Composite polyurethane foams and method of manufacture thereof

• US 6,635,688 B2
• Filed: 06/27/2001
• Issued: 10/21/2003
• Est. Priority Date: 06/28/2000
• Status: Expired due to Term

• Current Assignee: World Properties Incorporated
• Original Assignee: World Properties Incorporated
• Inventors: Simpson, Scott S.
• Primary Examiner(s): COONEY, JOHN M
• Application Number:
  US09/892,899
• Publication Number:
  US 20020028325A1
• Time in Patent Office: 846 Days
• Field of Search: 521/155, 521/170, 521/174, 428/423.3
• US Class Current: 521/170
• CPC Class Codes: A43B 13/12 Soles with several layers of different materials
• CPC Class Codes: A43B 13/187 Resiliency achieved by the features of the material, e.g. foam, non liquid materials
• CPC Class Codes: A43B 17/02 wedge-like or resilient
• CPC Class Codes: A43B 17/14 made of sponge, rubber, or plastic materials
• CPC Class Codes: B29C 44/0461 by having different chemical compositions in different places, e.g. having different concentrations of foaming agent, feeding one composition after the other
• CPC Class Codes: B32B 27/40 comprising polyurethanes
• CPC Class Codes: B32B 5/32 at least two layers being foamed and next to each other
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/24992 Density or compression of components
• CPC Class Codes: Y10T 428/249981 Plural void-containing components
• CPC Class Codes: Y10T 428/31554 Next to second layer of polyamidoester

Abstract

Integrally bonded composite polyurethane foams substantially free from coalescence and with no discernable bond or structural interface layer when viewed at 50× magnification can be formed by wet casting a second foamed polyurethane composition onto a first wet cast foamed polyurethane composition and simultaneously curing the cast foams. In a preferred embodiment, one curable polyurethane composition forms a slow recovery foam and the other curable polyurethane composition forms a resilient foam.

Claims

1. A method for the manufacture of multiple layer polyurethane foams, which comprises:

casting a first, foamed mixture comprising an organic isocyanate component, an active hydrogen-containing component reactive with the isocyanate component, a surfactant, and a catalyst onto a second, foamed mixture comprising an organic isocyanate component, an active hydrogen-containing component reactive with the isocyanate component, a surfactant, and a catalyst; and

curing the resulting multiple layers to form a multiple layer, polyurethane foam having no discernible structural interface line between the layers when viewed at 50×

magnification by SEM.

2. A method of claim 1, wherein the first and second mixture each have a different composition.

3. The method of claim 1, wherein one of the curable polyurethane composition forms a resilient foam;

and the other of the curable polyurethane composition forms a slow recovery foam.

4. The method of claim 1, further comprising casting a third foamed mixture comprising an organic isocyanate component, an active hydrogen-containing component reactive with the isocyanate component, a surfactant, and a catalyst onto the second layer prior to cure.

5. A multiple layer, polyurethane foam, comprising

a first polyurethane foam layer;

and

a second polyurethane foam layer, wherein there is no discernible structural interface line between the layers when viewed at 50×

magnification by SEM.

6. The multiple layer, polyurethane foam of claim 5, wherein the first and second layers each have a different composition.

7. The multiple layer, polyurethane foam of claim 5, wherein one of the layers is a resilient foam;

and the other of the layers is a slow recovery foam.

8. The multiple layer, polyurethane foam of claim 5, further comprising a third polyurethane foam layer, wherein there is no discernible structural interface line between the third layer and the layer on which it is disposed when viewed at 50×

magnification by SEM.

10. The multiple layer, polyurethane foam of claim 8, wherein the first and second layers each have a different composition.

11. The multiple layer, polyurethane foam of claim 8, wherein one of the layers is a resilient foam;

and the other of the layers is a slow recovery foam.

12. The multiple layer, polyurethane foam of claim 8, further comprising a third polyurethane foam layer disposed on the first or second layers, wherein one or more cells span the boundary region between the layers.

13. An article comprising the foam of any one of claims 4-12.

14. A shoe insert comprising any one of the multiple layer foams of claims 4-12.

9. A multiple layer, polyurethane foam, comprising

a first polyurethane foam layer;

and

a second polyurethane foam layer disposed on the first layer, wherein one or more cells span the boundary region between the layers wherein there is no discernible structural interface line between the layers when viewed at 50×

magnification by SEM.