| 摘要 |
Provided is a method for producing, with high productivity, a microporous plastic film having excellent physical properties and mechanical properties by preventing slippage even in wet roller drawing. This method for producing a microporous plastic film is a method for producing a uniaxially or biaxially drawn microporous plastic film by kneading a diluent and a polyolefin polymer with an extruder, discharging the diluent-kneaded polymer from a die in a sheet form, cooling and solidifying the sheet discharged from the die on a drum, then reheating the solidified sheet, drawing the same in a sheet transporting direction with a plurality of rollers, cooling the sheet drawn in the sheet transporting direction, then gripping both ends of the sheet with clips, introducing the sheet into a tenter, and then cleaning the diluent, wherein: in drawing the sheet in the transporting direction, the sheet is drawn at the greatest ratio between the furthest-downstream roller (B) in the transporting direction among said plurality of rollers, and a roller (A) that is driven by a motor and located next to said roller (B) on the upstream side in the transporting direction; and the ratio of the traveling speed of the clip, in said tenter, located on the furthest upstream side in the transporting direction to the circumferential speed of said roller (B) is set within the range of from -3% to +3%. |
