Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
  • B32B7/02—Physical, chemical or physicochemical properties
  • B32B7/023—Optical properties
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
  • G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
  • G02B1/11—Anti-reflection coatings
  • G02B1/113—Anti-reflection coatings using inorganic layer materials only
  • G02B1/115—Multilayers
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
  • G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
  • G02B1/14—Protective coatings, e.g. hard coatings

Definitions

• the present invention relates to an anti-reflective film.
• Anti-reflection films are known that are placed on the outer surface of the display screen of display devices such as liquid crystal displays and organic EL displays.
• the anti-reflection film suppresses reflection of external light and glare of images on the display screen (anti-reflection properties).
• the anti-reflection film comprises, for example, an anti-reflection layer made of an inorganic oxide and a resin base film that supports the layer. Such an anti-reflection film is described, for example, in Patent Document 1 below.
• the anti-reflection film described in Patent Document 1 comprises a substrate film, an adhesion layer, and an anti-reflection layer in this order in the thickness direction.
• the substrate film has a hard coat (HC) layer on the adhesion layer side.
• This HC layer contains silica particles.
• the HC layer has surface irregularities on the adhesion layer side.
• the adhesion of the anti-reflection layer to the substrate film is improved by the anchor effect due to the surface irregularities of the HC layer and the physicochemical action of the adhesion layer. If the adhesion of the anti-reflection layer to the substrate film is insufficient, the anti-reflection layer will peel off from the substrate film.
• the surface of the anti-reflective layer (the surface opposite the substrate film) also has surface irregularities that follow the surface irregularities of the HC layer.
• the surface irregularities of the anti-reflective layer scatter a portion of the light that is incident on the anti-reflective film.
• the silica particles in the HC layer also scatter a portion of the light that is incident on the anti-reflective film. In an anti-reflective film, the more the incident light is scattered, the lower the anti-reflective properties become.
• the present invention provides an anti-reflection film that provides good anti-reflection effects while ensuring adhesion of the anti-reflection layer to the substrate film.
• the present invention [1] is an anti-reflection film comprising a substrate film, an adhesive layer on the substrate film, and an anti-reflection layer on the adhesive layer, the anti-reflection layer including a high refractive index layer in contact with the adhesive layer and a low refractive index layer on the high refractive index layer, the surface roughness Sa of the surface of the anti-reflection layer opposite the substrate film is 4.5 nm or less, and the ratio of the second interface length at the interface between the high refractive index layer and the low refractive index layer to the first interface length at the interface between the substrate film and the adhesive layer in a cross-sectional view in the thickness direction of the anti-reflection film is 1.10 or more.
• the present invention [2] includes the anti-reflection film described in [1] above, in which the ratio is 2.00 or less.
• the present invention [3] includes the anti-reflection film described in [1] or [2] above, in which the total reflectance of light irradiated on the anti-reflection layer side with a wavelength of 380 nm to 780 nm from a standard light source D65 is 0.40% or less.
• the present invention [4] includes the anti-reflection film according to any one of the above [1] to [3], which has a moisture permeability of 100 g/ m2 ⁇ 24 h or more.
• the present invention [5] includes the anti-reflection film according to any one of [1] to [4] above, in which the peeling rate of the anti-reflection layer in the second test below after the first test below is less than 20%.
• Test 1 First, the substrate film side of the antireflection film is fixed to a glass plate, and then the antireflection layer of the antireflection film on the glass plate is irradiated with light for 32.5 hours under conditions of a temperature of 85° C., a relative humidity of 45%, and an irradiation intensity (integrated illuminance from 290 nm to 450 nm) of 150 mW/ cm2 .
• Test 2 First, eleven parallel first incisions (2 mm apart) extending linearly in a first direction and eleven parallel second incisions (2 mm apart) extending linearly in a second direction perpendicular to the first direction are formed on the anti-reflection layer and the adhesive layer of the anti-reflection film on the glass plate by a cutter knife, and 100 squares are formed by the first and second incisions.
• isopropyl alcohol is continuously dropped at 2 mL/min on the area of the 100 squares on the anti-reflection film, while a polyester wiper is slid under the conditions of a wiper contact surface of 20 mm x 20 mm, a load of 1.5 kg/20 mm, a sliding speed of 50 mm/sec, and 1000 reciprocations.
• the number of squares in which peeling of 1 mm2 or more has occurred is counted among the 100 squares.
• the count number is divided by 100 to calculate the peeling rate (%).
• the surface roughness Sa of the surface of the anti-reflection layer opposite the substrate film is 4.5 nm or less, and the ratio of the second interface length at the interface between the high refractive index layer and the low refractive index layer to the first interface length at the interface between the substrate film and the adhesive layer is 1.10 or more in a cross-sectional view in the thickness direction.
• the surface roughness Sa of the anti-reflection layer is 4.5 nm or less, so that scattering of light incident on the anti-reflection film at the surface of the anti-reflection layer can be suppressed.
• the anti-reflection layer is formed on the substrate film via the adhesive layer, and the ratio of the first and second interface lengths is 1.10 or more, so that the adhesion of the anti-reflection layer to the substrate film can be ensured. Therefore, according to the anti-reflection film of the present invention, a good reflection suppression effect can be obtained while ensuring the adhesion of the anti-reflection layer to the substrate film.
• FIG. 1 is a schematic cross-sectional view of one embodiment of an anti-reflection film of the present invention.
• 2 shows an example of a method for producing the anti-reflection film shown in Fig. 1.
• Fig. 2A shows a cured resin layer forming step
• Fig. 2B shows an adhesion layer forming step
• Fig. 2C shows an anti-reflection layer forming step.
• 2 is a schematic diagram of an apparatus for carrying out a plasma treatment step and a film formation step in the example of the method for producing the antireflection film shown in FIG. 1.
• 4 is a perspective view showing the positional relationship between a low inductance antenna and a base film in the plasma processing chamber shown in FIG. 3.
• FIG. 4 is a cross-sectional view showing the positional relationship between a low inductance antenna and a base film in the plasma processing chamber shown in FIG. 3.
• 3 is a schematic diagram of an observation image of a cross section of a sample in Example 1.
• FIG. FIG. 13 is a schematic diagram of an observation image of a cross section of a sample in Comparative Example 3.
• An anti-reflection film X comprises a base film 10, an adhesive layer 21, and an anti-reflection layer 22, in this order in the thickness direction H.
• the anti-reflection film X extends in a direction (plane direction D) perpendicular to the thickness direction H.
• the anti-reflection film X is disposed, for example, on the outer surface of a display screen of a display device.
• the base film 10 side of the anti-reflection film X is bonded to the outer surface of the display device via a bonding material such as a transparent adhesive sheet. Examples of display devices include liquid crystal displays and organic EL displays.
• the anti-reflection layer 22 has a surface 22A on the side opposite the base film 10.
• the base film 10 includes a resin film 11 and a cured resin layer 12 in this order in the thickness direction H.
• the resin film 11 and the cured resin layer 12 are in contact with each other.
• the cured resin layer 12 forms the first surface 10a
• the resin film 11 forms the second surface 10b.
• the resin film 11 is an element that ensures the strength of the anti-reflection film X.
• the resin film 11 is, for example, a transparent resin film having flexibility.
• the material of the resin film 11 include polyester resin, polyolefin resin, cellulose resin, acrylic resin, polycarbonate resin, polyethersulfone resin, polyarylate resin, melamine resin, polyamide resin, polyimide resin, and polystyrene resin.
• the polyester resin include polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate.
• the polyolefin resin include polyethylene, polypropylene, and cycloolefin polymer (COP).
• the cellulose resin examples include triacetyl cellulose (TAC). These materials may be used alone or in combination of two or more. From the viewpoint of transparency and strength, the material of the resin film 11 is preferably at least one selected from the group consisting of polyester resin, polyolefin resin, and cellulose resin, and more preferably at least one selected from the group consisting of PET, COP, and TAC.
• TAC triacetyl cellulose
• the thickness of the resin film 11 is preferably 10 ⁇ m or more, more preferably 20 ⁇ m or more, even more preferably 30 ⁇ m or more, and is preferably 200 ⁇ m or less, more preferably 150 ⁇ m or less, even more preferably 100 ⁇ m or less.
• the thickness of the resin film 11 is equal to or greater than the above lower limit, the strength of the anti-reflection film X can be ensured.
• the thickness of the resin film 11 is equal to or less than the above upper limit, the handleability of the substrate film 10 in the roll-to-roll process described below can be ensured.
• the total light transmittance (JIS K 7375:2008) of the resin film 11 is preferably 80% or more, more preferably 90% or more, and even more preferably 95% or more, and is, for example, 100% or less.
• the total light transmittance of the resin film 11 is equal to or greater than the above lower limit, good transparency can be ensured in the anti-reflection film X.
• the cured resin layer 12 is a functional layer that contains a resin.
• the cured resin layer 12 is a cured product of a curable resin composition that contains a curable resin.
• An example of a functional layer is a hard coat layer.
• the hard coat layer is a layer that makes it difficult for scratches to form on the exposed surface (the upper surface in FIG. 1) of the anti-reflection layer 22.
• the curable resin examples include polyester resin, acrylic urethane resin, acrylic resin (excluding acrylic urethane resin), urethane resin (excluding acrylic urethane resin), amide resin, silicone resin, epoxy resin, and melamine resin. These curable resins may be used alone or in combination of two or more types. From the viewpoint of ensuring the hardness of the cured resin layer 12, the curable resin is preferably at least one selected from the group consisting of acrylic urethane resin and acrylic resin.
• the curable resin examples include ultraviolet-curable resins and thermosetting resins.
• the curable resin is preferably an ultraviolet-curable resin.
• the curable resin can be cured without being heated to a high temperature, which improves the manufacturing efficiency of the anti-reflection film X.
• the curable resin may also contain, for example, a reactive diluent as described in JP 2008-88309 A. Specifically, the resin may contain a polyfunctional (meth)acrylate.
• the cured resin layer 12 contains fewer inorganic oxide particles.
• materials for inorganic oxide particles include silica, alumina, titania, zirconia, calcium oxide, tin oxide, indium oxide, cadmium oxide, and antimony oxide.
• the inorganic oxide particle content of the cured resin layer 12 is preferably 20% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, even more preferably 1% by mass or less, even more preferably 0.5% by mass or less, even more preferably 0.2% by mass or less, even more preferably 0.1% by mass or less, and particularly preferably 0.0% by mass.
• the thickness of the cured resin layer 12 is preferably 1 ⁇ m or more, more preferably 3 ⁇ m or more, and even more preferably 5 ⁇ m or more, and is preferably 30 ⁇ m or less, more preferably 25 ⁇ m or less, and even more preferably 20 ⁇ m or less.
• the thickness of the cured resin layer 12 is equal to or greater than the above lower limit, the function of the cured resin layer 12 can be ensured.
• the cured resin layer 12 is a hard coat layer, the scratch resistance of the anti-reflection layer 22 can be ensured.
• the thickness of the cured resin layer 12 is equal to or less than the above upper limit, cracking of the cured resin layer 12 can be suppressed, and good transportability can be ensured in the roll-to-roll process.
• the total light transmittance (JIS K 7375:2008) of the substrate film 10 is preferably 80% or more, more preferably 90% or more, and even more preferably 95% or more, and is, for example, 100% or less.
• the total light transmittance of the substrate film 10 is equal to or greater than the above lower limit, good transparency can be ensured in the anti-reflection film X.
• the surface roughness Sa (arithmetic mean height based on ISO 25178-2:2012) of the first surface 10a of the substrate film 10 is preferably 1.0 nm or more, more preferably 1.2 nm or more, even more preferably 1.3 nm or more, and is preferably 4.0 nm or less, more preferably 3.0 nm or less, even more preferably 2.5 nm or less.
• the surface roughness Sa of the first surface 10a is equal to or greater than the above lower limit, the adhesion of the anti-reflection layer 22 to the substrate film 10 via the adhesion layer 21 is enhanced due to the anchor effect of the fine irregularities of the first surface 10a on the adhesion layer 21.
• Having the surface roughness Sa of the first surface 10a equal to or less than the above upper limit is suitable for suppressing a decrease in the scratch resistance of the surface 22A of the anti-reflection layer 22.
• the first surface 10a is, for example, a surface that has been plasma-treated.
• the plasma treatment is preferably an inductively coupled plasma treatment (oxygen-LAICP treatment) using an oxygen-containing gas, which is generated by applying high-frequency power to a low-inductance antenna.
• oxygen-LAICP treatment of the first surface 10a will be described in detail later with respect to the manufacturing method of the anti-reflection film X.
• the adhesion layer 21 is disposed on one surface of the substrate film 10 in the thickness direction H. Specifically, the adhesion layer 21 is disposed on the first surface 10a of the substrate film 10. The adhesion layer 21 is in contact with the substrate film 10.
• the adhesion layer 21 is a layer that enhances the adhesion of the anti-reflection layer 22 to the substrate film 10. Examples of materials for the adhesion layer 21 include metals such as silicon, indium, nickel, chromium, aluminum, tin, gold, silver, platinum, zinc, titanium, tungsten, zirconium, palladium, and niobium, alloys of two or more of these metals, and oxides of these metals.
• the material for the adhesion layer 21 is preferably indium tin oxide (ITO) or silicon oxide (SiOx).
• the silicon oxide used as the material for the adhesion layer 21 is preferably SiOx with a lower amount of oxygen than the stoichiometric composition, and more preferably SiOx with x between 1.2 and 1.95.
• the thickness of the adhesion layer 21 is preferably 1 nm or more, more preferably 2 nm or more, and even more preferably 3 nm or more, and is preferably 10 nm or less, more preferably 7 nm or less, and even more preferably 5 nm or less.
• the thickness of the adhesion layer 21 is equal to or greater than the above lower limit, the adhesion between the substrate film 10 and the anti-reflection layer 22 can be ensured.
• the thickness of the adhesion layer 21 is equal to or less than the above upper limit, the transparency of the adhesion layer 21 can be ensured.
• the anti-reflection layer 22 is disposed on one surface of the adhesion layer 21 in the thickness direction H.
• the anti-reflection layer 22 is in contact with the adhesion layer 21.
• the anti-reflection layer 22 is a layer that suppresses the reflection intensity of external light (anti-reflection properties).
• the antireflection layer 22 includes a high refractive index layer 22a, a low refractive index layer 22b, a high refractive index layer 22c, a low refractive index layer 22d, and an anti-fouling surface layer 22e, in this order from the adhesive layer 21 side in the thickness direction H.
• the antireflection layer 22 in this embodiment is an antireflection layer with an anti-fouling surface layer.
• the high refractive index layer 22a is in contact with the adhesive layer 21.
• the high refractive index layer 22a is in contact with the low refractive index layer 22b.
• the low refractive index layer 22b is in contact with the high refractive index layer 22c.
• the high refractive index layer 22c is in contact with the low refractive index layer 22d.
• the high refractive index layers 22a and 22c are layers with a relatively high refractive index
• the low refractive index layers 22b and 22d are layers with a relatively low refractive index.
• the intensity of the reflected light is attenuated by interference between the reflected light at multiple interfaces in the high refractive index layers 22a, 22c and the low refractive index layers 22b, 22d.
• Such interference can be achieved by adjusting the optical film thickness (the product of the film's refractive index and thickness) of each layer in the anti-reflection layer 22.
• the high refractive index layer 22a (first high refractive index layer) is made of a high refractive index material having a refractive index of preferably 1.9 or more at a wavelength of 550 nm.
• high refractive index materials include niobium oxide (Nb 2 O 5 ), titanium oxide, zirconium oxide, indium tin oxide (ITO), and antimony tin oxide (ATO).
• the high refractive index material is preferably niobium oxide (refractive index 2.33).
• the optical thickness of the high refractive index layer 22a is, for example, 20 nm or more and, for example, 55 nm or less.
• the low refractive index layer 22b (first low refractive index layer) is made of a low refractive index material having a refractive index of preferably 1.6 or less at a wavelength of 550 nm.
• low refractive index materials include silicon dioxide (SiO 2 ) and magnesium fluoride. From the viewpoint of achieving both a low refractive index and low absorption of visible light, the low refractive index material is preferably silicon dioxide (refractive index 1.46).
• the optical film thickness of the low refractive index layer 22b is, for example, 15 nm or more and, for example, 70 nm or less.
• the high refractive index layer 22c (second high refractive index layer) is made of a high refractive index material having a refractive index of preferably 1.9 or more at a wavelength of 550 nm.
• high refractive index materials include the materials described above for the high refractive index layer 22a, and niobium oxide is preferred.
• the optical film thickness of the high refractive index layer 22c is, for example, 60 nm or more and, for example, 330 nm or less.
• the low refractive index layer 22d (second low refractive index layer) is made of a low refractive index material whose refractive index at a wavelength of 550 nm is preferably 1.6 or less.
• low refractive index materials include the materials described above for the low refractive index layer 22b, and silicon dioxide is preferred.
• the optical film thickness of the low refractive index layer 22d is, for example, 100 nm or more and, for example, 160 nm or less.
• the total thickness of the anti-reflection layer 22 from the high refractive index layer 22a to the low refractive index layer 22d is preferably 180 nm or more, more preferably 200 nm or more, and even more preferably 220 nm or more, and is preferably 320 nm or less, more preferably 280 nm or less, and even more preferably 250 nm or less.
• the total thickness of the anti-reflection layer 22 is the sum of the thicknesses of the high refractive index layers 22a, 22c and the low refractive index layers 22b, 22d.
• the anti-reflection layer 22 can ensure the function of attenuating the reflected light intensity.
• the total thickness of the anti-reflection layer 22 is equal to or less than the upper limit, cracking of the anti-reflection layer 22 can be suppressed.
• the anti-soiling surface layer 22e is a layer having an anti-soiling function.
• the anti-soiling surface layer 22e is disposed on the low refractive index layer 22d.
• the anti-soiling function of the anti-soiling surface layer 22e includes a function of suppressing adhesion of contaminants such as hand oils to the exposed surface of the film when the anti-reflection film X is in use, and a function of making it easier to remove adhered contaminants.
• Examples of the material for the stain-resistant surface layer 22e include organic fluorine compounds.
• an alkoxysilane compound having a perfluoropolyether group is preferably used.
• an alkoxysilane compound having a perfluoropolyether group for example, a compound represented by the following general formula (1) is used.
• R1 represents a linear or branched fluorinated alkyl group (having, for example, 1 to 20 carbon atoms) in which one or more hydrogen atoms in the alkyl group are substituted with fluorine atoms, and preferably represents a perfluoroalkyl group in which all of the hydrogen atoms in the alkyl group are substituted with fluorine atoms.
• R 2 represents a structure containing at least one repeating structure of a perfluoropolyether (PFPE) group, and preferably represents a structure containing two repeating structures of a PFPE group.
• PFPE perfluoropolyether
• Examples of the repeating structure of a PFPE group include a repeating structure of a linear PFPE group and a repeating structure of a branched PFPE group.
• Examples of the repeating structure of a linear PFPE group include a structure represented by -(OC n F 2n ) p - (n represents an integer of 1 or more and 20 or less, and p represents an integer of 1 or more and 50 or less; the same applies below).
• Examples of the repeating structure of a branched PFPE group include a structure represented by -(OC(CF 3 ) 2 ) p - and a structure represented by -(OCF 2 CF(CF 3 )CF 2 ) p -.
• the repeating structure of the PFPE group preferably includes a repeating structure of a linear PFPE group, more preferably --(OCF 2 ) p -- and --(OC 2 F 4 ) p --.
• R3 represents an alkyl group having 1 to 4 carbon atoms, and preferably represents a methyl group.
• X represents an ether group, a carbonyl group, an amino group, or an amide group, and preferably represents an ether group.
• n represents an integer of 1 or more. Furthermore, m represents an integer of preferably 20 or less, more preferably 10 or less, and even more preferably 5 or less.
• alkoxysilane compounds having a perfluoropolyether group the compound shown in the following general formula (2) is preferably used.
• q represents an integer of 1 or more and 50 or less
• r represents an integer of 1 or more and 50 or less
• alkoxysilane compounds having perfluoropolyether groups may be used alone or in combination of two or more types.
• the anti-soiling surface layer 22e is a film (dry coating film) formed by a dry coating method. Dry coating methods include sputtering, vacuum deposition, and CVD.
• the anti-soiling surface layer 22e is preferably a dry coating film, and more preferably a vacuum deposition film.
• the configuration in which the material of the anti-soiling surface layer 22e contains an alkoxysilane compound having a perfluoropolyether group and the anti-soiling surface layer 22e is a dry coating film (preferably a vacuum deposition film) is suitable for ensuring high adhesion of the anti-soiling surface layer 22e to the base, and therefore is suitable for ensuring peel resistance of the anti-soiling surface layer 22e.
• the high peel resistance of the anti-soiling surface layer 22e helps maintain the anti-soiling function of the anti-soiling surface layer 22e.
• the thickness of the antifouling surface layer 22e is preferably 1 nm or more, more preferably 3 nm or more, even more preferably 5 nm or more, particularly preferably 7 nm or more, and is preferably 25 nm or less, more preferably 20 nm or less, and even more preferably 18 nm or less.
• the anti-reflection layer 22 has a surface 22A (surface of the antifouling surface layer 22e) on the side opposite to the substrate film 10.
• the surface roughness Sa (arithmetic mean height based on ISO 25178-2:2012) of the surface 22A is 4.5 nm or less, preferably 3.0 nm or less, more preferably 2.5 nm or less, even more preferably 2.0 nm or less, and even more preferably 1.8 nm or less.
• the surface roughness Sa of the surface 22A is equal to or less than the upper limit, light scattering on the surface 22A can be suppressed.
• the surface roughness Sa of the surface 22A is preferably 1.0 nm or more, more preferably 1.3 nm or more, even more preferably 1.5 nm or more, even more preferably more than 1.5, and even more preferably 1.6 nm or more.
• the surface roughness Sa of the surface 22A being equal to or more than the lower limit is suitable for reducing frictional force and ensuring good slipperiness on the surface 22A.
• the method for measuring the surface roughness Sa is as described below in the examples.
• the interface between the base film 10 and the adhesive layer 21 has fine irregularities (not shown).
• the interface between two adjacent layers in the anti-reflection layer 22 also has fine irregularities (not shown).
• Microscopic irregularities are, for example, irregularities on the order of nanometers.
• the ratio (L2/L1) of the second interface length L2 at the interface (second interface) between the high refractive index layer 22a and the low refractive index layer 22b to the first interface length L1 at the interface (first interface) between the base film 10 and the adhesive layer 21 is 1.10 or more, preferably 1.15 or more, more preferably 1.17 or more, and even more preferably 1.20 or more.
• the first interface length L1 is the length of the first interface included in a predetermined range in the surface direction D in one cross-sectional view.
• the second interface length L2 is the length of the second interface included in the same range in the surface direction D in the same cross-sectional view.
• the method for measuring the first interface length L1 and the second interface length L2 is as described later in the examples.
• the ratio (L2/L1) is equal to or greater than the lower limit, the adhesion of the antireflection layer 22 in the antireflection film X can be increased by the anchor effect.
• the ratio (L2/L1) is preferably equal to or less than 2.00, more preferably equal to or less than 1.50, and more preferably equal to or less than 1.30.
• the ratio (L2/L1) is equal to or less than the upper limit, the surface roughness Sa of the surface 22A of the antireflection layer 22 can be suppressed, and light scattering at the surface 22A can be suppressed.
• methods for adjusting the ratio (L2/L1) include adjusting the conditions of the plasma treatment for the first surface 10a of the substrate film 10 and adding an appropriate amount of particles to the cured resin layer 12.
• the total reflectance of light having a wavelength of 380 nm to 780 nm irradiated from a standard light source D65 on the antireflection layer 22 side of the antireflection film X is preferably 0.40% or less, more preferably 0.36% or less, even more preferably 0.33% or less, and may be, for example, 0.00% or more.
• the total reflectance of the antireflection film X is equal to or less than the upper limit value, the antireflection properties of the antireflection film X can be ensured. This makes it possible to suppress reflection of external light and glare of images on the display screen on which the antireflection film X is placed in a display device.
• the method for measuring the total reflectance is as described below in the examples.
• the moisture permeability of the anti-reflection film X is preferably 100 g/ m2 ⁇ 24h or more, more preferably 200 g/ m2 ⁇ 24h or more, even more preferably 300 g/ m2 ⁇ 24h or more, even more preferably 330 g/ m2 ⁇ 24h or more, and also preferably 500 g/ m2 ⁇ 24h or less, more preferably 400 g/ m2 ⁇ 24h or less, and even more preferably 380 g/ m2 ⁇ 24h or less.
• the moisture permeability is measured as described later in the examples.
• the moisture permeability of the anti-reflection film X is the above-mentioned lower limit or more, moisture contained in the polarizer in the polarizing plate is easily released to the outside through the anti-reflection film X in a heating environment after the anti-reflection film X is bonded to the polarizing plate, so that the deterioration of the polarizer caused by moisture can be suppressed.
• the moisture permeability of the anti-reflection film X is the above-mentioned upper limit or less, the deterioration of the polarizing plate can be suppressed in a humid environment after the anti-reflection film X is bonded to the polarizing plate.
• An example of a method for adjusting the moisture permeability is adjusting the pressure (atmospheric pressure) in a film formation chamber during sputtering film formation, which will be described later.
• the peeling rate of the antireflective layer 22 of the antireflective film X in the second test described below after the first test (accelerated weather resistance test) described below is preferably less than 20%, more preferably 15% or less, even more preferably 10% or less, and even more preferably less than 10%, from the viewpoint of ensuring the adhesion of the antireflective layer 22. More specifically, the methods of the first and second tests are as described later in the examples.
• the peeling rate of the antireflective layer 22 is equal to or less than the upper limit value, in practical use of the antireflective film X, the deterioration of the antireflective properties of the antireflective film X due to peeling of the antireflective layer 22 can be suppressed.
• Test 1 First, the substrate film 10 side of the antireflection film X is fixed to a glass plate. Next, the antireflection layer 22 of the antireflection film X on the glass plate is irradiated with light for 32.5 hours under conditions of a temperature of 85° C., a relative humidity of 45%, and an irradiation intensity (integrated illuminance from 290 nm to 450 nm) of 150 mW/ cm2 .
• Test 2 First, eleven parallel first incisions (2 mm apart) extending linearly in a first direction and eleven parallel second incisions (2 mm apart) extending linearly in a second direction perpendicular to the first direction are formed on the anti-reflection layer 22 and the adhesive layer 21 of the anti-reflection film X on the glass plate after the first test by a cutter knife, and 100 squares are formed by the first and second incisions.
• isopropyl alcohol is continuously dropped at 2 mL/min on the area of the 100 squares in the anti-reflection film X, while a polyester wiper is slid under the conditions of a wiper contact surface of 20 mm x 20 mm, a load of 1.5 kg/20 mm, a sliding speed of 50 mm/sec, and 1000 reciprocations.
• the number of squares in which peeling of 1 mm2 or more has occurred is counted among the 100 squares.
• the count number is divided by 100 to calculate the peeling rate (%).
• the surface roughness Sa of the surface 22A of the anti-reflection layer 22 is 4.5 nm or less, and in a cross-sectional view in the thickness direction H, the ratio (L2/L1) of the second interface length L2 at the interface between the high refractive index layer 22a and the low refractive index layer 22b to the first interface length L1 at the interface between the substrate film 10 and the adhesive layer 21 is 1.10 or more.
• the surface roughness Sa of the surface 22A is 4.5 nm or less, so that scattering of light incident on the anti-reflection film X at the surface 22A can be suppressed.
• the above ratio (L2/L1) of the first interface length L1 and the second interface length L2 being 1.10 or more can be achieved, for example, by roughening the surface of a substrate film (substrate film 10 in this embodiment) that does not substantially contain particles on its surface, and then forming an anti-reflection layer on the surface via a predetermined adhesive layer.
• the anti-reflection layer 22 is formed on the substrate film 10 via the adhesion layer 21, and the above ratio of the first and second interface lengths is 1.10 or more, so that the adhesion of the anti-reflection layer 22 to the substrate film 10 can be ensured.
• the substrate film 10 does not contain particles, scattering of light incident on the anti-reflection film X caused by particles in the substrate film 10 can be suppressed.
• Such an anti-reflection film X can provide a good anti-reflection effect while ensuring the adhesion of the anti-reflection layer 22 to the substrate film 10.
• FIGS. 2A to 2C show an example of a method for manufacturing an anti-reflection film X.
• This manufacturing method includes a cured resin layer forming process (FIG. 2A), a plasma treatment process, and a film forming process (FIGS. 2B and 2C).
• a cured resin layer 12 is formed on a long resin film 11. This results in a substrate film 10.
• the cured resin layer 12 can be formed by applying the above-mentioned curable resin composition to the resin film 11 to form a coating film, and then curing the coating film.
• the curable resin composition may contain other components other than the above-mentioned curable resin as necessary. Examples of the other components include a solvent and a leveling agent. Examples of the solvent include butyl acetate, ethyl acetate, toluene, and cyclopentanone.
• the curable resin composition when the curable resin composition contains an ultraviolet-curable resin as the curable resin group, the curable resin composition preferably contains a photopolymerization initiator.
• the curable resin composition when the curable resin composition contains a thermosetting resin as the curable resin, the curable resin composition preferably contains a thermal polymerization initiator.
• the coating on the resin film 11 is dried after the curable resin composition is applied.
• the drying temperature is, for example, 50°C or higher and, for example, 120°C or lower.
• the drying time is, for example, 10 seconds or higher and, for example, 10 minutes or shorter.
• the coating film on the resin film 11 is cured by ultraviolet irradiation.
• the light source for ultraviolet irradiation include a high-pressure mercury lamp and an LED light.
• the cumulative irradiation amount of the ultraviolet light is, for example, 100 mJ/ cm2 or more and, for example, 500 mJ/cm2 or less.
• the coating on the resin film 11 is cured by heating.
• the heating temperature is, for example, 100°C or higher and, for example, 150°C or lower.
• the heating time is, for example, 10 seconds or higher and, for example, 10 minutes or shorter.
• a long base film 10 can be produced.
• a roll of the long base film 10 is prepared. Specifically, the base film 10 is wound so that the first surface 10a of the base film 10 faces inward in the radial direction of the roll.
• the device Y shown in FIG. 3 is an example of a device for carrying out the plasma treatment process and the film formation process.
• the device Y includes a payout chamber R1, a winding chamber R2, a connection chamber C1, a plasma treatment chamber C2, a connection chamber C3, a film formation chamber C4 (first film formation chamber), a connection chamber C5, and a film formation chamber C6 (second film formation chamber).
• the unwinding chamber R1 is equipped with a unwinding roller 51 for unwinding the work film W.
• a roll of a long base film 10 is attached to the unwinding roller 51 as the work film W.
• a predetermined number of guide rollers G for guiding the work film W are provided within the unwinding chamber R1.
• the winding chamber R2 is equipped with a winding roller 52 for winding up the work film W.
• a predetermined number of guide rollers G for guiding the work film W are provided within the winding chamber R2.
• connection chamber C1 is positioned next to the unwinding chamber R1 in the running direction of the work film W, and is positioned before the plasma processing chamber C2.
• a predetermined number of guide rollers G for guiding the work film W are provided inside the connection chamber C1.
• the connection chamber C1 is connected to a vacuum pump (not shown), and is configured so that the pressure inside the chamber can be adjusted.
• the pressure inside the connection chamber C1 is maintained at a predetermined pressure between the pressure inside the unwinding chamber R1 and the pressure inside the plasma processing chamber C2. This ensures a pressure difference between the unwinding chamber R1 and the plasma processing chamber C2.
• the plasma processing chamber C2 is disposed between the connection chamber C1 and the connection chamber C3 in the running direction of the workpiece film W. In the plasma processing chamber C2, the plasma processing process is carried out as described below.
• a first line L1 equipped with a flow control valve for introducing gas into the chamber is connected to the plasma processing chamber C2.
• the plasma processing chamber C2 is equipped with a plurality of low inductance antennas (LA) 71.
• the low inductance antenna means an antenna that has a low inductance of 7.5 ⁇ H or less and is capable of generating inductively coupled plasma by application of high frequency power.
• the LA71 is supported by a mounting fixture 72 and covered by a cover block 73 (omitted in FIG. 4) as shown in FIGS. 4 and 5, and is placed inside the plasma processing chamber C2 (an example is shown in which the number of LA71 is four).
• the multiple LAs 71 are aligned in the running direction of the base film 10 and in the direction perpendicular to the running direction (the width direction of the base film 10).
• the fixture 72 is a vacuum flange. As shown in FIG. 5, the LAs 71 are fixed to the fixture 72 via a field through 74. As shown in FIG. 4, the fixture 72 is attached to an opening 75 provided in the wall of the plasma processing chamber C2. Specifically, the fixture 72 is attached to the opening 75 with a seal member (not shown) sandwiched between the wall of the plasma processing chamber C2 and the fixture 72.
• the LAs 71 are electrically connected to a high-frequency power source (RF power source) outside the plasma processing chamber C2 via an impedance matching device.
• RF power source high-frequency power source
• Such LAs 71 are formed of a conductor. Examples of conductors include copper and silver, and copper is preferable.
• the LAs 71 may be covered with an insulator. Examples of insulators include glass and quartz.
• the cover block 73 comprises a block body 73A and multiple partition plates 73B.
• the block body 73A has multiple storage spaces 73a.
• One LA 71 is stored in each storage space 73a.
• the partition plates 73B are arranged to close the storage spaces 73a.
• the storage spaces 73a are sealed spaces.
• the block body 73A is made of, for example, aluminum.
• An example of the aluminum is aluminum A5052.
• the partition plates 73B are made of an insulating material.
• An example of the insulating material is quartz and glass.
• the separation distance d' (shown in Figure 5) between the substrate film 10 running in the plasma processing chamber C2 and the cover block 73 is, for example, 50 to 200 mm.
• Such a cover block 73 helps to avoid damage and contamination of the LA71 due to plasma treatment without excessively reducing the plasma conversion efficiency due to the power applied to the LA71, and also helps to suppress damage to the substrate film 10 being plasma treated.
• the LA71 has an open loop shape in this embodiment.
• the open loop shape of the LA71 is advantageous in lowering the inductance of the LA71. Therefore, the open loop shape of the LA71 can suppress an increase in voltage due to an increase in the power applied to the LA71. This can suppress abnormal discharge during the plasma treatment described below. The suppression of abnormal discharge can suppress damage to the base film 10 being plasma treated.
• the LA71 has a U-shape with two free ends. For each LA71, the two free ends are fixed to the fixture 72 so as to be aligned in the width direction of the base film 10.
• the LA71 has an extension 71a on the opposite side to the two free ends.
• the extension 71a extends parallel to the base film 10 passing through the plasma processing chamber C2.
• the extension 71a extends in the width direction of the base film 10.
• Each extension 71a may extend in the running direction of the base film 10 (four LA71 may be arranged in this manner).
• the length of the extension 71a is, for example, 50 to 150 mm (FIG. 4 illustrates an example in which the length of the extension 71a is the same as the maximum length d2 of the LA71 described below).
• the LA71 may have a coil shape instead of an open loop shape.
• the LA 71 extends from the fixture 72 toward the base film 10.
• the LA 71 preferably extends perpendicularly to the fixture 72.
• the extension length d 1 of the LA 71 from the fixture 72 is, for example, 30 to 150 mm.
• the maximum length d 2 of the LA 71 in the surface direction of the base film 10 is, for example, 50 to 150 mm.
• the separation distance d 3 (shown in FIG. 5 ) between the LA 71 and the base film 10 is, for example, 50 to 200 mm.
• the extension length d 1 and the separation distance d 3 are preferably the same.
• the ratio (d 3 /d 1 ) of the separation distance d 3 to the extension length d 1 is, for example, 0.5 to 3.5.
• the number (number of rows) of the LAs 71 spaced apart in the running direction of the base film 10 may be 1, 2, or 3, or may be 4 or more if necessary, depending on the running speed (i.e., plasma treatment time) of the base film 10.
• the center-to-center distance d 4 between adjacent LAs 71 is, for example, 100 to 500 mm.
• the center-to-center distance d 5 between adjacent LAs 71 is, for example, 200 to 500 mm.
• the center-to-center distance d 4 and the center-to-center distance d 5 are preferably the same.
• the ratio (d 5 /d 4 ) of the center-to-center distance d 5 to the center-to-center distance d 4 is, for example, 0.5 to 2.0.
• the center points of the extensions 71a of the four LAs 71 preferably form a square with the vertices. High density plasma can be generated by such a set of LAs 71.
• the LAs 71 for example, a high frequency antenna for plasma generation described in JP 2013-258153 A may be used.
• the plasma processing chamber C2 further includes a transport roller 53.
• the transport roller 53 is a main guide roller for transporting the workpiece film W within the plasma processing chamber C2.
• the transport roller 53 has a temperature adjustment function that allows the workpiece film W to be heated or cooled.
• the transport roller 53 is a transport roller with a temperature adjustment function.
• the transport roller 53 transports the base film 10 while contacting the second surface 10b of the base film 10.
• the LA 71 is disposed opposite the transport roller 53.
• the transport roller 53 with a temperature control function that contacts the base film 10 can perform plasma treatment on the base film 10 while cooling or heating the base film 10.
• connection chamber C3 is located next to the plasma processing chamber C2 in the running direction of the work film W and before the film formation chamber C4.
• a predetermined number of guide rollers G for guiding the work film W are provided inside the connection chamber C3.
• the connection chamber C3 is connected to a vacuum pump (not shown) and is configured so that the pressure inside the chamber can be adjusted.
• the pressure inside the connection chamber C3 is maintained at a predetermined pressure between the pressure inside the plasma processing chamber C2 and the pressure inside the film formation chamber C4. This ensures a pressure difference between the plasma processing chamber C2 and the film formation chamber C4.
• the film-forming chamber C4 is disposed next to the connection chamber C3 in the running direction of the work film W.
• the film-forming chamber C4 is also connected to a vacuum pump (not shown) and is configured so that the interior of the chamber can be adjusted to a predetermined vacuum level.
• the film-forming process from the high refractive index layer 22a to the low refractive index layer 22d is carried out as described below.
• the film-forming chamber C4 is a sputtering film-forming chamber.
• the film-forming chamber C4 includes a film-forming roller 54 and a plurality of sputtering chambers 60 (sputtering chambers 60a to 60e) (a case where the number of sputtering chambers 60 is 5 is illustrated as an example).
• the film-forming roller 54 is a main guide roller for transporting the workpiece film W within the film-forming chamber C4.
• the film-forming roller 54 has a temperature adjustment function that can heat or cool the workpiece film W.
• the sputtering chamber 60 is a partitioned space within the film-forming chamber C4.
• the plurality of sputtering chambers 60 are arranged along the circumferential direction of the film-forming roller 54.
• Each sputtering chamber 60 opens toward the film-forming roller 54.
• a cathode 61 is provided within the sputtering chamber 60.
• a target (not illustrated) is arranged on the cathode 61 as a film-forming material supply material. The target is arranged on the target so as to face the film-forming roller 54.
• Each sputtering chamber 60 is provided with a power supply (not shown) for applying a voltage to the target to generate a glow discharge.
• Examples of power supplies include DC power supplies, AC power supplies, MF power supplies, RF power supplies, and MF-AC power supplies.
• MF-AC power supplies refer to AC power supplies with a frequency band of several kHz to several MHz.
• Each sputtering chamber 60 is connected to a required number of second lines (not shown) equipped with flow rate control valves for introducing gas into the chamber.
• a predetermined number of guide rollers G for guiding the workpiece film W are provided in the deposition chamber C4.
• connection chamber C5 is disposed between the connection chamber C4 and the film forming chamber C6 in the running direction of the work film W.
• a predetermined number of guide rollers G for guiding the work film W are provided within the connection chamber C5.
• the film-forming chamber C6 is disposed between the connection chamber C5 and the winding chamber R2 in the running direction of the workpiece film W.
• the film-forming chamber C6 is a vacuum deposition chamber.
• the film-forming chamber C6 includes a material holding section 62 and a deposition amount adjustment valve (not shown) whose opening is controllable.
• the film-forming chamber C6 is connected to a vacuum pump (not shown) so that the pressure inside the chamber can be adjusted.
• a predetermined number of guide rollers G are provided in the film-forming chamber C6 for guiding the workpiece film W. In the film-forming chamber C6, the film-forming step of the stain-resistant surface layer 22e is carried out.
• a film-forming material supply (not shown) is arranged in the material holding section 62 so as to face the workpiece film W being transported in the film-forming chamber C6.
• the material holding section 62 may be provided with a built-in resistance heating means, a built-in high-frequency induction heating means, or an electron beam heating means as a means for heating the film-forming material supply.
• the above-described device Y performs a plasma treatment process and a film formation process in sequence. Specifically, the process is as follows.
• the work film W is unwound from the unwinding chamber R1. After being unwound from the unwinding chamber R1, the work film W passes through the connection chamber C1, the plasma treatment chamber C2, the connection chamber C3, the film forming chamber C4, the connection chamber C5, and the film forming chamber C6 in sequence, and is wound up in the winding chamber R2.
• the running speed of the work film W is, for example, 0.5 m/min or more, and, for example, 5 m/min or less.
• the series of lines from the unwinding chamber R1 to the winding chamber R2 is not opened to the atmosphere along the way, and the process is carried out in the line under a reduced pressure atmosphere.
• the reduced pressure atmosphere is preferably under vacuum. Under vacuum preferably means a reduced pressure atmosphere of 7 Pa or less.
• the plasma treatment process is carried out in the plasma treatment chamber C2.
• plasma treatment is performed on the first surface 10a of the base film 10 in a reduced pressure atmosphere in the plasma treatment chamber C2 (chamber).
• the plasma treatment is a treatment using inductively coupled plasma of an oxygen-containing gas (oxygen-LAICP treatment) that is generated by applying high-frequency power to the LA71. Specifically, it is as follows.
• oxygen is supplied into the plasma processing chamber C2 through the first line L1.
• an inert gas may be supplied into the plasma processing chamber C2.
• inert gas include argon, krypton, and xenon.
• the gas in the plasma processing chamber C2 may contain gases other than the inert gas. Examples of other gases include oxygen, nitrogen, hydrogen, and water vapor.
• the oxygen concentration of the gas (oxygen-containing gas) in the plasma processing chamber C2 is preferably 30% by volume or more, more preferably 50% by volume or more, even more preferably 80% by volume or more, even more preferably 90% by volume or more, even more preferably 95% by volume or more, and particularly preferably 100% by volume.
• oxygen concentration is equal to or more than the lower limit
• high-density oxygen plasma can be generated. This is useful for forming fine irregularities on the nanometer order on the first surface 10a of the substrate film 10 and for highly activating the first surface 10a by cleaning it.
• the pressure (first pressure) in the plasma processing chamber C2 during plasma processing is preferably 0.1 Pa or more, more preferably 0.2 Pa or more, even more preferably 0.3 Pa or more, and is preferably 7 Pa or less, more preferably 5 Pa or less, and even more preferably 3 Pa or less.
• first pressure is equal to or greater than the lower limit
• a plasma environment of sufficient density for surface modification processing of the first surface 10a of the substrate film 10 can be formed in the plasma processing chamber C2.
• the first pressure is equal to or less than the upper limit, thermal damage to the first surface 10a caused by excessively high-density plasma can be suppressed in the plasma processing, and excessive roughening of the first surface 10a can be suppressed. Suppression of excessive roughening helps to suppress a decrease in the mechanical strength of the first surface 10a.
• the first pressure can be adjusted by the amount of oxygen gas supplied into the plasma processing chamber C2.
• the frequency of the high frequency power applied to the LA71 during plasma treatment is preferably 1 MHz or more, more preferably 5 MHz or more, even more preferably 10 MHz or more, and also preferably 100 MHz or less, more preferably 80 MHz or less, and even more preferably 60 MHz or less.
• the frequency is equal to or greater than the lower limit, the plasma discharge can be stabilized while increasing the plasma current density during plasma treatment.
• the antenna potential can be suppressed, and therefore damage to the substrate film 10 caused by the plasma can be suppressed.
• the high frequency power is preferably 0.1 kW or more, more preferably 0.3 kW or more, even more preferably 1.0 kW or more, and is preferably 10 kW or less, more preferably 8 kW or less, and even more preferably 6 kW or less.
• the high frequency power is equal to or greater than the lower limit, a high density plasma environment can be formed in the plasma treatment chamber C2 during plasma treatment using inductively coupled plasma.
• the high frequency power is equal to or less than the upper limit, excessive damage to the substrate caused by the plasma can be suppressed.
• the plasma current density at the intermediate position between the LA 71 and the base film 10 is preferably 1.0 mA/cm3 or more , more preferably 2.0 mA/ cm3 or more, even more preferably 3.0 mA/ cm3 or more, and preferably 10 mA/cm3 or less , more preferably 8 mA/cm3 or less, even more preferably 4 mA/cm3 or less .
• the inductively coupled plasma treatment using a low inductance antenna can achieve a higher plasma current density (for example, a plasma density about 100 times higher) than the capacitively coupled plasma treatment described above.
• Methods for adjusting the plasma current density include, for example, adjusting the amount of oxygen gas introduced into the plasma processing chamber C2, adjusting the frequency of the high frequency power in the high frequency power supply, and adjusting the magnitude of the applied power.
• an adhesion layer 21 and an inorganic layer 22 are formed in sequence on the first surface 10a of the substrate film 10 by a sputtering method in a reduced pressure atmosphere.
• the reduced pressure atmosphere is preferably a vacuum.
• a sputtering gas (inert gas) is introduced into each sputtering chamber 60 via a second line, while a negative voltage is applied to a target (film-forming material) placed on a cathode 61 in the sputtering chamber 60.
• a glow discharge to ionize gas atoms, and the gas ions collide with the target surface at high speed, ejecting the target material from the target surface, which is then deposited on the workpiece film W.
• sputtering gases include argon, krypton, and xenon.
• the sputtering method may be a reactive sputtering method.
• oxygen a reactive gas
• the oxygen is introduced into the sputtering chamber 60 via another second line.
• the target is, for example, a metal in the metal oxide that forms each layer.
• the pressure (second pressure) in the sputtering chamber 60 is, for example, 0.1 to 5.0 Pa depending on the type of layer to be formed.
• the film formation temperature (the temperature of the workpiece film W, which is adjusted by the film formation roller 54) is, for example, -10°C to 150°C.
• an adhesive layer 21 is formed on the substrate film 10 by a sputtering method in the sputtering chamber 60a.
• an ITO layer is formed as the adhesive layer 21
• an ITO target is used as the target placed on the cathode 61 in the sputtering chamber 60a.
• reactive sputtering is performed while introducing argon and oxygen into the sputtering chamber 60a (reactive sputtering is also performed in the following sputtering methods in the sputtering chambers 60b to 60e).
• a high refractive index layer 22a is formed on the adhesive layer 21 by a sputtering method in the sputtering chamber 60b.
• a Nb 2 O 5 layer is used as a target placed on the cathode 61 in the sputtering chamber 60b.
• a low refractive index layer 22b is formed on the high refractive index layer 22a by a sputtering method in the sputtering chamber 60c.
• a Si target is used as a target placed on the cathode 61 in the sputtering chamber 60c.
• the high refractive index layer 22c is formed on the low refractive index layer 22b by sputtering in the sputtering chamber 60d.
• a Nb target is used as a target placed on the cathode 61 in the sputtering chamber 60d.
• a low refractive index layer 22d is formed on the high refractive index layer 22c by sputtering in the sputtering chamber 60e.
• a Si target is used as a target placed on the cathode 61 in the sputtering chamber 60e.
• the anti-stain surface layer 22e is further formed in the film formation chamber C6.
• the anti-stain surface layer 22e is formed on the low refractive index layer 22d of the workpiece film W in the film formation chamber C6 by vacuum deposition, which is a dry coating method.
• vacuum deposition which is a dry coating method.
• the anti-reflection film X serving as the work film W reaches the winding chamber R2 and is wound up by the winding roller 52.
• the anti-reflection layer 22 of the anti-reflection film X may not have the above-mentioned anti-soiling surface layer 22e. In that case, the surface of the low refractive index layer 22d opposite the substrate film 10 becomes the surface 22A of the anti-reflection layer 22.
• An anti-reflection film X that does not have the anti-soiling surface layer 22e can be manufactured by not performing the step in the film-forming chamber C6 in the above-mentioned manufacturing process of the anti-reflection film X.
• Example 1 The anti-reflection film of Example 1 was produced by carrying out the following steps in sequence.
• a hard coat layer was formed on one side of a triacetyl cellulose (TAC) film as a resin film to prepare a substrate film (preparation step).
• TAC triacetyl cellulose
• the solid content concentration of the mixed solution was adjusted to 36% by mass by adding a mixed solvent of cyclopentanone (CPN) and propylene glycol monomethyl ether (PGM) (mass ratio of CPN to PGM is 45:55).
• CPN cyclopentanone
• PGM propylene glycol monomethyl ether
• a long TAC film product name "KC4UY", thickness 40 ⁇ m, manufactured by Konica Minolta Advanced Layer
• a first resin composition was applied to one side of the TAC film to form a coating film.
• this coating film was dried by heating and then cured by ultraviolet irradiation.
• HC hard coat
• the heating temperature was 90° C., and the heating time was 1 minute.
• a high-pressure mercury lamp was used as a light source, and the coating film was irradiated with ultraviolet light having a wavelength of 365 nm, and the cumulative irradiation amount was 300 mJ/cm 2. In this manner, a TAC film with an HC layer was prepared as a substrate film.
• the first apparatus includes a payout chamber, a plasma treatment chamber (first plasma treatment), a first film formation chamber, a second film formation chamber, and a winding chamber.
• the payout chamber, the plasma treatment chamber, the first film formation chamber, the second film formation chamber, and the winding chamber are arranged in this order and communicate with each other.
• the payout chamber includes a payout roller. The above-mentioned roll of base film was set on the payout roller as the work film.
• the plasma treatment chamber includes a temperature-adjusting transport roller (transport roller 53 in FIG. 3) and four low-inductance antennas (LA71 in FIG. 4 and FIG. 5) covered with a cover block (cover block 73 in FIG. 5) as shown in FIG. 4 and FIG. 5.
• Each low inductance antenna has an extension (extension 71a in FIG. 4) parallel to the base film.
• the extension length d 1 is 88 mm
• the maximum length d 2 (length of the extension) is 100 mm
• the separation distance d 3 is 112 mm
• the center distance d 4 is 290 mm
• the center distance d 5 is 280 mm (FIGS. 4 and 5).
• the first film forming chamber is a sputtering film forming chamber, and includes a film forming roller (film forming roller 54 in FIG. 3) and first to fifth sputtering chambers (sputtering chambers 60a to 60e in FIG. 3). Each sputtering chamber is a partitioned space within the first film-forming chamber. The first to fifth sputtering chambers are arranged in this order along the circumferential direction of the film-forming roller in the running direction of the base film.
• Each sputtering chamber is equipped with a cathode arranged opposite the film-forming roller.
• a required number of second lines (not shown) equipped with flow rate control valves for introducing gas into the chamber are connected to each sputtering chamber.
• the second film-forming chamber is a vacuum deposition chamber and is equipped with a material holding section (material holding section 62 in FIG. 3).
• the winding chamber is equipped with a winding roller.
• the HC surface (first surface) of the base film was plasma treated in the plasma treatment chamber (plasma treatment process).
• the running speed of the base film was 1.0 m/min.
• the temperature of the temperature-controlled transport roller was -8°C.
• the plasma treatment conditions were as follows:
• the inside of the plasma processing chamber was evacuated until the ultimate vacuum level in the plasma processing chamber reached 1.0 ⁇ 10 ⁇ 4 Pa, after which oxygen was introduced into the plasma processing chamber until the pressure in the plasma processing chamber reached 1.5 Pa.
• a high-frequency power of 2 kW was applied to the four low-inductance antennas by a high-frequency power source to form an inductively coupled plasma of an oxygen-containing gas around the antennas (the surface of the HC layer of the substrate film was treated with this plasma).
• the plasma current density at the midpoint between the low-inductance antennas and the substrate film was 1.3 mA/ cm3 .
• the plasma current density was measured by a Langmuir probe for plasma measurement.
• an adhesive layer, a first high refractive index layer, a first low refractive index layer, a second high refractive index layer, and a second low refractive index layer were successively formed on the substrate film after the plasma treatment.
• an adhesive layer was formed on the HC layer of the substrate film in the first sputtering chamber, a first high refractive index layer was formed on the adhesive layer in the second sputtering chamber, a first low refractive index layer was formed on the first high refractive index layer in the third sputtering chamber, a second high refractive index layer was formed on the first low refractive index layer in the fourth sputtering chamber, and a second low refractive index layer was formed on the second high refractive index layer in the fifth sputtering chamber.
• the film-forming temperature (temperature of the film-forming roll) was -8°C. More specifically, it is as follows.
• the first sputtering chamber a 4 nm thick ITO layer was formed as an adhesive layer by reactive sputtering (adhesion layer forming process).
• the first film forming chamber was evacuated to an ultimate vacuum of 1.0 ⁇ 10 ⁇ 4 Pa, and then argon as an inert gas and oxygen as a reactive gas were introduced into the first sputtering chamber, and the pressure in the first sputtering chamber was set to 0.2 Pa.
• the amount of oxygen introduced per 100 parts by volume of argon introduced into the first sputtering chamber was 10 parts by volume.
• a sintered body of indium oxide and tin oxide (ITO with a tin oxide concentration of 10% by mass) was used.
• an MF-AC power source was used (the same applies to the second to fifth sputtering chambers described below). The discharge power was 4.3 kW.
• a 14 nm thick Nb 2 O 5 layer (refractive index 2.33) was formed as the first high refractive index layer by reactive sputtering.
• argon as an inert gas and oxygen as a reactive gas were introduced into the second sputtering chamber, and the pressure in the second sputtering chamber was set to 0.5 Pa.
• the amount of oxygen introduced per 100 volume parts of argon introduced into the second sputtering chamber was 5 volume parts.
• a Nb target was used as the target.
• the discharge power was 13 kW.
• a 28 nm thick SiO2 layer (refractive index 1.46) was formed as the first low refractive index layer by reactive sputtering.
• argon as an inert gas and oxygen as a reactive gas were introduced into the third sputtering chamber, and the pressure in the third sputtering chamber was set to 0.2 Pa.
• the amount of oxygen introduced per 100 volume parts of argon introduced into the third sputtering chamber was 30 volume parts.
• a Si target was used as the target.
• the discharge power was 25 kW.
• a 105 nm thick Nb 2 O 5 layer (refractive index 2.33) was formed as the second high refractive index layer by reactive sputtering.
• argon as an inert gas and oxygen as a reactive gas were introduced into the fourth sputtering chamber, and the pressure in the fourth sputtering chamber was set to 0.5 Pa.
• the amount of oxygen introduced per 100 volume parts of argon introduced into the fourth sputtering chamber was 13 volume parts.
• the target used was a Nb target, and the discharge power was set to 27.5 kW.
• a SiO2 layer (refractive index 1.46) having a thickness of 84 nm was formed as the second low refractive index layer by reactive sputtering.
• argon as an inert gas and oxygen as a reactive gas were introduced into the fifth sputtering chamber, and the pressure in the fifth sputtering chamber was set to 0.2 Pa.
• the amount of oxygen introduced per 100 parts by volume of argon introduced into the fifth sputtering chamber was 30 parts by volume.
• a Si target was used as the target.
• the discharge power was 20.5 kW.
• an anti-fouling surface layer was formed on the second low refractive index layer.
• an 8 nm-thick anti-fouling surface layer was formed on the second low refractive index layer by a vacuum deposition method using an alkoxysilane compound containing a perfluoropolyether group as the deposition source.
• the deposition source was a solid obtained by drying "Opttool UD509" manufactured by Daikin Industries, Ltd. (an alkoxysilane compound containing a perfluoropolyether group represented by the above general formula (2), solid concentration 20% by mass).
• the heating temperature of the deposition source in the vacuum deposition method was 260°C.
• the anti-reflection film of Example 1 comprises a substrate film with an HC layer, an adhesive layer on the HC layer, and an anti-reflection layer (first high refractive index layer/first low refractive index layer/second high refractive index layer/second low refractive index layer/anti-fouling surface layer) on the adhesive layer.
• the substrate film of the anti-reflection film of Example 1 has a plasma-treated HC layer surface. This plasma treatment is an inductively coupled plasma treatment using an oxygen-containing gas generated by application of high-frequency power to a low-inductance antenna (oxygen-LAICP treatment).
• Example 2 The anti-reflection film of Example 2 was produced in the same manner as the anti-reflection film of Example 1, except for the following: In the preparation step, the following resin composition was used instead of the first resin composition to form an HC layer on the TAC film. Specifically, the following is the case.
• a mixed solvent of butyl acetate and cyclopentanone (CPN) (the mass ratio of butyl acetate to CPN was 70:30) was added to the mixed solution as a solvent to prepare a resin composition with a solid content concentration of 40% by mass.
• Comparative Example 1 The antireflection film of Comparative Example 1 was produced in the same manner as the antireflection film of Example 1, except for the following: In the plasma treatment step, argon was introduced into the plasma treatment chamber instead of oxygen to perform the plasma treatment. This plasma treatment was a treatment by inductively coupled plasma using argon-containing gas generated by application of high-frequency power to a low-inductance antenna (Ar-LAICP treatment).
• Ar-LAICP treatment argon-containing gas generated by application of high-frequency power to a low-inductance antenna
• a second device capable of performing a roll-to-roll process on the work film was used for the plasma treatment process and film formation process.
• the second device has the same configuration as the first device, except that it has a second plasma treatment chamber instead of the first plasma treatment.
• the second plasma treatment chamber has a cathode electrode and an anode electrode (both rectangular electrodes made of SUS304) as a pair of flat electrodes for generating plasma.
• the pair of flat electrodes are arranged parallel to the substrate film passing through the second plasma treatment chamber, with a gap of 50 mm between them.
• the anode electrode is arranged at a position 35 mm away from the substrate film passing through the plasma treatment chamber, and is grounded outside the plasma treatment chamber.
• the cathode electrode is arranged to face the HC layer surface of the substrate film, and is electrically connected to a high-frequency power source (RF power source, 13.56 MHz) via an impedance matcher.
• RF power source 13.56 MHz
• the length of each electrode facing the base film in the film running direction is 110 mm, and the length in the width direction is 430 mm.
• the HC surface (first side) of the base film was plasma treated (bombardment treatment).
• the running speed of the base film (film running speed) was 1.0 m/min.
• the plasma treatment conditions were as follows:
• argon was introduced into the second plasma treatment chamber, and the pressure in the plasma treatment chamber was set to 0.5 Pa.
• Capacitively coupled plasma was generated by applying a power of 500 W between the planar electrodes by a high-frequency power source.
• a bombardment treatment with argon ions Ar-BB treatment was performed on the surface of the HC layer of the substrate film.
• Comparative Example 3 The anti-reflective film of Comparative Example 3 was produced in the same manner as the anti-reflective film of Comparative Example 2, except for the following: In the preparation step, the second resin composition was used instead of the first resin composition to form an HC layer on the TAC film. Specifically, the procedure is as follows.
• a long TAC film (product name "KC4UY", thickness 40 ⁇ m, manufactured by Konica Minolta Advanced Layer Co., Ltd.) was prepared.
• the second resin composition was applied to one side of the TAC film to form a coating film.
• the coating film was dried by heating and then cured by ultraviolet irradiation. As a result, a 7 ⁇ m thick HC layer was formed on the TAC film.
• the heating temperature was 90° C., and the heating time was 1 minute.
• a high-pressure mercury lamp was used as a light source, and ultraviolet rays with a wavelength of 365 nm were irradiated onto the coating film, and the cumulative irradiation light amount was 300 mJ/cm 2.
• a TAC film with an HC layer was produced as a substrate film.
• the HC layer of the substrate film in Comparative Example 3 contains 50% by mass of nanosilica particles.
• ⁇ Surface roughness> The surface roughness of the antireflection layer surface was examined for each of the antireflection films of Example 1, Example 2, and Comparative Examples 1 to 3. Specifically, the surface roughness Sa (arithmetic mean height based on ISO 25178-2:2012) of the exposed surface of the antireflection layer in the antireflection film was measured in an observation image of 1 ⁇ m square using an atomic force microscope (product name "Dimension Edge SPC-160113-01", manufactured by Bruker). In this measurement, the measurement mode was set to tapping mode, and an antimony-doped Si cantilever (product name "RTESP-300", manufactured by Bruker) was used as a probe. The measurement results are shown in Table 1.
• RTESP-300 antimony-doped Si cantilever
• the side of the anti-reflection film opposite the anti-reflection layer was attached to a black acrylic plate (2 mm thick) via a specified transparent acrylic adhesive. This resulted in a laminated film.
• a film piece for measurement was cut out from the laminated film.
• the spectrum of the total reflected light (including specular reflected light) of the film piece was measured using a spectrophotometer (product name "UH4150", manufactured by Hitachi High-Tech Science Corporation).
• standard light source D65 was used as the light source, and the film piece was placed in the spectrophotometer so that light was irradiated from the anti-reflection layer side of the film piece. The measurement was performed in the integrating sphere measurement mode of the spectrophotometer.
• the reflectance measured is the total reflectance (visual reflectance) of light irradiated from standard light source D65 with a wavelength of 380 nm to 780 nm on the anti-reflection layer side of the film piece (anti-reflection film).
• the measurement results are shown in Table 1.
• FIG. 6 shows a schematic observation image of the cross-section of the sample of Example 1.
• FIG. 7 is a schematic representation of an observation image of the cross section of the sample of Comparative Example 3.
• Test 1 First, the substrate film side of the anti-reflection film was fixed to a glass plate. Next, the anti-reflection layer of the anti-reflection film on the glass plate was irradiated with light for 32.5 hours under the conditions of a temperature of 85°C, a relative humidity of 45%, and an irradiation intensity (290 nm to 450 nm integrated illuminance) of 150 mW/ cm2 (accelerated weather resistance test). This test was performed using Iwasaki Electric's "Eye Super UV Tester SUV-W161".
• Test 2 First, 11 parallel first incisions (2 mm apart) extending linearly in the first direction and 11 parallel second incisions (2 mm apart) extending linearly in the second direction perpendicular to the first direction were formed on the anti-reflection layer and the adhesive layer of the anti-reflection film on the glass plate after the first test by a cutter knife, and 100 squares were formed by the first and second incisions.
• isopropyl alcohol was continuously dripped at 2 mL/min on the area of the 100 squares in the anti-reflection film, while a polyester wiper (trade name "Anticon Gold", manufactured by Sanplatec Co., Ltd.) was slid under the conditions of a wiper contact surface of 20 mm x 20 mm, a load of 1.5 kg/20 mm, a sliding speed of 50 mm/sec, and 1000 reciprocations.
• a polyester wiper trade name "Anticon Gold", manufactured by Sanplatec Co., Ltd.
• the number of squares that had peeled off by 1 mm2 or more was counted among the 100 squares.
• the number of counts was divided by 100 to calculate the peeling rate (%).
• the HC layer of the substrate film does not contain particles, so the substrate film surface does not have unevenness caused by particles.
• the plasma treatment in the manufacturing process of the anti-reflection film of Comparative Example 1 is, as described above, a treatment by inductively coupled plasma using argon-containing gas (Ar-LAICP treatment).
• the Ar-LAICP treatment does not roughen the substrate film surface as compared with the oxygen-LAICP treatment.
• the ratio (L2/L1) of the second interface length L2 to the first interface length L1 was significantly lower than 1.10. Therefore, the anti-reflection film of Comparative Example 1 could not ensure the adhesion of the anti-reflection layer.
• the HC layer of the substrate film does not contain particles, so the substrate film surface does not have unevenness caused by particles.
• the plasma treatment in the manufacturing process of the anti-reflective film of Comparative Example 2 is, as described above, ion bombardment treatment by capacitively coupled plasma using argon-containing gas (Ar-BB treatment). Compared to oxygen-LAICP treatment, Ar-BB treatment does not roughen the substrate film surface.
• Ar-BB treatment does not roughen the substrate film surface.
• the ratio of the second interface length L2 to the first interface length L1 (L2/L1) was significantly lower than 1.10. Therefore, the adhesion of the anti-reflective layer could not be ensured in the anti-reflective film of Comparative Example 2.
• the HC layer of the substrate film contains 50% by mass of nanosilica particles. Therefore, as shown in FIG. 7, the surface of the substrate film 10 (the surface on the adhesive layer 21 side) has irregularities caused by particles (not shown). In such an anti-reflection film of Comparative Example 3, the irregularities on the substrate film surface are reflected on the surface of the anti-reflection layer (the surface opposite the substrate film). Therefore, in the anti-reflection film of Comparative Example 3, the surface roughness Sa of the anti-reflection layer was large at 5.01 nm. Therefore, the total reflectance of the anti-reflection film of Comparative Example 3 was large at 0.46%.
• the HC layer of the substrate film does not contain particles. Therefore, as shown in FIG. 6, the surface of the substrate film 10 (the surface on the adhesive layer 21 side) does not have unevenness caused by particles. Therefore, in the anti-reflective film of Example 1, the surface roughness Sa of the anti-reflective layer was small, at 1.53 nm. Therefore, the total reflectance of the anti-reflective film of Example 1 was 0.31%, which was smaller than the total reflectance (0.46%) in Comparative Example 3.
• the plasma treatment in the manufacturing process of the anti-reflective film of Example 1 is, as described above, a treatment by inductively coupled plasma using an oxygen-containing gas generated by application of high-frequency power to a low-inductance antenna (oxygen-LAICP treatment).
• oxygen-LAICP treatment the substrate film surface can be roughened with fine unevenness on the nanometer order, compared to the Ar-LAICP treatment and the Ar-BB treatment. As shown in FIG. 6, this is evident on the surface (interface between high refractive index layer 22a and low refractive index layer 22b) opposite to substrate film 10 of two layers, adhesive layer 21 and high refractive index layer 22a, formed on substrate film 10.
• second fine irregularities are formed that grow from the first fine irregularities (first fine irregularities) on the substrate film 10 surface as starting points.
• the ratio (L2/L1) of the second interface length L2 to the first interface length L1 was 1.10 or more. Therefore, the anti-reflection film of Example 1 was able to ensure the adhesion of the anti-reflection layer. This is also true of Example 2.
• the anti-reflection film of the present invention is suitable for use in the manufacture of display devices such as liquid crystal displays and organic EL displays.

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