JP2008168268A - Bar coater and bar coating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bar coater capable of preventing the generation of a failure on a coating surface by suppressing vibrations of a coating bar, and a bar coating method using this bar coater. <P>SOLUTION: The bar coater for coating a travelling support body 12 with a coating liquid by a coating bar 14 includes a rotation driving source 26 for generating a rotation driving force, a bar driving shaft 30 for transmitting the rotation of the rotation driving source 26 to the coating bar 14, wherein the rotation driving force of the rotation driving source 26 is transmitted to the bar driving shaft 30 through a belt 28. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a bar coating method and apparatus, and in particular, an optical film such as an optical compensation film, a photographic photosensitive material, a magnetic recording medium and the like are manufactured by applying a coating solution to a flexible support (hereinafter referred to as “web”). The present invention relates to a bar coating method and apparatus suitable for the above.

  Examples of the coating apparatus that applies the coating liquid to the web surface include a bar coating apparatus (bar coater), a reverse roll coating apparatus, a gravure roll coating apparatus, and an extrusion coating apparatus. Among these, the bar coating apparatus is employed as a coating apparatus in the production of optical films and magnetic recording media because the equipment is simple and thin layer coating is possible.

  This bar coating apparatus is roughly classified into the following two types. The first type is an integrated application / metering type system in which a continuously running web is brought into contact with a rotating coating bar, and transfer coating of a coating liquid and measurement of a desired coating amount are simultaneously performed on the web. .

  The second type is a method of measuring a desired coating amount by applying an excessive coating solution to a web with a pre-coating apparatus, and contacting the rotating coating bar to scrape off the excess coating solution. This is a separate type system for coating and weighing.

  In any type of bar coating apparatus, conventionally, a coating bar such as a flat bar, a wire bar, and a grooved bar is supported on the support groove of the bar support base so as not to bend and the coating bar is used. Both sides of the motor were directly connected to the rotary shaft of the rotary drive device. Then, by rotating the coating bar with the rotation drive device, foreign matter is prevented from being trapped between the coating bar and the web, thereby preventing the occurrence of coating stripes due to the foreign matter.

  By the way, in recent years, there is a demand for a coating technique for precisely coating an ultra-thin layer having a layer thickness of 2 μm or less in an optical film or the like, and a coating bar having an outer diameter of 1 mm to 10 mm is used. It is becoming.

  When the diameter of the coating bar is large as in the past, even if there is a problem that the coating bar is not evenly supported in the support groove due to the misalignment between the coating bar and the rotation drive device, The coating bar did not bend enough to cause unevenness and vibration.

  However, if the coating bar becomes thin and the rigidity is reduced, a slight misalignment between the coating bar and the rotation drive device causes a problem that the coating bar is not evenly supported in the support groove, which causes the coating bar to be coated. There arises a problem that the working bar is bent.

  As a result, rotation unevenness and vibration occur in the coating bar, and application unevenness occurs in the coating layer applied to the web.

  On the other hand, in order to eliminate uneven rotation and vibration of the coating bar, the coating bar and the rotation drive device are aligned with high precision so that the entire length of the coating bar is relative to the support groove. Although it is necessary to adjust so that it may be supported evenly, it takes a long time for centering, which is problematic in terms of productivity.

  On the other hand, even if the coating bar has a small diameter in order to make the coating film extremely thin by the present applicant, there is no occurrence of uneven rotation due to rotation and vibration, and the coating bar. There has been proposed a bar coating device that does not require centering between the rotary drive device and the rotary drive device (Patent Document 1).

In this proposal, the rotational drive device and the coating bar are connected by a coupling member having a degree of freedom, and thereby, there is a slight misalignment between the rotational drive device and the coating bar. Even if it exists, it is related with the bar coating apparatus of the structure by which a coating bar is equally supported by a support groove | channel, and the predetermined effect is confirmed.
JP 2003-175358 A

  However, when the vibration during rotation of the coating bar increases, coating surface failure such as stepwise coating unevenness and bubble streaks (streaks caused by the generation of bubbles) may occur on the coating surface of the support. In particular, when the coating bar is rotated at a high speed, a coating surface failure tends to occur.

  In view of the above facts, an object of the present invention is to obtain a bar coating apparatus capable of preventing the occurrence of a coating surface failure by suppressing the vibration of the coating bar, and a bar coating method using the bar coating apparatus.

  In order to achieve the above-mentioned object, the invention according to claim 1 of the present invention is a bar coating apparatus for applying a coating solution by a coating bar on a traveling support, and a rotational driving source for generating rotational driving force, A bar coating apparatus having a bar drive shaft for transmitting rotation of a rotary drive source to the coating bar, wherein the rotational drive force of the rotary drive source is transmitted to the bar drive shaft via a belt. A bar coating apparatus is provided.

  According to the first aspect of the present invention, since the rotational driving force generated by the rotational driving source is transmitted to the bar driving shaft via the belt, the rotational unevenness generated when the rotational driving source generates the rotational driving force. And vibrations are not transmitted to the application bar via the bar drive shaft. For this reason, the coating bar does not sway during the bar coating, and coating unevenness does not occur in the coating film formed on the support.

  A second aspect of the present invention is characterized in that, in the first aspect, the whirling of the tip connected to the coating bar of the bar drive shaft is 100 μm or less.

  According to the second aspect of the present invention, since the whirling of the tip of the bar drive shaft at the time of bar coating is restricted, the coating bar is free from rotational unevenness and vibration and is formed on the support. Coating unevenness does not occur in the film.

  According to a third aspect of the present invention, in any one of the first or second aspect, the bar drive shaft is supported at two or more points.

  According to the third aspect of the present invention, since the bar drive shaft is securely supported at two or more points, when the rotational power is transmitted from the rotational drive source to the bar drive shaft, the bar drive shaft has Even when the external force is applied, rotation irregularities and vibrations do not occur on the rotating shaft of the bar drive shaft. For this reason, the coating bar does not sway during the bar coating, and coating unevenness does not occur in the coating film formed on the support.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the bar drive shaft is coupled to the application bar via a coupling.

  According to the fourth aspect of the present invention, even if there is a slight misalignment between the shaft center between the bar drive shaft and the application bar, vibration caused by the misalignment of the shaft core is less likely to be transmitted to the application bar. Coating unevenness does not occur in the coating film formed on the body.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, a static torsional spring constant of the coupling is 3400 N · m / rad or less.

  According to the fifth aspect of the present invention, the vibration due to the deviation between the axis of the rotational drive source and the axis of the coating bar is less likely to be transmitted to the coating bar, and the vibration of the coating bar is further suppressed. Coating unevenness does not occur in the coating film formed on the support.

  A sixth aspect of the invention according to any one of the first to fifth aspects is characterized in that the rotation axis of the bar drive shaft intersects with the rotation axis of the coating bar at an angle of 1 ° or less. .

  According to the sixth aspect of the present invention, the vibration due to the deviation between the rotation axis of the rotation drive source and the rotation axis of the application bar is not easily transmitted to the application bar, and the application bar does not swing and the bar is applied. In addition, coating unevenness does not occur in the coating film formed on the support.

  According to a seventh aspect of the present invention, in the bar coating method in which the coating liquid is transferred and applied to a belt-like support that travels through the coating bar while the coating bar is rotated by the rotational driving source, the rotation of the rotational driving source is changed to a belt. The bar coating method is characterized in that it is supplied to the coating bar via

  According to the seventh aspect of the present invention, since the rotation drive source and the bar drive shaft are coupled via the belt, the rotation unevenness and vibration generated when the rotation drive source generates the rotation drive force are It is not transmitted to the application bar via the drive shaft. For this reason, the coating bar does not sway during the bar coating, and coating unevenness does not occur in the coating film formed on the support.

  According to the present invention, it is possible to prevent the occurrence of a coating surface failure by suppressing the vibration of the coating bar.

  Hereinafter, a preferred embodiment of a bar coating apparatus according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram showing a first embodiment of a bar coating apparatus according to the present invention. FIG. 2 is an enlarged schematic configuration diagram in the vicinity of the coating bar of the bar coating device according to the present embodiment. FIG. 3 is an enlarged schematic configuration diagram in the vicinity of the bar drive shaft of the bar coating apparatus according to the present embodiment.

  As shown in FIGS. 1 and 2, the bar coating apparatus 10 according to the present embodiment has a coating bar 14 arranged so as to come into contact with the web 12 running continuously from below and apply a coating liquid. Yes. The application bar 14 is formed in a substantially columnar shape (or a substantially cylindrical shape), and is supported by the support member 16 so that the longitudinal direction thereof coincides with the width direction of the web 12.

  The upper surface of the support member 16 is a concave support surface 16S that supports the outer peripheral surface of the application bar 14, and the application bar 14 is rotatably supported in contact with the support surface 16S.

  As shown in FIG. 2, weir plates 18 and 20 are arranged on the upstream side and the downstream side of the support member 16, respectively. A predetermined gap is formed between each of the dam plates 18 and 20 and the support member 16. In particular, the gap between the upstream dam plate 18 and the support member 16 serves as a coating liquid supply path 22. Yes. The coating liquid sent from a coating liquid supply device (not shown) passes through the coating liquid supply path 22, and is sequentially scraped up by the rotation of the coating bar 14 and transferred to the web 12. In addition, on the upstream side of the contact portion between the web 12 and the application bar 14, a liquid reservoir 24 of the application liquid is formed between the web 12, the weir plate 20, and the application bar 14.

  A motor (rotary drive source) 26 is disposed on the side of the support member 16. As shown in FIG. 2, the shaft 26 </ b> S of the motor 26 is coupled to the rotary shaft 30 </ b> S of the bar drive shaft 30 via a belt 28. Here, a seamless belt is preferably used as the belt 28 from the viewpoint of preventing vibrations of the motor 26 from being transmitted to the bar drive shaft 30.

  Here, the motor 26 may be any motor that can be rotationally driven at a constant rotational speed, and various known motors can be used. For example, a DC motor (2-phase, 3-phase, 5-phase), AC motor, inverter motor, stepping motor, servo motor, or the like can be used, and a speed control motor, a torque control motor, or the like can be used depending on the purpose.

  As shown in FIG. 2, the bar drive shaft 30 is fixed to the support base 32 at two points by using fixing members 30A and 30B in the vicinity of both ends thereof.

  FIG. 4 is a plan view showing the installation position of the bar drive shaft 30 in relation to the center line of the application bar 14. As shown in FIG. 4, the angle θ formed by the rotation axis of the bar drive shaft 30 and the rotation axis of the application bar 14 is preferably within 1 °. The reason for this is that, at the position where the angle between the rotation axis of the bar drive shaft 30 and the rotation axis of the application bar 14 exceeds 1 °, the swirling of the bar increases, and the application formed on the web 12 This is because stepped unevenness occurs in the film. The outer diameter of the rotary shaft 30S of the bar drive shaft 30 is preferably a size slightly larger than the outer diameter of the application bar 14.

  A coupling 34 is provided between the bar drive shaft 30 and the application bar 14. With this coupling 34, the driving force transmitted from the motor 26 to the bar drive shaft 30 can be supplied to the application bar 14, and the slight axis between the rotation axis of the bar drive shaft 30 and the rotation axis of the application bar 14. It is possible to prevent the occurrence of rotational unevenness and vibration in the coating bar 14 by absorbing the deviation of the rotation.

  Here, as the coupling 34, one having a static torsion spring constant of 3400 N · m / rad or less can be preferably used. The reason for this is that when the static torsional spring constant exceeds 3400 N · m / rad, rotation unevenness and vibration due to a deviation between the rotation axis of the application bar 14 and the rotation axis of the motor 26 are easily transmitted to the application bar 14. This is because uneven rotation and vibration of the coating bar 14 cannot be prevented. More preferably, it is 980 N · m / rad or less.

  Among them, the metal spring coupling is a completely integrated coupling with a slit in a cylindrical material. For example, a product manufactured by Nabeya Bitech Co., Ltd. (product name: Capricon Mini MSX) is used. can do. The static torsion spring constant of this metal spring coupling is about 200 N · m / rad to 2200 N · m / rad.

  The bellows type flexible coupling is a coupling in which the hubs at both ends of a cylindrical material are connected by a metal bellows. Examples of commercially available products are those manufactured by Nabeya Bitech Co., Ltd. (product name: Capricon Mini MFB). ) Can be adopted. The static torsional spring constant of the bellows type flexible coupling is about 82 N · m / rad to 490 N · m / rad.

  The resin meshing type flexible coupling is a coupling in which a resin sleeve is arranged between the hubs at both ends of the cylindrical material, and this sleeve engages with the hubs at both ends. For example, those manufactured by Nabeya Bitech Co., Ltd. (product name: Capricon Mini MSF) can be used. The static torsional spring constant of the bellows type flexible coupling is about 4.4 N · m / rad to 85 N · m / rad.

  Couplings have the function of fastening discontinuous shafts and transmitting rotation. Other than the above, helical couplings, paraflex couplings, Bauman flex couplings, servo flex couplings, center flexes There are couplings, spaflex couplings, centax couplings, centmax couplings, magnet couplings, etc., as alternative expressions, disk type, slit type, Oldham type, sleep type, jaw type, bellows type, rigid type, etc. There is. These can also be used as needed.

  In addition, it is preferable that the swing of the tip connected to the application bar 14 of the bar drive shaft 30 is 100 μm or less. The reason is that if the runout exceeds 100 μm, coating unevenness occurs in the coating film formed on the web 12 during bar coating. Preferably, it is 50 μm or less, more preferably 10 μm or less.

  When the coating liquid is applied to the web 12 by the bar coating apparatus 10 according to the present embodiment having such a configuration, the web 12 is transported at a constant transport speed by a transport device (not shown).

  Further, the coating liquid is supplied from a coating liquid supply apparatus (not shown) with the coating bar 14 in contact with the web 12. Then, the coating bar 14 is rotated by the rotational driving force from the motor 26 to apply the coating liquid to the web 12.

  As described above, according to the present embodiment, since the belt 28 is interposed between the bar drive shaft 30 and the motor 26 and the power generated by the motor 26 is transmitted to the coating bar 14, the motor 26 Is not transmitted directly to the coating bar 14. For this reason, it is possible to suppress the swing of the coating bar 14 during bar coating, and no stepped unevenness occurs in the coating film formed on the web 12.

  Moreover, according to this Embodiment, since the motor 26 and the bar drive shaft 30 are not directly connected, the installation position of the motor 26 can be selected freely. For this reason, the freedom degree in design of the bar coating apparatus 10 can be improved.

  In addition, this invention is not restricted to the said structure, It can apply to all the apparatuses which apply | coat a coating liquid with a coating bar and comprise a liquid film.

  FIG. 5 is a schematic configuration diagram of a bar coating apparatus according to another embodiment of the present invention.

  Hereinafter, the same reference numerals are given to portions common to the above-described embodiment, and detailed description thereof is omitted.

  As shown in FIG. 5, in the bar coating apparatus 10 </ b> A according to the present embodiment, the bar drive shaft 30 is supported and fixed on a support base 32, and the motor 26 is supported and fixed on a support base 36.

  According to the bar coating apparatus 10A according to the present embodiment, since the bar drive shaft 30 and the motor 26 are supported and fixed on separate supports, vibration generated when the motor 26 is operated is transmitted to the coating bar 14. It is difficult to apply rotation unevenness or vibration to the coating bar 14 during bar coating. For this reason, coating unevenness due to rotation unevenness and vibration of the coating bar 14 does not occur on the web 12.

  Since other configurations and operational effects are the same as those of the above-described embodiment, a detailed description thereof will be omitted.

  Next, other components of the bar coating apparatus 10 will be described.

  The web 12 used in the present invention is generally polyethylene terephthalate (PET) having a width of 0.3 to 2 m, a length of 45 to 10,000 m, and a thickness of 2 to 200 μm, polyethylene-2,6- 2 carbon atoms such as naphthalate, cellulose diacetate, cellulose triacetate, cellulose acetate propionate, polyvinyl chloride, polyvinylidene chloride, polycarbonate, polyimide, polyamide and other plastic films, paper, polyethylene, polypropylene, ethylene butene copolymer A flexible strip made of paper or the like coated or laminated with 10 to α-polyolefins or a strip having a processed layer formed on the surface of the strip is used.

  As the conveyance speed of the web 12, a range of 10 m / min or more and 100 m / min or less is preferably adopted. Further, the different peripheral speed ratio (bar peripheral speed / web speed), which is the ratio between the peripheral speed of the coating bar 14 and the conveying speed of the web 12, is preferably in the range of 0.1 to 1.5.

The coating amount of the coating liquid to the web 12, 2mL / m ² or more 15 mL / m ² or less in the range can be preferably employed. Moreover, as a coating width of the coating liquid to the web 12, the range of 500 mm or more and 2000 mm or less is preferably employable. As the tension at the time of applying the coating liquid to the web 12, a range of 70 N / m or more and 1500 N / m or less can be preferably employed.

The coating solution is not limited to a non-Newtonian fluid such as a coating solution for an optical film or a magnetic tape, but may be a Newtonian fluid using a gelatin solution having a relatively low viscosity of the photographic photosensitive layer as a binder. The viscosity of the coating solution is preferably in the range of 0.8 cp to 10 cp (0.8 × 10 ⁻³ Pa · s to 10 × 10 ⁻³ Pa · s).

  The present invention is not limited to the above-described embodiment, and various changes can be made.

  For example, in the above embodiment, the rotational driving force of the motor 26 is transmitted to the bar drive shaft 30 via the belt. However, the present invention is not limited to this, and the rotational driving force of the motor 26 is transmitted to the planetary gear. It is also possible to transmit to the bar drive shaft 30 through.

  Further, in the above-described embodiment, the example in which the application bar for bar application is rotationally driven has been described. However, the present invention is not limited to this, and can be applied to the case where the scraping bar of the scraping device is rotationally driven. it can.

  The effects of the present invention will be further described with reference to examples.

(Example 1)
An optical compensation film was produced under the following conditions by the optical compensation film production line 80 incorporating the bar coating apparatus 10 of the present invention shown in FIG.

The web 12 was coated on a surface of triacetyl cellulose (Fujitack, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 100 μm with a 2 wt% solution of long chain alkyl-modified poval so as to be 25 ml per 1 m ² of film, and then at 60 ° C. And dried for 1 minute to form an alignment film resin layer. While this web 12 was sent out from the delivery machine 82 and conveyed at 50 m / min, the rubbing treatment device 86 rubbed the surface of the alignment layer resin layer to form an alignment film. The pressing pressure of the rubbing roller 88 in the rubbing treatment was 9.8 × 10 ⁵ Pa per cm ² of the alignment film resin layer, and the rotational peripheral speed was 5.0 m / sec.

  And the coating liquid was apply | coated using the bar coating apparatus 10 of this invention on the orientation film obtained by rubbing the resin layer for orientation films. The coating liquid was ethylene oxide-modified trimethylolpropane triacrylate (V # 360, Osaka Organic Chemical Co., Ltd.) with respect to a 4: 1 weight ratio of R (1) and R (2) of the discotic compound TE-8 shown below. Science Co., Ltd.) 10 wt%, cellulose acetate butyrate (CAB531-1, Eastman Chemical Co.) 0.6 wt%, photopolymerization initiator (Irgacure 907, Nippon Ciba Geigy Co., Ltd.) 3 1% by weight of a sensitizer (Kayacure DET-X, manufactured by Nippon Kayaku Co., Ltd.) was added and finally a 32% by weight methyl ethyl ketone solution of the mixture was obtained. To the liquid containing the liquid crystal compound, 0.3% by weight of a fluorosurfactant (fluoroaliphatic group-containing copolymer, Megafac F780, manufactured by Dainippon Ink Co., Ltd.) is added and used as a coating liquid. did.

And while supporting the wire bar 14 with a bar diameter of 10 mm and a wire diameter of 100 μm on a bar support surface 46 having a straightness of 0.1 mm per 1 m of the bar, the wire bar is driven while the web 12 is running at a running speed of 20 m / min. No. 14 was also rotated forward at the same speed, and the coating solution was applied onto the alignment film from the bar coating head so as to be 5 ml (wet film thickness 5 μm) per m ² of web.

  At this time, the rotational driving force of the motor 26 was transmitted to the bar driving shaft 30 via the belt 28 and then supplied to the wire bar 14. The bar drive shaft 30 and the wire bar 14 were coupled via a coupling (MCGLC 32-10-10: manufactured by MISUMI). Further, the angle between the rotation axis of the bar drive shaft 30 and the rotation axis of the wire bar 14 is 0 °, and the deflection of the tip connected to the wire bar 14 of the bar drive shaft 30 is 0.12 mm. there were. In measuring the deflection of the tip of the bar drive shaft 30 connected to the wire bar 14, the location at the tip of 2 mm was measured with a test indicator (TI-113H: manufactured by Mitutoyo Corporation).

  The outer diameter of the rotating shaft S of the bar drive shaft 30 was φ40 mm.

  The web 12 coated with the coating solution is passed through a drying zone 92 adjusted to 100 ° C. and a heating zone 94 adjusted to 130 ° C. to form a nematic phase. While continuously transporting the coated web 12, the surface of the liquid crystal layer was irradiated with ultraviolet rays by an ultraviolet lamp 96. Thereby, an optical compensation film was produced.

(Example 2)
An optical compensation film was produced under the same conditions as in Example 1 except that the deflection of the tip connected to the wire bar 14 of the bar drive shaft 30 was 0.11 mm.

(Example 3)
An optical compensation film was produced under the same conditions as in Example 1 except that the deflection of the tip connected to the wire bar 14 of the bar drive shaft 30 was 0.10 mm.

Example 4
An optical compensation film was manufactured under the same conditions as in Example 1 except that the deflection of the tip connected to the wire bar 14 of the bar drive shaft 30 was 0.09 mm.

(Example 5)
An optical compensation film was produced under the same conditions as in Example 1 except that the deflection of the tip connected to the wire bar 14 of the bar drive shaft 30 was 0.05 mm.

(Example 6)
An optical compensation film was manufactured under the same conditions as in Example 1 except that the deflection of the tip connected to the wire bar 14 of the bar drive shaft 30 was 0.01 mm.

(Example 7)
The angle between the rotation axis of the bar drive shaft 30 and the rotation axis of the wire bar 14 is 1 °, and the swing of the tip connected to the wire bar 14 of the bar drive shaft 30 is 0.01 mm. Except for the above, an optical compensation film was produced under the same conditions as in Example 1.

(Example 8)
The angle between the rotation axis of the bar drive shaft 30 and the rotation axis of the wire bar 14 is 1 °, and the deflection of the tip connected to the wire bar 14 of the bar drive shaft 30 is 0.10 mm. Except for the above, an optical compensation film was produced under the same conditions as in Example 1.

Example 9
The angle between the rotation axis of the bar drive shaft 30 and the rotation axis of the wire bar 14 is 1 °, and the deflection of the tip connected to the wire bar 14 of the bar drive shaft 30 is 0.11 mm. Except for the above, an optical compensation film was produced under the same conditions as in Example 1.

(Example 10)
The angle between the rotation axis of the bar drive shaft 30 and the rotation axis of the wire bar 14 is 0.5 °, and the deflection of the tip connected to the wire bar 14 of the bar drive shaft 30 is 0.05 mm. An optical compensation film was produced under the same conditions as in Example 1 except that there was.

(Example 11)
The angle between the rotation axis of the bar drive shaft 30 and the rotation axis of the wire bar 14 is 1 °, and the swing of the tip connected to the wire bar 14 of the bar drive shaft 30 is 0.05 mm. Except for the above, an optical compensation film was produced under the same conditions as in Example 1.

(Example 12)
The angle between the rotation axis of the bar drive shaft 30 and the rotation axis of the wire bar 14 is 2 °, and the swing of the tip connected to the wire bar 14 of the bar drive shaft 30 is 0.05 mm. Except for the above, an optical compensation film was produced under the same conditions as in Example 1.

(Comparative Example 1)
The motor 26 and the bar drive shaft 30 are directly connected without a belt, and the swinging of the tip connected to the wire bar 14 of the bar drive shaft 30 is 0.05 mm under the same conditions as in the first embodiment. An optical compensation film was produced.

(Summary)
The evaluation items are uneven coating that occurs in the width direction of the web 12 in one rotation period of the wire bar 14, uneven unevenness caused by the flow of the coating liquid, uneven flow, and longitudinal direction of the web 12 (conveying direction). ) Was visually evaluated as a straight stripe.

  In the quality evaluation of the optical compensation film, the level that satisfies the manufacturing quality level is ◎, the level that satisfies the manufacturing quality is ○, the level that satisfies the product level is slightly uneven, and the manufacturing quality is not satisfied A four-level evaluation was performed with x indicating a level of failure.

  The evaluation results are shown in Table 1.

  As shown in Examples 1 to 12 in Table 1, when the bar coating is performed by transmitting the rotational driving force of the motor 26 to the bar driving shaft 30 via the belt 28 and rotating the wire bar 14, It can be seen that a coating film satisfying the product level can be obtained.

  On the other hand, as shown in Comparative Example 1 in Table 1, when the bar coating is performed by rotating the wire bar 14 by transmitting the rotational driving force of the motor 26 directly to the bar driving shaft 30 without passing through the belt 28. It can be seen that only a coating film that does not satisfy the product level can be obtained.

  Further, in Examples 3 to 8 and Examples 10 and 11, the swing of the tip connected to the wire bar 14 of the bar driving shaft 30 is 0.10 mm (100 μm) or less, and the rotation of the bar driving shaft 30 is performed. It can be seen that when the angle between the shaft core and the rotation shaft core of the wire bar 14 is 1 ° or less, a coating film satisfying the product level can be obtained without step unevenness.

  In Examples 1, 2, and 9, the angle between the rotation axis of the bar drive shaft 30 and the rotation axis of the wire bar 14 is 1 ° or less, but is connected to the wire bar 14 of the bar drive shaft 30. Since the deflection of the tip exceeds 0.10 mm (100 μm), only a coating film slightly inferior in product level can be obtained as compared with the coating films obtained in Examples 3 to 8 and Examples 10 and 11. I understand that.

  In Example 12, the whirling of the tip connected to the wire bar 14 of the bar drive shaft 30 is 0.10 mm (100 μm) or less, but the rotation axis of the bar drive shaft 30 and the rotation axis of the wire bar 14 Since the angle between them exceeds 1 °, it can be seen that only a coating film slightly inferior in terms of product level can be obtained as compared with the coating films obtained in Examples 3 to 8 and Examples 10 and 11.

  As described above, in order to obtain a coating film having no problem as a product level without unevenness by bar coating, the rotational driving force of the motor 26 is transmitted to the bar driving shaft 30 via the belt 28 and the wire bar 14 is rotated. The swivel of the tip connected to the wire bar 14 of the wiper drive shaft 30 is 0.10 mm (100 μm) or less, and the angle between the rotation axis of the bar drive shaft 30 and the rotation axis of the wire bar 14 It was shown that it is effective to set the angle to 1 ° or less.

Schematic configuration diagram showing a first embodiment of a bar coating apparatus according to the present invention Enlarged schematic view of the vicinity of the coating bar of the bar coating apparatus according to the present embodiment Magnified schematic view near the bar drive shaft of the bar coating apparatus according to the present embodiment Plan view showing the installation position of the bar drive shaft in relation to the rotation axis of the application bar Schematic configuration diagram of a bar coating apparatus according to the present embodiment Explanatory drawing of the production line of the optical compensation sheet incorporating the bar coating apparatus of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Bar coating device, 12 ... Web, 14 ... Coating bar, 16 ... Support member, 18, 20 ... Dam plate, 22 ... Coating liquid supply path, 24 ... Liquid reservoir, 26 ... Motor (rotation drive source), 28 ... Belt, 30 ... Bar drive shaft, 32 ... Support base, 34 ... Coupling, 36 ... Support base

Claims (7)

In a bar coating apparatus that applies a coating solution with a coating bar on a traveling support,
A rotational drive source that generates rotational drive force;
A bar drive shaft for transmitting rotation of the rotary drive source to the application bar;
In a bar coating apparatus having
The bar coating apparatus according to claim 1, wherein the rotational driving force of the rotational driving source is transmitted to the bar driving shaft via a belt.   The bar coating apparatus according to claim 1, wherein a swing of a tip connected to the coating bar of the bar driving shaft is 100 μm or less.   The bar coating apparatus according to claim 1, wherein the bar driving shaft is supported at two or more points.   The bar coating apparatus according to claim 1, wherein the bar driving shaft is coupled to the coating bar via a coupling.   The bar coating apparatus according to any one of claims 1 to 4, wherein a static torsion spring constant of the coupling is 3400 N · m / rad or less.   The bar coating apparatus according to any one of claims 1 to 5, wherein the rotation axis of the bar drive shaft intersects with the rotation axis of the coating bar at an angle of 1 ° or less. In a bar coating method in which the coating liquid is transferred and applied to a belt-like support that travels through the coating bar while rotating the coating bar with a rotation drive source,
A bar coating method characterized in that the rotation of the rotational drive source is supplied to a coating bar via a belt.

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