Dry powder mixes comprising phase change materials

• US 5,106,520 A
• Filed: 01/09/1990
• Issued: 04/21/1992
• 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:
  US07/462,365
• Time in Patent Office: 833 Days
• Field of Search: 252/70, 252/69, 524/5, 524/8, 524/493, 428/403, 428/402
• US Class Current: 252/70
• CPC Class Codes: A01G 13/0237 Devices for protecting a specific part of a plant, e.g. roots, trunk or fruits
• CPC Class Codes: A41D 13/005 with controlled temperature
• 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
• 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 428/2982 : Particulate matter [e.g., sphere, flake, etc.]
• CPC Class Codes: Y10T 428/2991 : Coated

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, garments, 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 composition comprising, in combination, a mixture of a phase change material and finely divided silica particles, said silica particles having particle sizes of about 7×

10^-3 to about 7×

10^-2 microns, said phase change material comprising a crystalline alkyl hydrocarbon having a carbon chain length of C₁₄ and greater 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 phase change material and silica particles in said mixture.

2. The composition as recited in claim 1 wherein said composition is in the form of a freely flowing powder-like mixture.

3. The composition as recited in claim 2 wherein said phase change material has a melting and freezing point of from about -20°

to 140°

C.

4. The composition as recited in claim 3 wherein said phase change material is present in an amount of 50-80 wt. %.

5. The composition as recited in claim 1 further including a polar compound present in said mixture in an amount of 5-25 wt. % based on the total weight of said composition.

6. The composition as recited in claim 1 further including a cementitious material into which said mixture is dispersed.

7. The composition as recited in claim 6 wherein said silica particles comprise a hydrophobic silica.