JP4755407B2 - Coating method - Google Patents

Description

  The present invention relates to a coating method for obtaining a coating surface by blowing air to a traveling sheet-like material.

  In recent years, coating technology has been used in display materials, video display fields such as functional films, information recording fields such as magnetic tapes, paper fields such as inkjet paper, electrical and electronic fields such as thin film batteries and electronic circuit boards, eyeglass lenses, etc. It is used in many fields such as optical related fields such as functional fibers such as water repellency, waterproofing and deodorization. Also, various coating methods have been created in order to cope with various combinations of objects to be coated and coating liquids.

  On the other hand, in recent years, various processes are often connected before and after the coating process, and there are many cases where the coating speed is limited due to the relationship between the preceding and subsequent processes. For example, as a post process of the coating process, as shown in Patent Document 1, opposed belt surfaces of two endless belts arranged so that opposed metal belt surfaces run in the same direction at the same speed; A polymerizable raw material is supplied from one end to a space surrounded by a continuous gasket that runs between the belt surfaces on both sides of the belt, and the polymerizable raw material is fed along with the running of the belt in the heating zone. When it has a process of solidifying and taking out the plate-like polymer from the other end, the solidification rate of the polymerizable raw material is slower than the coating rate, so that the coating rate is limited.

  In addition, as a pre-process of the coating process, there may be a process of treating the surface of the object to be coated for the purpose of improving the surface wettability of the object to be coated.

  When such a separate process and a coating process are connected, the coating speed is often limited to 10 m / min or less due to the convenience of the separate process.

  However, the conventional coating technique focuses only on how to increase the coating speed while maintaining the coating thickness, and the optimum coating under low-speed coating conditions where the coating speed is 10 m / min or less. The proposal of the construction method has not been made until now.

  In recent years, many coating technologies have been utilized in the high-tech industry. However, the higher the technology, the more expensive the coated material, and the greater the damage caused by contact between the coating device and the coated material. turn into. In addition, if the object to be coated has a high rigidity such as metal or glass, contact troubles between the coating apparatus and the object to be coated may damage not only the object to be coated but also the coating apparatus. The damage will be extremely large. Therefore, there is a demand for a coating method that has high coating accuracy and has a low risk of damaging the workpiece.

  As a coating method with a low risk of damaging an object to be coated, there is an air knife coat. Specifically, for example, using an air nozzle as shown in Patent Document 2, a coating liquid larger than the final coating amount is supplied onto the object to be coated, and then from the air knife to the surface of the object to be coated. This is a method in which high-pressure air is blown toward the surface to scrape off excess coating liquid. As shown in FIG. 2, the excess coating liquid scraped off is collected by a catch pan 7 installed below the air knife (air nozzle 3). In the case of air knife coating, the distance between the lip at the tip of the air knife and the object to be coated can generally be set to 0.8 mm or more. For example, the distance in the die coating method is about several tens μm at most. This is advantageous in that the contact risk between the workpiece and the lip is low.

However, in the conventional air knife coating, the coating speed is generally in the range of 100 m / min to 1000 m / min, and the coating behavior at a lower speed condition, particularly at a coating speed of 10 m / min or less is specific. There has never been shown in. Furthermore, since the excess coating solution is scraped off to determine the final coating amount, a coating solution recovery facility such as a so-called catch pan is required, which not only makes the facility huge, but the coating solution is harmful to the human body. In such a case, the excess liquid scraped off may scatter to the surroundings, resulting in deterioration of the working environment.
Japanese Patent Publication No. 47-33495 Japanese Patent Publication No. 36-9437

  The present invention has been made to solve the above-described problems. That is, an object of the present invention is to provide a coating method that has a low risk of damage to an object to be coated under low-speed coating conditions of 10 m / min or less and does not require recovery of the coating liquid.

  As a result of repeating diligent experiments to achieve the above object, the present inventors have determined that if the object to be coated is a sheet-like object having high rigidity, it remains in a flat state without causing a height difference in the width direction. It was confirmed that it was easy to run in the direction. On top of that, while supplying the coating liquid from above the sheet-like material while running the sheet-like material in the horizontal direction, if air is blown with an air knife, the damming effect of the coating liquid exerted by the pressure of the blowing air It is possible to create a pool of coating liquid over the entire coating width upstream of the air nozzle, and this can provide a uniform coating surface in the width direction, and this phenomenon Was found only at a very low coating speed of 10 m / min or less, and the present invention was completed.

That is, the present invention provides a coating surface is mirror-polished, so thick running the sheet is a stainless steel plate of 1.0mm or more in substantive horizontally at a speed of 0.1m / min~10m / min After supplying the coating liquid from above the sheet-like material, air is blown onto the sheet-like material from the air nozzle, so that the coating liquid is uniformly accumulated over the entire coating width upstream of the air nozzle. It is a coating method which does not require collection | recovery of the excess coating liquid which obtains a coating surface.

According to the coating method of the present invention, the coating liquid is pooled on the upstream side by air blowing under a low-speed coating condition, and thereby the coating is uniformly applied in the width direction without damaging the workpiece. A work surface can be formed, and there is no need to recover the surplus coating liquid. Therefore, it is very useful in a variety of applications where it is necessary to form a coated surface on the surface of the metal sheet.

  FIG. 1 is a schematic view showing an example of the coating method of the present invention. As shown in this figure, the sheet-like object 1 (the object to be coated) travels in the horizontal direction, and the coating liquid is supplied to the upper surface of the sheet-like object 1 from the coating liquid supply unit 2 located above the sheet-like object 1. . In the conventional air knife coating method described above, a coating liquid in an amount larger than the final coating amount is supplied here, but in the present invention, the target coating amount, that is, the same amount as the final coating amount. Supplying is enough.

  The supply method in the coating liquid supply unit 2 may be a simple method in which one hollow pipe or a plurality of hollow pipes are arranged in the width direction, and one or a plurality of spray nozzles for spraying to draw a certain area. The one arranged in the width direction may be used. When the spray nozzle is used, it is preferable to adjust the average droplet diameter of the sprayed coating liquid to 0.1 mm or more so that the coating liquid is not scattered by the airflow from the air nozzle 3 located downstream. Further, a method of supplying a coating liquid by arranging a slit die in the width direction may be used. The attachment position of the coating liquid supply unit 2 is preferably separated from the surface of the sheet 1 by 10 mm or more. In the present invention, the width direction refers to the direction orthogonal to the traveling direction of the sheet-like object 1 (the object to be coated), and the longitudinal direction refers to the traveling direction of the sheet-like object 1. Further, upstream and downstream are meanings when the traveling of the sheet-like object 1 is viewed as a flow.

  Here, even if an uncoated part exists at the stage where the coating liquid is supplied onto the sheet-like material 1 from the coating liquid supply unit 2, as will be described in detail later, Uncoated parts can be lost.

  The coating liquid used in the present invention is not particularly limited, and any non-aqueous or aqueous coating liquid can be used. The viscosity of the coating liquid is usually preferably in the range of 1 mPa · s to 5000 mPa · s.

  Examples of the non-aqueous coating liquid include acrylic acid esters such as methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate; methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, Methacrylic acid esters such as 2-ethylhexyl methacrylate; and polymerizable monomers such as vinyl acetate, acrylonitrile, methacrylonitrile, and styrene.

  In particular, poly (meth) acrylates of polyhydric alcohols can be suitably used. Specific examples thereof include diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, and 1.4. -Butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate , Pentaglycerol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, glycerin tri (meth) acrylate, dipenta Thritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tripentaerythritol tetra (meth) acrylate, tripentaerythritol penta (meth) acrylate , Tripentaerythritol hexa (meth) acrylate, tripentaerythritol hepta (meth) acrylate; malonic acid / trimethylolethane / (meth) acrylic acid, malonic acid / trimethylolpropane / (meth) acrylic acid, malonic acid / glycerin / (Meth) acrylic acid, malonic acid / pentaerythritol / (meth) acrylic acid, succinic acid / trimethylolethane / (meth) acrylic acid, succinic acid / trimethyl Propane / (meth) acrylic acid, succinic acid / glycerin / (meth) acrylic acid, succinic acid / pentaerythritol / (meth) acrylic acid, adipic acid / trimethylolethane / (meth) acrylic acid, adipic acid / trimethylolpropane / (Meth) acrylic acid, adipic acid / glycerin / (meth) acrylic acid, adipic acid / pentaerythritol / (meth) acrylic acid, glutaric acid / trimethylolethane / (meth) acrylic acid, glutaric acid / trimethylolpropane / (Meth) acrylic acid, glutaric acid / glycerin / (meth) acrylic acid, glutaric acid / pentaerythritol / (meth) acrylic acid, sebacic acid / trimethylolethane / (meth) acrylic acid, sebacic acid / trimethylolpropane / ( (Meth) acrylic acid, sebacic acid / Glycerin / (meth) acrylic acid, sebacic acid / pentaerythritol / (meth) acrylic acid, fumaric acid / trimethylolethane / (meth) acrylic acid, fumaric acid / trimethylolpropane / (meth) acrylic acid, fumaric acid / glycerin / (Meth) acrylic acid, fumaric acid / pentaerythritol / (meth) acrylic acid, itaconic acid / trimethylolethane / (meth) acrylic acid, itaconic acid / trimethylolpropane / (meth) acrylic acid, itaconic acid / glycerin / (Meth) acrylic acid, itaconic acid / pentaerythritol / (meth) acrylic acid, maleic anhydride / trimethylolethane / (meth) acrylic acid, maleic anhydride / trimethylolpropane / (meth) acrylic acid, maleic anhydride / Glycerin / (meth) acrylic acid, anhydrous Condensate by a combination of inic acid / pentaerythritol / (meth) acrylic acid, etc .; trimethylolpropane toluylene diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, xylene diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate) , Isophorone diisocyanate, trimethylhexamethylene diisocyanate and the like, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-methoxypropyl (meth) acrylate, N-methylol (meth) acrylamide, N-hydroxy (meth) acrylamide, 1,2,3-propanetriol-1,3-di (meth) acrylate, 3-acrylo Urethane (meth) acrylate obtained by reacting yloxy-2-hydroxypropyl (meth) acrylate or the like with 3 mol or more per molecule of isocyanate by a conventional method; di (meth) of tris (2-hydroxyethyl) isocyanuric acid Examples include poly [(meth) acryloyloxyethyl] isocyanurate such as acrylate and tri (meth) acrylate, and conventionally known epoxy polyacrylate and urethane polyacrylate.

  These can be used individually by 1 type or in mixture of 2 or more types. Further, a solvent such as acetone, methanol, ethanol, isopropanol, methyl ethyl ketone, n-hexane, cyclohexane or the like can be appropriately added for the purpose of adjusting the viscosity.

  Moreover, a polymerization initiator can also be added. Specific examples thereof include tert-hexyl peroxypivalate, tert-hexyl peroxy-2-ethylhexanoate, di-isopropyl peroxydicarbonate, tert-butyl neodecanoate, tert-butyl peroxy Organic peroxides such as pivalate, lauroyl peroxide, benzoyl peroxide, tert-butyl peroxyisopropyl carbonate, tert-butyl peroxybenzoate, dicumyl peroxide, di-tert-butyl peroxide; 2,2'- Azobis (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (1-cyclohexanecarbonitrile), 2,2′-azobis (2,4,4- Azo compounds such as trimethylpentane); and the like. Further, specific examples of the photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, acetoin, butyroin, toluoin, benzyl, benzophenone, p-methoxybenzophenone, and 2,2-diethoxy. Acetophenone, α, α-dimethoxy-α-phenylacetophenone, methylphenylglyoxylate, ethylphenylglyoxylate, 4,4′-bis (dimethylamino) benzophenone, 2-hydroxy-2-methyl-1-phenylpropane- Carbonyl compounds such as 1-one; sulfur compounds such as tetramethylthiuram monosulfide and tetramethylthiuram disulfide; Furthermore, auxiliary agents such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide and benzoyldiethoxyphosphine oxide, inorganic fillers, and the like can be added as appropriate.

The material of the sheet 1 which is an object to be coated was to use stainless steel. For example, austenitic stainless steel, etc. martensitic stainless steel and the like. Also, to use the surface of the coating side those polished. In order for the sheet-like material to keep running in a horizontal state, it is preferable that the sheet-like material has high rigidity. In particular, a metal sheet is generally preferable because it has a relatively high rigidity even if it is thin. The thickness of the sheet is Ru der least 1.0 mm. Moreover, in order to maintain the flatness of the sheet-like material in the horizontal direction, tension can be applied along the traveling direction of the sheet-like material.

  As shown in FIG. 1, the coating liquid supplied onto the sheet-like material 1 traveling substantially in the horizontal direction is supplied to a pool 5 formed over the entire coating width by the damming effect of the air nozzle 3. The On the other hand, a certain amount of the coating liquid as a coating surface 4 steadily moves from the pool 5 together with the sheet-like material from directly below the air nozzle 3 toward the downstream. The free surface of the reservoir 5 is constantly waved by the air ejected from the air nozzle 3, but if this wave becomes intense, the wave shape is reflected on the coating surface 4, which is not preferable in appearance. As a result of intensive studies, the inventors of the present invention have an extremely large influence on the coating surface 4 due to the undulation in the vicinity of the position 8 where the coating liquid reservoir comes into contact with the sheet-like material, and the amount of the reservoir 5 is reduced per minute of the coating liquid. It is found that by adjusting the amount to be larger than the supply amount, the position 8 where the coating liquid reservoir contacts the sheet-like material is sufficiently separated from the air nozzle 3 to reduce the undulation, and the coating surface 4 having a good appearance can be obtained. It was. Here, “position 8 where the coating liquid reservoir contacts the sheet-like material” means that when the sheet-like material 1 travels from the upstream side to the downstream side, the traveling sheet-like material 1 is applied first. It means a part that reaches the position of the liquid reservoir 5. That is, this position 8 corresponds to the uppermost stream side end of the coating liquid reservoir 5. The reservoir 5 is important for obtaining a smooth coated surface 4 having no uncoated portion by spreading over the entire width direction, but is also important in the longitudinal direction. For example, when the supply unevenness of the coating liquid to the pool 5 temporarily occurs, the amount of the pool 5 changes, but the amount of the pool 5 is larger than the supply amount per minute of the coating liquid. If adjusted, the magnitude of the amount does not substantially affect the coating thickness of the coating surface 4. That is, the reservoir 5 also functions as a buffer mechanism for uneven flow rate of the coating liquid supply unit 2. In addition, in the coating method of this invention, the one where the sheet-like material which is a to-be-coated material is long can be applied efficiently. Further, the sheet can be applied most efficiently if it is an endless sheet having no end in the length direction and is continuously running. Here, the “substantially” traveling of the sheet-like material in the horizontal direction means that the effect of the present invention (formation of a uniform coated surface) is the same as in the case of the horizontal direction even when traveling in a slightly inclined direction. ) Is meant to include such a case.

  Examples of the air nozzle 3 include those in which the air blowing shape is a slit type, and a plurality of circular and elliptical shapes arranged in the width direction. In the case of the slit type, the clearance of the slit is preferably 1 mm or less, and more preferably 0.8 mm or less. The clearance is preferably 0.05 mm or more.

The attachment position of the air nozzle 3 is preferably a position 1 to 20 mm away from the surface of the sheet-like material 1. The lower limit of this range is significant in terms of avoiding the risk of the reservoir 5 coming into contact with the tip of the air nozzle 3, and the upper limit is significant in terms of sufficiently stabilizing the reservoir 5 and obtaining an air blocking effect. There is. The mounting angle of the air nozzle 3 is preferably within a range of −60 ° to 60 °, with the vertical downward direction being 0 ° with respect to the traveling direction of the sheet-like object 1. The amount of air blown out from the air nozzle 3 is preferably 0.1 to ³⁰ m ³ / min per 1 m of coating width. The air temperature may be room temperature, or hot air of 150 ° C. or lower may be used for the purpose of reducing the viscosity of the coating solution.

According to the coating method of the present invention described above, the sheet-like material 1 having a uniform coated surface 4 can be obtained stably. Coating weight per area 1 m ² of the sheet-like material 1 is usually in the range of ^{1g / m 2 ~100g / m 2} . Further, the coated surface 4 can be further heated or irradiated with ultraviolet rays to obtain a sheet 1 with a cured layer.

  The resin-made or metal-made sheet-like object 1 with the coated surface 4 or its hardened layer can be used for various applications as it is or after being appropriately cut into a desired size.

  Further, for example, by bringing another resin layer or a resin molded body into contact with the cured layer side of the metal sheet 1 with a cured layer, the cured layer is peeled and transferred from the metal sheet 1 to be cured. A resin laminate with layers can also be obtained. This method is particularly useful in a method for producing a plate polymer using a continuous plate making apparatus. That is, it travels in a state in which the opposite belt surfaces are sandwiched between the opposite belt surfaces of two endless belts arranged so as to travel at the same speed in the same direction and the belt surfaces on both sides thereof. A polymerizable raw material containing methyl methacrylate is supplied from one end to a space surrounded by a continuous gasket, the polymerizable raw material is solidified as the belt runs in the heating zone, and a plate-like polymer is taken out from the other end. In the method for producing a plate-like polymer, at least one of the opposed belt surfaces of two endless belts (for example, a mirror-polished endless belt made of a stainless steel plate having a thickness of 1.0 mm or more) of the continuous plate making apparatus. The surface is provided with a cured layer of the coated surface formed in advance by the coating method of the present invention, and the cured layer is transferred to the surface of the plate-like polymer together with continuous polymerization of the raw material. By carrying out, a plate-like polymer with a hardened layer can be produced stably and efficiently.

EXAMPLES Hereinafter, although an Example demonstrates this invention in more detail, these do not limit this invention. In the following description, “parts” indicates parts by mass.

<Example 1>
20 parts of trimethylolpropane triacrylate (manufactured by Toagosei Co., Ltd., trade name Aronix M309), urethane acrylate having an average molecular weight of about 1146 (trade name: NK Oligo U-6HA, made by Shin Nakamura Chemical Co., Ltd.), 1, Using a mixture of 50 parts of 6-hexanediol diacrylate (trade name biscoat # 230, manufactured by Osaka Organic Chemical Co., Ltd.) as the coating liquid, a mirror-polished 500 mm wide austenitic stainless steel sheet as sheet 1 Then, continuous coating with a coating width of 460 mm was carried out for 10 hours according to the method shown in FIG.

Here, the coating temperature was 25 ° C., and the viscosity of the coating solution at 25 ° C. was 60 mPa · s. Further, as the coating liquid supply unit 2, four circular spray nozzle pipes adjusted to have an average droplet diameter of 1 mm are arranged 150 mm away from the surface of the sheet-like material 1 so as to form a line at 115 mm intervals in the width direction. did. As the air nozzle 3, a slit type air nozzle having a width of 600 mm in the width direction and having a slit clearance of 0.15 mm and an air flow rate of 1 m ³ / min is used. The air nozzle is attached at a position 10 mm away from the surface of the sheet-like material 1. The air nozzle angle was arranged so as to be inclined 5 ° upstream from the vertically downward direction with respect to the traveling direction of the sheet-like object 1.

The coating speed (running speed of the sheet 1) was 2 m / min. The supply amount of the coating liquid was 23 g / min in total for the four pipes. That is, the coating amount is 25 g / m ² when it is assumed that the supplied coating liquid does not leak to the outside and the product is all coated.

During coating for 10 hours, the meandering width of the coating width is within 10 mm from side to side, and the coating liquid does not leak to the outside from the left and right ends of the stainless steel plate, and the coating liquid is collected with a catch pan or the like. There was no need. Further, during the coating, a reservoir 5 having a length of 50 mm or more is formed stably over the entire coating width from directly under the air nozzle 3 toward the upstream side. In the visual evaluation of the coated surface, an uncoated portion or an extreme There was no thin film part. At the end of the coating, the supply of the coating liquid and the conveyance of the sheet 1 were suddenly stopped at the same time. The reservoir 5 was quickly recovered and the amount of the liquid was measured to find 41 g. Furthermore, for a sample of 500 m ² of the obtained coated surface, the coating thickness is measured using a Keyence laser focus shift meter LT-8100 (measurement unit: LT-8010SO) for a total of 50 points every 10 m ^2. When converted into the coating amount from the density of the coating solution, the fluctuation of the coating amount was within 25 g / m ² plus or minus 15%.

<Example 2>
In this example, continuous coating was performed as follows using a larger apparatus than that of Example 1.

  A mixture of 50 parts of urethane acrylate having an average molecular weight of about 1146 and 50 parts of 1,6-hexanediol diacrylate was used as a coating liquid, and a mirror-polished 2800 mm wide austenitic stainless steel sheet was used as a sheet-like product 1 to form a sheet. A continuous coating with a coating width of 2600 mm was performed for 20 hours according to the method shown in FIG.

Here, the coating temperature was 17 ° C., and the viscosity of the coating solution at 17 ° C. was 1080 mPa · s. In addition, as the coating liquid supply unit 2, eight stainless hollow pipes having an inner diameter of 1 mm and an outer diameter of 3 mm were arranged at a distance of 200 mm from the surface of the sheet-like material 1 so as to form one row at intervals of 325 mm in the width direction. The air nozzle 3 is a slit type air nozzle of 3000 mm in the width direction and has a slit clearance of 0.1 mm and an air flow rate of 6 m ³ / min. The air nozzle is mounted at a position 4 mm away from the surface of the sheet 1. The air nozzle angle is arranged so as to be inclined 15 ° upstream from the vertically upward direction with respect to the traveling direction of the sheet-like object 1.

The coating speed was 4 m / min. The supply amount of the coating liquid was 167 g / min in total for the eight pipes. That is, the coating amount is 16 g / m ² when it is assumed that the supplied coating liquid does not leak to the outside and the product is all coated.

During the coating for 20 hours, the meandering width of the coating is within 20 mm from side to side, and the coating liquid does not leak to the outside from the left and right ends of the stainless steel plate, and the coating liquid is collected with a catch pan or the like. There was no need. Further, during the coating, a reservoir 5 of 15 mm or more is formed stably over the entire coating width from directly under the air nozzle 3 toward the upstream side, and in the visual evaluation of the coated surface, an uncoated portion or an extreme thin film portion. There was nothing. At the end of coating, the amount of liquid in pool 5 was measured in the same manner as in Example 1, and it was 125 g. Further, when the coating thickness was measured in the same manner as in Example 1 and converted into the coating amount, the fluctuation of the coating amount was within 16 g / m ² plus or minus 12%.

<Example 3>
Continuous coating was performed in the same manner as in Example 2 except that the reservoir 5 having a size of 50 mm or more was adjusted so as to be stably formed over the entire coating width from directly below the air nozzle 3 toward the upstream side. During the coating for 20 hours, the meandering of the coating width was within 20 mm from side to side, and there was no need to collect the coating solution with a catch pan or the like. In addition, during the coating, the coated surface was visually evaluated to have no uncoated portion or extreme thin film portion, and an extremely smooth coated surface having a good appearance was stably obtained. At the end of coating, the amount of liquid in the reservoir 5 was measured in the same manner as in Example 1, and it was 407 g. Further, when the coating thickness was measured in the same manner as in Example 1 and converted into the coating amount, the fluctuation of the coating amount was within 16 g / m ² plus or minus 10%.

<Comparative Example 1>
As shown in FIG. 2, the stainless steel plate (sheet-like product 1) is placed along the backup roll 6, and the air nozzle angle is inclined 5 ° upstream from the direction perpendicular to the tangent to the stainless steel plate along the roll 6. A continuous coating for 10 hours was performed in the same manner as in Example 1 except that the coating was performed. During the coating, the catch pan 7 shown in FIG. 2 was removed.

  During the coating for 10 hours, a similar accumulation to that in Example 1 was confirmed on the sheet-like material 1 upstream from the air nozzle 3, but the amount was so small that it was difficult to recover and it was likely to be interrupted in the width direction. Part was recognized. Further, in the visual evaluation of the coated surface, many uncoated portions and extreme thin film portions were observed, and the coated surface was not satisfactory.

It is a schematic diagram which shows an example of the coating method of this invention. It is a schematic diagram which shows an example of the conventional coating method.

Explanation of symbols

1 Sheet (Coating object)
2 Coating liquid supply section 3 Air nozzle 4 Coating surface 5 Coating liquid pool 6 Backup roll 7 Catch pan 8 Position where coating liquid pool contacts with sheet

Claims (7)

Coating surface is mirror-polished, thickness is traveling sheet stainless steel of 1.0mm or more in substantive horizontally at a speed of 0.1m / min~10m / min, the sheet After supplying the coating liquid from above, by blowing air to the sheet-like material from the air nozzle, a uniform coating surface is obtained by generating a pool of coating liquid over the entire coating width upstream of the air nozzle. A coating method that does not require collection of excess coating solution.   The coating method according to claim 1, wherein the amount of the coating liquid accumulated is adjusted to be larger than the supply amount per minute of the coating liquid. The coating method according to claim 1 or 2 , wherein the sheet-like material is an endless belt. The coating method according to any one of claims 1 to 3 , wherein the distance between the air nozzle and the surface of the sheet is in the range of 1 mm to 20 mm. The coating method according to any one of claims 1 to 4 , wherein an air ejection portion shape of the air nozzle is a slit shape extending in a width direction of the sheet-like material. The coating method according to claim 5 , wherein the clearance of the slit portion is 0.8 mm or less. The two belts are arranged in such a way that the opposite belt surfaces run in the same direction at the same speed, and the two belts that are sandwiched between the opposite belt surfaces and the belt surfaces on both sides of the belts A polymerizable material containing methyl methacrylate is supplied from one end of the space surrounded by the gasket to solidify the polymerizable material as the belt runs in the heating zone, and a plate-shaped polymer is taken out from the other end. In the method for producing a polymer,
At least one surface of the two opposite belt surfaces of the two endless belts has a hardened layer of the coating surface formed in advance by the coating method according to any one of claims 1 to 6 , and The method for producing a plate polymer with a hardened layer, wherein the hardened layer moves to the surface of the plate polymer.

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