WO2014208183A1 - Method for manufacturing electromagnetic-wave-shielding film - Google Patents

Method for manufacturing electromagnetic-wave-shielding film Download PDF

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Publication number
WO2014208183A1
WO2014208183A1 PCT/JP2014/060960 JP2014060960W WO2014208183A1 WO 2014208183 A1 WO2014208183 A1 WO 2014208183A1 JP 2014060960 W JP2014060960 W JP 2014060960W WO 2014208183 A1 WO2014208183 A1 WO 2014208183A1
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WIPO (PCT)
Prior art keywords
refractive index
coating
bar
index layer
coating liquid
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Application number
PCT/JP2014/060960
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French (fr)
Japanese (ja)
Inventor
川邉　茂寿
篤志 齋藤
Original Assignee
コニカミノルタ株式会社
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Application filed by コニカミノルタ株式会社 filed Critical コニカミノルタ株式会社
Priority to CN201480036725.4A priority Critical patent/CN105340375A/en
Priority to JP2015523902A priority patent/JPWO2014208183A1/en
Publication of WO2014208183A1 publication Critical patent/WO2014208183A1/en

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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K9/00—Screening of apparatus or components against electric or magnetic fields
    • H05K9/0073—Shielding materials
    • H05K9/0094—Shielding materials being light-transmitting, e.g. transparent, translucent
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K9/00—Screening of apparatus or components against electric or magnetic fields
    • H05K9/0073—Shielding materials
    • H05K9/0081—Electromagnetic shielding materials, e.g. EMI, RFI shielding
    • H05K9/0088—Electromagnetic shielding materials, e.g. EMI, RFI shielding comprising a plurality of shielding layers; combining different shielding material structure
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C5/00—Apparatus in which liquid or other fluent material is projected, poured or allowed to flow on to the surface of the work
    • B05C5/007—Slide-hopper coaters, i.e. apparatus in which the liquid or other fluent material flows freely on an inclined surface before contacting the work
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05C9/00—Apparatus or plant for applying liquid or other fluent material to surfaces by means not covered by any preceding group, or in which the means of applying the liquid or other fluent material is not important
    • B05C9/06—Apparatus or plant for applying liquid or other fluent material to surfaces by means not covered by any preceding group, or in which the means of applying the liquid or other fluent material is not important for applying two different liquids or other fluent materials, or the same liquid or other fluent material twice, to the same side of the work

Definitions

  • the present invention relates to a method for producing an electromagnetic wave shielding film.
  • the electromagnetic wave shielding film is configured by alternately laminating high refractive index layers and low refractive index layers.
  • high refractive index layers and low refractive index layers increase, the reflectivity of electromagnetic waves increases and the shielding effect increases. Therefore, there is a problem in productivity (for example, see Patent Documents 1 and 2). Therefore, in order to improve productivity, application of a slide type die coater capable of performing multilayer coating (simultaneous multilayer coating) at once has been proposed.
  • the number of bars (number of coating layers) constituting the slide type die coater corresponds to the number of layers of the electromagnetic wave shielding film to be manufactured (number of high refractive index layers and low refractive index layers). Therefore, when increasing the number of coating layers in order to increase the number of layers of the electromagnetic shielding film to be manufactured, the number of bars installed increases, and the slide surface constituted by the end surfaces of the bars through which the coating liquid flows down becomes long. As a result, the flow of the coating liquid is likely to be disturbed, making uniform coating difficult, and mixing of the coating liquid may adversely affect the electromagnetic wave shielding film, for example, non-uniformity (fluctuation) in film thickness and performance. There was a risk of causing a drop.
  • the bar is pressurized and deformed from the higher pressure (the side through which the low refractive index layer coating solution having a higher viscosity passes) to the lower side (the side through which the high refractive index layer coating solution having a lower viscosity passes). Since the uniformity of the gap in the coating width direction is deteriorated, the coating film thickness becomes non-uniform, the uniformity of the optical characteristics of the electromagnetic wave shielding film to be manufactured is lowered, and, for example, the problem of color unevenness occurs.
  • the present invention has been made in order to solve the problems associated with the above-described conventional technology, and an object thereof is to provide a method for producing an electromagnetic wave shielding film capable of satisfactorily performing simultaneous multilayer coating even when the number of layers is increased.
  • the first coating liquid coating layer that constitutes the high refractive index layer and the second coating that constitutes the low refractive index layer is located between a tip portion that forms a gap with another adjacent bar, a base end portion that contacts the other bar, and the tip portion and the base end portion.
  • the pressure difference between the internal pressure of the concave portion of the pocket portion of the bar supplied with the second coating liquid and the internal pressure of the concave portion of the pocket portion of the bar supplied with the first coating liquid is 0.1 MPa.
  • Slit gap D 31 [mm] which is the thickness of the gap at the tip of the bar to which the first coating liquid is supplied and the slit which is the thickness of the gap at the tip of the bar to which the second coating liquid is supplied
  • the gap D 32 [mm] is 0.05 or more and 0.4 or less, and
  • the slit gap D 32 is the manufacturing method of the electromagnetic wave shielding film according to the slit gap D 31 is greater than the above (1).
  • Viscosity ⁇ 1 [mPa ⁇ s] of the first coating solution is 3 or more and 30 or less
  • Viscosity ⁇ 2 [mPa ⁇ s] of the second coating liquid is the method for producing an electromagnetic wave shielding film according to (2), which is 50 or more and 500 or less.
  • the thickness of the pocket portion of the bar is 15 mm or less, the bar can be thinned, and the end surface of the bar where the coating liquid flows down even when the number of installed bars (number of coating layers) is increased. It is suppressed that the slide surface comprised by becomes long.
  • the pressure difference between the internal pressure of the concave portion of the pocket portion of the bar supplied with the second coating liquid and the internal pressure of the concave portion of the pocket portion of the bar supplied with the first coating liquid is 0.1 MPa or less. It is set to be.
  • FIG. 5 is a cross-sectional view taken along line VV in FIG. 4. It is sectional drawing for demonstrating the application
  • FIG. 1 is a flowchart for explaining a method of manufacturing an electromagnetic wave shielding film according to an embodiment of the present invention.
  • An electromagnetic wave shielding film is formed by alternately laminating a plurality of high refractive index layers and low refractive index layers, has high transmittance in the visible light region (wavelength 380 to 780 nm), and is near-red. It has optical characteristics with high reflectivity in the outside light region (780-2500 nm).
  • the electromagnetic wave shielding film is used as a near-infrared light reflecting film, and is disposed in an outdoor window of a building, an automobile window, an agricultural greenhouse, and the like, and is used for imparting a heat ray reflecting effect.
  • High refractive index layer and “low refractive index layer” when comparing the refractive index difference between two adjacent layers, the higher refractive index layer is the high refractive index layer, the lower one is the low refractive index layer Means.
  • the reflectance in the specific wavelength region is determined by the refractive index difference between two adjacent layers and the number of layers. The larger the refractive index difference, the higher the reflectance can be obtained with a smaller number of layers.
  • the method for manufacturing an electromagnetic wave shielding film according to the embodiment of the present invention includes a preparation step, a coating step, and a drying step, as shown in FIG.
  • a high refractive index layer coating solution and a low refractive index layer coating solution are prepared by mixing metal oxide particles, a resin binder, a curing agent, an additive, a solvent, and the like.
  • the high refractive index layer coating liquid and the low refractive index layer coating liquid corresponding to each layer of the electromagnetic wave shielding film are collectively coated (simultaneous multilayer coating) on the film substrate.
  • polyolefin film As the film substrate, various resin films such as polyolefin film, polyester film, polyvinyl chloride film, and cellulose acetate film can be applied.
  • Polyolefin is, for example, polyethylene or polypropylene.
  • polyester examples include polyethylene terephthalate and polyethylene naphthalate.
  • an electromagnetic wave shielding film is produced by drying (thermosetting) the film substrate on which the high refractive index layer coating solution and the low refractive index layer coating solution are applied in multiple layers.
  • the drying conditions are appropriately set in consideration of the evaporation temperature of the volatile components contained in the high refractive index layer coating solution and the low refractive index layer coating solution, the curing temperature of the curing agent, the heat resistant temperature of the film substrate, and the like. .
  • the dried electromagnetic shielding film is then cut into an appropriate size as necessary.
  • the metal oxide particles of the high refractive index layer coating liquid are, for example, titanium dioxide, zirconium oxide, zinc oxide, alumina, colloidal alumina, lead titanate, red lead, yellow lead, zinc yellow, chromium oxide, second oxide. They are iron, iron black, copper oxide, magnesium oxide, magnesium hydroxide, strontium titanate, yttrium oxide, niobium oxide, europium oxide, lanthanum oxide, zircon and tin oxide.
  • the metal oxide particles of the high refractive index layer coating solution preferably contain titanium oxide fine particles and zirconia oxide fine particles. The concentration of the metal oxide particles is, for example, 1 to 50% by mass.
  • the metal oxide particles of the low refractive index layer coating solution are, for example, silicon dioxide and colloidal silica.
  • the concentration of the metal oxide particles is, for example, 1 to 50% by mass.
  • Resin binders are, for example, polyvinyl alcohol, gelatin, water-soluble cellulose derivatives, thickening polysaccharides, and polymers having reactive functional groups.
  • concentration of the resin binder in the high refractive index layer coating solution is, for example, 0.5 to 10% by mass.
  • concentration of the resin binder in the low refractive index layer coating solution is 1 to 10% by mass.
  • the curing agent is not particularly limited as long as it causes a curing reaction with the resin binder.
  • the curing agent is, for example, boric acid and its salt.
  • Additives are, for example, ultraviolet absorbers, fading inhibitors, surfactants, fluorescent brighteners, pH adjusters, antifoaming agents, lubricants, preservatives, and antistatic agents.
  • the solvent is, for example, water, an organic solvent, or a mixed solution thereof.
  • the organic solvent is methanol, ethanol, ethyl acetate or the like.
  • FIG. 2 is a schematic view for explaining a coating apparatus applied to the preparation step and the coating step shown in FIG. 1
  • FIG. 3 is a plan view for explaining a side wall portion of the die coater shown in FIG. 4 is a plan view for explaining the bar of the die coater shown in FIG. 2
  • FIG. 5 is a cross-sectional view taken along line VV in FIG.
  • the coating apparatus 10 includes a transport system 20, a die coater 30, a coating liquid supply system 70, and pressure sensors 81 and 82.
  • the conveyance system 20 includes a film base material 22 and a back roll 24.
  • the film substrate 22 is a belt-like support on which the coating liquid L is applied.
  • the back roll 24 is arranged inside the film base 22 and is configured to transport the film base 22 from the upstream side to the downstream side in the application direction (transport direction) F by being driven to rotate. ing.
  • the film base material 22 is heated up to predetermined temperature (for example, 30 degreeC or more) by a heating means (not shown).
  • the die coater 30 is a slide type, and is configured such that coating layers corresponding to the layers of the electromagnetic wave shielding film can be collectively applied (simultaneous multilayer coating). Have.
  • the stacked body 32 is configured by stacking a plurality of rectangular bars 40 in order.
  • the bar 40 is made of, for example, stainless steel, and includes a front bar 42, a plurality of intermediate bars 44, and a back bar 46, which have substantially the same shape.
  • the front bar 42 is a bar that occupies the lowermost layer of the laminate 32 and is positioned in the vicinity of the film substrate 22.
  • the back bar 46 is a bar that occupies the uppermost layer of the stacked body 32.
  • the intermediate bar 44 is a bar that occupies an intermediate layer located between the front bar 42 and the back bar 46.
  • the side wall part 60 is arrange
  • the constituent material of the bar 40 is not limited to stainless steel.
  • the application width direction W is orthogonal to the application direction (conveyance direction) F.
  • the bar 40 has a proximal end portion 50, a pocket portion 53, and a distal end portion 56 in order from the proximal end side.
  • the base end portion 50 has a through hole 52 communicating with the coating liquid supply system 70.
  • the through hole 52 is located in the center of the application width direction W of the base end portion 50 and extends from the end surface of the base end portion 50 toward the pocket portion 53.
  • a thickness D 1 of the proximal end portion 50 is set to be larger than a thickness D 2 of the distal end portion 56. Therefore, when the bars 40 are stacked, the base end portion 50 comes into contact with the base end portion 50 of another adjacent bar, while the front end portion 56 and the front end portion 56 of another adjacent bar are in between.
  • a slit (gap) 58 having a thickness D 3 ( D 1 ⁇ D 2 ) is formed. In the following, the thickness D 3 are referenced by the slit spacing D 3.
  • Reference numeral 51 denotes an end face of the base end portion 50.
  • the slit 58 functions as a passage through which the coating liquid passes. Since the coating liquid discharged from the front end of the slit 58 flows down the end surface 57 of the front end portion 56, the end surface 57 functions as a slide surface on which the coating liquid flows down.
  • the pocket portion 53 has a concave portion 54 formed to extend in the coating width direction W of the bar 40.
  • the recess 54 is a coating liquid reservoir that communicates with the slit 58 and the through hole 52.
  • the concave portion 54 is used to spread the coating liquid from the through-hole 52 (coating liquid supply system 70) evenly in the coating width direction W and stably supply it to the slit 58.
  • the thickness D 4 of the pocket portion 53 is set to 15mm or less. Therefore, it is possible to make the bar 40 thinner (thinner and lighter), and even if the number of installed bars 40 (the number of coating layers) is increased, an increase in the sliding surface is suppressed.
  • the die coater 30 can be reduced in size, space-saving, energy saving, equipment cost can be reduced, handling can be facilitated, workability can be improved, and coating failure can be expected.
  • the high-refractive index layer coating solution L 1 which is a first coating liquid constitutes the high refractive index layer and the low refractive index layer and thus the second coating liquid and the low-refractive index layer coating solution L 2, but are alternately introduced.
  • the low refractive index layer coating liquid L 2 is introduced into the through hole 52 of the front bar 42, and the high refractive index layer coating liquid L 1 is introduced into the through hole of the intermediate bar 44 adjacent to the front bar 42.
  • the through hole 52 of another intermediate bar 44 adjacent to the intermediate bar 44, the low refractive index layer coating solution L 2 is introduced.
  • the number of slits 58 is equal to the number of layers of the manufactured electromagnetic shielding film, and the number of intermediate bars 44 is adjusted according to the number of layers of the manufactured electromagnetic shielding film.
  • the sliding surface is the sum of the length of the end surface 57 of the front end portion 56 of the intermediate bar 44 and the front bar 42 in which two or more layers are stacked, and the thickness of the intermediate bar 44 excluding the uppermost layer and the front bar 42 It almost coincides with the total thickness.
  • Coating liquid supply system 70 is used to provide a low refractive index layer coating solution L 2 and the high-refractive index layer coating solution L 1 die coater 30, the preparation kettle 72 and 76, It has piping systems 73 and 77 and pumps 74 and 78.
  • Preparation kettle 72 a low refractive index layer coating solution L 2 is prepared, a predetermined temperature (e.g., 30 ° C. or higher) is a vessel used to hold in.
  • the piping system 73 connects the preparation kettle 72 and the through hole 52 of the base end portion 50 of the bar 40 for the low refractive index layer coating solution.
  • the pump 74 is used for pumping the prepared low refractive index layer coating liquid L 2 through the piping system 73.
  • Preparation kettle 76 the high refractive index layer coating solution L 1 was prepared, a predetermined temperature (e.g., 30 ° C. or higher) is a vessel used to hold in.
  • the piping system 77 connects the preparation pot 76 and the through hole 52 of the base end portion 50 of the bar 40 for the high refractive index layer coating solution.
  • Pump 78 via the piping system 77 is used which is prepared a high refractive index layer coating solution L 1 for pumping.
  • the pumps 74 and 78 are, for example, gear pumps or tube pumps.
  • the pressure sensors 81 and 82 are disposed in the piping systems 73 and 77 in the vicinity of the die coater 30 and are used for detecting a pressure difference. Pressure differential is detected, and the internal pressure of the recess 54 of the pocket portion 53 of the bar 40 having a low refractive index layer coating solution L 2 is supplied, the pocket section 53 of the bar 40 to the high refractive index layer coating solution L 1 is supplied Is set to be 0.1 MPa or less in the coating step.
  • the pressure sensors 81 and 82 can be disposed on the inner surface of the concave portion 54 of the pocket portion 53 or on the inner surface of the side wall portion 60 in contact with the concave portion 54 of the pocket portion 53, for example.
  • the pressure difference can also be detected directly by a differential pressure gauge.
  • FIG. 6 is a cross-sectional view for explaining a coating process according to an embodiment of the present invention
  • FIG. 7 is a cross-sectional view for explaining a coating condition in the coating process
  • FIG. 8 is for explaining a comparative example. It is sectional drawing.
  • the metal oxide particles for low refractive index layer, the resin binder, a curing agent, additives, solvents and the like after turning the preparation kettle 72, by mixing, the low refractive index layer coating solution L 2 while being prepared, the metal oxide particles for high refractive index layer, the resin binder, a curing agent, additives, solvents and the like, after turning the preparation kettle 76, by mixing, the high refractive index layer coating solution L 1 Prepared. Then, the low refractive index layer coating solution L 2 and the high-refractive index layer coating solution L 1 which is prepared is held at a predetermined temperature (e.g., 30 ° C. or higher).
  • a predetermined temperature e.g. 30 ° C. or higher.
  • the prepared low refractive index layer coating liquid L 2 and high refractive index layer coating liquid L 1 are pumped by pumps 74 and 78, and are connected to the low refractive index layer coating liquid via the piping systems 73 and 77.
  • the through hole 52 of the base end portion 50 of the bar 40 for use and the through hole 52 of the base end portion 50 of the bar 40 for the high refractive index layer coating solution are pumped by pumps 74 and 78, and are connected to the low refractive index layer coating liquid via the piping systems 73 and 77.
  • the high refractive index layer coating liquid L 1 and the low refractive index layer coating liquid L 2 are alternately introduced into the through holes 52 of the bar 40 according to the stacking position of the bars 40. Is done.
  • the low refractive index layer coating liquid L 2 is introduced into the through hole 52 of the front bar 42, and the high refractive index layer coating liquid L 1 is introduced into the through hole of the intermediate bar 44 adjacent to the front bar 42.
  • the through hole 52 of another intermediate bar 44 adjacent to the intermediate bar 44 the low refractive index layer coating solution L 2 is introduced.
  • the coating solution is spread evenly in the coating width direction W in the concave portion 54 of the pocket portion 53 and introduced into the slit 58.
  • the coating solution that has passed through the slit 58 flows down the end surface 57 of the tip portion 56 of the bar 40 and flows down the end surface 57 of the tip portion 56 of another bar 40 positioned below. And overlap one after another.
  • the coating liquid which flows down is comprised from the layer corresponding to the number of layers of the electromagnetic wave shielding film manufactured at the time of overlapping with the coating liquid which passed the slit 58 of the front bar 42.
  • the coating liquid L flows away (applied) to the film base material 22 that has been heated to a predetermined temperature (for example, 30 ° C. or more) apart from the front bar 42 that is the lowermost bar 40.
  • the thickness D 4 of the pocket portion 53 of the bar 40 is set to 15mm or less, a bar 40 which is thinner, even increasing installation speed of the bar 40 (the number of coating layer), the slide surface is long Is suppressed.
  • the viscosity ⁇ 1 of the high refractive index layer coating liquid L 1 is 3 mPa ⁇ s or more and 30 mPa ⁇ s or less.
  • the viscosity ⁇ 2 of the low refractive index layer coating liquid L 2 is 50 mPa ⁇ s or more and 500 mPa ⁇ s or less, which is one digit or more larger than the viscosity ⁇ 1 of the high refractive index layer coating liquid L 1 . Therefore, the internal pressure P 1 of the concave portion 54 to which the high refractive index layer coating liquid L 1 is supplied is smaller than the internal pressure P 2 of the concave portion 54 to which the low refractive index layer coating liquid L 2 is supplied, and is adjacent (adjacent). An internal pressure difference occurs between the bars 40.
  • the pressure difference ⁇ P between the internal pressure P 1 of the recess 54 of the pocket portion 53 of the bar 40 to which the rate layer coating liquid L 1 is supplied is set to be 0.1 MPa or less.
  • the pressure difference ⁇ P related to the pocket portion 53 that is the minimum thickness portion of the bar 40 and easily deforms due to the pressure is small, the deformation of the bar 40 is suppressed, and the uniformity of the gap in the coating width direction is maintained. Since the coating film thickness in the coating width direction is prevented from becoming non-uniform, the uniformity of the optical characteristics of the manufactured electromagnetic wave shielding film is good. That is, even when the number of layers is increased, simultaneous multilayer coating can be carried out satisfactorily.
  • the high refractive index layer coating liquid L 1 , the low refractive index layer coating liquid L 2 and the film substrate 22 are heated during coating. Therefore, the high refractive index layer coating liquid L 1 and the low refractive index layer coating liquid L 2 applied to the film base material 22 are once cooled to 1 to 15 ° C. and then put into a drying step, and 10 ° C. or higher. For example, drying is performed at a wet bulb temperature of 5 to 50 ° C. and an application surface temperature of 10 to 50 ° C.
  • FIG. 9 is a table showing test results for explaining the influence of the thickness of the bar pocket portion and the pressure difference on the film thickness fluctuation rate of the electromagnetic wave shielding film
  • FIG. 10 shows the film thickness fluctuation rate of the electromagnetic wave shielding film
  • FIG. 11 is a table showing test results for explaining the influence of the slit interval on the film thickness variation rate of the electromagnetic wave shielding film.
  • FIG. 11 is a table showing the test results for explaining the influence of the coating liquid viscosity on the pressure difference. It is.
  • the coating solution for the low refractive index layer is composed of 12 parts by mass of colloidal silica (Snowtex OXS, manufactured by Nissan Chemical Industries, Ltd., solid content 10% by mass), polyvinyl alcohol (PVA-103, polymerization degree 300, saponification degree 98.5 mol%, 2 parts by weight of a 5% by weight aqueous solution of Kuraray Co., Ltd. and 10 parts by weight of a 3% by weight aqueous boric acid solution were added, and the mixture was then heated to 45 ° C. and stirred while polyvinyl alcohol (PVA-117, polymerization degree 1700).
  • colloidal silica Snowtex OXS, manufactured by Nissan Chemical Industries, Ltd., solid content 10% by mass
  • PVA-103 polyvinyl alcohol
  • PVA-103 polymerization degree 300, saponification degree 98.5 mol%
  • the coating solution for the high refractive index layer is 5 parts of polyvinyl alcohol (PVA-103, polymerization degree 300, saponification degree 98.5 mol%, manufactured by Kuraray Co., Ltd.) in 30 parts by mass of silica-attached titanium dioxide sol (solid content 20.0% by mass). After adding 2 parts by weight of a 2% by weight aqueous solution, 10 parts by weight of a 3% by weight aqueous boric acid solution, and 10 parts by weight of a 2% by weight aqueous citric acid solution, the mixture was heated to 45 ° C.
  • PVA-103 polyvinyl alcohol
  • silica-attached titanium dioxide sol solid content 20.0% by mass
  • polyvinyl alcohol PVA- 617, polymerization degree 1700, saponification degree 95.0 mol%, manufactured by Kuraray Co., Ltd.
  • PVA- 617 polyvinyl alcohol
  • surfactant Rapizole A30, manufactured by NOF Corporation
  • the silica-attached titanium dioxide sol is composed of 15.0 mass% titanium oxide sol (SRD-W, volume average particle size 5 nm, rutile titanium dioxide particles, manufactured by Sakai Chemical Co., Ltd.) 0.5 mass parts, and 2 mass parts of pure water.
  • SRD-W volume average particle size 5 nm, rutile titanium dioxide particles, manufactured by Sakai Chemical Co., Ltd.
  • aqueous silicic acid solution a solution of sodium silicate 4 (manufactured by Nippon Chemical Co., Ltd.) diluted with pure water so that the SiO 2 concentration was 2.0 mass
  • heat treatment was performed at 175 ° C. for 18 hours in an autoclave. After cooling, the solution was concentrated by an ultrafiltration membrane.
  • the low-refractive index layer coating solution and the high-refractive index layer coating solution were kept at 45 ° C. and supplied to the die coater, and 15 layers were simultaneously coated.
  • the lowermost layer and the uppermost layer are low refractive index layers, and one low refractive index layer is included more than the high refractive index layer.
  • the film substrate was formed of a polyethylene terephthalate film (Toyobo Co., Ltd. A4300: double-sided easy-adhesion layer) having a thickness of 50 ⁇ m and a width of 2000 mm, and the temperature was raised to 45 ° C. during application of the coating solution.
  • the front bar and back bar of the die coater were 40 mm thick.
  • the coating speed and coating width were set to 50 m / min and 1950 mm.
  • the coating thickness of the low refractive index layer and the high refractive index layer was set to be 150 nm as an average film thickness during drying.
  • the film thickness fluctuation rate V [%] of the electromagnetic wave shielding film is a value obtained by dividing the film thickness fluctuation width by the film thickness average value and multiplying by 100.
  • the film thickness variation width is a difference between the minimum value and the maximum value of the film thickness.
  • the film thickness average value is an average value related to the entire width of the film thickness measured at intervals of 50 mm in the coating width direction.
  • the film thickness was measured for each layer.
  • a cross section of the electromagnetic wave shielding film manufactured under the above conditions can be observed with a length of 1 cm under the condition of an acceleration voltage of 2.0 kV using an electron microscope (FE-SEM, S-5000H type, manufactured by Hitachi, Ltd.).
  • FE-SEM, S-5000H type manufactured by Hitachi, Ltd.
  • the film thickness is an average value of 1000 measurement results.
  • the thickness D 4 of the pocket portion of the bars varied from 5 ⁇ 20 mm, and the pressure difference ⁇ P is in a range of 0.02 ⁇ 0.15 MPa by changing the supply amount of the low refractive index layer coating solution L 2 Changed.
  • the pressure difference ⁇ P is, the internal pressure P 2 of the recess of the pocket portion of the bar having a low refractive index layer coating solution L 2 is supplied, the recess of the pocket portion of the bar which high refractive index layer coating solution L 1 is supplied internal pressure P 1 and the pressure difference.
  • the slit gap was 0.2 mm, and the viscosity of the high refractive index layer coating solution and the low refractive index layer coating solution was set to 10 mPa ⁇ s and 100 mPa ⁇ s.
  • the thickness D 4 of the pocket portion of the bar is 20 mm, regardless of the pressure difference [Delta] P, the coating disturbance was observed.
  • the thickness D 4 of the pocket portion of the bar is 15mm or less, and, when the pressure difference ⁇ P is 0.1MPa or less, the coating film disturbance is not observed, the thickness variation rate (V) is 3.0% The following uniform coating film could be obtained.
  • the thickness D 4 of the pocket portion of the bar is preferably at least 5 mm.
  • the low refractive index layer coating solution viscosity ⁇ 2 was changed in the range of 50 to 2000 mPa ⁇ s, and the high refractive index layer coating solution viscosity ⁇ 1 was changed in the range of 1 to 30 mPa ⁇ s.
  • the thickness D 4 of the pocket portion of the bar 12,5Mm, slit gap D 3 was set to 0.2 mm.
  • the adjustment method of a viscosity is not specifically limited, For example, it can adjust by changing the ratio of a solvent and a binder.
  • the film thickness variation rate (V) exceeds 3.0% and the film thickness variation rate (V) is 3.0% or less.
  • the pressure difference ⁇ P was 0.1 MPa or less.
  • the slit gap D 31 of the slit 58 through which the high refractive index layer coating liquid L 1 passes is changed in the range of 0.04 to 0.3 mm, and the slit of the slit 58 through which the low refractive index layer coating liquid L 2 passes.
  • gap D 32 was changed in the range of 0.15 ⁇ 0.5 mm.
  • the thickness D 4 of the pocket portion of the bars, 12.5 mm, the high-refractive index layer coating solution viscosity mu 1 and the low refractive index layer coating solution viscosity mu 2 was set to 10 mPa ⁇ s and 100 mPa ⁇ s.
  • the slit gaps D 31 and D 32 are 0.05 mm or more and 0.4 mm or less and the slit gap D 32 is larger than the slit gap D 31 , the film thickness variation rate A uniform coating film having (V) of 3.0% or less could be obtained.
  • the slit gap D 32 is, if more than five times the slit gap D 31, the pressure loss is too small, there is a possibility that the low refractive index layer coating solution L 2 is not uniformly flow out across the coating width. Therefore, the slit gap D 32 is preferably not more than 5 times the slit gap D 31.
  • the slit gap D 31 of the slit 58 the high refractive index layer coating solution L 1 passes is 0.05 mm
  • the film thickness variation rate (V) is 3.0% or less but exceeds 1.0%. This is because when the slit gap D 31 is 0.05 mm, is because it was difficult to manufacture a uniform slit in the coating width direction.
  • the slit gap D 32 of the slit 58 having a low refractive index layer coating solution L 2 passes is 0.4 mm
  • the slit gap D 31 of the slit 58 that passes through the high-refractive index layer coating solution L 1 is 0.05 to 0
  • the film thickness variation rate (V) is 3.0% or less, but exceeds 1.0%. This is because the slit gap D 32 is too narrow, the pressure loss generated when the low refractive index layer coating solution L 2 passes becomes excessively small, is because the coating solution is no longer uniformly flows out across the coating width .
  • the thickness of the pocket portion of the bar is 15 mm or less, the bar can be thinned, and even if the number of installed bars (number of coating layers) is increased, the coating solution It is suppressed that the slide surface comprised by the end surface of the bar
  • the pressure difference between the internal pressure of the concave portion of the pocket portion of the bar supplied with the second coating liquid and the internal pressure of the concave portion of the pocket portion of the bar supplied with the first coating liquid is 0.1 MPa. It is set to be as follows.
  • the electromagnetic wave shielding film can be applied to a far-infrared reflective film or an ultraviolet reflective film.
  • it is designed to reflect visible light or ultraviolet light instead of near-infrared light by adjusting the optical film thickness of the high refractive index layer and the low refractive index layer that are alternately stacked.
  • the structure in which the high refractive index layer and the low refractive index layer are alternately laminated is, for example, on the other surface of the film substrate after the simultaneous multilayer coating is performed on one surface of the film substrate and dried. It is also possible to arrange on both surfaces of the electromagnetic wave shielding film by performing simultaneous multilayer coating and drying.
  • a high refractive index layer is arranged on the lowermost layer and the uppermost layer of a structure in which a high refractive index layer and a low refractive index layer are alternately stacked, and the number of high refractive index layers to be installed is larger than that of the low refractive index layer. Is also possible. It is also possible to make the number of low refractive index layers and high refractive index layers the same.
  • a layer having another function between the film base and the coating layer or on the surface of the coating layer It is possible to arrange a layer having another function between the film base and the coating layer or on the surface of the coating layer. For example, it is possible to dispose a gas barrier layer or an easy-adhesion layer between the film substrate and the coating layer, or to dispose a hard coat layer or an abrasion-resistant layer on the surface of the coating layer.
  • 10 coating device 20 transport system, 22 film substrate, 24 Backroll, 30 Die coater, 32 laminates, 40 bars, 42 Front bar, 44 middle bar, 46 Backbar, 50 proximal end, 51 end face, 52 through holes, 53 pocket part 54 recess, 56 tip, 57 end face, 58 slits, 60 side wall, 70 coating solution supply system, 72 preparation kettle, 73 Piping system, 74 pumps, 76 Preparation kettle, 77 Piping system, 78 pump, 81,82 pressure sensor, D 1 , D 2 , D 3 , D 31 , D 32 , D 4 thickness, F coating direction, L, L 1 , L 2 coating solution, W coating width direction, ⁇ 1, ⁇ 2 Viscosity.

Abstract

[Problem] To provide a method for manufacturing an electromagnetic-wave-shielding film allowing good simultaneous layered application even when the number of layers is increased. [Solution] A method for manufacturing an electromagnetic-wave-shielding film having a structure in which high-refractive-index layers and low-refractive-index layers are alternatingly layered, wherein the method has a coating step in which a coating layer of a first coating liquid (L1) that constitutes a high-refractive-index layer and a coating layer of a second coating liquid (L2) that constitutes a low-refractive-index layer are layered in alternating fashion using a slide-type die coater having a plurality of layered bars (40), so that a film substrate is simultaneously coated with the layers. The bars (40) have: a tip section (56) that forms a gap (58) with adjacent other bars (40); a base section (50) that contacts other bars (4); and a pocket section (53) positioned between the tip section (56) and the base section (50), and having a recessed section (54) that is a coating-fluid reservoir section. The thickness (D4) of the pocket section (53) is no more than 15 mm, and during the coating step, the difference in pressure (ΔP) between the inner pressure (P2) of the recessed section (54) of the pocket section (53) of the bar (40) to which the second coating fluid (L(2) is supplied and the inner pressure (P1) of the recessed section (54) of the pocket section (53) of the bar (40) to which the first coating fluid (L(1) is supplied is set so as to be no greater than 0.1 MPa.

Description

電磁波遮蔽フィルムの製造方法Method for producing electromagnetic shielding film
　本発明は、電磁波遮蔽フィルムの製造方法に関する。 The present invention relates to a method for producing an electromagnetic wave shielding film.
　近年、省エネルギー対策への関心が高まり、建物や車両の窓ガラスに貼って、太陽光に含まれる熱線の透過を遮断して冷房設備にかかる負荷を減らすため、近赤外光を反射する機能を有する電磁波遮蔽フィルムの開発が盛んに行われている。 In recent years, interest in energy-saving measures has increased, and it has a function to reflect near-infrared light in order to reduce the load on cooling equipment by blocking the transmission of heat rays contained in sunlight by pasting it on the window glass of buildings and vehicles. Development of an electromagnetic shielding film having a large amount has been carried out.
　電磁波遮蔽フィルムは、高屈折率層と低屈折率層とを交互に積層されて構成されている。一般的に、高屈折率層および低屈折率層の層数が多いほど電磁波の反射率が高くなり、遮蔽効果が高くなることが知られているが、従来技術は、塗布によって１層ずつ逐次形成しており、生産性に問題を有している（例えば、特許文献１および２参照。）。そこで、生産性を向上させるために、一括して重層塗布（同時重層塗布）が可能なスライド式ダイコーターの適用が提案されている。 The electromagnetic wave shielding film is configured by alternately laminating high refractive index layers and low refractive index layers. Generally, it is known that as the number of high refractive index layers and low refractive index layers increases, the reflectivity of electromagnetic waves increases and the shielding effect increases. Therefore, there is a problem in productivity (for example, see Patent Documents 1 and 2). Therefore, in order to improve productivity, application of a slide type die coater capable of performing multilayer coating (simultaneous multilayer coating) at once has been proposed.
特開平８－１１０４０１号公報JP-A-8-110401 特開２００４－１２３７６６号公報JP 2004-123766 A
　しかし、スライド式ダイコーターを構成するバーの設置数（塗布層数）は、製造される電磁波遮蔽フィルムの層数（高屈折率層および低屈折率層の層数）に対応している。したがって、製造される電磁波遮蔽フィルムの層数を増加させるため、塗布層数を増やす場合、バーの設置数が増加し、塗布液が流下するバーの端面により構成されるスライド面が長くなる。これにより、塗布液の流れに乱れが生じ易くなり、均一な塗布が困難となり、また、塗布液の混ざりを生じて、電磁波遮蔽フィルムに悪影響、例えば、膜厚の不均一（変動）や性能の低下を招く虞があった。 However, the number of bars (number of coating layers) constituting the slide type die coater corresponds to the number of layers of the electromagnetic wave shielding film to be manufactured (number of high refractive index layers and low refractive index layers). Therefore, when increasing the number of coating layers in order to increase the number of layers of the electromagnetic shielding film to be manufactured, the number of bars installed increases, and the slide surface constituted by the end surfaces of the bars through which the coating liquid flows down becomes long. As a result, the flow of the coating liquid is likely to be disturbed, making uniform coating difficult, and mixing of the coating liquid may adversely affect the electromagnetic wave shielding film, for example, non-uniformity (fluctuation) in film thickness and performance. There was a risk of causing a drop.
　一方、塗布液の流れの乱れを防止するためには、スライド面を短くすることが有効であるが、そのためには、バーを薄くする必要がある。しかし、バーを薄くすると、低屈折率層塗布液粘度と高屈折率層塗布液粘度の差による影響、つまり、低屈折率層塗布液が隙間を通過する際に発生する圧力損失に基づく内部圧力と、高屈折率層塗布液が隙間を通過する際に発生する圧力損失に基づく内部圧力との圧力差の影響を受ける問題が生じる。 On the other hand, in order to prevent the disturbance of the flow of the coating liquid, it is effective to shorten the slide surface, but in order to do so, it is necessary to make the bar thinner. However, when the bar is thinned, the internal pressure based on the effect of the difference between the low refractive index layer coating liquid viscosity and the high refractive index layer coating liquid viscosity, that is, the pressure loss generated when the low refractive index layer coating liquid passes through the gap. And the problem of being affected by the pressure difference from the internal pressure based on the pressure loss generated when the high refractive index layer coating solution passes through the gap.
　例えば、圧力の高い方（粘度が大きい低屈折率層塗布液が通過する側）から低い方（粘度が小さい高屈折率層塗布液が通過する側）へと、バーが加圧されて変形し、塗布幅方向の隙間の均一性が悪化することで、塗布膜厚が不均一となり、製造される電磁波遮蔽フィルムの光学特性の均一性が低下し、例えば、色ムラが発生する問題が生じる。 For example, the bar is pressurized and deformed from the higher pressure (the side through which the low refractive index layer coating solution having a higher viscosity passes) to the lower side (the side through which the high refractive index layer coating solution having a lower viscosity passes). Since the uniformity of the gap in the coating width direction is deteriorated, the coating film thickness becomes non-uniform, the uniformity of the optical characteristics of the electromagnetic wave shielding film to be manufactured is lowered, and, for example, the problem of color unevenness occurs.
　本発明は、上記従来技術に伴う課題を解決するためになされたものであり、層数を増しても同時重層塗布を良好に実施することができる電磁波遮蔽フィルムの製造方法を提供することを目的とする。 The present invention has been made in order to solve the problems associated with the above-described conventional technology, and an object thereof is to provide a method for producing an electromagnetic wave shielding film capable of satisfactorily performing simultaneous multilayer coating even when the number of layers is increased. And
　本発明の上記目的は、下記の手段によって達成される。 The above object of the present invention is achieved by the following means.
　（１）高屈折率層と低屈折率層とが交互に積層した構造を有する電磁波遮蔽フィルムの製造方法において、
　複数の積層されたバーを有するスライド式ダイコーターを用いて、前記高屈折率層を構成することとなる第１塗布液の塗布層と、前記低屈折率層を構成することとなる第２塗布液の塗布層とを交互に積層させて、フィルム基材に同時重層塗布する塗布工程を、有しており、
　前記バーは、隣接する別のバーとの間に隙間を形成する先端部と、前記別のバーと当接する基端部と、前記先端部と前記基端部との間に位置し、塗布液溜まり部である凹部を有するポケット部と、を有し、
　前記ポケット部の厚みは、１５ｍｍ以下であり、
　前記塗布工程において、前記第２塗布液が供給されるバーのポケット部の凹部の内圧と、前記第１塗布液が供給されるバーのポケット部の凹部の内圧との圧力差は、０．１ＭＰａ以下になるように設定されている電磁波遮蔽フィルムの製造方法。 (1) In the method for producing an electromagnetic wave shielding film having a structure in which high refractive index layers and low refractive index layers are alternately laminated,
Using a slide type die coater having a plurality of stacked bars, the first coating liquid coating layer that constitutes the high refractive index layer and the second coating that constitutes the low refractive index layer. It has an application process of alternately laminating the liquid application layers and simultaneously applying multiple layers on the film substrate,
The bar is located between a tip portion that forms a gap with another adjacent bar, a base end portion that contacts the other bar, and the tip portion and the base end portion. A pocket portion having a recess which is a reservoir portion,
The pocket portion has a thickness of 15 mm or less,
In the coating step, the pressure difference between the internal pressure of the concave portion of the pocket portion of the bar supplied with the second coating liquid and the internal pressure of the concave portion of the pocket portion of the bar supplied with the first coating liquid is 0.1 MPa. The manufacturing method of the electromagnetic wave shielding film set so that it may become below.
　（２）前記第１塗布液の粘度μ１［ｍＰａ・ｓ］および前記第２塗布液の粘度μ２［ｍＰａ・ｓ］は、関係式（μ２≦４×μ１＋１００）を満たしている上記（１）に記載の電磁波遮蔽フィルムの製造方法。 (2) The viscosity μ 1 [mPa · s] of the first coating liquid and the viscosity μ 2 [mPa · s] of the second coating liquid satisfy the relational expression (μ 2 ≦ 4 × μ1 + 100) ( The manufacturing method of the electromagnetic wave shielding film as described in 1).
　（３）前記第１塗布液が供給されるバーの先端部の隙間の厚みであるスリット間隙Ｄ３１［ｍｍ］および前記第２塗布液が供給されるバーの先端部の隙間の厚みであるスリット間隙Ｄ３２［ｍｍ］は、０．０５以上かつ０．４以下であり、かつ、
　前記スリット間隙Ｄ３２は、前記スリット間隙Ｄ３１より大きい上記（１）に記載の電磁波遮蔽フィルムの製造方法。 (3) Slit gap D 31 [mm] which is the thickness of the gap at the tip of the bar to which the first coating liquid is supplied and the slit which is the thickness of the gap at the tip of the bar to which the second coating liquid is supplied The gap D 32 [mm] is 0.05 or more and 0.4 or less, and
The slit gap D 32 is the manufacturing method of the electromagnetic wave shielding film according to the slit gap D 31 is greater than the above (1).
　（４）前記第１塗布液の粘度μ１［ｍＰａ・ｓ］は、３以上かつ３０以下であり、
　前記第２塗布液の粘度μ２［ｍＰａ・ｓ］は、５０以上かつ５００以下である上記（２）に記載の電磁波遮蔽フィルムの製造方法。 (4) The viscosity μ 1 [mPa · s] of the first coating solution is 3 or more and 30 or less,
Viscosity μ 2 [mPa · s] of the second coating liquid is the method for producing an electromagnetic wave shielding film according to (2), which is 50 or more and 500 or less.
　（５）電磁波遮蔽フィルムは、近赤外光を反射する機能を有する上記（１）～（４）のいずれか１項に記載の電磁波遮蔽フィルムの製造方法。 (5) The method for producing an electromagnetic wave shielding film according to any one of (1) to (4), wherein the electromagnetic wave shielding film has a function of reflecting near infrared light.
　本発明によれば、バーのポケット部の厚みが１５ｍｍ以下であり、バーを薄くすることが可能であり、バーの設置数（塗布層数）を増しても、塗布液が流下するバーの端面により構成されるスライド面が長くなることが抑制される。また、塗布工程において、第２塗布液が供給されるバーのポケット部の凹部の内圧と、第１塗布液が供給されるバーのポケット部の凹部の内圧との圧力差が、０．１ＭＰａ以下になるように設定されている。つまり、バーの最小肉厚部であり、圧力の影響を受けて変形し易いポケット部における圧力差が小さいため、バーの変形が抑制され、塗布幅方向の隙間の均一性が維持され、塗布幅方向の塗布膜厚が不均一になることが防がれるため、製造される電磁波遮蔽フィルムの光学特性の均一性は、良好である。したがって、層数を増しても同時重層塗布を良好に実施することができる電磁波遮蔽フィルムの製造方法を提供することが可能である。 According to the present invention, the thickness of the pocket portion of the bar is 15 mm or less, the bar can be thinned, and the end surface of the bar where the coating liquid flows down even when the number of installed bars (number of coating layers) is increased. It is suppressed that the slide surface comprised by becomes long. In the coating process, the pressure difference between the internal pressure of the concave portion of the pocket portion of the bar supplied with the second coating liquid and the internal pressure of the concave portion of the pocket portion of the bar supplied with the first coating liquid is 0.1 MPa or less. It is set to be. In other words, it is the minimum wall thickness of the bar, and since the pressure difference in the pocket that is easily deformed under the influence of pressure is small, the deformation of the bar is suppressed, and the uniformity of the gap in the coating width direction is maintained. Since the coating film thickness in the direction is prevented from becoming uneven, the uniformity of the optical properties of the manufactured electromagnetic wave shielding film is good. Therefore, it is possible to provide a method for producing an electromagnetic wave shielding film that can satisfactorily perform simultaneous multilayer coating even when the number of layers is increased.
　本発明のさらに他の目的、特徴および特質は、以後の説明および添付図面に例示される好ましい実施の形態を参照することによって、明らかになるであろう。 Further objects, features, and characteristics of the present invention will become apparent by referring to the preferred embodiments illustrated in the following description and the accompanying drawings.
本発明の実施の形態に係る電磁波遮蔽フィルムの製造方法を説明するためのフローチャートである。It is a flowchart for demonstrating the manufacturing method of the electromagnetic wave shielding film which concerns on embodiment of this invention. 図１に示される調製工程および塗布工程に適用される塗布装置を説明するための概略図である。It is the schematic for demonstrating the coating device applied to the preparation process and application | coating process which are shown by FIG. 図２に示されるダイコーターの側方壁部を説明するための平面図である。It is a top view for demonstrating the side wall part of the die-coater shown by FIG. 図２に示されるダイコーターのバーを説明するための平面図である。It is a top view for demonstrating the bar | burr of the die-coater shown by FIG. 図４の線Ｖ－Ｖに関する断面図である。FIG. 5 is a cross-sectional view taken along line VV in FIG. 4. 本発明の実施の形態に係る塗布工程を説明するための断面図である。It is sectional drawing for demonstrating the application | coating process which concerns on embodiment of this invention. 塗布工程における塗布条件を説明するための断面図である。It is sectional drawing for demonstrating the application | coating conditions in an application | coating process. 比較例を説明するための断面図である。It is sectional drawing for demonstrating a comparative example. 電磁波遮蔽フィルムの膜厚変動率に対するバーのポケット部の厚みおよび圧力差の影響を説明するための試験結果を示しているテーブルである。It is a table which shows the test result for demonstrating the influence of the thickness of the pocket part of a bar, and the pressure difference with respect to the film thickness fluctuation rate of an electromagnetic wave shielding film. 電磁波遮蔽フィルムの膜厚変動率および圧力差に対する塗布液粘度の影響を説明するための試験結果を示しているテーブルである。It is a table | surface which shows the test result for demonstrating the influence of the coating liquid viscosity with respect to the film thickness fluctuation rate and pressure difference of an electromagnetic wave shielding film. 電磁波遮蔽フィルムの膜厚変動率に対するスリット間隔の影響を説明するための試験結果を示しているテーブルである。It is a table which shows the test result for demonstrating the influence of the slit space | interval with respect to the film thickness fluctuation rate of an electromagnetic wave shielding film.
　以下、本発明の実施の形態が、図面を参照しつつ説明される。なお、図面の寸法比率は、説明の都合上誇張されており、実際の比率とは異なる場合がある。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the dimension ratio of drawing is exaggerated on account of description, and may differ from an actual ratio.
　図１は、本発明の実施の形態に係る電磁波遮蔽フィルムの製造方法を説明するためのフローチャートである。 FIG. 1 is a flowchart for explaining a method of manufacturing an electromagnetic wave shielding film according to an embodiment of the present invention.
　本発明の実施の形態に係る電磁波遮蔽フィルムは、高屈折率層と低屈折率層とを交互に複数積層して構成され、可視光領域（波長３８０～７８０ｎｍ）で透過率が高く、近赤外光領域（７８０～２５００ｎｍ）で反射率が高い光学特性を有する。電磁波遮蔽フィルムの用途は、近赤外光反射フィルムであり、建物の屋外の窓、自動車窓、農業用ビニールハウス等に配置され、熱線反射効果を付与するために使用される。 An electromagnetic wave shielding film according to an embodiment of the present invention is formed by alternately laminating a plurality of high refractive index layers and low refractive index layers, has high transmittance in the visible light region (wavelength 380 to 780 nm), and is near-red. It has optical characteristics with high reflectivity in the outside light region (780-2500 nm). The electromagnetic wave shielding film is used as a near-infrared light reflecting film, and is disposed in an outdoor window of a building, an automobile window, an agricultural greenhouse, and the like, and is used for imparting a heat ray reflecting effect.
　「高屈折率層」および「低屈折率層」は、隣接した２層の屈折率差を比較した場合に、屈折率が高い方を高屈折率層、低い方を低屈折率層とすることを意味する。特定波長領域の反射率は、隣接する２層の屈折率差と層数で決まり、屈折率の差が大きいほど、少ない層数で高い反射率を得られる。 "High refractive index layer" and "low refractive index layer", when comparing the refractive index difference between two adjacent layers, the higher refractive index layer is the high refractive index layer, the lower one is the low refractive index layer Means. The reflectance in the specific wavelength region is determined by the refractive index difference between two adjacent layers and the number of layers. The larger the refractive index difference, the higher the reflectance can be obtained with a smaller number of layers.
　本発明の実施の形態に係る電磁波遮蔽フィルムの製造方法は、図１に示されるように、調製工程、塗布工程および乾燥工程を有する。 The method for manufacturing an electromagnetic wave shielding film according to the embodiment of the present invention includes a preparation step, a coating step, and a drying step, as shown in FIG.
　調製工程においては、例えば、金属酸化物粒子、樹脂バインダー、硬化剤、添加剤、溶媒等を混合することによって、高屈折率層塗布液および低屈折率層塗布液が調製される。 In the preparation step, for example, a high refractive index layer coating solution and a low refractive index layer coating solution are prepared by mixing metal oxide particles, a resin binder, a curing agent, an additive, a solvent, and the like.
　塗布工程においては、フィルム基材に対し、電磁波遮蔽フィルムの各層に対応する高屈折率層塗布液および低屈折率層塗布液が、一括して重層塗布（同時重層塗布）される。 In the coating step, the high refractive index layer coating liquid and the low refractive index layer coating liquid corresponding to each layer of the electromagnetic wave shielding film are collectively coated (simultaneous multilayer coating) on the film substrate.
　フィルム基材は、ポリオレフィンフィルム、ポリエステルフィルム、ポリ塩化ビニルフィルム、３酢酸セルロースフィルム等の種々の樹脂フィルムを適用すること可能である。ポリオレフィンは、例えば、ポリエチレン、ポリプロピレである。ポリエステルは、例えば、ポリエチレンテレフタレート、ポリエチレンナフタレートである。 As the film substrate, various resin films such as polyolefin film, polyester film, polyvinyl chloride film, and cellulose acetate film can be applied. Polyolefin is, for example, polyethylene or polypropylene. Examples of the polyester include polyethylene terephthalate and polyethylene naphthalate.
　乾燥工程においては、高屈折率層塗布液および低屈折率層塗布液が重層塗布されたフィルム基材を乾燥（熱硬化）することにより、電磁波遮蔽フィルムが製造される。乾燥条件は、高屈折率層塗布液および低屈折率層塗布液に含まれている揮発性成分の蒸発温度、硬化剤の硬化温度、フィルム基材の耐熱温度等を考慮して適宜設定される。乾燥された電磁波遮蔽フィルムは、その後、必要に応じて適当なサイズに裁断される。 In the drying step, an electromagnetic wave shielding film is produced by drying (thermosetting) the film substrate on which the high refractive index layer coating solution and the low refractive index layer coating solution are applied in multiple layers. The drying conditions are appropriately set in consideration of the evaporation temperature of the volatile components contained in the high refractive index layer coating solution and the low refractive index layer coating solution, the curing temperature of the curing agent, the heat resistant temperature of the film substrate, and the like. . The dried electromagnetic shielding film is then cut into an appropriate size as necessary.
　後述するように、塗布工程は、高屈折率層塗布液および低屈折率層塗布液の塗布層数（電磁波遮蔽フィルムの層数）を増しても同時重層塗布を良好に実施することが可能であり、１層当りの塗布厚を小さくすることによって、乾燥工程における乾燥負荷を低減することが可能である。 As will be described later, in the coating process, even when the number of coating layers of the high refractive index layer coating solution and the low refractive index layer coating solution (the number of layers of the electromagnetic wave shielding film) is increased, simultaneous multilayer coating can be carried out satisfactorily. It is possible to reduce the drying load in the drying process by reducing the coating thickness per layer.
　なお、高屈折率層塗布液の金属酸化物粒子は、例えば、二酸化チタン、酸化ジルコニウム、酸化亜鉛、アルミナ、コロイダルアルミナ、チタン酸鉛、鉛丹、黄鉛、亜鉛黄、酸化クロム、酸化第二鉄、鉄黒、酸化銅、酸化マグネシウム、水酸化マグネシウム、チタン酸ストロンチウム、酸化イットリウム、酸化ニオブ、酸化ユーロピウム、酸化ランタン、ジルコン、酸化スズである。高屈折率層塗布液の金属酸化物粒子は、透明で高い屈折率を得るためには、酸化チタン微粒子、酸化ジルコニア微粒子を含有することが好ましい。金属酸化物粒子の濃度は、例えば、１～５０質量％である。 The metal oxide particles of the high refractive index layer coating liquid are, for example, titanium dioxide, zirconium oxide, zinc oxide, alumina, colloidal alumina, lead titanate, red lead, yellow lead, zinc yellow, chromium oxide, second oxide. They are iron, iron black, copper oxide, magnesium oxide, magnesium hydroxide, strontium titanate, yttrium oxide, niobium oxide, europium oxide, lanthanum oxide, zircon and tin oxide. In order to obtain a transparent and high refractive index, the metal oxide particles of the high refractive index layer coating solution preferably contain titanium oxide fine particles and zirconia oxide fine particles. The concentration of the metal oxide particles is, for example, 1 to 50% by mass.
　低屈折率層塗布液の金属酸化物粒子は、例えば、二酸化ケイ素、コロイダルシリカである。金属酸化物粒子の濃度は、例えば、１～５０質量％である。 The metal oxide particles of the low refractive index layer coating solution are, for example, silicon dioxide and colloidal silica. The concentration of the metal oxide particles is, for example, 1 to 50% by mass.
　樹脂バインダーは、例えば、ポリビニルアルコール、ゼラチン、水溶性セルロース誘導体、増粘多糖類、反応性官能基を有するポリマー類である。高屈折率層塗布液の樹脂バインダーの濃度は、例えば、０．５～１０質量％である。低屈折率層塗布液中の樹脂バインダーの濃度は、１～１０質量％である。 Resin binders are, for example, polyvinyl alcohol, gelatin, water-soluble cellulose derivatives, thickening polysaccharides, and polymers having reactive functional groups. The concentration of the resin binder in the high refractive index layer coating solution is, for example, 0.5 to 10% by mass. The concentration of the resin binder in the low refractive index layer coating solution is 1 to 10% by mass.
　硬化剤は、樹脂バインダーと硬化反応を起こすものであれば特に限定されない。樹脂バインダーとしてポリビニルアルコールが選択されている場合、硬化剤は、例えば、ホウ酸およびその塩である。 The curing agent is not particularly limited as long as it causes a curing reaction with the resin binder. When polyvinyl alcohol is selected as the resin binder, the curing agent is, for example, boric acid and its salt.
　添加剤は、例えば、紫外線吸収剤、退色防止剤、界面活性剤、蛍光増白剤、ｐＨ調整剤、消泡剤、潤滑剤、防腐剤、帯電防止剤である。 Additives are, for example, ultraviolet absorbers, fading inhibitors, surfactants, fluorescent brighteners, pH adjusters, antifoaming agents, lubricants, preservatives, and antistatic agents.
　溶媒は、例えば、水、有機溶媒、あるいはこれらの混合溶液である。有機溶媒は、メタノール、エタノール、酢酸エチル等である。 The solvent is, for example, water, an organic solvent, or a mixed solution thereof. The organic solvent is methanol, ethanol, ethyl acetate or the like.
　次に、調製工程および塗布工程に適用される塗布装置が説明される。 Next, a coating apparatus applied to the preparation process and the coating process will be described.
　図２は、図１に示される調製工程および塗布工程に適用される塗布装置を説明するための概略図、図３は、図２に示されるダイコーターの側方壁部を説明するための平面図、図４は、図２に示されるダイコーターのバーを説明するための平面図、図５は、図４の線Ｖ－Ｖに関する断面図である。 2 is a schematic view for explaining a coating apparatus applied to the preparation step and the coating step shown in FIG. 1, and FIG. 3 is a plan view for explaining a side wall portion of the die coater shown in FIG. 4 is a plan view for explaining the bar of the die coater shown in FIG. 2, and FIG. 5 is a cross-sectional view taken along line VV in FIG.
　塗布装置１０は、図２に示されるように、搬送系２０、ダイコーター３０、塗布液供給系７０および圧力センサー８１，８２を有する。 As shown in FIG. 2, the coating apparatus 10 includes a transport system 20, a die coater 30, a coating liquid supply system 70, and pressure sensors 81 and 82.
　搬送系２０は、フィルム基材２２およびバックロール２４を有する。フィルム基材２２は、塗布液Ｌが塗布される帯状の支持体である。バックロール２４は、フィルム基材２２の内側に配置され、回転駆動されることによって、塗布方向（搬送方向）Ｆの上流側から下流側に向かって、フィルム基材２２を搬送するように構成されている。なお、フィルム基材２２は、塗布液Ｌが塗布される際、加熱手段（不図示）によって所定温度（例えば、３０℃以上）に昇温される。 The conveyance system 20 includes a film base material 22 and a back roll 24. The film substrate 22 is a belt-like support on which the coating liquid L is applied. The back roll 24 is arranged inside the film base 22 and is configured to transport the film base 22 from the upstream side to the downstream side in the application direction (transport direction) F by being driven to rotate. ing. In addition, when the coating liquid L is apply | coated, the film base material 22 is heated up to predetermined temperature (for example, 30 degreeC or more) by a heating means (not shown).
　ダイコーター３０は、スライド式であり、電磁波遮蔽フィルムの各層に対応する塗布層を一括して塗布（同時重層塗布）することが可能に構成されており、積層体３２および側方壁部６０を有する。積層体３２は、長方形状の複数のバー４０が順に重ねられて構成される。 The die coater 30 is a slide type, and is configured such that coating layers corresponding to the layers of the electromagnetic wave shielding film can be collectively applied (simultaneous multilayer coating). Have. The stacked body 32 is configured by stacking a plurality of rectangular bars 40 in order.
　バー４０は、例えば、ステンレススチールから構成され、フロントバー４２、複数の中間バー４４およびバックバー４６を含んでおり、これらは、略同一形状である。フロントバー４２は、積層体３２の最下層を占めているバーであり、フィルム基材２２の近傍に位置決めされる。バックバー４６は、積層体３２の最上層を占めているバーである。中間バー４４は、フロントバー４２とバックバー４６との間に位置する中間層を占めているバーである。側方壁部６０は、図３に示されるように、積層体３２の塗布幅方向Ｗの端面に配置されている。バー４０の構成材料は、ステンレススチールに限定されない。なお、塗布幅方向Ｗは、塗布方向（搬送方向）Ｆと直交している。 The bar 40 is made of, for example, stainless steel, and includes a front bar 42, a plurality of intermediate bars 44, and a back bar 46, which have substantially the same shape. The front bar 42 is a bar that occupies the lowermost layer of the laminate 32 and is positioned in the vicinity of the film substrate 22. The back bar 46 is a bar that occupies the uppermost layer of the stacked body 32. The intermediate bar 44 is a bar that occupies an intermediate layer located between the front bar 42 and the back bar 46. The side wall part 60 is arrange | positioned at the end surface of the application | coating width direction W of the laminated body 32, as FIG. 3 shows. The constituent material of the bar 40 is not limited to stainless steel. The application width direction W is orthogonal to the application direction (conveyance direction) F.
　バー４０は、図４および図５に示されるように、基端側から順に基端部５０、ポケット部５３および先端部５６を有する。 4 and 5, the bar 40 has a proximal end portion 50, a pocket portion 53, and a distal end portion 56 in order from the proximal end side.
　基端部５０は、塗布液供給系７０と連通している貫通孔５２を有する。貫通孔５２は、基端部５０の塗布幅方向Ｗ中央に位置し、基端部５０端面からポケット部５３に向かって延長している。 The base end portion 50 has a through hole 52 communicating with the coating liquid supply system 70. The through hole 52 is located in the center of the application width direction W of the base end portion 50 and extends from the end surface of the base end portion 50 toward the pocket portion 53.
　基端部５０の厚みＤ１は、先端部５６の厚みＤ２より大きく設定されている。したがって、バー４０が積層されると、基端部５０は、隣接する別のバーの基端部５０と当接する一方、先端部５６と、隣接する別のバーの先端部５６との間には、厚みＤ３（＝Ｄ１－Ｄ２）のスリット（隙間）５８が形成される。以下において、厚みＤ３は、スリット間隔Ｄ３で参照する。なお、符号５１は、基端部５０の端面を示している。 A thickness D 1 of the proximal end portion 50 is set to be larger than a thickness D 2 of the distal end portion 56. Therefore, when the bars 40 are stacked, the base end portion 50 comes into contact with the base end portion 50 of another adjacent bar, while the front end portion 56 and the front end portion 56 of another adjacent bar are in between. A slit (gap) 58 having a thickness D 3 (= D 1 −D 2 ) is formed. In the following, the thickness D 3 are referenced by the slit spacing D 3. Reference numeral 51 denotes an end face of the base end portion 50.
　スリット５８は、塗布液が通過する通路として機能する。スリット５８の先端から吐出された塗布液は、先端部５６の端面５７を流下するため、端面５７は、塗布液が流下するスライド面として機能する。 The slit 58 functions as a passage through which the coating liquid passes. Since the coating liquid discharged from the front end of the slit 58 flows down the end surface 57 of the front end portion 56, the end surface 57 functions as a slide surface on which the coating liquid flows down.
　ポケット部５３は、バー４０の塗布幅方向Ｗに延長して形成される凹部５４を有する。凹部５４は、スリット５８および貫通孔５２に連通している塗布液溜まり部である。凹部５４は、貫通孔５２（塗布液供給系７０）からの塗布液を塗布幅方向Ｗに均等に広げて、スリット５８に安定的に供給するために使用される。 The pocket portion 53 has a concave portion 54 formed to extend in the coating width direction W of the bar 40. The recess 54 is a coating liquid reservoir that communicates with the slit 58 and the through hole 52. The concave portion 54 is used to spread the coating liquid from the through-hole 52 (coating liquid supply system 70) evenly in the coating width direction W and stably supply it to the slit 58.
　ポケット部５３の厚みＤ４は、１５ｍｍ以下に設定されている。そのため、バー４０を薄くする（薄肉化および軽量化する）ことが可能であり、バー４０の設置数（塗布層数）を増しても、スライド面が長くなることが抑制される。また、ダイコーター３０の小型化、少スペース化、省エネルギー、装置コストの削減が可能となり、かつ、取り扱いも容易となり、作業性の向上および塗布故障の低減も期待できる。 The thickness D 4 of the pocket portion 53 is set to 15mm or less. Therefore, it is possible to make the bar 40 thinner (thinner and lighter), and even if the number of installed bars 40 (the number of coating layers) is increased, an increase in the sliding surface is suppressed. In addition, the die coater 30 can be reduced in size, space-saving, energy saving, equipment cost can be reduced, handling can be facilitated, workability can be improved, and coating failure can be expected.
　バー４０の積層位置に応じて、バー４０の貫通孔５２に、高屈折率層を構成することとなる第１塗布液である高屈折率層塗布液Ｌ１と、低屈折率層を構成することとなる第２塗布液である低屈折率層塗布液Ｌ２と、が交互に導入される。例えば、フロントバー４２の貫通孔５２には、低屈折率層塗布液Ｌ２が導入され、フロントバー４２に隣接する中間バー４４の貫通孔には、高屈折率層塗布液Ｌ１が導入され、当該中間バー４４に隣接する別の中間バー４４の貫通孔５２には、低屈折率層塗布液Ｌ２が導入される。したがって、スリット５８の設置数は、製造される電磁波遮蔽フィルムの層数に一致しており、製造される電磁波遮蔽フィルムの層数に応じて、中間バー４４の数が調整されることになる。なお、スライド面は、２層以上が積層されて流下する中間バー４４及びフロントバー４２の先端部５６の端面５７長さの合計であり、最上層をのぞく中間バー４４の厚みとフロントバー４２の厚みの合計と略一致する。 Depending on the stacking position of the bar 40, the through hole 52 of the bar 40, the high-refractive index layer coating solution L 1 which is a first coating liquid constitutes the high refractive index layer and the low refractive index layer and thus the second coating liquid and the low-refractive index layer coating solution L 2, but are alternately introduced. For example, the low refractive index layer coating liquid L 2 is introduced into the through hole 52 of the front bar 42, and the high refractive index layer coating liquid L 1 is introduced into the through hole of the intermediate bar 44 adjacent to the front bar 42. , the through hole 52 of another intermediate bar 44 adjacent to the intermediate bar 44, the low refractive index layer coating solution L 2 is introduced. Therefore, the number of slits 58 is equal to the number of layers of the manufactured electromagnetic shielding film, and the number of intermediate bars 44 is adjusted according to the number of layers of the manufactured electromagnetic shielding film. The sliding surface is the sum of the length of the end surface 57 of the front end portion 56 of the intermediate bar 44 and the front bar 42 in which two or more layers are stacked, and the thickness of the intermediate bar 44 excluding the uppermost layer and the front bar 42 It almost coincides with the total thickness.
　塗布液供給系７０は、図２に示されるように、低屈折率層塗布液Ｌ２および高屈折率層塗布液Ｌ１をダイコーター３０に供給するために使用され、調製釜７２，７６、配管系７３，７７およびポンプ７４，７８を有する。 Coating liquid supply system 70, as shown in FIG. 2, is used to provide a low refractive index layer coating solution L 2 and the high-refractive index layer coating solution L 1 die coater 30, the preparation kettle 72 and 76, It has piping systems 73 and 77 and pumps 74 and 78.
　調製釜７２は、低屈折率層塗布液Ｌ２を調製し、所定温度（例えば、３０℃以上）で保持するために使用される容器である。配管系７３は、調製釜７２と、低屈折率層塗布液用のバー４０の基端部５０の貫通孔５２と、を連結している。ポンプ７４は、配管系７３を経由して、調製された低屈折率層塗布液Ｌ２を圧送するために使用される。 Preparation kettle 72, a low refractive index layer coating solution L 2 is prepared, a predetermined temperature (e.g., 30 ° C. or higher) is a vessel used to hold in. The piping system 73 connects the preparation kettle 72 and the through hole 52 of the base end portion 50 of the bar 40 for the low refractive index layer coating solution. The pump 74 is used for pumping the prepared low refractive index layer coating liquid L 2 through the piping system 73.
　調製釜７６は、高屈折率層塗布液Ｌ１を調製し、所定温度（例えば、３０℃以上）で保持するために使用される容器である。配管系７７は、調製釜７６と、高屈折率層塗布液用のバー４０の基端部５０の貫通孔５２と、を連結している。ポンプ７８は、配管系７７を経由して、調製された高屈折率層塗布液Ｌ１を圧送するために使用される。ポンプ７４，７８は、例えば、ギアポンプやチューブポンプである。 Preparation kettle 76, the high refractive index layer coating solution L 1 was prepared, a predetermined temperature (e.g., 30 ° C. or higher) is a vessel used to hold in. The piping system 77 connects the preparation pot 76 and the through hole 52 of the base end portion 50 of the bar 40 for the high refractive index layer coating solution. Pump 78, via the piping system 77 is used which is prepared a high refractive index layer coating solution L 1 for pumping. The pumps 74 and 78 are, for example, gear pumps or tube pumps.
　圧力センサー８１，８２は、ダイコーター３０の近傍の配管系７３，７７に配置され、圧力差を検出するために使用される。検出される圧力差は、低屈折率層塗布液Ｌ２が供給されるバー４０のポケット部５３の凹部５４の内圧と、高屈折率層塗布液Ｌ１が供給されるバー４０のポケット部５３の凹部５４の内圧と、の圧力差であり、塗布工程において０．１ＭＰａ以下となるように設定されている。 The pressure sensors 81 and 82 are disposed in the piping systems 73 and 77 in the vicinity of the die coater 30 and are used for detecting a pressure difference. Pressure differential is detected, and the internal pressure of the recess 54 of the pocket portion 53 of the bar 40 having a low refractive index layer coating solution L 2 is supplied, the pocket section 53 of the bar 40 to the high refractive index layer coating solution L 1 is supplied Is set to be 0.1 MPa or less in the coating step.
　圧力センサー８１，８２は、例えば、ポケット部５３の凹部５４の内面に配置したり、ポケット部５３の凹部５４と当接する側方壁部６０の内面に配置したりすることも可能である。圧力差は、差圧計によって直接検出することも可能である。 The pressure sensors 81 and 82 can be disposed on the inner surface of the concave portion 54 of the pocket portion 53 or on the inner surface of the side wall portion 60 in contact with the concave portion 54 of the pocket portion 53, for example. The pressure difference can also be detected directly by a differential pressure gauge.
　次に、調製工程および塗布工程が詳述される。 Next, the preparation process and the application process will be described in detail.
　図６は、本発明の実施の形態に係る塗布工程を説明するための断面図、図７は、塗布工程における塗布条件を説明するための断面図、図８は、比較例を説明するための断面図である。 6 is a cross-sectional view for explaining a coating process according to an embodiment of the present invention, FIG. 7 is a cross-sectional view for explaining a coating condition in the coating process, and FIG. 8 is for explaining a comparative example. It is sectional drawing.
　調製工程においては、低屈折率層用の金属酸化物粒子、樹脂バインダー、硬化剤、添加剤、溶媒等を、調製釜７２に投入後、混合することによって、低屈折率層塗布液Ｌ２が調製される一方、高屈折率層用の金属酸化物粒子、樹脂バインダー、硬化剤、添加剤、溶媒等を、調製釜７６に投入後、混合することによって、高屈折率層塗布液Ｌ１が調製される。そして、調製された低屈折率層塗布液Ｌ２および高屈折率層塗布液Ｌ１は、所定温度（例えば、３０℃以上）で保持される。 In the preparation process, the metal oxide particles for low refractive index layer, the resin binder, a curing agent, additives, solvents and the like, after turning the preparation kettle 72, by mixing, the low refractive index layer coating solution L 2 while being prepared, the metal oxide particles for high refractive index layer, the resin binder, a curing agent, additives, solvents and the like, after turning the preparation kettle 76, by mixing, the high refractive index layer coating solution L 1 Prepared. Then, the low refractive index layer coating solution L 2 and the high-refractive index layer coating solution L 1 which is prepared is held at a predetermined temperature (e.g., 30 ° C. or higher).
　塗布工程において、調製された低屈折率層塗布液Ｌ２および高屈折率層塗布液Ｌ１は、ポンプ７４，７８によって圧送され、配管系７３，７７を経由して、低屈折率層塗布液用のバー４０の基端部５０の貫通孔５２および高屈折率層塗布液用のバー４０の基端部５０の貫通孔５２に供給される。 In the coating step, the prepared low refractive index layer coating liquid L 2 and high refractive index layer coating liquid L 1 are pumped by pumps 74 and 78, and are connected to the low refractive index layer coating liquid via the piping systems 73 and 77. To the through hole 52 of the base end portion 50 of the bar 40 for use and the through hole 52 of the base end portion 50 of the bar 40 for the high refractive index layer coating solution.
　これにより、図６に示されるように、バー４０の積層位置に応じて、バー４０の貫通孔５２に、高屈折率層塗布液Ｌ１と低屈折率層塗布液Ｌ２とが交互に導入される。例えば、フロントバー４２の貫通孔５２には、低屈折率層塗布液Ｌ２が導入され、フロントバー４２に隣接する中間バー４４の貫通孔には、高屈折率層塗布液Ｌ１が導入され、当該中間バー４４に隣接する別の中間バー４４の貫通孔５２には、低屈折率層塗布液Ｌ２が導入される。 Thereby, as shown in FIG. 6, the high refractive index layer coating liquid L 1 and the low refractive index layer coating liquid L 2 are alternately introduced into the through holes 52 of the bar 40 according to the stacking position of the bars 40. Is done. For example, the low refractive index layer coating liquid L 2 is introduced into the through hole 52 of the front bar 42, and the high refractive index layer coating liquid L 1 is introduced into the through hole of the intermediate bar 44 adjacent to the front bar 42. , the through hole 52 of another intermediate bar 44 adjacent to the intermediate bar 44, the low refractive index layer coating solution L 2 is introduced.
　塗布液は、ポケット部５３の凹部５４において塗布幅方向Ｗに均等に広げられて、スリット５８に導入される。スリット５８を通過した塗布液は、図６に示されるように、バー４０の先端部５６の端面５７を流下し、下方に位置する別のバー４０の先端部５６の端面５７を流下する塗布液と、順次重なる。そして、流下する塗布液は、フロントバー４２のスリット５８を通過した塗布液と重なった時点において、製造される電磁波遮蔽フィルムの層数に一致する層から構成されることになる。 The coating solution is spread evenly in the coating width direction W in the concave portion 54 of the pocket portion 53 and introduced into the slit 58. As shown in FIG. 6, the coating solution that has passed through the slit 58 flows down the end surface 57 of the tip portion 56 of the bar 40 and flows down the end surface 57 of the tip portion 56 of another bar 40 positioned below. And overlap one after another. And the coating liquid which flows down is comprised from the layer corresponding to the number of layers of the electromagnetic wave shielding film manufactured at the time of overlapping with the coating liquid which passed the slit 58 of the front bar 42.
　そして、塗布液Ｌは、最下層のバー４０であるフロントバー４２から離間して、所定温度（例えば、３０℃以上）に昇温されたフィルム基材２２に流下する（塗布される）。 Then, the coating liquid L flows away (applied) to the film base material 22 that has been heated to a predetermined temperature (for example, 30 ° C. or more) apart from the front bar 42 that is the lowermost bar 40.
　この際、バー４０のポケット部５３の厚みＤ４は、１５ｍｍ以下に設定され、バー４０が薄くなっており、バー４０の設置数（塗布層数）を増しても、スライド面が長くなることが抑制されている。 In this case, the thickness D 4 of the pocket portion 53 of the bar 40 is set to 15mm or less, a bar 40 which is thinner, even increasing installation speed of the bar 40 (the number of coating layer), the slide surface is long Is suppressed.
　また、塗布液Ｌがバー４０のスリット５８を通過する際に、圧力損失（スリット抵抗）を生じ、これにより、ダイコーター３０の内部に圧力（内圧）が発生する。内圧は、塗布液Ｌの粘度によって影響を受ける。 Further, when the coating liquid L passes through the slit 58 of the bar 40, a pressure loss (slit resistance) is generated, and thereby pressure (internal pressure) is generated inside the die coater 30. The internal pressure is affected by the viscosity of the coating liquid L.
　高屈折率層塗布液Ｌ１の粘度μ１は、３ｍＰａ・ｓ以上かつ３０ｍＰａ・ｓ以下である。低屈折率層塗布液Ｌ２の粘度μ２は、５０ｍＰａ・ｓ以上かつ５００ｍＰａ・ｓ以下であり、高屈折率層塗布液Ｌ１の粘度μ１よりも１桁以上大きい。したがって、高屈折率層塗布液Ｌ１が供給される凹部５４の内圧Ｐ１は、低屈折率層塗布液Ｌ２が供給される凹部５４の内圧Ｐ２より小さくなり、隣接する（隣り合う）バー４０間で内圧の圧力差が生じる。 The viscosity μ 1 of the high refractive index layer coating liquid L 1 is 3 mPa · s or more and 30 mPa · s or less. The viscosity μ 2 of the low refractive index layer coating liquid L 2 is 50 mPa · s or more and 500 mPa · s or less, which is one digit or more larger than the viscosity μ 1 of the high refractive index layer coating liquid L 1 . Therefore, the internal pressure P 1 of the concave portion 54 to which the high refractive index layer coating liquid L 1 is supplied is smaller than the internal pressure P 2 of the concave portion 54 to which the low refractive index layer coating liquid L 2 is supplied, and is adjacent (adjacent). An internal pressure difference occurs between the bars 40.
　これにより、図８の比較例に示されるように、高圧の方（低屈折率層塗布液Ｌ２が供給される凹部５４）から低圧の方（高屈折率層塗布液Ｌ１が供給される凹部５４）へと、その間に位置するバー４０が押されて変形する。その結果、低屈折率層塗布液Ｌ２が通過するスリット５８のスリット間隙Ｄ３２は拡大し、高屈折率層塗布液Ｌ１が通過するスリット５８のスリット間隙Ｄ３１は縮小する。つまり、塗布幅方向のスリット間隙の分布が悪化することにより、スリット５８から流出する塗布液Ｌの塗布幅方向の均一性も低下し、最終的には均一な塗布膜厚が得られなくなってしまう。 Thus, as shown in the comparative example of FIG. 8, towards the low pressure (high refractive index layer coating solution L 1 is supplied from the side of the high pressure (recess 54 having a low refractive index layer coating solution L 2 is supplied) To the recess 54), the bar 40 positioned therebetween is pushed and deformed. As a result, the slit gap D 32 of the slit 58 having a low refractive index layer coating solution L 2 passes is enlarged, the slit gap D 31 of the slit 58 the high refractive index layer coating solution L 1 passes is reduced. That is, when the distribution of the slit gap in the coating width direction is deteriorated, the uniformity in the coating width direction of the coating liquid L flowing out from the slit 58 is also lowered, and eventually a uniform coating film thickness cannot be obtained. .
　一方、本実施の形態に係る塗布工程においては、図７に示されるように、低屈折率層塗布液Ｌ２が供給されるバー４０のポケット部５３の凹部５４の内圧Ｐ２と、高屈折率層塗布液Ｌ１が供給されるバー４０のポケット部５３の凹部５４の内圧Ｐ１と、の圧力差ΔＰは、０．１ＭＰａ以下になるように設定されている。 On the other hand, in the coating process according to the present embodiment, as shown in FIG. 7, the internal pressure P 2 of the concave portion 54 of the pocket portion 53 of the bar 40 to which the low refractive index layer coating liquid L 2 is supplied, and the high refraction. The pressure difference ΔP between the internal pressure P 1 of the recess 54 of the pocket portion 53 of the bar 40 to which the rate layer coating liquid L 1 is supplied is set to be 0.1 MPa or less.
　したがって、バー４０の最小肉厚部であり、圧力の影響を受けて変形し易いポケット部５３に関する圧力差ΔＰが小さいため、バー４０の変形が抑制され、塗布幅方向の隙間の均一性が維持され、塗布幅方向の塗布膜厚が不均一になることが防がれるため、製造される電磁波遮蔽フィルムの光学特性の均一性は、良好である。つまり、層数を増しても同時重層塗布を良好に実施することが可能である。 Therefore, since the pressure difference ΔP related to the pocket portion 53 that is the minimum thickness portion of the bar 40 and easily deforms due to the pressure is small, the deformation of the bar 40 is suppressed, and the uniformity of the gap in the coating width direction is maintained. Since the coating film thickness in the coating width direction is prevented from becoming non-uniform, the uniformity of the optical characteristics of the manufactured electromagnetic wave shielding film is good. That is, even when the number of layers is increased, simultaneous multilayer coating can be carried out satisfactorily.
　なお、高屈折率層塗布液Ｌ１、低屈折率層塗布液Ｌ２およびフィルム基材２２は、塗布時に昇温されている。そのため、フィルム基材２２に塗布された高屈折率層塗布液Ｌ１および低屈折率層塗布液Ｌ２は、一旦１～１５℃に冷却された後、乾燥工程に投入され、１０℃以上、例えば、湿球温度５～５０℃かつ塗布面温度１０～５０℃で乾燥される。 The high refractive index layer coating liquid L 1 , the low refractive index layer coating liquid L 2 and the film substrate 22 are heated during coating. Therefore, the high refractive index layer coating liquid L 1 and the low refractive index layer coating liquid L 2 applied to the film base material 22 are once cooled to 1 to 15 ° C. and then put into a drying step, and 10 ° C. or higher. For example, drying is performed at a wet bulb temperature of 5 to 50 ° C. and an application surface temperature of 10 to 50 ° C.
　次に、層数を増しても同時重層塗布を良好に実施し得る条件が、詳述される。 Next, the conditions under which simultaneous multilayer coating can be satisfactorily performed even when the number of layers is increased will be described in detail.
　図９は、電磁波遮蔽フィルムの膜厚変動率に対するバーのポケット部の厚みおよび圧力差の影響を説明するための試験結果を示しているテーブル、図１０は、電磁波遮蔽フィルムの膜厚変動率および圧力差に対する塗布液粘度の影響を説明するための試験結果を示しているテーブル、図１１は、電磁波遮蔽フィルムの膜厚変動率に対するスリット間隔の影響を説明するための試験結果を示しているテーブルである。 FIG. 9 is a table showing test results for explaining the influence of the thickness of the bar pocket portion and the pressure difference on the film thickness fluctuation rate of the electromagnetic wave shielding film, and FIG. 10 shows the film thickness fluctuation rate of the electromagnetic wave shielding film and FIG. 11 is a table showing test results for explaining the influence of the slit interval on the film thickness variation rate of the electromagnetic wave shielding film. FIG. 11 is a table showing the test results for explaining the influence of the coating liquid viscosity on the pressure difference. It is.
　まず、試験に係る共通の条件（低屈折率層塗布液の調製条件、高屈折率層塗布液の調製条件および塗布条件）が、説明される。 First, common conditions (preparation conditions for a low refractive index layer coating solution, preparation conditions for a high refractive index layer coating solution and coating conditions) related to the test will be described.
　低屈折率層塗布液は、コロイダルシリカ（スノーテックスＯＸＳ、日産化学工業社製、固形分１０質量％）１２質量部に、ポリビニルアルコール（ＰＶＡ―１０３、重合度３００、鹸化度９８．５ｍｏｌ％、クラレ社製）の５質量％水溶液２質量部と、３質量％ホウ酸水溶液１０質量部とをそれぞれ添加した後、４５℃に加熱し、撹拌しながら、ポリビニルアルコール（ＰＶＡ―１１７、重合度１７００、鹸化度９８．５ｍｏｌ％、クラレ社製）の５質量％水溶液２０質量部と、界面活性剤（ラピゾールＡ３０、日油社製）の１質量％水溶液１質量部とを添加し、さらに純水５５質量部を加えて、攪拌混合することによって、調製された。 The coating solution for the low refractive index layer is composed of 12 parts by mass of colloidal silica (Snowtex OXS, manufactured by Nissan Chemical Industries, Ltd., solid content 10% by mass), polyvinyl alcohol (PVA-103, polymerization degree 300, saponification degree 98.5 mol%, 2 parts by weight of a 5% by weight aqueous solution of Kuraray Co., Ltd. and 10 parts by weight of a 3% by weight aqueous boric acid solution were added, and the mixture was then heated to 45 ° C. and stirred while polyvinyl alcohol (PVA-117, polymerization degree 1700). 20 parts by mass of a 5% by mass aqueous solution of a saponification degree of 98.5 mol%, manufactured by Kuraray Co., Ltd., and 1 part by mass of a 1% by mass aqueous solution of a surfactant (Rapidol A30, manufactured by NOF Corporation) are further added. It was prepared by adding 55 parts by weight and stirring and mixing.
　高屈折率層塗布液は、シリカ付着二酸化チタンゾル（固形分２０．０質量％）３０質量部に、ポリビニルアルコール（ＰＶＡ―１０３、重合度３００、鹸化度９８．５ｍｏｌ％、クラレ社製）の５質量％水溶液２質量部と、３質量％ホウ酸水溶液１０質量部と、２質量％クエン酸水溶液１０質量部とをそれぞれ添加した後、４５℃に加熱し、撹拌しながら、ポリビニルアルコール（ＰＶＡ―６１７、重合度１７００、鹸化度９５．０ｍｏｌ％、クラレ社製）の５質量％水溶液２０質量部と、界面活性剤（ラピゾールＡ３０、日油社製）の１質量％水溶液１質量部とを添加し、さらに純水２７質量部を加えて、攪拌混合することによって、調製された。 The coating solution for the high refractive index layer is 5 parts of polyvinyl alcohol (PVA-103, polymerization degree 300, saponification degree 98.5 mol%, manufactured by Kuraray Co., Ltd.) in 30 parts by mass of silica-attached titanium dioxide sol (solid content 20.0% by mass). After adding 2 parts by weight of a 2% by weight aqueous solution, 10 parts by weight of a 3% by weight aqueous boric acid solution, and 10 parts by weight of a 2% by weight aqueous citric acid solution, the mixture was heated to 45 ° C. and stirred with polyvinyl alcohol (PVA- 617, polymerization degree 1700, saponification degree 95.0 mol%, manufactured by Kuraray Co., Ltd.) 20 mass parts of 5 mass% aqueous solution and surfactant (rapizole A30, manufactured by NOF Corporation) 1 mass% aqueous solution 1 mass part was added. Further, 27 parts by mass of pure water was added, and the mixture was stirred and mixed.
　なお、シリカ付着二酸化チタンゾルは、１５．０質量％酸化チタンゾル（ＳＲＤ－Ｗ、体積平均粒径５ｎｍ、ルチル型二酸化チタン粒子、堺化学社製）０．５質量部に、純水２質量部を加えて、９０℃に加熱し、ケイ酸水溶液（ケイ酸ソーダ４号（日本化学社製）をＳｉＯ２濃度が２．０質量％となるように純水で希釈したもの）１．３質量部を、徐々に添加し、そして、オートクレーブ中、１７５℃で１８時間加熱処理を行い、冷却後、限外濾過膜にて濃縮することにより、得られた。 The silica-attached titanium dioxide sol is composed of 15.0 mass% titanium oxide sol (SRD-W, volume average particle size 5 nm, rutile titanium dioxide particles, manufactured by Sakai Chemical Co., Ltd.) 0.5 mass parts, and 2 mass parts of pure water. In addition, the mixture was heated to 90 ° C., and an aqueous silicic acid solution (a solution of sodium silicate 4 (manufactured by Nippon Chemical Co., Ltd.) diluted with pure water so that the SiO 2 concentration was 2.0 mass%) Was gradually added, and heat treatment was performed at 175 ° C. for 18 hours in an autoclave. After cooling, the solution was concentrated by an ultrafiltration membrane.
　低屈折率層塗布液および高屈折率層塗布液は、４５℃に保温して、ダイコーターに供給され、１５層の同時重層塗布が実施された。また、最下層および最上層は、低屈折率層となっており、低屈折率層は、高屈折率層より１つ多く含まれていた。 The low-refractive index layer coating solution and the high-refractive index layer coating solution were kept at 45 ° C. and supplied to the die coater, and 15 layers were simultaneously coated. In addition, the lowermost layer and the uppermost layer are low refractive index layers, and one low refractive index layer is included more than the high refractive index layer.
　フィルム基材は、厚さ５０μｍかつ幅２０００ｍｍのポリエチレンテレフタレートフィルム（東洋紡社製Ａ４３００：両面易接着層）からなり、塗布液の塗布時、４５℃に昇温された。ダイコーターのフロントバーおよびバックバーは、厚さ４０ｍｍのものが使用された。塗布速度および塗布幅は、５０ｍ／ｍｉｎおよび１９５０ｍｍに設定された。低屈折率層および高屈折率層の塗布厚みは、乾燥時の平均膜厚として１５０ｎｍとなるように設定された。 The film substrate was formed of a polyethylene terephthalate film (Toyobo Co., Ltd. A4300: double-sided easy-adhesion layer) having a thickness of 50 μm and a width of 2000 mm, and the temperature was raised to 45 ° C. during application of the coating solution. The front bar and back bar of the die coater were 40 mm thick. The coating speed and coating width were set to 50 m / min and 1950 mm. The coating thickness of the low refractive index layer and the high refractive index layer was set to be 150 nm as an average film thickness during drying.
　次に、電磁波遮蔽フィルムの膜厚変動率の算出方法を説明する。 Next, a method of calculating the film thickness fluctuation rate of the electromagnetic wave shielding film will be described.
　電磁波遮蔽フィルムの膜厚変動率Ｖ［％］は、膜厚変動幅を膜厚平均値によって除し、１００を乗じた値である。膜厚変動幅は、膜厚の最小値と最大値との差である。膜厚平均値は、塗布幅方向に５０ｍｍ間隔で測定された膜厚の全幅に関する平均値である。 The film thickness fluctuation rate V [%] of the electromagnetic wave shielding film is a value obtained by dividing the film thickness fluctuation width by the film thickness average value and multiplying by 100. The film thickness variation width is a difference between the minimum value and the maximum value of the film thickness. The film thickness average value is an average value related to the entire width of the film thickness measured at intervals of 50 mm in the coating width direction.
　膜厚は、各層毎に測定された。測定は、上記条件で製造された電磁波遮蔽フィルムの断面を、電子顕微鏡（ＦＥ－ＳＥＭ、Ｓ－５０００Ｈ型、日立製作所製）を用いて、加速電圧２．０ｋＶの条件で１ｃｍ長さが観察できるように視野数を選んで観察し、得られた画像を、デジタル化し、コントラストを調整する画像処理を施した後で、実施された。なお、膜厚は、１０００箇所の測定結果の平均値である。 The film thickness was measured for each layer. In the measurement, a cross section of the electromagnetic wave shielding film manufactured under the above conditions can be observed with a length of 1 cm under the condition of an acceleration voltage of 2.0 kV using an electron microscope (FE-SEM, S-5000H type, manufactured by Hitachi, Ltd.). Thus, the number of fields of view was selected and observed, and the obtained image was digitized and subjected to image processing for adjusting contrast. The film thickness is an average value of 1000 measurement results.
　次に、図９の試験結果を参照し、電磁波遮蔽フィルムの膜厚変動率に対するバーのポケット部の厚みおよび圧力差の影響を説明する。 Next, with reference to the test result of FIG. 9, the influence of the thickness of the bar pocket and the pressure difference on the rate of film thickness variation of the electromagnetic shielding film will be described.
　バーのポケット部の厚みＤ４は、５～２０ｍｍの範囲で変化させ、かつ、圧力差ΔＰは、低屈折率層塗布液Ｌ２の供給量を変えて０．０２～０．１５ＭＰａの範囲で変化させた。圧力差ΔＰは、低屈折率層塗布液Ｌ２が供給されるバーのポケット部の凹部の内圧Ｐ２と、高屈折率層塗布液Ｌ１が供給されるバーのポケット部の凹部の内圧Ｐ１と、の圧力差である。スリット間隙は、０．２ｍｍ、高屈折率層塗布液および低屈折率層塗布液粘度は、１０ｍＰａ・ｓおよび１００ｍＰａ・ｓに設定された。 The thickness D 4 of the pocket portion of the bars, varied from 5 ~ 20 mm, and the pressure difference ΔP is in a range of 0.02 ~ 0.15 MPa by changing the supply amount of the low refractive index layer coating solution L 2 Changed. The pressure difference ΔP is, the internal pressure P 2 of the recess of the pocket portion of the bar having a low refractive index layer coating solution L 2 is supplied, the recess of the pocket portion of the bar which high refractive index layer coating solution L 1 is supplied internal pressure P 1 and the pressure difference. The slit gap was 0.2 mm, and the viscosity of the high refractive index layer coating solution and the low refractive index layer coating solution was set to 10 mPa · s and 100 mPa · s.
　図９に示されるように、バーのポケット部の厚みＤ４が２０ｍｍである場合、圧力差ΔＰに係らず、塗膜乱れが見られた。一方、バーのポケット部の厚みＤ４が１５ｍｍ以下であり、かつ、圧力差ΔＰが０．１ＭＰａ以下である場合、塗膜乱れは見られず、膜厚変動率（Ｖ）が３．０％以下である均一な塗膜を得ることができた。 As shown in FIG. 9, when the thickness D 4 of the pocket portion of the bar is 20 mm, regardless of the pressure difference [Delta] P, the coating disturbance was observed. On the other hand, it is the thickness D 4 of the pocket portion of the bar is 15mm or less, and, when the pressure difference ΔP is 0.1MPa or less, the coating film disturbance is not observed, the thickness variation rate (V) is 3.0% The following uniform coating film could be obtained.
　つまり、バーのポケット部の厚みＤ４が１５ｍｍ以下であっても、圧力差ΔＰが０．１ＭＰａ以下である場合、バーの変形を抑制することが可能であり、塗布幅方向の隙間の均一性が維持された。 That is, even less bar pocket portion thickness D 4 is 15mm in the case the pressure difference ΔP is 0.1MPa or less, it is possible to suppress deformation of the bar, the uniformity of the gap between the coating width Was maintained.
　なお、バーの肉厚の下限には制約は無く、薄ければ薄いほど層数を増やすことが可能である。しかし、バーのポケット部の厚みＤ４は、過度に小さくなると、圧力差ΔＰの影響を受け易くなるため、５ｍｍ以上が好ましい。 There is no restriction on the lower limit of the wall thickness of the bar. The thinner the bar, the greater the number of layers. However, the thickness D 4 of the pocket portion of the bar, an excessively reduced, it becomes susceptible to the pressure difference [Delta] P, is preferably at least 5 mm.
　次に、図１０を参照し、電磁波遮蔽フィルムの膜厚変動率および圧力差に対する塗布液粘度の影響が説明される。なお、テーブル中の数値は、圧力差ΔＰ［ＭＰａ］を示している。 Next, with reference to FIG. 10, the influence of the coating solution viscosity on the film thickness variation rate and pressure difference of the electromagnetic wave shielding film will be described. In addition, the numerical value in a table has shown pressure difference (DELTA) P [MPa].
　低屈折率層塗布液粘度μ２は、５０～２０００ｍＰａ・ｓの範囲で変化させ、かつ、高屈折率層塗布液粘度μ１は、１～３０ｍＰａ・ｓの範囲で変化させた。バーのポケット部の厚みＤ４は１２，５ｍｍ、スリット間隙Ｄ３は、０．２ｍｍに設定された。なお、粘度の調整方法は、特に限定されず、例えば、溶媒とバインダーの比率を変更することによって調整することが可能である。 The low refractive index layer coating solution viscosity μ 2 was changed in the range of 50 to 2000 mPa · s, and the high refractive index layer coating solution viscosity μ 1 was changed in the range of 1 to 30 mPa · s. The thickness D 4 of the pocket portion of the bar 12,5Mm, slit gap D 3 was set to 0.2 mm. In addition, the adjustment method of a viscosity is not specifically limited, For example, it can adjust by changing the ratio of a solvent and a binder.
　図１０に示されるように、膜厚変動率（Ｖ）が３．０％を超えているものと、膜厚変動率（Ｖ）が３．０％以下であるものとが、明確に分かれており、その境界は、低屈折率層塗布液粘度μ２および高屈折率層塗布液粘度μ１を使用した１次式で近似すると、μ２＝４×μ１＋１００であった。つまり、関係式（μ２≦４×μ１＋１００）を満たす場合、膜厚変動率（Ｖ）が３．０％以下の均一な塗膜を得ることができた。なお、圧力差ΔＰは、０．１ＭＰａ以下であった。 As shown in FIG. 10, the film thickness variation rate (V) exceeds 3.0% and the film thickness variation rate (V) is 3.0% or less. The boundary was approximately μ 2 = 4 × μ1 + 100 when approximated by a linear expression using the low refractive index layer coating solution viscosity μ 2 and the high refractive index layer coating solution viscosity μ 1 . That is, when the relational expression (μ 2 ≦ 4 × μ1 + 100) was satisfied, a uniform coating film having a film thickness variation rate (V) of 3.0% or less could be obtained. The pressure difference ΔP was 0.1 MPa or less.
　次に、図１１を参照し、電磁波遮蔽フィルムの膜厚変動率に対するスリット間隔の影響が説明される。 Next, with reference to FIG. 11, the influence of the slit interval on the film thickness variation rate of the electromagnetic shielding film will be described.
　高屈折率層塗布液Ｌ１が通過するスリット５８のスリット間隙Ｄ３１は、０．０４～０．３ｍｍの範囲で変化させ、かつ、低屈折率層塗布液Ｌ２が通過するスリット５８のスリット間隙Ｄ３２は、０．１５～０．５ｍｍの範囲で変化させた。バーのポケット部の厚みＤ４は、１２．５ｍｍ、高屈折率層塗布液粘度μ１および低屈折率層塗布液粘度μ２は、１０ｍＰａ・ｓおよび１００ｍＰａ・ｓに設定された。 The slit gap D 31 of the slit 58 through which the high refractive index layer coating liquid L 1 passes is changed in the range of 0.04 to 0.3 mm, and the slit of the slit 58 through which the low refractive index layer coating liquid L 2 passes. gap D 32 was changed in the range of 0.15 ~ 0.5 mm. The thickness D 4 of the pocket portion of the bars, 12.5 mm, the high-refractive index layer coating solution viscosity mu 1 and the low refractive index layer coating solution viscosity mu 2 was set to 10 mPa · s and 100 mPa · s.
　図１１に示されるように、スリット間隙Ｄ３１，Ｄ３２が、０．０５ｍｍ以上かつ０．４ｍｍ以下であって、かつ、スリット間隙Ｄ３２をスリット間隙Ｄ３１より大きくする場合、膜厚変動率（Ｖ）が３．０％以下の均一な塗膜を得ることができた。なお、スリット間隙Ｄ３２が、スリット間隙Ｄ３１の５倍を超える場合、圧力損失が小さくなりすぎて、低屈折率層塗布液Ｌ２が塗布幅方向に均一に流出しなくなる恐れがある。したがって、スリット間隙Ｄ３２は、スリット間隙Ｄ３１の５倍以下であることが好ましい。 As shown in FIG. 11, when the slit gaps D 31 and D 32 are 0.05 mm or more and 0.4 mm or less and the slit gap D 32 is larger than the slit gap D 31 , the film thickness variation rate A uniform coating film having (V) of 3.0% or less could be obtained. The slit gap D 32 is, if more than five times the slit gap D 31, the pressure loss is too small, there is a possibility that the low refractive index layer coating solution L 2 is not uniformly flow out across the coating width. Therefore, the slit gap D 32 is preferably not more than 5 times the slit gap D 31.
　高屈折率層塗布液Ｌ１が通過するスリット５８のスリット間隙Ｄ３１が０．０５ｍｍの場合、低屈折率層塗布液Ｌ２が通過するスリット５８のスリット間隙Ｄ３２が０．１５～０．４ｍｍの範囲の範囲において、膜厚変動率（Ｖ）は、３．０％以下であるが１．０％を超えている。これは、スリット間隙Ｄ３１が０．０５ｍｍの場合、塗布幅方向の均一なスリットを製作することが困難であったためである。 If the slit gap D 31 of the slit 58 the high refractive index layer coating solution L 1 passes is 0.05 mm, the slit gap D 32 of the slit 58 having a low refractive index layer coating solution L 2 passes from 0.15 to zero. In the range of 4 mm, the film thickness variation rate (V) is 3.0% or less but exceeds 1.0%. This is because when the slit gap D 31 is 0.05 mm, is because it was difficult to manufacture a uniform slit in the coating width direction.
　低屈折率層塗布液Ｌ２が通過するスリット５８のスリット間隙Ｄ３２が０．４ｍｍの場合、高屈折率層塗布液Ｌ１が通過するスリット５８のスリット間隙Ｄ３１が、０．０５～０．３ｍｍの範囲において、膜厚変動率（Ｖ）は、３．０％以下であるが１．０％を超えている。これは、スリット間隙Ｄ３２が狭すぎるため、低屈折率層塗布液Ｌ２が通過する際に発生する圧力損失が過度に小さくなり、塗布液が塗布幅方向に均一に流出しなくなったためである。 If the slit gap D 32 of the slit 58 having a low refractive index layer coating solution L 2 passes is 0.4 mm, the slit gap D 31 of the slit 58 that passes through the high-refractive index layer coating solution L 1 is 0.05 to 0 In the range of 0.3 mm, the film thickness variation rate (V) is 3.0% or less, but exceeds 1.0%. This is because the slit gap D 32 is too narrow, the pressure loss generated when the low refractive index layer coating solution L 2 passes becomes excessively small, is because the coating solution is no longer uniformly flows out across the coating width .
　以上のように、本実施の形態においては、バーのポケット部の厚みが１５ｍｍ以下であり、バーを薄くすることが可能であり、バーの設置数（塗布層数）を増しても、塗布液が流下するバーの端面により構成されるスライド面が長くなることが抑制される。また、塗布工程において、第２塗布液が供給されるバーのポケット部の凹部の内圧と、第１塗布液が供給されるバーのポケット部の凹部の内圧と、の圧力差が、０．１ＭＰａ以下になるように設定されている。つまり、バーの最小肉厚部であり、圧力の影響を受けて変形し易いポケット部における圧力差が小さいため、バーの変形が抑制され、塗布幅方向の隙間の均一性が維持され、塗布幅方向の塗布膜厚が不均一になることが防がれるため、製造される電磁波遮蔽フィルムの光学特性の均一性は、良好である。したがって、層数を増しても同時重層塗布を良好に実施することができる電磁波遮蔽フィルムの製造方法を提供することが可能である。 As described above, in the present embodiment, the thickness of the pocket portion of the bar is 15 mm or less, the bar can be thinned, and even if the number of installed bars (number of coating layers) is increased, the coating solution It is suppressed that the slide surface comprised by the end surface of the bar | burr which flows down becomes long. In the coating process, the pressure difference between the internal pressure of the concave portion of the pocket portion of the bar supplied with the second coating liquid and the internal pressure of the concave portion of the pocket portion of the bar supplied with the first coating liquid is 0.1 MPa. It is set to be as follows. In other words, it is the minimum wall thickness of the bar, and since the pressure difference in the pocket that is easily deformed under the influence of pressure is small, the deformation of the bar is suppressed, and the uniformity of the gap in the coating width direction is maintained. Since the coating film thickness in the direction is prevented from becoming uneven, the uniformity of the optical properties of the manufactured electromagnetic wave shielding film is good. Therefore, it is possible to provide a method for producing an electromagnetic wave shielding film that can satisfactorily perform simultaneous multilayer coating even when the number of layers is increased.
　本発明は、上述した実施の形態に限定されるものではなく、特許請求の範囲で種々改変することができる。例えば、電磁波遮蔽フィルムは、遠赤外線反射フィルムや紫外線反射フィルムに適用することが可能である。この場合、交互に積層される高屈折率層および低屈折率層の光学膜厚を調整することによって、近赤外光に替えて可視光や紫外光を反射するように設計される。 The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the claims. For example, the electromagnetic wave shielding film can be applied to a far-infrared reflective film or an ultraviolet reflective film. In this case, it is designed to reflect visible light or ultraviolet light instead of near-infrared light by adjusting the optical film thickness of the high refractive index layer and the low refractive index layer that are alternately stacked.
　高屈折率層と低屈折率層とが交互に積層した構造は、例えば、フィルム基材の一方の面に、同時重層塗布を実施して乾燥した後で、フィルム基材の他方の面に、同時重層塗布を実施して乾燥することによって、電磁波遮蔽フィルムの両面に配置することも可能である。高屈折率層と低屈折率層とが交互に積層した構造の最下層および最上層に、高屈折率層を配置して、高屈折率層の設置数を、低屈折率層より大きくすることも可能である。また、低屈折率層と高屈折率層の設置数を同一とすることも可能である。 The structure in which the high refractive index layer and the low refractive index layer are alternately laminated is, for example, on the other surface of the film substrate after the simultaneous multilayer coating is performed on one surface of the film substrate and dried. It is also possible to arrange on both surfaces of the electromagnetic wave shielding film by performing simultaneous multilayer coating and drying. A high refractive index layer is arranged on the lowermost layer and the uppermost layer of a structure in which a high refractive index layer and a low refractive index layer are alternately stacked, and the number of high refractive index layers to be installed is larger than that of the low refractive index layer. Is also possible. It is also possible to make the number of low refractive index layers and high refractive index layers the same.
　フィルム基材を吸引し、その形状の歪みを矯正する減圧機構を、塗布装置のバックロールの近傍に配置し、ダイコーターとフィルム基材との間のクリアランス精度を向上させることも可能である。 It is also possible to improve the clearance accuracy between the die coater and the film substrate by arranging a decompression mechanism that sucks the film substrate and corrects the distortion of its shape in the vicinity of the back roll of the coating apparatus.
　別の機能を有する層を、フィルム基材と塗布層との間や、塗布層の表面に配置することが可能である。例えば、フィルム基材と塗布層との間にガスバリア層や易接着層を配置したり、塗布層の表面にハードコート層や耐摩耗性層を配置したりすることも可能である。 It is possible to arrange a layer having another function between the film base and the coating layer or on the surface of the coating layer. For example, it is possible to dispose a gas barrier layer or an easy-adhesion layer between the film substrate and the coating layer, or to dispose a hard coat layer or an abrasion-resistant layer on the surface of the coating layer.
　本出願は、２０１３年６月２８日に出願された日本特許出願番号２０１３－１３７０６８号に基づいており、それらの開示内容は、参照され、全体として、組み入れられている。 This application is based on Japanese Patent Application No. 2013-137068 filed on June 28, 2013, the disclosures of which are referenced and incorporated as a whole.
１０　塗布装置、
２０　搬送系、
２２　フィルム基材、
２４　バックロール、
３０　ダイコーター、
３２　積層体、
４０　バー、
４２　フロントバー、
４４　中間バー、
４６　バックバー、
５０　基端部、
５１　端面、
５２　貫通孔、
５３　ポケット部
５４　凹部、
５６　先端部、
５７　端面、
５８　スリット、
６０　側方壁部、
７０　塗布液供給系、
７２　調製釜、
７３　配管系、
７４　ポンプ、
７６　調製釜、
７７　配管系、
７８　ポンプ、
８１，８２　圧力センサー、
Ｄ１，Ｄ２，Ｄ３，Ｄ３１，Ｄ３２，Ｄ４　厚み、
Ｆ　塗布方向、
Ｌ，Ｌ１，Ｌ２　塗布液、
Ｗ　塗布幅方向、
μ１，μ２　粘度。 10 coating device,
20 transport system,
22 film substrate,
24 Backroll,
30 Die coater,
32 laminates,
40 bars,
42 Front bar,
44 middle bar,
46 Backbar,
50 proximal end,
51 end face,
52 through holes,
53 pocket part 54 recess,
56 tip,
57 end face,
58 slits,
60 side wall,
70 coating solution supply system,
72 preparation kettle,
73 Piping system,
74 pumps,
76 Preparation kettle,
77 Piping system,
78 pump,
81,82 pressure sensor,
D 1 , D 2 , D 3 , D 31 , D 32 , D 4 thickness,
F coating direction,
L, L 1 , L 2 coating solution,
W coating width direction,
μ1, μ2 Viscosity.

Claims (5)

  1. 　高屈折率層と低屈折率層とが交互に積層した構造を有する電磁波遮蔽フィルムの製造方法において、
    　複数の積層されたバーを有するスライド式ダイコーターを用いて、前記高屈折率層を構成することとなる第１塗布液の塗布層と、前記低屈折率層を構成することとなる第２塗布液の塗布層とを交互に積層させて、フィルム基材に同時重層塗布する塗布工程を、有しており、
    　前記バーは、隣接する別のバーとの間に隙間を形成する先端部と、前記別のバーと当接する基端部と、前記先端部と前記基端部との間に位置し、塗布液溜まり部である凹部を有するポケット部と、を有し、
    　前記ポケット部の厚みは、１５ｍｍ以下であり、
    　前記塗布工程において、前記第２塗布液が供給されるバーのポケット部の凹部の内圧と、前記第１塗布液が供給されるバーのポケット部の凹部の内圧との圧力差は、０．１ＭＰａ以下になるように設定されている電磁波遮蔽フィルムの製造方法。     In the method for producing an electromagnetic wave shielding film having a structure in which high refractive index layers and low refractive index layers are alternately laminated,
    Using a slide type die coater having a plurality of stacked bars, the first coating liquid coating layer that constitutes the high refractive index layer and the second coating that constitutes the low refractive index layer. It has an application process of alternately laminating the liquid application layers and simultaneously applying multiple layers on the film substrate,
    The bar is located between a tip portion that forms a gap with another adjacent bar, a base end portion that contacts the other bar, and the tip portion and the base end portion. A pocket portion having a recess which is a reservoir portion,
    The pocket portion has a thickness of 15 mm or less,
    In the coating step, the pressure difference between the internal pressure of the concave portion of the pocket portion of the bar supplied with the second coating liquid and the internal pressure of the concave portion of the pocket portion of the bar supplied with the first coating liquid is 0.1 MPa. The manufacturing method of the electromagnetic wave shielding film set so that it may become below.
  2. 　前記第１塗布液の粘度μ１［ｍＰａ・ｓ］および前記第２塗布液の粘度μ２［ｍＰａ・ｓ］は、関係式（μ２≦４×μ１＋１００）を満たしている請求項１に記載の電磁波遮蔽フィルムの製造方法。 The viscosity μ 1 [mPa · s] of the first coating liquid and the viscosity μ 2 [mPa · s] of the second coating liquid satisfy a relational expression (μ 2 ≦ 4 × μ1 + 100). Manufacturing method of electromagnetic wave shielding film.
  3. 　前記第１塗布液が供給されるバーの先端部の隙間の厚みであるスリット間隙Ｄ３１［ｍｍ］および前記第２塗布液が供給されるバーの先端部の隙間の厚みであるスリット間隙Ｄ３２［ｍｍ］は、０．０５以上かつ０．４以下であり、かつ、
    　前記スリット間隙Ｄ３２は、前記スリット間隙Ｄ３１より大きい請求項１に記載の電磁波遮蔽フィルムの製造方法。     A slit gap D 31 [mm] which is the thickness of the gap at the tip of the bar to which the first coating liquid is supplied and a slit gap D 32 which is the thickness of the gap at the tip of the bar to which the second coating liquid is supplied. [Mm] is 0.05 or more and 0.4 or less, and
    The method for manufacturing an electromagnetic wave shielding film according to claim 1, wherein the slit gap D 32 is larger than the slit gap D 31 .
  4. 　前記第１塗布液の粘度μ１［ｍＰａ・ｓ］は、３以上かつ３０以下であり、
    　前記第２塗布液の粘度μ２［ｍＰａ・ｓ］は、５０以上かつ５００以下である請求項２に記載の電磁波遮蔽フィルムの製造方法。     The viscosity μ 1 [mPa · s] of the first coating solution is 3 or more and 30 or less,
    The method for producing an electromagnetic wave shielding film according to claim 2, wherein the viscosity μ 2 [mPa · s] of the second coating liquid is 50 or more and 500 or less.
  5. 　電磁波遮蔽フィルムは、近赤外光を反射する機能を有する請求項１～４のいずれか１項に記載の電磁波遮蔽フィルムの製造方法。 The method for producing an electromagnetic wave shielding film according to any one of claims 1 to 4, wherein the electromagnetic wave shielding film has a function of reflecting near infrared light.
PCT/JP2014/060960 2013-06-28 2014-04-17 Method for manufacturing electromagnetic-wave-shielding film WO2014208183A1 (en)

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JP2003010762A (en) * 2001-06-28 2003-01-14 Konica Corp Coating apparatus and coating method
JP2003126761A (en) * 2001-10-29 2003-05-07 Konica Corp Coating method
JP2009295980A (en) * 2008-06-02 2009-12-17 Dongjin Semichem Co Ltd Electromagnetic wave shielding filter and its manufacturing method, and display device
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JP2012183452A (en) * 2011-03-03 2012-09-27 Fujifilm Corp Method for producing laminated film
JP2013000667A (en) * 2011-06-17 2013-01-07 Konica Minolta Holdings Inc Manufacturing method for infrared shielding film

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CN1997460A (en) * 2004-06-17 2007-07-11 富士胶片株式会社 Process for producing coating film, antireflection film and process for producing the same, sheet polarizer using the film, and image display device using these

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JPH08266978A (en) * 1995-03-31 1996-10-15 Fuji Photo Film Co Ltd Coating apparatus and method
JP2003010762A (en) * 2001-06-28 2003-01-14 Konica Corp Coating apparatus and coating method
JP2003126761A (en) * 2001-10-29 2003-05-07 Konica Corp Coating method
JP2009295980A (en) * 2008-06-02 2009-12-17 Dongjin Semichem Co Ltd Electromagnetic wave shielding filter and its manufacturing method, and display device
JP2012150226A (en) * 2011-01-18 2012-08-09 Dainippon Printing Co Ltd Antireflection film, method for manufacturing antireflection film and image display device
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