Lubricating oil additives

Abstract

Improved stability of overbased phenates, particularly when formulated with overbased sulphonates, as well as improved foaming tendency and viscosity is obtained by treated the overbased phenate, either during or subsequent to the overbasing process, with from 0.1 to 10 wt. %, preferably 2 to 6 wt. %, of a carboxylic acid with a C 10 to C 24 unbranched segment, e.g. behenic acid.

We claim: 
     
       1. An additive concentrate for incorporation in lubricating oil composition consisting essentially of lubricating oil; and from 10 to 90 wt. % of overbased alkaline earth metal hydrocarbyl sulphurized phenate which has been treated, either during or subsequent to overbasing, with from 0.1 to 10 weight %, based on the weight of the additive concentrate, of stearic acid or anhydride or salt thereof, and which has a total base number of 235-.[.300.]. .Iadd.about 260.Iaddend.. 
     
     
       2. An additive concentrate as claimed in claim 1, which contains from 30 to 90 wt. % of the overbased phenate. 
     
     
       3. An additive concentrate as claimed in claim 1, in which the overbased phenate is an overbased alkaline earth metal sulphurized alkyl phenate comprising C 9  to C 18  alkyl groups. 
     
     
       4. An additive concentrate as claimed in claim 1, in which the overbased phenate is an overbased calcium phenate or an overbased magnesium phenate. 
     
     
       5. An additive concentrate as claimed in claim 1, in which from 2 to 6 weight % of the acid or anhydride or salt thereof, is employed. 
     
     
       6. An additive concentrate for incorporation in a lubricating oil composition consisting essentially of lubricating oil; from 10 to 90 wt. % of overbased alkaline earth metal hydrocarbyl sulphurized phenate which has been treated, either during or subsequent to overbasing, with from 0.1 to 10 weight % of stearic acid or anhydride or salt thereof, and which has a total base number of 235-.[.300.]. .Iadd.about 260 .Iaddend.and at least 0.1 wt. % of material selected from the group consisting of polyhydric alcohol having from 2 to 4 carbon atoms, di- or tri- (C 2  -C 4 ) glycol and ether alcohol having from 2 to 10 carbon atoms. 
     
     
       7. A process for preparing an improved additive concentrate consisting essentially of adding to lubricating oil from 10 to 90 wt. %, based on the weight of the total additive concentrate, of overbased alkaline earth metal hydrocarbyl sulphurized phenate having a total base number of 235-.[.300.]. .Iadd.about 260.Iaddend., and from 0.1 to 10 weight %, based on the weight of the total additive concentrate, of stearic acid or anhydride or salt thereof, wherein said concentrate is improved in at least one of reduced tendency to sedimentation, reduced foaming and reduced viscosity. 
     
     
       8. A process as claimed in claim 7, in which the acid or anhydride or salt thereof is introduced at a temperature of from 20° C. to 210° C. 
     
     
       9. A process as claimed in claim 8, in which the temperature is from 80° C. to 140° C. 
     
     
       10. A process for preparing improved additive concentrate consisting essentially of adding to lubricating oil from 10 to 90 wt. % of overbased alkaline earth metal hydrocarbyl sulphurized phenate having a total base number of 235-.[.300.]. .Iadd.about 260.Iaddend., from 0.1 to 10 weight % of stearic acid or anhydride or salt thereof; and at least 0.1 wt. % of material selected from the group consisting of polyhydric alcohol containing from 2 to 4 carbon atoms, di- or tri- (C 2  -C 4 ) glycol or ether alcohol having from 2 to 10 carbon atoms, wherein said concentrate is improved in at least one of tendency to sedimentation, foaming and viscosity. 
     
     
       11. A lubricating oil composition comprising from 0.01 to 30 wt. %, based on the total composition weight, of additive concentrate in solution in lubricating oil, the additive concentrate consisting essentially of lubricating oil, and from 10 to 90 wt. % of an overbased alkaline earth metal hydrocarbyl sulphurized phenate which has been treated, either during or subsequent to the overbasing process, with from 0.1 to 10 wt. %, based on the weight of the additive concentrate, of stearic acid or anhydride or salt thereof, and which has a total base number of 235-.[.300.]. .Iadd.about 260.Iaddend.. 
     
     
       12. A composition as claimed in claim 11, which contains from 0.5 to 20 wt. % of the additive concentrate. 
     
     
       13. A method for reducing the viscosity of an additive concentrate consisting essentially of lubricating oil and from 10 to 90 wt. % of overbased alkaline earth metal hydrocarbyl sulphurized phenate having a total base number of 235-.[.300.]. .Iadd.about 260 .Iaddend.consisting essentially of treating the phenate, either during or subsequent to overbasing, with from 0.1 to 10 wt. %, based on the weight of the additive concentrate, of stearic acid or anhydride or salt thereof. 
     
     
       14. A method according to claim 13, wherein said alkaline earth metal is selected from the group consisting of calcium and magnesium; and wherein said hydrocarbyl is C 8  to C 18  alkyl group. .Iadd. 
     
     
       15.  An additive concentrate for incorporation in lubricating oil composition consisting essentially of lubricating oil; and from 10 to 90 wt. % of overbased alkaline earth metal hydrocarbyl sulphurized phenate which has been treated, either during or subsequent to overbasing, with from 0.1 to 10 weight %, based on the weight of the additive concentrate, of stearic acid or anhydride or salt thereof, and having a total base number of at least 235. .Iaddend..Iadd.16. An additive concentrate as claimed in claim 15, which contains from 30 to 90 wt. % of the overbased phenate. .Iaddend..Iadd.17. An additive concentrate as claimed in claim 15, in which the overbased phenate is an overbased alkaline earth metal sulphurized alkyl phenate comprising C 9  to C 18  alkyl groups. .Iaddend..Iadd.18. An additive concentrate as claimed in claim 15, in which the overbased phenate is an overbased calcium phenate or an overbased magnesium phenate. .Iaddend..Iadd.19. An additive concentrate as claimed in claim 15, in which from 2 to 6 weight % of the acid or 
     
     
        anhydride or salt thereof, is employed. .Iaddend..Iadd.20.  An additive concentrate for incorporation in a lubricating oil composition consisting essentially of lubricating oil; from 10 to 90 wt. % of overbased alkaline earth metal hydrocarbyl sulphurized phenate which has been treated, either during or subsequent to overbasing, with from 0.1 to 10 weight % of stearic acid or anhydride or salt thereof, and having a total base number of at least 235; and at least 0.1 wt. % of material selected from the group consisting of polyhydric alcohol having from 2 to 4 carbon atoms, di- or tri-(C 2  -C 4 ) glycol and ether alcohol having from 2 to 10 carbon atoms. .Iaddend..Iadd.21. A process for preparing an improved additive concentrate consisting essentially of adding to lubricating oil from 10 to 90 wt. %, based on the weight of the total additive concentrate, of overbased alkaline earth metal hydrocarbyl sulphurized phenate having a total base number of at least 235, and from 0.1 to 10 weight %, based on the weight of the total additive concentrate, of stearic acid or anhydride or salt thereof, wherein said concentrate is improved in at least one of reduced tendency to sedimentation, reduced foaming and reduced viscosity. .Iaddend..Iadd.22. A process as claimed in claim 21, in which the acid or anhydride or salt thereof is introduced at 
     
     
        a temperature of from 20° C. to 210° C. .Iaddend..Iadd.23. A process as claimed in claim 22, in which the temperature is from 80° C. to 140° C. .Iaddend..Iadd.24. A process for preparing improved additive concentrate consisting essentially of adding to lubricating oil from 10 to 90 wt. % of overbased alkaline earth metal hydrocarbyl sulphurized phenate having a total base number of at least 235; from 0.1 to 10 weight % of stearic acid or anhydride or salt thereof; and at least 0.1 wt. % of material selected from the group consisting of polyhydric alcohol containing from 2 to 4 carbon atoms, di- or tri- (C 2  -C 4 ) glycol or ether alcohol having from 2 to 10 carbon atoms, wherein said concentrate is improved in at least one of tendency to sedimentation, foaming and viscosity. .Iaddend..Iadd.25. A lubricating oil composition comprising from 0.01 to 30 wt. %, based on the total composition weight, of additive concentrate in solution in lubricating oil, the additive concentrate consisting essentially of lubricating oil, and from 10 to 90 wt. % of an overbased alkaline earth metal hydrocarbyl sulphurized phenate which has been treated, either during or subsequent to the overbasing process, with from 0.1 to 10 wt. %, based on the weight of the additive concentrate, of stearic acid or anhydride or salt thereof, and having a total base number of at least 235. .Iaddend..Iadd.26. A composition as claimed in claim 25, which contains from 0.5 to 20 wt. % of 
     
     
        the additive concentrate. .Iaddend..Iadd.27.  A method for reducing the viscosity of an additive concentrate consisting essentially of lubricating oil and from 10 to 90 wt. % of overbased alkaline earth metal hydrocarbyl sulphurized phenate having a total base number of at least 235 consisting essentially of treating the phenate, either during or subsequent to overbasing, with from 0.1 to 10 wt. %, based on the weight of the additive concentrate, of stearic acid or anhydride or salt thereof. .Iaddend..Iadd.28. A method according to claim 27, wherein said alkaline earth metal is selected form the group consisting of calcium and magnesium; and wherein said hydrocarbyl is C 2  to C 18  alkyl group. .Iaddend.