JP5926941B2 - Anisotropic light diffusion film composition and anisotropic light diffusion film - Google Patents

Description

The present invention relates to an anisotropic light diffusing film composition and an anisotropic light diffusing film.
In particular, an anisotropic light diffusing film composition capable of obtaining an anisotropic light diffusing film having good incident angle dependency in light transmission and diffusion and a wide light diffusing incident angle region, and anisotropic light obtained by photocuring the same It relates to a diffusion film.

Conventionally, in a liquid crystal display device, it is possible to recognize a predetermined image using light emitted from a light source (internal light source) provided inside the device.
However, in recent years, with the widespread use of mobile phones, in-vehicle TVs, etc., the opportunity to view the liquid crystal display screen outside has increased, and accordingly, the light intensity from the internal light source has been defeated by the external light, and the predetermined screen has been visually recognized. The problem that it becomes difficult to do arises.
In mobile applications such as mobile phones, the power consumption of the internal light source of the liquid crystal display device accounts for a large proportion of the total power consumption. The problem has arisen.

Therefore, in order to solve these problems, a reflection type liquid crystal display device using external light as part of a light source has been developed.
Such a reflective liquid crystal display device uses external light as part of the light source, so that the stronger the external light, the clearer the image can be recognized and the more effective the power consumption of the internal light source. Can be suppressed.

Further, in such a reflection type liquid crystal display device, the external light is efficiently transmitted and taken into the liquid crystal display device, and the external light is effectively used as a part of the light source. Providing an anisotropic light diffusion film for diffusing has been proposed (for example, Patent Document 1).
More specifically, Patent Document 1 discloses a liquid crystal cell in which a liquid crystal layer 1105 is sandwiched between an upper substrate 1103 and a lower substrate 1107, as shown in FIGS. A liquid crystal device (1112) having a light reflection plate 1110 provided on the substrate 1107 side and a light control plate (anisotropic light diffusion film) 1108 provided between the liquid crystal layer 1105 and the light reflection plate 1110 is disclosed. Has been.
A light control plate 1108 is provided to selectively scatter light incident at a predetermined angle and transmit light incident at an angle other than the predetermined angle. The light control plate 1108 is incident at a predetermined angle. The scattering axis direction 1121 obtained by projecting the direction in which light is selectively scattered onto the surface of the light control plate 1108 is arranged in the liquid crystal cell so as to be in the direction of about 6 o'clock in the liquid crystal cell plane.

  Various forms of anisotropic light diffusing films used in reflective liquid crystal display devices are known. In particular, in the film surface direction, an elongated plate-like high refractive index region and an elongated plate-like low-reflection film are used. Anisotropic light diffusion film with a louver structure that can control the light direction and adjust the light dispersibility in the film by alternately arranging the refractive index regions in parallel is widely used. (For example, Patent Documents 2 to 4).

  That is, Patent Document 2 discloses a film-shaped composition containing a plurality of compounds having a polymerizable carbon-carbon double bond, which is obtained by irradiating ultraviolet rays from a specific direction and curing the composition. In the light control film (anisotropic light diffusing film) that selectively scatters only the incident light, at least one compound contained in the composition includes a plurality of aromatic rings and one polymerizable carbon-carbon double bond. Discloses a light control film characterized by being a compound having in the molecule thereof.

  Patent Document 3 discloses a fluorene compound (A) having a polymerizable carbon-carbon double bond in the molecule, a cationic polymerizable compound (B) having a refractive index different from that of the fluorene compound (A), and A photocurable composition containing a photocationic polymerization initiator (C) and a light control film formed by curing the photocurable composition are disclosed.

  Further, Patent Document 4 includes at least (A) a bisphenol A type epoxy resin or brominated bisphenol A type epoxy resin represented by the general formula (7), and (B) an ethylenically unsaturated bond in the structural unit. An anisotropic light diffusing film comprising a radically polymerizable compound containing at least one, (D) a photopolymerization initiator that generates radical species by actinic radiation, and (E) a thermal polymerization initiator that generates cationic species by heat. Compositions and anisotropic light diffusion films produced using the same are disclosed. More specifically, at room temperature, (B) the compound having radical polymerizability has a refractive index of (A) bisphenol A type epoxy resin or brominated bisphenol A type epoxy resin and (C) at least one cationic polymerization in the molecule. An anisotropic light diffusing film composition characterized by being lower than a compound having a functional group and an anisotropic light diffusing film produced using the same are disclosed.

(In the general formula (7), R represents a hydrogen atom or a bromine atom, and the repeating number p represents a natural number.)

Japanese Patent No. 3480260 (Claims) JP 2006-350290 A (Claims) JP 2008-239757 A (Claims) Japanese Patent No. 3829601 (Claims)

However, the anisotropic light diffusing films disclosed in Patent Documents 1 to 4 not only have a small incident angle dependency in light transmission and diffusion, but also have a narrow light diffusing incident angle region. It was difficult to use light efficiently.
Although an attempt is made to laminate a plurality of anisotropic light diffusion films and widen the width of the light diffusion incident angle region, the sharpness of the image is reduced, the iris color (moire phenomenon) appears, There was a problem of being economically disadvantaged.

In view of the circumstances as described above, the present inventors have made extensive efforts to obtain a biphenyl compound having a specific structure and a polymerizable compound having a weight average molecular weight within a predetermined range. The present invention has been completed by finding that an anisotropic light diffusion film having good incident angle dependency can be obtained by photocuring after blending at a ratio.
That is, an object of the present invention is to provide a composition for an anisotropic light diffusing film that has a good incident angle dependency in light transmission and diffusion and that can provide an anisotropic light diffusing film with a wide light diffusing incident angle region, It is providing the anisotropic light-diffusion film formed by hardening | curing.

According to the present invention, a biphenyl compound having a refractive index represented by the following general formula (1) as a component (A) within a range of 1.55 to 1.6, and a weight average as a component (B) molecular weight Ri value der within the range of 5,000 to 15,000, the composition for an anisotropic light-diffusing film containing a urethane (meth) acrylate to the refractive index value within the range of 1.45 to 1.49, the The urethane (meth) acrylate as the component (B) is derived from the following components (a) to (c) as components, and the weight average molecular weight of the component (b) is 4,300. It is a value within the range of ˜14,300, and the content of the component (A) is set to a value within the range of 25 to 400 parts by weight with respect to 100 parts by weight of the component (B). An anisotropic light diffusing film composition is provided and described above. It is possible to solve the problem.
(A) Alicyclic diisocyanate
(B) Polyalkylene glycol
(C) Hydroxyalkyl (meth) acrylate

(In General Formula (1), R ^{1 to} R ¹⁰ are each independent, and any one of R ^{2 to} R ⁹ is a substituent represented by the following General Formula (2), and the rest is hydrogen. It is a substituent of any one of an atom, a hydroxyl group, a carboxyl group, an alkyl group, an alkoxy group, a halogenated alkyl group, a hydroxyalkyl group, a carboxyalkyl group and a halogen atom.)

(In General Formula (2), R ¹¹ is a hydrogen atom or a methyl group, carbon number n is an integer of 1 to 4, and repetition number m is an integer of 1 to 10.)

That is, since the component (A) includes a biphenyl compound having a specific structure and the weight average molecular weight of the component (B) is a value within a predetermined range, the polymerization rate of each component (for example, a photoradical) A predetermined difference in the polymerization rate), the compatibility between the component (A) and the component (B) is reduced to a predetermined range, and both components are prevented from being uniformly copolymerized. It is presumed that the copolymerizability between the components decreases.
Therefore, when photocured, the cured product of the component (A) and the cured product of the component (B) extend alternately, and in the film surface direction, an elongated plate-shaped high refractive index region and an elongated plate-shaped It is possible to efficiently form a louver structure in which the low refractive index regions are alternately arranged in parallel.
Therefore, the anisotropic light diffusing film composition of the present invention can provide an anisotropic light diffusing film having good incident angle dependency in light transmission and diffusion and having a wide light diffusion incident angle region.
Moreover, in General formula (1), since any one of R < ² > -R < ⁹ > is a substituent represented by General formula (2), (A) components are orientated in the step before photocuring. Thus, crystallization can be effectively prevented. As a result, in the photocuring stage, it is possible to aggregate and phase separate the component (A) and the component (B) at a fine level, and to obtain an anisotropic light diffusion film having a predetermined louver structure more efficiently. be able to.
Moreover, since the refractive index of (A) component is a value within the range of 1.55-1.6, the plate-shaped area | region derived from the (A) component in a louver structure, and the board derived from the (B) component The anisotropic light diffusion film having a predetermined louver structure can be more efficiently obtained by adjusting the difference from the refractive index of the shaped region more easily.
In addition, the refractive index of (A) component here means the refractive index of (B) component before hardening by light irradiation.
In addition, since the component (B) is urethane (meth) acrylate, the refractive index of the plate-like region derived from the component (A) in the louver structure and the refractive index of the plate-like region derived from the component (B) In addition to being able to more easily adjust the difference, the dispersion of the refractive index of the plate-like region derived from the component (B) is effectively suppressed, and an anisotropic light diffusing film having a predetermined louver structure can be more efficiently Can be obtained.
Furthermore, since the refractive index of the component (B) is a value in the range of 1.45 to 1.49, a plate-like region derived from the component (A) in the louver structure and a plate derived from the component (B) The anisotropic light diffusion film having a predetermined louver structure can be more efficiently obtained by adjusting the difference from the refractive index of the shaped region more easily.
In addition, the refractive index of (B) component here means the refractive index of (B) component before hardening by light irradiation.
In the present invention, the “film surface direction” means the xy plane direction when the film thickness direction is the z-axis.
In the present invention, “light diffusion incident angle region” means incident light corresponding to emitting diffused light when the angle of incident light from a point light source is changed with respect to the anisotropic light diffusing film. Means the angle range. Details of the light diffusion incident angle region will be described later.
In addition, “good incident angle dependency” is a distinction between an incident angle region (light diffusion incident angle region) with respect to a film where light diffusion of incident light occurs and other incident angle regions where light diffusion does not occur. Means that it is clearly controlled.
Further, the meaning of “anisotropic” in the present invention will be described later.

Moreover, when comprising the composition for anisotropic light-diffusion films of this invention, it is preferable to make the weight average molecular weight of (A) component into the value within the range of 200-2,500.
By comprising in this way, the copolymerizability of both components can be reduced more effectively and the anisotropic light-diffusion film provided with the predetermined | prescribed louver structure can be obtained more efficiently.

Moreover, as (C) component of this invention, while containing a photoinitiator, the content is 0.2-20 weight with respect to the total amount (100 weight%) of (A) component and (B) component. It is preferable to set the value within the range of%.
By comprising in this way, when an active energy ray is irradiated with respect to the composition for anisotropic light-diffusion films, a predetermined louver structure can be formed efficiently.

Another aspect of the present invention is an anisotropic light diffusing film which is a cured product of the composition for anisotropic light diffusing film, wherein the composition for anisotropic light diffusing film has the following general formula (1) as the component (A): ) and biphenyl compounds to a value within the range of 1.55 to 1.6 the refractive index represented by, Ri value der in weight average molecular weight of 5,000 to 15,000 as component (B) , see the urethane (meth) acrylate to the refractive index value within the range of 1.45 to 1.49, a free, (B) urethane as the component (meth) acrylate, the following as component (a) The component (b) is derived from the component and the weight average molecular weight of the component (b) below is a value within the range of 4,300 to 14,300, and the content of the component (A) is changed to the component (B) The range of 25 to 400 parts by weight with respect to 100 parts by weight. An anisotropic light-diffusing film, characterized in that the value of the inner.
(A) Alicyclic diisocyanate
(B) Polyalkylene glycol
(C) Hydroxyalkyl (meth) acrylate

(In General Formula (1), R ^{1 to} R ¹⁰ are each independent, and at least one of R ^{1 to} R ¹⁰ is a substituent represented by the following General Formula (2), and the rest is hydrogen. It is a substituent of any one of an atom, a hydroxyl group, a carboxyl group, an alkyl group, an alkoxy group, a halogenated alkyl group, a hydroxyalkyl group, a carboxyalkyl group and a halogen atom.)

(In General Formula (2), R ¹¹ is a hydrogen atom or a methyl group, carbon number n is an integer of 1 to 4, and repetition number m is an integer of 1 to 10.)

  That is, the anisotropic light diffusing film of the present invention is obtained by photocuring a predetermined composition for anisotropic light diffusing film, so that it has a good incident angle dependency in light transmission and diffusion, and light diffusion incidence. An anisotropic light diffusion film having a wide angle region can be obtained.

Moreover, when comprising the anisotropic light-diffusion film of this invention, it is preferable to make a film thickness into the value within the range of 100-500 micrometers.
By configuring in this way, it is possible to efficiently use external light as a light source even when applied to a reflective liquid crystal display device or the like as a single layer without laminating an anisotropic light diffusion film. In addition, it is possible to prevent problems such as a decrease in the sharpness of the displayed image and the appearance of an iris color.

FIG. 1A to FIG. 1B are diagrams for explaining an outline of a louver structure in an anisotropic light diffusion film. FIG. 2 is a diagram for explaining incident angle dependency and anisotropy in an anisotropic light diffusion film. FIGS. 3A to 3B are other views provided for explaining the incident angle dependency in the anisotropic light diffusion film. FIGS. 4A to 4C are diagrams for explaining the incident angle and the opening angle of the diffused light. FIGS. 5A to 5C are conceptual diagrams provided for explaining a method for producing an anisotropic light diffusion film. FIGS. 6A to 6B are diagrams provided for explaining the photocuring process. FIGS. 7A to 7C are views provided to explain the embodiment of the louver structure in the anisotropic light diffusion film of the present invention. FIG. 8 is a diagram for explaining an application example of the anisotropic light diffusion film of the present invention in a reflective liquid crystal display device. FIG. 9 is a diagram showing the relationship between the incident angle with respect to the anisotropic light diffusing films of Examples 1, 3, and 4 and the opening angle of the diffused light. FIGS. 10A to 10B are views for explaining a reflection type liquid crystal display device using a conventional anisotropic light diffusion film.

[First Embodiment]
In the first embodiment of the present invention, the biphenyl compound represented by the general formula (1) as the component (A) and the weight average molecular weight as the component (B) are in the range of 3,000 to 20,000. A composition for an anisotropic light diffusing film, wherein the content of the component (A) is a value within the range of 25 to 400 parts by weight with respect to 100 parts by weight of the component (B). It is a composition for anisotropic light-diffusion films characterized by these.
Hereinafter, a first embodiment of the present invention will be specifically described with reference to the drawings as appropriate.

1. Basic Principle of Anisotropic Light Diffusion Film First, the basic of an anisotropic light diffusion film (hereinafter simply referred to as an anisotropic light diffusion film) obtained by photocuring the composition for anisotropic light diffusion film of the present invention with reference to the drawings. The principle will be described.
First, FIG. 1A shows a top view (plan view) of the anisotropic light diffusing film 10, and FIG. 1B shows the anisotropic light diffusing film 10 shown in FIG. A cross-sectional view of the anisotropic light diffusing film 10 when cut in the vertical direction along A-A and viewing the cut surface from the arrow direction is shown.
As shown in the plan view of FIG. 1A, the anisotropic light diffusing film 10 includes a line-shaped plate-like region 12 having a relatively high refractive index derived from the component (A) in the film surface direction, B) Line-shaped plate-like regions 14 having a relatively low refractive index derived from the component are provided with louver structures 13 arranged alternately in parallel.
Further, as shown in the cross-sectional view of FIG. 1B, the high refractive index plate-like region 12 derived from the component (A) and the low refractive index plate-like region 14 derived from the component (B) are respectively It has a predetermined thickness and maintains the state of being alternately arranged in parallel even in the vertical direction of the anisotropic light diffusion film 10.

Thereby, as shown in FIG. 2, when the incident angle is in the light diffusion incident angle region, it is estimated that the incident light is diffused by the anisotropic light diffusion film 10.
That is, as shown in FIG. 1B, the incident angle of the incident light with respect to the anisotropic light diffusion film 10 is an angle within a predetermined range that is substantially parallel to the boundary surface 13 ′ of the louver structure 13, that is, When the angle is within the light diffusion incident angle region, the incident light (52, 54) moves along the film thickness direction while changing the direction in the high refractive index plate-like region 12 in the louver structure. By passing through, it is presumed that the traveling direction of light 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 anisotropic light diffusion film 10 (52 ′, 54 ′).
The light diffusing incident angle region is an angle region determined for each anisotropic light diffusing film depending on a refractive index difference, an inclination angle, or the like of the louver structure in the anisotropic light diffusing film.
Further, the direction change of incident light in the plate-like region 12 having a high refractive index in the louver structure is linearized by total reflection as shown in FIG. 1 due to the refractive index gradient in the plate-like region 12 having a high refractive index. In addition to the step index type that changes in a zigzag direction, a gradient index type that changes in a curved shape may be considered.
On the other hand, when the incident angle of the incident light with respect to the anisotropic light diffusing film 10 deviates from the light diffusing incident angle region, the incident light 56 is estimated to be transmitted as it is without being diffused by the anisotropic light diffusing film 10. (56 ').
With the above mechanism, the anisotropic light diffusing film 10 having the louver structure (12, 14) can exhibit incident angle dependence in light transmission and diffusion as shown in FIG. 2, for example.
In addition, as shown in FIG. 2, the anisotropic light diffusing film having the louver structure has a light exiting force even when the incident angle is different when the incident angle of the incident light is within the light diffusion incident angle region. Almost the same light diffusion can be performed on the surface side.
Therefore, it can be said that the anisotropic light diffusion film provided with the louver structure also has a light condensing function for concentrating light at a predetermined location.
In the present invention, “anisotropy” means, for example, in the diffused outgoing light when the light is diffused by the film as in the diffused light (52 ′, 54 ′) in FIG. It means the property that the degree of light diffusion (the shape of the spread of diffused light) in a plane parallel to the film varies depending on the direction in the same plane.
More specifically, in the case of the anisotropic light diffusion film 10 of the present invention, the direction of the louver structure extending mainly along the in-plane direction of the film 10 in a plane parallel to the film in the diffused emitted light. The light is diffused in the vertical direction, and the shape of the spread of the diffused light becomes substantially elliptical (52 ', 54').

Moreover, the relationship between the incident angle of the incident light with respect to an anisotropic light-diffusion film and the opening angle of the diffused light diffused by the anisotropic light-diffusion film is demonstrated using Fig.3 (a).
That is, in FIG. 3A, the horizontal axis represents the incident angle (°) of the incident light with respect to the anisotropic light diffusion film, and the vertical axis represents the opening angle (°) of the diffused light diffused by the anisotropic light diffusion film. A characteristic curve is shown.
As shown in FIGS. 4A to 4C, the incident angle θ <b> 1 means an angle (°) when the angle perpendicularly incident on the anisotropic light diffusion film 10 is 0 °.
More specifically, as described above, the incident light component contributing to the anisotropic light diffusion is a component perpendicular to the direction of the louver structure extending mainly in the film surface direction. The term “incident angle θ1” means the incident angle of a component perpendicular to the direction of the louver structure extending in the film surface direction. Further, at this time, the incident angle θ1 means an angle (°) when the angle with respect to the normal to the incident side surface of the anisotropic light diffusing film is 0 °.
Further, the spread light opening angle θ2 literally means the spread light opening angle (°).
Moreover, the larger the opening angle of the diffused light, the more effectively the incident light at the incident angle is diffused by the anisotropic light diffusion film.
Conversely, the smaller the opening angle of the diffused light, the light incident at the incident angle at that time is transmitted through the anisotropic light diffusing film as it is and does not diffuse.
A specific method for measuring the opening angle of the diffused light will be described in the examples.

As understood from the characteristic curve, if the anisotropic light diffusion film, the degree of light transmission and diffusion varies greatly depending on the incident angle, and the light diffusion incident angle region and the other incident angle region Can be clearly separated.
On the other hand, in the case of a film having no incident angle dependency, as shown in FIG. 3B, the change in the incident angle does not have a clear influence on the degree of light transmission and diffusion, and light diffusion The incident angle region cannot be identified.
In the present invention, as shown in FIG. 3 (a), the difference between the light diffusion incident angle region and the other incident angle regions is clear, and the anisotropic light diffusion has a wide light diffusion incident angle region. It aims at obtaining the film and the composition for anisotropic light-diffusion films which can obtain it.

2. (A) Component: Biphenyl Compound (1) Type The composition for anisotropic light diffusing film of the present invention is characterized by containing a biphenyl compound represented by the following general formula (1) as the component (A).

(In General Formula (1), R ^{1 to} R ¹⁰ are each independent, and at least one of R ^{1 to} R ¹⁰ is a substituent represented by the following General Formula (2), and the rest is hydrogen. It is a substituent of any one of an atom, a hydroxyl group, a carboxyl group, an alkyl group, an alkoxy group, a halogenated alkyl group, a hydroxyalkyl group, a carboxyalkyl group and a halogen atom.)

(In General Formula (2), R ¹¹ is a hydrogen atom or a methyl group, carbon number n is an integer of 1 to 4, and repetition 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 component (A), the polymerization rate of component (A) is made faster than the polymerization rate of component (B), and polymerization between these components is performed. This is because it is presumed that a predetermined difference is caused in the speed, and the copolymerizability of both components can be effectively reduced.
As a result, when photocured, a so-called louver structure in which the plate-like regions derived from the component (A) and the plate-like regions derived from the component (B) extend alternately can be formed efficiently. .
Moreover, it is presumed that the compatibility with the component (B) is reduced to a predetermined range by including a biphenyl compound having a specific structure as the component (A), and the louver structure is formed more efficiently. can do.
Furthermore, by including a biphenyl compound having a specific structure as the component (A), the refractive index of the plate-like region derived from the component (A) in the louver structure is increased, and the plate shape derived from the component (B) The difference from the refractive index of the region can be adjusted to a value greater than a predetermined value.
Therefore, by including a biphenyl compound having a specific structure as the component (A), coupled with the characteristics of the component (B) described later, a different louver structure having plate-like regions with different refractive indexes extending alternately. An isotropic light diffusion film can be obtained efficiently.
Therefore, it is possible to obtain an anisotropic light diffusion film having good incident angle dependency in light transmission and diffusion and having a wide light diffusion incident angle region.

Moreover, when R < ¹ > -R < ¹⁰ > in General formula (1) contains either an alkyl group, an alkoxy group, a halogenated alkyl group, a hydroxyalkyl group, and a carboxyalkyl group, carbon number of the alkyl part is set. A value in the range of 1 to 4 is preferable.
The reason for this is that when the number of carbon atoms exceeds 4, the polymerization rate of the component (A) decreases, or the refractive index of the plate-like region derived from the component (A) in the louver structure becomes too low. This is because it may be difficult to efficiently form a predetermined louver structure in the anisotropic light diffusion film.
Therefore, when R ^{1 to} R ¹⁰ in the general formula (1) include any of an alkyl group, an alkoxy group, a halogenated alkyl group, a hydroxyalkyl group, and a carboxyalkyl group, the number of carbon atoms in the alkyl portion is determined. A value in the range of 1 to 3 is more preferable, and a value in the range of 1 to 2 is more preferable.

Moreover, it is preferable that the substituent selected in R < ¹ > -R < ¹⁰ > in General formula (1) is a substituent other than a halogenated alkyl group or a halogen atom, ie, a halogen-free substituent.
This is because dioxins are prevented from being generated when the anisotropic light diffusion film is incinerated and the like, which is preferable from the viewpoint of environmental protection.
Incidentally, in an anisotropic light diffusing film having a conventional louver structure, in order to obtain a predetermined louver structure, it is general that halogen substitution is performed in the monomer component for the purpose of increasing the refractive index of the monomer component. .
In this regard, the biphenyl compound represented by the general formula (1) can have a high refractive index even when halogen substitution is not performed.
Therefore, if it is an anisotropic light-diffusion film formed by photocuring the composition for anisotropic light-diffusion films of this invention, even if it is a case where halogen is not included, favorable incident angle dependence can be exhibited.

Moreover, it is preferable that any one of R < ² > -R < ⁹ > in General formula (1) is a substituent represented by General formula (2).
The reason for this is that by setting the position of the substituent represented by the general formula (2) to a position other than R ¹ and R ¹⁰ in the biphenyl ring, the components (A) are orientated at the stage before photocuring. , Crystallization can be effectively prevented.
As a result, in the photocuring stage, it is possible to aggregate and phase separate the component (A) and the component (B) at a fine level, and to obtain an anisotropic light diffusion film having a predetermined louver structure more efficiently. Because it can.
Further, from the same viewpoint, it is particularly preferable that any one of R ³ , R ⁵ , R ⁶ and R ^{8 in} the general formula (1) is a substituent represented by the general formula (2).

Moreover, the repeating number m in the substituent represented by the general formula (2) is usually an integer of 1 to 10.
The reason for this is that when the number of repetitions m exceeds 10, the oxyalkylene chain connecting the polymerization site and the biphenyl ring becomes too long, which may inhibit the polymerization of the components (A) at the polymerization site. Because.
Therefore, the repeating number m in the substituent represented by the general formula (2) is more preferably an integer of 1 to 4, and particularly preferably an integer of 1 to 2.
From the same viewpoint, the carbon number n in the substituent represented by the general formula (2) is usually an integer of 1 to 4.
In addition, considering the position of the polymerizable carbon-carbon double bond that is the polymerization site is too close to the biphenyl ring, the biphenyl ring becomes sterically hindered, and the polymerization rate of the component (A) decreases, The carbon number n in the substituent represented by the general formula (2) is more preferably an integer of 2 to 4, and particularly preferably an integer of 2 to 3.

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

(2) Weight average molecular weight Moreover, it is preferable to make the weight average molecular weight of the biphenyl compound which has a specific structure as (A) component into the value within the range of 200-2,500.
The reason for this is that both the weight average molecular weight of the biphenyl compound having a specific structure as the component (A) and the weight average molecular weight of the polymerizable compound as the component (B) described later are within a predetermined range. It is because it is estimated that the copolymerizability of a component can be reduced more effectively.
As a result, it is possible to more efficiently form a louver structure in which plate-like regions derived from the component (A) and plate-like regions derived from the component (B) extend alternately when photocured. .
That is, when the weight average molecular weight of the component (A) is less than 200, the position of the biphenyl ring and the position of the polymerizable carbon-carbon double bond are too close, and the polymerization rate decreases due to steric hindrance. This is because the polymerization rate of the component (B) is close and copolymerization with the component (B) is likely to occur. On the other hand, when the weight average molecular weight of the component (A) exceeds 2,500, the difference in molecular weight with the component (B) decreases, the polymerization rate of the component (A) decreases, and the component (B) This is because it is estimated that the polymerization rate is close and copolymerization with the component (B) is likely to occur, and as a result, it may be difficult to efficiently form a louver structure.
Therefore, the weight average molecular weight of the biphenyl compound having a specific structure as the component (A) is more preferably set to a value within the range of 240 to 1,500, and a value within the range of 260 to 1,000. More preferably.
In addition, the weight average molecular weight of (A) component can be calculated | required from the calculated value obtained from a molecular composition and the atomic weight of a constituent atom.
Moreover, the weight average molecular weight of (A) component can also be measured using a gel permeation chromatography (GPC).
Moreover, although (A) component may use together 2 or more types from which molecular structure and a weight average molecular weight differ, from a viewpoint of suppressing the dispersion | variation in the refractive index of the plate-shaped area | region originating in (A) component in a louver structure. It is preferable to use only one type.
That is, when the compatibility with the component (B) in the component (A) is low, for example, when the component (A) is a halogen compound, the third component for compatibilizing the component (A) with the component (B) In other cases, other components (A) (for example, non-halogen compounds) are used in combination.
However, in this case, due to the influence of the third component, the refractive index in the plate-like region having a high refractive index derived from the component (A) may vary or be easily lowered.
As a result, the refractive index difference from the plate-like region having a low refractive index derived from the component (B) may become non-uniform or may be excessively lowered.
Therefore, it is preferable to select a monomer component having a high refractive index that is compatible with the component (B) and use it as the sole component (A).
For example, since the biphenyl compound represented by the formula (3) as the component (A) has a low viscosity, it has compatibility with the component (B), so it is used as a single component (A). can do.

(3) Refractive index Moreover, it is preferable to make the refractive index of the biphenyl compound which has a specific structure as (A) component into the value within the range of 1.5-1.65.
This is because the refractive index of the plate-like region derived from the component (A) and the plate-like region derived from the component (B) in the louver structure is set by setting the refractive index of the component (A) to a value within this range. This is because an anisotropic light diffusing film having a predetermined louver structure can be more efficiently obtained by adjusting the difference between and the above.
That is, when the refractive index of the component (A) is less than 1.5, the difference from the refractive index of the component (B) becomes too small, and it may be difficult to obtain a desired incident angle dependency. Because there is. 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) increases, but the compatibility with the component (B) may be difficult. Because.
Therefore, the refractive index of the biphenyl compound having a specific structure as the component (A) is more preferably set to a value within the range of 1.55 to 1.6, and within the range of 1.56 to 1.59. More preferably, it is a value.
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.

(4) Content Further, the content of the biphenyl compound having a specific structure as the component (A) is in the range of 25 to 400 parts by weight with respect to 100 parts by weight of the polymerizable compound as the component (B) described later. It is characterized by being a value within.
The reason for this is that by setting the content of component (A) to a value within this range, both components will be copolymerized when irradiated with light while maintaining miscibility with component (B). This is because the predetermined louver structure can be efficiently formed.
That is, when the content of the component (A) is less than 25 parts by weight, the ratio of the component (A) to the component (B) decreases, and the plate-like region derived from the component (A) in the louver structure This is because the width becomes excessively small as compared with the width of the plate-like region derived from the component (B), and it may be difficult to obtain a louver structure having good incident angle dependency. Moreover, it is because the length of the louver in the thickness direction of the anisotropic light diffusing film becomes insufficient and the light diffusibility may not be exhibited. On the other hand, when the content of the component (A) exceeds 400 parts by weight, the ratio of the component (A) to the component (B) increases, and the plate-like region derived from the component (A) in the louver structure This is because it may become difficult to obtain a louver structure having a good incident angle dependence, on the contrary, the width of the plate is excessively larger than the width of the plate-like region derived from the component (B). is there. Moreover, it is because the length of the louver in the thickness direction of the anisotropic light diffusing film becomes insufficient and the light diffusibility may not be exhibited.
Therefore, the content of the biphenyl compound having a specific structure as the component (A) is set to a value within the range of 40 to 300 parts by weight with respect to 100 parts by weight of the polymerizable compound as the component (B). More preferably, the value is more preferably in the range of 50 to 200 parts by weight.

3. (B) Component: Polymerizable Compound (1) Type The polymerizable compound as the component (B) may be any polymerizable compound such as cationic polymerizable, anionic polymerizable and radical polymerizable. Since the same polymerization system as the component can be used, the component (C) described later can be shared, and handling becomes easy, it is preferable to use a radically polymerizable compound.
Examples of the radical polymerizable polymerizable compound include urethane (meth) acrylate, (meth) acrylic polymer having (meth) acryloyl group in the side chain, (meth) acryloyl group-containing silicone resin, and unsaturated polyester. Examples of the resin include urethane (meth) acrylate.
The reason for this is that if it is urethane (meth) acrylate, the difference between the refractive index of the plate-like region derived from the component (A) in the louver structure and the refractive index of the plate-like region derived from the component (B) is more In addition to being easily adjustable, it is possible to effectively suppress the variation in the refractive index of the plate-like region derived from the component (B) and to obtain an anisotropic light diffusion film having a predetermined louver structure more efficiently. It is.
Therefore, in the following, urethane (meth) acrylate as the component (B) will be mainly described.
In addition, (meth) acrylate means both acrylate and methacrylate.

First, urethane (meth) acrylate is formed from (a) a compound containing at least two isocyanate groups, (b) polyalkylene glycol, and (c) hydroxyalkyl (meth) acrylate.
Among these, as the compound containing at least two isocyanate groups as component (a), for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate Arocyclic polyisocyanates such as aromatic polyisocyanates such as 1,4-xylylene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate (IPDI), hydrogenated diphenylmethane diisocyanate, etc. Isocyanates and their biurets, isocyanurates, and adducts that are a reaction with low molecular weight active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, castor oil (for example, Xylylene diisocyanate Over preparative based trifunctional adduct), and the like.

Moreover, among the above-mentioned, it is especially preferable that it is an alicyclic polyisocyanate.
This is because, in the case of alicyclic polyisocyanates, compared to aliphatic polyisocyanates, it is easy to provide a difference in the reaction rate of each isocyanate group due to the conformation and the like.
This suppresses that the (a) component reacts only with the (b) component, or the (a) component reacts only with the (c) component, and the (a) component is replaced with the (b) component and (C) It can react reliably with a component and generation | occurrence | production of an extra by-product can be prevented.
As a result, variation in the refractive index in the plate-like region derived from the component (B) in the anisotropic light diffusion film, that is, the plate-like region having a low refractive index, can be effectively suppressed.

Moreover, if it is an alicyclic polyisocyanate, compared with an aromatic polyisocyanate, the polymerizable compound as (B) component obtained, and the biphenyl compound which has a specific structure as (A) component The compatibility can be reduced to a predetermined range, and the louver structure can be formed more efficiently.
Furthermore, if it is an alicyclic polyisocyanate, compared with an aromatic polyisocyanate, since the refractive index of the polymeric compound as a (B) component obtained can be made small, as (A) component as The difference from the refractive index of the biphenyl compound having a specific structure can be increased, and a louver structure excellent in anisotropy can be formed more efficiently.
Of these alicyclic polyisocyanates, alicyclic diisocyanates containing only two isocyanate groups are preferred.
This is because if it is an alicyclic diisocyanate, it can react quantitatively with the component (b) and the component (c) to obtain a single component (B).
As such an alicyclic diisocyanate, isophorone diisocyanate (IPDI) can be particularly preferably mentioned.
This is because an effective difference can be provided in the reactivity of the two isocyanate groups.

Among the components that form urethane (meth) acrylate, examples of the polyalkylene glycol (b) include polyethylene glycol, polypropylene glycol, polybutylene glycol, polyhexylene glycol, and the like. Particularly preferred is glycol.
This is because polypropylene glycol can be handled without a solvent because of its low viscosity.
Moreover, if it is a polypropylene glycol, when (B) component is hardened, it will become a favorable soft segment in the said hardened | cured material, and the handling property and mounting property of an anisotropic light-diffusion film can be improved effectively. It is.
In addition, the weight average molecular weight of (B) component can be mainly adjusted with the weight average molecular weight of (b) component. Here, the weight average molecular weight of (b) component is 2,300-19,500 normally, Preferably it is 4,300-14,300, Especially preferably, it is 6,300-12,300.

Moreover, as a hydroxyalkyl (meth) acrylate which is (c) 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 louver structure, hydroxyalkyl methacrylate is more preferable, and 2-hydroxyethyl methacrylate is particularly preferable. Is more preferable.

Moreover, the synthesis | combination of the urethane (meth) acrylate by (a)-(c) component can be implemented in accordance with a conventional method.
At this time, the blending ratio of the components (a) to (c) is preferably set to a ratio of (a) component: (b) component: (c) component = 1-5: 1: 1-5 in molar ratio. .
The reason for this is that by setting such a blending ratio, one isocyanate group of the component (a) reacts with and binds to two hydroxyl groups of the component (b), and two components (a) This is because it is possible to efficiently synthesize urethane (meth) acrylate in which the hydroxyl group of component (c) reacts with and binds to the other isocyanate group possessed by each.
Therefore, the mixing ratio of the components (a) to (c) is more preferably set to a ratio of (a) component: (b) component: (c) component = 1-3: 1: 1-3 in molar ratio. Preferably, the ratio is 2: 1: 2.

(2) Weight average molecular weight Moreover, let the weight average molecular weight of the polymeric compound as (B) component be the value within the range of 3,000-20,000.
This is because, by setting the weight average molecular weight of the polymerizable compound as the component (B) within a predetermined range, a predetermined difference is caused in the polymerization rate of the component (A) and the component (B). This is because the polymerizability can be effectively reduced.
As a result, when photocured, a louver structure in which plate-like regions derived from the component (A) and plate-like regions derived from the component (B) extend alternately can be efficiently formed.
That is, when the weight average molecular weight of the component (B) is less than 3,000, the polymerization rate of the component (B) is increased to be close to the polymerization rate of the component (A). This is because polymerization may easily occur, and it may be difficult to efficiently form a louver structure. On the other hand, when the weight average molecular weight of component (B) exceeds 20,000, it is difficult to form a louver structure in which plate-like regions derived from component (A) and component (B) extend alternately. This is because the compatibility with the component (A) may be excessively lowered, and the component (A) may be precipitated at the application stage.
Therefore, it is more preferable that the weight average molecular weight of the polymerizable compound as the component (B) is a value within the range of 5,000 to 15,000, and a value within the range of 7,000 to 13,000. More preferably.
In addition, the weight average molecular weight of (B) component can be measured using a gel permeation chromatography (GPC).
Moreover, although (B) component may use together 2 or more types from which molecular structure and a weight average molecular weight differ, from a viewpoint of suppressing the dispersion | variation in the refractive index of the plate-shaped area | region originating in the (B) component in a louver structure. It is preferable to use only one type.
That is, when a plurality of components (B) are used, the refractive index in the plate-like region having a low refractive index derived from the component (B) varies or increases, and the refractive index derived from the component (A) is high. This is because the refractive index difference from the plate-like region may become non-uniform or excessively decrease.

(3) Refractive index Moreover, it is preferable to make the refractive index of the polymeric compound as a (B) component into the value within the range of 1.4-1.5.
This is because the refractive index of the plate-like region derived from the component (A) and the plate-like region derived from the component (B) in the louver structure is determined by setting the refractive index of the component (B) to a value within this range. This is because an anisotropic light diffusing film having a predetermined louver structure can be more efficiently obtained by adjusting the difference between and the above.
That is, 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, and the louver structure It is because there exists a possibility that it cannot form. 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, making it difficult to obtain the desired incident angle dependency. Because there is.
Therefore, the refractive index of the polymerizable compound as the component (B) is more preferably set to a value within the range of 1.45 to 1.49, and the value within the range of 1.46 to 1.48. Is more preferable.
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.

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.
This is because, by setting the difference in refractive index within a predetermined range, anisotropic light diffusion has a better incident angle dependency in light transmission and diffusion and a wider light diffusion incident angle region. This is because a film can be obtained.
That is, if the difference in refractive index is less than 0.01, the angle range where incident light is totally reflected in the louver structure is narrowed, so that the opening angle of diffused light may be excessively narrowed. is there. On the other hand, if the difference in refractive index becomes an excessively large value, the compatibility between the component (A) and the component (B) is too deteriorated, and the louver structure may not be formed.
Therefore, the difference between the refractive index of the component (A) and the refractive index of the component (B) is more preferably set to a value in the range of 0.05 to 0.5, More preferably, the value is within the range.
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.

(4) Content Further, the content of the polymerizable compound as the component (B) is set to a value within the range of 20 to 80% by weight with respect to 100% by weight of the total amount of the composition for anisotropic light diffusion film. It is preferable.
The reason for this is that when the content of the component (B) is less than 20% by weight, the ratio of the component (B) to the component (A) decreases, and the plate shape derived from the component (B) in the louver structure This is because the width of the region becomes excessively small as compared with the width of the plate-like region derived from the component (A), and it may be difficult to obtain a louver structure having good incident angle dependency. Moreover, it is because the length of the louver in the thickness direction of the anisotropic light diffusion film may be insufficient. On the other hand, when the content of the component (B) exceeds 80% by weight, the ratio of the component (B) to the component (A) increases, and the plate-like region derived from the component (B) in the louver structure This is because it may become difficult to obtain a louver structure having a good incident angle dependency, on the contrary, the width of the plate is excessively larger than the width of the plate-like region derived from the component (A). is there. Moreover, it is because the length of the louver in the thickness direction of the anisotropic light diffusion film may be insufficient.
Therefore, the content of the polymerizable compound as the component (B) is more preferably set to a value within the range of 30 to 70% by weight with respect to 100% by weight of the total amount of the composition for anisotropic light diffusion film, More preferably, the value is within the range of 40 to 60% by weight.

4). Photopolymerization initiator Moreover, in the composition for anisotropic light-diffusion films of this invention, it is preferable to contain a photoinitiator as (C) component as needed.
This is because a predetermined louver structure can be efficiently formed when the composition for anisotropic light diffusion film is irradiated with active energy rays by containing a photopolymerization initiator.
Here, the photopolymerization initiator refers to a compound that generates radical species by irradiation with active energy rays such as ultraviolet rays.

Examples of the photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, and 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-diethyl Minobenzophenone, 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 them may be used alone, or two or more of them may be used in combination.
In addition, as content in the case of containing a photoinitiator, it is set as the value within the range of 0.2-20 weight% with respect to 100 weight% of total amounts of (A) component and (B) component. Preferably, the value is in the range of 0.5 to 15% by weight, more preferably in the range of 1 to 10% by weight.

5. Other Additives Other additives can be appropriately added as long as the effects of the present invention are not impaired.
Examples of other additives include an antioxidant, an ultraviolet absorber, 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 set to a value within the range of 0.01 to 5% by weight with respect to 100% by weight of the total amount of the component (A) and the component (B). The value is more preferably in the range of 0.02 to 3% by weight, and further preferably in the range of 0.05 to 2% by weight.

[Second Embodiment]
2nd Embodiment of this invention is an anisotropic light-diffusion film formed by irradiating an active energy ray with respect to the composition for anisotropic light-diffusion films, Comprising: The composition for anisotropic light-diffusion films is as (A) component. A biphenyl compound represented by the general formula (1) and a polymerizable compound having a weight average molecular weight in the range of 3,000 to 20,000 as the component (B), and the component (A) It is an anisotropic light-diffusion film characterized by making content into the value within the range of 25-400 weight part with respect to 100 weight part of (B) component.
Hereinafter, the second embodiment of the present invention will be specifically described with reference to FIG. 5 with a focus on differences from the first embodiment.

1. Manufacturing method Hereinafter, the manufacturing method of the anisotropic light-diffusion film of this invention is demonstrated, However, The anisotropic light-diffusion film concerning this invention is not limited by the following manufacturing methods.

(1) Preparation process of composition for anisotropic light diffusion film The preparation process of the composition for anisotropic light diffusion film is a process of preparing a predetermined composition for anisotropic light diffusion film containing the component (A) and the component (B). is there.
More specifically, it is preferable to stir the component (A) and the component (B) under high temperature conditions of 40 to 80 ° C. to obtain a uniform mixed solution.
At the same time, other additives such as the component (C) are added to the mixed liquid as desired, and then stirred as necessary to make it uniform, and diluted as necessary to achieve the desired viscosity. It is preferable to obtain a solution of the composition for anisotropic light diffusion film by further adding a solvent.
In addition, since it is as having described in 1st Embodiment about the detail of each component, a mixture ratio, etc., it abbreviate | omits.

(2) Application process An application process is a process of forming the coating layer 1 by apply | coating the prepared composition for anisotropic light-diffusion films with respect to the process sheet | seat 2, as shown to Fig.5 (a).
Either a plastic film or paper can be used as the process sheet.
Among these, examples of the plastic film include polyester films such as polyethylene terephthalate films, polyolefin films such as polyethylene films and polypropylene films, cellulose films such as triacetyl cellulose films, and polyimide films.
Examples of the paper include glassine paper, coated paper, and laminated paper.

In addition, for the process sheet, a release layer is provided on the application surface side of the composition for anisotropic light diffusion film in the process sheet in order to facilitate peeling of the obtained anisotropic light diffusion film from the process sheet after photocuring. It is preferable to provide it.
Such a release layer can be formed using a conventionally known release agent such as a silicone release agent, a fluorine release agent, an alkyd release agent, or an olefin release agent.
In addition, it is preferable that the thickness of a process sheet | seat is normally set to the value within the range of 25-200 micrometers.

Examples of the method for applying the anisotropic light diffusion film composition on the process sheet include conventionally known methods such as knife coating, roll coating, bar coating, blade coating, die coating, and gravure coating. It can be done by a method.
At this time, the thickness of the coating layer is preferably set to a value within the range of 100 to 700 μm.

(3) Photocuring step The photocuring step is a step of photocuring the coating layer of the composition for anisotropic light diffusing film to make the coating layer an anisotropic light diffusing film.
That is, as shown in FIG. 5B, the active energy ray 50 composed only of direct light whose irradiation angle is controlled is irradiated onto the coating layer 1 formed on the process sheet 2.
More specifically, for example, as shown in FIG. 6A, an ultraviolet irradiation device 20 in which a condensing cold mirror 22 is provided on a linear ultraviolet lamp 25 (for example, a commercially available product is an eyepiece). By placing the heat ray cut filter 21 and the light-shielding plate 23 on a graphics (ECS-4011GX, etc.), the active energy ray 50 consisting only of direct light whose irradiation angle is controlled is taken out. Irradiate the coating layer 1 formed above.
The linear ultraviolet lamp usually has a value in the range of −80 to 80 °, preferably −50 to 50 with respect to the direction (0 °) perpendicular to the longitudinal direction of the process sheet 2 having the coating layer 1. It is installed so as to have a value in the range of °, particularly preferably in the range of -30 to 30 °.
At this time, as the irradiation angle of the irradiation light, as shown in FIG. 6B, the irradiation angle θ3 when the angle with respect to the normal of the surface of the coating layer 1 is 0 ° is usually −80 to 80 °. It is preferable to set the value within the range.
The reason for this is that when the irradiation angle θ3 becomes 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 becomes difficult to form a sufficient louver structure. Because there is.
The irradiation angle θ3 preferably has a width (irradiation angle width) θ3 ′ of 1 to 80 °.
This is because when the irradiation angle width θ3 ′ is less than 1 °, the interval between the louver structures becomes too narrow, and it may be difficult to obtain an anisotropic light diffusion film. On the other hand, when the irradiation angle width θ3 ′ exceeds 80 °, the irradiation light is excessively dispersed and it may be difficult to form a louver structure.
Therefore, the irradiation angle width θ3 ′ of the irradiation angle θ3 is more preferably set to a value within the range of 2 to 45 °, and further preferably set to a value within the range of 5 to 20 °.
By using a linear light source, it is substantially parallel light when viewed from the axial direction of the linear light source, and non-parallel when viewed from a direction perpendicular to the axial direction of the linear light source. Irradiation light can be irradiated.

Moreover, as irradiation light, an ultraviolet-ray, an electron beam, etc. are mentioned, It is preferable to use an ultraviolet-ray.
This is because, in the case of an electron beam, the polymerization rate is very fast, so that the components (A) and (B) cannot be sufficiently phase-separated during the polymerization process, making it difficult to form a louver structure. Because. On the other hand, when compared with visible light or the like, since ultraviolet rays are richer in variations of ultraviolet curable resins that can be cured by irradiation and usable photoinitiators, components (A) and (B) This is because the range of selection can be expanded.
In addition, the ultraviolet irradiation conditions are such that the peak illuminance at the time of irradiation is a value within the range of 0.1 to 50 mW / cm ² and that the applied light amount is sufficient to cure the coating layer. Is preferred.
In addition, it is also preferable to irradiate with ultraviolet rays in multiple stages so that the integrated light amount can sufficiently cure the coating layer.
Moreover, it is preferable that the coating layer formed on the process sheet is moved at a speed of 0.1 to 10 m / min to pass the ultraviolet irradiation part by the ultraviolet irradiation apparatus.
The reason for this is that mass productivity may be excessively reduced when the speed is less than 0.1 m / min. On the other hand, when the speed exceeds 10 m / min, the coating layer is hardened, in other words, faster than the formation of the louver structure, and the incident angle of ultraviolet rays to the coating layer changes greatly along the film thickness direction. This is because the louver structure may be insufficiently formed.
Therefore, it is more preferable that the coating layer formed on the process sheet is moved at a speed within the range of 0.2 to 5 m / min, and the ultraviolet irradiation portion by the ultraviolet irradiation device is allowed to pass, More preferably, it is passed at a speed within the range of 3 m / min.
In addition, as shown in FIG.5 (c), the anisotropic light-diffusion film 10 after a photocuring process will be in the state which can be finally used by peeling the process sheet | seat 2. FIG.

2. Film thickness The thickness of the anisotropic light diffusion film is preferably set to a value in the range of 100 to 500 μm.
The reason for this is that the thickness of the anisotropic light diffusing film is set to a value within this range, so that the anisotropic light diffusing film is not laminated and applied to a reflective liquid crystal display device or the like as a single layer. This is because it is possible to efficiently use external light as a light source and to prevent the occurrence of problems such as a decrease in the sharpness of the displayed image and the appearance of iris colors.
That is, when the film thickness is less than 100 μm, the length of the louver structure in the film thickness direction formed in the film becomes excessively short, and the incident light that goes straight through the louver structure increases, which is sufficient. This is because it may be difficult to obtain a large incident angle dependency. On the other hand, when the film thickness exceeds 500 μm, the irradiation light is irradiated for a long time, so that the productivity is excessively reduced or the irradiation light is diffused by the louver structure formed in the initial stage. This is because it may be difficult to form a desired louver structure.
Therefore, the thickness of the anisotropic light diffusion film is more preferably set to a value within the range of 130 to 300 μm, and further preferably set to a value within the range of 150 to 250 μm.

3. Louver structure Moreover, as shown to Fig.7 (a)-(c), the anisotropic light-diffusion film 10 of this invention is the plate-shaped area | region 12 derived from (A) component, and the plate shape derived from (B) component. Although the louver structure which the area | region 14 extended alternately is provided, each width (S1, S2) of the plate-shaped area | region 12 derived from the (A) component and the plate-shaped area | region 14 derived from the (B) component is set to 0. A value within the range of 1 to 15 μm is preferable.
This is because when the width is less than 0.1 μm, it may be difficult to exhibit light diffusibility regardless of the incident angle of incident light. On the other hand, when the width exceeds 15 μm, it may be difficult to show light diffusibility regardless of the incident angle of incident light.
Therefore, each width (S1, S2) of the plate-like region 12 derived from the component (A) and the plate-like region 14 derived from the component (B) is set to a value within the range of 0.5 to 10 μm. More preferably, the value is more preferably in the range of 1 to 5 μm.

Moreover, it is preferable that the initial inclination angle θ4 in the louver structure is set to a value within the range of 0 to 80 °.
This is because it may be difficult to show the incident angle dependency when the initial inclination angle θ4 exceeds 80 °.
Therefore, the initial inclination angle θ4 in the louver structure is more preferably set to a value within the range of 0 to 50 °.
The initial inclination angle θ4 refers to the angle on the narrow side of the angles formed by the normal of the film surface on the incident light irradiation side and the louver as shown in FIG.
More specifically, the initial inclination angle θ4 is when the angle with respect to the normal of the film surface measured when the film is cut in a plane perpendicular to the louver structure extending along the film surface direction is 0 ° The inclination angle (°) of the plate-like region.
Further, as shown in FIG. 7, the inclination angle when the plate-like region is inclined to the right is used as a reference, and the inclination angle when the plate-like region is inclined to the left is expressed as minus.
Furthermore, as shown in FIG. 7A, the anisotropic light diffusion film 10 of the present embodiment may have a louver structure (length L1 in the film thickness direction) formed in the entire film thickness direction. ), At least one of the upper end portion and the lower end portion of the film 10 may have a louver structure-unformed portion (thickness direction length L2).

In addition, the length L1 in the film thickness direction in the louver structure is preferably a value within the range of 50 to 500 μm, although it depends on the film thickness of the anisotropic light diffusion film 10.
This is because when the length is less than 50 μm, incident light that travels straight through the louver structure increases, and it may be difficult to obtain sufficient incident angle dependency. On the other hand, when the length exceeds 500 μm, a loss such as light reflection or absorption may occur while passing through the louver structure.
Therefore, the length in the film thickness direction L1 in the louver structure is more preferably set to a value within the range of 130 to 300 μm, and further preferably set to a value within the range of 150 to 250 μm.
In addition, the width L2 of the upper and lower end portions where the louver structure is not formed is preferably a value within the range of 0 to 200 μm, and preferably within the range of 0 to 100 μm, although it depends on the film thickness of the anisotropic light diffusion film 10. It is preferable that it is the value of this, and it is further more preferable that it is a value within the range of 0-50 micrometers.
Moreover, as shown in FIG.7 (c), it is also preferable that the louver structure is bent.
This is because the louver structure is bent, so that the incident light that goes straight through the louver structure can be reduced and the uniformity of light diffusion can be improved.
In addition, such a bent louver structure can be obtained by irradiating light while changing the irradiation angle of irradiation light when performing photocuring of the composition for anisotropic light diffusion film. It also greatly depends on the type of component and component (B).

Moreover, it is preferable to make the refractive index of the plate-shaped area | region derived from the (A) component in a louver structure into the value within the range of 1.5-1.7.
The reason for this is that when the refractive index of the plate-like region derived from the component (A) is less than 1.5, the difference from the refractive index of the plate-like region derived from the component (B) is too small, This is because it may be difficult to obtain such anisotropy. On the other hand, if the refractive index of the plate-like region derived from the component (A) is a value exceeding 1.7, the compatibility with the component (B) may be excessively lowered.
Therefore, it is more preferable to set the refractive index of the plate-like region derived from the component (A) in the louver structure to a value in the range of 1.52 to 1.65, and a value in the range of 1.55 to 1.6. More preferably.
The refractive index can be measured according to JIS K0062, for example.

Moreover, it is preferable to make the refractive index of the plate-shaped area | region derived from the (B) component in a louver structure into the value within the range of 1.4-1.5.
This is because when the refractive index of the plate-like region derived from the component (B) has a value of less than 1.4, the rigidity of the obtained anisotropic light diffusion film may be lowered. On the other hand, when the refractive index of the plate-like region derived from the component (B) is a value exceeding 1.5, the difference from the refractive index of the plate-like region derived from the component (A) becomes too small, and a desired value is obtained. This is because it may be difficult to obtain anisotropy.
Accordingly, the refractive index of the plate-like region derived from the component (B) in the louver structure is more preferably set to a value within the range of 1.42 to 1.48, and the value within the range of 1.44 to 1.46. More preferably.
The refractive index can be measured according to JIS K0062, for example.

In the anisotropic light diffusing film of the present embodiment, the difference between the refractive index of the plate-like region derived from the component (A) in the louver structure and the refractive index of the plate-like region derived from the component (B) is 0. A value of .01 or more is preferable.
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 in the louver structure is narrowed, so that the opening angle of diffused light may be excessively narrowed. Because.
Therefore, the difference between the refractive index of the plate-like region derived from the component (A) in the louver structure and the refractive index of the plate-like region derived from the component (B) is more preferably 0.03 or more. .
In addition, although the difference of refractive index is so preferable that it is large, about 0.1 is considered to be an upper limit.

4). Applications Further, as shown in FIG. 8, the anisotropic light diffusion film of the present invention is preferably used for a reflective liquid crystal display device 100.
The reason for this is that the anisotropic light diffusion film of the present invention efficiently diffuses external light so that it can be efficiently transmitted into the liquid crystal display device and used as a light source. It is because it can do.
Therefore, the anisotropic light diffusing film of the present invention is disposed on the upper surface or the lower surface of the liquid crystal cell 110 composed of the glass plates (104, 108) and the liquid crystal 106, the specular reflection plate 107, etc. The light diffusing plate 103 is preferably used.

  Hereinafter, the present invention will be described in more detail with reference to examples.

[Example 1]
1. (B) Synthesis of component In a container, 2 mol of isophorone diisocyanate (IPDI) as component (a) with respect to 1 mol of polypropylene glycol (PPG) having a weight average molecular weight of 9,200 as component (b), And after accommodating 2 mol of 2-hydroxyethyl methacrylate (HEMA) as (c) component, it superposed | polymerized in accordance with the conventional method, and obtained the polyether urethane methacrylate of the weight average molecular weight 9,900.

In addition, the weight average molecular weight of PPG 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.

2. Preparation of composition for anisotropic light diffusing film Next, 100 parts by weight of polyether urethane methacrylate having a weight average molecular weight of 9,900 as the component (B) thus obtained is represented by the following formula (3) as the component (A). O-phenylphenoxyethyl acrylate having a weight average molecular weight of 268 (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester A-LEN-10) and 2-hydroxy-2-methylpropiophenone as component (C) After adding 10 parts by weight, the mixture was heated and mixed at 80 ° C. to obtain a composition for anisotropic light diffusion film.
Here, the refractive index of the component (A) and the component (B) is determined according to JIS K0062 by an Abbe refractometer (manufactured by Atago Co., Ltd., product name: Abbe refractometer DR-M2, light source: Na light source, wavelength: 589 nm). Measured accordingly.
Hereinafter, the compound represented by the formula (3) may be referred to as biphenyl-1.

3. Application of composition for anisotropic light diffusing film Next, the obtained composition for anisotropic light diffusing film was applied to a transparent polyethylene terephthalate film (hereinafter referred to as PET) as a process sheet using an applicator, and a film A coating layer having a thickness of 250 μm was obtained.

4). Photo-curing of coating layer Next, an ultraviolet irradiation device (ECS-4011GX, manufactured by Eye Graphics Co., Ltd.) in which a condensing cold mirror was attached to a linear high-pressure mercury lamp as shown in FIG. 6 was prepared.
Next, a light shielding plate is installed on the heat ray cut filter frame, and the ultraviolet rays applied to the surface of the coating layer are normal to the laminate composed of the coating layer and PET when viewed from the longitudinal direction of the linear ultraviolet lamp. Was set so that the irradiation angle of the direct ultraviolet rays from the lamp (θ3 in FIG. 6B) was in the range of 0 to 10 ° (irradiation angle width θ3 ′ = 10 °).
At this time, the height of the lamp from the coating layer was set to 290 mm, and the peak illuminance was set to 9 mW / cm ² .
In addition, in order to prevent the reflected light from the light shielding plate etc. from becoming stray light inside the irradiator and affecting the photocuring of the coating layer, a light shielding plate is also provided in the vicinity of the conveyor, and only ultraviolet rays emitted directly from the lamp are It set so that it might irradiate with respect to a coating layer.
Next, ultraviolet rays were irradiated while moving the coating layer in the right direction in FIG. 6 at a speed of 0.2 m / min by a conveyor to obtain an anisotropic light diffusing film having a film thickness of 250 μm.
In addition, the film thickness of the anisotropic light-diffusion film was measured using the constant pressure thickness measuring device (Takara Seisakusho Co., Ltd. make, TECLOCK PG-02J).
Moreover, when the cross section of the anisotropic light diffusion film was observed with an optical digital microscope (manufactured by Keyence Corporation), the inclination angle (initial inclination angle) of the louver structure on the film surface side where the irradiated light first hits was 6.5 °. In addition, the length of the louver structure in the film thickness direction (L1 in FIG. 7B) was 200 μm.

5. Evaluation (1) Evaluation of incidence angle dependency by measurement Using a gonometric colorimeter (manufactured by Suga Test Instruments Co., Ltd., VC-2) with respect to the film from below the obtained anisotropic light diffusion film. , Light was incident (C light source, viewing angle 2 °).
Subsequently, the brightness (%) of the diffused light diffused by the anisotropic light diffusing film was measured every 5 °.
Next, an angle range between the measurement points at both ends where the difference in brightness between adjacent measurement points was less than 10% was defined as a diffusion region, and an angular width of the angle region was defined as an opening angle (°) of diffused light.
Further, the diffusion region when the incident angle of incident light is 0 °, the average value of the lightness in the diffusion region, and the absolute value of the difference between the average value and the maximum value and the minimum value of the lightness in the diffusion region, Each is shown in Table 1.

In addition, by continuously changing the incident angle of the incident light, the opening angle of the diffused light at each incident angle is measured, and the range of the incident angle where the opening angle of the diffused light is 10 ° or more is A diffuse incident angle region was used. The obtained results are shown in Table 1.
In addition, it means that the incident light which entered with the incident angle at that time was diffused more effectively by the anisotropic light-diffusion film, so that the value of the opening angle of diffused light is large.
Conversely, the smaller the opening angle of the diffused light, the light incident at the incident angle at that time is transmitted through the anisotropic light diffusing film as it is and does not diffuse.
For Examples 1, 3 and 4, the horizontal axis represents the incident angle (°) with respect to the anisotropic light diffusing film on the horizontal axis, and the characteristic curve having the diffused light opening angle (°) on the vertical axis, As shown in FIG.
For example, as in the case of Example 1, when there is no measurement plot on the characteristic curve when the opening angle of the diffused light is 10 °, the characteristic curve (extrapolated line) and the diffused light opening The value of the light diffusion incident angle region was obtained from the value of the incident angle (°) at the intersection with the straight line of angle = 10 °.

(2) Evaluation of visual anisotropy (2) -1 Light diffusibility Five panelists visually observed the opposite side through the film from the front (diffusion direction) of the anisotropic light diffusion film. The appearance in each case was evaluated according to the following criteria, and the visual light diffusibility was evaluated. The obtained results are shown in Table 1.
A: Five out of five people judged to have sufficient opacity.
B: 3 to 4 out of 5 people judged to have sufficient opacity.
C: Three to five out of five people judged that the opacity itself was present, although the opacity was poor.
D: 3 to 4 out of 5 people judged not to have opacity.
E: Five out of five people judged not to be opaque.

(2) -2 Light Transmittance When five panelists visually observe the opposite side of the anisotropic light diffusing film from the oblique 45 ° direction (transmission direction), the following is shown. Evaluation was made according to the criteria, and the light transmission was evaluated visually. The obtained results are shown in Table 1.
A: 5 out of 5 people judged that it was completely transparent and uncolored.
○: 3 to 4 out of 5 people judged that it was completely transparent and uncolored.
(Triangle | delta): It was judged that 3-4 persons are exhibiting cloudiness or yellow.
X: It was judged that 5 out of 5 people had white turbidity or yellow.

[Example 2]
In Example 2, the weight average molecular weight of the polyether urethane methacrylate as the component (B) was changed to 6,100 by changing the component (b) to PPG having a smaller weight average molecular weight than that in Example 1. Otherwise, an anisotropic light diffusing film composition was prepared in the same manner as in Example 1, and an anisotropic light diffusing film was produced and evaluated. The obtained results are shown in Table 1.

[Example 3]
In Example 3, the weight average molecular weight of the polyether urethane methacrylate as the component (B) was changed to 14,500 by changing the component (b) to PPG having a larger weight average molecular weight than that in Example 1. Otherwise, an anisotropic light diffusing film composition was prepared in the same manner as in Example 1, and an anisotropic light diffusing film was produced and evaluated. The obtained results are shown in Table 1.

[Example 4]
In Example 4, the addition amount of the component (A) is 60 parts by weight with respect to 100 parts by weight of the component (B), and the addition amount of the component (C) is 20 parts by weight. Similarly, an anisotropic light diffusion film composition was prepared, and an anisotropic light diffusion film was produced and evaluated. The obtained results are shown in Table 1.

[Example 5]
In Example 5, an anisotropic light diffusing film composition was prepared in the same manner as in Example 1 except that the amount of component (A) added was 150 parts by weight with respect to 100 parts by weight of component (B). An anisotropic light diffusion film was manufactured and evaluated. The obtained results are shown in Table 1.

[Example 6]
In Example 6, when synthesizing component (B), 2-hydroxyethyl acrylate (HEA) was used as component (c), and the amount of component (C) added was 100 parts by weight of component (B). An anisotropic light diffusing film composition was prepared in the same manner as in Example 1 except that the amount was 20 parts by weight, and an anisotropic light diffusing film was produced and evaluated. The obtained results are shown in Table 1.

[Example 7]
In Example 7, an anisotropic light diffusing film composition was prepared in the same manner as in Example 6 except that the thickness of the anisotropic light diffusing film was 500 μm, and an anisotropic light diffusing film was produced and evaluated. The obtained results are shown in Table 1.

[Example 8]
In Example 8, the addition amount of the component (C) was changed to 4 parts by weight with respect to 100 parts by weight of the component (B), and the film thickness of the anisotropic light diffusion film was changed to 500 μm. An anisotropic light diffusing film composition was prepared and an anisotropic light diffusing film was produced and evaluated. The obtained results are shown in Table 1.

[Example 9]
In Example 9, the amount of component (C) added was changed to 2 parts by weight with respect to 100 parts by weight of component (B), and the film thickness of the anisotropic light diffusing film was changed to 500 μm. An anisotropic light diffusing film composition was prepared and an anisotropic light diffusing film was produced and evaluated. The obtained results are shown in Table 1.

[Example 10]
In Example 10, an anisotropic light diffusing film composition was prepared in the same manner as in Example 1 except that (A) component was o-phenylphenoxyethoxyethyl acrylate having a weight average molecular weight of 312 represented by the following formula (4). An anisotropic light diffusion film was prepared and evaluated. The obtained results are shown in Table 1.
Hereinafter, the compound represented by the formula (4) may be referred to as biphenyl-2.

[Example 11]
In Example 11, an anisotropic light diffusing film composition was prepared in the same manner as in Example 1 except that the component (A) was a 50:50 (weight ratio) mixture of biphenyl 1 and biphenyl 2, and anisotropic light Diffusion films were manufactured and evaluated. The obtained results are shown in Table 1.

[Comparative Example 1]
In Comparative Example 1, component (B) was changed to 2-acryloyloxyethyl succinate (weight average molecular weight: 216) (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester A-SA), and the amount of component (C) added was changed. The composition for an anisotropic light diffusing film was prepared in the same manner as in Example 1, except that the amount of the component (B) was 20 parts by weight with respect to 100 parts by weight of the component, and the thickness of the anisotropic light diffusing film was 500 μm. An anisotropic light diffusing film was manufactured and evaluated. The obtained results are shown in Table 1.

[Comparative Example 2]
In Comparative Example 2, when synthesizing polyether urethane methacrylate as component (B), 2-hydroxyethyl acrylate (HEA) was used as component (c) and the weight average molecular weight of polyether urethane methacrylate was changed to 740. Furthermore, an anisotropic light diffusing film was prepared and evaluated in the same manner as in Example 1 except that the anisotropic light diffusing film had a thickness of 500 μm. The obtained results are shown in Table 1.

[Comparative Example 3]
In Comparative Example 3, the component (A) was changed to ethoxylated bisphenol A type diacrylate represented by the following formula (5) (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester A-BPE-4). An anisotropic light diffusion film was prepared and evaluated in the same manner as in Example 1 except that the amount added was 4 parts by weight with respect to 100 parts by weight of component (B). . The obtained results are shown in Table 1.

[Comparative Example 4]
In Comparative Example 4, the component (A) was 9,9′-bis [4- (2-acryloyloxyethoxy) phenyl] fluorene represented by the following formula (6) (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester A- The composition for anisotropic light diffusing film was prepared in the same manner as in Example 1 except that the amount of component (C) was changed to 4 parts by weight with respect to 100 parts by weight of component (B) instead of BPEF). An anisotropic light diffusing film was manufactured and evaluated. The obtained results are shown in Table 1.

As described above in detail, according to the present invention, a biphenyl ring-containing compound having a specific structure and a polymerizable compound having a weight average molecular weight within a predetermined range are blended at a predetermined ratio. Thus, an anisotropic light diffusion film having good incident angle dependency can be obtained.
More specifically, it has become possible to obtain an anisotropic light diffusion film having a good incident angle dependency in light transmission and diffusion and a wide light diffusion incident angle region.
Therefore, the anisotropic light diffusion film composition of the present invention can be applied to a viewing angle control film, a viewing angle widening film, and a projection screen, in addition to a light control film in a reflective liquid crystal display device, It is expected to contribute significantly to the improvement of quality.

1: coating layer, 2: process sheet, 10: anisotropic light diffusion film, 12: plate-like region having a relatively high refractive index derived from component (A), 14: relatively refractive index derived from component (B) Low plate-like region, 20: ultraviolet irradiation device, 21: heat ray cut filter, 22: cold mirror, 23: light shielding plate, 25: linear ultraviolet lamp, 50 (52, 54, 56): incident light (active energy ray) ), 100: reflection type liquid crystal display device, 101: polarizing plate, 102: retardation plate, 103: light diffusion plate, 104: glass plate, 105: color filter, 106: liquid crystal, 107: specular reflection plate, 108: glass Plate, 110: Liquid crystal cell

Claims (5)

(A) The biphenyl compound which makes the refractive index represented by the following general formula (1) as a component the value within the range of 1.55-1.6, and the weight average molecular weight as (B) component are 5,000- Ri value der in the range of 15,000, an anisotropic light-diffusing film composition containing urethane (meth) acrylate, a to the refractive index within a range of 1.45 to 1.49,
The urethane (meth) acrylate as the component (B) is derived from the following components (a) to (c) as components, and the weight average molecular weight of the component (b) is 4,300 to 14,300. And within the range of
The composition for an anisotropic light diffusing film, wherein the content of the component (A) is set to a value in the range of 25 to 400 parts by weight with respect to 100 parts by weight of the component (B).
(A) Alicyclic diisocyanate
(B) Polyalkylene glycol
(C) Hydroxyalkyl (meth) acrylate
(In General Formula (1), R ^{1 to} R ¹⁰ are each independent, and any one of R ^{2 to} R ⁹ is a substituent represented by the following General Formula (2), and the rest is hydrogen. It is a substituent of any one of an atom, a hydroxyl group, a carboxyl group, an alkyl group, an alkoxy group, a halogenated alkyl group, a hydroxyalkyl group, a carboxyalkyl group and a halogen atom.)
(In General Formula (2), R ¹¹ is a hydrogen atom or a methyl group, carbon number n is an integer of 1 to 4, and repetition number m is an integer of 1 to 10.)   2. The composition for anisotropic light diffusing film according to claim 1, wherein the weight average molecular weight of the component (A) is set to a value in the range of 200 to 2,500. (C) As a component, it contains a photopolymerization initiator, and its content is within the range of 0.2 to 20% by weight with respect to the total amount (100% by weight) of the component (A) and the component (B). anisotropic light-diffusing film composition according to claim 1 or 2, characterized in that the values. An anisotropic light diffusion film that is a cured product of the composition for anisotropic light diffusion film,
The anisotropic light-diffusing film composition comprises a biphenyl compound having a refractive index represented by the following general formula (1) as a component (A) within a range of 1.55 to 1.6, and a component (B) the weight average molecular weight as the Ri value der within the range of 5,000 to 15,000, seen containing urethane (meth) acrylate, a to the refractive index within a range of 1.45 to 1.49,
The urethane (meth) acrylate as the component (B) is derived from the following components (a) to (c) as components, and the weight average molecular weight of the component (b) is 4,300 to 14,300. And within the range of
An anisotropic light diffusing film, wherein the content of the component (A) is set to a value in the range of 25 to 400 parts by weight with respect to 100 parts by weight of the component (B).
(A) Alicyclic diisocyanate
(B) Polyalkylene glycol
(C) Hydroxyalkyl (meth) acrylate
(In General Formula (1), R ^{1 to} R ¹⁰ are each independent, and any one of R ^{2 to} R ⁹ is a substituent represented by the following General Formula (2), and the rest is hydrogen. It is a substituent of any one of an atom, a hydroxyl group, a carboxyl group, an alkyl group, an alkoxy group, a halogenated alkyl group, a hydroxyalkyl group, a carboxyalkyl group and a halogen atom.)
(In General Formula (2), R ¹¹ is a hydrogen atom or a methyl group, carbon number n is an integer of 1 to 4, and repetition number m is an integer of 1 to 10.) The anisotropic light diffusion film according to claim 4 , wherein the film thickness is set to a value in the range of 100 to 500 μm.