Thermoplastic Polyurethane Film and Preparation Method Thereof

Patent metadata

Field	Value
Publication number	US-2020010677-A1
Application number	US-201816494558-A
Country	US
Kind code	A1
Filing date	Mar 27, 2018
Priority date	Mar 27, 2017
Publication date	Jan 9, 2020
Grant date	—

Abstract

A thermoplastic polyurethane film including a cured product of a polyurethane resin compositon is provided. The polyurethane resin compostion 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

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.

2 . The thermoplastic polyurethane film of claim 1 , 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.

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

4 . 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.

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

6 . The thermoplastic polyurethane film of claim 4 , wherein a content of the chain extender is 5 wt % to 15 wt % based on a weight of the mixture.

7 . The thermoplastic polyurethane film of claim 4 , wherein a content of the second isocyanate-based curing agent is 20 wt % to 37.5 wt % based on a weight of the mixture.

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

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

10 . 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.

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

12 . The method of claim 10 , wherein the additional curing is carried out at a temperature of 40° C. to 80° C. for 12 hours to 48 hours.

13 . The method of claim 10 , 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.

14 . The method of claim 13 , 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

• C08J2475/04

  Polyurethanes · CPC title

• C08J2367/02

  Polyesters derived from dicarboxylic acids and dihydroxy compounds; (C08J2367/06 takes precedence) · CPC title

• C08L75/04 Primary

  Polyurethanes · CPC title

• C08J5/18 Primary

  Manufacture of films or sheets · CPC title

• C08J2375/04

  Polyurethanes · CPC title