Claims
- 1. An article for use in thermal energy generation comprising a container having a plastic housing, a mixture of hydrophilic silica particles and an endothermic or exothermic compound disposed in the plastic housing of said container, and a liquid activating solution disposed in the plastic housing of said container, separated from said mixture by a rupturable device.
- 2. The article of claim 1 wherein said hydrophilic silica particles are precipitated silica particles.
- 3. The article of claim 2 wherein said precipitated silica particles have a surface area of 150 m.sup.2 /gram and an ultimate particle size of about 0.022 microns.
- 4. The article of claim 2 wherein said compound is an endothermic compound selected from the group consisting of ammonium nitrate, urea, and mixtures thereof.
- 5. The article of claim 2 wherein said compound is an exothermic compound selected from the group consisting of calcium oxide and calcium chloride.
- 6. The article of claim 1 wherein said silica particles are present in an amount by weight of the total article of 15 to 30% to form a gel.
- 7. The article of claim 1 wherein said silica particles are present in an amount by weight of the total composition of 25 to 40%, to form a dry powder.
- 8. The article of claim 1 wherein said liquid activating solution is water.
- 9. The article of claim 1 wherein said silica particles have been surface treated with 0.5-5 parts per hundred by weight of a silicone resin or a silane compiling agent to render them hydrophobic.
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of U.S. application Ser. No. 08/228,147, filed Apr. 15, 1994, which issues as U.S. Pat. No. 5,423,996, on Jun. 13, 1995.
US Referenced Citations (22)
Continuations (1)
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Number |
Date |
Country |
Parent |
228147 |
Apr 1994 |
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