metal sulfonate from any by-product metal sulfates; and    F. Stripping the final product free of any solvent and/or water.    
     
     
         2 . The method defined in  claim 1  and further characterized as including a paraffinic volatile solvent selected from the group consisting of hexane, isohexane, heptane, isoheptane, octane, isooctane and others with an IBP of 250° F. or less.  
     
     
         3 . The method of  claim 2  wherein the amounts of solvent, oils, and alkylbenzene compounds are such that the admixture contains the following amount of materials:  
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                     
                 
                     
                     
                   Parts by Weight 
                 
                     
                     
                 
                     
                   Heavy paraffinic oil 
                   2-15 
                 
                     
                   Light Paraffinic oil 
                   2-15 
                 
                     
                   Linear monoalkylbenzene 
                   5-18 
                 
                     
                   Unbranched Dialkylbenzene 
                   10-25  
                 
                     
                   C-1 Methyl Branched Dialkylbenzene 
                   2-10 
                 
                     
                   Volatile Solvent 
                   20-70  
                 
                     
                     
                 
                     
                     
                 
             
                
                
                
                
               
               
                
                
                
                
                
                
                
                
               
            
           
         
       
     
     
         4 . The method of  claim 2  wherein the solvent dewaxed heavy paraffinic oil or heavy lubricating oil has a viscosity index of at least 90, an initial boiling point of at least 330° C. a viscosity of at least 100 cSt at 40° C. and a Cleveland Open Cup flash point of at least 240° C.  
     
     
         5 . The method of  claim 2  wherein the solvent dewaxed light paraffinic oil or light lubricating oil has a viscosity index of at least 90, an initial boiling point of at least 320° F., a viscosity of at least 10 cSt at 100° C. and a Cleveland Open Cup flash point of at least 210° C.  
     
     
         6 . The method of  claim 2  wherein the linear monoalkylbenzene has alkyl side chains of 10-14 carbon atoms, has a molecular weight of at least 225 and a boiling point of at least 250° C.  
     
     
         7 . The method of  claim 2  wherein the unbranched dialkylbenzene has two alkyl side chains of C 10 -C 14  carbon side chains, has a molecular weight of at least 335 and an initial boiling point of at least 300° C.  
     
     
         8 . The method of  claim 2  wherein the C-1 methyl branched dialkylbenzene has two alkyl side chains containing C 10 -C 13  alkyl groups, has a molecular weight of at least 375 and an initial boiling point of at least 340° C.  
     
     
         9 . The method of  claim 2  wherein the solvent is selected from the group consisting of heptane or naphtha.  
     
     
         10 . The method of  claim 2  wherein the oleum used is selected from 15 percent (15%) oleum to 25 percent (25%) oleum.  
     
     
         11 . The method of  claim 2  wherein the oleum used is 20 percent (20%) and the mole ratio is 1.2-1.4 moles of oleum per mole of sulfonatables.  
     
     
         12 . The method of  claim 2  wherein the metal sulfonate is a sodium sulfonate having the following composition and properties:  
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                     
                 
                     
                     
                   Parts by Weight 
                 
                     
                     
                 
                     
                   % Sodium sulfonate 
                   30-70 
                 
                     
                   % Oil 
                   30-70 
                 
                     
                   Molecular weight 
                   430-480 
                 
                     
                   Viscosity, SUS @ 100° F. 
                   30-75 
                 
                     
                   Specific gravity 
                   0.94-0.99 
                 
                     
                   Flash, COC ° F., minimum 
                   350 
                 
                     
                     
                 
                     
                     
                 
             
                
                
                
                
               
               
                
                
                
                
                
                
                
                
               
            
           
         
       
     
     
         13 . The method of  claim 2  wherein the metal sulfonate is a sodium sulfonate prepared from 25 percent (25%) linear monoalkylbenzene, 41 percent (41%) unbranched dialkylbenzene, 14 percent (14%) C-1 methyl branched dialkylbenzene, ten percent (10%) heavy paraffinic oil and ten percent (10%) light paraffinic oil.  
     
     
         14 . The method of  claim 2  wherein the metal sulfonate is a sodium sulfonate prepared from 17 percent (17%) linear monoalkylbenzene, 31 percent (31%) unbranched dialkylbenzene, 12 percent (12%) C-1 methyl branched dialkylbenzene, 20 percent (20%) heavy paraffinic oil and 20 percent (20%) light paraffinic oil.  
     
     
         15 . The method of  claim 2  wherein the metal sulfonate is a sodium sulfonate prepared from mixtures of products outlined in claims  13  and  14 .  
     
     
         16 . The method of  claim 2  wherein the metal sulfonate is a lithium sulfonate prepared from the mixtures of products outlined in claims  13  and  14 .  
     
     
         17 . The method of  claim 2  wherein the metal sulfonate is a potassium sulfonate prepared from the mixtures of products outlined in claims  13  and  14 .  
     
     
         18 . The method of  claim 2  wherein the metal sulfonate is a calcium sulfonate prepared from the mixtures of products outlined in claims  13  and  14 .