Thermoplastic polyurethane film and preparation method thereof

Patent metadata

Field	Value
Publication number	US-11299624-B2
Application number	US-201816494558-A
Country	US
Kind code	B2
Filing date	Mar 27, 2018
Priority date	Mar 27, 2017
Publication date	Apr 12, 2022
Grant date	Apr 12, 2022

Abstract

A thermoplastic polyurethane film including a cured product of a polyurethane resin composition is provided. The polyurethane resin composition includes a polyurethane resin, a first isocyanate-based curing agent, and an organic solvent. The thermoplastic polyurethane film has a tensile strength break of 50 MPa to 80 MPa. A method for preparing the thermoplastic polyurethane film is also provided.

First claim

The invention claimed is:

1. A thermoplastic polyurethane film comprising:
a cured product of a polyurethane resin composition, wherein the polyurethane resin compositon comprises
a polyurethane resin,
a first isocyanate-based curing agent, and
an organic solvent,
wherein the thermoplastic polyurethane film has a tensile strength at break of 50 MPa to 80 MPa,
wherein a content of the first isocyanate-based curing agent is 7.5 parts by weight to 15 parts by weight based on 100 parts by weight of the polyurethane resin.

2. The thermoplastic polyurethane film of claim 1 , wherein the first isocyanate-based curing agent comprises two to six isocyanate functional groups.

3. The thermoplastic polyurethane film of claim 1 , wherein the polyurethane resin is a copolymer of a mixture comprising:
a polyol having a number average molecular weight of 1,800 g/mol to 2,200 g/mol;
a chain extender comprising a diol having 4 to 10 carbon atoms; and
a second isocyanate-based curing agent.

4. The thermoplastic polyurethane film of claim 3 , wherein a content of the polyol is 50 wt % to 75 wt % based on a weight of the mixture.

5. The thermoplastic polyurethane film of claim 3 , wherein a content of the chain extender is 5 wt % to 15 wt % based on a weight of the mixture.

6. The thermoplastic polyurethane film of claim 3 , wherein a content of the second isocyanate-based curing agent is 20 wt % to 37.5 wt % based on a weight of the mixture.

7. The thermoplastic polyurethane film of claim 1 , wherein a content of a solid content of the polyurethane resin composition is 20% to 70%.

8. The thermoplastic polyurethane film of claim 1 , wherein the thermoplastic polyurethane film has a thickness of 10 μm to 250 μm.

9. A method for preparing the thermoplastic polyurethane film according to claim 1 , comprising:
preparing a polyurethane resin composition comprising a polyurethane resin, a first isocyanate-based curing agent, and an organic solvent;
forming a polyurethane resin layer by applying the polyurethane resin composition onto a substrate film and heat-treating the polyurethane resin composition; and
additionally curing the polyurethane resin layer.

10. The method of claim 9 , wherein the heat-treating is carried out at a temperature of 100° C. to 150° C.

11. The method of claim 9 , wherein the additional curing is carried out at a temperature of 40° C. to 80° C. for 12 hours to 48 hours.

12. The method of claim 9 , wherein the polyurethane resin is prepared by carrying out a copolymerization reaction of a mixture, wherein the mixture comprises:
a polyol having a number average molecular weight of 1,800 g/mol to 2,200 g/mol;
a chain extender comprising a diol having 4 to 10 carbon atoms; and
a second isocyanate-based curing agent, in an organic solvent.

13. The method of claim 12 , wherein the copolymerization reaction is carried out at a temperature of 50° C. to 70° C.

Assignees

• Lg Chemical Ltd

Inventors

• Lee Sang Yool
• Hong Joo Hee
• Park Se Jung
• Kim Sang Hwan
• Kim Jang Soon

Classifications

• C08J5/18 Primary

  Manufacture of films or sheets · CPC title

• C09D175/04

  Polyurethanes · CPC title

• C08J2475/04

  Polyurethanes · CPC title

• C08L75/04 Primary

  Polyurethanes · CPC title

• C08J2375/04

  Polyurethanes · CPC title