JP2016043321A - Manufacturing method for film with coating film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for a film with a coating film capable of suppressing poor appearance and breaking of a film roll by suppressing an increase in film thickness in an end area of the coating film.SOLUTION: A manufacturing method for a film with a coating film includes a coating film formation process for forming a coating bead between a tip of a die coater 400 and the side of a first surface W1 of a support body W and forming a coating film 24 on the side of the first surface W1. A decompression chamber 440 is provided to include two side plates 442 arranged oppositely in a width direction of the support body W at a position on an upstream side of the die coater 400. A distance L1 between the side plates 442 and a backup roller 420 is in the range of 100-1500 μm. A distance L2 between the side plates 442 and an end in the width direction of the coating film 24 is in the range of 5-200 mm. A decompression degree in the decomposition chamber 440 is in the range of 500-900 Pa. A discharge angle of coating liquid discharged from a slit is -90 to 0°.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method for producing a film with a coating film.

  A coating method using a die coater is known as a method of coating continuously while conveying a support. In this coating method, a coating solution is discharged from a slit of a die coater, a coating bead is formed between the support and the tip of the die coater, and a coating film is formed on the support.

  The coating method using a die coater has a problem that the film thickness of the coating film is thicker in the end region in the width direction of the coating film than in the central region of the coating film.

  In order to cope with this problem, for example, Patent Document 1 discloses that spacers are provided at both ends of the slit of the die coater so that the discharge width spreads outward toward the tip.

  Patent Document 2 discloses adjusting the degree of decompression of a decompression chamber that is arranged at a position upstream of the die coater and divided into a plurality of parts in the width direction.

JP 2000-260310 A JP 2008-155164 A

  However, when a coating liquid having a relatively high viscosity, for example, a coating liquid having a viscosity of 7 mPa · s or more is discharged from a slit of a die coater to form a coating film on a support, it is described in Patent Document 1. In the method of controlling the film thickness with the spacer, there is a problem that the film thickness at the end is not sufficiently suppressed, and the entire film thickness is insufficient at the end. In Patent Document 2, since the film thickness is suppressed only by the degree of decompression, there is a problem that the film thickness in the end region is not sufficiently suppressed in the coating liquid having a viscosity of 7 mPa · s or more. Therefore, when a film with a coating film produced by the method described in Patent Document 1 and Patent Document 2 is wound up to form a film roll, the appearance failure of the film roll occurs or the film roll breaks. There is a problem to do.

  This invention is made | formed in view of such a situation, and it suppresses that the external appearance defect of a film roll and the fracture | rupture of a film roll are suppressed by suppressing that the film thickness in the edge part area | region of a coating film becomes thick. It aims at providing the manufacturing method of the film with a coating film which can be performed.

  The method for producing a film with a coating film according to the present invention includes a feeding step of continuously feeding a long support having a first surface and a second surface, and winding the second surface side of the support around a backup roller. The tip of the die coater and the first surface of the support are discharged by discharging a coating liquid having a viscosity of 7 mPa · s or more to the first surface side of the support through the slit of the die coater while transporting the support. A coating bead forming step of forming a coating bead between the first side of the support and a coating film forming step of forming a coating film on the side of the first surface of the support, and a position upstream of the die coater And a decompression chamber including two side plates opposed to each other in the width direction of the support, the distance L1 between the side plate and the backup roller is in the range of 100 μm to 1500 μm, and the width of the side plate and the coating film The distance L2 to the end in the direction is in the range of 5 mm to 200 mm, the degree of vacuum in the vacuum chamber is in the range of 500 Pa to 900 Pa, and the discharge angle θ of the coating liquid discharged from the slit is −90 ° to 0 °.

  According to the present invention, the distance L1 between the side plate and the backup roller, the distance L2 between the side plate and the end in the width direction of the coating film, the degree of decompression in the decompression chamber, and the coating liquid discharged from the slit By adjusting the discharge angle θ, a coating liquid having a viscosity of 7 mPa · s or more is discharged from the die coater onto the support to form a coating film, and the film thickness in the end region of the coating film and the coating film A difference with the film thickness of the steady region can be suppressed.

  The viscosity of the coating solution is preferably in the range of 10 mPa · s to 100 mPa · s.

  The distance L1 is preferably in the range of 300 μm to 1500 μm.

  More preferably, the distance L1 is in the range of 1000 μm to 1500 μm.

  The distance L2 is preferably in the range of 5 mm to 100 mm.

  It is preferable to have the drying process of drying a coating film, and the active ray irradiation process of irradiating an active ray to the dried coating film after a coating-film formation process.

  According to the method for producing a film with a coating film of the present invention, when a coating liquid having a viscosity of 7 mPa · s or more is applied to a support and a coating film is formed, the film thickness in the end region of the coating film is large. Since it can suppress becoming, the external appearance defect of a film roll and the fracture | rupture of a film roll can be suppressed.

It is a schematic block diagram which shows the manufacturing line of a film with a coating film. It is the perspective view which expanded the die coater partially. It is the top view which looked at the die-coater from the top. It is a graph which shows the relationship between distance L1 and a wind speed in a decompression chamber. It is the schematic which shows the measurement position of a wind speed. It is the side view which looked at the die-coater from the side.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. The present invention is illustrated by the following preferred embodiments. Changes can be made by many techniques without departing from the scope of the present invention, and other embodiments than the present embodiment can be utilized. Accordingly, all modifications within the scope of the present invention are included in the claims.

  Here, in the drawing, portions indicated by the same symbols are similar elements having similar functions. In addition, in the present specification, when a numerical range is expressed using “˜”, upper and lower numerical values indicated by “˜” are also included in the numerical range.

<Production line>
Drawing 1 is a lineblock diagram explaining the whole composition of an example of production line 1 for enforcing the manufacturing method of the film with a coat concerning this embodiment. As shown in FIG. 1, the production line 1 has a delivery process 2, and a delivery machine 200 is installed in the delivery process 2. A film roll WR obtained by winding a long support W into a roll is loaded into the feeder 200. The support body W having the first surface W1 and the second surface W2 unwound from the film roll WR is continuously fed out by the feeder 200. The sent support W is sent to the downstream process while being guided by the guide roller GR.

  From the delivery device 200, the support W can be delivered at a speed of 1 m / min to 50 m / min, for example. Moreover, when sending out, the tension | tensile_strength of 20 N / m-150 N / m can be applied to the support body W, for example. However, it is not limited to this speed and this tension.

  The production line 1 has a dust removal process 3 for removing dust from the support W downstream of the delivery process 2, and a dust remover 300 is installed in the dust removal process 3. The dust remover 300 removes dust adhering to the surface of the first surface W1 of the support W sent from the upstream.

  In this specification, “upstream” and “downstream” are used in the movement (conveyance) direction of the support W. A case of being located on the movement (conveyance) direction side with respect to a certain reference is defined as “downstream”, and a case of being located on the opposite side to the movement conveyance direction is defined as “upstream”.

  The production line 1 has a coating film forming process 4 for forming the coating film 24 on the support W downstream of the dust removal process 3. The coating film forming process 4 includes a die coater 400 having a slit 402, a backup roller 420 disposed opposite to the tip of the die coater 400 that discharges the coating liquid 20, and a decompression chamber 440 disposed at an upstream position of the die coater 400. , Is provided. The decompression chamber 440 includes two side plates 442 arranged to face each other in the width direction of the support W. A blower 444 is connected to the decompression chamber 440 via a pipe 446 in order to decompress the interior of the decompression chamber 440 from the atmospheric pressure.

  In the coating film forming step 4, the support W is continuously conveyed by winding the second surface W <b> 2 side of the support W sent from the upstream around the backup roller 420. Then, the coating liquid 20 having a viscosity of 7 mPa · s or more is discharged from the tip of the die coater 400 to the first surface W1 of the support W through the slit 402 of the die coater 400 while conveying the support W. . A coating bead 22 is formed between the tip of the die coater 400 and the first surface W1 of the support W, and a coating film 24 is formed on the first surface W1 of the support W via the coating bead 22. The coating film 24 is a coating solution applied to the first surface W1 of the support W, and includes a coating solution immediately after coating, a dried coating solution, and a coating solution irradiated with activity. The distance (also referred to as clearance) from the tip of the die coater 400 to the first surface W1 of the support W is determined in consideration of the film thickness of the coating film 24 formed on the support W. The clearance is, for example, 40 μm to 600 μm, preferably 70 μm to 200 μm.

  The coating bead 22 is a coating liquid pool formed between the tip of the die coater 400 and the first surface W1 of the support W. In order to stabilize the formation of the coating bead 22, the inside of the decompression chamber 440 is depressurized to stabilize the shape of the meniscus (gas-liquid interface) on the upstream side of the coating bead 22.

  In the present embodiment, in the coating film forming step 4, the distance L1 between the side plate 442 and the backup roller 420, the distance L2 between the side plate 442 and the edge of the coating film 24, the degree of decompression in the decompression chamber 440, and By adjusting the discharge angle θ of the coating liquid 20 discharged from the slit 402, the difference between the film thickness of the end region of the coating film 24 and the film thickness of the steady region of the coating film 24 is suppressed. . Details of the coating film forming step 4 will be described later.

  The production line 1 has a drying process 5 for drying the coating film 24 downstream of the coating film forming process 4. In the drying process 5, a drying device 500 is installed. The drying method applied to the drying apparatus 500 is not particularly limited, and various drying methods such as a convection drying method using hot air and a radiant drying method using radiant heat such as infrared rays can be employed. In the drying step 5, the drying device 500 evaporates the solvent of the coating film 24 formed on the first surface W1 of the support W, and dries the coating film 24.

  The production line 1 has an actinic radiation irradiation process 6 for irradiating the dried coating film 24 with actinic radiation downstream of the drying process 5. In the active ray irradiation process 6, an active ray irradiation device 600 is installed. An active ray means electromagnetic waves, such as an ultraviolet-ray, an electron beam, and a radiation ((alpha) ray, (beta) ray, gamma ray, etc.). As an actinic ray, ultraviolet rays are practically preferable because they are simple. As the ultraviolet ray source, an ultraviolet fluorescent lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a xenon lamp, a carbon arc lamp, or the like can be used.

  In the active ray irradiation step 6, the active ray irradiation device 600 irradiates the dried coating film 24 with active rays. When actinic radiation is irradiated to the actinic radiation curable resin contained in the dried coating film 24, the actinic radiation curable resin is cured through a crosslinking reaction or the like, and the coating film 24 is cured.

  The production line 1 has a winding step 7 for winding the support W around the film roll WR downstream of the active ray irradiation step 6. In the winding process 7, a winder 700 is installed. The support W having the cured coating film 24 is wound up in the form of a film roll WR by the winder 700.

  The support W and the coating liquid 20 used in the present embodiment will be described.

<Support>
The support W has a first surface W1 and a second surface W2 facing each other, and has a long shape. “Long” means a shape whose length direction is longer than the length in the width direction. The distance between the first surface W1 and the second surface W2 of the support W, that is, the thickness of the support W is, for example, 10 μm to 100 μm. Moreover, the width | variety of the support body W is 300 mm-1500 mm, for example, and the length of the support body W is 100 m-5000 m. The thickness and width of the support W are appropriately selected according to the product to be applied. The support W may be referred to as a web, a film, or a sheet.

  The support W is composed mainly of at least one selected from cellulose acylate, cyclic olefin, acrylic resin, polyethylene terephthalate resin, and polycarbonate resin. In addition to the above-mentioned main component resin, the support W can contain, for example, a plasticizer, an ultraviolet absorber and the like.

<Coating solution>
In the present embodiment, as the coating liquid 20, a coating liquid having a viscosity of 7 mPa · s or more is used. There is no problem if the coating liquid has a viscosity of 7 mPa · s or more, but the upper limit of the viscosity is about 150 mPa · s in order to perform the coating through the slit of the die coater. The viscosity of the coating solution 20 was measured at 25 ° C. using a vibration viscometer (manufactured by A & D Co., Ltd., model name: SV-1A).

  Although the coating liquid 20 is not specifically limited, For example, the coating liquid for forming a low moisture-permeable layer can be illustrated. As a coating solution for the low moisture permeable layer, it contains a compound having a cyclic aliphatic hydrocarbon group and an unsaturated double bond group in the molecule, and if necessary, a polymerization initiator, a light transmissive property Particles, fluorine-containing or silicone compounds containing a solvent can be used.

  The cyclic aliphatic hydrocarbon group is preferably a group derived from an alicyclic compound having 7 or more carbon atoms, more preferably a group derived from an alicyclic compound having 10 or more carbon atoms, and further preferably Is a group derived from an alicyclic compound having 12 or more carbon atoms. The cycloaliphatic hydrocarbon group is particularly preferably a group derived from a polycyclic compound such as bicyclic or tricyclic.

Examples of the unsaturated double bond group include polymerizable functional groups such as a (meth) acryloyl group, a vinyl group, a styryl group, and an allyl group, and among them, a (meth) acryloyl group and —C (O) OCH═CH _2. Is preferred. Particularly preferably, a compound containing three or more (meth) acryloyl groups in one molecule described below can be used.

  As the polymerization initiator, a photopolymerization initiator is preferable. As photopolymerization initiators, acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, disulfide compounds, Examples include fluoroamine compounds, aromatic sulfoniums, lophine dimers, onium salts, borate salts, active esters, active halogens, inorganic complexes, and coumarins.

  As the solvent, various solvents can be used in consideration of the solubility of the monomer, the drying property during coating, the dispersibility of the translucent particles, and the like. Examples of the organic solvent include dibutyl ether, dimethoxyethane, diethoxyethane, propylene oxide, 1,4-dioxane, 1,3-dioxolane, 1,3,5-trioxane, tetrahydrofuran, anisole, phenetole, dimethyl carbonate, and methyl carbonate. Ethyl, diethyl carbonate, acetone, methyl ethyl ketone (MEK), diethyl ketone, dipropyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone, ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate, propyl acetate, propion Acid methyl, ethyl propionate, γ-ptyrolactone, methyl 2-methoxyacetate, methyl 2-ethoxyacetate, ethyl 2-ethoxyacetate, ethyl 2-ethoxypropionate, 2-methoxy Tanol, 2-propoxyethanol, 2-butoxyethanol, 1,2-diacetoxyacetone, acetylacetone, diacetone alcohol, methyl acetoacetate, methyl acetoacetate and other methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butyl alcohol, cyclohexyl alcohol , Isobutyl acetate, methyl isobutyl ketone (MIBK), 2-octanone, 2-pentanone, 2-hexanone, ethylene glycol ethyl ether, ethylene glycol isopropyl ether, ethylene glycol butyl ether, propylene glycol methyl ether, ethyl carbitol, butyl carbitol, Hexane, heptane, octane, cyclohexane, methylcyclohexane, ethylcyclohexane, benzene, toluene Xylene and the like, and can be used singly or in combination of two or more.

  A solvent is used so that the concentration of the solid content of the composition mainly composed of a compound having a cyclic aliphatic hydrocarbon group and an unsaturated double bond group in the molecule is in the range of 20% by mass to 80% by mass. More preferably, it is 30 mass%-75 mass%, More preferably, it is 40 mass%-70 mass%.

  Moreover, the coating liquid for forming the organic layer of a gas barrier film as another coating liquid 20 can be illustrated. Polyester, acrylic resin, methacrylic resin, methacrylic acid-maleic acid copolymer, polystyrene, transparent fluororesin, polyimide, fluorinated polyimide, polyamide, polyamideimide, polyetherimide, cellulose acylate, polyurethane, polyetheretherketone, polycarbonate , Alicyclic polyolefin, polyarylate, polyethersulfone, polysulfone, fluorene ring modified polycarbonate, alicyclic modified polycarbonate, fluorene ring modified polyester, acryloyl compound, and other thermoplastic resins, polysiloxane, other organosilicon compounds, etc. The coating liquid containing can be used.

  A coating liquid containing an acrylic resin or a methacrylic resin mainly composed of a polymer of a radically polymerizable compound and / or a cationic polymerizable compound having an ether group as a functional group, or an acrylate and / or methacrylate monomer or oligomer. Can be used. Among these, acrylates having two or more functional groups such as dipropylene glycol di (meth) acrylate (DPGDA), trimethylolpropane tri (meth) acrylate (TMPTA), dipentaerythritol hexa (meth) acrylate (DPHA), and the like. In addition, a coating solution containing an acrylic resin or a methacrylic resin whose main component is a methacrylate monomer or oligomer polymer can be used.

<Coating film formation process>
The coating film formation process 4 of this Embodiment is demonstrated with reference to FIGS. FIG. 2 is a partially enlarged perspective view of the die coater 400, the backup roller 420, and the decompression chamber 440. FIG. 3 is a plan view of the die coater 400 as seen from above. FIG. 4 is a graph showing the relationship between the distance L1 (μm) and the wind speed (m / s) in the decompression chamber. FIG. 5 is a schematic view showing the measurement position of the wind speed in FIG. FIG. 6 is a side view of the die coater 400 viewed from the side.

  A die coater is generally a coating apparatus that forms a coating film on a substrate such as a support through a manifold formed on the die block main body and a slit communicating with the manifold. Say.

  The die coater 400 in the present embodiment includes a first block 404 and a second block 406. The first block 404 and the second block 406 constitute a die block body 408. The first block 404 and the second block 406 are configured to form the slit 402 and the manifold 410 when combined.

  The manifold 410 is a space formed inside the die block body 408 and extending along the width direction of the die coater 400. The coating liquid 20 is temporarily stored in the manifold 410. The slit 402 is a space that communicates with the manifold 410 and extends from the manifold 410 toward the tip of the die coater 400 along the width direction of the die coater 400. The slit 402 is opened to the outside at the tip of the die coater 400 and serves as a discharge port for discharging the coating liquid 20. The first block 404 and the second block 406 are made of a material such as stainless steel (SUS), for example. In this embodiment, the die block main body 408 is composed of a first block 404 and a second block 406. However, the die block body 408 can be composed of one block or three or more blocks.

  Spacers 412 are disposed at both ends of the slit 402 of the die coater 400 in the width direction. The length in the width direction of the slit 402 is determined by the spacers 412 at both ends of the slit 402, and the length in the width direction of the coating film 24 is defined.

  A backup roller 420 is disposed at a position facing the tip of the die coater 400. The backup roller 420 includes a columnar main body and rotating shafts disposed at both ends of the main body. Since the backup roller 420 is configured to be rotatable, the support W can be wound around and continuously conveyed.

  The main body of the backup roller 420 has a diameter of φ200 mm to φ1000 mm, for example. There is no restriction on the diameter of the backup roller 420. Considering the equipment cost and the rotation accuracy, the diameter is preferably from 300 mm to 500 mm. By attaching a temperature controller to the main body of the backup roller 420, the temperature of the backup roller 420 can be adjusted.

  A decompression chamber 440 is disposed at a position upstream of the die coater 400. The decompression chamber 440 includes two side plates 442 arranged to face each other in the width direction of the support W, a first plate 448, a second plate 450, and a third plate 452 provided between the two side plates 442. have. The decompression chamber 440 has a shape in which a surface facing the backup roller 420 is opened. The side plate 442 has an arcuate portion 442 A that matches the curvature of the backup roller 420 at a portion facing the backup roller 420. The side plate 442 and the backup roller 420 are spaced apart by a distance L1. Here, the distance L <b> 1 refers to the distance between the backup roller 420 and the arc-shaped portion 442 </ b> A of the side plate 442 disposed to face the backup roller 420. Here, the “arc shape” does not have to be strictly a partial shape of the circumference, and may be a shape similar to the partial shape of the circumference. When the arc-shaped portion 442A has a shape matching the curvature of the backup roller 420, the distance L1 is constant on the arc-shaped portion 442A. On the other hand, when the distance L1 is not constant on the arc-shaped portion 442A, the distance L1 is represented by the distance L1 at a position corresponding to the tip of the slit 402 of the die coater 400. The distance L1 can be adjusted by adjusting the arrangement position of the decompression chamber 440 and the backup roller 420.

  As described above, the inside of the decompression chamber 440 is decompressed from the atmospheric pressure by the blower 444 (see FIG. 1). In order to express the degree of the state of being depressurized from the atmospheric pressure, the degree of depressurization is used in the present embodiment. The degree of decompression means a pressure difference between the decompressed pressure in the decompression chamber 440 and the atmospheric pressure, and is expressed as a positive number when the pressure is lower than the atmospheric pressure. The degree of decompression in the decompression chamber 440 can be measured with a Manostar gauge (manufactured by Yamamoto Electric Co., Ltd., model name: WO81FN-1000D).

  As described above, the slit 402 defines the length of the coating film 24 in the width direction, and the end of the coating film 24 is separated from the side plate 442 by the distance L2. The distance L <b> 2 refers to the distance between the extended surface of the inner wall surface 442 </ b> B of the side plate 442 and the end in the width direction of the coating film 24. For example, the distance L2 can be adjusted by adjusting the length of the spacer 412 in the width direction (the width direction of the support W).

  Next, the operation of the present embodiment will be described.

  In the above-described coating film forming step, the present inventors have formed a coating film using a coating liquid having a viscosity of 7 mPa · s or more. It became thicker than the film thickness, and it was found that there was a problem of poor appearance and breakage when wound up as a film roll. Here, the edge area of the coating film means an area within 1 mm inside the width direction from the edge of the coating film, and the steady area of the coating film means an area excluding the edge of the coating film. The film thickness in the end region of the coating film refers to the film thickness of the highest part in the end region, and the film thickness in the steady part region of the coating film is a constant pitch from one end to the other end of the steady region. The average value of the film thickness measured at 10 points. The film thickness of the coating film can be measured with a light interference film thickness meter.

  When a coating film is formed using a coating solution having a viscosity lower than 7 mPa · s, for example, 3 mPa · s, the coating film tends to spread out. Therefore, the difference between the film thickness in the end region of the coating film and the film thickness in the steady region of the coating film is relatively small. On the other hand, a coating film having a viscosity of 3 mPa · s is susceptible to disturbance (for example, the degree of reduced pressure, wind, etc.), and a level difference is likely to occur on the surface of the coating film. Therefore, the degree of decompression in the decompression chamber is reduced, or the distance L1 between the side plate and the backup roller is reduced in order to prevent the suction of wind. This is to reduce the influence of disturbance and prevent a step from being formed on the surface of the coating film.

  On the other hand, when the coating film 24 is formed using the coating liquid 20 having a viscosity of 7 mPa · s or more used in the present embodiment, the coating film 24 is difficult to spread. That is, it becomes difficult to be affected by disturbances (for example, the degree of decompression, wind, etc.). Therefore, the difference between the film thickness in the end region of the coating film 24 and the film thickness in the steady region of the coating film 24 tends to increase.

  Therefore, the inventors examined the degree of decompression of the decompression chamber 440. As a result, when the coating film 24 was formed, the degree of vacuum in the vacuum chamber 440 was set to 500 Pa to 900 Pa. By setting the degree of vacuum to 500 Pa to 900 Pa, the meniscus radius at the end in the width direction of the coating bead 22 becomes smaller due to the pressure balance of the meniscus (gas-liquid interface), and the end in the width direction of the coating bead 22 collapses. There was found. When the end portion of the coating bead 22 in the width direction collapses, a part of the coating solution 20 is scraped back along the tip of the die coater 400, and the amount of liquid at the end portion of the coating bead 22 decreases. It has been found that the film thickness in the end region of the coating film 24 can be suppressed from increasing in the range of 1 mm or less from the end of the coating film 24 to the inner side in the width direction.

  Furthermore, the distance L1 between the side plate 442 and the backup roller 420 was set in the range of 100 μm to 1500 μm, and the distance L2 between the side plate 442 and the end portion in the width direction of the coating film 24 was set in the range of 5 mm to 200 mm. By setting the distance L1 in the above-described range, the outside air (so-called wind) taken into the decompression chamber 440 can be increased from the gap (distance L1) between the side plate 442 and the backup roller 420.

  As shown in FIG. 4, when the degree of decompression in the decompression chamber 440 was 600 Pa, the distance L1 (μm) was changed to measure the wind speed at the center of the coating film and at the edge of the coating film. According to the graph, it can be understood that if the distance L1 (μm) is increased, the wind speed at the edge of the coating can be increased. On the other hand, the wind speed was almost constant at the center of the coating film. That is, even if the distance L1 (μm) is increased, it can be understood that the center of the coating film is not affected by the outside air (wind).

  As shown in the plan view of FIG. 5 (A), the measurement of the wind speed at the coating central portion and the coating end portion in FIG. 4 is performed at the positions of the central portion P1 of the coating film 24 and the end portion P2 of the coating film 24. As shown in the side view of FIG. 5B, the measurement was performed at a position 2 mm below the clearance between the die coater 400 and the support W. When the distance between the central portion P1 of the coating film 24 and the end portion P2 of the coating film 24 is doubled, the coating width of the coating film 24 is obtained. The clearance was 140 μm. A hot-wire anemometer head was installed at the position of the central portion P1 and the end portion P2. While changing the degree of decompression in the decompression chamber 440, the wind speed at the position of the central portion P1 and the end portion P2 was measured, and the measured value was recorded.

  By setting the distance L2 within the above-described range, it is possible to efficiently apply outside air to the end portion of the application bead 22. By increasing the pressure of the outside air sprayed on the meniscus (gas-liquid interface) at the end of the coating bead 22, the amount of scraping of the coating liquid 20 can be increased. Since the amount of the end portion of the coating liquid 20 discharged onto the support W can be reduced, the difference between the film thickness H1 in the end region of the coating film 24 and the film thickness H2 in the steady region of the coating film 24 is reduced. (Fig. 3).

  In the present embodiment, the case where the value of (H1−H2) / H2 × 100 (%) is 0% or more and 10% or less indicates that there is no difference between the film thickness of the end region and the film thickness of the steady region. "When the difference between the film thickness of the edge region and the film thickness of the stationary region is small" when it is greater than 10% and less than or equal to 20%. Is defined as "there is a clear difference between the film thickness of the end region and the film thickness of the steady region". .

  Further, as shown in FIG. 6, the discharge angle θ of the coating liquid 20 discharged from the slit 402 of the die coater 400 was set to −90 ° to 0 °. By setting the discharge angle θ to −90 ° to 0 °, the coating liquid 20A scraped back from the end of the coating bead 22 is prevented from adhering to the first surface W1 side of the support W. be able to. Here, the discharge angle θ refers to an angle formed by the discharge extension direction of the slit 402 and a horizontal line in a side view. When the discharge extension direction of the slit 402 is downward with respect to the horizontal line, the discharge angle θ is positive, and when the discharge extension direction of the slit 402 is upward with respect to the horizontal line, the discharge angle θ is negative.

  Each numerical range will be further described in the examples.

  The present invention will be described more specifically with reference to the following examples. The materials, production conditions, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the following specific examples.

The film with a coating film was manufactured on various conditions using the manufacturing line 1 shown by FIG. A triacetyl cellulose film (manufactured by FUJIFILM Corporation: TAC film) having a thickness of 40 μm and a width of 300 mm was used as a support, and the film was conveyed at a speed of 30 m / min. As the coating solution, the following coating solution for a low moisture-permeable layer was prepared. The prepared coating solution was applied to a support from a die coater to form a coating film having a thickness of 30 μm. Next, the coating film formed on the support was dried at 60 ° C. for 60 seconds. Next, the dried coating film is irradiated with ultraviolet rays from an ultraviolet irradiation device (air-cooled metal halide lamp (200 W / cm, emission length: 450 mm, irradiation amount: 600 mJ / cm ² )), and the coating film is cured to reduce the thickness. A moisture permeable layer was formed. Finally, the 3000 m support was wound on a film roll.

[Preparation of coating solution for low moisture permeable layer]
KR-614 (Arakawa Chemical Industries, Ltd.) 15 parts by mass A-DCP (Shin Nakamura Chemical Co., Ltd.) 73.8 parts Byron UR1510 (Toyobo Co., Ltd.) 8.2 parts by mass Irgacure 907 ( Ciba Specialty Chemicals Co., Ltd.) 3 parts by mass BYK-323 (manufactured by Big Chemie Japan Co., Ltd.) 0.02 parts by mass The solvent was added so that the solid content concentration was 55 parts by mass. The viscosity of the coating solution was 10 mPa · s. In addition, the viscosity of the coating liquid was adjusted by adjusting the addition amount of KR-614. The viscosity can be increased by increasing the amount of KR-614 added.

(Solvent composition)
MEK (methyl ethyl ketone) 30 parts by mass MIBK (methyl isobutyl ketone) 70 parts by mass The materials used are shown below.
KR-614: Rosin derivative A-DCP: Tricyclodecanedimethanol dimethacrylate Byron (registered trademark) UR1510: Polyester urethane resin Irgacure (registered trademark) 907: 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one (polymerization initiator)
BYK (registered trademark) -323: Aralkyl-modified polymethylalkylsiloxane (Example 1)
The viscosity of the coating solution is 7 mPa · s, the degree of vacuum in the vacuum chamber is 500 Pa, the distance L1 between the side plate and the backup roller is 300 μm, and the distance L2 between the side plate and the end in the width direction of the coating film is 50 mm. The discharge angle θ of the coating liquid discharged from the slit was set to −20 °, and the coating liquid was discharged from the die coater to form a coating film on the support.

(Example 2)
A coating film was formed on the support under the same conditions as in Example 1 except that the viscosity of the coating solution was 10 mPa · s.

(Example 3)
A coating film was formed on the support under the same conditions as in Example 1 except that the viscosity of the coating solution was 100 mPa · s. The viscosity of the coating solution was adjusted by adjusting the amount of KR-614 added.

Example 4
The viscosity of the coating liquid is 10 mPa · s, the degree of vacuum in the vacuum chamber is 900 Pa, the distance L1 is 300 μm, the distance L2 is 50 mm, the discharge angle θ is −20 °, and the coating liquid is discharged from the die coater. A coating was formed on top.

(Example 5)
The viscosity of the coating liquid is 10 mPa · s, the degree of vacuum in the vacuum chamber is 800 Pa, the distance L1 is 100 μm, the distance L2 is 50 mm, the discharge angle θ is −20 °, and the coating liquid is discharged from the die coater. A coating was formed on top.

(Example 6)
A coating film was formed on the support under the same conditions as in Example 5 except that the distance L1 was 1000 μm.

(Example 7)
A coating film was formed on the support under the same conditions as in Example 5 except that the distance L1 was 1500 μm.

(Example 8)
The viscosity of the coating liquid is 10 mPa · s, the degree of vacuum in the vacuum chamber is 800 Pa, the distance L1 is 300 μm, the distance L2 is 5 mm, the discharge angle θ is −20 °, and the coating liquid is discharged from the die coater. A coating was formed on top.

Example 9
A coating film was formed on the support under the same conditions as in Example 8 except that the distance L2 was set to 100 mm.

(Example 10)
A coating film was formed on the support under the same conditions as in Example 8 except that the distance L2 was 200 mm.

(Example 11)
The viscosity of the coating liquid is 10 mPa · s, the degree of vacuum in the vacuum chamber is 800 Pa, the distance L1 is 300 μm, the distance L2 is 50 mm, the discharge angle θ is −5 °, and the coating liquid is discharged from the die coater. A coating was formed on top.

(Example 12)
A coating film was formed on the support under the same conditions as in Example 11 except that the discharge angle θ was set to 0 °.

(Example 13)
A coating film was formed on the support under the same conditions as in Example 11 except that the discharge angle θ was −90 °.

(Comparative Example 1)
A coating film was formed on the support under the same conditions as in Example 1 except that the viscosity of the coating solution was 3 mPa · s.

(Comparative Example 2)
A coating film was formed on the support under the same conditions as in Example 4 except that the degree of vacuum was 300 Pa.

(Comparative Example 3)
A coating film was formed on the support under the same conditions as in Example 5 except that the distance L1 was 50 μm.

(Comparative Example 4)
A coating film was formed on the support under the same conditions as in Example 8 except that the distance L2 was 300 mm.

(Comparative Example 5)
A coating film was formed on the support under the same conditions as in Example 11 except that the discharge angle θ was 45 °.

<Evaluation>
The film roll which wound up the support body which has a low moisture-permeable layer was evaluated. Evaluation was performed about the difference of the film thickness of the edge part area | region and film thickness of a stationary part area | region in a low moisture-permeable layer, and the external appearance of the film roll.

  There is no difference between the film thickness of the edge area and the film thickness of the steady area, and A is the case where the film roll can be wound without any problem, and there is a little difference between the film thickness of the edge area and the film thickness of the steady area. However, when the film roll can be wound without any problem as B, the film thickness of the end region and the film thickness of the steady region is different, and C is the case where there is a problem with the roll shape of the film roll. The film thickness of the film portion and the film thickness of the steady region are clearly different, and D is the case where the film roll breaks.

  Regarding the appearance of the film roll, it can be determined that there is no problem when the end portion can be visually determined to be the same as the center portion, and it can be determined by visual inspection that the end portion is stuck and a black belt is generated. The case was defined as “There is a problem with the winding shape”, and there was a risk of breakage.

<Evaluation results>
Table 1 shows the conditions and evaluation results when forming the coating film.

  According to Example 1-3 and Comparative Example 1, evaluation of A or B was obtained in the range where the viscosity of the coating solution was 7 mPa · s or more and 100 mPa · s or less. Moreover, according to Example 5-7 and Comparative Example 3, evaluation of A or B was obtained in the range where the distance L1 was 100 μm or more and 1500 μm or less. According to Examples 8-10 and Comparative Example 4, the evaluation of A or B was obtained in the range where the distance L2 was 5 mm or more and 200 mm or less. According to Examples 11-13 and Comparative Example 5, the evaluation of A or B was obtained in the range where the discharge angle θ was 0 ° or less and −90 ° or more. According to Examples 2 and 4 and Comparative Example 2, the evaluation of A or B was obtained in a range of the degree of reduced pressure from 500 Pa to 900 Pa.

  According to Table 1, according to this invention, the difference of the film thickness of the edge part area | region of a coating film and the film thickness of the stationary part area | region of a coating film can be made small, and the external appearance defect and fracture | rupture of a film roll can be suppressed. .

  DESCRIPTION OF SYMBOLS 1 ... Production line, 20 ... Coating liquid, 22 ... Coating bead, 24 ... Coating film, 400 ... Die coater, 402 ... Slit, 420 ... Backup roller, 440 ... Decompression chamber, 442 ... Side plate, L1 ... Side plate and backup roller , L2 ... distance between the side plate and the end of the coating film in the width direction, W ... support, W1 ... first surface, W2 ... second surface, θ ... discharge angle of coating liquid

Claims (6)

A delivery step of continuously delivering a long support having a first surface and a second surface;
A coating liquid having a viscosity of 7 mPa · s or more is applied to the first surface side of the support through the slit of the die coater while the second surface side of the support is wound around a backup roller and conveyed. Forming a coating bead between the tip of the die coater and the first surface side of the support, and forming a coating film on the first surface side of the support; A method for producing a film with a coating film, comprising:
A pressure reducing chamber including two side plates opposed to each other in the width direction of the support at a position upstream of the die coater;
The distance L1 between the side plate and the backup roller is in the range of 100 μm to 1500 μm,
The distance L2 between the side plate and the end in the width direction of the coating film is in the range of 5 mm to 200 mm,
The degree of vacuum in the vacuum chamber is in the range of 500 Pa to 900 Pa,
The manufacturing method of the film with a coating film whose discharge angle (theta) of the said coating liquid discharged from the said slit is -90 degree-0 degree.   The manufacturing method of the film with a coating film of Claim 1 whose viscosity of the said coating liquid is the range of 10 mPa * s-100 mPa * s.   The manufacturing method of the film with a coating film of Claim 1 or 2 whose said distance L1 is the range of 300 micrometers-1500 micrometers.   The said distance L1 is the range of 1000 micrometers-1500 micrometers, The manufacturing method of the film with a coating film of Claim 3.   The said distance L2 is the range of 5 mm-100 mm, The manufacturing method of the film with a coating film as described in any one of Claim 1 to 4.   The coating method according to any one of claims 1 to 5, further comprising a drying step of drying the coating film and an actinic ray irradiation step of irradiating the dried coating film with actinic rays after the coating film forming step. Manufacturing method of film with film.

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