JP2019028154A - Laminate and method for manufacturing laminate - Google Patents

Abstract

To provide a laminate uniform in light diffusion properties, and a method for manufacturing the same.SOLUTION: The laminate is provided in which an over-laminate film is laminated on a light diffusion control film. The light diffusion control film has a predetermined internal structure, In the lamination surfaces of the laminate, when the direction of movement when forming the light diffusion control film is a long side direction; a direction vertical to the long side direction is a short side direction; the maximum of a phase difference Re (nm) measured in the short side direction of the over-laminate film is Re; and the minimum thereof is Re, a predetermined relational expression (1) is satisfied. (Re-Re)/(Re+Re)×100<35(%) (1).SELECTED DRAWING: Figure 2

Description

The present invention relates to a laminate and a method for producing the laminate.
In particular, it is a laminate of a light diffusion control film and an overlaminate film obtained by photocuring in a state where a coating layer made of a composition for light diffusion control film is laminated with an overlaminate film, The present invention relates to a laminate in which light diffusion characteristics are uniform regardless of the location in the film plane, and a method for producing such a laminate.

Conventionally, for example, use of a light diffusion control film has been proposed in the optical technical field to which a liquid crystal display device, a projection screen, and the like belong.
Such a light diffusion control film exhibits a certain light diffusion state in a specific incident angle range (hereinafter sometimes referred to as “light diffusion incident angle region”), and in an incident angle range that deviates from the light diffusion incident angle region. In this case, incident light is transmitted as it is, or has a light diffusion characteristic that shows a light diffusion state different from the light diffusion state in the light diffusion incident angle region.

  As such a light diffusion control film, various modes are known. In particular, a plurality of columnar objects having a relatively high refractive index are forested in a region having a relatively low refractive index in the film. A light diffusion control film having a column structure is widely used.

  Further, as another type of light diffusion control film, light having a louver structure in which a plurality of plate-like regions having different refractive indexes are alternately arranged along any one direction along the film surface in the film. Diffusion control films are widely used.

By the way, the light diffusion control film having such a column structure or louver structure is applied to a coating layer formed by coating a composition for a light diffusion control film containing two or more kinds of polymerizable compounds having different refractive indexes into a film shape. Thus, it is known that it can be obtained by irradiating active energy rays by a predetermined method.
In other words, light diffusion having a predetermined internal structure is achieved by irradiating a coating layer with a predetermined active energy ray whose traveling direction is controlled, and curing two or more kinds of polymerizable compounds in the coating layer while phase-separating them. A control film can be obtained.

However, when a predetermined active energy ray is directly applied to the coating layer, there has been a problem that it is difficult to form a predetermined internal structure all the way in the film thickness direction, that is, up to the upper surface of the film.
That is, although a predetermined internal structure can be formed in the lower part in the film thickness direction, there has been a problem that an internal structure unformed region occurs in the upper part.
Therefore, a technique for forming a predetermined internal structure up to the upper surface of the film without generating an internal structure unformed region has been disclosed (for example, see Patent Document 1).

That is, Patent Document 1 discloses a light irradiation mask bonding step for bonding a light irradiation mask having a haze value of 1.0 to 50.0% to one surface of a photocurable uncured resin composition layer, and light irradiation. After the mask bonding step, a curing step of curing the uncured resin composition layer by irradiating light through a light irradiation mask to form an anisotropic diffusion layer, and incident light A method for producing an anisotropic optical film in which the diffusivity changes depending on the angle is disclosed.
Further, the surface roughness of the light irradiation mask is set to 0.05 to 0.50 μm, and the oxygen transmission coefficient of the light irradiation mask is set to 1.0 × 10 ⁻¹¹ cm ³ (STP) cm / (cm ² · s · Pa) or less is also described.
That is, a technique for suppressing the occurrence of an internal structure non-formation region by photocuring a coating layer made of the light diffusion control film composition in a state where a predetermined overlaminate film is laminated is disclosed.

JP, 2006-194687, A (Claims)

However, even when the light irradiation mask described in Patent Document 1 is used, it is difficult to stably suppress the generation of the internal structure unformed region.
In particular, in a single continuous light diffusion control film having a width, there was a portion where an internal structure non-formation region did not occur, and a portion where it occurred. For this reason, there has been a problem in that the light diffusion characteristics also change depending on the incident position of light within the film surface, and the light diffusion characteristics are not uniform as a whole.

Therefore, the present inventors made extensive efforts in view of the above circumstances, and by setting the variation in the phase difference measured along the predetermined direction in the overlaminate film surface to a value within a predetermined range. The present invention has been completed by finding that the internal structure can be uniformly formed even when the internal structure unformed region does not occur or does not occur.
That is, an object of the present invention is a laminate of a light diffusion control film and an overlaminate film obtained by photocuring a coating layer comprising a composition for a light diffusion control film laminated with an overlaminate film. An object of the present invention is to provide a laminate in which the light diffusion characteristics of the light diffusion control film are uniform regardless of the location in the film plane, and a method for producing such a laminate.

According to the present invention, a laminate in which an overlaminate film is laminated on at least one surface of a light diffusion control film derived from the composition for light diffusion control film, wherein the light diffusion control film has a low refractive index. A plurality of high-refractive index regions in the region, the high-refractive index region has an internal structure extending in the thickness direction, and is within the stacking plane of the laminate, and the light diffusion control film The moving direction at the time of formation is the long direction, the direction perpendicular to the long direction is the short direction, and the maximum value of the phase difference Re (nm) measured along the short direction of the overlaminate film is Re _max When the minimum value is Re _min , a laminate that satisfies the following relational expression (1) is provided, and the above-described problems can be solved.
(Re _max −Re _min ) / (Re _max + Re _min ) × 100 <35 (%) (1)
That is, according to the laminate of the present invention, the dispersion of the phase difference Re measured along a predetermined direction in the overlaminate film surface is set to a value within a predetermined range. A laminate of an overlaminate film and a light diffusion control film whose light diffusion characteristics are uniform regardless of the location in the film plane is cured by laminating the overlaminate film on the applied layer. Can do.

Moreover, when comprising the laminated body of this invention, it is preferable to make the length in the short direction of an overlaminate film into the value within the range of 100-10000 mm.
By comprising in this way, the laminated body with sufficient length of a short direction can be obtained, and by extension, the light-diffusion control film with sufficient length of a short direction can be obtained.

Moreover, in constructing the laminate of the present invention, it is preferable to set the median value of the phase difference Re of the overlaminate film to a value within the range of 1000 to 3000 nm.
By comprising in this way, generation | occurrence | production of an internal structure non-formation area | region can be suppressed effectively in a light-diffusion control film.

Moreover, when comprising the laminated body of this invention, it is preferable to make the film thickness of an overlaminate film into the value within the range of 5-5000 micrometers.
By comprising in this way, the overlaminate film which satisfies the relational expression (1) more stably can be obtained.

In constructing the laminate of the present invention, as the internal structure of the light diffusion control film, a plurality of pillars having a relatively high refractive index are formed in the film thickness direction in a region having a relatively low refractive index. It is preferable to include a column structure.
By comprising in this way, the light-diffusion control film which has an isotropic light-diffusion characteristic can be obtained.

Further, in constituting the laminate of the present invention, as an internal structure in the light diffusion control film, a louver structure in which a plurality of plate-like regions having different refractive indexes are alternately arranged in any one direction along the film surface. It is preferable to include.
By comprising in this way, the light-diffusion control film which has an anisotropic light-diffusion characteristic can be obtained.

Another aspect of the present invention is a method for manufacturing a laminate, which includes the following steps (a) to (d).
(A) A step of preparing a composition for a light diffusion control film containing a high refractive index active energy ray curable component and a low refractive index active energy ray curable component (b) A film of the composition for a light diffusion control film on a process sheet (C) Laminating an overlaminate film satisfying the relational expression (1) with respect to the exposed surface of the coating layer (d) Overlaminating film while moving the coating layer In other words, according to the method for producing a laminate of the present invention, the overlaminate film has a phase difference measured along a predetermined direction in the plane. The variation in Re is set to a value within a predetermined range. And the coating layer which consists of a composition for light-diffusion control films is hardened | cured (photocured) by irradiating an active energy ray in the state which laminated | stacked the overlaminate film. As a result, it is possible to obtain a laminated body of a light diffusion control film having uniform light diffusion characteristics regardless of the location in the film plane and an overlaminate film.

FIG. 1A to FIG. 1B are diagrams provided for explaining the outline of the laminate of the present invention. FIGS. 2A to 2B are views for explaining an outline of a light diffusion control film having a column structure in the film. FIGS. 3A to 3B are diagrams for explaining incident angle dependency and isotropic light diffusion in a light diffusion control film having a column structure in the film. 4 (a) to 4 (d) are diagrams provided for explaining the internal structure of the light diffusion control film according to the present invention. 5 (a) to 5 (c) are diagrams for explaining the method for producing a laminate according to the present invention. FIG. 6 is a diagram provided for explaining the irradiation angle of the active energy ray. FIG. 7 is a diagram provided to illustrate the relationship between the position in the short direction of the overlaminate film in Example 1 and Comparative Example 1 and the phase difference Re. FIGS. 8A to 8C are diagrams provided to show cross-sectional photographs of the light diffusion control films in Examples 1 and 2 and Comparative Example 1. FIG. FIGS. 9A to 9B are diagrams provided to illustrate the relationship between the incident angle of the reference light with respect to the light diffusion control films in Examples 1 and 2 and Comparative Example 1, and the variable angle haze. 10A to 10B show the positions of the light diffusion control films in Examples 1 and 2 and Comparative Example 1 in the short direction, and the linearly transmitted light intensity P.A. It is a figure provided in order to show the relationship with T.

[First Embodiment]
In the first embodiment of the present invention, as shown in FIG. 1A, the overlaminate film 4 is laminated on at least one surface of the light diffusion control film 10 derived from the composition for light diffusion control film. It is the laminated body 100 which was made.
The light diffusion control film 10 has a plurality of high refractive index regions 12 in the low refractive index region 14, and the high refractive index region 12 has an internal structure 20 that extends in the thickness direction. In addition, the movement direction when forming the light diffusion control film 10 in the lamination surface of the laminate 100 is the long direction, the direction perpendicular to the long direction is the short direction, and the overlaminate film 4 The laminate is characterized by satisfying the following relational expression (1) when the maximum value of the phase difference Re (nm) measured along the short direction is Re _max and the minimum value is Re _min. .
(Re _max −Re _min ) / (Re _max + Re _min ) × 100 <35 (%) (1)

That is, it is a laminate 100 in which the overlaminate film 4 is laminated on at least one surface of the light diffusion control film 10, and the light diffusion control film 10 has a high refractive index curing component (high refractive active energy ray curing component). ) And a low refractive index curing component (low refractive index active energy ray curing component).
And in the light-diffusion control film as hardened | cured material, while having the internal structure 20 provided with the some area | region 12 with a relatively high refractive index in the area | region 14 with a relatively low refractive index, FIG. As shown in b), the moving direction MD of the coating layer 1 when the coating layer 1 derived from the composition for light diffusion control film is photocured is the longitudinal direction LD, and in the stacking plane of the laminate 100. The direction perpendicular to the long direction LD is the short direction SD, the maximum value of the phase difference Re (nm) measured along the short direction SD of the overlaminate film 4 is Re _max , and the minimum value is Re _min . When it does, it is the laminated body 100 satisfying the said relational expression (1).
Hereinafter, a first embodiment of the present invention will be specifically described with reference to the drawings as appropriate.
However, the composition for light diffusion control film and its curing mode will be described in the second embodiment.

1. Overlaminate film The overlaminate film in the present invention has a long moving direction MD of the coating layer 1 when photocuring the coating layer 1 derived from the composition for a light diffusion control film, as shown in FIG. The direction of the phase difference Re (°) measured along the short direction SD of the overlaminate film 4 is defined as the short direction SD, the direction perpendicular to the long direction LD in the laminating plane of the laminate. When the maximum value is Re _max and the minimum value is Re _min , the following relational expression (1) is satisfied.
(Re _max −Re _min ) / (Re _max + Re _min ) × 100 <35 (%) (1)

The reason for this is that when the dispersion value of the phase difference Re represented by the left side of the relational expression (1) reaches 35% or more, the internal structure of the light diffusion control film cured and formed via the overlaminate film is It is because it changes excessively for every location in the surface. Therefore, it is difficult to maintain the uniformity of the light diffusion characteristics in the film plane.
That is, the upper limit value of the variation of the phase difference Re represented by the left side of the relational expression (1) is more preferably 30% or less, further preferably 25% or less, and 10% or less. A value is particularly preferable.
Further, the smaller the dispersion value of the phase difference Re represented by the left side of the relational expression (1), the better. However, when the value is too small, the range of material selection is excessively limited.
Therefore, the lower limit value of the variation in the phase difference Re represented by the left side of the relational expression (1) is preferably 0.1% or more, more preferably 0.5% or more. More preferably, the value is at least%.
In calculating the dispersion of the phase difference Re, it is preferable to measure the phase difference Re at 5 to 100 locations at equal intervals along the short direction SD of the overlaminate film (about the median value of the phase difference Re described later) The same).
Further, as is clear from FIG. 1B, the long direction LD and the short direction SD of the overlaminate film coincide with the long direction LD and the short direction SD of the laminate, and the light diffusion control that constitutes the laminate. This also coincides with the long direction LD and the short direction SD of the film and the process sheet.
The phase difference Re can be adjusted by a film stretching process, but it is particularly preferable to adjust by a biaxial stretching.

Here, the relationship between the variation in the phase difference Re in the overlaminate film and the uniformity in the light diffusion characteristics of the light diffusion control film will be briefly described.
That is, it is considered that there is a close relationship between the vibration direction of the irradiated active energy ray and the formed refractive index distribution structure. Further, when the active energy ray is irradiated onto the overlaminate film, vibrations in the long direction LD and the short direction SD of the overlaminate film are affected differently by the phase difference of the overlaminate film. And it is estimated that the produced shift changes the vibration direction of the active energy ray.
As a result, it is estimated that the light diffusion characteristics of the light diffusion control film formed below the overlaminate film are greatly influenced by the phase difference Re of the overlaminate film. For this reason, when the phase difference Re varies in the short direction SD, it is estimated that the light diffusion characteristic varies correspondingly.

Moreover, it is preferable to make the median value of the phase difference Re of the overlaminate film within a range of 1000 to 3000 nm.
This is because when the median value of the phase difference Re is less than 1000 nm, the material selection may be difficult because the film has an excessively low phase difference Re.
On the other hand, if the median value of the phase difference Re exceeds 3000 nm, the material selection may be difficult because the film has an excessively high phase difference Re.
Therefore, the lower limit value of the median value of the phase difference Re is more preferably 1100 nm or more, and even more preferably 1200 nm or more.
In addition, the upper limit value of the median value of the phase difference Re is more preferably 2800 nm or less, and further preferably 2900 nm or less.

Moreover, it is preferable to make arithmetic mean roughness (Ra) in the active energy ray irradiation side surface of an overlaminate film into the value within the range of 1-200 nm.
When Ra has a value of less than 1 nm, the films may come into close contact with each other when the overlaminate film is unwound, and vibrations when peeling off may increase. For this reason, there exists a possibility that the said vibration may conduct to an active energy ray irradiation part, and may reduce the precision of internal structure formation of a light diffusion control film.
On the other hand, if Ra exceeds 200 nm, the surface shape is too large, and active energy rays are diffused, which may hinder structure formation.
Therefore, the lower limit value of the arithmetic average roughness (Ra) of the overlaminate film is more preferably 5 nm or more, and further preferably 10 nm or more.
Further, the upper limit value of the arithmetic average roughness (Ra) of the overlaminate film is more preferably 100 nm or less, further preferably 40 nm or less, and particularly preferably 30 nm or less.
The arithmetic average roughness (Ra) as one of the surface roughnesses can be measured in conformity with JIS B 0601: 2001, but can also be measured in accordance with ANSI B46.1. it can.

Moreover, it is preferable to make the maximum peak height (Rp) of an overlaminate film into the value within the range of 20-5000 nm.
The reason for this is that when the Rp is less than 20 nm, the films are in close contact with each other when the overlaminate film is unwound, and vibrations when peeling may increase. For this reason, there exists a possibility that the said vibration may conduct to an active energy ray irradiation part, and may reduce the precision of internal structure formation of a light diffusion control film. On the other hand, when Rp is a value exceeding 5000 nm, the surface shape is too large, and active energy rays are diffused, which may hinder structure formation.
Therefore, the lower limit value of the maximum peak height (Rp) of the overlaminate film is more preferably 50 nm or more, further preferably 100 nm or more, and particularly preferably 300 nm or more.
Further, the upper limit value of the maximum peak height (Rp) of the overlaminate film is more preferably 2000 nm or less, further preferably 1000 nm or less, and particularly preferably 600 nm or less.
The maximum peak height (Rp) as one of the surface roughnesses can be measured in conformity with JIS B 0601: 2001, but can also be measured in conformity with ANSI B46.1. .

Moreover, it is preferable to make the haze of an overlaminate film into the value within the range of 1-25%.
The reason for this is that when the haze is less than 1%, the films are in close contact with each other when the overlaminate film is unwound, and vibrations when peeling may increase. For this reason, there exists a possibility that the said vibration may conduct to an active energy ray irradiation part, and may reduce the precision of internal structure formation of a light diffusion control film.
On the other hand, if the haze exceeds 25%, the surface shape is too large, and active energy rays are diffused, which may hinder structure formation.
Therefore, the lower limit value of the haze of the overlaminate film is more preferably 3% or more, and further preferably 5% or more.
Further, the upper limit value of the haze of the overlaminate film is more preferably 20% or less, and further preferably 15% or less.

Moreover, it is preferable to make the total light transmittance of an overlaminate film into the value within the range of 70 to 97%.
The reason for this is that when the total light transmittance is less than 70%, the transmissivity of the active energy ray is excessively lowered, making it difficult to efficiently form a predetermined internal structure in the light diffusion control film. Because there is. On the other hand, when the total light transmittance exceeds 97%, the range of material selection is excessively limited.
Accordingly, the lower limit value of the total light transmittance of the overlaminate film is more preferably 75% or more, and further preferably 80% or more.
Further, the upper limit value of the total light transmittance of the overlaminate film is more preferably 95% or less, and even more preferably 93% or less.

The material of the overlaminate film is not particularly limited, but is a polyethylene terephthalate film, a triacetyl cellulose film, a cycloolefin polymer film, a cyclic olefin film, an ionomer film, a polyethylene film, a polyvinyl chloride film, a polychlorinated film. Vinylidene film, polyvinyl alcohol film, polypropylene film, polyester film, polycarbonate film, polystyrene film, polyacrylonitrile film, ethylene vinyl acetate copolymer film, ethylene-vinyl alcohol copolymer film, ethylene-methacrylic acid copolymer film, nylon Film, cellophane, etc., and one of these may be used alone, or two or more It may be used in conjunction seen.
This is because, with these materials, an overlaminate film that satisfies the relational expression (1) can be obtained more stably.

Moreover, it is preferable to set it as the value within the range of the length of 100-10000 mm in the short direction of an overlaminate film.
This is because when the length in the short direction is less than 100 mm, the length in the short direction of the light diffusion control film constituting the laminate is also less than 100 mm, which is practically required for the light diffusion control film. This is because the size may not be satisfied.
On the other hand, if the length in the short direction exceeds 10,000 mm, it may be difficult to irradiate uniform active energy rays in the width direction.
Accordingly, the lower limit value of the length in the short direction of the overlaminate film is more preferably 200 mm or more, further preferably 300 mm or more, and particularly preferably 600 mm or more.
The upper limit of the length of the overlaminate film in the short direction is more preferably 8000 mm or less, further preferably 6000 mm or less, and particularly preferably 3000 mm or less.

Moreover, it is preferable to make the film thickness of an overlaminate film into the value within the range of 5-5000 micrometers.
The reason for this is that when the film thickness is less than 5 μm, handling becomes difficult and wrinkles may occur during pasting of the overlaminate film.
On the other hand, when the film thickness exceeds 5000 μm, it is difficult to handle and wrinkles may occur during overlaminate film conveyance.
Therefore, the lower limit value of the film thickness of the overlaminate film is more preferably 10 μm or more, and further preferably 30 μm or more.
The upper limit value of the film thickness of the overlaminate film is more preferably 1000 μm or less, further preferably 400 μm or less, and even more preferably 100 μm or less.
In addition, you may apply | coat release agents, such as a silicone resin, and may provide a peeling layer in the surface of the side which contacts a light-diffusion control film among both surfaces of an overlaminate film.

2. Light Diffusion Control Film (1) Basic Principle of Light Diffusion in Light Diffusion Control Film First, as an example of the light diffusion control film in the present invention, a column structure 20a is provided in the film using FIGS. The isotropic light diffusion control film 10a having diffusibility will be described.
First, FIG. 2 (a) shows a plan view of an isotropic light diffusion control film 10a having a column structure 20a in the film, and FIG. 2 (b) shows an isotropic light diffusion shown in FIG. 2 (a). A cross-sectional view of the isotropic light diffusion control film 10a when the control film 10a is cut in the vertical direction along the dotted line AA and the cut surface is viewed from the arrow direction is shown.
3A shows an overall view of an isotropic light diffusion control film 10a having a column structure 20a in the film, and FIG. 3B shows an isotropic light diffusion control film 10a shown in FIG. The diffusion condition of the light diffused by (the shape of the spread of the diffused light) is shown.
As shown in the plan view of FIG. 2A, the isotropic light diffusion control film 10a has a column structure 20a including a columnar body 12a having a relatively high refractive index and a region 14a having a relatively low refractive index. Have.
Further, as shown in the sectional view of FIG. 2B, the isotropic light diffusion control film 10a has a columnar body 12a having a relatively high refractive index and a region 14a having a relatively low refractive index. The plurality of columnar objects 12a having a relatively high refractive index are arranged in a forested state so as to have a predetermined interval.

Thereby, as shown to Fig.3 (a), it is estimated that the incident light whose incident angle (theta) 1 is in a light-diffusion incident angle area | region is diffused by the isotropic light-diffusion control film 10a.
That is, as shown in FIG. 2B, the incident angle of the incident light with respect to the isotropic light diffusion control film 10a is a value within a predetermined angle range from parallel to the boundary surface 20a ′ of the column structure 20a, that is, light When the value is within the diffuse incident angle region, the incident light (52, 54) follows the film thickness direction while changing the direction inside the columnar body 12a having a relatively high refractive index in the column structure. Thus, it is presumed that the light traveling direction on the light exit surface side is not uniform.
As a result, when the incident angle is within the light diffusion incident angle region, it is estimated that the incident light is diffused by the isotropic light diffusion control film 10a and becomes diffused light (52 ′, 54 ′).
On the other hand, when the incident angle of the incident light with respect to the isotropic light diffusion control film 10a deviates from the light diffusion incident angle region, the incident light 56 is diffused by the isotropic light diffusion control film 10a as shown in FIG. It is estimated that the light passes through as it is and becomes transmitted light 56 '.

Based on the basic principle described above, the isotropic light diffusion control film 10a provided with the column structure 20a can exhibit incident angle dependency in light transmission and diffusion as shown in FIG. 3A, for example. .
Further, as shown in FIG. 2B, the isotropic light diffusion control film 10a provided with the column structure 20a normally has “isotropic” as its light diffusion characteristics.
Here, in the present invention, “isotropic” means that, as shown in FIG. 3B, when incident light is diffused by a film, the diffused outgoing light is in a plane parallel to the film (in plan view). In other words, the light diffusion state does not change depending on the direction in the same plane.
More specifically, as shown in FIG. 3A, when the incident light is diffused by the isotropic light diffusion control film 10a, the diffused state of the emitted light is circular in a plane parallel to the film. It becomes a shape.

In addition, as shown in FIG. 3A, the isotropic light diffusion control film has a different incident angle θ1 when the incident angle θ1 of incident light is included in the light diffusion incident angle region. Almost the same light diffusion can be performed on the light exit surface side.
Therefore, it can be said that the isotropic light diffusion control film has a light condensing function that concentrates light at a predetermined location.
In addition, the direction change of the incident light inside the columnar body 12a in the column structure is not only a step index type in which the direction changes linearly and zigzag by total reflection as shown in FIG. In some cases, the gradient index type changes direction.

In addition, if the internal structure which the light-diffusion control film of this invention has is a high refractive index area | region and a low refractive index area | region, it will not be restrict | limited to the column structure mentioned above.
That is, in the technical field of the light diffusion control film, if it is an internal structure that can be formed by phase separation conventionally known, it can be similarly formed in the light diffusion control film of the present invention.
For example, as shown in FIG. 4A, there is a louver structure 20b in which a plurality of plate-like regions (12b, 14b) having different refractive indexes are alternately arranged along any one direction along the film surface. May be.
Or the columnar thing as shown in FIG.4 (b) may be the bending column structure 20c which has the bending part 16 in the intermediate point along a film film thickness direction.
Alternatively, as shown in FIG. 4 (c), a plurality of flaky objects 12d having a relatively high refractive index in a region 14d having a relatively low refractive index are arranged along any one direction along the film surface. The predetermined internal structure 20d may be arranged in a plurality of rows.
Or the combination of the louver structure 20b and the column structure 20a as shown in FIG.4 (d) may be sufficient.
That is, there are a wide variety of internal structures known in the technical field of light diffusion control films, but the light diffusion control film in the present invention may be any of those internal structures.

In any internal structure, the basic principle of light diffusion is the same as in the column structure 20a.
However, due to the form of each internal structure, a difference occurs in the shape of the spread of diffused light.
For example, in the case of the louver structure 20b shown in FIG. 4 (a), rod-like diffused light is generated in a plan view in which anisotropic light is diffused. In the case of the bent column structure 20c shown in FIG. Part of the light diffused in the isotropic light produces diffused light that is further isotropically diffused below the bent portion.
In addition, in the case of the predetermined internal structure 20d shown in FIG. 4C, since it is a hybrid type of the louver structure 20b and the column structure 20a, elliptical diffused light is generated in plan view, and the louver shown in FIG. In the case of the combination of the structure 20b and the column structure 20a, a part of the light diffused by the column structure 20a is further diffused by the louver structure 20b, so that bullet-shaped diffused light is generated in plan view.

(2) Internal structure The internal structure in the light diffusion control film of the present invention is not particularly limited as long as it includes a high refractive index region and a low refractive index region and can obtain light diffusion characteristics. It can be set as various aspects, such as a structure and a louver structure.
Hereinafter, the column structure will be described as an example, but other internal structures such as a louver structure can be applied to the contents of the column structure.

  As shown in FIGS. 2A to 2B, the column structure 20a is an internal structure for diffusing incident light isotropically. Specifically, the refractive index is in a region where the refractive index is relatively low. It is an internal structure made up of a plurality of columnar objects that are relatively high.

(2) -1 Refractive index The difference between the refractive index of a region having a relatively low refractive index in the column structure and the refractive index of a plurality of columnar objects having a relatively high refractive index is set to a value of 0.01 or more. Is preferred.
The reason for this is that when the difference in refractive index is a value of 0.01 or more, the angle range at which incident light is totally reflected in the column structure is narrowed, and the incident angle dependency may be excessively reduced. It is.
Therefore, the lower limit of the difference in refractive index is more preferably 0.03 or more, and further preferably 0.1 or more.
In addition, although the difference of this refractive index is so preferable that it is large, from a viewpoint of selecting the material which can form a column structure, about 0.3 is considered to be an upper limit.

(2) -2 Maximum diameter In addition, in the column structure 20a as shown in FIGS. 2A to 2B, the maximum diameter in the cross section of the columnar object is preferably set to a value within the range of 0.1 to 15 μm. .
This is because when the maximum diameter is less than 0.1 μm, it may be difficult to exhibit light diffusion characteristics regardless of the incident angle of incident light. On the other hand, when the maximum diameter exceeds 15 μm, the light traveling straight in the column structure increases, and the uniformity of the diffused light may decrease.
Therefore, in the column structure, the lower limit value of the maximum value is more preferably 0.5 μm or more, and further preferably 1 μm or more.
In the column structure, the upper limit value of the maximum value is more preferably 10 μm or less, and further preferably 5 μm or less.
In addition, although it does not specifically limit about the cross-sectional shape of a columnar thing, For example, it is preferable to set it as a circle, an ellipse, a polygon, an irregular shape, etc.
Moreover, the cross section of a columnar thing means the cross section cut | disconnected by the surface parallel to the film surface.
In addition, the maximum diameter and length of the columnar object can be measured by observing with an optical digital microscope.
Moreover, the numerical range of the maximum diameter described above applies similarly to the distance between the columnar objects.

(2) -3 Thickness Moreover, it is preferable to set the thickness (length in the film thickness direction) of the column structure 20a as shown in FIG. 2B to a value within the range of 10 to 700 μm.
This is because when the thickness is less than 10 μm, incident light that goes straight through the column structure increases, and it may be difficult to obtain a sufficient range of light diffusion characteristics. On the other hand, when the thickness exceeds 700 μm, when the column structure is formed by irradiating the composition for light diffusion control film with active energy rays, photopolymerization is caused by the initially formed column structure. This is because the traveling direction diffuses and it may be difficult to form a desired column structure.
Accordingly, the lower limit value of the thickness of the column structure is more preferably 30 μm or more, and further preferably 50 μm or more.
Further, the upper limit value of the thickness of the column structure is more preferably set to 200 μm or less, and further preferably set to 100 μm or less.
Note that the “range of light diffusion characteristics” means a range of incident angles indicating a light diffusion characteristic and a range of spread of diffused light.

(2) -4 Inclination angle Moreover, as shown in FIG.2 (b), in the column structure 20a, the columnar object 12a should stand by a fixed inclination angle with respect to the film thickness direction of a light-diffusion control film. Is preferred.
The reason for this is that by making the inclination angle of the columnar object constant, incident light can be more stably reflected in the column structure, and the incident angle dependency derived from the column structure can be further improved. .
More specifically, in the column structure, the inclination angle with respect to the normal of the film surface of the columnar material is preferably set to a value in the range of 0 to 80 °.
The reason for this is that when the inclination angle exceeds 80 °, the absolute value of the incident angle of the active energy ray increases accordingly, so that the ratio of the reflection of the active energy ray at the interface between the air and the coating layer increases. This is because it is necessary to irradiate active energy rays with higher illuminance when forming the column structure.
Therefore, the upper limit value of the inclination angle is more preferably 60 ° or less, and further preferably 40 ° or less.
The inclination angle is normal to the film surface, which is measured in a cross section when the film is cut by a plane perpendicular to the film surface and cut in two along the axis line. Means the angle on the narrow side of the angle formed with the top of the columnar object.

(3) Film thickness Moreover, it is preferable to make the film thickness of the light-diffusion control film in this invention into the value within the range of 10-700 micrometers.
The reason for this is that when the film thickness of the light diffusion control film is less than 10 μm, the incident light traveling straight in the column structure increases, and it may be difficult to exhibit predetermined light diffusion characteristics. On the other hand, when the thickness of the light diffusion control film exceeds 700 μm, when the column structure is formed by irradiating the composition for light diffusion control film with active energy rays, the column structure formed in the initial stage is formed. This is because the traveling direction of photopolymerization may be diffused by this, and it may be difficult to form a desired column structure. In addition, when applied to a display or the like, the display image may be easily blurred.
Accordingly, the lower limit of the film thickness of the light diffusion control film is more preferably 30 μm or more, and further preferably 50 μm or more.
On the other hand, the upper limit of the film thickness of the light diffusion control film is more preferably set to 300 μm or less, and further preferably set to 100 μm or less.

(4) Characteristics In addition, regarding the characteristics of the light diffusion control film in the present invention, it is preferable to set the width of the incident angle region having a haze of 70% or more to a value of 60 ° or more.
By limiting the width of the predetermined incident angle region in this way, incident light can be taken in efficiently and diffused uniformly, so that the brightness of the diffused light may be improved.
Accordingly, the width of the incident angle region having a haze of 70% or more is preferably set to a value of 80 ° or more, and more preferably set to a value of 100 ° or more.

Further, regarding the characteristics of the light diffusion control film in the present invention, the linear transmitted light intensity P.E. when irradiated with incident light tilted 60 ° in a direction further away from the incident angle region with the normal direction of the film surface being 0 °. It is preferable to set the median value of T within a range of 0.1 to 99%.
The reason for this is that when the median value is less than 0.1%, the transmittance of the entire film may deteriorate.
On the other hand, when the median value exceeds 99%, the incident angle region may be insufficient.
Accordingly, the lower limit of the median value is more preferably 1% or more, and further preferably 5% or more.
Further, the upper limit of the median value is more preferably 50% or less, and further preferably 15% or less.
The linear transmitted light intensity is expressed as a percentage by dividing the intensity of outgoing light emitted at the same angle as the incident light by the intensity of the entire incident light.

Further, regarding the characteristics of the light diffusion control film in the present invention, the linear transmitted light intensity P.I. The variation in T is preferably set to a value in the range of 0.1 to 3.8%.
The reason for this is that control may be difficult when the variation is less than 0.1%.
On the other hand, when the variation exceeds 3.8%, light and shade may occur in the light diffusion state.
Therefore, the lower limit of such variation is more preferably 1% or more, and further preferably 2% or more.
Further, the upper limit of the median value is more preferably 3.5% or less, and further preferably 2.8% or less.

3. Process sheet Moreover, as shown to Fig.1 (a), the laminated body 100 of this invention is one surface of the light-diffusion control film 10, Comprising: On the opposite side to the side by which the overlaminate film 4 is laminated | stacked. The process sheet 2 may be laminated on the surface.
Thus, the light diffusion control film can be effectively protected by sandwiching both surfaces of the light diffusion control film with the overlaminate film and the process sheet.
Here, a process sheet | seat is a sheet | seat with which the composition for light diffusion control films is apply | coated when manufacturing a laminated body.
As the process sheet, a normal release film can be used, for example, a polyester film such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, or a polyolefin film such as polypropylene or polyethylene. The thing which apply | coated the agent and provided the peeling layer is mentioned.
In addition, it is preferable that the film thickness of this process sheet | seat is normally set to the value within the range of 20-150 micrometers.

[Second Embodiment]
2nd Embodiment of this invention is a manufacturing method of the laminated body as 1st Embodiment, Comprising: The manufacturing method of the laminated body characterized by including the following process (a)-(d).
(A) A step of preparing a composition for a light diffusion control film containing a high refractive index active energy ray curable component and a low refractive index active energy ray curable component (b) A film of the composition for a light diffusion control film on a process sheet (C) Laminating an overlaminate film satisfying the relational expression (1) with respect to the exposed surface of the coating layer (d) Overlaminating film while moving the coating layer The step of irradiating the coating layer with active energy rays through the second embodiment Hereinafter, the second embodiment of the present invention will be specifically described with reference to the drawings as appropriate, centering on differences from the first embodiment. explain.

1. Step (a): Step of Preparing a Composition for Light Diffusion Control Film Step (a) is a step of preparing a predetermined composition for light diffusion control film.
More specifically, it is a step of mixing the components (A) to (B) described below and other components as desired.
In mixing, the mixture may be stirred as it is at room temperature. However, from the viewpoint of improving uniformity, for example, stirring is performed under a heating condition of 40 to 80 ° C. to obtain a uniform mixed solution. preferable.
Moreover, it is also preferable to add a dilution solvent so that it may become the desired viscosity suitable for coating.

(1) (A) component: High refractive index active energy ray curing component The composition for light diffusion control film in the present invention comprises a high refractive index curing component (high refractive index active energy ray curing component) as the (A) component. It is characterized by including.
The reason for this is that by including a high refractive index active energy component as the component (A), the polymerization rate is reduced with the low refractive index curing component (low refractive index active energy ray curing component) as the component (B) described later. This is because a predetermined difference is caused and the components (A) and (B) can be cured while being efficiently phase-separated by inhibiting both components from being uniformly copolymerized.
As a result, a predetermined internal structure such as a column structure or a louver structure is formed at the time of curing, even though the composition is uniform before curing, so that the light diffusion control film as a cured product obtained On the other hand, it is possible to impart excellent light diffusion characteristics that can diffuse incident light efficiently.

(1) -1 Refractive index (A) It is preferable to make the refractive index of the high refractive index active energy ray hardening component as a component into the value within the range of 1.5-1.65.
This is because when the refractive index of the component (A) is less than 1.5, the difference between the refractive index of the low refractive index active energy ray curing component as the component (B) becomes too small, and effective light This is because it may be difficult to obtain diffusion characteristics. On the other hand, when the refractive index of the component (A) exceeds 1.65, the difference with the refractive index of the component (B) increases, but even an apparent compatibility state with the component (B) is formed. This is because it may be difficult.
Therefore, the lower limit value of the refractive index of the component (A) is more preferably 1.55 or more, and further preferably 1.56 or more.
Further, the upper limit value of the refractive index of the component (A) is more preferably 1.6 or less, and further preferably 1.59 or less.
In addition, the refractive index of (A) component mentioned above means the refractive index of (A) component before hardening by light irradiation.
The refractive index can be measured according to, for example, JIS K0062: 1992.

(1) -2 Types The type of the component (A) is not particularly limited, but is preferably a (meth) acrylic ester containing a plurality of aromatic rings.
This is because such a compound can be photocured while more efficiently phase-separating the component (A) and the component (B), and more excellent light diffusion characteristics can be obtained. is there.
Examples of such compounds include biphenyl (meth) acrylate, naphthyl (meth) acrylate, anthracyl (meth) acrylate, benzylphenyl (meth) acrylate, biphenyloxyalkyl (meth) acrylate, (meth) Naphtyloxyalkyl acrylate, anthracyloxyalkyl (meth) acrylate, benzylphenyloxyalkyl (meth) acrylate, o-phenoxybenzyl (meth) acrylate, m-phenoxybenzyl (meth) acrylate, p-phenoxybenzyl (meth) ) Acrylates or the like, or those partially substituted with halogen, alkyl, alkoxy, halogenated alkyl, or the like.
“(Meth) acrylic acid” means both acrylic acid and methacrylic acid.

  The component (A) preferably includes a compound containing a biphenyl ring, and more preferably includes a biphenyl compound represented by the following general formula (1).

(In General Formula (1), R < ¹ > -R < ¹⁰ > is respectively independent, At least 1 of R < ¹ > -R < ¹⁰ > is a substituent represented by following General formula (2), The remainder is A hydrogen atom, a hydroxyl group, a carboxyl group, an alkyl group, an alkoxy group, a halogenated alkyl group, a hydroxyalkyl group, a carboxyalkyl group, or a halogen atom substituent.)

(In the general formula (2), R ¹¹ is a hydrogen atom or a methyl group, the carbon number n is an integer of 1 to 4, and the repeating number m is an integer of 1 to 10.)

The reason for this is that by including a biphenyl compound having a specific structure as the component (A), a predetermined difference is caused in the polymerization rate of the component (A) and the component (B), and the component (A) and the component (B) This is because it is estimated that the compatibility between the two components can be reduced by reducing the compatibility with the component to a predetermined range.
Further, the refractive index of the region having a relatively high refractive index derived from the component (A) is increased, and the difference from the refractive index of the region having a relatively low refractive index derived from the component (B) is set to a predetermined value or more. Can be adjusted more easily.

  Moreover, as a specific example of the biphenyl compound represented by General formula (1), the compound represented by following formula (3)-(4) can be mentioned preferably.

(2) (B) component: low refractive index active energy ray hardening component The composition for light diffusion control films in this invention is characterized by including a low refractive index active energy ray hardening component as (B) component.
The reason for this is that by including a low refractive index active energy ray-curable component as the component (B), a predetermined difference is caused in the polymerization rate with the high refractive index active energy ray-curable component as the component (A) described above. This is because the components (A) and (B) can be photocured while efficiently phase-separating by suppressing the uniform copolymerization of both components.
As a result, a predetermined internal structure such as a column structure or a louver structure is formed at the time of photocuring even though the composition is uniform before photocuring. The control film can be provided with excellent light diffusing characteristics capable of efficiently diffusing incident light.

(2) -1 Refractive index (B) It is preferable to make the refractive index of the low refractive index active energy ray hardening component as a component into the value within the range of 1.4-1.5.
The reason for this is that when the refractive index of the component (B) is less than 1.4, the difference from the refractive index of the component (A) increases, but the compatibility with the component (A) is extremely deteriorated, This is because it may be difficult to form a predetermined internal structure. On the other hand, if the refractive index of the component (B) exceeds 1.5, the difference from the refractive index of the component (A) becomes too small, and it may be difficult to obtain desired light diffusion characteristics. Because there is.
Therefore, the lower limit value of the refractive index of the component (B) is more preferably 1.45 or more, and further preferably 1.46 or more.
Further, the upper limit value of the refractive index of the component (B) is more preferably 1.49 or less, and further preferably 1.48 or less.
In addition, the refractive index of (B) component mentioned above means the refractive index of (B) component before hardening by light irradiation. The refractive index can be measured according to, for example, JIS K0062: 1992 as described above.

The difference between the refractive index of the component (A) and the refractive index of the component (B) is preferably set to a value of 0.01 or more.
The reason for this is that when the difference in refractive index is less than 0.01, the angle range in which incident light is totally reflected within a predetermined internal structure is narrowed, so that the range of light diffusion characteristics becomes excessively narrow. Because there is. On the other hand, if the difference in refractive index is an excessively large value, the compatibility between the component (A) and the component (B) may be deteriorated so that it may be difficult to form a predetermined internal structure. is there.
Accordingly, the lower limit value of the difference between the refractive index of the component (A) and the refractive index of the component (B) is more preferably 0.05 or more, and further preferably 0.1 or more. preferable.
The upper limit of the difference between the refractive index of the component (A) and the refractive index of the component (B) is more preferably 0.5 or less, and further preferably 0.2 or less. preferable.
In addition, the refractive index of (A) component and (B) component here means the refractive index of (A) component and (B) component before hardening by light irradiation.

(2) -2 Types The type of the component (B) is not particularly limited. For example, urethane (meth) acrylate, (meth) acrylic polymer having a (meth) acryloyl group in the side chain, ( Examples thereof include a (meth) acryloyl group-containing silicone resin and an unsaturated polyester resin, and urethane (meth) acrylate is particularly preferable.
The reason for this is that if urethane (meth) acrylate is used, it can be photocured while further efficiently separating the components (A) and (B), and more excellent light diffusion characteristics can be obtained. It is.
In addition, (meth) acrylate means both acrylate and methacrylate.

The urethane (meth) acrylate is (B1) a compound containing at least two isocyanate groups, (B2) a polyol compound, preferably a diol compound, particularly preferably a polyalkylene glycol, and (B3) a hydroxyalkyl (meth). Formed from acrylate.
The component (B) includes an oligomer having a urethane bond repeating unit.
Among these, as the compound containing at least two isocyanate groups as the component (B1), for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate 1,4-xylylene diisocyanate, aromatic polyisocyanates such as methylene diphenyl 4,4′-diisocyanate (MDI), aliphatic polyisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate (IPDI) , Cycloaliphatic polyisocyanates such as hydrogenated diphenylmethane diisocyanate, and their biuret, isocyanurate, and low molecular active hydrogen such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, castor oil, etc. Containing compounds Examples thereof include adducts (for example, xylylene diisocyanate trifunctional adducts) that are reactants.

Among the components that form urethane (meth) acrylate, examples of the polyalkylene glycol that is the component (B2) include polyethylene glycol, polypropylene glycol, polybutylene glycol, polyhexylene glycol, and the like. Particularly preferred is glycol.
The reason for this is that if polypropylene glycol is cured, it becomes a good soft segment in the cured product when the component (B) is cured, and effectively improves the handling and mounting properties of the resulting light diffusion control film. Because it can.
The weight average molecular weight of the component (B) can be adjusted mainly by the weight average molecular weight of the component (B2). Here, the weight average molecular weight of (B2) component is 2300-19500 normally, Preferably it is 4300-14300, Most preferably, it is 6300-12300.

Moreover, as a hydroxyalkyl (meth) acrylate which is a (B3) component among the components which form urethane (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3 -Hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, etc. are mentioned.
In addition, from the viewpoint of reducing the polymerization rate of the obtained urethane (meth) acrylate and more efficiently forming a predetermined internal structure, hydroxyalkyl methacrylate is more preferable, and 2-hydroxyethyl methacrylate is particularly preferable. Is more preferable.

(2) -3 Blending amount Moreover, when the total amount of the (A) component and the (B) component is 100 parts by weight, the blending ratio of the (A) component and the (B) component ((A) component : (B) component (weight ratio)) is preferably set to a value within the range of 20:80 to 80:20.
That is, when the total amount of the component (A) and the component (B) is 100 parts by weight, the blending ratio of the component (B) is preferably set to a value in the range of 20 to 80 parts by weight.
The reason for this is that when the blending ratio of the component (B) is less than 20 parts by weight, the width of the region where the refractive index derived from the component (A) is relatively high is the refractive index derived from the component (B). This is because the width of the relatively low region is excessively large and it may be difficult to obtain good light diffusion characteristics. On the other hand, when the blending ratio of the component (B) exceeds 80 parts by weight, the ratio of the component (A) to the component (B) decreases, and the refractive index derived from the component (A) is relatively This is because the width of the high region is excessively small compared to the width of the region having a relatively low refractive index derived from the component (B), and it may be difficult to obtain good light diffusion characteristics. .
Therefore, when the total amount of the component (A) and the component (B) is 100 parts by weight, the lower limit value of the blending ratio of the component (B) is more preferably set to 40 parts by weight or more. More preferably, the value is at least part.
Further, when the total amount of the component (A) and the component (B) is 100 parts by weight, the upper limit value of the blending ratio of the component (B) is more preferably 70 parts by weight or less, and 65 parts by weight. More preferably, the following values are used.

(3) Component (C): Photopolymerization Initiator Moreover, in the composition for light diffusion control film, it is preferable to contain a photopolymerization initiator as the component (C).
The reason for this is that by containing a photopolymerization initiator, when the composition for light diffusion control film is irradiated with active energy rays, the component (A) and the component (B) are more efficiently phase separated. This is because photo-curing can be achieved while further excellent light diffusion characteristics can be obtained.

  Here, as the photopolymerization initiator, for example, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2- Phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) Phenyl] -2-morpholino-propan-1-one, 4- (2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4-diethi Aminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tertiarybutylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethyl ketal, acetophenone dimethyl ketal, p-dimethylamine benzoate, oligo [2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propane] and the like Of these, one of these may be used alone, or two or more may be used in combination.

Moreover, as a compounding quantity of (C) component, it is preferable to set it as the value within the range of 0.2-20 weight part with respect to 100 weight part of total amounts of (A) component and (B) component.
The reason for this is that when the amount of the component (C) is less than 0.2 parts by weight, the polymerization starting point becomes poor, and therefore it is difficult to sufficiently cure the composition for a light diffusion control film. Because there is. On the other hand, when the blending amount of the component (C) exceeds 20 parts by weight, the light diffusion control film may be easily yellowed or deteriorated in durability.
Therefore, the lower limit of the amount of component (C) is more preferably 0.5 parts by weight or more, and even more preferably 1 part by weight or more.
Further, the upper limit of the amount of component (C) is more preferably 15 parts by weight or less, and even more preferably 10 parts by weight or less.

(4) Other Additives Other additives can be appropriately blended within the range not impairing the effects of the present invention.
Examples of other additives include an antioxidant, an antistatic agent, a polymerization accelerator, a polymerization inhibitor, an infrared absorber, a plasticizer, a diluting solvent, and a leveling agent.
In general, the content of other additives is preferably a total amount of the component (A) and the component (B) (value within a range of 0.01 to 5 parts by weight with respect to 100 parts by weight). .

Moreover, it is preferable to mix | blend a ultraviolet absorber especially as another additive.
This is because the active energy ray having a predetermined wavelength can be selectively absorbed within a predetermined range when the active energy ray is irradiated by blending the ultraviolet absorber.
As a result, without inhibiting the curing of the composition for light diffusion control film, for example, as shown in FIG. 4B, the predetermined internal structure formed inside the obtained light diffusion control film is bent. Because it can.

Moreover, it is preferable that an ultraviolet absorber is at least 1 type selected from the group which consists of a hydroxyphenyl triazine type ultraviolet absorber, a benzotriazole type ultraviolet absorber, a benzophenone type ultraviolet absorber, and a hydroxybenzoate type ultraviolet absorber.
The reason for this is that these UV absorbers can bend more clearly in a given internal structure, so the range of light diffusion characteristics in the resulting light diffusion control film can be expanded more effectively. This is because it can be done.
That is, it is confirmed that these ultraviolet absorbers having a peak at a position closer to the wavelength of 365 nm, which is the main wavelength of the high-pressure mercury lamp, cause bending with a small amount.

Moreover, the compounding quantity of the ultraviolet absorber in the composition for light diffusion control films is a value less than 2 parts by weight (however, 0 part by weight with respect to 100 parts by weight of the total amount of the component (A) and the component (B)). Is preferably excluded).
The reason for this is that when the blending amount of the ultraviolet absorber becomes a value of 2 parts by weight or more, the curing of the composition for light diffusion control film is inhibited, and shrinkage wrinkles are generated on the surface of the film or it is not cured at all. This is because there are cases. On the other hand, when the blending amount of the ultraviolet absorber is excessively small, it may be difficult to cause sufficient bending of the internal structure formed inside the light diffusion control film.
Therefore, the lower limit of the blending amount of the ultraviolet absorber is more preferably 0.01 parts by weight or more with respect to 100 parts by weight of the total amount of the component (A) and the component (B). More preferably, the value is not less than part by weight.
Further, the upper limit of the blending amount of the ultraviolet absorber is more preferably 1.5 parts by weight or less with respect to 100 parts by weight of the total amount of the component (A) and the component (B). More preferably, the following values are used.

2. Step (b): Application Step As shown in FIG. 5 (a), the step (b) is a step of forming the coating layer 1 by applying the light diffusion control film composition to the process sheet 2 in a film form. It is.
As this process sheet | seat, as described in 1st Embodiment, a normal peeling film can be used.

Moreover, as a method of apply | coating the composition for light-diffusion films on a process sheet | seat, the bar coat method, the knife coat method, the roll coat method, the blade coat method, the die coat method, the gravure coat method etc. can be used, for example.
In addition, the thickness of the coating layer at this time is preferably set to a value within the range of 10 to 700 μm.

3. Step (c): Lamination Step The step (c) is a step of laminating the overlaminate film 4 satisfying the relational expression (1) on the exposed surface of the coating layer 1 as shown in FIG. .
That is, it is a step of laminating the coating layer 1 that is not cured and does not crush while maintaining the gap between the process sheet 2 and the overlaminate film 4.

4). Step (d): Active energy ray irradiation step As shown in FIG. 5C, the step (d) is performed on the coating layer 1 via the overlaminate film 4 while moving the coating layer 1. This is a process of irradiating an active energy ray as parallel light 60 to form a predetermined internal structure such as a column structure or a louver structure in the film to obtain a light diffusion control film 10.
Hereinafter, as an example, a case where a column structure is formed will be described.

That is, as shown in FIG. 5C, the parallel light 60 having a high degree of parallelism of light rays is applied to the coating layer 1 formed on the process sheet 2.
Here, the parallel light means substantially parallel light that does not spread even when the traveling direction of the light is viewed from any direction.
More specifically, for example, as shown in FIG. 5C, the irradiation light 70 from the point light source 102 can be converted into parallel light 60 by a lens 104.

Moreover, it is preferable to make the parallelism of irradiation light into the value of 10 degrees or less.
This is because the column structure can be formed efficiently and stably by setting the parallelism of the irradiation light to a value within this range.
Therefore, the parallelism of the irradiation light is more preferably 5 ° or less, and further preferably 2 ° or less.

As shown in FIG. 6, the irradiation angle θx when the normal angle with respect to the surface of the coating layer 1 is 0 ° is usually in the range of −80 to 80 °. It is preferable to use a value.
This is because if the irradiation angle is a value outside the range of −80 to 80 °, the influence of reflection on the surface of the coating layer 1 becomes large, and it may be difficult to sufficiently form the column structure. Because there is.
Note that an arrow MD in FIG. 6 indicates the moving direction of the coating layer.

Moreover, it is preferable to use ultraviolet rays as irradiation light which is an active energy ray.
The reason for this is that, in the case of electron beams, the polymerization rate is very fast, so the (A) component and the (B) component cannot be sufficiently separated in the polymerization process, making it difficult to form a column structure. Because.
On the other hand, when compared with visible light and the like, ultraviolet rays are more abundant in ultraviolet curable resins that can be cured by irradiation and usable photopolymerization initiators. Therefore, components (A) and (B) This is because the range of choices can be expanded.

Moreover, as an irradiation condition when ultraviolet rays are used as the active energy ray, it is preferable that the peak illuminance on the surface of the coating layer is set to a value within the range of 0.1 to 10 mW / cm ² .
This is because when the peak illuminance is less than 0.1 mW / cm ² , it may be difficult to clearly form the column structure. On the other hand, if the peak illuminance exceeds 10 mW / cm ² , the curing rate is estimated to be too high, and the column structure may not be formed effectively.
Therefore, the lower limit of the peak intensity of the coating layer surface, more preferably, to 0.3 mW / cm ² or more values, and even more preferably from 0.5 mW / cm ² or more.
The upper limit of the peak intensity of the coating layer surface, more preferably, to 8 mW / cm ² or less of the value, and even more preferably from 6 mW / cm ² following values.

Moreover, it is preferable to make the integrated light quantity in the coating layer surface in the case of using an ultraviolet ray as an active energy ray into the value within the range of 5-200 mJ / cm < ² >.
This is because when the integrated light quantity is less than 5 mJ / cm ² , it may be difficult to sufficiently extend the column structure from above to below. On the other hand, when the integrated light quantity exceeds 200 mJ / cm ² , the resulting light diffusion control film may be colored.
Therefore, the lower limit of the integrated light quantity in the coating layer surface, more preferably to 7 mJ / cm ² or more values, and even more preferably from 10 mJ / cm ² or more.
The upper limit of the integrated quantity of light in the coating layer surface, more preferably, to 150 mJ / cm ² or less of the value, and even more preferably to a 100 mJ / cm ² following values.

In addition, from the viewpoint of stably forming the column structure while maintaining mass productivity, when irradiating ultraviolet rays or the like as active energy rays, the coating layer formed on the process sheet is 0.1 to 10 m / It is preferable to move at a speed within a range of minutes.
In particular, it is more preferable to move at a speed of 0.2 m / min or more, and more preferable to move at a speed of 3 m / min or less.

In the present invention, if the internal structure formed in the light diffusion control film obtained by curing the composition for light diffusion control film includes a high refractive index region and a low refractive index region, It is not limited to the column structure described above.
For example, when the louver structure 20b shown in FIG. 4A is formed, substantially parallel light is applied to the coating layer 1 formed on the process sheet 2 as irradiation light when viewed from one direction. What is necessary is just to irradiate the light which looks like non-parallel random light when it sees from another direction.
In addition, when the predetermined internal structure 20d shown in FIG. 4C is formed, the coating layer 1 formed on the process sheet 2 is substantially parallel light when viewed from one direction. When viewed from other directions, it is sufficient to irradiate light adjusted to a certain degree of parallelism, not completely random light.

  Hereinafter, the present invention will be described in more detail by way of examples. However, the present invention is not limited to these descriptions.

[Example 1]
1. Preparation of Overlaminate Film A biaxially stretched polyethylene terephthalate film roll (hereinafter sometimes referred to as “film A”) having a thickness of 38 μm and a length of 1000 mm in the short direction (width direction) was prepared as an overlaminate film.

(1) Measurement of phase difference Re The phase difference Re of the prepared overlaminate film was measured.
That is, an arbitrary location in the longitudinal direction of the prepared overlaminate film was specified as a measurement location.
Next, using the phase difference measuring device KOBRA-WR manufactured by Oji Scientific Instruments, the phase difference Re (nm) is calculated using 20 points every 50 mm along the short direction 1000 mm at the specified measurement points. It was measured. The obtained result is shown in the characteristic curve A of FIG.
FIG. 7 is a short direction position-phase difference Re chart in which the horizontal axis represents the position (mm) in the short direction of the overlaminate film and the vertical axis represents the phase difference Re (nm).
Further, from the obtained measurement value, the median value (nm) of the phase difference Re and the variation ((Re _max −Re _min ) / (Re _max + Re _min ) × 100) (%) represented by the formula (1) are obtained. Calculated. The obtained results are shown in Table 1.

(2) Surface roughness Rp and Ra
Moreover, the arithmetic average roughness (Ra) and the maximum peak height (Rp) of the prepared overlaminate film were measured.
That is, using the surface shape measuring device WYKO NT110 (ANSI B46.1 standard) manufactured by Veeco, the arithmetic average roughness (Ra) (nm) of the prepared overlaminate film was measured and the maximum peak height (Rp) was measured. (Nm) was measured. The obtained results are shown in Table 1.

(3) Measurement of haze and total light transmittance Moreover, the haze of the prepared overlaminate film was measured.
That is, using a haze meter NDH-5000 manufactured by Nippon Denshoku Industries Co., Ltd., the haze (%) and total light transmittance (%) of the prepared overlaminate film were measured. The obtained results are shown in Table 1.

2. Synthesis of Low Refractive Index Active Energy Ray Curing Component In a container, 1 mol of polypropylene glycol (PPG) having a weight average molecular weight of 9200 as component (B2) is isophorone diisocyanate (IPDI) 2 as component (B1). After 2 mol of 2-hydroxyethyl methacrylate (HEMA) as component (B3) was accommodated, it was reacted according to a conventional method to obtain polyether urethane methacrylate having a weight average molecular weight of 9900 as component (B).

In addition, the weight average molecular weight of polypropylene glycol and polyether urethane methacrylate is a polystyrene conversion value measured according to the following conditions by gel permeation chromatography (GPC).
GPC measurement device: manufactured by Tosoh Corporation, HLC-8020
-GPC column: manufactured by Tosoh Corporation (hereinafter, described in order of passage)
TSK guard column HXL-H
TSK gel GMHXL (× 2)
TSK gel G2000HXL
・ Measurement solvent: Tetrahydrofuran ・ Measurement temperature: 40 ° C.

3. Preparation of Composition for Light Diffusion Control Film Next, o-phenylphenoxyethoxyethyl acrylate having a molecular weight of 268 represented by the above formula (3) as component (A) (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester A- LEN-10) 62.5 parts by weight and 37.5 parts by weight of polyether urethane methacrylate having a weight average molecular weight of 9900 as component (B), total amount of component (A) and component (B) = 100 weight After adding 1.25 parts by weight of 2-hydroxy-2-methyl-1-phenyl-propan-1-one as component (C) to the part, the mixture was heated and mixed at 80 ° C. And a light diffusion control film composition was obtained.
The refractive indexes of the components (A) and (B) were measured according to JIS K0062 using an Abbe refractometer (Atago Co., Ltd., Abbe refractometer DR-M2, Na light source, wavelength 589 nm). , 1.58 and 1.46, respectively.

4). Application Step Next, the obtained composition for a light diffusion control film was applied to the release treatment surface while pulling out a transparent polyethylene terephthalate film roll as a process sheet subjected to a release treatment with a length of 1000 mm in the short direction, A 60 μm coating layer was formed.

5). Lamination process Next, the prepared overlaminate film was laminated on the exposed surface side of the coating layer by roll-to-roll.
Next, as shown in FIG. 5 (c), an ultraviolet spot parallel light source (manufactured by JATEC Co., Ltd.) whose central ray parallelism is controlled within ± 3 ° is used, and parallel light with a parallelism of 2 ° or less is shown in FIG. The coating layer was irradiated so that the irradiation angle θx shown in FIG.
At that time, the peak illuminance was 2.00 mW / cm ² , the integrated light quantity was 53.13 mJ / cm ² , the lamp height was 1480 mm, and the moving speed of the coating layer was 1.0 m / min.
The above-described peak illuminance and integrated light amount were measured by installing a UV METER (manufactured by Eye Graphics Co., Ltd., eye ultraviolet integrated irradiator UVPF-A1) equipped with a light receiver at the position of the coating layer.
In addition, the film thickness of the light diffusion control film was measured using a constant pressure thickness measuring instrument (manufactured by Takara Seisakusho Co., Ltd., TECKLOCK PG-02J).

Moreover, the cross-sectional photograph which cut | disconnected the light-diffusion control film which has the obtained column structure in the surface parallel to the moving direction of an application layer and orthogonal to a film surface is shown to Fig.8 (a).
The length of the column structure in the film thickness direction was 60 μm, and the inclination angle was 7 °.
The light diffusion control film was cut using a razor, and a cross-sectional photograph was taken by reflection observation using a digital microscope VHX-1000 manufactured by Keyence.

6). Evaluation (1) Measurement of Deflection Haze Deflection haze of the obtained light diffusion control film was measured.
That is, a strip-shaped test piece (120 mm width) along the longitudinal direction was cut out from an arbitrary portion of the obtained process sheet / light diffusion control film / overlaminate film laminate, manufactured by Toyo Seiki Seisakusho Co., Ltd., The variable angle haze (%) was measured using Haze Guard Plus.
At this time, the distance between the integrating sphere opening and the light diffusion control film was 62 mm, and the incident point of the reference light was the center point in the short direction of the light diffusion control film in the test piece.
Moreover, as shown to Fig.9 (a), while measuring the reference light injecting from the process sheet side of a test piece, changing the incident angle of the reference light along the elongate direction of a light-diffusion control film, it measured. . The obtained result is shown in the characteristic curve A in FIG.
FIG. 9B is an incident angle-variable haze chart in which the horizontal axis indicates the incident angle (°) of the reference light and the vertical axis indicates the variable angle haze (%). The width of the incident angle region with a haze of 70% or more was calculated from FIG. 9B and is shown in Table 1.
Therefore, from the characteristic curve A, it is possible to confirm the property that the light diffusion state varies depending on the incident angle, that is, the incident angle dependency (the characteristic curve B: Example 2 and the characteristic curve C: Comparative Example 1 are also the same).

(2) Straight transmitted light intensity P.I. Measurement of T The straight transmission intensity of the obtained light diffusion control film was measured.
In other words, along the 1000 mm short direction of the test piece similar to that used in the measurement of the angle change haze, 20 points for every 50 mm were used as measurement points, and the angle change colorimeter VC-2 manufactured by Suga Test Instruments Co., Ltd. The straight transmitted light intensity P. T (%) was measured.
At this time, as shown in FIG. 10 (a), the measurement was performed with light incident on the process sheet side of the test piece from a direction inclined by 60 ° in the direction opposite to the direction in which the columnar object inclines in the light diffusion control film. did. The obtained result is shown in the characteristic curve A in FIG.
FIG. 10B is a short-direction position-straight transmission light intensity chart in which the horizontal axis indicates the position (mm) in the short direction of the light diffusion control film and the vertical axis indicates the straight transmission light intensity (%). .
Further, from the obtained measured value, the straight transmitted light intensity P.I. The median (%) of T and the variation represented by the formula (1) ((P.T _max -P.T _min ) / (P.T _max + P.T _min ) × 100) (%) were calculated. The obtained results are shown in Table 1.

[Example 2]
In Example 2, as an overlaminate film, a biaxially stretched polyethylene terephthalate film roll (hereinafter referred to as film B) having a thickness of 38 μm and a length of 1000 mm in the short direction, having the phase difference Re and surface roughness shown in Table 1. A laminate was produced and evaluated in the same manner as in Example 1 except that the above was used.
The obtained results are shown in Table 1, characteristic curve B in FIG. 8 (b) and FIG. 9 (b), and characteristic curve B in FIG. 10 (b).

[Comparative Example 1]
In Comparative Example 1, as an overlaminate film, a biaxially stretched polyethylene terephthalate film roll (hereinafter referred to as “film C”) having a thickness of 75 mm and a length of 1000 mm in the short direction, having the phase difference Re and the surface roughness shown in Table 1. A laminated body was produced and evaluated in the same manner as in Example 1 except that it was used.
The obtained results are shown in Table 1, characteristic curve C in FIGS. 8B and 9B, and characteristic curve C in FIG. 10B.

As described above in detail, according to the present invention, by setting the variation in retardation measured along a predetermined direction in the overlaminate film surface to a value within a predetermined range, the internal structure unformed region is Even if it does not occur or occurs, the internal structure can be formed uniformly.
As a result, it has become possible to obtain a light diffusion control film having uniform light diffusion characteristics regardless of the location in the film plane.
Therefore, the light diffusion control film obtained by the present invention is expected to significantly contribute to improving the quality of liquid crystal display devices and projection screens.

1: coating layer, 2: base material, 2 ′: another base material, 10: anisotropic light diffusion adhesive sheet, 10a: isotropic light diffusion control film, 10b to 10d: light diffusion control film, 12, 12b to 12d: Region having a relatively high refractive index (including a plate-like region having a relatively high refractive index), 12a: a columnar object having a relatively high refractive index, and 14, 14a to 14d: regions having a relatively low refractive index. (Including a plate-like region having a relatively low refractive index), 16: bent portion, 20: internal structure, 20a ′: boundary surface, 20a: column structure, 20b: louver structure, 20c: bent column structure, 20d: Predetermined internal structure, 60: parallel light, 70: emitted light from a point light source, 100: laminate, 102: point light source, 104: lens

According to the present invention, a laminate in which an overlaminate film is laminated on at least one surface of a light diffusion control film derived from the composition for light diffusion control film, wherein the light diffusion control film has a low refractive index. A plurality of high-refractive index regions in the region, the high-refractive index region has an internal structure extending in the thickness direction, and is within the stacking plane of the laminate, and the light diffusion control film The moving direction at the time of forming is the long direction, the direction perpendicular to the long direction is the short direction, and the maximum value of the phase difference Re (nm) at the measurement location along the short direction of the overlaminate film is Re _max When the minimum value is Re _min , a laminate that satisfies the following relational expression (1) is provided, and the above-described problems can be solved.
(Re _max −Re _min ) / (Re _max + Re _min ) × 100 <35 (%) (1)
That is, according to the laminate of the present invention, the dispersion of the phase difference Re measured along a predetermined direction in the overlaminate film surface is set to a value within a predetermined range. A laminate of an overlaminate film and a light diffusion control film whose light diffusion characteristics are uniform regardless of the location in the film plane is cured by laminating the overlaminate film on the applied layer. Can do.

Claims (7)

At least one surface of the light diffusion control film derived from the composition for light diffusion control film is a laminate having an overlaminate film in a laminated state,
The light diffusion control film has a plurality of high refractive index regions in a low refractive index region, the high refractive index region has an internal structure extending in the thickness direction,
Within the laminating surface of the laminate, the moving direction when forming the light diffusion control film is the long direction, the direction perpendicular to the long direction is the short direction, and
When the maximum value of the phase difference Re (nm) measured along the short direction of the overlaminate film is Re _max and the minimum value is Re _min , the following relational expression (1) is satisfied. Laminated body.
(Re _max −Re _min ) / (Re _max + Re _min ) × 100 <35 (%) (1)   The laminate according to claim 1, wherein the length of the overlaminate film in the short direction is set to a value within a range of 100 to 10,000 mm.   The laminate according to claim 1 or 2, wherein a median value of the retardation Re of the overlaminate film is set to a value within a range of 1000 to 3000 nm.   4. The laminate according to claim 1, wherein the overlaminate film has a thickness in a range of 5 to 5000 μm.   The internal structure of the light diffusion control film includes a column structure in which a plurality of columnar objects having a relatively high refractive index are provided in a film thickness direction in a region having a relatively low refractive index. The laminated body as described in any one of Claims 1-4 to do.   The louver structure formed by alternately arranging a plurality of plate-like regions having different refractive indexes in any one direction along the film surface is included as an internal structure in the light diffusion control film. The laminate according to any one of the above. It is a manufacturing method of the layered product according to any one of claims 1 to 6,
The manufacturing method of the laminated body characterized by including the following process (a)-(d).
(A) A step of preparing a composition for a light diffusion control film containing a high refractive index active energy ray curable component and a low refractive index active energy ray curable component (b) The composition for a light diffusion control film with respect to a process sheet (C) Step of forming a coating layer and forming a coating layer (c) Laminating an overlaminate film satisfying the relational expression (1) on the exposed surface of the coating layer (d) While moving the coating layer The step of irradiating the coating layer with active energy rays through the overlaminate film