Foams based on thermoplastic polyurethanes

Patent metadata

Field	Value
Publication number	US-11292887-B2
Application number	US-202017031225-A
Country	US
Kind code	B2
Filing date	Sep 24, 2020
Priority date	Jan 18, 2006
Publication date	Apr 5, 2022
Grant date	Apr 5, 2022

Abstract

Expandable thermoplastic polyurethane comprising blowing agent, wherein the Shore hardness of the thermoplastic polyurethane is from A 44 to A 84.

First claim

The invention claimed is:

1. A method of making a sole for an article of footwear, the method comprising:
impregnating thermoplastic polyurethane pellets with a blowing agent in aqueous suspension under pressure to form thermoplastic polyurethane beads;
depressurizing the thermoplastic polyurethane beads to allow the thermoplastic polyurethane beads to expand; and
fusing the expanded thermoplastic polyurethane beads to one another to form the sole.

2. The method of claim 1 , wherein the impregnating occurs at a temperature of at least 100° C.

3. The method of claim 2 , wherein the temperature is between 100° C. and 150° C.

4. The method of claim 2 , wherein the temperature is between 110° C. and 145° C.

5. The method of claim 2 , wherein the depressurizing occurs without cooling the thermoplastic polyurethane beads.

6. The method of claim 1 , wherein the impregnating occurs at a pressure between 2 bar and 100 bar.

7. The method of claim 1 , wherein a time for the impregnating is between 0.5 hours and 10 hours.

8. The method of claim 1 , further comprising cooling the thermoplastic polyurethane beads before the depressurizing.

9. The method of claim 8 , wherein the cooling results in a temperature between 20° C. and 95° C.

10. The method of claim 1 , wherein the blowing agent comprises organic liquids.

11. The method of claim 1 , wherein the blowing agent comprises inorganic gases.

12. The method of claim 1 , wherein the blowing agent comprises between 0.1% and 40% of the total weight of the thermoplastic polyurethane pellets.

13. The method of claim 1 , wherein the sole comprises a midsole.

14. The method of claim 1 , wherein the sole comprises an insole.

15. The method of claim 1 , wherein the expanded thermoplastic polyurethane beads have a diameter between 0.2 mm and 20 mm.

16. The method of claim 1 , wherein the expanded thermoplastic polyurethane beads are spherical.

17. The method of claim 1 , wherein fusing the expanded thermoplastic polyurethane beads to one another to form the sole comprises placing the expanded thermoplastic polyurethane beads in a closed mold and exposing the expanded thermoplastic polyurethane beads to a temperature between 100° C. and 140° C.

18. The method of claim 1 , wherein the expanded thermoplastic polyurethane beads have a density between 5 g/l and 600 g/l.

Assignees

• Basf Se

Inventors

• Prissok Frank
• Braun Frank

Classifications

• B29B9/065

  under-water, e.g. underwater pelletizers · CPC title

• A43B13/187

  Resiliency achieved by the features of the material, e.g. foam, non liquid materials · CPC title

• A43B17/14

  made of sponge, rubber, or plastic materials · CPC title

• C08G18/4854

  Polyethers containing oxyalkylene groups having four carbon atoms in the alkylene group · CPC title

• A43B13/023

  Soles with several layers of the same material · CPC title