| 摘要 |
PURPOSE:To form a clear image with a low output and at high speed when perforating a stencil paper through using IR rays or a thermal printing head, by adhering a porous base sheet to one side of a thermoplastic resin film monoaxially stretched in the machine direction. CONSTITUTION:Polyethylene, polypropylene, polyamides, polyimides, etc. and copolymers thereof, mixtures thereof and the like can be used as a thermoplastic resin. A film of the thermoplastic resin monoaxially stretched in the machine direction has a degree of heat shrinkage of not less than 10% in the machine direction and not more than 3% in the transverse direction, as measured after immersing the film for 3min in a silicone oil bath heated to a temperature lower than the melting or softening point of the film by at least 20 deg.C and then cooling the film to room temperature. A porous base sheet is a paper made from synthetic fibers such as polyester fibers, vinylon fibers and nylon fibers or natural fibers of Manila hemp, paper mulberry, paper birch or the like, used either singly or in combination, or a nonwoven fabric of synthetic fibers. The monoaxially stretched film and the porous base sheet are adhered to each other by an adhesive or by welding. |
