TWI702414B - Optical film and display device with touch panel - Google Patents

Abstract

The present invention provides an optical film that can suppress reflections or Newton's rings and suppress glare, and has low total haze and internal haze, and a touch panel with a touch panel that can sufficiently suppress the generation of watermark and glare Display device.

The optical film of the present invention has the following structure: an optical layer having a concave and convex shape on the surface is laminated on a translucent substrate, and is characterized in that the total haze value is 0% or more and 5% or less, and the internal haze value is 0% Above and less than 5%, set the penetration image clarity measured by an optical comb with a width of 0.125mm to C(0.125), and set the penetration image measured by an optical comb with a width of 0.25mm as clear When the degree is C(0.25), the following equations (1) and (2) are satisfied.

C(0.25)-C(0.125)≧2% (1)

C(0.125)≦64% (2)

Description

Optical film and display device with touch panel

The invention relates to an optical film and a display device with a touch panel.

In liquid crystal display (LCD), cathode ray tube display device (CRT), plasma display (PDP), electroluminescence display (ELD), field emission display (FED) and other image display devices, the image display surface is usually To suppress the reflection of the observer and the background of the observer, it is provided with an anti-glare film with uneven surface or an anti-reflective film with an anti-reflection layer on the outermost surface.

The anti-glare film scatters external light on the concave-convex surface of the anti-glare layer to suppress the reflection of the observer and the background of the observer. The anti-glare film mainly includes a light-transmitting substrate and an anti-glare layer with uneven surface provided on the light-transmitting substrate.

The anti-glare layer usually contains a binder resin and fine particles that are present in the binder resin and used to form an uneven surface.

However, when such an anti-glare film is disposed on the surface of an image display device, the uneven surface of the anti-glare layer may cause image light to scatter, which may cause so-called glare. In response to this problem, the industry proposes to increase the internal haze of the anti-glare film to suppress glare (for example, refer to Patent Document 1).

Moreover, in recent years, continuous development has been called 4K2K (horizontal pixels 3840× The number of vertical pixels (2160) is an ultra-high-definition image display device with a number of horizontal pixels above 3000.

In this type of ultra-high-definition image display device, similar to the above-mentioned image display device, an anti-glare film is provided on the image display surface, but for ultra-high-definition image display devices, the requirements are higher than before Brightness or light transmittance.

Here, if the total haze or internal haze of the anti-glare film is increased, it will cause a decrease in brightness or light transmittance. Therefore, for ultra-high-definition image display devices, it is impossible to use the method to increase the internal haze of the anti-glare film. Means as a means for suppressing glare as described above. In addition, if the internal haze of the anti-glare film is increased, the image light may diffuse in the anti-glare film, and part of the image light may become stray light. As a result, the contrast of the dark room may decrease and the image may be blurred. Therefore, currently, as a film incorporated into an ultra-high-definition image display device, a film that can suppress glare and has a low total haze and internal haze is desired.

In addition, in recent years, small mobile devices equipped with touch panels such as smart phones or tablet terminals have rapidly spread. In such small mobile devices, the image display device has a problem of glare due to the ultra-high definition of the displayed image. It becomes more significant, but on the other hand, higher brightness or light transmittance is required than before.

Previously, there are known display devices with touch panels that are equipped with touch panels on display panels such as liquid crystal displays. In the above-mentioned small mobile devices, a large number of image display devices equipped with touch panels are also used The display device with touch panel. For such a display device with a touch panel, information can be directly input by touching the image display surface with a finger or the like.

When fixing the touch panel on the display panel, in most cases, the display panel and the touch panel are separated from each other. That is, in many cases, the display panel and the touch panel are arranged with an air layer (air gap) interposed therebetween (for example, refer to Patent Document 2).

The image display surface of a display device with a touch panel is not only touched with fingers, but also pressed strongly with fingers. When the image display surface is strongly pressed, there is a problem that the distance between the touch panel and the display panel becomes narrower (the thickness of the air layer becomes thinner) due to the deformation of the touch panel. The light reflected on the surface of the display panel side interferes with the light reflected on the surface of the touch panel side of the display panel, resulting in Newton's rings, which reduces the visibility of the screen.

In addition, in recent years, the thinner and larger area of display devices with touch panels have been continuously promoted. As the display device with touch panel becomes thinner, the distance between the touch panel and the display panel becomes narrower, and as the display device with touch panel becomes larger, the touch panel becomes It is easy to deform. Therefore, the problem of Newton's ring becomes more significant.

Furthermore, the Newton ring generated with the deformation of the touch panel is also specifically called a watermark in the following.

For this kind of watermark problem, for example, Patent Document 3 proposes to fill the gap between the touch panel and the liquid crystal display panel with a resin material and set it as a resin layer, thereby eliminating the reflection at the interface between the touch panel and the liquid crystal display panel.

However, when a resin material is filled to manufacture a final product, even if defects are found in the touch panel after the final product is manufactured, it is impossible to replace only the touch panel. In addition, it is difficult to completely fill the gap between the touch panel and the liquid crystal display panel with the resin material, and if it becomes a state containing bubbles, it will cause display image defects.

Here, for a display device in which the display panel and the touch panel are separated from each other, there is known a method of providing a concave-convex surface on the surface of the display panel to diffuse incident light on the concave-convex surface to suppress the generation of Newton's rings (for example, Refer to Patent Document 4).

However, in such a display device with a touch panel in which a concave-convex surface is provided on the surface of the display panel, the concave-convex surface may cause image light to scatter, resulting in so-called glare.

For this kind of glare problem, similar to the above-mentioned film incorporated into the ultra-high-definition image display device, it is impossible to adopt a method to increase the internal haze of the display panel.

In addition, for this kind of glare problem, for example, the following direction has so far been studied: the method of making the concave-convex interval (Sm) of the concave-convex surface less than half of the pixel size, etc., reduces the concave-convex interval. However, for ultra-high-definition image display devices, there are cases in which glare cannot be sufficiently suppressed by the conventional method of reducing the interval between unevenness.

[Patent Document 1] JP 2010-102186 A

[Patent Document 2] JP 2010-15412 A

[Patent Document 3] JP 2004-077887 A

[Patent Document 4] JP 2002-189565 A

In view of the above-mentioned current situation, the present invention aims to provide an optical film that can suppress reflections or Newton's rings and glare, and has low total haze and internal haze, and a touch panel with sufficient suppression of watermark and glare The display device.

The present invention is an optical film, which has the following structure: an optical layer having a concave-convex shape on the surface is laminated on a translucent substrate, and is characterized in that the total haze value is 0% or more and 5% or less, and the internal haze value If it is 0% or more and 5% or less, the clearness of the penetration image measured by a comb with a width of 0.125mm is set to C(0.125), and the measurement with a comb with a width of 0.25mm is When the clarity of the through image is set to C (0.25), the following equations (1) and (2) are satisfied.

C(0.25)-C(0.125)≧2% (1)

C(0.125)≦64% (2)

In addition, another aspect of the present invention is an optical film having the following structure: an optical layer having an uneven surface is laminated on a translucent substrate, and is characterized in that the surface of the optical film is half of the surface height distribution The value width is 200 nm or more, and the average curvature of the surface unevenness is 0.30 mm ^-1 or less.

In the optical film of the present invention, it is preferable that the total haze value of the optical film is 0% or more and 5% or less, and the internal haze value of the optical film is 0% or more and 5% or less.

Furthermore, in the optical film of the present invention, it is preferable that the total haze value of the optical film is 0% or more and 1% or less, and the internal haze value of the optical film is substantially 0%.

Furthermore, in the optical film of the present invention, it is preferable that the optical layer contains a binder resin and fine particles.

Furthermore, it is preferable that the above-mentioned fine particles are inorganic oxide fine particles.

It is preferable that the average primary particle diameter of the inorganic oxide microparticles is 1 nm or more and 100 nm or less, and it is also preferable that the inorganic oxide microparticles are inorganic oxide microparticles whose surfaces are hydrophobized.

In addition, the present invention is a display device with a touch panel, which has a configuration in which the optical film of the present invention and the touch panel are arranged oppositely, and the optical film of the present invention and the above touch panel are mutually provided The state of the gap is arranged so that the optical layer of the optical film faces the touch panel.

Hereinafter, the present invention will be described in detail.

In addition, in this specification, the so-called "resin" is a concept that also includes monomers, oligomers, etc., unless it is specifically mentioned.

In addition, in the following, the matters common to the optical film of the present invention and the optical film of another aspect of the present invention will be described only as the optical film of the present invention.

The inventors of the present invention conducted diligent studies and found that by setting the surface of the optical film into a specific concave-convex shape, the generation of glare can be highly suppressed regardless of the internal haze of the optical film, and further, by combining the optical film with The configuration of the touch panel facing the configuration, even if a gap is provided between the optical film and the touch panel, the generation of watermark can be suppressed to a high degree, and a good display image can be obtained, thereby completing the present invention.

Furthermore, since the optical film of the present invention can also suppress the generation of Newton's rings such as watermarks to a high degree, it can also be used as an optical layer disposed opposite to the touch panel.

Fig. 1 is a cross-sectional view schematically showing the optical film of the present invention.

In the optical film 11 of this invention, it has the structure which laminated|stacked the translucent base material 12 and the optical layer 13 which has the uneven shape on the surface.

The total haze value of the optical film 11 of the present invention is 0% or more and 5% or less, and the internal haze value is 0% or more and 5% or less.

The total haze value and the internal haze value are measured as the entire optical film.

Furthermore, the above-mentioned total haze value and internal haze value can be measured using a haze meter (HM-150, manufactured by Murakami Color Technology Research Institute) by a method based on JIS K7136. Specifically, a haze meter is used to measure the total haze value of the optical film in accordance with JIS K7136. Thereafter, a triacetyl cellulose substrate (manufactured by Fuji Film Co., TD60UL) was attached to the surface of the optical film via a transparent optical adhesive layer. Thereby, the uneven shape of the surface of the optical film is flattened, and the surface of the optical film becomes flat. Then, in this state, using a haze meter (HM-150, manufactured by Murakami Color Research Institute), the haze value was measured in accordance with JIS K7136, thereby obtaining the internal haze value. The internal haze does not consider the unevenness of the surface of the optical film.

The total haze value of the optical film 11 of the present invention is preferably 1% or less, more preferably 0.3% or more and 0.5% or less. The internal haze value is preferably substantially 0%. Here, the so-called "internal haze value is substantially 0%" means the following: it is not limited to the case where the internal haze value is completely 0%, and includes even when the internal haze value exceeds 0%. Within the range of measurement error and the internal haze value can be roughly regarded as the range of 0% (for example, the internal haze value below 0.3%).

When the total haze value of the optical film 11 is 0% or more and 5% or less, and the internal haze value is 0% or more and 5% or less, the surface haze value of the optical film 11 is 0% or more and 5% or less . The surface haze value of the optical film 11 is preferably 0% or more and 1% or less, more preferably 0% or more and 0.3% or less. The surface haze value is caused only by the unevenness of the surface of the optical film 11. By subtracting the internal haze value from the total haze value, the surface haze caused only by the unevenness of the surface of the optical film 11 can be obtained Degree value.

In the optical film 11 of the present invention, when the transmission image clarity of the optical film 11 measured using an optical comb with a width of 0.125mm is set to C(0.125), the optical When the clearness of the penetration image of the film 11 is set to C (0.25), the following equations (1) and (2) are satisfied.

C(0.25)-C(0.125)≧2% (1)

C(0.125)≦64% (2)

Furthermore, the so-called "transmission image clarity" mentioned above can be measured by the penetration image clarity measurement device based on the image clarity of JIS K7374. set. As such a measuring device, for example, the image clarity measuring device ICM-1T manufactured by SUGA Test Instruments, etc. can be cited.

In addition, as shown in FIG. 2, the transmission image clarity measuring device 100 includes a light source 101, a slit 102, a lens 103, a lens 104, an optical comb 105, and a light receiver 106. The lens 103 causes the light source 101 to emit light. And the light passing through the slit 102 becomes parallel light, the parallel light is irradiated to the translucent substrate 12 side of the optical film 11, and the light transmitted from the concave-convex shape 14 of the optical layer 13 of the optical film 11 by the lens 104 Those who gather and receive the light passing through the optical comb 105 by the light receiver 106, based on the amount of light received by the light receiver 106, calculate the transmission image definition C according to the following formula (3).

C(n)={(M-m)/(M+m)}×100(%) (3)

Furthermore, in formula (3), C(n) is the image clarity (%) when the width of the comb is n (mm), and M is the highest light intensity when the width of the comb is n (mm), m It is the minimum amount of light when the width of the comb is n (mm).

The optical comb 105 can move along the length of the optical comb 105 and has a light-shielding part and a penetrating part. The width ratio of the light-shielding part and the penetrating part of the optical comb 105 becomes 1:1. Here, in JIS K7374, as the optical comb, five types of optical combs with widths of 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm are specified.

In the present invention, the optical film must satisfy the above formula (1) and formula (2). The reason is as follows.

That is, first, in the optical film, in order to obtain anti-reflective properties or anti-watermarking properties such as Newton's rings, a concave-convex shape is formed on the surface of the optical layer. After research, the inventors found that by satisfying the above formula (2) The necessary condition is to set the value of C(0.125) to 64% or less, which can effectively prevent reflection or watermarking.

Furthermore, the anti-reflective property in the present invention refers to those who do not mind the degree of reflection of the observer (observer) and the observer’s background, for example, it means the following: although the observer is found, the outline is not A clear and fuzzy state, and although objects in the background of the observer are also found, their outlines or boundaries become unclear. In this way, only when the outline of the observer is blurred, it becomes a state where the observer does not mind being reflected.

On the other hand, there are cases where the concave portion or convex portion of the concave-convex shape condenses and diffuses light to act like a lens (lens effect). It is also believed that if such a lens effect occurs, the transmitted light from the "black matrix that separates the pixels of the liquid crystal display" or "pixels" is randomly enhanced, thereby generating glare.

Therefore, the inventors of the present invention conducted further studies, and as a result, it was found that the diffusion of light caused by the uneven shape formed on the surface of the optical layer of the optical film is made to diffuse at a smaller angle, specifically, by Satisfying the requirements of the above formula (1), that is, setting the value of C(0.25)-C(0.125) to 2% or more can suppress the generation of glare. The reason for this is considered as follows.

That is, the smaller the light comb is, the smaller the light comb is, the more it is affected by the diffusion of the minute angle and the value decreases. Therefore, it can be said that the smaller the value when a smaller comb is used and the larger the value when using a larger comb, the less wide-angle spread.

Therefore, it is believed that by making the second largest comb, that is, C(0.25) more than 2% larger than the value of C(0.125), the diffusion at a small angle can be achieved. Furthermore, it is believed that by setting the diffusion at a small angle, The lens effect becomes extremely small, so it is extremely effective to prevent glare.

In terms of the above, it is considered that the optical film must satisfy the above formula (1) and formula (2).

Furthermore, usually practitioners predict that from the viewpoint of suppressing glare, the difference between the value of C(0.25) and the value of C(0.125) should be small. If the difference is large, the glare will be worse. This situation can also be borrowed Confirmed by Japanese Patent Publication No. 2010-269504. In the publication, it is stated that from the viewpoint of suppressing glare, the ratio of the penetration image definition using a 0.125mm optical comb to the penetration image definition using a 2.0mm optical comb is set to 0.70 or more , And the ratio is preferably 0.80 or more and 0.93 or less. That is, in this publication, although the 0.25mm optical comb is not used, it is stated that the ratio is above 0.80 compared to 0.70 or more. Therefore, the following direction is pointed out: the penetration of the 0.125mm optical comb It is advisable that the difference between the image definition and the through image definition of a 2.0mm comb is smaller. In contrast to this, contrary to the prediction, in the present invention, in order to suppress glare, the difference between the value of C(0.25) and the value of C(0.125) is set to 2% or more.

Therefore, the optical film satisfying the above formula (1) and formula (2) can be said to be beyond the predictable range according to the technical level of the previously known optical film.

Furthermore, in the specification of this case, when it is called an optical laminate, it also means an optical film.

FIG. 3 is a cross-sectional view schematically showing a display device with a touch panel using the optical film 11 of the present invention.

As shown in FIG. 3, the display device 30 with a touch panel of the present invention has an optical film 31 and a touch panel 35 opposed to each other. The optical film 31 is laminated on one surface of a light-transmitting substrate 32 with uneven surfaces. Optical layer 33 of shape 34.

In the display device 30 with a touch panel of the present invention, the optical film 31 and the touch panel 35 are arranged opposite to each other such that the optical layer 33 (concave and convex shape 34) faces the touch panel 35 in a state with a gap between them.

Here, as the touch panel 35, a resistive film type touch panel, an electrostatic capacitance type touch panel, etc. can be cited. In the display device 30 with a touch panel of the present invention, any method can be used, of which the preferred It is an electrostatic capacitive touch panel.

In the display device 30 with a touch panel of the present invention, the total haze value of the optical film 31 is 0% or more and 5% or less, and the internal haze value is 0% or more and 5% or less.

The total haze value and the internal haze value are measured as the entire optical film.

In the display device with a touch panel of the present invention, the total haze value of the optical film 31 is preferably 1% or less, more preferably 0.3% or more and 0.5% or less.

The internal haze value is preferably substantially 0%.

Here, the so-called "internal haze value is substantially 0%" means the following: it is not limited to the case where the internal haze value is completely 0%, and includes even when the internal haze value exceeds 0%. Within the range of measurement error and the internal haze value can be roughly regarded as the range of 0% (for example, the internal haze value below 0.3%).

When the total haze value of the optical film 31 is 0% or more and 5% or less, and the internal haze value is 0% or more and 5% or less, the surface haze value of the optical film 31 is 0% or more and 5% or less .

The surface haze value of the optical film 31 is preferably 0% or more and 1% or less, more preferably 0% or more and 0.3% or less.

The surface haze value is caused only by the unevenness of the surface of the optical film 31. By subtracting the internal haze value from the total haze value, the surface haze caused only by the unevenness of the surface of the optical film 31 can be obtained. Degree value.

For the display device with touch panel of the present invention, when the penetration image clarity of the optical film 31 measured using a light comb with a width of 0.125mm is set to C(0.125), it will be measured with a light comb with a width of 0.25mm When the clarity of the transparent image of the optical film 31 is set to C(0.25), the following formulas (1) and (2) are satisfied.

C(0.25)-C(0.125)≧2% (1)

C(0.125)≦64% (2)

In the display device with a touch panel of the present invention, the difference between the value of C(0.25) and the value of C(0.125) is preferably 5% or more, more preferably 10% or more. In addition, the difference between the value of C(0.25) and the value of C(0.125) is preferably 30% or less.

The value of C(0.125) is preferably 60% or less, more preferably 50% or less. In addition, the value of C(0.125) is preferably 5% or more, more preferably 20% or more.

Furthermore, in another form of the optical film of the present invention, the half-value width of the surface height distribution of the surface of the optical film 11 shown in FIG. 1 is 200 nm or more.

Here, the reason why the half-value width of the surface height distribution of the surface of the optical film is set to 200 nm or more is that if it is in this range, the watermark cannot be observed by human eyes, that is, the watermark can be made invisible.

Various theories are considered as the reason. For example, the theories shown below can be cited.

4 is a schematic diagram showing how light incident into a display device with a touch panel using another form of the optical film 11 of the present invention is reflected.

As shown in FIG. 4, the light incident from the side of the touch panel 45 is reflected on the surface of the optical layer 43 (concave-convex shape 44) due to the light reflected on the interface between the optical layer 43 and the gap 46 and penetrating through the gap 46 Light generates interference, and the interference color of each position changes according to the thickness of each position of the gap 46 between the touch panel 45 and the surface (concave-convex shape 44) of the optical layer 43.

Furthermore, in Fig. 4, the interference occurs in the entire visible wavelength range. The interference color of the light (A) in the thickest part of the gap 46 is red, and the interference color of the light (C) in the thinnest part of the gap 46 It is blue, and the interference color of light (B) is yellow-green between light (A) and light (C). Moreover, if such a change of interference color occurs in a small area that humans cannot recognize, each interference The color is mixed, and the human eye cannot recognize the interference fringes (watermark).

That is, since the thickness change of the gap 46 corresponds to the height distribution of the uneven shape 44, it is sufficient that the height distribution is formed in an area that cannot be recognized by the human eye and is a distribution that sufficiently generates interference colors over the entire visible light wavelength.

Here, the difference between the optical distance between the interference color at the lower limit wavelength of the visible light wavelength and the interference color at the upper limit wavelength of the visible light wavelength is the largest when the optical distance becomes 1 wavelength. Since the visible light wavelength is in the range of 380nm~780nm, Therefore, the difference in optical distance at this time becomes 400nm (780nm-380nm).

Therefore, if the difference in optical distance is 400 nm or more, and the height distribution of the uneven shape 44 therebetween is as uniform as possible, interference colors can be sufficiently generated in the entire visible light wavelength.

In addition, since the above-mentioned optical distance is twice the thickness of the gap 46, the thickness of the gap 46 changes as long as it is 200 nm or more.

In other words, as long as the surface height of the optical layer 43 having the uneven shape 44 on the surface has a distribution as uniform as possible in the range of 200 nm or more.

Therefore, if the half-value width of the surface height distribution on the surface of the optical film 11 is 200 nm or more, the uneven shape 44 has a distribution that is as uniform as possible in the above-mentioned surface height range of 200 nm or more. The height distribution of "Interference Color" makes the watermark invisible.

In addition, at this time, in order to ensure the thickness variation of the gap 46, that is, the surface height of the optical layer 43 is distributed in a small area, it is only necessary to calculate the surface height distribution based on the surface profile after the large gaps are removed in advance.

That is, it is sufficient to use the surface profile of "using a long-wavelength cut filter".

From the viewpoint of making it unrecognizable by the human eye, the wavelength of the long-wavelength cut filter is preferably set to 800 μm.

Here, the half-value width of the surface height distribution is expressed as follows: According to the surface profile obtained with a contact surface roughness meter or a non-contact surface roughness meter (such as an interference microscope, a confocal microscope, an atomic force microscope, etc.), The half-value width of the bump distribution (half height position of the height of the peak position distribution) obtained by plotting the Histogram Plot with the horizontal axis as the bump height (unit: nm) and the vertical axis as the frequency (unit: Counts) The width of the distribution) (unit: nm).

The half-value width of the above-mentioned surface height distribution is preferably 220 nm or more, more preferably 250 nm or more.

Furthermore, the half-value width of the above-mentioned surface height distribution is preferably 500 nm or less.

If the half-value width of the surface height distribution exceeds 500 nm, the height of the surface unevenness is too large, and glare may deteriorate.

The half-value width of the surface height distribution is more preferably 400 nm or less, and still more preferably 300 nm or less.

In terms of simplicity, the above-mentioned surface profile is preferably measured using an interference microscope.

Examples of such interference microscopes include the "New View" series manufactured by Zygo Corporation.

The average curvature of the surface concavities and convexities of the surface of the optical film 11 of the present invention of the above-mentioned another aspect is 0.30 mm ^-1 or less.

Concave and convex shapes are formed on the surface of the optical layer for the purpose of preventing watermarks, etc. However, the concavities and convexities of the concave and convex shapes may function like lenses (lens effect).

It is also believed that if such a lens effect is generated, the transmitted light from the "black matrix that separates the pixels of the liquid crystal display" or "pixels" is randomly enhanced, thereby generating glare.

The inventors of the present invention conducted research and found that the greater the curvature of the concave-convex shape, the greater the lens effect and the easier it is to generate glare.

Therefore, by setting the average curvature of the surface unevenness of the optical film surface to 0.30 mm ^-1 or less, even if the uneven shape is formed, glare can be prevented extremely effectively.

The average curvature of the surface concavities and convexities is preferably 0.25 mm ^-1 or less, and more preferably 0.20 mm ^-1 or less.

Furthermore, the average curvature of the surface irregularities is preferably 0.05 mm ^-1 or more.

If the average curvature is less than 0.05mm ^-1 , the waterproof seal may be poor.

Here, the average curvature of the surface unevenness is obtained as follows.

Figure 5 is the surface profile of the above optical film. As shown in Figure 5, when A (x1, y1), B (x2, y2) and C (x3, y3) are given to the surface profile of the optical film, the curvature of point B can be It is calculated as the reciprocal of the radius of the circle passing through the 3 points of point A, point B, and point C, and expressed by the following formula.

A surface profile obtained in the same way as when calculating the above surface height distribution, in which, if the horizontal direction is set to the x direction, the height direction is set to the y direction, and the measurement interval in the horizontal direction is set to d, then x2-x1 =x3-x2=d, y1, y2, y3 are regarded as the height of each point, the above formula can be rewritten as follows.

By performing the calculations as described above for each point based on the surface profile, the curvature of each point is calculated, and the average curvature of the surface concavities and convexities can be calculated by averaging them.

At this time, since the extremely small unevenness does not contribute to the lens effect, it is preferably not included in the calculation of curvature. Therefore, it is better to use a short-wavelength cut filter to remove the extremely small unevenness when calculating the surface profile. Remove.

From this viewpoint, the wavelength of the short-wavelength cut filter is preferably set to 25 μm.

Furthermore, in general, practitioners predict that from the viewpoint of suppressing glare, the value of the average interval (Sm) of surface irregularities is better. If the value is larger, the glare will deteriorate (for example, refer to Japanese Patent Application Publication No. 2010-191412 Bulletin, etc.).

However, the smaller the average interval of the surface unevenness means the larger the average curvature. Therefore, the half-value width of the above-mentioned surface height distribution and the average curvature of the surface concavities and convexities meet the above-mentioned specific numerical value range of the optical film, according to the technical level of the previously known optical film, it can be said that it is beyond the predictable range.

In addition, in a display device with a touch panel using another form of the optical film of the present invention (hereinafter also referred to as another form of the display device with a touch panel of the present invention), another one shown in FIG. 3 The half-value width of the surface height distribution of the surface of the optical film 31 of the present invention is 200 nm or more.

Here, the half-value width of the surface height distribution is expressed as follows: According to the surface profile obtained with a contact surface roughness meter or a non-contact surface roughness meter (such as an interference microscope, a confocal microscope, an atomic force microscope, etc.), The half-value width of the uneven distribution obtained by plotting the histogram with the horizontal axis as the bump height (unit: nm) and the vertical axis as the frequency (unit: Counts) (the width of the distribution at the half-height position of the height of the peak position distribution) ) (Unit: nm).

In another aspect of the display device with a touch panel of the present invention, the half-value width of the above-mentioned surface height distribution is preferably 220 nm or more, more preferably 250 nm or more.

Furthermore, the half-value width of the above-mentioned surface height distribution is preferably 500 nm or less.

If the half-value width of the surface height distribution exceeds 500 nm, the height of the surface unevenness is too large, and glare may deteriorate.

The half-value width of the surface height distribution is more preferably 400 nm or less, and still more preferably 300 nm or less.

In terms of simplicity, the above-mentioned surface profile is preferably measured using an interference microscope.

Examples of such interference microscopes include the "New View" series manufactured by Zygo Corporation.

In another aspect of the display device with a touch panel of the present invention, the average curvature of the surface unevenness of the optical film surface is 0.30 mm ^-1 or less.

The average curvature of the surface irregularities is preferably 0.25 mm ^-1 or less, and more preferably 0.20 mm ^-1 or less.

Furthermore, the average curvature of the surface irregularities is preferably 0.05 mm ^-1 or more.

If the average curvature is less than 0.05mm ^-1 , the waterproof seal may be poor.

Furthermore, in general, practitioners predict that from the viewpoint of suppressing glare, the value of the average interval (Sm) of surface irregularities is better. If the value is larger, the glare will deteriorate (for example, refer to Japanese Patent Application Publication No. 2010-191412 Bulletin, etc.).

However, the smaller the average interval of the surface unevenness means the larger the average curvature. Therefore, the half-value width of the above-mentioned surface height distribution and the average curvature of the surface concavities and convexities meet the above-mentioned specific numerical value range of the optical film, according to the technical level of the previously known optical film, it can be said that it is beyond the predictable range.

The optical film of the present invention is laminated on a light-transmitting substrate with an optical layer having uneven shapes on the surface.

The above-mentioned translucent substrate is not particularly limited as long as it has translucency, and examples include cellulose acylate substrates, cycloolefin polymer substrates, polycarbonate substrates, Acrylic polymer substrate, polyester substrate, or glass substrate, etc.

As said acylated cellulose base material, a triacetate cellulose base material, a cellulose diacetate base material, etc. are mentioned, for example.

Moreover, as the said cycloolefin polymer base material, the base material etc. which consist of polymers, such as a norbornene-type monomer and a monocyclic cycloolefin monomer, etc. are mentioned, for example.

In addition, examples of the aforementioned polycarbonate substrate include aromatic polycarbonate substrates based on bisphenols (bisphenol A, etc.), and diethylene glycol bisallyl carbonate (diethylene glycol bisallyl carbonate). ) And other aliphatic polycarbonate substrates.

In addition, examples of the above-mentioned acrylate-based polymer substrates include polymethyl (meth)acrylate substrates, polyethyl (meth)acrylate substrates, and methyl (meth)acrylate-(meth)acrylate substrates. Butyl acrylate copolymer substrate, etc. In addition, in this specification, (meth)acrylic acid means acrylic acid or methacrylic acid.

Examples of the polyester substrate include at least one of polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate. As a base material for constituents, etc.

Examples of the glass substrate include glass substrates such as soda lime silica glass, borosilicate glass, and alkali-free glass.

Among them, in terms of excellent retardation and easy adhesion to the polarizing element, the acylated cellulose substrate is preferred, and among the acylated cellulose substrates, the triacetyl cellulose substrate is preferred. (TAC substrate). The triacetyl cellulose substrate is a transparent substrate with an average light transmittance above 50% in the visible light range of 380~780nm. The average light transmittance of the triacetyl cellulose substrate is preferably 70% or more, and more preferably 85% or more.

Furthermore, the triacetyl cellulose substrate may also be the following: in addition to the pure triacetyl cellulose, it becomes cellulose acetate propionate (cellulose acetate propionate), cellulose acetate butyrate (cellulose acetate butyrate), etc. ) Generally, fatty acids that form cellulose and esters are used in combination with ingredients other than acetic acid. In addition, other cellulose lower fatty acid esters such as diacetyl cellulose, or various additives such as plasticizers, ultraviolet absorbers, and slip agents may be added to the triacetyl cellulose as necessary.

In terms of excellent retardation and heat resistance, a cycloolefin polymer substrate is preferred, and in terms of mechanical properties and heat resistance, a polyester substrate is preferred.

The thickness of the translucent substrate is not particularly limited, and it can be set to 5 μm or more and 1000 μm or less. From the viewpoint of handling properties, the lower limit of the thickness of the translucent substrate is preferably 15 μm or more, more preferably Above 25μm. From the viewpoint of thinning, the upper limit of the thickness of the translucent substrate is preferably 80 μm or less.

The optical film of the present invention preferably has a mixed region at the interface between the translucent substrate and the optical layer, and the mixed region is the translucent substrate and photopolymerization containing a weight average molecular weight of 1000 or less Monomers are obtained by mixing resins as monomer units. By having the above-mentioned mixed region, it is possible to suppress interference fringes caused by the reflection at the interface between the above-mentioned translucent base material and the optical layer.

The above-mentioned photopolymerizable single system is the same as "the photopolymerizable monomer whose weight average molecular weight of the following binder resin contained in the optical layer as a monomer unit is 1000 or less".

The thickness of the aforementioned mixed region is preferably 0.01 μm or more and 1 μm or less. The optical film and the display device with a touch panel of the present invention can sufficiently suppress the generation of interference fringes by the following concave-convex surface of the optical layer, so even in the above-mentioned mixed presence area When the thickness is thinner as mentioned above, interference fringes can also be suppressed. Furthermore, the previously known anti-reflection film also suppresses interference fringes by forming the same mixed area as the above-mentioned mixed area, but the thickness of the mixed area formed in the previously known anti-reflection film is 3 μm or more. Compared with the mixed area formed in the conventional anti-reflection film, the thickness of the mixed area formed in the present invention can be said to be thin enough.

In addition, by forming the above-mentioned mixed region, the adhesion between the translucent base material and the optical layer can be further improved.

Furthermore, as described above, since the occurrence of interference fringes can be sufficiently suppressed by the uneven surface of the optical layer, it is not necessary to form such a mixed region in the optical film. Since the occurrence of interference fringes can be suppressed even when the mixed area is not formed in this way, it is difficult to form a mixed area with a substrate such as an acrylic substrate, a cycloolefin polymer substrate, or a polyester substrate. It can also be used as a translucent substrate.

Examples of the above-mentioned optical layer include layers that exhibit functions such as anti-reflection, hard coating, anti-glare, antistatic, or antifouling properties.

When the above-mentioned optical layer is a layer that exhibits hard coating properties in addition to anti-reflective properties, the optical layer preferably has a pencil hardness test (4.9N load) specified in JIS K5600-5-4 (1999) Hardness above "H".

The surface of the above-mentioned optical layer becomes an uneven surface formed with uneven shapes as described above. In addition, the above-mentioned "surface of the optical layer" means that the surface of the optical layer on the side of the translucent substrate (the back surface of the optical layer) is the opposite side.

In addition, as long as the internal haze value is within the range of 0% or more and 5% or less, the internal haze value will not affect the clarity of the through image, so the clarity of the through image is affected by the optical film The influence of the uneven shape of the surface. On the other hand, in the present invention, the surface of the optical film becomes the uneven surface of the optical layer. Therefore, in the present invention, whether the clarity of the transparent image of the optical film satisfies the above-mentioned formulas (1) and (2) is determined by the concave-convex shape of the concave-convex surface of the optical layer. In addition, below, the uneven surface of the optical layer in which the optical film satisfies the above formulas (1) and (2) is referred to as "special uneven surface".

Also, as with the above reasons, as long as the internal haze value is within the range of 0% or more and 5% or less, the internal haze of the optical film will not affect the generation of glare. Therefore, the internal haze is within the above range. In the case of haze, the uneven shape on the surface of the optical film will affect the glare. Hereinafter, the uneven surface of the optical film that satisfies the above-mentioned requirements in the present invention is also referred to as "special uneven surface".

The above-mentioned special uneven surface can be formed by appropriately adjusting the number of the unevenness, the size of the unevenness, or the inclination angle of the unevenness, etc. As a method of adjusting these, for example, the use of a photopolymerizable resin containing a hardened adhesive resin A method of forming an uneven surface with a compound and fine particle composition for an optical layer.

In the above-mentioned method of forming an uneven surface, when the photopolymerizable compound is polymerized (crosslinked) to become a binder resin, the photopolymerizable compound shrinks as a whole due to curing and shrinkage of the part where there are no fine particles. In contrast, in the part where the fine particles are present, since the fine particles do not undergo curing shrinkage, only the photopolymerizable compound existing above and below the fine particles undergoes curing shrinkage. Thereby, the film thickness of the optical layer becomes thicker in the part where the fine particles are present than the part where the fine particles are not present, and therefore the surface of the optical layer becomes an uneven surface. Therefore, by appropriately selecting the type or particle size of the fine particles and the type of the photopolymerizable compound, and adjusting the coating film forming conditions, an optical layer with a special uneven surface can be formed.

The optical layer preferably contains a binder resin and fine particles, and is formed by the above method.

The above-mentioned binder resin contains a polymer (crosslinked product) of a photopolymerizable compound.

In addition to the polymer (crosslinked product) of the photopolymerizable compound, the above-mentioned binder resin may also contain a solvent drying resin or a thermosetting resin.

The photopolymerizable compound has at least one photopolymerizable functional group. In addition, in this specification, the "photopolymerizable functional group" is a functional group that can undergo polymerization reaction by light irradiation.

As such a photopolymerizable functional group, ethylenic double bonds, such as a (meth)acryloyl group, a vinyl group, and an allyl group, are mentioned, for example. Furthermore, the so-called "(meth)acryloyl" includes both the meaning of "acryloyl" and "methacryloyl".

In addition, examples of the light irradiated when the photopolymerizable compound is polymerized include visible rays, and free radiation such as ultraviolet rays, X-rays, electron beams, α rays, β rays, and γ rays.

As said photopolymerizable compound, a photopolymerizable monomer, a photopolymerizable oligomer, or a photopolymerizable polymer can be mentioned, for example, These can be adjusted suitably and used.

The photopolymerizable compound is preferably a combination of a photopolymerizable monomer and a photopolymerizable oligomer or a photopolymerizable polymer. In addition, when forming the above-mentioned mixed existence region, at least a photopolymerizable monomer is contained as a photopolymerizable compound.

The photopolymerizable monomer is preferably one having a weight average molecular weight of 1,000 or less. With the weight average molecular weight of the above-mentioned photopolymerizable monomer being 1000 or less, the photopolymerizable monomer can be made The solvent penetrates into the transparent substrate together with the solvent that penetrates into the transparent substrate. Thereby, it is possible to form a light-transmitting base material and a mixture containing the light-transmitting substrate near the interface between the light-transmitting base material and the optical layer to relax the refractive index of the light-transmitting base material and the optical layer. It is a region where the mixture exists as a monomer unit resin. In addition, not only one type of such photopolymerizable monomer can be used, but also a plurality of types can be used.

The photopolymerizable monomer is preferably a polyfunctional monomer having two (that is, bifunctional) or more photopolymerizable functional groups.

Examples of the above-mentioned bifunctional or more monomers include: trimethylolpropane tri(meth)acrylate, tripropylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, dipropylene glycol Di(meth)acrylate, neopentylerythritol tri(meth)acrylate, neopentylerythritol tetra(meth)acrylate, dineopentaerythritol hexa(meth)acrylate, 1,6-hexane Glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, di-trimethylolpropane tetra(meth)acrylate ( ditrimethylolpropane tetra(meth)acrylate), dineopentaerythritol penta(meth)acrylate, trineopentaerythritol octa(meth)acrylate, tetraneopentaerythritol deca(meth)acrylate, heterotrimer Cyanuric acid tri(meth)acrylate, isocyanuric acid di(meth)acrylate, polyester tri(meth)acrylate, polyester bis(meth)acrylate, bisphenol bis(meth)acrylate Acrylate, diglycerol tetra(meth)acrylate, adamantyl di(meth)acrylate, isobornyl di(meth)acrylate , Dicyclopentane di(meth)acrylate, tricyclodecane di(meth)acrylate, di-trimethylolpropane tetra(meth)acrylate, or use PO, EO, etc. to modify these Qualified ones.

Among them, from the viewpoint of obtaining an optical layer with a higher hardness, neopentylerythritol triacrylate (PETA), dineopentaerythritol hexaacrylate (DPHA), and neopentylerythritol are preferred. Tetraacrylate (PETTA), dineopentaerythritol pentaacrylate (DPPA), etc.

The aforementioned photopolymerizable oligomer has a weight average molecular weight of more than 1,000 and 10,000 or less.

The photopolymerizable oligomer is preferably a polyfunctional oligomer having two or more functions, and preferably a multifunctional oligomer having three (trifunctional) or more photopolymerizable functional groups.

Examples of the above-mentioned polyfunctional oligomer include polyester (meth)acrylate, urethane (meth)acrylate, polyester-(meth)acrylate, polyether ( Meth)acrylate, polyol (meth)acrylate, melamine (meth)acrylate, isocyanurate (meth)acrylate, epoxy (meth)acrylate, etc.

The photopolymerizable polymer has a weight average molecular weight of more than 10,000. As the weight average molecular weight, it is preferably more than 10,000 and 80,000 or less, and more preferably more than 10,000 and 40,000 or less. When the weight average molecular weight exceeds 80,000, the coating suitability may decrease due to higher viscosity, and the appearance of the obtained optical film may deteriorate.

As the above-mentioned multifunctional polymer, amine (meth)acrylate, isocyanurate (meth)acrylate, polyester-(meth)acrylate amine, epoxy (meth)acrylate, etc. may be mentioned .

The above-mentioned solvent-drying resin-based thermoplastic resin and the like become the resin of the film only by drying the solvent "added to adjust the solid content at the time of coating". In the case of adding a solvent-dried resin, it can effectively prevent coating defects on the coating surface of the coating solution when forming the optical layer. The solvent-drying resin is not particularly limited, and generally thermoplastic resins can be used.

Examples of the above-mentioned thermoplastic resins include: styrene resins, (meth)acrylic resins, vinyl acetate resins, vinyl ether resins, halogen-containing resins, alicyclic olefin resins, and polycarbonate resins. , Polyester resin, polyamide resin, cellulose Derivatives, silicone resin, rubber or elastomer, etc.

The above-mentioned thermoplastic resin is preferably non-crystalline and soluble in an organic solvent (especially a common solvent that can dissolve a plurality of polymers or curable compounds). Especially from the viewpoint of transparency or weather resistance, styrene resins, (meth)acrylic resins, alicyclic olefin resins, polyester resins, cellulose derivatives (cellulose esters, etc.) are preferred. )Wait.

The thermosetting resin is not particularly limited, and examples include phenol resins, urea resins, diallyl phthalate resins, melamine resins, guanamine resins, unsaturated polyester resins, polyurethane resins, Epoxy resin, aminoalkyd resin, melamine-urea co-condensation resin, silicone resin, polysiloxane resin, etc.

The above-mentioned fine particles can be either inorganic fine particles or organic fine particles. Among them, for example, silicon dioxide (SiO ₂ ) fine particles, alumina fine particles, titanium oxide fine particles, tin oxide fine particles, antimony-doped tin oxide (abbreviation: ATO) are preferred. ) Inorganic oxide particles such as particles and zinc oxide particles. The above-mentioned inorganic oxide fine particles can form aggregates in the optical layer, and a special uneven surface can be formed by the degree of aggregation of the aggregates.

Examples of the above-mentioned organic fine particles include plastic beads. As the plastic beads, specific examples include: polystyrene beads, melamine resin beads, acrylic beads, acrylic-styrene beads, silicone beads, benzoguanamine beads, benzene Guanamine-formaldehyde (benzoguanamine-formaldehyde) condensation beads, polycarbonate beads, polyethylene beads, etc.

The organic fine particles are preferably used to appropriately adjust the resistance of the fine particles to the hardening shrinkage during the hardening and shrinking. When adjusting the resistance to shrinkage, it is better to make a plurality of "organic particles with different hardnesses made by changing the degree of three-dimensional crosslinking" in advance. Optical film, and evaluate the clarity of the transparent image of the optical film to select the degree of crosslinking suitable for a special uneven surface.

When using inorganic oxide particles as the above-mentioned fine particles, it is preferable that the inorganic oxide particles have been surface-treated. By performing surface treatment on the above-mentioned inorganic oxide microparticles, the distribution of the microparticles in the optical layer can be better controlled, and the chemical resistance and saponification resistance of the microparticles themselves can also be improved.

As the above-mentioned surface treatment, a hydrophobic treatment for making the surface of the fine particles hydrophobic is preferable. Such a hydrophobization treatment can be obtained by chemically reacting the surface of the fine particles with a surface treatment agent such as silanes or silazanes. Specific surface treatment agents include, for example, dimethyldichlorosilane or polysiloxane oil, hexamethyldisilazane, octylsilane, hexadecylsilane, aminosilane, and methacrylic acid. Silane, octamethylcyclotetrasiloxane, polydimethylsiloxane, etc. When the fine particles are inorganic oxide fine particles, hydroxyl groups are present on the surface of the inorganic oxide fine particles. By performing the hydrophobization treatment as described above, the number of hydroxyl groups present on the surface of the inorganic oxide fine particles becomes The specific surface area measured by the BET method becomes smaller, and the excessive aggregation of fine inorganic oxide particles can be suppressed, and a functional layer with a special uneven surface can be formed.

In the case of using inorganic oxide particles as the above-mentioned fine particles, the inorganic oxide fine particles are preferably amorphous. The reason is that when the inorganic oxide particles are crystalline, the crystal lattice defects contained in the crystal structure of the inorganic oxide particles lead to the increase of the Lewis acid salt of the inorganic oxide particles, and the inorganic oxide cannot be controlled. There is a risk of excessive aggregation of oxide particles.

The content of fine particles in the optical layer is not particularly limited, but is preferably 0.1% by mass or more and 5.0% by mass or less. Since the content of fine particles is 0.1% by mass or more, a special uneven surface can be formed more reliably, and since the content of fine particles is 5.0% by mass or less, Therefore, agglomerates are not excessively generated, and internal diffusion and/or large unevenness on the surface of the functional layer can be suppressed, thereby suppressing the feeling of white turbidity. The lower limit of the content of fine particles is more preferably 0.2% by mass or more, and the upper limit of the content of fine particles is more preferably 3.0% by mass or less.

The above-mentioned fine particles are preferably spherical in a single particle state. Since the single particles of the microparticles have such a spherical shape, an image with excellent contrast can be obtained when the optical film is arranged on the image display surface of the image display device. Here, the "spherical shape" includes, for example, a true spherical shape, an elliptical spherical shape, etc., but does not include the so-called indefinite shape.

In the case of using organic fine particles as the above-mentioned fine particles, the difference in refractive index with the binder resin can be reduced by changing the copolymerization ratio of resins with different refractive indexes. For example, in terms of suppressing light diffusion caused by the fine particles , Preferably set to less than 0.01. The average primary particle diameter of the organic fine particles is preferably less than 8.0 μm, more preferably 5.0 μm or less.

The optical layer is preferably formed using fine particles that form loose aggregates in the above method. The so-called "loose agglomerate" means that the agglomerate of fine particles is not a block, but an agglomerate with a structure including a flexion formed by connecting primary particles and an inner region sandwiched by the flexion. Here, in this specification, the so-called "bending part" also includes the concept of a bending part. Examples of the shape having a bent portion include a V shape, a U shape, an arc shape, a C shape, a spiral shape, and a cage shape. The both ends of the above-mentioned flexion part may be closed, for example, it may be a ring structure with a flexion part.

The above-mentioned buckling part can be formed by connecting primary particles, and is composed of an aggregate of a buckled branch of fine particles, and can be formed by a stem formed by connecting the primary particles, and a branch formed by connecting the stem from the primary particles. It can also be composed of two branches branched from the stem and connected to the stem. The above-mentioned "cadres" refer to the most The long part.

The above-mentioned inner area is filled with adhesive resin. It is preferable that the said flexure part exists so that it may sandwich the inner region from the thickness direction of an optical layer.

Agglomerates that aggregate into blocks and become a binder resin when cured and contracted (polymerization shrinkage) of the photopolymerizable compound, which acts as a single solid, so the uneven surface of the optical layer corresponds to the shape of the aggregate . In contrast, the aggregate formed by loosely agglomerating fine particles has a flexure and an inner region sandwiched by the flexure, and therefore functions as a solid having a cushioning effect during hardening and shrinking. Therefore, the agglomerate formed by loosely agglomerating fine particles is easily and uniformly squashed during hardening and shrinking. As a result, compared with the case where the fine particles are aggregated into a block, the shape of the uneven surface is gentler, and it is not easy to locally produce a large uneven shape.

When the above-mentioned optical layer is formed of aggregates that are loosely aggregated, the size of the aggregates that are loosely aggregated can also be adjusted by adjusting the film thickness. That is, if the film thickness is thick, the size of the loosely aggregated aggregate is likely to become larger. Thereby, the size of the unevenness can be further increased, and the interval between the unevenness can be further enlarged.

In addition, as the fine particles forming loose aggregates, for example, inorganic oxide fine particles having an average primary particle diameter of 1 nm or more and 100 nm or less are preferable. Since the average primary particle size of the fine particles is 1nm or more, it is easier to form an optical layer with a special uneven surface. In addition, since the average primary particle size is 100nm or less, the light diffusion caused by the fine particles can be suppressed. Excellent dark room contrast. The lower limit of the average primary particle size of the fine particles is more preferably 5 nm or more, and the upper limit of the average primary particle size of the fine particles is more preferably 50 nm or less. Furthermore, the average primary particle size of the particles is based on the cross-sectional electron microscope (preferably TEM, STEM, etc.) The value measured by image processing software is used for the image of 50,000 times or more.

When inorganic oxide fine particles are used as the above-mentioned fine particles forming loose aggregates, the unevenness of the uneven surface of the optical layer is preferably formed only of inorganic oxide fine particles. The so-called "concavity and convexity of the concave and convex surface of the optical layer are formed only by inorganic oxide fine particles" means that the concavity and convexity of the concave and convex surface of the optical layer is formed by fine particles other than inorganic oxide fine particles, except for inorganic oxide fine particles. Situation. The term "substantially not included" here means that if it is a fine particle that does not form the uneven surface of the optical layer, or even if the unevenness is formed, it is a small amount that does not affect the anti-reflective property, the optical layer may also include inorganic oxide Particles other than particles.

Among the above-mentioned inorganic oxide microparticles, fumed silica is particularly preferred in terms of forming loose aggregates and easily forming special uneven surfaces.

The above-mentioned so-called smoked silicon dioxide is an amorphous silicon dioxide with a particle size of 200 nm or less produced by a dry method, which can be obtained by reacting volatile compounds containing silicon in the gas phase. Specifically, for example, a silicon compound such as silicon tetrachloride (SiCl ₄ ) is hydrolyzed in a flame of oxygen and hydrogen to be produced. As a commercially available product of the above-mentioned fumigated silica, for example, AEROSIL R805 manufactured by Japan Aerosil Corporation can be cited.

Among the above-mentioned fumigated silicas, there are those exhibiting hydrophilicity and those exhibiting hydrophobicity. Among them, it is preferable to exhibit hydrophobicity from the viewpoint of reducing water absorption and being easily dispersed in the composition for the functional layer. By.

The hydrophobic fumigated silica can be obtained by chemically reacting the silanol groups present on the surface of the fumigated silica with the above-mentioned surface treatment agent. From the standpoint of easily obtaining the agglomerates as described above, it is best to treat the silicon dioxide with octylsilane.

The BET specific surface area of the fumigated silica is preferably 100 m ² /g or more and 200 m ² /g or less. By setting the BET specific surface area of the fumigated silica to be more than 100m ² /g, the fumigated silica will not be over-dispersed, and it is easy to form a moderate agglomerate. Moreover, by setting the BET specific surface area of the fumigated silica The specific surface area is set to 200m ² /g or less, and it is difficult to form excessively large aggregates in the smoked silica. The lower limit of the BET specific surface area of the smoked silica is more preferably 120 m ² /g, and more preferably 140 m ² /g. The upper limit of the BET specific surface area of the smoked silica is more preferably 180 m ² /g, and still more preferably 165 m ² /g.

Such an optical layer can be formed by the following method, for example.

First, the following optical layer composition is applied to the surface of the above-mentioned translucent substrate.

Examples of methods for coating the above-mentioned optical layer composition include spin coating, dipping, spraying, slanting coating, bar coating, roll coating, gravure coating, and die coating. Well-known coating methods such as nozzle coating method.

The composition for the optical layer contains at least the photopolymerizable compound and the fine particles. In addition, the above-mentioned thermoplastic resin, the above-mentioned thermosetting resin, a solvent, and a polymerization initiator may be added to the composition for an optical layer as necessary. Furthermore, in the optical layer composition, it is also possible to add previously known dispersing agents, surfactants, antistatic agents, silane coupling agents, and thickening agents for the purpose of improving the hardness of the optical layer, suppressing curing shrinkage, and controlling the refractive index. Agents, anti-coloring agents, coloring agents (pigments, dyes), defoamers, leveling agents, flame retardants, ultraviolet absorbers, adhering agents, polymerization inhibitors, antioxidants, surface modifiers, slip agents, etc. .

The above solvent can be used for the following purposes: to easily apply the composition for the optical layer to adjust the viscosity; or to adjust the evaporation rate or the dispersibility of the fine particles, adjust the degree of aggregation of the fine particles when the optical layer is formed, and easily form special unevenness surface.

烷、二氧雜環戊烷、四氫呋喃等)、脂肪族烴類(己烷等)、脂環式烴類(環己烷等)、芳香族烴類(甲苯、二甲苯等)、鹵化碳類(二氯甲烷、二氯乙烷等)、酯類(甲酸甲酯、乙酸甲酯、乙酸乙酯、乙酸丙酯、乙酸丁酯、乳酸乙酯等)、賽珞蘇(cellosolve)類(甲基賽珞蘇、乙基賽珞蘇、丁基賽珞蘇等)、乙酸賽珞蘇類、亞碸類(二甲基亞碸等)、醯胺類(二甲基甲醯胺、二甲基乙醯胺等)等，亦可為該等之混合物。 As such a solvent, for example, alcohol (for example, methanol, ethanol, propanol, isopropanol, n-butanol, sec-butanol, tert-butanol, benzyl alcohol, PGME, ethylene glycol), ketones ( Acetone, methyl ethyl ketone (MEK), cyclohexanone, methyl isobutyl ketone, diacetone alcohol, cycloheptanone, diethyl ketone, etc.), ethers (1,4-di

Alkanes, dioxolane, tetrahydrofuran, etc.), aliphatic hydrocarbons (hexane, etc.), alicyclic hydrocarbons (cyclohexane, etc.), aromatic hydrocarbons (toluene, xylene, etc.), halogenated carbons (Dichloromethane, dichloroethane, etc.), esters (methyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, ethyl lactate, etc.), cellosolve (A Glycerol, ethyl serosol, butyl serosol, etc.), serosol acetate, sulfinates (dimethyl sulfoxide, etc.), amides (dimethylformamide, dimethyl Acetamide, etc.), etc., may also be a mixture of these.

In addition, as described above, when a mixed region is formed near the interface between the light-transmitting substrate and the optical layer, as the above-mentioned solvent, a solvent containing a transparent base having high permeability to the light-transmitting substrate is used. The material is dissolved or swelled by a penetrating solvent, and as the photopolymerizable compound, one containing at least a photopolymerizable monomer with a weight average molecular weight of 1000 or less is used.

By using the above-mentioned penetrating solvent and photopolymerizable monomer, not only the penetrating solvent penetrates into the light-transmitting substrate, the photopolymerizable monomer also penetrates into the light-transmitting substrate, so it can be combined with the light-transmitting substrate. In the vicinity of the interface of the optical layer, a mixed region of "transparent base material and resin containing photopolymerizable monomers as monomer units are mixed" is formed.

烷、二氧雜環戊烷、四氫呋喃等)、賽珞蘇類(甲基賽珞蘇、乙基賽珞蘇、丁基賽珞蘇等)、乙酸賽珞蘇類、亞碸類(二甲基亞碸等)、酚類(苯酚、鄰氯苯酚)等。又，亦可為該等之混合物。於使用三乙醯纖 維素基材作為透光性基材之情形時，於該等中，作為滲透性溶劑，例如較佳為選自由甲基異丁基酮、甲基乙基酮、環己酮、乙酸甲酯、乙酸乙酯、乙酸丙酯、乙酸丁酯所組成之群中之至少1種，又，於使用聚酯基材作為透光性基材之情形時，較佳為鄰氯苯酚(ortho chlorophenol)。 Examples of the above-mentioned permeable solvent include: ketones (acetone, methyl ethyl ketone (MEK), cyclohexanone, methyl isobutyl ketone, diacetone alcohol, cycloheptanone, diethyl ketone), esters (Methyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, ethyl lactate, etc.), ethers (1,4-di

Alkane, dioxolane, tetrahydrofuran, etc.), serosols (methyl serosol, ethyl serosol, butyl serosol, etc.), serosol acetate, sulfinate (dimethyl Sulfite, etc.), phenols (phenol, o-chlorophenol), etc. Moreover, it may be a mixture of these. In the case of using a triacetyl cellulose substrate as a translucent substrate, among these, the penetrating solvent is preferably selected from methyl isobutyl ketone, methyl ethyl ketone, and cyclohexane. At least one of the group consisting of ketone, methyl acetate, ethyl acetate, propyl acetate, and butyl acetate. In addition, when a polyester substrate is used as a translucent substrate, o-chloride is preferred Phenol (ortho chlorophenol).

The above-mentioned polymerization initiator is a component that decomposes by light irradiation, generates radicals, and starts or proceeds polymerization (crosslinking) of the photopolymerizable compound.

(thioxanthone)類、苯丙酮類、苯偶醯類、安息香類、醯基氧化膦類。又，較佳為混合光增感劑而使用，作為其具體例，例如可列舉：正丁基胺、三乙基胺、聚正丁基膦等。 Such a polymerization initiator is not particularly limited as long as it can release a substance that initiates radical polymerization by light irradiation, and those known in the past can be used. Specific examples include, for example, acetophenones and benzophenones. Ketones, Michler's benzoyl benzoate, α-amyloxime, 9-oxysulfur

(thioxanthone), phenylacetone, benzil, benzoin, phosphine oxide. Moreover, it is preferable to mix and use a photosensitizer, and as a specific example, n-butylamine, triethylamine, poly-n-butylphosphine, etc. are mentioned, for example.

類、安息香、安息香甲醚等。 As the polymerization initiator, when the binder resin is a resin system having a radically polymerizable unsaturated group, it is preferable to use acetophenones, benzophenones, and 9-oxysulfur singly or in combination.

Class, benzoin, benzoin methyl ether, etc.

The content of the polymerization initiator in the composition for the optical layer is preferably 0.5 parts by mass or more and 10.0 parts by mass or less with respect to 100 parts by mass of the photopolymerizable compound. By setting the content of the polymerization initiator within this range, the hard coat performance can be sufficiently maintained and hardening inhibition can be suppressed.

The content ratio (solid content) of the raw material in the composition for the optical layer is not particularly limited, but it is usually preferably 5 mass% or more and 70 mass% or less, and more preferably 25 mass% or more and 60 mass% or less.

As the above-mentioned leveling agent, for example, silicone oil, fluorine-based surfactant, etc. are preferable in terms of preventing the optical layer from becoming a Benard cell structure. When the solvent-containing resin composition is applied and dried, a difference in surface tension, etc., occurs on the surface and inner surface of the coating film in the coating film, thereby causing a large amount of convection in the coating film. The structure produced by this convection is called the Benard cavitation structure, which causes problems such as orange peel or coating defects in the formed optical layer.

The above-mentioned Benardian flow structure may cause the irregularities on the surface of the optical layer to become too large. If the leveling agent as described above is used, the convection can be prevented, so not only a defect-free or uneven optical layer can be obtained, but also the unevenness of the surface of the optical layer can be easily adjusted.

The method for preparing the composition for the optical layer is not particularly limited as long as the components can be uniformly mixed. For example, it can be performed using a known device such as a paint shaker, a bead mill, a kneader, and a stirrer.

After coating the optical layer composition on the surface of the above-mentioned translucent substrate, in order to dry the coated optical layer composition and transport it to the heated area, the optical layer composition is made by various well-known methods Dry to evaporate the solvent. Here, the aggregation state or distribution state of the particles can be adjusted by selecting the relative evaporation rate of the solvent, the concentration of the solid content, the temperature of the coating solution, the drying temperature, the wind speed of the drying wind, the drying time, the concentration of the solvent environment in the drying area, etc. .

In particular, the method of adjusting the distribution of fine particles by selecting drying conditions is simple and preferable.

For example, by lowering the drying temperature and/or reducing the drying wind speed, the drying speed is slowed down, whereby the particles are more likely to agglomerate. Therefore, it can be easily formed into a shape with larger unevenness and a wider interval between the unevennesses.

The specific drying temperature is preferably 30 to 120°C, and the drying wind speed is preferably 0.2 to 50 m/s. By performing one or more drying treatments within this range, the particles can be Adjust the distribution status to the required status.

Furthermore, when the composition for the optical layer is dried, the penetrating solvent that has penetrated into the light-transmitting substrate evaporates, and the photopolymerizable compound remains in the light-transmitting substrate.

Thereafter, the coating film-like optical layer composition is irradiated with light such as ultraviolet rays to polymerize (crosslink) the photopolymerizable compound, and the optical layer composition is cured to form the optical layer and form the mixed region.

When ultraviolet rays are used as the light for curing the above-mentioned optical layer composition, ultraviolet rays emitted from ultrahigh pressure mercury lamps, high pressure mercury lamps, low pressure mercury lamps, carbon arcs, xenon arcs, metal halide lamps, etc. can be used. In addition, as the wavelength of ultraviolet rays, a wavelength range of 190 to 380 nm can be used. Specific examples of electron beam sources include: Cockcroft-Walton type, Van de Graaff type, resonance transformer type, insulated core transformer type, or linear type, Various electron beam accelerators such as Dynamitron and high frequency.

Furthermore, by using a photopolymerizable compound and a solvent-drying resin as the material for forming the binder resin, it is also possible to form an optical layer with a special uneven surface.

Specifically, for example, a composition for an optical layer containing a photopolymerizable compound, a solvent drying resin, and fine particles is used, and a coating film of the composition for an optical layer is formed on a translucent substrate by the same method as described above. The composition for the optical layer is cured in the same manner as described above.

When a photopolymerizable compound and a solvent-drying resin are used in combination as the material for forming the above-mentioned binder resin, the viscosity can be increased and the curing shrinkage (polymerization shrinkage) can be reduced compared to the case of using only the photopolymerizable compound. Therefore, it can form the uneven surface of the optical layer without following the shape of the particles during drying and curing, thereby forming a special uneven surface. However, since the uneven shape of the uneven surface of the optical layer is affected by the film thickness of the optical layer, etc., When forming the optical layer, of course, the film thickness of the optical layer must be adjusted appropriately.

Furthermore, in the present invention, the optical layer may have a single-layer structure or a multilayer structure of two or more layers as long as it satisfies the above-mentioned formulas (1) and (2). In addition, in the present invention, the optical layer As long as it satisfies the half-value width of the above-mentioned surface height distribution and the average curvature of the surface concavities and convexities, it can be a single-layer structure or a multilayer structure of two or more layers.

Specifically, the optical layer may have a two-layer structure composed of a base uneven layer whose surface becomes an uneven surface and a surface adjustment layer formed on the base uneven layer.

The above-mentioned base concavo-convex layer may be an optical layer.

The surface adjustment layer is a layer used to fill in the fine unevenness existing on the surface of the base uneven layer to obtain a smooth uneven surface and/or to adjust the interval, size, etc. of the unevenness existing on the surface of the uneven layer. The surface of the surface adjustment layer becomes an uneven surface, and the uneven surface of the surface adjustment layer becomes a special uneven surface. However, when the optical layer has a multilayer structure, the manufacturing steps may become complicated, and the management of the manufacturing steps may become difficult compared to the case of a single-layer structure. Therefore, the optical layer is preferably a single-layer structure.

From the viewpoint of adjusting the unevenness, the film thickness of the surface adjustment layer is preferably 0.5 μm or more and 20 μm or less. The upper limit of the film thickness of the surface adjustment layer is more preferably 12 μm or less, and still more preferably 8 μm or less. The lower limit of the film thickness of the surface adjustment layer is preferably 3 μm or more.

The optical layer composed of the above-mentioned base uneven layer and the surface adjustment layer can be formed by the following method using the base uneven layer composition and the surface adjustment layer composition as the optical layer composition.

As the composition for the base concavo-convex layer, the same composition as the composition for the optical layer described in the section of the composition for the optical layer can be used. Also, as a surface adjustment layer As the composition, a composition containing at least the same photopolymerizable compound as the photopolymerizable compound described in the column of the above-mentioned binder resin can be used. In addition to the photopolymerizable compound, the composition for the surface adjustment layer may contain the same leveling agent or solvent as the leveling agent or solvent described in the column of the composition for the optical layer.

When forming an optical layer composed of the above-mentioned base uneven layer and a surface adjustment layer, firstly, a composition for base uneven layer is coated on a translucent substrate, and a composition for base uneven layer is formed on the translucent substrate The coating film of the thing.

Then, after drying the coating film, the coating film is irradiated with light such as ultraviolet rays to polymerize (crosslink) the photopolymerizable compound to harden the base uneven layer composition, thereby forming the base uneven layer.

After that, the surface adjustment layer composition is coated on the base uneven layer to form a coating film of the surface adjustment layer composition. Then, after the coating film is dried, the photopolymerizable compound is polymerized (crosslinked) by irradiating the coating film with light such as ultraviolet rays to harden the composition for the surface adjustment layer to form the surface adjustment layer. In this way, even if the fine particles forming loose aggregates are not used, an optical layer with a special uneven surface can be formed. However, since the concave-convex shape of the concave-convex surface of the optical layer is also affected by the drying conditions of the coating film, and the film thickness of the base concave-convex layer and the surface adjustment layer, the optical layer is naturally formed by this method. It is also necessary to appropriately adjust the drying conditions of the coating film and the film thickness of the base uneven layer and surface adjustment layer.

The above-mentioned optical film preferably has a total light transmittance of 85% or more. If the total light transmittance is 85% or more, when the optical film is mounted on the surface of the image display device, the color reproducibility or visibility can be further improved. The above-mentioned total light transmittance is more preferably 90% or more. The total light transmittance can be measured by a haze meter (manufactured by Murakami Color Research Institute, product number: HM-150) by a method based on JIS K7361.

On the surface of the optical film, the three-dimensional average inclination angle θ a _3D of the unevenness constituting the surface is preferably 0.12° or more and 0.5° or less, more preferably 0.15° or more and 0.4° or less.

On the surface of the above-mentioned optical film, the average peak spacing Smp of the unevenness constituting the surface is preferably 0.05 mm or more and 0.3 mm or less, more preferably 0.10 mm or more and 0.25 mm or less.

On the surface of the optical film, the arithmetic average roughness Ra of the concavities and convexities constituting the surface is preferably 0.01 μm or more and 0.11 μm or less, more preferably 0.035 μm or more and 0.08 μm or less.

On the surface of the optical film, the 10-point average roughness Rz of the unevenness constituting the surface is preferably 0.10 μm or more and 0.30 μm or less, more preferably 0.12 μm or more and 0.28 μm or less.

The above-mentioned "θ a _3D ", "Smp", "Ra" and "Rz" can be determined by contact surface roughness meter or non-contact surface roughness meter (such as interference microscope, confocal microscope, atomic force microscope, etc.) It is calculated by measuring the obtained three-dimensional roughness surface. The data of the above-mentioned three-dimensional roughness surface is expressed in the following way: on the reference plane (the horizontal direction is set to the x-axis, the vertical direction is set to the y-axis), the height of a grid-like point and the position of the point is arranged at an interval d Said.

That is, if the height of the position of the i-th point in the x-axis direction and the j-th point in the y-axis direction (hereinafter referred to as (i,j)) is set to Z _i,j , it is at any position (i,j) , The slope Sx in the x-axis direction with respect to the x-axis and the slope Sy in the y-axis direction with respect to the y-axis are calculated as follows.

Sx=(Z _i+1,j -Z _i-1,j )/2d

Sy=(Z _i,j+1 -Z _i,j-1 )/2d

Furthermore, the slope St of (i, j) with respect to the reference plane is calculated by the following formula.

In addition, the inclination angle of (i, j) is calculated by tan ^-1 (St).

In terms of simplicity, the above-mentioned three-dimensional roughness curved surface is preferably measured using an interference microscope. Examples of such interference microscopes include the "New View" series manufactured by Zygo Corporation.

In addition, the above-mentioned three-dimensional average tilt angle θ a _3D is calculated from the average value of the tilt angles of each point.

In addition, the average peak interval Smp of the above-mentioned unevenness in the present invention is obtained as follows.

If the number of peaks when the part of the above-mentioned three-dimensional roughness surface is higher than the reference surface and surrounded by a region as a peak is set to Ps, and the area of the entire measurement area (reference surface) is set to A, then Smp is below The formula is calculated.

In addition, the arithmetic average roughness Ra of the concavity and convexity in the present invention is one that expands Ra as a two-dimensional roughness parameter described in JIS B0601: 1994 into three dimensions. If the orthogonal coordinate axes X and Y are set on the reference plane, Set the roughness surface as Z(x, y) and the size of the reference surface as Lx and Ly, then calculate it with the following formula.

A=Lx×Ly

Moreover, if the above-mentioned Zi _{,j is used} , the arithmetic average roughness Ra of the above-mentioned unevenness is calculated by the following formula.

N: total points

The 10-point average roughness Rz in the present invention is based on JIS B0601: 1994 The Rz, which is a two-dimensional roughness parameter, described in is expanded to three-dimensional.

That is, a large number of straight lines passing through the center of the reference surface are arranged radially 360 degrees on the reference surface so as to cover the whole area, and a cross-sectional curve cut based on each straight line is obtained from the three-dimensional roughness surface, and 10 of the cross-sectional curve is obtained. Point average roughness (the sum of the average value of the height from the highest peak to the fifth highest peak height in sequence and the average of the depth from the deepest valley bottom to the fifth deepest valley in sequence). It is calculated by averaging the top 50% of the large number of ten-point average roughness thus obtained.

In addition, as the optical film of the present invention can better prevent reflection and Newton's ring generation, or watermark generation, the above-mentioned optical layer is preferably one with a low refractive index layer laminated on a concave-convex layer having concave and convex shapes on the surface constitute.

Examples of the above-mentioned uneven layer include those formed by the same composition and method as the above-mentioned optical layer containing a binder resin and fine particles.

The above-mentioned low refractive index layer is a layer that reduces the reflectivity of the optical film when light from the outside (such as fluorescent lamps, natural light, etc.) is reflected on the surface of the optical film. The low refractive index layer is preferably composed of any of the following: 1) resin containing low refractive index particles such as silicon dioxide and magnesium fluoride; 2) fluorine resin containing low refractive index resin; 3) containing Fluorine resins of silicon dioxide or magnesium fluoride, 4) thin films of low refractive index materials such as silicon dioxide and magnesium fluoride. Regarding resins other than fluorine-based resins, the same resins as the above-mentioned binder resin constituting the optical layer can be used.

In addition, the above-mentioned silicon dioxide is preferably hollow silicon dioxide microparticles. Such hollow silicon dioxide microparticles can be produced, for example, by the manufacturing method described in the Examples of JP 2005-099778 A. The refractive index of the low refractive index layers is preferably 1.45 or less, and particularly preferably 1.42 or less. In addition, the thickness of the low refractive index layer is not limited, and it is usually set appropriately within the range of about 30 nm to 1 μm.

In addition, the above-mentioned low-refractive index layer can be effective in a single layer, but in order to adjust a lower minimum reflectance or a higher minimum reflectance, two or more low-refractive index layers may be appropriately provided. In the case of providing the above-mentioned two or more low refractive index layers, it is preferable to provide a difference in the refractive index and thickness of each low refractive index layer.

As the above-mentioned fluorine-based resin, a polymerizable compound containing at least a fluorine atom in the molecule or a polymer thereof can be used. The polymerizable compound is not particularly limited. For example, it is preferably one having a curing reactive group such as a functional group that is cured by free radiation and a thermosetting polar group. Moreover, it may be a compound which has these reactive groups at the same time. With respect to the polymerizable compound, the so-called polymer system does not have any such reactive groups as described above.

As the above-mentioned polymerizable compound having a functional group hardened by free radiation, a fluorine-containing monomer having an ethylenically unsaturated bond can be widely used. More specifically, fluoroolefins (for example, vinyl fluoride, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, perfluorobutadiene, perfluoro-2,2-dimethyl-1,3-di Oxolone, etc.). As those having a (meth)acryloyloxy group, there are also: 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3,3-pentafluoropropyl (meth)acrylate , 2-(perfluorobutyl)ethyl (meth)acrylate, 2-(perfluorohexyl)ethyl (meth)acrylate, 2-(perfluorooctyl)ethyl (meth)acrylate, (meth)acrylate (Meth)acrylate compounds having fluorine atoms in the molecule, such as 2-(perfluorodecyl)ethyl acrylate, α-trifluoromethyl methacrylate, α-trifluoroethyl methacrylate; The molecule has a fluoroalkyl, fluorocycloalkyl or fluoroalkylene group containing at least 3 fluorine atoms and a carbon number of 1 to 14, and at least 2 (meth)acryloyloxy fluorine-containing polyfunctional (methyl ) Acrylate compounds, etc.

As the above-mentioned thermosetting polar group, a hydrogen bond forming group such as a hydroxyl group, a carboxyl group, an amino group, and an epoxy group is preferable. These not only have excellent adhesion to the coating film, but also interact with silica, etc. The affinity of inorganic ultrafine particles is also excellent. Examples of polymerizable compounds having a thermosetting polar group include: 4-fluoroethylene-perfluoroalkyl vinyl ether copolymer; fluoroethylene-hydrocarbon vinyl ether copolymer; epoxy, polyurethane, cellulose, Fluorine-modified products of various resins such as phenol and polyimide.

Examples of the above-mentioned polymerizable compound having both a functional group hardened by free radiation and a polar group hardened by heat include: partially and completely fluorinated alkyl, alkenyl, and aryl esters of acrylic acid or methacrylic acid, and complete Or partially fluorinated vinyl ethers, fully or partially fluorinated vinyl esters, fully or partially fluorinated vinyl ketones, etc.

In addition, as the fluorine-based resin, for example, the following can be cited.

A polymer containing at least one monomer or monomer mixture of a fluorine-containing (meth)acrylate compound of a polymerizable compound having a free radiation-curable group; at least one of the above-mentioned fluorine-containing (meth)acrylate compound Not contained in molecules such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate Copolymers of (meth)acrylate compounds with fluorine atoms; such as vinyl fluoride, vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, 3,3,3-trifluoropropylene, 1,1,2-trichloro -3,3,3-Trifluoropropylene, hexafluoropropylene homopolymer or copolymer of fluorine-containing monomer, etc. Polysiloxane-containing vinylidene fluoride copolymers obtained by including polysiloxane components in these copolymers can also be used. As the polysiloxane component in this case, (poly)dimethylsiloxane, (poly)diethylsiloxane, (poly)diphenylsiloxane, (poly)methylphenyl can be exemplified Silicone, alkyl modified (poly)dimethylsiloxane, azo-containing (poly)dimethylsiloxane, dimethylpolysiloxane, phenylmethylpolysiloxane, alkyl /Aralkyl modified polysiloxane, fluoropolysiloxane, polyether modified polysiloxane, fatty acid ester modified polysiloxane, methyl hydrogen polysiloxane, polysiloxane containing silanol groups, polysiloxane containing alkyl Modification of oxy-based polysiloxane, phenol-containing polysiloxane, and methacrylic acid base Polysiloxane, acrylic modified polysiloxane, amine modified polysiloxane, carboxylic acid modified polysiloxane, methanol modified polysiloxane, epoxy modified polysiloxane, sulfhydryl modified polysiloxane , Fluorine modified polysiloxane, polyether modified polysiloxane, etc. Among them, those having a dimethylsiloxane structure are preferred.

Furthermore, non-polymers or polymers composed of the compounds shown below may also be Used as fluorine resin. That is, a compound obtained by reacting a fluorine-containing compound having at least one isocyanate group in the molecule and a compound having at least one functional group that reacts with an isocyanate group such as an amino group, a hydroxyl group, and a carboxyl group in the molecule can be used; Fluorine-containing polyether polyol, fluorine-containing alkyl polyol, fluorine-containing polyester polyol, fluorine-containing ε-caprolactone modified polyol, fluorine-containing polyol and isocyanate group-containing compound react Obtained compounds, etc.

Moreover, each binder resin as described in the said optical layer can also be mixed and used together with the polymerizable compound or polymer which has the said fluorine atom. Furthermore, curing agents for hardening reactive groups, etc., various additives and solvents for improving coatability or imparting antifouling properties can be suitably used.

When forming the above-mentioned low refractive index layer, it is preferable to set the viscosity of the composition for the low refractive index layer to which a low refractive index agent and resin are added to 0.5~5mPa‧s (25 ℃), preferably in the range of 0.7~3mPa‧s (25℃). An optical layer with excellent visible light can be realized, a uniform film without uneven coating can be formed, and a low refractive index layer with particularly excellent adhesion can be formed.

The means for curing the resin may be the same as that described in the above-mentioned optical layer. In the case of using a heating means for curing treatment, it is preferable to add a thermal polymerization initiator that generates, for example, radicals by heating to initiate polymerization of the polymerizable compound to the fluorine-based resin composition.

The thickness (nm) d _{A of the} low refractive index layer is preferably one that satisfies the following formula (A): d _A =m λ/(4n _A ) (A)

(In the above formula, n _A represents the refractive index of the low refractive index layer, m represents a positive odd number, preferably 1, and λ is the wavelength, preferably a value in the range of 480 to 580 nm).

Furthermore, in the present invention, in terms of reducing reflectance, the low refractive index layer preferably satisfies the following formula (B): 120<n _A d _A <145 (B).

According to the present invention, since the penetration image of the optical film measured by the optical comb with a width of 0.125mm is set to C(0.125), the penetration image of the optical film measured by the optical comb with a width of 0.25mm is set as C(0.125) When the clarity is set to C (0.25), the optical film satisfies the above formula (1) and formula (2), so even if the optical film has a low total haze of 0% or more and 5% or less and has 0% or more and 5 The lower internal haze below% can also suppress glare and suppress reflection and watermark for the above reasons.

Furthermore, according to the present invention, since the half-value width of the surface height distribution of the optical film and the average curvature of the surface concavities and convexities satisfy the above-mentioned specific numerical range, the concavity and convexity of the optical film surface becomes the specific concavity and convexity shape. Even if the optical film has a low total haze of 0% or more and 5% or less and a low internal haze of 0% or more and 5% or less, for the above reasons, glare can be suppressed and watermark can be controlled.

Here, the total haze value and the internal haze value are the values when the entire optical film is measured.

Furthermore, the above total haze value and internal haze value can be used with a haze meter (HM-150, Murakami Manufactured by Cai Technology Research Institute), measured by a method based on JIS K7136.

Specifically, a haze meter is used to measure the total haze value of the optical film in accordance with JIS K7136.

Thereafter, a triacetyl cellulose substrate (manufactured by Fuji Film Co., TD60UL) was attached to the surface of the optical film via a transparent optical adhesive layer.

Thereby, the uneven shape of the surface of the optical film is crushed, and the surface of the optical film becomes flat.

Then, in this state, using a haze meter (HM-150, manufactured by Murakami Color Research Institute), the haze value was measured in accordance with JIS K7136, thereby obtaining the internal haze value.

The internal haze does not consider the unevenness of the surface of the optical film.

In the display device with a touch panel of the present invention, the total haze value of the optical film is preferably 1% or less, more preferably 0.3% or more and 0.5% or less.

The internal haze value is preferably substantially 0%.

Here, the so-called "internal haze value is substantially 0%" means the following: it is not limited to the case where the internal haze value is completely 0%, and includes even when the internal haze value exceeds 0%. Within the range of measurement error and the internal haze value can be roughly regarded as the range of 0% (for example, the internal haze value below 0.3%).

When the total haze value of the above-mentioned optical film is 0% or more and 5% or less, and the internal haze value is 0% or more and 5% or less, the surface haze value of the optical film becomes 0% or more and 5% or less.

The surface haze value of the optical film is preferably 0% or more and 1% or less, more preferably 0% or more and 0.3% or less.

The surface haze value is caused only by the unevenness of the surface of the optical film. By subtracting the internal haze value from the total haze value, the surface haze caused only by the unevenness of the surface of the optical film can be obtained. value.

In the case of using inorganic oxide particles with an average primary particle size of 1 nm or more and 100 nm or less (for example, smoked silica) as the above particles to form the optical layer, a lower total haze value (for example, 1%) The following total haze value) and lower internal haze value (for example, an internal haze value of substantially 0%) optical film. That is, since the total haze and internal haze of the optical film are the ratio of the transmitted light that deviates from the incident light by 2.5° or more due to forward scattering in the transmitted light through the optical film, so long as the deviation from the incident light can be reduced If the ratio of penetrating light is above 2.5°, the total haze value and internal haze will be lower. On the other hand, since the inorganic oxide microparticles with an average primary particle diameter of 100 nm or less do not aggregate into lumps in the optical layer, but form loose aggregates, the light penetrating the optical layer is not easy to diffuse in the optical layer. Therefore, when the optical layer is formed using inorganic oxide fine particles with an average primary particle size of 1 nm or more and 100 nm or less, the generation of transmitted light deviating from the incident light by more than 2.5° can be suppressed, thereby obtaining the total haze Optical film with lower value and internal haze value.

When the uneven surface of the optical layer is formed by only inorganic oxide fine particles, it is easy to form an uneven surface with gentle and uniform unevenness, that is, an uneven surface with less curvature, which can obtain anti-reflective properties and water-repellent marks. . Therefore, an optical film with lower total haze value and internal haze value and can further suppress glare can be obtained.

According to the present invention, since the total haze value of the optical film becomes 0% or more and 5% or less, and the internal haze value becomes 0% or more and 5% or less, the decrease in brightness or light transmittance can be suppressed. In addition, since the diffusion of the image light inside the optical film can be suppressed, part of the image light does not become stray light. As a result, there is no risk of lowering the contrast of the dark room, and no image blurring. With this, the above optical film can be integrated into ultra-high-definition small mobile devices, or such as 4K2K (horizontal pixels 3840×vertical pixels 2160) is used in ultra-high-definition image display devices where the number of horizontal pixels is 3000 or more.

According to the present invention, since the optical film is provided with the optical layer having the uneven surface, it is possible to suppress the interference of the light reflected at the interface between the translucent substrate and the optical layer and the light reflected on the uneven surface of the optical layer. Thereby, the generation of interference fringes can be suppressed. In addition, when a mixed region is formed, reflection at the interface between the light-transmitting substrate and the optical layer can be suppressed, so that the generation of interference fringes can be further suppressed.

When the concavities and convexities of the concavo-convex surface of the optical layer are formed by only inorganic oxide fine particles, it is easy to make the inclination angle of the concavities and convexities constituting the concavity and convexity surface not large. In this way, excessive diffusion of external light will not occur, and therefore the decrease in the contrast of the bright room can be suppressed. In addition, the image light can be prevented from becoming stray light, and therefore, a good dark room contrast can also be obtained. Furthermore, since it has a moderate specular reflection component, when a moving image is displayed, the illuminance or brightness of the image increases, and a feeling of jump can be obtained. Thereby, a black color feeling with both excellent contrast and pulsation can be obtained.

Furthermore, optical films satisfying the above formulas (1) and (2) can also be used to provide a method for improving glare and watermark.

In addition, an optical film that satisfies the surface height distribution of the above-mentioned optical film with a half-value width of 200 nm or more and an average curvature of surface concavities and convexities of 0.30 mm ^-1 or less can be used to provide a method for improving glare and watermark.

The above-mentioned optical film can be used in, for example, a 4K2K (horizontal pixel count of 3840×vertical pixel count of 2160) such as 4K2K (horizontal pixel count 3840×vertical pixel count 2160) in an ultra-high-definition image display device with 3000 or more horizontal pixels. Examples of image display devices include: liquid crystal displays (LCD), cathode ray tube display devices (CRT), plasma displays (PDP), electroluminescence displays (ELD), field emission displays Device (FED), touch panel, tablet PC, electronic paper, etc.

The above-mentioned image display device is preferably a liquid crystal display with a horizontal pixel count of 3000 or more. The image display device is composed of a backlight unit and a liquid crystal panel with an optical film arranged on the side of the observer more than the backlight unit. As the backlight unit, a known backlight unit can be used. As the aforementioned backlight, quantum dot LEDs can also be used.

Since the optical film of the present invention is formed with a specific concave-convex shape, the generation of glare can be sufficiently suppressed, and a high-quality display image can be obtained.

In addition, the display device with a touch panel of the present invention has a specific concave-convex shape formed on the surface of the optical film opposite to the touch panel, so that the generation of watermark and glare can be sufficiently suppressed, and high-quality display images can be obtained. Like.

Therefore, the optical film of the present invention can be preferably applied to cathode ray tube display devices (CRT), liquid crystal displays (LCD), plasma displays (PDP), electroluminescence displays (ELD), field emission displays (FED), Electronic paper, tablet PC, etc.

11‧‧‧Optical film

12‧‧‧Transparent substrate

13‧‧‧Optical layer

14‧‧‧Concave and convex shape

100‧‧‧Penetration image clarity measuring device

101‧‧‧Light source

102‧‧‧Slit

103、104‧‧‧lens

105‧‧‧Light comb

106‧‧‧Receiver

30‧‧‧Display device with touch panel

31‧‧‧Optical Film

32‧‧‧Transparent substrate

33‧‧‧Optical layer

34‧‧‧Concave and convex shape

35‧‧‧Touch Panel

43‧‧‧Optical layer

44‧‧‧Concave and convex shape

45‧‧‧Touch Panel

46‧‧‧Gap

Fig. 1 is a cross-sectional view schematically showing the optical film of the present invention.

FIG. 2 is a schematic diagram showing the situation of measuring the clarity of the through image of the optical film by using the device for measuring through image clarity.

FIG. 3 is a cross-sectional view schematically showing a display device with a touch panel of the present invention.

4 is a schematic diagram showing how incident light is reflected in the second form of the display device with touch panel of the present invention.

Figure 5 shows the surface profile of the optical film of the present invention.

The content of the present invention is illustrated by the following embodiments, but the content of the present invention is not limited to these implementations. Unless otherwise specified, "parts" and "%" are quality standards.

(Example 1)

(Production of optical film)

Prepare a translucent substrate (cellulose triacetate film, thickness 40μm, manufactured by Konica Minolta Co., KC4UAW), and coat the optical layer composition of the following composition on one side of the translucent substrate to form Coating film.

Then, for the formed coating film, dry air at 50°C was circulated at a flow rate of 0.2m/s for 30 seconds, and then dry air at 70°C was circulated at a flow rate of 10m/s for 30 seconds to dry it. The solvent in the coating film is evaporated.

Thereafter, using an ultraviolet irradiation device (manufactured by Fusion UV Systems Japan, light source H BULB), under a nitrogen atmosphere (oxygen concentration of 200 ppm or less), ultraviolet rays are irradiated so that the cumulative light quantity becomes 100 mJ/cm ^{2 to} harden the coating film. An optical layer with a thickness of 5.0 μm (when cured) was formed to produce an optical film.

(Composition for optical layer)

Silicon dioxide particles (fumigated silicon dioxide treated with octyl silane, average primary particle size 12nm, manufactured by Japan Aerosil Corporation) 0.5 parts by mass

Neopentylerythritol tetraacrylate (PETTA) (product name "PETA", manufactured by Daicel-Cytec) 50 parts by mass

Amino acrylate (product name "V-4000BA", manufactured by DIC Corporation) 50 parts by mass

Polymerization initiator (Irgacure 184, manufactured by BASF Japan) 5 parts by mass

Polyether modified polysiloxane (product name "TSF4460", manufactured by Momentive Performance Materials) 0.025 parts by mass

115 parts by mass of toluene

45 parts by mass of isopropanol

15 parts by mass of cyclohexanone

(Example 2)

The curing conditions of the coating film were set to irradiate ultraviolet rays so that the cumulative light amount became 50 mJ/cm ^{2 to} cure the coating film. Except for this, the uneven layer was formed in the same manner as the optical layer of Example 1.

The composition for a low refractive index layer shown below is applied to the surface of the formed uneven layer to form a coating film.

Then, for the formed coating film, 40°C dry air was circulated at a flow rate of 0.2m/s for 15 seconds, and then 40°C dry air was circulated at a flow rate of 10m/s for 30 seconds to dry it. The solvent in the coating film is evaporated.

Thereafter, using an ultraviolet irradiation device (manufactured by Fusion UV Systems Japan, light source H BULB), under a nitrogen atmosphere (oxygen concentration of 200 ppm or less), ultraviolet rays are irradiated so that the cumulative light quantity becomes 100 mJ/cm ^{2 to} harden the coating film. A low refractive index layer with a thickness of 0.1 μm (when cured) is formed, and an optical layer having a concavo-convex layer and a low-refractive index layer laminated on the concavo-convex layer is formed. In this way, the optical film of Example 2 was produced.

(Composition for low refractive index layer)

Hollow silica particles (average particle size 60nm) 125 parts by mass (100% conversion value of solid content)

Neopentylerythritol triacrylate (PETA) (product name: PETIA, manufactured by Daicel-Cytec) 20 parts by mass

Fluoropolymer (product name "Opstar JN35", manufactured by JSR Corporation) 80 parts by mass (100% conversion value of solid content)

Polymerization initiator (Irgacure 127; manufactured by BASF Japan) 7 parts by mass

Modified silicone oil (X22164E; made by Shin-Etsu Chemical Co., Ltd.) 5 parts by mass

Methyl isobutyl ketone (MIBK) 5,300 parts by mass

2200 parts by mass of propylene glycol monomethyl ether acetate (PGMEA)

(Example 3)

The blending amount of silica fine particles in the composition for the optical layer was set to 0.8 parts by mass, and the drying conditions of the coating film were set to circulate dry air at 70°C for 15 seconds at a flow rate of 1.0m/s, and then to 10m An optical film was produced in the same manner as in Example 1 except that dry air at 70°C was circulated for 30 seconds at a flow rate of /s.

(Example 4)

The optical film was produced in the same manner as in Example 1 except that the thickness when the optical layer was cured was 4.5 μm.

(Example 5)

Set the drying conditions of the coating film to circulate dry air at 70°C for 15 seconds at a flow rate of 1.0m/s, and then circulate dry air at 70°C for 30 seconds at a flow rate of 10m/s to harden the optical layer The thickness at the time was set to 4.5 μm, except for this, an optical film was produced in the same manner as in Example 3.

(Example 6)

The composition for the optical layer contains 1.0 part by mass of organic particles (acrylic-styrene copolymer particles, average particle diameter: 2.0 μm, refractive index: 1.55, manufactured by Sekisui Chemical Industry Co., Ltd.), and the drying conditions of the coating film are set to After circulating dry air at 70°C for 15 seconds at a flow rate of 1.0m/s, and then circulating dry air at 70°C for 30 seconds at a flow rate of 10m/s, an optical film was produced in the same manner as in Example 1, except that .

(Comparative example 1)

The blending amount of the silica fine particles in the optical layer composition is 1.0 part by mass, and it contains organic particles (acrylic-styrene copolymer particles, average particle size: 2.0 μm, refractive index: 1.55, Sekisui Chemical Industry Co., Ltd. (Manufactured by the company) 3.0 parts by mass. Set the drying conditions of the coating film to circulate dry air at 70°C for 15 seconds at a flow rate of 0.2m/s, and then circulate dry air at 70°C for 30 seconds at a flow rate of 10m/s. Except that the thickness of the optical layer at the time of hardening was 4.0 μm, an optical film was produced in the same manner as in Example 1.

(Comparative example 2)

The optical film was produced in the same manner as in Example 1, except that silica fine particles were not blended in the composition for the optical layer.

<Evaluation of anti-reflection>

The optical films produced in the respective examples and comparative examples were attached to the black acrylic board in such a way that the uneven surface becomes the surface through the transparent adhesive. In a bright room environment, from a distance of about 2m away from the room, the sample was visually inspected and evaluated according to the following criteria to evaluate whether the sample obtained the anti-reflective property of "I don't mind the degree of reflection of the observer and the observer's background".

○: Do not mind the reflection

×: The reflection is clearly visible

<Presence of Watermark>

The optical films produced in the respective examples and comparative examples were attached to the black acrylic board in such a way that the uneven surface becomes the surface through the transparent adhesive.

In addition, tape was attached to both ends of a glass plate having a thickness of 0.7 mm and a size of 10 cm×10 cm. Then, with the optical film and the glass plate separated, the tape-attached surface of the glass plate is arranged to face the optical film. The air gap between the surface of the optical film and the glass plate is 0.1mm. Then, while pressing the glass plate with a finger, irradiate light from the sodium lamp placed on the glass to investigate whether the watermark is confirmed. The evaluation criteria are as follows. The results are shown in Table 1.

◎: The watermark is not confirmed.

○: Some watermarks are observed but the level is no problem.

×: The watermark is clearly confirmed.

<Determination of the clarity of the penetrating image>

For each optical film obtained in the examples and comparative examples, the clarity of the penetration image was measured in the following manner. The results are shown in Table 1.

First, the image clarity measuring device (model: ICM-1T, manufactured by SUGA Test Instruments) is prepared.

Then, the optical films of the Examples and Comparative Examples were set so that the side of the triacetyl cellulose resin film became the light source side of the image clarity measuring device, according to the image clarity of the penetration method using JIS K7374 The measurement method determines the clarity of the penetrating image. As the optical comb, one having a width of 0.125 mm and a width of 0.25 mm was used. Then, obtain the clearness of the penetration image measured by a light comb with a width of 0.25 mm The difference between the sharpness (C(0.25)) and the penetration image sharpness (C(0.125)) measured by a light comb with a width of 0.125mm (C(0.25)-C(0.125)). Furthermore, for reference, an optical comb with a width of 0.5 mm, a width of 1.0 mm, and a width of 2.0 mm was used to measure the clarity of the transmission image of each optical film of the examples and comparative examples in the same manner as described above.

<Glare Evaluation (1)>

For each of the optical films obtained in the Examples and Comparative Examples, the surface of the optical film without an optical layer and the glass surface of the 350ppi black matrix (glass thickness 0.7mm) without matrix formation were bonded with an adhesive. For the sample obtained in this way, a white surface light source (Lightbox manufactured by HAKUBA, average brightness 1000 cd/m ² ) is set on the side of the black matrix to simulate glare. It was taken from the optical film side with a CCD camera (KP-M1, C-type mounting adapter, extension tube: PK-11A Nikon, camera lens: 50mm, F1.4s NIKKOR). The distance between the CCD camera and the optical film is set to 250mm, and the focus of the CCD camera is adjusted by aligning the optical film. The image taken by the CCD camera was put into a personal computer, and image processing software (ImagePro Plusver.6.2; manufactured by Media Cybernetics) was used for analysis in the following manner. First, select a 200×160 pixel evaluation part from the inserted image, and convert the evaluation part into 16bit grayscale.

Secondly, select the low-pass filter from the enhanced tab of the filter command, and start the filter under the conditions of 3×3, order 3, and intensity 10. In this way, components originating from the black matrix pattern are removed.

Secondly, choose flattening, and perform shadow correction on the condition of dark background and target width 10.

Secondly, use the contrast enhancement command to set contrast: 96 and brightness: 48 for contrast enhancement. The obtained image is converted into 8bit gray scale, and the deviation of the value of each pixel is calculated for the 150×110 pixels among them as the standard deviation value, thereby digitizing the glare. Dazzle after digitization The smaller the light value, the less glare. The results are shown in Table 1.

<Glare Evaluation (2)>

For each optical film obtained in Examples and Comparative Examples, the glare was evaluated as follows. Set a light box (white surface light source) with a brightness of 1500cd/m ² , a 350ppi black matrix glass, and an optical film in order to overlap from the bottom to the top. The distance from about 30cm is from top to bottom, to the left and right. There are 15 people The subjects were visually evaluated. Determine whether you mind glare, and evaluate with the following criteria. The results are shown in Table 1.

◎: 13 or more people who answered well

○: 10-12 people who answered well

△: 7-9 people who answered well

×: 6 people or less who answered well

<Measurement of total haze, internal haze, and surface haze>

For each optical film obtained in the foregoing Examples and Comparative Examples, the total haze, internal haze, and surface haze were measured as follows. The results are shown in Table 2.

First, a haze meter (HM-150, manufactured by Murakami Color Research Institute) was used to measure the total haze value of the optical film in accordance with JIS K7136.

After that, a triacetyl cellulose substrate (manufactured by Konica Minolta, KC4UAW) was attached to the surface of the optical layer via a transparent optical adhesive layer. Thereby, the uneven shape of the uneven surface of the optical layer is crushed, and the surface of the optical film becomes flat. In this state, using a haze meter (HM-150, manufactured by Murakami Color Research Institute), the haze value was measured in accordance with JIS K7136 to obtain the internal haze value. Then, the surface haze value is obtained by subtracting the internal haze value from the total haze value.

<Measurement of three-dimensional average tilt angle θ a _3D >

For the surface of each optical film obtained in the Examples and Comparative Examples, the three-dimensional average tilt angle θ a _{3D was} measured in the following manner. The results are shown in Table 2.

The surface of each optical film on the opposite side to the surface on which the unevenness is formed is attached to a glass plate via a transparent adhesive to prepare a sample. A white interference microscope (New View 7300, manufactured by Zygo) is used under the following conditions Measurement and analysis of the surface shape of optical film. Furthermore, the measurement and analysis soft system uses MetroPro ver8.3.2. Microscope Application.

(Measurement conditions)

Objective lens: 50 times

Zoom: 1 times

Measuring area: 545μm×545μm

Resolution (every 1 point interval): 0.44μm

(Analysis conditions)

Removed: Plane

Filter: High Pass

FilterType: GaussSpline

Low wavelength: 250μm

High wavelength: 3μm

Remove spikes: on

Spike Height (xRMS): 2.5

Furthermore, Low wavelength corresponds to the critical value λc in the roughness parameter. Secondly, use the aforementioned analysis software (MetroPro ver8.3.2-Microscope Application) to display "Ra" on the Slope Mag Map screen, and set its value to θ a _{3D of the} optical film.

<Measurement of Smp, Ra, Rz>

Using the surface shape data obtained when calculating the above-mentioned three-dimensional average inclination angle θ a _3D and the same analysis conditions, "Ra" and "SRz" are displayed on the Surface Map screen, and the values of each are set to the Ra and Rz of the optical film .

Secondly, display the "Save Data" button on the Surface Map screen to save the 3D surface roughness data after analysis. Then, use Advanced Texture Application to read the above saved data and apply the following analysis conditions.

(Analysis conditions)

High FFT Filter: off

Low FFT Filter: off

Remove: Plane

Next, display the Peak/Valleys screen, and count the number of peaks according to "Peaks Stats". Among them, in order to exclude insignificant peaks, peaks with an area of 1/10000 or more of the area of a circle (125 μm×125 μm×π) with the Low wavelength as the diameter and a height of 1/10 or more of Rtm are counted. Furthermore, Rtm can be read from the "Roughness/Waviness Map" screen, which represents the average value of the maximum height of each area when the entire measurement area is divided into 3×3. Then, Smp is calculated based on the following formula using the above-mentioned method. The results are shown in Table 2.

As shown in Table 1 and Table 2, the optical films of the examples have excellent anti-reflective properties, watermarks, and glare (1) and (2). In addition, the total haze, internal haze, and surface haze are excellent The values are low enough.

On the other hand, regarding the optical film of Comparative Example 1, the difference between the value of C (0.25) and the value of C (0.125) is small, the uneven shape of the optical layer surface is gentle, and the evaluation of glare is poor. Moreover, regarding the optical film of Comparative Example 2, the value of C (0.125) was large, and the difference between the value of C (0.25) and the value of C (0.125) was small, and the evaluation of anti-reflective properties and watermark was poor.

<Half width of surface height distribution>

For each optical film obtained in the Examples and Comparative Examples, the surface on the opposite side to the surface on which the optical layer was formed was attached to a glass plate via a transparent adhesive to prepare samples, and a white interference microscope (New View 7300, Zygo Company), the surface profile of the optical film was obtained under the following conditions.

Furthermore, the measurement and analysis soft system uses MetroPro ver8.3.2. Microscope Application.

(Measurement conditions)

Objective lens: 10 times

Zoom: 1 times

Measuring area: 2.71mm×2.71mm

Resolution (every 1 point interval): 2.18μm

(Analysis conditions)

Removed: None

Filter: BandPass

FilterType: GaussSpline

Low wavelength: 800μm

High wavelength: 25μm

Remove spikes: on

Spike Height (xRMS): 2.5

Furthermore, Low wavelength is the wavelength of the long-wavelength cut-off filter, and High wavelength is equivalent to the wavelength of the short-wavelength cut-off filter.

Secondly, use the aforementioned analysis software (MetroPro ver8.3.2-Microscope Application) to display the Surface Map screen, and display the histogram in such a way that the interval width becomes about 20nm in the aforementioned screen to obtain the histogram data of the surface height distribution.

According to the obtained histogram data, read the width of the distribution at the half height of the peak position and set it as the half width of the surface height distribution.

Furthermore, when calculating the half-value width, an approximate curve obtained by linear interpolation of the value of each level of the obtained histogram data is made, and calculated based on the curve.

<Average curvature of surface unevenness>

According to the surface profile obtained in the same way as the above, the curvature is calculated according to the above formula and the average value of the curvature of all points is calculated for the x direction from each point and 3 points before and after it, thereby Calculate the average curvature of the uneven surface.

For the optical film produced in each embodiment and comparative example, the half-value width of the surface height distribution, the average curvature of the surface unevenness, the presence or absence of watermark, glare evaluation (1), (2), total haze, internal haze The results of surface haze, three-dimensional average inclination angle θ a3D, "Smp", "Ra" and "Rz" are shown in Table 3.

As shown in Table 3, regarding the optical films of Examples 1 to 6, the watermark and glare (1) and (2) are excellent in each evaluation, and the values of total haze, internal haze, and surface haze are also sufficiently low .

On the other hand, regarding the optical film of Comparative Example 1, the average curvature of the uneven surface shape was large, the lens effect caused by the uneven surface shape became large, and the evaluation of glare was poor.

In addition, regarding the optical film of Comparative Example 2, the half-value width of the surface height distribution was small, and the evaluation of the watermark was poor.

[Industrial availability]

Since the optical film of the present invention is composed of the above-mentioned structure, reflection or Newton's ring can be suppressed, and the generation of glare can be sufficiently suppressed, and a high-quality display image can be obtained. In addition, since the display device with a touch panel of the present invention is constituted by the above-mentioned structure, the generation of watermarks and glare can be sufficiently suppressed, and high-quality display images can be obtained.

Therefore, the display device with touch panel of the present invention can be preferably applied to cathode ray tube display device (CRT), liquid crystal display (LCD), plasma display (PDP), electroluminescence display (ELD), field emission Display (FED), electronic paper, tablet PC, etc.

Claims (8)

An optical film having the following composition: an optical layer having an uneven surface is laminated on a translucent substrate, characterized in that the half-value width of the surface height distribution of the optical film is 200 nm or more, and the surface is uneven The average curvature is 0.05 mm ^-1 or more and 0.30 mm ^-1 or less. For example, the optical film of the first item in the scope of the patent application has a total haze value of 0% or more and 5% or less, and the internal haze value of the above-mentioned optical film is 0% or more and 5% or less. For example, the optical film of item 1 or 2 in the scope of patent application, wherein the optical layer contains a binder resin and fine particles. For example, the optical film of item 3 in the scope of patent application, wherein the particles are inorganic oxide particles. For example, the optical film of item 4 in the scope of patent application, wherein the average primary particle size of the inorganic oxide fine particles is 1 nm or more and 100 nm or less. For example, the optical film of item 4 in the scope of patent application, wherein the inorganic oxide particles are inorganic oxide particles whose surface has been hydrophobized. For example, the optical film of item 5 of the scope of patent application, wherein the inorganic oxide particles are inorganic oxide particles whose surface has been hydrophobized. A display device with a touch panel, which has a structure in which the optical film of items 1, 2, 3, 4, 5, 6 or 7 of the scope of patent application and the touch panel are arranged oppositely, and the above-mentioned optical film The above-mentioned touch panel and the above-mentioned touch panel are arranged to face each other in such a way that the optical layer of the above-mentioned optical film faces the above-mentioned touch panel in a state of mutual clearance.

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