Patent GB-748537-A (GB)
Title: Preparation of synthetic lubricating oils
Inventor: SHIMMIN JAMES DONALD
IPC: C07C69/34
Filed: 1954-08-12
Abstract: A salt of a phenol-aldehyde condensation product for use as an anti-lacquering agent with synthetic lubricating compositions (see Group III) is made as follows: 60 parts of para-tert.-octyl phenol are stirred into 260 parts of a solvent refined mineral lubricating oil containing 1 part of water, and 9.7 parts of calcium hydroxide and 10.1 parts of paraformaldehyde are added; the mixture is heated to 85 DEG  C., the temperature raised to 95 DEG  C. over 30 minutes and held at 95 DEG  C. for one hour and then filtered hot to yield a concentrate having a calcium content of 1.2 per cent.ALSO:Mixed esters suitable as synthetic lubricating oil are prepared by esterifying, in the presence of an esterification catalyst, 1 mol. of a mixture containing 15 to 90 mol. per cent of sebacic acid and 85 to 10 mol. per cent of adipic acid with 2 mols. of a mixture containing 90 to 7.5 mol. per cent of a branched chain octanol and 10 to 92.5 mol. per cent of a branched chain nonanol, preferably using a water entrainer such as benzene, toluene or xylene.  A modification comprises interesterifying a mixture of dioctyl adipate and dinonyl sebacate, a mixture of dinonyl adipate and dioctyl sebacate or a mixture of any three or all four of these esters, said octyl and nonyl groups being branched chain and the mixture being such that if considered as a mixture of adipic and sebacic acids and a mixture of octanol and nonanol, the proportions would be as above.  Typical alcohols are 2-isopropyl-3-methylbutanol, 2-ethylhexanol, 2,2,4 - trimethylpentanol, 1-methylheptanol, 2 - isopropyl - 3,3 - dimethylbutanol, 2,2,4,4-tetramethylpentanol, 3,3-dimethylheptanol, 3,3,5-trimethylhexanol, 3,5,5-trimethylhexanol, and mixtures of two or more thereof, or oxo alcohols obtained from heptenes and octenes. Reaction temperatures between 80 DEG  and 250 DEG  C. are suitable. Catalysts include sulphuric acid and aryl sulphonic acids such as p-toluenesulphonic acid.  The products may be washed with dilute alkali, heated under reduced pressure to remove free alcohol and treated with an adsorbent earth.  Minor proportions of glutaric, pimelic or azelaic acids and/or branched chain heptanols or decanols may be added to the reaction mixture in the coesterification or the corresponding esters may be added in the interesterification.  In Examples (1) or (2) a mixture of adipic and sebacic acids is esterified with a mixture of 3,5,5-trimethylhexanol and 2-ethylhexanol in the presence of sulphuric acid; (3) di-(3,5,5-trimethylhexyl) sebacate, di-(2-ethylhexyl) sebacate, and di-(3,5,5-trimethylhexyl) adipate are interesterified in the presence of sulphuric acid.  Suitable thickeners and anti-lacquering agents for addition to the mixed esters (see Group III) are (a) complex esters made by esterifying 1 mol. of tetraethyleneglycol, 2 mols. of sebacic acid and 2 mols. of 3,5,5-trimethylhexanol; (b) salts of the mixtures of alkylated hydroxybenzoic acids obtained (i) by reacting salicyclic acid or 4-hydroxybenzoic acid with a mixture of alkenes, such as one obtained by cracking paraffin-wax, or with a mixture of alcohols in the presence of Friedel Craft catalysts, or (ii) by alkylating a phenol with a mixture of alkenes, e.g. containing 14 to 18 carbon atoms, or alcohols and converting the alkyl phenols into alkyl salicylic acids by the Kolbe-Schmitt reaction; (c) salts of mixtures of alkyl phenols made by alkylation of phenol, cresol, 1- or 2-naphthol, cresol, xylenol, carvacrol or cardanol with a mixture of alkenes containing from 8 to 18 carbon atoms obtained by cracking paraffin wax, or with alkyl halides, alcohols or ethers.ALSO:A lubricating oil composition comprises mixed adipates and sebacates of a branched chain octanol, e.g. 2-ethylhexanol, and a branched chain nonanol, e.g. 3, 5, 5-trimethylhexanol, in such a proportion that, if considered as a mixture of acids and alcohols, it would contain a mixture of 15 to 90 mol per cent sebacic acid and 85 to 10 mol per cent of adipic acid, and a mixture of 90 to 7.5 mol per cent of the octanol and 10 to 92.5 mol per cent of the nonanol.  (For preparation see Group IV(b).)  Other suitable octanols and nonanols are specified.  Suitable thickeners for use with the lubricating composition are polymers or copolymers of esters of acrylic acid or a 2-alkylacrylic acid, and complex esters of a polyalkylene glycol, a saturated dicarboxylic acid and a saturated branched chain alkanol. Suitable anti-lacquering agents are the salts of aromatic carboxylic acids, e.g. benzoic, naphthoic and alkylated hydroxybenzoic acids, or of phenols, e.g. phenol, naphthols, cresols and higher alkylated phenols with a metal of Group II of the Periodic Table.  Phenols containing halogen, alkoxy, alkyl mercapto, and alkyl amine substituents may also be used.  Salts derived from the condensation products of hydrocarbon-substituted phenols with formaldehyde or acetaldehyde are particularly effective.  A concentrate of a calcium salt of a para-tert - octylphenol - paraformaldehyde condensation product in a solvent refined mineral lubricating oil is specified. (See Group IVa for preparation.)  As extreme pressure agents, trialkyl, triaryl or trialkaryl phosphates, such as triactyl or tricresyl phosphate, or haloalkylphosphonates such as monobutyl hydrogen trichloromethylphosphonate and its amine salts, are suitable. Antioxidants of the phenolic or amine type, such as alklated phenols and diphenols, phenyl-1-naphthylamine and phenothiazine and its alkyl and halogen substitution products may also be added. Specification 703,445 is referred to.