JP2003126766A - Coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a remarkably thin coating layer of a scraping type and simultaneously to remarkably decrease the thickness distribution of the coating layer in width the direction of a supporting body. SOLUTION: In a coating method by which a coating liquid in the quantity more than required is applied on a continuously traveling belt like web 12 by a pre-coat apparatus 14 and the excess portion of the coating liquid is scraped with a scraping member 16 by giving relative pressing force to the web 12 and the scraping member 16, the coating thickness distribution in the web width direction before the excess portion of coating liquid is scraped by the scraping member 16 is controlled to <=20%.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating method, and particularly
In addition, it is used in the manufacture of photographic light-sensitive materials and magnetic recording media.
Scrape off the excess amount of the applied liquid with a scraping member.
Post-weighing type application to scrape and weigh to desired application amount
Regarding the method. [0002] Photosensitive materials and magnetic recording media are continuously run.
A flexible belt-like support (hereinafter referred to as “web”)
Apply a predetermined coating liquid such as magnetic liquid on top of the coating film
It is manufactured through a coating process to be formed. In particular, magnetic recording tape
Magnetic recording media such as loops are intended for broadcasting and computers.
The capacity and recording density are improving rapidly, and the film thickness is thin.
In addition, a coating technique that can obtain a magnetic layer with a smooth surface
It has been demanded. As a method of applying a coating solution to a web surface
For example, roll coater method, gravure coat method,
Le Coat plus doctor method, extrusion coating
Method, slide coating type coating method and the like. Among the extrusion type coating methods,
As shown in Japanese Patent Publication No. 5-8065, the tip of the coating head
With a coating method that presses the web against the web,
To increase the fluid pressure at the tip of the coating head
Eliminates the air entrained by the web
Since a uniform coating layer can be obtained, the production of magnetic recording media
In the field of construction. However, this type of extrusion
Possible coating layer thickness even when applying by mold application method
Demands to obtain a thin magnetic layer
There is a problem that cannot be answered sufficiently. Furthermore, application
A streak occurs in the coating layer due to web scraping at the head tip.
There is a drawback that it is easy to do. [0006] From this, it is thinner and coating without stripes.
As a coating method capable of obtaining a fabric layer, Patent No. 261 is used.
Doctor blade scraping shown in No. 4119
There are mold application methods. This coating method is a roll coater type
Apply the excess coating solution on the web with
Excessive coating solution with a doctor blade located downstream
A thin coating layer is obtained by scraping off the minutes.
The In this case, in Japanese Patent No. 2614119,
As a pre-coating device for applying excess coating liquid
Is using a roll coater type, but this is not necessary
Without support pressure extrusion type, backup
Extrusion type, gravure slide coater type
Etc. can be used. [0007] However, the prior art
The application method of scraping with a doctor blade is thin.
A coating layer without coating streaks can be obtained,
-Web width direction of the coating layer after scraping with a blade
However, there is a drawback that a coating thickness distribution tends to occur. This paint
The degree of cloth thickness distribution is necessary for the magnetic layer of conventional magnetic recording media.
In the case of the required coating layer thickness,
The thickness of the magnetic layer of recent magnetic recording media
In an extremely wet state, it has been made extremely thin, less than 2μm.
It is manifested by this. Therefore, the doctor
In the web width direction of the coating layer after scraping with a blade
Pursuing the cause of the occurrence of coating thickness distribution and eliminating the cause
It is necessary to remove. The present invention has been made in view of such circumstances.
When you get a very thin coating layer of scraping type
While maintaining the features, the thickness of the coating layer in the width direction of the support
To provide a coating method that can significantly reduce the size of a cloth.
For the purpose. [0009] The present invention achieves the above object.
In order to achieve this, the belt-like support
Excessive amount of coating liquid on the support with a coating device
After applying the coating solution, scrape the application side of the support
The over-coated coating
Application method of scraping off excess liquid with the scraping member
In the method, the excess of the coating solution is scraped off with the scraping member.
20% coating thickness distribution in the width direction of the support before scraping
It is characterized by the following. As in the present invention, the pre-coating apparatus is
After applying excess, scrape off the excess with a member.
After the final coating layer is formed
The final coating thickness and thickness distribution in the width direction of the support
Is determined by the quality of scraping with scraping members
Research on scraping technology has been
Has been made. However, the inventor has determined that the final coating layer thickness
Scraping part
The quality of scraping with wood can have a big impact
Other than that, the width of the support before scraping
The coating thickness distribution in the direction is the final coating layer support after scraping.
Acquired knowledge that it greatly affects the thickness distribution in the width direction of the holder
It was. In particular, 2 μm in a wet state as in recent magnetic recording media.
When forming an unprecedented extremely thin magnetic layer of m or less,
The effect of coating thickness distribution in the width direction of the substrate before scraping is evident.
It is materialized. The present invention has been made based on such knowledge.
Excessive coating liquid that has been overcoated with a precoater
Paint in the width direction of the support before scraping off with the scraping member
The cloth thickness distribution was set to 20% or less. This
Scraping type suitable for obtaining an extremely thin coating layer
Supporting the final coating layer while maintaining the characteristics of the coating method
The thickness distribution in the body width direction can also be significantly reduced.
Therefore, it is possible to obtain a very thin magnetic layer of 2 μm or less in a wet state.
This is particularly effective as a cloth method. The scratches used here
As a scraping member, doctor blade or rod
(Flat rod, wire rod, grooved rod)
It can be preferably used. Also, coating in the width direction of the support before scraping off.
As a method of reducing the thickness distribution to 20% or less, pre-coating
A method for providing a coating thickness distribution adjusting function in the apparatus itself,
Those who have a function to adjust the coating thickness distribution separately from the coater
Any of the methods may be used. The coating thickness in the width direction of the support before scraping off
As a preferable aspect of adjusting the cloth, a precoat device and
Support pressure extrusion type or back-up
Has a slit like an extrusion type
To adjust the slit gap amount
The method can be suitably used. In this case, support pressurization
For the extrusion type, upstream and downstream of the coating head
By tilting the support roller provided on the side,
The cloth thickness distribution can also be adjusted. In addition, support
-You can use both the inclination of the roller and the adjustment of the gap of the slit.
Yes. In short, the width of the support before scraping with a scraping member
Method that can reduce the coating thickness distribution in the direction to 20% or less
If it is. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings.
A preferred embodiment of the coating method will be described in detail. A coating apparatus to which the coating method of the present invention is applied is as follows:
Mainly, the web 12 is coated in excess of the desired amount of coating solution.
Pre-coating device 14 for applying cloth liquid, and excessive application
Scraping member (app)
And the web 12 is pushed against the scraping member 16.
Support rollers 18 and 18 for applying pressure by sticking
And scraping off the excess of the coating liquid with the scraping member 16
For coating thickness to adjust the coating thickness distribution in the previous web width direction
It is comprised with the cloth adjustment apparatus 20. FIG. The coating apparatus 10 shown in FIG.
Extrusion type coating with backup as 4
Use the head 22 to scrape off the excess coating liquid.
Using a doctor blade 17 as a member 16 and coating
Slit of coating head 22 as thickness distribution adjusting device 20
Slit-adjustable coating thickness distribution adjustment device that adjusts the gap amount
It is configured using the device 20. Extrusion type with backup
In this case, it is close to the lip surface 24 at the tip of the coating head 22.
The backup roller 26 that supports the web 12 is opposite.
Be placed. Inside the coating head 22 is the web 12.
When the cylindrical pocket portion 28 is formed along the width direction
In addition, a slit from the pocket portion 28 to the lip surface 24
30 is formed. The slit 30 has a pocket portion 28 and
It is a narrow flow path connecting the lip surface 24 and the web 12
It is extended in the width direction. Then, the pocket of the coating head 22 is
The coating solution supplied to the groove portion 28 is wetted by the pocket portion 28.
After being expanded in the width direction, the slit 30 is
Discharged from the outlet. The discharged coating liquid
Continuously supported by the back surface 24 and the backup roller 26
While forming a bead with the traveling web 12, the web
Applied to the base 12. In addition, the coating liquid is sent to the pocket portion 28.
As a liquid method, the other end side of the pocket portion 28 is closed.
Supply from one side, either side of the pocket 28
And then pulling out from the other end side of the pocket 28
Use any of the methods of supplying from the center and diverting to both sides
May be. The doctor blade 17 is used to run the web 12.
Arranged so as to be approximately perpendicular to the row direction,
On the upstream and downstream sides of the web travel direction, with raid 17 as the boundary
A pair of support rollers 18, 18 are provided. This one
The pair of support rollers 18 is located at the tip of the doctor blade 17.
It is arranged at a position lower than the end. This allows continuous running
The web 12 is applied to the distal end surface 32 of the doctor blade 17.
Of the coating liquid pressed and excessively applied to the web 12
The excess is scraped off by the doctor blade 17.
The distal end surface 3 of the doctor blade 17 facing the web 12
2 is curved with a curvature R of 1 to 30 mm as shown in FIG.
The web 12 is incident on the distal end surface 32 at an incident angle (θ
_in ) Invade while wrapped in a range of 0.5-2 °,
Separation angle (θ _out ) As appropriate. This allows the Doc
The clearance between the tip end surface 32 of the terblade 17 and the web 12
Since it is possible to keep it below 2 μm,
The coating layer thickness after being scraped off by the lade 17 is wet.
The thickness can be reduced to 2 μm or less. Doctor
The blade 17 can be, for example, a superalloy or a fine ceramic.
Cus, alumina A-150, hard body such as zirconia,
Consists of a member whose surface is covered with these materials
And its surface is R _max 0.5μm or less is preferable
Or surface processed with a roughness of 0.2 μm or less. Slit adjustment type coating thickness distribution adjusting device 2
As shown in FIG. 3, the zero is mainly the yoke 34 and the
Biasing screw 36 and fulcrum screw 3 attached to the yoke 34
8 and a fixing screw 40. The yoke 34 is shown in FIG.
Overhang from the outer wall surface of the coating head 22 as shown in FIG.
Action that is attached and closest to the tip 42 of the application head 22
In the portion 44, the fixing head 40 is used to fix the coating head 22 to
It has been determined. Further, the urging portion farthest from the distal end portion 42
46 is provided with a biasing screw 36 and an action portion 44.
The fulcrum part 48 in the middle position between the urging part 46 and the urging part 46 is a fulcrum screw 38.
Supported by Then, the application head 22 of the urging screw 36.
Applying force to the action part 44 by adjusting the screwing amount with respect to
Thus, the opening width t of the slit 30 is adjusted. Example
For example, the biasing portion 46 is adjusted by adjusting the screwing amount of the biasing screw 36.
To approach the outer wall surface of the coating head 22 (in the direction of arrow A)
The lever principle works with the fulcrum 48 as a fulcrum.
Therefore, a force in the direction of arrow B is applied to the action portion 44. this
The block that configures the coating head 22 so that it can be divided
Of 22A and 22B, the bush to which the yoke 34 is attached
The portion near the tip of the lock 22A is pulled in the direction of arrow B
Accordingly, the tip 42 is in a direction according to the arrow B direction.
Move in the direction of arrow C. As a result, the slit 30
The opening width t is widened. Therefore, the outer wall of the coating head 22
Distributing thickness distribution at the left and right ends and the center of the surface
By adjusting the adjusting device 20 individually, the slit width
Adjust the gap distribution in the (L) direction (same as the web width direction)
can do. Thereby, the doctor blade 17
Apply in the web width direction before scraping off excess liquid with
Adjust the thickness distribution. The coating apparatus 50 shown in FIG.
4 as a support pressure extrusion type coating head
52, scraping off the excess of coating liquid
Coating thickness distribution adjusting device using rod 54 as material 16
20, support on the upstream side and downstream side of the coating head 52
Support for inclining at least one of the rollers 18
A troller inclined coating thickness distribution adjusting device 56 is used.
Made. In addition, the precoat apparatus 1 of FIG. 1 and FIG.
4 scraping members 17 and 54 are replaced.
It is also possible to do. The support pressure extrusion type of FIG.
In this case, it is supplied into the pocket portion 28 of the coating head 52.
Slit 30 for communicating the applied coating liquid to the pocket portion 28
It is mounted on the support roller 18 from the discharge port 30A.
Push the web 12 running in the direction of the arrow against the head end face 58.
Discharge continuously while sticking. As a result, the web 1
2 of the coating liquid formed between the head 2 and the head end face 58.
An excessive coating solution is applied to the web 12 via the web.
Excessive coating liquid is a rod-shaped scraping member
16 is scraped off. The rod-shaped scraping member 16 is made of a web.
A cylindrical rod 54 arranged in parallel with the width direction of 12
It is configured to be supported by a rod support member 57, and a support row
La 18 causes the traveling web 12 to move against the rod 54.
And contact with a predetermined wrap angle. As a result,
Excessive coating was applied to the web 12 by the recoating device 14.
The excess coating solution is scraped off by the rod 54.
Weigh to the desired amount of coating solution. In this case, the rod 54 is
By contacting the web 12, it is the same as the traveling direction of the web 12.
May rotate in the direction,
May be. Further, a rotational drive source (not shown) is connected to the rod 54.
)) And rotate in the direction opposite to the running direction of the web 12
You may make it do. The rod 54 used here and
Flat rods with a flat rod surface,
Wire rod, rod base material in which a wire is wound tightly around a wire
Use a grooved rod with grooves in the circumferential direction of the surface.
be able to. In addition, the rod 54 removes excess coating liquid.
Polishing contained in the coating liquid when scraping off the web 12
Contact with inorganic particles such as agents promotes wear on the rod surface
Therefore, Vickers hardness (H
_v ) Is not less than 1000, preferably not less than 2000
Are preferred. Doctor with flat rod
It is possible to use cemented carbide as well as the blade.
In this case, the surface roughness is R _max 0.5 μm or less, preferably
Is preferably surface processed with a roughness of 0.2 μm or less
Yes. The rod 54 has a diameter of 1 mm to 20 mm.
Although many are used, it is not particularly limited. Adjustment of coating thickness distribution of support roller tilt type
As shown in FIGS. 5 and 6, the device 56 is precoated.
Support rollers disposed on the upstream side and the downstream side of the device 14
Tilt at least one of 18 in the web width direction
To adjust the coating thickness distribution in the web width direction during coating.
It is something to be arranged. Tilt to tilt the support roller 18
An example of the tilt mechanism is shown in FIG. As shown in FIG. 7, both support rollers 18
End rotary shafts 60 and 60 are supported by bearings 62 and 62, respectively.
The bearings 62 and 62 are respectively universal joysticks.
Supported by the nut members 70, 70 through the nuts 66, 66.
It is. Each of the nut members 70 and 70 is not shown in the drawing.
It is supported by the id member so as to be slidable in the Y-axis direction.
In addition, the nut members 70, 70 are arranged in the Y-axis direction.
The Y-axis feed screw 64 is screwed. Y-axis feed screw
At the base end of 64, there is a motor 7 with a built-in speed reducer that can rotate forward and reverse.
2 are connected, and this motor 72 is driven.
Therefore, the Y-axis feed screw 64 rotates. This makes a pair
The Y-axis feed screw 64 has different feed screw amounts.
The support roller 18 is broken from the solid line state of FIG.
Inclined like a state. Therefore, the coating head 52 and the support
The web width direction that presses the web 12 with the trawler 18 is
Since a pressing force distribution is generated, the web is applied from the coating head 22.
12 to adjust the coating thickness distribution in the web width direction.
I can. FIG. 6 shows the upstream side and the lower side of the coating head 52.
Tilt the support rollers 18 on the flow side to be opposite to each other
This is the case when it is skewed. Motors 72, 72 are attached to both ends of the moving body 68.
The moving body 68 is fixed under the suspension member 74.
Linear bearings on rails 76 arranged in the X-axis direction on the surface
It is suspended so as to be slidable through the groove 78. Also move
The body 68 is screwed onto the X-axis feed screw 80 disposed in the X-axis direction.
Combined. The base end of the X-axis feed screw 80 is not shown.
A motor with a built-in decelerator that can rotate forward and reverse is connected.
By driving this motor, the X-axis feed screw 8
0 rotates and the moving body 68 moves in the X-axis direction. to this
Accordingly, the support roller 18 moves in the X-axis direction in FIG.
The Support roller by the pair of Y-axis feed screws 64
18 Y-axis tilt and support by X-axis feed screw 80
As the roller 18 moves in the X-axis direction, the web width direction
Finely adjust the coating thickness distribution. In addition, support
The tilting mechanism of the roller 18 is limited to the mechanism described above.
The tilt angle of the support roller 18 is finely adjusted.
Other mechanisms may be used as long as they can be adjusted. Y axis
Use both feed screw 64 and X-axis feed screw 80
It is not limited to this, it is applied only with the Y-axis feed screw 64
You may adjust cloth thickness distribution. In addition, the roller used for the roller inclined type described above.
If an expander roller is used as the roller,
Inclined in a curved line rather than in a straight line in the width direction.
You can. As a result, from one end of the web width direction to the other
A curved pressure, not a linear pressure distribution on the edge
The force distribution can be adjusted. Therefore, the width of the web
The coating thickness distribution can be adjusted in a curved direction. The coating apparatus 1 of the present invention constructed as described above.
0, 50, the precoater 14 itself or the precoater 14
Apart from the coating device 14, the coating thickness distribution adjusting device 20, 5
6 is provided, so that an excessive coating liquid is applied by the scraping member 16.
Adjust the coating thickness distribution in the web width direction before scraping off
Can. In the present invention, this coating thickness
Using the cloth adjusting devices 20 and 56, the scraping member 16
Coating thickness in the web width direction before scraping off excess liquid
The distribution is adjusted to 20% or less. This
Scraping-off type coating to obtain a very thin coating layer
Web width of the final coating layer while maintaining the characteristics of the device
The thickness distribution in the direction can also be significantly reduced. Follow
2 μm or less in a wet state as in recent magnetic recording media
As a coating method to obtain an extremely thin magnetic layer
It is effective for. [Example] The excess of the coating solution is scraped off with a scraping member.
Application thickness distribution in the web width direction before scraping
The thickness of the final coated layer after scraping with
Explains the results of a test that investigated how this affects the distribution
To do. (Test 1 ... Example 1 and Comparative Example 1) As a precoat device
Fig. 8 shows a scraping member using a gravure coater.
The radius of curvature of the tip surface is R4mm and the blade thickness is 1.5.
A mm doctor blade was used. Application condition is thickness 1
PET (polyethylene terf
Apply the coating liquid A shown in Table 1 to the web of the talate material.
The precoat coating thickness is 20 μm at a speed of 100 m / min.
Then apply the solution with a doctor blade.
Scrape off the excess and wet the final film thickness
It was set to 2 μm. And by precoat application
Thickness distribution in the web width direction (hereinafter referred to as “precoat”)
"Dispensing thickness distribution") and scraping with a doctor blade
Thickness distribution in the web width direction of the final coating layer after
"Final film thickness distribution" below)
Measured with a thickness distribution measuring instrument.
The difference between the maximum value and minimum value is divided by the average thickness.
("Range%"). The gravure coater of Example 1 in Table 4
The coating application thickness distribution was adjusted to 20% or less.
The gravure coater of Comparative Example 1 is pre-coated.
Use a coating thickness distribution adjusted to exceed 20%.
I used it. (Test 2 ... Examples 2 to 4 and Comparative Examples 2 and 3) Pre-coating
Extrusion-type application with backup
Use the head (shown as “backup die” in Table 4)
The radius of curvature of the tip surface shown in FIG. 9 as a scraping member
Doctor blur with R1mm and blade thickness of 0.3mm
Used. The coating conditions are 10 μm thick and 1000 mm wide.
mm PEN (polyethylene naphthalate) material
The coating liquid A shown in Table 1 is applied at a coating speed of 200 m / min.
Apply the coating to a thickness of 30 μm, then continue
Use a doctor blade to scrape off the excess coating solution.
The final film thickness should be 1 μm by wet (wet condition)
It was. And the web width of the coating layer by pre-coating
Thickness distribution (hereinafter referred to as “precoat coating thickness distribution”)
U) and the final coating after scraping with a doctor blade
The thickness distribution in the web width direction of the fabric layer (hereinafter referred to as “the final film thickness
Light transmission type on-line thickness distribution measuring instrument
Measure each thickness distribution (maximum and minimum thickness)
"Range%" which is the value obtained by dividing the difference with the average value)
It was. Examples 2 to 4 in Table 4 are coating thickness distribution adjustments.
The precoat coating thickness distribution is 20% or less depending on the device.
Comparative Example 2 by adjusting the slit gap amount of the coating head
And 3 so that the precoat coating thickness distribution exceeds 20%
The slit gap amount is adjusted. (Test 3 ... Examples 5-7 and Comparative Example 4) Pre-coating apparatus
Support pressure extrusion type coating head (table
4 is described as “Pressure type die”), scraping member
As shown in FIG.
The angle formed by the plane a and the downstream plane b is 155 °,
A doctor blade with a blade thickness of 4 mm was used. Painting
The cloth condition is 4 μm thick and 300 mm wide aramid material.
On the web, the coating liquid A shown in Table 1 was applied at a coating speed of 400 m / min.
And apply so that the precoat coating thickness is 10 μm,
Next, the doctor blade is used to scrape off the excess liquid.
The final film thickness becomes 0.5 μm when wet (wet condition).
I did it. Then, the coating layer is coated by pre-coating.
Thickness distribution in the width direction (hereinafter referred to as “precoat coating thickness
Cloth ”) and after the scraping with a doctor blade
The thickness distribution in the web width direction of the final coating layer (hereinafter referred to as “final film”
"Thickness distribution") and light transmission type online thickness distribution
Measured with a measuring instrument, each thickness distribution (maximum thickness and
“Range%”, which is the difference from the minimum value divided by the average value)
I investigated. Examples 5 to 7 in Table 4 are coating thickness distribution adjustments.
The precoat coating thickness distribution is 20% or less depending on the device.
Comparative Example 4 by adjusting the slit gap amount of the coating head
Use a slit so that the precoat coating thickness distribution exceeds 20%.
The amount of gap between the holes is adjusted. (Test 4 ... Examples 8 to 10 and Comparative Example 5) Pre-coating apparatus
As a support pressure extrusion type coating head
Scraping member using pressure die (shown in Table 4)
As shown in FIG. 11, the upstream side surface in the web running direction of the tip surface
The radius of curvature of a is 0.5mm and the radius of curvature of the downstream side b is
Doctor with R10mm and blade thickness of 2mm
-A blade was used. The coating conditions were 5 μm thick and 10 width wide.
00mm PEN (polyethylene naphthalate)
On the surface, the coating solution B shown in Table 2 in advance is a dry film with a thickness of 2 μm.
The coating liquid C shown in Table 3 is further added to the web coated on
Precoat coating thickness is 10 μm at a coating speed of 400 m / min
Then, apply with a doctor blade.
The final film thickness is wetted (wet)
In the state), the thickness is 0.5 μm. And Precor
Thickness distribution in the web width direction of the coating layer (
"Precoat coating thickness distribution") and doctor brace
Of the final coated layer after scraping
The thickness distribution (hereinafter referred to as “final film thickness distribution”)
Each thickness measured with an over-type online thickness distribution measuring instrument
Distribution (the difference between the maximum and minimum thickness divided by the average value)
The value “range%”) was examined. Examples 8 to 10 in Table 4 are coating thickness distribution adjustments.
The precoat coating thickness distribution should be 20% or less
Comparative example of adjusting the slit gap amount of the coating head so that
No. 5 so that the precoat coating thickness distribution exceeds 20%.
The lit gap amount is adjusted. (Test 5: Example 11 and Comparative Example 6) Pre-coating apparatus
Supporting pressure extrusion type coating head (Table 4)
Is used as a scraping member.
A carbide flat rod with a diameter of 2 mm was used. Coating strip
The application condition is PE with a thickness of 5 μm and a width of 1000 mm.
N (polyethylene naphthalate)
The coating solution B shown in Fig. 2 is applied in a dry film to a thickness of 2 µm.
The coating liquid C shown in Table 3 is further applied to the web with a coating speed of 400.
Apply so that the precoat coating thickness is 20 μm at m / min.
And then scrape off the excess liquid with a flat rod.
As a final film thickness of 0.8μm wet (wet state)
It was made to become. And the coating layer by pre-coating
Thickness distribution in the web width direction (hereinafter referred to as “precoat coating thickness”)
Distribution)) and after the scraping with a flat rod
The thickness distribution in the web width direction of the final coating layer (hereinafter referred to as “final film”
"Thickness distribution") and light transmission type online thickness distribution
Measured with a measuring instrument, each thickness distribution (maximum thickness and
“Range%”, which is the difference from the minimum value divided by the average value)
I investigated. Example 11 in Table 4 shows a coating thickness distribution adjusting device.
The precoat coating thickness distribution will be 20% or less
The slit gap amount of the coating head was adjusted, and Comparative Example 6
Slip so that the precoat coating thickness distribution exceeds 20%.
The gap amount is adjusted. [Table 1] [Table 2] [Table 3] For each of the coating liquids in Tables 1 to 3, the components are
After kneading with a sand, disperse for 4 hours using a sand mill
10 parts by weight of polyisocyanate was added to the resulting dispersion.
In addition, add 40 parts by weight of cyclohexane and add 1 μm
Prepared by filtering through a filter with an average pore size
did. The results of Test 1 to Test 5 are shown in Table 4. table
Among the four items, the evaluation criteria for “determination” are generally
If the final film thickness distribution is 10% or less, there is no practical problem.
The results of 10% or less are indicated by ○ which is a pass, and 10
Results exceeding% are indicated by an unacceptable x. [Table 4] As can be seen from the results in Table 4, the coating liquid is applied with a scraping member.
Precoat application in the web width direction before scraping off excess
Examples 1 to 11 of the present invention in which the cloth thickness distribution is 20% or less
In the case of
Regardless of the type, the final film thickness distribution should be 10% or less.
Was successful as a product. On the other hand, the web width direction before scraping
If the precoat coating thickness distribution exceeds 20%,
It is related to the type of precoat equipment and the type of scraping member.
And the final film thickness distribution exceeds 10%.
Was rejected. Also, what can be said from the examples and comparative examples.
Before scraping off the excess liquid with the scraping member
If the precoat coating thickness distribution in the web width direction is small,
In proportion to this, the final film thickness distribution is also reduced. this
The result is the coating thickness distribution in the web width direction before scraping.
Thickness in the web width direction of the final coating layer after scraping
It means to greatly affect the cloth. According to the coating method of the present invention, scraping off is performed.
Type application, ultrathin and uniform coating on flexible support
Not only can a fabric layer be obtained, but also the web width of the coating layer
The thickness distribution in the direction can also be significantly reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a coating apparatus to which a coating method of the present invention is applied.
Configuration diagram composed of an extrusion-type precoat device with backup, a doctor blade-type scraping member, and a slit-adjustable coating thickness distribution adjusting device. [Fig. 2] Cross-sectional view explaining a doctor blade [Fig. 3] Slit FIG. 4 is a perspective view in which a part of the adjustment-type coating thickness distribution adjusting device is cut away. FIG. 4 is a cross-sectional view of the slit-adjusting type coating thickness distribution adjusting device.
A support pressure extrusion type precoat device;
FIG. 6 is an explanatory diagram for explaining a support roller tilt type coating thickness distribution adjusting device. FIG. 7 is a diagram illustrating a support roller tilt type coating thickness distribution adjusting device. FIG. 8 is a side view of the doctor blade used in Test 1 of the embodiment. FIG. 9 is a side view of the doctor blade used in Test 2 of the embodiment. FIG. 10 is a side view of the doctor blade used in Test 3 of the example. FIG. 11 is a side view of the doctor blade used in Test 4 of the Example. Pre-coating device, 16 ... scraping member, 17 ... doctor blade,
18 ... support roller, 20 ... coating thickness distribution adjusting device,
22 ... coating head, 24 ... lip surface, 26 ... backup roller, 28 ... pocket part, 30 ... slit, 32 ...
Doctor blade tip surface, 34 ... yoke, 36 ... biasing screw, 38 ... fulcrum screw, 40 ... fixing screw, 42 ... tip, 44 ... action part, 46 ... biasing part, 48 ... fulcrum part, 50
... coating device, 52 ... coating head, 54 ... rod, 56 ...
Application thickness distribution adjusting device, 60 ... rotating shaft, 62 ... bearing, 6
4 ... Y-axis feed screw, 66 ... Universal joint, 6
8 ... moving body, 70 ... nut member, 72 ... motor, 74 ...
Hanging member, 76 ... rail, 80 ... X-axis feed screw

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Norio Shibata             1-2-1 Ogimachi, Odawara-shi, Kanagawa Pref.             Shishi Photo Film Co., Ltd. F-term (reference) 4D075 AC53 AC92 CA48 DA04 DB31                       DC27

Claims (1)

[Claims] [Claim 1] An application side surface of the support after applying a coating liquid more than a desired amount of coating liquid on the support by a pre-coating device while continuously running the belt-like support In the coating method in which the scraping member is relatively pressed to scrape off the excess of the excessively applied coating liquid with the scraping member, the scraping member before scraping off the excessive amount of the coating liquid A coating method, wherein the coating thickness distribution in the width direction of the support is 20% or less.