Abstract: Disclosed is a method for selective carboxylation of naphthoic acid, or other aromatic mono-acids to form primarily 2,3-naphthalene dicarboxylic acid (2,3-NDA) or other aromatic diacids which comprises reacting said aromatic mono-acid in the presence of one or more metal oxide catalysts, alone, or in combination, and in the presence of about 0.2 to 0.8 moles excess of base over aromatic mono-acid, at a temperature of about 380° C. to about 420° C., and, in a second step, disproportionating the product of said selective carboxylation at a temperature above about 420° C. to form a product with a greatly improved yield of 2,6-naphthalene dicarboxylic acid, or other aromatic dicarboxylic acid.

Abstract: Disclosed is a method for selective carboxylation of naphthoic acid, or other aromatic mono-acids to form primarily 2,3-naphthalene dicarboxylic acid (2,3-NDA) or other aromatic diacids which comprises reacting said aromatic mono-acid in the presence of one or more metal oxide catalysts, alone, or in combination, and in the presence of about 0.2 to 0.8 moles excess of base over aromatic mono-acid, at a temperature of about 380° C. to about 420° C., and, in a second step, disproportionating the product of said selective carboxylation at a temperature above about 420° C. to form a product with a greatly improved yield of 2,6-naphthalene dicarboxylic acid, or other aromatic dicarboxylic acid.

Abstract: Disclosed is a method for reducing alkali metals in aromatic dicarboxylic acids produced by disproportionation or rearrangement of an alkali salt of a mono- or dicarboxylic acid to levels acceptable for polymerization which comprises: a) Washing the aromatic dicarboxylic acid with water in a ratio of about 5:1 water to acid at a temperature of about 70-200° C.; b) Introducing the washed aromatic dicarboxylic acid into a reactor characterized by minimal backmixing, such as a pipe reactor, and reacting the washed aromatic dicarboxylic acid in the pipe reactor at about 100-200° C.; c) Directing the aromatic dicarboxylic acid exiting the pipe reactor to a centrifuge to separate the solid aromatic dicarboxylic acid from water containing contaminants; d) Optionally, combining the solid aromatic dicarboxylic acid again with water in a ratio of about 5:1 at a temperature of about 100-200° C. to further reduce levels of alkali metals.

Abstract: A method of manufacturing an alkali metal salt of 2,3,6,7-naphthalenetetracarboxylic acid. Either a sodium salt or a mixture of sodium salt and potassium salt of at least one naphthalenecarboxylic acid selected form the group consisting of naphthoic acids and naphthalenepolycarboxylic acids is heated to an elevated temperature in an inert gas atmosphere in the presence of a Henkel reaction catalyst and halogenated sodium.

Abstract: A process for converting formic acid esters or transesterification products thereof to carboxylic acids comprising contacting a formic acid ester of the formula (HCOO).sub.n --R where R is aliphatic, cycloaliphatic or aralkyl and n is 1 or 2 with a catalytically effective amount of a soluble iridium salt and an iodide promoter at a temperature of from about 100.degree. C. to about 300.degree. C. in the presence of an organic solvent containing at least one carboxylic acid.

Abstract: Disclosed is a process for the preparation of a naphthalene-2,6-dicarboxylic acid dialkali metal salt which comprises heating an alkali metal salt of naphthoic acid and/or a dialkali metal salt of naphthalene-dicarboxylic acid under pressure with carbon dioxide gas in the presence of a catalyst, wherein an aprotic polycyclic aromatic compound having 2 or 3 rings is used as a reaction medium. Naphthalene-2,6-dicarboxylic acid dialkali metal salt can be obtained in high yield and selectivity with a good reproducibility of the reaction.

Abstract: A process for producing an isomerized benzene carboxylic acid salt by treating a mixture of an aromatic material, water, and a water soluble reagent comprising a Group Ia or IIa metal with oxygen under conditions sufficient to convert at least a portion of the aromatic material to a benzene carboxylic acid salt of the metal; isomerizing the benzene carboxylic acid salt by heating without converting the benzene carboxylic acid salt to a benzene carboxylic acid salt of a different Group Ia or IIa metal prior to isomerizing; and recovering the benzene carboxylic acid salt. Another embodiment further comprises converting the isomerized benzene carboxylic acid salt to isomerized benzene carboxylic acid; regenerating the reagent; recovering the isomerized benzene carboxylic acid; and recycling the reagent thusly regenerated to supply a portion of the reagent required for producing the benzene carboxylic acid salt.

Abstract: A method for removing carbonaceous impurity from zinc oxide by contacting a water slurry of contaminated zinc oxide with oxygen in a reactor at reaction conditions sufficient to produce oxide products of the carbon contaminants and passing the reactor effluent through a filter to collect solid zinc oxide while passing the oxides of carbon through the filter. In a preferred embodiment, contaminated zinc oxide separated from the reaction product in the preparation of terephthalic acid from benzoic acid using zinc benzoate catalyst is subjected to treatment for removal of carbonaceous contaminants before being recycled to reaction with molten benzoic acid to produce zinc benzoate catalyst used in the reaction.

Abstract: Mixture of salts of aromatic mono- or polycarboxylic acids are converted to terephthalate salts in presence of selected catalyst or catalyst mixture, e.g., a mixture of potassium, sodium and cesium benzoates, is disproportionated in the presence of zinc and/or a zinc salt or a mixture of zinc and/or cadmium and a zinc and/or cadmium salt. The mixture of compounds which are to be converted to terephthalate salts will contain at least those of two different alkali metals. A formula m+n is equal to at least 4 is given for determining the catalyst, or catalysts, to be employed. In one embodiment, now preferred, a mixture of sodium, potassium, and cesium benzoates is heated at a reaction temperature of the order of 350.degree.-430.degree. C., more preferably 380.degree.-415.degree. C., in presence of a catalytic mixture of zinc and cadmium benzoates to obtain high yields and rates of reaction at temperatures substantially below those needed in the prior art for similar or better yields, etc.