Idemitsu Kosan Company, Limited

Tahei Okada

Yukitoshi Fujinami

Takuya Ohno

Atsushi Yokouchi

Hideto Kamimura

Hiroshi Nagakawa

Shinya Nakatani

Shigeo Hara

Masahiko Takesue

Keizo Murata

Shoji Aoyama

Yumiko Kiko

Yoshiaki Aiki

Sabro Koyama

A lubricating oil composition containing a base oil having a kinematic viscosity at 40 degrees C. in a range from 10 mm/s to 1000 mm/s with: (A) at least one of phosphorus compounds represented by a formula (1) in an amount of 0.001 mass % to 0.3 mass % in terms of a phosphorus content; (B) at least one of a sulfur compound represented by a formula (2) and a sulfur compound that comprises a dithio (&#x2014;S&#x2014;S&#x2014;) bond in a molecule in an amount of 0.01 mass % to 0.5 mass % in terms of a sulfur content, the latter sulfur compound, when added to the base oil in an amount of 1 mass %, leading to a rating of 2 or lower in a copper strip corrosion test; and (D) a succinimide derivative in an amount of 0.01 mass % to 1 mass %. 

Lubricating oil composition

A biodegradable lubricating oil composition includes (A) an ester represented by a formula (1) below, the ester having a kinematic viscosity in a range from 300 mm/s to 1000 mm/s at 40 degrees C. and an acid value of 0.5 mgKOH/g or less; (B) an ester being obtained by reacting a straight-chain saturated aliphatic carboxylic acid with a polyhydric alcohol, the ester having an acid value of 0.5 mgKOH/g or less; and (C) a phosphate amine salt being obtained by reacting an acidic phosphate with an alkylamine. In the formula, Ra is a hydrocarbyl group having 4 to 20 carbon atoms, Rb is a hydrocarbyl group having 4 to 18 carbon atoms, Rc is an acyl group having 1 to 10 carbon atoms, and n is an integer of 3 to 15.

Biodegradable lubricant composition

A lubricating oil composition for high-temperature applications contains (A) a pyromellitate ester, (B) a sulfur-containing triazine antioxidant, and (C) a thiophosphoric acid ester antioxidant. When the lubricating oil composition for high-temperature applications according to the invention is applied to a chain, a gear, a bearing and the like, an amount of evaporation of the lubricating oil composition is restrained for a long time and fluidity thereof is also kept for a long time.

Lubricating oil composition for high-temperature applications

A biodegradable lubricating oil composition includes (A) an ester being obtained by reacting a saturated aliphatic carboxylic acid, a straight-chain aliphatic dicarboxylic acid and a polyhydric alcohol together, the ester having a kinematic viscosity in a range from 400 mm/s to 1000 mm/s at 40 degrees C. and an acid value of 0.5 mgKOH/g or less; (B) an ester being obtained by reacting a straight-chain saturated aliphatic carboxylic acid with a polyhydric alcohol, the ester having an acid value of 0.5 mgKOH/g or less; and (C) a phosphate amine salt being obtained by reacting an acidic phosphate with an alkylamine.

A grease which comprises a base oil containing at least 50% by mass of a diester compound having a total carbon number of 28 to 40 and represented by the general formula (I):ROOC&#x2014;(R)&#x2014;COOR&#x2003;&#x2003;(I)wherein Rand Reach independently represent a Cto Cmonovalent aliphatic hydrocarbon group, Rrepresents a Cto Cdivalent hydrocarbon group and n is 0 or 1. The grease is excellent in both low-temperature performance and high-temperature performance and has low oil separation tendency even under high centrifugal force (acceleration). In particular, when the grease is used in a rotational transmission device having a built-in one-way clutch, the grease can provide satisfactory clutch engagement property (intermeshing ability) at low temperatures and a prolonged bearing life at high temperatures and is less apt to cause oil separation under high centrifugal force.

Grease

To provide a gear oil composition containing a base oil, and compounded therein, (A) an ashless dithiocarbamate compound and (B) an ester of pentaerythritol and a Cto Cbranched fatty acid, the ester having a hydroxyl value of 20 to 100 mg KOH/g. The gear oil composition has a high transmission efficiency and shows both of resistance to sludge formation and extreme pressure property.

Gear oil composition

The present invention provides a pressure-medium oil comprising at least one of a hydrocarbon compound and an ether compound and having the following properties (1) to (4):

Pressure medium oil

A metal working oil composition having a kinematic viscosity of 20 cSt or less at a temperature of 40.degree. C. is herein disclosed which comprises (A) 10% by weight or more of an n-.alpha.-olefin (e.g. 1-hexadecene) and (B) an overbased sulfonate having a total base number of 350 mg.multidot.KOH/g or more in such an amount that the total base number of the composition is 12.5 mg.multidot.KOH/g or more. The metal working oil composition is particularly suitable as a press lubricant for aluminum alloys, has an excellent mass workability, and is more excellent in coating workability, lubricity, degreasing properties, weldability, etc. than a conventional solid coating type lubricant.

Metal working oil composition

A fluid composition for use in a shock absorber is described, comprising (a) a lubricating base oil, (b) 10 to 1,000 ppm, as calculated as boron, of a boron-containing compound, and (c) 100 to 3,000 ppm, as calculated as phosphorus, of phosphoric acid ester and/or phosphorous acid ester. The invention also provides a shock absorber containing said fluid composition as the shock absorber fluid. This shock absorber has the advantage of high abrasion resistance and a low coefficient of friction of movement of the movable parts relative to the stationary parts therein.

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Ichihara, Japan

Tahei Okada