Idemitsu Kosan Company, Limited

Yasunori Shimizu

Junya Iwasaki

Yoriyuki Takashima

A lubricating oil composition, containing a base oil (A), an aromatic carboxylic acid ester having one or more hydroxyl groups (B), and a sulfur-based antioxidant (C). A content of phosphorus atoms is 0.06% by mass or less, based on a total amount of the lubricating oil composition, and a sulfated ash content is 0.6% by mass or less, based on the total amount of the lubricating oil composition.

Lubricating oil composition

The lubricating oil composition according to the present invention is one including a base oil, (A) a substituted hydroxy aromatic carboxylic acid ester derivative represented by at least one of the general formula (I) and the general formula (II), and (B) a heterocyclic compound represented by the general formula (III) or (IV) blended therein, wherein a phosphorus content is 0.06 mass % or less on the basis of a total amount of the composition, and a sulfated ash content is 1.2 mass % or less on the basis of a total amount of the composition. The lubricating oil composition is capable of maintaining high-temperature detergency and acid neutralizing properties, even when amounts of a phosphorus component-containing additive and a metallic detergent are reduced.

Lubricant composition

Lubricating oil compositions may include a base oil, a succinimide compound, and a thioheterocyclic compound. Such compositions may have a sulfur content of 0.10 mass % to 1.00 mass % based on a total amount of the composition. A phosphorus content represented by P in mass % and a sulfated ash content represented by M in mass %, based on the total amount of such compositions, may satisfy any of conditions A to C: condition A: P&#x3c;0.03, and M&#x3c;0.3; condition B: P&#x3c;0.03 and 0.3&#x2266;M&#x2266;0.6; and condition C: 0.03&#x2266;P&#x2266;0.06 and M&#x3c;0.3.

Lubricating oil composition for engine made of aluminum alloy and lubrication method

The present disclosure relates to a lubricating oil composition containing a base oil, a thioheterocyclic compound represented by the formula:(R)&#x2014;(S)&#x2014;As&#x2014;(S)&#x2014;(R),and an aminoalcohol compound containing, in the molecule thereof, a piperazine moiety and one or more hydroxyl groups. The lubricating oil composition has a phosphorus content (P mass %) and a sulfated ash content (M mass %), based on a total mass of the lubricating oil composition, satisfying any of the following conditions A to C:

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Ichihara, Japan

Yasunori Shimizu