Abstract: The use of magnesium oxide of specified, low, reactivity in a process for the production of overbased magnesium sulphonates, together with the introduction of water and an alcohol, into the reaction mixture during carbonation, makes it possible to prepare high base number products which have very low post carbonation sediments and which can be purified by rapid filtration.

Abstract: A new overbased metal sulphonate composition comprises a mixture of (A) at least one long chain alkyl aryl sulphonate containing an average number of at least 40 carbon atoms in the alkyl residue and (B) at least one medium long chain alkyl aryl sulphonate containing an average number of 10 to 33 carbon atoms in the alkyl residue. The composition is useful as an additive to lubricant oil.

Abstract: A new overbased metal sulphonate composition comprises a mixture of (A) at least one long chain alkyl aryl sulphonate containing an average number of at least 40 carbon atoms in the alkyl residue and (B) at least one medium long chain alkyl aryl sulphonate containing an average number of 10 to 33 carbon atoms in the alkyl residue. The composition is useful as an additive to lubricant oil.

Abstract: Overbased magnesium sulphonates having increased resistance to interactions are prepared from sulphonic acids prepared from alkylates with long and medium chain alkyl groups. Compositions comprising such overbased magnesium sulphonate are particularly suitable for use in combination with high molecular weight dispersants and/or friction modifiers. Stable sediment-free lubricating oil compositions (including lubricants and concentrates therefor) can be prepared which can meet SG quality and the Tier II fuel economy requirements.

Abstract: Improved stability of overbased phenates, particularly when formulated with overbased sulphonates, as well as improved foaming tendency and viscosity is obtained by treating the overbased phenate, either during or subsequent to the overbasing process, with from 0.1 to 10 wt. %, preferably 2 to 6 wt. %, of a carboxylic acid with a C.sub.10 to C.sub.24 unbranched segment, e.g. behenic acid.

Abstract: A magnesium phenate is prepared by a process which comprises reacting (1) magnesium oxide, magnesium hydroxide, magnesium carbonate, magnesium bicarbonate or a magnesium carboxylate with (2) a phenol, a methylene bis-phenol or a sulphurised phenol in the presence of (3) a solvent comprising an organic compound containing one or more alcoholic hydroxyl groups e.g. an alkoxy alcohol and (4) a promoter selected from a ketone, diketone such as .alpha. or .beta. diketone, aldehyde or carboxylic acid and (5) optionally a diluent oil. This magnesium phenate may be used as a detergent for a lubricating oil.

Abstract: A lubricating oil composition having improved properties comprises a major proportion by weight of a lubricating oil, a dispersant compound, from 0.01 to 0.5 wt % phosphorus and zinc and 5 to 500 parts per million of copper, and additive concentrates for blending with oil to produce such lubricating oil compositions.

Abstract: A process for making an oil solution of a highly basic alkali metal compound which comprises(a) heating alkali metal hydroxide with an alkoxyalkanol and a solvent to remove water as an azeotrope with alkoxyalkanol and said solvent;(b) adding to the mixture surfactant;(c) thereafter introducing carbon dioxide into the reaction mixture so as to react with the basic compounds therein;(d) hydrolysing the reaction mixture; and(e) removing solvent by distillation,base oil being added to the process during one of steps (b), (c), (d) and (e) so that the desired product is obtained.

Abstract: Oil soluble basic magnesium sulphonates useful as lubricating oil additives are prepared by blowing carbon dioxide through a mixture of sulphonic acid or its sulphonate, magnesium oxide, a hydrocarbon solvent, water, a C.sub.3 to C.sub.6 ketone and a reaction promoter.

Abstract: Improved stability of overbased phenates, particularly when formulated with overbased sulphonates, as well as improved foaming tendency and viscosity is obtained by treated the overbased phenate, either during or subsequent to the overbasing process, with from 0.1 to 10 wt. %, preferably 2 to 6 wt. %, of a carboxylic acid with a C.sub.10 to C.sub.24 unbranched segment, e.g. behenic acid.