Ionic liquids containing symmetric quaternary phosphonium cations and phosphorus-containing anions, and their use as lubricant additives

Patent metadata

Field	Value
Publication number	US-9957460-B2
Application number	US-201414184754-A
Country	US
Kind code	B2
Filing date	Feb 20, 2014
Priority date	Feb 20, 2014
Publication date	May 1, 2018
Grant date	May 1, 2018

Abstract

An ionic liquid composition having the following generic structural formula:

wherein R 1 , R 2 , R 3 , and R 4 are equivalent and selected from hydrocarbon groups containing at least three carbon atoms, and X − is a phosphorus-containing anion, particularly an organophosphate, organophosphonate, or organophosphinate anion, or a thio-substituted analog thereof containing hydrocarbon groups with at least three carbon atoms. Also described are lubricant compositions comprising the above ionic liquid and a base oil, wherein the ionic liquid is dissolved in the base oil. Further described are methods for applying the ionic liquid or lubricant composition onto a mechanical device for which lubrication is beneficial, with resulting improvement in friction reduction, wear rate, and/or corrosion inhibition.

First claim

What is claimed is:

1. A lubricant composition comprising:
(i) an ionic liquid having the following generic structural formula:

wherein R 1 , R 2 , R 3 , and R 4 are equivalent and selected from alkyl groups containing at least six carbon atoms, and X − is a phosphorus-containing anion having the following generic structural formula:

wherein R 5 and R 6 are independently selected from alkyl groups having at least four carbon atoms, wherein the alkyl groups are optionally substituted with one or more fluorine atoms, and R 5 and R 6 optionally interconnect to form a ring; and X 1 , X 2 , W, and Y are independently selected from O and S atoms; and
(ii) a base oil;
wherein said ionic liquid is dissolved in an amount of 2 to 10 wt % in said base oil.

2. The lubricant composition of claim 1 , wherein said base oil is a mechanical lubricating oil.

3. The lubricant composition of claim 1 , wherein said ionic liquid is included in said base oil in an amount of 2 to 5 wt %.

4. The lubricant composition of claim 1 , wherein R 1 , R 2 , R 3 , and R 4 are equivalent and selected from alkyl groups containing at least eight carbon atoms.

5. The lubricant composition of claim 1 , wherein said phosphorus-containing anion has the formula:

6. The lubricant composition of claim 1 , wherein R 5 and R 6 are alkyl groups containing at least six carbon atoms.

7. The lubricant composition of claim 1 , wherein R 5 and R 6 are branched alkyl groups.

8. The lubricant composition of claim 1 , wherein said lubricant composition further comprises a metal-containing anti-wear additive.

9. The lubricant composition of claim 8 , wherein said metal-containing anti-wear additive is a zinc dialkyldithiophosphate.

Assignees

• Ut Battelle Llc

Inventors

• Qu Jun
• Luo Huimin

Classifications

• C10N2030/08

  Resistance to extreme temperature · CPC title

• C10N2030/06

  Oiliness; Film-strength; Anti-wear; Resistance to extreme pressure · CPC title

• C10N2030/10

  Inhibition of oxidation, e.g. anti-oxidants · CPC title

• C10N2010/04

  Groups 2 or 12 · CPC title

• C10N2030/70

  Soluble oils · CPC title