A lubricant material for assisting machining process comprising a polyethylene oxide-polypropylene oxide copolymer having a weight average molecular weight of 5.0×10.sup.4 or more and 2.0×10.sup.5 or less.

A lubricant material for assisting machining process comprising a polyethylene oxide-polypropylene oxide copolymer having a weight average molecular weight of 5.0×10.sup.4 or more and 2.0×10.sup.5 or less.

A lubrication board includes a substrate; and a lubrication layer disposed on a surface of the substrate, wherein the lubrication layer comprises a polymer expressed by formula (I) below,

##STR00001##

wherein R.sub.1 is selected from a substituted or unsubstituted C.sub.2-C.sub.18 alkyl or C.sub.2-C.sub.18 aryl; R.sub.2 is selected from a substituted or unsubstituted C.sub.2-C.sub.18 alkyl or C.sub.2-C.sub.18 alkyl which is interrupted by —O—; R.sub.3 is selected from —NH— or —S—; R.sub.4 is selected from —NH.sub.2, —OH or —SH; and n, p and q are positive integers ranging from 2 to 20000.

A lubricant material for assisting machining process comprising fullerene.

Described herein are methods of stabilizing the beta hydrogen of glycerol based esters by the insertion of alkoxy groups to significantly improve the thermal, oxidative, and hydrolytic stability of the ester and allow for controlling the molar density of esters bonds in the lubricants to maximize hydrolytic stability while maintaining biodegradability and further improving performance properties.

The invention relates to a use of a lubricant comprising a polyalkylene glycol for reducing white etching cracks in lubricated metal surfaces; and to a method for reducing white etching cracks in lubricated metal surfaces comprising the steps of lubricating the metal surfaces with a lubricant comprising the polyalkylene glycol.

The invention relates to a use of a lubricant comprising a polyalkylene glycol for reducing white etching cracks in lubricated metal surfaces; and to a method for reducing white etching cracks in lubricated metal surfaces comprising the steps of lubricating the metal surfaces with a lubricant comprising the polyalkylene glycol.

A composition comprising water and a polyalkylene glycol having an allyl content of less than 20 ueq/g, which composition has reduced foaming properties and preferably a biodegradability of at least 60% as determined using OECD 301F. The polyalkylene glycol can be made by forming a first intermediate comprising an oxypropylene block by reacting propylene oxide with a polyol initiator in the presence of a Double Metal Cyanide catalyst, and then reacting the first intermediate with ethylene oxide in the presence of a KOH catalyst.

A composition comprising water and a polyalkylene glycol having an allyl content of less than 20 ueq/g, which composition has reduced foaming properties and preferably a biodegradability of at least 60% as determined using OECD 301F. The polyalkylene glycol can be made by forming a first intermediate comprising an oxypropylene block by reacting propylene oxide with a polyol initiator in the presence of a Double Metal Cyanide catalyst, and then reacting the first intermediate with ethylene oxide in the presence of a KOH catalyst.

The present invention relates to a lubricating composition, intended for a refrigerant system comprising a gas compression circuit, comprising: at least one first polyalkylene glycol exhibiting a hydroxyl number strictly of greater than 50 mg KOH/g and a kinematic viscosity, measured at 100° C. according to the standard ASTM D445, ranging from 5 to 10 mm.sup.2/s, and at least one second polyalkylene glycol with a kinematic viscosity, measured at 100° C., ranging from 100 to 500 mm.sup.2/s, said polyalkylene glycols A and B being present in a PAG(s) A/PAG(s) B ratio by weight of between 60/40 and 99/1. It also relates to the employment of such a lubricating composition in a refrigerant system comprising a gas compression circuit, in particular for an automobile air conditioning system, in combination with a coolant based on hydrocarbon compounds, such as R134a and/or HFO-1234yf.