Abstract

In a method for preparing a cathode of a secondary battery, a method for preparing a purified N-methyl pyrrolidinone (NMP), and a method for purifying a waste NMP, an inhibitor is added to prevent NMP from being decomposed to produce formaldehyde during the process. 1. The inhibitor may be a phenol-based antioxidant and/or an amine-based light stabilizer.

IPC Classes  ?

• H01M 4/62 - Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
• B01D 3/34 - Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping with one or more auxiliary substances
• C07D 207/267 - 2-Pyrrolidones with only hydrogen atoms or radicals containing only hydrogen and carbon atoms directly attached to other ring carbon atoms with only hydrogen atoms or radicals containing only hydrogen and carbon atoms directly attached to the ring nitrogen atom
• H01M 4/02 - Electrodes composed of, or comprising, active material
• H01M 4/04 - Processes of manufacture in general
• H01M 4/139 - Processes of manufacture

Abstract

In a method for purifying highly pure isopropyl alcohol used in a semiconductor cleaning process, diacetone alcohol present in isopropyl alcohol is removed by an adsorption process, and diacetone alcohol, triisopropyl borate, and metal impurities are removed by a distillation process. The purified isopropyl alcohol may have a purity of has the moisture of 10 ppm or less, the triisopropyl boron compound of 50 ppt or less, and each metal of the metal impurities of 20 ppt or less.

IPC Classes  ?

• C12H 1/16 - Pasteurisation, sterilisation, preservation, purification, clarification, or ageing of alcoholic beverages without precipitation by physical means, e.g. irradiation
• C12H 1/04 - Pasteurisation, sterilisation, preservation, purification, clarification, or ageing of alcoholic beverages combined with removal of precipitate or added materials, e.g. adsorption material with the aid of ion-exchange material or inert clarification material, e.g. adsorption material

Abstract

Provided is a method for purifying waste N-methyl-2-pyrrolidone, the method comprising the steps of: reacting the waste N-methyl-2-pyrrolidone containing an amine compound with an acid anhydride; converting the amine compound into an amide compound; and removing the amide compound by distillation, thereby manufacturing high-purity N-methyl-2-pyrrolidone that can be reused.

IPC Classes  ?

• C07B 63/04 - Use of additives
• C07D 201/16 - Separation or purification
• C07D 207/267 - 2-Pyrrolidones with only hydrogen atoms or radicals containing only hydrogen and carbon atoms directly attached to other ring carbon atoms with only hydrogen atoms or radicals containing only hydrogen and carbon atoms directly attached to the ring nitrogen atom

Abstract

Provided is a method for purifying waste N-methyl-2-pyrrolidone, the method comprising the steps of: reacting the waste N-methyl-2-pyrrolidone containing an amine compound with an acid anhydride; converting the amine compound into an amide compound; and removing the amide compound by distillation, thereby manufacturing high-purity N-methyl-2-pyrrolidone that can be reused.

IPC Classes  ?

• C07D 207/267 - 2-Pyrrolidones with only hydrogen atoms or radicals containing only hydrogen and carbon atoms directly attached to other ring carbon atoms with only hydrogen atoms or radicals containing only hydrogen and carbon atoms directly attached to the ring nitrogen atom
• C07D 307/83 - Oxygen atoms
• C07D 307/60 - Two oxygen atoms, e.g. succinic anhydride

Abstract

Provided is a method for purifying an alkylene glycol monoalkyl ether carboxylic acid ester (AGAECE) for photoresist processing, wherein the method comprises the step of distillation after passing industrial AGAECE through a porous adsorbent impregnated with a basic material, and it is possible to obtain a semiconductor-grade high-purity AGAECE maintaining a low acid value and high purity according to the present invention.

IPC Classes  ?

• C07C 67/56 - SeparationPurificationStabilisationUse of additives by solid-liquid treatmentSeparationPurificationStabilisationUse of additives by chemisorption
• C07C 67/54 - SeparationPurificationStabilisationUse of additives by change in the physical state, e.g. crystallisation by distillation
• G03F 7/16 - Coating processesApparatus therefor

Abstract

4. N-methylsuccinimide and γ-butyrolactone are simultaneously removed, and high-purity NMP can be recovered by applying a base to the waste NMP mixed solution.

IPC Classes  ?

• C07D 207/26 - 2-Pyrrolidones

Abstract

The present invention relates to a method for purifying a waste N-methyl-2- pyrrolidone (NMP) mixed solution, and more particularly, to a method for purifying a waste NMP mixed solution using NaBH4 (SBH). The waste NMP mixed solution comprises N-methylsuccinimide (NMS) and y-butyrolactone (GBL). The NMS and GBL are simultaneously removed by adding NaBH4(SBH) to the waste NMP mixed solution. The NMS reacts with the SBH to convert to 5-hydroxy-N-methyl-2-pyrrolidone and the GBL reacts with the SBH to convert to 1,4-butanediol. The SBH is added in an amount of 0.05 to 0.10 wt% based onthe total weight of the waste NMP mixed solution. Water is added in an amount of 5 to 20 wt% based on the total weight of the waste NMP mixed solution. The reaction temperature is 100 to 150°C, and the reaction time is 10 to 60 minutes.

IPC Classes  ?

• C07D 207/267 - 2-Pyrrolidones with only hydrogen atoms or radicals containing only hydrogen and carbon atoms directly attached to other ring carbon atoms with only hydrogen atoms or radicals containing only hydrogen and carbon atoms directly attached to the ring nitrogen atom

Abstract

The present invention relates to a method for purifying a waste N-methyl-2-pyrrolidone (hereinafter referred to as NMP) mixture solution and, more specifically, to a method for purifying a waster NMP mixture solution by using a base. According to the present invention, by applying the base to the waste NMP mixture solution, NMS and GBL can be simultaneously removed to collect high-purity NMP.

IPC Classes  ?

• C07D 207/267 - 2-Pyrrolidones with only hydrogen atoms or radicals containing only hydrogen and carbon atoms directly attached to other ring carbon atoms with only hydrogen atoms or radicals containing only hydrogen and carbon atoms directly attached to the ring nitrogen atom