JP2001276706A - Coating apparatus and coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating apparatus having a coater die of an extrusion coating system and a backup roll for holding a support and capable of easily adjusting the uniformization of a film thickness in a coating width direction, and a coating method using the same. SOLUTION: In the coating apparatus for coating the strip-like object to be coated supported on the backup roll to continuous run by the extrusion coating system, distance adjusting members for adjusting the distance between the leading end part of the coater die and the surface of the strip-like object are arranged near the leading end of the coater die at an interval of 5-50 mm with respect to the width direction of the coater die.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extrusion coating apparatus which is used for producing photographic light-sensitive materials, magnetic recording media and the like, and which is used as an apparatus for applying various liquid coating compositions to a continuously running belt-shaped object to be coated. And a coating method using the coating device.

[0002]

2. Description of the Related Art Conventionally, as a method used in a coating apparatus which can be used for both a photographic photosensitive material and a magnetic recording medium, an extrusion coating method has a small fluctuation due to evaporation of a coating liquid at the time of coating and a mechanical precision. Is required, but the film thickness distribution,
It is used because of its excellent coating stability. In general, a coating apparatus is composed of a so-called coater die for supplying a coating liquid and a backup roll for uniformly holding the surface of a continuously running support in order to uniformly apply the coating to a body to be coated (hereinafter also referred to as a support). ing. The extrusion coating method is a method in which a coating liquid is extruded from the tip of a slit of a coater die and a coating liquid is extruded to form a bead on a continuously running support, and the coating method of the extrusion method is a combination of two or more bars. A supply port for supplying the coating liquid, a portion called a coater chamber for supplying the supplied coating liquid uniformly in the width direction of the coater die, and a slit for discharging the coating liquid from the coater chamber. This is a coating method in which a single-layer to multi-layer coating can be performed depending on the combination number of the bars.

In the production of photographic light-sensitive materials, when coating onto a support using an extruder coater die, gelatin is generally used as a binder in the photographic light-sensitive material. Hot water is circulated inside the die, and is usually kept at about 25 to 50 ° C. It is usually 1-2 on the width of each coater die for heat retention
(Or more) The coater dice is kept warm by flowing warm water with this flow path. The supplied coating liquid is also kept at a temperature of about 25 to 50 ° C. and supplied to the coater chamber of the coater die.

[0004] In the production of magnetic recording media, when applied to a support using an extruder coater die, the magnetic recording medium generally uses a resin such as polyurethane or polyester as a binder and a magnetic powder containing an organic solvent. Is usually kept at about 20 to 40 ° C. in order to prevent the solvent from evaporating and maintain the dispersibility, and the solution is supplied to a coater die through a filter to perform coating.

[0005] As the material of the coater die, precipitation hardening steel, austenitic steel, martensitic stainless steel and heat-resistant alloy, super steel, titanium alloy, ceramic, and other industrial steel materials can be used.

In an extrusion coating method in which a support is held on a backup roll, the main purpose of a coater die is to obtain a uniform coating distribution, but the coating distribution (film thickness) in the running direction of the support is basically The coating (thickness) distribution in the coating width direction can be controlled by the coating speed and the supply speed of the coating liquid. It is known that it is determined by the distance accuracy between the roll surface and the tip of the coater die.

For this reason, care must be taken when applying
The coating is performed after adjusting the slit gap of the coater die, the straightness of the tip of the coater die, and the straightness of the backup roll by mechanical processing, but when the coater die width becomes 1-2 m, the straightness is reduced. It takes a very long time and cost to carry out the processing work, but the mechanical processing accuracy is naturally limited. In addition, since errors due to the expansion of the coater die and the backup roll due to the temperature of the coating liquid appear, during actual coating, the film thickness in the coating width direction is adjusted by adjusting the temperature of the coating liquid, the temperature of the coater die, etc. by trial and error. It is the present condition that the co-coating is performed.

Furthermore, in recent years, it has become necessary to increase the viscosity of the coating solution because the coating speed has to be increased in order to increase the production amount, and the coating width is also increasing, and the production of a longer coated product has been required. Is needed. In addition, the coater dice tends to be thinner from the viewpoint of quality improvement or easiness of coating operation. Needless to say, further improvement is required for making the flow rate distribution of the coating liquid wider and uniform, and the following techniques are known as means for making the coating film thickness distribution in the coating width direction uniform. For example, JP-A-62-291117, JP-A-61-261022, and JP-A-1-2030074 disclose an extrusion-type coating apparatus provided with a means for setting a slit gap at a slit portion. . However, the simultaneous multi-layer coating of two or three or more layers is difficult in terms of installation, and even if it can be installed, it becomes complicated. JP-A-4-406
No. 8 discloses a method of continuously measuring a coating amount in a coating width direction and automatically controlling a slit gap. However, the apparatus is complicated, and in particular, a method in which the thickness direction of a coater die becomes thinner. It is difficult to implement, and it is difficult to adjust the slit gap to several microns or less. JP-A-5-4066 discloses that
Although a method of covering the coating device with a heat insulating material to prevent material deformation due to the temperature distribution of the coating device has been disclosed, a sufficient effect cannot be obtained when the slit gap physically changes. In particular, recent coater dies are required to be thinner, and even if the processing accuracy of the coater dies is made sufficient, the internal pressure due to the liquid pressure cannot be ignored, and the width distribution is affected by the change in the slit gap due to the internal pressure. Receive. Further, in a usual coating apparatus, it is necessary to flow various coating liquids, and the flow rate distribution is affected by the liquid conditions (viscosity, liquid temperature, flow rate). Japanese Patent Application Laid-Open No. 9-85149 discloses a coating apparatus having a mechanism in which at least one of a coater slit portion in an extrusion coating apparatus is movable to adjust a slit gap as a whole. It is said that even when the viscosity changes, the slit gap can be adjusted and the production efficiency is improved. However, in the disclosed technique only, since only the slit gap is adjusted, for example, the tip of the coater dice with respect to the backup roll surface holding the support,
In the case of a curved shape, it is difficult to obtain a good film thickness distribution. Japanese Patent Application Laid-Open No. H10-15461 discloses a coating device that adjusts the position of the slit portion by using a physical force near one end of the slit as a mechanism for adjusting the slit gap. . However, this disclosed technique is also an invention of an adjustment mechanism for only the slit gap of the coater, and is not an effective means for the film thickness distribution deterioration due to the uneven distance between the backup roll surface and the coater die tip.
As described above, in the extrusion coating apparatus, the development of a coating apparatus capable of easily adjusting the thickness uniformity in the coating width direction is desired.

[0009]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to make it possible to easily adjust the thickness uniformity in the coating width direction in a coating apparatus having a coater die of an extrusion coating type and a backup roll holding a support. An object of the present invention is to provide a coating device and a coating method using the coating device.

[0010]

Means for achieving the present invention will be described below.

1) In a coating apparatus for applying a continuous coating on a belt-shaped coated object supported by a backup roll by an extrusion coating method, a distance adjusting member between a tip end of a coater die and a surface of the strip-shaped coated object on the backup roll is coated with a coater. 5 in the width direction of the coater die near the die tip
A coating device, wherein the coating device is arranged at an interval of up to 50 mm.

2) The coating apparatus according to 1), wherein the distance adjusting member is a heating member. 3) The coating device according to 1), wherein the distance adjusting member is a piezo element.

[0014] 4) A coating method characterized in that the coating is performed using the coating apparatus according to any one of 1) to 3).

[0014]

Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited thereto.

FIG. 1 is a schematic view of an extrusion coating apparatus.
In the figure, 1 indicates the entire coating apparatus, 2 indicates a coater die, 3 indicates a backup roll, and the coating apparatus of the present invention indicates an apparatus including a coater die 2 and a backup roll 3. The coater dice 2 is a coater dice composed of a center bar 4, a front bar 5, and a back bar 6 and capable of simultaneously coating two layers. Although not shown in the figure, heating members are arranged at regular intervals near the bar tip. In the present invention, the vicinity of the bar tip means a range of 3 to 5 mm inward from the tip of each bar.

This type of coater die 2 can design a coater die for simultaneous multi-layer coating as required by increasing the number of center bars 4 among the center bar 4, front bar 5 and back bar 6. It is possible. 7
a shows a slit formed by the gap between the back bar 6 and the center bar 4, and 7b shows a slit formed by the gap between the back bar 6 and the front bar 5. In the present invention, the slit gap indicates the width of the slit 7a and the slit 7b,
The coating film thickness (amount) in the coating direction is determined by the width of the slit gap and the flow rate. Reference numerals 8a and 8b denote coater chambers, and the coating solution sent to the coater die 2 makes the pressure uniform in the width direction of the coater die 2 and the slits 7a and 8b.
It has a function for discharging a uniform amount from a and 7b. 9 is each bar 4, which constitutes the coater die 2,
5 and 6 show tip portions. In addition, the tip part is generally referred to as a coater die tip part. Reference numeral 10 denotes a support having a thickness of 10 to 200 μm. W indicates the distance between the coater die 2 and the surface of the support 10. 11
Denotes a coating solution applied to the support 10.

The viscosity of the coating liquid used in the coating apparatus of the present invention at a shear rate of 100 sec ^-1 is 1.0 × 10 5
The range is preferably from ^{−3 to} 5.0 × 10 ³ Pa · s, and more preferably from 1.0 × 10 ^{−2 to} 1.0 × 10 ³ Pa · s. If the viscosity is less than 1.0 × 10 ⁻³ Pa · s, the influence of the surface tension increases, and the applicability deteriorates.
When the viscosity exceeds 0 × 10 ³ Pa · s, the viscosity is too high, and the coating property is deteriorated.

The shear rate means the shear rate applied to the coating solution, and the viscosity of the coating solution at a shear rate of 100 sec ^-1 is determined by the paint flow and pigment.
Dispersion Second Edition
n Temple C.I. Patton 1979Joh
n Wiley & Sons, Inc. The values obtained by measuring the viscosity of the coating solution using a cone-type or double-cylinder type viscometer described in the above section are shown below.

As shown in FIG. 1, the uniformity of the coating film thickness in the coating width direction is affected by the slit gap of the coater die 2 and the distance W between the coater die 2 and the surface of the backup roll 3. Is an essential condition.

FIG. 2 is an exploded schematic perspective view of the coater die 2 of the present invention. Reference numerals 12a, 12b, and 12c denote positions at which the distance adjusting members provided near the tips of the bars are provided. The position of the distance adjusting member is 3 to 5 m from the tip 9 of each bar.
m, and the distance between the distance adjusting members is 5 to 50.
mm, more preferably 10 to 30 mm. If it is less than 5 mm, it is not preferable because it cannot be mounted, and if it exceeds 50 mm, it is not preferable because the intended effect cannot be obtained. As the distance adjusting member to be used, a heating member and a piezo element are shown. 13 is a coater die 2
14 shows bolts for fixing each bar when assembling
Reference numerals a, 14b, and 14c denote holes for passing bolts formed in the bars, and are arranged in the width direction. Reference numerals 15a and 15b denote supply ports for supplying the coating liquid to the respective coater chambers 8a and 8b.

FIG. 3 is a schematic view of a cross section of the back bar 6 taken along line AA 'in FIG. (A) shows a case where a heater is used as a distance adjusting member, and (b) shows a case where a piezo element is used as a distance adjusting member. In the drawing, reference numeral 16a denotes a hole for inserting a spirally wound linear heater as a heating member, and 16b denotes a hole for inserting a piezo element. The hole is provided through the tip of the back bar 6.
The center bar 4 and the front bar 5 are also provided with through-holes at the tips. Reference numeral 17 denotes a spirally wound linear heater. The surface of the spirally wound linear heater is covered with rubber to be insulated from the outside, is inserted into the hole 16a, and is fixed with epoxy resin. The center bar 4 and the front bar 5 can be arranged in the same manner. Reference numeral 18a denotes a heating temperature adjusting means. Reference numeral 19 denotes a piezo element. After the molded piezo element is put in the hole 16b, it is fixed with epoxy resin. The center bar 4 and the front bar 5 can be arranged in the same manner. Reference numeral 20a denotes a movement adjusting means of the piezo element.
The center bar 4 and the front bar 5 can be arranged in the same manner.

FIG. 4 is a schematic view showing an example of coating using a distance adjusting means using a helically wound linear heater among distance adjusting means arranged near the tip of the coater die in the present invention. . 21a, 21b, and 21c are disposed positions 12a, 12b of the distance adjusting member near the tip of each bar;
Reference numeral 12c denotes a heating means of a spirally wound linear heater provided in 12c, and reference numerals 18a, 18b, and 18c denote heating temperature adjusting means of the heating means 21a, 21b, and 21c provided in each bar. A plurality of the heating means 21a, 21b, 21c and the heating temperature adjusting means 18a, 18b, 18c are provided in accordance with the number of the helically wound linear heaters 17, and the helically wound linear heaters 17 are independently provided. The heating temperature can be adjusted. Reference numerals 22a and 22b indicate coating liquid tanks, reference numerals 23a and 23b indicate liquid feed pumps for feeding the coating liquid to the coater die, and reference numerals 24a and 24b indicate filters. Other symbols are the same as those in FIGS.

FIG. 5 is a schematic view showing an example of the application using the distance adjusting means by the piezo element among the distance adjusting means arranged near the tip of the coater die in the present invention. Reference numerals 25a, 25b, and 25c denote piezo element moving means disposed at the disposition positions 12a, 12b, and 12c of the distance adjustment member near the tip of each bar.
Reference numeral 0c denotes a movement adjusting means of the moving means provided on each bar. There are a plurality of the moving means 25a, 25b, 25c and the movement adjusting means 20a, 20b, 20c in accordance with the number of the piezo elements 19, so that the movement of the piezo elements 19 can be adjusted independently. Other symbols are the same as those in FIGS.

[0024]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto.

The formulation of the coating solution used for the photothermographic material is shown below. Heat-developable photosensitive layer coating solution (Preparation of photosensitive silver halide emulsion A) 7.5 g of ossein gelatin having an average molecular weight of 100,000 and 10 mg of potassium bromide were dissolved in 900 ml of water, and the temperature was adjusted to 35 ° C. and the pH was adjusted to 3.0.
Then, 370 ml of an aqueous solution containing 74 g of silver nitrate and 370 ml of an aqueous solution containing 1 × 10 ⁻⁴ mol per mol of silver of potassium bromide, potassium iodide and iridium chloride in a molar ratio of (98/2) were added to pAg7. 7, and added over 10 minutes by the controlled double jet method. Thereafter, 4-hydroxy-6-methyl-1,3,3
a, Add 0.3 g of 7-tetrazaindene, adjust the pH to 5.0 with NaOH, and adjust the average particle size to 0.06 μm;
Coefficient of variation of particle size 12%, [100] face ratio 87%
Of cubic silver iodobromide grains were obtained. This emulsion was subjected to coagulation sedimentation using a gelatin coagulant, and after desalting treatment, 0.1 g of phenoxyethanol was added to adjust the pH to 5.9 and the pAg to 7.5 to obtain a photosensitive silver halide emulsion A.

(Preparation of Powdered Organic Silver Salt A) 111.4 g of behenic acid and 83.8 of arachidic acid were added to 4720 ml of pure water.
g and 54.9 g of stearic acid were dissolved at 80 ° C. Next, while stirring at a high speed to adjust the pAg to 7, 540.2 ml of a 1.5 M aqueous sodium hydroxide solution was added, and the mixture was sufficiently stirred. Next, 6.9 ml of concentrated nitric acid was added, and the mixture was cooled to 55 ° C. to obtain a sodium organic acid solution. While the temperature of the organic acid sodium solution was kept at 55 ° C., the above-mentioned variously sensitized silver halide emulsions and comparative emulsions (each having a silver content of 0.1%) were prepared.
038 mol) and 450 ml of pure water were added and stirred for 5 minutes. Next, 760.6 ml of a 1 M silver nitrate solution was added over 2 minutes, and the mixture was further stirred for 20 minutes, and water-soluble salts were removed by filtration. Thereafter, the conductivity of the filtrate is 2 μS / c.
m, washing with deionized water and filtration repeatedly,
After performing centrifugal dehydration, hot air drying was performed at 37 ° C. until there was no loss in mass, to obtain a powdered organic silver salt A.

(Preparation of photosensitive emulsion dispersion) Polyvinyl butyral powder (Butvar B manufactured by Monsanto)
-79) 14.57 g of methyl ethyl ketone (MEK)
1457 g, and the powdered organic silver salt A obtained under the above drying conditions while stirring with a dissolver type homogenizer.
500 g was slowly added and mixed well. Then 1m
Dispersion was performed at a peripheral speed of 13 m and a residence time of 3 minutes in a mill with a media type dispersing machine (manufactured by gettzmann) filled with 80% of mZr beads (manufactured by Toray) to prepare a photosensitive emulsion dispersion.

500 g of the above photosensitive emulsion dispersion and MEK
100 g was kept at 21 ° C. while stirring. Pyridinium hydrobromide perbromide (PHP 0.45 g) was added and stirred for 1 hour. Further, calcium bromide (3.25 ml of a 10% methanol solution) was added, followed by stirring for 30 minutes.

(Preparation of Coating Solution for Photosensitive Layer) Next, a mixed solution of sensitizing dye 1, 4-chloro-2-benzoylbenzoic acid and a supersensitizer (5-methyl-2-mercaptobenzimidazole) ( A mixing ratio of 1: 250: 20, a 0.1% methanol solution of sensitizing dye (7 ml) was added, and the mixture was stirred for 1 hour, and then cooled to 13 ° C., and further stirred for 30 minutes. While keeping the temperature at 13 ° C, polyvinyl butyral 48
g was added and dissolved sufficiently, and then the following additives were added to prepare a photosensitive layer coating solution.

Developer (1,1-bis (2-hydroxy-3,5-dimethylphenyl) -2-methylpropane) 15 g Desmodu N3300 (Mobay's aliphatic isocyanate) 1.10 g Phthalazine 1.5 g Tetrachlorophthalic acid 0.5 g 4-methylphthalic acid 0.5 g

[0031]

Embedded image

(Preparation of Coating Solution for Back Coat Layer) While stirring with 830 g of methyl ethyl ketone, 84.2 g of cellulose acetate butyrate (CAB 381-20, Eastman Chemical) and 4.5% of polyester resin (Vitel PE2200B, Bostic).
g was added. 0.30 g of infrared dye 1 was added to the dissolved solution.
Then, 4.5 g of an F-based activator (Asahi Glass Co., Ltd. Surflon KH40) dissolved in 43.2 g of methanol and 2.3 g of another fluorine-based surfactant (Dai Nippon Ink Co., Ltd. MegaFag F120K) were added. The mixture was sufficiently stirred until dissolved. Finally, silica dispersed in methyl ethyl ketone at a concentration of 1% by mass with a dissolver-type homogenizer (Syloid 64X600 manufactured by WR Grace)
0) was added and stirred to prepare a coating solution for the back coat layer.

[0033]

Embedded image

(Surface Layer Coating Solution) First, a calcium carbonate dispersion was prepared by the following method. Cellulose acetate butyrate (CAB17 from Eastman Chemical Company)
1-15) 7.5 g of MEK was dissolved in 42.5 g of MEK, and calcium carbonate (SpecialtyMine) was added thereto.
rals Super-Pflex200) (5 g) was added, and a dissolver-type homogenizer was used at 8000 rpm.
m for 30 minutes.

Then, while stirring with 865 g of methyl ethyl ketone, cellulose acetate butyrate (Eas
tman Chemical Company CAB171-15)
96 g, polymethylmethacrylic acid (Rohm & Haas Company)
4.5 g of Paraloid A-21) was added and dissolved. 1.5 g of vinyl sulfone compound HD-1, 1.0 g of benztriazole, and 1.0 g of F-based surfactant (Surflon KH40, Asahi Glass Co., Ltd.) were added to this liquid and dissolved. Finally, 30 g of the above calcium carbonate dispersion was added and stirred to prepare a coating solution for the surface protective layer.

HD-1: CH ₂ ＣＨCHSO ₂ CH ₂ CH
(OH) CH ₂ SO ₂ CH = CH _{2 In the} following Examples and Comparative Examples, the support was a commercially available biaxially stretched and heat-fixed PET film having a thickness of 175 μm and a width of 2 m, and a line speed of 100 m / min. Was applied and dried. At this time, the surface protective layer and the photosensitive layer were coated using the coating apparatus of the present invention so that the dry thickness of the surface protective layer was 2.5 μm and the silver amount of the photosensitive layer was 2.4 / m ² . Each layer was coated and dried. The back coat layer was applied so that the dry film thickness was 3.5 μm.

Example 1 At the time of the above coating, the local temperature at the tip of the coater die was measured by a heating method as shown in Table 1 while measuring the thickness variation in the coating width direction with a transmittance measuring type in-line densitometer. Was changed in the width direction, and the heating member corresponding to the portion where the film thickness variation was large was heated to adjust the distance between the coater head and the surface of the support on the backup roll to perform coating. The heating member used was a linear heater of 10 W · h spirally wound as shown in FIG.

[0038]

[Table 1]

In the above table, the coating conditions No. In the case of 1-1, since the arrangement intervals of the heating members were narrow, the arrangement processing could not be performed, and thus no coating was performed.

(Comparison of Film Thickness Concentration Distribution) The photothermographic material prepared above was exposed with a laser sensitometer having a semiconductor laser of 810 nm. Thereafter, using an automatic developing machine having a heat drum, a heat development treatment was performed at 110 ° C. for 15 seconds to obtain a coating film thickness measurement sample. At that time, exposure and development were performed in a room conditioned at 23 ° C. and 50% RH.

(Measurement of Optical Transmission Density at 400 nm) Using a spectrophotometer UV-1200 manufactured by Shimadzu Corporation, the transmission density at 400 nm of the unexposed portion of the sample after development was measured in a lateral direction at a total of 200 points. The results are shown in Table 2 as the standard deviation (%) of the concentration distribution. The standard deviation of the concentration distribution (%) is a value calculated from the following equation.

Density distribution standard deviation (%) = standard deviation of 200 points / average density of 200 points × 100

[0043]

[Table 2]

As shown in the above table, the effectiveness of the spacing of the heating members of the coater die tip heating system of the present invention was confirmed.

Example 2 At the time of performing the above coating, the arrangement intervals of the piezo elements were changed in the width direction as shown in Table 3 in each part of the center bar, the front bar and the back bar constituting the coater die head. Using a coater dice, measure the thickness variation in the coating width direction with a transmittance measurement type inline densitometer, adjust the piezo element corresponding to the place where the thickness variation is large, and support the coater head and the backup roll on the backup roll The coating was performed by adjusting the distance between the surfaces.

[0046]

[Table 3]

In the above table, the coating conditions No. In the case of No. 2-1, since the arrangement interval of the piezo elements was narrow and the arrangement processing could not be performed, no application was performed.

With respect to the sample coated under the above conditions, exposure and heat development were performed in the same manner as in Example 1, and the film thickness concentration distribution of the sample was measured in the same manner as in Example 1. The results are shown in Table 4.
Shown in

[0049]

[Table 4]

As shown in the above table, the effectiveness of the arrangement intervals of the piezo elements of the present invention was confirmed. Example 3 At the time of performing the above coating, the arrangement interval of the piezo element was changed in the width direction as shown in Table 5 in each part of the center bar, the front bar, and the back bar constituting the coater die head. Using a coater die (straightness: 50 μm / m) where the straightness of the part is not obtained, while measuring the thickness variation in the coating width direction with a transmittance measurement type in-line densitometer, it corresponds to the location where the thickness variation is large. The coating was performed by adjusting the distance between the coater head and the surface of the support on the backup roll. In the table, the coating conditions No. 3-1 shows a comparison performed without using a piezo element.

The straightness was measured by placing a coater die on a stone surface plate, scanning in the width direction using a laser displacement meter, measuring the position of the tip, and determining the difference between the maximum value and the minimum value. Asked from.

[0052]

[Table 5]

With respect to the sample coated under the above conditions, exposure and heat development were performed in the same manner as in Example 1, and the film thickness concentration distribution of the sample was measured in the same manner as in Example 1. The results are shown in Table 6.
Shown in

[0054]

[Table 6]

As shown in the above table, it was confirmed that the effect of the present invention can be obtained even when a coater die having a bad straightness at the tip of the coater die is used.

The straightness of the backup roll is 30 μm.
The same effect was obtained as a result of the same test as described above using the m-type material, and it was confirmed that the present invention could obtain the effect even when the straightness of the backup roll was not obtained.

Example 4 When performing the above coating, a coating solution was used in which the viscosity of the coating solution was changed as shown in Table 7 using a thickener. The viscosity measurement is a value measured according to the above method.

[0058]

[Table 7]

A piezo element is used as a means for adjusting the position of the tip of the coater die. The piezoelectric element is disposed at intervals of 15 mm at the ends of the center bar, front bar and back bar in the width direction of the coater die, and the film thickness variation in the coating width direction is transmitted. While measuring with a rate measuring type in-line densitometer, the piezo element corresponding to a portion where the film thickness variation was large was adjusted, and the distance between the surface of the support on the backup roll at the tip of the coater die was adjusted to perform coating.

With respect to the sample coated under the above conditions, exposure and heat development were performed in the same manner as in Example 1, and the film thickness concentration distribution of the sample obtained was measured in the same manner as in Example 1. The results are shown in Table 8.
Shown in

[0061]

[Table 8]

As shown in the above table, the effectiveness of the viscosity of the coating liquid when using the coating apparatus of the present invention was confirmed.

[0063]

According to the present invention, it is possible to easily adjust the distance between the coater die and the support surface on the backup roll for a wide coater die, a low straightness coater die, and a backup roll. ,
In addition to making it very easy to handle a wide range of coating liquids with different viscosities, coating with a uniform film thickness distribution of the coating width becomes possible.
The quality of coated products can be greatly improved.

[Brief description of the drawings]

FIG. 1 shows a schematic view of an extrusion coating apparatus.

FIG. 2 is an exploded schematic perspective view of a coater die.

FIG. 3 shows a schematic view of a cross section of a back bar.

FIG. 4 is a schematic view showing an example of application using a distance adjusting means by a helically wound linear heater.

FIG. 5 is a schematic view showing an example of application using a distance adjusting unit using a piezo element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Whole coating device 2 Coater dice 3 Backup roll 4 Center bar 5 Front bar 6 Back bar 7a, 7b Slit 8a, 8b Coater chamber 9 Tip part of each bar 10 Supporters 12a, 12b, 12c Arrangement position of distance adjusting member 16a , 16b Hole 17 Spirally wound linear heater 18a, 18b, 18c Heating temperature adjusting means 19 Piezo element 20a, 20b, 20c Moving adjusting means 21a, 21b, 21c Heating means 25a, 25b, 25c Piezo element moving means W Distance between coater die and surface of support

Claims (4)

[Claims] 1. A coating apparatus for applying a coating material by extrusion coating onto a continuously running belt-shaped object supported by a backup roll, wherein a distance adjusting member between a tip end of a coater die and the surface of the belt-shaped object on the backup roll is coated. 5 to the width direction of the coater die near the die tip
A coating apparatus, wherein the coating apparatuses are arranged at intervals of 50 mm. 2. The coating apparatus according to claim 1, wherein the distance adjusting member is a heating member. 3. The coating apparatus according to claim 1, wherein the distance adjusting member is a piezo element. 4. A coating method using the coating apparatus according to claim 1.