A kind of m-aminobenzoic acid spherical crystal and preparation method thereof

A technology of aminobenzoic acid and spherical crystals, which is applied in the preparation of cyanide reaction, chemical instruments and methods, and the preparation of organic compounds, etc. It can solve the problems of poor chemical stability, high production cost, and easy agglomeration of products, and achieve fluidity Improvement, non-perishability, chemical stability improvement effect

Active Publication Date: 2022-07-12
TIANJIN UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The cooling crystallization process of m-aminobenzoic acid in this method is carried out in a water-p-chlorotoluene system. Experiments are carried out according to the disclosed method of the invention. The prepared m-aminobenzoic acid crystals are needle-shaped and are crystal form I, with a particle size of about 20 μm. , small particle size acicular crystal habit will lead to easy agglomeration of the product, poor chemical stability, small particle size acicular metastable crystal form I has hidden dangers of crystal transformation due to the aforementioned reasons, and the crystallization process needs to add alkali to adjust pH, complex operation, and requires equipment Corrosion resistance, high production cost

Method used

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  • A kind of m-aminobenzoic acid spherical crystal and preparation method thereof
  • A kind of m-aminobenzoic acid spherical crystal and preparation method thereof
  • A kind of m-aminobenzoic acid spherical crystal and preparation method thereof

Examples

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Effect test

Embodiment 1

[0064] At 60°C and 250r / min stirring speed, 10g m-aminobenzoic acid crystal form I raw material was dissolved in 100g isopropanol to prepare m-aminobenzoic acid solution, the solution concentration was 0.091g / g solution, at 3°C / 10min Cool the solution down to 10°C at a cooling rate, continue stirring at 250 r / min until crystals emerge, and continue stirring at constant temperature for 40 minutes to make the crystals coalesce into balls. At this time, the density of the crystal slurry is 0.078 g / g of the solution, and then the crystal slurry is filtered, washed with water, Blast drying at 50°C for 12h, the spherical crystals of m-aminobenzoic acid can be obtained. The purity of the spherical crystals of m-aminobenzoic acid obtained by testing is 98.1%, and the volume average particle size is 1.22mm. figure 2 As shown in the figure, the angle of repose is 25.8°, the fluidity of the product is greatly improved, and the post-processing such as filtration, washing, drying, packagi...

Embodiment 2

[0066] Under the stirring speed of 65°C and 300r / min, 13g of m-aminobenzoic acid crystal form I was dissolved in 100g of ethylene glycol to prepare m-aminobenzoic acid solution, the solution concentration was 0.115g / g solution, at 5°C / 10min The solution was cooled to 5°C at a cooling rate of 100 rpm, stirring was continued for 300 r / min until crystals emerged, and the crystals were agglomerated into balls by stirring at a constant temperature for 60 min. At this time, the density of the crystal slurry was 0.080 g / g of the solution, and then the crystal slurry was filtered and washed with water. , 50 ℃ blast drying for 12h, the spherical crystals of m-aminobenzoic acid can be obtained. The purity of the obtained m-aminobenzoic acid spherical crystals is 98.0%, the volume average particle size is 0.63mm, the angle of repose is 24.4°, and the fluidity of the product is greatly improved. The agglomeration rate of spherical crystals is 6.0%, which is far less than 58-64% of needle-...

Embodiment 3

[0068] Under the stirring speed of 50 ° C and 200 r / min, 11 g of m-aminobenzoic acid crystal form I was dissolved in 100 g of ethanol to prepare a m-aminobenzoic acid solution with a concentration of 0.099 g / g solution. The solution was cooled to 10 °C at a rate of 200 r / min until the crystals appeared, and the constant temperature stirring was continued for 50 minutes to make the crystals coalesce into balls. ℃ blast drying for 10h, the spherical crystals of m-aminobenzoic acid can be obtained. The purity of the obtained m-aminobenzoic acid spherical crystals is 98.2%, the volume average particle size is 0.55mm, the angle of repose is 27.7°, and the fluidity of the product is greatly improved. The agglomeration rate of spherical crystals is 6.5%, which is far less than 58-64% of needle-like crystals; the tap density of spherical crystals is 0.35g / cm 3 , which improves the storage and transportation efficiency of m-aminobenzoic acid products; the specific surface area of ​​sp...

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Abstract

The invention relates to a spherical crystal of m-aminobenzoic acid and a preparation method thereof. Under stirring at 45~65 ℃, the raw material of m-aminobenzoic acid crystal form I was dissolved in an organic solvent to prepare a m-aminobenzoic acid solution, the solution was cooled to 5~20 ℃, and the stirring was continued until the crystals appeared, and the stirring was continued for 30 minutes. ~60min, the crystals are coalesced into balls, then the solid liquid crystal slurry is separated, and the wet solid product is filtered, washed and dried to obtain m-aminobenzoic acid spherical crystals. The spherical crystal prepared by the invention can effectively improve the chemical stability and crystal stability of the crystal form I of m-aminobenzoic acid. The purity of spherical crystals is more than 98%, the volume average particle size is 0.55-1.50mm, the crystal particles are round, the fluidity is high, the angle of repose is 24.3-27.7°, the agglomeration rate is 3.0-6.5%, and the tap density is 0.28-0.35g / cm3, the specific surface area is 0.14 ~ 0.23m2 / g.

Description

technical field [0001] The invention belongs to the technical field of chemical engineering industrial crystallization, in particular to a spherical crystal of m-aminobenzoic acid and a preparation method thereof. Background technique [0002] Meta-aminobenzoic acid (CAS: 99-05-8), alias 3-aminobenzoic acid, English name is 3-Aminobenzoicacid, molecular formula C 7 H 7 NO 2 , the molecular weight is 137.1360, and the structural formula is as follows: [0003] [0004] Meta-aminobenzoic acid is usually white or pale yellow needle-like crystals with a melting point of 173-174°C. Slightly soluble in water, easily soluble in methanol, ethanol, acetone, ether and other solvents. Meta-aminobenzoic acid is an important fine organic chemical product and organic intermediate. It is widely used in the synthesis of new organic light-emitting materials, azo dyes, new plant growth regulators, and in the preparation of new pharmaceutical intermediates. With the continuous developm...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C227/42C07C229/60
CPCC07C227/42C07C229/60
Inventor 鲍颖肖一婷周丽娜拓振光高宇锋侯宝红滕汝刚
Owner TIANJIN UNIV
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