Production apparatus of multilayer coating film

Abstract

A method for forming multiple coating layers produces a coating construction that has flexibility corresponding to the number of layers of multiple coating layers, by which a multilayer coating film can be produced with small film thickness without adherence of dust to a film surface, a drying fault such as unevenness induced by drying-wind on the film surface, or a coating fault such as a level variation and a streak. The multilayer coating film has a coating surface state of high quality with coating thickness deviation of 3% or less. In the method, a belt-like substrate is continuously fed. A coating/drying step follows, with multiple steps performed in a single unit. A plurality of coating layers are formed by sequentially performing the coating/drying step by multiple units. Finally, the belt-like substrate with the multiple coatings is continuously wound.

Description

[0001] This application is a division of co-pending application Ser. No. 10 / 341,245, filed on Jan. 14, 2003, the entire contents of which are hereby incorporated by reference.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a production apparatus of a multilayer coating film, and particularly to a production apparatus of a multilayer coating film which produces function films such as a wide view angle film and an antireflection film that are used for liquid crystal displays. [0004] 2. Description of the Related Art [0005] Recently, various kinds of function films such as a wide view angle film and an antireflection film are widely used for a liquid crystal display. This function film needs to have a small film thickness, no adherence of dust to a coating surface, no coating fault such as a level variation and a streak, and no drying fault such as unevenness on the surface induced by drying-wind, and it further needs to have a high ...

AI Technical Summary

Benefits of technology

[0015] Concerning dust prevention, which is important to prevent dust adhering to the film surface, a fan filter unit is provided at an air inlet port formed at a ceiling surface of a casing of each device, an air exhaust port is formed at a bottom surface of the casing, and clean air blown into the casing from the fan filter unit is exhausted from the air exhaust port. As a result, a down flow of clean air can be formed in the casing of each device, and cleanliness inside the casing can be improved. In addition, the fan filter unit is provided at each casing, and therefore cleanliness according to the treatment of each device such as dust removing, coating, surface inspection and the like can be formed inside the casing.

[0016] Further, a transfer path in each device is enclosed by a transfer path case, which has an inlet port and an outlet port for the web and has an air introduction port and an air exhaust port, along the transfer path, and clean air is supplied into the air introduction port. As a result, the transfer path in which the web is exposed to dust the most easily can be made a slim transfer path case with a small volumetric capacity, which is corresponding to the transfer path, therefore making it possible to prevent the wind speed of the clean air supplied into the transfer path case from decreasing, and a dead zone where clean air does not flow from occurring. As a result, dust prevention for the web can be performed with a small amount of clean air, and an air amount supplied into the casing can be reduced, and the total air amount can be made small.

[0017] As for the dryer important to prevent a drying fault such as unevenness induced by drying-wind on the film surface, the dryer is divided into three or more drying zones along the transfer direction of the web, a supply device whi...

Problems solved by technology

Since the above-described high quality is demanded, the function film with the high quality coating surface cannot be efficiently produced with an ordinary coating device.

For example, with a coating device equipped with one coater and a dryer, a web has to be repeatedly passed through the coating device as many times as the number of layers to perform multilayer coating, thus causing the disadvantage that a large variation occurs to the quality, and production efficiency becomes extremely low.

Only in terms of quality, it is considered to perform multilayer coating with a spattering device, but the production speed is extremely low with 1 m/min, and the production cost is too high, thus making it difficult to be adopted.

However, the multilayer coating apparatus is limited to three layer coating at the maximum in terms of operability because a delivery device and a winder for the web should not be far from the coater.

This apparatus ha...

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