Lubricating oil composition and method for using lubricating oil composition

A lubricating oil composition with a specific blend of antioxidants for base oils with tertiary carbon atoms addresses oxidation stability and initial acid value issues, achieving prolonged stability and reduced acid rise in high-temperature conditions.

EP4116395B1Active Publication Date: 2026-06-24IDEMITSU KOSAN CO LTD
View PDF 11 Cites 0 Cited by

Patent Information

Application Number
EP2021763829
Authority / Receiving Office
EP · EP
Patent Type
Patents
Current Assignee / Owner
Priority Date
2020-03-06
Filing Date
2021-03-05
Publication Date
2026-06-24
Estimated Expiration
2041-03-05

AI Technical Summary

Technical Problem

Lubricating oil compositions containing a certain amount or more of tertiary carbon atoms face challenges in maintaining oxidation stability over a long period and suppressing the initial rise in acid value, as conventional antioxidants are ineffective in these oils, and traditional evaluation methods like RPVOT do not accurately reflect real-world performance.

Method used

A lubricating oil composition comprising a base oil with 8.0% or more tertiary carbon atoms, combined with a specific blend of amine-based, phenol-based, and phosphor-based antioxidants, including diphenylamine, hindered phenol compounds with ester structures, and phosphite antioxidants, within defined content ranges, to enhance oxidation stability and suppress initial acid value rise.

Benefits of technology

The composition maintains excellent oxidation stability over time and suppresses initial acid value increase, ensuring prolonged performance in high-temperature environments.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure IMGB0001
    Figure IMGB0001
  • Figure IMGB0002
    Figure IMGB0002
  • Figure IMGB0003
    Figure IMGB0003
Patent Text Reader

Abstract

The task is to provide a lubricating oil composition capable of maintaining oxidation stability over a long period of time by not only making oxidation stability evaluated by an RPVOT value excellent even while using a base oil comprising a certain amount or more of tertiary carbon atom but also suppressing a rise in acid value in the initial stage. Said task is attained by providing a lubricating oil composition comprising a base oil (X) comprising tertiary carbon atom at a content of 8.0 at% or more based on the total carbon of hydrocarbons, and an antioxidant (Y) comprising an amine-based antioxidant (A), a phenol-based antioxidant (B), and a phosphor-based antioxidant (C), and satisfying the following requirements. Specifically, the amine-based antioxidant (A) comprises a diphenylamine compound (A1) having a specific structure. The phenol-based antioxidant (B) comprises a hindered phenol compound (B1) having an ester structure. Furthermore, the total content [(A1) + (B1) + (C)] of the diphenylamine compound (A1), the hindered phenol compound (B1) having an ester structure, and the phosphor-based antioxidant (C) was set to greater than 1.0 mass% and 2.0 mass% or less based on the total amount of the lubricating oil composition.
Need to check novelty before this filing date? Find Prior Art

Citation Information

Patent Citations

  • Lubricating oil composition for rotary gas compressor

    JP2011162629A

  • Lubricating oil composition

    EP3778832A1

  • Lubricating oil composition

    JP1993302093A

  • Stabilizer composition for lubricating oil

    JP2004501234A

  • Lubricating oil composition

    JP2007161773A