Method for producing hydraulic medium including difluoroethylene

A method for producing a working medium containing difluoroethylene, comprising mixing a first component containing difluoroethylene at a ratio of more than 65 mol % and held in a first container, and a second component without self-decomposition properties held in a second container, by the following step (A), (B), or (C), the working medium containing difluoroethylene at a ratio of 65 mol % or less based on the entire amount,

• wherein, in step (A),
• the component held in the first container is supplied to the second container under the following condition (A1) or (A2),
• wherein, in condition (A1),
• the temperature (t1) of the component held in the first container at the time of the supply is t1<15° C., the relationship between the gauge pressure (P2) in the second container and the gauge pressure (p1) of the component held in the first container at the time of the supply is p1>P2 at least from the start of the supply to the end of the mixing, and the temperature (T2) in the second container is maintained in a state of T2<15° C., and
• wherein, in condition (A2),
• the component held in the first container at the time of the supply is in a gaseous state in which the temperature (t1) thereof is 15° C.≤t1≤180° C. and the gauge pressure (p1) thereof is p1 [MPaG]<1.22-0.0032t1, the relationship between the gauge pressure (P2) in the second container and the gauge pressure (p1) of the component held in the first container is p1>P2 at least from the start of the supply to the end of the mixing, and the temperature (T2) in the second container is maintained in a state of T2≤180° C. and T2<(1.22−p1)/0.0032,
• wherein, in step (B),
• the component held in the second container is supplied to the first container under the following conditions (B1) and (B2),
• wherein, in condition (B1),
• the temperature (T1) and gauge pressure (P1) in the first container are maintained in a state of T1<15° C. or in a state of 15° C.≤T1≤180° C. and P1 [MPaG]<1.22−0.0032T1 at least from the start of the supply to the end of the mixing, and
• wherein, in condition (B2),
• the gauge pressure (p2) of the component held in the second container is p2>P1 at least at the time of the supply, and
• wherein, in step (C),
• the component held in the first container is supplied to a separately prepared third container under the following condition (C1) or (C2), while maintaining the temperature (T3) and gauge pressure (P3) in the third container in a state of T3<15° C. or in a state of 15° C.≤T3≤180° C. and P3 [MPaG]<1.22−0.0032T3 at least from the start of the following supply to the end of the mixing, and the component held in the second container is supplied so that the gauge pressure (p2) thereof is p2>P3 at least at the time of supply thereof,
• wherein, in condition (C1),
• the temperature (t1) of the component held in the first container at the time of the supply is t1<15° C., the relationship between the gauge pressure (P3) in the third container and the gauge pressure (p1) of the component held in the first container at the time of the supply is p1>P3 at least from the start of the supply to the end of the mixing, and the temperature (T3) in the third container is maintained in a state of T3<15° C., and
• wherein, in condition (C2),
• the component held in the first container at the time of the supply is in a gaseous state in which the temperature (t1) thereof is 15° C.≤t1≤180° C. and the gauge pressure (p1) thereof is p1 [MPaG]<1.22-0.0032t1, the relationship between the gauge pressure (P3) in the third container and the gauge pressure (p1) of the component held in the first container is p1>P3 at least from the start of the supply to the end of the mixing, and the temperature (T3) in the third container is maintained in a state of T3≤180° C. and T3<(1.22−p1)/0.0032.