Slit die, and method and device for producing base material with coating film

A slit die, comprising a first lip and a second lip, wherein said first lip and said second lip are integrated by a lip fastening element in a state that an inner face of said first lip and an inner face of said second lip are faced each other;

• partial portions of the inner faces facing each other are positioned with a gap to form a liquid feed passage and a lip gap extending in the longitudinal direction of said lips;
• the lower end of said lip gap forms a discharge opening toward outside;
• both the ends in the longitudinal direction of said lip gap are closed from outside;
• and the top end of said lip gap communicates with said liquid feed passage, wherein
• (a) said first lip comprises a first block and a second block,
• (b) a block engaging element is provided for keeping said first block and said second block engaged with each other in such a manner that the relative position between said first block and said second block can be adjusted in the direction perpendicular to the face forming said lip gap, of said first lip,
• (c) a block fastening element is provided for fastening and integrating said first block and said second block after said relative position has been adjusted,
• (d) at least one positioning element is provided to decide said relative position between said first block and said second block, wherein said positioning element comprises a positioning block having a position deciding face which is kept in contact with the outer face of said first block on the side opposite to said inner face of said first lip and/or the outer face of said second block on the side opposite to said inner face of said first lip, and wherein in the case where there is a gap between said positioning block and the outer face of said first block or the outer face of said second block, a positioning decision assisting means is provided between said positioning block and the outer face of said first block or the outer face of said second block through said gap,
• (e) a positioning element fixing element is provided for fixing said positioning element to said first lip, and
• (f) said positioning element and said positioning element fixing element allow the gap width distribution of said lip gap in the longitudinal direction to be adjusted.