Synthesis method of tert-butyl (meth) acrylate

Abstract

The invention discloses a synthesis method of tert-butyl (meth) acrylate. Belongs to the technical field of fine chemical engineering. The method comprises the following steps: (methyl) acrylic acid and isobutene react in a first reactor in the presence of a polymerization inhibitor and a catalyst, and a mixture from the first reactor enters a stripping section; a mixture of (methyl) acrylic acid and a polymerization inhibitor enters a rectifying section; (methyl) acrylic acid flowing down from the rectifying section reacts with isobutene evaporated from the stripping section in the reaction section, the reacted mixture is discharged from the bottom of the reaction rectifying tower, and unreacted isobutene is discharged from the top of the reaction rectifying tower; and separating the reacted mixture discharged from the bottom of the reactive distillation tower to obtain the tert-butyl (meth) acrylate. The synthesis method provided by the invention has the characteristics of high conversion rate and good selectivity, and can prolong the operation cycle of the esterification catalyst.

Description

technical field [0001] The invention relates to a method for synthesizing tert-butyl (meth)acrylate, which belongs to the technical field of fine chemicals. Background technique [0002] Tert-butyl acrylate (tBA) and tert-butylmethacrylate (tBMA) are important organic acid esters, which are colorless and transparent liquids at room temperature. Since tBA / tBMA has a highly reactive unsaturated double bond and a tert-butyl ester (-COOR) structure that is easily hydrolyzed into a carboxylic acid, it can be self-polymerized or copolymerized with other vinyl monomers to prepare a variety of copolymers and homopolymers. things. Its copolymer has excellent physical and chemical properties such as light resistance, water resistance, and oil resistance. The finished product has the advantages of strong adhesion, good transparency, and clear film formation. be more and more widely used. [0003] The traditional preparation methods of acrylate include: vinyl chloride potassium cyani...

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Problems solved by technology

[0005] Chinese patent CN101155771A discloses a method for synthesizing tert-butyl (meth)acrylate. Solid acids such as sulfuric acid or solid phosphoric acid are used as catalysts, and tert-butanol is decomposed into isobutylene, which is dissolved in an organic solvent containing acrylic acid and reacted to obtain the product. The disadvantage is that the process is complicated, and the catalyst and by-product water are difficult to treat.

[0006] Chinese patent CN103073426A discloses a method for producing tert-butyl acrylate with an acidic cation exchange resin as a catalyst. A kettle reaction is adopted. In a reaction kettle equipped with acrylic acid, cationic resin and polymerization inhibitor, liquid isobutylene is added dropwise for 1.5 to 4 hours. The reaction is carried out at -20-40°C, and the product is obtained by keeping it warm for 6-8 hours. The disadvantage is that it is a batch reaction process, and the reaction time is long and the efficiency is too low.

The process adds a relatively high content of olefin polymerization inhibitor tert-butanol, which increases the complexity of the recovery process; no polymerization inhibitor system is mentioned, and the process is more cumbersome; the highest conversion rate is 83.76% in terms of isobutylene

[0008] Chinese patent CN 104276948 A discloses a process for preparing tert-butyl (meth)acrylate, which uses a strong acidic ion exchange resin catalyst and is packed in a tubular reactor connected in series with multiple fixed-bed reactors. , 1.0~5.0MPa, volume space velocity 0.5~5.0h-1, acid-ene molar ratio 1.0~5.0:1, isobutene reacts with acrylic acid to form ester, the conversion rate is up to 78% based on isobutene, selectivity not mentioned

There are common problems such as low esterification yield, complicated process, polymerization risk, and high energy consumption.

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