Method for producing propylene glycol methyl ether acetate

Abstract

The invention relates to a method for producing propylene glycol methyl ether acetate. The method is characterized in that a reactive kettle made of an acid-resisting material is applied to a reactive fractionating tower and the front passage of a material kettle on the lower part of the reactive fractionating tower; under the existence of a catalyst, when the number of moles of propylene glycol methyl ether is excessive compared with that of the acetic acid, the esterification is carried out concentratively in the reactive kettle; the obtained product and the unreacted material are evaporated and pass an acid catcher so that the acidic catalyst with a high boiling point is collected in liquid phase; the material of gas phase enters the reactive fractionating tower through a material inlet; an entrainer is added at the upper part of the reactive fractionating towel so as to remove the water in the material by azeotropy; under the action of the layered solid acid catalyst, the residual acetic acid in the material continues to react at the reaction section of the lower part of the material inlet of the reactive fractionating towel so that the material finally dropped in the material kettle of the reactive fractionating towel has no acidic compositions, thus avoiding the corrosion on the equipment in the subsequent separating and refining process; and the obtained product has low acidity and completely meets the requirement of the product standard.

Description

(1) Technical field [0001] The present invention relates to a kind of method of producing propylene glycol methyl ether acetate. It belongs to the technical field of organic chemical product manufacturing. (2) Background technology [0002] Propylene glycol methyl ether acetate (commonly known as propylene glycol methyl ether acetate) has both an ether bond and a carbonyl ester structure in its molecule. It has a solubility parameter similar to that of a variety of organic polymer materials. All have strong dissolving power, and their dissolving power to some resins is even better than glycol ethers such as propylene glycol methyl ether, ethylene glycol ethyl ether, and ethylene glycol butyl ether. Although its relative molecular weight is larger than that of ordinary solvents, it has good miscibility with water, and its moderate boiling point and slow volatilization make it an important solvent. It can be used as a solvent for ethyl cellulose, nitrocellulose, cellulose ac...

AI Technical Summary

Problems solved by technology

[0012] The purpose of the present invention is to overcome some shortcomings in the existing production technology of propylene glycol methyl ether acetate, provide a kind of crude product that does not contain acetic acid substantially, make the service life of the equipment when recycling raw materials and refined products in the back track longer, and the investment is relatively low Low, can produce the method for the production of propylene glycol methyl ether acetate of the lower qualified product of acidity again

Images