Foamed articles exhibiting improved thermal properties

Patent metadata

Field	Value
Publication number	US-9815957-B2
Application number	US-201414495340-A
Country	US
Kind code	B2
Filing date	Sep 24, 2014
Priority date	Jun 11, 2010
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

Cellular and multi-cellular polystyrene and polystyrenic foams and methods of forming such foams are disclosed. The foams include an expanded polystyrene formed from expansion of an expandable polystyrene including an adsorbent comprising alumina, wherein the multi-cellular polystyrene exhibits a multi-cellular size distribution. The process for forming a foamed article includes providing a formed styrenic polymer and contacting the formed styrenic polymer with a first blowing agent and an adsorbent comprising alumina to form extrusion polystyrene. The process further includes forming the extrusion styrenic polymer into an expanded styrenic polymer and forming the expanded styrenic polymer into a foamed article.

First claim

What is claimed is:

1. Multi-cellular polystyrene comprising:
expanded polystyrene formed from expansion of a blend comprising an expandable polystyrene, at least one blowing agent, wherein the at least one blowing agent is water, or water and carbon dioxide, and an adsorbent comprising alumina, wherein the multi-cellular polystyrene is bi-cellular comprising small cells and large cells, wherein the small cells have an average cellular size of between 25 and 40 microns, large cells have an average cellular size of from about 150 to about 900 microns, and wherein the number of the small cells having an average cellular size of between 25 and 40 microns is about 90% of a total of the number of the small cells and the large cells.

2. The multi-cellular polystyrene of claim 1 , wherein the expandable polystyrene comprises a reflective additive having a particle size of between 0.1 μm to 10 μm.

3. The multi-cellular polystyrene of claim 1 , wherein the multi-cellular polystyrene comprises struts and cell walls, and wherein the alumina is dispersed within the struts and cell walls, wherein the alumina has broken into sub-micron particles.

4. The multi-cellular polystyrene of claim 1 , wherein the alumina is between 5 and 150 microns in size.

5. The multi-cellular polystyrene of claim 1 , wherein the adsorbent exhibits a surface area of at least 90 m 2 /g.

6. The multi-cellular polystyrene of claim 1 , wherein no surfactant is present in the multi-cellular polystyrene.

7. The multi-cellular polystyrene of claim 1 , wherein the CO 2 is supercritical CO 2 .

8. The multi-cellular polystyrene of claim 1 , wherein CO 2 is present in the blend at a concentration of from about 2 wt. % to about 5 wt. %, wherein the water is present in the blend at a concentration of from about 0.5 wt. % to about 3 wt. %, and wherein the alumina is present in the blend in an amount ranging from about 0.5 to about 4 wt. %.

9. The multi-cellular polystyrene of claim 1 , wherein a portion of the water is present as free water in the blend, and wherein a portion of the water in the blend is absorbed on the alumina.

10. The multi-cellular polystyrene of claim 9 , wherein the expanded polystyrene is formed under conditions sufficient to vaporize the free water to form large cells in the expanded polystyrene and to desorb the absorbed water to form small cells in the expanded polystyrene.

11. The multi-cellular polystyrene of claim 1 , wherein a majority of cells in the multi-cellular polystyrene are closed.

12. Multi-cellular polystyrene comprising:
expanded polystyrene formed from expansion of a blend comprising an expandable polystyrene, at least one blowing agent, wherein the at least one blowing agent is water, or water and carbon dioxide, and alumina, wherein the multi-cellular polystyrene is bi-cellular comprising small cells and large cells, wherein the small cells have an average cellular size of between 25 and 40 microns, large cells have an average cellular size of from about 150 to about 900 microns, and wherein the number of the small cells having an average cellular size of between 25 and 40 microns is about 90% of a total of the number of the small cells and the large cells.

13. An article comprising:
Bi-cellular expanded polystyrene comprising small cells and large cells, wherein the expanded polystyrene is formed from expansion of a blend comprising an expandable polystyrene, water, and alumina, wherein a portion of the water is present as free water in the blend, wherein a portion of the water in the blend is absorbed on the alumina, and wherein the expanded polystyrene is formed under conditions sufficient to vaporize the free water to form the large cells in the expanded polystyrene and to desorb the absorbed water to form the small cells in the expanded polystyrene, wherein the small cells have an average cellular size of between 25 and 40 microns, large cells have an average cellular size of from about 150 to about 900 microns and wherein the number of the small cells having an average cellular size of between 25 and 40 microns is about 90% of a total of the number of the small cells and the large cells.

14. The multi-cellular polystyrene of claim 1 , wherein the expandable polystyrene is a copolymer of styrene monomers and comonomers selected from the group consisting of hydroxyethylmethacrylate, glycidyl methacrylate, polyvinyl acetate, caprolactone acrylate, and combinations thereof.

Assignees

• Fina Technology

Inventors

• Sosa Jose M
• Knoeppel David W

Classifications

• C08J2203/10

  Water or water-releasing compounds · CPC title

• C08J2203/182

  of physical blowing agents, e.g. acetone and butane · CPC title

• C08J2203/06

  CO2, N2 or noble gases · CPC title

• C08J2205/048

  Bimodal pore distribution, e.g. micropores and nanopores coexisting in the same foam · CPC title

• C08J9/125

  Water, e.g. hydrated salts · CPC title