Closed-cell tannin-based foams

Patent metadata

Field	Value
Publication number	US-9701803-B2
Application number	US-201214118906-A
Country	US
Kind code	B2
Filing date	May 25, 2012
Priority date	May 25, 2011
Publication date	Jul 11, 2017
Grant date	Jul 11, 2017

Abstract

Disclosed are foam compositions and processes to form closed-cell tannin-based foams. The foams comprises a continuous polymeric phase defining a plurality of cells, wherein the continuous polymeric phase comprises a tannin-based resin derived from a tannin, a first monomer, and a second monomer, wherein the first monomer comprises formaldehyde, paraformaldehyde, furfural, glyoxal, acetaldehyde, 5-hydroxymethylfurfural, acrolein, levulinate esters, sugars, 2,5-furandicarboxylic acid, 2,5-furandicarboxylic aldehyde, urea, difurfural (DFF), or mixtures thereof, and the second monomer comprises furfuryl alcohol, glycerol, sorbitol, lignin, or mixtures thereof, and wherein the plurality of cells comprises a plurality of open-cells and a plurality of closed-cells with an open-cell content measured according to ASTM D6226-5, of less than 50%. The foam composition also comprises a discontinuous phase disposed in at least a portion of the plurality of closed-cells, the discontinuous phase comprising one or more blowing agents.

First claim

What is claimed is:

1. A foam consisting of:
(a) a continuous polymeric phase defining a plurality of cells, wherein:
the continuous polymeric phase consists of co-reacting components a tannin-based resin derived from a tannin, a furfuryl alcohol, and a first monomer, wherein the first monomer comprises formaldehyde, paraformaldehyde, furfural, glyoxal, acetaldehyde, 5-hydroxymethylfurfural, acrolein, levulinate esters, sugars, 2,5-furandicarboxylic acid, 2,5-furandicarboxylic aldehyde, urea, difurfural (DFF), or mixtures thereof, and
the plurality of cells comprises a plurality of open-cells and a plurality of closed-cells with an open-cell content measured according to ASTM 6226-5, of less than 40%; and

(b) a gas phase comprising one or more blowing agents disposed in at least a portion of the plurality of closed-cells.

2. The foam of claim 1 , wherein the tannin-based resin is derived from a tannin, a first monomer, and furfuryl alcohol present as reactants in a weight ratio in the range of 1:0.01:0.1 to 1:2:5.

3. The foam of claim 1 , wherein the open-cell content measured according to ASTM D6226-5, is less than 20%.

4. The foam of claim 1 , wherein the open-cell content measured according to ASTM D6226-5, is less than 30%.

5. The foam of claim 1 , wherein the foam has a density in the range of 10-500 kg/m 3 .

6. The foam of claim 1 , wherein the foam has a density in the range of 20-100 kg/m 3 .

7. The foam of claim 1 , wherein the cell has an average size of less than 500 microns.

8. The foam of claim 1 , wherein at least one of the one or more blowing agents has a gas phase thermal conductivity of less than or equal to 0.016 W/m·K at 25° C.

9. The foam of claim 1 , wherein at least one of the one or more blowing agents comprises 1,1,1,4,4,4-hexafluoro-2-butene, carbon dioxide, pentane, isopentane, cyclopentane petroleum ether, ether, 1,1-dichloro-1-fluoroethane, 2,2-dichloro-1,1,1-trifluoroethane, 1-chloro-1,1-difluoroethane, 1,1,1,2-tetrafluoroethane, 1,1,1,3,3-pentafluoropropane, 1,1,1,3,3-pentafluorobutane, 2-chloropropane, dichlorodifluoromethane, 1,2-dichloro-1,1,2,2-tetrafluoroethane, trichlorotrifluoroethane, trichloromonofluoromethane, or mixtures thereof.

10. The foam of claim 1 , wherein the foam has a thermal conductivity in the range of 0.015-0.050 W/m·K.

11. The foam of claim 1 , wherein the continuous polymeric phase further comprises one or more additives.

12. The foam of claim 11 , wherein the one or more additives comprises cellulose fiber, bacterial cellulose, sisal fiber, clays, Kaolin-type clay, mica, vermiculite, sepiolite, hydrotalcite and other inorganic platelet materials, glass fibers, polymeric fibers, alumina fibers, aluminosilicate fibers, carbon fibers, carbon nanofibers, poly-1,3-glucan, lyocel fibers, chitosan, boehmite (AlO.OH), zirconium oxide, a polyester polyol, or mixtures thereof.

13. The foam of claim 1 , wherein the tannin is derived from mimosa, acacia, quebracho, pine, spruce, fir, tanoak, oak, birch, maple, eucalyptus, tara, catechu, or mixtures thereof.

14. The foam of claim 1 , wherein the foam has a limiting oxygen index (LOI) of at least 23, measured according to ASTM-D2863.

15. An article comprising the foam of claim 1 .

16. The article of claim 15 comprising a sandwich panel structure, wherein the sandwich panel structure comprises the foam disposed between two similar or dissimilar non-foam materials.

17. The article of claim 16 wherein the non-foam material comprises polymeric fibers.

Assignees

• Cobb Michael W
• Galante Vincent
• Harmer Mark Andrew
• Kapur Vivek
• Williams Sharlene Renee
• Du Pont

Inventors

• Cobb Michael W
• Galante Vincent
• Harmer Mark Andrew
• Kapur Vivek
• Williams Sharlene Renee

Classifications

• B32B2266/02

  Organic · CPC title

• B32B2266/0228

  Aromatic vinyl resin, e.g. styrenic (co)polymers · CPC title

• B32B15/18

  comprising iron or steel {(B32B15/011, B32B15/012 and B32B15/013 take precedence)} · CPC title

• C08J9/12 Primary

  by a physical blowing agent · CPC title

• B32B27/34

  comprising polyamides · CPC title