Patent GB-666697-A (GB)
IPC: C07C69/34
Abstract: 666,697. Complex esters. STANDARD OIL DEVELOPMENT CO. Aug. 18, 1946 [Sept. 1, 1948; Sept. 20, 1948], Nos. 23005/48 and 24573/48. Class 2 (iii). [Also in Group III] A complex ester suitable for use as a lubricant and having the general formula R<SP>1</SP>OOC-R<SP>11</SP>COO-R-OOC-R<SP>11</SP>-COOR<SP>1</SP> is obtained by reacting together under esterification conditions and in one or more stages two molar proportions of a dicarboxylic acid (R<SP>11</SP>#<SP>COOH)</SP> COOH) , two molar proportions of an aliphatic monohydric alcohol (R<SP>1</SP>OH) and one molar proportion of a polyglycol (R#<SP>OH)</SP> OH) , wherein the acid is a branched chain C 8  or C 9  saturated monohydric aliphatic alcohol or a mixture in which such alcohols predominate and the polyglycol is a polyethylene glycol up to and including hexaethylene glycol or a polyethylene glycol fraction whose average molecular weight does not substantially exceed that of hexaethylene glycol. The esters may be prepared by reacting equimolar amounts of the monohydric alcohol and acid to form the alcohol half ester and then reacting the latter with the glycol, or by refluxing all the components together in the presence of an esterification catalyst and water entrainer but it is preferred to esterify one molar proportion of the glycol with two molar proportions of the dicarboxylic acid to form the glycol half ester and then esterify the latter with two molar proportions of the monohydric alcohol. The esterification is preferably effected under reflux at 150- 200‹ C., using an esterification catalyst such as sulphuric acid or an aryl sulphonic acid and a water entrainer such as an aromatic hydrocarbon and any residual reactants should be removed by vacuum stripping the product. In examples: sebacic acid is first esterified with triethylene glycol and the half ester formed then esterified with 2-ethyl-hexanol, p-toluene sulphonic acid being used as catalyst and xylene as a water entrainer in each stage. The properties of this ester as a lubricant are given and compared with those of specified lubricating oils. The lubricating properties of esters derived from capryl alcohol, adipic acid and triethylene glycol; sebacic acid, triethylene glycol and a commercial mixture of C 9 - C 8  branched chain alcohols (a C 9 (Oxo) alcohol or a mixture of capryl alcohol and 2-ethyl hexanol) are also given and compared with the properties of di-2-ethyl-hexyl sebacate. The lubricating properties of the esters obtained by the one-stage method from 2-ethyl hexanol, sebacic acid and the following glycols: 1,5- pentane diol; triethylene glycol; tetraethylene glycol and of the esters obtained from the same reactants by the monohydric alcohol half ester method as well as the ester obtained by the latter method from 2-ethyl hexanol, sebacic acid and nonaethylene (or ethylene) glycol, are compared. A table is also given to show the properties of the esters obtained by the glycol half-ester method from sebacic acid and 2- ethyl hexanol with tetra- (hexa- and nona-) ethylene glycols and a further table compares the properties of esters obtained in the one stage process from sebacic acid and triethylene glycol with 2-ethyl-hexanol; 2-ethyl butanol, 2-methyl pentanol and 2-methyl 1-propanol, respectively, whilst the properties of the ester obtained from sebacic acid, tetraethylene glycol and n-octyl alcohol are also given. The properties of the esters when obtained from the same reactants by the various specified methods of esterification are also compared, the following components of these esters being among those specified: 2-ethyl-hexanol, sebacic (or adipic) acid and polyglycol 200. U.S.A. Specifications 2,075,107 and 2,295,165 are referred to. The first Provisional Specification defines the esters as being derived from an aliphatic dicarboxylic acid or acids containing up to 12 carbon atoms in the molecule, a monohydric alcohol or mixtures of such alcohols, and a polyglycol or polyglycols.