Patent ID: 11905499
Assignee: TOKUYAMA CORPORATION
Field: Organic fine chemistry (Chemistry)
Classification: CPC C | IPC C

Claim 1:
2. A method for manufacturing the high-purity isopropyl alcohol in which a concentration of an acetal compound having 7 to 12 carbon atoms is equal to or less than 100 ppb by mass, and in which when an acceleration test for performing heating at 120° C. for 4 hours is performed under a nitrogen atmosphere, an amount of increase in the concentration of the acetal compound is 30 or less times a value before the heating and the concentration of the acetal compound is maintained to be a value equal to or less than 100 ppb by mass, the method comprising:
a reduced-pressure distillation step of distilling a low-boiling portion by reduced-pressure distillation so as to perform purification until a concentration of an aldehyde compound having 1 to 6 carbon atoms is reduced to be equal to or less than 500 ppb by mass and a concentration of a ketone compound having 3 to 6 carbon atoms is reduced to be equal to or less than 1000 ppb by mass; and
an atmospheric distillation step of removing a bottom liquid by atmospheric distillation so as to perform purification until the concentration of the acetal compound having 7 to 12 carbon atoms is reduced to be equal to or less than 100 ppb by mass,
wherein:
the reduced-pressure distillation step and the atmospheric distillation step are combined to be performed on crude isopropyl alcohol,
the pressure of the reduced-pressure distillation step is equal to or less than 10 kPa, and
the crude isopropyl alcohol is obtained by a direct hydration method of propylene.