Process for making renewable source-based citrate esters and acylated citrate esters
AssigneeArcher Daniels Midland Company
InventorStephen Howard
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Abstract
Improved processes are described for making trialkyl esters and acylated trialkyl esters of carboxylic acids, as well as epoxidized trialkyl esters and acylated trialkyl carboxylate esters, such as are used in developing plasticized PVC compositions. In particular, processes are described for conducting the esterification and acylation steps involved in making the acylated trialkyl esters in a single vessel without an intermediate purification step, by means of a Lewis acid metal triflate catalyst.
Claims6
A process for making an acylated trialkyl citrate ester or mixture of such esters, comprising a) forming a trialkyl citrate ester or esters by reacting citric acid, citric acid anhydride or citric acid chloride with one or more alcohols to substantial completion in the presence of a catalytically effective amount of a Lewis acid metal triflate catalyst while continually removing azeotropic water under reflux conditions, then b) in the same vessel and with the same Lewis acid metal triflate catalyst performing an acylation of the trialkyl citrate ester or esters by reaction with an acyl donor, and c) recovering at least a portion of the catalyst from the same vessel for reuse, wherein the process is performed without an intermediate step of isolating or purifying the trialkyl citrate ester or esters before the acylation thereof.
Dependencies are inferred from the claim text.