Method for improving high temperature antifoaming performance of a lubricating oil

Abstract

This disclosure provides a method for improving high temperature antifoaming performance of a lubricating oil in an engine or other mechanical component lubricated with the lubricating oil by using as the lubricating oil a formulated oil. The formulated oil has a composition with a lubricating oil base stock as a major component, and at least one silicone antifoaming agent, as a minor component. The silicone antifoaming agent is delivered to the lubricating oil by contacting the lubricating oil with a cured silicone (e.g., room temperature vulcanized (RTV) silicone) at a temperature, and for a period of time, sufficient to deliver silicone to the lubricating oil. The delivered silicone is soluble in the lubricating oil. The lubricating oils are useful as passenger vehicle engine oils (PVEO) and commercial vehicle engine oils (CVEO).

1 . A method for delivering a silicone antifoaming agent to a lubricating oil, said method comprising contacting the lubricating oil with a cured silicone at a temperature, and for a period of time, sufficient to deliver silicone to the lubricating oil; wherein the delivered silicone is soluble in the lubricating oil. 
     
     
         2 . The method of  claim 1  wherein, in an engine or other mechanical component lubricated with the lubricating oil, high temperature antifoaming performance is improved as compared to high temperature antifoaming performance achieved using a lubricating oil containing a silicone antifoaming agent delivered from uncured silicone, as determined by ASTM D6082 or ASTM D892 Sequence II. 
     
     
         3 . The method of  claim 1  wherein the cured silicone comprises room temperature vulcanized (RTV) silicone. 
     
     
         4 . The method of  claim 1  wherein the temperature is from 10° C. to 30° C., and the period of time is from 1 hour to 240 hours. 
     
     
         5 . The method of  claim 1  wherein the room temperature vulcanized (RTV) silicone comprises low molecular weight leachates. 
     
     
         6 . The method of  claim 5  wherein the low molecular weight leachates exhibit a bimodal molecular weight distribution, as determined by gel permeation chromatography (GPC). 
     
     
         7 . The method of  claim 1  wherein the lubricating oil comprises a Group I, Group II, Group III, Group IV or Group V base oil. 
     
     
         8 . The method of  claim 1  wherein the at least one silicone antifoaming agent is present in an amount greater than 5 parts per million (ppm). 
     
     
         9 . The method of  claim 1  wherein the lubricating oil further comprises one or more of an antiwear additive, viscosity modifier, antioxidant, detergent, dispersant, pour point depressant, metal deactivator, seal compatibility additive, inhibitor, and anti-rust additive. 
     
     
         10 . A method for improving high temperature antifoaming performance of a lubricating oil in an engine or other mechanical component lubricated with the lubricating oil by using as the lubricating oil a formulated oil, said formulated oil having a composition comprising a lubricating oil base stock as a major component; and at least one silicone antifoaming agent, as a minor component; wherein the silicone antifoaming agent is delivered to the lubricating oil by contacting the lubricating oil with a cured silicone at a temperature, and for a period of time, sufficient to deliver silicone to the lubricating oil; wherein the delivered silicone is soluble in the lubricating oil; and wherein high temperature antifoaming performance is improved as compared to high temperature antifoaming performance achieved using a lubricating oil containing a silicone antifoaming agent delivered from uncured silicone, as determined by ASTM D6082 or ASTM D892 Sequence II. 
     
     
         11 . The method of  claim 10  wherein the cured silicone comprises room temperature vulcanized (RTV) silicone. 
     
     
         12 . The method of  claim 10  wherein the temperature is from 10° C. to 30° C., and the period of time is from 1 hour to 240 hours. 
     
     
         13 . The method of  claim 10  wherein the room temperature vulcanized (RTV) silicone comprises low molecular weight leachates. 
     
     
         14 . The method of  claim 13  wherein the low molecular weight leachates exhibit a bimodal molecular weight distribution, as determined by gel permeation chromatography (GPC). 
     
     
         15 . The method of  claim 10  wherein the lubricating oil base stock comprises a Group I, Group II, Group III, Group IV or Group V base oil. 
     
     
         16 . The method of  claim 10  wherein the at least one silicone antifoaming agent is present in an amount greater than 5 parts per million (ppm). 
     
     
         17 . The method of  claim 10  wherein the lubricating oil base stock is present in an amount of from 50 weight percent to 95 weight percent, based on the total weight of the formulated oil. 
     
     
         18 . The method of  claim 10  wherein the formulated oil further comprises one or more of an antiwear additive, viscosity modifier, antioxidant, detergent, dispersant, pour point depressant, metal deactivator, seal compatibility additive, inhibitor, and anti-rust additive. 
     
     
         19 . A process for preparing a lubricating oil having a silicone antifoaming agent, said process comprising contacting the lubricating oil with a cured silicone at a temperature, and for a period of time, sufficient to deliver silicone in the lubricating oil; wherein the delivered silicone is soluble in the lubricating oil. 
     
     
         20 . The process of  claim 19  wherein the cured silicone comprises room temperature vulcanized (RTV) silicone. 
     
     
         21 . The process of  claim 19  wherein the temperature is from 10° C. to 30° C., and the period of time is from 1 hour to 240 hours. 
     
     
         22 . The process of  claim 19  wherein the room temperature vulcanized (RTV) silicone comprises low molecular weight leachates. 
     
     
         23 . The process of  claim 22  wherein the low molecular weight leachates exhibit a bimodal molecular weight distribution, as determined by gel permeation chromatography (GPC). 
     
     
         24 . The process of  claim 19  wherein, in an engine or other mechanical component lubricated with the lubricating oil, high temperature antifoaming performance is improved as compared to high temperature antifoaming performance achieved using a lubricating oil containing a silicone antifoaming agent delivered from uncured silicone, as determined by ASTM D6082 or ASTM D892 Sequence II. 
     
     
         25 . The process of  claim 19  wherein the lubricating oil comprises a Group I, Group II, Group III, Group IV or Group V base oil. 
     
     
         26 . The process of  claim 19  wherein the at least one silicone antifoaming agent is present in an amount greater than 5 parts per million (ppm). 
     
     
         27 . The process of  claim 19  wherein the lubricating oil further comprises one or more of an antiwear additive, viscosity modifier, antioxidant, detergent, dispersant, pour point depressant, metal deactivator, seal compatibility additive, inhibitor, and anti-rust additive. 
     
     
         28 . A lubricating oil having a composition comprising a lubricating oil base stock as a major component; and at least one silicone antifoaming agent as a minor component; wherein the silicone antifoaming agent is delivered to the lubricating oil by contacting the lubricating oil with a cured silicone at a temperature, and for a period of time, sufficient to deliver silicone to the lubricating oil; and wherein the delivered silicone is soluble in the lubricating oil. 
     
     
         29 . The lubricating oil of  claim 28  wherein, in an engine or other mechanical component lubricated with the lubricating oil, high temperature antifoaming performance is improved as compared to high temperature antifoaming performance achieved using a lubricating oil containing a silicone antifoaming agent delivered from uncured silicone, as determined by ASTM D6082 or ASTM D892 Sequence II. 
     
     
         30 . The lubricating oil of  claim 28  wherein the cured silicone comprises room temperature vulcanized (RTV) silicone. 
     
     
         31 . The lubricating oil of  claim 28  wherein the temperature is from 10° C. to 30° C., and the period of time is from 1 hour to 240 hours. 
     
     
         32 . The lubricating oil of  claim 28  wherein the room temperature vulcanized (RTV) silicone comprises low molecular weight lea   
     
     
         33 . The lubricating oil of  claim 32  wherein the low molecular weight leachates exhibit a bimodal molecular weight distribution, as determined by gel permeation chromatography (GPC). 
     
     
         34 . The lubricating oil of  claim 28  wherein the lubricating oil base stock comprises a Group I, Group II, Group III, Group IV or Group V base oil. 
     
     
         35 . The lubricating oil of  claim 28  wherein the at least one silicone antifoaming agent is present in an amount greater than 5 parts per million (ppm). 
     
     
         36 . The lubricating oil of  claim 28  wherein the lubricating oil base stock is present in an amount of from 50 weight percent to 95 weight percent, based on the total weight of the formulated oil. 
     
     
         37 . The lubricating oil of  claim 28  wherein the formulated oil further comprises one or more of an antiwear additive, viscosity modifier, antioxidant, detergent, dispersant, pour point depressant, metal deactivator, seal compatibility additive, inhibitor, and anti-rust additive. 
     
     
         38 . The lubricating oil of  claim 28  which is a passenger vehicle engine oil (PVEO) or a commercial vehicle engine oil (CVEO). 
     
     
         39 . A lubricating oil having a composition comprising a lubricating oil base stock as a major component; and at least one silicone antifoaming agent as a minor component; wherein said lubricating oil is prepared by a process that comprises contacting the lubricating oil with a cured silicone at a temperature, and for a period of time, sufficient to deliver silicone in the lubricating oil; wherein the delivered silicone is soluble in the lubricating oil. 
     
     
         40 . The lubricating oil of  claim 39  wherein the cured silicone comprises room temperature vulcanized (RTV) silicone. 
     
     
         41 . The lubricating oil of  claim 39  wherein the temperature is from 10° C. to 30° C., and the period of time is from 1 hour to 240 hours. 
     
     
         42 . The lubricating oil of  claim 39  wherein the room temperature vulcanized (RTV) silicone comprises low molecular weight leachates. 
     
     
         43 . The lubricating oil of  claim 42  wherein the low molecular weight leachates exhibit a bimodal molecular weight distribution, as    
     
     
         44 . The lubricating oil of  claim 39  wherein, in an engine or other mechanical component lubricated with the lubricating oil, high temperature antifoaming performance is improved as compared to high temperature antifoaming performance achieved using a lubricating oil containing a silicone antifoaming agent delivered from uncured silicone, as determined by ASTM D6082 or ASTM D892 Sequence II. 
     
     
         45 . The lubricating oil of  claim 39  wherein the lubricating oil base stock comprises a Group I, Group II, Group III, Group IV or Group V base oil. 
     
     
         46 . The lubricating oil of  claim 39  wherein the at least one silicone antifoaming agent is present in an amount greater than 5 parts per million (ppm). 
     
     
         47 . The lubricating oil of  claim 39  which further comprises one or more of an antiwear additive, viscosity modifier, antioxidant, detergent, dispersant, pour point depressant, metal deactivator, seal compatibility additive, inhibitor, and anti-rust additive.