Polyamide resin film and resin laminate using the same
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.
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.