Provided is a lubricant composition having small shear rate dependence of its apparent viscosity. The lubricant composition includes a perfluoropolyether as a base oil, and fluorine resin particles as a thickener. The lubricant composition further includes a fluorine-containing polymer having a tetrafluoroethylene structure under a state in which the polymer is dissolved in the perfluoropolyether.

The present invention concerns a coolant, present as an emulsion in the form of a concentrate, for machining fiber-reinforced plastics and material combinations containing fiber-reinforced plastics and metals; furthermore, the present invention also concerns a coolant, present as a solution in the form of concentrate, for machining fiber-reinforced plastics.

An additive composition for a hydraulic fluid, or a heat transfer fluid, comprises one or more phosphate esters derived from the esterification of phosphoric acid and one or more monomer glycols containing up to 18 carbon atoms, or combinations thereof. In addition, the additive composition may comprise one or more corrosion inhibitors selected from the group consisting of dicarboxylic acids, alkanolamines or combinations thereof; one or more antioxidants including selected from the group consisting of one or more organosulfur compounds, one or inorganic oxyanion salts or combinations thereof; and, one or more surfactants.

An object of an aspect of the present invention is to provide: a lubricant excellent in adsorbability on the surface of a magnetic disk and in contamination resistance; and a magnetic disk which uses the lubricant and which is excellent in durability. The lubricant in accordance with an aspect of the present invention contains a fluoropolyether compound having, at a terminal thereof, a hydroxyalkenyl group or a hydroxyalkynyl group.

The composition according to the present embodiment is a composition for forming a lubricant coating layer on a threaded connection for pipes or tubes, and contains Cr.sub.2O.sub.3, a metal soap, a wax and a basic metal salt of an aromatic organic acid. The threaded connection for pipes or tubes according to the present embodiment includes a pin and a box. The pin and the box each include a contact surface including a threaded portion. The threaded connection for pipes or tubes includes, as an outermost layer, a lubricant coating layer formed from the aforementioned composition on at least one of the contact surfaces of the pin and the box.

The present invention relates to a composition suitable to be used as working fluid, said composition being in the form of a solution and comprising at least one (per)fluoropolyether polymer [polymer (P)] and at least one amorphous polymer [polymer (F)].

An additive composition for a hydraulic fluid, or a heat transfer fluid, comprises one or more phosphate esters derived from the esterification of phosphoric acid and one or more monomer glycols containing up to 18 carbon atoms, or combinations thereof. In addition, the additive composition may comprise one or more corrosion inhibitors selected from the group consisting of dicarboxylic acids, alkanolamines or combinations thereof; one or more antioxidants including selected from the group consisting of one or more organosulfur compounds, one or inorganic oxyanion salts or combinations thereof; and, one or more surfactants.

The composition according to the present embodiment is a composition for forming a lubricant coating layer on a threaded connection for pipes or tubes, and contains Cr.sub.2O.sub.3, a metal soap, a wax and a basic metal salt of an aromatic organic acid. The threaded connection for pipes or tubes according to the present embodiment includes a pin and a box. The pin and the box each include a contact surface including a threaded portion. The threaded connection for pipes or tubes includes, as an outermost layer, a lubricant coating layer formed from the aforementioned composition on at least one of the contact surfaces of the pin and the box.

A hydraulic lubricating oil composition is provided which contains a synergistic mixture of three phosphorous antiwear components in order to provide good thermal stability and good demulsibility to the lubricating oil composition.

Provided are: a lubricating oil composition that contains a base oil (A) containing an alkylnaphthalene (A1) and an ester compound (A2), wherein the content ratio of the component (A1) to the component (A2) [(A1)/(A2)] is 15/85 to 85/15 as a ratio by mass, and a tenter device using the lubricating oil composition. The lubricating oil composition has a small evaporation loss, has a suppressed amount of evaporation, maintains good fluidity and hardly causes adherence of residue even in long-term use in high-temperature environments.