JP5454044B2 - Coating liquid supply device - Google Patents

Description

  The present invention relates to a roll coating type coating liquid supply apparatus, and more particularly to a suitable one when using a highly thixotropic coating liquid.

In recent years, functional films have been actively developed, and roll coating type liquid supply devices such as gravure type are often used for coating functional films. This roll coating type coating liquid supply apparatus has an advantage that an existing coating machine can be diverted.
As a coating material for a functional film, there is a material using a coating solution having a high thixotropy (extremely low fluidity). Examples of the coating solution having high thixotropy include a coating solution for a catalyst layer for a fuel cell in which carbon and a platinum catalyst are dispersed, and a coating solution for a solar cell back sheet containing titanium oxide.

When this highly thixotropic coating liquid is used in a roll coating type coating liquid supply apparatus, there is a problem in terms of the supply of the coating liquid and the amount of the coating liquid. The reason is as follows.
Regarding the supply of the coating liquid, the high thixotropic coating liquid has extremely low fluidity, so that it is difficult to distribute the coating liquid uniformly over the entire area of the coating roll.
As for the amount of coating solution, the roll coating method attaches the coating solution stored in the coating solution pan to the coating roll, so a large amount of coating solution is required in the coating solution pan. In addition, it is disadvantageous as a production method of a coating solution having a high thixotropy used for functional films and the like that have a very high unit price of liquid compared to ordinary inks. In order to produce such a functional film by a roll-to-roll method with high production efficiency, it was necessary to introduce an expensive die coating method or the like as an equipment investment.

In addition, since the roll coating method stores a large amount of coating liquid in the coating liquid pan, there is a lot of remaining coating liquid in the coating liquid pan at the end of coating, and indirect operations such as washing large coating liquid pans. take time. In addition, since it is necessary to increase the circulation amount of the coating liquid, devices such as a pump and a tank that circulate the coating liquid become large, resulting in an increase in cost.
Here, for example, apparatuses of Patent Documents 1 and 2 are known as techniques capable of reducing the amount of remaining coating liquid and the circulation amount of the coating liquid and easily cleaning the coating apparatus.

JP 2003-39637 A JP 2004-195665 A

However, if the apparatus of patent documents 1 and 2 uses a highly thixotropic coating solution, the coating solution cannot be uniformly attached in the width direction of the roll surface of the coating roll. This is particularly noticeable when the width direction of the roll surface exceeds 2 m.
That is, the coating liquid in the coating liquid pan adheres when the liquid surface and the roll surface of the coating roll come into contact with each other, but the high thixotropic coating liquid with low fluidity has a width of the coating roll. It does not spread in the direction, gaps are generated between the roll surface and the liquid surface, and coating defects such as coating omission and variation in coating film thickness are likely to occur. In addition, the problem that a space | gap generate | occur | produces in the coating roll and the liquid surface of a highly thixotropic coating liquid appears notably when the rotation speed of a coating roll, ie, a coating speed, is large.

  The present invention has been made in view of such problems, and even when a highly thixotropic coating solution is used, coating defects such as coating omission and coating film thickness variation can be prevented. It is an object of the present invention to provide a roll coating type coating liquid supply device that can reduce the amount of the remaining working liquid and the circulation amount of the coating liquid, facilitate cleaning, and reduce the indirect time.

In order to achieve the above object, the coating liquid supply device according to claim 1, the coating liquid pan for storing the coating liquid, and the lower side of the roll surface is immersed in the coating liquid in the coating liquid pan, A coating roll for adhering the coating liquid supplied to the roll surface by rotation to a web-like substrate to be coated, and a coating liquid sent from the outside to temporarily accumulate in the coating liquid pan A supply unit that supplies the coating liquid to the inside of the coating liquid pan so that the supply unit has a uniform supply amount in the width direction of the roll surface. A hollow-shaped supply unit main body that is connected to the coating liquid pan along the width direction of the roll surface, and is formed at the bottom of the supply unit main body, and the coating liquid from the outside Is formed on the upper part of the supply part main body, and the width of the roll surface. When the coating liquid accumulates in the entire interior of the supply section main body and the supply section main body, or a plurality of coating liquid supply openings that are open in a row along the width direction of the roll surface. And a supply amount control member for controlling the supply amount of the coating liquid flowing out from the coating liquid supply opening toward the coating liquid pan to be uniform in the width direction of the roll surface.

According to this invention, since the supply unit is configured to feed a uniform supply amount of the coating liquid in the width direction of the roll surface, even if a highly thixotropic coating liquid with extremely low fluidity is used, No gap is generated between the entire width direction of the roll surface and the coating liquid, and the occurrence of coating defects such as coating omission and coating film thickness variation is prevented.
In addition, even if the liquid surface is in a non-uniform state and the high thixotropic coating liquid accumulates inside the supply unit body, the supply amount control member is configured so that the supply amount of the coating liquid is in the width direction of the roll surface. In this case, the supply of the coating liquid that becomes non-uniform in the process is prevented.
Further, the invention of claim 2 is the coating liquid supply apparatus according to claim 1, wherein the shape of the bottom of the coating liquid pan for storing the coating liquid is shaped like a bowl close to the lower side of the roll surface. By forming, the coating liquid flow path between the bottom part of this bowl shape and the lower side of the said roll surface was narrowed.

  According to this invention, by narrowing the coating liquid flow path between the bottom of the coating liquid pan formed in the bowl shape and the lower side of the roll surface, the entire coating liquid flowing through this coating liquid flow path By applying shear, the viscosity of the coating solution with high thixotropic properties can be lowered and the fluidity can be increased, and the retention amount of the coating solution with high thixotropic properties in the coating solution pan can be reduced. The remaining amount of coating liquid and the amount of circulation are reduced.

The invention according to claim 3 is the plate spring according to claim 1 or 2 , wherein the supply amount control member is disposed on the upper part of the supply unit main body along the width direction of the roll surface. The plate spring closes the coating liquid supply opening when the coating liquid does not accumulate in the entire area inside the supply section main body, while the coating liquid covers the entire area inside the supply section main body. Is accumulated by the coating liquid passing through the coating liquid supply opening and warped upward, and the amount of warpage in the direction along the width direction of the roll surface is constant. did.
According to this invention, since the amount of warping of the leaf spring in the direction along the width direction of the roll surface is constant, the supply amount of the coating liquid is made uniform in the width direction of the roll surface. A supply unit can be provided.

Furthermore, the invention according to claim 4 is the coating liquid supply apparatus according to any one of claims 1 to 3 , wherein the supply unit main body includes an opening capable of cleaning the inside of the supply unit main body. In addition, the opening is closed by a detachable closing member.
According to this invention, since the inside of the supply unit body can be cleaned from the opening by removing the closing member fixed to the supply unit body, the indirect time can be shortened.

  According to the coating liquid supply apparatus according to the present invention, the supply unit is configured to feed a uniform supply amount of the coating liquid in the width direction of the roll surface, so that the high thixotropic coating liquid has extremely low fluidity. Even if it is used, no gap is generated between the entire width direction of the roll surface and the coating liquid, and it is possible to prevent the occurrence of coating defects such as coating omission and coating film thickness variation.

It is a perspective view which shows the external appearance of the coating liquid supply apparatus which concerns on this invention. It is the perspective view which shows the coating liquid pan which comprises the coating liquid supply apparatus which concerns on this invention, (a) shows from the side which attaches a supply part, (b) is the figure shown from the coating liquid collection | recovery part side. It is the disassembled perspective view which showed the supply part which comprises the coating liquid supply apparatus which concerns on this invention. In the coating liquid supply apparatus which concerns on this invention, it is the figure which showed the state which stores the coating liquid of high thixotropy temporarily in a supply part, and supplies the coating liquid to a coating liquid pan.

DESCRIPTION OF EMBODIMENTS Hereinafter, modes for carrying out the present invention (hereinafter referred to as embodiments) will be described in detail with reference to the drawings.
FIGS. 1 to 3 show an embodiment of a roll coating type coating liquid supply apparatus.
As shown in FIG. 1, the coating liquid supply apparatus according to the present embodiment includes a coating liquid pan 1 in which a predetermined amount of coating liquid is stored, and a coating liquid in the coating liquid pan 1. A coating roll 2 in which the lower side is immersed and rotated around the axis of arrow A, and the roll surface 2a is brought into contact with the web-like coated substrate 4 conveyed in the direction of arrow B to attach the coating liquid; It is integrated with the coating liquid pan 1 so as to face the entire width direction (longitudinal direction along the axial direction) of the roll surface 2a immediately before being immersed in the coating liquid in the coating liquid pan 1, and from the outside. Rotate around the axis of arrow C while sandwiching the substrate to be coated 4 between the supply roll 3 that temporarily stores the pumped coating liquid and supplies it to the coating liquid pan 1 and the coating roll 2. And the impression cylinder 5 which transfers a coating liquid to the to-be-coated base material 4, and the roll surface 2a immediately after being immersed in the coating liquid in the coating liquid pan 1, as shown in FIG. The doctor blade 6 that contacts and sets the supply amount of the coating liquid to the roll surface 2a, and the coating liquid recovery unit that is integrated with the coating liquid pan 1 and collects the coating liquid scraped off by the doctor blade 6 7. The coating liquid collected in the coating liquid collection unit 7 is collected in a coating liquid tank (not shown) by driving a collection pump (not shown).

  As shown in FIGS. 2 (a) and 2 (b), the coating liquid pan 1 has a bottom portion facing the lower side of the roll surface 2 a of the coating roll 2 in a bowl shape. That is, the bowl-shaped bottom of the coating liquid pan 1 rises obliquely upward from the longest bottom plate 8 close to the bottom of the roll surface 2a and one widthwise edge of the bottom plate 8. The upstream bottom plate 9 close to the roll surface 2a immediately before being immersed in the coating solution in the coating solution pan 1 and the other bottom edge in the width direction of the lowermost bottom plate 8 rise obliquely upward, and the coating solution pan 1 It is comprised with the downstream bottom board 10 close | similar to the roll surface 2a immediately after being immersed in the inner coating liquid.

The downstream bottom plate 10 has a coating liquid recovery slit 11 for allowing the coating liquid scraped off by the doctor blade 6 or a coating liquid not adhered to the coating roll 2 to flow down to the coating liquid recovery unit 7. Is formed.
A support plate 12 for integrating the supply unit 3 is fixed to the upstream bottom plate 9 side of the coating liquid pan 1 so as to protrude outward.

  As shown in FIG. 3, the supply unit 3 has a hollow rectangular parallelepiped shape, a supply unit main body 14 having an opening 13 on one side in the longitudinal direction, and a top plate 14 a of the supply unit main body 14 in the longitudinal direction. Coating liquid supply slits 15 formed continuously, a plurality of coating liquid press-fitting holes 16 opened at predetermined intervals in the longitudinal direction of the bottom plate 14b of the supply section main body 14, and the plurality of coating liquids Connected to the work fluid press-fitting hole 16, the piping part 17 for pumping the coating liquid from the coating liquid tank (not shown) into the supply part main body 14 and the entire area of the opening 13 are in a liquid-tight state via the packing 18. A plate spring 20 that is closed by screwing, a plate spring 20 that contacts the upper portion of the upper plate 14a of the supply unit main body 14 and blocks the coating coating supply slit 15 from above, and one of the plate springs 20 A leaf spring holding block 21 for fixing the portion to the upper plate 14a with screws. With and is fixed in a state where the bottom plate 14b of the supply part main body 14 is in contact with the support plate 12 of the coating liquid pan 1 described above.

The leaf spring 20 has one side in the longitudinal direction (the portion indicated by reference numeral 22 in FIGS. 1 and 3) close to the upstream bottom plate 9 of the coating liquid pan 1 via the leaf spring restraining block 21. It is not fixed to the upper plate 14a, and only the side portion 22 side is elastically deformable upward.
The piping unit 17 includes a main pipe 17a to which a coating liquid is pumped from a coating liquid tank (not shown), and a plurality of branch pipes 17b that branch from the main pipe 17a and connect to the coating liquid press-fitting holes 16.
It consists of and. Each branch pipe 17b is provided with a pressure adjustment valve 17c such as a ball valve, and the pressure fluctuation due to the difference in the pipe path length of the branch pipe 17b can be adjusted by the pressure adjustment valve 17c.

Next, using the roll coating type coating liquid supply apparatus having the above-described configuration, a coating solution having a high thixotropy (extremely low fluidity) is applied as a coating material to the coated substrate 4 that is a functional film. The operation and action when adhering will be described with reference to FIG.
As shown in FIG. 4A, the highly thixotropic coating liquid L that has been pressure-fed from the coating liquid tank to the supply section 3 via the piping section 17 is supplied from the coating liquid press-fitting hole 16 into a hollow supply section. It is supplied into the main body 14.
As shown in FIGS. 4B and 4C, the high thixotropic coating liquid L stored in the supply unit main body 14 is liquid in a state where the mountain shape in the vicinity of the coating liquid press-fitting hole 16 is maintained. The surface gradually rises.

  Next, the highly thixotropic coating liquid L stored in the supply section main body 14 is removed from the coating liquid supply slit 15 when the top of the mountain-shaped liquid surface reaches the upper plate 14a of the supply section main body 14. It tries to flow out to the coating liquid pan 1 side. However, due to the restoring force of the leaf spring 20 that closes the coating liquid supply slit 15, the inside of the supply unit body 14 is kept hermetically closed, and as shown in FIG. However, the inside of the supply unit main body 14 is filled with the coating solution L having a high thixotropy.

  When the thixotropic coating liquid L is stored in the entire area inside the supply unit main body 14 and the internal pressure of the coating liquid L in the supply unit main body 14 becomes larger than the restoring force of the leaf spring 20, FIG. As shown in (e), the high thixotropic coating liquid L that has passed through the coating liquid supply slit 15 warps the side 22 side of the leaf spring 20 upward while the upstream bottom plate of the coating liquid pan 1. It will flow towards 9. At this time, the amount of warpage of the leaf spring 20 on the side portion 22 side is constant in the longitudinal direction due to the restoring force of the leaf spring 20 itself, so that the high thixotropy flowing from the supply section main body 14 toward the coating liquid pan 1 is obtained. The supply amount of the conductive coating liquid L is uniform in the width direction of the coating roll 2.

  Further, as shown in FIG. 4 (e), the bottom portion of the bowl shape of the coating liquid pan 1 has a long bottom plate 8 that is close to the bottom of the roll surface 2a, and the coating in the coating liquid pan 1. It is composed of an upstream bottom plate 9 close to the roll surface 2a immediately before being immersed in the working liquid and a downstream bottom plate 10 close to the roll surface 2a immediately after being immersed in the coating liquid in the coating liquid pan 1. Since the coating liquid flow path formed by the coating roll 2 and the bowl-shaped bottom of the coating liquid pan 1 is narrowed, the coating liquid narrowed by rotating the coating roll 2. Shearing is applied to the entire coating liquid flowing through the flow path to reduce the viscosity of the highly thixotropic coating liquid L and increase the fluidity. Thus, by increasing the fluidity of the coating solution L having a high thixotropy, the amount of residence of the coating solution L having a high thixotropy in the coating solution pan 1 can be reduced.

  Therefore, according to the coating liquid supply apparatus of the present embodiment, the coating liquid L formed on the upper plate 14a of the supply section main body 14 by the high thixotropic coating liquid L supplied from the supply section 3 to the coating liquid pan 1 is used. When passing through the supply slit 15, the upward warping amount on the side 22 side of the leaf spring 20 becomes constant in the longitudinal direction due to the restoring force of the leaf spring 20 itself, whereby the high thixotropic coating liquid L Since the supply amount is also uniform in the width direction of the coating roll 2, no gap is generated between the width direction of the roll surface 2a and the highly thixotropic coating liquid L. Occurrence of coating defects such as variations can be prevented.

Moreover, the coating liquid flow path formed by the roll surface 2a of the coating roll 2 and the bowl-shaped bottom of the coating liquid pan 1 is narrowed, and is narrowed by rotating the coating roll 2. By applying shear to the entire coating liquid flowing through the coating liquid flow path to reduce the viscosity of the high thixotropic coating liquid L and increase the fluidity, the high thixotropic coating liquid L in the coating liquid pan 1 is used. Therefore, the amount of remaining meat and the amount of circulation of the coating solution L having a high thixotropic property can be reduced.
In addition, since the amount of warpage of the leaf spring 20 in the direction along the width direction of the roll surface 2a is constant, the supply amount of the coating solution L having a high thixotropic property is made uniform in the width direction of the roll surface 2a. Therefore, a simple supply unit 3 can be provided.

Further, by removing the packing 18 and the blocking plate 19 fixed to the supply unit main body 14, the inside of the supply unit main body 14 can be cleaned from the opening 13, so that the supply unit 3 can be easily cleaned. Indirect time can be shortened.
In the above embodiment, the coating liquid supply slit 15 is formed continuously in the longitudinal direction on the upper plate 14a of the hollow supply part main body 14 constituting the supply part 3. It is not limited, When a plurality of coating liquid supply holes are formed at predetermined intervals in the longitudinal direction of the upper plate 14a, and the highly thixotropic coating liquid L is stored in the entire area inside the supply unit body 14 In addition, a structure in which the highly thixotropic coating liquid L flows from the plurality of coating liquid supply holes to the outside may be used.

  DESCRIPTION OF SYMBOLS 1 ... Coating liquid pan, 2 ... Coating roll, 2a ... Roll surface, 3 ... Supply part, 4 ... Coated substrate, 5 ... Impression cylinder, 6 ... Doctor blade, 7 ... Coating liquid collection | recovery part, 8 DESCRIPTION OF SYMBOLS ... Lowermost bottom plate, 9 ... Upstream side bottom plate, 10 ... Downstream side bottom plate, 11 ... Coating liquid collection | recovery slit, 12 ... Support plate, 13 ... Opening part, 14 ... Supply part main body, 14a ... Top plate, 14b ... Bottom plate, DESCRIPTION OF SYMBOLS 15 ... Coating liquid supply slit (Coating liquid supply opening part), 16 ... Coating liquid press-fitting hole (Coating liquid press-fitting part), 17 ... Piping part, 17a ... Main piping, 17b ... Branch piping, 17c ... Pressure adjustment Valve 18, packing 19, closing plate (blocking member), 20 plate spring (supply amount control member), 21 plate spring restraining block, 22 side part of plate spring, L ... coating solution with high thixotropy

Claims (4)

A coating liquid pan for storing the coating liquid, and the lower part of the roll surface is immersed in the coating liquid in the coating liquid pan, and the coating liquid supplied to the roll surface by rotation is applied in a web-like manner In a coating liquid supply apparatus comprising: a coating roll attached to a substrate; and a supply unit that temporarily stores a coating liquid sent from the outside and supplies the coating liquid into the coating liquid pan.
The supply unit is configured to supply the coating liquid into the coating liquid pan so that the supply amount is uniform toward the width direction of the roll surface, and the width along the roll surface is A hollow-shaped supply unit main body that is connected to the coating liquid pan, a coating liquid press-fitting unit that is formed at the bottom of the supply unit main body, and into which the coating liquid is pressed from the outside, and the supply unit main body A coating liquid supply opening that is formed in the upper portion and that is continuous in the direction along the width direction of the roll surface, or that is open in a plurality along the direction along the width direction of the roll surface, and the inside of the supply unit main body When the coating liquid is accumulated in the entire area, the supply amount of the coating liquid flowing out from the coating liquid supply opening toward the coating liquid pan is controlled to be uniform in the width direction of the roll surface. And a supply amount control member .   By forming the shape of the bottom of the coating liquid pan for storing the coating liquid into a bowl shape that is close to the lower side of the roll surface, between the bottom of the bowl shape and the lower side of the roll surface The coating liquid supply apparatus according to claim 1, wherein the coating liquid flow path is narrowed. The supply amount control member is configured by a leaf spring disposed along the width direction of the roll surface at the upper part of the supply unit main body,
This leaf spring, said when the coating solution within the entire area of the supply part main body is not accumulated whereas closing the coating liquid supply opening, the coating solution is collected inside the whole area of the supply unit main body Sometimes, it is pushed up by the coating liquid passing through the coating liquid supply opening and warps upward, and the amount of warpage in the width direction of the roll surface is constant. The coating liquid supply apparatus according to claim 1 or 2 . The said supply part main body is provided with the opening part which can wash | clean the said supply part main body inside, and the said opening part is obstruct | occluded with the detachable obstruction | occlusion member, The any one of Claim 1 thru | or 3 characterized by the above-mentioned. The coating liquid supply apparatus of Claim 1 .

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