초록 ▼

A composite material for controlling oxygen flux into a thermal cell comprises a bottom sheet formed to have a pocket. The bottom sheet is impermeable to oxygen. A plurality of particles is placed in the pocket. The plurality of particles reacts exothermally when exposed to oxygen. A top sheet is se

A composite material for controlling oxygen flux into a thermal cell comprises a bottom sheet formed to have a pocket. The bottom sheet is impermeable to oxygen. A plurality of particles is placed in the pocket. The plurality of particles reacts exothermally when exposed to oxygen. A top sheet is sealed to the bottom sheet at a flange around the pocket to enclose the plurality of particles such that the particles cannot fall out of the pocket. The top sheet has a substrate which is highly permeable to oxygen. The substrate is coated with an oxygen permeable silicone based elastomer to a thickness which regulates an oxygen flux into the pocket when the top sheet is exposed to oxygen. The composite material further comprises an oxygen impermeable barrier film bonded to the top sheet by pressure sensitive adhesive for preventing exposure of the top sheet to oxygen until the body warmer is intended to be used. A method for making a top sheet material involves coating a silicone rubber layer onto a smooth surface, partially curing the silicone, pressing a porous substrate against the silicone rubber layer, and completely curing the silicone rubber such that it adheres to the substrate.

대표청구항 ▼

[ What is claimed is:] [1.] A composite material for controlling oxygen flux into a thermal cell comprising:a) a bottom sheet formed to have a pocket, said bottom sheet being impermeable to oxygen;b) a plurality of particles placed in said pocket, said plurality of particles reacting exothermally wh

[ What is claimed is:] [1.] A composite material for controlling oxygen flux into a thermal cell comprising:a) a bottom sheet formed to have a pocket, said bottom sheet being impermeable to oxygen;b) a plurality of particles placed in said pocket, said plurality of particles reacting exothermally when exposed to oxygen; andc) a top sheet sealed to said bottom sheet at a flange around said pocket to enclose said plurality of particles such that said particles cannot fall out of said pocket, said top sheet having a substrate which is highly permeable to oxygen, said substrate being coated with an oxygen permeable silicone based elastomer to a thickness which regulates an oxygen flux into said pocket when said top sheet is exposed to oxygen, wherein said oxygen flux into said pocket is about 1.5.times.10.sup.5 cm.sup.3 /100 in..sup.2 /day to about 3.5.times.10.sup.5 cm.sup.3 / 100 in..sup.2 /day.