Method for producing transparent conducting film
Provided is a transparent conducting film having a favorable optical property, favorable electrical property, and almost no in-plane resistance anisotropy. A method for producing a transparent conducting film provided with a conducting layer containing a metal nanowire and a binder resin, comprises steps of: preparing a coating liquid containing the metal nanowire and the binder resin, and coating the coating liquid on one main face of a transparent substrate, wherein, in the coating step, a bar-coat printing method is performed using a bar provided with a groove having a pitch (P) and a depth (H) which satisfy a ratio P/H of 5 to 30.
1. A method for producing a transparent conducting film provided with a conducting layer containing metal nanowires and a binder resin, comprising steps of:
preparing a coating liquid containing the metal nanowire and the binder resin, and
coating the coating liquid on one main face of a transparent substrate,
wherein, in the coating step, a bar-coat printing method is performed using a bar provided with a groove having a pitch (P) and a depth (H) which satisfy a ratio P/H of 5 to 30, and
wherein a ratio (R TD /R MD ) of a resistance value of the conducting layer in a direction perpendicular to an in-plane coating direction of the coating liquid (R TD ) to a resistance value of the conducting layer in the in-plane coating direction of the coating liquid (R MD ) is 0.93 to 1.59.
2. The method for producing a transparent conducting film according to claim 1 , wherein a material forming a surface of the bar has a friction coefficient of 0.05 to 0.45.
3. The method for producing a transparent conducting film according to claim 2 , wherein, when the coating liquid is coated on one main face of the transparent substrate, a relative moving velocity (coating velocity) V (mm/sec) of the transparent substrate relative to the bar satisfies 2000≥V≥350.
4. The method for producing a transparent conducting film according claim 3 , wherein when the groove formed on the bar has a pitch (P) and a depth (H), a ratio P/H is 9 to 30.
5. The method for producing a transparent conducting film according to claim 2 , wherein when the groove formed on the bar has a pitch (P) and a depth (H), a ratio P/H is 9 to 30.
6. The method for producing a transparent conducting film according to claim 1 , wherein a material forming a surface of the bar has a friction coefficient of 0.05 to 0.40.
7. The method for producing a transparent conducting film according to claim 6 , wherein, when the coating liquid is coated on one main face of the transparent substrate, a relative moving velocity (coating velocity) V (mm/sec) of the transparent substrate relative to the bar satisfies 2000≥V≥50.
8. The method for producing a transparent conducting film according to claim 7 , wherein when the groove formed on the bar has a pitch (P) and a depth (H), a ratio P/H is 9 to 30.
9. The method for producing a transparent conducting film according to claim 6 , wherein when the groove formed on the bar has a pitch (P) and a depth (H), a ratio P/H is 9 to 30.
10. The method for producing a transparent conducting film according to claim 1 , wherein when the groove formed on the bar has a pitch (P) and a depth (H), a ratio P/H is 9 to 30.
11. The method for producing a transparent conducting film according to claim 1 , wherein the metal nanowires have an average length of 1 to 100 μm and an average diameter of 1 to 500 nm.
12. The method for producing a transparent conducting film according to claim 1 , wherein the coating liquid has a viscosity in a range of 1 to 50 mPa·s.
13. The method for producing a transparent conducting film according to claim 1 , wherein the metal nanowire has an average diameter size of 5 to 100 nm, an average major axis length of 2 to 70 μm, and an average aspect ratio 100 or more.