Abstract: Cellulose nanofibers are produced by means of a method comprising a step (A) of oxidizing a cellulosic starting material in the presence of an N-oxyl compound and a step (B) of forming the oxidized cellulosic starting material into nanofibers by defibrating the oxidized cellulosic starting material, and a step (C) of performing at least one selected from the following steps: a step (C-1) of treating the cellulosic starting material in water having a hydroxide ion concentration of 0.75 to 3.75 mol/L prior to performing the step (A); and a step (C-2) of subjecting the oxidized cellulosic starting material obtained from the step (A) to hydrolysis in an alkaline solution having a pH between 8 and 14 after performing the step (A) and prior to performing the step (B).

Abstract: Cellulose nanofibers are produced by means of a method comprising a step (A) of oxidizing a cellulosic starting material in the presence of an N-oxyl compound and a step (B) of forming the oxidized cellulosic starting material into nanofibers by defibrating the oxidized cellulosic starting material, and a step (C) of performing at least one selected from the following steps: a step (C-1) of treating the cellulosic starting material in water having a hydroxide ion concentration of 0.75 to 3.75 mol/L prior to performing the step (A); and a step (C-2) of subjecting the oxidized cellulosic starting material obtained from the step (A) to hydrolysis in an alkaline solution having a pH between 8 and 14 after performing the step (A) and prior to performing the step (B).

Abstract: A flotation apparatus F includes a tank 1 for receiving a liquid raw material, and introduces air into the tank 1 to generate bubbles for adsorbing print ink in the liquid raw material to the bubbles, thereby floating and separating the print ink. The flotation apparatus F includes a circulating device for circulating the liquid raw material by raising and then lowering the liquid raw material in the tank 1, an air supply tube 4 for supplying air into the tank 1, and an agitating member 5 provided in the tank 1 for taking the air from the air supply tube 4 and agitating the air for forming the air into fine bubbles. The agitating member 5 has a rotary shaft 51 held horizontally and a plurality of members 52 horizontally separately provided around an outer periphery.

Abstract: A flotation apparatus F includes a tank 1 for receiving a liquid raw material, and introduces air into the tank 1 to generate bubbles for adsorbing print ink in the liquid raw material to the bubbles, thereby floating and separating the print ink. The flotation apparatus F includes a circulating device for circulating the liquid raw material by raising and then lowering the liquid raw material in the tank 1, an air supply tube 4 for supplying air into the tank 1, and an agitating member 5 provided in the tank 1 for taking the air from the air supply tube 4 and agitating the air for forming the air into fine bubbles. The agitating member 5 has a rotary shaft 51 held horizontally and a plurality of members 52 horizontally separately provided around an outer periphery.