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Preparation method of ethyl methacrylate

A technology of ethyl methacrylate and methacrylic acid, applied in the field of preparation of ethyl methacrylate, can solve the problems of not mentioning the production process of ethyl methacrylate and the like, and achieve the effect of less corrosion

Inactive Publication Date: 2012-11-07
上海和创化学科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] CN10655233C introduces the use of N-oxygen compounds and one or more compounds selected from manganese salt compounds, copper salt compounds, 2,2,6,6-tetramethylpiperidine compounds and nitroso compounds As a polymerization inhibitor, but the patent clearly pointed out that the applicable methacrylates are methyl methacrylate, butyl methacrylate, and hydroxyethyl methacrylate, and did not mention whether it is suitable for the production process of ethyl methacrylate

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] The reactor is a 1000ml four-necked flask, and the rectification tower is Φ20×1.5 with a height of 600mm, and a Φ3 θ ring stainless steel filler is installed inside.

[0022] The catalyst is sodium bisulfate, and the polymerization inhibitor is 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxynitride free radical.

[0023] Add methacrylic acid, absolute ethanol, polymerization inhibitor 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxynitride free radical and catalyst sodium bisulfate into the reactor, wherein methacrylic acid 258g, 414g of absolute ethanol, 8g of sodium bisulfate, 0.18g of 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxynitride free radical, the azeotropic reaction of water and excess ethanol The product enters the azeotropic rectification tower, and the discharge at the top of the tower is the azeotrope of water and ethanol. After reacting for 8 hours, the reaction liquid sample is taken for analysis. The conversion rate of methacrylic acid is 92.0%, and the hea...

Embodiment 2

[0025] The reactor is a 1000ml four-necked flask, and the rectification tower is Φ20×1.5 with a height of 600mm, and a Φ3 θ ring stainless steel filler is installed inside.

[0026] The catalyst is sodium bisulfate, and the polymerization inhibitor is hydroquinone.

[0027] Add methacrylic acid, dehydrated alcohol, polymerization inhibitor and catalyst to reactor, wherein methacrylic acid is 258g, dehydrated alcohol 414g, catalyst 8g, hydroquinone 0.18g, the azeotrope of water and excess ethanol generated After entering the azeotropic rectification tower, the output from the top of the tower is an azeotrope of water and ethanol. After 8 hours of reaction, the reaction liquid sample is taken for analysis. The conversion rate of methacrylic acid is 92.5%, and the heavy component content in the reaction liquid is 0.06%.

Embodiment 3

[0029] The reactor is a 1000ml four-neck flask, the rectification tower is Φ20×1.5, the height is 600mm, and there is a Φ3

[0030] Theta ring stainless steel packing.

[0031] The catalyst is sodium bisulfate, and the polymerization inhibitor is 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxynitride free radical and hydroquinone.

[0032] Methacrylic acid, dehydrated alcohol, polymerization inhibitor and catalyst are added reactor, wherein methacrylic acid is 258g, dehydrated alcohol 414g, catalyst 8g, polymerization inhibitor 2,2,6,6-tetramethyl-4- Hydroxypiperidine-1-oxynitride free radical 0.09g, hydroquinone 0.09g, the azeotrope of generated water and excess ethanol enters the azeotropic rectification tower, and the output from the tower is the azeotrope of water and ethanol After 8 hours of reaction, the reaction liquid sample was taken for analysis, the conversion rate of methacrylic acid was 92.6%, and the heavy component content in the reaction liquid was 0.025%.

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PUM

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Abstract

The invention provides a preparation method of ethyl methacrylate, which takes methacrylic acid and absolute ethanol as raw materials to react under the effects of a catalyst and a polymerization inhibitor so as to generate the ethyl methacrylate and water, wherein the use amount mol ratio of the methacrylic acid to the absolute ethanol is within (1: 1)-(5: 1); the mass use amount of the catalyst accounts for 0.3-0.5% of the mass sum of the methacrylic acid and the ethanol in a reaction kettle; the mass use amount of the polymerization inhibitor accounts for 0.005-0.2% of the mass sum of the methacrylic acid and the ethanol in the reaction kettle; the reaction temperature is controlled to 85-100 DEG C; and a tower top temperature is controlled to 76-78 DEG C. The preparation method adopts an esterification process and a water-carrying agent does not need to be additionally added; the catalyzing effect of the selected catalyst is good and the reaction time is 6-8 hours and is greatly shortened compared with that of an esterification reaction; the conversion per pass of the methacrylic acid is more than 90% and the un-reacted methacrylic acid can be recycled; and the catalyst and the polymerization inhibitor also can be recycled, so that the production cost of the ethyl methacrylate is greatly reduced.

Description

technical field [0001] The invention relates to a preparation method of chemical products, in particular to a preparation method of ethyl methacrylate. Background technique [0002] Ethyl methacrylate is widely used in coating resins, ink resins, adhesives, PMMA sheets, pesticides, paper, leather and textile finishing agents and other industries. [0003] The preparation method of ethyl methacrylate generally adopts transesterification method and esterification method. The transesterification method generally uses organotin catalysts, titanium catalysts, etc. These catalysts generally have low catalytic activity at low temperatures. Because the boiling point of ethanol is low, the reaction temperature of transesterification cannot be high. If the temperature is high, ethanol will be prematurely It is taken away from the top of the tower, so the transesterification reaction is adopted, and the reaction time is as long as more than 30 hours. The catalyst of the esterificatio...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C69/54C07C67/08
CPCY02P20/584
Inventor 安丰发
Owner 上海和创化学科技有限公司