HIGH-EFFICIENCY PLASMA TREATMENT OF PAPER

摘要

PROBLEM TO BE SOLVED: To provide a process for the treatment of a paper web for getting a proper surface characteristic to improve the adhesivity of a photosensitive film-forming material and/or an ordinarily coated layer and provide a treating apparatus therefor. SOLUTION: A web is passed through a high-voltage sheath region of a plasma generated by an electrode placed in a discharge zone and supplied with electric power or in a dark space. The frequency of the driving voltage should be higher than a lower limit varying with the properties of paper substrate and plasma and lower than a higher limit to cause a remarkable drop of the sheath voltage. The diminishment of the merit of approach is observable out of the above range. The dark zone is generated by the treating electrode of the treating zone. The treating zone contains a counter electrode having a surface area larger than that of the treating electrode. The apparatus is provided with a power source to drive the treating electrode with an oscillating high voltage having a frequency lower than 2 MHz or thereabout and higher than 1/tc wherein tc is the charging time of the web surface exposed to the rms ion current in the plasma.