KR-20260068096-A - Improved lubricating fluid and novel sulfur-containing functional additive

KR20260068096AKR 20260068096 AKR20260068096 AKR 20260068096AKR-20260068096-A

Abstract

The present invention relates to a lubricating fluid comprising water, one or more oil(s), and one of homocysteine or a derivative thereof having extreme pressure and/or wear resistance and/or anti-biofilm properties. The present invention also relates to the use of one of homocysteine or a derivative thereof in lubricating fluids, particularly semi-synthetic fluids. Finally, the present invention relates to a method for lubricating a metal or composite, comprising contacting said metal or said composite with a lubricating fluid comprising water, one or more oil(s), and one of homocysteine or a derivative thereof.

Inventors

렉, 장-크리스토프
생-루이-오귀스탱, 파스칼
에디제, 엘렌

Assignees

아르끄마 프랑스

Dates

Publication Date: 20260513
Application Date: 20240906
Priority Date: 20230908

Claims (12)

As a lubricating fluid, a) One of the sulfur-containing compounds of the following general formula (I), or salts thereof: R 3 -X-CH(NR 1 R 2 )-(CH 2 ) n -(S) p -Z (I) [In the above formula, - Z is a hydrogen atom or a -( CH₂ ) n -CH ( NR₁R₂ ) -XR₃ group; - R1 and R2 are identical or different and are selected from saturated or unsaturated, linear, branched or cyclic, aromatic or non-aromatic hydrocarbon chains that may include a hydrogen atom, or one or more heteroatom(s) having 1 to 20 carbon atoms; - X is selected from -C(=O)-, -CH 2 - or -CN; - R 3 is, (i) If X represents -CN, it does not exist, or (ii) hydrogen atoms, or (iii) -OR a , where R a is a hydrogen atom, or a saturated or unsaturated, linear, branched or cyclic, aromatic or non-aromatic hydrocarbon chain having 1 to 20 carbon atoms and may contain one or more heteroatom(s), or (iv) -NR b R c , where R b and R c are the same or different, selected from saturated or unsaturated, linear, branched or cyclic, aromatic or non-aromatic hydrocarbon chains that may include hydrogen atoms, or one or more heteroatom(s) having 1 to 20 carbon atoms, and - n is an integer equal to 2, and - p is an integer from 1 to 8; [However, if Z is a hydrogen atom, p is 1]; b) water; c) one or more oil(s); d) one or more emulsifier(s); and e) A lubricating fluid comprising, optionally, one or more functional additive(s).
In paragraph 1, Lubricating fluid in which the above sulfur-containing compound is one of the following general formula (Ia) or a salt thereof: R 3 -X-CH(NR 1 R 2 )-(CH 2 ) n -SH (Ia) [In the above formula, R1 , R2 , R3 , X, and n are as defined in the first term].
In paragraph 1, A lubricating fluid in which the compound of the above general formula (I) is selected from the group consisting of homocysteine, homocystine, dihomocysteine trisulfide, dihomocysteine tetrasulfide, dihomocysteine pentasulfide and salts thereof, preferably homocysteine.
In any one of paragraphs 1 through 3, A lubricating fluid in which the amount of a sulfur-containing compound of general formula (I) is 0.1 wt% to 30 wt%, preferably 0.1 wt% to 20 wt%, more preferably 1 wt% to 7 wt% with respect to the total weight of the fluid.
In any one of paragraphs 1 through 4, A lubricating fluid in which the amount of water is 5% to 95% by weight, preferably 55% to 80% by weight, relative to the total weight of the fluid.
In any one of paragraphs 1 through 5, A lubricating fluid in which the total amount of oil(s) is 1% to 50% by weight, preferably 5% to 30% by weight, relative to the total weight of the fluid.
In any one of paragraphs 1 through 6, A lubricating fluid in which the above emulsifier(s) are selected from the group consisting of alkoxylated alcohols, fatty acids, sulfonic acids, alkali metal sulfonates, fatty amides, polyethylene glycol esters, and mixtures thereof.
In any one of paragraphs 1 through 7, A lubricating fluid in which the total amount of emulsifier(s) is 1% to 40% by weight, preferably 1% to 30% by weight, with respect to the total weight of the fluid.
Use of a lubricating fluid defined in any one of paragraphs 1 through 8 as a hydraulic fluid for lubrication and/or cleaning of mechanical devices, for metalworking, or also as a mining fluid.
Use as an anti-wear and/or extreme pressure and/or anti-biofilm additive in a lubricating fluid as defined in any one of claims 1 to 8, wherein one of a sulfur-containing compound of general formula (I) defined in any one of claims 1 to 3 or a salt thereof.
In Paragraph 10, The above sulfur-containing compound is selected from the group consisting of homocysteine, homocystine, dihomocysteine trisulfide, dihomocysteine tetrasulfide, dihomocysteine pentasulfide, and salts thereof, preferably homocysteine.
A method for lubricating a metal or composite material, comprising the step of contacting the metal or composite material with a lubricating fluid defined in any one of claims 1 to 8.

Description

Improved lubricating fluid and novel sulfur-containing functional additive The present invention relates to a lubricating fluid, particularly a semi-synthetic fluid, comprising a novel sulfur-containing additive having extreme pressure and/or wear resistance and/or anti-biofilm properties. The present invention also relates to the use of such novel sulfur-containing additive in a lubricating fluid, particularly a semi-synthetic fluid. Finally, the present invention relates to a method for lubricating a metal or a composite, comprising contacting the metal or the composite with the lubricating fluid comprising the sulfur-containing additive. It is known that fluids or greases are used to lubricate mechanical systems in a great many industrial processes. These lubricating compositions limit corrosion and wear of mechanical systems, enabling them to be maintained in good condition for as long as possible. Therefore, lubricating fluids are used in various fields such as metallurgy, mining, aviation, and the automotive industry. These are used in the metallurgical industry, particularly to cool and lubricate metal parts during their production and/or processing. When used in this context, they are generally referred to as metalworking fluids. This is because they reduce heat and friction between tools and metal parts while preventing surface combustion and the release of fumes. The term "metalworking fluid" applies to any fluid used for the production, removal, forming, quenching, or protection of metals. The use of these fluids also improves the quality of metal parts by continuously removing fine particles, lathe shavings, and metal filings that accumulate on both the surfaces of the used tools and parts. Therefore, they are essential in this field and are classified into four main categories: pure oils, emulsifying oils, semi-synthetic fluids, and synthetic fluids. These categories are specifically defined in the standard ASTM D2881-19, Standard Classification for Metalworking Fluids and Related Materials . Pure oils generally contain mineral oil and do not contain water. They may contain functional additives and do not emulsify in the presence of water. Emulsifying oils (also called soluble oils) typically contain at least 30 weight percent of mineral oil. They also contain emulsifiers and other types of functional additives to subsequently dilute in water to form a macroemulsion (having an average particle size of greater than 1 μm). Semi-synthetic fluids generally contain less than 50% by weight of mineral oil and at least 20% by weight of water. They contain emulsifiers and other functional additives. When diluted with water, they generally form a microemulsion (having an average particle size of less than 1 μm). Finally, synthetic fluids do not contain mineral oil. They are divided into solution synthetic fluids, emulsion synthetic fluids, and pure synthetic oils. All such lubricating fluids must meet numerous criteria regardless of their end use. In addition to tribological properties, their composition must be stable, especially during storage. This applies particularly to fluids that form emulsions, including both water and oil(s). This is because this type of fluid is easily contaminated by microorganisms, such as bacteria or fungi, due to the presence of water in this formulation. Additionally, residual oils, such as hydraulic oil or gear oil, can represent another form of contamination. These oils leak and mix with the fluid. They can then contribute to the growth of microorganisms by providing them with nutrients and creating various conditions favorable for anaerobic growth. Therefore, avoiding microbial growth is a major challenge in the field of lubricating fluids, which include both water and oil(s), and especially in metalworking fluids (see, e.g., "Metalworking Fluid Basics, in Tribology & Lubrication Technology" by STLE MWF Education & Training Committee, March 2023, 54-62). These contaminants can cause emulsion destabilization and/or alter fluid properties. These microbial communities are also responsible for corrosive phenomena in metals. They can also form biofilms on surfaces that prevent or interfere with production or processing operations and require significant maintenance. To prevent all these phenomena, biocides are commonly added to lubricating fluids. However, biocides can be harmful to users, and increasingly restrictive health regulations are being enforced. Furthermore, their systematic use can lead to the emergence of strains resistant to them. Therefore, it is desirable to limit the use of biocides as much as possible and to seek new compounds that are equally effective, less harmful, and more environmentally friendly. Therefore, there is a need for novel functional additives for lubricating fluids containing both water and oil(s). In particular, there is a need for lubricating fluids containing both water and oil(s) that are effective and exhibit good stability, especially