JP6420425B1 - Laminate and method for producing laminate - Google Patents

Abstract

The present invention provides a laminate that is uniform regardless of the location in the film plane, and a method for producing such a laminate.
A plurality of regions having a relatively high refractive index in a region having a relatively low refractive index, such as a laminate in which an overlaminate film is laminated on at least one surface of a light diffusion control film The moving direction when photocuring the coating layer derived from the light diffusion control film composition is the long direction, the direction perpendicular to the long direction is the short direction, and over The relational expression when the maximum value of the orientation angle φ (°) in the slow axis direction with reference to the long direction as the reference is φ _max and the minimum value is φ _min measured along the short direction of the laminate film Satisfy (1).
(Φ _max −φ _min ) / (φ _max + φ _min ) × 100 <16 (%) (1)
[Selection] 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.

  Another type of light diffusion control film is a 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. Diffusion 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 the cited 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 circumstances as described above, and the variation in the orientation angle in the slow axis direction measured along the predetermined direction in the overlaminate film surface is within the predetermined range. By setting the value, the present inventors have found that the internal structure can be formed uniformly even when the internal structure non-formed region does not occur or is generated, and the present invention has been completed.
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, wherein 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, and the moving direction of the coating layer when photocoating the coating layer derived from the composition for light diffusion control film Is the longitudinal direction, the direction perpendicular to the longitudinal direction in the film plane is the short direction, and measured along the short direction of the overlaminate film, the orientation angle in the slow axis direction based on the long direction φ (°) (0 ° < Φ <180 °) the maximum value phi _max of the minimum value when the phi _min, laminate is provided which is characterized by satisfying the following relational expression (1) The above-mentioned problem can be solved.
(Φ _max −φ _min ) / (φ _max + φ _min ) × 100 <12 (%) (1)
That is, according to the laminate of the present invention, the dispersion of the orientation angle φ in the slow axis direction measured along the predetermined direction in the overlaminate film surface is set to a value within the predetermined range, so that the light diffusion control By curing in a state where the overlaminate film is laminated to the coating layer made of the film composition, the light diffusion control film having uniform light diffusion characteristics regardless of the location in the film plane, and the overlaminate film A laminate can be obtained.

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.

Further, in constituting the laminate of the present invention, it is preferable to set the median value of the orientation angle φ in the slow axis direction of the overlaminate film within a range of 45 to 135 °.
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 manufacturing a laminate of the present invention, the slow axis direction measured along a predetermined direction in the overlaminate film plane Since the variation of the orientation angle φ is set to a value within a predetermined range, the overlaminate film is laminated on the coating layer made of the composition for light diffusion control film. By photocuring while over preparative, it is possible to obtain a light diffusing control film light diffusion characteristics are uniform regardless of the position of the film plane, the laminate of the overlaminate film.

FIG. 1A to FIG. 1B are diagrams provided for explaining the outline of the laminate of the present invention. FIG. 2 is a diagram for explaining the orientation angle φ in the overlaminate film. FIGS. 3A to 3B are views for explaining an outline of a light diffusion control film having a column structure in the film. FIGS. 4A to 4B are diagrams for explaining incident angle dependency and isotropic light diffusion in a light diffusion control film having a column structure in the film. 5 (a) to 5 (d) are diagrams provided to explain an aspect of the internal structure of the light diffusion control film in the present invention. 6 (a) to 6 (c) are diagrams provided for explaining the method for producing a laminate according to the present invention. FIG. 7 is a diagram for explaining the irradiation angle of the active energy ray. FIG. 8 is a diagram provided to show the relationship between the position in the short direction of the overlaminate film in Examples 1-2 and Comparative Example 1 and the orientation angle φ. FIGS. 9A to 9C 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. 10A to 10B are diagrams provided to show the relationship between the incident angle of the reference light with respect to the light diffusion control films in Examples 1-2 and Comparative Example 1, and the variable angle haze. 11A to 11B 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]
A first embodiment of the present invention is a laminate 100 in which an overlaminate film 4 is laminated on at least one surface of a light diffusion control film 10 as shown in FIG.
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, as shown in FIG. 1B, the moving direction MD of the coating layer 1 when photocuring the coating layer 1 derived from the composition for light diffusion control film is the longitudinal direction LD, in the film plane. The slow axis based on the long direction MD, which is measured along the short direction SD of the overlaminate film 4 as shown in FIG. Lamination characterized by satisfying the following relational expression (1) when the maximum value of orientation angle φ (°) (0 ° <Φ <180 °) in the direction is φ _max and the minimum value is φ _min Is the body.
(Φ _max −φ _min ) / (φ _max + φ _min ) × 100 <12 (%) (1)

That is, it is a laminate 100 in which the overlaminate film 4 is laminated on at least one surface of a light diffusion control film (an anisotropic light diffusion control film or the like), and the light diffusion control film 10 has a high refractive index active energy. It is a photocured product of a composition for a light diffusion control film containing a linear curing component and a low refractive index active energy ray curing component, and has a relatively high refractive index in a region 14 having a relatively low refractive index. While having the internal structure 20 provided with the several area | region 12, the moving direction MD of the said coating layer 1 at the time of photocuring the coating layer 1 derived from the composition for light-diffusion control films is set to the longitudinal direction LD and a film surface The direction perpendicular to the long direction LD is defined as the short direction SD, and the length measured along the short direction SD of the overlaminate film 4 as shown in FIG. Orientation angle of the slow axis direction relative to the direction MD phi maximum value (°) and phi _max, the minimum value when the phi _min, and satisfies the following relationship (1) laminated Is the body.
Hereinafter, a first embodiment of the present invention will be specifically described with reference to the drawings as appropriate.
However, “the composition for a light diffusion control film” and its “photocuring” 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 long direction, which is measured along the short direction SD of the overlaminate film 4 as shown in FIG. When the maximum value of the orientation angle φ (°) in the slow axis direction with respect to the direction LD is φ _max and the minimum value is φ _min , the following relational expression (1) is satisfied.
(Φ _max −φ _min ) / (φ _max + φ _min ) × 100 <12 (%) (1)

The reason for this is that when the variation of the orientation angle φ represented by the left side of the relational expression (1) becomes a value of 12% or more, the internal structure of the light diffusion control film obtained by photocuring through the overlaminate film. This is because the formation condition changes excessively for each location in the film plane, and it becomes difficult to maintain the uniformity of the light diffusion characteristics in the film plane.
Therefore, the upper limit value of the variation in the orientation angle φ represented by the left side of the relational expression (1) is more preferably 10% or less, and even more preferably 8% or less.
Further, the smaller the variation value of the orientation angle φ 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 orientation angle φ represented by the left side of the relational expression (1) is preferably 1% or more, more preferably 2% or more, and 3% or more. More preferably.
In calculating the variation in the orientation angle φ, it is preferable to measure the orientation angle φ at 5 to 100 locations at equal intervals along the short direction SD of the overlaminate film (about the median orientation angle φ described later) The same).
Further, as apparent 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 light diffusion control film.
The orientation angle φ can be adjusted by stretching the film, but it is particularly preferable to adjust by biaxial stretching.

Here, the relationship between the variation in the orientation angle φ in the overlaminate film and the uniformity in the light diffusion characteristics of the light diffusion control film will be described with speculation.
That is, it is considered that there is a close relationship between the vibration direction of the irradiated active energy rays and the formed refractive index distribution structure.
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 orientation axis Φ of the overlaminate film. Then, it is estimated that the generated deviation 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 under the overlaminate film are greatly influenced by the orientation axis Φ of the overlaminate film.
For this reason, if the orientation angle Φ varies in the short direction SD, it is considered that the light diffusion characteristics also vary.

The median value of the orientation angle φ in the slow axis direction of the overlaminate film is preferably set to a value within the range of 45 to 135 °.
This is because, when the median value of the orientation angle φ is less than 45 °, it may be cut out from the right end of the wide overlaminate film in mass production. Therefore, it is difficult to manage the orientation angle Φ of the film cut from the end compared to the film cut from the center (around 90 ° orientation angle), and as a result, the light diffusion characteristics of the light diffusion film may vary. Because.
On the other hand, when the median value of the orientation angle φ exceeds 135 °, it may be cut out from the left end of the wide overlaminate film in mass production. Therefore, it is difficult to manage the orientation angle Φ of the film cut from the end compared to the film cut from the center (around 90 ° orientation angle), and as a result, the light diffusion characteristics of the light diffusion film may vary. .
Therefore, the lower limit value of the median value of the orientation angle φ is more preferably 55 ° or more, and further preferably 80 ° or more.
Further, the upper limit value of the median value of the orientation angle φ is more preferably set to 125 ° or less, and further preferably set to 100 ° 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 transmittance of the active energy rays is excessively lowered, and it is difficult to efficiently form a predetermined internal structure in the light diffusion control film. This is because there are cases.
On the other hand, when the total light transmittance exceeds 97%, the range of material selection may be 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 make the length (width) in the short direction of an overlaminate film into the value within the range of 100-10000 mm.
The reason for this is that 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 a practical requirement for the light diffusion control film. This is because there is a case where the size to be satisfied is not satisfied.
On the other hand, when 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.
This is because, when the film thickness is less than 5 μm, handling becomes difficult, and wrinkles may occur when the overlaminate film is bonded.
On the other hand, even if the film thickness exceeds 5000 μm, it is difficult to handle and wrinkles may occur when the overlaminate film is conveyed.
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, an isotropic having a column structure 20a in the film using FIGS. The isotropic light diffusion control film 10a having light diffusion characteristics will be described.
First, FIG. 3 (a) shows a plan view of an isotropic light diffusion control film 10a having a column structure 20a in the film, and FIG. 3 (b) shows an isotropic light diffusion shown in FIG. 3 (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.
4A shows an overall view of the isotropic light diffusion control film 10a having the column structure 20a in the film, and FIG. 4B shows the isotropic light diffusion control film 10a of FIG. 4A. The diffusion condition of the light diffused by (the shape of the spread of the diffused light) is shown.
That is, as shown in the plan view of FIG. 3A, the isotropic light diffusion control film 10a has a column structure 20a composed of 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 cross-sectional view of FIG. 3B, 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.

As a result, as shown in FIG. 4A, it is presumed that the incident light whose incident angle θ1 is within the light diffusion incident angle region is diffused by the isotropic light diffusion control film 10a.
That is, as shown in FIG. 3B, the incident angle of incident light on 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, 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 20a. 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 predetermined 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. 4A, for example. .
Further, as shown in FIG. 3B, 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. 4B, when incident light is diffused by a film, the diffused emitted 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. 4A, 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.

Further, as shown in FIG. 4A, 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, in the column structure, the change in the direction of incident light inside the predetermined columnar object is not only a step index type in which the direction changes linearly and zigzag due to 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. 5A, the light diffusion control film 10b is formed by alternately arranging a plurality of plate-like regions 12b and 14b having different refractive indexes along any one direction along the film surface. It may have a louver structure 20b.
Alternatively, as shown in FIG. 5B, the light diffusion control film 10c may be a bent column structure 20c in which the columnar object 12c has a bent portion 16 at an intermediate point along the film thickness direction.
Alternatively, as shown in FIG. 5C, the light diffusion control film 10d includes a plurality of flaky objects 12d having a relatively high refractive index in the region 14d having a relatively low refractive index along the film surface. The predetermined internal structure 20d may be arranged in a plurality of rows along any one direction.
Alternatively, as shown in FIG. 5D, the light diffusion control film 10e may be a combination of the louver structure 20b and the column structure 20a in the vertical direction.
That is, there are a wide variety of internal structures known in the technical field of light diffusion control films, but in the light diffusion control films 10a, 10b to 10e in the present invention, any of these internal structures may be used. Good.

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. 5 (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.
Further, in the case of the predetermined internal structure 20d shown in FIG. 5 (c), 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. 5 (d). 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. 3A to 3B, the column structure 20a is an internal structure for isotropic diffusion of incident light. Specifically, the column structure 20a is refracted into a region having a relatively low refractive index. It is an internal structure made up of several pillars with a relatively high rate.

(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. 3A to 3B, the maximum diameter in the cross section of the columnar object 12a is set to a value within the range of 0.1 to 15 μm. preferable.
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 Further, it is preferable to set the thickness (length in the film thickness direction) of the column structure 20a as shown in FIG. 3B to a value in 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 Further, in the column structure, it is preferable that the columnar objects 12a and the like are forested at a constant inclination angle with respect to the film thickness direction of the light diffusion control film.
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 °.
This is because when the inclination angle exceeds 80 °, the absolute value of the incident angle of the active energy ray may increase accordingly. For this reason, the ratio of reflection of active energy rays at the interface between air and the coating layer increases, and it may be 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%.
This is because when the median value is less than 0.1%, the transmittance as a film may be deteriorated.
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 Further, the laminate of the present invention is a process sheet on one surface of the light diffusion control film, on which the overlaminate film is laminated, and on the side opposite to the side that is in the laminated state. May be laminated.
Thus, by sandwiching both surfaces of the light diffusion control film with the overlaminate film and the process sheet, the light diffusion control film can be effectively protected.
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]
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 1 The composition for light diffusion control film in the present invention includes a high refractive index active energy ray curing component as the (A) component. .
The reason for this is that by including a high refractive index active energy component as the component (A), a predetermined difference is caused in the polymerization rate between the low refractive index active energy ray curing component as the component (B) described later, This is because by suppressing the copolymerization of both components uniformly, the component (A) and the component (B) can be photocured while efficiently separating the phases.
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.

(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.

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 2,300-19,500 normally, Preferably it is 4,300-14,300, Most preferably, it is 6,300-12,300.

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 light diffusion control film composition, for example, as shown in FIG. 5B, the bent portion 16 is formed into a predetermined internal structure formed inside the light diffusion control film 10c obtained. It is because it can produce.

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. 6A, 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 30 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. .
In other words, the step (c) is a step of laminating the coating layer 1 before curing while keeping the gap between the process sheet 2 and the overlaminate film 4 so as not to crush.

4). Step (d): Active energy ray irradiation step As shown in FIG. 6C, the step (d) is active against the coating layer 1 through the overlaminate film 4 while moving the coating layer 1. This is a step of irradiating energy rays (parallel light or the like) 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 the column structure is formed by irradiating the parallel light 60 will be described.

That is, as shown in FIG.6 (c), the parallel light 60 with a high parallelism of a light ray is irradiated with respect to the coating layer 1 formed on the process sheet | seat 2. As shown in FIG.
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. 6C, 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.

Further, as shown in FIG. 7, the irradiation angle θx when the normal angle with respect to the surface of the coating layer 1 is 0 ° is usually within a 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. 7 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 of the active energy ray irradiation, 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 of the active energy ray irradiation, 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 of the active energy ray irradiation, 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 of the active energy ray irradiation, 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 a column structure while maintaining mass productivity, when irradiating ultraviolet rays 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 it is more preferable to move at a speed of 8 m / min or less.

In addition, in this invention, if the internal structure formed in the light-diffusion control film formed by photocuring the composition for light-diffusion control films contains a high refractive index area | region and a low refractive index area | region, The column structure described above is not limited.
For example, in the case of forming the louver structure 20b shown in FIG. 5A, 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.
Further, in the case of forming the predetermined internal structure 20d shown in FIG. 5 (c), it is substantially parallel light when viewed from one direction with respect to the coating layer formed on the substrate. When viewed from the above direction, 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 orientation angle φ The orientation angle φ 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, along the 1000 mm short direction in the specified measurement location, 20 points are measured every 50 mm as measurement points, using a phase difference measuring device KOBRA-WR manufactured by Oji Scientific Instruments Co., Ltd., and using the long direction as a reference. The orientation angle φ (°) in the slow axis direction was measured. The obtained result is shown in the characteristic curve A of FIG.
FIG. 8 is a short direction position-orientation angle φ chart in which the horizontal axis represents the position (mm) in the short direction of the overlaminate film and the vertical axis represents the orientation angle (°).
Further, the median value (°) and variation ((φ _max −φ _min ) / (φ _max + φ _min ) × 100) (%) of the orientation angle (φ) were calculated from the obtained measurement values. The obtained results are shown in Table 1.

(2) Measurement of surface roughness Rp and Ra Moreover, arithmetic average roughness Ra and 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 is measured according to ANSI B46.1. At the same time, the maximum peak height (Rp) (nm) was measured in accordance with ANSI B46.1. 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 the 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-curable component In a container, 1 mol of polypropylene glycol (PPG) having a weight average molecular weight of 9,200 as component (B2), isophorone diisocyanate (IPDI) as component (B1) 2) and 2 mol of 2-hydroxyethyl methacrylate (HEMA) as component (B3) were accommodated and reacted according to a conventional method to obtain polyether urethane methacrylate having a weight average molecular weight of 9,900 as component (B). Got.

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 a polyether urethane methacrylate having a weight average molecular weight of 9,900 as the component (B) synthesized, the total amount of the components (A) and (B) = After adding 1.25 parts by weight of 2-hydroxy-2-methyl-1-phenyl-propan-1-one as component (C) to 100 parts by weight, the mixture was heated at 80 ° C. Mixing was performed to obtain a composition for a light diffusion control film.
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. 6 (c), using an ultraviolet parallel light source (manufactured by Eye Graphics Co., Ltd.), parallel light with a parallelism of 2 ° or less is used, and the irradiation angle θx shown in FIG. In this way, the coating layer was irradiated.
The peak illuminance at that time was 1.08 mW / cm ² , the integrated light quantity was 32.47 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 illuminance meter 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 a coating layer and orthogonal to a film surface is shown to Fig.9 (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.10 (a), while measuring the reference light injecting from the process sheet | seat 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. 10B 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.
Therefore, from the characteristic curve A, it is possible to confirm the property that the light diffusion condition 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 linearly transmitted light 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. 11 (a), measurement was performed by entering light from a direction inclined 60 ° in the direction opposite to the direction in which the columnar object in the light diffusion control film inclines with respect to the process sheet side of the test piece. did. The obtained result is shown in the characteristic curve A of FIG.
FIG. 11B is a short-direction-position-straight-transmitted light intensity chart in which the horizontal axis indicates the position (mm) in the short-length direction of the light diffusion control film and the vertical axis indicates the straight-line transmitted light intensity (%). .
Further, from the obtained measured value, the straight transmitted light intensity P.I. The median (%) and variation ((P.T _max -P.T _min ) / (P.T _max + P.T _min ) × 100) (%) of T were calculated. The obtained results are shown in Table 1.

[Example 2]
Example 2 is the same as Example 1 except that a biaxially stretched polyethylene terephthalate film roll (hereinafter sometimes referred to as film B) having a thickness of 38 μm and a length of 1000 mm in the short direction was used as the overlaminate film. Similarly, a laminate was produced and evaluated. The obtained results are shown in Table 1, characteristic curve B in FIG. 8, cross-sectional photograph in FIG. 9B, characteristic curve B in FIG. 10B, and characteristic curve B in FIG.

[Comparative Example 1]
In Comparative Example 1, an example was used except that a biaxially stretched polyethylene terephthalate film roll (hereinafter sometimes referred to as “film C”) having a thickness of 75 μm and a length of 1000 mm in the short direction was used as the overlaminate film. A laminate was produced and evaluated in the same manner as in Example 1. The obtained results are shown in Table 1, characteristic curve C in FIG. 8, cross-sectional photograph in FIG. 9C, characteristic curve C in FIG. 10B, and characteristic curve C in FIG.

As described above in detail, according to the present invention, by setting the variation in the orientation angle in the slow axis direction measured along a predetermined direction in the overlaminate film surface to a value within a predetermined range, Even if the unstructured region does not occur or does not occur, 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 contribute significantly 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

Claims (7)

A laminate in which an overlaminate film is laminated on at least one surface of the light diffusion control film, wherein 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,
When the coating layer derived from the composition for light diffusion control film is photocured, the moving direction of the coating layer is the long direction, the direction perpendicular to the long direction in the film plane is the short direction,
When the maximum value of the orientation angle φ (°) in the slow axis direction based on the long direction measured along the short direction of the overlaminate film is φmax, and the minimum value is φmin, The laminated body characterized by satisfying the following relational expression (1).
(Φmax−φmin) / (φmax + φmin) × 100 <12 (%) (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 orientation angle φ in the slow axis direction of the overlaminate film is set to a value within a range of 45 to 135 °. 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