Polyamide resin film and resin laminate using the same

Patent metadata

Field	Value
Publication number	US-12466951-B2
Application number	US-201916972389-A
Country	US
Kind code	B2
Filing date	Dec 26, 2019
Priority date	Feb 1, 2019
Publication date	Nov 11, 2025
Grant date	Nov 11, 2025

Abstract

The present invention relates to a polyamide resin film having improved light resistance by minimizing color difference variation rate due to long-term ultraviolet irradiation, and a resin laminate using the same.

First claim

The invention claimed is:

1 . A polyamide resin film in which a color difference variation rate (Eab 1 ) value on the 1st day (n=1) of ultraviolet irradiation according to the following Mathematical Formula 1 is 2.5 or less:
Eab n ={( L n −L n−1 ) 2 +( a n −a n−1 ) 2 +( b n −b n−1 ) 2 } 1/2   [Mathematical Formula 1]
wherein, L n−1 is a lightness index of the polyamide resin film on the (n−1)th day of ultraviolet irradiation, a n−1 and b n−1 are color coordinates of the polyamide resin film on the (n−1)th day of ultraviolet irradiation, L n is a lightness index of the polyamide resin film on the n-th day of ultraviolet irradiation, and a n and b n are color coordinates of the polyamide resin film on the n-th day of ultraviolet irradiation, wherein a haze measured according to ASTM D1003 for a specimen having a thickness of 45 μm or more and 55 μm or less is 1.5% or less, wherein the polyamide resin film includes a polyamide resin containing aromatic amide repeating units derived from a combination of an aromatic diacyl compound and an aromatic diamine compound; and an ultraviolet light stabilizer, wherein the ultraviolet light stabilizer includes one or more compounds selected from the group consisting of a triazine-based UV absorber, a triazole-based UV absorber, and a HALS-based UV absorber, wherein the polyamide resin includes a first polyamide segment containing a repeating unit represented by Chemical Formula 1, or a block comprised thereof:

in the Chemical Formula 1, Ar 1 is a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 20 carbon atoms,
wherein the polyamide resin further includes a second polyamide segment containing a repeating unit represented by Chemical Formula 2, or a block comprised thereof:

in the Chemical Formula 2,
Ar 2 is a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 20 carbon atoms,
wherein the first polyamide segment and the second polyamide segment form a backbone chain including an alternating repeating unit represented by Chemical Formula 3:

in the Chemical Formula 3,
A is the first polyamide segment, and
B is the second polyamide segment, and
wherein based on the total repeating units contained in the polyamide resin, a content of the repeating unit represented by Chemical Formula 1 is 80 mol % to 85 mol %, and a content of the repeating unit represented by Chemical Formula 2 is 15 mol % to 20 mol %.

2 . The polyamide resin film of claim 1 , wherein
a lightness index L 1 of the polyamide resin film on the 1 st day of ultraviolet irradiation is at least 93.

3 . The polyamide resin film of claim 1 , wherein
a color coordinate a 1 of the polyamide resin film on the 1 st day of ultraviolet irradiation is −1.5 or more, and b 1 is 4 or less.

4 . The polyamide resin film of claim 1 , wherein
the color difference variation rate (Eab 5 ) value on the 5th day (n=5) of ultraviolet irradiation according to the Mathematical Formula 1 is 0.2 or less.

5 . The polyamide resin film of claim 1 , wherein
the color difference variation rate (Eab 1 ) value on the 1 st day (n=1) of ultraviolet irradiation according to the Mathematical Formula 1 is 20 times or less the color difference variation rate (Eab 10 ) value on the 10th day (n=10) of ultraviolet irradiation according to the Mathematical Formula 1.

6 . The polyamide resin film of claim 1 , wherein
after irradiating the polyamide resin film with ultraviolet rays for 1 day, a yellowness index measured according to ASTM E313 is 7 or less.

7 . The polyamide resin film of claim 1 , wherein
a difference between a yellowness index measured according to ASTM E313 after irradiating the polyamide resin film with ultraviolet rays for 10 days, and a yellowness index measured according to ASTM E313 after irradiating the polyamide resin film with ultraviolet rays for 1 day, is 2.5 or less.

8 . The polyamide resin film of claim 1 , wherein
the polyamide resin film has a retardation (Rth) value in the thickness direction at a wavelength of 550 nm of −8000 nm or more and −3000 nm or less, and a moisture absorption rate according to the following Mathematical Formula 2 is 0.5% or more and 7.0% or less:
Moisture Absorption Rate (%)=( W 1− W 2)*100/ W 2  [Mathematical Formula 2]

wherein in the Mathematical Formula 2, W1 is a weight measured by impregnating the polyamide resin film in ultrapure water for 24 hours, and W2 is a weight measured by drying the polyamide resin film at 150° C. for 30 minutes after the impregnation.

9 . The polyamide resin film of claim 1 , wherein
the polyamide resin film has a retardation (Rth) value in the thickness direction at a wavelength of 550 nm of −6000 nm or more and −3000 nm or less.

10 . The polyamide resin film of claim 1 , wherein
the first polyamide segment has a number average molecular weight of 100 g/mol or more and 5000 g/mol or less.

11 . The polyamide resin film of claim 1 , wherein
the alternating repeating unit represented by Chemical Formula 3 is a repeating unit represented by Chemical Formula 4:

in the Chemical Formula 4,
Ar 1 and Ar 2 are each independently a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 20 carbon atoms,
a1 and a2 are each independently an integer of 1 to 10, and
b1 and b2 are each independently an integer of 1 to 5.

12 . The polyamide resin film of claim 1 , wherein
the triazole-based UV absorber includes a compound represented by Chemical Formula 11:

in the Chemical Formula 11,
R 1 and R 2 are each independently hydrogen or an alkyl group having 1 to 20 carbon atoms.

13 . A resin laminate comprising:
a substrate including the polyamide resin film of claim 1 ; and a hard coating layer formed on at least one side of the substrate.

Assignees

• Lg Chemical Ltd

Inventors

• Choi Il Hwan
• Park Soonyong
• Tae Young Ji
• Park Youngseok
• Ryu Bi Oh

Classifications

• B32B2307/412

  Transparent · CPC title

• B32B2307/71

  Resistive to light or to UV · CPC title

• B32B2457/20

  Displays, e.g. liquid crystal displays, plasma displays · CPC title

• C08L2203/20

  use in electrical or conductive gadgets · CPC title

• C08K5/3492

  Triazines · CPC title