| 摘要 |
Provided are a multilayer film comprising a plurality of resin layers having melt viscosities at the same heating temperature being different from one another, wherein it is a multilayer resin film which is reduced in the irregularity of the surface thereof; and a method for producing a multilayer resin film which comprises laminating a plurality of resins having melt viscosities at the same heating temperature being different from one another, without the formation of irregulars ties on the surface of the film. A method for producing a multilayer resin film, wherein a plurality of resins having melt viscosities at one heating temperature being different from one another are laminated, by the use of a multi-manifold die, which comprises controlling respective temperatures of an extruder provided connected to a manifold, the manifold, a die adjacent to the manifold, through which the above plural resins are passed, in such a manner that the difference of the melt viscosities of adjacent resin layers is 3000 poise or less at a shear rate of 20 to 500 sec -1 , and then laminating the respective molten resins, to form a multilayer film. |
