Kyodo Printing Co., Ltd.

Eisuke Chiba

Tatsuya Ogawa

Shinichi Koizumi

Hiroshi Koyama

Saori Takahashi

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 () and a second packaging material (). The first packaging material () is provided on an outermost side thereof with a transparent barrier film () having a barrier property against water vapor. The second packaging material () has a light-reflective or light-absorbing film () and a pattern printed layer () overlaid on a bag interior side thereof, the pattern printed layer () having a printed moisture-absorbing indicator pattern (). A desiccant-containing resin film () which becomes transparent due to moisture absorption is overlaid on a bag interior side of at least one of the first packaging material () and the second packaging material (). The drying agent with a moisture absorption indicator function includes an indicator film layer () having a barrier film (), a pattern printed layer () for a moisture absorption indicator, and a moisture-absorbing film () containing zeolite, the pattern printed layer () and moisture-absorbing film () being laminated in this order on the barrier film (). The drying agent further includes a main desiccant layer () and a moisture permeable film () that are overlaid on the moisture-absorbing film ().

Packaging bag and drying agent with moisture absorption indicator function

A moisture absorbent material (drying material) with an indicator function is provided without the use of cobalt chloride containing a heavy metal, low molecular organic substance and the like; and a humidity indicator permitting a state of humidity to be found in a simple manner is also provided. The moisture absorbent material with an indicator function () includes a resin layer () containing 5 to 80 wt % zeolite which is provided on at least one surface thereof with a printed layer including a character, shape, picture or the like, so that the printed layer may visibly appear due to the resin layer becoming transparent by moisture absorption. The humidity indicator () is formed by laminating a film () made of a zeolite-containing resin composition, a polyolefin film () having patterns () printed thereon that include characters, symbols, lines or the like, which are printed to have a difference in the print density, and an aluminum foil () through an adhesive, so that the patterns () may be made sequentially visible due to the film () made of the zeolite-containing resin composition becoming transparent by moisture absorption.

Growing community of inventors

Tokyo, Japan

Eisuke Chiba