Abstract: Provided are a lubricating oil base oil having characteristics of low volatility and excellent low-temperature fluidity and capable of providing long-lasting lubrication property in a wide temperature range from low temperature to high temperature, and a lubricating oil composition using the same. The lubricating oil base oil includes a diester obtained through a reaction between a diol component formed of 1,12-dodecanediol and a carboxylic acid component formed of 2-methylpentanoic acid or 2-methylpentanoic acid and 2-ethylhexanoic acid. The diester is represented by R2COOR1OOCR3, where R1 represents an alkylene derived from the diol component and R2 and R3 each represent an alkyl derived from the carboxylic acid component, and includes 45 to 100 mol % of a diester in which both of R2 and R3 represent C5 alkyls.

Abstract: A lubricating oil base oil includes, as a major component, a diester represented by the following formula (1), and a lubricating oil composition including the lubricating oil base oil. In the formula, R1 and R2 each independently represent a 1-ethylpentyl group, an n-heptyl group, or a n-hexyl group. When the diester in which both of R1 and R2 each represent an n-heptyl group or an n-hexyl group is defined as A, the diester in which one of R1 and R2 represents a 1-ethylpentyl group is B, and the diester in which both of R1 and R2 each represent a 1-ethylpentyl group is defined as C, the molar ratio of the diesters falls within a range of A:B:C=25 to 65:30 to 50:3 to 25. The lubricating oil base oil is suitable for a fluid dynamic pressure bearing, an oil-impregnated porous bearing, or a dynamic pressure-type oil-impregnated porous bearing.

Abstract: Provided are a lubricating oil base oil excellent in durability and low-torque property, and a lubricating oil composition suitable for a fluid dynamic pressure bearing, an oil-impregnated porous bearing, or a dynamic pressure-type oil-impregnated porous bearing to be used in a bearing for a small spindle motor related to information equipment. Specifically, provided are a lubricating oil base oil including, as a major component, a diester represented by the following formula (1), and a lubricating oil composition including the lubricating oil base oil.

Abstract: Provided are a lubricating oil base oil having characteristics of low volatility and excellent low-temperature fluidity and capable of providing long-lasting lubrication property in a wide temperature range from low temperature to high temperature, and a lubricating oil composition using the same. The lubricating oil base oil includes a diester obtained through a reaction between a diol component formed of 1,12-dodecanediol and a carboxylic acid component formed of 2-methylpentanoic acid or 2-methylpentanoic acid and 2-ethylhexanoic acid. The diester is represented by R2COOR1OOCR3, where R1 represents an alkylene derived from the diol component and R2 and R3 each represent an alkyl derived from the carboxylic acid component, and includes 45 to 100 mol % of a diester in which both of R2 and R3 represent C5 alkyls.

Abstract: A plurality of object arrays in which a plurality of objects are sorted under a plurality of order conditions are generated. A display image is generated by sorting the objects in an order for each object array to line up in the first direction for each of the plurality of object arrays, selecting one object of a first object array of the plurality of object arrays as a reference object, and sorting the objects for each of the plurality of object arrays so that the reference object and objects corresponding to the reference object included in the object arrays other than the first object array line up in the second direction.

Abstract: Disclosed is lubricant base oil that is excellent in lubricity, sludge solubility, low viscosity, and low temperature characteristics and capable of realizing low volatility. The lubricant base oil contains as its main component a diester or triester synthesized from a divalent or trivalent carboxylic acid of 9 or less carbon atoms and a monovalent glycol ether such as an alkylene glycol monoalkyl ether of 3 to 25 carbon atoms and is useful as base oil for lubricating oil and grease. Di(hexyloxyethyl) adipate may be cited as an appropriate example of the diester.

Abstract: A hydrodynamic type oil-impregnated sintered bearing includes a porous bearing body of sintered metal having a bearing surface in which hydrodynamic pressure generating grooves slating against an axial direction are provided. Lubricating oil or the base oil of lubricating grease to be impregnated into the bearing body is selected from among (a) mixtures of poly-?-olefin or hydrogenated compound thereof and ester and (b) ester. The ester is preferably polyol ester. In the cases of the lubricating grease, the thickener of the lubricating grease is preferably composed of urea compound. A plurality of bearing surfaces may be formed on the inner periphery of the bearing body so as to be separated from one another. The hydrodynamic type oil-impregnated sintered bearing may be suitably applied to a spindle motor for information equipment.

Abstract: A hydrodynamic type oil-impregnated sintered bearing includes a porous bearing body of sintered metal having a bearing surface opposed to a sliding surface of a rotating shaft, hydrodynamic pressure generating grooves slanting against an axial direction provided in the bearing surface, and lubricating oil or lubricating grease impregnated in pores inside the bearing body, wherein a rate of area of surface holes on the bearing surface is set within a range of 3%-15%, the surface holes being distributed substantially uniformly over the whole area of the bearing surface including areas of the hydronamic pressure generating grooves, wherein the lubricating oil or a base oil of the lubricating grease forms a lubricating film in a bearing clearance, and wherein the lubricating oil or a base oil of the lubricating grease is a lubricating oil selected from among mixtures of poly-?-olefin or hydrogenated compound thereof and a defined phosphoric ester.

Abstract: A hydrodynamic type oil-impregnated sintered bearing includes a porous bearing body of sintered metal having a bearing surface in which hydrodynamic pressure generating grooves slating against an axial direction are provided. Lubricating oil or the base oil of lubricating grease to be impregnated into the bearing body is selected from among (a) mixtures of poly-?-olefin or hydrogenated compound thereof and ester and (b) ester. The ester is preferably polyol ester. In the cases of the lubricating grease, the thickener of the lubricating grease is preferably composed of urea compound. A plurality of bearing surfaces may be formed on the inner periphery of the bearing body so as to be separated from one another. The hydrodynamic type oil-impregnated sintered bearing may be suitably applied to a spindle motor for information equipment.

Abstract: Disclosed is lubricant base oil that is excellent in lubricity, sludge solubility, low viscosity, and low temperature characteristics and capable of realizing low volatility. The lubricant base oil contains as its main component a diester or triester synthesized from a divalent or trivalent carboxylic acid of 9 or less carbon atoms and a monovalent glycol ether such as an alkylene glycol monoalkyl ether of 3 to 25 carbon atoms and is useful as base oil for lubricating oil and grease. Di(hexyloxyethyl) adipate may be cited as an appropriate example of the diester.

Abstract: A plurality of object arrays in which a plurality of objects are sorted under a plurality of order conditions are generated. A display image is generated by sorting the objects in an order for each object array to line up in the first direction for each of the plurality of object arrays, selecting one object of a first object array of the plurality of object arrays as a reference object, and sorting the objects for each of the plurality of object arrays so that the reference object and objects corresponding to the reference object included in the object arrays other than the first object array line up in the second direction.

Abstract: There is provided a durable low-torque lubricating oil for bearings and fluid dynamic bearings, porous oil-impregnated bearings and hydrodynamic type porous oil-impregnated bearings suitable for use as bearings in small-sized spindle motors for information equipment. The lubricating oil composition comprising (A) a diester of a monovalent aliphatic alcohol containing 6-10 carbon atoms and a saturated aliphatic dicarboxylic acid containing 10 carbon atoms as base oil and (B) 3-20% by weight of a low-viscosity lubricating oil with a kinematic viscosity of less than 11 mm2/s at 40° C., a fluid dynamic pressure bearing unit or a porous oil-impregnated bearing unit containing said lubricating oil composition or a spindle motor provided with said bearing unit.

Abstract: Disclosed is a lubricating composition such as a lubricant, a lubricating grease, or a rust preventive oil for use in a torque limiter and a ball-and-roller bearing; the lubricating composition having chemical attack resistance for a synthetic resin molded product. The lubricating composition comprises as a base oil at least one synthetic saturated hydrocarbon oil selected from the group consisting of a poly-&agr;-olefin, and an ethylene-&agr;-olefin copolymer. When a phosphoric acid ester is used as a compounding agent, or at lease one lubricating grease selected from the group consisting of an urea compound, silica powder, and bentonite powder is mixed therein, the lubricating composition is a rust preventive oil using a metal salt of sulfonic acid and the like. The lubricating composition is suitably used for machine parts of a business machine including the synthetic resin molded product.

Abstract: There is provided a durable low-torque lubricating oil for bearings and fluid dynamic bearings, porous oil-impregnated bearings and hydrodynamic type porous oil-impregnated bearings suitable for use as bearings in small-sized spindle motors for information equipment. The lubricating oil composition comprising (A) a diester of a monovalent aliphatic alcohol containing 6-10 carbon atoms and a saturated aliphatic dicarboxylic acid containing 10 carbon atoms as base oil and (B) 3-20% by weight of a low-viscosity lubricating oil with a kinematic viscosity of less than 11 mm2/s at 40 ° C., a fluid dynamic pressure bearing unit or a porous oil-impregnated bearing unit containing said lubricating oil composition or a spindle motor provided with said bearing unit.

Abstract: Disclosed is a lubricating composition such as a lubricant, a lubricating grease, or a rust preventive oil for use in a torque limiter and a ball-and-roller bearing; the lubricating composition having chemical attack resistance for a synthetic resin molded product. The lubricating composition comprises as a base oil at least one synthetic saturated hydrocarbon oil selected from the group consisting of a poly-&agr;-olefin, and an ethylene-&agr;-olefin copolymer. When a phosphoric acid ester is used as a compounding agent, or at lease one lubricating grease selected from the group consisting of an urea compound, silica powder, and bentonite powder is mixed therein, the lubricating composition is a rust preventive oil using a metal salt of sulfonic acid and the like. The lubricating composition is suitably used for machine parts of a business machine including the synthetic resin molded product.