- METHOD FOR PRODUCING AMIDES OR POLYAMIDES BY USING AROMATIC CARBAMATES BY WAY OF ISOCYANATES AS PRECURSORS THROUGH CATALYZED THERMAL PROCESSES AND METHOD FOR PRODUCING AROMATIC CARBAMATE PRECURSORS FROM AROMATIC AMINES
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The present invention is directed to a process for preparing amides or polyamides by replacing isocyanate starting materials of a catalyzed thermal reaction with aromatic carbamates. Through the catalyzed thermal process involving a non-isocyanate precursor of the present invention, efficiency for producing amides or polyamides can be significantly improved, and the impure side products produced from a side reaction of isocyanate can be greatly curtailed. Hence, amides or polyamides of high purity and yield can be achieved. The invention also relates to a process for preparing aromatic carbamates, the new non-isocyanate precursors for amides or polyamides.
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Paragraph 0072-0073
(2018/07/29)
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- Process for producing aryl carbamates
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PCT No. PCT/JP98/00592 Sec. 371 Date Oct. 13, 1998 Sec. 102(e) Date Oct. 13, 1998 PCT Filed Feb. 13, 1998 PCT Pub. No. WO98/35936 PCT Pub. Date Aug. 20, 1998A process for producing an aryl carbamate of a high purity at a high yield by reacting a diaryl carbonate with an amine compound having one or more hydrogen atoms bonded to the N position in the presence of carboxylic acid(s) of the following general formulae (I): R1-COOH and/or (II): R2-COOH (wherein R1 represents an alkyl or cycloalkyl group having an alpha -positioned carbon atom bonded to only one hydrogen atom, an alkyl group having an alpha -positioned carbon atom bonded to no hydrogen atom, or an aryl or heterocyclic group, and R2 represents an alkyl group having an alpha -positioned carbon atom bonded to two or more hydrogen atoms).
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