GB680233A - Improvements in or relating to sealing devices for joints - Google Patents

Abstract

Complex phosphate esters suitable for use as synthetic lubricants are obtained by reacting one or more saturated aliphatic monohydric alcohols R1OH, R2OH, R3OH and R4OH under esterification conditions with an intermediate ester having the basic structure: <FORM:0680233/IV (b)/1> said intermediate ester being formed by the reaction of a glycol R(OH)2 with phosphorus oxychloride or with an inorganic phosphorus compound which gives such a phosphate ester on reaction with said glycol, the resulting complex ester having the formula <FORM:0680233/IV (b)/2> where R is a saturated aliphatic hydrocarbon radical of 2 to 18 carbon atoms or a radical consisting of a series of saturated aliphatic hydrocarbon groups linked by at least one ether-oxygen and/or thioether sulphur atom, each such hydrocarbon radical so linked containing a chain of at least two carbon atoms and there being at least 2 carbon atoms between each phosphate group and the nearest oxygen or sulphur atom, the total number of carbon, oxygen and sulphur atoms in the entire radical being from 5 to 80, and the number of sulphur atoms in the radical being not greater than 2; and R1, R2, R3 and R4 are saturated aliphatic hydrocarbon radicals containing 1 to 20 carbon atoms or radicals consisting of a series of saturated aliphatic hydrocarbon radicals linked through 1 to 5 ether oxygen and/or thioether sulphur atoms, there being a chain of at least 2 carbon atoms between each phosphate group and the nearest oxygen or sulphur atom and between successive oxygen and/or sulphur atoms, the total number of carbon, oxygen and sulphur atoms in each of the radicals R1, R2, R3 and R4 being from 4 to 20 and the total number of sulphur atoms in each radical being not greater than 2; and in which the components are so chosen that the molecular weight of the complex phosphate ester is at least 300. The glycols employed include ethylene glycol, propylene glycol, butylene glycols, pinacone, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, di- and tri-ethylene glycol, polyethylene glycols of the formula: HO(CH2CH2O)nCH2CH2OH, where n is 1 t 26 and polypropylene glycols of the formula <FORM:0680233/IV (b)/3> where either R1 or R2 is a methyl group and the other is hydrogen and where n is 1 to 19; thiodiglycol and 1,2-bis-(2-hydroxyethylmercapto) ethane and bis-[2-(2-hydroxyethoxy) ethyl] sulphide. Several saturated monohydric alcohols are specified including simple alcohols such as methyl and cetyl alcohols; mono-alkyl ethers of ethylene glycol; mono-alkyl ethers of diethylene glycol and of propylene, dipropylene and tripropylene glycols; b -n-butylmercapto-ethanol, b - tert. - octylmercapto - ethanol, b - n - dodecylmercaptoethanol; monoalkylthioethers of propylene glycol; n-butylmercaptoethoxyethanol, tert.-octylmercaptoethoxyethanol, n-dodecylmercaptoethoxyethanol, n-butylmercapto propoxypropanol; and " Oxo " alcohols which may be derived from di-isobutylene and C7 olefins. The esters may be obtained by reacting two moles. of phosphorus oxychloride with one mole. of a glycol in an inert liquid medium and then reacting the partial ester formed with 4 moles. of the monohydric alcohol or mixture of monohydric alcohols. A table is given showing the properties as lubricants of esters prepared from phosphorus oxychloride and the following glycols and monohydric alcohols: ethylene glycol and 2-ethylhexanol, and ethylene glycol mono-n-butyl ether, respectively; triethylene glycol and 2-ethyl hexanol, C8 " Oxo " alcohol, and butyl carbitol, respectively; and thiodiglycol and C8 " Oxo " alcohol. These esters are prepared by adding the glycol to a mixture of phosphorus oxychloride, pyridine, and benzene, maintaining the temperature at below 10 DEG C. and then adding the monohydric alcohol and refluxing the mixture. The Specification as open to inspection under Sect. 91 states that unsaturated monohydric alcohols, e.g. oleyl alcohol, may be used to prepare the esters. This subject-matter does not appear in the Specification as accepted.