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 pores;
a second step of carrying out pore diameter enlargement treatment to the pores;
a third step of carrying out anodic oxidation after the second step; and
a fourth step of repeating the second and third steps alternately.
2. The method of manufacturing a mold composed of anodic oxidized porous alumina according to claim 1 , wherein the fourth step is finished at the pore diameter enlargement treatment of the second step.
3. The method of manufacturing a mold composed of anodic oxidized porous alumina according to claim 1 , wherein anodic oxidation is carried out with oxalic acid as an electrolyte and at a formation voltage of 30 to 60 V.
4. The method of manufacturing a mold composed of anodic oxidized porous alumina according to claim 1 , wherein the anodic oxidation is carried out with sulfuric acid as an electrolyte and at a formation voltage of 20 to 30 V.
5. A mold composed of anodic oxidized porous alumina manufactured by the method according to claim 1 .
6. The mold composed of anodic oxidized porous alumina according to claim 5 , wherein the mold has a pore period of 50 to 600 nm and a pore depth of 100 nm or more.
7. 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 5 .
8. An anti-reflective film having a refractive index continuously changed and then reducing reflectance produced with the mold according to claim 5 .
9. The method of manufacturing a mold composed of anodic oxidized porous alumina according to claim 3 , wherein anodic oxidation of the each step is carried out at about the same formation voltage.
10. The method of manufacturing a mold composed of anodic oxidized porous alumina according to claim 4 , wherein the anodic oxidation is carried out with sulfuric acid as an electrolyte and at about the same formation voltage.
11. The method of manufacturing a mold composed of anodic oxidized porous alumina according to claim 1 , wherein the second step is carried out 2 or more times in the fourth step.
12. The method of manufacturing a mold composed of anodic oxidized porous alumina according to claim 11 , wherein the second step is carried out 4 or more times in the fourth step.
13. The method of manufacturing a mold composed of anodic oxidized porous alumina according to claim 1 , wherein the second step is carried out 2 to 5 times in the fourth step.