Carboxylated detergent-dispersant-containing compositions having improved properties in lubricating oils

Abstract

A lubricant additive composition comprising (a) a carboxylated detergent-dispersant obtained by (i) neutralizing alkylphenols using an alkaline earth base in the presence of at least one carboxylic acid that contains from one to four carbon atoms but in the absence of alkali base, dialcohol, and monoalcohol, forming an intermediate product, then (ii) carboxylating the intermediate product using carbon dioxide so that at least 20 mole percent of the original alkylphenol starting material has been converted to single aromatic-ring hydrocarbyl salicylate; and (b) an overbased, non-sulfonate-containing detergent such as, for instance, a hydrocarbyl phenate-carboxylate; a medium overbased salicylate having a total base number of about 50 to 170; a high overbased salicylate having a total base number greater than 170; or an overbased sulfurized hydrocarbyl phenate of alkaline earth metals; and combinations and mixtures thereof. Also provided for are additive packages and finished lubricating oil compositions comprising the same. The compositions of this invention reduce sludge and contaminant formation, especially in low and medium speed diesel engines and in marine diesel engines.

What is claimed is:  
     
         1 . A lubricant additive composition comprising: 
 (a) a carboxylated detergent-dispersant obtained by: 
 (i) neutralizing alkylphenols using an alkaline earth base in the presence of at least one carboxylic acid that contains from one to four carbon atoms but in the absence of alkali base, dialcohol, and monoalcohol, forming an intermediate product; and  
 (ii) carboxylating the intermediate product using carbon dioxide so that at least 20 mole percent of the original alkylphenol starting material has been converted to alkaline earth metal single aromatic-ring hydrocarbyl salicylate; and,  
   (b) at least one overbased, non-sulfonate-containing detergent.    
     
     
         2 . The lubricant additive composition according to  claim 1  wherein said overbased, non-sulfonate-containing detergent is selected from the group consisting of: 
 (a) phenates;  
 (b) phenate-carboxylates;  
 (c) salicylates;  
 and mixtures and combinations thereof.  
 and mixtures and combinations thereof.  
 
     
     
         3 . The lubricant additive composition according to  claim 1  wherein said overbased, non-sulfonate-containing detergent is selected from the group consisting of: 
 (a) sulfurized hydrocarbyl phenates;  
 (b) hydrocarbyl phenate-carboxylates;  
 (c) medium overbased salicylates;  
 (d) high overbased salicylates;  
 and mixtures and combinations thereof.  
 
     
     
         4 . The lubricant additive composition according to  claim 1  wherein said overbased, non-sulfonate-containing detergent is selected from the group consisting of: 
 (a) sulfurized hydrocarbyl phenates of alkaline earth metals;  
 (b) hydrocarbyl phenate-stearates;  
 (c) medium overbased salicylates;  
 (d) high overbased salicylates;  
 and mixtures and combinations thereof.  
 
     
     
         5 . The lubricant additive composition according to  claim 4  wherein said alkaline earth metal is calcium.  
     
     
         6 . A lubricant additive composition comprising: 
 (a) a carboxylated detergent-dispersant obtained by: 
 (i) neutralizing alkylphenols using an alkaline earth base in the presence of at least one carboxylic acid that contains from one to four carbon atoms but in the absence of alkali base, dialcohol, and monoalcohol, forming an intermediate product; and  
 (ii) carboxylating the intermediate product using carbon dioxide so that at least 20 mole percent of the original alkylphenol starting material has been converted to alkaline earth metal single aromatic-ring hydrocarbyl salicylate; and,  
   (b) at least one additive selected from the group consisting of: 
 (i) an overbased sulfurized hydrocarbyl phenate of alkaline earth metals;  
 (ii) an overbased hydrocarbyl phenate-carboxylate;  
 (iii) a medium overbased salicylate having a total base number of about 50 to 170;  
 (iv) a high overbased salicylate having a total base number greater than 170;  
 and combinations and mixtures thereof.  
   
     
     
         7 . The composition of  claim 6  wherein the mass ratio of carboxylated detergent-dispersant to overbased sulfurized hydrocarbyl phenate is from 0.5:1 to 6:1.  
     
     
         8 . The composition of  claim 7  wherein the mass ratio of carboxylated detergent-dispersant to overbased sulfurized hydrocarbyl phenate is from 0.67:1 to 3:1.  
     
     
         9 . The composition of  claim 8  wherein the mass ratio of carboxylated detergent-dispersant to overbased sulfurized hydrocarbyl phenate is from 0.75:1 to 2:1.  
     
     
         10 . The composition of  claim 6  wherein the phenate-carboxylate is a phenate-stearate.  
     
     
         11 . The composition of  claim 6  wherein the mass ratio of carboxylated detergent-dispersant to overbased hydrocarbyl phenate-carboxylate is from 0.5:1 to 6:1.  
     
     
         12 . The composition of  claim 11  wherein the mass ratio of carboxylated detergent-dispersant to overbased hydrocarbyl phenate-carboxylate is from 0.75:1 to 3:1.  
     
     
         13 . The composition of  claim 12  wherein the mass ratio of carboxylated detergent-dispersant to overbased hydrocarbyl phenate-carboxylate is from 1.1:1 to 1.5:1.  
     
     
         14 . The composition of  claim 6  wherein the medium overbased salicylate has a base number in the range of 50 to 170.  
     
     
         15 . The composition of  claim 14  wherein the medium overbased salicylate has a base number in the range of 100 to 165.  
     
     
         16 . The composition of  claim 15  wherein the medium overbased salicylate has a base number in the range of 120 to 160.  
     
     
         17 . The composition of  claim 6  wherein the high overbased salicylate has a base number above 170.  
     
     
         18 . The composition of  claim 17  wherein the high overbased salicylate has a base number above 200.  
     
     
         19 . The composition of  claim 18  wherein the high overbased salicylate has a base number above 250.  
     
     
         20 . The composition of  claim 6  wherein the alkaline earth metal of the overbased sulfurized hydrocarbyl phenate of alkaline earth metals is calcium.  
     
     
         21 . A lubricating oil composition comprising: 
 (a) an oil of lubricating viscosity;    (b) a carboxylated detergent-dispersant obtained by: 
 (i) neutralizing alkylphenols using an alkaline earth base in the presence of at least one carboxylic acid that contains from one to four carbon atoms but in the absence of alkali base, dialcohol, and monoalcohol, forming an intermediate product; and  
 (iii) carboxylating the intermediate product using carbon dioxide so that at least 20 mole percent of the original alkylphenol starting material has been converted to alkaline earth metal single aromatic-ring hydrocarbyl salicylate; and,  
   (c) at least one overbased, non-sulfonate-containing detergent.    
     
     
         22 . A lubricating oil composition comprising: 
 (a) an oil of lubricating viscosity;    (b) a carboxylated detergent-dispersant obtained by: 
 (i) neutralizing alkylphenols using an alkaline earth base in the presence of at least one carboxylic acid that contains from one to four carbon atoms but in the absence of alkali base, dialcohol, and monoalcohol, forming an intermediate product; and  
 (ii) carboxylating the intermediate product using carbon dioxide so that at least 20 mole percent of the original alkylphenol starting material has been converted to alkaline earth metal single aromatic-ring hydrocarbyl salicylate; and,  
   (c) at least one additive selected from the group consisting of: 
 (i) an overbased sulfurized hydrocarbyl phenate of alkaline earth metals;  
 (ii) an overbased hydrocarbyl phenate-carboxylate;  
 (iii) a medium overbased salicylate having a total base number of about 50 to 170;  
 (iv) a high overbased salicylate having a total base number greater than 170;  
 and combinations and mixtures thereof.  
   
     
     
         23 . The composition of  claim 22  wherein the phenate-carboxylate is a phenate-stearate.  
     
     
         24 . An additive package comprising: 
 (a) from about 10 to 75 mass percent of the composition according to  claim 1;  and    (b) from about 25 to 90 mass percent of one or more of additives selected from the group consisting of ashless dispersants, detergents, sulfurized hydrocarbons, dialkyl hydrogen phosphates, zinc dithiophosphates, dialkyl hydrogen phosphates, pentaerythritol monooleate, 2,5-dimercapto thiadiazole, benzotriazole, foam inhibitors, and imidazolines; wherein the mass percent of each component is based on the total mass of the composition.    
     
     
         25 . An additive package comprising: 
 (a) from about 10 to 75 mass percent of the composition according to  claim 6;  and    (b) from about 25 to 90 mass percent of one or more of additives selected from the group consisting of ashless dispersants, detergents, sulfurized hydrocarbons, dialkyl hydrogen phosphates, zinc dithiophosphates, dialkyl hydrogen phosphates, pentaerythritol monooleate, 2,5-dimercapto thiadiazole, benzotriazole, foam inhibitors, and imidazolines; wherein the mass percent of each component is based on the total mass of the composition.    
     
     
         26 . A method of improving the detergent and dispersant properties of lubricating oils, comprising adding to said oils an effective detergent amount of the additive composition of  claim 1 .  
     
     
         27 . A method of improving the detergent and dispersant properties of lubricating oils, comprising adding to said oils an effective detergent amount of the additive composition of  claim 6.