N-Methylpyrrolidone is referred to as NMP, molecular formula: C5H9NO, English: 1-Methyl-2-pyrrolidinone, appearance is colorless to light yellow transparent liquid, with a slight ammonia smell, miscible with water in any proportion, soluble in ether, acetone and esters, halogenated hydrocarbons, aromatic hydrocarbons and other organic solvents, almost completely mixed with all solvents, boiling point 204℃, flash point 91℃, strong hygroscopicity, stable chemical properties, no corrosion to carbon steel and aluminum, slightly corrosive to copper. It has the advantages of low viscosity, good chemical stability and thermal stability, high polarity, low volatility, unlimited miscibility with water and many organic solvents, etc. This product is a micro-toxic product, and the limit concentration allowed in the air is 100PPM.