TWI740932B - Touch panel, display device, optical sheet and screening method of optical sheet - Google Patents

Abstract

The present invention provides a touch panel, a display device, an optical sheet, and a screening method for an optical sheet that have outdoor anti-glare properties, can suppress the decrease in resolution, and have excellent operability of the touch panel.

The touch panel of the present invention has unevenness on the surface of the operator side, and the arithmetic mean roughness (Ra _2.5 ) of JIS B0601: 1994 when the cut-off value of the unevenness is set to 2.5 mm is 0.10 μm or more and 0.60 μm or less, and The friction coefficient of the above-mentioned uneven surface satisfies specific conditions.

Description

Touch panel, display device, optical sheet and screening method of optical sheet

The invention relates to a touch panel, a display device, an optical sheet, and a screening method of the optical sheet.

In recent years, display devices with touch panels equipped with touch panels in display devices have rapidly spread.

This type of display device with a touch panel is below the medium size (under 20 inches ~ 15 inches A4 type, under 15 inches ~ more than 11 inches B5 type), especially small (under 11 inches) The size of) is convenient for carrying, so it is mostly used outdoors or in a car, etc. where sunlight will enter the screen. Therefore, in order to prevent the reflection of sunlight, it is expected to impart anti-glare properties to the surface of the touch panel.

As an optical sheet imparting anti-glare properties, for example, Patent Document 1 is proposed.

[Patent Document 1] Japanese Patent Laid-Open No. 2013-178534

Patent Document 1 is excellent in anti-glare properties for indoor lighting. However, for too The anti-glare property of sunlight (outdoor anti-glare property) is not enough.

In addition, in recent years, touch panels have enabled various operations such as not only moving a finger in one direction, but also enlarging and reducing the screen on the touch panel. If an optical sheet with a high level of anti-glare properties is used as the surface material of the touch panel, there is a problem that the operability of the touch panel is likely to decrease as described above.

In Patent Document 1, no research has been done on both outdoor anti-glare properties and operability of the touch panel.

In addition, regarding the anti-glare film placed on the surface of the large-screen TV or PC monitor currently on the market, not only the operability of the touch panel is not considered, but also the anti-glare property against sunlight (outdoor anti-glare property) is not considered. ).

The present invention was completed in view of the actual situation, and its purpose is to provide a touch panel, display device, optical sheet, and The screening method of optical film.

In order to solve the above-mentioned problems, the present invention provides the following [1] to [8] touch panels, display devices, optical sheets, and screening methods of optical sheets.

[1] A touch panel having uneven surfaces on the operator side, a sapphire needle with a tip radius of 0.3 mm is vertically contacted with the unevenness, a vertical load of 100 g is applied to the squeegee needle, and the squeegee needle Perform a round trip with a length of 10 mm at a speed of 10mm/sec. Set the static friction coefficient acting on the squeegee at this time as μs ₁₀ ; make a sapphire squeegee with a tip radius of 0.3mm vertically contact the above-mentioned unevenness, A vertical load of 100g is applied to the squeegee needle, and at the same time, the squeegee needle is reciprocated once with a single pass length of 10mm at a speed of 20mm/sec. When the coefficient of static friction acting on the squeegee needle at this time is set to μs ₂₀ , μs ₁₀ And μs ₂₀ satisfies the following condition (A1), and regarding the above-mentioned unevenness, the arithmetic average roughness (Ra _2.5 ) of JIS B0601: 1994 when the cut-off value is set to 2.5 mm satisfies the following condition (A2).

0.70≦μs ₂₀ /μs ₁₀ ≦1.75 (A1)

0.10μm≦Ra _2.5 ≦0.60μm (A2)

[2] A display device in which the outermost surface of the exit surface of the display element has unevenness, a sapphire needle with a tip radius of 0.3mm is vertically contacted with the unevenness, and a vertical load of 100g is applied to the needle , And at the same time make the squeegee at a speed of 10mm/s to make a round trip with a length of 10mm in a single pass, set the static friction coefficient acting on the squeegee at this time as μs ₁₀ ; make the sapphire squeegee with a tip radius of 0.3mm In contact with the above-mentioned unevenness vertically, a vertical load of 100g is applied to the squeegee needle, and at the same time, the squeegee needle is reciprocated once with a single pass length of 10mm at a speed of 20mm/sec. Set the static friction coefficient acting on the squeegee needle at this time When it is μs ₂₀ , μs ₁₀ and μs ₂₀ satisfy the following conditions (A1). Regarding the above concavity and convexity, when the cut-off value is set to 2.5mm, the arithmetic average roughness (Ra _2.5 ) of JIS B0601: 1994 satisfies the following conditions (A2) .

0.70≦μs ₂₀ /μs ₁₀ ≦1.75 (A1)

0.10μm≦Ra _2.5 ≦0.60μm (A2)

[3] An optical sheet with unevenness on one side, a sapphire squeegee with a tip radius of 0.3mm is vertically in contact with the unevenness, a vertical load of 100g is applied to the squeegee, and the squeegee is set at a speed of 10mm/sec. Perform a round trip with a length of 10mm per pass. Set the coefficient of static friction acting on the squeegee at this time to μs ₁₀ , make a sapphire sapphire squeegee with a tip radius of 0.3mm vertically contact the above-mentioned unevenness, and apply a vertical to the squeegee Load 100g, and at the same time make the squeegee to make a round trip of 10mm at a speed of 20mm/sec. When the static friction coefficient acting on the squeegee is set to μs ₂₀ , μs ₁₀ and μs ₂₀ meet the following requirements Condition (A1), and regarding the above-mentioned unevenness, the arithmetic average roughness (Ra _2.5 ) of JIS B0601: 1994 when the cut-off value is set to 2.5 mm satisfies the following condition (A2).

0.70≦μs ₂₀ /μs ₁₀ ≦1.75 (A1)

0.10μm≦Ra _2.5 ≦0.60μm (A2)

[4] A screening method for optical sheets, which is a screening method for optical sheets with concavities and convexities on one side. The screening method selects the following optical sheets as the optical sheets located on the uppermost part of the touch panel, with a front end radius of 0.3mm made of sapphire The squeegee needle is vertically in contact with the above-mentioned unevenness, a vertical load of 100g is applied to the squeegee needle, and at the same time, the squeegee needle is reciprocated once with a single pass length of 10mm at a speed of 10mm/sec. The coefficient of static friction is set to μs ₁₀ ; a sapphire needle with a tip radius of 0.3mm is vertically in contact with the above-mentioned unevenness, a vertical load of 100g is applied to the squeegee, and the squeegee is made to perform a single pass at a speed of 20mm/sec. The length is One round trip of 10mm, when the coefficient of static friction acting on the squeegee at this time is set to μs ₂₀ , when μs ₁₀ and μs ₂₀ meet the following condition (A1), and when the cut-off value is set to 2.5 mm for the above-mentioned unevenness The arithmetic average roughness (Ra _2.5 ) of JIS B0601: 1994 satisfies the following condition (A2).

0.70≦μs ₂₀ /μs ₁₀ ≦1.75 (A1)

0.10μm≦Ra _2.5 ≦0.60μm (A2)

[5] A touch panel having irregularities on the surface of the operator side, and the irregularities satisfy the following conditions (B1) and (B2).

Condition (B1): A sapphire squeegee with a tip radius of 0.3mm is vertically in contact with the above-mentioned unevenness, a vertical load Tg is applied to the above-mentioned squeegee, and at the same time, the squeegee is made to perform a single pass length of 10mm at a speed of 5mm/sec. Go back and forth once, measure the coefficient of static friction acting on the above-mentioned scraping needle at this time μs and coefficient of dynamic friction μk. In the graph drawn with the ratio of the static friction coefficient μs to the dynamic friction coefficient μk (μs/μk) as the vertical axis and the vertical load Tg as the horizontal axis, the curve in the range of the vertical load 100~1000g is used as When the least square method is approximated by a straight line, the slope of the above straight line is negative.

Condition (B2): Regarding the above-mentioned unevenness, the arithmetic mean roughness (Ra2.5) of JIS B0601: 1994 when the cut-off value is 2.5 mm is 0.10 μm or more and 0.60 μm or less.

[6] A display device having unevenness on the outermost surface on the exit surface side of the display element, and the unevenness satisfies the following conditions (B1) and (B2).

Condition (B1): A sapphire squeegee with a tip radius of 0.3mm is vertically in contact with the unevenness, a vertical load Tg is applied to the squeegee, and the squeegee is made to perform a single pass at a speed of 5mm/sec. The length is 10mm Measure the static friction coefficient μs and the dynamic friction coefficient μk acting on the above-mentioned scraping needle at this time. In the graph drawn with the ratio of the static friction coefficient μs to the dynamic friction coefficient μk (μs/μk) on the vertical axis and the vertical load Tg on the horizontal axis, the curve in the range of the vertical load 100~1000g is drawn by the maximum When the Xiaoping method is approximated by a straight line, the slope of the above straight line is negative.

Condition (B2): Regarding the above-mentioned unevenness, the arithmetic mean roughness (Ra2.5) of JIS B0601: 1994 when the cut-off value is 2.5 mm is 0.10 μm or more and 0.60 μm or less.

[7] An optical sheet having irregularities on one surface, and the irregularities satisfy the following conditions (B1) and (B2).

Condition (B1): A sapphire squeegee with a tip radius of 0.3mm is vertically in contact with the above-mentioned unevenness, a vertical load Tg is applied to the above-mentioned squeegee, and at the same time, the squeegee is made to perform a single pass length of 10mm at a speed of 5mm/sec. Go back and forth once, measure the coefficient of static friction acting on the above-mentioned scraping needle at this time μs and coefficient of dynamic friction μk. In the graph drawn with the ratio of the static friction coefficient μs to the dynamic friction coefficient μk (μs/μk) on the vertical axis and the vertical load Tg on the horizontal axis, the curve in the range of the vertical load 100~1000g When approximating with a straight line by the least square method, the slope of the above straight line is negative.

Condition (B2): Regarding the above-mentioned unevenness, the arithmetic mean roughness (Ra2.5) of JIS B0601: 1994 when the cut-off value is 2.5 mm is 0.10 μm or more and 0.60 μm or less.

[8] A method for screening optical sheets, which selects an optical sheet with unevenness on one side, and the above-mentioned unevenness satisfies the following conditions (B1) and (B2) as an optical sheet located on the uppermost part of the touch panel.

Condition (B1): A sapphire squeegee with a tip radius of 0.3mm is vertically in contact with the above-mentioned unevenness, a vertical load Tg is applied to the above-mentioned squeegee, and at the same time, the squeegee is made to perform a single pass length of 10mm at a speed of 5mm/sec. Go back and forth once, and measure the coefficient of static friction μs and the coefficient of dynamic friction μk acting on the above-mentioned scraper at this time. In the graph drawn with the ratio of the static friction coefficient μs to the dynamic friction coefficient μk (μs/μk) as the vertical axis and the vertical load Tg as the horizontal axis, the curve in the range of the vertical load 100~1000g is used as When the least square method is approximated by a straight line, the slope of the above straight line is negative.

Condition (B2): Regarding the above-mentioned unevenness, the arithmetic mean roughness (Ra2.5) of JIS B0601: 1994 when the cut-off value is 2.5 mm is 0.10 μm or more and 0.60 μm or less.

According to the present invention, it is possible to provide a touch panel, a display device, an optical sheet, and a screening method of an optical sheet that have outdoor anti-glare properties, can suppress the decrease in resolution, and have excellent operability of the touch panel.

1‧‧‧Resistive film touch panel

11‧‧‧Transparent substrate

12‧‧‧Transparent conductive film

13‧‧‧Spacer

2‧‧‧Electrostatic capacitive touch panel

21‧‧‧Transparent substrate

22‧‧‧Transparent conductive film (X-axis electrode)

23‧‧‧Transparent conductive film (Y-axis electrode)

24‧‧‧Adhesive layer

FIG. 1 is a cross-sectional view showing an embodiment of the resistive film type touch panel of the present invention.

Fig. 2 is a cross-sectional view showing an embodiment of the capacitive touch panel of the present invention.

Fig. 3 is a diagram for explaining the calculation method of the average inclination angle θa.

Figure 4 shows the unevenness of the optical sheet of the present invention, when the ratio of static friction coefficient μs to dynamic friction coefficient μk (μs/μk) is set on the vertical axis, and the vertical load Tg is set on the horizontal axis. The curve in the range of 100~1000g is a graph that approximates a straight line obtained by the least square method.

Hereinafter, regarding the touch panel, the display device, the optical sheet, and the screening method of the optical sheet of the present invention, the embodiment A and the embodiment B are taken as examples for description.

<Embodiment A>

[Touch Panel]

The touch panel of Embodiment A is one with uneven surfaces on the operator side. A sapphire needle with a tip radius of 0.3 mm is placed in vertical contact with the unevenness, a vertical load of 100 g is applied to the needle, and the scratch The needle makes one round trip with a length of 10mm at a speed of 10mm/sec. At this time, the static friction coefficient acting on the squeegee is set to μs ₁₀ , and the sapphire squeegee with a tip radius of 0.3mm is vertically in contact with the above-mentioned unevenness. , Apply a vertical load of 100g to the squeegee needle, and at the same time perform a round trip with a length of 10mm at a speed of 20mm/sec. At this time, when the _{coefficient of static friction acting on the squeegee needle is set to μs 20 , μs 10} and μs _{20 The following condition (A1) is satisfied, and the arithmetic average roughness (Ra 2.5} ) of JIS B0601: 1994 when the cut-off value is set to 2.5 mm for the above-mentioned unevenness meets the following condition (A2).

0.70≦μs ₂₀ /μs ₁₀ ≦1.75 (A1)

0.10μm≦Ra _2.5 ≦0.60μm (A2)

In Embodiment A, the "surface on the operator's side" refers to the surface that the operator actually touches and operates when operating the touch panel.

Examples of touch panels include electrostatic capacitive touch panels, resistive film touch panels, optical touch panels, ultrasonic touch panels, electromagnetic induction touch panels, and the like.

These touch panels have transparent substrates such as glass substrates and plastic film substrates, and there are cases where concavities and convexities useful for imparting anti-glare properties are formed on the transparent substrate. The touch panel of Embodiment A has, for example, the following optical sheet on the uppermost part as such a member having irregularities on a transparent substrate.

The resistive film type touch panel 1 is shown in FIG. 1, and a circuit not shown is connected to the conductive film 12 having the next pair of transparent substrates 11 on the conductive film 12 and arranged with spacers 13 in between. Into the basic composition. In the case of a resistive film type touch panel, in Embodiment A, the following optical sheet is used as the upper transparent substrate. By using the following optical sheet as the upper transparent substrate of the resistive film type touch panel as described above, the concave-convex shape of the optical sheet can be used to impart outdoor anti-glare properties to the touch panel and change the operability of the touch panel. It's excellent. In addition, the reduction in resolution can be suppressed.

Furthermore, the above-mentioned optical sheet can also be used as a lower transparent substrate in addition to being used as an upper transparent substrate.

Capacitive touch panels include surface type and projection type, and more projections are used type. The projection type electrostatic capacitive touch panel is a basic structure in which an X-axis electrode and a Y-axis electrode orthogonal to the X-axis electrode are arranged with an insulator interposed between a circuit and a circuit. To describe the basic structure more specifically, it can be mentioned that the X-axis electrode and the Y-axis electrode are formed on different sides of a transparent substrate; the X-axis electrode, the insulator layer, and the The state of the Y-axis electrode; as shown in FIG. 2, the X-axis electrode 22 is formed on one transparent substrate 21, the Y-axis electrode 23 is formed on the other transparent substrate 21, and the layer is laminated through the adhesive layer 24, etc. Wait. In addition, another transparent substrate may be laminated among the basic patterns.

In the case of an electrostatic capacitive touch panel, in Embodiment A, the following optical sheet is used as the uppermost transparent substrate. By using the following optical sheet as the uppermost transparent substrate of an electrostatic capacitive touch panel as described above, the concave-convex shape of the optical sheet can be used to impart outdoor anti-glare properties to the touch panel and make the touch panel more effective. The operability becomes excellent. In addition, the reduction in resolution can be suppressed.

The touch panel as described above is used, for example, as an in-cell type touch panel arranged on a display element.

(Optical Sheet)

The optical sheet of the embodiment A has unevenness on one surface, and the unevenness satisfies the above-mentioned conditions (A1) and (A2).

The touch panel may require different operating speeds. In condition (A1), if μs ₂₀ /μs _{10 is} less than 0.70, the screen scrolling operation feeling cannot be obtained, and/or the enlargement/reduction operation cannot be smoothly performed. If it exceeds 1.75, the scroll operation cannot be smoothly performed, and/or the operation feeling of zooming in/out cannot be obtained.

In contrast, when the optical sheet of Embodiment A satisfies the condition (A1), when the touch During any operation of the panel, the degree of finger jam at the beginning of the operation can be made to the same degree, and the operability can be improved.

The condition (A1) preferably satisfies 0.80≦μs ₂₀ /μs ₁₀ ≦1.60, more preferably satisfies 0.85≦μs ₂₀ /μs ₁₀ ≦1.25, and more preferably satisfies 0.85≦μs ₂₀ /μs ₁₀ ≦1.15.

Furthermore, in the embodiment A, the static friction coefficient is set to be the peak value of the initial friction force above the dynamic friction coefficient with the elapse of the measurement time from the friction force 0.

In addition, from the viewpoint of improving operability, μs ₂₀ and μs _{10 are} preferably in the following ranges. μs _{20 is} preferably 0.10 to 0.26, more preferably 0.11 to 0.25, and still more preferably 0.12 to 0.24. μs _{10 is} preferably 0.12 to 0.18, more preferably 0.13 to 0.17, and still more preferably 0.14 to 0.16.

In addition, in the condition (A2), the cut-off value is 2.5 mm. The cut-off value is a value indicating the degree to which the waviness component is cut off from the profile curve composed of the roughness component (high-frequency component) and the waviness component (low-frequency component). In other words, the cutoff value represents the fineness of the filter that cuts the waviness component (low frequency component) from the profile curve. If the cutoff value is large, the filter is sparse, so the large ripples in the waviness component will be cut off, but the small ripples will not be cut off. On the other hand, if the cutoff value is small, the filter is denser, so the waviness component is basically cut off. In JIS B0633 referred to in JIS B0601, when the arithmetic average roughness Ra is 0.1 to 2 μm, the cut-off value (reference length) is set to 0.8 mm. Therefore, according to JIS B0633, in the case of Ra in the above condition (A2), the standard is to set the cut-off value (reference length) to 0.8 mm.

However, the touch, outdoor anti-glare properties and resolution during operation are not only affected by roughness components (high frequency components), but also by waviness components (low frequency components). Therefore, the cutoff value (reference length ) Is set to 0.8mm, the degree of the waviness component (low frequency component) of the roughness curve is cut off, and it cannot be evaluated that it is more easily affected than outdoor anti-glare and resolution. The impact of low-frequency components may cause tactile operation during operation. Therefore, in the embodiment A, the cut-off value of the condition (A2) is set to 2.5 mm.

The arithmetic average roughness Ra _2.5 of the condition (A2) is 0.10 μm or more and 0.60 μm or less. If Ra _{2.5 is} less than 0.10 μm, light scattering is insufficient and anti-glare properties are reduced. In addition, the contact area between the finger and the surface of the optical sheet increases and the tactile feel (slidability) deteriorates. If Ra _2.5 exceeds 0.60 μm, sliding properties during operation will be impaired, and contrast and resolution will decrease. From the viewpoints of touch during operation, outdoor anti-glare properties, and resolution, condition (A2) preferably satisfies 0.15 μm≦Ra _2.5 ≦0.60 μm, and more preferably satisfies 0.25 μm≦Ra _2.5 ≦0.55 μm.

In addition, if the arithmetic average roughness Ra _2.5 is 0.10 μm or more, the color unevenness of the gradation peculiar to the retardation value of the transparent substrate can be made less noticeable. The so-called color unevenness of the gradual color peculiar to the retardation value is the color unevenness of the rainbow pattern produced by the light passing through the transparent substrate with the retardation value. Such color unevenness is recognized through the polarizing plate through polarized sunglasses, for example. , It is observed when the light of a transparent substrate with a specific retardation value.

Furthermore, by satisfying the following conditions (A3) to (A5) in addition to the above condition (A2), it becomes easier to satisfy the above condition (A1). Especially when Ra _2.5 is 0.25 μm or more, for display elements with a wide color gamut, for example, the color unevenness of the gradation color can be made more difficult to notice.

Moreover, it is preferable that the above-mentioned irregularities satisfy the following condition (A3) _{with the ten-point average roughness (Rz 2.5} ) of JIS B0601:1994 and the above-mentioned Ra _{2.5 when the cut-off value is set to 2.5 mm.}

5.7≦Rz _2.5 /Ra _2.5 (A3)

The so-called arithmetic average roughness Ra is the value obtained by integrating the absolute values of the elevations of the peaks and valleys of the roughness curve of the evaluation length and dividing by the evaluation length, in the form of an equal elevation. On the other hand, the so-called ten-point average roughness Rz is to take the value equal to the cutoff value. The roughness curve of the evaluation length that is N times the sample length is divided into N equal parts, and the average elevation of the peak top from the first to the fifth place in each interval height and the average elevation of the valley bottom from the first to the fifth place in the depth are calculated. The arithmetic average of N Rz's at the interval Rz'. That is, Ra is the average value of the elevation of the entire roughness curve, while Rz is the average value of the elevations at the 5 higher and 5 lower points in the roughness curve. Therefore, when the roughness curve does not have randomness, Ra and Rz are approximately the same, but when the roughness curve has randomness, Rz becomes larger than Ra. Therefore, Rz/Ra becomes an index indicating the randomness of the roughness curve.

If Rz _2.5 /Ra _2.5 is 5.7 or more, the randomness of the roughness curve is improved, the contact area between the finger and the surface of the optical sheet is reduced, and the tactility becomes better. In addition, by increasing the randomness of the roughness curve, there is a tendency that for display elements with a wide color gamut, the color unevenness of the gradual color can be made more difficult to notice. Furthermore, from the viewpoint of tactile feel (slidability) and resolution, the roughness is preferably such that the randomness is not excessive.

The condition (A3) is more preferably 6.0≦Rz _2.5 /Ra _2.5 ≦10.0, more preferably 6.5≦Rz _2.5 /Ra _2.5 ≦9.5, and still more preferably 7.0≦Rz _2.5 /Ra _2.5 ≦9.0.

_{Furthermore, the Rz 2.5 of the} aforementioned concavities and convexities is preferably 0.50 to 4.30 μm, more preferably 1.00 to 4.00 μm, and still more preferably 2.00 to 4.00 μm. If Rz _2.5 is 0.50 μm or more, outdoor anti-glare properties can be imparted to the touch panel, and the touch (slidability) can be improved. If Rz _2.5 is 4.30μm or less, the generation of glare can be suppressed, and the sliding property during operation will not be impaired.

Furthermore, if Rz _2.5 is 2.00 μm or more, for example, for a display element with a wide color gamut, the color unevenness of the gradation peculiar to the retardation value of the transparent substrate can be made more difficult to notice.

In addition, with regard to the above-mentioned unevenness, it is preferable that the average interval between local peak tops (S _2.5 ) of JIS B0601: 1994 when the cut-off value is set to 2.5 mm satisfies the following condition (A4).

S _2.5 ≦70μm (A4)

If the average distance between local peak tops (S _2.5 ) is 70 μm or less, the contact area between the finger and the surface of the optical sheet is reduced, and the touch (slidability) can be improved.

The condition (A4) preferably satisfies S _2.5 ≦65 μm, more preferably satisfies 20 μm≦S _2.5 ≦60 μm, and more preferably satisfies 30 μm≦S _2.5 ≦55 μm.

Furthermore, with regard to the aforementioned concavities and convexities, it is preferable that the ten-point average roughness (Rz _0.8 ) of JIS B0601: 1994 and the aforementioned Rz _2.5 satisfy the following condition (A5) when the cutoff value is 0.8 mm.

0.10μm≦Rz _{2.5 -Rz 0.8} ≦1.20μm (A5)

As described above, the cut-off value is a value indicating the degree to which the cross-sectional profile formed by the free roughness component (high-frequency component) and the waviness component (low-frequency component) cuts off the waviness component. Therefore, Rz _{2.5- Rz 0.8} can be said to be an indicator of the degree of influence of the waviness component on Rz.

When the condition (A5) is satisfied, the static friction coefficient can be easily made the same level when the unevenness is contacted at a low speed and when the unevenness is contacted at a high speed. The operation of the touch panel can be roughly divided into: the operation of scrolling the screen, and the operation of expanding or shrinking the display. In the former operation and the latter operation, the former operation tends to move the finger faster. In addition, according to the speed of moving the finger, the easiness of the finger stoppage of the waviness component is different. That is, when the condition (A5) is satisfied, any operation of the touch panel can easily make the degree of finger jam (the coefficient of static friction) at the beginning of the operation the same degree. In addition, by setting Rz _{2.5- Rz 0.8} within the above range, glare can be easily suppressed.

The condition (A5) preferably satisfies 15 μm≦Rz _2.5 -Rz _0.8 ≦0.80 μm, and more preferably satisfies 0.20 μm≦Rz _2.5 -Rz _0.8 ≦0.50 μm.

Furthermore, from the viewpoint of making it difficult to notice the color unevenness of the gradation color peculiar to the retardation value of the transparent substrate, Rz _{2.5- Rz 0.8} preferably exceeds 0.50 μm, and more preferably exceeds 0.80 μm.

In terms of any operation of the touch panel, it is easy to make the degree of finger jam (static friction coefficient) at the same level at the beginning of the operation, the above-mentioned unevenness is preferably Rz _2.5 /Rz _{0.8 to} satisfy the following conditions.

Rz _2.5 /Rz _0.8 ≦1.50

Furthermore, from the viewpoint of suppressing glare and the viewpoint of making the color unevenness of the gradation color peculiar to the retardation value of the transparent substrate less conspicuous, Rz _2.5 /Rz _0.8 is more preferably 1.20 or more and 1.50 or less, and further Preferably it is 1.25 or more and 1.35 or less.

Furthermore, regarding the above-mentioned unevenness, it is preferable that the maximum height (Ry _2.5 ) of JIS B0601:1994 when the cut-off value is set to 2.5 mm satisfies the following conditions.

0.60μm≦Ry _2.5 ≦5.0μm

If Ry _2.5 is 5.0μm or less, it can prevent finger jam during operation and make the touch feel better. In addition, the generation of glare can be prevented more. If Ry _2.5 is 0.60 μm or more, outdoor anti-glare properties can be imparted.

Moreover, from the viewpoint of easily satisfying the following conditions (A6) and (A7), Ry _2.5 is more preferably 1.0 μm or more and 4.7 μm or less, and still more preferably 1.2 μm or more and 4.5 μm or less.

Furthermore, it is preferable that the above-mentioned unevenness is such that the above-mentioned (Ry _2.5 ) and the above-mentioned Rz _2.5 satisfy the following condition (A6).

Ry _2.5 /Rz _2.5 ≦1.5 (A6)

If Ry _2.5 /Rz _2.5 is 1.5 or less, it can prevent finger jam during operation and make the touch feel better. In addition, the generation of glare can be prevented more, and outdoor anti-glare properties can be easily imparted.

Ry _2.5 /Rz _2.5 is more preferably 1.10 or more and 1.40 or less, and still more preferably 1.18 or more and 1.38 or less.

Furthermore, with regard to the aforementioned concavities and convexities, it is preferable that the average inclination angle (θa _2.5 ) of the concavities and convexities when the cut-off value is set to 2.5 mm satisfies the following conditions.

1.0°≦θa _2.5 ≦5.5°

If θa _2.5 is 1.0° or more, outdoor anti-glare properties can be imparted to the touch panel, and the touch (slidability) during operation can be improved. If θa _2.5 is 5.5° or less, the decrease in contrast can be suppressed, and the outdoor anti-glare property and contrast can be balanced. θa _2.5 preferably satisfies 1.3°≦θa _2.5 ≦4.5°, and further preferably satisfies 2.0°≦θa _2.5 ≦4.0°. In addition, if θa _2.5 is 1.3° or more, the color unevenness of the gradation peculiar to the retardation value of the transparent substrate can be made difficult to notice. Furthermore, if it is 2.0° or more, for example, for a display element with a wide color gamut, the color unevenness of the gradation color can be made more difficult to notice.

Here, the "average inclination angle θa" is the value defined in the operation manual (1995.07.20 revision) of the surface roughness measuring instrument (trade name: SE-3400) manufactured by Kosaka Research Laboratory, as shown in Figure 3. may be present in the reference length L by the height of the convex portion and _{(h 1 + h 2 + h} 3 + ‧‧‧ + h n) of the arctangent _{^{θa = tan -1 {(h 1}} + h 2 + h 3 +‧‧‧+h _n )/L}.

In addition, θa can be calculated according to the following formula (A).

[In formula (A), "L" represents the reference length, and "dy/dx" represents the slope of each unit interval of the roughness curve].

Furthermore, the so-called "reference length" means "cut-off value". That is, when the cutoff value is 0.8 mm, the reference length is 0.8 mm. Also, the so-called unit measurement interval is the interval obtained by dividing the cut-off value by the number of samples. The number of samples is set to 1500.

Furthermore, it is preferable that the aforementioned concavities and convexities are such that the aforementioned (θa _2.5 ) and the aforementioned Ry _2.5 /Rz _2.5 satisfy the following condition (A7).

0.8≦θa _2.5 /(Ry _2.5 /Rz _2.5 )≦5.0 (A7)

If θa _2.5 /(Ry _2.5 /Rz _2.5 ) is in the above range, it becomes unevenness with moderate randomness, and can provide anti-glare, resolution, touch (slidability) during operation, and make The color unevenness of the gradation that is unique to the retardation value of the transparent substrate is difficult to notice and the balance becomes good.

θa _2.5 /(Ry _2.5 /Rz _2.5 ) is more preferably 1.0 or more and 4.5 or less. Even in the case of a display element with a wide color gamut, the color unevenness of the gradation color can be made difficult to notice, so it is more preferably 2.0 or more and 4.0 or less.

Furthermore, with regard to the aforementioned concavities and convexities, it is preferable that the average interval (Sm _2.5 ) of concavities and convexities of JIS B0601: 1994 when the cut-off value is set to 2.5 mm satisfies the following conditions.

Sm _2.5 ≦160μm

If Sm _2.5 is 160 μm or less, the contact area between the finger and the surface of the optical sheet is reduced, and the touch (slidability) can be improved. Sm _{2.5 is more} preferably 150 μm or less, and still more preferably 145 μm or less. In addition, the lower limit is preferably 30 μm or more, more preferably 50 μm or more, and still more preferably 100 μm or more.

Furthermore, the _{smaller Sm 2.5} is, the more the glare can be suppressed even for high-definition displays.

As a method of forming the above-mentioned unevenness, for example, (x1) physical or chemical treatments such as embossing, sandblasting, and etching, (x2) molding with a mold, (x3) formation of an uneven layer by coating, and the like. Among these methods, from the viewpoint of the reproducibility of the concave-convex shape, it is preferable to use (x2) molding with a mold, and from the viewpoint of productivity and the corresponding variety, it is preferable to use (x3) the concave-convex by coating The formation of layers.

Molding using a mold can be formed by making a mold composed of a shape complementary to the unevenness, flowing the uneven-forming material into the mold, and then taking it out of the mold. Here, if the material constituting the concavities and convexities is used as the material, the material is poured into the mold and then the transparent substrate is superimposed, and the concavities and convexities are taken out from the mold together with the transparent substrate, then an optical sheet with concavities and convexities on the transparent substrate can be obtained . In addition, if the material constituting the transparent substrate is poured into the mold and then taken out from the mold, an optical sheet composed of a single layer of the transparent substrate and having unevenness on the surface of the transparent substrate can be obtained.

When a curable resin composition (thermosetting resin composition or ionizing radiation curable resin composition) is used as the material to be poured into the mold, it is preferable to harden the curable resin composition before taking it out of the mold.

In terms of excellent reproducibility of the uneven shape, it is preferable to form the unevenness with a mold.

The concave-convex layer formed by coating can be formed by applying a coating solution for forming a concave-convex layer containing resin components and particles on a transparent substrate by a well-known coating method such as gravure coating and bar coating. It can be formed by drying and hardening as needed. In order for the uneven layer to satisfy the above-mentioned conditions (A1) and (A2), it is preferable to set the film thickness of the uneven layer, the content of particles, and the average particle diameter of the particles within the following ranges.

The film thickness of the concavo-convex layer is preferably 1.5-10 μm, more preferably 2-8 μm, and still more preferably 3-7 μm. The film thickness of the concave-convex layer can be measured at 20 locations based on the cross-sectional image taken by a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM), and the average value of the 20 locations And figure it out. The acceleration voltage of TEM or STEM is preferably set to 1 to 5 kV, and the magnification is preferably set to 1000 to 10,000 times.

Any of organic particles and inorganic particles can be used as the particles as long as they can form irregularities. Examples of organic particles include: polymethylmethacrylate, polyacrylic acid-benzene Particles composed of ethylene copolymer, melamine resin, polycarbonate, polystyrene, polyvinyl chloride, benzoguanamine-melamine-formaldehyde condensate, polysiloxane, fluorine-based resin, and polyester-based resin. Examples of inorganic particles include particles composed of silica, alumina, zirconia, and titanium oxide. Among these particles, from the viewpoint of ease of dispersion control, light-transmitting organic particles or silica particles are preferred.

The above-mentioned particles can be used alone or in combination of two or more of different materials or particle sizes.

In addition, in order to make the color unevenness of the gradation color less noticeable even in the case of a display element with a wide color gamut, the particles are preferably amorphous particles having a particle size above the wavelength of visible light. Since the uneven layer contains irregular particles, the uneven color of the gradation can be suppressed.

The content of the particles is preferably 5-25% by mass, more preferably 6-22% by mass, and still more preferably 10-20% by mass of the total solid components forming the uneven layer.

The average particle size of the particles in the uneven layer is different depending on the thickness of the uneven layer, so it cannot be generalized, but from the viewpoint of easily satisfying the condition (A1) and the condition (A2), it is preferably 1.0 to 10.0 μm, more preferably It is 1.5 to 8.0 μm, more preferably 2.0 to 6.0 μm. In the case of agglomeration of particles, the average particle diameter of the agglomerated particles preferably satisfies the above-mentioned range.

The average particle size of the particles can be calculated by the following operations (y1) ~ (y3).

(y1) Select the largest particle in the observation frame from the cross-sectional images taken by the transmission electron microscope (TEM) or the scanning transmission electron microscope (STEM). The acceleration voltage of TEM or STEM is preferably set to 1-30 kV, and the magnification is preferably set to 5000 to 300,000 times.

(y2) Select the particles with the largest diameter from the observation image, and calculate the particle size of each particle. The particle size is measured in the form of the distance between the straight lines, and the distance between the straight lines is any two parallel lines. When a straight line clamps the cross section of the particle, the distance between the two straight lines becomes the distance between the two largest straight lines in the combination.

(y3) Perform the same operation on the observation image of another screen of the same sample, and set the value obtained from the number average of the total 20 particle diameters as the average particle diameter of the particles.

Furthermore, in the case of agglomerated particles, the largest diameter part of the agglomerated mass is regarded as the particle size.

In addition, the average particle diameter of the following ultrafine particles can be calculated by the same method as (y1) to (y3) above. When calculating the average particle size of the ultrafine particles, the acceleration voltage of TEM or STEM is preferably set to 10kv~30kV, and the magnification is preferably set to 10,000~300,000 times.

From the viewpoint that the uneven layer easily satisfies the above-mentioned conditions (A1) and (A2), the film thickness of the uneven layer is preferably larger than the average particle diameter of the particles. Furthermore, more specifically, the ratio of [average particle diameter of particles]/[film thickness of uneven layer] is preferably 0.20 to 0.99, and more preferably 0.50 to 0.90.

The particles can also be those with a wide particle size distribution (a single particle with a wide particle size distribution, or a mixed particle formed by mixing two or more particles with different particle size distributions and a wide particle size distribution), from the viewpoint of suppressing glare In general, those with a narrower particle size distribution are preferred.

Furthermore, as the particles, it is preferable to contain not only the above-mentioned micron-sized particles but also nano-sized ultrafine particles. By containing nano-level ultrafine particles, the uneven layer can easily satisfy the above-mentioned conditions (A1) and (A2). It can be considered that the reason is that when ultrafine particles are contained, a gentle slope is formed even where there are no particles, and low-frequency bumps are formed (cut off at a cut-off value of 0.8mm, but not at a cut-off value of 2.5mm. Truncated bumps). In the case of containing ultrafine particles, the thixotropy of the coating liquid and the drying characteristics of the solvent will be affected, and the usual leveling will not occur, so it is believed that the above-mentioned phenomenon will occur.

The ultrafine particles are preferably inorganic fine particles. Examples of inorganic ultrafine particles include: Ultrafine particles composed of silica, alumina, zirconia and titania. Among them, from the viewpoint of transparency, ultrafine silica particles are preferred.

The ultrafine particles preferably have an average primary particle size of 1-25 nm, more preferably 5-20 nm. If it is in the above range, the uneven layer will easily satisfy the above-mentioned conditions (A1) and (A2).

The ultrafine particles are preferably surface-treated ultrafine particles, or further reactive ultrafine particles with reactive groups introduced. By introducing surface treatment, it becomes easy to achieve balance with the organic binder or solvent in the uneven layer, and the uneven layer can easily satisfy the above-mentioned conditions (A1) and (A2). Examples of such surface-treated ultrafine particles include inorganic ultrafine particles that have been surface-treated with a silane coupling agent. When using a silane coupling agent to treat the surface of the inorganic ultrafine particles, examples include: the dry method of spraying the silane coupling agent onto the inorganic ultrafine particles; or dispersing the inorganic ultrafine particles in a solvent and then adding the silane coupling agent to react them. Wet method, etc.

In the case of introducing a reactive group, a polymerizable unsaturated group can be preferably used, preferably a photocurable unsaturated group, and particularly preferably an ionizing radiation curable unsaturated group. Specific examples thereof include (meth)acryloyl groups, (meth)acryloyloxy groups, ethylenic unsaturated bonds such as vinyl groups and allyl groups, epoxy groups, and the like.

The content of ultrafine particles is preferably 0.2-60% by mass of all solid components forming the uneven layer. The content of the ultrafine particles can be adjusted depending on the purpose of using the ultrafine particles. From the viewpoint of improving the hardness or scratch resistance, it is preferably 15-50% by mass. From the viewpoint of the improvement of optical properties and the preparation of unevenness, it is more Preferably, it is 0.4 to 10% by mass. In addition, by setting it within the above range, the uneven layer can easily satisfy the above-mentioned conditions (A1) and (A2) by controlling the leveling properties and suppressing the polymerization shrinkage of the uneven layer.

Also, when other particles are included in the uneven layer, the content of other particles and ultrafine particles The ratio (content of other particles/content of ultrafine particles) is preferably 0.05 to 3.0, more preferably 0.1 to 1.5, and the upper limit is preferably 0.7 or less. By setting it within the above-mentioned range, the uneven layer can easily satisfy the above-mentioned conditions (A1) and (A2). Furthermore, by only agglomerating ultrafine particles, it is also possible to make particles of the μm order to form unevenness.

The resin component of the concavo-convex layer preferably contains a thermosetting resin composition or an ionizing radiation curable resin composition, and from the viewpoint of improving the mechanical strength, it is more preferable to contain an ionizing radiation curable resin composition. Among them, Furthermore, it is preferable to contain an ultraviolet curable resin composition.

The thermosetting resin composition is a composition containing at least a thermosetting resin, and is a resin composition that is cured by heating.

Examples of thermosetting resins include acrylic resins, urethane resins, phenol resins, urea melamine resins, epoxy resins, unsaturated polyester resins, silicone resins, and the like. In the thermosetting resin composition, a curing agent is added to the curable resin as necessary.

The ionizing radiation curable resin composition is a composition containing a compound having an ionizing radiation curable functional group (hereinafter, also referred to as "ionizing radiation curable compound"). Examples of the ionizing radiation-curable functional group include ethylenically unsaturated bonding groups such as (meth)acryloyl, vinyl, and allyl groups, epoxy groups, and oxetanyl groups. The ionizing radiation curable compound is preferably a compound having an ethylenically unsaturated bond group, more preferably a compound having two or more ethylenically unsaturated bond groups, and among them, it is more preferably a compound having two or more ethylenically unsaturated bond groups. Multifunctional (meth)acrylate compound of ethylenically unsaturated bond group. As the polyfunctional (meth)acrylate compound, both monomers and oligomers can be used.

Furthermore, the so-called ionizing radiation refers to the presence of electromagnetic waves or charged particle beams that can polymerize molecules Or cross-linked energy quantum, usually ultraviolet (UV) or electron beam (EB) can be used. In addition, electromagnetic waves such as X-rays and γ-rays; charged particle beams such as α-rays and ion beams can also be used.

Among the polyfunctional (meth)acrylate-based compounds, examples of bifunctional (meth)acrylate-based monomers include ethylene glycol di(meth)acrylate and bisphenol A tetraethoxy diacrylate , Bisphenol A tetrapropoxy diacrylate, 1,6-hexanediol diacrylate, dicyclopentenyl di(meth)acrylate, triethylene glycol diacrylate, tetraethylene glycol di( Meth) acrylate, tricyclodecanediyl dimethylene di(meth)acrylate, tris(2-hydroxyethyl) trimer isocyanate di(meth)acrylate, etc.

Examples of (meth)acrylate monomers having trifunctional or higher functions include trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, and neopentylerythritol Tris(meth)acrylate, neopentyl erythritol tetra(meth)acrylate, neopentyl erythritol hexa(meth)acrylate, di-trimethylolpropane tetra(meth)acrylate, dinepentyl Tetraol hexa (meth) acrylate, dineopentyl erythritol penta (meth) acrylate, dineopentaerythritol tetra (meth) acrylate, di-trimethylolpropane tetra (meth) acrylate , Tris (2-hydroxyethyl) trimeric isocyanate, tris (meth) acrylate, etc.

In addition, the above-mentioned (meth)acrylate-based monomers can also be modified as part of the molecular skeleton, and can also be used with ethylene oxide, propylene oxide, caprolactone, isocyanuric acid, alkyl, Modified cyclic alkyl, aromatic, bisphenol, etc.

In addition, as polyfunctional (meth)acrylate oligomers, urethane (meth)acrylate, epoxy (meth)acrylate, polyester (meth)acrylate, and polyester (meth)acrylate can be cited. ) Acrylate-based polymers such as acrylates and polyether (meth)acrylates.

The urethane (meth)acrylate can be obtained, for example, by the reaction of a polyol and an organic diisocyanate with a hydroxyl (meth)acrylate.

In addition, the preferred epoxy (meth)acrylate is obtained by reacting a trifunctional or higher aromatic epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin, etc. with (meth)acrylic acid (A Base) acrylate; (meth)acrylate obtained by reacting bifunctional or higher aromatic epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin, etc., with polybasic acid and (meth)acrylic acid; And (meth)acrylate obtained by reacting bifunctional or higher aromatic epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin, etc., with phenols and (meth)acrylic acid.

The above-mentioned ionizing radiation-curable compounds can be used singly or in combination of two or more kinds.

When the ionizing radiation curable compound is an ultraviolet curable compound, the ionizing radiation curable composition preferably contains additives such as a photopolymerization initiator or a photopolymerization accelerator.

類等中之1種以上。 Examples of the photopolymerization initiator include: selected from acetophenone, benzophenone, α-hydroxyalkylphenone (α-hydroxyalkylphenone), α-aminoalkylphenone, α-hydroxyketone, and Michele Ketones, benzoin, benzophenone methyl ketal, benzyl benzoate, α-oxime ester, phosphine oxides, 9-oxysulfur

One or more of the categories.

啉基丙烷-1-酮中之1種或複數種。 Among the above-mentioned photopolymerization initiators, bis(2,4,6-trimethylbenzyl)-phenylphosphine oxide, oligo(2-hydroxy-2-methyl-1-[4- (1-methylvinyl)phenyl)acetone, 2-hydroxy-2-methyl-1-phenyl-propane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone and 2-methyl- 1-(4-Methylthienyl)-2-N-

One or more of the hydroxypropan-1-ones.

The photopolymerization initiator is not limited to the above-mentioned compound, and may be any one as long as it has the ability to initiate polymerization by ultraviolet rays. These photopolymerization initiators can be used individually by 1 type or in combination of 2 or more types.

The content of the photopolymerization initiator in the ionizing radiation curable resin composition is not particularly limited. Preferably, it is used within the range of 1-20 parts by mass relative to 100 parts by mass of the total amount of the ultraviolet curable compound. In the case of using a plurality of types, it is preferable to use each within the above-mentioned range.

The photopolymerization initiator preferably has a melting point of 100°C or higher. By setting the melting point of the photopolymerization initiator to 100°C or higher, the photopolymerization initiator remaining due to the heat during the formation of the transparent conductive film of the touch panel or the heat of the crystallization step is sublimated, thereby preventing damage to the transparent conductive film The low resistance.

In addition, the photopolymerization accelerator can reduce the polymerization inhibition caused by air during curing and accelerate the curing speed. For example, it can be selected from the group consisting of isoamyl p-dimethylamino benzoate and ethyl p-dimethylamino benzoate. One or more of esters.

In addition, the coating liquid for forming an uneven layer preferably contains a leveling agent. As the leveling agent, for example, a fluorine-based leveling agent, a silicone-based leveling agent, a fluorine-based polysiloxane copolymer-based leveling agent, and the like can be cited. Among them, from the viewpoint of making the uneven layer easily satisfy the above-mentioned conditions (A1) and (A2), a silicone-based leveling agent can be preferably used. Moreover, compared with the reactive ones, the non-reactive ones tend to have better operability of the touch panel.

The addition amount of the leveling agent is preferably 0.01 to 5.0% by weight with respect to the total solid content of the uneven layer.

The unevenness of the optical sheet is preferably formed by anti-fouling treatment. By implementing the antifouling treatment, it is possible to prevent stains from remaining in the unevenness and impairing the surface shape of the embodiment A. In addition, antifouling treatment with fluorine-based mold release agents or silicone-based mold release agents is preferable in that it imparts sliding properties to irregularities, easily meets the condition (A1), and can make the touch feel better. .

Examples of anti-fouling treatment methods include: a method of making the uneven layer contain a fluorine-based mold release agent, a silicone-based mold release agent, and other mold release agents; The means. When the uneven layer contains a release agent, the content of the release agent is preferably set to that of the uneven layer 0.5~5.0% by mass of all solid components.

(Transparent substrate)

As the transparent substrate used in the optical sheet, one having light transmittance, smoothness, heat resistance, and excellent mechanical strength is preferred. Examples of such transparent substrates include: polyester, triacetyl cellulose (TAC), cellulose diacetate, cellulose acetate butyrate, polyamide, polyimide, polyether turbinate, polysulfide, Polypropylene, polymethylpentene, polyvinyl chloride, polyvinyl acetal, polyether ketone, polymethyl methacrylate, polycarbonate, polyurethane and amorphous olefins (Cyclo-Olefin- Polymer: COP) and other plastic films. The transparent substrate can also be formed by laminating two or more plastic films.

Moreover, in addition to the above-mentioned plastic film produced by general methods such as melt extrusion molding (inflation molding method, T-die method) or solution casting method: solution casting, calendaring method: calendaring, etc., it may also be A coating film made of a resin such as an ionizing radiation curable resin composition is formed on a substrate having mold releasability, and the coating film is peeled from the substrate to produce a film.

Among the above, from the viewpoint of mechanical strength or dimensional stability, polyesters (polyethylene terephthalate, polyethylene naphthalate (polyethylene naphthalate )). In addition, COP and polyester are preferable in that they are excellent in weather resistance.

The thickness of the transparent substrate is preferably 5 to 300 μm, more preferably 10 to 200 μm, and still more preferably 20 to 130 μm.

In order to improve adhesion, the surface of the transparent substrate can be treated with corona discharge treatment, oxidation treatment and other physical treatments in advance. In addition, coatings called tackifiers or primers can also be applied in advance.

The transparent substrate preferably has a retardation value of more than 0 nm and less than 3,000 nm, more preferably more than 2.0 nm and less than 2,000 nm. The retardation value is set to a value at a wavelength of 550 nm.

The retardation value of the transparent substrate is based on the following formula, and by the direction of the maximum refractive index in the transparent substrate, that is, the refractive index n _{x in} the direction of the late axis, the in-plane of the transparent substrate and the direction of the late axis _{The orthogonal direction is represented by the refractive index n y in} the direction of the advancing axis and the thickness d of the transparent substrate, and is referred to as the so-called "in-plane retardation".

Delay value (Re)=(n _x -n _y )×d

The above-mentioned delay value can be measured by, for example, the product names "KOBRA-WR" and "PAM-UHR100" manufactured by Oji Measuring Instruments Co., Ltd.

Generally, when a transparent substrate with a small retardation value is used, the color unevenness of the gradual color generated by the light passing through the transparent substrate is observed (for example, through polarized sunglasses, the transparent substrate with a specific retardation value is recognized Observed during the light of the substrate). However, since the optical sheet used in the touch panel of Embodiment A satisfies the condition (A2), even if a transparent substrate with a small retardation value is used, the color unevenness of the gradation color can be difficult to notice.

Furthermore, even if the retardation value is reduced, the unevenness of the gradation color can be made less noticeable because of the fact that the thickness of the transparent substrate can be made thinner. That is, with regard to a transparent substrate (for example, a polyester film as a general-purpose substrate) that generates retardation, generally, the retardation value is increased by performing uniaxial stretching to increase the thickness of the substrate, thereby suppressing the generation The color of the gradient is uneven. However, regarding the optical sheet used in the touch panel of Embodiment A, even if the thickness of the transparent substrate (for example, polyester film as a general-purpose substrate) is made thinner, the gradation color may be uneven. It's hard to notice.

Furthermore, even if the retardation value is reduced, the uneven color of the gradation color can be difficult to be noticeable. The situation is related to the following conditions, and it can be used normally because the color unevenness of the gradation color is easy to occur, such as outside the choice. Plastic film (polyimide film, polyaramide film). The polyimide film and the polyaramide film are preferable in that they are excellent in flexibility resistance.

In recent years, there has been a tendency for the color gamut of display devices to expand. Display elements with a wide color gamut are in various colors (R, The spectral spectra of G and B) each have a steep shape. For this type of display element, there is a tendency that the color unevenness of the gradation specific to the retardation value is particularly noticeable. Regarding the optical sheet used in the touch panel of the embodiment A, it is preferable in that even for a display element with a wide color gamut, the uneven color of the gradation color can be made less noticeable.

The optical sheet may have functional layers such as an anti-reflection layer, an anti-fouling layer, and an anti-static layer on the surface of the unevenness and/or on the opposite side of the unevenness. In addition, in the case of a structure having a concavo-convex layer on a transparent substrate, in addition to the above-mentioned portions, a functional layer may be provided between the transparent substrate and the concavo-convex layer.

Furthermore, when other functional layers are laminated on the uneven layer, the unevenness on the outermost surface meets the scope of this application. The concavity and convexity may be a single layer or multiple layers as long as the outermost surface is within the scope of the present application.

The touch panel of Embodiment A provides outdoor anti-glare properties by the uneven shape of the above-mentioned optical sheet, and is excellent in operability. In addition, it is also possible to suppress the decrease in resolution.

Therefore, the touch panel of Embodiment A is preferably installed on the exit surface side of the display element of a smartphone or tablet (multifunctional mobile terminal) carried when a car display device or a train is moving.

[Display device]

The display device of Embodiment A is a display device having unevenness on the outermost surface of the exit surface side of the display element, and the unevenness satisfies the above-mentioned conditions (A1) and (A2).

The display device of the embodiment A can use the same optical sheet used in the touch panel of the above-mentioned embodiment A as a member having unevenness on the outermost surface.

As the display element, a liquid crystal display element, an in-cell touch panel liquid crystal display element, an EL display element, a plasma display element, etc. can be mentioned. Furthermore, the liquid crystal display element is The back of the crystal element has a backlight device.

The in-cell touch panel liquid crystal element is a liquid crystal element that is formed by sandwiching liquid crystal between two glass substrates and has a resistive film type, an electrostatic capacitance type, an optical type, and other touch panel functions. Furthermore, as the display method of the liquid crystal of the in-cell touch panel liquid crystal element, IPS method, VA method, multi-domain method, OCB method, STN method, TSTN method, etc. can be cited. The in-cell touch panel liquid crystal element is described in, for example, Japanese Patent Application Publication No. 2011-76602 and Japanese Patent Application Publication No. 2011-222009.

The optical sheet can be arranged on the exit surface side of the display element in the following order, for example.

(a) Display element/Surface protection board/Optical sheet

(b) Display element/optical sheet

(c) Touch panel with display element/optical sheet on the top

In the cases of (a) and (b), the display device can be provided with outdoor anti-glare properties by arranging the concave and convex of the optical sheet toward the opposite side of the display element. In addition, the reduction of the resolution of the display element can be suppressed, and the scars generated on the surface or the display element can be made difficult to see.

In the case of (c), the display device is a display device with a touch panel provided with a touch panel with an optical sheet on the uppermost part on the exit surface side of the display element. In this case, a display device with excellent outdoor anti-glare properties, high resolution, and operability of the touch panel can be made.

Therefore, the display device of Embodiment A is preferably used as an in-vehicle display device, a smart phone or a tablet (multifunctional mobile terminal) carried when traveling on a train, etc.

As described above, regarding the optical sheet used in the display device of Embodiment A, even for a display element with a wide color gamut, the color unevenness of the gradation color can be made difficult to notice. As a standard for expressing the color gamut, one can include: "ITU-R Advice BT.2020 (hereinafter referred to as "BT.2020")" Wait. ITU-R is the abbreviation of "International Telecommunication Union-Radiocommunication Sector". ITU-R advises that BT.2020 is an international standard for the color gamut of high-definition television.

Regarding the display device of Embodiment A, even for display elements with a coverage rate of 60% or more based on BT.2020 of the CIE-xy chromaticity diagram represented by the following formula, the uneven color of the gradation can be made difficult to attract Attention.

<Expression of the coverage of BT.2020> [The area of the CIE-xy chromaticity diagram of the display device that overlaps with the area of the CIE-xy chromaticity diagram of BT.2020/CIE-xy color of BT.2020 The area of the degree map''×100(%)

Furthermore, the "CIE-xy chromaticity diagram area" necessary to calculate the coverage of BT.2020 is to measure the CIE- with red (R) display, green (G) display, and blue (B) display. The x and y values of the Yxy color system can be obtained from the "red (R) vertex coordinates", "green (G) vertex coordinates" and "blue (B) vertex coordinates" obtained from the measurement results "Calculated. The x value and y value of the CIE-Yxy color system can be measured using, for example, a spectroradiometer CS-2000 manufactured by Konica Minolta.

Examples of display elements with a wide color gamut include: three-color independent organic EL display device (among them, three-color independent organic EL device with a microcavity structure), a liquid crystal display element with quantum dots used as a backlight, and a backlight The device uses three-wavelength white LED (near ultraviolet LED, a combination of blue phosphor, green phosphor, and red phosphor) liquid crystal display elements, etc.

[Optical Sheet]

The optical sheet of Embodiment A has unevenness on one side, and the unevenness satisfies the above-mentioned condition (A1) and (A2). Furthermore, in the optical sheet of Embodiment A, when other functional layers are laminated on the above-mentioned unevenness, the unevenness on the outermost surface satisfies the scope of the present application. The concavity and convexity may be a single layer or multiple layers as long as the outermost surface is within the scope of the present application.

As the optical sheet of Embodiment A, the same optical sheet used for the touch panel of the above-mentioned Embodiment A can be mentioned.

When the optical sheet of Embodiment A is used for a touch panel, the optical sheet is installed in such a way that the surface with unevenness becomes the surface on the operator side of the touch panel.

In order to satisfy the above-mentioned conditions (A1) and (A2), the optical sheet of Embodiment A is placed on the uppermost part of the touch panel, thereby imparting outdoor anti-glare properties to the touch panel and making the touch panel The operability becomes excellent.

Therefore, the optical sheet of Embodiment A can be preferably used on the surface of a display device for a vehicle, and the surface of a smartphone or tablet (multifunctional mobile terminal) carried when moving on a train, etc.

[Screening method of optical film]

The screening method of the optical sheet of the embodiment A is to select an optical sheet having unevenness on one side and the unevenness satisfying the above-mentioned conditions (A1) and (A2) as the optical sheet located on the uppermost part of the touch panel.

In the optical sheet screening method of Embodiment A, even if the operability test of the optical sheet is not performed, it is possible to screen optical sheets with good operability, outdoor anti-glare properties and high resolution, and can be performed efficiently Product design and quality management of optical films.

Regarding the judging conditions for screening the optical sheets of the touch panel, the above-mentioned conditions (A1) and (A2) are required. The determination condition of the condition (A1) preferably satisfies 0.80≦μs ₂₀ /μs ₁₀ ≦1.65, and more preferably satisfies 0.85≦μs ₂₀ /μs ₁₀ ≦1.55. In addition, the determination condition of the condition (A2) preferably satisfies 0.15 μm≦Ra _2.5 ≦0.60 μm, and more preferably satisfies 0.25 μm≦Ra _2.5 ≦0.55 μm.

Regarding the selection method of the optical sheet of the touch panel, it is better to set one or more of the following conditions (A3) to (A5) as new from the viewpoints of touch during operation and outdoor anti-glare properties Add the judgment condition, and it is better to set all (A3)~(A5) as the newly added judgment condition.

5.7≦Rz _2.5 /Ra _2.5 (A3)

S _2.5 ≦70μm (A4)

0.10μm≦Rz _{2.5 -Rz 0.8} ≦1.50μm (A5)

The judgment conditions of the conditions (A3) to (A5) are preferably the preferable numerical range of the optical sheet of the above-mentioned embodiment A.

Furthermore, it is preferable to set other parameters as newly added judgment conditions.

<Embodiment B>

[Touch Panel]

The touch panel of Embodiment B has unevenness on the surface of the operator side, and the unevenness satisfies the following conditions (B1) and (B2).

Condition (B1): A sapphire squeegee with a tip radius of 0.3mm is vertically in contact with the above-mentioned unevenness, a vertical load Tg is applied to the above-mentioned squeegee, and at the same time, the squeegee is made to perform a single pass length of 10mm at a speed of 5mm/sec. Go back and forth once, and measure the coefficient of static friction μs and the coefficient of dynamic friction μk acting on the above-mentioned scraper at this time. In the graph drawn with the ratio of the static friction coefficient μs to the dynamic friction coefficient μk (μs/μk) as the vertical axis and the vertical load Tg as the horizontal axis, the curve in the range of the vertical load 100~1000g is used as When the least square method is approximated by a straight line, the slope of the straight line is negative.

_{Condition (B2): The arithmetic average roughness (Ra 2.5} ) of JIS B0601:1994 when the cut-off value of the above-mentioned unevenness is 2.5 mm is 0.10 μm or more and 0.60 μm or less.

In Embodiment B, the so-called "surface on the operator's side" refers to the surface that the operator actually touches and operates when operating the touch panel.

Examples of touch panels include electrostatic capacitive touch panels, resistive film touch panels, optical touch panels, ultrasonic touch panels, electromagnetic induction touch panels, and the like. These touch panels may have a transparent substrate such as a glass substrate and a plastic film substrate, and the transparent substrate may have unevenness useful for imparting anti-glare properties. The touch panel of Embodiment B has, for example, the following optical sheet on the uppermost part as such a member having irregularities on a transparent substrate.

As shown in FIG. 1, the resistive film type touch panel 1 is connected to a circuit not shown in the figure so that the conductive film 12 of the next pair of transparent substrates 11 on the conductive film 12 faces each other and is arranged with spacers 13 interposed therebetween. The basic constituents of becoming. In the case of a resistive film type touch panel, in Embodiment B, the following optical sheet is used as the upper transparent substrate. By using the following optical sheet as the upper transparent substrate of the resistive film type touch panel as described above, the concave-convex shape of the optical sheet can be used to impart outdoor anti-glare properties to the touch panel and change the operability of the touch panel. It's excellent. In addition, the reduction in resolution can be suppressed.

Furthermore, the above-mentioned optical sheet can also be used as the lower transparent substrate together with the upper transparent substrate.

The capacitive touch panel includes a surface type and a projection type, and the projection type is often used. The projection type electrostatic capacitive touch panel is a basic structure in which an X-axis electrode and a Y-axis electrode orthogonal to the X-axis electrode are arranged with an insulator interposed between a circuit and a circuit. If the basic structure is explained more specifically, it can be exemplified: the X-axis electrode and the Y-axis electrode are formed on different sides of a transparent substrate; the X-axis electrode, the insulator layer, and the The state of the Y-axis electrode; as shown in Figure 2, the X-axis electrode 22 is formed on a transparent substrate 21, and The Y-axis electrode 23 is formed on the other transparent substrate 21, and the layer is laminated via the adhesive layer 24 and the like. In addition, it can be exemplified in these basic patterns and then laminated with another transparent substrate.

In the case of an electrostatic capacitive touch panel, in Embodiment B, the following optical sheet is used as the uppermost transparent substrate. By using the following optical sheet as the uppermost transparent substrate of an electrostatic capacitive touch panel as described above, the concave-convex shape of the optical sheet can be used to impart outdoor anti-glare properties to the touch panel and make the touch panel more effective. The operability becomes excellent. In addition, the reduction in resolution can be suppressed.

The above-mentioned touch panel is used, for example, as an in-cell type touch panel disposed on a display element.

(Optical Sheet)

The optical sheet of Embodiment B has unevenness on one surface, and the unevenness satisfies the above-mentioned conditions (B1) and (B2).

Fig. 4 shows the unevenness of the optical sheet of Embodiment B. When the ratio of static friction coefficient μs to dynamic friction coefficient μk (μs/μk) is set on the vertical axis, and the vertical load Tg is set on the horizontal axis, the plot is vertical. The curve of the load range of 100~1000g is approximated to a straight line graph obtained by the least square method. As shown in FIG. 4, the optical sheet of Embodiment B has a negative slope of the above-mentioned approximate linear straight line, and as the load (vertical load) applied to the unevenness of the optical sheet becomes larger, the ratio (μs/μk) becomes smaller . This means that the larger the vertical load becomes, the more easily the unevenness of the optical sheet becomes deformed, and the less the influence of the unevenness becomes.

When performing operations that change the direction of the finger on the optical sheet, such as writing characters or drawing graphics, most of them stop for a moment and then start again (for example, when the direction of the finger is changed, the movement of the finger is usually stopped for a moment; also, move and place The movement of the finger will also stop for a moment when the finger is positioned). It’s easy to be The effect produced by the difference between the static friction coefficient μs and the dynamic friction coefficient μk.

When the vertical load is small, if the ratio (μs/μk) is too small, the finger will easily slide on the optical sheet and it will become difficult to change the direction. In addition, when the vertical load is large, if the ratio (μs/μk) is too large, when the finger is switched on the optical sheet, the finger receives a high load and it becomes difficult to switch the direction.

Therefore, in order to easily change the direction of the finger on the optical sheet, it is required that when the vertical load is small, the finger will not slide excessively to obtain a moderate sense of impedance, and the load applied to the finger will be suppressed as the vertical load becomes larger. .

Regarding the optical sheet of Embodiment B, by satisfying the above-mentioned condition (B1), complicated operations such as changing the direction of a finger on the optical sheet can be performed well.

Furthermore, as a situation where the load is different, for example, the situation in which the terminal is operated while standing in the tram (the operation load is usually light at this time); the operation is carried out while the terminal is placed on a table and fixed with one hand. Condition (the operating load at this time is usually heavier). That is, by satisfying the condition (B1), complicated operations such as direction conversion can be performed well under the conditions of different postures during operation and different operation loads.

Furthermore, in the embodiment B, the coefficient of dynamic friction μk means the average value of the coefficient of dynamic friction over the entire measurement time. In addition, the static friction coefficient μs is assumed to be the peak value of the initial friction force above the dynamic friction coefficient with the elapse of the measurement time from the friction force 0.

The coefficient of static friction μs and the coefficient of dynamic friction μk can be measured by a friction and abrasion tester (manufactured by Shinto Science Co., Ltd., HEIDON NHS2000).

When the vertical load is small, for example, the ratio (μs/μk) when the load is 50~150g, from the viewpoint of obtaining a moderate sense of impedance without excessive sliding, it is preferably 1.58 ~2.50, more preferably 1.70~2.20. In addition, when the vertical load is large, for example, the ratio (μs/μk) when the load is 900 to 1100 g, from the viewpoint of suppressing excessive load, it is preferably 1.00 to 1.50, and more preferably 1.10 to 1.40.

Furthermore, in the condition (B1), the slope of the approximate linear straight line is preferably -10.0×10 ^-4 to -4.5×10 ^-4 , more preferably -8.5×10 ^-4 to -6.0×10 ^-4 . If it is in the above range, the operability can be improved.

In addition, in the condition (B2), the cut-off value is 2.5 mm. The cut-off value is a value indicating the degree to which the cut-off of the cross-sectional profile formed by the free roughness component (high-frequency component) and the waviness component (low-frequency component) cuts off the waviness component. In other words, the cutoff value represents the fineness of the filter that cuts the waviness component (low frequency component) from the profile curve. If the cutoff value is large, the filter is sparse, so the large waviness component of the waviness component is truncated, but the small waviness component is not truncated. On the other hand, if the cutoff value is small, the filter is denser, so the waviness component is basically cut off. In JIS B0633 referred to in JIS B0601, the cut-off value (reference length) is set to 0.8mm when the arithmetic average roughness Ra is 0.1~2μm. Therefore, according to JIS B0633, in the case of Ra in the above condition (B2), the standard is to set the cut-off value (reference length) to 0.8 mm.

However, the touch, outdoor anti-glare properties and resolution during operation are not only affected by roughness components (high frequency components), but also by waviness components (low frequency components). Therefore, the cutoff value (reference length When) is set to 0.8mm, the waviness component (low frequency component) of the roughness curve is cut to a greater degree, and it cannot be evaluated compared to outdoor anti-glare and resolution, which is more susceptible to low frequency components. The fear of the touch of time. Therefore, in the embodiment B, the cut-off value of the condition (B2) is set to 2.5 mm.

The condition (B2) is that the arithmetic mean roughness Ra _2.5 is 0.10 μm or more and 0.60 μm or less. If Ra _{2.5 is} less than 0.10 μm, light scattering is insufficient and anti-glare properties are reduced. In addition, the contact area between the finger and the surface of the optical sheet increases and the tactile feel (slidability) deteriorates. If Ra _2.5 exceeds 0.60 μm, sliding properties during operation will be impaired, and contrast and resolution will decrease. In terms of touch during operation, outdoor anti-glare properties, and resolution, condition (B2) preferably satisfies 0.15μm≦Ra _2.5 ≦0.60μm, more preferably satisfies 0.25μm≦Ra _2.5 ≦0.55μm, and then Preferably, it satisfies 0.30 _{μm≦Ra 2.5} ≦0.50 μm.

In addition, if the arithmetic average roughness Ra _2.5 is 0.10 μm or more, the color unevenness of the gradation peculiar to the retardation value of the transparent substrate can be made less noticeable. The so-called color unevenness of the gradual color peculiar to the retardation value is the color unevenness of the rainbow pattern produced by the light passing through the transparent substrate with the retardation value. Such color unevenness is recognized through the polarizing plate through polarized sunglasses, for example. , A transparent substrate with a specific retardation value is observed during light.

Furthermore, by satisfying the following condition (B3) in addition to the above condition (B2), it becomes easier to satisfy the above condition (B1). In particular, when Ra _{2.5 is} preferably 0.25 μm or more, and more preferably 0.30 μm or more, for example, a display element with a wide color gamut can make the color unevenness of the gradation color more difficult to notice.

_{In addition, the above-mentioned unevenness preferably has a ten-point average roughness (Rz 0.8} ) of JIS B0601: 1994 when the cut-off value is 0.8 mm, and a ten-point average roughness of JIS B0601: 1994 when the cut-off value is 2.5 mm. (Rz _2.5 ) Meet the following condition (B3).

Rz _0.8 /(Rz _2.5 -Rz _0.8 )≦3.2 (B3)

When the cut-off value is set to 0.8mm, compared with the case where the cut-off value is set to 2.5mm, the low-frequency component of the roughness curve is cut to a greater extent. That is, _{the value of Rz 0.8} can be regarded as the high frequency component in the unevenness of the optical sheet, and the value of (Rz _{2.5- Rz 0.8} ) can be regarded as the low frequency component in the unevenness of the optical sheet. Therefore, the condition (B3) "Rz _0.8 /(Rz _{2.5- Rz 0.8} )" can be regarded as the ratio of the high-frequency components of the bumps to the low-frequency components.

In the condition (B3), "Rz _0.8 /(Rz _2.5 -Rz _0.8 ) is 3.2 or less" means that the high frequency components will not be excessive and have a certain amount of low frequency components. Therefore, when force is applied to the unevenness, the high frequency components Concavity and convexity are easy to maintain. On the other hand, the concavity and convexity of the low-frequency component becomes easy to deform, and it becomes easier to satisfy the above-mentioned condition (B1).

Furthermore, increasing the absolute amount of concavities and convexities also makes it easier to satisfy the condition (B1), but in this case, the condition (B2) cannot be satisfied. In other words, it is preferable to satisfy the condition (B1) by satisfying the condition (B3) within the range of the unevenness satisfying the condition (B2).

The condition (B3) preferably satisfies Rz _0.8 /(Rz _2.5 -Rz _0.8 )≦3.0, and more preferably satisfies Rz _0.8 /(Rz _2.5 -Rz _0.8 )≦2.9. Satisfying Rz _0.8 /(Rz _2.5 -Rz _0.8 )≦3.0 is also related to the following situation: For example, for display elements with a wide color gamut, the color unevenness specific to the retardation value of the transparent substrate can be made more difficult to attract Attention. In addition, as the lower _{limit of Rz 0.8} /(Rz _{2.5 -Rz 0.8} ), it is preferably 1.0 or more, more preferably 2.0 or more, and still more preferably 2.5 or more.

Furthermore, it is preferable that the above-mentioned unevenness is such that the above-mentioned Rz _2.5 and the above-mentioned Ra _2.5 satisfy the following condition (B4).

5.7≦Rz _2.5 /Ra _2.5 (B4)

The so-called arithmetic average roughness Ra is the value obtained by integrating the absolute values of the elevations of the peaks and valleys of the roughness curve of the evaluation length and dividing by the evaluation length, in the form of an equal elevation. On the other hand, the so-called ten-point average roughness Rz is to divide the roughness curve of the evaluation length N times the sampling length equal to the cut-off value into N equal parts, and find the first to fifth heights of each interval The average elevation of the top of the peak and the average elevation of the bottom of the valley from the 1st to the 5th depth The arithmetic average of N Rz's at intervals of Rz'. That is, Ra is the average value of the elevation of the entire roughness curve, while Rz is the average value of the elevations at the 5 higher and 5 lower points in the roughness curve. Therefore, when the roughness curve does not have randomness, Ra and Rz are approximately the same, but when the roughness curve has randomness, Rz becomes larger than Ra. Therefore, Rz/Ra becomes an index indicating the randomness of the roughness curve.

If Rz _2.5 /Ra _2.5 is 5.7 or more, the randomness of the roughness curve is improved, the contact area between the finger and the surface of the optical sheet is reduced, and the tactility becomes better. In addition, by increasing the randomness of the roughness curve, there is a tendency that for display elements with a wide color gamut, the color unevenness of the gradual color can be made more difficult to notice. Furthermore, from the viewpoints of tactile feel (slidability) and resolution, it is preferable that the roughness does not cause excessive randomness.

The condition (B4) is more preferably 6.0≦Rz _2.5 /Ra _2.5 ≦10.0, more preferably 6.5≦Rz _2.5 /Ra _2.5 ≦9.5, and still more preferably 7.0≦Rz _2.5 /Ra _2.5 ≦9.0.

_{The Rz 2.5 of} the concavity and convexity is preferably 0.50 to 4.30 μm, more preferably 1.00 to 4.00 μm, and still more preferably 2.00 to 4.00 μm. If Rz _2.5 is 0.50 μm or more, it becomes easier to satisfy the above-mentioned condition (B1), and outdoor anti-glare properties can be imparted to the touch panel, and the tactile feeling (slidability) can be improved. If Rz _2.5 is 4.30μm or less, the generation of glare can be suppressed, and the sliding property during operation will not be impaired.

Furthermore, if Rz _2.5 is 2.00 μm or more, for example, for a display element with a wide color gamut, the color unevenness of the gradation peculiar to the retardation value of the transparent substrate can be made more difficult to notice.

Moreover, it is preferable that the above-mentioned unevenness|corrugation should satisfy the following condition (B5) by the _{average interval (S 2.5} ) of the local peak top of JIS B0601:1994 when the cut-off value is set to 2.5 mm.

S _2.5 ≦70μm (B5)

If the average distance between local peak tops (S _2.5 ) is 70 μm or less, the contact area between the finger and the surface of the optical sheet is reduced, and the touch (slidability) can be improved.

The condition (B5) preferably satisfies S _2.5 ≦65 μm, more preferably satisfies 20 μm≦S _2.5 ≦60 μm, and more preferably satisfies 30 μm≦S _2.5 ≦55 μm.

_{Furthermore, it is preferable that the maximum height (Ry 2.5} ) of JIS B0601:1994 when the cutoff value is 2.5 mm for the above-mentioned concavities and convexities satisfies the following conditions.

0.60μm≦Ry _2.5 ≦5.0μm

If Ry _2.5 is 5.0μm or less, it can prevent finger jam during operation, and make the operability better. In addition, the generation of glare can be prevented more. If Ry _2.5 is 0.60 μm or more, outdoor anti-glare properties can be imparted.

Moreover, from the viewpoint of easily satisfying the following conditions (B6) and (B7), Ry _2.5 is more preferably 1.0 μm or more and 4.7 μm or less, and still more preferably 1.2 μm or more and 4.5 μm or less.

Furthermore, it is preferable that the above-mentioned concavities and convexities are such that the above-mentioned (Ry _2.5 ) and the above-mentioned Rz _2.5 satisfy the following condition (B6).

Ry _2.5 /Rz _2.5 ≦1.5 (B6)

If Ry _2.5 /Rz _2.5 is 1.5 or less, it can prevent finger jam during operation and make the operability better. In addition, the generation of glare can be more prevented, and outdoor anti-glare properties can be easily imparted.

Ry _2.5 /Rz _2.5 is more preferably 1.10 or more and 1.40 or less, and still more preferably 1.18 or more and 1.37 or less.

_{Furthermore, it is preferable that the average inclination angle (θa 2.5} ) of the unevenness when the cutoff value is set to 2.5 mm for the unevenness described above satisfies the following conditions.

1.0°≦θa _2.5 ≦5.5°

If θa _2.5 is 1.0° or more, outdoor anti-glare properties can be imparted to the touch panel, and operability can be improved. If θa _2.5 is 5.5° or less, the decrease in contrast can be suppressed, and the outdoor anti-glare property and contrast can be balanced. θa _2.5 preferably satisfies 1.3°≦θa _2.5 ≦4.5°, and further preferably satisfies 2.0°≦θa _2.5 ≦4.0°. In addition, if θa _2.5 is 1.3° or more, the color unevenness of the gradation peculiar to the retardation value of the transparent substrate can be made difficult to notice. Furthermore, if it is preferably 1.5° or more, and more preferably 2.0° or more, for example, a display element with a wide color gamut can make the color unevenness of the gradation color more difficult to notice.

Here, the "average inclination angle θa" is the value defined in the operation manual (1995.07.20 revision) of the surface roughness measuring instrument (trade name: SE-3400) manufactured by Kosaka Research Laboratory, as shown in Figure 3. may be present in the reference length L by the height of the convex portion and _{(h 1 + h 2 + h} 3 + ‧‧‧ + h n) of the arctangent _{^{θa = tan -1 {(h 1}} + h 2 + h 3 +‧‧‧+h _n )/L}.

In addition, θa can be calculated according to the following formula (A).

[In formula (A), "L" represents the reference length, and "dy/dx" represents the slope of each unit interval of the roughness curve].

Furthermore, the so-called "reference length" means "cut-off value". That is, when the cutoff value is 0.8 mm, the reference length is 0.8 mm. Also, the so-called unit measurement interval is the interval obtained by dividing the cut-off value by the number of samples. The sampling number is set to 1500.

Furthermore, it is preferable that the unevenness described above (θa _2.5 ) and the above Ry _2.5 /Rz _2.5 satisfy the following condition (B7).

0.8≦θa _2.5 /(Ry _2.5 /Rz _2.5 )≦5.0 (B7)

If θa _2.5 /(Ry _2.5 /Rz _2.5 ) is within the above-mentioned range, it becomes unevenness with moderate randomness, and can provide anti-glare properties, resolution, touch (slidability) during operation, and The color unevenness of the gradation that is unique to the retardation value of the transparent substrate is difficult to notice and the balance becomes good.

θa _2.5 /(Ry _2.5 /Rz _2.5 ) is more preferably 1.0 or more and 4.5 or less. Even in the case of a display element with a wide color gamut, the color unevenness of the gradation color can be made difficult to notice, so it is more preferably 1.2 or more and 4.0 or less.

_{Furthermore, it is preferable that the above-mentioned unevenness|corrugation is the average interval (Sm 2.5} ) of unevenness|corrugation of JIS B0601: 1994 when the cut-off value is 2.5 mm, and satisfy|fills the following conditions.

Sm _2.5 ≦160μm

If Sm _2.5 is 160 μm or less, the contact area between the finger and the surface of the optical sheet is reduced, and the touch (slidability) can be improved. Sm _{2.5 is more} preferably 150 μm or less, and still more preferably 145 μm or less. In addition, the lower limit is preferably 30 μm or more, more preferably 50 μm or more, and still more preferably 100 μm or more.

Furthermore, the _{smaller the Sm 2.5} , even for high-definition displays, the more glare can be suppressed.

As a method of forming the above-mentioned unevenness, for example, (x1) physical or chemical treatments such as embossing, sandblasting, and etching, (x2) molding with a mold, (x3) formation of an uneven layer by coating, and the like. Among these methods, from the viewpoint of the reproducibility of the concave-convex shape, (x2) molding using a mold is preferable, and from the viewpoint of productivity and a variety of products, it is preferable to (x3) forming concave-convex by coating Floor.

Molding using a mold can be formed by making a mold composed of a shape complementary to the unevenness, flowing the uneven-forming material into the mold, and then taking it out of the mold. Here, if the material constituting the concavities and convexities is used as the material, the material is poured into the mold and the transparent substrate is superimposed, and the concavities and convexities are taken out from the mold together with the transparent substrate, then the transparent substrate can be obtained. Convex optical sheet. In addition, if the material constituting the transparent substrate is poured into the mold and then taken out from the mold, an optical sheet composed of a single layer of the transparent substrate and having unevenness on the surface of the transparent substrate can be obtained.

When a curable resin composition (thermosetting resin composition or ionizing radiation curable resin composition) is used as the material to be poured into the mold, it is preferable to harden the curable resin composition before taking it out of the mold.

In terms of excellent reproducibility of the uneven shape, it is preferable to form the unevenness with a mold.

The concave-convex layer formed by coating can be formed by applying a coating solution for forming a concave-convex layer containing resin components and particles on a transparent substrate by a well-known coating method such as gravure coating and bar coating. It can be formed by drying and hardening as needed. In order for the uneven layer to satisfy the above-mentioned conditions (B1) and (B2), it is preferable to set the film thickness of the uneven layer, the content of particles, and the average particle diameter of the particles within the following ranges.

The film thickness of the uneven layer is preferably 1.0 to 10 μm, more preferably 1.5 to 5 μm, and still more preferably 1.8 to 4 μm. The film thickness of the concave-convex layer can be measured at 20 locations based on the cross-sectional image taken by a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM), and the average value of the 20 locations And figure it out. The acceleration voltage of TEM or STEM is preferably set to 1 to 5 kV, and the magnification is preferably set to 1000 to 10,000 times.

Any of organic particles and inorganic particles can be used as the particles as long as they can form irregularities. Examples of organic particles include: polymethylmethacrylate, polyacrylic-styrene copolymer, melamine resin, polycarbonate, polystyrene, polyvinyl chloride, benzoguanamine-melamine-formaldehyde condensate, polysilicon Particles composed of oxygen, fluorine-based resin, polyester-based resin, etc. Examples of inorganic particles include particles composed of silica, alumina, zirconia, and titanium oxide. Among these particles, from the viewpoint of ease of dispersion control, a light-transmitting organic Particles, or silica particles.

The above-mentioned particles can be used singly or in combination of two or more different in material or particle size.

In addition, the particles are preferably aggregates. When the concavo-convex layer contains agglomerates of particles, the concavity and convexity of the high-frequency component is easily maintained when force is applied to the concavo-convex layer. On the other hand, the concavity and convexity of the low-frequency component becomes easy to deform, and it becomes easier to satisfy the above conditions ( B1).

In addition, in order to make the color unevenness of the gradation color less noticeable even in the case of a display element with a wide color gamut, the particles are preferably amorphous particles having a particle size above the wavelength of visible light. Since the uneven layer contains irregular particles, the uneven color of the gradation can be suppressed.

The content of the particles is preferably 4-25% by mass, more preferably 5-20% by mass, and still more preferably 5-15% by mass of the total solid components forming the uneven layer.

The average particle size of the particles in the uneven layer is different depending on the thickness of the uneven layer, so it cannot be generalized, but from the viewpoint of easily satisfying the above conditions (B1) and (B2), it is preferably 1.0~10.0μm, more It is preferably 1.0 to 6.0 μm, and more preferably 1.0 to 5.0 μm. In the case of agglomeration of particles, the average particle diameter of the agglomerated particles preferably satisfies the above-mentioned range.

The average particle size of the particles can be calculated by the following operations (y1) ~ (y3).

(y1) Select the largest particle in the observation frame from the cross-sectional images taken by the transmission electron microscope (TEM) or the scanning transmission electron microscope (STEM). The acceleration voltage of TEM or STEM is preferably set to 1-30 kV, and the magnification is preferably set to 5000 to 300,000 times.

(y2) Select the particles with the largest diameter from the observation image, and calculate the particle size of each particle. The particle size is measured in the form of the distance between the straight lines, and the distance between the straight lines is any two parallel lines. When a straight line clamps the cross section of the particle, the distance between the two straight lines becomes the distance between the straight lines in the combination of the largest two straight lines.

(y3) Perform the same operation on the observation image of another screen of the same sample, and set the value obtained from the number average of the total 20 particle diameters as the average particle diameter of the particles.

Furthermore, in the case of agglomerated particles, the largest diameter part of the agglomerated mass is regarded as the particle size.

From the viewpoint that the uneven layer easily satisfies the aforementioned conditions (B1) and (B2), the film thickness of the uneven layer is preferably larger than the average particle diameter of the particles. Furthermore, more specifically, the ratio of [average particle diameter of particles]/[film thickness of uneven layer] is preferably 0.20 to 0.99, and more preferably 0.50 to 0.90.

The particles can also be those with a wide particle size distribution (a single particle with a wide particle size distribution, or a mixed particle formed by mixing two or more particles with different particle size distributions and a wide particle size distribution), from the viewpoint of suppressing glare In general, those with a narrower particle size distribution are preferred.

The resin component of the concavo-convex layer preferably contains a thermosetting resin composition or an ionizing radiation curable resin composition. From the viewpoint of improving mechanical strength, it is more preferable to contain an ionizing radiation curable resin composition. Furthermore, it is more preferable to include an ultraviolet curable resin composition.

The thermosetting resin composition is a composition containing at least a thermosetting resin, and is a resin composition that is cured by heating.

Examples of thermosetting resins include acrylic resins, urethane resins, phenol resins, urea melamine resins, epoxy resins, unsaturated polyester resins, silicone resins, and the like. In the thermosetting resin composition, a curing agent is added to the curable resin as necessary.

The ionizing radiation curable resin composition is a composition containing a compound having an ionizing radiation curable functional group (hereinafter, also referred to as "ionizing radiation curable compound"). As Examples of the ionizing radiation-curable functional group include ethylenically unsaturated bonding groups such as (meth)acryloyl groups, vinyl groups, and allyl groups, epoxy groups, and oxetane groups. The ionizing radiation curable compound is preferably a compound having an ethylenically unsaturated bond group, more preferably a compound having two or more ethylenically unsaturated bond groups, and among them, it is more preferably a compound having two or more ethylenically unsaturated bond groups. Multifunctional (meth)acrylate compound of ethylenically unsaturated bond group. As the polyfunctional (meth)acrylate compound, both monomers and oligomers can be used.

Furthermore, the so-called ionizing radiation refers to electromagnetic waves or charged particle beams that have energy quantum that can polymerize or crosslink molecules. Usually, ultraviolet (UV) or electron beam (EB) can be used. In addition, X-rays, Electromagnetic waves such as gamma rays; charged particle beams such as alpha rays and ion beams.

Among the polyfunctional (meth)acrylate-based compounds, examples of bifunctional (meth)acrylate-based monomers include ethylene glycol di(meth)acrylate and bisphenol A tetraethoxy diacrylate , Bisphenol A tetrapropoxy diacrylate, 1,6-hexanediol diacrylate, dicyclopentenyl di(meth)acrylate, triethylene glycol diacrylate, tetraethylene glycol di( Meth) acrylate, tricyclodecanediyl dimethylene di(meth)acrylate, tris(2-hydroxyethyl) trimer isocyanate di(meth)acrylate, etc.

Examples of (meth)acrylate monomers having trifunctional or higher functions include trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, and neopentylerythritol Tris(meth)acrylate, neopentyl erythritol tetra(meth)acrylate, neopentyl erythritol hexa(meth)acrylate, di-trimethylolpropane tetra(meth)acrylate, dinepentyl Tetraol hexa (meth) acrylate, dineopentyl erythritol penta (meth) acrylate, dineopentaerythritol tetra (meth) acrylate, di-trimethylolpropane tetra (meth) acrylate , Tris (2-hydroxyethyl) trimeric isocyanate, tris (meth) acrylate, etc.

In addition, the above-mentioned (meth)acrylate-based monomers may also be those in which part of the molecular skeleton has been modified. Those modified by ethylene oxide, propylene oxide, caprolactone, isocyanuric acid, alkyl, cyclic alkyl, aromatic, bisphenol, etc. can be used.

In addition, examples of the polyfunctional (meth)acrylate oligomer include urethane (meth)acrylate, epoxy (meth)acrylate, polyester (meth)acrylate, and polyether (meth)acrylate ( Acrylate-based polymers such as meth)acrylate.

The urethane (meth)acrylate can be obtained, for example, by the reaction of a polyol and an organic diisocyanate with a hydroxyl (meth)acrylate.

In addition, the preferred epoxy (meth)acrylate is obtained by reacting a trifunctional or higher aromatic epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin, etc. with (meth)acrylic acid (A Base) acrylate; (meth)acrylate obtained by reacting bifunctional or higher aromatic epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin, etc., with polybasic acid and (meth)acrylic acid; And (meth)acrylate obtained by reacting bifunctional or higher aromatic epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin, etc., with phenols and (meth)acrylic acid.

The above-mentioned ionizing radiation-curable compounds can be used singly or in combination of two or more kinds.

When the ionizing radiation curable compound is an ultraviolet curable compound, the ionizing radiation curable composition preferably contains additives such as a photopolymerization initiator or a photopolymerization accelerator.

類等中之1種以上。 Examples of the photopolymerization initiator include: selected from the group consisting of acetophenone, benzophenone, α-hydroxyalkyl phenone, α-aminoalkyl phenone, α-hydroxy ketone, Michele ketone, benzoin, two Acetophenone methyl ketal, benzyl benzoate, α-acyl oxime ester, acyl phosphine oxides, 9-oxysulfur

One or more of the categories.

啉基丙烷-1-酮中之1種或複數種。 Among the above-mentioned photopolymerization initiators, it is preferable to appropriately select bis(2,4,6-trimethylbenzyl)-phenylphosphine oxide, oligo(2-hydroxy-2-methyl-1-[4 -(1-methylvinyl)phenyl)acetone, 2-hydroxy-2-methyl-1-phenyl-propane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, and 2-methyl Base-1-(4-methylthienyl)-2-N-

One or more of the hydroxypropan-1-ones.

The photopolymerization initiator is not limited to the above-mentioned compound, and may be any one as long as it has the ability to initiate polymerization by ultraviolet rays. These photopolymerization initiators can be used individually by 1 type or in combination of 2 or more types.

The content of the photopolymerization initiator in the ionizing radiation curable resin composition is not particularly limited, and it is preferably used within the range of 1-20 parts by mass relative to 100 parts by mass of the total amount of the ultraviolet curable compound. In the case of using a plurality of types, it is preferable to use each within the above-mentioned range.

The photopolymerization initiator preferably has a melting point of 100°C or higher. By setting the melting point of the photopolymerization initiator to 100°C or higher, the photopolymerization initiator remaining due to the heat during the formation of the transparent conductive film of the touch panel or the heat of the crystallization step is sublimated, thereby preventing damage to the transparent conductive film The low resistance.

In addition, the photopolymerization accelerator can reduce the polymerization inhibition caused by air during curing and accelerate the curing speed. For example, it can be selected from the group consisting of isoamyl p-dimethylamino benzoate and ethyl p-dimethylamino benzoate. One or more of esters.

In addition, the coating liquid for forming an uneven layer preferably contains a leveling agent. As the leveling agent, for example, a fluorine-based leveling agent, a silicone-based leveling agent, a fluorine-based polysiloxane copolymer-based leveling agent, and the like can be cited. Among them, from the viewpoint of making the uneven layer easily satisfy the aforementioned conditions (B1) and (B2), a silicone-based leveling agent can be preferably used. Moreover, compared with the reactive ones, the non-reactive ones tend to have better operability of the touch panel.

The amount of leveling agent added is preferably 0.01 relative to the total solid content of the uneven layer ~5.0% by weight.

The unevenness of the optical sheet is preferably formed by anti-fouling treatment. By implementing the antifouling treatment, it is possible to prevent stains from remaining in the unevenness and impairing the surface shape of the embodiment B. In addition, antifouling treatment with fluorine-based mold release agents or silicone-based mold release agents provides slipperiness to irregularities, easily satisfies the above condition (B1), and can improve the operability. good.

Examples of anti-fouling treatment methods include: a method of making the uneven layer contain a fluorine-based mold release agent, a silicone-based mold release agent, and other mold release agents; The means. In the case where the uneven layer contains a release agent, the content of the release agent is preferably set to 0.5 to 5.0% by mass of the total solid components of the uneven layer.

(Transparent substrate)

As the transparent substrate used in the optical sheet, one having light transmittance, smoothness, heat resistance, and excellent mechanical strength is preferred. Examples of such transparent substrates include: polyester, triacetyl cellulose (TAC), cellulose diacetate, cellulose acetate butyrate, polyamide, polyimide, polyether turbinate, polysulfide, Polypropylene, polymethylpentene, polyvinyl chloride, polyvinyl acetal, polyether ketone, polymethyl methacrylate, polycarbonate, polyurethane and amorphous olefins (Cyclo-Olefin- Polymer: COP) and other plastic films. The transparent substrate can also be formed by laminating two or more plastic films.

Moreover, in addition to the above-mentioned plastic film produced by general methods such as melt extrusion molding (inflation molding method, T-die method) or solution casting method: solution casting, calendaring method: calendaring, etc., it may also be A coating film made of a resin such as an ionizing radiation curable resin composition is formed on a substrate having mold releasability, and the coating film is peeled from the substrate to produce a film.

Among the above, from the viewpoint of mechanical strength or dimensional stability, the polyester (polyethylene terephthalate, polyethylene naphthalate ester). In addition, COP and polyester are preferable in that they are excellent in weather resistance.

The thickness of the transparent substrate is preferably 5 to 300 μm, more preferably 10 to 200 μm, and still more preferably 20 to 130 μm.

In order to improve adhesion, the surface of the transparent substrate can be treated with corona discharge treatment, oxidation treatment and other physical treatments in advance. In addition, coatings called tackifiers or primers can also be applied in advance.

The transparent substrate preferably has a retardation value of more than 0 nm and less than 3,000 nm, more preferably more than 20 nm and less than 2,000 nm. The retardation value is set to a value at a wavelength of 550 nm.

The retardation value of the transparent substrate is based on the following formula, and by the direction of the maximum refractive index in the transparent substrate, that is, the refractive index n _{x in} the direction of the late axis, the in-plane of the transparent substrate and the direction of the late axis _{The orthogonal direction is represented by the refractive index n y in} the direction of the advancing axis and the thickness d of the transparent substrate.

Delay value (Re)=(n _x -n _y )×d

The above-mentioned delay value can be measured by, for example, the product names "KOBRA-WR" and "PAM-UHR100" manufactured by Oji Measuring Instruments Co., Ltd.

Generally, when a transparent substrate with a small retardation value is used, the color unevenness of the gradual color generated by the light passing through the transparent substrate is observed (for example, through polarized sunglasses, the transparent substrate with a specific retardation value is recognized Observed during the light of the substrate). However, since the optical sheet used in the touch panel of Embodiment B satisfies the condition (B2), even if a transparent substrate with a small retardation value is used, the color unevenness of the gradation color can be made difficult to notice.

Furthermore, even if the retardation value is reduced, the unevenness of the gradation color can be made less noticeable because of the fact that the thickness of the transparent substrate can be made thinner. That is, with regard to a transparent substrate (for example, a polyester film as a general-purpose substrate) that generates retardation, generally, the retardation value is increased by performing uniaxial stretching to increase the thickness of the substrate, thereby suppressing Uneven color resulting in gradation. However, about For the optical sheet used in the touch panel of Embodiment B, even if the thickness of the transparent substrate (for example, polyester film as a general substrate) is made thin, the uneven color of the gradation can be difficult to attract Attention.

Furthermore, even if the retardation value is reduced, the uneven color of the gradation color can be difficult to be noticeable. The situation is related to the following conditions, and it can be used normally because the color unevenness of the gradation color is easy to occur, such as outside the choice. Plastic film (polyimide film, polyaramide film). The polyimide film and the polyaramide film are preferable in that they are excellent in flexibility resistance.

In recent years, there has been a tendency for the color gamut of display devices to expand. A display element with a wide color gamut has a steep shape in the spectral spectra of each color (R, G, B). For this type of display element, the color unevenness of the gradation specific to the retardation value tends to be particularly noticeable. Regarding the optical sheet used in the touch panel of Embodiment B, it is preferable in that even for a display element with a wide color gamut, the uneven color of the gradation color can be made less noticeable.

The optical sheet may have functional layers such as an anti-reflection layer, an anti-fouling layer, and an anti-static layer on the surface of the unevenness and/or on the opposite side of the unevenness. In addition, in the case of a structure having a concavo-convex layer on a transparent substrate, in addition to the above-mentioned portions, a functional layer may be provided between the transparent substrate and the concavo-convex layer.

Furthermore, when other functional layers are laminated on the uneven layer, the unevenness on the outermost surface meets the scope of this application. The concavity and convexity may be a single layer or multiple layers as long as the outermost surface is within the scope of the present application.

The touch panel of Embodiment B provides outdoor anti-glare properties by the uneven shape of the above-mentioned optical sheet, and is excellent in operability. In addition, it is also possible to suppress the decrease in resolution.

Therefore, the touch panel of Embodiment B is preferably installed in the display device of a mobile phone or tablet (multifunctional mobile terminal) carried on a car such as a display device for a car and a train. The exit surface side.

[Display device]

The display device of Embodiment B has unevenness on the outermost surface of the exit surface side of the display element, and the unevenness satisfies the above-mentioned conditions (B1) and (B2).

The display device of the embodiment B can use the same optical sheet as that used in the touch panel of the above-mentioned embodiment B as a member having unevenness on the outermost surface.

As the display element, a liquid crystal display element, an in-cell touch panel liquid crystal display element, an EL display element, a plasma display element, etc. can be mentioned. Furthermore, the liquid crystal display element has a backlight device on the back of the liquid crystal element.

The in-cell touch panel liquid crystal element is a liquid crystal element that is formed by sandwiching liquid crystal between two glass substrates and has a resistive film type, an electrostatic capacitance type, an optical type, and other touch panel functions. Furthermore, as the display method of the liquid crystal of the in-cell touch panel liquid crystal element, IPS method, VA method, multi-domain method, OCB method, STN method, TSTN method, etc. can be cited. The in-cell touch panel liquid crystal element is described in, for example, Japanese Patent Application Publication No. 2011-76602 and Japanese Patent Application Publication No. 2011-222009.

The optical sheet can be arranged on the exit surface side of the display element in the following order, for example.

(a) Display element/Surface protection board/Optical sheet

(b) Display element/optical sheet

(c) Touch panel with display element/optical sheet on the top

In the cases of (a) and (b), the display device can be provided with outdoor anti-glare properties by arranging the concave and convex of the optical sheet toward the opposite side of the display element. In addition, the reduction of the resolution of the display element can be suppressed, and the scars generated on the surface or the display element can be made difficult to see.

In the case of (c), the display device is a display device with a touch panel provided with a touch panel with an optical sheet on the uppermost part on the exit surface side of the display element. In this case, a display device with excellent outdoor anti-glare properties, high resolution, and operability of the touch panel can be made.

Therefore, the display device of Embodiment B is preferably used as an in-vehicle display device, a smart phone or a tablet (multifunctional mobile terminal) carried when traveling on a train, etc.

As described above, regarding the optical sheet used in the display device of Embodiment B, even for a display element with a wide color gamut, the color unevenness of the gradation color can be made difficult to notice. As a standard for representing the color gamut, "ITU-R Recommendation BT.2020 (hereinafter referred to as "BT.2020")" and the like can be cited. ITU-R is the abbreviation of "International Telecommunication Union-Radiocommunication Sector". ITU-R advises that BT.2020 is an international standard for the color gamut of high-definition television.

Regarding the display device of Embodiment B, even for a display element with a coverage rate of 60% or more based on BT.2020 of the CIE-xy chromaticity diagram represented by the following formula, the uneven color of the gradation can be made difficult to attract Attention.

<Expression of the coverage of BT.2020> [The area of the CIE-xy chromaticity diagram of the display device that overlaps with the area of the CIE-xy chromaticity diagram of BT.2020/CIE-xy color of BT.2020 The area of the degree map]×100(%)

Furthermore, the "CIE-xy chromaticity diagram area" necessary to calculate the coverage of BT.2020 is to measure the CIE- with red (R) display, green (G) display, and blue (B) display. The x and y values of the Yxy color system can be obtained from the "red (R) vertex coordinates", "green (G) vertex coordinates" and "blue (B) vertex coordinates" obtained from the measurement results "Calculated. The x value and y value of the CIE-Yxy color system can be used, for example, by Konica Minolta The manufactured spectroradiometer CS-2000 was used for measurement.

Examples of display elements with a wide color gamut include: three-color independent organic EL display device (among them, three-color independent organic EL device with a microcavity structure), a liquid crystal display element with quantum dots used as a backlight, and a backlight The device uses three-wavelength white LED (near ultraviolet LED, a combination of blue phosphor, green phosphor, and red phosphor) liquid crystal display elements, etc.

[Optical Sheet]

The optical sheet of Embodiment B has concavities and convexities on one surface, and the concavities and convexities satisfy the above-mentioned conditions (B1) and (B2). Furthermore, in the optical sheet of Embodiment B, when other functional layers are laminated on the above-mentioned concavities and convexities, the concavities and convexities on the outermost surface satisfy the scope of the present application. The concavity and convexity may be a single layer or multiple layers as long as the outermost surface is within the scope of the present application.

As an optical sheet of Embodiment B, the same optical sheet used for the touch panel of the above-mentioned Embodiment B can be mentioned.

When the optical sheet of Embodiment B is used for a touch panel, the optical sheet is installed in such a way that the surface with unevenness becomes the surface on the operator side of the touch panel.

In order to satisfy the above-mentioned conditions (B1) and (B2), the optical sheet of Embodiment B is placed on the uppermost part of the touch panel, thereby imparting outdoor anti-glare properties to the touch panel and making the touch panel The operability becomes excellent.

Therefore, the optical sheet of Embodiment B can be preferably used on the surface of a vehicle-mounted display device, and the surface of a smartphone or tablet (multifunctional mobile terminal) carried when moving on a train, etc.

[Screening method of optical film]

The screening method of the optical sheet of embodiment B is to select one surface with unevenness, and the unevenness meets the above The optical sheets of the conditions (B1) and (B2) are regarded as the optical sheets located on the uppermost part of the touch panel.

In the optical sheet screening method of Embodiment B, even if the optical sheet operability test is not performed, it is possible to screen optical sheets with good operability, outdoor anti-glare properties and high resolution, and can be performed efficiently Product design and quality management of optical films.

Regarding the judging conditions for screening the optical sheets of the touch panel, the above-mentioned conditions (B1) and (B2) are set as necessary conditions. Regarding the judgment condition of the condition (B1), for example, the ratio (μs/μk) when the load is 50 to 150 g is preferably in the range of 1.6 to 2.5, and more preferably in the range of 1.7 to 2.2. In addition, the ratio (μs/μk) when the load is 900 to 1100 g is preferably in the range of 1.0 to 1.5, and more preferably in the range of 1.1 to 1.4. In addition, the determination condition of the condition (B2) preferably satisfies 0.15 μm≦Ra _2.5 ≦0.60 μm, more preferably satisfies 0.25 μm≦Ra _2.5 ≦0.55 μm, and more preferably satisfies 0.30 _{μm≦Ra 2.5} ≦0.50 μm.

Regarding the selection method of the optical sheet of the touch panel, from the viewpoint of excellent operability and outdoor anti-glare properties, it is further preferable to set the following condition (B3) as a newly added judgment condition.

Rz _0.8 /(Rz _2.5 -Rz _0.8 )≦3.2 (B3)

The judgment condition of the condition (B3) is preferably the preferable numerical range of the optical sheet of the above-mentioned embodiment B.

Furthermore, it is preferable to set other parameters as newly added judgment conditions.

[Example]

Hereinafter, the present invention will be specifically described with examples and comparative examples, but the present invention is not limited to the form described in the examples. Furthermore, "parts" and "%" are set as quality standards as long as they are not specifically stated in advance.

<Example of Embodiment A>

A1. Measurement and evaluation

With respect to the optical sheets produced in the examples and comparative examples, the following measurements and evaluations were performed. The results are shown in Table 1.

A1-1. Static friction coefficient

Using HEIDON HHS2000 manufactured by Shinto Science Co., Ltd., the static friction coefficient is measured by the following method under a certain load reciprocating friction measurement mode.

A sapphire needle with a tip radius of 0.3mm is vertically in contact with the unevenness of the optical sheet, a vertical load of 100g is applied to the needle, and at the same time, the squeegee is made to perform one round trip with a length of 10mm at a scanning speed of 10mm/sec. At this time, it was measured as the static friction coefficient (μs10) of the scraper. _{In addition, the static friction coefficient (μs 20} ) when the scanning speed was set to 20 mm/sec was measured.

Furthermore, the atmosphere at the time of measurement is set to a temperature of 23°C±5°C and a humidity of 50%±10%. Also, before the start of the measurement, place each sample in an atmosphere of 23°C±5°C and a humidity of 50%±10% for more than 10 minutes.

A1-2. Surface roughness measurement (cut-off value 2.5mm)

The optical sheets of the examples and comparative examples were cut into 10 cm squares. After visually confirming that there are no abnormalities such as dust or damage, the cutting part is selected from a random part. The cut surface member is prepared to be pasted on a black board (manufactured by Kuraray Co., Ltd., trade name: Comoglas product) with a size of 10 cm in length × 10 cm in width via an optically transparent adhesive sheet (refractive index: 1.47, thickness 100 μm) manufactured by Toray. Code: DFA502K, thickness 2.0mm) each made of 20 samples.

Use a surface roughness measuring device (model: SE-3400/manufactured by Kosaka Laboratories Co., Ltd.) and set it in a state where the sample is fixed and closely attached to the measurement platform, and then measure the unevenness of the optical sheet according to the following measurement conditions JIS B0601: Ra, Rz, S, and Sm of 1994. The calculation of θa is based on the operation manual of the surface roughness measuring instrument (SE-3400) manufactured by Kosaka Research Institute (revised on July 20, 1995). The average value of 20 samples was taken as Ra, Rz, S, Sm, and θa of each Example and Comparative Example. The atmosphere during the measurement is set to a temperature of 23℃±5℃ and a humidity of 50%±10%. Also, before the start of the measurement, place each sample in an atmosphere of 23°C±5°C and a humidity of 50%±10% for more than 10 minutes.

[The stylus of the surface roughness detection department]

Product name SE2555N manufactured by Kosaka Research Institute Co., Ltd. (tip radius of curvature: 2μm, vertex angle: 90 degrees, material: diamond)

[Measurement conditions of surface roughness measuring instrument]

‧Standard length (cut-off value of roughness curve λc): 2.5mm

‧Evaluation length (reference length (cut-off value λc)×5): 12.5mm

‧Conveying speed of stylus: 0.5mm/s

‧Longitudinal magnification: 2000 times

‧Horizontal magnification: 10 times

‧Slide (skid): not used (not in contact with the measuring surface)

‧Type of cutoff filter: Gaussian

‧The degree of non-inductive zone: 10%

‧Tp/PC curve: normal

A1-3. Surface roughness measurement (cut-off value 0.8mm)

Using a surface roughness measuring device (model: SE-3400/manufactured by Kosaka Research Institute Co., Ltd.), the Rz of JIS B0601: 1994 of the concave and convex surfaces of the 20 samples was measured under the following measurement conditions. The average value of 20 samples was taken as the Rz of each Example and Comparative Example.

[The stylus of the surface roughness detection department]

Product name SE2555N manufactured by Kosaka Research Institute Co., Ltd. (tip radius of curvature: 2μm, vertex angle: 90 degrees, material: diamond)

[Measurement conditions of surface roughness measuring instrument]

‧Standard length (cut-off value of roughness curve λc): 0.8mm

‧Evaluation length (reference length (cut-off value λc)×5): 4.0mm

‧Conveying speed of stylus: 0.5mm/s

‧Longitudinal magnification: 2000 times

‧Horizontal magnification: 10 times

‧Slide: Not used (not in contact with the measuring surface)

‧Type of cutoff filter: Gaussian

‧The degree of non-inductive zone: 10%

‧Tp/PC curve: normal

A1-4. Outdoor anti-glare

The black acrylic plate was bonded to the substrate side of the obtained optical sheet via a transparent adhesive to prepare an evaluation sample. Then, in an environment with an illuminance of 7000~13000 lux (an environment in front of a window on a sunny day), each evaluation sample was set horizontally on a water platform with a height of about 1m, and 20 people used visual observation from about 50cm above at various angles. The evaluation is performed based on the following criteria, and the most numerous evaluations are used as the result.

A: The dazzling of sunlight is not felt on the surface of the sample.

B: The viewing angle is slightly dazzling from sunlight on the surface of the sample, but it is within the allowable range.

C: The dazzling of sunlight is strongly felt on the surface of the sample.

A1-5. Resolution

The substrate side of the obtained optical sheet is pasted on the glass on the outermost surface of a commercially available mobile phone (7.9-inch LCD) via a transparent adhesive, under an illuminance of 7000~13000 lux (in front of the window on a sunny day) , Each display device is set horizontally on a water platform with a height of about 1m, and 20 people use visual observation from about 30cm above to confirm the icons and characters of the initial screen of each display device at various angles. Set 2 points for those who can recognize icons and characters well; set 1 point for those who can recognize icons and characters within the range that will not hinder the operation; set the icons and characters difficult to distinguish and hinder the operator to 0 Points for evaluation. If the average score of 20 people is 1.6 points or more, it is set as A, those with 1.2 points or more and less than 1.6 points are set as B, and those with less than 1.2 points are set as C.

A1-6. Touch (slidability)

A 10 cm square acrylic plate was attached to the substrate side of the obtained optical sheet. Then, perform the following two kinds of operations conceived of operating with the touch panel.

Twenty people performed this operation, and those with extremely good tactile sensations were rated as 2 points, those with good tactile sensations were rated as 1 point, and those with poor tactile sensations were rated as 0 points for evaluation. If the average score of 20 people is 1.6 points or more, it is set as A, those with 1.2 points or more and less than 1.6 points are set as B, and those with less than 1.2 points are set as C.

<Operation 1 (Scroll Operation)>

Use index finger to operate. Proceed as follows: Press the board with the dominant hand, and move the concave and convex surface of the optical sheet along the left and right directions with the finger pads of the fingers that are not the dominant hand for about 5 cm in a distance of about 1 second. This operation 1 was repeated 5 times.

<Operation 2 (Enlargement and Reduction Operation)>

Press the board with your dominant hand, and place the lateral sides of the index finger and thumb that are not the dominant hand on the approximate center of the uneven surface of the optical sheet, and move the index finger and thumb at the same time for about 1 second for 2~3. cm, and the operation when expanding. Immediately after that, the operation for shrinking to the original center is performed. This operation 2 was repeated 5 times.

A1-7. Stuck feeling of fingers at the beginning of the operation

Prepare the same sample as the above (A1-6), and 20 people will perform the above 1 and 2 operations. In Operation 1 and Operation 2, set the fingers with the same degree of stuttering to 2 points, set the fingers with slightly different degree of stuttering to 1 point, and set the fingers with different degrees of stuttering to 0 for evaluation. . If the average score of 20 people is 1.6 points or more, it is set as A, those with 1.2 points or more and less than 1.6 points are set as B, and those with less than 1.2 points are set as C.

A2. Production of optical film

[Example A1]

Coat the plastic film (thickness 80μm triacetyl cellulose resin film (TAC), manufactured by Fujifilm Co., Ltd., TD80UL) with the concave-convex layer coating solution A1 of the following formula, and dry for 30 seconds at 70°C and wind speed of 5m/s After an hour, ultraviolet rays were irradiated in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) so that the cumulative light amount became 100 mJ/cm ² to form a concavo-convex layer, and an optical sheet was obtained. The film thickness of the uneven layer is 7 μm.

<Concavo-convex layer coating liquid A1>

‧55 parts of di-trimethylolpropane tetraacrylate

(Manufactured by SARTOMER, SR355)

‧3 parts of photopolymerization initiator

(Manufactured by BASF, Irgacure 184)

‧Polysiloxane-based leveling agent 0.25 parts

(Manufactured by Momandif Specialty Materials Co., Ltd., TSF4460)

‧10 parts of spherical polyacrylic acid-styrene copolymer particles

(Average particle size 6μm, refractive index 1.52)

‧100 parts of colloidal silica particles (reactive hydrophobic treatment)

(Manufactured by Nissan Chemical Industry Co., Ltd., solvent MIBK, solid content 30%) (average particle size 10-15nm)

‧110 parts of solvent (MIBK)

[Example A2]

The uneven layer coating liquid A1 of Example A1 was changed to the uneven layer coating liquid A2 of the following formulation, and the film thickness was 6 μm, except that the optical sheet was obtained in the same manner as in Example A1.

<Concavo-convex layer coating liquid A2>

‧60 parts of multifunctional acrylate oligomer

(Manufactured by Nippon Synthetic Chemical Industry Co., Ltd., UV7640B functional group number 6~7)

‧3 parts of photopolymerization initiator

(Manufactured by BASF, Irgacure 184)

‧Polysiloxane leveling agent: 0.2 part of polyester modified polydimethylsiloxane

(Manufactured by BYK-CHEMIE, BYK370)

‧Spherical polyacrylic acid-styrene copolymer particles 16 parts

(Average particle size 3.5μm, refractive index 1.52)

‧Fumed silica particles (hydrophobic treatment: octyl silane treatment) 6 parts

(Manufactured by Airotech Co., Ltd., with an average particle size of 10~15nm)

‧Solvent 1 (toluene) 135 parts

[Example A3]

The uneven layer coating liquid A1 of Example A1 was changed to the uneven layer coating liquid A3 of the following formulation, and the film thickness of the uneven layer was set to 2.5 μm, except that the optical fiber was obtained in the same manner as in Example A1. piece.

<Concavo-convex layer coating liquid A3>

‧100 parts of neopentylerythritol triacrylate

(Manufactured by Nippon Kayaku Co., Ltd., KAYARAD-PET-30)

‧14 parts of inorganic particles

(Manufactured by Fuji Silica Chemical Co., Ltd., amorphous silica)

(Hydrophobic treatment, silane coupling agent, average aggregate particle size 2μm)

‧5 parts of photopolymerization initiator

(Manufactured by BASF, Irgacure 184)

‧Polysiloxane-based leveling agent 0.2 part

(TSF4460 manufactured by Momandif Specialty Materials Co., Ltd.)

‧2 parts of release agent

(Manufactured by Daikin Industrial Co., Ltd., OPTOOL DAC)

‧150 parts of solvent 1 (toluene)

‧35 parts of solvent 2 (MIBK)

[Comparative Example A1]

The uneven layer coating liquid A1 of Example A1 was changed to the uneven layer coating liquid A4 of the following formulation, and the film thickness of the uneven layer was set to 4 μm, except that the optical sheet was obtained in the same manner as in Example A1 .

<Concavo-convex layer coating liquid A4>

‧Aliphatic polyester skeleton 6-functional acrylic urethane 100 parts

(Manufactured by SARTOMER, CN968)

‧3 parts of spherical polyacrylic acid-styrene copolymer particles

(Average particle size 2.5μm, refractive index 1.52)

‧Smoked silicon particles (hydrophobic treatment: methyl) 3 parts

(Manufactured by Airotech Co., Ltd., with an average particle size of 10~15nm)

‧3 parts of photopolymerization initiator

(Manufactured by BASF, Irgacure184)

‧Polysiloxane leveling agent: 0.2 part of polysiloxane modified polysiloxane

(Manufactured by Shin-Etsu Silicones Co., Ltd., KF6004)

‧150 parts of solvent 1 (toluene)

‧35 parts of solvent 2 (MIBK)

[Comparative Example A2]

The uneven layer coating liquid A1 of Example A1 was changed to the uneven layer coating liquid A5 of the following formulation, and the film thickness of the uneven layer was set to 3 μm, except that the optical sheet was obtained in the same manner as in Example A1 .

<Concavo-convex layer coating liquid A5>

‧Aliphatic polyester skeleton 6-functional acrylic urethane 100 parts

(Manufactured by SARTOMER, CN968)

‧Amorphous silica particles (hydrophobic treatment: silane coupling agent) 15 parts

(Manufactured by Fuji Silesia Chemical Co., Ltd., average agglomerated particle size 2.5μm)

‧3 parts of photopolymerization initiator

(Manufactured by BASF, Irgacure184)

‧Polysiloxane leveling agent: 0.2 part of polyether modified polysiloxane

(Manufactured by Shin-Etsu Silicones Co., Ltd., X-22-2516)

‧150 parts of solvent (toluene)

According to the results in Table 1, it can be seen that the optical sheets of Examples A1~A3 can be used for outdoor It has anti-glare properties and can improve resolution and operability.

A3. Production of touch panel

On the transparent substrate side of the optical sheets of Examples A1 to A3 and Comparative Examples A1 and A2, an ITO conductive film with a thickness of 20 nm was formed by a sputtering method to form an upper electrode plate. Then, an ITO conductive film with a thickness of about 20 nm was formed on one surface of a strengthened glass plate with a thickness of 1 mm by a sputtering method to form a lower electrode plate. Then, by screen printing, the ionizing radiation curable resin (Dot Cure TR5903: Sun Ink Co., Ltd.) as a coating solution for spacers was printed in dots on the conductive film surface of the lower electrode plate. The mercury lamp was irradiated with ultraviolet rays, and spacers with a diameter of 50 μm and a height of 8 μm were arranged at intervals of 1 mm.

Then, the upper electrode plate and the lower electrode plate were arranged so that the conductive films were opposed to each other, and the edges were bonded with a double-sided tape having a thickness of 30 μm and a width of 3 mm to produce Examples A1 to A3 and Comparative Examples A1. A2 resistive film type touch panel.

The resistive film type touch panels of Examples A1 to A3 have outdoor anti-glare properties, and have good resolution and operability. On the other hand, the resistive film type touch panel of Comparative Example A1 is dazzling due to insufficient outdoor anti-glare properties, and its operability is reduced. In addition, the resistive film type touch panel of Comparative Example A2 cannot recognize the image and text information of the display screen due to excessive outdoor anti-glare properties.

A4. Production of display device (1)

The optical sheets of Examples A1 to A3 and Comparative Examples A1 and A2 were bonded to the surface glass plate of a commercially available ultra-high-definition liquid crystal display device (4.7 inches, pixel density about 320ppi) through a transparent adhesive to produce an example Display devices (1) of A1 to A3 and comparative examples A1 and A2. Furthermore, when bonding, the uneven surface of the optical sheet is directed to the side opposite to the display element.

The display device (1) obtained by visual evaluation was used for the presence or absence of glare, and the results were related to Example A1 ~A3 display device (1), the glare is suppressed, the reflection of external light is also less, and the visibility is good. In addition, the display devices (1) of the embodiments A1 to A3 will not damage the resolution of the ultra-high-definition image.

A5. Production of display device (2)

The base material of the optical sheets of Examples A1 to A3 and Comparative Examples A1 and A2 was changed to a polyethylene terephthalate film with a thickness of 50 μm (retardation value 2,500 nm). Otherwise, the same as those of Examples A1 to A3 and In the same manner as Comparative Examples A1 and A2, optical sheets of Examples A4 to A6 and Comparative Examples A3 and A4 were produced. The physical property values in Table 1 of the optical sheets of Examples A4 to A6 and Comparative Examples A3 and A4 are approximately the same as those of Examples A1 to A3 and Comparative Examples A1 and A2.

The optical sheets of Examples A4 to A6 and Comparative Examples A3 and A4, and a commercially available organic EL display device with a polarizing element on a three-color independent organic EL display element with a microcavity structure (based on the CIE-xy chromaticity diagram BT.2020 (coverage rate: 77%) surface glass plates were pasted through a transparent adhesive to fabricate the display devices (2) of Examples A4 to A6 and Comparative Examples A3 and A4. Furthermore, when bonding, the uneven surface of the optical sheet is directed to the side opposite to the display element.

[Evaluation of Display Device (2)]

<The uneven color of the gradient>

The screen of the display device (2) is displayed in white or almost white. The screen was visually observed from various angles through polarized sunglasses. According to the following criteria, 20 people evaluated whether the uneven color of the gradual color could be recognized, and the most evaluation was set as the result. The results are shown in Table 2.

A: The uneven color of the gradient color cannot be recognized.

B: The gradual color is not always recognizable, but it will not hinder the image quality.

C: The uneven color of the gradation is clearly recognized, which will seriously hinder the image quality.

The display elements constituting the display device (2) have a very wide color gamut, which is easy to produce gradation The color is uneven, but the display devices of Examples A4 to A6 can hardly recognize the uneven color of the gradation. In particular, since the display device of Example A6 has a large Ra and a moderately random uneven shape, the color unevenness of the gradation color is almost completely unrecognizable.

<Example of Embodiment B>

B1. Measurement and evaluation

With respect to the optical sheets produced in the examples and comparative examples, the following measurements and evaluations were performed. The results are shown in Table 3.

B1-1. Friction coefficient

Using the trade name HEIDON NHS2000 manufactured by Shinto Science Co., Ltd., the static friction coefficient μs and the dynamic friction coefficient μk are measured by the following method under a certain load reciprocating friction measurement mode, and the ratio (μs/μk) is calculated.

A sapphire needle with a tip radius of 0.3mm is vertically in contact with the unevenness of the optical sheet, a vertical load of 100g is applied to the needle, and at the same time the squeegee is made to perform one round trip with a length of 10mm at a scanning speed of 5mm/sec. At this time, the kinetic friction coefficient μk of the scraping needle was measured. In addition, by the same operation, the dynamic friction coefficient μk when the vertical load applied to the squeegee needle is 500g and 1000g is measured. Furthermore, in the same manner as the above operation, the static friction coefficient μs when the vertical load applied to the squeegee needle is 100 g, 500 g, and 1000 g is measured.

Furthermore, the atmosphere at the time of measurement is set to a temperature of 23°C±5°C and a humidity of 50%±10%. Also, Yu Ce Before the start of the measurement, place each sample in an atmosphere of 23°C±5°C and a humidity of 50%±10% for more than 10 minutes.

The numerical formulas of Examples B1, B2, and Comparative Example B4 shown in Table 3 are all approximate linear straight lines calculated by the least square method.

B1-2. Surface roughness measurement (cut-off value 2.5mm)

The optical sheets of the examples and comparative examples were cut into 10 cm squares. After visually confirming that there are no abnormalities such as dust or damage, the cutting part is selected from a random part. The cut surface member is prepared to be pasted on a black board (manufactured by Kuraray Co., Ltd., trade name: Comoglas product) with a size of 10 cm in length × 10 cm in width via an optically transparent adhesive sheet (refractive index: 1.47, thickness 100 μm) manufactured by Toray. Code: DFA502K, thickness 2.0mm) each made of 20 samples.

Use a surface roughness measuring device (model: SE-3400/manufactured by Kosaka Laboratories Co., Ltd.) and set it in a state where the sample is fixed and closely attached to the measurement platform, and then measure the unevenness of the optical sheet according to the following measurement conditions JIS B0601: Ra, Rz, S, and Sm of 1994. The calculation of θa is based on the operation manual of the surface roughness measuring instrument (SE-3400) manufactured by Kosaka Research Institute (revised on July 20, 1995). The average value of 20 samples was taken as Ra, Rz, S, Sm, and θa of each Example and Comparative Example. The atmosphere during the measurement is set to a temperature of 23℃±5℃ and a humidity of 50%±10%. Also, before the start of the measurement, place each sample in an atmosphere of 23°C±5°C and a humidity of 50%±10% for more than 10 minutes.

[The stylus of the surface roughness detection department]

Product name SE2555N manufactured by Kosaka Research Institute Co., Ltd. (tip radius of curvature: 2μm, vertex angle: 90 degrees, material: diamond)

[Measurement conditions of surface roughness measuring instrument]

‧Standard length (cut-off value of roughness curve λc): 2.5mm

‧Evaluation length (reference length (cut-off value λc)×5): 12.5mm

‧Conveying speed of stylus: 0.5mm/s

‧Longitudinal magnification: 2000 times

‧Horizontal magnification: 10 times

‧Slide: Not used (not in contact with the measuring surface)

‧Type of cutoff filter: Gaussian

‧The degree of non-inductive zone: 10%

‧Tp/PC curve: normal

B1-3. Surface roughness measurement (cut-off value 0.8mm)

Using a surface roughness measuring device (model: SE-3400/manufactured by Kosaka Research Institute Co., Ltd.), the Rz of JIS B0601: 1994 of the concave and convex surfaces of the 20 samples was measured under the following measurement conditions. The average value of 20 samples was taken as the Rz of each Example and Comparative Example.

[The stylus of the surface roughness detection department]

Product name SE2555N manufactured by Kosaka Research Institute Co., Ltd. (tip radius of curvature: 2μm, vertex angle: 90 degrees, material: diamond)

[Measurement conditions of surface roughness measuring instrument]

‧Standard length (cut-off value of roughness curve λc): 0.8mm

‧Evaluation length (reference length (cut-off value λc)×5): 4.0mm

‧Conveying speed of stylus: 0.5mm/s

‧Longitudinal magnification: 2000 times

‧Horizontal magnification: 10 times

‧Slide: Not used (not in contact with the measuring surface)

‧Type of cutoff filter: Gaussian

‧The degree of non-inductive zone: 10%

‧Tp/PC curve: normal

B1-4. Outdoor anti-glare

A black acrylic plate was bonded to the substrate side of the obtained optical sheet via a transparent adhesive to prepare a sample for evaluation. Then, under an environment with an illuminance of 7000 to 13000 lux (in front of the window on a sunny day), each evaluation sample was set horizontally on a water platform with a height of about 1m, and 20 people visually evaluated from about 50cm above at various angles. Evaluate based on the following criteria, and use the largest number of evaluations as the result.

A: The dazzling of sunlight is not felt on the surface of the sample.

B: The viewing angle is slightly dazzling from sunlight on the surface of the sample, but it is within the allowable range.

C: The dazzling of sunlight is strongly felt on the surface of the sample.

B1-5. Analytical

The substrate side of the obtained optical sheet is pasted on the glass on the outermost surface of a commercially available mobile phone (7.9-inch LCD) via a transparent adhesive, under an illuminance of 7000~13000 lux (in front of the window on a sunny day) , Each display device is set horizontally on a water platform with a height of about 1m, and 20 people use visual observation from about 30cm above to confirm the icons and characters of the initial screen of each display device at various angles. Set 2 points for those who can recognize icons and characters well; set 1 point for those who can recognize icons and characters within the range that will not hinder the operation; set the icons and characters difficult to distinguish and hinder the operator to 0 Points for evaluation. If the average score of 20 people is 1.6 points or more, it is set as A, those with 1.2 points or more and less than 1.6 points are set as B, and those with less than 1.2 points are set as C.

B1-6. Operability

A sample with a 10 cm square acrylic plate attached to the substrate side of the obtained optical sheet was prepared. Then, move the finger on the concave and convex surface of the optical sheet of the sample to switch the direction. The operation is for each person under a light load (when standing, hold the sample with the hand opposite to the dominant hand, and use the dominant hand to operate the load), heavier load (put the sample on the table, use Fix the sample with the hand on the opposite side of the dominant hand, and use the dominant hand to operate the load under two types of loads). When operating any load, you can easily change the direction. If you feel that the operability is good, set it to 2 points. When operating at least one load, slide your finger slightly when changing the direction, or change the direction. When the finger is slightly heavier, but the operability is slightly abnormal, it is set to 1 point. When operating at least one load, the finger slides when the direction is changed, or the finger is heavier when the direction is changed. Those with obvious abnormality in operability were set as 0 points and evaluated by 20 people. If the average score of 20 people is 1.6 or more is set as A, if the score is 1.0 or more and less than 1.6 is set as B, if the score is 0.5 or more and less than 1.0 is set as C, and the score is less than 0.5. Set as D.

B-2. Production of optical film

[Example B1]

Coating solution B1 for the uneven layer with the following formula was coated on a plastic film (thickness 80μm triacetyl cellulose resin film (TAC), manufactured by Fujifilm Co., Ltd., TD80UL), and dried for 30 seconds at 70°C and wind speed of 5m/s After an hour, ultraviolet rays were irradiated in a nitrogen atmosphere (oxygen concentration of 200 ppm or less) so that the cumulative light amount became 100 mJ/cm ² to form a concavo-convex layer, and an optical sheet was obtained. The film thickness of the uneven layer is 2.5 μm.

<Concavo-convex layer coating liquid B1>

‧100 parts of neopentylerythritol triacrylate

(Manufactured by Nippon Kayaku Co., Ltd., KAYARAD-PET-30)

‧14 parts of inorganic particles

(Manufactured by Fuji Silica Chemical Co., Ltd., amorphous silica)

(Hydrophobic treatment, silane coupling agent, average aggregate particle size 2μm)

‧5 parts of photopolymerization initiator

(Manufactured by BASF, Irgacure184)

‧Polysiloxane-based leveling agent 0.2 part

(TSF4460 manufactured by Momandif Specialty Materials Co., Ltd.)

‧2 parts of release agent

(Manufactured by Daikin Industrial Co., Ltd., OPTOOL DAC)

‧150 parts of solvent 1 (toluene)

‧35 parts of solvent 2 (MIBK)

[Example B2]

The uneven layer coating liquid B1 of Example B1 was changed to the uneven layer coating liquid B2 of the following formulation, and the film thickness of the uneven layer was set to 4 μm, except that the optical sheet was obtained in the same manner as in Example B1 .

<Concavo-convex layer coating liquid B2>

‧100 parts of neopentylerythritol tetraacrylate

(Manufactured by Kyoeisha Chemical Co., Ltd., Light acrylate PE-4)

‧Amorphous silica particles (hydrophobic treatment: silane coupling agent) 3 parts

(Manufactured by Fuji Silesia Chemical Co., Ltd., with an average agglomerated particle size of 3μm)

‧Amorphous silica particles (hydrophobic treatment: silane coupling agent) 3 parts

(Manufactured by Fuji Silesia Chemical Co., Ltd., average agglomerated particle size 1.5μm)

‧3 parts of photopolymerization initiator

(Manufactured by BASF, Irgacure184)

‧Polysiloxane leveling agent: 0.2 part of polyether modified polysiloxane

(Manufactured by Shin-Etsu Silicones Co., Ltd., KF6004)

‧150 parts of solvent (toluene)

[Comparative Example B1]

The uneven layer coating liquid B1 of Example B1 was changed to the uneven layer coating liquid B3 of the following formulation, and the film thickness of the uneven layer was set to 7 μm, except that the optical sheet was obtained in the same manner as in Example B1 .

<Concavo-convex layer coating liquid B3>

‧55 parts of di-trimethylolpropane tetraacrylate

(Manufactured by SARTOMER, SR355)

‧3 parts of photopolymerization initiator

(Manufactured by BASF Corporation, Irgacure184)

‧Polysiloxane-based leveling agent 0.25 parts

(Manufactured by Momandif Specialty Materials Co., Ltd., TSF4460)

‧10 parts of spherical polyacrylic acid-styrene copolymer particles

(Average particle size 6μm, refractive index 1.52)

‧100 parts of colloidal silica particles (reactive hydrophobic treatment)

(Manufactured by Nissan Chemical Industry Co., Ltd., solvent MIBK, solid content 30%) (average particle size 10-15nm)

‧110 parts of solvent (MIBK)

[Comparative Example B2]

The uneven layer coating liquid B1 of Example B1 was changed to the uneven layer coating liquid B4 of the following formulation, and the film thickness of the uneven layer was set to 7 μm, except that the optical sheet was obtained in the same manner as in Example B1 .

<Concavo-convex layer coating liquid B4>

‧60 parts of multifunctional acrylate oligomer

(Manufactured by Nippon Synthetic Chemical Industry Co., Ltd., UV7640B functional group number 6~7)

‧3 parts of photopolymerization initiator

(Manufactured by BASF, Irgacure184)

‧Polysiloxane leveling agent: 0.2 part of polyester modified polydimethylsiloxane

(Manufactured by BYK-CHEMIE, BYK370)

‧Spherical polyacrylic acid-styrene copolymer particles 16 parts

(Average particle size 3.5μm, refractive index 1.52)

‧Smoked silicon particles (hydrophobic treatment: octyl silane treatment) 6 parts

(Manufactured by Airotech Co., Ltd., with an average particle size of 10~15nm)

‧Solvent 1 (toluene) 135 parts

[Comparative Example B3]

The uneven layer coating liquid B1 of Example B1 was changed to the uneven layer coating liquid B5 of the following formulation, and the film thickness of the uneven layer was set to 4 μm, except that the optical sheet was obtained in the same manner as in Example B1 .

<Concavo-convex layer coating liquid B5>

‧Aliphatic polyester skeleton 6-functional acrylic urethane 100 parts

(Manufactured by SARTOMER, CN968)

‧3 parts of spherical polyacrylic acid-styrene copolymer particles

(Average particle size 2.5μm, refractive index 1.52)

‧Smoked silicon particles (hydrophobic treatment: methyl) 3 parts

(Manufactured by Airotech Co., Ltd., with an average particle size of 10~15nm)

‧3 parts of photopolymerization initiator

(Manufactured by BASF, Irgacure184)

‧Polysiloxane leveling agent: 0.2 part of polyether modified polysiloxane

(Manufactured by Shin-Etsu Silicones Co., Ltd., KF6004)

‧150 parts of solvent 1 (toluene)

‧35 parts of solvent 2 (MIBK)

[Comparative Example B4]

The uneven layer coating liquid B1 of Example B1 was changed to the uneven layer coating liquid B6 of the following formulation, and the film thickness of the uneven layer was set to 3.8 μm, except that the optical sheet was obtained in the same manner as in Example B1 .

<Concavo-convex layer coating liquid B6>

‧100 parts of neopentylerythritol tetraacrylate

(Manufactured by Kyoeisha Chemical Co., Ltd., Light acrylate PE-4A)

‧Amorphous silica particles (hydrophobic treatment: silane coupling agent) 10 parts

(Manufactured by Fuji Silesia Chemical Co., Ltd., with an average agglomerated particle size of 3.5μm)

‧Amorphous silica particles (hydrophobic treatment: silane coupling agent) 8 parts

(Manufactured by Fuji Silesia Chemical Co., Ltd., with an average agglomerated particle size of 2μm)

‧3 parts of photopolymerization initiator

(Manufactured by BASF, Irgacure184)

‧Polysiloxane leveling agent: 0.3 parts of polyether modified polysiloxane

(Manufactured by Shin-Etsu Silicones Co., Ltd., KF6004)

‧150 parts of solvent (toluene)

[Comparative Example B5]

The uneven layer coating liquid B1 of Example B1 was changed to the uneven layer coating liquid B7 of the following formulation, and the film thickness of the uneven layer was 4 μm, except that the optical sheet was obtained in the same manner as in Example B1.

<Concavo-convex layer coating liquid B7>

‧100 parts of neopentylerythritol tetraacrylate

(Manufactured by Kyoeisha Chemical Co., Ltd., Light acrylate PE-4A)

‧Amorphous silica particles (hydrophobic treatment: silane coupling agent) 2 parts

(Manufactured by Fuji Silesia Chemical Co., Ltd., with an average agglomerated particle size of 3μm)

‧3 parts of photopolymerization initiator

(Manufactured by BASF, Irgacure184)

‧Polysiloxane leveling agent: 0.2 part of polyether modified polysiloxane

(Manufactured by Shin-Etsu Silicones Co., Ltd., X-22-2516)

‧150 parts of solvent (toluene)

According to the results in Table 3, it can be seen that the optical sheet of Example B1 can impart outdoor anti-glare properties and can improve the operability. In addition, the resolution is also good.

B3. Production of touch panel

On the transparent substrate side of the optical sheets of Examples B1, B2 and Comparative Examples B1 to B5, an ITO conductive film with a thickness of 20 nm was formed by a sputtering method to form an upper electrode plate. Then, an ITO conductive film with a thickness of about 20 nm was formed on one surface of a strengthened glass plate with a thickness of 1 mm by a sputtering method to form a lower electrode plate. Then, by the screen printing method, the ionizing radiation curable resin (Dot Cure TR5903: Sun Ink Co., Ltd.) as a coating liquid for spacers was printed in dots on the conductive film surface of the lower electrode plate, and then used The high-pressure mercury lamp irradiates ultraviolet rays, and spacers with a diameter of 50 μm and a height of 8 μm are arranged at intervals of 1 mm.

Then, the upper electrode plate and the lower electrode plate were arranged such that the conductive films were opposed to each other, and the edges were bonded with a double-sided tape having a thickness of 30 μm and a width of 3 mm to produce Examples B1, B2, and Comparative Examples B1~ B5 resistive film type touch panel.

The resistive film type touch panels of Examples B1 and B2 have outdoor anti-glare properties, and have good operability and resolution.

B4. Production of display device (1)

The optical sheets of Examples B1, B2, and Comparative Examples B1 to B5, and the surface glass plate of a commercially available ultra-high-definition liquid crystal display device (4.7 inches, pixel density about 320ppi) were bonded through a transparent adhesive to produce and implement The display devices (1) of Examples B1, B2 and Comparative Examples B1 to B5. Furthermore, when bonding, the uneven surface of the optical sheet is directed to the side opposite to the display element.

The display device (1) obtained by visual evaluation was used to evaluate the presence or absence of glare. As a result, with respect to the display devices (1) of Examples B1 and B2, glare was suppressed, the reflection of external light was less, and the visibility was good. In addition, the display device (1) of the embodiment B1 will not impair the resolution of the ultra-high-definition image.

B5. Production of display device (2)

The base material of the optical sheets of Examples B1, B2 and Comparative Examples B1 to B5 was changed to a polyethylene terephthalate film with a thickness of 50 μm (retardation value 2,500 nm). Otherwise, the same as those of Examples B1, B2 and In the same manner as in Comparative Examples B1 to B5, optical sheets of Examples B3 and B4 and Comparative Examples B6 to B10 were produced. The physical property values in Table 3 of the optical sheets of Examples B3, B4 and Comparative Examples B6 to B10 are approximately the same as those of Examples B1 and B2 and Comparative Examples B1 to B5.

Combining the optical sheets of Examples B3, B4 and Comparative Examples B6 to B10, and the organic EL display element of the three-color independent method with a microcavity structure, a commercially available organic EL display device with a polarizing element (based on the CIE-xy chromaticity diagram) Coverage of BT.2020: 77%) surface glass plates were pasted through a transparent adhesive to fabricate display devices (2) of Examples B3, B4 and Comparative Examples B6 to B10. Furthermore, when bonding, the uneven surface of the optical sheet is directed to the side opposite to the display element.

[Evaluation of Display Device (2)]

<The uneven color of the gradient>

The screen of the display device (2) is displayed in white or almost white. Observe the picture visually from various angles through polarized sunglasses to evaluate whether the uneven color of the gradual color can be recognized. Twenty people evaluated with the following evaluation criteria: 2 points are set for those who cannot recognize the uneven color of the gradation, and 1 points for those who cannot recognize the uneven color of the gradation but do not hinder the image quality. Set the color unevenness of the gradation color to be clearly recognized, which will seriously hinder the image quality as 0 points. The average score of 20 people is 1.7 or higher as A, 1.4 or higher and less than 1.7 as B, 1.0 or more and less than 1.4 as C, and 1.0 as less than For D. The results are shown in Table 4.

The display elements constituting the display device (2) have a very wide color gamut, which is easy to produce gradation Those with uneven color. However, since the display device (2) of Example B3 has a large Ra and a moderately random uneven shape, the color unevenness of the gradation color is almost completely unrecognizable.

1‧‧‧Resistive film touch panel

11‧‧‧Transparent substrate

12‧‧‧Transparent conductive film

13‧‧‧Spacer

Claims (9)

A touch panel with irregularities on the surface of the operator side, and the irregularities satisfy the following conditions (B1) and (B2). Condition (B1): A sapphire squeegee with a tip radius of 0.3mm is vertically in contact with the irregularities , Apply a vertical load Tg to the squeegee needle, and at the same time make the squeegee needle perform a round trip with a single pass length of 10mm at a speed of 5mm/s, measure the static friction coefficient μs and the dynamic friction coefficient μk acting on the squeegee needle at this time; Take the ratio of the static friction coefficient μs to the dynamic friction coefficient μk (μs/μk) as the vertical axis, and draw the vertical load Tg as the horizontal axis. The curve in the range of the vertical load 100~1000g is maximized When the Kodaira method is approximated by a straight line, the slope of the straight line is negative; condition (B2): Regarding the unevenness, the arithmetic average roughness (Ra _2.5 ) of JIS B0601: 1994 when the cut-off value is set to 2.5 mm is 0.10 μm Above 0.60μm or less. For example, the first touch panel in the scope of the patent application, in which, regarding the unevenness, the ten-point average roughness (Rz _0.8 ) of JIS B0601: 1994 when the cut-off value is set to 0.8mm and when the cut-off value is set to 2.5mm The JIS B0601: 1994 ten-point average roughness (Rz _2.5 ) satisfies the following condition (B3), Rz _0.8 /(Rz _2.5 -Rz _0.8 )≦3.2 (B3). For example, the touch panel of item 1 or 2 of the scope of patent application, in which, with regard to the unevenness, the maximum height of JIS B0601: 1994 when the cut-off value is set to 2.5mm (Ry _2.5 ) and the cut-off value is set to 2.5mm JIS B0601: 1994 ten-point average roughness (Rz _2.5 ) satisfies the following condition (B6), Ry _2.5 /Rz _2.5 ≦1.5 (B6). For example, the touch panel of item 3 of the scope of patent application, in which, regarding the unevenness, the average inclination angle of the unevenness (θ a _2.5 ) when the cut-off value is set to 2.5 mm and the Ry _2.5 /Rz _2.5 satisfy the following conditions (B7 ), 0.8≦θ a _2.5 /(Ry _2.5 /Rz _2.5 )≦5.0 (B7). For example, the touch panel of item 1 or 2 of the scope of patent application, wherein the concavities and convexities are arranged on one surface of the optical sheet. For example, the touch panel of item 5 of the scope of patent application, wherein the optical sheet has a transparent substrate with a retardation value of more than 0 nm and less than 3,000 nm. A display device that has unevenness on the outermost surface of the exit surface side of the display element, and the unevenness satisfies the following conditions (B1) and (B2). Condition (B1): a sapphire needle with a tip radius of 0.3mm is vertically in contact Apply the vertical load Tg to the squeegee needle, and at the same time make the squeegee needle go back and forth with a single pass length of 10mm at a speed of 5mm/sec, measure the static friction coefficient μs and the dynamic friction coefficient acting on the squeegee needle at this time μk; in the graph drawn by taking the ratio of the static friction coefficient μs to the dynamic friction coefficient μk (μs/μk) as the vertical axis and the vertical load Tg as the horizontal axis, the curve in the range of the vertical load 100~1000g When approximating a straight line by the least square method, the slope of the straight line is negative; Condition (B2): Regarding the unevenness, the cut-off value is set to 2.5mm, JIS B0601: 1994 arithmetic average roughness (Ra _2.5 ) It is 0.10 μm or more and 0.60 μm or less. An optical sheet having unevenness on one surface that satisfies the following conditions (B1) and (B2). Condition (B1): a sapphire needle with a tip radius of 0.3 mm is vertically in contact with the unevenness, and the needle Apply a vertical load Tg, and at the same time make the scraping needle perform a round trip with a single pass length of 10mm at a speed of 5mm/sec. At this time, measure the static friction coefficient μs and the dynamic friction coefficient μk acting on the scraping needle; the static friction coefficient μs The ratio (μs/μk) to the coefficient of dynamic friction μk is set on the vertical axis, and the vertical load Tg is set on the horizontal axis to draw the graph. The curve in the range of the vertical load 100~1000g is drawn by the least square method When a straight line is approximated, the slope of the straight line is negative; Condition (B2): Regarding the unevenness, the arithmetic average roughness (Ra _2.5 ) of JIS B0601: 1994 when the cut-off value is set to 2.5 mm is 0.10 μm or more and 0.60 μm the following. A method for screening optical sheets, which selects one surface with unevenness, and the unevenness satisfies the following conditions (B1) and (B2) as the optical sheet located on the uppermost part of the touch panel. Condition (B1): make the tip radius 0.3 A sapphire needle made of mm sapphire is vertically in contact with the unevenness, a vertical load Tg is applied to the needle, and at the same time, the needle is made to make a round trip of 10mm in a single pass at a speed of 5mm/sec. The measurement acts on the The static friction coefficient μs and the dynamic friction coefficient μk of the scraper; in the graph drawn with the ratio of the static friction coefficient μs to the dynamic friction coefficient μk (μs/μk) as the vertical axis and the vertical load Tg as the horizontal axis, the When the curve in the range of vertical load 100~1000g is approximated by a straight line by the least square method, the slope of the straight line is negative; condition (B2): Regarding the unevenness, JIS B0601 when the cut-off value is set to 2.5mm: The arithmetic average roughness (Ra _2.5 ) of 1994 is 0.10 μm or more and 0.60 μm or less.

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