Methods for preparing open-celled polyurethane foams, systems for use therein, and open-celled polyurethane foams produced thereby

Patent metadata

Field	Value
Publication number	US-10494498-B2
Application number	US-201816217464-A
Country	US
Kind code	B2
Filing date	Dec 12, 2018
Priority date	Jun 8, 2015
Publication date	Dec 3, 2019
Grant date	Dec 3, 2019

Abstract

Disclosed are methods and systems for preparing open-celled polyurethane foams by a discontinuous box foam process in which (a) a polyurethane foam-forming composition is deposited into a container having a gas-permeable base and (b) the polyurethane-foam forming composition is allowed to form an open-celled polyurethane foam in the container. In these methods and systems, the gas-permeable base is heated before, during, and/or after step (a) and heating is continued during at least a portion of step (b).

First claim

What is claimed is:

1. A method for preparing an open-celled polyurethane foam, comprising:
(a) depositing a polyurethane foam-forming composition into a box comprising a gas-permeable base and at least 4 sidewalls; and
(b) allowing the polyurethane-foam forming composition to form an open-celled polyurethane foam in the container,
wherein during step (a) and during step (b) the temperature of the gas-permeable base is maintained at least 10° C. higher than the temperature of other portions of the box, and
wherein the method is discontinuous.

2. The method of claim 1 , wherein the temperature of the gas-permeable base is maintained at least 10° C. higher than the temperature of other portions of the box during the entire period of time from the emergence of the first amount of foam-forming composition from a mixing head through a degas process.

3. The method of claim 1 , wherein the gas-permeable base is constructed of cardboard.

4. The method of claim 1 , wherein the temperature of the gas-permeable base is maintained at least 10° C. higher than the temperature of other portions of the box during step (b) by heating the base with a heating pad, matt or plate disposed beneath the base.

5. The method of claim 4 , wherein during step (b) the temperature of the gas-permeable base is maintained 10° C. to 50° C. higher than the temperature of other portions of the box.

6. The method of claim 5 , wherein only the base of the container is heated.

7. The method of claim 6 , wherein the base is heated to a temperature of at least 30° C. and up to 120° C.

8. The method of claim 7 , wherein the base is heated to a temperature of at least 35° C. and up to 65° C.

9. The method of claim 5 , wherein the base is heated to a temperature of at least 10° C. higher than the temperature of the ambient air in which the container is disposed.

10. The method of claim 1 , wherein the open-celled polyurethane foam is in the form of a bun having a foam density at one side of the bun that is higher than the density of the remaining portions of the bun.

11. The method of claim 1 , wherein the open-celled polyurethane foam is obtained by reacting a polyisocyanate component with a polyol component which comprises:
(i) a polyether polyol having a functionality of from 2 to 6 and a number average molecular weight of more than 160 to 6500;
(ii) a chain extending agent and/or crosslinking agent containing at least two isocyanate-reactive groups and having a molecular weight of from 60 to 160,
(iii) water, and
(iv) a catalyst for polyurethane formation.

Assignees

• Covestro Llc

Inventors

• Lee Bin
• Barley Paul O

Classifications

• B29K2911/12

  Paper, e.g. cardboard · CPC title

• C08G18/4841

  containing oxyethylene end groups · CPC title

• B29K2105/24

  crosslinked or vulcanised · CPC title

• B29K2995/0063

  Density · CPC title

• B29K2105/045

  with open cells · CPC title