A lubricating oil composition including greater than 50% by weight of a base oil, based on the total weight of the lubricating oil composition and an additive for boosting the TBN of the lubricating oil without increasing the sulphated ash content. Also disclosed is a method for boosting the TBN of the lubricating oil composition as measured by both ASTM D-2896 and ASTM D-4739 without increasing the sulphated ash content by adding a TBN booster. The TBN booster can also be employed to improve results for the lubricating oil composition in a ball rust test and certain of the TBN boosters exhibit outstanding seal compatibility.

A lubricating oil composition including greater than 50% by weight of a base oil, based on the total weight of the lubricating oil composition and an additive for boosting the TBN of the lubricating oil without increasing the sulphated ash content. Also disclosed is a method for boosting the TBN of the lubricating oil composition as measured by both ASTM D-2896 and ASTM D-4739 without increasing the sulphated ash content by adding a TBN booster. The TBN booster can also be employed to improve results for the lubricating oil composition in a ball rust test and certain of the TBN boosters exhibit outstanding seal compatibility.

A lubricant additive capable of imparting various functions to a lubricant base oil contains an ester compound (A) represented by formula (1) and an ester compound (B) represented by formula (2). (A):(B) being a mass ratio of the ester compound (A) to the ester compound (B) is 99:1 to 80:20.

A lubricant additive capable of imparting various functions to a lubricant base oil contains an ester compound (A) represented by formula (1) and an ester compound (B) represented by formula (2). (A):(B) being a mass ratio of the ester compound (A) to the ester compound (B) is 99:1 to 80:20.

A lubricant additive capable of imparting various functions to a lubricant base oil contains an ester compound (A) represented by formula (1) and an ester compound (B) represented by formula (2). (A):(B) being a mass ratio of the ester compound (A) to the ester compound (B) is 99:1 to 80:20.

A lubricant additive capable of imparting various functions to a lubricant base oil contains an ester compound (A) represented by formula (1) and an ester compound (B) represented by formula (2). (A):(B) being a mass ratio of the ester compound (A) to the ester compound (B) is 99:1 to 80:20.

Provided is a water-soluble metalworking oil comprising a base oil (A) comprising oil-soluble polyalkylene glycol (A1), wherein a total content of water-soluble polyalkylene glycol and methoxypolyethylene glycol is less than 60% by mass based on the total amount excluding water.

Provided is a water-soluble metalworking oil comprising a base oil (A) comprising oil-soluble polyalkylene glycol (A1), wherein a total content of water-soluble polyalkylene glycol and methoxypolyethylene glycol is less than 60% by mass based on the total amount excluding water.

A water-soluble metalworking oil may include 0.7% by mass or more of 2-phenoxyethanol (A), based on the total water-soluble metalworking oil mass. A content of petroleum sulfonate may be less than 10 parts by mass, based on 100 parts by mass of the 2-phenoxyethanol (A). The 2-phenoxyethanol (A) may be present in a range of from 0.7 to less than 5.0% by mass. The water-soluble metalworking oil may further include: an amine, a fatty acid (C), and/or a nonionic surfactant (D).

A water-soluble metalworking oil may include 0.7% by mass or more of 2-phenoxyethanol (A), based on the total water-soluble metalworking oil mass. A content of petroleum sulfonate may be less than 10 parts by mass, based on 100 parts by mass of the 2-phenoxyethanol (A). The 2-phenoxyethanol (A) may be present in a range of from 0.7 to less than 5.0% by mass. The water-soluble metalworking oil may further include: an amine, a fatty acid (C), and/or a nonionic surfactant (D).