Highly basic calcium carboxylate compositions and method of preparation

Abstract

Environmentally friendly, shelf-stable overbased calcium carboxylate compositions and their method of preparation are described. The subject compositions possess anti-oxidation and anti-wear properties superior to those associated with existing sulfonate compositions. The subject compositions are prepared by neutralizing a mixture of two different molecular weight aliphatic carboxylic acids or anhydrides in the presence of an aromatic or aliphatic hydrocarbon solvent; adding a mixture of calcium oxide and calcium hydroxide; adding methyl alcohol to promote the reaction; carbonating the mixture with carbon dioxide at temperatures between 80° F. and 120° F.; heating to 200°-250° F. and finishing carbonation; adding diluent oil to the crude product; clarifying the product in solvent; and removing the solvent.

1 . A process for the preparation of a highly basic calcium carboxylate composition comprising the steps of:
 a. neutralizing a mixture of two different molecular weight aliphatic carboxylic acids or anhydrides in the presence of an aromatic or aliphatic hydrocarbon solvent, said lower molecular weight carboxylic acid having 15 to 25 aliphatic carbon atoms, said higher molecular weight carboxylic acid having 40 to 100 aliphatic carbon atoms;   b. adding a mixture of calcium oxide and calcium hydroxide;   c. adding methyl alcohol to promote the reaction;   d. carbonating the mixture with carbon dioxide at temperatures between 80° F. and 120° F.;   e. heating to 200°-250° F. and finishing carbonation;   f. adding diluent oil to the crude product;   g. clarifying the product in solvent; and   h. removing the solvent.   
   
   
       2 . The process according to  claim 1  wherein the total carboxylic acid and acid anhydride used is ten percent. 
   
   
       3 . The process according to  claim 1  wherein the total carboxylic acid and acid anhydride used is 40 percent. 
   
   
       4 . The process according to  claim 1  wherein the weight ratio of high molecular weight carboxylic acid or anhydride to low molecular weight carboxylic acid is one part to three parts. 
   
   
       5 . The process according to  claim 1  wherein the weight ratio of higher molecular weight carboxylic acid or anhydride to lower molecular weight carboxylic acid is one part to 20 parts. 
   
   
       6 . The process according to  claim 1  wherein the lower molecular weight carboxylic acid is oleic acid and the higher molecular weight carboxylic acid is polyisobutenyl succinic acid or polyisobutenyl succinic anhydride. 
   
   
       7 . The process according to  claim 1  wherein the lower molecular weight carboxylic acid is a tall oil fatty acid and the higher molecular weight carboxylic acid is polyisobutenyl succinic acid or anhydride. 
   
   
       8 . The process according to  claim 1  wherein the mole ratio of carbon dioxide is in a range of 0.78 to 0.88 moles of carbon dioxide per mole of the calcium oxide and calcium hydroxide used for overbasing. 
   
   
       9 . The process according to  claim 1  wherein the volatile solvent used is selected from the group consisting of xylene, heptane, naphtha and mineral spirits. 
   
   
       10 . The process according to  claim 1  wherein the diluent oil is a naphthenic or paraffinic non-volatile hydrocarbon oil. 
   
   
       11 . A highly basic calcium carboxylate composition prepared by a process comprising the steps of:
 a. neutralizing a mixture of two different molecular weight aliphatic carboxylic acids or anhydrides in the presence of an aromatic or aliphatic hydrocarbon solvent, said lower molecular weight carboxylic acid having 15 to 25 aliphatic carbon atoms, said higher molecular weight carboxylic acid having 40 to 100 aliphatic carbon atoms;   b. adding a mixture of calcium oxide and calcium hydroxide;   c. adding methyl alcohol to promote the reaction;   d. carbonating the mixture with carbon dioxide at temperatures between 80° F. and 120° F.;   e. heating to 200°-250° F. and finishing carbonation;   f. adding diluent oil to the crude product;   g. clarifying the product in solvent; and   h. removing the solvent.   
   
   
       12 . The highly basic calcium carboxylate composition of  claim 11  wherein the total carboxylic acid and acid anhydride used is ten percent. 
   
   
       13 . The highly basic calcium carboxylate composition of  claim 11  wherein the total carboxylic acid and acid anhydride used is 40 percent. 
   
   
       14 . The highly basic calcium carboxylate composition of  claim 11  wherein the weight ratio of high molecular weight carboxylic acid or anhydride to low molecular weight carboxylic acid is one part to three parts. 
   
   
       15 . The highly basic calcium carboxylate composition of  claim 11  wherein the weight ratio of higher molecular weight carboxylic acid or anhydride to lower molecular weight carboxylic acid is one part to 20 parts. 
   
   
       16 . The highly basic calcium carboxylate composition of  claim 11  wherein the lower molecular weight carboxylic acid is oleic acid and the higher molecular weight carboxylic acid is polyisobutenyl succinic acid or polyisobutenyl succinic anhydride. 
   
   
       17 . The highly basic calcium carboxylate composition of  claim 11  wherein the lower molecular weight carboxylic acid is a tall oil fatty acid and the higher molecular weight carboxylic acid is polyisobutenyl succinic acid or anhydride. 
   
   
       18 . The highly basic calcium carboxylate composition of  claim 11  wherein the mole ratio of carbon dioxide is in a range of 0.78 to 0.88 moles of carbon dioxide per mole of the calcium oxide and calcium hydroxide used for overbasing. 
   
   
       19 . The highly basic calcium carboxylate composition of  claim 11  wherein the volatile solvent used is selected from the group consisting of xylene, heptane, naphtha and mineral spirits. 
   
   
       20 . The highly basic calcium carboxylate composition of  claim 11  wherein the diluent oil is a naphthenic or paraffinic non-volatile hydrocarbon oil.