Patent GB-836855-A (GB)
Title: Magnesium containing organic compositions and process of preparing same
IPC: C10M159/20
Filed: 1958-05-14
Abstract: A stable dispersion of a basic magnesium-containing compound (believed to be magnesium carbonate) in an oil composition is prepared by (a) reacting magnesium with an excess of an alkanol containing less than 6 carbon atoms to form an alkanol-insoluble magnesium alkoxide, (b) forming an alkanol-soluble magnesium alkoxide-carbon dioxide complex by passing carbon dioxide through the magnesium alkoxide-alkanol mixture until the mixture is acid to alpha-naphthol benzein indicator, (c) mixing the complex with an oil containing an oil-soluble dispersing agent to form a homogeneous system and (d) heating the system to remove alkanol and decompose the complex, thereby producing a dispersion of an oil-insoluble magnesium compound whose particles have a diameter less than 0.25 micron. According to a modification of the process, the mixture derived from the reaction of magnesium and alkanol according to (a) is dispersed in an oil containing an oil-soluble dispersing agent and carbon dioxide is passed through the resulting dispersion until it is acid to alpha-naphthol benzein indicator, the dispersion of oil-insoluble magnesium compound being finally produced according to (d).  The oil may be a mineral, fatty or synthetic oil and may be diluted with a solvent such as an aliphatic or aromatic hydrocarbon or petroleum naphtha.  Synthetic oils mentioned are propylene polymers, polyoxypropylene glycol and esters thereof, alkyl esters of adipic or azelaic acid, diethyl ester of decanephosphonic acid and tricresyl phosphate.  The oil-soluble dispersing agent may be a sulphonate, an anionic organic phosphorus compound, a phosphorus sulphide-treated olefin, a phenol or metal phenate, a metal soap, a non-ionic surface-active agent or a cationic surface-active agent.  The sulphonates mentioned include alkyl, cycloalkyl, or alkaryl sulphonates, petroleum sulphonates, and substituted sulphonates such as diphenyl ether sulphonates, naphthalene disulphide sulphonates, diphenylamine sulphonates, dicetyl thianthrene sulphonates, dilauryl beta-naphthol sulphonates, dicapryl nitronaphthalene sulphonates, mono- and poly-chloro-substituted paraffin wax sulphonates and nitroso paraffin wax sulphonates.  The phenols mentioned include alkyl phenols and naphthols, polyhydric phenols and alkyl phenol sulphides.  The anionic phosphorus compounds may be organic acids of tri- or pentavalent phosphorus, the corresponding thio acids, or salts of these acids.  The phosphorus sulphide-treated olefins include the potassium - polyisobutylene - phosphorus sulphide products.  The soaps include metal salts of fatty acids, naphthenic acids, cycloalkane carboxylic acids and decahydronaphthalene carboxylic acids.  The non-ionic surface-active agents include polyoxyalkylene ethers and esters, while the cationic surface-active agents include fatty amines, imidazolines, oxazolines and quaternary ammonium salts.  Instead of using a sulphonate or soap as the dispersing agent, the corresponding acid may be employed and this will react with a portion of the basic magnesium-containing compound to form the sulphonate or soap in situ.  When the final dispersion is to be used as a lubricating composition, additional ingredients may be incorporated, such as zinc dithiophosphates, calcium/barium phenolate sulphides, methyl dichlorostearate, antifoaming agents, pour-point depressants and viscosity index improvers.  According to the examples, magnesium is reacted with methanol in step (a), while mineral oil solutions of various sulphonic acids, tall oil or tall oil fatty acids are added in step (c).