Method of making coextruded, cross-linked polyolefin foam with TPU cap layers

Patent metadata

Field	Value
Publication number	US-11628657-B2
Application number	US-202117185152-A
Country	US
Kind code	B2
Filing date	Feb 25, 2021
Priority date	Mar 31, 2017
Publication date	Apr 18, 2023
Grant date	Apr 18, 2023

Abstract

The present disclosure is directed to a physically crosslinked, closed cell continuous multilayer foam structure comprising at least one foam polypropylene/polyethylene layer with a TPU cap layer. The multilayer foam structure can be obtained by coextruding a multilayer structure comprising at least one foam composition layer with at least one cap composition layer, irradiating the coextruded structure with ionizing radiation, and continuously foaming the irradiated structure.

First claim

The invention claimed is:

1. A multilayer foam structure comprising:
a coextruded foam layer comprising a chemical foaming agent and polypropylene, polyethylene, or a combination of polypropylene and polyethylene; and
a coextruded cap layer on a side of the foam layer, the cap layer comprising:
at least 55 wt % thermoplastic polyurethane (TPU); and
20-25 wt. % polyether amine modified polypropylene, polyether amine modified polyethylene, or a combination of polyether amine modified polypropylene and polyether amine modified polyethylene.

2. The multilayer foam structure of claim 1 , wherein the coextruded foam layer comprises 5-20 wt % TPU.

3. The multilayer foam structure of claim 1 , wherein the coextruded foam layer comprises at least 70 wt % polypropylene, polyethylene, or a combination of polypropylene and polyethylene.

4. The multilayer foam structure of claim 1 , wherein the foam layer comprises additives in an amount of 1-15 wt %.

5. The multilayer foam structure of claim 1 , wherein the cap layer comprises additives in an amount of 1-8 wt %.

6. The multilayer foam structure of claim 1 , wherein the density of the multilayer foam structure is 20-250 kg/m 3 .

7. The multilayer foam structure of claim 1 , wherein the multilayer foam structure has a crosslinking degree of 20-75%.

8. The multilayer foam structure of claim 1 , wherein the multilayer foam structure has an average closed cell size of 0.05-1.0 mm.

9. The multilayer foam structure of claim 1 , wherein the multilayer foam structure has a thickness of 0.2-50 mm.

10. A laminate comprising:
a multilayer foam structure comprising:
a coextruded foam layer comprising a chemical foaming agent and polypropylene, polyethylene, or a combination of polypropylene and polyethylene; and
a coextruded cap layer on a side of the foam layer, the cap layer comprising:
at least 55 wt % thermoplastic polyurethane (TPU); and
20-25 wt. % polyether amine modified polypropylene, polyether amine modified polyethylene, or a combination of polyether amine modified polypropylene and polyether amine modified polyethylene; and

a laminate layer on a side of the cap layer opposite the foam layer.

11. The laminate of claim 10 , wherein the laminate layer comprises urethane based adhesives, polyurethane foams, or reacting urethane foams.

12. The laminate of claim 10 , wherein the coextruded foam layer comprises 5-20 wt % TPU.

13. The laminate of claim 10 , wherein the coextruded foam layer comprises at least 70 wt % polypropylene, polyethylene, or a combination of polypropylene and polyethylene.

14. The laminate of claim 10 , wherein the foam layer comprises additives in an amount of 1-15 wt %.

15. A flooring system comprising:
a top floor layer;
a sub-floor layer; and
at least one underlayment layer disposed between the sub-floor layer and the top floor layer, wherein the at least one underlayment layer comprises a multilayer foam structure comprising:
a coextruded foam layer comprising a chemical foaming agent and polypropylene, polyethylene, or a combination of polypropylene and polyethylene; and
a coextruded cap layer on a side of the foam layer, the cap layer comprising:
at least 55 wt % thermoplastic polyurethane (TPU); and
20-25 wt. % polyether amine modified polypropylene, polyether amine modified polyethylene, or a combination of polyether amine modified polypropylene and polyether amine modified polyethylene.

Assignees

• Toray Plastics America Inc

Inventors

• Ben-Daat Dan
• Baldwin Jesse Jude
• Bock Kaitlyn Michelle
• Sieradzki Pawel

Classifications

• B29K2075/00

  Use of {PU, i.e.} polyureas or polyurethanes {or derivatives thereof}, as moulding material · CPC title

• C08J7/123

  Treatment by wave energy or particle radiation (C08J7/18 takes precedence) · CPC title

• B29K2995/0063

  Density · CPC title

• B29C48/25

  Component parts, details or accessories; Auxiliary operations · CPC title

• B32B2250/03

  3 layers · CPC title