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Comprehensive utilization method for byproduct of p-hydroxybenzene hydantoin production

A technology of p-hydroxyphenylhydantoin and p-hydroxybenzene, which is applied in the field of polymer chemical industry to achieve the effect of reducing production costs

Inactive Publication Date: 2010-06-09
TIANJIN VOCATIONAL INST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The purpose of the invention is to solve the problem of comprehensive utilization of the by-products produced by p-hydroxybenzene hydantoin

Method used

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  • Comprehensive utilization method for byproduct of p-hydroxybenzene hydantoin production

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0012] Add 48g (0.8mol) of urea, 40g (0.42mol) of phenol, 200mL of water and 100mL of 30% hydrochloric acid in sequence in a 500mL four-necked bottle equipped with an electric stirring device, a thermometer, and a constant pressure feeder, and start stirring. When the temperature reaches 75-80° C., 74.0 g (0.4 mol) of 40% glyoxylic acid solution is started to be added dropwise, and the dropwise addition is completed in 8-10 hours, and then the heat preservation reaction is continued for 10 hours. Then it was cooled to 35° C., and the precipitate was filtered. After drying, the weight was 44.4 g, and the yield was 60.3%. Concentrate the mother liquor in vacuo to dryness to obtain 52.5 g of solids, including 28.5 g of p-hydroxyphenylglycolic acid and urea dimer, and about 24.0 g of unreacted urea, which are set aside.

Embodiment 2

[0014] In a 500ml four-neck flask equipped with an agitator and a thermometer, add 48.6g (0.60mol) of 37% formaldehyde solution, add 52.5g of the solid matter obtained in Example 1 in batches under stirring, and control the reaction temperature with an electric heating mantle at 70- 75°C, 30% sodium hydroxide solution was added dropwise during the reaction to control the pH of the solution to 6.5-8, and 57.7 g of modified urea-formaldehyde resin was obtained after 3 hours of reaction.

Embodiment 3

[0016] In the 500ml four-necked bottle that stirrer, thermometer are housed, add 37% formaldehyde solution 100g, add the solid matter 52.5g (0.4mol) that embodiment 1 obtains in batches under stirring, then add industrial urea 34g in batches, use An electric heating mantle controls the temperature to 70-75° C. During the reaction, 30% sodium hydroxide solution is added dropwise to control the pH of the solution to 6.5-8. After 3 hours of reaction, 98.7 g of modified urea-formaldehyde resin is obtained.

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Abstract

The invention relates to a comprehensive utilization method for producing by products with hydroxyphenyl hydantoin, in particular to a method for synthezing modified urea formaldehyde resin by using the by products of reaction among glyoxalic acid, phenol and carbamide and unconverted carbamide to replace phenol and carbamide. The invention firstly proposes a method to ensure that hydroxyphenyl glycollic acid, carbamade dimmer, and unconverted carbamide are effectively separated from the product, and then the by product is partially or totally used for replacing carbamide and formaldehyde to condense and prepare modified urea formaldehyde resin. Preferably, 30 to 50 percent of the by product is adopted to replace the raw material, namely, carbamide, to control the accuracy of the chargingand the metering of carbamide during the synthesis process. Modified urea formaldehyde resin can be widely applied to coating, adhesive, plastics, etc., the production cost of hydroxyphenyl hydantoincan be reduced and the contamination problem of production waste liquor can be eliminated through the comprehensive utilization of modified urea formaldehyde resin.

Description

technical field [0001] The invention relates to a method for comprehensive utilization of by-products produced by p-hydroxybenzenehydantoin, especially a method for synthesizing modified urea-formaldehyde resins by replacing phenol and urea with glyoxylic acid, phenol and urea condensation reaction by-products and unconverted urea, which belongs to macromolecule chemical industry. Background technique [0002] P-hydroxybenzodiazepine is an important raw material for the preparation of amoxicillin and amoxicillin cephalosporin. There are a lot of documents about the preparation of p-hydroxyphenylhydantoin at home and abroad, and the US patent US4230869 (1980-10-28) and the inventor have carried out a detailed introduction in "Fine and Specialty Chemicals" 2004, 12 (1): 8-9 . Generally, it is obtained by the condensation reaction of glyoxylic acid, phenol and urea under strong acidic conditions. In actual production, the yield of p-hydroxyphenylhydantoin is about 45%-61%. Th...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08G12/36
Inventor 李建生朱虹陆亮张永锋
Owner TIANJIN VOCATIONAL INST