JP3726496B2 - Curtain application auxiliary liquid supply method - Google Patents

Description

【００５３】
評価基準
○：４８時間の連続供給で気泡の発生が無い
△：１２時間の連続供給で気泡の発生が無いが４８時間以内に発生
×：１２時間以内に気泡発生
◎：○よりも良く、故意的に混入した気泡も消滅傾向
（△，×は安定な生産に支障がある）
このように、溶存気体の飽和量以下にすることにより気泡の発生を無くすことができる。また、補助液体の流量が低い条件での使用において、気泡が発生したときに問題が大きいので本発明の採用効果が大きいことが分かる。
【００５４】
実施例２
実施例１と同じ補助液体供給システム３０により、同じ補助液体として２０℃の蒸留水（飽和溶存酸素量８．８ｐｐｍ）を用いて、殺菌装置４１の有無による配管内の水アカ発生について調べた。その結果を表２に示す。
【００５５】
【表２】

【００５６】
評価基準
○：１カ月の使用においても水アカの発生が無い
△：１０日の使用においても水アカの発生が無いが１カ月以内に発生
×：１０日以内に水アカ発生
このように、殺菌装置の効果は大きいことが分かる。
【００５７】
【発明の効果】
本発明の補助液体供給方法で、溶存気体を飽和量以下にして、気泡の発生をなくすことができ、また、殺菌装置を取り付けることにより、配管内に付着する被膜状の汚れを防止できる。このことによりカーテン塗布における幅方向端部の厚膜塗布が解消され、均一な高品質で生産性の高いカーテン塗布が長期間安定して得られるようになった。
【００５８】
特に、補助液体の流量が低い条件での生産において、気泡が発生したときに問題が大きくなるのでこの技術の採用効果が大きい。
【図面の簡単な説明】
【図１】本発明にかかわる塗布装置の側面図である。
【図２】本発明にかかわる塗布装置の斜視図である。
【図３】本発明にかかわる補助液供給システムの構成図である。
【図４】カーテン塗布における支持体端部の膜厚不均一を示す図である。
【符号の説明】
１ 塗布装置
２ スライド面
３ 塗布液供給スリット
４，４′ エッジガイド
５，５′ サイドプレート
６ 注液口
３０ 補助液体供給システム
３１ 釜
３２ 管
４１ 殺菌装置
４２ フィルター
５１ 脱気装置
６１ 流量計
６２ フラットバルブ
７１ 溶存酸素測定装置
７２ フィードバック装置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for supplying an auxiliary liquid in curtain coating using an auxiliary liquid as a side liquid. In particular, it relates to long-term stable and continuous supply of a small amount of auxiliary liquid.
[0002]
[Prior art]
The flow of the auxiliary liquid in the curtain coating method is effective in improving the coating property of the side portion and reducing the thick film, and each company has filed many patent applications as follows.
[0003]
JP-A-1-199668, JP-A-54-73365, JP-A-5-293429, JP-A-59-132966, JP-A-50-88138, JP-A-59-132966, JP-T-3 No. 500858 and JP-A 63-287574.
[0004]
These are all patents that use an auxiliary liquid, and as a result, the thick film on the side part as shown in Fig. 4 is reduced and uniform application in the width direction is achieved. The application was difficult to sustain. It can be said that stability is not considered.
[0005]
[Problems to be solved by the invention]
It is an object of the present invention to provide a curtain coating auxiliary liquid supply method that eliminates such problems in curtain coating and allows uniform coating in the width direction to be performed stably for a long time. To do.
[0006]
[Means for Solving the Problems]
As a result of the study, the present inventors have found that if the conventional auxiliary liquid supply technology in curtain coating as described above is used for a long time, problems such as generation of bubbles and generation of bacteria occur, leading to the above-mentioned poor sustainability. I found out.
[0007]
That is, the flow hunting and supply of the auxiliary liquid are interrupted by the growth of bubbles, and the film-like dirt is generated in the piping due to the generation of bacteria. This is the precise measurement part of the flow meter and the flow control valve. It has been found that this causes failure of the flat valve 62 portion. In either case, the flow rate of the auxiliary liquid is destabilized, leading to destabilization of the curtain film, the applicability of the side part is deteriorated, and drying failure due to a thick film is caused. The production process must be stopped, leading to a reduction in production efficiency.
[0008]
An object of the present invention is to solve such a problem, specifically to suppress the generation of bubbles and to suppress the generation of film-like foreign matters.
[0009]
This object is achieved by any one of the following technical means (1) to (13).
[0010]
(1) The coating liquid is allowed to flow out from the coating liquid supply slit of the coating apparatus to the slide surface, and the auxiliary liquid is allowed to flow out from the liquid inlets of the side plates provided on both sides of the slide surface. A method for supplying the auxiliary liquid in curtain coating, in which a curtain film is formed from an edge guide and the curtain film is applied to collide with a transported support;
A curtain coating auxiliary liquid supply method, wherein the amount of dissolved air in the auxiliary liquid at the auxiliary liquid supply outlet, which is the liquid injection port of the side plate, is brought into an unsaturated state.
[0011]
(2) The coating liquid is allowed to flow out from the coating liquid supply slit of the coating apparatus to the slide surface, and the auxiliary liquid is allowed to flow out from the liquid inlets of the side plates provided on both sides of the slide surface. A method for supplying the auxiliary liquid in curtain coating, in which a curtain film is formed from an edge guide and the curtain film is applied to collide with a transported support;
A curtain coating auxiliary liquid supply method, wherein a sterilizing device is provided in the curtain coating auxiliary liquid supply system to sterilize the auxiliary liquid in the system.
[0012]
(3) The coating liquid is allowed to flow out from the coating liquid supply slit of the coating apparatus to the slide surface, and the auxiliary liquid is allowed to flow out from the liquid inlets of the side plates provided on both sides of the slide surface. A method for supplying the auxiliary liquid in curtain coating, in which a curtain film is formed from an edge guide and the curtain film is applied to collide with a transported support;
The amount of dissolved air in the auxiliary liquid at the auxiliary liquid supply outlet, which is the liquid injection port of the side plate, is brought into an unsaturated state, and a sterilizing device is provided in the curtain coating auxiliary liquid supply system to assist in the system. A curtain coating auxiliary liquid supply method, wherein the liquid is sterilized.
[0013]
(4) The coating liquid is allowed to flow out from the coating liquid supply slit of the coating apparatus to the slide surface, and the auxiliary liquid is allowed to flow out from the liquid inlets of the side plates provided on both sides of the slide surface. A method for supplying the auxiliary liquid in curtain coating, in which a curtain film is formed from an edge guide and the curtain film is applied to collide with a transported support;
Curtain coating auxiliary liquid supplying method, characterized in that the bacteria sacrificed deaeration及beauty continuously auxiliary liquid between the hook for the auxiliary liquid supply to the supply outlet.
[0014]
(5) The curtain coating auxiliary liquid supply method according to any one of (1) to (4), wherein the flow rate of the auxiliary liquid is 0.3 to 3 cc / min on one side.
[0015]
(6) The curtain coating auxiliary liquid supply method according to item (5), wherein the flow rate of the auxiliary liquid is measured by a thermal mass flow meter.
[0016]
(7) The curtain coating auxiliary liquid supply method according to (5) or (6), wherein the flow rate of the auxiliary liquid is controlled using a flat valve.
[0017]
(8) The curtain coating auxiliary liquid supply method according to any one of (1) to (7), wherein a deaeration device is provided in the curtain coating auxiliary liquid supply system to perform deaeration.
[0018]
(9) The curtain coating auxiliary liquid supply method according to (8), wherein feedback is applied to the deaeration device while monitoring the dissolved oxygen amount of the auxiliary liquid.
[0019]
(10) The curtain coating auxiliary liquid supply method according to any one of (2) to (7), wherein a filter is provided between the sterilizer and the flow meter to sterilize.
[0020]
(11) The curtain coating auxiliary liquid supply method according to item (10), wherein the filter is located immediately after the sterilizer.
[0021]
(12) The curtain coating auxiliary liquid supply method according to item (10), wherein a filter different from the filter is provided immediately before the flow meter.
[0022]
(13) The curtain coating auxiliary liquid supply method according to any one of (1) to (12), wherein the coating liquid is a coating liquid containing gelatin.
[0023]
It is desirable for the dissolved gas of the auxiliary liquid to be in an unsaturated state throughout the auxiliary liquid supply system.
[0024]
Further, the degassing device includes, for example, a device that lowers the pressure of the curtain coating auxiliary liquid in the supply system via a degassing membrane, and a device that increases the temperature of the curtain coating auxiliary liquid. Each company's products can be used. Examples of the dissolved oxygen measuring device include a portable dissolved oxygen meter manufactured by Toa Denpa Kogyo Co., Ltd.
[0025]
Some sterilization apparatuses use heat, ultraviolet rays, chemicals, etc., but any sterilization apparatus may be used. Examples of the sterilizing device include a product manufactured by Funakoshi Co., Ltd., an ultraviolet water sterilizing device, Ministeria. The effect of these sterilizers is great when using auxiliary liquids such as pure water and gelatin aqueous solutions that are liable to generate bacteria.
[0026]
For deaeration, the temperature and pressure in the system are changed. However, since the pressure is low at the auxiliary liquid supply port, bubbles are often generated. For this reason, the auxiliary liquid is finally brought into an unsaturated state at the auxiliary liquid supply port.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to these. Moreover, although there are assertive expressions for terms and the like in the following description, they show preferred examples of the present invention and do not limit the meaning and technical scope of the terms of the present invention.
[0028]
First, a specific example of curtain coating which is an object of the present invention will be described. Further, in the following example, a case where a negative film is produced mainly by coating an emulsion for a photographic light-sensitive material on a photographic film support will be described. However, the present invention is not limited to this example, and a continuous film is produced. When curtain support is applied to the conveyed support, it can be applied to the production of, for example, photographic printing paper, magnetic recording materials such as magnetic tape, and information recording paper such as pressure-sensitive paper and thermal paper.
[0029]
FIG. 1 shows a curtain coating apparatus 1 according to the present invention, which performs curtain coating on a support B in a process in which the conveyance direction is reversed by a backup roller R. Further, since the coating is performed in the process in which the transport direction is reversed by the backup roller R, the coating liquid does not splash and stain the support on the upstream side in the transport direction.
[0030]
The support B is transported by transport means (not shown). Paper, coated paper, a plastic film, a resin film, a metal thin plate, or the like is used as the support to be conveyed, and can be appropriately selected in order to obtain a target object to be coated. Further, the backup roller R may be in contact with the support or not. In the case of a backup roller that does not contact the support, a so-called airbag roll that blows out fluid such as air from a large number of small holes provided on the roller surface can be used.
[0031]
The curtain coating apparatus 1 includes at least a slide surface 2, a coating liquid supply slit 3, edge guides 4 and 4 ', and side plates 5 and 5'.
[0032]
The coating liquid is uniformly supplied in the width direction from the coating liquid supply slit, and a thin film of the coating liquid is formed by flowing down the slide surface. This thin film flows down the slide surface, propagates in the form of a curtain film between a pair of edge guides 4 and 4 ′ provided at both ends of the lower end portion of the slide surface, and collides with the support B to be conveyed. A coating layer is formed.
[0033]
In addition, a predetermined number of slits for uniformly supplying the coating liquid can be provided as necessary, and the coating liquid in a thin film form can be stacked by flowing the coating liquid from the plurality of slits. FIG. 1 shows a side view of a slide surface provided with three slits.
[0034]
FIG. 2 shows a perspective view of the slide surface 2. Side plates 5 and 5 ′ are provided at both end portions of the slide surface 2 of the coating apparatus 1, and the coating liquid supplied from the slit 3 is regulated so as not to flow down from the slide surface side end. ing. The side plates 5 and 5 'are provided with a liquid injection port 6 serving as an auxiliary liquid supply outlet. The shape of the liquid injection port 6 is rectangular, and one side thereof is in contact with the slide surface. As shown in FIG. 3, the liquid injection port 6 is connected to a liquid injection mechanism, that is, a curtain coating auxiliary liquid supply system 30 and supplies auxiliary liquid (side liquid) such as gelatin solution, water, and organic solvent. By supplying the auxiliary liquid from the liquid injection port 6, the coating liquid flowing down on the slide surface 2 flows down along with the auxiliary liquid to the boundary portion between the side plates 5 and 5 'and passes through the auxiliary liquid as it is. Are propagated between the edge guides and applied to the support. Further, an equal amount of auxiliary liquid is caused to flow down from the liquid injection means on both sides, but the amount is not limited, but is generally supplied at about 0.3 to 50 cc / min. As a result, the curtain film can be stably formed, and the film thickness non-uniformity near the edge guide can be reduced.
[0035]
Further, the size and height of the cross-sectional area of the liquid injection port 6 on which the side liquid effectively acts can be appropriately designed and adjusted in consideration of the height of the coating liquid flowing down the slide surface 2.
[0036]
Since the purpose of the auxiliary liquid is to minimize the boundary layer of the falling liquid film formed in the vicinity of the edge guide, the liquid injection port 6 only needs to be on both lateral sides on the slide surface. That is, it may be on either side between the lip and the uppermost supply slit.
[0037]
Next, the curtain coating auxiliary liquid supply system 30 will be described with reference to the block diagram of FIG. However, this system is an example, and the order of each unit is not limited to that shown here. A sterilizer 41, a filter 42, a deaerator 51, a flow meter 61, and a flat valve 62 are fed between a kettle 31 containing distilled water as a curtain coating auxiliary liquid and the liquid injection port 6 of the coating device 1. Distilled water with a minute flow rate of 0.3 to 3 cc / min is uniformly supplied to the liquid injection port 6 by being connected by a pipe 32 or the like. In this system, there is no liquid feed pump, but the head difference from the hook 31 to the liquid injection port 6 is supplied as a driving force. Of course, pressure may be applied to the hook or it may be supplied using a liquid feed pump.
[0038]
The sterilizer 41 is an ultraviolet water type sterilizer manufactured by Funakoshi Co., Ltd., and a sterilizing lamp such as a ministerilea product name is simple and shows a considerable effect. In this case, since a transparent pipe is used as the pipe 32 and ultraviolet rays can be irradiated from the outside, it is convenient.
[0039]
As the deaeration device 51, a trade name GASTOR is used as an ultra-compact high-performance solvent deaeration device manufactured by LaboCotec, or a trade name degasser is used as a water-based deaeration device manufactured by ERC.
[0040]
The dissolved gas means the concentration of all gases dissolved in the liquid, but since the composition of the gas is usually constant in the atmosphere, the oxygen concentration is representatively selected and measured. That is, dissolved air can be completely identified by measuring dissolved oxygen, and this can be measured to determine the unsaturation of air.
[0041]
As the dissolved oxygen measuring device 71, a portable dissolved oxygen meter manufactured by Toa Denpa Kogyo Co., Ltd. or the like is used.
[0042]
As the flow meter 61, a thermal mass flow meter for liquid and its controller are suitable. Specifically, those for micro liquid flow manufactured by Estec Co., Ltd., trade names such as mass flow controller LV series and products manufactured by Oval Co., Ltd. The names MASFLO-OVAL, LIQUI-FLOW (MODEL F-900L series), the brand name Brooks FLOMEGA ^TM (Flow Mega) manufactured by Fisher Rosemount Japan Co., Ltd., the trade name LC-1100M liquid mass flow controller, etc. Is appropriate.
[0043]
Although the flow rate feedback control by the flow meter 61 such as this thermal mass flow meter and the controller such as the flat valve 62, the basic flow rate stability for a considerable time was obtained, but it was not yet satisfactory. . It has been found that this is due to the following reasons.
[0044]
Here, the liquid used for the auxiliary liquid is usually the same liquid temperature as the room temperature, and is 15 to 20 ° C. In the production process by curtain coating (for example, for a light-sensitive material), there are many places where the temperature is higher than this temperature, and the dissolved air as the dissolved gas is saturated, so that the dissolved gas cannot be dissolved and grows as bubbles. The growth of the bubbles interrupts the supply of the auxiliary liquid, which is a very small flow rate, or causes the flow rate to fluctuate, thereby not only eliminating the thick film phenomenon at both ends in the width direction but also disturbing the film thickness. In order to avoid this, in the auxiliary liquid supply system, it was possible to eliminate the generation of bubbles by measuring the deaeration with the deaeration device as described above to bring the dissolved gas below the saturation amount. The thick film phenomenon at both ends in the width direction is eliminated, and uniform coating can be stably maintained for a long time. This is particularly effective when the flow rate of the auxiliary liquid is low.
[0045]
Further, the above-mentioned sterilizer 41 is provided as the cause of the film-like dirt in the pipes due to the generation of bacteria, which causes the measurement part of the precise flow meter and the flat valve 62 part of the flow control valve to malfunction. It was almost solved.
[0046]
In addition, by providing the filter 42 between the sterilizer 41 and the flow meter 61, it becomes possible to capture bacteria, water stains, etc. killed by the sterilizer 41, and the flow meter 61 and the flat valve 62 are more stable. Thus, the film thickness stabilization in the width direction for a longer time is achieved. The installation location of the filter 42 may be immediately after the sterilizer 41 in the auxiliary liquid supply direction or immediately before the flow meter 61.
[0047]
Furthermore, it can be confirmed that there is no risk of bubble generation while monitoring the measured value of the dissolved oxygen measuring device 71. Further, when the amount of dissolved oxygen is increased by the feedback device 72 based on this value, the output of the deaeration device 51 can be increased.
[0048]
The auxiliary liquid supply system may be one obtained by removing only the sterilization device 41 from the auxiliary liquid supply system 30 shown in FIG. 3 or may be one obtained by removing only the deaeration device 51. However, it is more effective to provide both devices 41 and 51 together.
[0049]
The auxiliary liquid supply system 30 is configured from the location of the pot 31 where the liquid of the liquid composition to be supplied is made to the liquid injection port 6 which is an auxiliary liquid outlet.
[0050]
【Example】
Example 1
Using the auxiliary liquid supply system 30 described in the above embodiment with distilled water at 20 ° C. (saturated dissolved oxygen amount of 8.8 ppm) as the auxiliary liquid, the amount of dissolved oxygen at the injection port 6 that is the auxiliary liquid supply outlet The flow rate of the auxiliary liquid was changed and the occurrence of bubbles was investigated. The total length of the auxiliary liquid supply system at this time was about 5 m, the inner diameter of the pipe 32 of the piping was 5 mm, and a gelatin-containing solution for a photosensitive material was applied by a curtain coating method.
[0051]
The results are shown in Table 1.
[0052]
[Table 1]

[0053]
Evaluation criteria ○: No bubbles are generated by continuous supply for 48 hours. Δ: No bubbles are generated by continuous supply for 12 hours, but bubbles are generated within 48 hours. X: Bubbles are generated within 12 hours. Bubbles are also annihilated (△ and × impede stable production)
In this way, the generation of bubbles can be eliminated by making the amount less than the saturation amount of the dissolved gas. In addition, it can be seen that the use effect of the present invention is great because the problem is great when bubbles are generated in use under the condition that the flow rate of the auxiliary liquid is low.
[0054]
Example 2
By using the same auxiliary liquid supply system 30 as in Example 1, distilled water at 20 ° C. (saturated dissolved oxygen amount of 8.8 ppm) was used as the same auxiliary liquid, and the occurrence of water stains in the pipes with or without the sterilizer 41 was examined. The results are shown in Table 2.
[0055]
[Table 2]

[0056]
Evaluation criteria ○: No generation of water red even when used for 1 month △: No water red even after 10 days of use, but generated within 1 month ×: Water red is generated within 10 days In this way, sterilization It can be seen that the effect of the device is great.
[0057]
【The invention's effect】
With the auxiliary liquid supply method of the present invention, the dissolved gas can be reduced to a saturation amount or less to eliminate the generation of bubbles, and by attaching a sterilizer, film-like dirt adhering to the inside of the pipe can be prevented. As a result, thick film coating at the end in the width direction in curtain coating is eliminated, and uniform and high quality and high productivity curtain coating can be obtained stably over a long period of time.
[0058]
In particular, in the production under a condition where the flow rate of the auxiliary liquid is low, the problem becomes large when bubbles are generated, so that the effect of adopting this technique is great.
[Brief description of the drawings]
FIG. 1 is a side view of a coating apparatus according to the present invention.
FIG. 2 is a perspective view of a coating apparatus according to the present invention.
FIG. 3 is a configuration diagram of an auxiliary liquid supply system according to the present invention.
FIG. 4 is a diagram showing non-uniform film thickness at the edge of a support in curtain coating.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Coating device 2 Sliding surface 3 Coating liquid supply slit 4, 4 'Edge guide 5, 5' Side plate 6 Injection port 30 Auxiliary liquid supply system 31 Pot 32 Pipe 41 Sterilizer 42 Filter 51 Deaerator 61 Flow meter 62 Flat Valve 71 Dissolved oxygen measuring device 72 Feedback device

Claims (13)

The coating liquid is allowed to flow out from the coating liquid supply slit of the coating device to the slide surface, and the auxiliary liquid is allowed to flow out from the liquid inlets of the side plates provided on both sides of the slide surface. A method for supplying the auxiliary liquid in curtain coating, in which a curtain film is formed by applying the curtain film by colliding with a support to be conveyed;
A curtain coating auxiliary liquid supply method, wherein the amount of dissolved air in the auxiliary liquid at the auxiliary liquid supply outlet, which is the liquid injection port of the side plate, is brought into an unsaturated state. The coating liquid is allowed to flow out from the coating liquid supply slit of the coating device to the slide surface, and the auxiliary liquid is allowed to flow out from the liquid inlets of the side plates provided on both sides of the slide surface. A method for supplying the auxiliary liquid in curtain coating, in which a curtain film is formed by applying the curtain film by colliding with a support to be conveyed;
A curtain coating auxiliary liquid supply method, wherein a sterilizing device is provided in the curtain coating auxiliary liquid supply system to sterilize the auxiliary liquid in the system. The coating liquid is allowed to flow out from the coating liquid supply slit of the coating device to the slide surface, and the auxiliary liquid is allowed to flow out from the liquid inlets of the side plates provided on both sides of the slide surface. A method for supplying the auxiliary liquid in curtain coating, in which a curtain film is formed by applying the curtain film by colliding with a support to be conveyed;
The amount of dissolved air in the auxiliary liquid at the auxiliary liquid supply outlet, which is the liquid injection port of the side plate, is brought into an unsaturated state, and a sterilizing device is provided in the curtain coating auxiliary liquid supply system to assist in the system. A curtain coating auxiliary liquid supply method, wherein the liquid is sterilized. The coating liquid is allowed to flow out from the coating liquid supply slit of the coating device to the slide surface, and the auxiliary liquid is allowed to flow out from the liquid inlets of the side plates provided on both sides of the slide surface. A method for supplying the auxiliary liquid in curtain coating, in which a curtain film is formed by applying the curtain film by colliding with a support to be conveyed;
Curtain coating auxiliary liquid supplying method, characterized in that the bacteria sacrificed deaeration及beauty continuously auxiliary liquid between the hook for the auxiliary liquid supply to the supply outlet. 5. The curtain coating auxiliary liquid supply method according to claim 1, wherein the flow rate of the auxiliary liquid is 0.3 to 3 cc / min on one side. 6. The curtain coating auxiliary liquid supply method according to claim 5, wherein the flow rate of the auxiliary liquid is measured by a thermal mass flow meter. The curtain coating auxiliary liquid supply method according to claim 5 or 6, wherein the flow rate of the auxiliary liquid is controlled using a flat valve. 8. The curtain coating auxiliary liquid supply method according to claim 1, wherein a deaeration device is provided in the curtain coating auxiliary liquid supply system to perform deaeration. The curtain coating auxiliary liquid supply method according to claim 8, wherein feedback is applied to the deaeration device while monitoring the amount of dissolved oxygen in the auxiliary liquid. 8. The curtain coating auxiliary liquid supply method according to claim 2, wherein a filter is provided between the sterilizer and the flow meter to sterilize. 11. The curtain coating auxiliary liquid supply method according to claim 10, wherein the filter is located immediately after the sterilizer. The curtain coating auxiliary liquid supply method according to claim 10, wherein a filter different from the filter is provided immediately before the flow meter. The curtain coating auxiliary liquid supply method according to claim 1, wherein the coating liquid is a coating liquid containing gelatin.

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