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Columnar crystals of 6-hydroxy-Naphthoic acid and process for the production thereof

A technology of columnar crystal and naphthoic acid, which is applied in the field of 6-hydroxy-2-naphthoic acid columnar crystal and its preparation, can solve the problems of poor handling, filling and storage, small apparent specific gravity, low fluidity, etc. Excellent properties, easy filling operation and high fluidity

Inactive Publication Date: 2002-02-13
北山雅也
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The crystals obtained in this way are in the shape of thin scales, with a small apparent specific gravity, a large angle of repose, and low fluidity.
Therefore, there is a problem that the handling properties of the product, especially the handling properties, filling properties, and storage properties are poor.

Method used

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  • Columnar crystals of 6-hydroxy-Naphthoic acid and process for the production thereof
  • Columnar crystals of 6-hydroxy-Naphthoic acid and process for the production thereof
  • Columnar crystals of 6-hydroxy-Naphthoic acid and process for the production thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0049]A 1-liter autoclave was charged with 90 g of 6-hydroxy-2-naphthoic acid and 450 g of water, and the temperature was raised to 150° C. (gauge pressure 0.42 MPa) to obtain a 6-hydroxy-2-naphthoic acid solution. 2.7 g of 3-hydroxy-2,7-naphthoic acid (manufactured by Ueno Pharmaceutical Co., Ltd.) prepared by the Kolber-Schmidt method with a particle size of about 30 μm was added as a crystal nucleus, and cooled at a rate of 0.5°C / min. To 80°C, aging at this temperature for 30 minutes to precipitate crystals. Filtered at the same temperature to obtain 85 g of columnar crystals. The X-ray diffraction results of the columnar crystals obtained are as follows figure 1 As shown, the representative X-ray diffraction angle 2θ is shown in Table 1, the composition is shown in Table 2, the particle size distribution is shown in Table 3, and the values ​​of various physical properties are shown in Table 4.

[0050] The X-ray measurement was performed under the following conditions.

[005...

Embodiment 2

[0063] A 1-liter autoclave was charged with 100 g of crude 6-hydroxy-2-naphthoic acid (manufactured by Ueno Pharmaceutical Co., Ltd.) prepared by the Kolber-Schmidt method, and 650 g of water, and the temperature was raised to 150°C (gauge pressure 0.42 MPa) to obtain a 6-hydroxy-2-naphthoic acid solution. 1 g of 6-hydroxy-2-naphthoic acid columnar crystals with a particle size of about 100 μm prepared in Example 1 were added as crystal nuclei, cooled to 80°C at a rate of 0.5°C / min, and aged at this temperature for 30 minutes. Crystals precipitated. Filter at the same temperature to obtain 90 g of columnar crystals. The X-ray diffraction results of the columnar crystals obtained are as follows figure 2 As shown, the representative X-ray diffraction angle 2θ is shown in Table 1, the composition is shown in Table 2, the particle size distribution is shown in Table 3, and the values ​​of various physical properties are shown in Table 4.

[0064] Among them, the composition of the cr...

Embodiment 3

[0071] Except that 100 g of the scaly crystals obtained in Comparative Example 1 was used as a raw material, 90 g of columnar crystals were obtained in the same manner as in Example 2. The X-ray diffraction measurement results of the obtained columnar crystals are as follows Figure 4 As shown, the representative X-ray diffraction angle 2θ is shown in Table 1, the composition is shown in Table 2, the particle size distribution is shown in Table 3, and the values ​​of various physical properties are shown in Table 4. Comparative example 2

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Abstract

A process for manufacturing columnar crystals of 6-hydroxy-2-naphthoic acid comprising the steps of, dissolving crude 6-hydroxy-2-naphthoic acid product in an aqueous solvent, adding crystalline 3-hydroxy-2,7-naphthoic acid or columnar crystals as seed crystals, and cooling the mixture to precipitate the desired crystals. The present invention further provides columnar crystals of 6-hydroxy-2-naphthoic acid which have X-ray diffraction peaks 2&thetas; in 16.8-17.8 and / or 21.3-22.3.

Description

Technical field [0001] The invention relates to 6-hydroxy-2-naphthoic acid columnar crystals and a preparation method thereof. Background technique [0002] 6-Hydroxy-2-naphthoic acid can be used as various industrial raw materials, especially raw materials for dyes, pigments, resins, etc. This compound is usually obtained by recrystallization of the substance obtained by the Kolbe-Schmitt reaction with water or water / alcohol solvent to obtain the product. The crystals obtained in this way are in the form of thin scales, have a small apparent specific gravity, a large angle of repose, and low fluidity. Therefore, there are problems with poor product handling, especially portability, filling properties, and storage properties. Summary of the invention [0003] The invention provides a method for obtaining 6-hydroxy-2-naphthoic acid with high apparent specific gravity and excellent fluidity. According to the present invention, it is possible to improve the operability of products ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C51/43
CPCC07C51/43C30B7/00C07C65/11
Inventor 上野隆三北山雅也加藤博行大塚良一
Owner 北山雅也
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