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EP-4741373-A1 - SULFIDE COMPOUND, EXTREME PRESSURE ADDITIVE, AND LUBRICANT OIL COMPOSITION CONTAINING SAID EXTREME PRESSURE ADDITIVE

EP4741373A1EP 4741373 A1EP4741373 A1EP 4741373A1EP-4741373-A1

Abstract

Provided is a sulfide compound capable of functioning as an extreme pressure agent excellent in oxidation stability and stability of a frictional wear reducing effect. Specifically, a sulfide compound containing at least a fatty acid triglyceride and sulfur as reaction components, wherein a content proportion of oleic acid in fatty acids constituting the fatty acid triglyceride is 80 mass% or more.

Inventors

  • MATSUEDA, HIRONOBU

Assignees

  • DIC Corporation

Dates

Publication Date
20260513
Application Date
20240620

Claims (9)

  1. A sulfide compound comprising at least a fatty acid triglyceride and sulfur as reaction components, wherein a content proportion of oleic acid in fatty acids constituting the fatty acid triglyceride is 80 mass% or more.
  2. The sulfide compound according to claim 1, wherein a content proportion of linoleic acid in the fatty acids constituting the fatty acid triglyceride is 5 mass% or less.
  3. The sulfide compound according to claim 1 or 2, wherein the fatty acid triglyceride is an algal oil.
  4. The sulfide compound according to claim 1 or 2, wherein a proportion of the sulfur in the reaction components is in a range of from 5 to 35 mass% relative to a total amount of the reaction components.
  5. The sulfide compound according to claim 1 or 2, further comprising an unsaturated fatty acid alkyl ester as the reaction component.
  6. The sulfide compound according to claim 5, wherein the unsaturated fatty acid alkyl ester is contained in an amount in a range of from 10 to 300 parts by mass relative to 100 parts by mass of the fatty acid triglyceride.
  7. The sulfide compound according to claim 1 or 2, wherein a kinematic viscosity at 40°C is in a range of from 100 to 1500 mm 2 /s.
  8. The sulfide compound according to claim 1 or 2, wherein the sulfide compound is an extreme pressure agent.
  9. A lubricant oil composition comprising a base oil and the extreme pressure agent described in claim 8.

Description

TECHNICAL FIELD The present invention relates to a sulfide compound, an extreme pressure agent, and a lubricant oil composition containing the extreme pressure agent. BACKGROUND ART Lubricant oils such as gear oils, engine oils, hydraulic oils, cutting oils, plastic working oils, and casting oils are used by blending various additives such as extreme pressure agents, oiliness agents, antioxidants, rust inhibitors, corrosion inhibitors, antifoaming agents, and nonferrous metal corrosion inhibitors with base oils such as mineral oils, fats and oils, and synthetic oils. Among the above additives, the extreme pressure agent is an additive for reducing frictional wear between metals, and various extreme pressure agents such as a chlorine-based extreme pressure agent, a sulfur-based extreme pressure agent, a phosphorus-based extreme pressure agent, and an organic metal compound-based extreme pressure agent have been proposed (for example, Patent Documents 1 to 3). CITATION LIST PATENT DOCUMENT Patent Document 1: JP 2021-500244 APatent Document 2: WO2020/030189Patent Document 3: WO2014/188948 SUMMARY OF INVENTION TECHNICAL PROBLEM Since the lubricant oil is generally exposed to high temperature and high pressure, there is a problem that the extreme pressure agent is oxidized and deteriorated, and thus that the intended effect cannot be obtained. Due to such a problem, oxidation stability is required also for the extreme pressure agent as an additive, but the extreme pressure agents of Patent Documents 1 to 3 cannot meet the required performance. In addition, the extreme pressure agent is required to stably exhibit a frictional wear reducing effect under various loads, but the stability of a frictional wear reducing effect of the extreme pressure agents of Patent Documents 1 to 3 cannot be said to be sufficient. An object of the present invention is to provide a sulfide compound which has excellent oxidation stability and excellent stability of an effect of reducing frictional wear between metals, and can function as, for example, an extreme pressure agent. Another object of the present invention is to provide an extreme pressure agent having excellent oxidation stability and excellent stability of the frictional wear reducing effect, and a lubricant oil composition containing the extreme pressure agent. SOLUTION TO PROBLEM The present inventors have conducted intensive studies to solve the above problems, and, as a result, have found that a sulfide compound containing at least an oleic acid-rich unsaturated fatty acid and sulfur as reaction components is excellent in oxidation stability and frictional wear reducing effect stability, thereby completing the present invention. That is, the present invention relates to the following sulfide compound and the like. 1. A sulfide compound containing at least a fatty acid triglyceride and sulfur as reaction components, wherein a content proportion of oleic acid in fatty acids constituting the fatty acid triglyceride is 80 mass% or more.2. The sulfide compound according to 1, wherein a content proportion of linoleic acid in the fatty acids constituting the fatty acid triglyceride is 5 mass% or less.3. The sulfide compound according to 1 or 2, wherein the fatty acid triglyceride is an algal oil.4. The sulfide compound according to any one of 1 to 3, wherein a proportion of the sulfur in the reaction components is in a range of from 5 to 35 mass% relative to a total amount of the reaction components.5. The sulfide compound according to any one of 1 to 4, further containing an unsaturated fatty acid alkyl ester as the reaction component.6. The sulfide compound according to 5, wherein the unsaturated fatty acid alkyl ester is contained in an amount in a range of from 10 to 300 parts by mass relative to 100 parts by mass of the fatty acid triglyceride.7. The sulfide compound according to any one of 1 to 6, wherein a kinematic viscosity at 40°C is in a range of from 100 to 1500 mm2/s.8. The sulfide compound according to any one of 1 to 7, which is an extreme pressure agent.9. A lubricant oil composition containing a base oil and the extreme pressure agent according to claim 8. ADVANTAGEOUS EFFECTS OF INVENTION According to the present invention, it is possible to provide a sulfide compound which has excellent oxidation stability and excellent stability of an effect of reducing frictional wear between metals, and can function as, for example, an extreme pressure agent. According to the present invention, it is possible to provide an extreme pressure agent having excellent oxidation stability and excellent stability of the frictional wear reducing effect, and a lubricant oil composition containing the extreme pressure agent. DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of the present invention will be described. The present invention is not limited by the following embodiments, and modification can be appropriately applied in a range that does not impair the effect of the