Polarizing film and display device including the polarizing film
A polarizing film including a melt-elongated film including a polyolefin and a dichroic dye represented by Chemical Formula 1: wherein in Chemical Formula 1, each group and variable is the same as defined in the detailed description.
1. A polarizing film comprising:
a melt-elongated film comprising
a polyolefin and
a dichroic dye represented by Chemical Formula 1:
wherein, in Chemical Formula 1,
X is a substituted or unsubstituted C3 to C20 alkyl group or a substituted or unsubstituted C3 to C20 alkoxy group, which is attached at position 6 or 7 of a terminal naphthalene group,
R a is a halogen, a substituted or unsubstituted C1 to C5 alkyl group, or a substituted or unsubstituted C1 to C5 alkoxy group,
R b to R d are hydrogen, a halogen, a substituted or unsubstituted C1 to C5 alkyl group, or a substituted or unsubstituted C1 to C5 alkoxy group,
p is an integer of 1 to 3,
q, r, and s are each independently an integer of 0 to 3,
R 1 and R 2 are each independently hydrogen or a substituted or unsubstituted C1 to C10 alkyl group, which are optionally linked to each other to form a ring, and
a first azo group is attached at position 1, 2, or 3 of the terminal naphthalene group.
2. The polarizing film of claim 1 , wherein X is a substituted or unsubstituted C8 to C20 alkyl group or a substituted or unsubstituted C8 to C20 alkoxy group.
3. The polarizing film of claim 1 , wherein X is attached at position 6 of the terminal naphthalene group, and wherein the first azo group is attached at position 2 of the terminal naphthalene group.
4. The polarizing film of claim 1 , wherein X is attached at position 7 of the terminal naphthalene group, and wherein the first azo group is attached at position 3 of the terminal naphthalene group.
5. The polarizing film of claim 1 , wherein the dichroic dye has an aspect ratio of about 2.5 to about 5.
6. The polarizing film of claim 1 , wherein a solubility parameter difference between the polyolefin and the dichroic dye ranges from about 7.4 to about 10.
7. The polarizing film of claim 1 , wherein the dichroic dye has a decomposition temperature of greater than or equal to about 245° C.
8. The polarizing film of claim 1 , wherein the polyolefin has a melting point of less than or equal to about 300° C.
9. The polarizing film of claim 1 , wherein the polyolefin comprises polyethylene, polypropylene, a copolymer thereof, or a combination thereof.
10. The polarizing film of claim 1 , wherein the polyolefin has a melt flow index of about 1 gram per 10 minutes to about 15 grams to 10 minutes.
11. The polarizing film of claim 1 , wherein polypropylene has a melt flow index of about 0.1 grams per 10 minutes to about 5 grams per 10 minutes, and
the polyethylene-polypropylene copolymer has a melt flow index of about 5 grams per 10 minutes to 15 grams per 10 minutes.
12. The polarizing film of claim 1 , wherein the polyolefin is a mixture of polypropylene and a copolymer of polyethylene and polypropylene, and wherein a content of polyethylene in the copolymer of polyethylene and polypropylene is about 1 to about 50 percent by weight.
13. The polarizing film of claim 12 , wherein a weight ratio of polypropylene and the copolymer of polyethylene and polypropylene in the polyolefin is about 1:9 to about 9:1.
14. The polarizing film of claim 1 , wherein an amount of the dichroic dye in the polarizing film is about 0.01 to about 5 parts by weight based on 100 parts by weight of the polyolefin.
15. The polarizing film of claim 1 , wherein the polarizing film has a dichroic ratio of about 3 to about 10 in a wavelength region of greater than or equal to about 600 nanometers.
16. The polarizing film of claim 1 , wherein the dichroic dye is dispersed in the polyolefin, and the polyolefin is elongated in a uniaxial direction by about 400 to about 1,000%.
17. A display device comprising the polarizing film of claim 1 .
18. A composition for a polarizing film, comprising:
a polyolefin and
a dichroic dye represented by Chemical Formula 1:
wherein, in Chemical Formula 1,
X is a substituted or unsubstituted C3 to C20 alkyl group or a substituted or unsubstituted C3 to C20 alkoxy group, which is attached at position 6 or 7 of a terminal naphthalene group,
R a is a halogen, a substituted or unsubstituted C1 to C5 alkyl group, or a substituted or unsubstituted C1 to C5 alkoxy group,
R b to R d are hydrogen, a halogen, a substituted or unsubstituted C1 to C5 alkyl group, or a substituted or unsubstituted C1 to C5 alkoxy group,
p is an integer of 1 to 3,
q, r, and s are each independently an integer of 0 to 3,
R 1 and R 2 are each independently hydrogen or a substituted or unsubstituted C1 to C10 alkyl group, which are optionally linked to each other to form a ring, and
a first azo group is attached at position 1, 2, or 3 of the terminal naphthalene group.
19. The composition for a polarizing film of claim 18 , wherein X is a substituted or unsubstituted C8 to C20 alkyl group or a substituted or unsubstituted C8 to C20 alkoxy group.
20. The composition for a polarizing film of claim 18 , wherein X is attached at position 6 of the terminal naphthalene group, and wherein the first azo group is attached at position 2 of the terminal naphthalene group.
21. The composition for a polarizing film of claim 18 , wherein X is attached at position 7 of the terminal naphthalene group, and wherein the first azo group is attached at position 3 of the terminal naphthalene group.
22. The composition for a polarizing film of claim 18 , wherein the dichroic dye has an aspect ratio of about 2.5 to about 5.
23. The composition for a polarizing film of claim 18 , wherein a solubility parameter difference between the polyolefin and the dichroic dye ranges from about 7.4 to about 10.
24. The composition for a polarizing film of claim 18 , having a solid content of greater than or equal to about 90 percent by weight.
25. The composition for a polarizing film of claim 18 , which does not comprise a solvent.