| 摘要 |
PURPOSE:To produce a polypropylene resin sheet having a large thickness and excellent high-speed formability and transparency by molding under specified molding conditions a resin composition prepared by blending a specified additive into a polypropylene resin. CONSTITUTION:A resin composition prepared by blending a fatty acid amide lubricant into a polypropylene resin is melted at a temperature of 200 deg.C or above, the molten resin is extruded in a sheet form, which is then rapidly cooled to or below 30 deg.C. The film-shaped material 9 of the resin composition extruded through an extrusion T-die 6 in the molten state is introduced in the flowing- down direction of cooling water 7, 8 flowing down, whereby the film-shaped material 9 is rapidly cooled while being guided by guide rolls 10-13 into cooling water 14 contained in a cooling water tank 5, in which the material 9 is completely cooled, and is then recovered. The cooling water in the tank 5 is controlled to a predetermined temperature by an appropriate temperature-controlling mechanism 15 or the like, and can be used by circulating it to cooling water flow-down tanks 1, 2 by an appropriate pump 16. |
