Abstract:
PROBLEM TO BE SOLVED: To provide a method for efficiently producing a benzene tetracarboxylic acid from a raw material containing two or more tricyclic aromatic hydrocarbons each having a specific structure.SOLUTION: The benzene tetracarboxylic acid is efficiently produced by selectively hydrogenating the raw material, which contains two or more hydrocarbons selected from the group consisting of tricyclic aromatic hydrocarbons having an anthracene skeleton and tricyclic aromatic hydrocarbons having a phenanthrene skeleton, into a 1,2,3,4,5,6,7,8-octahydro form using, as a hydrogenation catalyst, a catalyst containing two or more active metals selected from the group consisting of nickel, molybdenum, cobalt and tungsten, and then oxidizing the 1,2,3,4,5,6,7,8-octahydro form with a metal oxide.
Abstract:
PROBLEM TO BE SOLVED: To provide a method for producing a high-purity aromatic polycarboxylic acid polychloride indispensable as an intermediate of a medicine or an agrochemical, or especially for the production of a functional polymer such as an aromatic polyimide or an aromatic polyester. SOLUTION: The method for producing the high-purity aromatic polycarboxylic acid polychloride includes reacting an aromatic polycarboxylic acid with trichloromethylbenzene compound by using a chloride or oxide of iron or zinc as a catalyst, and distilling and purifying the product. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a method for manufacturing high-quality, high-purity pyromellitic acid and high-purity pyromellitic anhydride which are colorless and almost free from byproducts. SOLUTION: High-purity pyromellitic acid is manufactured by dissolving crude pyromellitic acid or crude pyromellitic anhydride in water by heating, treating the resulting solution with activated carbon and subsequently cooling the solution to precipitate crystals followed by filtration. Further, the obtained high-purity pyromellitic acid is converted to its anhydride by heating at 170-260 deg.C to manufacture high-purity pyromellitic anhydride.
Abstract:
PROBLEM TO BE SOLVED: To provide a method capable of manufacturing trimellitic acid or pyromellitic acid in high yield while producing a byproduct in a little amount when they are manufactured by oxidizing a polyalkyl substituted aromatic aldehyde or its oxidation derivative. SOLUTION: When a two-staged liquid phase oxidation is carried out with molecular oxygen in the presence of bromine or a catalyst consisting of bromine and a heavy metal at 180-280 deg.C in an aqueous solvent, the first stage is carried out in a continuous process and the second stage is carried out in a continuous or batch process, and the bromine is dividedly added to the first stage and the second stage.