Manufacturing methods for antistatic layers and optical laminates

Abstract

The manufacturing method provided in this application is for manufacturing an anti-static layer for optical laminates. The manufacturing method includes the following steps: applying a coating liquid containing a conductive material, a binder resin, and a solvent to the surface of a substrate to form a coating film; and drying the coating film in a manner satisfying conditions (1) and (2), thereby removing the solvent and forming an anti-static layer. The conductive material is a single-layer carbon nanotube with a length of 3µm or more and less than 300µm. Condition (1): The drying temperature T of the coating film is 50°C or more. Condition (2): The time Z from the application of the coating liquid to the start of drying of the coating film is 0.01 seconds or more and 50 seconds or less. This manufacturing method is suitable for manufacturing an anti-static layer for use in image display devices such as automotive applications in harsh environments.

Claims

1. A method for manufacturing an antistatic layer, which is used to manufacture an antistatic layer for optical laminates, the method comprising the following steps: applying a coating liquid containing a conductive material, a binder resin and a solvent to the surface of a substrate to form a coating film; and drying the coating film in a manner that satisfies the following conditions (1) and (2), thereby removing the solvent and forming the antistatic layer; wherein the conductive material is a single-layer carbon nanotube with a length of 3µm or more and less than 300µm; condition (1): the drying temperature T of the coating film is 50°C or more; condition (2): the time Z from the application of the coating liquid to the start of drying of the coating film is 0.01 seconds or more and 50 seconds or less.

2. The manufacturing method of claim 1, wherein the aforementioned coated film is dried in a manner that satisfies the following condition (3) in addition to the aforementioned conditions (1) and (2); Condition (3): The drying time H of the aforementioned coated film is 10 seconds or more and 150 seconds or less.

3. The manufacturing method of claim 1, wherein the aforementioned drying temperature T is below 130°C.

4. The manufacturing method of claim 1, wherein the aforementioned coating liquid substantially does not contain a leveling agent, or the amount of solid components contained in the aforementioned coating liquid is 100 parts by weight and the leveling agent is contained in an amount of 8 parts by weight or less.

5. The manufacturing method of claim 1, wherein the aforementioned coating liquid substantially does not contain a leveling agent, or the amount of solid components contained in the aforementioned coating liquid is 100 parts by weight and the leveling agent is contained in an amount of 8 parts by weight or less; and the aforementioned coating film is dried under the condition of 15 seconds or less for the aforementioned time Z.

6. The manufacturing method of claim 1, wherein the aforementioned coating film with a thickness of 1µm or more and 12µm or less is formed on the surface of the aforementioned substrate.

7. The manufacturing method of claim 1, wherein the aforementioned substrate is an optical thin film.

8. The manufacturing method of claim 1, wherein the aforementioned substrate comprises a polarizing film.

9. The manufacturing method of claim 1, wherein the formation of the aforementioned coating film and the drying of the formed coating film are carried out while conveying the strip-shaped aforementioned substrate.

10. The manufacturing method of claim 1, wherein the aforementioned electrostatic discharge layer is formed having a thickness of 5 nm or more and 200 nm or less.

11. The manufacturing method of claim 1, wherein the aforementioned antistatic layer is formed having a surface resistivity of 1.0 × 10⁹ Ω / □ or less.

12. The manufacturing method of claim 1 is to form the aforementioned antistatic layer that satisfies the following formula (I); wherein A and B in formula (I) are the surface resistivity (unit: Ω / □) of the aforementioned antistatic layer before and after the weather resistance test (test conditions: Z-IN1) specified in German industrial standard DIN75220; -2≦logB-logA≦2 (I).

13. A method for manufacturing an optical laminate, comprising an optical thin film and an anti-static layer sequentially; and the method comprising the step of forming the aforementioned anti-static layer by any one of claims 1 to 12.

14. The manufacturing method of claim 13, wherein the aforementioned substrate is an optical thin film, and the manufacturing method is to form the aforementioned electrostatic anti-electrostatic layer on the aforementioned optical thin film.

15. The manufacturing method of claim 13, wherein the aforementioned optical thin film includes a polarizing thin film.

16. A method for manufacturing an optical laminate, comprising an optical thin film, an anti-static layer and an adhesive sheet in sequence; and the method comprising the step of forming the aforementioned anti-static layer by any one of claims 1 to 12.

17. The manufacturing method of claim 16, wherein the aforementioned substrate is an optical thin film, and the manufacturing method is to form the aforementioned electrostatic anti-electrostatic layer on the aforementioned optical thin film.

18. The manufacturing method of claim 16, wherein the aforementioned optical thin film includes a polarizing thin film.

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