Abstract: The object of the present invention is to provide a water-base lubricating fluid or a water-base hydraulic fluid in place of an oily liquid which has been used as a lubricating oil or a hydraulic oil applied onto the operating part of a machine and a device. The lubricating fluid of the present invention comprises fluoride ion, hydrogencarbonate ion, and water-soluble alcohols or their derivatives.

Abstract: A metal chelate compound obtained from an azo compound of the following formula [a] or [b] and a metal salt: wherein each of A2 and A3 is a residue forming, together with the carbon atom and the nitrogen atom to which A2 or A3 is bonded, a heterocyclic ring which may have a substituent, B1 is a residue forming, together with the carbon atoms to which B1 is bonded, an aromatic or heterocyclic ring which may have a substituent, and Y is a C1-6 linear or branched alkyl group substituted by at least two fluorine atoms.

Abstract: A high-density optical disk comprises a transparent substrate having a guide groove having a depth of 100 to 200 nm, width of 0.2 to 0.4 &mgr;m arranged with a track pitch of 0.7 to 1.0 &mgr;m. A recording layer is made of an organic pigment exhibiting a specific main weight reduction in a thermogravimetric analysis and a specific exothermic peak in a differential thermal analysis.

Abstract: A sulfonamide compound of the formula (1): wherein X is a hydrogen atom, an alkyl or alkoxy group which may be substituted, or a halogen atom, Y Is an alkyl group having at least two fluorine atoms, and each of R1 and R2 which are independent of each other, is an alkyl group which may be substituted, or R1 may be bonded to X or R2 to form a ring.

Abstract: An optical recording medium comprising a transparent substrate and at least a recording layer containing an organic dye, a reflecting metal layer and a protective layer sequentially laminated on the substrate in this order, which has the following characteristics (a) to (c): (a) the substrate has a tracking groove with a track pitch of from 0.7 to 1.0 &mgr;m and the recording layer shows a modulation amplitude of EFM signal of at least 50% when recording is carried out by a laser beam with a wavelength of from 600 to 700 nm, and has a reflectance of from 45 to 65%; (b) in a thermogravimetric analysis of the dye, the inclination of the weight reduction to the temperature in the main weight reduction process is at least 2%/°C.; and (c) in the thermogravimetric analysis of the dye, the total weight reduction in the main weight reduction process is at least 25%.

Abstract: A wheel cover comprises a fixable side fixture fixably secured to the center of a wheel of a car, as to be able to position to the central part thereof; a movable side fixture pivoyably mounted to the central part of the fixable side fixturethrough a bearing; a wheel cover body in the shape of a disk mounted to the movable side fixture, having a space between the wheel; and a weight mounted to said movable side fixture or wheel cover body, in order to prevent to rotate the wheel cover body so that people can see the design drawn onto the wheel cover body because the rotating of the wheel cover body can be prevented if the tire rotates, moreover, the wheel cover is positioned the up and downward thereof and can be prevented to be unsightly design.