| 摘要 |
PURPOSE:To improve the adhesive property of the title film to a cooling roll, the flatness and the appearance of the same, by a method wherein, the film is nipped and cooled by the cooling roll, prepared in a temperature within a specified range, and a rubber roll provided with a specified rubber hardness. CONSTITUTION:The molten composition of heat resistant resin, whose glass transition tmeperature is 100 deg.C or higher, is extruded through the slit type die, such as T die or the like, then, is pulled down and cooled by a device constituted of a metallic roll and a rubber roll, which are pressed with each other. The temperature of the metallic roll is Tg-50-Tg-10 based on the glass transition temperature Tg of the composition. When the temperature is up to Tg-50, the adhesion of the title film to the metallic roll becomes ununiform and when the temperature exceeds Tg-10, cloudiness is generated some times. The hardness of the rubber roll achieves a certain effective adhesive property when it is 40-70 deg.C in rubber hardness Shore A while the hardness up to 40 degree is too soft and is not effective in actual use but when the hardness exceeds 7 deg.C, it is hard to absorb mechanical fluctuation and unevenness in thickness, wrinkles or the like may be generated readily. |
