Process for recovering high-purity N-methyl formamide from waste stripping solution

A technology of methylformamide and stripping solution, applied in the separation/purification of carboxylic acid amide, organic chemistry, etc., can solve the problems of limited use, difficulty in recovering high-purity products, low product quality, etc., and achieve negative impact and considerable economic value , The effect of high product yield
CN109970591AActive Publication Date: 2019-07-05XINZHONGTIAN ENVIRONMENTAL PROTECTION
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
XINZHONGTIAN ENVIRONMENTAL PROTECTION
Publication Date
2019-07-05

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Abstract

The invention relates to the technical field of waste stripping solution recovery, and provides a process for recovering high-purity N-methyl formamide from a waste stripping solution. The process includes rectifying the waste stripping solution containing N-methyl formamide and diethylene glycol methyl ether to obtain a NMF crude product having a mass concentration of 80-90%; repeating 1-3 timesof melting and crystallization; performing partial melting, melting, melt liquid collection and cooling for crystallization to obtain high-purity NMF. A technique combining melting and crystallizationwith rectification is adopted so that a problem that high-purity NMF cannot be obtained through recovery is solved, and the process has advantages of simple procedures, low investment, short period,a high yield and a low cost. The obtained high-purity NMF is high in purity which can be electronic chemical purity that is 99.99%, thus overcoming a problem that purity of a product of rectificationonly can reach 90%.
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Description

technical field

[0001] The invention relates to the technical field of recovery of waste stripping liquid, in particular to a process for recovering high-purity N-methylformamide from waste stripping liquid. Background technique

[0002] The rapid development of the domestic electronics manufacturing industry has greatly increased the use of electronic chemicals such as strippers. In the production process of electronic components such as liquid crystal display panels and semiconductor integrated circuits, it is necessary to use a stripping solution to remove the photoresist coated on the microcircuit protection area as a mask. The stripping solution used is usually made of organic amine and polar organic A mixture of solvents, a mixture of N-methylformamide (NMF) and diethylene glycol methyl ether (MDG) is one of them. This group of solvents has a good effect after mixing, and the industrial usage has been increasing. However, the price is high, and it is difficult to reco...

Claims

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