The present invention relates to a lubricating composition comprising a detergent additive derived from raw cashew nut shell liquid. The invention also provides a process for preparing the additive and the use of the lubricating composition in a mechanical device.

The present invention relates to a lubricating composition comprising a detergent additive derived from raw cashew nut shell liquid. The invention also provides a process for preparing the additive and the use of the lubricating composition in a mechanical device.

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.

The present invention provides a grease composition or a lubricating oil composition which is capable of effectively preventing hydrogen brittleness-caused peeling from occurring on a rolling surface of a rolling bearing, is excellent in durability in a high temperature and speed operation, and can be used for a long time. A grease-packed bearing (1) has an inner ring (2), an outer ring (3), and a plurality of rolling elements (4). A sealing member (6) for sealing a grease composition (7) is provided at openings (8a) and (8b) disposed at both axial ends of the inner ring (2) and the outer ring (3). The grease composition (7) includes a base grease composed of a base oil and a thickener and an additive added to the base grease. The additive contains at least one compound selected from among plant-derived polyphenolic compounds and compounds formed by decomposition thereof. The above-described compounds include tannin, gallic acid, ellagic acid, chlorogenic acid, caffeic acid, curcumin, quercetin, and quinic acid.

The present invention provides a grease composition or a lubricating oil composition which is capable of effectively preventing hydrogen brittleness-caused peeling from occurring on a rolling surface of a rolling bearing, is excellent in durability in a high temperature and speed operation, and can be used for a long time. A grease-packed bearing (1) has an inner ring (2), an outer ring (3), and a plurality of rolling elements (4). A sealing member (6) for sealing a grease composition (7) is provided at openings (8a) and (8b) disposed at both axial ends of the inner ring (2) and the outer ring (3). The grease composition (7) includes a base grease composed of a base oil and a thickener and an additive added to the base grease. The additive contains at least one compound selected from among plant-derived polyphenolic compounds and compounds formed by decomposition thereof. The above-described compounds include tannin, gallic acid, ellagic acid, chlorogenic acid, caffeic acid, curcumin, quercetin, and quinic acid.

The invention provides a lubricating composition containing an aromatic compound and an oil of lubricating viscosity. The invention further relates to the use of the lubricating composition in an internal combustion engine. The invention further relates to the use of the aromatic compound as an antiwear agent.

The invention provides a lubricating composition containing an aromatic compound and an oil of lubricating viscosity. The invention further relates to the use of the lubricating composition in an internal combustion engine. The invention further relates to the use of the aromatic compound as an antiwear agent.

A bridged alkaline earth metal alkylphenate having reduced monomeric alkylphenol is prepared by reacting (a) a 4-alkylphenol, unsubstituted at the ortho positions, (b) an alkaline earth metal oxide or hydroxide, (c) a bridging agent comprising sulfur or a carbonyl compound of 1 to about 6, or to 4 or to 2, carbon atoms, and (d) a 2,6-dialkylphenol. The amount of the 2,6-dialkylphenol is 0.05 to 3 moles per 1 mole of the 4-alkylphenol; if there is a molar excess of the 2,6-dialkylphenol, then the excess is added after initial reaction.

A bridged alkaline earth metal alkylphenate having reduced monomeric alkylphenol is prepared by reacting (a) a 4-alkylphenol, unsubstituted at the ortho positions, (b) an alkaline earth metal oxide or hydroxide, (c) a bridging agent comprising sulfur or a carbonyl compound of 1 to about 6, or to 4 or to 2, carbon atoms, and (d) a 2,6-dialkylphenol. The amount of the 2,6-dialkylphenol is 0.05 to 3 moles per 1 mole of the 4-alkylphenol; if there is a molar excess of the 2,6-dialkylphenol, then the excess is added after initial reaction.