Abstract: A process for producing pyromellitic acid which comprises oxidizing 2,4,5-trimethylbenzaldehyde and/or its oxidized derivative in the presence of a catalyst containing iron, manganese and bromine, or additionally containing zirconium or cerium continuously or semi-continuously using aqueous acetic acid solvent and 0.05-2% by weight of bromide ion. The catalyst used in the present invention has high activity, and the catalyst solution has low corrosive because the reaction is performed at low bromide concentration by using a solvent of aqueous acetic acid. So pyromellitic acid is produced industrially advantageously in high yield continuously or semi-continuously which has been a major difficulty up to now.

Abstract: The cyclohexanetricarboxylic monoester of the present invention is represented by the following formula 1: wherein R is as defined in the specification. The cyclohexanetricarboxylic monoester is useful particularly as the curing agent for epoxy-containing compounds. A heat-curable resin composition comprising the cyclohexanetricarboxylic monoester and an epoxy-containing compound exhibits an excellent curability without using a curing accelerator and provides a colorless transparent cured product which is little discolored even under a long-term exposure to high-temperature conditions. Such a heat-curable resin composition is suitable as sealing materials for photoelectric transducers such as blue LED and white LED, shaped articles, coating materials, adhesives, etc.

Abstract: In the production of an alicyclic aldehyde, a starting aromatic aldehyde is converted into an aromatic acetal for protecting the formyl group. The aromatic ring of the aromatic acetal is then hydrogenated to convert the aromatic acetal into an alicyclic acetal, which is then hydrolyzed to cleave the acetal protecting group to obtain the aimed alicyclic aldehyde.

Abstract: A process for producing pyromellitic acid which comprises oxidizing 2,4,5-trimethylbenzealdehyde and/or its oxidized derivative in the presence of a catalyst containing iron, manganese and bromine, or additionally containing zirconium or cerium continuously or semi-continuously using aqueous acetic acid solvent and 0.05-2% by weight of bromide ion. The catalyst used in the present invention has high activity, and the catalyst solution has low corrosive because the reaction is performed at low bromide concentration by using a solvent of aqueous acetic acid. So pyromellitic acid is produced industrially advantageously in high yield continuously or semi-continuously which has been a major difficulty up to now.

Abstract: A process for refined pyromellitic anhydride which comprises dissolving crude pyromellitic acid or crude pyromellitic anhydride in water, then cooling an aqueous solution thus obtained to perform crystallization as pyromellitic acid, then separating a crystal thus obtained from water, then anhydrating the crystal of pyromellitic acid thus separated with heating to produce pyromellitic anhydride, then vaporizing pyromellitic anhydride thus produced, cooling vapor of pyromellitic anhydride thus obtained, and thereby, recovering a refined crystal of pyromellitic anhydride.

Abstract: What is disclosed is a process for producing &egr;-caprolactone which comprises removing impurities by distillation from a reaction mixture obtained by co-oxidation of cyclohexanone and aldehyde, wherein &egr;-caprolactone separated from a purifying column is contacted with oxygen containing gas in the presence of cobalt. High boiling point components are removed to give an acid value of lower than 0.15 mgKOH/g. Thereby, a high quality &egr;-caprolactone providing improved polymer appearance is produced advantageously on an industrial scale without repeated purifying distillations or without using expensive stabilizer or adsorbent for the improvement of color.

Abstract: A process for producing pyromellitic acid which comprises oxidizing 2,4,5-trimethylbenzealdehyde and/or its oxidized derivative in the presence of a catalyst containing iron, manganese and bromine, or additionally containing zirconium or cerium continuously or semi-continuously using aqueous acetic acid solvent and 0.05-2% by weight of bromide ion. The catalyst used in the present invention has high activity, and the catalyst solution has low corrosive because the reaction is performed at low bromide concentration by using a solvent of aqueous acetic acid. So pyromellitic acid is produced industrially advantageously in high yield continuously or semi-continuously which has been a major difficulty up to now.

Abstract: A process for producing a polycarboxylic acid which comprises performing liquid phase oxidation of polyalkyl-substituted aromatic aldehyde and/or oxide derivative of polyalkyl-substituted aromatic aldehyde as raw material for oxidation with molecular oxygen at two stages in water solvent in the presence of a catalyst comprising bromine or both bromine and a heavy metal(s) at a temperature of 180 to 280 ° C., thereby producing trimellitic acid or pyromellitic acid, wherein said liquid phase oxidation is performed in a continuous operation at the first stage and in a continuous operation or in a batch operation at the second stage and a total amount of bromine in said catalyst is divided to add separately at each the first stage and the second stage.

Abstract: A process for refined pyromellitic anhydride which comprises dissolving crude pyromellitic acid or crude pyromellitic anhydride in water, then cooling an aqueous solution thus obtained to perform crystallization as pyromellitic acid, then separating a crystal thus obtained from water, then anhydrating the crystal of pyromellitic acid thus separated with heating to produce pyromellitic anhydride, then vaporizing pyromellitic anhydride thus produced, cooling vapor of pyromellitic anhydride thus obtained, and thereby, recovering a refined crystal of pyromellitic anhydride.

Abstract: A process for producing a polycarboxylic acid which comprises performing liquid phase oxidation of polyalkyl-substituted aromatic aldehyde and/or oxide derivative of polyalkyl-substituted aromatic aldehyde as raw material for oxidation with molecular oxygen at two stages in water solvent in the presence of a catalyst comprising bromine or both bromine and a heavy metal(s) at a temperature of 180 to 280 ° C., thereby producing trimellitic acid or pyromellitic acid, wherein said liquid phase oxidation is performed in a continuous operation at the first stage and in a continuous operation or in a batch operation at the second stage and a total amount of bromine in said catalyst is divided to add separately at each the first stage and the second stage.

Abstract: A process for producing purified .epsilon.-caprolactone from an .epsilon.-caprolactone-containing reaction product produced by the oxidation of cyclohexanone comprising subjecting the .epsilon.-caprolactone-containing reaction product to an alkali-treatment in the presence of an inert gas atmosphere or to a heat treatment in the presence of an inert gas atmosphere or to a combined alkali-treatment and heat treatment, and distilling the treated reaction product.