Patent ID: 8178166

Claim:
A method for producing a film product including at least one dried coating layer by applying a coating solution on a web using a slot die coater and drying the applied coating solution, said slot die coater including a die with a slot, which has a slot discharging mouth for discharging said coating solution, said method comprising: feeding said web continuously while supporting said web on a back-up roller; discharging said coating solution from said slot discharging mouth disposed close to said web, for forming a bead of said coating solution between said slot discharging mouth and said web; and reducing pressure around said bead of said coating solution in an upstream side of a feeding direction of said web from said bead of said coating solution; wherein said slot discharging mouth is formed between a first lip and a second lip, said first lip being disposed downstream from said second lip in a feeding direction of said web, an end of said first lip having a first lip land which is flat and confronted to said web, and an end of said second lip having a second lip land which is flat and confronted to said web said first lip land satisfying a condition, 30 μm≦ L 1 ≦60 μm wherein L 1 is an average length of the first lip land in said feeding direction, wherein the length L 1 of said first lip land is smaller than a length of said second lip land, wherein at least said first lip is formed of hard alloy in which carbide crystal is contained, wherein a first length defined by a first gap G 1 between said first lip land and said web is smaller than a second length defined by a second gap G 2 between said second lip land and said web, and wherein a length difference LO 1 between said first length defined by said first gap and said second length defined by said second gap G 2 satisfies 30 μm≦LO 1 ≦120 μm.