| abstract |
An oxygen scavenger composition consisting essentially of (a) metallic iron, and (b) at least one oxidation promoter selected from the group consisting of sodium silicate hydrates, silicic acid, sodium alum and sodium borate hydrates, and optionally (c) at least one oxidation promoter aid which is a metal halide compound, and/or (d) a water-insoluble or sparingly water-soluble inert filler; a heat-generating composition having an initial rate of oxygen scavenging of at least 5 ml per gram of said composition in the air at 20 DEG C. during a period of one hour after the oxidation reaction was substantially begun, said composition consisting substantially of the metallic iron (a), a sodium silicate hydrate, and/or silicic acid as an oxidation promoter (b), the oxidation promoter aid (c) and optionally the filler (d); a deoxygenating structure comprising the oxygen scavenger composition and a film having an oxygen permeability of at least 0.005 ml/cm2.min.atm. (O2 partial pressure) covering said composition; and a heat-generating structure comprising the heat-generating composition and a film having an oxygen permeability of 0.4 to 10 ml/cm2.min.atm (O2 partial pressure) covering said composition. |