Fuji Photo Film Company, Limited

Fujifilm Corporation

Yasuhiko Tokimasa

Yoshinobu Katagiri

Akio Tsuji

Kazuhiro Oki

Yasushi Suga

Yoshihisa Noguchi

A die of a coating apparatus for applying a coating solution includes down- and upstream blocks in a feeding direction of a web, which respectively have a first lip and a second lip. A lip land of the first lip is shorter than a lip land of the second lip in the feeding direction so as to satisfy a predetermined condition. In assembling the coating apparatus, bottoms of down- and upstream blocks are fixed to a fixer with bolts. Between the fixer and the downstream block, a plate member is provided such that the first lip land protrudes from the second lip land.

Apparatus and method for applying coating solution, die and method for assembling thereof

The mounting is formed by grinding an integrally molded material with accuracy of the &#x3bc;m order. An upper portion of the mounting is an L-shaped holding portion on which a slot die is positioned. An upper face of the holding portion contacts a lower face of the slot die, and a side face of the holding portion contacts a rear face of the slot die. The lower and rear faces of the slot die and the upper and side faces of the holding portion are formed to have such a straightness for the total length that the unevenness thereof may be in 5 &#x3bc;m. Thus the slot die can be held with high accuracy, and the clearance accuracy between the lips and a web can be increased.

Coating apparatus and coating method

A method to obtain and keep, at the time of actual coating, a uniform charge distribution on a web that is to be subsequently coated in order to establish stable high-speed coating provides a higher resistivity in a web edge area than that in a web central area by applying a subbing layer to the web central area while leaving the edge area free of the subbing layer.

Use of subbing layer in web coating

In curtain coating for multiple layers consisting of lower most layer, uppermost layer and intermediate layer, using coating liquid having viscosity more than 300 mPas for one layer or more of multiple layers improves amazingly the curtain coating stability against disturbance such as passing spliced portion of running web. The one layer or more layers for which coating liquid having viscosity more than 300 mPas is to be used is selected from intermediate layer. The curtain coating stability is further improved by combining the high viscosity coating liquid for intermediate layer with other technologies such as electrifying web, heating web upstream of coating point and/or keeping web tension higher than some specified value.

Method of curtain coating

In a simultaneous coating of multiple layers on a web using a slide hopper type coating apparatus, the gelatin concentration of the coating liquid for the bottom layer is set to be lower than the gelatin concentration of the coating liquid for the middle layer by at least 2 points in percentage, the ratio A/B, which is the flow amount ratio of the coating liquid for the bottom layer with respect to the entire multi-layered coating liquid, is set to be between 0.05 and 0.2, and the ratio C/D, which is the viscosity ratio between the coating liquid for the bottom layer and the coating liquid of the middle layer, is set to be between 0.2 and 0.67. Thereby, the flow of the multi-layered coating liquid flowing down on the slide surface can be stabilized.

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Kanagawa, Japan

Yasuhiko Tokimasa