Preparation method for extracting and refining crystals by dimethylolbutyric acid

Abstract

The invention relates to the technical field of chemical purification of dimethylolbutyric acid, in particular to a method for preparing refined crystals by extracting dimethylolbutyric acid, which comprises the following steps: 1) adding reacted mixed concentrated solution containing dimethylolbutyric acid into rotary evaporation equipment, and carrying out reduced pressure distillation on the mixed concentrated solution; 2) adding methanol into rotary evaporation equipment, and carrying out reduced pressure distillation to obtain a faint yellow viscous kettle liquid; 3) adding the faint yellow viscous kettle liquid into a centrifugal reactor, and adding an ester solvent, so that the mixed solution is in a transparent state; 4) cooling the mixed solution to obtain a mixed solution containing dimethylolbutyric acid crystals; 5) performing centrifugal treatment on the mixed solution by controlling a centrifugal reactor to obtain a wet dimethylolbutyric acid finished product, and 6) adding the wet dimethylolbutyric acid finished product into a double-cone dryer for drying treatment to obtain the dimethylolbutyric acid finished product.

Description

technical field [0001] The invention relates to the technical field of chemical purification of dimethylol butyric acid, in particular to a preparation method for extracting refined crystals of dimethylol butyric acid. Background technique [0002] 2,2-Dihydroxymethylbutyric acid (DMBA) is a chemical substance with the molecular formula C 6 h 12 o 4 , is a white or slightly yellow crystalline solid with two main hydroxyl groups, a tertiary hydroxyl group and an aliphatic side group in its molecule, and 2,2-dimethylolbutyric acid is in many solvents It has good solubility in all, and because the molecule contains a hydrophobic terminal ethyl group, it can improve the flexibility and water resistance of the product. [0003] When the factory prepares, add the calculated formaldehyde and butyraldehyde in the reaction kettle at one time, after cooling down to 12°C, add the prepared catalyst solution dropwise, and react at a constant temperature of 13-18°C for 14 hours, so as ...

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Problems solved by technology

[0003] When the factory prepares, add the calculated formaldehyde and butyraldehyde in the reaction kettle at one time, after cooling down to 12°C, add the prepared catalyst solution dropwise, and react at a constant temperature of 13-18°C for 14 hours, so as to prepare dimethylol When purifying dimethylol butyric acid, dichloroethane and methanol are commonly used as solvents to extract dimethylol butyric acid, but the dimethylol butyric acid extracted by this method The crystal folding effect and controllability are poor, and dichloroethane is highly toxic. Using dichloroethane will cause hidden dangers to workers and increase the tedious operation of the process; and methanol is used as a solvent, and its crystal folding is difficult High, and there are disadvantages of easy caking