Amoco Corporation

Michael R Green

Wayne P Schammel

Chang M Park

Adel B Abdul-Malek

A method for reducing the formation of dust produced by solid aromatic anhydrides, and aromatic anhydride compositions that have a reduced tendency to emit aromatic anhydride dust, are disclosed. The method comprises treating the aromatic anhydride with low levels of suitable organic compounds.

Suppression of dust from solid aromatic anhydrides

A process for the oxidation of pseudocumene to TMLA is disclosed which comprises catalytic oxidation of pseudocumene with air in the presence of acetic acid in an oxidation zone in the liquid phase wherein the weight ratio of acetic acid to pseudocumene is in the range of about 0.5-0:1.0 and the catalyst comprises one or more heavy metal oxidation catalysts comprising zirconium, cobalt, and manganese to provide about 0.1 to about 0.4 weight percent total metals based on pseudocumene and a source of bromine. The addition of the bromine component is controlled to provide a total of about 0.10 to about 0.30 weight percent total bromine based on pseudocumene. The total weight ratio of bromine ions to total metals ions is about 0.5 to about 2.0. The zirconium content is about 1 to about 5% and the manganese content is about 14 to about 60% each by weight of the total metals. The reaction temperature is about 300.degree. F. to about 420.degree. F. The crude trimellitic anhydride is hydrolyzed with water or a mixture of a low molecular weight carboxylic acid and water. Alternatively, a trimellitic anhydride/dimethylformamide adduct is prepared and this adduct is hydrolyzed with a mixture of a low molecular weight carboxylic acid and water. Trimellitic acid is useful in the manufacture of polyesters and polyamide-imides.

Process for the production and recovery of trimellitic acid

There is provided a trimellitic anhydride composition having a reduced tendency to form trimellitic anhydride dust which composition comprises trimellitic anhydride treated with at least one organic compound wherein the organic compound is both liquid and substantially non-volatile at normal ambient temperatures and pressures. There is also provided a method for suppressing dust emitted from trimellitic anhydride which method comprises treating the trimellitic anhydride with the aforementioned organic compounds.

Suppression of trimellitic anhydride dust

A process for the manufacture of polycarboxylic acids is disclosed. In this novel process, antimony is used to improve the selectivity of cobalt-manganese-bromine or zirconium-cobalt-manganese-bromine oxidation system. Polymethylbenzenes such as pseudocumene are converted to their corresponding polycarboxylic acids which are used to manufacture plasticizers and polyamide-imide polymers used as molding compounds for replacement of metals.

Oxidation of polyalkylaromatics

An improved process for the manufacture of trimellitic acid from pseudocumene feedstock is disclosed. In this process, lead (IV) is used as a catalyst component in addition to the cobalt, manganese, and zirconium catalyst. The use of lead (IV) reduces higher boiling impurities and improves the yield. In our novel process, pseudocumene is converted to trimellitic acid which is used to manufacture plasticizers and polyamide-imide polymers used as molding compounds for replacement of metals.

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Geneva, IL, United States of America

Michael R Green