Pyrotechnic sheet material having an outer protective barrier layer of a passivating material
First Claim
1. A pyrotechnic sheet material comprising:
- a substrate of oxidizing polymeric film;
an oxidizable material which oxidizes continuously on exposure to atmospheric air applied as a layer on at least a portion of at least one surface of said polymeric film, said polymeric film and said oxidizable material being conjointly capable of reacting together exothermically on ignition; and
a protective barrier layer of passivating material overlying said oxidizing material, said passivating material being a passive metal or oxide thereof, said passive metal being selected from the group consisting of titanium, aluminum, silicon, chromium, nickel, tin, indium, zinc, copper and alloys thereof, one surface of said barrier layer being in contact with said oxidizable layer and the other surface being exposed, and said barrier layer being effective to reduce the migration of atmospheric air to said oxidizable material.
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Accused Products
Abstract
The invention provides pyrotechnic sheet material comprising a substrate of oxidizing polymeric film, for example a film of halogenopolymer, having a layer of oxidizable material, for example magnesium on at least part of its surface. The substrate and the oxidizable material are capable of reacting together exothermically on ignition. The oxidizable material is covered with an overlying protective barrier layer of passivating material comprising a passive metal or an oxide of a passive metal. The barrier layer is effective to extend the storage life of the pyrotechnic sheet material by providing a dense non-porous oxide layer which prevents oxidization of the oxidizable material until ignition of the pyrotechnic sheet material occurs.
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Citations
9 Claims
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1. A pyrotechnic sheet material comprising:
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a substrate of oxidizing polymeric film; an oxidizable material which oxidizes continuously on exposure to atmospheric air applied as a layer on at least a portion of at least one surface of said polymeric film, said polymeric film and said oxidizable material being conjointly capable of reacting together exothermically on ignition; and a protective barrier layer of passivating material overlying said oxidizing material, said passivating material being a passive metal or oxide thereof, said passive metal being selected from the group consisting of titanium, aluminum, silicon, chromium, nickel, tin, indium, zinc, copper and alloys thereof, one surface of said barrier layer being in contact with said oxidizable layer and the other surface being exposed, and said barrier layer being effective to reduce the migration of atmospheric air to said oxidizable material. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification