Method of making a chemically active filter element for an oil filter

Abstract

An improved oil filter, for use with an internal combustion engine, comprises a hollow filter housing defining a chamber therein and having an inlet and an outlet with a flow path therebetween; a mechanically active filter member disposed inside the filter housing in the flow path; and a chemically active filter member disposed inside the filter housing in the flow path. The chemically active filter member comprises a plurality of composite oil additive pellets. The plurality of pellets is interconnected to form a substantially integral permeable member, and the substantially integral permeable member is impregnated with an alkaline composition. The alkaline composition is provided to counteract acidic combustion products in lubricating oil in an internal combustion engine.

What is claimed is: 
     
         1 . A method of making a chemically active filter element for an oil filter, the method comprising the steps of:
 interconnecting a plurality of composite oil additive pellets with a binder to form a substantially integral permeable member; and   impregnating the substantially integral permeable member with an alkaline composition by infusing the additive pellets with the alkaline composition until a desired loading of the additive pellets is achieved.   
     
     
         2 . The method of  claim 1 , wherein the alkaline composition comprises at least one alkaline agent selected from the group consisting of lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, francium hydroxide, beryllium hydroxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, and radium hydroxide, and mixtures thereof. 
     
     
         3 . The method of  claim 1 , further including the step of removing excess alkaline composition, if present, from the additive pellets. 
     
     
         4 . The method of  claim 1 , wherein the additive pellets are impregnated with the alkaline composition by depositing the additive pellets in a vessel that is filled with an aqueous solution of the alkaline composition. 
     
     
         5 . The method of  claim 1 , wherein the additive pellets are impregnated with alkaline composition by depositing the additive pellets in a porous vessel that is dipped into an aqueous solution of the alkaline composition. 
     
     
         6 . The method of  claim 1 , wherein the additive pellets are impregnated with the alkaline composition by depositing the additive pellets in a rotary vessel that is heated with an inert gas of the alkaline composition and purged. 
     
     
         7 . The method of  claim 1 , wherein the desired loading of the additive pellets is a uniform loading of the alkaline composition in a predetermined quantity to a predetermined depth of penetration. 
     
     
         8 . The method of  claim 1 , wherein a degassing technique is used to facilitate the impregnating step. 
     
     
         9 . The method of  claim 1 , wherein the additive pellets comprise a silicon component that substantially immobilizes the alkaline composition during the impregnating step by chemically reacting the alkaline composition to form an oil insoluble silicate. 
     
     
         10 . The method of  claim 1 , further comprising the step of coating at least a portion of a surface of the substantially integral permeable member with a barrier material that renders the additive pellets substantially impermeable with respect to carbon dioxide and moisture. 
     
     
         11 . The method of  claim 10 , wherein the step of coating at least a portion of the surface of the substantially integral permeable member with a barrier material comprises applying a liquid melt of the barrier material to the substantially integral permeable member. 
     
     
         12 . The method of  claim 10 , wherein the step of coating at least a portion of the surface of the substantially integral permeable member with a barrier material comprises applying an aqueous solution of the barrier material to the substantially integral permeable member. 
     
     
         13 . A method of making an oil filter, the method comprising the steps of:
 providing a hollow filter housing defining a chamber therein, the filter housing having an inlet and an outlet with a flow path therebetween;   inserting a mechanically active filter member within the filter housing in the flow path; and   inserting a chemically active filter member within the filter housing in the flow path, wherein the chemically active filter member is formed by a method comprising the steps of:
 interconnecting a plurality of composite oil additive pellets with a binder to form a substantially integral permeable member; and 
 impregnating the substantially integral permeable member with an alkaline composition by infusing the additive pellets with the alkaline composition until a desired loading of the additive pellets is achieved. 
   
     
     
         14 . The method of  claim 13 , wherein the composite oil additive pellets are formed of at least a basic conditioner and binder. 
     
     
         15 . The method of  claim 14 , wherein the composite oil additive pellets are further formed of at least one or more of a corrosion inhibitor, a metal deactivator, an antioxidant, a dispersant, a friction modifier, an oil stabilizer, a pour point depressant, a detergent, a viscosity index improver, an anti-wear agent, an extreme pressure additive, and mixtures thereof. 
     
     
         16 . The method of  claim 13 , wherein the alkaline composition comprises at least one alkaline agent selected from the group consisting of lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, francium hydroxide, beryllium hydroxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, and radium hydroxide, and mixtures thereof. 
     
     
         17 . The method of  claim 13 , wherein the additive pellets are impregnated with the alkaline composition by depositing the additive pellets in a vessel that is filled with an aqueous solution of the alkaline composition. 
     
     
         18 . The method of  claim 13 , wherein the additive pellets are impregnated with alkaline composition by depositing the additive pellets in a porous vessel that is dipped into an aqueous solution of the alkaline composition. 
     
     
         19 . The method of  claim 13 , wherein the additive pellets are impregnated with the alkaline composition by depositing the additive pellets in a rotary vessel that is heated with an inert gas of the alkaline composition and purged. 
     
     
         20 . The method of  claim 13 , wherein the desired loading of the additive pellets is a uniform loading of the alkaline composition in a predetermined quantity to a predetermined depth of penetration.