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AssigneeLucite International UK Limited
InventorsDavid William Johnson, Graham Ronald Eastham, Martyn Poliakoff, Thomas Andrew Huddle
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A process for the production of methacrylic acid is described. The process comprises the base catalysed decarboxylation of at least one or a mixture of dicarboxylic acids selected from itaconic, citraconic or mesaconic acid. The decarboxylation is carried out in the range greater than 240 and up to 275° C. to provide high selectivity. The methacrylic acid product may be esterified to produce an ester. A method of preparing polymers or copolymers of methacrylic acid or methacrylic acid esters using the process is also described. Optionally, the process may be preceded with a decarboxylation and, if necessary, a dehydration step on a source of pre-acid such as citric acid or isocitric acid.
A continuous process for the production of methacrylic acid by the base catalysed decarboxylation of at least one dicarboxylic acid selected from itaconic, citraconic or mesaconic acid or mixtures thereof, followed by separation of the methacrylic acid product, wherein the decarboxylation is carried out at greater than 240 and up to 275° C. and at pressures which will maintain the reactants in the liquid phase.
A continuous process for the production of methacrylic acid by the base catalysed decarboxylation of at least one dicarboxylic acid selected from itaconic, citraconic or mesaconic acid or mixtures thereof followed by separation of the methacrylic acid product, wherein the decarboxylation is carried out in the temperature range between 240 and 290° C. and the dicarboxylic acid(s) reactant(s) are exposed to the reaction conditions for a time period of at least 80 seconds and at pressures which will maintain the reactants in the liquid phase.
Dependencies are inferred from the claim text.