Hard coat film and laminated film

Abstract

To provide a hard coat film and a laminate film with which it is possible to secure the adhesion of an inorganic material layer formed on a hard coat layer.SOLUTION: A hard coat film X according to the present invention comprises a base film 11 and a hard coat layer 12 on the base film 11. The hard coat layer 12 is a cured substance of a composition containing an ultraviolet curable resin. The surface roughness Sa of a surface 12a of the hard coat layer 12 on the side reverse from the base film 11 is 0.80 nm to 4.50 nm inclusive. The softening temperature of the surface 12a of the hard coat layer 12 is T1(°C). The difference between a softening temperature T2(°C) of the surface 12a after prescribed plasma processing test and the softening temperature T1(°C) is 5°C or less. A laminate film Y according to the present invention comprises the hard coat film X and an inorganic substance layer 20 on the hard coat layer 12 of the hard coat film X.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a hard coat film and a laminated film.

Background Art

[0002] From the viewpoints of weight reduction and high functionality of electronic products, various composite materials in which an organic material and an inorganic material are combined have been developed. As the composite material, for example, a laminated film including a base film made of an organic material and an inorganic layer on the base film is known. In the manufacturing process of the laminated film, for example, before the inorganic layer is formed on the base film, a hard coat (HC) layer is formed on the inorganic layer side of the base film, and the base film with the HC layer is used as a hard coat film. The HC layer is a layer that makes it difficult for scratches to be formed on the exposed surface of the inorganic layer. Technologies related to such hard coat films and laminated films are described in, for example, Patent Document 1 below.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Patent Document 1 describes a laminated film as an antireflection film. This laminated film includes an inorganic layer as an antireflection layer and a hard coat film that supports the inorganic layer. The hard coat film includes a base film and an HC layer on the base film. The HC layer contains nanosilica particles. As a result, the HC layer has surface irregularities on the inorganic layer side. According to Patent Document 1, the surface irregularities of the HC layer enhance the adhesion of the inorganic layer to the base film.

[0005] The HC layer of Patent Document 1 is formed as follows. First, an ultraviolet-curable composition containing an ultraviolet-curable resin and nano-silica particles is prepared. Next, the composition is applied to one side of a base film to form a coating film. Next, the coating film is cured by causing a curing reaction to proceed within the coating film by irradiating the coating film with ultraviolet rays (ultraviolet curing step).

[0006] However, regarding such an HC layer, the present inventors obtained the following findings. In the ultraviolet curing step, in the surface and its vicinity (surface layer region) of the coating film on the base film, which is opposite to the base film, a part of the curing reaction is inhibited by oxygen. Therefore, in the surface layer region, the curing reaction does not proceed sufficiently, and a relatively low molecular weight polymer is formed. This low molecular weight polymer is mechanically weaker compared to the high molecular weight polymer formed in the inner region (the region closer to the base film than the surface layer region). That is, the HC layer formed by the ultraviolet curing step has a fragile thin layer on the surface and its vicinity opposite to the base film. And this fragile thin layer reduces the adhesion of the inorganic layer formed on the HC layer to the base film.

[0007] The present invention provides a hard coat film and a laminated film capable of ensuring the adhesion of an inorganic layer formed on a hard coat layer.

Means for Solving the Problems

[0008] The present invention [1] is a hard coat film including a base film and a hard coat layer on the base film, wherein the hard coat layer is a cured product layer of a composition containing an ultraviolet-curable resin, the surface roughness Sa of the surface of the hard coat layer opposite to the base film is 0.80 nm or more and 4.50 nm or less, the softening temperature of the surface of the hard coat layer is T1, and the difference between the softening temperature T2 after the following plasma treatment test of the surface and the softening temperature T1 is 5°C or less, including a hard coat film.

[0009] Plasma treatment test: The surface of the hard coat layer is treated with inductively coupled plasma of oxygen gas generated by applying high-frequency power of 13.56 MHz and 5.0 kW to the low-inductance antenna.

[0010] The present invention [2] includes the hard coat film according to [1] above, wherein the ultraviolet curable resin is at least one selected from the group consisting of an ultraviolet curable acrylic urethane resin and an ultraviolet curable acrylic resin.

[0011] The present invention [3] includes the hard coat film according to [1] or [2] above, wherein the softening temperature T1 is 105 °C or higher.

[0012] The present invention [4] includes the hard coat film according to any one of [1] to [3] above, wherein the softening temperature T1 is 150 °C or lower.

[0013] The present invention [5] includes a laminated film including the hard coat film according to any one of [1] to [4] above and an inorganic layer on the hard coat layer of the hard coat film.

Advantages of the Invention

[0014] In the hard coat film of the present invention, as described above, the surface roughness Sa of the surface of the hard coat layer (a cured product layer of a composition containing an ultraviolet curable resin) on the side opposite to the base film is 0.80 nm or more and 4.50 nm or less, and the difference (|T2 - T1|) between the softening temperature T1 of the surface of the hard coat (HC) layer and the softening temperature T2 of the surface after the plasma treatment test of the surface is 5 °C or less. The fact that the surface roughness Sa in the HC layer is 0.80 nm or more and 4.50 nm or less enhances the adhesion of the inorganic layer to the hard coat film due to the anchor effect of the HC layer on the inorganic layer when the inorganic layer is formed on the HC layer. Further, the fact that the above softening temperature difference is 5 °C or less indicates that the HC layer substantially does not have the above-described fragile thin layer. Therefore, the hard coat film of the present invention can ensure the adhesion of the inorganic layer formed on the HC layer. The laminated film of the present invention provided with such a hard coat film can ensure the adhesion of the inorganic layer on the hard coat layer.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0016] As shown in FIG. 1, the hard coat film X according to an embodiment of the present invention includes a substrate film 11 and a hard coat (HC) layer 12 in this order in the thickness direction H. The HC layer 12 is disposed on the substrate film 11. That is, the substrate film 11 and the HC layer 12 are in contact with each other. The hard coat film X extends in a direction (plane direction D) orthogonal to the thickness direction H.

[0017] The substrate film 11 is an element for ensuring the strength of the hard coat film X. The substrate film 11 is, for example, a flexible transparent resin film. Examples of the material of the substrate film 11 include polyester resins, polyolefin resins, cellulose resins, acrylic resins, polycarbonate resins, polyethersulfone resins, polyarylate resins, melamine resins, polyamide resins, polyimide resins, and polystyrene resins. Examples of the polyester resin include polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate. Examples of the polyolefin resin include polyethylene, polypropylene, and cycloolefin polymer (COP). Examples of the cellulose resin include triacetyl cellulose (TAC). These materials may be used alone or in combination of two or more. From the viewpoints of transparency and strength, the material of the substrate film 11 is preferably at least one selected from the group consisting of polyester resins, polyolefin resins, and cellulose resins, and more preferably at least one selected from the group consisting of PET, COP, and TAC. Further, the substrate film 11 does not contain particles in the present embodiment.

[0018] The thickness of the base film 11 is preferably 10 μm or more, more preferably 20 μm or more, still more preferably 30 μm or more, and is preferably 200 μm or less, more preferably 150 μm or less, still more preferably 100 μm or less. When the thickness of the base film 11 is equal to or greater than the above lower limit value, the strength of the hard coat film X can be ensured. When the thickness of the base film 11 is equal to or less than the above upper limit value, the handleability of the hard coat film X in the roll-to-roll process described later can be ensured. Further, a carrier film (not shown) may be laminated on the back surface of the base film 11 (the surface opposite to the HC layer 12) in order to ensure the transportability and handleability of the base film 11 in the roll-to-roll process.

[0019] The total light transmittance (JIS K 7375:2008) of the base film 11 is preferably 80% or more, more preferably 90% or more, still more preferably 95% or more, and is, for example, 100% or less. When the total light transmittance of the base film 11 is equal to or greater than the above lower limit value, good transparency can be ensured in the hard coat film X.

[0020] The HC layer 12 is a layer that makes it difficult for scratches to be formed on the exposed surface of the layer formed on the HC layer 12 (the inorganic layer 20 in the embodiment shown in FIG. 2). The HC layer 12 is a cured product layer of a composition containing an ultraviolet curable resin (ultraviolet curable resin composition).

[0021] Examples of the ultraviolet curable resin 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 resins may be used alone or in combination of two or more. From the viewpoint of ensuring the hardness of the HC layer 12, the ultraviolet curable resin is at least one selected from the group consisting of ultraviolet curable acrylic urethane resin and ultraviolet curable acrylic resin.

[0022] The inorganic oxide particles contained in the HC layer 12 are preferably less in amount. The smaller the amount of the inorganic oxide particles in the HC layer 12, the more the scattering of the light incident on the hard coat film X caused by the particles can be suppressed, and the manufacturing cost of the hard coat film X can be reduced. Examples of the material of the inorganic oxide particles include silica, alumina, titania, zirconia, calcium oxide, tin oxide, indium oxide, cadmium oxide, and antimony oxide. The content of the inorganic oxide particles in the HC layer 12 is preferably 20% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, even more preferably 1% by mass or less, yet even more preferably 0.5% by mass or less, still more preferably 0.2% by mass or less, even more preferably 0.1% by mass or less, and particularly preferably 0.0% by mass.

[0023] The thickness of the HC layer 12 is preferably 1 μm or more, more preferably 3 μm or more, still more preferably 5 μm or more, and is preferably 30 μm or less, more preferably 25 μm or less, still more preferably 20 μm or less. When the thickness of the HC layer 12 is at least the above lower limit value, the scratch resistance by the HC layer 12 can be ensured. When the thickness of the HC layer 12 is at most the above upper limit value, the transparency of the HC layer 12 can be ensured.

[0024] The HC layer 12 has a surface 12a on the side opposite to the base film 11. The surface roughness Sa (arithmetic mean height based on ISO 25178-2:2012) of the surface 12a is preferably 0.80 nm or more, more preferably 1.00 nm or more, still more preferably 1.20 nm or more, and is preferably 4.50 nm or less, more preferably 3.50 nm or less, still more preferably 3.00 nm or less, even more preferably 2.50 nm or less, and more preferably 2.00 nm or less. When the surface roughness Sa of the surface 12a is at least the above lower limit value, the adhesion of the same layer to the hard coat film X is enhanced due to the anchor effect of the fine irregularities of the surface 12a on the layer (the inorganic layer 20 in the embodiment shown in FIG. 2) formed on the surface 12a. When the surface roughness Sa of the surface 12a is at most the above upper limit value, excessive irregularities can be suppressed on the surface 12a to ensure mechanical strength.

[0025] The surface 12a is, in this embodiment, a surface that has been plasma-treated. The plasma treatment is preferably a treatment by inductively coupled plasma using an oxygen-containing gas (oxygen-LAICP treatment) generated by applying high-frequency power to a low-inductance antenna, from the viewpoint of reducing the softening temperature difference (|T2 - T1|) described below. The oxygen-LAICP treatment for the surface 12a will be specifically described in the method for manufacturing the laminated film Y (shown in FIG. 2).

[0026] The surface 12a of the HC layer 12 has a softening temperature T1 (°C). The surface 12a has a softening temperature T2 (°C) after the following plasma treatment test. The softening temperatures T1 and T2 mean the softening temperatures measured by nano thermal analysis. Nano thermal analysis is an analytical method for measuring the thermal properties (such as softening temperature and glass transition point) of a sample surface on a nanoscale by bringing a temperature-adjustable microcantilever into contact with the sample surface as a probe. The method for measuring the softening temperatures T1 and T2 by nano thermal analysis and the method for the plasma treatment test will be specifically as described below with respect to the examples.

[0027] Plasma treatment test: The surface of the hard coat layer is treated with inductively coupled plasma of oxygen gas generated by applying high-frequency power of 13.56 MHz and 5.0 kW to a low-inductance antenna.

[0028] The difference (|T2 - T1|) between the softening temperature T2 and the softening temperature T1 is 5°C or less, preferably 4°C or less, and for example, 0°C or more. The fact that the difference between the softening temperature T2 and the softening temperature T1 is 5°C or less indicates that the HC layer 12 substantially does not have the above-described fragile thin layer on the surface 12a.

[0029] The softening temperature T1 is preferably 105°C or higher, more preferably 115°C or higher, still more preferably 125°C or higher, and is preferably 150°C or lower, more preferably 140°C or lower, still more preferably 130°C or lower. When the softening temperature T1 is at or above the above lower limit value, the fragile thin layer on the surface of the HC layer 12 is sufficiently removed, and the adhesion of the inorganic layer to the hard coat film X can be ensured. When the softening temperature T1 is at or below the above upper limit value, the flexibility of the hard coat film X is ensured, and the occurrence of cracks or the like in the HC layer 12 during film conveyance can be suppressed.

[0030] The total light transmittance (JIS K 7375:2008) of the hard coat film X is preferably 80% or higher, more preferably 90% or higher, still more preferably 95% or higher, and is, for example, 100% or lower. When the total light transmittance of the hard coat film X is at or above the above lower limit value, good transparency can be ensured in the hard coat film X.

[0031] In the hard coat film X, as described above, the surface roughness Sa of the surface 12a on the side opposite to the base film 11 in the HC layer 12 (the cured product layer of the composition containing the ultraviolet curable resin) is 0.80 nm or more and 4.50 nm or less, and the difference (|T2 - T1|) between the softening temperature T1 of the surface 12a of the HC layer 12 and the softening temperature T2 of the surface 12a after the above plasma treatment test is 5°C or less. The fact that the surface roughness Sa in the HC layer 12 is 0.80 nm or more and 4.50 nm or less enhances the adhesion of the inorganic layer to the hard coat film X due to the anchor effect of the HC layer 12 on the inorganic layer when the inorganic layer is formed on the HC layer 12. Also, the fact that the above softening temperature difference is 5°C or less indicates that the HC layer 12 substantially does not have the above fragile thin layer. Therefore, the hard coat film X can ensure the adhesion of the inorganic layer formed on the HC layer 12.

[0032] Figure 2 is a schematic cross-sectional view of a laminated film Y according to an embodiment of the present invention. The laminated film Y includes a hard coat film X and an inorganic layer 20 on the hard coat film X. Specifically, the inorganic layer 20 is disposed on the HC layer 12 of the hard coat film X. The inorganic layer 20 is in contact with the HC layer 12. Such a laminated film Y extends in a direction (plane direction D) orthogonal to the thickness direction H.

[0033] Examples of the inorganic layer 20 include an antireflection layer and a conductive layer. The antireflection layer is a layer having antireflection properties for suppressing the reflection intensity of external light. The conductive layer is a layer having conductivity. The inorganic layer 20 may be other layers. Also, the inorganic layer 20 may be a composite layer including an antireflection layer and other layers. The inorganic layer 20 may be a composite layer including a conductive layer and other layers. A case where the inorganic layer 20 has a laminated structure of an adhesion layer 21 and an antireflection layer 22 is shown in FIG. 3.

[0034] The adhesion layer 21 is disposed on the HC layer 12 of the hard coat film X. Specifically, the adhesion layer 21 is disposed on the surface 12a of the HC layer 12. The adhesion layer 21 is in contact with the HC layer 12. The adhesion layer 21 is a layer that enhances the adhesion of the inorganic layer 20 to the hard coat film X. Examples of the material of the adhesion layer 21 include metals such as Si, In, Ni, Cr, Ar, Sn, Au, Ag, Pt, Zn, Ti, W, Zr, Pd, Nb, alloys of two or more of these metals, and oxides of these metals. From the viewpoint of achieving both the adhesion to both the hard coat film X and the inorganic layer 20 and the transparency of the adhesion layer 21, the adhesion layer 21 is preferably an inorganic oxide film containing at least one element selected from the group consisting of Si, In, Al, Sn, Ti, and Zr. From the viewpoint of achieving both the adhesion to both the hard coat film X and the inorganic layer 20 and the transparency of the adhesion layer 21, indium tin composite oxide (ITO) or silicon oxide (SiOx) is more preferable as the material of the adhesion layer 21. The silicon oxide as the material of the adhesion layer 21 is preferably SiOx having an oxygen amount less than the stoichiometric composition, and more preferably SiOx where x is 1.2 or more and 1.9 or less.

[0035] The thickness of the adhesion layer 21 is preferably 1 nm or more, more preferably 2 nm or more, still more preferably 3 nm or more, and preferably 50 nm or less, more preferably 30 nm or less, still more preferably 10 nm or less, and even more preferably 5 nm or less. When the thickness of the adhesion layer 21 is at least the above lower limit value, the adhesion between the hard coat film X and the inorganic layer 20 can be ensured. When the thickness of the adhesion layer 21 is at most the above upper limit value, the transparency of the adhesion layer 21 can be ensured.

[0036] The antireflection layer 22 is disposed on one surface in the thickness direction H of the adhesion layer 21. The antireflection layer 22 preferably includes a plurality of transparent inorganic oxide films laminated in the thickness direction H. FIG. 3 shows an example of such an antireflection layer 22. The antireflection layer 22 in FIG. 3 includes a high refractive index layer 22a, a low refractive index layer 22b, a high refractive index layer 22c, and a low refractive index layer 22d in this order from the adhesion layer 21 side in the thickness direction H. The high refractive index layer 22a is in contact with the adhesion layer 21. The high refractive index layer 22a and the low refractive index layer 22b are in contact with each other. The low refractive index layer 22b and the high refractive index layer 22c are in contact with each other. The high refractive index layer 22c and the low refractive index layer 22d are in contact with each other. The high refractive index layers 22a and 22c are layers having a relatively large refractive index, and the low refractive index layers 22b and 22d are layers having a relatively small refractive index. In such a laminated structure, the intensity of the reflected light is attenuated by the interference action between the reflected lights at a plurality of interfaces in the high refractive index layers 22a and 22c and the low refractive index layers 22b and 22d. Such an interference action can be achieved by adjusting the optical film thickness (the product of the refractive index and the thickness of the film) of each layer of the inorganic layer 20.

[0037] The high refractive index layer 22a (the 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. Examples of the high refractive index material include niobium oxide (Nb2O5), titanium oxide, zirconium oxide, indium tin composite oxide (ITO), and antimony tin composite oxide (ATO). From the viewpoint of achieving both a high refractive index and low absorbability of visible light, the high refractive index material is preferably niobium oxide (refractive index 2.33). The optical film thickness of the high refractive index layer 22a is, for example, 20 nm or more and, for example, 55 nm or less.

[0038] The low refractive index layer 22b (the 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. Examples of the low refractive index material include silicon dioxide (SiO2) and magnesium fluoride. From the viewpoint of achieving both a low refractive index and low absorbability 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.

[0039] The high refractive index layer 22c (the 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. Examples of the high refractive index material 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.

[0040] The low refractive index layer 22d (the second 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. Examples of the low refractive index material 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.

[0041] The total thickness of the antireflection layer 22 is preferably 180 nm or more, more preferably 200 nm or more, still more preferably 220 nm or more, and is preferably 320 nm or less, more preferably 280 nm or less, still more preferably 250 nm or less. In this embodiment, the total thickness of the antireflection layer 22 is the sum of the thicknesses of the high refractive index layers 22a and 22c and the low refractive index layers 22b and 22d. When the total thickness of the antireflection layer 22 is equal to or greater than the above lower limit value, the function of attenuating the reflected light intensity can be ensured in the antireflection layer 22. When the total thickness of the antireflection layer 22 is equal to or less than the above upper limit value, cracking of the antireflection layer 22 can be suppressed.

[0042] When the inorganic layer 20 includes a conductive layer, the conductive layer is formed of a conductive material. Examples of the conductive material include metals and metal oxides. Examples of the metal include copper, silver, gold, and alloys thereof. Examples of the metal oxide include indium-containing conductive oxides and antimony-containing conductive oxides. Examples of the indium-containing conductive oxide include indium tin composite oxide (ITO), indium zinc composite oxide (IZO), indium gallium composite oxide (IGO), and indium gallium zinc composite oxide (IGZO). Examples of the antimony-containing conductive oxide include antimony tin composite oxide (ATO).

[0043] From the viewpoint of ensuring the adhesion of the inorganic layer 20, the peeling rate of the inorganic layer 20 in the following second test after the following first test (accelerated weather resistance test) of the laminated film Y is preferably 5% or less, more preferably 3% or less, still more preferably 1% or less. The methods of the first test and the second test are more specifically as described later with respect to the examples. When the peeling rate of the inorganic layer 20 is equal to or less than the above upper limit value, a substantial decrease in the function of the inorganic layer 20 due to peeling of the inorganic layer 20 can be suppressed.

[0044] First test: First, fix the side of the hard coat film X in the laminated film Y to a glass plate. Next, with respect to the inorganic layer 20 of the laminated film Y on the glass plate, irradiate it with light for 32.5 hours under the conditions of a temperature of 85 °C, a relative humidity of 45%, and an irradiation intensity (integrated illuminance of 290 nm to 450 nm) of 150 mW / cm 2 .

[0045] Second test: First, with respect to the inorganic layer 20 and the adhesion layer 21 in the laminated film Y on the glass plate after the first test, use a cutter knife to form 11 parallel first cuts (at 1 mm intervals) linearly extending in the first direction and 11 parallel second cuts (at 1 mm intervals) linearly extending in the second direction orthogonal to the first direction, and form 100 meshes by the first and second cuts. Next, while continuously dropping isopropyl alcohol at 2 mL / min onto the area of 100 meshes in the laminated film Y, slide a polyester wiper under the conditions of a wiper contact surface of 20 mm × 20 mm, a load of 1.5 kg / 20 mm□, a sliding speed of 50 mm / second, and 100 reciprocations. Next, among the 100 meshes, count the number of meshes with peeling of 1 mm 2 or more. Next, divide the counted number by 100 to calculate the peeling rate (%).

[0046] As described above, the laminated film Y includes the hard coat film X and the inorganic layer 20 on the HC layer 12 of the hard coat film X. In the hard coat film X, as described above, the surface roughness Sa of the surface 12a on the side opposite to the base film 11 in the HC layer 12 (a cured product layer of a composition containing an ultraviolet curable resin) is 0.80 nm or more and 4.50 nm or less, and the difference (|T2 - T1|) between the softening temperature T1 of the surface 12a of the HC layer 12 and the softening temperature T2 of the surface 12a after the plasma treatment test is 5 °C or less. Therefore, the laminated film Y can ensure the adhesion of the inorganic layer 20 on the HC layer 12 in the same manner as described above for the hard coat film X.

[0047] Figures 4A to 4C illustrate an example of a method for manufacturing the laminated film Y. This manufacturing method includes a cured resin layer forming step (Figure 4A), a plasma treatment step (Figure 4B), and a film forming step (Figure 4C).

[0048] In the cured resin layer forming step, as shown in Figure 4A, an HC layer 12' is formed on a long base film 11. Thereby, the hard coat film X' is obtained. The HC layer 12' can be formed by applying the above-described ultraviolet curable resin composition on the base film 11 to form a coating film and then curing this coating film. The ultraviolet curable resin composition may contain other components other than the above-described ultraviolet curable resin as necessary. Examples of other components include a solvent, a photoinitiator, and a leveling agent. Examples of the solvent include butyl acetate, ethyl acetate, toluene, and cyclopentanone.

[0049] When the ultraviolet curable resin composition contains a solvent, the coating film on the base film 11 is dried after the application of the ultraviolet curable resin composition. 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 longer and, for example, 10 minutes or shorter. The coating film on the base film 11 is cured by ultraviolet irradiation. Examples of the light source for ultraviolet irradiation include a high-pressure mercury lamp and an LED light. The integrated irradiation light amount of ultraviolet rays is, for example, 100 mJ / cm 2 or more and, for example, 500 mJ / cm 2 or less.

[0050] As described above, a long hard coat film X' can be produced. In this embodiment, a roll of the long hard coat film X' is prepared. Specifically, the hard coat film X' is wound so that the surface on the HC layer 12' side in the hard coat film X' faces the inner side in the roll diameter direction.

[0051] In this manufacturing method, next, while conveying the hard coat film X' as the work film W in a roll-to-roll manner under a reduced pressure atmosphere, a plasma treatment step and a film forming step are sequentially performed. The apparatus Z shown in FIG. 5 is an example of an apparatus for performing the plasma treatment step and the film forming step. The apparatus Z includes an unwinding chamber R1, a winding chamber R2, a connection chamber C1, a plasma treatment chamber C2, a connection chamber C3, a film forming chamber C4, a connection chamber C5, a connection chamber C6, and a PEM apparatus (not shown).

[0052] The unwinding chamber R1 is provided with an unwinding roller 51 for unwinding the work film W. A roll of a long hard coat film X' is attached as the work film W to the unwinding roller 51. Also, a predetermined number of guide rollers G for guiding the work film W are provided in the unwinding chamber R1.

[0053] The winding chamber R2 is provided with a winding roller 52 for winding the work film W. A predetermined number of guide rollers G for guiding the work film W are provided in the winding chamber R2.

[0054] The connection chamber C1 is arranged next to the unwinding chamber R1 and in front of the plasma treatment chamber C2 in the running direction of the work film W. A predetermined number of guide rollers G for guiding the work film W are provided in the connection chamber C1. The connection chamber C1 is connected to a vacuum pump (not shown) and is configured to be able to adjust the internal pressure. When the apparatus Z is in operation, the pressure in the connection chamber C1 is maintained at a predetermined pressure between the pressure in the unwinding chamber R1 and the pressure in the plasma treatment chamber C2. Thereby, a differential pressure between the unwinding chamber R1 and the plasma treatment chamber C2 is ensured.

[0055] The plasma treatment chamber C2 is arranged between the connection chamber C1 and the connection chamber C3 in the running direction of the work film W. In the plasma treatment chamber C2, a plasma treatment step is performed as described later.

[0056] In this embodiment, the plasma processing chamber C2 is provided with a plurality of low-inductance antennas (LA) 71. A low-inductance antenna means an antenna that has a low inductance of 7.5 μH or less and can generate inductively coupled plasma by applying high-frequency power. In this embodiment, as shown in FIGS. 6 and 7, the LA 71 is disposed in the plasma processing chamber C2 while being supported by a fixture 72 and covered with a cover block 73 (omitted in FIG. 6). (The case where the number of LA 71 is 4 is illustratively shown.)

[0057] The plurality of LA 71 are arranged in alignment so as to be aligned in the traveling direction of the work film W and in a direction orthogonal to the traveling direction (the width direction of the work film W). The fixture 72 is a vacuum flange. As shown in FIG. 7, the LA 71 is fixed to the fixture 72 via a field-through 74. As shown in FIG. 5, the fixture 72 is assembled to an opening 75 provided in the wall portion of the plasma processing chamber C2. Specifically, the fixture 72 is assembled to the opening 75 with a seal member (not shown) sandwiched between the wall portion of the plasma processing chamber C2 and the fixture 72. The LA 71 is electrically connected to a high-frequency power source (RF power source) via an impedance matcher outside the plasma processing chamber C2. Such an LA 71 is formed of a conductor. Examples of the conductor include copper and silver, and copper is preferred. The LA 71 may be covered with an insulator. Examples of the insulator include glass and quartz.

[0058] The cover block 73 includes a block main body 73A and a plurality of partition plates 73B. The block main body 73A has a plurality of accommodation spaces 73a. One LA71 is accommodated in each accommodation space 73a. The partition plates 73B are arranged to close the accommodation spaces 73a. The inside of the accommodation space 73a is a sealed space. In the cover block 73, the block main body 73A is made of, for example, aluminum. Examples of the aluminum include aluminum A5052. The partition plates 73B are made of an insulating material. Examples of the insulating material include quartz and glass. Further, the separation distance d’ (shown in FIG. 7) between the work film W traveling 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 applied power to the LA71, and also helps to suppress damage to the work film W to be plasma-treated.

[0059] As shown in FIG. 6, in this embodiment, LA71 has an open-loop shape. The fact that LA71 has an open-loop shape is advantageous for reducing the inductance of LA71. Therefore, according to the open-loop-shaped LA71, an increase in voltage due to an increase in the applied power to LA71 can be suppressed. As a result, abnormal discharge during plasma processing described later can be suppressed. By suppressing abnormal discharge, damage to the hard coat film X' (work film W) to be plasma-processed can be suppressed. Specifically, 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 arranged in the width direction of the work film W. Further, in this embodiment, LA71 has an extension portion 71a on the side opposite to the two free ends. The extension portion 71a extends parallel to the work film W passing through the plasma processing chamber C2. The extension portion 71a extends in the width direction of the work film W. Each extension portion 71a may extend in the running direction of the work film W (four LA71s may be arranged in this way). The length of the extension portion 71a is, for example, 50 to 150 mm (FIG. 6 illustratively shows the case where the length of the extension portion 71a is the same as the maximum length d2 of LA71 described later). LA71 may have a coil shape instead of the open-loop shape.

[0060] LA71 extends from the fixture 72 toward the work film W. LA71 preferably extends in a direction perpendicular to the fixture 72. The extension length d1 of LA71 from the fixture 72 is, for example, 30 to 150 mm. The maximum length d2 of LA71 in the plane direction of the work film W is, for example, 50 to 150 mm. The separation distance d3 (shown in FIG. 7) between LA71 and the work film W is, for example, 50 to 200 mm. The extension length d1 and the separation distance d3 are preferably the same. The ratio (d3 / d1) of the separation distance d3 to the extension length d1 is, for example, 0.5 to 3.5. The number (number of columns) of LA71 arranged spaced apart in the running direction of the work film W may be 1, or may be 2 or 3, or may be 4 or more if necessary, depending on the running speed of the work film W (i.e., the plasma treatment time). In the running direction of the work film W, the center-to-center distance d4 between adjacent LA71 is, for example, 100 to 500 mm. In the width direction of the work film W, the center-to-center distance d5 between adjacent LA71 is, for example, 200 to 500 mm. By adjusting the center-to-center distance d5, the uniformity of the plasma density described below in the width direction of the work film W can be controlled. The center-to-center distance d4 and the center-to-center distance d5 are preferably the same. The ratio (d5 / d4) of the center-to-center distance d5 to the center-to-center distance d4 is, for example, 0.5 to 2.0. The center points of the extending portions 71a of the four LA71 preferably form a square as vertices. With such a set of LA71, high-density plasma can be generated. As LA71, for example, a high-frequency antenna for plasma generation described in JP-A-2013-258153 may be used.

[0061] In this embodiment, the plasma processing chamber C2 further includes a transport roller 53. The transport roller 53 is a main guide roller for transporting the work film W within the plasma processing chamber C2. The transport roller 53 has a temperature adjustment function capable of heating or cooling the work film W. That is, the transport roller 53 is a transport roller with a temperature adjustment function. During the operation of the apparatus Z, the transport roller 53 transports the work film W while contacting the back surface of the work film W (the surface opposite to the HC layer 12). The LA71 is disposed opposite to the transport roller 53. According to the apparatus Z provided with such a plasma processing chamber C2, in the plasma processing step S2, the work film W can be cooled or heated by the transport roller 53 with a temperature adjustment function that contacts the work film W, and plasma processing can be performed on the work film W. By controlling the temperature of the work film W, thermal deformation of the work film W can be suppressed, and the influence of the thermal deformation on the transport of the work film W can be suppressed.

[0062] The PEM device is a device for performing plasma emission monitoring (PEM) during plasma processing, and includes a device main body and an optical fiber for light collection. The tip (one end) of the optical fiber is disposed between the work film W and the LA71 within the plasma processing chamber C2. The other end of the optical fiber is connected to the device main body. Further, a first line L1 with a flow rate adjustment valve for introducing gas into the chamber is connected to the plasma processing chamber C2.

[0063] The connection chamber C3 is disposed next to the plasma processing chamber C2 and in front of the film forming chamber C4 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 C3. The connection chamber C3 is connected to a vacuum pump (not shown) and is configured to be able to adjust the internal pressure. During the operation of the apparatus Z, the pressure within the connection chamber C3 is maintained at a predetermined pressure between the pressure within the plasma processing chamber C2 and the pressure within the film forming chamber C4. Thereby, a differential pressure between the plasma processing chamber C2 and the film forming chamber C4 is ensured.

[0064] The film forming chamber C4 is arranged next to the connection chamber C3 in the running direction of the work film W. Further, the film forming chamber C4 is connected to a vacuum pump (not shown) and is configured to be able to adjust the interior to a predetermined degree of vacuum. In the film forming chamber C4, a film forming process is carried out as described later.

[0065] In this embodiment, 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) (the case where the number of sputtering chambers 60 is 5 is exemplarily shown in the figure). The film forming roller 54 is a main guide roller for transporting the work film W in the film forming chamber C4. The film forming roller 54 has a temperature adjustment function capable of heating or cooling the work film W. The sputtering chamber 60 is a space partitioned 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 towards the film forming roller 54. A cathode 61 is provided in the sputtering chamber 60. A target (not shown) as a film forming material supply is arranged on the cathode 61. 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 source (not shown) for applying a voltage to the target to generate a glow discharge. Examples of the power source include a DC power source, an AC power source, an MF power source, an RF power source, and an MF-AC power source. The MF-AC power source means an AC power source 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) with flow control valves for introducing gas into the chamber. Further, a predetermined number of guide rollers G for guiding the work film W are provided in the film forming chamber C4.

[0066] The connection chambers C5 and C6 are arranged in this order between the film deposition chamber C4 and the winding chamber R2 in the running direction of the work film W. A predetermined number of guide rollers G for guiding the work film W are provided in the connection chamber C5. A predetermined number of guide rollers G for guiding the work film W are provided in the connection chamber C6. The connection chamber C5 is connected to a vacuum pump (not shown) and is configured to be able to adjust the chamber pressure. The connection chamber C6 is connected to a vacuum pump (not shown) and is configured to be able to adjust the chamber pressure. During the operation of the apparatus Z, the pressures in the connection chambers C5 and C6 are maintained at a predetermined pressure between the pressure in the film deposition chamber C4 and the pressure in the winding chamber R2. Thereby, a differential pressure between the film deposition chamber C4 and the winding chamber R2 is ensured.

[0067] With the apparatus Z as described above, the plasma treatment step and the film deposition step are sequentially performed. Specifically, it is as follows.

[0068] The work film W is fed out from the feeding chamber R1. After the work film W is fed out from the feeding chamber R1, it sequentially passes through the connection chamber C1, the plasma treatment chamber C2, the connection chamber C3, the film deposition chamber C4, the connection chamber C5, and the connection chamber C6, 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. Also, the series of lines from the feeding chamber R1 to the winding chamber R2 are not opened to the atmosphere midway, and in this line, a process under a reduced pressure atmosphere is performed. The reduced pressure atmosphere is preferably under vacuum. Under vacuum preferably means a reduced pressure atmosphere of 7 Pa or less.

[0069] In the plasma treatment chamber C2, the plasma treatment step is performed. In the plasma treatment step, the work film W is plasma-treated while detecting the plasma emission intensity under a reduced pressure atmosphere in the plasma treatment chamber C2 (chamber). In this embodiment, the plasma treatment is a treatment by inductively coupled plasma of an oxygen-containing gas (oxygen-LAICP treatment) generated by applying high-frequency power to LA71. Specifically, it is as follows.

[0070] During plasma processing, oxygen is supplied into the plasma processing chamber C2 via the first line L1. In addition to oxygen, an inert gas may be supplied into the plasma processing chamber C2. Examples of the inert gas include argon, krypton, and xenon. Further, the gas in the plasma processing chamber C2 may contain other gases other than the inert gas. Examples of the other gas 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, still more preferably 80% by volume or more, even more preferably 90% by volume or more, yet even more preferably 95% by volume or more, and particularly preferably 100% by volume. When the oxygen concentration is equal to or higher than the above lower limit value, a high-density oxygen plasma can be generated. This is useful for fine roughening of the surface of the work film W on the nanometer order and high activation by cleaning the surface.

[0071] 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, still more preferably 0.3 Pa or more, and is preferably 7 Pa or less, more preferably 5 Pa or less, still more preferably 3 Pa or less. When the first pressure is equal to or higher than the above lower limit value, a plasma environment with a sufficient density for surface modification treatment of the work film W can be formed in the plasma processing chamber C2 in plasma processing. When the first pressure is equal to or lower than the above upper limit value, damage to the work film W caused by an excessively high-density plasma can be suppressed in plasma processing. The first pressure can be adjusted by the supply amount of oxygen gas into the plasma processing chamber C2.

[0072] The frequency of the high-frequency power applied to LA71 during plasma treatment is preferably 1 MHz or higher, more preferably 5 MHz or higher, still more preferably 10 MHz or higher, and is preferably 100 MHz or lower, more preferably 80 MHz or lower, still more preferably 60 MHz or lower. When the frequency is equal to or higher than the above lower limit value, in plasma treatment, the plasma discharge can be stabilized while increasing the plasma current density. When the frequency is equal to or lower than the above upper limit value, the antenna potential can be suppressed, and thus, damage to the work film W by plasma can be suppressed. Further, the high-frequency power is preferably 0.1 kW or higher, more preferably 0.3 kW or higher, still more preferably 1.0 kW or higher, and is preferably 10 kW or lower, more preferably 8 kW or lower, still more preferably 6 kW or lower. When the high-frequency power is equal to or higher than the above lower limit value, in plasma treatment by inductively coupled plasma, a high-density plasma environment can be formed in the plasma treatment chamber C2. When the high-frequency power is equal to or lower than the above upper limit value, excessive damage to the work film W by plasma can be suppressed.

[0073] In the plasma treatment step, preferably, the plasma emission intensity in plasma treatment is monitored by a PEM device. Then, based on the monitoring results, the introduction amount of the oxygen gas, the above high-frequency power, the above traveling speed, etc. are controlled.

[0074] In the plasma treatment step, the plasma current density at an intermediate position between LA71 and the work film W is preferably 1.0 mA / cm 3 or higher, more preferably 2.0 mA / cm 3 or higher, still more preferably 3.0 mA / cm 3 or higher, and is preferably 10 mA / cm 3 or lower, more preferably 8 mA / cm 3 or lower, still more preferably 4 mA / cm 3The following is the case. Inductive coupling type plasma processing using a low inductance antenna can achieve a higher plasma current density than the capacitive coupling type plasma processing described above (for example, a plasma density about 100 times higher can be achieved). When the plasma current density is equal to or higher than the above lower limit value, sufficient plasma oxygen particles can be ensured in the plasma processing chamber C2 during plasma processing, and the surface of the work film W can be appropriately surface-modified. When the plasma current density is equal to or lower than the above upper limit value, damage to the work film W caused by excessively high-density plasma oxygen particles can be suppressed during plasma processing. Examples of the method for adjusting the plasma current density include adjusting the introduction amount of oxygen gas 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.

[0075] Through the above plasma processing on the hard coat film X’, as shown in FIG. 4B, a hard coat film X having an HC layer 12 is manufactured. By not performing the next film forming step, a hard coat film X on which an inorganic layer is not formed on the HC layer 12 is obtained.

[0076] In the film forming step, following the plasma processing step, an inorganic layer 20 is formed on the HC layer 12 of the work film W (hard coat film X) by a sputtering method in a reduced pressure atmosphere. The reduced pressure atmosphere is preferably under vacuum.

[0077] In the sputtering method, while introducing a sputtering gas (inert gas) into each sputtering chamber 60 through a first second line, a negative voltage is applied to a target (film forming material) disposed on a cathode 61 in the sputtering chamber 60. Thereby, a glow discharge is generated to ionize gas atoms, the gas ions are collided with the target surface at high speed, the target material is ejected from the target surface, and the ejected target material is deposited on the work film W. Examples of the sputtering gas include argon, krypton, and xenon.

[0078] When the film-forming material is a metal oxide, the sputtering method may be a reactive sputtering method. In the reactive sputtering method, in addition to the sputtering gas, oxygen (reactive gas) is introduced into the sputtering chamber 60. Oxygen is introduced into the sputtering chamber 60 via another second line. In the reactive sputtering method, the target is made of, for example, the metal in the metal oxide forming each layer.

[0079] In the sputtering method, the pressure (second pressure) in the sputtering chamber 60 is, for example, 0.1 to 5.0 Pa according to the type of the layer to be formed. The film-forming temperature (the temperature of the work film W adjusted by the film-forming roller 54) is, for example, -10°C to 150°C.

[0080] In the film-forming step, next, an inorganic layer 20 is formed on the HC layer 12 by a sputtering method in at least one sputtering chamber selected from the sputtering chambers 60a to 60e. For example, when manufacturing the laminated film Y shown in FIG. 3, an adhesion layer 21 is formed on the HC layer 12 in the sputtering chamber 60a, a high refractive index layer 22a is formed on the adhesion layer 21 in the sputtering chamber 60b, a low refractive index layer 22b is formed on the high refractive index layer 22a in the sputtering chamber 60c, a high refractive index layer 22c is formed on the low refractive index layer 22b in the sputtering chamber 60d, and a high refractive index layer 22d is formed on the high refractive index layer 22c in the sputtering chamber 60e.

[0081] In the apparatus Z, after the plasma treatment step and the film-forming step, the laminated film Y as the work film W passes through the connection chambers C5 and C6 and reaches the winding chamber R2, and is wound by the winding roller 52.

[0082] In this way, a long laminated film Y can be manufactured.

Example

[0083] The present invention will be specifically described below with reference to examples. However, the present invention is not limited to the examples. Also, the specific numerical values such as the compounding amounts (contents), physical property values, parameters, etc. described below can be replaced with the upper limits (numerical values defined as "below" or "less than") or lower limits (numerical values defined as "above" or "exceeding") of the corresponding compounding amounts (contents), physical property values, parameters, etc. described in the above "Mode for Carrying Out the Invention".

[0084] [Example 1] The following steps were sequentially carried out to produce the hard coat film of Example 1.

[0085] First, a hard coat layer was formed on one side of a triacetyl cellulose (TAC) film as a base film (HC layer forming step). Specifically, first, 100 parts by mass (solid content conversion value) of a butyl acetate solution of an ultraviolet curable acrylic urethane resin (product name "Lucidiane 17-806", solid content concentration 80% by mass, manufactured by DIC Corporation), 5 parts by mass of a photopolymerization initiator (product name "Omnirad 907", manufactured by IGM Resins), 0.03 parts by mass of a leveling agent (product name "GRANDIC PC4100", manufactured by DIC Corporation), and butyl acetate as a solvent were mixed to prepare a first resin composition having a solid content concentration of 75% by mass. Next, cyclopentanone was added to the first resin composition as a further solvent to prepare a second resin composition having a solid content concentration of 50% by mass. On the other hand, a long TAC film (length 100 m, width 340 mm, thickness 40 μm) was prepared. Next, the second resin composition was applied to one side of the TAC film to form a coating film. Next, this coating film was dried by heating and then cured by ultraviolet irradiation. As a result, a hard coat (HC) layer having a thickness of 5 μm was formed on the TAC film. The heating temperature was 100 °C and the heating time was 60 seconds. In the ultraviolet irradiation, a high-pressure mercury lamp was used as a light source, and ultraviolet rays having a wavelength of 365 nm were irradiated onto the coating film, and the integrated irradiation light amount was 300 mJ / cm 2 Thus, a roll of TAC film with an HC layer was produced as a hard coat film (before plasma treatment).

[0086] Next, while conveying the substrate film with an HC layer in a roll-to-roll manner under vacuum, plasma treatment was performed on the hard coat film (plasma treatment step). In this step, an apparatus (first apparatus) capable of performing a roll-to-roll process on the work film was used. The first apparatus includes an unwinding chamber, a plasma treatment chamber, a film forming chamber, and a winding chamber. The unwinding chamber, the plasma treatment chamber (first plasma treatment), the film forming chamber, and the winding chamber are arranged in this order and communicate with each other. The unwinding chamber is provided with unwinding rollers. A roll of the hard coat film was set as the work film on the unwinding rollers. The plasma treatment chamber includes conveyance rollers with a temperature adjustment function (conveyance roller 53 in FIG. 5) and four low-inductance antennas (LA71 in FIGS. 6 and 7) covered with a cover block (cover block 73 in FIG. 7) as shown in FIGS. 6 and 7. Each low-inductance antenna has an extension portion (extension portion 71a in FIG. 6) parallel to the substrate film. In the four low-inductance antennas, the extension length d1 is 88 mm, the maximum length d2 (length of the extension portion) is 100 mm, the separation distance d3 is 112 mm, the center-to-center distance d4 is 290 mm, and the center-to-center distance d5 is 280 mm (FIGS. 6 and 7). Each low-inductance antenna is electrically connected to a high-frequency power source (RF power source, frequency 13.56 MHz) via an impedance matcher outside the plasma treatment chamber. The separation distance d' between the substrate film traveling in the plasma treatment chamber and the cover block is 100 mm. The film forming chamber is a sputtering film forming chamber and includes a film forming roller and a cathode arranged opposite to the film forming roller. The winding chamber is provided with winding rollers.

[0087] Specifically, in this step, while conveying the hard coat film in a roll-to-roll manner from the unwinding chamber to the winding chamber, plasma treatment was performed on the surface of the HC layer of the hard coat film in the plasma treatment chamber (plasma treatment step). The running speed of the hard coat film (film running speed) was set to 1.0 m / min. The temperature of the conveyance rollers with a temperature adjustment function was set to -8°C. The conditions for the plasma treatment are as follows.

[0088] The inside of the apparatus was evacuated to a vacuum until the ultimate vacuum of the plasma processing chamber reached 1.0×10 -4 Pa, and then oxygen gas was introduced into the plasma processing chamber to set the atmospheric pressure in the plasma processing chamber to 0.5 Pa. By applying 5.0 kW of high-frequency power to the four low-inductance antennas using a high-frequency power supply, an inductively coupled plasma of an oxygen-containing gas was formed around the antennas (the surface of the HC layer of the hard coat film was processed by this plasma).

[0089] The hard coat film of Example 1 was produced as described above. The hard coat film of Example 1 includes a base film and an HC layer on the base film. The surface of the HC layer of the hard coat film of Example 1 is plasma-treated. This plasma treatment is a treatment by inductively coupled plasma using an oxygen-containing gas generated by applying high-frequency power to a low-inductance antenna (oxygen-LAICP treatment).

[0090] [Comparative Example 1] A hard coat film of Comparative Example 1 (TAC film / HC layer) was produced in the same manner as the hard coat film of Example 1, except that the above plasma treatment was not performed. The surface of the HC layer of the hard coat film of Comparative Example 1 is not plasma-treated.

[0091] [Comparative Example 2] First, an HC layer was formed on one side of a TAC film in the same manner as in the HC layer formation step in Example 1. Thereby, a roll of a base film with an HC layer was obtained as a hard coat film (before plasma treatment).

[0092] Next, while transporting the hard coat film in a roll-to-roll manner under vacuum, plasma treatment was performed on the hard coat film (plasma treatment step). In this step, a second apparatus capable of performing a roll-to-roll process on the work film was used. The second apparatus has the same configuration as the first apparatus, except that it is provided with a second plasma treatment chamber instead of the first plasma treatment chamber. The second plasma treatment chamber includes a cathode electrode and an anode electrode (both are rectangular electrodes made of SUS304) as a pair of planar electrodes for plasma generation. The pair of planar electrodes are arranged in parallel with respect to the base material film passing through the second plasma treatment chamber with a spacing of 50 mm. The anode electrode is arranged at a position 35 mm away from the base material film passing through the second plasma treatment chamber and is grounded outside the second plasma treatment chamber. The cathode electrode is arranged so as to face the surface of the HC layer of the base material film and is electrically connected to a high-frequency power source (RF power source, 13.56 MHz) via an impedance matcher. The length of each electrode facing the base material film in the film running direction is 110 mm, and the length in the width direction is 430 mm.

[0093] In this step, specifically, while transporting the hard coat film in a roll-to-roll manner from the pay-off chamber to the take-up chamber, plasma treatment (bombardment treatment) was performed on the surface of the HC layer of the hard coat film in the second plasma treatment chamber. The running speed of the base material film (film running speed) was set to 1.0 m / min. The conditions for the plasma treatment are as follows.

[0094] After evacuating the inside of the apparatus until the ultimate vacuum degree of the second plasma treatment chamber reaches 1.0×10 -4 Pa, argon was introduced into the second plasma treatment chamber, and the pressure in the plasma treatment chamber was set to 0.5 Pa. By applying a power of 550 W to the space between the planar electrodes with a high-frequency power source, capacitively coupled plasma (CCP) was generated. In this plasma environment, bombardment treatment (Ar-BB treatment) with argon ions was performed on the surface of the HC layer of the hard coat film.

[0095] In the above manner, the hard coat film of Comparative Example 2 was produced. The surface of the HC layer of the hard coat film of Comparative Example 2 is plasma-treated. This plasma treatment is an ion bombardment treatment (Ar-BB treatment) using capacitively coupled plasma with argon gas.

[0096] 〈Surface properties〉 Regarding the hard coat films of Example 1 and Comparative Examples 1 and 2, the surface properties of the surface of the HC layer were examined. Specifically, first, the exposed surface of the HC layer in the hard coat film was observed and imaged using an atomic force microscope (product name "Dimention Edge SPC-160113-01", manufactured by Bruker). In the observation, the measurement mode was the tapping mode, and an antimony-doped Si cantilever (product name "RTESP-300", manufactured by Bruker) was used as the probe. Next, from the observation image of 1 μm square, the surface roughness (arithmetic mean height based on ISO 25178-2:2012) Sa of the surface of the HC layer was determined. The surface roughness Sa is shown in Table 1.

[0097] 〈Surface free energy〉 Regarding the hard coat films of Example 1 and Comparative Examples 1 and 2, the surface free energy of the surface of the HC layer was determined as follows.

[0098] First, a sample film of a predetermined size was cut out from the hard coat film. Next, the sample film was placed on a horizontally arranged slide glass. Specifically, the sample film was placed on the slide glass such that the HC layer surface in the sample film faced upward. Next, 2 μL of a predetermined liquid was dropped onto the HC layer surface of the sample film on the slide glass to form a liquid droplet in an atmosphere of 23°C and a relative humidity of 50% (formation of the liquid droplet). Next, the contact angle of the liquid droplet with respect to the sample film surface (HC layer surface) was measured using a contact angle meter (product name "DMs-401", manufactured by Kyowa Interface Science Co., Ltd.) (measurement of the contact angle). As the liquid, water (H2O), methylene iodide (CH2I2), and 1-bromonaphthalene were used. For each liquid, a series of operations including the formation of the liquid droplet and subsequent measurement of the contact angle were performed 5 times. The measurement was carried out within 24 hours after the production of the hard coat film. The average of the 5 measurement values for each liquid was taken as the contact angle for that liquid. In the above manner, the contact angle θw of water, the contact angle θi of methylene iodide, and the contact angle θb of 1-bromonaphthalene in the sample film were obtained.

[0099] Next, for each sample film, by solving the simultaneous ternary equations in the Kitazaki-Hata theory using the values of the contact angle θw of water, the contact angle θi of methylene iodide, and the contact angle θb of 1-bromonaphthalene, γ in the formula γ = γ d +γ p +γ h for γ d , γ p , γ h was derived. The Kitazaki-Hata theory is described, for example, in Vol. 8, No. 3, p. 131-141 (1972) of the Journal of the Adhesion Society of Japan. γ d in the formula is the dispersive component of the surface free energy, γ p is the polar component of the surface free energy, and γ h is the hydrogen bond component of the surface free energy. And γ d , γ p , γ hThe value (γ) obtained by summing them was determined as the surface free energy of the surface of the HC layer of the sample film. As the values necessary for the derivation, the dispersion component γ d in the surface free energy of water was taken as 29.1 mN / m, and the polar component γ p was taken as 1.3 mN / m, and the hydrogen bond component γ h was taken as 42.4 mN / m. The dispersion component γ d in the surface free energy of methylene iodide was taken as 46.8 mN / m, and the polar component γ p was taken as 4.0 mN / m, and the hydrogen bond component γ h was taken as 0.0 mN / m. The dispersion component γ d in the surface free energy of 1-bromonaphthalene was taken as 44.4 mN / m, and the polar component γ p was taken as 0.1 mN / m, and the hydrogen bond component γ h was taken as 0.0 mN / m. The surface free energy (mN / m) of the surface of the HC layer in the sample film is shown in Table 1.

[0100] 〈Softening Temperature of HC Layer Surface〉 For each of the hard coat films of Example 1 and Comparative Examples 1 and 2, the softening temperature of the surface of the HC layer was measured as follows (First Measurement).

[0101] First, a measurement sample was prepared. Specifically, first, a film piece of a predetermined size was cut out from the hard coat film. Next, the base film side (the side opposite to the HC layer surface) of the film piece was attached to a plate via a strong adhesive. Thereby, a measurement sample was obtained.

[0102] Next, a measurement sample was set on the measurement table of a nano-thermal analyzer (product name: "AFM5300 / NanoTA-2", manufactured by Hitachi High-Tech Sciences Corporation). The surface of the HC layer in the measurement sample on the measurement table was exposed upward. Then, nano-thermal analysis was performed using the nano-thermal analyzer. In this analysis, a cantilever (product name: "AN2-300", manufactured by Hitachi High-Tech Sciences Corporation) was used as a probe to press against the surface of the HC layer of the measurement sample. Also, the measurement mode was set to the nano-TA mode, and the measurement range was set to 8 μm square. This analysis was repeated a plurality of times for one cycle including the following Steps 1 and 2.

[0103] Step 1: As shown in FIG. 8, the tip Pa of the cantilever P (probe) was brought into contact with the surface (12a) of the HC layer (12).

[0104] Step 2: The temperature of the cantilever P (including the tip Pa) was raised from room temperature at a rate of 5 °C / second. When the set temperature t (°C) was reached, the cantilever P was separated from the surface simultaneously.

[0105] In the first cycle, a temperature that was considered to be significantly lower than the softening temperature of the HC layer surface was set as the set temperature t. For each cycle (Steps 1 and 2), the contact location of the cantilever with the HC layer surface (Step 1) was changed, and the set temperature t (Step 2) was increased by 2 °C. In the last cycle, a temperature that was considered to be significantly higher than the softening temperature of the HC layer surface was set as the set temperature t. In Step 2, the portion where the tip Pa of the cantilever P was in contact with the surface 12a of the HC layer 12 was locally heated and expanded. When the set temperature t was lower than the softening temperature of the surface 12a, the tip Pa did not penetrate the surface 12a. When the set temperature t was equal to or higher than the softening temperature of the surface 12a, the tip Pa penetrated the surface 12a.

[0106] Next, the surface of the HC layer was observed with a nano-thermal analyzer, and the presence or absence of indentation marks of the cantilever was confirmed for each cantilever contact site. When indentation marks were observed at the cantilever contact sites in three consecutive cycles on the surface of the HC layer, the lowest set temperature t in these three cycles was defined as the softening point temperature. The softening temperature measured in this way is shown in Table 1 as the softening temperature T1 (°C) of the HC layer surface.

[0107] For each of the hard coat films of Example 1 and Comparative Examples 1 and 2, the softening temperature of the HC layer surface after the following plasma treatment test was measured (Second measurement). The measured softening temperature is shown in Table 1 as the softening temperature T2 (°C) of the HC layer surface after the plasma treatment test. The difference (T2 - T1) between the softening temperature T2 and the softening temperature T1 is also shown in Table 1.

[0108] Plasma treatment test: The surface of the hard coat layer was treated with inductively coupled plasma of oxygen gas generated by applying high-frequency power of 13.56 MHz and 5.0 kW to a low-inductance antenna. This plasma treatment was carried out under the same conditions in the same plasma treatment chamber as the plasma treatment step described above for Example 1.

[0109] <Adhesion> After forming an inorganic layer on each of the hard coat films of Example 1 and Comparative Examples 1 and 2 to obtain a laminated film, the following First Test and Second Test were carried out to examine the adhesion of the inorganic layer.

[0110] In the formation of the inorganic layer, an apparatus equipped with a sputtering film deposition chamber capable of performing sputtering film deposition in a roll-to-roll manner was used. The sputtering film deposition chamber includes a film deposition roller (film deposition roller 54 in FIG. 5) and first and second sputtering chambers (sputtering chambers 60a and 60b in FIG. 5). Each sputtering chamber is a space partitioned within the film deposition chamber. The first and second sputtering chambers are arranged in this order in the traveling direction of the base material film along the circumferential direction of the film deposition roller. Each sputtering chamber includes a cathode disposed opposite to the film deposition roller. A required number of second lines (not shown) with flow rate control valves for introducing gas into the chamber are connected to each sputtering chamber.

[0111] In the formation of the inorganic layer on the hard coat film, first, while transporting the base material film while cooling it with the film deposition roller in the film deposition chamber, an adhesion layer was formed on the HC layer of the base material film in the first sputtering chamber, and an inorganic layer was formed on the adhesion layer in the second sputtering chamber. The film deposition temperature (temperature of the film deposition roller) was set to -8°C. More specifically, it is as follows.

[0112] In the first sputtering chamber, an ITO layer with a thickness of 5 nm was formed as an adhesion layer by sputtering (adhesion layer formation step). In this step, the ultimate vacuum degree in the film deposition chamber was 1.0×10 -4After evacuating to a vacuum up to Pa, argon as an inert gas was introduced into the first sputtering chamber, and the pressure in the first sputtering chamber was set to 0.3 Pa. As the target, a sintered body of indium oxide and tin oxide (ITO with a tin oxide concentration of 10% by mass) was used. As the power supply for applying voltage to the target, a DC power supply was used. The discharge power was set to 1.0 kW. In the second sputtering chamber, a SiO2 layer with a thickness of 20 nm was formed by reactive sputtering. In this process, after evacuating the film formation chamber to a vacuum as described above, 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 0.3 Pa. The oxygen introduction amount per 100 volume parts of argon introduced into the second sputtering chamber was set to 30 volume parts. As the target, a Si target was used. As the power supply for applying voltage to the target, an MF-AC power supply (60 kHz) was used. The discharge power was set to 3.0 kW. After forming the inorganic layer on the hard coat film as described above, the following first test and second test were carried out.

[0113] First Test: First, the side of the base film in the laminated film was fixed to a glass plate. Next, the inorganic layer of the laminated film on the glass plate was irradiated with light for 32.5 hours by a metal halide lamp under the conditions of a temperature of 85 °C, a relative humidity of 45%, and an irradiation intensity (integrated illuminance of 290 to 450 nm) of 150 mW / cm 2 (accelerated weather resistance test). This test was carried out using the "Eye Super UV Tester SUV-W161" manufactured by Iwasaki Electric Co., Ltd.

[0114] Second Test: First, with respect to the inorganic layer in the laminated film on the glass plate after the first test, 11 parallel first cuts (at 1 mm intervals) linearly extending in the first direction and 11 parallel second cuts (at 1 mm intervals) linearly extending in the second direction orthogonal to the first direction were formed using a cutter knife, and 100 meshes were formed by the first and second cuts. Next, while continuously dropping isopropyl alcohol at 2 mL / min onto the regions of the 100 meshes in the laminated film, a polyester wiper (product name "Anticon Gold", manufactured by Sampratech Co., Ltd.) was slid under the conditions of a wiper contact surface of 20 mm × 20 mm, a load of 1.5 kg / 20 mm□, a sliding speed of 50 mm / second, and 1000 reciprocations. Next, among the 100 meshes, the number of meshes where peeling of 0.25 mm 2 or more occurred was counted. Next, the peeling rate (%) was calculated by dividing the count by 100.

[0115] And when the peeling rate was 5% or less, it was evaluated as "good", and when the peeling rate exceeded 5%, it was evaluated as "bad". The results are shown in Table 1.

[0116] [Evaluation] In the hard coat film of Comparative Example 1, since the HC layer does not contain particles, the surface of the HC layer does not have irregularities caused by particles. In the manufacturing process of the hard coat film of Comparative Example 1, the surface of the HC layer is not plasma-treated. The surface roughness Sa of the HC layer of such a hard coat film of Comparative Example 1 is 0.35 nm, which is significantly lower than 0.80 nm. Also, in the hard coat film of Comparative Example 1, the HC layer is a cured product layer of a composition containing an ultraviolet curable resin, and the difference in the softening temperature (T2 - T1) of the surface of the HC layer is 32 °C, which is much higher than 5 °C. That is, the HC layer in Comparative Example 1 has a fragile thin layer on the surface and in its vicinity. Therefore, in the hard coat film of Comparative Example 1, the adhesion of the inorganic layer could not be ensured.

[0117] In the hard coat film of Comparative Example 2, since the HC layer does not contain particles, the surface of the HC layer has no irregularities caused by the particles. In the manufacturing process of the hard coat film of Comparative Example 2, the surface of the HC layer is subjected to bombardment treatment with argon ions (Ar-BB treatment). The surface roughness Sa of the HC layer of such a hard coat film of Comparative Example 2 is 0.32 nm, which is significantly lower than 0.80 nm. Further, in the hard coat film of Comparative Example 2, the HC layer is a cured product layer of a composition containing an ultraviolet curable resin, and the difference in softening temperature (T2 - T1) of the surface of the HC layer is 16 °C, which is much higher than 5 °C. That is, the HC layer in Comparative Example 2 has a fragile thin layer on the surface and in its vicinity. Therefore, in the hard coat film of Comparative Example 2, the adhesion of the inorganic layer could not be ensured.

[0118] In the hard coat film of Example 1, since the HC layer of the base film does not contain particles, the surface of the HC layer has no irregularities caused by the particles. However, in the manufacturing process of the hard coat film of Example 1, the surface of the HC layer is subjected to treatment with inductively coupled plasma using an oxygen-containing gas (oxygen-LAICP treatment) generated by applying high-frequency power to a low inductance antenna. According to the oxygen-LAICP treatment, compared with the Ar-BB treatment, the surface of the HC layer can be roughened with fine irregularities on the nanometer order. In addition, according to the oxygen-LAICP treatment, the fragile thin layer on the surface of the HC layer can be effectively removed. This is shown by the fact that the difference in softening temperature (T2 - T1) of the surface of the HC layer in Example 1 is 5 °C or less. Therefore, in the hard coat film of Example 1, the adhesion of the inorganic layer could be ensured.

[0119]

Table 1

Explanation of Signs

[0120] X Hard coat film Y Laminated film H Thickness direction D Plane direction 11 Base film 12 Hard coat layer (HC layer) 12a Surface 20 Inorganic layer 21 Adhesion layer 22a, 22c High refractive index layer 22b, 22d Low refractive index layer

Claims

1. A hard coat film comprising a base film and a hard coat layer on the base film, wherein the hard coat layer is a cured product layer of a composition containing an ultraviolet curable resin, the surface roughness Sa of the surface of the hard coat layer on the side opposite to the base film is 0.80 nm or more and 4.50 nm or less, the softening temperature of the surface of the hard coat layer is T1, the difference between the softening temperature T2 after the following plasma treatment test of the surface and the softening temperature T1 is 5°C or less, the surface is a treated surface by inductively coupled plasma using an oxygen-containing gas generated by applying high-frequency power to a low-inductance antenna, the hard coat film. Plasma treatment test: The surface of the hard coat layer is treated with inductively coupled plasma of oxygen gas generated by applying high-frequency power of 13.56 MHz and 5.0 kW to a low-inductance antenna.

2. The hard coat film according to claim 1, wherein the ultraviolet curable resin is at least one selected from the group consisting of an ultraviolet curable acrylate urethane resin and an ultraviolet curable acrylic resin.

3. The hard coat film according to claim 1, wherein the softening temperature T1 is 105°C or more.

4. The hard coat film according to claim 1, wherein the softening temperature T1 is 150°C or less.

5. A laminated film comprising the hard coat film according to any one of claims 1 to 4, and an inorganic layer on the hard coat layer of the hard coat film.

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