JP4585911B2 - Air knife, coating method and apparatus, and method for producing plate polymer with cured layer - Google Patents

Description

  The present invention relates to an air knife coating method and apparatus for thinning a coating liquid supplied on a sheet-like material by blowing high-speed air, and an air knife used in this coating method. Moreover, this invention relates to the manufacturing method of the plate-shaped polymer with a hardened layer which provides the hardened layer of a coating liquid on a plate-shaped polymer.

  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 water repellent, waterproofing and deodorant, and various coating methods are proposed according to each purpose. One of these is the air knife coating method. The air knife coating method is a method in which the coating liquid supplied to the object to be coated is thinned with high-speed air to obtain a coating part, but the distance between the lip at the tip of the air knife and the object to be coated is separated by several mm. Therefore, it is advantageous in that the risk of contact between the object to be coated and the lip is low as compared with, for example, a distance of several tens of μm at most in the die coating method. In particular, in the high-tech industry in recent years, the object to be coated and the coating apparatus become more expensive, and the damage caused by contact is very large, so the significance is great. However, in order to control the smoothness of the coated part, there is only an indirect method of adjusting the strength of the air to be blown or expecting spontaneous disappearance of unevenness due to the leveling effect of the coated liquid itself. However, it has not always been a level that can satisfy the appearance requirements of high-level coating parts in recent years.

  The appearance of the coating part is the film thickness unevenness, but as shown in Patent Document 1, the curvature radius of the tip part is set for the suppression of the film thickness unevenness that gradually changes over the entire coating part. There is a method of suppressing the cavitation of the tip by setting the thickness to 1 mm or less and improving the film thickness control of the substrate surface. However, the greatest influence on the appearance of the coated area is not the film thickness unevenness over the entire coated area, but a sudden film thickness change within a limited range (hereinafter referred to as local unevenness). However, even if the amount of change is subtle, it appeals greatly to human eyes. For example, a streak-like appearance defect along the traveling direction of the object to be coated can be sufficiently confirmed when there is a film thickness change of about 5 μm within 10 mm in the width direction.

As described above, in air knife coating, it has been required to satisfy the higher level appearance requirements of the coating part.
Japanese Utility Model Publication No. 50-48818

  An object of the present invention is to provide an air knife that enables air knife coating in which the coated portion has no local unevenness and the appearance of the coated portion is excellent.

  Another object of the present invention is to provide a coating method and apparatus capable of obtaining a coated part having excellent appearance without local unevenness.

  Still another object of the present invention is to provide a plate-like polymer with a hardened layer capable of obtaining a hardened layer having no appearance of local unevenness in producing a plate-like polymer having a hardened layer of a coating liquid. It is to provide a manufacturing method.

  As a result of intensive studies to achieve the above object, the present inventors have found that the local unevenness that greatly affects the appearance of the coated part is affected by the structure near the lip part of the air knife, particularly immediately before the air is injected and the injection. By changing the structure of the part related to the moment, the appearance of the coating part was dramatically improved and the present invention was completed.

According to the present invention, there is provided a slit-shaped coating air knife having an inner wall of the slit portion parallel to the air ejection direction, and a lip surface that is a plane that is continuous and perpendicular to the inner wall,
The surface roughness of the inner wall and the lip surface is 0.3 μm or less as the surface roughness Ra specified by JISB0601, and the corner formed by the inner wall and the lip surface has a curvature, and the curvature R is An air knife for coating that is 0.005 mm or more and 1 mm or less is provided.

  It is preferable that the clearance of the slit portion is 0.8 mm or less and the height of the slit inner wall is 1 mm or more and 50 mm or less.

  In the air knife, it is preferable that a plurality of supply ports for supplying compressed air are arranged on the side surface at a pitch of 50 mm or more and 400 mm or less.

  According to the present invention, there is provided a coating method in which a sheet-like material is caused to travel substantially in the horizontal direction, and a coating liquid is supplied onto the sheet-like material, and then air is blown onto the sheet-like material from the coating air knife. The

  It is preferable that the traveling speed of the sheet is 0.1 m / min or more and 10 m / min or less.

According to the present invention, the opposite belt surfaces of two endless belts arranged so that the opposite belt surfaces run in the same direction at the same speed, and in the state sandwiched between the belt surfaces on both sides thereof. A polymerizable raw material is supplied from one end of the space to a space surrounded by a running continuous gasket, and the polymerizable raw material is solidified as the belt travels in the space, and a plate-like polymer is formed from the other end of the space. In the method for producing a plate-like polymer,
A hardened layer of the coating part formed in advance by the coating method is provided on at least one of the two opposite belt surfaces of the endless belts,
And the manufacturing method of the plate-shaped polymer with a hardened layer characterized by moving this hardened layer to the surface of a plate-shaped polymer is provided.

According to the present invention, traveling means for traveling the sheet material substantially horizontally;
A coating liquid supply means for supplying a coating liquid to the upper surface of the sheet-like material; and an air knife that is arranged downstream of the coating liquid supply means and blows air onto the sheet-like material,
A coating apparatus is provided in which the air knife is the air knife.

  If the air knife of this invention is used, the air knife coating which does not have local unevenness in a coating part, and the external appearance of a coating part is excellent can be performed easily.

  According to the coating method or the coating apparatus of the present invention, it is possible to easily obtain a coating part having an excellent appearance without local unevenness.

  According to the method for producing a plate-like polymer with a cured layer of the present invention, in producing a plate-like polymer having a cured layer of a coating liquid, it is possible to easily obtain a cured layer having no local unevenness and excellent in appearance. Can do.

  As the material of the air knife of the present invention, it can be appropriately selected from known substances as the material of the air knife. For example, resin, metal, etc. can be used. Examples of the metal include austenitic stainless steel, martensitic stainless steel, steel, aluminum, and copper. Examples of the resin include polycarbonate resin, polyamide resin, polyacetal resin, and reinforced polyethylene terephthalate resin.

  The structure of the air knife includes, for example, a main body and a nozzle portion, and the nozzle portion is fixed to the main body by bolts, welding, or the like, and a gasket is sandwiched between two plate-like members. For example, the two plate-like members may be fixed and a slit may be formed on one end face.

  FIG. 1 is a schematic cross-sectional view of a coating air knife of the present invention. In this figure, the surface roughness of the slit inner walls 1, 1 ′ and the lip surfaces 2, 2 ′ is 0.3 μm or less in terms of the surface roughness Ra specified by JIS B0601 from the viewpoint of suppressing local unevenness, preferably 0.1 μm or less, more preferably 0.07 μm or less. The surface roughness is preferably 0.005 μm or more from the viewpoint of ease of polishing. Further, from the viewpoint of the relationship between the air ejection direction and the polishing surface unevenness due to polishing, it is more preferable that the polishing direction is perpendicular to the air passing direction in the polishing performed for that purpose.

  Further, as shown in FIG. 2, the corner 3 formed by the slit inner wall 1 and the lip surface 2 that are perpendicular to each other has a curvature R. From the viewpoint of facilitating ensuring the accuracy of the curvature R over the entire width direction (direction perpendicular to the paper surface in FIG. 1), the curvature R is 0.005 mm or more, preferably 0.01 mm or more, more preferably 0. 0.02 mm or more, and the curvature R is 1 mm or less, preferably 0.8 mm or less, more preferably 0.5 mm from the viewpoint of suppressing the amount of air for obtaining a desired film thickness by improving the anti-damping effect of the air knife coating liquid. The following. The same applies to the corners formed by the inner wall 1 ′ and the lip surface 2 ′ that are perpendicular to each other.

  The clearance 5 between the slit inner walls 1 and 1 ′ is preferably 0.8 mm or less, more preferably 0.5 mm or less, from the viewpoint of excellently preventing an excessive air volume of the supplied air, and the slit full width (FIG. 1). In view of the accuracy of the clearance in the direction perpendicular to the paper surface in FIG.

  As the adjustment of the clearance 5, for example, a plurality of push-pull screws are alternately provided at a predetermined interval in the width direction near the nozzle tip, and the above-mentioned clearance is adjusted by adjusting the screwing amount of these adjustment screws. The method of setting to is mentioned.

  Further, the height of the slit inner wall 1 (length in the vertical direction in the drawing in FIG. 1) is preferably from the viewpoint of improving the effect of rectifying the compressed air by the slit and making the air layer ejected from the nozzle tip difficult to diffuse. 1 mm or more, more preferably 3 mm or more, and preferably 50 mm or less, more preferably 30 mm or less from the viewpoint of suppressing pressure loss in the slit portion.

  Furthermore, as shown in FIG. 3, it is preferable to provide a plurality of compressed air supply ports 4 on one side of the side surface of the air knife 7 and to set the pitch between adjacent supply ports 4 to 50 mm or more and 400 mm or less. The above pitch is preferably 50 mm or more, more preferably 80 mm or more, and even more preferably 100 mm or more from the viewpoint of preventing the supply port from increasing and the handling of piping and the like to the nozzle from becoming complicated, and the amount of air jetted from the air knife Is preferably 400 mm or less, more preferably 380 mm or less, and even more preferably 350 mm or less from the viewpoint of suppressing the difference between the portion near the supply port and the portion far from the supply port.

  The compressed air supply port is preferably provided on one side of the side surface of the slit of the air knife (the direction perpendicular to the paper surface in FIG. 1). This is because it can be easily suppressed by increasing the number of supply ports that the amount of air jetted from the air knife differs between a portion close to the supply port and a portion far from the supply port.

  The diameter of the supply port 4 is preferably 5 mm or more in consideration of pressure loss.

  As an internal structure of the nozzle (air knife), for example, a structure in which the plurality of supply ports are connected to one space 9 sufficiently wider than the clearance 5 at the tip of the nozzle, so that a portion between the portion close to the supply port and a portion far from the supply port is provided. It is also possible to balance the amount of air ejected from the air knife.

  As described above, by disposing the supply port 4 and providing the space 9, the size of the nozzle in the coating width direction can be expanded without restriction while suppressing unevenness in the air ejection amount.

  With reference to FIG. 3, an example in which coating is performed on the sheet-like material traveling substantially in the horizontal direction by the air knife of the present invention will be described.

  The sheet-like object 6 (object to be coated) travels substantially in the horizontal direction, and the coating liquid is supplied to the upper surface of the sheet-like object 6 from the coating liquid supply means 8 positioned above the sheet-like object 6.

  The coating liquid supply means may be a simple structure in which a single hollow pipe or a plurality of hollow pipes are arranged in the width direction, and a spray nozzle for spraying the coating liquid to draw a certain area, such as a circular spray nozzle. One or a plurality of lines 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 knife 7 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 means 8 is at least 10 mm away from the surface of the sheet-like material 6 from the viewpoint that the supplied coating liquid can obtain a drop speed that is not affected by the airflow from the air knife 7. It is preferable. In the present specification, the term “width direction” simply refers to the horizontal direction perpendicular to the traveling direction of the sheet-like material 6 (the object to be coated), and the term “longitudinal direction” refers to the sheet-like material 6. It refers to the direction of travel. Further, upstream and downstream are meanings when the traveling of the sheet 6 is viewed as a flow.

  There is no restriction | limiting in particular in the material of the sheet-like material 6 which is a coating object, For example, resin, a metal, etc. can be used. Examples of the metal include austenitic stainless steel, martensitic stainless steel, steel, aluminum, and copper. Moreover, what grind-processed the surface of these coating sides can also be used. 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-like material is desirably 0.1 mm or more from the viewpoint that a tension can be easily applied to the sheet-like material and the vehicle can travel. 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.

  The coating liquid supplied onto the sheet-like material 6 traveling substantially in the horizontal direction is supplied to a coating liquid reservoir formed over the entire coating width by the damming effect of the air knife 7. On the other hand, from the position immediately below the air knife 7 toward the downstream, a certain amount of coating liquid constantly moves from the pool together with the sheet-like material as a coating portion. Here, the “substantially” traveling of the sheet-like material in the horizontal direction means that the coated portion has a desired uniformity as in the case of the horizontal direction even when traveling in a slightly inclined direction. If it can be formed, it is meant to include such a case.

  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 (viscosity at the time of actual coating) can be easily transferred from the pool together with the sheet-like material by using a constant amount of the coating liquid as a coating part due to the damming effect of the air knife 7. From the viewpoint of being able to be made, it is preferably 1 mPa · s or more and preferably 5000 mPa · s or less.

  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, an esterified product obtained from 1 mol of a polyhydric alcohol and 2 mol or more of (meth) acrylic acid or a derivative thereof, a polyhydric alcohol and a polyvalent carboxylic acid or anhydride thereof, and (meth) acrylic acid or a product thereof. Examples thereof include a linear esterified product having two or more (meth) acryloyloxy groups in one molecule obtained from the derivative.

  Examples of esterified products obtained from 1 mol of polyhydric alcohol and 2 mol or more of (meth) acrylic acid or derivatives thereof include diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, and tetraethylene glycol. Di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 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, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) Examples include acrylate, tripentaerythritol tetra (meth) acrylate, tripentaerythritol penta (meth) acrylate, tripentaerythritol hexa (meth) acrylate, tripentaerythritol hepta (meth) acrylate, and the like.

In a linear esterified product having two or more (meth) acryloyloxy groups in one molecule obtained from a polyhydric alcohol, a polyvalent carboxylic acid or an anhydride thereof, and (meth) acrylic acid or a derivative thereof, As a preferred combination of a monohydric alcohol and a polyvalent carboxylic acid or anhydride thereof and (meth) acrylic acid,
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 Acid / trimethylolethane / (meth) acrylic acid, succinic acid / trimethylolpropane / (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, guru Luric acid / trimethylolpropane / (meth) acrylic acid, glutaric acid / glycerin / (meth) acrylic acid, glutaric acid / pentaerythritol / (meth) acrylic acid, sebacic acid / trimethylolethane / (meth) acrylic acid, sebacine 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, or a condensate by a combination of maleic anhydride / pentaerythritol / (meth) acrylic acid.

Other examples include
Isocyanates such as trimethylolpropane toluylene diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, xylene diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate), isophorone diisocyanate, trimethylhexamethylene diisocyanate, and 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-acryloyloxy-2-hydroxypropyl (meth) acrylate, etc. (Meth) acrylates of urethane (meth) acrylate obtained by reacting 3 moles or more of (meth) acrylates per molecule of isocyanate; and di (meth) acrylate of tris (2-hydroxyethyl) isocyanuric acid And poly [(meth) acryloyloxyethyl] isocyanurate such as 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, or cyclohexane can be appropriately added to the coating solution for the purpose of adjusting the viscosity.

Moreover, a polymerization initiator can also be added to a coating liquid. 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; and 2,2 ′ -Azobis (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis (1-cyclohexanecarbonitrile), 2,2'-azobis (2,4,4 -Trimethylpentane) and other azo compounds Can be mentioned.

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, 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; and 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 appropriately added to the coating solution.

  If the coating air knife of the present invention described above is used, a coated part having a good appearance can be stably obtained.

  For example, by running the sheet material in a substantially horizontal direction and supplying the coating liquid onto the sheet material, the coating method for blowing air from the coating air knife onto the sheet material causes local unevenness. Generation | occurrence | production of this can be suppressed and the sheet-like thing which has a coating part with a favorable external appearance can be obtained stably.

  In particular, the coating air knife can be used particularly suitably when coating is performed under conditions where the traveling speed of the sheet-like material is 0.1 m / min or more and 10 m / min or less. This is because a fixed amount of coating liquid can be steadily transferred from the pool together with the sheet-like material as a coating portion by the damming effect of the air knife 7. By setting the traveling speed of the sheet-like material to 10 m / min or less, it is possible to excellently prevent the influence of the conveyance of the coating liquid by the sheet-like material from being greater than the effect of preventing the air knife 7 from being applied. It is easy to obtain a part.

  Alternatively, a material that can be cured with heat or ultraviolet light is used for the coating liquid, and the coated part is further heated or irradiated with ultraviolet light to obtain a sheet-like material with a hardened layer.

  The coated part or a sheet-like material with a cured layer thereof can be used for various purposes as it is or after being appropriately cut into a desired size.

  Also, for example, another resin layer or resin molded body is attached to the cured layer side of the metal sheet with a cured layer in the coating part, and cured from the metal sheet to the resin layer or resin molded body. A resin laminate with a cured layer can also be obtained by separating and transferring the layers. This method is particularly useful in a method for producing a plate polymer using a continuous plate making apparatus. For example, as shown in FIG. 4, two opposite endless belts 10, 10 ′ arranged so that the opposite belt surfaces run in the same direction at the same speed, and both side portions thereof A polymerizable raw material (for example, a polymerizable raw material containing methyl methacrylate) is supplied from one end of the space to a space surrounded by a continuous gasket 11 that runs while being sandwiched between belt surfaces, In the method for producing a plate-like polymer, for example, in the heating zone provided in this space, the polymerizable raw material is solidified as the belt runs and the plate-like polymer is taken out from the other end of the space. 10, 10 ′ (for example, a mirror-polished endless belt made of a stainless steel plate having a thickness of 1.0 mm or more) is coated in advance on at least one of the opposing belt surfaces. By providing a cured layer of the coating part formed by the method and transferring the cured layer to the surface of the plate-like polymer, the plate-like polymer with a cured layer having a good appearance can be stabilized. And it can manufacture efficiently. That is, the coating part of the coating liquid that can be cured by the coating method of the present invention is formed on the belt surface of the endless belt, and then the coated part is cured to form a cured layer on the endless belt. In this way, a polymerizable raw material is supplied to a space surrounded by a pair of opposed endless belts each having a hardened layer formed on at least one side, and a gasket 11 for sealing a side portion, in contact with the hardened layer. A plate having a cured layer on at least one surface by continuously polymerizing the polymerizable material and transferring the cured layer from the endless belts 10, 10 'to a plate-like polymer obtained by polymerizing the polymerizable material. A polymer can be obtained. As the traveling means for traveling the sheet-like material, a known mechanism capable of running the sheet-like material substantially horizontally can be used as appropriate.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in more detail, these do not limit this invention.

<Example 1>
The coating apparatus as shown in FIG. 3 is disposed at two locations (16a and 16b) of the continuous plate making apparatus shown in FIG. Here, continuous coating was performed using only the lower coating apparatus installed at the coating apparatus installation location 16b, and a coating part was formed on the sheet-like material.

  The apparatus of FIG. 4 has a total length of 120 m, the two stainless steel endless belts 10 and 10 ′ have a thickness of 2 mm and a width of 1500 mm, and the endless belt 10 ′ is indicated by a sheet (indicated by 6 in FIG. 3). Used). The endless belts 10 and 10 ′ are given a tension of 30 MPa in both upper and lower directions by hydraulic pressure. A gasket made of polyvinyl chloride is installed as the gasket 11.

  For the coating solution, 20 parts by mass of trimethylolpropane triacrylate (manufactured by Toagosei Co., Ltd., trade name: Aronix M309), urethane acrylate (made by Shin-Nakamura Chemical Co., Ltd., trade name: NK) with a weight average molecular weight of about 1146 A mixture of 30 parts by mass of Oligo U-6HA) and 50 parts by mass of 1,6-hexanediol diacrylate (manufactured by Osaka Organic Chemical Co., Ltd., trade name: Biscote # 230) was used.

  As the coating liquid supply means 8, four circular spray nozzle pipes adjusted to have an average droplet diameter of 1 mm are spaced 150 mm vertically upward from the surface of the sheet-like material 6 so as to form one row at 350 mm intervals in the width direction. Arranged.

In the air knife 7, the surface roughness Ra of the slit inner walls 1 and 1 ′ and the lip surfaces 2 and 2 ′ is 0.07 μm as the surface roughness Ra defined by JIS B0601, and the slit inner wall 1 and the lip surface 2 And the curvature of the corner 3 formed by the inner wall 1 ′ and the lip surface 2 ′ were both 0.05 mm ± 0.02 mm. The surface roughness Ra is measured by measuring the roughness of the polished surface with a surface roughness meter, and the curvature is measured by slicing and enlarging the shape after shaping the curved portion using a urethane-based resin. The curvature part was measured. The clearance 5 between the slits (between the inner walls 1 and 1 ′) was 0.1 mm, and the heights of the slit inner walls 1 and 1 ′ were both 20 mm. Further, two supply ports 4 are arranged on one side of the side surface extending in the slit width direction, and the pitch is set to 800 mm. The air volume of the air knife is 1.5 m ³ / min, the mounting position of the air knife is 10 mm away from the surface of the sheet-like object 6, and the air knife angle (air ejection direction) is vertically downward with respect to the traveling direction of the sheet-like object 6 It was arranged so as to be inclined 5 ° upstream.

  The coating speed (traveling speed of the sheet-like material 6) is 3 m / min, and the inside of the sheet-like material 6 is 50 mm from both side edges (that is, in the region from both side edges of the sheet-like material to 50 mm respectively). The coating width was 1400 mm. The supply amount of the coating liquid was 1.5 ml / s. The coating temperature was 25 ° C., and the viscosity of the coating solution at 25 ° C. was 60 mPa · s. .

  After curing the coated part using a high-pressure mercury lamp (120 W / cm), the obtained coated part was evaluated by the following two methods. First, as the appearance of the coating part, the reflected light of the coating part obtained during continuous coating was visually observed in an environment with an illuminance of 600 lx. Regarding the measurement of film thickness accuracy, a laser focus displacement meter LT-8010 (trade name) manufactured by Keyence Corporation is attached to the upper part of the coating part and traversed in the width direction at 5 mm / sec. The film thickness was measured continuously. The evaluation results are shown in Table 1. In addition, evaluation of the said coating part can be implemented similarly even before hardening.

  After measurement of the thickness of the cured layer of the coating part formed by the coating method as described above, a plate-like polymer with a cured layer was produced using the continuous plate making apparatus of FIG. 4 under the following conditions. .

  To 100 parts by mass of methyl syrup methacrylate (viscosity 1 Pa · s, 20 ° C.) having a polymerization rate of 20% by mass, tert-hexyl peroxypivalate (manufactured by NOF Corporation, trade name: perhexyl PV) 0 as a polymerization initiator .18 parts by mass and 0.005 parts by mass of sodium dioctyl sulfosuccinate as a release agent were added and mixed uniformly to obtain a liquid polymerizable raw material. The polymerizable raw material was degassed in a vacuum vessel, and the polymerizable raw material was continuously supplied onto an endless belt on which the apparatus of FIG. 4 runs.

  In the first half of the continuous plate making apparatus, heating was performed with 86 ° C. hot water sprays 13 and 13 ′ (heating zone 60 m). Note that a total of 150 pairs of upper and lower roll pairs 14 and 14 'are arranged at equal intervals in the heating zone by the hot water sprays 13 and 13'. After the heating by the hot water sprays 13 and 13 ', heat treatment was performed by the far infrared heaters 15 and 15' (heat treatment zone 25m). By solidifying under such conditions to form a plate-like polymer, and peeling the cured layer from the endless belt together with the plate-like polymer, a plate-like polymer having a thickness of 3 mm and a width of 1400 mm having a cured layer on one side was produced. The initial heating zone 12 was maintained at a temperature of 80 ° C. and a relative humidity of 70%.

<Example 2>
Table 1 shows the results of continuous coating and plate making performed in the same manner as in Example 1 except that the pitch of the supply ports 4 was set to 250 mm.

<Comparative Example 1>
The surface roughness of the slit inner walls 1 and 1 ′ and the lip surfaces 2 and 2 ′ is 1.8 μm as the surface roughness Ra specified by JIS B0601, and the pitch of the supply ports 4 is 250 mm. Table 1 shows the results of continuous coating and plate making and evaluation.

<Comparative Example 2>
The curvature of the corner 3 formed by the slit inner wall 1 and the lip surface 2 and the curvature of the corner formed by the inner wall 1 ′ and the lip surface 2 ′ are both 0.003 mm, and the curvature R is partially 0 mm. Table 1 shows the results obtained by performing continuous coating and plate production in the same manner as in Example 1 except that the pitch of the supply ports 4 was 250 mm.

  As is apparent from the results shown in Table 1, the coated part of Example 1 had a good appearance and the film thickness accuracy was sufficiently good. In Example 2, the appearance of the coated part was the same level as in Example 1, but the film thickness accuracy was even better. On the other hand, in Comparative Example 1, 14 streaks along the running direction were observed non-uniformly in the running direction of the sheet-like material, and the streaks did not disappear during continuous coating. When the thickness of the stripe was measured in detail over a width of 20 mm, it was found that a concave portion having a thickness of 14 μm and a convex portion having a thickness of 22 μm were adjacent to each other. The coated part containing such streaks was insufficient as the appearance of the product. In Comparative Example 2, many streaks similar to those in Comparative Example 1 were observed in the running direction of the sheet-like material, and the streaks did not disappear during continuous coating. When the film thickness was measured in detail in the vicinity of the stripe over a width of 20 mm, it was found that a concave portion having a thickness of 17 μm and a convex portion having a thickness of 25 μm were adjacent to each other. The coated part containing such streaks was insufficient as the appearance of the product.

  The coating method and apparatus and the coating air knife of the present invention can be widely used in the field of information recording, electrical / electronic fields and the like.

  The manufacturing method of the plate-shaped polymer with a hardened layer of this invention can be utilized suitably in manufacture of the front plate of a display system member, etc.

It is typical sectional drawing which shows an example of the air knife for coating of this invention. It is typical sectional drawing to which a part of air knife shown in FIG. 1 was expanded. It is a schematic diagram which shows an example of the coating apparatus using the air knife for coating of this invention. It is a schematic diagram which shows the example of a continuous plate making apparatus.

Explanation of symbols

1, 1 'slit inner wall 2, 2' lip surface 3 angle formed by slit inner wall and lip surface 4 compressed air supply port 5 slit portion (slit clearance)
6 Sheet-like material 7 Air knife for coating (Coating object)
8 Coating liquid supply means 9 Space 10 communicating with a plurality of compressed air supply ports 10, stainless steel endless belt 11 gasket 12 initial heating zone 13, 13 ′ hot water spray 14, 14 ′ upper and lower roll pairs 15, 15 ′ far infrared Heater 16a, coating device installation location (upper side)
16b, coating device installation location (lower side)

Claims (7)

A slit-shaped coating air knife having an inner wall of a slit portion parallel to the air ejection direction, and a lip surface that is a plane that is continuous and perpendicular to the inner wall,
The surface roughness of the inner wall and the lip surface is 0.3 μm or less as the surface roughness Ra specified by JISB0601, and the corner formed by the inner wall and the lip surface has a curvature, and the curvature R is An air knife for coating that is 0.005 mm or more and 1 mm or less.   The coating air knife according to claim 1, wherein the clearance of the slit portion is 0.8 mm or less and the height of the inner wall of the slit is 1 mm or more and 50 mm or less.   The coating air knife according to claim 1 or 2, wherein a plurality of supply ports for supplying compressed air are arranged on a side surface at a pitch of 50 mm or more and 400 mm or less.   The sheet-like material is allowed to travel substantially in the horizontal direction, and after supplying the coating liquid onto the sheet-like material, air is supplied from the coating air knife according to any one of claims 1 to 3 onto the sheet-like material. Spraying coating method.   The method according to claim 4, wherein a traveling speed of the sheet-like material is 0.1 m / min or more and 10 m / min or less. Two endless belts arranged so that the opposite belt faces run in the same direction at the same speed, and the opposite belt faces, and running continuously in a state sandwiched between the belt faces on both sides. A plate-like material in which a polymerizable raw material is supplied from one end of the space to a space surrounded by the gasket, and the polymerizable raw material is solidified as the belt runs in the space, and a plate-like polymer is taken out from the other end of the space. In the method for producing a polymer,
A hardened layer of the coating portion formed by the coating method according to claim 4 or 5 in advance is provided on at least one of the opposing belt surfaces of the two endless belts,
And the manufacturing method of the plate-shaped polymer with a hardened layer characterized by moving this hardened layer to the surface of a plate-shaped polymer. Traveling means for traveling the sheet material substantially horizontally;
A coating liquid supply means for supplying a coating liquid to the upper surface of the sheet-like material; and an air knife that is arranged downstream of the coating liquid supply means and blows air onto the sheet-like material,
The coating apparatus whose air knife is the air knife as described in any one of Claims 1-3.

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