| 摘要 |
PROBLEM TO BE SOLVED: To prevent water spot of a vegetable or the like by dew condensation and to keep freshness by preventing dew condensation by discharging moisture in a vegetable case to the outside when the case is brought into a high humidity state, and by preventing the dissipation of moisture in the vegetable case when the case is brought into a low humidity state.SOLUTION: Regenerated cellulose whose moisture permeation amount changes depending on humidity is held to the cellulose base material 5 to form a moisture-sensitive and moisture-permeable film 4, in which regenerated cellulose is held in a film form on the whole area of opening spaces 5a. Thereby, the amount of moisture permeation from the vegetable case is suppressed when the humidity is low, and the amount of moisture permeation is increased when the humidity is high. Accordingly, the freshness of fruits and vegetables or the like is kept for a long period of time in a high humidity environment without causing dew condensation in a closed case. Further, since the non-crystalline structure changes reversibly according to the humidity change as a characteristic of the regenerated cellulose, the amount of moisture permeation is reduced when the humidity in the vegetable case is lowered, and accordingly, it becomes possible to maintain a higher humidity environment. |
