TWI577728B - Composition for anisotropic light diffusion film and anisotropic light diffusion film - Google Patents

Description

Composition for anisotropic light-diffusing film and anisotropic light-diffusing film

The present invention relates to a composition for an anisotropic light-diffusing film and an anisotropic light-diffusing film. In particular, it relates to a composition for anisotropic light-diffusing film which can obtain an anisotropic light-diffusing film having a good incident angle dependency in light transmission and diffusion and having a wide light diffusion incident angle region, and photocuring the same An anisotropic light diffusing film.

Conventionally, in a liquid crystal display device, light emitted from a light source (internal light source) provided inside the device can be used to recognize a given image.

However, in recent years, with the spread of mobile phones, car televisions, and the like, the chance of viewing a liquid crystal display screen outdoors has increased, and the accompanying light intensity from the internal light source is inconsistent with external light and it is difficult to recognize a given screen. problem.

In addition, in mobile applications such as mobile phones, since the power consumption of the internal light source of the liquid crystal display device accounts for a large proportion of the total power consumption, when the internal light source is used in a large amount, the battery life of the battery becomes short. problem.

Therefore, in order to solve such problems, a reflective liquid crystal display device using external light as a part of a light source has been developed.

In the case of the reflective liquid crystal display device, since the external light is partially used as a light source, the stronger the external light, the more vivid the image can be recognized, and the power consumption of the internal light source can be effectively suppressed. .

Further, in such a reflective liquid crystal display device, in order to efficiently transmit external light into the inside of the liquid crystal display device, and to effectively utilize the external light as a part of the light source, it has been proposed to efficiently perform light diffusion. A scheme of an anisotropic light-diffusing film (for example, Patent Document 1).

More specifically, in Patent Document 1, as shown in FIGS. 10(a) to (b), a liquid crystal cell having a liquid crystal layer 1105 interposed between the upper substrate 1103 and the lower substrate 1107 has been disclosed. A light reflecting plate 1110 provided on the lower substrate 1107 side and a liquid crystal device 1112 provided in a light control plate (anisotropic light diffusing film) 1108 provided between the liquid crystal layer 1105 and the light reflecting plate 1110.

Further, a light control panel 1108 for selectively scattering light incident at a given angle and transmitting light incident at an angle other than a given angle is provided, the light control panel 1108 being disposed in the liquid crystal cell in the following manner That is, the scattering axis direction 1121 obtained by selectively scattering the direction of the light incident at a given angle onto the surface of the light control plate 1108 is substantially in the direction of the 6 o'clock direction in the plane of the liquid crystal cell.

In addition, various forms are known as the anisotropic light-diffusing film used in the reflective liquid crystal display device. However, in particular, an anisotropic light-diffusing film having the following louver structure can be widely used (for example, Patent Document 2) ~4).

In other words, by arranging the elongated plate-shaped high refractive index region and the elongated plate-shaped low refractive index region in parallel in the film surface direction, it is possible to control the light direction and adjust the light dispersibility in the film.

That is, Patent Document 2 discloses a light control film which irradiates ultraviolet rays in a specific direction to a film-like composition containing a plurality of compounds having a polymerizable carbon-carbon double bond to cure the composition. It is preferable to selectively scatter only incident light of a specific angular range (anisotropic light-diffusion film), characterized in that at least one compound contained in the composition has a plurality of aromatic rings and one polymerizable property in the molecule. A compound of carbon-carbon double bonds.

Further, Patent Document 3 discloses a photocurable composition comprising a fluorene-based compound (A) having a polymerizable carbon-carbon double bond in a molecule, a refractive index, and a lanthanide system. A cationically polymerizable compound (B) having a different compound (A) and a cationic photopolymerization initiator (C) are disclosed, and a light control film obtained by curing the same is disclosed.

Further, Patent Document 4 discloses a composition for an anisotropic light-diffusing film comprising at least (A) a bisphenol A type epoxy resin or a brominated bisphenol A type epoxy represented by the general formula (5). Resin, (B) a radically polymerizable compound containing at least one ethylenically unsaturated bond in a structural unit, (D) a photopolymerization initiator which generates a radical seed by chemical radiation, and (E) utilization A thermal polymerization initiator which thermally generates cationic seeds, and an anisotropic light-diffusing film produced by the same has been disclosed. More specifically, a composition for anisotropic light-diffusing film has been disclosed, characterized in that (B) a refractive index ratio of a compound having a radical polymerizable property at a normal temperature (A) bisphenol A type epoxy resin Or a brominated bisphenol A type epoxy resin and (C) a compound having at least one cationically polymerizable group in a molecule are low, and an anisotropic light-diffusing film produced by the same is disclosed.

[Chemical Formula 1]

In the formula (5), R represents a hydrogen atom or a bromine atom, and the number of repetitions p represents a natural number.

[Prior Art]

Patent literature

Patent Document 1 Japanese Patent No. 3480260 (Application Patent Area)

Patent Document 2 Japanese Laid-Open Patent Publication No. 2006-350290 (Application No.)

Patent Document 3 Japanese Laid-Open Patent Publication No. 2008-239757 (Application No.)

Patent Document 4 Japanese Patent No. 3,829,601 (Application Patent Application)

However, the anisotropic light-diffusing film disclosed in Patent Documents 1 to 4 not only lacks the incident angle dependency in light transmission and diffusion, but also has a narrow light diffusion incident angle region, and therefore, in a reflective liquid crystal display device, It is difficult to effectively use external light.

In addition, although an attempt has been made to laminate a plurality of anisotropic light-diffusing films to widen the width of the light-diffusing incident angle region, the sharpness of the image is lowered or the rainbow color (corrugated image) appears, and further, it is economically apparent. Unfavorable problems.

In addition, the practice of laminating a plurality of anisotropic light-diffusing films also has a cost problem.

Therefore, the present inventors conducted intensive efforts in view of the above-described circumstances, and as a result, found that it is composed of a (meth) acrylate containing a plurality of aromatic rings, and is composed of a given constituent component and has a given The urethane (meth) acrylate having a weight average molecular weight is photocured by mixing in a given ratio to obtain an anisotropic light-diffusing film having a good incident angle dependency, thereby completing the present invention.

That is, an object of the present invention is to provide an anisotropic light-diffusing film combination which can obtain an anisotropic light-diffusing film having a good incident angle dependency in light transmission and diffusion and having a wide light diffusion incident angle region. And an anisotropic light-diffusing film obtained by photocuring it.

According to the present invention, there is provided a composition for an anisotropic light-diffusing film comprising (meth)acrylate containing a plurality of aromatic rings as the component (A) and having a weight average molecular weight of (3000) as a component (B) A urethane (meth) acrylate having a value in the range of ～20000, wherein the urethane (meth) acrylate as the component (B) is derived from the following as a constituent component (a) )~(c) component, and a compound consisting of (a) component: (b) component: (c) component = 1 to 5: 1:1 to 5 in terms of molar ratio, and relative to (B) The above problem can be solved by setting the content of the component (A) to a value in the range of 25 to 400 parts by weight based on 100 parts by weight of the component.

(a) a compound having 2 isocyanate groups via an aliphatic ring; (b) a polyolefin diol; (c) a hydroxyalkyl (meth) acrylate.

In other words, it is presumed that a (meth) acrylate containing a plurality of aromatic rings as the component (A) and a component constituting component (B) are formed by a given constituent component, and have a given weight average molecular weight. The urethane (meth) acrylates are respectively blended in a given range, so that polymerization of the respective components is possible A given difference in speed (for example, photoradical polymerization rate), suppressing uniform copolymerization between the two components, that is, reducing the compatibility of the component (A) and the component (B) to a given range, thereby reducing Copolymerization between the two components.

When the photocuring is carried out, the cured product of the component (A) and the cured product of the component (B) are alternately extended, and it is possible to effectively form a high refractive index in which the elongated plate shape is alternately arranged in parallel in the film surface direction. The louver structure is formed by a region and an elongated plate-shaped low refractive index region.

Therefore, in the case of the composition for anisotropic light-diffusing film of the present invention, an anisotropic light-diffusing film having a good incident angle dependency and a wide light-diffusing incident angle region in light transmission and diffusion can be obtained. .

In the present invention, the "film surface direction" means the x-y plane direction when the film thickness direction is the z-axis.

In the present invention, the term "light-diffusing incident angle region" refers to an angular range of incident light corresponding to the emitted diffused light when the angle of incident light from the point light source is changed with respect to the anisotropic light-diffusing film. . Details of the light diffusion incident angle region will be described later.

In addition, the term "good incident angle dependency" means that the difference between the incident angle region (light diffusing incident angle region) with respect to the film in which the light of the incident light is diffused and the other incident angle region where no light diffusion occurs is possible. Clear control.

Further, the meaning of the "anisotropic" of the present invention will be described later.

In the composition for anisotropic light-diffusing film of the present invention, it is preferred to contain the component (A) as a monomer component and the component (B) as a component of the oligomer.

According to this configuration, it is possible to effectively suppress the fluctuation of the refractive index of each of the plate-like region derived from the component (A) and the plate-like region derived from the component (B) in the louver structure, thereby obtaining more efficiently An anisotropic light diffusing film of a given louver structure.

In the case of the composition for anisotropic light-diffusing film of the present invention, it is preferred that the component (c) which is a constituent component of the component (B) is a hydroxyalkyl methacrylate.

It is presumed that the polymerization rate of the component (B) can be further lowered as compared with the component (A), and the copolymerization property of the component (A) and the component (B) can be more effectively reduced, thereby obtaining a given amount more efficiently. An anisotropic light diffusing film of the louver structure.

Further, in the case of constituting the composition for anisotropic light-diffusing film of the present invention, it is preferred to set the refractive index of the component (B) to a value in the range of 1.4 to 1.5.

With such a configuration, it is possible to more easily adjust 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), thereby being more efficiently obtained. An anisotropic light diffusing film having a given louver structure.

Further, the refractive index of the component (B) mentioned herein means the refractive index of the component (B) before curing by light irradiation.

Further, in the case of constituting the composition for anisotropic light-diffusing film of the present invention, it is preferred that the component (A) contains a biphenyl ring as a plurality of aromatic rings.

According to this configuration, the polymerization rate of the component (A) can be accelerated, and the component (A) and the component (B) can be prevented from being copolymerized more effectively, and the anisotropic light-diffusing film having a given louver structure can be more effectively obtained.

Further, in the case of constituting the composition for anisotropic light-diffusing film of the present invention, the weight average molecular weight of the component (A) is preferably in the range of 200 to 2,500.

It is presumed that by such a configuration, the polymerization rate of the component (A) can be further accelerated, and the copolymerizability of the component (A) and the component (B) can be more effectively reduced, so that each of the given louver structures can be obtained more efficiently. Anisotropic light diffuses the film.

Further, in the case of constituting the composition for anisotropic light-diffusing film of the present invention, it is preferred to set the refractive index of the component (A) to a value in the range of 1.5 to 1.65.

With such a configuration, it is possible to more easily adjust 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), thereby being more efficiently obtained. An anisotropic light diffusing film having a given louver structure.

Further, the refractive index of the component (A) referred to herein means the refractive index of the component (A) before curing by light irradiation.

Further, in the case of constituting the composition for anisotropic light-diffusing film of the present invention, it is preferred to contain a photopolymerization initiator as the component (C) and to be a total amount (100) with respect to the components (A) and (B). The weight %) is a value in the range of 0.2 to 20% by weight.

According to this configuration, when the active energy ray is irradiated to the composition for anisotropic light-diffusing film, a predetermined louver structure can be efficiently formed.

Further, another aspect of the present invention is an anisotropic light-diffusing film which is obtained by irradiating a composition for anisotropic light-diffusing film with an active energy ray, wherein the composition for anisotropic light-diffusing film is included as (A) component a (meth) acrylate having a plurality of aromatic rings, and a urethane (meth) acrylate having a weight average molecular weight of (B) in a range of from 3,000 to 20,000, as the component (B) The urethane (meth) acrylate is derived from the following components (a) to (c) as constituent components, and (a) component: (b) component: (c) component in terms of molar ratio = 1 to 5: a compound having a ratio of 1:1 to 5, and the content of the component (A) is set to a value within a range of 25 to 400 parts by weight based on 100 parts by weight of the component (B).

(a) a compound having 2 isocyanate groups via an aliphatic ring; (b) a polyolefin diol; (c) a hydroxyalkyl (meth) acrylate.

In other words, in the case of the anisotropic light-diffusing film of the present invention, since the composition for anisotropic light-diffusing film is photocured, it can be formed in light transmission and diffusion. An anisotropic light-diffusing film having an incident angle dependency and a light diffusing incident angle region.

Further, in the case of constituting the anisotropic light-diffusing film of the present invention, it is preferred to set the film thickness to a value in the range of 100 to 500 μm.

According to this configuration, even when the anisotropic light-diffusing film is laminated and applied directly to a reflective liquid crystal display device or the like in a single layer state, external light can be effectively utilized as a light source, and display can be prevented. The sharpness of the image is reduced, or the problem of rainbow color appears.

1‧‧‧ coating layer

2‧‧‧Engineering

10‧‧‧ Anisotropic light diffusing film

12‧‧‧A plate-like region derived from the higher refractive index of component (A)

13‧‧‧ Louver structure

13’‧‧‧ interface

14‧‧‧A plate-like region derived from the lower refractive index of component (B)

20‧‧‧UV irradiation device

21‧‧‧Infrared cut filter

22‧‧‧Cold mirror

23‧‧‧ visor

25‧‧‧Linear UV lamp

50, 52, 54, 56‧‧‧ incident light (active energy ray)

52’, 54’, 56’‧‧‧ diffused light

100‧‧‧Reflective liquid crystal display device

101‧‧‧Polarizer

102‧‧‧ phase difference plate

103‧‧‧Light diffuser

104‧‧‧ glass plate

105‧‧‧Color filters

106‧‧‧LCD

107‧‧‧Mirror reflector

108‧‧‧ glass plate

110‧‧‧Liquid Crystal Unit

1103‧‧‧Upper substrate

1105‧‧‧Liquid layer

1107‧‧‧lower substrate

1108‧‧‧Light control panel

1110‧‧‧Light reflector

1112‧‧‧Liquid device

1121‧‧‧scattering axis direction

Θ1‧‧‧ incident angle

Θ2‧‧‧ opening angle

Θ3‧‧‧ illumination angle

Θ‧‧‧illumination angle width

Θ4‧‧‧ initial tilt angle

3’

B‧‧‧Conveyor movement direction

S1, S2‧‧‧ film thickness direction width

L1, L2‧‧‧ film thickness direction length

1(a) to 1(b) are diagrams for explaining the outline of the louver structure of the anisotropic light-diffusing film.

Fig. 2 is a view for explaining the incident angle dependency and anisotropy of the anisotropic light-diffusing film.

3(a) to 3(b) are other diagrams for explaining the incident angle dependency of the anisotropic light-diffusing film.

4(a) to 4(c) are diagrams for explaining the angles of incidence of the incident angle and the diffused light.

5(a) to 5(c) are schematic views for explaining a method of producing an anisotropic light-diffusing film.

6(a) to 6(b) are diagrams for explaining the photocuring step.

7(a) to 7(c) are views for explaining the form of the louver structure of the anisotropic light-diffusing film of the present invention.

Fig. 8 is a view for explaining an application example of the anisotropic light-diffusing film of the present invention in a reflective liquid crystal display device.

Fig. 9 is a view showing the relationship between the incident angles of the first, third, and fourth embodiments with respect to the anisotropic light-diffusing film and the opening angle of the diffused light.

10(a) to 10(b) are views for explaining a reflection type liquid crystal display device using a conventional anisotropic light-diffusing film.

[First Embodiment]

The first embodiment of the present invention is a composition for an anisotropic light-diffusing film comprising (meth)acrylate containing a plurality of aromatic rings as the component (A), and a weight average molecular weight as the component (B) A urethane (meth) acrylate having a value in the range of from 3,000 to 20,000, wherein the urethane (meth) acrylate as the component (B) is derived from the following constituents (a) to (c) and a compound consisting of (a) component: (b) component: (c) component = 1 to 5: 1:1 to 5 in terms of molar ratio, and relative The content of the component (A) is set to a value within a range of 25 to 400 parts by weight based on 100 parts by weight of the component (B).

(a) a compound having 2 isocyanate groups via an aliphatic ring; (b) a polyolefin diol; (c) a hydroxyalkyl (meth) acrylate.

Hereinafter, a first embodiment of the present invention will be specifically described with reference to the accompanying drawings.

1. The basic principle of anisotropic light diffusion film

The basic principle of an anisotropic light-diffusing film (hereinafter simply referred to as an anisotropic light-diffusion film) obtained by photocuring the composition for anisotropic light-diffusing film of the present invention will be described below with reference to the drawings.

First, in Fig. 1(a), a top view (top view) of the anisotropic light-diffusing film 10 is shown, and in Fig. 1(b), the anisotropic light-diffusing film 10 shown in Fig. 1(a) is along The broken line AA is cut in the vertical direction to show a cross-sectional view of the anisotropic light-diffusing film 10 when the cut surface is viewed from the direction of the arrow.

As shown in the plan view of Fig. 1(a), the anisotropic light-diffusing film 10 is provided with a strip-like region 12 having a relatively high refractive index derived from the component (A) in the film surface direction, and is derived from B) The louver structure 13 in which the linear plate-like regions 14 having relatively low refractive index components are alternately arranged in parallel.

Further, as shown in the cross-sectional view of Fig. 1(b), the plate-like region 12 of the high refractive index derived from the component (A) and the plate-like region 14 derived from the low refractive index of the component (B) have respective The thickness is maintained in a state of being alternately arranged in parallel in the vertical direction of the anisotropic light-diffusing film 10.

From this, it can be estimated that the incident light is diffused by the anisotropic light diffusion film 10 in the case where the incident angle is in the light diffusion incident angle region as shown in FIG. 2 .

That is, it can be presumed that, as shown in Fig. 1(b), the incident angle of the incident light with respect to the anisotropic light-diffusing film 10 and the interface 13' of the louver structure 13 are substantially parallel to a given range. The inner angle, that is, the angle in which the light diffuses into the incident angle region, causes the incident light 52, 54 to pass through the plate-like region 12 having a high refractive index in the louver structure along the film thickness direction while changing the direction. The direction of travel of the light on the light exit side is different.

As a result, it can be estimated that when the incident angle is within the light diffusion incident angle region, the incident light is diffused (52', 54') by the anisotropic light diffusion film 10.

Further, the light-diffusing incident angle region is an angular region determined by the refractive index difference, the tilt angle, and the like of the louver structure in the anisotropic light-diffusing film depending on the anisotropic light-diffusing film.

In addition, the change in the direction of the incident light in the plate-like region 12 having a high refractive index in the louver structure is not the case of the abrupt refractive index type in which the direction is changed linearly by the total reflection as shown in FIG. It is also possible to consider the case of a graded refractive index type in which a direction changes in a curved shape.

On the other hand, in the case where the incident angle with respect to the incident light of the anisotropic light-diffusion film 10 is out of the light-diffusing incident angle region, it can be estimated that the incident light 56 is not diffused by the anisotropic light-diffusing film 10, but Pass through (56') as it is.

According to the above principle, the anisotropic light-diffusing film 10 having the louver structure 13 can exhibit an incident angle dependency in light transmission and diffusion as shown in FIG. 2 .

Further, as shown in FIG. 2, when the incident angle of the incident light is in the light diffusion incident angle region, the anisotropic light-diffusing film having the louver structure can be roughly formed on the light-emitting surface side even when the incident angle is different. The same light spreads.

Therefore, it can be said that the anisotropic light-diffusing film having a louver structure also has a condensing effect of concentrating light at a given portion.

Further, the term "anisotropic" as used in the present invention means a property in which, for example, as in the case of the light 52', 54' which is subjected to diffusion, the light is diffused by the film, as in Fig. 2, it has spread. The degree of diffusion of the light in the plane parallel to the film (the broadened shape of the diffused light) varies with the direction in the same plane.

More specifically, in the case of the anisotropic light-diffusing film 10 of the present invention, mainly in the plane parallel to the film of the diffused outgoing light, and the louver structure extending in the in-plane direction along the film 10. The light is diffused in a direction perpendicular to the direction, and the broadened shape of the diffused light is approximately elliptical (52', 54').

Further, the relationship between the incident angle of the incident light with respect to the anisotropic light-diffusing film and the opening angle of the diffused light diffused by the anisotropic light-diffusing film will be described with reference to Fig. 3(a).

That is, in Fig. 3(a), the incident angle (°) of the incident light with respect to the anisotropic light-diffusing film is taken in the horizontal axis, and the diffusion is spread by the anisotropic light-diffusing film in the vertical axis. The characteristic curve of the opening angle (°) of the diffused light.

Further, as shown in FIGS. 4(a) to 4(c), the incident angle θ1 is an angle (°) when the angle perpendicular to the anisotropic light-diffusing film 10 is set to 0°.

More specifically, as described above, since the component of the incident light participating in the anisotropic light diffusion is mainly a component perpendicular to the direction of the louver structure extending in the film surface direction, the incident light referred to in the present invention is " In the case of the incident angle θ1", it means the incident angle of a component perpendicular to the direction of the louver structure extending in the film surface direction. In addition, at this time, the incident angle θ1 is an angle (°) when the angle of the normal to the incident side surface of the anisotropic light-diffusing film is 0°.

Further, the opening angle θ2 of the diffused light, as indicated by the literal surface, refers to the opening angle (°) of the diffused light.

Further, the larger the opening angle of the diffused light, the more the light incident at the incident angle at this time is effectively diffused by the anisotropic light-diffusing film.

On the other hand, the smaller the opening angle of the diffused light, the more the light incident at the incident angle at this time passes through the anisotropic light-diffusing film as it is, and is not pre-diffused.

A specific measurement method of the opening angle of the diffused light is described in the examples.

It can be understood from the characteristic curve that in the case of an anisotropic light-diffusing film, the degree of light transmission and diffusion varies greatly depending on the angle of incidence, and the light can be diffused into the incident angle region and the incident angle other than the incident angle. The area is clearly separated.

On the other hand, in the case of a film that does not have an incident angle dependency, as shown in FIG. 3(b), the change in the incident angle does not have a clear influence on the degree of light transmission and diffusion, and the light diffusion incidence cannot be determined. Angle area.

Further, an object of the present invention is to obtain an anisotropic light-diffusing film in which the difference between the light-diffusing incident angle region and the incident angle region other than that shown in Fig. 3(a) is relatively clear and the light-diffusing incident angle region is wide. And a composition for anisotropic light-diffusing film of the film.

2. (A) component: (meth) acrylate

(1) Category

The composition for anisotropic light-diffusing film of the present invention is characterized in that (A) component contains a (meth) acrylate containing a plurality of aromatic rings.

For this reason, it is presumed that by including a specific (meth) acrylate as the component (A), the polymerization rate of the component (A) is faster than the polymerization rate of the component (B), and between these components A given difference in the rate of polymerization is obtained, so that the copolymerizability of the two components can be effectively reduced.

As a result, when the light is cured, a so-called louver structure in which the plate-like region derived from the component (A) and the plate-like region derived from the component (B) are alternately extended can be effectively formed.

Further, it is presumed that by including a specific (meth) acrylate as the component (A), it has sufficient compatibility with the component (B) at the monomer stage, and a plurality of connected ones during the polymerization. The compatibility with the component (B) is lowered to a given range in the stage, so that the louver structure can be formed more efficiently.

Further, by including a specific (meth) acrylate as the component (A), it is possible to increase the refractive index of the plate-like region derived from the component (A) in the louver structure, and to form a plate with the component derived from (B). The difference in refractive index of the region is adjusted to a value above a given value.

Therefore, by including a specific (meth) acrylate as the component (A), it is possible to effectively obtain a louver structure having a plate-like region in which refractive indices are alternately extended in combination with the characteristics of the component (B) to be described later. An anisotropic light diffusing film.

Thus, an anisotropic light-diffusing film having a good incident angle dependency in light transmission and diffusion and having a wide light diffusion incident angle region can be obtained.

Further, the term "(meth)acrylate having a plurality of aromatic rings" means a compound having a plurality of aromatic rings in the esterified portion of the (meth) acrylate.

In addition, "(meth)acrylic acid" means both acrylic acid and methacrylic acid.

Further, examples of the (meth) acrylate containing a plurality of aromatic rings as the component (A) include biphenyl (meth)acrylate, naphthyl (meth)acrylate, and (meth)acrylic acid. Anthracene ester, benzylphenyl (meth)acrylate, biphenyloxyalkyl (meth)acrylate, naphthyloxy (meth)acrylate An alkyl ester, a mercaptooxyalkyl (meth)acrylate, a benzyl phenyloxyalkyl (meth)acrylate, or the like, or a halogen moiety, an alkyl group, an alkoxy group, or a halogenated moiety Substituted substances such as alkyl groups.

In addition, the (meth) acrylate containing a plurality of aromatic rings as the component (A) is preferably a compound containing a biphenyl ring, and particularly a biphenyl compound represented by the following formula (1).

In the formula (1), R ¹ to R ¹⁰ are each independently, and at least one of R ¹ to R ¹⁰ is a substituent represented by the following formula (2), and the remainder is a hydrogen atom, a hydroxyl group, a carboxyl group, an alkyl group, Any one of an alkoxy group, a halogenated alkyl group, a hydroxyalkyl group, a carboxyalkyl group, and a halogen atom.

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

The reason for this is that the polymerization rate of the component (A) is further accelerated by the polymerization rate of the component (B) by including the biphenyl compound having a specific structure as the component (A).

In addition, the compatibility with the component (B) can be more easily reduced to a given range, and the refractive index of the plate-like region derived from the component (A) in the louver structure can be improved, and it is easier to The difference in refractive index of the plate-like region derived from the component (B) is adjusted to a value equal to or higher than a given value.

Further, the monomer stage before curing by light is liquid, and even if a diluent solvent or the like is not used, it can be uniformly mixed with the urethane (meth) acrylate as the component (B).

Further, in the case where R ¹ to R ¹⁰ in the formula (1) include any one of an alkyl group, an alkoxy group, an alkyl halide group, a hydroxyalkyl group, and a carboxyalkyl group, it is preferred to use an alkyl moiety thereof. The carbon number is set to a value in the range of 1 to 4.

The reason is that when the carbon number is more than 4, the polymerization rate of the component (A) is lowered, or the refractive index of the plate-like region derived from the component (A) in the louver structure is too low. There is a case where it is difficult to efficiently form a given louver structure of an anisotropic light-diffusing film.

Therefore, in the case where R ¹ to R ¹⁰ in the formula (1) contain any one of an alkyl group, an alkoxy group, an alkyl halide group, a hydroxyalkyl group, and a carboxyalkyl group, it is preferred to use an alkyl moiety thereof. The carbon number is set to a value in the range of 1 to 3, and is preferably set to a value in the range of 1 to 2.

Further, it is preferably a halogenated alkyl group of R ¹ to R ¹⁰ or a substituent other than a halogen atom in the formula (1), that is, a substituent which does not contain a halogen.

The reason for this is that it is preferable to prevent the occurrence of dioxin and to protect the environment when the anisotropic light-diffusing film is incinerated or the like.

Further, in the conventional anisotropic light-diffusing film having a louver structure, when a given louver structure is obtained, halogen substitution is generally performed in the monomer component for the purpose of increasing the refractive index of the monomer component. .

In this case, the biphenyl compound represented by the formula (1) can be set to have a high refractive index even when halogen substitution is not performed.

Therefore, in the case of an anisotropic light-diffusing film obtained by photocuring the composition for anisotropic light-diffusing film of the present invention, a good incident angle dependency can be exhibited even when halogen is not contained.

Further, it is preferred that any one of R ² to R ⁹ in the formula (1) is a substituent represented by the formula (2).

The reason for this is that, by setting the position of the substituent represented by the formula (2) to a position other than R ¹ and R ¹⁰ , it is possible to effectively prevent the component (A) from being in the stage before photocuring. Orientation and crystallization.

In this way, at the stage of photocuring, fine agglomeration and phase separation of the components (A) and (B) can be achieved, and an anisotropic light-diffusing film having a given louver structure can be obtained more effectively. .

Further, based on the same viewpoint, in particular, any one of R ³ , R ⁵ , R ⁶ and R ⁸ in the formula (1) is a substituent represented by the formula (2).

In addition, it is generally preferable to set the number of repetitions m in the substituent represented by the formula (2) to an integer of 1 to 10.

The reason is that when the number of repetitions m is more than 10, the oxyalkylene chain linking the polymerization site and the biphenyl ring becomes too long, and there is a possibility that the component (A) which blocks the polymerization site is present. The case of aggregation.

Therefore, it is preferable to set the number of repetitions m in the substituent represented by the formula (2) to an integer of 1 to 4, and it is particularly preferable to set it to an integer of 1 to 2.

Further, from the same viewpoint, it is generally preferable to set the carbon number n in the substituent represented by the general formula (2) to an integer of 1 to 4.

In addition, the position of the polymerizable carbon-carbon double bond as a polymerization site is too close to the biphenyl ring, and the biphenyl ring becomes a steric hindrance, and the polymerization rate of the component (A) is lowered. The carbon number n in the substituent represented by the formula (2) is preferably an integer of 2 to 4, and particularly preferably an integer of 2 to 3.

In addition, as a specific example of the biphenyl compound represented by the formula (1), a compound which can be represented by the following general formulae (3) to (4) is preferable.

(2) Weight average molecular weight

Moreover, it is preferable that the weight average molecular weight of the specific (meth) acrylate which is (A) component is the value in the range of 200-2500.

For this reason, it is presumed that the weight average molecular weight of the specific (meth) acrylate as the component (A) is set to a predetermined range, that is, The polymerization rate of the component (A) can be further accelerated, so that the copolymerizability of the component (A) and the component (B) can be more effectively reduced.

As a result, when the light is cured, the louver structure in which the plate member derived from the component (A) and the plate member derived from the component (B) are alternately extended can be formed more effectively.

In other words, when the weight average molecular weight of the component (A) is less than 200, the positions of the plurality of aromatic rings and the position of the polymerizable carbon-carbon double bond become too close, and the polymerization rate is lowered due to steric hindrance. The polymerization rate of the component (B) is close to that of the component (B). On the other hand, when the weight average molecular weight of the component (A) is more than 2,500, the difference in molecular weight from the component (B) is small, and the polymerization rate of the component (A) is lowered to approach the polymerization rate of the component (B). It is presumed that the copolymerization with the component (B) is apt to occur, and as a result, it may be difficult to form the louver structure efficiently.

Therefore, it is preferable to set the weight average molecular weight of the specific (meth) acrylate as the component (A) to a value in the range of 240 to 1,500, and it is particularly preferable to set the value in the range of 260 to 1,000.

Further, the weight average molecular weight of the component (A) can be determined from a calculated value obtained from the composition of the molecule and the atomic weight of the constituent atoms.

Further, the weight average molecular weight of the component (A) can also be measured by colloidal permeation chromatography (GPC).

Further, the composition for anisotropic light-diffusing film of the present invention is characterized in that, as a monomer component forming a plate-like region having a high refractive index in the louver structure, a component containing a plurality of aromatic rings as the component (A) is contained. The (meth) acrylate is preferably contained as the monomer component alone as the component (A).

The reason is that, by such a configuration, it is possible to effectively suppress the plate-like region derived from the component (A) in the louver structure, that is, the plate-like region having a high refractive index. The fluctuation of the refractive index makes it possible to more effectively form an anisotropic light-diffusing film having a given louver structure.

In other words, when the compatibility of the component (A) and the component (B) is low, for example, when the component (A) is a halogen compound, the component (A) and (B) may be used. The third component in which the components are compatible is used in combination with other components (A) (for example, a non-halogen compound).

However, in this case, the fluctuation of the refractive index in the plate-like region having a high refractive index derived from the component (A) may be easily lowered by the influence of the third component.

As a result, there is a case where the refractive index difference from the plate-like region having a low refractive index derived from the component (B) becomes uneven or tends to be excessively lowered.

Therefore, it is preferred to select a monomer component having a high refractive index which is compatible with the component (B) and use it as a separate component (A).

In addition, for example, the biphenyl compound represented by the formula (3) as the component (A) has a viscosity lower than that of the component (B), and therefore can be used as a single component (A).

(3) Refractive index

Moreover, it is preferable to set the refractive index of the specific (meth)acrylate which is (A) component into the range of 1.5-1.65.

The reason for this is that by setting the refractive index of the component (A) to a value within the range, it is possible to more easily adjust the plate-like region derived from the component (A) in the louver structure, and the source (B) The difference in refractive index of the plate-like region of the component makes it possible to more effectively obtain an anisotropic light-diffusing film having a given louver structure.

That is, when the refractive index of the component (A) is less than 1.5, the difference in refractive index from the component (B) is too small, and it may be difficult to obtain a desired incident angle dependency. On the other hand, if the refractive index of the component (A) is When the value exceeds 1.65, the difference in refractive index from the component (B) becomes large, but compatibility with the component (B) may become difficult.

Therefore, it is preferable to set the refractive index of the specific (meth) acrylate as the component (A) to a value in the range of 1.55 to 1.6, and it is particularly preferable to set the value in the range of 1.56 to 1.59.

Further, the refractive index of the component (A) described above means the refractive index of the component (A) before curing by light irradiation.

Further, the refractive index can be measured in accordance with, for example, JIS K0062.

(4) content

In addition, the content of the specific (meth) acrylate as the component (A) is set to 25 with respect to 100 parts by weight of the urethane (meth) acrylate as the component (B) to be described later. A value in the range of ~400 parts by weight.

The reason is that when the content of the component (A) is less than 25 parts by weight, the ratio of the component (A) to the component (B) is small, and the component of the louver has a component derived from the component (A). The width of the plate-like region becomes too small as compared with the width of the plate-like region derived from the component (B), so that it is difficult to obtain a louver structure having a good incident angle dependency. Further, 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) is more than 400 parts by weight, the ratio of the component (A) to the component (B) increases, and the plate-like structure derived from the component (A) in the louver structure The width of the region is excessively larger than the width of the plate-like region derived from the component (B), and conversely, it may be difficult to obtain a louver structure having a good incident angle dependency. Further, 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, it is preferable to set the content of the specific (meth) acrylate as the component (A) to 40 to 300 by weight with respect to 100 parts by weight of the urethane (meth) acrylate as the component (B). The value within the range of parts is particularly preferably set to a value in the range of 50 to 200 parts by weight.

2. (B) component: carbamate (meth) acrylate

(1) Category

The composition for anisotropic light-diffusing film of the present invention contains, as component (B), a urethane (meth) acrylate derived from a predetermined constituent component.

In other words, it includes the following components (a) to (c) as constituent components, and (a) component: (b) component: (c) component = 1 to 5 in terms of molar ratio: A urethane (meth) acrylate composed of a ratio of 1:1 to 5.

(a) a compound having 2 isocyanate groups via an aliphatic ring; (b) a polyolefin diol; (c) a hydroxyalkyl (meth) acrylate.

The reason for this is that, in the case of the specific urethane (meth) acrylate, a compound containing two isocyanate groups via the aliphatic ring as the component (a) (hereinafter referred to as alicyclic) Diisocyanate.) As a constituent component, it is easy to form a difference in the reaction rate of each isocyanate group.

In particular, as compared with hexamethylene diisocyanate, a compound containing two isocyanate groups in an aliphatic chain (hereinafter referred to as an aliphatic diisocyanate) can be easily used in each isocyanate group by the influence of stereo coordination or the like. There is a difference in the speed of reaction.

Therefore, for example, it is possible to suppress the component (a) from reacting only with the component (b), or the component (a) reacting only with the component (c), and it is possible to reliably react the component (a) with the component (b) and the component (c). Thereby, the generation of excess by-products can be prevented.

As a result, it is possible to effectively suppress the fluctuation of the refractive index in the plate-like region derived from the component (B) in the anisotropic light-diffusing film, that is, in the plate-like region having a low refractive index.

In addition, when the alicyclic diisocyanate as the component (a) is used as a constituent component, the urethane (meth) acrylate obtained as the component (B) and the specific component (A) can be obtained ( The compatibility of the methyl acrylate is reduced to a given range, thereby forming the louver structure more efficiently.

In particular, a urethane (meth) acrylate which is obtained as the component (B) and (A) can be obtained as compared with a diisocyanate having an aromatic ring like toluene diisocyanate (hereinafter referred to as an aromatic diisocyanate). The compatibility of the (meth) acrylate containing a plurality of aromatic rings of the component is lowered to a given range, thereby more effectively forming the louver structure.

In other words, since the aromatic diisocyanate has an aromatic ring in the skeleton, the obtained urethane (meth) acrylate as the component (B) and the aromatic ring (A) in the skeleton are obtained in the same manner. The compatibility of the components becomes too high, so that it is difficult to form the louver structure efficiently.

Further, in the case of the alicyclic diisocyanate, the refractive index of the obtained urethane (meth) acrylate as the component (B) can be made smaller than that of the aromatic diisocyanate.

That is, in general, since the aromatic ring is contained in the molecule, the refractive index of the compound tends to rise.

Therefore, it is possible to increase the difference between the refractive index of the obtained urethane (meth) acrylate as the component (B) and the refractive index of the specific (meth) acrylate as the component (A), which is more effective. The ground forms a louver structure with good incident angle dependence.

Further, even if the urethane (meth) acrylate containing an aliphatic diisocyanate or an aromatic diisocyanate as a constituent component is only within a range that does not impair the effects of the present invention, it is not limited to the present invention. (B) ingredients coexist.

Further, as the alicyclic diisocyanate containing two isocyanate groups as the component (a), for example, isophorone diisocyanate (IPDI), 2,4- and/or 2,6-methyl ring may be preferably used. Hexane diisocyanate, cyclohexylenemethane-4,4'-diisocyanate, cyclohexylene diisocyanate, methyl cyclohexylene diisocyanate, bis(2-isocyanateethyl)-4-cyclohexylene-1, 2-Dicarboxylate, 2,5- and/or 2,6-norbornane diisocyanate, dimer acid diisocyanate (DDI), and the like.

Among them, isophorone diisocyanate (IPDI) is preferred because of the large difference in reaction rates between the two isocyanate groups.

Further, among the components forming the urethane (meth) acrylate, the polyolefin diol which is the component (b) may be, for example, polyethylene glycol, polypropylene glycol, polytetramethylene glycol or polyhexane diol. Etc. Among them, it is particularly preferred to be polypropylene glycol.

The reason for this is that if it is a polypropylene glycol, since it has a low viscosity, it can operate without solvent.

Further, in the case of polypropylene glycol, when the component (B) is cured, a good flexible segment in the cured product is formed, and the workability or mountability of the anisotropic light-diffusing film can be effectively improved.

Further, the weight average molecular weight of the component (B) can be mainly adjusted by the weight average molecular weight of the component (b). Here, the weight average molecular weight of the component (b) is generally 2300 to 19,500, preferably 4,300 to 14,300, and particularly preferably 6,300 to 12,300.

Further, among the components forming the urethane (meth) acrylate, the hydroxyalkyl (meth) acrylate which is the component (c) may be, for example, 2-hydroxyethyl (meth) acrylate, ( 2-hydroxypropyl methacrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-(meth) acrylate Hydroxybutyl ester and the like.

Further, from the viewpoint of lowering the polymerization rate of the obtained urethane (meth) acrylate and more effectively forming a given louver structure, it is preferably a hydroxyalkyl methacrylate, particularly preferably a methyl group. 2-hydroxyethyl acrylate.

Further, the synthesis of the urethane (meth) acrylate by the components (a) to (c) can be carried out in accordance with a usual method.

It is preferable to set the mixing ratio of the components (a) to (c) at this time as (a) component by the molar ratio: (b) component: (c) component = 1 to 5: 1:1 to 5 ratio .

The reason is that the urethane (meth) acrylate can be efficiently synthesized by using the blending ratio, that is, the two hydroxyl groups of the component (b) and the component (a) One of the isocyanate groups is reacted and combined, and the other isocyanate group which is respectively possessed by the two (a) components is reacted with the hydroxyl group of the component (c) to be bonded.

Therefore, it is preferable to set the ratio of the components (a) to (c) to (a) component in the molar ratio: (b) component: (c) component = 1 to 3: 1:1 to 3 ratio It is especially suitable to set the ratio of 2:1:2.

(2) Weight average molecular weight

In addition, the weight average molecular weight of the urethane (meth) acrylate which is the component (B) is a value in the range of 3,000 to 20,000.

The reason for this is that by setting the weight average molecular weight of the urethane (meth) acrylate as the component (B) to a predetermined range, the polymerization rate of the component (B) is further lowered, and the polymerization rate is more effectively By preventing the copolymerization of the component (A) and the component (B), an anisotropic light-diffusing film having a given louver structure can be obtained more efficiently.

In other words, when the weight average molecular weight of the component (B) is less than 3,000, the polymerization rate of the component (B) is increased, and the polymerization rate of the component (A) is likely to cause copolymerization with the component (A). As a result, there is a case where it is difficult to form the louver structure efficiently. On the other hand, when the weight average molecular weight of the component (B) is more than 20,000, it is difficult to form a plate-like region derived from the component (A) and a plate-like region derived from the component (B). In the case of the louver structure, the component (A) is precipitated at the coating stage by excessively reducing the compatibility with the component (A).

Therefore, it is preferred to set the weight average molecular weight of the urethane (meth) acrylate as the component (B) to a value in the range of 5,000 to 15,000, and more preferably in the range of 7,000 to 13,000. .

Further, the weight average molecular weight of the component (B) can be measured by colloidal permeation chromatography (GPC).

In addition, the composition for anisotropic light-diffusing film of the present invention is characterized in that it contains a urethane as a component (B) as an oligomer component which forms a plate-like region having a low refractive index in a louver structure. The methyl acrylate preferably contains the component (B) as an oligomer component.

The reason for this is that, by such a configuration, it is possible to effectively suppress the fluctuation of the refractive index of the plate-like region derived from the component (B) in the louver structure, that is, the plate-like region having a low refractive index, thereby being more efficiently obtained. An anisotropic light diffusing film having a given louver structure.

That is, in the case where a plurality of (B) components are used, the refractive index of the plate-like region derived from the (B) component having a low refractive index fluctuates or becomes high, and there is a refraction derived from the component (A). The case where the refractive index difference of the plate-like region having a high rate becomes uneven or excessively lowered.

(3) Refractive index

Moreover, it is preferable that the refractive index of the urethane (meth) acrylate which is a component (B) is set to the range of 1.4-1.5.

The reason is that the refractive index of the component (B) is set to a value within the range, that is, it is easier to adjust the plate-like region derived from the component (A) and the plate derived from the component (B) in the louver structure. The difference in refractive index of the region makes it possible to more effectively obtain an anisotropic light-diffusing film having a given louver structure.

In other words, when the refractive index of the component (B) is less than 1.4, the difference in refractive index from the component (A) is large, but the compatibility with the component (A) is extremely deteriorated. Cannot form a blind structure. On the other hand, when the refractive index of the component (B) exceeds 1.5, the difference in refractive index from the component (A) becomes too small, and it may be difficult to obtain a desired incident angle dependency.

Therefore, the refractive index of the urethane (meth) acrylate which is the component (B) is preferably in the range of 1.45 to 1.49, and particularly preferably in the range of 1.46 to 1.48.

Further, the refractive index of the component (B) described above means the refractive index of the component (B) before curing by light irradiation.

Further, the refractive index can be measured in accordance with, for example, JIS K0062.

Further, it is preferable that the difference between the refractive index of the component (A) and the refractive index of the component (B) is 0.01 or more.

The reason for this is that by setting the difference in refractive index to a value within a given range, it is possible to obtain a better incident angle dependency in light transmission and diffusion, and a wider light diffusion incident angle region. An anisotropic light diffusing film.

That is, if the difference in refractive index is less than 0.01, the angle of the total reflection of the incident light in the louver structure is narrowed, and thus the opening angle of the diffused light may become too narrow. On the other hand, when the difference in refractive index is an excessive value, the compatibility between the component (A) and the component (B) is deteriorated, and the louver structure may not be formed.

Therefore, it is preferable to set the difference between the refractive index of the component (A) and the refractive index of the component (B) to a value in the range of 0.05 to 0.5, and it is particularly preferable to set the value in the range of 0.1 to 0.2.

Further, the refractive indices of the components (A) and (B) mentioned herein refer to the refractive indices of the components (A) and (B) before curing by light irradiation.

(4) content

In addition, the content of the urethane (meth) acrylate as the component (B) is preferably in the range of 20 to 80% by weight based on 100% by weight based on the total amount of the composition for anisotropic light-diffusing film. The value inside.

The reason 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) is small, and the component of the louver structure is derived from the component (B). The width of the plate-like region becomes too small as compared with the width of the plate-like region derived from the component (A), so that it is difficult to obtain a louver structure having a good incident angle dependency. Further, the length of the louver in the thickness direction of the anisotropic light-diffusing film may be insufficient. On the other hand, when the content of the component (B) is more than 80% by weight, the ratio of the component (B) to the component (A) increases, and the platelet derived from the component (B) in the louver structure The width of the region is compared with the width of the plate-like region derived from the component (A) It becomes too large, and conversely, it may be difficult to obtain a louver structure having a good incident angle dependency. Further, the length of the louver in the thickness direction of the anisotropic light-diffusing film may be insufficient.

Therefore, it is preferable that the content of the urethane (meth) acrylate as the component (B) is 30 to 70% by weight based on 100% by weight of the total amount of the composition for anisotropic light-diffusing film. The value in the range is particularly preferably set to a value in the range of 40 to 60% by weight.

3. Photopolymerization initiator

Further, in the composition for anisotropic light-diffusing film of the present invention, it is preferred to contain a photopolymerization initiator as the component (C), if necessary.

The reason for this is that when a composition for anisotropic light-diffusing film is irradiated with an active energy ray by containing a photopolymerization initiator, a given louver structure can be efficiently formed.

Here, the photopolymerization initiator refers to a compound which generates radical seeds by irradiation with an active energy ray such as ultraviolet rays.

The photopolymerization initiator may, for example, be benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2, 2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone, 4-(2-hydroxyethoxy)phenyl-2 -(hydroxy-2-propyl)one, benzophenone, p-phenylbenzophenone, 4,4-diethylaminobenzophenone, dichlorobenzophenone, 2-methylindole , 2-ethyl hydrazine, 2-tert-butyl fluorene, 2-amino hydrazine, 2-methyl 9-oxosulfur [ ][ ](thioxanthone), 2-ethyl 9-oxosulfur [ ][ ], 2-chloro 9-oxosulfur [ ][ ], 2,4-dimethyl 9-oxosulfur [ ][ ], 2,4-diethyl 9-oxosulfur [ ][ Benzene dimethyl ketal, acetophenone dimethyl ketal, p-dimethylamino benzoate, oligo[2-hydroxy-2-methyl-1-[4-(1-A Ethyl vinyl) phenyl] propane or the like may be used alone or in combination of two or more.

In addition, the content of the photopolymerization initiator is preferably 100% by weight based on 100% by weight of the total of the components (A) and (B), and is preferably in the range of 0.2 to 20% by weight. The value in the range of 0.5 to 15% by weight is particularly preferably in the range of 1 to 10% by weight.

4. Other additives

Further, other additives may be appropriately added within a range not impairing the effects of the present invention.

As the other additives, for example, an antioxidant, an ultraviolet absorber, an antistatic agent, a polymerization accelerator, a polymerization inhibitor, an infrared absorber, a plasticizer, a diluent solvent, a leveling agent, and the like can be given.

In addition, the content of the other additives is preferably set to a value in the range of 0.01 to 5% by weight based on 100% by weight of the total of the components (A) and (B), and is preferably set. The value in the range of 0.02 to 3% by weight is particularly preferably in the range of 0.05 to 2% by weight.

[Second Embodiment]

A second embodiment of the present invention is an anisotropic light-diffusing film which is obtained by irradiating a composition for anisotropic light-diffusing film with an active energy ray, wherein the composition for anisotropic light-diffusing film is contained as (A) a component comprising a (meth) acrylate having a plurality of aromatic rings and a urethane (meth) acrylate as the component (B), and a urethane (meth) acrylate as the component (B) From the following components (a) to (c) as constituent components, and in terms of molar ratio The component (a) component: (b) component: (c) component = 1 to 5: 1:1 to 5, and the content of the component (A) is set to 100 parts by weight of the component (B). It is a value in the range of 25 to 400 parts by weight.

(a) a compound having 2 isocyanate groups via an aliphatic ring; (b) a polyolefin diol; (c) a hydroxyalkyl (meth) acrylate.

Hereinafter, a second embodiment of the present invention will be specifically described with reference to FIG. 5 while focusing on aspects different from the first embodiment.

1. Manufacturing method

Next, a method for producing the anisotropic light-diffusing film of the present invention will be described. However, the anisotropic light-diffusing film of the present invention is of course not limited by the following production methods.

(1) Preparation step of composition for anisotropic light-diffusing film

The preparation step of the composition for anisotropic light-diffusing film is a step of preparing a composition for an anisotropic light-diffusing film containing the components (A) and (B).

More specifically, it is preferred to mix the component (A) and the component (B) at a high temperature of 40 to 80 ° C to prepare a uniform mixed solution.

In addition, at the same time, it is preferable to add the other additives such as the component (C) to the mixed liquid, and then stir to a uniform appearance to achieve the desired viscosity, and then add the dilution as needed. A solvent is used to obtain a solution of the composition for anisotropic light-diffusing film.

Further, the details of each component, the blending ratio, and the like are omitted as described in the first embodiment.

(2) Coating step

As shown in FIG. 5( a ), the coating step is a step of applying the prepared composition for anisotropic light-diffusing film to the engineering sheet 2 to form the coating layer 1 .

As for the engineering film, it can be used for both plastic film and paper.

In the case of the plastic film, a polyester film such as a polyethylene terephthalate film, a polyolefin film such as a polyethylene film or a polypropylene film, or a cellulose film such as a triethylene cellulose film, and Polyimine film or the like.

Further, as for the paper, for example, it may be cellophane, coated paper, laminated cardboard, or the like.

Further, in the engineering sheet, after the photocuring, the obtained anisotropic light-diffusing film is easily peeled off from the engineering sheet, and it is preferable to provide a peeling layer on the coated surface side of the composition for anisotropic light-diffusing film of the engineering sheet. .

The release layer can be formed using a conventionally used release agent such as a ruthenium-based release agent, a fluorine-based release agent, an alkyd-based release agent, or an olefin-based release agent.

Further, the thickness of the engineering sheet is generally set to a value in the range of 25 to 200 μm.

Further, as a method of applying the composition for anisotropic light-diffusing film on an engineering sheet, for example, a blade coating method, a roll coating method, a bar coating method, a knife coating method, an optical coating method, and gravure coating can be used. Conventional methods such as the law are carried out.

Further, in this case, it is preferable to set the thickness of the coating layer to a value in the range of 100 to 700 μm.

(3) Light curing step

The photocuring step is a step of photocuring the coating layer of the composition for anisotropic light-diffusing film and forming the coating layer into an anisotropic light-diffusing film.

That is, as shown in FIG. 5(b), the coating layer 1 formed on the engineered sheet 2 is irradiated with the active energy ray 50 composed only of the direct light whose irradiation angle has been controlled.

More specifically, for example, as shown in FIG. 6(a), the ultraviolet irradiation device 20 having the cold mirror 22 for collecting light is provided in the linear ultraviolet lamp 25 (if it is a commercially available product, it may be Eyegraphics). In the ECS-4011GX or the like, the infrared cut filter 21 and the light shielding plate 23 are disposed, and the active energy ray 50 composed only of the direct light having the controlled irradiation angle is taken out to the coating layer formed on the engineering sheet 2. 1 irradiation.

Further, the linear ultraviolet lamp is generally set to a value in the range of -80 to 80° based on the direction orthogonal to the longitudinal direction of the engineered sheet 2 having the coating layer 1 (0°). It is preferably set to a value in the range of -50 to 50°, and is preferably set to a value in the range of -30 to 30°.

At this time, as for the irradiation angle of the irradiation light, as shown in FIG. 6(b), it is generally preferable to set the irradiation angle θ3 when the angle of the normal to the surface of the coating layer 1 is 0° to - A value in the range of 80 to 80°.

The reason is that when the irradiation angle θ3 is a value outside the range of -80 to 80°, the influence of reflection or the like on the surface of the coating layer 1 becomes large, and it is difficult to form a sufficient louver structure. Happening.

Further, the irradiation angle θ3 is preferably a width (irradiation angle width) θ3' of 1 to 80°.

The reason is that when the irradiation angle width θ3' is less than 1°, the interval between the louver structures is too narrow, and it may be difficult to obtain an anisotropic light-diffusing film. On the other hand, when the irradiation angle width θ3' is a value exceeding 80°, the irradiation light is excessively dispersed, and the louver structure may be difficult to form.

Therefore, it is preferable to set the irradiation angle width θ3' of the irradiation angle θ3 to a value in the range of 2 to 45°, and it is particularly preferable to set the value in the range of 5 to 20°.

Further, by using the linear light source, it is possible to illuminate the substantially parallel light when viewed from the axial direction of the linear light source, and the non-parallel illumination light when viewed from a direction perpendicular to the axial direction of the linear light source.

Further, as for the irradiation light, ultraviolet rays, electron beams, or the like may be used, but it is preferred to use ultraviolet rays.

The reason for this is that in the case of an electron beam, since the polymerization rate is very fast, the components (A) and (B) cannot be sufficiently phase-separated during the polymerization, and it may be difficult to form a louver structure. On the other hand, when compared with visible light or the like, the ultraviolet curable resin which is cured by irradiation with ultraviolet rays has a rich change in the photopolymerization initiator which can be used, so that the selection of the component (A) and the component (B) can be broadened. range.

In addition, the irradiation condition of the ultraviolet ray is preferably such that the peak illuminance at the time of irradiation is in a range of 0.1 to 50 mW/cm ² and the integrated light amount for sufficiently curing the coating layer is obtained.

Further, it is preferred to irradiate the ultraviolet rays in multiple stages so as to achieve an integrated amount of light for sufficiently curing the coating layer.

Further, it is preferable that the coating layer formed on the engineering sheet is moved at a speed of 0.1 to 10 m/min and passed through the ultraviolet ray irradiation portion of the ultraviolet ray irradiation device.

The reason is that if the speed is less than 0.1 m/min, there is a case where the mass productivity is excessively lowered. On the other hand, if the speed is more than 10 m/min, the curing of the coating layer is faster, in other words, the formation of the louver structure is faster, and the incident angle of the ultraviolet ray relative to the coating layer is larger along the film thickness direction. The amplitude changes, so that the formation of the louver structure is insufficient.

Therefore, it is preferable to move the coating layer formed on the substrate at a speed in the range of 0.2 to 5 m/min, and pass through the ultraviolet irradiation portion of the ultraviolet irradiation device, particularly preferably in the range of 0.5 to 3 m/min. The speed passes through.

Further, as shown in FIG. 5(c), the anisotropic light-diffusing film 10 after the photo-curing step is finally brought into a usable state by peeling off the engineered sheet 2.

2. Film thickness

Further, it is preferable to set the film thickness of the anisotropic light-diffusing film to a value in the range of 100 to 500 μm.

The reason for this is that the film thickness of the anisotropic light-diffusing film is set to a value within the range, and it is applied to a reflective liquid crystal display device in a single layer state without laminating the anisotropic light-diffusing film. In the middle, the external light can be effectively utilized as a light source, and the problem that the sharpness of the displayed image is lowered or the rainbow color is generated can be prevented.

In other words, if the film thickness is less than 100 μm, the length of the louver structure formed in the film thickness direction in the film becomes too short, and the incident light traveling straight in the louver structure increases, which makes it difficult to obtain Sufficient angle of incidence dependence. On the other hand, when the film thickness exceeds 500 μm, the irradiation light is irradiated for a long period of time, so that the mass productivity is excessively lowered, or the irradiation light is diffused by the louver structure formed at the beginning, and it is difficult to form the required light. The case of the shutter structure.

Therefore, it is preferable to set the film thickness of the anisotropic light-diffusing film to a value in the range of 130 to 300 μm, and it is particularly preferable to set the value in the range of 150 to 250 μm.

3. Louver structure

Further, as shown in FIGS. 7(a) to 7(c), the anisotropic light-diffusing film 10 of the present invention includes a plate-like region 12 derived from the component (A) and a plate-like region derived from the component (B). 14 louver structures which are alternately extended, however, it is preferable to set the respective widths (S1, S2) of the plate-like region 12 derived from the component (A) and the plate-like region 14 derived from the component (B) to 0.1 to 15 μm. The value in the range.

The reason is that if the width is less than 0.1 μm, the light diffusibility may be hard to be displayed regardless of the incident angle of the incident light.

On the other hand, when the width is a value exceeding 15 μm, on the contrary, regardless of the incident angle of the incident light, it is difficult to exhibit light diffusibility.

Therefore, it is preferable to set the respective widths (S1, S2) of the plate-like region 12 derived from the component (A) and the plate-like region 14 derived from the component (B) to a value in the range of 0.5 to 10 μm. It is preferably set to a value in the range of 1 to 5 μm.

Further, it is preferable to set the initial inclination angle θ4 of the louver structure to a value in the range of 0 to 80°.

The reason is that when the initial inclination angle θ4 is a value exceeding 80°, it may be difficult to show the incident angle dependency.

Therefore, it is preferable to set the initial inclination angle θ4 of the louver structure to a value in the range of 0 to 50°.

In addition, the initial inclination angle θ4 is an angle of a narrow side of the angle between the normal line of the film surface on the side where the incident light is incident and the louver as shown in FIG. 7 .

More specifically, the initial inclination angle θ4 is a plate shape when the angle is normalized with respect to the normal line of the film surface measured when the film is cut on the surface perpendicular to the louver structure extending in the film surface direction. The angle of inclination of the area (°).

Further, as shown in FIG. 7, the inclination angle when the plate-like region is inclined to the right side is used as a reference, and the inclination angle when the plate-like region is inclined to the left side is represented by a negative value.

Further, the anisotropic light-diffusing film 10 of the present embodiment may form a louver structure (length L1 in the film thickness direction) in the entire film thickness direction as shown in FIG. 7(a), or may be as shown in FIG. 7(b). At least one of the upper end portion and the lower end portion of the film 10 has a portion in which the louver is not formed (length L2 in the film thickness direction).

Further, the film thickness direction length L1 of the louver structure is determined by the film thickness of the anisotropic light-diffusing film 10, but in general, it is preferably in the range of 50 to 500 μm.

The reason is that if the length is less than 50 μm, the incident light that travels straight in the louver structure increases, and it may be difficult to obtain a sufficient incident angle dependency. On the other hand, when the length is a value exceeding 500 μm, there is a case where light is reflected or absorbed during the passage through the louver structure.

Therefore, it is preferable to set the length L1 in the film thickness direction of the louver structure to a value in the range of 130 to 300 μm, and it is particularly preferable to set the value in the range of 150 to 250 μm.

Further, the film thickness direction length L2 of the lower end portion of the louver structure is not determined by the film thickness of the anisotropic light diffusion film 10, but in general, it is preferably in the range of 0 to 200 μm, preferably 0. A value in the range of ~100 μm is particularly preferably in the range of 0 to 50 μm.

Further, as shown in Fig. 7(c), it is preferable that the louver structure is curved.

The reason for this is because the louver structure is curved, and the incident light traveling straight in the louver structure can be reduced, and the uniformity of light diffusion can be improved.

Further, such a curved louver structure can be obtained by irradiating light while changing the irradiation angle of the irradiation light when photocuring the composition for anisotropic light-diffusing film, but it is also considerably dependent on (A) The composition and the type of component (B).

Further, it is 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 1.5 to 1.7.

The reason is that if the refractive index derived from the plate-like region of the component (A) is less than 1.5, the difference in refractive index from the plate-like region derived from the component (B) is too small. There are cases where the required anisotropy cannot be obtained. The other side When the refractive index of the plate-like region derived from the component (A) exceeds 1.7, the compatibility with the component (B) may become too low.

Therefore, it is 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 it is particularly preferable to set the value in the range of 1.55 to 1.6.

Further, the refractive index can be measured in accordance with, for example, JIS K0062.

Further, it is preferable to set the refractive index of the plate-like region derived from the component (B) in the louver structure to a value in the range of 1.4 to 1.5.

The reason for this is that if the refractive index derived from the plate-like region of the component (B) is less than 1.4, the rigidity of the obtained anisotropic light-diffusing film may be lowered. On the other hand, when the refractive index of the plate-like region derived from the component (B) is more than 1.5, the difference in refractive index from the plate-like region derived from the component (A) is too small, which may be difficult. Get the desired anisotropy.

Therefore, it is preferable to set the refractive index of the plate-like region derived from the component (B) in the louver structure to a value in the range of 1.42 to 1.48, and it is particularly preferable to set the value in the range of 1.44 to 1.46.

Further, the refractive index can be measured in accordance with, for example, JIS K0062.

Further, in the anisotropic light-diffusing film of the present embodiment, it is preferable that 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) The difference is set to a value of 0.01 or more.

The reason is that if the difference in refractive index is less than 0.01, the angle of the total reflection of the incident light in the louver structure is narrowed, and thus the opening angle of the diffused light may become too narrow.

Therefore, it is preferable to set the difference between the refractive index of the plate-like region derived from the component (A) and the refractive index of the plate-like region derived from the component (B) in the louver structure to a value of 0.03 or more.

Further, although the difference in refractive index is as large as possible, it is considered that the upper limit is about 0.1.

4. Use

Further, as shown in FIG. 8, it is preferable to use the anisotropic light-diffusing film of the present invention in the reflective liquid crystal display device 100.

The reason for this is that the anisotropic light-diffusing film of the present invention can be efficiently diffused by introducing the external light into the liquid crystal display device and allowing the light to be used as a light source.

Therefore, the anisotropic light-diffusing film of the present invention is preferably disposed above or below the liquid crystal cell 110 including the glass plate (104, 108), the liquid crystal 106, the specular reflection plate 107, and the like as a light diffusing plate of the reflective liquid crystal display device 100. 103 used.

[Examples]

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

[Example 1]

1. Synthesis of (B) components

In the container, the polypropylene glycol (PPG) 1 mol of the weight average molecular weight of 9200 as the component (b) is contained, and the isophorone diisocyanate (IPDI) 2 mol as the component (a) is contained, and as (c) After the component of 2-hydroxyethyl methacrylate (HEMA) 2 moles, it was polymerized according to a conventional method to obtain a polyether urethane methacrylate having a weight average molecular weight of 9,900.

Further, the weight average molecular weight of PPG and polyether urethane methacrylate is a polystyrene equivalent value measured by colloidal permeation chromatography (GPC) according to the following conditions.

GPC measuring device: HTC-8020 manufactured by Tosoh Tosoh Co., Ltd.

GPC column: Tosoh (share) system (the following is recorded in order)

TSK guard column HXL-H

TSK gel GMHXL (×2)

TSK gel G2000HXL

. Determination of solvent: tetrahydrofuran

. Measuring temperature: 40 ° C

2. Preparation of composition for anisotropic light-diffusing film

Then, the weight average molecular weight represented by the following formula (3) as the component (A) is added to 100 parts by weight of the polyether urethane methacrylate having a weight average molecular weight of 9900 as the component (B). 100 parts by weight of o-phenylphenoxyethyl acrylate (NK Ester A-LEN-10, manufactured by Shin-Nakamura Chemical Co., Ltd.), and 10 parts by weight of 2-hydroxy-2-methylpropiophenone as component (C) After that, the mixture was heated and mixed under the conditions of 80 ° C to obtain a composition for an anisotropic light-diffusing film.

Here, the refractive indices of the (A) component and the (B) component are measured by an Abbe refractometer (product name: Abbe refractometer DR-M2, light source: Na light source, wavelength: 589 nm). It was measured in accordance with JIS K0062.

Further, the compound represented by the formula (3) is sometimes referred to as biphenyl-1 in the following.

[Chemical Formula 6]

3. Coating of composition for anisotropic light-diffusing film

Then, the obtained composition for anisotropic light-diffusing film was applied onto a transparent polyethylene terephthalate film (hereinafter referred to as PET) as a film of a work piece using a dispenser to obtain a film thickness of 250 μm. Coating layer.

4. Light curing of the coating layer

Then, an ultraviolet irradiation device (ECS-4011GX manufactured by Eyegraphics Co., Ltd.) equipped with a cold mirror for collecting light is provided in the high-pressure mercury lamp having a line shape as shown in FIG.

Then, a light shielding plate is provided on the infrared cut filter frame, and the ultraviolet ray irradiated onto the surface of the coating layer is set to be a laminate including the coating layer and the PET when viewed from the longitudinal direction of the linear ultraviolet lamp. When the normal direction is set to 0°, the direct ultraviolet light irradiation angle (θ3 in FIG. 6(b)) from the lamp is 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 9 mW/cm ² .

In addition, the reflected light at the visor or the like becomes stray light inside the illuminator, and in order to prevent the light curing of the coating layer from being affected, a light shielding plate is also provided in the vicinity of the conveyor belt, and only the ultraviolet ray directly emitted from the lamp is applied. Set the layer illumination mode.

Then, the coating layer was irradiated with ultraviolet rays while moving at a speed of 0.2 m/min in the right direction of FIG. 6 by a conveyor belt to obtain an anisotropic light-diffusing film having a film thickness of 250 μm.

Further, the film thickness of the anisotropic light-diffusing film was measured using a constant-voltage thickness measuring device (TECLOCK PG-02J, manufactured by Takara Seisakusho Co., Ltd.).

In addition, the cross section of the anisotropic light-diffusing film was observed by an optical digital microscope (manufactured by Kyence Co., Ltd.), and as a result, the inclination angle (initial inclination angle) of the louver structure in which the irradiation light was first irradiated to the film surface side was 6.5. °, the length in the film thickness direction of the louver structure (L1 in Fig. 7(b)) was 200 μm.

5. Evaluation

(1) Evaluation of incident angle dependence based on measurement

Using a variable angle colorimeter (VC-2 manufactured by Suga Suga Tester Co., Ltd.), light was incident on the film from below the obtained anisotropic light-diffusing film (C light source, viewing angle: 2°).

Then, the luminance (%) of the diffused light diffused by the anisotropic light-diffusing film was measured at an angle of 5°.

Then, the angular range between the measurement points at the both ends of the difference between the adjacent measurement points is less than 10%, and the angular width of the angle region is defined as the aperture angle (°) of the diffused light.

Further, the diffusion region when the incident angle of the incident light is 0°, the average value of the luminance of the diffusion region, and the absolute value of the difference between the average value and the maximum value and the minimum value of the luminance of the diffusion region are respectively shown in Table 1. in.

Further, the incident angle of the incident light is continuously changed, and the opening angle of the diffused light at each incident angle is measured, and the incident angle of the diffused light is 10° or more. The range of the angle is set to the light diffusion incident angle area. The results obtained are shown in Table 1.

Further, the larger the value of the opening angle of the diffused light, the more the incident light incident at the incident angle at this time is effectively diffused by the anisotropic light-diffusing film.

On the other hand, the smaller the opening angle of the diffused light, the more the light incident at the incident angle at this time passes through the anisotropic light-diffusing film as it is, and is not pre-diffused.

Further, with respect to the first, third, and fourth embodiments, the characteristic angles of the incident angle (°) with respect to the anisotropic light-diffusing film and the opening angle (°) of the diffused light in the vertical axis are respectively represented in the horizontal axis. In Figure 9.

Further, for example, as in the case of the first embodiment, in the case where there is no measurement point when the opening angle of the diffused light is 10° on the characteristic curve, the opening angle according to the characteristic curve (outer line) and the diffused light=10 The value of the incident angle (°) at the intersection of the straight lines of °, and the value of the light diffusing incident angle region.

(2) Evaluation based on visual anisotropy

(2)-1 light diffusivity

The panel members were evaluated from the front side (diffusion direction) of the anisotropic light-diffusing film by visually observing the opposite side of the film, and evaluated according to the following criteria as evaluation of light diffusibility based on visual observation. The results obtained are shown in Table 1.

A: Five of the five people were judged to have sufficient opacity.

B: 3 to 4 out of 5 people judged to have sufficient opacity.

C: 3 to 5 out of 5 people judged that although opacity was poor, they still had opacity.

D: 3 to 4 out of 5 people judged to be opaque.

E: 5 out of 5 people judged to have no opacity.

(2)-2 light transmission

The panel members were evaluated by visual observation of the light transmittance of the anisotropic light-diffusing film in the direction of the 45° direction (transmission direction) by observing the opposite side of the film. Evaluation. The results obtained are shown in Table 1.

◎: 5 out of 5 people were judged to be completely transparent and free from coloration.

○: 3 to 4 of 5 people were judged to be completely transparent and not colored.

△: 3 to 4 of 5 people were judged to be white or yellow.

×: Five of the five persons were judged to be white turbid or yellow.

[Embodiment 2]

In Example 2, the weight average molecular weight of the polyether urethane methacrylate as the component (B) was changed by changing the component (b) to a PPG having a weight average molecular weight smaller than that in the case of Example 1. A composition for an anisotropic light-diffusing film was prepared in the same manner as in Example 1 except for 6100, and an anisotropic light-diffusing film was produced and evaluated. The results obtained 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 by changing the component (b) to a PPG having a weight average molecular weight larger than that in the case of Example 1. A composition for an anisotropic light-diffusing film was prepared in the same manner as in Example 1 except for the case of 14500, and an anisotropic light-diffusing film was produced and evaluated. The results obtained are shown in Table 1.

[Example 4]

In the fourth embodiment, the amount of the component (A) added is 60 parts by weight, and the amount of the component (C) is 20 parts by weight, based on 100 parts by weight of the component (B). In the same manner as in Example 1, a composition for an anisotropic light-diffusing film was prepared in the same manner as in Example 1, and an anisotropic light-diffusing film was produced and evaluated. The results obtained are shown in Table 1.

[Example 5]

In Example 5, a composition for anisotropic light-diffusing film was produced in the same manner as in Example 1 except that the amount of the component (A) was changed to 150 parts by weight based on 100 parts by weight of the component (B). An anisotropic light diffusing film was evaluated. The results obtained are shown in Table 1.

[Embodiment 6]

In the sixth embodiment, in the case of synthesizing the component (B), 2-hydroxyethyl acrylate (HEA) is used as the component (c), and the amount of the component (C) is set to 100 parts by weight of the component (B). A composition for an anisotropic light-diffusing film was prepared in the same manner as in Example 1 except for 20 parts by weight, and an anisotropic light-diffusing film was produced and evaluated. The results obtained are shown in Table 1.

[Embodiment 7]

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

[Embodiment 8]

In Example 8, the amount of the component (C) added was changed to 4 parts by weight, and the film thickness of the anisotropic light-diffusing film was changed to 500 μm, in addition to 100 parts by weight of the component (B). An anisotropic light-diffusing film was produced and evaluated by preparing a composition for an anisotropic light-diffusing film by the same method. The results obtained are shown in Table 1.

[Embodiment 9]

In Example 9, the amount of the component (C) added was changed to 2 parts by weight, and the film thickness of the anisotropic light-diffusing film was changed to 500 μm, in addition to 100 parts by weight of the component (B). An anisotropic light-diffusing film was produced and evaluated by preparing a composition for an anisotropic light-diffusing film by the same method. The results obtained are shown in Table 1.

[Embodiment 10]

In Example 10, except that o-phenylphenoxyethoxyethyl acrylate having a weight average molecular weight of 312 represented by the following formula (4) was used as the component (A), the same procedure as in Example 1 was carried out. An anisotropic light-diffusing film was produced and evaluated for the composition for anisotropic light-diffusing film. The results obtained are shown in Table 1.

Further, the compound represented by the formula (4) is sometimes referred to as biphenyl-2 in the following.

[Example 11]

In the eleventh embodiment, a composition for anisotropic light-diffusing film was prepared in the same manner as in Example 1 except that the component (A) was a mixture of 50:50 (by weight) of biphenyl 1 and biphenyl 2 . An anisotropic light diffusion film was fabricated and evaluated. The results obtained are shown in Table 1.

[Comparative Example 1]

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

[Comparative Example 2]

In Comparative Example 2, in addition to the polyether urethane methacrylate as the component (B), 2-hydroxyethyl acrylate (HEA) was used as the component (c), and the polyether urethane was used. The composition of the anisotropic light-diffusing film was produced in the same manner as in Example 1 except that the weight average molecular weight of the methacrylate was changed to 740, and the film thickness of the anisotropic light-diffusing film was changed to 500 μm. Anisotropic light diffuses the film. The results obtained are shown in Table 1.

As described in detail above, according to the present invention, a (meth) acrylate having a plurality of aromatic rings is bonded to a urethane having a given weight average molecular weight and composed of a given constituent. The methyl acrylate is photocured in a given ratio, that is, an anisotropic light-diffusing film having a good incident angle dependency can be obtained.

More specifically, an anisotropic light-diffusing film having a good incident angle dependency in light transmission and diffusion and having a wide light diffusion incident angle region can be obtained.

Therefore, the composition for anisotropic light-diffusing film of the present invention can be applied to a light-control film of a reflective liquid crystal display device, and can also be applied to a viewing angle control film, a viewing angle expansion film, and a projection screen. It is expected to make a significant contribution to the high quality of these.

The above-mentioned embodiments are merely examples for convenience of description, and the scope of the claims is intended to be limited to the above embodiments.

10‧‧‧ Anisotropic light diffusing film

12‧‧‧A plate-like region derived from the higher refractive index of component (A)

13’‧‧‧ interface

13‧‧‧ Louver structure

14‧‧‧A plate-like region derived from the lower refractive index of component (B)

52,54,56‧‧‧ incident light (active energy ray)

52’, 54’, 56’‧‧‧ diffused light

Claims (10)

A composition for an anisotropic light-diffusing film comprising a (meth) acrylate containing a plurality of aromatic rings as the component (A), and a weight average molecular weight of the component (B) in a range of 7,000 to 13,000 a urethane (meth) acrylate having a photopolymerization initiator as a component (C); wherein the urethane (meth) acrylate of the component (B) is derived from The following components (a) to (c) as constituent components, and a compound having a molar ratio (a) component: (b) component: (c) component = 1 to 5: 1:1 to 5 (a) a compound containing 2 isocyanate groups on an aliphatic ring; (b) a polyolefin diol; (c) a hydroxyalkyl (meth) acrylate; wherein, 100 parts by weight relative to the component (B) The content of the component (A) is a value in the range of 25 to 400 parts by weight, and the component (C) is 100% by weight based on the total amount of the component (A) and the component (B). The content is set to a value in the range of 0.2 to 20% by weight. The composition for anisotropic light-diffusing film according to the first aspect of the invention, wherein the component (A) is contained alone as a monomer component, and the component (B) is contained alone as an oligomer component. The composition for anisotropic light-diffusing film according to the first aspect of the invention, wherein the component (c) of the component (B) is a hydroxyalkyl methacrylate. The composition for anisotropic light-diffusing film according to the first aspect of the invention, wherein the refractive index of the component (B) is a value within a range of from 1.4 to 1.5. The composition for anisotropic light-diffusing film according to the first aspect of the invention, wherein the component (A) is a plurality of aromatic rings containing a biphenyl ring. The composition for anisotropic light-diffusing film according to the first aspect of the invention, wherein the weight average molecular weight of the component (A) is in a range of from 200 to 2,500. The composition for anisotropic light-diffusing film according to the above aspect, wherein the refractive index of the component (A) is a value in the range of 1.5 to 1.65. The composition for anisotropic light-diffusing film according to the first aspect of the invention, wherein the component (b) of the component (B) has a weight average molecular weight of less than 4,300. An anisotropic light-diffusing film obtained by irradiating an energy beam with a composition for an anisotropic light-diffusing film, wherein the composition for anisotropic light-diffusing film contains: (A) component-containing a plurality of aromatic ring (meth) acrylate; and one (B) component weight average molecule A urethane (meth) acrylate having a value in the range of 7,000 to 13,000, wherein a photopolymerization initiator is simultaneously contained as the component (C); wherein the carbamate of the component (B) ( The methyl acrylate is derived from the following components (a) to (c) as constituent components, and is a component (a) in terms of a molar ratio: (b) component: (c) component = 1 to 5:1 a compound consisting of a ratio of 1 to 5; (a) a compound having 2 isocyanate groups on an aliphatic ring; (b) a polyolefin diol; (c) a hydroxyalkyl (meth) acrylate; 100 parts by weight of the component (B), the content of the component (A) is a value within a range of 25 to 400 parts by weight, and 100 parts by weight with respect to the total amount of the component (A) and the component (B). %, the content of the component (C) is set to a value in the range of 0.2 to 20% by weight. The anisotropic light-diffusing film according to claim 9, wherein the film thickness is a value within a range of 100 to 500 μm.