Polyester film for display

• US 6,921,580 B2
• Filed: 06/10/2003
• Issued: 07/26/2005
• Est. Priority Date: 06/12/2002
• Status: Active Grant

• Current Assignee: Mitsubishi Chemical Corporation (Mitsubishi Chemical Group Corp.)
• Original Assignee: Mitsubishi Polyester Film Corporation (Mitsubishi Chemical Group Corp.)
• Inventors: Shinjo, Kanae, Akatsu, Kazuyuki
• Primary Examiner(s): Chen, Vivian
• Application Number:
  US10/459,049
• Publication Number:
  US 20030235704A1
• Time in Patent Office: 777 Days
• Field of Search: 428/480, 428/910, 359/350, 359/359, 359/361, 359/601
• US Class Current: 428/480
• CPC Class Codes: C08J 2367/02 Polyesters derived from dicarboxylic acids and dihydroxy compounds; C08J2367/06 takes precedence
• CPC Class Codes: C08J 7/0427 with only one layer of a composition containing a polymer binder with more layers C08J7/042
• CPC Class Codes: C08J 7/043 Improving the adhesiveness of the coatings per se, e.g. forming primers adhesives in the form of films or foils characterised by the primer layers between the polymer carriers and the adhesives C09J7/50
• CPC Class Codes: C08J 7/044 Forming conductive coatings; Forming coatings having anti-static properties
• CPC Class Codes: C08J 7/046 Forming abrasion-resistant coatings; Forming surface-hardening coatings
• CPC Class Codes: Y10T 428/31786 Of polyester [e.g., alkyd, etc.]
• CPC Class Codes: Y10T 428/31794 Of cross-linked polyester

Abstract

The present invention relates to a polyester film for display comprising:

a polyester film substrate containing an ultraviolet light absorber; and

a coating layer formed on at least one surface of said polyester film substrate,

said polyester film having a haze of not more than 2.0% and a light transmittance at 380 nm of not more than 5.0%.

Claims

1. A polyester film for display which comprises:

a polyester film substrate containing an ultraviolet light absorber; and

a coating layer formed on at least one surface of said polyester film substrate, said polyester film having a haze of not more than 2.0% and a light transmittance at 380 nm of not more than 5.0%,

and which polyester film has Δ

R of not more than 2.0%, said Δ

R being defined by the formula;

Δ

R=Rs−

Rc(min.)

where Rs is an average value of absolute reflectance values as measured on a surface of the coating layer in a wavelength range of 2,400 to 2,000 nm; and

Rc(min.) is a minimum value of absolute reflectance values as measured on a surface of the coating layer in a wavelength range of 300 to 800 nm.

2. A polyester film for display according to claim 1, wherein the ultraviolet light absorber is a benzoxazinone-based ultraviolet light absorber.

3. A polyester film for display according to claim 1, wherein the polyester film substrate is a laminated film having at least three layers.

4. A polyester film for display according to claim 3, the ultraviolet light absorber is contained in an intermediate layer of the at least three layers of the laminated film.

5. A polyester film for display according to claim 1, having a color tone b* value of not more than 1.5.

6. A polyester film for display according to claim 1, wherein a total amount of oligomers present on front and rear surfaces of the polyester film after the film is heat-treated at 180°

C. for 10 minutes, is not more than 15 mg/m².

7. A polyester film for display according to claim 1, having a total light transmittance of not less than 75%.

8. A polyester film for display according to claim 1, having a shrinkage percentage of not more than 2.0% in each of longitudinal and transverse direction thereof after heat-treated at 100°

C. for 5 minutes.

9. An anti reflective film for display comprising a polyester film which comprises:

a polyester film substrate containing an ultraviolet light absorber; and

a coating layer formed on at least one surface of said polyester film substrate,

said polyester film having a haze of not more than 2.0% and a light transmittance at 380 nm of not more than 5.0%,

and which anti reflective film has Δ

R of not more than 2.0%, said Δ

R being defined by the formula;

Δ

R=Rs−

Rc(min.)

where Rs is an average value of absolute reflectance values as measured on a surface of the coating layer in a wavelength range of 2,400 to 2,000 nm; and

Rc(min.) is a minimum value of absolute reflectance values as measured on a surface of the coating layer in a wavelength range of 300 to 800 nm.

10. An anti reflective film for display according to claim 9, wherein the ultraviolet light absorber is a benzoxazinone-based ultraviolet light absorber.

11. An anti reflective film for display according to claim 9, wherein the polyester film substrate is a laminated film having at least three layers.

12. An anti reflective film for display according to claim 11, the ultraviolet light absorber is contained in an intermediate layer of the at least three layers of the laminated film.

13. An anti reflective film for display according to claim 9, wherein said polyester film has a color tone b* value of not more than 1.5.

14. An anti reflective film for display according to claim 9, wherein a total amount of oligomers present on front and rear surfaces of the polyester film after the film is heat-treated at 180°

C. for 10 minutes, is not more than 15 mg/m².

15. An anti reflective film for display according to claim 9, wherein said polyester film has a total light transmittance of not less than 75%.

16. An anti reflective film for display according to claim 9, wherein said polyester film has a shrinkage percentage of not more than 2.0% in each of longitudinal and transverse direction thereof after heat-treated at 100°

C. for 5 minutes.