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EP-4737543-A1 - LUBRICATING OIL COMPOSITION

EP4737543A1EP 4737543 A1EP4737543 A1EP 4737543A1EP-4737543-A1

Abstract

There has been a need for development of a lubricating oil composition which is reduced in the oil evaporation amount at lower temperatures, and is capable of improving the fuel consumption saving. Disclosed is a lubricating oil composition which includes a base oil (A) in which the content of a fraction containing hydrocarbon groups having not less than 14 but less than 16 carbon atoms is within the range of 0.10% by mass to 0.60% by mass based on the total amount of the base oil (A), and the content of a fraction containing hydrocarbon groups having not less than 16 but less than 18 carbon atoms is within the range of 0.35% by mass to 1.85% by mass based on the total amount of the base oil (A).

Inventors

  • FUJITA, Shoichiro
  • YAMASHITA, JUN
  • NAKAUE, DAISUKE

Assignees

  • Idemitsu Kosan Co.,Ltd.

Dates

Publication Date
20260506
Application Date
20240606

Claims (7)

  1. A lubricating oil composition comprising, as a base oil (A), a base oil in which the amount of a fraction containing hydrocarbon groups having 14 or more and less than 16 carbon atoms is in the range of 0.10 to 0.60 mass% based on the total amount of the base oil (A), and the amount of a fraction containing hydrocarbon groups having 16 or more and less than 18 carbon atoms is in the range of 0.35 to 1.85 mass% based on the total amount of the base oil (A).
  2. The lubricating oil composition according to claim 1, comprising an ashless friction modifier (C1), wherein the ashless friction modifier (C1) has a weight-average molecular weight (Mw) of 100 or more and less than 50,000.
  3. The lubricating oil composition according to claim 1, comprising an ashless friction modifier (C1), wherein the ashless friction modifier (C1) has a weight-average molecular weight (Mw) of 1,000 or more and less than 50,000.
  4. The lubricating oil composition according to any one of claims 1 to 3, further comprising, as the base oil (A), at least one base oil selected from the group consisting of poly-α-olefin (A1) and an ester-based oil (A2).
  5. The lubricating oil composition according to claim 4, comprising, as the base oil (A), an ester-based oil (A2).
  6. The lubricating oil composition according to any one of claims 1 to 5, further comprising a viscosity index improver (B) containing a comb polymer (B1).
  7. The lubricating oil composition according to any one of claims 1 to 6, further comprising a molybdenum-based friction modifier (C2).

Description

Technical Field The present invention relates to a lubricating oil composition. Background Art As an index of oil evaporability, a NOACK test at 250°C specified by ASTM D5800 has been widely used, but with advancement of engines, a correlation between the NOACK value and the amount of oil evaporation (amount of consumption) in an actual usage environment is not obtained occasionally. Under such circumstances, it has been reported that there is a correlation between the value of oil evaporability at lower temperatures and the amount of actual oil consumption (Non Patent Literature 1) Citation List Non Patent Literature Non Patent Literature 1 Transactions of the Society of Automotive Engineers of Japan, Inc., Vol. 52, No. 6, November 2021 Summary of Invention Technical Problem Under such circumstances, development of a lubricating oil composition which is reduced in the amount of oil evaporation at lower temperatures and is capable of improving fuel consumption saving performance has been desired. Solution to Problem As a result of earnest studies, the present inventors have found that by using a base oil of specific fractions in a given amount, the above problem can be solved, and have completed the present invention. That is, the present invention provides the following embodiment. [1] A lubricating oil composition comprising, as a base oil (A), a base oil in which the amount of a fraction containing hydrocarbon groups having 14 or more and less than 16 carbon atoms is in the range of 0.10 to 0.60 mass% based on the total amount of the base oil (A), and the amount of a fraction containing hydrocarbon groups having 16 or more and less than 18 carbon atoms is in the range of 0.35 to 1.85 mass% based on the total amount of the base oil (A). Advantageous Effects of Invention One preferred embodiment of the present invention provides a lubricating oil composition which is reduced in the amount of oil evaporation at temperatures lower than 250°C. In addition, one preferred embodiment of the present invention provides a lubricating oil composition having a low kinematic viscosity at 40°C and capable of improving fuel consumption saving performance. Description of Embodiments Regarding the numerical range described in the present specification, the upper limit and the lower limit can be combined freely. For example, with the description "preferably 30 to 100, more preferably 40 to 80" as numerical ranges, the range of "30 to 80" and the range of "40 to 100" are also included in the numerical ranges described in the present specification. Alternatively, for example, with the description "preferably 30 or more, more preferably 40 or more, and preferably 100 or less, more preferably 80 or less" as numerical ranges, the range of "30 to 80" and the range of "40 to 100" are also included in the numerical ranges described in the present specification. In addition, for example, the description of "60 to 100" as a numerical range described in the present specification means a range of "60 or more (60 or more than 60) and 100 or less (100 or less than 100)". The numerical range of a lower limit to an upper limit can be defined by appropriately selecting values from among respective options and optionally combining them in the definition of the upper limit and the lower limit described in the present specification. In addition, a plurality of various requirements described in the present specification as preferred embodiments can be combined. [Constitution of lubricating oil composition] The lubricating oil composition according to one embodiment of the present invention includes, as a base oil (A) (also referred to as a "component (A)" hereinafter), a base oil in which the amount of a fraction containing hydrocarbon groups having 14 or more and less than 16 carbon atoms is in the range of 0.10 to 0.60 mass% based on the total amount of the base oil (A), and the amount of a fraction containing hydrocarbon groups having 16 or more and less than 18 carbon atoms is in the range of 0.35 to 1.85 mass% based on the total amount of the base oil (A). According to the present constitution, the NOACK value at 150°C can be set to less than the defined value, and therefore, a lubricating oil composition which is reduced in the amount of oil consumption even in an actual usage environment can be obtained. According to the present constitution, moreover, a lubricating oil composition having a low kinematic viscosity at 40°C and having excellent fuel consumption saving performance can be obtained. In the present specification, the NOACK value at 150°C means a value measured at 150°C for 12 hours in accordance with ASTM D5800 (also referred to as NOACK 150°C hereinafter). Hereinafter, details of each component contained in the lubricating oil composition according to one embodiment of the present invention will be described. <Component (A): base oil> The lubricating oil composition of the present invention uses, as a base oil (A), a base oi