Preparation method of N,N'-methylene bis (N'-3-hydroxymethyl-2, 5-dioxo-4-imidazolyl) urea

A methylene bis, hydroxymethyl technology, applied to N, can solve the problems of deepening product color, product quality decline, long drying cycle, etc., and achieve the effects of reducing production costs, improving quality, and reducing energy consumption

Inactive Publication Date: 2017-02-01
WUHU HUAHAI BIOLOGY ENG
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The preparation method of imidazolidinyl urea in the prior art has the disadvantages of long drying cycle and high energy consumption. The long drying cycle and high temperature cause polycondensation and resinization of the product, thereby deepening the color of the product, deteriorating water solubility, and declining product quality.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] A preparation method of N,N'-methylene bis(N'-3-hydroxymethyl-2,5-dioxo-4-imidazolyl)urea, comprising the following steps:

[0018] (1) Weigh allantoin and formaldehyde in a molar ratio of 1:1, add 0.05% of the total amount of reactant sodium hydroxide as a catalyst, stir and reflux at a temperature of 70°C for 8h, and adjust with a 5% acetic acid solution pH to neutral, distill water under reduced pressure;

[0019] (2) under stirring, the material after dehydration under reduced pressure is added in ethanol, the mass ratio of material and ethanol is 1: 1.5, precipitates crystal, filters, and washes with deionized water 3 times;

[0020] (3) Put the washed solids into the heat pump drying box for dehumidification and drying in turn. The dehumidification and drying steps in the heat pump drying box are: dehumidify for 3 hours at a temperature of 45°C and an air flow rate of 1m / s, and then dry at a temperature of 25°C for 1h ; Then vacuum-dried at 55°C for 1 hour to obt...

Embodiment 2

[0022] A preparation method of N,N'-methylene bis(N'-3-hydroxymethyl-2,5-dioxo-4-imidazolyl)urea, comprising the following steps:

[0023] (1) Weigh allantoin and formaldehyde in a molar ratio of 1:1.1, add 0.08% of the total amount of reactant sodium hydroxide as a catalyst, stir and reflux at a temperature of 72°C for 6h, and adjust with a 10% acetic acid solution pH to neutral, distill water under reduced pressure;

[0024] (2) under stirring, the material after dehydration under reduced pressure is added in ethanol, the mass ratio of material and ethanol is 1: 1.5, precipitates crystal, filters, and washes with deionized water 3 times;

[0025] (3) Put the washed solids into the heat pump drying box for dehumidification and drying in turn. The dehumidification and drying steps in the heat pump drying box are: dehumidify for 2.5 hours at a temperature of 45°C and an air flow rate of 1.5m / s, and then dehumidify at a temperature of 25°C Dry for 2 hours; then vacuum dry at 53...

Embodiment 3

[0027] A preparation method of N,N'-methylene bis(N'-3-hydroxymethyl-2,5-dioxo-4-imidazolyl)urea, comprising the following steps:

[0028] (1) Weigh allantoin and formaldehyde in a molar ratio of 1:1.2, add 0.1% of the total amount of reactant sodium hydroxide as a catalyst, stir and reflux at a temperature of 74°C for 4h, and adjust with an 8% acetic acid solution pH to neutral, distill water under reduced pressure;

[0029] (2) under stirring, the material after dehydration under reduced pressure is added in ethanol, the mass ratio of material and ethanol is 1:1.5, precipitates crystal, filters, and washes with deionized water 3 times;

[0030] (3) Put the washed solids into the heat pump drying box for dehumidification and drying in turn. The dehumidification and drying steps in the heat pump drying box are: dehumidify for 2 hours at a temperature of 45°C and an air flow rate of 2m / s, and then dry at a temperature of 25°C for 3 hours ; Then vacuum-dried at 50°C for 2 hours...

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PUM

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Abstract

The invention discloses a preparation method of N,N'-methylene bis(N'-3-hydroxymethyl-2, 5-dioxo-4-imidazolyl) urea. The method comprises the following steps: weighing allantoin and formaldehyde according to a molar ratio of 1: (1 to 1.2), adding sodium hydroxide as a catalyst, carrying out stirring reflux for 4-8h at the temperature of 70-74 DEG C, using an acetic acid solution to adjust the pH to be neutral, and carrying out reduced pressure distillation to enable water to be steamed out; after reduced pressure dehydration is carried out on the material, adding the material into ethanol while stirring, separating out crystal, filtering, and washing with deionized water; sequentially putting the washed solid into heat pump drying ovens for dehumidification drying and vacuum drying to obtain the product. The preparation method combines heat pump drying and vacuum drying, and the heat pump drying has functions of drying and dehumidifying, so that the energy consumption is less, the time of the vacuum drying is shortened, the drying temperature is low, and the drying time is short; the preparation method has the advantages of improving the quality of the product, reducing energy consumption and lowering production cost.

Description

technical field [0001] The present invention relates to, specifically, a preparation method of N,N'-methylene bis(N'-3-hydroxymethyl-2,5-dioxo-4-imidazolyl)urea. Background technique [0002] N,N'-methylene bis(N'-3-hydroxymethyl-2,5-dioxo-4-imidazolyl) urea, also known as imidazolidinyl urea, is easily soluble in water and deliquescent, in oil Solubility is very low. Imidazolidinyl urea was first successfully trial-produced by Sutton's laboratory in the mid-1960s. It can be used in creams, lotions, and liquid cosmetics. It has inhibitory effects on Gram-positive bacteria, bacteria, yeast, mold, and fungi. Whether it is cationic, anionic or non-ionic surfactant, or protein does not affect its bactericidal activity, it is usually used as a cosmetic preservative, and can be compatible with almost all components in cosmetics. The pH value for cosmetics is 4-9 , the amount added in cosmetics is usually 0.2-0.3%, and the maximum amount does not exceed 0.6%. [0003] The prepar...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D233/88
CPCC07D233/88
Inventor 茆振斌
Owner WUHU HUAHAI BIOLOGY ENG
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