TWI787634B - Writing sheet for touch panel pen, touch panel, touch panel system and display device, and selection method for writing sheet for touch panel pen - Google Patents

Abstract

The invention provides a writing sheet for a touch panel pen which can improve the writing feeling. The writing sheet for a touch panel pen of the present invention is the following writing sheet for a touch panel pen (A), which has a maximum height roughness Rz of _0.8 in JIS B0601:2001 with a cutoff value of 0.8 mm and The maximum valley depth Rv _0.8 of the roughness curve and the average interval of local peaks S _2.5 in JIS B0601: 1994 with a cut-off value of 2.5 mm satisfy the following conditions (A1) and (A2). 0.35≦Rv _0.8 ／Rz _0.8 ≦0.60 (A1) 0.05 mm≦S _2.5 ≦0.30 mm (A2) <Touch panel pen (A)> The structure of the touch panel pen that will constitute the tip and shaft of the touch panel pen When the apparent Young's modulus of the body is set to E, the diameter of the nib is set to D, and the arithmetic mean height of the profile curve in the unit measurement interval (0.5 mm) of the nib is set to Pa, the following formula (i) The derived X is below 500 MN/m. X (MN/m) = [E×D×D]/Pa (i)

Description

Writing sheet for touch panel pen, touch panel, touch panel system and display device, and selection method for writing sheet for touch panel pen

The invention relates to a writing sheet for a touch panel pen, a touch panel, a touch panel system and a display device, and a method for selecting a writing sheet for a touch panel pen.

In recent years, touch panels have also begun to be mounted on many mobile information terminals, and the traffic has increased. A surface protection sheet may be attached to the surface of the touch panel for various purposes.

With regard to the resistive film type touch panel which is the current mainstream, since operations such as repeated touch with a finger or a pen are performed, a high degree of scratch resistance is required for the surface protection sheet. On the other hand, for the surface protection sheet of the capacitive touch panel which is the mainstream at present, slidability at the time of operation with a finger is required. The reason is: because the previous resistive film type cannot detect multiple parts at the same time, there is no situation of moving the finger on the screen, but the electrostatic capacitive touch panel can detect multiple parts at the same time, and the operation of moving the finger on the screen is relatively difficult. many. In addition, for resistive film type and electrostatic capacitive touch panels, the surface protection sheet for touch panels is required to have the following performance: to prevent fingerprints from adhering to finger operations, or to easily wipe off attached fingerprints.

Patent documents 1-2 are proposed as a surface protection sheet for touch panels as mentioned above, for example. [Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2015-114939 [Patent Document 2] Japanese Patent Laid-Open No. 2014-109712

[Problem to be Solved by the Invention]

Since the capacitive touch panel needs to measure the change of the electrostatic capacitance and identify the touched part, the contact object needs a certain degree of conductivity. Therefore, at the beginning of the appearance of the electrostatic capacitive touch panel, only the operability with fingers was studied, but the writing ability of drawing characters or pictures with a touch panel pen was not studied. Even in the resistive film type touch panel, touch is the main operation when using the touch panel pen, and the handwriting performance when drawing characters or pictures is not paid much attention to. However, in recent years, since a touch panel pen capable of writing input to an electrostatic capacitive touch panel or an electromagnetic induction touch panel has been proposed; and application software corresponding to text input or drawing using a touch panel pen has increased, so for The surface protection sheet for touch panel requires a good writing feeling with a touch panel pen. However, with regard to the surface protection sheets for touch panels of Patent Documents 1 to 2 proposed previously, no research has been conducted on the writing feeling with a touch panel pen.

The object of the present invention is to provide a writing sheet for a touch panel pen, a touch panel and a display device, and a method for selecting a writing sheet for a touch panel pen that can improve the writing feeling. [Technical means to solve the problem]

In order to solve the above problems, the present invention provides the following [1] to [14] writing sheets for touch panel pens, touch panels, touch panel systems and display devices, and methods for selecting writing sheets for touch panel pens.

[1] A writing sheet for a touch panel pen, which is the following writing sheet for a touch panel pen (A), which has a maximum height roughness of JIS B0601:2001 with a cutoff value of 0.8 mm Rz _0.8 , maximum valley depth Rv _0.8 of roughness curve, and JIS B0601:1994 average interval of local peaks S _2.5 with a cut-off value of 2.5 mm is a surface that satisfies the following conditions (A1) and (A2). 0.35≦Rv _0.8 ／Rz _0.8 ≦0.60 (A1) 0.05mm≦S _2.5 ≦0.30mm (A2) <Touch panel pen (A)> The structure of the touch panel pen that will constitute the tip and shaft of the touch panel pen When the apparent Young's modulus of the body is set to E, the diameter of the nib is set to D, and the arithmetic mean height of the profile curve in the unit measurement interval (0.5 mm) of the nib is set to Pa, the following formula (i) The derived X is below 500 MN/m. X(MN/m)=[E×D×D]/Pa (i) [2] A touch panel having a sheet on the surface as the writing sheet for a touch panel pen described in [1] above The surface on the side satisfying the above conditions (A1) and (A2) is disposed so as to face the surface of the touch panel. [3] A display device including a touch panel, wherein the touch panel is the touch panel described in [2] above. [4] A method for selecting a writing sheet for a touch panel pen, which selects the maximum height roughness Rz _0.8 of JIS B0601: 2001 with a cutoff value of 0.8 mm and the maximum valley depth Rv _0.8 of the roughness curve, and a cutoff value of 2.5 mm The sheet whose surface satisfies the following conditions (A1) and (A2) according to JIS B0601:1994's average interval S _2.5 of local peaks is used as the following writing sheet for touch panel pen (A). 0.35≦Rv _0.8 ／Rz _0.8 ≦0.60 (A1) 0.05 mm≦S _2.5 ≦0.30 mm (A2) <Touch panel pen (A)> The structure of the touch panel pen that will constitute the tip and shaft of the touch panel pen When the apparent Young's modulus of the body is set to E, the diameter of the nib is set to D, and the arithmetic mean height of the profile curve in the unit measurement interval (0.5 mm) of the nib is set to Pa, the following formula (i) The derived X is below 500 MN/m. X (MN/m) = [E×D×D]/Pa (i)

[5] A writing sheet for a touch panel pen, which is the following writing sheet for a touch panel pen (B), which has a maximum height roughness Rz of _0.8 and a roughness of JIS B0601:2001 with a cutoff value of 0.8 mm The maximum mountain height Rp _0.8 of the degree curve, and the skewness Psk of the profile curve in the measurement interval 1 mm meet the following conditions (B1) and (B2) on the surface, and the haze (haze) of JIS K7136:2000 of the writing sheet ) satisfy the following condition (B3). 0.50<Rp _0.8 ／Rz _0.8 ≦0.75 (B1) 0.60≦Psk (B2) Haze of 5.0% or more (B3) When the apparent Young's modulus of the structure of the shaft is E, the diameter of the nib is D, and the arithmetic mean height of the profile curve in the unit measurement interval (0.5 mm) of the nib is Pa, the following X derived from formula (i) exceeds 500 MN/m. X(MN/m)=[E×D×D]/Pa (i) [6] A touch panel having a sheet on the surface, the writing sheet for a touch panel pen described in [1] as the sheet satisfies The surface on the side of the above conditions (B1) and (B2) is disposed so as to face the surface of the touch panel. [7] A display device including a touch panel, wherein the touch panel is the touch panel described in [6] above. [8] A method for selecting writing sheets for touch panel pens, selecting the maximum height roughness Rz _0.8 of JIS B0601: 2001 with a cut-off value of 0.8 mm and the maximum height Rp _0.8 of the roughness curve, and the measurement interval 1 mm The surface whose skewness Psk of the profile curve satisfies the following conditions (B1) and (B2), and the sheet whose haze of JIS K7136:2000 satisfies the following condition (B3) is used as the following touch panel pen (B) writing tablet. 0.50<Rp _0.8 ／Rz _0.8 ≦0.75 (B1) 0.60≦Psk (B2) Haze of 5.0% or more (B3) When the apparent Young's modulus of the structure of the shaft is E, the diameter of the nib is D, and the arithmetic mean height of the profile curve in the unit measurement interval (0.5 mm) of the nib is Pa, the following X derived from formula (i) exceeds 500 MN/m. X (MN/m) = [E×D×D]/Pa (i)

[9] A method for selecting a writing sheet for a touch panel pen, which selects a writing sheet for a touch panel pen that satisfies the following condition (C1). ＜Condition (C1)＞ Fix the touch panel pen in contact with the surface of the writing sheet for the touch panel pen at an angle of 60 degrees, apply a vertical load of 100 gf to the touch panel pen, and scan 40 mm at a speed of 14 mm/sec in one pass Assuming that the kinetic friction coefficient acting in the scanning direction of the touch panel pen at this time is μk and the static friction coefficient is μs, μk/μs is not less than 0.30 and not more than 0.58. [10] The method for selecting a writing sheet for a touch panel pen as described in claim 12 of the patent application, wherein the aforementioned μk satisfying the following condition (C2) is selected as the writing sheet for a touch panel pen. ＜Condition (C2)＞ 0.06≦μk≦0.30 [11] A writing sheet for a touch panel pen having a surface satisfying the following condition (C1). ＜Condition (C1)＞ Fix the touch panel pen in contact with the surface of the writing sheet for the touch panel pen at an angle of 60 degrees, apply a vertical load of 100 gf to the touch panel pen, and scan 40 mm at a speed of 14 mm/sec in one pass Assuming that the kinetic friction coefficient acting in the scanning direction of the touch panel pen at this time is μk and the static friction coefficient is μs, μk/μs is not less than 0.30 and not more than 0.58. [12] A touch panel having a sheet on the surface, wherein the surface of the writing sheet for a touch panel pen described in [11] above as the sheet satisfies the above-mentioned condition (C1) so as to face the surface of the touch panel . [13] A touch panel system comprising a touch panel having a writing sheet for a touch panel pen on its surface and a touch panel pen, the touch panel system satisfying the following condition (C1). ＜Condition (C1)＞ Fix the touch panel pen in contact with the surface of the writing sheet for the touch panel pen at an angle of 60 degrees, apply a vertical load of 100 gf to the touch panel pen, and scan 40 mm at a speed of 14 mm/sec in one pass Assuming that the kinetic friction coefficient acting in the scanning direction of the touch panel pen at this time is μk and the static friction coefficient is μs, μk/μs is not less than 0.30 and not more than 0.58. [14] A display device including a touch panel, wherein the touch panel is the touch panel described in the above [12]. [Effect of Invention]

The writing sheet for touch panel pen, touch panel, touch panel system and display device of the present invention can improve writing feeling. Also, the method for selecting a writing sheet for a touch panel pen according to the present invention can select a writing sheet with a good writing feeling for a specific touch panel pen, and can write efficiently without performing a writing test with a touch panel pen Film product design, quality management.

Below, for the writing sheet for touch panel pen, touch panel, touch panel system and display device of the present invention, and the selection method for writing sheet for touch panel pen, embodiment A, embodiment B and embodiment C are used Take this as an example. <Embodiment A> [Writing sheet for touch panel pen] The writing sheet for touch panel pen of Embodiment A is the following writing sheet for touch panel pen (A), and the writing sheet has a cutoff value of 0.8 mm. The maximum height roughness Rz _0.8 of JIS B0601: 2001 and the maximum valley depth Rv _0.8 of the roughness curve, and the average interval of local peaks S _2.5 of JIS B0601: 1994 with a cut-off value of 2.5 mm meet the following conditions (A1) and (A2) the surface. 0.35≦Rv _0.8 ／Rz _0.8 ≦0.60 (A1) 0.05 mm≦S _2.5 ≦0.30 mm (A2) <Touch panel pen (A)> This touch panel pen is attached between the tip and shaft of the touch panel pen When the apparent Young's modulus of the structure is E, the diameter of the nib is D, and the arithmetic mean height of the profile curve in the unit measurement interval (0.5 mm) of the nib is Pa, the following formula (i ) derived X is below 500 MN/m. X (MN/m) = [E×D×D]/Pa (i) Furthermore, the unit of Young’s modulus E is “N/m ² ”, the unit of the diameter D of the nib is “m”, and the arithmetic mean The unit of height Pa is "m". Also, "M" means "mega (10 ⁶ )".

Fig. 1 is a cross-sectional view showing an embodiment of a writing sheet 10 for a touch panel pen according to Embodiment A. The writing sheet 10 for a touch panel pen in FIG. 1 has a resin layer 2 on one surface of a plastic film 1 . The writing sheet 10 for a touch panel pen in FIG. 2 is composed of a single layer of the resin layer 2 . The writing sheet for a touch panel pen of Embodiment A may satisfy the conditions (A1) and (A2) on one surface, or satisfy the conditions (A1) and (A2) on both surfaces. The writing sheet for a touch panel pen of Embodiment A may be in the form of a single sheet, or may be in the form of a roll in which a long sheet is wound into a roll. Hereinafter, the writing sheet for a touch panel pen may be referred to as a "writing sheet". In addition, below, the surface which satisfies the conditions (A1) and (A2) may be called a "writing surface".

＜Writing surface＞ The writing sheet for a touch panel pen of Embodiment A is one in which at least one surface satisfies the conditions (A1) and (A2). In embodiment A, condition (A1) and condition (A2) use different cut-off values. The reasons for using two cutoff values (0.8 mm and 2.5 mm) are explained below.

The cutoff 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 is a value indicating the fineness of a filter that cuts off moiré components (low frequency components) from the profile curve. If the cutoff value is larger, the filter is thinner, so the larger ripple components of the ripple components are cut off, but the smaller ripple components are not cut off. On the other hand, if the cutoff value is small, the filter is denser, so the moiré component is basically cut off. That is, when the cutoff value is small, the influence on the unevenness of the high-frequency component becomes stronger, and when the cutoff value is large, the influence on the unevenness of the low-frequency component becomes stronger. In JIS B0633 referred to in JIS B0601, a specific cutoff value (standard length) is used based on the value of the arithmetic mean roughness Ra. That is, in JIS, a single cut-off value is used as a principle for any sample, and it is not assumed that multiple cut-off values are used.

The inventors of the present invention have diligently studied the relationship with the writing feeling of the writing sheet. It was found that the physical properties of the nib will seriously affect the writing feeling. The so-called physical properties of the pen tip here are based on the hardness of the pen tip and shaft structure of the touch panel pen (Young's modulus E), the diameter D of the pen tip, and the roughness of the pen tip (the arithmetic mean height Pa of the section curve of the pen tip) , "X" calculated from the above formula (i). The case where X seriously affects the writing feeling can be explained as follows. First, Young's modulus E is a basic physical property indicating the ease with which a pen tip deforms under load, and there is a tendency that the smaller the Young's modulus E, the easier the pen tip deforms under load. Then, the square of the diameter D indicates the degree of load distribution, and there is a tendency that the smaller the square of the diameter D is, the harder it is to distribute the load, and the easier the pen tip is to deform due to the load. That is, it shows that the smaller the "Young's modulus E×diameter D×diameter D", the easier the nib is deformed, and the easier it is for the nib to come into contact with the writing sheet. Secondly, the arithmetic mean height Pa of the section curve of the nib indicates the degree to which the nib touches the writing sheet. Specifically, the larger Pa is, the more the point contact between the pen point and the writing sheet becomes, and the smaller the contact area between the pen point and the writing sheet becomes. Therefore, it means that the smaller the value of "X" calculated from [Young's modulus E×diameter D×diameter D]÷Pa, the easier the nib and the writing sheet are to adhere closely, which will have a significant impact on the writing feeling.

Furthermore, the inventors of the present invention found that when the X value is small, the following behaviors are exhibited at the time of writing. First, when the value of X is small, the nib deforms to follow the surface shape of the writing sheet when the pen touches the writing sheet and the writing starts, and the contact between the pen tip and the writing film changes in a small area. close. Therefore, the unevenness of the high-frequency component has a greater influence on the frictional resistance at the stage of starting writing. Then, at the stage after starting to write, by moving along with the increase in writing speed, with the help of the unevenness of the low-frequency component of the film, the frequency of close contact between the pen tip and the film in a small area is reduced, so that the unevenness of the high-frequency component has an effect on the friction The influence of the resistance is reduced. On the other hand, the influence of the unevenness of the low-frequency component with a large amount of unevenness on the frictional resistance becomes greater. Then, the present inventors conducted further studies based on the above-mentioned behavior, and found that by designing the surface shape using two cutoff values, the writing feeling from the start of writing to the end of writing can be improved. Furthermore, when writing characters or drawing graphics, most of them stop writing for a moment and then start writing (for example, when changing the writing direction, they usually stop writing for a moment; and when moving the writing position, they also stop writing for a moment). The present inventors also regard this as "starting writing" just after starting writing again.

Condition (A1) requires that the maximum height roughness Rz _0.8 of JIS B0601: 2001 and the maximum valley depth Rv _0.8 of the roughness curve satisfy 0.35≦Rv _0.8 / Rz _0.8 ≦0.60 when the cut-off value is set to 0.8 mm. The cut-off value of condition (A1) is 0.8 mm. The condition (A1) is a parameter that shows unevenness of high-frequency components and mainly affects the writing feeling at the beginning of writing.

Rv _0.8 /Rz _0.8 in condition (A1) represents the ratio of the valleys and valleys of the high-frequency components. The nib is in close contact with the concave-convex mountain, and on the other hand, it is difficult for the nib to enter the concave-convex valley, so the valley suppresses the peeling force (frictional resistance) of the nib when starting to write. Therefore, by setting Rv _0.8 /Rz _0.8 within the above range, the peeling force (frictional resistance) of the pen point at the start of writing becomes appropriate, and the writing feeling at the start of writing can be improved. Moreover, by making _Rv0.8 / _Rz0.8 into the said range, a pen can be easily made to stand still on the surface of a writing sheet. On the other hand, when Rv _0.8 /Rz _0.8 is less than 0.35, the proportion of valleys is too small, so there is a feeling of being stuck, and the writing feeling at the beginning of writing cannot be improved. Also, when Rv _0.8 /Rz _0.8 exceeds 0.60, the ratio of the valleys is too large, so there is a smooth feeling, but the writing feeling at the beginning of writing cannot be improved, and it is difficult to keep the pen still. The condition (A1) preferably satisfies 0.37≦Rv _0.8 /Rz _0.8 ≦0.55, more preferably satisfies 0.40≦Rv _0.8 /Rz _0.8 ≦0.50. In addition, Rv _0.8 and Rz _0.8 used as a reference of the calculation condition (A1) were made into the average value at the time of each measuring 1 time about 20 samples. In addition, the following S _2.5 , Pp, Pv, Pa, Ra, transmission clarity, and haze were also set as average values when each of 20 samples was measured once.

Condition (A2) requires that when the cut-off value is set to 2.5 mm, the average interval S _2.5 of local peaks in JIS B0601: 1994 satisfies 0.05 mm≦S _2.5 ≦0.30 mm. The cut-off value for condition (A2) is 2.5 mm. The condition (A2) is a parameter indicating the unevenness of the low-frequency component and mainly affecting the writing feeling after starting to write.

S _2.5 of condition (A2) means the average interval of local peaks of low frequency components. After starting to write, the nib moves while touching the local peak. Therefore, S _2.5 will affect the feeling after starting to write. Therefore, by setting S _2.5 within the above range, the frictional resistance after the start of writing becomes appropriate, and the writing feeling after the start of writing can be improved. When the S _2.5 is less than 0.05 mm, there are too many peaks locally, so there is a feeling of being stuck, and the writing feeling after starting to write cannot be improved. Also, when S _2.5 exceeds 0.30 mm, compared with the contact area of the nib, there are too few local peaks, and the feeling is smooth, and the writing feeling after starting to write cannot be improved. Condition (A2) preferably satisfies 0.05 mm≦S _2.5 ≦0.25 mm, more preferably satisfies 0.05 mm≦S _2.5 ≦0.15 mm. Furthermore, setting S _2.5 to be 0.05 mm or more is also related to the suppression of the decrease in the resolution of the display element. In particular, it is preferable in suppressing the reduction of the resolution of ultra-high-definition display elements with a pixel density of 300 ppi or more.

Also, in the writing sheet of embodiment A, it is preferable to set the unit measurement interval as 1 mm, set the maximum value of the mountain height of the profile curve in the unit measurement interval to Pp, and set the maximum value of the valley depth of the profile curve in the unit measurement interval to Pv, the sum of Pp and Pv is set as the maximum profile height Pt of the profile curve in the unit measurement interval, and when the average value of Pt in the 5 measurement intervals is set as Ptm, the Ptm of the writing surface satisfies the following conditions (A3) . 0.01 μm≦Ptm≦1.00 μm （A3） The so-called maximum value Pp of the mountain height of the profile curve in the unit measurement interval refers to the part above the elevation mean line of the unit measurement interval defined as a mountain, indicating the height of the highest mountain. Furthermore, Pp is different from the maximum height Rp of the roughness curve of JIS B0601:2001, which is the basis for calculating parameters, in that Pp is the profile curve and Rp is the roughness curve. The so-called maximum value Pv of the valley depth of the profile curve in the unit measurement interval refers to the part located below the elevation average line of the unit measurement interval as the valley, indicating the depth of the deepest valley. Furthermore, Pv is different from the maximum valley depth Rv of the roughness curve of JIS B0601:2001 as the basis for calculating parameters in that Pv is the profile curve and Rv is the roughness curve.

As mentioned above, the high-frequency unevenness has a great influence on the writing feeling at the beginning of writing, and the low-frequency unevenness has a great influence on the writing feeling after the beginning of writing. However, the sum of the high-frequency unevenness and the low-frequency unevenness also has some influence on the writing feeling at the beginning of writing and the writing feeling after starting writing. The condition (A3) means that the level difference of the unevenness (cut-off value 0) obtained by adding the high-frequency unevenness and the low-frequency unevenness will not be too small and will not be too large. Therefore, by making condition (A3) into the said range, the writing feeling from the start of writing to the end of writing can be made more favorable. The condition (A3) preferably satisfies 0.10 μm≦Ptm≦0.85 μm, and more preferably satisfies 0.35 μm≦Ptm≦0.75 μm.

Moreover, it is preferable that the writing surface of the writing sheet of Embodiment A satisfies the following condition (A4) at the arithmetic mean roughness Ra _0.8 of JIS B0601:2001 when the cut-off value is made into 0.8 mm. 0.01 μm≦Ra _0.8 ≦0.50 μm (A4) By setting Ra _0.8 in the above range, the writing feeling can be improved, and the resolution reduction of the display device can be suppressed by the writing sheet. In particular, it is preferable in suppressing the reduction of the resolution of ultra-high-definition display elements with a pixel density of 300 ppi or more. The condition (A4) is more preferably 0.03 μm≦Ra _0.8 ≦0.30 μm, further preferably 0.05 μm≦Ra _0.8 ≦0.15 μm.

Furthermore, in the writing sheet of Embodiment A, it is preferable to fix the touch panel pen (A) in the state of contacting the writing surface at an angle of 60 degrees, and apply a vertical load of 100 gf to the touch panel pen (A) on one side. One side scans a length of 40 mm in a single pass at a speed of 14 mm/s. When the kinetic friction coefficient acting on the scanning direction of the touch panel pen (A) at this time is set to μk, and the static friction coefficient is set to μs, it satisfies 0.30≦μk/ The relationship between μs≦0.58. Furthermore, in Embodiment A, the kinetic friction coefficient μk means the average value of the kinetic friction coefficients at all measurement times. The coefficient of static friction is assumed to be the peak value of the initial friction force that becomes higher than the coefficient of dynamic friction as the measurement time elapses from the friction force of 0. The measurement interval of the coefficient of friction is preferably set at 0.02 seconds. When writing characters or drawing graphics, most people stop writing for a moment and then start writing (for example, when changing the writing direction, they usually stop writing for a moment. Also, when moving the writing position, they also stop writing for a moment). When starting writing after stopping writing for a while as above, it is easy to be affected by the difference between the coefficient of static friction and the coefficient of dynamic friction, but by setting μk/μs in the above range, it is possible to start writing after stopping writing for a while Realize imaginary writing (for example, can change the direction of writing to the expected direction). In order to satisfy the relationship of 0.30≦μk/μs≦0.58, the above conditions (A1) and (A2) are preferably satisfied, the above conditions (A1) to (A3) are more preferably satisfied, and the above conditions (A1) to (A4) are preferably satisfied ). Moreover, in order to make the above effect more favorable, it is more preferable that μk/μs satisfies the relationship of 0.30≦μk/μs≦0.44. μk/μs is a value obtained by calculating the μk/μs of each sample by measuring once for each of the 20 samples, and averaging the μk/μs of the 20 samples.

Furthermore, even when the touch panel pen is fixed while touching the writing surface at an angle other than 60 degrees (for example, any angle in the range of 30 to 75 degrees), μk/μs is preferably within the above range. Also, even when the scanning speed is set to a speed other than 14 mm/sec (for example, any speed in the range of 0.1 to 100 mm/sec), it is preferable that μk/μs is in the above-mentioned range.

Also, from the viewpoint of obtaining an appropriate sense of resistance without excessive smoothness, μk and μs are preferably in the following ranges. μk is preferably from 0.06 to 0.30, more preferably from 0.08 to 0.28. μs is preferably from 0.15 to 0.95, more preferably from 0.20 to 0.60.

Fig. 7 is a schematic diagram illustrating a method of measuring μk and μs. In FIG. 7 , the touch panel pen 200 is fixed by the holder 84 in a state of contacting the writing sheet 10 . In addition, a base 85 on which the weight 83 is placed is attached to the upper portion of the holder 84 . A weight 83 is placed on the base 85, and a vertical load is applied to the touch panel pen by this weight. The writing sheet 10 is fixed on the movable platform 82 . When measuring the friction coefficient, move the movable table 82 to the obtuse angle side (the left side of Fig. 7 ) of the angle formed by the movable table and the touch panel pen at a specific speed while the touch panel pen is fixed in the above-mentioned manner. scanning. As a measurable device shown in FIG. 7 , HEIDON-14DR manufactured by Shinto Scientific Co., Ltd. is exemplified.

The apparent Young's modulus E of the pen tip and shaft structure of the touch panel pen can be calculated from the variation in the compression direction of the tensile tester and the load characteristics. Specifically, as shown in Figure 5, the axial length of the part 10 cm away from the pen tip fixed from both sides by the clamp 300 can be set as L, and the deformation amount when a vertical load of 5 gf is applied to the pen axis direction through the clamp 300 The difference ΔL from the deformation amount when a vertical load of 100 gf is applied is defined as displacement, and the load difference of 95 gf is defined as ΔF, and the cross-sectional area S obtained from the diameter of the pen tip is calculated by the following formula (ii). The object pressed against the touch panel pen 200 is a stainless steel plate 400 with a thickness of 3 mm or more. Furthermore, when the pen is unstable when pressed against the pen, it is only necessary to provide a concave portion for stabilizing the pen on the surface of the board, and make the pen touch the position of the concave portion. Regarding the environment when measuring Young's modulus E, the temperature is set at 23°C±5°C, and the humidity is set at 50%±10%. Also, before starting the measurement of Young's modulus E, place the touch panel pen in an environment of 23°C±5°C and humidity of 50%±10% for more than 10 minutes. σ (stress) = ΔF/S ε (strain) = ΔL/L E＝σ／ε （ii）

The diameter D of the pen tip is calculated based on a photograph taken of the touch panel pen from the side perpendicular to the pen axis. FIG. 6 shows the appearance of the touch panel pen when the touch panel pen is photographed from the side perpendicular to the direction of the pen axis with a dotted line. As shown in FIG. 6( a ), when circles that pass through the vertices of the picture and do not protrude from the picture are overlapped with each other, the diameter of the largest circle is set as the diameter D of the pen tip. However, if the photograph has a slope as shown in Figure 6(b), and the angle formed between the slope and the pen axis is 40-90 degrees, then the circle can also be stretched out to overlap the slope.

再者，Pa與JIS B0601：2001之算術平均粗糙度Ra係算出參數之基準於Pa為剖面曲線，Ra為粗糙度曲線之方面不同。The arithmetic mean height Pa of the profile curve in the unit measurement interval (0.5 mm) of the pen tip can be calculated by the following method: use a digital microscope to take pictures of the shape of the pen tip, and simulate the outline of the captured pen tip as a profile curve, and in the profile curve In the direction of the average line, only the length L of the unit measurement interval (0.5 mm) is extracted, and the absolute value of the deviation from the average line of the extracted part to the measurement curve is summed up and averaged. Specifically, Pa can be calculated from the following formula (iii). When the pen tip has curvature, it is enough to calculate Pa after correcting the curved surface to a straight line. Furthermore, the middle point of the unit measurement interval (0.5 mm) is preferably consistent with the center of the pen tip. As a digital microscope, for example, VHX-5000 or the like, which is a product name of Enns Corporation, can be used. [number 1]

Furthermore, Pa and the arithmetic mean roughness Ra of JIS B0601:2001 are different in that Pa is the profile curve and Ra is the roughness curve.

In addition, the writing sheet of embodiment A is better for the clearness of the transmitted image when the width of the optical frequency comb of the image resolution measuring instrument measured in accordance with JIS K7374:2007 is 0.125 mm, 0.5 mm, 1.0 mm and 2.0 mm. When the degree is set to C _0.125 , C _0.5 , C _1.0 and C _2.0 , the sum C _s of C _0.125 , C _0.5 , C _1.0 and C _2.0 is 250% or more, more preferably 270% or more, and more preferably 280% or more . By setting C _s to 250% or more, it is possible to suppress the reduction in the resolution of the display element by the writing sheet. In particular, it is preferable in suppressing the reduction of the resolution of ultra-high-definition display elements with a pixel density of 300 ppi or more. The upper limit of C _s is not particularly limited, but is about 399%.

In addition, the writing sheet of Embodiment A preferably has a haze of JIS K7136:2000 of less than 5.0%, more preferably 3.0% or less, and still more preferably 1.0% or less. By making the haze 5.0% or less, the resolution fall of a display element can be suppressed by a writing sheet. In particular, it is preferable in suppressing the reduction of the resolution of ultra-high-definition display elements with a pixel density of 300 ppi or more. The lower limit of the haze is not particularly limited, but is preferably at least 0.1%, more preferably at least 0.2%. In addition, when measuring transmitted image clarity and haze, light was incident from the surface of the writing sheet opposite to the writing surface. When both sides of the writing sheet satisfy the above-mentioned conditions (A1) and (A2), the light-incident side can be either side.

＜The overall composition of the writing sheet＞ The composition of the writing sheet for a touch panel pen of Embodiment A is not particularly limited as long as at least one surface satisfies the conditions (A1) and (A2). For example, as the composition of the writing sheet 10 for a touch panel pen of Embodiment A, it can be enumerated that it has a resin layer 2 as shown in FIGS. 1 and 2 , and one surface of the resin layer 2 satisfies the conditions (A1) and (A2). By. Furthermore, although not shown in the figure, there may be other layers other than the resin layer or the plastic film, and the surface of the other layer satisfies the conditions (A1) and (A2). As another layer, an antistatic layer, an antifouling layer, etc. are mentioned. Moreover, although not shown in figure, the resin layer may consist of 2 or more layers.

The surface (writing surface) that satisfies the conditions (A1) and (A2) can be formed by (a) physical or chemical treatment such as embossing, sandblasting, etching, (b) molding using a mold, (c) coating, etc. Among these methods, molding using a mold (b) is preferable from the viewpoint of surface shape reproducibility, and coating (c) is preferable from the viewpoint of productivity and compatibility with various varieties.

Molding using a mold can be formed by making a mold having a shape complementary to a shape satisfying the conditions (A1) and (A2), pouring the material for forming the resin layer into the mold, and taking it out from the mold. Here, if the material constituting the resin layer is used as the material, the material is poured into the mold, the plastic film is superimposed, and the resin layer is taken out from the mold together with the plastic film, the resin layer can be obtained on the plastic film, and The surface of the resin layer satisfies the requirements (A1) and (A2) of the writing sheet for a touch panel pen. In addition, the resin layer is directly taken out from the mold without using a plastic film, or the plastic film is taken out from the mold using a plastic film, and the plastic film is peeled off, thereby obtaining a single-layer resin layer, and the surface of the resin layer satisfies the condition (A1 ) and (A2) writing sheets for touch panel pens. When using a curable resin composition (thermosetting resin composition or ionizing radiation curable resin composition) as the material to be poured into the mold, it is preferable to harden the curable resin composition before taking it out from the mold.

Regarding the formation of the resin layer by coating, it is possible to apply a resin layer forming coating liquid containing resin components, particles and solvents to the plastic film by known coating methods such as gravure coating and rod coating. on, dried and hardened. In order to make the surface shape of the resin layer formed by coating satisfy the above conditions, it is preferable to form the first resin layer in which the film thickness, particle content, and average particle diameter of the particles are set to the following ranges, and in the second A second resin layer is formed on the first resin layer.

The film thickness of the first resin layer is preferably 1.5-10 μm, more preferably 2-8 μm, further preferably 4-7 μm. The film thicknesses of the first resin layer and the second resin layer described below can be measured at 20 locations, for example, from images of cross-sections captured by a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM). , and calculated based on the average of the values at 20 places. The acceleration voltage of TEM or STEM is preferably set at 10-30 kV, and the magnification is preferably set at 50,000-300,000 times.

As the particles of the first resin layer, any of organic particles and inorganic particles can be used. Examples of organic particles include polymethyl methacrylate, polyacrylic acid-styrene copolymer, melamine resin, polycarbonate, polystyrene, polyvinyl chloride, benzoguanamine-melamine-formaldehyde condensate, polysilicon Particles made of oxygen, fluorine-based resins, and polyester-based resins. Examples of the inorganic particles include particles made of silica, alumina, antimony, zirconia, and titania. Among these particles, organic particles are preferred from the viewpoint of ease of dispersion control. The content of the particles in the first resin layer is preferably 0.1-15% by mass, more preferably 0.2-12% by mass, and still more preferably 0.3-10% by mass of the total solid content forming the resin layer.

The average particle size of the particles in the first resin layer is preferably 0.2-8.0 μm, more preferably 0.3-7.0 μm, and still more preferably 0.5-5.0 μm. In the case of particle aggregation, it is preferable that the average particle diameter of the aggregated particles satisfies the above-mentioned range. The average particle diameter of the particles can be calculated by the following operations (1) to (3). (1) Use an optical microscope to take a transmission observation image of the writing sheet. The magnification is preferably 500 to 2000 times. (2) Select any 10 particles from the observation image, and calculate the particle diameter of each particle. The particle size is measured as the distance between straight lines in a combination of two straight lines where the distance between the two straight lines becomes the largest when the cross section of the particle is sandwiched between two arbitrary parallel straight lines. (3) For the observation image of another screen of the same sample, perform the same operation 5 times, and set the average particle diameter of the particles in the first resin layer as the value obtained by averaging the particle diameters of a total of 50 samples . Regarding the average particle diameter of the particles of the second resin layer described below, first, a section of the writing sheet is photographed by TEM or STEM. After photographing, the same method as above (2) and (3) is carried out, whereby the average particle diameter of the particles of the second resin layer can be calculated. The acceleration voltage of TEM or STEM is preferably set at 10 kv to 30 kV, and the magnification is preferably set at 50,000 to 300,000 times.

The second resin layer is a layer that smoothes the unevenness of the first resin layer. Therefore, the second resin layer preferably does not contain particles having an average particle diameter of 0.2 μm or more. The film thickness of the second resin layer is preferably from 0.01 to 0.15 μm, more preferably from 0.05 to 0.10 μm.

When the second resin layer contains particles, the average particle diameter of the particles is preferably less than 0.2 μm, more preferably 0.01 to 0.2 μm. As the particles of the second resin layer, the same organic particles and inorganic particles as exemplified as the particles of the first resin layer can be used. Among them, from the viewpoint of reducing reflectance, hollow particles are preferable, and hollow silica is more preferable. The content of the particles in the second resin layer is preferably 20-60% by mass, more preferably 30-50% by mass, of the total solid content forming the second resin layer.

The resin components of the first resin layer and the second resin layer preferably include a cured product of a thermosetting resin composition or a radiation-curable resin composition, and more preferably include a cured product of a thermosetting resin composition or a radiation-curable resin composition, and more preferably include The cured product of the ionizing radiation curable resin composition further preferably includes a cured product of 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 hardened by heating. Examples of the thermosetting resin 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 these curable resins 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)acryl, vinyl, and allyl groups, epoxy groups, oxetanyl groups, and the like. As the ionizing radiation curable compound, it is preferably a compound having an ethylenically unsaturated bonding group, more preferably a compound having two or more ethylenically unsaturated bonding groups, and among them, it is even more preferable to have two or more Polyfunctional (meth)acrylate compound of ethylenically unsaturated bond group. Both monomers and oligomers can be used as the polyfunctional (meth)acrylate compound. Furthermore, the so-called ionizing radiation refers to electromagnetic waves or charged particle beams that have energy quanta 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 polyfunctional (meth)acrylate compounds, examples of bifunctional (meth)acrylate monomers include ethylene glycol di(meth)acrylate, bisphenol A tetraethoxy diacrylate , bisphenol A tetrapropoxy diacrylate, 1,6-hexanediol diacrylate, etc. Examples of (meth)acrylate-based monomers having three or more functions include: trimethylolpropane tri(meth)acrylate, neopentylthritol tri(meth)acrylate, neopentylitol tetra(meth)acrylate, Meth)acrylate, diperythritol hexa(meth)acrylate, dipenteoerythritol tetra(meth)acrylate, isocyanuric acid modified tri(meth)acrylate, etc. In addition, the above-mentioned (meth)acrylate-based monomers can also be modified by modifying a part of the molecular skeleton, and can also be modified by ethylene oxide, propylene oxide, caprolactone, isocyanuric acid, alkyl, Modified by cyclic alkyl, aromatic, bisphenol, etc.

In addition, examples of polyfunctional (meth)acrylate oligomers include urethane (meth) acrylate, epoxy (meth) acrylate, polyester (meth) ) acrylate, polyether (meth)acrylate and other acrylate-based polymers. Urethane (meth)acrylates can be obtained, for example, by reacting polyhydric alcohols and organic diisocyanates with hydroxy (meth)acrylates. In addition, preferred epoxy (meth)acrylates are obtained by reacting aromatic epoxy resins, cycloaliphatic epoxy resins, aliphatic epoxy resins, etc. with more than three functions with (meth)acrylic acid (meth)acrylic acid. (base) acrylates; (meth)acrylates obtained by reacting difunctional or higher aromatic epoxy resins, alicyclic epoxy resins, aliphatic epoxy resins, etc. with polybasic acids and (meth)acrylic acid; And (meth)acrylates obtained by reacting difunctional or higher aromatic epoxy resins, alicyclic epoxy resins, aliphatic epoxy resins, etc. with phenols and (meth)acrylic acid. The above ionizing radiation curable compounds may be used alone or in combination of two or more.

類等中之1種以上。 該等光聚合起始劑較佳為熔點為100℃以上。藉由將光聚合起始劑之熔點設為100℃以上，而於書寫片之製造過程、或觸控面板之透明導電膜之形成過程中所殘留之光聚合起始劑昇華，而可防止製造裝置或透明導電膜之污染。 又，光聚合促進劑係可減輕硬化時之由空氣引起之聚合抑制而使硬化速度加快者，例如可列舉：選自對二甲胺基苯基苯甲酸異戊酯、對二甲胺基苯甲酸乙酯等中之1種以上。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. Examples of photopolymerization initiators include: acetophenone, benzophenone, α-hydroxyalkylphenone, michelerone, benzoin, benzoyldimethylketal, benzoylbenzene Formic esters, α-acyl oxime esters, 9-oxothiol

One or more of the categories. These photopolymerization initiators preferably have a melting point of 100° C. or higher. By setting the melting point of the photopolymerization initiator at 100°C or higher, sublimation of the photopolymerization initiator remaining in the writing sheet manufacturing process or the formation process of the transparent conductive film of the touch panel can be prevented, thereby preventing production Contamination of the device or transparent conductive film. In addition, the photopolymerization accelerator can reduce the polymerization inhibition caused by air during hardening and accelerate the hardening speed, for example, it can be selected from isoamyl p-dimethylaminophenylbenzoate, p-dimethylaminophenyl One or more of ethyl formate and the like.

The plastic film can be made of polyester, triacetyl cellulose (TAC), cellulose diacetate, cellulose acetate butyrate, polyamide, polyimide, polyether, polyethylene, polypropylene, polymethylpentene , polyvinyl chloride, polyvinyl acetal, polyether ketone, polymethyl methacrylate, polycarbonate, polyurethane and amorphous olefin (Cyclo-Olefin-Polymer: COP) and other resins. Among these plastic films, polyester (polyethylene terephthalate (PET), polyethylene naphthalene), which has been stretched, especially biaxially stretched, is preferred from the viewpoint of mechanical strength or dimensional stability. ethylene formate (PEN)). The thickness of the plastic film is preferably 5-200 μm, more preferably 10-150 μm.

Regarding the resin layer, it is preferable to contain a fluorine-based leveling agent, a silicone-based leveling agent, or a fluoropolysiloxane copolymer-based leveling agent from the viewpoint of making it easier to satisfy the conditions (A1) and (A2). One or two or more leveling agents. Also, the content of the leveling agent is preferably 0.01 to 5% by mass of the total solid content of the resin layer, more preferably 0.1 to 3% by mass.

As the solvent of the resin layer coating liquid, there is no problem as long as it is a commonly used organic solvent. Among these solvents, ketone-based solvents are preferred, and methyl ethyl ketone and methyl isobutyl ketone are more preferred. of mixed solvents. When the resin layer is composed of two or more layers, it is preferable to use a ketone-based solvent as the solvent for the resin layer coating solution on the outermost surface. The ketone-based solvent is preferable in that it is easy to form a surface satisfying the conditions (A1) and (A2) because it is easy to balance the smoothness of the surface and the adhesion to the underlayer.

The writing sheet of Embodiment A can improve the writing feeling by being used as a writing sheet for a touch panel pen (touch panel pen (A)) in which X derived from the above formula (i) is 500 MN/m or less . When using the writing sheet of Embodiment A as a writing sheet for a touch panel pen whose X derived from the above formula (i) is 100 MN/m or less, the writing feeling can be improved. When the writing sheet is a writing sheet for a touch panel pen in which X derived from the above formula (i) is 0.1 MN/m or more and 50 MN/m or less, the writing feeling can be further improved.

The values of Young's modulus E, diameter D, and arithmetic mean height Pa of the touch panel pen (A) are not particularly limited as long as they satisfy the above formula (i), but are preferably approximately within the following range. Young's modulus E is preferably 0.001 to 2.5 GPa (1.0×10 ⁶ to 2.5×10 ⁹ N/m ² ), more preferably 0.002 to 1.7 GPa (2.0×10 ⁶ to 1.7×10 ⁹ N/m ² ) . The diameter D is preferably from 0.3 to 6.0 mm, more preferably from 0.5 to 2.0 mm. The arithmetic mean height Pa is preferably from 0.01 to 150 μm, more preferably from 1.0 to 120 μm. Also, the radius of curvature of the pen tip of the touch panel pen (A) is not particularly limited, and it is easier to exert the effect when the radius of curvature is 0.3 to 1.5 mm, and it is easier to further improve the radius of curvature when the radius of curvature is 0.5 to 0.8 mm. play an effect.

[touch panel] The touch panel of Embodiment A is a touch panel having a sheet on the surface, and the surface of the writing sheet for a touch panel pen of Embodiment A satisfying the conditions (A1) and (A2) as the sheet is arranged so as to face the touch panel. The surface of the panel is made.

Examples of the touch panel include resistive film touch panels, capacitive touch panels, in-cell touch panels, optical touch panels, ultrasonic wave touch panels, and electromagnetic induction touch panels.

The resistive film type touch panel 100 is, as shown in FIG. 3 , a configuration in which the conductive films 30 having a pair of transparent substrates 20 above and below the conductive film 30 face each other with spacers 40 interposed therebetween. It is a basic configuration, and a circuit not shown is connected to the basic configuration. In the case of a resistive film type touch panel, for example, the following configuration can be cited: the writing sheet 10 of Embodiment A is used as the upper transparent substrate 20, and the side of the writing sheet 10 that satisfies the conditions (A1) and (A2) The surface facing the touch panel 100 is used. Also, although not shown in the figure, a resistive film type touch panel may also be configured as follows: on the upper transparent substrate, the side of the writing sheet of Embodiment A that satisfies the conditions (A1) and (A2) faces the surface. Bonding; or place the writing sheet of Embodiment A on the upper transparent substrate so that the side that satisfies the conditions (A1) and (A2) faces the surface, and fix it with a frame or the like.

The capacitive touch panel includes a surface type and a projection type, and the projection type is often used. The projection-type capacitive touch panel is formed by connecting a circuit to a basic structure in which an X-axis electrode and a Y-axis electrode perpendicular to the X-axis electrode are arranged through an insulator. If the basic structure is described in more detail, it can be listed as follows: Forming X-axis electrodes and Y-axis electrodes on different surfaces on a transparent substrate; Forming X-axis electrodes, an insulator layer, and Y-axis The state of the electrodes; as shown in FIG. 4, the X-axis electrode 50 is formed on the transparent substrate 20, the Y-axis electrode 60 is formed on the other transparent substrate 20, and the state of laminating through the insulator layer 70 such as an adhesive layer, etc. Furthermore, an aspect in which another transparent substrate is further laminated among these basic aspects can be mentioned. In the case of an electrostatic capacitive touch panel, for example, the following configuration can be cited: the writing sheet 10 of Embodiment A is used as the transparent substrate 20 on the front side, and the writing sheet 10 satisfies the conditions (A1) and (A2) The side surface faces the surface of the touch panel 100 for use. Also, although not shown in the figure, the capacitive touch panel may also be configured as follows: on the transparent substrate on the front side, the writing sheet of Embodiment A is placed on the side that satisfies the conditions (A1) and (A2) toward the front surface Alternatively, place the writing sheet of Embodiment A on the transparent substrate on the surface side so that the side that satisfies the conditions (A1) and (A2) faces the surface, and fix it with a frame or the like.

The electromagnetic induction touch panel is a touch panel using a special pen that generates a magnetic field. The electromagnetic induction type touch panel has at least a sensor part for detecting electromagnetic energy generated from the pen, and further has a transparent substrate on the sensor part. The transparent substrate can also be composed of multiple layers. In the case of an electromagnetic induction touch panel, for example, the following configuration can be cited: the writing sheet of Embodiment A is used as the outermost transparent substrate among the transparent substrates on the sensor portion, and the writing sheet satisfies the condition ( Use with the sides of A1) and (A2) facing the surface of the touch panel. Alternatively, in the case of an electromagnetic induction touch panel, it may also be configured as follows: on the outermost transparent substrate among the transparent substrates located on the sensor portion, the writing sheet of Embodiment A is placed to satisfy the condition (A1) and (A2) side facing the surface; or on the outermost transparent substrate, the writing sheet of embodiment A is placed so that the side of the conditions (A1) and (A2) is facing the surface It is placed and fixed with a frame or the like. The in-cell touch panel is one in which touch panel functions such as resistive film type, electrostatic capacitive type, and optical type are embedded in a liquid crystal element formed by sandwiching liquid crystal between two glass substrates. In the case of an in-cell touch panel, for example, the following configuration can be cited: the writing sheet of Embodiment A is bonded to the glass substrate on the surface side so that the side of the writing sheet satisfying the conditions (A1) and (A2) faces the surface. And use. Furthermore, another layer, such as a polarizing plate, may be provided between the glass substrate on the surface side and the writing sheet of Embodiment A.

[display device] The display device of Embodiment A is a display device having a touch panel, and the touch panel is the touch panel of Embodiment A.

As a display element, a liquid crystal display element, an EL display element, a plasma display element, an electronic paper element, an in-cell touch panel liquid crystal display element, etc. are mentioned. When the display element is a liquid crystal display element, an EL display element, a plasma display element, or an electronic paper element, the touch panel of Embodiment A is mounted on these display elements. In the display device of the embodiment A, since the writing feeling becomes good without excessive damage to the surface, it is possible to suppress damage to the resolution of the display element. In particular, it is preferable in suppressing the reduction of the resolution of ultra-high-definition display elements with a pixel density of 300 ppi or more.

[Selection method of writing sheet for touch panel pen] Regarding the selection method of writing sheet for touch panel pen of Embodiment A, the maximum height roughness Rz _0.8 and roughness of JIS B0601:2001 with a cutoff value of 0.8 mm are selected. The maximum valley depth of the curve Rv _0.8 , and the cut-off value of 2.5 mm in JIS B0601: 1994 the average interval S _2.5 of the local peaks meet the following conditions (A1) and (A2) as the following touch panel pen (A ) with a writing tablet. 0.35≦Rv _0.8 ／Rz _0.8 ≦0.60 (A1) 0.05 mm≦S _2.5 ≦0.30 mm (A2) <Touch panel pen (A)> This touch panel pen is attached between the tip and shaft of the touch panel pen When the apparent Young's modulus of the structure is E, the diameter of the nib is D, and the arithmetic mean height of the profile curve in the unit measurement interval (0.5 mm) of the nib is Pa, the following formula (i ) derived X is below 500 MN/m. X (MN/m) = [E×D×D]/Pa (i)

Regarding the selection method of the writing sheet for the touch panel pen of Embodiment A, even if the writing test of the touch panel pen is not carried out, the touch panel pen (touch panel pen) in which X in the above formula (i) is 500 MN/m or less can be selected. Control panel pen (A)) is a writing sheet with a good writing feeling, and can efficiently carry out the product design and quality control of the writing sheet. .

The judgment conditions for selecting a writing sheet for a touch panel pen set the above (A1) and (A2) as essential conditions. The determination conditions of conditions (A1) and (A2) are preferably within the preferred numerical range of the writing sheet of the above-mentioned embodiment A. For example, the determination condition of condition (A1) is preferably 0.37≦Rv _0.8 /Rz _0.8 ≦0.58.

Regarding the method of selecting the writing sheet for the touch panel pen of Embodiment A, it is more preferable to apply the following conditions (A3) from the viewpoint of improving the writing feeling and suppressing the decrease in the resolution of the display element. One or more of (A6) is used as a determination condition, and it is more preferable to set all (A3) to (A6) as a determination condition. 0.01 μm≦Ptm≦1.00 μm (A3) 0.01 μm≦Ra _0.8 ≦0.50 μm (A4) _Cs 250% or more (A5) Haze less than 5.0% (A6) Judgment conditions for conditions (A3) to (A6) It is preferably the preferred numerical range of the writing sheet of the above-mentioned embodiment A.

<Embodiment B> [Writing sheet for touch panel pen] The writing sheet for touch panel pen of Embodiment B is the following writing sheet for touch panel pen (B), and the writing sheet has a cutoff value of 0.8 mm. The maximum height roughness Rz _0.8 of JIS B0601: 2001 and the maximum mountain height Rp _0.8 of the roughness curve, and the skewness Psk of the profile curve in the measurement interval 1 mm satisfy the following conditions (B1) and (B2) of the surface, and The haze of JIS K7136:2000 of the writing sheet satisfies the following condition (B3). 0.50<Rp _0.8 ／Rz _0.8 ≦0.75 (B1) 0.60≦Psk (B2) Haze less than 5.0% (B3) When the apparent Young's modulus of the structure of the nib and the shaft is E, the diameter of the nib is D, and the arithmetic mean height of the profile curve in the unit measurement interval (0.5 mm) of the nib is Pa, the bottom X derived from formula (i) exceeds 500 MN/m. X (MN/m) = [E×D×D]/Pa (i) Furthermore, the unit of Young’s modulus E is “N/m ² ”, the unit of the diameter D of the nib is “m”, and the arithmetic mean The unit of height Pa is "m". Also, "M" means "mega (10 ⁶ )".

Fig. 1 is a sectional view showing an embodiment of a writing sheet 10 for a touch panel pen according to Embodiment B. The writing sheet 10 for a touch panel pen in FIG. 1 has a resin layer 2 on one surface of a plastic film 1 . The writing sheet 10 for a touch panel pen in FIG. 2 is a single-layer structure of the resin layer 2 . The writing sheet for a touch panel pen of Embodiment B may satisfy the conditions (B1) and (B2) on one surface, or satisfy the conditions (B1) and (B2) on both surfaces. The writing sheet for a touch panel pen of Embodiment B may be in the form of a single sheet, or may be in the form of a roll in which a long sheet is wound into a roll. Hereinafter, the writing sheet for a touch panel pen may be referred to as a "writing sheet". In addition, below, the surface which satisfies the conditions (B1) and (B2) may be called a "writing surface".

＜Writing surface＞ In the writing sheet for a touch panel pen of Embodiment B, at least one surface satisfies the conditions (B1) and (B2). In Embodiment B, the condition (B1) uses a roughness parameter with a cutoff value of 0.8 mm, while the condition (B2) uses a profile parameter. The reason for this will be described below.

The cutoff value is a value indicating the degree to which the profile curve 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 is a value indicating the fineness of a filter that cuts off moiré components (low frequency components) from the profile curve. If the cutoff value is larger, the filter is thinner, so the larger ripple components of the ripple components are cut off, but the smaller ripple components are not cut off. On the other hand, if the cutoff value is small, the filter is denser, so the moiré component is basically cut off. That is, a roughness parameter with a smaller cutoff value has a stronger influence on the unevenness of high-frequency components, and a roughness parameter with a larger cutoff value has a stronger influence on the unevenness of low-frequency components. For example, the roughness parameter with a cut-off value of 0.8 mm in condition (B1) represents the unevenness of high-frequency components (tiny regions). On the other hand, the profile parameter includes unevenness of both the roughness component (high frequency component) and the waviness component (low frequency component), and represents the unevenness of a large area.

The inventors of the present invention have diligently studied the relationship with the writing feeling of the writing sheet. It was found that the physical properties of the nib will seriously affect the writing feeling. The so-called physical properties of the pen tip here are based on the hardness of the pen tip and shaft structure of the touch panel pen (Young's modulus E), the diameter D of the pen tip, and the roughness of the pen tip (the arithmetic mean height Pa of the section curve of the pen tip) , "X" calculated from the above formula (i). The case where X seriously affects the writing feeling can be described as follows. First, Young's modulus E is a basic physical property indicating the ease with which a pen tip deforms under load, and there is a tendency that the smaller the Young's modulus E, the easier the pen tip deforms under load. Then, the square of the diameter D indicates the degree of load distribution, and there is a tendency that the smaller the square of the diameter D is, the harder it is to distribute the load, and the easier the pen tip is to deform due to the load. That is, it shows that the smaller the "Young's modulus E×diameter D×diameter D", the easier the nib is deformed, and the easier it is for the nib to come into contact with the writing sheet. Then, the arithmetic mean height Pa of the profile curve of the nib represents the extent to which the nib touches the writing sheet. Specifically, the larger the Pa, the more the point contact between the pen point and the writing sheet becomes, and the smaller the contact area between the pen point and the writing sheet becomes. Therefore, it means that the smaller the value of "X" calculated from [Young's modulus E×diameter D×diameter D]÷Pa, the easier the nib and the writing sheet are to adhere closely, which will have a significant impact on the writing feeling.

Furthermore, the inventors of the present invention have diligently studied the relationship between the X value and the writing feeling. As a result, the following (a) and (b) were found. (a) In the stage where the pen is brought into contact with the writing sheet, the nib is grounded on the surface of the writing sheet. When the value of X is large, it is difficult for the pen tip to be in close contact with the surface of the writing sheet, so it is considered that when the pen tip crosses the convex part of the high-frequency component (tiny area), it will trigger the start of writing. Therefore, the unevenness of the tiny area (roughness parameter with a cut-off value of 0.8 mm) has a greater influence on the writing feeling at the beginning of writing. (b) In the stage after starting to write, the nib moves along the concave-convex surface of a larger area. Therefore, the unevenness of a larger area has a greater influence on the writing feeling after starting writing. As mentioned above, when the value of X is large, the unevenness of the tiny area (roughness parameter with a cut-off value of 0.8 mm) has a greater influence on the writing feeling at the beginning of writing. On the other hand, the unevenness (profile parameter) in a larger area has a greater influence on the writing feeling after starting to write. Therefore, in Embodiment B, the condition (B1) uses a roughness parameter with a cutoff value of 0.8 mm, while the condition (B2) uses a profile parameter. Furthermore, when writing characters or drawing graphics, most of them stop writing for a moment and then start writing (for example, when changing the writing direction, they usually stop writing for a moment. Also, when moving the writing position, they also stop writing for a moment). The present inventors also regard this as "starting writing" just after starting writing again.

Condition (B1) requires the maximum height roughness Rz _0.8 of JIS B0601: 2001 with a cut-off value of 0.8 mm, and the maximum height Rp _0.8 of the roughness curve of JIS B0601: 2001 with a cut-off value of 0.8 mm to satisfy 0.50 < Rp _0.8 / Rz _0.8 ≦0.75. The cut-off value for condition (B1) was 0.8 mm. The condition (B1) is a parameter indicating unevenness of high-frequency components and mainly affecting the writing feeling at the beginning of writing.

Rp _0.8 /Rz _0.8 in condition (B1) means the ratio of Rp (maximum mountain height) to Rz (sum of maximum mountain height and valley depth maximum). As mentioned above, the pen tip is grounded on the surface of the writing sheet in the stage of bringing the pen into contact with the writing sheet. When the value of X is large, it is difficult for the pen tip to be in close contact with the surface of the writing sheet, so when the pen tip crosses the convex part of the high-frequency component (tiny area), it will trigger the start of writing. Therefore, Rp _0.8 /Rz _0.8 will have a great influence on the writing feeling at the beginning of writing. In Embodiment B, by setting Rp _0.8 /Rz _0.8 within the above-mentioned range, the frictional resistance of the pen point at the start of writing becomes appropriate, and the writing feeling at the start of writing can be improved. Also, by setting Rp _0.8 /Rz _0.8 within the above range, the pen can be easily made to stand still on the surface of the writing sheet. On the other hand, when Rp _0.8 /Rz _0.8 is 0.50 or less, the ratio of mountains is too small, so the frictional resistance is small and the writing feeling becomes smooth, and the writing feeling at the beginning of writing cannot be improved. Furthermore, when Rp _0.8 /Rz _0.8 is 0.50 or less, it is difficult to stop the pen at the end of writing. Also, when Rp _0.8 /Rz _0.8 exceeds 0.75, the ratio of mountains is too large, so the feeling of being stuck becomes strong, and the writing feeling at the beginning of writing cannot be improved.

The condition (B1) preferably satisfies 0.53≦Rp _0.8 /Rz _0.8 ≦0.70, more preferably satisfies 0.58≦Rp _0.8 /Rz _0.8 ≦0.65. In addition, Rp _0.8 and Rz _0.8 used as the reference of the calculation condition (B1) were made into the average value at the time of measuring once for each of 20 samples. In addition, the following Psk, Ptm, S _2.5 and Ra _0.8 , transmission clarity, and haze were also set as average values when each of 20 samples was measured once.

Condition (B2) requires that the skewness Psk of the profile curve in the measurement interval of 1 mm be 0.60 or more. Psk is a parameter of a cross-sectional shape including both a roughness component (high frequency component) and a waviness component (low frequency component), and represents unevenness in a large area. Psk is a parameter related to the probability density of unevenness. If the condition (B2) is not satisfied, it means that if Psk is small, the proportion of the convex part in the concavo-convex part of the larger area is high. In the case where the proportion of the convex part is higher in the unevenness of the larger area, the nib does not advance along the unevenness, but moves in such a way as to connect the apex of the convex part, and the frictional resistance decreases. Therefore, when the condition (B2) is not satisfied, the frictional resistance after starting to write is reduced and the feeling becomes smooth. On the other hand, if the condition (B2) is satisfied and Psk is large, it means that the proportion of concave portions among the concave-convex portions in a larger area is high. In this case, since the pen tip advances along the unevenness of a large area, it is given moderate frictional resistance. Psk is obtained by applying the skewness Rsk of the roughness curve of JIS B0601:2001 to the profile curve, and can be calculated by the same formula as Rsk. Furthermore, the reason why the parameters obtained by applying Rp _0.8 /Rz _0.8 of the condition (B1) to the profile curve is not used as the profile parameter of the condition (B2) is that because of the large area of the profile parameter, if it is such as Rp _0.8 /Rz _0.8 uses the parameter of the maximum value in the area, the error of each measurement area is too large, and the reliability of the parameter becomes low.

The condition (B2) preferably satisfies 0.80≦Psk, more preferably satisfies 0.90≦Psk. In addition, when Psk is too large, the antiglare property tends to deteriorate, so Psk is preferably 5.00 or less, more preferably 3.00 or less, still more preferably 2.00 or less.

＜Haze＞ The writing sheet for touch panel pens according to Embodiment B is one in which the haze of JIS K7136:2000 satisfies the following condition (B3). The haze is above 5.0% (B3)

By satisfying the condition (B3) and satisfying the above-mentioned conditions (B1) and (B2), the anti-glare property and the writing feeling can be improved.

The haze is preferably at least 10.0%, more preferably at least 15.0%. Furthermore, if the haze is too high, the resolution of the display device will be greatly reduced. Therefore, the haze is preferably at most 40.0%, more preferably at most 30.0%. In the measurement of haze and clarity of transmitted image described below, light is incident from the surface of the writing sheet opposite to the writing surface. When both sides of the writing sheet satisfy the above-mentioned conditions (B1) and (B2), the light incident side can be either side.

Also, the writing sheet of embodiment B is preferably set to 1 mm in the unit measurement interval, the maximum value of the mountain height of the profile curve in the unit measurement interval is set to Pp, and the maximum value of the valley depth of the profile curve in the unit measurement interval is set to Pv, the sum of Pp and Pv is set as the maximum profile height Pt of the profile curve in the unit measurement interval, and when the average value of Pt in the 5 measurement intervals is set as Ptm, the Ptm of the writing surface satisfies the following conditions (B4) . 0.30 μm≦Ptm≦7.00 μm （B4） Furthermore, the so-called maximum value Pp of the mountain height of the profile curve in the unit measurement interval refers to the part above the elevation mean line of the unit measurement interval defined as a mountain, indicating the height of the highest mountain. Also, the maximum value Pv of the valley depth of the profile curve in the unit measurement interval is defined as the valley below the elevation mean line of the unit measurement interval, and indicates the depth of the deepest valley.

As mentioned above, the unevenness of a larger area has a greater influence on the writing feeling after starting to write. Condition (B4) means that in the unevenness of a large area, the level difference is neither too small nor too large. Therefore, by making condition (B4) into the said range, the writing feeling from the start of writing to the end of writing can be made more favorable. The condition (B4) preferably satisfies 0.50 μm≦Ptm≦5.00 μm, and more preferably satisfies 1.00 μm≦Ptm≦4.00 μm.

In addition, in the writing sheet of Embodiment B, it is preferable that S _2.5 of the writing surface satisfies the following condition (B5) when the average interval of local peaks in JIS B0601:1994 with a cut-off value of 2.5 mm is S _2.5 . 0.02 mm≦S _2.5 ≦0.20 mm (B5) The cut-off value of condition (B5) is 2.5 mm. The condition (B5) is a parameter indicating the unevenness of the low-frequency component and mainly affecting the writing feeling after starting to write. By satisfying the condition (B5), the frictional resistance after the start of writing becomes appropriate, and the writing feeling after the start of writing can be improved. The condition (B5) preferably satisfies 0.02 mm≦S _2.5 ≦0.15 mm, and further preferably satisfies 0.03 mm≦S _2.5 ≦0.15 mm. Furthermore, if S _2.5 is 0.20 mm or less, it is also preferable in terms of improving the anti-glare property.

In addition, it is preferable that the writing surface of the writing sheet of Embodiment B satisfy the following condition (B6) with an arithmetic average roughness Ra of _0.8 of JIS B0601:2001 with a cutoff value of 0.8 mm. 0.10 μm≦Ra _0.8 ≦0.25 μm (B6) By setting Ra _0.8 in the above-mentioned range, the writing feeling can be further improved. Moreover, by making _Ra0.8 into 0.10 micrometer or more, antiglare property can be made favorable easily. In addition, by setting Ra _0.8 to be 0.25 μm or less, it is possible to suppress a large decrease in the resolution of the display device by the writing sheet. The condition (B6) is more preferably 0.10 μm≦Ra _0.8 ≦0.20 μm, further preferably 0.13 μm≦Ra _0.8 ≦0.17 μm.

Also, the writing surface of the writing sheet of Embodiment B preferably satisfies the following condition (B7) with a ten-point average roughness Rz _JIS0.8 of JIS B0601:2001 with a cutoff value of 0.8 mm. 0.50 μm≦Rz _JIS0.8 ≦1.50 μm (B7) By making Rz _JIS0.8 into the above-mentioned range, the writing feeling can be made more favorable. Moreover, by making Rz _JIS0.8 into 0.50 micrometer or more, antiglare property can be made favorable easily. In addition, by setting Rz _JIS0.8 to 1.50 μm or less, it is possible to suppress a large decrease in the resolution of the display element by the writing sheet while providing it. In particular, it is preferable in suppressing the reduction of the resolution of ultra-high-definition display elements with a pixel density of 300 ppi or more. The condition (B7) is more preferably 0.50 μm≦Rz _JIS0.8 ≦1.25 μm, further preferably 0.60 μm≦Rz _JIS0.8 ≦1.00 μm.

Furthermore, in the writing sheet of Embodiment B, it is preferable to fix the touch panel pen (B) in the state of contacting the writing surface at an angle of 60 degrees, and apply a vertical load of 100 gf to the touch panel pen (B) on one side. One side scans a length of 40 mm in a single pass at a speed of 14 mm/s. When the dynamic friction coefficient acting on the scanning direction of the touch panel pen (B) at this time is set to μk, and the static friction coefficient is set to μs, it satisfies 0.30≦μk/ The relationship between μs≦0.58. Furthermore, in the embodiment B, the kinetic friction coefficient μk means the average value of the kinetic friction coefficients at all measurement times. The coefficient of static friction is set as the peak value of the initial friction force that becomes higher than the coefficient of dynamic friction as the measurement time elapses from the friction force 0. The measurement interval of the coefficient of friction is preferably set at 0.02 seconds. When writing characters or drawing graphics, most people stop writing for a moment and then start writing (for example, when changing the writing direction, they usually stop writing for a moment. Also, when moving the writing position, they also stop writing for a moment). When starting writing after stopping writing for a while as above, it is easily affected by the difference between the coefficient of static friction and the coefficient of dynamic friction. Imaginary writing (for example, writing direction can be changed to desired direction). In order to satisfy the relationship of 0.30≦μk/μs≦0.58, it is better to satisfy the above conditions (B1) and (B2), in addition to the above conditions (B1) and (B2), it is better to satisfy one of the conditions (B4) ~ (B7) It is more preferable to satisfy all of the above-mentioned conditions (B1), (B2), (B4) to (B7). Moreover, in order to make the above effect more favorable, it is more preferable that μk/μs satisfies the relationship of 0.30≦μk/μs≦0.44. μk/μs is a value obtained by calculating the μk/μs of each sample by measuring once for each of the 20 samples, and averaging the μk/μs of the 20 samples.

Furthermore, even when the touch panel pen is fixed while touching the writing surface at an angle other than 60 degrees (for example, any angle in the range of 30 to 75 degrees), μk/μs is preferably within the above range. Also, even when the scanning speed is set to a speed other than 14 mm/sec (for example, any speed in the range of 0.1 to 100 mm/sec), it is preferable that μk/μs is in the above-mentioned range.

Also, from the viewpoint of obtaining an appropriate sense of resistance without excessive smoothness, μk and μs are preferably in the following ranges. μk is preferably from 0.06 to 0.30, more preferably from 0.08 to 0.28, and still more preferably from 0.08 to 0.20. μs is preferably from 0.15 to 0.95, more preferably from 0.20 to 0.60, and still more preferably from 0.25 to 0.50.

μk and μs can be measured by the same method as that described in Embodiment A. Also, "Apparent Young's modulus E of the structure of the pen tip and shaft of the touch panel pen", "Diameter of the pen tip D", and "Arithmetic mean height Pa of the cross-sectional curve in the unit measurement interval (0.5 mm) of the pen tip ” can be measured by the same method as that described in Embodiment A.

In addition, the writing sheet of Embodiment B is better for the clearness of the transmitted image when the width of the optical frequency comb of the image resolution measuring instrument measured in accordance with JIS K7374:2007 is 0.125 mm, 0.5 mm, 1.0 mm and 2.0 mm. When the degree is set to C _0.125 , C _0.5 , C _1.0 and C _2.0 , the sum C _s of C _0.125 , C _0.5 , C _1.0 and C _2.0 is more than 100% and less than 250%, more preferably more than 120% and 230% or less, more preferably 150% or more and 200% or less. By setting C _s to 100% or more, it is possible to suppress a large decrease in the resolution of the display device by the writing sheet. Also, by setting C _s to less than 250%, the means for imparting anti-glare properties is not limited, and product design can be easily performed.

＜The overall composition of the writing sheet＞ The composition of the writing sheet for a touch panel pen of Embodiment B is not particularly limited as long as at least one surface satisfies the conditions (B1) and (B2). For example, as the composition of the writing sheet 10 for a touch panel pen according to Embodiment B, there is a resin layer 2 as shown in FIG. 1 and FIG. 2 , and one surface of the resin layer 2 satisfies the conditions (B1) and (B2). . Furthermore, although not shown in the figure, there may be other layers other than the resin layer or the plastic film, and the surface of the other layer satisfies the conditions (B1) and (B2). As another layer, an antistatic layer, an antifouling layer, etc. are mentioned. Moreover, although not shown in figure, the resin layer may consist of 2 or more layers.

The surface (writing surface) that satisfies the conditions (B1) and (B2) can be formed by (a) physical or chemical treatment such as embossing, sandblasting, etching, (b) molding using a mold, (c) coating, etc. Among these methods, molding using a mold (b) is preferable from the viewpoint of surface shape reproducibility, and coating (c) is preferable from the viewpoint of productivity and compatibility with various varieties.

Molding using a mold can be formed by making a mold having a shape complementary to a shape satisfying the conditions (B1) and (B2), pouring the material for forming the resin layer into the mold, and then taking it out from the mold. Here, if the material constituting the resin layer is used as the material, the material is poured into the mold, the plastic film is superimposed, and the resin layer is taken out from the mold together with the plastic film, the resin layer can be obtained on the plastic film, and The surface of the resin layer satisfies the requirements (B1) and (B2) of the writing sheet for a touch panel pen. In addition, the resin layer is directly taken out from the mold without using a plastic film, or the plastic film is taken out from the mold using a plastic film, and the plastic film can be obtained by using a single layer of the resin layer, and the surface of the resin layer satisfies the condition (B1 ) and (B2) writing sheets for touch panel pens. When using a curable resin composition (thermosetting resin composition or ionizing radiation curable resin composition) as the material to be poured into the mold, it is preferable to harden the curable resin composition before taking it out from the mold.

Regarding the formation of the resin layer by coating, it is possible to apply a resin layer forming coating liquid containing resin components, particles and solvents to the plastic film by known coating methods such as gravure coating and rod coating. on, dried and hardened. In order to make the surface shape of the resin layer formed by coating satisfy the above-mentioned conditions, it is preferable to use micron-sized particles and nano-sized inorganic ultrafine particles as particles, and the film thickness, particle content and average particle size of the particles Set it to the following range.

The film thickness of the resin layer is preferably from 1.5 to 10 μm, more preferably from 2 to 8 μm, still more preferably from 4 to 7 μm. For example, the film thickness of the resin layer can be measured based on the image of the section taken by a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM). And figured out. The acceleration voltage of TEM or STEM is preferably set at 10-30 kV, and the magnification is preferably set at 50,000-300,000 times.

As the particles (micron-sized particles) of the resin layer, either organic particles or inorganic particles can be used. Examples of organic particles include polymethyl methacrylate, polyacrylic acid-styrene copolymer, melamine resin, polycarbonate, polystyrene, polyvinyl chloride, benzoguanamine-melamine-formaldehyde condensate, polysilicon Particles made of oxygen, fluorine-based resins, and polyester-based resins. Examples of the inorganic particles include particles made of silica, alumina, antimony, zirconia, and titania. Among these particles, organic particles are preferred from the viewpoint of ease of dispersion control. The content of particles (micron-sized particles) in the resin layer is preferably 2 to 25% by mass, more preferably 5 to 20% by mass, and still more preferably 10 to 15% by mass, of the total solid content forming the resin layer.

The average particle diameter of the particles (micron-sized particles) in the resin layer is preferably from 0.2 to 8.0 μm, more preferably from 0.3 to 7.0 μm, and still more preferably from 0.5 to 5.0 μm. In the case of particle aggregation, it is preferable that the average particle diameter of the aggregated particles satisfies the above-mentioned range. The average particle diameter of the particles can be calculated by the same method as in Embodiment A.

The film thickness of the resin layer is preferably larger than the average particle diameter of the particles from the viewpoint of making it easier to make the surface shape of the writing sheet within the above-mentioned range. Specifically, the ratio of [average particle diameter of particles]/[film thickness of resin layer] is preferably 0.40 to 0.80, more preferably 0.45 to 0.75, and still more preferably 0.50 to 0.70.

Moreover, as particles, it is preferable to contain not only the above-mentioned micron-order particles but also nano-order inorganic ultrafine particles. By containing nano-order inorganic ultrafine particles, the surface shape of the resin layer can be easily made within the above-mentioned range. The reason for this is considered to be that the unevenness of the high-frequency component (unevenness in a small area) is formed by micron-sized particles. On the other hand, when inorganic ultrafine particles are contained, the formation is relatively gentle in the place where micron-sized particles do not exist. The inclination of the low-frequency component forms the unevenness of the low-frequency component (the unevenness of the larger area), resulting in a shape in which the unevenness of the high-frequency component and the unevenness of the low-frequency component are mixed. In the case of containing inorganic ultrafine particles, the thixotropy of the coating liquid and the drying characteristics of the solvent are affected, and the usual leveling will not occur, so the above-mentioned phenomenon occurs. Also, by containing inorganic ultrafine particles, a gentler inclination is also formed in the place where micron-sized particles do not exist, and as a result (as a result of reducing approximately smooth parts), the anti-glare property can also be improved.

Examples of inorganic ultrafine particles include ultrafine particles composed of silica, alumina, zirconia, and titania. Among these, silicon dioxide ultrafine particles are preferable from the viewpoint of transparency. The inorganic ultrafine particles preferably have an average primary particle diameter of 1 to 25 nm, more preferably 5 to 20 nm, from the viewpoint of easily obtaining the aforementioned uneven shape.

The inorganic ultrafine particles are preferably reactive inorganic ultrafine particles into which reactive groups are introduced by surface treatment. By introducing reactive groups, a large amount of inorganic ultrafine particles can be contained in the resin layer, and the surface shape of the writing sheet can be easily made within the above-mentioned range. As the reactive group, a polymerizable unsaturated group can be preferably used, preferably a photocurable unsaturated group, particularly preferably an ionizing radiation curable unsaturated group. Specific examples thereof include ethylenically unsaturated bonds such as (meth)acryl groups, (meth)acryloxy groups, vinyl groups, and allyl groups, epoxy groups, and the like. Such reactive inorganic ultrafine particles include inorganic ultrafine particles surface-treated with a silane coupling agent. When using a silane coupling agent to treat the surface of inorganic ultrafine particles, examples include: a dry method of spraying a silane coupling agent onto the inorganic ultrafine particles; or a method of dispersing the inorganic ultrafine particles in a solvent and then adding a silane coupling agent to react wet method, etc.

The content of the inorganic ultrafine particles is preferably 1 to 20% by mass, more preferably 2 to 15% by mass, and still more preferably 3 to 10% by mass of the total solid content forming the resin layer. By setting it as this range, it becomes easy to make the surface shape of a writing sheet into the said range by control of leveling property, and suppression of the polymerization shrinkage of a resin layer. Also, the ratio of the content of micron-sized particles and inorganic ultrafine particles in the resin layer (content of micron-sized particles/content of inorganic ultrafine particles) is preferable from the viewpoint of making it easy to make the surface shape of the writing sheet within the above-mentioned range. 1.0 to 3.0, more preferably 1.5 to 2.5.

The resin component of the resin layer preferably contains a thermosetting resin composition or a cured product of an ionizing radiation curable resin composition, and more preferably contains a free radiation curable resin composition from the viewpoint of improving the mechanical strength. Among them, the cured product preferably includes a cured product of 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 hardened by heating. Examples of the thermosetting resin 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 these curable resins 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)acryl, vinyl, and allyl groups, epoxy groups, oxetanyl groups, and the like. As the ionizing radiation curable compound, it is preferably a compound having an ethylenically unsaturated bonding group, more preferably a compound having two or more ethylenically unsaturated bonding groups, and among them, it is even more preferable to have two or more Polyfunctional (meth)acrylate compound of ethylenically unsaturated bond group. Both monomers and oligomers can be used as the polyfunctional (meth)acrylate compound. Furthermore, the so-called ionizing radiation refers to electromagnetic waves or charged particle beams that have energy quanta 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 polyfunctional (meth)acrylate compounds, examples of bifunctional (meth)acrylate monomers include ethylene glycol di(meth)acrylate, bisphenol A tetraethoxy diacrylate , bisphenol A tetrapropoxy diacrylate, 1,6-hexanediol diacrylate, etc. Examples of (meth)acrylate-based monomers having three or more functions include: trimethylolpropane tri(meth)acrylate, neopentylthritol tri(meth)acrylate, neopentylitol tetra(meth)acrylate, Meth)acrylate, diperythritol hexa(meth)acrylate, dipenteoerythritol tetra(meth)acrylate, isocyanuric acid modified tri(meth)acrylate, etc. In addition, the above-mentioned (meth)acrylate-based monomers can also be modified by modifying a part of the molecular skeleton, and can also be modified by ethylene oxide, propylene oxide, caprolactone, isocyanuric acid, alkyl, Modified by cyclic alkyl, aromatic, bisphenol, etc.

In addition, examples of polyfunctional (meth)acrylate oligomers include urethane (meth)acrylate, epoxy (meth)acrylate, polyester (meth)acrylate, polyether ( Acrylate-based polymers such as meth)acrylate, etc. Urethane (meth)acrylates can be obtained, for example, by reacting polyhydric alcohols and organic diisocyanates with hydroxy (meth)acrylates. In addition, preferred epoxy (meth)acrylates are obtained by reacting aromatic epoxy resins, cycloaliphatic epoxy resins, aliphatic epoxy resins, etc. with more than three functions with (meth)acrylic acid (meth)acrylic acid. (base) acrylates; (meth)acrylates obtained by reacting difunctional or higher aromatic epoxy resins, alicyclic epoxy resins, aliphatic epoxy resins, etc. with polybasic acids and (meth)acrylic acid; And (meth)acrylates obtained by reacting difunctional or higher aromatic epoxy resins, alicyclic epoxy resins, aliphatic epoxy resins, etc. with phenols and (meth)acrylic acid. The above ionizing radiation curable compounds may be used alone or in combination of two or more.

類等中之1種以上。 該等光聚合起始劑較佳為熔點為100℃以上。藉由將光聚合起始劑之熔點設為100℃以上，而於書寫片之製造過程、或觸控面板之透明導電膜之形成過程中所殘留之光聚合起始劑昇華，而可防止製造裝置或透明導電膜之污染。 又，光聚合促進劑係可減輕硬化時之由空氣引起之聚合抑制而使硬化速度加快者，例如可列舉：選自對二甲胺基苯基苯甲酸異戊酯、對二甲胺基苯甲酸乙酯等中之1種以上。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. Examples of photopolymerization initiators include: acetophenone, benzophenone, α-hydroxyalkylphenone, michelerone, benzoin, benzoyldimethylketal, benzoylbenzene Formic esters, α-acyl oxime esters, 9-oxothiol

One or more of the categories. These photopolymerization initiators preferably have a melting point of 100° C. or higher. By setting the melting point of the photopolymerization initiator at 100°C or higher, sublimation of the photopolymerization initiator remaining in the writing sheet manufacturing process or the formation process of the transparent conductive film of the touch panel can be prevented, thereby preventing production Contamination of the device or transparent conductive film. In addition, the photopolymerization accelerator can reduce the polymerization inhibition caused by air during hardening and accelerate the hardening speed, for example, it can be selected from isoamyl p-dimethylaminophenylbenzoate, p-dimethylaminophenyl One or more of ethyl formate and the like.

烷、四氫呋喃等）、脂肪族烴類（己烷等）、脂環式烴類（環己烷等）、芳香族烴類（甲苯、二甲苯等）、鹵化碳類（二氯甲烷、二氯乙烷等）、酯類（乙酸甲酯、乙酸乙酯、乙酸丁酯等）、醇類（丁醇、環己醇等）、溶纖劑類（甲基溶纖劑、乙基溶纖劑等）、乙酸溶纖劑類、亞碸類（二甲基亞碸等）、醯胺類（二甲基甲醯胺、二甲基乙醯胺等）等，亦可為該等之混合物。 於溶劑之乾燥過慢之情形時，樹脂層之整平性會變得過度，因此變得難以形成上述之表面形狀。因此，作為溶劑，較佳包含全部溶劑中之50質量%以上之蒸發速度（將乙酸正丁酯之蒸發速度設為100時之相對蒸發速度）為180以上之溶劑，更佳包含60質量%以上。作為相對蒸發速度為180以上之溶劑，可列舉：甲苯。甲苯之相對蒸發速度為195。In the coating liquid for forming a resin layer, a solvent is generally used to adjust the viscosity or to dissolve or disperse each component. Depending on the type of solvent, the surface state of the resin layer after the coating and drying process is different, so it is preferable to select the solvent by considering the saturated vapor pressure of the solvent, the permeability of the solvent to the transparent substrate, and the like. Specifically, examples of solvents include ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), ethers (di

alkane, tetrahydrofuran, etc.), aliphatic hydrocarbons (hexane, etc.), alicyclic hydrocarbons (cyclohexane, etc.), aromatic hydrocarbons (toluene, xylene, etc.), halocarbons (methylene chloride, dichloro ethane, etc.), esters (methyl acetate, ethyl acetate, butyl acetate, etc.), alcohols (butanol, cyclohexanol, etc.), cellosolves (methyl cellosolve, ethyl cellosolve etc.), acetic acid cellosolves, sulfides (dimethylsulfide, etc.), amides (dimethylformamide, dimethylacetamide, etc.), etc., or mixtures thereof. When the drying of the solvent is too slow, the leveling property of the resin layer becomes excessive, so it becomes difficult to form the above-mentioned surface shape. Therefore, as a solvent, it is preferable to contain 50% by mass or more of all solvents with an evaporation rate (relative evaporation rate when the evaporation rate of n-butyl acetate is 100) of 180 or more, more preferably 60% by mass or more. . Toluene is mentioned as a solvent whose relative evaporation rate is 180 or more. The relative evaporation rate of toluene is 195.

Moreover, it is preferable to contain a leveling agent in the coating liquid for forming a resin layer from the viewpoint of making the surface shape moderately smooth and making it easy to make the surface shape of the writing sheet within the above-mentioned range. Examples of leveling agents include fluorine-based leveling agents, silicone-based leveling agents, fluoropolysiloxane copolymer-based leveling agents, etc., preferably silicone-based leveling agents. The amount of the leveling agent added is preferably 0.01 to 0.5% by weight, more preferably 0.01 to 0.2% by weight, based on the total solid content of the resin layer forming coating liquid.

The plastic film can be made of polyester, triacetyl cellulose (TAC), cellulose diacetate, cellulose acetate butyrate, polyamide, polyimide, polyether, polyethylene, polypropylene, polymethylpentene , polyvinyl chloride, polyvinyl acetal, polyether ketone, polymethyl methacrylate, polycarbonate, polycarbonate and amorphous olefin (Cyclo-Olefin-Polymer: COP) and other resins. Among these plastic films, polyesters (polyethylene terephthalate, polyethylene naphthalate, polyethylene naphthalate) that have been stretched, especially biaxially stretched, are preferred from the standpoint of mechanical strength or dimensional stability. ester). The thickness of the plastic film is preferably 5-200 μm, more preferably 10-150 μm.

When the writing sheet of Embodiment B is used as a writing sheet for a touch panel pen (touch panel pen (B)) in which X derived from the above formula (i) exceeds 500 MN/m, the writing feeling can be improved. When the writing sheet of Embodiment B is used as a writing sheet for a touch panel pen whose X derived from the above formula (i) is 1,000 MN/m or more, the writing feeling can be improved. In the case of the writing sheet for a touch panel pen in which X derived from the formula (i) is 2,000 MN/m or more and 100,000 MN/m or less, the writing feeling can be further improved.

The values of Young's modulus E, diameter D, and arithmetic mean height Pa of the touch panel pen (B) are not particularly limited as long as they satisfy the above-mentioned formula (i), but are preferably approximately within the following range. The Young's modulus is preferably 0.1 to 5.0 GPa (1.0×10 ⁸ to 5.0×10 ⁹ N/m ² ), more preferably 0.5 to 2.5 GPa (5.0×10 ⁸ to 2.5×10 ⁹ N/m ² ). The diameter D is preferably from 0.3 to 6.0 mm, more preferably from 0.4 to 2.5 mm. The arithmetic mean height Pa is preferably from 0.01 to 10 μm, more preferably from 0.05 to 1.0 μm. Also, the radius of curvature of the pen tip of the touch panel pen (B) is not particularly limited, and it is easier to exert the effect when the radius of curvature is 0.3 to 1.5 mm, and it is easier to further improve the radius of curvature when the radius of curvature is 0.5 to 0.8 mm. play an effect.

[touch panel] The touch panel of Embodiment B is a touch panel having a sheet on the surface, and the surface of the writing sheet for a touch panel pen of Embodiment B satisfying the conditions (B1) and (B2) as the sheet is arranged to face the touch panel. The surface of the panel is made.

Examples of the touch panel include resistive film touch panels, capacitive touch panels, in-cell touch panels, optical touch panels, ultrasonic wave touch panels, and electromagnetic induction touch panels.

The resistive film type touch panel 100 is, as shown in FIG. 3 , a configuration in which the conductive films 30 having a pair of transparent substrates 20 above and below the conductive film 30 face each other with spacers 40 interposed therebetween. It is a basic configuration, and a circuit not shown is connected to the basic configuration. In the case of a resistive film type touch panel, for example, the following configuration can be cited: the writing sheet 10 of Embodiment B is used as the upper transparent substrate 20, and the side of the writing sheet 10 that satisfies the conditions (B1) and (B2) The surface facing the touch panel 100 is used. Also, although not shown in the figure, a resistive film type touch panel may also be configured as follows: on the upper transparent substrate, the writing sheet of Embodiment B is placed on the side that satisfies the conditions (B1) and (B2) facing the surface. Bonding; or place the writing sheet of Embodiment B on the upper transparent substrate so that the side that satisfies the conditions (B1) and (B2) faces the surface, and fix it with a frame or the like.

The capacitive touch panel includes a surface type and a projection type, and the projection type is often used. The projection-type capacitive touch panel is formed by connecting a circuit to a basic structure in which an X-axis electrode and a Y-axis electrode perpendicular to the X-axis electrode are arranged through an insulator. If the basic structure is described in more detail, it can be listed as follows: Forming X-axis electrodes and Y-axis electrodes on different surfaces on a transparent substrate; Forming X-axis electrodes, an insulator layer, and Y-axis The state of the electrodes; as shown in FIG. 4, the X-axis electrode 50 is formed on the transparent substrate 20, the Y-axis electrode 60 is formed on the other transparent substrate 20, and the state of laminating through the insulator layer 70 such as an adhesive layer, etc. Furthermore, an aspect in which another transparent substrate is further laminated among these basic aspects can be mentioned. In the case of a capacitive touch panel, for example, the following configuration can be cited: using the writing sheet 10 of Embodiment B as the transparent substrate 20 on the front side, and satisfying the conditions (B1) and (B2) of the writing sheet 10 The side surface faces the surface of the touch panel 100 for use. Also, although not shown in the figure, the capacitive touch panel may also be configured as follows: on the transparent substrate on the front side, the writing sheet of Embodiment B is placed on the side that satisfies the conditions (B1) and (B2) toward the front surface or place the writing sheet of Embodiment B on the transparent substrate on the surface side so that the side that satisfies the conditions (B1) and (B2) faces the surface, and fix it with a frame or the like.

The electromagnetic induction touch panel is a touch panel using a special pen that generates a magnetic field. The electromagnetic induction type touch panel has at least a sensor part for detecting electromagnetic energy generated from the pen, and further has a transparent substrate on the sensor part. The transparent substrate can also be composed of multiple layers. In the case of an electromagnetic induction touch panel, for example, the following configuration can be cited: the writing sheet of Embodiment B is used as the outermost transparent substrate among the transparent substrates on the sensor portion, and the writing sheet satisfies the condition ( Use with the sides of B1) and (B2) facing the surface of the touch panel. Alternatively, in the case of an electromagnetic induction touch panel, it may also be configured as follows: on the outermost transparent substrate among the transparent substrates located on the sensor portion, the writing sheet of Embodiment B is placed to satisfy the condition (B1) and (B2) side facing the surface; or on the outermost transparent substrate, the writing sheet of Embodiment B is placed so that the side of the conditions (B1) and (B2) is facing the surface It is placed and fixed with a frame or the like. The in-cell touch panel is one in which touch panel functions such as resistive film type, electrostatic capacitive type, and optical type are embedded in a liquid crystal element formed by sandwiching liquid crystal between two glass substrates. In the case of an in-cell touch panel, for example, the following configuration can be cited: the writing sheet of Embodiment B is attached to the glass substrate on the surface side so that the side that satisfies the conditions (B1) and (B2) faces the surface. Use together. Furthermore, another layer, such as a polarizing plate, may be provided between the glass substrate on the surface side and the writing sheet of Embodiment B.

[display device] The display device of Embodiment B is a display device having a touch panel, and the touch panel is the touch panel of Embodiment B.

As a display element, a liquid crystal display element, an EL display element, a plasma display element, an electronic paper element, an in-cell touch panel liquid crystal display element, etc. are mentioned. When the display element is a liquid crystal display element, an EL display element, a plasma display element, or an electronic paper element, the touch panel of Embodiment B is mounted on these display elements. In the display device of the embodiment B, since the writing feeling becomes good without excessively damaging the surface, it is possible to suppress a significant loss of the resolution of the display element.

[Selection method of writing sheet for touch panel pen] Regarding the selection method of writing sheet for touch panel pen of Embodiment B, the maximum height roughness Rz _0.8 and roughness of JIS B0601:2001 with a cutoff value of 0.8 mm are selected. The maximum height of the curve Rp _0.8 , and the skewness Psk of the profile curve in the measurement interval of 1 mm satisfy the following conditions (B1) and (B2), and the haze of JIS K7136: 2000 meets the following conditions (B3) The sheet is used as the writing sheet for the touch panel pen (B) described below. 0.50<Rp _0.8 ／Rz _0.8 ≦0.75 (B1) 0.60≦Psk (B2) Haze of 5.0% or more (B3) When the apparent Young's modulus of the structure of the nib and the shaft is E, the diameter of the nib is D, and the arithmetic mean height of the profile curve in the unit measurement interval (0.5 mm) of the nib is Pa, the bottom X derived from formula (i) exceeds 500 MN/m. X (MN/m) = [E×D×D]/Pa (i)

Regarding the selection method of the writing sheet for the touch panel pen of Embodiment B, even if the writing test of the touch panel pen is not carried out, the touch panel pen (touch panel pen) with X exceeding 500 MN/m in the above formula (i) can be selected. Panel pen (B)) is a writing sheet with good writing feeling and good anti-glare property, and can efficiently carry out product design and quality control of writing sheet.

The judgment conditions for selecting the writing sheet for the touch panel pen use the above (B1) to (B3) as the necessary conditions. The determination conditions of conditions (B1) to (B3) are preferably within the preferred numerical range of the writing sheet of the above-mentioned embodiment B. For example, the determination condition of condition (B1) is preferably 0.53≦Rp _0.8 /Rz _0.8 ≦0.70, more preferably 0.58≦Rp _0.8 /Rz _0.8 ≦0.65.

In the method of selecting writing sheets for touch panel pens according to Embodiment B, from the viewpoints of improving the writing feeling, improving the anti-glare property, and suppressing a large decrease in the resolution of the display element In other words, it is more preferable to set one or more of the following conditions (B4) to (B8) as the determination conditions, and it is more preferable to set all of the conditions (B4) to (B8) as the determination conditions. 0.30 μm≦Ptm≦7.00 μm (B4) 0.02 mm≦S _2.5 ≦0.20 mm (B5) 0.10 μm≦Ra _0.8 ≦0.25 μm (B6) 0.50 μm≦Rz _JIS0.8 ≦1.50 μm (B7) C _s is 100% More than but less than 250% (B8) The determination conditions of conditions (B4) to (B8) are preferably within the preferred numerical range of the writing sheet of the above-mentioned embodiment B.

<Embodiment C> [How to select writing sheet for touch panel pen] The method of selecting writing sheets for touch panel pens according to Embodiment C is to select those satisfying the following condition (C1) as writing sheets for touch panel pens. ＜Condition (C1)＞ Fix the touch panel pen in contact with the surface of the writing sheet for the touch panel pen at an angle of 60 degrees, apply a vertical load of 100 gf to the touch panel pen, and scan 40 mm at a speed of 14 mm/sec in one pass Assuming that the kinetic friction coefficient acting in the scanning direction of the touch panel pen at this time is μk and the static friction coefficient is μs, μk/μs is not less than 0.30 and not more than 0.58.

Fig. 1 is a cross-sectional view showing an embodiment of a writing sheet 10 for a touch panel pen according to Embodiment C. The writing sheet 10 for a touch panel pen in FIG. 1 has a resin layer 2 on one surface of a plastic film 1 . The writing sheet 10 for a touch panel pen in FIG. 2 is a single-layer structure of the resin layer 2 . The writing sheet for a touch panel pen of Embodiment C may satisfy the condition (C1) on one surface, or satisfy the condition (C1) on both surfaces. Hereinafter, a writing sheet for a touch panel pen may be referred to as a "writing sheet". In addition, below, the surface which satisfies the condition (C1) may be called a "writing surface".

＜Writing surface＞ The method of selecting writing sheets for touch panel pens according to Embodiment C is to select those having a surface satisfying the following condition (C1) as writing sheets for touch panel pens. When writing characters or drawing graphics, most people stop writing for a moment and then start writing (for example, when changing the writing direction, they usually stop writing for a moment. Also, when moving the writing position, they also stop writing for a moment). When writing starts after stopping writing for a moment as mentioned above, it is easily affected by the difference between the coefficient of static friction and the coefficient of dynamic friction. When the μk/μs is less than 0.30, or the μk/μs exceeds 0.58, it is difficult to change the writing direction to the desired direction when you stop writing for a moment and then start writing, and you cannot complete the imaginable writing. Therefore, selecting a writing sheet that satisfies the condition (C1) is related to efficiently selecting a writing sheet that can realize imaginary writing when writing is started after stopping writing for a moment. The condition (C1) preferably satisfies the relationship of 0.30≦μk/μs≦0.44. In Embodiment C, the kinetic friction coefficient μk means the average value of the kinetic friction coefficients at all measurement times. The coefficient of static friction is set as the peak value of the initial friction force that becomes higher than the coefficient of dynamic friction as the measurement time elapses from the friction force 0. The measurement interval of the coefficient of friction is preferably set at 0.02 seconds.

μk and μs are the average values obtained by measuring each of 20 samples once. μk/μs is a value obtained by calculating the μk/μs of each sample by measuring once for each of the 20 samples, and averaging the μk/μs of the 20 samples. μk and μs can be measured by the same method as that described in Embodiment A.

From the viewpoint of selecting a writing sheet that is not too smooth but has a moderate sense of resistance, it is preferable to select a writing sheet whose μk of the writing surface satisfies the following condition (C2). ＜Condition (C2)＞ 0.06≦μk≦0.30 The condition (C2) preferably satisfies 0.08≦μk≦0.28, and further preferably satisfies 0.08≦μk≦0.20. 0.06≦μk≦0.30

From the viewpoint of selecting a writing sheet that is not too smooth but has a moderate sense of resistance, the selection method of the writing sheet of Embodiment C is preferably to select a writing surface whose μs satisfies the following condition (C2'). <Condition (C2')> 0.15≦μs≦0.95 The condition (C2') preferably satisfies 0.20≦μs≦0.60, and further preferably satisfies 0.25≦μs≦0.50.

The touch panel pens used in the determination of conditions (C1), (C2) and (C2') are not particularly limited, and can be appropriately selected from commercially available touch panel pens. Furthermore, it becomes difficult to design a writing sheet that satisfies the condition (C1) and the like when the pen is too closely attached to the writing sheet or when the pen is not in close contact with the writing sheet. Therefore, it is preferable to set the apparent Young's modulus of the structure constituting the nib and shaft of the touch panel pen as E and the diameter of the pen tip as D for the touch panel pen used in the judgment of condition (C1). , when the arithmetic mean height of the profile curve in the unit measurement interval (0.5 mm) of the nib is Pa, X derived from the following formula (i) is 0.1 MN/m to 100,000 MN/m, preferably 0.5 MN/m～80,000 MN/m. X (MN/m) = [E×D×D]/Pa (i) Furthermore, the unit of Young’s modulus E is “N/m ² ”, the unit of the diameter D of the nib is “m”, and the arithmetic mean The unit of height Pa is "m". Also, "M" means "mega (10 ⁶ )".

"Apparent Young's modulus E of the structure of the pen tip and shaft of the touch panel pen", "the diameter D of the pen tip" and "the arithmetic mean height Pa of the profile curve in the unit measurement interval (0.5 mm) of the pen tip" can be Measurement was performed by the same method as that described in Embodiment A.

Also, when X derived from the above formula (i) is in the above range, each value of Young's modulus E, diameter D, and arithmetic mean height Pa of the touch panel pen is preferably in a range substantially below. The Young's modulus is preferably 0.1 to 5.0 GPa (1.0×10 ⁸ to 5.0×10 ⁹ N/m ² ), more preferably 0.5 to 2.5 GPa (5.0×10 ⁸ to 2.5×10 ⁹ N/m ² ). The diameter D is preferably from 0.3 to 6.0 mm, more preferably from 0.4 to 2.0 mm. The arithmetic mean height Pa is preferably from 0.01 to 10 μm, more preferably from 0.05 to 1.0 μm. Also, the radius of curvature of the tip of the touch panel pen used in the determination of condition (C1) and the like is not particularly limited, but is preferably 0.3 to 1.5 mm, more preferably 0.5 to 0.8 mm.

In addition, as for the selection method of the writing sheet of Embodiment C, it is preferable to select a writing sheet whose haze according to JIS K7136:2000 satisfies the following condition (C3). ＜Condition (C3)＞ Haze is above 5.0%

By selecting writing sheets satisfying the condition (C3), writing sheets with good anti-glare property and good writing feeling can be efficiently selected. The haze is preferably at least 10.0%, more preferably at least 15.0%. Furthermore, if the haze is too high, the resolution of the display device will be greatly reduced. Therefore, the haze is preferably at most 40.0%, more preferably at most 30.0%. In the measurement of haze and clarity of transmitted image described below, light is incident from the surface of the writing sheet opposite to the writing surface. When both sides of the writing sheet satisfy the above-mentioned condition (C1), the light-incident side can be either side. The haze and transmission clarity are the average values obtained by measuring each of 20 samples once.

In addition, the selection method of the writing sheet of Embodiment C is preferably to select the width of the optical frequency comb of the image resolution measuring device to be measured in accordance with JIS K7374:2007 to be 0.125 mm, 0.5 mm, 1.0 mm and 2.0 mm When the clarity of the transmitted image is set to C _0.125 , C _0.5 , C _1.0 and C _2.0 , the sum C _s of C _0.125 , C _0.5 , C _1.0 and C _2.0 satisfies the following condition (C4). <Condition (C4)> C _s is 100% or more

By selecting a writing sheet that satisfies the condition (C4), it is possible to suppress a large decrease in the resolution of the display device. Furthermore, when C _s is too large, it may become difficult to satisfy the condition (C1) or the condition (C3). Therefore, the condition (C4) is more preferably 100% or more and less than 250% of C _s , more preferably 120% or more and 230% or less, still more preferably 150% or more and 200% or less.

[Writing sheet for touch panel pen] The writing sheet for touch panels of Embodiment C is what has the surface which satisfies the following condition (C1). ＜Condition (C1)＞ Fix the touch panel pen in contact with the surface of the writing sheet for the touch panel pen at an angle of 60 degrees, apply a vertical load of 100 gf to the touch panel pen, and scan 40 mm at a speed of 14 mm/sec in one pass Assuming that the kinetic friction coefficient acting in the scanning direction of the touch panel pen at this time is μk and the static friction coefficient is μs, μk/μs is not less than 0.30 and not more than 0.58.

Furthermore, even when the touch panel pen is fixed while touching the writing surface at an angle other than 60 degrees (for example, any angle in the range of 30 to 75 degrees), μk/μs is preferably within the above range. Also, even when the scanning speed is set to a speed other than 14 mm/sec (for example, any speed in the range of 0.1 to 100 mm/sec), it is preferable that μk/μs is in the above-mentioned range.

In the writing sheet of Embodiment C, μk of the writing surface preferably satisfies the following condition (C2). ＜Condition (C2)＞ 0.06≦μk≦0.30

In addition, in the writing sheet of Embodiment C, μs of the writing surface preferably satisfies the following condition (C2'). <Condition (C2')> 0.15≦μs≦0.95

The preferred ranges of the conditions (C1), (C2) and (C2') of the writing sheet of the embodiment C are the conditions (C1), (C2) and (C2') of the selection method of the writing sheet for the touch panel pen above. ) have the same preferred range.

Also, since the writing sheet of Embodiment C is easy to satisfy the conditions (C1), (C2) and (C2'), it is preferably used as X derived from the above formula (i) is 0.1 MN/m to 100,000 MN The writing sheet for a touch panel pen of /m is more preferably a writing sheet for a touch panel pen in which X derived from the above formula (i) is 0.5 MN/m to 80,000 MN/m. In addition, the values of Young's modulus E, diameter D, arithmetic mean height Pa, and radius of curvature of the pen tip of the touch panel pen are preferably within the above-mentioned ranges.

In addition, the writing sheet of Embodiment C preferably has a haze of JIS K7136:2000 satisfying the following condition (C3). ＜Condition (C3)＞ Haze is above 5.0%

In addition, the writing sheet of embodiment C is better for the clearness of the transmitted image when the width of the optical frequency comb of the image resolution measuring instrument measured in accordance with JIS K7374:2007 is 0.125 mm, 0.5 mm, 1.0 mm and 2.0 mm. When the degree is set to C _0.125 , C _0.5 , C _1.0 and C _2.0 , the sum C _s of C _0.125 , C _0.5 , C _1.0 and C _2.0 satisfies the following condition (C4). <Condition (C4)> C _s is 100% or more

The preferable ranges of the conditions (C3) and (C4) of the writing sheet of the embodiment C are the same as the preferable ranges of the conditions (C3) and (C4) of the above-mentioned selection method of the writing sheet for a touch panel pen.

In order to produce a writing sheet that satisfies the condition (C1), it is preferable to properly mix the unevenness of the high-frequency component (unevenness in a small area) and the unevenness of the low-frequency component (unevenness in a large area) on the writing surface. The difference between the unevenness of high-frequency components (unevenness in a small area) and the unevenness of low-frequency components (unevenness in a large area) will be described below. i In the stage where the pen is brought into contact with the writing sheet, the nib is grounded on the surface of the writing sheet. Therefore, it is considered that the start of writing is triggered when the pen tip passes over the convex part of the high-frequency component (micro region), and the unevenness of the micro region has a greater influence on the writing feeling at the beginning of writing. ii In the stage after starting to write, the nib moves along the concave-convex surface of a larger area. Therefore, the unevenness of a larger area has a greater influence on the writing feeling after starting writing. As mentioned above, the unevenness of a small area has a greater influence on the writing feeling at the beginning of writing, and the unevenness of a larger area has a greater influence on the writing feeling after the beginning of writing. Therefore, it is possible to improve the writing feeling by appropriately mixing the unevenness of the high-frequency component (unevenness in a small area) and the unevenness of the low-frequency component (unevenness in a large area) on the writing surface. Furthermore, when a touch panel pen with a large X derived from the above formula (i) is used, the tendency of the above (a) and (b) becomes stronger because it is difficult for the pen tip to be in close contact with the surface of the writing sheet. That is, when using a touch panel pen with a large X derived from the above formula (i), it is preferable to mix the unevenness of the high-frequency component and the unevenness of the low-frequency component on the writing surface of the writing sheet. Larger X means that X exceeds 500 MN/m, preferably X is 1,000 MN/m or more, and more preferably X is 2,000 MN/m or more and 100,000 MN/m or less.

＜The overall composition of the writing sheet＞ The composition of the writing sheet for a touch panel pen of Embodiment C is not particularly limited as long as at least one surface satisfies the condition (C1). For example, the configuration of the writing sheet 10 for a touch panel pen according to Embodiment C includes a resin layer 2 as shown in FIGS. 1 and 2 , and one surface of the resin layer 2 satisfies the condition (C1). Furthermore, although not shown in the figure, other layers other than the resin layer or the plastic film may also be provided, and the surface of the other layer satisfies the condition (C1). As another layer, an antistatic layer, an antifouling layer, etc. are mentioned. Moreover, although not shown in figure, the resin layer may consist of 2 or more layers.

The surface (writing surface) satisfying the condition (C1) can be formed by (a) physical or chemical treatment such as embossing, sandblasting, etching, (b) molding using a mold, (c) coating, etc. Among these methods, molding using a mold (b) is preferable from the viewpoint of surface shape reproducibility, and coating (c) is preferable from the viewpoint of productivity and compatibility with various varieties.

Regarding the formation of the resin layer by coating, it is possible to apply a resin layer forming coating liquid containing resin components, particles and solvents to the plastic film by known coating methods such as gravure coating and rod coating. on, dried and hardened. In order to make the resin layer formed by coating satisfy the condition (C1), it is preferable to use micron-sized particles and nano-sized inorganic ultrafine particles as particles, and set the film thickness, particle content and average particle size of the particles. within the following range.

The film thickness of the resin layer is preferably from 1.5 to 10 μm, more preferably from 2 to 8 μm, still more preferably from 4 to 7 μm. For example, the film thickness of the resin layer can be measured based on the image of the section taken by a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM). And figured out. The acceleration voltage of TEM or STEM is preferably set at 10-30 kV, and the magnification is preferably set at 50,000-300,000 times.

As the particles (micron-sized particles) of the resin layer, either organic particles or inorganic particles can be used. Examples of organic particles include polymethyl methacrylate, polyacrylic acid-styrene copolymer, melamine resin, polycarbonate, polystyrene, polyvinyl chloride, benzoguanamine-melamine-formaldehyde condensate, polysilicon Particles made of oxygen, fluorine-based resins, and polyester-based resins. Examples of the inorganic particles include particles made of silica, alumina, antimony, zirconia, and titania. Among these particles, organic particles are preferred from the viewpoint of ease of dispersion control. The content of particles (micron-sized particles) in the resin layer is preferably 2 to 25% by mass, more preferably 5 to 20% by mass, and still more preferably 10 to 15% by mass, of the total solid content forming the resin layer.

The average particle diameter of the particles (micron-sized particles) in the resin layer is preferably from 0.2 to 8.0 μm, more preferably from 0.3 to 7.0 μm, and still more preferably from 0.5 to 5.0 μm. In the case of particle aggregation, it is preferable that the average particle diameter of the aggregated particles satisfies the above-mentioned range. The average particle diameter of the particles can be calculated by the same method as in Embodiment A.

From the viewpoint of making the surface of the writing sheet satisfy the condition (C1), the film thickness of the resin layer is preferably larger than the average particle diameter of the particles (micron-sized particles). Specifically, the ratio of [average particle diameter of particles]/[film thickness of resin layer] is preferably 0.40 to 0.80, more preferably 0.45 to 0.75, and still more preferably 0.50 to 0.70.

Moreover, as particles, it is preferable to contain not only the above-mentioned micron-order particles but also nano-order inorganic ultrafine particles. By containing nanometer-order inorganic ultrafine particles, the surface of the resin layer can easily satisfy the condition (C1). The reason for this is considered to be that the unevenness of the high-frequency component (unevenness in a small area) is formed by micron-sized particles. On the other hand, when inorganic ultrafine particles are contained, the formation is relatively gentle in the place where micron-sized particles do not exist. The inclination of the low-frequency component forms the unevenness of the low-frequency component (the unevenness of the larger area), resulting in a shape in which the unevenness of the high-frequency component and the unevenness of the low-frequency component are mixed. In the case of containing inorganic ultrafine particles, the thixotropy of the coating liquid and the drying characteristics of the solvent are affected, and the usual leveling does not occur, so it is considered that the above-mentioned phenomenon will occur. As mentioned above, it is extremely effective for a touch panel pen with a large X derived from the above formula (i) to mix the unevenness of the high-frequency component and the unevenness of the low-frequency component. Also, by containing inorganic ultrafine particles, a gentler inclination is formed where there are no micron-sized particles, and as a result (resulting in a decrease in approximately smooth areas), the anti-glare property can also be improved.

Examples of inorganic ultrafine particles include ultrafine particles composed of silica, alumina, zirconia, and titania. Among these, silicon dioxide ultrafine particles are preferable from the viewpoint of transparency. The inorganic ultrafine particles preferably have an average primary particle diameter of 1 to 25 nm, more preferably 5 to 20 nm, from the viewpoint of easily obtaining the aforementioned uneven shape.

The inorganic ultrafine particles are preferably reactive inorganic ultrafine particles into which reactive groups are introduced by surface treatment. By introducing reactive groups, a large amount of inorganic ultrafine particles can be contained in the resin layer, and the surface shape of the writing sheet can be easily made within the above-mentioned range. As the reactive group, a polymerizable unsaturated group can be preferably used, preferably a photocurable unsaturated group, particularly preferably an ionizing radiation curable unsaturated group. Specific examples thereof include ethylenically unsaturated bonds such as (meth)acryl groups, (meth)acryloxy groups, vinyl groups, and allyl groups, epoxy groups, and the like. Such reactive inorganic ultrafine particles include inorganic ultrafine particles surface-treated with a silane coupling agent. When using a silane coupling agent to treat the surface of inorganic ultrafine particles, examples include: a dry method of spraying a silane coupling agent onto the inorganic ultrafine particles; or a method of dispersing the inorganic ultrafine particles in a solvent and then adding a silane coupling agent to react wet method, etc.

The content of the inorganic ultrafine particles is preferably 1 to 20% by mass, more preferably 2 to 15% by mass, and still more preferably 3 to 10% by mass of the total solid content forming the resin layer. By setting it as this range, it becomes easy to make the surface shape of a writing sheet into the said range by control of leveling property, and suppression of the polymerization shrinkage of a resin layer. Also, the ratio of the content of micron-sized particles and inorganic ultrafine particles in the resin layer (content of micron-sized particles/content of inorganic ultrafine particles) is preferable from the viewpoint of making it easy to make the surface shape of the writing sheet within the above-mentioned range. 1.0 to 3.0, more preferably 1.5 to 2.5.

The resin component of the resin layer preferably contains a thermosetting resin composition or a cured product of an ionizing radiation curable resin composition, and more preferably contains an ionizing radiation curable resin composition from the viewpoint of improving the mechanical strength. Among them, it is more preferable to include a cured product of 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 hardened by heating. Examples of the thermosetting resin 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 these curable resins 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)acryl, vinyl, and allyl groups, epoxy groups, oxetanyl groups, and the like. As the ionizing radiation curable compound, it is preferably a compound having an ethylenically unsaturated bonding group, more preferably a compound having two or more ethylenically unsaturated bonding groups, and among them, it is even more preferable to have two or more Polyfunctional (meth)acrylate compound of ethylenically unsaturated bond group. Both monomers and oligomers can be used as the polyfunctional (meth)acrylate compound. Furthermore, the so-called ionizing radiation refers to electromagnetic waves or charged particle beams that have energy quanta 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 polyfunctional (meth)acrylate compounds, examples of bifunctional (meth)acrylate monomers include ethylene glycol di(meth)acrylate, bisphenol A tetraethoxy diacrylate , bisphenol A tetrapropoxy diacrylate, 1,6-hexanediol diacrylate, etc. Examples of (meth)acrylate-based monomers having three or more functions include: trimethylolpropane tri(meth)acrylate, neopentylthritol tri(meth)acrylate, neopentylitol tetra(meth)acrylate, Meth)acrylate, diperythritol hexa(meth)acrylate, dipenteoerythritol tetra(meth)acrylate, isocyanuric acid modified tri(meth)acrylate, etc. In addition, the above-mentioned (meth)acrylate-based monomers can also be modified by modifying a part of the molecular skeleton, and can also be modified by ethylene oxide, propylene oxide, caprolactone, isocyanuric acid, alkyl, Modified by cyclic alkyl, aromatic, bisphenol, etc.

In addition, examples of polyfunctional (meth)acrylate oligomers include urethane (meth)acrylate, epoxy (meth)acrylate, polyester (meth)acrylate, polyether ( Acrylate-based polymers such as meth)acrylate, etc. Urethane (meth)acrylates can be obtained, for example, by reacting polyhydric alcohols and organic diisocyanates with hydroxy (meth)acrylates. In addition, preferred epoxy (meth)acrylates are obtained by reacting aromatic epoxy resins, cycloaliphatic epoxy resins, aliphatic epoxy resins, etc. with more than three functions with (meth)acrylic acid (meth)acrylic acid. (base) acrylates; (meth)acrylates obtained by reacting difunctional or higher aromatic epoxy resins, alicyclic epoxy resins, aliphatic epoxy resins, etc. with polybasic acids and (meth)acrylic acid; And (meth)acrylates obtained by reacting difunctional or higher aromatic epoxy resins, alicyclic epoxy resins, aliphatic epoxy resins, etc. with phenols and (meth)acrylic acid. The above ionizing radiation curable compounds may be used alone or in combination of two or more.

類等中之1種以上。 該等光聚合起始劑較佳為熔點為100℃以上。藉由將光聚合起始劑之熔點設為100℃以上，而於書寫片之製造過程、或觸控面板之透明導電膜之形成過程中所殘留之光聚合起始劑昇華，而可防止製造裝置或透明導電膜之污染。 又，光聚合促進劑係可減輕硬化時之由空氣引起之聚合抑制而使硬化速度加快者，例如可列舉：選自對二甲胺基苯基苯甲酸異戊酯、對二甲胺基苯甲酸乙酯等中之1種以上。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. Examples of photopolymerization initiators include: acetophenone, benzophenone, α-hydroxyalkylphenone, michelerone, benzoin, benzoyldimethylketal, benzoylbenzene Formic esters, α-acyl oxime esters, 9-oxothiol

One or more of the categories. These photopolymerization initiators preferably have a melting point of 100° C. or higher. By setting the melting point of the photopolymerization initiator at 100°C or higher, sublimation of the photopolymerization initiator remaining in the writing sheet manufacturing process or the formation process of the transparent conductive film of the touch panel can be prevented, thereby preventing production Contamination of the device or transparent conductive film. In addition, the photopolymerization accelerator can reduce the polymerization inhibition caused by air during hardening and accelerate the hardening speed, for example, it can be selected from isoamyl p-dimethylaminophenylbenzoate, p-dimethylaminophenyl One or more of ethyl formate and the like.

烷、四氫呋喃等）、脂肪族烴類（己烷等）、脂環式烴類（環己烷等）、芳香族烴類（甲苯、二甲苯等）、鹵化碳類（二氯甲烷、二氯乙烷等）、酯類（乙酸甲酯、乙酸乙酯、乙酸丁酯等）、醇類（丁醇、環己醇等）、溶纖劑類（甲基溶纖劑、乙基溶纖劑等）、乙酸溶纖劑類、亞碸類（二甲基亞碸等）、醯胺類（二甲基甲醯胺、二甲基乙醯胺等）等，亦可為該等之混合物。 於溶劑之乾燥過慢之情形時，樹脂層之整平性會變得過度，因此變得難以形成上述之表面形狀。因此，作為溶劑，較佳包含全部溶劑中之50質量%以上之蒸發速度（將乙酸正丁酯之蒸發速度設為100時之相對蒸發速度）為180以上之溶劑，更佳包含60質量%以上。作為相對蒸發速度為180以上之溶劑，可列舉：甲苯。甲苯之相對蒸發速度為195。In the coating liquid for forming a resin layer, a solvent is generally used to adjust the viscosity or to dissolve or disperse each component. Depending on the type of solvent, the surface state of the resin layer after the coating and drying process is different, so it is preferable to select the solvent by considering the saturated vapor pressure of the solvent, the permeability of the solvent to the transparent substrate, and the like. Specifically, examples of solvents include ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), ethers (di

alkane, tetrahydrofuran, etc.), aliphatic hydrocarbons (hexane, etc.), alicyclic hydrocarbons (cyclohexane, etc.), aromatic hydrocarbons (toluene, xylene, etc.), halocarbons (methylene chloride, dichloro ethane, etc.), esters (methyl acetate, ethyl acetate, butyl acetate, etc.), alcohols (butanol, cyclohexanol, etc.), cellosolves (methyl cellosolve, ethyl cellosolve etc.), acetic acid cellosolves, sulfides (dimethylsulfide, etc.), amides (dimethylformamide, dimethylacetamide, etc.), etc., or mixtures thereof. When the drying of the solvent is too slow, the leveling property of the resin layer becomes excessive, so it becomes difficult to form the above-mentioned surface shape. Therefore, as a solvent, it is preferable to contain 50% by mass or more of all solvents with an evaporation rate (relative evaporation rate when the evaporation rate of n-butyl acetate is 100) of 180 or more, more preferably 60% by mass or more. . Toluene is mentioned as a solvent whose relative evaporation rate is 180 or more. The relative evaporation rate of toluene is 195.

Moreover, it is preferable to contain a leveling agent in the coating liquid for forming a resin layer from the viewpoint of making the surface shape moderately smooth and making it easy to make the surface shape of the writing sheet within the above-mentioned range. Examples of leveling agents include fluorine-based leveling agents, silicone-based leveling agents, fluoropolysiloxane copolymer-based leveling agents, etc., preferably silicone-based leveling agents. The amount of the leveling agent added is preferably 0.01 to 0.5% by weight, more preferably 0.01 to 0.2% by weight, based on the total solid content of the resin layer forming coating liquid.

The plastic film can be made of polyester, triacetyl cellulose (TAC), cellulose diacetate, cellulose acetate butyrate, polyamide, polyimide, polyether, polyethylene, polypropylene, polymethylpentene , polyvinyl chloride, polyvinyl acetal, polyether ketone, polymethyl methacrylate, polycarbonate, polycarbonate and amorphous olefin (Cyclo-Olefin-Polymer: COP) and other resins. Among these plastic films, polyesters (polyethylene terephthalate, polyethylene naphthalate, polyethylene naphthalate) that have been stretched, especially biaxially stretched, are preferred from the standpoint of mechanical strength or dimensional stability. ester). The thickness of the plastic film is preferably 5-200 μm, more preferably 10-150 μm.

[touch panel] The touch panel of embodiment C is a touch panel having a sheet on the surface, and the side of the writing sheet for a touch panel pen of embodiment C of the sheet that satisfies the condition (C1) faces the surface of the touch panel configured in the same way.

Examples of the touch panel include resistive film touch panels, capacitive touch panels, in-cell touch panels, optical touch panels, ultrasonic wave touch panels, and electromagnetic induction touch panels.

The resistive film type touch panel 100 is, as shown in FIG. 3 , a configuration in which the conductive films 30 having a pair of transparent substrates 20 above and below the conductive film 30 face each other with spacers 40 interposed therebetween. It is a basic configuration, and a circuit not shown is connected to the basic configuration. In the case of a resistive film type touch panel, for example, the following configuration can be cited: using the writing sheet 10 of Embodiment C as the upper transparent substrate 20, and the surface of the writing sheet 10 satisfying the condition (C1) faces the touch panel. The surface of the panel 100 is used. Also, although not shown in the figure, the resistive film type touch panel may also be configured as follows: the writing sheet of Embodiment C is bonded on the upper transparent substrate so that the side that satisfies the condition (C1) faces the surface; or The writing sheet of Embodiment C is placed on the upper transparent substrate so that the side that satisfies the condition (C1) faces the surface, and fixed with a frame or the like.

The capacitive touch panel includes a surface type and a projection type, and the projection type is often used. The projection-type capacitive touch panel is formed by connecting a circuit to a basic structure in which an X-axis electrode and a Y-axis electrode perpendicular to the X-axis electrode are arranged through an insulator. If the basic structure is described in more detail, it can be listed as follows: Forming X-axis electrodes and Y-axis electrodes on different surfaces on a transparent substrate; Forming X-axis electrodes, an insulator layer, and Y-axis The state of the electrodes; as shown in FIG. 4, the X-axis electrode 50 is formed on the transparent substrate 20, the Y-axis electrode 60 is formed on the other transparent substrate 20, and the state of laminating through the insulator layer 70 such as an adhesive layer, etc. Furthermore, an aspect in which another transparent substrate is further laminated among these basic aspects can be mentioned. In the case of an electrostatic capacitive touch panel, for example, the following configuration can be cited: using the writing sheet 10 of Embodiment C as the transparent substrate 20 on the front side, and facing the side of the writing sheet 10 that satisfies the condition (C1) The surface of the touch panel 100 is used. Also, although not shown in the figure, the capacitive touch panel may also have a configuration in which the writing sheet of Embodiment C is attached to the transparent substrate on the front side so that the side that satisfies the condition (C1) faces the front surface. ; Or place the writing sheet of Embodiment C on the transparent substrate on the surface side so that the side that satisfies the condition (C1) faces the surface, and fix it with a frame or the like.

The electromagnetic induction touch panel is a touch panel using a special pen that generates a magnetic field. The electromagnetic induction type touch panel has at least a sensor part for detecting electromagnetic energy generated from the pen, and further has a transparent substrate on the sensor part. The transparent substrate can also be composed of multiple layers. In the case of an electromagnetic induction touch panel, for example, the following configuration can be cited: the writing sheet of Embodiment C is used as the outermost transparent substrate among the transparent substrates on the sensor portion, and the writing sheet satisfies the condition ( Use with the side of C1) facing the surface of the touch panel. Alternatively, in the case of an electromagnetic induction touch panel, it may also be configured as follows: on the outermost transparent substrate among the transparent substrates located on the sensor portion, the writing sheet of Embodiment C satisfying the condition (C1) The surface of the side facing the surface; or on the outermost transparent substrate, place the writing sheet of Embodiment C in such a way that the side of the side that satisfies the condition (C1) faces the surface, and use a frame, etc. fixed. The in-cell touch panel is one in which touch panel functions such as resistive film type, electrostatic capacitive type, and optical type are embedded in a liquid crystal element formed by sandwiching liquid crystal between two glass substrates. In the case of an in-cell touch panel, for example, a configuration in which the surface-facing glass substrate is bonded so that the side of the writing sheet of Embodiment C that satisfies the condition (C1) faces the surface is used. Furthermore, another layer, such as a polarizing plate, may be provided between the glass substrate on the surface side and the writing sheet of Embodiment C.

[Touch panel system] The touch panel system of Embodiment C is a touch panel system composed of a touch panel having a writing sheet for a touch panel pen on the surface and a touch panel pen, and satisfies the following condition (C1). ＜Condition (C1)＞ Fix the touch panel pen in contact with the surface of the writing sheet for the touch panel pen at an angle of 60 degrees, apply a vertical load of 100 gf to the touch panel pen, and scan 40 mm at a speed of 14 mm/sec in one pass Assuming that the kinetic friction coefficient acting in the scanning direction of the touch panel pen at this time is μk and the static friction coefficient is μs, μk/μs is not less than 0.30 and not more than 0.58.

Embodiments of the touch panel in the touch panel system of Embodiment C, the writing sheet for touch panel pens, and the touch panel pens include, for example: the selection method of the writing sheet for touch panel pens of the above-mentioned embodiment C , The writing sheet for a touch panel pen and the embodiment shown in the touch panel are the same. According to the touch panel system of the embodiment C, the writing feeling of the touch panel can be improved.

[display device] The display device of Embodiment C is a display device having a touch panel, and the touch panel is the touch panel of Embodiment C.

As a display element, a liquid crystal display element, an EL display element, a plasma display element, an electronic paper element, an in-cell touch panel liquid crystal display element, etc. are mentioned. When the display element is a liquid crystal display element, an EL display element, a plasma display element, or an electronic paper element, the touch panel of Embodiment C is mounted on these display elements. In the display device of the embodiment C, since the writing feeling becomes good without excessively damaging the surface, it is possible to suppress a large loss of the resolution of the display element. [Example]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

<Examples of Embodiment A> A1. Measurement and evaluation The following measurements and evaluations were performed on the writing sheets for touch panel pens produced in the examples and comparative examples. The results are shown in Table 1. A1-1. Surface Shape Measurement The writing sheets for touch panels of the examples and comparative examples were cut into 10 cm squares. The cutting parts are selected from random parts after visually confirming that there are no abnormal points such as dust or damage. Attach the cut surface member to a 10 cm long x 10 cm wide black board (manufactured by Kuraray, trade name: CosmoGrass) via an optically transparent adhesive sheet (refractive index: 1.47, thickness 100 μm) manufactured by Toray Corporation No.: DFA502K, thickness 2.0 mm) to obtain samples, prepare 20 samples. Using a surface roughness measuring device (Model: SE-3400/manufactured by Kosaka Laboratories Co., Ltd.), set it up so that the sample is fixed and in close contact with the measuring table, and use the following measurement conditions for the following For the measurement items described above, the surface shape of the resin layer side of each sample was measured. Then, the average value of 20 samples was set as Rz _0.8 , Rv _0.8 , S _2.5 , Ra _0.8 and Ptm of each example and comparative example. The results are shown in Table 1. <Measurement Conditions> [Style of Surface Roughness Measuring Unit] Kosaka Laboratories Co., Ltd. product name SE2555N (Tip curvature radius: 2 μm, apex angle: 90 degrees, material: diamond) [Measurement Conditions of Surface Roughness Measuring Device ] ・Evaluation length of Rz _0.8 , Rv _0.8 , S _2.5 and Ra _0.8 : 5 times the cut-off value λc ・Preliminary length of Rz _0.8 , Rv _0.8 , S _2.5 and Ra _0.8 : 2 times the cut-off value λc ・Conveying of the stylus Speed: 0.5 mm/s ・Vertical magnification: 2000 times ・Lateral magnification: 10 times ・Sliding skid: Not used (not in contact with the measurement surface) ・Cut-off filter type: Gaussian ・Dead band level: 10% ・tp/PC curve : Normal <measurement items> ・When the maximum height roughness of JIS B0601: 2001 with a cutoff value of 0.8 mm is set to Rz _0.8 , and the maximum valley depth of the roughness curve of JIS B0601: 2001 with a cutoff value of 0.8 mm is set to Rv _0.8 Rv _0.8 ／Rz _0.8・JIS B0601:1994 with a cut-off value of 2.5 mm, the average interval of local peaks S _2.5・JIS B0601:2001 with a cut-off value of 0.8 mm, the arithmetic mean roughness Ra _0.8・Set the unit measurement interval to 1 mm, Set the maximum value of the mountain height of the profile curve in the unit measurement interval as Pp, set the maximum value of the valley depth of the profile curve in the unit measurement interval as Pv, and set the sum of Pp and Pv as the maximum value of the profile curve in the unit measurement interval The average value Ptm of the Pt of the 5 measurement intervals at the profile height Pt. The cutoff value is 0.

A1-2. Prepare 20 samples each of the writing sheets for touch panels of the examples and comparative examples cut into 5 cm squares through image clarity. The 20 parts were selected from random parts after visually confirming that there were no abnormal points such as dust or damage. Using an image resolution measuring instrument (trade name: ICM-1T) manufactured by Suga Test Instruments, according to JIS K7374: 2000, 4 of optical frequency combs with passing widths of 0.125 mm, 0.5 mm, 1 mm and 2 mm for each sample One is measured through image sharpness, and the sum C _s is calculated. Then, the average value of 20 samples was made into the total sum _Cs of each Example and a comparative example. The light incident surface is set to the plastic film side.

A1-3. Haze Using a haze meter (HM-150, manufactured by Murakami Color Technology Laboratory), the haze (overall haze) of each sample produced in the above "A1-2" was measured in accordance with JIS K-7136:2000. Then, the average value of 20 samples was set as the haze of each Example and a comparative example. The light incident surface is set to the plastic film side.

A1-4. Coefficient of friction Using the product name HEIDON-14DR manufactured by Shinto Scientific Co., Ltd., the static friction coefficient (μs) and the dynamic friction coefficient (μk) were measured by the following method in the friction measurement mode of a certain load and one pass, and μk/μs was calculated. Each of the 20 samples was measured once to calculate the μk/μs of each sample, and the average value of the μk/μs of the 20 samples was used as the μk/μs of each example and comparative example. Regarding the environment during measurement, the temperature is set at 23°C±5°C, and the humidity is set at 50%±10%. The measurement interval of the coefficient of friction is set at 0.02 seconds. Furthermore, before the measurement starts, place each sample in an environment of 23°C±5°C and humidity of 50%±10% for more than 10 minutes. As shown in FIG. 7 , the following touch panel pen A1 or A2 was brought into contact with the surface of the resin layer side of the writing sheet for touch panel pen at an angle of 60 degrees, and fixed with a holder. A weight of 100 g is placed on the base of the upper part of the holder, and a vertical load of 100 gf is applied to the touch panel pen. With the load applied, move the movable table with the writing sheet fixed to the obtuse side of the angle formed by the movable table and the touch panel pen (left side in Figure 7) at a speed of 14 mm/s. The static friction coefficient (μs) and kinetic friction coefficient (μk) of the moving direction of the pen were measured when the length of one-way 40 mm was moved. If μk/μs is 0.30≦μk/μs≦0.58, it means that the balance between the coefficient of static friction and the coefficient of dynamic friction is good, and the writing feeling when starting to write after stopping writing for a while is good.

<Touch panel pen A1> Three-color ballpoint pen with touch pen (manufactured by Mitsubishi Pencil Co., Ltd., trade name: JETSTREAM nib); apparent Young’s modulus of the structure of the nib and shaft: 0.002 GPa (2.0×10 ⁶ N/m ² ); the diameter of the pen tip: 5 mm; the arithmetic mean height Pa of the section curve of the pen tip: 100 μm; X of the above formula (i): 0.5 MN/m <Touch panel pen A2> TOSHIBA CO., LTD. Manufacture, trade name: active electrostatic pen IPCZ131A; apparent Young's modulus of the structure of the pen tip and shaft: 1.5 GPa (1.5×10 ⁹ N/m ² ); the diameter of the pen tip: 1.6 mm; the arithmetic of the profile curve of the pen tip Average height Pa: 100 μm; X of the above formula (i): 38.4 MN/m

A1-5. Writing sense Attach the surface of the writing sheet for touch panel pens on the opposite side to the side of the resin layer to the glass plate via an optically transparent adhesive sheet (thickness 100 μm) manufactured by Toray Co., using the above touch panel pens A1 and A2, And evaluate the sense of writing. Those who have a good writing feeling at the beginning of writing and after the beginning of writing are set as 2 points; Those whose writing feeling is not good are set as 0 points, and are evaluated by 20 people. The average score of 20 people is 1.6 or more as A, 1.0 or more and less than 1.6 as B, and less than 1.0 as C. Regarding the environment during the evaluation, the temperature was set at 23°C±5°C, and the humidity was set at 50%±10%. Furthermore, each sample was placed in an environment at 23°C±5°C and humidity 50%±10% for more than 10 minutes before the evaluation started.

A2. Production of writing sheet for touch panel pen [Example A1] The first resin layer coating solution A1 of the following formulation was coated on a plastic film (PET film, thickness 80 μm) so that the thickness after drying was 3 μm, dried, and then irradiated with ultraviolet rays to form the first resin layer . Then, the second resin layer coating liquid A1 of the following formula was applied on the first resin layer in a manner that the thickness after drying was 2 μm, dried, and irradiated with ultraviolet rays to form the second resin layer, and obtained a touch Writing tablet for the control panel pen.

<First resin layer coating solution A1> ・Neopentylthritol Triacrylate                                                                                         (manufactured by Nippon Kayaku Co., Ltd., KAYARAD-PET-30) ・Urethane Acrylate (manufactured by Nippon Synthetic Chemicals, UV1700B) 72.8 parts ・Organic particles 8 servings (spherical polyacrylic acid-styrene copolymer, average particle size 5 μm) ・Amorphous silica 3 parts (average particle size 5 nm) ・Photopolymerization initiator                                                                                                             (manufactured by BASF Corporation, Irgacure184) ・Silicone-based leveling agent 0.2 parts (manufactured by Momentive High-tech Materials Co., Ltd., TSF4460) ・Solvent 1 (toluene) 80 parts ・Solvent 2 (cyclohexanone) 30 parts

<Second resin layer coating solution A1> ・Neopentylthritol Triacrylate 18 parts (manufactured by Nippon Kayaku Co., Ltd., KAYARAD-PET-30) ・Urethane Acrylate (manufactured by Nippon Synthetic Chemicals, UV1700B) 80 parts ・Photopolymerization initiator 3 parts (manufactured by BASF Corporation, Irgacure184) ・Silicone-based leveling agent 2 parts (manufactured by Momentive High-tech Materials Co., Ltd., TSF4460) ・Solvent 1 (methyl isobutyl ketone) 110 parts

[Example A2] Change the plastic film to TAC with a thickness of 40 μm, change the first resin layer coating solution A1 to the first resin layer coating solution A2 of the following formula, change the film thickness of the first resin layer to 6 μm, and change the first resin layer coating solution A2 to 6 μm. The second resin layer coating liquid A1 was changed to the second resin layer coating liquid A2 with the following formula, and the thickness of the second resin layer was changed to 0.1 μm. A touch panel was obtained in the same manner as in Example A1 Pen with writing tablet.

<First resin layer coating solution A2> ・Neopentylthritol triacrylate 17.9 parts (manufactured by Nippon Kayaku Co., Ltd., KAYARAD-PET-30) ・Urethane Acrylate (manufactured by Japan Synthetic Chemicals Co., UV1700B) 81.4 parts ・Fumed silica 0.5 parts (average primary particle size 10 nm) ・Photopolymerization initiator 3 parts (manufactured by BASF Corporation, Irgacure184) ・Silicone-based leveling agent 0.2 parts (manufactured by Momentive High-tech Materials Co., Ltd., TSF4460) ・Solvent 1 (methyl isobutyl ketone) 4 parts ・Solvent 2 (toluene) 160 parts ・Solvent 3 (cyclohexanone) 27 parts ・Solvent 4 (isopropanol) 63 parts

<Second resin layer coating solution A2> ・Neopentylthritol Triacrylate                                           (manufactured by Nippon Kayaku Co., Ltd., KAYARAD-PET-30) ・Urethane Acrylate (manufactured by Nippon Synthetic Chemicals, UV1700B) 43 parts ・Hollow silica 5 parts (average primary particle size 50 nm) ・Photopolymerization initiator 3 parts (manufactured by BASF Corporation, Irgacure184) ・Fluorine-based leveling agent 1 part (Manufactured by DIC Corporation, MEGAFACE RS-75) ・Solvent 1 (methyl isobutyl ketone) 135 parts ・Solvent 2 (methyl ethyl ketone) 232 parts ・Solvent 3 176 parts (Propylene Glycol Monomethyl Ether Acetate)

[Example A3] Change the plastic film to TAC with a thickness of 60 μm, change the first resin layer coating solution A1 to the first resin layer coating solution A3 of the following formula, and change the thickness of the first resin layer to 5 μm, otherwise , obtain the writing sheet for the touch panel pen in the same manner as in Example A2

<First resin layer coating solution A3> ・Neopentylthritol triacrylate 17.9 parts (manufactured by Nippon Kayaku Co., Ltd., KAYARAD-PET-30) ・Urethane Acrylate (manufactured by Nippon Synthetic Chemicals, UV1700B) 81.2 parts ・Fumed silica 0.7 parts (average primary particle size 10 nm) ・Photopolymerization initiators 3 parts (manufactured by BASF Corporation, Irgacure184) ・Fluorine leveling agent 0.2 parts (Manufactured by DIC Corporation, MEGAFACE RS-75) ・Solvent 1 (methyl isobutyl ketone) 4 parts ・Solvent 2 (toluene) 180 parts ・Solvent 3 (cyclohexanone) 30 parts ・Solvent 4 (isopropanol) 70 parts

[Comparative Example A1] Change the plastic film to TAC with a thickness of 80 μm, change the first resin layer coating solution A1 to the first resin layer coating solution A4 of the following formula, change the thickness of the first resin layer to 8 μm, and do not form Except for the second resin layer, a writing sheet for a touch panel pen was obtained in the same manner as in Example A1.

<First resin layer coating solution A4> ・Neopentylthritol Triacrylate 75 parts (manufactured by Nippon Kayaku Co., Ltd., KAYARAD-PET-30) ・Organic Particles 25 parts (spherical polyacrylic acid-styrene copolymer, average particle size 2 μm) ・Photopolymerization initiator 3 parts (manufactured by BASF Corporation, Irgacure184) ・Silicone-based leveling agent 0.001 parts (manufactured by Momentive High-tech Materials Co., Ltd., TSF4460) ・Solvent 1 (toluene) 40 parts ・Solvent 2 (cyclohexanone) 40 parts ・Solvent 3 40 parts (Propylene Glycol Monomethyl Ether Acetate)

[Comparative example A2] The first resin layer coating solution A1 was changed to the first resin layer coating solution A5 of the following formulation, the thickness of the first resin layer was changed to 3 μm, and the second resin layer was not formed. A writing sheet for a touch panel pen was obtained in the same manner as in Example A1.

<First resin layer coating solution A5> ・Neopentylthritol Triacrylate 93 parts (manufactured by Nippon Kayaku Co., Ltd., KAYARAD-PET-30) ・Inorganic microparticles 7 parts (Manufactured by Fuji Silesian Chemical Co., Ltd., gel method amorphous silica) (Hydrophobic treatment, average particle size (by laser diffraction scattering method) 4.1 μm) ・Photopolymerization initiator 5 parts (manufactured by BASF Corporation, Irgacure184) ・Silicone-based leveling agent 0.001 parts (TSF4460 manufactured by Momentive Advanced Materials) ・Solvent 1 (methyl isobutyl ketone) 30 parts ・Solvent 2 (methyl ethyl ketone) 30 parts ・Solvent 3 (isopropanol) 30 parts ・Solvent 4 (n-butanol) 30 parts

[Comparative Example A3] Change the plastic film to TAC with a thickness of 40 μm, change the first resin layer coating solution A1 to the first resin layer coating solution A6 of the following formula, change the thickness of the first resin layer to 5 μm, and do not form Except for the second resin layer, a writing sheet for a touch panel pen was obtained in the same manner as in Example A1. <First resin layer coating solution A6> ・Neopentylthritol Triacrylate 81 parts (manufactured by Nippon Kayaku Co., Ltd., KAYARAD-PET-30) ・Organic Particles 13 parts (spherical polyacrylic acid-styrene copolymer, average particle size 3.5 μm) ・Fumed silica 6 servings (average primary particle size 10 nm) ・Photopolymerization initiator 3 parts (manufactured by BASF Corporation, Irgacure184) ・Silicone-based leveling agent 0.001 parts (manufactured by Momentive High-tech Materials Co., Ltd., TSF4460) ・Solvent 1 (toluene) 30 parts ・Solvent 2 (cyclohexanone) 30 parts ・Solvent 3 (methyl isobutyl ketone) 30 parts ・Solvent 4 30 parts (Propylene Glycol Monomethyl Ether Acetate)

[Table 1] Table 1 Example A1 Example A2 Example A3 Comparative Example A1 Comparative Example A2 Comparative Example A3 surface shape Rv _0.8 ／Rz _0.8 0.40 0.45 0.44 0.40 0.31 0.38 S _2.5 (mm) 0.09 0.06 0.05 0.04 0.05 0.03 Ra _0.8 (μm) 0.09 0.12 0.08 0.10 0.41 0.14 Ptm (μm) 0.47 0.74 0.62 1.01 2.17 3.88 The sum of Cs through clarity (%) 329.9 289.2 353.2 211.7 17.7 154.1 Haze (%) 3.7 0.2 0.3 25.0 23.3 24.9 pen A1 μk/μs 0.47 0.43 0.45 0.47 0.73 0.53 writing sense A A B C C C pen A2 μk/μs 0.43 0.43 0.44 0.51 0.42 0.27 writing sense A A A B B C

From the results in Table 1, it is clear that the writing sheets for touch panel pens of Examples A1 to A3 automatically use the touch panel pen whose X value of the above formula (i) is 500 MN/m or less as the touch panel pen. The writing feeling from the start of writing to the end of writing was good. Also, the writing sheets for touch panel pens of Examples A1 to A3 are because μk/μs is 0.30≦μk/μs≦0.58, so the balance between the coefficient of static friction and the coefficient of dynamic friction is good, and when writing is stopped for a while and then started writing Those who have a good sense of writing.

A3. Production of touch panel An ITO conductive film with a thickness of 20 nm was formed on the substrate side of the writing sheets for touch panel pens of Examples A1-A3 and Comparative Examples A1-A3 by sputtering to form an upper electrode plate. Next, a conductive film of ITO with a thickness of about 20 nm was formed on one side of a tempered glass plate with a thickness of 1 mm by sputtering to form a lower electrode plate. Next, ionizing radiation-curable resin (Dot Cure TR5903: Sun Ink Co., Ltd.) as a coating liquid for spacers is printed in dots on the surface of the conductive film with the lower electrode plate by screen printing, and then the A 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. Next, the upper electrode plate and the lower electrode plate were arranged so that the conductive films faced each other, and the edges were bonded with a double-sided tape with a thickness of 30 μm and a width of 3 mm to prepare Examples A1 to A3 and Comparative Example A1. ~ A3 resistive film touch panel. The above-mentioned touch panel pens A1-A2 were used to write on the resistive film touch panels of Examples A1-A3 and Comparative Examples A1-A3, and the evaluation of the writing feeling of each touch panel pen was the same as in Table 1. Also, the resistive film touch panels of Examples A1-A3 and Comparative Examples A1-A3 were mounted on a commercially available ultra-high-definition liquid crystal display device (smartphone manufactured by Sharp, product name: SH-03G, pixel density 480 On ppi), the images were evaluated visually. As a result, the touch panels of Examples A1 to A3 were those that could suppress the decrease in resolution of ultra-high-definition display elements. On the other hand, the touch panels of Comparative Examples A1 to A3 were unable to suppress the decrease in the resolution of the ultra-high-definition display element.

A4. Manufacture of display device The writing sheets for touch panel pens of Examples A1-A3 and Comparative Examples A1-A3 and a commercially available ultra-high-definition liquid crystal display device (smartphone manufactured by Sharp, product name: SH-03G, pixel density 480 ppi) were passed through A transparent adhesive (an optically transparent adhesive sheet manufactured by Toray Corporation, with a thickness of 100 μm) was bonded together to manufacture the display devices of Examples A1-A3 and Comparative Examples A1-A3. In addition, when bonding, the surface of the writing sheet base material side for touch panel pens faces the display element side. The above-mentioned touch panel pens A1-A2 were used to write on the display devices of Examples A1-A3 and Comparative Examples A1-A3, and the evaluation of the writing feeling of each touch panel pen was the same as in Table 1. In addition, the images of the display devices of Examples A1-A3 and Comparative Examples A1-A3 were evaluated visually. As a result, the display devices of Examples A1-A3 can suppress the resolution reduction of ultra-high-definition display elements. On the other hand, the display devices of Comparative Examples A1 to A3 were unable to suppress the decrease in the resolution of the ultra-high-definition display elements.

[Reference example A1～A6] For the writing sheets for touch panel pens produced in Examples A1 to A3 and Comparative Examples A1 to A3, the following touch panel pen A3 was used, and the measurement of μk/μs and the evaluation of writing feeling were performed by the same method as above . The results are shown in Table 2.

<Touch panel pen A3> Made by Adonit Corporation, trade name: Jot Mini; apparent Young's modulus of the structure of the pen tip and shaft: 0.1 GPa (1.0×10 ⁸ N/m ² ); diameter of the pen tip: 5.0 mm ;Arithmetic mean height Pa of the section curve of the nib: 1.0 μm; X of the above formula (i): 2,500 MN/m

[Table 2] Table 2 Reference example A1 Reference example A2 Reference example A3 Reference example A4 Reference example A5 Reference example A6 pen A3 μk/μs 0.49 0.48 0.49 0.49 0.42 0.52 writing sense C B C C B C

From the results in Table 2, it can be confirmed that the writing sheets for touch panel pens of Examples A1 to A3 have a touch panel pen (pen A3) whose X value exceeds 500 MN/m in the above formula (i) as the touch panel. When the pen is controlled, the writing feeling is not good. In addition, from the results of Table 1 and Table 2, it can be confirmed that the writing sheet for a touch panel pen satisfying the conditions (A1) and (A2) is not suitable for touch with the X value of the above formula (i) exceeding 500 MN/m Writing sheets for panel pens (pens that are difficult to adhere to writing sheets), on the other hand, suitable for writing on touch panel pens (pens that are easy to adhere to writing sheets) where the X value of the above formula (i) is 500 MN/m or less piece.

<Examples of Embodiment B> B1. Measurement and evaluation The following measurements and evaluations were performed on the writing sheets for touch panel pens produced in the examples and comparative examples. The results are shown in Table 3. B1-1. Measurement of Surface Shape The writing sheets for touch panels of Examples and Comparative Examples were cut into 10 cm squares. The cutting parts are selected from random parts after visually confirming that there are no abnormal points such as dust or damage. Attach the cut surface member to a 10 cm long x 10 cm wide black board (manufactured by Kuraray, trade name: CosmoGrass) via an optically transparent adhesive sheet (refractive index: 1.47, thickness 100 μm) manufactured by Toray Corporation No.: DFA502K, thickness 2.0 mm) to obtain samples, prepare 20 samples. Using a surface roughness measuring device (Model: SE-3400/manufactured by Kosaka Laboratories Co., Ltd.), set it up so that the sample is fixed and in close contact with the measuring table, and use the following measurement conditions for the following For the measurement items described above, the surface shape of the resin layer side of each sample was measured. Then, the average value of 20 samples was set as Rz _0.8 , Rp _0.8 , Psk, Ptm, S _2.5 and Ra _0.8 of each example and comparative example. The results are shown in Table 3. <Measurement Conditions> [Style of Surface Roughness Measuring Unit] Kosaka Laboratories Co., Ltd. product name SE2555N (Tip curvature radius: 2 μm, apex angle: 90 degrees, material: diamond) [Measurement Conditions of Surface Roughness Measuring Device ] ・Evaluation length of Rz _0.8 , Rp _0.8 , S _2.5 and Ra _0.8 : 5 times the cut-off value λc ・Preparation length of Rz _0.8 , Rp _0.8 , S _2.5 and Ra _0.8 : 2 times the cut-off value λc ・Conveying of the stylus Speed: 0.5 mm/s ・Vertical magnification: 2000 times ・Lateral magnification: 10 times ・Sliding skid: Not used (not in contact with the measurement surface) ・Cut-off filter type: Gaussian ・Dead band level: 10% ・tp/PC curve : Normal <measurement items> ・Set the maximum height roughness of JIS B0601: 2001 with a cut-off value of 0.8 mm to Rz _0.8 , and set the maximum height of the roughness curve of JIS B0601: 2001 with a cut-off value of 0.8 mm to Rp _0.8 Rp _0.8 ／Rz _0.8・Skewness Psk of the profile curve in the measurement interval 1 mm. The cutoff value is 0.・Set the unit measurement interval to 1 mm, set the maximum value of the mountain height of the profile curve in the unit measurement interval to Pp, set the maximum value of the valley depth of the profile curve in the unit measurement interval to Pv, and set the sum of Pp and Pv to It is the average value Ptm of Pt in the 5 measurement intervals when the maximum profile height Pt of the profile curve in the unit measurement interval. The cutoff value is 0.・JIS B0601: 1994 with a cut-off value of 2.5 mm, the average interval S of local peaks is _2.5・JIS B0601: 2001 with a cut-off value of 0.8 mm, the arithmetic mean roughness Ra _0.8

B1-2. Haze 20 samples were prepared by cutting the writing sheets for touch panels of Examples and Comparative Examples into 5 cm squares. The 20 parts were selected from random parts after visually confirming that there were no abnormal points such as dust or damage. The haze (overall haze) of each sample was measured in accordance with JIS K-7136:2000 using a haze meter (HM-150, manufactured by Murakami Color Technology Laboratory). Then, the average value of 20 samples was set as the haze of each Example and a comparative example. The light incident surface is set to the plastic film side.

B1-3. Through the image definition, use the image resolution measuring instrument (trade name: ICM-1T) manufactured by Suga Test Instruments, according to JIS K7374: 2000 for each sample prepared in the above "B1-2" Measure through 4 types of transmission image clarity of optical frequency combs with widths of 0.125 mm, 0.5 mm, 1 mm and 2 mm, and calculate the sum C _s . Then, the average value of 20 samples was made into the total sum _Cs of each Example and a comparative example. The light incident surface is set to the plastic film side.

B1-4. Coefficient of friction Using the product name HEIDON-14DR manufactured by Shinto Scientific Co., Ltd., the static friction coefficient (μs) and the dynamic friction coefficient (μk) were measured by the following method in the friction measurement mode of a certain load and one pass, and μk/μs was calculated. Each of the 20 samples was measured once to calculate the μk/μs of each sample, and the average value of the μk/μs of the 20 samples was used as the μk/μs of each example and comparative example. Regarding the environment during measurement, the temperature is set at 23°C±5°C, and the humidity is set at 50%±10%. The measurement interval of the coefficient of friction is set at 0.02 seconds. Furthermore, before the measurement starts, place each sample in an environment of 23°C±5°C and humidity of 50%±10% for more than 10 minutes. As shown in FIG. 7 , the following touch panel pen B1 or B2 was brought into contact with the surface of the resin layer side of the writing sheet for touch panel pen at an angle of 60 degrees, and fixed with a holder. A weight of 100 g is placed on the base of the upper part of the holder, and a vertical load of 100 gf is applied to the touch panel pen. With the load applied, move the movable table with the writing sheet fixed to the obtuse side of the angle formed by the movable table and the touch panel pen (left side in Figure 7) at a speed of 14 mm/s. The static friction coefficient (μs) and kinetic friction coefficient (μk) of the moving direction of the pen were measured when the length of one-way 40 mm was moved. If μk/μs is 0.30≦μk/μs≦0.58, it means that the balance between the coefficient of static friction and the coefficient of dynamic friction is good, and the writing feeling when starting to write after stopping writing for a while is good.

<Touch panel pen B1> Product name "S Pen SCL24KKA" manufactured by Samsung Electronics Co., Ltd.; apparent Young's modulus of the structure of the pen tip and shaft: 1.0 GPa (1.0×10 ⁹ N/m ² ); diameter of the pen tip : 0.5 mm; Arithmetic mean height Pa of the profile curve of the pen tip: 0.1 μm; X of the above formula (i): 2,500 MN/m -004"; the apparent Young's modulus of the nib and shaft structure: 2.0 GPa (2.0×10 ⁹ N/m ² ); the diameter of the nib: 2.0 mm; the arithmetic mean height Pa of the section curve of the nib: 0.1 μm ; X of the above formula (i): 80,000 MN/m

B1-5. Writing sense Attach the surface of the writing sheet for touch panel pens opposite to the side of the resin layer to the glass plate via an optically transparent adhesive sheet (thickness 100 μm) manufactured by Toray Corporation, and use the above touch panel pens B1 and B2, And evaluate the sense of writing. Those who have a good writing feeling at the beginning of writing and after the beginning of writing are set as 2 points; Those whose writing feeling is not good are set as 0 points, and are evaluated by 20 people. The average score of 20 people is 1.6 or more as A, 1.0 or more and less than 1.6 as B, and less than 1.0 as C. Regarding the environment during the evaluation, the temperature was set at 23°C±5°C, and the humidity was set at 50%±10%. Furthermore, each sample was placed in an environment at 23°C±5°C and humidity 50%±10% for more than 10 minutes before the evaluation started.

B1-6. Anti-glare When evaluating the writing feeling of B1-5 under the illumination of fluorescent lamps (brightness of the writing surface: 500 lux), the person who does not care about the reflection of the illumination is set as 2 points, and the illumination is slightly reflected but not One point was set for a person who was impaired in writing, and one point was set for a person who was obstructed by a strong illumination, and 0 points were used for evaluation by 20 persons. The average score of 20 people is 1.6 or more as A, 1.0 or more but less than 1.6 is B, and less than 1.0 is C.

B2. Production of writing sheet for touch panel pen [Example B1] Resin layer coating liquid B1 of the following formulation was coated on a plastic film (triacetyl cellulose resin film with a thickness of 40 μm) so that the thickness after drying was 5 μm, dried, and then irradiated with ultraviolet rays to form a resin layer , and get a writing tablet for a touch panel pen.

<Resin layer coating solution B1> ・Neopentylthritol Triacrylate 81 parts (manufactured by Nippon Kayaku Co., Ltd., KAYARAD-PET-30) ・Organic Particles 13 parts (spherical polyacrylic acid-styrene copolymer, average particle size 3.5 μm) ・Fumed silica 6 servings (average primary particle size 10 nm) ・Photopolymerization initiator 3 parts (manufactured by BASF Corporation, Irgacure184) ・Silicone-based leveling agent 0.001 parts (manufactured by Momentive High-tech Materials Co., Ltd., TSF4460) ・Solvent 1 (toluene) 180 parts ・Solvent 2 (cyclohexanone) 70 parts ・Solvent 3 (methyl isobutyl ketone) 2 parts ・Solvent 4 28 parts (Propylene Glycol Monomethyl Ether Acetate)

[Example B2] The resin layer coating liquid B1 was changed to the resin layer coating liquid B2 of the following formulation, except that the thickness of the resin layer was changed to 7 μm, and a writing sheet for a touch panel pen was obtained in the same manner as in Example B1 .

<Resin layer coating solution B2> ・Neopentylthritol Triacrylate 83 parts (manufactured by Nippon Kayaku Co., Ltd., KAYARAD-PET-30) ・Organic Particles 11 parts (spherical polystyrene, average particle size 3.5 μm) ・Fumed silica 7 servings (average primary particle size 10 nm) ・Photopolymerization initiator 3 parts (manufactured by BASF Corporation, Irgacure184) ・Silicone-based leveling agent 0.125 parts (manufactured by Momentive High-tech Materials Co., Ltd., TSF4460) ・Solvent 1 (toluene) 225 parts ・Solvent 2 (cyclohexanone) 3 parts ・Solvent 3 (methyl isobutyl ketone) 50 parts ・Solvent 4 (isopropanol) 28 parts

[Comparative Example B1] Change the resin layer coating liquid B1 to the resin layer coating liquid B3 of the following formulation, change the thickness of the resin layer to 6 μm, and change the thickness of the second resin layer coating liquid B1 of the following formulation to be 0.1 μm method is coated on the resin layer and dried, and the second resin layer is irradiated with ultraviolet rays to obtain a writing sheet for a touch panel pen.

<Resin layer coating solution B3> ・ 17.9 copies of triglycerite with pentaoliol (manufactured by Nippon Kayaku Co., Ltd., KAYARAD-PET-30) ・Urethane Acrylate (manufactured by Japan Synthetic Chemicals Co., UV1700B) 81.4 parts ・Fumed silica 0.5 parts (average primary particle size 10 nm) ・Photopolymerization initiator 3 parts (manufactured by BASF Corporation, Irgacure184) ・Silicone-based leveling agent 0.2 parts (manufactured by Momentive High-tech Materials Co., Ltd., TSF4460) ・Solvent 1 (methyl isobutyl ketone) 4 parts ・Solvent 2 (toluene) 160 parts ・Solvent 3 (cyclohexanone) 27 parts ・Solvent 4 (isopropanol) 63 parts

<Second resin layer coating solution B1> ・Neopentylthritol Triacrylate                                           (manufactured by Nippon Kayaku Co., Ltd., KAYARAD-PET-30) ・Urethane Acrylate (manufactured by Nippon Synthetic Chemicals, UV1700B) 43 parts ・Hollow silica 5 parts (average primary particle size 50 nm) ・Photopolymerization initiator 3 parts (manufactured by BASF Corporation, Irgacure184) ・Fluorine-based leveling agent 1 part (Manufactured by DIC Corporation, MEGAFACE RS-75) ・Solvent 1 (methyl isobutyl ketone) 135 parts ・Solvent 2 (methyl ethyl ketone) 232 parts ・Solvent 3 176 parts (Propylene Glycol Monomethyl Ether Acetate)

[Comparative Example B2] The resin layer coating liquid B1 was changed to the resin layer coating liquid B4 of the following formulation, except that the thickness of the resin layer was changed to 3 μm, and a writing sheet for a touch panel pen was obtained in the same manner as in Example B1 . <Resin layer coating solution B4> ・Neopentylthritol Triacrylate 93 parts (manufactured by Nippon Kayaku Co., Ltd., KAYARAD-PET-30) ・Inorganic microparticles 5 parts (Manufactured by Fuji Silesian Chemical Co., Ltd., gel method amorphous silica) (Hydrophobic treatment, average particle size (by laser diffraction scattering method) 4.1 μm) ・Photopolymerization initiator 5 parts (manufactured by BASF Corporation, Irgacure184) ・Silicone-based leveling agent 0.001 parts (TSF4460 manufactured by Momentive Advanced Materials) ・Solvent 1 (methyl isobutyl ketone) 30 parts ・Solvent 2 (methyl ethyl ketone) 30 parts ・Solvent 3 (isopropanol) 30 parts ・Solvent 4 (n-butanol) 30 parts

[table 3] table 3 Example B1 Example B2 Comparative Example B1 Comparative Example B2 surface shape Rp _0.8 ／Rz _0.8 0.62 0.61 0.55 0.78 Psk (μm) 1.27 0.96 0.44 0.83 Ptm (μm) 3.88 1.26 0.74 3.23 S _2.5 (mm) 0.03 0.11 0.06 0.04 Ra _0.8 (μm) 0.14 0.39 0.12 0.13 Rz _JIS0.8 (μm) 0.66 0.85 0.44 1.71 Haze (%) 24.9 39.3 0.2 20.7 The sum of Cs through clarity (%) 154.1 196.6 289.2 24.2 pen B1 μk/μs 0.42 0.36 0.55 0.60 writing sense A A C C pen B2 μk/μs 0.41 0.43 0.41 0.45 writing sense A A B B Anti-glare A A C B

From the results in Table 3, it is clear that the writing sheets for touch panel pens of Examples B1 to B2, when using the touch panel pen whose X value of the above formula (i) exceeds 500 MN/m as the touch panel pen, from the beginning The writing feeling from writing to the end of writing was good. Also, the writing sheets for touch panel pens of Examples B1-B2 are because μk/μs is 0.30≦μk/μs≦0.58, so the balance between the coefficient of static friction and the coefficient of dynamic friction is good, and when writing is stopped for a while and then started writing Those who have a good sense of writing. Moreover, the writing sheet for touch panel pens of Examples B1-B2 was also excellent in antiglare property.

B3. Production of touch panel An ITO conductive film with a thickness of 20 nm was formed on the substrate side of the writing sheet for touch panel pens of Examples B1-B2 and Comparative Examples B1-B2 by sputtering to form an upper electrode plate. Next, a conductive film of ITO with a thickness of about 20 nm was formed on one side of a tempered glass plate with a thickness of 1 mm by sputtering to form a lower electrode plate. Next, ionizing radiation-curable resin (Dot Cure TR5903: Sun Ink Co., Ltd.) as a coating liquid for spacers is printed in dots on the surface of the conductive film with the lower electrode plate by screen printing, and then the A 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. Next, the upper electrode plate and the lower electrode plate were arranged so that the conductive films faced each other, and the edges were bonded with a double-sided tape with a thickness of 30 μm and a width of 3 mm to prepare Examples B1 to B2 and Comparative Example B1. ~ B2 resistive film touch panel. The above-mentioned touch panel pens B1-B2 were used to write on the resistive film touch panels of Examples B1-B2 and Comparative Examples B1-B2, and the evaluation of the writing feeling of each touch panel pen was the same as in Table 3. Also, the resistive film type touch panels of Examples B1-B2 and Comparative Examples B1-B2 were mounted on a commercially available ultra-high-definition liquid crystal display device (Smartphone manufactured by Sharp, product name: SH-03G, pixel density 480 On ppi), the images were evaluated visually under fluorescent lighting. As a result, the touch panels of Examples B1 to B2 were superior in anti-glare performance compared to the touch panel of Comparative Example B1, and compared with the touch panel of Comparative Example B2. Compared with the panel, it can suppress the reduction of the resolution of the ultra-high-definition display element.

B4. Manufacture of display device The writing sheets for touch panel pens of Examples B1-B2 and Comparative Examples B1-B2 were connected to a commercially available ultra-high-definition liquid crystal display device (smartphone manufactured by Sharp, product name: SH-03G, pixel density 480ppi) through a transparent Adhesives were bonded together to manufacture the display devices of Examples B1-B2 and Comparative Examples B1-B2. In addition, when bonding, the surface of the writing sheet base material side for touch panel pens faces the display element side. Using the above-mentioned touch panel pens B1-B2 to write on the display devices of Examples B1-B2 and Comparative Examples B1-B2, the evaluation of the writing feeling of each touch panel pen is the same as Table 3. In addition, the images of the display devices of Examples B1-B2 and Comparative Examples B1-B2 were visually evaluated under fluorescent lighting (brightness of the evaluation surface: 500 lux), and the results showed that the display devices of Examples B1-B2 The anti-glare property is better than that of the display device of Comparative Example B1, and compared with the display device of Comparative Example B2, the resolution reduction of ultra-high-definition display elements can be suppressed.

[Reference example B1 to B4] For the writing sheets for touch panel pens produced in Examples B1 to B2 and Comparative Examples B1 to B2, the following touch panel pen B3 was used, and the measurement of μk/μs and the evaluation of writing feeling were performed by the same method as above . The results are shown in Table 4.

<Touch panel pen B3> 3-color ballpoint pen with touch pen (manufactured by Mitsubishi Pencil Co., Ltd., trade name: JETSTREAM nib); apparent Young’s modulus of the structure of the nib and shaft: 0.002 GPa (2.0×10 ⁶ N/m ² ); the diameter of the nib: 5.0 mm; the arithmetic average height Pa of the section curve of the nib: 100 μm; X of the above formula (i): 0.5 MN/m

[Table 4] Table 4 Reference example B1 Reference example B2 Reference example B3 Reference example B4 pen B3 μk/μs 0.53 0.48 0.43 0.55 writing sense C B A C

From the results in Table 4, it can be confirmed that the writing sheets for touch panel pens of Examples B1 to B2 have a touch panel pen (pen B3) whose X value in the above formula (i) is 500 MN/m or less. When using the touch panel pen, the writing feeling tends not to be good. Also, from the results of Table 3 and Table 4, it can be confirmed that the writing sheet for a touch panel pen that satisfies the conditions (B1) and (B2) is not suitable for the touch panel whose X value in the above formula (i) is 500 MN/m or less. A writing sheet for a control panel pen (a pen that is easy to adhere to a writing sheet), on the other hand, suitable for writing on a touch panel pen (a pen that is difficult to adhere to a writing sheet) where the X value of the above formula (i) exceeds 500 MN/m piece.

<Example of Embodiment C> C1. Measurement and evaluation The following measurement and evaluation were performed about the writing sheet for touch panel pens produced in the Example and the comparative example. The results are shown in Table 5 or Table 6.

C1-1. Coefficient of friction Using the product name HEIDON-14DR manufactured by Shinto Scientific Co., Ltd., the static friction coefficient (μs) and the dynamic friction coefficient (μk) were measured by the following method in the friction measurement mode of a certain load and one pass, and μk/μs was calculated. The average value when measuring each 20 samples once was made into μk and μs of each Example and Comparative Example. In addition, each of the 20 samples was measured once to calculate the μk/μs of each sample, and the average value of the μk/μs of the 20 samples was used as the μk/μs of each example and comparative example. Regarding the environment during measurement, the temperature is set at 23°C±5°C, and the humidity is set at 50%±10%. The measurement interval of the coefficient of friction is set at 0.02 seconds. Furthermore, before the measurement starts, place each sample in an environment of 23°C±5°C and humidity of 50%±10% for more than 10 minutes. As shown in FIG. 7 , the following touch panel pens C1 to C4 were brought into contact with the surface of the resin layer side of the writing sheet for touch panel pens at an angle of 60 degrees, and fixed with a holder. A weight of 100 g is placed on the base of the upper part of the holder, and a vertical load of 100 gf is applied to the touch panel pen. With the load applied, move the movable table with the writing sheet fixed to the obtuse side of the angle formed by the movable table and the touch panel pen (left side in Figure 7) at a speed of 14 mm/s. The coefficient of static friction (μs) and coefficient of kinetic friction (μk) of the pen in the scanning direction were measured when the length of one-way 40 mm was scanned.

＜Touch panel pen C1＞ The product name "S Pen SCL24KKA" manufactured by Samsung Electronics Co., Ltd.; the apparent Young's modulus of the structure of the pen tip and the shaft: 1.0 GPa (1.0×10 ⁹ N/m ² ); the diameter of the pen tip : 0.5 mm; Arithmetic mean height Pa of the profile curve of the pen tip: 0.1 μm; X of the above formula (i): 2,500 MN/m -004"; the apparent Young's modulus of the nib and shaft structure: 2.0 GPa (2.0×10 ⁹ N/m ² ); the diameter of the nib: 2.0 mm; the arithmetic mean height Pa of the section curve of the nib: 0.1 μm ; X in the above formula (i): 80,000 MN/m <Touch panel pen C3> Three-color ballpoint pen with touch pen (manufactured by Mitsubishi Pencil Co., Ltd., trade name: JETSTREAM nib); Apparent Young's modulus: 0.002 GPa (2.0×10 ⁶ N/m ² ); diameter of the nib: 5.0 mm; arithmetic average height Pa of the section curve of the nib: 100 μm; X of the above formula (i): 0.5 MN /m <Touch panel pen C4> Manufactured by Toshiba Co., Ltd., trade name: active electrostatic pen IPCZ131A; apparent Young's modulus of the pen tip and shaft structure: 1.5 GPa (1.5×10 ⁹ N/m ² ); The diameter of the nib: 1.6 mm; the arithmetic mean height Pa of the section curve of the nib: 100 μm; the X of the above formula (i): 38.4 MN/m

C1-2. Writing sense Attach the surface of the writing sheet for touch panel pens opposite to the side of the resin layer to the glass plate via an optically transparent adhesive sheet (thickness 100 μm) manufactured by Toray Corporation, and use the above touch panel pens C1 to C4, And evaluate the sense of writing. The following 3 kinds of writing feeling, that is, the writing feeling when starting to write, the writing feeling after starting to write, and the writing feeling when starting to write after stopping writing for a moment, were set as evaluation points, and the writing feeling as a whole was set as 2 20 people made evaluations by assigning 1 point to those whose overall writing feeling was average, and setting 0 points to those whose overall writing feeling was not good. The average score of 20 people is 1.6 or more as A, 1.0 or more and less than 1.6 as B, and less than 1.0 as C. Regarding the environment during the evaluation, the temperature was set at 23°C±5°C, and the humidity was set at 50%±10%. Furthermore, each sample was placed in an environment at 23°C±5°C and humidity 50%±10% for more than 10 minutes before the evaluation started.

C1-3. Haze 20 samples were prepared by cutting the writing sheets for touch panels of Examples and Comparative Examples into 5 cm squares. The 20 parts were selected from random parts after visually confirming that there were no abnormal points such as dust or damage. The haze (overall haze) of each sample was measured in accordance with JIS K-7136:2000 using a haze meter (HM-150, manufactured by Murakami Color Technology Laboratory). Then, the average value of 20 samples was set as the haze of each Example and a comparative example. The light incident surface is set to the plastic film side.

C1-4. Through the image definition, use the image resolution measuring instrument (trade name: ICM-1T) manufactured by Suga Test Instruments, according to JIS K7374: 2000 for each sample prepared in the above "C1-3" Measure through 4 types of transmission image clarity of optical frequency combs with widths of 0.125 mm, 0.5 mm, 1 mm and 2 mm, and calculate the sum C _s . Then, the average value of 20 samples was made into the total sum _Cs of each Example and a comparative example. The light incident surface is set to the plastic film side.

C1-5. Anti-glare When evaluating the writing feeling of C1-2 under the illumination of fluorescent lamps (brightness of the writing surface: 500 lux), the person who does not care about the reflection of the illumination is set as 2 points, and the illumination is slightly reflected but not One point was set for a person who was impaired in writing, and one point was set for a person who was obstructed by a strong illumination, and 0 points were used for evaluation by 20 persons. The average score of 20 people is 1.6 or more as A, 1.0 or more but less than 1.6 is B, and less than 1.0 is C.

C2. Production of writing sheet for touch panel pen [Experimental example C1] Resin layer coating solution C1 with the following formulation was applied on a plastic film (triacetyl cellulose resin film with a thickness of 40 μm) so that the thickness after drying was 5 μm, dried, and then irradiated with ultraviolet rays to form a resin layer , and get a writing tablet for a touch panel pen.

<Resin layer coating solution C1> ・Neopentylthritol Triacrylate 81 parts (manufactured by Nippon Kayaku Co., Ltd., KAYARAD-PET-30) ・Organic Particles 13 parts (spherical polyacrylic acid-styrene copolymer, average particle size 3.5 μm) ・Fumed silica 6 servings (average primary particle size 10 nm) ・Photopolymerization initiators 3 parts (manufactured by BASF Corporation, Irgacure184) ・Silicone-based leveling agent 0.001 parts (manufactured by Momentive High-tech Materials Co., Ltd., TSF4460) ・Solvent 1 (toluene) 180 parts ・Solvent 2 (cyclohexanone) 70 parts ・Solvent 3 (methyl isobutyl ketone) 2 parts ・Solvent 4 28 parts (Propylene Glycol Monomethyl Ether Acetate)

[Experimental example C2] The resin layer coating solution C1 was changed to the resin layer coating solution C2 of the following formulation, and the thickness of the resin layer was changed to 7 μm. A writing sheet for a touch panel pen was obtained in the same manner as in Experimental Example C1. .

<Resin layer coating solution C2> ・Neopentylthritol Triacrylate 83 parts (manufactured by Nippon Kayaku Co., Ltd., KAYARAD-PET-30) ・Organic Particles 11 parts (spherical polystyrene, average particle size 3.5 μm) ・Fumed silica 7 servings (average primary particle size 10 nm) ・Photopolymerization initiator                                                                                                                     (manufactured by BASF Corporation, Irgacure184) ・Silicone-based leveling agent 0.125 parts (manufactured by Momentive High-tech Materials Co., Ltd., TSF4460) ・Solvent 1 (toluene) 225 parts ・Solvent 2 (cyclohexanone) 3 parts ・Solvent 3 (methyl isobutyl ketone) 50 parts ・Solvent 4 (isopropanol) 28 parts

[Experimental example C3] The resin layer coating liquid C1 was changed to the resin layer coating liquid C3 of the following formula, the thickness of the resin layer was changed to 6 μm, and the thickness of the second resin layer coating liquid C1 of the following formula after drying was 0.1 μm is coated on the resin layer, dried, and irradiated with ultraviolet rays to form a second resin layer, and a writing sheet for a touch panel pen is obtained.

<Resin layer coating solution C3> ・ 17.9 copies of triglycerite with pentaoliol (manufactured by Nippon Kayaku Co., Ltd., KAYARAD-PET-30) ・Urethane Acrylate (manufactured by Japan Synthetic Chemicals Co., UV1700B) 81.4 parts ・Fumed silica 0.5 parts (average primary particle size 10 nm) ・Photopolymerization initiators 3 parts (manufactured by BASF Corporation, Irgacure184) ・Silicone-based leveling agent 0.2 parts (manufactured by Momentive High-tech Materials Co., Ltd., TSF4460) ・Solvent 1 (methyl isobutyl ketone) 4 parts ・Solvent 2 (toluene) 160 parts ・Solvent 3 (cyclohexanone) 27 parts ・Solvent 4 (isopropanol) 63 parts

<Second resin layer coating liquid C1> ・Neopentylthritol Triacrylate                                           (manufactured by Nippon Kayaku Co., Ltd., KAYARAD-PET-30) ・Urethane Acrylate (manufactured by Nippon Synthetic Chemicals, UV1700B) 43 parts ・Hollow silica 5 parts (average primary particle size 50 nm) ・Photopolymerization initiators 3 parts (manufactured by BASF Corporation, Irgacure184) ・Fluorine-based leveling agent 1 part (Manufactured by DIC Corporation, MEGAFACE RS-75) ・Solvent 1 (methyl isobutyl ketone) 135 parts ・Solvent 2 (methyl ethyl ketone) 232 parts ・Solvent 3 176 parts (Propylene Glycol Monomethyl Ether Acetate)

[Experimental example C4] The resin layer coating solution C1 was changed to the resin layer coating solution C4 of the following formulation, and the thickness of the resin layer was changed to 3 μm. A writing sheet for a touch panel pen was obtained in the same manner as in Experimental Example C1. . <Resin layer coating solution C4> ・Neopentylthritol Triacrylate 93 parts (manufactured by Nippon Kayaku Co., Ltd., KAYARAD-PET-30) ・Inorganic microparticles 5 parts (Manufactured by Fuji Silesian Chemical Co., Ltd., gel method amorphous silica) (Hydrophobic treatment, average particle size (by laser diffraction scattering method) 4.1 μm) ・Photopolymerization initiator 5 parts (manufactured by BASF Corporation, Irgacure184) ・Silicone-based leveling agent 0.001 parts (TSF4460 manufactured by Momentive Advanced Materials) ・Solvent 1 (methyl isobutyl ketone) 30 parts ・Solvent 2 (methyl ethyl ketone) 30 parts ・Solvent 3 (isopropanol) 30 parts ・Solvent 4 (n-butanol) 30 parts

[table 5] table 5 Experimental example C1 Experimental example C2 Experimental example C3 Experimental example C4 Pen C1 µk 0.13 0.10 0.16 0.09 μs 0.31 0.33 0.29 0.12 μk/μs 0.42 0.30 0.55 0.75 writing sense A A B C Pen C2 µk 0.15 0.16 0.18 0.17 μs 0.37 0.37 0.44 0.38 μk/μs 0.41 0.43 0.41 0.45 writing sense A A A B Pen C3 µk 0.10 0.09 0.12 0.12 μs 0.16 0.19 0.28 0.18 μk/μs 0.63 0.48 0.43 0.67 writing sense C B A C Pen C4 µk 0.08 0.13 0.20 0.13 μs 0.42 0.31 0.47 0.31 μk/μs 0.19 0.42 0.43 0.42 writing sense C A A A Haze (%) 24.9 39.3 0.2 20.7 The sum of Cs through clarity (%) 154.1 196.6 289.2 24.2 Anti-glare A A C B

As shown in Table 5, the writing sheet whose μk/μs showed a value of not less than 0.30 and not more than 0.58 was evaluated as A or B for the writing feeling. This fact shows that selection of a writing sheet having a value of not less than 0.30 and not more than 0.58 in μk/μs is related to selection of a writing sheet having a good writing feeling. Also, the pens C1 to C4 are all different types, so the results in Table 5 show the following: when using any touch panel pen, select the writing sheet that shows a value of 0.30 or more and 0.58 or less in μk/μs It is related to the selection of writing sheets with good writing feeling. In addition, regarding the writing sheets for touch panel pens of Experimental Examples C1 and C2, it was confirmed that the writing feeling of the touch panel pens (pen C1 and pen C2) whose X value in the above formula (i) exceeds 500 MN/m is extremely good , and good anti-glare property. It is considered that the reason is that in the writing sheets for touch panel pens of Experimental Examples C1 and C2, since the resin layer contains micron-sized particles and nano-sized inorganic ultrafine particles, the unevenness of the small area and the unevenness of the larger area on the surface of the resin layer are mixed. formed by existence.

C3. Production of touch panel A conductive film of ITO with a thickness of 20 nm was formed on the surface of the substrate side of the writing sheets for touch panel pens of Experimental Examples C1 to C4 by sputtering to form an upper electrode plate. Next, a conductive film of ITO with a thickness of about 20 nm was formed on one side of a tempered glass plate with a thickness of 1 mm by sputtering to form a lower electrode plate. Next, ionizing radiation-curable resin (Dot Cure TR5903: Sun Ink Co., Ltd.) as a coating liquid for spacers is printed in dots on the surface of the conductive film with the lower electrode plate by screen printing, and then the A 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 faced each other, and the edges were bonded with a double-sided tape with a thickness of 30 μm and a width of 3 mm, and the resistive film type of Experimental Examples C1 to C4 were produced. touch panel. When using the above-mentioned touch panel pens C1-C4 to write on the resistive film touch panels of Experimental Examples C1-C4, the evaluation of the writing feeling of each touch panel pen is the same as in Table 5. As a result, it was shown that in a touch panel system composed of a combination of a touch panel and a touch panel pen, a touch panel system in which μk/μs shows a value of 0.30 or more and 0.58 or less has a good writing feeling. In addition, the resistive film touch panels of Experimental Examples C1-C4 were mounted on a commercially available ultra-high-definition liquid crystal display device (smartphone manufactured by Sharp, product name: SH-03G, pixel density 480 ppi), and placed on a fluorescent screen. Visually evaluate the images under light illumination. As a result, the touch panels of Experimental Examples C1-2 have better anti-glare performance than the touch panel of Experimental Example C3. Compared with the touch panel of Experimental Example C4, they can suppress ultra-high-definition display The resolution of the component is reduced.

C4. Manufacture of display device The writing sheets for touch panel pens of Experimental Examples C1-C4 were bonded to a commercially available ultra-high-definition liquid crystal display device (smartphone manufactured by Sharp, product name: SH-03G, pixel density 480 ppi) via a transparent adhesive , and the display devices of Experimental Examples C1-C4 were fabricated. In addition, when bonding, the surface of the writing sheet base material side for touch panel pens faces the display element side. The above-mentioned touch panel pens C1-C4 were used to write on the display devices of Experimental Examples C1-C4, and the evaluation of the writing feeling of each touch panel pen was the same as in Table 5. In addition, the images of the display devices of Experimental Examples C1 to C4 were visually evaluated under fluorescent lighting. As a result, the display devices of Experimental Examples C1 to C2 were superior in anti-glare performance than the display device of Experimental Example C3, which was comparable to that of Experimental Example C4. Compared with the display device, it can suppress the reduction of the resolution of the ultra-high-definition display element. [Industrial availability]

The writing sheet for a touch panel pen, touch panel, touch panel system, and display device of the present invention are useful in improving the writing feeling of a touch panel pen. In addition, the method for selecting writing sheets for touch panel pens of the present invention is useful in terms of efficient product design and quality control of writing sheets.

1: plastic film 2: resin layer 10: Writing tablet for touch panel pen 20: Transparent substrate 30: Conductive film 40: spacer 50: X-axis electrode 60: Y-axis electrode 70: Insulator layer 82: Movable table 83: Weight 84: retainer 85: base 100: Touch panel 200: touch panel pen 300: fixture 400: stainless steel plate

[ Fig. 1 ] is a cross-sectional view showing an embodiment of the writing sheet for a touch panel pen of the present invention. [ Fig. 2 ] is a cross-sectional view showing another embodiment of the writing sheet for a touch panel pen of the present invention. [ Fig. 3 ] is a cross-sectional view showing an embodiment of the touch panel of the present invention. [ Fig. 4 ] is a cross-sectional view showing another embodiment of the touch panel of the present invention. [FIG. 5] A schematic diagram of a method of measuring the apparent Young's modulus E of the structure of the nib and the shaft. [FIG. 6] It is a figure explaining the calculation method of the diameter D of a touch panel pen. [Fig. 7] is a schematic diagram explaining the method of measuring the coefficient of friction.

1: plastic film

2: resin layer

10: Writing tablet for touch panel pen

Claims (5)

A method for selecting a writing sheet for a touch panel pen, selecting the surface that satisfies the following conditions (C1) and (C2) and satisfies the following conditions (C1) and (C2) as containing particles with an average particle size of 0.2 to 8.0 μm And the resin layer of inorganic ultrafine particles with an average primary particle size of 1~25nm is used as a writing sheet for a touch panel pen. <Condition (C1)> put the touch panel pen at an angle of 60 degrees to touch the touch panel pen for writing The surface of the sheet is fixed, and while applying a vertical load of 100gf to the touch panel pen, it scans a length of 40mm in a single pass at a speed of 14mm/sec. The dynamic friction coefficient acting on the scanning direction of the touch panel pen at this time is set to For μk, when the coefficient of static friction is μs, μk/μs is not less than 0.30 and not more than 0.44, and <condition (C2)>0.08≦μk≦0.20. A writing sheet for a touch panel pen, having a surface that satisfies the following conditions (C1) and (C2), and the surface that satisfies the following conditions (C1) and (C2) contains particles with an average particle diameter of 0.2 to 8.0 μm and The resin layer of inorganic ultrafine particles with an average primary particle size of 1~25nm, <Condition (C1)> Fix the touch panel pen in the state of contacting the surface of the writing sheet for the touch panel pen at an angle of 60 degrees, one side facing The touch panel pen applies a vertical load of 100gf and scans a length of 40mm in a single pass at a speed of 14mm/sec. When the kinetic friction coefficient acting on the touch panel pen in the scanning direction at this time is set as μk, and the static friction coefficient is set as μs, μk/μs is not less than 0.30 and not more than 0.44, and <condition (C2)>0.08≦μk≦0.20. A touch panel having a sheet on the surface, wherein the surface of the writing sheet for a touch panel pen as claim 2 of the sheet that satisfies the condition is arranged to face the surface of the touch panel. A touch panel system is composed of a touch panel with a writing sheet for a touch panel pen on the surface and a touch panel pen. The touch panel system satisfies the following conditions (C1) and (C2), and satisfies the following conditions (C1 ) and (C2) are resin layers containing particles with an average particle size of 0.2-8.0 μm and inorganic ultrafine particles with an average primary particle size of 1-25 nm. <Condition (C1)> use the touch panel pen at 60 The angle of degree is fixed in the state of touching the surface of the writing sheet for the touch panel pen. While applying a vertical load of 100gf to the touch panel pen, scan the length of 40mm in one way at a speed of 14mm/second, and apply this time to the touch panel pen. When the kinetic friction coefficient in the scanning direction of the control panel pen is set to μk, and the static friction coefficient is set to μs, μk/μs is not less than 0.30 and not more than 0.44, and <condition (C2)>0.08≦μk≦0.20. A display device has a touch panel, and the touch panel is the touch panel of claim 3.

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