Controlled Rellease of oxygen scavengers in cooling systems

Abstract

Provided are compositions and methods for releasing oxygen scavengers into a coolant. The compositions include a controlled release component and an oxygen scavenger component which includes at least one oxygen scavenger. Methods and devices for releasing oxygen scavengers into a coolant are also provided.

What is claimed is:  
     
         1 . A coolant additive composition comprising: 
 a controlled release component and an oxygen scavenger component wherein the controlled release component is effective to reduce the rate of release of the oxygen scavenger component into a coolant in a cooling system.    
     
     
         2 . The additive composition of  claim 1  wherein the oxygen scavenger component is not effective to form a protective complex with metal.  
     
     
         3 . The additive composition of  claim 1  wherein the rate of release is reduced relative to an identical composition without the controlled release component.  
     
     
         4 . The additive composition of  claim 1  wherein the oxygen scavenger component is effective to inhibit oxidative degradation of the coolant when the oxygen scavenger component is released into the coolant.  
     
     
         5 . The additive composition of  claim 1  wherein the cooling system is a circulating cooling system.  
     
     
         6 . The additive composition of  claim 5  wherein the circulating cooling system is not completely closed.  
     
     
         7 . The additive composition of  claim 1  wherein the cooling system cools an internal combustion engine.  
     
     
         8 . The additive composition of  claim 1  wherein the oxygen scavenger component is selected from the group consisting of thiosulfite, thiosulfate, mercaptopropionic acid, bisulfite, hydrosulfite, dithionate, hyposulfite, sulfite, sulfide, stannous, hydroxylamine and hydrazine or mixtures thereof.  
     
     
         9 . The additive composition of  claim 1  wherein the coolant is glycol-based.  
     
     
         10 . The additive composition of  claim 1  wherein the controlled release component is partially soluble in the coolant.  
     
     
         11 . The additive composition of  claim 1  wherein the controlled release component includes a matrix material.  
     
     
         12 . The additive composition of  claim 1  wherein the controlled release component includes a coating material.  
     
     
         13 . The additive composition of  claim 1  wherein the controlled release component includes both a matrix material and a coating material.  
     
     
         14 . A method of producing a coolant additive composition, comprising the step of: 
 combining an oxygen scavenger component with a matrix material to form a mixture wherein the matrix material is effective to reduce a rate of release of the oxygen scavenger component into a coolant in a cooling system.    
     
     
         15 . The method of  claim 14  wherein the rate of release of the oxygen scavenger component into the cooling system is reduced relative to an identical additive composition without the matrix material.  
     
     
         16 . The method of  claim 14  wherein the oxygen scavenger component is effective to inhibit oxidative degradation of the coolant when the oxygen scavenger component is released into the coolant.  
     
     
         17 . The method of  claim 14  wherein the matrix material comprises a polymeric material.  
     
     
         18 . The method of  claim 14  which further comprises providing a coating material, the coating material being effective to reduce the rate of release of the oxygen scavenger component into the coolant relative to an identical oxygen scavenger component without the provided coating material.  
     
     
         19 . The additive composition of  claim 14  wherein the oxygen scavenger component is selected from the group consisting of thiosulfite, thiosulfate, mercaptopropionic acid, bisulfite, hydrosulfite, dithionate, hyposulfite, sulfite, sulfide, stannous, hydroxylamine and hydrazine or mixtures thereof.  
     
     
         20 . The method of  claim 14  wherein the cooling system cools an internal combustion engine.  
     
     
         21 . A method of producing an additive composition comprising the steps of: 
 providing a coolant additive composition which includes an oxygen scavenger component; and    providing a coating material on the additive composition to form a coated additive composition, the coating material being partially coolant soluble and effective, when the coated additive composition is contacted with a coolant, to reduce the rate of release of the additive composition into a coolant in a cooling system.    
     
     
         22 . The method of  claim 21  wherein the rate of release of the additive composition is reduced relative to an identical additive composition without the coating material.  
     
     
         23 . The method of  claim 21  wherein the oxygen scavenger component is effective to inhibit oxidative degradation of the coolant when the oxygen scavenger component is released into the coolant.  
     
     
         24 . The additive composition of  claim 21  wherein the oxygen scavenger component is selected from the group consisting of thiosulfite, thiosulfate, mercaptopropionic acid, bisulfite, hydrosulfite, dithionate, hyposulfite, sulfite, sulfide, stannous, hydroxylamine and hydrazine or mixtures thereof.  
     
     
         25 . The additive composition of  claim 21  wherein the cooling system cools an internal combustion engine.  
     
     
         26 . A coolant additive assembly comprising: 
 a housing including a coolant inlet and a coolant outlet; and    an additive composition disposed within the housing including a controlled release component and an oxygen scavenger component wherein the controlled release component is effective to reduce the rate of release of the oxygen scavenger component into a coolant in a cooling system.    
     
     
         27 . The additive assembly of  claim 26  wherein the rate of release of the oxygen scavenger component into the coolant is reduced relative to an identical additive composition without the controlled release component.  
     
     
         28 . The additive assembly of  claim 26  wherein the controlled release component is partially soluble in the coolant.  
     
     
         29 . The additive assembly of  claim 26  wherein the oxygen scavenger component is effective to inhibit oxidative degradation of the coolant when the oxygen scavenger component is released into the coolant.  
     
     
         30 . The additive assembly of  claim 26  wherein the controlled release component comprises a coating on the oxygen scavenger component.  
     
     
         31 . The additive assembly of  claim 26  wherein the controlled release component comprises a matrix material.  
     
     
         32 . The additive assembly of  claim 31  wherein the matrix material comprises a polymeric material and is substantially coolant insoluble or is partially coolant soluble.  
     
     
         33 . The additive assembly of  claim 26  wherein the controlled release component comprises a coating on the oxygen scavenger component and a matrix material.  
     
     
         34 . The additive composition of  claim 26  wherein the oxygen scavenger component is selected from the group consisting of thiosulfite, thiosulfate, mercaptopropionic acid, bisulfite, hydrosulfite, dithionate, hyposulfite, sulfite, sulfide, stannous, hydroxylamine and hydrazine or mixtures thereof.  
     
     
         35 . The additive composition of  claim 26  wherein the cooling system cools an internal combustion engine.  
     
     
         36 . A method for releasing an oxygen scavenger component into a coolant comprising contacting the additive composition of  claim 1  with a coolant.  
     
     
         37 . The method of  claim 36  wherein the oxygen scavenger removes molecular oxygen from the coolant.  
     
     
         38 . A method for releasing an oxygen scavenger component into a coolant comprising contacting the additive composition produced by the method of  claim 14  with a coolant.  
     
     
         39 . A method for releasing an oxygen scavenger component into a coolant comprising contacting the additive composition produced by the method of  claim 21  with a coolant.  
     
     
         40 . A method for releasing an oxygen scavenger component into a coolant comprising contacting an additive composition included in an assembly of  claim 26  with a coolant.