JP5622434B2 - Coating roll for thin film formation, coating method and coating apparatus - Google Patents

Description

  The present invention relates to a coating roll for forming a thin film, a coating method, and a coating apparatus for forming an ultrathin film having a thickness of 1 μm or less after drying.

  Conventionally, Patent Document 1 is known as a roll coating apparatus that forms a thin and uniform coating film on a workpiece. This roll coating apparatus relates to a technique for rotating a roller through a workpiece between a pair of rollers in which the roller is pressed against a pressure roller, and transferring the coating liquid applied to the coating roller or workpiece to the workpiece. Here, the coating roller has a structure in which a sponge layer having a constant thickness and a non-adhesive / non-adsorbing tube film having a smooth surface are sequentially coated on the outer periphery of a core made of steel or the like. The pressing roller has a configuration in which an outer peripheral layer smoothed by processing with a fluororesin is provided on the outer periphery of a core made of steel or the like.

Japanese Patent No.3052127

  However, when roll coating is performed by the application roller used in the roll coating apparatus, the sponge layer of the application roller is deformed due to the pressure of the pressure roller, and the tube coated on the outer periphery of the sponge layer against the deformation. The film cannot follow and wrinkles occur on the roller surface. As a result, a wrinkled pattern occurs on the coating film formed on the surface of the workpiece, and it is difficult to obtain a uniform coating surface unless the drying speed and leveling performance of the coating film are adjusted well. was there.

  The present invention has been made in consideration of such circumstances, and even if the coating film formed on the object to be processed is an extremely thin film having a thickness of 1 μm or less after drying, it is uniform on the surface of the object to be processed. It aims at providing the coating roll for thin film formation which can form a coating film, the coating method, and a coating device.

A coating roll according to the present invention is a coating roll for forming a thin film on an object to be processed using a coating solution for forming a thin film, and a core and a sponge provided on the outer periphery of the core And a solid layer provided on the outer periphery of the sponge layer, and a surface layer provided on the outer periphery of the solid layer and having non-adhesiveness and non-adhesiveness to the coating liquid. And

  Further, the coating method according to the present invention is a coating method for forming a thin film on an object to be processed using the coating roll for forming a thin film, and after applying a coating liquid for forming a thin film on the coating roll or the object to be processed. A thin film is formed on the object to be processed by passing the object to be processed in a state where the coating roll and the object to be processed are in pressure contact with each other.

  Furthermore, the roll coating apparatus according to the present invention comprises the coating roll for forming a thin film, a pressure contact means for passing the processing object in pressure contact with the coating roll, and a coating film forming coating on the coating roll or the processing object. And a coating liquid pouring device for pouring out the liquid.

  According to the present invention, a uniform coating film can be formed on the surface of an object to be processed even if it is an ultrathin film having a thickness of 1 μm or less after drying. A coating roll for forming a thin film, a coating method, and a coating apparatus can be provided.

Explanatory drawing of the roll coating device which concerns on Example 1 of this invention. Explanatory drawing of the roll coating device which concerns on Example 2 of this invention. Explanatory drawing of the image data by the roll coating device of FIG. Explanatory drawing of the image data by the roll coating device of FIG. Explanatory drawing of the image data by the conventional roll coating device. Explanatory drawing which shows the other example which press-contacts a to-be-processed object to a coating roll in the roll coating device of this invention. In the roll coating apparatus of this invention, explanatory drawing which shows the further another example which press-contacts a to-be-processed object to a coating roll.

Hereinafter, the present invention will be described in more detail.
In the present invention, when the coating roll comes into contact with the object to be processed, the sponge layer is deformed by the influence of the external pressure due to the pressure contact, so that the contact surface can be equalized and the unevenness of the object to be processed is reduced. be able to.

  In the present invention, the sponge layer is preferably soft and uniformly deformed. Examples of the material for the sponge layer include silicone rubber, polyvinyl alcohol (PVA), urethane, and butyl rubber. Moreover, although the thickness of a sponge layer is based also on a roll diameter, 3-20 mm is preferable, More preferably, it is 5-15 mm, More preferably, it is 5-10 mm. Here, if the thickness is less than 3 mm, the amount of deformation at the time of contact is small, and the effect of the sponge layer cannot be obtained. On the other hand, when the thickness exceeds 20 mm, deformation at the time of contact becomes too large, so that the contact surface becomes too large and the coated surface is deteriorated.

  In the present invention, the solid layer is provided in order to suppress wrinkling of the surface layer due to the deformation of the sponge layer (change in circumferential distance). The solid layer is harder than the sponge layer and is more rigid than the outermost layer (surface layer). Need to be soft. As the hardness of the solid layer, the hardness of a general rubber material can be applied, but it is 10 to 95 ° (JISA), preferably 30 to 90 ° (JISA), more preferably from the viewpoint of the effect of the above-described function. It is 40-80 degrees (JISA). Here, if the hardness is less than 10 °, the generation of wrinkles in the surface layer cannot be suppressed, and if the hardness exceeds 95 °, the effect of suppressing wrinkles due to the deformation of the sponge layer is not exhibited.

  The thickness of the solid layer is preferably 0.2 to 3 mm for the following reason. That is, when the thickness is less than 0.2 mm, it is not possible to suppress excessive deformation of the sponge layer, and a wrinkled pattern is generated on the coating film formed on the surface of the workpiece. On the other hand, if the thickness exceeds 3 mm, the influence of the stress of the solid layer becomes too great, and the restoration effect by the sponge layer is not exhibited and a uniform film cannot be obtained.

  As the material of the solid layer, for example, any rubber such as silicone rubber, acrylonitrile / butadiene rubber, ethylene propylene rubber, fluorine rubber, urethane rubber, chloroprene rubber, epichlorohydrin rubber, natural rubber and the like can be used. Moreover, you may mix | blend well-known additives, such as a vulcanizing agent, a vulcanization adjuvant, a vulcanization accelerator, an anti-aging agent, a plasticizer, a filler, with the rubber used for a solid layer as needed.

  In the present invention, the material of the surface layer provided on the outer periphery of the solid layer may be basically any material that is non-adhesive and non-adhesive and resistant to the coating liquid. Non-adhesive materials such as tetrafluoroethylene resin (PTFE), tetrafluoroethylene perfluoroalkyl vinyl ether copolymer resin (PFA), tetrafluoroethylene hexafluoropropylene copolymer resin (FEP), etc. , Non-adhesive, inert, and smooth fluororesins, metals, metal oxides, and the like. The surface layer may be conductive or insulating. The surface layer may be a tube or a coat layer. The thickness of the surface layer is desirably 0.2 mm or less for the following reason. That is, if the thickness exceeds 0.2 mm, the hardness of the surface layer itself is too high, so that the effect of pressure equalization when contacting the object to be processed cannot be obtained sufficiently.

Next, specific examples of the present invention will be described.
Example 1
FIG. 1 shows an example of a roll coating apparatus provided with a thin film-forming coating roll according to the present invention.
In the figure, reference numeral 1 denotes a thin film-forming coating roll, which is paired with a backup roll 3 disposed opposite to the object 2 to be processed. The coating roll 1 includes a silicone rubber sponge layer 5 having a thickness of 7 mm and a hardness of 25 ° (Asker C), a solid layer 6 having a thickness of 1 mm and a hardness of 40 ° (JISA), and an outer periphery of a core body 4 made of steel. A non-adhesive and non-adhesive tube layer (surface layer) 7 having a thickness of 0.05 mm is sequentially formed. Here, the solid layer 6 is made of silicone rubber, and the tube layer 7 is made of PFA. On the other hand, the backup roll 3 includes a core body 8 made of a steel material and a smoothed fluororesin surface layer 9 formed on the outer periphery of the core body 8. In the vicinity of the coating roll 1, a coating liquid dispensing device 10 that dispenses a coating liquid for forming a coating film on the tube layer 7 of the coating roll 1 is disposed. The coating liquid dispensing apparatus 10 contains a coating liquid 11 and a tank 13 having a nozzle 12 at the tip, and a liquid supply such as a pump for supplying the coating liquid 11 in the tank 13 to the tube layer 7 of the coating roll 1. Means (not shown) and a drive mechanism (not shown) such as a piston for moving the nozzle 12 so as to approach the tube layer 7 are provided.

  In order to form a thin film on the workpiece 2 using the roll coating apparatus having such a configuration, the following process is performed. That is, first, in a state where the workpiece 2 is sandwiched between the coating roll 1 and the backup roll 3, the nozzle 12 of the coating liquid dispensing apparatus 10 is brought close to the rotating coating roll 1 by the drive mechanism, and the tank 13 is driven by the liquid supply means. The inner coating solution is applied to the tube layer 7 of the coating roll 1. Thereafter, the coating liquid is transferred by press-contacting the application roll 1 and the object to be processed via the object to be processed 2 by pressing the backup roll 3, thereby forming a uniform and thin film on the object to be processed 2. The arrow A indicates the moving direction of the workpiece.

  According to the roll coating apparatus according to Example 1, by providing the thin film forming coating roll 1 provided with a solid layer 6 having a thickness of 1 mm and a hardness of 40 ° between the silicone rubber sponge layer 5 and the tube layer 7, It is possible to suppress the occurrence of wrinkle-like patterns due to deformation of the tube layer 7 on the workpiece 2, and also due to unevenness and inclination of the workpiece 2, pressure unevenness between rolls such as pressing of the opposing rolls 1, 3. The coating thickness unevenness can be suppressed, and the coating film after drying can be formed in a uniform and extremely thin thickness of 1 μm or less.

(Example 2)
FIG. 2 shows an example of a roll coating apparatus provided with a thin film forming coating roll according to the present invention. However, the same members as those in FIG.
The roll coating apparatus of the second embodiment is the same as that of the first embodiment except that the coating liquid 11 is applied to the workpiece 2 and then the coating liquid is thinned by the coating roll 1 and the backup roll 3. It is the same composition as.
According to the second embodiment, there are almost the same effects as the first embodiment.

(Comparative example)
The coating roll for forming a thin film according to the comparative example has the same configuration as that of the roll of Example 1 except that the solid layer is excluded from the roll of Example 1. The method for forming a thin film on the object to be processed is the same as in the case of the first embodiment.

A thin film was formed on a glass substrate as an object to be processed using a roll coating apparatus including the thin film forming coating rolls according to Examples 1 and 2 and Comparative Example, and the thickness unevenness of the thin film was evaluated by image processing. However, the results shown in FIGS. 3 to 5 were obtained. In addition, what diluted the organic dye with the organic solvent so that solid content might be 30 wt% was used for the coating liquid. The coated thin film is air-dried as it is, the thickness after drying is measured using an atomic force microscope (AFM), and the image information on the coated surface is converted into data, and the dark / light portions are binarized. The thickness distribution of the formed film was evaluated. Here, since the dye is used for the coating liquid, the light-colored portion has a small film thickness, and the dark-colored portion has a large film thickness. This is confirmed from the comparison between the actual measurement value by AFM and the measurement value by absorption spectrometry. 3-5, the horizontal direction (arrow B direction) of a paper surface respond | corresponds to the rotation direction of a roll, and the thick part 14 is corresponded to a horizontal strip-like wrinkle. In fact, the average value of the coating thickness of the thin film by AFM according to Examples 1 and 2 and the comparative example, the area of the thin film portion ( white portion), the thick portion ( black portion), and the area ratio of the black portion to the whole are obtained. The results were as shown in Table 1 below. In FIGS. 3 to 5, portions with extremely different thicknesses are detected, and in this case, processing is performed so that light-colored portions (thick-thickness portions) become white .

From the above image processing test, it can be seen that in FIGS. 3 and 4 corresponding to the first and second embodiments, the region of the thick portion 14 is remarkably smaller than that in FIG. 5 corresponding to the comparative example. In the case of the present invention, the presence of the solid layer having the thickness and hardness as described above suppresses the generation of wrinkle patterns as compared with the comparative example, and as a result, the thickness uniformity of the coating film is greatly increased. It can be seen that it has been improved. In the image processing of this test, only specific colors were poured out, edge detection was performed, contrast was adjusted, and binarization was performed to obtain images as shown in FIGS. This image corresponds to an image obtained by clearly separating a dark portion and a light portion of the coated material.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

  Specifically, in the above embodiment, the case where the non-adhesive tube layer is provided on the solid layer has been described. However, the present invention is not limited to this, and a non-adhesive coating layer may be provided. Further, the thickness and hardness of the solid layer are not limited to the values described in the above embodiments. Furthermore, in the roll coating device, a drying device including a heater or the like for drying the thin film formed on the transported object may be disposed on the downstream side of the coating roll and the backup roll.

  Furthermore, in the said Example, although the case where a coating roll and a to-be-processed object were press-contacted using a coating roll and a backup roll was described, it is not restricted to this, For example, as shown in FIG. Two stretching rolls 16a and 16b are disposed and the workpiece 2 is pressed between the coating roll 1 and the stretching rolls 16a and 16b, or under the thin film forming coating roll 1 as shown in FIG. The case where the mount 17 is provided, the to-be-processed object 2 is pressed-contacted by pressing the application roll 1 to the mount 17 side is mentioned.

DESCRIPTION OF SYMBOLS 1 ... Coating roll for thin film formation, 2 ... To-be-processed object, 3 ... Backup roll, 4, 8 ... Core body, 5 ... Silicone rubber sponge layer, 6 ... Solid layer, 7 ... Tube layer, 9 ... Surface layer, 10 ... Coating liquid coating apparatus, 12 ... nozzle, 14 ... thick part, 15 ... thin film part.

Claims (3)

A thin film forming coating roll for forming a thin film on an object to be processed using a thin film forming coating liquid, a core body, a sponge layer provided on an outer periphery of the core body, and an outer periphery of the sponge layer A coating roll for forming a thin film, comprising: a solid layer provided on the surface; and a surface layer provided on the outer periphery of the solid layer and having non-adhesiveness and non-adhesiveness to the coating solution.   A coating method for forming a thin film on an object to be processed using the coating roll for forming a thin film according to claim 1, wherein a coating liquid for forming a thin film is applied to the coating roll or the object to be processed, and then the coating roll and the object to be processed. A coating method, wherein a thin film is formed on an object to be processed by passing the object to be processed in a state where the object is in pressure contact.   2. A coating roll for forming a thin film according to claim 1, press-contacting means for passing an object to be processed in pressure contact with the application roll, and a coating liquid for pouring a coating liquid for forming a coating film on the coating roll or the object to be processed. A roll coating apparatus comprising: a pouring device.

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