Lubricating oil compositions and methods of use

Abstract

This disclosure relates to a method for improving air release in a lubricating oil. The method involves formulating a composition having at least one lubricating oil base stock as a major component, and one or more lubricating oil additives, as a minor component. The one or more lubricating oil additives include at least one polyalkylene glycol. The at least one polyalkylene glycol is soluble in the at least one lubricating oil base stock. The weight ratio of the at least one polyalkylene glycol to the at least one lubricating oil base stock is from about 1:99 to about 7:93. During operation of a lubricating system containing the lubricating oil, release of entrained air in the lubricating oil is improved, as determined by ASTM D-3427-15, as compared to release of entrained air achieved using a lubricating oil containing other than the at least one polyalkylene glycol. This disclosure also relates to lubricating oils having at least one oil soluble polyalkylene glycol (OSP).

What is claimed is: 
     
         1 . A lubricating oil having a composition comprising: at least one lubricating oil base stock as a major component, and one or more lubricating oil additives, as a minor component; wherein the one or more lubricating oil additives comprise at least one polyalkylene glycol, and is other than a sulfurized olefin; wherein the at least one polyalkylene glycol is soluble in the at least one lubricating oil base stock; wherein the weight ratio of the at least one polyalkylene glycol to the at least one lubricating oil base stock is from about 1:99 to about 7:93; wherein, during operation of a lubricating system containing the lubricating oil, release of entrained air in the lubricating oil is improved, as determined by ASTM D-3427-15, as compared to release of entrained air achieved using a lubricating oil containing other than the at least one polyalkylene glycol. 
     
     
         2 . The lubricating oil of  claim 1  wherein, during operation of a lubricating system containing the lubricating oil, the time required for entrained air content to fall to 0.2 volume percent, as determined by ASTM D-3427-15, is reduced at least 5%, as compared to the time required for entrained air content to fall to 0.2 volume percent, using a lubricating oil containing other than the at least one polyalkylene glycol. 
     
     
         3 . The lubricating oil of  claim 1  wherein, during operation of a lubricating system containing the lubricating oil, the time required for entrained air content to fall to 0.2 volume percent, as determined by ASTM D-3427-15, is reduced at least 10%, as compared to the time required for entrained air content to fall to 0.2 volume percent, using a lubricating oil containing other than the at least one polyalkylene glycol. 
     
     
         4 . The lubricating oil of  claim 1  wherein the weight ratio of the at least one polyalkylene glycol to the at least one lubricating oil base stock is from about 1:99 to about 6.5:93.5. 
     
     
         5 . The lubricating oil of  claim 1  wherein the weight ratio of the at least one polyalkylene glycol to the at least one lubricating oil base stock is from about 1:99 to about 4.5:95.5. 
     
     
         6 . The lubricating oil of  claim 1  wherein the at least one polyalkylene glycol comprises from about 25 to about 75 weight percent units derived from butylene oxide and from about 25 to about 75 weight percent units derived from propylene oxide, initiated by one or more initiators selected from monols, diols and polyols. 
     
     
         7 . The lubricating oil of  claim 1  wherein the at least one polyalkylene glycol comprises from about 45 to about 55 weight percent units derived from butylene oxide and about 45 to about 55 weight percent units derived from propylene oxide, initiated by one or more monol initiators. 
     
     
         8 . The lubricating oil of  claim 1  wherein the at least one polyalkylene glycol is selected from the group consisting of copolymers comprising units derived from propylene oxide and butylene oxide, polybutylene oxide homopolymer, and combinations thereof. 
     
     
         9 . The lubricating oil of  claim 1  wherein the at least one polyalkylene glycol has a kinematic viscosity (KV 40 ) from about 15 to about 100 cSt at 40° C. as determined by ASTM D-445-19, and a molecular weight from about 400 to about 1100 grams/mole. 
     
     
         10 . The lubricating oil of  claim 1  wherein the lubricating oil base stock comprises a Group I, Group II, Group III, Group IV or Group V base oil. 
     
     
         11 . The lubricating oil of  claim 1  wherein the lubricating oil base stock is present in an amount of from about 75 weight percent to about 95 weight percent, and the at least one polyalkylene glycol is present in an amount from about 1 to about 7 weight percent, based on the total weight of the lubricating oil. 
     
     
         12 . The lubricating oil of  claim 1  wherein the one or more lubricating oil additives further comprise one or more of an antiwear additive, viscosity modifier, antioxidant, detergent, dispersant, pour point depressant, corrosion inhibitor, metal deactivator, seal compatibility additive, antifoam agent, inhibitor, friction modifier, and anti-rust additive. 
     
     
         13 . A method for improving air release in a lubricating oil, said method comprising:
 formulating a composition comprising at least one lubricating oil base stock as a major component, and one or more lubricating oil additives, as a minor component; wherein the one or more lubricating oil additives comprise at least one polyalkylene glycol, and is other than a sulfurized olefin; wherein the at least one polyalkylene glycol is soluble in the at least one lubricating oil base stock; wherein the weight ratio of the at least one polyalkylene glycol to the at least one lubricating oil base stock is from about 1:99 to about 7:93; wherein, during operation of a lubricating system containing the lubricating oil, release of entrained air in the lubricating oil is improved, as determined by ASTM D-3427-15, as compared to release of entrained air achieved using a lubricating oil containing other than the at least one polyalkylene glycol.   
     
     
         14 . The method of  claim 13  wherein, during operation of a lubricating system containing the lubricating oil, the time required for entrained air content to fall to 0.2 volume percent, as determined by ASTM D-3427-15, is reduced at least 5%, as compared to the time required for entrained air content to fall to 0.2 volume percent, using a lubricating oil containing other than the at least one polyalkylene glycol. 
     
     
         15 . The method of  claim 13  wherein, during operation of a lubricating system containing the lubricating oil, the time required for entrained air content to fall to 0.2 volume percent, as determined by ASTM D-3427-15, is reduced at least 10%, as compared to the time required for entrained air content to fall to 0.2 volume percent, using a lubricating oil containing other than the at least one polyalkylene glycol. 
     
     
         16 . The method of  claim 13  wherein the weight ratio of the at least one polyalkylene glycol to the at least one lubricating oil base stock is from about 1:99 to about 6.5:93.5 
     
     
         17 . The method of  claim 13  wherein the weight ratio of the at least one polyalkylene glycol to the at least one lubricating oil base stock is from about 1:99 to about 4.5:95.5 
     
     
         18 . The method of  claim 13  wherein the at least one polyalkylene glycol comprises from about 25 to about 75 weight percent units derived from butylene oxide and from about 25 to about 75 weight percent units derived from propylene oxide, initiated by one or more initiators selected from monols, diols and polyols. 
     
     
         19 . The method of  claim 13  wherein the at least one polyalkylene glycol comprises from about 45 to about 55 weight percent units derived from butylene oxide and about 45 to about 55 weight percent units derived from propylene oxide, initiated by one or more monol initiators. 
     
     
         20 . The method of  claim 13  wherein the at least one polyalkylene glycol is selected from the group consisting of copolymers comprising units derived from propylene oxide and butylene oxide, polybutylene oxide homopolymer, and combinations thereof. 
     
     
         21 . The method of  claim 13  wherein the at least one polyalkylene glycol has a kinematic viscosity (KV 40 ) from about 15 to about 100 cSt at 40° C. as determined by ASTM D-445-19, and a molecular weight from about 400 to about 1100 grams/mole. 
     
     
         22 . The method of  claim 13  wherein the lubricating oil base stock comprises a Group I, Group II, Group III, Group IV or Group V base oil. 
     
     
         23 . The method of  claim 13  wherein the lubricating oil base stock is present in an amount of from about 75 weight percent to about 95 weight percent, and the at least one polyalkylene glycol is present in an amount from about 1 to about 7 weight percent, based on the total weight of the lubricating oil. 
     
     
         24 . The method of  claim 13  wherein the one or more lubricating oil additives further comprise one or more of an antiwear additive, viscosity modifier, antioxidant, detergent, dispersant, pour point depressant, corrosion inhibitor, metal deactivator, seal compatibility additive, antifoam agent, inhibitor, friction modifier, and anti-rust additive.