| 摘要 |
PURPOSE:To improve the workability in an evacuation operation and to improve the adhesive property of a positive or negative film by incorporating particles having an average particle size and refractive index of prescribed values into the above film. CONSTITUTION:The light transparent film is preferably the film formed by applying a polymer soln. contg. the prescribed particles on the surface of a transparent plastic film, for example, transparent plastic film consisting of polyethylene terephthalate, etc., or the film formed by applying the polymer soln. contg. the prescribed particles directly on an image forming material to form a coating layer. Particularly, the former film is more preferable in terms of the evacuation operation efficiency, the stability of the resulted light transparent film, the workability, the ease of production, etc. The average particle size measured by coalter counter method is required to be 4 to 9mu and the refractive index of the particles is required to be 1.40 to 1.70, more preferably 1.40 to 1.60. The time required for the vacuum adhesion of the positive or negative film is shortened in this way and the workability of the printing plate is improved. |
