| 摘要 |
PURPOSE:To form an emulsion-coated layer free from unevenness, by forming the discharging face of a corona electrode into a concave face having a curvature similar to that of a grounding roller or a plane and specifying discharge distance and width of the face when corona discharging against a photographic paper surface subjected to hydrophobicity-enhancing treatment with polyolefin or the like. CONSTITUTION:The hydrophobic surface of a base 3, such as paper made hydrophobic with polyethylene or the like, or a polyethylene terephthalate hydrophobic film is subjected to corona discharge 4 between a grounding roller 1 and a corona electrode 2 to make it hydrophilic. At that time, the discharge face (n) is formed into a concave face having a curvature similar to that of the roller 1 or a plane face, or a face having a medium curvature between that of said concave face and the plane. The width of the face (n) is kept <=20mm., as shown in the figures (b)-(e). The discharge distance between the electrode 2 and the base 3 surface is kept <=1,500mum, thus permitting the surface subjected to discharge immediately (few min) before emulsion coating to obtain a uniformly coated layer free from tire-mark-like unevenness, or the like even under severe discharge conditions. |
