Microencapsulated engine lubricant additives

Abstract

An engine lubricating system for an internal combustion engine. The system comprises a vehicle engine; a circulation system for providing a continuing flow of lubricant to the vehicle engine and engine components; and a lubricant disposed within the circulation system. The lubricant comprises a base oil and at least one microencapsulated oil additive. The microencapsulated oil additive is selectively released into the lubricant based one or more localized event. The localized event may include a predetermined temperature change, a predetermined pH change, a localized high friction contact, and combinations thereof.

What is claimed is: 
     
         1 . An engine lubricating system for an internal combustion engine, the system comprising:
 a vehicle engine;   a circulation system for providing a continuing flow of lubricant to the vehicle engine and engine components; and   a lubricant disposed within the circulation system, the lubricant comprising a base oil and at least one microencapsulated oil additive,   wherein the microencapsulated oil additive is selectively released into the lubricant based on one or more localized event.   
     
     
         2 . The system of  claim 1 , wherein the oil additive is selected from the group consisting of antioxidants, friction modifiers, dispersants, detergents, antifoam agents, aeration reducers, and combinations thereof. 
     
     
         3 . The system of  claim 1 , wherein the microencapsulated oil additive comprises an oil additive enclosed within a polymer coating selected from the group consisting of polyurethanes, polyureas, polyesters, polycyanoacrylates, phenol-formaldehyde, melamine-formaldehyde resins, and combinations thereof. 
     
     
         4 . The system of  claim 1 , wherein the microencapsulated oil additive has an average particle diameter size of less than about 10 μm. 
     
     
         5 . The system of  claim 1 , wherein the localized event comprises a predetermined change in temperature of the lubricant. 
     
     
         6 . The system of  claim 1 , wherein the localized event comprises a predetermined change in pH of the lubricant. 
     
     
         7 . The system of  claim 1 , wherein the localized event comprises a high friction contact between an engine component and the encapsulated oil additive disposed within the lubricant. 
     
     
         8 . The system of  claim 1 , wherein the microencapsulated oil additive is provided in an amount from about 10 wt % to about 15 wt % in excess of a theoretical amount of additive required for the expected life of the engine. 
     
     
         9 . An engine oil lubricant, comprising:
 a base oil; and   at least one microencapsulated oil additive,   wherein the microencapsulated oil additive is selectively released into the engine oil lubricant based on one or more localized event.   
     
     
         10 . The engine oil lubricant of  claim 9 , wherein the microencapsulated oil additive has an average particle diameter of less than about 10 μm. 
     
     
         11 . The engine oil lubricant of  claim 9 , wherein the oil additive is selected from the group consisting of antioxidants, friction modifiers, dispersants, detergents, antifoam agents, aeration reducers, and combinations thereof. 
     
     
         12 . The engine oil lubricant of  claim 9 , wherein the oil additive comprises a hindered phenolic antioxidant. 
     
     
         13 . The engine oil lubricant of  claim 9 , wherein the microencapsulated oil additive comprises an oil additive enclosed within a polymer coating selected from the group consisting of polyurethanes, polyureas, polyesters, polycyanoacrylates, phenol-formaldehyde, melamine-formaldehyde resins, and combinations thereof. 
     
     
         14 . The engine oil lubricant of  claim 13 , wherein the polymer coating degrades to fragments having an average particle size of less than about 1 μm after the localized event. 
     
     
         15 . The engine oil lubricant according to  claim 9 , wherein the selective release of the microencapsulated oil additive is based on a localized event selected from the group consisting of a predetermined temperature change, a predetermined pH change, a localized high friction contact, and combinations thereof. 
     
     
         16 . The system of  claim 9 , wherein the base oil comprises a mineral oil derived mixture. 
     
     
         17 . The system of  claim 9 , wherein the base oil comprises a synthetic ester derived mixture. 
     
     
         18 . A method of providing the controlled release of additives in engine oil lubricant circulating within an engine, the method comprising:
 providing a base engine oil including at least one microencapsulated oil additive; and   selectively releasing the microencapsulated oil additive into the engine oil lubricant based on one or more localized event within the engine.   
     
     
         19 . The method according to  claim 18 , wherein the localized event comprises at least one of a predetermined temperature change, a predetermined pH change, a localized high friction contact, and combinations thereof. 
     
     
         20 . The method according to  claim 18 , wherein the microencapsulated oil additive comprises an oil additive enclosed within a polymer coating selected from the group consisting of polyurethanes, polyureas, polyesters, polycyanoacrylates, phenol-formaldehyde, melamine-formaldehyde resins, and combinations thereof.