JP6792743B1 - Surface material for pen input devices - Google Patents

Abstract

The surface material for a pen input device is a sheet-shaped surface material for a pen input device having an input surface input by a pen, and has a transmission image sharpness of 30% or more and 100% or less with an optical comb width of 0.5 mm. The input surface is set to a value in the range, the arithmetic mean roughness Ra is set to a value in the range of more than 0 and less than 0.5 μm, and the rolling circle maximum waviness WEM is in the range of 5.0 μm or more. It is set to a value.

Description

The present invention relates to a surface material for a pen input device.

The pen input device input by the stylus pen (contactor) has a surface material for the pen input device (hereinafter, simply referred to as simply) on the surface of the display in order to realize a writing taste such as when writing with a pen on paper. (Also referred to as a surface material) may be arranged.

The input surface of the surface material is required to have an appropriate input resistance with respect to the stylus pen. Therefore, for example, as disclosed in Patent Document 1, a surface material in which irregularities are formed on the input surface by dispersing particles having a certain particle size in the coating material of the surface material is known.

Japanese Unexamined Patent Publication No. 2014-232277

By the way, when a surface material is attached to the surface of a display or the like having high-definition pixels, the emitted light of the display that has passed through the surface material may be scattered by the unevenness of the input surface, and the image visibility may be deteriorated. As a result, for example, the outline of the character displayed on the display becomes blurred, and it may be difficult to distinguish the character. As a countermeasure for this problem, for example, a method of reducing the unevenness of the input surface can be considered, but the writing quality of the surface material may be deteriorated.

Therefore, an object of the present invention is to prevent deterioration of image visibility and to obtain excellent writing quality in a surface material for a pen input device.

In order to solve the above problems, the surface material for a pen input device according to one aspect of the present invention is a sheet-shaped surface material for a pen input device having an input surface input by a pen, and has an optical comb width of 0.5 mm. The transmission image sharpness of is set to a value in the range of 30% or more and 100% or less, and the input surface is set to a value in which the arithmetic mean roughness Ra is greater than 0 and less than 0.5 μm. rolling circle maximum swell _{W EM} is set to a value in the range of more than 5.0μm.

According to the above arrangement, the arithmetic mean roughness Ra and the rolling circle maximum waviness W _EM of the input surface of the surface material for a pen input device, it is set to the value of the above range, the appropriate size on the input face Waviness and fine irregularities are formed. For this reason, when inputting to the input surface with a pen, the vibration and acceleration of the pen when the pen is caught and separated from the input surface become close to the vibration and acceleration of the pen when writing with the pen on paper, respectively. An excellent writing taste close to that of is obtained.

Further, by setting the transmission image sharpness of the surface material for the pen input device with an optical comb width of 0.5 mm to a value in the range of 30% or more and 100% or less, the display passing through the surface material for the pen input device is set. The emitted light can travel straight through the surface material. As a result, it is possible to prevent the image visibility of the display from being lowered.

Further, by setting the arithmetic average roughness Ra of the input surface to a value in the above range, it is possible to impart antiglare property to the input surface and scatter external light incident on the input surface. As a result, it is possible to prevent the image visibility of the display from being lowered due to the reflection of external light.

A sheet-shaped base member and a coating member covering one surface of the base member are provided, and the coating member includes a coating material extending along the one surface of the base member and the coating material in the coating material, respectively. It has dispersed first particles and second particles, the average particle size of the first particles is set to a value in the range of 8 μm or more and 15 μm or less, and the average particle size of the second particles is 0.4 μm. It may be set to a value in the range of not more than 0.7 μm.

According to the above configuration, since the first particles can form a relatively large convex portion on the input surface of the coat member, the writing quality of the surface material can be improved by making it easier for the pen to be caught on the input surface. Further, since the second particle can form a relatively small convex portion on the input surface of the coated member, it is possible to easily scatter the external light incident on the input surface of the coated member. Further, by using the first particle and the second particle whose average particle size is set as described above, the aesthetic appearance of the coating member can be maintained by making the first particle inconspicuous by the second particle.

Further, the first particles may be acrylic particles and the second particles may be silica particles. As a result, the coated member can be easily manufactured, and the first particles and the second particles having appropriate optical characteristics and hardness can be easily formed.

The surface of the coat member opposite to the base member may be the input surface. As a result, the surface shape of the input surface can be easily adjusted by appropriately setting the configuration of the coated member while maintaining the configuration of the base member.

Further, the refractive index difference between the coating material and the first particles and the refractive index difference between the coating material and the second particles may be set to a value in the range of 0 or more and 0.07 or less. .. As a result, the emission light of the display is prevented from being refracted at the boundary between the coating material and the first particle and the boundary between the coating material and the second particle, and the straightness of the emission light of the display passing through the surface material is straightforward. Can be improved.

The total weight of the first particles added to the coating member may be less than the total weight of the second particles added to the coating member. As a result, by arranging the first particles more sparsely than the second particles in the coating member while preventing deterioration of the image visibility of the display, a better writing taste of the surface material can be obtained.

The haze of the coated member may be set to a value in the range of 8% or more and 39% or less. As a result, it is possible to maintain appropriate transparency of the coated member, prevent deterioration of the image visibility of the display, and impart good antiglare property to the input surface.

According to each aspect of the present invention, in the surface material for a pen input device, deterioration of image visibility can be prevented and excellent writing quality can be obtained.

It is a schematic cross-sectional view of the pen input device which concerns on embodiment.

(Embodiment)
Hereinafter, embodiments will be described with reference to each figure.
[Surface material for pen input devices]

FIG. 1 is a schematic cross-sectional view of the pen input device 10 according to the embodiment. As shown in FIG. 1, the pen input device 10 includes a device unit 7 and a pen input surface material 1 (hereinafter, simply referred to as a surface material 1). The device unit 7 has a display 8. The device unit 7 is, for example, a tablet PC, but is not limited to this, and may be a mobile information terminal such as a smartphone.

The surface material 1 is formed in the form of a sheet having an input surface 3a input by a pen. The surface material 1 of the present embodiment includes a sheet-shaped base member 2 and a coat member 3 that covers one surface of the base member 2. The surface material 1 has light transmittance, and the total light transmittance Tt (total transparency) is set to a value in the range of 85% or more and 100% or less as an example. Further, in the surface material 1, the transmission image clarity IC (image clarity) having an optical comb width of 0.5 mm is set to a value in the range of 30% or more and 100% or less. The surface material 1 is a film member here, but the thickness dimension is not limited. Therefore, the surface material 1 may be, for example, a plate member.

The base member 2 is a transparent member, supports the coat member 3 on one surface, and is mounted on the display surface 8a of the display 8 on the other surface side. The material of the base member 2 is, for example, polyethylene terephthalate (PET), but the material is not limited thereto. The base member 2 is a film member here, but its thickness is not limited. Therefore, the base member 2 may be, for example, a plate member. When the base member 2 is a film member, the thickness dimension of the base member 2 is, for example, a value in the range of several tens of μm or more and several hundred μm or less (here, a value in the range of 100 μm or more and 150 μm or less, 125 μm as an example). Set.

The coat member 3 is a transparent member and is arranged so as to cover one surface of the base member 2 (upper surface 2a located on the side opposite to the display surface 8a). The coat member 3 has an input surface 3a arranged on the side opposite to the base member 2 side. The input surface 3a is a surface that comes into contact with the pen for the pen input device. The material of the tip portion of the pen can be appropriately set, and as an example, polyacetal (POM) is used. The thickness dimension of the coat member 3 is not limited.

Input surface 3a of the surface material 1, with the arithmetic average roughness Ra is set to a value in the range of less than greater than 0 0.5 [mu] m, the rolling circle maximum waviness W _EM is set to a value in the range of more than 5.0μm ing. Although the upper limit of the rolling circle maximum waviness W _EM can be appropriately set, for example, it can be less than or equal to 15.0 .mu.m. Further, the haze Hz of the coat member 3 (here, the external haze of the input surface 3a) is set to a value in the range of 8% or more and 39% or less.

The coating member 3 of the present embodiment has a coating material 4 extending along the upper surface 2a of the base member 2, and first particles 5 and second particles 6 dispersed in the coating material 4, respectively. The coating material 4, the first particle 5, and the second particle 6 all have light transmittance. As each material of the base member 2 and the coating material 4, for example, the material described in Japanese Patent No. 6258249 can be used.

The coating material 4 contains a binder component for fixing the first particles 5 and the second particles 6. As an example of this binder component, the coating material 4 contains a resin material (for example, a polyfunctional (meth) acrylate having excellent strength such as scratch resistance). Further, as an example, the first particle 5 is an acrylic particle, and the second particle 6 is a silica particle (nanosilica particle).

It is preferable that the difference in the refractive index between the coating material 4 and the first particle 5 and the difference in the refractive index between the coating material 4 and the second particle 6 are small. In the present embodiment, the refractive index difference between the coating material 4 and the first particle 5 and the refractive index difference between the coating material 4 and the second particle 6 are set to values in the range of 0 or more and 0.07 or less. There is.

Further, in order to maintain a good writing quality of the surface material 1, it is desirable that the first particle 5 and the second particle 6 have appropriate hardness. For example, the first particles 5 second particles 6, the intensity of when compressed 10 percent using a micro-compression tester (S10 intensity), of 0.1 kgf / mm ² or more 10.0 kgf / mm ² or less in the range It is desirable that it is set to a value.

The first particles 5 as the value of the intensity of the second particles 6, and more preferably a value of more 0.5 kgf / mm ² or more 8.0 kgf / mm ² or less in the range, 1.0 kgf / mm ² or more 5 .0kgf / mm ² or less and still more preferably a value in the range of (especially 1.5 kgf / mm ² or more 3.0 kgf / mm ² or less).

The average particle size of the first particle 5 is set to a value in the range of 8 μm or more and 15 μm or less. The average particle size of the second particle 6 is set to a value in the range of 0.4 μm or more and less than 0.7 μm. In the surface material 1, as an example, the total added weight of the first particles 5 of the coating member 3 is smaller than the total added weight of the second particles 6 of the coating member 3.

The particles 5 and 6 are held by the coating material 4 in a state of being dispersed inside the coating material 4 and covered with the coating material 4. The coating material 4 partially protrudes to the side opposite to the base member 2 side at a position corresponding to the particles 5 and 6 in the thickness direction while covering the particles 5 and 6.

Specifically, the coating material 4 has protrusions 3b and 3c. The protruding portion 3b projects from the peripheral region of the position corresponding to the thickness direction of the first particle 5 and the coating material 4 to the side opposite to the base member 2. The protruding portion 3c protrudes from the peripheral region of the position corresponding to the thickness direction of the second particle 6 and the coating material 4 to the side opposite to the base member 2. The amount of protrusion of the protruding portion 3b is larger than the amount of protrusion of the protruding portion 3c. Further, in a plan view, the outer diameter of the protruding portion 3b is larger than the outer diameter of the protruding portion 3c.

In the surface material 1, a plurality of protruding portions 3b and 3c are dispersedly arranged along the input surface 3a of the coating member 3. In other words, on the input surface 3a of the coat member 3, at least one protrusion 3c is arranged between a pair of protrusions 3b adjacent to each other along the surface of the base member 2.

Here, the total light transmittance can be measured by a method conforming to JIS K7136. Haze Hz can be measured by a method conforming to JIS K7136. The total light transmittance and the haze Hz can be measured by the measuring device described in JIS K7136.

The transmitted image sharpness IC can be measured by a method conforming to JIS K7105. The transmission image sharpness IC can be measured by the mapping measuring device described in JIS K7105. The arithmetic mean roughness Ra and the rolling circle maximum waviness _{W EM} can be measured by a method conforming to JIS B 0601.

The arithmetic mean roughness Ra can be measured by, for example, a surface roughness shape measuring machine or a scanning white interference microscope. Rolling circle maximum waviness W _EM is, for example, it can be measured by a surface roughness shape measuring machine. The average particle size of the first particle 5 and the second particle 6 can be measured by using a light-shielding type submerged particle counter based on a method based on JIS B9916.

As described above, the surface material 1 is a sheet-shaped surface material for a pen input device having an input surface 3a input by a pen, and has a transmission image sharpness of 30% or more with an optical comb width of 0.5 mm. is set to a value in the range of 100% or less, the input surface 3a, together with the arithmetic average roughness Ra is set to a value in the range of less than greater 0.5μm than 0, the rolling circle maximum waviness _{W EM} is more 5.0μm It is set to a value in the range of.

According to the above arrangement, the arithmetic mean roughness Ra and the rolling circle maximum waviness W _EM input surface 3a of the coating member 3, it is set to the value of the above range, undulation of appropriate size on the input surface 3a And fine irregularities are formed. Therefore, when inputting to the input surface 3a with the pen, the vibration and acceleration of the pen when the pen is caught and separated from the input surface 3a are close to the vibration and acceleration of the pen when writing with the pen on paper, respectively. , An excellent writing taste close to that of paper can be obtained.

Further, by setting the transmission image sharpness of the surface material 1 having an optical comb width of 0.5 mm to a value in the range of 30% or more and 100% or less, the emitted light of the display 8 passing through the surface material 1 is the surface material. You can go straight in 1 well. As a result, it is possible to prevent the image visibility of the display 8 from being lowered. Therefore, for example, even when a character is displayed on the display 8, the outline of the character can be clearly displayed through the surface material 1, and the character can be appropriately discriminated.

Further, by setting the arithmetic average roughness Ra of the input surface 3a to a value in the above range, the input surface 3a can be provided with antiglare property and the external light incident on the input surface 3a can be scattered. As a result, it is possible to prevent the image visibility of the display 8 from being lowered due to the reflection of external light.

Further, the surface material 1 of the present embodiment includes a sheet-shaped base member 2 and a coat member 3 that covers one surface of the base member 2, and the surface of the coat member 3 on the side opposite to the base member 2 is provided. , Input surface 3a. Thereby, the surface shape of the input surface 3a can be easily adjusted by appropriately setting the configuration of the coating member 3 while maintaining the configuration of the base member 2.

Further, in the present embodiment, the coating member 3 has a coating material 4 extending along one surface of the base member 2, and first particles 5 and second particles 6 dispersed in the coating material 4, respectively. The average particle size of the first particle 5 is set to a value in the range of 8 μm or more and 15 μm or less, and the average particle size of the second particle 6 is set to a value in the range of 0.4 μm or more and less than 0.7 μm.

As a result, the first particle 5 can form a relatively large convex portion on the input surface 3a of the coating member 3, so that the writing quality of the surface material 1 can be improved by making it easier for the pen to be caught on the input surface 3a. Further, since the second particle 6 can form a relatively small convex portion on the input surface 3a of the coat member 3, it is possible to easily scatter the external light incident on the input surface 3a of the coat member 3. Further, by using the first particle 5 and the second particle 6 whose average particle size is set as described above, the second particle 6 makes the first particle 5 inconspicuous and maintains the aesthetic appearance of the coat member 3. it can.

Further, since the first particle 5 is an acrylic particle and the second particle 6 is a silica particle, the coating member 3 can be easily manufactured, and the first particle 5 and the second particle 6 having appropriate optical characteristics and hardness can be easily manufactured. Can be easily configured.

Further, the difference in refractive index between the coating material 4 and the first particle 5 and the difference in refractive index between the coating material 4 and the second particle 6 are set to values in the range of 0 or more and 0.07 or less. At the boundary between the coating material 4 and the first particle 5 and the boundary between the coating material 4 and the second particle 6, the emitted light of the display 8 is prevented from being refracted, and the display 8 passes through the surface material 1. The straightness of the light can be improved.

Further, in the present embodiment, the total added weight of the first particles 5 of the coating member 3 is smaller than the total added weight of the second particles 6 of the coating member 3. As a result, by arranging the first particles 5 more sparsely than the second particles 6 in the coating member 3 while preventing the deterioration of the image visibility of the display 8, a better writing taste of the surface material 1 can be obtained. ..

Further, in the present embodiment, the haze of the coat member 3 is set to a value in the range of 8% or more and 39% or less. As a result, it is possible to maintain appropriate transparency of the coat member 3, prevent deterioration of the image visibility of the display 8, and impart good antiglare property to the input surface 3a.

Here, conventionally, it has been found by the present inventors that the problem that the image visibility of the display 8 is lowered by attaching the surface material becomes relatively remarkable when the resolution of the display 8 is 200 ppi or more. One of the reasons for this is that, for example, when the emitted light of the display 8 is incident on the surface material, the emitted light of the display 8 is refracted by a large number of relatively large convex portions formed on the input surface of the surface material. Conceivable.

Therefore, for example, when the pixels of a specific color of the display 8 are arranged at positions shifted from the position directly below the top of the convex portion of the input surface, the pixels of this color have a size different from that of the pixels of other colors. May be visible.

On the other hand, in the surface material 1 of the present embodiment, since the input surface 3a is formed with fine irregularities by the second particles 6, such refraction is unlikely to occur. Therefore, when the surface material 1 is applied to the device unit 7 including the display 8 having high-definition pixels, the high-definition image visibility of the display 8 can be well maintained while improving the writing quality of the input surface 3a.

If the transmitted image sharpness of the surface material 1 having an optical comb width of 0.5 mm is less than 30%, the image display performance of the display 8 via the surface material 1 may be deteriorated. Further, if the arithmetic average roughness Ra of the input surface 3a is 0.5 μm or more, the light emitted from the display 8 may be scattered. Further, the rolling circle maximum waviness W _EM of the input surface 3a is less than 5.0 .mu.m, writing feeling of the input surface 3a may be reduced.

Further, if the average particle size of the first particles 5 is less than 8 μm, the writing quality of the input surface 3a may deteriorate. Further, if the average particle size of the first particles 5 exceeds 15 μm, the scratch resistance may decrease. Further, when the average particle size of the second particles 6 is less than 0.4 μm, the effect of suppressing the scattering of the emitted light from the display 8 and the effect of antiglare against the incident light on the input surface 3a are reduced. There is a risk. Further, if the average particle size of the second particle 6 is 0.7 μm or more, the wear of the pen may increase.

Further, if the haze of the coat member 3 is less than 8%, the antiglare effect of the surface material 1 may be reduced. Further, if the haze of the coat member 3 exceeds 39%, the image visibility of the display 8 may be lowered (character blurring or the like may occur).

Further, when the difference in the refractive index between the coating material 4 and the first particle 5 or the difference in the refractive index between the coating material 4 and the second particle 6 exceeds 0.07, the emitted light of the display 8 is inside the coating member 3. There is a risk that it will be difficult to see through.

Note that in the surface material 1, since the rolling circle maximum waviness W _EM is set to a value in the range of more than 5.0 .mu.m, the influence of the second particles 6 in coating member 3 scatters the light emitted display 8 is relatively small.

Hereinafter, a modified example of the embodiment will be described focusing on the difference from the embodiment. The surface material according to this modification is composed of a single sheet member. On the surface of the surface material, a large protrusion corresponding to the protrusion 3b and a small protrusion 11b corresponding to the protrusion 3c are formed. As a result, the surface material has the same surface shape as the surface material 1 and has the same transmission image sharpness as the surface material 1. The surface shape of the surface material is formed by, for example, a sandblasting method or a transfer method. Even with such a surface material, the same effect as that of the surface material 1 can be obtained.

The surface material may be composed of a sheet-shaped base resin and the first particles 5 and the second particles 6 dispersed in the base resin, respectively. As a method for producing such a surface material, first, a adjusting liquid is prepared by adding the first particles 5 and the second particles 6 to the resin solution that is the source of the base resin. A surface material can be obtained by casting this adjusting liquid on the surface of a support member having a smooth surface, curing the adjusting liquid, and peeling the adjusting liquid from the support member.

(Confirmation test)
Next, the confirmation test will be described, but the present invention is not limited to the examples shown below.

Surface materials for each pen input device of Examples 1 to 4 and Comparative Examples 1 to 6 having coating members having the compositions shown in Tables 1 and 2 below were prepared. Examples 1 to 4 correspond to the surface material 1 according to the embodiment in which the coating member 3 has the first particles 5 (acrylic particles) and the second particles 6 (nanosilica particles).

In Comparative Examples 1 and 2, the coating member has first particles and second particles having a larger average particle size than those of Examples 1 to 4. In Comparative Example 3, the coating member does not have the first particle and has only the second particle. In Comparative Examples 4 and 5, unevenness is formed on the input surface of the coated member due to the phase separation structure. In Comparative Example 6, the coating member does not have the second particle and has only the first particle.

The phase separation structure is formed by spinodal decomposition (wet spinodal decomposition) from the liquid phase of the adjusting liquid that is the source of the coating member. For details of the phase-separated structure referred to here, for example, Japanese Patent No. 6190581 can be referred to.

The adjusting liquids used as the basis of the coating members of Examples 1 to 4 and Comparative Examples 1 to 6 were adjusted as follows.

The adjusting liquid of Example 1 was prepared by 48 parts by weight of Tokushiki Co., Ltd. "AU-230" (containing particles corresponding to the second particles and a polymerization initiator), 10 parts by weight of Tokushiki Co., Ltd. "AS-201S", Sekisui Plastics Co., Ltd. "SSX-115HXE" (particles corresponding to the first particle) was obtained by mixing 0.3 parts by weight and 42 parts by weight of methyl ethyl ketone.

The adjusting solution of Example 2 was 29 parts by weight of Tokushiki Co., Ltd. "AU-230" (containing particles corresponding to the second particles and a polymerization initiator), 21 parts by weight of Tokushiki Co., Ltd. "AS-201S", Sekisui Plastics Co., Ltd. "SSX-110" (particles corresponding to the first particle) was obtained by mixing 0.6 parts by weight and 50 parts by weight of methyl ethyl ketone.

The adjusting liquid of Example 3 was 29 parts by weight of Tokushiki Co., Ltd. "AU-230" (containing particles corresponding to the second particles and a polymerization initiator), 21 parts by weight of Tokushiki Co., Ltd. "AS-201S", Sekisui Plastics Co., Ltd. "SSX-108" (particles corresponding to the first particle) was obtained by mixing 0.6 parts by weight and 50 parts by weight of methyl ethyl ketone.

The adjusting liquid of Example 4 was prepared by 43 parts by weight of Tokushiki Co., Ltd. "AU-230" (containing particles corresponding to the second particles and a polymerization initiator), 10 parts by weight of Tokushiki Co., Ltd. "AS-201S", Sekisui Plastics Co., Ltd. "SSX-115HXE" (particles corresponding to the first particle) was obtained by mixing 0.7 parts by weight and 42 parts by weight of methyl ethyl ketone.

The adjusting solution of Comparative Example 1 was 80 parts by weight of Daicel Ornex Co., Ltd. "DPHA", 20 parts by weight of Miwon "PU3210", 7 parts by weight of Eastman "Cellulose Acetate Propionate", and "SSX-" of Sekisui Kasei Kogyo Co., Ltd. 4 parts by weight of "108" (particles corresponding to the second particle), 2 parts by weight of "SSX-115HXE" (particles corresponding to the first particle), and 2 parts by weight of "Irgacure 184" were mixed, and methyl ethyl ketone / 1-butanol / It was obtained by adjusting the solid content concentration to 31% with a 1-methoxy-2-propanol mixed solvent.

The adjusting solution of Comparative Example 2 was 80 parts by weight of Daicel Ornex Co., Ltd. "DPHA", 20 parts by weight of Miwon "PU3210", 7 parts by weight of Eastman "Cellulose Acetate Propionate", and Sekisui Kasei Kogyo Co., Ltd. "SSX-". 10 parts by weight of "110" (particles corresponding to the second particle), 4 parts by weight of "SSX-115HXE" (particles corresponding to the first particle), and 2 parts by weight of "Irgacure 184" were mixed, and methyl ethyl ketone / 1-butanol / It was obtained by adjusting the solid content concentration to 31% with a 1-methoxy-2-propanol mixed solvent.

The adjusting liquid of Comparative Example 3 was 63 parts by weight of Nippon Kako Paint Co., Ltd. "FA-3201 Clear" and Nippon Kako Paint Co., Ltd. "FA-3201M" (particles corresponding to the second particles and a polymerization initiator. It is contained.) It was obtained by mixing 37 parts by weight.

The adjusting solution of Comparative Example 4 was 5.7 parts by weight of "Cyclomer P" manufactured by Daicel Ornex Co., Ltd., 1.2 parts by weight of cellulose acetate propionate, 4 parts by weight of dipentaerythritol hexaacrylate, and silicone acrylate 2. It was obtained by dissolving 77 parts by weight and 0.5 part by weight of "Irgacure 184" in a mixed solvent of 25 parts by weight of methyl ethyl ketone and 12.2 parts by weight of 1-butanol.

The adjusting solution of Comparative Example 5 was 12.5 parts by weight of "Cyclomer P" manufactured by Daicel Ornex Co., Ltd., 4 parts by weight of cellulose acetate propionate, 150 parts by weight of nanosilica-containing acrylic UV curable compound A, and silicone acrylate. 1 part by weight of "Irgacure 184" and 1 part by weight of "Irgacure 907" are dissolved in a mixed solvent of 81 parts by weight of methyl ethyl ketone, 24 parts by weight of 1-butanol and 13 parts by weight of 1-methoxy-2-propanol. Obtained by

The adjusting solution of Comparative Example 6 was 80 parts by weight of Daicel Ornex Co., Ltd. "DPHA", 20 parts by weight of Miwon "PU3210", 7 parts by weight of Eastman "Cellulose Acetate Propionate", and Sekisui Kasei Kogyo Co., Ltd. "SSX-". Mix 5 parts of "120" (particles corresponding to the first particle) and 2 parts by weight of "Irgacure 184", and adjust the solid content concentration to 31% with a mixed solvent of methyl ethyl ketone / 1-butanol / 1-methoxy-2-propanol. Obtained by adjusting.

In Examples 1 to 4 and Comparative Examples 1 to 6, the adjusting liquid obtained as described above was spilled onto the surface of the base member using wire bars # 12 to # 36 according to the desired film thickness, and then 80. An intermediate having a desired thickness dimension was obtained by heat treatment in an oven heated to a temperature in the range of ° C. or higher and 100 ° C. or lower. This intermediate was passed through an ultraviolet irradiation device (high-pressure mercury lamp manufactured by Ushio Electric Co., Ltd., ultraviolet irradiation amount of 500 mJ / cm ³ ) to perform ultraviolet curing treatment. As a result, a coat member was formed.

The "blending amount (wt%)" in Tables 1 and 2 indicates the weight ratio to the coated member after completion. The "average thickness (μm) of the coated member" is obtained by measuring the film thickness at any 10 points other than the region where the first particles of the surface material are arranged using an optical film thickness meter, and using the average as the average. The calculated value is shown.

Next, the following items were examined for the surface materials of Examples 1 to 4 and Comparative Examples 1 to 6.

[Haze and total light transmittance]
The total light transmittance of the surface material was measured using a haze meter (NDH-5000W, manufactured by Nippon Denshoku Co., Ltd.) in accordance with JIS K7136. The haze of the coated member was measured by arranging it so that the input surface was on the receiver side.

[Transparent image sharpness]
The transmission image sharpness of the surface material is based on JIS K7105 using a mapping measuring instrument (ICM-1T manufactured by Suga Test Instruments Co., Ltd.), and the direction of film formation of the base member and the direction of the comb teeth of the optical comb. The surface materials were arranged so that they were parallel to each other for measurement. The optical comb width was 0.5 mm.

[Arithmetic mean roughness Ra and rolling circle maximum swell _WEM ]
The arithmetic average roughness Ra of the input surface was measured using a surface roughness shape measuring machine "Surfcom 570A" manufactured by Tokyo Seimitsu Co., Ltd. in accordance with JIS B0601. Circle maximum waviness _{W EM} rolling input surface conforms to JIS B0610, were measured under the following conditions using the above measuring instrument.

Stylus: Swell stylus (0102505)
Speculator specifications: 800 μmR, ruby drive speed: 3 mm / s
λf reduction cutoff value: 8 mm
Measurement length: 15 mm

[Pen tip wear resistance]
Using a touch panel sliding tester, it was slid 10,000 times over a distance of 50 mm on the input surface with a 200 g load, Wacom Co., Ltd. Propen (KP-503E) (POM stylus pen with a tip diameter of 2 mm). The wear length of the pen tip was measured.

[Writing taste]
The writing quality of the input surface was evaluated for three items: writing ability, writing sound, and vibration. In this evaluation, eight testers used a Wacom Co., Ltd. Propen (KP-503E) (POM stylus pen with a tip diameter of 2 mm).

In the evaluation of writeability, "A" was given when 5 or more of the 8 examiners evaluated it as good, and "B" was given when 4 or less evaluated it as good. When evaluating the writing sound, "A" is given when it is evaluated that the sound is like writing with a pencil on the paper when inputting to the input surface with the above pen, and "A" is given when it is evaluated that there is no sound or almost no sound is heard. B ".

In the evaluation of vibration, the acceleration detector "NP-3211" manufactured by Ono Sokki Co., Ltd. was attached to the above pen, and the data of the acceleration change when a straight line with a length of 100 mm was written on the input surface was collected and frequency analysis was performed. The vibration value calculated by the following formula 1 was measured by the peak acceleration in the low frequency region in the range of 0 Hz or more and 5 Hz or less.

[Equation 1]
Vibration (dB) = 20 x log ₁₀ (α / 1 x ^10-5 )
However, α is Ben's acceleration (m / s ² ).
The results of these tests are shown in Tables 1 and 2.

As shown in Tables 1 and 2, Examples 1 to 4 have better transmission image sharpness IC than Comparative Examples 1 to 6, and are in any of the items of writability, writing sound, and vibration. Was also confirmed to have an excellent writing taste. Further, it was confirmed that in Examples 1 to 4, the wear resistance of the pen was significantly suppressed as compared with Comparative Examples 1 to 2 and 6.

In Comparative Examples 1 and 2, the transmission image sharpness of the surface material having an optical comb width of 0.5 mm was less than 30% (here, 2% or less), and the arithmetic mean roughness Ra of the input surface was 0.5 μm or more (here). Then it was 1 μm or more). In Comparative Examples 1 and 2, the coating member contained the first particle and the second particle, but as compared with Examples 1 to 4, the amount of the first particle blended was relatively large, so that the transmission image sharpness was improved. It is probable that a decrease and an increase in the arithmetic mean roughness Ra of the input surface occurred. When the transmission image sharpness is low, the image visibility of the display is lowered.

The Comparative Example 3, the rolling circle maximum waviness _{W EM} of the input surface is less than 5.0 .mu.m (where 3.8μm is). In Comparative Example 3, since the coating member did not contain the first particles, the writing quality (writing sound and vibration) was inferior to that of Examples 1 to 4. Further, in Comparative Example 6, the transmission image sharpness of the surface material having an optical comb width of 0.5 mm was less than 30% (15% in this case), and the arithmetic average roughness Ra of the input surface was 0.5 μm or more (1 in this case). .29 μm). In Comparative Example 6, since the coating member did not contain the second particles, it is considered that the transmitted image sharpness was lower than that in Examples 1 to 4. Further, it is considered that the image visibility of the display of Comparative Example 6 is lower than that of Examples 1 to 4.

The Comparative Example 4, the rolling circle maximum waviness _{W EM} of the input surface is less than 5.0 .mu.m (4.5 [mu] m in this case). In Comparative Example 5, the transmission image sharpness of the surface material having an optical comb width of 0.5 mm was less than 30% (here, 6% or less).

Further, in Comparative Examples 4 and 5, irregularities were formed on the input surface due to the phase separation structure, but it was found that the writing quality was inferior to that of Examples 1 to 4. From the above test results, the superiority of Examples 1 to 4 over Comparative Examples 1 to 6 was confirmed.

Further, according to another study conducted by the inventors, the transmission image sharpness of the surface material of Examples 1 to 4 having an optical comb width of 0.5 mm, the arithmetic mean roughness Ra of the input surface, and the maximum rolling circle waviness _WEM. Apart from the values _of, and set the transmission image clarity of the optical comb width 0.5mm to a value in the range of 30% to 100%, the arithmetic average roughness Ra of the input surface of and less than 0.5μm from 0 range of the circular maximum waviness W _EM rolling and sets the value, if set to a value in the range of more than 5.0 .mu.m, it was found that substantially the same effects as in examples 1 to 4 can be obtained.

The present invention is not limited to the above embodiment, and its configuration can be changed, added, or deleted without departing from the spirit of the present invention.

1 Surface material for pen input device 2 Base member 3 Coat member 3a Input surface 4 Coat material 5 First particle 6 Second particle 10 Pen input device

Claims (7)

A sheet-like surface material for a pen input device having an input surface input by a pen.
The transmission image sharpness with an optical comb width of 0.5 mm is set to a value in the range of 30% or more and 100% or less.
On the input surface, the arithmetic mean roughness Ra is set to a value in the range of more than 0 and less than 0.5 μm, and the rolling circle maximum waviness _WEM is set to a value in the range of 5.0 μm or more.
The first particle having an average particle size set to a value in the range of 8 μm or more and 15 μm or less and the second particle having an average particle size set to a value in the range of 0.4 μm or more and less than 0.7 μm are included. A plurality of projecting portions having different sizes are formed on the input surface by the first particle and the second particle protruding outward from the input surface side.
The vibration value calculated by the following formula 1 is 91 dB or more and 103 dB or less due to the peak acceleration of the pen in the region of 0 Hz or more and 5 Hz or less when a straight line having a length of 100 mm is written on the input surface by the pen. Surface material for pen input devices, which is a range value.
[Equation 1]
Vibration (dB) = 20 x log ₁₀ (α / 1 x ^10-5 )
However, α is the acceleration of the pen (m / s ² ). The surface material for a pen input device according to claim 1, wherein the first particles are acrylic particles and the second particles are silica particles . Sheet-shaped base member and
A coating member that covers one surface of the base member is provided.
The coating member has a coating material extending along the one surface of the base member, and each of the first particle and the second particle is dispersed in the coating material , claim 1 or 2. Surface material for pen input devices described in. The surface material for a pen input device according to claim 3 , wherein the surface of the coat member opposite to the base member is the input surface. 3. Claim 3 in which the difference in refractive index between the coating material and the first particles and the difference in refractive index between the coating material and the second particles are set to values in the range of 0 or more and 0.07 or less. Or the surface material for the pen input device according to 4 . The surface material for a pen input device according to any one of claims 3 to 5, wherein the total weight of the first particles added to the coating member is less than the total weight of the second particles added to the coating member. The surface material for a pen input device according to any one of claims 3 to 6, wherein the haze of the coating member is set to a value in the range of 8% or more and 39% or less.

Images