PROBLEM TO BE SOLVED: To provide a method for efficiently producing a carboxylic acid compound that has an excellent thickening stabilization effect, industrially.SOLUTION: In the method for producing carboxylic acid amide compound of the present invention, a benzene tetracarboxylic acid dianhydride is reacted with an amine represented by the following formula (1): R-NH(1) (in which, Rrepresents an aliphatic hydrocarbon group having 6 or more carbon atoms) to produce an amic acid, and the obtained amic acid is reacted, in the presence of a condensation agent and a surfactant, with an amine represented by the following formula (3): R-NH(3) (in which, Rrepresents an aliphatic hydrocarbon group having 6 or more carbon atoms) to produce a carboxylic acid amide compound.SELECTED DRAWING: None【課題】優れた増粘安定化効果を有するカルボン酸アミド化合物を工業的に効率よく製造する方法を提供する。【解決手段】本発明のカルボン酸アミド化合物の製造方法は、ベンゼンテトラカルボン酸二無水物に下記式（１） Ｒ1－ＮＨ2 （１）（式中、Ｒ1は炭素数６以上の脂肪族炭化水素基を示す）で表されるアミンを反応させてアミック酸を得、得られたアミック酸に、縮合剤及び界面活性剤の存在下で、下記式（３） Ｒ2－ＮＨ2 （３）（式中、Ｒ2は炭素数６以上の脂肪族炭化水素基を示す）で表されるアミンを反応させて、カルボン酸アミド化合物を得る。【選択図】なし
