Patent GB-593738-A (GB)
Title: Improvements in or relating to the prevention of oxidation in hydrocarbon oils
Filed: 1944-03-13
Abstract: A crankcase lubricant applicable also as a textile, cutting, or insulating oil, comprises a hydrocarbon oil containing a small quantity of an alkylated aromatic hydrocarbon having at least two different substituent groups, one of which is hydroxyl or sulph-hydryl and the other an inorganic acid radicle containing at least two of the elements sulphur, phosphorus and oxygen, the acid radicle being attached to the aromatic nucleus either directly or through a hydrocarbon radicle, and the replaceable hydrogen of both substituent groups being substituted by polyvalent metals. The aromatic hydrocarbon may be benzene, diphenyl or naphthalene, the alkyl substituent is preferably a branched chain alkyl group of 8 to 24 carbon atoms, such as the dimer, trimer, tetramer or pentamer of isobutylene, and the acid radicle may be a sulphonate, sulphate, sulphite, phosphate, phosphite, phosphonate, phosphonite, phosphinate or phosphinite.  The polyvalent metal may be a metal from Groups II, III, VIII or the right hand column of Group IV of the periodic table. The following compounds are specially mentioned, viz., the barium double salt of isododecyl phenol sulphide sulphonic acid, the calcium double salt of isododecyl phenol sulphonic acid, the barium double salt of isohexadecyl phenol sulphonic acid, the calcium double salt of a phenol sulphonic acid in which the phenol has been alkylated with a C16-C20 polymer of n-butene, the barium-zinc double salt of iso-eicosyl phenol sulphonic acid, the calcium double salt of isohexadecyl phenol sulphonic acid (prepared according to Specification 585,803), the tin double salt of isododecyl cresol sulphonic acid, the barium double salt of di-tert-amyl phenol sulphonic acid, the calcium-zinc double salt of isododecyl hydroxy-phenyl propane sulphonic acid, the calcium-barium double salt of bis-(di-isohexyl phenol monothiophosphoric acid) sulphide, the calcium double salt of a tetramethylbutyl phenol phosphoric acid, and the aluminium double salt of bis-(isohexadecyl phenol sulphonic acid) sulphide.  Any free valencies of metal constituents may be satisfied by attachment to similar organic groups or to each other, as in the formula <FORM:0593738/III/1> where M and M1 are the same or different metals selected from the above-mentioned groups, R1 and R2 are branched chain alkyl radicles, X is oxygen or sulphur, m, n, and x are small whole numbers, and the total number of carbon atoms in all the radicles R1 and R2 is not less than 16.  Other addition agents for lubricating oils may be added, including higher alcohols having preferably 12 to 20 carbon atoms such as stearyl alcohol.  The results of engine tests are given.  Metal double salts of alkyl phenol sulphonic, thiophosphoric, and phosphoric acids are usually prepared from the sodium salts of the phenol sulphonic acids (see Group IV) by neutralising first with aqueous sodium hydroxide to form the mono sodium sulphonate, then with alcoholic sodium hydroxide to make the double sodium salt, and then with calcium nitrate in acetone to give the calcium double salt.  The mono sodium salt may be converted to the double sodium salt by solution in xylene and treatment with finely divided solid caustic soda.  The calcium-zinc double salt of isododecyl hydroxyphenyl propane sulphonic acid may be prepared by sulphonating propane, chlorinating the sodium salt, condensing the product with phenol, and alkylating with isododecylene.  The sodium salt is converted to the zinc salt by double decomposition and the hydroxyl groups neutralised with calcium oxide or hydroxide to form a compound of the probable formula <FORM:0593738/III/2> To prepare a double salt of an alkylated phenol thiophosphoric acid, hydroquinone may be used as the starting material.  This is alkylated with triisobutylene to give isododecyl hydroquinone and the product partly neutralised with sodium hydroxide.  The sodium salt is converted to barium salt by double decomposition with a suitable inorganic barium salt.  The latter is then treated with P2S5 and zinc oxide to give the barium-zinc double salt of isododecyl phenol dithiophosphoric acid.  Specification 555,053 also is referred to.ALSO:Alkylated phenol sulphonic acids may be prepared by reacting phenol with an olefine or olefine polymer in hydrocarbon oil solution while gradually adding sulphuric acid under controlled temperature conditions, or by alkylating phenol in the presence of a catalyst other than sulphuric acid and then sulphonating the product.  Thus, phenol may be alkylated with diisobutylene in the presence of stannic chloride and HCl, or with a mixed butene polymer of 16 to 20 carbon atoms using aluminium chloride-hydrochloric acid catalyst.  The sodium salts are then prepared and these are converted to barium, zinc, calcium and other polyvalent metal salts by reaction with an appropriate inorganic salt.  The following compounds are mentioned: the barium double salt of isododecyl phenol sulphide sulphonic acid, the calcium double salt of isododecyl phenol sulphonic acid, the barium double salt of isohexadecyl phenol sulphonic acid, the calcium double salt of a phenol sulphonic acid in which the phenol has been alkylated with a C16-C20 polymer of n-butene, the barium-zinc double salt of iso-eicosyl phenol sulphonic acid, the calcium double salt of isohexadecyl phenol sulphonic acid (prepared according to Specification 585,803), the tin double salt of isododecyl cresol sulphonic acid, the barium double salt of di-tert-amyl phenol sulphonic acid, the calcium-zinc double salt of isododecyl hydroxy-phenyl propane sulphonic acid and the aluminium double salt of bis-(isohexadecyl phenol sulphonic acid) sulphide.  Any free valencies of metal constituents may be satisfied by attachment to similar organic groups or to each other, as in the formula <FORM:0593738/IV/1> where M and M1 are the same or different polyvalent metals, R1 and R2 are branched chain alkyl radicles, X is oxygen or sulphur, m, n and x are small whole numbers, and the total number of carbon atoms in all the radicles R1 and R2 is not less than 16.  Alkylated phenol thiophosphoric acids may be prepared, for example, in the case of barium-zinc double salt of isododecyl phenol dithiophosphoric acid, by alkylating hydroquinone with triisobutylene, partially neutralizing with sodium hydroxide to give the sodium mono salt of isododecyl hydroquinone, converting to the barium salt with an inorganic barium salt, and then treating with phosphorus pentasulphide and zinc oxide to give the barium-zinc double salt of isododecyl phenol dithiophosphoric acid.  Other compounds referred to are the calcium barium double salt of bis-(di-isohexyl phenol monothiophosphoric acid) sulphide and the calcium double salt of tetra-methyl butyl phosphoric acid.