Method for manufacturing polarizing film using ultrasonic vibrator for atomizing coating solution
Disclosed herein are a polarizing film manufacturing method including (a) injecting a coating solution containing a component functioning as a polarizer into a sealed chamber to form an injection condition of the coating solution, (b) supplying a polyvinyl alcohol film into the chamber and dyeing outer surfaces of the polyvinyl alcohol film with the coating solution, and (c) discharging the polyvinyl alcohol film dyed with the coating solution out of the chamber, a polarizing film manufacturing apparatus, and a polarizing film exhibiting improved optical properties manufactured using the same.
1. A polarizing film manufacturing method comprising:
(a) injecting a coating solution into a sealed chamber by atomizing the coating solution using an ultrasonic vibrator and carrying the atomized coating solution into the chamber using a carrier gas, the coating solution including a component functioning as a polarizer, wherein process (a) comprises injecting the coating solution using an ultrasonic injection method or an ultrasonic spray injection method;
(b) supplying a polyvinyl alcohol film into the chamber and dyeing outer surfaces of the polyvinyl alcohol film with the atomized coating solution in the chamber; and
(c) discharging the polyvinyl alcohol film dyed with the coating solution out of the chamber,
wherein the coating solution is injected while an ultrasonic wave of 10 Hz to 100 Hz is applied to the coating solution.
2. The polarizing film manufacturing method according to claim 1 , wherein the coating solution containing the component functioning as the polarizer is an aqueous solution containing iodine.
3. The polarizing film manufacturing method according to claim 1 , wherein the coating solution injected into the chamber has a concentration of 10 −5 mole/liter to 10 −1 mole/liter.
4. The polarizing film manufacturing method according to claim 1 , wherein the polyvinyl alcohol film is moved in the chamber and out of the chamber by rotary rolls.
5. The polarizing film manufacturing method according to claim 4 , wherein two or more of the rotary rolls simultaneously contact an upper surface and a lower surface of the polyvinyl alcohol film.
6. The polarizing film manufacturing method according to claim 1 , wherein the polyvinyl alcohol film is dyed with the coating solution while being moved in the chamber at a speed of 0.5 m/min to 40 m/min.
7. The polarizing film manufacturing method according to claim 1 , wherein the polyvinyl alcohol film is moved in the chamber along one or more selected from a group consisting of a linear movement route, a V-shaped movement route, and a U-shaped movement route.
8. The polarizing film manufacturing method according to claim 1 , wherein the coating solution is injected in a direction identical to or opposite to an advancing direction of the polyvinyl alcohol film.
9. The polarizing film manufacturing method according to claim 1 , further comprising elongating the polyvinyl alcohol film dyed with the coating solution.
10. The polarizing film manufacturing method according to claim 9 , wherein the elongating process comprises elongating the polyvinyl alcohol film at a elongating ratio of 1.5 to 6.
11. A polarizing film manufactured using a polarizing film manufacturing method according to claim 1 .
12. The polarizing film according to claim 11 , wherein the polarizing film has a degree of polarization of 99.95% or higher.
13. A polarizing sheet manufactured by attaching protective films to an upper surface and a lower surface of a polarizing film according to claim 11 .
14. The polarizing sheet according to claim 13 , wherein each of the protective films is a triacetyl cellulose film.