| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject product specified in birefringence and crystallinity measured by an X-ray diffraction method and largely improved in heat-resistant dimensional stability on a work giving a heat history to the product in a state that a tension is applied to the product in a flowing direction, such as a printing work. SOLUTION: This non-oriented film comprises a crystalline polypropylene resin and has a birefringence of <=0.006, preferably <=0.005, and a crystallinity of >=35%, preferably 45%, measured by an X-ray diffraction method. The crystalline polypropylene resin preferably has a melting point of >=135 deg.C and a melt flow rate of 0.1-50g/10min. The objective product is preferably obtained e.g. by a method comprising controlling the temperature of cooling rolls used for cooling and solidifying the crystalline polypropylene resin from the melted state. Therein, the temperature of the rolls for first cooling the melted polypropylene resin is preferably controlled to a temperature of 60 deg.C to (Tm-40) deg.C (Tm is the melting point of the resin). The thickness of the film is generally 5-254μm.
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