Method of limiting chemical degradation due to nitrogen dioxide contamination

Patent metadata

Field	Value
Publication number	US-12006486-B2
Application number	US-202218049730-A
Country	US
Kind code	B2
Filing date	Oct 26, 2022
Priority date	Oct 29, 2021
Publication date	Jun 11, 2024
Grant date	Jun 11, 2024

Abstract

A method of limiting the chemical degradation of hydrocarbonaceous liquids due to nitrogen dioxide contamination at elevated temperature comprises the addition thereto of an ionic liquid composed of a cation and a boron- and halogen-free, multi-functional aromatic anion, the ionic liquid serving to inhibit the nitration of hydrocarbonaceous liquid components that initiates degradation.

First claim

What is claimed is:

1. A method of limiting the chemical degradation of a hydrocarbonaceous liquid in service at bulk liquid temperatures of from 60 to 180° C., the degradation being initiated by nitration of the liquid resulting from contamination with nitrogen dioxide in service, comprising:
preparing, or obtaining a freshly prepared, hydrocarbonaceous liquid suitable for service at bulk liquid temperatures of from 60 to 180° C. and being free of aged components and nitrogen dioxide contamination;

adding to said hydrocarbonaceous liquid, prior to service at bulk liquid temperatures of from 60 to 180° C., an ionic liquid comprising:
(i) one or more organic cations each comprising a tetra-alkyl substituted phosphonium cation, and
(ii) one or more halogen- and boron-free organic anions each comprising an aromatic ring bearing at least two substituent functional groups containing heteroatoms, these functional groups being conjugated with the aromatic ring, and this conjugated system bearing the anionic charge;
wherein the one or more anions (ii) of the ionic liquid are one or more alkyl-substituted salicylate anions, and wherein the alkyl substituent(s) of each anion are independently selected from alkyl groups containing from 12 to 24 carbon atoms;

wherein the ionic liquid is added in an amount of 0.1 to 5.0% by weight, per weight of hydrocarbonaceous liquid to thereafter inhibit the nitration of the hydrocarbonaceous liquid in service at bulk liquid temperatures of from 60 to 180° C., in the presence of nitrogen dioxide contamination; and
putting said hydrocarbonaceous liquid into service, wherein the ionic liquid thereby limits the resulting chemical degradation of the liquid.

2. The method of claim 1 , wherein the chemical degradation is that resulting from the decomposition of hydrocarbonaceous nitrate esters formed in service by the nitration of the hydrocarbonaceous liquid by nitrogen dioxide at bulk liquid temperatures of from 60 to 180° C.; and wherein the ionic liquid is added in an amount determined to inhibit the formation of hydrocarbonaceous nitrate esters in that service.

3. The method of claim 2 , wherein the decomposition of the hydrocarbonaceous nitrate esters results from the hydrocarbonaceous liquid being periodically or continuously subjected in service to bulk liquid temperatures of from 110 to 160° C.; and wherein the ionic liquid is added in an amount determined to inhibit the formation of hydrocarbonaceous nitrate esters in that service.

4. The method of claim 2 , wherein the amount of reduction or limitation of nitrate ester formation in a lubricating oil composition is determined by the observance of at least a 10% a lower nitrate ester peak height in the presence of the lubricating oil composition containing ionic liquid as compared to the nitrate ester peak of the same lubricating oil composition where the ionic liquid is replaced with an ionic liquid having the same cation, but hexanoate as the anion in the same proportions, as measured by infrared spectroscopy according to ASTM D8048-20, under like conditions of service and nitrogen dioxide contamination.

5. The method of claim 1 , wherein each cation (i) of the ionic liquid is nitrogen-free.

6. The method of claim 1 , wherein each anion (ii) of the ionic liquid is nitrogen-free.

7. The method of claim 1 , wherein each anion (ii) of the ionic liquid is sulfur-free.

8. The method of claim 1 , wherein each cation (i) of the ionic liquid is a trihexyltetradecyl-phosphonium cation.

9. The method of claim 1 , wherein the hydrocarbonaceous liquid is a lubricating oil for a mechanical device.

10. The method of claim 1 , wherein the hydrocarbonaceous liquid is a crankcase lubricating oil for an internal combustion engine, and is subjected in service to nitrogen dioxide contamination originating from exhaust gas and periodically or continuously to bulk liquid temperatures in the crankcase of between 110 and 160° C.

11. The method of claim 1 , wherein the amount of ionic liquid added to the hydrocarbonaceous liquid to is in the range of 1.0 to 3.0% by weight, per weight of hydrocarbonaceous liquid.

12. A nitration-resistant hydrocarbonaceous liquid obtained or obtainable by the method of claim 1 .

13. An additive concentrate composition for a hydrocarbonaceous liquid, comprising an ionic liquid composed of:
(i) one or more organic cations each comprising a tetra-alkyl substituted phosphonium cation, and
(ii) one or more halogen- and boron-free organic anions each comprising an aromatic ring bearing at least two substituent functional groups containing heteroatoms, these functional groups being conjugated with the aromatic ring and this conjugated system bearing the anionic charge;
wherein the one or more anions (ii) of the ionic liquid are one or more alkyl-substituted salicylate anions, and wherein the alkyl substituent(s) of each anion are independently selected from alkyl groups containing from 12 to 24 carbon atoms;

the concentrate further comprising a carrier liquid and, optionally, further additives; and
wherein the additive concentrate composition includes from 5 to 25% by weight of the ionic liquid, per weight of the additive concentrate composition.

14. The additive concentrate of claim 13 , comprising the ionic liquid of claim 1 .

15. The additive concentrate of claim 13 , further comprising one or more phosphorus-containing compounds; dispersants; metal detergents; anti-wear agents; friction modifiers, viscosity modifiers; and/or antioxidants provided they are different from the ionic liquid.

16. The additive concentrate of claim 15 , wherein the metal detergents comprise a combination of one or more magnesium sulfonate or magnesium salicylate detergents and one or more calcium salicylate or calcium sulfonate detergents.

17. The additive concentrate of claim 15 , further comprising one or more dihydrocarbyl dithiophosphate metal salts.

Assignees

• Infineum Int Ltd

Inventors

• Coultas David Robert
• Irving Matthew David
• Hollingsworth Nathan
• Greer Adam
• Hardacre Christopher

Classifications

• C10N2040/25

  Internal-combustion engines · CPC title

• C10M2223/065

  containing sulfur · CPC title

• C10M2215/22

  Heterocyclic nitrogen compounds · CPC title

• C10M133/38

  Heterocyclic nitrogen compounds · CPC title

• C10N2070/02

  Concentrating of additives · CPC title