Method for manufacturing high-transmittance optical filter for image display devices

1. A method for manufacturing a high-transmittance optical filter for image display devices, comprising the steps of:

coating a photocatalytic compound on a transparent substrate to form a photocatalytic film (a first step);

selectively exposing the photocatalytic film to light to form a pattern and growing at least one metal crystal thereon by plating to form a metal pattern (a second step); and

selectively etching and removing the photocatalytic compound remaining on the transparent substrate using a buffered oxide etchant (BOE) (a third step).

2. The method according to claim 1 , wherein the transparent substrate is a glass substrate or a transparent plastic substrate selected from the group consisting of acrylic resins, polyesters, polycarbonates, polyethylenes, polyethersulfones, olefin-maleimide copolymers, and norbomene-based resins.

3. The method according to claim 1 , wherein the photocatalytic compound used in the first step is a Ti-containing organic compound.

4. The method according to claim 3 , further comprising the step of forming a photosensitizer-containing water-soluble polymer layer on the photocatalytic film.

5. The method according to claim 4 , wherein the water-soluble polymer layer is formed of a material selected from the group consisting of polyvinylalcohols, polyvinylphenols, polyvinylpyrrolidones, polyacrylic acids, polyacrylamides, gelatins, and copolymers thereof.

6. The method according to claim 4 , wherein the photosensitizer is at least one compound selected from the group consisting of tar colorants, potassium and sodium salts of chlorophylline, riboflavin and derivatives thereof, water-soluble annatto, CuSO 4 , caramel, curcumine, cochinal, citric acid, ammonium citrate, sodium citrate, oxalic acid, potassium tartarate, sodium tartarate, ascorbic acid, formic acid, triethanolamine, monoethanolamine, and malic acid.

7. The method according to claim 4 , further comprising the step of treating the selectively exposed photocatalytic film with a metal salt solution to deposit metal particles in the pattern and to remove the water-soluble polymer layer before growing a metal crystal in the second step.

8. The method according to claim 7 , wherein the metal salt solution is an Ag salt solution, a Pd salt solution, or a mixed solution thereof.

9. The method according to claim 3 , further comprising the step of treating the selectively exposed photocatalytic film with a metal salt solution to deposit metal particles in the pattern before growing a metal crystal in the second step.

10. The method according to claim 9 , wherein the metal salt solution is an Ag salt solution, a Pd salt solution, or a mixed solution thereof.

11. The method according to claim 1 , wherein the metal pattern is formed by growing two or more metal crystals by plating in the second step.

12. The method according to claim 1 , wherein the plating is performed using a plating metal selected from the group consisting of Ni, Cu, Ag, Au and alloys thereof by electroless or electro-plating in the second step.

13. The method according to claim 1 , wherein the concentration of the BOE is in the range of 0.015% to 5%.

14. The method according to claim 1 , wherein the treatment temperature with BOE is in the range of 25° C. to 40° C.

15. The method according to claim 1 , wherein the treatment time with BOE is in the range of 5 seconds to 5 minutes.

16. A high-transmittance optical filter for image display devices manufactured by the method according to claim 1 .

17. An image display device comprising the optical filter according to claim 16 .