KR20190013436A - Laminate and method for producing laminate - Google Patents

Abstract

The purpose of the present invention is to provide a laminate in which every place on surface of a film is uniform, and a manufacturing method thereof. For the purpose, an over-laminate film is stacked on at least one surface of a light diffusion control film such that the laminate has an inner structure in which a plurality of regions having relatively high refractive index are disposed among regions having relatively low refractive index. A transfer direction in light-curing a coating layer derived from a composition for light diffusion control film is designated as a longitudinal direction, and the direction perpendicular to the longitudinal direction is designated as a shorter direction. Equation (1), (φ_max-φ_min)/(φ_max+φ_min)×100 < 16(%), is satisfied when the maximum of the orientation angle φ(°) toward a slow axis based on the longitudinal direction, which is measured along the shorter direction of the over-laminate film, is designated as φ_max and the minimum thereof is designated as φ_min.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a laminate,

The present invention relates to a laminate and a method for producing the laminate.

Particularly, as a laminate of a light diffusion control film and an overlaminate film obtained by photo-curing a laminate of a coating layer comprising a composition for a light diffusion control film with an overlaminate film, Regardless of the position in the film plane, and a method for producing such a laminated body.

BACKGROUND ART [0002] Conventionally, for example, in the field of optical technology to which a liquid crystal display device, a projection screen, and the like belong, use of a light diffusion control film has been proposed.

Such a light diffusion control film exhibits a constant light diffusion state in a specific incident angle range (hereinafter, it may be referred to as a &quot; light diffusion angle of incidence angle region &quot;). In the incident angle range deviating from the light diffusion angle of incidence angle region, Or exhibits a light diffusion state different from the light diffusion state in the light diffusion angle of incidence region.

Various types of such a light diffusion control film are known, but in particular, a film structure having a columnar structure in which a plurality of columnar materials having a relatively high refractive index in a region where the refractive index is relatively high, Is widely used as a light diffusion control film.

As another type of optical diffusion control film, a light diffusion film having a louver structure in which a plurality of plate-shaped regions having different refractive indexes are alternately arranged along any one direction along the film plane is widely used.

By the way, the light diffusion control film having such a column structure or louver structure can be applied to a coating layer formed by applying a composition for a light diffusion control film containing two or more kinds of polymerizable compounds having different refractive indexes in the form of a film, Is irradiated with an active energy ray.

That is, a light diffusion control film having a predetermined internal structure can be obtained by irradiating a predetermined active energy ray whose direction is controlled with respect to the coating layer, and curing the two kinds or more of the polymerizable compounds in the coating layer while phase- have.

However, when a predetermined active energy ray is directly irradiated to the coating layer, it has been found that it becomes difficult to form a predetermined internal structure to the end in the film thickness direction, that is, the film top surface.

That is, although a predetermined internal structure can be formed in the lower portion in the film thickness direction, a problem arises that an internal structure unformed region is generated in the upper portion.

Thus, a technique for forming a predetermined internal structure up to the upper surface of a film without generating an internal structure non-formation region is disclosed (see, for example, Patent Document 1).

That is, Patent Document 1 discloses a method for manufacturing a semiconductor device, which comprises a light irradiation mask bonding step of 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 a curing step of curing the uncured resin composition layer by irradiating light through the light curing resin composition layer to form an anisotropic diffusion layer, wherein a diffusing property is changed by an incident angle of light .

Moreover, short of the surface roughness of the light irradiation to the mask 0.05~0.50㎛, the oxygen permeability coefficient of the illumination mask 1.0 × 10 ^- it has been described that below ^{11 ㎤ (STP) ㎝ / (} ㎠ · s · Pa) .

That is, there is disclosed a technique for suppressing the occurrence of an internal structure non-formation region by photocuring a predetermined overlaminate film laminated on a coating layer composed of the composition for a light diffusion control film.

Japanese Patent Laid-Open Publication No. 2016-194687 (Claims)

However, even when the light irradiation mask described in Reference 1 is used, it is difficult to stably suppress the occurrence of the internal structure non-formation region.

Particularly, in one continuous light diffusion control film having a width, there were portions where no internal structure unformed areas were generated, and portions where they were generated were also seen. From this, it was found that the light diffusing property was also changed by the incidence of light in the film surface, and the problem was that the light diffusing property as a whole became uneven.

In view of the above, the inventors of the present invention have made an effort to give an uneven distribution of the orientation angle in the direction of the slow axis measured along the predetermined direction in the overlaminate film plane within a predetermined range The present inventors have found that the internal structure can be uniformly formed even when the internal structure non-formation area does not occur or even when the internal structure non-formation area does not occur, thereby completing the present invention.

That is, an object of the present invention is to provide a laminate of a light diffusion control film and an overlaminate film, obtained by photo-curing a laminate of a coating layer comprising a composition for a light diffusion control film with an overlaminate film, The present invention is to provide a laminate in which the light diffusion property of the film is uniform regardless of the position in the film plane, and a method for producing such a laminate.

According to the present invention, there is provided 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, (0 DEG) &amp;le; (DEG) in the slow axis direction with respect to the longitudinal direction, which is measured along the short side direction of the overlaminate film, and has an internal structure formed by extending in the thickness direction, The following relation (1) is satisfied when the maximum value of? &_Lt; 180 DEG is? _Max and the minimum value thereof is? _Min . Thus, the above-described 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, since the non-uniformity of the orientation angle in the slow axis direction measured along the predetermined direction in the overlaminate film plane is set to a value within a predetermined range, A laminate of a uniform light diffusion control film and an overlaminate film can be obtained irrespective of the location in the film plane of the light diffusing property.

In constructing the laminate of the present invention, it is preferable that the length of the overlaminate film in the short direction is within a range of 100 to 10000 mm.

By such a constitution, it is possible to obtain a laminate having a sufficient length in a short direction, and further to obtain a light diffusion control film having sufficient length in a short direction.

Further, in constructing the laminate of the present invention, it is preferable that the median value of the orientation angle in the slow axis direction of the overlaminate film is within a range of 45 to 135 占.

By such a constitution, generation of the internal structure non-formation region can be effectively suppressed in the light diffusion control film.

In forming the laminate of the present invention, it is preferable to set the film thickness of the overlaminate film to a value within a range of 5 to 5000 mu m.

By such a constitution, an overlaminate film satisfying the relationship (1) can be obtained more stably.

In the laminate of the present invention, the internal structure of the light diffusion control film may be a column having a relatively high refractive index in a region where the refractive index is relatively low, Structure.

By such a constitution, a light diffusion control film having isotropic light diffusion characteristics can be obtained.

Further, in constructing the laminate of the present invention, the internal structure of the light diffusion control film may include a louver structure in which a plurality of plate-shaped regions having different refractive indexes are alternately arranged in an arbitrary one direction along the film plane .

By such a constitution, a light diffusion control film having anisotropic light diffusion characteristics can be obtained.

Further, another aspect of the present invention is a method for producing a laminate, which comprises the following steps (a) to (d).

(a) preparing a composition for a light diffusion control film comprising a high refractive index active energy ray curing component and a low refractive index active energy ray curing component

(b) a step of applying a composition for a light diffusion control film to a process sheet in the form of a film to form a coating layer

(c) a step of laminating an overlaminate film satisfying the relational expression (1) on the exposed surface of the applied layer

(d) a step of irradiating an active energy ray to the coated layer via an overlaminate film while moving the coated layer

That is, according to the method for producing a laminate of the present invention, since the unevenness of the alignment angle? In the slow axis direction measured along the predetermined direction in the plane of the overlaminate film is set to a value within a predetermined range, A laminate of a light diffusion control film and an overlaminate film having a uniform light diffusing property irrespective of the position in the film plane can be obtained by laminating an overlaminate film on the formed coating layer and curing the film.

1 (a) and 1 (b) are diagrams for explaining the outline of a laminate of the present invention.
Fig. 2 is a view for explaining an orientation angle? In an overlaminate film. Fig.
Figs. 3 (a) to 3 (b) are diagrams for explaining the outline of a light diffusion control film having a columnar structure in a film. Fig.
4 (a) and 4 (b) are diagrams for explaining an incident angle dependency and an isotropic light diffusion in a light diffusion control film having a columnar structure in a film.
5 (a) to 5 (d) are diagrams for explaining aspects of the internal structure of the light diffusion control film in the present invention.
6 (a) to 6 (c) are diagrams for explaining a method of manufacturing a laminate according to the present invention.
Fig. 7 is a view for explaining an irradiation angle of active energy rays; Fig.
8 is a view for showing the relationship between the position of the overlaminate film in the short direction and the orientation angle? In Examples 1 and 2 and Comparative Example 1. Fig.
9 (a) to 9 (c) are diagrams for illustrating cross-sectional photographs of the optical diffusion control films in Examples 1 and 2 and Comparative Example 1;
10 (a) and 10 (b) are diagrams for illustrating the relationship between incident angles of reference light to the light diffusion control films in Examples 1 and 2 and Comparative Example 1, and the pitch angle haze;
11A and 11B are diagrams showing the relationship between the positions of the light diffusion control films in the short direction and the linearly transmitted light intensity PT in Examples 1 and 2 and Comparative Example 1 .

[First Embodiment]

A first embodiment of the present invention is a laminated body 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. to be.

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 extending in the thickness direction As shown in Fig. 1 (b), the moving direction MD of the coated layer 1 when the coating layer 1 derived from the composition for a light diffusion control film is photo-cured is referred to as the longitudinal direction LD, As shown in Fig. 2, a direction perpendicular to the longitudinal direction MD is defined as a direction perpendicular to the long axis direction MD, which is measured along the short side direction SD of the overlaminate film 4, (1) is satisfied when the maximum value of the orientation angle? (?) (0 DEG &lt;?&Lt; 180 DEG) is defined as? _Max and the minimum value is defined as? _Min . .

_{(φ max -φ min) / (} φ max + φ min) × 100 <12 (%) (1)

That is, as the laminate 100 in which the overlaminate film 4 is laminated on at least one surface of the light diffusion control film (anisotropic light diffusion control film or the like) 10, the light diffusion control film 10, A high refractive index active energy ray curing component and a low refractive index active energy ray curing component, and is a photo-cured product of a composition for a light diffusion control film comprising a plurality of regions (refractive index- 12 and the movement direction MD of the applied layer 1 when the coating layer 1 derived from the composition for a light diffusion control film is photo-cured is referred to as a long direction LD, As shown in Fig. 2, a direction perpendicular to the longitudinal direction MD is defined as a direction perpendicular to the long axis direction MD, which is measured along the short side direction SD of the overlaminate film 4, (°) of the orientation angle φ To a value of φ _max, and a minimum value when a to φ _min, the laminate satisfy the following relation (1).

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a first embodiment of the present invention will be described in detail with reference to the accompanying drawings.

However, the "composition for a light diffusion control film" and its "photo-curing" will be described in the second embodiment.

1. Overlaminate Film

As shown in Fig. 1 (b), the overlaminate film in the present invention is a laminated film in which the coating layer 1 derived from the composition for a light diffusion control film is moved in the moving direction MD As shown in Fig. 2, a direction perpendicular to the longitudinal direction LD is defined as a direction SD in the longitudinal direction of the overlaminate film 4, which is measured along the longitudinal direction SD of the overlaminate film 4, (1) when the maximum value of the orientation angle? (?) In the slow axis direction on the basis of the maximum value is? _Max and the minimum value is? _Min .

_{(φ max -φ min) / (} φ max + φ min) × 100 <12 (%) (1)

The reason for this is that if the value of the unevenness of the orientation angle phi represented by the left side of the relational expression (1) is 12% or more, the degree of formation of the internal structure in the light diffusion control film obtained by the photo- Is excessively changed for each position 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 of the unevenness of the orientation angle? Represented by the left side of the relational expression (1) is more preferably 10% or less, and more preferably 8% or less.

The smaller the value of the unevenness of the orientation angle? Represented by the left side of the relational expression (1), the better, but if the value becomes excessively small, the range of material selection becomes excessively limited.

Therefore, the lower limit value of the unevenness of the orientation angle? Represented by the left side of the relational expression (1) is preferably 1% or more, more preferably 2% or more, and more preferably 3% or more.

In order to calculate the unevenness of the orientation angle?, It is preferable to measure the orientation angle? At 5 to 100 positions at regular intervals along the short side direction SD of the overlaminate film (the same is true for the median value of the orientation angle? ).

Further, as is apparent from Fig. 1 (b), the longitudinal direction LD and the short direction SD of the overlaminate film coincide with the longitudinal direction LD and the short direction SD of the light diffusion control film.

The orientation angle? Can be adjusted by stretching the film, but is preferably adjusted by biaxial stretching.

Here, the relationship between the unevenness of the orientation angle? In the overlaminate film and the uniformity in the light diffusion property of the light diffusion control film will be explained together with conjecture.

That is, it is considered that there is a close relationship between the vibration direction of the active energy ray to be irradiated and the refractive index distribution structure to be formed.

When the active energy ray is irradiated onto the overlaminate film, the vibration in the longitudinal direction LD and the vibration in the short direction SD of the overlaminate film are affected differently by the orientation axis? Of the overlaminate film. It is assumed that the generated deviation causes the vibration direction of the active energy ray to change. As a result, it is presumed that the light diffusion property of the light diffusion control film formed under the overlaminate film largely depends on the orientation axis phi of the overlaminate film.

Therefore, if the orientation angle? Is non-uniform in the short direction SD, it is considered that the light diffusion characteristics become uneven.

Further, it is preferable that the median value of the orientation angle in the slow axis direction of the overlaminate film is within a range of 45 to 135 占.

This is because when the median value of the orientation angle is less than 45 degrees, the film may be cut off from the right end of the wide overlaminate film in mass production. Therefore, it is difficult to control the orientation angle? Of the film cut out from the end portion of the film cut from the central portion (near 90 占 of the orientation angle), and as a result, the light diffusion property of the light diffusion film may become uneven.

On the other hand, when the median value of the orientation angle? Exceeds 135 deg., It may be cut off from the left end of the wide overlaminate film in mass production. Therefore, it is difficult to control the orientation angle? Of the film cut out from the end portion of the film cut from the central portion (near 90 占 of the orientation angle), and as a result, the light diffusion property of the light diffusion film may become uneven.

Therefore, the lower limit value of the median value of the orientation angle? Is more preferably 55 degrees or more, and more preferably 80 degrees or more.

Further, the upper limit value of the median value of the orientation angle? Is more preferably 125 占 or less, and more preferably 100 占 or less.

Further, it is preferable that the arithmetic average roughness (Ra) of the overlaminate film on the surface to be irradiated with active energy rays is within the range of 1 to 200 nm.

When the Ra is less than 1 nm, the films may adhere to each other at the time of overlaminating film winding, resulting in a large vibration at the time of peeling. Therefore, there is a possibility that the vibration propagates to the portion irradiated with the active energy ray, and the degree (accuracy) of formation of the internal structure of the light diffusion control film is lowered.

On the other hand, when the Ra exceeds 200 nm, the surface shape is too large, so diffusion of the active energy ray occurs, which may interfere with the formation of the structure.

Therefore, the lower limit value of the arithmetic average roughness (Ra) of the overlaminate film is more preferably 5 nm or more, and more preferably 10 nm or more.

The upper limit of the arithmetic mean roughness (Ra) of the overlaminate film is more preferably 100 nm or less, more preferably 40 nm or less, particularly preferably 30 nm or less.

The arithmetic mean roughness (Ra) as one of the surface roughness can be measured in accordance with JIS B 0601: 2001 in conformity with that, but can also be measured in accordance with ANSI B46.1.

Further, the maximum peak height (Rp) of the overlaminate film is preferably set to a value within a range of 20 to 5000 nm.

The reason for this is that when the Rp is less than 20 nm, the films may adhere to each other at the time of unwinding the overlaminate film, resulting in a large vibration at the time of peeling. For this reason, there is a possibility that the vibration propagates to the active energy ray irradiated portion and the degree of formation of the internal structure of the light diffusion control film is lowered. On the other hand, when Rp exceeds 5000 nm, the surface shape is too large, so that active energy rays are diffused, which may hinder the formation of the structure.

Therefore, the lower limit value of the maximum peak height Rp of the overlaminate film is more preferably 50 nm or more, more 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, more preferably 1000 nm or less, and particularly preferably 600 nm or less.

In addition, the maximum peak height Rp as one of the surface roughness can be measured in accordance with JIS B 0601: 2001 to conform to it, but it can also be measured in accordance with ANSI B46.1.

It is also preferable to set the haze of the overlaminate film to a value within a range of 1 to 25%.

The reason for this is that when the haze is less than 1%, the films are closely adhered to each other at the time of pulling the overlaminate film, and the vibration at the time of peeling becomes large. For this reason, there is a possibility that the vibration propagates to the active energy ray irradiated portion and the degree of formation of the internal structure of the light diffusion control film is lowered.

On the other hand, when the haze exceeds 25%, the surface shape is too large, so diffusion of the active energy ray occurs, which may hinder the formation of the structure.

Therefore, the lower limit value of the haze of the overlaminate film is more preferably 3% or more, and more preferably 5% or more.

Further, the upper limit value of the haze of the overlaminate film is more preferably 20% or less, and more preferably 15% or less.

It is also preferable to set the total light transmittance of the overlaminate film to a value within a range of 70 to 97%.

This is because when the total light transmittance is less than 70%, the transmittance of the active energy ray is excessively lowered, which makes it difficult to efficiently form a predetermined internal structure in the light diffusion control film .

On the other hand, if the total light transmittance exceeds 97%, the range of material selection may be excessively limited.

Therefore, the lower limit value of the total light transmittance of the overlaminate film is more preferably 75% or more, and more preferably 80% or more.

The upper limit of the total light transmittance of the overlaminate film is more preferably 95% or less, and more preferably 93% or less.

Examples of the material of the overlaminate film include, but not limited to, polyethylene terephthalate film, triacetylcellulose film, cycloolefin polymer film, cyclic olefin film, ionomer film, polyethylene film, polyvinyl chloride film, A polyvinyl alcohol film, a polyvinyl alcohol film, a polypropylene film, a polyester film, a polycarbonate film, a polystyrene film, a polyacrylonitrile film, an ethylene-vinyl acetate copolymer film, an ethylene-vinyl alcohol copolymer film, Film, nylon film, and cellophane. One of these may be used alone, or two or more of them may be used in combination.

This is because, if these materials are used, an overlaminate film satisfying the relational expression (1) can be obtained more stably.

Further, it is preferable that the length (width) of the overlaminate film in the short direction is within a range of 100 to 10000 mm.

This is because when the length in the short direction is less than 100 mm, the length of the light diffusion control film constituting the laminate in the short direction becomes less than 100 mm, The size required for practical use may not be satisfied.

On the other hand, when the length in the short direction exceeds 10000 mm, it is difficult to uniformly irradiate active energy rays in the width direction.

Therefore, the lower limit value of the length of the overlaminate film in the short direction is more preferably 200 mm or more, more 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, more preferably 6000 mm or less, and particularly preferably 3000 mm or less .

It is also preferable to set the film thickness of the overlaminate film to a value within a range of 5 to 5000 mu m.

The reason for this is that if the film thickness is less than 5 占 퐉, handling becomes difficult and wrinkles may occur at the time of overlaminate film bonding.

On the other hand, even if the film thickness exceeds 5000 m, handling becomes difficult, and wrinkles may be generated at the time of carrying the overlaminate film.

Therefore, the lower limit value of the film thickness of the overlaminate film is more preferably 10 mu m or more, and more preferably 30 mu m or more.

The upper limit value of the film thickness of the overlaminate film is more preferably 1000 占 퐉 or less, more preferably 400 占 퐉 or less, and further preferably 100 占 퐉 or less.

In addition, a release layer may be provided by applying a release agent such as silicone resin to the surface of the overlaminate film which is in contact with the light diffusion control film on both surfaces.

2. Light diffusion control film

(1) Basic principle of light diffusion in a light diffusion control film

First, as an example of a light diffusion control film in the present invention, explanation will be given of an isotropic light diffusion control film 10a having a columnar structure 20a in a film and having an isotropic light diffusion property using Figs. do.

3 (a) shows a plan view of an isotropic light diffusion control film 10a having a columnar structure 20a in the film. Fig. 3 (b) Sectional view of an optical isotropic light diffusion control film 10a when the optical diffusion control film 10a is cut in the vertical direction along the dashed line AA and the cut surface is viewed from the arrow direction.

4A is an overall view of an isotropic light diffusion control film 10a having a columnar structure 20a in the film and FIG. (Diffusion shape of diffusion light) of the light diffused by the diffusion control film 10a.

3 (a), the isotropic light diffusion control film 10a has a columnar structure 12a composed of a columnar body 12a having a relatively high refractive index and a region 14a having a relatively low refractive index, (20a).

3 (b), in the inside of the isotropic light diffusion control film 10a, the columnar body 12a having a relatively high refractive index and the region 14a having a relatively low refractive index are provided And the columnar bodies 12a having a relatively high refractive index are arranged in a fused state so as to have a predetermined gap therebetween.

As a result, as shown in Fig. 4A, it is estimated that the incident light having the incident angle &amp;thetas; 1 within the light diffusion incidence angle range is diffused by the isotropic light diffusion control film 10a.

3 (b), the angle of incidence of the incident light on the isotropic light diffusion control film 10a is set so as to be parallel to the boundary surface 20a 'of the columnar structure 20a within a predetermined angular range The incident light 52 and 54 are incident on the columnar structure 20a in such a manner that the inside of the columnar material 12a having a relatively high refractive index in the columnar structure 20a is changed in the film thickness direction It is presumed that the traveling direction of the light on the light-exiting-surface side becomes unequal.

As a result, when the incident angle is within the range of the light diffusion angle of incidence, it is estimated that the incident light is diffused by the isotropic light diffusion control film 10a to be the predetermined diffused light 52 ', 54'.

On the other hand, when the incident angle of the incident light to the isotropic light diffusion control film 10a deviates from the angle of the light diffusion angle of incidence, the incident light 56 is reflected by the isotropic light diffusion control film 10a, it is assumed that the light passes through and becomes transmitted light 56 '.

According to the above basic principle, the isotropic light diffusion control film 10a provided with the columnar structure 20a exhibits an incident angle dependency in the transmission and diffusion of light, for example, as shown in Fig. 4 (a) .

As shown in Fig. 3 (b), the isotropic light diffusion control film 10a having the columnar structure 20a usually has &quot; isotropic &quot; property as its light diffusion property.

Here, in the present invention, &quot; isotropic &quot; means, as shown in Fig. 4 (b), when incident light is diffused by a film, in a plane parallel to the film in the diffused outgoing light In plan view), the degree of diffusion of the light does not change by the direction in the same plane.

More specifically, as shown in Fig. 4 (a), when the incident light is diffused by the isotropic light diffusion control film 10a, the degree of diffusion of the diffused outgoing light is changed into a circular shape in a plane parallel to the film do.

As shown in Fig. 4A, in the case where the incident angle? 1 of the incident light is included in the light diffusion angle of incidence angle, the isotropic light diffusion control film is formed on the light-exiting surface side It is possible to perform almost the same light diffusion.

Therefore, the isotropic light diffusion control film can be said to have a light converging action of concentrating light at a predetermined position.

The change in the direction of the incident light inside the predetermined columnar structure in the column structure is not limited to the step index type in which the direction changes in a zigzag pattern in a straight line by total reflection as shown in Fig. 3 (b) It may be considered to be a gradient index type which changes in the direction of a curve.

The internal structure of the light diffusion control film of the present invention is not limited to the above-mentioned column structure as long as it includes a high refractive index region and a low refractive index region.

That is, in the technical field of the optical diffusion control film, the optical diffusion control film of the present invention can be similarly formed as long as it is an internal structure that can be formed by conventionally known phase separation.

For example, as shown in Fig. 5A, the light diffusion control film 10b is formed by alternately arranging a plurality of plate-shaped regions 12b, 14b having different refractive indexes along any one direction along the film plane The louver structure 20b may be provided.

Alternatively, as shown in Fig. 5B, the light diffusion control film 10c can be formed in such a manner that the columnar material 12c has a curved columnar structure 20c having the curved portion 16 at the midpoint along the film thickness direction ).

Alternatively, as shown in Fig. 5 (c), the light diffusion control film 10d has a plurality of flakes 12d having a relatively high refractive index in the region 14d having a relatively low refractive index, Or may be a predetermined internal structure 20d formed by arranging a plurality of rows along an arbitrary one direction.

Alternatively, as shown in Fig. 5 (d), 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, the types of internal structures known in the art of the optical diffusion control film are various, but in the optical diffusion control films 10a and 10b to 10e of the present invention, any of the internal structures may be used.

Also, in any internal structure, the basic principle of light diffusion is the same as in the case of the column structure 20a.

However, due to the shape of each internal structure, there is a difference in the shape of spread of diffused light.

For example, in the case of the louver structure 20b shown in Fig. 5 (a), rod-shaped diffused light is generated in the planar surface subjected to anisotropic light diffusion, and a curved column structure 20c shown in Fig. A part of the light that is isotropically light-diffused from above the bent portion further generates diffused light that is isotropically optically diffused from the lower side of the bent portion.

In the case of the predetermined internal structure 20d shown in Fig. 5 (c), since the louver structure 20b and the column structure 20a are hybrid type, an elliptically diffused light is generated at the time of planarization, In the case of the combination of the louver structure 20b and the columnar structure 20a shown in FIG. 5 (d), since a part of the light diffused in the columnar structure 20a is further diffused in the louver structure 20b, So that diffuse light in the form of a bullet is generated.

(2) Internal structure

The internal structure of the optical diffusion control film in 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 a light diffusion property. can do.

Hereinafter, the column structure will be described as an example, but other internal structures such as a louver structure can also conform to the column structure.

3 (a) and 3 (b), the columnar structure 20a is an internal structure for isotropically diffusing incident light. Specifically, the columnar structure 20a has a plurality of It is an internal structure made by immersing columnar material.

(2) -1 Refractive index

It is preferable that the difference between the refractive index in the region where the refractive index in the column structure is relatively low and the refractive index of the plurality of columnar materials with a relatively high refractive index is 0.01 or more.

The reason for this is that when the difference in the refractive index is 0.01 or more, the angle of incidence of the incident light in the column structure becomes narrower, so that the dependence of the incident angle is excessively lowered.

Therefore, the lower limit value of the difference in refractive index is more preferably 0.03 or more, and more preferably 0.1 or more.

The larger the difference in the refractive index is, the more preferable, but from the viewpoint of selecting the material capable of forming the columnar structure, it can be considered that the upper limit is about 0.3.

(2) -2 maximum diameter

In the columnar structure 20a shown in Figs. 3 (a) and 3 (b), it is preferable to set the maximum diameter in the cross section of the columnar body 12a within the range of 0.1 to 15 占 퐉.

This is because, when the maximum diameter is less than 0.1 mu m, it may become difficult to exhibit the light diffusion characteristic irrespective of the incident angle of the incident light. On the other hand, when the maximum diameter exceeds 15 탆, the light going straight in the column structure increases, and the uniformity of the diffused light may be lowered.

Therefore, in the column structure, the lower limit value of the maximum value is more preferably 0.5 mu m or more, and more preferably 1 mu m or more.

In the column structure, the upper limit value of the maximum value is more preferably 10 m or less, and more preferably 5 m or less.

In addition, the cross-sectional shape of the columnar material is not particularly limited, but is preferably circular, elliptical, polygonal, irregular, or the like.

The cross section of the columnar material means a cross section cut by a plane parallel to the film surface.

The maximum diameter, length, and the like of the columnar material can be measured by observing with an optical digital microscope.

The numerical range of the maximum diameter mentioned above is also applied to the distance between the columnar bodies.

(2) -3 Thickness

It is preferable that the thickness (length in the film thickness direction) of the columnar structure 20a as shown in Fig. 3 (b) is set to a value within a range of 10 to 700 mu m.

This is because when the thickness is less than 10 탆, the incident light which goes straight in the column structure increases, and it becomes difficult to obtain a sufficient range of light diffusion characteristics. On the other hand, when the thickness exceeds 700 mu m, when the column structure is formed by irradiating the active energy ray with respect to the composition for a light diffusion control film, the progress of the light polymerization is diffused by the column structure formed at the beginning , It may be difficult to form a desired column structure.

Therefore, the lower limit value of the thickness of the column structure is more preferably 30 mu m or more, and more preferably 50 mu m or more.

Further, the upper limit value of the thickness of the column structure is more preferably 200 m or less, and more preferably 100 m or less.

The term &quot; range of light diffusion characteristics &quot; means a range of the incident angle indicating the light diffusion characteristic and a range of diffusion of the diffused light.

(2) -4 inclination angle

In addition, in the column structure, it is preferable that the columnar material 12a, etc. are held at a constant inclination angle with respect to the film thickness direction of the light diffusion control film.

This is because, by making the inclination angle of the columnar material constant, the incident light can be more stably reflected in the column structure, and the dependency of the incident angle derived from the column structure can be further improved.

More specifically, in the column structure, it is preferable that the inclination angle of the columnar surface with respect to the normal to the film surface is within a range of 0 to 80 degrees.

The reason for this is that when the inclination angle exceeds 80 DEG, the absolute value of the incidence angle of the active energy ray is increased along with this inclination angle. Therefore, the ratio of the reflection of the active energy ray at the interface between the air and the coating layer increases, and there is a case that it is necessary to irradiate the active energy ray of higher light intensity to form the column structure .

Therefore, the upper limit value of the inclination angle is more preferably 60 degrees or less, and more preferably 40 degrees or less.

The angle of inclination is perpendicular to the plane of the film and is defined by the normal to the film surface measured on the cross section when the film is cut by the plane cut along the axial line of the entire one columnar body along the axial line, Means the angle on the narrow side of the angle.

(3) Thickness

The thickness of the light diffusion control film in the present invention is preferably set to a value within a range of 10 to 700 mu m.

The reason for this is that when the thickness of the light diffusion control film is less than 10 mu m, incidence light advancing straightly in the column structure increases, and it becomes difficult to exhibit predetermined light diffusion characteristics. On the other hand, when the thickness of the light diffusion control film is more than 700 탆, when the composition for a light diffusion control film is irradiated with active energy rays to form a column structure, Direction is diffused, and it may become difficult to form a desired column structure. In addition, when applied to a display or the like, blur in the displayed image may easily occur.

Therefore, the lower limit of the film thickness of the light diffusion control film is more preferably 30 mu m or more, more preferably 50 mu m or more.

On the other hand, the upper limit of the film thickness of the light diffusion control film is more preferably 300 m or less, and more preferably 100 m or less.

(4) Characteristics

Regarding the characteristics of the optical diffusion control film in the present invention, it is preferable that the width of the incident angle region having a haze of 70% or more is a value of 60 DEG or more.

By limiting the width of the predetermined incident angle region in this manner, the incident light is efficiently introduced and uniformly diffused, thereby improving the brightness of the diffused light.

Therefore, it is preferable that the width of the incident angle region having a haze of 70% or more is a value of 80 DEG or more, more preferably 100 DEG or more.

With respect to the characteristics of the optical diffusion control film of the present invention, the straight line transmittance intensity PT in the case where the normal direction of the film surface is 0 deg. And the incident angle of 60 deg. Is set to a value within a range of 0.1 to 99%.

The reason for this is that if the median value is less than 0.1%, the transmittance of the film may deteriorate.

On the other hand, when the median value exceeds 99%, the incident angle range may be insufficient.

Therefore, the lower limit of the median value is more preferably 1% or more, and more preferably 5% or more.

The upper limit of the median value is more preferably 50% or less, and more preferably 15% or less.

The linearly transmitted light intensity is a value obtained by dividing the intensity of the outgoing light emitted at the same angle as that of the incident light by the intensity of the incident light as a whole.

With respect to the characteristics of the optical diffusion control film in the present invention, it is preferable that the unevenness of the linear transmitted light intensity P.T is within a range of 0.1 to 3.8%.

The reason for this is that when the unevenness becomes less than 0.1%, the control becomes difficult.

On the other hand, when such unevenness exceeds a value of 3.8%, there is a case where a shade occurs in the light diffusion state.

Therefore, the lower limit of the nonuniformity is more preferably 1% or more, and more preferably 2% or more.

Further, the upper limit of the median value is more preferably 3.5% or less, and more preferably 2.8% or less.

3. Process sheet

Further, in the laminate of the present invention, a process sheet may be laminated on a surface opposite to the side where the overlaminate film is laminated as one surface of the light diffusion control film.

Thus, the light diffusion control film can be effectively protected by sandwiching both sides of the light diffusion control film with the overlaminate film and the process sheet.

Here, the process sheet is a sheet to which a composition for a light diffusion control film is applied when a laminate is produced.

As such a process sheet, a conventional release film can be used. For example, a polyester film such as polyethylene terephthalate, polybutylene terephthalate, or polyethylene naphthalate, or a polyolefin film such as polypropylene or polyethylene, And a release agent such as a resin is applied to provide a release layer.

The thickness of such a process sheet is desirably a value within a range of usually 20 to 150 mu m.

[Second Embodiment]

An embodiment of the present invention is a method for producing a laminate as a first embodiment, which comprises the following steps (a) to (d).

(a) preparing a composition for a light diffusion control film comprising a high refractive index active energy ray curing component and a low refractive index active energy ray curing component

(b) a step of applying a composition for a light diffusion control film to a process sheet in the form of a film to form a coating layer

(c) a step of laminating an overlaminate film satisfying the relational expression (1) on the exposed surface of the applied layer

(d) a step of irradiating an active energy ray to the coated layer via an overlaminate film while moving the coated layer

Hereinafter, the second embodiment of the present invention will be described specifically with reference to the drawings, focusing on the differences from the first embodiment.

1. Process (a): Step of preparing a composition for a light diffusion control film

Step (a) is a step of preparing a predetermined composition for a light diffusion control film.

More specifically, it is a step of mixing components (A) to (B) described below and other components as desired.

In the mixing, the mixture may be stirred at room temperature, but from the viewpoint of improving the uniformity, it is preferable that the mixture is stirred under a warming condition of 40 to 80 캜 to obtain a homogeneous mixture.

It is also preferable to add a diluting solvent so as to obtain a desired viscosity suitable for coating.

(1) Component (A): high refractive index active energy ray hardening component

(1) The composition for a light diffusion control film in the present invention is characterized by comprising a high refractive index active energy ray curing component as the component (A).

The reason for this is that by including a high refractive index active energy component as the component (A), a predetermined difference in polymerization rate is generated between the low refractive index active energy ray curing component as a component (B) to be described later, (A) and the component (B) can be efficiently cured while being phase-separated efficiently.

As a result, a predetermined internal structure such as a columnar structure and a louver structure is formed at the time of photo-curing in spite of the uniform composition at the stage before the photo-curing, so that the light diffusion control film as a cured product, It is possible to impart an excellent diffusing property capable of diffusing.

(1) -1 Refractive index

It is preferable that the refractive index of the high refractive index active energy ray hardening component as the component (A) is within a range of 1.5 to 1.65.

The reason for this is that when the refractive index of the component (A) is less than 1.5, the difference from the refractive index of the low refractive index active energy ray curing component as component (B) becomes too small, and it becomes difficult to obtain effective light diffusion characteristics It is because. On the other hand, when the refractive index of the component (A) exceeds 1.65, the difference from the refractive index of the component (B) becomes large, but it may be difficult to form even the apparent compatibility with the component (B).

Therefore, the lower limit value of the refractive index of the component (A) is more preferably 1.55 or more, and more preferably 1.56 or more.

The upper limit of the refractive index of the component (A) is more preferably 1.6 or less, and more preferably 1.59 or less.

The refractive index of the above-mentioned component (A) means the refractive index of the component (A) before curing by light irradiation.

The refractive index can be measured in accordance with, for example, JIS K0062: 1992.

(1) -2 kinds

The kind of the component (A) is not particularly limited, but is preferably a (meth) acrylic acid ester containing a plurality of aromatic rings.

This is because, if such a compound is used, light curing can be achieved while more effectively phase-separating the component (A) and the component (B), and more excellent light diffusion characteristics can be obtained.

Examples of such a compound include (meth) acrylic acid esters such as biphenyl (meth) acrylate, naphthyl (meth) acrylate, anthracenyl (meth) acrylate, benzylphenyl Benzylphenyloxyalkyl (meth) acrylate, o-phenoxybenzyl (meth) acrylate, m-phenoxybenzyl (meth) acrylate, p-phenoxybenzyl (Meth) acrylate, etc., or a part thereof partially substituted with halogen, alkyl, alkoxy, halogenated alkyl, and the like.

The term "(meth) acrylic acid" means both of acrylic acid and methacrylic acid.

Further, as the component (A), a compound containing a biphenyl ring is more preferable, and a compound containing a biphenyl compound represented by the following general formula (1) is more preferable.

(Formula (1) of, R ¹ ~R ¹⁰ are, respectively and independently, at least one of R ¹ ~R ¹⁰ is a substituent represented by the following general formula (2), and the other is a hydrogen atom, a hydroxyl group, a carboxyl group , A substituent of any one of an alkyl group, an alkoxy group, a halogenated alkyl group, a hydroxyalkyl group, a carboxyalkyl group and a halogen atom)

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

The reason for this is that a predetermined difference in polymerization rate between the component (A) and the component (B) is generated by including a biphenyl compound having a specific structure as the component (A) It is presumed that the compatibility with the component (B) can be lowered to a predetermined range to lower the copolymerization of the two components.

Further, the refractive index in the region where the refractive index derived from the component (A) is relatively high is increased, and the difference from the refractive index in the region where the refractive index derived from the component (B) is relatively low is more easily adjusted to a predetermined value or more .

Specific examples of the biphenyl compound represented by the general formula (1) include compounds represented by the following general formulas (3) to (4).

(2) Component (B): low refractive index active energy ray hardening component

The composition for a light diffusion control film in the present invention is characterized by containing, as a component (B), a low refractive index active energy ray curing component.

The reason for this is that by including a low refractive index active energy ray curing component as the component (B), a predetermined difference in polymerization rate is generated between the high refractive index active energy ray curing component as the component (A) (A) and the component (B) can be efficiently cured while being phase-separated efficiently by inhibiting uniform copolymerization of both components.

As a result, a predetermined internal structure such as a columnar structure and a louver structure is formed at the time of photo-curing in spite of the uniform composition at the stage before the photo-curing, so that the light diffusion control film as a cured product, It is possible to impart an excellent diffusing property capable of diffusing.

(2) -1 Refractive index

The refractive index of the low refractive index active energy ray curing component as the component (B) is preferably within a range of 1.4 to 1.5.

This is because when the refractive index of the component (B) is less than 1.4, the difference from the refractive index of the component (A) becomes large, but the compatibility with the component (A) is extremely deteriorated, This is because it is sometimes difficult to carry out the present invention. On the other hand, when the refractive index of the component (B) exceeds 1.5, the difference between the refractive index of the component (A) and the refractive index of the component (B) becomes too small, making it difficult to obtain desired light diffusion characteristics.

Therefore, the lower limit value of the refractive index of the component (B) is more preferably 1.45 or more, and more preferably 1.46 or more.

The upper limit of the refractive index of the component (B) is more preferably 1.49 or less, and more preferably 1.48 or less.

The refractive index of the above-mentioned component (B) means the refractive index of the component (B) before curing by light irradiation.

The refractive index can be measured in accordance with, 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 0.01 or more.

The reason for this is that if the difference in the refractive index is less than 0.01, the angle of incidence of the incident light in the predetermined internal structure becomes narrower, so that the range of the light diffusion characteristic may be excessively narrowed. On the other hand, if the difference in the refractive index becomes excessively large, the compatibility of the component (A) and the component (B) becomes too poor, and it becomes difficult to form a predetermined internal structure.

Therefore, 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 more preferably 0.1 or more.

Further, the upper limit value of the difference between the refractive index of the component (A) and the refractive index of the component (B) is more preferably 0.5 or less, more preferably 0.2 or less.

The refractive index of the component (A) and the component (B) referred to herein means the refractive index of the component (A) and the component (B) before curing by light irradiation.

(2) -2 kinds

The type of the component (B) is not particularly limited, and examples thereof include urethane (meth) acrylate, (meth) acryl-based polymer having a (meth) acryloyl group in its side chain, Silicone resin, and unsaturated polyester resin. Of these, urethane (meth) acrylate is particularly preferable.

This is because, when urethane (meth) acrylate is used, the component (A) and the component (B) can be photo-cured while more effectively phase-separating them, and more excellent light diffusion characteristics can be obtained.

Further, (meth) acrylate means both of acrylate and methacrylate.

The urethane (meth) acrylate is preferably a compound containing at least (B1) an isocyanate group, (B2) a polyol compound, preferably a diol compound, particularly preferably a polyalkylene glycol, and (B3) a hydroxyalkyl Metha) acrylate.

The component (B) also includes an oligomer having repeating units of a urethane bond.

Examples of the compound containing at least two isocyanate groups as the component (B1) include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4- Aromatic polyisocyanates such as xylylene diisocyanate and 4,4'-diisocyanate methylene diphenyl (MDI), aliphatic polyisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate (IPDI), hydrogenated diphenylmethane diisocyanate Which is a reaction product of a buret resin, an isocyanurate compound and a low molecular active hydrogen-containing compound such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylol propane, castor oil, etc., (For example, a xylylene diisocyanate-based trifunctional adduct body) and the like.

Among the components forming the urethane (meth) acrylate, examples of the polyalkylene glycol as the component (B2) include polyethylene glycol, polypropylene glycol, polybutylene glycol, polyhexylene glycol and the like Among these, polypropylene glycol is particularly preferable.

This is because when polypropylene glycol is used as the component (B), it becomes a good soft segment in the cured product when it is cured, and the handling property and the mounting property of the obtained light diffusion control film can be effectively improved .

The weight average molecular weight of the component (B) can be controlled mainly by the weight average molecular weight of the component (B2). Here, the weight average molecular weight of the component (B2) is usually from 2,300 to 19,500, preferably from 4,300 to 14,300, and particularly preferably from 6,300 to 12,300.

Among the components forming urethane (meth) acrylate, examples of the hydroxyalkyl (meth) acrylate which is the component (B3) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl Hydroxybutyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl .

From the viewpoint of lowering the polymerization rate of the resultant urethane (meth) acrylate and forming a predetermined internal structure more efficiently, it is more preferable to use hydroxyalkyl methacrylate, more preferably 2-hydroxyethyl methacrylate Rate is more preferable.

(2) -3 Amount

(A): (B) component (weight ratio)) of the component (A) and the component (B) was 20 (parts by weight) when the total amount of the component : 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 within a range of 20 to 80 parts by weight.

This is because 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 and the refractive index derived from the component (B) It is excessively large in comparison with the width of the region, and it becomes difficult to obtain good light diffusion characteristics. On the other hand, when the compounding ratio of the component (B) exceeds 80 parts by weight, the presence of the component (A) in the component (B) becomes small and the refractive index of the component The width becomes excessively small as compared with the width of the region where the refractive index derived from the component (B) is relatively low, and it becomes difficult to obtain a good light diffusion property.

Therefore, when the total amount of the component (A) and the component (B) is 100 parts by weight, the lower limit of the blending ratio of the component (B) is more preferably 40 parts by weight or more, .

When the total amount of the component (A) and the component (B) is 100 parts by weight, the upper limit of the blending ratio of the component (B) is more preferably 70 parts by weight or less, Is more preferable.

(3) Component (C): Photopolymerization initiator

Further, in the composition for a light diffusion control film, it is preferable to contain a photopolymerization initiator as the component (C).

This is because when the composition for a light diffusion control film is irradiated with an active energy ray by containing a photopolymerization initiator, the component (A) and the component (B) can be photocured with more efficient phase separation This is because excellent light diffusion characteristics can be obtained.

Examples of the photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, Phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1- Methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, 4- (2-hydroxyethoxy) phenyl- 2- 2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4-diethylaminobenzophenone, dichlorobenzophenone, 2-methyl anthraquinone, 2-ethyl anthraquinone, 2-methylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethylketal, acetophenone dimethylketal, p-Dimethylamine benzoic acid Ester, oligo [2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propane], and one of these may be used alone, May be used.

The blending amount of the component (C) is preferably within a range of 0.2 to 20 parts by weight based on 100 parts by weight of the total amount of the component (A) and the component (B).

This is because if the blending amount of the component (C) is less than 0.2 parts by weight, the polymerization initiation point becomes low, so that it may become difficult to sufficiently cure the composition for a light diffusion control film. On the other hand, when the compounding amount of the component (C) exceeds 20 parts by weight, the yellowing of the light diffusion control film and the durability of the light diffusion control film tend to decrease.

Therefore, the lower limit of the amount of the component (C) is more preferably 0.5 parts by weight or more, and more preferably 1 part by weight or more.

The upper limit of the amount of the component (C) is more preferably 15 parts by weight or less, and further preferably 10 parts by weight or less.

(4) Other additives

Further, other additives may be added in the range not to impair the effect of the present invention.

Examples of other additives include antioxidants, antistatic agents, polymerization accelerators, polymerization inhibitors, infrared absorbers, plasticizers, diluting solvents, leveling agents and the like.

The content of the other additives is generally set to a value within a range of 0.01 to 5 parts by weight based on the total amount (100 parts by weight) of the components (A) and (B).

In addition, it is particularly preferable to blend an ultraviolet absorber as another additive.

This is because, when the active energy ray is irradiated, the active energy ray of a predetermined wavelength can be selectively absorbed in a predetermined range by blending the ultraviolet ray absorbent.

As a result, the curing of the composition for a light diffusion control film is not inhibited. For example, as shown in Fig. 5 (b), a predetermined internal structure formed inside the obtained light diffusion control film 10c 16) can be generated.

It is also preferable that the ultraviolet absorber is at least one selected from the group consisting of a hydroxyphenyltriazine type ultraviolet ray absorbing agent, a benzotriazole type ultraviolet ray absorbing agent, a benzophenone type ultraviolet ray absorbing agent and a hydroxybenzoate type ultraviolet ray absorbing agent.

This is because, if these ultraviolet absorbers are used, the curvature can be more clearly generated in the predetermined internal structure, and the range of the light diffusion property in the obtained light diffusion control film can be expanded more effectively.

That is, it has been confirmed that when these ultraviolet absorbers having a peak at a position closer to the wavelength of 365 nm, which is the frequency of the high-pressure mercury lamp, are bent at a small blending amount.

The blending amount of the ultraviolet absorber in the composition for a light diffusion control film is preferably set to a value of less than 2 parts by weight (excluding 0 part by weight), based on 100 parts by weight of the total amount of the components (A) and (B) .

This is because if the compounding amount of the ultraviolet absorber is 2 parts by weight or more, the curing of the composition for a light diffusion control film is inhibited and shrinkage wrinkles may occur on the surface of the film or no curing may occur at all. On the other hand, if the compounding amount of the ultraviolet absorber is excessively small, it may become difficult to generate sufficient bending with respect to the internal structure formed inside the light diffusion control film.

Therefore, the lower limit value of the ultraviolet absorber is more preferably 0.01 part by weight or more, more preferably 0.02 part by weight or more, relative to 100 parts by weight of the total amount of the components (A) and (B) .

The upper limit of the amount of the ultraviolet absorber to be added is more preferably 1.5 parts by weight or less, more preferably 1 part by weight or less, based on 100 parts by weight of the total amount of the components (A) and (B) desirable.

2. Process (b): The coating process

The step (b) is a step of coating the composition for a light diffusion control film onto the process sheet 2 in a film form to form the application layer 1, as shown in Fig. 6 (a).

As the process sheet, as described in the first embodiment, a normal release film can be used.

As a method of applying the composition for light diffusion film on the process sheet, for example, a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, a gravure coating method and the like can be used.

The thickness of the coating layer at this time is preferably within a range of 30 to 700 mu m.

3. Process (c): Lamination process

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. 6 (b).

That is, the step (c) is a step of holding the gap between the process sheet 2 and the overlaminate film 4, and laminating the coated layer 1 so as not to crumble.

4. Process (d): Activated energy irradiation process

6 (c), in the step (d), while the coating layer 1 is being moved, an active energy ray (parallel light) is applied to the coating layer 1 via the overlaminate film 4, Etc.) 60 to form a predetermined internal structure such as a columnar structure or a louver structure in the film to form the light diffusion control film 10. [

Hereinafter, as an example, a case of forming a columnar structure by irradiating the parallel light 60 will be described.

6 (c), the coating layer 1 formed on the process sheet 2 is irradiated with the parallel light 60 having high parallelism of light rays.

Here, the parallel light means substantially parallel light having no spread even if the traveling direction of the light is viewed from any direction.

More specifically, as shown in Fig. 6C, the irradiation light 70 from the point light source 102 can be made into the parallel light 60 by the lens 104, for example.

It is also preferable to set the parallelism of the irradiation light to a value of 10 DEG 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 set to a value of 5 DEG or less, and more preferably set to a value of 2 DEG or less.

7, the irradiation angle? X in the case where the angle of the normal to the surface of the coating layer 1 is 0 is set within a range of -80 to 80 degrees Value.

This is because, if the irradiation angle is outside the range of -80 to 80 °, the influence of reflection or the like on the surface of the coating layer 1 becomes large, and it becomes difficult to form a sufficient columnar structure in some cases.

The arrow MD in Fig. 7 indicates the moving direction of the coated layer.

In addition, ultraviolet rays are preferably used as the irradiation light for activating energy rays.

This is because, in the case of the electron beam, the polymerization rate is very high, and therefore the component (A) and the component (B) can not sufficiently phase-separate during the polymerization process, making it difficult to form the column structure. On the other hand, when compared with visible light and the like, since ultraviolet rays are rich in ultraviolet curing resin that can be cured by the irradiation and variations of the usable photopolymerization initiator, ultraviolet rays can broaden the selection range of the component (A) and the component It is because.

As the irradiation condition in the case of using ultraviolet rays as the active energy ray, it is preferable to set the peak illuminance on the surface of the coating layer within the range of 0.1 to 10 mW / cm 2.

This is because if the peak illuminance is less than 0.1 mW / cm 2, it may be difficult to form the column structure clearly. On the other hand, when the peak illuminance exceeds 10 mW / cm 2, the curing rate is estimated to be too high, and the column structure can not be formed effectively.

Therefore, the lower limit value of the peak roughness of the surface of the coating layer in the active energy ray irradiation is more preferably 0.3 mW / cm 2 or more, and more preferably 0.5 mW / cm 2 or more.

The upper limit of the peak roughness of the surface of the coating layer in the active energy beam irradiation is more preferably 8 mW / cm 2 or less, and more preferably 6 mW / cm 2 or less.

As the active energy ray, it is preferable to set the accumulated light quantity on the surface of the coating layer in the range of 5 to 200 mJ / cm 2 when ultraviolet rays are used.

This is because if the integrated amount of light is less than 5 mJ / cm 2, it may be difficult to extend the column structure from the upper side to the lower side sufficiently. On the other hand, when the integrated amount of light exceeds 200 mJ / cm 2, coloring may occur in the obtained light diffusion control film.

Therefore, the lower limit value of the accumulated light quantity on the surface of the coating layer in the active energy ray irradiation is more preferably 7 mJ / cm 2 or more, and more preferably 10 mJ / cm 2 or more.

Further, the upper limit value of the accumulated light quantity on the surface of the coating layer in the active energy ray irradiation is more preferably set to a value of 150 mJ / cm 2 or less, more preferably 100 mJ / cm 2 or less.

From the viewpoint of forming a column structure stably while maintaining mass productivity, the coating layer formed on the process sheet is moved at a speed in the range of 0.1 to 10 m / min when ultraviolet light is irradiated as active energy ray irradiation .

In particular, it is more preferable to move at a speed of 0.2 m / min or more, and more preferably to move at a speed of 8 m / min or less.

In the present invention, the internal structure formed in the light diffusion control film formed by photo-curing the composition for a light diffusion control film is not limited to the above-described column structure as far as it includes a high refractive index region and a low refractive index region no.

For example, in the case of forming the louver structure 20b shown in Fig. 5 (a), the coating layer 1 formed on the process sheet 2 is irradiated with irradiation light substantially in the case of viewing from one direction Parallel light, and in the case of viewing from the other direction, it may be irradiated with light which appears as unpolarized random light.

In the case of forming the predetermined internal structure 20d shown in Fig. 5 (c), the coated layer formed on the substrate is substantially parallel light when viewed from one direction, and when seen from the other direction, It is not the complete random light but the light adjusted to a certain degree of parallelism may be irradiated.

(Example)

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

As the overlaminate film, a biaxially stretched polyethylene terephthalate film roll (hereinafter sometimes referred to as &quot; Film A &quot;) having a thickness of 38 mu m and a length in the short side direction (width direction) of 1000 mm was prepared.

(1) Measurement of orientation angle?

The alignment angle? Of the prepared overlaminate film was measured.

Namely, an arbitrary portion in the longitudinal direction of the prepared overlaminate film was specified as the measurement point.

Next, 20 measurement points were measured for every 50 mm along a 1000 mm short-cut direction at a specific measurement point, and a long-axis direction was measured using a phase difference measurement device KOBRA-WR manufactured by Oji Scientific Co., Ltd. And the orientation angle? (°) in the direction of the slow axis was measured. The obtained results are shown in the characteristic curve A of Fig.

8 is a chart of a short direction position-orientation angle? Obtained by taking the position (mm) in the short direction of the overlaminate film on the abscissa and the orientation angle (?) On the ordinate.

Further, a middle value was calculated (°) and non-uniformity _{((φ max -φ min) /} (φ max + φ min) × 100) (%) of the more, the orientation of each obtained measurement value (φ). The obtained results are shown in Table 1.

(2) Measurement of surface roughness Rp and Ra

In addition, the arithmetic average roughness Ra and maximum peak height Rp of the prepared overlaminate films were measured.

Namely, the arithmetic mean roughness (Ra) (nm) of the prepared overlaminate film was measured in accordance with ANSI B46.1 using a surface profile measuring device WYKO NT110 (ANSI B46.1 standard) manufactured by Veeco Co., The 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

The haze of the prepared overlaminate film was measured.

That is, the haze (%) and the total light transmittance of the prepared overlaminate film were measured using a haze meter NDH-5000 manufactured by Nihon Denshoku Kogyo K.K. The obtained results are shown in Table 1.

2. Synthesis of low refractive index active energy ray curing component

2 moles of isophorone diisocyanate (IPDI) as a component (B1) and 2 mol of isophorone diisocyanate (IPDI) as a component (B3) were added to 1 mol of polypropylene glycol (PPG) having a weight average molecular weight of 9,200 as a component (B2) After 2 mols of methacrylate (HEMA) was accommodated, the reaction was carried out according to a conventional method to obtain polyether urethane methacrylate having a weight average molecular weight of 9,900 as component (B).

The weight average molecular weight of polypropylene glycol and polyether urethane methacrylate is a polystyrene reduced value measured by gel permeation chromatography (GPC) under the following conditions.

GPC measurement apparatus: HLC-8020 manufactured by TOSOH CORPORATION

GPC column: manufactured by TOSOH CORPORATION (hereinafter referred to as the order of passage)

  TSK guard column HXL-H

  TSK gel GMHXL (× 2)

  TSK gel G2000HXL

Measurement solvent: tetrahydrofuran

· Measuring temperature: 40 ℃

3. Preparation of composition for light diffusion control film

Next, 62.5 parts by weight of o-phenylphenoxyethoxyethyl acrylate (NK Ester A-LEN-10, manufactured by Shin-Nakamura Chemical Co., Ltd.) having a molecular weight of 268 and represented by the above formula (3) And 37.5 parts by weight of a polyether urethane methacrylate having a weight average molecular weight of 9,900 as a synthesized component (B), 100 parts by weight of the total of the components (A) and (B) Hydroxy-2-methyl-1-phenyl-propan-1-one was added thereto, followed by heating and mixing at 80 ° C to obtain a composition for a light diffusion control film.

The refractive indices of the component (A) and the component (B) were measured according to JIS K0062 using an Abbe refractometer (Abbe Refractometer DR-M2, Na light source, wavelength 589 nm) And 1.46.

4. Application Process

Next, the resulting composition for a light diffusion control film was applied to a peeled-off surface while drawing a transparent polyethylene terephthalate film roll as a process sheet having a peeled length of 1000 mm in a short direction, .

5. Lamination process

Next, the prepared overlaminate film was laminated on the exposed surface side of the applied layer by roll-to-roll.

Next, as shown in Fig. 6 (c), a parallel light having a parallelism of 2 or less is irradiated with a parallel ultraviolet light source (manufactured by E-Graphics Co., Ltd.) The coating layer was investigated so as to make it possible.

At that time, the peak illuminance was 1.08 mW / cm 2, the accumulated light intensity 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 peak illuminance and the accumulated light amount were measured by placing a UV meter (ultraviolet light measuring apparatus UVPF-A1, manufactured by Eye Graphics Co., Ltd.) with a photoreceptor at the position of the coating layer.

The film thickness of the light diffusion control film was measured using a static pressure gauge (TECLOCK PG-02J manufactured by Takara Shuzo Co., Ltd.).

Fig. 9 (a) shows a cross-sectional photograph of a light diffusion control film having the obtained column structure cut parallel to the moving direction of the coating layer and perpendicular to the film surface.

The length of the columnar structure in the film thickness direction was 60 占 퐉, and the inclination angle thereof was 7 占.

Cutting of the light diffusion control film was performed using a razor, and photographing of a section was performed by reflection observation using a digital microscope VHX-1000 manufactured by Keyence Corporation.

6. Evaluation

(1) Measurement of pitch angle haze

The width of the obtained light diffusion control film was measured.

That is, a specimen (120 mm width) on a strip along a longitudinal direction was cut out from an arbitrary portion of the obtained process sheet / optical diffusion control film / overlaminate film laminate, , And haze value (%) 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 set as the center point in the direction of the short side of the light diffusion control film in the test piece.

10A, the reference light was incident from the process sheet side of the test piece, and the incident angle of the reference light was changed along the longitudinal direction of the light diffusion control film to perform measurement. The obtained results are shown in the characteristic curve A of Fig. 10 (b).

10 (b) is an incidence angle-declination haze chart in which the horizontal axis represents the angle of incidence (degrees) of the reference light and the vertical axis represents the angle of haze (%). 10 (b), the width of the incident angle region having a haze of 70% or more was calculated and shown in Table 1.

Therefore, from the characteristic curve A, it is possible to confirm the property that the degree of light diffusion differs depending on the incidence angle, that is, the dependence of the incidence angle (characteristic curve B: Example 2, characteristic curve C: the same as in Comparative Example 1).

(2) Measurement of Straight Transmitted Light Intensity P.T

The linearly transmitted light intensity of the obtained light diffusion control film was measured.

That is, 20 measurement points were measured every 50 mm along the 1000 mm of the short side of the same test piece as that used in the measurement of the goniometric haze, and the measurement points were measured using a gyroscopic colorimeter VC-2 manufactured by Suga Shikenki Co., Ltd. And the straight transmission light intensity PT (%) was measured.

At this time, as shown in Fig. 11 (a), light was incident on the side of the process sheet of the test piece from a direction inclined by 60 占 opposite to the direction of inclination of the columnar material in the light diffusion control film . The obtained results are shown in the characteristic curve A of Fig. 11 (b).

11 (b) is a chart of a short-directional position-straight transmission light intensity chart in which the horizontal axis represents the position (mm) in the short direction of the light diffusion control film and the vertical axis represents the straight transmission light intensity (%).

Further, the obtained measurement value was calculated look straight median transmitted light intensity of the PT (%) and non-uniformity _{((PT max -PT min) /} (PT max + PT min) × 100) (%). The obtained results are shown in Table 1.

[Example 2]

In Example 2, in the same manner as in Example 1, except that a biaxially stretched polyethylene terephthalate film roll (hereinafter sometimes referred to as film B) having a thickness of 38 mu m and a length in the direction of the short side of 1000 mm was used as the overlaminate film A sieve was prepared and evaluated. The obtained results are shown in Table 1, the characteristic curve B in Fig. 8, the sectional photograph in Fig. 9 (b), the characteristic curve B in Fig. 10 (b), and the characteristic curve B in Fig. 11 (b), respectively.

[Comparative Example 1]

In Comparative Example 1, except that a biaxially stretched polyethylene terephthalate film roll (hereinafter sometimes referred to as &quot; Film C &quot;) having a thickness of 75 mu m and a length in a short direction of 1000 mm was used as an overlaminate film, Similarly, a laminate was prepared and evaluated. The obtained results are shown in Table 1, the characteristic curve C in FIG. 8, the sectional photograph in FIG. 9C, the characteristic curve C in FIG. 10B and the characteristic curve C in FIG.

[Table 1]

As described above, according to the present invention, the nonuniformity of the orientation angle in the slow axis direction measured along the predetermined direction in the plane of the overlaminate film is set to a value within a predetermined range, It is possible to uniformly form the internal structure even in the case of, or in the case of,

As a result, a uniform light diffusion control film can be obtained regardless of the position in the film plane of the light diffusion property.

Therefore, it is expected that the optical diffusion control film obtained by the present invention contributes significantly to the enhancement of the quality of liquid crystal display devices, projection screens, and the like.

1: Coating layer 2: substrate
2 ': other substrate 10: anisotropic light diffusion adhesive sheet
10a: isotropic light diffusion control film 10b to 10d: light diffusion control film
12, 12b to 12d: a region having a relatively high refractive index (including a plate-shaped region having a relatively high refractive index)
12a: columnar material having a relatively high refractive index
14, 14a to 14d: regions having a relatively low refractive index (including a plate-like region having a relatively low refractive index)
16: bend 20: internal structure
20a ': boundary surface 20a: column structure
20b: louver structure 20c: curved column structure
20d: predetermined internal structure 60: parallel light
70: Radiation from a point light source 100:
102: point light source 104: lens

Claims (7)

A laminate obtained by laminating an overlaminate film 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 and the high refractive index region has an internal structure formed by extending in a thickness direction,
When the maximum value of the orientation angle? (Degrees) in the slow axis direction based on the long direction is measured along the short side direction of the overlaminate film as? _Max and the minimum value is defined as? _Min Satisfies the following relational expression (1).
_{(φ max -φ min) / (} φ max + φ min) × 100 <12 (%) (1) The method according to claim 1,
Wherein the length of the overlaminate film in the direction of the short side is set to a value within a range of 100 to 10000 mm. 3. The method according to claim 1 or 2,
Wherein the median value of the orientation angle? Of the overlaid film in the slow axis direction is within a range of 45 to 135 占. 4. The method according to any one of claims 1 to 3,
And the film thickness of the overlaminate film is set to a value within a range of 5 to 5000 占 퐉. 5. The method according to any one of claims 1 to 4,
The internal structure of the light diffusion control film includes a column structure formed by laminating a plurality of columnar materials having a relatively high refractive index in a film thickness direction in a region having a relatively low refractive index . 6. The method according to any one of claims 1 to 5,
Wherein the internal structure of the light diffusion control film includes a louver structure in which a plurality of plate-shaped regions having different refractive indexes are alternately arranged in any one direction along the film plane. A method for producing a laminated body according to any one of claims 1 to 6,
A process for producing a laminated body, comprising the steps (a) to (d).
(a) preparing a composition for a light diffusion control film comprising a high refractive index active energy ray curing component and a low refractive index active energy ray curing component
(b) a step of applying the composition for a light diffusion control film to a process sheet in the form of a film to form a coating layer
(c) a step of laminating an overlaminate film satisfying the relational expression (1) on the exposed surface of the coated layer
(d) a step of irradiating an active energy ray to the coated layer via the overlaminate film while moving the coated layer

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