JP2001087697A - Bar coating apparatus and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bar coating apparatus and method enabling any person to easily obtain a coating film uniform in film thickness distribution and usable even in the coating of a product requiring high film thickness accuracy. SOLUTION: In a coating apparatus for coating a continuously fed web by using a bar, the straightness of the bar is 0.025 mm or less per length of 1 m.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bar coating apparatus for applying a coating liquid to a continuously transported belt-like support using a bar, and a coating method using the apparatus.

[0002]

2. Description of the Related Art Conventionally, as a method of applying a coating liquid to a continuously running belt-like support (hereinafter, also referred to as a web), various coating apparatuses and coating methods using the apparatuses have been proposed. I have. For example, dip coating device, roll coating device, fountain coating device, comma coating device,
Examples include an air knife coating device, a blade coating device, a bar coating device, and a slide hopper coating device. Further, not only a coating method using the coating device alone but also a coating method using the coating device in combination is known. For example, a bar coating method is known as one of the methods for easily coating a continuously conveyed web in the coating apparatus. In contrast to a method of directly applying a measured coating solution to a web such as an extrusion coating method, as a first step, an appropriate amount of a coating solution is applied to a web by a roll coating apparatus, and the excess solution (primary film) is applied. This is a method in which a desired film thickness (secondary film) is obtained by pressing a bar with a bar coating device (the bar is stationary or rotating) to scrape off excess coating liquid. The final film thickness after scraping is determined only by the cross-sectional area of the groove formed in the bar, and is hardly affected by the application amount of the primary film or the web transport speed, and does not require setting of a complicated coating machine, It is widely used as a simple coating method. In recent years, this coating method has been frequently used for thin film / high speed coating.

[0003] Each of the above-mentioned coating devices can be used as a device for applying an excess coating solution in combination with a bar coating device, but generally, a dip coating device, a roll coating device, a fountain coating device, a comma Each device such as a coating device is used. Further, as described in JP-A-6-17312, a coating apparatus in which the excessive coating and the bar coating apparatus are integrated may be used.

[0004] Such a bar coating apparatus is disclosed in, for example, Japanese Patent Publication Nos. 58-4589 and 59-32190, and Japanese Utility Model Laid-Open Publication No. 1-92270 discloses an improvement in the coating width distribution in a bar coating method. Japanese Patent Application Laid-Open Nos. 6-170312 and 6-1 disclose a rod for a coating apparatus that uniformly forms a coating while preventing wear of the rod by forming a convex portion and shaving off the convex portion.
Japanese Patent Application Laid-Open Nos. 9-108613 and 9-10 disclose a coating method in which the angle of a bar abutting on a web surface is specified in JP-A No. 70313.
No. 8614 shows the distance of the transport rolls arranged before and after the bar,
The shape is described.

[0005]

However, in a bar coating method using a bar coating apparatus, there is almost no means for applying a coating solution to a web with high accuracy and uniformity. At present, they rely on the intuition, experience, and know-how of the elderly. The above-mentioned prior art also discloses a description regarding the life of the bar and a description regarding the transport roll, but does not clarify the coating uniforming device. Therefore, it is necessary to repeat trial and error to perform highly accurate uniform coating with bar coating,
Skills are required and uniform application is not readily possible, so bar application has been used exclusively for application of products that do not require film thickness accuracy.

An object of the present invention is to provide a bar coating method using a bar coating apparatus, in which anyone can easily obtain a coating film having a uniform film thickness distribution and to apply a product requiring high film thickness accuracy. Another object of the present invention is to provide a bar coating apparatus and a method which can be used.

[0007]

The above object can be solved by the following constitution of the present invention.

[0008] 1) In a coating apparatus for coating a continuously conveyed belt-shaped support using a bar, the straightness of the bar is 0.025 mm or less per 1 m of the bar length. apparatus.

2) A coating apparatus for coating a continuously conveyed belt-shaped support using a bar, wherein the deflection of the bar is 0.3 mm or less per 1 m of bar length. .

3) In a coating apparatus for applying a bar to a continuously conveyed belt-like support using a bar, a holder for preventing deflection of the bar is provided on a side of the bar opposite to the band-like support.
The straightness of the holder is 0.3m per 1m of holder length
m or less.

4) The bar coating apparatus according to 3), wherein the deflection preventing holder is formed of a metal having a lower hardness than the outermost peripheral surface of the bar.

(5) The bar coating apparatus according to (3) or (4), wherein the deflection preventing holder has an adjustment mechanism that enables uniform adjustment of contact with the bar.

[0013] 6) The adjusting mechanism includes a mechanism capable of moving the holder position at least at two or more places in the width of the band-shaped support member in a direction at least substantially perpendicular to the band-shaped support member with the bar interposed therebetween, and position detection. The bar coating device according to the item 5), further comprising a mechanism capable of performing the bar coating.

7) In a coating apparatus for applying a bar to a continuously transported band-shaped support using a bar, a holder for preventing deflection of the bar is provided on the opposite side of the bar from the bar-shaped support, and the bar convex portion is provided. The gap between the surface and the holder is 0 to 0.1
mm.

8) The bar is a wire bar in which a wire is wound around a rod or a wireless bar in which a groove having a predetermined depth and width is provided in the rod.
The bar coating device according to 2), 3), 4), 5) or 6).

9) The coating method according to 7), wherein the bar is a wire bar in which a wire is wound around a rod or a wireless bar in which a rod having a predetermined depth and width is provided.

10) A continuously transported belt-like support
In a wire bar coating apparatus for applying a wire using a bar wound around a rod, the variation in the cross-sectional area of the wire over the entire length of the wire wound around the rod is within an allowable range of the variation in width and thickness. A bar coating device, comprising:

11) A belt-like support which is continuously conveyed,
What is claimed is: 1. A wireless bar coating apparatus for coating a rod using a bar provided with a groove having a predetermined depth and width, wherein a variation in a cross-sectional area of the groove is within an allowable range of a variation in a film thickness in a width direction. Coating device.

12) The belt-shaped support which is continuously conveyed
In a coating apparatus for coating using a bar, the bar parallel to the bar of a transport roll of the belt-shaped support provided immediately before and immediately after the bar is 2 mm or less per 1 m of the roll. Coating device.

13) A belt-like support which is continuously conveyed,
In a coating apparatus for coating using a bar, the straightness of a transport roll of the belt-shaped support provided immediately before and immediately after the bar is 0.3 mm or less per 1 m of the roll length. Coating device.

14) A belt-like support that is continuously conveyed
A coating device for coating using a bar, wherein the bar is rotatable about the center of the cross section of the bar as an axis, and the axial deflection of the rotation is 0.1 mm or less in a direction perpendicular to the axis. .

15) On the belt-like support which is continuously conveyed,
A coating method using a bar, wherein the flatness of the belt-shaped support is 2 mm or less between rolls before and after the bar.

16) A belt-like support that is continuously conveyed
In a coating method using a bar, a straightness of the bar is 0.025 mm or less per 1 m of bar length, and the straightness of the bar is 0.3 mm or less per 1 m of length. A holder is provided on the opposite side of the bar-shaped support of the bar, and the holder position is movable at least in a direction substantially perpendicular to the band-shaped support with the bar interposed therebetween. The deflection of the bar is 0.3 mm per 1 m of bar length
Hereinafter, the gap between the bar and the holder is 0 to 0.1 mm.
A coating method characterized in that the coating is carried out by adjusting the temperature.

17) The thickness of the belt-like support is 75 μm or more, 1), 2), 3), 4),
5), 6), 8), 10), 11), 12), 13) or 14).

(18) The thickness of the belt-like support is 75 μm or more, (7), (9), (15) or (1).
6) The coating method according to the item.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The bar coating apparatus and the coating method using the apparatus according to the present invention are not particularly limited as long as they are apparatuses and coating using a bar. Hereinafter, embodiments of the present invention will be described with reference to the drawings. For example, FIG. 1 shows an outline of a method of applying an excess liquid and then scraping off the excess liquid. 2,
Reference numeral 2 'denotes a roll for supporting and transporting the web 3 running continuously on an inclined plane, reference numeral 4 denotes a coating apparatus for applying an excessive liquid to form a primary film, and reference numeral 1 denotes a coating film for scraping off the excess coating liquid to obtain a desired film thickness (2
2 shows a bar coating apparatus for forming a second film. Reference numeral 5 denotes a container for receiving the excess coating solution scraped off by the bar coating device, which is stored in the primary storage container 6 and returned to the coating device 4 by the circulation pump 7.

FIGS. 2A, 2B, and 2C are enlarged schematic views of the bar coating apparatus 1, and the numbers in the figures have the same meaning. Reference numeral 3 denotes a web. Reference numeral 8 denotes a bar. One end of the bar is connected to a tension adjusting unit, and the other end is connected to a mechanism that rotates forward (reversely, if necessary, fixed) with respect to the transport direction of the web 3. I have. Reference numeral 9 denotes a holder for supporting the bar 8, and has an outer cylinder 10 having fine screws 11 for adjusting the positions of the bar 8 and the holder 9 (adjustment mechanism). The means for adjusting the position is not limited to the fine screw, and another method may be used. or,
The outer cylinder has a measuring device 12 for measuring the degree of adjustment and a mounting jig 13 for mounting the measuring device. The adjusting mechanism needs at least two places in the width direction of the holder 9. Reference numeral 14 denotes a frame on which the bar coating device is mounted, and reference numeral 15 denotes a cylinder of a moving mechanism for moving the bar coating device back and forth with respect to the web. (A) shows a case where the coating width is wide and the bar is long, and the measuring device 12 and the mounting jig 13 are also mounted on the center of the outer tube portion 10, and (b) and (c) show both ends of the web width. Measuring device 12 and mounting jig 13 outside the part
Are attached only to both end portions of the outer cylindrical portion 10.

FIG. 3 is a schematic diagram of a system in which the application of the excess coating solution and the scraping of the excess coating solution are performed at the same place as described in JP-A-6-17312. In the figure, reference numeral 31 denotes a bar coating apparatus having a desired film thickness, which is basically the same as the coating apparatus shown in FIG. Numerals 32 and 32 'denote rolls for supporting and transporting the web 33 running horizontally continuously, and 34 a receiving container for the scraped coating liquid.
Reference numeral 5 denotes a primary storage container for the coating liquid, and reference numeral 36 denotes a pump for supplying the coating liquid.

Reference numeral 37 denotes a bar. The bar has a mechanism for rotating forward (reversely rotating and fixing as necessary) with respect to the transport direction of the web 33, and is supported by a holder 39. The holder 39 has an outer cylindrical portion 40 having a bar 37 and a fine screw 38 for adjusting the position of the holder 39 (adjustment mechanism). Reference numeral 41 denotes a base on which the bar coating device is mounted,
Reference numeral 42 denotes a cylinder of a moving mechanism for moving the bar coating device back and forth with respect to the web. Although not shown in the drawing, a position measuring device shown in FIGS. 2A and 2B can be similarly attached to the outer cylinder 40.

Next, FIG. 4 is a schematic view of the holder position adjusting mechanism and the bar longitudinal movement mechanism as viewed from the back side of the support of the bar coating apparatus shown in FIG. Incidentally, FIG.
This is an example in the case of using the bar coating device indicated by. In the figure, reference numeral 3 denotes a web. Numeral 8 denotes a bar, both ends of which are held by bar holding portions 16, one of which has a tension adjusting portion 17 and the other of which is provided with a motor 18 for rotation. Reference numeral 9 denotes a holder for supporting the bar 8,
The holder has an outer cylinder portion 10 having fine screws 11 for adjusting the position of the holder portion 9 and the bar 8 (adjustment mechanism). The fine screw 11 attached to the outer tube portion 10 is attached to at least a portion corresponding to the side surface and the bottom surface of the holder portion, and is disposed toward the center portion of the outer tube portion 10 according to the length of the bar 8. Is possible. Further, the bar holding part 16 and the outer cylinder part are disposed on the gantry 14, and the gantry is provided with a fore-and-aft moving cylinder 15 for adjusting the distance between the bar 8 and the web 3, so that the fore-and-aft movement is possible. Has become.

FIG. 5 is a schematic side view as seen from the direction in which the tension adjuster is mounted. The numbers in the figure are those in FIG.
It is synonymous with the number.

Next, the bar used in the present invention will be described. In order to apply the bar uniformly in the width direction in the bar application, it is essential that the bar uniformly contacts the entire width of the web and the excess coating solution is uniformly scraped off. To achieve this, it is important to keep the bar linear.

The bar used in the present invention is a bar in which a piano wire or a stainless steel wire or the like is densely wound around a rod (referred to as a wire bar), and a bar having a predetermined depth on the surface of the rod.
It includes a bar in which grooves having a width are provided at a predetermined pitch (called a wireless bar). FIG. 6A is a cross-sectional view of the wire bar. In FIG. 6A, a wire 62 is attached to a rod 61.
Are in tight contact with each other. 6
3 is a web. FIG. 2B is a schematic diagram showing the amount of application on the wire bar. In the figure, reference numeral 65 denotes a line connecting the vertexes of the convex portions in each cross section of the wire 62, and shows the same state as when the web is in contact with the wire during application. A indicates a hatched space formed between the line 65 and the wire, and the amount of application is defined by A.

FIG. 7 is a sectional view of the wireless bar. FIG. 3A shows a state in which the rods 71 are provided with grooves 72 at a constant pitch. 73 is a web. R indicates the diameter of the wireless bar. FIG. 3B is a schematic diagram showing the application amount in the wireless bar. In the figure, reference numeral 72 denotes a groove provided on the rod 71,
Reference numeral 4 denotes a line connecting the vertices of the convex portions, B denotes a space indicated by oblique lines formed between the line 74 and the groove, and the coating amount is defined by B. W indicates the pitch of the groove, H indicates the rod 71
Indicates the depth of the groove portion, and W and H can be selected according to the viscosity and application amount of the coating solution used in combination with R in FIG.

Generally, the bar used in the present invention is a wire bar in which a wire having a diameter of about 0.025 to 1 mm is densely wound around a rod having an outer diameter of 6 to 25 mm according to the liquid viscosity and the coating film thickness. Bar coating is performed using a wireless bar in which grooves having a depth of about 0.01 to 0.5 mm are formed at a predetermined pitch. The straightness of the bar is an important control item because it affects the accuracy of coating. Therefore, the straightness of the bar needs to be 0.025 mm / m or less. In the case of a wire bar, it is desirable to make it smaller than the minimum wire diameter of 0.025 mm, but in the case of a wireless bar,
More desirably, it is smaller than the minimum groove size of 0.01 mm.

Bar straightness according to the present invention (Method for showing geometrical tolerances, 17.14, 14th edition of Mechanical Design and Drawing Handbook (Rigaku Corporation)
"Depending on the description" means that, in a state in which the bar has no deflection, an arbitrary selected length of 1 m on an arbitrary generatrix of the cylindrical surface connecting the convex portions of the bar surface is 0 mm in a plane including the bar axis. It shows a condition that must be between two parallel straight lines separated by .025 mm.

In the case of the wireless bar used in the present invention, a cross-sectional shape approximating a sinusoidal curve is particularly suitable. However, it is not necessarily limited to such a cross-sectional shape, and other cross-sectional shapes can be used.

Generally, there is a certain correspondence between the wireless bar and the wire bar, and the area per unit of space below the line connecting the peaks of the projections in the cross section (FIGS. 6 (b) and 7 (b)) )) Are equal, it is said that the coating is suitable for applying the same amount of coating under the same conditions. Therefore, based on such a correspondence, an appropriate wireless bar can be selected based on knowledge of the wire bar.

In the case of a wire bar as a bar material, a metal is used for both a rod and a wire constituting the wire bar, and stainless steel is most suitable from the viewpoint of corrosion resistance, abrasion resistance, strength and the like. . This wire can be plated on the surface to further improve the wear resistance. Particularly, hard chrome plating is suitable. The material of the wireless bar is the same as the material of the wire bar.

In the bar coating, the bar is usually placed horizontally to perform the coating. In this case, the bar is bent by its own weight. In order to obtain a coating film thickness with high accuracy, it is preferable to set the deflection amount to 0.3 mm / m or less. For example, even when the rod diameter is 6 mm, the deflection of the bar is 0.3 mm / m.
If it is at most, a good film thickness distribution with a small influence of deflection can be obtained, but it is more preferably at most 0.15 mm / m. In order to reduce the deflection of the bar, it is effective to pull the bar strongly to both ends at the holding parts at both ends of the bar or to support the bar with a holder that is rigid enough to not bend under its own weight It is.

Bar Deflection in the Present Invention (Mechanical Design Drafting Handbook, 9th Edition, 17.14, Method of Demonstrating Geometric Tolerance (Rigaku Corporation)
This means that, in the bar application state, if an arbitrarily selected portion of the bar axis having a length of 1 m is between two parallel straight lines separated by 0.3 mm in a plane including the bar axis. This indicates a state in which it is not necessary.

As described above, in the bar coating of the present invention, the coating amount is defined by the space A between the web and the wire shown in FIG. 6B and the space B shown in FIG. 7B. Therefore, in wire bar coating, variations in the wire diameter directly affect the distribution of the amount of coating liquid remaining on the web after passing through the bar, that is, the film thickness distribution. The relationship is theoretically expressed as Hw = 0.215 × r, where Hw is the film thickness and r is the wire radius. Therefore, since the film thickness is proportional to the wire diameter, it is desirable to make the wire diameter variation equal to or less than the allowable range of the film thickness variation in order to make the film thickness less than the allowable variation. The same can be said for the variation in the cross-sectional area of the groove in the case of using a wireless bar in which the rod is provided with a groove having a constant depth and width. The bar used in the present invention may be rotatable or fixed.

Next, the holder used in the present invention will be described. In bar application, it is common to use a holder as a means for suppressing the deflection of the bar, maintaining linearity, and pressing the bar uniformly over the entire width of the web. By setting the straightness of the holder used to 0.3 mm / m or less, it is possible to reduce the deflection of the bar to 0.3 mm / m or less. By using a holder with a high straightness, when the bar is pressed against the web, the bar will generally bend due to rebound from the web, but with the support of the holder, the deflection can be reduced, and the bar And the scraping amount of the coating liquid is made uniform by the width of the coating.

In the present invention, the straightness of the holder (mechanism design drafting handbook, ninth edition, 17/14, method of showing geometrical tolerance (described by Rigaku Corporation)) means that the surface of the holder close to the bar is perpendicular to this surface. When a cut is made along a plane parallel to the axis of the bar, the arbitrarily chosen 1 m portion of the line that appears on the cut surface is divided between two parallel straight lines 0.3 mm apart in the cut. Indicates a condition that must be met.

As the material of the holder used in the present invention,
It is preferable to use a metal that can be machined with high precision in order to obtain high straightness. In addition, in order to reduce wear of the bar due to contact with the bar, select a material whose hardness is lower than the material used for the bar. There is a need. Resin is a material with low hardness, but if the material of the bar is metal, the wear due to contact is severe, shortening the life of the holder and increasing the frequency of replacement, and the film thickness distribution due to the decrease in straightness due to uneven wear. Deterioration or dust generated by abrasion is not preferable because coating failure occurs. In the present invention, for example, when the bar is made of stainless steel, brass, aluminum, or the like is used.

It is desirable that the gap between the bar and the holder be uniform in order to keep the coating amount constant, but it has been found that setting the gap to 0.1 mm or less does not substantially affect the distribution. If it is 0.1 mm or more, there is a danger that the coating solution will flow to the back side of the bar and be re-applied to the web, and if it is 0.0 mm, the bar and the holder will come into contact with each other and the life will be shortened. When making contact, it is necessary to reduce the contact pressure as much as possible. The gap between the bar and the holder in the present invention refers to the gap between the holder and the virtual cylindrical surface of the bar connecting the apex of the protrusion wound between the wire wound on the rod or the groove on the rod surface.

The holder used in the present invention for adjusting the gap between the bar and the holder has a position adjusting mechanism. The position adjustment of the holder is not limited to the fine screw, but may be any mechanism that can adjust the position. The scale is not limited to the dial gauge and the like, and may be any mechanism that can detect the position. These position adjustment mechanisms (for example, fine screws, position detection scales) facilitate adjustment of the contact strength of the holder with the bar and confirmation of the position. Also,
The parallelism between the bar and the web can be adjusted by making the both ends of the width independent mechanisms.

Since the adjustment of the contact strength of the holder with the bar and the confirmation of the position are facilitated, the contact with the web over the entire length of the bar can be made uniform. Further, the application conditions can be easily reproduced, and when the application is restarted after the application is interrupted, or when another condition is changed by changing the product type, the previous conditions can be easily set, and the application can be smoothly started.

If the moving direction of the holder is almost perpendicular to the web, the moving distance is small and efficient. However, this direction itself does not affect the film thickness distribution, and the contact with the bar can be adjusted. If it is oblique, it does not matter.

Next, the parallelism between the roll and the bar disposed before and after the bar coating apparatus of the present invention will be described. As a result of intensive studies on the parallelism, it is necessary to equalize the lateral tension of the web at the bar portion in order to obtain a highly accurate film thickness distribution. The parallelism between the roll and the bar is 2 mm or less, preferably 1. It has been found that a thickness of 2 mm or less is better for obtaining a highly accurate film thickness distribution. If it is more than 2mm, "Touch" the web
And "wrinkles" occur, which makes it impossible for the bar to maintain uniform contact with the web and to maintain a uniform coating amount. Parallelism in the present invention (How to show geometrical tolerances, 17.14, Mechanical Design and Drafting Handbook, 9th Edition (RIKEN)
Means that the bar axis and the roll axis are 2 mm
Means that it must be between two parallel planes that are only separated.

Next, the straightness of the rolls disposed before and after the bar coating apparatus of the present invention will be described. It has been found that the straightness of the roll is preferably 0.3 mm or less per 1 m of length in order to obtain a highly accurate film thickness distribution, and it is even better to obtain a highly accurate film thickness distribution if it is 0.2 mm or less. When the thickness is 0.3 mm or more, "wrinkling" or "wrinkling" occurs in the web, so that the bar cannot maintain uniform contact with the web and cannot maintain a uniform application amount. or,
Uneven coating amount occurs in the width direction of the web in the roll rotation cycle. The straightness of the roll (refer to the description method of the geometrical tolerance of 17.14 in the Mechanical Design and Drafting Handbook, ninth edition (described by Rigaku Corporation)) refers to an arbitrary base of the roll cylindrical surface in a state where the roll is installed in the coating apparatus. On the line, the part of 1m length arbitrarily selected,
Must be between two parallel straight lines separated by 0.3 mm in the plane containing the roll axis.

Next, the swing of the bar according to the present invention during rotation will be described. When the excess coating solution is scraped off, the bar can be more uniformly scraped off by rotating the bar. Ideally, there is no run-out, but it is impossible to eliminate it completely. It is important to reduce the fluctuation of the gap between the bar and the web in the bar rotation cycle to make the coating uniform, and as a result of examining the allowable range of the shaft runout during the bar rotation, 0.1 mm or less in the direction perpendicular to the axis, It has been found that if the thickness is desirably 0.07 mm or less, there is almost no effect on the film thickness distribution. The swaying is within the scope of the present invention by allowing the straightness and deflection of the bar to fall within the scope of the present invention and by increasing the precision of the motor that rotates the bar.

Next, the flatness of the web at the time of coating according to the present invention will be described. At the time of coating, it is important that the contact between the bar and the web is uniform over the entire length of the bar, which is important for uniformity of the film thickness distribution. The flatness of the web between the rolls before and after the bar is 2 mm, preferably 1 mm or less. Then, it was found that there was almost no effect on the film thickness distribution. In the present invention, the degree of the plane of the web (mechanical design drafting manual, ninth edition, 17.14, the method of showing the geometrical tolerance (described by Rigaku Corporation)) is the degree of deformation of the web between the rolls before and after the bar by 2 mm. Must be between two parallel planes.

The web used in the present invention may be paper,
Plastic film, resin coated paper, synthetic paper,
Any material may be used as long as it can be transported in a belt shape, including metal, cloth, and the like. The material of the plastic film is, 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; polyethylene terephthalate (hereinafter referred to as “PET”); Polyester such as naphthalene dicarboxylate (hereinafter referred to as “PEN”);
A cellulose ester such as polycarbonate, cellulose triacetate (hereinafter, referred to as “TAC”), and cellulose diacetate is used. The resin used for the resin-coated paper is typically a polyolefin such as polyethylene, but is not necessarily limited to this. Among these, PET, PEN, and TAC used as photographic polyester are preferred. Although the effects of the present invention can be obtained with a thin web having a thickness of 5 to 50 μm, a particularly remarkable effect can be obtained with a thick web having a thickness of 75 μm or more. In addition, these webs are disclosed in
Various surface treatments as described in JP 08613 may be applied.

The coating liquid used in the present invention is not particularly limited, and water or an organic solvent liquid of a polymer compound, a pigment dispersion liquid, a colloid solution and the like can be applied. Although it depends on the thickness, the coating speed, the drying speed after coating, etc., the wire streak or the groove streak does not disappear, resulting in a bar streak failure.

Hereinafter, the present invention will be described in detail with reference to examples, but embodiments of the present invention are not limited thereto.

[0057]

EXAMPLES Example 1 Primary film coating; coating speed 1 by extrusion type coating
An excessive amount of the coating solution having the following composition was applied at a width of 1 m at 00 m / min.
After coating on a PET film having a thickness of 100 μm, a diameter of 0.1 μm was applied.
A 33 mm stainless steel wire was wound around an 8 mm stainless steel rod, and the excess liquid was scraped off with a wire bar having changed straightness (described in Table 1) to obtain a final film thickness.
The wire bar was installed at a position about 500 mm downstream of the back roll of the extrusion type coating on the downstream side of the web conveyance, and a support roll was arranged on the back side of the web about 250 mm downstream of the bar coating. After coating and drying and winding up, the sample of the stable coating portion was unwound and used as a sample. The film thickness was measured at 10 locations across the web and the variations were compared. The results are shown in Table 1.

In the measurement of the film thickness (using a mu-checker M-301 manufactured by Mitutoyo Co., Ltd.), after measuring the thickness of the coated web, the coating film of the measured portion was rubbed off with a cotton swab impregnated with acetone. The thickness of only the web at the same location was measured, and the difference was taken as the coating film thickness. The measurement was performed 10 times within a radius of 10 mm at the same location while slightly shifting the location, and the average value was calculated. In addition, the calculation of the film thickness variation% is obtained by calculating the average value of the values at 10 locations in the width direction and expressing the ratio to the average value in%. The calculation formula is shown below.

The film thickness values at the ten widths are represented by t1, t2, t
3,..., T10 Average value of t = (t1 + t2 + t3 +... + T10) /
Variations in straightness of 10 bars were produced in large quantities, and bars with different straightness were selected from among them.

Coating liquid (Carbon dispersion liquid) Carbon black (Raven 1035) 30 parts Barium sulfate (average particle size 300 nm) 10 parts Nitrocellulose 25 parts Polyurethane resin 25 parts (N-2301, manufactured by Nippon Polyurethane Co., Ltd.) Poly Isocyanate compound 10 parts (Nippon Polyurethane Co., Ltd., Coronate L) Cyclohexanone 400 parts Methyl ethyl ketone 250 parts Toluene 250 parts

[0061]

[Table 1]

From the results shown in the table, the straightness is 0.025 mm / m
Above, the variation in the film thickness at the width position is large, but when the straightness is 0.025 mm / m or less, the variation in the film thickness at the width position is small, and when the straightness is 0.01 mm or less, a better result is obtained. The effect of the invention was confirmed.

Example 2 When the sample of Example 1 was applied, the tension of the bar at the holding portions at both ends of the wire bar was adjusted, and various types of application were performed using bars having different flexures (described in Table 2) to produce samples. The film thickness distribution was measured in the same manner as in Example 1 and the variation was shown in Table 2.

[0064]

[Table 2]

From the results in the table, it is found that when the deflection is 0.3 mm / m or more, the variation in the film thickness at the width position is large, but when the deflection is 0.3 mm / m or less, the variation in the film thickness at the width position is small. At 0.15 mm / m or less, even better results were obtained, and the effects of the present invention could be confirmed.

Example 3 When the sample of Example 1 was applied, various samples were prepared using holders having different deflections (described in Table 3), and a wide film thickness was obtained in the same manner as in Example 1. Table 3 shows the results of the distribution measurement.

In addition, the deflection of the holder is manufactured in large quantities,
From these, holders with different deflections were selected and used.

[0068]

[Table 3]

From the results in the table, it is found that when the deflection is 0.3 mm / m or more, the variation in the film thickness at the width position is large, but when the deflection is 0.3 mm / m or less, the variation in the film thickness at the width position is small. At 0.15 mm / m or less, even better results were obtained, and the effects of the present invention could be confirmed.

Example 4 When applying the coating solution of Example 1, a holder having different materials (described in Table 4) was used, and a long (10,0)
00m) A sample was prepared by coating, and a wide film thickness distribution was measured in the same manner as in Example 1. The presence or absence of coating failure was confirmed, and the results are shown in Table 4. Check for coating failure
During the application of 000 m, the coating failure that occurred was visually observed and the results are shown in Table 4.

[0071]

[Table 4]

From the results shown in the table, a metal having a hardness lower than that of the bar has no coating failure, and the film thickness distribution is stable and good. With a holder having the same hardness as the bar (wire), the wire is shaved and the film thickness is reduced after long coating, which is not good. The materials of the holder and the bar (wire) are not limited to those used in this embodiment.

Example 5 When the sample of Example 1 was applied, the variation in the film thickness with and without the hit adjustment mechanism composed of the fine screw of the deflection prevention holder and the scale for position detection was wide. Table 5 shows the results of comparing the adjustment time and the film thickness distribution required for manually preparing a sample within ± 5%. In the same manner as in Example 1, a wide film thickness distribution was measured.

[0074]

[Table 5]

From the results shown in the table, by using the hit adjusting mechanism constituted by the fine screw and the position detecting scale of the present invention, a good film thickness distribution can be obtained in a short bar adjusting time, and the effect of the present invention is confirmed. done.

Example 6 When the sample of Example 1 was applied, the gap between the holder and the surface of the bar convex portion was variously changed by the hit adjustment mechanism composed of the fine screw and the position detecting scale used in Example 5 (see Table 1). 6) The film thickness distribution was measured in the same manner as in Example 1 and the variation was shown in Table 6.

[0077]

[Table 6]

From the results shown in the table, when the gap between the holder and the surface of the bar convex portion is set to 0 to 0.1 mm or more, the dispersion of the film thickness is large. The effect of the present invention was confirmed. The result was the same even when the wire bar was changed to a wireless bar.

Example 7 When applying the sample of Example 1, before winding the wire around the rod, the variation in the wire diameter was measured by an electric microgauge (Mu-Checker M-301 manufactured by Mitutoyo Corporation). After preparing a wire bar with wires having different variations (described in Table 7), applying the same, and measuring the film thickness distribution over a wide area by the same method as in Example 1, the results of the variations are shown in Table 7.
The wire diameter variation% was determined by measuring the diameter of the wire before winding the bar at 25 points at intervals of 10 mm, and calculating the% of the maximum-minimum average value.

[0080]

[Table 7]

From the results shown in the table, the variation ratio of the wire diameter almost coincides with the variation ratio of the film thickness in the width direction. It was found that the ratio should be within the range, and the effect of the present invention could be confirmed. In particular, in order to obtain a film thickness distribution of 5% or less at the maximum and minimum, the variation in the wire diameter is preferably less than 5%, more preferably 3% or less.

Example 8 When applying the sample of Example 1, instead of using a wire bar, a wireless bar in which a triangular groove having a depth of 0.22 mm and a width of 0.44 mm was spirally dug was used. Was measured with a contour shape measuring device (Contour Record 2600B, manufactured by Tokyo Seimitsu Co., Ltd.), applied, and the thickness distribution was measured by the same method as in Example 1. Table 8 shows the variation results.

[0083]

[Table 8]

From the results shown in the table, the variation ratio of the cross-sectional area of the groove almost coincides with the variation ratio of the wide film thickness, and in order to keep the wide film thickness within the allowable range, the variation ratio of the cross-sectional area must be reduced. It was found that the thickness should be within the thickness variation ratio, and the effect of the present invention could be confirmed. Especially 5% for max to min
In order to achieve the following film thickness distribution, the variation in the groove cross-sectional area is preferably less than 5%, and more preferably 3% or less.

Example 9 When the sample of Example 1 was applied, one position of the both ends holding portion of the bar was moved in the vertical direction of the web, and the parallelism with the rolls before and after the bar was variously changed (Table 9). ), Applied to a web with good flatness, and measured the thickness distribution over a wide area by the same method as in Example 1. The results of the dispersion are shown in Table 9.

[0086]

[Table 9]

From the results shown in the table, when the parallelism of the roll is 2 mm or more, the film thickness variation is large, but when the parallelism is 2 mm or less, it becomes small, and when the parallelism is 1.2 mm or less, the film thickness distribution is affected. Was found to be almost absent, and the effect of the present invention was confirmed.

Example 10 When the sample of Example 1 was applied, a roll having different straightness (described in Table 10) was used before and after the bar, and the sample was applied to a web having good flatness. The film thickness distribution in the width direction was measured in the same manner, and the variation results are shown in Table 10.

[0089]

[Table 10]

From the results shown in the table, the straightness of the roll is 1 m in length.
When the straightness is 0.3 mm or more, the variation in the film thickness is large, but the straightness decreases when the straightness is 0.3 mm or less per 1 m of the length, and when the straightness is 0.2 mm or less, the film thickness distribution is hardly affected. This proved the effect of the present invention.

Example 11 When the sample of Example 1 was applied, the bar was rotated forward in the transport direction using a bar rotating mechanism with the center of the cross section of the bar as an axis.
The film was rotated at pm, and the coating was repeatedly performed while correcting the axial runout (described in Table 11) to improve the film thickness distribution in the transport direction. After the completion of the coating, the film thickness distribution in the transport direction was measured by the same method as in Example 1, and the variation results are shown in Table 11.

[0092]

[Table 11]

From the results shown in the table, when the axial runout of the rotation of the bar is 0.1 mm or more in the direction perpendicular to the axis, the variation in the film thickness is large, but when it is 0.1 mm or less, it becomes small, and the straightness is 0.07 mm or less. Then, it was found that there was almost no effect on the film thickness distribution, and the effect of the present invention could be confirmed.

Example 12 When the sample of Example 1 was applied, it was applied using various PET bases (described in Table 12) having different thicknesses and flatnesses.
Wide film thickness distribution was measured in the same manner as in Example 1, and the variation results are shown in Table 12.

[0095]

[Table 12]

According to the results shown in the table, the distance between the rolls before and after the bar was 2 m.
m or less, desirably 1 mm or less, there is almost no effect on the film thickness distribution. Although a thin web having a thickness of 5 to 50 μm can be obtained, it is particularly remarkable in a thick web having a thickness of 75 μm or more, and the effect of the present invention was confirmed.

[0097]

According to the present invention, a continuously conveyed web is provided.
In the method of applying using a bar, in order to make the contact with the web over the entire length of the bar uniform, the straightness of the bar, the amount of deflection, and the gap between the bar and the web are defined so that the coating solution scraping is performed. The width was made uniform, and the film thickness after passing through the bar was made uniform.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a bar coating (inclined coating) of the present invention.

FIG. 2 is an enlarged schematic view of a bar coating device used in the tilt coating according to the present invention.

FIG. 3 is a schematic view of a bar coating apparatus used in bar coating (horizontal coating) of the present invention.

FIG. 4 is a schematic diagram of a holder position adjusting mechanism and a bar front-back movement used in the present invention.

FIG. 5 is a schematic side view of a bar coating device used in the present invention as viewed from the side.

FIG. 6 is a schematic view showing a cross-sectional view of a wire bar used in the present invention and an application amount.

FIG. 7 is a cross-sectional view of a wireless bar used in the present invention and a schematic diagram showing an application amount.

[Explanation of symbols]

1, 31 bar coating device 2, 2 ', 32, 32' roll 3, 33, 63, 73 web 4 coating device 8, 37 bar 9, 39 holder portion 10, 40 outer cylinder portion 11, 38 fine screw 12 measuring device 13 Mounting jig 14, 41 Mounting base 15, 42 Cylinder 16 Bar holding unit 17 Tension adjusting unit 18 Motor 61, 71 Rod 62, Wire 65 Line connecting the top of the wire A Between the line connecting the top of the wire and the wire Available space 72 Groove 74 Line connecting the vertices of the protrusions B Space formed between the line connecting the vertices of the protrusions and the grooves W Pitch between grooves H Height of grooves R Bar diameter

Claims (18)

[Claims] 1. A coating apparatus for coating a continuously conveyed belt-shaped support using a bar, wherein the straightness of the bar is 0.025 mm or less per 1 m of the bar length. apparatus. 2. A coating apparatus for coating a continuously conveyed belt-shaped support using a bar, wherein the deflection of the bar is 0.3 mm or less per 1 m of bar length. . 3. A coating apparatus for applying a bar to a continuously conveyed belt-like support using a bar, wherein a holder for preventing deflection of the bar is provided on a side of the bar opposite to the band-like support, and a straightness of the holder is provided. Is 0.3mm per 1m of holder length
A bar coating device characterized by the following. 4. The bar coating apparatus according to claim 3, wherein the deflection preventing holder is formed of a metal having a lower hardness than an outermost peripheral surface of the bar. 5. The bar coating apparatus according to claim 3, wherein the deflection preventing holder has an adjusting mechanism that enables uniform adjustment of the contact with the bar. 6. A mechanism capable of moving the holder position at least at two or more positions in the width direction of the band-shaped support member in a direction at least substantially perpendicular to the band-shaped support member with the bar interposed therebetween, and position detection. 6. A bar coating apparatus according to claim 5, further comprising a mechanism capable of performing the above operation. 7. A coating apparatus for applying a bar to a continuously transported band-shaped support using a bar, wherein a bar for preventing the bar from being bent is provided on a side of the bar opposite to the band-shaped support.
The gap between the bar convex surface and the holder is 0 to 0.1 mm.
A coating method characterized by adjusting the thickness of the coating solution. 8. The bar according to claim 1, wherein the bar is a wire bar in which a wire is wound around a rod or a wireless bar in which a groove having a predetermined depth and width is provided in the rod.
7. The bar coating device according to 2, 3, 4, 5, or 6. 9. The coating method according to claim 7, wherein the bar is a wire bar in which a wire is wound around a rod or a wireless bar in which a rod having a predetermined depth and width is provided. 10. A wire bar coating apparatus for coating a continuously conveyed belt-shaped support using a bar around which a wire is wound around a rod, wherein the wire is wound over the entire length of the wire wound around the rod. A bar coating apparatus characterized in that the variation of the cross-sectional area is within the allowable range of the variation of the film thickness in the width direction. 11. A wireless bar coating apparatus for coating a continuously conveyed belt-shaped support using a bar provided with a groove having a predetermined depth and width on a rod, wherein the variation of the cross-sectional area of the groove is reduced by the width. A bar coating apparatus characterized in that the thickness of the hand is kept within an allowable range. 12. A coating apparatus for applying a bar to a continuously conveyed belt-like support using a bar, wherein a parallelism of the conveying roll of the band-like support provided immediately before and after the bar with the bar is provided. Is 2 mm or less per 1 m of the roll length. 13. A coating apparatus for coating a continuously conveyed belt-like support using a bar, wherein the straightness of a conveying roll of the band-like support provided immediately before and immediately after the bar is equal to the roll. A bar coating device having a length of 0.3 mm or less per 1 m of length. 14. A coating apparatus for coating a continuously conveyed belt-like support using a bar, wherein the bar is rotatable around a center of a cross section of the bar, and the rotation of the bar is perpendicular to the axis. A bar coating device characterized by being 0.1 mm or less in a direction. 15. A coating method for coating a continuously conveyed belt-shaped support using a bar, wherein the flatness of the band-shaped support is applied between rolls before and after the bar at 2 mm or less. Coating method. 16. A coating method for applying a bar to a continuously conveyed belt-shaped support using a bar, wherein the bar has a straightness of not more than 0.025 mm per 1 m of the bar length, and has a straightness of not more than 0.025 mm. A bar for preventing deflection of the bar that is 0.3 mm or less per 1 m in length is provided on the opposite side of the bar-shaped support of the bar, and the holder position is set at least in a direction substantially perpendicular to the band-shaped support across the bar. By the adjustment mechanism of the holder which can be moved and the position can be detected, the deflection of the bar is 0.3 mm per 1 m of the bar length.
Hereinafter, the gap between the bar and the holder is 0 to 0.1 mm.
A coating method characterized in that the coating is carried out by adjusting the temperature. 17. The method according to claim 1, wherein the thickness of the belt-shaped support is 75 μm or more.
The bar coating apparatus according to 6, 8, 10, 11, 12, 13, or 14. 18. The coating method according to claim 7, wherein the thickness of the belt-shaped support is 75 μm or more.