The fluorine-containing ether compound is represented by the following formula (1): R.sup.1—R.sup.2—CH.sub.2—R.sup.3—CH.sub.2—R.sup.4. In the formula (1), R.sup.1 is represented by the following formula (2), R.sup.2 is represented by the following formula (3), R.sup.3 is a perfluoropolyether chain, and R.sup.4 is an organic end group different from R.sup.1—R.sup.2— and contains two or three polar groups, wherein each polar group is bonded to a different carbon atom, and the carbon atoms to which the polar groups are bonded are bonded to one another via a linking group containing a carbon atom to which the polar group is not bonded. In the formula (2), r is 1 to 3. In the formula (3), w is 2 or 3. ##STR00001##

The fluorine-containing ether compound is represented by the following formula (1): R.sup.1-R.sup.2—CH.sub.2—R.sup.3—CH.sub.2—R.sup.4. In the formula (1), R.sup.1 is represented by the following formula (2), R.sup.2 is represented by the following formula (3), R.sup.3 is a perfluoropolyether chain, and R.sup.4 is an organic end group different from R.sup.1-R.sup.2- and contains two or three polar groups, wherein each polar group is bonded to a different carbon atom, and the carbon atoms to which the polar groups are bonded are bonded to one another via a linking group containing a carbon atom to which the polar group is not bonded. In the formula (2), r is 1 to 3. In the formula (3), w is 2 or 3.

##STR00001##

A composition comprising an oil of lubricating viscosity and a compound represented by formula (I) wherein: R.sup.1 and R.sup.2 are each independently a hydrocarbyl group containing from about 4 to about 18 carbon atoms; p and q are each independently 0 or an integer from 1 to 3, and the sum of p and q is 1, 2, 3, 4, 5, or 6. The composition is effective at swelling seals. ##STR00001##

Provided are a lubricant whereby particles including a fluororesin can be dispersed and adhered to the surface of an object without the use of a fluorine-based oil as a base oil, an electrical contact having such a lubricant on the surface thereof, and a connector terminal and a wire harness provided with such an electrical contact. The present invention provides a lubricant containing a base oil and resin particles including a trifluoroethylene resin, the content of the resin particles being more than 10 mass % with respect to the mass of the base oil. The present invention also provides an electrical contact 1 which has a metal material as a base material 11 and which electrically contacts another electroconductive member 2, the electrical contact 1 having a layer 14 of the abovementioned lubricant on the surface of the base material. The present invention furthermore provides a connector terminal having the abovementioned electrical contact 1 in a portion thereof for making electrical contact with a mating connector terminal. The present invention also provides a wire harness having the connector terminal.

The object of the present invention is to provide a foreign substance removing lubricant composition having high foreign substance removing effects and being capable of improving the lubricating properties as compared to conventional lubricant compositions, a foreign substance removing lubricant composition applied member, and a method for using the foreign substance removing lubricant composition. The foreign substance removing lubricant composition of the present invention comprises a perfluoroalkyl group containing compound (S) having a perfluoroalkyl group or a fluoropolyether containing compound. As a result, foreign substance removing effects can be enhanced, and the lubricating properties can be improved as compared to the conventional lubricant compositions.

A solution for processing machines includes a lubricating base including polyalkylene glycol, a fluorine-based surfactant or a cationic surfactant, and water. The lubricating base includes at least one of a polyoxyethylene/polyoxypropylene reverse block, an ethylenediamine polyoxyalkylene condensate, polyoxyethylene polyoxypropylene glycol, and an ethylene oxide propylene oxide polymer, as polyalkylene glycol.

Disclosed is a component-replaceable water ring vacuum pump in which inner components within a head unit may be disassembled and replaced without separation of the head unit from a main body, thus shortening an operation time and improving operation efficiency through prevention of leakage of an inner liquid during a replacement process. The water ring vacuum pump includes a main body provided with a shaft, a rotor rotated together with the shaft within the main body, a head unit coupled to both sides of the main body, a guide bearing provided within the head unit, and a mechanical seal configured to block inner gas. A bearing bracket to support the guide bearing is detachably fastened to one side of the head unit by a bolt, and an inner cap and an outer cap are assembled to the inner and outer surfaces of the bearing bracket by fixing bolts.

A composition comprising an oil of lubricating viscosity and a compound represented by formula (I) wherein: R.sup.1 and R.sup.2 are each independently a hydrocarbyl group containing from about 4 to about 18 carbon atoms; p and q are each independently 0 or an integer from 1 to 3, and the sum of p and q is 1, 2, 3, 4, 5, or 6. The composition is effective at swelling seals.

##STR00001##

This invention provides a threaded connection for pipe or tube that has a non-sticky surface and that suppresses the occurrence of rust and exhibits excellent galling resistance and airtightness even in an extremely low temperature environment without using compound grease, a method of producing the same, and a composition for forming a solid lubricating coating on the threaded connection. A solid lubricating coating (24) formed from a composition containing a binder, a fluorine addition agent, a solid lubricant and a rust proof addition agent is coated as a topmost surface treatment coating on a contact surface of at least one of a pin and a box. Even when exposed to an extremely low temperature environment, the solid lubricating coating (24) can maintain adhesiveness and exhibit a lubricating function, can suppress the occurrence of galling of a threaded connection, and can also secure airtightness after fastening.

Disclosed is a component-replaceable water ring vacuum pump in which inner components within a head unit may be disassembled and replaced without separation of the head unit from a main body, thus shortening an operation time and improving operation efficiency through prevention of leakage of an inner liquid during a replacement process. The water ring vacuum pump includes a main body provided with a shaft, a rotor rotated together with the shaft within the main body, a head unit coupled to both sides of the main body, a guide bearing provided within the head unit, and a mechanical seal configured to block inner gas. A bearing bracket to support the guide bearing is detachably fastened to one side of the head unit by a bolt, and an inner cap and an outer cap are assembled to the inner and outer surfaces of the bearing bracket by fixing bolts.