Dibutyl phthalate synthesis process

Abstract

The invention relates to a dibutyl phthalate synthesis process, particularly to a plasticizer synthesis process and provides a dibutyl phthalate synthesis process which is short in time consumption, little in pollution and good in product quality. The process provided by the invention comprises the following steps of: adding phthalic anhydride and n-butyl alcohol with a molar ratio of 1:2 to 1:3 into a 250mL three-neck boiling flask, wherein the three-neck boiling flask is provided with a stirrer, a temperature gauge and a reflux condenser; then, adding 0.3-1.2% of aluminum oxide as a catalyst, heating by using an electric jacket, stirring, and carrying out reflux reaction at 140-240 DEG C for 1-4h; filtering out the catalyst after the reaction is ended, distilling off the n-butyl alcohol, and then, distilling by using steam to remove excessive alcohol; and separating, filtering and carrying out reduced pressure distillation on the crude product after alcohol removal so as to obtain a product, and then measuring the refractive index of the product.

Description

Technical field: [0001] The present invention relates to a kind of synthetic technique of plasticizer, more specifically, relate to the synthetic technique of dibutyl phthalate. Background technique: [0002] Phthalate plasticizers are currently the main plasticizers that are most widely used and have the largest output. They have the advantages of light color, low toxicity, good electrical properties, low volatility, and low odor. They are widely used in plastics. Its total consumption accounts for more than 80% of the total consumption of plasticizers. [0003] Dibutyl phthalate (DBP) is a colorless, non-toxic, transparent liquid with an aromatic smell. It has good solubility for various resins and is one of the most widely used plasticizers. Its output accounts for my country's growth More than 20% of the total amount of plasticizer, its structural formula is shown in the figure below. [0004] [0005] Dibutyl phthalate [0006] DBP is mainly used in the processing ...

AI Technical Summary

Problems solved by technology

[0006] DBP is mainly used in the processing of polyvinyl chloride to make the product have good flexibility. Its traditional synthesis method is to use H 2 SO 4 As a catalyst, it is synthesized with phthalic anhydride and n-butanol. This method is cheap, high in activity, low in reaction temperature, mature in process, and high in product yield. However, it also has a series of side reactions caused by oxidative dehydration of alcohol by concentrated sulfuric acid. , serious corrosion, and the three wastes pollution and product quality are difficult to control and other shortcomings

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