WO1991016998A1

WO1991016998A1 - Method and device for applying liquid

Info

Publication number: WO1991016998A1
Application number: PCT/JP1991/000571
Authority: WO
Inventors: Atsuhiko Suda; Yoshikazu Kai; Naoki Kawasaki
Original assignee: Hitachi Maxell, Ltd.
Priority date: 1990-04-27
Filing date: 1991-04-26
Publication date: 1991-11-14
Also published as: EP0481088A1; EP0481088A4

Abstract

A method and device for applying liquid, in which, for applying liquid onto the base film by the use of an extrusion type applying head, a flexible body is outwardly extended from the slit opening on the downstream side of the liquid flowing slit of the extrusion type applying head so as to be in contact with the surface of a base film moving continuously, whereby liquid emitted from the liquid flowing-out slit and to be applied onto the base film is evenly applied while being smoothed by the flexible body without causing uneven thickness or streaks of liquid even over a wide range of application conditions.

Description

明

Coating method and coating equipment S

[Technical field]

The present invention relates to a method and an apparatus for applying a coating solution using an extrusion type coating head, and more particularly, to a coating method using an extrusion type coating head and applying the coating solution in a wide IS area. The present invention relates to a method and an apparatus for uniformly applying a coating without causing unevenness in thickness.

[Background technology]

Generally, a gravure method is used to apply a variety of aqueous solutions and fats, or various dispersions obtained by mixing and dispersing various powders in a dispersion medium such as water or an organic solvent, onto a continuously moving base film. Indirect coating methods, such as a nick, a re-roll roll method, and a kiss coat method, have been widely put into practical use.

However, in these indirect coating methods, the coating liquid is in the air. Because of exposure, there is a difficulty in applying a coating solution that tends to change its properties. Particularly, in the case of a magnetic coating solution made of SS by mixing and dispersing magnetic powder with an antagonist resin, etc., this inconvenience occurs. Remarkably, property changes occur due to exposure in the air, and coating quality tends to deteriorate. Therefore, in recent years, direct coating methods such as an extrusion method have been used instead of these indirect coating methods. (JP-A-57-84771, JP-A-58-106466, JP-A-60-238179)

However, the extrusion method, which is a direct application method, is completely sealed until the application liquid is applied onto the base film, so that a change in the properties of the application liquid can be suppressed as much as possible. Although it is easy to respond to the speeding up of the coating process, the range of the amount of coating that can be applied and the range of the viscosity of the coating solution that can be handled are narrow. In addition, since the coating liquid outflow slittro of the coating head is pressed against the base film, the coating is performed downstream of the coating head. The side slitro becomes the doctor edge, and if it is used repeatedly, the downstream's slittro wears and changes its shape, causing the coating thickness to change and the coating film to change.

The quality will be reduced. In particular, coatings containing abrasive particles such as magnetic coating solutions

When using a cloth liquid, the downstream slittro is significantly worn,

It is difficult to maintain quality.

[Disclosure of the Invention]

The present invention has been made as a result of various studies in view of the present situation.

Therefore, when applying the coating solution onto the base film using the extrusion type coating head, the application of the extrusion type coating head

可撓 A flexible body extends outward from the outflow slit downstream slittro, and

By contacting the surface of the base film that moves in a gun,

Discharged from the coating solution outflow slit and applied on the base film

Apply the coating solution while smoothing it with a flexible body.

Uniform coating without uneven thickness and coating streaks

That's what I did. — —

[Brief description of drawings]

FIG. 1 is a schematic view of the tip of an extrusion type coating head showing an example of the coating apparatus S of the present invention,

FIG. 2 is a schematic explanatory view showing a coating step of the coating to the coating.

[Example]

Hereinafter, a description will be given, with reference to the drawings, of a coating solution coating device used in the present invention.

Fig. 1 shows the tip of the extrusion type coating head used in the present invention. A coating liquid outflow slit 4 is provided between the coating liquid upstream end 3 and the flexible body 5 in the coating liquid outflow slit 4 on the coating head downstream end 2 side. It extends outwardly from a downstream slittro 41 of the coating solution outflow slit 4.

Fig. 2 shows the application of the coating liquid onto the base film by discharging the coating liquid from slit 4 of this extrusion-type coating head. The extension 茚 51 of the flexible body 5 installed outside from the slit □ 41 on the downstream side of the coating solution outflow slit 4 is attached to the downstream end 2 of the coating head. The coating wave 7 discharged from the coating liquid outflow slit 4 is bent by the side of the flexible film 5 so as to be in contact with the continuously running base film 6. It is applied while being smoothed.

Thus, the coating liquid 7 is discharged from the coating liquid outflow slit 4 and, at the same time, is smoothed by the extending portion 51 of the flexible body 5, so that the coating liquid 7 is uniformly formed without uneven thickness and coating stripes. Even if the application conditions such as the viscosity, application speed, and application amount of the application liquid 7 are changed, the smoothing process is performed by the extended portion 51 of the flexible body 5, so that it is excellent in a wide range of application conditions Application is performed. In addition, since the downstream slittro 41 of the coating liquid outflow slit 4 does not become a doctor's edge, the downstream slitro 41 may wear and change its shape even when used repeatedly. In addition, even a coating solution 7 containing abrasive particles such as a magnetic coating solution can be repeatedly applied under the same conditions, and the quality of the coating film does not deteriorate. In this manner, the flexible body 5 extending outward from the downstream slit port 41 of the coating liquid outflow slit 4 has a bending rigidity E · I (E is a longitudinal elastic modulus, I is the section modulus) is lower than 0.0 1 kg'nn ^2, easily enters wrinkled flexure 5 itself during application, for leading to uneven thickness of the long period of coating width, is 0.0 l kg'nm ² or more Is preferred. However, if it is higher than 15 kgini ² , the coating liquid 7 cannot be smoothed well, the doctor effect more than necessary is exerted, the coating liquid is scraped off, and the bending rigidity of the flexible body 5 is further reduced. Because of the high height, it is necessary to increase the pressing force of the application head 1 against the base film 6, so that when the thin base film 6 is applied, the surface of the base film 6 may be damaged. Therefore, it is preferred that the flexural rigidity E · I in width 5 0 0 marrow in the range of ^{0.0 1 kg 's ~ 1 5kgi} 2, 0.1 kg'mn! 2 ~ 1 0 kg'nnn * in the range of More preferably, there is. In addition, if the length of the extending portion 51 extending outward from the downstream slittro 41 of the flexible body 5 is shorter than 3 mm, the intended effect cannot be obtained, and If the length is long, the coating surface of the coating liquid 7 will be rough, so the coating of the coating head 1: the downstream slit 4 of the cloth outflow slit 4 should be 3 to 30 mm long from 1. I like it.

As such a flexible member 5, a film-like member is preferably used. For example, polyester films such as polyethylene terephthalate, polyethylene-2,6-naphthalate, polyethylene, and polyolefin Poriorefui down film, cellulose绣導of equal, polyethylene Kabone DOO, polyimide, polyamide Doimi and Burasuchi' Kufi Lum such de, _c etc. Furthermore foil such as aluminum or other alloys are used ^ are as preferred

When such a flexible member 5 is attached to the downstream end 2 of the coating head and extends outward from the downstream slit 41 of the coating liquid outflow slit 4, the liquid of the coating wave 7 is formed. The balance between the pressure, the bending rigidity of the flexible body 5 and the pressing amount of the coating head 1 and the rigidity and the tension of the running base film 6 is HI-knotted, and the coating liquid 7 is smoothly smoothed. And 15 wide coating ^ Under the conditions, without uneven thickness and coating streaks, uniform: coating is performed,

Next, embodiments of the present invention will be described.

Example 1

Co-coated 7-FeiOs (major axis 500 parts by weight, diameter 0.4 / m, minor axis diameter 0, 0,5 m,

Coercive force 600 eelsted)

Nitrocellulose 5 0 ペン Pendex T-1 5 2 5 0 3 0

Nippon Inki Chemical Industry Co., Ltd.

Polyurethane resin)

C σ nate L (Nippon Polyurethane 2 0

Trifunctional low molecular

Amount of isocyanate compound)

Mogar L (Cabot, 10 Carbon black)

Myristic acid 3

Butyl stearate 2

Methyl isobutyl ketone 7 2 0

Truen 72 0

This composition was mixed and dispersed in a ball mill for 72 hours to prepare a magnetic coating material having a viscosity of 0.118 p at a temperature of 25 ° C and a shear rate of 10 ^ S- ¹ . As shown in the figure, polyethylene terephthalate with a thickness of 36 / zm, a width of 500 mm, a length of extension of ²⁰ mm, and a bending stiffness of 1.2 kg'mi ² when the width is 500 dragon The flexible body 5 made of SUS304 was supplied to an application type coating head 1 made of SUS304 mounted in the coating liquid outflow slit 4 on the downstream side 2 of the coating head.

Next, it is applied on a running polyester film 6 having a thickness of 1 and a width of 508 at an application speed of 15 Om / min and an application width of 48 Omm, and is dried. Magnetic layer with a thickness of 4.0 m after drying Was shaped.

Example 2

In the composition of the magnetic coating material in Example 1, the amount of methylisobutyl ketone was changed from 720 parts by weight to 600 parts by weight, and the amount of tolune was changed from 720 parts by weight to 650 parts by weight. Except that the viscosity was G at a temperature of 25 and a shear rate of i in the same manner as in Example 1 except that the viscosity was changed to G.

A magnetic coating of 3 Op was prepared, and a magnetic coating having an applied amount of 2 Scc / m * and a thickness after drying of 4.0 / ιη was formed.

Example 3

In the composition of the magnetic paint in Example 1, the amount of methylisobutyl ketone used was changed from 720 parts by weight to 580 parts by weight, and the amount of toluene used was changed from 720 parts by weight to 580 parts by weight. A magnetic coating with a viscosity of 0.64p at a shear rate of 1 (^ S- ¹ ) was prepared at a temperature of 25 and a coating amount of 2 Occ / m ² , a magnetic layer having a thickness of 4.0 πι after drying was formed. Jeongjeong 4

In Example 1, in place of the flexible body 5 used in Example 1, the thickness was 36 m, the width was 5200 mm, the length of the extension was 2 Omm, and the width was 500 mm. A flexible body 5 made of polyethylene terephthalate with a flexural rigidity of 3.3 kg'mm ² was used, and this flexible body 5 was mounted in the coating liquid outflow slit 4 on the downstream side 2 of the coating head. Was applied in the same manner as in Example 1 to form a magnetic coating having a coating amount of 28 cc / m ² and a thickness of 4.0 m after drying.

Example 5

In Example 2, instead of the flexible member 5 used in Example 2, the flexural rigidity when the thickness was 36 j ^ m, the width was 520, the extension was 2 Omm, and the width was 500 There using flexible body 5 made of polyethylene terephthalate rate of 3.3 kg'mm ^2, except that attached to the flexible member 5 and the coating head downstream end 2 side coating liquid outflow Sri Tsu DOO 4 is The magnetic paint was applied in the same manner as in Example 2, and the applied amount was 22 <: (! / ^, And the thickness after drying was 4.0. _c with a magnetic layer of m

Example 6

In Example 3, in place of the flexible member 5 used in Example 3, a thickness of 36 m, a width of 500 mm, an extension Φ of 20 mro and a width of 500 mm was used. A flexible body 5 made of polyethylene terephthalate with a bending stiffness of 3.3 kg'mni ² is used, and this flexible body 5 is applied to the coating: Attached in the coating liquid outflow slit 4 on the downstream end 2 side Other than the above, a magnetic paint was applied in the same manner as in Example 3 to form a magnetic layer having an applied amount of 2 Occ / and a thickness of 4.0 m after drying.

Comparative example 1

In Example 1, in place of the extrusion-type coating head used in Example 1, a flexible body was not attached, and the surface of the tip of the rod was finished to 1 s. A magnetic paint was applied in the same manner as in Example 1 except that an extrusion type coating head made of 4 was used, but the coating could not be applied. Ratio school ^ 2

In Example 2, instead of the extrusion-type coating head used in Example 2, a flexible body was not attached, and the surface of the tip of the coating head was finished to 1 s, and was made of SUS304. A magnetic paint was applied in the same manner as in Example 2 except that an extrusion-type coating head was used, and a magnetic material having a dry cloth thickness of 22 ccZm ² and a thickness of 4.0 m after drying was used. A layer was formed.

Ratio ^ Example 3

In Example 3, in place of the extrusion-type coating head used in Example 3, a flexible body was not attached, and the surface of the tip of the coating head was finished for 1 s. The application of the magnetic paint was performed in the same manner as in Example 3 except that an extrusion type coating head was used.

In each of the examples and comparative examples, the application surface properties of the magnetic debris obtained by applying the magnetic paint were visually observed. (〇), a case where coating streaks were slightly observed (△), and a case where coating streaks were large (X) were evaluated. In addition, the coating thickness unevenness in the coating width direction of the magnetic layer was examined using a fluorescent X-ray micro-thickness film thickness meter (manufactured by Seiko I-Electronic Industries; SFT-156, collimator spot diameter 0.5 nun), The deviation from the film thickness is shown as a percentage. Table 1 below shows the results _c Table 1

[The invention's effect]

As is clear from the above embodiments and comparative examples, the present invention -1 δ-makes it possible to apply even a coating solution having a viscosity that could not be applied with the coating head alone. Further, as is clear from Table 1, the coating apparatus and the coating method of the present invention can be applied. The magnetic layers (Examples 1 to 6) obtained in (1) and (2) had better coated surface properties and uneven coating thickness compared to the magnetic coating obtained by the conventional coating method (Comparative Examples 2 and 3). Therefore, according to the coating apparatus and the coating method of the present invention, even if the coating conditions are changed over a wide range using coating materials having different viscosities, the coating is performed without causing unevenness in coating thickness and coating streaks. It can be seen that high quality coatings can be obtained with good application I, which can greatly contribute to the improvement of productivity.

Claims

-16-Scope of request

1. When the coating liquid (7) is applied to the continuously moving base film (6) using the extrusion-type coating head (1), the above-mentioned extrusion-type coating head is used. A flexible body (5) is extended outwardly from a slittro (41) on the downstream side of the coating solution outflow slit (4) of (1), and the flexible body (5) is continuously moved. The coating liquid (7) discharged from the cloth liquid outflow slit (4) and applied onto the base film (6) is brought into contact with the surface of the base film (6), and is applied to the flexible body (5). ) Is a method for applying a coating solution, which is characterized in that the coating is performed while smoothing.

2. The flexible body (5) is coated east of the coating solution according to claim 1, wherein the flexible member having a flexural rigidity of 0 · 0 1 kg 'nun ² ^ 1 5 when the width 5 0 0 marrow Method.

3. The flexible body (5) is a flexible body extending outward from the slit downstream side slit port (41) of the coating head (1) by 3 to 30 reading. A method for applying the coating solution according to claim 1. -1 7-

4. In the coating apparatus for applying the coating liquid (7) onto the continuously moving base film (6) using the extrusion-type coating head (1), the above-mentioned extrusion-type coating head is used. The flexible body (5) is extended outward from the downstream slittro (41) of the coating liquid outflow slit (4) of (1), and this flexible body (5) is connected continuously. The coating liquid (7) discharged from the coating liquid outflow slit (4) and applied on the base film (6) is brought into contact with the surface of the base film (6) that moves in a moving manner. Applicator for coating liquid that is applied while being smoothed by flexible body (5).

5. The flexible body (5) is, 0. 0 1 kg 'fliin 2 ~ 1 5 kg' coating ¾ of claim 4 wherein the flexible member having a flexural rigidity of nm ^s when the width 5 0 0 Coating equipment.

6. The flexible body (5) is a flexible body that extends 3 to 30 outward from a slit downstream slit (41) of the coating head (1). Applicator for the coating liquid described in 4.