Patent GB-687348-A (GB)
Title: Improvements in or relating to the manufacture of complex esters
Inventor: MORTON RONALD WILLIAM
IPC: C07C69/34
Filed: 1949-03-24
Abstract: Complex esters having the general formula R1-OOC-R2-COO-R3-OOC-R4-COO -R5, in which R1 and R5 are aliphatic alcohol or ether alcohol residues, R2 and R4 are the hydrocarbon radicals of aliphatic dicarboxylic acids or are direct carbon-to-carbon linkages and R3 is the hydrocarbon or oxygenated hydrocarbon radical of a glycol or polyglycol, all the radicals R1 to R5 being saturated, are prepared by the reaction in one or more stages in the presence of an alkali metal or ammonium bisulphate as esterification catalyst, of appropriate aliphatic alcohols, glycols or polyglycols and dicarboxylic acids in proportions to give said complex ester. Suitable reactants are C4 to C24 polyglycols, or mixtures thereof, C1 to C12 alkanols or mixtures thereof, and C6 to C20 dicarboxylic acids or mixtures thereof, though acids down to oxalic may be used. Esterification may be effected in several ways.  Thus, all the ingredients may be reacted together in one stage; the glycol may be reacted with the acid to form a glycol half-ester which is then esterified with the alcohol; the alcohol may be reacted with the acid to form a half-ester which is then esterified with the glycol; the glycol may be reacted in alkyl interchange with the alcohol diester of the acid.  The esterifications may be broken down into any number of stages; thus, half the glycol can be esterified with all the acid, half the alcohol is added in a second stage, the remainder of the glycol in a third and the remainder of the alcohol in a fourth stage. The proportions of the reagents may be varied; they may be such as will yield a pure complex ester or a blend of the complex ester with the diester of the alcohol and acid.  The products may be used as lubricants (see Group III).  In examples: (1) a complex ester is formed from 2-ethyl hexanol, adipic acid and polyglycol 200 (mainly tetraethylene glycol) by the one-stage method; (2) a complex ester is formed from 2-ethyl hexanol, sebacic acid and polyglycol 200 by the glycol half-ester method; (3) blends of complex ester and alcohol diester are formed from sebacic acid, polyglycol 200 and nonyl alcohol, 2-ethylhexanol and C9 Oxo-alcohol respectively by the one-stage and glycol half-ester methods; in all cases, sodium bisulphate is the catalyst.  In some of the examples the rate of reaction is compared with the lower rate obtained where p-toluene sulphonic acid is used as catalyst.  Iso-octanol, capryl alcohol and triethylene glycol are further examples of specified reactants. Specifications 666,697, 680,438, 683,803, 687,346, [Group III], and 687,347 are referred to.ALSO:Complex esters suitable as lubricants having the general formula R1-OOC-R2-COO-R3-OOC-R4-COO-R5 in which R1 and R5 are aliphatic alcohol or ether alcohol residues, R2 and R4 are hydrocarbon radicals of aliphatic dicarboxylic acids or are direct carbon-to-carbon linkages and R3 is the hydrocarbon or oxygenated hydrocarbon radical of a glycol or polyglycol, all of the radicals R1 to R5 being saturated, are prepared by the reaction in one or more stages in the presence of an alkali metal or ammonium bisulphate as esterification catalyst, of appropriate alcohols, acids and glycols in proportions to give the required complex ester (see Group IV (b)). The reactants may be used in proportions yielding the pure complex ester or a blend of the complex ester and the diester of the alcohol and dicarboxylic acid.  Suitable reactants are C4 to C24 polyglycols or mixtures thereof, C1 to C12 alkanols or mixtures thereof and C6 to C20 dicarboxylic acids or mixtures thereof though acids down to oxalic may be used.  Complex esters particularly suitable as lubricants contain 20-100 and preferably 30 to 60 carbon atoms.  In examples: (1) a complex ester is prepared from 2-ethyl hexanol, adipic acid and polyglycol 200 (mainly tetraethylene glycol); (2) a complex ester is formed from 2-ethyl hexanol, sebacic acid and polyglycol 200; (3) blends of complex ester and alcohol diester are formed from sebacic acid, polyglycol 200 and nonyl alcohol, 2-ethylhexanol and C9 oxoalcohol respectively.  Other reactants mentioned are iso-octanol, capryl alcohol and triethylene glycol. Specifications 666,697, 680,438, 683,803, 687,346 and 687,347 are referred to.