Patent GB-732086-A (GB)
Title: Complex formal lubricating composition
IPC: C10M169/00
Filed: 1953-07-22
Abstract: Synthetic lubricating compositions comprise complex formals of general formula <FORM:0732086/IV (b)/1> wherein A and B are C1 to C60 organic groups, x and n are integers not less than 2 and y is an integer, the total number of carbon atoms in the molecule being from 20 to 130.  The lubricants have good viscosity properties at high and low temperatures, and low rates of formation of combustion chamber deposits.  The complex formals are prepared by conventional methods using three lines of approach: (I) All the reactants (i.e. the required alcohol, the required glycol and formaldehyde) may be mixed in the reaction zone, in the proportions in which they appear in the product molecules of the invention, and heated to reflux temperature in a water-entraining agent such as hexane or heptane.  After recovery of the theoretical amount of water, the product is washed free of any acid catalyst and stripped free of unreacted components; (II) x moles of a glycol are reacted with x-1 moles of formaldehyde to obtain the central portion of the complex formal, i.e. <FORM:0732086/IV (b)/2> The hemiformal of the alcohol, i.e. R-O-CH2-OH is formed separately, the materials are mixed, heated to reflux temperature and treated as in (I); (III) the hemiformal of the chosen alcohol is first made by heating equal moles of the alcohol and formaldehyde.  The desired molar proportions of a glycol and formaldehyde are added and the mixture reacted to form the "hydroxy complex" represented by R-O-[CH2-O-(CnH2nO)y]xH and two moles of this reacted with one mole of formaldehyde.  Extensive lists of compounds containing alcoholic hydroxyl groups, which are used to prepare the formals, are given.  The main types with examples are (1) Unsubstituted alcohols: monohydric aliphatic, e.g. propyl alcohol, decyl alcohol, crotyl alcohol, C3 to C20 "Oxo" alcohols; monohydric aromatic, e.g. benzyl alcohol, cinnamyl alcohol; polyhydric, e.g. 1 : 3-butanediol, triethylene glycol, 1 : 2-cyclohexanediol, pentaerythritol, benzotrimethylol.  (2) Substituted alcohols: monohydric aliphatic, e.g. ethylene chlorhydrin, ethanolamine, 2-nitrobutanol, glycol monoesters, glycol monoethers, glycol monoformals; monohydric aromatic, e.g. p-methoxy benzyl alcohol, chlorobenzyl alcohols, nitrobenzyl alcohols, 2-anilino-ethanol; polyhydric, e.g. 2-chloro-1 : 3-propanediol, 2-nitro-1 : 3-propanediol, diethanolamine.  Other compounds are esters of hydroxy acids and carbonyl substituted alcohols.  A list of the acids which may be used to prepare the glycol monoesters is given.  The preferred monohydroxy compounds are the highly branched chain aliphatic alcohols containing from 8 to 20 carbon atoms, prepared by the "Oxo" synthesis.  A detailed description of the preparation of these alcohols is given.  In examples the complex formals of the general formula are prepared.  Compounds are prepared: (1) from C13 "Oxo" alcohols (A and B) and tripropylene glycol, x=3; (2) as in (1) but x=2; (3) from n-butyl carbitol and polypropylene glycol 150, x=2; (4) as in (1) and (2) but having the average molecular formula where x=2.3; (5) from C13 "Oxo" alcohol and triethylene glycol, x=2; (6) from C13 "Oxo" alcohol and pentanediol-1 : 5, x=3.  The complex formals may be used as the lubricant base for grease compositions or blended with mineral oils or other synthetic lubricants (see Group III).  They are also useful as plasticizers, solubilizers, insecticides, weed killers, rust preventives, solvents, dewaxing aids, detergents and as raw materials for household detergents or fumigants.ALSO:Synthetic lubricating compositions comprise complex formals of general formula <FORM:0732086/III/1> wherein A and B are C2 to C60 organic groups, x and n are integers not less than 2 and y is an integer, the total number of carbon atoms in the molecule being from 20 to 130 (see Group IV (b)).  They may be blended with mineral oil or other synthetic lubricants, and are compatible and may be blended with lubrication addition agents such as viscosity index improvers, pour point depressers, detergents, rust inhibitors and antioxidants.  They may serve as the lubricant base for grease compositions and may be thickened to stable grease structures with grease-forming soaps such as the lithium soaps of high molecular weight substantially saturated fatty acids, the N-acyl p-aminophenols, silica gels and treated bentonites.  The formulation and preparation of a grease containing 79 per cent complex formal, 20 per cent lithium fatty acid soap (Litholite A) and 1 per cent phenyl alphanaphthylamine is described.