A metal detergent and a preparation method thereof and a lubricant oil containing the metal detergent. The metal detergent is sulfurized calcium alkyl phenolate, the method for preparing the metal detergent includes the following steps: a) mixing alkyl phenol, a calcium source and base oil to obtain a mixed solution; b) mixing the mixed solution, ethylene glycol and a sulfur source to carry out sulfurization reaction to obtain a sulfurization reaction solution; c) implementing carbonation reaction between the sulfurization reaction solution and CO.sub.2 to obtain a carbonation reaction solution; and d) extracting the carbonation reaction solution with a solvent, upon refining, to obtain sulfurized calcium alkyl phenolate; wherein the solvent includes solvent oil, water and oxygenous derivative of hydrocarbon. Experimental results show that the content of free alkyl phenol is below 1.5 wt % in the sulfurized calcium alkyl phenolate prepared using the preparation method provided by the present application.

The present patent application relates to the use, as detergent additive in a lubricating composition intended for a marine engine, of at least one spiro compound of formula (I)

##STR00001## in which M is an atom chosen from boron and aluminum; n1 and n2 have, independently of one another, the value 0, 1 or 2; and R represent, independently of one another, a hydrocarbon group comprising from 1 to 50 carbon atoms, in particular from 5 to 20 carbon atoms.

It also relates to the use of said spiro compound as additive in a lubricating composition intended for a marine engine, for improving the stability to oxidation of said lubricating composition.

Finally, it relates to a lubricating composition intended for the lubrication of a marine engine, comprising one or more base oils and at least one spiro compound of formula (I), and also to a process of lubrication of a marine engine employing such a composition.

The present patent application relates to the use, as detergent additive in a lubricating composition intended for a marine engine, of at least one spiro compound of formula (I)

##STR00001## in which M is an atom chosen from boron and aluminum; n1 and n2 have, independently of one another, the value 0, 1 or 2; and R represent, independently of one another, a hydrocarbon group comprising from 1 to 50 carbon atoms, in particular from 5 to 20 carbon atoms.

It also relates to the use of said spiro compound as additive in a lubricating composition intended for a marine engine, for improving the stability to oxidation of said lubricating composition.

Finally, it relates to a lubricating composition intended for the lubrication of a marine engine, comprising one or more base oils and at least one spiro compound of formula (I), and also to a process of lubrication of a marine engine employing such a composition.

Sulfurized calcium phenate detergents having a reduced unsulfurized alkyl-substituted phenol content are made by: (A) providing, made from an unsulfurized alkyl-substituted phenol, a sulfurized calcium phenate detergent that, optionally, may have been further reacted with carbon dioxide; (B) adding to the detergent from 1 to 100 mass %, based on the mass of the detergent, of an organic solvent that has a boiling point of above 100 C. and below the boiling point of the unsulfurized alkyl-substituted phenol; and (C) removing the organic solvent from the detergent thereby to reduce the unsulfurized alkyl-substituted phenol content.

A sulfurized alkaline earth metal (e.g., calcium) dodecylphenate is prepared by reacting (i) dodecylphenol with (ii) calcium hydroxide or calcium oxide in an amount of about 0.3 to about 0.7 moles per mole of dodecylphenol charged and (iii) an alkylene glycol in an amount of about 0.13 to about 0.6 moles per mole of dodecylphenol charged; and reacting the product of the first step with sulfur in an amount of about 1.6 to about 3 moles per mole of dodecylphenol charged; and thereafter optionally reacting the product with additional calcium hydroxide or calcium oxide and with carbon dioxide so as to form an overbased phenate. The product thus prepared has reduced levels of monomeric dodecylphenol.

A sulfurized alkaline earth metal (e.g., calcium) dodecylphenate is prepared by reacting (i) dodecylphenol with (ii) calcium hydroxide or calcium oxide in an amount of about 0.3 to about 0.7 moles per mole of dodecylphenol charged and (iii) an alkylene glycol in an amount of about 0.13 to about 0.6 moles per mole of dodecylphenol charged; and reacting the product of the first step with sulfur in an amount of about 1.6 to about 3 moles per mole of dodecylphenol charged; and thereafter optionally reacting the product with additional calcium hydroxide or calcium oxide and with carbon dioxide so as to form an overbased phenate. The product thus prepared has reduced levels of monomeric dodecylphenol.

The present disclosure provides a method for preparing a sulfurized alkyl phenate product to achieve a high sulfurization ratio of sulfurized alkyl phenate to unsulfurized alkyl phenate/phenol in the context of a neutralized and optionally overbased additive. The sulfurized alkyl phenate product is obtained by sulfurizing an alkyl phenol with a sulfur chloride blend that includes about 40 to about 75 weight percent of sulfur dichloride.

The present disclosure provides a method for preparing a sulfurized alkyl phenate product to achieve a high sulfurization ratio of sulfurized alkyl phenate to unsulfurized alkyl phenate/phenol in the context of a neutralized and optionally overbased additive. The sulfurized alkyl phenate product is obtained by sulfurizing an alkyl phenol with a sulfur chloride blend that includes about 40 to about 75 weight percent of sulfur dichloride.

A metal detergent and a preparation method thereof and a lubricant oil containing the metal detergent. The metal detergent is sulfurized calcium alkyl phenolate, the method for preparing the metal detergent includes the following steps: a) mixing alkyl phenol, a calcium source and base oil to obtain a mixed solution; b) mixing the mixed solution, ethylene glycol and a sulfur source to carry out sulfurization reaction to obtain a sulfurization reaction solution; c) implementing carbonation reaction between the sulfurization reaction solution and CO.sub.2 to obtain a carbonation reaction solution; and d) extracting the carbonation reaction solution with a solvent, upon refining, to obtain sulfurized calcium alkyl phenolate; wherein the solvent includes solvent oil, water and oxygenous derivative of hydrocarbon. Experimental results show that the content of free alkyl phenol is below 1.5 wt % in the sulfurized calcium alkyl phenolate prepared using the preparation method provided by the present application.

A metal detergent and a preparation method thereof and a lubricant oil containing the metal detergent. The metal detergent is sulfurized calcium alkyl phenolate, the method for preparing the metal detergent includes the following steps: a) mixing alkyl phenol, a calcium source and base oil to obtain a mixed solution; b) mixing the mixed solution, ethylene glycol and a sulfur source to carry out sulfurization reaction to obtain a sulfurization reaction solution; c) implementing carbonation reaction between the sulfurization reaction solution and CO.sub.2 to obtain a carbonation reaction solution; and d) extracting the carbonation reaction solution with a solvent, upon refining, to obtain sulfurized calcium alkyl phenolate; wherein the solvent includes solvent oil, water and oxygenous derivative of hydrocarbon. Experimental results show that the content of free alkyl phenol is below 1.5 wt % in the sulfurized calcium alkyl phenolate prepared using the preparation method provided by the present application.