Laminate, manufacturing method thereof, and display device

Abstract

To provide a method for evaluating fingerprint resistance, which is applicable to an on-vehicle display device, a laminate excellent in the fingerprint resistance satisfying an evaluation standard by the evaluation method, a manufacturing method thereof, and a display device having the laminate.SOLUTION: Disclosed is a method for evaluating fingerprint resistance of the surface of an object, in which a measurement value difference Δ L*(θ) between a portion on the surface of the object to which artificial fingerprint liquid has been transferred and a portion to which it has not been transferred, which is determined by an equation (1) defined in the specification using a variable angle colorimeter, is used. Provided are a laminate which has the surface on which the Δ L* (θ) is 0 or less, a manufacturing method thereof, and a display device having the laminate.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a method for evaluating fingerprint resistance, a laminate, a method for manufacturing the same, and a display device. [Background technology]

[0002] In recent years, there has been an increasing need to operate various electronic devices by physically touching display devices such as touch panel displays with one's fingers. To prevent a decrease in display image performance due to fingerprints, such display devices require fingerprint resistance.

[0003] Furthermore, the surface of in-vehicle display devices is usually treated with various processes such as anti-glare, anti-reflection, and anti-fingerprint coatings to suppress the effects of reflections from sunlight, etc. However, these processes can sometimes make fingerprints more noticeable and reduce fingerprint resistance.

[0004] As a method for evaluating fingerprint resistance, Patent Document 1 describes the process of applying a diluted oleic acid solution to the surface of the object to be evaluated and then comparing the results with CIE1976L * a * b * Lightness L measured by a simultaneous photometric spectrophotometer specified by the display system * The technology that uses this as an indicator is disclosed. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-34416 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] When a display device is used inside a vehicle, such as in an in-vehicle display device, the evaluation results obtained by the evaluation method described in Patent Document 1 may differ from the results of sensory evaluation by humans inside the vehicle, and the evaluation method itself may not be able to reproduce the actual in-vehicle environment.

[0007] Therefore, the object of the present invention is to provide a method for evaluating fingerprint resistance applicable to in-vehicle display devices, a laminate with excellent fingerprint resistance that satisfies the evaluation criteria of the evaluation method, a method for manufacturing the same, and a display device having the laminate. [Means for solving the problem]

[0008] The present invention provides a method for evaluating fingerprint resistance, a laminate, a method for manufacturing the same, and a display device having the following configurations [1] to

[15] . [1] A method for evaluating the fingerprint resistance of an object surface, wherein the difference in measured values ​​ΔL is determined by the following formula (1) using a variable angle colorimeter between the portion of the object surface to which artificial fingerprint solution has been transferred and the portion to which it has not been transferred. * A method for evaluating fingerprint resistance, characterized by using (θ): Formula (1) ΔL * (θ) = L of the artificial fingerprint transfer area * -L of the non-transferable area of ​​the artificial fingerprint solution * However, the angle of incidence of light shall be -30° with respect to the normal to the surface of the object, and the measurement angle shall be +30° with respect to the normal to the surface of the object. [2] The evaluation method according to [1], wherein the method for transferring the artificial fingerprint solution involves applying the artificial fingerprint solution to a transfer substrate by a spin coating method to produce a transfer foil having a haze value of 7±2%, pressing a simulated finger against the transfer foil with a load of 60N, and then pressing the simulated finger against the surface of the object with a load of 60N for 2 seconds. [3] The evaluation method according to [1] or [2], wherein the amount of squalene adhering to the surface of the object is further used when evaluating the fingerprint resistance of the surface of the object. [4] The difference in measured values ​​ΔL obtained by the following formula (1) using a variable angle colorimeter between the area where the artificial fingerprint solution has been transferred and the area where it has not been transferred.* A laminate characterized by having a surface where (θ) is 0 or less: Formula (1) ΔL * (θ) = L of the artificial fingerprint liquid transfer part * - L of the non-transfer part of the artificial fingerprint liquid * However, the light incident angle is -30° with respect to the normal of the surface of the measurement object, and the measurement angle is +30° with respect to the normal of the surface of the measurement object. [5] Having a substrate, a predetermined layer disposed on the substrate, and a outermost layer disposed on the predetermined layer, The predetermined layer includes a first predetermined layer on the substrate side and a second predetermined layer on the outermost layer side, The laminate according to [4], wherein the refractive index of the first predetermined layer is 2.00 or less. [6] Having a substrate, a predetermined layer disposed on the substrate, and a outermost layer disposed on the predetermined layer, The predetermined layer includes a first predetermined layer on the substrate side and a second predetermined layer on the outermost layer side, The laminate according to [4] or [5], wherein the refractive index of the second predetermined layer is 1.43 or more and 1.49 or less. [7] On the surface of the laminate, ΔL at the light incident angle of -70° * The laminate according to any one of [4] to [6], wherein the angular dependence of (θ) has a negative peak in the specular reflection region and a positive peak at angles other than the specular reflection region. [8] The method for transferring the artificial fingerprint liquid is to attach the artificial fingerprint liquid to a transfer substrate by spin coating to produce a transfer foil having a haze value of 7 ± 2%, and after pressing a pseudo finger against the transfer foil with a load of 60 N, press the pseudo finger against the surface of the laminate with a load of 60 N for 2 seconds. The laminate according to any one of [4] to [7]. [9] A display device characterized by having the laminate according to any one of [4] to [8].

[10] On the surface of the laminate, the measurement value difference ΔL obtained from the following formula (1) by a variable-angle colorimeter between the part where the artificial fingerprint liquid is transferred and the part where it is not transferred *A method for manufacturing a laminate, characterized by manufacturing the laminate such that (θ) is 0 or less: Formula (1) ΔL * (θ) = L of the artificial fingerprint transfer area * -L of the non-transferable area of ​​the artificial fingerprint solution * However, the angle of incidence of light shall be -30° with respect to the normal to the surface of the object being measured, and the measurement angle shall be +30° with respect to the normal to the surface of the object being measured.

[11] A method for evaluating the fingerprint resistance of an object surface, comprising the difference in measured values ​​ΔL obtained by the following formulas (1) and (2) using a variable-angle colorimeter between the portion of the object surface to which an artificial fingerprint solution has been transferred and the portion to which it has not been transferred. * (θ) and ΔC * A method for evaluating fingerprint resistance, characterized by using (θ): Formula (1) ΔL * (θ) = L of the artificial fingerprint transfer area * -L of the non-transferable area of ​​the artificial fingerprint solution * Formula (2) ΔC * (θ) = {(a of the artificial fingerprint transfer area) * - a of the non-transferable part of the artificial fingerprint solution * )^2 + (b of the artificial fingerprint transfer area * -b of the non-transferable area of ​​the artificial fingerprint solution * )^2}^(1 / 2) However, the angle of incidence of light shall be -30° with respect to the normal to the surface of the object, and the measurement angle shall be +30° ± 15° with respect to the normal to the surface of the object.

[12] The difference in measured values ​​ΔL obtained by a variable-angle colorimeter from the area where the artificial fingerprint solution has been transferred and the area where it has not been transferred, using the following formulas (1) and (2). * (θ) and ΔC * A laminate characterized in that (θ) has a surface that satisfies the following formula (3): Formula (1) ΔL * (θ) = L of the artificial fingerprint transfer area * -L of the non-transferable area of ​​the artificial fingerprint solution * Formula (2) ΔC * (θ) = {(a of the artificial fingerprint transfer area) * - a of the non-transferable part of the artificial fingerprint solution * )^2 + (b of the artificial fingerprint transfer area * -b of the non-transferable area of ​​the artificial fingerprint solution * )^2}^(1 / 2) However, the angle of incidence of light shall be -30° relative to the normal to the surface of the object being measured, and the measurement angle shall be +30° ± 15° relative to the normal to the surface of the object being measured. Formula (3) -25≦ΔL * (θ)≦15 and ΔC * (θ)≦15

[13] Said ΔL * (θ) and the ΔC * The laminate described in

[12] , wherein (θ) satisfies the following equation (4). Formula (4) -5≦ΔL * (θ)≦5 and ΔC * (θ)≦5 A display device characterized by having the laminate described in

[14] ,

[12] , or

[13] .

[15] On the surface of the laminate, the difference in measured values ​​ΔL can be determined from the following equations (1) and (2) using a variable angle colorimeter between the areas on which the artificial fingerprint solution has been transferred and the areas on which it has not been transferred. * (θ) and ΔC * A method for manufacturing a laminate, characterized in that the laminate is manufactured such that (θ) satisfies the following equation (3): Formula (1) ΔL * (θ) = L of the artificial fingerprint transfer area * -L of the non-transferable area of ​​the artificial fingerprint solution * Formula (2) ΔC * (θ) = {(a of the artificial fingerprint transfer area) * - a of the non-transferable part of the artificial fingerprint solution * )^2 + (b of the artificial fingerprint transfer area * -b of the non-transferable area of ​​the artificial fingerprint solution * )^2}^(1 / 2) However, the angle of incidence of light shall be -30° relative to the normal to the surface of the object being measured, and the measurement angle shall be +30° ± 15° relative to the normal to the surface of the object being measured. Formula (3) -25≦ΔL * (θ)≦15 and ΔC * (θ)≦15 [Effects of the Invention]

[0009] The present invention provides a method for evaluating fingerprint resistance applicable to in-vehicle display devices, a laminate with excellent fingerprint resistance that satisfies the evaluation criteria of the evaluation method, a method for manufacturing the same, and a display device having the laminate. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic plan view showing how reflected light from sunlight shining directly onto an object inside the vehicle from the outside of the vehicle illuminates the display device. [Figure 2] This graph shows an example of the correlation between the ΔL*(θ) value and the user's sensory evaluation results. [Figure 3] This graph shows an example of the correlation between the ΔL*(SCI) value and the results of sensory evaluations by users. [Figure 4] This graph shows an example of the angular dependence of ΔL*(θ) at a light incidence angle of -70° in the laminate according to this embodiment. [Figure 5] This is an example graph showing the relationship between the ΔL*(θ) value and ΔC*(θ). [Figure 6] This figure shows images of the measurement samples according to Example 40, Example 42, and Example 47. [Modes for carrying out the invention]

[0011] In the evaluation method described in Patent Document 1, the CIE1976L of the surface of the object to be evaluated is measured before and after application of the diluted oleic acid solution. * a * b * Brightness L as defined by the display system *The fingerprint resistance of the object being evaluated is assessed using this as an indicator. In addition, Patent Document 1 describes the brightness L * A simultaneous photometric spectrophotometer is used for the measurement, and furthermore, sensory evaluation under three-wavelength fluorescent lighting is used to evaluate the accuracy of the evaluation method. However, under these conditions, the angle of incidence and the measurement angle are not defined, so it is not possible to evaluate the fingerprint resistance of the display device in the in-vehicle environment, and there were discrepancies between the evaluation results obtained by the method in Patent Document 1 and the sensory evaluation results in the actual vehicle. Furthermore, the evaluation method described in Patent Document 1 uses a diluted oleic acid solution obtained by dissolving oleic acid in ethanol to evaluate fingerprint resistance, but the adhesion state of this diluted solution to the display device sometimes differed from that of actual fingerprints. In particular, for display devices equipped with an oil-repellent coating, it was sometimes difficult to accurately evaluate fingerprint resistance due to the effect of droplet repellency of the diluted oleic acid solution. Furthermore, in the evaluation method described in Patent Document 1, a diluted oleic acid solution is applied using a finger cot to evaluate fingerprint resistance. However, in this method, it was sometimes not possible to apply a simulated fingerprint with good reproducibility.

[0012] On the other hand, the fingerprint resistance evaluation method of the present invention is similar to the method described in Patent Document 1, and CIE1976L * a * b * Brightness L as defined by the display system * Although a simultaneous photometric spectrophotometer is used as the measuring device, a variable-angle colorimeter that applies a specific light incidence angle and measurement angle is used. Thus, in this invention, assuming an in-car environment, and considering the position of the sun, the position of the display device, and the viewpoint of the user such as the driver, the measurement conditions of the variable-angle colorimeter are set to incidence angle: -30°, measurement angle: +30° (±15°), and the variable-angle brightness L before and after application of artificial fingerprint solution is measured. * The amount of change in (θ), or the angle of change in brightness L. * (θ) Change and variable saturation C *The change in (θ) is used as an indicator of fingerprint resistance. Therefore, the present invention can provide a highly accurate method for evaluating fingerprint resistance (fingerprint visibility) that can obtain evaluation results equivalent to those obtained from sensory evaluations conducted inside actual vehicles. Furthermore, in this invention, instead of a diluted oleic acid solution, for example, a conventionally known artificial fingerprint solution can be used for evaluation. Some artificial fingerprint solutions take into account solid components such as dirt and sebum, and by using such an artificial fingerprint solution, it is possible to perform evaluations that take into account actual fingerprint adhesion more accurately than with a diluted oleic acid solution. In addition, by using such an artificial fingerprint solution containing solid components, the fingerprint resistance evaluation method of the present invention can be easily applied to display devices equipped with an oil-repellent coating. Furthermore, in this invention, since fingerprint resistance can be evaluated with an artificial fingerprint solution applied using a specific transfer method, evaluation can be performed under conditions that more closely reflect the actual vehicle environment.

[0013] The present invention will be described in detail below. However, the present invention is not limited to the following embodiments. Also, in order to clarify the explanation, the following description and drawings have been simplified as appropriate. In the following description, the "~" indicating a numerical range means that the numbers written before and after it are included as the lower and upper limits. Furthermore, (meth)acrylic acid means either methacrylic acid or acrylic acid, or both.

[0014] <Method for evaluating fingerprint resistance> [First Embodiment] A fingerprint resistance evaluation method according to the first embodiment of the present invention (hereinafter sometimes referred to as this evaluation method I) is a method for evaluating the fingerprint resistance of the surface of an object (object to be measured), and the difference in measured values ​​ΔL obtained from the following formula (1) using a variable angle colorimeter between the area on the surface of the object to which artificial fingerprint solution has been transferred and the area to which it has not been transferred. * This method uses (θ). Formula (1) ΔL * (θ) = L of the artificial fingerprint transfer area * -L of the non-transferable area of ​​the artificial fingerprint solution * However, the angle of incidence of light shall be -30° with respect to the normal to the surface of the object, and the measurement angle shall be +30° with respect to the normal to the surface of the object.

[0015] As shown in Figure 1, Evaluation Method I evaluates the visibility of fingerprints (fingerprint resistance) when a user visually inspects a display device 3 in a vehicle environment, when reflected light from a light source 1, such as the sun, is shone from outside the vehicle onto an object 2 (such as interior furnishings or passengers) inside the vehicle, and the reflected light is shone onto the surface of the display device 3. In Evaluation Method I, as shown in Figure 1, in particular, the fingerprint resistance is evaluated when light from a light source 1, such as the sun, is shone onto an object 2 inside the vehicle, reflected, and shone onto the display device 3 at an angle of -30° to the normal N of the display device surface, and the user visually inspects it at an angle of +30° to the normal N. This provides evaluation results that better reflect the fingerprint resistance of the display device in a vehicle environment. Although the number of light reflections is not particularly limited, it is considered that the visibility of fingerprints in such situations is greatly influenced by the light near the specular reflection position, which is 45° or less to the normal N of the display device surface, after being reflected once from the light source 1 onto an object 2 inside the vehicle and then shone onto the display device 3. Normally, when viewed from the driver's seat, the specular reflection position with the display device in between is near the ceiling inside the vehicle, from the passenger seat.

[0016] In this evaluation method I, from the viewpoint of obtaining excellent fingerprint resistance, the above ΔL * It is preferable that (θ) is 0 or less. * A value of (θ) of 0 means that the measured values ​​obtained by the variable angle colorimeter for the areas on the object surface where the artificial fingerprint solution has been transferred and the areas where it has not are the same (there is no difference). Therefore, ΔL * (θ) is less than or equal to 0, and the closer it is to 0, the better. ΔL * The detailed method for measuring (θ) will be described later.

[0017] [Second Embodiment] A second embodiment of the present invention provides a method for evaluating fingerprint resistance (hereinafter sometimes referred to as "Evaluation Method II"), which is a method for evaluating the fingerprint resistance of the surface of an object (object to be measured), and involves measuring the difference in measured values ​​ΔL, which can be determined using a variable-angle colorimeter from the following formulas (1) and (2), between the area on the surface of the object to which artificial fingerprint solution has been transferred and the area to which it has not been transferred. * (θ) and ΔC * This method uses (θ). Formula (1) ΔL * (θ) = L of the artificial fingerprint transfer area * -L of the non-transferable area of ​​the artificial fingerprint solution * Formula (2) ΔC * (θ) = {(a of the artificial fingerprint transfer area) * - a of the non-transferable part of the artificial fingerprint solution * )^2 + (b of the artificial fingerprint transfer area * -b of the non-transferable area of ​​the artificial fingerprint solution * )^2}^(1 / 2) However, the angle of incidence of light shall be -30° relative to the normal to the surface of the object, and the measurement angle shall be +30°±15° relative to the normal to the surface of the object. Note that the measurement angle shall be within the range of +30°±15°. * ΔL at the angle where the change in (θ) is maximum * (θ) and ΔC * The evaluation is performed using (θ). Note that ΔL * The angle at which the change in (θ) is maximized is usually specular reflection (+30°), but since a deviation of a few degrees is possible, a specification such as +30° ± 15° is used.

[0018] Similar to Evaluation Method I, Evaluation Method II is used to evaluate the visibility of fingerprints (fingerprint resistance) when a user views the display device in a vehicle environment, as shown in Fig. 1, when the reflected light from an object 2 (such as interior items or passengers) inside the vehicle is irradiated onto the surface of the display device 3 after being irradiated by light from a light source 1 such as the sun from outside the vehicle. In Evaluation Method II, as shown in Fig. 1, in particular, after the light from a light source 1 such as the sun is irradiated onto an object 2 inside the vehicle, it is reflected and irradiated onto the display device at an angle of -30° with respect to the normal line N of the surface of the display device 3, and the fingerprint resistance when the user views it at an angle of +30° ± 15° (the angle at which the change amount of ΔL * (θ) is maximized) with respect to the normal line N is evaluated, and an evaluation result that better reflects the fingerprint resistance of the display device in a vehicle environment can be obtained. Although the number of light reflections is not particularly limited, for the fingerprint visibility in such a situation, it is considered that the light near the specular reflection position where the angle with respect to the normal line N of the surface of the display device 3 is 45° or less after being reflected once from the light source 1 to the object 2 inside the vehicle and then irradiated onto the display device 3 has a great influence. Usually, when viewed from the driver's seat, the specular reflection position sandwiching the display device is near the ceiling inside the vehicle on the passenger side.

[0019] In Evaluation Method II, from the perspective of obtaining excellent fingerprint resistance, the brightness change ΔL * (θ) is -25 or more and 15 or less, and the chroma change ΔC * (θ) is 15 or less, that is, it is preferably to satisfy the following formula (3). Formula (3) -25 ≤ ΔL * (θ) ≤ 15 and ΔC * (θ) ≤ 15 Also, from the same perspective, it is more preferable that the brightness change ΔL * (θ) is -20 or more and 10 or less, and the chroma change ΔC * (θ) is 10 or less, and it is even more preferable that the brightness change ΔL * (θ) is -5 or more and 5 or less, and the chroma change ΔC * (θ) is 5 or less, that is, it is preferably to satisfy the following formula (4). Formula (4) -5 ≤ ΔL *(θ)≦5 and ΔC * (θ)≦5 Note that ΔL * (θ) being 0 means that the lightness L measured by a variable angle colorimeter between the areas on the surface of the object where the artificial fingerprint solution has been transferred and the areas where it has not been transferred is * This means that they are the same (there is no difference). Similarly, ΔC * (θ) 0 means that the saturation (chromaticity a) measured by a variable angle colorimeter between the areas on the surface of the object to which the artificial fingerprint solution has been transferred and the areas to which it has not been transferred. * and b * This means that they are the same (there is no difference). Therefore, ΔL * (θ) and ΔC * The closer (θ) is to 0, the better. Note that the brightness ΔL * (θ) is the boundary between 0 and 0, at which point the appearance of the fingerprint changes to either white (whitening) or black (blackening). Also, saturation ΔC * (θ) is such that the appearance of fingerprints changes when the boundary is 30. * and b * It changes to the corresponding color. ΔL * (θ) and ΔC * The detailed method for measuring (θ) will be described later.

[0020] The artificial fingerprint solutions used in evaluation methods I and II can be any conventionally known solutions, but as mentioned above, solutions that take into account solid components such as dirt and sebum are more preferable. Fingerprints are mainly composed of water and sebum components, and the proportion of sebum components increases as water evaporates. Therefore, in most cases, it is acceptable to consider fingerprints as equivalent to sebum. Examples of components that make up sebum include fatty acids, glycerolipids, fatty acid esters, wax esters, cholesterol derivatives, and squalene. Examples of the aforementioned fatty acids include oleic acid, stearic acid, linolenic acid, palmitic acid, nonanoic acid, adipic acid, tridecanoic acid, myristoleic acid, tetradecanoic acid, and palmitoleic acid. Examples of glycerolipids include monoolein, trimiristin, monocaprylin, triolein, monolaurin, monopalmitin, monostearin, tristearin, tripalmitin, and tricaproin. Examples of the aforementioned fatty acid esters include butyl n-octanoate, benzyl octanoate, isobutyl decanoate, ethyl undecanoate, ethyl stearate, ethyl palmitate, ethyl pentadecanoate, benzyl laurate, amyl n-octanoate, and butyl myristate. Examples of the aforementioned wax esters include dodecyl stearate, decyl decanoate, hexadecyl palmitate, 3-isoamyl-6-methyl-2-heptyl myristate, myricyl palmitate, cecil palmitate, and myricyl cerotate. Examples of the cholesterol derivatives include cholesterol, 7-dehydrocholesterol, vitamin D, cholic acid, chenodeoxycholic acid, deoxycholic acid, lithocholic acid, progesterone, aldosterone, and cortisol. Furthermore, the artificial fingerprint solution may contain one or more particulate materials selected from inorganic fine particles such as silica fine particles, alumina fine particles, and iron oxide fine particles, as well as organic fine particles such as keratin fine particles, chitin fine particles, chitosan fine particles, acrylic fine particles, styrene fine particles, divinylbenzene fine particles, polyamide fine particles, polyimide fine particles, polyurethane fine particles, and melamine fine particles. The artificial fingerprint solution may also contain Kanto loam (JIS test powder 1) as a particulate material. The average particle size of the particulate material can be set as appropriate and is not particularly limited, but for example, the average particle size can be 0.05 μm or more and 100 μm or less. In addition, the artificial fingerprint solution may also contain thickeners such as carrageenan and gum arabic, and surfactants such as quaternary ammonium salts and alkylbenzene sulfonates. The blending ratio of each component constituting the artificial fingerprint solution can be set as appropriate within the range in which the effects of the present invention are obtained, and is not particularly limited. The artificial fingerprint solution used in evaluation methods I and II can be diluted with an organic solvent as appropriate when preparing the thin film (transfer film). Any conventionally known organic solvent can be used, such as isopropyl alcohol, methyl ethyl ketone, methoxypropanol, or ethanol.

[0021] For example, the following formulations can be used as artificial fingerprint solutions. - An artificial fingerprint solution obtained by adding 1.0 g of triolein to 10 g of methoxypropanol as a diluent, and then adding 400 mg of Kanto loam (Type 11 test powder as defined in JIS Z8901) and stirring. - An artificial fingerprint solution obtained by adding 200 mg of triolein to 5 g of methoxypropanol as a diluent, then adding 200 mg of keratin (derived from human epithelium, manufactured by Wako Pure Chemical Industries, Ltd.), stirring vigorously, letting it stand for 10 seconds, and then gently collecting the supernatant portion that does not contain large-particle keratin.

[0022] Here, it is preferable to use an artificial fingerprint solution that can reproduce the fingerprint components described above. Specifically, in this invention, it is preferable to use an artificial fingerprint solution that is solid at 20°C and dispersed at 40°C. For example, by adding a substance (for example, one of the components that make up sebum described above) with a melting point higher than room temperature to the artificial fingerprint solution described above, an artificial fingerprint solution that is solid at 20°C and dispersed at 40°C can be produced. An artificial fingerprint solution having these properties adheres more easily to the coating surface than conventional oleic acid dilutions using oleic acid alone, can be used for evaluation that takes into account actual fingerprint adhesion, and has excellent adhesion and evaluation reproducibility.

[0023] Furthermore, when evaluating the amount of squalene adhering to the surface, it is preferable that the squalene content in the artificial fingerprint solution be 10 to 15% by mass, from the viewpoint of performing the evaluation appropriately.

[0024] It is known that the components and their ratios that make up sebum vary from person to person and with age. However, the refractive index of sebum should be between the minimum and maximum refractive indices of the components it contains. Among the above sebum components, the substance with the lowest refractive index is n-butyl octanoate, with a refractive index of 1.42. Among these sebum components, the substance with the highest refractive index is benzyl octanoate, with a refractive index of 1.49. Therefore, the refractive index of fingerprints is thought to be in the range of 1.42 to 1.49.

[0025] While conventionally known methods can be applied to the transfer method of the artificial fingerprint solution, the following method is preferable. Specifically, it is preferable to use a method in which the artificial fingerprint solution is attached to a transfer substrate by a spin coating method to create a transfer foil with a haze value of 7±2%, a simulated finger is pressed against the transfer foil with a load of 60N, and then the simulated finger is pressed against the surface of the target object with a load of 60N for 2 seconds. In this method, the artificial fingerprint solution is dropped onto a rotating transfer substrate by the spin coating method, and a uniform thin film is formed by centrifugal force, thus enabling the transfer of the artificial fingerprint solution with good reproducibility. Here, conventionally known materials can be used as the transfer substrate, but for example, a polycarbonate plate can be used. Also, conventionally known materials can be used as the simulated finger, but for example, natural rubber (rubber hardness: Shore E60, Shore E70 according to JIS K 6253 standard) can be used. Furthermore, as mentioned above, it is preferable to use an artificial fingerprint solution that is solid at 20°C and dispersed at 40°C.

[0026] Furthermore, in evaluation methods I and II, the difference in measured values ​​Δluminance, which can be obtained by the following formula (5) using a luminance meter (e.g., product name: SR-UL1R, manufactured by Topcon Techno House Co., Ltd.) between areas on the display device surface where the artificial fingerprint solution has been transferred and areas where it has not, can also be used. Formula (5) ΔBrightness = Brightness of the area where the artificial fingerprint solution was transferred - Brightness of the area where the artificial fingerprint solution was not transferred However, the angle of light incidence is set to 85° upward with respect to the normal to the surface of the measurement sample, the measurement angle is set to 25° upward and 30° to the right with respect to the normal to the surface of the measurement sample, the measurement distance is set to 650 mm, and the measurement range is set to 0.2° (solid angle). However, since measuring luminance is difficult to perform in a specified environment due to installation angle and ambient light issues, and the evaluation is not highly reproducible, it is desirable to use evaluation method I or II of the present invention using a variable-angle colorimeter, or to use evaluation by luminance in combination with evaluation method I or II of the present invention.

[0027] In evaluation methods I and II, from the viewpoint of obtaining excellent fingerprint resistance, the above Δ brightness is 0.5 [cd / m²]. 2 It is preferable that Δluminance and ΔL are less than or equal to Δluminance and ΔL. * A certain correlation can be observed between (θ) and Δluminance and ΔL. * By setting both (θ) and (θ) to good values, better fingerprint resistance can be achieved.

[0028] When evaluating the fingerprint resistance of the object surface, the amount of squalene adhering to the object surface (for example, the amount of fingerprint components adhering) (assuming fingerprints are present) can also be used. If the object surface is oil-repellent, ΔL is used regardless of the amount of squalene adhering. * (θ) becomes 0 or less, fingerprints are less noticeable, and excellent fingerprint resistance can be achieved. On the other hand, if the surface of the object is lipophilic, ΔL increases as the amount of squalene adhering increases. * The (θ) value increases, leading to optical interference and a tendency for fingerprint resistance to decrease. Detailed methods for measuring squalene adhesion will be described later.

[0029] <Laminate> The laminate of the present invention (hereinafter sometimes referred to as "this laminate") has a measurement difference ΔL in the evaluation method I described above. * (θ), or the difference in measured values ​​ΔL in this evaluation method II. * (θ) and ΔC *Because the surface has (θ) within the specific range described above, it exhibits excellent fingerprint resistance and can make fingerprints adhering to the surface less noticeable. Furthermore, it is preferable to use the spin-coating method described above for transferring the artificial fingerprint solution used in the evaluation. Furthermore, the laminate may comprise a base material, a predetermined layer disposed on the base material, and an outermost layer disposed on the predetermined layer. The predetermined layer may include a first predetermined layer on the base material side and a second predetermined layer on the outermost layer side. In addition, other layers (intermediate layers) may be present between the base material and the first predetermined layer, between the first predetermined layer and the second predetermined layer, between the outermost layer and the second predetermined layer, etc., to the extent that the effects of the present invention can be obtained. As intermediate layers, for example, a desired functional layer, adhesive layer, ultraviolet absorption layer, infrared absorption layer, anti-reflective layer, soft (impact resistant) layer, hard coat layer, conductive layer, antistatic layer, heat insulating layer, reflective layer, primer layer, etc. may be used. Note that the first predetermined layer and the second predetermined layer may each consist of multiple layers, for example, a first predetermined layer, a first predetermined layer, a second predetermined layer, and a second predetermined layer may be formed sequentially from the base material side. The outermost layer is placed in a situation where it comes into contact with human hands during use. The outermost layer may, for example, have an oil-repellent coating layer or an oil-lipid coating layer, as described later. This laminate may be used on the operating surface of a touch panel, or on the display surface of a display panel or on protective members such as cover panels that cover it. However, the applications of this laminate are not limited to these.

[0030] Here, the refractive index of the first predetermined layer is preferably greater than 1.49, more preferably 1.60 or greater, preferably 2.00 or less, and more preferably 1.80 or less, from the viewpoint of providing excellent fingerprint resistance. Furthermore, from the viewpoint of providing excellent fingerprint resistance, the refractive index of the second predetermined layer is preferably 1.43 or higher, more preferably 1.45 or higher, preferably 1.49 or lower, and more preferably 1.47 or lower. As mentioned above, the refractive index of fingerprints is considered to be between 1.42 and 1.49, so it is more preferable that the refractive index of the second predetermined layer be close to its average value of 1.46. If the refractive index of the second predetermined layer is between 1.43 and 1.49, the interfacial reflectance between the fingerprint and the laminate surface will be reduced, the difference between the fingerprint-covered area and the other areas will be reduced, and the fingerprint will become less noticeable. Here, the refractive index of the substrate can be set as appropriate, but for example, a substrate with a refractive index of 1.50 can be used. The refractive index of each layer can be measured using an ellipsometer or the like.

[0031] The material constituting the substrate is not particularly limited, and conventionally known materials can be used as appropriate. For example, the substrate may be a transparent resin film or laminated film (laminated board) made of TAC (triacetylcellulose), PMMA (polymethyl methacrylate), PC (polycarbonate), PET (polyethylene terephthalate), etc., i.e., a resin substrate. Alternatively, a conventionally known glass substrate (glass substrate) may be used as the substrate.

[0032] Furthermore, the materials constituting the first predetermined layer, the second predetermined layer, and the outermost layer are not particularly limited, but may be composed of layers made of active energy ray curable resins or thermosetting resins, or of thin films obtained by, for example, vacuum deposition, sputtering, or wet coating of metal oxides (e.g., ZrO2, Al2O3, SiO2). These layers can be given different properties depending on the additives they contain and the type of resin they contain.

[0033] Furthermore, in this laminate, ΔL at an incident light angle of -70° *It is preferable to have an oil-repellent coating on the (outermost) surface such that the angle dependence of (θ) has a negative peak in the specular reflection region and a positive peak at angles outside the specular reflection region. For example, ΔL * The angular dependence of (θ) is calculated by taking the incident light angle as -70° and the measurement angle as -60° to +85°, and then determining ΔL for each angle. * It can be measured by calculating (θ). By having a specific oil-repellent coating on the surface, ΔL can be measured regardless of the amount of fingerprint (squalene) adhering to it. * (θ) can be easily made to 0 or less, making fingerprints less noticeable. If the outermost layer is oleophobic, its refractive index can be, for example, 1.30 to 1.50. The specular reflection region at a light incidence angle of -70° is +70 ± 10°. Also, the aforementioned angle of change ΔL * The angle dependence of (θ) is not limited to the incident light angle of -70°; similar behavior is observed even at the incident light angle of -30°. Here, Figure 4 shows the ΔL at a light incidence angle of -70° in a laminate having an oil-repellent coating on its surface according to this embodiment. * A graph showing an example of the angle dependence of (θ) is shown. In the graph shown in Figure 4, ΔL at an incident light angle of -70° * The angle dependence of (θ) has a negative peak in the specular reflection region (+70±10°). Furthermore, the graph shows a positive peak at angles outside the specular reflection region. It can also be interpreted that having a negative peak in the specular reflection region means that the angle (°) at the peak of that negative peak falls within the specular reflection region (70° in Figure 4). Similarly, having a positive peak at angles outside the specular reflection region means that the angle (°) at the peak of that positive peak falls within the range outside the specular reflection region (55° in Figure 4).

[0034] In this laminate, from the viewpoint of providing excellent fingerprint resistance, the Δluminance on the surface calculated from the above formula (5) is 0.5 [cd / m²]. 2 It is preferable that it be less than or equal to the following:

[0035] Some of the numerical values ​​mentioned above are based on simulation results by the inventors. The simulations were performed under various conditions in which the refractive index (including the refractive index of air) and thickness of each component of the laminate were appropriately changed, and the desired numerical range was determined based on the results. For example, in the simulation in which the distance from the surface of the outermost layer, which is placed on the second predetermined layer, to the second predetermined layer was determined to be 60 nm or less in this laminate having a lipophilic coating, only the thickness of the lipophilic outermost layer of the laminate was changed. Also, while the thickness of a fingerprint is usually 10 to several hundred nm in actual measurements, 50 nm was used as a representative value in this simulation. The optical interference ΔY in the simulation is given by ΔY = ∫ A -R B )dλ, where R A : Intensity reflectance on the surface of the laminate, R B : This is the intensity reflectance of a fingerprint attached to the surface of a laminate. Y is the lightness L. * Since it is proportional to ΔY, if ΔL is a small value, * (θ) is also a small value in a similar manner.

[0036] In the simulation, the intensity reflectance Rm is given by the following equation I.

[0037]

number

[0038] In equation I, ηa is the refractive index of air, ηs is the refractive index of the substrate, and m is a component of the characteristic matrix [M]. The characteristic matrix [M] is expressed by equation II below.

[0039]

number

[0040] In Equation II, n is the number of layers stacked on the substrate, j is the order of each layer stacked on the substrate from the outermost layer (topmost layer), η is the optical admittance, and φ is the optical path length. If a fingerprint is present on the surface of the laminate, the fingerprint is assumed to be the outermost layer of the laminate. Furthermore, η is expressed by Equation III below, and φ is expressed by Equation IV below.

[0041]

number

[0042]

number

[0043] In equations III and IV, N is the refractive index of each layer, and φ is the angle of incidence to each layer. Also, in equation IV, d is the thickness of each layer, and λ is the wavelength of light.

[0044] In this embodiment, the distance from the surface of the laminate to the second predetermined layer, and the refractive index of each layer, can be measured non-destructively using an ellipsometer. Alternatively, the laminate may be cut, and the cut surface may be observed or analyzed after ion milling or FIB (Focused Ion Beam) processing. For example, qualitative analysis may be performed using XPS (X-ray photoelectron spectroscopy) to identify elements and structures. The number of layers and film thickness may also be confirmed using an electron microscope. By comparing the measurement results from the ellipsometer with other observation or analysis results, it is possible to confirm the structure with higher accuracy.

[0045] <Method for manufacturing laminates> In the method for manufacturing a laminate of the present invention (hereinafter sometimes referred to as "this manufacturing method"), the above-mentioned ΔL is applied to the surface of the laminate. * (θ), or ΔL * (θ) and ΔC *The laminate is fabricated such that (θ) falls within the specified range described above. The laminate obtained by this manufacturing method can have excellent fingerprint resistance. In this manufacturing method, ΔL * (θ), or ΔL * (θ) and ΔC * The surface of the laminate can also be surface-treated so that (θ) falls within the specific range described above. The surface treatment method is not particularly limited as long as it is within the range in which the effects of the present invention can be obtained, and conventionally known methods can be used. For example, an AG (Anti-Glare) coating can be applied to the surface of the substrate. The AG coating diffuses reflected light by creating very fine irregularities on the surface of the substrate, thereby suppressing reflection and glare.

[0046] The laminate of the present invention can be manufactured, for example, by the following procedure. First, a coating solution containing an active energy ray-curable resin is applied to a substrate such as a resin substrate or a glass substrate using a bar coater or the like, and dried by heating as needed (for example, 80°C for 90 seconds). Then, active energy ray curing is performed in an inert gas atmosphere (for example, nitrogen gas) to form a hard coat film of a predetermined thickness (for example, 5 μm).

[0047] Active energy ray curable resins contain polymerizable compounds that undergo a curing reaction upon irradiation with active energy rays to form a cured product. Polymerizable compounds can include monofunctional monomers, polyfunctional monomers, oligomers, and polymers having vinyl or (meth)acryloyl groups.

[0048] Examples of monofunctional monomers include methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate, isobutyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cetyl (meth)acrylate, isovonyl (meth)acrylate, cyclohexyl (meth)acrylate, tricyclodecyl (meth)acrylate, benzyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentanyl (meth)acrylate, and pentamethylpropyl (meth)acrylate. Peridyl, ethyl hexahydrophthalate (meth)acrylate, ethyl 2-hydroxypropylphthalate (meth)acrylate, 2-hydroxybutyl (meth)acrylate, butoxyethyl (meth)acrylate, phenoxyethyl (meth)acrylate, methoxydiethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, and other (meth)acrylate esters, styrene, α-methylstyrene, p-methoxystyrene, m-methoxystyrene, di-t-butyl fumarate, di-n-butyl fumarate, diethyl fumarate, mono(di)methyl itaconate, mono(di)ethyl itaconate, N-isopropylacrylamide, N-vinyl-2-pyrrolidone, etc. can be used.

[0049] Examples of polyfunctional monomers include polyfunctional polymerizable compounds containing two or more (meth)acryloyl groups, such as esters of polyhydric alcohols and (meth)acrylic acid, and urethane-modified acrylates. Examples of polyhydric alcohols include dihydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, polypropylene glycol, propanediol, butanediol, pentanediol, hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, 2,2'-thiodiethanol, and 1,4-cyclohexanedimethanol; and trihydric or higher alcohols such as trimethylolpropane, glycerol, pentaerythritol, diglycerol, dipentaerythritol, and ditrimethylolpropane.

[0050] Urethane-modified acrylates can be obtained by a urethane reaction between an organic isocyanate having multiple isocyanate groups in one molecule and a (meth)acrylic acid derivative having hydroxyl groups. Examples of organic isocyanates having multiple isocyanate groups in one molecule include hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, naphthalene diisocyanate, diphenylmethane diisocyanate, xyleline diisocyanate, and dicyclohexylmethane diisocyanate, which have two isocyanate groups in one molecule, as well as organic isocyanates having three isocyanate groups in one molecule obtained by isocyanurate modification, adduct modification, or biuret modification of these organic isocyanates.

[0051] Examples of oligomers having vinyl groups or (meth)acryloyl groups include polyester oligomers, epoxy oligomers, urethane oligomers, polyether oligomers, alkyd oligomers, polybutadiene oligomers, polythiol polyene oligomers, and spiroacetal oligomers, as well as oligomers obtained by adding vinyl groups or (meth)acryloyl groups to oligomers made from polyhydric alcohol polyfunctional (meth)acrylic acid esters. Examples of polymers having vinyl groups or (meth)acryloyl groups include polymer types of the above-mentioned oligomers having vinyl groups or (meth)acryloyl groups.

[0052] Furthermore, the coating solution may contain additives as needed, such as diluent solvents, beads, fillers, photodegradable or thermally degradable polymerization initiators, metal oxides, surfactants, UV absorbers, infrared absorbers, antioxidants, photosensitizers, light stabilizers, and silane coupling agents.

[0053] Examples of diluent solvents include toluene, xylene, ethyl acetate, propyl acetate, butyl acetate, methyl cellsolve, ethyl cellsolve, ethyl cellsolve acetate, methyl alcohol, ethyl alcohol, isopropyl alcohol, butyl alcohol, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, hexane, heptane, octane, decane, dodecane, propylene glycol monomethyl ether, and 3-methoxybutanol.

[0054] Examples of polymerization initiators include benzophenones, acetophenones, α-amyloxime esters, Michler-benzoylbenzoate, tetramethyl thurum monosulfide, and thioxanthones. Specifically, these include 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-molpherinopropan-1-one, and 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl Examples include 1-propan-1-one, benzoin, 2,2-dimethoxy-1,2-diphenylethane-1-one, benzophenone, [4-(methylphenylthio)phenyl]phenylmethanone, 4-hydroxybenzophenone, 4-phenylbenzophenone, 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, α-amyloxime ester, Michler-benzoylbenzoate, and tetramethylthurum monosulfide.

[0055] Examples of metal oxides include silica, hollow silica, aluminum oxide (alumina), titanium oxide, antimony oxide, zinc oxide, tin oxide, and zirconium oxide.

[0056] Surfactants are used for purposes such as compatibilization when various raw materials are blended, and for improving the smoothness of the coating. While not particularly limited, examples include acrylic copolymers (ionic and nonionic), methacrylic copolymers, leveling agents for solvent-based paints, and polysiloxane compounds.

[0057] As the photosensitizer, known compounds for polymerization initiators can be used, such as tertiary amines like tributylamine, triethylamine, polyethyleneimine, poly-n-butylphosphone, ethyl p-dimethylaminobenzoate, and isoamyl p-dimethylaminobenzoate.

[0058] The proportions of these various components can be appropriately set within the range in which the effects of the present invention can be obtained, and are not particularly limited. By appropriately blending these various components, various properties such as the optical properties, coating properties, and durability of the manufactured laminate can be adjusted. Furthermore, the active energy rays and their irradiation dose can also be those of conventionally known conditions, for example, a metal halide lamp can be used.

[0059] Next, the obtained hard coat film is subjected to plasma treatment, and an AR (Anti-Reflection) coating film, which will be the first predetermined layer (high refractive index layer) and the second predetermined layer (low refractive index layer), is formed by vacuum deposition. Here, the constituent materials of each layer can be appropriately selected according to the desired refractive index and reflectance, and the number of layers and thickness can also be set as appropriate. For example, the first predetermined layer and the second predetermined layer may be formed as single layers each, or they may be laminates in which multiple layers are stacked alternately. Furthermore, the thickness of the first predetermined layer and the second predetermined layer can be, for example, 1 nm to 200 nm each. Furthermore, each layer may be formed using methods such as sputtering or wet coating.

[0060] The first predetermined layer can be made of materials such as niobium pentoxide (Nb2O5), titanium dioxide (TiO2), tungsten oxide (WO3), cerium oxide (CeO2), tantalum pentoxide (Ta2O5), zinc oxide (ZnO), indium oxide (In2O3), tin oxide (SnO2), hafnium oxide (HfO2), indium tin oxide (ITO), zirconium oxide (ZrO2), aluminum oxide (Al2O3), antimony oxide (Sb2O3), neodymium oxide (Nd2O3), or zinc sulfide (ZnS). Furthermore, if conductive properties are to be imparted to the first predetermined layer, for example, ITO or indium zinc oxide (IZO) can be used. Furthermore, the first predetermined layer may also be made of thermosetting resins such as phenolic resin, urea resin, diallyl phthalate resin, melamine resin, guanamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, amino alkyd resin, melamine-urea cocondensation resin, silicon resin, or polysiloxane resin. In this case, the first predetermined layer may also contain inorganic materials such as silica, alumina, zirconia, or titania, or organic materials such as acrylic resin.

[0061] The second predetermined layer preferably contains an oxide of Si, and is preferably a layer mainly composed of SiO2 (an oxide of Si). Here, the main component refers to the component that is present in the largest quantity among the components contained in the target (in this case, the second predetermined layer). In addition to SiO2, the second predetermined layer may contain elements such as Na for the purpose of improving durability, Zr, Al, and N for the purpose of improving hardness, and Zr and Al for the purpose of improving alkali resistance. The second predetermined layer may contain, for example, magnesium fluoride (MgF2), sodium fluoride (NaF), cryolite (Na3AlF6), thiolite (Na5Al3F 14 It can also contain lithium fluoride (LiF), aluminum fluoride (AlF3), calcium fluoride (CaF2), styrene fluoride (SrF2), zirconium fluoride (ZrF4), barium fluoride (BaF2), yttrium fluoride (YF3), etc.

[0062] More specifically, for example, as a first predetermined layer, an AR coating film with a refractive index of 1.70 (e.g., film thickness: 150 nm) can be formed by vacuum deposition using raw materials: ZrO2 / Al2O3. Furthermore, for example, as a second predetermined layer, an AR coating film with a refractive index of 1.46 (e.g., film thickness: 90 nm) can be formed on the first predetermined layer by vacuum deposition using raw materials: SiO2.

[0063] Next, a silane coupling agent (e.g., a perfluoropolyether-based silane coupling agent) is applied to the second predetermined layer by spraying, and cured for a predetermined time (e.g., 12 hours) in a high-temperature, high-humidity environment (e.g., 50°C, 90% relative humidity) to form an AF (Anti-Fingerprint) coating film of a predetermined thickness (e.g., 10 nm) as the outermost layer. Based on the above, a laminate according to the first embodiment of the present invention can be obtained.

[0064] For example, as shown in Example 40 described later, an AR coating film with a refractive index of 2.33 (e.g., film thickness: 24 nm) can be formed as a first predetermined layer by sputtering using the raw material: niobium pentoxide. Furthermore, for example, an AR coating film with a refractive index of 1.46 (e.g., film thickness: 33 nm) can be formed as a second predetermined layer by sputtering using the raw material: silicon dioxide. Furthermore, a first predetermined layer with the same composition but different thicknesses (e.g., film thickness: 42 nm) and a second predetermined layer (e.g., film thickness: 85 nm) can be further formed on the second predetermined layer. Then, as described above, by forming the outermost layer on this second predetermined layer, a laminate according to the second embodiment of the present invention can be obtained.

[0065] Furthermore, as the outermost layer, an oil-repellent coating layer can be used, formed using a fluorine compound having at least one functional group selected from the group consisting of fluoroalkyl groups, fluorooxyalkyl groups, fluoroalkenyl groups, fluoroalkanediyl groups, and fluorooxyalkanediyl groups. These functional groups may have some -H groups remaining, or all H groups may be replaced with fluorine (-F) groups. The structure may also be branched, and multiple branched structures may be linked together to form dimers, trimers, oligomers, or polymer structures. In addition, the fluorine compound may have reactive groups such as silyl ether groups, alkoxysilyl groups, silanol groups obtained by hydrolysis of alkoxysilyl groups, carboxyl groups, hydroxyl groups, epoxy groups, vinyl groups, allyl groups, acryloyl groups, and methacryloyl groups.

[0066] As the above-mentioned fluorine compound, for example, a compound represented by the following general formula (A) can be used. R f1 -R 2 -D 1 ...General formula (A) (R f1 R includes a moiety containing a fluoroalkyl group, a fluorooxyalkyl group, a fluoroalkenyl group, a fluoroalkanediyl group, or a fluorooxyalkanediyl group. 2 D 1 (This indicates the reactive site.)

[0067] Examples of compounds represented by general formula (A) include the following: 2,2,2-trifluoroethyl acrylate, 2,2,3,3,3-pentafluoropropyl acrylate, 2-perfluorobutyl ethyl acrylate, 3-perfluorobutyl-2-hydroxypropyl acrylate, 2-perfluorohexyl ethyl acrylate, 3-perfluorohexyl-2-hydroxypropyl acrylate, 2-perfluorooctyl ethyl acrylate, 3-perfluorooctyl-2-hydroxypropyl acrylate, 2-perfluorodecyl ethyl acrylate, 2-perfluoro-3-methylbutyl ethyl acrylate, 3- Perfluoro-3-methoxybutyl-2-hydroxypropyl acrylate, 2-perfluoro-5-methylhexylethyl acrylate, 3-perfluoro-5-methylhexyl-2-hydroxypropyl acrylate, 2-perfluoro-7-methyloctyl-2-hydroxypropyl acrylate, tetrafluoropropyl acrylate, octafluoropentyl acrylate, dodecafluoroheptyl acrylate, hexadecafluorononyl acrylate, hexafluorobutyl acrylate, 2,2,2-trifluoroethyl methacrylate, 2,2,3,3,3-Pentafluoropropyl methacrylate, 2-Perfluorobutyl ethyl methacrylate, 3-Perfluorobutyl-2-hydroxypropyl methacrylate, 2-Perfluorooctyl ethyl methacrylate, 3-Perfluorooctyl-2-hydroxypropyl methacrylate, 2-Perfluorodecyl ethyl methacrylate, 2-Perfluoro-3-methylbutyl ethyl methacrylate, 3-Perfluoro-3-methylbutyl-2-hydroxypropyl methacrylate, 2-Perfluoro-5-methylhexyl ethyl methacrylate, 3-Perfluoro-5-methylhexyl Examples include 2-hydroxypropyl methacrylate, 2-perfluoro-7-methyloctylethyl methacrylate, 3-perfluoro-7-methyloctylethyl methacrylate, tetrafluoropropyl methacrylate, octafluoropentyl methacrylate, octafluoropentyl methacrylate, dodecafluoroheptyl methacrylate, hexadecafluorononyl methacrylate, 1-trifluoromethyltrifluoroethyl methacrylate, hexafluorobutyl methacrylate, and triacryloyl-heptadecafluorononenyl-pentaerythritol. In addition to these, a conventionally known oil-repellent coating layer can be used as the outermost layer.

[0068] Furthermore, as the outermost layer, for example, a lipophilic coating layer using a hydrolyzable organosilane compound (e.g., one containing a hindered ester group) or a hydrolysis condensate thereof can be used. The organosilane compound may contain a hindered ester group that has excellent lipophilicity and heat resistance, and a hydrolyzable silyl group (e.g., an alkoxysilyl group) or a hydroxyl group-containing silyl group. Conventionally known lipophilic coating layers can be used, but for example, the organosilane compound described in Japanese Patent Application Publication No. 2020-203838 can be used.

[0069] <Display device> The display device of the present invention (hereinafter sometimes referred to as "this display device") is not particularly limited as long as it is equipped with the laminate that satisfies either the evaluation method I or II described above, or both evaluation methods I and II, and any conventionally known laminate can be applied as appropriate. Because this display device having the laminate has excellent fingerprint resistance, it can be suitably used in various electronic devices such as display devices equipped with touch panels or display panels. [Examples]

[0070] The present invention will be described in more detail below using examples, but the present invention is not limited to these examples. Examples 1 to 14 and 30 to 31 described later are examples for evaluating the fingerprint resistance evaluation method according to the first embodiment of the present invention, Examples 15 to 29 are examples for evaluating a conventional evaluation method, and Examples 40 to 50 are examples for evaluating the fingerprint resistance evaluation method according to the second embodiment of the present invention.

[0071] (ΔL * (θ) value (and ΔC) * (Confirmation of the correlation between the (θ) value and the sensory evaluation results) (1) Preparation of measurement samples First, a transfer foil of artificial fingerprint solution was prepared by dropping 2.0 g of artificial fingerprint solution onto a colorless, transparent polycarbonate plate measuring 115 mm x 90 mm and 2.0 mm thick, and then spin-coating it to achieve a HAZE value of 7 ± 2%. The HAZE value was measured using a haze meter (product name: NDH-5000, manufactured by Nippon Denshoku Industries Co., Ltd.) and calculated using the formula: HAZE value (%) = diffuse transmittance ÷ total light transmittance. The artificial fingerprint solution used was solid at 20°C and dispersed at 40°C. Next, a natural rubber pad (natural rubber, rubber hardness: Shore E70) with a diameter of 20 mm and a thickness of 2 mm was pressed onto the transfer foil of the artificial fingerprint solution with a force of 60 N for 2 seconds. Then, the natural rubber pad with the artificial fingerprint solution transferred onto it was pressed onto the sample with a force of 60 N for 2 seconds to transfer the artificial fingerprint solution to the sample, thereby preparing a sample for measurement. In this embodiment, ΔL * (θ)(and ΔC)* Since the purpose is to verify the correlation between (θ)) and the sensory evaluation results, a detailed explanation of each sample will be omitted, but for example, the following samples were used in the examples below. Example 1: A film substrate with an AG coating on the surface, on which a first layer with a refractive index of 2.33 and a second layer with a refractive index of 1.46 were formed, and the surface was coated with an oil-repellent coating (reflectance: 0.3%). Example 2 (same sample as Example 16): The glass substrate of Example 1 was changed to a resin plate (reflectance: 0.3%). Example 3 (same sample as Example 15): A resin plate with an AG coating on the surface was used as the substrate, and the surface was coated with an oil-lipophilic coating (reflectance: 4.5%). Example 4: A resin plate with an AG coating on the surface, on which a first layer with a refractive index of 2.33 and a second layer with a refractive index of 1.46 were formed (reflectance: 0.4%). Example 31: A glass substrate with a first layer with a refractive index of 1.43 was formed, and the surface was coated with an oil-lipophilic coating (reflectance: 3%). Example 40: On a film substrate coated with AG on its surface, four layers are formed in the following order from the substrate side: first layer (thickness: 24 nm), second layer (thickness: 33 nm), first layer (thickness: 42 nm), and second layer (thickness: 85 nm), with a first layer having a refractive index of 2.33 (raw material: dinibium pentoxide) and a second layer having a refractive index of 1.46 (raw material: silicon dioxide). The surface is coated with an oil-repellent coating (reflectance: 0.7%, anti-fouling layer thickness: 8 nm).

[0072] (2) Specular reflection fingerprint resistance ΔL in the first embodiment * Measurement of (θ) In the obtained measurement samples (Examples 1-14, 30-31), the areas where the artificial fingerprint solution was transferred and the areas where it was not transferred, i.e., the areas where the artificial fingerprint solution was attached and the areas where it was not attached, were measured using a variable angle colorimeter (product name: VC-2, manufactured by Suga Test Instruments Co., Ltd.) to determine the CIE1976L * a * b * Angle of change in brightness L as defined by the display system * The values ​​were measured separately. Then, according to the following equation (1), the difference between the two measured values ​​ΔL * (θ) was calculated. Formula (1) ΔL * (θ) = L of the artificial fingerprint transfer area* -L of the non-transferable area of ​​the artificial fingerprint solution * However, the angle of incidence of light was set to -30° relative to the normal to the surface of the measurement sample, and the measurement angle was set to +30° relative to the normal to the surface of the measurement sample.

[0073] (3) Specular reflection fingerprint resistance ΔL in the second embodiment * (θ) and ΔC * Measurement of (θ) In the obtained measurement samples (Examples 40-50), the areas where the artificial fingerprint solution was transferred and the areas where it was not transferred, i.e., the areas where the artificial fingerprint solution was attached and the areas where it was not attached, were measured using a variable angle colorimeter (product name: VC-2, manufactured by Suga Test Instruments Co., Ltd.) according to CIE1976L * a * b * Angle of change in brightness L as defined by the display system * and angle-shifting chromaticity a * , b * The following measurements were taken. Then, the difference between the two measurements, ΔL, was calculated according to equations (1) and (2) below. * (θ) and ΔC * (θ) was calculated. Formula (1) ΔL * (θ) = L of the artificial fingerprint transfer area * -L of the non-transferable area of ​​the artificial fingerprint solution * Formula (2) ΔC * (θ) = {(a of the artificial fingerprint transfer area) * - a of the non-transferable part of the artificial fingerprint solution * )^2 + (b of the artificial fingerprint transfer area * -b of the non-transferable area of ​​the artificial fingerprint solution * )^2}^(1 / 2) However, the angle of incidence of light was set to -30° relative to the normal to the surface of the object, and the measurement angle was set to +30°±15° relative to the normal to the surface of the object. Note that the measurement angle was within the range of +30°±15° ΔL * The angle used was the one that maximized the change in (θ).

[0074] (4) Conducting sensory evaluation For the obtained measurement samples (Examples 1-14, 30-31, 40-50), an evaluation environment was constructed that reproduced the angle of incidence of sunlight and the positional relationship between the display device and the user in an actual vehicle environment. Sensory evaluation was then performed by humans based on the following sensory evaluation criteria. Specifically, artificial sunlight lighting was used as the sunlight, with an illuminance of 30,000-60,000 lux, the reflector was white cotton, the angle of incidence of the artificial sunlight lighting was -30°, and the observation angle by the user was +30°. • Sensory evaluation criteria 5. No fingerprints are visible. 4. Fingerprints are barely visible. 3: Some fingerprints are visible. 2: Fingerprints are visible. 1: Fingerprints are clearly visible.

[0075] Following the procedure described above, ΔL was calculated for 27 measurement samples 1-14, 30, 31, and 40-50. * (θ) value and ΔC * (θ)(ΔC * (θ) was measured (only for samples 40-50) and sensory evaluation was performed by the user, and ΔL * (θ) value (and ΔC) * The correlation between the (θ) value and the sensory evaluation results was confirmed. Table 1 below shows the results for measurement samples 1-14 and 30-31 according to the first embodiment, and Figure 2 shows a graph illustrating the correlation between each measurement sample. Furthermore, Table 4 below shows the results for measurement samples 40-50 according to the second embodiment, and Figure 5 shows the ΔL for each measurement sample. * (θ) value and ΔC * A graph showing the relationship of (θ) values ​​is included, and images of each measurement sample are shown in Figure 6. Figures 6(a) to (c) correspond to samples 40, 42, and 47, respectively. [Table 1]

[0076] Regarding the first embodiment, as shown in Figure 2, ΔL * A certain correlation was found between the (θ) value and the sensory evaluation results. Furthermore, ΔL *When (θ) is 0 or less, the sensory evaluation result is 4 or higher, indicating excellent fingerprint resistance. Furthermore, ΔL * In example 30, where (θ) is less than or equal to 0 and closest to 0, the sensory evaluation result was 5, indicating the best result.

[0077] [Table 2]

[0078] Regarding the second embodiment, as shown in Figure 5 and Table 4, ΔL * (θ) value and ΔC * A certain correlation was found between the (θ) value and the sensory evaluation results. Furthermore, ΔL * (θ) is between -25 and 15 and ΔC * When (θ) is 15 or less (the area enclosed by the dotted line in Figure 5), the sensory evaluation result is 3 or higher, indicating good fingerprint resistance. Furthermore, ΔL * (θ) is greater than or equal to -20 and less than or equal to 10 and ΔC * When (θ) is 10 or less, the sensory evaluation result is 4 or higher, indicating excellent results. In the second embodiment, ΔL * (θ) value and ΔC * By using two (θ) values, the brightness and color of a fingerprint can be evaluated. For example, brightness ΔL * The (θ) value is 0, and the appearance of the fingerprint changes from white to black. Also, the saturation ΔC * The (θ) value is such that the appearance of fingerprints changes depending on the chromaticity a of 30. * , b * It changes to the corresponding color.

[0079] (Confirmation of the correlation between conventional fingerprint resistance evaluation methods and sensory evaluation results) (1) Preparation of measurement samples (Examples 15 to 29) Eight pieces of gauze were laid out, and one drop of oleic acid was placed on each piece and left for 10 seconds. Next, a piece of silicone rubber was placed on the area where the oleic acid had been dropped, a 500g load was applied, and it was left still for 2 seconds. Then, the silicone rubber was placed on eight new pieces of gauze, a 500g load was applied, and it was left still for 2 seconds. Subsequently, the silicone rubber was transferred onto the sample, a 500g load was applied, and it was left still for 2 seconds to transfer the oleic acid to the sample, thus preparing a sample for measurement.

[0080] (2)ΔL * Measurement of (SCI) In the obtained measurement samples (Examples 15 to 29), the areas where oleic acid was transferred and the areas where it was not transferred, i.e., the areas where oleic acid was attached and the areas where it was not attached, were colorimetered (product name: CM-5, manufactured by Konica Minolta) to measure CIE1976L * a * b * Brightness L as defined by the display system * The values ​​were measured separately. Then, according to the following equation (6), the difference between the two measured values ​​ΔL * (SCI) was calculated. Formula (6) ΔL * (SCI) = L of the oleic acid transfer region * -L of the non-transferred oleic acid region *

[0081] (3) Conducting sensory evaluation Using the sensory evaluation method described above, human sensory evaluation was performed on the obtained measurement samples. Following the procedure described above, ΔL was applied to 15 measurement samples 15-29. * (SCI) value measurement and user sensory evaluation are performed, ΔL * The correlation between the (SCI) value and the sensory evaluation results was examined. Table 2 below shows the results for each measurement sample, and Figure 3 shows a graph illustrating the correlation between each measurement sample. [Table 3]

[0082] As shown in Figure 3, the optical index ΔL, which represents the reflection intensity at all angles integrated by an integrating sphere, has conventionally been used as an evaluation index for fingerprint resistance. * (SCI) revealed that it is difficult to properly evaluate fingerprint resistance. Furthermore, with the conventional transfer method described above, oleic acid may remain on the gauze or droplet repulsion may occur, making it difficult to transfer oleic acid to the sample with good reproducibility.

[0083] (Measurement of squalene deposit amount) Assuming a laminate with fingerprints attached according to the first embodiment, the artificial fingerprint solution (squalene content: 13% by mass) was transferred to the surface of the measurement sample. The artificial fingerprint solution attached to the sample surface was then cleaned by rubbing it with n-hexane using quartz wool, which had been cleaned of any attached oil by solvent washing, and then rinsed with n-hexane. The washings were collected in a 40 mL container. The used quartz wool was then placed in the container, which was sealed tightly, and ultrasonically extracted for 5 minutes. 50 mL of the resulting solution was measured and placed in a measuring device to measure the amount of squalene. The calibration curve used to measure the amount of squalene was created by applying standard solutions, which were gradually diluted with n-hexane, to the measuring device and using the adjusted concentrations and the area values ​​obtained from the measurement results. • Measuring device Gas chromatography (GC): Agilent Technologies 7890B (product name) Mass spectrometer (MS): JEOL JMS-Q1500GC (product name) ·GC conditions Inlet temperature: 280℃ Introduction method: splitless method Volume introduced: 2 μL (using an autosampler) Analytical column: Agilent Technologies (product name) 5% Phenyl-95% Methylsiloxane Carrier gas: Helium Head pressure: 64.50 kPa (constant pressure) Oven conditions: 60°C (3 min) - 20°C / min - 300°C MS conditions Ionization method: EI Measurement method: Scan measurement using electron ionization method Measurement mass range: m / Z = 40~425 Ionization voltage: 70 eV Ion source temperature: 200℃ Interface temperature: 250℃

[0084] As the measurement sample mentioned above, a display device equipped with an oil-repellent coating, specifically, ΔL at a light incidence angle of -70° * We used a (θ) whose angle dependence has a negative peak in the specular reflection region (70±10°) and a positive peak at angles outside the specular reflection region. * The angular dependence of (θ) is given by the specular reflection fingerprint resistance ΔL mentioned above. * In the same method as for measuring (θ), the angle of incidence of light is set to -70°, and the measurement angle is set to -60° to +85°, and ΔL for each angle is measured. * This was determined by calculating (θ). Below are the amount of squalene attached to the measurement sample after artificial fingerprint solution transfer (assuming fingerprints were attached) and ΔL obtained from the above formula (1). * The relationship with (θ) is shown in Table 3 below. [Table 4]

[0085] As shown in Table 3 above, in a display device equipped with an oil-repellent coating, ΔL is not affected by the amount of squalene adhering to the surface after artificial fingerprint solution transfer (assuming fingerprints have been applied). * (θ) is less than or equal to 0, indicating excellent fingerprint resistance.

[0086] From the above, it can be seen that the fingerprint resistance evaluation methods according to the first and second embodiments of the present invention are superior evaluation methods that can be applied to in-vehicle display devices compared to conventional evaluation methods. It should be noted that the present invention is not limited to the above embodiments, and can be modified as appropriate without departing from the spirit of the invention. [Explanation of Symbols]

[0087] 1. Light source 2 objects 3 indicates the device N normal

Claims

1. The difference ΔL in the measurement value between the area where the artificial fingerprint liquid has been transferred and the area where it has not been transferred is calculated using a goniochromatic colorimeter according to the following formula (1): ＊ A laminate having a surface in which (θ) is 0 or less: Formula (1) ΔL ＊ (θ) = L of the artificial fingerprint liquid transfer part ＊ - L of the part where the artificial fingerprint liquid is not transferred ＊ However, the light incident angle is set to −30° with respect to the normal to the surface of the object to be measured, and the measurement angle is set to +30° with respect to the normal to the surface of the object to be measured.

2. a substrate, a predetermined layer disposed on the substrate, and an outermost layer disposed on the predetermined layer; the predetermined layer includes a first predetermined layer on the substrate side and a second predetermined layer on the outermost layer side, The laminate according to claim 1 , wherein the refractive index of the first predetermined layer is 2.00 or less.

3. a substrate, a predetermined layer disposed on the substrate, and an outermost layer disposed on the predetermined layer; the predetermined layer includes a first predetermined layer on the substrate side and a second predetermined layer on the outermost layer side, The laminate according to claim 1 , wherein the refractive index of the second predetermined layer is 1.43 or more and 1.49 or less.

4. On the surface of the laminate, ΔL at the light incident angle of −70° ＊ 2. The laminate according to claim 1, wherein the angular dependence of (θ) has a negative peak in the specular reflection region and a positive peak at angles other than the specular reflection region.

5. 2. The laminate according to claim 1, wherein the method for transferring the artificial fingerprint liquid comprises attaching the artificial fingerprint liquid to a transfer substrate by a spin coating method, preparing a transfer foil having a haze value of 7±2%, pressing a false finger against the transfer foil with a load of 60 N, and then pressing the false finger against the surface of the laminate with a load of 60 N for 2 seconds.

6. A display device comprising the laminate according to any one of claims 1 to 5.

7. The difference in measurement value ΔL between the area on the surface of the laminate where the artificial fingerprint liquid has been transferred and the area where it has not been transferred is calculated using a goniochromatic colorimeter according to the following formula (1): ＊ A method for producing a laminate, comprising producing the laminate so that (θ) is 0 or less: Formula (1) ΔL ＊ (θ) = L of the artificial fingerprint liquid transfer part ＊ - L of the part where the artificial fingerprint liquid is not transferred ＊ However, the light incident angle is set to −30° with respect to the normal to the surface of the object to be measured, and the measurement angle is set to +30° with respect to the normal to the surface of the object to be measured.

8. The difference ΔL in the measured values ​​between the area where the artificial fingerprint liquid has been transferred and the area where it has not been transferred is calculated using a goniochromatic colorimeter using the following formulas (1) and (2). ＊ (θ) and ΔC ＊ A laminate having a surface where (θ) satisfies the following formula (3): Formula (1) ΔL ＊ (θ) = L of the artificial fingerprint liquid transfer part ＊ - L of the part where the artificial fingerprint liquid is not transferred ＊ Formula (2) ΔC ＊ (θ) = {(a of the artificial fingerprint liquid transfer part ＊ - a of the artificial fingerprint liquid non-transfer area ＊ )^2+(b of the artificial fingerprint liquid transfer part ＊ - b of the artificial fingerprint liquid non-transfer area ＊ )^2}^(1 / 2) However, the light incident angle is set to −30° with respect to the normal to the surface of the object to be measured, and the measurement angle is set to +30°±15° with respect to the normal to the surface of the object to be measured. Formula (3) −25≦ΔL ＊ (θ)≦15 and ΔC ＊ (θ)≦15

9. Said ΔL ＊ (θ) and the ΔC ＊ The laminate according to claim 8, wherein (θ) satisfies the following formula (4): Formula (4) −5≦ΔL ＊ (θ)≦5 and ΔC ＊ (θ)≦5

10. A display device comprising the laminate according to claim 8 or 9.

11. The difference ΔL in the measured values ​​between the area on the surface of the laminate where the artificial fingerprint liquid has been transferred and the area where the artificial fingerprint liquid has not been transferred is calculated using a goniochromatic colorimeter according to the following formulas (1) and (2). ＊ (θ) and ΔC ＊ A method for producing a laminate, comprising producing the laminate so that (θ) satisfies the following formula (3): Formula (1) ΔL ＊ (θ) = L of the artificial fingerprint liquid transfer part ＊ - L of the part where the artificial fingerprint liquid is not transferred ＊ Formula (2) ΔC ＊ (θ) = {(a of the artificial fingerprint liquid transfer part ＊ - a of the artificial fingerprint liquid non-transfer area ＊ )^2+(b of the artificial fingerprint liquid transfer part ＊ - b of the artificial fingerprint liquid non-transfer area ＊ )^2}^(1 / 2) However, the light incident angle is set to −30° with respect to the normal to the surface of the object to be measured, and the measurement angle is set to +30°±15° with respect to the normal to the surface of the object to be measured. Formula (3) −25≦ΔL ＊ (θ)≦15 and ΔC ＊ (θ)≦15

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