Idemitsu Kosan Company, Limited

Shinji Aoki

Moritsugu Kasai

Tadashi Kisen

Asami Koga

Jitsuo Shinoda

Masahiro Kobessho

Keizo Murata

Shota Hirakawa

Shota Inoue

Hidenori Torii

The present invention relates to a hydraulic fluid composition containing a base oil (A), an antioxidant (B) including an amine-based antioxidant (B1) and a phenol-based antioxidant (B2), and a succinimide-based compound (C), wherein the hydraulic fluid composition satisfies the following requirement (I); and is to be used for hydraulic equipment which is equipped with at least one of a wet type brake and a wet type clutch and which is selected from a construction machinery, a general industrial machinery, and a power generator, and in which a working pressure is 30 MPa or more. The hydraulic fluid composition is not only excellent in wear resistance and an effect for suppressing the sludge formation but also excellent in a braking performance or a clutch performance, even when used under a high-pressure condition. Requirement (I): A static friction coefficient (&#x3bc;) after 1,000 cycles, as measured in conformity with the SAE No. 2 test described in JCMAS P 047:2004, is 0.100 to 0.162.

Hydraulic oil composition

Provided is a lubricating oil composition comprising a base oil (A) containing a polyalkylene glycol (A1) and a polyol ester (A2), a phosphorus-based rust inhibitor (B), and an antioxidant (C) containing an amine-based antioxidant (C1). The lubricating oil composition exhibits a strong effect for suppressing sludge sedimentation even when used for an extended period of time in a high-temperature environment, and has excellent demulsibility and rust preventive properties, and therefore, can be suitably used in turbomachinery, compressors, hydraulic equipment, and machine tools.

Lubricant composition

Provided is a lubricating oil composition containing a base oil (A) and an amine-based antioxidant (B), wherein the component (B) contains a phenyl-naphthylamine (B1), an alkylphenyl-naphthylamine (B2) and a di(alkylphenyl)amine (B3), the content of the component (B1) is 2.0 to 10.0% by mass relative to 100% by mass of the total amount of the component (B), the content of the component (B2) is 40.0 to 90.0% by mass relative to 100% by mass of the total amount of the component (B), and the content of the component (B3) is 8.0 to 50.0% by mass relative to 100% by mass of the total amount of the component (B). The lubricating oil composition maintains excellent oxidation stability even in long-term use in high-temperature environments, and has an excellent lifetime and is excellent also in a sludge preventing effect.

Lubricant oil composition

A turbine oil used in a turbine of a jet engine, containing: a base oil (A) containing a polyol ester (A1); an antioxidant (B) containing an amine-based antioxidant (B1); a polymethacrylate (C) having a weight average molecular weight of 50,000 to 600,000; and an alkyl aromatic compound (D), having a content of the component (D) of 1,000 parts by mass or less per 100 parts by mass of a total resin content of the component (C), and satisfying the following requirements (1) and (2): requirement (1): a viscosity index of 140 or more; and requirement (2): a coking amount attached to a panel of 80 mg or less after a panel coking test under the prescribed condition. The turbine oil has a high viscosity index to such an extent that an oil film can be retained in the use under a high temperature environment as in a turbine of a jet engine mounted on an aircraft, and is excellent in low temperature viscosity characteristics while retaining excellent heat resistance.

Turbine oil, and method for using turbine oil

The present invention provides a mineral base oil having a kinetic viscosity at 100&#xb0; C. of 7 mm/s or more and less than 10 mm/s, a viscosity index of 100 or more, and a temperature gradient &#x394;|&#x3b7;*| complex viscosity between two temperature points of &#x2212;5&#xb0; C. and &#x2212;15&#xb0; C. of 240 mPa&#xb7;s/&#xb0; C. or less as measured with a rotary rheometer at an angular velocity of 6.3 rad/s. The use of the mineral base oil enables easy preparation of a lubricating oil composition and a grease composition having excellent oxidation stability while ensuring the freedom of selection of additives.

Mineral oil-based base oil, lubricating oil composition, equipment, lubricating method, and grease composition

A lubricating oil composition contains: a base oil with a kinematic viscosity at 40 degrees C. in a range from 1 mm/s to 200 mm/s, a viscosity index of 80 or more and a sulfur content of less than 0.03 mass %; a component (A) being a polyacrylate compound with a mass average molecular weight in a range from 10,000 to 100,000; and a component (B) being at least one of phosphorus compounds represented by a formula (1) below. A content of the component (B) is in a range from 0.05 mass % to 2.0 mass % of a total amount of the composition, and a viscosity index of the composition is 160 or more. 

A lubricating oil composition prepared by blending a base oil (A) containing a compound (A1) that is an ester or ether and has two or more aromatic rings, with a polyalkylene glycol (B) is provided. The lubricating oil composition has a high density (i.e., a high bulk modulus), a high viscosity index, and excellent shear stability.

Lubricating oil composition

Provided are a pressure medium oil, containing a Group-14 element-containing organic compound selected from an organic germanium compound, an organic tin compound, and an organic lead compound, and a method for using a pressure medium oil, which includes applying a pressure to a substance via the pressure medium oil. The pressure medium oil does not solidify even under an ultrahigh pressure of more than 3.7 GPa at room temperature (25&#xb0; C.) and has a low pour point, and hardly dissolves a conductive paste.

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Sodegaura, Japan

Shinji Aoki