Bis(aryloxyalkyl) esters of aromatic polycarboxylic acids and method of preparation
The invention provides a compound of the formula: wherein Ar is selected from the group consisting of aryl, monosubstituted aryl and polysubstituted aryl, heteroaryl, monosubstituted heteroaryl and polysubstituted heteroaryl; Ar′ is selected from the group consisting of aryl, monosubstituted aryl and polysubstituted aryl, heteroaryl, monosubstituted heteroaryl and polysubstituted heteroaryl; R is an alkylene radical having 2-20 carbon atoms; and n=1-20. The compounds of the invention are used with polymer resins to enhance their gas barrier properties.
1. A method for making a compound of the formula:
wherein Ar is selected from the group consisting of aryl, monosubstituted aryl and polysubstituted aryl, heteroaryl, monosubstituted heteroaryl and polysubstituted heteroaryl; Ar′ is selected from the group consisting of aryl, monosubstituted aryl and polysubstituted aryl, heteroaryl, monosubstituted heteroaryl and polysubstituted heteroaryl; R is an alkylene radical having 2-20 carbon atoms; and n=1-20; which method comprises:
reacting in a esterification reactor having a heated packed partial condenser a compound of the formula
with a compound of the formula
wherein Ar, Ar′, R and n are as defined above, at a temperature range of about 150° C. to about 275° C. in the presence 0.1 wt. % of hypophosphorous acid as of a color stabilizer for a sufficient time until the diester is formed and wherein the temperature of the packed partial condenser is maintained above the boiling point of water and below the boiling of the alcohol or glycol ether reaction component thus allowing continuous reflux of the alcohol or glycol ether component while simultaneously removing the water of esterification and wherein said method provides a product mixture containing 99.4% diester and 0.6% monoester.
2. The method of claim 1 , wherein the temperature of the partial condenser is maintained in the range of about 115° C. to about 135° C.