Process for making solid methylglycine diacetate (MGDA) alkali metal salt (A), said process comprising the steps of (a) providing a 40 to 60% by weight aqueous solution of said salt (A) having a temperature in the range of from 50 to 90° C., (b) crystallizing salt (A), (c) removing said crystalline salt (A) from the mother liquor by filtration, and (d) subjecting the water containing filter cake from step (c) to an extrusion step.

Process for making solid methylglycine diacetate (MGDA) alkali metal salt (A), said process comprising the steps of (a) providing a 40 to 60% by weight aqueous solution of said salt (A) having a temperature in the range of from 50 to 90° C., (b) crystallizing salt (A), (c) removing said crystalline salt (A) from the mother liquor by filtration, and (d) subjecting the water containing filter cake from step (c) to an extrusion step.

Process for making solid methylglycine diacetate (MGDA) alkali metal salt (A), said process comprising the steps of (a) providing a 40 to 60% by weight aqueous solution of said salt (A) having a temperature in the range of from 50 to 90° C., (b) crystallizing salt (A), (c) removing said crystalline salt (A) from the mother liquor by filtration, and (d) subjecting the water containing filter cake from step (c) to an extrusion step.

The present invention relates to a process for the solidification of hexyl 2-[4-(diethylamino)-2-hydroxybenzoyl]benzoate (INCI diethylamino hydroxybenzoyl hexyl benzoate, DHHB), wherein the process comprises a step (a) of applying a shear rate of at least 400 s-1 to liquid hexyl 2-[4-5 (diethylamino)-2-hydroxybenzoyl]benzoate.

The present invention relates to a process for the solidification of hexyl 2-[4-(diethylamino)-2-hydroxybenzoyl]benzoate (INCI diethylamino hydroxybenzoyl hexyl benzoate, DHHB), wherein the process comprises a step (a) of applying a shear rate of at least 400 s-1 to liquid hexyl 2-[4-5 (diethylamino)-2-hydroxybenzoyl]benzoate.

The present invention relates to a process for the solidification of hexyl 2-[4-(diethylamino)-2-hydroxybenzoyl]benzoate (INCI diethylamino hydroxybenzoyl hexyl benzoate, DHHB), wherein the process comprises a step (a) of applying a shear rate of at least 400 s-1 to liquid hexyl 2-[4-5 (diethylamino)-2-hydroxybenzoyl]benzoate.

Disclosed in the present invention are a crystal form of aromatic vinyl derivatives, and a preparation method therefor and the use thereof. Specifically disclosed in the present invention are crystal form A, crystal form B and crystal form C of a compound as shown in formula I. The crystal forms of the present invention have a good stability, are less hygroscopic and are easy to prepare, and have an important value in terms of the optimization and development of drugs.

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Disclosed in the present invention are a crystal form of aromatic vinyl derivatives, and a preparation method therefor and the use thereof. Specifically disclosed in the present invention are crystal form A, crystal form B and crystal form C of a compound as shown in formula I. The crystal forms of the present invention have a good stability, are less hygroscopic and are easy to prepare, and have an important value in terms of the optimization and development of drugs.

##STR00001##

A refining method according to the present invention is a refining method for crystallizing a compound with at least one crystal form, including setting, as a target wavelength and a target temperature, a specific infrared wavelength and a specific temperature at which a specific crystal form precipitates from a solution of the compound dissolved in a solvent, and using an infrared radiation apparatus capable of emitting infrared radiation including the target wavelength to evaporate the solvent and precipitate the specific crystal form while irradiating the solution with infrared radiation including the target wavelength and adjusting a temperature of the solution to the target temperature.

A refining method according to the present invention is a refining method for crystallizing a compound with at least one crystal form, including setting, as a target wavelength and a target concentration, a specific infrared wavelength and a specific concentration at which a specific crystal form precipitates from a solution of the compound dissolved in a solvent, and using an infrared radiation apparatus capable of emitting infrared radiation including the target wavelength to evaporate the solvent and precipitate the specific crystal form while irradiating a solution of the compound dissolved in the solvent at the target concentration with infrared radiation including the target wavelength.