A lubricant composition is provided which comprises a base oil and hydroxytyrosol and/or esters thereof. Also provided is a lubricant composition in which the esters have a solubility in the base oil at 25° C. of at least 0.1 g/l. Further provided is a lubricant composition in which the esters are at least partly carboxylic acid esters comprising esters of hydroxytyrosol and C.sub.2-10 carboxylic acids.

A lubricant composition is provided which comprises a base oil and hydroxytyrosol and/or esters thereof. Also provided is a lubricant composition in which the esters have a solubility in the base oil at 25° C. of at least 0.1 g/l. Further provided is a lubricant composition in which the esters are at least partly carboxylic acid esters comprising esters of hydroxytyrosol and C.sub.2-10 carboxylic acids.

The invention provides a composition comprising at least the following: an oil, and at least one compound selected from Compounds 1 through 3, or a combination thereof, as described herein. The composition can be used to improve the high pressure, free-radical polymerizations of ethylene-based interpolymers, and to reduce polymer build-up in reciprocation devices throughout the process.

A phenol derivative of the present invention has a structure as represented by the formula (I):

##STR00001##

The functional groups are defined in the description. The phenol derivative can be used as the antioxidant in lubricating oil, lubricating grease, plastic, rubber, or can be used as the base oil of the lubricating oil and the lubricating grease and the antiwear additive of the lubricating oil and the lubricating grease.

A phenol derivative of the present invention has a structure as represented by the formula (I):

##STR00001##

The functional groups are defined in the description. The phenol derivative can be used as the antioxidant in lubricating oil, lubricating grease, plastic, rubber, or can be used as the base oil of the lubricating oil and the lubricating grease and the antiwear additive of the lubricating oil and the lubricating grease.

A phenol derivative of the present invention has a structure as represented by the formula (I): ##STR00001##
The functional groups are defined in the description. The phenol derivative can be used as the antioxidant in lubricating oil, lubricating grease, plastic, rubber, or can be used as the base oil of the lubricating oil and the lubricating grease and the antiwear additive of the lubricating oil and the lubricating grease.

A phenol derivative of the present invention has a structure as represented by the formula (I): ##STR00001##
The functional groups are defined in the description. The phenol derivative can be used as the antioxidant in lubricating oil, lubricating grease, plastic, rubber, or can be used as the base oil of the lubricating oil and the lubricating grease and the antiwear additive of the lubricating oil and the lubricating grease.

An object of the present invention is to provide an ester-based lubricating base oil for a fluid bearing that has a high viscosity index and excellent evaporation resistance, hydrolytic stability, and low-temperature fluidity. The present invention relates to a lubricating base oil for a fluid bearing containing a compound represented by general formula (1): ##STR00001##
wherein R.sup.1 represents a linear C.sub.2-C.sub.16 alkyl group, m represents an integer of 2 to 10, and n represents an integer of 4 to 14.

An object of the present invention is to provide an ester-based lubricating base oil for a fluid bearing that has a high viscosity index and excellent evaporation resistance, hydrolytic stability, and low-temperature fluidity. The present invention relates to a lubricating base oil for a fluid bearing containing a compound represented by general formula (1): ##STR00001##
wherein R.sup.1 represents a linear C.sub.2-C.sub.16 alkyl group, m represents an integer of 2 to 10, and n represents an integer of 4 to 14.

A lubricant for a medical device includes an anti-friction material and a radical scavenger.