| 摘要 |
PURPOSE:To contrive prevention of dripping of an ink and penetration of bubbles, by a method wherein a nozzle hole side surface and inner walls of nozzle holes of an ink jet head molded from a resin are treated to be hydrophilic, and a water-repellent film is provided on the nozzle hole side surface. CONSTITUTION:An acid treatment of a resin head 10 is conducted by, for example, immersing it in a standard liquid consisting of a mixed liquid containing bichromic acid for 5-15min, followed by washing with water. In this case, the inner walls 12 of the nozzle holes 11 and the nozzle hole side surface 13 are treated to be hydrophilic. The surfaces thus treated are rughened surfaces which are covered by polar groups such as carbonyl groups. When the water- repellent film 14 provided on the nozzle hole side surface thus treated, the surface are a roughened surface provided with the polar groups, so that adhesion of the water-repellent film is enhanced. |
