JP7268686B2 - Resin sheet, front plate for image display device using the same, image display device using the same, and transfer sheet - Google Patents

Description

The present invention relates to a resin sheet, an image display device using the same, and a transfer sheet.

A resin sheet having an uneven structure is sometimes placed in front of a display element of an image display device for the purpose of suppressing reflection of external light (providing antiglare properties).

However, when a resin sheet having an uneven structure is used on the surface of the display element, the uneven structure causes a phenomenon (glittering) in which minute variations in luminance appear in image light, resulting in a problem of deterioration in display quality. There is
In particular, high-definition display elements in recent years tend to have more glare, and sufficient anti-glare measures are required.

For example, Patent Documents 1 and 2 have proposed techniques for suppressing glare due to surface unevenness.

JP-A-2002-267818 JP 2015-172834 A

Patent document 1 suppresses glare by increasing the ratio of internal haze to total haze (internal haze/total haze).

Patent Literature 2 suppresses glare without increasing the internal haze more than necessary by preventing the distribution of the inclination angles of the unevenness from biasing toward a specific angle. However, even in Patent Document 2, a predetermined internal haze is imparted to suppress glare (paragraph 0035 of Patent Document 2, Example).

As in Patent Literatures 1 and 2, designs are usually made to provide a predetermined amount of internal haze in order to suppress glare. However, internal haze has the problem of reducing image sharpness. In particular, in the case of an image display device in which the light emitting surface of the display element and the uneven surface of the resin sheet are separated from each other, the reduction in image sharpness due to internal haze poses a serious problem.

The present invention has been made under such circumstances, and it is an object of the present invention to provide a resin sheet and an image display device that suppress glare while suppressing deterioration in image sharpness due to internal haze and have antiglare properties. With the goal. Another object of the present invention is to provide a transfer sheet for producing the resin sheet.

In order to solve the above problems, the present invention provides the following [1] to [3].
[1] A resin sheet having an uneven area on one surface, wherein the internal haze of the area having the uneven area is 3.0% or less, and the cutoff value λc of the uneven area is set to 0.8 mm. When the arithmetic mean roughness of JIS B0601: 1994 at the time is defined as Ra1, and the average spacing of the unevenness of JIS B0601: 1994 when the cutoff value λc of the uneven region is 0.8 mm is defined as Sm1, Ra1 and Sm1 A resin sheet that satisfies the following formulas (1) and (2).
Ra1 [μm] × Sm1 [μm] ≤ 5.00 (1)
0.050 [μm]≦Ra1 (2)
[2] A transfer sheet having a transfer layer on a release sheet, wherein the transfer layer has an uneven area on the side thereof in contact with the release sheet, and satisfies Condition 1 below.
<Condition 1>
After bonding the surface of the transfer sheet on the transfer layer side to a transparent plate having an internal haze of 0%, the release sheet is peeled off, and a sample A is prepared by transferring the transfer layer onto the transparent plate. . The arithmetic mean roughness of JIS B0601: 1994 when the internal haze of the portion having the uneven region of the sample A is 3.0% or less and the cutoff value λc of the uneven region of the sample A is 0.8 mm Ra1, when the cutoff value λc of the uneven region of sample A is set to 0.8 mm and the average spacing of the unevenness of JIS B0601: 1994 is defined as Sm1, Ra1 and Sm1 are expressed by the following formulas (1) and (2) ).
Ra1 [μm] × Sm1 [μm] ≤ 5.00 (1)
0.050 [μm]≦Ra1 (2)
[3] An image display device having a display element and a front panel disposed on the light emitting surface side of the display element, wherein the resin sheet according to [1] is used as the front panel, and the uneven region is An image display device arranged so that the surface on the side provided faces the side opposite to the display element.

INDUSTRIAL APPLICABILITY The resin sheet and the image display device of the present invention are capable of suppressing glare and imparting antiglare properties while suppressing deterioration in image sharpness due to internal haze. Moreover, by using the transfer sheet of the present invention, the resin sheet can be easily produced.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows one Embodiment of the resin sheet of this invention. FIG. 4 is a cross-sectional view showing another embodiment of the resin sheet of the present invention; It is a top view showing one embodiment of the resin sheet of the present invention. 1 is a cross-sectional view showing one embodiment of a transfer sheet of the present invention; FIG. It is a figure explaining the calculation method of average inclination-angle (theta)a.

Embodiments of the present invention will be described below. In this specification, AA to BB means from AA to BB.
[Resin sheet]
The resin sheet of the present invention has an uneven region on one surface, the internal haze of the portion having the uneven region is 3.0% or less, and the cutoff value λc of the uneven region is 0.8 mm. When the arithmetic mean roughness of JIS B0601: 1994 at the time is defined as Ra1, and the average spacing of the unevenness of JIS B0601: 1994 when the cutoff value λc of the uneven region is 0.8 mm is defined as Sm1, Ra1 and Sm1 satisfies the following formulas (1) and (2).
Ra1 [μm] × Sm1 [μm] ≤ 5.00 (1)
0.050 [μm]≦Ra1 (2)

1 and 2 are cross-sectional views showing an embodiment of a resin sheet 1000 of the present invention.
The resin sheet 1000 of FIGS. 1 and 2 has an uneven area A1 on one surface. Moreover, the resin sheet 1000 of FIGS. 1 and 2 has a smooth area A2 adjacent to the uneven area A1 on the one surface.
Moreover, the resin sheet 1000 of FIG. 1 has the resin layer 10 and the transparent base material 50, and has the uneven|corrugated area|region A1 on the surface at the side of a resin layer. The resin sheet 1000 of FIG. 2 has a transfer layer 100 and an adherend 200. The transfer layer 100 has a resin layer 10, an anchor coat layer 20 and an adhesive layer 30, and has an uneven region on the resin layer side surface. has A1.

<Uneven area>
The resin sheet of the present invention has an uneven area on one surface. As shown in FIGS. 1 and 2, the uneven area A1 may be formed on a part of one surface of the resin sheet 1000, or may be formed on the entire one surface of the resin sheet 1000. . In addition, by forming the uneven area A1 on a part of one surface of the resin sheet 1000, the design of the resin sheet is improved due to the difference in texture between the uneven area A1 and other areas (for example, a smooth area A2 described later). It is preferable in that it can improve
Further, the other surface of the resin sheet may be partially or wholly formed with an uneven region, but from the viewpoint of improving image clarity, the other surface is preferably smooth. In the present specification, "smooth" means that the arithmetic mean roughness Ra1 is 0.030 µm or less, preferably 0.020 µm or less, more preferably 0.010 µm or less.

<<Internal Haze>>
The resin sheet of the present invention is required to have an internal haze of 3.0% or less at portions having uneven regions. If the internal haze exceeds 3.0%, it is not possible to suppress the deterioration of image sharpness. In particular, in the case of an image display device in which the light emitting surface of the display element and the uneven surface of the resin sheet are separated from each other, the decrease in image sharpness caused by the internal haze is a serious problem. It is important to make it 0% or less.

In order to facilitate the internal haze of 3.0% or less, each layer constituting the resin sheet preferably does not substantially contain diffusion components such as particles. “Substantially free” means that the content of diffusion components such as particles in each layer is 0.1% by mass or less, more preferably 0.01% by mass or less, and still more preferably 0% by mass. be. In addition, if the ratio of the refractive index of the particles to the refractive index of the resin constituting the layer is 1.00, the particles may be contained.
In addition, in order to easily reduce the internal haze to 3.0% or less, it is preferable that the interface between each layer constituting the resin sheet is smooth.

The internal haze of a portion of the resin sheet having an uneven region is preferably 1.5% or less, more preferably 0.5% or less, even more preferably 0.2% or less, and 0%. It is even more preferable to have

The internal haze can be measured by flattening the surface unevenness of the uneven area by, for example, attaching a transparent sheet onto the uneven area, and can be measured, for example, by the method described in Examples.
In this specification, internal haze, total haze, arithmetic average roughness Ra, average spacing between unevenness Sm, ten-point average roughness Rz, average tilt angle θa, and transmission image clarity are evaluated visually for abnormalities such as dust and scratches. A sample cut out from a point without a point is prepared, and the average value of the measured values at arbitrary 20 points without defects or abnormal points is taken.

<<All Haze>>
The resin sheet of the present invention preferably has a total haze of 1.0 to 15.0%, more preferably 2.0 to 10.0%, and more preferably 3.0 to 7.5%. More preferred.
By setting the total haze to 1.0% or more, the anti-glare property can be easily improved, and by setting the total haze to 15.0% or less, it is possible to easily suppress deterioration of image sharpness.

<<Surface shape>>
The resin sheet of the present invention has an arithmetic mean roughness Ra1 of JIS B0601: 1994 when the cutoff value λc of the uneven region is 0.8 mm, and JIS when the cutoff value λc of the uneven region is 0.8 mm. When the average interval of unevenness in B0601:1994 is defined as Sm1, Ra1 and Sm1 must satisfy the following formulas (1) and (2).
Ra1 [μm] × Sm1 [μm] ≤ 5.00 (1)
0.050 [μm]≦Ra1 (2)

The unevenness of the uneven region corresponds to a lens for the pixel of the display element. As a result of intensive research by the present inventors, when the arithmetic mean roughness Ra is large, the thickness of the unevenness in the uneven region (in other words, the thickness of the lens) tends to increase and the glare tends to deteriorate. It has been found that when the interval Sm is large, the interval between the irregularities in the irregular region (in other words, the diameter of the lens) tends to increase and the glare tends to be aggravated. As a result of further research by the present inventors, although glare cannot be improved by adjusting Ra and Sm alone, glare can be improved by adjusting the product of Ra and Sm without relying on internal haze. I found out.

When Ra1×Sm1 exceeds 5.00 and does not satisfy the formula (1), the thickness of the lens formed by the unevenness is large and/or the diameter of the lens formed by the unevenness is large. cannot be suppressed.
Ra1×Sm1 is preferably 4.80 or less, more preferably 4.30 or less, and even more preferably 4.00 or less.
If Ra1×Sm1 is too small, the size of the lens formed by the unevenness may be small, and the antiglare property may be insufficient. Therefore, Ra1×Sm1 is preferably 2.00 or more, more preferably 2.50 or more, even more preferably 3.00 or more, and even more preferably 3.20 or more. preferable. The unit of Ra1×Sm1 is [μm ² ].

If Ra1 is less than 0.050 μm and the formula (2) is not satisfied, antiglare properties cannot be improved.
If Ra1 is too large, the thickness of the lens formed by the unevenness increases, which tends to worsen the glare and reduce the sharpness of the image.
Therefore, Ra1 is preferably 0.060 to 0.300 μm, more preferably 0.070 to 0.200 μm, even more preferably 0.080 to 0.130 μm.

The range of Sm is not particularly limited as long as the above formulas (1) and (2) are satisfied, but it is preferably 10 to 100 μm, more preferably 20 to 80 μm, and even more preferably 30 to 70 μm. .

In the resin sheet of the present invention, Rz1 is 0.200 to 1.000 μm when the ten-point average roughness of JIS B0601: 1994 when the cutoff value λc of the uneven region is 0.8 mm is defined as Rz1. more preferably 0.300 to 0.900 μm, even more preferably 0.400 to 0.800 μm.
By setting Rz1 to 0.200 μm or more, defects such as scratches occurring in the uneven region can be made inconspicuous, and by setting Rz1 to 1.000 μm or less, glare can be easily suppressed, Image sharpness can be easily improved.

In the resin sheet of the present invention, θa1 is preferably 0.50 degrees or more, where θa1 is defined as the average inclination angle of the uneven region. By setting θa1 to 0.50 degrees or more, the antiglare property can be easily improved.
Note that if θa1 is too large, the total haze tends to increase. Therefore, θa1 is more preferably 0.50 to 3.00 degrees, more preferably 0.80 to 2.50 degrees, and even more preferably 1.00 to 2.20 degrees.

The average inclination angle θa is a value defined in the instruction manual (1995.07.20 revision) of the surface roughness measuring instrument (trade name: SE-3400) manufactured by Kosaka Laboratory Co., Ltd., and is shown in FIG. , _the arc tangent θa ₌ ^{tan −1} _{{ (} h ₁ +h ₂ +h ₃ + . . . +h _n )/L}. In this specification, the reference length is divided into 1500 points to obtain 1500 points of height data, and the average inclination angle θa is calculated based on the 1500 points of height data.

In the resin sheet of the present invention, Ra1, Sm1 and θa1 preferably satisfy the following formula (3).
1.30×10 ⁻³ ≦Ra1 [μm]/Sm1 [μm]/θa1 (degrees) (3)

Since Ra1 is the average height and Sm1 is the average spacing of the unevenness, it can be said that Ra1/Sm1 approximates the average slope of the unevenness in one cycle. Therefore, although Ra1/Sm1 and θa1 are thought to have a correlation, in reality there is often no correlation between them. This is because θa1 reflects fine unevenness (fine unevenness superimposed on one cycle of unevenness (large unevenness)), whereas Ra1/Sm1 hardly reflects fine unevenness. More specifically, as described above, since the average inclination angle θa is measured by dividing the reference length into 1500, the value tends to increase when there are many minute irregularities. Therefore, even if the unevenness of one period (large unevenness) is similar, θa shows a different value due to the difference in the amount of fine unevenness superimposed on the unevenness of one period (large unevenness).
From the above, it can be said that when Ra1/Sm1/θa1 is small, the ratio of fine unevenness is high, and when Ra1/Sm1/θa1 is large, the ratio of fine unevenness is small.
When the resin sheet satisfies the above formula (3), it is possible to reduce the ratio of fine unevenness and further suppress the deterioration of image clarity, further suppress whitening, and improve the fineness of the appearance. can be improved.

“Ra1 [μm]/Sm1 [μm]/θa1 (degrees)” is more preferably 1.33×10 ⁻³ or more, further preferably 1.35×10 ⁻³ or more. Although the upper limit of "Ra1 [μm]/Sm1 [μm]/θa1 (degrees)" is not particularly limited, it is usually 1.70×10 ⁻³ or less, preferably 1.60×10 ⁻³ or less.

In the resin sheet of the present invention, Ra1 and Rz1 preferably satisfy the following formula (4).
3.0≦Rz1/Ra1≦10.0 (4)

Rz1/Ra1 is a parameter that serves as an index of the randomness of unevenness (the higher the Rz1/Ra1, the higher the randomness). By setting Rz1/Ra1 to 10.0 or less, it is possible to suppress glare and improve the fineness of the appearance. Further, by setting Rz1/Ra1 to 3.0 or more, it is possible to make defects in the uneven region less noticeable.

Rz1/Ra1 is more preferably 4.0 to 8.0, even more preferably 5.0 to 7.5.

<<Transmission Image Clarity>>
In the resin sheet of the present invention, the width of the optical comb is 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm and 2.0 mm, and the portions having the uneven regions are prepared according to JIS K7374:2007. The transmitted image sharpness was measured, C _0.125 for transmitted image sharpness with an optical comb width of 0.125 mm, C _0.25 for an optical comb width of 0.25 mm, and an optical comb width of 0.5 mm. When defining the transmission image clarity of C 0.5 as C _0.5 , the transmission image clarity with an optical comb width of 1.0 mm as C _1.0 , and the transmission image clarity with an optical comb width of 2.0 mm as C _2.0 , C _0.125 , C _0.25 , C _0.5 , C _1.0 and C _2.0 is preferably 300% or more.
By making the sum of C _0.125 , C _0.25 , C _0.5 , C _1.0 and C _2.0 300% or more, it is possible to easily suppress deterioration of image sharpness. The sum of C _0.125 , C _0.25 , C _0.5 , C _1.0 and C _2.0 is more preferably 315% or more, even more preferably 325% or more. Although the upper limit of the sum of C _0.125 , C _0.25 , C _0.5 , C _1.0 and C _2.0 is not particularly limited, it is usually 450% or less, preferably 435% or less.

<<Total light transmittance>>
The resin sheet of the present invention preferably has a total light transmittance of 50% or more, more preferably 70% or more, at a portion having an uneven region, measured in accordance with JIS K7361-1:1997. More preferably, it is 90% or more.

<Smooth area>
As shown in FIGS. 1 and 2, the resin sheet of the present invention preferably has a smooth area A2 adjacent to the uneven area A1 on the one surface.
By providing the smooth area A2 adjacent to the uneven area A1, the surface of the resin sheet is given a difference in texture based on the difference in gloss between the two areas, and the design of the resin sheet can be improved.

Arrangement|positioning of uneven|corrugated area|region A1 and smooth area|region A2 is arbitrary. For example, a configuration in which one independent uneven area A1 is arranged and a smooth area A2 surrounding the uneven area A1 is arranged (type 1 (configuration in FIGS. 1 to 3)); , a configuration in which uneven regions A1 are arranged surrounding the smooth regions A2 (type 2); a configuration in which a plurality of independent uneven regions A1 are arranged, and smooth regions A2 are arranged around the plurality of uneven regions A1 (type 3) ); a structure (type 4) in which a plurality of independent smooth regions A2 are arranged and an uneven region A1 is arranged around the plurality of smooth regions A2; Of the four types described above, types 1 and 2 are preferable in that the effects of the present invention can be easily recognized.

The ratio between the area (S1) of the uneven area A1 and the area (S2) of the smooth area A2 is not particularly limited because it changes depending on the design to be imparted, but the difference in texture between the two areas is made clear. From the point of view, it is preferable that 0.1≦S1/S2≦10.0. Further, from the viewpoint of clarifying the difference in texture between the two regions while exhibiting the effects of the present invention over a wide range of the resin sheet, it is more preferable that 1.0 ≤ S1/S2 ≤ 10.0, More preferably, 1.5≦S1/S2≦7.5.

The smooth area A2 may be wholly light-transmitting, or wholly light-shielding, or may be a mixture of light-transmitting and light-shielding areas. good too.

When the arithmetic mean roughness of the smooth region A2 is Ra2, Ra2 is preferably 0.030 μm or less, more preferably 0.020 μm or less, and even more preferably 0.010 μm or less.

The difference between Ra1 and Ra2 (Ra1-Ra2) is preferably 0.020 μm or more, more preferably 0.030 μm or more, and even more preferably 0.050 μm or more.
By setting Ra1−Ra2 to 0.020 μm or more, the difference in texture between the uneven area A1 and the smooth area A2 can be easily recognized.

<Method for manufacturing resin sheet>
The layer structure of the resin sheet includes, for example, a single-layer structure of a resin layer having an uneven region on one surface, and a multilayer structure in which another layer is laminated on the resin layer.
Such a resin sheet can be produced, for example, by the following methods (A) and (B). The method (B) below is preferable in that it can eliminate the substrate that causes iridescent unevenness (rainbow-like unevenness caused by light passing through a substrate having birefringence).
(A) Imprinting using a plate.
(B) Transfer using a transfer sheet having a transfer layer on a release sheet.

The details of the composition of each layer constituting the resin sheet will be described in detail after the description of the manufacturing method.

<<Resin sheet manufacturing method (A)>>
The production method (A) above specifically includes the following steps (A1) and (A2).
(A1) A step of applying a coating liquid for forming a resin layer on a transparent substrate to form a coating film.
(A2) A step of pressing a plate against the coating film to shape the coating film.

Step (A1) is a step of applying a coating liquid for forming a resin layer onto a transparent substrate to form a coating film. The resin layer-forming coating liquid contains at least a resin component. The details of the composition of the resin layer-forming coating liquid will be described later.
As means for applying the resin layer-forming coating liquid, general-purpose applying means selected from gravure coating, comma coating, die coating, bar coating, and the like may be employed.
The resin layer-forming coating liquid may contain a solvent. One or more of general-purpose solvents can be used as the solvent. When the resin layer-forming coating liquid contains a solvent, step (A1) preferably includes a drying step.

When the resin component of the resin layer-forming coating liquid contains an ionizing radiation-curable compound, from the viewpoint of facilitating adjustment of the surface shape of the resin layer by the mold, it is preferable not to irradiate ionizing radiation before the start of step (A2). . That is, when the resin component contains an ionizing radiation-curable compound, it is preferable not to irradiate ionizing radiation in step (A1).

When another layer is provided between the transparent substrate of the resin sheet and the resin layer, a step of forming another layer on the transparent substrate may be performed before step (A1).

Step (A2) is a step of pressing a plate against the coating film to shape the coating film.
Here, by using a plate having a shape complementary to the surface shape of the resin sheet as the plate, a resin layer having a desired surface shape can be formed.

When the resin component contains an ionizing radiation-curable compound, ionizing radiation may be irradiated after the step (A2) (after the plate is separated from the coating surface), but the surface shape of the plate may be changed to the surface of the resin layer. From the viewpoint of accurate shaping, it is preferable to irradiate the ionizing radiation simultaneously with the step (A2).
In addition, when the ionizing radiation is irradiated simultaneously with the step (A2), it is preferable to irradiate from the transparent substrate side.

From the viewpoint of continuous productivity, the plate used in the step (A2) is preferably obtained by shaping the surface of a roll, more preferably by shaping the surface of a metal roll. Surface materials of the metal roll include copper, nickel, chromium, alumina and the like. These metals are preferably plated as required.

As the plate in step (A2), a plate having a shape different from the surface shape of the resin sheet is used, and after step (A2), the step of forming a second resin layer on the resin layer (step (A3)) is performed. you can go By forming the second resin layer, Ra tends to decrease and Sm tends to increase, and the rate of increase in Sm tends to be greater than the rate of decrease in Ra. Therefore, the above formulas (1) and (2) can be adjusted according to the thickness of the second resin layer. Moreover, by forming the second resin layer, Ra and θa tend to be smaller, and the decrease rate of θa tends to be greater than that of Ra. Also, the rate of decrease in θa tends to be greater than the rate of increase in Sm described above. Therefore, by forming the second resin layer, the above formula (3) can be easily satisfied.

When a peelable material is used as the transparent substrate, the transparent substrate may be peeled off from the resin layer after step (A2) to form a single resin layer.

The plate used in step (A2) and step (B0-2) described later is obtained by engraving the surface of the cylinder into a desired shape by, for example, etching, sandblasting, cutting and laser processing, or a combination thereof. be able to. Alternatively, it can be obtained by preparing a plate having the same shape as that to be given to the plate by laser engraving, stereolithography, etc., and winding this reversed version around the surface of a cylinder.

Among the means for preparing the plate, sandblasting is preferable from the viewpoint that the ranges of formulas (1) and (2) can be easily controlled.
In sandblasting, for example, the material of the cylinder surface, the particle size of the abrasive, the shape of the abrasive, the material of the abrasive, the number of times the abrasive collides with the cylinder, the distance between the injection nozzle and the cylinder, the diameter of the injection nozzle, and the workpiece. The irregular shape can be adjusted by controlling the angle of the injection nozzle with respect to the object, the injection pressure, the injection frequency, and the like.

Among the control means described above, the abrasive shape, particle size and injection pressure are the most effective and simple to control the equations (1) and (2).
First, when the particle size of the abrasive is increased, both Ra1 and Sm1 tend to increase. Conversely, when the particle size of the abrasive is decreased, both Ra1 and Sm1 tend to decrease. Therefore, if only the formula (1) is taken into account, the particle size of the abrasive should be reduced, but when the particle size of the abrasive is reduced, it becomes difficult to satisfy the formula (2).
Next, when the injection pressure is increased, the particles are deeply embedded and Ra1 increases, while Sm1 hardly changes.
In addition, by making the shape of the abrasive spherical, it is possible to obtain a smooth irregular shape without a specific shape, so that the surface shape can be easily adjusted by the particle size of the abrasive and the injection pressure.
From the above, it is preferable to use a spherical abrasive and increase the injection pressure while reducing the particle diameter of the abrasive in order to easily satisfy the formulas (1) and (2).

In order to easily satisfy the formulas (1) and (2), it is possible to perform the step (A3) described above and the step (B0-3) described later while using the plate prepared by sandblasting as described above. preferable.

<<Resin sheet manufacturing method (B)>>
The production method (B) above specifically includes the following steps (B1) to (B3).
(B1) A step of obtaining a transfer sheet by forming a transfer layer containing a resin layer on a release sheet.
(B2) A step of obtaining a laminate in which the transfer layer side surface of the transfer sheet and the adherend are brought into close contact with each other.
(B3) a step of separating the release sheet of the transfer sheet from the laminate;

Step (B1) is a step of obtaining a transfer sheet by forming a transfer layer containing a resin layer on a release sheet.
Here, by using a release sheet having a shape complementary to the surface shape of the resin sheet as the release sheet, the surface shape of the transfer layer (≈the surface shape of the resin sheet) can be made into a desired shape.

Examples of the configuration of the transfer layer including the resin layer include the following configurations (Y1) to (Y6). In (Y1) to (Y6) below, "/" indicates the interface between layers, and the closer to the left, the closer to the release sheet.
(Y1) single layer of resin layer (Y2) resin layer/adhesive layer (Y3) resin layer/anchor coat layer/adhesive layer (Y4) antireflection layer/resin layer (Y5) antireflection layer/resin layer/adhesion Agent layer (Y6) antireflection layer/resin layer/anchor coat layer/adhesive layer

Each layer constituting the transfer layer can be formed by applying a coating liquid constituting each layer by a general-purpose coating means selected from gravure coating, comma coating, die coating, bar coating, etc., and drying and curing as necessary. .

The release sheet used in step (B1) can be produced, for example, by the following steps (B0-1) to (B0-2).
(B0-1) A step of applying a coating liquid for forming an uneven layer containing an ionizing radiation-curable resin composition onto a support to form a coating film containing the ionizing radiation-curable resin composition.
(B0-2) A step of pressing a plate against the coating film and simultaneously irradiating it with ionizing radiation to cure the shaped uneven layer.

Here, by using a plate having a shape complementary to the surface shape of the release sheet (≈a plate having the same shape as the surface shape of the transfer layer) as the plate in step (B0-2), the desired surface shape can be obtained. It is possible to obtain a release sheet provided with.

From the viewpoint of continuous productivity, the plate used in the step (B0-2) is preferably obtained by shaping the surface of a roll-like material, more preferably by shaping the surface of a metal roll. Surface materials of the metal roll include copper, nickel, chromium, alumina and the like. These metals are preferably plated as required.

As the plate in the step (B0-2), a plate having a shape different from the surface shape of the release sheet is used, and after the step (B0-2), the step of forming a release layer on the uneven layer (step ( B0-3)) may be performed. By forming the release layer, Ra tends to decrease and Sm tends to increase, and the rate of increase in Sm tends to be greater than the rate of decrease in Ra. Therefore, the above formulas (1) and (2) can be adjusted according to the thickness of the release layer. Also, the formation of the release layer tends to reduce Ra and θa, and the reduction rate of θa is greater than that of Ra. Also, the rate of decrease in θa tends to be greater than the rate of increase in Sm described above. Therefore, by forming the release layer, the above formula (3) can be easily satisfied.

Step (B2) is a step of obtaining a laminate in which the transfer layer side surface of the transfer sheet and the adherend are brought into close contact with each other. Step (B3) is a step of separating the release sheet of the transfer sheet from the laminate.

In steps (B2) and (B3), known transfer methods can be used.
For example, (i) a method of preparing a laminate in which the transfer layer side surface of the transfer sheet is brought into close contact with a preformed adherend, and separating (peeling) the release sheet of the transfer sheet from the laminate, ( ii) A method of forming a laminate integrated (adhered) with the transfer layer side surface of the transfer sheet when injection molding the adherend, and separating (peeling) the release sheet of the transfer sheet from the laminate. [in-mold molding (injection molding simultaneous transfer decoration method)] and the like. Among these methods, in-mold molding (injection molding simultaneous transfer decoration method) is preferable because the resin sheet can be formed into a complicated shape such as a three-dimensional curved surface.

As an embodiment of the in-mold molding of (ii) above,
(a) a step of arranging the transfer sheet so that the transfer layer side surface faces the inside of the mold for in-mold molding;
(b) a step of injecting a resin into the mold for in-mold molding;
(c) a step of obtaining a laminate in which the transfer layer side surface of the transfer sheet and the resin are integrated (adhered);
(d) a step of separating (peeling) the release sheet of the transfer sheet from the laminate after removing the laminate from the mold.
When the layer (for example, resin layer) constituting the transfer layer is in a semi-cured state, it is preferable to completely cure the semi-cured layer by irradiating ultraviolet rays after the step (d) is completed.

<Layer structure of resin sheet>
Examples of the layer structure of the resin sheet include the following structures (Z1) to (Z4).
In the following (Z1) to (Z4), "/" indicates the interface of the layers, the closer to the left is the surface side, and the uneven region is formed on the surface of the layer located on the leftmost side. means.
Further, examples of the transfer layer containing the resin layer of (Z4) below include the structures of (Y1) to (Y6) above. When the above (Y1) to (Y6) are applied to the transfer layer containing the resin layer (Z4) below, the layer located on the right side of (Y1) to (Y6) is arranged on the adherend side of (Z4).
(Z1) single layer of resin layer (Z2) resin layer/transparent substrate (Z3) second resin layer/resin layer/transparent substrate (Z4) transfer layer containing resin layer/adherend

The resin sheet of the present invention has an internal haze of 3.0% or less at a portion having an uneven region. Therefore, as described above, it is preferable that each layer constituting the resin sheet such as the resin layer does not substantially contain diffusion components such as particles.

<<resin layer>>
From the viewpoint of scratch resistance, the resin layer preferably contains a cured product of a curable resin composition as a main component. The main component means 50% by mass or more of the total solid content constituting the resin layer, and the ratio is preferably 70% by mass or more, more preferably 80% by mass or more, and 90% by mass or more. is even more preferable.
As used herein, the term "resin layer" means both the resin layer formed by the method (A) above and the resin layer formed by the method (B) above, unless otherwise specified. and

The cured product of the curable resin composition includes a cured product of a thermosetting resin composition and a cured product of an ionizing radiation-curable resin composition. Among these, a cured product of an ionizing radiation-curable resin composition is preferable.
Further, the resin layer may contain a thermoplastic resin, but the amount thereof is preferably very small from the viewpoint of improving scratch resistance. Specifically, the content of the thermoplastic resin in the resin layer is preferably less than 5% by mass, more preferably less than 1% by mass, even more preferably less than 0.1% by mass, 0% by mass is even more preferable.
Hereinafter, the cured product of the curable resin composition and the thermoplastic resin may be referred to as "resin component".

A thermosetting resin composition is a composition containing at least a thermosetting resin, and is a resin composition that is cured by heating. Thermosetting resins include acrylic resins, urethane resins, phenol resins, urea melamine resins, epoxy resins, unsaturated polyester resins, silicone resins, and the like. If necessary, a curing agent is added to these curable resins in the thermosetting resin composition.

The ionizing radiation-curable resin composition is a composition containing a compound having an ionizing radiation-curable functional group (hereinafter also referred to as an "ionizing radiation-curable compound"). Examples of ionizing radiation-curable functional groups include ethylenically unsaturated bond groups such as (meth)acryloyl groups, vinyl groups, and allyl groups, epoxy groups, and oxetanyl groups.
A compound having an ethylenically unsaturated bond group is preferable as the ionizing radiation-curable resin. From the viewpoint of suppressing damage to the resin layer in the process of manufacturing the transfer sheet, the ionizing radiation-curable resin is more preferably a compound having two or more ethylenically unsaturated bond groups. Polyfunctional (meth)acrylate compounds having two or more saturated bond groups are more preferred. Both monomers and oligomers can be used as polyfunctional (meth)acrylate compounds.
Ionizing radiation means an electromagnetic wave or a charged particle beam that has an energy quantum capable of polymerizing or cross-linking molecules, and usually ultraviolet (UV) or electron beam (EB) is used. Electromagnetic waves such as X-rays and γ-rays, and charged particle beams such as α-rays and ion beams can also be used.

Among polyfunctional (meth)acrylate compounds, bifunctional (meth)acrylate monomers include ethylene glycol di(meth)acrylate, bisphenol A tetraethoxy diacrylate, bisphenol A tetrapropoxy diacrylate, 1,6-hexane. diol diacrylate and the like.
Trifunctional or higher (meth)acrylate monomers include, for example, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, di Examples include pentaerythritol tetra(meth)acrylate and isocyanuric acid-modified tri(meth)acrylate.
Further, the (meth)acrylate-based monomer may have a partially modified molecular skeleton, and may be modified with ethylene oxide, propylene oxide, caprolactone, isocyanuric acid, alkyl, cyclic alkyl, aromatic, bisphenol, or the like. can also be used.

Examples of polyfunctional (meth)acrylate oligomers include acrylate polymers such as urethane (meth)acrylate, epoxy (meth)acrylate, polyester (meth)acrylate, and polyether (meth)acrylate.
Urethane (meth)acrylates are obtained, for example, by reacting polyhydric alcohols and organic diisocyanates with hydroxy (meth)acrylates.
Preferred epoxy (meth)acrylates are (meth)acrylates obtained by reacting tri- or more functional aromatic epoxy resins, alicyclic epoxy resins, aliphatic epoxy resins, etc. with (meth)acrylic acid, bifunctional (Meth)acrylates obtained by reacting the above aromatic epoxy resins, alicyclic epoxy resins, aliphatic epoxy resins, etc. with polybasic acid and (meth)acrylic acid, and bifunctional or higher aromatic epoxy resins, It is a (meth)acrylate obtained by reacting an alicyclic epoxy resin, an aliphatic epoxy resin, or the like with a phenol and (meth)acrylic acid.
The ionizing radiation-curable resins may be used singly or in combination of two or more.

When the ionizing radiation-curable resin is an ultraviolet-curable resin, the resin layer-forming coating liquid preferably contains additives such as a photopolymerization initiator and a photopolymerization accelerator.
Examples of the photopolymerization initiator include one or more selected from acetophenone, benzophenone, α-hydroxyalkylphenone, Michler's ketone, benzoin, benzyldimethylketal, benzoylbenzoate, α-acyloxime ester, thioxanthone, and the like.
In addition, the photopolymerization accelerator can reduce polymerization inhibition by air during curing and increase the curing speed. One or more selected types can be mentioned.

The curable resin composition is kept in a semi-cured state at the time of forming the resin layer. , may be fully cured. By doing so, the conformability of the resin layer to the adherend is improved, so that moldability can be improved.

The thickness of the resin layer is preferably 0.5 to 30 μm, more preferably 1 to 20 μm, even more preferably 3 to 10 μm, from the viewpoint of the balance between surface hardness and moldability.

<<transparent substrate>>
The transparent substrate is mainly used when the resin sheet is produced by the method (A) above.

As the transparent base material, it is preferable that the base material has optical transparency, smoothness, heat resistance, and excellent mechanical strength. Examples of such transparent substrates include polyester, triacetyl cellulose (TAC), cellulose diacetate, cellulose acetate butyrate, polyamide, polyimide, polyethersulfone, polysulfone, polypropylene, polymethylpentene, polyvinyl chloride, and polyvinyl acetal. , polyetherketone, polymethyl methacrylate, polycarbonate, polyurethane and amorphous olefin (Cyclo-Olefin-Polymer: COP). The transparent substrate may be a laminate of two or more plastic films.
Of these, stretched, particularly biaxially stretched polyesters (polyethylene terephthalate, polyethylene naphthalate) are preferred from the viewpoint of mechanical strength and dimensional stability. Also, TAC and acrylic are suitable from the viewpoint of light transmittance and optical isotropy. In addition, COP and polyester are suitable because of their excellent weather resistance. In addition, when using a plastic film with an in-plane retardation value of 3,000 to 30,000 nm or a plastic film with a 1/4 wavelength retardation, unevenness in different colors can be observed on the display screen when an image on the liquid crystal display is observed through polarized sunglasses. It is suitable in that it can be prevented.

The thickness of the transparent substrate is preferably 5-300 μm, more preferably 30-200 μm.
In order to improve adhesiveness, the surface of the transparent base material may be subjected in advance to physical treatment such as corona discharge treatment, oxidation treatment, or the like, as well as to application of a paint called an anchor agent or primer.

When the transparent substrate is separated from the resin layer after the step (A2) to form a single resin layer, it is preferable to use a transparent substrate having releasability.

<<Second resin layer>>
The second resin layer is a layer formed on the resin layer mainly for the purpose of adjusting the above formulas (1) and (2) when the resin sheet is produced by the method (A) above. .

From the viewpoint of scratch resistance, the second resin layer preferably contains a cured product of the curable resin composition as a main component. The main component means 50% by mass or more of the total solid content constituting the second resin layer, and the ratio is preferably 70% by mass or more, more preferably 80% by mass or more, and 90% by mass. % or more is even more preferable.
The curable resin composition used for forming the second resin layer may be the same as the curable resin composition used for forming the resin layer.

The thickness of the second resin layer is preferably 0.10 to 6.50 μm, more preferably 0.50 to 6.00 μm, even more preferably 0.70 to 5.50 μm. By setting the thickness of the second resin layer within the above range, the above formulas (1) and (2) can be easily satisfied.

<<transfer layer>>
The transfer layer is a layer formed on the adherend when the resin sheet is produced by the method (B) above. Specific examples of the layer structure of the transfer layer include the above (Y1) to (Y6).
Embodiments of the composition and thickness of the resin layer included in the transfer layer are as described above.

<<<adhesive layer>>>
The adhesive layer is disposed on the adherend side of the transfer layer, and has a role of improving the adhesion between the adherend such as a resin molding and the transfer layer, thereby improving the transfer operation.

The adhesive layer preferably uses a heat-sensitive or pressure-sensitive resin suitable for the material of the adherend. For example, when the material of the adherend is an acrylic resin, it is preferable to use an acrylic resin. If the material of the adherend is polyphenylene oxide/polystyrene resin, polycarbonate resin, or styrene resin, use acrylic resin, polystyrene resin, polyamide resin, polyester resin, etc. that have affinity with these resins. is preferably used. Furthermore, when the material of the adherend is polypropylene resin, it is preferable to use chlorinated polyolefin resin, chlorinated ethylene-vinyl acetate copolymer resin, cyclized rubber, and coumarone-indene resin.
When the adherend is injection molded, the adhesive layer preferably has heat sensitivity (heat sealability).

Additives such as ultraviolet absorbers and infrared absorbers may be added to the adhesive layer.
The thickness of the adhesive layer is preferably 0.1 to 10 μm, more preferably 0.5 to 5 μm.

<<<anchor coat layer>>>
The anchor coat layer is a layer provided as necessary to improve heat resistance when placed in a high-temperature environment such as in-mold molding. The anchor coat layer is preferably formed between the resin layer and the adhesive layer.

The anchor coat layer preferably contains a cured product of the curable resin composition.
Examples of the curable resin composition for the anchor coat layer include the same curable resin compositions as exemplified for the resin layer.
The thickness of the anchor coat layer is preferably 0.1 to 6 μm, more preferably 0.5 to 5 μm.

<<<Antireflection layer>>>
Among the layers constituting the transfer layer, the antireflection layer is located on the farthest side from the adherend.
Examples of the antireflection layer include a single-layer structure of a low refractive index layer and a two-layer structure of a high refractive index layer and a low refractive index layer (in the case of the two-layer structure, the high refractive index layer is arranged on the adherend side). Furthermore, an antireflection layer may be formed with three or more layers.

The refractive index of the low refractive index layer is preferably 1.28 to 1.40, more preferably 1.32 to 1.38.
The thickness of the low refractive index layer is preferably 80 to 120 nm, more preferably 85 to 110 nm, even more preferably 90 to 105 nm.

Techniques for forming a low refractive index layer can be broadly classified into a wet method and a dry method. Wet methods include a method of forming by a sol-gel method using a metal alkoxide or the like, a method of forming by coating a low refractive index resin such as a fluororesin, and a method of forming a low refractive index resin containing low refractive index particles in a resin composition. A method of forming by applying a coating liquid for forming a refractive index layer may be mentioned. As the dry method, there is a method of selecting particles having a desired refractive index from low refractive index particles described later and forming them by a physical vapor deposition method or a chemical vapor deposition method.
The wet method is superior in terms of production efficiency, and among the wet methods, it is preferable to use a coating liquid for forming a low refractive index layer containing low refractive index particles in a binder resin composition. As the binder resin composition, for example, the curable resin composition exemplified for the resin layer can be used.

The low-refractive-index particles may be particles made of inorganic compounds such as silica and magnesium fluoride, or particles made of organic compounds. Therefore, particles having a structure having voids are preferably used.
Particles having a structure with voids have fine voids inside and are filled with gas such as air having a refractive index of 1.0, so that the refractive index of the particles itself is low. there is Examples of such particles having voids include inorganic or organic porous particles, hollow particles, and the like. For example, porous silica, hollow silica particles, or porous polymer particles using an acrylic resin, etc. and hollow polymer particles.
The average particle size of the primary particles of the low refractive index particles is preferably 5 to 200 nm, more preferably 5 to 100 nm, even more preferably 10 to 80 nm.

The high refractive index layer preferably has a refractive index of 1.55 to 1.85, more preferably 1.56 to 1.70.
Also, the thickness of the high refractive index layer is preferably 200 nm or less, more preferably 50 to 180 nm.

The high refractive index layer can be formed, for example, from a high refractive index layer coating liquid containing a binder resin composition and high refractive index particles. As the binder resin composition, for example, the curable resin composition exemplified for the hard coat layer can be used.

High refractive index particles include antimony pentoxide (1.79), zinc oxide (1.90), titanium oxide (2.3 to 2.7), cerium oxide (1.95), tin-doped indium oxide (1.95). 95-2.00), antimony-doped tin oxide (1.75-1.85), yttrium oxide (1.87) and zirconium oxide (2.10).
The average particle size of the primary particles of the high refractive index particles is preferably 5 to 200 nm, more preferably 5 to 100 nm, even more preferably 10 to 80 nm.

<< adherend >>
Examples of adherends include formed bodies made of metals, glass, ceramics, resins, and the like. Among these, glass and resin moldings are preferable, and resin moldings are more preferable because the effects of the present invention are easily exhibited.
The shape of the adherend may be a flat plate shape or a three-dimensional shape having a curved surface or the like. Also, the adherend may be colored.

The resin molded body is preferably formed from an injection-moldable thermoplastic resin or thermosetting resin.
When the resin sheet is manufactured by in-mold molding, it is preferable to use a thermoplastic resin for the resin molding as the adherend. Examples of such thermoplastic resins include polystyrene resins, polyolefin resins, ABS resins (including heat-resistant ABS resins), AS resins, AN resins, polyphenylene oxide resins, polycarbonate resins, polyacetal resins, acrylic resins, Examples include polyethylene terephthalate-based resins, polybutylene terephthalate-based resins, polysulfone-based resins, and polyphenylene sulfide-based resins. Of these, polycarbonate-based resins are preferred because of their good impact resistance.

The thickness of the adherend is not particularly limited, and may be appropriately determined according to the application. When the resin sheet is used as the front plate of the display element, the thickness is preferably 0.3 to 5.0 mm, more preferably 1.0 to 2.5 mm, from the viewpoint of the balance between strength and thinning. .

<<Other Layers>>
The resin sheet may have other layers such as an antifouling layer, a printing layer and an antistatic layer.

<Application>
The resin sheet of the present invention can be used, for example, as a front plate of a display element.
Examples of display elements include liquid crystal display elements, EL (inorganic EL, organic EL) display elements, plasma display elements, and LED display elements (such as micro LEDs). The liquid crystal display element may be an in-cell touch panel liquid crystal display element having a touch panel function inside the element.

[Transfer sheet]
The transfer sheet of the present invention has a transfer layer on a release sheet, and the transfer layer has an uneven area on the side in contact with the release sheet, and satisfies Condition 1 below.
<Condition 1>
After bonding the surface of the transfer sheet on the transfer layer side to a transparent plate having an internal haze of 0%, the release sheet is peeled off, and a sample A is prepared by transferring the transfer layer onto the transparent plate. . The arithmetic mean roughness of JIS B0601: 1994 when the internal haze of the portion having the uneven region of the sample A is 3.0% or less and the cutoff value λc of the uneven region of the sample A is 0.8 mm Ra1, when the cutoff value λc of the uneven region of sample A is set to 0.8 mm and the average spacing of the unevenness of JIS B0601: 1994 is defined as Sm1, Ra1 and Sm1 are expressed by the following formulas (1) and (2) ).
Ra1 [μm] × Sm1 [μm] ≤ 5.00 (1)
0.050 [μm]≦Ra1 (2)

FIG. 4 is a cross-sectional view showing one embodiment of the transfer sheet 300 of the present invention.
A transfer sheet 300 in FIG. 4 has a transfer layer 100 on a release sheet 70 . The release sheet 70 is composed of a support 71, an uneven layer 72 and a release layer 73. The surface of the transfer layer 100 on the side in contact with the release sheet 70 is adjacent to the uneven area A1' and the uneven area A1'. and a smooth region A2'. In addition, the transfer layer 100 has a resin layer 10, an anchor coat layer 20 and an adhesive layer 30 from the release sheet side.

In condition 1 of the transfer sheet of the present invention, the technical idea of defining the ranges of internal haze, Ra1×Sm1 and Ra1 is the technique of defining the ranges of internal haze, Ra1×Sm1 and Ra1 in the resin sheet of the present invention described above. It is the same as thought.
The surface shape and optical properties of Sample A produced from the transfer sheet are preferably in the same ranges as the above-described preferred ranges of the surface shape and optical properties of the resin sheet. For example, in sample A, the average inclination angle θa1 of the uneven region is preferably 0.50 degrees or more, and Ra1 [μm]/Sm1 [μm]/θa1 (degrees) is 1.30×10 ⁻³ or more. is preferred. Moreover, it is preferable that the sample A has a smooth region adjacent to the uneven region on the one surface.

<Release sheet>
The release sheet has an uneven area on the surface thereof in contact with the transfer layer.
The release sheet is peeled off after the transfer layer has been transferred to an adherend such as a resin molding, and a shape complementary to the surface shape of the release sheet is formed on the surface of the transfer layer (≒ surface of the resin sheet). be. That is, the surface shape of the release sheet has a complementary relationship with the surface shape of the resin sheet. The positive and negative of the surface unevenness of the release sheet and the surface unevenness of the resin sheet are reversed, but the arithmetic average roughness Ra and the average interval Sm of the unevenness are substantially the same. That is, the arithmetic mean roughness Ra and the average spacing Sm of the uneven regions of the release sheet are substantially the same as the arithmetic mean roughness Ra of the uneven regions and the average spacing Sm of the unevenness of the resin sheet obtained from the transfer sheet. .

The release sheet 70 preferably has a support 71, an uneven layer 72 and a release layer 73, as shown in FIG. By configuring the release sheet in this manner, it is possible to easily satisfy Condition 1, and to easily set Ra1 [μm]/Sm1 [μm]/θa1 (degrees) within the above range.

The release sheet may be a single layer of the support, may have a two-layer structure of the support and the uneven layer, or may have a structure including the support and the uneven layer. And you may have other layers other than a mold release layer.
Other layers include an antistatic layer. By having an antistatic layer, it is possible to suppress peel electrification when the release sheet is peeled off, and to improve transfer workability.

<<Support>>
Supports constituting the release sheet include polyolefin resins such as polyethylene and polypropylene, vinyl resins such as polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene/vinyl acetate copolymer, and ethylene/vinyl alcohol copolymer. Resins, polyester resins such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate, acrylic resins such as poly(methyl meth)acrylate and poly(ethyl meth)acrylate, styrene resins such as polystyrene, nylon 6 or nylon A plastic film made of a resin such as a polyamide-based resin represented by 66 is exemplified.
Among these plastic films, a biaxially stretched polyester film is preferable because it is excellent in heat resistance and dimensional stability, and is excellent in aptitude for alignment during transfer.

The thickness of the support is preferably 12 to 150 μm, more preferably 25 to 100 μm, from the viewpoints of formability, conformability and handling.
In addition, the surface of the support may be subjected in advance to an easy-adhesion treatment in order to enhance adhesion to the uneven layer or the like.

<<Uneven layer>>
The uneven layer preferably contains a cured product of a curable resin composition as a main component. The main component means 50% by mass or more of the total solid content constituting the uneven layer, and the ratio is preferably 70% by mass or more, more preferably 80% by mass or more, and 90% by mass or more. is even more preferable.
The curable resin composition used for the uneven layer may be the same as the curable resin composition exemplified for the resin layer.

Although the thickness of the uneven layer is not particularly limited, it is preferably 1 to 15 μm, more preferably 2 to 12 μm.

<<Release layer>>
It is preferable that the release layer is mainly composed of a resin.
The resin of the release layer is not particularly limited as long as it has a predetermined film strength and low adhesion to the transfer layer. A cured product of a curable resin composition and the like can be mentioned. Specifically, fluorine-based resins, silicone-based resins, acrylic-based resins, polyester-based resins, polyolefin-based resins, polystyrene-based resins, polyurethane-based resins, cellulose-based resins, vinyl chloride-vinyl acetate-based copolymer resins, nitrocellulose etc.
Among these, a cured product of a thermosetting resin composition is preferred, and a thermosetting resin composition containing acrylic polyol and isocyanate is more preferred.

The release layer may further contain a release agent to improve releasability. Examples of release agents include waxes such as synthetic waxes and natural waxes. Polyolefin waxes such as polyethylene wax and polypropylene wax are preferable as the synthetic wax.

The thickness of the release layer is preferably 0.10 to 6.50 μm, more preferably 0.50 to 6.00 μm, even more preferably 0.70 to 5.50 μm. By setting the thickness of the release layer within the above range, the condition 1 can be easily satisfied.
The release sheet can be produced, for example, by the steps (B0-1) to (B0-3) described above.

<Transfer layer>
Examples of the transfer layer constituting the transfer sheet include the layer structures (Y1) to (Y6) described above.

[Image display device]
An image display device of the present invention is an image display device having a display element and a front plate disposed on the light emitting surface side of the display element, wherein the front plate is the resin sheet of the present invention described above, It is arranged such that the surface on the side having the uneven area faces the opposite side to the display element.

Examples of display elements include liquid crystal display elements, EL display elements (organic EL display elements, inorganic EL display elements), plasma display elements, and the like, and LED display elements such as micro LED display elements. The liquid crystal display element may be an in-cell touch panel liquid crystal display element having a touch panel function inside the element.

When the display element of the display device is a liquid crystal display element, a backlight is required on the surface of the liquid crystal display element opposite to the resin sheet.

Further, the image display device of the present invention may be an image display device with a touch panel.
As the touch panel, systems such as a resistive film system, a capacitance system, an electromagnetic induction system, an infrared system, and an ultrasonic system can be used.

It is preferable that the distance from the light emitting surface of the display element to the surface of the resin sheet on the side having the uneven area is 2.0 mm or more. If the distance is 2.0 mm or more, the problem of sharpness of the image tends to occur, but by using the resin sheet of the present invention as the front plate, the deterioration of the sharpness of the image can be suppressed.
The distance is more preferably 2.0 to 10.0 mm, even more preferably 2.0 to 5.0 mm.

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. "Parts" and "%" are based on mass unless otherwise specified.

1. Measurements and Evaluations The resin sheets obtained in Examples and Comparative Examples and the surface protection sheets of Reference Examples were subjected to the following measurements and evaluations. The atmosphere for measurement and evaluation was a temperature of 23° C.±5° C. and a humidity of 40 to 65%. In addition, the measurement and evaluation were performed after exposing the target sample to the atmosphere for 30 minutes or more. Table 2 shows the results.

1-1. Total Haze, Internal Haze, Total Light Transmittance The total haze was measured at a portion of the resin sheet having an uneven region in accordance with JIS K-7136:2000. At the same time, the total light transmittance was measured according to JIS K7361-1:1997. In addition, a TAC film having a thickness of 80 μm (internal haze 0%) is attached to the surface of the resin sheet having the uneven region via a transparent adhesive to flatten the uneven shape, thereby reducing the haze caused by the surface shape. A sample that eliminates the influence of The difference between the refractive index of the resin and the transparent adhesive, and the difference between the refractive index of the transparent adhesive and the TAC film was within 0.01. The haze was measured at a location corresponding to the uneven region of the prepared sample to obtain the internal haze at the location having the uneven region of the resin sheet. The light incident surface during haze measurement was on the side of the adherend (the side of the transparent acrylic plate). A haze meter (HM-150, manufactured by Murakami Color Research Laboratory) was used as a measuring device.
The total haze, total light transmittance and internal haze of the surface protection sheet of Reference Example were similarly measured.

1-2. Surface roughness Using a surface roughness measuring instrument (model number: ET-4000L / manufactured by Kosaka Laboratory Co., Ltd.), the arithmetic average of the uneven areas A1 of the resin sheets obtained in Examples and Comparative Examples under the following measurement conditions Roughness Ra1, average spacing of unevenness Sm1, ten-point average roughness Rz1, average inclination angle θa1, and arithmetic average roughness Ra2 of smooth region A2 of the resin sheets obtained in Examples and Comparative Examples were measured.
The surface roughness of the surface protective sheet of Reference Example was also measured in the same manner (however, since the surface protective sheet of Reference Example does not have a smooth region, only the surface roughness of the uneven region was measured).

[Stylus of surface roughness detector]
Trade name ET1480 manufactured by Kosaka Laboratory (tip curvature radius: 0.5 μm, material: diamond)
[Measurement conditions of surface roughness measuring instrument]
・Reference length (cutoff value λc of roughness curve): 0.8 mm
・ Evaluation length (reference length (cutoff value λc) × 5): 4.0 mm
・Feeding speed of stylus: 0.1mm/s
・ Spare length: (cutoff value λc) × 1
・Vertical magnification: 10000 times ・Horizontal magnification: 100 times ・Filter characteristics: Gauss ・Leveling: None ・λs filter: None ・Sampling mode: c=1500

1-3. Clarity of transmission image For each of the optical comb widths of 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm and 2.0 mm, in accordance with JIS K7374:2007, the area of the resin sheet having an uneven area Transmission image sharpness was measured and the sum of _C0.125 , _C0.25 , _C0.5 , _C1.0 and _C2.0 was calculated. As a measuring device, an image clarity measuring device (trade name: ICM-1T) manufactured by Suga Test Instruments Co., Ltd. was used. The same measurement was performed for the surface protective sheet of Reference Example.

1-4. Antiglare A sample was prepared by bonding a black plate to the adherend side (transparent acrylic plate side) of the resin sheet and to the transparent base material side of the surface protection sheet of Reference Example via a transparent adhesive. The sample was placed on a horizontal surface, a fluorescent lamp was placed 1.5 m above the sample, and the illuminance above the sample was observed from various angles in an environment of 800 to 1200 Lx, and evaluated according to the following criteria.
AA: The image of the fluorescent lamp cannot be recognized in the uneven area from any angle.
A: The image of the fluorescent lamp is reflected in the uneven area, but the outline of the fluorescent lamp is blurred and the border of the outline cannot be recognized.
C: The image of the fluorescent lamp is reflected like a mirror on the uneven area, and the contour of the fluorescent lamp (border of the contour) can be clearly recognized.

1-5. Glitter A resin sheet or a surface protection sheet of a reference example is placed on a liquid crystal display device (Apple Inc. product name iPad (registered trademark) Air, resolution: 264 ppi), and the screen of the liquid crystal display device is displayed in green. It was visually evaluated whether it was conspicuous or not. The evaluation environment was a bright room environment (environment where the illuminance on the resin sheet was 800 to 1200 Lx when the liquid crystal image display device was turned off).
Evaluations were made by 20 subjects, with 2 points indicating no glare, 1 point indicating neither, and 0 points indicating strong glare, and the average score was calculated and evaluated according to the following criteria.
A: average score of 1.5 or more B: average score of more than 1.0 and less than 1.5 C: average score of more than 0.5 and 1.0 or less D: average score of 0.5 or less

1-6. Image clarity A resin sheet or a surface protective sheet of Reference Example was placed on a liquid crystal display device (trade name iPad (registered trademark) Air manufactured by Apple Inc., resolution: 264 ppi), and a still image was displayed on the screen of the liquid crystal display device. , and visually evaluated whether or not the contour of the image was clearly visible. The evaluation environment was a bright room environment (environment where the illuminance on the resin sheet was 800 to 1200 Lx when the liquid crystal image display device was turned off). In this evaluation, the distance from the light emitting surface of the display element to the surface of the resin sheet on the side provided with the concave-convex region was a little over 2 mm.
2 points were given when the contours of the image were clearly visible, 1 point was given when neither could be said, and 0 points were given when the contours of the image were blurred. Evaluation was made according to the following criteria.
A: average score of 1.5 or more B: average score of more than 1.0 and less than 1.5 C: average score of more than 0.5 and 1.0 or less D: average score of 0.5 or less

2. Preparation of plate [Plate 1]
A cylinder having a metal layer made of hard copper with a thickness of 200 μm on its surface was prepared. Next, areas other than the blasted portion were masked. Then, while rotating the cylinder, the surface of the non-masked portion of the cylinder is repeatedly sandblasted under the following conditions, resulting in a plate 1 having an uneven area A1 in the center and a smooth area A2 in the periphery. was made.
[Sandblasting conditions]
・Cylinder diameter: 300mm
・Abrasive particles: spherical glass beads with an average particle diameter of 20 μm ・Diameter of injection nozzle: 9 mm
・Angle of injection nozzle with respect to workpiece: vertical ・Injection pressure: 0.40 MPa
・Pump frequency: 90Hz
・Distance between injection nozzle and workpiece: 100mm

[Versions 2-4]
Plates 2 to 4 were produced in the same manner as Plate 1, except that the average particle size of the abrasive particles, the injection pressure, and the distance between the injection nozzle and the workpiece were changed to the sandblasting conditions shown in Table 1.

3. Preparation of release sheet [Release sheet 1]
A coating solution for forming an uneven layer having the following formulation was coated on the easy-adhesion-treated surface of a 50 μm-thick polyethylene terephthalate film (support) and dried to form an uncured coating film.
<Coating liquid for forming uneven layer>
・Urethane acrylate 60 parts ・Silicone leveling agent 0.5 parts ・Methyl ethyl ketone 40 parts

Next, using the mold 1 prepared in "2" above, an uncured coating film is shaped, and at the same time, ionizing radiation is irradiated from the polyethylene terephthalate film side to cure the shaped coating film, resulting in a polyethylene terephthalate film. An uneven layer having a thickness of 5.0 μm was formed thereon.

Next, a release layer-forming coating liquid having the following formulation was applied to the entire surface of the uneven layer, dried, and cured to form a release layer, whereby a release sheet 1 was obtained. The release sheet 1 and release sheets 1 to 6, which will be described later, had an uneven area A1' in the central portion and a smooth area A2' in the peripheral portion.
<Coating liquid for forming release layer>
・70 parts of acrylic polyol ・25 parts of isocyanate ・161 parts of ethyl acetate ・56 parts of methyl isobutyl ketone

[Release sheets 2 to 6]
Release sheets 2 to 6 were obtained in the same manner as for release sheet 1, except that the coating amounts of the plate and release layer were changed to the values shown in Table 1.
The approximate thickness of the release layer is obtained by multiplying the coating amount (g/m ² ) of the release layer by 1.4. For example, the thickness of the release sheet 1 is about 5.6 μm.

4. Preparation of transfer sheet and resin sheet [Example 1]
On the release layer of the release sheet 1 prepared in "3" above, a coating solution for forming a resin layer having the following formulation is applied so that the coating amount after drying is 6.5 g/m ² (6.0 μm). After forming a coating film, the resin layer was semi-cured by irradiation with a light source under the conditions of an H bulb, a conveying speed of 20 m/min, and an output of 40% using a fusion UV lamp system. When the integrated amount of light at this time was measured with an illuminometer (trade name: UVPF-A1) manufactured by Eye Graphics, it was 15 mJ/m ² .
<Coating liquid for resin layer formation>
- Urethane acrylate UV curable resin composition 100 parts (solid content 35% by mass, toluene/ethyl acetate mixed solvent)

Next, a coating solution for forming an anchor layer having the following formulation was coated on the resin layer so that the coating amount after drying was 3.0 g/m ² , dried to form a coating film, and then aged at 40°C for 72 hours. and cured to form an anchor layer with a thickness of 2 μm.
<Coating liquid for forming anchor layer>
・ 100 parts of acrylic polyol (solid content 25% by mass)
(toluene/ethyl acetate/methyl ethyl ketone mixed solvent)
- 10 parts of xamethylene diisocyanate (solid content 75% by mass, solvent: ethyl acetate)

Next, a coating liquid for forming an adhesive layer having the following formulation was applied onto the anchor layer so that the coating amount after drying was 2.5 g/m ² to form a coating film. The coating film was dried to form an adhesive layer having a thickness of 2 μm, and a transfer sheet of Example 1 was obtained. The refractive index of the adhesive layer was 1.49.
<Coating solution for adhesive layer>
・ 100 parts of acrylic resin (solid content 20%)
(ethyl acetate/n-propyl acetate/methyl ethyl ketone mixed solvent)
・40 parts of methyl ethyl ketone

Next, the transfer sheet is superimposed on a transparent acrylic sheet having a thickness of 2 mm, which is the adherend, so that the surface of the adhesive layer faces the adherend, and the transfer sheet is heat-pressed from the support side to obtain the adherend. and the transfer sheet were adhered and laminated. Next, after separating (peeling) the release sheet of the transfer sheet from the laminate, ultraviolet irradiation (in the air, H bulb, 800 mJ/cm ² ) was performed to completely cure the resin layer, and the resin sheet of Example 1 was obtained. Obtained.

[Examples 2-4], "Comparative Examples 1-2"
Resin sheets of Examples 2 to 4 and Comparative Examples 1 and 2 were obtained in the same manner as in Example 1, except that the release sheet was changed to that shown in Table 2.

[Reference Examples 1 and 2]
A surface protective sheet for a commercially available image display device was prepared. The surface protective sheets of Reference Examples 1 and 2 have an uneven layer containing a binder resin and particles on a transparent substrate.

As is clear from the results in Table 2, it can be confirmed that the resin sheets of Examples can suppress glare and impart antiglare properties while suppressing deterioration in image sharpness. In the evaluation of 1-6 above, no iridescent unevenness was observed in the resin sheets of Examples.

10: resin layer 20: anchor coat layer 30: adhesive layer 50: transparent substrate 70: release sheet 71: support 72: uneven layer 73: release layer 100: transfer layer 200: adherend 300: transfer sheet 1000: resin sheet

Claims (11)

A resin sheet having an uneven area on one surface,
The internal haze of the portion having the uneven region is 3.0% or less,
The arithmetic mean roughness of JIS B0601: 1994 when the cutoff value λc of the uneven region is 0.8 mm is Ra1, and the unevenness of JIS B0601: 1994 when the cutoff value λc of the uneven region is 0.8 mm Sm1 is the average interval between the uneven regions, and Rz1 is the ten-point average roughness of JIS B0601: 1994 when the cutoff value λc of the uneven region is 0.8 mm . ) , a resin sheet that satisfies (2) and (4) .
Ra1 [μm] × Sm1 [μm] ≤ 5.00 (1)
0.050 [μm]≦Ra1 (2)
3.0≦Rz1/Ra1≦10.0 (4) 2. The resin sheet according to claim 1, wherein the internal haze of the portion having the uneven region is 0%. 3. The resin sheet according to claim 1, wherein θa1 is 0.50 degrees or more when the average inclination angle of the uneven region is defined as θa1. The resin sheet according to claim 3, wherein θa1 is 1.603 degrees or more. The resin sheet according to any one of claims 1 to 4, wherein Ra1, Sm1 and θa1 satisfy the following formula (3).
1.30×10 ^-3 ≦Ra1 [μm]/Sm1 [μm]/θa1 (degrees) (3) The transmission image definition of the portion having the uneven region was measured according to JIS K7374:2007 for optical comb widths of 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm and 2.0 mm. , C _0.125 is the transmitted image sharpness with an optical comb width of 0.125 mm, C _0.25 is the transmitted image sharpness with an optical comb width of 0.25 mm, and C is the transmitted image sharpness with an optical comb width of 0.5 mm. C _0.125 , C 0.25 , C 0.5 , C _{0.5 ,} C 0.125 , C _0.25 , C 0.5 , C _0.5 , C _{1.0 when the width of the optical comb is 1.0 mm, and C 2.0 when} the width of the optical comb is 2.0 mm. The resin sheet according to any one of claims 1 to 5 , wherein the sum of C _1.0 and C _2.0 is 300% or more. The resin sheet according to any one of claims 1 to 6 , wherein said one surface is provided with a smooth area adjacent to said uneven area. A front panel for an image display device using the resin sheet according to any one of claims 1 to 7 . A transfer sheet having a transfer layer on a release sheet, wherein the transfer layer has an uneven area on a surface thereof in contact with the release sheet, and satisfies Condition 1 below.
<Condition 1>
After bonding the surface of the transfer sheet on the transfer layer side to a transparent plate having an internal haze of 0%, the release sheet is peeled off, and a sample A is prepared by transferring the transfer layer onto the transparent plate. . The arithmetic mean roughness of JIS B0601: 1994 when the internal haze of the portion having the uneven region of the sample A is 3.0% or less and the cutoff value λc of the uneven region of the sample A is 0.8 mm Ra1, the average spacing of the unevenness of JIS B0601: 1994 when the cutoff value λc of the uneven region of sample A is 0.8 mm, Sm1 , and the JIS when the cutoff value λc of the uneven region is 0.8mm When the ten-point average roughness of B0601:1994 is defined as Rz1 , Ra1 , Sm1 and Rz1 satisfy the following formulas (1) , (2) and (4) .
Ra1 [μm] × Sm1 [μm] ≤ 5.00 (1)
0.050 [μm]≦Ra1 (2)
3.0≦Rz1/Ra1≦10.0 (4) An image display device having a display element and a front panel disposed on the light emitting surface side of the display element, wherein the resin sheet according to any one of claims 1 to 7 is used as the front panel. An image display device arranged so that the surface on the side having the concave-convex region faces the opposite side to the display element. 11. The image display device according to claim 10 , wherein the distance from the light exit surface of the display element to the surface of the resin sheet on the side provided with the uneven region is 2.0 mm or more.

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