Packaging bag and drying agent with moisture absorption indicator function
A packaging bag and a drying agent with a moisture absorption indicator function are provided without using a heavy metal harmful to the human body. The packaging bag includes a first packaging material ( 10 ) and a second packaging material ( 20 ). The first packaging material ( 10 ) is provided on an outermost side thereof with a transparent barrier film ( 12 ) having a barrier property against water vapor. The second packaging material ( 20 ) has a light-reflective or light-absorbing film ( 24 ) and a pattern printed layer ( 23 ) overlaid on a bag interior side thereof, the pattern printed layer ( 23 ) having a printed moisture-absorbing indicator pattern ( 30 ). A desiccant-containing resin film ( 11, 21 ) which becomes transparent due to moisture absorption is overlaid on a bag interior side of at least one of the first packaging material ( 10 ) and the second packaging material ( 20 ). The drying agent with a moisture absorption indicator function includes an indicator film layer ( 70 ) having a barrier film ( 75 ), a pattern printed layer ( 73 ) for a moisture absorption indicator, and a moisture-absorbing film ( 71 ) containing zeolite, the pattern printed layer ( 73 ) and moisture-absorbing film ( 71 ) being laminated in this order on the barrier film ( 75 ). The drying agent further includes a main desiccant layer ( 61 ) and a moisture permeable film ( 64 ) that are overlaid on the moisture-absorbing film ( 71 ).
1. A drying agent with a moisture absorption indicator function, characterized in that the drying agent comprises:
an indicator film layer including a barrier film, a pattern printed layer having a moisture absorption indicator pattern printed thereon, and a moisture-absorbing film becoming transparent due to moisture absorption, the pattern printed layer and moisture-absorbing film being laminated in this order on the barrier film;
a main desiccant layer; and
a moisture permeable film, the main desiccant layer and the moisture permeable film being provided on the moisture-absorbing film of the indicator film layer.
2. The drying agent with a moisture absorption indicator function according to claim 1 , characterized in that a space is formed between the main desiccant layer and the moisture-absorbing film to provide a bag-like portion.
3. The drying agent with a moisture absorption indicator function according to claim 1 , characterized in that the main desiccant layer comprises a transparent desiccant film or a transparent desiccant molded body.
4. The drying agent with a moisture absorption indicator function according to claim 1 , characterized in that:
the main desiccant layer comprises a granular or tabular desiccant or a deliquescent desiccant; and
the moisture permeable film and the moisture-absorbing film are sealed together at peripheries thereof to form a bag-like portion that encloses therewithin the granular or tabular desiccant or the deliquescent desiccant.
5. The drying agent with a moisture absorption indicator function according to claim 1 , characterized in that the moisture-absorbing film comprises a laminate formed of a desiccant-containing resin layer and a thermoplastic resin.
6. The drying agent with a moisture absorption indicator function according to claim 1 , characterized in that the moisture-absorbing film contains at least one desiccant selected from zeolite, silica gel, and alumina.
7. The drying agent with a moisture absorption indicator function according to claim 1 , characterized in that a moisture permeability control film is overlaid on the moisture-absorbing film, the moisture permeability control film controlling the time that elapses before moisture absorptiveness of the moisture-absorbing film reaches saturation.
8. The drying agent with a moisture absorption indicator function according to claim 7 , characterized in that a space is formed between the main desiccant layer and the moisture permeability control film to provide a bag-like portion.
9. The drying agent with a moisture absorption indicator function according to claim 7 , characterized in that:
the main desiccant layer comprises a granular or tabular desiccant or a deliquescent desiccant; and
the moisture permeable film and the moisture permeability control film are sealed together at peripheries thereof to form a bag-like portion that encloses therewithin the granular or tabular desiccant or the deliquescent desiccant.
10. The drying agent with a moisture absorption indicator function according to claim 7 , characterized in that the moisture permeability control film is a transparent film and has a water vapor transmission rate of 0.01 to 5,000 g/m2/day.