US5423996A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Compositions for thermal energy storage or thermal energy generation
Assignee: University of Dayton
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Filing: 1994-04-15
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Granted: 1995-06-13
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Expires: 2014-04-15
Abstract
Abstract A composition for thermal energy storage or thermal energy generation comprising a silica based gel or dry powder in the form of silica particles containing a water/urea phase change material for thermal energy storage or an endothermic or exothermic compound for thermal energy generation. The water/urea phase change material stores and releases at least 50 cal/gm of thermal energy in freezing and melting, and has a melting and a freezing point in the range of -11 DEG C. to -15 DEG C. The endothermic compound is preferably ammonium nitrate, urea, or combinations thereof. The exothermic compound is preferably calcium oxide or calcium chloride. The thermal energy storage composition may find use in a variety of applications including medical wraps, food servingware, and "blue ice" for cold packs or food storage. The thermal energy generation composition may find use as medical wraps, food servingware, and refrigerators when endothermic and medical wraps, food servingware, heaters, stadium seats, boots, vests, caps ear muffs, and scarves when exothermic.
Inventors
- 👤 Ival O. Salyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:01
CPC Classifications
A; A61; A61F; A61F7/00; A61F7/02; A61F7/03; A61L; A61L15/00; A61L15/16; A61L15/18; C; C09; C09K; C09K5/00; C09K5/02; C09K5/06; C09K5/063; A61F2007/0203; A61F2007/0215; A61F2007/0219; A61F2007/0268; A61F2007/0276; A61F2007/0292; A61F7/10; A61F7/106; F; F28; F28D; F28D20/00; F28D20/02; Y; Y02; Y02E; Y02E60/00; Y02E60/14
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
106 words
A composition for thermal energy storage comprising a water/urea phase change material contained in a particulate silica matrix, said water/urea phase change material being 80% -54.5% by weight water and 20% -45.5% by weight urea, said phase change material having a thermal energy storage of greater than 50 cal/gm and a melting and a freezing point in the range of -11° C. to -15° C., and said particulate silica matrix being present in said composition in an amount of from 30 to 40% by weight while said water/urea phase change material is present in said composition in an amount of from 70 to 60% by weight.
Claim 2
Dependent Claim
106 words
A composition for thermal energy storage comprising a water/urea phase change material contained in a particulate silica matrix, said water/urea phase change material being 80% -54.5% by weight water and 20% -45.5% by weight urea, said phase change material having a thermal energy storage of greater than 50 cal/gm and a melting and a freezing point in the range of -11° C. to -15° C., and said particulate silica matrix being present in said composition in an amount of from 30 to 40% by weight while said water/urea phase change material is present in said composition in an amount of from 70 to 60% by weight.
Claim 3
Dependent Claim
30 words
The composition of claim 1 wherein said particulate silica matrix is a hydrophobic silica which has been surface treated with 1-15 parts per hundred by weight of a silicone resin.
Claim 4
Dependent Claim
25 words
The composition of claim 1 wherein said water/urea phase change material comprises less than 75% by weight water and at least 25% by weight urea.
Claim 5
Dependent Claim
21 words
The composition of claim 1 wherein said water/urea phase change material has a thermal energy storage of greater than 60 cal/gm.
Claim 6
Dependent Claim
118 words
An article for use in thermal energy storage comprising a liquid imperious enclosure having disposed therein a composition comprising a water/urea phase change material contained in a particulate silica matrix, said water/urea phase change material being 80% -54.5% by weight water and 20% -45.5% by weight urea, said phase change material having a thermal energy storage of greater than 50 cal/gm and a melting and a freezing point in the range of -11° C. to -15° C., and said particulate silica matrix being present in said composition in an amount of from 30 to 40% by weight while said water/urea phase change material is present in said composition in an amount of from 70 to 60% by weight.
Claim 7
Dependent Claim
118 words
An article for use in thermal energy storage comprising a liquid imperious enclosure having disposed therein a composition comprising a water/urea phase change material contained in a particulate silica matrix, said water/urea phase change material being 80% -54.5% by weight water and 20% -45.5% by weight urea, said phase change material having a thermal energy storage of greater than 50 cal/gm and a melting and a freezing point in the range of -11° C. to -15° C., and said particulate silica matrix being present in said composition in an amount of from 30 to 40% by weight while said water/urea phase change material is present in said composition in an amount of from 70 to 60% by weight.
Claim 8
Dependent Claim
16 words
The article of claim 5 wherein said liquid impervious enclosure is made of a polymeric material.
Claim 9
Dependent Claim
23 words
The article of claim 6 wherein said liquid impervious enclosure is a polymeric envelope and said article is useful as a medical wrap.
Claim 10
Dependent Claim
23 words
The article of claim 5 wherein said liquid impervious enclosure is a plastic housing and said article is useful as a tableware item.
Claim 11
Dependent Claim
25 words
The article of claim 5 wherein said water/urea phase change material comprises less than 75% by weight water and at least 25% by weight urea.
Claim 12
Dependent Claim
30 words
The article of claim 5 wherein said particulate silica matrix is a hydrophobic silica which has been surface treated with 1-15 parts per hundred by weight of a silicone resin.
Claim 13
Dependent Claim
21 words
The article of claim 5 wherein said water/urea phase change material has a thermal energy storage of greater than 60 cal/gm.
References Cited (Backward Citations)
US3640698A
Cited
US3874504A
Cited
US4533483A
Cited
US4025444A
Cited
US4008170A
Cited
US4207885A
Cited
US4237023A
Cited
US4579580A
Cited
US4488817A
Cited
US4797160A
Cited
US4825939A
Cited
US4711813A
Cited
US5053446A
Cited
US5106520A
Cited
US4659629A
Cited
US5028270A
Cited
US4988543A
Cited
US5211949A
Cited
US5282994A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-06-12 | 1998-12-12 | 1999-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-06-12 | 2002-12-12 | 2003-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-06-12 | 2006-12-12 | 2007-06-13 | $7700.00 | Window Closed / Lapsed |