JP6666871B2 - Method for producing anti-glare film, anti-glare film, coating liquid, polarizing plate and image display device - Google Patents

Description

The present invention relates to a method for producing an antiglare film, an antiglare film, a coating solution, a polarizing plate, and an image display device.

The anti-glare film is used to reflect or reflect external light in various image display devices such as a cathode ray tube display (CRT), a liquid crystal display (LCD), a plasma display panel (PDP), and an electroluminescence display (ELD). It is arranged on the display surface in order to prevent a decrease in contrast due to reflection of light. Various proposals have been made for the anti-glare film to achieve appropriate anti-glare properties and improvement of other physical properties.

For example, when a fine particle-containing paint for forming an antiglare layer is applied on a substrate and dried, a convection generated when the solvent is volatilized to form a Benard cell structure on the surface of the coating layer, thereby smoothing the surface shape. There has been a proposal to control such a device (for example, see Patent Document 1).

In addition, there is a proposal that display characteristics are improved by forming a three-dimensional three-dimensional structure aggregated portion using fine particles (for example, see Patent Document 2). Patent Literature 2 has a two-layer structure in which a surface adjustment layer is formed on the surface of the antiglare layer in order to smooth the unevenness of the antiglare layer.

JP 2008-257255 A Japanese Patent No. 4641846

In Patent Document 1 described above, by utilizing fine particles assembling in a planar shape, the surface of the antiglare layer is made to have a gentle uneven structure by forming a Benard cell, thereby achieving both antiglare property and contrast. However, in order to form a desired shape using a Benard cell, it is necessary to control the convection generated when the solvent evaporates during drying, as described above. Condition control is required.

On the other hand, Patent Literature 2 has a two-layer structure in which a surface adjustment layer is further formed on the surface of an antiglare layer formed by aggregating particles in order to form a gentle uneven structure on the surface of the antiglare layer. For this reason, the number of manufacturing steps is large and productivity is poor as compared with the case where the antiglare layer has a single-layer structure.

Therefore, the present inventors formed an anti-glare layer having a smooth uneven surface structure by aggregating particles, and formed the anti-glare layer into one layer instead of a two-layer structure in consideration of productivity and cost. We have started new development to form a structure. The company has been working diligently to find that defects can be found on the surface of the anti-glare film in a one-layer anti-glare layer formed by agglomeration of particles, through visual inspection (visual observation with a fluorescent lamp in a dark room). Faced with new challenges. The anti-glare film having this appearance defect cannot be used as a product and is discarded. Further, for example, when an appearance defect is found in a sheet-like polarizing plate using an antiglare film, the appearance defect is 1%.
Even at the location, the polarizing plate itself must be discarded. For this reason, especially for a polarizing plate for a large liquid crystal panel, the disposal area for the appearance defect becomes large, and the yield becomes extremely poor.

As a result of repeated investigations on the mechanism of the appearance defect, it was found that the cause was caused by protrusions (also referred to as “bubbles”) generated on the surface of the antiglare layer. It is considered that the appearance defects of the projections are particularly prominent when an antiglare layer having a gentle surface shape is formed. That is, in the case of an antiglare film having a rough anti-glare layer having a rough surface (having a high arithmetic average surface roughness Ra) and having a high anti-glare property, even if the anti-glare film has these projections, light diffusion due to the anti-glare effect It is considered that this did not appear as a noticeable appearance defect.

The present inventors cross-sectioned this protruding object for further study, and
Observation by SEM) revealed that the presence of a plurality of particles overlapping in the thickness direction of the anti-glare layer was a factor of generation of the projections.

In order to eliminate the protrusions from the anti-glare layer, it is conceivable to reduce the number of particles used or adopt particles having a small particle size. However, in that case, it has been difficult to form a desired smooth surface unevenness that achieves both anti-glare properties and prevention of white blur. Further, it is conceivable to increase the thickness of the antiglare layer with respect to the particles to prevent the particles from overlapping in the thickness direction. However, in such a case, a problem such as curling of the film occurs.

In Patent Literature 2, particles having excellent aggregation characteristics are used, and a desired surface shape is formed by utilizing the aggregation effect of the particles. Specifically, for example, depending on the polarity of the solvent,
Particles having a hydrophobic or hydrophilic group introduced on the surface are employed. As described above, by using particles having excellent aggregation characteristics, it is possible to relatively easily design the surface shape by utilizing the aggregation of the particles. However, since the above-mentioned particles are designed to have a hydrophobic group or a hydrophilic group introduced on the surface, it is difficult to stably produce the same characteristics, and the aggregation state of the coating liquid affects the composition of the coating liquid. Easy to receive. Therefore, it is difficult to stably form a surface shape even when precise production conditions are controlled in the coating / drying process.

Further, the particles in the coating liquid swell with the solvent. For this reason, the aggregation characteristics of the particles are changing with time, and after adjusting the coating liquid, depending on the time before entering the actual manufacturing process, the swelling state of the particles in the coating liquid changes, and as a result, The aggregation state is affected, and it is difficult to stably form the surface shape.

The present invention is a manufacturing method for forming an anti-glare film having excellent display characteristics, which has both anti-glare properties and prevention of white blur, by utilizing agglomeration of particles. The formation of protrusions on the surface of the glare layer can be prevented, and the aggregation state of the particles can be controlled without depending on the aggregation characteristics of the particles, thereby forming an antiglare layer having a desired surface unevenness. An object of the present invention is to provide a method for producing an antiglare film that can be used.

In order to achieve the above object, a method for producing an anti-glare film of the present invention comprises applying a coating liquid to at least one surface of a light-transmitting substrate, and curing the coating liquid to form an anti-glare layer. Wherein the coating liquid contains a resin, particles, a thixotropy-imparting agent and a solvent, and satisfies at least one of the following conditions (I) and (II): And a step of causing the coating liquid applied to the translucent substrate to shear.

(I) In a linear approximation between the amount of the thixotropy-imparting agent and the Ti value in a range where the Ti value defined by the following formula (A) is 1.2 to 3.5, the contribution ratio R ² is 0.95 or more.
(II) When the Ti value defined by the following formula (A) is in the range of 1.2 to 3.5, a quadratic polynomial approximation y = the addition amount x of the thixotropy-imparting agent and the Ti value y = The quadratic coefficient a at ax ² + bx + c is a negative value.

Ti value = β1 / β2 (A)

In the above formula (A),
β1: viscosity at a shear rate of 20 (1 / s) β2: viscosity at a shear rate of 200 (1 / s)

Further, another method for producing an anti-glare film of the present invention is a method for forming an anti-glare layer by coating a coating liquid on at least one surface of a light-transmitting substrate and curing the coating liquid. A method for producing a glare film, wherein a resin, particles, a thixotropy-imparting agent and a solvent are used as the coating liquid, and the coating liquid applied to the light-transmitting substrate is caused to shear. And a step of causing the particles to be unevenly distributed by the shearing to form the surface shape of the antiglare layer.

The anti-glare film of the present invention is characterized by being an anti-glare film produced by the method for producing an anti-glare film of the present invention.

The coating liquid of the present invention is a coating liquid for forming the anti-glare layer in an anti-glare film having an anti-glare layer on at least one surface of a light-transmitting substrate, and is provided with a resin, particles, and thixotropy. And at least one of the following conditions (I) and (II).
(I) In a linear approximation between the amount of the thixotropy-imparting agent and the Ti value in a range where the Ti value defined by the following formula (A) is 1.2 to 3.5, the contribution ratio R ² is 0.95 or more.
(II) When the Ti value defined by the following formula (A) is in the range of 1.2 to 3.5, a quadratic polynomial approximation y = the addition amount x of the thixotropy-imparting agent and the Ti value y = The quadratic coefficient a at ax ² + bx + c is a negative value.

Ti value = β1 / β2 (A)

In the above formula (A),
β1: viscosity at a shear rate of 20 (1 / s) β2: viscosity at a shear rate of 200 (1 / s)

The polarizing plate of the present invention has a polarizer and the anti-glare film of the present invention.

  An image display device according to the present invention includes the anti-glare film according to the present invention.

Alternatively, the image display device of the present invention is an image display device including a polarizing plate, wherein the polarizing plate is the polarizing plate of the present invention.

The present invention is a manufacturing method for forming an anti-glare film having excellent display characteristics, which has both anti-glare properties and prevention of white blur, by utilizing agglomeration of particles. ADVANTAGE OF THE INVENTION According to this invention, generation | occurrence | production of the projection-like thing of the glare-proof layer surface which becomes an external appearance defect can be prevented. Further, the aggregation state of the particles can be controlled without depending on the aggregation characteristics of the particles, whereby an antiglare layer having a desired surface unevenness can be formed.

Specifically, according to the present invention, since the thixotropy-imparting agent is contained in the coating liquid containing the particles, the particles are excessively aggregated in the thickness direction of the anti-glare layer due to the effect of preventing the thixotropy-imparting agent from settling. As a result, it is possible to prevent the occurrence of protrusions on the surface of the anti-glare layer, which may be a defect in appearance. Furthermore, in the present invention, a coating liquid containing a thixotropy-imparting agent is used, and the particles are unevenly distributed due to the aggregation action of the thixotropy-imparting agent by causing shearing in the coating liquid, so that the surface shape of the antiglare layer is reduced. Form. Thus, in the present invention, in order to unevenly distribute particles,
Since the coagulation action of the thixotropic agent by the shearing of the coating liquid is used, the coagulation state of the particles can be controlled without depending on the coagulation characteristics of the particles.

FIG. 1A is a graph illustrating the relationship between the amount of a thixotropic agent and the Ti value. FIG. 1B is a graph showing another example of the relationship between the amount of the thixotropic agent and the Ti value. FIG. 2 is a schematic diagram showing the relationship between the amount of the thixotropy-imparting agent added and the assumed distribution state of the thixotropy-imparting agent. FIG. 3 is a schematic diagram illustrating a method for calculating the shear rate V of the coating film. FIG. 4A is a schematic diagram illustrating an example of a method of adjusting the shear rate V of the coating film in the production method of the present invention, and FIG. FIG. 9 is a schematic view showing another example of the adjustment method of FIG. FIG. 5 is a schematic diagram illustrating an example in which the shear speed V changes depending on the shear holding time t. FIG. 6 is a schematic diagram illustrating the definition of the height of the convex portion. FIG. 7A is a schematic diagram illustrating a configuration of an example of the antiglare film of the present invention. FIG. 7B is a schematic diagram illustrating a configuration of an example of an anti-glare film in which the anti-glare layer does not include a thixotropic agent, which is different from the present invention. FIG. 8A is a schematic explanatory view schematically illustrating a mechanism presumed regarding aggregation of particles in the antiglare film of the present invention. FIG. 8B is a schematic explanatory diagram schematically illustrating a mechanism presumed regarding aggregation of particles in an antiglare film in which an antiglare layer does not include a thixotropic agent, which is different from the present invention. FIG. 9 is a schematic diagram illustrating an example of the definition of the thickness direction and the plane direction of the antiglare layer in the antiglare film of the present invention. FIG. 10A is a schematic explanatory view schematically illustrating a mechanism presumed regarding aggregation of particles when a permeable layer is formed in the antiglare film of the present invention. FIG. 10B is a schematic explanation for schematically explaining a mechanism presumed regarding aggregation of particles in a case where a penetrating layer is formed in an antiglare film in which an antiglare layer does not contain a thixotropic agent, which is different from the present invention. FIG. FIG. 11 is a graph showing the relationship between the addition amount of the thixotropy-imparting agent and the Ti value in Examples and Comparative Examples, and a linear approximation straight line between the addition amount of the thixotropy-imparting agent and the Ti value was given. Things. FIG. 12 is a graph showing the relationship between the amount of addition of the thixotropy-imparting agent and the Ti value in Examples and Comparative Examples. Is given. FIG. 13A is an optical microscope (semi-transmission mode) photograph of the surface of the antiglare layer of the antiglare film in Example 1. In FIG. 13A, the scale is 50 μm. FIG. 13B is a schematic diagram showing the distribution of particles observed in the photograph of FIG. FIG. 14A is an optical microscope (semi-transmissive mode) photograph of the anti-glare layer surface of the anti-glare film in Comparative Example 4. In FIG. 14A, the scale is 50 μm. FIG. 14B is a schematic diagram showing the distribution of particles observed in the photograph of FIG.

The present invention is a method for producing an antiglare film, in which a coating liquid is applied to at least one surface of a translucent substrate, and the coating liquid is cured to form an antiglare layer. And the antiglare film which has the said effect can be manufactured by using the coating liquid shown below and causing the coating liquid applied to the translucent substrate to shear.

Hereinafter, (1) the action of the thixotropic agent contained in the coating liquid, (2) the conditions of the coating liquid to be used, and (3) the step of causing the coating liquid to shear will be described in detail. However, the present invention is not limited by the following description.

<(1) Action of thixotropic agent contained in coating liquid>
The coating liquid used in the present invention contains a resin, particles, a thixotropic agent and a solvent. When the coating liquid contains a thixotropy-imparting agent having an effect of preventing sedimentation, it is possible to prevent the appearance of projections on the surface of the antiglare layer, which is a defect in appearance.

FIG. 7A schematically shows a configuration of an example of the antiglare film obtained by the production method of the present invention. As shown in the schematic diagram of FIG. 7A, in the antiglare layer 11, the particles 12 and the thixotropy-imparting agent 13 are aggregated to form the convex portions 14 on the surface of the antiglare layer 11. The aggregation state of the particles 12 and the thixotropy-imparting agent 13 is not particularly limited, but the thixotropy-imparting agent 13 tends to be present at least around the particles 12. In the aggregation portion forming the convex portion 14, the particles 12 exist in a state where a plurality of particles 12 gather in the surface direction of the antiglare layer 11. As a result,
The convex portion 14 has a gentle shape. On the other hand, when the anti-glare layer does not contain the thixotropic agent, as shown in the schematic diagram of FIG.
2 are aggregated not only in the surface direction of the antiglare layer 11 but also in the thickness direction thereof, and the convex portions 14a and 14b are formed. Depending on the degree of agglomeration of the particles 12 in the plane direction and in the thickness direction, for example, a convex portion such as the convex portion 14a and the convex portion 14b is formed on the surface of the anti-glare layer 11, resulting in poor appearance and defects. White blur is likely to occur.

It is presumed that the convex portion having the above-described shape is formed by the following mechanism. However, the present invention is not limited or limited by this inference. The following speculation is that the coating liquid containing the solvent (the anti-glare layer forming material) is coated on a light-transmitting base material to form a coating film,
The case where the antiglare layer is formed will be described as an example.

FIG. 8A is a schematic view of a state in which a cross section in the thickness direction of the antiglare film of the present invention is viewed from the side in order to explain the mechanism of aggregation in the antiglare layer in the antiglare film of the present invention. FIG. FIG. 8B is a schematic explanatory view schematically showing an aggregation state of particles different from that of the present invention. 8A and 8B, (a) shows a state in which a coating film is formed by applying the antiglare layer forming material containing a solvent to a translucent substrate or the like, and (b) shows a coating film. Shows a state in which the anti-glare layer is formed by removing the solvent from.

In the case of FIG. 8A, the anti-glare layer is formed using an anti-glare layer forming material containing a resin, particles, a thixotropy-imparting agent and a solvent, whereas in the case of FIG. 8B, the anti-glare layer forming material is formed of a thixotropy. Contains no imparting agent. In FIG. 8A, illustration of the thixotropy-imparting agent is omitted in consideration of legibility of the drawing.

Hereinafter, with reference to FIG. 8A, a mechanism for forming the gentle convex portion as described above will be described. However, this mechanism is presumed and does not limit the present invention. That is, as shown in FIGS. 8A (a) and 8 (b), by removing the solvent contained in the coating film, the thickness of the coating film shrinks (decreases). Since the lower surface side (back surface side) of the coating film is stopped by the translucent substrate, the contraction of the coating film occurs from the upper surface side (front surface side) of the coating film. In FIG. 8A (a), particles (for example, particles 1, 4 and 5) existing in a portion where the thickness of the coating film is reduced
Tends to move to the lower surface side of the coating film due to this decrease in film thickness. On the other hand, particles (for example, particles 2, particles 3, and particles 6) which are not affected by the film thickness change or exist at relatively low positions near the lower surface which are not easily affected by the film thickness change are included in the antiglare layer forming material. Due to the sedimentation preventing effect (thixotropic effect) of the thixotropy-imparting agent, movement to the lower surface side is suppressed (for example, it does not move to the lower surface side from the two-dot chain line 10). For this reason, even if the coating film shrinks, the particles (particles 2, 3, and 6) on the lower surface side move toward the particles (particles 2, 3, and 6) from the surface side.
Due to the particles 1, the particles 4 and the particles 5), they are not pushed downward (to the rear side), but remain almost at the position. Since the particles (particle 2, particle 3 and particle 6) on the lower surface side substantially stay at that position, the particles (particle 1, particle 4 and particle 5) moving from the surface side are the particles on the lower surface side. The particles move to the next to the non-existent particles on the lower surface side (in the surface direction of the coating film). Thus, in the anti-glare film of the present invention, it is presumed that the particles are present (distributed) in the anti-glare layer in a state where a plurality of particles are gathered in the surface direction of the anti-glare layer.

As described above, in the anti-glare layer, the particles aggregate in the surface direction of the anti-glare layer,
The surface shape of the anti-glare layer is formed. In addition, since the anti-glare layer contains a thixotropy-imparting agent having an anti-settling effect, the particles are prevented from excessively aggregating in the thickness direction of the anti-glare layer. As a result, it is possible to prevent the occurrence of projections on the surface of the antiglare layer, which are defects in appearance.

On the other hand, when the anti-glare layer forming material does not contain a thixotropy-imparting agent, the particles do not have the effect of preventing sedimentation of the thixotropy-imparting agent. For this reason, due to the contraction of the film thickness, FIG.
As shown in (a), the particles on the lower surface side (particle 2, particle 3 and particle 6) together with the other particles on the upper surface side (particle 1, particle 4 and particle 5) are on the transparent substrate surface side. Settle and gather (for example,
They move to the lower side from the two-dot chain line 10 and gather). For this reason, as shown in FIG. 8B (b), a portion where the particles excessively aggregate in the thickness direction of the antiglare layer may occur. Then, it is presumed that this portion becomes a projection on the surface of the antiglare layer which becomes a defect in appearance.

In addition, the anti-glare film of the present invention, the convex portion has a gentle shape as described above, as long as it can prevent the occurrence of protrusions on the surface of the anti-glare layer that becomes a defect in appearance, for example, Some of the particles may be present at positions directly or indirectly overlapping in the thickness direction of the antiglare layer.
When the overlap of the particles is represented by the number, the “thickness direction” of the antiglare layer is, for example, as shown in the schematic diagram of FIG. Angle to the surface direction)
Shows a direction within the range of 45 to 135 degrees. And, for example, the thickness (d) of the antiglare layer is 3 to
The particle diameter (D) of the particles is in the range of 2.5 to 10 μm, and the relationship between the thickness (d) and the particle diameter (D) is 0.3 In the range of ≦ D / d ≦ 0.9, for example, the overlap of the particles in the thickness direction of the antiglare layer is preferably 4 or less, more preferably 3 or less.

Next, referring to the schematic explanatory views of FIGS. 10A and 10B, regarding the case where the above-described penetrating layer is formed between the light-transmitting substrate and the anti-glare layer in the mechanism assumed above. Will be explained. FIG. 10A is a schematic explanatory view of the anti-glare film of the present invention as described with reference to FIG. 8A, and FIG. 10B is a view similar to that described with reference to FIG. 8B.
It is a schematic explanatory drawing about the anti-glare film different from this invention. 10A and 10B
In (a), (a) shows a state in which the solvent is removed from the coating film to form the antiglare layer,
b) shows a state in which the solvent is removed from the coating film to form an antiglare layer. 10A and 10B
In (1), the permeation layer is provided with parallel oblique lines. The present invention is not limited or limited by the following description.

The case of the antiglare film of the present invention will be described with reference to FIG. 10A. FIG. 10A (a
As shown in (b) and (b), by removing the solvent contained in the coating film, the thickness of the coating film shrinks (decreases), and an antiglare layer is formed. Further, with the formation of the anti-glare layer, the resin contained in the anti-glare layer forming material penetrates into the translucent substrate, so that a penetrating layer is formed between the anti-glare layer and the translucent substrate. Is done. As shown in FIG. 10A (a), in a state before the permeable layer is formed, the particles are separated from the light-transmitting base material without contacting the light-transmitting base material due to the sedimentation preventing effect of the thixotropic agent. Tends to exist in a state. When the permeable layer is formed, the resin located on the light-transmitting substrate side, that is, the resin located below the particles (light-transmitting substrate side) is mainly used for the permeable layer. Infiltrate. Thereby, in the present invention, following the infiltration of the resin into the translucent substrate, the particles that aggregate in the surface direction of the anti-glare layer and the resin covering the same together form the transparent resin. Move to the optical substrate side. That is, the particles are as shown in FIG.
While maintaining the agglomerated state shown in FIG. 10A, as shown in FIG. 10A (b), it is moved to the transparent substrate side. Thereby, the particles on the surface of the antiglare layer and the resin covering the particles maintain a surface shape thereof, and as a whole, fall into the transparent substrate side. Thus, it is presumed that the antiglare film of the present invention is less susceptible to a change in the surface shape of the antiglare layer.

Furthermore, in the present invention, the resin is thixotropy (
Thixotropy). For this reason, even when the permeation layer is formed thick, it is presumed that the resin that covers the surface of the particle group and forms the convex portion does not easily move to the transparent base material side.
Together with such effects, it is presumed that the anti-glare film of the present invention is less susceptible to a change in the surface shape of the anti-glare layer.

As described above, in the present invention, the antiglare layer has the penetrating layer due to a synergistic effect between the particles and the translucent substrate in the thickness direction and the thixotropic property of the thixotropic agent. It is presumed that even if the anti-glare layer is used, the surface shape of the anti-glare layer is hardly changed.

With reference to FIG. 10B, a case of an antiglare film different from the present invention, which does not include a thixotropic agent, will be described. When the thixotropy-imparting agent is not contained, as described above, the particles do not have the effect of preventing the thixotropy-imparting agent from settling. Therefore, FIG.
As shown in ()), the particles tend to exist at positions in contact with the translucent substrate. Furthermore, the particles cannot move to a permeable layer formed by the resin penetrating the light-transmitting substrate. Therefore, when the permeable layer is formed, the particle group shown in FIG. 10B (a) stays at that position in contact with the translucent base material, and only the resin around the particle group is removed. And penetrates into the translucent substrate. As a result, as shown in FIG. 10B (b), the amount of resin on the surface of the anti-glare layer is reduced with respect to the particle group remaining at that position, so that the surface shape of the anti-glare layer tends to change. It is presumed that projections on the surface of the antiglare layer, which are defects in appearance, become more conspicuous.

<(2) Conditions for coating liquid used>
In the method for producing an anti-glare film of the present invention, the composition of the coating liquid, by causing the coating liquid applied to the translucent substrate to shear, if the particles can be unevenly distributed, There is no particular limitation.

In the present invention, the coating liquid may include a resin, particles, a thixotropy-imparting agent, and a solvent, and satisfy at least one of the following conditions (I) and (II).
(I) In a linear approximation between the amount of the thixotropy-imparting agent and the Ti value in a range where the Ti value defined by the formula (A) is 1.2 to 3.5, the contribution ratio R ² is 0.95 or more.
(II) A quadratic polynomial approximation y = y between the amount x of the thixotropy-imparting agent and the Ti value y when the Ti value defined by the formula (A) is in the range of 1.2 to 3.5. The quadratic coefficient a at ax ² + bx + c is a negative value.

While using a coating solution that satisfies at least one of the conditions (I) and (II),
By performing the step of causing the coating liquid to undergo shearing as described below, an antiglare film having excellent display characteristics that achieves both antiglare properties and prevention of white blur can be produced. Less than,
The conditions ((I) and (II)) of the coating solution used will be described in detail.

FIG. 1A shows an example of a coating liquid satisfying the condition (I) (an example satisfying the condition (I)).
And the relationship between the added amount of the thixotropic agent and the Ti value in one example (conventional example) of a coating liquid used in a conventional production method. In the figure, the coating liquid of “an example satisfying the condition (I)” can be used in the production method of the present invention, and the coating liquid of “conventional example” cannot be used in the production method of the present invention. The present inventors first selected resins, particles, thixotropy-imparting agents, and the like, and adjusted the amounts thereof in order to obtain the desired antiglare film. Thus, as a result of intensive research, the present inventors have found that even if the amount of the thixotropy-imparting agent added and the Ti value are substantially equal to each other, the obtained anti-glare New knowledge that there is a difference between the anti-glare property and the white blur property of the conductive film. That is, even if a coating liquid in which the amount of the thixotropy-imparting agent added and the Ti value are within a predetermined range is prepared, desired characteristics may not be obtained.

Thus, when comparing the coating liquid in which an antiglare film having good characteristics is obtained with the coating liquid in which only an antiglare film having insufficient characteristics is obtained, a Ti value of 1.2 is obtained. ~ 3.5
It has been found that there is a significant difference in the linear approximation or the quadratic polynomial approximation between the amount of the thixotropic agent and the Ti value in the range of.

As shown in the graph of “an example satisfying the condition (I)” in FIG. 1A, when the amount of the thixotropy-imparting agent and the Ti value have a nearly linear relationship, The rise of the Ti value is fast, and an antiglare film having good characteristics can be obtained. On the other hand, as shown in the graph of “conventional example” in FIG. 1A, the amount of the thixotropic agent added and the amount of the Ti
When the Ti value does not have a linear relationship and the rise of the Ti value with the increase in the amount of addition is slow, only an antiglare film having insufficient characteristics can be obtained. When expressed this in linear approximation equation of the amount and the Ti value of the thixotropy-imparting agent, and a contribution ratio R ² is 0.95 or more (the condition (I)), The addition of the thixotropy-imparting agent Quantity x and said Ti value y
If the secondary coefficient a in the secondary polynomial approximation y = ax ² + bx + c is a negative value (the condition (II)), the coating liquid for obtaining the target anti-glare film can be obtained. I found it could be used. The contribution ^{R 2} is preferably 0.96 or more.

The graph of FIG. 1B shows another example of the relationship between the added amount of the thixotropic agent and the Ti value, which is different from FIG. 1A. FIG. 1 is the same as FIG. 1A except that graphs (curves) of “example satisfying condition (II)” and “conventional example” are additionally shown in the graphs of “example satisfying condition (I)” and “conventional example”.
Same as A. The curve of “an example satisfying the condition (II)” indicates that the coating liquid is in the condition (I).
I) That is, in the case where the Ti value is in the range of 1.2 to 3.5, the quadratic polynomial approximation y = ax ² + bx + c of the addition amount x of the thixotropic agent and the Ti value y This is an example in which the coefficient a satisfies the condition that the coefficient a is a negative value. As shown in FIG.
) Is a curve in the region where the amount of the thixotropic agent is small.
The value rises rapidly, and thereafter, the amount of increase in the Ti value becomes gentle. In the production method of the present invention, the coating liquid satisfies at least one of the conditions (I) and (II), thereby having an excellent anti-glare property having excellent anti-glare properties and prevention of white blur. The conductive film can be formed by utilizing the aggregation of particles. Further, in the present invention, the coating liquid,
Even if it does not satisfy at least one of the conditions (I) and (II), as described above, the particles are unevenly distributed by causing the coating liquid applied to the translucent substrate to shear. Anything that can be done.

The schematic diagram of FIG. 2 shows the relationship between the amount of the thixotropic agent and the assumed distribution of the thixotropic agent. Note that the distribution state of the thixotropic agent shown in FIG. 2 is an example of a distribution state that can be assumed, and the present invention is not limited or limited by this assumption.

In the coating liquid from which the desired antiglare film can be obtained, even if the amount of the thixotropy-imparting agent is small, the network structure of the thixotropy-imparting agent is formed as shown in FIG. It is considered that the imparting agent aggregates in the coating liquid to form a plurality of network structures, and the network structures are present independently of other network structures. That is, the thixotropic agent is distributed in a coarse and dense state.

On the other hand, in the case of a coating liquid in which only an antiglare film having insufficient properties can be obtained, as shown in FIG. 2 (b), when the amount of the thixotropic agent is small, the amount of the thixotropic agent is small. The network structure is not formed, and when a certain amount or more is added, the network structure is formed for the first time and shows thixotropy as shown in (c). In the state (c), the coarse-density state is not formed, and it is considered that the network structure is formed over the entire coating liquid.

<(3) Step of causing shear in coating liquid>
Further, the present invention provides that, even when a coating solution that satisfies the above condition (X) or at least one of the conditions (I) and (II) is used, if this coating solution is not sheared, It has been found that the desired antiglare film cannot be obtained. That is, according to the present invention, by forming the surface shape of the anti-glare layer by unevenly distributing particles by the shearing, an anti-glare film for the purpose of achieving both anti-glare properties and prevention of white blur is provided. Can be manufactured.

FIGS. 4A and 4B are explanatory diagrams illustrating an example of a step of causing a shear in a coating liquid applied to a light-transmitting substrate. FIG. 4A is an explanatory diagram illustrating an example of a process of causing the coating liquid applied to the light-transmitting substrate to shear by tilting the light-transmitting substrate. FIG. 4B is an explanatory diagram illustrating an example of a process of applying a centrifugal force to the light-transmitting base material to cause shear in the coating liquid applied to the light-transmitting base material.

In the formation of the antiglare layer, the shear distance S of the coating film defined by the following formula (B) is set to 0.
. It is preferable to set it in the range of 005 × 10 ⁻⁹ m to 120 × 10 ⁻⁹ m. The shear distance S is more preferably in the range of ^{0.005 × 10 -9 m~60 × 10 -9} m, more preferably of ^{0.01 × 10 -9 m~15 × 10 -9} m Within range.

S = ∫Vdt (B)

In the above formula (B),
S: Shear distance (m)
V: Shear rate (m / s)
t: Shear holding time (s)
It is. However, the shear speed V may change over time or may be constant.

A method for calculating the shear rate V of the coating film will be described with reference to FIG. The mass of the fluid shown in FIG. 3 is m (kg), the thickness of the fluid is h (m), and the contact area between the fixed flat plate and the fluid is A.
(M ² ), the velocity (shear rate) V (m / s) of the upper part of the fluid is given by the equation V = mah / A
η. Here, a is the acceleration (m / s ² ), and η is the viscosity (Pa · s) of the fluid. Since the specific gravity k (kg / m ³ ) of the fluid is k = m / hA, V = mah / Aη = k
ah ² / η. Therefore, as described above, the shear rate V of the coating film applied on the translucent substrate is defined by the following equation (C).

V = kah ² / η (C)

In the above formula (C),
k: specific gravity of coating film (kg / m ³ )
a: acceleration (m / s ² )
h: Film thickness (m)
η: Coating viscosity (Pa · s)
It is. However, the acceleration a may change over time or may be constant. When the acceleration a and the shear velocity V do not change with time and are constant, the shear distance S is expressed by the following equation (B ′).

S = V × t (B ′)

As can be seen from the equations (B) and (B ′), (1) the acceleration a is increased, (2)
If the coating thickness h is increased or (3) the coating viscosity η is reduced, the shear rate V
Can be increased. If the shear velocity V of the coating film is increased, a difference occurs in the moving speed of the resin and the particles in the thickness direction of the coating film, and the chance of the particles contacting each other increases.
As a result, aggregation (shear aggregation) of the particles occurs. The shear aggregation is likely to occur by using a coating liquid containing a thixotropic agent. The shear rate V of the coating film is 0.
It is preferably in the range of 05 × 10 ⁻⁹ m / s to 2.0 × 10 ⁻⁹ m / s, more preferably 0.05 × 10 ⁻⁹ m / s to 1.0 × 10 ^−9. m / s.

With reference to FIG. 4, a method for adjusting the shear rate V of the coating film will be described. In FIG. 4, reference numeral 20 denotes a translucent substrate, reference numeral 21 denotes a coating film, reference numeral 12 denotes particles, and reference numeral 13 denotes
3 shows a thixotropic agent. FIG. 4A shows a state in which the translucent base material 20 is inclined.
This is an example in which the shear rate V of the coating film 21 is increased. As shown in FIG. 4A, for example, by inclining the translucent substrate 20, the component of the gravitational acceleration along the inclining direction becomes the acceleration a, and the shear velocity V of the coating film 21 increases. can do. FIG. 4B shows an example in which the translucent base material 20 kept horizontal is rotated on a rotating body to increase the shear rate V of the coating film 21. For example, as shown in FIG.
By rotating 0 on the rotating body, the acceleration a increases due to the centrifugal force, and the shear velocity V of the coating film 21 can be increased.

FIG. 5 illustrates a case where the shearing speed V changes with time. In the figure, the shear rate V is changed from the shear rate V ₁ (shear holding time t ₁ ) to the shear rate V ₂ (shear holding time t ₂ ), and further, the shear rate V ₃ (shear holding time t ₃₎ FIG. In this case, the shear distance S is, for example, a shear distance at each shear rate, that is, a shear distance S ₁ (V ₁ × t ₁ ), a shear distance S ₂ (V ₂ × t ₂ ), and a shear distance S ₃ ( V ₃ × t ₃ ) (S = S ₁ + S ₂ + S ₃ ). In FIG. 5, the translucent substrate 20 is conveyed from the left side to the right side by the coater line, and the coating liquid 22 is applied to the translucent substrate 20 at the left end in the figure. And the translucent substrate 20
Tilt angle during conveyance, change from a first angle of inclination theta ₁ to the second inclination angle theta _2, further third inclined angle theta ₃
, The acceleration a changes, so that the shear speed V is changed as described above.

As described above, in the present invention, the surface shape of the antiglare layer is formed by utilizing the aggregation of particles, but the above-described coating liquid is used, and the coating liquid applied to the light-transmissive substrate is used. By causing shearing, an anti-glare film having excellent display characteristics and having both anti-glare properties and prevention of white blur can be manufactured. The reason is not clear, but can be inferred as follows. However, the present invention is not limited or limited by this inference.

By causing the coating liquid applied to the translucent substrate to shear, the state of the coating liquid is such that the network structure of the thixotropic agent is formed as described above (see FIG. 2A). It is considered that the thixotropic agent aggregates in the coating liquid to form a plurality of network structures, and the network structure is considered to be present independently of other network structures. That is, the thixotropic agent is distributed in a coarse and dense state. It is considered that the particles are unevenly distributed and form a surface shape by the distribution of the thixotropic agent in a coarse and dense state. As a result, as shown in FIG. 7A, it is considered that the convex portion 14 has a gentle shape.

On the other hand, in the state of FIG. 2 (c), as described above, regardless of whether or not shear occurs, the thixotropy-imparting agent does not become a dense state as shown in FIG. 2 (a),
The whole of the coating liquid is densely gathered. Therefore, the thixotropic agent cannot move freely in the coating liquid and does not aggregate. Therefore, uneven distribution (aggregation) of particles due to the aggregation action of the thixotropic agent does not occur. As a result, when the coating liquid in the state of FIG. 2C is used, it is considered that fine unevenness is likely to be formed instead of a smooth surface shape.

Furthermore, in the state of FIG. 2B where the network structure of the thixotropy-imparting agent is not formed, even if the coating liquid is sheared, the thixotropy-imparting agent does not aggregate, and almost all the irregularities required for the antiglare property are formed. However, sufficient anti-glare properties cannot be obtained.

As described above, in the coating liquid applied to the light-transmissive substrate, by causing shear in which the thixotropy-imparting agent is aggregated, the particles are unevenly distributed due to the aggregation action of the thixotropy-imparting agent, and the surface of the antiglare layer is formed. A shape (convex portion) is formed. Thereby, in addition to being able to prevent the occurrence of protrusions on the surface of the anti-glare layer, which becomes the above-described appearance defect, the aggregation state of the particles can be controlled without depending on the aggregation characteristics of the particles, thereby. An antiglare layer having a desired surface unevenness can be formed.

Furthermore, in the present invention, for example, a coating liquid using particles having excellent aggregation characteristics, such as particles having a hydrophobic group or a hydrophilic group introduced on the surface, can also be used preferably. The reason is as follows. That is, the thixotropy-imparting agent contained in the coating liquid, for particles having excellent aggregation properties,
It has the effect of suppressing the cohesion (the effect acting in the direction of dispersing the particles). As described above, for example, in the case of particles having a hydrophobic group or a hydrophilic group introduced on the surface, it is difficult to stably produce the same characteristics, and precise control of production conditions is performed in the coating and drying steps. Even so, it was difficult to stably form the surface shape. However, by using the method of the present invention, the surface shape can be stably formed even in the particles. Further, as described above, the particles in the coating liquid may swell due to the solvent, and the swelling changes the aggregation characteristics of the particles over time. Therefore, after the coating liquid is adjusted, the aggregation state of the particles in the coating liquid is affected due to the lapse of time until the actual production process is started, and it is difficult to stably form the surface shape. There is a problem. According to the present invention, such a problem can also be prevented, and even when a coating liquid using particles having excellent agglomeration properties is used, a stable shape can be formed by employing a shearing step. Can be.

The shear holding time t (the shear distance S is 0.005 × 10 ⁻⁹ m to 120 × 10
^The time to be within the range of ⁻⁹ m) is preferably adjusted within the range of 0.1 to 60 s (second), and more preferably adjusted within the range of 1 to 10 s in consideration of productivity and the like. .

The coating liquid preferably exhibits thixotropy, and the Ti value is 1.3 to 3.5.
, Preferably in the range of 1.4 to 3.2, more preferably in the range of 1.5 to 3.0.

When the Ti value is less than 1.3, appearance defects are likely to occur, and the anti-glare property and white blur characteristics may be deteriorated. On the other hand, when the Ti value exceeds 3.5, the particles hardly aggregate and tend to be in a dispersed state, so that it is difficult to obtain the antiglare film of the present invention.

In the antiglare film obtained by the production method of the present invention, as described above, the antiglare layer,
The particles and the thixotropic agent are aggregated to have an aggregation portion that forms a convex portion on the surface of the anti-glare layer, and in the aggregate portion that forms the convex portion, the particle is A plurality of the antiglare layers are present in the plane direction of the antiglare layer. Thereby, the convex portion,
It has a gentle shape. The anti-glare film of the present invention has such a convex portion, while maintaining the anti-glare property, and can prevent white blur, and furthermore, it is difficult to cause appearance defects. Can be.

The surface shape of the antiglare layer can be arbitrarily designed by controlling the aggregation state of the particles contained in the antiglare layer forming material. The aggregation state of the particles is, for example, the material of the particles (for example,
The chemical modification state of the particle surface, the affinity for a solvent or a resin, etc.), the type of resin (binder) or the solvent, the combination, and the like can be controlled, but the Ti value is in the range of 1.3 to 3.5 in the linear approximate expression amount of thixotropic agent and the Ti value, contribution ratio R ² 0
. If it is 95 or more, it can be used as a coating liquid for obtaining a suitable surface shape.
Alternatively, a quadratic coefficient a in a quadratic polynomial approximation y = ax ² + bx + c of the addition amount x of the thixotropy-imparting agent and the Ti value y when the Ti value is in the range of 1.3 to 3.5. Is a negative value, it can be used as a coating liquid for obtaining a suitable surface shape. Here, in the present invention, the aggregation state of the particles can be controlled by the thixotropic agent contained in the antiglare layer forming material. As a result, in the present invention, the agglomerated state of the particles can be as described above, and the convex portion can have a gentle shape.

As described above, an anti-glare film can be manufactured by forming the anti-glare layer on at least one surface of the translucent substrate.

As described above, in the antiglare film of the present invention, the antiglare layer has an agglomerated portion that forms a convex portion on the surface of the antiglare layer by agglomeration of the particles. In the aggregation portion forming the shape portion, it is preferable that a plurality of the particles exist in a state of being gathered in a surface direction of the antiglare layer. Thereby, the convex part can be made more gentle. Having a convex portion of such a shape, while maintaining the anti-glare properties of the anti-glare film, and
White blur can be prevented, and furthermore, appearance defects can be hardly caused.

As described above, the coating liquid used in the present invention contains a resin, particles, a thixotropic agent, and a solvent.

<Resin>
Examples of the resin include a thermosetting resin and an ionizing radiation-curable resin that is cured by ultraviolet light or light. As the resin, a commercially available thermosetting resin, ultraviolet curing resin, or the like can be used. Examples of the thermosetting resin or the ultraviolet curing resin include heat, light (ultraviolet light, etc.).
Alternatively, a curable compound having at least one of an acrylate group and a methacrylate group that is cured by an electron beam or the like can be used, for example, a silicone resin, a polyester resin, a polyether resin, an epoxy resin, a urethane resin, an alkyd resin, and a spiro acetal resin. And polybutadiene resins, polythiol polyene resins, and oligomers or prepolymers of polyfunctional compounds such as polyhydric alcohols such as acrylates and methacrylates. These may be used alone or in combination of two or more.

For the resin, for example, a reactive diluent having at least one of an acrylate group and a methacrylate group can also be used. The reactive diluent is described in, for example, JP-A-200
The reactive diluent described in JP-A-8-88309 can be used, and examples thereof include monofunctional acrylate, monofunctional methacrylate, polyfunctional acrylate, and polyfunctional methacrylate.
As the reactive diluent, trifunctional or higher acrylate and trifunctional or higher methacrylate are preferable. This is because the hardness of the antiglare layer can be made excellent. Examples of the reactive diluent include butanediol glycerin ether diacrylate, acrylate of isocyanuric acid, methacrylate of isocyanuric acid, and the like. These may be used alone or in combination of two or more.

<Particles>
The particles for forming the anti-glare layer, the anti-glare layer surface to be formed to impart an anti-glare property to the uneven shape, and also has a main function of controlling the haze value of the anti-glare layer . The haze value of the antiglare layer can be designed by controlling the difference in the refractive index between the particles and the resin.
Examples of the particles include inorganic particles and organic particles. The inorganic particles are not particularly limited, for example, silicon oxide particles, titanium oxide particles, aluminum oxide particles, zinc oxide particles, tin oxide particles, calcium carbonate particles, barium sulfate particles, talc particles, kaolin particles, calcium sulfate particles, and the like. Is raised. The organic particles are not particularly limited. For example, polymethyl methacrylate resin powder (PMMA fine particles), silicone resin powder, polystyrene resin powder, polycarbonate resin powder, acrylic styrene resin powder, benzoguanamine resin powder, melamine resin powder, polyolefin Resin powder, polyester resin powder, polyamide resin powder, polyimide resin powder, polyfluoroethylene resin powder, and the like. One type of these inorganic particles and organic particles may be used alone, or two or more types may be used in combination.

The particle diameter (D) (weight average particle diameter) of the particles is preferably in the range of 2.5 to 10 μm. By setting the weight average particle size of the particles in the above range, for example, an antiglare film having more excellent antiglare properties and capable of preventing white blur can be obtained. The weight average particle size of the particles is more preferably in the range of 3 to 7 μm. Incidentally, the weight average particle size of the particles,
For example, it can be measured by the Coulter counting method. For example, using a particle size distribution analyzer (trade name: Coulter Multisizer, manufactured by Beckman Coulter, Inc.) using a pore electric resistance method, the electrolyte solution corresponding to the volume of the particles when the particles pass through the pores is used. The number and volume of the particles are measured by measuring the electric resistance, and the weight average particle size is calculated.

The shape of the particles is not particularly limited, and may be, for example, a bead-like substantially spherical shape or an irregular shape such as a powder, but is preferably a substantially spherical shape, and more preferably an aspect ratio. Substantially spherical particles having a ratio of 1.5 or less, most preferably spherical particles.

The ratio of the particles in the antiglare layer is preferably in the range of 0.2 to 12 parts by weight, more preferably in the range of 0.5 to 12 parts by weight, and still more preferably 100 parts by weight of the resin. It is in the range of 1 to 7 parts by weight. By setting the above range, for example, more excellent anti-glare properties,
In addition, an antiglare film capable of preventing white blur can be obtained.

<Thixotropic agent>
Examples of the thixotropy-imparting agent for forming the antiglare layer include organoclay, polyolefin oxide, and modified urea.

The organic clay is preferably a layered clay that has been subjected to an organic treatment in order to improve the affinity with the resin. The organic clay may be prepared in-house or a commercially available product may be used. Examples of the commercially available products include Lucentite SAN, Lucentite STN, Lucentite SEN, Lucentite SPN, Somasif ME-100, Somasif MAE, Somasif MTE, Somasif MEE, Somasif MPE (trade names, Corp Chemical Co., Ltd.) )
Esven, Esven C, Esven E, Esven W, Esven P, Esven WX, Esven N-400, Esven NX, Esven NX80, Esven NO12S, Esven NEZ
, Esven NO12, Esven NE, Esven NZ, Esven NZ70, Organite,
Organite D and Organite T (trade names, both manufactured by Hojun Co., Ltd.); Kunipia F
, Kunipia G, Kunipia G4 (trade names, all manufactured by Kunimine Industries Co., Ltd.); Thixogel V
Z, Clayton HT, Clayton 40 (trade names, all manufactured by Rockwood Additives) and the like.

The oxidized polyolefin may be prepared in-house or a commercially available product may be used. Examples of the commercially available products include Disparon 4200-20 (trade name, manufactured by Kusumoto Kasei Co., Ltd.) and Flowon SA300 (trade name, manufactured by Kyoeisha Chemical Co., Ltd.).

The modified urea is a reaction product of an isocyanate monomer or an adduct thereof and an organic amine. The modified urea may be prepared in-house or a commercially available product may be used. Examples of the commercially available product include BYK410 (manufactured by Big Chemie).

The ratio of the thixotropic agent in the coating liquid is preferably in the range of 0.2 to 5 parts by weight, more preferably in the range of 0.4 to 4 parts by weight, based on 100 parts by weight of the resin.

As the thixotropic agent, one kind may be used alone, or two or more kinds may be used in combination.

<Solvent>
The solvent is not particularly limited, and various solvents can be used. One type may be used alone, or two or more types may be used in combination. There is an optimum solvent type and solvent ratio depending on the composition of the resin, the type and the content of the particles and the thixotropic agent. Examples of the solvent include, but are not particularly limited to, alcohols such as methanol, ethanol, isopropyl alcohol, butanol, and 2-methoxyethanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclopentanone; methyl acetate, acetic acid Esters such as ethyl and butyl acetate; ethers such as diisopropyl ether and propylene glycol monomethyl ether; glycols such as ethylene glycol and propylene glycol; cellosolves such as ethyl cellosolve and butyl cellosolve; and aliphatic carbons such as hexane, heptane and octane. Hydrogens include aromatic hydrocarbons such as benzene, toluene, and xylene.

Further, by appropriately selecting the solvent, the thixotropy (thixotropic property) of the antiglare layer forming material (coating liquid) by the thixotropy-imparting agent can be favorably exhibited. For example,
When using an organic clay, toluene and xylene can be suitably used alone or in combination.For example, when using an oxidized polyolefin, methyl ethyl ketone, ethyl acetate, and propylene glycol monomethyl meter are preferably used alone or When modified urea is used, for example, butyl acetate and methyl isobutyl ketone can be suitably used alone or in combination.

<Other additives>
Various leveling agents can be added to the coating liquid. As the leveling agent, for example, a fluorine-based or silicone-based leveling agent can be used for the purpose of preventing coating unevenness (uniform coating surface). In the present invention, when antifouling properties are required on the surface of the antiglare layer, or when an antireflection layer (low refractive index layer) or a layer containing an interlayer filler is formed on the antiglare layer as described later, The leveling agent can be appropriately selected according to the conditions. In the present invention, for example, by including the thixotropy-imparting agent, thixotropy can be exhibited in the coating liquid, and coating unevenness is less likely to occur. For this reason, the present invention has an advantage that, for example, options of the leveling agent can be expanded.

The compounding amount of the leveling agent is, for example, 5 parts by weight or less, preferably 0.01 to 5 parts by weight, based on 100 parts by weight of the resin.

The coating liquid, if necessary, as long as the performance is not impaired, a pigment, a filler, a dispersant, a plasticizer, an ultraviolet absorber, a surfactant, an antifouling agent, an antioxidant and the like are added. Is also good. One of these additives may be used alone, or two or more thereof may be used in combination.

For the coating liquid, for example, a conventionally known photopolymerization initiator as described in JP-A-2008-88309 can be used.

In the present invention, the coating liquid is applied to at least one surface of the translucent substrate to form a coating film, and the shear distance S of the applied coating liquid is 0.005 × 10 ⁻⁹ m to 120 × 10 ⁻
It is preferable to be within a range of ⁹ m.

Examples of the method of applying the coating liquid on the light-transmitting substrate to form a coating film include a fountain coating method, a die coating method, a spin coating method, a spray coating method, a gravure coating method, and a roll coating method. And a coating method such as a bar coating method.

<Transparent plastic film substrate>
The transparent plastic film substrate is not particularly limited, but has excellent visible light transmittance (preferably 90% or more) and excellent transparency (preferably 1% haze value).
The following are preferable, and examples thereof include a transparent plastic film substrate described in JP-A-2008-90263. As the transparent plastic film substrate, one having optically low birefringence is suitably used. The antiglare film of the present invention can be used, for example, as a protective film on a polarizing plate. In this case, as the transparent plastic film substrate, triacetyl cellulose (TAC), polycarbonate, an acrylic polymer, A film formed from a polyolefin having a cyclic or norbornene structure is preferred. In the present invention, as described later, the transparent plastic film substrate may be a polarizer itself. With such a configuration, a protective layer made of TAC or the like is not required and the structure of the polarizing plate can be simplified, so that the number of manufacturing steps of the polarizing plate or the image display device can be reduced, and the production efficiency can be improved. Further, with such a configuration, the polarizing plate can be made thinner. When the transparent plastic film substrate is a polarizer, the antiglare layer serves as a conventional protective layer. In addition, with such a configuration, the anti-glare film also functions as a cover plate when it is mounted on the surface of the liquid crystal cell, for example.

In the present invention, the thickness of the transparent plastic film substrate is not particularly limited,
For example, considering the workability such as strength and handleability and the thin layer property, it is 10 to 50.
It is preferably in the range of 0 μm, more preferably in the range of 20 to 300 μm, and most preferably 3 μm.
It is in the range of 0 to 200 μm. The refractive index of the transparent plastic film substrate is not particularly limited. The refractive index is, for example, in the range of 1.30 to 1.80, and preferably 1.
It is in the range of 40 to 1.70.

<Permeation layer>
In the anti-glare film of the present invention, when the light-transmitting substrate is formed of a resin or the like, it is preferable to have a permeable layer at the interface between the light-transmitting substrate and the anti-glare layer. The penetrating layer is formed by permeating a resin component contained in a material for forming the antiglare layer into the translucent substrate. The formation of the penetrating layer is preferable because the adhesion between the light-transmitting substrate and the antiglare layer can be improved. The thickness of the permeable layer is preferably in the range of 0.2 to 3 μm, more preferably in the range of 0.5 to 2 μm. For example, when the translucent substrate is triacetyl cellulose and the resin contained in the antiglare layer is an acrylic resin, the permeable layer can be formed. The permeable layer is formed, for example, by cross-sectioning an antiglare film with a transmission electron microscope (T
By observing with EM), it can be confirmed and the thickness can be measured.

In the anti-glare film of the present invention, even when applied to an anti-glare film having such a penetrating layer, both anti-glare properties and prevention of white blur are achieved, and the desired smooth surface unevenness is obtained. It can be easily formed. The penetrating layer is preferably formed to be thicker as the translucent base material has poor adhesion to the antiglare layer in order to improve adhesion.

When the permeable layer is formed by using, for example, triacetyl cellulose (TAC) as the translucent substrate, a good solvent for TAC can be suitably used. As the solvent, for example,
Examples include ethyl acetate, methyl ethyl ketone, and cyclopentanone.

<Anti-glare layer>
The antiglare layer is formed by curing the coating film. It is preferable to dry the coating film before the curing. The drying may be, for example, natural drying, air drying by blowing air, heat drying, or a method combining these.

The means for curing the coating film is not particularly limited, but ultraviolet curing is preferable. The irradiation amount of the energy ray source is preferably 50 to 500 mJ / cm ² as an integrated exposure amount at an ultraviolet wavelength of 365 nm. When the irradiation amount is 50 mJ / cm ² or more, the curing becomes more sufficient, and the hardness of the formed antiglare layer becomes more sufficient. In addition, when it is 500 mJ / cm ² or less, coloring of the formed antiglare layer can be prevented.

The thickness (d) of the antiglare layer is not particularly limited, but is preferably in the range of 3 to 12 μm. By setting the thickness (d) of the antiglare layer in the above range, for example, it is possible to prevent the occurrence of curling in the antiglare film, and it is possible to avoid a problem of a decrease in productivity such as poor transportability. When the thickness (d) is in the above range, the weight average particle diameter (D) of the particles is preferably in the range of 2.5 to 10 μm as described above. Thickness (d) of the antiglare layer
When the weight average particle diameter (D) of the particles is in the above-mentioned combination, an antiglare film having more excellent antiglare properties can be obtained. The thickness (d) of the antiglare layer is more preferably in the range of 3 to 8 μm.

The relationship between the thickness (d) of the antiglare layer and the weight average particle size (D) of the particles is 0.3 ≦ D / d
Preferably, it is within the range of ≦ 0.9. With such a relationship, an antiglare film having more excellent antiglare properties, preventing white blur, and having no external defects can be obtained.

In the antiglare film of the present invention, it is preferable that the height of the convex portions from the average roughness line of the antiglare layer is less than 0.4 times the thickness of the antiglare layer. More preferably, it is in the range of 0.01 times or more and less than 0.4 times, and further preferably, it is in the range of 0.01 times or more and less than 0.3 times. Within this range, it is possible to suitably prevent the formation of a projection as an appearance defect on the convex portion. The anti-glare film of the present invention has a convex portion having such a height,
It is possible to reduce appearance defects. Here, the height from the average line is shown in FIG.
This will be described with reference to FIG. FIG. 6 is a schematic diagram of a two-dimensional profile of a cross section of the antiglare layer,
The straight line L is a roughness average line (center line) in the two-dimensional profile. The height H of the top (projection) from the roughness average line in the two-dimensional profile is defined as the height of the projection in the present invention. In FIG. 6, a portion of the convex portion that exceeds the average line is indicated by a parallel diagonal line. Further, the thickness of the antiglare layer is a thickness of the antiglare layer calculated by measuring the entire thickness of the antiglare film and subtracting the thickness of the light-transmitting substrate from the entire thickness. The total thickness and the thickness of the translucent substrate can be measured by, for example, a micro gauge type thickness gauge.

In the anti-glare film of the present invention, it is preferable that the anti-glare layer has one or more external defects having a maximum diameter of 200 μm or more per 1 m ^{2 of the} anti-glare layer. More preferably, there is no appearance defect.

The antiglare film of the present invention preferably has a haze value in the range of 0 to 10%. The haze value is a haze value (cloudiness) of the entire antiglare film according to JIS K 7136 (2000 version). The haze value is more preferably in the range of 0 to 5%, and still more preferably in the range of 0 to 3%. In order to set the haze value in the above range, it is preferable to select the particles and the resin such that the refractive index difference between the particles and the resin is in the range of 0.001 to 0.02. When the haze value is within the above range, a clear image can be obtained, and the contrast in a dark place can be improved.

The anti-glare film of the present invention has the unevenness on the surface of the anti-glare layer according to JIS B 060.
1 (1994 version) preferably has an arithmetic average surface roughness Ra in the range of 0.03 to 0.45 μm, more preferably 0.04 to 0.40 μm. In order to prevent external light and images from being reflected on the surface of the antiglare film, it is preferable that the surface has a certain degree of surface roughness. However, the reflection can be improved when Ra is 0.03 μm or more. When the Ra is within the above range, when used in an image display device or the like, scattering of reflected light when viewed from an oblique direction is suppressed, white blur is improved, and contrast in a bright place is also improved. be able to.

In the uneven shape, the average distance Sm (mm) between unevenness of the surface measured according to JIS B 0601 (1994 version) is preferably in the range of 0.05 to 0.4, more preferably 0.08 to 0. .3. By setting the content in the above range, for example, an antiglare film having more excellent antiglare properties and preventing white blur can be obtained.

The anti-glare film of the present invention has an average inclination angle θa (°
) Is preferably in the range of 0.1 to 1.5, more preferably in the range of 0.2 to 1.0. Here, the average inclination angle θa is a value defined by the following equation (1). The average inclination angle θa is, for example, a value measured by a method described in Examples described later.
Average inclination angle θa = tan ⁻¹ Δa (1)

In the formula (1), Δa is JIS B 060 as shown in the following formula (2).
1 (1994 version), the total (h1 + h2 + h3... + Hn) of the difference (height h) between the peak of the adjacent peak and the lowest point of the valley in the reference length L of the roughness curve. Reference length L
Divided by. The roughness curve is a curve obtained by removing a surface waviness component longer than a predetermined wavelength from a cross-sectional curve by a phase difference compensation type high-pass filter. Further, the cross-sectional curve is a contour that appears at the cut when the target surface is cut along a plane perpendicular to the target surface.
Δa = (h1 + h2 + h3... + Hn) / L (2)

When all of Ra, Sm and θa are in the above ranges, an antiglare film having more excellent antiglare properties and capable of preventing white blur can be obtained.

The hardness of the antiglare film of the present invention is affected by the thickness of the
It preferably has a hardness of H or higher.

As an example of the anti-glare film of the present invention, a film in which an anti-glare layer is formed on one surface of a transparent plastic film substrate can be given. The anti-glare layer contains particles, so that the surface of the anti-glare layer has an uneven shape. In addition, in this example, the anti-glare layer is formed on one surface of the transparent plastic film substrate, but the present invention is not limited thereto,
An antiglare film having an antiglare layer formed on both surfaces of a transparent plastic film substrate may be used. Further, the antiglare layer in this example is a single layer, but the present invention is not limited thereto, and the antiglare layer may have a multilayer structure in which two or more layers are stacked.

<Anti-reflective layer>
In the antiglare film of the present invention, an antireflection layer (low refractive index layer) may be disposed on the antiglare layer. For example, when an antiglare film is mounted on an image display device, one of the factors that lowers the visibility of an image is reflection of light at the interface between air and the antiglare layer. The anti-reflection layer
This is to reduce the surface reflection. The antiglare layer and the antireflection layer may be formed on both surfaces of a transparent plastic film substrate or the like. Further, each of the antiglare layer and the antireflection layer may have a multilayer structure in which two or more layers are laminated.

In the present invention, the antireflection layer is an optical thin film whose thickness and refractive index are strictly controlled, or a laminate of two or more optical thin films. The anti-reflection layer expresses an anti-reflection function by canceling the inverted phases of the incident light and the reflected light by utilizing the interference effect of light. The wavelength region of visible light for exhibiting the antireflection function is, for example, 380 to 780 nm.
The wavelength region where the visibility is particularly high is in the range of 450 to 650 nm, and it is preferable to design the antireflection layer so as to minimize the reflectance at 550 nm which is the center wavelength.

In designing the anti-reflection layer based on the light interference effect, as a means for improving the interference effect, for example, there is a method of increasing the refractive index difference between the anti-reflection layer and the anti-glare layer. Generally, in a multilayer antireflection layer having a structure in which two to five optical thin layers (thin films whose thickness and refractive index are strictly controlled) are laminated, a plurality of components having different refractive indexes are formed in a predetermined thickness. By doing so, the degree of freedom in the optical design of the antireflection layer increases, and the antireflection effect can be further improved,
The spectral reflection characteristics can also be made uniform (flat) in the visible light region. Since the optical thin film requires high thickness accuracy, each layer is generally formed by a dry method such as vacuum deposition, sputtering, or CVD.

Further, in order to prevent the adhesion of contaminants and to improve the ease of removal of the attached contaminants, a contamination prevention layer formed of a silane compound having a fluorine group or an organic compound having a fluorine group is placed on the antireflection layer. It is preferable to laminate them.

In the antiglare film of the present invention, it is preferable that at least one of the translucent substrate and the antiglare layer is subjected to a surface treatment. If the surface of the translucent substrate is subjected to a surface treatment, the adhesion to the antiglare layer or the polarizer or the polarizing plate is further improved. Further, if the surface of the antiglare layer is subjected to a surface treatment, the adhesion to the antireflection layer or the polarizer or the polarizing plate is further improved.

In the anti-glare film in which the anti-glare layer is formed on one surface of the translucent substrate, the other surface may be subjected to a solvent treatment in order to prevent curling. Further, in an antiglare film in which the antiglare layer is formed on one surface of the translucent substrate or the like, a transparent resin layer may be formed on the other surface to prevent curling. .

<Optical members>
The anti-glare film obtained by the present invention can usually be bonded to the optical member used for LCD through the adhesive or the adhesive on the side of the transparent substrate. In this bonding, the above-described various surface treatments may be performed on the surface of the translucent substrate.

Examples of the optical member include a polarizer and a polarizing plate. The polarizing plate generally has a configuration in which a transparent protective film is provided on one or both sides of the polarizer. When the transparent protective films are provided on both surfaces of the polarizer, the transparent protective films on the front and back may be made of the same material or different materials. Polarizing plates are usually arranged on both sides of the liquid crystal cell. The polarizing plates are arranged such that the absorption axes of the two polarizing plates are substantially orthogonal to each other.

Next, an optical member having the anti-glare film laminated thereon will be described using a polarizing plate as an example. By laminating the anti-glare film with a polarizer or a polarizing plate using an adhesive or a pressure-sensitive adhesive, etc., it has excellent display characteristics that achieve both anti-glare properties and prevention of white blur, and has a defect in appearance. Can be obtained.

The polarizer is not particularly limited, and various types can be used. Examples of the polarizer include a hydrophilic polymer film such as a polyvinyl alcohol-based film, a partially formalized polyvinyl alcohol-based film, an ethylene-vinyl acetate copolymer-based partially saponified film, and a dipolar dye such as iodine or a dichroic dye. Examples thereof include a uniaxially stretched film obtained by adsorbing a coloring substance, and a polyene-based oriented film such as a dehydrated polyvinyl alcohol product or a dehydrochlorinated polyvinyl chloride product.

As the transparent protective film provided on one or both surfaces of the polarizer, those having excellent transparency, mechanical strength, heat stability, moisture shielding property, stability of retardation value, and the like are preferable. Examples of the material for forming the transparent protective film include the same materials as those for the transparent plastic film substrate.

As the transparent protective film, JP-A-2001-343529 (WO01 / 3)
7007). The polymer film can be manufactured by extruding the resin composition into a film. Since the polymer film has a small retardation and a small photoelastic coefficient, when applied to a protective film such as a polarizing plate, it is possible to eliminate defects such as unevenness due to distortion, and because the moisture permeability is small. Excellent in humidification durability.

The transparent protective film is preferably a film made of a cellulose-based resin such as triacetyl cellulose or a film made of a norbornene-based resin from the viewpoint of polarization characteristics and durability. Commercial products of the transparent protective film include, for example, “Fujitac” (trade name, manufactured by FUJIFILM Corporation), “Zeonor” (trade name, manufactured by Zeon Corporation), and “Arton” (trade name, manufactured by JSR Corporation). . Although the thickness of the transparent protective film is not particularly limited, it is, for example, in the range of 1 to 500 μm from the viewpoint of strength, workability such as handleability, thinness, and the like.

The configuration of the polarizing plate laminated with the anti-glare film is not particularly limited, for example, a configuration in which a transparent protective film, the polarizer and the transparent protective film are laminated in this order on the anti-glare film. Alternatively, the polarizer and the transparent protective film may be laminated on the antiglare film in this order.

<Image display device>
The image display device of the present invention has the same configuration as the conventional image display device except that the anti-glare film of the present invention is used. For example, in the case of an LCD, it can be manufactured by appropriately assembling components such as a liquid crystal cell, a polarizing plate and other optical members and, if necessary, an illumination system (such as a backlight) and incorporating a drive circuit.

The image display device of the present invention is used for any appropriate use. Its applications are, for example, OA equipment such as personal computer monitors, notebook computers, copy machines, mobile phones, watches, digital cameras, personal digital assistants (PDAs), mobile equipment such as portable game machines, video cameras, televisions, microwave ovens, etc. Home appliances, back monitors, monitors for car navigation systems,
The equipment includes on-board equipment such as car audio, display equipment such as information monitors for commercial stores, security equipment such as monitoring monitors, care / medical equipment such as care monitors, and medical monitors.

Next, examples of the present invention will be described together with comparative examples. However, the present invention is not limited by the following Examples and Comparative Examples. Various properties in the following Examples and Comparative Examples were evaluated or measured by the following methods.

(Coating film specific gravity k (kg / m ³ ))
The coating liquid was adjusted to 100 ml, and its weight was measured to obtain the specific gravity of the coating film.

(Acceleration a (m / s ² ))
The inclination angle was set to θ, and the calculation was performed by the following equation.
a = gravity acceleration (9.8 m / s ² ) × sin θ

(Film thickness h (m))
Using "MCPD3750" manufactured by Otsuka Electronics Co., non-contact interference film thickness was measured. The coating film refractive index was 1.5.

(Coating viscosity η (Pa · s))
The viscosity measured under the conditions of a shear rate of 200 (1 / s) was measured using Rheostress RS6000 manufactured by HAAKE.

(Surface shape measurement)
A glass plate (thickness: 1.3 mm) manufactured by Matsunami Glass Industry Co., Ltd. is bonded to the surface of the anti-glare film on which the anti-glare layer is not formed with an adhesive, and a high-precision fine shape measuring device (trade name: Surf) The surface shape of the anti-glare layer was measured using a Coda ET4000 (manufactured by Kosaka Laboratory Co., Ltd.) with a cutoff value of 0.8 mm, and the arithmetic average surface roughness Ra, average distance between irregularities Sm, and average inclination were measured. The angle θa was determined. Note that the high-precision fine shape measuring instrument automatically calculates the arithmetic average surface roughness Ra and the average inclination angle θa. The arithmetic average surface roughness Ra and the average inclination angle θ
a is based on JIS B 0601 (1994 version). The average distance between irregularities Sm is the average distance between irregularities (mm) of the surface measured according to JIS B 0601 (1994 version).

(Appearance evaluation)
Prepare an anti-glare film of 1 m ² and use a fluorescent lamp (1000 Lx) in a dark room,
The appearance defect was visually confirmed from a distance of m. The observed external defects were observed using a graduated loupe, the size (maximum diameter) of the external defects was measured, and the number of those having a size of 200 μm or more was counted.

(Evaluation of anti-glare properties)
(1) A black acrylic plate (manufactured by Mitsubishi Rayon Co., Ltd., 2.0 mm thick) was adhered to the surface of the anti-glare film on which the anti-glare layer was not formed with an adhesive, and a sample having no reflection on the back surface was prepared. Produced.
(2) In an office environment generally using a display (about 1000 Lx), the sample was illuminated with a fluorescent lamp (three-wavelength light source), and the anti-glare property of the sample prepared above was visually determined according to the following criteria. .
Judgment criteria G: Excellent in anti-glare properties and does not leave an image of the contour of the fluorescent lamp reflected.
NG: Poor antiglare properties, and an image of the outline of a fluorescent lamp appears.

(White blur evaluation)
(1) A sample in which a black acrylic plate (manufactured by Nitto Jushi Kogyo Co., Ltd., 1.0 mm in thickness) is adhered to the surface of the anti-glare film on which the anti-glare layer is not formed with an adhesive to eliminate reflection on the back surface. Was prepared.
(2) In an office environment using a display (about 1000 Lx), the white blur phenomenon is visually observed from a direction perpendicular to the plane of the sample prepared above as a reference (0 °) at 60 °. And evaluated according to the following criteria.
Criterion AA: Almost no white blur.
A: There is white blur, but the influence on visibility is small.
B: White blur is strong, and visibility is remarkably reduced.

(Weight average particle size of fine particles)
The weight average particle diameter of the fine particles was measured by a Coulter counting method. Specifically, using a particle size distribution measuring device (trade name: Coulter Multisizer, manufactured by Beckman Coulter, Inc.) using a pore electric resistance method, electrolysis corresponding to the volume of the fine particles when the fine particles pass through the fine holes. The number and volume of the fine particles were measured by measuring the electric resistance of the liquid, and the weight average particle diameter was calculated.

(Thickness of anti-glare layer)
The thickness of the anti-glare layer was calculated by measuring the entire thickness of the anti-glare film using a micro gauge thickness gauge manufactured by Mitutoyo Corporation and subtracting the thickness of the light-transmitting substrate from the total thickness. .

(Example 1)
As a resin contained in the coating liquid, 100 parts by weight of an ultraviolet-curable urethane acrylate resin (trade name “UV1700B”, manufactured by Nippon Synthetic Chemical Industry Co., Ltd., solid content 100%) was prepared.
Acrylic and styrene copolymer particles (trade name “Techpolymer”, manufactured by Sekisui Plastics Co., Ltd., weight average particle diameter: 3.0 μm) per 100 parts by weight of resin solid content of the resin,
2 parts by weight of refractive index: 1.52), 0.4 part by weight of synthetic smectite (trade name “Lucentite SAN”, manufactured by Corp Chemical Co., Ltd.) as an organoclay as the thixotropy-imparting agent, and a photopolymerization initiator 3 parts by weight (trade name “IRGACURE 907” manufactured by BASF) and 0.5 part by weight of a leveling agent (trade name “PC4100” manufactured by DIC Corporation, solid content: 10%) were mixed. The organic clay was used after being diluted with toluene so as to have a solid content of 6.0%.
This mixture was mixed with toluene / cyclopentanone (C) such that the solid content concentration became 35% by weight.
PN) The mixture was diluted with a mixed solvent (weight ratio 80/20), and a coating liquid was prepared using an ultrasonic disperser.

As the translucent substrate, a transparent plastic film substrate (triacetyl cellulose film, manufactured by FUJIFILM Corporation, trade name “Fujitac”, thickness: 60 μm, refractive index: 1.49)
Was prepared. The coating solution was applied to one surface of the transparent plastic film substrate using a wire bar to form a coating film. At this time, as shown in FIG. 4A, the transparent plastic film substrate was inclined by 12 °, and the shear rate V of the coating film was set to 0.20 for 10 seconds.
× 10 ⁻⁹ m / s (shear distance S = 2.0 × 10 ⁻⁹ m). Then, at 60 ° C, 60
The coating was dried by heating for minutes. After that, the accumulated light amount is 3
The coating film was irradiated with ultraviolet rays of 00 mJ / cm ² and cured to form an antiglare layer having a thickness of 7 μm. Thus, an antiglare film of Example 1 was obtained.

(Example 2)
By tilting the transparent plastic film substrate by 30 °, the shear rate V of the coating film,
The antiglare property of Example 2 was obtained in the same manner as in Example 1 except that 0.40 × 10 ⁻⁹ m / s (shear distance S = 4.0 × 10 ⁻⁹ m) for 10 seconds. A film was obtained.

(Example 3)
The amount of the thixotropy-imparting agent was 0.8 parts by weight, the transparent plastic film substrate was inclined at 30 °, and the shear rate V of the coating film was 0.62 × 10 ⁻⁹ m / sec for 10 seconds.
An antiglare film of Example 3 was obtained in the same manner as in Example 1 except that s (shear distance S = 6.2 × 10 ⁻⁹ m) was used.

(Example 4)
The amount of the thixotropy-imparting agent was 1.2 parts by weight, the transparent plastic film substrate was inclined at 30 °, and the shear rate V of the coating was 0.28 × 10 ⁻⁹ m / sec for 10 seconds.
An antiglare film of Example 4 was obtained in the same manner as in Example 1, except that s (shear distance S = 2.8 × 10 ⁻⁹ m) was used.

(Example 5)
Example 1 was repeated except that a UV-curable polyfunctional acrylate resin (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name “A-DPH”, solid content 100%) was used as a resin contained in the coating liquid. The anti-glare film of Example 5 was obtained in the same manner.

(Example 6)
As a resin contained in the coating liquid, a UV-curable urethane acrylate resin (manufactured by Toagosei Co., Ltd., trade name “M1960”, solid content 100%) was used, and the transparent plastic film base material was inclined by 12 ° to obtain the resin. The shear rate V of the coating film is set to 0.26 × 10 ⁻⁹ m / s for 10 seconds.
(Shear distance S = 2.6 × 10 ⁻⁹ m), except that it was set in the same manner as in Example 1.
An antiglare film of Example 6 was obtained.

(Comparative Example 1)
Example 1 except that the transparent plastic film substrate was not tilted (0 °) and the shear rate V of the coating film was set to 0 m / s (shear distance S = 0 × 10 ⁻⁹ m) for 10 seconds. In the same manner as in Example 1, an antiglare film of Comparative Example 1 was obtained.

(Comparative Example 2)
Without adding the thixotropy-imparting agent, the transparent plastic film substrate was inclined by 30 °, and the shear rate V of the coating film was set to 0.35 × 10 ⁻⁹ m / s (shear distance S) for 10 seconds.
= 3.5 × 10 ⁻⁹ m), and an antiglare film of Comparative Example 2 was obtained in the same manner as in Example 1.

(Comparative Example 3)
As a resin contained in the coating liquid, an ultraviolet-curable urethane acrylate resin (DIC Corporation)
(Trade name: Unidick 17-806, solid content: 80%), and the shear rate V of the coating film was 0 m / s for 10 seconds without tilting the transparent plastic film substrate (0 °).
(Anti-glare film of Comparative Example 3) was obtained in the same manner as in Example 1 except that (shear distance S = 0 × 10 ⁻⁹ m).

(Comparative Example 4)
As a resin contained in the coating liquid, an ultraviolet-curable urethane acrylate resin (DIC Corporation)
(Trade name: Unidik 17-806, solid content 80%), the amount of the thixotropy-imparting agent added was 0.8 parts by weight, and the transparent plastic film substrate was inclined by 12 ° to form the coating film. For 10 seconds at 0.19 × 10 ⁻⁹ m / s (shear distance S = 1
. An antiglare film of Comparative Example 4 was obtained in the same manner as in Example 1, except that the ^{thickness was} 9 × 10 ⁻⁹ m).

(Comparative Example 5)
As a resin contained in the coating liquid, an ultraviolet-curable urethane acrylate resin (DIC Corporation)
(Trade name: Unidick 17-806, solid content: 80%), the amount of the thixotropy-imparting agent was 1.6 parts by weight, and the transparent plastic film substrate was inclined by 30 ° to form the coating film. , Except that the shear rate V was 0.32 × 10 ⁻⁹ m / s for 10 seconds.
In the same manner as in Example 1, an antiglare film of Comparative Example 5 was obtained.

Various properties were measured or evaluated for the antiglare films of Examples and Comparative Examples thus obtained. The results are shown in Table 1 below. 11 and 12 are graphs showing the relationship between the amount of the thixotropic agent and the Ti value for the resins used in the examples and comparative examples. FIG. 11 shows the amount of the thixotropic agent and the T
FIG. 12 is a graph in which a second-order polynomial approximation curve is given between the amount of the thixotropy-imparting agent and the Ti value.

As shown in Table 1, in Examples, good results were obtained for both the antiglare property and the white blur. On the other hand, in Comparative Example 1 in which the shear rate V of the coating film was 0 m / s and no shear was generated in the coating film, and in Comparative Example 2 in which the thixotropic agent was not included, all of the above properties were satisfactory. Was not obtained. Also, in Comparative Examples 3 to 5 using the “Unidick 17-806” as the resin, none of the above characteristics was good. The compositions of the coating liquids in Comparative Examples 3 to 5 were the same except for the amount of the thixotropic agent (thixo agent) added. Comparative Examples 3 to 5, in the linear approximation formula of the Ti value and amount of the thixotropy-imparting agent, the contribution rate R ² is less than 0.95 wherein not satisfy the condition (I), of the thixotropy-imparting agent The quadratic coefficient a in the quadratic polynomial approximation y = ax ² + bx + c between the addition amount x and the Ti value y is a positive value and does not satisfy the condition (II). Furthermore, in Comparative Example 2 in which the thixotropy-imparting agent was not added, appearance defects were observed in the appearance evaluation.

FIGS. 13 (a) and 14 (a) show optical microscope (semi-transmissive mode) photographs of the surface of the antiglare layer of the antiglare film obtained in Example 1 and Comparative Example 4. FIG. FIGS. 13 (b) and 14 (b) are schematic diagrams showing the distribution of particles observed in the photographs of FIGS. 13 (a) and 14 (a), respectively. In the antiglare film of Example 1, it can be seen that the particles are aggregated (distributed) due to the aggregation action of the thixotropic agent. On the other hand, in the anti-glare film of Comparative Example 4, the particles are not aggregated (unevenly distributed) due to the aggregation action of the thixotropic agent.

The anti-glare film obtained by the method for producing an anti-glare film of the present invention is, for example, an optical member such as a polarizing plate, a liquid crystal panel, and an image display such as an LCD (liquid crystal display) or an OLED (organic EL display). It can be suitably used for an apparatus, its use is not limited, and it can be applied to a wide range of fields.

1 to 6, 12 Particles 10 Two-dot chain line 11 Antiglare layer 13 Thixotropic agent 14 Convex portion 20 Translucent substrate 21 Coating film 22 Coating liquid

Claims (13)

A method for producing an antiglare film, in which a coating liquid is applied to at least one surface of a light-transmitting substrate, and the coating liquid is cured to form an antiglare layer,
As the coating liquid, using a resin, particles, containing a thixotropic agent and a solvent,
The was coated on the translucent base includes the step of generating a shear on the coating liquid, by Rukoto allowed to localize the previous SL particles by the shear, to form the surface shape of the antiglare layer In addition, the antiglare layer is formed such that the haze value of the entire antiglare film according to JIS K 7136 (2000 version) is 0 to 3% ,
The surface shape of the antiglare layer is a shape having irregularities, method of manufacturing the anti-glare film according to claim Rukoto forming forms a convex portion of the uneven portion is unevenly distributed said particles. The method for producing an antiglare film according to claim 1, wherein the coating liquid satisfies at least one of the following conditions (I) and (II).

(I) In a linear approximation between the amount of the thixotropy-imparting agent and the Ti value in a range where the Ti value defined by the following formula (A) is 1.2 to 3.5, the contribution ratio R ² is 0.95 or more.
(II) When the Ti value defined by the following formula (A) is in the range of 1.2 to 3.5, a quadratic polynomial approximation y = the addition amount x of the thixotropy-imparting agent and the Ti value y = The quadratic coefficient a at ax ² + bx + c is a negative value.

Ti value = β1 / β2 (A)

In the above formula (A),
β1: viscosity at a shear rate of 20 (1 / s) β2: viscosity at a shear rate of 200 (1 / s) In the step of generating the shear, shear distance S of the coating liquid described above applied is defined by the following formula (B), and 0.005 × ¹⁰ -9 m~120 × range of ^{10 -9} m The method for producing an antiglare film according to claim 1, wherein:

S = ∫Vdt (B)

In the above formula (B),
S: Shear distance (m)
V: Shear rate (m / s)
t: Shear holding time (s)
And
The shear rate V is defined by the following equation (C):

V = kah ² / η (C)

In the above formula (C),
k: specific gravity of coating film (kg / m ³ )
a: acceleration (m / s ² )
h: Film thickness (m)
η: Coating viscosity (Pa · s)
It is. However, the acceleration a may change over time or may be constant. The shear rate V, characterized in that in the range of ^{0.05 × 10 -9 m / s~2.0 ×} 10 -9 m / s, the method for producing an antiglare film according to claim 3, wherein . The shear rate V, characterized in that in the range of ^{0.05 × 10 -9 m / s~1.0 ×} 10 -9 m / s, the method for producing an antiglare film according to claim 4, wherein . The method for producing an antiglare film according to any one of claims 3 to 5, wherein the shear holding time (t) is in a range of 0.1 to 60 s. The anti-glare film according to any one of claims 1 to 6, wherein the thixotropy-imparting agent is at least one selected from the group consisting of an organic clay, a polyolefin oxide, and a modified urea. Production method. The thickness (d) of the antiglare layer is in the range of 3 to 12 μm, and the particle diameter (D) of the particles is in the range of 2.5 to 10 μm. 8. The method for producing the antiglare film according to any one of items 7 to 7. 9. The antiglare film according to claim 8, wherein the relationship between the thickness (d) and the particle diameter (D) is in the range of 0.3 ≦ D / d ≦ 0.9. Method. In the coating liquid, the particles are contained in a range of 0.2 to 12 parts by weight, and the thixotropic agent is contained in a range of 0.2 to 5 parts by weight, based on 100 parts by weight of the resin. The method for producing an anti-glare film according to any one of claims 1 to 9, characterized in that: Polarizer, and a method for producing a polarizing plate having an antiglare film,
A method for manufacturing a polarizing plate, wherein the anti-glare film is manufactured by the method for manufacturing an anti-glare film according to any one of claims 1 to 10. A method for manufacturing an image display device including an antiglare film,
A method for manufacturing an image display device, wherein the anti-glare film is manufactured by the method for manufacturing an anti-glare film according to claim 1. A method for manufacturing an image display device including a polarizing plate,
The polarizing plate is a polarizer, and a polarizing plate having an antiglare film,
A method for manufacturing an image display device, wherein the anti-glare film is manufactured by the method for manufacturing an anti-glare film according to claim 1.