Anti-reflective film and production method thereof, and stamper for producing anti-reflective film and production method thereof
View Patent ↗In this method for producing an anti-reflective film, pores are formed on a surface of a polymer molding material to continuously change a refractive index and then reduce reflectance, in which anodic oxidized porous alumina, in which pores having a tapered shape and whose pore diameter continuously changes, are formed by repeating anodic oxidation at about the same formation voltage and pore diameter enlargement treatment, is used as a mold, or a stamper, which is produced by using the anodic oxidized porous aluminum as a mold, is used as a mold.
1. A method of manufacturing a mold composed of anodic oxidized porous alumina, comprising:
a first step of carrying out anodic oxidation to an aluminum substrate to form an alumina layer;
a second step of removing the alumina layer;
a third step of carrying out anodic oxidation to the aluminum substrate to form pores after the second step; and
a fourth step of carrying out pore diameter enlargement treatment to the pores.
2. The method of manufacturing a mold composed of anodic oxidized porous alumina according to claim 1 , further comprising:
a fifth step of carrying out anodic oxidation after the fourth step; and
a sixth step of repeating the fourth and fifth steps alternately.
3. The method of manufacturing a mold composed of anodic oxidized porous alumina according to claim 1 , wherein the anodic oxidation of the first step and the third step are carried out at about the same formation voltage.
4. The method of manufacturing a mold composed of anodic oxidized porous alumina according to claim 2 , wherein the anodic oxidation of the first step, the third step, and the fifth step are carried out at about the same formation voltage.
5. The method of manufacturing a mold composed of anodic oxidized porous alumina according to claim 1 , wherein anodic oxidation of the first step and the third step is carried out with oxalic acid as an electrolyte and at a formation voltage of 30 to 60 V.
6. The method of manufacturing a mold composed of anodic oxidized porous alumina according to claim 1 , wherein the anodic oxidation of the first step and the third step is carried out with sulfuric acid as an electrolyte and at a formation voltage of 20 to 30 V.
7. A mold composed of anodic oxidized porous alumina manufactured by the method according to claim 1 .
8. The mold composed of anodic oxidized porous alumina according to claim 7 , wherein the mold has a pore period of 50 to 600 nm and a pore depth of 100 nm or more.
9. A method for producing an anti-reflective film having a refractive index continuously changed and then reducing reflectance, comprising:
forming unevenness on a surface of a polymer molding material by molding shape with the mold according to claim 7 .
10. An anti-reflective film having a refractive index continuously changed and then reducing reflectance produced with the mold according to claim 7 .
11. The method of manufacturing a mold composed of anodic oxidized porous alumina according to claim 1 , wherein the alumina layer formed in the first step is completely removed in the second step.
12. The method of manufacturing a mold composed of anodic oxidized porous alumina according to claim 2 , wherein the sixth step is finished at the pore diameter enlargement treatment.
13. The method of manufacturing a mold composed of anodic oxidized porous alumina according to claim 11 , wherein the anodic oxidation of the first step and the third step are carried out at about the same formation voltage.
14. The method of manufacturing a mold composed of anodic oxidized porous alumina according to claim 2 , wherein the anodic oxidation of the first step, the third step and the fifth step is carried out with oxalic acid as an electrolyte and at a formation voltage of 30 to 60 V.
15. The method of manufacturing a mold composed of anodic oxidized porous alumina according to claim 14 , wherein the anodic oxidation of the first step, the third step, and the fifth step is carried out at about the same formation voltage.
16. The method of manufacturing a mold composed of anodic oxidized porous alumina according to claim 6 , wherein the anodic oxidation of the first step and the third step are carried out at about the same formation voltage.
17. The method of manufacturing a mold composed of anodic oxidized porous alumina according to claim 2 , wherein the anodic oxidation of the first step, the third step and the fifth step is carried out with sulfuric acid as an electrolyte and at a formation voltage of 20 to 30 V.
18. The method of manufacturing a mold composed of anodic oxidized porous alumina according to claim 17 , wherein the anodic oxidation of the first step, the third step, and the fifth step is carried out at about the same formation voltage.