Continuous production method for hydroxyethyl methylacrylate

Abstract

The invention discloses a continuous production method for hydroxyethyl methylacrylate. The continuous production method comprises the following steps: allowing methylacrylic acid, a catalyst and a polymerization inhibitor to enter a tubular reactor, introducing ethylene oxide, carrying out a ring-opening reaction at 60 to 80 DEG C and 0.25 to 0.1 MPa so as to prepare a reaction mixed solution, subjecting the reaction mixed solution to condensation and separation so as to obtain excess ethylene oxide and crude hydroxyethyl methylacrylate, allowing the crude hydroxyethyl methylacrylate to enteran intermediate finished product tank, subjecting the crude hydroxyethyl methylacrylate and the polymerization inhibitor to short-path distillation so as to discharge hydroxyethyl methylacrylate anda first residual solution, subjecting the first residual solution to short-path distillation again so as to discharge hydroxyethyl methylacrylate and a second residual solution, subjecting the secondresidual solution to distillation so as to obtain a distillation product, and subjecting the distillation product to cyclic short-path distillation and distillation so as to realize continuous production of hydroxyethyl methylacrylate. The continuous production method provided by the invention has the following advantages: a reaction temperature is low; side reactions are reduced; the loss of rawmaterials is reduced; the conversion rate of the raw materials is improved; and the quality of a product is improved.

Description

technical field [0001] The invention relates to the technical field of organic chemical industry, more specifically to a continuous production method of hydroxyethyl methacrylate. Background technique [0002] Hydroxyethyl methacrylate is an important class of chemical raw materials. Due to its unique structure of carbon chain double bonds, hydroxyl groups and ester groups, it can be used as a polymerization monomer to form a variety of polymers through homopolymerization and copolymerization. It is strong, not easy to peel off, flexible and elastic at room temperature, and has good water resistance, so it is widely used in synthetic acrylic resins, photocurable resins, optical resins, coatings, etc. [0003] At present, there are two main processes for industrial production of hydroxyethyl methacrylate. The first is to add ferric thiocyanate, tetramethylammonium chloride, etc. and a little hydroquinone to methacrylic acid, stir and heat to 90°C , under the protection of ni...

AI Technical Summary

Problems solved by technology

[0003] At present, there are two main processes for industrial production of hydroxyethyl methacrylate. The first is to add ferric thiocyanate, tetramethylammonium chloride, etc. and a little hydroquinone to methacrylic acid, stir and heat to 90°C , under the protection of nitrogen, pass through ethylene oxide gas to react for about 2 hours, cool the reaction product to 60°C, add a small amount of hydroquinone, distill under reduced pressure, collect 86-89°C (0.67kPa) fractions to obtain the finished product, The yield is more than 80%. The disadvantage of this method is that ethylene oxide is flammable and explosive, and has strict requirements on production equipment and operating conditions, as well as a high technical level.

The second kind is that methacrylic acid potassium salt and chlorohydrin react in the presence of a polymerization inhibitor to generate thick methacrylate-2-hydroxyethyl ester, which is salted out and refined to obtain finished products. The synthesis period of this method is long and the product quality is not good. Stable, there are filtration problems of by-products and the disadvantages of high toxicity of chlorohydrin

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