Functional fluid composition

Abstract

The fluid compositions of the present invention include an glycol component that includes a mixture of glycols according the formula: Wherein, typically, at least one of R 2 , R 3 , R 4 and R 5 is an alkyl group. The physical properties of the compositions include a high dry equilibrium reflux boiling point (ERBP), a high wet equilibrium reflux boiling point (WERBP), a low temperature viscosity or any combination thereof. These compositions are particularly useful because their physical properties (e.g., WERBP, ERBP, and low temperature viscosity) meet or exceed the provisions for DOT 3, 4, or 5 brake fluids.

1 . A functional fluid composition comprising:
 about 50 wt % to about 100 wt % of a glycol component wherein the glycol component includes one or more glycols of FORMULA I:   
     
       
         
         
             
             
         
       
       wherein R 1  and R 6  are H or an alkyl group containing 1 to 8 carbon atoms or mixtures thereof and n is at least 1, the glycol having n repeat units which may be the same or different, including at least one repeat unit wherein at least one of R 2 , R 3 , R 4 , and R 5  is an alkyl group containing 1 to 8 carbon atoms. 
     
   
   
       2 . A fluid composition of  claim 1  wherein the one or more glycols of FORMULA I is present at a concentration of at least 5 wt. %, based on the total weight of the glycol component. 
   
   
       3 . A fluid composition of  claim 1  wherein R 6  is H. 
   
   
       4 . A fluid composition of  claim 3  wherein exactly one of R 2 , R 3 , R 4 , and R 5  is an alkyl group containing 1 to 8 carbon atoms and the rest are H. 
   
   
       5 . A fluid composition of  claim 3  wherein at least two of R 2 , R 3 , R 4 , and R 5  are alkyl groups containing 1 to 8 carbon atoms and the rest are H. 
   
   
       6 . A fluid composition of  claim 3  wherein the glycol component further comprises at least one glycol of FORMULA III:
   R 1 O(CH 2 CH 2 O) n R 6    (FORMULA III)   wherein R 1  and R 6  are H or an alkyl group containing 1 to 8 carbon atoms or mixtures thereof and n is at least 1 (e.g., n is at least 3).   
   
   
       7 . A fluid composition of  claim 3  wherein the glycol of FORMULA I includes at least one first repeat unit wherein R 2 , R 3 , R 4 , and R 5  are each H and at least one second repeat unit wherein at least one (e.g., one, two, three or four) of R 2 , R 3 , R 4 , and R 5  are each an alkyl group containing 1 to 8 carbon atoms. 
   
   
       8 . A fluid composition of  claim 1  wherein the one or more glycols of FORMULA I includes a glycol of FORMULA IV:
   R 1 O(R 7 O) n H   (FORMULA IV)   where either (i) n is at least 1 and R 7  is all propyl groups, or (ii) n is at least 2 and R 7  is a mixture of ethyl and propyl groups.   
   
   
       9 . A fluid composition of  claim 1  wherein the glycol component includes an alkoxylated polypropylene glycol, an alkoxylated polyethylene-propylene glycol, or both. 
   
   
       10 . A fluid composition of  claim 1  wherein the glycol component includes alkoxylated glycols of FORMULA 1 and FORMULA III
   R 1 O(CH 2 CH 2 O) n R 6    (FORMULA III)   where at least one of R 1  and R 6  is an alkyl having from 1 to 8 carbon atoms, wherein the concentration of the alkoxylated glycols is greater than about 50 wt % based on the total weight of the glycol component.   
   
   
       11 . A fluid composition of  claim 10  wherein the composition is substantially free of glycol borate esters. 
   
   
       12 . A fluid composition of  claims 10  further comprising about 0.1 wt % to about 10 wt % of a glycol borate ester comprising the FORMULA V: 
     
       
         
         
             
             
         
       
       wherein each of R 1 , R 2 , R 3 , R 4 , and R 5  is H or an alkyl group containing 1 to 8 carbon atoms or mixtures thereof, n is 1 to 4; and about 0.3 wt % to about 10 wt % of an additive package including a corrosion inhibitor. 
     
   
   
       13 . A fluid composition in  claim 12  wherein an amount of the borate ester with n=3 is greater than about 90 wt % of the borate ester, an amount of the borate ester with n=2 is from about 0.5 wt % to about 5.0 wt % of the borate ester, and an amount of the borate ester with n=4 is from about 0 or 0.1 wt % to about 15 wt % of the borate ester. 
   
   
       14 . A fluid composition of  claim 10  wherein the composition has a dry equilibrium reflux boiling point of about 205° C. or more, a wet equilibrium reflux boiling point of about 140° C. or more, and a viscosity of about 1500 cSt or less at a temperature of about −40° C. 
   
   
       15 . A fluid composition  claim 10  wherein the composition includes an additives package which comprises an antioxidant, an anti-foaming agent, a corrosion inhibitor, a pH stabilizer, or any combination thereof. 
   
   
       16 . A fluid composition of  claim 10  wherein the glycol component comprises at least 50 wt % of alkoxylated glycols of FORMULA I and FORMULA III, wherein one of R 1  and R 6  is H and the other is selected from the group consisting of methyl, ethyl, propyl, butyl, or any combination thereof. 
   
   
       17 . A fluid composition of  claim 10  wherein the glycol component comprises at least 70 wt % of alkoxylated glycols of FORMULA I and FORMULA III, wherein one of R 1  and R 6  is H and the other is selected from the group consisting of methyl, ethyl, propyl, butyl, or any combination thereof. 
   
   
       18 . A fluid composition of  claim 17  wherein the glycol component is present at a concentration of at least 85 wt % based on the total weight of the fluid composition. 
   
   
       19 . A fluid composition of  claim 10  wherein the fluid composition is part of a braking system. 
   
   
       20 . A fluid composition of  claim 19  wherein the braking system is free of a booster pump. 
   
   
       21 . A functional fluid composition comprising:
 At least about 70 wt % of a glycol component wherein the glycol component includes   (i) one or more alkoxylated glycols of FORMULA I:   
     
       
         
         
             
             
         
       
       wherein R 6  is H, R 1  is an alkyl group containing 1 to 4 carbon atoms or mixtures thereof and n is at least 2, the glycol having n repeat units which may be the same or different, including at least one repeat unit wherein at least one of R 2 , R 3 , R 4 , and R 5  is a methyl group and the other are H, wherein the additional repeat units are the same as the first repeat unit, (CH 2 —CH 2 —O), or a combination, wherein the one or more alkoxylated glycols of FORMULA I is present at a concentration of at least 15 wt % based on the total weight of the glycol component; 
       (ii) optionally one or more alkoxylated glycols of FORMULA III:
   R 1 O(CH 2 CH 2 O) n R 6    (FORMULA III) 
 
       wherein R 6  is H, R 1  is an alkyl group containing 1 to 4 carbon atoms or mixtures thereof and n is at least 2; and 
       (iii) an additives package which comprises an antioxidant, an anti-foaming agent, a corrosion inhibitor, a pH stabilizer, or any combination thereof; 
       wherein the total of the alkoxylated glycols of FORMULA I and the alkoxylated glycols of FORMULA III are present at a concentration of at least 50 wt. % based on the total weight of the glycol component.