Dry powder mixes comprising phase change materials

• US 5,254,380 A
• Filed: 03/17/1993
• Issued: 10/19/1993
• Est. Priority Date: 11/22/1985
• Status: Expired due to Term

• Current Assignee: University of Dayton
• Original Assignee: University of Dayton
• Inventors: Salyer, Ival O.
• Primary Examiner(s): Lilling, Herbert J.
• Application Number:
  US08/048,324
• Time in Patent Office: 216 Days
• Field of Search: 428/36.4, 428/36.2, 428/402, 428/36.92, 428/35.7, 126/400, 126/246, 252/70, 524/493
• US Class Current: 428/35.7
• CPC Class Codes: A01G 13/0237 Devices for protecting a specific part of a plant, e.g. roots, trunk or fruits
• CPC Class Codes: A47G 9/0215 with cooling or heating means electric blankets H05B3/34
• CPC Class Codes: A61F 2007/0238 in a pocket A61F2007/023 takes precedence
• CPC Class Codes: A61F 2007/0242 heated by microwaves
• CPC Class Codes: A61F 2007/0261 medicated
• CPC Class Codes: A61F 2007/0268 having a plurality of compartments being filled with a heat carrier heat packs stored in pockets A61F2007/023, A61F2007/0238
• CPC Class Codes: A61F 7/02 Compresses or poultices for effecting heating or cooling
• CPC Class Codes: A61L 24/02 containing inorganic materials
• CPC Class Codes: A61L 26/0004 containing inorganic materials
• CPC Class Codes: C08K 3/36 Silica
• CPC Class Codes: C08K 5/01 Hydrocarbons C08K5/0091 takes precedence
• CPC Class Codes: C08L 23/06 Polyethene
• CPC Class Codes: C08L 91/06 Waxes
• CPC Class Codes: C09K 5/063 Materials absorbing or liberating heat during crystallisation; Heat storage materials
• CPC Class Codes: F16D 2065/781 involving phase change of material
• CPC Class Codes: F16D 65/78 Features relating to cooling
• CPC Class Codes: F16D 66/00 Arrangements for monitoring working conditions, e.g. wear, temperature
• CPC Class Codes: F16D 69/02 Composition of linings ; Methods of manufacturing
• CPC Class Codes: F28D 20/02 using latent heat
• CPC Class Codes: F28D 20/023 the latent heat storage material being enclosed in granular particles or dispersed in a porous, fibrous or cellular structure
• CPC Class Codes: H05K 5/0209 : Thermal insulation, e.g. for fire protection or for fire containment or for high temperature environments
• CPC Class Codes: H05K 5/0213 : Venting apertures; Constructional details thereof
• CPC Class Codes: Y02E 60/14 : Thermal energy storage
• CPC Class Codes: Y10T 428/1352 : Polymer or resin containing [i.e., natural or synthetic]
• CPC Class Codes: Y10T 428/1366 : Textile, fabric, cloth, or pile is sandwiched between two distinct layers of material unlike the textile, fabric, cloth, or pile layer
• CPC Class Codes: Y10T 428/1372 : Randomly noninterengaged or randomly contacting fibers, filaments, particles, or flakes
• CPC Class Codes: Y10T 428/1397 : Single layer [continuous layer]
• CPC Class Codes: Y10T 428/2982 : Particulate matter [e.g., sphere, flake, etc.]

Abstract

Free flowing, conformable powder-like mix of silica particles and a phase change material (p.c.m.) is disclosed. The silica particles have a critical size of about 7×10^-3 to about 7×10^-2 microns and the pcm must be added to the silica in an amount of 80 wt. % or less pcm per combined weight of silica and pcm. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garmets, quilts and blankets, and in cementitious compositions of the type in which it is beneficial to use a pcm material. The silica-pcm mix can also be admixed with soil to provide a soil warming effect and placed about a tree, flower, or shrub.

Claims

1. A food receptacle or beverage container receptacle comprising a housing, and a powder-like mix consisting essentially of a phase change material and finely divided silica particles, in combination, disposed in said housing, said silica particles having particle sizes of about 7×

10^-3 to about 7×

10^-2 microns, said phase change material being selected from the group consisting of water, glycerine, ethylene glycol, crystalline alkyl hydrocarbons having a carbon chain length of C₁₄ and greater, crystalline fatty acids, crystalline fatty acid esters, crystalline alicyclic hydrocarbons, crystalline aromatic compounds, hydrated salts, clathrates, semi-clathrates, gas clathrates, polyethylene glycol, and halogen-terminated alkyl hydrocarbons, said phase change material having a melting and freezing point of from about -20°

to about 80°

C. and being present in an amount of 80% or less by weight and said silica particles being present in an amount of 20% or more by weight based on the total weight of the combination of phase change material and silica particles.

2. A food receptacle or beverage container receptacle as recited in claim 1 wherein said silica particles have a surface area of between about 50 m² /g to about 500 m² /g.

3. A food receptacle or beverage container receptacle as recited in claim 1 wherein said silica particles are selected from the group consisting of fumed and precipitated silicas.

4. A food receptacle or beverage container receptacle as recited in claim 1 wherein said silica particles are hydrophilic precipitated silica particles or hydrophobic silica particles.

5. A food receptacle or beverage container receptacle as recited in claim 1 wherein said phase change material is present in an amount of 50-80 wt. % based upon the combined weight of said phase change material and said silica particles.

6. A food receptacle or beverage container receptacle as recited in claim 1 further comprising a polar compound present in an amount of 5-25 wt. % based on the total weight of said silica, said phase change material and said polar compound, and wherein said receptacle may be heating by microwave energy.

7. A food receptacle or beverage container receptacle as recited in claim 1 wherein said phase change material comprises a polar phase change material compound and wherein said receptacle may be heated by microwave energy.

8. A food receptacle or beverage container receptacle as recited in claim 7 wherein said polar phase change material is chosen from the group consisting of water, glycerine, ethylene glycol, polyethylene glycol having a molecular weight of about 1,000 or greater, clathrates, semi-clathrates, gas clathrates, and hydrated salts.

9. A food receptacle or beverage container receptacle as recited in claim 1 wherein said phase change material is water.

10. A food receptacle or beverage container receptacle as recited in claim 1 wherein said phase change material comprises a crystalline alkyl hydrocarbon having a carbon chain length of C₁₄ and greater.