Laminate, optical member with laminate, and image display device

Abstract

To provide a laminate capable of achieving excellent sliding properties regardless of whether or not a user's finger is wet with sweat, an optical member with a laminate, and an image display device.SOLUTION: A laminate according to an embodiment of the present invention is provided with a substrate and a function layer arranged on one side in a thickness direction of the substrate. In a specific friction test carried out through Bowden surface contact, both a static friction coefficient and a dynamic friction coefficient on a surface of the function layer are 0.13 or less as measured using a contact element wet with synthetic sweat defined by JIS L 0848.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a laminate, an optical member with the laminate, and an image display device. [Background technology]

[0002] Image display devices that also function as touch panel input devices, such as smartphones and tablet personal computers (PCs), are becoming increasingly popular. Such image display devices typically use laminates containing functional layers tailored to their intended use. Known examples of such laminates include hard-coated films in which a hard-coat layer is provided on one side of a transparent substrate film (see, for example, Patent Document 1). In recent years, the environments in which image display devices that also function as touch panel input devices are used have become more diverse. For example, a smartphone may be used while playing sports, and the user may operate the smartphone with sweaty fingers. However, when the hard coat film described in Patent Document 1 is used as the front panel of an image display device, there is a limit to the improvement in finger slipperiness, whether the user's fingers are wet with sweat or not, and there is a risk that the operability of the image display device will be insufficient. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5157819 Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention has been made to solve the above-mentioned conventional problems, and its main object is to provide a laminate, an optical element with the laminate, and an image display device that can achieve excellent slipperiness whether the user's fingers are wet with sweat or not. [Means for solving the problem]

[0005] A laminate according to an embodiment of the present invention includes a substrate and a functional layer disposed on one side of the substrate in a thickness direction, and the functional layer has a surface whose static and dynamic friction coefficients are both 0.13 or less when measured using a contact point wetted with artificial sweat as specified in JIS L 0848 in a friction test using a surface contact according to the Bowden method described below. (Friction test) The laminate is set in an automatic friction and wear analysis device; in the first step, the contactor is brought into contact with the surface of the functional layer with a load of 200 g; in the second step, the contactor is moved 50 mm at a speed of 1.7 mm / s to measure the static friction force and dynamic friction force on the surface of the functional layer; in the third step, the contactor is separated from the surface of the functional layer and returned to its initial position; the first step, the second step, and the third step are repeated five times in sequence to calculate the static friction coefficient of the surface of the functional layer from the static friction force of the surface of the functional layer, and the dynamic friction coefficient of the surface of the functional layer from the dynamic friction force of the surface of the functional layer. In one embodiment, the laminate has an absolute value of surface force of 110 μN or less as measured by the following surface force test. (surface strength test) The laminate is placed in a surface force measuring device equipped with a probe having a surface layer formed from polydimethylsiloxane; the probe is placed in its initial position and the surface of the functional layer is brought into contact with the surface layer. When the probe comes into contact with the functional layer, in the case of a highly adhesive substance such as polydimethylsiloxane, a phenomenon (wetting) occurs in which the probe is pulled downward upon contact. The point at which this wetting occurs is used as the criterion for determining whether the sample and the probe have come into contact. Next, the amount of probe pull-in displacement is set to zero, and the probe is then moved in a direction away from the laminate. The absolute value of the surface force of the laminate is calculated from the minimum value of the load applied to the probe when the surface layer separates from the surface of the functional layer. In one embodiment, the carbon element ratio at the surface of the functional layer is 50 atomic % or less, and the fluorine element ratio at the surface of the functional layer is 30 atomic % or more. In one embodiment, in a C1s spectrum measured by X-ray photoelectron spectroscopy of the surface of the functional layer, the sum of the areas of the peaks located in the range of 293 eV to 295 eV is 30 area % or more of the sum of the areas of the peaks located in the range of 280 eV to 300 eV, and the area of ​​the peaks located in the range of 293 eV to 294 eV is 1.5 to 2.5% of the area of ​​the peaks located in the range of 294 eV to 295 eV. In one embodiment, the absolute value of the difference in the static friction coefficient before and after the sliding property test described below and the absolute value of the difference in the dynamic friction coefficient before and after the sliding property test described below are both 0.02 or less. (Sliding property test) The laminate is set in a sliding property testing device; the surface of the functional layer is wetted with the artificial sweat solution, and a contactor made of a rubber material is brought into contact with the surface of the functional layer with a load of 2 kg; and the contactor is then moved back and forth 1,000 times over a range of 50 mm at a speed of 66.7 mm / s. In one embodiment, the dynamic friction coefficient before the sliding property test is greater than the dynamic friction coefficient after the sliding property test. In one embodiment, the functional layer includes an anti-fingerprint layer located on the outermost surface of the functional layer, and the anti-fingerprint layer is made of a vapor-deposited film of a fluorine-containing silane compound. An optical member with a laminate according to another aspect of the present invention includes the laminate described above; and an optical member that is disposed on the opposite side of the substrate from the functional layer. An image display device according to yet another aspect of the present invention includes the above-described laminate as a front panel. [Effects of the Invention]

[0006] According to the embodiment of the present invention, excellent smoothness can be achieved whether the user's fingers are wet with sweat or not. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic cross-sectional view of a laminate according to one embodiment of the present invention. [Figure 2]FIG. 2 is a schematic cross-sectional view of a laminate according to another embodiment of the present invention. [Figure 3] FIG. 3 is an explanatory diagram for explaining the friction test. [Figure 4] Figures 4(a) to 4(c) are explanatory diagrams for explaining the surface force test, where Figure 4(a) shows the state in which the probe is placed in the initial position, Figure 4(b) shows the state in which the probe is moved upward from the initial position, and Figure 4(c) shows the state in which the surface layer of the probe is separated from the surface of the functional layer. [Figure 5] 5(a) and 5(b) are explanatory diagrams for explaining the sliding test, where FIG. 5(a) shows the state in which the contacts are moved back and forth, and FIG. 5(b) shows the friction test after the sliding test. [Figure 6] FIG. 6 is a graph showing the results (friction coefficient) of a friction test using dry contacts. [Figure 7] FIG. 7 is a graph showing the results (friction coefficient) of a friction test using contacts wetted with artificial sweat. [Figure 8] FIG. 8 is a graph showing the difference in friction coefficient before and after the sliding property test using artificial sweat. DETAILED DESCRIPTION OF THE INVENTION

[0008] Representative embodiments of the present invention will be described below, but the present invention is not limited to these embodiments.

[0009] A. Overall structure of the laminate FIG. 1 is a schematic cross-sectional view of a laminate according to one embodiment of the present invention; FIG. 2 is a schematic cross-sectional view of a laminate according to another embodiment of the present invention; and FIG. 3 is an explanatory diagram for explaining a friction test. The illustrated laminate 1 includes a substrate 2 and a functional layer 3 disposed on one thickness-wise side of the substrate 2. A surface 3a of the functional layer 3 opposite the substrate 2 is located at the outermost surface of the laminate 1. In the laminate 1, the static friction coefficient and dynamic friction coefficient of the surface 3a of the functional layer measured using a contactor wetted with artificial sweat as specified in JIS L 0848 in the surface contact friction test using the Bowden method described below are both 0.13 or less, preferably 0.11 or less. (Friction test) The laminate 1 is set in an automatic friction and wear analyzer 4; in the first step, the contact 41 is brought into contact with the surface 3a of the functional layer under a load of 200 g; in the second step, the contact 41 is moved 50 mm at a speed of 1.7 mm / s to measure the static friction force and dynamic friction force of the surface 3a of the functional layer; in the third step, the contact 41 is separated from the surface 3a of the functional layer and returned to its initial position; the first step, the second step, and the third step are repeated five times in order to calculate the static friction coefficient of the surface 3a of the functional layer from the static friction force of the surface 3a of the functional layer, and calculate the dynamic friction coefficient of the surface 3a of the functional layer from the dynamic friction force of the surface 3a of the functional layer. Details of the friction test will be explained in the examples below. In such a laminate, the static friction coefficient (hereinafter, μs ) of the surface of the functional layer measured using a contactor wetted with artificial sweat in the above friction test is *人工汗液 ) and the coefficient of dynamic friction (hereinafter referred to as μk *人工汗液 ) are both below the upper limit. Therefore, excellent smoothness can be achieved even when the user's fingers are wet with sweat. *人工汗液 and μ *人工汗液 The lower limit of each of these is typically 0.05 or more.

[0010] In addition, typically, in the friction test, the static friction coefficient (hereinafter, μs *無 ) and the coefficient of dynamic friction (hereinafter referred to as μk *無 ) are both 0.15 or less, preferably 0.13 or less, and more preferably 0.11 or less. Therefore, excellent smoothness can be achieved even when the user's fingers are not wet with sweat. *無 and μ *無 The lower limit of each of these is typically 0.05 or more.

[0011] In one embodiment, μs *無 μs for *人工汗液 Ratio (μs *人工汗液 / μs *無 ) is, for example, 0.7 or more, preferably 0.8 or more, and for example, 1.2 or less, preferably 1.1 or less. *人工汗液 / μs *無 Within the above range, even if the user's fingers are wet with sweat, the same level of smoothness as when the fingers are not wet can be stably achieved. In one embodiment, μ *無 μk for *人工汗液 Ratio (μk *人工汗液 / μk *無 ) is, for example, 0.8 or more, preferably 0.9 or more, and for example, 1.3 or less, preferably 1.2 or less. *人工汗液 / μk *無 If is in the above range, even if the user's fingers are wet with sweat, smoothness equivalent to that when the fingers are not wet can be more stably achieved.

[0012] 4(a) to 4(c) are explanatory diagrams for explaining the surface force test. In one embodiment, the laminate 1 has an absolute value of surface force measured by the following surface force test of 110 μN or less, preferably 105 μN or less. (surface strength test) The laminate 1 is placed in a surface force measuring device 5 equipped with a probe 51 having a surface layer 51a formed from polydimethylsiloxane; the probe 51 is placed in an initial position and the surface layer 51a is brought into contact with the surface 3a of the functional layer; the probe 51 is then moved in a direction away from the laminate 1, and the absolute value of the surface force of the laminate is calculated from the minimum value of the load applied to the probe 51 when the surface layer 51a is separated from the surface 3a of the functional layer. Details of the surface force test will be explained in the examples below. If the surface force of the laminate 1 measured in the surface force test is equal to or greater than the lower limit, the static and dynamic friction coefficients of the surface of the functional layer can be stably adjusted to fall within the ranges described above. The absolute value of the surface force of the laminate is typically 80 μN or greater.

[0013] In one embodiment, the carbon element ratio at the surface 3a of the functional layer is 50 atomic % or less, preferably 40 atomic % or less, and the fluorine element ratio at the surface 3a of the functional layer is 30 atomic % or more. The element ratio at the surface of the functional layer can be measured by X-ray photoelectron spectroscopy (ESCA). Details of the element ratio measurement will be explained in the examples below. When the carbon element ratio at the surface 3a of the functional layer is equal to or less than the upper limit and the fluorine element ratio is equal to or greater than the lower limit, the static friction coefficient and the dynamic friction coefficient of the surface of the functional layer can be stably adjusted within the above-mentioned ranges. The carbon element ratio at the surface 3a of the functional layer is typically 20 atomic % or more, and the fluorine element ratio is typically 50 atomic % or less. Furthermore, the nitrogen element ratio on the surface 3a of the functional layer is, for example, less than 1.5 atomic %, preferably 1.3 atomic % or less, and for example, 0 atomic % or more. If the nitrogen element ratio on the surface 3a of the functional layer is not more than the above upper limit, the static friction coefficient and dynamic friction coefficient of the surface of the functional layer can be adjusted more stably within the above ranges.

[0014] In one embodiment, in a C1s spectrum measured by X-ray photoelectron spectroscopy of the surface 3a of the functional layer, the sum of the areas of peaks located in the range of 293 eV to 295 eV is 30% or more of the sum of the areas of peaks located in the range of 280 eV to 300 eV, and the area of ​​peaks located in the range of 293 eV to 294 eV is 1.5 to 2.5% of the area of ​​peaks located in the range of 294 eV to 295 eV. Details of the C1s spectrum waveform analysis will be described in the examples below. If the area ratio of the peak located in the range of 293 eV to 295 eV in the C1s spectrum is equal to or greater than the lower limit and the ratio of the area of ​​the peak from 293 eV to 294 eV to the area of ​​the peak from 294 eV to 295 eV is within the above range, the static friction coefficient and dynamic friction coefficient of the surface of the functional layer can be adjusted more stably within the above range. Note that the area ratio of the peak located in the range of 293 eV to 295 eV in the C1s spectrum is typically 80 atomic % or less.

[0015] 5(a) and 5(b) are explanatory diagrams for explaining the sliding property test. In one embodiment, the absolute value of the difference in the static friction coefficient before and after the sliding property test described below and the absolute value of the difference in the dynamic friction coefficient before and after the sliding property test described below are both 0.02 or less, preferably 0.01 or less. (Sliding property test) The laminate 1 is set in a sliding property testing device 6; the surface 3a of the functional layer is wetted with the above-mentioned artificial sweat, and a contactor 61 made of a rubber material is brought into contact with the surface 3a of the functional layer with a load of 2 kg; then, the contactor 61 is moved back and forth 1,000 times over a range of 50 mm at a speed of 66.7 mm / s. Thereafter, the contact 41 of the automatic friction and wear analysis device 4 is wetted with the artificial sweat, and the friction test is carried out. When the absolute value of the difference between the static friction coefficient before and after the sliding property test and the absolute value of the difference between the dynamic friction coefficient are not more than the above upper limit, excellent sliding properties of the surface of the functional layer can be sufficiently ensured even when the laminate is used and the surface of the functional layer is rubbed with a finger, etc. The absolute value of the difference between the static friction coefficient before and after the sliding property test and the absolute value of the difference between the dynamic friction coefficient are typically 0.0001 or more. Furthermore, the dynamic friction coefficient before the sliding property test is preferably larger than the dynamic friction coefficient after the sliding property test. With this configuration, the sliding property of the surface of the functional layer can be improved as the laminate is used.

[0016] B. Base material The substrate 2 may be made of any suitable transparent resin. Specific examples of transparent resins include polyethylene terephthalate resins, polyethylene naphthalate resins, acetate resins, polyethersulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyamideimide resins, polyolefin resins, (meth)acrylic resins, polyvinyl chloride resins, polyvinylidene chloride resins, polystyrene resins, polyvinyl alcohol resins, polyarylate resins, and polyphenylene sulfide resins. These resins may be used alone or in combination. Of the transparent resins, polyethylene terephthalate resins and polyimide resins are preferred. The thickness of the substrate 2 is, for example, 40 μm or more, preferably 50 μm or more, and for example, 100 μm or less, preferably 80 μm or less.

[0017] C. Functional Layer The functional layer 3 is provided appropriately depending on the performance required for the application of the laminate 1. The functional layer 3 is not particularly limited as long as the surface 3a of the functional layer 3 has the above-mentioned characteristics and / or configuration. Examples of the functional layer 3 include a hard coat layer, an anti-reflection layer, an anti-fingerprint layer, and a conductive layer. The functional layer 3 may be a single layer or may be configured by laminating multiple layers.

[0018] The functional layer 3 shown in FIG. 1 is a hard coat layer 31, and the surface of the hard coat layer 31 opposite to the substrate 2 corresponds to the surface 3a. The hard coat layer 31 is typically formed by applying a hard coat coating agent to form a coating layer and then irradiating the coating layer with active energy rays (e.g., ultraviolet rays) to cure it. The hard coat coating agent contains an active energy ray-curable (meth)acrylate as a base resin. Examples of the active energy ray-curable (meth)acrylate include an ultraviolet ray-curable (meth)acrylate and an electron beam-curable (meth)acrylate, and preferably an ultraviolet ray-curable (meth)acrylate. The ultraviolet ray-curable (meth)acrylate includes an ultraviolet ray-curable monomer, oligomer, polymer, etc. The ultraviolet ray-curable (meth)acrylate includes a monomer component and an oligomer component having preferably two or more, more preferably three to six, ultraviolet-polymerizable functional groups. Typically, the ultraviolet ray-curable (meth)acrylate contains a photopolymerization initiator. The curing method may be a radical polymerization method or a cationic polymerization method. In this specification, (meth)acrylate means acrylate and / or methacrylate.

[0019] The hard coat coating agent may further contain any appropriate additives depending on the purpose. Examples of additives include photopolymerization initiators, leveling agents, antiblocking agents, dispersion stabilizers, thixotropic agents, antioxidants, UV absorbers, antifoaming agents, thickeners, dispersants, surfactants, catalysts, fillers, lubricants, and antistatic agents. The types, combinations, and contents of the additives contained can be appropriately set depending on the purpose and desired properties. The irradiation dose (integrated light amount) of active energy rays (e.g., ultraviolet rays) is, for example, 150 mJ / cm 2 ~400mJ / cm 2 If necessary, the coating layer may be heated before being irradiated with active energy rays. The heating temperature is, for example, 70° C. to 160° C. The heating time is, for example, 1 minute to 4 minutes. The thickness of the hard coat layer is, for example, 3 μm or more and 20 μm or less.

[0020] The functional layer 3 shown in Figure 2 comprises a hard coat layer 31, an anti-reflection layer 32 arranged on the opposite side of the substrate 2 from the hard coat layer 31, and an anti-fingerprint layer 33 arranged on the opposite side of the substrate 2 from the anti-reflection layer 32, and the surface of the anti-fingerprint layer 33 opposite the anti-reflection layer 32 is located at the outermost surface of the functional layer 3 and corresponds to surface 3a of the functional layer 3.

[0021] Any appropriate configuration may be adopted as the configuration of the antireflection layer 32. Typical configurations of the antireflection layer 32 include: (1) a single layer of a low refractive index layer having an optical film thickness of 120 nm to 140 nm and a refractive index of about 1.35 to 1.55; (2) a laminate having a medium refractive index layer, a high refractive index layer, and a low refractive index layer; and (3) an alternating multilayer laminate of high refractive index layers and low refractive index layers.

[0022] Examples of materials that can form a low refractive index layer include silicon oxide (SiO2) and magnesium fluoride (MgF2). The refractive index of a low refractive index layer is typically about 1.35 to 1.55. Examples of materials that can form a high refractive index layer include titanium oxide (TiO2), niobium oxide (Nb2O3 or Nb2O5), tin-doped indium oxide (ITO), antimony-doped tin oxide (ATO), and ZrO2-TiO2. The refractive index of a high refractive index layer is typically about 1.60 to 2.20. Examples of materials that can form a medium refractive index layer include titanium oxide (TiO2) and a mixture of a material that can form a low refractive index layer and a material that can form a high refractive index layer (for example, a mixture of titanium oxide and silicon oxide). The refractive index of a medium refractive index layer is typically about 1.50 to 1.85. The thicknesses of the low refractive index layer, the medium refractive index layer and the high refractive index layer can be set so as to achieve an appropriate optical film thickness depending on the layer structure of the antireflection layer, the desired antireflection performance and the like.

[0023] The anti-reflection layer 32 is typically formed by a dry process. Specific examples of dry processes include PVD (Physical Vapor Deposition) and CVD (Chemical Vapor Deposition). PVD methods include vacuum deposition, reactive vapor deposition, ion beam assisted deposition, sputtering, and ion plating. CVD methods include plasma CVD. The dry process for forming the anti-reflection layer 32 is preferably sputtering. The thickness of the antireflection layer 32 is, for example, 20 nm to 300 nm.

[0024] Any appropriate configuration may be adopted for the anti-fingerprint layer 33. The anti-fingerprint layer 33 is typically made of a vapor-deposited film of a fluorine-containing silane compound. Examples of the fluorine-containing silane compound include an alkoxysilane compound having a perfluoropolyether group. The anti-fingerprint layer 33 is typically formed by the vapor deposition method described above, and is preferably formed by vacuum deposition. The anti-fingerprint layer 33 has a thickness of, for example, 1 nm to 50 nm.

[0025] D. Optical member with laminate and image display device The laminate described in the above items A to C can be used by being disposed on the viewing side of an optical member. Therefore, one embodiment of the present invention also includes an optical member with a laminate, which includes the laminate and an optical member. The optical member is disposed on the opposite side of the substrate from the functional layer. Typical examples of optical members include a polarizing plate and a retardation plate. Furthermore, such an optical member with a laminate can be applied to an image display device. Therefore, one embodiment of the present invention also includes an image display device using such an optical member with a laminate. The image display device typically doubles as a touch panel type input device. Typical examples of image display devices include liquid crystal display devices and organic EL display devices. The image display device according to the embodiment of the present invention typically includes the above-mentioned laminate as a front panel. The image display device includes an image display panel. The image display panel includes an image display cell. Note that the image display device may be referred to as an optical display device, the image display panel may be referred to as an optical display panel, and the image display cell may be referred to as an optical display cell. [Example]

[0026] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The methods for measuring each property are as follows.

[0027] (1) Friction test 3, the laminate 1 obtained in each example and comparative example was set in an automatic friction and wear analyzer 4 (manufactured by Kyowa Interface Science Co., Ltd., product name TSf-503, measurement method: surface contact by Bowden method). More specifically, the laminate 1 was placed horizontally on a stage (not shown) of the automatic friction and wear analyzer 4 so that the surface 3a of the functional layer was facing upward. Next, the contact 41 (Anticon, manufactured by CONTEC, product name Anticon Gold Supersorb 9-inch square bulk pack (AP)) of the automatic friction and wear analyzer 4 was either soaked with 64 μL of artificial sweat as specified in JIS L 0848, or was left in a dry state without being soaked with artificial sweat (No in Table 1). The material of the contact 41 was polyester fiber, and the density of the contact 41 was 23.5 g / cm. 3 The size of the contact 41 was 1 cm in length, 1 cm in width, and 0.56 mm in thickness. Next, in the first step, the contactor 41 (either the contactor 41 wetted with artificial sweat or the dry contactor 41) was brought into contact with the surface 3a of the functional layer under a load of 200 g. More specifically, the contactor 41 was held by a holder 42 of the automatic friction and wear analysis device 4, and sandwiched between the holder 42 and the surface 3a of the functional layer, and the holder 42 pressed the contactor 41 against the surface 3a of the functional layer under the above load. Next, in the second step, the contactor 41 was pressed against the surface 3a of the functional layer and moved 50 mm in the long side direction of the laminate 1 at a speed of 1.7 mm / s to measure the static friction force and dynamic friction force of the surface 3a of the functional layer. Next, in the third step, the holder 42 was moved upward to separate the contact 41 from the surface 3a of the functional layer, and returned to the initial position before the first step. Then, the first, second and third steps were repeated five times in sequence, and the static friction coefficient μs of the functional layer surface 3a was calculated from the average value of the static friction force of the functional layer surface 3a measured in the second step, and the dynamic friction coefficient μk of the functional layer surface 3a was calculated from the average value of the dynamic friction force of the functional layer surface measured in the second step. In addition, the maximum friction coefficient μk max and the minimum friction coefficient μk min Calculate the maximum friction coefficient μk max and the minimum friction coefficient μk min The difference μkw was calculated. In addition, the static friction coefficient μs when using dry contacts *無 The static friction coefficient μs when using a contactor wetted with artificial sweat *人工汗液and the dynamic friction coefficient μk when using dry contacts *無 The dynamic friction coefficient μk when using a contactor wetted with artificial sweat *人工汗液 The ratios were calculated, and the results are shown in Table 1. Furthermore, the friction test results (μs, μk, μk max , μ min and μkw) when dry contacts are used is shown in Figure 6, and when contacts wetted with artificial sweat are shown in Figure 7. The environmental conditions for the friction test were 30°C and 50% RH.

[0028] (2) Surface strength test As shown in FIG. 4, the laminate 1 obtained in each example and comparative example was set in a surface force measurement apparatus 5 (manufactured by ELIONIX, product name ENT-NEXUS). Specifically, the laminate 1 was placed horizontally on a stage 52 of the surface force measurement apparatus 5, with the surface 3a of the functional layer facing upward. The surface force measurement apparatus 5 is equipped with a probe 51 having a surface layer 51a formed from polydimethylsiloxane (PDMS). The probe 51 is movable in the vertical direction. The probe 51 was prepared by ultrasonically cleaning a 1 mm diameter metal sphere (SUJ2) in an organic solvent (acetone) for 10 minutes, rinsing it with pure water, ultrasonically cleaning it in a neutral detergent solution for 10 minutes, and rinsing it with pure water, in that order. Then, a one-component, solvent-free, dealcohol-free silicone adhesive (manufactured by ThreeBond, a silicone adhesive sealant for electrical and electronic applications) made of polydimethylsiloxane was applied to the surface of the metal sphere. The surface layer 51a has elasticity, and the tensile strength E' of the surface layer 51a is 2.2 MPa, and the hardness (durometer A) F' of the surface layer 51a is 20. The thickness of the surface layer 51a is 1 μm. Next, as shown in FIG. 4(a), the probe 51 was placed at the initial position, and the surface 3a of the functional layer was brought into contact with the surface layer 51a without applying substantially any load. Next, as shown in Figures 4(b) and 4(c), the probe 51 was moved in a direction away from the laminate 1 (specifically, upward) at a speed of 50 μN / s, and the absolute value of the surface force was calculated from the minimum value of the load applied to the probe 51 when the surface layer 51a separated from the surface 3a of the functional layer. The above surface force test was repeated three times (n1 to n3). The results are shown in Table 2. The environmental conditions for the surface strength test were 30°C and 50% RH.

[0029] (3) Quantitative measurement of functional groups The laminate 1 obtained in each example and each comparative example was cut into 10 mm squares and fixed to a scanning X-ray photoelectron spectrometer (manufactured by ULVAC-PHI, trade name Quantum 2000), and then wide scan measurement of the outermost surface of the sample (X-ray source: monochrome AlKα, X-ray setting: 200 μmφ [15 kV, 30 W], photoelectron take-off angle: 45 degrees to the sample surface, bond energy correction: C1s spectrum C C bond derived peak corrected to 285.0 eV, neutralization conditions: neutralization gun and Ar ion gun (neutralization mode) used in combination) was performed, and qualitative analysis was performed. In addition, for the elements shown in Table 2, narrow scan measurement was performed under the same conditions as the wide scan measurement, and the element ratio (atomic%) was calculated. The above quantitative measurement of functional groups was repeated twice (n1 and n2), and the results are shown in Table 2.

[0030] (4) C1s spectrum waveform analysis The C1s spectrum calculated in (3) above was subjected to waveform analysis using the peaks shown in Table 2. In the obtained C1s spectrum, peaks 1 to 7 shown in Table 2 were confirmed in the binding energy range of 280 eV to 300 eV. Based on the binding energy values, the constituent functional group components corresponding to peaks 1 to 7 were identified as shown in Table 2. Table 2 also shows the area percentage of each peak relative to the total area of ​​the peaks located in the range of 280 eV to 300 eV (the total area of ​​peaks 1 to 7), and the area ratio of peak 6 to the area of ​​peak 7.

[0031] (5) Sliding test As shown in FIG. 5(a), the laminate 1 obtained in each example and comparative example after the above-described friction test was set in a sliding property tester 6 (manufactured by Ogawa Seiki Co., Ltd., product name: 10-pen tester). Specifically, the laminate 1 was placed horizontally on a stage (not shown) of the sliding property tester 6, with the surface 3a of the functional layer facing upward. The sliding property tester 6 includes a contact 61 (manufactured by Minoan Co., Ltd., product name: RUBBER STICK, product code: 4004005007) made of a rubber material and a holder 62 for holding the contact 61. Next, the surface 3a of the functional layer was wetted with the artificial sweat, and the contact 61 was brought into contact with the surface 3a of the functional layer with a load of 2 kg. Next, the contactor 61 was pressed against the surface 3a of the functional layer and moved back and forth 1000 times over a range of 50 mm at a speed of 66.7 mm / s in the long side direction of the laminate 1. The environmental conditions for the sliding property test were 25°C and 50% RH. Next, as shown in FIG. 5(b), the laminate 1 after the sliding test was set in the automatic friction and wear analyzer 4 so that the contact 41 was in contact with the sliding trace 61a, and the static friction coefficient μs, dynamic friction coefficient μk, and maximum friction coefficient μk of the surface 3a of the functional layer after the sliding test were measured in the same manner as in the above friction test. max and the minimum friction coefficient μk min The difference in static friction coefficient Δμs, the difference in dynamic friction coefficient Δμk, and the difference in maximum friction coefficient Δμk before and after the sliding test were calculated. max , the difference in minimum friction coefficient Δμk min and Δμkw are shown in Table 3. In addition, the friction test results (Δμs, Δμk, Δμk max , Δμk min and Δμkw) are shown in Figure 8.

[0032] [Example 1] <Preparation of Coating Agent A for Hard Coating> 100 parts by mass of a multifunctional acrylate (manufactured by Aica Kogyo Co., Ltd., product name Z-850-27ALL) as a base resin, 0.5 parts by mass of a leveling agent (manufactured by DIC Corporation, product name GRANDIC PC-4100), and 3.9 parts by mass of a photopolymerization initiator (manufactured by Ciba Japan Co., Ltd., product name Irgacure 907) were mixed and diluted with methyl isobutyl ketone to a solids concentration of 40% by mass, thereby preparing coating agent A for hard coating. <Preparation of Coating Agent B for Hard Coat> 100 parts by mass of a multifunctional acrylate (manufactured by Aica Kogyo Co., Ltd., product name Z-850-16ALL) as a base resin, 0.15 parts by mass of a leveling agent (manufactured by Shin-Etsu Chemical Co., Ltd., product name KY-1203), and 3 parts by mass of a photopolymerization initiator (manufactured by Ciba Japan Co., Ltd., product name Irgacure 127) were mixed and diluted with methyl isobutyl ketone to a solids concentration of 50% by mass, thereby preparing coating agent B for hard coating. <Preparation of laminate> Coating agent A was applied to one side of a transparent polyimide film (manufactured by KOLON, product name CPITMC_80, thickness 80 μm) used as a substrate to form a coating layer, and the coating layer was heated together with the transparent polyimide film at 120°C for 1 minute. Next, ultraviolet light was irradiated onto the coating layer using a high-pressure mercury lamp with an integrated light dose of 200 mJ / cm. 2 A hard coat layer (HC) A was formed as a functional layer by irradiating the light with light at a wavelength of 1000 nm. The thickness of the hard coat layer A was 5 μm. Next, coating agent B was applied onto hard coat layer A to form a coating layer, and the coating layer was heated together with a transparent polyimide film at 85°C for 1 minute. Next, ultraviolet light was irradiated onto the coating layer using a high-pressure mercury lamp at an integrated light dose of 250 mJ / cm. 2 to form a hard coat layer (HC) B. The thickness of the hard coat layer B was 5 μm. In this way, a laminate including a transparent polyimide film (substrate) and hard coat layers A and B was produced.

[0033] [Example 2] <Preparation of laminate> A coating film was formed by applying hard coat coating agent A to one side of a polyethylene terephthalate (PET) film (manufactured by Toray Industries, Inc., product name 50U48, thickness 50 μm) as a substrate. Next, this coating film was dried by heating and then cured by ultraviolet irradiation. The heating temperature was 90°C and the heating time was 60 seconds. For ultraviolet irradiation, a high-pressure mercury lamp was used as the light source, and ultraviolet rays with a wavelength of 365 nm were used, with an integrated irradiation dose of 300 mJ / cm. 2 As a result, a hard coat layer (HC) having a thickness of 5 μm was formed on the PET film. Next, the surface of the HC layer of the PET film with the HC layer was plasma-treated using a roll-to-roll plasma treatment device under a vacuum atmosphere of 1.0 Pa. In this plasma treatment, argon gas was used as the inert gas, and the discharge power was set to 780 W. Next, an anti-reflection layer was formed on the HC layer of the plasma-treated PET film with the HC layer. Specifically, a 2.0 nm thick indium tin oxide (ITO) layer as an adhesion layer and a 165 nm thick SiO2 layer as an inorganic oxide underlayer were sequentially formed on the HC layer of the PET film with the HC layer using a roll-to-roll sputtering system. For the adhesion layer, an ITO target was used, and the ITO layer was deposited by MFAC sputtering using argon gas as an inert gas and 100 parts by volume of argon gas and 10 parts by volume of oxygen gas as a reactive gas. The discharge voltage was 350 V and the pressure in the deposition chamber (deposition pressure) was 0.4 Pa. For the inorganic oxide underlayer, a Si target was used, and the SiO2 layer was deposited by MFAC sputtering using 100 parts by volume of argon gas and 30 parts by volume of oxygen gas. The discharge voltage was 350 V and the deposition pressure was 0.3 Pa. Next, an anti-fingerprint layer was formed on the anti-reflection layer. Specifically, a 6 nm thick anti-fingerprint layer was formed on the inorganic oxide underlayer by vacuum deposition using a perfluoropolyether group-containing alkoxysilane compound as the deposition source. The deposition source was a solid obtained by drying "KY1903-1" (perfluoropolyether group-containing alkoxysilane compound, solid content concentration 20% by mass) manufactured by Shin-Etsu Chemical Co., Ltd. The heating temperature of the deposition source in the vacuum deposition method was 260°C. In this way, a laminate including a PET film (substrate), a hard coat layer, an anti-reflection layer (adhesion layer and inorganic oxide underlayer), and an anti-fingerprint layer was produced.

[0034] [Comparative Example 1] <Preparation of Coating Agent C for Hard Coating> A resin solution (DIC Corporation, product name: Unidic 17-806, solids concentration: 80% by mass) containing a mixture of UV-curable resin monomers and oligomers, primarily composed of urethane acrylate, dissolved in butyl acetate was added with 5 parts by mass of a photopolymerization initiator (BASF Corporation, product name: IRGACURE 906) and 0.01 parts by mass of a leveling agent (DIC Corporation, product name: GRANDIC PC4100) per 100 parts by mass of solids in the solution. Cyclopentanone and propylene glycol monomethyl ether were added to the blend in a ratio of 45:55 to achieve a solids concentration of 36% by mass. In this way, hard coat coating agent C was prepared. <Preparation of laminate> Next, the hard coat coating agent C was applied to a transparent plastic film substrate (cellulose triacetate film, manufactured by Konica Minolta Advanced Layer Co., Ltd., product name KC4UY, thickness 40 μm, refractive index 1.48) as a substrate to form a coating film so that the thickness of the hard coat layer (HC) after curing would be 7.8 μm. Next, it was dried at 90°C for 1 minute, and then irradiated with a high-pressure mercury lamp with an integrated light intensity of 300 mJ / cm. 2 The coating was cured by irradiating it with ultraviolet light. In this way, a laminate including a cellulose triacetate film (substrate) and a hard coat layer was produced.

[0035] Comparative Example 2 <Preparation of antiglare layer forming material> As a resin contained in the antiglare layer-forming material, 100 parts by weight of an ultraviolet-curable urethane acrylate resin (manufactured by DIC Corporation, product name: Unidic 17-806, solid content: 80% by weight) was prepared. Per 100 parts by weight of the resin solid content, 14 parts by weight of styrene crosslinked particles (manufactured by Soken Chemical & Engineering Co., Ltd., product name: MX-350H, weight average particle size: 3.5 μm, refractive index: 1.59) were used as antiglare layer-forming particles, 2.5 parts by weight of synthetic smectite (manufactured by Kunimine Industries Co., Ltd., product name: Sumecton SAN) which is an organic viscosity modifier was used as a thixotropy-imparting agent, 5 parts by weight of a photopolymerization initiator (manufactured by BASF, product name: OMNIRAD907), and 0.5 parts by weight of a leveling agent (manufactured by DIC Corporation, product name: Megafac F-556, solid content: 100% by weight) were mixed. This mixture was diluted with a mixed solvent of toluene and ethyl acetate (weight ratio 90 / 10) so that the solid content concentration was 30% by mass, to prepare an antiglare layer-forming material (coating liquid). <Preparation of laminate> Next, a transparent plastic film substrate (TAC film, manufactured by Fujifilm Corporation, product name TG60UL, thickness 60 μm) was prepared as the substrate. A coating film was formed on one side of the transparent plastic film substrate using a bar coater with an antiglare layer-forming material (coating liquid). Then, the transparent plastic film substrate on which this coating film was formed was transported to a drying process. In the drying process, the coating film was dried by heating at 110°C for 1 minute. Thereafter, the coating film was dried using a high-pressure mercury lamp with an integrated light intensity of 300 mJ / cm. 2 The coating was cured by irradiating it with ultraviolet light of 1000 kJ / cm to form an antiglare layer having a thickness of 5.0 μm. In this way, a laminate including a TAC film (substrate) and an antiglare layer was produced.

[0036] [Table 1]

[0037] [Table 2]

[0038] [Table 3] [Industrial Applicability]

[0039] The laminate of the present invention can be suitably used in laminate-containing optical members and image display devices (typically, liquid crystal display devices and organic EL display devices). [Explanation of symbols]

[0040] 1. Laminate 2 Base material 3 Functional Layer 3a Surface of the functional layer 4. Automatic friction and wear analysis device 41 Contactor 5 Surface force measuring device 51 Probe 51a Surface layer 6. Sliding test equipment

Claims

1. A substrate; a functional layer disposed on one side of the substrate in a thickness direction, the functional layer includes a hard coat layer, the thickness of the hard coat layer is 3 μm or more and 20 μm or less; In the following friction test by surface contact using the Bowden method, the static friction coefficient and dynamic friction coefficient of the surface of the functional layer measured using a contactor wetted with artificial sweat as specified in JIS L 0848 are both 0.13 or less, the carbon element ratio on the surface of the functional layer is 50 atomic % or less, A laminate in which the fluorine element ratio on the surface of the functional layer is 30 atomic % or more and 41.8 atomic % or less: (Friction test) placing the laminate in an automatic friction and wear analysis device; In a first step, the contactor is brought into contact with the surface of the functional layer under a load of 200 g; In a second step, the contactor is moved 50 mm at a speed of 1.7 mm / s to measure the static friction force and the dynamic friction force on the surface of the functional layer; As a third step, the contact is separated from the surface of the functional layer and returned to its initial position; The first, second and third steps are repeated five times in sequence to calculate the static friction coefficient of the surface of the functional layer from the static friction force of the surface of the functional layer, and the dynamic friction coefficient of the surface of the functional layer from the dynamic friction force of the surface of the functional layer.

2. The laminate according to claim 1, wherein the absolute value of the surface force of the laminate measured by the following surface force test is 110 μN or less: (Surface Force Test) placing the laminate in a surface force measuring device equipped with a probe having a surface layer formed from polydimethylsiloxane; placing the probe at an initial position and contacting the surface of the functional layer with the surface layer; Next, the probe is moved in a direction away from the laminate, and the absolute value of the surface force of the laminate is calculated from the minimum value of the load applied to the probe when the surface layer separates from the surface of the functional layer.

3. In the C1s spectrum measured by X-ray photoelectron spectroscopy of the surface of the functional layer, the sum of the areas of the peaks located in the range of 293 eV to 295 eV is 30 area % or more of the sum of the areas of the peaks located in the range of 280 eV to 300 eV, 3. The laminate according to claim 1, wherein the area of ​​the peak located in the range of 293 eV to 294 eV is 1.5 or more and 2.5 or less relative to the area of ​​the peak located in the range of 294 eV to 295 eV.

4. The laminate according to any one of claims 1 to 3, wherein an absolute value of a difference in the static friction coefficient before and after the sliding property test described below and an absolute value of a difference in the dynamic friction coefficient before and after the sliding property test described below are both 0.02 or less. (Sliding property test) Setting the laminate in a sliding property test device; Wetting the surface of the functional layer with the artificial sweat, and bringing a contact made of a rubber material into contact with the surface of the functional layer with a load of 2 kg; Next, the contactor is reciprocated 1000 times over a range of 50 mm at a speed of 66.7 mm / s.

5. The laminate according to claim 4 , wherein the dynamic friction coefficient before the sliding property test is greater than the dynamic friction coefficient after the sliding property test.

6. the functional layer includes an anti-fingerprint layer located on the outermost surface of the functional layer, The laminate according to claim 1 , wherein the anti-fingerprint layer is made of a vapor-deposited film of a fluorine-containing silane compound.

7. The laminate according to any one of claims 1 to 6, an optical member disposed on the opposite side of the substrate from the functional layer,

8. An image display device comprising the laminate according to any one of claims 1 to 6 as a front panel.

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