JPH0123575Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] The present invention relates to a coating device. In particular, in the production of recording materials such as photographic light-sensitive materials such as photographic film and photographic paper, photosensitive printing plates, and magnetic recording materials such as magnetic recording tape, a continuously running long strip-shaped support (hereinafter referred to as a "web") is used. This relates to a device that applies a coating liquid such as a photographic emulsion or a magnetic agent to a surface (called .). More specifically, the present invention relates to an apparatus for coating a thin film of coating liquid by colliding it with a traveling belt-shaped support. [Prior Art] Among the methods of coating a thin film-like coating liquid by colliding with a traveling belt-shaped support, a typical method is the curtain coating method. The curtain coating method is a method in which a free-falling curtain made of one or more coating liquids is formed, and the curtain is collided with the object to be coated to form a coating film on the object. However, due to the demand for improved coating quality, high-precision coating is gradually required, and in recent years, it has been disclosed in Japanese Patent Publication Nos. 49-24133 and 49-35447. Attempts have also been made to apply curtain coating methods to fields that require particularly high precision, such as the production of photographic materials. The method disclosed in Japanese Patent Publication Nos. 49-24133 and 49-35447 involves applying one or more types of coating liquid to two supporting members (hereinafter referred to as " The material is supplied between the edges (referred to as "edge guides") to form a thin film-like free-falling curtain, which is then applied to the continuously running web. The reason why the coating liquid is supplied between the two edge guides is to regulate the coating width and to stabilize the curtain film. Regarding the structure of Edge Guide,
Publication No. 35447 discloses a tubular shape,
Furthermore, in Japanese Patent Publication No. 58-37866, the present applicant discloses a liquid injection means which has a liquid injection hole in the same direction as the flow direction of the coating liquid at the end of the edge guide on the coating liquid outflow side and discharges the liquid in a jet form. We are proposing a coating device equipped with [Problems to be solved by the invention] As described above, many improvements have been made to the curtain coating method, but not much has been made to the edge guide. Regarding edge guides, the method proposed in Japanese Patent Publication No. 58-37866 in which liquid is jetted out from a small diameter nozzle is an effective method, but the amount of jetted liquid is 5 to 10 per minute.
cc/min, and the composition near the ears is quite different from that in the center. In addition, there are disadvantages such as the thickness of the selvage becoming wider, or the tendency to form streaks of thin coating near the selvage, or disadvantages such as the fact that when the web flaps, it rubs the web and the debris gets clogged inside the cylinder. There is. [Purpose of the invention] The present invention provides a curtain coating method and apparatus in which liquid is applied by flowing from a hollow edge guide.
It is an object of the present invention to provide a coating device in which the composition near the edges is homogeneous, the distribution of coating film thickness is small, and the tip does not become clogged due to flapping of the web or the like. [Means for Solving the Problems] The above-mentioned object of the present invention is that the edge guide supporting the thin film of an apparatus for coating by colliding at least one type of coating liquid in the form of a thin film against a running belt-shaped support has a liquid injection function. This is achieved by a coating device characterized by having a pipe having a core body provided in the center thereof. Hereinafter, embodiments of the present invention will be described in more detail based on the accompanying drawings. In Figures 1 and 2, a liquid tank (not shown)
A fixed amount of the coating liquid S is fed into the cavity 4 in the slide hopper 1 via the metering pump P. The coating liquid S flows out through the slot 3 whose width is narrower than the cavity 4, flows down the sliding inclined surface 6 of the slide hopper 1 as a flowing layer 8, and flows down the tip lip of the inclined plate (hereinafter referred to as (referred to as a "rip"). In the lip 7, a free falling curtain of the coating liquid S, that is, a thin coating liquid film 9 is formed. On the other hand, a belt-shaped support 11 is running from the original roll through a pass roller 2, and a thin film-like coating liquid 9 is running.
collides with the traveling strip-shaped support 11 and the coating film 1
form 0. The two spaced apart vertical edge guides 12, 12' shown in FIG. , 12' flows downward along the outer periphery of the rod or wire serving as the core body 13, 13'. 14
is the support frame of the edge guide, and 15, 15'
is the liquid supply hose. The membrane is supported by the rod 13 or wire 13, and by directly pulling the membrane downward, the membrane can be formed at an extremely low flow rate, reducing the thickness of the film without significantly changing the composition near the ears. Moreover, since the cylindrical portion does not touch directly even when there is significant variation in the web, the cylinder will not become clogged. The inner diameter of the pipes 12, 12' in this invention is 0.2
-4 mm, preferably about 0.4-2 mm, and the outer diameter of the core rods 13, 13' or wires 13, 13' is preferably 0.05-3.9 mm, preferably 0.2-1.5 mm. . The materials of pipes 12 and 12' are SUS, copper, and aluminum.
Metals such as SS coated with a suitable plating such as CrNi, plastics such as polyethylene, Teflon (registered trademark), vinyl chloride, nylon, or ceramics may also be used. The inner rods 13 and 13' are made of SUS, copper,
Aluminum, iron wire plated with Cr, Ni, etc., or synthetic fibers such as nylon, polyethylene, etc. can be used. Also, the ends of the wires 13, 13' are connected to the pipe 12,
It extends toward the support 11 longer than the tip of the tip 12', and may touch the web surface or may be separated from it. If they are far apart, around 0.3mm is optimal. The web used in the present invention includes paper, plastic film, metal, resin coated paper, synthetic paper, and the like. The material of the plastic film includes, for example, polyolefins such as polyethylene and polypropylene, vinyl polymers such as polyvinyl acetate, polyvinyl chloride, and polystyrene;
Polyamides such as 6,6-nylon and 6-nylon, polyesters such as polyethylene terephthalate and polyethylene-2,6-naphthalate, polycarbonates, and cellulose acetates such as cellulose triacetate and cellulose diacetate are used. Further, the resin used for resin coated paper is typically polyolefin such as polyethylene, but is not necessarily limited thereto. Further, as the metal web, for example, there is an aluminum web. Coating liquids include photographic emulsion, magnetic agent, pressure-sensitive compound agent, heat-sensitive recording agent, lithographic printing coating agent, undercoat,
Other general coating liquids can be applied. In order to further clarify the effects of the present invention, examples will be introduced below, but the present invention is not limited to the examples and can be widely applied. For example, it is also applicable to multilayer simultaneous coating. Further, the coater can also be applied to a popper-type coater that does not have a sliding surface. [Example] A coating solution with a thickness of 100 μm and a coating solution having the composition and physical properties shown in Table 1 was transported at a speed of 120 m/min by a slide hopper type curtain coating device as shown in FIGS. 1 and 2. 60 c.c./m ² on a 120 cm wide polyethylene terephthalate film (warm state)
It was applied at a coating amount of . Here the curtain height is 15
cm, and the application width was 119.5 cm. In addition, the edge guide is a stainless steel pipe with an inner diameter of 2 mm and an outer diameter of 3 mm, and is partially welded at the upper end of the stainless steel pipe with an outer diameter of 1 mm.
It has a structure with a stainless steel rod of mm in diameter as the core. The lower end of the pipe part is at almost the same position as the lip part of the slide hopper, and the tip of the stainless steel rod extends about 15 cm further from this position toward the polyethylene terephthalate film, and 0.5 cm of methyl glycol is added from the pipe to each end. cc/minute pressure was delivered. Observation of the supporting part of the curtain film during the coating operation revealed that the curtain film was stable, and the thickness of the film applied to the film after drying using a thickness gauge was measured using a thickness gauge. Thick coating, thin coating, and uneven thickness were not observed.

[Comparative example]

The coating liquid with the composition and physical properties shown in Table 1 was
When coating was attempted using the coating device disclosed in Publication No. 37866 under almost the same coating conditions as in Example 1, the amount of auxiliary liquid injected from the auxiliary liquid injection pipe without a core was It took 5c.c./min. [Effects of the invention] According to the present invention, as described in the embodiment, the flow rate flowing through the guide can be reduced to about 1/10, so the composition of the ear part can be made almost the same as that of the central part, and the composition near the ear part can be reduced to about 1/10. The formation of light streaks also disappears. Furthermore, even if the tip comes into contact with the web due to web flapping, etc., the tip will not become clogged.

[Brief explanation of drawings]

FIG. 1 is a front view of the device according to the present invention, and FIG. 2 is a side sectional view thereof. 1...Slide hopper, 6...Sliding slope,
8... Lower layer, 9... Curtain liquid film, 12,1
2'...pipe, 13,13'...core, 11...
Support body, 15, 15'...hose.

Claims (1)

[Claims for Utility Model Registration] (1) An edge guide for supporting both ends of a thin film-like coating liquid of an apparatus for coating at least one kind of thin-film coating liquid by colliding with a support to be coated, the edge guide 1. A coating device characterized by being a pipe having a liquid injection function and having a core provided in the center thereof. (2) The coating device according to claim (1) of the utility model registration, wherein the tip of the core extends toward the support longer than the tip of the pipe.