Powdery 1,4-cyclohexanedicarboxylic acid
AssigneeNew Japan Chemical Co., Ltd.
InventorsShinya Inoue, Yoshihiro Ishibashi, Kango Fujitani
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Abstract
An object of the present invention is to provide a powder of high-purity 1,4-cyclohexanedicarboxylic acid with excellent powder flowability. The invention provides a powder of high-purity 1,4-cyclohexanedicarboxylic acid having particle size distributions (volume basis) such that D10 is within a range of 5 to 55 μm, D50 is within a range of 40 to 200 μm, and D90 is within a range of 170 to 800 μm; and having an aerated bulk density of 0.4 to 0.8 g/cm3, a packed bulk density of 0.5 to 1.0 g/cm3, and a compressibility of 10 to 23%.
Claims7
Powdery 1,4-cyclohexanedicarboxylic acid having:
- particle size distributions (volume basis) such that D10 is within a range of 5 to 55 μm, D50 is within a range of 40 to 200 μm, and D90 is within a range of 170 to 800 μm;
- an aerated bulk density of 0.4 to 0.8 g/cm3;
- a packed bulk density of 0.5 to 1.0 g/cm3;
- and
- a compressibility of 10 to 23%.
Powdery 1,4-cyclohexanedicarboxylic acid produced by a method comprising the steps of:
- (1) subjecting dialkyl (C1-C4) terephthalate to nuclear hydrogenation to obtain dialkyl (C1-C4) 1,4-cyclohexanedicarboxylate;
- (2) hydrolyzing the dialkyl (C1-C4) 1,4-cyclohexanedicarboxylate obtained in step (1) in the presence of an acid catalyst in the presence of water or a water-containing solvent to obtain 1,4-cyclohexanedicarboxylic acid;
- (3) crystallizing the 1,4-cyclohexanedicarboxylic acid obtained in step (2);
- (4) subjecting crystals of the 1,4-cyclohexanedicarboxylic acid obtained in step (3) to solid-liquid separation;
- and
- (5) drying, drying and granulating, or drying and crushing wet crystals of the 1,4-cyclohexanedicarboxylic acid obtained in step (4), wherein the step of drying the wet crystals in step (5) is a step of drying the wet crystals while stirring;
- and optionally
- (6) classifying a powder of the 1,4-cyclohexanedicarboxylic acid obtained in step (5).
Dependencies are inferred from the claim text.