- Multifunctional finishing of cotton fabrics with 3,3′,4,4′- benzophenone tetracarboxylic dianhydride: Reaction mechanism
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Aqueous solutions of 3,3′,4,4′-benzophenone tetracarboxylic dianhydride (BPTCD) were successfully employed in treatment of cotton fabrics to bring multiple functions onto the cotton cellulose. The overall reaction mechanism of the chemical finishing process was investigated. Results revealed that the dianhydride groups of BPTCD were hydrolyzed to tetracarboxylic acid groups, and the acid could directly react with hydroxyl groups on cellulose under the catalyst sodium hypophosphite to form ester bonds. Such a mechanism is different from the mostly recognized formation of anhydride from polycarboxylic acid and then esterification between the anhydride with hydroxyl groups. FTIR, DSC and thermogravimetric analyzer (TGA) were employed in the analysis of the reactions, respectively.
- Hou, Aiqin,Sun, Gang
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- METHOD FOR OXIDIZING A 1,1,-BIS-(3,4-DIMETHYLPHENYL)-ALKANE TO 3,3',4,4'-BENZOPHENONE TETRACARBOXYLIC ACID
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In a method for oxidizing 1,1-bis-(3,4-dimethylphenyl)-alkane with nitric acid in a pressure vessel to produce 3,3′,4,4′-benzophenone tetracarboxylic acid with concurrent formation of nitric oxide, passing nitric oxide from the pressure vessel into an absorption vessel and reacting nitric oxide in the absorption vessel with molecular oxygen and water to produce an aqueous nitric acid solution prevents discharge of nitric oxide, avoids the risk of oxygen inhibiting the nitric acid oxidation and reduces nitric acid consumption when the nitric acid from the absorption vessel is used for oxidizing the 1,1-bis-(3,4-dimethylphenyl)-alkane.
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Paragraph 0027
(2021/06/22)
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- Method for preparing 3, 3', 4, 4'-benzophenone tetracarboxylic acid
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In a method for oxidizing 1,1-bis-(3,4-dimethylphenyl)-alkane with nitric acid in a pressure vessel to produce 3,3',4,4'-benzophenone tetracarboxylic acid with concurrent formation of nitric oxide, passing nitric oxide from the pressure vessel into an absorption vessel and reacting nitric oxide in the absorption vessel with molecular oxygen and water to produce an aqueous nitric acid solution prevents discharge of nitric oxide, avoids the risk of oxygen inhibiting the nitric acid oxidation and reduces nitric acid consumption when the nitric acid from the absorption vessel is used for oxidizing the 1,1-bis-(3,4-dimethylphenyl)-alkane.
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Paragraph 0030-0031
(2021/06/22)
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- Development and optimization of producing 3,3′, 4,4′-benzophenonetetracarboxylic dianhydride
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This paper includes a series of experiments conducted in order to develop a laboratory method for producing 3,3′, 4,4′-benzophenonetetracarboxylic dianhydride and selection of the optimum conditions, allowing to obtain the greatest yield. 3,3′, 4,4′-benzophenonetetracarboxylic dianhydride is used for the preparation of polyimides with high thermal stability, chemical resistance as well as high strength and high Young's modulus. Benzophenonetetracarboxylic dianhydride was prepared by multistep route: Friedel-Crafts alkylation of o-xylene to obtain 3,3′, 4,4′-tetramethyl benzophenone followed by liquid phase oxidation to benzophenonetetracarboxylic acid and dehydration.
- Yegorov, Anton Sergeyevich,Wozniak, Alyona Igorevna,Ivanov, Vitaly Sergeyevich,Averina, Elena Aleksandrovna,Zhdanovich, Olga Anatolevna
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p. 3063 - 3070
(2017/01/09)
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- A 3,3 the [...], 4,4 the method for preparing [...] -benzophenone tetracidic dianhydride
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The invention discloses a method for synthesizing 3,3',4,4'-benzophenonetetracarboxylic dianhydride by taking o-xylene and bis(trichloromethyl) carbonate as raw materials. The method comprises the steps of: by taking o-xylene and bis(trichloromethyl) carbonate as the raw materials, performing acylation reaction in catalysis of anhydrous lewis acid, thus obtaining bis(3,4-ditolyl)methanone; fully oxidizing bis(3,4-ditolyl)methanone in a potassium permanganate/hydrochloric acid system, and carrying out filtration, concentration, crystallization and the like to obtain 3,3',4,4'-benzophenonetetracarboxylic acid; performing vacuum high-temperature melting and dehydration to 3,3',4,4'-benzophenonetetracarboxylic acid to obtain the 3,3',4,4'-benzophenonetetracarboxylic dianhydride product. The preparation method has the advantages of being simple in technology, high in yield, fewer in three wastes, capable of recycling anhydrous lewis acid, low in production cost and easy for industrial implementation, and the like.
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- PROCESS FOR PRODUCING AROMATIC POLYCARBOXYLIC ACID
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A process for producing an aromatic polycarboxylic acid in which all alkyl groups are converted into carboxyl groups in a high yield by decreasing a residual amount of an intermediate product is provided. The process comprises oxygen-oxidizing an aromatic compound having a plurality of alkyl groups (e.g., durene) in the presence of a catalyst containing a cyclic imino unit having an N—OR group (wherein R represents a hydrogen atom or a protecting group for a hydroxyl group) and a transition metal co-catalyst (e.g., a cobalt compound, a manganese compound, and a zirconium compound) under heating in a lower-temperature zone and a higher-temperature zone to produce an aromatic polycarboxylic acid in which a plurality of alkyl groups are oxidized into carboxyl groups. In an initial stage of the reaction, the reaction may be conducted in a first lower-temperature zone (a reaction temperature of 60 to 120° C. and a second lower-temperature zone (an intermediate temperature zone) (a reaction temperature of 100 to 140° C.); and then, in a latter stage of the reaction, the reaction may be conducted in a higher-temperature zone (a reaction temperature of 110 to 150° C.).
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Page/Page column 14-15
(2011/04/18)
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- Production method of highly pure pyromellitic dianhydride
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A method of producing pyromellitic dianhydride. The method includes a step of heating a crude pyromellitic acid in the absence of acetic anhydride to convert a part of pyromellitic acid to pyromellitic anhydride, and a subsequent step of heating the resultant mixture in the presence of acetic anhydride to complete the anhydrization of pyromellitic acid. The pyromellitic dianhydride by the method contains little pyromellitic monoanhydride and other monoanhydrides derived from impurities and is less discolored. The pyromellitic dianhydride has particle properties not causing plugging, etc. during its transportation, storage and use.
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Page/Page column 8-10
(2008/06/13)
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- Process for producing benzophenone tetracarboxylic dianhydride
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A process for producing benzophenone tetracarboxylic dianhydride, which comprises adding benzophenone tetracarboxylic acid to a solvent comprising, as the main constituent, an organic compound having a boiling point of more than 100° C. and being inert to benzophenone tetracarboxylic acid and benzophenone tetracarboxylic anhydrides, and heating the resulting mixture. This process enables one to produce benzophenone tetracarboxylic dianhydride having a very low moisture absorbency.
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- Process for, respectively, the production and purification of dicarboxylic and polycarboxylic acid anhydrides
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A method of preparation and/or purification of acid anhydrides is disclosed. Dicarboxylic or polycarboxylic acids contained in the anhydrides to be treated, are dehydrated in an organic solvent in the presence of activated carbon.
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