Low Viscosity Lubricating Oil Compositions With Increasing Flash Point

Abstract

This disclosure relates to a lubricating oil having a lubricating oil base stock as a major component, and one or more lubricating oil additives as a minor component. The lubricating oil base stock has at least one first ester that is partially esterified, and at least one second ester that is fully esterified. The lubricating oil has a flash point from about 125° C. to about 225° C. as determined by ASTM D-93, and a kinematic viscosity (KV 100 ) from about 1 to about 5 at 100° C. as determined by ASTM D-445. The at least one first ester and the at least one second ester are present in an amount such that, as the flash point of the lubricating oil is increased, the kinematic viscosity (KV 100 ) of the lubricating oil is decreased or maintained. This disclosure also relates to a method for increasing flash point, while decreasing or maintaining viscosity, of a lubricating oil in an engine or other mechanical component lubricated with the lubricating oil by using the lubricating oil.

1 . A composition comprising:
 at least one first ester that is partially esterified; and   at least one second ester that is fully esterified;   wherein the composition has a flash point from 125° C. to 225° C. as determined by ASTM D-93;   wherein the composition has a kinematic viscosity (KV 100 ) from 1 to 5 at 100° C. as determined by ASTM D-445; and   wherein the at least one first ester and the at least one second ester are present in an amount such that, as the flash point of said composition is increased, the kinematic viscosity (KV 100 ) of said composition is decreased or maintained.   
     
     
         2 . The composition of  claim 1  wherein the at least one first ester is present in an amount from 1 to 40 weight percent, based on the total weight of the composition; and the at least one second ester is present in an amount from 60 to 99 weight percent, based on the total weight of the composition. 
     
     
         3 . The composition of  claim 1  wherein the at least one first ester has a high hydroxyl content, and wherein the hydroxyl content is from 0.1 to 1 free hydroxyl group per molecule. 
     
     
         4 . The composition of  claim 1  wherein the at least one first ester comprises at least one partially esterified polyol ester of a monocarboxylic acid. 
     
     
         5 . The composition of  claim 1  wherein the at least one first ester is derived by reacting one or more polyhydric alcohols with one or more monocarboxylic acids; wherein the one or more polyhydric alcohols comprise neopentyl glycol, trimethylol ethane, 2-methyl-2-propyl-1,3-propanediol, trimethylol propane, pentaerythritol, dipentaerythritol, tripentaerythritol, or tetrapentaerythritol; and wherein the one or more monocarboxylic acids comprise acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, 3-methylbutanoic acid, 2-methylbutanoic acid, 2-ethylhexanoic acid, 2,4-dimethylpentanoic acid, 3,3,5-trimethylhexanoic acid, benzoic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachic acid, behenic acid, or oleic acid. 
     
     
         6 . The composition of  claim 1  wherein the at least one first ester comprises partially esterified neopentyl glycol sesquipelargonate, partially esterified trimethylolpropane pelargonate, partially esterified neopentyl glycol ester, partially esterified 2-methyl-2-propyl-1,3-propanediol ester, partially esterified trimethylol ethane ester, partially esterified trimethylol propane ester, partially esterified pentaerythritol ester, partially esterified dipentaerythritol ester, partially esterified tripentaerythrit 
     
     
         7 . The composition of  claim 1  wherein the at least one second ester is derived by reacting one or more monoalkanoic acids with one or more monoalkanols; where the one or more monoalkanoic acids comprise butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undeanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, and their isomers; and wherein the one or more monalkanols comprise butyl alcohol, pentyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, nonyl alcohol, decyl alcohol, dodecyl alcohol, tridecyl alcohol, tetradecyl alcohol, pentadecyl alcohol, hexadecyl alcohol, and their isomers. 
     
     
         8 . The composition of  claim 1  wherein the at least one second ester is derived by reacting one or more dibasic acids with one or more monoalkanols; wherein the one or more dibasic acids comprise phthalic acid, succinic acid, sebacic acid, fumaric acid, adipic acid, azelaic acid, linoleic acid dimer, malonic acid, alkyl malonic acid, or alkenyl malonic acid; and wherein the one or more monoalkanols comprise pentyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, nonyl alcohol, decyl alcohol, dodecyl alcohol, tridecyl alcohol, tetradecyl alcohol, pentadecyl alcohol, hexadecyl alcohol, and their isomers. 
     
     
         9 . The composition of  claim 1  wherein the at least one second ester comprises dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate, dieicosyl sebacate, tripropylene glycol dipelargonate, 2-ethylhexyl palmitate, octyl octanoate, or trimethyl-l-hexyl trimethylhexanoate. 
     
     
         10 . The composition of  claim 1  which has a flash point from 130° C. to 220° C. as determined by ASTM D-93, a viscosity (Kv 100 ) from 1 to 4 at 100° C. as determined by ASTM D-445, and a Noack volatility of no greater than 50 percent as determined by ASTM D-5800. 
     
     
         11 . The composition of  claim 1  which is a lubricating oil base stock. 
     
     
         12 . A lubricating oil comprising a lubricating oil base stock as a major component, and one or more lubricating oil additives as a minor component; wherein the lubricating oil base stock comprises:
 at least one first ester that is partially esterified; and   at least one second ester that is fully esterified;   wherein the lubricating oil has a flash point from 125° C. to 225° C. as determined by ASTM D-93;   wherein the lubricating oil has a kinematic viscosity (KV 100 ) from 1 to 5 at 100° C. as determined by ASTM D-445; and   wherein the at least one first ester and the at least one second ester are present in an amount such that, as the flash point of said lubricating oil is increased, the kinematic viscosity (KV 100 ) of said lubricating oil is decreased or maintained.   
     
     
         13 . A method for increasing flash point, while decreasing or maintaining viscosity, 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 comprising a lubricating oil base stock as a major component, and one or more lubricating oil additives as a minor component; wherein the lubricating oil base stock comprises:
 at least one first ester that is partially esterified; and   at least one second ester that is fully esterified;   wherein the lubricating oil has a flash point from 125° C. to 225° C. as determined by ASTM D-93;   wherein the lubricating oil has a kinematic viscosity (KV 100 ) from 1 to 5 at 100° C. as determined by ASTM D-445; and   wherein the at least one first ester and the at least one second ester are present in an amount such that, as the flash point of said lubricating oil is increased, the kinematic viscosity (KV 100 ) of said lubricating oil is decreased or maintained.   
     
     
         14 . A method for increasing flash point and thermal conductivity, while decreasing or maintaining viscosity, 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 comprising a lubricating oil base stock as a major component, and one or more lubricating oil additives as a minor component; 
       wherein the lubricating oil base stock comprises:
 at least one partially esterified ester; 
 wherein the lubricating oil has a flash point from 125° C. to 225° C. as determined by ASTM D-93; 
 wherein the lubricating oil has a kinematic viscosity (KV 100 ) from 1 to 5 at 100° C. as determined by ASTM D-445; and 
 wherein the lubricating oil has a thermal conductivity from 0.1 W/m.K to 0.2 W/m.K as determined by ASTM D-2717; 
 wherein the at least one partially esterified ester is present in an amount such that, as the flash point and thermal conductivity of said lubricating oil are increased, the kinematic viscosity (KV 100 ) of said lubricating oil is decreased or maintained.