Method for preparing ether, alkyl diol-bis (p-aminobenzoate)

An aminobenzoate, alkyl diol technology, applied in the field of special chemicals and fine chemicals, to ensure the appearance of color, shorten the time, prevent sublimation effect

Inactive Publication Date: 2018-07-27
江苏湘园化工有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] The patent CN101353311A applied by American Air Products Company in China is titled "Preparation Method of P-Aminobenzoic Acid Ester", which is also aimed at the preparation of ether-based diol-bis-(p-aminobenzoic acid) ester from the disclosed content The process adopts the method of transesterification, which is to use auxiliary alcohol such as isobutanol to react with ethyl p-aminobenzoate to generate p-aminobenzoate with a longer carbon chain, and then perform transesterification with ether-based diol Obtain target product, its purpose is in order to reduce the sublimation loss of p-aminobenzoic acid ethyl ester, but what bring is to be equivalent to one more step reaction, also brings the trouble of the separation and recovery of post-processing different alcohols, said in technical background "This technology does not have the yield reduction, long reaction time and operational problems caused by the volatility of aminobenzoic acid alkyl esters" may not be effectively realized in the actual preparation process

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  • Method for preparing ether, alkyl diol-bis (p-aminobenzoate)
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  • Method for preparing ether, alkyl diol-bis (p-aminobenzoate)

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Embodiment

[0027] A method for preparing ether, alkyl glycol-bis-p-aminobenzoate, chemical reaction is carried out as follows:

[0028]

[0029] Wherein, R in -(RO-)n and -ORO- is a linear or branched alkyl group with 2-6 carbon atoms, and n is an integer between 3-30; in the presence of the catalyst Next, using mixed xylene as a solvent, the entire transesterification reaction is completed in two stages, a low temperature stage and a high temperature stage.

[0030] The solvent is mixed xylene, wherein the content of o-xylene is greater than or equal to 10%, and the content of ethylbenzene is less than or equal to 10%. The solvent used is mixed xylene, which has certain requirements on the ratio of each component, mainly to make the boiling point under normal pressure consistent with the controlled reaction temperature.

[0031] The low temperature stage is that the reaction temperature is 140-145°C, the pressure in the reactor is normal pressure, and the reaction time is 2-3 hours; the high ...

Embodiment 1

[0038] Add 500 grams of PTMEG (poly-1,4-butanediol) with a molecular weight of 1000 to a stainless steel reactor with a stirrer, a thermometer, and a distillation column that can withstand a certain pressure, and heat it into a thermal oil jacket heating, and then add 1200 One gram of mixed xylene with a certain proportion is used as a solvent, and finally 167 grams of benzocaine (ethyl p-aminobenzoate) and 3 grams of high-efficiency catalyst (tetraisopropyl titanate) are added. Turn on the stirring and start heating. When the temperature in the kettle reaches 140-145°C, there will be continuous liquid flowing out of the condenser tube connected to the distillation column. Maintain this temperature and use heating to maintain the amount of liquid vaporized. After 2 hours of reaction, Turn off the cork of the condenser and increase the heating power. When the temperature rises to 165-170°C, maintain the temperature and continue the reaction for 1.5 hours. Then fully open the cor...

Embodiment 2

[0040] Add 234 grams of 1,3-propanediol into a stainless steel reactor with a stirrer, a thermometer and a distillation column that can withstand a certain pressure, and heat it into a thermal oil jacket heating, and then add 1800 grams of the above mixed xylene with a certain ratio As a solvent, 1005 grams of benzocaine (ethyl p-aminobenzoate) and 18 grams of catalyst (tetraisopropyl titanate) were added at the end. Turn on the stirring and start heating. When the temperature in the kettle reaches 140-145°C, there will be continuous liquid outflow from the condenser tube connected to the distillation column. Maintain this temperature and use heating to maintain the amount of vaporized liquid. After 3 hours of reaction, Turn off the cork of the condenser and increase the heating power. When the temperature rises to 170-175°C, maintain the temperature and continue the reaction for 2.5 hours. Then fully open the cork of the condenser, continue heating and gradually increase the n...

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Abstract

The invention provides a method for preparing ether, alkyl diol-bis (p-aminobenzoate). The technology for preparing the compound comprises the following steps: ether diol or alkyl diol is used as a raw material of bridge formation, an ester interchange reaction is carried out for the material and an ester of para amino benzoic acid short chain under the effects of a high efficient catalyst, the reaction is carried out at low temperature and high temperature two reaction segments, a solvent employs mixed xylenes which are mixed according to a certain proportion, and a one pot process is used for finally obtaining a light color product with high purity. The content of the target product is analyzed by high performance liquid chromatography and reaches 99% or above, monoester is less than 1%,a volatile matter (100 DEG C / 10 torr) is less than 0.2%, heat loss at 220 DEG C / 5 torr is 0.1% or below, and consumption of short chain ester of para amino benzoic acid approaches to a theoretical amount.

Description

Technical field [0001] The invention belongs to the technical field of special chemicals and fine chemicals, and relates to a method for preparing ether, alkyl glycol-bis-p-aminobenzoate. Ether or alkyl glycol-bis-p-aminobenzoate is a kind of aromatic primary diamine compound, which has important use value in polyurethane adhesives, sealing materials and elastomers. It has good performance as a curing agent and flexibility modifier. Background technique [0002] The molding characteristics of polyurethane and epoxy resin molecules determine the important role of chain extension crosslinking agent and curing agent in its synthesis process and performance design. It not only participates in the formation of molecules, but also contributes to the conformation and crystallization of the soft and hard phase regions of the polymer. Performance and separation tendency have a great influence. In the case of a large amount of raw materials, chain extension crosslinking agents and curing ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C227/18C07C229/60C08G65/333
CPCC07C227/18C08G65/33313C07C229/60
Inventor 周建安宁
Owner 江苏湘园化工有限公司
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